|Year : 2016 | Volume
| Issue : 2 | Page : 98-100
Horizontally placed sigmoid mesocolon and a redundant loop of sigmoid colon filling the pelvic cavity
Satheesha B Nayak, Ravindra S Swamy, Abhinitha Padavinangady, Naveen Kumar, Ashwini P Aithal, Surekha D Shetty
Department of Anatomy, Melaka Manipal Medical College (Manipal Campus), International Centre for Health Sciences, Manipal University, Manipal, Karnataka, India
|Date of Web Publication||12-Jul-2016|
Ravindra S Swamy
Department of Anatomy, Melaka Manipal Medical College (Manipal Campus), International Centre for Health Sciences, Manipal University, Manipal - 576 104, Karnataka
The sigmoid colon, when longer than its usual length is known as dolichosigmoid or redundant sigmoid colon. In the present case, the redundant sigmoid colon was about 20” long, and its distal part was “M” shaped. Its mesocolon was having a short 3” root attached to first sacral vertebral segment horizontally with the absence of its usual right and left limbs. The extra length of the sigmoid colon and atypical attachment of its mesocolon may favor the volvulus formation. Such variation may also cause constipation and pose difficulty in radiological diagnosis and instrumentation, making it clinically and surgically important.
Keywords: Redundant sigmoid colon, sigmoid mesocolon, volvulus
|How to cite this article:|
Nayak SB, Swamy RS, Padavinangady A, Kumar N, Aithal AP, Shetty SD. Horizontally placed sigmoid mesocolon and a redundant loop of sigmoid colon filling the pelvic cavity. Sahel Med J 2016;19:98-100
|How to cite this URL:|
Nayak SB, Swamy RS, Padavinangady A, Kumar N, Aithal AP, Shetty SD. Horizontally placed sigmoid mesocolon and a redundant loop of sigmoid colon filling the pelvic cavity. Sahel Med J [serial online] 2016 [cited 2021 Jan 18];19:98-100. Available from: https://www.smjonline.org/text.asp?2016/19/2/98/186039
| Introduction|| |
Redundant sigmoid colon or dolichosigmoid colon means a longer sigmoid colon than normal. Longer sigmoid colon with the narrow root of sigmoid mesocolon (SMC) can be a cause of sigmoid volvulus, chronic constipation, colicky pain, and functional disturbances in the neighboring structures. Variant position and length of the sigmoid colon may make radiological diagnosis and instrumentation difficult making such variations notable. Normally, the sigmoid colon is about 16” in length, begins in front of the left iliacus muscle. First, it descends in contact with the left pelvic wall and then passes between the rectum and the urinary bladder finally ending in the rectum at the level of the third sacral vertebra. The present case had a double looped (“M” shaped) redundant sigmoid colon with the short root of SMC. This can increase the chances of sigmoid volvulus and constipation. Hence, we report this variation and discuss its clinical implications.
| Case Report|| |
During our dissection classes for medical undergraduates, we found a variation related to sigmoid colon and its mesocolon in an adult male cadaver approximately aged 70 years. The sigmoid colon was about 20” long which was about 4” more than normal. Its proximal part (in the left iliac fossa) was retroperitoneal. Its distal part (in the pelvic cavity) formed a redundant loop, which was “M” shaped and filled the pelvic cavity completely. The distal part was broader than the proximal part. The SMC did not have right and left limbs as described in the textbooks of anatomy. It was attached horizontally to the anterior surface of the first sacral vertebral segment. Its root was about 3” long and free border along the sigmoid colon was about 20” long. Due to this, the SMC was fan shaped like the mesentery of the small intestine (SI). The variations are shown in [Figure 1] and [Figure 2].
|Figure 1: Lower abdominal and pelvic viscera as seen from above. (DC: Descending colon; LIF: Left iliac fossa; RPSC: Retroperitoneal part of sigmoid colon; PPSC: Pelvic part of sigmoid colon; SMC: Sigmoid mesocolon; SP: Sacral promontory)|
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|Figure 2: Closer view of lower abdominal and pelvic viscera as seen from above. (RPSC: Retroperitoneal part of sigmoid colon; PPSC: Pelvic part of sigmoid colon; SMC: Sigmoid mesocolon; SI: Small intestine; AAW: Anterior abdominal wall)|
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| Discussion|| |
The sigmoid colon is known to possess redundant loops. Sigmoid colon also might vary in length or may be right-sided. Even though variant positions of the sigmoid colon have been reported in the past,,, the present case having a particular “M” shaped redundant sigmoid colon is a rarity. The sigmoid colon in the present case had a fan shaped mesocolon with short root just like the mesentery of SI along with the absence of its usual right and left limbs. This condition may favor volvulus formation. Sigmoid redundancy is a developmental anomaly that occurs due to malrotation of the primitive gut during fetal life. It occupies the lower abdominal cavity and pelvic region. Sigmoid redundancy may be asymptomatic, but there are chances of functional and clinical consequences. Saunders conducted a study on intraoperative measurement of colonic anatomy which helps to define anatomical variations that may affect the colonoscopy. In abdominal radiography, gas in the sigmoid loop in its right side can be mistaken for gas in caecum and such cases may cause difficulty during surgical intervention. A study conducted by Madiba and Haffajee comparing sigmoid colon among African, Indians, and white population in Africa reveals longer length and height of the sigmoid colon and a narrower mesocolon root in Africans. It also stated the high incidence of the redundant sigmoid colon with the long narrow type and suprapelvic position in Africans, which may explain geographical and racial differences in sigmoid volvulus. Thus, a regional study of the sigmoid colon is also necessary for determining the prevalence of such variation, so as to create awareness in the medical community regarding this anomaly.
| Conclusion|| |
“M” shape of sigmoid colon with narrow root mesocolon as in present case may facilitate the formation of sigmoid volvulus, or lead to chronic constipation and functional disturbances in the neighboring structures as evident from above reports, making the “M” shaped redundant sigmoid colon clinically important. It may also cause difficulties in sigmoidoscopy procedure and in the interpretation of various radiological images of the pelvic region. Large sigmoid colon monopoly in the pelvic cavity may disturb normal functioning of urinary and reproductive organs of the pelvis too. Hence, the radiologists, surgeons, and clinicians, in general, have to be aware of this anomaly.
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Conflicts of interest
There are no conflicts of interest.
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[Figure 1], [Figure 2]