A prospective bicentric study to evaluate surgical outcome and lung function changes after laser-assisted pulmonary metastasectomy

Background:

The surgical resection of pulmonary metastases (PM) is associated with a survival benefit in selected patients. The use of laser-assisted surgery (LAS) for PM has been shown in a variety of retrospective studies to facilitate the complete resection, especially for higher number of metastases, while preserving a maximum of healthy parenchyma. This is the first prospective study to evaluate perioperative surgical, oncologic and clinical parameters including the changes of lung function after LAS.

Material and method:

This is an interim-analysis of a prospective, bicentric, single-arm trial. So far we analyzed 78 operations in which PM was carried out in curative intent. A 1.320nm diode-pumped Nd: YAG-Laser was used for resection of the metastases. Surgical and clinical data were collected using a standardized form and postoperative lung function changes after 3 and 6 months were assessed using whole body plethysmography and diffusion capacity for carbon monoxide (DLCO).

Result:

Median operative time was 129 minutes (range, 55 – 334 minutes) and a median of 3 metastases were resected per operation (range 1 – 23). The median duration of postoperative air leak was 1 day (range 0 – 11 days), and median length of hospital stay was 8 days (range, 4 – 15 days). LAS associated, postoperative minor complications were observed in 7 (9%) cases and there were no mortalities. The analysis of perioperative lung function showed that mean FEV1 3 months after surgery was reduced by 13% (p < 0.0001) and DLCO by 14% (p = 0.001) respectively. There was no relevant regeneration of lung function at 6 months. Decline of DLCO correlated with the number of resected metastases (r = 0.48, p = 0.01). All metastases were radiologically measured for distance to pleural surface and size. Adding up diameter and distance to pleural surface there was a positive correlation to the changes of the residual volume at 3 months (r = 0.52, p = 0.04).

Conclusion:

We present excellent results after LAS even in high numbers of metastases with short duration of postoperative air leak and little morbidity. Number, size and depth of the metastases affect lung function changes after resection, particularly diffusion capacity and residual volume.