PURPOSE:There is a lack of strong evidence supporting the use of (VATS) lobectomy, with few published randomized trials. The statistical method of calculating propensity scores is a powerful way to compare two cohorts in a non-randomized setting. We applied this method to a case-control series of patients treated with either VATS or open lobectomy in order to increase the validity of the comparison.
METHODS:We compared patients with clinical stage I NSCLC who underwent VATS lobectomy to patients that underwent thoracotomy and lobectomy. Inverse probability of treatment weighted estimators, with weights derived from propensity scores, were used to balance important covariates known to influence perioperative morbidity and mortality (gender, preop FEV1, ASA class, and Charlson Comorbidity Index (CCI)) in the two cohorts. Bootstrap methods provided standard errors. Endpoints were postoperative stay (LOS), chest tube duration, complications, and lymph node retrieval.
RESULTS:We analyzed 139 lobectomy patients. 5/74 (6.7%) VATS lobectomies were converted to open procedures. Operative mortality was 1/65 (1.5%) for open and 1/74 (1.5%) for VATS, P=0.710. Adjusted median LOS was 7 days (open) versus 4 days (VATS), P <0.0001, HR = 0.327. Adjusted median chest tube duration was 5 days (open) versus 4 days (VATS), P<0.0001, HR = 0.417. Percentage of patients with any complication was 42% (open) versus 35% (VATS), P=0.516. Adjusted mean lymph nodes stations dissected (#/patient) was 4.6 (open) versus 4.2 (VATS), p=0.249. Adjusted mean number of lymph nodes retrieved per patient was 18.1 (open) versus 14.7 (VATS), p=0.145.
CONCLUSION:After important risk factors affecting the study endpoints were balanced in each cohort by propensity scoring, VATS lobectomy patients had a highly statistically significantly shorter LOS compared to thoracotomy and lobectomy patients. Mortality and complication rates and lymph node retrieval were equivalent to open thoracotomy and lobectomy.
CLINICAL IMPLICATIONS:Although this study addressed short-term clinical outcomes only, the results support the recommendation that VATS lobectomy is an acceptable if not preferable surgical treatment compared to thoracotomy and lobectomy for patients with clinical stage I NSCLC.
DISCLOSURE:T. Salewa Oseni, None.