Advances in the Diagnosis and Management of Toxic Megacolon

Gastrointestinal Motility Problems in Critically Ill Patients

Gastrointestinal (GI) motility problems are common complications in critical care patients. GI problems contribute to an increased risk of morbidity and mortality. Toxic megacolon (TM) is a type of acquired megacolon categorized as a medical emergency and includes severe inflammation affecting all layers of the colon wall. The high incidence of GI complications in critically ill patients requires the critical care nurse to provide close monitoring of patients at risk and an acute awareness of the causation, signs and symptoms, and treatment of various GI motility disorders, including gastroparesis, ileus, and TM.

Toxic megacolon complicating a first course of Crohn's disease: about two cases

Toxic megacolon is a rare and serious complication of Crohn’s disease. Because of the associated high morbidity and mortality, early recognition and management of toxic megacolon is important. Through two cases of toxic megacolon complicating Crohn’s disease, we assessed the clinical, radiologic and therapeutic characteristics of this complication.

A 35-year-old man presented a first course of Crohn’s disease treated with corticosteroid. He exhibited sudden severe abdominal pain and distension with shock. A plain abdominal radiography revealed toxic megacolon. He underwent medical therapy, but symptoms not relieved. The patient underwent subtotal colectomy with ileostomy. The resected specimen confirmed the diagnosis. Recovery of digestive continuity was performed. Endoscopic evaluation six months later did not shown recurrence. A 57-year-old man presented with severe acute colitis inaugurating Crohn’s disease, was treated with corticosteroid and antibiotics. He exhibited signs of general peritonitis. Computed tomographic examination revealed toxic megacolon with free perforation, showing prominent dilation of the transverse colon and linear pneumatosis. The patient underwent emergent subtotal colectomy and ileostomy. The final histological patterns were consisting with diagnosis of Crohn’s disease associated with cytomegalovirus infection. The patient underwent antiviral therapy during 15 days. Because of the high risk of postoperative recurrence, he underwent immunosuppressive therapy. Recovery of digestive continuity was performed successfully. Toxic megacolon in Crohn’s disease is a serious turning of this disease. We underscore the importance of early diagnosis of toxic megacolon and rapid surgical intervention if improvement is not observed on medical therapy.

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.