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

Laparoscopic aortic reinforcement and endovascular graft placement in swine: a new external wrap

OBJECTIVE

To evaluate the feasibility, safety, and histological response of laparoscopic external aortic wrap implantation in conjunction with an endovascular stent/stent-graft placement in the infrarenal aorta in a porcine model.

METHODS

Seven swine underwent laparoscopic retroperitoneal placement of a custom-made Dacron fabric wrap placed around the infrarenal aorta to create a landing zone for an endovascularly placed aortic stent/stent-graft.

RESULTS

Technical success was achieved in all animals without any major complications. Follow-up ranged from 1 to 4 weeks. At necropsy, the external wraps were well incorporated into the adventitia, and the stents/stent-grafts were well incorporated into the intima. Small patches of medial necrosis of the aortic wall were observed in one animal in the stent model and in two animals in the stent-graft model. There was no transmural necrosis observed. CONCLUSIONS This adjunct technique, an external wrap around the infrarenal aorta combined with endovascular grafting, is feasible and deserves further studies into how it may be used to facilitate endovascular repair of aortic aneurysms.

CLINICAL RELEVANCE

We hypothesize that our new device could provide capability of altering the proximal neck morphology of abdominal aortic aneurysm and reinforcement to the aortic wall. This, in turn, could improve eligibility for endovascular aneurysm repair and prevent or treat type I endoleak and graft migration. Future investigations will involve evaluation of the long-term effect of the external aortic wrap on the integrity of the aortic wall in an animal model and testing the clinical usefulness of this new technique.

Treatment possibility for AAA of the visceral branches region

The authors describe a promising abdominal aortic aneurysm treatment--a combined endovascular/surgical approach--used in two cases of aneurysm taking the aortic visceral branches region.

Endovascular AAA Repair With the Aortomonoiliac EndoFit Stent-Graft: Two Years' Experience

PURPOSE

To evaluate the feasibility and efficacy of a specific aortomonoiliac endograft and the durability of the femorofemoral bypass for treatment of abdominal aortic aneurysm (AAA).

METHODS

From 2002 to 2004, 39 high-risk (ASA III/IV) patients (36 men; median age 74 years, range 63-84) with AAA (n = 33) or AAA and common iliac artery aneurysm (n = 6) were treated with an EndoFit aortomonoiliac endograft and femorofemoral crossover bypass. The contralateral iliac axis was obstructed with an endoluminal occluder. Patients were followed with contrast-enhanced computed tomography at 1, 6, 12, and 24 months.

RESULTS

EndoFit AMI stent-grafts were implanted successfully in all patients. Perioperative mortality was zero. Endoleak occurred in 3 (7.7%) cases. A proximal type I endoleak was identified at 1 month and was treated with a proximal cuff. Two type II endoleaks are under surveillance because the aneurysm sac shows no enlargement. Thrombosis of the femorofemoral graft occurred in 1 case during the immediate postoperative period due to insufficient inflow from a residual stenosis of the endograft (primary patency 97.5%). The deficit was treated successfully (secondary patency 100%). Two (5.1%) tunnel hematomas were treated conventionally. Median follow-up was 14 months (range 6-30). All patients are alive. None of the aneurysms has ruptured or been converted to an open procedure. Graft migration, serious infection, paraplegia, distal embolization, or any other serious complication has not been observed.

CONCLUSIONS

In high surgical risk patients with complex iliac anatomy, aortomonoiliac endograft with femorofemoral crossover bypass is feasible and efficacious. Moreover, the midterm patency of the extra-anatomic bypass appears quite satisfactory.

Reducing complications by better case selection: anatomic considerations

The feasibility of endovascular aortic aneurysm repair (EVAR) in any individual patient remains inherently dependent on the anatomy of the aorta and iliac arteries. There is a great deal of evidence in the literature that poor anatomic patient selection for EVAR will increase the risk of both procedure-related complications and compromised long-term outcomes. Inferior outcomes can include technical failures such as attachment-site endoleak, endograft migration, and ultimately aneurysm growth and rupture. Unfortunately, it is relatively rare to encounter a patient who possesses completely "ideal" anatomy for this technique. With the broadening spectrum of new devices applicable for the intraluminal treatment of abdominal aortic aneurysms, the vascular surgeon is challenged to be aware of individual selection criteria for the ever-widening variety of endoluminal grafts, in order to choose the optimal device for each patient's distinct anatomical situation. In patients who would otherwise be at high risk for traditional abdominal aortic aneurysm surgery based on medical comorbidities, the additional challenge for the practitioner who performs EVAR is to possess excellent judgment regarding just how far the anatomical "envelope" may be pushed without compromising patient outcomes.

Suprarenal Endograft Fixation Avoids Adverse Outcomes Associated with Aortic Neck Angulation

The advent of endovascular therapy has had a profound impact on repair of abdominal aortic aneurysms (AAA). Prudent patient selection, particularly in regard to unfavorable anatomy, is emerging as perhaps the most important determinant of endovascular abdominal aortic aneurysm repair (EVAR) outcome. The aim of this study was to examine the association of one such anatomic factor, proximal aortic neck angulation, with the incidence of adverse events following EVAR. Prospectively collected data on 289 EVAR repairs with the Talent endograft (Medtronic, Inc., Minneapolis, MN) from March 1998 to June 2000 were analyzed. Stent graft-specific adverse events studied were migration, endoleak, kinking, thrombosis, and AAA expansion. Computed tomography (CT) scanning with three-dimensional post-processing and/or aortography was used to measure aortic neck angle. Patients were categorized into one of four groups according to their neck angle: I (0-10 degrees); II (11-39 degrees); III (40-59 degrees); or IV (60-85 degrees). Outcomes were evaluated by chi-squared analysis and ANOVA. There was a direct correlation between AAA diameter and neck angle (p = 0.002). There was no difference in endoleak rate (p = 0.877), stent migration (p = 0.850), or AAA expansion rate (p = 0.599) between groups. Device kinking >45 degrees was associated with neck angulation > or = 60 degrees (p = 0.013), but not with other adverse outcomes. The average neck angle was 30 degrees in patients with endoleaks and 31 degrees in patients without endoleaks. Increasing aortic neck angulation was not associated with the selected adverse outcomes within 1 year following EVAR with the Talent stent graft using suprarenal fixation with the exception of graft kinking. This may be related to the graft design that permits suprarenal aortic fixatiou of the proximal stent graft, Whether severe degrees of angulation of 60 degrees or greater can be safely treated with suprarenal fixation requires further study.

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.

Banding in aortic stent-graft fixation in EVAR

The authors describe the method of surgical aortic banding for better stent-graft fixation in cases of problematic aortic neck in the endovascular infrarenal aneurysms repair.

AAA elective treatment indication tactics in EVAR era

The authors describe their indication tactics for AAA elective treatment. Based on one-month morbidity and mortality they evaluate the results obtained in the past six years and compare the methods of open surgery, endovascular repair and combined strategy in AAAs elective repair.

Endovascular Abdominal Aortic Aneurysm Repair: Does Gender Matter?

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

A randomized trial comparing conventional and endovascular repair of abdominal aortic aneurysms

BACKGROUND

Although the initial results of endovascular repair of abdominal aortic aneurysms were promising, current evidence from controlled studies does not convincingly show a reduction in 30-day mortality relative to that achieved with open repair.

METHODS

We conducted a multicenter, randomized trial comparing open repair with endovascular repair in 345 patients who had received a diagnosis of abdominal aortic aneurysm of at least 5 cm in diameter and who were considered suitable candidates for both techniques. The outcome events analyzed were operative (30-day) mortality and two composite end points of operative mortality and severe complications and operative mortality and moderate or severe complications.

RESULTS

The operative mortality rate was 4.6 percent in the open-repair group (8 of 174 patients; 95 percent confidence interval, 2.0 to 8.9 percent) and 1.2 percent in the endovascular-repair group (2 of 171 patients; 95 percent confidence interval, 0.1 to 4.2 percent), resulting in a risk ratio of 3.9 (95 percent confidence interval, 0.9 to 32.9). The combined rate of operative mortality and severe complications was 9.8 percent in the open-repair group (17 of 174 patients; 95 percent confidence interval, 5.8 to 15.2 percent) and 4.7 percent in the endovascular-repair group (8 of 171 patients; 95 percent confidence interval, 2.0 to 9.0 percent), resulting in a risk ratio of 2.1 (95 percent confidence interval, 0.9 to 5.4).

CONCLUSIONS

On the basis of the overall results of this trial, endovascular repair is preferable to open repair in patients who have an abdominal aortic aneurysm that is at least 5 cm in diameter. Long-term follow-up is needed to determine whether this advantage is sustained.

Midterm outcome of endovascular abdominal aortic aneurysm repair in octogenarians: A single institution's experience

OBJECTIVES

We analyzed midterm durability of endovascular abdominal aortic aneurysm repair (EVAR) in octogenarians compared with younger patients.

METHODS

Data for 182 consecutive patients who underwent elective EVAR between 1999 and 2003 were retrospectively reviewed. Forty-nine patients (27%) were 80 years or older (study group [SG]; mean age, 84 years; range, 80-89 years), and 133 patients (73%) were younger (control group [CG]; mean age, 72 years; range, 53-79 years). Chi2 analysis, Fisher exact test, Student t test, and Mann-Whitney U test were used as appropriate to test for intergroup differences. Kaplan-Meier curves, log-rank tests, and multivariate Cox models were used for time-to-event analysis, with P < or =.05 considered significant.

RESULTS

Mean follow-up was 16 months (range, 1-43 months). Body weight was higher (P <.001), and elevated plasma lipid levels (59% vs 43%; P =.042) and use of nicotine (47% vs 29%; P =.015) more frequent in the octogenarians. Baseline aneurysm size, procedure-related data, and hospital stay were comparable between groups. Aneurysm-related mortality was 0% in the study group and 0.7% in the control group (P =.740). Systemic complications occurred in 22% (SG) versus 11% (CG) (P =.035), owing to a rise in serum creatinine concentration greater than 30% of baseline in 14% in the octogenarian group (vs 5% in the CG; P =.048). Groin lymphoceles developed in 12% (SG) versus 2% (CG; P =.013). Technical success was 96% (SG) versus 98% (CG; P =.408), and clinical success was 86% versus 90% (P =.269). No aneurysm rupture occurred during follow-up, and aneurysm-related adverse events were comparable between groups. The estimated risk for any type of endoleak (2.2; 95% confidence interval [CI], 1.1-4.2; P =.023) or type II endoleak (2.1; 95% CI, 1.0-4.3; P = 0.51) was higher in the study group versus the control group; however, this did not affect secondary procedure rates (SG 16% vs CG 12%; estimated risk, SG vs CG,: 1.5; 95% CI, 0.6-3.6; P = 0.420) or aneurysm remodeling (97.2% combined aneurysm sac stabilization or decrease in both groups; P =.592). Aneurysm enlargement occurred in 2.8% (SG 1 vs CG 4; P =.592).

CONCLUSION

Elective EVAR in octogenarians appears safe and effective over midterm follow-up, with a temporary decrease in renal function (14%) and postoperative lymphoceles (12%) being the most common postoperative adverse events. Advanced chronologic age is not associated with diminished procedural outcome, clinical success, or postoperative survival, compared with younger age. Because of low perioperative mortality and high procedural success, EVAR may be the preferred approach to abdominal aortic aneurysm treatment in selected elderly patients.

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.

Relationship of proximal fixation to postoperative renal dysfunction in patients with normal serum creatinine concentration

OBJECTIVES

This study was performed to determine whether there is deterioration in renal function during follow-up in patients who have undergone endovascular aneurysm repair (EVAR), as recommended by the device manufacturers; to determine whether suprarenal fixation correlates with impairment of renal function; and to explore the potential implication of life-long surveillance of renal function with contrast-enhanced computed tomography.

METHODS

One hundred forty-six consecutive patients underwent EVAR at our institution. Data from 113 of these patients who were free from preoperative renal insufficiency or postoperative renal disease were analyzed. Fifty-three patients received infrarenal (IR) fixation devices, and 60 patients received suprarenal (SR) fixation devices. All SR fixation devices were placed under investigational device exemption protocols. The average follow-up was 688 days. Sixty-five consecutive patients who had undergone open repair of an abdominal aortic aneurysm (AAA) served as the control group.

RESULTS

Preoperative creatinine concentration, intraoperative blood loss, contrast volume, and number of contrast-enhanced procedures were not significantly different between the IR and SR groups. Two renal artery occlusions (1 SR, 1 IR; P=NS) were identified, and 8 renal infarcts (5 SR, 3 IR; P=NS). There was an increase in mean creatinine concentration in the open AAA, IR, and SR fixation groups at each time point in the analysis. Mean elevation in creatinine concentration at 12, 24, and 36 months was 0.10, 0.10, and 0.04 mg/dL, respectively, for open AAA repair; 0.20, 0.21, and 0.28 mg/dL for IR fixation; and 0.15, 0.21, and 0.12 mg/dL for SR fixation. At life table analysis, renal impairment at 36 months was seen in 36% +/- 9% of patients in the IR group, 25% +/- % of patients in the SR group, and 19% +/- 6% of patients in the open AAA group (P=.04 for IR fixation vs open AAA repair).

CONCLUSIONS

A decrease in kidney function is seen after EVAR, regardless of fixation level, that is independent of renal disease and renal arterial occlusion. In patients with normal renal function the site of proximal fixation does not affect postoperative creatinine concentration. The decrease in renal function is likely related to the repetitive administration of contrast agent.

The Effect of Gender on Early and Intermediate Results of Endovascular Aneurysm Repair

Results of endovascular aneurysm repair (EVAR) may be gender dependent. Between September 1997 and September 2001, 118 AneuRx aortic grafts were placed for aneurysmal disease. During this period, 17 females and 101 males were treated with this device. A prospective database was maintained and supplemented with retrospectively gathered information to evaluate early and mid-term end points. A total of 113 devices were deployed in 118 attempts. Length of procedure was greater for females (3.3 +/- 1.75 vs. 2.3 +/- 0.8 hr, p = 0.05) and they were more likely to have significant arterial dissections (12% vs. 1%, p = 0.05). The mortality rates at 1 month were 12% for females and 0% for males ( p = 0.02); the complication rates at 1 month were 41% for females and 15% for males ( p = 0.02). Although technical success was not significantly different between the sexes, assisted primary technical success (requiring endovascular assistance) and assisted secondary technical success (requiring open surgical assistance) were significantly different (71% vs. 96%, p = 0.003; and 76% vs. 98%, p = 0.004, respectively). Clinical success at 1 month was 59% for females and 84% for males ( p = 0.02). This difference was also significant when assessing 1-month assisted primary clinical success (59% vs. 90%, p = 0.003) and assisted secondary clinical success as well (71% vs. 96%, p = 0.003). Clinical success and assisted primary clinical success were not different at 6- or 12-month intervals, however, assisted secondary clinical successes differed at both time intervals (56% vs. 83%, p = 0.02; and 56% vs. 81%, p = 0.05, respectively). As-yet undetermined factors appear to predispose females to complications and technical difficulties in the short term. Endovascular and open procedures required to achieve ongoing clinical success in the following months appear to favor males to a greater degree than females.

Does hostile neck anatomy preclude successful endovascular aortic aneurysm repair?

OBJECTIVES

Poor outcomes have been reported with endovascular aneurysm repair (EVAR) in patients with hostile neck anatomy. Unsupported endografts with active fixation may offer certain advantages in this situation. We compared EVAR results using the Ancure (Guidant) endograft in patients with and without hostile neck anatomy.

METHODS

Records of EVAR patients from October 1999 to July 2002 at a tertiary care hospital were retrospectively reviewed from a division database. Patients with elective open abdominal aortic aneurysm (AAA) repair during the same period were reviewed to determine those unsuitable for EVAR. Hostile neck anatomy, assessed by computer tomography (CT) scans and angiograms, was defined as one or more of the following: (1) neck length </=10 mm, (2) focal bulge in the neck >3 mm, (3) >2-mm reverse taper within 1 cm below the renal arteries, (4) neck thrombus > or =50% of circumference, and (5) angulation > or =60 degrees within 3 cm below renals.

RESULTS

Three hundred and twenty-two patients underwent EVAR with an average follow-up of 18 months. Patients in Phase II trials (n = 41), repaired with other graft types (n = 48), or without complete anatomic records (n = 27) were excluded. Demographics and co-morbidities were similar in the 115 good-neck (GN) and 91 bad-neck (BN) patients except for age (mean, 72.9 years GN vs 75.7 BN; P = 0.13), gender (11% female GN vs 22% BN; P =.04); neck length (mean, 21.8 mm GN vs 14.4 mm BN: P <.001), and angulation (mean, 22 degrees GN vs 40 degrees BN; (P <.001). Perioperative mortality (0 GN vs 1.1% BN), late mortality (5.2% GN vs 4.4% BN), all endoleaks (19.1% GN vs 17.6% BN), proximal endoleaks (0.8% GN vs 2.1% BN), and graft migration (0 for both groups) did not reach statistical significance. Neck anatomy precluded EVAR in 106 of 165 (64%) patients with open AAA.

CONCLUSIONS

Unsupported endografts with active fixation can yield excellent results in treating many medically compromised patients with hostile neck anatomy. Nonetheless, an unsuitable neck remains the most frequent cause for open abdominal AAA.

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.

Aortoiliac morphologic correlations in aneurysms undergoing endovascular repair

PURPOSE

The feasibility of endovascular aneurysm repair depends on morphologic characteristics of the aortoiliac segment. Knowledge of such characteristics is relevant to safe deployment of a particular device in a single patient and to development of new devices for use in patients with a broader spectrum of anatomic variations.

METHODS

We evaluated findings on computed tomography scans for 277 patients being considered for endovascular aneurysm repair. Aortic neck length and angulation estimates were generated with three-dimensional trigonometry. Specific centerline points were recorded, corresponding to the aorta at the celiac axis, lowest renal artery, cranial aspect of the aneurysm sac, aortic terminus, right hypogastric artery origin, and left hypogastric origin. Aortic neck thrombus and calcium content were recorded, and neck conicity was calculated in degrees. Statistical analysis was performed with the Spearman rank correlation. Data are expressed as median and interquartile range.

RESULTS

Median diameter of the aneurysms was 52 mm (interquartile range, 48-59 mm) in minor axis and 56 mm (interquartile range, 51-64 mm) in major axis, and median length was 88 mm (interquartile range, 74-103 mm). Median proximal aortic neck diameter was 26 mm (interquartile range, 22-29 mm), and median neck length was 30 mm (interquartile range, 18-45 mm). The common iliac arteries were similar in diameter (right artery, 16 mm [interquartile range, 13-20 mm]; left artery, 15 mm [interquartile range, 11-18 mm]) and length (right, 59 mm [interquartile range, 50-69 mm]; left, 60 mm [interquartile range, 49-70 mm]). Median angulation of the infrarenal aortic neck was 40 degrees (interquartile range, 29-51 degrees), and median angulation of the suprarenal segment was 45 degrees (interquartile range, 36-57 degrees). By gender, sac diameter, proximal neck diameter, and iliac artery diameter were significantly larger in men. Significant linear associations were identified between sac diameter and sac length, neck angulation, and iliac artery diameter. As the length of the aneurysm sac increased the proximal aortic neck length decreased. Conversely, as the sac length decreased sac eccentricity increased. Mural thrombus content within the neck increased with increasing neck diameter.

CONCLUSIONS

There is considerable variability in aortoiliac morphologic parameters. Significant associations were found between various morphologic variables, links that are presumably related to a shared pathogenesis for aberration in aortoiliac diameter, length, and angulation. Ultimately this information can be used to develop new endovascular devices with broader applicability and improved long-term results.

Endovascular aneurysm repair: gender-specific results

OBJECTIVES

The outcome for a wide variety of diseases and treatment methods varies by gender. In an effort to determine whether gender has a role in the outcome of endovascular aortic aneurysm repair, we analyzed data from consecutive patients treated at a single institution over 6 years.

METHODS

Over 6 years ending in March 2002, 704 patients underwent endovascular repair of an infrarenal abdominal aortic aneurysm at The Cleveland Clinic. Six hundred six patients (86.1%) were men and 98 patients (13.9%) were women. Preprocedure and postprocedure imaging studies were evaluated to determine the frequency of aneurysm sac shrinkage or growth, defined as diameter change equal to or greater than 5 mm. Presence and type of endoleak was assessed with non-contrast material-enhanced, post-contrast-enhanced, and delayed post-contrast-enhanced computed tomography scans. These and other clinical variables were assessed with the Kaplan-Meier method and the Cox-Mantel log-rank test, and values were expressed as mean +/- SE.

RESULTS

Male and female patients were comparable with respect to baseline comorbid conditions. Women, however, were slightly older (76.7 +/- 0.7 years vs 74.4 +/- 0.3 years; P =.009), and had slightly smaller aneurysms (5.2 +/- 0.1 cm vs 5.4 +/- 0.04 cm; P =.033). There were no gender-specific differences in perioperative mortality (men, 1.3%; women, 3.1%; P =.197) or mid-term (24 months) survival (men, 80% +/- 2.6%; women, 78% +/- 8.1%). Similarly, there were no differences at 24 months in risk for graft migration (7.5% +/- 2.0% vs 5.4% +/- 3.2%), need for secondary remedial procedures (24% +/- 2.9% vs 21% +/- 6.3%), conversion to open surgery (3.9% +/- 1.5% vs 3.8% +/-2.7%), or post-repair aneurysm rupture (1.1% +/- 0.9% vs 2.2% +/-2.2%) in male and female patients, respectively. In contrast, risk for graft limb occlusion at 24 months was significantly higher in women than in men (11% +/- 5.2% vs 3.3% +/- 1.1%; P =.022). While frequency of endoleak of any type did not differ among male and female patients, aneurysm sac shrinkage at 24 months was more rapid in women (76% +/- 8.1% vs 57% +/- 3.5%; P =.019).

CONCLUSIONS

With the exception of slightly older age and somewhat smaller aneurysm, female patients are similar to male patients undergoing endovascular aneurysm repair. A greater frequency of graft limb occlusion was observed in female patients, but no statistically significant differences were detected in survival, rupture risk, or need for secondary procedures. Moreover, a more rapid rate of aneurysm sac shrinkage was detected in women. These observations suggest that endovascular aneurysm repair should be offered to suitable candidates irrespective of gender.

Does gender influence outcome of AAA endoluminal repair?

BACKGROUND

It has been suggested that female patients have a less favourable outcome of endoluminal repair of abdominal aortic aneurysms. Yet, data on stratified per gender are lacking.

METHODS

We reviewed our prospective database of 402 endografts over a 4-year period and the peri- and postoperative course in the 25 (6%) female patients was compared with the 377 (94%) male patients. Median follow-up was 24 months (range 1-56 months). Logistic regression analysis was performed to test the effect of five confounding variables (gender, age, ASA grade IV, EUROSTAR class D or E, AAA diameter) on failure of AAA exclusion.

RESULTS

There were no perioperative deaths in the female group and 5 (1.3%) in the male group (p = 0.8). Major perioperative morbidity occurred in 17% versus 6% (OR 3.7; 95% CI 1.2-10.6; p = 0.026). There were 1 (4%) and 5 (1%) conversions to open repair in the female and male groups, respectively (p = 0.3). Late failure of AAA exclusion occurred in 5 (21%) and 26 (7%) patients, respectively (p = 0.03). Of the five variables examined for their influence on failure of AAA exclusion, female gender (hazard ratio 4.42; 95% CI 1.4-13.4; p = 0.009) and AAA diameter (hazard ratio 1.05; 95% CI 1.009-1.09; p = 0.017), were positive independent predictors of late failure of AAA exclusion on multivariate analysis.

CONCLUSION

Endoluminal AAA repair in female patients appear associated with a less favorable outcome when compared to their male counterparts. These data may be taken into consideration when endoluminal AAA repair is suggested to a female patient.

Effect of suprarenal versus infrarenal aortic endograft fixation on renal function and renal artery patency: a comparative study with intermediate follow-up

PURPOSE

Suprarenal fixation of aortic endografts appears to be a safe option in patients with a short or conical proximal aortic neck. However, concern persists regarding the long-term effect on renal function when renal artery ostia are crossed by the uncovered stent. We investigated the effect of suprarenal versus infrarenal endograft fixation on renal function and renal artery patency after endovascular aortic aneurysm repair.

METHODS

Records of 91 patients who underwent endovascular aortic aneurysm repair with a modular bifurcated stent graft between November 1999 and January 2002 were reviewed retrospectively. Two patients receiving dialysis because of chronic renal failure were excluded. Infrarenal fixation was used in 57 patients (group 1), and suprarenal fixation was used in 32 patients (group 2). In two patients in group 1 a Gianturco Z stent was inserted transrenally because of intraoperative proximal type I endoleak, and data for these patients were excluded from analysis. Follow-up evaluation was performed at 1, 6, and 12 months, and yearly thereafter, and included clinical assessment, measurement of serum creatinine concentration (SCr), and computed tomography angiography, per standard protocol. Median follow-up was 12 months (range, 1-36 months).

RESULTS

There was no statistically significant difference in patient demographic data, aneurysm size, or preoperative risk factors. Median SCr was significantly higher in group 2 (suprarenal fixation) than in group 1 (infrarenal fixation) preoperatively (1.2 mg/dL [range, 0.6-2.3 mg/dL] vs 0.9 mg/dL [range, 0.6-1.9 mg/dL], P =.008) and at 1 month postoperatively (1.1 mg/dL [range, 0.8-5.6 mg/dL] vs 1.0 mg/dL [range, 0.6-2.1 mg/dL], P =.045). There was a significant increase in median SCr in both groups at 1 month postoperatively (group 1, 1.0 mg/dL [range, 0.6-2.1 mg/dL], P =.05; group 2, 1.1 mg/dL [range, 0.8-5.6 mg/dL] [mean SCr, 1.35 mg/dL vs 1.15 mg/dL, respectively], P <.05). In group 1 SCr was increased significantly at 6 and 12 months (P <.001), whereas in group 2 SCr also increased at 6 and 12 months, but not significantly. The change in SCr over time was not significantly different between the two groups. In two of 32 patients in group 2, renal artery occlusion developed, associated with perfusion defects in renal parenchyma and persistently elevated SCr. Analysis of renal artery patency did not demonstrate any association between patency and treatment. No patient developed hypertension during follow-up.

CONCLUSIONS

Suprarenal endograft fixation does not lead to significant renal dysfunction, and renal artery occlusion is uncommon within 12 months. A larger study with longer follow-up is essential to determine overall effects on renal function and renal artery patency.

Endoluminal AAA repair using intravascular ultrasound for graft planning and deployment: a 2-year community-based experience

PURPOSE

To examine the effectiveness of intravascular ultrasound (IVUS) and digital subtraction angiography (DSA) for preoperative planning and intraoperative deployment of stent-grafts to treat abdominal aortic aneurysms.

METHODS

One hundred seventy patients (143 men; mean age 73.6+/-7.2 years, range 51-89) underwent successful DSA and IVUS to determine suitability for stent-graft repair. Patients subsequently received the AneuRx (n=157) or Ancure (n=13) device; intraprocedural IVUS was used to survey the proximal endograft for proper apposition to the aortic wall.

RESULTS

Reliable preoperative IVUS measurements were obtained in all patients. Plaque morphology was assessed in 140 (82.3%) aortic necks; in 36 (25.7%), preoperative IVUS showed high-grade atherosclerotic plaque in the nonaneurysmal abdominal aortic neck. The procedure was successful in 168 (98.8%) cases (1 [0.6%] acute conversion and 1 access failure). There were 2 (1.2%) periprocedural deaths related to bowel ischemia. Four (2.3%) patients developed graft occlusion/kinking and 2 (1.2%) developed renal failure requiring dialysis within 30 days. Multivariate logistic regression analysis revealed that female gender (p=0.0247), a short nonaneurysmal aortic neck (p=0.0185), and presence of high-grade atherosclerotic plaque (p=0.0185) correlated with major acute complications. Over a mean 10.4-month follow-up (range 1-25), 11 patients died of unrelated causes; there was no known AAA rupture or device failure. The Kaplan-Meier estimate of survival at 1 year was 91.0%+/-2.8%. Sixteen (9.4%) patients underwent 17 secondary procedures for endoleak or graft limb occlusion at a mean 5.4 months after stent-graft repair (freedom from secondary intervention at 1 year 86.5%+/-3.2%).

CONCLUSIONS

Our findings suggest that IVUS may identify patients at increased risk of major adverse complications following endovascular repair. The combination of IVUS and DSA for endoluminal stent-graft planning and placement provides excellent short- and mid-term patient outcomes.

Retrograde endovascular hypogastric artery preservation (REHAP) and aortouniiliac (AUI) endografting in the management of complex aortoiliac aneurysms

The preservation of internal iliac artery (IIA) flow during endovascular repair of abdominal aortic aneurysms (er-AAA) remains a controversial area. Ectasia and aneurysmal disease of the iliac arteries represent a formidable challenge to the endovascular surgeon, particularly when aortic neck length and diameter are suitable for er-AAA. We describe a procedure to maintain arterial perfusion to the pelvis during er-AAA called retrograde endovascular hypogastric artery preservation (REHAP). This technique is particularly useful in the presence of common iliac artery (CIA) and internal iliac artery (IIA) aneurysms when pelvic perfusion to one IIA needs to be maintained. A Wallgraft is first placed from the IIA to the ipsilateral EIA followed by er-AAA using an aortouniiliac graft (AUI) and a femorofemoral bypass graft (BPG). This procedure represents one alternative to maintaining pelvic perfusion using standard endovascular and surgical techniques.

Evaluation of aortoiliac aneurysm before endovascular repair: comparison of contrast-enhanced magnetic resonance angiography with multidetector row computed tomographic angiography with an automated analysis software tool

PURPOSE

The purpose of this study was to assess accuracy and reliability of a volumetric analysis of abdominal aneurysms on the basis of multidetector row computed tomographic angiography (CTA) and magnetic resonance angiography (MRA) with a commercially available automated vessel analysis software program.

MATERIALS AND METHODS

Twenty patients with abdominal aortic aneurysms underwent preoperative CTA and MRA before endovascular repair. Postdeployment CTA was performed in 15 of these 20 patients (75%). All preoperative CTA and MRA and postdeployment CTA data sets were analyzed with an automated software tool. The length of the stent grafts on postdeployment CTA was measured and compared with the true length of the primary component. Two readers independently evaluated 13 vessel parameters on preoperative CTA and MRA, which are considered to be important in planning stent graft deployment.

RESULTS

With the automated analysis software tool, all measurements could be performed on either CTA or MRA data sets. There was no statistically significant difference between postdeployment measurements of stent graft length on CTA and the true dimensions of the implanted stent grafts. Interobserver agreement for all of the measurements with either CTA or MRA was good to excellent (interclass coefficient, 0.71 to 0.99) with only minimal mean differences of measured dimensions between both readers (range, -2.0 to +2.3 mm, Bland-Altman). Intermodality agreement between CTA and MRA was good to excellent (interclass coefficient, 0.62 to 0.98) with small mean differences of measured dimensions between both methods (range, -4.1 to +2.1 mm, Bland-Altman).

CONCLUSION

Volumetric measurement with an automated analysis software tool allows a fast, precise, and reliable noninvasive preoperative determination of all aortic dimensions on the basis of either CTA or MRA data sets.

Endovascular repair for abdominal aortic aneurysms: initial experience of an endograft programme

OBJECTIVE

To evaluate early clinical results of elective endovascular repair of abdominal aortic aneurysms during the initial phase of an aortic endograft programme and to compare them with conventional open surgery.

METHODS

Between July 1999 and September 2001, all patients with infrarenal abdominal aortic aneurysms undergoing elective repair were studied. The results of endovascular repair were compared with those of conventional repair.

RESULTS

Twenty-seven endovascular repairs (24 men and three women; mean age, 74 yr) and 25 conventional repairs (19 men and six women; mean age, 73 yr) for infrarenal abdominal aortic aneurysms were evaluated. The aneurysm diameters in the two groups were similar (mean, 6.1 cm in the endovascular repair group and 6.6 cm in the conventional repair group). The comorbidities of the two groups were also comparable. The duration of operation was longer in the endograft group (249 +/- 86 min vs. 206 +/- 56 min), while the blood loss was significantly less (600 +/- 486 mL vs. 1074 +/- 1220 mL). The length of stay in the Intensive Care Unit (ICU) and the overall duration of hospitalization was also significantly less in the endograft group (1 +/- 1 d vs. 3 +/- 2 d in ICU; 9 +/- 5 d vs. 13 +/- 6 d of hospitalization). There was one hospital death in each group (4%), and the complications were similar between the two groups. During a mean follow-up period of 11.6 +/- 7.5 months, there was no rupture or open conversion in the endograft group.

CONCLUSIONS

In the initial phase of the aortic endograft programme, the mortality and morbidity were acceptable and comparable to that of open surgery.

Delivery of endovascular grafts by direct sheath placement into the aorta or iliac arteries

Delivery of endovascular grafts via femoral access in patients with iliac arterial tortuosity or occlusive disease can be problematic. Aortomonoiliac grafts or arterial conduits sewn to proximal iliac arteries through an abdominal incision have been used as alternatives. A technique is described in which the proximal access vessel, aorta or iliac artery, is punctured directly and a large sheath inserted, through which the endovascular graft may be delivered. Hemostasis is achieved by use of a superficially placed concentric double purse-string suture. The technique has been employed successfully for placement of both thoracic and abdominal endografts.

Eligibility rates of ruptured and symptomatic AAA for endovascular repair

PURPOSE

To determine the anatomical eligibility rate for endovascular repair of ruptured and symptomatic abdominal aortic aneurysms (AAA) using commercially available endografts.

METHODS

In a retrospective review, 28 preoperative computed tomographic (CT) scans were examined from among 83 patients who underwent surgical repair of a ruptured or acutely symptomatic AAA at a university-based tertiary care center during the past 10 years. The proximal aortic neck, aneurysm, and iliac dimensions were compared to corresponding measurements from 100 preoperative CT scans from patients who underwent elective repair of asymptomatic AAA. Based on expanded selection criteria for the 2 FDA-approved endografts (AneuRx and Ancure), eligibility rates for endovascular repair were compared between patients with ruptured/symptomatic and asymptomatic AAAs.

RESULTS

The proximal neck of the ruptured/symptomatic AAAs was on the average 2 mm larger in diameter (25 +/- 4 versus 23 +/- 3 mm, p=0.04) and 7 mm shorter (16 +/- 10 versus 23 +/- 14, p=0.017) than asymptomatic AAAs. The maximum AAA diameter was significantly larger in the ruptured/symptomatic group (64 +/- 16 mm) than in the asymptomatic group (58 +/- 11 mm, p=0.033). Of the 28 ruptured/symptomatic AAAs assessed morphologically, 13 (46%) were anatomically eligible for endovascular repair compared to 74 of the 100 asymptomatic AAAs (p=0.006). The main cause for exclusion was an unfavorable proximal neck, which was present in 15 (54%) of the 28 ruptured/symptomatic AAAs and in 24 (24%) of the 100 asymptomatic AAAs (p=0.003).

CONCLUSIONS

A significantly smaller proportion of patients presenting with ruptured/symptomatic AAA are anatomically eligible for endovascular AAA repair compared to patients with asymptomatic AAA due to unfavorable proximal neck anatomy.

Gender differences in endovascular abdominal aortic aneurysm repair with the AneuRx stent graft

OBJECTIVE

The objective of this study was to evaluate gender differences in the selection, procedure, and outcome of endovascular abdominal aortic aneurysm repair (EVAR).

PATIENTS

Between October 1996 and January 2001, 378 patients were evaluated for EVAR and 189 patients underwent EVAR with the Medtronic AneuRx stent graft at a single center.

RESULTS

Women constituted 17% of patients considered for EVAR. Their eligibility rate (49%) did not differ significantly from that of men (57%), and they constituted 14% of patients who underwent EVAR (26/189). Women who underwent EVAR were older (77.9 +/- 6.3 years versus 73.1 +/- 8.1 years; P <.005) with a higher rate of chronic obstructive lung disease (50% versus 28%; P <.05). Maximal aneurysm diameter (57.2 +/- 10.9 mm versus 57.8 +/- 9.4 mm; not significant) did not differ between men and women. Mean diameters of the proximal neck (20.4 +/- 2.3 mm versus 22.3 +/- 2.0 mm; P <.01), common iliac arteries (11.4 +/- 1.2 mm versus 13.5 +/- 3.6 mm; P <.001), and external iliac arteries (7.9 +/- 0.7 mm versus 9.4 +/- 1.4 mm; P <.001) were all smaller in women, and abdominal aortic aneurysm/neck diameter ratio was larger (2.82 +/- 0.59 versus 2.60 +/- 0.49; P <.05). The length of the proximal aortic neck was shorter in women (20.7 +/- 8.2 mm versus 24.5 +/- 11.8 mm; P <.05). Women had significantly more intraoperative complications (31% versus 13%; P <.05), primarily related to arterial access, and needed more frequent arterial reconstruction (42% versus 21%; P <.05), without a difference in postoperative mortality rate (0/26 versus 2/163; not significant) and complication rate (23% versus 20%: not significant). During a follow-up period of 13.8 +/- 11.7 months, no gender-related difference was found in survival rate, endoleak rate, or reintervention rate or in the rate of change in aneurysm diameter or volume.

CONCLUSION

Eligibility rates of women for EVAR are similar to those of men. Women are at an increased risk for access-related complications during EVAR, but outcome is equivalent to that of men.