Evaluation of Various Port Positions for Minimal Access Cardiovascular and Thoracic Procedures

Background: Video-assisted thoracoscopic surgery (VATS) is used to diagnose or treat diseases of the chest. Most of those procedures traditionally performed with open thoracotomy can be done using smaller incisions with video assistance. Robot-assisted thoracic surgery (RATS) is a technologically upgraded system that uses computers to help surgeons for precise tremor-less instrument control in a confined space with utmost accuracy. For access to the chest minimally, two principles are followed: the baseball diamond principle (BDP) and the triangle target principle (TTP) of port position. Both can be used for minimal access cardiovascular and thoracic surgery. Different manipulation angles (30°, 60°, and 90°) are used to perform the task and find out time, errors, and surgeon’s discomfort during the surgery. Objectives: To evaluate and compare task performance at different port positions during minimal access cardiovascular and thoracic procedures in a swine. Materials and methods: A prospective experimental animal study was granted and conducted at the World Laparoscopy Hospital, Gurugram, Delhi, India. Three thoracic and two cardiac procedures were selected for this study conducted on 30 swines over 11 months from January 15, 2018, to November 15, 2018. At the end, euthanasia was conducted humanly and carcasses disposed appropriately as per the regulation under the provisions of the Prevention of Cruelty to Animals Act, 1960, and the Acts of 1998 and 2001. Results: A total of 30 procedures were conducted in this study using TTP of port placement. The procedures are lung resection-6, thymectomy-6, closure of atrial septal defect (ASD)-6, internal mammary artery (IMA) harvesting for totally endoscopic coronary artery grafting (TECABG)-6, and esophagectomy-6. It is to evaluate the execution time (sum of the ports access time and the actual procedure time), error rates, and the surgeon’s discomfort for each of the three angles of manipulation. Average timing of all tasks was shorter with 60° manipulation and all were reproducible. All the tasks were difficult at 30° and 90° angle. Closer manipulation of angle to 90° and above takes longer operative time. It may be due to fatigue from shoulder overstretching for increased elevation angle. It was demonstrated that the surgeon’s discomfort level was least at the 60° port position. Conclusion: There is no fixed position for port placement in the cardiovascular and thoracic procedures. The average timing of all tasks was shorter, there were less errors, and surgeon’s discomfort was less operating at 60° manipulation angle. Readings of timing obtained while taking a suturing and tying surgeon’s knot in lung resection on swine at different manipulation 60°, 90°) were validated and average obtained by χ 2 tests. All the readings were reproducible at a p value of 30.144 at 5% level of significance. It was demonstrated that the 60° angle had shorter operative time followed by 30° and then 90°. 60° angle operative time followed by 30° then 90°.