Mediastinal Lymph Node Dissection in Video-Assisted Thoracoscopic Lobectomy

We read with great interest the article “Complete mediastinal lymph node dissection in video-assisted thoracoscopic lobectomy versus lobectomy by thoracotomy” by Yang et al.[1] Although the first thoracoscopic lobectomy was first described exactly 20 years ago,[2] the groundbreaking article was published by McKenna in 2006.[3] This surgeon, reporting his experience on 1100 cases, demonstrated that video-assisted thoracic surgery (VATS) lobectomy can be performed with low mortality and morbidity rates. Unfortunately, no large multicentre randomized trial comparing VATS to open lobectomy is available and considering that the data for the two approaches were so similar, it is extremely unlikely that such a trial will ever be realized. A study on 12,958 patients from the Surveillance, Epidemiology, and End-Results Medicare database between 1994 and 2002 demonstrated that only 6% of the patients underwent a VATS lobectomy.[4] Several reasons might explain the infrequent use of VATS lobectomy: insufficient training or experience, insufficient evidence to confirm the safety of VATS technique, concern about obtaining negative margins or adequate staging of mediastinal lymph nodes, and fear of cancer dissemination. In more recent years, the trend is for a greater proportion of lobectomies to be performed by VATS and data from the Society of Thoracic Surgeons General Thoracic Surgical database demonstrate a 22% rate in 2007, increasing to almost 40% in 2010.[5] On the contrary, disagreement persists in Europe, where VATS lobectomy is performed less often than in the United States or Japan.

In this context, the institutional report from China is useful. Yang et al[1] well demonstrated the efficacy of the VATS lobectomy in achieving a complete mediastinal dissection. The number of lymph nodes dissected with VATS technique was remarkably high and similar to the open technique. Our personal experience in VATS lobectomy can be considered comparable; in addition, we would like to stress the use of the UltraCision harmonic scalpel (Ethicon Endo-Surgery, Cincinnati, Ohio, United States) for the mediastinal dissection. Ultrasonic dissection technology works by producing a high-frequency ultrasound that causes intracellular fluid evaporation and cellular destruction that result in separation of tissue planes simplifying the dissection. Moreover, ultrasonic energy produces the denaturation of proteins and the change from colloidal proteins into an insoluble gel that is able to seal the vessel walls. A characteristic of the harmonic scalpel is the minimal lateral spread of the vibration current and thermal energy in the surrounding tissues minimizing the risk of injury; this peculiarity has estimable value considering that the mediastinal dissection is close to important nervous and vascular structures.

In conclusion, the article by Yang et al[1] is an example of how the mediastinal lymph node dissection could be performed during VATS lobectomy and we believe that ultrasonic dissection can further facilitate these good results.

• References

• 1 Yang H, Li XD, Lai RC , et al. Complete mediastinal lymph node dissection in video-assisted thoracoscopic lobectomy versus lobectomy by thoracotomy. Thorac Cardiovasc Surg 2012 (e-pub ahead of print). DOI: 10.1055/s-0031-1299589.
• 2 Roviaro G, Rebuffat C, Varoli F, Vergani C, Mariani C, Maciocco M. Videoendoscopic pulmonary lobectomy for cancer. Surg Laparosc Endosc 1992; 2 (3) 244-247
• 3 McKenna Jr RJ, Houck W, Fuller CB. Video-assisted thoracic surgery lobectomy: experience with 1,100 cases. Ann Thorac Surg 2006; 81 (2) 421-425 , discussion 425–426
• 4 Farjah F, Wood DE, Mulligan MS , et al. Safety and efficacy of video-assisted versus conventional lung resection for lung cancer. J Thorac Cardiovasc Surg 2009; 137 (6) 1415-1421
• 5 Boffa DJ, Gangadharan S, Kent M , et al. Self-perceived video-assisted thoracic surgery lobectomy proficiency by recent graduates of North American thoracic residencies. Interact Cardiovasc Thorac Surg 2012; 14 (6) 797-800