Reconstruction of the ureter is required if a segment has been removed during the treatment of trauma, stricture, stenosis, or other regional disease. Several different techniques are available, with the optimal choice depending on both the location and length of the excised segment.
DISTAL URETERAL DEFECTS
Ureteroneocystostomy is appropriate for small defects (<5 cm) in the distal ureter. It consists of reimplantation of the proximal ureteral end directly into the bladder (see Plate 10-35). The reimplantation should be performed with antireﬂux technique whenever possible; however, if the ureter end is not long enough to pass through a new submucosal tunnel, a reﬂuxing oriﬁce may be created instead.
A psoas hitch can be used to bridge a longer defect (up to 10 cm) in the distal ureter. This procedure involves mobilization of the entire bladder. The contralateral superior umbilical artery, and in some cases the entire contralateral bladder pedicle, may be ligated to permit such mobilization. An anterior cystotomy is performed, and the dome of the bladder is sutured to the psoas muscle on the side of the ureteral injury. Care must be taken not to injure the femoral or genitofemoral nerves. The ureteral end is then reimplanted into the bladder using antireﬂux technique when possible.
A Boari ﬂap is reserved for more extensive defects in the mid and distal ureter (10 to 15 cm) that cannot be corrected with a psoas hitch. The bladder is mobilized as in a psoas hitch, and then a full-thickness ﬂap is created from the bladder wall in the territory of the superior vesical artery or one of its branches. The width of the ﬂap base should be at least three times greater than the length of the ﬂap to ensure an adequate vascular supply. The ﬂap is then tubularized around a small-diameter catheter and anastomosed to the proximal end of the ureter in end-to-end fashion. The distal aspect of the reconstructed tube is sutured to the psoas tendon to prevent migration of the bladder and ensure a tension-free reconstruction. The patient will experience a signiﬁcant reduction in bladder capacity following this procedure.
UPPER OR MIDURETERAL DEFECTS
A ureteroureterostomy is typically performed to bridge short defects in the midureter. It consists of anastomosis of the two free ends of a ureter after a short segment (2 to 3 cm) has been excised. The proximal and distal ureteral ends are spatulated and anastomosed over a stent in a water-tight and tension-free fashion.
Transureterostomy may be performed for larger defects in the midureter. In this procedure, the free proximal end of the ureter is anastomosed to the contralateral ureter in end-to-side fashion. The major drawback of the procedure, however, is that the crossed ureter becomes very difﬁcult to access from an endoscopic approach. There-fore, it is avoided in patients with a history of nephrolithiasis or urothelial carcinoma, in whom ureteroscopic access is often desired. In addition, the procedure requires exposure and intentional injury of the contralateral ureter, both of which can cause unexpected complications.
A renal descensus can help bridge large upper ureteral defects. Renal descensus requires entry into the renal fascia and complete mobilization of the kidney until its only attachments are the vascular pedicle and ureter. The kidney is rotated medially and inferiorly, then sutured to the retroperitoneal musculature. A ureteroureterostomy can subsequently be performed.
An ileal ureter, which introduces the bowel into the urinary tract, is used for wide ureteral defects or other surgically complex cases that require more drastic reconstruction efforts. Patients with baseline renal insufﬁciency (serum creatinine ≥2), liver dysfunction, bladder dysfunction, radiation enteritis, or inﬂammatory bowel disease should not undergo this procedure. After the patient has undergone adequate bowel preparation and oral antibiotic treatment, a segment of ileum (located at least 15 cm from the ileocecal valve) is excluded with its vascular supply intact. The segment is then anastomosed to the renal pelvis and posterior wall of the bladder. It is important to maintain normal proximal-to-distal orientation of the ileal segment so that peristalsis occurs in the correct direction. The open ends of bowel created by the ileal resection are reanastomosed to restore continuity, and the mesenteric window is closed to prevent bowel strangulation.
Finally, autotransplantation may be employed as a last resort in the case of very large ureteral defects. In this procedure, the kidney is harvested as in a donor nephrectomy, then anastomosed to the patient’s own iliac vessels, as in a recipient operation.