Position and Length of the Vermiform Appendix: A Study of 400 Cases in Iranian Population

The vermiform appendix, the worm-shaped, closed-ended tube containing a large number of lymphoid follicles, displays variations in its position and macroscopic dimensions according to age, sex, race, and other relevant factors. Variable locations of the appendix may mislead physicians into making an incorrect decision or identification of other diseases. Hence there is a necessity for the study of the different positions of the appendix in patients with appendicitis.

The present study was carried out on 400 bodies (253 males, 147 females) in the autopsy hall of the Forensic Medicine Organization, Tehran province, Iran, from March 2020 to March 2021. The anatomical position of the appendix was recorded during the autopsy. Appendix length and diameter were measured in millimeters using a ruler. The sex of the bodies was recorded based on the observed phenotype, and their age was verified based on their identity document. The data obtained were analyzed using SPSS software version 20.

The pelvic appendix was found to be the most common (29.7%) in both men and women, followed by paracecal in (21.8%), prececal (19.5%), retrocecal (12.5%), subcecal (8%), pre-ileal (6%), and post-ileal (2.5%). The association between sex and appendiceal length was statistically significant, with women having longer appendices than men (85.1±13.8 mm vs. 81.9±13.4 mm, P=0.028). Also, the appendiceal diameter was significantly larger in women than in men (3.81±0.7 mm vs. 3.45±0.66 mm, P=0.017). There was a significant association between sex and position of the appendix, with paracecal position being more prevalent in men and retrocecal in women (P=0.04). The mesoappendix was complete in all cases.

In our study, the commonest position of the appendix was pelvic. The maximal length and diameter of the appendix were 85.1±13.8 and 3.81±0.7 mm, respectively. This shows variations with related reports from other populations. Knowledge of these variations is essential for early detection, treatment, and fewer complications for related diseases.