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Updated: Feb 5, 2026

Retzius-Sparing Robot-Assisted Radical Prostatectomy
Published on: May 19, 2022
[Pelvimetrics measures as predictives factors of positives surgical margins after robot-assisted laparoscopic
C Moureaux1, D Boucaud-Maitre2, L Brureau1
1Service d'urologie du CHU de Guadeloupe, route de Chauvel, 97159 Pointe à Pitre/Abymes, France.
Introduction:
Anthropometric data report that pelvic bone of African subjects are narrower and the pelvic cavity is deeper. The aim of the study was to evaluate the influence of pelvic dimensions (PD) on Positive surgical margins (PSM) rate in Afro-Caribbean population after robot-assisted laparoscopic prostatectomy (RALP).
Patients And Methods:
Preoperative pelvic MRI of all patients who have had RALP at the University Hospital Center of Guadeloupe between January 2013 and December 2015 was retrospectively analyzed. PD, including the Height of the upper edge of the prostate (HP), the Apical Depth (AD) and Ischial Spines Distance (ISD), and indexes (prostate volumetric index [ISD/VP], apical depth index [ISD/AD] and prostate depth index [ISD/(AD/HP)]) were compared according to the presence or absence of PSM with uni and multivariate analysis.
Results:
One hundred and seventy-eight patients were included in the study, of whom 60 (33.7%) presented PSM. In univariate analysis, significant differences between the presence or absence of PSM were observed on the AD (30.3±8.7mm versus 24.8±8.0mm, P<0.001), the HP (9.5±8.5mm versus 16.8±11.9mm, P<0.001) and the ISD (89.6±8.8mm versus 96.1±8.4mm) as well as the indexes of apical depth and prostatic depth. In multivariate logistic regression, the ISD (P<0.001) and HP (P=0.02) were associated with increased likelihood of PSM, but not AD or indexes.
Conclusion:
This study suggests that interspinous distance is the best predictor of PSM during RALP in Afro-Caribbean patients. This measure may be useful to define the therapeutic pattern of patients with prostate cancer. A prospective study with a larger population, comparing RALP in Afro-Caribbean and in caucasians patients, would be needed.
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