Case Report
Copyright ©The Author(s) 2024. Published by Baishideng Publishing Group Inc. All rights reserved.
World J Gastroenterol. Feb 7, 2024; 30(5): 499-508
Published online Feb 7, 2024. doi: 10.3748/wjg.v30.i5.499
Dynamic ultrasonography for optimizing treatment position in superior mesenteric artery syndrome: Two case reports and review of literature
Nobuaki Hasegawa, Akihiko Oka, Muyiwa Awoniyi, Yuri Yoshida, Hiroshi Tobita, Norihisa Ishimura, Shunji Ishihara
Nobuaki Hasegawa, Akihiko Oka, Norihisa Ishimura, Shunji Ishihara, Department of Internal Medicine II, Shimane University Faculty of Medicine, Izumo 693-8501, Shimane, Japan
Muyiwa Awoniyi, Department of Gastroenterology, Hepatology and Nutrition, Digestive Disease and Surgery Institute, Hepatology Section, Cleveland Clinic, Cleveland, OH 44195, United States
Yuri Yoshida, Clinical Laboratory Division, Shimane University Hospital, Izumo 693-8501, Shimane, Japan
Hiroshi Tobita, Division of Hepatology, Shimane University Hospital, Izumo 693-8501, Japan
Author contributions: Hasegawa N, Oka A, and Awoniyi M contributed to drafting of manuscript; Hasegawa N, Oka A, and Yoshida Y contributed to assessment of ultrasonography; Tobita H, Ishimura N, and Ishihara S contributed to supervisor of study; All the authors solely contributed to this paper.
Informed consent statement: This publication of case reports was approved by the Shimane University Hospital review board (approval No. 6612) in adherence to the Helsinki Declaration. Each patient provided informed consent for publication.
Conflict-of-interest statement: All the authors report no relevant conflicts of interest for this article.
CARE Checklist (2016) statement: The authors have read CARE Checklist (2016), and the manuscript was prepared and revised according to CARE Checklist (2016).
Open-Access: This article is an open-access article that was selected by an in-house editor and fully peer-reviewed by external reviewers. It is distributed in accordance with the Creative Commons Attribution NonCommercial (CC BY-NC 4.0) license, which permits others to distribute, remix, adapt, build upon this work non-commercially, and license their derivative works on different terms, provided the original work is properly cited and the use is non-commercial. See:
Corresponding author: Akihiko Oka, MD, PhD, Assistant Professor, Department of Internal Medicine II, Shimane University Faculty of Medicine, 89-1, Izumo 693-8501, Shimane, Japan.
Received: October 2, 2023
Peer-review started: October 2, 2023
First decision: November 24, 2023
Revised: December 11, 2023
Accepted: January 12, 2024
Article in press: January 12, 2024
Published online: February 7, 2024

Superior mesenteric artery (SMA) syndrome is a rare cause of duodenal obstruction by extrinsic compression between the SMA and the aorta (SMA-Ao). Although the left lateral recumbent position is considered effective in the treatment of SMA syndrome, individual variations in the optimal patient position have been noted. In this report, we present two elderly cases of SMA syndrome that exhibited rapid recovery due to ultrasonographic dynamic evaluation of the optimal position for each patient.


Case 1: A 90-year-old man with nausea and vomiting. Following diagnosis of SMA syndrome by computed tomography (CT), ultrasonography (US) revealed the SMA-Ao distance in the supine position (4 mm), which slightly improved in the lateral position (5.7–7.0 mm) without the passage of duodenal contents. However, in the sitting position, the SMA-Ao distance was increased to 15 mm accompanied by improved content passage. Additionally, US indicated enhanced passage upon abdominal massage on the right side. By day 2, the patient could eat comfortably with the optimal position and massage. Case 2: An 87-year-old woman with vomiting. After the diagnosis of SMA syndrome and aspiration pneumonia by CT, dynamic US confirmed the optimal position (SMA-Ao distance was improved to 7 mm in forward-bent position, whereas it remained at 5 mm in the supine position). By day 7 when her pneumonia recovered, she could eat with the optimal position.


The optimal position for SMA syndrome varies among individuals. Dynamic US appears to be a valuable tool in improving patient outcomes.

Keywords: Superior mesenteric artery syndrome, Wilkie’s syndrome, Cast syndrome, Aorto-mesenteric compass syndrome, Ultrasonography, Case report

Core tip: Superior mesenteric artery (SMA) syndrome is a rare cause of duodenal obstruction by extrinsic compression between the SMA and aorta. While the left lateral recumbent position has traditionally been recommended as conservative therapy for facilitating duodenal passage, recent studies have highlighted variations in the optimal position among patients. Here, we present two cases of SMA syndrome where rapid recovery was achieved through ultrasonographic dynamic evaluation of the individualized optimal positions. This pioneering report includes valuable images and a video of dynamic ultrasonography, contributing to improved prognosis by averting potentially life-threatening complications such as shock, pancreatitis, perforation, and hypokalemia.