ARRS 2022 Abstracts


E1311. Criss-Crossed: A Case-Based Multimodality Review of Pediatric Urinary Tract Obstruction Including Extrinsic Compression By Crossing Vessels
  1. Abtin Jafroodifar; SUNY Upstate Medical University
  2. Ryan Thibodeau; SUNY Upstate Medical University
  3. Leen Alkukhun; SUNY Upstate Medical University
  4. Meghan Stanton; SUNY Upstate Medical University
  5. Alyssa Ionno; SUNY Upstate Medical University
  6. Anand Majmudar; SUNY Upstate Medical University
  7. Ravikumar Hanumaiah; SUNY Upstate Medical University
Urinary tract dilatation (UTD) can be related to obstructive and nonobstructive causes. Urinary tract obstruction (UTO) describes the intrinsic or extrinsic hindrance of forward flow in the urinary tract. It is a relatively common clinical problem in the pediatric population, with a reported incidence of approximately 3.1%. UTOcan cause significant morbidity and mortality if not identified in a timely manner and managed accordingly. This exhibit will aim to explore the phenomenon of urinary tract obstruction (UTO) secondary to extrinsic compression by crossing vessels (UTOCV), with a focus on multimodality imaging findings that should be considered in preparation for potential surgical planning. Additionally, we will review the relevant urinary tract anatomy and vasculature as it relates to UTOCV, in addition to more commonly encountered etiologies.

Educational Goals / Teaching Points
First, we will introduce the “crossing vessels” phenomenon by discussing relevant anatomy, including the upper and lower urinary tracts, as well as their relationship with adjacent vasculature. The more common etiologies of UTO will be described, including ureteropelvic junction (UPJ) obstruction, ureterovesical junction (UVJ) obstruction, bladder outlet obstruction, obstructing calculus, ureteroceles, megaureter, vasculitis-related stricture, and posterior urethral valves. Next, we will discuss the epidemiology, etiology, and diagnosis of UTO secondary to extrinsic compression by crossing vessels using cases from our institution, including intraoperative images for correlation. The relevant imaging findings when evaluating cases of UTO secondary to crossing vessels will be described and presented, including finding the origin of the vessels; determining whether a vein or an artery, or both, are present, and tracking vessel path in relationship to the ureter to guide surgical planning; and lastly, providing helpful imaging tips and tricks for radiologists to know when evaluating potential cases of UTO secondary to crossing vessels.

Key Anatomic/Physiologic Issues and Imaging Findings/Techniques
Not surprisingly, radiological evaluation is often the first step in the evaluation for the underlying pathology of UTD, with the first step being ultrasound interrogation due to the lack of radiation – an important concept in the pediatric population. Cross-sectional imaging is key in diagnosis because the offending vessel will be readily identified, the source will be determined (such as an accessory renal artery), and the proper preparations for surgical management can be made.

The concept of UTO is well known; however, radiologsts and trainees may be less comfortable in identifying the true underlying etiology. This includes common entities like ureteroceles or rare phenomena such as crossing vasculature. It is important to determine the reason for UTO to provide clinicians the most relevant information to guide patient management and decision making This is especially true in the presence of crossing-vessels causing obstruction, as the management is surgical intervention.