Sigmoid Volvulus and Ileosigmoid Knotting: An Update

Sigmoid volvulus and ileosigmoid knotting are uncommon intestinal obstructions, which generally affect adult males. The etiology is multifactorial. Volvulus triad including abdominal pain/tenderness, distention, and obstipation/constipation is the common clinical presentation. Although x-ray radiography helps with diagnosis, the current diagnostic procedure is computed tomography or magnetic resonance imaging in addition to flexible endoscopy in sigmoid volvulus. Endoscopic decompression is the primary treatment except for the presence of bowel gangrene and peritonitis in sigmoid volvulus, while such conditions and also ileosigmoid knotting require emergency surgery. The prognosis is relatively poor under these adverse circumstances and in ileosigmoid knotting.


Introduction
6][7] However, both SV and ISK are relatively common in Eastern Anatolia. 8,9As a result of which, in our 56-year experience (from June 1966 to July 2022), the 1051-case SV series is the largest and the 80-case ISK series is the third largest monocenter patient serials in the world. 10,11In this review, based on the present comprehensive experience of Atatürk University Faculty of Medicine, the biggest health center of the region, an up-to-date information was offered in company with worldwide literature.
Sigmoid volvulus frequently affects adults in the 4th-8th decades and the disease is more common in males with a ratio of 2/1 to 10/1, 1,2,4,25,27 while ISK is generally seen in 3rd-5th decades with a male/female ratio of 2/1 to 6/1. 18

Etiology
1][32][33][34] In ISK, additionally, a hypermobile terminal ileum is effective. 6,35Dolichosigmoid is rarely congenital as seen in childhood cases, whereas it is generally acquired. 2,3637,38 Similarly, dolichosigmoid is more common in males; additionally, a relatively smaller pelvic inlet prevents derotation of the sigmoid colon causing both SV and ISK. 39[42][43] Due to undigested fiber, high-fiber and highcarbohydrate diets cause bulky stool, colonic fecal loading, and distention. 2,26,44Chronic constipation and some laxatives or enemas also lead to colonic distention. 2,26,45Living at high altitude induces the expansion of intracolonic gases (carbon dioxide, methane, and hydrogen) due to lower atmospheric pressure, which also results in the same problem. 44,46,47A similar result is seen in bad defecation habits as demonstrated in mentally retarded persons. 14,45,48

Main Points
• Although sigmoid volvulus (SV) and ileosigmoid knotting (ISK) are uncommon intestinal obstruction forms, they have relatively wide geographic ranges.For this reason, some practitioners and some patients may encounter these nightmares someday.
• The current diagnostic procedure is computed tomography or magnetic resonance imaging in both diseases and additionally endoscopy in SV.
• Current management is flexible endoscopic decompression in SV, while complicated patients and those with ISK require emergency surgery.
• Despite modern diagnostic and therapeutic methods, the prognoses are still relatively poor, particularly in ISK.Some neurologic entities such as Parkinson' s disease and Alzheimer' s disease trigger the same pathology by the way of neuronal destruction or used drugs. 1,44,49,50Various diseases including Hirschsprung' s disease or Chagas' disease look like previously mentioned entities from the viewpoint of intestinal activity. 2,44,51In the end, chronic distention and increased intraluminal pressure worsen the elastogenesis of the colonic wall, and over time, dolichosigmoid occurs, which increases SV and ISK risks. 2,26,47thophysiology The sigmoid colon rotates from time to time and rotations less than 180° are considered to be physiological, which generally result in spontaneous derotation. 1,2,52,53However, untwisting requires much more force and a wider intraabdominal volume and it may be impossible due to the weariness of the sigmoid colon in addition to its enlargement arising from gas generation, which results in entrapment of the sigmoid colon and volvulus. 52,54Excessive torsions more than 180° frequently cause luminal obstruction, while vascular circulation is blocked when it passes 360°. 1,2,52,53though dolichosigmoid is the principal condition in the development of SV and ISK, it does not occur in all risky people and all the time, because a triggering factor is generally needed. 35,52[57][58][59][60][61] In SV, due to the obstruction of the passage, the sigmoid colon enlarges, and additionally, fluid and electrolyte escape into the lumen.In ISK, this process is quicker and waxier due to the double-loop obstruction.Following the vascular blockage, ischemic injury occurs in the mucosa and it affects all layers in time.Bacterial translocation and absorption of toxic materials invoke shock.Increased intraabdominal volume pressure results in abdominal compartment syndrome. 2,16,18,20,24

Diagnosis
There is no pathognomonic routine laboratory test for SV and ISK.In SV, although various signs including omega or horseshoe, coffee bean, or bird beak signs have been described, plain abdominal x-ray radiographs are diagnostic in 57%-90% of the cases with a dilated sigmoid colon image generally in the left upper abdominal quadrant in addition to multiple small intestinal air-fluid levels (Figure 1E). 2,4,24,27,28,37,56,59,62,63,66 I][64][65][66][67] Diagnostic endoscopy is also helpful in 75%-98% of SV cases by presenting a luminal twisting of the sigmoid colon lumen at a 20-30 cm distance from the anal verge (Figure 1K), while it remains incapable in the demonstration of ISK. 18,68Despite advanced techniques, 5%-10% of SV cases and 10%-30% of ISK cases are diagnosed at laparotomy with the abovementioned anatomical findings (Figure 1L and M). 2,4,7,18,66Misdiagnosis generally comprises nonspecific intestinal obstruction or acute abdominal emergency in SV, while additionally SV is a diagnostic mistake in ISK, and most of these cases require emergency action and surgery. 4,6,18,66

Treatment and Prognosis
In SV, following a rapid and effective resuscitation, endoscopic decompression is the primary treatment option with 55%-94% of success, 0%-2% of mortality, 2%-20% of morbidity, and 15%-55% of recurrence rates. 1,2,4,21,24,48,62,66,68- 70For this purpose, rigid or preferably flexible endoscopes are used.Although flatus tubes are traditionally used following decompression, their recurrence preventive role is debated. 68ome selected nonelderly and well-conditioned patients are directed elective surgery consisting of sigmoid colectomy with 0%-2% of mortality, 5%-15% of morbidity, and 0%-1% of recurrence rates. 2,4,8,21In this field, laparoscopic procedure with natural orifice specimen extraction is the current option. 71On the other hand, patients with indefinite diagnosis, gangrenous stool, or peritoneal irritation findings during the admission in addition to unsuccessful endoscopic decompression are treated with emergency surgery.If the sigmoid colon is viable, surgical decompression alone (mortality 0%-5%, morbidity 5%-15%, and recurrence 15%-55%) may be performed, but a recurrence-reducing procedure such as sigmoidopexy, mesopexy, or mesoplasty (mortality 1%-10%, morbidity 10%-25%, and recurrence 10%-20%), or preferably sigmoid colectomy (mortality 1%-10%, morbidity 15%-25%, and recurrence 0%-1%) may also be added.Percutaneous endoscopic colopexy may be an alternative in elderly and badconditioned cases with 8%-15% of mortality, 13%-28% of morbidity, and 0%-15% of recurrence rates.[70] In ISK, emergency surgery following rapid and effective resuscitation is essential.In nongangrenous patients, decompression alone (mortality 1%-5% and morbidity 5%-15%) or in some selected nonelderly and well-conditioned patients, to prevent SV recurrence, sigmoid colopexy, mesopexy, or mesoplasty (mortality 1%-8% and morbidity 10%-20%) ore even sigmoid colectomy with primary anastomosis (mortality 1%-10% and morbidity 15%-25%) may be used.In patients with single-segment bowel gangrene, ileum or sigmoid colon resection with primary anastomosis (mortality 5%-20% and morbidity 10%-30%) or stoma (mortality 20%-50% and morbidity 30%-40%) is preferred, while patients with double-segment gangrene are treated with resection of both ileum and sigmoid colon in addition to doublesegment primary anastomosis or ileum primary anastomosis and sigmoid stoma with 10%-60% of mortality and 20%-40% of morbidity rates. 5,7,9,17,18,22,23,24,28,38,56,61,62,64,67,72ecial Conditions Childhood Sigmoid volvulus in childhood is a very rare clinical entity with a few 10 cases reported to date, whereas pediatric ISK is extremely rare declared little more than 20 patients.Diagnosis is more difficult due to the inability of both medical history and physical examination.Abdominal pain and distention are the main clinical features, while vomiting and diarrhea are more common when compared with that of adults.Computed tomography is the best diagnostic procedure, while endoscopic decompression by using flexible pediatric endoscopes is the primary treatment option in SV.The prognosis is worse than that of adults with 8%-40% and 15%-60% of mortality rates, respectively, while morbidity rates are 15%-50% and 20%-60%, respectively, in SV and ISK.Sigmoid volvulus tends to recur in early-onset SV or ISK, and for this reason, elective sigmoid colectomy is frequently recommen ded. 2,10,11,21,23,73egnancy Although SV is in the first 2 causes of intestinal obstruction in pregnancy, the total number is little more than 110 cases, whereas ISK is less often declared less than 20 patients.Clinical presentation of SV and ISK may sometimes be complex due to some physiologic features of pregnancy including nausea, vomiting, and abdominal pain.Although a single x-ray radiogram is allowed, flexible endoscopy and preferably MRI are the current diagnostic tools in SV, while MRI is the unique identifier in ISK.In SV, an enlarged uterus is thought as a preventer, even so, endoscopic decompression is the first treatment option.74 Elderliness About one-third of SV occurs in geriatric patients with a higher recurrence rate when compared with that of children and also adults.]75 Peer-review: Externally peer-reviewed.Funding: The authors declared that this study has received no financial support.