Anatomical Variations of the Superior Mesenteric Artery and Its Clinical and Surgical Implications in Humans

Abstract

Introduction: Superior mesenteric artery (SMA) usually arises from the abdominal aorta, just below the celiac trunk and it supplies the midgut-derived embryonic structures. Anatomical variations in this vessel contribute to problems in the formation and/or absorption of this part of the intestine and its absence has been recognized as the cause of congenital duodenojejunal atresia. Objective: To analyze SMA anatomical variations in humans and the possible associated clinical and surgical implications. Methods: This is a systematic review of papers indexed in PubMed, SciELO, Springerlink, Science Direct, Lilacs, and Latindex databases. The search was performed by two independent reviewers between September and December 2018. Original studies involving SMA variations in humans were included. SMA presence/absence, level, place of origin and its terminal branches were considered. Results: At the end of the search, 18 studies were selected, characterized as for the sample, method to evaluate the anatomical structure and main results. The most common type of variation was when SMA originated from the right hepatic artery (6.13%). Two studies (11.11%) evidenced the inferior mesenteric artery originating from the SMA, whereas other two (11.11%) found the SMA sharing the same origin of the celiac trunk. Conclusion: SMA variations are not uncommon findings and their reports evidenced through the scientific literature demonstrate a great role for the development of important clinical conditions, making knowledge about this subject relevant to surgeons and professionals working in this area.

Classification of the superior mesenteric artery

“…Because the branching pattern of the SMA varies among individuals (Bolintineanu et al, 2019; da Silva et al, 2020; Kurdal et al, 2010; Liang et al, 2017; Wayne et al, 2011), it would be desirable if the anatomy of this area in patients being prepared for surgery were recognized.…”

“…However, no classification of the SMA based on its morphology has been generally accepted to date. SMA branching patterns are still being discovered and their implications for surgical procedures in that anatomical area are significant (da Silva et al, 2020). Previous anatomical studies on cadavers have described SMA variations in the form of case reports in which abnormal arteries were observed.…”

Endoscopic features for early decision to evaluate superior mesenteric artery syndrome in children

“…SMA syndrome is a symptom complex disease caused by extrinsic compression of the third part of the duodenum due to narrowing of the aortomesenteric space (AMS) between the aorta and the SMA [1]. Although the origin and route of the SMA are variable, it arises classically from the aorta at the level of intervertebral discs between vertebral level L1 and L2 [7]. The third part of the duodenum extends from the right side of L3 or L4 to the left side of the aorta and runs horizontally at the level of L3 [8,9].…”

“…Levin argued that the length and location of the narrowing of the duodenum do not match with the location of the AMA [16,17]. Although the anatomic variation and shape of the SMA are quite diverse, Levin predicated that the closed segment of the duodenal images in 29 cases seem to be unlikely related to the SMA through the radiometric analysis from the 35 published articles [7,13,16]. Based on these analysis, Levin introduced the theory of Ochsner functional sphincter dyskinesia as a cause of manifestations of SMAS.…”

Congenitally absent superior mesenteric artery in an asymptomatic adult

“…2 Most of the published literature on congenital absence of the SMA is associated with fetal intestinal atresia. 3 To date, there has been only one published case report of a congenitally absent SMA diagnosed in an adult. 4 Similar to the present case, the authors noted an absent SMA with an enlarged collateral branch of the IMA.…”