Percutaneous nephrostomy

PERCUTANEOUS NEPHROSTOMY, Clinical Skills Lab

INTRODUCTION:

Percutaneous nephrostomy is an insertion of a tube into the pelvi-calyceal system to allow diversion of the urine output.  This can be  a life saving procedure when the urinary tract (usually the ureter) is obstructed with sepsis.  Putting a percutaneous nephrostomy would relieve the kidney failure as well as the underlying sepsis, both of which can be fatal. 

The common causes of ureteric obstruction include: obstruction by cancers e.g. cancer cervix, rectal cancers, metastatic disease to the retroperitoneal lymph nodes. 

Benign causes include ureteric strictures or fistulas, often iatrogenic, caused by the gynaecologists during surgery on the uterus.

Percutaneous nephrostomy is an expert procedure, usually done by the interventional radiologist or by the urologist. It is often done with the imaging by ultrasound and fluoroscopy. The pelvi-calyceal system should ideally be dilated to reduce the risk of injury to the kidney.  A suitably dilated calyx is punctured. This is usually the lower calyx to reduce the risk of injury to the pleura when the upper calyx is punctured.

Informed consent is important to get the patient’s cooperation and also to inform the family of the risk of the procedure including bleeding, injury to the nearby structures including the pleura and intestines.  The procedure is done after infiltration of the skin and tract with local anaesthesia. The dilated calyx is punctured with a percutaneous needle, usually an 18G puncture needle under ultrasound guide and tracking.  After the needle has entered the dilated calyx, urine is withdrawn and sent for bacterial culture.  A guide wire is introduced down the needle into the renal pelvis or  the upper ureter.  The tract is then dilated, usually 6 Fr, 8 Fr, 10 Fr serial dilators.  The percutaneous nephrostomy tube, usually 10 or 12 Fr is then inserted over the same guide wire into the pelvi-calyceal system to drain the urine. The percutaneous nephrostomy usually has a pigtail to reduce the risk of dislodgement from the pelvi-calyceal system.  The nephrostomy is also anchored with Silk sutures to the patient’s skin. The nephrostomy is then connected to a drainage urine bag.  Nephrostomy tubes can usually be left insitu for up to 6 months, although usually for much shorter. In the meantime, the underlying problems can be managed, e.g. radiotherapy for cancer of the cervix.

FOLLOW-UP:

If the urinary drainage is still required, the nephrostomy tube can be wired with a guide wire and if the guide wire can pass into the bladder, the nephrostomy tube can be changed to an indwelling ureteric stent. Again, this is done under fluoroscopy. 

Dr Clarence Lei Chang Moh, FRCS Urol

Consultant Urologist

email: clarencelei@gmail.com

10^th September 2013

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