Results of Video-Assisted Techniques for Resection of Lung Cancer

Definitions

Video-assisted thoracoscopic surgery (VATS) is used for wedge resection, segmentectomy, lobectomy, pneumonectomy, sleeve lobectomy, lobectomy with chest wall resection, and extrapleural pneumonectomy. The approaches vary substantially: reports on VATS lobectomy alone describe the use of one to six incisions from 4 cm to 10 cm in length, with and without rib spreading. In general, however, VATS lobectomy is interpreted to mean an anatomic lobectomy with ligation of individual bronchi and vessels and lymph node dissection or sampling using a minimal number of ports without a retractor or rib spreading.

A clear definition of VATS lobectomy is needed. The Cancer and Leukemia Group B established a definition of VATS lobectomy for a prospective, multi-institutional trial, and this definition has been widely adopted. A VATS lobectomy is defined as involving no rib spreading; maximum incisions of 8 cm; dissection of individual veins, arteries, and airways for the lobe in question; and node sampling or dissection identical to open thoracotomy. This definition was endorsed by most of the 55 experts participating in the 20th Anniversary of VATS Lobectomy Conference: The Consensus Meeting, organized by the Scientific Secretariat and the International Scientific Committee of the International VATS Lobectomy Consensus Group. However, several participants thought that a small retractor should be acceptable in specific circumstances, for example, when performing complex procedures such as bronchoplasty or when delivering a large specimen.

Some surgeons have suggested that VATS should include only procedures done exclusively with visualization on a monitor. This criterion should be abandoned for several reasons. The most important issues for patients with malignant diseases are the incisional trauma, achievement of curative surgery, and subsequent oncologic outcomes. Occasional viewing through a 4-cm, non–rib-spreading incision does not change the nature of the procedure. A hybrid VATS approach using both a monitor and direct vision without rib spreading or a robotic approach can provide a three-dimensional understanding of anatomy as well as magnified proximity visualization and would surely clinically facilitate complex procedures such as sleeve lobectomy or segmentectomy.

Technical aspects of how to accomplish a VATS lobectomy are beyond the scope of this chapter and are the subject of surgical atlases. Styles vary in how surgeons perform different steps of the operation. The essential feature, however, is a hilar dissection and individual division of the vessels and bronchus of the lobe. Most often, these structures are divided using an endostapler, but ligation, division between clips, or sealing with energy devices is also feasible for smaller vessels.

Outcomes: Comparison of Vats and Open Lobectomy

The scope of what can be successfully performed thoracoscopically includes pneumonectomy, segmentectomy, sleeve lobectomy, and lobectomy with chest wall resection. However, the literature is too limited for most of these procedures to define outcomes, and the results are confounded by patient selection, making assessment of the impact of the VATS approach per se difficult at best.

By contrast, the literature on VATS lobectomy for cancer is so abundant that we have chosen to focus our review on meta-analyses and large outcomes studies. Only a few randomized controlled trials were conducted; these were early in the VATS experience and were small, underpowered studies. As the procedure matured and experience grew, increasing amounts of nonrandomized data showed that VATS lobectomy for cancer was safe, with outcomes similar to or better than those of open lobectomy. In the United States, the decision was made that a randomized controlled trial of VATS compared with open lobectomy would require a design to prove equivalence, which would necessitate too many patients and would not be worth the expense. Hence, the strongest data come from large outcomes and propensity-matched studies and not randomized controlled trials.

To provide an evidence base for this chapter, a comprehensive literature search was carried out for studies comparing VATS with open lobectomy or segmentectomy for lung cancer. We included reports that involved a meta-analysis, a randomized controlled trial, a propensity-matched or otherwise case-matched study, or an outcomes study using a large multi-institutional database. We did not include reports of individual, single-institution comparative series without case matching. Two systematic reviews were not included because a quality assessment judged them to be poor, and they included studies that were otherwise already captured. One meta-analysis was excluded because it focused only on three propensity-matched studies, which were already included individually. Another was excluded because it used an erroneous code for VATS lobectomy.