Category: Laparoscopic/ Robotic: Other

MP25-17 - Factors influencing conversion of robotic partial nephrectomy: a retrospective analysis

Sun, Sep 23
10:00 AM - 12:00 PM

Introduction & Objective :

Appropriate review and interpretation of imaging prior to partial nephrectomy is critical for proper surgical planning and patient counseling. Nephrometry scores have been utilized to assess the risk of complications, but their utility to predict conversion to either open partial (OPN) or laparoscopic radical nephrectomy (LRN) has been poorly studied.  Our goal is to evaluate the parameters of RENAL and PADUA scores in predicting robotic-assisted partial nephrectomies (RAPN) that required conversion.


Methods :

Northwestern Enterprise Data Warehouse (EDW) was used to retrospectively collect data on patients undergoing RAPN for kidney tumor. Imaging was reviewed to assess RENAL and PADUA scores. Patients with multiple masses were excluded from nephrometry assessment as these tools are not validated in this setting. 


Results :

We analyzed 435 patients who had a planned RAPN. In 40 patients, intra-operative ultrasound made the surgeon change to LRP even before attempting RAPN and were therefore excluded from analysis. RAPN was converted to a different technique in 37 cases (9.3%): 22 cases to OPN (5.6%) and 15 to LRP (3.8%). We found no correlation between conversion and BMI, antiplatelelet / anticoagulant use, pre-operative diabetes or hypertension, but patients with chronic kidney disease (CKD, p=0.039) had increased risk of conversion. All converted cases with eGFR< 60 ml/min had OPN as an attempt to preserve nephrons.


Adherent perinephric fat (n=13) and gastrointestinal system factors (n=6, all converted to OPN) were the most common reasons for conversion. Male patients were more likely to be converted than female (11.4% vs. 6.3%), but this difference was not statistically significant on multivariate analysis (p=0.088). Previous abdominal surgery was found to be a significant risk factor for conversion (23.6% vs. 7.1%, p=0.006).


Tumor size was significantly bigger in converted cases (35 vs. 25 mm, p=0.001). Converted cases were more often tumors on the posterior surface (61.8%) with median R.E.N.A.L. score of 8 (range 4-11) and PADUA score of 10 (range 7-13). When examining individual parameters, nearness of the tumor to the collecting system had the highest median score (3). The typical converted tumor type was polar, more than 50% endophytic and less than 4mm from the collecting system. 


Conclusions :

Nephrometry parameters (particularly tumor size and nearness to the collecting system) are useful to risk stratify patients for the difficulty of completing a RAPN, but factors such as history of previous abdominal surgery can be as important. All this information helps doctors appropriately counsel patients about their risk of conversion even in experienced hands.

Ricardo O. Soares

Endourology Fellow
Northwestern University - Feinberg School of Medicine
Chicago, Illinois

MD and Urology residency in Portugal providing a solid and broad clinical experience in several urological areas with special interest in Uro-Oncology and Endourology.

Board certified since June 2013, following examination by the European Board of Urology.

For 3 years, worked as a Uro-Oncology Fellow in England (at University College of London Hospital and, from October 2013, at Royal Surrey County Hospital), including robotic / laparoscopic prostatectomy, robotic radical cystectomy, 4D LDR brachytherapy and blue-light cystoscopy. Completed the 6-month Certified Curriculum for Robotic Radical Prostatectomy of ERUS (European Associaton of Urology Robotic Urology Section).

Worked as Urology Attending in one of the top 5 Urology departments in England from August 2016 till June 2017, performing robotic prostatectomies, 4D LDR brachytherapy and General Urology.
Currently at Northwestern University, in Chicago, doing the 2-year Endourological Society Fellowship in robotic (prostate and kidney) and stone surgery.
Fluent in Portuguese (native), English, Spanish and French.
Permanent Resident in USA. Married, with one son.

https://uk.linkedin.com/in/ricardooliveirasoares

Ashima Singal

Urology Resident
Northwestern Unioversity - Feinberg School of Medicine
Chicago, Illinois

Vidit Talati

Medical Student
Northwestern University - Feinberg School of Medicine
Chicago, Illinois

Joshua Castle

Medical Student
Northwestern Unioversity - Feinberg School of Medicine
Chicago, Illinois

Kent T. Perry

Associate Professor of Urology
Northwestern University - Feinberg School of Medicine
Chicago, Illinois

Robert B. Nadler

Professor in Urology
Northwestern Unioversity - Feinberg School of Medicine
Chicago, Illinois