Suitability for endovascular aneurysm repair in an unselected population

Excluder Stent Graft-Related Outcomes in Patients with Aortic Neck Anatomy Outside of Instructions For Use (IFU) within the Global Registry for Endovascular Aortic Treatment (GREAT): Mid-term Follow-Up Results

BACKGROUND

The utilisation rate of endovascular aortic aneurysm repair has increased continuously over the past 2 decades. Endovascular aortic aneurysm repair is still performed frequently in patients with an unfavourable proximal seal zone, despite the associated late complications.

PURPOSE

We aimed to evaluate the mid-term durability of the GORE® EXCLUDER® AAA Endoprosthesis, featuring the C3 delivery system, in patients with a proximal neck anatomy outside the instructions for use (IFU).

METHODS

A retrospective sub-analysis of the Global Registry for Endovascular Aortic Treatment including patients treated for abdominal aortic aneurysms with the GORE EXCLUDER AAA Endoprosthesis (W.L. Gore & Associates, Inc, Flagstaff, Arizona) was performed. A "challenging neck" was defined as those treated outside the IFU with an aortic neck length <15 mm and/or aortic neck angle >60°. Cox proportional analyses were used to test for time-to-event differences between those treated within and outside the IFU while accounting for covariates, specifically proximal neck length and neck angle. The main outcomes assessed were 5-year all-cause mortality, 5-year endoleak development (type I or III), and 5-year device-related reinterventions.

FINDINGS

Of the 3,324 patients included in the analysis, 411 (12.4%) had a challenging neck and 2,913 (87.6%) did not. The patients in the challenging neck group were significantly older (74.9 years vs. 73.2 years, p≤0.0001) and had a significantly larger aortic aneurysm diameter at the time of the intervention than those treated within the IFU (61.2 mm vs. 56.4 mm, P< 0.0001), shorter proximal neck length (18 mm vs. 30 mm, P< 0.0001) and larger infrarenal neck angle (60.8° vs. 25.8°, P< 0.0001). In the multivariate analysis, brachial access site and challenging neck were not independent risk factors; increased age was associated with a shorter time to mortality (hazard ratio 1.051, 95% confidence interval 1.039-1.062, P< 0.0001), as was the use of tobacco (hazard ratio 1.329, 95% confidence interval 1.124-1.571, P= 0.0009). The 5-year all-cause mortality (36.2% vs. 27.5%, P= 0.002) and aorta-related mortality (3.8% vs. 1.1%, P= 0.002) were significantly higher in the challenging neck group. The risk of death within 5 years also increased significantly at 1.1% per millimetre increase in the abdominal aortic aneurysm diameter (P= 0.0005). Furthermore, the rates of type Ia endoleak development (7% vs. 1.2%, P< 0.001) and requirement for reintervention (13.3% vs. 9.7%, P< 0.001) were higher in those treated outside the IFU (challenging neck group).

CONCLUSIONS

Treatment with the Excluder AAA Endograft outside the IFU was associated with higher 5-year mortality values, increased type Ia endoleak development rates, and a greater need for reintervention compared with treatment within the IFU. This reiterates that fenestrated and open treatments should be strongly considered in cases with aortic neck anatomies outside the IFU. Infrarenal endovascular intervention outside the IFU should only be used when there is no alternative, with meticulous procedural planning and intervention to promote satisfactory outcomes.

Preliminary Clinical and Radiologic Outcome of Matched Patients with Thoracoabdominal Aortic Aneurysms Treated by Low-Profile vs Standard Profile Branched Aortic Endografts

BACKGROUND

Durability of low-profile branched aortic stent-grafts (LPSG) in the treatment of patients with thoracoabdominal aortic aneurysms (TAAA) remains unclear. Objective of this study is to compare the outcomes of LPSG with standard profile branched aortic stent-grafts (SPSG).

METHODS

Between January 2016 and January 2020, 225 consecutive patients with TAAA were treated by branched endovascular aortic repair (BEVAR). Twenty-four patients who were treated with a LPSG were compared to 24 patients who received SPSG as a control group. Control patients were selected according to aneurysm size (maximum aneurysm diameter) and extension (Crawford classification) as well as availability of adequate preoperative and postoperative CT-angiograms at 24 months. The primary endpoint was ongoing clinical success defined as successful implantation and freedom from aneurysm- or procedure-related death, secondary intervention, type I or III endoleak, infection, thrombosis, aneurysm expansion or rupture and conversion. Secondary endpoints were radiological changes of the branched endograft (migration, shortening, scoliosis, lordosis, and fracture).

RESULTS

After a median follow-up of 22.6 (LPSG) and 26.2 months (SPSG), no significant difference was found in terms of technical success (100% in both groups), late mortality (4.2% vs 0%), aneurysm diameter increase (4.2% in both groups) and reinterventions (25% vs 37.5%). Infection, thrombosis, aneurysm expansion or rupture and conversion were not observed. Radiological analysis of aortic graft remodeling showed no fracture and no significant migration, shortening, scoliosis and lordosis of the LPSG (6.1 mm, 7.5 mm, 12.8° and 6.1°) compared to SPSG (3.9 mm, 5.1 mm, 7.9° and 5.6°) after 2 years.

CONCLUSION

The clinical and radiological findings of the present study showed no increased mortality and complications for the matched patients who underwent treatment with low-profile vs standard-profile BEVAR. This study provides preliminary evidence of safety and efficacy of low-profile branched endografts in patients with demanding iliac access vessels.

Use of Gore C-TAG with active control to treat a complex infrarenal abdominal aortic aneurysm

Complex abdominal aortic aneurysms (AAAs) can preclude the use of endovascular aortic repair. In patients unable to undergo open surgical repair (OSR), the use of endografts outside the instructions for use might be the only option. We present the case of a woman with a highly angulated infrarenal AAA neck who was unsuitable for OSR and was successfully treated using a Gore C-TAG conformable thoracic stent graft (W.L. Gore and Associates, Inc, Flagstaff, Ariz) with active control, Medtronic Heli-FX EndoAnchors (Medtronic Vascular, Minneapolis, Minn), and a bifurcated Gore Excluder endoprosthesis W.L. Gore and Associates). The repair was successful without evidence of an endoleak. Using a thoracic endograft outside of the instructions for use to treat infrarenal AAAs might be feasible for patients unable to undergo OSR.

Endurant stent graft demonstrates promising outcomes in challenging abdominal aortic aneurysm anatomy

OBJECTIVE

We aimed to assess the 5-year safety and effectiveness outcomes of patients enrolled in the Endurant Stent Graft Natural Selection Global Post Market Registry (ENGAGE) who were treated outside the approved indications for use (IFU) of the Endurant stent graft.

METHODS

Our primary outcome measure was 12-month treatment success, defined as successful endograft delivery and deployment and the absence of type I or III endoleak, stent migration or limb occlusion, late conversion, and abdominal aortic aneurysm diameter increase or rupture. Secondary outcome measures included 30-day all-cause mortality, major adverse events, secondary procedures, technical observations, aneurysm-related mortality, and all-cause mortality within 12 months.

RESULTS

Demographic characteristics of ENGAGE patients treated outside (225 [17.8%]) and within (1038 [82.2%]) the IFUs were similar, except that female patients comprised a much higher percentage of the outside IFU group (19.1% vs 8.7%; P < .001). The outside IFU group presented with lower rates of coronary artery disease and cardiac revascularization and a greater number of symptomatic patients compared with the within IFU group (21.3% vs 15.0%; P = .020). Technical success was achieved in more than 99% of all patients. The outside and within IFU groups showed a comparable and low occurrence of uncorrected type I (0.9% vs 1.2%; P = 1.00) and type III endoleak (0.4% vs 0.3%; P = .54) immediately after device implantation. The 5-year freedom from type IA endoleaks was 89.4% vs 96.7% (P < .0001) for those patients outside and within the IFUs, respectively, although both groups had similar type III endoleaks through 5 years (P = .61). Stent graft limb occlusion estimated overall survival, and freedom from aneurysm-related mortality and endovascular interventions were comparable in both patient groups through the 5-year follow-up. The Kaplan-Meier estimates at 5 years showed a trend for low but increased need for type I or III endoleak correction procedures in the outside IFU group compared with the within IFU group (7.2% vs 5.2%; P = .099).

CONCLUSIONS

Differences were not observed in all-cause mortality, aneurysm-related mortality, and secondary procedures between within and outside IFU patients through a 5-year follow-up in the ENGAGE registry. Proximal necks with angulation or diameters outside the IFUs were the most common reasons for patients identified as being outside IFU, and the cohort had increased incidence of type IA endoleaks. Despite the challenges presented from the broad range of aortic and abdominal aortic aneurysm morphologies, the Endurant stent graft showed promising 5-year outcomes.

Contemporary Results of Endovascular Repair of Isolated Abdominal Aortic Dissection with Unibody Bifurcated Stent Grafts

OBJECTIVES

To report the midterm safety and efficacy of the Aegis™-B (Microport, Shanghai, China) unibody bifurcated stent graft for endovascular treatment of isolated abdominal aortic dissection (IAAD).

BACKGROUND

Isolated abdominal aorta dissection (IAAD) is a rare event. Endovascular stent grafts seem to offer an efficient therapeutic approach to treat IAAD. However, the relatively small diameter of the infrarenal aorta and aortic bifurcation remains the main anatomical limitation to endovascular repair.

METHODS

Between 2008 and 2015, we retrospectively evaluated 32 IAAD patients (21 men; mean age 58 ± 18 years), who underwent endovascular repair using Aegis™-B unibody bifurcated stent graft. Narrow proximal landing zone and narrow distal aorta was present in 11 (34.4%) patients and 10 (31.3%) patients, respectively. In the follow-up period, aortic remodeling was observed with computed tomography angiography.

RESULTS

All patients were treated by endovascular means, with a primary technical success rate of 100%. During a mean follow-up period of 30.71 ± 16.36 months (range, 8-56 months), no death, rupture, stent fracture, material failure, or device migration was observed. Complete false lumen thrombosis was observed in all patients at 1 year, and all patients were free from false lumen growth in the follow-up.

CONCLUSIONS

Endovascular treatment of IAAD using the Aegis™-B system appears to be safe and effective. Results from this study suggest this algorithm can provide stable, secure fixation for IAAD patients with narrow proximal landing zone, and distal aorta.

Mortality in endovascular and open abdominal aneurysm repair – trends in Germany

Abstract. Background: We analysed trends in mortality of endovascular (EVAR) and open aortic repair (OAR) in patients hospitalized for abdominal aortic aneurysms (AAA) in Germany from 2005 to 2015. Patients and methods: We used national statistics published by the Federal Statistical Office in Germany to calculate mortality rate of patients hospitalized with ruptured (rAAA, n = 2,448 in 2005, n = 2,180 in 2015) and non-ruptured (iAAA, n = 11,626 in 2005, n = 14,205 in 2015) AAA. Results: Considering only those who were treated with EVAR or OAR, treatment rates of iAAA with EVAR increased to 78.2 % in males and 72.6 % in females in 2015 and treatment rates of rAAA to 36.9 % and 40.7 %, respectively. In cases with iAAA, death rates associated with EVAR decreased in males from 2.1 to 1.1 % (p = 0.0005) in the period from 2005 to 2015 but not in females (1.8 % in 2005 and 2.3 % in 2015, p = 0.8511). Similar trends are seen in cases with rAAA (males 30.1 % and 24 %, p = 0.1034, females 36.4 to 37.3 %, p = 0.8511). Death rates associated with OAR increased in males from 4.7 % in 2005 to 5.7 % in 2015 (p = 0.0103) and tended to increase in females from 6.8 to 8.2 % (p = 0.1476). In cases of rAAA, there were no changes. EVAR treatment rates increased in cases with iAAA in both genders with age, as well as in males with rAAA, but not in females. OAR associated death rates increased with age in rAAA (from around 30 % in the sixth/seventh decade of life to almost 80 % in cases with patients over the age of 90) and in iAAA (from 1.1 to 20 %). Conclusions: The general increase in EVAR procedures in males and females hospitalized for rAAA and iAAA went along with a decrease in in-hospital mortality in males treated with EVAR for iAAA only and an increasing mortality in males treated with OAR for iAAA.

Endovascular vs Open AAA Repair: Does Size Matter?

Since the natural tendency of the aorta is to increase in diameter and tortuosity with age and since abdominal aortic aneurysms (AAAs) increase in diameter and length over time, encroaching on the renal and hypogastric orifices, early repair of AAAs (when =4.0 cm) may allow greater applicability of the endovascular option because of more favorable aortoiliac morphology. Patients who present at an older age with larger AAAs should be more likely to be anatomically excluded from endovascular AAA repair. Over a 42-month period, 317 consecutive patients referred with aortoiliac aneurysms (infrarenal AAA =4.0 cm) were evaluated by one of the authors (SGL) for endovascular vs open repair based on computed tomography (CT) and angiographic imaging. The 10 anatomic exclusion criteria were those applicable to the Zenith ® endograft (Cook, Inc), which currently is the most anatomically inclusive of the aortic endografts in commercial use in the United States. Based on their aortoiliac morphology, 212 patients were excluded from endovascular repair and 105 were included as acceptable anatomic candidates. Age, AAA size, and the reason(s) for exclusion were recorded for each patient. By use of Student's t test and logistic and linear regression analyses, the groups were compared by age, AAA size, and age + size. There was no significant difference in patient age or AAA size distribution between the group of patients excluded from endovascular repair based on aortoiliac morphology compared to those who met the inclusion criteria. Patients with small AAAs (4.0–5.4 cm) had similar age distribution as those with large (=5.5 cm) AAAs. The majority of patients (87%) were excluded based on proximal aortic neck morphology. The presence of aortoiliac morphology that precludes endovascular repair is independent of patient age or AAA size at presentation. A patient presenting with a small (4.0–5.4 cm) AAA is not more likely to be a candidate for endovascular repair than a patient with a large AAA.

Most Patients with Abdominal Aortic Aneurysm Are Not Suitable for Endovascular Repair Using Currently Approved Bifurcated Stent-Grafts

Strict morphologic criteria must be used for patient selection to achieve durable success with endovascular aortic aneurysm repair (EVAR). The goal of this study was to assess morphologic suitability (MS) of abdominal aortic aneurysms (AAAs) for 2 currently approved bifurcated stent grafts and identify reasons for exclusion from EVAR. The authors reviewed the electronic charts of 1,795 consecutive patients who were diagnosed as having AAA between January 1999 and July 2001 at their institution. Three hundred and twenty patients had an AAA with a diameter of =5.0 cm, measured on computed tomography (CT). The records of 301 patients, 254 men, 47 women, with a mean age of 74 years were available for review, and these patients constituted the study cohort. Criteria used for MS included a proximal neck length =15 mm; neck diameter between 18 and 26 mm; neck angulation =60°; common or external iliac artery (CIA or EIA) diameters of 7–16 mm and 8–13 mm, respectively, for AneuRx (Medtronic Ave, Santa Rosa, CA) and Ancure (Guidant Cardiac and Vascular Division, Menlo Park, CA) bifurcated grafts. AAAs were suitable for AneuRx device in 14% of patients (43 of 301; 95% CI = 11–19%) and for Ancure in 5% (16 of 301; 95% CI = 3.1–9%). The main reason for exclusion was an inadequate proximal aortic neck (73%). The neck was too short in 49.5%, too wide in 64% and badly angulated in 12% of the patients. Iliac artery morphology precluded EVAR with AneuRx and Ancure devices in 52% and 80%. Both CIAs were too wide for EVAR in 43% and 77%, respectively. When iliac artery diameter =20 mm was accepted, iliac suitability for AneuRx increased from 49% to 70% and overall suitability increased from 14% to 20%. When more permissive criteria were used for MS (neck length =10 mm, neck diameter =30 mm, CIA =20), 39% of patients became candidates for EVAR. More than three fourths of the patients with an AAA =5.0 cm in size, seen in a tertiary referral center, are morphologically not suitable for EVAR using 2 currently approved bifurcated endografts. The main reasons for exclusion are a short or wide proximal aortic neck. Considerable changes in size of the devices and in proximal attachment techniques have to occur before most AAAs will be suitable for EVAR.

Hormonal Stress Response and Hemodynamic Stability in Patients Undergoing Endovascular vs. Conventional Abdominal Aortic Aneurysm Repair

Background and Aims:

To investigate the effect of two different surgical techniques with different anesthetic modes on intraoperative and postoperative hormonal stress response, hemodynamic stability, fluid loading and renal function in patients scheduled for elective infrarenal abdominal aortic aneurysm (AAA) repair.

Materials and Methods:

Forty consecutive patients scheduled for elective infrarenal AAA repair were allocated without randomizing into two groups: an endovascular (EVAR, n=20) and a conventional (CAR, n=20) aneurysm repair group according to aneurysm morphology as determined by pre-operative computed tomography and angiography. The EVAR group were operated under spinal anesthesia and the CAR group using general anesthesia with epidural blockade.

Results:

Patients undergoing CAR showed lower intraoperative mean arterial pressure and significantly higher plasma norepinephrine before aortic cross-clamping and significantly higher lactate after aortic declamping and postoperatively than patients in the EVAR group. Postoperatively, vasopressin and serum cortisol were also significantly higher in the CAR group. Fluid loading and estimated blood loss were more excessive in the CAR group.

Conclusions:

Stress response was lower and hemodynamic stability and lower body perfusion superior and renal function also better maintained in patients undergoing EVAR under spinal anesthesia as compared to those undergoing CAR using general anesthesia with epidural blockade.

Iliac access conduit facilitates endovascular aortic aneurysm repair and ipsilateral iliofemoral bypass

It may be difficult to access a route to deliver a stent-graft for abdominal aortic aneurysm in high-risk patients with bilateral iliofemoral occlusive disease. These two patients underwent both endovascular aortic aneurysm repair by a modified iliac access conduit technique and sequential ipsilateral iliofemoral artery bypass using the conduit, which provided excellent results. The iliac access conduit facilitates endovascular aortic aneurysm repair and ipsilateral iliofemoral bypass of high-risk patients with abdominal aortic aneurysm and bilateral iliofemoral occlusive disease.

Reconstruction of the internal iliac artery in patients with aneurysmal disease: Two case reports

During the endovascular repair of aortoiliac aneurysm, bilateral internal iliac artery (IIA) occlusion may give rise to significant morbidities such as ischemia of buttock or sigmoid colon and erectile dysfunction. Open and endovascular approaches are used to maintain IIA circulation in such cases. The present report describes the cases of two patients who underwent external-to-internal iliac artery bypass surgery, one via a novel hybrid approach. The first patient had a right common iliac artery aneurysm without a sufficient distal landing zone for endovascular repair. The distal landing of the device was therefore placed in the right external iliac artery (EIA). The tortuous portion of the right EIA was excised and anastomosed in an end-to-end fashion. An external-to-internal iliac artery bypass was then performed. The second patient underwent endovascular repair of the IIA aneurysm with a Gore^® Viabahn^®-covered stent (W. L. Gore and Associates, Inc., Flagstaff, AZ, USA). This covered stent was anastomosed with the iliac bypass graft. Postoperative pelvic circulation was maintained. In conclusion, this strategy for maintaining IIA flow is a potential novel approach for future use.

Anatomic suitability for endovascular repair of abdominal aortic aneurysms and possible benefits of low profile delivery systems

The aim of the study was to evaluate the anatomic suitability for endovascular abdominal aneurysm repair (EVAR) according to instructions for use (IFUs) of three commercially available bifurcated stent graft devices and explore the possible benefits of low-profile delivery systems. Computed tomography scans of 241 patients with abdominal aortic aneurysm (AAA) were evaluated for suitability of Zenith Flex®, Gore Excluder® and Endurant® bifurcated stent graft systems according to their IFUs. The most common exclusion criteria and possible benefits of smaller diameter delivery systems were analyzed. When choosing the most suitable graft model for each patient, the overall suitability was 49.4%. By brand, the suitability was 28.6% for Zenith®, 25.7% for Gore Excluder® and 48.1% for Endurant®. By step wise accepting iliac diameters of ≥6 mm, ≥5 mm and ≥4 mm the overall suitability increased to 56.7, 58.9 and 60.2%, respectively ( P < 0.001). Diameters below 4 mm had no additional effect on suitability as combinations of other anatomical features, with or without narrow iliacs, accounted for the remaining excluding factors. In conclusion, Less than half of patients with AAAs are suitable for EVAR according to current IFUs. Low-profile delivery systems may allow for endovascular treatment in up to 60% of patients.

Clinical practice change requires more than comparative effectiveness evidence: abdominal aortic aneurysm management in the USA

Adoption of healthcare innovations frequently outpaces the evidence of effectiveness. Endovascular repair (EVAR) for abdominal aortic aneurysms in the USA demonstrates how comparative effectiveness research without evidence-based reimbursement changes may fail to influence clinical practice. Randomized controlled trials for small abdominal aortic aneurysms demonstrate no lasting benefits of EVAR or open surgical repair (OSR) compared with surveillance, and for large abdominal aortic aneurysms demonstrate no lasting survival benefit of EVAR over OSR, and do show poorer durability and higher costs for EVAR. Nonetheless, >50% of elective abdominal aortic aneurysm repairs in the USA use EVAR. Factors that may be driving the high use of EVAR include patient preference, surgeons’ desire to appear ‘up-to-date’ in the procedures they offer, higher hourly surgeon reimbursement for EVAR than OSR, and the expansion of physician specialties able to perform abdominal aortic aneurysm repair from only vascular surgeons with OSR, to vascular surgeons and interventional radiologists/cardiologists with EVAR. By comparison, in Canada, where government health insurance restricts EVAR coverage to high surgical risk patients, only approximately 25% of abdominal aortic aneurysm repairs are performed using EVAR. Country-specific cost studies and a prospective population-based study collecting detailed clinical data to identify patient subgroups that truly benefit from a particular management strategy are needed to inform policy regarding EVAR availability and reimbursement.

Elective open abdominal aortic aneurysm repair: a seven-year experience

Introduction

The seven-year experience of elective abdominal aortic aneurysm (AAA) repair of a vascular surgical unit in a teaching hospital was reviewed to determine the factors associated with in-hospital mortality.

Methods

All patients who underwent elective open repair of an AAA between July 1, 1991, and June 30, 1998, were identified using International Classification of Diseases Ninth Revision (ICD-9) codes. Twenty-four variables were selected for investigation by reviewing the published literature and by discussion with local vascular surgeons. Data were obtained by retrospective medical record review. Variables were first analysed by univariate analysis, and those with a p-value up to 0.25 were included in multivariate analysis.

Results

Of the 219 patients reviewed, 8 (3.7%, 95% confidence interval, 1.6%, 7.1%) died during the admission. The mean age of patients was 69.9 years, and 81% of them were male. Univariate analysis found that female sex, renal artery involvement in the aneurysm, and aortic cross-clamp duration of 90 min or greater were significantly associated with mortality. Multivariate analysis found that female sex, use of a bifurcated graft, and performance of an additional procedure at the time of operation were the only variables independently associated with mortality.

Discussion

Use of a bifurcated graft was a significant prognostic variable on logistic regression analysis confirming that the technical difficulty of the operation and the morphology of the aneurysm are important factors in determining mortality. Why women may be at higher risk for death is unclear. This study also highlights that caution is required when interpreting raw audit data.

Use of baseline factors to predict complications and reinterventions after endovascular repair of abdominal aortic aneurysm

BACKGROUND

It is uncertain which baseline factors are associated with graft-related complications and reinterventions after endovascular aneurysm repair (EVAR) in patients with a large abdominal aortic aneurysm.

METHODS

Patients randomized to elective EVAR in EVAR Trial 1 or 2 were followed for serious graft-related complications (type 2 endoleaks excluded) and reinterventions. Cox regression analysis was used to investigate whether any prespecified baseline factors were associated with time to first serious complication or reintervention.

RESULTS

A total of 756 patients who had elective EVAR were followed for a mean of 3.7 years, by which time there were 179 serious graft complications (rate 6.5 per 100 person years) and 114 reinterventions (rate 3.8 per 100 person years). The highest rate was during the first 6 months, with an apparent increase again after 2 years. Multivariable analysis indicated that graft-related complications increased significantly with larger initial aneurysm diameter (P < 0.001) and older age (P = 0.040). There was also evidence that patients with larger common iliac diameters experienced higher complication rates (P = 0.011).

CONCLUSION

Graft-related complication and reintervention rates were common after EVAR in patients with a large aneurysm. Younger patients and those with aneurysms closer to the 5.5-cm threshold for intervention experienced lower rates.

Contemporary management of the infra-renal abdominal aortic aneurysm

Abdominal aortic aneurysms (AAAs) principally affect men over 60 years of age. Aneurysms are usually asymptomatic and detected coincidentally or following the onset of symptoms. Elective repair of an AAA is considered when the diameter reaches 5.5cm or annual expansion exceeds 1 cm. Rupture represents a catastrophic event and carries an unacceptably high mortality. The advent of endovascular repair heralds an improvement in operative outcome for this disease process. In this review we provide an overview of the recent trials investigating the management of non-ruptured and ruptured aneurysms and the strategies that may be invoked to lower the mortality of this disease process

Access for Endovascular Aneurysm Repair

Despite advancement in stent-graft technology, access-related problems continue to occur during endovascular repair of aortic aneurysms. Various techniques have been adopted to overcome difficult access situations, however. To survey these developments in arterial access, we performed a systematic literature review from 1994 through 2005 to identify relevant articles pertaining to endovascular access techniques and complications. Excessive iliac tortuosity, circumferential vessel wall calcification, significant occlusive disease, and small caliber vessels account for the majority of access problems, most of which are readily apparent with adequate baseline imaging. Even with careful preoperative assessment, however, some access problems may not be foreseen; nonetheless, the majority can be overcome using today's array of ancillary procedures, such as an iliac conduit, a brachiofemoral wire, or arterial reconstruction. Alternatively, other approach routes, such as the common carotid artery or direct aortic access, may be used to facilitate endovascular aneurysm repair.

Propensity score analysis in observational studies: outcomes after abdominal aortic aneurysm repair

OBJECTIVE

Large databases composed of well-designed prospectively collected cohort data provide an opportunity to examine and compare healthcare treatments in actual clinical practice settings. Because the analysis of these data often leads to a retrospective cohort design, it is essential to adequately adjust for lack of balance in patient characteristics when making treatment comparisons. We used matched propensity scoring in a cohort of patients undergoing elective aneurysm repair as an illustrative example of this important statistical method that adjusts for baseline characteristics and selection bias by matching covariables.

METHODS

By using prospectively collected clinical data from the National Surgical Quality Improvement Program of the Department of Veterans Affairs, we studied 30-day mortality, 1-year survival, and postoperative complications in 1904 patients who underwent elective AAA repair (endovascular aneurysm repair [EVAR], n=717 (37.7%); open aneurysm repair, n=1187 [62.3%]) at 123 Veterans Health Administration's hospitals between May 1, 2001, and September 30, 2003. In bivariate analysis, patient characteristics and operative and hospital variables were associated with both type of surgery and outcomes of surgery. Therefore, the predicted probability of receiving EVAR was tabulated for all patients by using multiple logistic regression to control for 32 independent demographic and clinical characteristics and then stratified into 5 groups. Patients were matched within strata based on similar levels of the independent measures (a propensity score technique), creating a pseudo-randomized control design. The proportion of patients with the morbidity and mortality outcomes was then compared between the EVAR and open procedures within strata to control for selection.

RESULTS

Patients undergoing EVAR had significantly lower unadjusted 30-day (3.1% versus 5.6%, P=.01) and 1-year mortality (8.7% versus 12.1%, P=.018) than patients undergoing open repair. By using propensity scoring, the proportions of EVAR patients experiencing 30-day mortality were equal or less than patients undergoing open procedures for all levels of probability and decreased as the probability of EVAR increased. Furthermore, propensity scoring also showed that patients having EVAR had lower 1-year mortality and experienced fewer perioperative complications.

CONCLUSIONS

We used a propensity score approach to examine outcomes after elective AAA repair to statistically control for many factors affecting both treatment selection and outcome. Patients who underwent elective EVAR had substantially lower perioperative mortality and morbidity rates compared with patients having open repair, which was not explained solely by patient selection in an observational dataset.

Open Versus Endovascular Abdominal Aortic Aneurysm Repair in VA Hospitals

BACKGROUND

Endovascular abdominal aortic aneurysm repair (EVAR), when compared with conventional open surgical repair, has been shown to reduce perioperative morbidity and mortality. We performed a retrospective cohort study with prospectively collected data from the Department of Veterans Affairs to examine outcomes after elective aneurysm repair.

STUDY DESIGN

We studied 30-day mortality, 1-year survival, and postoperative complications in 1,904 patients who underwent elective abdominal aortic aneurysm repair (EVAR n=717 [37.7%]; open n=1,187 [62.3%]) at 123 Department of Veterans Affairs hospitals between May 1, 2001 and September 30, 2003. We investigated the influence of patient, operative, and hospital variables on outcomes.

RESULTS

Patients undergoing EVAR had significantly lower 30-day (3.1% versus 5.6%, p=0.01) and 1- year mortality rates (8.7% versus 12.1%, p=0.018) than patients having open repair. EVAR was associated with a decrease in 30-day postoperative mortality (adjusted odds ratio[OR]=0.59; 95% CI=0.36, 0.99; p=0.04). The risk of perioperative complications was much less after EVAR (15.5% versus 27.7%; p<0.001; unadjusted OR 0.48; 95% CI=0.38, 0.61; p<0.001). Patients operated on at low volume hospitals (25% of entire cohort) were more likely to have had open repair (31.3% compared with 15.9% EVAR; p<0.001) and a nearly two-fold increase in adjusted 30-day mortality risk (OR=1.9; 95% CI=1.19, 2.98; p=0.006).

CONCLUSIONS

In routine daily practice, veterans who undergo elective EVAR have substantially lower perioperative mortality and morbidity rates compared with patients having open repair. The benefits of a minimally invasive approach were readily apparent in this cohort, but we recommend using caution in choosing EVAR for all elective abdominal aortic aneurysm repairs until longer-term data on device durability are available.

Midterm Survival After Endovascular Versus Open Repair of Infrarenal Aortic Aneurysms

PURPOSE

To report the midterm survival after endovascular repair (ER) of infrarenal aortic aneurysms and to compare the outcomes to contemporaneous patients treated with open repair (OR).

METHODS

Between January 1995 and December 2001, 498 patients were treated for abdominal aortic aneurysm: 289 (52%) underwent OR and 209 (48%) underwent ER at a single center. Preoperative risk factors were graded according to the SVS/AAVS risk stratification. A computerized database was used to record demographic, clinical, and follow-up data.

RESULTS

Significant benefits (p<0.0001) were observed in the ER group in terms of mean procedural time (163+/-66 versus 132+/-61 minutes), mean blood loss (1268+/-923 versus 122.5+/-284 mL), and mean hospital length of stay (16.24+/-13.3 versus 9.3+/-11.6 days). The perioperative mortality for OR and ER patients were, respectively, 5.1% and 1.5% (p=0.04). The mean follow-up was 40 months in the OR group (range 0-85) and 19 months in the ER group (range 2-80). Contact was lost with 31 (6%) patients during the study. No overall survival advantage was observed for OR over ER, and comparison of OR and ER according the risk classifications did not yield any significant differences. No patients died of aneurysm rupture, but 7 ER patients had to be converted to open surgery. The cumulative freedoms from reinterventions at 4 years for the OR and ER groups, respectively, were 87% and 63% (p=0.001). Patients treated by OR had better clinical success (p=0.001). Patients in the ER group without iliac artery aneurysm showed a significant improvement (p=0.035) over patients with aneurysmal iliac arteries.

CONCLUSIONS

Over the 7 years of this study, ER realized its goal: prevention of aneurysm rupture. Despite a greater number of reinterventions for ER patients, no overall survival difference was observed.

Suitability of Ruptured AAA for Endovascular Repair

PURPOSE

To determine the anatomical suitability and the range of endografts required to undertake an endovascular repair (EVR) program for ruptured abdominal aortic aneurysms.

METHODS

The morphology of ruptured and nonruptured AAAs were compared by retrospective review of computed tomographic scans from 51 patients (47 men; mean age 76 years, range 55-90) with ruptured AAAs and 50 patients (37 men; mean age 74 years, range 57-75) with nonruptured AAAs. Three experienced clinicians reviewed the scans for EVR suitability based on a generic trimodular endograft with suprarenal fixation. Endograft oversizing was assumed to be 10% to 20%.

RESULTS

Interobserver agreement was high, with a mean kappa of 0.78 (range 0.75-0.83, p<0.001). In all, 41% of ruptured and 68% of nonruptured AAAs were suitable for EVR (p=0.009). Ruptured AAAs had shorter mean neck lengths (17+/-12 versus 22+/-11 mm, p=0.031) and larger mean aneurysm diameters (75+/-15 versus 63+/-9 mm, p>0.001). Neck length and neck diameter were significantly correlated for ruptured AAAs (r=-0.34, p=0.018). The main contraindication to EVR was hostile neck morphology. A range of endografts with aortic components from 24 to 32 mm and iliac components from 12 to 22 mm would be required to stent 41% of ruptured AAAs.

CONCLUSIONS

Ruptured AAAs are less suitable for EVR due to differing neck morphology. An EVR program for ruptured AAA requires an inventory of endografts with appropriate aortic and iliac components.

Four-year follow up of patients with untreated abdominal aortic aneurysms

BACKGROUND

The data in the literature are still controversial describing the outcome of patients not treated for a large abdominal aortic aneurysm (AAA) especially with significant comorbidities. We followed up patients trying to establish their long-term outcome.

METHOD

Since 1998, we have prospectively followed all patients referred to our department with AAA. A retrospective analysis was carried out selecting all patients who had an AAA larger than 5 cm, and who declined or were declined for operative repair between February 1998 and November 2001.

RESULTS

One hundred and eleven patients were included in the present study. There were 78 men and 33 women. The mean age was 80 years. At the end of the study, 65 patients (59%) were deceased. Ruptured aneurysm occurred in 27 patients (median time to rupture = 14 months) with one patient surviving an emergency repair. Thirty-nine patients died from unrelated illnesses. In the 5-5.9 cm AAA group (n = 58), out of 31 deceased patients, five (16%) have died of ruptured AAA. In the 6 cm and larger AAA group (n = 53), out of 34 deceased patients, 21 (62%) have died of ruptured AAA. There was no significant difference in survival between patients with AAA below and above 6 cm in diameter (P = 0.15).

CONCLUSION

In the presence of significant comorbidities, most patients with AAA less than 6 cm died from unrelated illnesses. In the larger AAA group, the likelihood of death from AAA rupture or unrelated illnesses is almost equal.

Comparison of endovascular aneurysm repair with open repair in patients with abdominal aortic aneurysm (EVAR trial 1), 30-day operative mortality results: randomised controlled trial

BACKGROUND

Endovascular aneurysm repair (EVAR) is a new technology to treat patients with abdominal aortic aneurysm (AAA) when the anatomy is suitable. Uncertainty exists about how endovascular repair compares with conventional open surgery. EVAR trial 1 was instigated to compare these treatments in patients judged fit for open AAA repair.

METHODS

Between 1999 and 2003, 1082 elective (non-emergency) patients were randomised to receive either EVAR (n=543) or open AAA repair (n=539). Patients aged at least 60 years with aneurysms of diameter 5.5 cm or more, who were fit enough for open surgical repair (anaesthetically and medically well enough for the procedure), were recruited for the study at 41 British hospitals proficient in the EVAR technique. The primary outcome measure is all-cause mortality and these results will be released in 2005. The primary analysis presented here is operative mortality by intention to treat and a secondary analysis was done in per-protocol patients.

FINDINGS

Patients (983 men, 99 women) had a mean age of 74 years (SD 6) and mean AAA diameter of 6.5 cm (SD 1). 1047 (97%) patients underwent AAA repair and 1008 (93%) received their allocated treatment. 30-day mortality in the EVAR group was 1.7% (9/531) versus 4.7% (24/516) in the open repair group (odds ratio 0.35 [95% CI 0.16-0.77], p=0.009). By per-protocol analysis, 30-day mortality for EVAR was 1.6% (8/512) versus 4.6% (23/496) for open repair (0.33 [0.15-0.74], p=0.007). Secondary interventions were more common in patients allocated EVAR (9.8% vs 5.8%, p=0.02).

INTERPRETATION

In patients with large AAAs, treatment by EVAR reduced the 30-day operative mortality by two-thirds compared with open repair. Any change in clinical practice should await durability and longer term results.

Treatment of short-necked infrarenal aortic aneurysms with fenestrated stent-grafts: short-term results

INTRODUCTION

A proximal neck of 15 mm length is usually required to allow endovascular repair of abdominal aortic aneurysms (EVAR). Many patients have been refused EVAR due to a short neck. By customising fenestrated grafts to the patients' anatomy, we can offer an endovascular solution, especially for patients who are unsuitable for open repair.

METHODS

Eighteen patients were selected for fenestrated stent-grafting if they presented with an abdominal aneurysm of at least 55 mm in diameter, a short neck (less than 15 mm), plus contra-indications for open repair (cardiopulmonary impairment or a hostile abdomen). The stent-graft used was a customised fenestrated model based on the Cook Zenith composite system. We used additional stents to ensure apposition of the fenestrations with the side branches.

RESULTS

All endovascular procedures were successful. Out of the 46 targeted side branches (10 superior mesenteric arteries, 36 renal arteries), 45 were patent at the end of the procedure. One accessory renal artery became occluded by the stent-graft. There was one possible proximal type I endoleak, which later proved to be a type II endoleak. There was no mortality, but complications occurred in six patients: two cardiac complications, three urinary complications and one occlusion of a renal artery. At follow-up (mean 9.4 months, range 1-18), there were no additional renal complications and all the remaining targeted vessels stayed patent.

DISCUSSION

By customizing fenestrated stent-grafts, it is possible to position the first covered stent completely inside the proximal neck, thus achieving a more stable position. The additional side-stents may also contribute to a better fixation. This technique may become a valuable alternative for patients who are at high risk from open surgery.

Intraoperative management: endovascular stents

This article discusses the current state of minimally invasive treatment options for a variety of vascular diseases. Advances that have been introduced over the last two decades have dramatically changed the practice of vascular surgery and anesthesia. The ability to treat pathology, using both intraluminal and extraluminal means,has provided vascular surgeons, interventional radiologists, and cardiologists with unique treatment options that were not available less than a decade ago. Peripheral interventions to treat vascular disease have exploded, from 90,000 in 1994 to more than 200,000 in 1997, and endovascular procedures now replace almost 50% of traditional open vascular operations.

Ruptured abdominal aortic aneurysm: endovascular treatment

BACKGROUND

This report describes our preliminary experience in endovascular management of 25 ruptured abdominal aortic aneurysms (rAAAs).

METHODS

In the past 3 years we treated 46 patients who had rAAA, and 25 (54.3%) were treated with an endovascular approach. Patients' mean age was 76 +/- 9 years. The diagnosis was confirmed by computed tomographic angiography in 23 patients (92%). Mean aneurysm diameter was 73 +/- 17 mm. We used an infrarenal bifurcated device in 17 patients (68%), a suprarenal bifurcated in four patients (16%), and an aortomonoiliac graft in four patients (16%). Overall, nine patients (36%) required intensive care. Every patient underwent radiologic follow-up according to the Eurostar register, with concomitant evaluation of the D-dimer level (cut-off <200 microg/L) as a biological marker for endoleaks.

RESULTS

The primary technical success rate was 100%. Overall in-hospital mortality rate was 20%. Mean hospitalization was 7 days (range, 3-30), and mean follow-up was 7 months. One occlusion (4%) of the iliac limb and two type II endoleaks (8%) occurred. The mean D-dimer level in type I endoleak was 1045 microg/L (range, 459-2021).

CONCLUSIONS

In our experience, endovascular management of rAAA is feasible and safe and produces better results than conventional surgery, provided the morphology is suitable and the procedure is carried out by an experienced endovascular team.

Endovascular aneurysm repair with a bifurcated endovascular graft at a primary referral center: Influence of experience, age, gender, and aneurysm size on suitability

OBJECTIVE

The purpose of this study was to assess the suitability for endovascular repair of abdominal aortic aneurysm (EVAR) in an unselected patient population.

PATIENTS AND METHODS

Between February 1999 and May 2002 all consecutive patients with a nonemergent abdominal aortic aneurysm (AAA) were prospectively examined with contrast material-enhanced spiral computed tomography (CT). Those patients probably suitable for EVAR on the basis of CT findings underwent calibrated angiography. A panel of radiologists and vascular surgeons reviewed the clinical data and vascular anatomy, and decided on the appropriateness of EVAR with the bifurcated Zenith AAA endovascular graft.

RESULTS

One hundred seven patients were included. Fifty-six patients (52%) had one or more contraindications for EVAR. Unsuitability was most frequently (88%) related to the proximal neck. Inadequate neck length was the most common specific reason. Inadequate iliac anatomy was the reason for unsuitability in 59% of patients. The rate of unsuitability decreased from 61% during the first half of the study to 40% during the second half (P =.03) Unsuitability was equal between men and women. Age and maximum diameter did not differ between candidates and noncandidates.

CONCLUSION

Almost half (48%) of patients with an infrarenal AAA referred to a primary referral center are suitable for EVAR with the bifurcated Zenith AAA endovascular graft. Neck anatomy was the most frequent reason for rejection. Rate of suitability increased over time, probably as a result of increasing experience. Suitability was not influenced by gender, age, or aneurysm size.

Morbidity with retroperitoneal procedures during endovascular abdominal aortic aneurysm repair

PURPOSE

Retroperitoneal iliac procedures can enable successful endovascular repair of abdominal aortic aneurysm (AAA) in patients who otherwise would not be anatomically eligible. The purpose of this study was to determine perioperative outcome with adjunctive retroperitoneal procedures compared with standard bilateral femoral exposure.

METHODS

Between August 1997 and November 2002, 164 patients underwent elective endovascular AAA repair at a single university medical center. Anatomic, demographic, and early postoperative outcome data gathered prospectively were analyzed. Thirty-two patients (20%) underwent 38 separate adjunctive retroperitoneal procedures. Indications included small external iliac arteries (16 of 32 patients; 50%) and concomitant iliac aneurysm that precluded fixation of the endograft limbs in the common iliac arteries (16 of 32 patients; 50%). The 38 procedures consisted of 8 iliac conduits only, 14 iliac conduits with iliofemoral bypass grafts, and 16 hypogastric revascularization procedures. Data for the study patients were compared with data for 132 patients who underwent endovascular AAA repair through femoral incisions. Primary end points were hospital length of stay, and early morbidity and mortality.

RESULTS

Retroperitoneal procedures enabled an additional 14% of patients with AAA to undergo endovascular techniques. However, there was a significantly higher proportion of women and patients at high risk for anesthesia (American Society of Anesthesiologists class IV or higher) in the group who underwent retroperitoneal procedures. On average, retroperitoneal procedures were associated with 2.6-fold greater blood loss, 82% longer procedure time, 1.5 days additional hospital stay, and 1.8-fold higher rate of perioperative complications, compared with endovascular AAA repair with femoral exposure alone. In contrast, early mortality was similar in the two groups.

CONCLUSION

Adjunctive retroperitoneal procedures during endovascular AAA repair are associated with increased risk for complications and longer hospital length of stay, compared with AAA repair with standard femoral exposure only. They do not, however, increase early mortality, even in patients at high risk, and enable a larger subset of patients with AAA to undergo endovascular repair.

Comparison of morphologic features of intact and ruptured aneurysms of infrarenal abdominal aorta

INTRODUCTION

Endovascular aneurysm repair (EVAR) has been suggested as a technique to improve outcome of ruptured abdominal aortic aneurysm (AAA). Whether this technique becomes an established treatment will depend, in part, on the anatomy of ruptured AAA.

METHODS

The anatomy of intact and ruptured AAA seen in a university department of vascular surgery over 5 years was reviewed. Aneurysm anatomy was assessed with spiral computed tomographic angiography. Suitability for EVAR was assessed from the dimensions of the proximal neck and common iliac arteries. Neck length less than 15 mm, neck width greater than 30 mm, and common iliac artery diameter greater than 22 mm were declared unsuitable for EVAR.

RESULTS

Three hundred sixty-three patients with intact AAA and 46 with ruptured AAA were identified. Larger intact aneurysms were significantly associated with longer renal artery-bifurcation distance and more complex proximal neck architecture. In this sample, patients with ruptured AAA were more likely to have larger aneurysms with shorter and narrower proximal necks. Significantly more intact aneurysms were morphologically suitable for endovascular repair compared with ruptured AAA (78% vs 43%; P <.001).

CONCLUSIONS

Ruptured AAA are less likely to be suitable for endovascular repair than are intact AAA, most probably because of larger diameter at presentation. Open repair will likely remain the treatment of choice in most patients with ruptured AAA, because of current morphologic constraints of endovascular repair.

The endovascular management of ruptured abdominal aortic aneurysms

Endovascular aneurysm repair (EVAR) is a controversial technique, which remains the subject of a number of prospective randomised trials. Although questions remain regarding its long-term durability objective evidence exists which demonstrates its reduced physiological impact compared with conventional open repair. If this technique could be used in patients with ruptured abdominal aortic aneurysm (AAA) it may reduce the high peri-operative mortality. A review of the literature identified a limited experience with EVAR of ruptured AAA. Only a small number of case series with selected patients exist. The majority of patients were haemodynamically stable. However, the selective use of aortic occlusion balloons allowed successful endovascular management in a small number of unstable cases. All investigators had access to an "off the shelf" endovascular stent-graft (EVG). Per-operative mortality ranged from 9 to 45% and may reflect increasing experience and patient selection. A number of patients who underwent successful EVAR were turned down for open repair. A number of important lessons have been learned from these studies but questions remain regarding patient suitability and staffing issues. If these difficulties can be surmounted then the technique may offer an alternative to open repair.

Endovascular repair of acute AAAs under local anesthesia with bifurcated endografts: a feasibility study

PURPOSE

To evaluate endovascular repair of abdominal aortic aneurysms (AAA) under local anesthesia in the acute setting.

METHODS

Between 1998 and 2001, 47 patients with an acute AAA were evaluated for endovascular repair after informed consent, provided they were in a stable, albeit hypotensive condition. The patients underwent urgent computed tomography to assess suitability for endovascular repair; 16 were eligible for stent-graft repair: 9 were frank ruptures and 7 were symptomatic aneurysms. Complications and outcome of endovascular repair were evaluated; mortality was compared to a contemporaneous surgical cohort.

RESULTS

Seven (23%) of 31 patients having a standard surgical procedure died in the study period compared to 1 (6%) of 16 patients undergoing endovascular repair (following conversion to surgery because of calcified access vessels). Twelve (75%) of the endovascular repairs were performed under local anesthesia; no complications with this mode of anesthesia were encountered. The median duration of the endovascular procedures was 110 minutes (range 75-240); median blood loss was 250 mL (range 100-2800 mL). Only 4 patients required blood transfusion, and only 8 patients required admission to the intensive care unit. There were 3 postoperative complications (1 ischemic colitis, 1 renal failure, 1 groin hematoma). During follow-up, 3 endograft patients received stent-graft extensions in uneventful procedures. Two patients died at 9 and 16 months from cardiac causes.

CONCLUSIONS

This study demonstrates the feasibility and possible advantages of endovascular repair under local anesthesia in selected acute AAA patients. Further studies are needed to prove the advantages over open repair.

A hybrid endovascular procedure to preserve internal iliac artery patency during endovascular repair of aortoiliac aneurysms

PURPOSE

To demonstrate the feasibility of a hybrid endovascular procedure to preserve blood flow in the internal iliac arteries (IIA) during aortoiliac endografting.

TECHNIQUE

When aneurysmal dilatation makes the distal neck in the common iliac artery (CIA) too short for an adequate seal, the CIA bifurcation is exposed via an extraperitoneal approach after endograft deployment. Via an arteriotomy in the CIA, the distal end of the stent-graft is sutured to the CIA bifurcation under direct vision to preserve IIA blood flow. This approach has been successful in preserving IIA blood flow in 5 of 7 endograft procedures; in the other 2, IIA occlusion was a predictable event.

CONCLUSIONS

Direct suturing of an aortoiliac stent-graft to the CIA bifurcation via an extraperitoneal approach is a useful method of maintaining IIA perfusion. However, further study is required to identify patients at high risk of pelvic ischemia who would benefit from such intervention.

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.

Internal iliac artery revascularization as an adjunct to endovascular repair of aortoiliac aneurysms

PURPOSE

Endovascular repair of aortoiliac aneurysms may be limited by extension of the aneurysm to the iliac bifurcation, necessitating endpoint implantation in the external iliac artery. In such cases the circulation to the internal iliac artery is interrupted. Bilateral internal iliac artery occlusion during endovascular repair may be associated with significant morbidity, including gluteal claudication, erectile dysfunction, and ischemia of the sigmoid colon and perineum. We have employed internal iliac artery revascularization (IIR) to allow endograft implantation in the external iliac artery while preserving flow to the internal iliac artery in patients with aneurysms involving the iliac bifurcation bilaterally.

METHODS

A total of 11 IIR procedures were performed in 10 patients undergoing endovascular abdominal aortic aneurysm (AAA) repair (9 men, 1 woman; mean age, 74 years). IIR was accomplished via a retroinguinal incision in 9 cases and a retroperitoneal incision in 2 cases. Six-mm polyester grafts were used for external-to-internal iliac artery bypass in 10 cases and internal iliac artery transposition onto the external iliac artery was used in one case. Endovascular AAA repair was performed using a modular bifurcated device (Talent-LPS, Medtronics, Minneapolis, Minn) after IIR. Bypass graft patency was determined immediately after the surgery, at 1 month, and every 3 months thereafter, using duplex ultrasound scanning and computed-tomography angiography. Mean aneurysm diameters were as follows: AAA, 6.4 +/- 0.7 cm; ipsilateral common iliac, 3.7 +/- 1.0 cm; contralateral common iliac, 3.9 +/- 0.8 cm.

RESULTS

Successful IIR and endovascular AAA repair were accomplished in all cases. No proximal, distal, or graft junction endoleaks occurred. Two patients demonstrated retrograde aneurysm side-branch endoleaks originating from the lumbar arteries. One thrombosed spontaneously within 3 months. One perioperative myocardial infarction occurred. Reduction in aneurysm size was documented in 5 aortic, 5 ipsilateral iliac, and 3 contralateral iliac aneurysms. Gluteal claudication, erectile dysfunction, colon and perineal ischemia, and mortality did not occur. All IIRs have remained patent during a follow-up period of 4 to 15 months (mean, 10.1 months).

CONCLUSIONS

IIR may be used with good short-term to intermediate-term patency to prevent pelvic ischemia in patients whose aneurysm anatomy requires extension of the endograft into the external iliac artery. This may allow endovascular AAA repair to be performed in patients who might otherwise be at risk for developing complications associated with bilateral internal iliac artery occlusion.