Let's Just Call It a Draw: Open vs Robotic-Assisted Radical Prostatectomy

During a heated discussion about the pros and cons of different surgical approaches with a Brady (Hopkins) urology resident, the emeritus chairman, Dr. W.W. Scott, made an astute comment that put the argument into perspective….“when penicillin was introduced, we didn’t need a randomized study to show its benefit.”

Today, the relative effectiveness and morbidity of open vs robotic-assisted radical prostatectomy (RP) remains a controversial and hotly debated topic. Once again, I will have the pleasure and privilege to debate on the side of the open approach in May 2014 at the AUA annual meeting in Orlando. I believe the debate will be resolved only when a randomized study is performed by surgeons of equivalent experience.

The question is how will an open surgeon react to the conclusions made by Pilecki et al? In their recently published manuscript titled National Multi-Institutional Comparison of 30 Day Post-operative Complications and Readmission Rates Between Open and Radical Retropubic Prostatectomy and Robot Assisted Laparoscopic Prostatectomy. Using the National Surgical Quality Improvement Program (NSQIP), the authors conclude that complications and readmission rates are more favorable with the robotic approach.1 Is the battle over? Do we, as open surgeons, admit defeat? The answer is emphatically NO!

The major limitation of the study is that it is not properly designed to compare the intrinsic advantages and disadvantages of the different surgical approaches. Rather, it simply evaluates outcomes of men undergoing RP at 400 institutions across the country who participate in the NSQIP. There is ample evidence in the literature that complications and outcomes are dependent on factors associated with the patients, surgeons, and hospitals. Age, comorbidity, and race have all been associated with outcomes (complications and health-related quality of life) following RP. RP performed by high-volume surgeons is consistently associated with fewer complications. Surgical complications are also dependent on hospital RP surgical volume, geographic location, and association with a teaching center. So, were these known predictors of outcome comparable in the open and robotic groups in the study by Pilecki?

The men undergoing open RP were significantly older. In the text, the proportion of men who were Caucasian in the open vs robotic groups were 62% vs 81%, respectively. Unfortunately, there appears to be a typographical error in Table 1, which undoubtedly was inadvertent, regarding racial distribution. The table indicates that 3.9%% and 9.0% of men undergoing open vs robotic RP were black, respectively. In actuality, 39% of men in the open cohort were black. If this is the case, the percentage of black men in the open cohort was over four times greater than in the robotic cohort. Pollack et al recently reported that 48% and 5.2% of black and white men, respectively, seeking care for localized prostate cancer are managed at hospitals with a high proportion of black men. It is unclear why an effort was not made to determine if race predicted outcome owing to the major racial disparity between the open vs robotic groups. The authors do recognize as a limitation of their study design that they didn’t account for surgeon and hospital volumes. So, the study is really comparing apples and oranges.

A major proportion of the complications in the open group were attributable to a transfusion. Many open surgeons recommend preoperative autologous blood donation. Do we know if the transfusions were autologous or heterologous? An 18% transfusion rate is exceedingly high for open RP in the modern era. Experienced open surgeons consistently report transfusion rates < 5%. The high transfusion rate in the open group is likely attributed to a high proportion of open surgeries performed by low-volume surgeons. Also, what were the reasons for the unplanned readmission? In the absence of uniform pathways for readmission, these differences may reflect different thresholds of open vs robotic surgeons for readmission rather than a higher level of serious complications driving the readmissions. How were readmission rates captured? Were they readmissions to the hospital performing the surgery or any readmission to any hospital? Many men who seek their care at tertiary hospitals may be readmitted to local hospitals.

So, what happens when we level the playing field and compare apples and apples?

Sammon et al reported on complications following robotic vs open RP but, unlike Pilecki, they accounted for procedure volume of the surgeons.2 Using the National Inpatient Sample (NIS), data were collected on 77,616 men who underwent RP in 2009. Of these men, 64% and 36% underwent RP via the robotic vs open approaches, respectively. Men undergoing the robotic approach were significantly more likely to be white (66% vs 62%) and more likely to have surgery performed in an urban location (71% vs 57%). Median hospital volume was 137 vs 32 for robotic vs open procedures.

Overall, Sammon reported that robotic-assisted RP was associated with a lower complication rate. However, when high-volume open and robotic centers were compared, there were no significant differences in complications. Interestingly, Sammon captured specifically homologous transfusion rates, which was 8.2% in the open group. The almost threefold higher transfusion rate in the open group reported by Pilecki is further evidence that the open surgeons were likely low-volume surgeons.

Pierorazio et al examined immediate and perioperative morbidity and delay of discharge for 4950 and 1422 men undergoing open and robotic RP, respectively, at Johns Hopkins Hospital between 2005 and 2011.3 A total of 15 vs 6 surgeons performed the open vs robotic procedures, respectively. The mean number of cases performed by the open and robotic surgeons were also similar (328 vs 226). The percentage of Caucasian men in the open and robotic cohorts were similar (83.0% vs 80.6%). The median age was 59 years in both groups, and there was no significant difference between the groups for the Charlson Comorbidity Index. The length of hospital stay for the open vs robotic cases was 1.87 vs 1.96, respectively. The proportion of off-pathway discharges for men undergoing open vs robotic RP was 1.2% and 4.0%, respectively. General surgical or anesthesia complications were similar between the surgical groups, with the exception of ileus, which was higher in the robotic groups since it is an intra-peritoneal approach. Interesting, even among high-volume surgeons, race and surgical experience predicted off-pathway discharge.

Alzemozaffar et al recently reported outcomes for 1065 men participating in the Health Professionals Follow-Up Study who underwent RP between 2000 and 2010. While they did not report or stratify outcomes according to race, surgeon, or hospital volume, it is reasonable to assume that access to high-performing surgeons and hospitals was equal for the health professionals. There were no significant differences between oncologic and health-related quality of life between the surgical groups.

So, is open or robotic RP the superior approach? Did the paper by Pilecki et al help answer the question? It is clear from my review that the answer is no. Unfortunately, unlike penicillin, we do need a multicenter randomized trial of equally skilled surgeons to definitively answer the question. Is this a study worth pursuing? I don’t think so. Based on my extensive review of the literature, the only legitimate advantage of the robotic approach is less blood loss. We have shown that the amount of blood loss during open RP does not influence rates of positive margins, biochemical recurrence, continence, or potency. We have also shown that two doses of erythrocyte-stimulating proteins administered preoperatively neutralizes the blood loss advantage of the robotic approach. As urologists, we have much more important issues related to prostate cancer to pursue, such as discovering better screening markers, improving detection with advanced imaging and image-guided biopsy, enhancing risk stratification with molecular signatures, and critically examining the emerging role of focal ablation of prostate cancer. Several years ago, I wrote an article addressing who benefited from robotic RP. Today, the answer is the same as in years past—neither the patient nor the healthcare system has seen any tangible benefits from the robot. It is time to call it a draw and move on. Unfortunately, at the expense of the cost of healthcare delivery.

Herbert Lepor MD



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