UPJ Obstruction in the Adult Population: Are Crossing Vessels Significant?

Abstract

Ureteropelvic junction (UPJ) obstruction describes various causes of impaired drainage at the UPJ. Regardless of the cause, the end result is the same: impedance in the normal flow of urine from the renal pelvis into the proximal ureter, resulting in caliectasis and hydronephrosis. This may lead to progressive deterioration of renal function and, thus, often requires intervention to relieve the obstruction and restore the normal flow of urine. Defining the pertinent anatomy, the degree of obstruction, and differential renal function is key to determining whether and when intervention is necessary.

Figure 1

Ureteral folds noted below a hydronephrotic kidney. (A) Proximal ureteral folds are seen obstructing the ureteropelvic junction on the retrograde ureteropyelogram. (B) Corresponding intraluminal sonographic image defines a plexus of veins arising from the gonadal vein, creating this ureteral pattern of valvular-like folds. (Used with permission from Gitlin J, Grasso M.39)

Figure 2

Annular stricture causing a ureteropelvic junction (UPJ) obstruction in a 40-year-old man with new symptoms of renal colic. (A) The short, annular nature of the obstructing segment (with a guide wire passing through it) is observed on a retrograde ureteropyelogram. (B) An annular-like ureteral stricture, very similar to the more common urethral stricture, is seen on endoscopy. (C) Endoscopic view defines a safety guide wire through the strictured segment that is no more than 2 mm in diameter. (D, E) Seen on endoscopy, a posterolateral incision opens the strictured UPJ. More than 3 years following surgery, this patient has normal renal function and drainage, confirmed on serial nuclear medicine renal scans.

Figure 3

Three-dimensional reconstruction of a high-insertion ureteropelvic junction (UPJ) obstruction. The center of the image corresponds to the intraluminal sonographic probe, which is cylindric. From left to right, large anterior medial crossing vessels are noted. In addition, a common wall, composed of the renal pelvis and proximal ureter, is acting as a flap valve. This patient had undergone a previous endopyelotomy, using the Acucise device, in which a lateral incision unsuccessfully opened the UPJ. In light of renal rotation, this high insertion was incised in a purely posterior direction, which facilitated funneling at the UPJ, relieving the obstruction. (Used with permission from Giddens JL, Grasso M. J Urol. 2000.17)

Figure 4

Intraluminal sonographic image of the ureteropelvic junction (UPJ) defining an associated large posterior crossing vessel. The patient’s contralateral kidney had been removed for poor function secondary to a UPJ obstruction. This patient underwent an antegrade endopyelotomy in which a lateral incision was performed, avoiding this vessel. She subsequently re-presented with obstruction 1 year postoperatively. At open pyeloplasty, the large posterior vein was confirmed.

Figure 5

A 32-year-old woman presented with moderate azotemia and bilateral hydronephrosis. Right retrograde ureteropyelography demonstrated a redundant proximal ureter and ureteropelvic junction (UPJ) obstruction. (A) Intraluminal sonography defined a common wall posteriorly and medially between the proximal ureter and renal pelvis. An incision was made in the posterior medial segment. (B) An intravenous pyelogram (6 months after treatment for the right side) showed the right kidney draining promptly with funneling at the UPJ. The left kidney continued to drain poorly and, at this time, the patient experienced episodic colic. (C) A retrograde ureteropyelogram on the left side defined a similar anatomic variant; at this time, a posterior medial incision was made to divide a common wall. (D) Intravenous pyelography, performed 6 months thereafter, defines prompt symmetric renal function and immediate drainage bilaterally.