Traditional thoracic surgery involved large incisions in order to adequately expose the relevant chest cavity and visualize the target organ.
For example, heart surgery, such as for coronary artery bypass grafting or cardiac valve surgery, or resection of mediastinal masses, such as thymectomies for thymomas, traditionally required a full sternotomy incision in order to adequately expose the pericardial cavity or the mediastinum, respectively, and to visualize the heart or the involved mediastinal structure, such as the thymus, respectively.
Similarly, lung surgery, such as for lung cancer, traditionally required a large thoracotomy incision in order to expose the involved pleural cavity and to visualize the involved lung.
These thoracotomy incisions usually involved division of both the latissimus dorsi and the serratus anterior muscles and often resection of the entire 5th rib to achieve this exposure.
Although the cut edges of the latissimus dorsi and the serratus anterior muscles would subsequently be reapproximated with sutures, these muscles would never regain their original strength due to denervation of the distal half of each of these muscles.
For esophageal surgery, the traditional incisions required both a large abdominal incision to expose and mobilize the stomach and a large thoracotomy incision to expose and resect the esophagus and to construct the gastric conduit.
However, these large incisions are associated with significant morbidity, such as increased intraoperative bleeding, increased risk of infection, increased postoperative pain, increased narcotic-associated complications, longer hospital stays, and longer recovery periods.
In attempts to decrease these postoperative sequelae, approaches that utilized smaller incisions and that spared previously divided muscles were developed. Partial sternotomy techniques were developed for cardiac and for mediastinal surgery.
Muscle-sparing thoracotomy techniques were developed, in which one or both of the latissimus and the serratus muscles were not divided and in which the 5th rib was not resected.
In contrast to traditional thoracotomies, muscle-sparing approaches resulted in the patient eventually regaining full muscle strength, but these still relatively large incisions still resulted in significant postoperative pain and morbidity and in prolonged hospital stays and recovery periods.
In addition, these smaller incisions, while still relatively large, decreased exposure of the relevant body cavity and visualization of the target organ during surgery.
With the development of video technology in order to improve visualization within the relevant body cavities and of target organs, surgical incisions were able to be further minimized in order to decrease postoperative sequelae even more.
Initial success with minimally invasive pelvic and abdominal surgery, such as with laparoscopic hysterectomies in gynecology and with laparoscopic cholecystectomies in general surgery, respectively, were then translated to video-assisted thoracoscopic (VATS) procedures, including lung resections, esophageal resections, mediastinal resections, such as VATS thymectomies, and even many cardiac procedures, such as VATS mitral valve repair or replacement.
Minimally invasive VATS surgical procedures have well-established advantages over traditional open thoracic surgery via thoracotomy, including less intraoperative bleeding, less need for perioperative blood transfusions, smaller surgical incisions, less postoperative pain, less need for postoperative narcotics, reduced exposure of internal organs, less perioperative inflammatory response, shorter hospital stays, shorter recovery times, faster return to routine activities of daily living, reduced infection risk, and less postoperative scarring.
Long narrow surgical instruments were developed in order to be able to reach the farthest recesses of the relevant body cavities through these small “keyhole” incisions, but use of these straight non-articulating instruments was akin to operating with chopsticks.
While a few instruments with articulating tips have been designed, articulation often required complicated controls, such as wheels and levers to realize the articulation.
Moreover, use of these instruments was counter intuitive, as need to move the working internal end of the instrument in one direction required that the surgeon move the external handle of the instrument in the opposite direction.
For example, to move the working internal end of the instrument up, surgeons must move their hands down, and to move the working internal end to the left, surgeons must move their hands to the right.
These shortcomings in surgical instruments has limited the widespread adoption of VATS surgery, with less than 45% of all lobectomies in the United States being performed by VATS approach despite almost 20 years since the first VATS lobectomy in 1991 and with 80% of VATS lobectomies being performed at specialized academic centers.1,2,3
Addition of a robotic surgical system (da Vinci®, Intuitive Surgical Corporation, Sunnyvale, California) (Figure 1) to VATS surgical procedures corrects several of the shortcomings of VATS cameras and instruments.
First, at the surgeon console (Figure 2), the robotic system’s binocular cameras (Figure 3A) provide the surgeon with a high-definition, 3-dimensional view of the operating field, which provides improved depth of perception compared to the 2-dimensional image provided by conventional VATS cameras.
Second, the robotic system computer translates the surgeons hand movements at the surgeon console (Figure 3B) to equivalent movements of the robotic surgical instrument working tips within the patient, which is contrary to the popular misconception that the robot itself performs the surgery. The surgeon simply manipulates the hand controls within the surgeon console as he or she would control surgical instruments during a traditional open surgical procedure via a full sternotomy or thoracotomy incision.
When the surgeon needs to move robotic instrument working tips up, the surgeon moves the controls up, and when the surgeon needs to move the robotic instrument tips to the left, the surgeon moves the controls to the left. Moreover, the robotic system has the capacity to scale down the surgeon’s hand movements and to reduce any hand-related tremors (Figure 4).
Third, the articulating robotic instrument working tips has the same or more degrees of motion than the human hand (Figure 5) and improves the ability of the surgeon to complete surgical procedures that require operating around and behind structures, such as around the pulmonary artery and vein and around the bronchus within the pulmonary hilum during a lung resection, and within deep narrow spaces, such as within the mediastinum during mediastinal lymph node dissection.
For minimally invasive thoracic procedures, such as VATS lobectomies or esophagectomies, these advancements in instrumentation allows for more precise hilar dissection and less risk of intraoperative complications and less risk of conversion to open lung or esophageal resection via a large thoracotomy, in which case the patient loses the benefit of minimally invasive surgery.
Thus, robotic-assisted surgery would allow minimally invasive surgical procedures to be within reach of more thoracic surgeons, especially those who are currently performing mainly open thoracic surgical procedures, and to be available to more patients who would benefit from the advantages of VATS surgery.
For oncologic procedures, robotic-assisted thoracic surgery improves mediastinal lymph node dissection and improves detection of mediastinal lymph node metastases,4 which translates to patients with clinically occult pathologic stage-2 or stage-3 disease being able to be offered the necessary adjuvant chemotherapy or adjuvant chemotherapy with radiation therapy, respectively, and which in turn would be expected to improve cancer-related patient survival rates.
After all, are not improved postoperative outcomes and improved survival rates our ultimate goals for our cancer patients?
By Eric M. Toloza, M.D., Ph.D., F.A.C.S., F.C.C.P.