Colossal renal allograft hydronephrosis causing abdominal distension
A 63‐year‐old woman, with a cadaveric renal transplant since 1988, developed graft hydronephrosis (HN) in 2001. Retrograde pyelogram (RP) revealed a dilated transplant ureter down to the vesico‐ureteric junction (VUJ) and ureteroscopy identified a scarred neo‐ureteral orifice with an obliterated lumen. Balloon dilatation was performed, but subsequent reassessment ultrasound (USG) demonstrated residual graft HN. The patient underwent serial USG monitoring and renal function remained preserved (serum creatinine around 110–120 umol/L) for many years. Allograft function worsened in 2008 and a repeat RP demonstrated a recurrence of the VUJ stricture. Balloon dilatation was re‐performed and the serum creatinine returned to baseline. Subsequent serial USG monitoring demonstrated a slow progression of the graft HN but serial radioisotope scans showed no significant deterioration in renal function or urinary drainage. During this period, the patient was free from recurrent urinary tract infections and nephrolithiasis, but in 2014, a reduction pyeloplasty to excise the redundant hydronephrotic renal pelvis had to be performed to relieve the increasing abdominal discomfort. A pre‐operative CT scan demonstrated massive (31 × 21 cm) graft HN extending from the level of hiatus to the sacrum, resulting in displacement of abdominal viscera to cause symptomatic distension (Fig. 1). A total of 15 L of urine was drained intraoperatively and greater than 20 kg body weight reduction was noted upon discharge. Allograft function has remained stable ever since with a serum creatinine of approximately 130 µmol/L.
Renal allograft ureteric stenosis has been reported to occur with a varying incidence between 0.6 %1 and 12.5 %.2 In the majority of cases, it occurs in the distal ureter and arises early in the post‐transplantation period.3 The causes underlying this complication mainly include ureteric ischaemia, BK polyoma virus infection and in rare circumstances, urothelial tumours or extrinsic compression. Unfortunately, the majority of cases will require urological intervention, which may involve balloon dilatation, stenting, surgical re‐implantation or reconstruction to preserve allograft function. It is therefore prudent to institute serial surveillance imaging, as illustrated in this reported case, to assess allograft structure and function following renal transplantation. This would facilitate timely urological intervention to preserve renal graft function.