ESPU Meeting on Friday 21, April 2023, 17:00 - 18:05
17:00 - 17:03
S20-1 (OP)
Liam Sean Lloyd MCCARTHY 1, Hannah RHODES 2, Saifa CHOUDHURY 3 and Suzanne STEPHENS 3
1) Birmingham Children's Hospital, Department of Urology, Birmingham, UNITED KINGDOM - 2) Birmingham Children's Hospital, Paediatric Urology, Birmingham, UNITED KINGDOM - 3) Birmingham Children's Hospital, Paediatric Nephrology, Birmingham, UNITED KINGDOM
PURPOSE
Haemodialyis may be performed via percutaneous central lines (Haemocatheters (HC)) or via Arteriovenous fistulae (AVF), typically radio-cephalic in children.
Haemocatheters typically work immediately, but can be associated with line infection, superior vena cava obstruction (SVC), thrombosis and embolism, breakage, and the need for recurrent line insertion. AVFs only mature in 70% and take 6 weeks to do so.
This study aims to compare the survival of the different haemodialysis routes and their vascular complication rates.
MATERIAL AND METHODS
Patients were retrospectively identified using a departmental database, data collected for: date of insertion of access, survival (days) of access route. Complications including Central venous obstruction and access obstruction were recorded.
Data given as Number (%), Median (IQR). Survival analysed using Kaplan-Meier and log-rank test, other data Fisher-Exact test and Mann-Whitney U-test as appropriate, P<0.05 taken as significant.
RESULTS
23 AVFs were performed in 22 patients, compared to 43 HC in 21 patients. Age range AVFs 13.8(12.0-14.0)yrs vs HCs 9.2(4.1-13.4), P=0.01. AVFs matured 17/23(74%), once matured, 73% still working at 5.4 yrs vs HCs median survival 293 days, log rank P=0.029. Central venous obstruction(3) and fibrin sheath obstruction(2) occurred in 5/21(24%) of patients with HCs vs no AVF patients, P=0.048.
CONCLUSIONS
AVFs matured in 74% of cases, and remained functional up to 5 years post-op, and were not associated with central venous obstruction. HCs worked immediately but failed progressively thereafter with significant risk of central venous obstruction. AVFs should be considered as the first line route for dialysis access in older children.
17:03 - 17:06
S20-2 (OP)
Loes OOMEN 1, Huib DE JONG 2, Antonia BOUTS 3, Mandy KEIJZER-VEEN 4, Elisabeth CORNELISSEN 5, Liesbeth DE WALL 1, Wout FEITZ 1 and Charlotte BOOTSMA-ROBROEKS 5
1) Radboudumc Amalia Children's Hospital, Urology, division of Pediatric Urology, Nijmegen, NETHERLANDS - 2) Erasmus MC-Sophia Children's Hospital, Pediatric Nephrology, Rotterdam, NETHERLANDS - 3) Amsterdam University Medical Center, Emma Children's Hospital, Pediatric Nephrology, Amsterdam, NETHERLANDS - 4) Wilhelmina Children's Hospital, University Medical Center Utrecht, Pediatric Nephrology, Utrecht, NETHERLANDS - 5) Radboudumc Amalia Children's Hospital, Pediatric Nephrology, Nijmegen, NETHERLANDS
PURPOSE
A prediction model for graft survival based on donor and recipient characteristics could help clinical decision making and optimize outcome. The aim of this study was to develop a risk assessment tool for graft loss based on essential pre-transplantation parameters.
MATERIAL AND METHODS
The data originated from the national Dutch registry (NOTR). A multivariable binary logistic model was used to predict hazard of graft loss, corrected for era of transplantation and course of time after transplantation. Subsequently, a prediction score was calculated based on the β-coefficients. For internal validation a derivation (80%) and validation cohort (20%) were defined. Model performance was assessed with area under the curve of the receiver operating characteristics curve, Hosmer-Lemeshow test and calibration plots.
RESULTS
The prediction model was based on 7252 observations after 1425 transplantations between 1966-2021. Ten years graft survival was 42% for transplantations before 1990 and improved to a current 92%. Over time, significantly more living and pre-emptive transplantations were performed and overall donor age increased (p<0.05). Other variables incorporated in the model were recipient age, re-transplantations, number of HLA mismatches and cause of kidney failure. The predictive capacity of this model had AUC scores of 0.85, 0.83, 0.80 and 0.75 after 1, 5, 10 and 20 years respectively (p<0.01). Calibration plots showed excellent fit.
CONCLUSIONS
This pediatric pre-transplantation risk assessment tool was highly predictive for graft survival within the Netherlands. This model could support decision making regarding donor selection in order to optimize graft outcome.
17:06 - 17:09
S20-3 (OP)
Jin Kyu (Justin) KIM, Priyank YADAV, Michael CHUA, Mandy RICKARD and Armando LORENZO
The Hospital for Sick Children, Division of Urology, Toronto, CANADA
PURPOSE
Delayed graft function (DGF), often defined as need for post-operative dialysis during the first week after kidney transplantation, contributes to both patient outcomes and economic costs. Several attempts have been made to predict DGF in the adult population. However, there remains limited information on predicting DGF in children. Therefore, we aim to create a machine learning model that predicts DGF outcomes in children who undergo kidney transplantation.
MATERIAL AND METHODS
An institutional database of children and adolescents who underwent kidney transplantation was examined. Python 3.9.13 was used for model development. The data were built using an 80:20 train-test split. To avoid model bias for lack of DGF outcome, Synthetic Minority Oversampling Technique for Nominal and Continuous (SMOTE-NC) was employed, effectively increasing the number of cases of DGF in the dataset in a balanced manner. Extreme Gradient Boosting (XG Boost) was ultimately employed to build our model. Gridsearch was performed to optimize model parameters.
RESULTS
A total of 409 patients were included in our analysis. Forty patients had DGF (9.7%). Following SMOTE-NC, the training data generated 295 patients in each group. After training with XG Boost model with Gridsearch parameters, the model had a 5-fold cross-validation accuracy of 93.1% and a receiver operating characteristics (ROC) area under the curve of 91.7%. On evaluation of the confusion matrix, the model had an excellent specificity of 96.0% (71/74) but a rather modest sensitivity of 37.5% (3/8). The deployed model can be found in: https://kimjk4-dgfprediction-app-omaz4b.streamlitapp.com
CONCLUSIONS
The generated model had very high negative predictive value, allowing us to identify patients with high risk of DGF, providing an opportunity for closer monitoring. This novel model is the first attempt at predicting DGF in children undergoing kidney transplantation and holds promise for further development and improvement with additional variables and patient numbers.
17:09 - 17:12
S20-4 (OP)
Rosa M ROMERO 1, Gorka GOMEZ-CIRIZA 2, Eduardo LEON 3, Julia FIJO 4, Sebastian ROLDAN 1, Ana SANCHEZ 4, Francisco DE LA CERDA 4, Rocio VIZCAINO 1 and Lourdes DELGADO 1
1) Hospital Universitario Virgen del Rocio, Pediatric Urology, Seville, SPAIN - 2) Hospital Universitario Virgen del Rocio, IBIS, Servicio de Diseño Asistido por Computador e Impresión 3D., Sevilla, SPAIN - 3) Hospital Universitario Virgen del Rocio, Urology, Seville, SPAIN - 4) Hospital Universitario Virgen del Rocio, Pediatric Nephrology, Seville, SPAIN
PURPOSE
Our study aims to describe the development of a 3D print model to assist in surgical assessment and decision-making in children with vascular anomalies requiring kidney transplantation.
MATERIAL AND METHODS
Descriptive study of the cohort of patients with vascular anomalies assessed for kidney transplant from 2017 to September 2022. The development process of a 3D print model for surgical planning and simulation is described and compared with radiological assessment.
RESULTS
Eight patients (n=8/100) with vascular anomalies were assessed for kidney transplant (2 males/ 6 females, age range 3,5- 16 years, weight range 9-32,8 kg). Vascular anomalies were IVC thrombosis n= 3, right iliac vein thrombosis n=1, abnormal IVC bifurcation n=1, supramesenteric aortic bifurcation n=2, hypoplastic distal aorta and left iliac artery n=1). All patients had significant comorbidities with pelvic malformations in cases of arterial anomalies.
The 3D model was based on contrast-CT, VirSSPA Software® used to segment areas of interest and resulting 3D mesh processed with MeshMixer® and Cura®. Initial prints (PLA and Polyurethane) were assessed by surgical team, and decisions made on anatomic structures (bone frame, liver and vasculature) and materials (FDM BQ Witbox). Models are case-specific and cross-examined by engineering and surgical team and scored “Great Help” to learn and understand anatomy, planning and potential complications. Five (5/8) patients were transplanted, surgical planning based on the 3D model was maintained with excellent clinical outcomes.
CONCLUSIONS
This 3D print model for assessing and planning kidney transplantation in children with vascular anomalies permits surgical planning and may enhance decision-making and training.
17:26 - 17:29
S20-5 (OP)
Isabel GONZÁLEZ-BARBA 1, Romy GANDER 1, Jose Andrés MOLINO 1, Gloria ROYO 1, Montserrat AGUILERA 1, Montserrat AGUILERA 1, Haider Ali KHAN 1, Gema ARICETA 2, Jesus QUINTERO 3, Manuel LOPEZ 1, Ramón CHARCO 4 and Marino ASENSIO 1
1) Hospital Universitario Vall d'Hebron, Pediatric Surgery, Barcelona, SPAIN - 2) Hospital Universitario Vall d'Hebronp, Pediatric Nephrology, Barcelona, SPAIN - 3) Hospital Universitario Vall d'Hebron, Pediatric Hepatology, Barcelona, SPAIN - 4) Hospital Universitario Vall d'Hebron, General and Digestive Surgery, Barcelona, SPAIN
PURPOSE
Simultaneous liver-kidney transplants (SLKT) are traditionally performed through two separate incisions. The aim of this study is to describe a single access through a modified J-shaped incision.
MATERIAL AND METHODS
A retrospective review of all single-access SLKT was performed. The modified J-shaped incision extends from the xiphoid process to a centimeter above the umbilicus and laterally to the right flank.
RESULTS
Out of 20 SLKT the last 6 (3 females/3 males) were performed using this approach. Mean age and weight was 9.2 and 26.98 kg. Primary diagnosis was: autosomal polycystic kidney disease (ARPKD) (4), primary hyperoxaluria type 1 (1) and gene NEK8 mutation (1). One patient had a history of two previous extraperitoneal kidney transplants.
All grafts were implanted intraperitoneally and on the right side. The common iliac artery was employed in all arterial anastomosis. Both the common iliac vein (4) and external iliac vein (1) were employed for the venous anastomosis. Extravesical ureteral reimplantation was carried out in all but two patients who required an end-to-end anastomosis to the native ureter. There were no intraoperative complications. With a mean follow-up of 18.8 months, there were no urological or wound-associated complications and all allo-grafts are functional.
CONCLUSIONS
SLKT through a modified J-shaped incision provides safe access to both upper and lower right quadrants without compromising surgical exposure and reduces operative time. Older patients with deep-set pelvic bladders may require reimplantation via anastomosis to the native ureter. This approach did not entail any surgical complications.
17:29 - 17:32
S20-6 (OP)
Carla RAMIREZ-AMOROS 1, Maria SAN BASILIO 1, Francisco De Borja NAVA 2, Virginia AMESTY 2, Susana RIVAS 2, Roberto LOBATO 2, Pedro LOPEZ PEREIRA 2 and Maria Jose MARTINEZ URRUTIA 2
1) La Paz University Hospital, Paediatric surgery, Madrid, SPAIN - 2) La Paz University Hospital, Paediatric urology, Madrid, SPAIN
PURPOSE
The use of kidneys from donors under six years of age in pediatric recipients remains controversial. The objective is to establish the influence of donor age on the long-term functionality of the renal graft and its adaptation to the increasing functional requirements of the pediatric patient.
MATERIAL AND METHODS
Retrospective study of outcomes in pediatric recipients transplanted with grafts from donors aged 3-6 years, comparing them with grafts from donors older than 6 years. Among the variables compared are graft survival, renal size, need for antiproteinuric therapy, GFR, incidence of rejection, pyelonephritis, renal failure and surgical complications.
RESULTS
43 transplants were performed with donors aged 3-6 years, and 42 transplants with older donors. Graft survival at five and eight years was 81% and 74% for the younger donor group compared to 98% and 95% for older donors (p<0.05). The mean estimated graft survival was 11.52 and 14.51 years respectively. During follow-up, the younger donor group presented greater renal enlargement and need for antiproteinuric therapy. Older donors had a higher GFR during the first year of follow-up, which then equalized in both groups. There were no significant differences in the incidence of acute or chronic rejection, acute pyelonephritis, acute renal failure or complications.
CONCLUSIONS
Although better graft survival outcomes are obtained with older donors, those from donors aged 3-6 years have proven to be a valid option, able to increase in size according to the recipient's needs and maintain glomerular filtration rates.
17:32 - 17:35
S20-7 (OP)
Priyank YADAV 1, Joana DOS SANTOS 1, Mandy RICKARD 1, Dheidan ALSHAMMARI 1, Adree KHONDKER 1, Juliane RICHTER 1, Jin Kyu KIM 1, Chia Wei TEOH 2, Armando LORENZO 1 and Michael CHUA 1
1) The Hospital for Sick Children, Urology, Toronto, CANADA - 2) The Hospital for Sick Children, Nephrology, Toronto, CANADA
PURPOSE
Doppler ultrasound (DU) is the main imaging modality in the postoperative management of renal transplantation specifically evaluating vascular complications and renal hypoperfusion. The resistive index (RI) and peak systolic velocity (PSV) are two common parameters reported after renal transplantation. Herein, we studied their relationship with acute tubular necrosis (ATN) and rejection to differentiate between these two adverse outcomes.
MATERIAL AND METHODS
We analyzed an institutional database of all children undergoing renal transplantation between years 2000 and 2020, focusing on cases with a single renal artery anastomosis. Patients were divided into 3 groups: ATN, rejection and neither. Between these three groups, RI and PSV on ultrasound done around four different time points were compared: first 24 hours after transplant, three months, six months and 1 year after transplant. Repeated measures ANOVA was performed to look for significant change in RI or PSV over time.
RESULTS
During the study period, 368 patients were identified, of which 289 and 275 had RI and PSV documentation on the first postoperative DU respectively. The mean values of RI and PSV were not different between ATN, rejection and none of these at all four time points. Repeated measures ANOVA revealed that the RI changes over time significantly (p<0.001) for the third group while ATN and rejection are not associated with any significant change. However, the PSV does not change significantly in all 3 groups.
CONCLUSIONS
Postoperative doppler ultrasound within 24 hours, and at 3 months, 6 months and 1 year after renal transplantation in children does not differ between ATN, rejection and none of these. Though RI changes significantly over time for patients without ATN or rejection, it does not reliably differentiate patients with ATN or rejection.
17:35 - 17:38
S20-8 (OP)
Priyank YADAV 1, Mandy RICKARD 1, Dheidan ALSHAMMARI 1, Chia Wei TEOH 2, Adree KHONDKER 1, Juliane RICHTER 1, Jin Kyu KIM 1, Joana DOS SANTOS 1, Michael CHUA 1 and Armando LORENZO 1
1) The Hospital for Sick Children, Urology, Toronto, CANADA - 2) The Hospital for Sick Children, Nephrology, Toronto, CANADA
PURPOSE
To study the natural history of post-renal transplant perinephric fluid collections, and their progression to symptomatic lymphocele.
MATERIAL AND METHODS
We retrospectively reviewed the data of pediatric patients who underwent renal transplantation between 2000 and 2021. Demographics, preoperative medical history, operative details, preoperative and postoperative investigations and ultrasound details were noted for each patient. We divided the patients into two groups: (a) group A that included patients with symptomatic lymphocele and (b) group B that included patients without symptomatic lymphocele. We retrieved the ultrasound findings for these patients at times that were closest to the following mean time points: 1 day, 1 week, 3 week, 6 weeks, 3 months, 6 months and 1 year. Comparisons were made for the resolution times between the two groups using Yates's chi-squared test and size of the collection at different time points using ANOVA test.
RESULTS
Of the 450 patients who underwent renal transplant during the study period, 23 (5.1%) had symptomatic lymphoceles. Median time to symptomatic lymphocele was 29 days (IQR 9,41). 6/23 patients did not require any intervention. They had persistent drain output that decreased gradually resolved spontaneously. In the remaining 17 patients, two required aspiration alone, five required drain placement, six required drain placement and sclerotherapy and four required laparoscopic internal drainage. The median time to ultrasonographic resolution of lymphocele cavity/ perinephric collection was 131 days vs 35 days for the 2 groups (p<0.001). The size of collection was significantly different between the groups at 3 weeks, 6 weeks and 3 months only (p<0.001).
CONCLUSIONS
Majority of post-transplant perinephric collections do not progress to symptomatic lymphoceles; the latter typically present around 4-weeks after renal transplantation. The size of perinephric collection between 3-weeks and 3-months can indicate the possibility of symptomatic lymphocele.
17:52 - 17:55
S20-9 (OP)
Ezel AYDOĞ, Alkan OKTAR, Khaled OBAID, Furkan ÖZSOY, Tarkan SOYGÜR and Berk BURGU
Ankara University School of Medicine, Urology, Ankara, TURKEY
PURPOSE
On pediatric patients with a prior kidney transplant, the surgical management of vesicoureteral reflux (VUR) occurring on the transplanted and native kidneys is still unclear. We pursued to evaluate outcomes of endoscopic treatment modalities performed in our center.
MATERIAL AND METHODS
Retrospectively, data on 97 patients who has undergone endoscopic bulking agent injection for refluxing transplanted kidneys between Jan-2003 and Dec-2018 were collected. Reflux on all patients were diagnosed by VCUG after a febrile UTI episode. All selected patients had G2-4 reflux on transplanted with or without VUR to native kidneys. 65 patients had an accompanying reflux on at least one native kidney, whom also had an endoscopic bulking agent injection concurrent with the transplanted kidney. All patients were followed up for at least 3 years. Statistical significance was calculated with two sample T-test.
RESULTS
For the patients who had reflux only on the transplanted kidney and were endoscopically treated, the febrile UTI frequency and renal outcome did not significantly improve. For the patients who had VUR to the native kidney(s) in addition to the transplanted kidneys and were treated for both the reflux to the native and transplanted kidneys by injection, there was a statistically significant reduction in febrile UTI rates (p<0.05), with 40% having no febrile UTI at all during the follow-up period (n = 26).
CONCLUSIONS
The febrile UTI in kidney transplant patients are more likely caused by the VUR to the native kidneys and the treatment should be planned accordingly.
17:55 - 17:58
S20-10 (OP)
Amane LACHKAR 1, Anne-Laure SELLIER-LECLERC 2, Guillaume ROSSIGNOL 1, Rémi DUBOIS 1, Frédéric HAMEURY 1, Justine BACCHETTA 2, Lionel BADET 3 and Delphine DEMEDE 1
1) Hôpital Femme Mère Enfant -Hospices Civils de Lyon, Pediatric surgery, Bron, FRANCE - 2) Hôpital Femme Mère Enfant -Hospices Civils de Lyon, Pediatric Nephrology, Bron, FRANCE - 3) Hospices Civils de Lyon, Urology and Kidney Transplantation department, Lyon, FRANCE
PURPOSE
Experience in combined liver-kidney transplantation (CLKT) in children is limited. We report results in cases of type 1 primary hyperoxaluria (PH1).
MATERIAL AND METHODS
Monocentric retrospective study including patients with PH1 who underwent a CLKT from 1992 to 2021.
RESULTS
We reported 14 patients including 7 girls. Median age and body weight was 3.7 years (1.0-18.6) and 13 kg (10-40); 11 patients weighed <15 kg at the time of CLKT. Waiting time for transplantation was 9.1 months (0.5-34.0). Mean age of donors was 9.1 years (0.5-34.0), with a median weight of 31 kg (11-60). All patients were on pre-transplant dialysis for 1.8 years (0.4-12.0): 10 on hemodialysis and peritoneal dialysis, 4 on hemodialysis alone. Post-operative hemodialysis was required for 7 patients.
2 low weight patients lost their renal graft due to vascular complications (1 arterial and 1 venous thrombosis). One was re-transplanted one year later, the other kept a correct residual renal function.
While 6 patients had normal oxaluria within 3 years, 4 others presented high oxaluria at 1, 2, 3 and 10 years after CLKT without consequences on kidney graft.
After 15 years follow-up (8.5-21.5), 13 patients had functioning renal graft, with a mean GFR of 67ml/min (25-96).
There was no liver graft loss despite 4 acute rejections, 3 vascular complications and 6 biliary complications. All patients survived with an improvement of their quality of life.
CONCLUSIONS
Combined pediatric liver-kidney transplantation in PH1 gives good long-term results, even in youngest children. Specific management of HP1 remains necessary after transplantation.