Bhatnagar B N S, Sharma C L N, Gupta S N, Mathur M M, Reddy D C S
Department of Surgery, Institute of Medical Sciences, Banaras Hindu University, Varanasi, India.
Clin Anat. 2004 Apr;17(3):236-43. doi: 10.1002/ca.10204.
Although the sigmoid colon is commonly afflicted with disease, studies on its anatomical dimensions are scarce. It is suspected that dimensions of the sigmoid colon change with age. This study documents data on the anatomical measurements of the sigmoid colon in 70 Indian subjects (51 live and 19 cadavers). Seven parameters of sigmoid colon anatomy measured included length and width of the sigmoid colon and mesocolon at specific points. Three mesocolic indices (width to length ratios) were calculated. Comparisons of measurements in the live and cadaver subjects and in the two sexes were made. The relationship of change in parameters with age was assessed. Appropriate statistical methods were used and the differences were considered significant at P < or = 0.05. The study showed wide ranging variations in the values of various measured parameters of the sigmoid colon. Seven patterns of the shape of the sigmoid loop were identified. In the commonest pattern the sigmoid mesocolon was vertically longer than wide (dolichomesocolic), the sigmoid loop having its maximum convexity located just a little proximal to the apex. Patterns where the width of the mesocolon was greater than the vertical length (brachymesocolic) were also observed. The gender analysis showed that the sigmoid mesocolon of the female was brachymesocolic (wider than long), whereas that of the male was dolichomesocolic (longer than wide). This might explain the higher incidence of sigmoid volvulus in the male. This study also showed that the measurements of the sigmoid colon and its mesocolon do not change significantly within the age range of 16-60 years in the two sexes. Also noteworthy is the observation that in the cadaver the sigmoid colon shows considerable shrinkage, particularly of its mesocolon; consequently the data from cadaver subjects, though valuable for anthropometric use, have limitations when used for clinical applications.
尽管乙状结肠常受疾病困扰，但关于其解剖学尺寸的研究却很稀少。人们怀疑乙状结肠的尺寸会随着年龄的增长而变化。本研究记录了70名印度受试者（51名活体和19具尸体）乙状结肠的解剖测量数据。测量的乙状结肠解剖学的七个参数包括乙状结肠和乙状结肠系膜在特定点的长度和宽度。计算了三个系膜指数（宽度与长度比）。对活体和尸体受试者以及两性之间的测量结果进行了比较。评估了参数变化与年龄的关系。使用了适当的统计方法，当P≤0.05时，差异被认为具有统计学意义。研究表明，乙状结肠各种测量参数的值存在广泛差异。确定了乙状结肠袢的七种形态模式。在最常见的模式中，乙状结肠系膜垂直方向上长于宽（长系膜型），乙状结肠袢的最大凸度位于距顶端稍近端处。也观察到系膜宽度大于垂直长度的模式（短系膜型）。性别分析表明，女性的乙状结肠系膜为短系膜型（宽于长），而男性的为长系膜型（长于宽）。这可能解释了男性乙状结肠扭转发病率较高的原因。本研究还表明，在16至60岁的两性年龄范围内，乙状结肠及其系膜的测量值没有显著变化。同样值得注意的是，观察到在尸体中乙状结肠显示出相当程度的收缩，尤其是其系膜；因此，尸体受试者的数据虽然在人体测量学上有价值，但在用于临床应用时存在局限性。
