Improved outcomes with endovascular stent grafts for thoracic aorta transections.

OBJECTIVE: To retrospectively assess the outcome of endovascular stent-graft implantation for thoracic aortic transections (ETAT). DESIGN: Retrospective review. METHODS: 16 patients median age 30 years, treated between May 2000 and April 2007. Median injury severity score was 33 (range 29 to 66) in 14 acute patients; 2 patients had thoracic pseudoaneurysms. The Cook-Zenith endograft was used in eight patients, Medtronic-Talent (6) and Gore-Excluder (2). Average procedure time was 90 minutes, blood loss 100 (range 40 to 3000) mls, screening time 10.8 (range 5.9 to 22.6) minutes, and contrast dose was 195 (range 60 to 400) mls. RESULTS: Graft deployment was successful in all cases. There was one death within 30 days. The left subclavian artery was completely covered in one case, and partially in three. Two patients had Type I endoleak, and one delayed Type II endoleak. One patient had iatrogenic right coronary artery dissection. Two patients developed difficult to treat hypertension, and one acute renal failure. CONCLUSION: Endovascular intervention is a safe and effective treatment for aortic transection in multiple trauma patients. ETAT reduces the major morbidity and mortality associated with open repair in multiple trauma patients. The majority of these patients are young and long-term follow up is necessary to assess graft durability.

Endovascular popliteal aneurysm repair: are the results comparable to open surgery?

INTRODUCTION: The aim of this study was to review our experience of popliteal aneurysms using endovascular techniques. METHODS: Thirty popliteal aneurysms in 25 patients were treated over an 11-year period. Median aneurysm diameter was 26 (16-48) mm. Five were symptomatic and 25 asymptomatic. Patients were treated with the Haemobahn/Viabahn stent-graft (26), Passager (two), Aneurx (one), and PTFE homemade device (one). Data were assessed using life table analysis, and expressed as cumulative patency rates and standard error (SE). RESULTS: Median follow-up was 24 (range 1-95) months. Primary patency was 92.9% (SE 4.5%), 84.7% (SE 6.8%), 80% (SE 8.2%), 74.5% (SE 9.4%) and 74.5% (11.3%) at 1, 6, 12, 24 and 36 months, respectively. Cumulative secondary patency was 96.5% (SE 3.3%), 88.7% (SE 6.0%), 88.7% (SE 8.6%), 83.2% (SE 8.0%) and 83.2% (SE 9.8%) at 1, 6, 12, 24 and 36 months, respectively. CONCLUSION: Endovascular treatment of popliteal aneurysms in this series achieved patency rates similar to open surgery. Aneurysm repair was performed without peroperative deaths and the risks associated with open surgery.

Complications of aortic endografting.

Endovascular repair of abdominal aortic aneurysm has been shown to have a significantly lower perioperative mortality rate compared with open repair. It has been a blessing for patients at high risk who were previously denied treatment for their aortic aneurysms. It does, however, have a substantial need for re-intervention for complications. Many of these complications including endoleak, endotension, migration, post implant syndrome and conversion to open repair are unique to endovascular aneurysm repair. Others including injury to the iliac arteries, graft limb thromboses and structural failure of prostheses occur with greater frequency in endovascular repair compared with open repair. It is important, therefore, for vascular surgeons to be aware of these complications including their prevention and appropriate that patients are informed of their incidence. This review discusses the local and vascular complications of endovascular repair of abdominal aortic aneurysm with an emphasis on newer aspects.

Endotension. A review of current views on pathophysiology and treatment.

Most aneurysms shrink after successful endovascular repair. It has been observed, however, that some aneurysms continue to enlarge despite apparent exclusion of the sac by an endograft device. Unexplained abdominal aortic aneurysm (AAA) enlargement in these circumstances appears to be associated with high pressures inside the sac, and the phenomenon has been termed endotension. This paper reviews current theories and experimental evidence regarding the possible mechanisms of causation of endotension, and early experiences with treatment.

Endovascular repair of abdominal aortic aneurysm in the multifocal atherosclerotic patient.

One of the major problems of treating aortic aneurysms has been the multifocal nature of atherosclerotic disease. Co-existing cardiovascular disease in the majority of patients together with chronic obstructive airways disease, renal impairment and hostile abdomen in some, has resulted in 1/3 of patients presenting with aortic aneurysms being regarded as high risk and unfit for open repair. Endovascular repair of aortic aneurysm therefore has much to recommend it since it avoids the need for laparatomy, cross clamping of the aorta and the obligatory blood loss associated with opening of the sac. Between May 1992 and March 2003 we have used the endovascular method to repair abdominal aortic aneurysms (AAA) in 583 patients. Successful repair was achieved in 563 patients (96%). The remaining 20 patients required primary conversion to open repair at the original operation. The 30-day perioperative mortality rate was 13 of 583 (2.2%). In this paper we summarise a number of studies that we have undertaken, comparing endovascular with alternative treatment methods and comparing various types of endovascular prostheses. In addition we report the long-term outcome of endovascular AAA repair as it relates to morphological changes in the proximal neck out to 9 years from operation. We conclude that despite the continuing small incidence of device failure, endovascular is the preferred method of AAA repair in the multifocal atherosclerotic patient. This view is based on the low perioperative mortality, superior survival compared with open repair and our experience of long-term stability in the proximal neck in the majority of patients.

Endoluminal repair of abdominal aortic aneurysms - state of the art.

This paper considers the historical aspects of endovascular aneursym repair; the major findings of our Departments experience over an 812-year period and reviews recent developments in endovascular prostheses. Analysis of 400 patients undergoing primary repair of abdominal aortic aneurysm between 1992 and 2000 revealed a perioperative mortality rate of 2.7% and primary conversion rate of 5%. With sequential studies it was shown that the outcome was better with bifurcated/aorto uni iliac grafts than tube grafts; better with second generation prostheses than first generation protheses and that survival in consecutive patients treated concurrently by open repair and endoluminal repair was superior in the endoluminal group. Endoluminal AAA repair is at a critical point of its development. It is unquestioned that it can dramatically reduce the need for intensive care and length of hospital stay and more recently it has been reported that survival is improved compared with open repair. The need for lifetime surveillance, the probability of graft failure and need for re-intervention, however, negate some of the advantages. The small incidence of unpredictable rupture following endoluminal AAA repair is a timely reminder of the need for continued careful follow-up.

Improved survival after endoluminal repair with second-generation prostheses compared with open repair in the treatment of abdominal aortic aneurysms: a 5-year concurrent comparison using life table method.

PURPOSE: The aim of this study was to compare the outcome of consecutive patients with abdominal aortic aneurysm (AAA) treated concurrently by means of open repair (OR) and endoluminal repair (ER) with second-generation prostheses by the same surgeons during a defined interval. METHODS: Between May 1995 and December 1998 second-generation (low profile, fully supported, modular) endoprostheses were implanted in 148 patients. These patients, together with 135 patients treated concurrently with OR during the same period, comprised the study group of 283 patients. Patient selection was based on aneurysm morphology. Those patients who were anatomically suitable for ER were treated with this method. The ER and OR groups were similar with regard to age, sex, and size of AAA. The ER group contained high-risk patients considered unfit for OR (n = 46), and the OR group contained high-risk patients who were anatomically unsuitable for ER (n = 19). Outcome criteria in both groups were survival and successful aneurysm repair. Success in the ER group was defined as exclusion of the aneurysm sac and stability or reduction in AAA maximum transverse diameter. Persistent endoleaks were classified as failures, regardless of whether they were subsequently corrected with secondary endovascular intervention. Data were analyzed with the life table method. The minimum period of follow-up for all patients was 18 months. RESULTS: The perioperative mortality rate was 5.9% in the OR group and 2.7% in the ER group (not significant). There was a statistically significant difference between the survival curves of the two groups in favor of the ER group when analyzed with the log-rank test (P =.004). The Kaplan-Meier curve for graft failure for the ER group revealed a 3-year graft success probability of 82%. Survival probability with successful repair in the OR group at 3 years was 85%. CONCLUSIONS: A concurrent comparison of ER with second-generation prostheses versus OR demonstrated a significant difference in survival in favor of the ER group. The probability of survival with successful repair at 3 years was similar in both groups.

Comparison of first- and second-generation prostheses for endoluminal repair of abdominal aortic aneurysms: a 6-year study with life table analysis.

PURPOSE: The outcome of endoluminal repair of abdominal aortic aneurysms with two generations of prostheses was analyzed and compared. METHODS: Between May 1992 and December 1998, 266 patients underwent elective endoluminal repair of an AAA. First-generation prostheses were used in 118 patients (group I), and second-generation prostheses were used in 148 patients (group II). The two groups were similar in age, sex, and size of AAA. The proportion of patients with comorbidities was higher in group I than in group II, but not significantly. First-generation devices were characterized by large (24F internal diameter) delivery systems, one-piece construction, and a lack of metallic support throughout their length. Second-generation devices had smaller (21F or smaller internal diameter) delivery systems, modular construction, and a metallic frame throughout the length of the prostheses. The major end-point criteria were survival and successful endoluminal repair. Success was defined as the exclusion of the aneurysm sac from the circulation, with stability or the reduction in AAA maximum transverse diameter. Persistent endoleaks were classified as failures, irrespective of whether they were subsequently corrected by means of secondary endovascular intervention. The minimum follow-up period was 5 months for each of the 266 patients. Analysis was performed by means of the life-table method. RESULTS: Perioperative mortality was not significantly different between group I (4.2%) and group II (2.7%). There was a statistically significant difference between the survival curves of the two generations, which favored group II (P =.012). There was a significant (P <.001) difference between the two generations of patients in their conditional probability of graft failure when the competing risk of all-cause mortality was considered. Second-generation patients were at a lower risk of graft failure than first-generation patients. The probability of failure, expressed as a proportion of grafts failing at 2 years, was 0.15 for patients with second-generation prostheses and 0.33 for patients with first-generation prostheses. CONCLUSION: Endoluminal AAA repair is a safe procedure, whether first- or second-generation prostheses are used. Survival and probability of graft success were significantly higher with second-generation prostheses than with first-generation prostheses. This improvement in outcome resulted from a combination of increasing clinical experience and advances in technology. A more accurate evaluation of the role of the endoluminal method in AAA repair would be achieved by studying patients in whom second-generation devices were used, rather than longer term studies in which first- and second-generation devices were used.

Life-table analysis of primary and assisted success following endoluminal repair of abdominal aortic aneurysms: the role of supplementary endovascular intervention in improving outcome.

AIM: the aim of this study was to analyse the effect of supplementary endovascular intervention on the outcome of primary endoluminal repair of abdominal aortic aneurysm (AAA). METHODS: between May 1992 and December 1998, 266 patients underwent endoluminal repair of AAA. Minimum period of follow-up was 6 months. Those patients in whom the endoprosthesis could not be deployed were converted to open repair at the primary operation. Patients developing an early endoleak, within 31 days, were treated by a period of observation and secondary endovascular intervention in persistent cases. Patients developing a late endoleak were treated similarly, without a period of observation. Outcome was analysed by the life-table method. Primary success was defined as exclusion of the aneurysm from the circulation resulting from the original operation. Assisted success occurred when aneurysms with endoleaks became excluded from the circulation as a result of supplementary endovascular intervention. RESULTS: endoluminal repair failed in 17 patients requiring conversion to open repair at the original operation. Supplementary endovascular intervention was undertaken in 26 patients, with early endoleaks (n=6) and late endoleaks (n=20). Interventions involved deployment of secondary endoluminal grafts within the primary grafts (n=22), and coil embolisation (n=4). Successful exclusion of the aneurysm sac was achieved in 22 of 26 (85%) patients undergoing supplementary endovascular procedures. Conditional cumulative incidence of primary graft failure and secondary graft failure in the presence of all-cause mortality at 6 years was 47% and 25% respectively. CONCLUSIONS: supplementary endovascular intervention is an important adjunct to endoluminal AAA repair with the potential to improve outcome and avoid conversion to open repair. Successful supplementary endovascular intervention was achieved in 85% of patients in whom it was attempted. Life-table analysis showed these supplementary procedures to be durable in the long term.

Rupture of abdominal aortic aneurysms: A concurrent comparison of outcome of those occurring after endoluminal repair versus those occurring de novo.

AIM: to compare the outcome of patients whose abdominal aortic aneurysm (AAA) ruptured following endoluminal repair with those whose AAA ruptured prior to treatment. PATIENTS: over a 4-year period 434 patients underwent treatment for AAA with conventional open (n=253) and endoluminal repair (n=181). Of those having open repair, 216 patients had elective operations while 41 had operations for ruptured AAA. Four patients with ruptured AAA had undergone endoluminal repair previously (Group I) while the remaining 37 patients ruptured de novo (Group II). The patients in both groups were similar in age and sex but differed clinically. All four patients in Group I had major medical co-morbidities versus 56% in Group II (p<0.05). All patients in group I had a known endoleak following endoluminal repair. All patients underwent open repair. RESULTS: the proportion of patients presenting with hypotension in Group I (1/4) was significantly less than in Group II (30/37). The difference in 30-day mortality for Group I (0%) compared with that for Group II (43%) was significant. The four patients in Group I remain alive and well at follow-up 22 months after operation. The outcome for Group I was better than Group II despite the higher incidence of medical co-morbidities. CONCLUSION: endoluminal AAA repair complicated by a persistent endoleak does not protect from rupture, which may not be accompanied by such major haemodynamic changes and high mortality as rupture de novo. Further long-term results in more patients are required to confirm this intermediate level of protection.

Early and late conversion from endoluminal to open repair.

Conversion from endoluminal to open repair of abdominal aortic aneurysms (AAA) may be primary, at the original operation or secondary, at a subsequent operation. The indications for primary conversion include aortic rupture and migration of an endograft resulting in obstructed blood flow and irreversible twisting of an endograft. The indications for secondary conversion include persistent endoleak, sealed endoleak with continued AAA expansion, apparently successful AAA repair, with continued expansion and the presence of an infected endograft. The technique of conversion varies from standard repair through modified standard repair to supraceliac control, depending on the cause of failure leading to conversion. All conversion procedures expose the patient to an increased risk and are best avoided by careful case selection, accurate sizing, and good procedural technique.