Percutaenous nephrostomy salvage and tube exchange are two procedures undertaken in those with long term nephrostomies. These patients are often either unsuitable or do not wish to have ureteric stenting to relieve their urinary tract obstruction.
Nephrostomy salvage is undertaken in those in who an existing nephrostomy becomes partially or completely dislodged. The rate of tube dislodgement is ~20% after a few months 2.
The patient presents with either the tube completely out or with a history of poor or no urine output. In those who have had the tube in place for sometime (> 4 weeks) a tract may remain open for a period of time (typically up to 24 hours), through which a new tube may be placed.
If the nephrostomy is completely dislodged, a plastic dilator may be placed in the track and a tractogram performed to illustrate if the track remains patent into the renal collecting system. A hydrophilic wire may then be used to enter the collecting system. A plastic dilator may then be passed over the wire, enabling exchange with a stiff wire. A new catheter can then be placed over the wire, avoiding a new procedure and new renal puncture.
Nephrostomy tube exchange
Tube exchange is performed typically every three months to prevent tube obstruction from encrustation 2. Encrustration can also cause difficulties with tube removal if left for a longer period.
A nephrostogram is performed to check the catheter position. A stiff wire is passed into the neprostomy upto, but not into, the pigtail. The catheter is gently remove over the wire, with the wire left in the collecting system. A new catheter is then placed over the wire.
There are reports of up to 17% of patients acquiring a bacteraemia after routine tube exchange, but it is considered low risk, and many centres do not give prophylactic antibiotics prior to the procedure 1.
- 1. Cronan JJ, Horn DL, Marcello A et-al. Antibiotics and nephrostomy tube care: preliminary observations. Part II. Bacteremia. Radiology. 1989;172 (3 Pt 2): 1043-5. Pubmed citation
- 2. Dagli M, Ramchandani P. Percutaneous nephrostomy: technical aspects and indications. Semin Intervent Radiol. 2011;28 (04): 424-37. doi:10.1055/s-0031-1296085 - Free text at pubmed - Pubmed citation
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