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1.  Stenting for Peripheral Artery Disease of the Lower Extremities 
Executive Summary
In January 2010, the Medical Advisory Secretariat received an application from University Health Network to provide an evidentiary platform on stenting as a treatment management for peripheral artery disease. The purpose of this health technology assessment is to examine the effectiveness of primary stenting as a treatment management for peripheral artery disease of the lower extremities.
Clinical Need: Condition and Target Population
Peripheral artery disease (PAD) is a progressive disease occurring as a result of plaque accumulation (atherosclerosis) in the arterial system that carries blood to the extremities (arms and legs) as well as vital organs. The vessels that are most affected by PAD are the arteries of the lower extremities, the aorta, the visceral arterial branches, the carotid arteries and the arteries of the upper limbs. In the lower extremities, PAD affects three major arterial segments i) aortic-iliac, ii) femoro-popliteal (FP) and iii) infra-popliteal (primarily tibial) arteries. The disease is commonly classified clinically as asymptomatic claudication, rest pain and critical ischemia.
Although the prevalence of PAD in Canada is not known, it is estimated that 800,000 Canadians have PAD. The 2007 Trans Atlantic Intersociety Consensus (TASC) II Working Group for the Management of Peripheral Disease estimated that the prevalence of PAD in Europe and North America to be 27 million, of whom 88,000 are hospitalizations involving lower extremities. A higher prevalence of PAD among elderly individuals has been reported to range from 12% to 29%. The National Health and Nutrition Examination Survey (NHANES) estimated that the prevalence of PAD is 14.5% among individuals 70 years of age and over.
Modifiable and non-modifiable risk factors associated with PAD include advanced age, male gender, family history, smoking, diabetes, hypertension and hyperlipidemia. PAD is a strong predictor of myocardial infarction (MI), stroke and cardiovascular death. Annually, approximately 10% of ischemic cardiovascular and cerebrovascular events can be attributed to the progression of PAD. Compared with patients without PAD, the 10-year risk of all-cause mortality is 3-fold higher in patients with PAD with 4-5 times greater risk of dying from cardiovascular event. The risk of coronary heart disease is 6 times greater and increases 15-fold in patients with advanced or severe PAD. Among subjects with diabetes, the risk of PAD is often severe and associated with extensive arterial calcification. In these patients the risk of PAD increases two to four fold. The results of the Canadian public survey of knowledge of PAD demonstrated that Canadians are unaware of the morbidity and mortality associated with PAD. Despite its prevalence and cardiovascular risk implications, only 25% of PAD patients are undergoing treatment.
The diagnosis of PAD is difficult as most patients remain asymptomatic for many years. Symptoms do not present until there is at least 50% narrowing of an artery. In the general population, only 10% of persons with PAD have classic symptoms of claudication, 40% do not complain of leg pain, while the remaining 50% have a variety of leg symptoms different from classic claudication. The severity of symptoms depends on the degree of stenosis. The need to intervene is more urgent in patients with limb threatening ischemia as manifested by night pain, rest pain, ischemic ulcers or gangrene. Without successful revascularization those with critical ischemia have a limb loss (amputation) rate of 80-90% in one year.
Diagnosis of PAD is generally non-invasive and can be performed in the physician offices or on an outpatient basis in a hospital. Most common diagnostic procedure include: 1) Ankle Brachial Index (ABI), a ratio of the blood pressure readings between the highest ankle pressure and the highest brachial (arm) pressure; and 2) Doppler ultrasonography, a diagnostic imaging procedure that uses a combination of ultrasound and wave form recordings to evaluate arterial flow in blood vessels. The value of the ABI can provide an assessment of the severity of the disease. Other non invasive imaging techniques include: Computed Tomography (CT) and Magnetic Resonance Angiography (MRA). Definitive diagnosis of PAD can be made by an invasive catheter based angiography procedure which shows the roadmap of the arteries, depicting the exact location and length of the stenosis / occlusion. Angiography is the standard method against which all other imaging procedures are compared for accuracy.
More than 70% of the patients diagnosed with PAD remain stable or improve with conservative management of pharmacologic agents and life style modifications. Significant PAD symptoms are well known to negatively influence an individual quality of life. For those who do not improve, revascularization methods either invasive or non-invasive can be used to restore peripheral circulation.
Technology Under Review
A Stent is a wire mesh “scaffold” that is permanently implanted in the artery to keep the artery open and can be combined with angioplasty to treat PAD. There are two types of stents: i) balloon-expandable and ii) self expandable stents and are available in varying length. The former uses an angioplasty balloon to expand and set the stent within the arterial segment. Recently, drug-eluting stents have been developed and these types of stents release small amounts of medication intended to reduce neointimal hyperplasia, which can cause re-stenosis at the stent site. Endovascular stenting avoids the problem of early elastic recoil, residual stenosis and flow limiting dissection after balloon angioplasty.
Research Questions
In individuals with PAD of the lower extremities (superficial femoral artery, infra-popliteal, crural and iliac artery stenosis or occlusion), is primary stenting more effective than percutaneous transluminal angioplasty (PTA) in improving patency?
In individuals with PAD of the lower extremities (superficial femoral artery, infra-popliteal, crural and iliac artery stenosis or occlusion), does primary stenting provide immediate success compared to PTA?
In individuals with PAD of the lower extremities (superficial femoral artery, infra-popliteal, crural and iliac artery stenosis or occlusion), is primary stenting associated with less complications compared to PTA?
In individuals with PAD of the lower extremities (superficial femoral artery, infra-popliteal, crural and iliac artery stenosis or occlusion), does primary stenting compared to PTA reduce the rate of re-intervention?
In individuals with PAD of the lower extremities (superficial femoral artery, infra-popliteal, crural and iliac artery stenosis or occlusion) is primary stenting more effective than PTA in improving clinical and hemodynamic success?
Are drug eluting stents more effective than bare stents in improving patency, reducing rates of re-interventions or complications?
Research Methods
Literature Search
A literature search was performed on February 2, 2010 using OVID MEDLINE, MEDLINE In-Process and Other Non-Indexed Citations, OVID EMBASE, the Cochrane Library, and the International Agency for Health Technology Assessment (INAHTA). Abstracts were reviewed by a single reviewer and, for those studies meeting the eligibility criteria, full-text articles were obtained. Reference lists were also examined for any additional relevant studies not identified through the search. The quality of evidence was assessed as high, moderate, low or very low according to GRADE methodology.
Inclusion Criteria
English language full-reports from 1950 to January Week 3, 2010
Comparative randomized controlled trials (RCTs), systematic reviews and meta-analyses of RCTs
Proven diagnosis of PAD of the lower extremities in all patients.
Adult patients at least 18 years of age.
Stent as at least one treatment arm.
Patency, re-stenosis, re-intervention, technical success, hemodynamic (ABI) and clinical improvement and complications as at least an outcome.
Exclusion Criteria
Non-randomized studies
Observational studies (cohort or retrospective studies) and case report
Feasibility studies
Studies that have evaluated stent but not as a primary intervention
Outcomes of Interest
The primary outcome measure was patency. Secondary measures included technical success, re-intervention, complications, hemodynamic (ankle brachial pressure index, treadmill walking distance) and clinical success or improvement according to Rutherford scale. It was anticipated, a priori, that there would be substantial differences among trials regarding the method of examination and definitions of patency or re-stenosis. Where studies reported only re-stenosis rates, patency rates were calculated as 1 minus re-stenosis rates.
Statistical Analysis
Odds ratios (for binary outcomes) or mean difference (for continuous outcomes) with 95% confidence intervals (CI) were calculated for each endpoint. An intention to treat principle (ITT) was used, with the total number of patients randomized to each study arm as the denominator for each proportion. Sensitivity analysis was performed using per protocol approach. A pooled odds ratio (POR) or mean difference for each endpoint was then calculated for all trials reporting that endpoint using a fixed effects model. PORs were calculated for comparisons of primary stenting versus PTA or other alternative procedures. Level of significance was set at alpha=0.05. Homogeneity was assessed using the chi-square test, I2 and by visual inspection of forest plots. If heterogeneity was encountered within groups (P < 0.10), a random effects model was used. All statistical analyses were performed using RevMan 5. Where sufficient data were available, these analyses were repeated within subgroups of patients defined by time of outcome assessment to evaluate sustainability of treatment benefit. Results were pooled based on the diseased artery and stent type.
Summary of Findings
Balloon-expandable stents vs PTA in superficial femoral artery disease
Based on a moderate quality of evidence, there is no significant difference in patency between primary stenting using balloon-expandable bare metal stents and PTA at 6, 12 and 24 months in patients with superficial femoral artery disease. The pooled OR for patency and their corresponding 95% CI are: 6 months 1.26 (0.74, 2.13); 12 months 0.95 (0.66, 1.38); and 24 months 0.72 (0.34. 1.55).
There is no significant difference in clinical improvement, re-interventions, peri and post operative complications, mortality and amputations between primary stenting using balloon-expandable bare stents and PTA in patients with superficial femoral artery. The pooled OR and their corresponding 95% CI are clinical improvement 0.85 (0.50, 1.42); ankle brachial index 0.01 (-0.02, 0.04) re-intervention 0.83 (0.26, 2.65); complications 0.73 (0.43, 1.22); all cause mortality 1.08 (0.59, 1.97) and amputation rates 0.41 (0.14, 1.18).
Self-expandable stents vs PTA in superficial femoral artery disease
Based on a moderate quality of evidence, primary stenting using self-expandable bare metal stents is associated with significant improvement in patency at 6, 12 and 24 months in patients with superficial femoral artery disease. The pooled OR for patency and their corresponding 95% CI are: 6 months 2.35 (1.06, 5.23); 12 months 1.54 (1.01, 2.35); and 24 months 2.18 (1.00. 4.78). However, the benefit of primary stenting is not observed for clinical improvement, re-interventions, peri and post operative complications, mortality and amputation in patients with superficial femoral artery disease. The pooled OR and their corresponding 95% CI are clinical improvement 0.61 (0.37, 1.01); ankle brachial index 0.01 (-0.06, 0.08) re-intervention 0.60 (0.36, 1.02); complications 1.60 (0.53, 4.85); all cause mortality 3.84 (0.74, 19.22) and amputation rates 1.96 (0.20, 18.86).
Balloon expandable stents vs PTA in iliac artery occlusive disease
Based on moderate quality of evidence, despite immediate technical success, 12.23 (7.17, 20.88), primary stenting is not associated with significant improvement in patency, clinical status, treadmill walking distance and reduction in re-intervention, complications, cardiovascular events, all cause mortality, QoL and amputation rates in patients with intermittent claudication caused by iliac artery occlusive disease. The pooled OR and their corresponding 95% CI are: patency 1.03 (0.56, 1.87); clinical improvement 1.08 (0.60, 1.94); walking distance 3.00 (12.96, 18.96); re-intervention 1.16 (0.71, 1.90); complications 0.56 (0.20, 1.53); all cause mortality 0.89 (0.47, 1.71); QoL 0.40 (-4.42, 5.52); cardiovascular event 1.16 (0.56, 2.40) and amputation rates 0.37 (0.11, 1.23). To date no RCTs are available evaluating self-expandable stents in the common or external iliac artery stenosis or occlusion.
Drug-eluting stent vs balloon-expandable bare metal stents in crural arteries
Based on a very low quality of evidence, at 6 months of follow-up, sirolimus drug-eluting stents are associated with a reduction in target vessel revascularization and re-stenosis rates in patients with atherosclerotic lesions of crural (tibial) arteries compared with balloon-expandable bare metal stent. The OR and their corresponding 95% CI are: re-stenosis 0.09 (0.03, 0.28) and TVR 0.15 (0.05, 0.47) in patients with atherosclerotic lesions of the crural arteries at 6 months follow-up. Both types of stents offer similar immediate success. Limitations of this study include: short follow-up period, small sample and no assessment of mortality as an outcome. Further research is needed to confirm its effect and safety.
PMCID: PMC3377569  PMID: 23074395
2.  Intravascular Ultrasound to Guide Percutaneous Coronary Interventions 
Executive Summary
The objective of this health technology policy assessment was to determine the effectiveness and cost-effectiveness of using intravascular ultrasound (IVUS) as an adjunctive imaging tool to coronary angiography for guiding percutaneous coronary interventions.
Intravascular Ultrasound
Intravascular ultrasound is a procedure that uses high frequency sound waves to acquire 3-dimensional images from the lumen of a blood vessel. The equipment for performing IVUS consists of a percutaneous transducer catheter and a console for reconstructing images. IVUS has been used to study the structure of the arterial wall and nature of atherosclerotic plaques, and obtain measurements of the vessel lumen. Its role in guiding stent placement is also being investigated. IVUS is presently not an insured health service in Ontario.
Clinical Need
Coronary artery disease accounts for approximately 55% of cardiovascular deaths, the leading cause of death in Canada. In Ontario, the annual mortality rate due to ischemic heart disease was 141.8 per 100,000 population between 1995 and 1997. Percutaneous coronary intervention (PCI), a less invasive approach to treating coronary artery disease, is used more frequently than coronary bypass surgery in Ontario. The number of percutaneous coronary intervention procedures funded by the Ontario Ministry of Health and Long-term Care is expected to increase from approximately 17, 780 in 2004/2005 to 22,355 in 2006/2007 (an increase of 26%), with about 95% requiring the placement of one or more stents. Restenosis following percutaneous coronary interventions involving bare metal stents occurs in 15% to 30% of the cases, mainly because of smooth muscle proliferation and migration, and production of extracellular matrix. In-stent restenosis has been linked to suboptimal stent expansion and inadequate lesion coverage, while stent thrombosis has been attributed to incomplete stent-to-vessel wall apposition. Since coronary angiography (the imaging tool used to guide stent placement) has been shown to be inaccurate in assessing optimal stent placement, and IVUS can provide better views of the vessel lumen, the clinical utility of IVUS as an imaging tool adjunctive to coronary angiography in coronary intervention procedures has been explored in clinical studies.
A systematic review was conducted to answer the following questions:
What are the procedure-related complications associated with IVUS?
Does IVUS used in conjunction with angiography to guide percutaneous interventions improve patient outcomes compared to angiographic guidance without IVUS?
Who would benefit most in terms of clinical outcomes from the use of IVUS adjunctive to coronary angiography in guiding PCIs?
What is the effectiveness of IVUS guidance in the context of drug-eluting stents?
What is the cost-effectiveness ratio and budget impact of adjunctive IVUS in PCIs in Ontario?
A systematic search of databases OVID MEDLINE, EMBASE, MEDLINE In-Process & Other Non-Indexed Citations, The Cochrane Library, and the International Agency for Health Technology Assessment (INAHTA) database for the period beginning in May 2001 until the day of the search, November 4, 2005 yielded 2 systematic reviews, 1 meta-analysis, 6 randomized controlled trials, and 2 non-randomized studies on left main coronary arteries. The quality of the studies ranged from moderate to high. These reports were combined with reports from a previous systematic review for analysis. In addition to qualitative synthesis, pooled analyses of data from randomized controlled studies using a random effect model in the Cochrane Review Manager 4.2 software were conducted when possible.
Findings of Literature Review & Analysis
Intravascular ultrasound appears to be a safe tool when used in coronary interventions. Periprocedural complications associated with the use of IVUS in coronary interventions ranged from 0.5% in the largest study to 4%. Coronary rupture was reported in 1 study (1/54). Other complications included prolonged spasms of the artery after stenting, dissection, and femoral aneurysm.
Based on pooled analyses of data from randomized controlled studies, the use of intravascular ultrasound adjunctive to coronary intervention in percutaneous coronary interventions using bare metal stents yielded the following findings:
For lesions predominantly at low risk of restenosis:
There were no significant differences in preintervention angiographic minimal lumen diameter between the IVUS-guided and angiography-guided groups.
IVUS guidance resulted in a significantly larger mean postintervention angiographic minimal lumen diameter (weighted mean difference of 0.11 mm, P = .0003) compared to angiographic guidance alone.
The benefit in angiographic minimal lumen diameter from IVUS guidance was not maintained at 6-month follow-up, when no significant difference in angiographic minimal lumen diameter could be detected between the two arms (weighted mean difference 0.08, P = .13).
There were no statistically significant differences in angiographic binary restenosis rates between IVUS-guidance and no IVUS guidance (Odds ratio [OR] 0.87 in favour of IVUS, 95% Confidence Interval [CI] [0.64–1.18], P = 0.37).
IVUS guidance resulted in a reduction in the odds of target lesion revascularization (repeat percutaneous coronary intervention or coronary bypass graft) compared to angiographic guidance alone. The reduction was statistically significant at a follow-up period of 6 months to 1 year, and at a follow-up period of 18 month to 2 years (OR 0.52 in favour of IVUS, 95% CI [0.33–0.81], P = .004).
Total revascularization rate (either target lesion or target vessel revascularization) was significantly lower for IVUS-guided patients at 18 months to 2.5 years after intervention (OR 0.43 in favour of IVUS, 95% CI [0.29–0.63], p < .0001).
There were no statistically significant differences in the odds of death (OR 1.36 in favour of no IVUS, P =0.65) or myocardial infarction (OR 0.95 in favour of IVUS, P = 0.93) between IVUS-guidance and angiographic guidance alone at up to 2.5 years of follow-up
The odds of having a major cardiac event (defined as death, myocardial infarction, and target lesion or target vessel revascularization) were significantly lower for patients with IVUS guidance compared to angiographic guidance alone during follow-up periods of up to 2.5 years (OR 0.53, 95% CI [0.36–0.78], P = 0.001). Since there were no significant reductions in the odds of death or myocardial infarction, the reduction in the odds of combined events reflected mainly the reduction in revascularization rates.
For lesions at High Risk of Restenosis:
There is evidence from one small, randomized controlled trial (n=150) that IVUS-guided percutaneous coronary intervention in long de novo lesions (>20 mm) of native coronary arteries resulted in statistically significant larger minimal lumen Diameter, and statistically significant lower 6-month angiographic binary restenosis rate. Target vessel revascularization rate and the rate of combined events were also significantly reduced at 12 months.
A small subgroup analysis of a randomized controlled trial reported no benefit in clinical or angiographic outcomes for IVUS-guided percutaneous coronary interventions in patients with diabetes compared to those guided by angiography. However, due to the nature and size of the analysis, no firm conclusions could be reached.
Based on 2 small, prospective, non-randomized controlled studies, IVUS guidance in percutaneous coronary interventions of left main coronary lesions using bare metal stents or drug-eluting stents did not result in any benefits in angiographic or clinical outcomes. These findings need to be confirmed.
Interventions Using Drug-Eluting Stents
There is presently no evidence on whether the addition of IVUS guidance during the implantation of drug-eluting stents would reduce incomplete stent apposition, or improve the angiographic or clinical outcomes of patients.
Ontario-Based Economic Analysis
Cost-effectiveness analysis showed that PCIs using IVUS guidance would likely be less costly and more effective than PCIs without IVUS guidance. The upfront cost of adjunctive use of IVUS in PCIs ranged from $1.56 million at 6% uptake to $13.04 million at 50% uptake. Taking into consideration cost avoidance from reduction in revascularization associated with the use of IVUS, a net saving of $0.63 million to $5.2 million is expected. However, since it is uncertain whether the reduction in revascularization rate resulting from the use of IVUS can be generalized to clinical settings in Ontario, further analysis on the budget impact and cost-effectiveness need to be conducted once Ontario-specific revascularization rates are verified.
Factors to be Considered in the Ontario Context
Applicability of Findings to Ontario
The interim analysis of an Ontario field evaluation that compared drug-eluting stents to bare metal stents showed that the revascularization rates in low-risk patients with bare metal stents were much lower in Ontario compared to rates reported in randomized controlled trials (7.2% vs >17 %). Even though IVUS is presently not routinely used in the stenting of low-risk patients in Ontario, the revascularization rates in these patients in Ontario were shown to be lower than those reported for the IVUS groups reported in published studies. Based on this information and previous findings from the Ontario field evaluation on stenting, it is uncertain whether the reduction in revascularization rates from IVUS guidance can be generalized to Ontario. In light of the above findings, it is advisable to validate the reported benefits of IVUS guidance in percutaneous coronary interventions involving bare metal stents in the Ontario context.
Licensing Status
As of January 16, 2006, Health Canada has licensed 10 intravascular ultrasound imaging systems/catheters for transluminal intervention procedures, most as class 4 medical devices.
Current Funding
IVUS is presently not an insured procedure under the Ontario Health Insurance Plan and there are no professional fees for this procedure. All costs related to the use of IVUS are covered within hospitals’ global budgets. A single use IVUS catheter costs approximately $900CDN and the procedure adds approximately 20 minutes to 30 minutes to a percutaneous coronary intervention procedure.
According to an expert consultant, current use of IVUS in coronary interventions in Ontario is probably limited to high-risk cases such as interventions in long lesions, small vessels, and bifurcated lesions for which images from coronary angiography are indeterminate. It was estimated that IVUS is being used in about 6% of all percutaneous coronary interventions at a large Ontario cardiac centre.
Expert Opinion
IVUS greatly enhances the cardiac interventionists’ ability to visualize and assess high-risk lesions such as long lesions, narrow lesions, and bifurcated lesions that may have indeterminate angiographic images. Information from IVUS in these cases facilitates the choice of the most appropriate approach for the intervention.
The use of adjunctive IVUS in PCIs using bare metal stents in lesions predominantly at low risk for restenosis had no significant impact on survival, myocardial infarction, or angiographic restenosis rates up to 2.5 years after intervention.
The use of IVUS adjunctive to coronary angiography in percutaneous coronary interventions using bare metal stents in lesions predominantly at low risk for restenosis significantly reduced the target lesion and target vessel revascularization at a follow-up period of 18 months to 2.5 years.
One small study suggests that adjunctive IVUS in PCIs using bare metal stents in long lesions (>20 mm) significantly improved the 6-month angiographic restenosis rate and one-year target lesion revascularization rate. These results need to be confirmed with large randomized controlled trials.
Based on information from the Ontario field evaluation on stenting, it is uncertain whether the reduction in revascularization rate resulting from the use of IVUS in the placement of bare metal stents can be generalized to clinical settings in Ontario.
There is presently insufficient evidence available to determine the impact of adjunctive IVUS in percutaneous interventions in high-risk lesions (other than long lesions) or in PCIs using drug-eluting stents.
PMCID: PMC3379536  PMID: 23074482
3.  A Rare Case of Acute Myocardial Infarction due to Coronary Artery Dissection and Heparin-Induced Thrombocytopenia 
Case Reports in Medicine  2012;2012:196020.
Although both coronary artery dissection and heparin-induced thrombocytopenia may provoke myocardial infarction, it is extremely rare for both conditions to develop simultaneously in a single patient. We report a case of a 69-year-old woman who sustained a head-on motor vehicle accident with associated chest trauma. During a subsequent hospitalization, she was exposed to subcutaneous heparin and developed significant thrombocytopenia. Shortly thereafter, she re-presented with an acute myocardial infarction. Coronary angiography revealed a spiral dissection with superimposed thrombosis within the right coronary artery, while laboratory testing confirmed the diagnosis of heparin induced thrombocytopenia. She was treated with catheter-based thrombectomy and adjunctive direct thrombin inhibitor therapy, followed by three months of systemic anticoagulation with warfarin. To our knowledge, this represents the first published case of a native vessel myocardial infarction due to the combination of coronary artery dissection and heparin-induced thrombocytopenia.
PMCID: PMC3375156  PMID: 22719771
4.  Pathology of hearts after aortocoronary saphenous vein bypass grafting for coronary artery disease, studied by post-mortem coronary angiography. 
British Heart Journal  1976;38(8):838-859.
A detailed pathological study was made in 10 patients dying up to 13 months after aortocoronary saphenous vein bypass grafting for coronary atherosclerosis. The coronary arteries and vein grafts were investigated by injection with a radio-opaque mass, radiography, dissection, and histology. The report is to some extent historical since the patients died during a period when the operation was first being introduced into two cardiothoracic hospitals. About 80 operations were performed during the time the 10 deaths occurred, a mortality of 12-5 per cent (including cases followed up to 13 months after operation). Seven of the patients were operated on for intractable angina and 3 with a view to aneurysmectomy. All the patients selected for operation were severely disabled despite medical treatment. The main cause of death was extremely severe coronary artery disease and its effects on the left ventricle; in one case, over two-thirds of the left ventricle had been destroyed by infarction before operation. Other causes or contributing causes of death were pulmonary embolism, myocardial infarction complicating angiography (ostial stenosis), and cerebral damage. Ten of the 14 vein grafts (71%) were patent at necropsy. A free flow of injection medium usually occurred between patent grafts and coronary arteries. Thrombosis of a graft was thought to have contributed to death in 3 patients, but not in a fourth who died of pulmonary embolism. Since thrombosis of grafts was usually secondary to poor run-off blood into severely atheromatous coronary arteries, this was also an indirect effect of the advanced coronary arterial disease. In one case, thrombosis followed severe chronic intimal thickening of a graft in place for 13 months. The study of these deaths emphasizes that in some patients the pathological changes in the coronary arteries and left ventricle are too severe for them to benefit from surgery. Vein grafts cannot be expected to distribute blood effectively through grossly narrowed coronary arteries. In addition, when a large part of the left ventricle is infarcted or scarred, it is almost certain that improving the blood supply by grafting will not result in significant regeneration of cardiac muscle. Since the time when this study was made, there have been few deaths among the many vein graft operations subsequently carried out in the hospitals involved. The two most important factors thought responsible for the improvement are the selection of cases more suitable for surgery by continued improvement of diagnostic techniques, and also the employment of more radical surgical procedures in the form of coronary endarterectomy and the insertion of more grafts per patient.
PMCID: PMC483096  PMID: 1086091
5.  External iliac artery thrombosis associated with the ilio-inguinal approach in the management of acetabular fractures: a case report 
The ilio-inguinal approach has come to be used routinely in the management of acetabular fractures involving the anterior wall. Thrombotic complications following surgery via this route are a serious, but rare, complication.
Case presentation
We report the case of a 66-year-old male patient who slipped on an icy pavement and fell on his left hip. He sustained a comminuted acetabular fracture (a transtectal T-fracture with an incomplete posterior stem through the ischial tuberosity), and was operated on five days later, via an ilio-inguinal approach. In the recovery room, his left lower limb was found to be cool and pale. Immediate re-exploration showed a left external iliac artery thrombosis, and thrombectomy was performed. In the surgical management of acetabular fractures, thrombosis of a major pelvic artery is a rare but potentially devastating complication. We discuss the possible aetiology (initial vessel trauma versus iatrogenic, intraoperative arterial injury) and pathomechanism, and wish to draw attention to this complication and to recommend ways in which it can be prevented.
We recommend circulation monitoring in patients with acetabular fractures, especially where nerve blocks and/or deep sedation/analgesia have been used. High-risk patients should be identified and subjected to intensive preoperative screening, including ultrasonography and if necessary angiography.
PMCID: PMC2267470  PMID: 18194519
6.  Coronary Computed Tomography Angiography of Spontaneous Coronary Artery Dissection: A Case Report and Review of the Literature 
Patient: Male, 23
Final Diagnosis: Spontaneous coronary artery dissection
Symptoms: Chest discomfort • chest pain
Medication: —
Clinical Procedure: Coronary computed tomography angiography
Specialty: Radiology
Rare disease
Multidetector computed tomography (MDCT) has gained wide acceptance in the evaluation of the cardiovascular system. Of particular clinical interest is its ability to non-invasively evaluate coronary arteries in patients presenting to the emergency room. In acute coronary syndromes, myocardial ischemia is most often caused by atherosclerosis. We present a case of a rare cause of acute coronary syndrome, spontaneous coronary artery dissection (SCAD), which was initially evaluated with MDCT and followed by intravascular ultrasound (IVUS) and invasive coronary angiography (ICA). We discuss the findings and role of each modality with particular attention to coronary computed tomographic angiography (CCTA) in the diagnosis and management of SCAD. As the use of CCTA in the emergency department continues to rise, radiologists must become familiar with CT appearance of SCAD.
Case Report:
We report the multidetector computed tomography (MDCT), intravascular ultrasound (IVUS), and invasive coronary angiography (ICA) findings in a case of spontaneous coronary artery dissection of the left anterior descending artery in a previously healthy 23-year-old man. The role of coronary computed tomographic angiography (CCTA) in diagnosis and management of this potentially life-threatening condition is discussed.
In the clinical setting of acute coronary syndrome, SCAD must be a consideration, particularly in young patients without clear risk factors for coronary artery disease and in women in the peripartum period. CCTA is a very helpful diagnostic tool to diagnose the condition in a non-invasive manner and to follow up after treatment.
PMCID: PMC4351773  PMID: 25738889
Coronary Angiography; Coronary Vessel Anomalies; Dissection; Multidetector Computed Tomography; Ultrasonography, Interventional
7.  Multi-Detector Computed Tomography Angiography for Coronary Artery Disease 
Executive Summary
Computed tomography (CT) scanning continues to be an important modality for the diagnosis of injury and disease, most notably for indications of the head and abdomen. (1) According to a recent report published by the Canadian Institutes of Health Information, (1) there were about 10.3 scanners per million people in Canada as of January 2004. Ontario had the fewest number of CT scanners per million compared to the other provinces (8 CT scanners per million). The wait time for CT in Ontario of 5 weeks approaches the Canadian median of 6 weeks.
This health technology and policy appraisal systematically reviews the published literature on multidetector CT (MDCT) angiography as a diagnostic tool for the newest indication for CT, coronary artery disease (CAD), and will apply the results of the review to current health care practices in Ontario. This review does not evaluate MDCT to detect coronary calcification without contrast medium for CAD screening purposes.
The Technology
Compared with conventional CT scanning, MDCT can provide smaller pieces of information and can cover a larger area faster. (2) Advancing MDCT technology (8, 16, 32, 64 slice systems) is capable of producing more images in less time. For general CT scanning, this faster capability can reduce the time that patients must stay still during the procedure, thereby reducing potential movement artefact. However, the additional clinical utility of images obtained from faster scanners compared to the images obtained from conventional CT scanners for current CT indications (i.e., non-moving body parts) is not known.
There are suggestions that the new fast scanners can reduce wait times for general CT. MDCT angiography that utilizes a contrast medium, has been proposed as a minimally invasive replacement to coronary angiography to detect coronary artery disease. MDCT may take between 15 to 45 minutes; coronary angiography may take up to 1 hour.
Although 16-slice and 32-slice CT scanners have been available for a few years, 64-slice CT scanners were released only at the end of 2004.
Review Strategy
There are many proven, evidence-based indications for conventional CT. It is not clear how MDCT will add to the clinical utility and management of patients for established CT indications. Therefore, because cardiac imaging, specifically MDCT angiography, is a new indication for CT, this literature review focused on the safety, effectiveness, and cost-effectiveness of MDCT angiography compared with coronary angiography in the diagnosis and management of people with CAD.
This review asked the following questions:
Is the most recent MDCT angiography effective in the imaging of the coronary arteries compared with conventional angiography to correctly diagnose of significant (> 50% lumen reduction) CAD?
What is the utility of MDCT angiography in the management and treatment of patients with CAD?
How does MDCT angiography in the management and treatment of patients with CAD affect longterm outcomes?
The published literature from January 2003 to January 31, 2005 was searched for articles that focused on the detection of coronary artery disease using 16-slice CT or faster, compared with coronary angiography. The search yielded 138 articles; however, 125 were excluded because they did not meet the inclusion criteria (comparison with coronary angiography, diagnostic accuracy measures calculated, and a sample size of 20 or more). As screening for CAD is not advised, studies that utilized MDCT for this purpose or studies that utilized MDCT without contrast media were also excluded. Overall, 13 studies were included in this review.
Summary of Findings
The published literature focused on 16-slice CT angiography for the detection of CAD. Two abstracts that were presented at the 2005 European Congress of Radiology meeting in Vienna compared 64-slice CT angiography with coronary angiography.
The 13 studies focussing on 16-slice CT angiography were stratified into 2 groups: Group 1 included 9 studies that focused on the detection of CAD in symptomatic patients, and Group 2 included 4 studies that examined the use of 16-slice CT angiography to detect disease progression after cardiac interventions. The 2 abstracts on 64-slice CT angiography were presented separately, but were not critically appraised due to the lack of information provided in the abstracts.
16-Slice Computed Tomography Angiography
The STARD initiative to evaluate the reporting quality of studies that focus on diagnostic tests was used. Overall the studies were relatively small (fewer than 100 people), and only about one-half recruited consecutive patients. Most studies reported inclusion criteria, but 5 did not report exclusion criteria. In these 5, the patients were highly selected; therefore, how representative they are of the general population of people with suspicion if CAD or those with disease progression after cardiac intervention is questionable. In most studies, patients were either already taking, or were given, β-blockers to reduce their heart rates to improve image quality sufficiently. Only 6 of the 13 studies reported interobserver reliability quantitatively. The studies typically assessed the quality of the images obtained from 16-slice CT angiography, excluded those of poor quality, and compared the rest with the gold standard, coronary angiography. This practice necessarily inflated the diagnostic accuracy measures. Only 3 studies reported confidence intervals around their measures.
Evaluation of the studies in Group 1 reported variable sensitivity, from just over 60% to 96%, but a more stable specificity, at more than 95%. The false positive rate ranged from 5% to 8%, but the false negative rate was at best under 10% and at worst about 30%. This means that up to one-third of patients who have disease may be missed. These patients may therefore progress to a more severe level of disease and require more invasive procedures. The calculated positive and negative likelihood ratios across the studies suggested that 16-slice CT angiography may be useful to detect disease, but it is not useful to rule out disease. The prevalence of disease, measured by conventional coronoary angiography, was from 50% to 80% across the studies in this review. Overall, 16-slice CT angiography may be useful, but there is no conclusive evidence to suggest that it is equivalent to or better than coronary angiography to detect CAD in symptomatic patients.
In the 4 studies in Group 2, sensitivity and specificity were both reported at more than 95% (except for 1 that reported sensitivity of about 80%). The positive and negative likelihood ratios suggested that the test might be useful to detect disease progression in patients who had cardiac interventions. However, 2 of the 4 studies recruited patients who had been asymptomatic since their intervention. As many of the patients studied were not symptomatic, the relevance of performing MDCT angiography in the patient population may be in question.
64-Slice Computed Tomography Angiography
An analysis from the interim results based on 2 abstracts revealed that 64-slice CT angiography was insufficient compared to coronary angiography and may not be better than 16-slice CT angiography to detect CAD.
Cardiac imaging is a relatively new indication for CT. A systematic review of the literature was performed from 2003 to January 2005 to determine the effectiveness of MDCT angiography (16-slice and 64-slice) compared to coronary angiography to detect CAD. At the time of this report, there was no published literature on 64-slice CT for any indications.
Based on this review, the Medical Advisory Secretariat concluded that there is insufficient evidence to suggest that 16-slice or 64-slice CT angiography is equal to or better than coronary angiography to diagnose CAD in people with symptoms or to detect disease progression in patients who had previous cardiac interventions. An analysis of the evidence suggested that in investigating suspicion of CAD, a substantial number of patients would be missed. This means that these people would not be appropriately treated. These patients might progress to more severe disease and possibly more adverse events. Overall, the clinical utility of MDCT in patient management and long-term outcomes is unknown.
Based on the current evidence, it is unlikely that CT angiography will replace coronary angiography completely, but will probably be used adjunctively with other cardiac diagnostic tests until more definitive evidence is published.
If multi-slice CT scanners are used for coronary angiography in Ontario, access to the current compliment of CT scanners will necessarily increase wait times for general CT scanning. It is unlikely that these newer-generation scanners will improve patient throughput, despite the claim that they are faster.
Screening for CAD in asymptomatic patients and who have no history of ischemic heart disease using any modality is not advised, based on the World Health Organization criteria for screening. Therefore, this review did not examine the use of multi-slice CT for this purpose.
PMCID: PMC3382628  PMID: 23074474
8.  Mechanical thrombectomy using Rotarex system and stent-in-stent placement for treatment of distal femoral artery occlusion secondary to stent fracture – a case report and literature review 
Polish Journal of Radiology  2013;78(3):74-79.
Treatment of peripheral arterial diseases may be distinguished into conservative and interventional management; the latter is divided into surgical and endovascular procedures. Management of peripheral artery stenosis and occlusion with vascular stents is associated with the risk of late complications such as restenosis, stent fracture or dislocation.
Case Report:
A 62-year-old woman with generalized atherosclerosis, particularly extensive in lower limb arteries, was admitted to the Department of Angiology 11 months after having an endovascular procedure performed due to critical ischemia of left lower limb. Because of stent occlusion, a decision to perform angiographic examination of lower limb arteries was made. Examination revealed occlusion of the superficial femoral artery along its entire length, including previously implanted stents. Distal stent was fractured with slight dislocation of the proximal segment. A decision was made to perform mechanical thrombectomy using a Rotarex system followed by a stent-in-stent placement procedure. Follow-up angiography and ultrasound scan performed 24 hours after the procedure revealed a patent vessel with satisfactory blood flow.
Nowadays, imaging diagnostics of peripheral artery stenosis involves non-invasive examinations such as ultrasound, minimally invasive examinations such as angio-MRI and MDCT, or invasive examinations such as DSA and IVUS. DSA examinations are used to confirm significant stenosis or occlusion of a vessel, particularly when qualifying a patient for endovascular treatment. Due to their anatomic location, the superficial femoral artery and the popliteal artery are subject to various forces e.g. those exerted by the working muscles. Mechanical thrombectomy and atherectomy are efficient methods of arterial recanalization used in the treatment of acute, subacute or even chronic occlusions or stenosis of peripheral vessels.
Frequency of angioplasty and vascular stent implantation procedures is increased in patients with peripheral arterial disease, thus increasing the incidence of reported early and late complications such as acute stent thrombosis, restenosis and stent fractures. The Rotarex transcutaneous mechanical thrombectomy system is an efficient method of treating occlusions in arterial stents. It is also safe when performed by experienced operators.
PMCID: PMC3789939  PMID: 24115965
stent fracture; mechanical thrombectomy; femoral artery occlusion
9.  Bleeding and thrombosis in a patient with primary antiphospholipid syndrome using norethisterone: a case report 
Antiphospholipid syndrome is known to be associated with the occurrence of venous and/or arterial thrombosis. There are several factors that might trigger the risk of thrombosis in antiphospholipid syndrome, including drugs, however bleeding is rare. Only a few cases of antiphospholipid syndrome have reported simultaneous bleeding and thrombosis, and only a few of these cases have reported thrombosis induced by norethisterone when used by patients with an underlying risk factor for thromboembolism.
Case presentation
We report the case of a 35-year-old Saudi woman diagnosed with antiphospholipid syndrome with a history of several spontaneous miscarriages and two previous lower limb deep vein thromboses. She had used norethisterone to postpone her menstruation and presented to our institution with severe menorrhagia. During admission, she developed thrombocytopenia, and at the same time she was found to have extensive inferior vena cava and bilateral common iliac thrombosis.
This case report is of interest to rheumatologists, hematologists and radiologists because we have found that the presence of bleeding and thrombocytopenia do not preclude the concomitant occurrence of thrombotic complications of antiphospholipid syndrome. Norethisterone is normally safe to take, but it is not suitable for patients with an increased risk of deep vein thrombosis. Also, the simultaneous management of thrombosis and heavy vaginal bleeding is a challenge for clinicians since there are no evidence-based guidelines regarding the management of these patients.
PMCID: PMC4424544  PMID: 25895835
Antiphospholipid syndrome; Norethisterone; Bleeding; Thrombosis
10.  Rare vascular perforation complicating radial approach to percutaneous coronary angioplasty 
BMJ Case Reports  2013;2013:bcr2012007732.
A transradial arterial approach to coronary angiography and percutaneous coronary intervention has become increasingly embraced by cardiologists as it is associated with decreased vascular complications and allows early mobilisation of patients when compared with transfemoral arterial access. Major vascular complication post-transradial access is uncommon. We describe a very rare case of perforation of the costocervical trunk (a branch of the right subclavian artery at the site of the thoracic inlet) presenting shortly after percutaneous transradial coronary intervention. The resulting rapidly expanding cervical haematoma caused airway compromise necessitating emergent intubation in the catheter laboratory recovery area. Transfemoral catheter coil embolisation of the feeder artery was successful in obliterating blood flow to the perforated vessel with eventual resolution of the neck haematoma.
PMCID: PMC3604458  PMID: 23362057
11.  Rare occurrence of simultaneous coronary artery perforation and intracoronary thrombus formation following angioplasty 
Both coronary artery perforation and intracoronary thrombus formation are life-threatening complications of percutaneous coronary interventions, which rarely occur simultaneously during angioplasty. We herein report a case of stent-related, left circumflex artery perforation, and subsequently acute left main artery thrombosis after the leakage was embolized with 7 microcoils. Intracoronary thromboectomy and systemic anticoagulant therapy were carefully used with good results. This case also represents some of our uncertainties regarding the best management of the patient.
PMCID: PMC3708060  PMID: 23888180
Coronary vessels; Perforation; Thrombosis; Percutaneous coronary interventions; Cardiac tamponade
12.  CT coronary angiography vs. invasive coronary angiography in CHD 
Scientific background
Various diagnostic tests including conventional invasive coronary angiography and non-invasive computed tomography (CT) coronary angiography are used in the diagnosis of coronary heart disease (CHD).
Research questions
The present report aims to evaluate the clinical efficacy, diagnostic accuracy, prognostic value cost-effectiveness as well as the ethical, social and legal implications of CT coronary angiography versus invasive coronary angiography in the diagnosis of CHD.
A systematic literature search was conducted in electronic data bases (MEDLINE, EMBASE etc.) in October 2010 and was completed with a manual search. The literature search was restricted to articles published from 2006 in German or English. Two independent reviewers were involved in the selection of the relevant publications.
The medical evaluation was based on systematic reviews of diagnostic studies with invasive coronary angiography as the reference standard and on diagnostic studies with intracoronary pressure measurement as the reference standard. Study results were combined in a meta-analysis with 95 % confidence intervals (CI). Additionally, data on radiation doses from current non-systematic reviews were taken into account.
A health economic evaluation was performed by modelling from the social perspective with clinical assumptions derived from the meta-analysis and economic assumptions derived from contemporary German sources.
Data on special indications (bypass or in-stent-restenosis) were not included in the evaluation. Only data obtained using CT scanners with at least 64 slices were considered.
No studies were found regarding the clinical efficacy or prognostic value of CT coronary angiography versus conventional invasive coronary angiography in the diagnosis of CHD.
Overall, 15 systematic reviews with data from 44 diagnostic studies using invasive coronary angiography as the reference standard (identification of obstructive stenoses) and two diagnostic studies using intracoronary pressure measurement as the reference standard (identification of functionally relevant stenoses) were included in the medical evaluation.
Meta-analysis of the nine studies of higher methodological quality showed that, CT coronary angiography with invasive coronary angiography as the reference standard, had a sensitivity of 96 % (95 % CI: 93 % to 98 %), specificity of 86 % (95 % CI: 83 % to 89 %), positive likelihood ratio of 6.38 (95 % CI: 5.18 to 7.87) and negative likelihood ratio of 0.06 (95 % CI: 0.03 to 0.10). However, due to non-diagnostic CT images approximately 3.6 % of the examined patients required a subsequent invasive coronary angiography.
Using intracoronary pressure measurement as the reference standard, CT coronary angiography compared to invasive coronary angiography had a sensitivity of 80 % (95 % CI: 61 % to 92 %) versus 67 % (95 % CI: 51 % to 78 %), a specificity of 67 % (95 % CI: 47 % to 83 %) versus 75 % (95 % CI: 60 % to 86 %), an average positive likelihood ratio of 2.3 versus 2.6, and an average negative likelihood ratio 0.3 versus 0.4, respectively.
Compared to invasive coronary angiography, the average effective radiation dose of CT coronary angiography was higher with retrospective electrocardiogram (ECG) gating and relatively similar with prospective ECG gating.
The health economic model using invasive coronary angiography as the reference standard showed that at a pretest probability of CHD of 50 % or lower, CT coronary angiography resulted in lower cost per patient with true positive diagnosis. At a pretest probability of CHD of 70 % or higher, invasive coronary angiography was associated with lower cost per patient with true positive diagnosis. Using intracoronary pressure measurement as the reference standard, both types of coronary angiographies resulted in substantially higher cost per patient with true positive diagnosis.
Two publications dealing explicitly with ethical aspects were identified. The first addressed ethical aspects regarding the principles of beneficence, autonomy and justice, and the second addressed those regarding radiation exposition, especially when used within studies.
The discriminatory power of CT coronary angiography to identify patients with obstructive (above 50 %) coronary stenoses should be regarded as “high diagnostic evidence”, to identify patients without coronary stenoses as “persuasive diagnostic evidence”. The discriminatory power of both types of coronary angiography to identify patients with or without functionally relevant coronary stenoses should be regarded as “weak diagnostic evidence”.
It can be assumed that patients with a high pretest probability of CHD will need invasive coronary angiography and patients with a low pretest probability of CHD will not need subsequent revascularisation. Therefore, CT coronary angiography may be used before performing invasive coronary angiography in patients with an intermediate pretest probability of CHD.
For identifying or excluding of obstructive coronary stenosis, CT coronary angiography was shown to be more cost-saving at a pretest probability of CHD of 50 % or lower, and invasive coronary angiography at a pretest probability of CHD of 70 % or higher. The use of both types of coronary angiography to identify or to exclude functionally relevant coronary stenoses should be regarded as highly cost-consuming.
With regard to ethical, social or legal aspects, the following possible implications were identified: under-provision or over-provision of health care, unnecessary complications, anxiety, social stigmatisation, restriction of self-determination, unequal access to health care, unfair resource distribution and legal disputes.
From a medical point of view, CT coronary angiography using scanners with at least 64 slices should be recommended as a test to rule out obstructive coronary stenoses in order to avoid inappropriate invasive coronary angiography in patients with an intermediate pretest probability of CHD. From a health economic point of view, this recommendation should be limited to patients with a pretest probability of CHD of 50 % or lower.
From a medical and health economic point of view, neither CT coronary angiography using scanners with at least 64 slices nor invasive coronary angiography may be recommended as a single diagnostic test for identifying or ruling out functionally relevant coronary stenoses.
To minimise any potential negative ethical, social and legal implications, the general ethical and moral principles of benefit, autonomy and justice should be considered.
PMCID: PMC3334923  PMID: 22536300
CHD; coronary angiography; coronary disease; coronary heart disease; cost-benefit-analysis; diagnosis; EBM; evidence based medicine; evidence-based medicine; health technology assessment; health-economic analysis; HTA; humans; meta-analysis; meta-analysis as topic; review literature as topic; stenosis; systematic review
13.  Arteriovenous fistula as a complication of transradial coronary angiography: a case report 
Iatrogenic arteriovenous fistula is a vascular condition that may result from coronary angiography. Many case reports have described arteriovenous fistula occurrence after coronary angiography using the transfemoral access route, but rarely as a complication of using the transradial approach. We report a rare case of a patient with arteriovenous fistula following transradial artery coronary angiography.
Case presentation
A 62-year-old Caucasian man underwent emergent coronary angiography using the right radial artery approach. One month after angiography, he discovered a turbulent sound near the access site. A right radial arteriovenous fistula was found upon duplex ultrasound investigation. The patient was treated conservatively. At 1-year follow-up, the arteriovenous fistula was unchanged and the patient remained hemodynamically stable and asymptomatic.
Iatrogenic arteriovenous fistula is a rare vascular complication of transradial artery coronary angiography. The natural history of arteriovenous fistula is benign and is thought to resolve spontaneously; therefore, a conservative approach, as opposed to surgical ligation, is recommended as the first-line treatment.
PMCID: PMC3562163  PMID: 23316970
14.  Sinus arrest following right coronary artery stent implantation 
Sinus arrest rarely occurs during acute myocardial infarction involving the right coronary artery (RCA) and sinus node (SN) artery. We report a rare case of sinus arrest caused by SN artery occlusion following RCA stenting. A 56-year-old woman with a significant history of RCA stenosis with prior bare metal stenting, presented to the emergency department with anginal chest pain. Initial work up showed significant elevation of cardiac troponin T with T-wave inversion in the inferior leads on electrocardiogram (ECG). Coronary angiography revealed a 90% stenosis of midportion of the RCA, mild occlusion in the left anterior descending coronary and left circumflex coronary arteries. Stenting was performed on the RCA lesion. Immediately after undergoing those interventions, thrombosis developed and occluded SN artery. Electrocardiogram showed junctional escape rhythm without P waves at a heart rate of 30 beats per minute, suggesting sinus arrest. The clot in the SN artery was identified and thrombectomy was performed. Neither symptoms nor hypotension were identified during this arrhythmia. Six days later, normal sinus rhythm began to appear on EKG with improving heart rate, and patient still remained completely hemodynamically stable. Pre-discharge exercise stress test had shown 50% predicted heart rate without ST segment change. Sinus node dysfunction is commonly related to degenerative processes, and rarely caused by thrombosis in the SN artery. In our case, we emphasize the potential complication of sinus arrest after RCA stent implantation.
PMCID: PMC3317869  PMID: 22433667
Sinus; Arrest; RCA; Stent; Implantation
15.  Efficacy of Transradial Cerebral Angiography in the Elderly 
Transradial angiography has become popular among many cardiologists as a diagnostic and therapeutic tool. However, transradial cerebral angiography is not utilized to the same extent. The purpose of this study is to present our experience regarding the usefulness of transradial cerebral angiography, especially in elderly patients.
Between May 2011 and February 2012, a total of 126 cerebral angiographies were performed via a transradial approach in a single center. Of them, only 47 patients were over 60 years old. In our institution, we shifted the initial access from the right femoral artery to the right radial artery in all patients requiring cerebral angiography in 2011. We did not attempt radial access in 40 cases for variable reasons.
The procedural success rate was 92.2%. We have four failures of transradial angiography; two because of loop formations of the radial and brachial artery and two due to multiple puncture failures. All supra-aortic vessels were successfully catheterized. However, the selective catheterization rates of the left side distal vessels were lower, as success rates were 89.7% for the right internal carotid artery and 75% for the left internal carotid artery. Procedure-related vascular complications, such as puncture site hematoma, hand ischemia, pseudoaneurysm, arteriovenous fistula and arterial dissection were not observed in our series. However, intraprocedural thrombosis developed in one patient, which was resolved completely by intraarterial thrombolytic agents.
With advancing patient's age, we believe that transradial cerebral angiography is a useful tool to decrease patient's discomfort and more effectively manage the vessel tortuosity.
PMCID: PMC3698230  PMID: 23826476
Angiography; Cerebral angiography; Radial artery; Transradial
16.  Use of Internal Endoconduits as an Adjunct to Endovascular Aneurysm Repair in the Setting of Challenging Aortoiliac Anatomy 
Annals of vascular surgery  2009;24(1):114.e7-114.e11.
The combination of Trans-Atlantic Intersociety Consensus (TASC) D aortoiliac occlusive disease as well as a symptomatic abdominal aortic aneurysm (AAA) is not a common occurrence. Extensive calcified atherosclerotic disease, occlusions, and small iliofemoral segmental arteries make transfemoral access difficult, if not impossible, for endovascular aneurysm repair (EVAR) in these patients. We present a case in which “controlled rupture” of the external iliac artery with a covered stent allowed transfemoral delivery of an aortouni-iliac stent graft with a completion femoral-to-femoral bypass. The patient is a 60-year-old male with a 5.3 cm symptomatic infrarenal AAA and a history of one block right leg claudication. Preoperative computed tomography angiography revealed the patient to have occlusion of the right common iliac artery, extensive calcified stenoses of his aortoiliac segments, and a prohibitively small left external iliac artery, which measured 4.5 mm at its narrowest diameter. The patient, despite discussions concerning the suitability of his iliac arteries as conduits for the delivery of the stent graft, insisted on an endovascular approach to lessen his chances of postoperative sexual dysfunction as well as minimize his length of stay. Access was obtained through bilateral femoral artery cutdowns, and attempts at dilating the left external iliac artery using 16-French dilators were performed without success. An 8 mm × 5 cm covered self-expanding stent was deployed in the diseased 4.5 mm left external iliac artery, followed by angioplasty performed with an 8 mm noncompliant balloon to disrupt the vessel. This endoconduit now allowed accommodation of our 18-French introducer for the aortouni-iliac stent graft. The operation was completed with a femoral—femoral bypass. Flow to both hypogastric arteries was preserved. We believe use of such techniques will ultimately expand the number of patients eligible for EVAR and avoid devastating access-related complications.
PMCID: PMC2897233  PMID: 19748213
17.  Internal Mammary Artery Graft Dissection: A Case-Based Retrospective Study and Brief Review 
Texas Heart Institute Journal  2014;41(6):653-656.
The left internal mammary artery is the preferred graft for treating left anterior descending coronary artery disease. Dissection is a rare but grave sequela of internal mammary artery graft angiography. The available medical literature is scant, perhaps as a result of under-reporting.
We report a case in which dissection of the internal mammary artery graft occurred during diagnostic angiography, and we discuss its management. In addition, we review the available literature and provide a retrospective analysis of the data from our own catheterization laboratory. In our single-center analysis of 542 cases of selective internal mammary artery graft angiography, we found only the single case of internal mammary artery graft dissection (0.2%) that we report here. Our review of the literature revealed 7 reported cases of internal mammary artery graft dissection, 3 of which were iatrogenic. There were no identifiable risk factors for such dissection. After treatment with angioplasty and stenting, all patients had good outcomes during follow-up.
PMCID: PMC4251342  PMID: 25593535
Aneurysm, dissecting/therapy; angioplasty, balloon, coronary; coronary artery bypass; internal mammary artery-coronary artery anastomosis/adverse effects; mammary arteries/dissection/injuries/surgery; postoperative complications; dissection; stents; treatment
18.  Diagnosis and treatment of concomitant aortic and coronary disease: a retrospective study and brief review. 
Texas Heart Institute Journal  1999;26(3):182-188.
Coronary arteriosclerosis seriously complicates the surgical treatment of aortic diseases. The aim of our retrospective study was to determine the incidence of coronary artery disease among our surgical patients in treatment for aortic dissection or aneurysm, and to determine whether coronary intervention before aortic surgery appears to affect outcomes. Between 1 January 1993 and 1 March 1998, our center treated 253 patients for aortic dissection or aneurysm. We examined these cases retrospectively for information on diagnostic and treatment methods, both for the aortic lesions and for concomitant coronary arteriosclerosis. Aortic dissection had been detected in 86 (33.9%) patients and aortic aneurysm in 167 (66.1%). Coronary angiography was performed to search for concomitant coronary artery disease in 29 (33.8%) patients with dissection and in 112 (67.1%) patients with aneurysm; of these, 11 (12. 7%) and 54 (32.3%), respectively, were found to have coronary disease. Among 43 patients with abdominal aortic aneurysm in whom coronary angiography was performed, concomitant coronary disease was detected in 36 (83.7%). Coronary artery bypass surgery was performed in 10 patients who had dissection and in 30 patients who had aneurysm; percutaneous transluminal coronary angioplasty was performed in 7 patients who had aneurysm. Perioperative mortality rates in the dissection and aneurysm groups, overall, were 23.2% and 13.8%, respectively Unfortunately, the prospective, random clinical study that would be necessary to prove the case for or against preoperative coronary angiography among subsets of patients in need of aortic repair would raise ethical questions, given the strength of the information already in our possession, gathered by less formal methods. Our study reinforces existing evidence that preoperative angiography can reduce mortality and morbidity in the elective repair of aortic aneurysm, especially thoracic or abdominal aneurysm. However, angiography should not be performed routinely in cases of aortic dissection and should be withheld in cases of type A dissection.
PMCID: PMC325637  PMID: 10524739
19.  Detection of Postcoronary Stent Complication: Utility of 64-Slice Multidetector CT  
Case Reports in Cardiology  2012;2012:214760.
Coronary stent fracture is a known complication of coronary arterial stent placements. Multiple long-term risks are also associated with drug eluting stents. 64-slice multidetector CT (MDCT) coronary angiography has been shown to detect poststent complications such as instent stenosis, thrombosis, stent migration and stent fractures. We report a case of stent fracture in a patient who underwent RCA stenting with associated RCA perforation and almost complete thrombosis of the RCA and peristent fibrinoid collection. This is a rare case of stent fracture with perforation of the RCA. The paper highlights the role of 64-row multidetector computed tomography (MDCT) in evaluation of such poststent placement complications.
PMCID: PMC4007751  PMID: 24826238
20.  Spontaneous coronary artery dissection causing acute myocardial infarction in a 62-year-old postmenopausal woman without co-morbidities: a case report 
Spontaneous coronary artery dissection is an important yet rare cause of acute coronary syndrome. The available literature shows a higher risk factor for women, notably during pregnancy and puerperium. The incidence in postmenopausal women is exceedingly rare, and is more commonly seen in association with concurrent predisposing factors.
We illustrate an extremely rare case of a 62-year-old post-menopausal woman presenting with an acute myocardial infarction secondary to spontaneous dissection of the left anterior descending artery. Subsequent investigations did not reveal the presence of any co-morbidities.
To the best of our knowledge, our patient is one of the oldest documented cases of spontaneous coronary artery dissection on record, and is notable for having no known underlying risk factors for development of spontaneous coronary artery dissection.
Given the paucity of literature on spontaneous coronary artery dissection, particularly in postmenopausal women, we believe this case will provide further insight into the clinical presentation and management of this rare entity.
Case presentation
A 62-year-old previously healthy postmenopausal Hispanic woman presented with chest pain and was found to have an ST elevation myocardial infarction. Cardiac catheterization revealed a dissection in her left anterior descending artery. Revascularization was deferred; our patient received appropriate medical management and remained asymptomatic. A full panel of tests was done to exclude underlying connective tissue disorders and vasculitis. On subsequent follow-up, our patient continued to do well and all work-up was reported as negative.
We describe the varied presentation and subsequent management of a case of spontaneous coronary artery dissection and highlight the importance of considering spontaneous coronary artery dissection as a differential diagnosis even in older, postmenopausal women.
The consequences of a delay in diagnosis and appropriate management are associated with a high mortality and morbidity; hence we believe that reporting all cases of spontaneous coronary artery dissection, particularly in postmenopausal women, will add invaluable information to the limited literature on this rare condition.
PMCID: PMC3539931  PMID: 23272729
21.  Left main coronary artery dissection after blunt chest trauma presented as acute anterior myocardial infarction: assessment by intravascular ultrasound: a case report. 
Journal of Korean Medical Science  1998;13(3):325-327.
Coronary artery injury after blunt chest trauma is very rare, but this can result in a serious acute myocardial infarction. Coronary artery dissection is an uncommon complication of thoracic injuries. We report a case of a 17-year-old male who was presented with an anterior myocardial infarction following blunt chest trauma after a bicycle accident. His coronary angiography revealed aneurysmal dilatation with dissection of the distal left main stem coronary artery. Intravascular ultrasound showed a dissecting flap at the left main stem coronary artery. The patient was treated conservatively and discharged without serious sequelae. When symptoms and electrocardiographic findings are compatible with acute myocardial infarction, careful evaluation is important in patients with thoracic injuries for proper management. If the patient is stable, medical therapy may be appropriate. But early intervention should be considered in the presence of ongoing myocardial ischemia.
PMCID: PMC3054493  PMID: 9681815
22.  Mechanisms of Stroke after Intracranial Angioplasty and Stenting in the SAMMPRIS Trial 
Neurosurgery  2013;72(5):777-795.
Enrollment in the Stenting and Aggressive Medical Management for the Prevention of stroke in Intracranial Stenosis (SAMMPRIS) trial was halted owing to higher than expected 30-day stroke rates in the stenting arm. Improvement in peri-procedural stroke rates from angioplasty and stenting for intracranial atherosclerotic disease (ICAD) requires an understanding of the mechanisms of these events.
To identify the types and mechanisms of peri-procedural stroke after angioplasty and stenting for ICAD.
Patients that suffered a hemorrhagic or ischemic stroke or a cerebral infarct with temporary signs (CITS) within 30 days of attempted angioplasty and stenting in SAMMPRIS were identified. Study records, including case report forms, procedure notes, and imaging were reviewed. Strokes were categorized as ischemic or hemorrhagic. Ischemic strokes were categorized as perforator territory, distal embolic, or delayed stent thrombosis. Hemorrhagic strokes were categorized as subarachnoid or intraparenchymal. Causes of hemorrhage (wire perforation, vessel rupture) were recorded.
Three patients suffered an ischemic stroke after diagnostic angiography. Two were unrelated to the procedure. Twenty-one patients suffered an ischemic stroke (n= 19) or CITS (n=2) within 30 days of angioplasty and stenting. Most (n=15) were perforator territory and many of these occurred after angiographically successful angioplasty and stenting of the basilar artery (n = 8). Six patients suffered subarachnoid hemorrhage (three from wire perforation) and seven a delayed intraparenchymal hemorrhage.
Efforts at reducing complications from angioplasty and stenting for ICAD must focus on reducing the risks of regional perforator infarction, delayed intraparenchymal hemorrhage, and wire perforation.
PMCID: PMC3696348  PMID: 23328689
Angioplasty and Stenting; Stroke; Hemorrhage
23.  Optimal management of renal artery fibromuscular dysplasia 
Fibromuscular dysplasia (FMD) is a nonatherosclerotic, noninflammatory angiopathy of unknown cause affecting medium-sized (most commonly renal) arteries and causing renovascular hypertension. The most common medial multifocal type of FMD (with the “string of beads” appearance) is more than four times more prevalent in females than in males. FMD accounts for up to 10% of cases of renovascular hypertension. Compared with patients with atherosclerotic renal artery stenosis, patients with FMD are younger, have fewer risk factors for atherosclerosis, and a lower occurrence of atherosclerosis in other vessels. The etiology is multifactorial, including vessel wall ischemia and smoking, as well as hormonal and genetic factors. Intra-arterial digital subtraction angiography is still the gold standard for exclusion or confirmation of renal artery stenosis caused by FMD, at least in young patients, who more often have lesions in branches of the renal artery. For FMD patients with atherosclerosis and those who are older (>50–55 years), significant renal artery stenosis may be confirmed or excluded with ultrasonography. The FMD lesion is typically truncal or distal, whereas atherosclerotic lesions are more often proximal or ostial. Treatment options are medical, endovascular (percutaneous transluminal renal angioplasty [PTRA]), and surgical. Invasive treatment should be considered when hypertension cannot be controlled with antihypertensive drugs and in patients with impaired renal function or ischemic nephropathy. PTRA has become the treatment of choice and normally yields good results, especially in unifocal disease and young patients. Pressure gradients are normally completely abolished, and there is no indication for stent placement. Surgical revascularization is indicated after PTRA complications; thrombosis, perforation, progressive dissection, repeated PTRA failure or restenosis. Centralization of handling is recommended.
PMCID: PMC4122560  PMID: 25114536
fibromuscular dysplasia; renal artery stenosis; arterial hypertension; percutaneous transluminal renal angioplasty; renal artery surgery
24.  Painless Aortic Dissection Presenting as Paraplegia 
Texas Heart Institute Journal  2012;39(2):273-276.
Acute dissection of the aorta can be life-threatening. As a presenting manifestation of aortic dissection, neurologic complications such as paraplegia are rare.
Herein, we report the case of a 51-year-old man who presented with sudden-onset paraplegia and ischemia of the legs, with no chest or back pain. His medical history included coronary artery bypass grafting. Physical examination revealed pulseless lower extremities, and computed tomography showed aortic dissection from the ascending aorta to the common iliac arteries bilaterally. A lumbar catheter was inserted for cerebrospinal fluid drainage, and axillary arterial cannulation was established. With the use of cardiopulmonary bypass, the aortic dissection was corrected, and the previous coronary artery grafts were reattached. The surgery restored spinal and lower-extremity perfusion, and the patient walked unaided from the hospital upon his discharge 5 days later.
Although acute aortic dissection presenting as paraplegia is rare, it should be considered in patients who have pulseless femoral arteries bilaterally and sudden-onset paraplegia, despite no pain in the chest or back. Prompt diagnosis and intervention can prevent morbidity and death.
PMCID: PMC3384028  PMID: 22740752
Aneurysm, dissecting/complications/diagnosis/surgery; aortic aneurysm/complications/diagnosis/surgery; diagnosis, differential; extremities/blood supply; ischemia/complications; pain/physiopathology; paraplegia/etiology/physiopathology; spinal cord ischemia/etiology/surgery; treatment outcome
25.  Prevalence of normal coronary angiography in the acute phase of suspected ST-elevation myocardial infarction: Experience from the PRAGUE studies 
The Canadian Journal of Cardiology  2006;22(13):1147-1152.
Acute ST-elevation myocardial infarction in patients with normal coronary arteries has previously been described, but coronary angiography in these patients was performed after the acute phase of the infarction. It is possible that these patients did not have normal angiograms during the acute phase (transient coronary thrombosis or spasm were usually suspected to be the cause). Information on the prevalence of truly normal coronary angiograms during the acute phase of a suspected ST-elevation myocardial infarction is lacking.
The PRimary Angioplasty in patients transferred from General community hospitals to specialized PTCA Units with or without Emergency thrombolysis-1 (PRAGUE-1) and PRAGUE-2 studies enrolled 1150 patients with ST-elevation acute myocardial infarction, in whom 625 coronary angiograms were performed within 2 h of the initial electrocardiogram. A simultaneous registry included an additional 379 coronary angiograms performed during the ST-elevation phase of a suspected myocardial infarction. Thus, a total of 1004 angiograms were retrospectively analyzed. A normal coronary angiogram was defined as one with the absence of any visible angiographic signs of atherosclerosis, thrombosis or spontaneous spasm.
Normal coronary angiograms were obtained for 26 patients (2.6%). Among these, the diagnosis at discharge was a small myocardial infarction in seven patients (0.7%), acute (peri)myocarditis in five patients, dilated cardiomyopathy in four patients, hypertension with left ventricular hypertrophy in three patients, pulmonary embolism in two patients and misinterpretation of the electrocardiogram (ie, no cardiac disease) in five patients. Seven patients with small infarctions underwent angiography within 30 min to 90 min of complete relief of the signs of acute ischemia, and thus, angiograms during pain were not taken. None of the 898 patients catheterized during ongoing symptoms of ischemia had a normal coronary angiogram. Spontaneous coronary spasm as the only cause (without underlying coronary atherosclerosis) for the evolving infarction was not seen among these 898 patients. Thus, the causes of the seven small infarcts in patients with normal angiograms remain uncertain.
The observed prevalence of normal coronary angiography in patients presenting with acute chest pain and ST elevations was 2.6%. Most of these cases were misdiagnoses, not infarctions. A normal angiogram during a biochemically confirmed infarction is extremely rare (0.7%) and was not seen during the ongoing symptoms of ischemia.
PMCID: PMC2569046  PMID: 17102833
Acute myocardial infarction; Coronary spasm; Normal coronary angiography; ST elevation

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