URETERAL RECONSTRUCTION
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.
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| Plate 10-36 |
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.
