The present study reports results from robotic-assisted sleeve gastrectomy with the Senhance™ surgical system in 20 obese patients. The aim was to evaluate the feasibility and safety of the new Senhance™ surgical system in obese patients.
Unlike other systems, the advantages of the new Senhance™ surgical system include tactile force feedback, separately placeable arms, individually and repeatedly adjustable pivot points of the trocars to minimize both resistance and tissue trauma, reusable instruments and a stable three-dimensional camera with eye-tracking .
Especially in obese patients, the limited intraabdominal space and the large leverage due to the thick abdominal wall are limiting factors for minimally invasive surgery. Robotic-assisted surgery could overcome these limitations and its better surgical control and estimation could ultimately optimize surgical procedures. Zhang and colleagues even found lower mortality within 90 days (Odds Ratio: 2.40; 95% CI (1.24–4.64); p-value = 0.009) for robotic-assisted surgery compared with laparoscopic bariatric surgery .
The Senhance™ surgical system uses 5 mm instruments as a standard size. With this instrument size, high bending forces on the instruments were observed in some obese patients in the present study. Together with the tactile feedback, these forces made repeated recalibration of the pivot point necessary. However, conversion due to too large leverage forces on the instruments and insufficient intraabdominal space was only necessary in one case. In this case, the procedure was completed by using 10 mm instruments and the conversion to standard laparoscopy was performed without a significantly longer operating time. This problem could possibly be addressed with the development of more rigid instruments. The patient for this conversion was male, characterized by a BMI of 44.9 kg/m2 and a height of 187cm. Noteworthy, he was the tallest but not the most obese in the overall study population. Accordingly, perioperative complications and conversions cannot be generalized to be caused by severe obesity. Of note, when the Senhance™ surgical system was first introduced to the European markets, its CE conform application was restricted to a maximum BMI (40 kg/m2). By April 2021, this limit was repealed, allowing its use even in severely obese patients with CE conformity. Overall, physical condition and proportion should be carefully evaluated and discussed for robotic-assisted surgery in each case.
The patient selection for the present study was performed according to the criteria for standard laparoscopic sleeve gastrectomy to avoid selection bias. Therefore, patients with previous abdominal surgery were also included. The study results show that 40% of the patients had undergone previous surgery, but the two recorded conversions to laparoscopic surgery were due to bleeding and limited motion. In conclusion, previous abdominal surgery cannot be considered a contraindication for robotic-assisted bariatric surgery, as for example also robotic-assisted revisional procedures are feasible .
Regarding the surgical technique, Senhance™ surgical system is based on laparoscopy. Together with the free placement of the robotic arms, surgical technique (e.g. trocar placement) is comparable to the laparoscopy standard and no adjustments are necessary. This allowed for a rapid adaptation of the system by the laparoscopically experienced surgeons. In the case of conversion to conventional laparoscopy, a smooth and quick conversion without the need to place new trocars was accomplished. This represents a safety advantage of the Senhance™ surgical system, especially in the event of a bleeding complication.
A recent meta-analysis stated longer operating times in robotic-assisted than in standard laparoscopic sleeve gastrectomy (mean operating time: laparoscopic sleeve gastrectomy: 84.18 to 138 min; robotic-assisted surgery: 95.5 to 148) . In contrast, data from the present study with Senhance™ surgical system lies within comparable times reported for laparoscopic sleeve gastrectomy. This could be because the docking time of the Senhance surgical system is relatively short compared to other systems. With the increasing experience of the team, operating time could be even further reduced . The console time, as well as the total operating time, showed a fast reduction to times more similar to that of laparoscopy. Important to emphasize is that the performing surgeons in the present study are well experienced in the field of laparoscopic surgery, while they only performed less than ten robotic-assisted procedures before the time of the study. Taken together, the finding indicates that the learning curve of the laparoscopy-based system is reduced for experienced surgeons. Present findings of hospitalization days (1.7 ± 1.8 to 4 ± 3 days) , postoperative complications (2.9 %) , and 30-day readmission rates (7.1%)  with the Senhance™ surgical system are comparable to other published robotic-assisted and standard laparoscopic sleeve gastrectomy results.