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 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.
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.
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.