Exploring positive surgical margins after minimally invasive radical prostatectomy: Does body habitus really make a difference ?

BMI Impact on Readmissions for Patients Undergoing Robot-Assisted Radical Prostatectomy: A Monocentric, Single-Surgeon Serial Analysis of 500 Cases

Due to more difficult intraoperative courses, elevated rates of case abortion and unfavored postoperative outcomes in obese patients, urologists tend to consider other therapeutic modalities than prostate removal in very obese patients. With the surge in robotic surgery in the last two decades, more obese patients have undergone robot-assisted radical prostatectomy (RARP).

OBJECTIVE

This current, monocentric, retrospective serial study investigates primarily the impact of obesity on readmissions and secondarily the major complications of RARP.

METHODS

Five hundred patients from one referral center who underwent RARP between April 2019 and August 2022 were included in this retrospective study. To investigate the impact of patient BMI on postoperative outcomes, we divided our cohort into two groups with a cut-off of 30 kg/m² (according to the WHO definition). Demographic and perioperative data were analyzed. Postoperative complications and readmission rates were compared between standard, normal patients (NOBMI-BMI under 30; n = 336, 67.2%) and overweight patients (OBMI-BMI equal to/more than 30; n = 164, 32.8%).

RESULTS

OBMI patients had bigger prostates on TRUS, more comorbidities and worse baseline erectile function scores. They also received fewer nerve-sparing procedures than their counterparts (p = 0.005). Analysis showed no statistically significant differences in readmission rates or in minor or major complications (p = 0.336, 0.464 and 0.316, respectively). In a univariate analysis, BMI could predict positive surgical margins (p = 0.021).

CONCLUSION

Performing RARP in obese patients seems to be safe and feasible, without major adverse events or elevated readmission rates. Obese patients should be informed preoperatively about the elevated risk of higher PSMs and technically more difficult nerve-sparing procedures.

Clinicopathological Significances of Positive Surgical Resection Margin after Radical Prostatectomy for Prostatic Cancers: A Meta-Analysis

Background and Objectives: This study aims to elucidate the positive rate and the clinicopathological significance of surgical margin after radical prostatectomy (RP) through a meta-analysis. Materials and Methods: This meta-analysis finally used 59 studies, including the information about the positive surgical margin (PSM) and those clinicopathological significances after RP. The subgroup analysis for the estimated rates of PSM was evaluated based on types of surgery, grade groups, and pathological tumor (pT) stages. We compared the clinicopathological correlations between positive and negative surgical margins (NSM). Results: The estimated PSM rate was 25.3% after RP (95% confidence interval [CI] 21.9-29.0%). The PSM rates were 26.0% (95% CI 21.5-31.1%) 28.0% (95% CI 20.2-37.5%) in robot-assisted RP and nerve-sparing RP, respectively. The PSM rate was significantly higher in high-grade groups than in low-grade groups. In addition, the higher pT stage subgroup had a high PSM rate compared to the lower pT stage subgroups. Patients with PSM showed significantly high PSA levels, frequent lymphovascular invasion, lymph node metastasis, and extraprostatic extension. Biochemical recurrences (BCRs) were 28.5% (95% CI 21.4-36.9%) and 11.8% (95% CI 8.1-16.9%) in PSM and NSM subgroups, respectively. Patients with PSM showed worse BCR-free survival than those with NSM (hazard ratio 2.368, 95% CI 2.043-2.744%). Conclusions: Our results showed that PSM was significantly correlated with worse clinicopathological characteristics and biochemical recurrence-free survival. Among the results in preoperative evaluations, grade group and tumor stage are useful for the prediction of PSM.

Obesity leads to a higher rate of positive surgical margins in the context of robot-assisted radical prostatectomy. Results of a prospective multicenter study

Introduction

Current results concerning the effect of body mass index (BMI) on positive surgical margins (PSMs) after robot-assisted radical prostatectomy (RARP) in patients with localized prostate cancer are inconsistent. Therefore, the aim of this study was to further analyse the association between BMI and PSMs after RARP.

Material and methods

Between March 2017 and December 2017 a multicentre, prospective, randomised, single-blind series with a blinded outcome assessment of 232 RARP patients was performed. Multivariate logistical regression models were used to analyse the independent effect of obesity, with body-mass-index (BMI) dichotomised at 30 kg/m² (model-1) and at 90^th percentile (model-2), on PSMs.

Results

Median BMI was 27.2 kg/m², PSMs were found in 15.5% (n = 36). In multivariate model-1, obesity did not have a significant effect on PSMs (OR 2.34, p = 0.061). However, if BMI was dichotomized at the 90^th percentile (BMI ≥33.7 kg/m²), patients with a higher BMI showed PSMs four-times more frequently (OR 3.99, p = 0.013). In both models, preoperative prostate-specific antigen (PSA) levels and pathological tumour stage had a significant effect on PSMs. There was no significant correlation between BMI and the extent of PSMs, nor a significant difference between the BMI groups and the localisation of PSMs. There was a higher percentage of posteriolateral PSM localisation in obese patients compared to patients with a BMI of less than 30 kg/m² (58.3% and 25.3% of the localisations were posterolateral in obese and non-obese patients, respectively), however this effect was not statistically significant (p = 0.175).

Conclusions

In addition to a longer operation time and about twice as many complications, patients with a BMI of ≥33.7 kg/m² had a higher PSM rate after RARP. Differences in localization of PSMs in relation to obesity should be evaluated in future research.

Preoperative Predictive Model of Narrow Pelvis in Laparoscopic Radical Prostatectomy Through Computed Tomography

Objective: At present, prostate cancer radical surgery still lacks an objective standard for predicting the anatomic difficulty of surgery through preoperative examination. Due to the poor prognosis and surgical complications caused by "Narrow Pelvis," a pelvic model for prediction is urgently needed. The purpose of this study is to present objective preoperative assessing indicators to predict the surgical difficulty caused by pelvic anatomic abnormalities during laparoscopic radical prostatectomy (LRP). Methods: Patients undergoing LRP were retrospectively analyzed and separated into "Common Pelvis" or "Difficult Pelvis" groups according to the preset criteria. The clinical data and pelvic imaging data of the two groups were compared to obtain statistically significant differences. The results were compared and validated in 500 ordinary males. Logistic regression analysis was performed to optimize these indicators into a scoring model, "Laparoscopic Radical Prostatectomy Narrow Pelvic Predictive Index (LRP-NPPI)" for predicting "Difficult Pelvis." Results: Of the 145 patients undergoing LRP, 22 (15.2%) were included in the "Difficult Pelvis" group. Patients in the "Difficult Pelvis" group were more likely to have a narrower, shorter, deeper, more flattened pelvis, greater body mass index, more history of previous pelvic surgery, and greater prostate volume. Moreover, the larger amount of intraoperative blood loss and longer operation time were related. Compared with the "Common Pelvis" group, patients in the "Difficult Pelvis" have higher score of LRP-NPPI (p < 0.05). Conclusion: With the model we proposed, it is possible to predict patients with pelvic anatomical difficulties during LRP.