CT features of toxic megacolon: A systematic review.

INTRODUCTION: Toxic megacolon is a rare but life-threatening condition. Diagnosis is made when both systemic toxicity and an enlarged colon are present. We undertook a systematic review of the literature to provide a list of toxic megacolon findings on computed tomography (CT) imaging along with the prevalence rate for each finding. METHODS: PubMed, Embase, and Cochrane library were searched. After eligibility screening and quality assessment, the reported CT findings of toxic megacolon with their respective prevalence rates were extracted from the included studies. Pooled prevalence rates were calculated for each finding using random-effects model and inverse variance method. I2 statistics were used to estimate the heterogeneity. All statistical analyses were performed using R software. P-values less than 0.05 were considered significant. RESULTS: Database search yielded a total of 122 records. Only 2 of these studies were finally selected following two-step eligibility screening. Most common CT features of toxic megacolon and their pooled prevalence rates [95% CI] were: colonic distension (reported in 100% of patients), abnormal haustration 96% [0.75-0.99], peri-colonic fat stranding 87% [0.29-0.99], nodular pseudo polyps 76% [0.52-0.91], multilayered appearance of colonic wall 58% [0.38-0.76], and ascites 57% [0.21-0.87]. Other reported CT features: colonic wall thickening, pleural effusion, accordion sign, small bowel/gastric distension, and segmental colonic wall thinning. CONCLUSION: and implication for practice: Colonic distension can be accompanied by 10 other findings in CT images of patients with toxic megacolon. Although these findings are not specific, toxic megacolon should be included in the list of differential diagnoses when these findings are present.

When leucocytosis is not leukaemia.

A female aged 84 years with a history of Clostridium difficile-associated diarrhoea presented from an extended care facility with altered mental status and respiratory distress. She was haemodynamically unstable and initial laboratory results revealed hyperleucocytosis (110.3×109/L). The presence of immature myeloid precursors, thrombocytopenia and respiratory distress, raised concern for an acute leukaemic process requiring emergent leucapheresis. However, on evaluation of the peripheral smear, prominent left shift and toxic granulation were noted, along with absence of blast cells. Considering her history of C. difficile infection, a CT scan of the abdomen and pelvis was obtained, which was suggestive of toxic megacolon. She was taken to the operating room for emergent colectomy. The pathology specimen showed pseudomembrane formation consistent with fulminant C. difficile infection. She was treated with oral vancomycin and intravenous metronidazole, followed by clinical improvement and resolution of leucocytosis and thrombocytopenia.

Community-acquired fulminant colitis caused by binary toxin-producing Clostridium difficile in Japan.

We report a case of community-acquired fulminant colitis caused by Clostridium difficile in Japan. A 46-year-old woman was diagnosed with severe infectious enterocolitis and was admitted at another hospital. The stool culture was positive for toxigenic C. difficile. Since the patient presented with fulminant C. difficile infection (CDI) with toxic megacolon, respiratory insufficiency, and circulatory failure, she was transferred to Kyorin University Hospital for intensive care. Intubation and antibiotic therapy were performed. The general condition improved with conservative treatment, and she was discharged without sequelae. While the recovered isolate was toxin A and B-positive and binary toxin-positive, it was identified as polymerase chain reaction (PCR) ribotype ts0592 and slpA sequence type ts0592. The isolate was different from PCR ribotype 027 epidemic in Europe and North America. In Japan, binary toxin-producing strains are rare and have not caused an epidemic to date. Furthermore, there are few data on community-acquired CDI in Japan. In this case, a non-elderly woman with no major risk factors such as antibiotic use, administration of proton pump inhibitor and history of gastrointestinal surgery developed community-acquired fulminant CDI caused by the binary toxin-positive strain, and ICU treatment was required. Further studies focusing on the role of binary toxin-positive C. difficile in the severity of community-acquired CDI are necessary.

The Surgical Treatment of Toxic Megacolon in Hirschsprung Disease.

OBJECTIVES: Enterocolitis remains the most significant cause of morbidity and mortality in Hirschsprung disease (HD). It could progress into toxic megacolon (TM)-acute dilatation of the colon as accompanying toxic complication of Hirschsprung enterocolitis. It is a devastating complication, especially in infants with so far undiagnosed HD. METHODS: A retrospective analysis of medical records of 4 infants with TM was performed. The diagnosis TM was determined on the basis of clinical information (abdominal pain or tenderness, abdominal distension, diarrhea, bloody diarrhea, and constipation), plain x-rays of the abdomen (segmental or total colonic dilation), and the presence of such criteria (fever, high heart rate, increased white blood cell count, C reactive protein, anemia, dehydration, electrolyte disturbances, hypotension). Surgical management and outcome was evaluated by retrospective chart review. RESULTS: The median duration of symptoms characteristic for TM was 3 days. Toxic megacolon was seen as the first manifestation of previously unknown HD in 3 patients; in 1 newborn, the contrast radiograph was suggestive of HD. In all patients, conservative treatment was failed. Three patients were treated with surgical decompression and ileostomy only. In all these cases, severe complications occurred, consequently 2 of them died. In 1 patient, a resection of the transverse dilated colon additionally was performed. This patient had no complications in postoperative period and survived. CONCLUSIONS: Because of the high mortality in patients with TM that were treated medically or with colonic decompression, a resection of massively distended part of the colon should be performed.

[Primary manifestation of Chrohn's disease with toxic megacolon in a patient with long-time primary sclerosing cholangitis]. / Debut af morbus Crohn med toksisk megacolon hos en patient med mangeårig primær skleroserende kolangitis.

A 38-year-old man with a ten year long history of primary sclerosing cholangitis without previous symptoms of inflammatory bowel disease was admitted to hospital after a few weeks with abdominal pain, diarrhoea and fever. A computed tomography revealed that the colon was dilated to a diameter of 17 cm. Based on a diagnosis of toxic megacolon, a subtotal colectomy and an ileostomy were carried out. Gross and histological examination showed changes compatible with Crohn's disease. Ten years' history of primary sclerosing cholangitis before onset of inflammatory bowel disease is very unusual, and toxic colon as the initial symptom of Crohn's disease is rare.

Toxic megacolon in patients with severe acute colitis: computed tomographic features.

OBJECTIVE: The objective of the study was to evaluate computed tomography (CT) in the differential diagnosis of patients with toxic megacolon (TM) complicating severe acute colitis (SAC) and patients with SAC but no TM. MATERIALS AND METHODS: We identified 16 patients who presented clinically complicated SAC and CT examination before surgery. The CT scans of these patients were retrospectively evaluated in consensus by two abdominal radiologists blinded to the clinical and pathological results for CT findings of SAC, i.e., diffuse colonic wall thickening, submucosal edema, pericolonic fat stranding and ascites, and CT findings of TM reported in the literature, i.e., segmental colonic wall thinning, air-filled colonic distension over 6 cm with abnormal haustral pattern, nodular pseudopolyps and associated small bowel distension. Fisher's Exact Test was used for all statistical analyses. RESULTS: Segmental colonic wall thinning with abnormal haustral pattern was noted in TM only (P=.001). As compared to patients with SAC but no TM as a complication, patients with TM showed statistically more frequent air-filled colonic distension over 6 cm (P=.001) and nodular pseudopolyps (P=.001). Diffuse colonic wall thickening (P=.036) and submucosal edema (P=.036) were more present in cases of uncomplicated SAC. Pericolonic fat stranding (P=.12), ascites (P=.6), and small bowel and gastric distension (P=1) were not distinctive criteria. CONCLUSION: Computed tomography is useful in distinguishing patients with TM from patients with SAC but no TM as a complication. The association of air-filled colonic distension >6 cm, abnormal haustral pattern and segmental colonic parietal thinning seems pathognomonic of TM and should lead to rapid surgery.

Rotavirus gastroenteritis complicated with toxic megacolon.

UNLABELLED: Rotavirus is a leading cause of gastroenteritis in young children, which may indicate hospitalization due to dehydration and electrolyte imbalance. Most cases are self-limited with good prognosis. The association between rotavirus and toxic megacolon has never been mentioned in the literature. We report a case of toxic megacolon secondary to rotavirus gastroenteritis. CONCLUSION: Toxic megacolon can occur in patients with rotavirus gastroenteritis. An abdominal radiograph should be taken for patients with rotavirus gastroenteritis who have systemic toxicity and persistent abdominal fullness.

Toxic megacolon in children with inflammatory bowel disease: clinical and radiographic characteristics.

BACKGROUND: Toxic megacolon (TMC) denotes a rare clinical syndrome accompanied by colonic dilatation, and is a serious complication of inflammatory bowel disease (IBD). This study assessed the clinical and radiologic characteristics of TMC in children with IBD. METHODS: A systematic search identified patients with IBD-associated TMC and matched them by age to controls with ulcerative colitis without evidence of TMC. Clinical characteristics and outcomes were compared with conditional logistic regression. Abdominal X-rays were interpreted by two blinded radiologists and findings were compared with controls. RESULTS: Ten children with TMC (median age 12.6 [7.3-15.5] yr) were matched with 20 controls (median age 12.8 [6.8-15.2] yr). Altered level of consciousness and hypotension were rare in children with TMC. Fever (P= 0.005), tachycardia (P= 0.0001), dehydration (P= 0.01), and electrolyte abnormalities (P= 0.0002) were more common in children with TMC than controls. Air-fluid levels (P= 0.005), intestinal thickening (P= 0.006), and abnormal colonic haustra (P= 0.012) were more commonly seen on X-rays of TMC cases. Transverse colon luminal diameter >or=56 mm was strongly suggestive of TMC (sensitivity 90%, specificity 90%, area under the ROC curve 0.91). No child with TMC died and 70% required colectomy during admission. Two of the three with intact colons at discharge required second-line therapy during the subsequent year. CONCLUSIONS: Colonic dilatation >or=56 mm in children with IBD strongly suggests TMC, if clinical signs are present. Mental alteration and hypotension may be less common in children than in adults. TMC in children with IBD is associated with poor outcome, with a high rate of corticosteroid failure.

A cluster of rotavirus enteritis in adult transplant recipients.

Diarrhea following solid organ transplantation is a common side effect of some immunosuppressive agents but can also be caused by many pathogens. An outbreak of rotavirus (RV) enteritis presenting with severe diarrhea in four solid organ recipients was analyzed. The first case was diagnosed in a 6-month-old liver recipient who was prehospitalized on a pediatric ward. Within 1 month, three adult patients (two liver, one renal recipient) presented with enteritis. During diarrhea a significant rise in tacrolimus levels was observed. One patient developed toxic megacolon with ulcerative colitis. Infections were self-limiting but led to secondary infectious complications and prolonged hospitalization. This is the first reported outbreak of RV enteritis in a multiorgan transplant unit involving adult patients. Although no fingerprinting or subtyping of the virus was performed we assume the child was the primary source. In transplant recipients presenting with diarrhea RV infection should be considered.

The abdominal radiograph: a pictorial review.

The plain abdominal radiograph is one of the most frequently requested X-ray examinations by junior surgical and accident and emergency staff. Interpretation is often difficult, but this review outlines normal appearances, suggests a strategy for evaluation, and covers the common pathological appearances seen in hospital practice.

Toxic megacolon: role of CT in evaluation and detection of complications.

The purpose of this study is to determine the role of CT in the evaluation and in detecting complications in patients with toxic megacolon. A retrospective analysis of CT findings of 18 consecutive patients with toxic megacolon was performed. Underlying etiology included 12 patients with pseudomembranous colitis (PC), four patients with ulcerative colitis and two patients with cytomegalovirus colitis. Eleven patients were HIV+. CT features, correlation with severity of disease and development of complications were analyzed. Colonic dilatation with intraluminal air and/or fluid with a distorted colonic contour or an ahaustral pattern was seen in all patients. In four patients (22%), CT depicted complications-two colonic perforations and two septic thrombosis of the portal system. Six patients died (33%), three of whom had the above complications. The presence and degree of submucosal edema (accordion sign, target sign), wall thickening, degree of dilatation, nodular contour and ascites did not correlate with clinical outcome. Two thirds of patients with toxic megacolon had PC as the underlying etiology. CT was helpful in depicting diffuse colitis, and it was instrumental in detecting life-threatening abdominal complications, contributing to the management of these patients. CT abnormalities cannot be used to predict the clinical outcome unless complications develop.