The goal of a radical prostatectomy is to remove the entire prostate with negative surgical margins, preferably with minimal intra- or perioperative complications, with no blood transfusions and with a full recovery of baseline urinary continence and erectile function 12
. Although more improvements are still required to achieve this ideal, RALRP is currently one of the most promising, minimally invasive treatment options. Over 50% of prostatectomies in the United States were performed with RALRP in 2007 13
, and it has now become a part of mainstream urology. Many urologists are struggling to incorporate this technique into their therapeutic arsenal. The success of RALRP is mainly based on evidence that the characteristics of robotics contribute to shortening the learning curve and facilitating the transition from a standard open radical prostatectomy to a laparoscopic radical prostatectomy (LRP) without the time-intensive training necessary to gain the skills for laparoscopy 14, 15, 16
. For surgeons with no experience in laparoscopy, the learning period of LRP amounted to as many as 80–100 consecutive cases, extending over several years 3
. In contrast, for RALRP, Patel et al.
estimated that 20–25 cases were required to achieve technical proficiency, and Ahlering et al.
observed that their RALRP operative times declined continually until case 19, after which they essentially maintained a nadir level. Our experience confirms such data in the literature. The total operation time, setup time, console time and EBL decreased with accumulation of cases. Of great interest to our study, no patient needed a blood transfusion after the initial 15 cases, and no radiological evidence of urine leakage occurred after 20 cases. Our results, as well as the data in the literature, would suggest that 15–20 cases might be the number of procedures needed for a surgeon with experience in open prostatectomies to overcome the learning curve. However, considering that the learning curve varies according to surgeon-related factors, such as earlier surgical experience, surgeon-declared perception of expertise, definition of expertise and workload 18
, these results might be affected by earlier experience with surgical prostatectomies. Although patients who have had a previous abdominal operation are best suited for the extraperitoneal route, the surgeon's open surgical experience is integral in performing transperitoneal RALRP in patients with a history of previous abdominal surgery. Thirteen patients had a history of various open transperitoneal abdominal surgeries, including herniorrhaphy (4), appendectomy (4), gastrectomy (3), cholecystectomy (2), ureterolithotomy (1) and repair of small bowel rupture (1). Two patients with herniorrhaphy had multiple transperitoneal operations (one with cholecystectomy, one with gastrectomy). Although the mean total operation time (301 ± 127 min vs.
278 ± 89 min, P
= 0.293), setup time (19.4 ± 5.5 min vs.
17.9 ± 3.8 min, P
= 0.053), console time (227 ± 137 min vs.
214 ± 456 min, P
= 0.317) and EBL (391 ± 212 mL vs.
372 ± 200 mL, P
= 0.473) were mildly increased in patients with earlier abdominal surgery compared with the remaining patients, the difference was not statistically significant. Therefore, to overcome the learning curve, we surmise that open surgical experience and an understanding of the pelvic anatomy are pivotal.
Although the decreased morbidity associated with RALRP is likely attributable to the minimally invasive characteristics, the key benefit of RALRP has been the improvement of oncological outcomes in patients. Although the ultimate measure of any intervention is the ability to prolong long-term survival, modifications in surgical technique can be assessed in the short term by analyzing pertinent oncological principles. One such variable is the pathology of the tumor margins, and the incidence of PSM in OC prostate cancer is directly related to the quality of surgery 19
. In a recent systemic review, including 22 robotic prostatectomy reports, the weighted means of PSM for robotic, laparoscopic and open radical prostatectomies were 10.3%, 20.2% and 18.3%, respectively 4
. In patients with pathologically OC prostate cancer, our PSM rate of 9.8% was similar to that reported in the main published study, and these data emphasize that a high standard of quality was achieved, even during the learning curve. In addition, the PSM rate, as with other surgical parameters, was affected by surgical experience. In a review of open radical prostatectomies, Vickers et al.
reported that cancer control after a radical prostatectomy improves as a surgeon's experience increases, which is presumably due to improved surgical technique. Similarly, in an open study by Ahlering et al.
, the reported PSM rate was 14.8% for OC disease in an initial report of 45 robotic cases, but this decreased to 6.5% after experience with 200 cases. Additionally, Patel et al.
reported a PSM rate of 5.7% for OC disease in the initial 200 cases, but this number decreased to 2.5% after 500 consecutive cases. In our study, the PSM rate of OC disease was decreased from 12.5% (3/24) among the initial 30 cases to 7.4% (2/27) among the latter 33 cases. Furthermore, no difference existed in the pathological distribution of tumors between our initial 30 patients and the latter 33 patients (six vs.
six cases of ECE). Collectively, these data suggest that the decline in the PSM rate is mostly attributed to improved surgical skill with the robotic technique, rather than a decrease in the number of biologically aggressive tumors.
There is still room for technical improvement in the NVB preservation procedure. Among 51 OC diseases, 44 had NVB preservation procedures in our study, and among PSM cases, the lateral side of the prostate was the most frequent location (60%). These numbers are similar to the 56% observed by Patel et al.
, who introduced the NVB preservation procedure used in our study. Owing to penetrating vessels and a concern for erectile dysfunction, the lateral aspect of the prostate is one of the most frequent locations of PSM. Therefore, initiation of NVB preservation from the lateral aspect of the prostate by blunt dissection has the possibility of increasing PSM on the lateral side of the prostate. Recently, Shah et al.
introduced a unique technique of NVB preservation and reported a PSM rate of 3.2%. Instead of a sharp dissection at the posterior lateral side of the prostate, they initiated NVB release at the base of the prostate and carried it to the apex. Although more data are required to validate the advantage of this novel approach, identification of the plane between the prostate capsule and the NVB would be the key process in decreasing lateral PSM.
The high PSM rate of ECE disease in our study warrants discussion. One of the plausible explanations for the high incidence would be the characteristics of the tumor. The initial PSA was significantly increased in ECE disease compared with that of OC disease, which differed from other variables. This finding correlates well with the results of Liss et al.
, who reported that the most important risk factor for a PSM after RALRP was the preoperative PSA level. Their study analyzed 216 consecutive patients who had undergone RALRP. In addition, our study included five patients who had neoadjuvant therapy before the operation, and their final stage was shown as pT3b (1), pT3c (3) and T4 (1). In those patients, the operative time and EBL were significantly increased to 314 ± 29 min and 443 ± 87 mL, respectively, compared with those of OC patients (P
< 0.05 by Kruskal-Wallis test). These results indicate that the characteristics of a tumor with higher PSA and adhesion to the local structure at the time of operation may affect the high PSM of the ECE disease. However, we also recognize the effect of a surgeon's learning curve on this high PSM rate. In our cases of ECE disease, although multifocal PSM was the most frequent, most of the PSMs occurred in the initial 30 cases, with only one occurring in the latter 33 patients. This result implies that inadequate resection of advanced disease decreased as the surgeon accumulated cases of RALRP.
Despite the importance of cancer control, patients are often equally concerned with any negative effects on urinary continence and sexual potency in the period immediately after surgery. Attempts to eliminate these two functional side effects are critical during treatment innovations. Whereas the current study was limited by the minimal follow-up of 3 months, 84.1% of the patients were totally continent, and the mean time to continence was 6.56 weeks. These results are comparable to the results of a high-volume center 4, 25
. Conclusions regarding sexual function are pending. Sexual potency generally requires more time to return to normal. Thus, this study presents the results of restrictive patients who had OC disease with preoperative active sexual intercourse, minimally one side of the NVB preserved and more than 6 months of follow-up. In SEP, which was used in our study to evaluate potency postoperatively because of its simplicity and convenience, 70.6% of patients were capable of satisfactory intercourse postoperatively. Besides efforts to preserve the NVB, if indicated, and to aid in early penile rehabilitation, we tried to protect every possible APA during the procedure, which would help to improve the early potency rate. Among the 63 cases, we encountered nine cases of APA, including two cases of multiple APAs, which were successfully preserved in seven cases. Although no unequivocal role has been established on APA preservation and postsurgical functional outcomes 26
, recent reports 27, 28
indicate that the preservation of APA during a radical prostatectomy increases the likelihood of potency more than twofold, and these patients show a significantly shorter median time to regain potency.
In our study, the prolonged patient hospitalization of 8.7 days, compared with that of other published RALRP reports, requires explanation. Korean Health Care is national and mandatory, and the entire cancer population is covered. Because of this national coverage, the hospital admission cost can be maintained at a minimum compared with the costs of other nations. Therefore, the patients and doctors alike were not aggressive in scheduling an early discharge. Most patients expected to be discharged after the stitches were completely removed, which was routinely performed 7 days after operation. As per foreign standards, many patients in our study would have been discharged 3 or 4 days earlier.
In conclusion, the RALRP in our study was a reproducible technique with a relatively short surgeon learning curve and excellent postoperative outcomes. The low rate of PSMs reported in pathologically localized prostate cancer, as well as early functional recovery, showed that high standards of surgery could be reached even in the relatively early stages of the learning curve. However, urologists should acknowledge the fact that the outcome of a radical prostatectomy is significantly more dependent on the surgeon's technique, experience and regular practice than on the particular approach used.