Extensive lethal gas diffusion complicating a ‘benign’ disease

An 83-year-old man was admitted to the emergency department of our hospital for rapid deterioration of the general status and swelling of the left leg. His past medical history was unremarkable. The patient complained of leg pain and intense fatigue. No abdominal pain was noted. At admission, the patient presented with tachycardia (110 bpm) and hypotension (90/50), without fever. Physical examination revealed subcutaneous crepitation in the neck, chest and left leg. Abdominal examination showed a slightly distended abdomen without tenderness. Common laboratory tests revealed an inflammatory response syndrome (leucocytes at 13.4 × 10/L, C-reactive protein at 438 mg/L and procalcitonin at 21.3 ng/mL) with acute kidney failure (creatinine at 326 μmol/L). Serum lactate and pH were within normal limits. An emergency computed tomography (CT) scan confirmed the presence of subcutaneous emphysema extending from the neck to the left leg, below the knee (Figs 1–3). Remarkably, the CT scan also showed pneumomediastinum (Fig. 1), pneumoperitoneum (Figs 1,3) and pneumoretroperitoneum (Fig. 3). The origin of this severe clinical situation was found in a large left colonic diverticular perforation, beginning through the retroperitoneal aspect of the colon (Fig. 3). Therefore, the air gained access to the mediastinal space and neck (cranially) and to the left thigh and knee caudally (Fig. 2). Urgent surgical exploration was performed. At the midline laparotomy, sigmoid perforation was found, confirming the CT findings. Hartmann procedure with an extensive lavage and drainage were performed. The patient was transferred to the intensive care unit for post-operative cares. However, he developed post-operative multiorgan failure syndrome and the outcome was fatal on postoperative day 5. The histological examination of the specimen confirmed the diagnosis of severe diverticular disease with large perforation. Colonic diverticulosis is a frequent benign condition for adults aged more than 65 years. While most people with diverticular disease remain asymptomatic, a percentage of patients ranging from 10% to 25% develop symptoms, although only 15% develop significant complications. Moreover, most of the symptomatic patients can be easily managed with medical therapy (from dietetic advices and antispasmodic drugs to aggressive intravenous broad-spectrum antibiotic treatment). Few patients require invasive procedures such as percutaneous drainage of peritoneal abscess or surgical exploration. The most employed surgical strategies include simple peritoneal lavage and drainage positioning, and minimally invasive or laparotomic colectomy with or without stoma formation. Acute perforation with faecal peritonitis is the most lifethreatening complication, with a reported mortality rate of around 7.8%. Conversely, an acute perforation with purulent peritonitis is expected to resolve with fewer sequelae. The presence of extensive gas diffusion and faecal contamination in an elderly patient could evolve in septic shock, which is a major prognostic factor of mortality after emergency surgical Hartmann