Are nephrometry scores accurate for the prediction of outcomes in patients with renal angiomyolipoma treated with robot-assisted partial nephrectomy? A multi-institutional analysis

Predicting Bleeding Related Events in Robotic-Assisted Partial Nephrectomy for Angiomyolipoma: Simplifying Risk Assessment with Tumor Diameter and Depth, A Retrospective Study

Background

Evaluating risk factors for bleeding events in robot-assisted partial nephrectomy (RAPN) for renal angiomyolipoma (RAML) is essential for improving surgical outcomes.

Methods

We performed a retrospective analysis of patients who underwent RAPN for renal masses between May 2019 and June 2023 at a single medical center, categorizing them into AML and non-AML groups. We assessed demographic data, perioperative complications, and postoperative outcomes. Preoperative imaging was reviewed to calculate R.E.N.A.L and PADUA nephrometry scores. Receiver operating characteristic (ROC) curve analysis was used to evaluate the accuracy of risk factors related to estimated blood loss (EBL) and blood transfusion.

Results

Among 255 patients, 71 (27.8%) had AML, and 184 (72.2%) had non-AML. The average age was 54.5 years, with 80.2% of the AML group being female. The median tumor size was 50.2 mm. The AML group had larger tumor diameters (50.2 mm vs 34.9 mm) but shallower depths (16.1 mm vs 21.7 mm). Median R.E.N.A.L and PADUA scores were 6.5 and 8.2, respectively, with a median EBL of 128.2 mL. Blood transfusion was required in 15.5% of cases. Tumor diameter, depth, R.E.N.A.L score, and PADUA score significantly correlated with EBL, while BMI, tumor diameter, and R.E.N.A.L score correlated with blood transfusion. The AUCs for predicting EBL and blood transfusion were 0.778 and 0.771 for tumor diameter, and 0.661 and 0.711 for R.E.N.A.L score.

Conclusion

RAPN might be a safe option for RAML, with tumor diameter being the most accurate predictor of EBL and blood transfusion. These findings can improve preoperative assessments and surgical planning.

Management of renal sinus angiomyolipoma: modified robotic nephron-sparing surgery in a single center

BACKGROUND

Renal sinus angiomyolipoma (RSAML) is a rare and typically complex renal tumor. The objective is to present our single-center experience with a modified technique of robotic nephron-sparing surgery (NSS) for treating RSAML.

METHODS

We retrospectively evaluated 15 patients with RSAMLs who were treated with robotic NSS at the Department of Urology of Tongji hospital, ranging from November 2018 to September 2022. Renal vessels and ureter were dissected. The outer part of RSAML was resected. The rest of tumor was removed by bluntly grasp, curettage and suction. Absorbable gelatin sponges were filled in the renal sinus. The preoperative parameters, operative measures and postoperative outcomes were all collected. Follow-up was performed by ultrasonography and estimated glomerular filtration rate (eGFR).

RESULTS

Robotic NSS was successfully performed in all the patients, without any conversion to open surgery or nephrectomy. The mean operation time was 134.13 ± 40.56 min. The mean warm ischemia time was 25.73 ± 3.28 min. The median estimated blood loss was 100 [50, 270] ml and 1 patient required blood transfusion. The mean drainage duration was 5.77 ± 1.98 days. The median postoperative hospital stay was 6.90 [5.80, 8.70] days. Two patients experienced postoperative urinary tract infection (Clavien-Dindo Grade II). During the median follow-up of 25.53 ± 15.28 months, patients received 91.18% renal function preservation. No local recurrence occurred in all the patients.

CONCLUSIONS

Robotic NSS for RSAML is a complicated procedure that demands technical expertise and a well-designed strategy is critical in the operation. Treating RSAML with modified robotic NSS is safe, effective and feasible.