Robotic versus laparoscopic surgery for colorectal cancer: a case-control study

Surgical resection is still the main treatment modality for resectable colorectal cancer. Advances in surgery have allowed the widespread use of minimally invasive surgical techniques, which are represented by laparoscopic and robotic approaches as opposed to open approach.

Laparoscopic colorectal resections (LCR) are safe and offer patients better short-term results as open surgery with less postoperative pain, faster recovery, shorter hospitalization and better cosmesis. Furthermore, they are oncologically equivalent to open surgery, as evidenced by multiple randomized studies.1,2,3 There is even some evidence that LCR result in better median overall survival for patients with stage II colon cancer, older than 75 years, when compared to open surgery.4

Robotic surgical systems were designed to overcome the limitations of laparoscopic surgery, offering better visualization with three-dimensional magnified view and stable camera platform, stabilization of tremors and greater dexterity of movements. Moreover, they also improve the ergonomics, possibly reducing fatigue of the operating surgeon.5 Key drawbacks include loss of haptic control, longer operative time and above all, increased financial costs.

Shortly after the introduction of robotic platforms, surgeons have begun to utilize robotic surgery for management of colorectal diseases and the number of procedures performed annually has steadily increased.6 The evolution and usage of robotic platform is well illustrated by bibliometric data, as more and more manuscripts are being published each year, from feasibility studies to case series and reviews, and, finally, more and more multi-centre trials. The abundance of published research clearly shows, how robotic assisted surgery has gained acceptance not only in the field of colorectal surgery, but across many surgical specialities.7 However, most of the studies have not demonstrated a major advantage of robotic colorectal resections (RCR) in comparison to laparoscopic resections.8 Some studies have shown a benefit of the robotic approach with fewer conversions.9 The ROLARR study has also shown this for the difficult rectal resections involving obese men with low rectal cancers.10

To evaluate the implementation of robotic platform at a tertiary medical centre we designed a retrospective case-control study to compare outcomes of patients who underwent elective laparoscopic or robotic colorectal resections.

There was no statistically significant association between demographic variables, concomitant diseases, the severity of disease and the type of the operation (Table 1). Patient characteristics did not differ significantly between groups as there was no statistically significant association between demographic variables, concomitant diseases, and severity of disease and the type of the operation.

Associations between several variables of the performed operation, patient course of recovery after the operation, procedure (type of resection) and the type of the operation performed (laparoscopic or robotic) were analysed by univariate logistic regression and results are presented in Table 2. Operative time was statistically significantly longer (p < 0.001) in robotic group. Five (13.5%) patients had operation conversion within the laparoscopic group, while there were no conversions to open surgery in the robotic group of patients (p = 0.004). While the groups were comparable regarding the duration of hospitalization (p = 0.168) and the number of harvested lymph nodes (p = 0.240), the transfusion was to higher extent given to patients in laparoscopic group of patients (p = 0.004). Five (13.5%) patients within laparoscopic group needed transfusion, while there were no patients in need of transfusion within the robotic group of patients. The groups were comparable both with regards to overall complications (p = 0.576) as well as to type of complications according to the CD classification (p = 0.12). Reoperation was performed in three (8.1%) patients from the laparoscopic and none of the patients within the robotic group of patients (p = 0.026).

This analysis of minimally invasive colorectal resections is, to the best of our knowledge, the first comparison of robotic versus laparoscopic resections for colon and upper rectal cancer in Slovenia. Safety of our patients and quality of surgical care was of outmost importance when we implemented a new robotic abdominal program. Hence, treatment results were not to be compromised. Consequently, only patients with colon and upper rectal cancer were operated at first, because we deemed middle and low rectal cancers not suitable at the beginning of the new program, due to technical demands of pelvic surgery.

Many studies, comparing RCR and LCR, have shown the new technology to be safe, feasible and at least equivalent with respect to short-term outcomes and oncological results.17 The most relevant finding of our study were significantly lower rates of conversion to open with the robotic platform compared to LCR (p = 0.004), which is consistent with findings of other studies.18 Only slightly shorter hospital length of stay was seen in robotic group, the difference not reaching statistical significance (p = 0.168). Some studies agree with our findings, others, on the other hand, demonstrate clinically significant shorter length of stay associated with robotic colorectal resections.19, 20, 21 In our study, there were three cases of anastomotic leakage in laparoscopic group. All three patients had to be reoperated, one of them died due to the septic shock. In the robotic group, there was no anastomotic leakage, however, one patient died because of acute thrombosis of superior mesenteric artery and coeliac axis. It is reasonable to assume that our study was underpowered to detect differences in postoperative morbidity, either overall or specific complications. However, other studies also demonstrate inconsistencies when comparing laparoscopic and robotic complication rates. Halabi et al., in their analysis argue, that there is no difference in postoperative morbidity between LCR and RCR.22 On the other hand, there are studies, showing better results in ter ms of postoperative morbidity and mortality for either laparoscopic or robotic colorectal resections.23, 24 Nevertheless, some reports in literature show variable differences in complication rates, i.e., more anastomotic complications in one group and more general postoperative morbidity in the other.20

Another limitation of our study is its retrospective observational nature with all the inherent biases. Important issue to be addressed are the operative costs, which is one of the biggest criticisms of robotic surgery and has been a subject of discussion since its introduction. Our database does not include the cost data, so we did not address this issue in our study. Also, the intention of study being primarily the safety and oncologic equivalency of our new robotic surgical program, we did not assess the quality of life of operated patients. This, together with comprehensive cost analysis as well as long-term oncological results represents a very good potential for future studies.

The strength of our study is that the operations were performed by only two surgeons that reduces the heterogeneity of surgical techniques. Both surgeons had years of experience in laparoscopic surgery for all the patients included in the study and it can be assumed that they were already on top of their learning curve in laparoscopic surgery. This probably also played a role in faster acquisition of skills on the robotic platform. However, since the included robotic operations represent the start of our robotic program, there may still be room for improvement. It has been shown that the operating time decreases with the number of cases and this could have impacted the results of our study as well.25, 26

With this study, we sought to offer an outcome-based assessment of implemented robotic colorectal program at our academic institution. Based on the results, it is appropriate to conclude, that our program is safe, has equivalent postoperative results compared to classic laparoscopy and is even associated with decreased conversion rates.