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1.  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
2.  A Review of Surgically Treated Patients with Obstruction after Stenting in the Femoropopliteal Artery Region 
Annals of Vascular Diseases  2013;6(3):573-577.
In this study, we retrospectively reviewed 36 cases that required surgical treatment in the femoropopliteal regions (46 regions) because of the development of obstructions after stent placement in these patients. Of the 46, stents were placed in 37 involved regions (80.4%) that included the common femoral and popliteal arteries; such as the common femoral, entire length of superficial femoral, or popliteal arteries, and the anastomosis site created during femoropopliteal (prosthetic graft) bypass surgeries (Group A). In contrast, 9 involved regions (19.6%) did not include the common femoral or popliteal arteries; the stents were primarily localized in the superficial femoral artery (Group B). Symptoms of stent occlusion were more severe in the former group of patients, who subsequently required peripheral artery bypass surgery. These results indicate that placement of stents in the common femoral artery and popliteal arteries should be avoided. (*English translation of J Jpn Coll Angiol 2012; 52: 19-23)
PMCID: PMC3793177  PMID: 24130611
peripheral arterial disease; stent occlusion; stent fracture; endovascular treatment; femoropopliteal artery
3.  Multiple Sequential Complications After Sirolimus-Eluting Stent Implantation: Very Late Stent Thrombosis, Stent Fracture, In-Stent Restenosis, and Peri-Stent Aneurysm 
Korean Circulation Journal  2009;39(10):439-442.
A 55-year-old male patient presented with an acute myocardial infarction. A sirolimus-eluting stent (SES) was implanted in the proximal left anterior descending artery (LAD). Eight months later, there was a newly developed distal LAD lesion. An additional SES was implanted. Twenty-eight months after the index procedure of primary coronary intervention, the electrocardiogram showed ST elevation in the precordial leads and an emergency coronary angiogram showed diffuse stent thrombosis (ST) in the proximal LAD. Thirty-four months after the index procedure, coronary angiography showed a large peri-stent coronary aneurysm in the proximal LAD and focal in-stent restenosis (ISR) at the proximal edge of the distal LAD stent. On fluoroscopy, a fracture was noted in the middle part of the distal SES. A zotarolimus- eluting stent (ZES) was deployed and overlapped the restenosis and fracture sites. Forty months after the index procedure, there were no changes in the size of the aneurysm or in the other stent complications including the fracture and restenosis. At present, the patient has remained asymptomatic for eight months.
PMCID: PMC2771792  PMID: 19949591
Percutaneous transluminal coronary augioplasty; Drug-eluting stents
4.  Comparison of diamond-like carbon-coated nitinol stents with or without polyethylene glycol grafting and uncoated nitinol stents in a canine iliac artery model 
The British Journal of Radiology  2011;84(999):210-215.
Neointimal hyperplasia is a major complication of endovascular stent placement with consequent in-stent restenosis or occlusion. Improvements in the biocompatibility of stent designs could reduce stent-associated thrombosis and in-stent restenosis. We hypothesised that the use of a diamond-like carbon (DLC)-coated nitinol stent or a polyethylene glycol (PEG)-DLC-coated nitinol stent could reduce the formation of neointimal hyperplasia, thereby improving stent patency with improved biocompatibility.
A total of 24 stents were implanted, under general anaesthesia, into the iliac arteries of six dogs (four stents in each dog) using the carotid artery approach. The experimental study dogs were divided into three groups: the uncoated nitinol stent group (n = 8), the DLC-nitinol stent group (n = 8) and the PEG-DLC-nitinol stent group (n = 8).
The mean percentage of neointimal hyperplasia was significantly less in the DLC-nitinol stent group (26.7±7.6%) than in the nitinol stent group (40.0±20.3%) (p = 0.021). However, the mean percentage of neointimal hyperplasia was significantly greater in the PEG-DLC-nitinol stent group (58.7±24.7%) than in the nitinol stent group (40.0±20.3%) (p = 0.01).
Our findings indicate that DLC-coated nitinol stents might induce less neointimal hyperplasia than conventional nitinol stents following implantation in a canine iliac artery model; however, the DLC-coated nitinol stent surface when reformed with PEG induces more neointimal hyperplasia than either a conventional or DLC-coated nitinol stent.
PMCID: PMC3473868  PMID: 21325363
5.  Complete Fracture of Sirolimus-Eluting Stent in a Saphenous Vein Graft to Left Anterior Descending Artery 
Korean Circulation Journal  2009;39(6):251-253.
Coronary stent fractures have been suggested as a potential new mechanism of restenosis. The mechanical properties of stents were designed not only to prevent vessel recoil, but also to resist the mechanical stress of vessel movement over millions of cardiac cycles. We present a case in which mechanical stress may have contributed to the fracture of a stent implanted in a saphenous vein graft (SVG) to the left coronary artery. The patient was admitted due to chest pain 2 years after receiving a coronary artery bypass graft. A coronary angiography revealed the culprit vessel to be the SVG to the left coronary artery. The graft was stenosed and was stented with a sirolimus-eluting stent. A 6-month follow-up coronary angiography revealed 80% in-stent restenosis with stent fracture. We re-intervened by balloon angioplasty. This is the first report of sirolimus-eluting stent fracture combined with restenosis of SVG in Korea.
PMCID: PMC2771840  PMID: 19949631
Drug-eluting stents; Coronary artery bypass grafting
6.  An unusual case of ST-segment elevation myocardial infarction following a late bare-metal stent fracture in a native coronary artery: a case report 
A bare-metal stent fracture as a cause of acute coronary thrombosis and consequently of acute coronary syndrome is a rare clinical event that, to the best of our knowledge, has previously not been reported. A stent fracture is a rare complication arising from percutaneous coronary intervention.
Case presentation
We present, to the best of our knowledge, the first documented case of ST-segment elevation myocardial infarction in a patient following a late bare-metal stent fracture and thrombosis in a native coronary artery. The patient, a 51-year-old Caucasian man, was treated successfully with primary percutaneous coronary intervention and a new stent implantation.
A coronary stent fracture is a rare complication that has been described in venous bypass grafts deploying either a drug-eluting stent or a bare-metal stent. Stent fractures rarely occur in coronary arteries. In light of the non-specific presentation of stent fracture, it is also an easily missed complication. Patients may present with a non-specific symptom of angina. The angina could either be stable or unstable as a result of restenosis or in-stent thrombosis, or both. Our case demonstrates the most severe consequences of a bare-metal stent fracture (sudden coronary thrombosis and subsequent myocardial infarction) in a native coronary artery. It was diagnosed angiographically and treated early and effectively.
PMCID: PMC2803819  PMID: 20062785
7.  Very delayed coronary stent fracture: A case report 
A stent fracture is an emerging complication of the coronary stents. There are numerous risk factors for stent fractures; which include forceful exaggerated motion in the atrioventricular groove seen in right coronary artery, long stent, an ostial lesion at the point of maximum curvature in a tortuous vessel, stent over-expansion, stent overlapping with different size stents, complex lesion after stenting of a totally occluded vessel, Cypher stent and a highly mobile segment causing high mechanical stress. Furthermore, chronic stretch at specific vessel sites as bends may lead to late occurrence of fracture.
Here we report a case of 40-year-old male who had two overlapping Cypher stents (3.0 × 13 mm and 2.75 × 18 mm) deployed at mid left anterior descending artery 2 years earlier presented with progressive chest pain.
PMCID: PMC3727547  PMID: 23960657
Stent fracture; Coronary artery disease; Drug eluting stent; Sirolimus-eluting stent
8.  Fracture of Zotarolimus-Eluting Stent after Implantation 
Texas Heart Institute Journal  2009;36(6):618-620.
Drug-eluting stents were developed and approved for the reduction of in-stent restenosis. However, restenosis still occurs, and stent fracture is suggested as a cause of restenosis after implantation. Although sirolimus-eluting stents are considered to carry a high risk of fracture, the risk is also present with other drug-eluting stents. Herein, we report the case of a 78-year-old woman who received a zotarolimus-eluting stent for a bifurcation lesion of the left anterior descending coronary artery. Ten months later, she underwent coronary angiography due to angina. The angiogram revealed in-stent restenosis, with a grade IV stent fracture. After percutaneous coronary angioplasty, the patient's clinical symptoms improved.
PMCID: PMC2801950  PMID: 20069095
Blood vessel prosthesis implantation/instrumentation; coronary restenosis/diagnosis/etiology/prevention & control; drug-eluting stents; drug implants/adverse effects; prosthesis failure; retreatment; stents/adverse effects
9.  Stenting for Proximal Para-Anastomotic Stenosis 
Texas Heart Institute Journal  2002;29(1):45-47.
We present a case in which endovascular stenting was used for recurrent proximal para-anastomotic stenosis 11 years after aorto-bi-iliac bypass grafting for severe aortoiliac occlusive disease. A 55-year-old woman presented with worsening bilateral hip and buttock claudication. At presentation, her resting ankle-brachial indices were 0.87 bilaterally and decreased to 0.39 on the right and 0.40 on the left with exercise. Aortography demonstrated a proximal para-anastomotic aortic graft stenosis without distal outflow obstruction, patent superficial femoral arteries, and good triple-vessel runoff bilaterally.
The stenosis was dilated with a 9- × 4-cm OPTA balloon angioplasty catheter. A Palmaz stent (P424, Cordis) was mounted on a 10- × 4-cm OPTA balloon catheter and deployed across the proximal stenosis. Completion arteriography confirmed adequate placement and reduction in the degree of stenosis. There was no pressure gradient across the proximal anastomosis. At our patient's 1-week follow-up visit, her resting ankle-brachial indices were both greater than 1.0 and her exercise ankle-brachial indices were 1.0 bilaterally. She remained asymptomatic at 13 months.
Most late sequelae of aortic graft surgery involve the distal anastomosis and are resolved surgically without complicated techniques. However, revision at the proximal anastomosis involves the aorta directly and therefore requires open abdominal dissection and aortic cross-clamping. Percutaneous aortic stenting for primary aortoiliac disease has been shown to reduce operative time, cost, and hospital stays, to improve patency, and to be durable. Our clinical experience with aortic stenting for primary disease led us to consider this procedure for recurrent proximal stenosis. (Tex Heart Inst J 2002;29:45–7)
PMCID: PMC101269  PMID: 11995850
Angioplasty, balloon; aorta, abdominal; aortic diseases/therapy; arteriosclerosis/therapy; case report; female; graft occlusion, vascular/therapy; middle age; stents; vascular patency
10.  Circumferential Stent Fracture 
Texas Heart Institute Journal  2012;39(3):431-434.
Circumferential stent fracture is extremely uncommon, and in rare cases, it can cause stent thrombosis. Recognizing stent fracture can be difficult on conventional fluoroscopy because of poor stent radiopacity. We found that StentBoost image acquisition yields improved visibility of stent struts, enabling the identification of stent fracture and the precise positioning of new stents over previously stented segments.
We report the case of a 50-year-old man who presented with acute myocardial infarction and subacute stent thrombosis a week after percutaneous transluminal coronary angioplasty and placement of a bare-metal stent. The new lesion was crossed with a guidewire, but multiple attempts to advance a balloon catheter were unsuccessful. Live StentBoost image acquisition revealed circumferential stent fracture into 2 separate sections, with abnormal angulation between the proximal and distal portions of the stent. With StentBoost guidance, the wire and balloon catheter were both easily manipulated to cross the lesion, and angioplasty and restenting were completed with good results.
StentBoost can be a useful adjunctive tool for the cardiac interventionist during complex percutaneous transluminal coronary angioplasty, and it was invaluable in this challenging situation. We discuss stent fracture and the benefits of using StentBoost in such situations.
PMCID: PMC3368471  PMID: 22719162
Angioplasty, balloon, coronary/instrumentation; blood vessel prosthesis implantation; coronary restenosis/etiology/radiography; prosthesis failure; radiographic image enhancement/methods; radiographic image interpretation, computer-assisted/methods; stents; ultrasonography, interventional
11.  Multiple Recurrent Stent Thrombosis in a Patient with Coexisting Clopidogrel Resistance and Increased Anticardiolipin Antibodies: A Case Report 
Case Reports in Medicine  2010;2010:974149.
The antiphospholipid syndrome (APS) is a common cause of both arterial and venous thrombosis. While studies exist demonstrating the role of APS in coronary artery bypass graft failure, its role in stent thrombosis is less clearly documented. Also, a literature search of PubMed did not reveal any articles regarding the coexistence of clopidogrel resistance and APS despite increasing awareness of resistance to clopidogrel treatment. We present a case of a 59-year-old male having recurrent myocardial infarction after subacute restenosis of multiple drug-eluting stents despite anticoagulant therapy. The patient had in-stent thrombosis of seven drug-eluting stents in a course of eight days. He was subsequently found to have mild elevation of IgG anticardiolipin (aCL) antibody titers and resistance to clopidogrel. Long-term anticoagulation with a combination of low-molecular-weight heparin, clopidogrel, and aspirin has been effective. While the patient's aCL titer level was not elevated above the level required by the current diagnostic criteria for APS, we believe that this patient suffers from the antiphospholipid syndrome. We will discuss some of the controversies surrounding the diagnosis of APS as well as appropriate treatment and recognition of the coexistence of APS and clopidogrel resistance in patients with stent thrombosis.
PMCID: PMC2892706  PMID: 20592997
12.  A better effect of cilostazol for reducing in-stent restenosis after femoropopliteal artery stent placement in comparison with ticlopidine 
The purpose of this study was to assess the preventive effect of cilostazol on in-stent restenosis in patients after superficial femoral artery (SFA) stent placement.
Materials and methods
Of 28 patients with peripheral arterial disease, who had successfully undergone stent implantation, 15 received cilostazol and 13 received ticlopidine. Primary patency rates were retrospectively analyzed by means of Kaplan–Meier survival curves, with differences between the two medication groups compared by log-rank test. A multivariate Cox proportional hazards model was applied to assess the effect of cilostazol versus ticlopidine on primary patency.
The cilostazol group had significantly better primary patency rates than the ticlopidine group. Cumulative primary patency rates at 12 and 24 months after stent placement were, respectively, 100% and 75% in the cilostazol group versus 39% and 30% in the ticlopidine group (P = 0.0073, log-rank test). In a multivariate Cox proportional hazards model with adjustment for potentially confounding factors, including history of diabetes, cumulative stent length, and poor runoff, patients receiving cilostazol had significantly reduced risk of restenosis (hazard ratio 5.4; P = 0.042).
This retrospective study showed that cilostazol significantly reduces in-stent stenosis after SFA stent placement compared with ticlopidine.
PMCID: PMC3417878  PMID: 22915934
cilostazol; ticlopidine; stent; primary patency rate; peripheral arterial disease; superficial femoral artery
13.  Acute lower limb ischaemia due to delayed upstream migration of an iliac stent 
We report a case of acute limb ischaemia due to unusual upstream stent migration into the aorta 2 years after successful kissing stenting. Angiography showed a misplacement of both common iliac stent into the aorta, upstream migration with a fracture on the left external iliac stent into the iliac common artery, occlusion of the left iliac and femoral artery, dilatation of aortic bifurcation and stent separation on the right side. The patient underwent a successful axillo-bifemoral bypass graft. Vessel wall remodelling due to overestimation of stent size, aortic turbulence and rebound effect may explain this complication.
PMCID: PMC3279969  PMID: 22159244
Stent migration; Stent obstruction; Kissing stenting complication
14.  Very Late Development of Coronary Artery Aneurysm with Total Occlusion following Sirolimus-Eluting Stent Implantation 
A 41-year-old African American woman presented with chest pain and was found to have non-ST segment elevation myocardial infarction with a peak cardiac troponin I of 28.5. Elective cardiac catheterization revealed a 70% ostial left anterior descending (LAD) artery stenosis. The patient underwent percutaneous coronary intervention and a sirolimus-eluting stent (Cypher, Miami, FL, 3.5 × 8 mm) was successfully deployed. Three years after stent implantation, the patient presented with recurrent angina. Repeat coronary angiography revealed a large aneurysm involving the proximal portion of the stent with a total occlusion at the mid to distal portion of the stent with collaterals to LAD from left circumflex artery. The patient underwent coronary artery bypass surgery with left internal mammary artery graft to LAD and ligation of LAD at its origin proximal to the aneurysm.
PMCID: PMC3578606  PMID: 24293982
coronary artery aneurysm; coronary artery bypass; sirolimus-eluting stent; percutaneous coronary intervention
15.  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
16.  Randomised trial of elective stenting after successful percutaneous transluminal coronary angioplasty of occluded coronary arteries 
Heart  1998;79(1):18-23.
Background—The value of angioplasty in occluded coronary arteries is limited by a restenosis/reocclusion rate of 50-70%. In patients with subtotal occlusion, stent implantation has been shown to reduce clinical and angiographic restenosis. Retrospective observational studies have suggested that stenting could reduce restenosis in total occlusions. The value of sustained coronary patency on global and regional left ventricular function in this clinical setting has not been defined clearly.
Objectives—To assess the medium term effect of elective intracoronary stent deployment after successful percutaneous transluminal coronary angioplasty (PTCA) of an occluded coronary artery.
Methods—Sixty patients with a total coronary occlusion successfully treated by PTCA were randomised to receive an intracoronary stent or no stent. Patients underwent clinical and angiographic follow up at six months.
Results—Thirty patients received a stent (group A) and 30 were treated by angioplasty alone (group B), all with initial success. One patient in group B required repeat angioplasty with stenting at 24 hours and one patient died after 10 days. Angiographic follow up was available for 57 patients. This showed a significantly reduced reocclusion rate in group A compared with group B (7% v 29%, p < 0.01) and a tendency to a reduced restenosis rate (22% v 40%, p = 0.105) in patients with no reocclusion. Left ventricular function, both global and regional, improved in group A. Only the regional left ventricular function in the area supplied by the target coronary artery improved in group B. Recurrence of symptoms and clinical events such as repeat angioplasty, coronary artery bypass grafting, death or myocardial infarction tended to be reduced in group A (4 (13%) v 9 (30%)).
Conclusions—Intracoronary stent insertion is effective in reducing the rate of reocclusion and shows a trend towards reduced restenosis after opening of a total coronary occlusion by balloon angioplasty. Sustained patency of the target coronary artery is associated with improvement in global and regional left ventricular function.

 Keywords: intracoronary stenting;  total coronary occlusion;  left ventricular function
PMCID: PMC1728574  PMID: 9505913
17.  Successful Management of a Rare Case of Stent Fracture and Subsequent Migration of the Fractured Stent Segment Into the Ascending Aorta in In-Stent Restenotic Lesions of a Saphenous Vein Graft 
Korean Circulation Journal  2012;42(1):58-61.
Stent fracture is a complication following implantation of drug eluting stents and is recognized as one of the risk factors for in-stent restenosis. We present the first case of successfully managing a stent fracture and subsequent migration of the fractured stent into the ascending aorta that occurred during repeat revascularization for in-stent restenosis of an ostium of saphenous vein graft after implantation of a zotarolimus-eluting stent. Although the fractured stent segment had migrated into the ascending aorta with a pulled balloon catheter, it was successfully repositioned in the saphenous vein graft using an inflated balloon catheter. Then, the fractured stent segment was successfully connected to the residual segment of the zotarolimus-eluting stent by covering it with an additional sirolimuseluting stent.
PMCID: PMC3283757  PMID: 22363386
Coronary artery disease; Drug-Eluting stents; Complications
18.  Long-term Results for Primary Bypass vs. Primary Angioplasty/Stent for Intermittent Claudication Due to Superficial Femoral Artery Occlusive Disease 
Journal of Vascular Surgery  2012;55(4):1001-1007.
Percutaneous transluminal angioplasty +/− stent (PTA/S) and surgical bypass are both accepted treatments for claudication due to superficial femoral artery (SFA) occlusive disease. However, long-term results comparing these modalities for primary intervention in patients who have had no prior intervention has not been reported. We report our results with three year follow-up.
We reviewed all lower extremity bypass procedures at Beth Israel Deaconess Medical Center from 2001–2009 and all PTA/S performed from 2005 through 2009 for claudication. We excluded all limb salvage procedures and included only those that were undergoing their first intervention for claudication due to SFA disease. We recorded patient demographics, comorbidities, perioperative medications, TASC classification, and runoff. Outcomes included complications, restenosis, symptom recurrence, reinterventions, major amputation, and mortality.
We identified 113 bypass grafts and 105 PTA/S of femoral-popliteal lesions without prior interventions. Bypasses were above the knee in 62% (45% vein) and below the knee in 38% (100% vein). Mean age was 63 (bypass) vs. 69 (PTA/S) (P<.01). Mean length of stay (LOS) was 3.9 vs. 1.2 days (P<.01). Bypass grafts were used less for TASC A (17% vs. 40%, P<.01), and more for TASC C (36% vs. 11%, P<.01) and TASC D (13% vs. 3%, P<.01) lesions. There were no differences in perioperative (2% vs. 0%, NS) or 3 year mortality (9 vs. 8%, NS). Wound infection was higher with bypass (16% vs. 0%, P<.01). None involved grafts. Bypass showed improved freedom from restenosis (73% vs. 42% - 3 years, HR 0.4, 95% CI 0.23–0.71), symptom recurrence (70% and 36% at 3 years, HR 0.37, 95% CI 0.2–0.56), and freedom from symptoms at last follow-up (83% vs. 49%, (HR 0.18, 95% CI 0.08–0.40). There was no difference in freedom from reintervention (77% vs. 66% at 3 years, NS). Multivariable analysis of all patients showed that restenosis was predicted by PTA/S (HR 2.5, 95% CI 1.4–4.4) and TASC D (HR 3.7, 95% CI 3.5–9) lesions. Recurrence of symptoms was similarly predicted by PTA/S (HR 3.0, 95% CI 1.8–5) and TASC D lesions (HR 3.1, 95% CI 1.4–7). Statin use postoperatively was predictive of patency (HR 0.6 95% CI 0.35–0.97) and freedom from recurrent symptoms (HR 0.6 95% CI 0.36–0.93).
Surgical bypass for the primary treatment of claudication showed improved freedom from restenosis and symptom relief despite treatment of more extensive disease, but was associated with increased LOS and wound infection. Statins improved freedom from restenosis and symptom recurrence overall.
PMCID: PMC3319263  PMID: 22301210
19.  Three New Applications of Stent Technology in a Single Patient 
Texas Heart Institute Journal  2001;28(2):125-128.
The use of endovascular stents has become widely established in maintaining both arterial and venous patency in congenital heart disease. Stent implantation is now applied to pulmonary arterial stenoses, coarctation, pulmonary and systemic venous obstruction, and obstructed homografts and conduits, in both the pediatric and adult populations. The purpose of this report is to describe 3 new applications of stent technology: 1) double pulmonary artery stent implantation with simultaneous balloon dilation of a previously placed stent; 2) a new technique for traversing tight pulmonary arterial corners for stent delivery using the “sheath-within-sheath” method; and 3) a new technique for recannulation and stent implantation in unilateral femoral venous occlusion.
PMCID: PMC101152  PMID: 11453124
Balloon dilatation; femoral vein; heart defects, congenital; pulmonary artery; stents
20.  Simulation of stent deployment in a realistic human coronary artery 
The process of restenosis after a stenting procedure is related to local biomechanical environment. Arterial wall stresses caused by the interaction of the stent with the vascular wall and possibly stress induced stent strut fracture are two important parameters. The knowledge of these parameters after stent deployment in a patient derived 3D reconstruction of a diseased coronary artery might give insights in the understanding of the process of restenosis.
3D reconstruction of a mildly stenosed coronary artery was carried out based on a combination of biplane angiography and intravascular ultrasound. Finite element method computations were performed to simulate the deployment of a stent inside the reconstructed coronary artery model at inflation pressure of 1.0 MPa. Strut thickness of the stent was varied to investigate stresses in the stent and the vessel wall.
Deformed configurations, pressure-lumen area relationship and stress distribution in the arterial wall and stent struts were studied. The simulations show how the stent pushes the arterial wall towards the outside allowing the expansion of the occluded artery. Higher stresses in the arterial wall are present behind the stent struts and in regions where the arterial wall was thin. Values of 200 MPa for the peak stresses in the stent strut were detected near the connecting parts between the stent struts, and they were only just below the fatigue stress. Decreasing strut thickness might reduce arterial damage without increasing stresses in the struts significantly.
The method presented in this paper can be used to predict stresses in the stent struts and the vessel wall, and thus evaluate whether a specific stent design is optimal for a specific patient.
PMCID: PMC2525649  PMID: 18684321
21.  Neutrophil-derived cathelicidin protects from neointimal hyperplasia 
Science translational medicine  2011;3(103):103ra98.
Percutaneous transluminal angioplasty with stent implantation is used to dilate of arteries narrowed by atherosclerotic plaques and to revascularize coronary arteries occluded by atherothrombosis in myocardial infarction. Commonly applied drug-eluting stents release anti-proliferative or anti-inflammatory agents to reduce the incidence of in-stent stenosis. However, these stents may lead to in-stent stenosis and increase the rate late stent thrombosis, an obstacle to optimal revascularization possibly related to endothelial recovery. Here we examined the contribution of neutrophils and neutrophilic granule proteins to arterial healing after injury. We found that neutrophil-born cathelicidin (mouse CRAMP, human LL-37) promoted re-endothelization and thereby limited neointima formation after stent implantation. We then translated these findings, generating a neutrophil-instructing biofunctionalized miniaturized Nitinol stent coated with LL-37. This stent reduced in-stent stenosis in a mouse model of atherosclerosis, suggesting that LL-37 may promote vascular healing after interventional therapy.
PMCID: PMC3246402  PMID: 21974936
22.  Perioperative management of antiplatelet therapy in patients with drug-eluting stents 
Significant advancements in percutaneous treatment of coronary artery disease have been achieved with the introduction of bare metal stents. They have two major drawbacks: acute/subacute stent thrombosis, successfully managed with antiplatelet therapy immediately after stent implantation; and in-stent restenosis, prevention of which has been achieved with the development of drug-eluting stents. Drug-eluting stents have become preferred therapy for patients undergoing coronary artery intervention, though reports of late stent thrombosis have led to uncertainty about the duration of antiplatelet therapy after drug-eluting stents placement. Much controversy remains regarding perioperative management of patients with these devices, presenting for surgery or other invasive procedures. The purpose of this review is to provide an overview of the changing culture of coronary artery stenting, in addition to discussing perioperative management strategies and controversies surrounding coronary stents and antiplatelet therapy. A comprehensive literature search of MEDLINE was conducted using as keywords: antiplatelet therapy, non-coronary surgery, drug-eluting stents, and stent thrombosis. There is no definite standard of care for the perioperative management of drug-eluting stents in patients with drug-eluting stents. However, there is a growing understanding of the importance of continuation of drug-eluting stents in the perioperative period in order to prevent stent thrombosis along with a concern about the possibility of increased bleeding. Appropriate timing of surgery after coronary artery stenting, team approach to the perioperative management of such patients with involvement of cardiologist, anesthesiologist, and surgeon, and development of an individual plan for each patient, weighing that patient’s risk of thrombosis vs the risk of bleeding, could improve patient safety and optimize outcome.
PMCID: PMC3485386  PMID: 23439793
antiplatelet therapy; non-coronary surgery; drug-eluting stents; stent thrombosis
23.  Late Stent Thrombosis Associated with Heavy Exercise 
Texas Heart Institute Journal  2009;36(2):154-157.
Bare-metal stents are commonly used in the treatment of coronary artery disease. Stent thrombosis usually occurs within the first 48 hours after stent deployment. After a week, the incidence of thrombosis is low. Late stent thrombosis (after 30 days) is rarely seen; however, its clinical outcomes are severe 30-day mortality rates of 20% to 48% and myocardial infarction rates of 60% to 70%. Herein, we present the case and discuss the treatment of a patient who, after heavy exercise, experienced acute myocardial infarction due to late thrombosis in a bare-metal stent.
A 54-year-old man presented with unstable angina pectoris. Coronary angiography revealed critical occlusion of the middle right coronary artery. A bare-metal stent was implanted, and he was discharged from the hospital on a medical regimen. Eleven months later, he presented with acute myocardial infarction, which had developed after heavy exercise. Coronary angiography revealed occlusion of the stent in the right coronary artery. After the occlusion was crossed with a guidewire, balloon angioplasty was applied, and Thrombosis-in-Myocardial-Infarction (TIMI)-3 flow was restored. The patient was asymptomatic during his 5-day hospitalization and was discharged on dual antiplatelet therapy.
In addition to presenting this patient's case, we discuss mechanisms that may contribute to late stent thrombosis, implications of the condition, and preventive therapy.
PMCID: PMC2676600  PMID: 19436813
Aspirin/administration & dosage/therapeutic use; blood vessel prosthesis implantation/adverse effects; coronary disease/therapy; coronary restenosis/etiology/pathology/prevention & control/therapy; coronary thrombosis/etiology/therapy; exercise/physiology; myocardial revascularization; platelet aggregation inhibitors/administration & dosage; postoperative complications/etiology; stents/adverse effects; treatment outcome
24.  Delayed Migration of a WallFlex Enteral Stent Resulting in Jejunal Perforation 
Enteral stents are increasingly utilized to palliate malignant gastrointestinal obstruction; however, they can be associated with significant complications. We describe an unusual case of a 67-year-old male with gastric adenocarcinoma who underwent placement of a WallFlex metallic enteral stent to relieve a malignant gastric outlet obstruction. Four months later, while actively undergoing chemotherapy, he developed acute abdominal pain and was found to have delayed stent migration and jejunal perforation. He required emergent surgical resection of the perforated segment of jejunum. Delayed migration of the WallFlex enteral stent with subsequent visceral perforation has yet to be reported in the literature. Chemotherapy after stent placement has been associated with an increase in maintenance of stent patency; however, shrinkage of the local tumor by chemoradiation may increase the risk of stent migration. Care should be taken in placing enteral stents in patients undergoing continued treatment of their malignancy, as delayed migration of even uncovered stents may occur.
PMCID: PMC3654626  PMID: 23710382
25.  Longitudinal Stent Fracture and Migration of a Stent Fragment Complicating Treatment of Hepatic Vein Stenosis after Orthotopic Liver Transplantation 
We report a case of inferior vena cava (IVC) stent placement complicated by longitudinal stent fracture and migration of a stent fragment to the right pulmonary artery 2 years after initial placement. During attempted stenting of a hepatic venous anastomotic stenosis following orthotopic liver transplantation, a Palmaz P308 stent (Cordis International, Miami, FL) migrated and was redeployed into the IVC. Two years later, the patient had recurrent ascites and liver failure. Chest radiograph showed the Palmaz P308 stent had fractured longitudinally with a fragment in the right interlobular pulmonary artery. Half of the stent remained in the IVC. Mild stenosis was noted in the IVC where the stent was deployed. Overdilation of stents may be associated with stent fracture and should be performed with caution.
PMCID: PMC3036323  PMID: 21326480
Stent fracture; migration; Palmaz P308 stent

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