Short- and Midterm Outcomes of Open Repair and Fenestrated Endografting of Pararenal Aortic Aneurysms in a Concurrent Propensity-Adjusted Comparison

Purpose: To compare outcomes of patients treated for pararenal aortic aneurysms using fenestrated endovascular aneurysm repair (fEVAR) vs open surgical repair (OSR) in 3 high-volume centers. Materials and Methods: A multicenter retrospective analysis was conducted of 200 pararenal abdominal aortic aneurysm patients electively treated with OSR (n=108) or fEVAR (n=92) from 1998 to 2015 at 3 tertiary institutions. Endpoints were 30-day morbidity and mortality, late reinterventions, visceral artery occlusion, and mortality. Analysis was conducted on the entire population and on a propensity score–matched population constructed on age, gender, coronary artery disease (CAD), and chronic renal failure. Results: In the total cohort, fEVAR patients were significantly (p<0.001) older and had higher frequencies of CAD (p<0.001) and previous stroke (p=0.003). OSR patients had higher risk of perioperative morbidity (OR 2.5, 95% CI 1.09 to 5.71, p=0.033), specifically respiratory failure (OR 4.06, 95% CI 1.12 to 4.72, p=0.034). These findings were confirmed in the propensity-adjusted analysis, where cardiac complications were also higher after OSR (OR 12.8, 95% CI 0.07 to 0.21, p=0.02). No difference in perioperative mortality (2.2% in fEVAR vs 1.9% in OSR) was identified. Mean follow-up was 50 months (range 0–119). Four-year results showed higher survival (91.2% vs 69.3%, p=0.02) and freedom from reintervention (95.6% vs 77.8%, p=0.01) after OSR in the unmatched population, with a small but significant (p=0.021) difference in the risk of late visceral artery occlusion/stenosis after fEVAR. On propensity analysis, no differences in late survival were found between groups. Conclusion: fEVAR and OSR may afford similar early and midterm survival rates. Higher risks of perioperative systemic complications after OSR are counterbalanced by higher risks of late visceral vessel patency issues and need for reintervention after fEVAR. Both procedures are safe and effective in the long term in experienced centers, where patient evaluation should drive the treatment strategy.

Changes in Referral Practice, Workload, and Operative Mortality after Establishment of an Endovascular Abdominal Aortic Aneurysm Program

Purpose:

To determine the change in referral practice following establishment of an endovascular abdominal aortic aneurysm (AAA) program.

Methods:

A prospective audit of all elective admissions for AAA was established in January 1994 at the initiation of an endovascular AAA program. A comparison was made between this cohort and the elective AAA repairs performed between 1981 and 1993.

Results:

Since January 1994, 213 AAA patients (177 men; median age 73 years, range 54 to 88) have been referred for potential endovascular aneurysm repair. To date, 142 patients have undergone elective surgery (41 endovascular and 101 conventional). Between 1981 and 1993, 304 patients (255 men; median age 69 years, range 45 to 86) had elective aneurysm repair. Comparison of the two time periods has revealed significant increases in the number of tertiary referrals (41.8% versus 9.5%, p < 0.01), annual operations (50 versus 23, p < 0.05), and overall mortality (12% versus 6.7%, p < 0.05), the latter attended by a significant increase in cardiorespiratory comorbidity.

Conclusions:

The higher elective AAA mortality rate since the establishment of an endovascular program reflects a change in referral practice and may be directly attributable to an increase in the number of high-risk patients. An endovascular AAA program has clinical and financial implications for the hospital concerned.

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

PURPOSE

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Anaesthesia for endoluminal repair of abdominal aortic aneurysms

An audit of 100 patients undergoing elective abdominal aortic surgery either by open aortic repair (OAR group 50 patients) or endovascular aortic repair (EAR group 50 patients) was undertaken to document changes in anaesthetic technique and perioperative outcome. The data for the OAR group was collected retrospectively and thatfor the EAR group prospectively. Combined general anaesthesia and thoracic epidural anaesthesia was used in 44 of the OAR group whereas lumbar central neural blockade alone was used in 47 of the EAR group. The major differences between the two groups were that intraoperative blood loss was significantly less in the EAR group (OAR 1,674 +/- 1,008 ml, EAR 459 +/- 350 ml, P<0.001) and that no patient in the EAR group required admission to the Intensive Care Unit (ICU), whereas ICU time for the OAR patients was 29 +/- 22 hours. Hospital stay was also significantly different between the two groups (OAR 13 +/- 6 days, EAR 5 +/- 3 days, P<0.001). Major complications occurred in 20patients in the OAR group but only 4patients in the EAR group (P<0.001). EAR reduces blood loss, the requirement for ICU admission, and hospital stay. Central neural blockade is a satisfactory anaesthetic technique for EAR.

Sigmoid ischemia and the inflammatory response following endovascular abdominal aortic aneurysm repair

PURPOSE

To assess the relationship between sigmoid colonic perfusion, endotoxemia, and cytokine generation in patients undergoing elective open repair (OR) or endovascular repair (EVR) of infrarenal abdominal aortic aneurysms (AAA).

METHODS

Ten patients (9 males; average age 67.6 +/- 2.5 years, mean aneurysm diameter 6.9 +/- 0.6 cm) undergoing OR were compared to 10 patients (all males; average age 70.3 +/- 2.6 years, mean aneurysm diameter 6.5 +/- 0.5 cm) whose repair was performed using the EVR technique. The partial pressure of the carbon dioxide gap (PCO2gap = tissue PCO2 - arterial PCO2) of the sigmoid colonic mucosa was measured using a silicone tonometer to evaluate bowel perfusion. Blood samples were collected into pyrogen-free heparinized tubes for quantification of plasma concentrations of endotoxin, tumor necrosis factor alpha (TNF-alpha), and interleukin 6 (IL-6) before, during, and after aortic repair.

RESULTS

Patients in the OR group had a significantly greater increase in PCO2gap, suggesting a greater degree of bowel ischemia compared to the EVR group. This was associated with significantly greater postoperative concentrations of endotoxin, TNF-alpha, and IL-6 in the OR group. A significant correlation was found between PCO2gap, IL-6, and postoperative core temperature.

CONCLUSIONS

The results suggest that the degree of bowel ischemia, endotoxemia, and cytokine generation following elective infrarenal AAA reconstruction may be reduced if the endovascular technique is used instead of conventional surgery.

Abdominal aortic aneurysm in high-risk patients: short- to intermediate-term results of endovascular repair

PURPOSE

To assess the safety and efficacy of endovascular repair of abdominal aortic aneurysm in high-risk patients during the short to intermediate term.

MATERIALS AND METHODS

Endovascular aneurysm repair was performed in 50 patients considered too high risk for conventional repair. Stent-grafts were inserted through surgically exposed femoral arteries with fluoroscopic guidance. The anesthetic technique was epidural in 36 patients, general in 12, and local in two. Aortouniiliac stent-grafts were inserted in 42 patients and aortoaortic in eight.

RESULTS

There were no deaths and no conversions to open surgical repair. The primary success rate (complete aneurysm exclusion according to CT criteria) was 88% (44 of 50). The secondary, clinical, and continuing success rates were all 98% (49 of 50). Surgical time was 196 minutes +/- 67 (mean +/- SD), blood loss was 284 mL +/- 386, and volume of contrast material administered was 153 mL +/- 64. The time from the end of the surgery to resumption of a normal diet was 0.58 days +/- 0.56, to ambulation was 1.22 days +/- 0.77, and to discharge from the hospital was 3.63 days +/- 1.60. Wound problems accounted for the majority of complications. There were no instances of pulmonary failure, renal failure, stent-graft migration, or late leakage.

CONCLUSION

Endovascular repair of abdominal aortic aneurysm is feasible in two-thirds of high-risk patients, with a low mortality and high success rate during the short to intermediate term.