Abstract / Summary
Abstract Purpose The pyramidalis muscle is a variable component of the anterior abdominal wall, and population-specific data from Africa are limited. This study determined the prevalence, laterality, and morphometric characteristics of the pyramidalis muscle and examined associations with age, sex, and chronic disease in a Sudanese surgical cohort. Methods A descriptive cross-sectional study was conducted among 50 adults undergoing lower anterior abdominal wall surgery at Al-Damazin Teaching Hospital, Blue Nile Region, Sudan. Participants were enrolled consecutively. The presence or absence of the pyramidalis muscle, laterality, and morphometric measurements were documented by direct intraoperative inspection using a structured form. Associations with sex and chronic disease were assessed using chi-square tests, and age was compared using an independent-samples t-test. Statistical significance was set at p < 0.05. Results The participants had a mean age of 51.84 ± 21.26 years; 34 (68%) were men and 16 (32%) were women. The pyramidalis muscle was present in 30 (60%) participants and absent bilaterally in 20 (40%). Bilateral presence occurred in 26 (52%) participants, while unilateral presence occurred on the right in 3 (6%) and on the left in 1 (2%). Muscle presence was significantly associated with sex (χ²=7.414, df = 1, p = 0.006), with a higher prevalence in women than men (87.5% vs. 47.1%). Participants with the muscle were younger than those without it (43.70 ± 20.02 vs. 64.05 ± 17.10 years; t=-3.726, df = 48, p = 0.001). No significant association was observed with chronic disease (χ²=2.576, df = 3, p = 0.462). Among participants with measurable muscle, mean length was 6.45 ± 2.76 cm and mean thickness was 1.10 ± 1.08 cm. Conclusion The pyramidalis muscle showed substantial anatomical variability in this Sudanese surgical cohort, with a prevalence of 60% and predominantly bilateral occurrence. Its presence was associated with sex and age but not with chronic disease. The findings provide preliminary population-specific anatomical data and support the need for larger multicentre studies in Sudan and other African populations.