Gerald Zemel

Percutaneous Placement of a Balloon-expandable Intraluminal Graft for Life-threatening Subclavian Arterial Hemorrhage

A balloon-expandable intraluminal graft was percutaneously deployed in the left subclavian artery of a 43-year-old woman. This graft was made of a stainless steel, 30-mm Palmaz balloon-expandable iliac stent completely covered with a thin coat of silicone. The procedure was successful in managing and preventing life-threatening hemorrhage as a large-bore catheter was removed from the subclavian artery via its subcutaneous tunnel. Surgical repair of the high brachial-axillary sheath insertion site was required after percutaneous deployment of the graft. However, the grafting procedure succeeded in obviating a thoracotomy. At follow-up of 6 months, despite diminution in brachial pulse volume recordings, the patient is asymptomatic at rest. She experiences mild fatigue with extremes of upper extremity exercise and declines angiographic follow-up and further intervention.

Initial results of reteplase in the treatment of acute lower extremity arterial occlusions.

PURPOSE To assess the feasibility and efficacy of reteplase in transcatheter arterial thrombolysis for lower extremity occlusive disease. MATERIALS AND METHODS Fifteen consecutive patients with acute lower extremity ischemia due to occlusive disease were treated by means of catheter-directed thrombolysis with reteplase. Following diagnostic angiography, thrombolysis was started either from an antegrade puncture site in cases of femoropopliteal occlusions, or from the contralateral groin in cases of thrombosis of the iliac artery, common femoral artery, or infrainguinal bypass grafts. Reteplase was infused at a rate of either 0.5 U/h (six patients) or 1.0 U/h (nine patients). RESULTS Complete thrombolysis was achieved in all of the nine (100%) patients in the 1.0 U/h group and in four of six (66%) patients in the 0.5 U/h group for a combined success rate of 13 of 15 (87%). Clinical success was achieved in 11 of 15 patients overall (73%). Major bleeding complications occurred in none of the 9 patients in the 1.0 U/h group and in one (16%) of the six patients in the 0.5 U/h group for an overall rate of 6%. CONCLUSIONS Reteplase shows promise as an alternative to urokinase in the treatment of lower extremity ischemia due to arterial occlusive disease.

Directional atherectomy in the treatment of stenotic dialysis access fistulas

Directional atherectomy has proved useful in the treatment of peripheral vascular occlusive disease, and the authors have begun using this modality in the treatment of patients with failing hemodialysis access fistulas. The authors describe their initial experience with 13 patients in whom directional atherectomy was used to treat stenotic hemodialysis fistulas. Directional atherectomy was the sole treatment modality for eight patients. Three patients underwent atherectomy after unsuccessful percutaneous transluminal angioplasty (PTA). In two patients, unsuccessful atherectomy necessitated subsequent PTA. Directional atherectomy was successful in 10 of 13 patients. In seven of these 10 patients who are still alive, the dialysis fistulas remain patent. Directional atherectomy is a safe and useful technique in the percutaneous treatment of hemodialysis fistula stenosis. Early data indicate patency rates that may be higher than those reported with PTA.

Bivalirudin as an Anticoagulation Agent: Safety and Efficacy in Peripheral Interventions

PURPOSE Traditionally, unfractionated heparin is used to prevent thrombotic complications in peripheral interventions. The purpose of this study is to evaluate the use of bivalirudin as the anticoagulant agent for peripheral interventions. MATERIALS AND METHODS A retrospective analysis of 108 patients who underwent 110 peripheral interventions between January 2002 and January 2004 and received bivalirudin as the sole anticoagulation agent was conducted at Baptist Cardiac and Vascular Institute. Interventions were performed in the following areas: iliac, femoropopliteal, and distal (n = 55), carotid (n = 31), vertebral (n = 1), renal (n = 14), aorta (n = 7), and subclavian (n = 2). The following procedural and clinical endpoints were examined: death, requirement of urgent surgery or surgery during the same admission, urgent percutaneous revascularization in the same treated vessel, thrombotic or embolic events, bleeding events, and groin complications. RESULTS A total of 266 lesions were dilated in 185 arteries. There were no procedural mortalities, procedural success was 99.1%, and the complication rate was 3.6%. There was one embolic stroke (0.9%), one thrombosis (0.9%), and two groin hematomas (1.8%). No patient required urgent surgery or reintervention in the same treated vessel. No complications were noted at 7 days after the procedure. There were two interventions by postprocedure day 30: toe amputation and groin debridement. CONCLUSION Bivalirudin is a safe alternative to unfractionated heparin as the anticoagulation agent in peripheral interventions. This study shows that the complication profile is comparable to other bivalirudin studies. Bivalirudin is effective, easy to use, and is associated with few bleeding complications.

Creation of a Modified Angiography (Endovascular) Suite for Transluminal Endograft Placement and Combined Interventional-Surgical Procedures

PURPOSE To describe early experience with an endovascular suite created for procedures requiring surgical access, endograft placement, or combined surgical and interventional radiologic expertise. MATERIALS AND METHODS After examining the operating room and angiography environments, practice guidelines, state law, and regulatory agency requirements, a multidepartmental task force recommended reconfiguring an angiography suite to serve as an endovascular suite. Forty patients have been treated; 28 underwent vascular endograft placement and 12 underwent other combined procedures. RESULTS Procedures included 31 femoral and axillary cutdowns; placement of one aortobifemoral graft, two iliofemoral grafts, two femoropopliteal grafts, and two femoral-femoral crossover grafts; two abdominopelvic exposures for aortic access, and five endarterectomies, including one at the carotid bifurcation performed in combination with common carotid stent placement. Three of the abdominopelvic procedures were not planned, including two emergency conversions. No patient had to be moved to an operating room. There was one major infection (2.5%), two minor wound infections (5%), and one wound with delayed healing (2.5%). CONCLUSION Early experience with a combined surgical-interventional suite has been favorable, but a vigilant approach is warranted.

Low-Dose Urokinase Regimen for the Treatment of Lower Extremity Arterial and Graft Occlusions: Experience in 132 Cases

In a retrospective review, a low-dose urokinase (UK) infusion regimen (mean, 87,000 U of UK per hour and 100 U of heparin per hour) was evaluated for lower extremity arterial and graft occlusions. Results of 132 infusions in 111 patients were analyzed to determine efficacy, limb salvage, and complications. Angiographic success was achieved with 126 infusions (95%), and amelioration of presenting signs and symptoms was achieved after 116 infusions (88%). Patients who underwent additional percutaneous procedures were more likely to have a successful outcome. There was no significant difference in success rates for patients receiving low-dose heparin through the arterial sheath (n = 101) versus those receiving concomitant systemic heparinization (n = 29), (P = .08) [corrected]. Of 88 threatened extremities (with rest pain, cold, ulcers, or gangrene), nine were amputated (limb salvage = 90%), accounting for 82% (nine of 11) of amputations in the overall study. Patients with zero- or one-vessel runoff before infusion were more likely to require limb amputation compared with the group with two- or three-vessel runoff before infusion (P less than .01). Major periprocedural complications occurred in nine of 132 (7%) infusions, five of which necessitated specific surgery and/or transfusion for bleeding. Pericatheter thrombosis was not encountered in either subgroup. This standard local low-dose infusion represents a safe and effective treatment for lower extremity arterial and graft occlusions.

Influence of Stent Type on Hemodynamic Depression after Carotid Artery Stent Placement

PURPOSE To assess the effect of stent type on hypotension and bradycardia after carotid artery stent placement. MATERIALS AND METHODS A retrospective analysis on a prospectively maintained database was conducted in 256 patients (126 men; mean age, 71.8 years +/- 8.6; 194 de novo lesions) undergoing carotid artery stent placement between January 1996 and January 2007 by using self-expanding stents. Braided Elgiloy stents (Wallstents) were used in 44 of the 256 patients (17.2%) and slotted-tube nitinol stents were deployed in 212 (82.8%). Bivariate and multivariable logistic regression models were used to determine the influence of stent design on procedural and 24-hour hypotension and bradycardia. RESULTS Procedural hemodynamic depression (HD) was encountered in 73 of the 256 patients (28.5%) due to hypotension in 24 (9.4%), bradycardia in 12 (4.7%), or both in 37 (14.5%) patients. Rates of procedural hypotension were 11.3% with nitinol stents and 0% with braided Elgiloy stents (P = .0188). Persistent postprocedural HD occurred in 91 of the 256 patients (35.5%) due to hypotension in 40 patients (15.6%), bradycardia in 23 (9.0%), or both in 28 (10.9%). Within a multivariable analysis adjusted for clinically relevant factors affecting rates of HD, the use of braided Elgiloy stents was associated with a decreased rate of procedural hypotension (odds ratio: 0.165; 95% confidence interval: 0.038, 0.721; P = .017). Procedural hypotension and bradycardia were not correlated to incidence of major adverse events but were associated with an increased duration of hospital stay (P = .0059 and P = .0335, respectively). CONCLUSIONS Nitinol stents are associated with a higher risk of hypotension as compared to braided Elgiloy stents during carotid artery stent placement.

Postoperative management: type I and III endoleaks.

The purpose of this article is to help the reader understand the importance of imaging findings and treatment strategies for type I and III endoleaks. Although the appearance of these leaks on computed tomography can be somewhat unremarkable and similar in appearance to type II endoleaks, it is critically important for the treating physician to make the correct diagnosis, as these endoleak types signify an incompletely treated aneurysm. Once the diagnosis of a type I or III endoleak is made, the next step in treatment is to identify the cause of the endoleak. Incomplete initial graft expansion, further arterial dilation, endograft migration, component separation, and tears within the graft fabric are all possible causes of type I and III endoleaks. A combination of computed tomography, plain film radiography, and diagnostic angiography may be necessary to make the diagnosis and identify the underlying cause of the complication. Once all of these factors have been determined, a decision has to be made of whether the endoleak can be treated through additional endovascular means or if endovascular therapy has failed for the patient, making open surgical revision necessary to treat the aneurysm. Illustrative cases of all endoleak types and their treatments are the focus of this article.

Persistently increased expression of the transforming growth factor-β1 gene in human vascular restenosis: Analysis of 62 patients with one or more episode of restenosis☆

Transforming growth factor-beta-1 (TGF-β1) is a multifunctional cytokine with both growth-promoting and growth-inhibiting properties. Moreover, there is abundant evidence that TGF-β1 is the principal growth factor responsible for regulating proteoglycan synthesis in human blood vessels. To determine the potential contribution of TGF-β1 to restenosis, the current investigation sought to determine the time course of expression postangioplasty of the TGF-β1 gene. In situ hybridization was performed on tissue specimens obtained by directional atherectomy from 62 patients who had previously undergone angioplasty of native coronary or peripheral arteries and/or saphenous vein bypass grafts. The time interval between angioplasty and atherectomy was 1 hour to 25 months (M ± SEM = 5 ± 4 months) for all 62 patients, 5 ± 4 months for coronary arterial specimens, 8 ± 5 months for vein graft specimens, and 7 ± 3 months for peripheral arterial specimens. TGF-β1 mRNA expression remained persistently increased independent of the site from or time interval following which the specimen was obtained. For saphenous vein by pass grafts, TGF-β1 expression was highest in specimens retreived from patients with multiple versus single episodes of restenosis (16 ± 5 vs. 6 ± 5 grains/nucleus, p < 0.01). TGF-β1 expression did not correlate with patient age, sex, or known risk factors for coronary heart disease. The persistently augmented expression of TGF-β1 observed in the present series of restenosis lesions provides further support for the concept that TGF-β1 influences growth and development of restenosis plaque.

Stent Grafts for Aortic Aneurysms: The Next Interventional Challenge

Stent grafts (endografts) have proved useful for the endoluminal exclusion of peripheral and aortic aneurysms, both those in native arteries and those resulting from prior surgery. In addition, their use may apply in some patients with occlusive vascular disease. Various types of endografts are being evaluated in clinical trials, including those that utilize unsupported grafts with stentlike attachment mechanisms and those having a metallic endoskeleton or exoskeleton. Relatively complex devices can be delivered through small arteriotomies and in some cases percutaneous approaches. Unsupported grafts, although more prone to kinking and incomplete expansion, appear to work well. Some devices employ modularity, which involves separate placement of contralateral limbs and, in some cases, extension devices. For performing endovascular grafting, pretreatment planning is critical and requires sophisticated imaging, including spiral computed tomography (CT) with 3-dimensional reconstruction and angiographic evaluation using catheters with calibrated markers. Potential advantages of endovascular grafts include a decreased hospital stay, a less invasive procedure, and lower morbidity and mortality. Several issues remain unresolved and should be addressed by the newer generation of these devices.