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Nephrostomy tubes (PCNs) and percutaneous access

• Indications: bypass obstruction, diagnostic studies, instill chemotherapy, postsurgical drainage
• Percutaneous access: safest via papillary approach due to lack of vessels, although some evidence that infundibular approach has no increased bleeding risk
• Anticoagulation: need to stop prior to access, although aspirin use does not seem to increase bleeding risk
• Ribs: entry above 11th rib has high risk for pleural injury, entry above 10th rib has high risk for lung injury
• Blind access: access via Grynfeltt lumbar triangle - borders are 12th rib, quadratus lumborus, transversus abdominis, and internal oblique, insert needle 3-4cm at 30degree cephalad angle
• Nephroureteral stent: consider if concern that tube will become dislodged with movement
• Options: cope loop (pigtail secured with string), council catheter placed over wire, Malecot catheter placed with straightener, or nephroureteral stent
• Complications: acute bleeding requiring transfusion (0.5-4%), delayed hemorrhage (< 1%), perforation, colon injury (0.1%), splenic/hepatic injury (less rare if access is above 10th rib), hydrothorax/pneumothorax (rare if access below 12th rib), urinothorax (2% if access above 12th rib, 6% if access above 11th rib)

Ureteral Stents

• Indications: infection and obstruction of upper tract, malignant obstruction
• Placement: fluoroscopically (marker over pubic symphysis), under direct visualization, or by feel (female only)
• Floated stent: distal stent tip pushed within ureteral orifice, can attempt removal with basket or ureteroscopic graspers, occasionally needs to be removed percutaneously
• Stent pain: manage discomfort with a-blockers, NSAIDs (preferred over opioids), and antimuscarinics
• Encrustation occurs in up to 13%, increased risk with diabetes, rUTI, renal failure, pregnancy, manage depending on severity and location of encrustation