Ureteral obstruction resulting from malignancy or recurrent benign disease is sometimes an extremely challenging situation for the urologist. They may result from a wide range of conditions and each may respond differently to different treatment alternatives.
- Etiology of Ureteral Obstruction
Iatrogenic – ureteroscopy, anastomosis in diversions, radiation therapy, laparoscopic or open repair
Non-Iatrogenic – Inflammation of ureteral wall due to calculus, TB, Schistomiazis – Congenital UPJ, UVJ
Malignant – TCC of ureter
Iatrogenic – ligation of ureter, severe thermal injury
Non-Iatrogenic – Retroperitoneal Fibrosis
Malignant – Primary or metastatic tumors compressing ureter
Percutaneous nephrostomy (PN), polymeric ureteral stents, and metal mesh stents are used with variable success rates for long-term relief of upper urinary tract obstruction.. The experience of our Unit is that patients with long standing malignant extrinsic ureteral obstruction are better treated with metallic stents. By minimizing the need for frequent stent changes, Quality of life (QoL)of patients is positively affected. The Resonance metallic ureteral stent (Cook Medical, Bloomington, Indiana, USA) has been introduced as a temporary drainage solution (up to 12 mo) for extrinsic ureteral obstruction.
Metallic Resonance Stent
These stents may be placed in an antegrade or retrograde fashion, depending on the individual characteristics of the patient. Usually, patients with long strictures or strictures of the mid to lower ureter are treated with antegrade stent placement. For the antegrade approach, standard PN is performed. Antegrade nephrostomogram follows to define the ureteral anatomy and the exact length and position of the stricture. The stenosed segment is then passed with the use of a 0.035-in guidewire. Dilatation of the stricture with use of a high-pressure balloon catheter (8–10 mm diameter) follows if the stricture is not wide enough to accommodate the introducer sheath before stent insertion. A coaxial system of catheter and sheath is then passed over the wire, including an inner 5F ureteral catheter and an outer 9F introducer sheath. The guidewire and the inner ureteral catheter are then removed, leaving only the tip of the outer sheath in the bladder, and the Resonance stent is pushed through the introducer sheath into the bladder using a plastic pusher at the proximal end. When the distal curl forms in the bladder, it is wise to resist pushing the proximal end of the stent too far, as there is no retrieval thread or mechanism with this deployment kit. When the proximal end is in place within the collecting system, the introducer sheath is removed over the pusher while holding the pusher in position. When the introducer sheath reached the marked site on the pusher, only the proximal pigtail is left inside the sheath. Further removal of the sheath over the pusher allows the formation of the final pigtail in the collecting system.
For retrograde stent insertion, with the patient under local or light anesthesia, a similar technique is used, taking care to avoid pushing the proximal end of the stent too far into the ureter. Resonance stent exchange is performed by insertion of a hydrophilic guidewire up to the kidney, parallel to the stent before stent removal. In the case of failure to pass the wire, the stent is removed and standard stent insertion is repeated as described above.
Retrograde insertion of Resonance stent
(Video courtesy of Cook Medical Inc.)
In the treatment of extrinsic malignant ureteral obstruction, placement of a Resonance stent has been demonstrated by our Unit and others as an indicated solution. Relative indications for similar stent use are in case of benign obstructive disease, such as lithiasis or ureteroilial anastomosis strictures. Benign intrinsic proliferative obstructive disease (occluded metal mesh stents in ureteroileal anastomosis) is probably a contraindication for Resonance stent insertion.
- Benign extrinsic obstruction of the ureter
Another challenging situation is the management of benign extrinsic obstruction of the ureter, as could occur with inadvertent ligation of the ureter or due to thermal damage during operations. This may be seen introperatively or detected at a later time. If seen during the operation, immediate repair is recommended. If the injury is detected at a later point, balloon dilation is recommended as a first step to resolving the resulting stricture.
Ureter trapped with suture
Balloon dilation of stricture
Further readings for management of malignant ureteral obstruction:
Ureteral metal stents: 10-year experience with malignant ureteral obstruction treatment.
Liatsikos EN, Karnabatidis D, Katsanos K, Kallidonis P, Katsakiori P, Kagadis GC, Christeas N, Papathanassiou Z, Perimenis P, Siablis D.
J Urol. 2009 Dec;182(6):2613-7.
Ureteral obstruction: is the full metallic double-pigtail stent the way to go?
Liatsikos E, Kallidonis P, Kyriazis I, Constantinidis C, Hendlin K, Stolzenburg JU, Karnabatidis D, Siablis D.
Eur Urol. 2010 Mar;57(3):480-6.
Metal stents for the management of malignant ureteral obstruction.
Liatsikos EN, Karnabatidis D, Katsanos K, Kallidonis P, Constantinides C, Perimenis P, Stolzenburg JU, Siablis D.
J Endourol. 2008 Sep;22(9):2099-100
Clinical experience with ureteral metal stents.
Al Aown A, Iason K, Panagiotis K, Liatsikos EN.
Indian J Urol. 2010 Oct;26(4):474-9.
Further readings for the management of beningn extrinsic ureteral obstruction:
Ureteral injuries during gynecologic surgery: treatment with a minimally invasive approach.
Liatsikos EN, Karnabatidis D, Katsanos K, Kraniotis P, Kagadis GC, Constantinides C, Assimakopoulos K, Voudoukis T, Athanasopoulos A, Perimenis P, Nikiforidis G, Siablis D.
J Endourol. 2006 Dec;20(12):1062-7.