[Symptomatic reflux and stenosis of ureteroenteric anastomosis. Diagnostics and therapy]

Stenosis of the ureteroenterostomy and symptomatic reflux are among the most dangerous complications of all forms of urinary diversion. Variations in ureter implantation techniques and different surgical expertises are responsible for the heterogeneity of the available prevalence data. Antirefluxive implantation techniques seem to be more vulnerable to stenosis and obstruction than refluxive techniques, although no difference in kidney function deterioration over time was shown according to the presence or absence of reflux protection. Despite frequent controls, approximately one quarter of all obstructed renal units show a complete loss of function. The reimplantation rate of stenotic ureters exceeds 30%.The development of an implantation stenosis may be silent and subtle. The loss of renal function often remains unnoticed if sonography and creatinine measurements are the only follow-up tools employed. Neither of these tests is reliable in estimating kidney function and may mislead both doctor and patient. DMSA scintigraphy and retrograde contrast studies (conduitogram, pouchogram) are the most sensitive tools available to evaluate a symptomatic reflux, whereas MAG-3 renal scans and antegrade function tests (nephrostogram, renal pelvic pressure measurement) are recommended for investigating ureteric obstruction. Stenosis of the ureteroenterostomy usually occurs within 2 years after urinary diversion; delayed occurrence of ureteric obstruction is indicative of malignant local recurrence or compressive metastases.There are various minimally invasive treatment options such as balloon dilatation, internal ureterotomy, stenting and nephrostomy placement. However, the technical challenge of a ureteroenterostomy should not be a deterrent. In fact, if surgically possible, the patient should be offered open revision, since this is the only way to durably cure the underlying pathology and re-establish the already impaired quality of life of patients with urinary diversion as much as possible.