Transverse Colon Volvulus

Clinical History

A 55-year-old female with past surgical history of adhesiolysis for small bowel obstruction presented to the emergency department with bilious vomiting, generalised abdominal pain, and distension. Initial clinical biochemical/haematological results were all unremarkable. Her past medical history also included COPD, subarachnoid haemorrhage, epilepsy, psychosis and ectopic pregnancy surgery.

Imaging Findings

A plain abdominal radiograph was performed which demonstrated a large gas-filled hollow viscus in the right abdomen suggestive of large bowel obstruction. There were no features of perforation on erect chest radiograph.

CT body imaging, demonstrated "twirling" of the mesentery and twisting of the transverse colon loop acting as a transition point to dilated large bowel proximally to the caecum. Free fluid was evident within the abdomen and pelvis, although no features of perforation were present. She was treated conservatively with intravenous fluids, nasogastric tube insertion, and broad spectrum antibiotics. Over the course of 3 days there was a spontaneous clinical resolution, proven by clinical improvement and subsquent plain imaging.

Discussion

Spontaneous colonic volvulus of the transverse colon is the rarest (2%) type in comparison to caecal (22%) or sigmoid volvulus (75%) [1, 10]. Literature reveals approximately 100 cases up to 2012 [1, 2]. While 3 - 5% of bowel obstructions are caused by colonic volvulus, transverse volvulus has a female predilection occurring in the second and third decades, with another second peak in the seventh decade [2]. Held by a short mesocolon and a firmly fixed splenic flexure, the transverse colon anatomically is a very resistive part of the intra-peritoneal large bowel to volvulus formation [3].

However, in the elderly and psychiatric patients [4], dolichocolon is a common cause of transverse colonic volvulus where redundancy and elongation due to chronic constipation are present. Otherwise, mechanical causes would include previous surgery, adhesions, inflammatory or malignant strictures. Association between transverse colon volvulus and Chilaiditis syndrome is also a well reported problem [5, 6]. Subsequently, clinical complications include bowel obstruction, infarction, peritonitis and mortality if undiagnosed. One of the rarely reported complications is a formed colonic knot with a concurrent sigmoid volvulus, only identified intra-operatively [1, 7].

Few useful imaging signs on the plain abdominal radiographs can help in detecting the volvulus site. For example, the caecal caput sign with maintained colonic haustra in a caecal volvulus, also the coffee bean sign or inverted 3 sign in sigmoid volvulus. While our case does not categorically offer a recognisable radiographic sign on the initial plain film, an ‘inverted’ coffee-bean sign has been reported previously [8].

Nowadays, computed tomography (CT) scans are extremely useful in detecting the site, degree of twist, causes and complications of a colonic volvulus [10]. The most predictive sign is the ‘twirl’ sign in the root of the mesentery with venous engorgement as demonstrated in our case on coronal views. In fact, biochemical normality and symptoms resolution upon conservative management suggest a subacute progressive clinical presentation and course [2]. This could potentially, if untreated, become a serious acute fulminating type of transverse volvulus. The post-treatment film is confirmatory of spontaneous volvulus resolution. Management in most reports recommends surgery (open surgical colopexy) in favour of endoscopic devolvulation [2, 9].

Though extremely rare, transverse colonic volvulus is an atypical cause for large bowel obstruction worthy of early recognition by reporting radiologists. Once instigated, the ‘twirling’ sign of the colonic mesentery is a very specific CT feature for this condition and its pathological sequelae.

Differential Diagnosis List

Final Diagnosis

Transverse Colon Volvulus

URL:	https://eurorad.org/case/11385
DOI:	10.1594/EURORAD/CASE.11385
ISSN:	1563-4086