"Zero-Ischemia" Laparoscopic-assisted Partial Nephrectomy for the Management of Selected Children With Wilms Tumor Following Neoadjuvant Chemotherapy

The rationale for nephron-sparing surgery in unilateral non-syndromic Wilms tumour

The central question of nephron-sparing surgery in unilateral non-syndromic Wilms tumour sits at a crossroads between surgery, oncology, and nephrology. There has been a significant paradigm shift in paediatric oncology towards reducing toxicity and addressing long-term treatment-related sequalae amongst childhood cancer survivors. After paediatric nephrectomy and 30-50 years of follow-up, 40% of patients will have chronic kidney disease, including 22% with hypertension and 23% with albuminuria. It is difficult to predict which patients will progress to develop hypertension, reduced glomerular filtration rate, albuminuria, and a higher cardiovascular risk. For these reasons, nephron-sparing surgery when it is technically feasible must be considered. To decrease the incidence of positive surgical margins (viable tumour present at a resection margin), incomplete lymph node sampling, and complications, these procedures should be performed at specialist and experienced reference centres. Based on the impacts of individual treatment pathways, survivors of childhood WT need to be followed through adulthood for early detection of chronic kidney disease, hypertension, and prevention of cardiovascular events.

Robotic-assisted laparoscopic surgery for the treatment of Wilms' tumor in children: single-center experience and medium-term outcomes

To report our institutional experience and the medium-term outcomes of utilizing robotic-assisted laparoscopic surgery (RALS) in patients with Wilms' tumor (WT). The robotic surgical interventions include nephron-sparing surgery (RAL-NSS), radical nephrectomy (RAL-RN), and nephrectomy with inferior vena cava thrombectomy (RAL-N-IVCT). We retrospectively collected medical records of WT patients who underwent RALS in our center between August 2019 and February 2022. Patients' baseline demographics, preoperative parameters, and perioperative/postoperative data were recorded and analyzed. Follow-up results were collected to evaluate the oncological outcomes. A total of 12 patients (13 sides) with a median age of 30 (IQR: 19.5-45.5) months were included. All operations were successfully completed without conversion. Seven patients received preoperative chemotherapy. Distribution of surgical interventions was as follows: five patients underwent RAL-RN, five received RAL-NSS, one with bilateral WT underwent concurrent RAL-RN and RAL-NSS, and one received RAL-RN-IVCT post preoperative chemotherapy. Postoperative chemotherapy was conducted in ten patients. The estimated intraoperative blood loss was 27 ± 4.0 ml for the RAL-NSS group, 41.67 ± 12.13 ml for the RAL-RN group, and 350 ml for the RAL-RN-IVCT groups, respectively. The median perioperative serum creatinine levels were 32.5 (IQR: 30.75-39.5) μmol/l preoperatively and 35 (IQR: 31.75-38.5) μmol/l postoperatively, which showed no significant difference. No positive lymph nodes were detected. Postoperative chemotherapy was performed according to the tumor volume and pathological findings. The median follow-up time was 17.5 (15.8-22.3) months. During this interval, neither distant metastasis nor recurrence was identified. Based on our medium-term follow-up observations, RAL-NSS, RAL-RN, and RAL-RN-IVCT exhibit promising feasibility and safety profiles in the therapeutic landscape of WT.

Technical advances in the surgical management of Wilms tumors in children

Surgery is one of the cornerstones of Wilms tumor treatment. In this article, we present technical advancements that are finding their way into the armamentarium of pediatric cancer surgeons. We discuss the current approaches, challenges, opportunities, and future directions of minimally invasive surgery (laparoscopic and robotics), image-guided surgery, and fluorescence-guided surgery. Furthermore, we discuss the use of intraoperative ultrasonography, as well as the use of new techniques to improve the quality of lymph node sampling.

Nephron-sparing surgery for Wilms tumor

The algorithm that has been used successfully in the surgical management of unilateral Wilms tumor, radical nephroureterectomy, cannot be used in children who present with synchronous bilateral renal masses. Instead, a surgical approach that removes all tumor masses while preserving as much normal renal parenchyma as possible is encouraged to avoid acute and long-term renal insufficiency. We will review technical aspects of the conduct of nephron-sparing surgery for synchronous bilateral Wilms tumor, including the more recent advances in the use of imaging adjuncts such as pre-operative 3D imaging and fluorescence-guided surgery. The potential role of nephron-sparing surgery for unilateral Wilms tumor will also be discussed.

Nephron-sparing surgery in nonsyndromic unilateral wilms' tumor: An insight into the ongoing surgical controversy

Background:

Unilateral Wilms' tumor (uWT) is the most common renal malignancy in the pediatric population. Although the onset of surgical intervention like radical nephrectomy (RN) has substantially reduced the mortality rate, recent evidence has raised concerns regarding several postoperative complications associated with this procedure. Nephron-sparing surgery (NSS) has been reported to avoid such postoperative complications and have high technical success rate. However, not much literature is available comparing the efficacy of RN and NSS for managing nonsyndromic uWT, which makes it less acceptable globally.

Materials and Methods and Results:

A systematic identification of the literature was performed according to the Preferred Reporting Items for Systematic Reviews and Meta-analyses guidelines on four academic databases: MEDLINE, Scopus, EMBASE, and CENTRAL. Out of 1017 records, 20 manuscripts including 312 patients were included in the review; 4 patients treated by the author (unpublished data) have also been included. The studies included 7 retrospective case series with no comparison group, 4 retrospective case series with comparison group, 4 retrospective series with a cursory mention of NSS in uWT, 2 case reports, 1 protocolized prospective trial with comparison group, 1 administrative database analysis with comparison group, and 1 randomized controlled study. In all, 316 patients with nonsyndromic uWT were studied. The pretherapy volumes of the WT ranged from 2.4 to 640 ml. Majority of them were administered preoperative chemotherapy. About half of the patients (n = 159) (50.3%) were Stage I tumors. Stage II, III, and IV tumors were seen in 23 (7.3%), 20 (6.3%), and 3 (1%) patients. Stage was not specified in 111 (35.1%) patients. Majority of them were “intermediate risk” WT. All these tumors were nonanaplastic. Surgical margins were reported positive in 13 (4%) patients. Overall and event-free survivals were 100% in most of the studies; only handful of relapses were noted in this systematic review.

Conclusions:

This qualitative systematic review recommends the use of NSS for nonsyndromic uWT. The procedure accounts for higher postoperative renal function and lesser incidence of hypertension as compared to the radical nephrectomy. Overall and event-free survivals are comparable or even better with NSS.

Multidisciplinary Treatment Strategies for Wilms Tumor: Recent Advances, Technical Innovations and Future Directions

Significant progress has been made in the management of Wilms tumor (WT) in recent years, mostly as a result of collaborative efforts and the implementation of protocol-driven, multimodal therapy. This article offers a comprehensive overview of current multidisciplinary treatment strategies for WT, whilst also addressing recent technical innovations including nephron-sparing surgery (NSS) and minimally invasive approaches. In addition, surgical concepts for the treatment of metastatic disease, advances in tumor imaging technology and potentially prognostic biomarkers will be discussed. Current evidence suggests that, in experienced hands and selected cases, laparoscopic radical nephrectomy and laparoscopic-assisted partial nephrectomy for WT may offer the same outcome as the traditional open approach. While NSS is the standard procedure for bilateral WT, NSS has evolved as an alternative technique in patients with smaller unilateral WT and in cases with imminent renal failure. Metastatic disease of the lung or liver that is associated with WT is preferably treated with a three-drug chemotherapy and local radiation therapy. However, surgical sampling of lung nodules may be advisable in persistent nodules before whole lung irradiation is commenced. Several tumor markers such as loss of heterozygosity of chromosomes 1p/16q, 11p15 and gain of function at 1q are associated with an increased risk of recurrence or a decreased risk of overall survival in patients with WT. In summary, complete resection with tumor-free margins remains the primary surgical aim in WT, while NSS and minimally invasive approaches are only suitable in a subset of patients with smaller WT and low-risk disease. In the future, advances in tumor imaging technology may assist the surgeon in defining surgical resection margins and additional biomarkers may emerge as targets for development of new diagnostic tests and potential therapies.

Effectiveness of Nephron Sparing Surgery and Radical Nephrectomy in the Management of Unilateral Wilms Tumor: A Meta-Analysis

Background: Unilateral Wilms tumor is the most common renal malignancy in the pediatric population. Although the onset of surgical intervention like radical nephrectomy has substantially reduced the mortality rate, recent evidence has raised concerns regarding several postoperative complications associated with this procedure. Nephron sparing surgery has been reported to avoid such postoperative complications and have high technical success rate. However, no attempt to date has been made to synthesize the evidence comparing the efficacy of radical nephrectomy and nephron sparing surgery for managing unilateral Wilms tumor. Methods and Results: To metastatistically compare the efficiency of radical nephrectomy with nephron sparing surgery for managing unilateral Wilms tumor, a systematic identification of the literature was performed according to the Preferred Reporting Items for Systematic Reviews and Meta-analyses guidelines on four academic databases: MEDLINE, Scopus, EMBASE, and CENTRAL. A meta-analysis comparing renal function (estimated glomerular filtration rate), survival rate, and rate of relapse was performed to compare the efficacy of radical nephrectomy and nephron sparing surgery. Out of 1,283 records, 20 articles including 5,246 children (mean age, 4.3 ± 3.0 years) were included in this review. Radical nephrectomy was performed on 11 of the included studies, whereas nephron sparing surgery was performed on five studies. Two studies compared the efficacy of both interventions. The meta-analysis reveals the beneficial effects of nephron sparing surgery (Hedge's g, 0.76) as compared to radical nephrectomy (-0.16) for the estimated glomerular filtration rate for children with unilateral Wilms tumor. Moreover, higher survivability (0.59) and lesser occurrence of relapse were (-1.0) also reported for cases operated with nephron sparing surgery. Conclusion: The current meta-analysis recommends the use of nephron sparing surgery for unilateral Wilms tumor. The procedure accounts for higher survivability and postoperative renal function and lesser incidence of relapse as compared to radical nephrectomy.

Wilms tumor: a review of current surgical controversies

Overall survival (OS) for children with Wilms tumor (WT) currently stands at around 90%. This is markedly improved from the survival rates of around 30% reported in the middle of the last century. This improvement is due to the development of multimodal treatment for this disease, based on the evidence yielded through international collaboration on trials conducted by the Société Internationale d'Oncologie Pédiatrique (SIOP) and the Children’s Oncology Group (COG). In this article, we review some of the current surgical controversies surrounding the management of WT.

3D Model Facilitated Zero-Ischemia Laparoscopic Nephron Sparing Resection in Nephroblastomatosis Following the Addition of Cis-Retinoic Acid

There are limited reports of laparoscopic nephron sparing surgery (LNSS) in children and none where a 3D model facilitated oncological resection. There are also limited reports discussing the use of cis-retinoic acid in bilateral diffuse hyperplastic perilobar nephrogenic rests (DHPLNR). We report the first case of a 3D model facilitated zero-ischemia LNSS in children and the first following treatment with cis-retinoic acid. The patient was a 3-year-old girl with bilateral DHPLNR who had recurrent disease following standard therapy. She had suspicious lesions in the upper pole of the left kidney. Both were completely excised and histologically described as hyperplastic nephrogenic rests.

Volume and function of the operated kidney after nephron-sparing surgery for unilateral renal tumor

AIM

We sought to assess the magnitude of functional decline and the natural history of the operated kidney residual function after zero-ischemia nephron-sparing surgery (Z-NSS) in children with unilateral renal tumor (URT).

PATIENTS AND METHODS

50 children were treated for URT at our surgical unit between 1992 and 2016. Of these 12 who underwent Z-NSS were available for the current analysis. Operated kidney function was assessed by 99mTc-dimercapto-succinic acid (DMSA) renal scintigraphy. Operated kidney volume was assessed by renal ultrasonography.

RESULTS

A positive correlation between split renal function and split renal volume was found (P = 0.001). The subset of patients with ≥40% preservation of operated kidney function/volume (OKF/V) had no-time dependent changes during adolescence. The subset of patients with <40% OKF/V preservation had a catch-up growth that after puberty reached values not much different from those with ≥40% OKF/V preservation. At 5 years of follow-up, 3 of 5 patients with baseline dysfunction (eGFR between 40.8 and 89.4 ml/min/1.73 m²) presented with a global renal function within normal range. After puberty, all patients presented with global renal function within normal values (eGFR between 95 and 151 ml/min/1.73 m²).

CONCLUSIONS

In children with URT who underwent Z-NSS, the pattern of OKF/V recovery suggests that compensatory catch-up growth capacity during childhood minimizes OKF/V decline more than Z-NSS.

LEVEL OF EVIDENCE

Level I prognosis study - prospective cohort study with >80% follow-up and all patients enrolled at same time point in disease.

Retrospective analysis to determine outcomes of patients with bilateral Wilms tumor undergoing nephron sparing surgery: 15-year tertiary single-institution experience

PURPOSE

To describe our clinical experience with nephron sparing surgery (NSS) for bilateral Wilms tumor and evaluate the outcomes of patients treated at one of the largest pediatric medical centers in China.

METHODS

Medical records of children with bilateral Wilms tumor undergoing NSS in the Children's Hospital of Chongqing Medical University during a 15-year period were retrospectively analyzed. Data collected were composed of age at surgery, tumor response, tumor rupture during resection, final pathologic margins, use of radiation therapy, pathology reports, renal function, and patient survival.

RESULTS

A total of 18 eligible patients (10 males, 8 females) with bilateral Wilms tumor at a mean age of 2.28 ± 1.12 years were identified. The administration of preoperative chemotherapy did not result in universally successful outcomes. All children underwent successfully unilateral or bilateral NSS, of which one had positive pathologic margins and five received radiation therapy postoperatively. The rates of tumor rupture and positive lymph nodes involvement were 11.1 and 19.4%, respectively. The pathological study showed favorable histology and unfavorable histology in 32 and 4 kidneys, respectively. The 4-year event-free survival and overall survival rates were 68.18 and 85.56%. In univariable analysis, tumor histology (p = 0.0028) and disease stage (p = 0.0303) appeared significantly associated with overall survival. After a median follow-up period of 41.5 months (range 10-89), three of the surviving patients were diagnosed with hypertension and one had renal insufficiency.

CONCLUSIONS

Our experience suggests that NSS has become a feasible and effective option with good oncologic outcomes. Further research, ideally in a multicenter randomized manner, is warranted to better assess the role of NSS in this challenging clinical scenario.

Recent advances in the management of Wilms' tumor

The objective of this article is to present an overview of recent trends in the management of Wilms’ tumor. With improved survival rates in the past few decades, critical long-term adverse therapy effects (such as renal insufficiency, secondary malignancies, and heart failure) and prevention measures (i.e. nephron-sparing surgery and minimizing the use of radiotherapy) have gained worldwide attention. Specific disease biomarkers that could help stratify high-risk from low-risk patients, and therefore fine-tune management, are in great demand. Ultimately, we aim to enhance clinical outcomes and maintain or improve current survival rates while avoiding undesirable treatment side effects and minimizing the exposure and intensity of chemotherapy and radiotherapy.