Sonographic Detection of Renal Artery Dissection Secondary to Stanford Type a Aortic Dissection: Case Report

Abstract

Introduction

Aortic dissections (AD) are a result of the development of a focal intimal tear, most likely caused by medial degeneration. Medial changes occur as a consequence of hemodynamics and other predisposing factors. This condition most often affects males between 40 and 70 years of age, with the history or presence of hypertension being the most consistent clinical finding. The creation of the intimal tear allows pulsatile blood to enter and propagate through the aortic media, thus forming a false channel and predisposing the patient to possible end-organ complications. Duplex ultrasound demonstrates dissection as an undulating membrane, containing asymmetrical blood flow.

Aortic dissections are classified by location and extent of the intimal tear. Stanford type A (DeBakey type I) involves the ascending aorta. These dissections are life-threatening, and patients usually require emergent surgical reconstruction.

Case Report

A 33-year-old male with a past medical history significant for hypertension since 15 years of age was transferred from an outside hospital and presented with a greater than 5 cm ascending aortic aneurysm and a Stanford type A aortic dissection. A transesophageal echocardiogram (TEE) was performed and confirmed a type I dissection that showed extension to just below the level of the diaphragm. He was taken for emergent aortic repair. On postoperative day 1, the patient developed acute renal insufficiency. Duplex ultrasound was performed to assess renal artery flow, revealing propagation of dissection into bilateral proximal renal arteries and significant stenosis at the origin of the right renal artery. The patient underwent right renal artery percutaneous transluminal angioplasty and stent placement to restore blood flow to the right kidney.

Conclusions

This case demonstrates and identifies the etiology, pathology, and classifications of aortic dissection as it relates to this case. Duplex ultrasound was a safe, reliable, and sensitive tool for the evaluation of end-organ complications associated with dissection.