Current management of symptomatic vesicoureteral reflux in pediatric kidney transplantation-A European survey among surgical transplant professionals

BACKGROUND

Vesicoureteral reflux (VUR) is common in children and adolescents undergoing kidney transplantation (KTx) and may adversely affect allograft kidney function.

METHODS

To explore the current management of symptomatic native and allograft VUR in pediatric KTx recipients, an online survey was distributed to European surgical transplant professionals.

RESULTS

Surgeons from 40 pediatric KTx centers in 18 countries participated in this survey. Symptomatic native kidney VUR was treated before or during KTx by 68% of the centers (all/selected patients: 33%/67%; before/during KTx: 89%/11%), with a preference for endoscopic treatment (59%). At KTx, 90% favored an anti-reflux ureteral reimplantation procedure (extravesical/transvesical approach: 92%/8%; preferred extravesical technique: Lich-Gregoir [85%]). Management strategies for symptomatic allograft VUR included surgical repair (90%), continuous antibiotic prophylaxis (51%), bladder training (49%), or noninterventional surveillance (21%). Redo ureteral implantation and endoscopic intervention for allograft VUR were equally reported (51%/49%).

CONCLUSIONS

This survey shows uniformity in some surgical aspects of the pediatric KTx procedure. However, with regard to VUR, there is a significant variation in practice patterns that need to be addressed by future well-designed and prospective studies. In this way, more robust data could be translated into consensus guidelines for a more standardized and evidence-based management of this common condition in pediatric KTx.

Determination of tissue tracer transit of Technetium-99m-mercaptoacetyltriglycine diuretic renography in infants with suspected ureteropelvic junction obstruction - A multicenter prospective observational study

INTRODUCTION

There is an ongoing controversy regarding management of ureteropelvic junction obstruction in infants, with a shift towards a non-operative approach. However, precise predictors of outcome are lacking. Recent studies postulated a high prognostic value of Technetium-99m-mercaptoacetyltriglycine tissue tracer transit with regard to the development of an impaired differential renal function and its potential improvement following pyeloplasty.

OBJECTIVE

To evaluate the prognostic value of Technetium-99m-mercaptoacetyltriglycine tissue tracer transit for the occurrence of changes in differential renal function in infants with suspected unilateral ureteropelvic junction obstruction in a prospective observational multicenter study.

STUDY DESIGN

Infants below 3 months of age with a unilateral isolated hydronephrosis ≥ grade 3 received ultrasound and Technetium-99m-mercaptoacetyltriglycine diuretic renography at two different time points (timepoint 1 and timepoint 2). Data were analyzed at local centers and at the study center and were collected in an internet-based database system. Tissue tracer transit was determined for each diuretic renography, inter-observer variation for tissue tracer transit and standard parameters for judgement of differential renal function development were assessed.

RESULTS

Thirty-seven patients were analyzed. Median age was 11 weeks (7-15) at timepoint 1 and 26 weeks (19-33) at timepoint 2. A delayed tissue tracer transit at timepoint 1 was not associated with deterioration of differential renal function at timepoint 2 in both, locally (10/37 cases) and centrally (4/37) analyzed cases. However, sensitivity and specificity were poor. The intraclass correlation coefficient comparing local and central findings of tissue tracer transit and renal drainage demonstrated poor or fair agreement. Analysis of standard parameters for differential renal function development revealed a prognostic value only for the dichotomized anteroposterior renal pelvic diameter (APD, p = 0.03, 95%-CI 1.2-22.2).

DISCUSSION

Regarding the primary endpoint of our study, we could not confirm the hypothesis that delayed tissue tracer transit reliably predicts a subsequent decline in differential renal function in the cohort of patients studied. Whether the low age of the patients, technical problems in the correct assessment of tissue tracer transit by the investigator in early infancy, the study design, or the parameter itself played a role is debated.

CONCLUSION

In the presented setting tissue tracer transit was not useful as a predictive parameter for deterioration of differential renal function in infants with suspected unilateral ureteropelvic junction obstruction. Sensitivity and specificity of tissue tracer transit were not sufficient for risk stratification. Improved utility of tissue tracer transit as a marker might be achieved using a different study setting.

Diagnostic and therapeutic management of vesico-ureteral reflux in pediatric kidney transplantation-Results of an online survey on behalf of the European Society for Paediatric Nephrology

BACKGROUND

Vesico-ureteral reflux (VUR) is considered to be a risk factor for recurrent febrile urinary tract infections and impaired renal transplant survival.

METHODS

An online survey supported by the European Society for Paediatric Nephrology was designed to evaluate current management strategies of VUR in native and transplanted kidneys of recipients aged <18 years.

RESULTS

Seventy-three pediatric transplant centers from 32 countries contributed to the survey. All centers performed urological evaluation prior to pediatric kidney transplantation (KTx) with subsequent interdisciplinary discussion. Screening for VUR in native kidneys (30% in all, 70% in selected patients) led to surgical intervention in 78% (11% in all, 89% in selected patients) with a decided preference of endoscopic intervention over ureterocystoneostomy. Following KTx, continuous antibiotic prophylaxis was applied in 65% of the patients and screening for allograft VUR performed in 93% of selected patients. The main management strategies of symptomatic allograft VUR were continuous antibiotic prophylaxis (83%) and surgical treatment (74%) (endoscopic intervention 55%, redo ureterocystoneostomy 26%).

CONCLUSIONS

This survey demonstrates the high variability in the management of VUR in pediatric KTx recipients, points to knowledge gaps, and might serve as a starting point for improving the care for patients with VUR in native and transplanted kidneys.

Laparoscopically Guided External Transanastomotic Stenting in Dismembered Pyeloplasty: A Safe Technique

OBJECTIVE

To describe a technique for insertion of external transanastomotic stents during laparoscopic dismembered pyeloplasty in children of all age-groups. To analyze stent-associated complications and changes in differential renal function (DRF).

PATIENTS AND METHODS

A retrospective study was performed of all patients up to 18 years of age undergoing laparoscopic pyeloplasty at our institution between March 2004 and December 2013. We analyzed patients in whom an external transanastomotic stent was placed using a specially constructed semicircular spear. Medical records were reviewed for stent-associated complications such as bleeding, stent dislocation, stent obstruction, and urinary tract infection. Additionally required secondary surgical procedures and changes in DRF were assessed.

RESULTS

A total of 150 patients (155 renal units [RU]) were included in the study, with a median patient age of 22 months (range, 1-214). Stents were removed after a median time of 7 days (range, 3-21). Stent-associated complications were observed in a total of 11 patients (12 RU), consisting of stent dislocations (6 RU), stent obstructions (3 RU), and persistent percutaneous leakage along the stent (1 RU) or after stent removal (2 RU). Stent-associated complications required a secondary surgical procedure in 4 RU. Neither significant blood loss nor urinary tract infection was associated with external transanastomotic stent placement. DRF did not change significantly after the procedure.

CONCLUSION

External transanastomotic stenting during laparoscopic dismembered pyeloplasty using a specially constructed semicircular spear is a safe technique associated with a low complication rate and only rarely requires secondary surgical procedures for stent-related complications. This technique makes an additional anesthesia for stent removal unnecessary, as it is required for internal urinary diversion.

Single-stage surgical approach in complicated paediatric ureteral duplication: surgical and functional outcome

PURPOSE

Surgical approach to children with complicated ureteral duplication is discussed controversially. Our aim was to determine the outcome of children with complicated renal duplication undergoing a single-stage surgical approach with laparoscopic partial nephrectomy and open bladder reconstruction.

METHODS

Data of patients from 2004 to 2008 were investigated retrospectively. Outcome was analyzed in terms of postoperative course, renal function, urinary tract infection and functional voiding.

RESULTS

Thirteen patients were treated with laparoscopic partial nephrectomy and reconstruction of the lower urinary tract in a single-stage approach. Median age at operation was 15 months (2-63 m). One girl had a renal triplication. 7/13 patients presented with an ectopic ureterocele, two with an ectopic ureter, severe vesicoureteral reflux occurred in 6 patients. All patients had non-functioning renal moieties. Mean operative time was 239 min (129-309; SD 50). One re-operation was necessary 4 years after primary surgery due to a pole remnant. All patients had uneventful recoveries without evidence of recurrent UTI. Postoperative 99mTc-MAG3 scans showed no significant reduction of partial renal function (p = 0.4), and no signs of obstruction (p = 0.188). During a median follow-up of 60 months (49-86), dysfunctional voiding occurred in one patient.

CONCLUSIONS

In children with complicated ureteral duplication a definitive single-stage procedure is feasible and shows excellent functional results.

Weight-adapted surgical approach for laparoendoscopic single-site surgery in pediatric patients using low-cost reusable instrumentation: a prospective analysis

OBJECTIVES

Laparoendoscopic single-site surgery (LESS) in pediatric patients has emerged as a viable alternative to standard laparoscopy. The aim of our investigation was to assess different surgical approaches for LESS, stratifying by weight.

SUBJECTS AND METHODS

From March 2010 to April 2012 LESS was performed in 42 children. Children weighing below 10 kg underwent LESS through an umbilical incision using two 3-mm trocars and one 5-mm trocar. Patients above 10 kg were operated on using a metal multiuse single-site single port (X-Cone; Karl Storz Endoskope, Tuttlingen, Germany). Conventional straight laparoscopic instruments were used in all cases.

RESULTS

Mean age at operation was 100 months (range, 0.25-207 months), and mean weight was 27 kg (range, 3.1-82 kg). Median operating time was 74 minutes (range, 36-300 minutes). Eighteen children underwent LESS using two 3-mm trocars and one 5-mm trocar; 1 case required two 5-mm trocars and one 10-mm trocar. Twenty-three patients were operated on with the multiuse device. All operations were carried out safely in a standard laparoscopic transperitoneal technique with full achievement of the surgical target. In none of the patients was an intraoperative complication noticed. Postoperatively two complications were noted, which resolved spontaneously.

CONCLUSIONS

LESS for pediatric patients can be done safely and efficiently with even less trauma than in conventional laparoscopy irrespective of age and weight. However, different surgical approaches have to be considered as disposable single-site ports are not available for infants and small children. To decrease operative expenses, conventional multiuse trocars and a multiuse single-site port were used with conventional laparoscopic instruments.

Acute traumatic posterior elbow dislocation in children

Traumatic posterior dislocation of the elbow is often associated with significant morbidity and incomplete recovery. The aim of this study was to retrospectively analyse the outcome of 33 children (median age 10.8 years). Patients underwent reduction and assessment of stability under general anaesthesia. Pure dislocations (n=10) were immobilized, whereas unstable fractures (n=23) were stabilized. Refixation of ligaments was performed if stability was not achieved by fracture stabilization alone. Immobilization was continued for 26 (pure dislocations) or 35 days (associated injuries), respectively. Results were excellent (n=9) or good (n=1) after pure dislocation. Results were excellent (n=15), good (n=7) or poor (n=1) in children with associated injuries. Accurate diagnosis, concentric stable reduction of the elbow as well as stable osteosynthesis of displaced fractures are associated with good results in children with acute posterior elbow dislocations.

Perioperative outcome of patients with esophageal atresia and tracheo-esophageal fistula undergoing open versus thoracoscopic surgery

INTRODUCTION

Thoracoscopic approach for repair of esophageal atresia (EA) and tracheo-esophageal fistula (TEF) has become a standard procedure in many pediatric surgical centers. Thoracoscopic surgery in a newborn is demanding from both the surgeon and the patient. The potential benefits for the newborn are still discussed by neonatologists, pediatric intensive care physicians, and also parents. The aim of our investigation was to clearly define perioperative outcome and complication rates in children undergoing thoracoscopic versus open surgery for EA and TEF repair.

PATIENTS AND METHODS

We reviewed the records of 68 newborns undergoing surgery for EA and TEF between March 2002 and February 2010. Patient data of open versus thoracoscopic approach were compared regarding operating time, intraoperative as well as postoperative pCO(2)max values, postoperative ventilation time, and complications. Specific patient data are reported with the median and range. Data analysis was done with the JMP(®) 7.0.2 statistical software (SAS Institute, Cary, NC).

RESULTS

For the 68 patients, the mean gestational age was 35 weeks (28-41), the median birth weight was 2720 g (1500-3510 g) in the thoracoscopic group and 2090 g (780-3340 g) in the open group. There were 36 girls and 32 boys. Thirty-two children had associated anomalies. Twenty-five children were undergoing a thoracoscopic procedure. In 8 cases, the operation was converted to open thoracotomy. Another 32 children received a thoracotomy. In 11 newborns, a cervical esophagostomy was performed because of long-gap EA and these patients were excluded from the study. Operating time was 141 minutes (77-201 minutes) in the thoracoscopic group and 106 minutes (48-264 minutes) in the thoracotomy group, with significant difference (P=.014). Values of pCO(2)max during operation were 62 mm Hg (34-101 mm Hg) in the thoracoscopic group and 48 mm Hg (28-89 mm Hg) in the open group, with significant difference (P=.014). Postoperative ventilation time was 3 days (1-51 days) in all groups, with no significant difference (P=.79). Early complications were noticed in 9 children undergoing thoracoscopy and in 8 patients of the thoracotomy group, again with no significant difference (P>.05).

CONCLUSION

Thoracoscopic repair of EA with TEF is justified because of a comparable perioperative outcome to open surgery, competitive operating times, decreased trauma to the thoracic cavity, and improved cosmesis despite skeptical considerations. Complication rates are not higher than in children operated on through a thoracotomy. However, a learning curve has to be taken into account and large experience in minimal invasive surgery is mandatory for this procedure. Larger series have to be expected for a more objective evaluation of perioperative as well as long-term outcomes. To our opinion, the thoracoscopic approach appears to be favorable and could be a future standard.

Functional outcome after laparoscopic dismembered pyeloplasty in children

OBJECTIVE

Laparoscopic or retroperitoneoscopic pyeloplasty for ureteropelvic junction obstruction in children has become a routine procedure. The aim of this study was to evaluate functional outcome for patients who had undergone a laparoscopic dismembered pyeloplasty.

PATIENTS AND METHODS

Seventy children underwent a laparoscopic dismembered pyeloplasty. Median follow up was 24 months (1-48). We reviewed differential renal function (DRF) and tracer clearance with diuretic renography before as well as 3 and 12 months after operation. Ultrasound was used to determine the grade of hydronephrosis pre- and postoperatively.

RESULTS

Median age at operation was 20 months (1-178). Median operating time was 140 min (95-220). Mean DRF could be preserved with no significant difference (P>0.05). All patients showed a significant improvement in tracer clearance on diuretic renography postoperatively (P<0.0001). Ultrasound examinations postoperatively showed a diminished grade of hydronephrosis without significance (P=0.657).

CONCLUSION

In terms of preservation of DRF the laparoscopic approach is as effective as open surgery. Tracer clearance is significantly improving. Operating times for laparoscopic pyeloplasty are competitive. We conclude that laparoscopic pyeloplasty requires extensive experience in laparoscopic pediatric urology but might replace the open surgical procedure as gold standard in the operative treatment of ureteropelvic junction obstruction.

Laparoscopic surgery on upper urinary tract in children younger than 1 year: technical aspects and functional outcome

PURPOSE

Minimally invasive procedures are increasingly important in pediatric urology. However, experience is still limited with minimally invasive operations on the upper urinary tract in infants. We analyzed 3 minimally invasive procedures (pyeloplasty, heminephroureterectomy and nephrectomy) in children younger than 1 year.

MATERIALS AND METHODS

We analyzed 67 children (mean +/- SD age 5.1 +/- 2.9 months) undergoing minimally invasive pyeloplasty in 26 patients (group 1), heminephroureterectomy in 18 (group 2) or nephrectomy in 23 (group 3) with regard to technical aspects, surgical outcome and complications. Preoperative and postoperative ultrasound and mercaptoacetyltriglycine renal scan were statistically evaluated in groups 1 and 2.

RESULTS

Mean +/- SD patient weight was 6.4 +/- 1.8 kg and mean +/- SD operative time was 113.2 +/- 41.6 minutes. Conversion to open surgery was necessary in 1 pyeloplasty. One complication (missed intraoperative bowel perforation) occurred. No blood transfusion was required in any child. After pyeloplasty there were improved tracer clearances (mercaptoacetyltriglycine scan) and improved morphologies of the pyelon (ultrasound) in all patients. In groups 1 and 2 there was no statistical difference between preoperative and postoperative partial function of the affected kidney. Mean +/- SD followup was 32.5 +/- 19.8 months.

CONCLUSIONS

Minimally invasive procedures on the upper urinary tract in children younger than 1 year are technically challenging, and require expertise of the surgeon and the entire team. Given these assumptions, such procedures can be safely performed with excellent functional outcomes.

Impact of pedicle clamping in pediatric liver resection

BACKGROUND

Vascular clamping techniques are commonly used but so far the impact on pediatric liver surgery has not been investigated. The purpose of this study was to analyze pedicle clamping during pediatric liver resection in terms of hepato-cellular injury and blood loss.

METHODS

Sixty-seven children undergoing liver resection were analyzed retrospectively. Vascular clamping was used in 28 cases (PC group), in 39 the resection was performed without clamping (NPC group). Major hepatectomies (resection of more than three segments) were carried out in 88%, minor hepatectomies (resection of three and less segments) in 12% of patients. Twenty-six children underwent extended liver resection. Patient data, liver function tests (LFTs) and blood loss were analyzed statistically.

RESULTS

There were no significant differences in patient preoperative and postoperative data and LFTs between the groups. Within the NPC group the amount of administered fresh frozen plasma (FFP) in total and per kilogram (FFP/kg) was significantly higher (p=0.023 and 0.028) than in the PC group. For patients with extended liver resection, operation times were significantly longer (p=0.016) in the group without vascular clamping (NPCext). In the NPCext group significantly more children required packed red cells, FFP and FFP/kg. LFTs showed no significant differences in all children regardless of vascular clamping.

CONCLUSIONS

For children undergoing liver resection, vascular clamping offers a blood saving surgical technique. Postoperative LFTs were not statistically different, regardless of vascular clamping. Pedicle clamping proved to be a safe method, not associated with an increase in perioperative complications.

Surgical implications for liver metastases in nephroblastoma--data from the SIOP/GPOH study

BACKGROUND

In children with Wilms' tumor, the 5-year overall survival rate is over 90% in the SIOP/GPOH study group. However, a small group of patients have tumor lesions in the liver at the time of initial diagnosis or as a recurrence. This group seems to have a worse prognosis in terms of survival. The treatment and outcome of patients with a hepatic recurrence were analyzed compared to previously published data of patients with primary hepatic metastases.

PATIENTS AND METHODS

We reviewed the records of 45 out of 1365 patients enrolled in the SIOP 93-01/GPOH study and the SIOP 2001/GPOH study between April 1, 1994 and September 30, 2004. Median age at diagnosis was 6.49 years (1.37-34.16 years) in 29 patients who were initially presented with hepatic metastases (group I) with 9 males and 20 females. In 16 children who had a recurrence of a nephroblastoma in the liver (group II), median age at diagnosis was 4.62 years (1.84-31.08 years) with 9 males and 7 females.

RESULTS

In group I out of 29 patients, 11 died at a median of 13.07 months. Overall survival in group I was 62.58%. In group II, 9 patients died at a median 52 months. Overall survival in group II was 54.7%.

CONCLUSION

This report suggests that when complicated by metastases of the liver, Wilms' tumor has a less favorable outcome. Chemotherapy and radiotherapy play a definitive role in the treatment of these children. The importance of complete resection of hepatic lesions in both groups should be emphasized.

Treatment of cystic nephroma and cystic partially differentiated nephroblastoma--a report from the SIOP/GPOH study group

PURPOSE

Cystic partially differentiated nephroblastoma is a rare variant of Wilms tumor, and might be confused with cystic nephroma. Definitive diagnosis can only be made by histological examination. Therefore, initiation of therapy, either primary nephrectomy or preoperative chemotherapy, might create a dilemma when radiological diagnosis is doubtful.

MATERIALS AND METHODS

To define treatment strategies for these entities, we reviewed the records of 1,245 patients enrolled in SIOP (International Society of Pediatric Oncology) trials 93-01 and 2001 GPOH (German Society of Pediatric Oncology and Hematology) between July 1993 and August 2004. Data were collected retrospectively. Therapy, outcome and preoperative management were evaluated. To confirm diagnosis of cystic nephroma/partially differentiated nephroblastoma, all patients underwent review by the Reference Pathology Center of SIOP/GPOH.

RESULTS

A total of 14 patients with diagnoses of cystic nephroma (7) and cystic partially differentiated nephroblastoma (7) were identified. Median patient age at diagnosis was 1 year (0.46 to 3). Two patients received preoperative chemotherapy. Primary nephrectomy was performed in 12 patients. Two patients underwent partial nephrectomy. In 1 child postoperative chemotherapy was administered. None of the patients had progression of disease or recurrence. Overall survival was 100%. Median followup was 2.41 years (0.3 to 9).

CONCLUSIONS

In cystic renal tumors radiological findings should always be reviewed by the reference radiologist of the treatment protocol study group. Irrespective of the chosen therapy, outcome of cystic nephroma and cystic partially differentiated nephroblastoma is favorable. Even in large international trials the number of patients with cystic nephroma or cystic partially differentiated nephroblastoma is too small for statistical analysis.

Primary hepatic metastases in nephroblastoma--a report of the SIOP/GPOH Study

PURPOSE

Remarkable progress could be achieved in the treatment of nephroblastoma within the last decades. In all children with Wilms' tumor, 5-year overall survival rate reaches more than 90% in the SIOP/GPOH Study Group. Despite this fact, there is a small group of patients who have tumor lesions in the liver primarily representing a challenge in treatment. Data of this group are analyzed.

METHODS

To define survival and success of treatment in this group of patients, we reviewed the records of 29 of 1365 patients enrolled in the SIOP 93-01/GPOH Study and the SIOP 2001/GPOH Study between April 1, 1994, and September 30, 2004.

RESULTS

Median age at diagnosis was 10.61 years (range, 0.19-34.16 years). All patients but two underwent nephrectomy. Liver metastases were operated in 11 children at time of nephrectomy, in 4 patients secondarily, whereas in 11 patients, liver lesions were treated alone with chemotherapy and radiotherapy, respectively. In 3 children, no treatment could be initiated. Sixteen patients received radiotherapy additionally. Median follow-up was 64 months (range, 3-157 months). Eleven patients died in the course at a median of 13.07 months (range, 0.25-42 months) after initial diagnosis. These included 7 patients who never had surgery for their liver lesions and 4 patients who had incomplete and/or atypical resections of their metastatic liver lesions. All patients who underwent complete resection of hepatic metastases (n = 9) survived. Eight children survived with a nonsurgical treatment. Overall survival was below 60% in the whole group up to now.

CONCLUSIONS

Liver metastases are much less frequent than metastases to other sites. Our report suggests that Wilms' tumor complicated by metastases of the liver primarily has a less favorable outcome. Chemotherapy and radiotherapy play an important role in treatment. Radical surgery for nephrectomy as well as surgery of liver lesions cannot be overemphasized to prevent local and distant recurrence.

Surgery of cavoatrial tumor thrombus in nephroblastoma: a report of the SIOP/GPOH study

BACKGROUND

Resection of a Wilms tumor extending through the inferior vena cava into the right atrium represents a challenge to the pediatric surgeon. Exact preoperative diagnosis is essential to identify the tumor and its intravascular extension. To achieve a complete excision of the tumor cardiopulmonary bypass and hypothermia may be required. The feasibility of a complete resection is important as it guides subsequent therapy such as chemotherapy and radiation.

PROCEDURE

In order to define these issues, we reviewed the records of 33 of 1,151. Patients enrolled in the SIOP 93-01/GPOH Study and the SIOP 2001/GPOH Study who had a tumor thrombus into the inferior vena cava and into the right atrium.

RESULTS

The median age at diagnosis was 3.73 years. Twenty-four patients had a tumor thrombus into the inferior vena cava, in nine patients the thrombus reached into the right atrium. All patients were operated on; cardiopulmonary bypass was used in nine patients. There were no deaths intraoperatively. Twenty-nine children are still alive; four patients died, one patient due to aspiration and failed resuscitation, two patients died from a recurrent tumor, and one child due to an unresectable primary tumor.

CONCLUSION

Our report suggests that Wilms tumor extending to the inferior vena cava and the right atrium is technical challenging, but with adequate preoperative diagnosis and a multidisciplinary surgical approach including cardiopulmonary bypass and hypothermia, the prognosis is favorable.