Nephrol Dial Transplant (1996) 11: 1637-1638
Case Report
Nephrology
Dialysis
Transplantation
Intermittent ureteric obstruction caused by 'floating' renal transplant
M. Asim and J. H. Turney
The General Infirmary at Leeds, Leeds, UK
Introduction
Ureteric complications have been reported in approximately 13% of cadaveric renal transplants, although
worldwide experience has varied considerably [1].
Obstructive uropathy due to ureteric obstruction constitutes a significant percentage of these complications
[1,2]. We report intermittent obstruction of the transplanted ureter due to kinking related to posture.
Case report
A 35-year old man with end-stage renal failure due to
IgA nephropathy successfully underwent cadaveric
renal transplantation. He was obese, weighing 95 kg.
About 8 months after transplant he complained of
continuing nocturnal frequency of micturition. He had
apparently suddenly started to retain fluid during
waking hours, passing urine perhaps once during the
day, and developing peripheral oedema. This was
accompanied by severe nocturnal frequency on 6-8
occasions each night, the diuresis developing within
30-45 min of lying down and gradually decreasing
throughout the recumbent period. The function of the
transplanted kidney was stable with a creatinine of
227 umol/1.
A MAG3 renogram was performed in two phases
(Figure 1). Initially, the renogram was performed in
the erect position and imaging continued for 40 min.
This showed prolonged accumulation of activity in the
kidney (L) with slow drainage andfillingof the bladder
(B), resulting in slow fall-off of the renogram trace.
The second-phase renogram was performed with the
patient supine. In this position there was more rapid
clearance of activity from the transplanted kidney
(LK). Ultrasound of the transplanted kidney did not
demonstrate increased dilatation of the collecting
system, nor obvious renal mobility.
The transplant ureter was stented (using a 24 cm
French size 6 silicone stent), with restoration of the
1. a MAG3 renogram performed in erect position showing
normal circadian pattern of micturition, clearing of Fig.
obstructive pattern in transplanted kidney (L) and slow filling of
bladder (B). b MAG3 renogram performed in supine position
showing clearance of activity from transplanted kidney (LK) and
Correspondence and offprint requests to: Dr J. H. Turney, Consultantaccumulation of tracer in bladder (B).
Renal Physician, The General Infirmary, Great George Street, Leeds,
LSI 3EX, UK.
© 1996 European Dialysis and Transplant Association-European Renal Association
M. Asim and J. H. Turney
1638
Fig. 2. MAG3 renogram performed in erect position following stenting of the transplanted ureter, showing essentially normal
appearances.
peripheral oedema, weight reduction, and improvement
of serum creatinine to 160 umol/1. Repeat MAG3
renogram (Figure 2) showed essentially normal
appearances for a transplanted kidney, with good
uptake and prompt filling of the bladder.
Discussion
Our patient experienced intermittent obstruction probably due to kinking or twisting of the transplanted
ureter when in the erect position. The intermittent
obstruction was relieved by ureteric stenting. Clearly
his obesity was a significant contributory factor as it
allowed the kidney freedom to move and hence kink
the ureter on standing, and to float back when the
patient was supine.
Mobility of normal kidneys with downward displacement to the iliac fossa is occasionally observed—the
so-called floating kidney. This is more common in
women, and laxity of the abdominal wall is a predisposing factor. Nephroptosis is almost always asymptomatic but remarkable renal descent has been described,
which resulted in intractable pain from hydronephrosis
and which was relieved by nephropexy [3]. In adults,
transplanted kidneys are usually placed extraperitoneally in an abdominal muscle pouch in the iliac fossa.
Fixation of the grafted kidney is of little value and
may even cause kinking of the vessels or ureter [4].
Obstructive uropathy may be a major complication of
renal transplantation and may result from intrinsic
ureteric obstruction from blood clot or calculi; extrinsic
obstruction from urinoma, lymphocele, fibrosis, or
haematoma; necrosis and subsequent fibrosis of the
avascular lower ureter; or twisted ureter [5]. The
transplant kidney is denervated, and the pain and renal
colic usually associated with obstruction are normally
absent [6]. Urological complications of renal transplantation are important not only because they must
be distinguished from graft rejection as a cause of graft
dysfunction, but also because of the general urological
implications of a compromised solitary kidney.
References
1. Shoskes DA, Hanbury D, Cranston D, Morris PJ. Urological
complications in 1000 consecutive renal transplant recipients.
J Urol 1995; 153: 18-21
2. Loughlin KR, Tilney NL, Richie JP. Urological complications
in 718 renal transplant patients. Surgery 1984; 95: 297-302
3. Urban DA, dayman RV, Kerbl K, Figenshau RS, McDougall
EM. Laparoscopic nephropexy for symptomatic nephroptosis:
initial case report. J Endourol 1993; 7: 27-30
4. Allen RDM, Chapman JR. A Manual of Renal Transplantation.
Edward Arnold, London, 1994
5. Mundy AR, Podesta ML, Bewick M, Rudge CJ, Ellis FG. The
urological complications of 1000 renal transplants. Br J Urol
1981; 53: 397-402
6. Cranston D. Urological complications after renal transplantation. In: Morris PJ, ed. Kidney Transplantation, 4th edn. WB
Saunders, Philadelphia, 1994; 330-338
Received for publication: 10.3.96
Accepted: 20.3.96