OBJECTIVE:
To compare the quality of surgical management of the neurovascular bundle (NVB) by assessment of neuronal nitric oxide synthase (nNOS)-positive nerves in surgical specimens between open retropubic radical prostatectomy (RP; ORRP) and robot-assisted RP (RARP).
METHODS:
This study included 65 (99 sides, NVB resection; 31 sides, NVB preservation) and 83 (106 sides, NVB resection; 60 sides, NVB preservation) patients undergoing ORRP and RARP, respectively. The posterior sectors from the apex, mid, and base areas on each side were immunohistochemically stained with an nNOS antibody.
RESULTS:
On the sides with NVB resection, there were no significant differences in the numbers of nNOS-positive nerves in any areas between the ORRP and RARP groups; however, on the sides with NVB preservation, the numbers of nNOS-positive nerves in the ORRP group were significantly higher than those in the RARP group at the apex (84.4 vs 59.2; P = .0028), mid (71.2 vs 52.4; P = .016), and base (148.0 vs 40.8; P <.001) areas. In 55 patients who were judged not to have severe erectile dysfunction before surgery and subsequently underwent nerve-sparing RP, there was a significantly inverse correlation between the total number of nNOS-positive nerves on both sides and the postoperative erectile function.
CONCLUSION:
These findings suggest that RARP might be suitable for performing precise nerve-sparing surgery compared with ORPP, particularly in the base area of the prostate and that the quantification of nNOS-positive nerves in surgical specimens could be a useful approach for predicting the postoperative erectile function.