Does mechanical pleurodesis result in better outcomes than chemical pleurodesis for recurrent primary spontaneous pneumothorax?

A best-evidence topic was written according to a structured protocol. The question addressed was whether mechanical pleurodesis results in better outcomes in comparison with chemical pleurodesis in patients undergoing surgery for recurrent primary spontaneous pneumothorax. A total of 542 papers were found using the reported searches, of which 6 represented the best evidence to answer the clinical question. The authors, date, journal, study type, population, main outcome measures and results are tabulated. The studies found compared the outcomes of mechanical and chemical pleurodesis and also focused on the outcomes of the different methods of mechanical pleurodesis: pleural abrasion and pleurectomy. Reported measures were operative mortality, mean operation time, post-operative bleeding, persistent air leaks, chest drain duration, pain levels, pneumonia, respiratory failure, wound infection, pulmonary function, re-exploration for bleeding and air leak, hospital stay, recurrence and re-operation for recurrence. One large cohort study compared the outcomes of mechanical and chemical talc pleurodesis and reported a significant reduction in recurrence with talc pleurodesis in comparison with pleurectomy (1.79 vs. 9.15%, P = 0.00018). Another large cohort study, analysing pleural abrasion, pleurectomy and talc pleurodesis, both in isolation and in combination with apical bullectomy, reported the highest rate of recurrence in bullectomy plus abrasion patients (1.4%) followed by bullectomy plus talc pleurodesis patients (0.4%). No recurrence was seen with other techniques. The reported freedom from surgery at 10-year follow-up was 98.9% with talc pleurodesis, 97.5% with pleurectomy and 96.4% with pleural abrasion, however, with no statistical significance. A prospective randomized study, a retrospective case series review and two smaller cohort studies compared the outcomes of pleural abrasion and pleurectomy as different techniques of mechanical pleurodesis and reported statistically significant shorter operation times, lower rates of post-operative bleeding, re-exploration and pain observed with pleural abrasion and lower rates of recurrence with pleurectomy. Three studies reported the outcomes of apical bullectomy or wedge resection with recurrence rates ranging from 0.4 to 6.2%. We conclude that there is a very similar outcome profile in the comparison of mechanical and chemical pleurodesis, with modest evidence suggesting lower rates of recurrence with chemical talc pleurodesis.