Surgical management of abdominal aortic aneurysm in the high-risk patient

Endovascular Treatment of Abdominal Aortic Aneurysms: Lessons Learned

The authors offer an overview of their 20-year involvement in the development of an endovascular graft for abdominal aortic aneurysm exclusion. Clinical experience gained throughout 6 years of clinical evaluation are reviewed, along with observations and insights on preoperative assessment, implantation techniques, and complications.

Abdominal Aortic Aneurysm Repair in Octogenarians versus Younger Patients in a Tertiary Referral Center

Operative survival is as high as 96% for elective abdominal aortic aneursym (AAA) repair but as low as 10% for emergency repair. Our primary aim was to compare elective AAA repair in octogenarians with nonoperative management. Our secondary aim was to compare octogenarians with their younger counterparts.

From 1998 to 2003, 180 patients with AAA were treated operatively or nonoperatively. Factors determining treatment included American Society of Anesthesiologists grade ≥ 4, inoperable malignancy, New York Heart Association class III, forced expiratory volume in 1 second < 35%, creatinine > 6.0 mg/dL, and patient and family choice. A parallel-group observational study was performed to assess age and treatment effects on outcome.

Seventy (39%) patients were repaired electively, 68 (38%) were managed nonoperatively, and 42 (23%) underwent emergency repair. Fifty-nine (33%) were octogenarians.

The octogenarian 5-year survival rate was 20% following emergency repair, 42% if treated nonoperatively, and 83% following elective repair. Younger cohort rates were 55% (emergency), 44% (nonoperative), and 76% (elective).

The octogenarian mean expansion rate was 0.26 cm/yr in those treated nonoperatively and 1.04 cm/yr in confirmed rupture. Rupture rate was related to expansion rate (95% confidence interval [CI] 0.06–0.59, r = .35, p = .01). The rates in the younger subgroup were 0.32 cm/yr and 1.14 cm/yr (95% CI −0.021–0.672}, r = .37, p = .03).

The octogenarian survival rate was highest following elective repair. Rupture was closely correlated with aneurysm expansion. Screening should reduce the incidence of octogenarian rupture of AAA and identify those patients most suitable for nonoperative management.

Comparação entre os tratamentos aberto e endovascular dos aneurismas da aorta abdominal em pacientes de alto risco cirúrgico

OBJETIVO: Comparar os resultados dos tratamentos aberto e endovascular de aneurismas da aorta abdominal em pacientes de alto risco cirúrgico. MÉTODOS: O tratamento aberto foi realizado em 31 pacientes, e o endovascular, em 18. Sucesso no tratamento endovascular foi definido como perviedade da endoprótese sem endoleaks ou conversão para tratamento aberto. RESULTADOS: Não houve diferença na mortalidade perioperatória entre o tratamento aberto (dois óbitos [6,45%] em 31) e o endovascular (um óbito [5,55%] em 18) (P = 0,899); também não houve diferença entre a mortalidade tardia no tratamento aberto (dois óbitos [6,9%] em 29) e no endovascular (dois óbitos [11,7%] em 17) (P = 0,572). A taxa de sucesso imediato foi de 100% (31/31) no tratamento aberto e de 66,7% (12/18) no endovascular (P = 0,0006); a taxa de sucesso tardio foi de 100% (27/27) no tratamento aberto e de 73,3% (11/15) no endovascular (P = 0,0047). Os valores médios do tempo de internação na UTI, tempo de internação hospitalar e da perda de sangue para os grupos dos tratamentos aberto e endovascular foram: 65,6 versus 34,1 horas*, 9 versus 5,6 dias* e 932 versus 225 ml*, respectivamente (*P < 0,05). O tratamento endovascular foi 436% mais caro que o tratamento aberto. CONCLUSÕES: Na presente série, o tratamento aberto foi o método mais confiável para o reparo dos aneurismas da aorta abdominal, apresentando a mesma mortalidade perioperatória e tardia que o endovascular.

Endovascular treatment of abdominal aortic aneurysms: lessons learned

The authors offer an overview of their 20-year involvement in the development of an endovascular graft for abdominal aortic aneurysm exclusion. Clinical experience gained throughout 6 years of clinical evaluation are reviewed, along with observations and insights on preoperative assessment, implantation techniques, and complications.

Results of endoluminal grafting in an experimental aortic aneurysm model

We studied the impact of an endoluminally placed stented aortic graft on the geometry of a surgically created abdominal aortic dilation (AAD) in nonatherosclerotic mongrel dogs. Patulous iliac vein patch infrarenal aortoplasty produced a fusiform AAD, doubling the aorta diameter. Lumbar and mesenteric aortic tributaries were preserved and no mural thrombus formed. AADs created in 23 dogs were endoluminally excluded through transfemoral placement of a thin-wall Dacron graft 4 +/- 2 months later. Balloon-expandable stents were used to anchor each end of the graft to the aorta. The graft was crimped radially in its body and longitudinally at its ends to provide longitudinal and radial expandability in these respective zones. Serial color duplex, angiography, and direct caliper measurements were made. Before graft placement, a 19% +/- 11% diameter growth was observed. At graft placement, flow arrest immediately occurred in the space between the graft and the AAD intima in all cases. Although microscopic recanalization of the thrombus in this space was seen at sacrifice 6 and 12 months later, no macroscopic duplex flow was imaged. A 10% +/- 11% reduction in AAD diameter was measured at 6 months (p < 0.001), with no further reduction at 12 months. Graft dimensions remained stable. No anastomotic leaks developed. AAD growth stopped during the first year after effective endoluminal exclusion in normotensive dogs despite patent side branches (< 1.5 mm internal diameter) and no mural thrombus at the time of graft placement. Whether microscopic recanalization of the thrombus that forms outside the graft has an impact after 1 year remains to be seen.

A review of 103 cases with elective repair for abdominal aortic aneurysm: an analysis of the risk factors based on postoperative complications and long-term follow-up

From 1982 through 1992, 103 patients (mean age: 69 years) underwent an elective repair of an abdominal aortic aneurysm (AAA) at our institution. One or more postoperative complications occurred in 30 patients (29%), with a mortality rate of 1.9%. Factors which were found to be significantly associated with postoperative complications based on an univariate analysis included male sex (P = 0.0082), operation time (P = 0.0006), the size of the aneurysm (P = 0.0045), the amount of blood loss during operation (P = 0.0037), poor lung function (P = 0.0155), and the platelet count (P = 0.0468). A simple linear regression analysis showed that there were significant correlations among the AAA size, the duration of operation and the amount of blood loss. The age at operation, however, did not influence morbidity or mortality. Complete survival information was obtained in 96 (95%) patients, while the influence of preoperative risk factors on late survival was also examined by the Kaplan-Meier method. The factors influencing long-term survival were determined to be renal dysfunction and age at the time of operation.

Vascular disease in the elderly patient

At a time of potentially dramatic changes in health care policy in this country, and in view of the necessity for health care cost containment, physicians are expected to exercise serious introspection in the selection of treatment for the elderly patient with peripheral arterial disease. These decisions should be made while acknowledging that it is the goal of the health-care provider "to postpone chronic illness, to maintain vigor, and to slow social and psychological involution." For the elderly patient with an abdominal aortic aneurysm, with significant carotid disease, or with limb-threatening peripheral ischemia, the evidence is compelling that timely surgical intervention in properly selected patients is well tolerated and will satisfy this goal.

Transfemoral intraluminal graft implantation for abdominal aortic aneurysms

This study reports on animal experimentation and initial clinical trials exploring the feasibility of exclusion of an abdominal aortic aneurysm by placement of an intraluminal, stent-anchored, Dacron prosthetic graft using retrograde cannulation of the common femoral artery under local or regional anesthesia. Experiments showed that when a balloon-expandable stent was sutured to the partially overlapping ends of a tubular, knitted Dacron graft, friction seals were created which fixed the ends of the graft to the vessel wall. This excludes the aneurysm from circulation and allows normal flow through the graft lumen. Initial treatment in five patients with serious co-morbidities is described. Each patient had an individually tailored balloon diameter and diameter and length of their Dacron graft. Standard stents were used and the diameter of the stent-graft was determined by sonography, computed tomography, and arteriography. In three of them a cephalic stent was used without a distal stent. In two other patients both ends of the Dacron tubular stent were attached to stents using a one-third stent overlap. In these latter two, once the proximal neck of the aneurysm was reached, the sheath was withdrawn and the cephalic balloon inflated with a saline/contrast solution. The catheter was gently removed caudally towards the arterial entry site in the groin to keep tension on the graft, and the second balloon inflated so as to deploy the second stent. Four of the five patients had heparin reversal at the end of the procedure. We are encouraged by this early experience, but believe that further developments and more clinical trials are needed before this technique becomes widely used.

A case of metachronous aneurysm of the infrarenal abdominal aorta

The case history of an 84 year old woman presenting with a metachronous aneurysm of the infrarenal abdominal aorta is presented. At operation this second aneurysm was replaced by a further straight tube Dacron inlay graft. This report raises the important question as to whether the whole of the infrarenal aorta should be replaced when resecting an infrarenal abdominal aortic aneurysm, rather than the more conventional approach of suturing the graft to the neck of the aneurysm above and the aortic bifurcation below.