This work presents open and laparoscopic cystoplasty of different types and kidney transplants in patients with augmented bladder. The timing of kidney transplant before augmentation in patients with neurogenic bladder or with a previously augmented neurogenic bladder and results of these procedures are discussed, as well as urinary voiding problems in patients who have undergone kidney transplant. This report reinforces the conclusion that appropriately managed neurogenic bladder does not preclude successful kidney transplant.

Key words : Enterocystoplasty, Kidney transplantation, Laparoscopic cystoplasty, Vesicoureteral reflux

Introduction
Prevalence of chronic kidney disease is higher in patients with neurogenic bladder (NB) than in the general population despite recent progress in management of NB. There are several types of NB, and the most common type is characterized by detrusor sphincter dyssynergia with high pressure and uninhibited contraction with or without vesicoureteral reflux (VUR). Recurrent febrile pyelonephritis and progressive hydronephrosis may lead to renal scarring and end-stage renal disease (ESRD). The first goal in management of NB is to decrease high vesical pressure with medical management, such as treatment with anticholinergic drugs and clean intermittent catheterization (CIC) or botulinum toxin injection. If conservative medical management fails and there is deterioration of renal function, then augmentation cystoplasty should be considered an effective goal. Several types of augmentation, including enterocystoplasty, pyeloureterocystoplasty, ureterocystoplasty, and continent pouch with appendiceal continent stoma, can be used to manage end-stage NB. Open and laparoscopic cystoplasty of different types and kidney transplants in patients with augmented bladder are presented in this report. The timing of kidney transplant before augmentation in patients with NB or with a previously augmented NB and results of these procedures, as well as urinary voiding problems in patients who have undergone kidney transplant, are discussed.

History
During the 35-year period from 1984 through 2025, there were 6764 kidney transplants performed in our center, with 6295 of these transplant from living donors and 1469 from deceased donors. In 3446 of living donor transplants, laparoscopic nephrectomy was the method of procurement. The cases reported here were registered in the Collaborative Transplant Study registry (Figure 1, Figure 2). Bladder dysfunction will be discussed in 2 sections. The first section is a discussion of the lower urinary tract syndrome and overactive bladder in kidney transplant, followed by review of hostile bladder and its management. The bladder has 2 functions, that is, storage of urine and evacuation of urine. Disturbance of both functions can lead to frequency and nocturia. In about 50% of kidney recipients, urine output is less than 150 mL in 24 hours, whereas 30% of kidney recipients have anuria. About 12 weeks are needed to restore satisfactory bladder function after kidney transplant. Recovery could be limited by several factors, including urinary infection, previous surgery, thick-wall bladder due to bladder outlet obstruction, and long-standing anuria (defunctionalized bladder).¹ Overactive bladder (so-called small bladder) can cause unpleasant bladder sensation and painful voiding. Low-compliance bladder is a major cause of disrupted voiding frequency and nocturia. Overactive bladder and thick-wall bladder are 2 conditions that can cause high pressure in the lower urinary tract, which could deteriorate renal function in a transplanted kidney. Renal transplant recipients void significantly more often than patients without transplants, usually more than 7 voids per day. Renal transplant recipients might awaken from sleep at night more than twice for voiding. In about two-thirds of recipients, these symptoms will persist for a long time (2-3 years or more). Small bladder capacity, neurogenic etiology, urinary infection, bladder pain, prostate enlargement in male patients, and urethral stricture and meatal stricture in female patients can be the cause of disrupted frequency of voiding and nocturia in kidney recipients. Among the several types of NB, the most important type is detrusor-sphincter dyssynergia, in which, during bladder contraction, the urethral sphincter contracts instead of relaxing. Therefore, pressure increases significantly, leading to progressive hydronephrosis, VUR, and recurrent pyelonephritis, which can lead to ESRD. In patients with advanced NB (hostile bladder) and VUR, an antireflux procedure is not suitable during augmentation cystoplasty, because the bladder wall has been thickened by high pressure. Usually, augmentation of the bladder will reduce the pressure and thereby facilitate spontaneous dissipation of the reflux without the need for an interventional antireflux procedure. Our published studies have reported 130 patients with NB and reflux in whom reflux disappeared or significantly improved without the need for ureteral reimplantation during augmentation cystoplasty.^2,3 Therefore, augmentation cystoplasty without ureteral reimplantation can not only provide urinary continence but can also manage VUR and preserve the upper urinary tract (Figure 3, Figure 4). If a hostile bladder leads to ESRD, then augmentation cystoplasty will be necessary before or after transplant.⁴ Several surgical methods are used to treat a hostile bladder with or without reflux. Bladder augmentation with a piece of bowel, usually the ileum, is the most popular technique, which is called enterocystoplasty, and usually requires CIC after the procedure to empty the bladder (Figure 3, Figure 4). If the patient has end-stage urethra (uncorrectable urethral stricture) and catheterization is impossible, then in situ appendix transfer to an ileal pouch is a viable alternative procedure, as has been reported previously by our group^5,6 (Figure 5, Figure 6). In some recipients with hydronephrotic nonfunctioning native kidney, nephrectomy of the native kidney is performed. The dilated pelvis and ureter are tailored and used to augment the hostile bladder, which, in addition to increasing bladder volume and decreasing vesical pressure, may lead to disappearance of VUR7 (Figure 7, Figure 8). Controversy remains on the timing of augmentation cystoplasty and whether it should be performed before or after kidney transplant.⁸ Outcomes have been similar in reported cases. Basically, if the patient’s creatinine level is insufficient to require dialysis (chronic renal failure under medical management), then augmentation is performed before transplant. However, if the recipient is on dialysis, then kidney transplant is performed before augmentation cystoplasty. For patients with severe VUR, bladder augmentation could be deemed unnecessary in cases for which the volume of reflux units substantially decreases bladder pressure, and no harm is expected to the transplanted kidney. Of course, follow-up will dictate whether augmentation should be performed after kidney transplant.⁹

Representative Case
A 31-year-old patient with ESRD secondary to a hypertonic dyssynergic bladder and bilateral VUR had undergone augmentation cystoplasty 20 years earlier and had been performing CIC every 4 hours. Pretransplant imaging demonstrated bilateral VUR in the native kidneys (Figure 9). After renal transplant, a postoperative ultrasonography revealed no hydronephrosis in the transplanted kidney (Figure 10). The patient maintained excellent graft function, with a serum creatinine level of 1.3 mg/dL at 32 months of follow-up, and experienced no episodes of febrile urinary tract infection or pyelonephritis. This case reinforces the conclusion that appropriately managed NB does not preclude successful kidney transplant.