Variations in vascular anatomy and unilateral adrenal agenesis in a female cadaver with situs inversus totalis.

Abstract

Situs inversus totalis is mirror transposition of thoracic and abdominal organs. Very few reports have been published on anatomic dissections of cadavers with this condition. This work describes a case of situs inversus totalis identified during the anatomical dissection of a 91-year-old woman. Thoracic and abdominal viscera were inverted, but otherwise normal. The aorta originated from the right ventricle, which exhibited characteristics of the systemic ventricle. The pulmonary artery originated from the left ventricle, which had a tricuspid valve, three papillary muscles, thick trabeculae, a supraventricular crest, and septomarginal trabecula. The atrial situs was concordant with ventricular morphology. Lungs and paranasal sinuses were not suggestive of Kartagener's syndrome. Only the right adrenal gland was present, and variations in vascular anatomy were observed. The latter included: the celiac trunk branching into a phrenic artery, the splenic artery and a right gastric artery; the common hepatic artery originating from the superior mesenteric artery; and, on the left side, two inferior thyroid arteries, both originating from thyrocervical trunk. The occurrence of a double inferior thyroid artery and agenesis of adrenal gland was never communicated in situs inversus. Embryonic origin of celiac trunk and superior mesenteric artery variations could be explained by the separation at higher levels of the longitudinal anastomoses formed between the four roots of omphalomesenteric artery. It can be hypothesized that this phenomenon could occur more frequently in situs inversus than in situs solitus. However, the number of cases investigated in such detail is too small to draw firm conclusions.