Aspartate transaminase to platelet ratio index and Model for End-Stage Liver Disease scores are associated with morbidity and mortality after endovascular aneurysm repair among patients with liver dysfunction

Abstract

Background: Liver cirrhosis dramatically increases morbidity and mortality after open surgical procedures and is often a contraindication to open repair of abdominal aortic aneurysms. However, limited data have evaluated the effect of liver disease on outcomes after endovascular repair of aortic aneurysms.

Methods: The National Surgical Quality Improvement Program was used to evaluate all nonemergent endovascular aneurysm repairs (EVARs) from 2005 to 2016. The aspartate transaminase to platelet ratio index is a sensitive, noninvasive screening tool used to screen for liver disease and was calculated for all patients. A value >0.5 was used to identify those with significant liver fibrosis. Demographics, comorbidities, and 30-day outcomes were then compared between patients with and patients without fibrosis. Additional analysis was then completed to assess the effect of increasing Model for End-Stage Liver Disease (MELD) score on 30-day outcomes. Multivariable regression was used to account for differences in baseline factors.

Results: EVAR was performed on 18,484 patients including 2286 with liver fibrosis and 16,198 without. Patients with liver fibrosis had an increased 30-day mortality (1.5% vs 2.4%; P < .01) and significantly higher rates of major morbidities including return to the operating room, pulmonary complications, transfusion, and discharge other than home. After multivariable analysis, patients with liver fibrosis had a significant increase in 30-day mortality (odds ratio [OR], 1.5; 95% confidence interval [CI], 1.1-2.1), return to the operating room (OR, 1.5; 95% CI, 1.2-1.8), pulmonary complications (OR, 1.6; 95% CI, 1.2-2.0), transfusion (OR, 1.7; 95% CI, 1.5-2.0), and discharge other than home (OR, 1.5; 95% CI, 1.3-1.8). In further analysis, mortality also increased in a stepwise fashion with increasing MELD score (MELD <10, 1.3%; MELD 10-15, 2.3%; MELD >15, 4.7%; P < .01), as did major complications (MELD <10, 7%; MELD 10-15, 11%; MELD >15, 15%; P < .01). These increases persisted in adjusted analysis.

Conclusions: Liver fibrosis significantly increases mortality and major morbidity after EVAR. The aspartate transaminase to platelet ratio index and MELD score should be used for preoperative risk stratification. Moreover, current 30-day morbidity and mortality rates among patients with MELD scores >10 exceed 5%, which is higher than the annual rupture risk for aneurysms <6 cm. Therefore, an increased size threshold of >6 cm may be warranted before EVAR in patients with liver fibrosis.

Keywords: Cirrhosis; EVAR; Liver disease; Mortality.