Ashwin Narasimha Sridhar | University College London (original) (raw)

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Papers by Ashwin Narasimha Sridhar

Research paper thumbnail of Morbidity and mortality after robot‐assisted radical cystectomy with intracorporeal urinary diversion in octogenarians: results from the European Association of Urology Robotic Urology Section Scientific Working Group

Research paper thumbnail of Pathological Findings and Magnetic Resonance Imaging Concordance at Salvage Radical Prostatectomy for Local Recurrence following Partial Ablation Using High Intensity Focused Ultrasound

The Journal of Urology, Jun 1, 2019

Purpose: We describe the pathological characteristics of recurrence following high intensity focu... more Purpose: We describe the pathological characteristics of recurrence following high intensity focused ultrasound partial ablation in men treated with salvage robot-assisted radical prostatectomy. We assessed the sensitivity of magnetic resonance imaging before salvage robot-assisted radical prostatectomy in these men. Materials and Methods: A total of 35 men underwent salvage robot-assisted radical prostatectomy after high intensity focused ultrasound partial ablation from 2012 to 2018. We compared clinicopathological characteristics before ultrasound and before salvage prostatectomy after ultrasound to histopathology on salvage prostatectomy. We assessed infield recurrence, out of field disease, positive surgical margins and magnetic resonance imaging sensitivity before salvage robot-assisted radical prostatectomy. Results: Before high intensity focused ultrasound 55.9% of men had multifocal disease and 47.1% had Gleason 3 + 3 disease outside the treatment field. Median time to salvage prostatectomy was 16 months (IQR 11–26). Indications for salvage prostatectomy were infield recurrence in 55.8% of cases, out of field recurrence in 20.6%, and infield and out of field recurrence in 23.5%. On salvage prostatectomy histopathology revealed significant cancer, defined as ISUP (International Society of Urological Pathology) 2 or greater, infield in 97.1% of cases, out of field in 81.3%, and infield and out of field in 79.4%. Of the cases 82.4% were adversely reclassified at salvage prostatectomy compared to 67.6% before ultrasound. The positive surgical margin rate was 40.0%. Of the positive margins 84.6% were in the region of previous ultrasound despite wide excision, including pT2 in 28.6%, pT3 in 47.6% and size 3 mm or greater, pT3 or multifocal (ie significant) in 31.4%. After ultrasound the sensitivity of magnetic resonance imaging for infield and out of field recurrence was 81.8% and 60.7%, respectively. Conclusions: Salvage robot-assisted radical prostatectomy may confer a higher risk of positive surgical margins, upgrading and up-staging than primary robot-assisted radical prostatectomy. High intensity focused ultrasound carries a risk of recurrence inside and outside the ablation zone. This information may inform salvage surgical planning and patient counseling regarding the choice of initial therapy and salvage treatment after high intensity focused ultrasound.

Research paper thumbnail of Use of Magnetic Resonance Imaging and Biopsy Data to Guide Sampling Procedures for Prostate Cancer Biobanking

Journal of Visualized Experiments, Oct 10, 2019

Research paper thumbnail of MP19-04 Management of Intractable Bladder Neck Strictures Following Radical Prostatectomy

The Journal of Urology, Apr 1, 2020

Research paper thumbnail of Prostate Cancer Risk Calculator Apps in a Taiwanese Population Cohort: Validation Study (Preprint)

Research paper thumbnail of Can virtual classroom training improve the acquisition of robotic training skills? A prospective, cross-over, effectiveness study (V-ROBOT)

European urology open science, Nov 1, 2021

Research paper thumbnail of PD59-10 Factors Associated with High-Quality Surgery Following Radical Cystectomy: Analysis of the British Association of Urological Surgeons (Baus) Cystectomy Audit

The Journal of Urology, Sep 1, 2021

Research paper thumbnail of Survival outcome after robotic assisted radical cystectomy with intracorporal urinary diversion in elderly patients

European Urology Supplements, Sep 1, 2019

Research paper thumbnail of Development and external validation of a novel risk score to identify insignificant prostate cancer

Journal of Clinical Oncology, May 20, 2017

Research paper thumbnail of Oncological outcomes following intracorporeal robotic cystectomy versus open radical cystectomy: an analysis of 184 patients

Research paper thumbnail of Retzius-sparing technique independently predicts early recovery of urinary continence after robot-assisted radical prostatectomy

Journal of Robotic Surgery, Feb 22, 2022

Robot-assisted radical prostatectomy (RARP) is the conventional surgical treatment option for loc... more Robot-assisted radical prostatectomy (RARP) is the conventional surgical treatment option for localised prostate cancer. We investigated factors which may be associated with recovery of early urinary continence (EUC), including the use of the Retzius-sparing technique (RS-RARP). From March 2018 to December 2018, 501 consecutive patients underwent RARP at our high-volume institution. Four hundred and thirty-one patients had complete follow-up data and were included in our analyses. EUC was defined as zero pad use and social urinary continence (SUC) was defined as ≤ 1 pad/24-h period at 3 months following surgery. Patient demographics and clinical factors such as age, body mass index (BMI), neurovascular bundle (NVB) sparing, RS-RARP operative technique and operating surgeon (consultant, trainee) were recorded. Median age was 64.0 years (IQR 57.0–69.0 years) with a median BMI of 27.0 (IQR 25.0–29.9). RS-RARP accounted for 59 of the 431 (13.7%) patients. 196 (45.5%), 142 (32.9%) and 86 (20.0%) received a bilateral, unilateral and nil NVB sparing, respectively. EUC was achieved by 241 patients (55.9%) and SUC was achieved in 339 (78.7%) patients. Multivariable logistic regression analysis suggests younger age (HR 1.04, 95% CI 1.01–1.07, p = 0.014) and RS-RARP technique (HR 2.19, 95% CI 1.15–4.16, p = 0.017) were independently associated with EUC at 3 months even after adjusting for BMI, external membranous urethral length and NVB sparing. Our results suggest that RS-RARP technique is independently predictive of EUC even after accounting for confounding factors. These findings should be further validated in a prospective or randomised trial.

Research paper thumbnail of Peri-operative, functional and early oncologic outcomes of salvage robotic-assisted radical prostatectomy after high-intensity focused ultrasound partial ablation

Research paper thumbnail of Management of intractable bladder neck strictures following radical prostatectomy using the Memokath®045 stent

Journal of Robotic Surgery, Oct 15, 2019

Research paper thumbnail of PD36-12 MEASURING Objective Recovery of Activity Levels Using Wearable Devices Following Open vs Intracorporeal Robotic Cystectomy: Secondary Outcomes Analysis of the Iroc Randomized Trial

Research paper thumbnail of Do perioperative blood transfusions impact oncological outcomes of robot-assisted radical cystectomy with intracorporeal urinary diversion? Results from a large multi-institutional registry

Minerva Urology and Nephrology

Research paper thumbnail of Cost-analysis of robot-assisted radical cystectomy in Europe: A cross-country comparison

European Journal of Surgical Oncology

Research paper thumbnail of Effect of Robot-Assisted Radical Cystectomy With Intracorporeal Urinary Diversion vs Open Radical Cystectomy on 90-Day Morbidity and Mortality Among Patients With Bladder Cancer

Research paper thumbnail of Defining the Morbidity of Robot-Assisted Radical Cystectomy with Intracorporeal Urinary Diversion: Adoption of the Comprehensive Complication Index

Journal of Endourology, 2022

Research paper thumbnail of International consensus on classification of percutaneous nephrolithotomy (PCNL) to study and compare different types of PCNLs worldwide

Introduction & Objectives: Different types of PCNLs have evolved throughout the world and are sti... more Introduction & Objectives: Different types of PCNLs have evolved throughout the world and are still evolving. The aim of the international panel was to reach a consensus of 'speaking the same language' and using consensual terms for the different types of PCNLs when designing clinical trials, comparing outcomes, publishing, reviewing papers and presenting. Materials & Methods: The consensus was carried out as per the RAND/UCLA appropriateness methodology. An initial set of 32 statements were created reviewing the literature on consensus and guidelines on PCNLs. These incorporated procedure specific details, outcome measurements and a classification for PCNLs. Experts were then identified and invited to two rounds of input. The first included independent modifications to the proposed statements with the ability to add to the statements and the second round included scoring of all statements. In the third round, the panel met at the International Alliance of Urolithiasis Annual Conference in September 2019 to discuss each statement ranking and to decide which statements to include. Any disagreement or suggestion was noted, debated and discussed until resolution was obtained. Results: Every statement was discussed. The statements scoring above 80% were strongly agreed by the panel. The consensus process identified 25 recommendations that are useful to allow standardised reporting of procedure and outcomes, and to allow for comparison among various techniques. Table 1 shows the statements and recommendations sorted in order of their score with the first having the highest level of agreement.

Research paper thumbnail of New recommendations to reduce unnecessary blood tests after robot‐assisted radical prostatectomy

Research paper thumbnail of Morbidity and mortality after robot‐assisted radical cystectomy with intracorporeal urinary diversion in octogenarians: results from the European Association of Urology Robotic Urology Section Scientific Working Group

Research paper thumbnail of Pathological Findings and Magnetic Resonance Imaging Concordance at Salvage Radical Prostatectomy for Local Recurrence following Partial Ablation Using High Intensity Focused Ultrasound

The Journal of Urology, Jun 1, 2019

Purpose: We describe the pathological characteristics of recurrence following high intensity focu... more Purpose: We describe the pathological characteristics of recurrence following high intensity focused ultrasound partial ablation in men treated with salvage robot-assisted radical prostatectomy. We assessed the sensitivity of magnetic resonance imaging before salvage robot-assisted radical prostatectomy in these men. Materials and Methods: A total of 35 men underwent salvage robot-assisted radical prostatectomy after high intensity focused ultrasound partial ablation from 2012 to 2018. We compared clinicopathological characteristics before ultrasound and before salvage prostatectomy after ultrasound to histopathology on salvage prostatectomy. We assessed infield recurrence, out of field disease, positive surgical margins and magnetic resonance imaging sensitivity before salvage robot-assisted radical prostatectomy. Results: Before high intensity focused ultrasound 55.9% of men had multifocal disease and 47.1% had Gleason 3 + 3 disease outside the treatment field. Median time to salvage prostatectomy was 16 months (IQR 11–26). Indications for salvage prostatectomy were infield recurrence in 55.8% of cases, out of field recurrence in 20.6%, and infield and out of field recurrence in 23.5%. On salvage prostatectomy histopathology revealed significant cancer, defined as ISUP (International Society of Urological Pathology) 2 or greater, infield in 97.1% of cases, out of field in 81.3%, and infield and out of field in 79.4%. Of the cases 82.4% were adversely reclassified at salvage prostatectomy compared to 67.6% before ultrasound. The positive surgical margin rate was 40.0%. Of the positive margins 84.6% were in the region of previous ultrasound despite wide excision, including pT2 in 28.6%, pT3 in 47.6% and size 3 mm or greater, pT3 or multifocal (ie significant) in 31.4%. After ultrasound the sensitivity of magnetic resonance imaging for infield and out of field recurrence was 81.8% and 60.7%, respectively. Conclusions: Salvage robot-assisted radical prostatectomy may confer a higher risk of positive surgical margins, upgrading and up-staging than primary robot-assisted radical prostatectomy. High intensity focused ultrasound carries a risk of recurrence inside and outside the ablation zone. This information may inform salvage surgical planning and patient counseling regarding the choice of initial therapy and salvage treatment after high intensity focused ultrasound.

Research paper thumbnail of Use of Magnetic Resonance Imaging and Biopsy Data to Guide Sampling Procedures for Prostate Cancer Biobanking

Journal of Visualized Experiments, Oct 10, 2019

Research paper thumbnail of MP19-04 Management of Intractable Bladder Neck Strictures Following Radical Prostatectomy

The Journal of Urology, Apr 1, 2020

Research paper thumbnail of Prostate Cancer Risk Calculator Apps in a Taiwanese Population Cohort: Validation Study (Preprint)

Research paper thumbnail of Can virtual classroom training improve the acquisition of robotic training skills? A prospective, cross-over, effectiveness study (V-ROBOT)

European urology open science, Nov 1, 2021

Research paper thumbnail of PD59-10 Factors Associated with High-Quality Surgery Following Radical Cystectomy: Analysis of the British Association of Urological Surgeons (Baus) Cystectomy Audit

The Journal of Urology, Sep 1, 2021

Research paper thumbnail of Survival outcome after robotic assisted radical cystectomy with intracorporal urinary diversion in elderly patients

European Urology Supplements, Sep 1, 2019

Research paper thumbnail of Development and external validation of a novel risk score to identify insignificant prostate cancer

Journal of Clinical Oncology, May 20, 2017

Research paper thumbnail of Oncological outcomes following intracorporeal robotic cystectomy versus open radical cystectomy: an analysis of 184 patients

Research paper thumbnail of Retzius-sparing technique independently predicts early recovery of urinary continence after robot-assisted radical prostatectomy

Journal of Robotic Surgery, Feb 22, 2022

Robot-assisted radical prostatectomy (RARP) is the conventional surgical treatment option for loc... more Robot-assisted radical prostatectomy (RARP) is the conventional surgical treatment option for localised prostate cancer. We investigated factors which may be associated with recovery of early urinary continence (EUC), including the use of the Retzius-sparing technique (RS-RARP). From March 2018 to December 2018, 501 consecutive patients underwent RARP at our high-volume institution. Four hundred and thirty-one patients had complete follow-up data and were included in our analyses. EUC was defined as zero pad use and social urinary continence (SUC) was defined as ≤ 1 pad/24-h period at 3 months following surgery. Patient demographics and clinical factors such as age, body mass index (BMI), neurovascular bundle (NVB) sparing, RS-RARP operative technique and operating surgeon (consultant, trainee) were recorded. Median age was 64.0 years (IQR 57.0–69.0 years) with a median BMI of 27.0 (IQR 25.0–29.9). RS-RARP accounted for 59 of the 431 (13.7%) patients. 196 (45.5%), 142 (32.9%) and 86 (20.0%) received a bilateral, unilateral and nil NVB sparing, respectively. EUC was achieved by 241 patients (55.9%) and SUC was achieved in 339 (78.7%) patients. Multivariable logistic regression analysis suggests younger age (HR 1.04, 95% CI 1.01–1.07, p = 0.014) and RS-RARP technique (HR 2.19, 95% CI 1.15–4.16, p = 0.017) were independently associated with EUC at 3 months even after adjusting for BMI, external membranous urethral length and NVB sparing. Our results suggest that RS-RARP technique is independently predictive of EUC even after accounting for confounding factors. These findings should be further validated in a prospective or randomised trial.

Research paper thumbnail of Peri-operative, functional and early oncologic outcomes of salvage robotic-assisted radical prostatectomy after high-intensity focused ultrasound partial ablation

Research paper thumbnail of Management of intractable bladder neck strictures following radical prostatectomy using the Memokath®045 stent

Journal of Robotic Surgery, Oct 15, 2019

Research paper thumbnail of PD36-12 MEASURING Objective Recovery of Activity Levels Using Wearable Devices Following Open vs Intracorporeal Robotic Cystectomy: Secondary Outcomes Analysis of the Iroc Randomized Trial

Research paper thumbnail of Do perioperative blood transfusions impact oncological outcomes of robot-assisted radical cystectomy with intracorporeal urinary diversion? Results from a large multi-institutional registry

Minerva Urology and Nephrology

Research paper thumbnail of Cost-analysis of robot-assisted radical cystectomy in Europe: A cross-country comparison

European Journal of Surgical Oncology

Research paper thumbnail of Effect of Robot-Assisted Radical Cystectomy With Intracorporeal Urinary Diversion vs Open Radical Cystectomy on 90-Day Morbidity and Mortality Among Patients With Bladder Cancer

Research paper thumbnail of Defining the Morbidity of Robot-Assisted Radical Cystectomy with Intracorporeal Urinary Diversion: Adoption of the Comprehensive Complication Index

Journal of Endourology, 2022

Research paper thumbnail of International consensus on classification of percutaneous nephrolithotomy (PCNL) to study and compare different types of PCNLs worldwide

Introduction & Objectives: Different types of PCNLs have evolved throughout the world and are sti... more Introduction & Objectives: Different types of PCNLs have evolved throughout the world and are still evolving. The aim of the international panel was to reach a consensus of 'speaking the same language' and using consensual terms for the different types of PCNLs when designing clinical trials, comparing outcomes, publishing, reviewing papers and presenting. Materials & Methods: The consensus was carried out as per the RAND/UCLA appropriateness methodology. An initial set of 32 statements were created reviewing the literature on consensus and guidelines on PCNLs. These incorporated procedure specific details, outcome measurements and a classification for PCNLs. Experts were then identified and invited to two rounds of input. The first included independent modifications to the proposed statements with the ability to add to the statements and the second round included scoring of all statements. In the third round, the panel met at the International Alliance of Urolithiasis Annual Conference in September 2019 to discuss each statement ranking and to decide which statements to include. Any disagreement or suggestion was noted, debated and discussed until resolution was obtained. Results: Every statement was discussed. The statements scoring above 80% were strongly agreed by the panel. The consensus process identified 25 recommendations that are useful to allow standardised reporting of procedure and outcomes, and to allow for comparison among various techniques. Table 1 shows the statements and recommendations sorted in order of their score with the first having the highest level of agreement.

Research paper thumbnail of New recommendations to reduce unnecessary blood tests after robot‐assisted radical prostatectomy