Intestinal volvulus: a new concept

The role of sigmoid colon anatomic dimensions in the development of sigmoid volvulus, North-Western Ethiopia

Introduction

Sigmoid colon anatomic dimensions have been studied to have roles in the occurrence of sigmoid volvulus; however, these studies are few in number and failed to control the confounding effect of acute sigmoid obstruction on the anatomic dimensions. The main objective of this study was to assess the role of sigmoid colon anatomic dimensions in the development of sigmoid volvulus controlling the effect of acute sigmoid obstruction on the anatomic dimensions.

Materials and methods

The study was carried out from Dec, 2019 to April, 2021 at Tibebe Ghion Specialized Hospital and Felege Hiwot Comprehensive Specialized Hospital, two referral hospitals in Bahir Dar city, North-Western Ethiopia to compare sigmoid anatomic dimensions among three independent groups of participants: patients with no history of sigmoid volvulus (I), those for whom elective surgery was done after non-surgical detorsion of sigmoid volvulus (II), and patients for whom emergency surgery was done for sigmoid volvulus (III). The anatomic dimensions were compared using fixed effects one-way ANOVA or Kruskal-Wallis H test at p-value ≤ .05 (two-sided) and Tukey method or Dunn-Bonferroni’s test was used for post-hoc comparisons.

Results

A total of 66 consecutive eligible patients (22 for each of the three groups) were included and analyzed in the study. The means of anatomic dimensions (in cm) for groups (I, II, III) were: sigmoid colon length-SCL (35.91, 71.07, 80.86), meso-sigmoid height-MSH (17.11, 26.52, 28.86), meso-sigmoid maximal width-MSMW (9.70, 14.89,16.80), and meso-sigmoid root width-MSRW (8.34, 7.48, 8.11). SCL, MSH, MSMW, MSH/MSRW, and MSMW/MSRW were found to be statistically significantly different in patients with sigmoid volvulus. MSRW and MSH/MSMW were not different between the study groups.

Conclusion

A long sigmoid colon with long and wide mesentery, but with a constant base is highly likely to predispose individuals to sigmoid volvulus.

Prediction of the Clinical Outcomes of Sigmoid Volvulus by Abdominal X-Ray: AXIS Classification System

Aim

Early diagnosis and evaluation of the severity of sigmoid volvulus are necessary for management and early intervention. We developed a new predictive classification system for sigmoid volvulus based on X-ray findings.

Methods

We retrospectively analyzed 66 patients diagnosed with sigmoid volvulus using the electronic medical records at the Osaki Citizen's Hospital and the University of Tokyo Hospital from 2008–2015. We classified patients according to the coffee-bean sign mesenteric axis on X-ray (AXIS classification: group A, 0–90°; group B, 90–135°; and group C, >135°). We examined the association between AXIS classification and severe sigmoid volvulus, intestinal necrosis, need for surgery, 30-day mortality, and length of stay using the Cochran–Armitage trend test.

Results

In total, 66 patients were analyzed. They had a mean age of 76.9 years, and 47 (71.0%) were male. They were classified into three groups according to the AXIS classification system (group A, 40 patients; group B, 23 patients; and group C, 3 patients). Group C had a significantly higher frequency of severe sigmoid volvulus (100%) compared to group B (30%) and group A (15%). AXIS classification was significantly associated with the severity of sigmoid volvulus (p = 0.003), necrosis (p = 0.004), and need for surgery (p = 0.001), but not with the 30-day mortality or the length of stay.

Conclusions

We developed the AXIS classification system to predict the severity of sigmoid volvulus. This new classification system may facilitate triage and therapeutic decision-making for sigmoid volvulus patients.

Article Commentary: The Twisted Colon: A Review of Sigmoid Volvulus

Sigmoid volvulus (SV) is the third leading cause of colon obstruction in adults. In infants and children, it is exceedingly rare with only sporadic cases reported so far. SVs from secondary causes, with congenital megacolon being the most important, are nevertheless more common in young people. The etiology of this disorder is not completely understood. It is known to occur in the setting of redundant sigmoid loop, which rotates around its narrow and elongated mesentery. Although the latter occurs in the setting of constipation, a congenitally elongated colon, and other predisposing factors, there is no consensus on the precipitating factor leading to SV formation. The symptoms are suggestive of small bowel obstruction, but the presentations can be acute or indolent. Plain abdominal radiography is used to diagnose SV in most cases with computed tomography scan or magnetic resonance imaging as the confirmatory tests when necessary. After it has been untwisted, the definitive and standard therapy for SV is sigmoid resection and primary anastomosis. The nonresective alternatives have also been widely used with mixed success, but a large, randomized controlled trial is needed to compare their efficacy with resection and primary anastomosis. Laparoscopic surgery in SV management is unwarranted and costly. Complications of SV include hemorrhagic infarction, perforation, septic shock, and death. The mortality data from SV vary, but the latest literature cites an overall range of 14 to 45 per cent.

Intussusception, volvulus and malrotation

A case of ileocolic intussusception, associated with mid-gut volvulus and malrotation with bowel necrosis is reported. There is evidence to suggest that the intussusception preceded the volvulus.