In this report of our initial outcomes with robotically assisted cytoreductive surgery with HIPEC, we show that these procedures are feasible and safe in selected patients with low PCI scores in centers with prior experience with robotic oncological surgeries. Localized disease can be effectively cytoreduced from the upper and lower abdomen using the robotic platform and enhanced postoperative recovery with minimal or no morbidity can be achieved.
Minimally invasive oncological surgery is associated with distinct benefits over open surgery. Decreased blood loss, less opiate usage, faster return of bowel function, and shorter hospitalizations have been shown for gastrointestinal cancers[1, 5, 6]. Our report mirrors these findings with estimated blood loss < 50ml, return of bowel function on postoperative day 3 and short hospitalizations without any major morbidity. Additionally, minimally invasive surgery minimizes the risk of wound morbidity which can become a major problem after CRS/HIPEC especially for the morbidly obese patients.
The existing literature on minimally invasive CRS/HIPEC reflects mostly the laparoscopic approach. Arjona-Sanchez et al in one of the largest reported series of 143 patients who underwent laparoscopic CRS/HIPEC (55% harbored pseudomyxoma peritonei) reported excellent short and long term outcomes[3]. In their series the median PCI was 3, length of stay 6 days, 30 day major morbidity and mortality rates were 8.3% and 0.7% respectively, whereas at a median follow up of 37 months, 88.2% of patients remained free of disease. This series involved centers with experience of at least 30 CRS/HIPEC procedures a year. Small case series utilizing robotic CRS/HIPEC have started to emerge showing similar postoperative outcomes with the laparoscopic approach, in patients with limited PCI scores[4, 7]. It is important to emphasize that these reports come from centers with experience in minimally invasive oncologic surgery and open CRS/HIPEC both of which are prerequisites to perform safely minimally invasive CRS/HIPEC.
Operating in multiple quadrants can be challenging for laparoscopic surgery. Robotic assisted technology with the ease of redocking and working on separate quadrants at the time has solved this problem by making minimally invasive surgeries feasible for disease located in multiple quadrants. Multi-quadrant robotic surgery for extensive operations such as pelvic exenteration and multivisceral robotic liver surgery is feasible[8, 9]. Similar approaches can be achieved in peritoneal cancers for disease located in multiple quadrants as we show in this report. It is the volume of disease in each quadrant rather than how many quadrants are involved which determines if it can be resected robotically. Another technical advantage of minimally invasive surgery is associated with the formation of less postoperative adhesions[10] which can prove especially beneficial for peritoneal malignancies if repeat CRS/HIPEC is needed. It is well established that iterative CRS/HIPEC is associated with survival prolongation in patients with favorable biology[11].
The efficacy of CRS/HIPEC for low grade mucinous neoplasms of the appendix is widely accepted[2]. The benefit for gastric cancer continues to be a matter of debate, however there is a body of accumulating data showing promising outcomes especially for patients with only positive peritoneal cytology or low volume peritoneal disease[12, 13]. Similar skepticism exists for use of HIPEC for colorectal cancer after the negative results of oxaliplatin based HIPEC for colorectal cancer in the Prodige 7 trial[14]. More data is needed. The main drawback against CRS/HIPEC for cancers such as gastric and colorectal is the morbidity associated with these operations. For example in the prodige 7 trial grade-3 morbidity was increased in the HIPEC arm (26% vs. 15%; p = 0.035)[14]. However, given that a significant proportion of gastric and colorectal peritoneal cancers have low PCI the implementation of RCRS/HIPEC can potentially mitigate this morbidity and thus make feasible the conduction of more randomized trials. PCI < 10 has been associated with significantly improved outcomes of cytoreductive surgery for colorectal cancer with peritoneal dissemination(15).
We recognize that this report has important limitations. Main one being that these are highly selected patients with low peritoneal carcinomatosis index. Even though the robot allows access in all quadrants of the abdomen, the vast majority of patients with peritoneal disease have extensive disease that cannot be effectively cytoreduced in a minimally invasive way.