These data suggest that RASP may lower perioperative morbidity compared to that of OSP with shorter length of stay, less blood loss and fewer complications as a result of changing the surgical approach from open to robotic. However, due to the relatively low number of cases, these data must be interpreted cautiously. OSP is the oldest surgical treatment of moderate to severe LUTS due to benign prostatic hyperplasia and provides an effective reduction of LUTS, increases maximum urinary flow and improves quality of life[1, 5–9]. However, OSP is associated with bleeding complications with estimated transfusion rates of 7–14% of reported cases[2, 5, 8, 10]. Previous studies comparing OSP with RASP have similarly to our results demonstrated a benefit of less bleeding as an advantage of the RASP procedure[11–15]. In our experience, the hemostasis during enucleation of the prostatic adenoma is often hard to maintain in both these surgical procedures, in which multiple vessels between the adenoma and the prostatic capsule are divided. In contrast to OSP, however, improved visibility provided by the da Vinci Surgical system facilitates the trigonization of the bladder, which subsequently leads to adequate hemostasis as illustrated in Fig. 1. The lower bleeding volumes in RASP is also the reason why 18 French two-way catheters are routinely utilized instead of catheters with 22–24 French diameters, which are recommended in OSP. Similarly, RASP patients are transferred from the operating theatre without a drain in the space of Retzius, while this is considered mandatory to patients who have been subjected to OSP.
Opponents of the RASP procedure have previously pointed out that the surgery is more time consuming and more costly than that of OSP[11]. Our data also demonstrate, as has been argued, that operating time was significantly longer in the RASP group compared to the OSP group. However, we underline that operating times reported in this study include the learning curve for the RASP procedure. When we compared the operating time of the first 13 RASP cases (130 ± 28 minutes) to the last 13 (103 ± 23 minutes), we found that the operating time actually dropped by an average of 27 minutes, which is almost identical to the operating time in the OSP group (100 ± 24 minutes). As has been demonstrated for other robotic procedures, operating time for RASP is likely to decrease until the learning curve of the robotic procedure reaches a plateau phase. The learning curve for RASP has previously been suggested to be 10–12 cases for experienced robotic surgeons[16].
The cost of OSP versus the cost of RASP has been a subject of debate, with conflicting conclusions, depending on whether the length of stay and or complications are included in the calculations[11]. The present study indicates that an average of 4 days of hospitalization can be deducted from the accounting in the RASP group, which in Norwegian health care equals approximately 8000 USD. If the cost of the complications in the present study are added to the estimated cost analysis of the OSP group, we argue that RASP most certainly will prove to be the most favourable financial alternative, although a detailed cost analysis of the respective procedures was beyond the scope of this work.
Limitations of the study include the low number of cases in each of the study groups and the retrospective design. The data are collected from a single institution, and should therefore be interpreted cautiously. However, the differences in perioperative morbidity between the groups in this study are quite overwhelmingly in favour of RASP compared to OSP, in spite of the fact that the learning curve of RASP is included herein. We argue that RASP should be preferred to OSP in the absence of an effective transurethral enucleation technique and suggest that the increased costs of robotic surgery should be weighed against the benefit associated with a significant drop in perioperative morbidity.