Morphology and arterial supply of the pyramidalis muscle in an Australian female population using computed tomography angiography

Introduction

The structure and function of the human anterolateral abdominal wall have been thoroughly described. However, there has been limited anatomical study of the pyramidalis muscle and its arterial supply. The aim of this study was to analyse the patterns of arterial supply to the pyramidalis in a female population.

Methods

A retrospective study of 32 computed tomography angiography scans of the abdominal wall of adult women was performed to assess the prevalence (bilateral or unilateral presence, or absence), morphology (medial border height, base width and thickness) of pyramidalis and patterns of arterial supply.

Results

Pyramidalis prevalence was bilateral in 75% of computed tomography angiography studies (24/32), unilateral in 6.3% (2/32) and absent in 18.8% (6/32). Of the five patterns of pyramidalis arterial supply observed and described in detail, the most frequent (68%, 34/50 of cases) originated from an exclusive muscular branch of the inferior epigastric artery. Origin from the pubic branch of the inferior epigastric artery was seen in 4% (2/50). There was a single case (2%, 1/50) of artery origin from a variant obturator artery, a common trunk with the pubic branch from the inferior epigastric artery, and from the muscular branch to rectus abdominis. The artery could not be defined in 22% (11/50).

Conclusion

In this computed tomography angiography study of women, five patterns of Pyramidalis arterial supply were identified. In the majority of cases, the pyramidalis derived its arterial supply from an exclusive, isolated muscular branch of the inferior epigastric artery.