Robotic Cholecystectomy Using the Chinese Micro Hand S Robot: A Controlled, Randomized, Prospective Clinical Study

Objective: To determine whether the newly developed Chinese Micro Hand S surgical robot results in non-inferiority outcomes in cholecystectomy compared with the prevalent da Vinci robot.

Design: A single-blinded, prospective randomized parallel controlled clinical trial was designed and conducted from December 2019 to November 2020. The study was conducted in an academic hospital. 82 patients with a gallstone, gallbladder polyp and other benign gallbladder diseases were enrolled in this study. Finally, 82 patients were randomly divided into the Micro Hand S surgical robot group and the da Vinci surgical robot group.

Interventions: Standard robot-assisted transabdominal cholecystectomy was conducted using the Micro Hand S robot or the da Vinci robot.

Main outcomes and measures: The main outcome was the success rate of operation. Surgical success was defined as that the surgical procedures were completed by the experimental or control product without transferring to non-robotic surgery. Secondary outcomes included assembly time, operation time, intraoperative hemorrhage, time to first flatus, postoperative pain, comprehensive complication index, resident time and patient satisfaction.

Background:

Cholecystectomy is one of the most common operations in general surgery, with about half a million patients getting cholecystectomy each year in the United States. In the 1990s, minimally invasive surgery (MIS), as a new technology, greatly improved the traditional open abdominal surgery, of which defects are known as the big wound and long time to recover. Today, nearly 90% of cholecystectomy are performed laparoscopically. Previous studies have shown that laparoscopic cholecystectomy may reduce postoperative pain, shorten the hospital stay, and save the overall cost in hospital, which has become the standard operation for the treatment of gallbladder disease. In recent years, robot-assisted laparoscopic surgery has become more and more widely used in general surgery because of its advantages of 3D visions, high magnification, tremor suppression, and precise manipulation. According to a reported retrospective study, the da Vinci robot-assisted cholecystectomy showed excellent operation security, which can achieve the same therapeutic effect as the conventional laparoscopic cholecystectomy. But studies also reported that the increased cost may be the main problem of the da Vinci robot-assisted cholecystectomy.

The Micro Hand S surgical robot is a new generation of Chinese independently developed surgical robot system. Apart from the flexibility and intelligence in operation manipulation, the Micro Hand S surgical robot also has the advantages of small size, portable equipment, low maintenance costs and outstanding equipment compatibility. After initial preclinical trials, the Micro Hand S surgical robot has been successfully applied in clinic, and proved security and feasibility in various gastrointestinal surgery.

Since 2019, investigators in this group have designed and taken up research to assist laparoscopic cholecystectomy with the Micro Hand S surgical robot, which is noted as a prospective, randomized, single-blind, and parallel controlled clinical trial. The primary purpose of this study is to determine whether the newly developed Chinese Micro Hand S surgical robot results in non-inferiority outcomes in cholecystectomy compared with the prevalent da Vinci robot.

Method:

The study was designed as a single-blind prospective randomized clinical trial since it is inevitable for the surgeon to know what kind of robot to use during the operation. After obtaining the approval of the Ethics Review Committee and other relevant institutions of the Affiliated Hospital of Qingdao University, a total of 82 patients were included in this study from December 2019 to November 2020. Finally, 82 patients were randomly divided into the Micro Hand S robot group and the da Vinci robot group. All enrolled patients were fully informed and signed the informed consent. Patients were randomly assigned to each group in a 1:1 ratio, and information of the grouping and intervention measures were not available to patients. Patients of each group were matched for age, sex, body mass index (BMI), and complications to reduce confounding intervention factors.

Surgical procedure:

The patient was placed in the supine position after general anesthesia. The Veress needle was inserted at 2cm below the umbilicus (point A) to establish the CO2 artificial pneumoperitoneum. A 12mm trocar was inserted into the abdominal cavity and the pneumoperitoneum tube was connected to the trocar. The intra-abdominal pressure was set at 11-13mmHg, and then the preheated three-dimensional laparoscope and cold-light source were placed into the abdominal cavity through the trocar. Then a thorough examination was taken on the intended trocar points and the surgical area. After adjusting the patient with a Trendelenburg position inclined to the left, 10.5mm magnetic trocars were respectively placed at 2-3cm medial side of the right anterior axillary line, 8-10cm below the costal margin (point B); and 2-3cm below the costal margin of the left mid-clavicular line (point C); and were connected to the robotic arms No. 1 and 2. Besides, a 10mm trocar were placed at point D (lateral inferior of the line connecting point A and C) as the auxiliary channel. The surgeon held the neck of the gallbladder or Hartmann's Pouch with bipolar forceps, and pulled the neck to the right upper to open the serosal layer of the cystic duct. The cystic duct and the cystic artery were then separated by blunt dissection so as to distinguish the common bile duct, hepatic common bile duct, and cystic duct. Clamp and cut off the cystic duct near the gallbladder's neck with a Hemo-lock clamp. The cystic artery was found medial posterior side of the cystic duct. Clamp and cut off the cystic artery with Hemo-lock clamp. Pull the gallbladder's neck upward and remove the gallbladder by anterograde resection with an ultrasonic knife. The assistant assisted in dragging the gallbladder and the liver bed to keep a certain tension. The intact gallbladder was put into the specimen bag and removed. Bleeding and bile leakage was carefully checked, and the gallbladder bed was coagulated. The operating instruments were withdrawn from the patient's abdominal cavity after checking the instruments and the gauze. The pneumoperitoneum was exsufflated and the incisions were closed.

During the operation, the assembly time, intraoperative blood loss, operation time, operation success rate, and the adjacent organ and vascular injury caused by the failure of the tested system were recorded. Pain score was analyzed 24±2 hours after the surgery. The vital signs (temperature, pulse, respiration, blood pressure) were measured on the 3rd day postoperatively. Meanwhile, the routine blood test (red blood cells, white blood cells and neutrophils, platelet, hemoglobin), liver and renal function (ALT, AST, TP, ALB, GLU, TBIL, BUN, and CREA), the electrolyte (K, Na, Cl, Ca), blood sugar, and color ultrasound of liver, gallbladder, pancreas and spleen were checked. Operating surgeons filled in the satisfaction questionnaire postoperatively. Furthermore, the patients' postoperative condition changes, postoperative medication, the first postoperative anal exhaust, postoperative complications, and resident time were also recorded. All the patients were followed up by telephone at 30±5 days postoperatively to evaluate the incidncee of adverse events.