Stesura Seveso Archivio Italiano di Urologia e Andrologia 2024; 96(2):12389 1 ORIGINAL PAPER The disease in children is more complex than in adults, leading to specific challenges such as poor growth, cogni- tive problems, bladder dysfunction, and special dietary needs, which profoundly impact their quality of life (1, 2). Despite the availability of renal replacement therapy (RRT), children with severe renal failure face a signifi- cantly increased risk of mortality, approximately 30 times higher compared to their peers of the same age. Furthermore, children with hemodialysis experience low self-esteem, loss of identity, compromised body integrity, diminished control, and reduced independence (2). Kidney transplantation (KTx) remains the preferred treat- ment for both adults and children with ESRD. It offers reduced morbidity and mortality rates along with enhanced quality of life compared to RRT. However, despite KTx being a well-established procedure for adults, it is relatively rare in children (3). Even though there have been significant improvements in graft and patient outcomes, KTx remains a challenging procedure for pediatric patients. This is primarily due to factors like smaller recipients, congenital anomalies, and donor- recipient mismatches that lead to an increased risk of postoperative complications (3). It has also been reported that long-term graft survival rates in the pediatric popu- lation have not shown significant improvement, primari- ly due to factors like infections, episodes of acute rejec- tion, and suboptimal adherence to medication regimens (4). The existing literature on pediatric KTx predomi- nantly focuses on long-term outcomes for grafts and patients. However, there is a scarcity of data regarding the impact of pre-transplantation factors, donor-recipient mismatching, and the occurrence and consequences of surgical complications (3, 5). The present study is a case series aimed to show the expe- rience of the city of Sulaymaniyah regarding pediatric renal transplantation. METHODS Study design A retrospective single-group case series study was con- ducted on children with ESRD who were planned to undergo KTx from living donors between 2015 and Introduction: The rising prevalence of global end-stage renal disease (ESRD) is a signifi- cant health concern, especially among children. Although renal replacement therapy is available, children with ESRD are at an increased risk of mortality. Kidney transplantation is the pre- ferred modality of treatment and surpasses renal replacement therapy in terms of survival. However, pediatric renal trans- plantation could prove difficult due to factors like smaller recipients and donor-recipient mismatches leading to higher complications. Materials and methods: A retrospective single-group case series study was conducted on children with ESRD who were planned to undergo kidney transplantation from living donors between 2015 and 2021. The data was collected from two centers in the city of Sulaymaniyah. Results: The study comprised a predominantly male patient pop- ulation, with a total of 39 individuals (n = 39) and 13 female patients. The donors were mostly males between 25-40 years old. The majority of participants were 15-18 years old. In majority of the patients Thymoglobulin was the immunosuppres- sive agent used in induction. The most common etiology for renal failure was reflux nephropathy and artery anastomosis was performed to the external iliac artery in the majority of patients. Only 9 patients had complications following the trans- plantation and 3 patients had an episode of acute rejection. Conclusions: Renal transplantation is the preferred treatment of renal failure in pediatric patients in the city of Sulaymaniyah. The most common etiology for pediatric renal failure was reflux nephropathy which was different from the findings of North American Pediatric Renal Trials and Collaborative Studies. KEY WORDS: Kidney; Graft; End-stage renal disease; Pediatric renal transplantation. Submitted 15 February 2024; Accepted 22 February 2024 INTRODUCTION The global incidence of end-stage renal disease (ESRD) is currently escalating and posing a significant health con- cern worldwide. Chronic kidney disease (CKD) is a condi- tion characterized by irreversible injury to the kidneys that can advance to ESRD, the final stage of renal deteri- oration. ESRD is a devastating disorder associated with high mortality rates and cardiovascular complications. Pediatric renal transplantation: A single center experience Shakhawan Hama Amin Said 1, Saiwan Hayas Agha 1, Goran Fryad Abdulla 1, Mzhda Sahib Jaafar 1, Rawa Bapir 2-4, Nali H. Hama 1, 2, Ismaeel Aghaways 1, Aso Omer Rashid 1, Berun A. Abdalla 2, 4, Fahmi H. Kakamad 1, 2, 4 1 College of Medicine, University of Sulaimani, Sulaymaniyah, Kurdistan, Iraq; 2 Smart Health Tower, Madam Mitterrand Street, Sulaymaniyah, Kurdistan, Iraq; 3 Department of Urology, Sulaymaniyah Teaching Hospital, Sulaymaniyah, Kurdistan, Iraq; 4 Kscien Organization, Hamdi Street, Azadi Mall, Sulaymaniyah, Kurdistan, Iraq. DOI: 10.4081/aiua.2024.12389 Summary Archivio Italiano di Urologia e Andrologia 2024; 96(2):12389 S. Hama Amin Said, S. Hayas Agha, G. Fryad Abdulla, et al. 2 2021. The consent for participation and publication of data was obtained from the parents of patients. Ethical approval of the study was provided by the ethical com- mittee of the University of Sulaimani. Inclusion criteria All children younger than 18 years who underwent renal transplantations from living donors due to ESRD. Exclusion criteria Renal transplant cases older than 18 years old. Data collection The data was collected from two centers, Shar Hospital and Faruk Medical City, by reviewing the medical records of patients or filling out a specific questionnaire form by patients or their families. The extracted variables were patient demographics, etiology of renal failure, history of dialysis before transplantation, donor characteristics, the surgical technique of renal transplantation including the type of vascular and ureteric reconstruction, ischemia time, patient and graft survival, acute rejection episodes, reasons for graft failure, and cause of death. Doppler ultrasound of the graft had been performed within 24 hours of transplantation. Graft function had been moni- tored daily using plasma creatinine levels. The applied immunosuppression protocol (induction drugs and maintenance therapy) had been documented. Operative and postoperative adverse events had been graded using the Modified Clavien Dindo Scale of Complication Severity (6). Graft failure was defined as the failure of a renal transplant with a return to dialysis or the perform- ance of a second preemptive transplant. Acute rejection episode was defined as a rise in serum creatinine of at least 30% from baseline levels, accompanied by clinical symptoms and signs (fever, oliguria), and pathologic proof with a renal biopsy. Data analysis Data entry and coding were done using Microsoft Excel (Version 2010). Data analysis was performed using Statistical Package for the Social Sciences (SPSS) Version 24. Standard descriptive statistics, including percentages and mean ± standard deviation, were performed to analyze the data. RESULTS Our patients were grouped into 3 age categories. Only 9 (17.3%) of them were younger than 10 years old while the majority 31 patients 59.6% were between 15-18 years old. The remaining 12 (23.1%) patients were between 11-14 years old. Thirty-nine patients were male and con- stituted 75% of our data while the remaining 25% (13 patients) were females. The mean Body Mass Index (BMI) of our patients was 21.3 ± 1.69. The immunosuppressive pharmacologic agents used for induction were Thymoglobulin (used in 88.5% of our patients) and Basiliximab (used in only 6 patients). Only two patients had a history of previous transplantation and the other 50 patients were having their first attempt at renal transplantation. The majority of the donors were 25-40 years old and a minority of 5 donors were older than 40 years old. The majority (42, 80.8%) of the donors were male and the rest were female. Only 8 of the donors were related to the patients and the other 44 donors were non-related. The most common etiology for renal failure was reflux nephropathy which accounted for 21.2% of the patients. This was followed by Focal Segmental Glomerulosclerosis which accounted for 17.3% of the patients. Forty-six patients had a single graft artery which accounted for 88.5% of the cases. The rest of the patients had double artery grafts. Artery anastomosis was performed to the external iliac artery in the majority of the patients, accounting for 63.5% of them, and in the remaining patients it was anas- tomosed to the common iliac artery. Thirty-eight patients had the venous anastomosis done with the external iliac vein and in only 2 patients the anastomosis was per- formed with the Inferior Vena Cava (IVC). Post-operative evaluation of our patients showed only 9 patients had complications following the transplantation and 3 patients had an episode of acute rejection. Table 1 shows the recipient characteristics, etiologies of renal fail- ure, surgical techniques and post-operative data. Table 1. Recipient and Donor characteristics, etiology of renal failure, surgical technique. Recipient characteristics No. (%) Age group (years) < 10 9 (17.3) 11-14 12 (23.1) 15-18 31 (59.6) Gender Male 39 (75) Female 13 (25) Duration of dialysis < 1 37 (71.2) 1-3 4 (7.7) > 3 1 (1.9) No dialyzed 10 (19.2) Agent of induction Thymoglobulin 46 (88.5) Basiliximab 6 (11.5) Number of transplantations First 50 (96.2) Second 2 (3.8) BMI (Mean ± SD) 21.3 ± 1.69 Donor characteristics Age group < 25 17 (32.7) 25-40 30 (57.7) > 40 5 (9.6) Male 42 (80.8) Female 10 (19.2) Donors Related 8 (15.4) Non-related 44 (84.6) Etiology of renal failure Urological causes Reflux nephropathy 11 (21.2) Posterior urethral valve 2 (3.8) Archivio Italiano di Urologia e Andrologia 2024; 96(2):12389 3 Pediatric renal transplantation DISCUSSION Renal transplantation is the preferred modality for the treatment of ESRD. If possible, pre-emptive renal trans- plantation, which is transplantation before the need for dialysis, shows better results than early renal transplanta- tion. The analysis of our pediatric renal transplant patient data reveals a predominant demographic within the age bracket of 15-18 years, comprising 59.6% of the data. Subsequently, the following demographic consists of patients aged between 11-14 years, representing 23.1% of the total, while those under 10 years old account for 17.3%. This distribution of age segments aligns with the conclu- sions drawn from a study conducted by Chacko and col- leagues. Their findings similarly underscore a prevalence of older pediatric recipients in renal transplantation, with a mean age of 15 years. Consequently, it suggests a propensi- ty for renal transplantation among older children and ado- lescents (7). In terms of gender distribution, our data showed that 75% of the patients (n = 39) were male while only 25% were female (n = 13). In accordance with the data record- ed in the North American Pediatric Renal Trials and Collaborative Studies (NAPRTCS) registry, it has been observed that there exists an inverse correlation between the age group of patients and the male-to-female ratio. Specifically, as the age group of patients advances, the ratio of male to female patients tends to decrease. During infancy, the male patients made up 70% of the NAPRTCS data. At ≥ 18-year-old, this ratio decreases to 54.3% for males and 45.7% for female (8). Chacko et al. also found a disparity in male to female ratio in pediatric renal trans- plantation, where 65% of the patients in their study were male and only 35% were female (7). This was in contrast to a study by Barlas et al., in which a gender disparity was not as obvious and only 51.2% of their data were male (9). Also, in a paper by Kavas and colleagues, out of 37 patients, 20 of them were male and 17 were female (10). In a study conducted by Hogan and colleagues that investi- gated gender disparities in access to pre-emptive pediatric renal transplantation in Europe, revealed a significant gen- der disparity, indicating that girls were 23% less likely to undergo a pre-emptive renal transplant when compared to boys. This outcome underscores the existence of gender- related discrepancies in the accessibility of pre-emptive renal transplantation within the pediatric population in Europe, warranting further exploration into the factors contributing to this observed disparity (11). The most common cause of renal failure in our patients was reflux nephropathy which accounted for 21.2% of the patients. While the second most common cause was Focal Segmental Glomerulosclerosis (FSGS) which accounted for 17.3% of the patients. In accordance with the NAPRTCS registry, it is noteworthy to underscore that renal dyspla- sia in infants emerges as the predominant etiology of renal failure within the pediatric age group. However, as age advances, the probability of renal dysplasia serving as the primary causative factor for renal failure diminishes. Notably, upon reaching the age of 18 years and beyond, focal segmental glomerulosclerosis (FSGS) emerges as the predominant cause of renal failure. Subsequently, obstruc- tive uropathy ranks second in prevalence, while renal dys- plasia occupies the third position in the hierarchy of causative factors for renal failure (8). Our findings were in contrast to a paper by Kavaz et al. where the most common cause of ESRD was juvenile nephronophthisis (N = 11 out of 37 patients). Reflux nephropathy was found to be the cause of renal failure in only 2 patients and Focal segmental glomerulosclerosis was determined to the cause in 4 patients (10). In the study conducted by Barlas and colleagues, it was identified that vesicoureteral reflux and primary glomeru- lar disease were the predominant etiologies leading to ESRD (9). The similarity in our findings prompts ques- tions regarding whether the high prevalence of reflux nephropathy and primary glomerular disease as primary causes of ESRD is attributable to a smaller sample size within our centers, or if it is a consequence of the geo- graphic proximity of the two centers, where both are located in neighboring countries. While most of our patients had no complication post-oper- atively, the most common complication in our data proved to be urinary tract infection which accounted for 9.6% (n = 5) of our complications. The most common complications in a study by Beetz et al. were vascular complications for which 34 (15.4%) patients needed surgical revision of their transplantations. Also, urinary tract infections accounted for 6.3% of their overall complications (3). Hemorrhage Non-urological causes Alport syndrome 4 (7.7) B.K. nephropathy 1 (1.9) FSGS 9 (17.3) IgA nephropathy 5 (9.6) Minimal change disease 5 (9.6) Nephronophthisis 3 (5.8) Nephrotic syndrome 1 (1.9) Primary hyperoxaluria 2 (3.8) Renal dysplasia 3 (5.8) Wegner granulomatosis 1 (1.9) Unknown cause 5 (9.6) Surgical technique Number of arteries graft kidney Single 46 (88.5) Double 6 (11.5) Artery anastomosis External iliac end to side 33 (63.5) Common iliac end to side 19 (36.5) Vein anastomosis External iliac end to side 38 (73.1) Common iliac end to side 12 (23.1) IVC end to side 2 (3.8) Ureter anastomosis Lich Gregoir 52 (100) Post-operative data POC Urinary tract infection 5 (9.6) CMV colitis 2 (3.8) Bleeding 2 (3.8) Drug-induced press 1 (1.9) Chest infection 1 (1.9) No significant complication 41 (79) Rejection One episode of rejection 3 (5.8) No rejection 49 (94.2) Archivio Italiano di Urologia e Andrologia 2024; 96(2):12389 S. Hama Amin Said, S. Hayas Agha, G. Fryad Abdulla, et al. 4 accounted for 3.8% of our complications. This goes in line with the complications of a study done by Irtan et al., where only 2 out of 202 patients had hemorrhage (12). The dif- ference among these numbers could be explained by the difference in sample size, where Beetz et al. had a larger sample size of 221 patients and Irtan et al. had a sample size of 202 patients (3, 12). The main limitation of our study was a lack of a compar- ison group, hence correlating the preoperative variables to graft survival could not be done appropriately and establishing causations was not possible. The sample size was small and cannot be generalized for the whole population. Also, the retrospective nature of the study is another limitation. CONCLUSIONS Renal transplantation is the preferred treatment of renal failure in pediatric patients in the city of Sulaymaniyah. 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Correspondence Shakhawan Said, MD shakhwan.said@gmail.com Saiwan Agha, MD saiwan.agha@gmail.com Goran Abdullah, MD goran.abdullah@gmail.com Mzhda Jafaar, MD mzhda.jafaar@gmail.com Nali Hama, MD nali.hama12@gmail.com Ismaeel Aghaways, MD ismaeelagha@hotmail.com Aso Rashid, MD aso.rashid@univsul.edu.iq Fahmi Kakamad, MD (Corresponding Author) fahmi.hussein@univsul.edu.iq College of Medicine, University of Sulaimani, Sulaymaniyah, Kurdistan, Iraq Doctors City, Building 11, Apartment 50, Sulaimani, 46001 Iraq Rawa Bapir, MD dr.rawa@yahoo.com Berun Abdalla, MD berun.anwer95@gmail.com Smart Health Tower, Madam Mitterrand Street, Sulaymaniyah, Kurdistan, Iraq Conflict of interest: The authors declare no potential conflict of interest.