'Mini reimplantation' for the management of primary obstructed megaureter.

INTRODUCTION: The management of primary obstructed megaureter (POM) ranges from temporary double-J stenting to conventional ureteric reimplantation with tapering. Of late, several authors have favored refluxing reimplantation. In the present study the outcomes of 'mini reimplantation', where no tapering or advancement of the ureter was performed, have been analyzed.

METHODS: Records of all children (n = 28) who underwent reimplantation for POM from 2004 to 2014 were retrospectively analyzed. During the initial 5 years, a Cohen's reimplantation with excisional tapering was performed (Group 1, n = 15). Due to complications, the technique was modified in the second 5 years (Group 2, n = 13). In this group, after opening the bladder, the distal narrow segment and grossly dilated POM (around 3-5 cm) were excised (Figure). After closing the detrusor behind the ureter, the ureter was reimplanted again at the original position without tapering or advancement. Bladder mucosa was closed cranial to the new ureteric orifice, providing a ureter:tunnel ratio of 1:2 (mini reimplantation). All patients underwent repeat ultrasonogram and MAG3 renogram, with indirect at 6 months and 1 year after stent removal to exclude obstruction/vesicoureteral reflux (VUR).

RESULTS: In Group 1, a significantly higher proportion (P = 0.04) of patients (5/15) had to undergo repeat procedures for complications, compared with none in Group 2. In Group 1, there were two redo reimplants for recurrent obstructions; two nephrectomies for non-functioning kidneys; and one ureterostomy for pyonephrosis. Postoperative Grade 2-3 VUR was encountered in 3/15 patients in Group 1, and 2/13 patients in Group 2. These patients could be managed with antibiotic prophylaxis and no intervention was required.

DISCUSSION: Conventional management of POM involved initial cutaneous ureterostomy, followed by reimplantation with tapering of the ureter. Megaureter reimplantation with and without tapering has been reported to have no significant difference in outcomes between them. To avoid a potentially difficult operation in a small infant bladder, a refluxing reimplantation has been proposed; however, there is a high re-operation rate following this technique. The author feels that the reported technique is superior to the refluxing reimplantation, as there is no need for re-operation. The limitations of this study were the small numbers and short follow-up. However, the proposed 'mini reimplantation' with no tapering or advancement had good success rates in this small series. Further larger studies are required to support or negate the usefulness of this technique.