LRP has been well established with functional and oncological outcomes similar to open radical prostatectomy for nearly 20 years, with reduced blood loss, reduced analgesic requirements, and the advantages of hospital discharge and recovery [11,12,13]. It is necessary to understand the learning curve of a surgical procedure and to shorten the learning curve in order to avoid possible complications. Factors investigated in this study are crucial for surgical training as well as interventions to shorten the learning curve. Controversy continues on the number of cases required to become proficient in LRP. There has been no consistent definition of how many patients per surgeon should be operated for favorable outcomes. The findings of our study have important clinical implications. Our study showed that there was a plateau from the beginning, in PSM, the rate of potency, the rate of continence, urinary catheter time, and hospital stay, unlike the majority of the previously published reports [14, 15]. These results may reflect the benefits of a modular mentored fellowship in LRP at a high-volume center.
In this study, we analyzed the 6 months’ outcomes of 80 cases of ELRP, performed by a single surgeon who completed a 2-year modular mentored training on laparoscopy. We think that previous training in high-volume centers for 2 years, treating > 150 cases per year, should influence the result of the PSM, and this rate decreases faster during the learning curve (LC) in LRP. However, we know that the duration of training is different between surgeons, even within the same institution, and trained by the same mentors .
LRP is an advanced surgical procedure that requires significant laparoscopic expertise and has a prolonged operative duration that would be associated with a greater risk of developing complications . Recently, researchers have shown that about 50–60 cases are enough for surgeons who had a previous laparoscopic experience, in learning curve [18, 19]. A 2012 study found that previous experience of trainees in laparoscopic surgery could improve laparoscopic surgical skills in terms of short-term outcomes . Fabrizio et al. demonstrated that trainee operating with a mentor had shorter operation time compared to the operations that were performed alone. . Moreover, it is not known how long training is needed to achieve excellent results in laparoscopy. In this study, we have demonstrated that after adequate formal training in a high-volume center, LRP can be performed as the primary operating surgeon safely with favorable outcomes. We used the PSM rate as a marker of oncological safety and continence rate as a marker of functional outcome.
PSM status is a parameter that cannot be misevaluated and can, therefore, be used as an objective parameter in the follow-up of the learning curve . Secin et al. showed that the learning curve for PSM was overcome after approximately 200–250 cases in a multicenter study that included 1862 patients . Rassweiler et al. and Jacob et al. found that positive margin rates after LRP range from 15 to 44% and 18.9%, respectively [23, 24]. In a comprehensive review that included 14 studies on LRP, PSM was between 6.1% and 21.9% in patients with pT2 stage and between 17.2% and 54.4% in patients with pT3 stage . Also, the reduction of PSM rates of the apex and the posterolateral margins of the prostate was associated with experience and the learning curve [26, 27]. Rodrigeuz et al. also showed a plateauing of PSM rates in their series after 200 cases . In our study, there was no difference in means of PSM between groups. Although T3 prostate cancers are a very heterogeneous group and, therefore, PSM is not dependent on the surgeon, PSM in patients who have a final pathological stage of pT2 is mostly dependent on the surgeon. In our study, both in the patients with pathological stages of pT2 and pT3, PSM was not significantly different among the study groups.
Although the PSM rate can be reduced by performing wide tumor dissection, potency and continency rates decrease due to sacrificing the neurovascular bundle and the necessary anatomical structures that would maintain continence. Therefore, a low PSM ratio should not be the criterion of the learning curve alone. Additionally, functional and long-term oncological outcomes should also be considered. Continence rates following LRP vary between 73 and 90% at postoperative 6 months and 71.6% and 97.7% at postoperative 12 months . Our overall continence rate at 6th month was 87.5%, which was consistent with the previous reports. In the same review, potency rates in 15 studies varied between 46 and 72% at postoperative 12 months. The potency rate in the patients in whom the bilateral nerve sparing technique was performed, was close to the lower limit in our study however these were the outcomes at postoperative 6 months, which might further improve during the follow-up. Our study showed that no significant difference in functional outcomes was observed between the groups.
In a recent review, including 13 studies and 1674 patients having LRP, intraoperative complications occurred in 33 (2.0%) cases and postoperative complications occurred in 204 (12.2%) cases . Good et al. reported the pentafecta outcomes in a retrospective study, including 550 patients, and reported the overall complication rate as 8.9% which fell below the mean level for the series after 50 cases . They showed that the complications learning curve showed a continual decline throughout the series, starting to plateau after 150 cases. Consistent with the previous reports, the overall complication rate was 8.8% in our series, and the majority of those were minor complications.
There are several limitations to our study. The most critical issues were the limited number of patients and the short follow-up time. Although we could compare the groups sufficiently to demonstrate the effects of the learning curve of a single surgeon, further analysis of oncological and functional outcomes such as biochemical recurrence and long-term continence and potency rates would be possible with a longer follow-up time. Also, due to the low overall complication rate, the effects of the learning curve on the complication rate could not be determined.