Robotic Thoracic Surgery: An Evolution in Progress for the Treatment of Lung Cancer

Abstract

The field of robotic thoracic surgery has exploded in the last five years. Robotic technology allows the surgeon to perform complex operations with smaller incisions. As robotic systems become smaller, more efficient and the surgeons gain more experience, the results will continue to improve. The goal is less trauma to the patient which will decrease hospital stay, complications and lower health care costs, while allowing faster healing and productivity.

Robotic System: Introduction

Currently, there is only one FDA approved robotic system for thoracic surgery. The da Vinci Robotic System (Intuitive Surgical, Inc., Mountain View, CA) consists of three major components. These include a master console for the operating surgeon (See Figure 1), a robotic arm cart (See Figure 2) and a vision cart including optical devices for the robotic camera. The robotic arm cart is placed at the patient’s side and contains three instrument arms and a central arm to guide a two-channel three dimensional camera. Specific instruments (scissors, knife, grasper, needle driver, etc) can be interchanged in any of the three arms (See Figure 3). On the master console, the surgeon handles telemanipulators and optical controls using three-dimensional screen (See Figure 4). Hand movements are transmitted from the surgeon to the handles on the master console to the tips of the robotic instruments, which are attached on the surgical arm cart and enter the patient’s body. The computer system at the master console utilizes software that removes hand tremor and allows for motion scaling (i.e. A large movement of the surgeon’s hand is made to be a fine movement at the tip of the instrument) to improve precision and accuracy.

Figures 1, 2, 3, 4.

The da Vinci Robotic System (Intuitive Surgical, Inc., Mountain View, CA) consists of three major components. These include a master console for the operating surgeon, a robotic arm cart and a vision cart including optical devices for the robotic camera. The robotic arm cart is placed at the patient’s side and contains three instrument arms and a central arm to guide a two-channel three dimensional camera. Specific instruments (scissors, knife, grasper, needle driver, etc) can be interchanged in any of the three arms. On the master console, the surgeon handles telemanipulators and optical controls using three-dimensional screen.

In January 1999, Intuitive launched the da Vinci Surgical System, and in 2000, it became the first robotic surgical system cleared by the FDA for general laparoscopic surgery. In the following years, the FDA cleared the da Vinci Surgical System for thoracic surgery, cardiac, urologic, gynecologic, pediatric and transoral otolaryngology procedures.

Cardiothoracic surgery includes surgical procedures to treat diseases of the heart, lungs, esophagus, great vessels, trachea, mediastium, and chest wall. This paper will review the current state of robotic thoracic surgery in the treatment of lung cancer.

Lung Cancer

Lung cancer (both small cell and non-small cell) is the second most common cancer in both men and women (not counting skin cancer). In men, prostate cancer is more common, while in women breast cancer is more common. Lung cancer accounts for about 14% of all new cancers. The American Cancer Society’s most recent estimates for lung cancer in the United States are for 2012. About 226,160 new cases of lung cancer will be diagnosed (116,470 in men and 109,690 in women). There will be an estimated 160,340 deaths from lung cancer (87,750 in men and 72,590 among women), accounting for about 28% of all cancer deaths. Lung cancer is by far the leading cause of cancer death among both men and women. Each year, more people die of lung cancer than of colon, breast, and prostate cancers combined.¹

As the rate of cigarette smoking has not declined substantially over the last decade and as the population ages and grows, it is predicted that there will be more small lung nodules found that will be amenable to surgical resection than ever before.² A lobectomy is anatomical removal of the entire lobe (including arteries, veins, bronchus, and associated lymph nodes) of lung and is the gold standard for the surgical treatment of lung cancer. The first lobectomies were performed by a thoractomy incision. This incision is made between the ribs, and utilizes a retractor to spread the ribs open so that the surgeons hand can fit between. The spreading to the ribs has been associated with the post-operative complication of pain and the sequelae (pneumonias, atrial fibrillation, deep vein thrombus, etc.) that happen because the patient is unwilling to ambulate adequately do to pain. While this was the only option 40 years ago, it is still the most widespread technique used for major lung surgery.³ Over time the operative and post-operative results have improved with the advancement of anesthesia and critical care, but a thoracotomy is still associated with six to eight days hospitalizations and a 40% complication rate. The recovery time to a functional work status remains over one month.

Video Assisted Thoracoscopic Surgery Lobectomy

With the evolution of computers, mechanical engineering and video processing technologies in the early 1980s, engineers were able to effectively attach a camera to an optic scope. This allowed surgeons to see inside the human body with an incision as small as a centimeter. This technology eventually led to the development of video assisted thoracoscopic surgery (VATS) which allowed thoracic surgeons to perform the same cancer surgery (lobectomy) as well as other thoracic procedures with smaller incisions. The first published report of a VATS lobectomy was in 1992.⁴ Since its introduction some 20 years ago, VATS has gradually gained broader acceptance as an alternative approach for diagnostic and therapeutic procedures for intrathoracic lesions. VATS allows for good exposure of the pleural cavity and the mediastinum, enables extensive dissection and combines all advantages of minimal invasive surgery with little tissue trauma. As with any new technology, there was a learning period for the surgeon. It took about 15 years from the first VATS lobectomy for studies to show clear benefits of a VATS lobectomy. These include shorter length of stay, decreased post-operative pain, tolerance of earlier adjuvant chemotherapy, fewer post-operative complications, shorter home recovery, and improved cosmetic results. Yet, most recent studies show that a VATS lobectomy is performed less than 30% of the time by thoracic surgeons in the US. There is no definitive answer why a VATS lobectomy has not gained widespread use. It has been suggested that the procedure may be technically challenging to many surgeons due to the restricted maneuverability of the current rigid non–articulating VATS instruments as well as the loss of control of the visual field due to the camera being manipulated by an assistant.

Robotic Lobectomy

Many surgeons have started to use robotic systems to overcome some of these limitations of the VATS procedure. This technology incorporates micromechanics providing three-dimensional video imaging, automatic stable camera platforms and telemanipulated flexible effector instruments. In short, robotic instruments are a mechanical evolution of VATS instrumentation. The first use of a robotic system in the performance of a lobectomy was in 2001 by the group in Pisa, Italy.⁵ They performed five lobectomies with no mortality. These lobectomies were performed by the first generation of the da Vinci system. The mean time of surgery was five hours. The patients had their chest tubes for a mean of two days and went home in an average of four days. Since then there have been many studies showing the improving results using this technology. Most of the early series are very small due to the small number of systems at the time in the world (<50) and the novelty of the robotic lobectomy procedure. By 2006, there were about 600 systems in the world, and by 2011 there were 1,500 just in the United States alone.⁶

In 2006, Park et al. demonstrated feasibility and safety of robotic-assisted lobectomy in a first larger series of cancer patients from Memorial Sloan-Kettering Cancer Center (MSKCC).⁷ The robot was used for individual dissection of the hilar structures through two thoracoscopic ports and a 4-cm utility incision without rib spreading. Every type of lobectomy was performed. Conversion (switch from the robotic to an open-thoracotomy approach) rate was 12% (4/34), median number of lymph node stations removed was four (2–7) and operative mortality was 0%. Morbidity rate was 26% and median chest tube duration was three (2–12) days. The median operative time was 218 (155–350) minutes. At the time of this study, the authors concluded that the utility and advantages of robotic assistance for video-assisted thoracic surgical lobectomy required further refinement and study of the technique.

In 2006, the robotic system went though a major evolution. The entire system was re-vamped with a new computer system as well as high definition camera. The instrument arm had new mechanics as well as made smaller and more efficient movements. A fourth arm was completely integrated into the system. Gharagozloo et al. developed a standardized hybrid robotic-thoracoscopic approach for pulmonary lobectomy and reported on their first 100 consecutive patients (NSCLC stage I and II) in 2009.⁸ The robot was used for lymph node dissection, hilar dissection and dissection of the oblique fissure. Control of vascular and bronchial structures, however, was exclusively performed by the tableside surgeon with conventional staplers. Conversion rate was 1% and mean operative time was 216 minutes. Complication rate was 21% and operative mortality was 3% in this series.

Also in 2009, the group around Melfi in Milan, Italy, reported on a series of 54 patients in whom lung lobectomy was performed with the new-generation four-arm da Vinci robot for early-stage lung cancer.⁹ Again, vascular and bronchial control was performed using standard endoscopic staplers. Standard mediastinal lymph node dissection was performed subsequently. Conversion rate was 13%, postoperative complication rate 20% and median number of lymph nodes removed was 17.5. Median robotic operating time decreased by 43 minutes (P = 0.02) from first third (18 patients) to the last two-thirds (36 patients). Hospital stay was 4.5 days and significantly shorter than in a matched group of patients after open operations.

In 2009, the current 3rd generation robotic system as introduced. It added more technological advances of miniaturization. The instruments were now 5mm in diameter and the robotic mechanics were further reduced in size and made more efficient. In October 2011, Cefiolio and colleagues reported propensity match series (1:3 patients) of 106 consecutive patients that underwent a robotic lobectomy vs. 318 patients with minimal invasive thorocotomy lobectomy. The robotically operaterated patients had less blood loss (30 vs. 90ml), less chest tube time (1.5 vs. 3 days), shorter hospital stay (two vs. four days), less post-operative complications (27 vs. 38%). The operative time was significantly longer (2.2 vs. 1.5) hours. The conversion rate was 1% to open surgery.¹⁰ The amount of lymph nodes was the same. This single center, single surgeon series shows that robotic lobectomy patient can have a very short hospital stay and fewer complications.

Published in 2012, an international study including three major medical centers showed excellent long-term cancer results using robotic systems.¹¹ 325 patients underwent robotic lobectomy for primary NSCLC. The mean operative time was 3.5 hours. There were no intraoperative deaths. The conversion rate was 8%. Post-operative complications were 25%. The length of stay was five days. The overall survival was 80% at five years. Survival for stage 1A was 91%, stage 1B was 88%, and stage II was 49%. Three year survival was 43% for stage IIIA. These survival rates are consistent with the largest VATS series.

Conclusion

Robot technology is rapidly expanding; there are 1450 centers that currently have at least one robotic system. But the robotic systems are in their infancy as far as technology advancements and potential. Just over the last five years, the systems have become significantly smaller and more efficient in their instrumentation. There is no question, that these systems allow surgeries that once required large, extensive incisions for surgeon exposure to be performed using significantly less trauma to the patient. In pulmonary lobectomy, however, meticulous dissections of fragile structures (pulmonary artery, veins, airways, lymph nodes) are the main surgical steps where the tremor filtration and motion scaling can play a big part.

In the area of lung cancer, VATS technology has proven to be safe and better than open lung surgery. At this time, robotic lobectomy has not proven to be better than VATS lobectomy. Robotic technology has the potential to help the 50–70% of thoracic surgeons who do not perform VATS lobectomies, the opportunity to use this technology to give their patient a less invasive operation. Clearly, the recent studies have shown that it is possible to have patients discharged 1 day after robotic lobectomy. The hope would be to offer the cancer patient a minimally invasive surgery before resorting to a thoractomy.

Robotic surgery will continue to make technologic advances, as does any technology and many of the advances will likely transcend into hand held instruments. Lung cancer surgeries can be performed using robotic technology in a safe and minimal invasive fashion giving patient the same results as open surgery without the more extensive incisions.

Biography

Sunil M. Prasad, MD, is as Assistant Professor of Surgery in the Division of Cardiothoracic Surgery at Washington University School of Medicine in St. Louis.

Contact: spradad@wustl.edu