Discussion:
Although sigmoidal diverticulitis is a prevalent medical-surgical condition, the clinician may be misled in his or her diagnosis due to the plethora of findings. Indeed, depending on the location along the colonic tract and the pattern of acutisation, the presentation varies from a consolable complaint to a visceral failure. We describe through this clinical case a retropneumoperitoneum secondary to a sigmoiditis by detailing the reasoning behind our approach. The causes of retropneumoperitoneum to be listed are rupture of the duodenum, perforation of the rectum, post-colonoscopy or ERCP procedure, colon perforation, extension from pneumomediastinum or gas-containing retroperitoneal abscess [1].
Due to a suitable anatomy combining a parietal weakness at the mesenteric border and a loose cellulo-lympic atmopsphere, the diverticulum can perforate and fuse into the retroperitoneum. It will then reach the mediastinal layer by diffusing through the perineural and perivascular sheaths and will escape in the posterior medial space through the esophageal and aortic hiatus. This inter-compartmental crossing is facilitated by a negative intra-thoracic pressure opposed to a positive intra-abdominal pressure [2].
This perforative event could be accompanied by pyo-stercoral spillage complicating this complication by inflicting purulent fuses along the loose connective tissue of the retroperitoneum. Due to the solid nature of the stool of the descending colon and the constipation tendency in carriers of colonic diverticulosis, the retroperitoneal perforation could be resumed in a gas leak. Fortunately for our patient, we faced the most clement case. Thus, he was not deemed to require surgery at the time. The amount of air does not correlate with the severity of the symptoms [3], the therapeutic attitude is conditioned by the clinical tolerance and the response to conservative treatment. Surgical treatment should be reserved for extensive pneumoretroperitoneum that does not respond to symptomatic treatment. During this therapeutic window, energetic monitoring is imperative to watch for cardiac or respiratory complications related to pericardial tompanade or pneumothorax or suffocating cervical emphysema.