[Kidney transplantation in children with complex urogenital malformations-what should be considered?] / Kindernierentransplantation bei komplexen urogenitalen Fehlbildungen ­ was gibt es zu beachten?

BACKGROUND: Congenital anomalies of the kidneys and urinary tract (CAKUT) are the most common cause of end-stage renal disease (ESRD) in children. Approximately one third of children with CAKUT have lower urinary tract dysfunction (LUTD). AIM: This article highlights the important aspects that need to be considered in kidney transplantation of children with complex urogenital malformations. MATERIALS AND METHODS: The paper reviews the existing literature regarding the evaluation, preparation, perioperative management, and follow-up of children with complex urogenital malformations and ESRD undergoing renal transplantation. RESULTS: Comprehensive diagnostics are required before any pediatric kidney transplantation. If LUTD is suspected, voiding cystourethrography and a urodynamic examination should be performed. Treatment of symptomatic vesicoureterorenal reflux and LUTD is mandatory prior to pediatric kidney transplantation. Following successful kidney transplantation of children with congenital urogenital malformations, lifelong follow-up is required. Regular reevaluations of the bladder by means of urodynamic examinations are necessary. In patients following bladder augmentation with intestinal segments or urinary diversions in childhood, regular endoscopic examinations of the urinary tract are recommended to rule out secondary malignancy. CONCLUSION: Treatment of children with complex urogenital malformations should be carried out in centers with appropriate expertise.

Risk Factor Analysis for Long-Term Graft Survival Following Pediatric Kidney Transplantation: The Importance of Pretransplantation Time on Dialysis and Donor/Recipient Age Difference.

Recognizing risk factors that may negatively affect long-term graft survival following pediatric kidney transplantation is a key element in the decision-making process during organ allocation. We retrospectively reassessed all cases of pediatric kidney transplantation performed in our center in the last 20 years with the aim of determining baseline characteristics that could be identified as prognostic risk factors for long-term graft survival. Between 2001 and 2020, a total of 91 kidney transplantations in children under the age of 18 years were undertaken in our center. Early graft failure was observed in six of the 91 patients (7%). The median follow-up of the remaining 85 children was 100 months, and the overall kidney graft survival rates at 5, 10, 15 and 20 years were 85.2%, 71.4%, 46.0% and 30.6%, respectively. Small children with a body surface area of <1 m2 were significantly associated with better long-term graft survival outcomes, while adolescents aged more than twelve years showed poorer graft survival rates than younger children. Body surface area of the recipient of ≥1 m2, pretransplantation duration of the recipient on dialysis ≥18 months, hemodialysis prior to transplantation and donor/recipient age difference of ≥25 years were significantly associated with poorer long-term graft survival.

Exome Survey and Candidate Gene Re-Sequencing Identifies Novel Exstrophy Candidate Genes and Implicates LZTR1 in Disease Formation.

BACKGROUND: The bladder exstrophy-epispadias complex (BEEC) is a spectrum of congenital abnormalities that involves the abdominal wall, the bony pelvis, the urinary tract, the external genitalia, and, in severe cases, the gastrointestinal tract as well. METHODS: Herein, we performed an exome analysis of case-parent trios with cloacal exstrophy (CE), the most severe form of the BEEC. Furthermore, we surveyed the exome of a sib-pair presenting with classic bladder exstrophy (CBE) and epispadias (E) only. Moreover, we performed large-scale re-sequencing of CBE individuals for novel candidate genes that were derived from the current exome analysis, as well as for previously reported candidate genes within the CBE phenocritical region, 22q11.2. RESULTS: The exome survey in the CE case-parent trios identified two candidate genes harboring de novo variants (NR1H2, GKAP1), four candidate genes with autosomal-recessive biallelic variants (AKR1B10, CLSTN3, NDST4, PLEKHB1) and one candidate gene with suggestive uniparental disomy (SVEP1). However, re-sequencing did not identify any additional variant carriers in these candidate genes. Analysis of the affected sib-pair revealed no candidate gene. Re-sequencing of the genes within the 22q11.2 CBE phenocritical region identified two highly conserved frameshift variants that led to early termination in two independent CBE males, in LZTR1 (c.978_985del, p.Ser327fster6) and in SLC7A4 (c.1087delC, p.Arg363fster68). CONCLUSIONS: According to previous studies, our study further implicates LZTR1 in CBE formation. Exome analysis-derived candidate genes from CE individuals may not represent a frequent indicator for other BEEC phenotypes and warrant molecular analysis before their involvement in disease formation can be assumed.

Retrospective histological evaluation of orchiectomy specimens following testicular torsion reveals a 10% incidence of reversible injury. Is it time for a change of strategy?

BACKGROUND: According to standard medical practice, immediate orchiectomy is advised in the case of a non-viable testis following testicular torsion. Because of the lack of objective criteria in the evaluation of testicular viability, the fate of the testis solely depends on the discretion and experience of the surgeon. OBJECTIVE: In this study, we retrospectively reassess the management of patients with testicular torsion in our center, and we ask the question, from a retrospective point of view, of whether the decision to perform orchiectomy has always been correct. MATERIALS AND METHODS: We retrospectively reviewed all cases of patients with testicular torsion who underwent surgery in our center between 2001 and 2021. All orchiectomy specimens were reevaluated and graded by an experienced pathologist using the Mikuz grading system. RESULTS: Immediate orchiectomy was performed in 48 of the 136 patients (35%). Five (10.4%) of the 48 orchiectomy specimens were categorized as "grade 1," and 17 (35.4%) were categorized as "grade 2." The time between the onset of symptoms and surgical exploration exceeded 12 h in three of the five patients with a "grade 1" testicular injury, and in one case, it even exceeded 24 h. DISCUSSION: "Grade 1" testicular injury is potentially reversible, whereas the fate of a testis with a "grade 2" testicular injury remains unknown. Whether and to what extent partial testicular tissue salvage in a "grade 2" injury is still possible remain unclear. CONCLUSIONS: Our results indicate that at least 10% of the testicles removed in our center could, from a retrospective point of view, have been salvaged. Our study further demonstrated that the duration of symptoms is not an absolute indicator of testicular damage and that the decision of whether orchiectomy should be performed, based simply on the subjective macroscopic image of the affected testis, is not always correct.

Clean Intermittent Catheterization in Children under 12 Years Does Not Have a Negative Impact on Long-Term Graft Survival following Pediatric Kidney Transplantation.

BACKGROUND: Congenital anomalies of the kidneys and urinary tract (CAKUTs) are one of the most prevalent primary causes of end-stage renal disease (ESRD) in young children, and approximately one-third of these children present with lower urinary tract dysfunction (LUTD). Many children with LUTD require therapy with clean intermittent catheterization (CIC). CIC commonly leads to bacteriuria, and considerations have arisen regarding whether CIC in immunosuppressed children is safe or whether repeated febrile urinary tract infections (UTIs) may lead to the deterioration of kidney graft function. MATERIAL AND METHODS: We retrospectively reviewed all cases of primary kidney transplantation performed in our center between 2001 and 2020 in recipients aged less than twelve years. The number of episodes of febrile UTIs as well as the long-term kidney graft survival of children undergoing CIC were compared to those of children with urological causes of ESRD not undergoing CIC, as well as to those of children with nonurological causes of ESRD. RESULTS: Following successful kidney transplantation in 41 children, CIC was needed in 8 of these patients. These 8 children undergoing CIC had significantly more episodes of febrile UTIs than did the 18 children with a nonurological cause of ESRD (p = 0.04) but not the 15 children with a urological cause of ESRD who did not need to undergo CIC (p = 0.19). Despite being associated with a higher rate of febrile UTIs, CIC was not identified as a risk factor for long-term kidney graft survival, and long-term graft survival did not significantly differ between the three groups at a median follow-up of 124 months. CONCLUSIONS: Our study demonstrates that, under regular medical care, CIC following pediatric transplantation is safe and is not associated with a higher rate of long-term graft loss.

Urethral Plate Characteristics in Cases of Non-proximal Hypospadias May Not Be Associated With a Higher Risk of Complications When a Two-Stage Repair Is Applied.

Purpose: To investigate whether a two-stage repair of distal- and mid-shaft hypospadias (non-proximal hypospadias) could eliminate the risk factors resulting from adverse urethral plate characteristics and eventually reduce complication rates. Methods: We retrospectively reviewed all cases of primary surgical repair of non-proximal hypospadias performed in our center between 2009 and 2018. In all cases where adverse urethral plate characteristics were found, such as meatal stenosis, a shallow urethral groove, a thick web of tissue between the native meatus and the urethral groove or in the presence of a very "thin," skin-like distal urethra, a two-stage repair was routinely undertaken. In cases of native meatal stenosis, a meatotomy, and meatoplasty were performed. In cases of a very "thin" distal urethra we incised the skin proximally up to the point of a normal urethral fold and a meatoplasty was performed at that point. Hypospadias repair was then performed in a second operation, 3-6 months following the first procedure. Urethroplasty, both in cases of a single-stage repair and in cases of a two-stage repair, was always performed using the Thiersch-Duplay technique. Patients with a follow-up of less than 12 months were excluded from this study. Results: Over a period of 10 years, 208 boys underwent primary surgical repair of non-proximal hypospadias. Eighty-nine of the 208 patients (42.8%) underwent single-stage hypospadias repair. Two-stage repair of the hypospadias was required in 119 (57.2%) of the patients. The overall complication rate was 3.4% in the group operated in a single stage and 7.6% in the group that required a two-stage repair (p = 0.09). The most frequent complication reported was urethrocutaneous fistula (p = 0.31), followed by meatal stenosis (p = 0.37), urethral stricture (p = 0.08) and wound dehiscence (p = 0.16). There was no significant difference between the complication rates of the two groups. Conclusion: Patients with distal hypospadias and poor urethral plate characteristics repaired in a two-stage approach have comparable low-complications to those with favorable urethral plate characteristics repaired in a single-stage.

Blunt renal trauma-induced hypertension in pediatric patients: a single-center experience.

PURPOSE: Children have a greater chance of sustaining a renal injury than adults and higher odds of having a high-grade renal injury. Hypertension is a rare complication of blunt renal trauma, with risk being higher in cases of major renal trauma. We reviewed the cases of pediatric blunt renal trauma-induced hypertension in our tertiary referral center in an attempt to better understand this rare condition. STUDY DESIGN: A retrospective evaluation of children under the age of 18 who were admitted to our department during the last 20 years and were diagnosed with blunt renal trauma. RESULTS: Twenty-three children presented with blunt renal trauma, one of whom was treated with emergency nephrectomy. Four children (18%) developed post-traumatic hypertension. All four cases were associated with a reduction in blood flow to the kidney, either through injury to the renal artery (in three cases) or through extrinsic compression of the kidney by a large perirenal hematoma (Page kidney; in one case). The Page kidney case developed hypertension during the initial hospitalization, and it resolved spontaneously after five months through the gradual resorption of the perirenal hematoma. Among the three cases of renal artery injury, hypertension during the initial hospitalization was only observed in one case, with hypertension in the other two cases manifesting after two months and four years, respectively. All three cases of renal artery injury resulted in a complete loss of function of the injured kidney, and two cases were treated with nephrectomy. Following nephrectomy, the blood pressure level returned to normal within a few days. DISCUSSION: Development of hypertension following a blunt renal trauma can be heterogenous, with the time of manifestation stretching between days after the accident and years thereafter. Children have a higher risk of renal trauma and, according to published data out of the National Trauma Data Bank, a 20-times higher risk of renal artery injury in comparison to the adult population. Large multicenter studies are required to answer the question of whether children are therefore more prone to blunt renal trauma-induced hypertension than adults. CONCLUSIONS: Our study highlights the importance of blood pressure monitoring in children following blunt renal trauma, as post-traumatic hypertension can develop even years after the accident. In cases of a poorly functioning kidney, nephrectomy may be regarded as a curative therapy.