Complications in the endovascular repair of abdominal aortic aneurysms: a risk factor analysis.

OBJECTIVES: to identify risk factors for complications following endovascular repair of abdominal aortic aneurysms (AAAs). MATERIALS AND METHODS: endovascular AAA exclusion was attempted in 64 patients. Patient characteristics, anatomic features of the aneurysm, operative technical aspects, and the experience of the teams were correlated with mortality, occurrence of endoleak, and other complications. Perioperative complications were graded following the recommendations of the Ad Hoc Committee on reporting standards. For the assessment of correlation between risk factors and outcomes a logistic regression analysis was used. RESULTS: complications were observed in 43% of the procedures and were classified as mild (24%), moderate (55%) or severe (21%). American Society of Anaesthesiology (ASA) risk class 3 or 4, and advanced age were independent risk factors for perioperative death and complications. Adjuvant procedures or overstenting of the renal arteries with the uncovered part of the stent were not associated with increased risk of complications. Nevertheless, in four of 24 overstented renal orifices, a renal infarction or ischaemia of the kidney was observed on a postoperative CT scan. Advanced experience was associated with less complications, less endoleaks, and shorter operating time. CONCLUSIONS: high age and medical co-morbidity were associated with increased risk for perioperative complications and death. Additional perioperative procedures are usually well tolerated. With greater experience in endovascular AAA grafting the incidence of complications and endoleaks decreased.     

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.)     

Aneurysm morphology as a predictor of endoleak following endovascular aortic aneurysm repair: do smaller aneurysm have better outcomes?

Since the Food and Drug Administrations' approval of endovascular devices for abdominal aortic aneurysm (AAA) repair, clinicians have been relaxing the strict inclusion criteria present during the clinical trials. Although the long-term natural history of endoleaks remains unclear, attachment site leaks (type I) are believed to represent an ongoing risk for future rupture. We reviewed our experience with endovascular AAA repair to elucidate factors that predispose toward the development of endoleaks and found that larger AAAs are significantly more likely to have a short proximal neck and severe proximal angulation. These factors likely contribute to the significantly increased rate of type I endoleaks that occurred after endovascular repair of large AAAs. Small AAAs (<5) had the lowest rate of endoleaks overall (8.3%) and of type I endoleaks in particular (0%). We conclude that AAA size and morphology can be used to predict which aneurysms will experience attachment site endoleaks in their course; AAAs from 4.5 to 5 cm in diameter may be particularly well suited for endovascular repair in this regard.     

Intra-aneurysm sac pressure measurements after endovascular aneurysm repair: differences between shrinking, unchanged, and expanding aneurysms with and without endoleaks

OBJECTIVE: Our objective was to study intra-aneurysm pressure after endovascular aneurysm repair (EVAR) in shrinking, unchanged, and expanding abdominal aortic aneurysms (AAAs) with and without endoleaks. METHODS: Direct intra-aneurysm sac pressure measurement (DISP) by percutaneous translumbar puncture of the AAA under fluoroscopic guidance was performed 46 times during the follow-up of 37 patients (30 men; median age, 73 years [range, 58-82 years]; AAA diameter: median, 60 mm [range, 48-84 mm]). Three patients were included in two different groups because DISP was performed more than once with different indications. Tip-pressure sensors mounted on 0.014-inch guidewires were used for simultaneous measurement of systemic and AAA sac pressures. Mean pressure index (MPI) was calculated as the percentage of mean intra-aneurysm pressure relative to the simultaneous mean intra-aortic pressure. RESULTS: Median MPI was 19% in shrinking (11 patients), 30% in unchanged (10 patients), and 59% in expanding (9 patients) aneurysms without endoleaks. Pulse pressure was also higher in expanding (10 mm Hg) compared with shrinking (2 mm Hg; P <.0001) AAAs. Four of the nine patients with expanding AAAs underwent five repeated DISPs later in the follow-up, and MPIs were consistently elevated. Seven of the 10 patients with unchanged AAAs without endoleaks underwent further computed tomography follow-up after DISP; 2 expanded (MPI, 47%-63%), 4 shrank (MPI, 21%-30%), and 1 remained unchanged (MPI, 14%). Type II endoleaks (6 patients, 7 DISPs) were associated with wide range of MPI (22%-92%). Successful endoleak embolization (n = 4) resulted in pressure reduction. CONCLUSIONS: Intra-aneurysm sac pressure measurement is an important adjunctive for EVAR evaluation, possibly allowing early detection of failures. High pressure is associated with AAA expansion and low pressure with shrinkage. Type II endoleaks can be responsible for AAA pressurization, and successful embolization appears to result in pressure reduction.     

Endovaskuläre AAA-Therapie

Purpose. We analyzed the clinical efficacy of endovascular AAA repair in midterm follow-up and scrutinized the causes of graft-dependent endoleaks (type I EL). For this purpose, we investigated whether a restrictive patient selection can reduce the incidence of type I EL. Patients and results. A consecutive series of 83 patients who underwent elective endovascular AAA repair during 4/1995 and 9/1999 was analyzed. Mean follow-up was 12 months. Twenty tube grafts and 63 bifurcated grafts were used. With the help of a risk score classifying preoperative AAA morphologies into three risk groups, morphological AAA difficulties and clinical outcomes were set in reference and morphological alterations of the crucial fixation sites were amassed. Perioperative mortality was 1 of 83 (1.2%) and primary technical success 80 of 83 (96.4%). We observed one rupture 36 months postoperatively that responded to endovascular treatment. Conversion was 6 of 83 (7.2%). Type I EL occurred in 13 of 83 patients (15.7%). Of 13 type I EL patients, 9 (69.2%) responded to secondary endovascular treatment, while 4 of 13 patients (30.8%) had to be converted due to type I EL. While 70 of 83 patients (84.3%) without type I EL showed a significant decrease of maximum AAA diameter (D_max) 12 months postoperatively, D_max did not show shrinkage in 13 of 83 patients (15.7%) with type I EL (p=0.0035). In 4 of 20 patients (20%) treated with tube grafts, type I EL occurred besides a significant dilatation of the distal aortic neck 12 months postoperatively, whereas in 16 of 20 patients (80%) treated with tube grafts, neither type I EL nor a significant dilatation of the distal aortic neck was observed (p=0.0354). Of 63 patients treated with bifurcated devices, 9 (14.3%) showed type I EL and a significant dilatation of iliac artery diameters 18 months postoperatively, while 54 of 63 patients (85.7%) without type I EL did not show a significant expansion (left common iliac artery p=0.0269, right common iliac artery p=0.0071). We found a significant relationship between preoperative AAA morphologies with a higher risk score and the occurrence of type I endoleaks (p=0.022). Conclusions. The causes of the complications in the cohort observed were morphological alterations of the aortoiliac vessels, technical difficulties regarding the exact fitting of endovascular grafts, or a combination of these problems. Restrictive morphological patient selection, precise preoperative imaging, and differentiated graft choice as well as correct fitting of the graft will have the potential to decrease the incidence of type I endoleaks in the future.     

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.     

Impact of the introduction of endovascular aneurysm repair in high-risk patients on our practice of elective treatment of infrarenal abdominal aortic aneurysms

The aim of this work was to evaluate, in terms of activity and immediate postoperative results, the modifications of our elective surgical treatment of infrarenal abdominal aortic aneurysms (AAAs) resulting from the use of stent grafts to treat AAAs, following the recommendations issued by the French Health Products Safety Agency (AFSSAPS) in December 2003. This monocentric and retrospective study used the clinical data of patients operated on for asymptomatic AAA between January 2001 and December 2006. Endovascular treatment of AAAs with aortic stent grafts was introduced in our current practice in January 2004, following the recommendations of the AFSSAPS (high-risk patients for open surgery presenting with an AAA > or =50 mm). Group I was composed of patients operated on between January 2001 and December 2003 according to the standard open technique. Group II was composed of patients operated on between January 2004 and December 2006 with either standard open surgery or endovascular surgery. The main criteria of evaluation were the number of operated patients, their American Society of Anesthesiology (ASA) score of surgical risk, and the intrahospital morbidity and mortality. The number of treated patients significantly increased between these two periods (group I n = 49, group II n = 88, with 38 endovascular treatments; p < 0.001), without any changes in average age (70 vs. 72 years), percentage of men (93.7% vs. 95.5%), and mean AAA size (57.8 vs. 56 mm) between the two groups. ASA scores were significantly higher in group II (ASA III and IV, group I = 20.4% vs. group II = 55.7%; p < 0.0001), whereas the intrahospital mortality rate (4.1% vs. 3.4%) and the rate of major postoperative complications (16.3% vs. 11%) have remained stable. In group II, the median duration of hospitalization was significantly reduced (12 vs. 9 days, p < 0.001). In conclusion, in our center, following the AFSSAPS recommendations, the introduction of endovascular treatment has enabled us to electively treat a greater number of AAA patients with higher surgical risk, without aggravating the immediate postoperative results.     

Predictors of survival following open and endovascular repair of abdominal aortic aneurysms

Clinical decision making for asymptomatic abdominal aortic aneurysms (AAAs) weighs risk of aneurysm rupture, treatment hazards, and overall survival expectations. AAA diameter is the primary parameter in assessing rupture risk. Perioperative risk assessment has been extensively studied, and in-hospital mortality has been reduced to less than 8% with higher-risk open repair and less than 3% with endovascular repair. The purpose of this report is to determine risk factors that predict 2-year survival following open and endovascular AAA repair. We studied 334 patients enrolled in a multicenter clinical trial evaluating an endovascular graft in comparison to standard open repair of infrarenal AAA. Demographic, medical history, physical examination, laboratory, anatomic, procedural, and standardized risk score system variables were analyzed in a multivariable Cox proportional hazard model. Overall survival was 89% at 2 years. Heart disease, cancer, and stroke were the most common causes of death, and no deaths were due to AAA rupture. Cox modeling demonstrated that there were several independent predictors for death after AAA repair: smaller body mass index (p=0.005), Society for Vascular Surgery pulmonary risk score >or=1 (p=0.005), history of erectile dysfunction (p=0.008), history of heart valve replacement (p=0.008), lower preoperative platelet count (p=0.012), larger ratio of AAA diameter/proximal neck diameter (p=0.020), and lower ankle-brachial index (p=0.031). Age, gender, and open or endovascular treatment group are not significant independent risk factors for 2-year mortality in this study. Clinical, laboratory, and anatomic factors predict survival after open and endovascular repair of AAAs. With progressive reduction of in-hospital mortality, assessment of patient longevity after AAA repair has become a more important factor in clinical decision making. Use of valid predictors of patient survival will optimize resource utilization and improve overall patient outcomes. Better selection of patients for any method of repair may improve overall utility more than choice of open or endovascular techniques.     

Endoleaks after endovascular aneurysm repair lead to nonuniform intra-aneurysm sac pressure

OBJECTIVE: This was a study of intra-aneurysm sac pressures in patients who presented with endoleaks after endovascular repair (EVAR) of abdominal aortic aneurysms (AAA). METHODS: Twenty-five patients (18 men, 7 women) with endoleaks, age (IQR 68 to 80), underwent 31 direct intra-aneurysm sac pressure measurements, DISP at 16 months after EVAR (IQR, 14 to 26 months). Diameter of AAA was 59 mm (IQR, 52 to 67 mm). Six patients underwent DISP twice. Tip-pressure sensors were used through direct translumbar puncture of the AAA except in three patients (transabdominal puncture in 2; endoluminal in 1). Mean pressure index (MPI) was calculated between simultaneously registered intra-aneurysm sac and systemic pressures. Values presented are medians with interquartile range (IQR). RESULTS: Type I endoleaks (n = 1) showed MPI of 93% in the nidus and 62% in the thrombus. Type II endoleaks were associated with lower MPIs in the thrombus (35%; IQR 24% to 38%) when AAAs shrank (n = 4) compared with when the AAAs remained unchanged (n = 11; MPI, 78%; IQR, 47% to 85%) or expanded (n = 6; MPI, 74%; IQR, 58% to 87%; P = .019). The nidus of type II endoleaks (MPI, 79%; IQR, 70% to 90%) had higher pressure than the thrombus (45%, IQR, 34% to 85%; P = .047; n = 7). Successful embolization of type II endoleaks led to AAA shrinkage (n = 3; MPI reduction, 13% to 31%) or diameter stability (n = 3; unchanged MPIs, 37% to 44%). Type III endoleaks (n = 3) had MPIs in the thrombus of 33% to 70%. CONCLUSIONS: Endoleaks after EVAR pressurize the AAA sac nonuniformly, with higher, near-systemic, pressure in the endoleak nidus compared with the thrombus. Nevertheless, type II endoleaks in shrinking AAAs have lower intra-sac pressure than expanding or stable aneurysms, and successful endoleak embolization reduces pressure.     

Abdominal aortic aneurysm rupture rates: A 7-year follow-up of the entire abdominal aortic aneurysm population detected by screening

Purpose: The goal of the current study was to identify the risk of rupture in the entire abdominal aortic aneurysm (AAA) population detected through screening and to review strategies for surgical intervention in light of this information. Methods: Two hundred eighteen AAAs were detected through ultrasound screening of a family practice population of 5394 men and women aged 65 to 80 years. Subjects with an AAA of less than 6.0 cm in diameter were followed prospectively with the use of ultrasound, according to our protocol, for 7 years. Patients were offered surgery if symptomatic, if the aneurysm expanded more than 1.0 cm per year, or if aortic diameter reached 6.0 cm. Results: The maximum potential rupture rate (actual rupture rate plus elective surgery rate) for small AAAs (3.0 to 4.4 cm) was 2.1% per year, which is less than most reported operative mortality rates. The equivalent rate for aneurysms of 4.5 to 5.9 cm was 10.2% per year. The actual rupture rate for aneurysms up to 5.9 cm using our criteria for surgery was 0.8% per year Conclusion: In centers with an operative mortality rate of greater than 2%, (1) surgical intervention is not indicated for asymptomatic AAAs of less than 4.5 cm in diameter, and (2) elective surgery should be considered only for patients with aneurysms between 4.5 and 6 cm in diameter that are expanding by more than 1 cm per year or for patients in whom symptoms develop. In centers with elective mortality rates of greater than 10% for abdominal aortic aneurysm (AAA) repair, the benefit to the patient of any surgical intervention for an asymptomatic AAA of less than 6.0 cm in diameter is questionable. (J Vasc Surg 1998;28:124-8.)     

肾动脉下腹主动脉瘤腔内治疗后并发症的防治

目的　总结肾动脉下腹主动脉瘤腔内治疗后常见并发症的预防与处理。　方法对已施行腔内治疗的 71例肾下腹主动脉瘤患者的临床资料进行回顾性分析 ,讨论常见并发症发生的原因、处理、结果及预后。　结果　 71例接受腔内治疗的肾动脉下腹主动脉瘤患者技术成功率1 0 0 % ,无中转开腹手术者。原发性内漏 8例 ,神经并发症合并急性血栓形成 1例。一过性缺血性肠炎 2例。无肾动脉梗死、肢体栓塞等并发症。平均随访时间 (2 6± 5)个月。围手术期病死率 1 3 % (1 /71 ) ,总病死率 4 2 % (3/ 71 )。死亡原因 2例为急性心肌梗死 ,1例为急性心功能衰竭。随访过程中发现 3例原发性内漏转为持续性内漏 ,另发现继发性内漏 4例。本组患者 1个月后内漏发生率 9 8%(7/ 71 )。 2例继发性Ⅰ型内漏随访中瘤体增大 ,1例进行二期腔内治疗。　结论　动脉瘤的腔内治疗具有创伤小、技术操作可行、效果肯定的优点 ,内漏血是该技术主要并发症。对漏血量及瘤体有增大趋势的内漏应积极处理     

Endovascular aneurysm repair at 5 years: does aneurysm diameter predict outcome?

OBJECTIVE: The appropriate size threshold for endovascular repair of small abdominal aortic aneurysms (AAA) is unclear. We studied the outcome of endovascular aneurysm repair (EVAR) as a function of preoperative aneurysm diameter to determine the relationship between aneurysm size and long-term outcome of endovascular repair. METHODS: We reviewed the results of 923 patients treated in a prospective, multicenter clinical trial of EVAR. Small aneurysms were defined according to two size thresholds of 5.5 cm and 5.0 cm. Two-way analysis was used to compare patients with small aneurysms (<5.5 cm, n = 441) to patients with large aneurysms (> or =5.5 cm, n = 482). An ordered three-way analysis was used to compare patients with small AAA (<5.0 cm, n = 145), medium AAA (5.0 to 5.9 cm, n = 461), and large AAA (> or =6.0 cm, n = 317). The primary outcome measures of rupture, AAA-related death, surgical conversion, secondary intervention, and survival were compared using Kaplan-Meier estimates at 5 years. RESULTS: Median aneurysm size was 5.5 cm. The two-way comparison showed that 5 years after EVAR, patients with small aneurysms (<5.5 cm) had a lower AAA-related death rate (1% vs 6%, P = .006), a higher survival rate (69% vs 57%, P = .0002), and a lower secondary intervention rate (25% vs 32%, P = .03) than patients with large aneurysms (> or =5.5 cm). Three-way analysis revealed that patients with small AAAs (<5.0 cm) were younger (P < .0001) and were more likely to have a family history of aneurysm (P < .05), prior coronary intervention (P = .003), and peripheral occlusive disease (P = .008) than patients with larger AAAs. Patients with smaller AAAs also had more favorable aortic neck anatomy (P < .004). Patients with large AAAs were older (P < .0001), had higher operative risk (P = .01), and were more likely to have chronic obstructive pulmonary disease (P = .005), obesity (P = .03), and congestive heart failure (P = .004). At 5 years, patients with small AAAs had better outcomes, with 100% freedom from rupture vs 97% for medium AAAs and 93% for large AAAs (P = .02), 99% freedom from AAA-related death vs 97% for medium AAAs and 92% for large AAAs (P = .02) and 98% freedom from conversion vs 92% for medium AAAs and 89% for large AAAs (P = .01). Survival was significantly improved in small (69%) and medium AAAs (68%) compared to large AAAs (51%, P < .0001). Multivariate Cox proportional hazards modeling revealed that aneurysm size was a significant independent predictor of rupture (P = .04; hazard ratio [HR], 2.195), AAA-related death (P = .03; HR, 2.007), surgical conversion (P = .007; HR, 1.827), and survival (P = .001; HR, 1.351). There were no significant differences in secondary intervention, endoleak, or migration rates between small, medium, and large AAAs. CONCLUSIONS: Preoperative aneurysm size is an important determinant of long-term outcome following endovascular repair. Patients with small AAAs (<5.0 cm) are more favorable candidates for EVAR and have the best long-term outcomes, with 99% freedom from AAA death at 5 years. Patients with large AAAs (> or =6.0 cm) have shorter life expectancy and have a higher risk of rupture, surgical conversion, and aneurysm-related death following EVAR compared to patients with smaller aneurysms. Nonetheless, 92% of patients with large AAAs are protected from AAA-related death at 5 years. Patients with AAAs of intermediate size (5 to 6 cm) represent most of the patients treated with EVAR and have a 97% freedom from AAA-related death at 5 years.     

Durability of benefits of endovascular versus conventional abdominal aortic aneurysm repair

PURPOSE: Endovascular abdominal aortic aneurysm (AAA) repair is reported to result in less initial patient morbidity and a shorter hospital length of stay (LOS) when compared with conventional AAA repair. We sought to examine the durability of this result during the intermediate follow-up interval. METHODS: The records of all admissions for all patients who underwent AAA repair during a 26-month interval were reviewed. RESULTS: Three hundred thirty-seven (337) patients underwent procedures to repair AAAs (163 open and 174 endovascular). Endovascular procedures were performed with a variety of devices (Talent, 108; Ancure, 36; AneuRx, 26; Zenith, 2; and Cordis, 2) and configurations (141 bifurcated and 33 aortomonoiliac). The mean follow-up period was 10.6 months (endovascular repair) and 12.3 months (open repair). LOS did not significantly vary by device (P =.24 to P =.92) or configuration (P =.24). The initial median LOS for procedures was significantly shorter (P =.009) for endovascular repairs (5 days) than for open procedures (8 days). However, the patients who underwent endovascular repair were more likely to be readmitted during the follow-up interval when compared with patients who underwent open procedure. The readmission-free survival rate after AAA repair at 12 months was 95% for patients for open AAA repair versus 71% for patients for endovascular repair (P <.001). If the total hospital days were compared, including the initial and all subsequent AAA-related admissions, there was no significant difference for mean LOS for patients who underwent endovascular versus open AAA procedures (11 days versus 13.6 days; P =.21). The patients for endovascular AAA repair most commonly needed readmission for treatment of endoleak (n = 31), wound infection (n = 12), and graft limb thrombosis (n = 9). Although women had similar LOS to men for endovascular repair (P =.44), they had longer initial LOS for open AAA repair (15 versus 10 days; P =.03). After endovascular repair, women were more likely than men to be readmitted by 12 months (51% versus 71% readmission-free survival rate; P =.03) and they had longer LOS on readmission (13.2 versus 5.2 days; P =.006). No gender differences were identified for patients after open AAA repair regarding readmission-free survival rate (P =.09) or LOS on readmission (P =.98). CONCLUSION: Although initial LOS was shorter for the patients who underwent endovascular as compared with conventional AAA repair, this advantage was lost during the follow-up interval because of frequent readmission for the treatment of procedure-related complications, chiefly endoleak. These readmissions frequently involved the performance of additional invasive procedures. Gender differences existed regarding LOS and the likelihood of complications after open and endovascular AAA repair.     

Innovations in treating aortic diseases: the abdominal aorta

Patients with an abdominal aortic aneurysm (AAA) could benefit from earlier diagnosis to improve long-term outcomes. Candidate serum biomarkers for earlier AAA diagnosis include D-dimer, fibrinogen, low-density lipoprotein, high-density lipoprotein, lipoprotein(a), and the proteolytic enzymes known as matrix metalloproteinases. Furthermore, biomarkers such as brain natriuretic peptide significantly stratify perioperative risk in AAA repair. Statins significantly improve outcomes after AAA repair. They may also significantly slow AAA growth to allow pharmacologic arrest of AAA development. Recent trials have focused attention on fluid management for AAA repair. Although restrictive fluid management may significantly improve clinical outcomes, current evidence does not clearly support crystalloid or colloid for AAA repair. There may be an increased risk of renal dysfunction associated with hetastarch therapy. Endovascular repair has revolutionized the clinical management of AAAs. Recent trials have shown its significant outcome advantages. Furthermore, it is also applicable in high-risk operative cohorts and, in the future, may be suited for earlier AAA repair. This technology continues to advance with the development of branched and fenestrated grafts as well as total percutaneous endovascular AAA repair. Regardless of these advances, the clinical management of endoleaks will remain a major clinical focus. Taken together, these advances in the management of AAAs likely will significantly influence future clinical approaches to this challenging patient cohort.     

Should endovascular surgery lower the threshold for repair of abdominal aortic aneurysms?

PURPOSE: Because endovascular repair of abdominal aortic aneurysms (AAAs) is less invasive, some investigators have suggested that this increasingly popular technique should broaden the indications for elective AAA repair. The purpose of this study was to calculate quality-adjusted life expectancy rates after endovascular and open AAA repair and to estimate the optimal diameter for elective AAA repair in hypothetical cohorts of patients at average risk and at high risk. METHODS: A Markov decision analysis model was used in this study. Assumptions were made on the basis of published reports and included the following: (1) the annual rupture rate is a continuous function of the AAA diameter (0% for <4 cm, 1% for 4.5 cm, 11% for 5.5 cm, and 26% for 6.5 cm); (2) the operative mortality rate is 1% for endovascular repair (excluding the risk of conversion to open repair) and 3.5% for open repair at age 70 years; and (3) immediate endovascular-to-open conversion risk is 5%, and late conversion rate is 1% per year. The main outcome measure in this study was the benefit of AAA repair in quality-adjusted life years (QALYs). The optimal threshold size (the AAA diameter at which elective repair maximizes benefit) was measured in centimeters. RESULTS: The benefit of endovascular repair is consistently greater than that of open repair, but the additional benefit is small-0.1 to 0.4 QALYs. For men in average health with gradually enlarging AAAs with initial diameters of 4 cm, endovascular surgery reduces the optimal threshold diameter by very little: from 4.6 to 4.6 cm (no change) at age 60 years, from 4.8 to 4.7 cm at age 70 years, and from 5.1 to 4.9 cm at age 80 years. For older men in poor health, endovascular surgery reduces the optimal threshold diameter substantially (8.1 to 5.7 cm at age 80 years), but the benefit of repair in this population is small (0.2 QALYs). CONCLUSION: For most patients, the indications for AAA repair are changed very little by the introduction of endovascular surgery. Only for older patients in poor health does endovascular surgery substantially lower the optimal threshold diameter for elective AAA repair.     

Adverse events after endoluminal repair of abdominal aortic aneurysms: A comparison during two successive periods of time

Purpose: The aim of this study was to document the incidence rate of adverse events after endoluminal repair of abdominal aortic aneurysms (AAAs) during two successive periods of time. Methods: One hundred ninety patients (175 men, 15 women; mean age, 72 years) underwent endoluminal repair of AAAs in a 5 ½-year period. Adverse events were documented prospectively for all the patients throughout this interval. An adverse event was defined as any of the following events: a death within 30 days, a conversion to open repair, the need for further intervention (either open or endovascular), the need for hemodialysis, a failure to cure the AAA, and wound complications. The patients were divided into two groups—those who underwent operation in the initial 3-year period (group I; n = 75) and those who underwent operation in the subsequent 2 ½-year period (group II; n = 115). The results were analyzed for total adverse events for both periods of time and for difference in incidence rates within categories of adverse events between the two groups. Results: Eight patients (4.2%) died in the perioperative period. The endoluminal repair failed in 17 patients (8.9%), which necessitated a primary conversion to open repair at the original operation. In 88 patients, 110 adverse events occurred. There was no significant difference in the incidence rates of adverse events in patients in group I (37/75) and group II (51/115). Apart from primary conversion (P = .007), there was no significant difference in the incidence rates of adverse events between group I and group II within the following categories: perioperative (within 30 days) deaths, primary conversion, secondary conversion, supplementary endoluminal repair, intervention for lower limb ischemia, hemodialysis necessitated, failure to cure the AAA as a result of persistent endoleak, and wound complications. Conclusion: Despite improvements in technology and increasing experience, adverse events continue to occur in a relatively high proportion of patients (45%) who undergo endoluminal repair of AAA. Reporting the incidence rates of adverse events provides a more accurate picture of the morbidity rates of the endoluminal method rather than simply listing the procedures as successes or failures. The similarity in the incidence rates of adverse events in patients in group I and group II suggests that there are inherent risks in the endoluminal method rather than iatrogenic complications that occur during the learning curve with a new technique. (J Vasc Surg 1999;29:32-9.)     

An analysis of standard open and endovascular surgical repair of abdominal aortic aneurysms in octogenarians

While elective open abdominal aortic aneurysm (AAA) repair has been shown to be safe in selected octogenarians, very little is known about the role of endovascular AAA exclusion in this high-risk cohort. A retrospective review of our vascular surgical registry from January 1996 to December 2001 revealed 51 octogenarians that underwent infrarenal AAA repair. Since 1999 all octogenarians who presented for AAA repair were evaluated for preferential endovascular stent graft placement. Over the 6-year period, 35 patients underwent standard open repair while 16 patients were found to be anatomic candidates for and were treated with an endovascular stent graft. Hospital and office charts were reviewed to compare the endovascular cohort to the standard open cohort. Factors considered included patient comorbidities, perioperative data, and operative outcomes. Statistical analysis was done using Wilcoxon rank sum test and Fisher exact test. The median age for the entire group was 83 years. There were 11 females in the open group and 1 female in the endovascular group. There were no statistically significant differences in preoperative patient comorbidities between groups. Total mortality for the entire series was 11.8 per cent but this included 5 ruptured AAAs, all of which patients died, and 11 additional AAAs that were symptomatic, of which 1 patient died. Total nonruptured mortality for the entire series was 2.2 per cent (0% for the endo-group and 3.3% for the open group). There were statistically significant differences between the endovascular versus the open groups when comparing aneurysm diameter (5.6 cm vs. 6.2 cm; P = 0.016), estimated blood loss (225 cc vs. 2100 cc; P < 0.001), ICU days (0 vs. 3; P < 0.001), length of hospital stay (2 days vs. 12 days; P < 0.001), and patients with blood transfusions (1 vs. 27; P < 0.001). When comparing postoperative morbidities, 4 of the endovascular patients (25%) and 25 of the open patients (68.6%) had a complication (P = 0.006). In conclusion, endovascular stent graft treatment of nonruptured infrarenal AAAs in octogenarians led to significantly better outcomes and should probably be considered the preferred treatment whenever anatomically appropriate. Endovascular exclusion of ruptured AAAs may potentially improve future outcomes in this high-risk group.     

Significance of endoleaks after endovascular repair of abdominal aortic aneurysms: The EUROSTAR experience

OBJECTIVE: The purpose of this study was to assess the incidence, risk factors, and consequences of endoleaks after endovascular repair of abdominal aortic aneurysm. METHODS: Data on 2463 patients were collected from 87 European centers and recorded in a central database. Preoperative data were compared for patients with collateral retrograde perfusion (type II) endoleak (group A), patients with device-related (type I and III) endoleaks (group B), and patients in whom no endoleak was detected (group C). Only endoleaks observed after the first postoperative month of follow-up were taken into consideration. Regression analysis was performed to investigate statistical relationships between the occurrence and type of endoleak and preoperative patient and morphologic characteristics, operative details, type of device, and experience of the operating team. In addition, postoperative changes in aneurysmal morphology, the need for secondary interventions, conversions to open repair, aneurysmal rupture, and mortality during follow-up were compared between these study groups. RESULTS: Patients in group A had a higher prevalence of a patent inferior mesenteric artery compared with patients without endoleak. Patients in group B were treated more frequently than patients in group C by an operating team with experience of less than 30 procedures. The mean follow-up period was 15.4 months. Secondary interventions were needed in 13% of the patients. Rupture of the aneurysm during follow-up occurred in 0.52% (1/191) in group A, 3.37% (10/297) in group B, and 0.25% (5/1975) in group C. Life table analysis comparing the three study groups demonstrated a significantly higher rate of rupture in group B than in group C (P =.002). The incidence of conversion to open repair during follow-up was higher in group B than in the other two study groups (P <.01). Death was related to the aneurysm or to endovascular repair of the aneurysm in 7% of patients. Secondary outcome success, defined as absence of rupture and conversion, was significantly higher in group A and C compared with that in group B (P =.006 and P =.0001, respectively). CONCLUSIONS: The presence of device-related endoleaks correlated with a higher risk of aneurysmal rupture and conversion compared with patients without type I or III endoleaks. Type II endoleak was not associated more often with these events. Consequently, intervention in type II endoleak should only be performed in case of increase of aneurysm size.     

Conservative observational management with selective delayed repair for large abdominal aortic aneurysms in high risk patients

AIM: Abdominal aortic aneurysms (AAAs) larger than 5.5 cm should generally undergo elective repair. However, some of these patients have serious comorbid conditions, which greatly increase operative risk. This study evaluated the outcomes of nonoperative, observational management and selective delayed AAA repair in high-risk patients with large infrarenal and pararenal AAAs. METHODS: Among 226 patients with AAAs >5.5 cm, we selected 72 with AAAs 5.6-12.0 cm (mean 7.0 cm) for periods of nonoperative management because of their prohibitive surgical risks. Comorbid factors included a low ejection fraction of 15-34% (mean 22%) in 18 patients; FEV1 <50% (mean 38%) in 25; prior laparotomy in 10; and morbid obesity in 22. Follow-up was complete in the 72 patients for the 6-76 months (mean 23 months) that they were treated nonoperatively. Fifty-three patients ultimately underwent repair because of AAA enlargement or onset of symptoms after 6-72 months (mean 19 months) of observational treatment. RESULTS: Of the 72 selected patients, 54 (75%) are living and 18 (25%) are dead. Seven patients undergoing only nonoperative treatment presently survive after 28-76 months (mean 48 months). Of the 18 deaths, AAA rupture occurred in only 3 patients (4%) who had been observed for 12, 31, and 72 months before rupture. Nine other deaths (13%) occurred after 6-72 months from comorbidities unrelated to the patient's AAA. Six of the 53 patients undergoing delayed AAA repair died within 30 days of operation (11% mortality). The mortality for the 154 good risk AAA patients, who underwent prompt open or endovascular repair, was 2.2%. CONCLUSION: These data indicate that some patients with large AAAs and serious comorbidities are acceptably managed for long periods (6-76 months) by nonoperative means. Substantial delays of 12 to 76 months resulted in an AAA rupture rate of only 4%, while 13% of these patients (9 of 72) died of their comorbidities unrelated to AAA rupture or surgery and mortality in this group of patients, when operated on, was 11% (6 of 53). These findings support the selective use of nonoperative observational management in some patients with large AAAs and serious comorbidities.     

A comparison of 50 initial endoluminal endograft repairs for abdominal aortic aneurysm with 50 concurrent open repairs

PURPOSE: To review the results of our initial experience with endovascular repair of abdominal aortic aneurysm (AAA) with respect to morbidity and mortality and to compare these outcomes with those of transabdominal repair. METHODS: We reviewed the first 50 consecutive endovascular AAA repairs performed at our institution from November 1999 to January 2002. Pre-operative risk factors, intraoperative variables and post-operative outcomes were assessed. All endovascular patients were followed with periodic examination, contrast-enhanced computed tomography and/or duplex scanning. Comparison was made to 50 patients undergoing standard open repair over a similar time period. RESULTS: Fifty patients underwent endovascular AAA repair (mean age 72.5, AAA size 5.5 cm). Endovascular devices employed were manufactured by Ancure (Guidant Corp.), and AneuRx (Medtronic). Preoperative risk factors were similar to patients undergoing transabdominal repair. Mean operative time was 169 minutes and estimated blood loss was 450cc with average blood replacement of.18 units. Median ICU stay was 0 days and mean hospital stay was 2.3 nights. There were no conversions to open repair, however there was one aborted endovascular attempt. Morbidity included MI (2%), colon ischemia (1%), acute renal insufficiency (4%) and leg ischemia (4%). There was one death within 30 days. Seven endoleaks were identified (6 type II and 1 type I) and were managed angiographically. CONCLUSIONS: The short-term surgical morbidity and mortality rates for endovascular repair of AAA are acceptably low and are comparable to the transabdominal approach.