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

Abstract

Purpose To test the effect of anatomic variants of the prostatic apex overlapping the membranous urethra (Lee type classification), as well as median urethral sphincter length (USL) in preoperative multiparametric magnetic resonance imaging (mpMRI) on the very early continence in open (ORP) and robotic-assisted radical prostatectomy (RARP) patients. Methods In 128 consecutive patients (01/2018–12/2019), USL and the prostatic apex classified according to Lee types A–D in mpMRI prior to ORP or RARP were retrospectively analyzed. Uni- and multivariable logistic regression models were used to identify anatomic characteristics for very early continence rates, defined as urine loss of ≤ 1 g in the PAD-test. Results Of 128 patients with mpMRI prior to surgery, 76 (59.4%) underwent RARP vs. 52 (40.6%) ORP. In total, median USL was 15, 15 and 10 mm in the sagittal, coronal and axial dimensions. After stratification according to very early continence in the PAD-test (≤ 1 g vs. > 1 g), continent patients had significantly more frequently Lee type D (71.4 vs. 54.4%) and C (14.3 vs. 7.6%, p = 0.03). In multivariable logistic regression models, the sagittal median USL (odds ratio [OR] 1.03) and Lee type C (OR: 7.0) and D (OR: 4.9) were independent predictors for achieving very early continence in the PAD-test. Conclusion Patients’ individual anatomical characteristics in mpMRI prior to radical prostatectomy can be used to predict very early continence. Lee type C and D suggest being the most favorable anatomical characteristics. Moreover, longer sagittal median USL in mpMRI seems to improve very early continence rates.

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

“…Indeed, Lee et al [60] proposed a new classification of prostatic apex shape on MR images: type A defined as a prostatic apex overlapping the membranous urethra both anteriorly The last group proved to be linked to an higher rate of early return to urinary continence. Furthermore, a more recent experience too proved how type C and D were associated to very early continence restoration after catheter removal following RP [61]. Moreover, the prostate apex can be close to the skeletal fibers of the urogenital diaphragm, and therefore apical lesions should be precisely described because they might involve these structures.…”

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

“…From a clinical point of view, current findings may be attributable to a potential malfunction of the external sphincter; either pre-existing or by an injury of the urethral sphincter during RP [18,27]. Even though full functional-length of urethral sphincter preservation was routinely performed in all patients, interindividual anatomical and tumor characteristics may have influenced the extent of preservation, and led to potential injury of the sphincter [28]. As a consequence, PAD-test results did not only profoundly correlate with early continence rate, but could also be taken as a measurement tool to estimate the severity of early incontinence after RP.…”

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

“…Previous anatomical and functional studies have demonstrated that a substantial functional part of the urethral sphincter is located intraprostatically between the colliculus seminalis and apex [ 10 , 23 , 24 ]. Bearing in mind that the apex shape varies widely among patients, up to 40% of the functional part of the urethral sphincter is covered by parenchymal apex tissue [ 25 – 27 ]. As a consequence, meticulous preservation of the full functional-length of the urethra would include preserving a substantial part of the urethral sphincter complex as well [ 10 ].…”