Sinkeet Simeon, Mwachaka Philip, Muthoka Johnstone, Saidi Hassan
Department of Human Anatomy, University of Nairobi, P.O. Box 30197, Nairobi 00100, Kenya.
ISRN Anat. 2012 Dec 24;2013:962904. doi: 10.5402/2013/962904. eCollection 2013.
Background. Branching pattern of inferior mesenteric artery (IMA) and pattern of vascular supply to the left colon and rectosigmoid areas, though important during colorectal surgery, display interethnic variations. Further, these regions have notable vascular "weak points" reported to be highly susceptible to ischemic colitis. This study aimed at evaluating the branching pattern of IMA in a black African population. Materials and Methods. Fifty-seven formalin-embalmed cadavers (28 Male, 27 Female) were studied. The length, branching pattern, and diameter of IMA at its origin were recorded. Results. IMA mean length and diameter at origin were 30.57 ± 10.0 mm and 4.10 ± 0.9 mm, respectively. IMA most frequently branched into left colic artery and a common sigmoid trunk in 23 cases while the classical branching pattern was observed in only 7 cases. Colic marginal artery was absent at the splenic flexure and sigmoid colon in 7 and 5 cases, respectively. Arc of Riolan was observed in 9 cases. Conclusion. Branching pattern of IMA shows variations from the previously reported cases which might help account for some of the untoward outcomes observed following colon surgery. An angiographic study to further delineate functionality of the arterial anastomoses in this region is recommended.
背景。肠系膜下动脉（IMA）的分支模式以及左半结肠和直肠乙状结肠区域的血管供应模式，尽管在结直肠手术中很重要，但存在种族间差异。此外，这些区域有明显的血管“薄弱点”，据报道极易发生缺血性结肠炎。本研究旨在评估非洲黑人人群中IMA的分支模式。材料与方法。研究了57具用福尔马林防腐的尸体（28例男性，27例女性）。记录了IMA起始处的长度、分支模式和直径。结果。IMA起始处的平均长度和直径分别为30.57±10.0毫米和4.10±0.9毫米。IMA最常见的分支是在23例中分为左结肠动脉和一条共同的乙状结肠干，而仅在7例中观察到经典的分支模式。分别有7例和5例在脾曲和乙状结肠处无结肠边缘动脉。在9例中观察到Riolan弓。结论。IMA的分支模式与先前报道的病例有所不同，这可能有助于解释结肠手术后观察到的一些不良后果。建议进行血管造影研究以进一步阐明该区域动脉吻合的功能。
