Normal Range of Superior Mesenteric Artery in Young Chinese Population and Its Correlation With Retroperitoneal Adipose Tissue

Normal Range of Superior Mesenteric Artery on Computerized Tomography in Young Chinese Population and Its Correlation With Retroperitoneal Adipose Tissue

In literature, superior mesenteric artery (SMA) angle, also named as aortomesenteric angle (AMA), varies greatly in both adult and children; while the aortomesenteric distance also ranges widely. Both AMA and AMD are influenced by retroperitoneal fat. Decrease of AMA and AMD may lead to the superior mesenteric artery syndrome(SMAS), which is a rare medical condition mainly presenting with duodenum obstruction. To our knowledge, normal range of AMA and AMD in local young Chinese population remain unclear; on the other hand, there have only a few studies exploring the relationship between them. This project proposes to establish the normal range of AMA and AMD in local young Chinese population, and to further investigate how the retroperitoneal adipose tissue correlates with AMA and AMD. The normal range obtained in this proposed study will provide more specific reference value to distinguish abnormal AMA and AMD, and to improve the diagnosis accuracy of SMAS in local population. Moreover, this study will provide deeper insight concerning the impact of retroperitoneal fat on AMA and AMD.

Study Overview

• Status: Completed
• Conditions: Aortomesenteric Angle; Aortomesenteric Distance; Retroperitoneal Adipose Tissue
• Intervention / Treatment: Diagnostic test: computerized tomography

• Study Type: Observational
• Enrollment (Actual): 510

Contacts and Locations

Study Locations

• China
  • Hong Kong, China
    • Department of Radiology， North District Hospital

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 10 years to 35 years (Child, Adult)
• Accepts Healthy Volunteers: N/A
• Genders Eligible for Study: All

• Sampling Method: Probability Sample

Study Population

The investigators will retrospectively recruit individuals from the local population who had undergone abdomen contrast CT scans within hospitals in the New Territories East Cluster (NTEC) of Hong Kong for both emergency and elective purposes in the year 2013-2019. Total sample will comprise two groups: (1) Non-SMAS Group (N=500); and (2) SMAS group (N=10).

Description

Inclusion Criteria:

• With age range of 10-35 years old.
• Chinese ethnicity.
• With abdomen contrast CT.

Exclusion Criteria:

• Any patients with diagnosis of SMAS will be excluded from the Non-SMAS group.
• Patients who had undergone more than one CT scan during the research period.
• Previous retroperitoneal, abdominal surgery.
• Conditions causing significant weight loss, e.g. anorexia nervosa, malabsorption.
• Presence of abdominal masses or pathology that will affect the anatomy of aorta- superior mesenteric artery and the retroperitoneal structures.
• Presence of severe scoliosis and/or history of spinal fixation that may increase incidence of SMA syndrome.
• Presence of free intraperitoneal or retroperitoneal fluid that may affect fat measurement, e.g. following trauma, or ascites.

Study Plan

How is the study designed?

Design Details

• Observational Models: Ecologic or Community
• Time Perspectives: Retrospective

Number of groups / cohorts

2

Cohorts and Interventions

Group / Cohort	Intervention / Treatment
Non-SMAS group; subjects in this group are not clinically diagnosed as superior mesenteric artery syndrome(SMAS).	Diagnostic test: computerized tomography; abdomen contrast computerized tomography performed for both emergency and elective purposes in HK public hospitals.
SMAS group; subjects in this group are clinically diagnosed as superior mesenteric artery syndrome(SMAS).	Diagnostic test: computerized tomography; abdomen contrast computerized tomography performed for both emergency and elective purposes in HK public hospitals.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
aortomesenteric angle (AMA)	aortomesenteric angle in degree measured on sagittal CT image	2 years
aortomesenteric distance (AMD)	aortomesenteric distance in millimeter(mm) on axial CT image	2 years
visceral fat area	visceral fat area in square centimeter(cm2) evaluated by image post-processing software	2 years
subcutaneous fat area	subcutaneous fat area in square centimeter(cm2) evaluated by image post-processing software	2 years
area ratio of visceral fat to subcutaneous fat	area ratio in percentage(%)	2 years

Collaborators and Investigators

• Sponsor: Chinese University of Hong Kong
• Collaborators: North District Hospital
• Investigators: Principal Investigator: Kai Ho Yam, MBChB, Department of Radiology, North District Hospital, Hong Kong

Study record dates

Study Major Dates

• Study Start (Actual): July 25, 2019
• Primary Completion (Actual): June 30, 2021
• Study Completion (Actual): June 30, 2021

Study Registration Dates

• First Submitted: May 2, 2019
• First Submitted That Met QC Criteria: May 2, 2019
• First Posted (Actual): May 3, 2019

Study Record Updates

• Last Update Posted (Actual): May 19, 2022
• Last Update Submitted That Met QC Criteria: May 17, 2022
• Last Verified: May 1, 2022

More Information

Terms related to this study

• Keywords: computerized tomography; aortomesenteric angle; aortomesenteric distance; retroperitoneal adipose tissue; young Chinese population
• Other Study ID Numbers: 2019.310

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: No

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No