Benign emptying of the postpneumonectomy space.

BACKGROUND

A fall in the postpneumonectomy fluid level is considered a sign of bronchopleural fistula (BPF) requiring surgical intervention. We have discovered however that in rare asymptomatic patients, this event may not require aggressive surgical treatment.

METHODS

After seeing a case of benign emptying of the postpneumonectomy space (BEPS), we surveyed 28 surgeons to determine its incidence and characteristics.

RESULTS

Forty-four cases of BEPS were reported by 23 survey respondents. Among 7 fully documented cases from 4 institutions, we defined the following criteria: the patient must be asymptomatic (no fever, white cell count elevation, or fluid expectoration), negative culture results if fluid sampled (patient not receiving antibiotics), no BPF at bronchoscopy or ventilation scintigraphy scan (or both), and recovery without drainage, or retrospective assessment that the intervention was unnecessary. BEPS occurred between 5 days and 152 days after pneumonectomy (6 cases right pneumonectomy and 1 case left pneumonectomy). Four patients underwent no treatment, 1 patient underwent thoracoscopic exploration (sterile) and closure after antibiotic irrigation, 1 patient underwent thoracoscopic exploration alone, and 1 patient underwent open window thoracostomy (sterile) with eventual closure. In all 7 patients (except the patient who underwent the open window procedure) the space refilled within 8 weeks; no patient experienced a subsequent empyema/BPF. Four patients who met the initial criteria for BEPS went on to experience empyema. The incidence of BEPS appears related to pneumonectomy volume, particularly extrapleural pneumonectomy. Using surgeon volume assumptions, the incidence of BEPS is 0.65%.

CONCLUSIONS

To our knowledge, BEPS is a previously unreported occurrence. We hypothesize that it results from postoperative intrapleural pressure shifts, with or without a microscopic BPF, that drive fluid out of the pleural space while failing to cause contamination. Awareness of BEPS' existence may allow surgeons to safely avoid open drainage procedures occasionally in patients who experience an asymptomatic fall in fluid level.