Impact of variations in bony pelvic dimensions on performing radical retropubic prostatectomy

Creation of a Novel, Race-Adjusted, and Risk-Adapted Scoring System to Predict Positive Surgical Margins and Prolonged Operative Time During Robotic Radical Prostatectomy

Objectives: To compare racial differences and pelvis dimensions between Caucasians and African Americans (AAs) and to develop a risk calculator and scoring system to predict the risk of prolonged operative time and presence of positive surgical margins (PSM) based on these dimensions. Materials and Methods: A retrospective review of 88 consecutive patients undergoing robot-assisted laparoscopic prostatectomy with a preoperative prostate MRI conducted. Data extraction included demographic, perioperative, and postoperative oncologic outcomes. Prostate-specific antigen (PSA) was obtained within 3 months postsurgery. Wilcoxon rank sum and Fisher's exact tests were used to compare continuous and categorical data, respectively. Single and multivariable regression analysis were used to determine contribution of each factor to the composite outcomes. A risk score was created based on this analysis for predicting the composite outcome. Results: We identified 88 consecutive patients with localized prostate cancer that underwent a preoperative prostate MRI. No statistically significant differences were found with respect to age, body mass index, or any postoperative outcome. PSA was lower at diagnosis (6.49 vs 9.72, p = 0.006) and operative times were shorter in Caucasians. Rates of PSM (13 vs 14, p = 0.35), biochemical recurrence (4 vs 2, p = 0.69), and complications did not vary between the groups. Caucasians had wider/shallower pelvis dimensions. Based on these variables, we found that the log (odds of OR time >3 hours or PSM) = -5.333 + 1.158 (if AA) +0.105 × PSA +0.076 × F -0.035 × G with an area under the receiver operating characteristic curve = 0.73. Using the predefined variables, patients can be risk stratified for PSM or prolonged operative times. Conclusions: Several pelvis dimensions were found to be shorter/narrower in AAs and were associated with longer operative times. The presented risk calculator and stratification system may be used to predict prolonged operative time or having PSM.

Value of the newly developed pelvic dimension index/prostate volume ratio in predicting positive surgical margin in prostate cancer

PURPOSE

To evaluate the diagnostic performance of pelvimetric measurements, in particular the pelvic dimension index (PDI)/prostate volume (PV) ratio (PDI/PV), in predicting positive surgical margin (PSM) in prostate cancer (PC).

MATERIALS AND METHODS

127 patients who had pre-operative pelvic imaging were included in this study. Demographic and clinical data were recorded. Apical depth (AD), interspinous distance (ISD), intertuberous distance (ITD), bony femoral width (BFW), soft-tissue width (SW), symphysis angle (SA), anteroposterior diameter of the pelvic inlet (API), anteroposterior diameter of the pelvic mid-plane (APM), anteroposterior diameter of the pelvic outlet (APO), pelvic depth (PD), bony width index (BWI), soft tissue width index (SWI), pelvic cavity index (PCI), PDI and PV were measured on MRI or CT. Using PDI and PV, we developed a new parameter of "PDI to PV ratio" (PDI/PV). Logistic regression analysis was used to determine the predictive potential of variables in detection of PSM.

RESULTS

The AD, PV, SA and total prostate specific antigen (PSA) were significantly higher in PSM( +), while PDI, BWI, SWI, API, PDI/PV and PD were significantly lower in PSM( +) (p < 0.05). In multivariate analysis, PDI/PV ratio and clinical stage were all significant predictor of PSM, where PDI/PV ratio was the strongest predictor, followed by clinical stage.

CONCLUSION

Pelvimetric measurements indicating deep location of the prostatic apex rather than pelvic width are more effective in predicting PSM. Prediction of PSM with pelvimetric measurements, in particular PDI/PV ratio, may be helpful for surgical planning in preoperative period.

Value of three-dimensional visualization of preoperative prostatic magnetic resonance imaging based on measurements of anatomical structures in predicting positive surgical margin after radical prostatectomy

Background

Positive surgical margin (PSM) or apical positive surgical margin (APSM) is an established predictive factor of biochemical recurrence or disease progression in prostate cancer (PCa) patients after radical prostatectomy. Since there are limited usable magnetic resonance imaging (MRI)-based models, we sought to explore the role of three-dimensional (3D) visualization for preoperative MRI in the prediction of PSM or APSM.

Methods

From December 2016 to April 2022, 149 consecutive PCa patients who underwent radical prostatectomy were retrospectively selected from the Second Affiliated Hospital of Dalian Medical University. According to the presence of PSM or APSM, patients were divided into a PSM group (n=41) and a without PSM group (n=108) and into an APSM group (n=33) and a without APSM group (n=116). Twenty-one parameters, including prostate apical shape, PCa distance to the membranous urethra, and pubic angle, were measured on 3D visualization of MRI. The development of the nomogram models was built by the findings of multivariate logistic regression analysis for significant factors.

Results

To predict the probability of PSM, a longer PCa distance to the membranous urethra (OR=0.136, p=0.019) and the distance from the anterior peritoneum to the anterior border of the coccyx (work space AP, OR=0.240, p=0.030) were independent protective factors, while a type 3 prostate apical shape (OR=8.262, p=0.025) and larger pubic angle 2 (OR=5.303, p=0.029) were identified as independent risk factors. The nomogram model presented an area under the curve (AUC) of the receiver operating characteristic curve (ROC) of PSM of 0.777. In evaluating the incidence of APSM, we found that the distance to the membranous urethra (OR=0.135, p=0.014) was associated with a low risk of APSM, while larger pubic angle 1 (OR=4.666, p=0.043) was connected to a higher risk of APSM. The nomogram model showed that the AUC of APSM was 0.755.

Conclusion

As 3D visualization for preoperative MRI showed good performance in predicting PSM or APSM, the tool might be potentially valuable, which also needs to be validated by multicenter, large-scale, prospective studies.

Can pelvic diameter measurement have an effect on surgical outcomes in radical cystectomy?

OBJECTIVE

To determine the effectiveness of pelvis diameters in determining postoperative outcomes in men who underwent open radical cystectomy + urinary diversion, it is aimed to predict the factors that may affect the operative difficulty and possible surgical outcomes before the operation.

METHODS

A total of 79 radical cystectomy patients operated in our institution with preoperative computed tomography (CT) were included the study. Pelvic dimensions; symphysis angle (SA), upper conjugate, lower conjugate, pelvic depth, apical depth (AD), interspinous distance (ISD), bone femoral width and soft tissue width were measured by preoperative CT. ISD index were defined as ISD/AD. Postoperative outcomes and indicators of operative difficulty were recorded. Regression analyses were used to predict perioperative and postoperative outcomes.

RESULTS

Total of 96 complications were observed in 52 of the 79 patients in ninety days (65,8%) with a mean age of 68.25 years. There were significant correlations between SA and body mass index (BMI) with operative time (p = 0.006, p < 0.001; respectively). For estimated blood loss, there were significant correlations between preoperative hematocrit (p = 0,031). Analysis of multivariate logistic regression revealed that higher Charlson comorbidity index (CCI) and BMI were found to be significant predictors for major complications while CCI, pathological T stage and ISD index are prominent predictors for surgical margin positivity.

CONCLUSIONS

Pelvic dimensions are not significant with minor or major complications. However, operative time may be associated with SA. Also, narrow and deep pelvis may increase the risk of positive surgical margins.

Do bony pelvis parameters affect perioperative outcomes in open radical prostatectomy?

Objective

The present study aimed to evaluate the predictive value of bony pelvic parameters measured by computerized tomography (CT) for use in the estimation of the likely technical difficulties that may be encountered when performing open radical prostatectomy (RP) for localized prostate cancer.

Material and methods

One hundred patients, undergoing open RP for localized prostate cancer, were evaluated between October 2016 to November 2018. All operations were performed by the same experienced surgeon. Pelvic parameters were measured using spiral CT images. Data were retrospectively collected from medical, operative, radiology, and pathology records and analyzed. Positive surgical margin (PSM), presence of vesicourethral anastomosis stricture (VUAS) and urine leakage, operative time, urethral catheterization time, and estimated blood loss were used as indicators of operative difficulty. Univariate and multivariate analyses were performed to determine the significance of these variables.

Results

There was no significant correlation between the pelvic parameters of the patients and the presence of PSM, VUAS, and urine leakage. Only PSA levels and pathological tumor stage were higher in patients with PSM (p = 0.002 and p = 0.001). On univariate and multivariate analyses, none of the individual pelvic parameters assessed showed a significant relationship with the operation time, estimated blood loss, and urethral catheterization time. In univariate analysis, there was a significant relationship between PSA levels and pathological tumor stage and operation time (p = 0.048 and p = 0.001, respectively).

Conclusion

Bony pelvic parameters may not be a significant factor in influencing the perioperative outcomes of open RP. Higher PSA levels and pathological tumor stage may lead to surgical margin positivity and longer operative time.

The pelvic anatomic index is an independent predictor for the difficulty of radical prostatectomy

OBJECTIVES

The aim of the study was to investigate whether a novel simple measurement of pelvic anatomy, the pelvic anatomical index (PAI), which is obtained from simple physical examination, was predictive for potential difficulty and adverse outcome in radical prostatectomy.

MATERIALS AND METHODS

Available data from 73 consecutive radical prostatectomy patients were analyzed. The distances between umbilicus and cranial edge of the symphysis pubis (USPD) and between root of the penis and umbilicus (PUD) were measured. PAI was obtained using the formula (PUD/USPD) × body mass index (BMI). Indicators of surgical difficulty assessed were operation time (OT), dorsal vein bleeding (DVB), total blood loss (TBL), and surgical margin (SM) status. Patients with below-median values of the OT, DVB, TBL, and had negative SM were grouped as favorable surgery (n = 18).

RESULTS

Median OT, DVB, and TBL were 215 (IQR: 187.5-240) min, 380 (IQR: 200-500) cc, and 1000 (IQR: 700-1300) cc, respectively. Both PAI and BMI were significantly correlated with TBL, DVB, and OT (p < 0.05, for all). PAI and BMI significantly associated with favorable surgery (p = 0,006 and p = 0.048, respectively). However, only PAI was an independent predictor of favorable surgery in multivariable logistic regression analysis. A PAI 36 kg/m² was determined as the threshold value for favorable surgery with 83.3% sensitivity and 60% specificity.

CONCLUSION

PAI significantly correlated with almost all surgical parameters and was a significant independent predictor of favorable surgery. PAI can enable the physician to select and discuss individualized treatment options for patients during preoperative planning.

Pelvic dimensions do not impact on complications and operative difficulty in radical cystoprostatectomy and orthotopic neobladder

BACKROUND

To evaluate the factors including pelvic dimensions, which might influence operative difficulty and complications after open radical cystoprostatectomy and orthotopic neobladder reconstruction in men.

METHODS

A total of 198 RC patients operated in our institution with preoperative magnetic resonance (MRI) were analyzed were included in the study. Pelvic dimensions, including interspinous distance (ISD), bony femoral - (BFW) and soft tissue width (SW), apical prostate depth (AD), upper conjugate (UC), lower conjugate (LC) were measured by preoperative MRI. BFW, ISD, and SW indexes were defined as BFW/AD, ISD/AD, and SW/AD, respectively. Complicatons were classified according to the Clavien-Dindo classification system. As indicators of surgical difficulty; transfusion rate (TR), estimated blood loss (EBL), operative time (OT) and hospital stay (HS) were assessed. SPSS version 17.0 was used for statistical analyses.

RESULTS

A total of 239 complications developed in 143 of the 198 patients (72.2%). Correlation analysis revealed a significant indirect relationship between TR and SW/AD (P=0.023). For EBL, there were significant indirect correlations between the SW/AD, BFW/AD and ISD/AD indexes (P=0.026, P=0.05, P=0.009; respectively). Additionally, OT was directly correlated body mass index (BMI) (P=0.001); and indirectly correlated with UC, SW/AD, and BFW/AD (P=0.047, P=0.038, P=0.016, respectively). On multivariate logistic regression analyses higher American Society of Anesthesiologist (ASA) score was associated with major complications. Multivariate analyses revealed that pathological stage was a significant predictor of EBL.

CONCLUSIONS

Patients with smaller pelvises might undergo more difficult surgeries. However, it seems that small sized pelvis does not impact on operative difficulty and complication rate in radical cystoprostatectomy and orthotopic neobladder.

[Pelvimetrics measures as predictives factors of positives surgical margins after robot-assisted laparoscopic prostatectomy]

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.

The association between the outcomes of extraperitoneal laparoscopic radical prostatectomy and the anthropometric measurements of the prostate by magnetic resonance imaging

Introduction and objective

To determine the association between the anthropometric measurements by magnetic resonance imaging (MRI) and perioperative outcomes of extraperitoneal laparoscopic radical prostatectomy (ELRP).

Materials and Methods

From 2008 to June 2016, 86 patients underwent preoperative MRI prior to undergoing ELRP for localized prostate cancer. We analyzed the associations between anthropometric measurements of MRI and the perioperative outcomes of patients who underwent ELRP.

Results

The mean patient age was 69.61±8.30 years. The medians of operating time and blood loss were 2.30 hours and 725.30ml, respectively. The total post-surgical complication rate was 1.16%. The median hospital stay was 6.50 days. The pathological stages for T2 and T3 were 45.74% and 34.04%, respectively. The rate as positive surgical margins (PSMs) was 18.09% (pT2 and pT3; 6.38% and 9.57%). The angles between pubic bone and prostate gland (angle 1&2), were significantly associated with operative time and hospital stay, respectively (p<0.05). There was no correlation between the pelvimetry and positive surgical margin.

Conclusions

The findings of the present study suggest that anthropometric measurements of the MRI are related to operative difficulties in ELRP. This study confirmed that MRI planning is the key to preventing complications in ELRP.

CT-based measurement of the inner pelvic volume

Background Surgery in the lesser pelvis is associated with a high complication rate as surgeons are spatially limited by solid anatomic structures and soft tissue borders. So far, only two-dimensional (2D) parameters have been used for risk stratification. Purpose To precisely measure the inner pelvic volume a computed tomography (CT)-based three-dimensional (3D) approach was established and compared to approximations by 2D parameter combinations. Material and Methods Thin-layered multi-slice CT datasets were used retrospectively for slice by slice depiction of the inner pelvic surface. The inner pelvic volume was then automatically compounded. Combinations of two to four 2D dimensions determined in 3D volume rendered reconstructions were correlated with the inner pelvic volume. Pearson's correlation coefficient and Chi square test were used for statistical calculations. Significance level was set at P < 0.05. Results In total 142 patients (91 men, 51 women) aged 64.8 ± 10.6 years at surgery were included in the study. Mean calculated pelvic volume was 1031.13 ± 180.06 cm³ (men, 996.57 ± 172.43 cm³; women, 1093.34 ± 178.39 cm³). Best approximations were obtained by combination of the 2D measurements transverse inlet and pelvic height for men (r = 0.799, P < 0.05) as well as transverse inlet, obstetric conjugate, interspinous distance and pelvic depth for women (r = 0.855, P < 0.05). Conclusion We describe a precise and reproducible CT-based method for pelvic volumetry. A less time consuming but still reliable approximation can be achieved by combination of two to four 2D dimensions.

Assessment of the variability in the dimensions of the intact pelvic canal in South Africans: A pilot study

Cephalopelvic disproportion is common among Africans and is a major cause of maternal and perinatal mortality and morbidity. As the dimensions of the pelvis may vary between populations and according to stature and age, they need to be considered during childbirth and also in the planning and performance of pelvic and perineal procedures. The aim of this study was to assess the possible variations in the dimensions of the intact pelvic canal in South Africans and their implications. Eighty intact cadaver pelves, belonging to 40 white South Africans (20 males and 20 females) and 40 black South Africans (20 males and 20 females) were used for both metric and geometric morphometric analyses. Pelvic inlet shapes did not differ significantly between groups but pelvic inlet and midpelvic dimensions were the greatest in white South Africans and females. The pubic symphyseal length was the greatest in white males and the smallest in black females, resulting in a smaller pelvic cavity anteriorly than for white females. Pelvic outlet shapes varied significantly between sexes in white South Africans and between white and black males. Females presented with the greatest dimensions. Black South African females presented with an elongated anteroposterior outlet diameter. Certain transverse pelvic diameters correlated positively with age in white males and with height in females. In planning childbirth options, the smaller pelvic inlet of black females and stature-dependent diameters should be considered. Pelvic and perineal surgery may be technically more challenging because of smaller pelvic dimensions in black South Africans, especially in males.

[RETROSPECTIVE ANALYSIS OF POSITIVE SURGICAL MARGIN AT RADICAL PROSTATECTOMY]

We retrospectively reviewed 182 patients who underwent radical prostatectomy in our hospital between April, 2009 to December, 2012, and who had not received any prior hormonal therapy. We also excluded the patients who couldn't followed up more than 6 months after surgery and pN1 patients. Positive surgical margins were observed in 65 cases. We determined what were the significant factors associated with the margin status. The another aim of present study is to evaluate the risk factor which might have significance for biochemical recurrence. BMI ≥ 25.0, prostate volume < 40 cm3, and biopsy positive core ≥ 25% were significant predictors of positive surgical margin. PSA nadir ≥ 0.02 ng/ml and pT3 were the significant factors which associated with biochemical recurrence of those patients with positive margin status.

Handling difficult anastomosis. Tips and tricks in obese patients and narrow pelvis

Vesico-urethral anastomosis (VUA) is a technically challenging step in robotic-assisted laparoscopic prostatectomy (RALP) in obese individuals. We describe technical modifications to facilitate VUA encountered in obese individuals and in patients with a narrow pelvis. A Pubmed literature search was performed between 2000 and 2012 to review all articles related to RALP, obesity and VUA for evaluation of technique, complications and outcomes of VUA in obese individuals. In addition to the technical modifications described in the literature, we describe our own experience to encounter the technical challenges induced by obesity and narrow pelvis. In obese patients, technical modifications like use of air seal trocar technology, steep Trendlenburg positioning, bariatric trocars, alterations in trocar placement, barbed suture and use of modified posterior reconstruction facilitate VUA in robotic-assisted radical prostatectomy. The dexterity of the robot and the technical modifications help to perform the VUA in challenging patients with lesser difficulty. The experience of the surgeon is a critical factor in outcomes in these technically challenging patients, and obese individuals are best avoided during the initial phase of the learning curve.

Impact of pelvic biometric measurements, visceral and subcutaneous adipose tissue areas on trifecta outcome and surgical margin status after open radical retropubic prostatectomy

OBJECTIVE

There is no sufficient evidence to demonstrate whether more challenging pelvic anatomy affects the functional and oncological outcomes of radical retropubic prostatectomy (RP). The aim of this study was to investigate the impact of pelvic biometric measurements, visceral and subcutaneous adipose tissue areas on trifecta outcome (cancer control, continence and potency) and surgical margin status after open RP.

MATERIALS AND METHODS

A retrospective study was performed on 270 patients who were diagnosed with clinically localized prostate cancer between 2005 and 2011 and underwent computed tomography imaging before RP. Pelvic bony and soft-tissue measurements, and visceral and subcutaneous adipose tissue area calculations were performed. Patients were evaluated for trifecta outcome and surgical margin status on univariate and multivariate analyses. Subgroup analysis was performed for prostate volume, body mass index (BMI) and D'Amico risk classification.

RESULTS

Univariate analysis revealed that patients with trifecta were younger, and had lower prostate-specific antigen (PSA) levels, wider symphysis angle, and narrower prostate width and soft-tissue width (p < 0.05). Patients with positive surgical margins were older, and had higher PSA levels, lower prostate volume and narrower prostate width (p < 0.05). Visceral adipose tissue area was lower in patients with trifecta when BMI was below 25 kg/cm² (p < 0.05). In multivariate analysis, PSA level and symphysis angle were statistically significant for trifecta while PSA level was the only statistically significant variable for positive surgical margins (p < 0.05). Interfemoral index was significant in the low-risk group of D'Amico classification for trifecta outcome.

CONCLUSION

Pelvic biometric measurements and adipose tissue area calculations may help in preoperative planning and the management of RP.

Are HIV-infected men vulnerable to prostate cancer treatment disparities?

BACKGROUND

HIV-infected (HIV(+)) men face cancer treatment disparities that impact outcome. Prostate cancer treatment and treatment appropriateness in HIV(+) men are unknown.

METHODS

We used electronic chart review to conduct a retrospective cohort study of 43 HIV(+) cases with prostate cancer and 86 age- and race-matched HIV-uninfected (HIV(-)) controls with prostate cancer, ages 40 to 79 years, from 2001 to 2012. We defined treatment appropriateness using National Comprehensive Cancer Network guidelines and the Charlson comorbidity index (CCI) to estimate life expectancy.

RESULTS

Median age was 59.5 years at prostate cancer diagnosis. Median CD4(+) T-cell count was 459.5 cells/mm(3), 95.3% received antiretroviral therapy, and 87.1% were virally suppressed. Radical prostatectomy was the primary treatment for 39.5% of HIV(+) and 71.0% of HIV(-) men (P = 0.004). Only 16.3% of HIV(+) versus 57.0% of HIV(-) men received open radical prostatectomy (P < 0.001). HIV(+) men received more radiotherapy (25.6% vs. 16.3%, P = 0.13). HIV was negatively associated with open radical prostatectomy (OR = 0.03, P = 0.007), adjusting for insurance and CCI. No men were undertreated. Fewer HIV(+) men received appropriate treatment (89.2% vs. 100%, P = 0.003), due to four overtreated HIV(+) men. Excluding AIDS from the CCI still resulted in fewer HIV(+) men receiving appropriate treatment (94.6% vs. 100%, P = 0.03).

CONCLUSION

Prostate cancer in HIV(+) men is largely appropriately treated. Under- or overtreatment may occur from difficulties in life expectancy estimation. HIV(+) men may receive more radiotherapy and fewer radical prostatectomies, specifically open radical prostatectomies.

IMPACT

Research on HIV/AIDS survival indices and etiologies and outcomes of this prostate cancer treatment disparity in HIV(+) men are needed.

New retractor facilitates exposure of the vascular pedicles in Chinese men with complex pelvis during radical cystectomy

OBJECTIVE

To evaluate the surgical instrument, the double-slice retractor of pelvis (DBR), for the division of the vascular pedicles from the bladder and prostate in male patients with complex pelvis during radical cystectomy.

METHODS

Radical cystectomy was performed on 140 male patients (all cases body mass index >28 kg/m(2), 29 cases having undergone partial cystectomy) with bladder cancer. With the aid of the double-slice retractor to expose vascular pedicles from the bladder and prostate, 80 radical cystectomies were performed. The others were treated as the control.

RESULTS

The double-slice retractor provided excellent exposure for the division of vascular pedicles from the bladder and prostate. The handling of the vascular pedicles from the bladder and prostate became easier and safer without unnecessary bleeding and injury in the rectum. In double-slice retractor and control groups, the operative time to handle the vascular pedicles during radical cystectomy in the double-slice retractor group was 12.2 ± 1.4 min compared with 22.6 ± 3.4 min for the control group (P < 0.05), and the blood loss was 30.3 ± 2.2 ml compared with 50.2 ± 4.5 ml (P < 0.05). For the whole radical cystectomy procedure, the operative time lasted 72.1 ± 9.2 min in the double-slice retractor group compared with 85.7 ± 6.8 min for the control group (P < 0.05), the whole blood loss was reduced to 340.3 ± 12.7 ml from 410.1 ± 11.4 ml in the control group (P < 0.05). And the rate of transfusion was geared down to 10% in the double-slice retractor group from 25% in the control (P < 0.05).

CONCLUSIONS

The use of the double-slice retractor for the exposure of vascular pedicles from the bladder and prostate is simple and effective in male patients with complex pelvis during radical cystectomy. We have devised a promising surgical instrument for the exposure of vascular pedicles.

Functional outcomes in African-Americans after robot-assisted radical prostatectomy

BACKGROUND AND PURPOSE

Previous studies have demonstrated differences in surgical outcomes after radical prostatectomy based on ethnicity. We compared sexual and urinary outcomes in African-American (AA) patients 6 and 12 months after robot-assisted radical prostatectomy (RARP) with those of non-AA patients.

PATIENTS AND METHODS

We reviewed our RARP database at our institution for patients with at least 12 months of follow-up. Erectile function was defined using the University of California, Los Angeles Prostate Cancer Index as erections "firm enough for masturbation and foreplay" or "firm enough for intercourse," while urinary continence was defined as being "pad free." Only patients who were potent and pad free preoperatively were included in the analysis. Multivariate logistic regression was used to compare postoperative potency and urinary pad-free status between AA and non-AA patients while controlling for pertinent demographic, clinical, and pathologic variables.

RESULTS

In the urinary continence analysis, 140 AA patients and 576 non-AA patients were included, compared with 105 AAs and 500 non-AA patients who were included in the analysis of sexual function. At 12 months postoperatively, a smaller proportion of AA patients were potent compared with non-AA patients (60% vs 76.4%, P=0.001). Similarly, we found a lower incidence of pad-free status for AA patients at 12 months postoperatively (55.7% vs 69.8%, P=0.039). Similar functional results were found at 6 months postoperatively for both analysis groups.

CONCLUSION

AA men appear to have worse urinary and sexual outcomes at 12 months after RARP compared with non-AA patients. At 6 months, there is no statistically significant difference. Further, longer-term studies are needed to validate these results.

Recovery of urinary function after radical prostatectomy: predictors of urinary function on preoperative prostate magnetic resonance imaging

PURPOSE

We determined whether pelvic soft tissue and bony dimensions on endorectal magnetic resonance imaging influence the recovery of continence after radical prostatectomy, and whether adding significant magnetic resonance imaging variables to a statistical model improves the prediction of continence recovery.

MATERIALS AND METHODS

Between 2001 and 2004, 967 men undergoing radical prostatectomy underwent preoperative magnetic resonance imaging. Soft tissue and bony dimensions were retrospectively measured by 2 raters blinded to clinical and pathological data. Patients who received neoadjuvant therapy, who were preoperatively incontinent or had missing followup for continence were excluded from study, leaving 600 patients eligible for analysis. No pad use defined continent. Logistic regression was used to identify variables associated with continence recovery at 6 and 12 months. We evaluated whether the predictive accuracy of a base model was improved by adding independently significant magnetic resonance imaging variables.

RESULTS

Urethral length and urethral volume were significantly associated with the recovery of continence at 6 and 12 months. Larger inner and outer levator distances were significantly associated with a decreased probability of regaining continence at 6 or 12 months, but they did not reach statistical significance for other points. Addition of these 4 magnetic resonance imaging variables to a base model including age, clinical stage, prostate specific antigen and comorbidities marginally improved the discrimination (12-month AUC improved from 0.587 to 0.634).

CONCLUSIONS

Membranous urethral length, urethral volume, and an anatomically close relation between the levator muscle and membranous urethra on preoperative magnetic resonance imaging are independent predictors of continence recovery after radical prostatectomy. The addition of magnetic resonance imaging variables to a base model improved the predictive accuracy for continence recovery, but the predictive accuracy remains low.

Modelling prostate motion for data fusion during image-guided interventions

There is growing clinical demand for image registration techniques that allow multimodal data fusion for accurate targeting of needle biopsy and ablative prostate cancer treatments. However, during procedures where transrectal ultrasound (TRUS) guidance is used, substantial gland deformation can occur due to TRUS probe pressure. In this paper, the ability of a statistical shape/motion model, trained using finite element simulations, to predict and compensate for this source of motion is investigated. Three-dimensional ultrasound images acquired on five patient prostates, before and after TRUS-probe-induced deformation, were registered using a nonrigid, surface-based method, and the accuracy of different deformation models compared. Registration using a statistical motion model was found to outperform alternative elastic deformation methods in terms of accuracy and robustness, and required substantially fewer target surface points to achieve a successful registration. The mean final target registration error (based on anatomical landmarks) using this method was 1.8 mm. We conclude that a statistical model of prostate deformation provides an accurate, rapid and robust means of predicting prostate deformation from sparse surface data, and is therefore well-suited to a number of interventional applications where there is a need for deformation compensation.

Factors affecting the outcome of extraperitoneal laparoscopic radical prostatectomy: pelvic arch interference and depth of the pelvic cavity

Purpose

To determine the effect of pelvic arch interference and the depth of the pelvic cavity, as shown on preoperative magnetic resonance imaging (MRI), on the performance of extraperitoneal laparoscopic radical prostatectomy (ELRP).

Materials and Methods

In 115 patients, pelvic bone images were obtained at the time of prostate MRI before ELRP. In the reconstructed sagittal plane, we measured the true conjugate diameter, the obstetric conjugate diameter, the difference between the true and obstetric diameters, and the distance between the true conjugate and the prostate apex (pelvic depth). We analyzed which factors were associated with operative time (OT), estimated blood loss (EBL), and positive surgical margins (PSMs).

Results

The difference between the true and obstetric conjugate diameters was 12.7±3.7 mm, and the pelvic depth was 59.9±6.0 mm. The OT, EBL, and the rate of PSMs were 260.1±91.1 minutes, 633.3±524.7 ml, and 19% (22/115), respectively. According to multiple linear regression analysis, predictors of a higher EBL included pelvic depth (3.0% higher per 1 mm increase in diameter difference, p=0.01) and prostate volume (1.5% higher per 1 cc increase in prostate volume, p=0.002). Factors associated with a longer OT were pelvic depth (p=0.04), serum prostate-specific antigen (p=0.04), prostate volume (p=0.02), and Gleason score (p=0.001). For PSMs, only pT2 was an independent factor.

Conclusions

Our results suggest that the depth of the pelvic cavity and prostate volume may increase surgical difficulty in patients undergoing ELRP.

Ethnic variation in pelvimetric measures and its impact on positive surgical margins at radical prostatectomy

OBJECTIVES

We sought to evaluate the ethnic variation in pelvimetry and its impact as a predictor of positive surgical margins (PSM) at radical prostatectomy (RP).

METHODS

Preoperative MRI was performed in 482 Caucasian and 103 African American (AA) men undergoing RP without previous treatment from July 2003 to January 2005 and November 2001 to June 2007, respectively. We measured bony and soft tissue dimensions on magnetic resonance imaging (MRI) to evaluate the pelvic inlet, midplane, prostate size, and apical depth. Analysis of covariance was performed to determine the effect of ethnicity on the midpelvic area (MPA). We performed multivariate logistic regression analysis for prediction of overall and site-specific PSM.

RESULTS

AA men had a significantly steeper symphysis pubis angle (median, 43.1 vs. 41.3°, respectively, P = .001) and smaller MPA (median, 78.5 vs. 83.9 cm(2), respectively, P = .004). Ethnicity and BMI were found to have a significant effect on MPA. Apical depth of the prostate was identified as a significant independent predictor of apical PSM, with a more pronounced effect in AA men. Pelvimetric measures were not a significant predictor of other sites of PSM.

CONCLUSIONS

AA men have a significantly smaller MPA and steeper symphysis angle. The adverse impact of a deep pelvis, as measured by the apical prostatic depth on apical PSM was found to be greater in AA men. Evaluation of pelvic dimensions and prostate parameters in preoperative MRI may add to our understanding of their impact on surgical outcomes.

The depth of the prostatic apex is an independent predictor of positive apical margins at radical prostatectomy

OBJECTIVE

To determine the effect of a deep and narrow pelvis on apical positive surgical margins (PSM) at radical prostatectomy (RP), controlling for other clinical and pathological variables and surgical approach, i.e. open retropubic (RRP) vs laparoscopic (LRP), as apical dissection is expected to be more challenging at RP with a prostate situated deep in a narrow pelvis.

PATIENTS AND METHODS

From July 2003 to January 2005, 512 consecutive patients with preoperative prostate magnetic resonance imaging (MRI) underwent RRP or LRP with no previous radio- or hormonal therapy. An additional 74 patients with preoperative MRI undergoing RP from December 2001 to June 2007 who had an apical PSM were also included, with 586 patients comprising the study population. Bony and soft-tissue pelvic dimensions, including interspinous distance (ISD), bony (BFW) and soft tissue (SW) pelvic width, apical prostate depth (AD) and symphysis pubis angle, were measured on preoperative MRI. The pelvic dimension index (PDI), bony width index (BWI) and soft-tissue width index (SWI) were defined as ISD/AD, BFW/AD and SW/AD, respectively. Multivariate logistic regression was used to assess the effect of pelvic dimensions on apical PSM, controlling for surgical approach and clinical and pathological variables.

RESULTS

There was no significant difference in ISD, BFW, SW or symphysis angle between patients with and without apical PSM. The AD was significantly greater in men with an apical PSM and consequently PDI, BWI and SWI were significantly lower in men with an apical PSM. Each of PDI, AD, BWI and SWI was a significant independent predictor of apical PSM, independent of surgical approach, and other clinicopathological variables. The main limitations of the study were that it was retrospective, and the relatively few patients with apical PSM.

CONCLUSIONS

Apical prostate depth is an independent risk factor for apical PSM at RP. MRI pelvimetry might allow for preoperative planning of the approach to RP.