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:This study investigated the independent risk factors for lymph node metastasis（LNM）in high-risk prostate cancer（HRPCa）patients undergoing robot-assisted radical prostatectomy（RARP），and constructed a nomogram model based on clinical data to improve the accuracy and clinical practicality of preoperative prediction of LNM.Methods:A retrospective analysis was conducted on the clinical data of 218 HRPCa patients who received RARP treatment at the First Medical Center of the PLA General Hospital from January 2020 to March 2025 as the modeling group. The age of the modeling group was（66.91±6.94）years old. 75 cases（34.40%）had a history of smoking，and 48 cases（22.02%）had a history of drinking. There were a body mass index（BMI）of 25.55（23.58，27.00）kg/m 2，a total prostate-specific antigen（tPSA）of 20.59（10.42，30.61）ng/ml，a free prostate-specific antigen（fPSA）of 1.87（1.04，3.26）ng/ml，a prostate volume（PV）of（41.19±21.00）ml，a prostate-specific antigen density（PSAD）of 0.52（0.30，0.84）ng/ml 2. Among the patients，60 cases（27.52%）had a preoperative biopsy Gleason score >8，and the percentage of positive biopsy cores（PPBC）was 50%（31%，80%）. Thirty-one patients（14.22%）were staged clinically as >T 2c. The diagnostic criteria for high-risk prostate cancer（HRPCa）were defined as meeting any one of the following：PSA >20 ng/ml，Gleason score on prostate biopsy ≥8，or clinical stage ≥T 3. Among the 218 patients in the modeling cohort，67 cases（30.73%）met two of the criteria，and 7 cases（3.21%）met all three criteria. All 218 patients underwent RARP，and based on postoperative pathology，they were divided into the LNM group and the non-LNM group. The relationship between the number of diagnostic criteria met and the occurrence of LNM was analyzed. An external validation cohort included 42 HRPCa patients who underwent RARP at the Third，Fifth Medical Centers of the PLA General Hospital between January 2023 and May 2025. Their mean age was（66.79±5.92）years. Eighteen patients（42.86%）had a smoking history，and nine（21.43%）had a history of alcohol consumption. The median BMI was 26.00（23.80，27.13）kg/m 2. The median tPSA level was 17.34（8.97，27.30）ng/ml. The median fPSA was 1.51（0.83，2.52）ng/ml，and the median PV was（35.57 ± 15.25）ml. The median PSAD was 0.57（0.23，0.87）ng/ml 2，and the median PPBC was 58%（36%，71%）. Three patients（7.14%）had a clinical stage >T 2c，and 12 patients（28.57%）had a Gleason score >8 on preoperative biopsy. Univariate and multivariate binary logistic regression analyses were used to identify independent risk factors for LNM，and a nomogram model was constructed based on these factors. The predictive performance of the model was evaluated using receiver operating characteristic（ROC）curves and calibration plots，and the model was validated in the external cohort. Result:According to postoperative pathology，45 patients were classified into the LNM group，and 173 into the non-LNM group. The probability of LNM increased proportionally with the number of diagnostic criteria met for HRPCa（meeting two criteria： OR = 4.762，95% CI 2.323-9.761， P < 0.01；meeting three criteria： OR = 10.667，95% CI 2.187-52.025， P=0.003）. Binary logistic regression analysis revealed that age（ OR=0.913，95% CI 0.859-0.971， P = 0.004），tPSA（ OR=1.039，95% CI 1.018-1.061， P<0.01），PPBC（ OR = 5.656，95% CI 1.101-29.056， P = 0.038），and clinical T stage（T 2c stage： OR=2.945，95% CI 0.888-9.769， P=0.077；>T 2c stage OR = 18.351，95% CI 4.790-70.306， P < 0.01）were independent risk factors for postoperative LNM in HRPCa patients after RARP. The ROC curve of the nomogram model based on these factors showed an area under the curve（AUC）of 0.853（95% CI 0.790-0.917）. In the external validation cohort，the nomogram achieved an AUC of 0.743（95% CI 0.556-0.929）. The calibration plots demonstrated good agreement between the predicted probabilities and actual observations. Conclusions:Age，tPSA，PPBC，and clinical T stage were independent predictors of postoperative LNM in HRPCa patients undergoing RARP. The greater the number of HRPCa diagnostic criteria met，the higher the likelihood of postoperative LNM. The nomogram developed in this study could effectively predict the risk of LNM in HRPCa patients after RARP.

Urinary incontinence is a common complication after radical prostatectomy，which seriously affects the quality of life of patients. As a simple and convenient reconstruction technique，the anterior suspension stitch technique can improve the early recovery of urinary continence by providing anterior support and stabilizing the urethral position. This article will review the proposal，innovative development of this technique and the application of the emerging suspension stitch technique in radical prostatectomy.

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:This study investigated the independent risk factors for lymph node metastasis（LNM）in high-risk prostate cancer（HRPCa）patients undergoing robot-assisted radical prostatectomy（RARP），and constructed a nomogram model based on clinical data to improve the accuracy and clinical practicality of preoperative prediction of LNM.Methods:A retrospective analysis was conducted on the clinical data of 218 HRPCa patients who received RARP treatment at the First Medical Center of the PLA General Hospital from January 2020 to March 2025 as the modeling group. The age of the modeling group was（66.91±6.94）years old. 75 cases（34.40%）had a history of smoking，and 48 cases（22.02%）had a history of drinking. There were a body mass index（BMI）of 25.55（23.58，27.00）kg/m 2，a total prostate-specific antigen（tPSA）of 20.59（10.42，30.61）ng/ml，a free prostate-specific antigen（fPSA）of 1.87（1.04，3.26）ng/ml，a prostate volume（PV）of（41.19±21.00）ml，a prostate-specific antigen density（PSAD）of 0.52（0.30，0.84）ng/ml 2. Among the patients，60 cases（27.52%）had a preoperative biopsy Gleason score >8，and the percentage of positive biopsy cores（PPBC）was 50%（31%，80%）. Thirty-one patients（14.22%）were staged clinically as >T 2c. The diagnostic criteria for high-risk prostate cancer（HRPCa）were defined as meeting any one of the following：PSA >20 ng/ml，Gleason score on prostate biopsy ≥8，or clinical stage ≥T 3. Among the 218 patients in the modeling cohort，67 cases（30.73%）met two of the criteria，and 7 cases（3.21%）met all three criteria. All 218 patients underwent RARP，and based on postoperative pathology，they were divided into the LNM group and the non-LNM group. The relationship between the number of diagnostic criteria met and the occurrence of LNM was analyzed. An external validation cohort included 42 HRPCa patients who underwent RARP at the Third，Fifth Medical Centers of the PLA General Hospital between January 2023 and May 2025. Their mean age was（66.79±5.92）years. Eighteen patients（42.86%）had a smoking history，and nine（21.43%）had a history of alcohol consumption. The median BMI was 26.00（23.80，27.13）kg/m 2. The median tPSA level was 17.34（8.97，27.30）ng/ml. The median fPSA was 1.51（0.83，2.52）ng/ml，and the median PV was（35.57 ± 15.25）ml. The median PSAD was 0.57（0.23，0.87）ng/ml 2，and the median PPBC was 58%（36%，71%）. Three patients（7.14%）had a clinical stage >T 2c，and 12 patients（28.57%）had a Gleason score >8 on preoperative biopsy. Univariate and multivariate binary logistic regression analyses were used to identify independent risk factors for LNM，and a nomogram model was constructed based on these factors. The predictive performance of the model was evaluated using receiver operating characteristic（ROC）curves and calibration plots，and the model was validated in the external cohort. Result:According to postoperative pathology，45 patients were classified into the LNM group，and 173 into the non-LNM group. The probability of LNM increased proportionally with the number of diagnostic criteria met for HRPCa（meeting two criteria： OR = 4.762，95% CI 2.323-9.761， P < 0.01；meeting three criteria： OR = 10.667，95% CI 2.187-52.025， P=0.003）. Binary logistic regression analysis revealed that age（ OR=0.913，95% CI 0.859-0.971， P = 0.004），tPSA（ OR=1.039，95% CI 1.018-1.061， P<0.01），PPBC（ OR = 5.656，95% CI 1.101-29.056， P = 0.038），and clinical T stage（T 2c stage： OR=2.945，95% CI 0.888-9.769， P=0.077；>T 2c stage OR = 18.351，95% CI 4.790-70.306， P < 0.01）were independent risk factors for postoperative LNM in HRPCa patients after RARP. The ROC curve of the nomogram model based on these factors showed an area under the curve（AUC）of 0.853（95% CI 0.790-0.917）. In the external validation cohort，the nomogram achieved an AUC of 0.743（95% CI 0.556-0.929）. The calibration plots demonstrated good agreement between the predicted probabilities and actual observations. Conclusions:Age，tPSA，PPBC，and clinical T stage were independent predictors of postoperative LNM in HRPCa patients undergoing RARP. The greater the number of HRPCa diagnostic criteria met，the higher the likelihood of postoperative LNM. The nomogram developed in this study could effectively predict the risk of LNM in HRPCa patients after RARP.

Urinary incontinence is a common complication after radical prostatectomy，which seriously affects the quality of life of patients. As a simple and convenient reconstruction technique，the anterior suspension stitch technique can improve the early recovery of urinary continence by providing anterior support and stabilizing the urethral position. This article will review the proposal，innovative development of this technique and the application of the emerging suspension stitch technique in radical prostatectomy.

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 effect of total anatomical reconstruction (TAR) during robot-assisted radical prostatectomy (RARP) .Methods:The clinical data of 99 patients with RARP performed by a single doctor in our hospital from January 2018 to January 2021 were analyzed retrospectively.There were 38 patients in the TAR+ vesicourethral anastomosis (VUA) group and 61 patients in the VUA group. There were no significant differences between the two groups in the age of patients [ 65.5 (60.8, 71.0) years vs. 66.0 (61.5, 69.0) years], body mass index[ (24.92±2.65) kg/m 2 vs. (25.51±2.80) kg/m 2], prostate volume [28.13 (25.21, 36.53) ml vs. 26.33 (19.75, 47.84) ml], PSA [15.67 (9.02, 31.49) ng/ml vs. 14.58 (9.23, 30.06) ng/ml], neoadjuvant therapy [50.0% (19/38) vs. 63.9% (39/61)], Gleason score (6/7/8/9-10 scores: 8/16/5/9 cases vs. 16/25/9/11 cases) and clinical T stage (T 1/T 2/T 3 stage: 4/29/5 cases vs. 3/53/5 cases)(all P>0.05). The TAR technique was performed as follows. ①The two layers of posterior reconstruction involved the residual Denonvilliers fascia, the striated sphincter and medial dorsal raphe (MDR), and the vesicoprostatic muscle (VPM), the fascia which was 1-2 cm from the cranial side of the bladder neck and MDR. ②The one layer of anterior reconstruction involved detrusor apron, tissues around the urethra and the visceral and parietal layers of the endoplevic fascia. The VUA technique was suturing the bladder neck and urethra consecutively. Perioperative indexes were compared between the two groups. Results:All 99 operations were successfully completed. There were no statistically significant differences between the TAR+ VUA and VUA groups in operation time [ (174.16±47.21) min vs. (188.70±45.39) min], blood loss [ 50 (50, 100) ml vs. 100 (50, 100) ml], incidence of postoperative complications [10.5% (4/38) vs. 14.8% (9/61)], phathological T stage [pT 2/pT 3~4 stage: 25/12 cases vs. 42/19 cases, P=0.895], and the time of indwelling catheter [ 21.0 (19.0, 21.0) d vs. 21.0 (21.0, 21.0) d] (all P>0.05). The difference in postoperative length of stay between the two groups was statistically significant[6.0 (5.0, 6.0) d vs. 7.0 (6.0, 7.5)d, P<0.001]. Follow-up was performed for 1 year after surgery. The recovery rate of urinary continence 3 months after surgery in TAR+ VUA and VUA groups were 86.8% (33/38) vs. 65.6% (40/61), which were statistically significant( P=0.019). There were no significant differences between TAR+ VUA and VUA groups in recovery rate of urinary continence 1 months after surgery [47.4% (18/38) vs. 45.9% (28/61)], 6 months after surgery [94.7% (36/38) vs. 85.2% (52/61)], and 12 months after surgery [94.7% (36/38) vs. 93.4% (57/61)] (all P>0.05). Conclusions:TAR technique has good surgical safety, and can promote recovery of early urinary continence after RARP.

Objective:This study aimed to investigate the physical properties, biocompatibility, and 3D printing performance of a novel hybrid bioink composed of gelatin methacrylated (GelMA) and chitin nanocrystal (ChiNC).Methods:The study was conducted from May 2021 to December 2022, four different bioinks were prepared by adding varying amounts of ChiNC to GelMA bioink. The GelMA concentration in all four bioinks was 100 mg/ml, while the ChiNC concentrations were 0 mg/ml (no ChiNC added), 5 mg/ml, 10 mg/ml, and 20 mg/ml, respectively, named as GC0, GC5, GC10, and GC20 bioinks. The cross-sectional morphology of the hydrogels formed after photocuring the four bioinks was observed using scanning electron microscopy, and the porosity was calculated. Weighing the hydrogels before and after swelling, and then calculate the equilibrium swelling rate. HUVECs were seeded on the surfaces of the hydrogels prepared from the four bioinks and cultured in medium. Cell proliferation was assessed using CCK-8 assays at 1d, 3d, and 7d to compare the proliferation rates of cells on the four hydrogels. HUVECs were added to the four bioinks, and grid-like scaffolds were printed and cultured in medium. Live-Dead staining was performed at 1d and 7d to observe cell viability. Compare the printing effect of bioinks by observing its forming continuous threads properties during extrusion. Finally, tissue-engineered bladder patches simulating the mucosal layer, submucosal layer, and muscular layer anatomical structures of the bladder wall were 3D bioprinted using the optimized bioink composition, and the stability and fidelity of the printed structures were observed to further validate the feasibility of printing multi-layered complex structures with the bioink.Results:Scanning electron microscopy revealed that the porosity of the GC0, GC5, GC10, and GC20 hydrogels were (51.43±6.23)%, (51.85±6.47)%, (50.55±4.59)%, and (42.49±2.20)%, respectively. The differences in porosity between the GC0 group and the other three groups were not statistically significant ( P=0.9994, P=0.9948, P=0.1200). The equilibrium swelling ratio of the other three groups [(8.81±0.41), (7.95±0.19), (7.71±0.14)] was significantly lower than that of the GC0 group (9.37 ± 0.49), and the differences were statistically significant ( P=0.0457, P<0.01, P<0.01). CCK-8 assay showed no significant difference in absorbance value between the GC10 group (0.360±0.009) and the GC0 group (0.357±0.007), GC5 group (0.350±0.012), and GC20 group (0.345±0.018) on the first day ( P=0.9332, P=0.5464, P=0.4937). However, on the third day, the absorbance value of the GC10 group (0.755±0.012) was significantly higher than that of the GC0 group (0.634±0.010), GC5 group (0.704±0.009), and GC20 group (0.653±0.015) ( P<0.01, P=0.0033, P=0.0002). On the seventh day, the absorbance value of the GC10 group (1.001±0.031) was significantly higher than that of the GC0 group (0.846±0.026), GC5 group (0.930±0.043), and GC20 group (0.841±0.024)( P=0.0012, P=0.1390, P=0.0010). The addition of human umbilical vein endothelial cells (HUVECs) into the four groups of hydrogels enabled the printing of grid-like scaffolds, and Live-Dead staining was performed on day 1 and day 7. The cell viability of HUVECs in the four groups on day 1 was (90.13±1.63)%, (90.6±2.45)%, (92.58±2.15)%, and (91.40±3.17)%, respectively. There were no statistically significant differences between the GC0 group and the other three groups ( P=0.9869, P=0.3093, P=0.8008). On day 7, the cell viability was (89.97±3.10)%, (92.18±2.21)%, (92.05±2.25)%, and (90.12±1.97)% for the four groups, respectively. There were no statistically significant differences between the GC0 group and the other three groups ( P=0.3965, P=0.4511, P=0.9995). Bioink extrusion test showed that the GC0 hydrogel could be extruded continuously and form threads at temperatures between 24℃ and 25℃, while the GC10 hydrogel could be extruded continuously and form threads at temperatures between 24℃ and 27℃. Printing tissue engineered bladder patches simulating the anatomical structure of the bladder mucosal layer, submucosal layer, and muscular layer using GC10 bioink, and the printed patches were stable, without collapse, and had high fidelity. Conclusions:Adding ChiNC to GelMA promotes cell adhesion, proliferation, and expands the printing window of GelMA bioink. The biocompatibility of the mixed bioink prepared by adding 10 mg/ml ChiNC in GelMA is good, capable of printing tissue-engineered bladder patches that mimic the anatomical structure of natural bladder walls.