Course and Variations in Branches of Inferior Mesenteric Artery

Background : The mesenteric blood supply is acombination of rich collateral networks. There are frequentanatomical variants encountered and these variations aresometimes involved in pathologies. Treatment of whichrequires a better understanding of the variations in the normalanatomy of the inferior mesenteric artery.Methods : The present study was carried out in theDepartment of Anatomy, Prathima Institute of MedicalSciences, Karimnagar. A total of n=50 specimens, with n=17adult males and n=2 adult female cadavers and fetuses of whichn=26 were term and n=2, was preterm. Female fetuses n=2 ofterm and n=1 preterm were included in the study.Results : The following variations were observed inthe present study of course and variations in the branches ofthe inferior mesenteric artery and are grouped into three types.Type I: In this type middle colic artery is arising from the inferiormesenteric artery instead of the superior mesenteric artery.It is a rare-variations and observed in a female fetus.Type-II: Four Sigmoidal arteries are arising from an inferiormesenteric artery, after the origin of the left colic artery. Thistype is observed in a male fetus.Type-III: Three Sigmoidal arteries are originated from theinferior mesenteric artery. This type was observed in a maleadult and a male fetus.Conclusion: Out of the 50 cases included in the studywe found type 1 variation of IMA in 2% of cases, type 2 variationwas found in 2% samples, and type 3 variation was found in4% of samples. Based on the variations radiologists andSurgeons should be aware of possible consequences whendoing colectomy, right hemicolectomy, left hemicolectomy,sigmoidectomy, en-bloc resection of the head of the pancreas,aneurysm, and chronic bowel ischemia. The present study isalso useful for reconstructive surgeries in inferior mesentericarteries in the case of ischemia.