Nephrostomy

[2] It is an interventional radiology/surgical procedure in which the renal pelvis is punctured whilst using imaging as guidance.

Images are obtained once an antegrade pyelogram (an injection of contrast), with a fine needle, has been performed.

A nephrostomy is performed whenever a blockage keeps urine from passing from the kidneys, through the ureter and into the urinary bladder.

[6] Percutaneous nephrostomy is also used to provide access for chemotherapy/antibiotic/antifungal therapy, antegrade urethral stent placement, stone retrieval, and endopyelotomy (endoscopic surgery for the enlargement of the junction of renal pelvis and ureter).

An area is selected below the 12th rib, bounded laterally by the posterior axillary line and the muscles of the spine and from below by the pelvic bone.

Dye injection is avoided in case of turbid urine to prevent the spread of infection to other parts of the urinary system.

[6] Then, a guidewire is inserted into the through the needle and parked within the upper renal calyx or within the ureter under fluoroscopy guidance.

(A) Renal ultrasonograph of percutaneous nephrostomy tube placed through a calyx in the lower pole of a kidney with hydronephrosis. (B) The pigtail catheter is placed in the dilated calyx. The tube in (A) and the pigtail in (B) are marked with white arrows. [ 1 ]
Various settings of a 6 French pigtail catheter with locking string, obturator (also called stiffening cannula ) and puncture needle.
A . Overview
B . Both puncture needle and obturator engaged, allowing for direct insertion.
C . Puncture needle retracted. Obturator engaged. Used for example in steady advancement of the catheter on a guidewire previously inserted into the renal pelvis through a thin needle.
D . Both obturator and puncture needle retracted, when the catheter is in the renal pelvis.
E . Locking string is pulled (bottom center) and then wrapped and attach to the superficial end of the catheter.