Evaluating pediatric ureteropelvic junction obstruction:Dynamic magnetic resonance urography vs renal scintigraphy 99mtechnetium mercaptoacetyltriglycine

BACKGROUND Ureteropelvic junction obstruction(UPJO)is a common congenital urinary tract disorder in children.It can be diagnosed as early as in utero due to the presence of hydronephrosis or later in life due to symptomatic occurrence.AIM To evaluate the discrepancy between dynamic contrast-enhanced magnetic resonance urography(dMRU)and scintigraphy 99m-technetium mercaptoacetyltriglycine(MAG-3)for the functional evaluation of UPJO.METHODS Between 2016 and 2020,126 patients with UPJO underwent surgery at Robert DebréHospital.Of these,83 received a prenatal diagnosis,and 43 were diagnosed during childhood.Four of the 126 patients underwent surgery based on the clinical situation and postnatal ultrasound findings without undergoing functional imaging evaluation.Split renal function was evaluated preoperatively using scintigraphy MAG-3(n=28),dMRU(n=53),or both(n=40).In this study,we included patients who underwent surgery for UPJO and scintigraphy MAG-3+dMRU but excluded those who underwent only scintigraphy MAG-3 or dMRU.The patients were divided into groups A(<10%discrepancy)and B(>10%discrepancy).We examined the discrepancy in split renal function between the two modalities and investigated the possible risk factors.RESULTS The split renal function between the two kidneys was compared in 40 patients(28 boys and 12 girls)using scintigraphy MAG-3 and dMRU.Differential renal function,as determined using both modalities,showed a difference of<10%in 31 children and>10%in 9 children.Calculation of the relative renal function using dMRU revealed an excellent correlation coefficient with renal scintigraphy MAG-3 for both kidneys.CONCLUSION Our findings demonstrated that dMRU is equivalent to scintigraphy MAG-3 for evaluating split renal function in patients with UPJO.

Tunneled tubularized bladder mucosal graft for long urethral reconstruction:is it a reliable option in selected complex cases in children and adolescents?

Aim:We analyzed the use of tubularized tunneled bladder mucosa graft(TBMG)and its application as a salvage procedure or as primary surgery for long urethroplasty in children and adolescents.Specific attention was given to a new method to harvest a long bladder mucosa graft through a minimal detrusotomy.Methods:We analyzed the files of 10 patients who underwent TBMG urethroplasty at median age of 105 months(range 20-195 months).The indications were perineal hypospadias cripple in two,masculinizing genitoplasty for ovotesticular Ovotesticular Disorder of Sex Development(DSD)in two,perineal hypospadias in four,duplicated urethra in one,and complications of circumcision in one.Staged reconstruction was performed in all patients.The first stage was removal of all fibrous tissues and efficient treatment of curvature and skin coverage.After a minimal delay of one year,a free bladder mucosa graft was harvested through a minimal detrusotomy and tubularized.Tunneling of the graft was proceeded from the perineal urethrostomy to the glans.Results:The graft was successfully harvested through the minimal detrusotomy approach for variable lengths of urethroplasty;the median length was 10.5 cm(range 8-16 cm).The median follow up was 61.7 months(range 18-160 months).TBMG was the last surgery with no redo in five cases(50%).Long stricture occurred in one case of primary perineal hypospadias and needed a redo staged surgery.Two patients performed self-dilatation for distal stenosis.Conclusion:The tunneled bladder mucosa tube graft technique represents a good alternative for a long urethroplasty in patients with a paucity of healthy skin.The minimal detrusotomy technique for graft retrieval may reduce graft harvesting morbidity.