Morphometry and classification in abdominal aortic aneurysms: patient selection for endovascular and open surgery

Does the presence of an iliac aneurysm affect outcome of endoluminal AAA repair? An analysis of 336 cases

OBJECTIVE

To determine whether the presence of an iliac aneurysm compromises outcome of endovascular exclusion of AAA and to ascertain the fate of the iliac aneurysmal sac.

PATIENTS AND METHODS

Between April 1997 and March 2001, data on 336 consecutive patients undergoing endovascular repair for AAA were entered in a prospective database. Suitability for endovascular repair was assessed by preoperative contrast-enhanced computed tomography. A maximum common iliac artery (CIA) diameter > or = 20 mm was defined as iliac aneurysm. Patients with and without iliac aneurysms were compared to early (immediate conversion or perioperative death) and late failure (increase in aneurysm diameter or persisting graft-related endoleak, or late AAA rupture or conversion).

RESULTS

Fifty-nine patients (18%) had iliac aneurysms, 19 were bilateral, for a total of 78 aneurysmal iliac arteries (median diameter 23 mm; range 20-50 mm). A distal seal was achieved by landing in 33 external iliac arteries, in 20 ectatic CIAs, and in 25 normal CIAs. Operating time differed significantly between patients with and without CIA aneurysms (153 +/- 71 vs 123 +/- 55 min, p = 0.0001), whereas no statistically significant differences were found with respect to early and late failure (2% vs 3%, p = 0.5 and 14% vs 8%, p = 0.11, respectively). There were no cases of buttock or colon necrosis. At a median follow-up of 14 months (range 0-46; i.q.r. 7-27 months) common iliac diameter decreased > or = 2 mm in 49 cases, remained stable in 25, and increased > or = 2 mm in 3.

CONCLUSION

The presence of iliac aneurysm rendered endoluminal AAA repair more complex but did not affect feasibility and long-term outcome of the procedure. In our experience internal iliac exclusion was never associated with significant morbidity. These data may be useful when considering endovascular repair in high-risk patients with challenging anatomy.

Endovascular repair of abdominal aortic aneurysms: stent-graft fixation across the visceral arteries

PURPOSE

Recent studies have suggested that transrenal artery fixation of endovascular stent-grafts is safe and may be a desirable means of reducing the risk of type I endoleaks, particularly those with short infrarenal necks. The close proximity of the superior mesenteric and celiac arteries to the renal arteries may commonly result in the placement of the stent struts across all the vessels of the visceral segment of the aorta. The purpose of this study was to determine the incidence and impact of transvisceral artery fixation during aortic stent-graft deployment for the treatment of abdominal aortic aneurysms (AAAs).

METHODS

From January 1997 to June 1999, 192 patients (165 men, 27 women; mean age, 82 years) with AAAs were treated with an endovascular graft secured proximally to the aorta with a long (15 mm) uncovered stent segment (60 Parodi/Palmaz, 132 Talent-LPS). Preoperative and postoperative abdominal aortograms and intravenous contrast enhanced spiral computed tomography (CT) scans were performed. Follow-up CT scans were obtained at 3, 6, and 12 months and yearly thereafter as a means of determining stent position and visceral artery patency

RESULTS

In 95 patients (49%), the uncovered stent was at or above the level of the superior mesenteric artery. In 23 patients (12%), the stent extended to the level of the celiac axis. In a mean follow-up period of 25 months (range, 6-44 months), serum creatinine levels remained stable, no stenoses or occlusions occurred in the celiac, superior mesenteric, or renal arteries, and no evidence of renal, hepatic, splenic, or intestinal infarction was present on contrast enhanced spiral CT scans. There were no type I endoleaks.

CONCLUSION

Transvisceral fixation of the uncovered proximal aortic stent occurs frequently during deployment of devices designed for transrenal fixation and is associated with no early morbidity. Long-term follow-up is necessary to ensure that there are no late sequelae.

External iliac artery-to-internal iliac artery endograft: a novel approach to preserve pelvic inflow in aortoiliac stent grafting

PURPOSE

To describe four patients with abdominal aortic aneurysm and bilateral common iliac artery aneurysms repaired by coil embolization of the ipsilateral internal iliac artery, aortouniiliac endograft extended to the ipsilateral external iliac artery, femorofemoral bypass grafting, and a contralateral external iliac to internal iliac stent graft to preserve pelvic perfusion.

METHODS

Four patients with multiple risk factors, abdominal aortic aneurysm (mean diameter, 6.6 cm), and bilateral common iliac artery aneurysms were evaluated with contrast-enhanced computed tomography scanning, arteriography, and intravascular ultrasonography. Aortobiiliac endovascular abdominal aortic aneurysm repair was not feasible because of extension of the common iliac artery aneurysms to the iliac bifurcation bilaterally.

RESULTS

The abdominal aortic aneurysms were repaired with an aortouniiliac endograft. The ipsilateral common iliac artery aneurysms were treated by coil embolization of the internal iliac artery and extension of the endograft to the external iliac artery. The contralateral common iliac artery aneurysms were excluded by a custom-made stent graft (n = 2) or a commercial stent graft (n = 2) from the external iliac artery to the internal iliac artery, which preserved pelvic inflow via retrograde perfusion from the femorofemoral bypass. Mean length of stay was 3.5 days. One patient had hip claudication. Follow-up (mean 10 months, range 6 to 17) demonstrated exclusion of the abdominal aortic aneurysm and common iliac artery aneurysms with no endoleak and patent external iliac artery-to-internal iliac artery endografts in all patients.

CONCLUSION

Patients with bilateral common iliac artery aneurysms that extend to the iliac bifurcation may be excluded from endovascular abdominal aortic aneurysm repair because of concerns regarding pelvic ischemia after occlusion of both internal iliac arteries. External iliac artery-to-internal iliac artery endografting is a feasible alternative to maintain pelvic perfusion and still allow endograft repair of the abdominal aortic aneurysm in these patients.

Impact of exclusion criteria on patient selection for endovascular abdominal aortic aneurysm repair

PURPOSE

Wide-ranging predictions have been made about the usefulness of endovascular repair for patients with abdominal aortic aneurysms (AAAs). The availability of US Food and Drug Administration-approved devices has removed the restrictions on patient selection, which had been controlled by device trials. This study examined the applicability of endovascular AAA repair and identified the anatomic barriers to successful endovascular AAA repair that should guide future device development.

METHODS

All patients who came to our institution for infrarenal AAA repair between April 1998 and June 2000 were offered evaluation for endovascular repair. Thin-cut spiral computed tomography scans and arteriograms were obtained on all patients, and their anatomic characteristics were prospectively entered into a database. A wide selection of available devices allowed the treatment of diverse AAA anatomic features.

RESULTS

A total of 307 patients were examined (264 men, 43 women). Of these, 204 patients (66%; 185 men, 19 women) underwent endovascular repair, and 103 patients (34%, 79 men, 24 women) were rejected. Reasons for exclusion included short aneurysm neck (56, 54%), inadequate access because of small iliac arteries (48, 47%), wide aneurysm neck (41, 40%), presence of bilateral common iliac aneurysms extending to the hypogastric artery (22, 21%), excessive neck angulation (14, 14%), extensive mural thrombus in the aneurysm neck (10, 10%), extreme tortuosity of the iliac arteries (10, 10%), accessory renal arteries originating from the AAA (6, 6%), malignancy discovered during the examination (5, 5%), and death during the examination interval (2, 2%). Rejected patients had an average of 1.9 exclusion criteria (range, 1 to 4). A disproportionate number of women were excluded because of anatomic findings (P = .0009). Although 80% of patients who were at low risk for surgery qualified for endovascular repair, only 49% of our patients who were at high risk for surgery were acceptable candidates (P < .001). Of the 103 patients who were excluded, 34 (33%) underwent open surgical repair, and the remaining 69 (67%) were deemed to be unfit for open surgery. Three patients (1.4%) failed endograft placement because of inadequate vascular access.

CONCLUSION

Most infrarenal AAAs (66%) can be treated with endovascular devices currently available commercially or through US Food and Drug Administration-approved clinical trials. However, patients who are at high risk for surgery and might benefit most from endovascular repair are less likely to qualify for the procedure (49%). Men (70%) are more likely than women (40%) to meet the anatomic criteria for endografting. Difficulties with vascular access and attachment site geometry predominate as reasons for exclusion. Our findings suggest that smaller profile devices, which can negotiate small and tortuous iliac arteries, are needed. Proximal and distal attachment site problems require devices that can accommodate wide and angulated attachment necks and achieve short seal zones.

EVT endovascular graft for abdominal aortic aneurysm

BACKGROUND

A variety of prostheses are now available for the endovascular treatment of abdominal aortic aneurysm (AAA). Significant advantages of the EVT device are its unibody design, secure hook attachment system and graft fabric approximating that used in conventional surgery.

METHODS

Implantation of the EVT device was attempted in 60 patients who were studied prospectively with an analysis of subsequent problems encountered.

RESULTS

Conversion to open repair was required in four cases (6.7%). There were nine tube grafts inserted, 13 aorto-unilateral iliac with crossover grafts and 34 aorto-bi-iliac grafts. There was one death (mortality 1.7%). Endoleaks were identified in eight patients (14%), none of which were proximal; three sealed spontaneously, two were treated with coil embolization, two are being observed and one patient had an iliac attachment converted to an open anastomosis. Access vessel problems were seen in 21 patients (35%); two-thirds were corrected at the time of initial surgery. Seven patients (12%) had primary graft limb problems identified and treated before leaving the operating room. Nine patients (16%) developed secondary graft limb problems, which were diagnosed and treated after the initial surgery. Endovascular treatment was used in eight and was successful in six with surgical revision required in two. On review of these cases to assess if the problem could have been predicted at the time of initial surgery, it was felt that more aggressive treatment of intraoperatively diagnosed graft limb stenoses, even though considered mild, may have prevented 50% of subsequent secondary graft limb occlusions.

CONCLUSION

Although the EVT device has significant advantages in the endovascular management of aortic aneurysm, potential graft limb problems need to be actively identified with the majority able to be successfully managed by supplementary endovascular techniques.

Hypogastric artery embolization in endovascular abdominal aortic aneurysm repair

PURPOSE

Iliac artery anatomy is a central factor in endoluminal abdominal aortic aneurysm therapy. It serves as the conduit for graft deployment and as the region of distal graft seal. Thirty-eight percent of iliac vessels in our patients require special treatment because of aneurysms, tortuosity, or small size. Bilateral hypogastric artery exclusion has been avoided because of concerns of colorectal ischemia, hip/buttock claudication, and impotence. We suggest that elective, staged, bilateral hypogastric embolization can be performed safely with reasonably low morbidity and can expand the anatomic boundaries for stent-graft abdominal aortic aneurysm repair.

METHODS

This study was performed as a retrospective chart review of patients requiring hypogastric artery embolization for endovascular repair of abdominal aortic aneurysms between June 1998 and June 2000. Patients with otherwise appropriate anatomy and common iliac artery aneurysms were informed of the option for stent-graft repair with internal iliac artery embolization with its risks of impotence, hip/buttock claudication, and bowel ischemia. Patients underwent unilateral or staged bilateral coil embolizations of their proximal hypogastric arteries with an approximate 1-week interval between procedures. Hospital and office records were reviewed; phone interviews were performed. Follow-up ranged from 1 to 12 months.

RESULTS

During a 24-month period, 65 patients underwent endovascular abdominal aortic aneurysm repair; 18 patients (28%) required hypogastric artery embolization. Seven (39%) of these patients underwent bilateral embolization. There were no episodes of clinically evident bowel ischemia. Lactate levels were normal in all measured patients. Postoperative fevers (> 101.0 degrees F) were documented in 10 (56%) of 18 patients. The average white blood cell count was 12.8 x 10(9)/L (range, 8.5-22.9). There were no positive blood culture results. The return to the full preoperative diet occurred in 1 to 3 days. Hip/buttock claudication occurred in approximately 50% of patients with persistent but improved symptoms at 6 months. Eighty-seven percent of patients had preoperative erectile dysfunction. Only two patients noted worsening of erectile function postoperatively.

CONCLUSIONS

Preliminary results indicate that bilateral hypogastric artery embolization can be performed, when necessary, with reasonable morbidity in patients undergoing stent-graft abdominal aortic aneurysm repair.

Advances in interventional radiology. The search for less invasive management sparks new approaches

Many new, minimally invasive interventional radiology procedures are now viable alternatives to traditional invasive therapy. The radiology procedures can often be performed in the outpatient setting, and although expensive technology may be required, the overall cost to the patient may be lower in the long run. Endovascular repair of abdominal aortic aneurysms with stent grafts and radiofrequency tumor ablation are examples of rapidly expanding technologies in interventional radiology. Patient enthusiasm and interest are the primary forces driving these advances in management. Familiarity with these procedures is vital as medicine moves into the new millennium.

Carbon dioxide angiography for endovascular grafting in high-risk patients with infrarenal abdominal aortic aneurysms

Allergic reactions to contrast media, preexisting renal dysfunction, and hyperthyroidism are relative contraindications for angiography with conventional contrast medium. Carbon dioxide (CO(2)) angiography is an alternative method in high-risk patients because CO(2) is nontoxic, without allergic potential, and not iodic. CO(2)-related complications are extremely rare. Because renal insufficiency often occurs in vascular patients, this method will become increasingly important for endovascular surgery. We report on three consecutive patients with asymptomatic infrarenal aortic aneurysm and concomitant renal dysfunction or allergic reactions to standard contrast media. Aortic stent grafts were deployed under CO(2) angiographic control without complications or worsening of renal function.

Suitability for endovascular aneurysm repair in an unselected population

BACKGROUND

Tertiary referral centres report that up to 60 per cent of patients may be suitable for endovascular repair of abdominal aortic aneurysm (EVAR). The aim of this study was to determine the percentage of abdominal aortic aneurysms (AAAs) presenting to a county-wide vascular service that were suitable for EVAR, and to examine the outcome of subsequent AAA repair in relation to aneurysm morphology.

PATIENTS AND METHODS

All patients being assessed for AAA repair between January 1998 and December 1999 underwent spiral computed tomography angiography to determine aneurysm morphology and suitability for EVAR. Subsequent outcome for all patients in the study was recorded in a prospective vascular database.

RESULTS

A total of 115 patients was assessed. Sixty-three aneurysms (55 per cent) had one or more absolute contraindications to EVAR, a further 13 (11 per cent) had at least one relative contraindication, and 39 (34 per cent) had no contraindication. Of patients with no absolute contraindication to EVAR, ten underwent successful EVAR, five did not meet recognized criteria for surgery, one awaits EVAR, four remain under observation, one awaits open repair, and 31 underwent open repair without death.

CONCLUSION

Only 30 per cent of unselected AAAs presenting to a vascular service are entirely suitable for EVAR; most of these patients can safely undergo open AAA repair. These data suggest that increased use of EVAR is only possible by deploying devices in suboptimal morphology, and in treating patients who would not normally be considered for open AAA repair.

Endovascular repair of abdominal aortic aneurysms: eligibility rate and impact on the rate of open repair

OBJECTIVE

The purpose of this study was to determine the rate of eligibility among patients with abdominal aortic aneurysms (AAAs) considered for endovascular repair and to examine the effect of an endovascular program on the institutional pattern of AAA repair.

METHODS

All patients evaluated for endovascular AAA repair since the inception of an endovascular program were reviewed for determination of eligibility rates and eventual treatment. Open AAA repairs were categorized as simple (uncomplicated infrarenal), complex (juxtarenal, suprarenal, thoracoabdominal, infected), or ruptured, and their rates before and after initiation of an endovascular program were compared.

RESULTS

Over 3 years, 324 patients were considered for endovascular AAA repair; 176 (54%) were candidates, 138 (43%) were not candidates, and 10 (3%) did not complete the evaluation. The rate of eligibility increased significantly from 45% (66/148 patients) during the first half of this period to 63% (110/176 patients) during the second half (P <. 001). Candidates were significantly younger (74.4 +/- 7.6 years) than noncandidates (78.3 +/- 6.7 years) (P <.01), and their aneurysm diameter tended to be smaller (57.6 +/- 9.2 mm compared with 60.8 +/- 12.3 mm; P =.06). The most common reason for ineligibility was an inadequate proximal aortic neck. Of 176 candidates, 78% underwent endovascular repair, and 6% underwent open repair. Of 138 noncandidates, 56% underwent surgical repair. Over a period of 6 years, 542 patients with AAAs (429 simple, 86 complex, 27 ruptured) underwent open repair. The total number and ratio of simple to complex open repairs for nonruptured aneurysms during the 3 years before the initiation of the endovascular program (213 simple, 44 complex) were not significantly different from the repairs over the subsequent 3-year period (216 simple, 42 complex). Similarly, no difference in the total number and the ratio of simple to complex open repairs was found between the first and the second 18-month periods since the initiation of the endovascular program.

CONCLUSIONS

The rate of eligibility of patients with AAA for endovascular repair appears to be higher than previously reported. The presence of an active endovascular program has not decreased the number or shifted the distribution of open AAA repair.

Relocation of the iliac artery bifurcation to facilitate endoluminal treatment of abdominal aortic aneurysms

PURPOSE

To report a surgical technique to preserve the internal iliac arteries (IIAs) and facilitate endovascular repair of abdominal aortic aneurysms (AAAs) with extensive iliac artery involvement.

TECHNIQUE

A new iliac artery bifurcation is created surgically through an 8-cm lower left abdominal incision by implanting the IIA onto the distal external iliac artery either directly or by using a tube graft interposition. Careful technique is required to avoid embolic complications, but after relocating the bifurcation, aortic endografting can be performed, either simultaneously or staged, depending upon patient characteristics.

CONCLUSIONS

Relocation of the iliac artery bifurcation appears to be a good alternative to preserve pelvic arterial flow in selected candidates for endoluminal AAA repair.

Endovascular repair of abdominal aortic aneurysms: where do we stand?

Endovascular repair of abdominal aortic aneurysms has evolved dramatically within the past few years. In light of the potential to reduce morbidity and mortality associated with open surgical repair, endoluminal grafting offers therapeutic options to patients who are not surgical candidates because of comorbidities. With the development of bifurcated devices, more complex aneurysms may be treated by endovascular grafting. Although successful placement of endovascular grafts requires a pronounced learning curve, including appropriate patient selection, midterm results seem consistent with those of traditional open repair of aneurysms. This review describes the current indications, minimal requirements, different devices and associated techniques, and potential complications of endoluminal repair of abdominal aortic aneurysms. Future aspects of endoluminal grafting are also discussed.

Abdominal aortic aneurysm morphology in candidates for endovascular repair evaluated with spiral computed tomography and digital subtraction angiography

PURPOSE

To analyze the morphology of abdominal aortic aneurysms (AAAs) and to study the usefulness of spiral computed tomography (CT) versus digital subtraction angiography (DSA) in the evaluation of patients for endovascular repair.

METHODS

Of 133 AAA patients (120 men, mean age 67 years, range 52 to 84) evaluated preoperatively with CT imaging, 77 endograft candidates (68 men) were also assessed with intra-arterial DSA. Arterial parameters were measured on axial CT scans and angiographic films for comparison.

RESULTS

Mean maximum AAA diameter was 58 +/- 11 mm (range 39 to 95). Aneurysmal neck diameter was consistently smaller on DSA than on CT (20.7 +/- 3.6 mm versus 23.0 +/ 3.5 mm, p < 0.0001). The distance from the most distal renal artery to the aortic bifurcation was longer on angiography than on CT (mean difference 10.0 mm, p < 0.0001). There was a positive correlation between the maximum AAA diameter and the AAA length (r = 0.49, p < 0.0001) and an inverse relationship between the neck length and the neck diameter (r = -0.36, p < 0.0001). No correlation was found between the maximum AAA diameter and maximum iliac diameter, angulation, or length.

CONCLUSIONS

AAA anatomy varies widely and independently of the aneurysm size. Therefore, the maximum size of the aneurysm is a poor predictor of whether or not an aneurysm is suitable for endovascular repair. The discrepancy between angiographic and axial CT measurements suggests that neither alone is sufficient as a preoperative imaging technique when evaluating a patient for an endovascular graft procedure.

Endovascular treatment of aortoiliac aneurysms: made-to-measure stent-grafts increase feasibility

We describe here our preliminary experience with use of a range of made-to-measure stent-grafts made from commercially available components. From January 1996 to June 1998, 94 aortoiliac aneurysms (AIA) were treated with stent-grafts that were made to measure using Z autoexpandable stainless steel stents connected with polyester sutures and covered with commercially available polyester vascular prostheses. These stent-grafts were implanted through 18 to 24 (typically 20) Fr commercially available introducers via a surgical remote access. Made-to-measure tubular, bifurcated, tapered, and/or blind stents combined with extraanatomic bypass designs increased the rate of endovascular treatment (ET) of AIA in this series. This rate was further increased through the use of uncovered proximal or distal stents when dealing with short or tortuous necks near major collaterals and through use of hybrid, partly surgical designs, one with stented and the other with stentless ends, the latter allowing for a surgically made anastomosis. The results of our experience with these techniques show that use of made to-measure stent-grafts greatly increases the feasibility of the ET of AIA among unselected patients while offering enough efficiency and safety to deserve further investigation.

Endovascular repair of abdominal aortic aneurysm using the EVT device: limited increased utilization with availability of a bifurcated graft

PURPOSE

To determine if the availability of a bifurcated graft would increase the percentage of patients eligible for endovascular repair of abdominal aortic aneurysms (AAAs).

METHODS

One hundred eighty-five consecutive patients were evaluated prospectively for endovascular AAA repair at a university referral center. Data were collected on eligibility for tube or bifurcated endovascular grafts, reasons for exclusion, aneurysm morphology, and the interventions performed.

RESULTS

Forty-six (25%) patients were eligible for endovascular treatment using the first-generation Endovascular Technologies (EVT) system: 19 (10%) for a tube graft and 27 (15%) for a bifurcated device. An unsuitable proximal neck was the reason for exclusion in 48% of patients (excess diameter in 27%, inadequate length in 21%). Unsuitable iliac configuration was present in 41% of those excluded; 29% of the common iliac arteries were enlarged or aneurysmal, while 12% were small or tortuous.

CONCLUSIONS

Although a bifurcated graft more than doubles the eligibility of AAA patients for endovascular repair, the configuration of the proximal neck and iliac disease excluded the majority of AAA patients from endovascular therapy using the first generation EVT device.

Impact of transrenal aortic endograft placement on endovascular graft repair of abdominal aortic aneurysms

PURPOSE

Successful endovascular repair of an abdominal aortic aneurysm (AAA) requires the creation of a hemostatic seal between the endograft and the underlying aortic wall. A short infrarenal aortic neck may be responsible for incomplete aneurysm exclusion and procedural failure. Sixteen patients who had an endograft positioned completely below the lowest renal artery and 37 patients in whom a porous portion of an endograft attachment system was deliberately placed across the renal arteries were studied to identify if endograft positioning could impact on the occurrence of incomplete aneurysm exclusion.

METHODS

Fifty-three patients underwent aortic grafting constructed from a Palmaz balloon expandable stent and an expandable polytetrafluoroethylene (ePTFE) graft implanted in an aorto-ilio-femoral, femoral-femoral configuration. Arteriography, duplex ultrasonography and spiral CT scans were performed in each patient before and after endografting to evaluate for technical success, the presence of endoleaks, and renal artery perfusion.

RESULTS

There was no statistically significant difference in patient demography, AAA size, or aortic neck length or diameter between patients who had their endografts placed below or across the renal arteries. However, significantly more proximal aortic endoleaks occurred in those patients with infrarenal endografts (P < or = .05). Median serum creatinine level before and after endografting was not significantly different between the 2 patient subgroups, with the exception of 2 patients who had inadvertent coverage of a single renal orifice by the endograft. Median blood pressure and the requirement for antihypertensive therapy remained the same after transrenal aortic stent grafting. Significant renal artery compromise did not occur after appropriately positioned transrenal stents as shown by means of angiography, CT scanning, and duplex ultrasound scan. Mean follow-up time was 10.3 months (range, 3 to 18 months). Patients who had significant renal artery stenosis (> or =50%) before aortic endografting did not show progression of renal artery stenosis after trans-renal endografting. Two patients with transrenal aortic stent grafts had inadvertent coverage of 1 renal artery by the endograft because of device malpositioning, which resulted in nondialysis dependent renal insufficiency. In addition, evidence of segmental renal artery infarction (<20% of the kidney), which did not result in an apparent change in renal function, was shown by means of follow-up CT scans in 2 patients with transrenal endografts.

CONCLUSION

Transrenal aortic endograft fixation using a balloon expandable device in patients with AAAs can result in a significant reduction in the risk of proximal endoleaks. Absolute attention to precise device positioning, coupled with the use of detailed imaging techniques, should reduce the risk of inadvertent renal artery occlusion from malpositioning. Long-term follow-up is essential to determine if there will be late sequelae of transrenal fixation of endografts, which could adversely effect renal perfusion.

Endoluminal abdominal aortic aneurysm surgery

BACKGROUND

The development of devices designed for the endoluminal repair of abdominal aortic aneurysm has led to the emergence of new endovascular techniques.

METHODS

Articles and case reports obtained from a Medline search of the English language literature from 1989 to 1997 are reviewed. This search was carried out using the MeSH heading 'aortic aneurysm, abdominal' and the keywords 'endovascular' and 'endoluminal'.

RESULTS

Reported mortality and complication rates for endoluminal aneurysm repair are similar to those following conventional repair, with the exception of continued perfusion of the aneurysm sac which remains a major problem following endoluminal repair.

CONCLUSION

Successful endoluminal aneurysm exclusion is associated with reduced aneurysm diameter. However, longer term results of endoluminal repair, in particular of sealed endoleaks, are required before randomized controlled trials of endoluminal versus conventional repair can be undertaken.

Three-year experience with modular stent-graft devices for endovascular AAA treatment

PURPOSE

To evaluate feasibility and present early results of endovascular abdominal aortic aneurysm (AAA) exclusion using modular stent-grafts.

METHODS

In a 3-year period ending July 1997, 201 patients were treated with self-expanding stent-grafts for AAAs with infrarenal necks > or = 10 to 15 mm long and < or = 32 mm wide; subtotal mural thrombus, calcification, and even angulation to some extent were acceptable, as were iliac arteries up to 18 mm wide. The patients were treated with either the Stentor/Vanguard device (178 cases) or the Talent endograft (23 cases). Follow-up on all patients was conducted at 3, 6, 12, 18, and 24 months.

RESULTS

The technical aneurysm exclusion rate was 89% (178/201). There were 18 primary endoleaks (9.0%; 2 proximal, 16 distal), 4 (2.0%) conversions to open surgery, and 1 (0.5%) failure to deploy the graft. Seven (3.5%) patients died in the perioperative period, 5 due to multiorgan failure early in the series and two of hemorrhagic complications. Five (2.5%) renal artery occlusions were encountered; in one case, the graft was removed after 3 weeks. Nineteen late endoleaks were found in follow-up, related primarily to the iliac limb graft extensions of the Stentor device, graft material problems, or unknown causes. To date, 10 primary and 13 secondary endoleaks have been treated endovascularly. Twenty (10.0%) graft-limb thromboses were treated either by thrombolysis, thrombectomy, or a femorofemoral bypass.

CONCLUSIONS

Endovascular grafting is technically feasible and becomes easier with improvements of the introducer systems and the grafts. The seemingly high complication rate in this series is due to the liberal patient selection criteria.