It Is Tough to Make Predictions, Especially about the Future

Three lessons can be learned from this: first, there is a need for a less invasive and preferably reversible technique for lung volume reduction. Secondly, there is a need for prospective, randomized and (preferably sham) control of these techniques, and thirdly, there is a need for an a priori selection of patients, to predict the future. So, are there less invasive techniques out there? Interventional pulmonologists, surgeons, investigators, small venture capital firms as well as big device and instrument companies have come up with a variety of minimally invasive techniques and devices. These can be roughly categorized [5, 6] as reversible blocking devices, including endobronchial blockers or plugs such as the silicone plug described by Watanabe et al. [7] and endobronchial valves such as the Zephyr  valve (Pulmonx Inc., Palo Alto, Calif., USA) [8] , the Miyazawa silicone valve from Novatech, La Ciotat, France [9] , or the valve from Spiration, Redmond, Wash., USA [10, 11] , reversible non-blocking devices (lung volume reduction coils of PneumRx, Mountain View, Calif., USA) [12] , and irreversible non-blocking techniques (bronchoscopic thermal vapor ablation using the apparatus from Uptake Medical, Seattle, Wash., USA [13] , and the polymeric lung End-stage emphysema is a horrible because incurable and invalidating disease. Prior to the advent of lung transplantation – which is in fact the only definitive but obviously very limited therapy – surgeons have tried to improve pulmonary function by resecting (the most diseased) portions of the lung. Essentially, this lung volume reduction surgery (LVRS) is thought to improve matching of the size of the lung to the size of the hemithorax containing it, and to allow the space previously occupied by the sickest lung to be reclaimed by more normal lung [1] . Although all of this might be true, the bottom line question is: did it make patients better? Because of the amazing power of expectations of patients as well as physicians in new treatments and techniques, controlled trials (preferably with sham procedures in the case of device trials) are mandatory [2] . After a few decades of ‘wild’ LVRS, a properly controlled (albeit not sham-controlled) prospective randomized trial [3] showed that there was indeed some true clinical benefit to be expected from LVRS, but only in a (post-hoc) well-defined subgroup of patients, with hyperinflation, severe but not-too-severe diffusion capacity decrease, heterogeneously upper-lobe distributed emphysema and a decreased exercise capacity; in all other patients, LVRS was not only useless, but even harmful, taking into account its huge morbidity, cost and even mortality. LVRS has since become an exceptional treatment modality [4] . Published online: October 6, 2010