Related Experiment Video
Updated: May 1, 2026
Author Spotlight: Developing a Bedside Protocol for Kidney and Genitourinary Ultrasonography
Published on: June 21, 2024
Intraoperative ultrasound in nephron-sparing surgery for paediatric renal tumours: A single-centre cohort study
Carolina Bebi1, Tom Watson2, Alberto Mantovani1
1Department of Paediatric Urology, Great Ormond Street Hospital for Children, London, United Kingdom.
Background:
Nephron-sparing surgery (NSS) for paediatric renal tumours seeks maximal parenchymal preservation. However, incomplete tumour excision often requires additional therapy impacting renal function. We evaluate the impact of intraoperative ultrasound on histological margins during NSS (US-NNS).
Methods:
All patients offered US-NSS (2016-2025) were recorded prospectively and compared to all historical NSS cases (2000-2016) undertaken without ultrasound (non-US-NSS). On-table US was performed by a consultant radiologist using a linear-array transducer on the renal capsule. NSS sought a rim of normal parenchyma and was used for multiple lesions when needed. Data included demographics, histology, surgical margins, and kidney/specimen volumes. Using the formula d1 × d2 × d3 × 0.523, pathological specimen volumes were subtracted from the pre-operative MRI renal unit volumes to determine the percentage of preserved parenchyma. Fisher's exact test compared margin positivity for malignant lesions.
Results:
The cohorts comprised 128 non-US-NSS in 51 patients (median age 28 months) and 39 US-NSS in 20 patients (median age 15.5 months). Histology for the 128 non-US-NSS were 64 Wilms tumours (WT), 13 equivocal WT, 51 non-malignant lesions, and for the 39 US-NSS 14 WT, 1 equivocal WT, 3 renal cell carcinoma (RCC), and 21 non-malignant lesions. The median specimen volumes per renal unit was 12.00 cm3 (IQR 4.01-28.5 cm3) vs 8.93 cm3 (IQR 3.34-17.89 cm3), and median preserved parenchyma per renal unit was 84.56% (IQR 62.71%-97.17%) vs 90.74% (IQR 74.20%-96.67%) in non-US-NSS vs US-NSS. Positive margins for malignant lesions occurred in 27/75 (36%) non-US-NSS, and in 0/18 US-NSS (p < 0.001).
Conclusion:
Intraoperative ultrasound for NSS eliminated positive margins for malignant lesions while maintaining high parenchymal preservation.
Insights
Intraoperative ultrasound during nephron-sparing surgery (NSS) significantly improved outcomes for paediatric renal tumours. This technique eliminated positive margins in malignant lesions, ensuring better oncological control while preserving kidney function.
Area of Science:
- Pediatric Urology
- Surgical Oncology
- Diagnostic Imaging
Background:
- Nephron-sparing surgery (NSS) is crucial for pediatric renal tumors, aiming to preserve maximal kidney parenchyma.
- Incomplete tumor excision during NSS can necessitate further treatment, potentially compromising renal function.
- Intraoperative ultrasound (US) is evaluated for its impact on histological margins during NSS.
Purpose of the Study:
- To assess the effectiveness of intraoperative ultrasound in improving histological margin status during nephron-sparing surgery for pediatric renal tumors.
- To compare parenchymal preservation rates between NSS with and without intraoperative ultrasound.
- To determine if intraoperative ultrasound reduces the need for additional therapies by ensuring complete tumor excision.
Main Methods:
- Prospective data collection for patients undergoing US-assisted NSS (US-NSS) from 2016-2025.
- Comparison with historical cohort of NSS performed without ultrasound (non-US-NSS) from 2000-2016.
- On-table ultrasound by a consultant radiologist; calculation of preserved parenchyma using pre-operative MRI and specimen volumes; Fisher's exact test for margin positivity in malignant lesions.
Main Results:
- The study included 128 non-US-NSS cases (51 patients) and 39 US-NSS cases (20 patients).
- Median preserved parenchyma was higher in the US-NSS group (90.74%) compared to the non-US-NSS group (84.56%).
- Crucially, positive margins for malignant lesions were eliminated in the US-NSS group (0/18) compared to the non-US-NSS group (27/75, 36%; p<0.001).
Conclusions:
- Intraoperative ultrasound during NSS for pediatric renal tumors effectively eliminates positive margins for malignant lesions.
- US-NSS maintains a high degree of renal parenchymal preservation.
- This approach enhances oncological safety and potentially reduces the need for adjuvant therapies, preserving renal function.
Related Concept Videos
01:24Imaging Studies II: Ultrasonography
01:28Imaging Studies I: Kidney, Ureter, and Bladder Studies
01:26Kidney Transplant II: Surgical Procedure
01:30Acute Kidney Injury IV: Diagnostic Studies and Prevention