1. This is an Open Access article distributed under the terms of the Creative Commons Attribution Non-Commercial License (http://creativecommons. org/licenses/by-nc/3.0/) which permits unrestricted non-commercial use, distribution, and reproduction in any medium, provided the original work is properly cited. Comparison of Predictive Factors for Postoperative Incontinence of Holmium Laser Enucleation of the Prostate by the Surgeons’ Experience During Learning Curve Katsumi Shigemura, Kazushi Tanaka, Fukashi Yamamichi, Koji Chiba, Masato Fujisawa Division of Urology, Department of Organ Therapeutics, Faculty of Medicine, Kobe University Graduate School of Medicine, Kobe, Japan International Neurourology Journal 2016;20:59-68

2. PURPOSE To detect predictive factors for postoperative incontinence following holmium laser enucleation of the prostate (HoLEP) according to surgeon experience (beginner or experienced) and preoperative clinical data. International Neurourology Journal 2016;20:59-68

3. Methods Of 224 patients, a total of 203 with available data on incontinence were investigated. The potential predictive factors for post-HoLEP incontinence included clinical factors, such as patient age, and preoperative urodynamic study results, including detrusor overactivity (DO). We also classified the surgeons performing the procedure according to their HoLEP experience: beginner (<21 cases) and experienced (≥21 cases). International Neurourology Journal 2016;20:59-68

4. Results Our statistical data showed DO was a significant predictive factor at the super-short period (the next day of catheter removal: odds ratio [OR], 3.375; P=0.000). Additionally, patient age, surgeon mentorship (inverse correlation), and prostate volume were significant predictive factors at the 1-month interval after HoLEP (OR, 1.072; P=0.004; OR, 0.251; P=0.002; and OR, 1.008; P=0.049, respectively). With regards to surgeon experience, DO and preoperative International Prostate Symptom Score (inverse) at the super-short period, and patient age and mentorship (inverse correlation) at the 1-month interval after HoLEP (OR, 3.952; P=0.002; OR, 1.084; P=0.015; and OR,1.084; P=0.015; OR, 0.358; P=0.003, respectively) were significant predictive factors for beginners, and first desire to void (FDV) at 1 month after HoLEP (OR, 1.009; P=0.012) was a significant predictive factor for experienced surgeons in multivariate analysis. International Neurourology Journal 2016;20:59-68

5. Conclusions Preoperative DO, IPSS, patient age, and surgeon mentorship were significant predictive factors of postoperative patient incontinence for beginner surgeons, while FDV was a significant predictive factors for experienced surgeons. These findings should be taken into account by surgeons performing HoLEP to maximize the patient’s quality of life with regards to urinary continence. International Neurourology Journal 2016;20:59-68

6. Table 1. Patients’ characteristics (n=203) HoLEP, holmium laser enucleation of the prostate; CI, confidence interval; IPSS, International Prostate Symptom Score; MVP, maximum voiding pressure; MCC, maximum cystometric capacity. *P<0.05, statistical significance. International Neurourology Journal 2016;20:59-68 CharacteristicValue Age (yr), median (range)71 (34–90) Prostate volume (mL)76.1±41.1 Resected prostate weight (g)52.9±35.3 Surgical time (min)172±63.4 Enucleation time (min)113±45.3 Morcellation time (min)29.6±28.4 Surgeons, n (%) Performed by experienced 84 (41.4) Performed by beginners 119 (58.6) Prostate cancer, n (%)16 (7.88) Values are presented as mean±standard deviation unless otherwise indicated.

7. Table 2. Predictive factors for incontinence at 1 month after HoLEP in all surgeons HoLEP, holmium laser enucleation of the prostate; CI, confidence interval; IPSS, International Prostate Symptom Score; MVP, maximum voiding pressure; MCC, maximum cystometric capacity. *P<0.05, statistical significance. International Neurourology Journal 2016;20:59-68 Variable UnivariateMultivariate Odds ratio95% CIP-valueOdds ratio95% CIP-value Age1.0380.997–1.0800.067 Preoperative IPSS0.9870.944–1.0310.551 Quality of life0.9920.687–1.4340.968 Operation time1.0071.003–1.0120.002 * 0.9990.988–1.0110.894 Enucleation time1.0101.003–1.0170.003 * 1.0090.995–1.0230.216 Morcellation time1.0080.997–1.0180.141 Mentorship0.6970.367–1.3230.270 Resected prostate weight1.0091.001–1.0170.036 * 0.9970.972–1.0220.815 Prostate volume1.0071.000–1.0140.049 * 1.0060.986–1.0270.546 MVP1.0071.000–1.0140.067 Compliance0.9900.980–1.0000.056 Detrusor overactivity3.3361.826–6.095< 0.000 * 3.3751.790–6.3630.000 * Schafer1.1710.921–1.4900.198 First desire to void0.9980.994–1.0020.419 MCC0.9980.996–1.0010.136 Residual volume1.0000.997–1.0020.899 HoLEP, holmium laser enucleation of the prostate; CI, confidence interval; IPSS, International Prostate Symptom Score; MVP, maximum voiding pressure; MCC, maximum cystometric capacity. *P<0.05, statistical significance.

8. Table 3. Predictive factors for incontinence at 1 month after HoLEP in all surgeons HoLEP, holmium laser enucleation of the prostate; CI, confidence interval; IPSS, International Prostate Symptom Score; MVP, maximum voiding pressure; MCC, maximum cystometric capacity. *P<0.05, statistical significance. International Neurourology Journal 2016;20:59-68 Variable UnivariateMultivariate Odds ratio95% CIP-valueOdds ratio95% CIP-value Age1.0861.036–1.1370.001 * 1.0721.023–1.1240.004 * Preoperative IPSS0.9750.932–1.0210.281 Quality of life0.7490.517–1.0860.127 Operation time1.0051.000–1.0090.055 Enucleation time1.0061.000–1.0130.062 Morcellation time1.0050.995–1.0160.292 Mentorship0.2250.095–0.5340.001 * 0.2510.104–0.6090.002 * Resected prostate weight1.0081.000–1.0160.057 Prostate volume1.0081.001–1.0150.024 * 1.0081.000–1.0150.049 * MVP1.0030.995–1.0100.503 Compliance0.9940.985–1.0040.237 Detrusor overactivity1.0550.582–1.9100.861 Schafer1.0270.809–1.3030.829 First desire to void1.0030.999–1.0080.107 MCC1.0010.998–1.0030.637 Residual volume1.0010.999–1.0040.316 HoLEP, holmium laser enucleation of the prostate; CI, confidence interval; IPSS, International Prostate Symptom Score; MVP, maximum voiding pressure; MCC, maximum cystometric capacity. *P<0.05, statistical significance.

9. Table 4. Predictive factors for incontinence at 1 month after HoLEP in all surgeons HoLEP, holmium laser enucleation of the prostate; CI, confidence interval; IPSS, International Prostate Symptom Score; MVP, maximum voiding pressure; MCC, maximum cystometric capacity. *P<0.05, statistical significance. International Neurourology Journal 2016;20:59-68 HoLEP, holmium laser enucleation of the prostate; CI, confidence interval; IPSS, International Prostate Symptom Score; MVP, maximum voiding pressure; MCC, maximum cystometric capacity. *P<0.05, statistical significance. Variable UnivariateMultivariate Odds ratio95% CIP-valueOdds ratio95% CIP-value Age1.0530.996– 1.114 0.071 Preoperative IPSS1.0070.951– 1.067 0.802 Quality of life0.9430.594– 1.497 0.803 Operation time1.0030.997– 1.009 0.291 Enucleation time1.0010.992– 1.010 0.849 Morcellation time1.0040.991– 1.016 0.581 Mentorship0.5090.184– 1.406 0.192 Resected prostate weight1.0060.996– 1.016 0.230 Prostate volume1.0060.998– 1.015 0.143 MVP0.9960.986– 1.006 0.407 Compliance0.9970.984– 1.010 0.681 Detrusor overactivity1.3280.601– 2.932 0.483 Schafer0.8520.633– 1.147 0.290 First desire to void1.0051.000– 1.010 0.0471.0040.992– 1.016 0.516 MCC1.0010.998– 1.004 0.496 Residual volume1.0010.998– 1.004 0.393

10. Table 5. Predictive factors for incontinence at the next day of catheter removal after HoLEP in beginner surgeons HoLEP, holmium laser enucleation of the prostate; CI, confidence interval; IPSS, International Prostate Symptom Score; MVP, maximum voiding pressure; MCC, maximum cystometric capacity. *P<0.05, statistical significance. International Neurourology Journal 2016;20:59-68 HoLEP, holmium laser enucleation of the prostate; CI, confidence interval; IPSS, International Prostate Symptom Score; MVP, maximum voiding pressure; MCC, maximum cystometric capacity. *P<0.05, statistical significance. Variable UnivariateMultivariate Odds ratio95% CIP-valueOdds ratio95% CIP-value Age1.0210.971–1.0730.422 Preoperative IPSS0.9330.879–0.9900.022 * 0.8920.828–0.9620.003 * Quality of life1.1130.707–1.7520.643 Operation time1.0030.998–1.0090.257 Enucleation time1.0030.994–1.0120.490 Morcellation time1.0030.991–1.0160.585 Mentorship0.6420.305–1.3500.243 Resected prostate weight1.0060.995–1.0180.273 Prostate volume1.0050.994–1.0150.396 MVP1.0091.000–1.0190.055 Compliance0.9910.979–1.0020.118 Detrusor overactivity3.5611.568–8.0890.002 * 7.0692.235–22.3580.001 * Schafer1.2910.922–1.8070.137 First desire to void0.9940.988–1.0000.0440.9920.980–1.0040.189 MCC0.9960.992–0.9990.0191.0000.993–1.0070.961 Residual volume0.9990.995–1.0030.504

11. Table 6. Predictive factors for incontinence at 1 month after HoLEP in beginner surgeons HoLEP, holmium laser enucleation of the prostate; CI, confidence interval; IPSS, International Prostate Symptom Score; MVP, maximum voiding pressure; MCC, maximum cystometric capacity. *P<0.05, statistical significance. International Neurourology Journal 2016;20:59-68 HoLEP, holmium laser enucleation of the prostate; CI, confidence interval; IPSS, International Prostate Symptom Score; MVP, maximum voiding pressure; MCC, maximum cystometric capacity. *P<0.05, statistical significance. Variable UnivariateMultivariate Odds ratio95% CIP-valueOdds ratio95% CIP-value Age1.0991.028–1.1740.005 * 1.0841.016–1.1570.015 * Preoperative IPSS0.9610.900–1.0260.234 Quality of life0.8180.515–1.2990.395 Operation time1.0040.998–1.0110.169 Enucleation time1.0070.997–1.0160.172 Morcellation time1.0010.988–1.0140.855 Mentorship0.3040.127–0.7300.008 * 0.3580.145–0.8830.026 * Resected prostate weight1.0040.992–1.0160.520 Prostate volume1.0010.990–1.0130.838 MVP0.9990.989–1.0090.880 Compliance0.9950.984–1.0070.404 Detrusor overactivity1.2030.531–2.7270.658 Schafer0.9740.700–1.3560.878 First desire to void1.0000.994–1.0060.926 MCC0.9980.995–1.0020.337 Residual volume1.0000.996–1.0050.852

12. Table 7. Predictive factors for incontinence at 3 months after HoLEP in beginner surgeons HoLEP, holmium laser enucleation of the prostate; CI, confidence interval; IPSS, International Prostate Symptom Score; MVP, maximum voiding pressure; MCC, maximum cystometric capacity. *P<0.05, statistical significance. International Neurourology Journal 2016;20:59-68 HoLEP, holmium laser enucleation of the prostate; CI, confidence interval; IPSS, International Prostate Symptom Score; MVP, maximum voiding pressure; MCC, maximum cystometric capacity. *P<0.05, statistical significance. Variable UnivariateMultivariate Odds ratio95% CIP-valueOdds ratio95% CIP-value Age1.0640.989–1.1440.099 Preoperative IPSS0.9060.828–0.9910.031 * 0.9110.834–0.9960.040 * Quality of life1.0810.620–1.8840.784 Operation time1.0081.000–1.0150.0461.0050.994–1.0160.375 Enucleation time1.010.998–1.0210.097 Morcellation time1.0040.990–1.0190.539 Mentorship0.5730.210–1.5590.276 Resected prostate weight1.0050.991–1.0190.499 Prostate volume1.0020.988–1.0160.767 MVP1.0010.989–1.0130.859 Compliance1.0000.989–1.0110.981 Detrusor overactivity1.0710.401–2.8620.891 Schafer1.0900.736–1.6140.668 First desire to void1.0030.996–1.0090.433 MCC1.0020.998–1.0060.454 Residual volume1.0030.998–1.0080.220

13. Table 8. Predictive factors for incontinence at the next day of catheter removal after HoLEP in experienced surgeons HoLEP, holmium laser enucleation of the prostate; CI, confidence interval; IPSS, International Prostate Symptom Score; MVP, maximum voiding pressure; MCC, maximum cystometric capacity. *P<0.05, statistical significance. International Neurourology Journal 2016;20:59-68 HoLEP, holmium laser enucleation of the prostate; CI, confidence interval; IPSS, International Prostate Symptom Score; MVP, maximum voiding pressure; MCC, maximum cystometric capacity. *P<0.05, statistical significance. Variable UnivariateMultivariate Odds ratio95% CIP-valueOdds ratio95% CIP-value Age1.0670.999–1.1390.053 Preoperative IPSS0.9950.925–1.0720.905 Quality of life0.7750.405–1.4840.442 Operation time1.0161.007–1.0250.001 * 1.0040.987–1.0220.625 Enucleation time1.0231.011–1.0360.000 * 1.0170.994–1.0410.152 Morcellation time1.0170.999–1.0360.071 Mentorship0.60.425–1.0240.979 Resected prostate weight1.0110.999–1.0230.062 Prostate volume1.0091.000–1.0190.060 MVP1.0030.991–1.0150.612 Compliance0.9880.968–1.0080.242 Detrusor overactivity3.2081.288–7.9920.012 * 2.6240.964–7.1380.059 Schafer1.0520.743–1.4870.776 First desire to void1.0040.997–1.0100.236 MCC10.997–1.0040.773 Residual volume10.998–1.0030.747

14. Table 9. Predictive factors for incontinence at 1 month after HoLEP in experienced surgeons HoLEP, holmium laser enucleation of the prostate; CI, confidence interval; IPSS, International Prostate Symptom Score; MVP, maximum voiding pressure; MCC, maximum cystometric capacity. *P<0.05, statistical significance. International Neurourology Journal 2016;20:59-68 HoLEP, holmium laser enucleation of the prostate; CI, confidence interval; IPSS, International Prostate Symptom Score; MVP, maximum voiding pressure; MCC, maximum cystometric capacity. *P<0.05, statistical significance. Variable UnivariateMultivariate Odds ratio95% CIP-valueOdds ratio95% CIP-value Age0.9900.930–1.0530.741 Preoperative IPSS1.0170.948–1.0920.632 Quality of life1.1730.623–2.2100.621 Operation time1.0000.993–1.0080.926 Enucleation time1.0040.994–1.0140.416 Morcellation time0.9920.972–1.0130.465 Mentorship0.7330.468–1.1490.979 Resected prostate weight0.9950.984–1.0070.454 Prostate volume0.9970.987–1.0070.528 MVP1.0060.994–1.0190.320 Compliance1.0050.987–1.0230.578 Detrusor overactivity1.7050.692–4.2040.246 Schafer1.0980.771–1.5620.605 First desire to void1.0091.002–1.0170.012 * MCC1.0020.999–1.0050.243 Residual volume1.0000.997–1.0030.877

15. Table 10. Predictive factors for incontinence at 3 months after HoLEP in experienced surgeons HoLEP, holmium laser enucleation of the prostate; CI, confidence interval; IPSS, International Prostate Symptom Score; MVP, maximum voiding pressure; MCC, maximum cystometric capacity. *P<0.05, statistical significance. International Neurourology Journal 2016;20:59-68 HoLEP, holmium laser enucleation of the prostate; CI, confidence interval; IPSS, International Prostate Symptom Score; MVP, maximum voiding pressure; MCC, maximum cystometric capacity. *P<0.05, statistical significance. Variable UnivariateMultivariate Odds ratio95% CIP-valueOdds ratio95% CIP-value Age0.9560.873–1.0480.335 Preoperative IPSS0.9770.881–1.0830.658 Quality of life1.2610.485–3.2800.634 Operation time0.9900.977–1.0030.123 Enucleation time0.9840.966–1.0030.096 Morcellation time0.9940.965–1.0250.709 Mentorship0.1670.088–0.3160.981 Resected prostate weight0.9910.971–1.0110.372 Prostate volume0.9940.977–1.0100.451 MVP0.9880.969–1.0070.216 Compliance1.0030.979–1.0270.795 Detrusor overactivity0.9680.269–3.4820.960 Schafer0.7180.427–1.2080.212 First desire to void0.9950.985–1.0050.343 MCC0.9950.989–1.0020.166 Residual volume0.9960.990–1.0030.300