Clinical experience with a bifurcated endovascular graft for abdominal aortic aneurysm repair

Purpose: The purpose of this study was to test a transfemoral system of bifurcated endovascular graft insertion for aortic aneurysm repair.Methods: Bifurcated endovascular grafts were inserted through bilateral femoral artery cutdowns in 41 patients. The results were assessed by completion angiography and follow-up computed tomography.Results: The second half of the study included more aneurysms 6 cm or larger (p < 0.05) and more instances of short proximal neck (p < 0.05), proximal neck angulation (p < 0.05), and iliac angulation (p < 0.05). Despite the increasingly challenging anatomy, the results were better in the second half of the study as illustrated by the lower overall combined morbidity/mortality rate (15% vs 50%) and higher overall success rate (85% versus 65%). The mortality rate for the series as a whole was 7.5%. Mean follow-up was 18.8 months for the first 20 patients and 10.9 months for the second 20. The commonest complication in the first half of the study was graft thrombosis (n = 5). This complication was absent from the second half of the study because of routine adjunctive stenting. Two patients died of complications of endovascular repair. In both cases aneurysm rupture on the third postoperative day was associated with coagulopathy and angiographic signs of perigraft leak.Conclusion: Aneurysm exclusion with a bifurcated endovascular graft was feasible in a wide range of patients, but when the aneurysm was not entirely excluded from the circulation, the risk of rupture persisted. (J Vasc Surg 1996;24:655-66.)     

Successful renal transplantation after endovascular bifurcated stent graft repair of an abdominal aortic aneurysm

Renal transplantation after repair of aortoiliac aneurysms with traditional prosthetic vascular grafts has been shown to be effective. Vascular surgery continues to rapidly evolve, most notably with the advancement of endovascular repair of abdominal aortic aneurysms. Controlled trials continue to support the trend toward the use of endovascular bifurcated aortic stent grafts. For this we describe the first renal transplant in a patient with an endovascular bifurcated aortoiliac stent graft. No intraoperative difficulties were encountered. At 1-year follow-up, the transplanted kidney is functioning well with a normal serum creatinine level of 1.3 mg/dl, and the patient has no worsening of peripheral vascular disease. We recommend that the presence of an endovascular aortic graft not be a contraindication to renal transplantation.     

Mid-term results of patients undergoing endovascular aortic aneurysm repair

BACKGROUND: The utilization of endovascular aneurysm repair (EAR) is increasing significantly; however, few papers have outlined mid-term outcomes. METHODS: Patients undergoing EAR with an AneuRx endograft between September 1997 and May 2001 were evaluated. Mean follow-up was 20.7 +/- 11.9 (SD) months. RESULTS: In all, 101 EAR devices were successfully deployed in 105 attempts. Four open conversions (2 acute, 2 delayed) were performed for complications of EAR. Technical, clinical, and 1 to 3 year continuing success rates were 75%, 73%, and 78% to 83%. When divided by the median date, significantly fewer patients in the later group required secondary procedures compared with the early group. Vascular insufficiency occurred in 12 patients; 11 were treated with a secondary procedure. For 9 type I and 9 type II persistent endoleaks, secondary procedures were attempted and successful in 10 patients. Of successful EAR deployments, including secondary interventions, 85% demonstrated no persistent leak, rupture, increase in aneurysm size, or migration at most recent follow-up. CONCLUSIONS: EAR is successful in selected individuals; however, continuing follow-up is of paramount importance.     

Multicenter trial of the PowerLink bifurcated system for endovascular aortic aneurysm repair

PURPOSE: The purpose of this study was to assess the results of abdominal aortic aneurysm repair with the PowerLink bifurcated endovascular graft (Endologix, Inc, Irvine, Calif). METHOD: Twelve centers used the PowerLink bifurcated system for elective endovascular aneurysm repair in 118 patients recruited during a 16-month interval and followed for a 25-month interval (mean follow-up, 16 months) as part of a pivotal US Food and Drug Administration trial. Stent grafts were oversized by 10% to 20% relative to computed tomographic scan-based diameter measurements. All repairs were performed in the operating room through one surgically exposed femoral artery and a contralateral 9F sheath percutaneously placed. Results were assessed with contrast-enhanced computed tomography and plain abdominal radiography at 1, 6, and 12 months after surgery. RESULTS: Three failed insertions and one late conversion for endoleak remediation occurred, resulting in four conversions (3.3%) to open surgery. Of the failed insertions, two were from a faulty delivery system design, which was corrected. No failures occurred after the modification. One perioperative death (0.8%) occurred that was not device related. Eight late deaths were from unrelated causes, and one was from complications after reoperation for treatment of an endoleak. Endoleaks were noted in 19 patients (16%) at the time of the endograft procedure: 12 resolved spontaneously, four resolved with secondary interventions (three type I, one type II), and three underwent observation, yielding a 30-day endoleak rate of 5.9%. Two graft limb thromboses (0.8%) were seen. One graft migration (0.8%) was of no clinical significance. No ruptures or wire fractures were found. The mean aneurysm diameter was reduced from 51 mm (preoperative) to 45 mm (12 months; P <.0001). CONCLUSION: The PowerLink system appears to be safe and effectively protects patients from abdominal aortic aneurysm rupture over the short to medium term. The low endoleak rate is superior to that reported for other devices. The graft and stent materials have thus far been free from failure and fatigue. The sutureless stent and endoskeleton design confer a number of unique advantages and challenges. Careful follow-up over the longer term is necessary to assure the durability of these results.     

Midterm results of the multicenter trial of the powerlink bifurcated system for endovascular aortic aneurysm repair

PURPOSE: We assessed the results of abdominal aortic aneurysm (AAA) repair with the Powerlink bifurcated endovascular graft compared with open AAA repair. METHOD: A prospective controlled multicenter trial of the Powerlink system for endovascular aneurysm repair was conducted at 15 sites as part of a pivotal US Food and Drug Administration trial. Between July 2000 and March 2003, 258 patients (192 test patients, 66 control patients) were enrolled. Stent grafts were oversized by 10% to 20% relative to computed tomography scan (CT)-based diameter measurements. All repairs were performed in the operating room through 1 surgically exposed femoral artery and a contralateral 9F sheath percutaneously placed. Results were assessed with contrast material-enhanced CT scans and plain abdominal x-ray studies at 1, 6, and 12 months, and annually postoperatively. RESULTS: Patients were followed up for a mean of 22 months (median, 24 months). Technical success was achieved in 97.9% of patients, with 4 failed insertions (3 early conversions because of deployment issues, 1 access failure). There were no significant differences in mortality between the Powerlink and control groups, and only 1 death was procedure-related. Blood loss (341 mL vs 1583 mL; P < .0001), operative time (136 minutes vs 222 minutes; P < .0001), intensive care unit stay (0.78 days vs 4.1 days; P < .0001), and hospital length of stay (3.3 days vs 9.5 days; P < .0001) were significantly less in the Powerlink cohort compared with the control group. There were significantly fewer adverse events (myocardial infarction, P = .0131; renal failure, P = .0042; gastrointestinal complications, P = .0125) in the perioperative period in the Powerlink cohort compared with the control group, but in the longer follow-up interval adverse event-free survival was equivalent between groups (P = .456, log-rank test). At the time of the first-month CT scan, endoleaks were noted in 25 patients, yielding a 30-day endoleak rate of 22.7%. Type II endoleaks predominated, and there were no type III or IV endoleaks. Secondary procedures were performed in 19 patients (10%), for treatment of endoleak (n = 10), limb obstruction (n = 7), and other causes (n = 2). There were 3 graft migrations (2.2%), 1 of which resulted in an endoleak. There were no ruptures, graft fabric defects, or wire fractures. Significant reduction in mean AAA diameter and volume was noted at every follow-up interval. Increase in AAA diameter was noted in only 1.5% of patients at 24 months. CONCLUSION: The Powerlink system appears safe, and effectively protects patients from AAA rupture over the intermediate term. The graft and stent materials have thus far been free from failure and fatigue. Percutaneous contralateral limb access facilitates graft placement in patients with disadvantaged access routes. Endovascular aneurysm repair with the Powerlink system produces significantly fewer early adverse events compared with open AAA repair, but mortality is equivalent with both procedures. Careful follow-up over the longer term is necessary to ensure the durability of these results.     

The Powerlink bifurcated system for endovascular aortic aneurysm repair: four-year results of the US multicenter trial

The aim of the study was to review the results of abdominal aortic aneurysm (AAA) repair with the Powerlink Bifurcated endovascular graft, when compared with open AAA repair. A prospective, controlled, multicenter trial of the Powerlink System for endovascular abdominal repair (EVAR) was conducted at 15 sites as part of a pivotal FDA trial. Between July 2000 and March 2003, 258 patients were enrolled (192 test and 66 control patients). Stent grafts were oversized by 10-20% relative to computed tomography (CT)-based diameter measurements. All repairs were performed in the operating room through one surgically exposed femoral artery and a contralateral 9 French sheath percutaneously placed. Results were assessed using contrast-enhanced CT and plain abdominal X-rays at 1, 6, and 12 months and annually postoperatively. Mean follow-up of 36 months was available. Technical success was achieved in 97.9% of patients, with 4 failed insertions: 3 early conversions for deployment issues and one access failure. There was a significant difference in 30-day mortality between Powerlink (1%) and control (6.1%) patients and only 1 death was procedure-related (P=0.0389). Blood loss (341 mL vs 1 583 mL, P<0.0001), operative time (136 min vs 222 min, P<0.0001), Intensive Care Unit (ICU) stay (0.78 days vs 4.1 days, P<0.0001) and hospital length of stay (3.3 days vs 9.5 days, P<0.0001) were significantly less in the Powerlink cohort compared with controls. Secondary procedures have been performed on 16 patients post-implant to 48 months follow-up. At the time of the first month CT scan, endoleaks were noted in 25 patients, yielding a 30-day endoleak rate of 22.3%. Type II endoleaks predominated and there were no type III or IV endoleaks. The 4-year endoleak-free survival rate was 73%. No Type I, III or IV endoleaks were reported at 48 months post-implant. There have been no ruptures, graft fabric defects or wire fractures. Sac regression was noted in 83% of patients. Significant reduction in mean AAA diameter and volume was noted over every follow-up interval. In comparison to the 1-month post-implant CT scan, 2 patients had an increase in AAA diameter 5 mm at 48 months. The Powerlink system appears to be safe, and effectively protects patients from AAA rupture over the follow-up period. The graft and stent materials are still free from failure and fatigue. Contralateral limb access (9 Fr) facilitates graft placement in patients with disadvantaged access routes. EVAR performed with the Powerlink produces significantly less early adverse events than open AAA repair. Continued follow-up over the longer term is necessary to assure the durability of these results.     

Transfemoral insertion of a bifurcated endovascular graft for aortic aneurysm repair: the first 22 patients

The purpose of this study was to evaluate and optimize a system of transfemoral bifurcated graft insertion for endovascular repair of infrarenal aortic aneurysm. Grafts were inserted through bilateral femoral arteriotomies in 22 patients. Placement was guided by fluoroscopy. Results were assessed by completion angiography, with computed tomography scanning or duplex ultrasonography at 1,3 and 6 months. The first 11 insertions were complicated by failed insertion in two cases, proximal leakage in one, graft limb thrombosis in five and wound infection in one. The second 11 insertions were complicated by retrograde leakage around the distal graft orifice in two patients. One of these was associated with aneurysm rupture, leading to the sole mortality of the series. There were no instances of graft migration or embolism. In conclusion, the lessons learned during the first 11 insertions were responsible for the improved results apparent in the second 11 insertions. When applied in properly selected patients, transfemoral insertion of a bifurcated graft is a reliable method of isolating an aortic aneurysm from the circulation.     

Mid-term results after endovascular repair of the atherosclerotic descending thoracic aortic aneurysm.

INTRODUCTION: Thoracic aortic aneurysms (TAA) are the most common condition of the thoracic aorta requiring surgical treatment. Despite significant improvement in anesthetic, surgical techniques and postoperative care, the mortality and morbidity rate in TAA-repair remains high. The aim of this study was to assess the morbidity and mortality rate after endovascular stent-graft treatment of atherosclerotic (non-dissecting) TAAs. METHODS: Thirty-one patients, ASA-classification III-IV, with symptomatic or expanding atherosclerotic TAAs underwent endovascular stent-graft repair between May 1997 and August 2003. Procedures were performed on an emergency basis in 13 patients and elective in 18 patients. Patients were assessed postoperatively by routine CT-scan within 48 h. Further follow up investigations were performed after 3, 6, 12 months and annually thereafter. RESULTS: Stent-graft placement was successful in all but one patient in whom the stent-graft procedure had to be postponed due severe hemodynamic instability. Perioperative mortality rate was 19% including three haemorrhages, two cardiac events and one respiratory failure (6/31). Technical success rate was 55% (17/31). Completion CT scans performed in 30 patients within 2 days of stent-graft procedure showed type I leaks in seven patients (23%), type II leaks in four patients (13%) and type III leaks in two patients (6%). Further complications included one stroke, one paralysis, one spinalis anterior syndrome and five relevant access related complications. New onset endoleaks, all type I, were observed in seven patients (23%) occurring after 3, 4, 7, 8, 17, 25 and 26 months. Mean follow-up was 15 months (range 2-69 months). CONCLUSION: Thoracic aortic atherosclerotic aneurysm stent-grafting is feasible but not without significant morbidity and mortality.     

Endovascular repair of abdominal aortic aneurysm: one-year results of the French AneuRx trial

The purpose of this prospective study was to evaluate the results of abdominal aortic aneurysm (AAA) repair using the Medtronic AneuRx endovascular stent graft. Forty-seven patients presenting with asymptomatic AAA were recruited in 17 French vascular centers. The mean age of these patients was 72.2 ± 7.8 years (range, 54 to 85.2 years). Indications were validated by an independent committee and all procedures were supervised by a trained medicotechnical assistant. Clinical data and follow-up imaging were also reviewed by an independent committee. The primary end point was successful implantation, defined as exclusion of the aneurysm without mortality, morbidity, or reintervention. The secondary end point was durable exclusion at 1 year, assessed by serial computed tomography (CT scan). Implantation of the AneuRx endovascular stent graft in this series of highly selected patients was associated with no mortality and low morbidity. One-year follow-up findings showed reduction in aneurysm diameter in 45% of patients. This finding indicates that endovascular treatment is effective. However, observation of stable aneurysm diameter in 50% and increased aneurysm diameter in 5% suggests that careful, indefinite follow-up surveillance is necessary.     

Prosthetic stent graft infection after endovascular abdominal aortic aneurysm repair

OBJECTIVE: The purpose of this report is to discuss the incidence, diagnosis, and management of stent graft infections after endovascular aneurysm repair (EVAR). METHODS: Data were collected from the hospital database and medical case notes for all patients with infected endografts after elective or emergency EVAR for abdominal aortic aneurysm (AAA) during the last 8 years in two university teaching hospitals in Northern Ireland. The data included the patient's age, gender, presentation of sepsis, treatment offered, and the ultimate outcome. The diagnosis of graft-related sepsis was established by a combination of investigations including inflammatory markers, labelled white cell scan, computed tomography (CT) scan, microbiology cultures, and postmortem examination. RESULTS: Graft-related septic complications occurred in six of 509 patients, including 433 elective repairs and 76 emergency endografts for ruptured AAA. Two patients presented with left psoas abscess and were treated successfully with extra-anatomic bypass and removal of the infected stent graft. Two more patients presented with infected graft without other evidence of intra-abdominal sepsis: one underwent successful removal of the infected prosthesis with extra-anatomical bypass, and the other was treated conservatively and died of progressively worsening sepsis. The fifth patient presented with unexplained fever and died suddenly, with a postmortem diagnosis of aortoenteric fistula and ruptured aneurysm. The last patient presented with an aortoenteric fistula, was treated conservatively in view of concurrent myelodysplasia, and died of possible aneurysm rupture. CONCLUSION: This report emphasizes the need for continued awareness of potential graft-related septic complications in patients undergoing EVAR of AAA. Attention to detail with regard to sterility and antibiotic prophylaxis during stent grafting and during any secondary interventions is vital in reducing the risk of infection. In addition, early recognition and prompt treatment are essential for a successful outcome.     

Local anesthesia for endovascular abdominal aortic aneurysm repair

OBJECTIVES: This study reports the results of a prospective continuous cohort of patients treated for endovascular aneurysm repair (EVAR) with a unified anesthetic strategy based on the use of local anesthesia (LA) in all patients, while reserving regional (RA) or general anesthesia (GA) only for those with predefined individually or surgically specific indications. METHODS: All patients treated by EVAR for an elective aortic abdominal aneurysm (AAA) between April 1998 and December 2003 were included. The strategy of treatment generated three cohorts of patients (LA, RA, or GA). Primary outcome included all-cause mortality, nonfatal cardiac morbidity, respiratory complications, and renal failure. Secondary outcome measures included conversion to general anesthesia, use of analgesics, and time-related outcomes (operating time, length of stay in intensive care unit and hospital, time required to resume oral intake, and time to ambulation). RESULTS: A total of 239 patients underwent EVAR: 170 LA, 31 RA, and 38 GA. Overall mortality was one patient (0.4%). LA was associated with a lower incidence of complications compared with GA (P < .001). In the LA group, two patients had to be converted to GA, one because of a dissection and one because of anxiety. In 13% of the patients in the LA group, additional intravenous sedation or analgesia was required. Operating time and length of stay in intensive care was shorter in the LA and RA groups than in the GA group (P < .001). Length of stay in hospital and time to ambulation and regular diet was shorter in the LA group compared with the RA and GA groups (P < .001). CONCLUSIONS: A strategy based on the preferential use of LA for EVAR restricting RA or GA only to those with predefined contraindications is feasible and appears to be well tolerated.     

Successful endovascular repair in two cases of graft limb occlusion after endovascular aneurysm repair for abdominal aortic aneurysms

Among 148 abdominal aortic aneurysm patients who underwent endovascular aneurysm repair at our institution, two cases of graft limb occlusion (GLO) were identified and successfully treated with endovascular repair. Guidewire cannulation against the occluded limb is the most important aspect of the procedure. After a thrombectomy, balloon dilatation is performed followed by stent-graft deployment. Various procedures such as thrombectomy, thrombolysis, and extra-anatomical bypass have been adopted for the treatment of GLO. Our use of endovascular techniques, including overlapping stent grafts, has some benefits, namely, better patency of anatomical route revascularization, decreased risk of ipsilateral shower embolization due to the stent graft’s sealing over the irregular remnant thrombus, and easy access to angioplasty for tortured iliac arteries. However, shower embolization during catheter handling or future fabric failure due to friction is the potential complication associated with endovascular techniques. Intravascular repair techniques and stentgraft use should therefore be an early step of the GLO treatment algorithm.     

Cost-effectiveness of endovascular abdominal aortic aneurysm repair

BACKGROUND: The rapid introduction of endovascular abdominal aortic aneurysm repair (EVAR) has considerable implications for the management of abdominal aortic aneurysm (AAA). This study was undertaken to determine an optimal strategy for the use of EVAR based on the best currently available evidence. METHODS: Economic modelling and probabilistic sensitivity analysis considered reference cases representing a fit 70-year-old with a 5.5-cm diameter AAA (RC1) and an 80-year-old with a 6.5-cm AAA unfit for open surgery (RC2). Results were assessed as incremental cost-effectiveness ratio (ICER) compared with open repair (RC1) or conservative management (RC2). RESULTS: In RC1 EVAR produced a gain of 0.10 quality-adjusted life years (QALYs) for an estimated cost of 11,449 pound, giving an ICER of 110,000 pound per QALY. EVAR consistently had an ICER above 30,000 pound per QALY over a range of sensitivity analyses and alternative scenarios. In RC2 EVAR produced an estimated benefit of 1.64 QALYs for an incremental cost of 14,077 pound giving an incremental cost per QALY of 8579 pound. CONCLUSION:: It is unlikely that EVAR for fit patients suitable for open repair is within the commonly accepted range of cost-effectiveness for a new technology. For those unfit for conventional open repair it is likely to be a cost-effective alternative to non-operative management. Sensitivity analysis suggests that research efforts should concentrate on determining accurate rates for late complications and reintervention, particularly in patients with high operative risks.