Endovascular Repair Of Infrarenal Abdominal Aortic Aneurysms Research Articles

Value of contrast-enhanced ultrasonography in detection of endoleak after endovascular repair of infrarenal abdominal aortic aneurysm

Objective: To investigate the value of contrast-enhanced ultrasound in detecting endoleak after endovascular repair of infrarenal abdominal aortic aneurysm (EVAR). Methods: The postoperative follow-up data of 102 patients with infrarenal abdominal aortic aneurysm treated with EVAR in Tianjin Medical University General Hospital from August 2015 to December 2021 were retrospectively analyzed. There were 79 males and 23 females, aged 50-91 (69.6±7.6) years old. Using CT angiography (CTA) as the gold standard for diagnosing endoleaks, the effectiveness of contrast-enhanced ultrasound and CDUS in detecting endoleaks was evaluated by paired design chi-square test, and the Kappa value was calculated for consistency test. Patients were divided into groups according to body mass index (BMI), and the number of false-negative endoleaks detected by contrast-enhanced ultrasound in each group was calculated, and its ratio to the actual number of endoleaks was calculated to evaluate whether BMI was related to false-negative ultrasound-enhanced ultrasound. Results: A total of 203 follow-up visits met the inclusion criteria. Endoleaks were detected 36 times (17.7%) by CTA, 31 times (15.3%) by contrast-enhanced ultrasound, 16 times (7.9%) by CDUS, and they all detected type Ⅰ, type Ⅱ and type Ⅲ endoleaks. There was no significant difference between contrast-enhanced ultrasound and CTA in endoleak detection rate and determination of endoleak types (endoleak detection rate: 15.3% vs 17.7%; determination of endoleak types: type Ⅰ 4 vs 4, type Ⅱ 26 vs 31, type Ⅲ 1 vs 1; all P>0.05). CDUS and CTA had statistically significant differences in the detection rate of endoleaks and determination of endoleak types (endoleak detection rate: 7.9% vs 17.7%; determination of endoleak types: type Ⅰ 4 vs 4, type Ⅱ 11 vs 31, type Ⅲ 1 vs 1; all P<0.001). Compared with CTA, contrast-enhanced ultrasound has a sensitivity of 83.3%, a specificity of 99.4%, a Youden index of 0.827, a coincidence rate of 96.6%, a positive predictive value of 96.8%, a negative predictive value of 96.5%, and a Kappa value of 0.875(P<0.001). The two showed excellent diagnostic consistency. All 6 endoleaks not detected by contrast-enhanced ultrasound were type Ⅱ endoleak that did not require treatment, and 3(15.8%) occurred in obese patients with a BMI≥32 kg/m2. Compared with CTA, CDUS had a sensitivity of 38.9%, a specificity of 98.8%, a Youden index of 0.377, a coincidence rate of 88.2%, a positive predictive value of 87.5%, a negative predictive value of 88.2%, and a Kappa value of 0.482 (P<0.001). The two showed moderate diagnostic agreement. The correlation coefficient of the maximum diameter of aneurysms measured by ultrasound and CT was r=0.873(P<0.001). Conclusions: Contrast-enhanced ultrasound is accurate in detecting endoleak after infrarenal EVAR, and its sensitivity to endoleak detection in obese patients with BMI≥32 kg/m2 will be reduced. CDUS is not suitable for detection of endoleak after infrarenal EVAR, but it can be used to monitor the change of the largest diameter of aneurysm after EVAR.

Overview of the 2018 US Food and Drug Administration Circulatory System Devices Panel meeting on the INCRAFT AAA Stent Graft System.

On June 12, 2018, the US Food and Drug Administration (FDA) convened a meeting of the Circulatory System Devices Panel to advise on the safety and effectiveness of the INCRAFT® AAA Stent Graft System for the treatment of abdominal aortic aneurysms (AAA) and to consider a premarket approval application sponsored by Cordis, Inc., for Unique identifier: NCT01664078 based on the results of the pivotal INSPIRATION trial (URL: https://clinicaltrials.gov/ct2/show/NCT01664078). The INCRAFT® AAA Stent Graft System is designed for endovascular repair of infrarenal AAAs with complex aortic anatomies. The stent-graft system utilizes nitinol stent and polyester graft technology in an ultra-low profile delivery system, with the goal of isolating the aneurysmal sac and preventing sac rupture. The multicenter, prospective, non-randomized investigation trial met its primary composite safety and effectiveness endpoints but also showed higher-than-anticipated rates of stent fracture and endoleaks. The committee discussion focused on how these events impact the long-term safety and effectiveness, as well as the benefit/risk profile, of the device. While the panel acknowledged the risk of the device, the panel's final vote supported that the benefits of the INCRAFT AAA Stent Graft System outweigh the risks and that a post-marketing study should be mandated. The FDA approved the device for use in complex access anatomies in December 2018.

Mortality after endovascular treatment of infrarenal abdominal aortic aneurysms - the newer the better?

Although endovascular repair of infrarenal abdominal aortic aneurysms (EVAR) presents a delicate alternative treatment for abdominal aortic aneurysms (AAA) with lower perioperative mortality, its long-term efficacy remains a matter of concern. The purpose of this study was to evaluate the currently reported mortality evidence after EVAR and to examine the possible effect of aneurysm status and the study period on mortality rates. The PubMed and Cochrane bibliographical databases were thoroughly searched for studies reporting on more than 1 000 patients with non-ruptured or ruptured infrarenal AAA, treated with EVAR from August 1991 to September 2016. A total of 10 910 titles/abstracts were retrieved and 121 studies were deemed relevant. Twenty-six studies met the inclusion criteria and reported on 354 500 patients with a mean age of 74.6 years. Almost all of the studies referred to elective EVAR and the mean aneurysm size was 5.58 cm. The most common early complication for elective EVAR was perioperative bleeding (1.9 %), whereas hospital-acquired pneumonia was a major concern in urgent EVAR (28.5 %). Conversion rate to open surgery was 1.2 %. The 30-day all-cause mortality rate was 4.84 % (1.7 % for non- ruptured aneurysms, 33.8 % for ruptured aneurysms).The overall all-cause late mortality in a mean follow-up period of 23.8 months was 19.1 %. The aneurysm-related late mortality rate was 3.4 %. With respect to the time period of patient enrollment, studies reporting on patients recruited before 2006 were found to face more secondary complications and higher late mortality rates than patients enrolled after 2005.The endovascular treatment of large and anatomically suitable infrarenal AAA in selected patients remains a safe alternative to open repair. Our findings demonstrate that newer studies show better long-term outcomes than the older ones, proposing a possible improvement of EVAR techniques and perioperative care and providing encouraging evidence for a wider application of EVAR.

Endovascular conversion into aorto-uniiliac configuration of acute failed endovascular aneurysm repair is associated with better one-year survival rates compared to open conversion

BackgroundOpen conversions (OC) due to failed endovascular repair of infrarenal abdominal aortic aneurysms (EVAR) are technically demanding because of preexisting prostheses and advanced aortic disease. This study evaluates the feasibility and outcomes of aorto-uniiliac endografting (AUI) as an alternative treatment option in acute failed EVAR. MethodsFrom March 1995 through February 2012, 26 patients underwent acute conversion of failed EVAR at our tertiary care university center. All data were prospectively entered in our institutional database. Outcomes included 30-day or in-hospital mortality, postoperative complications, and mid-term survival. ResultsDuring the investigation period, a total of 692 patients received EVAR at our institution, while five of the 26 patients with acute conversion (19.2%) had an initial EVAR at an outlying institution and were referred for treatment. Therefore, our estimated institutional rate of acute conversions was 3% (21 of 692 EVAR). OC were performed in 14 patients (53.8%), while 12 patients underwent AUI (46.2%). An average time of 20.3 months (median: 18.6; interquartile range Q1–Q3: 0.0–38.6) elapsed between the initial EVAR and the acute conversion. All acute AUI conversion procedures were completed successfully. The 30-day mortality following acute conversions was 42.3% and since the use of AUI, it could be reduced to 33.3%. Kaplan–Meier estimates revealed a survival advantage for AUI at one year (p = 0.046), but the benefit was lost by mid-term follow-up (p = 0.103). ConclusionsAUI for the treatment of acute failed EVAR represents a feasible and less invasive alternative to OC, and is associated with better one-year survival rates.

Management of a Type Ia Endoleak With the Nellix Endovascular Aneurysm Sealing System

Purpose: To report the application of the Nellix endovascular aneurysm sealing (EVAS) device, including two chimney grafts, to successfully treat a type Ia endoleak. Case Report: An 87-year-old man had an asymptomatic 7.6-cm infrarenal abdominal aortic aneurysm (AAA) and a 4.5-cm right internal iliac artery aneurysm treated using an aortouni-iliac stent-graft. Two years after the index endovascular repair, an asymptomatic type Ia endoleak was detected on duplex ultrasound; the computed tomographic angiogram (CTA) demonstrated significant sac enlargement and stent-graft migration. Initial attempts to treat the leak with 2 aortic cuffs only reduced the size of the endoleak. Another procedure was undertaken using the Nellix device with chimney grafts to increase the proximal sealing zone above the existing stent-graft. Imaging postoperatively demonstrated successful resolution of the endoleak and continuing patency of both renal artery chimney stent-grafts. CTA at 6 months demonstrated persistent sealing of the endoleak. Conclusion: The use of the EVAS system may represent another endovascular solution that can be added to the clinician’s repertoire for treating type Ia endoleak after conventional endovascular repair of infrarenal AAA.

Results of endovascular aortic aneurysm repair with general, regional, and local/monitored anesthesia care in the American College of Surgeons National Surgical Quality Improvement Program database

This study examined outcomes of endovascular repair of infrarenal abdominal aortic aneurysms (EVAR) using general, spinal, epidural, and local/monitored anesthesia care (MAC) in a multicenter North American hospital database reflecting contemporary anesthesia and surgical practices. Elective EVAR cases performed between 2005 and 2008 were identified from the American College of Surgeons National Surgical Quality Improvement Program database using Current Procedural Terminology codes. Excluded were emergency cases and patients with concomitant procedures requiring general anesthesia. Patient-level comorbidities, characteristics, and intraoperative and postoperative details were examined. Complications were analyzed individually and in aggregate categories, including wound, pulmonary, renal, venous thromboembolic, cardiovascular, operative, and septic. Length of stay (LOS) and 30-day mortality were examined. Characteristics and outcomes were described using mean ± standard deviation or count (%), and comparisons were evaluated for statistical significance using χ(2), Fisher exact test, and univariate linear regression. LOS was analyzed with linear regression techniques using a log transformation. Associations between anesthesia type and outcomes were examined using univariable and multivariable regression techniques. We identified 6009 elective EVAR procedures for analysis. General anesthesia was used in 4868 cases, spinal anesthesia in 419, epidural anesthesia in 331, and local/MAC in 391. Defined morbidity occurred in 11% of patients. Median LOS was 2 (interquartile range, 1-3) days, and mean LOS was 2.8 ± 4.3 days. The 30-day mortality rate was 1.1%. Significant multivariate associations were observed between anesthesia type, pulmonary morbidity, and log-LOS. General anesthesia was associated with an increase in pulmonary morbidity vs spinal (odds ratio [OR], 4.0; 95% confidence interval [CI], 1.3-12.5; P = .020) and local/MAC anesthesia (OR, 2.6; 95% CI, 1.0-6.4; P = .041). Use of general anesthesia was associated with a 10% increase in LOS for general vs spinal anesthesia (95% CI, 4.8%-15.5%; P = .001) and a 20% increase for general vs local/MAC anesthesia (95% CI, 14.1%-26.2%; P < .001). Trends toward increased pulmonary morbidity and LOS were not observed for general vs epidural anesthesia. No significant association between anesthesia type and mortality was observed. In contemporary North American anesthetic and surgical practice, general anesthesia for EVAR was associated with increased postoperative LOS and pulmonary morbidity compared with spinal and local/MAC anesthesia. These data suggest that increasing the use of less-invasive anesthetic techniques may limit postoperative complications and decrease the overall costs of EVAR.

Strategies of endoleak management following endoluminal treatment of abdominal aortic aneurysms in 95 patients: how, when and why

This study reviews, on the basis of our experience, the indications and options for treating endoleaks (EL) after endovascular repair of abdominal aortic aneurysms (AAA) by endografting. Ninety-five patients (M/F =92/3; mean age at time of operation 70.7+/-7.8 years) who underwent endovascular repair of infrarenal AAA between April 1997 and October 2004 were considered. All images of 420 pre-and postoperative computed tomography (CT) studies were reviewed. A total of 37 EL occurred in 33/95 patients (34.7%), four of whom had two EL of different types. Eighteen EL were treated, 16 by endoluminal treatment. Six EL were type I: 2 were treated by percutaneous transluminal angioplasty (PTA) and 4 by cuff deployment (2 proximal cuffs and 2 distal cuffs). Eight EL were type II: 2 were treated by PTA, 2 by cuff deployment, 1 by transcatheter coil embolisation of the inferior mesenteric artery, two by thrombin injection in the aneurysm sac and one underwent surgical conversion during an attempt to treat a concomitant type I EL. Finally, 2 EL were type III: 1 was treated by PTA and 1 by cuff deployment. Endovascular treatment was successful in 12/16 cases (75%), whereas 3/16 cases (18.8%) were converted to open surgery, and 1 patient died of AAA rupture the day after endovascular repair. EL is the most common complication after endovascular repair of AAA. In type I and type III EL, treatment is mandatory, whereas in type II (and type V) EL, treatment is indicated in the presence of AAA enlargement. Type IV EL generally disappear spontaneously. Endovascular repair is feasible and can be performed with different techniques according to EL aetiology, but it is not always decisive, and in some cases surgical conversion is required.

A Single-Institution Experience with the AneuRx Stent Graft for Endovascular Repair of Abdominal Aortic Aneurysm

We report our experience of endovascular repair of infrarenal abdominal aortic aneurysms (EVAR) using the modular AneuRx Stent Graft System. We retrospectively reviewed the outcomes of 113 patients who underwent EVAR with the AneuRx system performed at our institution between October 1999 and August 2003. The mean age of this group was 72.5 years, with 71% (n = 80) over the age of 70 years and 95% (n = 107) males. Aneurysm diameter ranged 4.0-9.0 cm, with 33% (n = 37) >6.0 cm. The average duration of late follow-up was 32.6 +/- 24.8 months (median = 37). Successful deployment of the modular AneuRx system was noted in all patients. There were no immediate operative conversions, deaths within 24 hr of operation, or type I or III endoleaks observed at the completion of the procedure. Thirty-day mortality was 3.5% (n = 4). Acute deployment-related complications occurred in 10% (n = 13) of patients and included misdeployment, operative bleeding, arterial perforation/dissection, and access site complications. Acute systemic complications were present in nine patients, predominantly renal and cardiac complications. An endoleak noted at any time occurred in 25% of patients, with 40% of those requiring a secondary intervention. Two patients suffered late aneurysm rupture due to a type I endoleak and graft infection. Kaplan-Meier analysis revealed 5-year freedom from secondary intervention of 72.4%; freedom from aneurysm-related death of 93.9%; and probability of survival based on all-cause mortality of 60.1%. Endovascular treatment with the modular AneuRx Stent Graft System is safe and effective, producing acceptable rates of disease-free survival and mid-term clinical outcome.

Morphological and functional modifications of the aneurysm-endograft complex following endoluminal treatment of abdominal aortic aneurysms

The aim of the study was to evaluate quantitatively the main morphological changes of the abdominal aortic aneurysm (AAA)-endograft (EG) complex following endovascular repair of infrarenal AAA and to evaluate the functional consequences of these changes in terms of rate of complications (endoleaks and thrombosis). We also assessed whether these morphological and functional changes were related to the size of the AAA and to the type of EG used. Eighty-five patients (M/F=82/3; mean age at time of operation 70.5+/-3.5 years, range 49.9-89.6 years) who underwent endovascular treatment of infrarenal AAA between April 1997 and October 2004 with a follow-up of at least 1 month were considered. All images of 408 preoperative and postoperative computed tomography (CT) studies were reviewed. Statistical analysis was performed with log-rank test on the 85 patients grouped according to AAA diameter <50 mm or < or =50 mm, and on 75 patients grouped according to EG device used (AneuRx, Talent or Excluder). Morphological and dimensional changes involved the diameter (six cases) and length (14 cases) of AAA proximal neck, diameter (36 cases) and length (51 cases) of the aneurysm sac and shape of the stent-graft (47 cases). The prevalence of endoleaks was 37.6% whereas endoluminal thrombosis was observed in 27.1% of patients. AAA growth was significantly correlated (p=0.002) with the preprocedural diameter of the aneurysm sac whereas shrinkage was significantly correlated (p=0.0005) with the EG used. AAA growth was correlated with the diameter of the aneurysm sac while shrinkage was correlated with the EG used. During follow-up after endovascular repair, patients require careful evaluation of the morphological and dimensional features of the AAA and EG to promptly identify any changes that can anticipate major complications and even conversion to conventional surgery.

Percutaneous Thoracic and Abdominal Aortic Aneurysm Repair: Techniques and Outcomes

Endovascular repair of infrarenal abdominal aortic aneurysms (EVAR) has become a widely accepted treatment modality. The conventional approach of an EVAR involves bilateral groin incisions to expose the femoral arteries followed by introducer sheath placement, which is typically performed with the use of general or epidural anesthesia. As technology trends toward less invasive methods and sheath sizes become smaller, the use of a total percutaneous approach to endovascular repair of aortic pathology is becoming more common. In this review, we present a brief history of percutaneous closure devices for common femoral artery access, factors important in patient selection, the technique of performing a percutaneous EVAR procedure, early and late complications, and overall outcomes of percutaneous approaches for the endovascular treatment of aortic pathology.

Percutaneous repair of abdominal aortic aneurysm

Objective Percutaneous treatment of an abdominal aortic aneurysm (AAA) is feasible, but is associated with a unique set of risks. A comparison of Excluder endograft deployment with femoral artery cutdown (FAC) versus percutaneous femoral access (PFA) for treatment of infrarenal AAA was undertaken. Methods A single-institution, controlled, retrospective review was carried out in patients who underwent either bilateral FAC or bilateral PFA for endovascular repair of infrarenal AAA with the Gore bifurcated Excluder endograft between March 1999 and November 2003. To November 2000, 35 patients underwent bilateral FAC; since then, 47 patients have undergone bilateral PFA. All have been followed up for at least 30 days. Results Mean AAA size was 5.7 cm in the FAC group and 6.0 cm in the PFA group. During hospitalization there were six access-related complications in the FAC group; three required early surgical intervention. In the PFA group nine perioperative access-related complications occurred, all consisting of either hemorrhage or arterial occlusion; seven required additional intervention, and were recognized and ameliorated while the patient was still in the operating room. At 30-day follow-up there were no additional access-related complications in the PFA group. There were eight other access-related complications in eight additional patients who underwent FAC. In patients undergoing bilateral PFA total operative time was shorter (PFA 139 minutes vs FAC 169 minutes; P = .002), total in-room anesthesia time was less (PFA 201 minutes vs FAC 225 minutes; P < .008), and use of general anesthesia was reduced ( P < .001). No significant differences were observed between groups with respect to estimated blood loss (PFA 459 mL vs FAC 389 mL; P = .851). Conclusion Complete percutaneous treatment of AAA may have some advantages over open femoral artery access, but it is not free from risk. Percutaneous treatment of AAA can be completed successfully in most patients, but should be performed at an institution where conversion to an open procedure can be completed expeditiously if necessary.

Secondary conversion due to failed endovascular abdominal aortic aneurysm repair.

Since Parodi et al reported their initial experience with endograft placement in patients with abdominal aortic aneurysm (AAA) more than a decade ago, endovascular repair has become an increasingly accepted treatment option for aneurysmal disease. Currently three endovascular grafts have been approved by the US Food and Drug Administration (FDA), namely, AneuRx, Ancure, and Excluder, and a number of other devices are at various stages of FDA review. Endovascular repair of infrarenal AAA has been extensively investigated, with encouraging short-term results. There is little doubt that endovascular repair of AAA is equivalent to open repair in the short term. The enthusiasm for this minimally invasive treatment is driven in part by shorter hospital course, decreased anesthetic risk, and expedient convalescent period, compared with the conventional open operation. Along with numerous positive short-term and mid-term reports of AAA endovascular repair, a growing number of reports are beginning to reveal some of the limitations of this evolving technology. Problems with device integrity, component separation, migration, infection, iliac limb occlusion, and aneurysm sac expansion with and without the presence of endoleak have been described. Many of these problems have resulted in device explantation and repair of the aneurysm with an open surgical approach. Explantation of an endovascular graft is reported as primary conversion if it is removed at the original endovascular grafting procedure, and as secondary conversion if it is removed sometime after the original endovascular grafting procedure. Clearly the rate of primary conversion has been significantly reduced with improved device design, patient selection, and increasing operator experience. Recently several investigators reported their rate of secondary conversion. Lyden et al evaluated 110 patients who received endovascular AAA treatment, 5 (4.5%) of whom required secondary conversion. Dattilo et al reported a secondary conversion rate of 2.2% (8 patients) over 7 years in 362 AAA endovascular grafts. Finally, Ohki et al, in a 9-year experience with 239 endovascular grafts, reported a secondary conversion rate of 2.1% (5 patients). In this article we review our experience in patients with late endovascular graft clinical failure in whom secondary conversion was required. In addition, we examine the indications, operative strategies, and technical maneuvers that may facilitate endograft explantation.

Percutaneous endoprosthesis for treatment of aortic aneurysms.

The purpose of this study was to define the clinical utility of stent-grafts for endoluminal treatment of infrarenal abdominal aortic aneurysms (AAAs). In a prospective study involving three centers, bifurcated stent-grafts for endovascular repair of infrarenal AAAs were implanted in 295 patients. Patient selection was based on anatomic suitability. For analysis of the initial and follow-up results the patients were divided in three subgroups. Group 1 included patients treated between August 1994 and April 1996 with use of the original stent-graft device; group 2 comprised patients treated between May 1996 and December 1997 with the refined stent-graft device, and group 3 comprised patients treated with a newly designed bifurcated stent-graft device. In group 1 (n = 111) the primary technical success was 82%. The procedure had to be converted to surgery in four patients. Endoleaks immediately after the procedure were observed in 16 patients. The initial technical success in subgroup 2 (n = 159) was 96%. One patient required surgical repair, and five others had immediate perigraft flow due to reperfusion via lumbar arteries. For group 3 (n = 28) the primary technical success rate was 89%. Endoleaks due to back-bleeding via lumbar arteries were demonstrated in three patients. Minor and major complications related to the intervention, including two perioperative deaths, were observed in 24 patients (8%). Serious problems such as distal migration or disconnection of the stent-graft were detected during follow-up in five patients. Delayed aortic rupture occurred in three patients who survived after successful surgical repair. Based on the initial results and a limited follow-up of 35 months, we believe endoluminal repair of infrarenal AAA with use of bifurcated endografts may be a feasible alternative to conventional surgery, especially for patients at high surgical risk. However, at the present time there are major concerns with respect to the structural integrity of stent-graft material and the fate of the proximal aortic cuff in the long-term time frame.

Feasibility of endovascular repair of abdominal aortic aneurysms with local anesthesia with intravenous sedation

Purpose: Local anesthesia has been shown to reduce cardiopulmonary mortality and morbidity rates in patients who undergo selected peripheral vascular procedures. The efforts to treat abdominal aortic aneurysms (AAAs) with endovascular techniques have largely been driven by the desire to reduce the mortality and morbidity rates as compared with those associated with open aneurysm repair. Early results have indicated a modest degree of success in this goal. The purpose of this study was to investigate the feasibility of endovascular repair of AAAs with local anesthesia. Methods: During a 14-month period, 47 patients underwent endovascular repair of infrarenal AAAs with local anesthesia that was supplemented with intravenous sedation. Anesthetic monitoring was selective on the basis of comorbidities. The patient ages ranged from 48 to 93 years (average age, 74.4 ± 9.8 years). Of the 47 patients, 55% had significant coronary artery disease, 30% had significant chronic obstructive pulmonary disease, and 13% had diabetes. The average anesthesia grade was 3.1, with 30% of the patients having an average anesthesia grade of 4. The mean aortic aneurysm diameter was 5.77 cm (range, 4.5 to 12.0 cm). All the implanted grafts were bifurcated in design. Results: Endovascular repair of the infrarenal AAA was successful for all 47 patients. One patient required the conversion to general anesthesia to facilitate the repair of an injured external iliac artery via a retroperitoneal approach. The operative mortality rate was 0. No patient had a myocardial infarction or had other cardiopulmonary complications develop in the perioperative period. The average operative time was 170 minutes, and the average blood loss was 623 mL (range, 100 to 2500 mL). The fluid requirements averaged 2491 mL. Of the 47 patients, 46 (98%) tolerated oral intake and were ambulatory within 24 hours of graft implantation. The patients were discharged from the hospital an average of 2.13 days after the procedure, with 87% of the patients discharged less than 48 hours after the graft implantation. Furthermore, at least 30% of the patients could have been discharged on the first postoperative day except for study protocol requirements for computed tomographic scanning at 48 hours. Conclusion: This is the first reported series that describes the use of local anesthesia for the endovascular repair of infrarenal AAAs. Our preliminary results indicate that the endovascular treatment of AAAs with local anesthesia is feasible and can be performed safely in a patient population with significant comorbidities. The significant potential advantages include decreased cardiopulmonary morbidity rates, shorter hospital stays, and lower hospital costs. A definitive evaluation of the benefits of local anesthesia will necessitate a direct comparison with other anesthetic techniques. (J Vasc Surg 1999;29:793-8.)

Initial experience with endovascular aneurysm repair: Comparison of early results with outcome of conventional open repair

Purpose: To determine the safety, effectiveness, and problems encountered with endovascular repair of abdominal aortic aneurysm (AAA). Initial experience with endoluminal stent grafts was examined and compared with outcome for a matched concurrent control group undergoing conventional operative repair of AAA. Methods: Over a 3-year period, 30 patients underwent attempts at endovascular repair of infrarenal AAA. Of the 28 (93%) successfully implanted endografts, 8 were tube endografts, 8 bifurcated grafts, and 12 aortouniiliac grafts combined with femorofemoral bypass. Most of the procedures were performed in the past year because the availability of bifurcated and aortoiliac endografts markedly expanded the percentage of patients with AAA who might be treated with endoluminal methods. The follow-up period ranged from 1 to 44 months, with a mean value of 11 months. Results: Endovascular procedures demonstrated significant advantages with respect to reduced blood loss (408 versus 1287 ml), use of an intensive care unit (0.1 versus 1.75 days), length of hospitalization (3.9 versus 10.3 days), and quicker recovery (11 versus 47 days). Although the total number of postoperative complications was identical for the two groups, the nature of the complications differed considerably. Local and vascular complications characteristic of endovascular repair could frequently be corrected at the time of the procedure and tended to be less severe than systemic or remote complications, which predominated among the open surgical repair group. On an intent-to-treat basis, 23 (77%) of the 30 AAAs were successfully managed with endoluminal repair. The seven (23%) failures were attributable to two immediate conversions caused by access problems, three persistent endoleaks, one late conversion caused by AAA expansion, and one late rupture. Conclusions: Although less definitive than those for conventional operations, these early results suggest that endovascular AAA repair offers considerable benefits for appropriate patients. The results justify continued application of this method of AAA repair, particularly in the treatment of older persons at high risk. (J Vasc Surg 1998;27:992-1005.)

Abdominal aortic aneurysm repair using the meadox/vanguard prosthesis: Indications, implantation technique, and results

The purpose of developing percutaneously placed endoluminal stent-grafts for the treatment of aortic aneurysms is to avoid major intra-abdominal surgery and related morbidity and mortality. To define its clinical utility, the authors prospectively studied polyester-covered nitinol stents for the treatment of infrarenal abdominal aortic aneurysms (AAAs). Since 1994, the authors implanted in a total of 228 patients nonbifurcated or bifurcated stent-grafts based on a self-expandable nitinol framework covered with a thin polyester fabric for the endovascular repair of infrarenal AAA. The patient cohort was divided into two subgroups: Group 1 (n = 120) consisted of patients treated with use of the original stent-graft; Group 2 (n = 108) comprised patients treated with the refined stent-graft. Preprocedural evaluation with precise determination of the length and diameter of the proximal neck and the common iliac arteries was based on spiral computed tomography, intra-arterial angiography, and magnetic resonance angiography. The initial technical success rates in patients of Group 1 presenting with a type A aneurysm (n = 9), and type B or C aneurysms (n = 111) were 78% and 82%, respectively. Minor and major complications, including one 30-day mortality, were observed in 14 patients (11.7%). With refinement of the polyester cover as a consequence from our initial experiences, we achieved in Group 2 for type A (n = 8), and type B or C aneurysms (n = 100) primary success rates of 100% and 97%, respectively. The rate of local and remote complications in this group was 6.5%. Based on our initial and mid-term results, endoluminal repair of infrarenal AAA with use of straight or bifurcated stent-grafts is a feasible alternative to conventional surgical repair associated with a low rate of morbidity and mortality.