Conservative management of massive pneumoperitoneum after argon plasma coagulation.

Argon plasma coagulation (APC) is a safe and effective technique that is widely used for the treatment of gastrointestinal vascular lesions. It is considered the technique of choice for the management of these lesions. Rendu–Osler–Weber disease is a condition characterized by the appearance of arteriovenous malformations of the skin, mucous membranes and various organs, typically presenting gastrointestinal bleeding. APC has proven to be an effective technique for the treatment of these patients. It has been described that the contact of the probe with the mucosa or the high flow of argon can lead to a gas leak through the gastrointestinal wall or even, in some cases, perforation of a hollow organ. The presence of pneumoperitoneum after APC can be asymptomatic and caused by the passage of gas through the gastrointestinal wall. In many cases, the treatment of choice is conservative. We present a case of massive pneumoperitoneum after APC treated with conservative management with demonstrative imaging studies. The patient is a 57-year-old woman under treatment with APC (Argon ERBE APC-300) due to gastric and duodenal angiodysplasias secondary to Rendu–Osler–Weber disease. After one session, she came to the emergency room with abdominal distension and epigastric pain that had been progressing for 12 h. The patient presented a distended abdomen that was slightly painful, with no signs of peritoneal irritation. Chest radiograph revealed a massive pneumoperitoneum (Fig. 1). Triple-contrast CT detected abundant pneumoperitoneum with no free fluid; no area of dehiscence was observed, and there was no extravasation of water-soluble oral contrast (Fig. 1). While in the emergency department, a series of analyses showed no elevated acute-phase reactants, and the patient remained asymptomatic. In view of the clinical–analytical–radiological findings, we decided on observation and conservative management with nil per os, a nasogastric tube and iv ertapenem 1 g/24 h. No complications were observed during hospitalization, and the patient was discharged after 6 days. After discharge, a clinical-radiological follow-up showed a gradual reduction of the intra-abdominal air volume (Fig. 2). In the literature, there are few reported cases of massive pneumoperitoneum after APC: 3 in the management of colon polyps, and 2 in the treatment of angiodysplasias. In 3 of these patients, conservative treatment was used without complications, while in the other 2, exploratory laparotomy was performed initially but no perforation was observed. There are probably many more cases of pneumoperitoneum after APC than those reported. If systematic abdominal radiographs were performed after each treatment, we would find a high number of cases of asymptomatic pneumoperitoneum. When faced with the finding of pneumoperitoneum after APC, we should not automatically assume that there is a perforation of a hollow viscus; instead, it may be caused by the passage of gas through the gastrointestinal wall. It is essential to identify those patients who have perforated hollow viscus, who will require urgent surgery, and to differentiate them from patients with an accumulation of intra-abdominal air simulating perforation, but which is really caused by the passage of gas through the gastrointestinal wall, c i r e s p . 2 0 1 8 ; x x ( x x ) : x x x – x x x