Impact of hernia volume on pulmonary complications following complex hernia repair

Despite a multitude of evidence-based prediction models and risk factors for postoperative complications after ventral hernia repair, estimating a patient's risk of postoperative complications after ventral hernia repair remains challenging. In an attempt to improve the preoperative assessment of complex hernia patients, some studies have examined pulmonary changes after hernia repair hypothesizing that large hernias lead to pulmonary changes and increased pulmonary complication rates. Some studies have described a correlation between hernia volume and pulmonary changes, although none provided compelling evidence to identify hernia volume as a risk factor for pulmonary complications. This study evaluates the relationship between hernia volume and postoperative pulmonary complications using computed tomography (CT)-based volume measurements.

Analysis of a prospectively maintained database of consecutive complex hernia patients from 2011 to 2014 undergoing endoscopic (ECST) or open component separation technique (CST) for a hernia defect with a minimum width of 6 cm and visual protrusion of the hernia sac ventral of the rectus abdominis muscles in supine position was performed. Hernia volume was calculated using multiple plane reconstruction of a standard abdominal CT-scan. Noted endpoints were pulmonary complications.

Thirty-five patients underwent ECST (n = 20) or CST (n = 15) with a median defect volume of 474 cm³ (range, 114-2086 cm³). Observed complications were pneumonia (n = 4), pulmonary infiltrate (n = 3), aspiration pneumonia (n = 2), and acute respiratory distress syndrome (n = 1). Univariate and multivariate analyses showed that pulmonary complications were associated with "hernia volume" (P = 0.045; 95% CI: 1.008-1.910).

Hernia volume is a promising risk factor for postoperative pulmonary complications and can be calculated using a standard abdominal CT-scan.