VIDEO ASSISTED THORACOSCOPIC SURGERY FOR EARLY STAGE LUNG CANCER
What is Video Assisted Thoracoscopic Surgery?
Video Assisted Thoracoscopic Surgery (VATS) is a minimally invasive chest surgery performed with videoscope monitor vision through small keyholes and without conventional open thoracotomy. Although simple thoracoscopy to examine the pleural space and perform simple wedge resection has been practiced for a long time, advanced thoracoscopic techniques for anatomic lung resection began in the early 1990’s. In recent times there have been several technological advances in laparoscopic and thoracoscopic equipment & surgical instruments. VATS is slowly becoming the gold standard for surgery for thoracic cancers. Although there may be a surgeon preference in technique, mostly the same surgical & oncological principles are applied to thoracoscopic resection as with conventional open surgery; i.e. complete surgical resection with negative margins and mediastinal & hilar lymph node dissection.
Advantages of Video Assisted Thoracoscopic Surgery
Just as laparoscopic abdominal and pelvic surgery has almost replaced open abdominal surgery, similarly minimally invasive thoracoscopic surgery is gradually becoming an alternative to open thoracotomy for lung, esophagus and mediastinal tumors. This way radical resections are performed through keyhole approach avoiding opening of the chest with big incisions. The main advantage is less postoperative pain, quick recovery, shorter hospital stay and improved shoulder function. There is improved pulmonary function and less chance of chest complications compared to open thoracotomy. Operative outcomes such as blood loss, total operative time and peri-operative complications all favour minimal invasive approaches. Moreover improved patient recovery facilitates early delivery of adjuvant chemotherapy. Although several small studies have shown similar oncologic outcomes comparing open thoracotomy and VATS in early stage lung cancer, in terms of adequacy of surgery and long term survival. A recent meta-analysis of twenty studies with over three thousand patients comparing VATS and open thoracotomy showed distinct advantage in intra-operative blood loss, chest drain time, hospital stay and overall complication rates with VATS. Five year survival rate was significantly higher with VATS than with thoracotomy. Overall VATS therefore achieves better surgical and oncologic outcome and is a preferred surgical approach for early stage lung cancer.
Indications & Contraindications of Video Assisted Thoracoscopic Surgery
The most common indication of VATS is thoracoscopic wedge resection of pulmonary metastases; most commonly from bone & soft tissue sarcomas and limited metastases from other malignancies such as carcinoma breast, colorectal, and genitourinary tract cancers (Figure 1). Solitary Pulmonary Nodules (SPN) suspicious for malignancy on imaging (PET / CT Scan) or positive for malignancy on histology are also best suited for VAT wedge resection for confirmation of diagnosis or lobectomy as a curative option (Figure 2). The most important indication of VATS is surgery for early lung cancer i.e. lobectomy with systematic mediastinal & hilar lymph node dissection.
Most suitable cases for VATS lobectomy are small 5-6cm size tumors, peripherally placed without any endobronchial lesions and without pleural adhesion, chest wall invasion or fixed mediastinal lymph nodes.
Contraindications include locally advanced lung cancer with fixed peribronchial or hilar lymph nodes and use of preoperative chemotherapy or radiotherapy. Prior thoracotomy, advancing age, presence of emphysema and other co morbidities is not a contraindication to VATS lobectomy. In fact patients with larger BMI, older age and higher ASA benefit from VATS more than with thoracotomy.
Technique of VATS
Patient is placed in full lateral decubitus position with flexion of the table at the level of the hip and the table bent down so that the patient’s chest is parallel to floor (Figure 3). This allows for splaying of ribs and widens the intercostal space to improve thoracoscopic access and vision. Single lung anesthesia is established using a double lumen endobronchial tube. Commonly three or four ports are used (Figure 4). A 30ᵒ HD thoracoscope is used as it gives a panoramic view of the surgical field with minimal clash of instruments. Dedicated thorascopic instruments with extra long length with fulcrum at the port site are used for dissection. Articulating straight staplers are used for controlling vessels, bronchus and dividing fissure. Subsequent surgical steps of VATS lobectomy are almost similar to conventional open surgery and may vary depending on patient anatomy, tumor size and surgeon preference (Figure 5).
Robotic Surgery – Present and Future of Thoracic Surgery
Robotic Surgery is actually robot assisted minimal invasive surgery, where instead of directly moving surgical instruments the surgeon manipulates instruments through computer control on a surgeon console (Figure 6). The last 5-10 years have seen a rapid evolution in minimal access surgery with a transition from laparoscopic or thoracoscopic surgery to wide spread use of surgical robotic system. Besides 10X magnification and 3D binocular vision, the da Vinci ® surgical robot system offers seven degrees of endowrist movement and a stable platform for the operating surgeon compared to laparoscopic or thoracoscopic surgery using the straight stick like instruments.
Patient who are eligible for VATS lung resection would also be suitable for robot assisted surgery. Patient positioning and anesthesia is similar to conventional VATS arrangement. Standard technique includes use of a camera port, three instrument ports and a utility incision for application of staplers and tissue retrieval (Figure 7).
Several institutional studies have shown that robot assisted surgery is feasible and safe. The results of morbidity and mortality are similar to VATS lobectomy. Patient benefits with shorter hospital stay, less pain and early return to normal activity. Upstaging of stage I lung cancers is relatively higher with robot assisted surgery compared to VATS and open surgery due to more meticulous mediastinal lymph node dissection.
The main advantage of robotic surgery is that in addition to minimally invasive approach, there is additional 4 degrees of endowrist instrument movement, 3D magnified view to operating surgeon, elimination of fulcrum effect and reduced human tremor and improved ergonomic position for the operating surgeon and shorter learning curve.
To conclude minimal invasive thoracoscopic surgery is more favorable than conventional open thoracotomy for surgery with quick post operative recovery, shorter hospital stay, lower complication rates and better 5 year survival outcomes.