Percutaneous Nephrostomy

Percutaneous nephrostomy is an interventional radiological procedure used to establish an artificial pathway for urine drainage in cases of obstructed urinary flow from the kidneys to the bladder. This technique involves the percutaneous insertion of a specialized catheter directly into the renal collecting system, specifically accessing the renal pelvis or calyces. Can be performed on native (non-transplanted) or transplanted kidneys.

Under image guidance, a needle is first advanced through the skin and into the targeted renal collecting system. This needle serves as a guide for subsequent dilation of the tract. A percutaneous nephrostomy can be performed to place an internal-external drain to assist in decompressing the affected kidney, which is connected to a drainage bag (outside of the patient). Further intervention can involve access the distal ureters into the bladder and identifying the source of blockage/s or stenosis. Ureteric angioplasty can be used to perform low pressure dilatation of the stenotic ureter tract. Additional intervention can then progress with the insertion of a ureteric stent from the kidney to the bladder.

Percutaneous nephrostomy is performed for various reasons, such as relieving urinary obstruction caused by conditions like kidney stones, tumors, or strictures. It is also employed in cases of severe infection or injury that impairs normal urine flow. By providing an alternative route for urine to bypass the obstruction, percutaneous nephrostomy helps relieve the pressure on the kidneys, preventing potential damage and promoting renal function.

A&I Protocol

Patient is usually positioned prone on the angiography table, with pillow support under the chest, pelvis and feet, and both arms comfortably supported above the head.

Seldinger technique is used to gain access into the affected kidney using ultrasound guidance and a 21G diagnostic needle and supporting 0.038"guidewire.
A luer-slip syringe and extension system is connected when urine exits the hub of the needle.
X-ray using the angiography system is used to confirm the position of the needle within the calyces and then using contrast media injection with fluoroscopy.
The contrast media is imaged from the kidney, down the ureters and towards the bladder, and can determine the site/s of stenosis (usually from renal calculi or external compression).
A 6F 23cm sheath is introduced over a long 180 cm guidewire.
For a percutaneous nephrostomy, the procedure is completed by inserting a multipurpose drainage catheter, usually 6F-8F in size. This is connected to an external drainage bag.
Further intervention can be performed with ureteric angioplasty, by measuring the diameter of the ureter and ballooning the stenosis. Access through the stenosis is done using a guidewire or hydrophilic guidewire and a bern-shaped catheter. Once the stenosis is crossed, a low pressure angioplasty balloon is inflated.
Additional intervention can involve the insertion of a 6F (x24cm) ureteric stent which is deployed through the 6F sheath and is positioned from the kidney to the bladder.
Following the procedure, the drainage bag is secured from the multipurpose drainage catheter and is allowed to free-flow and decompress the affected kidney.

Left nephrogram following percutaneous access of the kidney. Progress to internal-external drain or angioplasty +/- stent and internal-external drain.

References

Saad WEA, Moorthy M, Ginat D. Percutaneous nephrostomy: native and transplanted kidneys. Tech Vasc Interv Radiol. 2009 Sep;12(3):172–92.
Dyer RB, Regan JD, Kavanagh PV, Khatod EG, Chen MY, Zagoria RJ. Percutaneous nephrostomy with extensions of the technique: step by step. Radiographics. 2002;22(3):503–25.
Ho Won J, Jin Yang W, Hoon Shin J, Woo Kim J, Ho Chu H, Min Lee S, et al. Percutaneous nephrostomy for nondilated renal collecting system with ultrasound and fluoroscopic guidance: The results of a 10-year experience. Diagn Interv Radiol. 2022 May;28(3):244–8.
Adamo R, Saad WEA, Brown DB. Percutaneous ureteral interventions. Tech Vasc Interv Radiol. 2009 Sep;12(3):205–15.
Canales BK, Hendlin K, Braasch M, Antolak C, Reddy A, Odeh B, et al. Percutaneous nephrostomy catheters: drainage flow and retention strength. Urology. 2005 Aug;66(2):261–5.