Rate and Predictability of Graft Rupture After Endovascular and Open Abdominal Aortic Aneurysm Repair: Data From the EVAR Trials

The influence of thrombus, calcification, angulation, and tortuosity of attachment sites on the time to the first graft-related complication after endovascular aneurysm repair

PURPOSE

Endovascular aneurysm repair (EVAR) is associated with high graft-related complication rates during follow-up. Anatomical fit between patient and endograft could be an important factor for successful treatment. Aim was to assess whether extent of thrombus, calcification, angulation, and tortuosity are associated with occurrence of complications after EVAR.

MATERIALS AND METHODS

Patients in either United Kingdom EVAR trial 1 or 2 were included if they had undergone EVAR within 6 months of randomization and had a preoperative computed tomography (CT) scan of adequate quality in the core laboratory. Three-dimensional CT imaging was used to assess extent of preoperative thrombus, calcification, angulation, and tortuosity in aneurysm neck and iliac segments. Cox regression modeling, adjusted for the variables tested and for known confounding variables, was used to investigate whether these factors were associated with increased rates of reported first complications.

RESULTS

A total of 217 patients with 53 first graft-related complications were analyzed after a mean follow-up of 3.6 years. Adjusted hazard ratios (95% confidence intervals, P values) for complications per unit increase of variable were 0.96 (0.92-0.99, 0.018) for neck thrombus, 1.06 (1.00-1.12, 0.044) for neck calcification, 1.02 (1.00-1.05, 0.079) for neck angulation, 1.04 (1.01-1.06, 0.011) for common iliac thrombus, 0.96 (0.93-1.00, 0.033) for common iliac calcification, and 5.96 (1.53-23.28, 0.010) for common iliac tortuosity.

CONCLUSION

Increased neck angulation and calcification and common iliac thrombus and tortuosity are associated with higher rates of graft-related complications after EVAR. Increased neck thrombus and common iliac calcification appear to protect against complications. Careful evaluation of these factors prior to EVAR might lead to lower complication rates.

Incidence of cardiovascular events and death after open or endovascular repair of abdominal aortic aneurysm in the randomized EVAR trial 1

BACKGROUND

The aim was to compare rates of myocardial infarction, stroke and cardiovascular death in patients with a large abdominal aortic aneurysm who had endovascular (EVAR) or open repair to determine whether cardiovascular mortality explains the convergence in survival curves after these procedures.

METHODS

Between 1999 and 2004, 1252 patients were randomized to EVAR or open repair in the UK EVAR trial 1. All patients were followed for death, myocardial infarction or stroke until September 2009. Cox regression was used to compare cardiovascular events and deaths between the randomized groups during different time intervals.

RESULTS

Over 5 years of follow-up, a total of 187 first non-fatal or fatal cardiovascular events (98 myocardial infarctions and 89 strokes) and 256 cardiovascular deaths occurred. Although the endovascular group had a lower cardiovascular event rate than the open repair group (2·6 versus 3·2 per 100 person-years respectively) this was not statistically significant (adjusted hazard ratio (HR) 0·83, 95 per cent confidence interval 0·62 to 1·10; P = 0·199). Overall, there was little difference in cardiovascular mortality between the randomized groups (adjusted HR 1·06, 0·83 to 1·36; P = 0·638), but a non-significant excess of cardiovascular deaths was apparent in the endovascular group during the 6-24-month interval (adjusted HR 1·44, 0·79 to 2·62; P = 0·237).

CONCLUSION

Patients who had EVAR appeared to have a lower subsequent cardiovascular event rate during all time intervals. Cardiovascular mortality was similar between the two groups overall, but more cardiovascular deaths in the EVAR group appeared to contribute to the convergence in all-cause mortality during the first 2 years.

Transverse minilaparotomy for open abdominal aortic aneurysm repair

INTRODUCTION

Traditional open surgical repair for abdominal aortic aneurysm (AAA) is a major procedure with a relatively high risk of perioperative morbidity. This article describes the results of minimally invasive open AAA repair through a transverse left upper quadrant minilaparotomy.

METHODS

Between January 2007 and June 2010, 83 consecutive patients (77 men) underwent elective or urgent repair of a nonruptured AAA through a horizontal transperitoneal left upper quadrant minilaparotomy. Postoperatively, patients were fast-tracked through a multidisciplinary recovery program.

RESULTS

Repairs were urgent in 15 patients (18%), and 10 (12%) had aortoiliac aneurysms. American Society of Anesthesiologists (ASA) scores 1 to 4 were 3.6%, 44.6%, 42%, and 11%, respectively. Median (range) age was 73 (61-87) years, AAA size was 5.9 (5.1-10) cm, body mass index was 27 (19-39) kg/m(2), operation time was 150 (85-280) minutes, blood loss was 625 (200-4150) mL, critical care bed days was 1 (0-19), and hospital stay was 4 (2-88) days. Four (4.8%) patients returned to the operating theater within the same admission. No patients required conversion to full laparotomy and none had reintervention postdischarge. Two patients (2.4%) died in the hospital, and 18 (21.7%) had postoperative adverse events, ranging from urinary retention to myocardial infarction. New-onset atrial fibrillation was the commonest of these events (11, 13.3%). Respiratory tract infection incidence was low (4.8%). Incisional herniation developed in two patients (2.4%) at a median (range) follow-up of 10 (6-25) months. Correcting for age, cardiac complications were associated with increased odds of hospital stay >4 days (odds ratio [OR], 7.59; 95% confidence interval [CI], 1.12-52.42; P = .014). Correcting for ASA score, advancing age was associated with increased risk of cardiac complications (OR, 1.18; 95% CI, 1.08-1.28; P = .001), whereas AAA screening (patient identified through screening) and maintaining higher intraoperative systolic pressure were both protective (OR, 0.24; 95% CI, 0.07-0.87; P = .018) and (OR, 0.93; 95% CI, 0.89-0.98; P = .009), respectively.

CONCLUSION

Left upper quadrant minilaparotomy is a feasible minimally invasive approach to open AAA repair. This technique is associated with low morbidity and mortality and short hospital stay, particularly in patients identified through AAA screening.