Obstructive uropathy including ureteral obstruction from iatrogenic, neoplastic, or inflammatory causes
Urinary diversion
a. Urine leak
b. Vesicovaginal or vesicocolic fistula
Access for percutaneous intervention
a. Percutaneous nephrolithotomy
b. Tumor biopsy and/or ablation
c. Stricture dilation
Preoperative localization of the ureter
Before and after extracorporeal shock wave lithotripsy (ESWL)
Following a surgical procedure involving the ureter to maintain patency during healing
Contraindications
Uncorrectable coagulopathy—the risk of not performing drainage is weighed against the risk of bleeding (typical goal is INR < 2.0 and Plt > 50) and kidney loss. Specific to antegrade ureteral stents
Untreated bladder outlet obstruction
Untreated urinary tract infection
Spastic or noncompliant bladder
Bladder fistula
Nonnative bladder
Homework
When is stent preferred
Obstructive urolithiasis without pyonephrosis
Intrinsic ureteral obstruction
Patient preference and quality of life
Malignant ureteral obstruction (initial attempt):
When is PCN preferred
Pyonephrosis / infected obstructed kidney: per CIRSE standards, as larger-bore drainage is warranted and minimizes the risk of septic shock
Urosepsis with severe inflammation: demonstrated faster normalization of CRP and temperature recovery compared to retrograde stenting in patients with urosepsis
Extrinsic ureteral obstruction with high failure risk
Failed retrograde stent placement
Urinary diversion for leaks or fistulae
Brodels avascular plane - relatively hypovascular zone between anterior and posterior segmental arterial territories
Runs along posterolateral aspect of kidney
Important but perhaps overstated when it comes to PCN as technique usually relies on calyceal fornix puncture rather than targeting Brodel’s line
Ideally a posterior lower zone calyx should be targeted
Malecot or tulip type locking mechanism occupies less space and is useful for a very small renal pelvis or when a staghorn fills the renal pelvis