Percutaneous nephrostomy

By MAAJID MOHI UD DIN MALIK Radiology Hub -February 16, 2023

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Percutaneous nephrostomy is a technique in which percutaneous access to the kidney is achieved under radiological guidance. The access is then often maintained with the use of an indwelling catheter.

Indications

Percutaneous nephrostomy is usually reserved for when retrograde approaches are unsuccessful or difficult. Clinical settings include: Urinary tract obstruction
Urinary diversion (e.g. Ureteric injury; urine leak
Access for percutaneous procedures (e.g. Stone treatment; Antegrade ureteric stenting)
Diagnostic testing (e.g. Antegrade pyelography, Whitaker test)

Contraindications Absolute contraindications

· Usually none

Relative contraindications

Uncorrectable bleeding diathesis (abnormal coagulation indices)
Uncooperative patient
Severe respiratory disease

Procedure

Pre-procedure evaluation

Review all available imaging to confirm the indication for the procedure and assess renal anatomy and establish a safe access route to the kidney
Check full blood count and coagulation profile to assess the risk of haemorrhage
Obtain informed consent for the procedure
Obtain good peripheral IV access
Administer broad-spectrum IV antibiotics 1-4 hours prior to the procedure, if needed; septic patients are often already on parenteral antibiotics

Positioning

The procedure is performed with the patient in the prone, prone oblique or lateral position, depending on clinical circumstances and patient comfort. Regular monitoring of the vital signs by a suitably trained staff member is recommended during the procedure. Clean skin with an antiseptic solution and drape to maintain sterility for the procedure.

Equipment

Ultrasound or fluoroscopy guidance
Local anaesthesia with 1% or 2% lidocaine
18-gauge puncture needle, an alternative would be to use a micropuncture set with a 21- or 22-gauge needle
0.035-inch stiff guide wire (an 0.018 guide wire is also used with a micropuncture set)
Water-soluble contrast media
Dilators ranging from 7-9 French
Pigtail drain (typically 8 French)

Technique

Two common techniques exist. The choice of technique depends on both operator and patient factors. One method utilizes a two- or three-part puncture needle and the other a micro-puncture kit. Using an aseptic technique and following infiltration of a local anaesthetic agent, the calyx (usually posterior calyx at the mid or lower pole) is punctured with an 18-gauge, two-part needle under ultrasound guidance. In the presence of renal tract obstruction, urine drains freely on the removal of the stylet from the needle.

A small volume of water-soluble contrast material can be injected to confirm the correct needle position using fluoroscopy. A 0.035 guide wire is used to exchange the needle for a dilator and typically an 8 French pigtail drain is placed within the renal pelvis over the guide wire. On occasion, a 6F or 12F catheter may be used, on an individual case basis. A urine sample can be sent off to the laboratory for microbiological studies. The catheter is left to drain freely.

Postprocedural care

Bed rest (typically 2-4 hours) with regular monitoring of vital signs and provision of adequate analgesia is routinely indicated in the first few hours following the procedure. Fluid balance is regularly monitored, particularly in cases of urinary tract obstruction. Indwelling nephrostomy catheters are usually exchanged every three months.

It is essentially normal for the urine to be partly blood-stained for the first 48- 72 hours.

The patient should take great care with the nephrostomy tube, to avoid malpositioning, despite the internal pigtail of the locked drain, skin anchoring stitch and adhesive plaster. Slippage is not uncommon but if the alerted medical staff is early, nephrostomy salvage can be performed without re-puncture.