Objective:To investigate the correlation between membranous urethral length (MUL) and early urinary continence recovery after robot-assisted radical prostatectomy (RARP).Methods:A retrospective analysis was conducted on 71 prostate cancer patients who underwent RARP by a single surgeon at the PLA General Hospital between January 2020 and December 2023. Patient characteristics included: age of (65.32±6.04) years, BMI (25.21 ± 2.59) kg/m 2, prostate volume 32.41 (24.75, 44.40) ml, PSA 11.67 (8.22, 22.66) ng/ml. Gleason score [6/7/8/9-10: 15 (21.2%)/29 (40.8%)/16 (22.5%)/11 (15.5%)], Clinical stage [cT 1/cT 2/cT 3: 4 (5.6%)/61 (85.9%)/6 (8.5%)]. Measured MUL using multiparametric prostate MRI, median MUL was 13.25 (10.41-14.99) mm. Neurovascular bundle (NVB) preservation in 13 (18.3%) cases. Patients were grouped based on continence recovery at 1 and 3 months post-catheter removal. Age, BMI, prostate volume, PSA, Gleason score, clinical stage, NVB preservation, pathological stage, catheter indwelling time, and MUL were compared between groups. Multivariate analysis identified independent predictors of continence recovery. Results:All 71 surgeries were successful, pathological stage [pT 2/pT 3-4: 47 (66.2%)/24 (33.8%)], and catheter indwelling time 2.7 (2.0, 3.0) weeks. Follow-up data at 2 months were available for 71 patients, at 1 month, 42 patients achieved continence (continence group) and 29 had incontinence (incontinence group).No significant differences were observed between continence and incontinence groups in age [(64.93±6.48)years vs. (65.79±5.89) years], BMI [(26.26±2.52)kg/m 2 vs. (24.52±2.42) kg/m 2], prostate volume [32.00 (24.12, 41.11)ml vs. 33.00 (25.27, 47.97) ml], PSA [12.55 (8.31, 24.00) ng/ml vs. 11.30 (7.92, 20.65) ng/ml], Gleason score [6/7/8/9-10: 6 (14.2%)/18 (42.9%)/12 (28.6%)/6 (14.3%) vs. 9 (31.0%)/11 (37.9%)/4 (13.8%)/5 (17.3%)], clinical stage [cT 1/cT 2/cT 3: 2 (4.8%)/35 (83.3%)/5 (11.9%) vs. 2 (6.9%)/26 (89.7%)/1 (3.4%)], NVB preservation [7 (16.7%) vs. 6 (20.7%)], pathological stage [pT 2/pT 3-4: 27 (64.3%)/15 (35.7%) vs. 20 (69.0%)/9 (31.0%)], or catheter indwelling time [2.6(2.0, 3.0) weeks vs. 2.9 (2.0, 3.4) weeks]. However, MUL was significantly longer in the continence group [13.77 (11.70, 15.32) mm vs. 10.32 (9.65, 13.57) mm, P<0.01]. Follow-up data at 3 months were available for 69 patients, At 3 months, 61 patients achieved continence (continence group) and 8 remained incontinent (incontinence group). No significant differences were observed in age [(64.89±6.25)years vs. (68.13±4.09) years], BMI [(25.34±2.64)kg/m 2 vs. (24.36±2.49) kg/m 2], prostate volume [32.41 (24.44, 44.16)ml vs. 36.13 (27.48, 48.26) ml], PSA [12.50 (8.28, 22.76)ng/ml vs. 13.34 (5.88, 23.39) ng/ml], Gleason score [6/7/8/9-10: 12 (19.7%)/25 (41.0%)/14 (23.0%)/10 (16.3%) vs. 3 (37.5%)/3 (37.5%)/2 (25.0%)/0], clinical stage [cT 1/cT 2/cT 3: 3 (4.9%)/52 (85.2%)/6 (9.8%) vs. 1 (12.5%)/7 (87.5%)/0], NVB preservation [9 (14.8%) vs. 3 (37.5%)], pathological stage [pT 2/pT 3-4: 41 (67.2%)/20 (32.8%) vs. 5 (62.5%)/9 (31.0%)], or catheter indwelling time [2.7(2.0, 3.0)weeks vs. 3.0 (2.3, 3.7) weeks]. MUL remained significantly longer in the continence group [13.57 (10.57, 15.10)mm vs. 10.12 (9.36, 10.42) mm, P=0.002]. Multivariate logistic regression incorporating age, BMI, prostate volume, MUL, NVB preservation, and catheter indwelling time identified MUL as an independent protective factor for continence recovery at both 1 month [ OR=0.62, 95 CI 0.49-0.79, P<0.01] and 3 months [ OR=0.61, 95 CI 0.41-0.92, P=0.017]. Conclusions:MUL is independently associated with early urinary continence recovery after RARP, serving as a protective predictor at both 1 and 3 months after catheter removal.

Objective:To investigate the risk factors for positive surgical margins（PSM）after robot-assisted radical prostatectomy（RARP），and to develop and validate a predictive nomogram.Methods:We retrospectively analyzed the clinicopathological data of 874 prostate cancer patients who underwent RARP performed by a single surgeon at the First Medical Center of Chinese PLA General Hospital between January 2012 and December 2018. Patients were divided into positive surgical margin（n=327）and negative surgical margin（n=547）groups based on postoperative margin status.The PSM group had significantly higher preoperative median tPSA［31.200（19.050，54.400）ng/ml vs. 15.050（9.840，27.590）ng/ml， P<0.01］，higher proportion of patients with PSAD>1 ng/ml 2［49.5%（162/327）vs. 21.2%（116/547）， P<0.01］，biopsy Gleason score ≥8［33.3%（109/327）vs. 21.2%（116/547）， P<0.01］，ISUP grade 4-5［33.3%（109/327）vs. 21.2%（116/547）， P<0.01］，clinical T stage ≥cT 3［11.3%（37/327）vs. 4.2%（23/547）， P<0.01］，and high-risk classification［82.3%（269/327）vs. 55.9%（306/547）， P<0.01］compared to the negative surgical margin group. Conversely，the PSM group had a lower prevalence of hypertension［29.7%（97/327）vs. 40.2%（220/547）， P=0.002］.Patients were randomly split into a training cohort（n=656，75%）and an internal validation cohort（n=218，25%）. An external validation cohort included 71 patients who underwent RARP by different surgeons between January 2014 and December 2016. No significant differences in baseline characteristics were observed between cohorts（ P>0.05）.Univariate and multivariate logistic regression analyses identified independent predictors of PSM，which were incorporated into a nomogram. Predictive performance was assessed using receiver operating characteristic（ROC）curves，decision curve analysis（DCA），and calibration curve. Internal and external validations were performed. Results:The PSM group had longer postoperative hospitalization［6（5，8）vs. 6（5，7）days， P=0.028］，higher rates of pathologic Gleason score ≥8［41.5%（115/277）vs. 24.9%（111/446）， P<0.01］，ISUP grade 4-5［41.5%（115/277）vs. 24.9%（111/446）， P<0.01］，pT 3 stage［52.3%（171/327）vs. 17.4%（95/547）， P<0.01］，pN 1 stage［12.8%（42/327）vs. 3.8%（21/547）， P<0.01］，extracapsular extension［52.3%（171/327）vs. 17.4%（95/547）， P<0.01］，and seminal vesicle invasion［34.6%（113/327）vs. 9.1%（50/547）， P<0.01］.Multivariate analysis identified elevated tPSA（ OR=1.014，95% CI 1.004—1.024，P=0.006）and PSAD ≥0.15 ng/（ml/g）（ OR=11.638，95% CI 1.450—93.396，P=0.021）as independent risk factors for PSM. The area under the ROC curve（AUC）of the nomogram constructed based on the above variables was 0.770（95% CI 0.735—0.805）. The AUC values for the internal and external validation sets were 0.698（95% CI 0.630—0.767）and 0.643（95% CI 0.513—0.774），respectively. The calibration curve demonstrated good agreement between the predicted and observed outcomes，and the DCA indicated that the predictive model has potential clinical utility in decision-making. Conclusion:tPSA and PSAD were identified as independent risk factors for PSM. The nomogram constructed based on these two independent predictive variables effectively predicted PSM after RARP.

Objective:To investigate the correlation between membranous urethral length (MUL) and early urinary continence recovery after robot-assisted radical prostatectomy (RARP).Methods:A retrospective analysis was conducted on 71 prostate cancer patients who underwent RARP by a single surgeon at the PLA General Hospital between January 2020 and December 2023. Patient characteristics included: age of (65.32±6.04) years, BMI (25.21 ± 2.59) kg/m 2, prostate volume 32.41 (24.75, 44.40) ml, PSA 11.67 (8.22, 22.66) ng/ml. Gleason score [6/7/8/9-10: 15 (21.2%)/29 (40.8%)/16 (22.5%)/11 (15.5%)], Clinical stage [cT 1/cT 2/cT 3: 4 (5.6%)/61 (85.9%)/6 (8.5%)]. Measured MUL using multiparametric prostate MRI, median MUL was 13.25 (10.41-14.99) mm. Neurovascular bundle (NVB) preservation in 13 (18.3%) cases. Patients were grouped based on continence recovery at 1 and 3 months post-catheter removal. Age, BMI, prostate volume, PSA, Gleason score, clinical stage, NVB preservation, pathological stage, catheter indwelling time, and MUL were compared between groups. Multivariate analysis identified independent predictors of continence recovery. Results:All 71 surgeries were successful, pathological stage [pT 2/pT 3-4: 47 (66.2%)/24 (33.8%)], and catheter indwelling time 2.7 (2.0, 3.0) weeks. Follow-up data at 2 months were available for 71 patients, at 1 month, 42 patients achieved continence (continence group) and 29 had incontinence (incontinence group).No significant differences were observed between continence and incontinence groups in age [(64.93±6.48)years vs. (65.79±5.89) years], BMI [(26.26±2.52)kg/m 2 vs. (24.52±2.42) kg/m 2], prostate volume [32.00 (24.12, 41.11)ml vs. 33.00 (25.27, 47.97) ml], PSA [12.55 (8.31, 24.00) ng/ml vs. 11.30 (7.92, 20.65) ng/ml], Gleason score [6/7/8/9-10: 6 (14.2%)/18 (42.9%)/12 (28.6%)/6 (14.3%) vs. 9 (31.0%)/11 (37.9%)/4 (13.8%)/5 (17.3%)], clinical stage [cT 1/cT 2/cT 3: 2 (4.8%)/35 (83.3%)/5 (11.9%) vs. 2 (6.9%)/26 (89.7%)/1 (3.4%)], NVB preservation [7 (16.7%) vs. 6 (20.7%)], pathological stage [pT 2/pT 3-4: 27 (64.3%)/15 (35.7%) vs. 20 (69.0%)/9 (31.0%)], or catheter indwelling time [2.6(2.0, 3.0) weeks vs. 2.9 (2.0, 3.4) weeks]. However, MUL was significantly longer in the continence group [13.77 (11.70, 15.32) mm vs. 10.32 (9.65, 13.57) mm, P<0.01]. Follow-up data at 3 months were available for 69 patients, At 3 months, 61 patients achieved continence (continence group) and 8 remained incontinent (incontinence group). No significant differences were observed in age [(64.89±6.25)years vs. (68.13±4.09) years], BMI [(25.34±2.64)kg/m 2 vs. (24.36±2.49) kg/m 2], prostate volume [32.41 (24.44, 44.16)ml vs. 36.13 (27.48, 48.26) ml], PSA [12.50 (8.28, 22.76)ng/ml vs. 13.34 (5.88, 23.39) ng/ml], Gleason score [6/7/8/9-10: 12 (19.7%)/25 (41.0%)/14 (23.0%)/10 (16.3%) vs. 3 (37.5%)/3 (37.5%)/2 (25.0%)/0], clinical stage [cT 1/cT 2/cT 3: 3 (4.9%)/52 (85.2%)/6 (9.8%) vs. 1 (12.5%)/7 (87.5%)/0], NVB preservation [9 (14.8%) vs. 3 (37.5%)], pathological stage [pT 2/pT 3-4: 41 (67.2%)/20 (32.8%) vs. 5 (62.5%)/9 (31.0%)], or catheter indwelling time [2.7(2.0, 3.0)weeks vs. 3.0 (2.3, 3.7) weeks]. MUL remained significantly longer in the continence group [13.57 (10.57, 15.10)mm vs. 10.12 (9.36, 10.42) mm, P=0.002]. Multivariate logistic regression incorporating age, BMI, prostate volume, MUL, NVB preservation, and catheter indwelling time identified MUL as an independent protective factor for continence recovery at both 1 month [ OR=0.62, 95 CI 0.49-0.79, P<0.01] and 3 months [ OR=0.61, 95 CI 0.41-0.92, P=0.017]. Conclusions:MUL is independently associated with early urinary continence recovery after RARP, serving as a protective predictor at both 1 and 3 months after catheter removal.

Objective:To investigate the risk factors for positive surgical margins（PSM）after robot-assisted radical prostatectomy（RARP），and to develop and validate a predictive nomogram.Methods:We retrospectively analyzed the clinicopathological data of 874 prostate cancer patients who underwent RARP performed by a single surgeon at the First Medical Center of Chinese PLA General Hospital between January 2012 and December 2018. Patients were divided into positive surgical margin（n=327）and negative surgical margin（n=547）groups based on postoperative margin status.The PSM group had significantly higher preoperative median tPSA［31.200（19.050，54.400）ng/ml vs. 15.050（9.840，27.590）ng/ml， P<0.01］，higher proportion of patients with PSAD>1 ng/ml 2［49.5%（162/327）vs. 21.2%（116/547）， P<0.01］，biopsy Gleason score ≥8［33.3%（109/327）vs. 21.2%（116/547）， P<0.01］，ISUP grade 4-5［33.3%（109/327）vs. 21.2%（116/547）， P<0.01］，clinical T stage ≥cT 3［11.3%（37/327）vs. 4.2%（23/547）， P<0.01］，and high-risk classification［82.3%（269/327）vs. 55.9%（306/547）， P<0.01］compared to the negative surgical margin group. Conversely，the PSM group had a lower prevalence of hypertension［29.7%（97/327）vs. 40.2%（220/547）， P=0.002］.Patients were randomly split into a training cohort（n=656，75%）and an internal validation cohort（n=218，25%）. An external validation cohort included 71 patients who underwent RARP by different surgeons between January 2014 and December 2016. No significant differences in baseline characteristics were observed between cohorts（ P>0.05）.Univariate and multivariate logistic regression analyses identified independent predictors of PSM，which were incorporated into a nomogram. Predictive performance was assessed using receiver operating characteristic（ROC）curves，decision curve analysis（DCA），and calibration curve. Internal and external validations were performed. Results:The PSM group had longer postoperative hospitalization［6（5，8）vs. 6（5，7）days， P=0.028］，higher rates of pathologic Gleason score ≥8［41.5%（115/277）vs. 24.9%（111/446）， P<0.01］，ISUP grade 4-5［41.5%（115/277）vs. 24.9%（111/446）， P<0.01］，pT 3 stage［52.3%（171/327）vs. 17.4%（95/547）， P<0.01］，pN 1 stage［12.8%（42/327）vs. 3.8%（21/547）， P<0.01］，extracapsular extension［52.3%（171/327）vs. 17.4%（95/547）， P<0.01］，and seminal vesicle invasion［34.6%（113/327）vs. 9.1%（50/547）， P<0.01］.Multivariate analysis identified elevated tPSA（ OR=1.014，95% CI 1.004—1.024，P=0.006）and PSAD ≥0.15 ng/（ml/g）（ OR=11.638，95% CI 1.450—93.396，P=0.021）as independent risk factors for PSM. The area under the ROC curve（AUC）of the nomogram constructed based on the above variables was 0.770（95% CI 0.735—0.805）. The AUC values for the internal and external validation sets were 0.698（95% CI 0.630—0.767）and 0.643（95% CI 0.513—0.774），respectively. The calibration curve demonstrated good agreement between the predicted and observed outcomes，and the DCA indicated that the predictive model has potential clinical utility in decision-making. Conclusion:tPSA and PSAD were identified as independent risk factors for PSM. The nomogram constructed based on these two independent predictive variables effectively predicted PSM after RARP.