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1.  Midterm results after arterial switch operation for transposition of the great arteries: a single centre experience 
The arterial switch operation (ASO) has become the surgical approach of choice for d-transposition of the great arteries (d-TGA). There is, however an increased incidence of midterm and longterm adverse sequelae in some survivors. In order to evaluate operative risk and midterm outcome in this population, we reviewed patients who underwent ASO for TGA at our centre.
In this retrospective study 52 consecutive patients with TGA who underwent ASO between 04/1991 and 12/1999 were included. To analyze the predictors for mortality and adverse events (coronary stenoses, distortion of the pulmonary arteries, dilatation of the neoaortic root, and aortic regurgitation), a multivariate analysis was performed. The follow-up time was ranged from 1–10 years (mean 5 years, cumulative 260 patient-years).
All over mortality rate was 15.4% and was only observed in the early postoperative period till 1994. The predictors for poor operative survival were low APGAR-score, older age at surgery, and necessity of associated surgical procedures. Late re-operations were necessary in 6 patients (13.6%) and included a pulmonary artery patch enlargement due to supravalvular stenosis (n = 3), coronary revascularisation due to coronary stenosis in a coronary anatomy type E, aortic valve replacement due to neoaortic valve regurgitation (n = 2), and patch-plasty of a pulmonary vein due to obstruction (n = 1). The dilatation of neoaortic root was not observed in the follow up.
ASO remains the procedure of choice for TGA with acceptable early and late outcome in terms of overall survival and freedom of reoperation. Although ASO is often complex and may be associated with morbidity, most patients survived without major complications even in a small centre.
PMCID: PMC3487745  PMID: 22958234
Arterial switch operation; Transposition of great arteries; Midterm outcome
2.  Long-Term Outcomes After an Arterial Switch Operation for Simple Complete Transposition of the Great Arteries 
Korean Circulation Journal  2010;40(1):23-30.
Background and Objectives
Although coronary artery obstruction, aortic insufficiency (AI), and pulmonary stenosis (PS) have been reported after arterial switch operation (ASO), limited long-term studies on ASO exist. Our study aimed to examine long-term outcomes after ASO for simple complete transposition of the great arteries (TGA).
Subjects and Methods
All 108 patients with simple complete TGA who underwent ASO at Seoul National University Children's Hospital between 1987 and 2004 were enrolled. We retrospectively reviewed the patients' medical records and the results of various functional and imaging studies.
Among 108 cases of ASO for simple TGA, 96 have been followed-up through the present time (mean follow-up duration was 11.7±8.6 years: range= 4 to 23 years). The 20-year rates of freedom from significant AI, PS, and coronary obstruction were 78.6%, 67.8%, and 95.8%, respectively. AI showed a tendency to progress as follow-up time increased in 21.4% of the population studied (p=0.014); however, AS, PS, and PI showed no such progression. Late coronary artery occlusion was not associated with the initial coronary arterial pattern. Re-operations were done for 13 patients (13.5%) at an average of 8±4.3 years after ASO. The survival rate was 96%, while the re-operation-free was 90% at 10 years and 83% at 20 years. Most patients showed normal physical growth with good activity {98%; New York Heart Association (NYHA) class 1 activity} and normal development (96%).
Although most patients showed normal physical growth and development after successful ASO, meticulous long-term follow-up is necessary because of progressive AI and coronary complications.
PMCID: PMC2812794  PMID: 20111649
Transposition of great vessels; Outcomes assessment, patient; Coronary arteries; Aortic valve insufficiency; Stenosis, pulmonary
3.  Center Variation in Hospital Costs for Patients Undergoing Congenital Heart Surgery 
Congenital heart disease consumes significant health care resources; however, there are limited data regarding factors impacting resource utilization. The purpose of this study was to evaluate variation between centers in total hospital costs for four congenital heart operations of varying complexity, and associated factors.
Methods and Results
The Premier Database was used to evaluate total cost in children undergoing isolated atrial septal defect (ASD) repair, ventricular septal defect (VSD) repair, tetralogy of Fallot (TOF) repair, or arterial switch operation (ASO) from 2001-2007. Mixed models were used to evaluate the impact of center on total hospital costs adjusting for patient and center characteristics and length of stay (LOS).
A total of 2,124 patients were included: 719 ASD (19 centers), 792 VSD (20 centers), 420 TOF (17 centers), and 193 ASO (13 centers). Total cost increased with complexity of operation from median $12,761 (ASD repair) to $55,430 (ASO). In multivariable analysis, models which accounted for center effects vs. those which did not performed significantly better for all four surgeries (all p ≤ 0.01). The proportion of total cost variation explained by center was 19% (ASD repair), 11% (VSD repair), 6% (TOF repair), and 3% (ASO). Higher volume centers had significantly lower hospital costs for ASD and VSD repair, but not for TOF repair and ASO.
Total hospital costs varied significantly by center for all congenital heart surgeries evaluated, even after adjustment for patient and center characteristics and LOS. Differences among centers were most prominent for lower complexity procedures.
PMCID: PMC3326639  PMID: 21505154
heart defects; congenital; cost
4.  Arterial Switch Operation in Patients with Intramural Coronary Artery: Early and Mid-term Results 
The intramural coronary artery has been known as a risk factor for early death after an arterial switch operation (ASO). We reviewed the morphological characteristics and evaluated the early and mid-term results of ASO for patients with an intramural coronary artery.
Materials and Methods
From March 1994 to September 15th 2010, 158 patients underwent ASO at Dong-A and Pusan National University Hospitals for repair of transposition of the great arteries and double outlet right ventricle. Among these patients, 14 patients (8.9%) had an intramural coronary artery. Mean age at operation was 13.4±10.2 days (4 to 39 days) and mean body weight was 3.48±0.33 kg (2.88 to 3.88 kg). All patients except one were male. Eight patients had TGA/IVS and 4 patients had an aortic arch anomaly. Two patients (14.3%) had side-by-side great artery relation, of whom one had an intramural right coronary artery and the other had an intramural left anterior descending coronary artery. Twelve patients had anterior-posterior relation, all of whom had an intramural left coronary artery (LCA). The aortocoronary flap technique was used in coronary transfer in 8 patients, of whom one patient required a switch to the individual coronary button technique 2 days after operation because of myocardial ischemia. An individual coronary button implantation technique was adopted in 6, of whom 2 patients required left subclavian artery free graft to LCA during the same operation due to LCA injury during coronary button mobilization and LCA torsion.
There was 1 operative death (7.1%), which occurred in the first patient in our series. This patient underwent an aortocoronary flap procedure for coronary transfer combining aortic arch repair. Overall operative mortality for 144 patients without an intramural coronary artery was 13.2% (19/144). There was no statistical difference in operative mortality between the patients with and without an intramural coronary artery (p>0.1). There was no late death. The mean follow-up duration was 52.1±43.0 months (0.5 to 132 months). One patient who had a subclavian artery free graft required LCA stenting 6.5 years after surgery for LCA anastomotic site stenosis. No other surviving patient needed any intervention for coronary problems. All patients had normal ventricular function at latest echocardiography and were in NYHA class 1.
The arterial switch operation in Transposition of Great Arteries or Double Outlet Right Ventricle patients with intramural coronary can be performed with low mortality; however, there is a high incidence of intraoperative or postoperative coronary problems, which can be managed with conversion to the individual coronary button technique and a bypass procedure using a left subclavian free graft. Both aortocoronary flap and individual coronary button implantation techniques for coronary transfer have excellent mid-term results.
PMCID: PMC3249286  PMID: 22263137
Congenital heart disease; Transposition of the great arteries; Arterial switch operation; Coronary artery; Coronary artery anatomy
5.  Richard E. Clark Paper: Variation in Outcomes for Benchmark Operations: An analysis of the STS Congenital Heart Surgery Database 
The Annals of Thoracic Surgery  2011;92(6):2184-2192.
We evaluated outcomes for common operations in the STS Congenital Heart Surgery Database (STS-CHSDB) to provide contemporary benchmarks and examine variation between centers.
Patients undergoing surgery from 2005-2009 were included. Centers with>10% missing data were excluded. Discharge mortality and postoperative length of stay (PLOS) among patients discharged alive were calculated for eight benchmark operations of varying complexity. Power for analyzing between-center variation in outcome was determined for each operation. Variation was evaluated using funnel plots and Bayesian hierarchical modeling.
18,375 index operations at 74 centers were included in the analysis of eight benchmark operations. Overall discharge mortality (range) was: ventricular septal defect repair (VSD) 0.6% (0%–5.1%), tetralogy of Fallot repair (TOF) 1.1% (0%–16.7%), complete atrioventricular canal repair (AVC) 2.2% (0%–20%), arterial switch (ASO) 2.9% (0%–50%), ASO+VSD 7.0% (0%–100%), Fontan 1.3% (0%–9.1%), truncus repair 10.9% (0%–100%), Norwood 19.3% (2.9%–100%). Funnel plots revealed the number of centers characterized as outliers were: VSD=0, TOF=0, AVC=1, ASO=3, ASO+VSD=1, Fontan=0, Truncus=4, Norwood=11. Power calculations showed statistically meaningful comparisons of mortality rates between centers could only be made for Norwood, for which the Bayesian-estimated range (95% Probability Interval) was 7.0% (3.7%-10.3%) to 41.6% (30.6%-57.2%). Between-center variation in PLOS was analyzed for all operations and was larger for more complex operations.
This analysis documents contemporary benchmarks for common pediatric cardiac surgical operations and the range of outcomes among centers. Variation was most prominent for the more complex operations. These data may aid in quality assessment and quality improvement initiatives.
PMCID: PMC3263755  PMID: 22115229
database; outcomes
6.  Evaluation of a comprehensive cardiovascular magnetic resonance protocol in young adults late after the arterial switch operation for d-transposition of the great arteries 
In adults with prior arterial switch operation (ASO) for d-transposition of the great arteries, the need for routine coronary artery assessment and evaluation for silent myocardial ischemia is not well defined. In this observational study we aimed to determine the value of a comprehensive cardiovascular magnetic resonance (CMR) protocol for the detection of coronary problems in adults with prior ASO for d-transposition of the great arteries.
Adult ASO patients (≥18 years of age) were recruited consecutively. Patients underwent a comprehensive stress perfusion CMR protocol that included measurement of biventricular systolic function, myocardial scar burden, coronary ostial assessment and myocardial perfusion during vasodilator stress by perfusion CMR. Single photon emission computed tomography (SPECT) was performed on the same day as a confirmatory second imaging modality. Stress studies were visually assessed for perfusion defects (qualitative analysis). Additionally, myocardial blood flow was quantitatively analysed from mid-ventricular perfusion CMR images. In unclear cases, CT coronary angiography or conventional angiography was done.
Twenty-seven adult ASO patients (mean age 23 years, 85% male, 67% with a usual coronary pattern; none with a prior coronary artery complication) were included in the study. CMR stress perfusion was normal in all 27 patients with no evidence of inducible perfusion defects. In 24 cases the coronary ostia could conclusively be demonstrated to be normal. There was disagreement between CMR and SPECT for visually-assessed perfusion defects in 54% of patients with most disagreement due to false positive SPECT.
Adult ASO survivors in this study had no CMR evidence of myocardial ischemia, scar or coronary ostial abnormality. Compared to SPECT, CMR provides additional valuable information about the coronary artery anatomy. The data shows that the asymptomatic and clinically stable adult ASO patient has a low pre-test probability for inducible ischemia. In this situation it is likely that routine evaluation with stress CMR is unnecessary.
PMCID: PMC4263214  PMID: 25497205
Transposition of the great vessels; Cardiovascular magnetic resonance; Nuclear cardiology; Ischemia
7.  Adenosine stress myocardial perfusion scintigraphy in pediatric patients after arterial switch operation 
Arterial switch operation (ASO) has become the established treatment for correction of transposition of great arteries (TGA). Despite the immediate correction of abnormal hemodynamics, acute and delayed complications related to the coronaries may cause morbidity and mortality.
We evaluated the incidence of perfusion abnormalities and safety of adenosine by stress–rest myocardial perfusion single-photon emission computed tomography (SPECT) [myocardial perfusion scintigraphy (MPS)] using Tc-99m Sestamibi (MIBI) in asymptomatic children post-ASO.
Settings and Design:
Prospective study.
Materials and Methods:
We conducted a prospective, single-institutional study where stress–rest MPS was performed on 10 children of age between 1.25 and 6 years. Two of the patients had additional ventricular septal defect, one patient had left ventricular outflow tract obstruction, and another had Taussig–Bing anomaly. All the patients underwent corrective surgery as a single-stage procedure at the age of 176 ± 212 days (range 9-560 days). Adenosine was administered at a rate of 140 μg/kg/min intravenously as continuous infusion for duration of 6 min.
Statistical Analysis Used:
All the continuous variables were summarized as mean ± standard deviation, or range and median. Mann–Whitney test for unpaired data and Wilcoxon Rank test for paired samples were used.
The average increase in heart rate over the basal heart rate after adenosine stress was 59.7 ± 17.0%. No acute or remote complications were observed in any case. None of the patients demonstrated myocardial perfusion defects, either at rest or after adenosine stress.
MPS post-adenosine induced vasodilatation is safe and feasible in patients of ASO for transposition of great arteries. One-stage repair, implantation of excised coronary buttons within neo-aortic sinus, and minimal or no mobilization of proximal coronaries may eliminate the occurrence of perfusion defects in patients of corrected TGA.
PMCID: PMC3866665  PMID: 24379530
Adenosine; arterial switch; myocardial perfusion scintigraphy; pediatric
8.  Impact of chylothorax on the early post operative outcome after pediatric cardiovascular surgery 
Background and aim
Chylothorax is the accumulation of chyle in the pleural cavity, which usually develops after disruption of the thoracic duct along its intra-thoracic route. In the majority of cases, this rupture is secondary to trauma (including cardio thoracic surgeries). Chylothorax is a potentially serious complication after cardiovascular surgeries that require early diagnosis and adequate management. This study aims to determine the risk factors and the impact of chylothorax on the early postoperative course after pediatric cardiac surgery.
A retrospective study of all cases complicated with chylothorax after pediatric cardiac surgery was conducted at King Abdulaziz Cardiac Center between January 2007 and December 2009.
There were 1135 cases operated on during the study period. Of these, 57 cases (5%) were complicated by chylothorax in the postoperative period. Thirty patients (54%) were males, while 27 (47%) were females. Ages ranged from 4 to 2759 days. The most common surgeries complicated by chylothorax were the single ventricle repair surgeries (15 cases, 27%); arch repairs (10 cases, 18%); ventricular septal defect repairs (10 cases, 18%); atrioventricular septal defect repairs (7 cases, 12%); arterial switch repair (6 cases, 11%), and others (8 cases, 14%). The intensive care unit (ICU) and the length of hospital stays were significantly longer in the chylothorax group. Additionally, some early postoperative parameters such as incidence of sepsis, ventilation time, and inotropes duration and number were higher in the chylothorax group.
Chylothorax after pediatric cardiac surgery is not a rare complication. It occurs more commonly with single ventricle repair and aortic arch repair surgeries, and has a significant impact on the postoperative course and post operative morbidity.
PMCID: PMC3978859  PMID: 24719538
Chylothorax; Post operative; Pediatric; Cardiac surgery
9.  An empirically based tool for analyzing morbidity associated with operations for congenital heart disease 
The Journal of thoracic and cardiovascular surgery  2012;145(4):10.1016/j.jtcvs.2012.06.029.
Congenital heart surgery outcomes analysis requires reliable methods of estimating the risk of adverse outcomes. Contemporary methods focus primarily on mortality or rely on expert opinion to estimate morbidity associated with different procedures. We created an objective, empirically based index that reflects statistically estimated risk of morbidity by procedure.
Morbidity risk was estimated using data from 62,851 operations in the Society of Thoracic Surgeons Congenital Heart Surgery Database (2002-2008). Model-based estimates with 95% Bayesian credible intervals were calculated for each procedure’s average risk of major complications and average postoperative length of stay. These 2 measures were combined into a composite morbidity score. A total of 140 procedures were assigned scores ranging from 0.1 to 5.0 and sorted into 5 relatively homogeneous categories.
Model-estimated risk of major complications ranged from 1.0% for simple procedures to 38.2% for truncus arteriosus with interrupted aortic arch repair. Procedure-specific estimates of average postoperative length of stay ranged from 2.9 days for simple procedures to 42.6 days for a combined atrial switch and Rastelli operation. Spearman rank correlation between raw rates of major complication and average postoperative length of stay was 0.82 in procedures with n greater than 200. Rate of major complications ranged from 3.2% in category 1 to 30.0% in category 5. Aggregate average postoperative length of stay ranged from 6.3 days in category 1 to 34.0 days in category 5.
Complication rates and postoperative length of stay provide related but not redundant information about morbidity. The Morbidity Scores and Categories provide an objective assessment of risk associated with operations for congenital heart disease, which should facilitate comparison of outcomes across cohorts with differing case mixes.
PMCID: PMC3824389  PMID: 22835225
10.  Postextubation dysphagia is persistent and associated with poor outcomes in survivors of critical illness 
Critical Care  2011;15(5):R231.
Dysphagia is common among survivors of critical illness who required mechanical ventilation during treatment. The risk factors associated with the development of postextubation dysphagia, and the effects of dysphagia on patient outcomes, have been relatively unexplored.
We conducted a retrospective, observational cohort study from 2008 to 2010 of all patients over 17 years of age admitted to a university hospital ICU who required mechanical ventilation and subsequently received a bedside swallow evaluation (BSE) by a speech pathologist.
A BSE was performed after mechanical ventilation in 25% (630 of 2,484) of all patients. After we excluded patients with stroke and/or neuromuscular disease, our study sample size was 446 patients. We found that dysphagia was present in 84% of patients (n = 374) and classified dysphagia as absent, mild, moderate or severe in 16% (n = 72), 44% (n = 195), 23% (n = 103) and 17% (n = 76), respectively. In univariate analyses, we found that statistically significant risk factors for severe dysphagia included long duration of mechanical ventilation and reintubation. In multivariate analysis, after adjusting for age, gender and severity of illness, we found that mechanical ventilation for more than seven days remained independently associated with moderate or severe dysphagia (adjusted odds ratio (AOR) = 2.84 [interquartile range (IQR) = 1.78 to 4.56]; P < 0.01). The presence of severe postextubation dysphagia was significantly associated with poor patient outcomes, including pneumonia, reintubation, in-hospital mortality, hospital length of stay, discharge status and surgical placement of feeding tubes. In multivariate analysis, we found that the presence of moderate or severe dysphagia was independently associated with the composite outcome of pneumonia, reintubation and death (AOR = 3.31 [IQR = 1.89 to 5.90]; P < 0.01).
In a large cohort of critically ill patients, long duration of mechanical ventilation was independently associated with postextubation dysphagia, and the development of postextubation dysphagia was independently associated with poor patient outcomes.
PMCID: PMC3334778  PMID: 21958475
11.  Aortic arch shape is not associated with hypertensive response to exercise in patients with repaired congenital heart diseases 
Aortic arch geometry is linked to abnormal blood pressure (BP) response to maximum exercise. This study aims to quantitatively assess whether aortic arch geometry plays a role in blood pressure (BP) response to exercise.
60 age- and BSA-matched subjects – 20 post-aortic coarctation (CoA) repair, 20 transposition of great arteries post arterial switch operation (ASO) and 20 healthy controls – had a three-dimensional (3D), whole heart magnetic resonance angiography (MRA) at 1.5 Tesla, 3D geometric reconstructions created from the MRA. All subjects underwent cardiopulmonary exercise test on the same day as MRA using an ergometer cycle with manual BP measurements. Geometric analysis and their correlation with BP at peak exercise were assessed.
Arch curvature was similarly acute in both the post-CoA and ASO cases [0.05 ± 0.01 vs. 0.05 ± 0.01 (1/mm/m2); p = 1.0] and significantly different to that of normal healthy controls [0.05 ± 0.01 vs. 0.03 ± 0.01 (1/mm/m2), p < 0.001]. Indexed transverse arch cross sectional area were significantly abnormal in the post-CoA cases compared to the ASO cases (117.8 ± 47.7 vs. 221.3 ± 44.6; p < 0.001) and controls (117.8 ± 47.7 vs. 157.5 ± 27.2 mm2; p = 0.003). BP response to peak exercise did not correlate with arch curvature (r = 0.203, p = 0.120), but showed inverse correlation with indexed minimum cross sectional area of transverse arch and isthmus (r = -0.364, p = 0.004), and ratios of minimum arch area/ descending diameter (r = -0.491, p < 0.001).
Transverse arch and isthmus hypoplasia, rather than acute arch angulation plays a role in the pathophysiology of BP response to peak exercise following CoA repair.
PMCID: PMC3833644  PMID: 24219806
Coarctation; Arterial switch operation; Anatomical models; Blood pressure; Exercise test
12.  Changing Expectations for Neurological Outcomes After the Neonatal Arterial Switch Operation 
The Annals of thoracic surgery  2012;94(4):1250-1256.
Expectations for outcomes after the neonatal arterial switch operation (ASO) continue to change. This cohort study describes neurodevelopmental outcomes at age 12 months after neonatal ASO, and analyzes both modifiable, and non-modifiable factors for association with adverse outcomes.
ASO patients (n=30) were enrolled in a prospective outcome study, with comprehensive clinical data collection over the first 12 months of life. Brain magnetic resonance imaging (MRI) was done preoperatively and 7 days postoperatively, Bayley Scales of Infant Development III was performed at age 12 months.
Ten of 30 patients (33%) had preoperative MRI injury; 13 of 30 (43%) had new postoperative MRI injury. 20 (67%) patients had Bayley Scales of Infant Development III: Cognitive score mean was 104.8 ± 15.0, Language score median was 90.0 (25th–75th percentile 83–94), and Motor score mean was 92.3 ± 14.2. Best subsets multivariable analysis found associations between lower preoperative and intraoperative cerebral oxygen saturation, preoperative MRI brain injury, total bypass time, and total midazolam dose and lower Bayley Scales of Infant Development III scores at age 12 months.
At 12 months after ASO, neurodevelopmental outcome means were within normal population ranges. The new associations reported in this study between potentially modifiable perioperative factors and outcomes require investigations in larger patient cohorts. Beyond survival, which was 100% in this cohort, factors influencing quality of life including neurodevelopmental outcomes, should be routinely investigated in studies of ASO patients.
PMCID: PMC3586524  PMID: 22748448
Anesthesia; brain; cardiopulmonary bypass (CPB); CHD; arterial switch operation; neurocognitive deficits
13.  Transcatheter closure of atrial septal defects in adults with the Amplatzer septal occluder 
Heart  1999;82(5):559-562.
OBJECTIVE—To assess the efficacy and complications of device occlusion of atrial septal defects in adults, using the Amplatzer septal occluder (ASO).
DESIGN—A prospective interventional study.
SETTING—Paediatric cardiology departments in two European teaching hospitals.
PATIENTS—The first 20 patients accepted for atrial septal defect device occlusion, on the basis of transoesophageal echocardiography. Sixteen patients had larger defects with right heart dilatation, while the primary indication for closure in four was a history of early paradoxical embolism.
INTERVENTIONS—Transcatheter atrial septal defect occlusions performed under transoesophageal echocardiography and fluoroscopic guidance between December 1996 and June 1998.
OUTCOME MEASURES—Success of deployment of ASO devices, procedure and fluoroscopic times, complications, and symptoms.
RESULTS—The ASO device was successfully implanted in all 20 patients (14 female), median age 44.2 years, with no complications. Of the 16 patients with right heart dilatation, the median Qp:Qs was 2.5:1. Defects measured 11-22 mm (median 18) on transoesophageal echocardiography, with balloon sized diameter (and device size) of 13-28 mm (median 20). For all 20 patients, the procedure time ranged from 38-78 minutes (median 61), and fluoroscopy 8.4-24.7 minutes (median 15.2). There were residual shunts in three patients at the end of the procedure, which were trivial (⩽ 1 mm) as assessed by transoesophageal echocardiography, and persisted for more than six months in only one patient. Follow up ranged from 0.1-1.5 years (median 0.7). There have been no late complications.
CONCLUSIONS—The ASO device can be used successfully to close selected oval fossa defects in adults, with minimal procedural morbidity and excellent early results.

Keywords: atrial septal defect; interventional cardiac catheterisation; Amplatzer septal occluder
PMCID: PMC1760778  PMID: 10525508
14.  Resource Utilization After Introduction of a Standardized Clinical Assessment and Management Plan 
Congenital Heart Disease  2010;5(4):374-381.
A Standardized Clinical Assessment and Management Plan (SCAMP) is a novel quality improvement initiative that standardizes the assessment and management of all patients who carry a predefined diagnosis. Based on periodic review of systemically collected data the SCAMP is designed to be modified to improve its own algorithm. One of the objectives of a SCAMP is to identify and reduce resource utilization and patient care costs.
We retrospectively reviewed resource utilization in the first 93 arterial switch operation (ASO) SCAMP patients and 186 age-matched control ASO patients. We compared diagnostic and laboratory testing obtained at the initial SCAMP clinic visit and control patient visits. To evaluate the effect of the SCAMP over time, the number of clinic visits per patient year and echocardiograms per patient year in historical control ASO patients were compared to the projected rates for ASO SCAMP participants.
Cardiac magnetic resonance imaging (MRI), stress echocardiogram, and lipid profile utilization were higher in the initial SCAMP clinic visit group than in age-matched control patients. Total echocardiogram and lung scan usage were similar. Chest X-ray and exercise stress testing were obtained less in SCAMP patients. ASO SCAMP patients are projected to have 0.5 clinic visits and 0.5 echocardiograms per year. Historical control patients had more clinic visits (1.2 vs. 0.5 visits/patient year, P < .01) and a higher echocardiogram rate (0.92 vs. 0.5 echocardiograms/patient year, P <.01)
Implementation of a SCAMP may initially lead to increased resource utilization, but over time resource utilization is projected to decrease.
PMCID: PMC3376534  PMID: 20653704
Congenital Heart Disease; Tests; Practice Guidelines; Resource Utilization; Health Policy and Outcomes
15.  The Effect of Diabetes Mellitus on Short Term Mortality and Morbidity after Isolated Coronary Artery Bypass Grafting Surgery 
This study was conducted to determine whether Diabetes Mellitus (DM) is a predictor of short term mortality ; morbidity, or early readmission to hospital after Coronary Artery Bypass Graft (CABG).
We analyzed a large cohort of 952 patients who had undergone isolated CABG. The preoperative, intera operative and postoperative risk factors as well as the complications and 30-day mortality rates were compared between the diabetics and non-diabetics. Among the 952 patients; 734 ones (77.1%) were in non-diabetic group and 218 (22.9%) were diabetics.
Having DM did not increase the risk of 30-day mortality. In addition, DM did not affect the major complications; arrhythmia, Myocardial Infarction(MI), infective complications, neurological complications, Pulmonary Embolism (PE) except renal complications that was higher in the diabetics (5.5% vs 1.4%; P<0.001, OR=4.2) However reoperation for bleeding was higher in non-diabetic patients (7.9% vs 4.6%; P=0.009, OR=1.7). Nevertheless ,no significant difference was observed between the two groups regarding mechanical ventilation time (hour), reintubation, length of ICU stay (day), length of hospital stay (day), and readmitting as postoperative variables.
Except for renal complications, DM was not associated with adverse outcomes in the patients undergoing isolated CABG.
PMCID: PMC3987431  PMID: 24757619
Diabetes; Postoperative Complications; Coronary Artery Bypass Graft; Morbidity; Mortality
16.  Endovascular Repair of Descending Thoracic Aortic Aneurysm 
Executive Summary
To conduct an assessment on endovascular repair of descending thoracic aortic aneurysm (TAA).
Clinical Need
Aneurysm is the most common condition of the thoracic aorta requiring surgery. Aortic aneurysm is defined as a localized dilatation of the aorta. Most aneurysms of the thoracic aorta are asymptomatic and incidentally discovered. However, TAA tends to enlarge progressively and compress surrounding structures causing symptoms such as chest or back pain, dysphagia (difficulty swallowing), dyspnea (shortness of breath), cough, stridor (a harsh, high-pitched breath sound), and hoarseness. Significant aortic regurgitation causes symptoms of congestive heart failure. Embolization of the thrombus to the distal arterial circulation may occur and cause related symptoms. The aneurysm may eventually rupture and create a life-threatening condition.
The overall incidence rate of TAA is about 10 per 100,000 person-years. The descending aorta is involved in about 30% to 40% of these cases.
The prognosis of large untreated TAAs is poor, with a 3-year survival rate as low as 25%. Intervention is strongly recommended for any symptomatic TAA or any TAA that exceeds twice the diameter of a normal aorta or is 6 cm or larger. Open surgical treatment of TAA involves left thoracotomy and aortic graft replacement. Surgical treatment has been found to improve survival when compared with medical therapy. However, despite dramatic advances in surgical techniques for performing such complex operations, operative mortality from centres of excellence are between 8% and 20% for elective cases, and up to 50% in patients requiring emergency operations. In addition, survivors of open surgical repair of TAAs may suffer from severe complications. Postoperative or postprocedural complications of descending TAA repair include paraplegia, myocardial infarction, stroke, respiratory failure, renal failure, and intestinal ischemia.
The Technology
Endovascular aortic aneurysm repair (EVAR) using a stent graft, a procedure called endovascular stent-graft (ESG) placement, is a new alternative to the traditional surgical approach. It is less invasive, and initial results from several studies suggest that it may reduce mortality and morbidity associated with the repair of descending TAAs.
The goal in endovascular repair is to exclude the aneurysm from the systemic circulation and prevent it from rupturing, which is life-threatening. The endovascular placement of a stent graft eliminates the systemic pressure acting on the weakened wall of the aneurysm that may lead to the rupture. However, ESG placement has some specific complications, including endovascular leak (endoleak), graft migration, stent fracture, and mechanical damage to the access artery and aortic wall.
The Talent stent graft (manufactured by Medtronic Inc., Minneapolis, MN) is licensed in Canada for the treatment of patients with TAA (Class 4; licence 36552). The design of this device has evolved since its clinical introduction. The current version has a more flexible delivery catheter than did the original system. The prosthesis is composed of nitinol stents between thin layers of polyester graft material. Each stent is secured with oversewn sutures to prevent migration.
Review Strategy
To compare the effectiveness and cost-effectiveness of ESG placement in the treatment of TAAs with a conventional surgical approach
To summarize the safety profile and effectiveness of ESG placement in the treatment of descending TAAs
Measures of Effectiveness
Primary Outcome
Mortality rates (30-day and longer term)
Secondary Outcomes
Technical success rate of introducing a stent graft and exclusion of the aneurysm sac from systemic circulation
Rate of reintervention (through surgical or endovascular approach)
Measures of Safety
Complications were categorized into 2 classes:
Those specific to the ESG procedure, including rates of aneurysm rupture, endoleak, graft migration, stent fracture, and kinking; and
Those due to the intervention, either surgical or endovascular. These include paraplegia, stroke, cardiovascular events, respiratory failure, real insufficiency, and intestinal ischemia.
Inclusion Criteria
Studies comparing the clinical outcomes of ESG treatment with surgical approaches
Studies reporting on the safety and effectiveness of the ESG procedure for the treatment of descending TAAs
Exclusion Criteria
Studies investigating the clinical effectiveness of ESG placement for other conditions such as aortic dissection, aortic ulcer, and traumatic injuries of the thoracic aorta
Studies investigating the aneurysms of the ascending and the arch of the aorta
Studies using custom-made grafts
Literature Search
The Medical Advisory Secretariat searched The International Network of Agencies for Health Technology Assessment and the Cochrane Database of Systematic Reviews for health technology assessments. It also searched MEDLINE, EMBASE, Medline In-Process & Other Non-Indexed Citations, and Cochrane CENTRAL from January 1, 2000 to July 11, 2005 for studies on ESG procedures. The search was limited to English-language articles and human studies.
One health technology assessment from the United Kingdom was identified. This systematic review included all pathologies of the thoracic aorta; therefore, it did not match the inclusion criteria. The search yielded 435 citations; of these, 9 studies met inclusion criteria.
Summary of Findings
The results of a comparative study found that in-hospital mortality was not significantly different between ESG placement and surgery patients (2 [4.8%] for ESG vs. 6 [11.3%] for surgery).
Pooled data from case series with a mean follow-up ranging from 12 to 38 months showed a 30-day mortality and late mortality rate of 3.9% and 5.5%, respectively. These rates are lower than are those reported in the literature for surgical repair of TAA.
Case series showed that the most common cause of early death in patients undergoing endovascular repair is aortic rupture, and the most common causes of late death are cardiac events and aortoesophageal or aortobronchial fistula.
Technical Success Rate
Technical success rates reported by case series are 55% to 100% (100% and 94.4% in 2 studies with all elective cases, 89% in a study with 5% emergent cases, and 55% in a study with 42% emergent cases).
Surgical Reintervention
In the comparative study, 3 (7.1%) patients in the ESG group and 14 (26.5%) patients in the surgery group required surgical reintervention. In the ESG group, the reasons for surgical intervention were postoperative bleeding at the access site, paraplegia, and type 1 endoleak. In the surgical group, the reasons for surgery were duodenal perforation, persistent thoracic duct leakage, false aneurysm, and 11 cases of postoperative bleeding.
Pooled data from case series show that 9 (2.6%) patients required surgical intervention. The reasons for surgical intervention were endoleak (3 cases), aneurysm enlargement and suspected infection (1 case), aortic dissection (1 case), pseudoaneurysm of common femoral artery (1 case), evacuation of hematoma (1 case), graft migration (1 case), and injury to the access site (1 case).
Endovascular Revision
In the comparative study, 3 (7.1%) patients required endovascular revision due to persistent endoleak.
Pooled data from case series show that 19 (5.3%) patients required endovascular revision due to persistent endoleak.
Graft Migration
Two case series reported graft migration. In one study, 3 proximal and 4 component migrations were noted at 2-year follow-up (total of 5%). Another study reported 1 (3.7%) case of graft migration. Overall, the incidence of graft migration was 2.6%.
Aortic Rupture
In the comparative study, aortic rupture due to bare stent occurred in 1 case (2%). The pooled incidence of aortic rupture or dissection reported by case series was 1.4%.
Postprocedural Complications
In the comparative study, there were no statistically significant differences between the ESG and surgery groups in postprocedural complications, except for pneumonia. The rate of pneumonia was 9% for those who received an ESG and 28% for those who had surgery (P = .02). There were no cases of paraplegia in either group. The rate of other complications for ESG and surgery including stroke, cardiac, respiratory, and intestinal ischemia were all 5.1% for ESG placement and 10% for surgery. The rate for mild renal failure was 16% in the ESG group and 30% in the surgery group. The rate for severe renal failure was 11% for ESG placement and 10% for surgery.
Pooled data from case series show the following postprocedural complication rates in the ESG placement group: paraplegia (2.2%), stroke (3.9%), cardiac (2.9%), respiratory (8.7%), renal failure (2.8%), and intestinal ischemia (1%).
Time-Related Outcomes
The results of the comparative study show statistically significant differences between the ESG and surgery group for mean operative time (ESG, 2.7 hours; surgery, 5 hours), mean duration of intensive care unit stay (ESG, 11 days; surgery, 14 days), and mean length of hospital stay (ESG, 10 days; surgery, 30 days).
The mean duration of intensive care unit stay and hospital stay derived from case series is 1.6 and 7.8 days, respectively.
Ontario-Based Economic Analysis
In Ontario, the annual treatment figures for fiscal year 2004 include 17 cases of descending TAA repair procedures (source: Provincial Health Planning Database). Fourteen of these have been identified as “not ruptured” with a mean hospital length of stay of 9.23 days, and 3 cases have been identified as “ruptured,” with a mean hospital length of stay of 28 days. However, because one Canadian Classification of Health Interventions code was used for both procedures, it is not possible to determine how many were repaired with an EVAR procedure or with an open surgical procedure.
Hospitalization Costs
The current fiscal year forecast of in-hospital direct treatment costs for all in-province procedures of repair of descending TAAs is about $560,000 (Cdn). The forecast in-hospital total cost per year for in-province procedures is about $720,000 (Cdn). These costs include the device cost when the procedure is EVAR (source: Ontario Case Costing Initiative).
Professional (Ontario Health Insurance Plan) Costs
Professional costs per treated patient were calculated and include 2 preoperative thoracic surgery or EVAR consultations.
The professional costs of an EVAR include the fees paid to the surgeons, anesthetist, and surgical assistant (source: fee service codes). The procedure was calculated to take about 150 minutes.
The professional costs of an open surgical repair include the fees of the surgeon, anesthetist, and surgical assistant. Open surgical repair was estimated to take about 300 minutes.
Services provided by professionals in intensive care units were also taken into consideration, as were the costs of 2 postoperative consultations that the patients receive on average once they are discharged from the hospital. Therefore, total Ontario Health Insurance Plan costs per treated patient treated with EVAR are on average $2,956 (ruptured or not ruptured), as opposed to $5,824 for open surgical repair and $6,157 for open surgical repair when the aneurysm is ruptured.
Endovascular stent graft placement is a less invasive procedure for repair of TAA than is open surgical repair.
There is no high-quality evidence with long-term follow-up data to support the use of EVAR as the first choice of treatment for patients with TAA that are suitable candidates for surgical intervention.
However, short- and medium-term outcomes of ESG placement reported by several studies are satisfactory and comparable to surgical intervention; therefore, for patients at high risk of surgery, it is a practical option to consider. Short- and medium-term results show that the benefit of ESG placement over the surgical approach is a lower 30-day mortality and paraplegia rate; and shorter operative time, ICU stay, and hospital stay.
PMCID: PMC3382300  PMID: 23074469
17.  Efficacy of thoracic endovascular stent repair for chronic type B aortic dissection with aneurysmal degeneration 
Journal of vascular surgery  2013;58(1):10-7.e1.
The Food and Drug Administration has approved devices for endovascular management of thoracic endovascular aortic aneurysm repair (TEVAR); however, limited data exist describing the outcomes of TEVAR for aneurysms attributable to chronic type B aortic dissection (cTBAD). This study was undertaken to determine the results of endovascular treatment of cTBAD with aneurysmal degeneration.
A retrospective analysis of all patients treated for cTBAD with aneurysmal degeneration at the University of Florida from 2004 to 2011 was performed. Computed tomograms with centerline reconstruction were analyzed to determine change in aortic diameter, relative proportions of aortic treatment lengths, and false lumen perfusion status. Reintervention and mortality were estimated using life-tables. Cox regression analysis was completed to predict mortality.
Eighty patients underwent TEVAR for aneurysm due to cTBAD (mean age [± standard deviation], 60 ± 13 years [male, 87.5%; n = 70]; median follow-up, 26 [range, 1–74] months). Median time from diagnosis of TBAD to TEVAR was 16 (range, 1–72) months. Prior aortic root/arch replacement had been performed in 29% (n = 23) at a median interval of 28.5 (range, 0.5–312) months. Mean preoperative aneurysm diameter was 62.0 ± 9.9 mm. In 75% (n = 60) of cases, coverage was proximal to zone 3, and 24% (n = 19) underwent carotid-subclavian bypass or other arch debranching procedure. Spinal drains were used in 78% (pre-op 71%, n = 57; post-op 6%, n = 5). Length of stay was 6.5 ± 4.7 days with a composite morbidity of 26% and in-hospital mortality of 2.5% (n = 2). Overall neurologic event rate was 17% (spinal cord ischemia 10% [n = 8], with a permanent deficit observed in 6.2% [n = 5]; stroke 7.5%). Aneurysm diameter reduced or stabilized in 65%. The false lumen thrombosed completely within the thoracic aorta in 52%, and reintervention within the treated aortic segment was required in 16% (n = 13). One- and 3-year freedom from reintervention (with 95% confidence interval [CI]) was 80% (range, 68%–88%) and 70% (range, 57%–80%), respectively. Survival at 1 and 5 years was 89% (range, 80%–94%) and 70% (range, 55%–81%) and was not significantly different among patients requiring reintervention or experiencing favorable aortic remodeling. Multivariable analysis identified coronary artery disease (hazard ratio [HR], 6.4; 95% CI, 2.3–17.7; P < .005), prior infrarenal aortic surgery (HR, 8.6; 95% CI, 2.3–31.7; P = .001), and congestive heart failure (HR, 11.9; 95% CI, 1.9–73.8; P = .008) as independent risk factors for mortality. Hyperlipidemia was found to be protective (HR, 0.2; 95% CI, 0.05–0.6; P = .004). No significant difference in predictors of mortality were found between patients who underwent reintervention vs those who did not (P = .2).
TEVAR for cTBAD with aneurysmal degeneration can be performed safely but spinal cord ischemia rates may be higher than previously reported. Liberal use of procedural adjuncts to reduce this complication, such as spinal drainage, is recommended. Reintervention is common, but long-term survival does not appear to be impacted by remediation.
PMCID: PMC4170732  PMID: 23561433
18.  Right ventricular hypertrophy and diastolic dysfunction in arterial switch patients without pulmonary artery stenosis 
Heart  2007;93(12):1604-1608.
To assess pulmonary flow dynamics and right ventricular (RV) function in patients without significant anatomical narrowing of the pulmonary arteries late after the arterial switch operation (ASO) by using magnetic resonance imaging (MRI).
17 patients (mean (SD), 16.5 (3.6) years after ASO) and 17 matched healthy subjects were included. MRI was used to assess flow across the pulmonary trunk, RV systolic and diastolic function, and RV mass.
Increased peak flow velocity (>1.5 m/s) was found across the pulmonary trunk in 14 of 17 patients. Increased RV mass was found in ASO patients: 14.9 (3.4) vs 10.0 (2.6) g/m2 in normal subjects (p<0.01). Delayed RV relaxation was found after ASO: mean tricuspid valve E/A peak flow velocity ratio = 1.60 (0.96) vs 1.92 (0.61) in normal subjects (p = 0.03), and E‐deceleration gradients = −1.69 (0.73) vs −2.66 (0.96) (p<0.01). After ASO, RV mass correlated with pulmonary trunk peak flow velocity (r = 0.49, p<0.01) and tricuspid valve E‐deceleration gradients (r = 0.35, p = 0.04). RV systolic function was well preserved in patients (ejection fraction = 53 (7)% vs 52 (8)% in normal subjects, p = 0.72).
Increased peak flow velocity in the pulmonary trunk was often observed late after ASO, even in the absence of significant pulmonary artery stenosis. Haemodynamic consequences were RV hypertrophy and RV relaxation abnormalities as early markers of disease, while systolic RV function was well preserved.
PMCID: PMC2095768  PMID: 17277348
arterial switch operation; pulmonary artery; right ventricle; magnetic resonance imaging; congenital heart disease
19.  Desflurane Versus Opioid Anesthesia for Cardiac Shunt Procedures in Infants With Cyantoic Congential Heart Disease 
Anesthesiology and Pain Medicine  2013;3(1):191-197.
Placement of a Blalock-Taussig (BT) shunt is frequently performed for palliation of cyanotic congenital heart disease (CCHD).
Inhalational anesthetics, when used in adult heart surgery, offer advantages of myocardial protection and decrease in use of inotropes, duration of ventilation, ICU and hospital length of stay (LOS).There is little literature, however, in the comparative use of inhalational and narcotic anesthesia in CCHD.
Patients and Methods
Following Institutional Ethical Review Board approval and parental consent, 35 patients presenting for BT shunt were prospectively randomized to receive either a desflurane anesthetic or a narcotic anesthetic. Institutional practice for all patients undergoing BT shunt is to undergo cardiopulmonary bypass (CPB) following median sternotomy. Induction was accomplished with 5-7% sevoflurane in 100% oxygen, 2ug/kg fentanyl, 0.05mg/kg midazolam and 0.1mg/kg vecuronium. After intubation, patients in the narcotic group (n=16) received an additional 5-10ug/kg fentanyl, 0.1mg/kg midazolam, 100% oxygen and vecuronium. Patients in the inhalational group (n=19) received desflurane, 0.6-1 MAC, 100% oxygen, 0.05mg/kg midazolam, IV paracetamol 15mg/kg and vecuronium. At the end of surgery, patients were transferred to the ICU and received IV paracetamol and midazolam. Ventilation was weaned when the patient was hemodynamically stable. Demographics, baseline, intra and post-op heart rates, duration of inotrope use, ICU and hospital LOS, pre and post-op creatinine and serious adverse events (SAE) were recorded. Data were analyzed using Student, paired t, Mann-Whitney U and Chi square/Fisher exact tests, P < 0.05 significant.
Demographic data were similar, except for a modestly higher pre-op heart rate in the group receiving opioid anesthesia. Patients receiving desflurane had a significantly shorter duration of mechanical ventilation and length of ICU and hospital stay. Inotrope use was similar in both groups. The group receiving opioid anesthesia had an increase in creatinine post operatively which was not observed in the desflurane group. There was no difference in incidence of significant adverse events in either group.
Use of inhalational anesthesia has increased in adult cardiac surgery and has proved to reduce duration of elective ventilation, decrease ICU and hospital LOS, and mortality. Inhalational anesthetics are less well-studied in CCHD. In the current study, desflurane was chosen because of its low solubility, decreased recovery time and lack of metabolism or organ system toxicities. Although it is a popular belief that desflurane is associated with tachycardia and airway irritation, findings of the current study are consistent with those of the previous works demonstrating a lack of these side effects below 1 MAC3. No hemodynamic instability was encountered and there was no evidence that desflurane exerted a negative inotropic effect. Markers of cardio protection were not examined, although desflurane may have had a renal protective effect compared to narcotic technique. In the current study, a desflurane anesthetic for BT shunt decreased the duration of mechanical ventilation and ICU and hospital LOS by nearly three days, with no difference in perioperative morbidity or mortality. Larger studies are required to determine whether these changes result in overall decreased complication rate and morbidity/mortality and whether desflurane has a cardio or renal protective effect in the patient population.
PMCID: PMC3821147  PMID: 24223361
Research; Humans; Anesthesia; Heart Diseases; Desflurane; Analgesics, Opioid
20.  Outcome of low body weight (<2.2 kg) infants undergoing cardiac surgery 
Infants with low body weight (LBW) following cardiac surgery are a major challenge for the post cardiac surgery care unit. It has been observed that post surgery outcome for LBW infants is worse compared to the outcome of normal body weight infants. A study was conducted to compare post operative course and outcome of infants with body weight of 2.2 kg or less against infants with normal body weight who underwent similar cardiac surgeries.
A retrospective review was performed for all infants below 2.2 kg who underwent cardiac operations at King Abdulaziz Cardiac Center from January 2001 to October 2011. Cases with LBW (Group A) were compared with matching group (Group B) of normal body weight infants who had similar cardiac surgeries and matching surgical risk category. The demographic, ICU parameters, complications, and short-term outcome of both groups were analyzed.
Two groups were formed, with 37 patients in Group A, and 39 patients in Group B. Except for weight (2.13 ± 0.08 kg in Group A vs 3.17 ± 0.2 kg in Group B), there was no statistical difference in demographic data between both groups. Cardiac procedures included coarctation repair, arterial switch, ventricular septal defect (VSD) repair, tetralogy of Fallot repair, systemic to pulmonary shunt and Norwood procedures. Patients in Group A had statistically significant difference from Group B in terms of bypass time (p = 0.01), duration of inotropes (p = 0.01), duration of mechanical ventilation (p = 0.004), number of re-intubations (p = 0.015), PCICU length of stay (p = 0.007), and hospital mortality: 13.5% in Group A vs 0% in Group B (p value 0.02).
Patients with LBW (<2.2 kg) underwent cardiac surgery with overall satisfactory results, but with increased risk of ICU morbidity and mortality.
PMCID: PMC4062764  PMID: 24954985
Post operative; Pediatric; Cardiac surgery; Low body weight
21.  Risk Factors for Ventilator Dependency Following Coronary Artery Bypass Grafting 
Background: Ventilator dependency following coronary artery bypass grafting (CABG) is often associated with significant morbidity and mortality. However, few reports have focused on the independent risk factors for ventilator dependency following CABG. This study aimed to evaluate the independent risk factors for ventilator dependency following coronary artery bypass grafting (CABG). Methods: The relevant pre-, intra- and post-operative data of patients without a history of chronic obstructive pulmonary disease undergoing isolated CABG from January 2003 to December 2008 in our center were retrospectively analyzed. Elapsed time between CABG and extubation of more than 48 hours was defined as postoperative ventilator dependency (PVD). Results: The incidence of PVD was 13.8% (81/588). The in-hospital mortality in the PVD group was significantly higher than that in the non-PVD group (8.6% versus 2.4%, p=0.0092). Besides the length of ICU and hospital stay, PVD correlated with negative respiratory outcomes. The independent risk factors for PVD were preoperative congestive heart failure (OR=2.456, 95%CI 1.426-6.879), preoperative hypoalbuminemia (OR=1.353, 95%CI 1.125-3.232), preoperative arterial oxygen partial pressure (PO2) (OR=0.462, 95%CI 0.235-0.783) and postoperative anaemia (OR=1.541, 95%CI 1.231-3.783). Conclusions: Preoperative congestive heart failure, preoperative hypoalbuminemia, low preoperative PO2 and postoperative anaemia were identified as four independent risk factors for ventilator dependency following CABG.
PMCID: PMC3372937  PMID: 22701338
Coronary artery bypass grafting; ventilator dependency; risk factor.
22.  Endovascular Repair of Abdominal Aortic Aneurysm 
The Medical Advisory Secretariat conducted a systematic review of the evidence on the effectiveness and cost-effectiveness of endovascular repair of abdominal aortic aneurysm in comparison to open surgical repair. An abdominal aortic aneurysm [AAA] is the enlargement and weakening of the aorta (major blood artery) that may rupture and result in stroke and death. Endovascular abdominal aortic aneurysm repair [EVAR] is a procedure for repairing abdominal aortic aneurysms from within the blood vessel without open surgery. In this procedure, an aneurysm is excluded from blood circulation by an endograft (a device) delivered to the site of the aneurysm via a catheter inserted into an artery in the groin. The Medical Advisory Secretariat conducted a review of the evidence on the effectiveness and cost-effectiveness of this technology. The review included 44 eligible articles out of 489 citations identified through a systematic literature search. Most of the research evidence is based on non-randomized comparative studies and case series. In the short-term, EVAR appears to be safe and comparable to open surgical repair in terms of survival. It is associated with less severe hemodynamic changes, less blood transfusion and shorter stay in the intensive care and hospital. However, there is concern about a high incidence of endoleak, requiring secondary interventions, and in some cases, conversion to open surgical repair. Current evidence does not support the use of EVAR in all patients. EVAR might benefit individuals who are not fit for surgical repair of abdominal aortic aneurysm and whose risk of rupture of the aneurysm outweighs the risk of death from EVAR. The long-term effectiveness and cost-effectiveness of EVAR cannot be determined at this time. Further evaluation of this technology is required.
The objective of this health technology policy assessment was to determine the effectiveness and cost-effectiveness of endovascular repair of abdominal aortic aneurysms (EVAR) in comparison to open surgical repair (OSR).
Clinical Need
An abdominal aortic aneurysm (AAA) is a localized, abnormal dilatation of the aorta greater than 3 cm or 50% of the aortic diameter at the diaphragm. (1) A true AAA involves all 3 layers of the vessel wall. If left untreated, the continuing extension and thinning of the vessel wall may eventually result in rupture of the AAA. The risk of death from ruptured AAA is 80% to 90%. (61) Heller et al. (44) analyzed information from a national hospital database in the United States. They found no significant change in the incidence rate of elective AAA repair or ruptured AAA presented to the nation’s hospitals. The investigators concluded that technologic and treatment advances over the past 19 years have not affected the outcomes of patients with AAAs, and the ability to identify and to treat patients with AAAs has not improved.
Classification of Abdominal Aortic Aneurysms
At least 90% of the AAAs are affected by atherosclerosis, and most of these aneurysms are below the level of the renal arteries.(1)
An abdominal aortic aneurysm may be symptomatic or asymptomatic. An AAA may be classified according to their sizes:(7)
Small aneurysms: less than 5 cm in diameter.
Medium aneurysms: 5-7cm.
Large aneurysms: more than 7 cm in diameter.
Small aneurysms account for approximately 50% of all clinically recognized aneurysms.(7)
Aortic aneurysms may be classified according to their gross appearance as follows (1):
Fusiform aneurysms affect the entire circumference of a vessel, resulting in a diffusely dilated lesion
Saccular aneurysms involve only a portion of the circumference, resulting in an outpouching (protrusion) in the vessel wall.
Prevalence of Abdominal Aortic Aneurysms
In community surveys, the prevalence of AAA is reported to be between 1% and 5.4%. (61) The prevalence is related to age and vascular risk factors. It is more common in men and in those with a positive family history.
In Canada, Abdominal aortic aneurysms are the 10th leading cause of death in men 65 years of age or older. (60) Naylor (60) reported that the rate of AAA repair in Ontario has increased from 38 per 100,000 population in 1981/1982 to 54 per 100,000 population in 1991/1992. For the period of 1989/90 to 1991/92, the rate of AAA repair in Ontarians age 45 years and over was 53 per 100,000. (60) In the United States, about 200,000 new cases are diagnosed each year, and 50,000 to 60,000 surgical AAA repairs are performed. (2) Ruptured AAAs are responsible for about 15,000 deaths in the United States annually. One in 10 men older than 80 years has some aneurysmal change in his aorta. (2)
Symptoms of Abdominal Aortic Aneurysms
AAAs usually do not produce symptoms. However, as they expand, they may become painful. Compression or erosion of adjacent tissue by aneurysms also may cause symptoms. The formation of mural thrombi, a type of blood clots, within the aneurysm may predispose people to peripheral embolization, where blood vessels become blocked. Occasionally, an aneurysm may leak into the vessel wall and the periadventitial area, causing pain and local tenderness. More often, acute rupture occurs without any prior warning, causing acute pain and hypotension. This complication is always life-threatening and requires an emergency operation.
Diagnosis of Abdominal Aortic Aneurysms
An AAA is usually detected on routine examination as a palpable, pulsatile, and non-tender mass. (1)
Abdominal radiography may show the calcified outline of the aneurysms; however, about 25% of aneurysms are not calcified and cannot be visualized by plain x-ray. (1) An abdominal ultrasound provides more accurate detection, can delineate the traverse and longitudinal dimensions of the aneurysm, and is useful for serial documentation of aneurysm size. Computed tomography and magnetic resonance have also been used for follow-up of aortic aneurysms. These technologies, particularly contrast-enhanced computer tomography, provide higher resolution than ultrasound.
Abdominal aortography remains the gold standard to evaluate patients with aneurysms for surgery. This technique helps document the extent of the aneurysms, especially their upper and lower limits. It also helps show the extent of associated athereosclerotic vascular disease. However, the procedure carries a small risk of complications, such as bleeding, allergic reactions, and atheroembolism. (1)
Prognosis of Abdominal Aortic Aneurysms
The risk of rupture of an untreated AAA is a continuous function of aneurysm size as represented by the maximal diameter of the AAA. The annual rupture rate is near zero for aneurysms less than 4 cm in diameter. The risk is about 1% per year for aneurysms 4 to 4.9 cm, 11% per year for aneurysms 5 to 5.9 cm, and 25% per year or more for aneurysms greater than 6 cm. (7)
The 1-year mortality rate of patients with AAAs who do not undergo surgical treatment is about 25% if the aneurysms are 4 to 6 cm in diameter. This increases to 50% for aneurysms exceeding 6 cm. Other major causes of mortality for people with AAAs include coronary heart disease and stroke.
Treatment of Abdominal Aortic Aneurysms
Treatment of an aneurysm is indicated under any one of the following conditions:
The AAA is greater than 6 cm in diameter.
The patient is symptomatic.
The AAA is rapidly expanding irrespective of the absolute diameter.
Open surgical repair of AAA is still the gold standard. It is a major operation involving the excision of dilated area and placement of a sutured woven graft. The surgery may be performed under emergent situation following the rupture of an AAA, or it may be performed electively.
Elective OSR is generally considered appropriate for healthy patients with aneurysms 5 to 6 cm in diameter. (7) Coronary artery disease is the major underlying illness contributing to morbidity and mortality in OSR. Other medical comorbidities, such as chronic renal failure, chronic lung disease, and liver cirrhosis with portal hypertension, may double or triple the usual risk of OSR.
Serial noninvasive follow-up of small aneurysms (less than 5 cm) is an alternative to immediate surgery.
Endovascular repair of AAA is the third treatment option and is the topic of this review.
PMCID: PMC3387737  PMID: 23074438
23.  Association of gender with outcomes in critically ill patients 
Critical Care  2012;16(3):R92.
The influence of gender on mortality and other outcomes of critically ill patients is not clear. Different studies have been performed in various settings and patient populations often yielding conflicting results. We wanted to assess the relationship of gender and intensive care unit (ICU) outcomes in the patients included in the Acute Physiology and Chronic Health Evaluation (APACHE) IV database (Cerner Corporation, USA).
We performed a retrospective review of the data available in the APACHE IV database. A total of 261,255 consecutive patients admitted to adult ICUs in United States from 1 January 2004 to 31 December 2008 were included. Readmissions were excluded from the analysis. The primary objective of the study was to assess the relationship of gender with ICU mortality. The secondary objective was to evaluate the association of gender with active therapy, mechanical ventilation, length of stay in the ICU, readmission rate and hospital mortality. The gender-related outcomes for disease subgroups including acute coronary syndrome, coronary artery bypass graft (CABG) surgery, sepsis, trauma and chronic obstructive pulmonary disease (COPD) exacerbation were assessed as well.
ICU mortality was 7.2% for men and 7.9% for women, odds ratio (OR) for death for women was 1.07 (95% confidence interval (CI): 1.04 to 1.1). There was a statistically significant interaction between gender and age. In patients <50 years of age, women had a reduced ICU mortality compared with men, after adjustment for acute physiology score, ethnicity, co-morbid conditions, pre-ICU length of stay, pre-ICU location and hospital teaching status (adjusted OR 0.83, 95% CI: 0.76 to 0.91). But among patients ≥50 years of age, there was no significant difference in ICU mortality between men and women (adjusted OR 1.02, 95% CI: 0.98 to 1.06).
A higher proportion of men received mechanical ventilation, emergent surgery, thrombolytic therapy and CABG surgery. Men had a higher readmission rate and longer length of ICU stay. The adjusted mortality of women compared to men was higher with CABG, while it was lower with COPD exacerbation. There was no significant difference in mortality in acute coronary syndrome, sepsis and trauma.
Among the critically ill patients, women less than 50 years of age had a lower ICU mortality compared to men, while 50 years of age or older women did not have a significant difference compared to men. Women had a higher mortality compared to men after CABG surgery and lower mortality with COPD exacerbation. There was no difference in mortality in acute coronary syndrome, sepsis or trauma.
PMCID: PMC3580638  PMID: 22617003
24.  Off pump coronary artery bypass surgery for significant left ventricular dysfunction: safety, feasibility, and trends in methodology over time—an early experience 
Heart  2005;92(4):499-502.
To examine the safety and applicability of off pump coronary artery bypass surgery (OPCAB) in patients with significant left ventricular dysfunction and to discuss the clinical implications for the surgical methods.
Retrospective study.
Tertiary care university affiliated referral centre.
353 consecutive patients with preoperative left ventricular ejection fraction ⩽ 35% who underwent coronary artery bypass over a three year period.
Main outcome measures
Postoperative morbidity and mortality.
144 patients operated by OPCAB were compared with 209 patients operated by conventional coronary artery bypass. Multivariate and univariate analyses were performed on the pre‐ and postoperative variables to predict risk factors associated with hospital morbidity and mortality.
Patients in the OPCAB group were more likely to be women and to have congestive heart failure, chronic obstructive pulmonary disease, hypertension, and diabetes; patients in the on pump group were more likely to have had a recent myocardial infarction and to have more severe angina pectoris and an urgent/emergent status. The groups did not differ significantly in length of stay, major postoperative complication rates, or mortality. Comparison of the impact of the procedures on surgical methods over time showed an increase in the use of OPCAB (13% to 67%), without any impact on morbidity or mortality.
OPCAB is feasible and applicable for patients with depressed left ventricular function. This high risk group can potentially benefit from the off pump approach.
PMCID: PMC1860893  PMID: 15994913
low ejection fraction; off pump coronary artery bypass grafting; early experience
25.  Off-pump coronary artery bypass surgery in selected patients is superior to the conventional approach for patients with severely depressed left ventricular function 
Clinics  2011;66(12):2049-2053.
Patients with coronary artery disease and left ventricular dysfunction have high mortality when kept in clinical treatment. Coronary artery bypass grafting can improve survival and the quality of life. Recently, revascularization without cardiopulmonary bypass has been presented as a viable alternative. The aim of this study is to compare patients with left ventricular ejection fractions of less than 20% who underwent coronary artery bypass graft with or without cardiopulmonary bypass.
From January 2001 to December 2005, 217 nonrandomized, consecutive, and nonselected patients with an ejection fraction less than or equal to 20% underwent coronary artery bypass graft surgery with (112) or without (off-pump) (105) the use of cardiopulmonary bypass. We studied demographic, operative, and postoperative data.
There were no demographic differences between groups. The outcome variables showed similar graft numbers in both groups. Mortality was 12.5% in the cardiopulmonary bypass group and 3.8% in the off-pump group. Postoperative complications were statistically different (cardiopulmonary bypass versus off-pump): total length of hospital stay (days)—11.3 vs. 7.2, length of ICU stay (days)—3.7 vs. 2.1, pulmonary complications—10.7% vs. 2.8%, intubation time (hours)—22 vs. 10, postoperative bleeding (mL)—654 vs. 440, acute renal failure—8.9% vs. 1.9% and left-ventricle ejection fraction before discharge—22% vs. 29%.
Coronary artery bypass grafting without cardiopulmonary bypass in selected patients with severe left ventricular dysfunction is valid and safe and promotes less mortality and morbidity compared with conventional operations.
PMCID: PMC3226599  PMID: 22189729
Coronary artery bypass; cardiopulmonary bypass; off-pump surgery, ejection fraction, cardiac dysfunction

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