Graft-related complications after abdominal aortic aneurysm repair: reassurance from a 36-year population-based experience

Infección asociada a prótesis vascular: manejo exitoso sin retirada de prótesis

INTRODUCTION

Removal of graft with intravenous antibiotics is traditionally considered the most effective treatment of vascular graft-associated infections. However, an increasing number of reports suggests that this complication can be effectively treated without graft removal.

METHODS

A prospective study to evaluate the outcome of conservative management of vascular graft-associated infection seen in our center was performed. The diagnosis of graft-associated infection was based on microbiological tests, and imaging studies. In our study, patients were hemodynamically stable with functioning vascular graft as per clinical and imaging evaluations. Conservative management included antibiotic treatment and local debridement without removal of vascular graft.

RESULTS

Fourteen patients with vascular graft-associated infection were enrolled in our study. Eleven out of 14 patients (78.6%) responded successfully to conservative management. Treatment failure was reported in 3 patients, 2 of whom required graft removal. After a two-year follow-up, these 14 patients were clinically stable without recurrence of infection.

CONCLUSIONS

Our study has revealed that conservative management of vascular graft-associated infection seems to be effective and should be considered in hemodynamically stable patients with functioning vascular graft.

Long-term postplacement cost after endovascular aneurysm repair

BACKGROUND

Previous studies have demonstrated that the initial hospital cost associated with endovascular aneurysm repair (EVAR) is approximately $20,000. However, the cost of long-term surveillance and secondary procedures is poorly characterized.

METHODS

Between December 1998 and June 2006, 259 patients underwent EVAR for infrarenal aneurysms at a single institution. Follow-up costs were calculated using a relative value unit based hospital cost accounting system, which incorporates departmental direct and indirect costs. Institutional overhead costs were included using a conversion factor. Costs for professional services were determined by a cost-to-charge ratio, and outpatient visits were calculated with a time-based formula. Year 2006 costs were applied to prior years. To minimize costs associated with the early learning curve, the initial 50 EVAR patients between December 1995 and 1998 were excluded. Patients with <1 year follow-up were also excluded. Data are expressed as mean +/- standard error.

RESULTS

The mean follow-up after EVAR for 136 patients was 34.7 +/- 1.8 months. The cumulative 5-year postplacement cost per patient was $11,351. The 27 patients (19.9%) who required secondary procedures had a 5-year cumulative cost of $31,696 compared with $3668 for 109 patients without secondary procedures (8.6-fold increase, P < .05). The 5-year cost for patients with endoleak was $26,739 compared with $5706 for those without endoleak (4.7-fold increase, P < .05). Overall, major cost components were 57.4% for secondary procedures and 32.5% for radiologic studies.

CONCLUSIONS

During a 5-year period, the postplacement cost of EVAR increases the global cost by 44%. The subgroups of patients with endoleaks and those requiring secondary procedures generate a disproportionate share of postplacement costs. Efforts at minimizing cost should emphasize technical and device modifications aimed at reducing endoleaks and the need for secondary procedures.

Endovascular abdominal aortic aneurysm repair

The operative mortality following conventional abdominal aortic aneurysm (AAA) repair has not fallen significantly over the past two decades. Since its inception in 1991, endovascular aneurysm repair (EVAR) has provided an alternative to open AAA repair and perhaps an opportunity to improve operative mortality. Two recent large randomised trials have demonstrated the short and medium term benefit of EVAR over open AAA repair, although data on the long term efficacy of the technique are still lacking. This review aimed at providing an overview of EVAR and a discussion of the potential benefits and current limitations of the technique.

Fungal Infection of Aortoiliac Endograft: A Case Report and Review of the Literature

Infection of aortoiliac endografts is, to date, a rare complication of endovascular surgery. Staphylococcus species are the most common responsible pathogens, just as in cases with infected grafts after open aortic surgery. We report a case of a 65-year-old man with a history of diabetes mellitus and bladder cancer who developed stent-graft infection 3 years after endovascular treatment for a 5.6 cm abdominal aortic aneurysm. The diagnosis of endograft infection was established radiologically by computed tomographic scans. After intravenous administration of antibiotics and fluids to improve his clinical condition, the patient underwent surgical excision of the infected prosthesis and a bifurcated rifampicin-impregnated Dacron graft was placed in situ. Cultures from the purulent fluid around the aorta and from the endograft revealed development of Candida albicans. To our knowledge, this is the first case of an infected endograft due to a fungus. The patient died from septic shock 3 days postoperatively in the intensive care unit.

Should usual criteria for intervention in abdominal aortic aneurysms be "downsized," considering reported risk reduction with endovascular repair?

Two randomized trials have demonstrated the safety of waiting until abdominal aortic aneurysm (AAA) diameter reaches 5.5 cm for repair in most patients. Other recent randomized trials have demonstrated lower perioperative mortality and morbidity with endovascular aneurysm repair (EVAR) compared to open surgery. Therefore, it is logical to assume that endovascular repair may change the appropriate threshold for intervention. However, endovascular repair is not as durable as open surgery and is associated with ongoing risks of rupture and reintervention. Decision analysis based on data available in 1998 showed that endovascular repair should not change the threshold for intervention. Since that time retrospective data have emerged to suggest that outcomes with endovascular repair are improved in smaller AAAs, although this may simply represent selection bias and the natural history of small AAAs. Randomized trials are appropriate to determine whether improved endovascular outcomes in small AAAs reduce late rupture and reintervention enough to justify early intervention in patients with appropriate anatomy. In the absence of data from these trials, the threshold for intervention should not be changed.

Pathology, natural history and treatment of abdominal aortic aneurysms

With increasing age of the population and improvement of diagnostic tools, the incidence of abdominal aortic aneurysms (AAA) has been rising steadily. Despite an improvement in operative and interventional treatment options, AAA is the cause of death in 1-3% of men over 65 years of age in industrial countries, mostly due to rupture [1]. Therefore, routine screening for AAA by ultrasonography has been postulated in the past: a 60 year old man with an abdominal aortic diameter of less than 3 cm has a life-time risk of developing AAA close to zero. However, routine screening has not been found to be cost effective. Despite of the results of two well-designed studies, the limits of AAA qualifying the patient for surgery or intervention in contrast to conservative treatment is still a matter of debate. The present review article summarizes the current knowledge of the pathology, incidence, risks, natural course as well as symptoms and current treatment strategies of AAA on the basis of the recent literature.

Current Status of Endovascular Repair of Infrarenal Abdominal Aortic Aneurysms in the Context of 50 Years of Conventional Repair

The operative risk for conventional open repair of nonruptured infrarenal abdominal aortic aneurysms (AAAs) has steadily declined during the past several decades to the point that open procedures now can be done with a mortality rate of approximately 2% at tertiary referral centers. Nevertheless, population-based studies suggest that the mortality rate for open AAA repair remains nearly 7% in many communities, a finding that undoubtedly is influenced by a substantial risk for unfavorable outcomes in patients who represent less than ideal candidates for major abdominal operations on the basis of advanced age and the medical comorbidities that so often accompany it. Endovascular aneurysm repair (EVAR) is a landmark contribution to the management of such patients and has been associated with significant overall reductions in the operative mortality rate in statewide and national audits. This early advantage of EVAR comes at the price of a unique set of complications, secondary interventions, and related expenses, however, and randomized clinical trials of EVAR versus open repair have not yet demonstrated differences in survival or quality of life within 4 years of follow-up. Data from the Nationwide Inpatient Sample and other sources indicate that the mortality rate for open AAA repair appears to be less than 2% in patients who are 65 years of age or younger. This low operative risk may not justify exposure to whatever incidence of late complications the current generation of endografts may prove to have during the relatively long survival times that can be anticipated for these patients.

Endovascular Treatment of Peripheral Vascular Disease

An estimated 10 million people in the U.S. have symptomatic peripheral arterial disease (PAD); 20 to 30 million have asymptomatic PAD. The prevalence of intermittent claudication increases with age, affecting >5% of patients over 70. The incidence of claudication doubles or triples in patients with diabetes. As people grow older, symptoms from peripheral vascular disease increasingly limit daily activity. Until recently, vascular surgical procedures were the only alternative to medical therapy in such patients. Today, advances in minimally invasive percutaneous interventions have made endovascular procedures the primary modality for revascularization in most patients. Compared with open surgical procedures, endovascular interventions offer comparable or superior long-term rates of success with very low rates for morbidity and mortality. Furthermore, most of these interventions are performed on an outpatient basis, reducing hospital stays considerably. In this monograph we discuss current endovascular interventions for treating occlusive PAD, aneurysmal arterial disease, and increasingly common venous occlusive diseases.

Evolving strategies for the treatment of aortoenteric fistulas

BACKGROUND

Aortoenteric fistulas (AEFs) are a rare but often fatal cause of gastrointestinal bleeding. Operative repair of AEF has been historically associated with extremely high morbidity and mortality. We reviewed our experience of open surgical and endovascular treatment of AEF to compare outcomes over a contemporaneous time period.

METHODS

Over a 9-year period between January 1997 and January 2006, 16 patients (11 men and 5 women) were diagnosed with and treated for AEFs. Seven patients underwent open surgical repair, and nine, with anatomically suitable lesions, underwent endovascular repair. The outcome after treatment of these patients was investigated for survival, perioperative complications, length of hospital stay, and long-term disposition.

RESULTS

Three primary and 13 secondary AEFs were treated. The mean time from the initial aortic operation until AEF diagnosis was 5.9 years (range, 0.7-12.2 years) for patients with secondary AEFs. The overall 30-day mortality rate was 18.8%. One intraoperative death and one in-hospital death secondary to multisystem organ failure occurred in patients undergoing open repair. One in-hospital death related to persistent sepsis occurred in the endovascular group. The overall perioperative complication rate was 50.0%. Complications in the open group included sepsis, renal failure, bowel obstruction, and pancreatitis. Complications in the endovascular group were related to persistent sepsis. The mean in-hospital length of stay was significantly longer for patients undergoing open repair compared with endovascular repair (44.0 vs 19.4 days; P = .04). Four (80%) of five patients who were discharged from the hospital in the open group were placed in skilled nursing facilities, and seven (87.5%) of eight patients discharged in the endovascular group returned home. The median overall survival after hospital discharge was 23.1 months. There were no late aneurysm-related deaths or late deaths related to septic complications.

CONCLUSIONS

Patients with AEFs have limited overall survival. Endovascular therapy offers an alternative to open surgical repair, seems to be associated with decreased perioperative morbidity and mortality and a shorter in-hospital stay, and allows for acceptable survival given the presence of coexisting medical comorbidities. Furthermore, endovascular repair provides a therapeutic option to control bleeding and allow for continued intervention in a stabilized setting.

Anastomotic Pseudoaneurysms: Our Experience with 49 Cases

We investigated the factors implicated in the pathogenesis of anastomotic aneurysm formation and the postoperative course of patients with such a complication. Forty-five patients with 49 anastomotic aneurysms were diagnosed and treated in two vascular surgery departments in Athens, Greece, during an 8-year period. Emergent complications occurred in 15 cases, rupture in 11, and thromboembolic episodes in another four. Preoperative diagnostic workup in the remaining elective cases (n = 34) included color duplex scan, computed tomographic scan, and angiography. All patients underwent operation, and cultures were obtained during the surgical procedures. Histological examination of the host artery wall adjacent to the aneurysm was also performed. Aortobifemoral bypass was the original operation performed in the majority of cases (71%), and the femoral anastomosis was the most frequent site involved (85.7%). Emergent procedures were associated with increased mortality (46.6%), whereas elective operation resulted in high patency rates and no mortality. In an attempt to isolate predisposing factors that contributed to aneurysm formation, we concluded that the etiology was multifactorial in approximately one-third of the cases and degenerative host artery disease was the main cause (40%). Arterial degeneration is the leading cause of anastomotic aneurysm formation, and emergency arterial reconstruction in cases of aneurysm complication is associated with a poor prognosis.

Evaluation of the Effect of Endovascular Options on Infrarenal Abdominal Aortic Aneurysm Repair

Endovascular devices designed to exclude flow to infrarenal abdominal aortic aneurysms (AAA) were approved by the Food and Drug Administration in the United States in 1999. This action allowed widespread use of this technology for AAA exclusion. The purpose of this report is to examine trends for use of these modalities, rates of rupture of AAA, and to compare results of open AAA repair with endovascular repair. Results were collected for all hospitals, except for Veterans Administration hospitals, by a state-wide repository. Data for the years 1996 through 1998 and 2001 through 2002 were evaluated, and data from 1999 through 2000 were excluded because no separate codes were available to distinguish between open and endovascular repair. The information gathered is based on the All Patient Refined Diagnostic Related Group (APR-DRG®; 3M, St. Paul, MN). An average of 718 open, elective AAA was performed between 1996 and 1998. This dropped to 503 open repairs from 2001 to 2002 ( P < 0.005). During that same interval, 308 endovascular elective AAA repairs were performed, therefore the total rate of elective repair increased by 100. The average rate of ruptured AAA repairs from 1996 to 1998 was 121 per year, and this dropped to 89 from 2001 to 2002 ( P < 0.005). The mortality of open AAA repair during the 1996 to 1998 and 2001 to 2002 intervals was unchanged (4.7%). Mortality from endovascular AAA repair between 2001 and 2002 was 1.9 per cent ( P = 0.003). Major morbidity was 14.5 per cent for open, elective AAA repair and 6.3 per cent for endovascular elective repair from 2001 to 2002 ( P < 0.001). These data suggest that the advent of endovascular AAA repair has contributed to a reduction in the rate of ruptured AAA repairs, an increase in total procedures performed, and a significant decrease in perioperative deaths and major complications when compared with open AAA repair.

InterGard silver bifurcated graft: Features and results of a multicenter clinical study

OBJECTIVES

Recent research in vascular surgery has focused on development of infection-resistant prosthetic grafts. This article describes the results of a multicenter study to evaluate safety, patency, and infection rates after implantation of the InterGard Silver bifurcated polyester graft coated with collagen and silver.

METHODS

Between October 2000 and February 2002, 289 consecutive patients were implanted with a collagen and silver acetate-coated polyester bifurcated graft at 16 French vascular surgery centers. Mean patient age was 65.3 +/- 10.9 years. The indication for prosthetic bypass was aortic aneurysm in 160 patients (55.4%) and symptomatic aortoiliac occlusive disease in 129 (44.6%). All but four patients received prophylactic antibiotic therapy. Patency was assessed at 30 days, 1 year, 2 years, and 3 years, primarily by duplex scan.

RESULTS

Two patients (0.7%) died during the first 30 days. Median duration of hospitalization was 11 days. The Kaplan-Meier survival rate at 3 years was 85.7% +/- 4.1%. Primary and secondary patency rates at 3 years were 94.9% +/- 2.6% and 97.5% +/- 1.8%. Thrombectomy was performed successfully in seven patients, and a major amputation was required in two patients with patent grafts. Postoperative complications, including 39 nosocomial infections, were observed in 107 patients (37.0%). Eleven patients presented with 12 wound infections that were classified Szilagyi grade I in eight cases, grade II in two cases, and grade III with graft infection in two cases (0.7%). Among the 149 patients undergoing aortofemoral bypass, eight (5.4%) presented with wound infection, including two graft infections (1.3%). Among the 140 patients undergoing aortoiliac bypass, only three patients (2.1%) presented wound infection and none with graft infection (P = .15). Three (16.7%) of 18 patients who had undergone previous femoral revascularization and eight (3%) of 271 patients without previous femoral revascularization presented with wound infection. This difference was statistically significant (P = .03), with a relative risk of 5.6 (95% confidence interval [CI], 1.6 to 19.5). Five (11.9%) of 42 diabetic patients and six (2.4%) of 247 nondiabetic patients presented with wound infection. This difference was also statistically significant (P = .01), with a relative risk of 3.4 (95% CI, 1.7 to 6.9). Lymphorrhea or lymphocele developed in the groin of 25 patients (8.6%) with negative culture.

CONCLUSION

This multicenter prospective study shows that the InterGard Silver graft is safe with no side effects. The primary patency rate was excellent, and the graft infection rate was low, despite a high incidence of nosocomial infections.

Late reintervention for aortic graft-related events and new aortoiliac disease after open abdominal aortic aneurysm repair in an Australian population

OBJECTIVE

To examine late reintervention rates for aortic graft-related events and new aortoiliac disease after open abdominal aortic aneurysm (AAA) repair in an Australian population.

METHODS

Interrogation of a prospective computerized database identified 1256 consecutive patients (1058 men, 198 women; median age, 70 years; range, 40 to 97 years) who survived open repair of nonruptured (n = 957, group I) and ruptured (n = 299, group II) infrarenal AAA in a single institution between January 1, 1982 and December 31, 2003. Median (range) follow-up was 41 (1 to 261) months for group I and 30 (1 to 243) months for group II.

RESULTS

In group I, 33 patients (3.4%) underwent 38 late reinterventions: 20 patients (2.1%) for aortic graft-related events at a median (range) interval of 36 (1 to 94) months after the index AAA repair, with a 30-day mortality rate of 15%; and 13 patients (1.4%) for new aortoiliac disease at a median (range) interval of 33 (3 to 207) months, with 30-day mortality of 8%. In group II, 15 patients (5%) underwent 16 late reinterventions: 10 patients (3.3%) for aortic graft-related events at a median (range) interval of 5 (2 to 112) months, with a 30-day mortality of 10%; and five patients (1.7%) for new aortoiliac disease at a median (range) interval of 67 (39-105) months, with a 30-day mortality of 40%. There was no significant difference in the late reintervention rate between the groups: group I, 33 (3.4%) of 957 vs group II, 15 (5%) of 299 (P = .23). For all patients, the estimated survival at 1, 3, 5 and 10-years was 90%, 79.4%, 66.4%, and 31.6%, respectively; estimated survival free from reintervention at 1, 3, 5 and 10-years was 98.7%, 97.1%, 95.1%, and 91.9%, respectively.

CONCLUSIONS

These data demonstrate, for the first time, that open AAA repair has excellent long-term durability in an Australian population and the results compare favorably with previous reports from North America and Europe. These data represent an important benchmark for comparison of the results of endovascular AAA repair in this patient population.

Endovascular Stent-Graft Repair as a Late Secondary Procedure After Previous Aortic Grafts

Thoracic and abdominal aortic endovascular procedures as alternatives to aortic reoperations were studied in three different cases. An anastomotic aneurysm after previous thoracic aortic graft for coarctation, a second-stage elephant trunk repair (descending thoracic aortic aneurysm), and a secondary aneurysm proximal to a previous abdominal aortic graft were successfully treated with endovascular stent-grafts. During the follow-up period no lethal events or major aortic or graft-related complications were observed, except a type II endoleak in the anastomotic aortic aneurysm case. An endovascular stent-graft can be safely deployed into a previously implanted vascular graft, avoiding repeat surgery.

Aortic Stent-Graft Infection Following Septic Complications of a Kidney Stone

A 73-year-old man was treated because of a renal pelvis blowout of the left kidney for which he received a nephrostomy catheter without antibiotic prophylaxis. Almost a year previously this patient had undergone endovascular repair of a symptomatic infrarenal abdominal aorta aneurysm. Four weeks after the diagnosis and treatment of the ruptured renal pelvis, a new computed tomography scan and ultrasound-guided fine needle aspiration confirmed the diagnosis of infected aortic stent-graft. An extra-anatomic axillo-uniiliac bypass and graft excision was performed. Two weeks after discharge the patient returned to the hospital with an occlusion of his left renal artery and died of renal failure. This is the first time an infected aortic stent-graft after a renal pelvis blowout has been reported. Although infections of aortic stent-grafts occur rarely, one should be aware of the possibility in aortic stent-graft patients undergoing abdominal procedures without antibiotic prophylaxis.

Repair of Anastomotic Abdominal Aortic Pseudoaneurysm Utilizing Sequential AneuRx Aortic Cuffs in an Overlapping Configuration

Anastomotic aortic pseudoaneurysm is a known late complication following aortic repair and presents a considerable surgical challenge. We herein evaluate the endovascular alternative of using sequential AneuRx aortic cuffs to bridge the degenerative anastomotic pseudoaneurysms as a definitive treatment. Over a 3-year period, six patients with a mean age of 68.7 years (range 58-75) were identified who had proximal anastomotic aortic pseudoaneurysms secondary to previously implanted bifurcated aortic grafts (mean 15, range 12-20 years) following open surgical correction of aortoiliac occlusive disease. Five patients (83%) presented with concomitant palpable femoral anastomotic pseudoaneurysms and one patient (16%) had a pulsatile abdominal mass. All patients had computed tomographic (CT) scans confirming proximal anastomotic pseudoaneuryms without evidence of infection. The mean diameter of the pseudoaneurysms was 5.3 cm (range 4.0-7.0). Five patients were treated with endovascular methods, while one patient was not suitable for endovascular repair due to the diameter of the native aorta as seen on imaging study at the time of the procedure. AneuRx aortic extender cuffs (3.75 cm length) were deployed sequentially in five patients via a femoral approach. Devices were overlapped approximately 1.5 cm in order to achieve total exclusion of the pseudoaneurysms, and all concomitant femoral aneurysms were repaired surgically at the same time. Successful exclusion of the anastomotic pseudoaneurysm was achieved in four patients (80%) using a combination of two or three overlapping aortic cuffs. One patient had a small residual endoleak that had sealed by 1 month, evidenced by follow-up CT. The renal arteries were preserved in all patients. The average estimated blood loss and operative time were 355 +/- 25 cc and 84 +/- 21 min, respectively. The average length of hospital stay was 2.1 days, and there was no mortality or major morbidity. All patients underwent CT scanning surveillance at 6 and 12 months and yearly afterward. There was no evidence of late endoleak, aneurysmal expansion, or device migration during the mean follow-up of 10 months, ranging 6-27 months. Our study demonstrated that utilizing sequential AneuRx aortic cuffs applied in an overlapping configuration is an effective strategy for degenerative aortic anastomotic pseudoaneurysm from previously placed aortic grafts. Additionally, our study suggests this unique endovascular technique is an ideal alternative for creating a customized tube graft in challenging cases, particularly in high-risk patients.

Secondary interventions after endovascular abdominal aortic aneurysm repair

BACKGROUND

One adverse outcome of endovascular abdominal aortic aneurysm (AAA) repair (EVAR) is a significantly increased incidence of secondary interventions (SIs) required compared with traditional open aortic repair. We present a consecutive series of EVARs using a single endograft to identify the incidence and types of SIs performed.

METHODS

From February 1, 2000, to January 31, 2005, we repaired 136 AAAs with the Zenith (Cook, Bloomington, Indiana) endograft. All patients met the same strict anatomic inclusion and exclusion criteria. Follow-up lasted from 1.5 to 61 months (median 36). The indications for SI group A were procedural and technical errors, for group B were aortic morphology, and for group C were device failures.

RESULTS

Twenty-one SIs were required in 17 of 136 patients (12.5%). Three patients required multiple interventions. Nine patients were in group A, four were in group B, and six were in group C. All but 4 patients required SIs for late (>30 days) complications.

CONCLUSIONS

Although it is a viable alternative to open aortic repair, EVAR is associated with a significantly higher rate of SIs. To maintain the efficacy of EVAR, patients must be followed-up in a vigilant graft surveillance protocol for life.

Repair of juxtarenal para-anastomotic aortic aneurysms after previous open repair with fenestrated and branched endovascular stent grafts

Three patients with juxtarenal para-anastomotic aortic aneurysms after previous open abdominal aortic aneurysm repair were treated with custom-designed fenestrated and branched Zenith endovascular stent grafts. Six renal arteries and two superior mesenteric arteries were targeted for incorporation by graft fenestrations and branches. The fenestration/renal ostium interface was secured with balloon-expandable Genesis stents (n = 5) or Jostent stent grafts (n = 1). Completion angiography demonstrated no endoleaks and antegrade perfusion in all target vessels. During follow-up, one patient developed asymptomatic renal artery occlusion and underwent further endovascular intervention for type I distal endoleak. Computed tomography at 12 months demonstrated complete aneurysm exclusion in all patients with antegrade perfusion in the remaining target vessels. Fenestrated and branched endovascular stent grafts may be an acceptable alternative to conventional open repair in this group of patients.

Lifeline registry of endovascular aneurysm repair: Long-term primary outcome measures

PURPOSE

To determine the long-term outcome after endovascular aneurysm repair (EVAR) of infrarenal abdominal aortic aneurysms (AAA).

METHODS

Review the primary outcome measures of patients treated with endovascular grafts (EG) in the Lifeline Registry of EVAR. The registry contains data on 2,664 EG patients and 334 open surgical control (SC) patients collected under four multicenter Investigational Device Exemption (IDE) clinical trials that lead to United States Food and Drug Administration (FDA) approval with mandatory 5-year follow-up. Primary outcome measures include operative mortality, AAA-related death, all-cause mortality, aneurysm rupture, and surgical conversion.

RESULTS

Pooled data from IDE clinical trials revealed that EG patients were 3 years older (73 +/- 8 years) than SC patients (70 +/- 8 years, P < .01) and had significantly more cardiac comorbidities before treatment. However, there was no difference in 30-day operative mortality between EG (1.7%) and SC (1.4%) (P = .72). Both EG and SC were successful in preventing rupture, with freedom from aneurysm rupture in 99.8% of EG and 100% of SC patients at 1 year (P = .51). Freedom from rupture remained at 99% in years 1 to 6 after EG, with no increasing risk of late rupture. There was no significant difference in the AAA-related death rate at 1 year between EG (98.2%) and SC (98.6%) (P = .64). Freedom from AAA-related death remained at 98% in years 1 to 6 after EG, with no increasing risk of late AAA-related death. Kaplan-Meier analysis at 6 years revealed freedom from aneurysm rupture in 99%, freedom from AAA-related death in 98%, and freedom from surgical conversion in 95% of EG patients. There was no difference in survival at 4 years between EG (74%) and SC (71%) (P = .49). Overall EG patient survival at 5 years was 66% and at 6 years was 52%. Women had a higher risk of rupture (2.4%) than men (1.2%) (P = .01) and a higher rate of surgical conversion (8.3%) than men (3.8%) (P < .01) but had the same low AAA-related death rate (3.5%) as men (2.1%) (P = .16) at 5 years. Most secondary interventional procedures (85%) were performed < or =30 days after EVAR. Freedom from secondary intervention was 84% at 1 year and 78% at 5 years.

CONCLUSIONS

Endovascular aneurysm repair using FDA-approved devices is a safe, effective, and durable treatment for anatomically suited patients with infrarenal abdominal aortic aneurysms.

Surgical treatment of atypical aortic coarctation complicating Takayasu's arteritis--experience with 33 cases over 44 years

PURPOSE

This study was conducted to evaluate the long-term outcomes of surgical treatment for atypical aortic coarctation due to Takayasu's arteritis and to elucidate the factors that affected outcome.

METHODS

The outcomes of surgical treatment for atypical aortic coarctation complicating Takayasu's arteritis in 33 consecutive patients over the previous 44 years at our institution were reviewed retrospectively. Preoperatively, 29 patients had coarctation proximal to the renal arteries and hypertension in the upper half of the body. Four hospital deaths occurred, and the remaining 29 patients were followed from 0.5 to 42.0 years (median, 17.9 years). The impacts of several risk factors on survival as well as cardiac and vascular events were analyzed.

RESULTS

Among 27 initial survivors who had hypertension preoperatively, 15 did not show normalization of blood pressure. The overall cumulative survival and event-free survival rate at 20 years were 62.3% and 58.4%, respectively. Serious long-term complications were anastomotic aneurysms, congestive heart failure, cerebrovascular accident, graft deterioration, abdominal aortic aneurysms, and renal failure. Among several risk factors analyzed, only the presence of postoperative hypertension had an effect on event-free survival.

CONCLUSIONS

The long-term survival after surgery for atypical aortic coarctation was satisfactory. However, our study showed that complications associated with cardiovascular system or the operation could occur at any time after surgery; thus, life-long follow-up is mandatory. Further, the absence of normalization of blood pressure after surgery was a poor prognostic factor. Our results demonstrate the need for an intimate preoperative evaluation of renal and carotid artery lesions, which often coexist and may also cause secondary hypertension, to fully manage hypertension by surgery.

Endovascular Repair or Surveillance of Patients with Small AAA

OBJECTIVE

To compare the outcome of patients with small abdominal aortic aneurysms (AAA) treated in a prospective trial of endovascular aneurysm repair (EVAR) to patients randomized to the surveillance arm of the UK Small Aneurysm Trial.

METHOD

All patients with small AAA (< or = 5.5 cm diameter) treated with a stent graft (EVARsmall) in the multicenter AneuRx clinical trial from 1997 to 1999 were reviewed with follow up through 2003. A subgroup of patients (EVARmatch) who met the age (60-76 years) and aneurysm size (4.0-5.5 cm diameter) inclusion criteria of the UK Small Aneurysm Trial were compared to the published results of the surveillance patient cohort (UKsurveil) of the UK Small Aneurysm Trial (NEJM 346:1445, 2002). Endpoints of comparison were aneurysm rupture, fatal aneurysm rupture, operative mortality, aneurysm related death and overall mortality. The total patient years of follow-up for EVAR patients was 1369 years and for UK patients was 3048 years. Statistical comparisons of EVARmatch and UKsurveil patients were made for rates per 100 patient years of follow up (/100 years) to adjust for differences in follow-up time.

RESULTS

The EVARsmall group of 478 patients comprised 40% of the total number of patients treated during the course of the AneuRx clinical trial. The EVARmatch group of 312 patients excluded 151 patients for age < 60 or > 76 years and 15 patients for AAA diameter < 4 cm. With the exception of age, there were no significant differences between EVARsmall and EVARmatch in pre-operative factors or post-operative outcomes. In comparison to the UKsurveil group of 527 patients, the EVARmatch group was slightly older (70 +/- 4 vs. 69 +/- 4 years, p = 0.009), had larger aneurysms (5.0 +/- 0.3 vs. 4.6 +/- 0.4 cm, p < 0.001), fewer women (7 vs. 18%, p < 0.001), and had a higher prevalence of diabetes and hypertension and a lower prevalence of smoking at baseline. Ruptures occurred in 1.6% of EVARmatch patients and 5.1% of UKsurveil patients; this difference was not significant when adjusted for the difference in length of follow up. Fatal aneurysm rupture rate, adjusted for follow up time, was four times higher in UKsurveil (0.8/100 patient years) than in EVARmatch (0.2/100 patient years, p < 0.001); this difference remained significant when adjusted for difference in gender mix. Elective operative mortality rate was significantly lower in EVARmatch (1.9%) than in UKsurveil (5.9%, p < 0.01). Aneurysm-related death rate was two times higher in UKsurveil (1.6/100 patient years) than in EVARmatch (0.8/100 patient years, p = 0.03). All-cause mortality rate was significantly higher in UKsurveil (8.3/100 patient years) than in EVARmatch (6.4/100 patient years, p = 0.02).

CONCLUSIONS

It appears that endovascular repair of small abdominal aortic aneurysms (4.0-5.5 cm) significantly reduces the risk of fatal aneurysm rupture and aneurysm-related death and improves overall patient survival compared to an ultrasound surveillance strategy with selective open surgical repair.

Abdominal aortic aneurysm

Abdominal aortic aneurysms cause 1.3% of all deaths among men aged 65-85 years in developed countries. These aneurysms are typically asymptomatic until the catastrophic event of rupture. Repair of large or symptomatic aneurysms by open surgery or endovascular repair is recommended, whereas repair of small abdominal aortic aneurysms does not provide a significant benefit. Abdominal aortic aneurysm is linked to the degradation of the elastic media of the atheromatous aorta. An inflammatory cell infiltrate, neovascularisation, and production and activation of various proteases and cytokines contribute to the development of this disorder, although the underlying mechanisms are unknown. In this Seminar, we aim to provide an updated review of the pathophysiology, current and new diagnostic procedures, assessment, and treatment of abdominal aortic aneurysm to provide family practitioners with a working knowledge of this disorder.

Complications of major aortic and lower extremity vascular surgery

Atheromatous disease and invasive intervention of the aortoiliac and distal arteries are common. Morbidity and mortality have been reduced through understanding and management of patient risk factors. Complications of this form of treatment affect all organ systems; mortality is most frequently caused by a cardiovascular complication (eg, myocardial infarction). Infection, leading to aortoenteric fistula is a dreaded complication, and paraplegia, though rare, is a devastating outcome. Multiorgan failure and death may result from a systemic inflammatory response syndrome. Vascular surgery for infrainguinal disease also has a significant cardiovascular complication rate. Resulting complications may affect all organs; loss of an extremity may occur. The first part of this article reviews perioperative and postoperative complications of open aortic repair and lower-extremity revascularization and addresses the issue of regional anesthesia for major vascular surgery. The second part reviews endovascular aortic repair (EVAR). EVAR is a new intervention that combines surgery and radiology. Complications of EVAR are similar to open repair, but early results suggest they may be less frequent. New technology leads to new complications; endoleaks, migration of the endoprosthesis, and surgical conversion are unique to EVAR. The benefits of EVAR may be less blood loss, shorter hospitalization, and less cardiovascular stress; the risks may be aneurysm recurrence, prolonged surveillance and repeated secondary procedures. The development of EVAR, the complications, and the anesthesia-related concerns of EVAR, including its use in management of acute abdominal aortic aneurysm are reviewed.

Optimal follow-up strategies after aorto-iliac prosthetic reconstruction: a decision analysis and cost-effectiveness analysis

OBJECTIVE

The primary aim of ultrasound follow-up after aorto-iliac prosthetic reconstruction is to correct false aneurysms before rupture occurs. We investigated whether follow-up improves the life expectancy of patients and sought to identify the most cost-effective follow-up strategy.

DESIGN OF THE STUDY

A Monte Carlo Markov decision model was constructed. The occurrence of false aneurysms was modelled as a time-dependent process for each anastomotic site, based on published series. Using this model, the impact of various follow-up strategies was investigated for three types of prostheses, aorto-distal tube, aorto-bi-iliac, and aorto-bi-femoral prostheses. Main outcome measures were discounted quality adjusted life years (dQALYs), discounted costs, and (discounted) cost-effectiveness (CE) ratios.

RESULTS

Follow-up of patients with aorto-distal tube and aorto-bifemoral prostheses did not result in an improvement life expectancy and was not cost-effective, QALYs 7.53 and 7.62 years, respectively. The results for aorto-distal tube and aorto-bifemoral prostheses were not sensitive to any variation in the model parameters. In the base case analysis, the life expectancy of patients with aorto-bi-iliac prostheses was 7.50 QALYs (95% confidence interval 7.46-7.54) whether or not they underwent routine follow-up. However, patients aged 54 years or younger gained 0.11 QALYs with annual follow-up (p<0.05). The most cost-effective strategy was annual follow-up that starts 10 years after the initial operation, and continues up to 30 years after surgery (4600 Euro; CE ratio 21,000 Euro per QALY). When perioperative mortality of elective reconstruction of false aneurysms is 2% or lower (e.g. when endovascular treatment is used), a small improvement is observed (7.56 vs. 7.50 QALYs; p<0.05; CE ratio 35,000 Euro per QALY).

CONCLUSIONS

Annual follow-up of aorto-bi-iliac prostheses should be restricted to patients aged 54 or younger and not start before 10 years after surgery. The same strategy can only be considered for older patients if mortality for secondary intervention is lower than 2%. Since patients with aorto-distal tube and aorto-bi-femoral prostheses do not benefit from follow-up for the detection of false aneurysms, this practice should be discouraged in these patient groups.

Late problems at the proximal aortic neck: Migration and dilation

Migration is a late-term complication of endovascular aneurysm repair (EVAR) evidenced by downward slippage of the endograft. The etiology of migration may be inherent to problems with endograft fixation, although aortic neck dilation may also play a role. Devices with active fixation (ie, hooks and barbs) possess an additional mechanism of fixation and may better resist migration. Aortic neck dilation after EVAR is significant in a subset of patients and may be related to neck degeneration. Excessive oversizing of endografts may contribute to dilation and migration and is, therefore, not recommended. Migration should be treated when the overlap between the endograft and aortic neck is less than 10 mm or when associated with clinically significant events such as type I endoleak or aneurysm expansion. Failure to treat migration could lead to repressurization and subsequent rupture of the aneurysm.

Endovascular repair of paraanastomotic aneurysms after previous open aortic prosthetic reconstruction

The aim of this study was to evaluate the effectiveness of endovascular repair of anastomotic and true aortic and iliac aneurysms occurring after prior polyester graft repair for abdominal aortic aneurysms (AAA) or aortoiliac obstructive disease. Between July 1999 and January 2003, 14 patients underwent endovascular treatment of aortic pseudoaneurysms (n = 6) or iliac aneurysms (2 patients with pseudoaneurysms and 6 patients with true aneurysms) occurring 4 to 18.4 years (mean, 8.8 years) after open aortic surgery. No patient had symptoms or positive parameters for infection of the original polyester graft. Eleven patients, including one patient with both a proximal anastomotic and a true iliac aneurysm, were treated with AneuRx (n = 8), Talent (n = 2), or Quantum LP (n = 1) bifurcated stent grafts. Three patients with an infrarenal anastomotic pseudoaneurysm were treated with a tube stent graft (Talent [n = 2] and AneuRx [n = 1]). Endovascular stent grafts were successfully inserted in all patients. Procedure-related complications or death was not seen. During a median follow-up of 12 months (range, 3-40) all anastomotic and/or true aneurysms treated with bifurcated stent grafts maintained excluded. However, two out of three patients, treated with a tube graft for proximal aneurysm exclusion, were converted. In both patients the tube stent graft did not migrate from the level of the renal arteries but fixation failed between the stent graft and the previous polyester graft, creating endotension in the thrombus of the aneurysm sac. In one of these patients the old anastomotic aneurysm ruptured 16 months after stent graft placement and the patient died 1 day after conversion because of mesenterial ischemia. At 1 year follow-up the second patient was converted successfully after enlargement of his anastomotic aneurysm due to similar disconnection between the stent graft and the polyester graft. From this experience with endovascular stent grafts, we conclude that these can be used successfully to exclude anastomotic or true aneurysms after open aortic surgery. Exclusion of aneurysms at the proximal anastomosis with tube stent grafts is apparently not durable because of the insecure distal fixation in polyester grafts. Endovascular repair with bifurcated stent grafts, however, seems to be effective at midterm follow-up.

Endovascular Abdominal Aortic Aneurysm Repair: Does Gender Matter?

Substantial differences across genders have been documented for the natural history and clinical course of cardiovascular diseases. This study's objective is to compare preoperative characteristics, intraoperative events, and postoperative outcomes in men and women undergoing endovascular abdominal aortic aneurysm repair (EVAR). We hypothesized that despite gender anatomic specificities, EVAR may achieve similar results across genders. We included 241 consecutive patients who underwent elective EVAR at our institution from December 1996 through May 2003. Demographic variables and comorbidities were collected by chart review, and intraoperative events were from surgical notes. Baseline anatomic characteristics were evaluated on the last preoperative computed tomography (CT) scan. Radiologic outcomes were evaluated on all postoperative CT scans, and clinical follow-up information was abstracted from charts. Women constituted 12% (n = 29) of our cohort and were older than men (79.9 vs. 74.9 years, p = 0.0003). When compared to men, they had aneurysms with similar diameter (54.1 vs. 55.5 mm, p = 0.491) but narrower (23.1 vs 25.5 mm, p < 0.0001) and shorter (18.9 vs. 30.4 mm, p < 0.0001) proximal necks. Female iliac arteries were narrower (9.6 vs. 11.4 mm, p < 0.0001), with higher calcification scores (2.5 vs. 2.3, p = 0.047) but lower tortuosity indexes (1.2 vs. 1.3, p = 0.0001). Additional access maneuvers were more frequent in women: iliac access angioplasty (31% vs. 10.9%, = p = 0.007), uni-iliac conversion (13.8% vs. 1.4%, p = 0.005), and iliac "chimney" conduit (12.1% vs. 1.2%, p = 0.0001). There was a trend toward longer fluoroscopy time in women (34.6 vs. 26.9 min, p = 0.056). The following postoperative outcomes at 24 months were similar in women and men: freedom from endoleak (63.4% vs. 72.7%, p = 0.74), reintervention rate (28% vs. 24.5%, p = 0.878), aneurysm shrinkage (24.3% vs. 68.7%, p = 0.199), aneurysm expansion (0% vs. 3%, p = 0.213), and survival (92.9% vs. 84.3%, p = 0.341). There was a trend toward higher rates of neck dilation relative to preoperative diameter in women (48.5% vs. 16% at 12 months, p = 0.059) and toward lower limb patency rates in men (100% vs. 92.8%, p = 0.098). In sum, women have shorter proximal necks and smaller and more calcified iliac arteries, which increases the necessity of access-related additional maneuvers. Despite being older and having a less favorable anatomy, women can expect similar technical and clinical outcomes after EVAR.

Initial management and outcome of aortic endograft limb occlusion

OBJECTIVE

The purpose of this study was to determine the differences in outcome related to initial management of aortic endograft limb occlusion (ELO).

METHODS

During a 7-year period, 823 endovascular aneurysm repairs (EVARs) resulted in 25 ELOs in 22 patients. The initial management and outcome of these ELOs were reviewed. Median follow-up after ELO was 24.2 +/- 16.8 months.

RESULTS

Initial EVARs included both unsupported unibody (n = 5) and supported modular (n = 17) devices. ELO was significantly more common in the unsupported unibody graft design (P <.024) and with extension of the graft limb to the external iliac artery (P <.001). ELO was managed with an endovascular approach (EVA), including some combination of mechanical thrombectomy (n = 8), angioplasty with or without stenting (n = 8), and thrombolysis (n = 2) in 12 patients and bypass procedures (femoral-femoral bypass, n = 11; axillofemoral bypass, n = 1; and aortofemoral bypass, n = 1) in 13. At 12-month follow-up, freedom from secondary procedures with EVA was 80.2 +/- 17.7% versus 53.2 +/-17.1% with extra-anatomic bypass (EB) (P = NS). Secondary patency was 100% with EVA and 80.6 +/- 14.4% with EB (P = NS). Of the 12 EVAs, there was 1 (8.3%) perioperative mortality with EVA and none with EB. EB failure was directly attributed to donor limb occlusion in 4 of 6 EVAs (67%), and when this occurred it resulted in bilateral lower extremity ischemia. Amputation was required in 2 of 12 (16.7%) EBs versus none of the 12 EVAs (P = NS). EVA never resulted in graft dislodgement or endoleak but did identify an underlying treatable cause in 8 of 12 (67%).

CONCLUSION

Both EVA and EB are acceptable management strategies for ELO. The potential risk of graft dislodgement was not observed with an EVA. If EB is employed, assessment of the donor limb and treatment of any underlying lesions is advisable in an attempt to minimize future donor limb occlusion.

Thoracovisceral segment aneurysm repair after previous infrarenal abdominal aortic aneurysm surgery

OBJECTIVE

Repair of thoracovisceral aortic aneurysms (TVAA) after previous open repair of an infrarenal abdominal aortic aneurysm (AAA) poses significant challenges. We sought to better characterize such recurrent aneurysms and to evaluate their operative outcome.

METHODS

We reviewed the records and radiographs of 49 patients who underwent repair of TVAAs between 1988 and 2002 after previous repair of an AAA. Visceral artery reconstructions were completed with combinations of beveled anastomoses, inclusion patches, and side arm grafts. In 14 patients visceral endarterectomy was required to treat associated occlusive disease. Sixteen patients had cerebrospinal fluid drainage, and 10 patients had distal perfusion during cross-clamping.

RESULTS

Patient mean age was 72 years, and 80% were men. Fifty-one percent of patients had symptomatic disease, and average TVAA diameter was 6.2 cm. Mean time between AAA and TVAA repair was 77 months. Twenty-six percent of aneurysms were restricted to the lower visceral aortic segment, 35% extended to the diaphragm, another 35% extended to the distal or middle thoracic aorta, and 4% involved the entire remaining visceral and thoracic aorta. The 30-day operative mortality rate was 4.1% in patients with nonruptured aneurysms and 50% in patients with ruptured aneurysms, for an overall mortality rate of 8.2%. Fifteen patients (30.6%) had major morbidity, including paresis in two patients and dialysis-dependent renal failure in five patients. At late follow-up, three patients required further aortic operations to treat additional aneurysms, and four patients had fatal aortic ruptures. Two-year and 5-year cumulative survival rates were 61% (+/-7.5%) and 37% (+/-7.8%), respectively. At univariate analysis, operative blood loss was the sole significant predictor of major morbidity (P <.023), and rupture (P <.030, P <.0001) and aneurysm extent (P <.0007, P <.0001) correlated with both operative death and long-term survival. Only aneurysm extent (P <.010, relative risk 37.3) remained a significant predictor of long-term survival at multivariate analysis.

CONCLUSION

Elective repair of TVAAs after previous AAA repair can be performed with an acceptable level of operative mortality, though with considerable operative morbidity. Limited long-term survival mandates careful patient selection, and the high mortality associated with ruptured TVAA underscores the need for post-AAA surveillance.

Zenith AAA endovascular graft: intermediate-term results of the US multicenter trial

PURPOSE

The intent of this study was to assess the safety and effectiveness of the Zenith AAA Endovascular Graft compared with conventional aneurysm repair.

MATERIAL AND METHODS

The study was conducted in a prospective, multicenter, nonrandomized, concurrent control manner. Physiologically similar patients with infrarenal abdominal aortic aneurysms (AAAs) underwent either open surgery or repair with the Zenith AAA Endovascular Graft. Separate analyses of physiologically challenged patients were performed. Follow-up was conducted at hospital discharge and at 1, 6, and 12 months (endovascular repair group) or 1 and 12 months (open surgical repair group). Evaluation included computed tomography, abdominal radiography, laboratory tests, and physical examination. Mortality (AAA-related and overall), morbidity, in-hospital recovery, renal function, and secondary interventions were assessed. Patients in the endovascular repair group were evaluated for change in aneurysm size, endoleak, graft migration, conversion, rupture, and device integrity. Statistical analyses were performed with the Kaplan-Meier method, Blackwelder test, propensity score assessment, two-sample t test, Yates-corrected Pearson chi(2) test, and Fisher exact test.

RESULTS

Conventional open surgery was used in 80 patients, and 200 patients underwent repair with the Zenith AAA Endovascular Graft. Technical success was accomplished in 98.8% of patients in the open repair group and 99.5% in the endovascular repair group. Patients in the endovascular repair group had fewer significant adverse events within 30 days (80% vs 57%; P <.001). All-cause mortality was similar (endovascular, 3.5%; open surgery, 3.8%). Aneurysm-related mortality was higher with conventional surgery at 12 months (3.8% vs 0.5%; P =.04). In-hospital recovery and procedural measures were better for endovascular repair in all categories (P <.001). The incidence of endoleak was 17% at 30 days, 7.4% at 12 months, and 5.4% at 24 months. Aneurysm shrinkage (>5 mm) was noted in more than two thirds of patients at 12 months and three fourths of patients at 24 months. Renal dysfunction rate did not differ between groups. Migration (>5 mm) was detected in four (2%) patients through 12 months; none was greater than 10 mm or associated with adverse events through 24 months. Three conversions were performed within 12 months, one because of aneurysm rupture. Secondary procedures were more common in the endovascular group (11% vs 2.5%; P =.03). In total, 351 patients had endografts implanted, and 6 patients were noted to have barb separations through 12-month follow-up. No stent fractures were noted.

CONCLUSIONS

The Zenith AAA Endovascular Graft is safe and effective for treatment of infrarenal AAAs. The high likelihood of decrease in aneurysm size provides evidence that treatment of aneurysms with this device reverses the natural history of aneurysmal disease. The importance of long-term follow-up is underscored by the small but defined incidence of barb separation and the potential for unforeseen failure modes.

Single-stage treatment of aortic coarctation and aortic valve disease

Surgical management of thoracic aortic coarctation associated with severe aortic valve disease is difficult in most cases. As staged procedures are associated with a higher rate of morbidity and mortality, simultaneous operative management of both lesions is desirable. From 1997 to 2001, 9 patients (8 males and 1 female with a mean age of 30.1 +/- 10.4 years) with this condition underwent simultaneous ascending aorta-infrarenal abdominal aorta bypass graft and aortic valve replacement. One patient died from failure of the extracorporeal circulation during the operation. Another patient suffered from partial intestinal obstruction in the early postoperative period but was successfully treated. The underlying pathology was successfully corrected in the 8 surviving patients, whose blood pressure in the upper limbs was reduced while that in the lower limbs rose. Being easier to manage, the single-stage approach with extraanatomic bypass is safe and effective for managing this aortic complication.

Diameter of abdominal aortic aneurysm and outcome of endovascular aneurysm repair: does size matter? A report from EUROSTAR

OBJECTIVES

This study was undertaken to determine the effect of the preoperative diameter of abdominal aortic aneurysms on the midterm outcome after endovascular abdominal aneurysm repair (EVAR).

METHOD

The data for 4392 patients who had undergone EVAR were analyzed. Patients were enrolled over 6 years to June 2002 in the EUROSTAR database. Outcomes were compared between three groups defined by the preoperative diameter of the aneurysm: group A (n = 1962), 4.0 to 5.4 cm; group B (n = 1528), 5.5 to 6.4 cm; and group C (n = 902), 6.5 cm or larger. Patient characteristics, details of aortoiliac anatomy, operative procedures, old or current device generation, and postoperative complications in the three patient groups were compared. Outcome events included aneurysm-related death, unrelated death, conversion, and post-EVAR rupture of the aneurysm. Life table analysis and log-rank tests were used to compare outcome in the three study groups. Multivariate Cox models were used to determine whether baseline and follow-up variables were independently associated with adverse outcome events.

RESULTS

Patients in group C were significantly older than patients in groups A and B (73 years vs 70 and 72 years, respectively; P =.003 - P <.0001 for different group comparisons), and more frequently were at higher operative risk (American Society of Anesthesiologists classification >or=3; 63% vs 48% and 54%; P =.0002-P <.0001). Device-related (type I) endoleaks were more frequently observed at early postoperative arteriography in group C compared with groups A and B (9.9% vs 3.7% and 6.8%; P =.01-P <.0001). Postoperatively systemic complications were more frequently present in group C (17.4% vs 12.0% in group A and 12.6% in group B; P <.0001 and.001). The first-month mortality was approximately twice as high in group C compared with the other groups combined (4.1% vs 2.1%; P <.0001). Late rupture was most frequent in group C. Follow-up results at midterm were less favorable in groups C and B compared with group A (freedom from rupture, 90%, 98%, and 98% at 4 years in groups C, B, and A, respectively; P <.0001 for group C vs groups A and B). Aneurysm-related death was highest in group C (88% freedom at 4 years, compared with 95% in group B and 97% in A; P =.001 and P <.0001, respectively; group B vs A, P =.004). The annual rate of aneurysm-related death in group C was 1% in the first 3 years, but accelerated to 8.0% in the fourth year. Incidence of unrelated death also was higher in groups C and B than in group A (76% and 82% freedom at 4 years vs 87%; P <.0001 for both comparisons). Ratio of aneurysm-related to unrelated death was 23%, 21%, and 50% in groups A, B, and C, respectively. Cox models demonstrated that the correlation between large aneurysms (group C) and all assessed outcome events was independent and highly significant. Older generation devices had an independent association with aneurysm-related and unrelated deaths (P =.02 and P =.04, respectively). However, this correlation was less strong than large aneurysm diameter (P =.0001 and P =.0009, respectively).

CONCLUSIONS

The midterm outcome of large aneurysms after EVAR was associated with increased rates of aneurysm-related death, unrelated death, and rupture. Reports of EVAR should stratify their outcomes according to the diameter of the aneurysm. Large aneurysms need a more rigorous post-EVAR surveillance schedule than do smaller aneurysms. In small aneurysms EVAR was associated with excellent outcome. This finding may justify reappraisal of currently accepted management strategies.

Aneurysm enlargement following endovascular aneurysm repair: AneuRx clinical trial

OBJECTIVE

The purpose of this study was to determine the incidence and significance of aneurysm enlargement, with or without treatment, in relation to the primary end points of rupture, surgical conversion, aneurysm-related death, and survival following endovascular repair.

METHOD

Aneurysm (AAA) size changes and clinical outcome of all patients treated from 1997 through 1998 during the Phase II AneuRx multicenter clinical trial of endovascular AAA repair were reviewed. Aneurysm dimensions and the presence or absence of endoleak were determined by an independent core laboratory, with enlargement or shrinkage defined as a diameter change of 5 mm or more compared with baseline.

RESULTS

Among 383 patients (89% men, 11% women, age 73 +/- 9 years), with a mean device implant time of 36 +/- 11 months (median = 39 months), aneurysm diameter decreased from 5.7 +/- 1.0 at baseline to 5.2 +/- 1.0 at 3 years (P =.0001). A total of 46 patients (12%) experienced AAA enlargement, 199 patients (52%) had no change in AAA diameter, and 138 patients (36%) had a decrease in AAA diameter of 5 mm or more. Significant risk factors for enlargement included age (enlargement patients were 4 years older on average than patients with aneurysms that decreased in size; P =.002) and the presence of an endoleak (P <.001). Among patients with endoleak at any time, 17% had aneurysm enlargement, whereas only 2% of patients without endoleak had aneurysm enlargement (P <.001). Patients with enlargement were more likely to undergo secondary endovascular procedures and surgical conversions (P <.001). Twenty patients (43%) with enlargement underwent treatment, and 26 patients were untreated. There were two deaths following elective surgical conversion and one death in a patient with untreated enlargement and a type I endoleak. Three aneurysms ruptured: one with enlargement, one with no change, and one with a decrease in aneurysm size; all three aneurysms were larger than 6.5 cm. Kaplan-Meier analysis showed that freedom from rupture at 3 years was 98% with enlargement, 99% with no change, and 99% with decrease in AAA size (log-rank test, not significant). Freedom from AAA death at 3 years was 93% in patients with enlargement, 99% in no increase, and 99% in decrease (P =.005). Survival at 3 years was 86% with increase, 82% with no change, and 93% with decrease (P =.02).

CONCLUSIONS

Aneurysm enlargement following endovascular repair was not associated with an increased risk of aneurysm rupture or decrease in patient survival during a 3-year observation period. Aneurysm size rather than enlargement may be a more meaningful predictor of rupture. Close follow-up and a high re-intervention rate (43%) may account for the low risk of rupture in patients with enlargement. The long-term significance of aneurysm enlargement following endovascular repair remains to be determined.

Predictors of development of anastomotic femoral pseudoaneurysms after aortobifemoral reconstruction for abdominal aortic aneurysm

BACKGROUND

The pathogenesis of anastomotic femoral pseudoaneurysms (AFPs) is still unclear. We have performed this long-term retrospective study of patients who underwent aortobifemoral reconstruction for abdominal aortic aneurysm (AAA) in order to better establish the long-term rate of AFP and to identify the predictors of its late occurrence.

METHODS

The long-term outcome of 178 patients who underwent and survived aortobifemoral reconstruction for infrarenal AAA was reviewed.

RESULTS

During a median follow-up of 5.2 years, 28 AFPs developed in 19 patients. Six AFPs were recurrent. The mean linearized rate of AFPs was 1.88% per year. At 15 years, the survival-freedom rate from AFPs was 60%, and from repair of AFPs it was 62%. The survival-freedom rate from AFP was significantly poorer in patients with chronic obstructive pulmonary disease (P = 0.017; at 10 years: 64.3% versus 92.3%), hyperlipidemia (P = 0.0056; at 10 years: 59.2% versus 87.5%), current smoking (P <0.0001; at 10 years: 65.8% versus 94.5%), and postoperative inguinal wound infection (P <0.0001; at 10 years: 42.8% versus 86.8%). Multivariate analysis showed that chronic obstructive pulmonary disease (relative risk [RR]: 3.05, 95% confidence interval [CI]: 1.04 to 8.95), current smoking (RR: 5.38, 95% CI: 1.62 to 17.90), and postoperative inguinal wound infection (RR: 9.04, 95% CI: 2.76 to 29.96) were significantly associated with the development of AFPs. The linearized rate of AFPs was significantly higher only among current smokers (P <0.0001, 4.4% versus 0.8% per year) and among those who had inguinal wound infection (P = 0.001, 9.2% versus 1.5% per year).

CONCLUSIONS

Current smoking and inguinal wound infection may contribute to the development of AFP after aortobifemoral reconstruction for AAA, likely by affecting reparative connective tissue mechanisms at the anastomotic site.

Use of abdominal aortic endovascular prostheses in France from 1999 to 2001

BACKGROUND

Since the introduction of endovascular repair (EVR) for infrarenal abdominal aortic aneurysm (AAA), clinical evaluation has been under way in many countries throughout the world. The main purpose of this retrospective study was to determine outcome of EVR with aortic endovascular prostheses (AEPs) and to evaluate the extent to which French practitioners have complied with regulatory and clinical guidelines for the use of these trial devices.

METHODS

This retrospective study was conducted by the French National Health Insurance Fund for Salaried Workers. Data were compiled on EVR procedures performed at health care institutions all over mainland France between June 1999 and May 2001.

RESULTS

A total of 1012 AEPs were deployed for AAA repair in France during the study period. Only 151 (14.9%) of these EVR procedures were carried out within an approved investigational setting with informed patient consent. Only 149 of the 861 patients (17.3%, 95% confidence interval [CI], 14.9 to 19.9%) who underwent endovascular repair in noninvestigational settings signed informed consent forms. In 452 cases (46.5%), the diameter of the AAA was 50 mm or less. Complete outcome data for the first year were available for 891 patients (88%). Complications occurred in 177 of these patients (19.9%, 95% CI, 17.3 to 22.6%). There were a total of 47 deaths (5.3%, 95% CI, 3.9 to 6.9%), including 27 during the first 30 postoperative days. Other major events during the first year after AEP implantation were ruptured AAA in 5 patients, conversion to open operation in 15, and additional endovascular treatment in 52. Data on clinical surveillance were available for 987 patients (97.5%) with a mean follow-up of 345 days. Only 294 patients (29.8%, 95% CI, 27.0 to 32.7%) underwent complete imaging within the first month after AEP implantation. A total of 184 patients (18.6%, 95% CI, 16.3 to 21.2%) received no surveillance at all.

CONCLUSION

This study shows the need for improvement in the clinical evaluation of new devices and medical technologies in France. Study findings also confirm the significant incidence of adverse outcomes and necessity for routine surveillance after EVR of AAA with AEP. However, risk/benefit analysis is difficult because most procedures were not carried out within a proper investigational context.

Endovascular stent graft repair of abdominal and thoracic aortic aneurysms: a ten-year experience with 817 patients

OBJECTIVE

On November 23, 1992, the first endovascular stent graft (ESG) repair of an aortic aneurysm was performed in North America. Following the treatment of this patient, we have continued to evaluate ESG over the past 10 years in the treatment of 817 patients.

SUMMARY AND BACKGROUND DATA

Abdominal (AAA) or thoracic (TAA) aortic aneurysms are a significant health concern traditionally treated by open surgical repair. ESG therapy may offer protection from aneurysm rupture with a reduction in procedure morbidity and mortality.

METHODS

Over a 10-year period, 817 patients were treated with ESGs for AAA (723) or TAA (94). Patients received 1 of 12 different stent graft devices. Technical and clinical success of ESGs was reviewed, and the incidence of procedure-related complications was analyzed.

RESULTS

The mean age was 74.3 years (range, 25-95 years); 678 patients (83%) were men; 86% had 2 or more comorbid medical illnesses, 67% of which included coronary artery disease. Technical success, on an intent-to-treat basis was achieved in 93.8% of patients. Primary clinical success, which included freedom from aneurysm-related death, type I or III endoleak, graft infection or thrombosis, rupture, or conversion to open repair was 65 +/- 6% at 8 years. Of great importance, freedom from aneurysm rupture after ESG insertion was 98 +/- 1% at 9 years. There was a 2.3% incidence of perioperative mortality. One hundred seventy five patients died of causes not related to their aneurysm during a mean follow-up of 15.4 months.

CONCLUSIONS

Stent graft therapy for aortic aneurysms is a valuable alternative to open aortic repair, especially in older sicker patients with large aneurysms. Continued device improvements coupled with an enhanced understanding of the important role of aortic pathology in determining therapeutic success will eventually permit ESGs to be a more durable treatment of aortic aneurysms.

In situ revascularization with silver-coated polyester grafts to treat aortic infection: early and midterm results

PURPOSE

In this prospective study we analyzed the immediate and midterm outcome in patients with abdominal aorta infection (mycotic aneurysm, prosthetic graft infection) managed by excision of the aneurysm or the infected vascular prosthesis and in situ replacement with a silver-coated polyester prosthesis.

METHODS

From January 2000 to December 2001, 27 consecutive patients (25 men, 2 women; mean age, 69 years) with an abdominal aortic infection were entered in the study at seven participating centers. Infection was managed with either total (n = 18) or partial (n = 6) excision of the infected aorta and in situ reconstruction with an InterGard Silver (IGS) collagen and silver acetate-coated polyester graft. Assessment of outcome was based on survival, limb salvage, persistent or recurrent infection, and prosthetic graft patency.

RESULTS

Twenty-four patients had prosthetic graft infections, graft-duodenal fistula in 12 and graft-colonic fistula in 1; and the remaining 3 patients had primary aortic infections. Most organisms cultured were of low virulence. The IGS prosthesis was placed emergently in 11 patients (41%). Mean follow-up was 16.5 months (range, 3-30 months). Perioperative mortality was 15%; all four patients who died had a prosthetic graft infection. Actuarial survival at 24 months was 85%. No major amputations were noted in this series. Recurrent infection developed in only one patient (3.7%). Postoperative antibiotic therapy did not exceed 3 months, except in one patient. No incidence of prosthetic graft thrombosis was noted during follow-up.

CONCLUSION

Preliminary results in this small series demonstrate favorable outcome with IGS grafts used to treat infection in abdominal aortic grafts and aneurysms caused by organisms with low virulence. Larger series and longer follow-up will be required to compare the role of IGS grafts with other treatment options in infected fields.

Graft-preserving treatment for vascular graft infected with Staphylococcus aureus with antibiotic-releasing porous apatite ceramic in the rabbit

OBJECTIVE

This study was undertaken to investigate whether infection of a vascular graft with Staphylococcus aureus can be treated in situ by applying antibiotic-loaded porous apatite ceramic, in a rabbit model.

METHODS

Teicoplanin (TEIC) was loaded onto a beta-tricalcium phosphate (TCP) block, a type of porous apatite ceramic. The activity of TEIC released from the antibiotic-loaded TCP block was examined in vivo. A vascular graft was patched onto the abdominal aorta in 24 rabbits, and S aureus was applied directly on it. Seven days postoperatively, each rabbit underwent repeat laparotomy, and retroperitoneal abscess around the prosthetic vascular patch was debrided. Animals were divided into four groups of 6 rabbits each. In group 1 only debridement was carried out. In groups 2 and 3, solution containing 40 or 60 mg of TEIC, respectively, was applied to the prosthetic vascular patch. In group 4, an antibiotic-loaded TCP block (63 +/- 6.6 mg of TEIC) was placed around the graft. Three weeks after the second operation, the graft, the tissue around it, and arterial blood were collected and cultured.

RESULTS

TEIC activity was maintained for 28 days in vivo. In group 1, bacterial cultures of the prosthetic vascular graft and the tissue around it were positive in 5 animals and negative in 1 animal (infection rate, 83%). In both groups 2 and 3, cultures were positive in 3 animals and negative in 3 animals (infection rate, 50%). In group 4, cultures were negative in all animals (infection rate, 0%). Blood cultures were negative in all animals. Infection rate in group 4 was significantly lower than that in group 1 (P =.03), and was also lower than that in groups 2 and 3, but the difference was not significant.

CONCLUSIONS

Use of slow-release antibiotic loaded onto a TCP block, along with debridement, may control infection in vascular grafts in situ, averting the necessity to remove the graft.