Subureteral polydimethylsiloxane injection versus extravesical reimplantation for primary low grade vesicoureteral reflux in children: a comparative study

Correlation of Renal Scarring to Urinary Tract Infections and Vesicoureteral Reflux in Children

Objective

To study the association of the grade of vesicoureteral reflux (VUR) and urinary tract infections (UTI) with renal scarring at the first clinical presentation of patients who underwent antireflux surgery. Materials and methods. Between 2015 and 2020, 150 patients (194 units) who underwent antireflux surgery had dimercaptosuccinic acid (DMSA) renal scans preoperatively. Patients were classified into the nonscar and scar groups according to DMSA scan results. Moreover, cases were classified into afebrile UTI, febrile UTI, and antenatal hydronephrosis (ANH) according to the mode of presentation. We correlated the mode of presentation and the grade of VUR to the presence/absence of renal scars in both groups.

Results

The mean follow-up was 45 months preoperatively. The mode of presentation was afebrile, febrile UTIs, and antenatal hydronephrosis in (50, 14), (20, 46), and (10, 10) patients in the nonscar and scar groups, respectively. Of the 20 patients who presented ANH, 10 (50%) had scars. Clinical presentation was correlated to the presence of renal scarring and its degree. The scar group had significantly higher grades of VUR than the nonscar group (grades I–II (50 units versus 10 units), grade III (28 units versus 40 units), and grade IV–V (22 units versus 44 units) for the nonscar versus scar groups, respectively (pvalue <0.001).

Conclusion

Renal scarring is associated with higher grades of reflux and urinary tract infections. We advocate further research investigating infants who had UTIs with or without fever for early detection of reflux.

Autologous adipocyte graft in endoscopic treatment of vesico-renal reflux in children: a preliminary study

No bulking agent is ideal for endoscopically treating vesico-renal reflux in children. Many teams have tried to find a safe and efficient material, ideally an autologous material. We describe here a protocol for the use of autologous viable fat in the treatment of primary vesico-renal reflux in children aged from 3 to 15 years. Fat harvesting was done from the medial side of the thigh by manual aspiration. Samples were centrifuged to purify the graft from blood and lipid. Lastly fat was injected beneath the pathologic ureter by a conventional endoscopic technique. A voiding cystourethrography (VCUG) closed the procedure. Follow-up included renal ultrasonography the day after surgery, and one and three months later. A VCUG was performed systematically at three months and, in cases of acute pyelonephritis, during the survey.Sixty-four children with 94 refluxing units were treated by autologous fat injection with a follow-up from 6 to 40 months. At the end of the procedure, we systematically obtained a very good increase in height of the pathologic meatus and VCUG was normal in all cases. None presented with an obstruction during the follow-up period. Two children presented with an acute pyelonephritis before the third month. At three months, VCUG was not realized in 14 cases (22%) because the parents refused the procedure. One of those children presented with an acute pyelonephritis five months after endoscopic treatment. VCUG was normal for 17 of 50 children (34%), and showed a real improvement for 19 other children (38%). Three children had a surgical reimplantation because of the persistence of an unchanged high-grade vesico-renal reflux; histological examination found viable adipocytes on sections of the distal pathologic ureter. Clinically, 11 children (17%) presented with an acute pyelonephritis after treatment at a mean follow-up time of 10 months.These preliminary findings led us to modify the technique in order to improve our results. Our first concern is feasibility and safety of this technique, regardless of the use of other synthetic bulking agents the innocuousness of which is uncertain.

Cystoscopic correction of reflux

Vesicoureteral reflux is a well-recognized cause of childhood illness and renal damage. In the past, surgical reimplantation had been the only procedure available to gain the immediate cessation of reflux. The development of an endoscopic injection technique as a less morbid alternative to traditional surgery began in the 1980s. Teflon was the first injectable agent to be investigated. The record of Teflon is one of efficacy and apparent patient tolerance. However, concerns regarding possible migration and other side effects led to a search for other injectable agents. The most recently investigated agents are polydimethylsiloxane and dextranomer polymer. These agents do not have the long-term follow-up of Teflon, but appear to be effective and safe. Time will tell which agent will become the implant of choice, but it seems clear that endoscopic management will play an increasingly larger role in the care of vesicoureteral reflux.