Abdominal complications due to collapse of a large mesenteric hematoma after rupture of a right colic artery aneurysm: a case report

Background Non-traumatic mesenteric hematomas are usually well controlled, with no resulting symptoms. Herein, we report a case in which collapse of a large mesenteric hematoma, after rupture of a right colic artery aneurysm, caused small bowel obstruction and rapid absorption of the hematoma contributed to cholestasis. Case presentation A-44-year-old man presented with a sudden onset of severe right lower abdominal pain. Computed tomography (CT) revealed rupture of a right colic artery aneurysm and intra-abdominal bleeding. After embolization of the right colic artery aneurysm, a large mesenteric hematoma remained. As the patient had no symptoms, we elected to pursue conservative treatment. However, on day 16 post-onset, he developed right lower abdominal pain. On CT imaging, partial collapse of the wall of the residual mesenteric hematoma was observed, with visible leakage from the hematoma into the abdominal cavity, resulting in small bowel obstruction and cholestasis. Symptoms did not improve with conservative treatment, and we proceeded to surgical treatment on day 32 after onset. Intra-operatively, adhesions between the small bowel and the abdominal wall were identified and caused the small bowel obstruction. We proceeded with removing these adhesions and as much of the hematoma as possible. Although the small bowel obstruction improved after surgery, cholecystitis developed, and percutaneous transhepatic gallbladder aspiration was performed on day 45. The patient was discharged on day 70. Conclusions Collapse of a mesenteric hematoma can cause small bowel obstruction. Rapid absorption of the hematoma due to the collapse might contribute to cholestasis. A large abdominal hematoma might be a risk factor for failure of conservative treatment, and surgery might be required due to abdominal complications.

The New Concept of Physiological “Riolan’s Arch” and the Reconstruction Mechanism of Pathological Riolan’s Arch After High Ligation of the Inferior Mesenteric Artery by CT Angiography-Based Small Vessel Imaging

BackgroundDue to the complexity of anatomical relationship between superior mesenteric artery (SMA) and left colic artery (LCA), there is no unified anatomical concept of “Riolan’s arch.” There is no consensus as to tie off the inferior mesenteric artery (IMA) at its origin or just below the origin of the left colic artery during radical surgery of sigmoid colon and rectal cancers. The aim of the study is to investigate the anatomy of shortcut anastomotic branches (adjacent branches) of SMA at splenic flexure and to explore how the shortcut pathway (Riolan’s arch) was formed, as the compensation of anastomotic branches between MCA and LCA under pathological conditions and the reconstruction and the mechanism of pathological Riolan’s arch after high ligation of the inferior mesenteric artery.MethodsBetween January 2018 and May 2020, patients with colorectal cancer who underwent CTA before surgery were enrolled in the study. The anatomy of shortcut anastomotic branch of SMA and LCA was investigated by volume rendering technique (VR) and maximum-intensity projection (MIP). GE’s small vessel extraction technology (selected VR) was used to directly display these shortcut anastomotic branches on a map and to establish their three-dimensional anatomical classification. Then, we used the axonometric drawing to make the model more exact. Next, combining with some cases of pathological Riolan’s arch and basing on hydrodynamic principle, we speculate the mechanism of collateral circulation. Finally, based on the retrospective study of high ligation cases and combined principles of fluid mechanics, we show how these shortcut anastomotic branches evolved into Riolan’s arch.ResultsWe report the classification of the ascending branch of LCA (which approaches the splenic flexure) and the left branch of MCA, display these shortcut anastomotic branches on a map, and establish their three-dimensional anatomical classification. We found that Riolan’s arch is a shortcut pathway for the compensation of anastomotic branches, between MCA and LCA under pathological conditions, and that the formation mechanism of shortcut path accords with the principle of hydrodynamics.ConclusionsOur results show the mechanism of pathological Riolan’s arch formation and provide new anatomic thinking for the battle between high and low ligation of IMA in colorectal cancer surgery.

Anatomical Study of Variations in the Branches of Superior Mesenteric Artery – A Study from a Teaching Hospital in Chennai, India

BACKGROUND Superior Mesenteric Artery (SMA) is one of the anterior branches of the abdominal aorta. It originates from abdominal aorta at the level of lower border of first lumbar vertebra, one centimeter below the coeliac trunk. It gives the first branch inferior pancreaticoduodenal artery (IPDA), The colic branches arise from concave right side of the superior mesenteric artery, these are middle colic artery (MCA), right colic artery (RCA), ileo colic artery (ICA). Jejunal and ileal branches arise from left side of the SMA. Superior mesenteric artery supplies derivatives of midgut. Knowledge of branching pattern of the SMA is clinically important to gastroenterologists operating on gut and neighboring structures like pancreas, duodenum, and liver. We wanted to study the variations in the branches of superior mesenteric artery. METHODS This is a descriptive study conducted on 50 adult embalmed human cadavers by conventional dissection method, the findings were noted and tabulated. RESULTS Present study shows that inferior pancreatic duodenal artery orginated from SMA in 47 (94 %) specimens. IPDA was absent in 3 (6 %) specimens. Middle colic artery was found to arise from SMA in 48 (94 %) and MCA was absent in 2 (4 %) specimens. Right colic artery was found to arise from SMA in 47 (94 %) specimens and it was absent in 3 (6 %) specimens. Ileo-colic artery was found to arise from SMA in all 50 (100 %) specimens. CONCLUSIONS Awareness of these complex variations may prevent devastating complications during colonic surgeries. Variations in the branching pattern of superior mesenteric artery is essential for surgeons operating on derivatives of midgut, liver, pancreas. KEY WORDS Branches, Colic, Superior Mesenteric Artery, Variations

Course and Variations in Branches of Inferior Mesenteric Artery

Background : The mesenteric blood supply is a combination of rich collateral networks. There are frequent anatomical variants encountered and these variations are sometimes involved in pathologies. Treatment of which requires a better understanding of the variations in the normal anatomy of the inferior mesenteric artery. Methods : The present study was carried out in the Department of Anatomy, Prathima Institute of Medical Sciences, Karimnagar. A total of n=50 specimens, with n=17 adult males and n=2 adult female cadavers and fetuses of which n=26 were term and n=2, was preterm. Female fetuses n=2 of term and n=1 preterm were included in the study. Results : The following variations were observed in the present study of course and variations in the branches of the inferior mesenteric artery and are grouped into three types. Type I: In this type middle colic artery is arising from the inferior mesenteric 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 inferior mesenteric artery, after the origin of the left colic artery. This type is observed in a male fetus. Type-III: Three Sigmoidal arteries are originated from the inferior mesenteric artery. This type was observed in a male adult and a male fetus. Conclusion: Out of the 50 cases included in the study we found type 1 variation of IMA in 2% of cases, type 2 variation was found in 2% samples, and type 3 variation was found in 4% of samples. Based on the variations radiologists and Surgeons should be aware of possible consequences when doing colectomy, right hemicolectomy, left hemicolectomy, sigmoidectomy, en-bloc resection of the head of the pancreas, aneurysm, and chronic bowel ischemia. The present study is also useful for reconstructive surgeries in inferior mesenteric arteries in the case of ischemia.