Aneurysms in abdominal organ transplant recipients

Abstract

Objective: The purpose of this study was to characterize the prevalence and natural history of aneurysms among abdominal transplant recipients.

Methods: This article is a retrospective review of adult patients who underwent a kidney or liver transplant at a single center between February 23, 2000, and October 6, 2011. Data were obtained by searching electronic medical records for documentation of arterial aneurysm. Abdominal aortic aneurysms (AAAs) were included if they were ≥3.0 cm in diameter, and thoracic aortic aneurysms were included if they had a diameter ≥3.75 cm. Additional data collected included recipient demographics, transplant-specific data, and characteristics of the aneurysms.

Results: There were 927 liver transplant recipients, 2133 kidney transplant recipients, 23 liver-kidney transplant recipients, and 133 kidney-pancreas transplant recipients included in our study; 127 of these patients were identified to have aneurysms (40 liver, 83 kidney, 3 liver-kidney, 1 kidney-pancreas). The overall prevalence of any aneurysm was similar for liver and kidney recipients, but the distribution of aneurysm types was different for the two groups. AAAs made up 29.6% of aneurysms in kidney transplant recipients and 11.4% of aneurysms in liver transplant recipients (P = .02). Visceral aneurysms were 10-fold as common in liver transplant recipients compared with kidney transplant recipients (47.7% of aneurysms vs 5.1% of aneurysms; P < .01). The majority of visceral artery aneurysms involved the hepatic and splenic artery. For both liver and kidney transplant recipients, most aneurysms occurred post-transplantation. All known aortic aneurysm ruptures occurred post-transplantation (25% of AAAs in liver transplant patients and 22.2% of thoracic aortic aneurysms in kidney transplant patients). There was a trend toward higher AAA expansion rates after transplantation (0.58 ± 0.48 cm/y compared with 0.41 ± 0.16 cm/y).

Conclusions: Compared with the general population, aneurysms may be more common and may have an aggressive natural history in abdominal transplant recipients. Furthermore, the types of aneurysms that affect liver and kidney transplant recipients differ. Care teams should be aware of these risks and surveillance programs should be tailored appropriately.