Shaun Samuels

Management of Misplaced or Migrated Endovascular Stents

PURPOSE To report experience with techniques for management of misplaced or migrated endovascular stents. MATERIALS AND METHODS During a 5-year period, percutaneous management of 27 misplaced or migrated endovascular stents (16 Palmaz, 11 Wallstents) in 25 patients was attempted. The 17 venous and 10 arterial stents were rescued from the aorta (n = 9), inferior vena cava (IVC) (n = 4), transjugular intrahepatic portosystemic shunt/IVC (n = 2), right atrium (n = 3), right ventricle (n = 2), pulmonary artery (n = 2), iliac vein (n = 2), iliac artery (n = 1), superior vena cava (n = 1), and superior mesenteric vein (n = 1). RESULTS Stent management was successful in 26 of 27 cases (96%). Eleven stents were removed percutaneously, two were repositioned and removed with a minor surgical procedure, and 13 were repositioned and deployed in a stable alternate location. The only complication was the development of tricuspid insufficiency in the single case in which the procedure failed (4% complication rate). This patients stent was eventually surgically removed from the right ventricle. CONCLUSION Misplaced or migrated endovascular Palmaz and Wallstents can be effectively managed with few complications by using a variety of percutaneous techniques.

Dr. Gary J. Becker Young Investigator Award: Intraarterial adenovirus for metastatic gastrointestinal cancer: Activity, radiographic response, and survival

PURPOSE To determine the antitumoral activity and radiographic response pattern of intraarterial administration of a selective replication-competent adenovirus in patients with hepatic metastases from gastrointestinal carcinomas. MATERIALS AND METHODS Thirty-five patients were treated, seven in the dose-escalation phase and 28 at high doses. Inclusion criteria allowed mild laboratory value and performance status abnormalities and as much as 50% replacement of hepatic volume by tumor. An attenuated adenovirus that selectively replicates in p53-deficient cells (Onyx-015) was administered by hepatic arterial infusion at doses as high as 2 x 10(12) particles for two cycles. Subsequent cycles (maximum of eight total) were administered in combination with intravenous 5-fluorouracil (5-FU) and leucovorin. RESULTS Tumor responses were demonstrated in combination with chemotherapy, even in 5-FU-resistant patients. The 15 patients who responded radiographically showed a pattern of acute tumor enlargement despite normalization of laboratory and clinical parameters, followed by very slow regression of tumor size. Radiographic response did not correlate with p53 status. Median survival of radiographic responders (475 days) was significantly longer than that of nonresponders (143 days). CONCLUSIONS Hepatic arterial infusion of the replication-selective adenovirus Onyx-015 in combination with chemotherapy resulted in tumor regressions in select patients, including some in whom previous chemotherapy had failed. A biphasic radiographic response pattern was demonstrated. The mechanism of action appears to be more complex than that seen in vitro.

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.

Treatment of Aortoiliac Aneurysms with Use of Single-Piece Tapered Stent-Grafts

PURPOSE The authors describe their experience with the use of single-piece, tapered stent-grafts for the treatment of abdominal aortic or aortoiliac aneurysms. MATERIALS AND METHODS Single-piece, tapered stent-grafts were placed in 15 patients for the treatment of abdominal aortic aneurysms with small distal necks (n = 13), and aortoiliac aneurysms (n = 2). There were 13 men and two women who ranged in age from 59 to 83 years (mean, 71 years). Usual open surgery was considered high risk in all patients because of comorbid medical conditions. The stent-grafts were made of Z stents covered with polytetrafluoroethylene (PTFE). Additional stent-grafts needed to treat perigraft leaks were made of Z stents covered with woven polyester (n = 5), Wallstents covered with PTFE (n = 2), Z stents covered with PTFE (n = 1), and a PTFE-covered Palmaz stent (n = 1). After stent-graft placement, the contralateral iliac artery was occluded by a blocking device composed of either a PTFE-covered Palmaz (n = 1) or Z stent (n = 13), and a femoral-femoral bypass was created. RESULTS After placement of the stent-grafts, immediate perigraft leaks were observed in eight patients (53%). These were at the proximal (n = 5) or the distal end (n = 3). All, except one, were treated successfully with additional stent-grafts. The one failure was in a patient who developed aortic rupture after balloon dilation, requiring open surgical repair. Second procedures were required in four patients (27%), including three leaks treated successfully with coil embolization and/or a back-up stent-graft, and one stent-graft migration and thrombosis treated by thrombolysis and placement of an additional stent-graft. One patient died of respiratory failure 23 days after placement of the stent-graft. The mean follow-up was 12 months (range, 4-26 months). On the last follow-up, the aneurysms in the 13 living patients remained thrombosed. CONCLUSION Treatment of aortoiliac aneurysms with use of single-piece, tapered stent-grafts is feasible in selected patients. The morbidity and mortality rates compare favorably with those of the open surgical procedures in a high-risk population. Further improvements in the technique and longer follow-up data are needed before this procedure can be recommended for the treatment of all aortoiliac aneurysms.

Ultrasound-accelerated vs Standard Catheter-directed Thrombolysis—A Comparative Study in Patients with Iliofemoral Deep Vein Thrombosis

PURPOSE To compare the thrombolytic efficacy and safety of standard catheter-directed thrombolysis (CDT) and ultrasound (US)-accelerated thrombolysis (UAT) for the treatment of iliofemoral deep vein thrombosis (DVT). MATERIALS AND METHODS All medical records of patients who underwent CDT or UAT for DVT between June 2004 and October 2011 at a single tertiary care center were reviewed. Target vein patency was graded according to a reporting standard by an independent interventional radiologist. RESULTS CDT was performed in 19 patients and UAT in 64 patients. The baseline parameters and DVT characteristics, including the duration of symptoms, the location, and the extension did not differ significantly between groups. Both treatment modalities were associated with a similar substantial resolution of thrombus load (CDT = 89%; interquartile range [IQR], 70%-100%; UAT = 82%; IQR, 55%-92% (P = .560). No significant differences in the lytic drug infusion rates, the total lytic doses, the total infusion time, and the use of adjunctive procedures were observed between groups. Major and minor bleeding complications were observed in 8.4% and 4.8% of the patients, with no difference between the treatment groups (P = .709 and P = .918, respectively). During a median follow-up of 35 months (20-55 months), three deaths and 16 cases of repeated thrombosis were observed. The estimated mean event-free survival time was longer after CDT (69 mo) compared with UAT (33 mo) (log-rank test P = .310). CONCLUSIONS The present study failed to prove any substantial clinical benefit provided by UAT with regard to effectiveness or safety compared with standard CDT. Given the added costs of the US delivery device, prospective randomized data are needed to justify its widespread use for DVT treatment.

Transapical Endovascular Aortic Repair to Treat Complex Aortic Pathologies

Clinical condition, hostile anatomy, and previous heart/aortic surgery may preclude standard open surgery and standard endovascular interventions in patients with complex aortic pathologies. We report our initial experience using the transapical endovascular approach to treat a type IA endoleak after transfemoral endovascular graft repair for a contained rupture of a penetrating descending aortic ulcer; an ascending aortic anastomotic pseudoaneurysm after open surgical repair of an ascending aortic dissection; and a type A aortic dissection after minimally invasive mitral valve repair. There were no neurologic or cardiovascular complications, and the 30-day mortality was 0%.

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.

Direct Percutaneous Sac Injection for Treatment of a Thoracic Type II Endoleak

Bleeding into the cyst resulted in another serious condition, ie, infection of the cyst, which required prolonged intensive care treatment, including administration of antibiotic agents, percutaneous drainage, and spigot placement in the bronchus. In summary, we report a case of bleeding into a pulmonary cyst as a result of pulmonary RF ablation. The bleeding subsequently resulted in respiratory arrest. Although the patient was resuscitated, the cyst subsequently became infected, and the patient required prolonged treatment.