Morphological characteristics of appendix vermiformis in human: a pilot study to establish regional norms with special interest on its position

Abstract

INTRODUCTION: Regional variations of morphology of the appendix vermiformis have been observed, especially with reference to its position, but due to the scarcity of scientific studies on its regional anatomy, achieving norms for its morphology is difficult. OBJECTIVE: To describe morphological characteristics of human cadaveric appendices. Design, setting and methods: A descriptive, prospective, cross sectional study was carried out among 30 patients who underwent laparoscopic appendicectomy in Colombo North Teaching Hospital, and 60 dissected cadavers in Departments of Anatomy in the Medical Faculties of Ragama and Sri Jayewardenepura. Results: The mean length of appendix was 65mm, ranging from 35mm to 110mm. 96.6% (58/60) of appendices were attached to the postero-medial surface and 3.4%(2/60) to the apex of the cecum. In all cadavers, the shape of the cecum was found to be ampullary. The mean outer diameter of appendices were 5.2mm, ranging from 3mm to 10mm. 41.6% (22/90) were retrocecal, 6.6% (6/90) pelvic (subcecal and promonteric 3.3% each), and 51.6% (46/90) were ileal (consisting 30% (27/90) post ileal and 21.6% (19/90) pre-ileal). 96.6% (58/60) of appendices were supplied by the inferior division of ileo-cecal artery, and 1.6% (1/60) by the posterior cecal artery. The mean distance between the opening of the appendix to cecum and to the opening of ileo cecal opening was 2i.2mm (range 13mm to 24mm). The mean length of the appendicular artery was 35mm (range 25mm to 40mm). CONCLUSION: Regional variations of morphological characteristics of appendix are numerous, especially with regard to its position. Therefore to establish norms for a population, further extensive studies are needed.