Pulmonary function following completion of Minimally Invasive Repair for Pectus Excavatum (MIRPE)

Pulmonary function testing remains part of the routine preoperative investigations in patients with pectus excavatum, although there is evidence that reduced exercise capacity is predominantly due to impaired cardiovascular performance rather than ventilatory limitation.

To evaluate the change of pulmonary function in patients after completion (metal bar removal) of minimally invasive repair for pectus excavatum compared to the preoperative functional results.

All patients who underwent minimally invasive repair for pectus excavatum (MIRPE) between February 2000 and June 2006 and subsequently had their metal bars removed were examined. Pulmonary function tests were performed as part of the routine pre- and postoperative protocol. Vital capacity (VC), forced expiratory volume in one second (FEV1), total lung capacity (TLC), residual volume (RV) and maximal expiratory flow rate at 25 % (MEF25) were evaluated. In addition, comparisons were made between patients with a low ( 6) pectus severity index (PSI) to establish the relative pre- to postoperative change of the above-mentioned lung function parameters.

Fifteen patients were included in the study (14 males, 1 female). The median age at surgery was 15.9 years. The metal bar(s) were removed after a median of 37 months following the initial operation. Lung function tests were performed at a median of 32 days preoperatively and 129 days after completion of the procedure. Preoperative lung function values lay below population averages. The majority of patients had either a restrictive, obstructive or combined pulmonary disorder. Improvement was observed in all lung function parameters after metal bar removal compared to preoperative values and was significant for VC, FEV1 and the RV/TLC ratios. With regard to the severity of the deformity, although not statistically significant, patients with a higher PSI (> 6) appeared to benefit particularly from the operation.

Our findings indicate that pulmonary function improves in patients after completion of minimally invasive repair of pectus excavatum. However, a review of the literature suggests that, in all probability, following surgery, patients benefit more with regard to enhanced cardiovascular performance than from improved pulmonary limitations. The value of routine testing of pre- and postoperative lung function in patients with pectus excavatum is questionable.