Robotic gastrectomy: Is it better?

Here is yet another paper, this time from Archives of Surgery, extolling the virtues of robotic surgery. Thus time the subject is gastrectomy for cancer. Surgeons in Korea retrospectively looked at 827 gastrectomies for cancer; 591 of which were done with standard laparoscopic technique and 236 were done robotically. Preoperative co-morbidities were similar but the robotic patients were an average of 4 years younger, which was statistically significant, p < 0.001.

The main results were that the complications, deaths, extent of lymph nodes removed were not significantly different between the two groups. The robotic surgery took significantly longer (49 minutes) to perform, p < 0.001. The average estimated blood loss was statistically significantly less in the robotic patients, (91.6 mL vs 147.9 mL, p = 0.002). Hospital length of stay (LOS) was significantly shorter for the standard laparoscopic group, 7.0 vs. 7.7 days, p= 0.004.

The authors concluded “robotic gastrectomy [has] better short-term and comparable oncologic outcomes compared with laparoscopic gastrectomy.”

Is this conclusion valid? Let’s take a closer look.

The study was not randomized nor was it prospective. Despite the similar number of patients with co-morbidities in both groups, patients chosen for robotic surgery were obviously selected for suitability. Other confounding factors may not have been unaccounted for. The only short-term advantage for robotic surgery was in the estimated blood loss. The authors themselves admit, “The statistically significant difference in 56.3 mL of blood loss between the robotic and laparoscopic groups may not translate into much clinical benefit for every individual patient.” This is certainly true. In addition, estimated operative blood loss is notoriously inaccurate. A study involving spine surgery showed that estimated blood loss exceeded measured blood loss by a mean of 248 mL (p = 0.0001). And since the study was not blinded, the blood loss estimates could easily have been biased.

Hospital LOS was actually longer for the robotic patients, amounting to 0.7 of a day or 17 hours. The authors tried to explain away the difference in LOS by pointing out that the robotic group had a couple of outliers who had really long LOSs. As I have blogged before, LOS is a soft endpoint which can be affected by many things other than the clinical state of the patient.

The study did not mention readmission rates for either group. Long-term follow-up was not included in the study, meaning that the oncologic outcome has yet to be determined. The issue of cost was neatly avoided by a convoluted explanation of the uniqueness of the Korean national insurance program and individual hospital differences. However, the methods section of the paper did note that the patients would have to pay for the extra costs of robotic surgery themselves. This suggests that the robotic patients may have been from a higher socioeconomic group. Robotic surgery is unquestionably more expensive as the robot itself costs $1.5-2.0M with an annual service contract of at least $150K and disposable instrument costs of about $2K per case. A New England Journal article estimated the actual additional cost of each robotic procedure at $3.2K.

So you tell me, does robotic gastrectomy have better short-term results than standard laparoscopic gastrectomy?