Effect of prostatic apex shape (Lee types) and urethral sphincter length in preoperative MRI on very early continence rates after radical prostatectomy

Early Continence Recovery after Robot-Assisted Radical Prostatectomy: A Multicenter Analysis on the Role of Prostatic Shape

Aim: The aim of the study was to investigate the relationship between prostatic apical shape and continence recovery after robot-assisted radical prostatectomy (RARP) in a large multicentric cohort. Materials and Methods: Data of patients who underwent transperitoneal RARP at 10 referral robotic centers between January 2017 and December 2022 were retrospectively analyzed. Patients were stratified into four groups based on the multiparametric magnetic resonance imaging (mpMRI) prostatic apex shape. Pre-, intra-, and postoperative variables were compared. Continence recovery was defined as no pad or 1 safety pad/day. Results: A total of 822 patients were retrieved and classified as Group A (n = 206), Group B (n = 221), Group C (n = 143), and Group D (n = 252) based on the mpMRI. At baseline, statistically significant differences were found in Charlson's comorbidity index (CCI) (p < 0.001), body mass index (BMI) (p = 0.01), prostatic urethral length (p = 0.008), and membranous urethral length (p = 0.03). In terms of bladder neck-sparing technique, a statistically significant difference was found among groups (p = 0.005). Group D achieved continence significantly earlier than the other groups after RARP, with a median recovery time of 3 months (95% confidence interval [CI]: 3-3), compared with 4 months for all other groups (95% CI: 4-4). Group D showed an earlier continence recovery after RARP with respect to all the other shapes (hazard ratio [HR] = 1.23, 95% CI: 1.05-1.43, p = 0.005). The estimated HR remained unchanged after adjusting by age, BMI, CCI, bladder neck-sparing, nerve-sparing, and presence of median lobe (HR = 1.17, 95% CI: 1.00-1.38, p = 0.046). Cox model showed an association with BMI (HR = 0.97, 95% CI: 0.95-0.99, p = 0.03), bladder neck-sparing (HR = 1.45, 95% CI: 1.24-1.70, p < 0.001), and nerve-sparing (HR = 1.27, 95% CI: 1.11-1.46, p = 0.001). Conclusions: Our multi-institutional study confirmed that prostatic apical shape has a significant impact on time-to-continence after RARP.

Technical Modifications Employed in RARP to Improve Early Continence Recovery: A Literature Review

Prostate cancer presents a substantial challenge, necessitating a delicate balance between effective treatment and preserving the overall quality of life for men, while robot-assisted radical prostatectomy (RARP) stands as the premier surgical approach, with a negligible rate of patients who remained incontinent. This review explores various technical modifications employed in RARP to improve early continence recovery, offering a summary of their implementation and potential benefits. Techniques like bladder neck preservation, subapical urethral dissection, and nerve-sparing approaches are critically discussed, highlighting their role in minimizing continence issues and ensuring a better post-operative experience for patients with prostate cancer.

Surgical experience overcomes the impact of prostatic-urethral anatomy on continence recovery after robotic prostatectomy: comprehensive analysis on 366 cases

PURPOSE

To investigate the relationship between a set of prostate-urethral complex (PUC) measurements and incontinence after robot-assisted radical prostatectomy (RARP).

METHODS

The study included data from patients undergoing RARP performed by 2 expert surgeons between 2019 and 2022, with data about preoperative magnetic resonance imaging (MRI) and functional follow-up. Continence status was assessed according to a stringent definition (no PADS used). MRIs were evaluated to calculate prostatic urethral length, membranous urethral length, membranous urethral width, levator ani thickness, and prostate shape. The association of PUC measurements with continence after RARP was studied. Secondarily, we evaluated whether pre-determined cut-off values of PUC measurements could be associated with time to continence. Cumulative hazard incidence analysis was performed by the Nelson-Aalen hazard function. Cumulative incidence hazard curves were built; the Peto-Peto test was used to evaluate the difference among the curves.

RESULTS

366 patients were included. At the 12-month follow-up, 333 patients (90.1%) were continent. Classification of PUC measurements overlapped between continent and noncontinent patients. However, a statistically significant difference was observed for levator ani thickness, greater in continent patients (12.8 mm vs. 11.7; p = 0.02). Multivariable models found BMI as independent predictor of incontinence (HR 1.04, 95% C.I 1.00-1.07, p = 0.04). None of PUC measurements associated with incontinence. Also, cumulative hazard incidence analysis at 3 / 6 / 12-months found no statistically significant difference in PUC measurements.

CONCLUSION

No association was found between anatomical characteristics of PUC and continence or time to continence after RARP performed by proficient surgeons. Our data would suggest that once the surgeon has surpassed the learning curve, anatomical variations do not significantly affect the appropriate and proficient execution of the prostate apex dissection during RARP.

The prostate-gland asymmetry affects the 3- and 12-month continence recovery after RARP in patients with small prostate glands: a single center study

To test the impact of the prostate-gland asymmetry on continence rates, namely 3- and 12-month continence recovery, in prostate cancer (PCa) patients who underwent robot-assisted radical prostatectomy (RARP). Within our institutional database, RARP patients with complete preoperative MRI features and 12 months follow-up were enrolled (2021-2023). The population has been stratified according to the presence or absence of prostate-gland asymmetry (defined as the presence of median lobe or side lobe dominance). Multivariable logistic regression models (LRMs) predicting the continence rate at 3 and 12 months after RARP were fitted in the overall population. Subsequently, the LRMs were repeated in two subgroup analyses based on prostate size (≤ 40 vs > 40 ml). Overall, 248 consecutive RARP patients were included in the analyses. The rate of continence at 3 and 12 months was 69 and 72%, respectively. After multivariable LRM the bladder neck sparing approach (OR 3.15, 95% CI 1.68-6.09, p value < 0.001) and BMI (OR 0.90, 95% CI 0.82-0.97, p = 0.006) were independent predictors of recovery continence at 3 months. The prostate-gland asymmetry independently predicted lower continence rates at 3 (OR 0.33, 95% CI 0.13-0.83, p = 0.02) and 12 months (OR 0.31, 95% CI 0.10-0.90, p = 0.03) in patients with prostate size ≤ 40 ml. The presence of prostate lobe asymmetry negatively affected the recovery of 3- and 12-months continence in prostate glands ≤ 40 mL. These observations should be considered in the preoperative planning and counseling of RARP patients.

What the urologist needs to know before radical prostatectomy: MRI effective support to pre-surgery planning

BACKGROUND

Radical prostatectomy (RP) is recommended in case of localized or locally advanced prostate cancer (PCa), but it can lead to side effects, including urinary incontinence (UI) and erectile dysfunction (ED). Magnetic resonance imaging (MRI) is recommended for PCa diagnosis and staging, but it can also improve preoperative risk-stratification.

PURPOSE

This nonsystematic review aims to provide an overview on factors involved in RP side effects, highlighting anatomical and pathological aspects that could be included in a structured report.

EVIDENCE SYNTHESIS

Considering UI evaluation, MR can investigate membranous urethra length (MUL), prostate volume, the urethral sphincter complex, and the presence of prostate median lobe. Longer MUL measurement based on MRI is linked to a higher likelihood of achieving continence restoration. For ED assessment, MRI and diffusion tensor imaging identify the neurovascular bundle and they can aid in surgery planning. Finally, MRI can precisely describe extra-prostatic extension, prostate apex characteristics and lymph-node involvement, providing valuable preoperative information for PCa treatment.

CONCLUSIONS

Anatomical principals structures involved in RP side effects can be assessed with MR. A standardized MR report detailing these structures could assist urologists in planning optimal and tailored surgical techniques, reducing complications, and improving patients' care.

Membranous urethral length measurement on preoperative MRI to predict incontinence after radical prostatectomy: a literature review towards a proposal for measurement standardization

OBJECTIVES

To investigate the membranous urethral length (MUL) measurement and its interobserver agreement, and propose literature-based recommendations to standardize MUL measurement for increasing interobserver agreement. MUL measurements based on prostate MRI scans, for urinary incontinence risk assessment before radical prostatectomy (RP), may influence treatment decision-making in men with localised prostate cancer. Before implementation in clinical practise, MRI-based MUL measurements need standardization to improve observer agreement.

METHODS

Online libraries were searched up to August 5, 2022, on MUL measurements. Two reviewers performed article selection and critical appraisal. Papers reporting on preoperative MUL measurements and urinary continence correlation were selected. Extracted information included measuring procedures, MRI sequences, population mean/median values, and observer agreement.

RESULTS

Fifty papers were included. Studies that specified the MRI sequence used T2-weighted images and used either coronal images (n = 13), sagittal images (n = 18), or both (n = 12) for MUL measurements. 'Prostatic apex' was the most common description of the proximal membranous urethra landmark and 'level/entry of the urethra into the penile bulb' was the most common description of the distal landmark. Population mean (median) MUL value range was 10.4-17.1 mm (7.3-17.3 mm), suggesting either population or measurement differences. Detailed measurement technique descriptions for reproducibility were lacking. Recommendations on MRI-based MUL measurement were formulated by using anatomical landmarks and detailed descriptions and illustrations.

CONCLUSIONS

In order to improve on measurement variability, a literature-based measuring method of the MUL was proposed, supported by several illustrative case studies, in an attempt to standardize MRI-based MUL measurements for appropriate urinary incontinence risk preoperatively.

CLINICAL RELEVANCE STATEMENT

Implementation of MUL measurements into clinical practise for personalized post-prostatectomy continence prediction is hampered by lack of standardization and suboptimal interobserver agreement. Our proposed standardized MUL measurement aims to facilitate standardization and to improve the interobserver agreement.

KEY POINTS

• Variable approaches for membranous urethral length measurement are being used, without detailed description and with substantial differences in length of the membranous urethra, hampering standardization. • Limited interobserver agreement for membranous urethral length measurement was observed in several studies, while preoperative incontinence risk assessment necessitates high interobserver agreement. • Literature-based recommendations are proposed to standardize MRI-based membranous urethral length measurement for increasing interobserver agreement and improving preoperative incontinence risk assessment, using anatomical landmarks on sagittal T2-weighted images.

Improved early continence following laparoscopic radical prostatectomy: the urethral hammock technique

PURPOSE

To introduce and illustrate a novel urethral reconstruction technique-the 'urethral hammock-technique'-and to assess its impact on early postoperative continence following laparoscopic radical prostatectomy (LRP).

METHODS

119 patients who underwent LRP between January 2020 and May 2022 (hammock group: n = 43, control group: n = 76) were included in the study. The primary outcome was continence (zero pads or max. one security pad) at 1, 3, and 6 months following surgery. Secondary outcomes were operative time, complications, and histological findings. Univariate and multivariate regression analyses were performed to reveal predictors for continence. p values < 0.05 with a two-sided 95%-confidence interval were considered statistically significant.

RESULTS

Baseline characteristics were comparable among both groups. The number of patients achieving complete continence in both the hammock and control groups at various time intervals was: 4 weeks 37.2% (16/43) vs. 19.2% (14/73) (p = 0.047); 3 months 60.5% (26/43) vs. 37.3% (28/75) (p = 0.021) and 6 months 72.1% (31/43) vs. 60.3% (44/73) (p = 0.23), respectively. Adjusting for bladder neck preservation status and age, the hammock technique was a significant predictor for continence for the 4-week (OR 0.33, 95% CI 0.13-0.83, p = 0.019) and 3-month (OR 0.28, 95% CI 0.12-0.66, p = 0.004) interval but not for the 6-month interval (OR 0.64, 95% CI 0.27-1.5, p = 0.31). Operative time, complication rates, time till catheter extraction and histological findings were comparable between both groups (all p > 0.05).

CONCLUSIONS

The hammock technique is a simple and reproducible technique to improve early postoperative continence for at least 3 months following surgery. However, these promising results warrant confirmation through a randomized controlled trial.

Surgical techniques to preserve continence after robot-assisted radical prostatectomy

Radical prostatectomy significantly impacts the inherent anatomy of the male pelvis and the functional mechanisms of urinary continence. Incontinence has a considerable negative influence on the quality of life of patients, as well as their social and psychological wellbeing. Numerous surgical techniques have been demonstrated to support the preservation of continence during robot-assisted radical prostatectomy (RARP). In this in-depth analysis, we give a general summary of the surgical techniques used in RARP and their impact on incontinence rates.

Full functional-length urethral sphincter- and neurovascular bundle preservation improves long-term continence rates after robotic-assisted radical prostatectomy

The objective of the study was to test the impact of implementing standard full functional-length urethral sphincter (FFLU) and neurovascular bundle preservation (NVBP) with intraoperative frozen section technique (IFT) on long-term urinary continence in patients undergoing robotic-assisted radical prostatectomy (RARP). We relied on an institutional tertiary-care database to identify patients who underwent RARP between 01/2014 and 09/2019. Until 10/2017, FFLU was not performed and decision for NVBP was taken without IFT. From 11/2017, FFLU and IFT-guided NVBP was routinely performed in all patients undergoing RARP. Long-term continence (≥ 12 months) was defined as the usage of no or one safety- pad. Uni- and multivariable logistic regression models tested the correlation between surgical approach (standard vs FFLU + NVBP) and long-term continence. Covariates consisted of age, body mass index, prostate volume and extraprostatic extension of tumor. The study cohort consisted of 142 patients, with equally sized groups for standard vs FFLU + NVBP RARP (68 vs 74 patients). Routine FFLU + NVBP implementation resulted in a long-term continence rate of 91%, compared to 63% in standard RARP (p < 0.001). Following FFLU + NVBP RARP, 5% needed 1-2, 4% 3-5 pads/24 h and no patient (0%) suffered severe long-term incontinence (> 5 pads/24 h). No significant differences in patient or tumor characteristics were recorded between both groups. In multivariable logistic regression models, FFLU + NVBP was a robust predictor for continence (Odds ratio [OR]: 7.62; 95% CI 2.51-27.36; p < 0.001). Implementation of FFLU and NVBP in patients undergoing RARP results in improved long-term continence rates of 91%.

A standardized method to measure the membranous urethral length (MUL) on MRI of the prostate with high inter- and intra-observer agreement

OBJECTIVES

The membranous urethral length (MUL), defined as the length between the apex and penile base as measured on preoperative prostate magnetic resonance imaging (MRI), is an important predictor for urinary incontinence after radical prostatectomy. Literature on inter- and intra - observer agreement of MUL measurement is limited. We studied the inter- and intra-observer agreement between radiologists using a well-defined method to measure the MUL on the prostate MRI.

METHODS

Prostate cancer patients underwent a preoperative MRI and robot-assisted radical prostatectomy (RARP) at one high-volume RARP center. MUL measurement was based on well-defined landmarks on sagittal T2-weighted (anatomical) images. Three radiologists independently performed MUL measurements retrospectively in 106 patients blinded to themselves, to each other, and to clinical outcomes. The inter- and intra-observer agreement of MUL measurement between the radiologists were calculated, expressed as intra-class correlation coefficient (ICC).

RESULTS

The initial inter-observer agreement was ICC 0.63; 95% confidence interval (CI) 0.28-0.81. Radiologist 3 measured the MUL mean 3.9 mm (SD 3.3) longer than the other readers, interpreting the caudal point of the MUL (penile base) differently. After discussion on the correct anatomical definition, radiologist 3 re-assessed all scans, which resulted in a high inter-observer agreement (ICC 0.84; 95% CI 0.66-0.91). After a subsequent reading by radiologists 1 and 2, the intra-observer agreements were ICC 0.93; 95% CI 0.89-0.96, and ICC 0.98; 95% CI 0.97-0.98, respectively. Limitation is the monocenter design.

CONCLUSIONS

The MUL can be measured reliably with high agreement among radiologists.

KEY POINTS

• After discussion on the correct anatomical definition, the inter- and intra - observer agreements of membranous urethral length (MUL) measurement on magnetic resonance imaging (MRI) were high. • A reproducible method to measure the MUL can improve the clinical usefulness of prediction models for urinary continence after RARP which may benefit patient counselling.

Value of Different Magnetic Resonance Imaging-based Measurements of Anatomical Structures on Preoperative Prostate Imaging in Predicting Urinary Continence After Radical Prostatectomy in Men with Prostate Cancer: A Systematic Review and Meta-analysis

CONTEXT

Measurements of anatomical structures on preoperative prostate magnetic resonance imaging (MRI) are used in risk models for treatment decisions to predict urinary continence (UC) following radical prostatectomy (RP). However, the association between these parameters and UC is unclear.

OBJECTIVE

To systematically summarize the literature on prognostic preoperative prostate MRI measurements of (peri)prostatic structures in relation to time to recovery of postoperative UC in men with prostate cancer.

EVIDENCE ACQUISITION

Online libraries were searched up to August 27, 2021. Article selection and critical appraisal were performed by two reviewers. All papers reporting on preoperative MRI measurements with UC correlation in univariable or multivariable analyses were included.

EVIDENCE SYNTHESIS

In the 50 studies included (mostly retrospective), 57 MRI parameters were evaluated. The pooled analyses showed that greater membranous urethra length (MUL) was prognostic for regaining UC at 1 mo (odds ratio [OR] 1.15, 95% confidence interval [CI] 1.10-1.21), 3 mo (OR 1.23, 95% CI 1.16-1.31), 6 mo (OR 1.16, 95% CI 1.08-1.25), and 12 mo (OR 1.19, 95% CI 1.10-1.29). Several other anatomical structures showed at least in one study a significant correlation with later return to UC: four prostate-related parameters (greater depth, apical protrusion, larger intravesical protrusion, small dorsal vascular complex), five urethra-related parameters (thicker wall, severe fibrosis, smaller volume, larger preoperative angle between the prostate axis and membranous urethra, shorter minimal residual MUL), and six musculoskeletal-related parameters (lower perfusion ratio, thinner levator ani muscle, larger inner or outer levator distance, shorter pelvic diaphragm length, and larger midpelvic area).

CONCLUSIONS

Greater MUL as measured on preoperative MRI was an independent prognostic factor for return to UC within 1 mo after RP and remained prognostic at 12 mo. Other anatomical structures may potentially be predictive, but these would need to be substantiated in prospective trials before being adopted in postoperative UC risk models for treatment decisions in men with prostate cancer.

PATIENT SUMMARY

We summarized study data on the relation between measurements of anatomical structures on preoperative magnetic resonance imaging scans and urinary continence after removal of the prostate. Greater length of one part of the urethra (membranous urethra) is associated with faster return to continence. Other anatomical structures have potential for predicting postoperative continence, but need further investigation.

The role of preoperative prostatic shape in the recovery of urinary continence after robotic radical prostatectomy: a single cohort analysis

BACKGROUND

To explore the role of preoperative MRI prostate shape in urinary incontinence after robot-assisted radical prostatectomy (RARP).

METHODS

Patients were stratified into four groups based on the mpMRI prostatic apex shape: Group A (prostatic apex overlapping the membranous urethra anteriorly and posteriorly), Group B and C (overlap of the prostatic apex of the anterior or posterior membranous urethra, respectively) and Group D (no overlap). Preoperative variables and intraoperative data were compared. Continence recovery was defined as no pad/day or 1 safety pad/day by an outpatient evaluation performed at 1, 3, 6, and 12 months after RARP.

RESULTS

One hundred patients underwent RARP were classified as belonging to Group A (n = 30), Group B (n = 16), Group C (n = 14), and Group D (n = 40). Group D showed a significantly more favorable urinary continence recovery after RARP respect to all the other shapes presenting any forms of overlapping (HR = 1.9, 95% CI 1.2-3.1, p = 0.007). The estimated HR remained substantially unchanged after adjusting by age, body mass index, CCI, prostate volume, and bladder neck sparing (HR = 1.9, 95% CI 1.1-3.2, p = 0.016). The continence recovery median time was 9 months for Group A + B + C (95% CI 5-11) and 4 months for Group D (95% CI 2-6) (p = 0.023).

CONCLUSION

Shape D showed a better continence recovery when compared to other shapes presenting any kind of overlapping of the prostatic apex over the membranous urethra.

Urethral Sphincter Length but Not Prostatic Apex Shape in Preoperative MRI Is Associated with Mid-Term Continence Rates after Radical Prostatectomy

Background: To test the impact of urethral sphincter length (USL) and anatomic variants of prostatic apex (Lee-type classification) in preoperative multiparametric magnet resonance imaging (mpMRI) on mid-term continence in prostate cancer patients treated with radical prostatectomy (RP). Methods: We relied on an institutional tertiary-care database to identify patients who underwent RP between 03/2018 and 12/2019 with preoperative mpMRI and data available on mid-term (>6 months post-surgery) urinary continence, defined as usage 0/1 (-safety) pad/24 h. Univariable and multivariable logistic regression models were fitted to test for predictor status of USL and prostatic apex variants, defined in mpMRI measurements. Results: Of 68 eligible patients, rate of mid-term urinary continence was 81% (n = 55). Median coronal (15.1 vs. 12.5 mm) and sagittal (15.4 vs. 11.1 mm) USL were longer in patients reporting urinary continence in mid-term follow-up (both p < 0.01). No difference was recorded for prostatic apex variants distribution (Lee-type) between continent vs. incontinent patients (p = 0.4). In separate multivariable logistic regression models, coronal (odds ratio (OR): 1.35) and sagittal (OR: 1.67) USL, but not Lee-type, were independent predictors for mid-term continence. Conclusion: USL, but not apex anatomy, in preoperative mpMRI was associated with higher rates of urinary continence at mid-term follow-up.

Correlation of Urine Loss after Catheter Removal and Early Continence in Men Undergoing Radical Prostatectomy

BACKGROUND

To determine the correlation between urine loss in PAD-test after catheter removal, and early urinary continence (UC) in RP treated patients.

METHODS

Urine loss was measured by using a standardized, validated PAD-test within 24 h after removal of the transurethral catheter, and was grouped as a loss of <1, 1-10, 11-50, and >50 g of urine, respectively. Early UC (median: 3 months) was defined as the usage of no or one safety-pad. Uni- and multivariable logistic regression models tested the correlation between PAD-test results and early UC. Covariates consisted of age, BMI, nerve-sparing approach, prostate volume, and extraprostatic extension of tumor.

RESULTS

From 01/2018 to 03/2021, 100 patients undergoing RP with data available for a PAD-test and early UC were retrospectively identified. Ultimately, 24%, 47%, 15%, and 14% of patients had a loss of urine <1 g, 1-10 g, 11-50 g, and >50 g in PAD-test, respectively. Additionally, 59% of patients reported to be continent. In multivariable logistic regression models, urine loss in PAD-test predicted early UC (OR: 0.21 vs. 0.09 vs. 0.03; for urine loss 1-10 g vs. 11-50 g vs. >50 g, Ref: <1 g; all p < 0.05).

CONCLUSIONS

Urine loss after catheter removal strongly correlated with early continence as well as a severity in urinary incontinence.