Ectopic air localizations after transanal procedures. A systematic literature review

Background: Aim of this study is to report and to analyze the incidence, clinical impact and treatment options of ectopic air localizations after transanal procedures. Methods: A systematic literature review was performed using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. The research was carried out using the PubMed database, identifying 40 articles with the following keywords: “transanal” AND “emphysema”; “transanal” AND “subcutaneous emphysema”; “transanal” AND “pneumomediastinum”; “transanal” AND “pneumothoraces”; “transanal” AND “pneumopericardium”; “transanal” AND “retropneumoperitoneum”. Results: Nineteen articles, published between 1993 and 2017, were included in the study for a total of 29 patients. The most frequent air localization was in the retroperitoneum, followed by subcutaneous tissues, mediastinum and neck. This condition was treated conservatively in 20 patients, with colostomy in 4 patients, with bowel resection and negative diagnostic laparoscopy in one patient each. In three cases the treatment was not specified. Ectopic air location resolved in all cases. Conclusions: Pneumo-mediastinum and pneumo-retroperitoneum after transanal procedures are unusual complications with a dramatic radiological appearance but can be managed successfully with a completely benign course in most cases. Initially, a conservative approach is recommended. Surgical treatment should be reserved only in case of fluid collection or suture dehiscence.