PYELOPLASTY AND ENDOPYELOTOMY
A pyeloplasty or endopyelotomy may be performed to treat an obstruction of the ureteropelvic junction (UPJ, see Plate 6-6). A pyeloplasty consists of surgical reconstruction of the UPJ, whereas endopyelotomy consists of intraluminal, endoscopic incision of the obstruction.
PYELOPLASTY
Pyeloplasty
remains the gold standard and may be per- formed using either open or
laparoscopic technique. It is especially appropriate for patients with large
stone burdens, strictures more than 2 cm long, marked renal pelvis dilation, or
radiographic evidence of a crossing vessel.
An open
pyeloplasty is typically performed from a retroperitoneal approach (see Plate
10-19), with an incision carried from the tip of the eleventh rib toward the
umbilicus. A laparoscopic pyeloplasty, with or without robot assistance, is
most often performed trans- peritoneally, using three or four abdominal
trocars.
Once the
renal fascia has been entered and the hilum accessed, the UPJ may be
reconstructed using various techniques. The most common is the Anderson-Hynes
dismembered pyeloplasty. The proximal part of the UPJ is transected, the UPJ
and proximal ureter are spatulated laterally, and reanastomosis is performed.
The dismembered technique not only treats the UPJ obstruction but also permits
transposition of crossing vessels. In addition, redundant renal pelvic tissue
may be excised.
In certain
situations, other reconstruction techniques may be employed. In the case of a
high insertion of the ureter, either a dismembered or a Foley Y-V plasty may be
performed. In the latter, a Y-shaped incision is made in the UPJ. The top of
the “Y” is made in the dependent aspect of the renal pelvis, while the stem of
the “Y” is carried across the inferior aspect of the UPJ. The incision is then
closed as a simple V-flap.
In patients
with long, atretic UPJ segments, a renal pelvis spiral flap repair may be
required. An elliptical incision is made on the anterior aspect of the renal
pelvis and UPJ. The apex of the flap, originally from the renal pelvis, is
rotated 180 degrees inferomedially and now constitutes the anterior UPJ. To
prevent flap ischemia, the flap length to width ratio should not exceed 3:1.
In cases of
repeat pyeloplasty, or when a patient has a very small intrarenal pelvis,
ureterocalycostomy is performed. A lower pole calyx is exposed and anastomosed
end-to-end to the spatulated proximal ureter.
Additional
repairs and flaps have been described using both the renal pelvis and the renal
capsule, but these are rarely indicated.
ENDOPYELOTOMY
An
endopyelotomy begins with direct visualization of the obstruction from either
from a retrograde approach (ureteroscopy, see page 10-33) or anterograde
approach (nephroscopy, see Plates 10-13 and 10-14). A safety wire is advanced
across the stricture, which is then incised using a knife, laser, or other
device. The incision is created in a lateral direction, so as to minimize
injury to crossing vessels, and
should extend through the ureteral
mucosa and muscle until periureteral fat is seen. In the case of a high
insertion of the ureter into the renal pelvis, an anterior or posterior
incision may be required to allow proper marsupialization of the proximal
ureter into the renal pelvis.
A ureteral
stent or percutaneous nephroureteral stent is placed to facilitate
postoperative drainage and can be removed after 4 to 6 weeks. If injury to a
crossing vessel is suggested by intraoperative hemorrhage or postoperative
hemodynamic instability, the patient should undergo emergent angiographic
evaluation and possible embolization.
FOLLOW-UP
One month
after the procedure, an ultrasound of the kidneys and bladder should be
performed. Three months after the procedure, after the stents have been
removed, diuretic renography should be performed to confirm the production and
unobstructed flow of urine through the affected upper tract.
Open
pyeloplasty has a long-term success rate of 95%, with comparable rates reported
in the laparoscopic and nascent robotic literature. Endoscopic repair appears
to be less successful, with failure occurring in up to one third of cases.
