Laparoscopic treatment of renal cancer in children: a multicentric study and review of oncologic and surgical complications

Laparoscopic Treatment of Wilms' Tumor: Criteria of SIOP-UMBRELLA Protocol may be Updated

INTRODUCTION

Total nephrectomies for the treatment of Wilms' tumor (WT) are more and more performed by laparoscopy, although indications for this approach following the UMBRELLA guidelines are currently very restrictive. The purpose of this study was to assess the compliance to the criteria of the UMBRELLA protocol for minimally invasive approach of WT.

METHODS

This retrospective multicenter study included children operated on by laparoscopic total nephrectomy for suspected WT before 2020. Imaging was reviewed centrally.

RESULTS

Fifty-six patients (50 WT and 6 nephrogenic rests) were operated on at a median age of 3.3 ± 2.6 years. Thirteen (23%) patients had metastasis at diagnosis. The mean operative time was 213 ± 84 min. There were eight (14.3%) conversions and five peroperative complications. A local stage III was confirmed in seven (12.5%) cases, including two for tumor rupture. Only one (1.8%) of the procedures followed the SIOP-UMBRELLA indications for laparoscopy. The criterion "ring of normal parenchyma" was met only once. Conservative surgery seemed possible in ten (17.9%) cases. The extension of the tumor beyond the ipsilateral edge of the vertebra after chemotherapy and a volume over 200 mL were associated with an increased risk of conversion (p = 0.0004 and p = 0.001 respectively). After a mean follow-up of 5.2 ± 4.0 years, although there was no local recurrence, one death occurred due to metastatic progression at 15 months postoperatively.

CONCLUSIONS

The laparoscopic approach of WT beyond the UMBRELLA recommendations was feasible with low risk of local recurrence. Its indications may be updated and validated.

Robotic-assisted Pediatric Thoracic and Abdominal Tumor Resection: An Initial Multi-center Review

INTRODUCTION

Robotic-assisted minimally invasive surgery (RA-MIS) for tumor resection is an emerging technology in the pediatric population with significant promise but unproven safety and feasibility.

METHODS

A multi-center retrospective review of patients ≤18 years undergoing RA-MIS tumor resection from December 2015-March 2023 was performed. Patient demographics, perioperative variables, and complication rates were analyzed.

RESULTS

Thirty-nine procedures were performed on 38 patients (17 thoracic, 22 abdominal); 37% female and 68% non-Hispanic White. Median age at surgery was 8.3 years (IQR 5.7, 15.7); the youngest was 1.7 years-old. Thoracic operations included resections of neuroblastic tumors (n = 16) and a single paraganglioma. The most common abdominal operations included resections of neuroblastic tumors (n = 5), pheochromocytomas (n = 3), and angiomyolipomas (n = 3). Six patients underwent retroperitoneal lymph node dissection (RPLND) for paratesticular tumors. Median operating time for the cohort was 2:52 h (IQR 2:04, 4:31). Two thoracic cases required open conversion due to poor visualization and lack of working domain. All patients underwent complete tumor resection; one had tumor spillage from a positive margin (Wilms tumor). Median LOS was 1.5 days (IQR 1.1, 3.0). Postoperatively, one patient developed a chyle leak requiring interventional radiology drainage, but none required a return to the operating room.

CONCLUSIONS

Robotic-assisted surgery is safe and feasible for tumor resection in carefully selected pediatric patients, achieving complete resection with minimal morbidity and short LOS. Resection should be performed by those with robotic expertise for optimal outcomes.

LEVEL OF EVIDENCE

IV.

TYPE OF STUDY

Original Clinical Research.

Minimally invasive and robotic-assisted approaches applied to pediatric surgical oncology

The management of pediatric tumors is complex, with surgery, chemotherapy, and radiotherapy being cornerstones in their treatment. Tumor removal is increasingly performed by a minimally invasive approach, which allows for quicker postoperative recovery and less postoperative pain. The goal of this report is to give an overview of minimally invasive surgical approaches for common pediatric tumors, with a focus on technical considerations and postoperative outcomes.

Indocyanine green fluorescence imaging-assisted laparoscopy resection of retroperitoneal tumors in children: case report and literature review

This study examined the applicability of indocyanine green (ICG) fluorescence imaging to assist the laparoscopic resection of retroperitoneal tumors in pediatric patients via an abdominal approach. Conducted prospectively at the Guangzhou Women and Children's Medical Center from May to September 2023, the research included three pediatric cases, for whom laparoscopic retroperitoneal tumor resections were performed utilizing ICG fluorescence imaging. In each case, ICG was intravenously administered (0.3 mg/kg) prior to surgery, enabling the visualization of vital vascular structures through real-time fluorescence imaging. The trocar's placement was guided by a "four-hole" technique from the healthy side in a 70-degree lateral decubitus position. The operations were accomplished successfully without any complications. Pathological analysis of the patients identified one case of Wilms tumor of the embryonal type, one ganglioneuroblastoma of the mature type without N-MYC gene amplification, and one mature cystic teratoma. The findings suggest that with careful patient selection and skilled surgical execution, the utilization of ICG fluorescence imaging in the laparoscopic resection of retroperitoneal tumors is both safe and effective in children. This approach significantly improves the visualization of critical blood vessels, thus enhancing surgical safety.

Systematic Review and Meta-analysis of Laparoscopic Versus Open Radical Nephrectomy for Paediatric Renal Tumors With Focus on Wilms' Tumor

OBJECTIVE

To summarize and evaluate the outcomes of laparoscopic radical nephrectomy (LRN) and compare its safety and efficacy with open radical nephrectomy (ORN) in pediatric renal tumors (RT) and Wilms' tumors (WT).

BACKGROUND

ORN is the gold standard treatment for pediatric RT, consisting predominantly of WT. LRN is gaining popularity but remains controversial in pediatric surgical oncology.

METHODS

A systematic search was performed for all eligible studies on LRN and comparative studies between LRN and ORN in pediatric RT and WT. Meta-analysis, subgroup analysis, and sensitivity analysis were conducted. The main endpoints were cancer-related outcomes and surgical morbidity. Preferred Reporting Items for Systematic Reviews and Meta-analyses guidelines were followed.

RESULTS

No levels I to II studies were identified. LRN was feasible in nearly 1 in 5 pediatric RT and WT after neoadjuvant chemotherapy, with pooled mid-term oncological outcomes (<7% local recurrence, >90% event-free survival) comparable with those of ORN. There was no strong evidence of an increased risk of intraoperative tumor spillage, but lymph node harvest was inadequate in LRN. Large tumors crossing the ipsilateral spinal border were associated with a trend for intraoperative complications and positive margins. Pooled complications rate and hospital stay duration were similar between LRN and ORN. Long-term (>3 years) outcomes are unknown.

CONCLUSIONS

Available level III evidence indicates that LRN is a safe alternative to ORN for carefully selected cases, with similar spillage rates and mid-term oncological outcomes. However, there was no advantage in surgical morbidity and lymph node harvest was inadequate with LRN. Tumor-matched-group studies with long-term follow-up are required.

LEVEL OF EVIDENCE

Level III.

[Laparoscopic nephrectomies and kidney resections in children]

OBJECTIVE

To present the experience of laparoscopic nephrectomies and kidney resections in children.

MATERIAL AND METHODS

There were 28 minimally invasive surgeries for renal tumors between July 2015 and March 2023 (92 months). There were 16 (57%) boys and 12 (43%) girls who underwent 22 nephrectomies and 6 kidney resections. The median age of patients was 54 (38; 76.5) months.

RESULTS

In the laparoscopic nephrectomy group, the median surgery time was 135 (108-188) min, blood loss - 10 (3.75-15) ml. Total resection was confirmed in all patients. In the group of minimally invasive kidney resections, these values were 182.5 (157.5; 265) min and 50 (42.5; 117.5) ml, respectively. Histological examination confirmed total resection in all patients. In both groups, none patient developed postoperative complications. Event-free survival was 86.72% with a median follow-up of 82 months, and local recurrence-free survival was 95.8% with a median follow-up of 89.8 months.

CONCLUSION

Minimally invasive nephrectomies and resections are safe in children in case of careful patient selection.

Renal cell carcinoma in the pediatric population: A case report and review of the literature

Renal cell carcinoma is a cancer thought to originate from renal epithelial cells. Commonly seen in patients older than 60 years of age, renal cell carcinoma presents as rare pathological entity seen in urological cancers among the pediatric population. A 17-year-old female patient presented with complaints of intermittency, dysuria, and gross hematuria. Radiological imaging was in favor of a left renal mass. Under general anesthesia, the left kidney was completely laparoscopically resected and sent to pathology, which along with correlating the age group of the patient and the morphology on pathological analysis, was suggestive of microphthalmia family translocation renal cell carcinoma.

Outcomes of event-free survival in patients with Wilms tumor undergoing preoperative chemotherapy. Analysis of lymph-node yield in a single-center cohort

INTRODUCTION

The clinical value of lymph node sampling in Wilms tumor (WT) lies in its ability to accurately determine lymph node (LN) involvement. LN yield (LNY) is used as a valuable tool to measure LN retrieval, and a minimum of 6 LNs is one of the current recommendations. In patients who are managed with the SIOP strategy, preoperative chemotherapy decreases the retrieval of LN during surgery resulting in lower LNY values.

PURPOSE

To determine the mean LNY and to analyze survival outcomes in patients with WT who underwent preoperative chemotherapy at a single center.

METHODS

We performed a retrospective chart review of all patients between 6 months and 12 years of age with unilateral WT who underwent preoperative chemotherapy between 2010 and 2018. Patients with bilateral WT or without preoperative chemotherapy were excluded. Collected data included: demographics, tumor volume, tumor histopathology, number of LNs collected (LNY), presence or absence of tumor in the retrieved LNs, and disease stage according to these results. Kaplan Meier curves were calculated to estimate 5-year event-free survival (EFS) and overall survival (OS).

RESULTS

95 patients with a median follow-up of 25 months were included in the study. A total of 19 patients underwent laparoscopic surgery. Mean LNY for the entire cohort was 3.26 (95% CI, 2.4-3.6; SD, 3.62). Six patients (6.3%) had at least one positive LN. The estimated 5-year OS was 89.3% (95% CI, 82.1%-96.5%). EFS was 79.8 (95% CI, 74.8%-84.8%). Recurrence rate was 20% (n: 19). Four patients (4.2%) developed local recurrence and 15 patients (15.7%) developed pulmonary recurrence. The initial mean LNY in patients that relapsed was 4.16 (95% CI, 2.2-5.8; SD: 4.18), which was higher than in patients who did not relapse (LNY: 3; 95% CI, 2.33-3.67; SD, 3.39). No recurrences or deaths occurred in the laparoscopic group.

DISCUSSION

The identification of a minimum LNY (i.e. threshold) to minimize the risk of harboring occult metastatic disease has been proposed to standardize the surgical procedure. Preliminary results in this study suggest that a limited LNY with acceptable survival outcomes is a possible scenario in patients treated according to the SIOP protocol. Systematic LN sampling to reduce the rate of false negatives is still strongly recommended.

CONCLUSION

Our cohort presented with a relatively low LNY compared to standard recommendations. Our EFS, however, remained acceptable. Multivariate analysis would be necessary to determine the actual role of LN sampling as an isolated prognostic factor in unilateral WT.

A single centre matched pair series comparing minimally invasive and open surgery for the resection of pediatric renal tumours

INTRODUCTION

Minimally invasive nephrectomy (MIN)for the resection of pediatric renal tumors is controversial. We compared patients who underwent laparoscopic MIN according to our unit protocol with matched patients who underwent open surgery (ON).

METHOD

A single centre retrospective analysis of prospectively collected data for MIN. Tumor volume was calculated from pre-operative imaging and volume matched ON patients were identified from the regional tumor database. Demographics, complications, operative time, length of stay, number of nodes resected, status of margins, radiotherapy (RT)requirement, length of follow-up and outcomes were analysed.

RESULTS

Fourteen MINs performed between September 2016 and 11/2019 (M:F 5:9; median age 37 (range 2-73)months) were matched with ON controls (7:7 M:F, median age 42 (1-74)months). Diagnoses in the MIN group were Wilms Tumour (WT)in11 and one each of mesoblastic nephroma (MN), malignant rhabdoid tumour of the kidney (MRTK), nephroblastomatosis and in the ON group were 13 WT and 1 MN. Median operating time for MIN was 180 (125-300)minutes, with 4 conversions and 155 (1-3-480)minutes in ON. There were no intra-operative ruptures. Three tumors in each group had positive margins. A median of 4 (0-6) nodes were removed during MIN and 4 (2-22) during ON. Median length of stay (LoS)was 4 (2-15)days following MIN and 4 (2-9) following MIN. Six ON and 3 MIN patients required radiotherapy. Differences were not significant. Median follow up of 30 (6-44)months for MIN and 73 (34-109)months for ON patients was significantly different. There have been no local recurrences but the child with MRTK died following brain tumor recurrence.

CONCLUSION

MIN for pediatric renal tumors has similar short term outcomes to ON in carefully selected patients.

Minimally invasive surgery for pediatric renal tumors: A systematic review by the APSA Cancer Committee

Minimally invasive nephrectomy is performed routinely for adult renal tumors and for many benign pediatric conditions. Although open radical nephroureterectomy remains the standard of care for Wilms tumor and most pediatric renal malignancies, there are an increasing number of reports of minimally invasive surgery (MIS) for those operations as well. The APSA Cancer Committee performed a systematic review to better understand the risks and benefits of MIS in pediatric patients with renal tumors.

METHODS

The search focused on MIS for renal tumors in children and followed the Preferred Reporting Items for Systematic Review and Meta-Analysis (PRISMA) checklist. The initial database search identified 491 published articles, and after progressive review of abstracts and full-length articles, 19 were included in this review.

RESULTS

There were two direct comparison studies where open surgery and MIS were compared. The remaining studies reported only on minimally invasive nephrectomy. Across all studies, there were a total of 151 patients, 126 of which had Wilms tumor and 10 patients had RCC. 104 patients had MIS, with 47 patients having open surgery. In the two studies in which open surgery and MIS were directly compared, more lymph nodes were harvested during open surgery (median = 2 (MIS) vs 5 (open); mean = 2.47 (MIS) vs 3.8 (open)). Many noncomparison studies reported the harvest of 2 of fewer lymph nodes for Wilms tumor. Several MIS patients were also noted to have intraoperative spill or positive margins. Survival between groups was similar.

CONCLUSIONS

There is a lack of evidence to support MIS for pediatric renal tumors. This review demonstrates that lymph node harvest has been inadequate for MIS pediatric nephrectomy and there appears to be an increased risk for intraoperative spill. Survival data are similar between groups, but follow-up times were inconsistent and patient selection was clearly biased, with only small tumors being selected for MIS.

TYPE OF STUDY

Review article.

LEVEL OF EVIDENCE

III.

Minimally invasive surgery for unilateral Wilms tumors: Multicenter retrospective analysis of 50 transperitoneal laparoscopic total nephrectomies

PURPOSE

To evaluate feasibility and outcomes of minimally invasive surgery (MIS) in Wilms tumor (WT).

METHODS

International multicenter review of MIS total nephrectomies for WT between 2006 and 2018. Medical records of confirmed WT were retrospectively assessed for demographic, imaging, treatment, pathology, and oncological outcome data.

RESULTS

Fifty patients, with a median age of 38 months (6-181), were included in 10 centers. All patients received neoadjuvant chemotherapy, as per SIOP protocol. Median tumor volume post-chemotherapy was 673 mL (18-3331), 16 tumors crossed the lateral border of the spine, and three crossed the midline. Six patients with tumors that crossed the lateral border of the spine (tumor volumes 1560 mL [299-2480]) were converted to an open approach. There was no intraoperative tumor rupture. Overall, MIS was completed in 19% of the 195 nephrectomies for WT presenting during the study period. Tumor was stage I in 29, II in 16, and III in 5, and histology was reported as low in three, intermediate in 42, and high risk in five. Three patients had positive tumor margins. After a median follow-up of 34 months (2-138), there were two local recurrences (both stage I, intermediate risk, 7 and 9 months after surgery) and one metastatic relapse (stage III, high risk, four months after surgery). The three-year event-free survival was 94%.

CONCLUSION

MIS is feasible in 20% of WT, with oncological outcomes comparable with open surgery, no intraoperative rupture, and a low rate of local relapse. Ongoing surveillance is, however, needed to evaluate this technique as it becomes widespread.

Pediatric minimally invasive surgery for malignant abdominal tumor: Single center experience

This study examined the safety and usefulness of minimally invasive surgery (MIS) for malignant abdominal tumors in pediatric patients and analyzed the factors affecting the resection margin, operative time, and hospital stay of neuroblastoma (NBL) patients.We retrospectively reviewed data of pediatric patients who underwent MIS for malignant abdominal tumors from January 2011 to June 2017 at the Seoul National University Children's Hospital. Sex; age at operation; diagnosis; tumor location; operation-related data, such as operation time and transfusion; and follow-up data were reviewed. We divided patients into an excision group and a biopsy group. Detailed pathologic data were reviewed to analyze factors affecting the resection margin of NBL. Median value and range were calculated for all continuous variables. Mann-Whitney test and χ test were used as appropriate. P values of <.05 were considered significant.Thirty-four pediatric patients were included; 21 were boys. The median age was 4 (0.2-18) years. The most common diagnosis was NBL (17 patients; 50.0%). Three patients each were diagnosed with lymphoma, solid pseudopapillary tumor of the pancreas, and teratoma. The median tumor size was 3.4 (0.5-10.2) cm. The median operation time was 108 (55-290) minutes, and the median hospital stay was 5 (2-11) days. The number of conversions to open surgery was 4. There were no postoperative complications or mortality. There were 18 patients in the excision group and 16 in the biopsy group. Diagnosis and the number of patients receiving preoperative chemotherapy differed between the 2 groups. R0 resection of NBL was significantly higher in patients with stage 1 disease and those aged >2 years. There were no clinical factors influencing operative time or hospital stay.MIS was feasible and safe in pediatric patients with malignant abdominal tumors. R0 resection of NBL was related to age and stage.

Robotic-assisted laparoscopic management of renal tumors in children: Preliminary results

AIM

We present the preliminary results of robotic-assisted laparoscopic (RAL) total and partial nephrectomy for renal malignant tumors in children.

METHODS

This is a prospective study of patients operated with RAL between December 2016 and September 2018. Patients with Wilms tumors were treated according to the SIOP-2001 protocol. Patient and tumor characteristics, type of surgery, surgical-related morbidity, and oncologic outcomes were recorded. Results were compared with a series of patients with similar age- and tumor-related characteristics operated during the same period by an open surgical approach.

RESULTS

Ten children underwent RAL nephrectomy with a mean age of five years (3.2-14.1 years). Total nephrectomy was done in six cases for Wilms tumor and in one case for renal sarcoma; three cases were converted. Complete removal of tumor without rupture was achieved in all cases. Postoperative course was uneventful, and patients were discharged between days 2 and 7. Neither recurrence nor medium-term complications occurred. Nine patients are alive with a median follow-up of 16 months (6-27 months) and one female died from complications of central nervous system metastases one year after surgery. When compared with the open surgical approach group, median tumor volume was smaller (P = 0.005), hospital stay was shorter (P = 0.01), and operative time was similar (P = 0.20).

CONCLUSIONS

RAL total and partial nephrectomy procedure for renal tumor in children may be an option in carefully selected cases. Indication should be discussed at tumor boards and surgery performed while adhering strictly to oncological surgical rules.

Ossifying Renal Tumor of Infancy: Laparoscopic Treatment and Literature Review

We present an unusual case of a rare ossifying renal tumor of infancy. A 6-month-old male initially presented with gross hematuria and without any palpable abdominal mass. Renal ultrasound and MRI showed a right lower pole, calcified, endophytic renal mass. Laparoscopic radical nephrectomy was performed without complications. Pathology demonstrated an ossifying renal tumor of infancy. We report this case, in addition to a review of the literature for similar cases, to highlight a rare renal tumor in infancy that can be managed laparoscopically.

Minimally Invasive Approaches to Pediatric Solid Tumors

Over the last decade, driven in part by the favorable adult experience and a crescendoing number of case series and retrospective reports in the pediatric surgical literature, minimally invasive surgical (MIS) approaches are increasingly used as adjunctive or definitive surgical treatments for an ever-expanding list of pediatric tumors. Although most current treatment protocols lack surgical guidelines regarding the use of MIS, this growing body of MIS literature provides a framework for the development of multicenter trial groups, prospective registries, and further centralization of subspecialist services. This article highlights the current available data on MIS approaches to a variety of pediatric malignancies.

Laparoscopic total nephrectomy for Wilms tumor: Towards new standards of care

INTRODUCTION

Laparoscopic total nephrectomy (LN) in malignant pediatric tumors remains controversial. For selected patients undergoing pre-operative chemotherapy in referral centers, LN has so far shown comparable results to the standard open technique.

PURPOSE

To describe the inclusion criteria and preliminary results of laparoscopic nephrectomies (LN) for the treatment of unilateral Wilms tumors (WT).

MATERIAL AND METHODS

Between November 2010 and January 2016, a retrospective study of patients with WT and undergoing pre-operative chemotherapy was performed. Inclusion criteria for candidates for LN were: unilateral tumors without venous invasion and central kidney localization. Tumor size and vascular thrombus were estimated with pre-operative computed tomography (CT) scan. Overall survival and recurrence rates were evaluated.

RESULTS

Among 105 patients with WT, 14 underwent LN. Tumor bleeding or the lack of response to chemotherapy were not exclusion criteria. Median tumor volume for the patients undergoing LN was 71.5 cc (range 7-169). Patients with small tumors localized near the renal pole and candidates for nephron sparing surgery (NSS) were excluded. Estimated 5-year overall survival for all patients with WT during this period was 88.7% (88.1-103.1). Two patients underwent conversion. No recurrence or related death was found at a mean 32- month follow-up period.

DISCUSSION

Reproducing the steps of the open nephrectomy when performing LN for malignant tumors allowed comparable oncologic results to the conventional procedure. However, upstaging of the tumor was not admissible and has become the main goal when approaching these patients laparoscopically. Preliminary results showed that the incidence of intraoperative rupture and incomplete node sampling were not an issue when comparing LN to open nephrectomy. On the other hand, LN for malignant tumors requires experience in advanced laparoscopy and oncologic surgery. Pre-operative chemotherapy changes the tumor's consistency and this is the key point as to why these patients are amenable to be approached laparoscopically. Lifting the tumor along with the fat to avoid capsule fraction, as well as changing the lens to the lateral port to achieve a correct view for lymph node sampling are some of the considerations when performing LN.

CONCLUSIONS

Preliminary data suggest that LN for WT is feasible and has promising results in terms of event-free and overall survival. In patients undergoing pre-operative chemotherapy the correct selection for LN is crucial. Following the basic oncological precepts and in experienced centers, LN represents a plausible modality in the care of these patients.

Laparoscopic nephrectomy for Wilms' tumor: Can we expand on the current SIOP criteria?

INTRODUCTION

Wilms' tumor now has a good overall prognosis with open radical nephrectomy having been the mainstay of surgical treatment. Recently laparoscopic nephrectomy (LN) has been growing in popularity. The aim of our study was to review our indications and outcomes for laparoscopic resections for Wilms' tumor and compare indications with International Society of Paediatric Oncology (SIOP) criteria for LN.

MATERIAL AND METHODS

Patient demographics, preoperative management, surgical data, respect of SIOP criteria, complications, disease outcome, and follow-up were recorded on consecutive children who underwent nephrectomy for Wilms' tumor.

RESULTS AND DISCUSSION

Fifty-four consecutive children with Wilms' tumor underwent a nephrectomy; 20 had a LN (Table). Nine of 20 (45%) patients who had LN did not meet SIOP criteria for LN. No patients had an intraoperative tumor rupture and one patient had positive margins because of preoperative rupture. There were two conversions: one caused by difficulty accessing the renal hilum and the other caused by difficulty maintaining oxygen saturations. There was one local recurrence.

CONCLUSION

SIOP criteria are conservative and safe. Indications can be extended for teams experienced in surgical oncology and laparoscopy after agreement at a multidisciplinary meeting (MDM).

Feasibility of laparoscopic tumour nephrectomy in children

AIMS

The laparoscopic approach to tumour nephrectomy in children is controversial. We therefore reviewed our institution's cases of tumour nephrectomy (laparoscopic, open, and converted) to better understand which is suitable for this approach, what factors prevent it, and whether one can excise tumours greater than the CCLG recommendation of 300 ml.

METHODS

All tumour nephrectomies performed between 2002 and 2016 were identified using our surgical database. Further data were gathered from radiology and pathology databases. Those with nonrenal tumours or having a partial nephrectomy were excluded. Tumour maximum diameters, volumes, and ratios to contralateral kidneys were calculated. A Mann-Whitney U was used to compare the groups.

RESULTS

Forty-three cases were included. Fifteen procedures were completed laparoscopically (35%), and a further 3 converted. The median age at surgery was 2.5 years (range 0-10) in the laparoscopic group and 2 years (range 0-15) in the open group. There was a significant difference (P < 0.05) between the laparoscopic and open groups for: median maximum diameter (10cm vs 12.25cm), median volume (155 ml vs 459 ml), maximum diameter ratio (1.22 vs 1.75), and volume ratio (3.8 vs 11.2).

CONCLUSION

Tumours in the laparoscopic group were significantly smaller, but it was possible to excise tumours more than 300 ml. Difficulties in excision related to tumour size relative to the abdomen. Therefore, a ratio of tumour to contralateral kidney may be a better guide to safe excision than an overall volume cutoff. From our series, the laparoscopic approach is likely to be achievable if the volume ratio is ≤ 8.1.

LEVEL OF EVIDENCE

Level 3.

Comparing oncologic outcomes after minimally invasive and open surgery for pediatric neuroblastoma and Wilms tumor

BACKGROUND

Minimally invasive surgery (MIS) has been widely adopted for common operations in pediatric surgery; however, its role in childhood tumors is limited by concerns about oncologic outcomes. We compared open and MIS approaches for pediatric neuroblastoma and Wilms tumor (WT) using a national database.

METHODS

The National Cancer Data Base from 2010 to 2012 was queried for cases of neuroblastoma and WT in children ≤21 years old. Children were classified as receiving open or MIS surgery for definitive resection, with clinical outcomes compared using a propensity matching methodology (two open:one MIS).

RESULTS

For children with neuroblastoma, 17% (98 of 579) underwent MIS, while only 5% of children with WT (35 of 695) had an MIS approach for tumor resection. After propensity matching, there was no difference between open and MIS surgery for either tumor for 30-day mortality, readmissions, surgical margin status, and 1- and 3-year survival. However, in both tumors, open surgery more often evaluated lymph nodes and had larger lymph node harvest.

CONCLUSION

Our retrospective review suggests that the use of MIS appears to be a safe method of oncologic resection for select children with neuroblastoma and WT. Further research should clarify which children are the optimal candidates for this approach.

Distinguishing pediatric and adolescent renal cell carcinoma from other renal malignancies

PURPOSE

Renal cell carcinoma (RCC) represents a small proportion of renal malignancies early in life. Distinguishing RCC from other malignancies is important as treatment strategies may differ. We analyze the Surveillance Epidemiology, and End Results (SEER) database to identify predictive factors of RCC in the pediatric population with renal tumors.

METHODS

We queried SEER to identify patients from ages 0 to 19 diagnosed with a renal malignancy between 1973 and 2013. Cases were sorted using histology and site codes. Age-adjusted standardized incidence rates (SIR) were calculated. We compared differences in characteristics between cancer types. A logistic regression model and a nomogram were created to identify predictors of RCC.

RESULTS

A total of 3,670 patients were identified, of which 281 (7.7%) were diagnosed with RCC. The SIR of RCC increased with age. After age 12, RCC was found in >50% of all newly diagnosed cases. On multivariate analysis, RCC was associated with smaller tumor size (P < 0.001), increasing age (P < 0.001), black race (P < 0.001), and localized stage (P < 0.001). The nomogram predicted RCC pathology with a concordance index of 0.965.

CONCLUSIONS

RCC in childhood and adolescence is relatively uncommon; however, it accounts for >50% of renal malignancies after age 12. For every year of increasing age, the odds of having an RCC diagnosis are increased by 50%. The odds of a renal tumor being RCC are increased in black children, those with localized disease, and those with smaller tumors. In these specific populations, RCC should be favored in the differential diagnosis of the renal mass.

The Evolving Role of Minimally Invasive Surgery in Pediatric and Adolescent Urologic Oncology

OBJECTIVE

This review aims at evaluating the current status of minimally invasive surgery at the difficult crossroad between the attractiveness of innovation faced against the solid outcomes offered by the current gold standard, specifically concerning pediatric and adolescent urologic oncology conditions.

METHODS

This is a critical review of the literature and current paradigms on the use of minimally invasive surgery for pediatric and adolescent urologic oncology cancers. Focus is mainly on the use of laparoscopy for the treatment of Wilms' tumors but other neoplasms are also discussed.

RESULTS

We draw parallels with other similar pathologies, respecting critical lessons from international cooperative study groups. We discuss various aspects of the pros and cons of minimally invasive surgery in this patient population and make a case for the development of dedicated pediatric surgeons for urologic cancer.

CONCLUSION

Herein we draft a proposal suggesting a way forward with the adoption of reasonable paradigm shifts founded on carefully conducted studies for the introduction of minimally invasive surgery in the care of pediatric and adolescent urologic cancer.

Videolaparoscopic radical nephrectomy after chemotherapy in the treatment of Wilms' tumor: Long-term results of a pioneer group

INTRODUCTION

A high cure rate for Wilms' tumor has been achieved using a multidisciplinary approach. The natural step forward is to offer the benefits of a minimally invasive technique for surgery, which is an obligatory part of treatment. Nevertheless, some authors resist using videolaparoscopic radical nephrectomy (VRN) because of concerns about reducing the cure index.

METHODS

The present study included children with unilateral Wilms' tumor treated from December 2003 to December 2015 with neoadjuvant chemotherapy followed by VRN. Patients were selected based on the size of their tumors compared with the contralateral kidney, and on their stature.

RESULTS

VRN was performed in 24 patients of age range 10-93 months, with an average of 38.04 ± 23.37 months. The tumoral kidney's largest diameter after chemotherapy averaged 10% of a patient's height. There was no tumor rupture or spillage and no patient presented intra or immediate postoperative complications, except for prolonged ileum in two patients. One patient required intraoperative transfusion because of preoperative anemia. Another developed a late herniation in the umbilical port that required surgical correction. After an average of 6.65 years of follow-up, two patients presented relapse: one with a stage IV disease had relapse in the lung and another with a stage III, involving the liver, had local relapse because of an unwanted delay in the adjuvant treatment.

CONCLUSION

VRN can be considered a feasible alternative to open surgery in selected cases of children with Wilms' tumor. The present experience shows that besides the benefits of minimally invasive procedures and better cosmetic results, there is no evidence of increased tumor rupture or spillage, peritoneal or port site metastasis, and the long-term oncological results are the same as open procedures.

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

OBJECTIVE

To describe the experience and technique of zero-ischemia laparoscopic-assisted partial nephrectomy at The Hospital for Sick Children, as an alternative to the traditional open approach for nephron-sparing surgery (NSS) in selected children with Wilms tumor (WT).

MATERIALS AND METHODS

Patients with diagnosis of WT treated with neoadjuvant chemotherapy and who underwent laparoscopic-assisted NSS at the Hospital for Sick Children from 2012 to 2016 were identified and their charts were reviewed retrospectively. Patients underwent laparoscopic exploration, lymph node sampling, kidney mobilization, vascular control, and adrenal sparing. This was followed by open NSS through a small flank incision; no clamping of the hilum or major renal branches was performed.

RESULTS

Six patients were identified; all patients underwent successful resection. One patient required radical nephrectomy due to inability to safely define negative margins. Tumors ranged in size from 0.9 to 5.6 cm in diameter. Mean operating time was 293 ± 50.2 minutes, with an average duration of pneumoperitoneum of 216 ± 27 minutes. Intraoperative blood loss was negligible. No tumor spillages occurred. Postoperative pathology revealed negative margins in all resected specimens. One case of urine leak occurred postoperatively, which resolved spontaneously. Renal function was preserved in all children. At a mean follow up of 11.5 months, all patients have been recurrence free.

CONCLUSION

The herein presented strategy allows for safe nephron-sparing resection of selected WT with acceptable morbidity, good short-term disease-free survival, and potentially better cosmesis and recovery than traditional open surgery. This preliminary experience suggests that minimally invasive options for NSS in children merit further evaluation.

Minimally invasive surgery in management of renal tumours in children

Minimally invasive surgery (MIS) in the management of malignant and benign renal tumours in children is gradually becoming more common. Experience is limited and restricted to case reports, retrospective chart reviews and a few cohort studies. There are currently no randomized controlled trials or controlled clinical trials comparing the laparoscopic and open surgical approach for the management of renal tumours in children. MIS may offer the same oncologic outcome in malignant renal tumours whilst providing the advantages associated with MIS in correctly selected cases. The technique for tumour resection has been shown to be feasible in regards to the recommended oncologic principles, although lymph node sampling can be inadequate in some cases. Preliminary reports do not show an increased risk of tumour rupture or inferior oncologic outcomes after MIS. However, the sample size remains small and duration of follow-up inadequate to draw any firm conclusions. Implementation of MIS is lacking in the protocols of the major study groups, and standardized recommendations for the indications and contra-indications remain undefined. The objective of this article is to present a review of the literature on the role of MIS in the management of renal tumours in children, with the main focus on Wilms' tumour (WT). Further studies on MIS in renal tumours are required to evaluate the incidence of oncological complications such as complete tumour resection and intra-operative tumour spillage. A long-term follow-up of patients managed by MIS is essential to compare recurrence rates and overall survival rates.

Wilms tumor: "State-of-the-art" update, 2016

Despite an impressive increase in survival rate over the past decades, there is still a need to improve the survival of specific subgroups of Wilms tumor (anaplastic, metastatic, and bilateral) and to decrease the late effects of treatment in terms of renal function and heart toxicity. We aim to explore new areas of improvement, from diagnosis to treatment: in the field of radiology the increased use of MRI and exploration of its diffusion-weighted imaging capabilities to predict WT histology at diagnosis and for preoperative assessment; in biology the emergence of new biomarkers that could be integrated into the decision-making process; and surgical techniques with more accurate indication of nephron-sparing surgery that is no longer reserved for bilateral WT and the minimally invasive approach. The long-term outcome of patients with WT should thus be a strong indicator of the improvement in adapting and personalizing the treatment to each individual.

[Surgical concepts in the treatment of Wilms tumor: An update]

BACKGROUND

Treatment results of Wilms tumors have been impressively improved over the past 50 years resulting in a stage-independent overall survival of greater than 90%. However, unsatisfying treatment results still remain in children with high-risk tumors and tumor relapses.

MATERIALS AND METHODS

This review highlights the current concepts of Wilms tumor surgery as a cornerstone of the treatment strategy for this malignancy. A selective literature review focusing on the past 5 years served as the basis for this article.

RESULTS

Nephron-sparing surgery is associated with an analogue outcome compared to tumor nephrectomy in unilateral Wilms tumors. The surgical panel of the International Society of Pediatric Oncology (SIOP) group has recently introduced a novel nomenclature for organ-preserving resection procedures in order to facilitate a prospective comparison of data. The minimally invasive approach represents an alternative technique with adequate outcome. In bilateral disease, nephron-sparing procedures are gold standard. Complete resection of lung and liver metastases has a significant impact on patients' survival.

CONCLUSIONS

Surgical guidelines for nephron-sparing surgery and minimally invasive tumor nephrectomy need to be established and implemented within newly formulated treatment protocols of the different national and international treatment trials. Risk stratification of patients needs to be more individualized with the aim of reducing late effects while at least maintaining the same survival rates. The unsatisfying treatment results of tumor relapses-associated with low patient numbers within the different trials-emphasize the need for international collaboration.

Laparoscopic Nephron-sparing Surgery for Metanephric Adenoma in Children: A Report of 2 Cases

Metanephric adenoma (MA) is an epithelial benign tumor of the kidney and very rare in children. Here we present 2 cases of MA treated by laparoscopic nephron-sparing surgery in children. To the best of our knowledge, we report the first cases of laparoscopic nephron-sparing surgery for MA in children.

The role of minimally invasive surgery in pediatric solid tumors

During recent years, minimally invasive surgery (MIS) has become the standard approach for various operations in infants and children. MIS in pediatric thoracic and abdominal tumors is a controversial approach in the surgical management of childhood cancer. Meanwhile, more and more oncological biopsies and resections are being performed laparoscopically or thoracoscopically. Despite its increasing role in pediatric tumor surgery, the different national and international multicenter trial groups have not yet implemented MIS within guidelines and recommendations in most of the current treatment protocols. An increasing number of retrospective reports describes a potential role of MIS in the management of different pediatric oncological entities. Over the time, there has been a diverse development of this approach with regard to the different neoplasms. Nevertheless, there is a lack of prospective randomized trails assessing MIS. This still represents a requirement for evidence-based medicine and judging the advantages and disadvantages of this approach. The purpose of this state-of-the-art article is to review the current literature to describe the application of MIS in pediatric solid tumors.

Minimally invasive nephrectomy for Wilms tumors in children - data from SIOP 2001

PURPOSE

To analyse the surgical and oncological outcome of minimally invasive surgery (MIS) for tumor nephrectomy in Wilms tumor (WT) patients.

METHODS

WT patients from the SIOP 2001 trial, undergoing MIS for tumor nephrectomy were analyzed with regard to demographic characterization, surgical specifications, complications, and outcome.

RESULTS

There were 24 children matching the inclusion criteria. Median age at operation was 40.35 months (14.3-65.4). All patients received preoperative chemotherapy. Median tumor volume was 177.5 ml at diagnosis (46.5-958) and 73.0 ml at surgery (3.8-776). There was one surgical complication (splenic injury), no intraoperative tumor rupture occurred. Abdominal stage was I in 14, II in 7, and III in 3 patients. Adequate lymph node sampling was performed in only 2 patients. One local relapse occurred. Event-free survival was 23/24, overall survival was 24/24, median follow up was 47 months (2-114).

CONCLUSIONS

We present the largest series so far of minimally invasive nephrectomies for nephroblastoma based on a multinational trial. Treatment results were comparable to those of open surgery; however, experience of operating surgeons was generally high. Discipline of lymph node sampling was inadequate. Based on this analysis a prospective study on MIS in nephroblastoma is planned by the SIOP Renal Tumor Study Group.