AARON D. MARTIN
H. GIL RUSHTON
Ureteral surgery and various conditions, including trauma, stricture, neoplasm, or a previous failed surgical procedure, can render a ureter inadequate for successful ureteroureterostomy or ureteroneocystostomy. Transureteroureterostomy (TUU), first described by Higgins (1) in the 1930s, has gained increased prominence in pediatric urology as a method to compensate for a lacking or defective distal ureter. In some cases, bridging the midureter to the contralateral ureter via TUU may salvage a renal unit, especially in cases when an ipsilateral psoas hitch and/or Boari flap are insufficient to accomplish this task. In other situations, TUU can be performed as a salvage procedure following previous failed ureteral surgery (2,3). More recently, TUU has been employed in complex reconstructive procedures that entail harvesting of the distal donor ureter for alternative purposes, including augmentation ureterocystoplasty or as a continent catheterizable conduit (2).
In the majority of cases in pediatric urology, TUU is employed as part of a planned reconstruction. The preoperative workup requires thorough assessment of bilateral renal function and drainage, knowledge of the anatomy of both the donor and recipient ureters, and careful evaluation of bladder function. Differential renal function and drainage are most objectively determined by preoperative MAG-3 renal scintigraphy. Sonography can aid in determining the presence and severity of hydronephrosis. Contrast imaging with intravenous, retrograde, or antegrade pyelography may be necessary in select cases when detailed anatomic definition of the ureters is required. Contrast voiding cystography is the best modality to assess for the presence of vesicoureteral reflux, which, when present, provides a “free” retrograde ureteropyelogram. In cases involving children with abnormal or neuropathic bladder function, preoperative urodynamics is required to evaluate bladder capacity, compliance, and emptying.
Less commonly in children than in adults, initial recognition of a ureteral injury requiring a TUU occurs intraoperatively during resection of a tumor or during exploration for trauma. Fortunately, in the majority of these cases, one can usually anticipate a normal recipient ureter and bladder.
INDICATIONS FOR SURGERY
The primary goal of a TUU is to reestablish nonobstructive, nonrefluxing drainage of the ureter. Historically, TUU in children has been performed either to salvage a failed ureteral reimplantation or in conjunction with cutaneous ureterostomy for urinary diversion (4,5,6). Because TUU requires only one ureter for reimplantation, this procedure was commonly employed in the 1980s for urinary undiversion of conduits or in the construction of continent urinary reservoirs (3,7). In the majority of these cases, TUU was used simultaneously with reimplantation of the recipient ureter, many of which required tapering or tailoring frequently with a psoas hitch and/or bladder augmentation. TUU has also been used as an adjunct to reimplant procedures complicated by an abnormal bladder, which precludes reimplantation of more than one ureter, or as a salvage procedure for failed ureteral reimplantation surgery (3). More recently, indications for TUU have been broadened to allow for harvesting the distal donor ureter to construct a continent ureteral conduit for clean intermittent catheterization or for unilateral ureterocystoplasty in cases where there is sufficient ureteral dilatation (2).
Ureteral reconstruction with TUU may not be possible if there is insufficient donor ureter (approximately one-half the original length) for a tension-free anastomosis. Any disease process that has the potential to affect contralateral renal function or drainage is also a contraindication, such as retroperitoneal fibrosis, high-dose radiation therapy, calculus disease, recurrent pyelonephritis, and urothelial malignancy. Although size disparity between ureters has been regarded as a relative contraindication in the past, successful TUU has been accomplished by use of a longer vertical ureterotomy in the recipient ureter to accommodate a larger-caliber donor ureter (3,5,7).
Other procedures to be considered in lieu of TUU include ureteroneocystostomy with a psoas hitch or Boari flap, nephropexy to allow ureteroneocystostomy or ureteroureterostomy, ileal substitution, and autotransplantation. Other alternatives to TUU include mitigating or temporizing procedures such as cutaneous ureterostomy, pyelostomy, nephrostomy drainage, and ureteral stenting. Nephrectomy should also be considered in cases of marginal donor renal function.
The patient is placed supine with such options as kidney rest elevation, retroflexion of the surgical bed, and Trendelenburg positioning to enhance retroperitoneal exposure. A midline vertical incision is usually made in the abdomen, extending from just above the umbilicus to the pubic symphysis. However, in cases of distal TUU following a failed reimplantation, a Pfannenstiel incision may be sufficient. A choice of exposure approaches is then available.
Wide transperitoneal exposure is indicated in cases that require complex adjunct procedures such as tapered reimplantation of the recipient ureter or bladder augmentation as well as when there is a long segment of diseased distal donor ureter. This approach would also be preferred when a high TUU is necessary for the distal donor ureter to be used as a continent catheterizable channel or for augmentation of the bladder.
The bowel is packed and retracted superiorly to allow for further dissection. Once the ureters have been visualized as they pass over the iliac vessels, two options for opening the retroperitoneum have been described (8): (a) two 5-cm vertical incisions may be made over the ureters where they cross the iliac vessels, creating a window on each side (Fig. 87.1), and (b) wider retroperitoneal exposure can be achieved through a single curved incision that opens the retroperitoneum from over the left distal ureter, extending across the midline along the small bowel mesentery and cecum and up the right side along the line of Toldt (Fig. 87.2). This technique allows for more extensive mobilization of the bowel in an upward direction.