PERCUTANEOUS NEPHROLITHOTOMY PCNL

Percutaneous nephrolithotomy (PCNL)
Complications of PCNL and their management
Bleeding
Some bleeding is inevitable, but that severe enough to threaten life is uncommon. In most cases it is venous in origin and stops following placement of a nephrostomy tube (which compresses bleeding veins in the track). If bleeding persists, clamp the tube for 10 min. If bleeding continues despite this, arrange urgent angiography, looking for an arteriovenous fistula or pseudoaneurysm, both of which will require selective renal artery embolization (required in 1% of PCNLs33) or open exposure of kidney to control bleeding by suture ligation, partial nephrectomy, or nephrectomy.

Septicaemia
Occurs in 1 -2% of cases. Incidence is reduced by prophylactic antibiotics. Track damage. Essentially minimal. Cortical loss from track is estimated to be <0.2% of total renal cortex in animal studies.

Colonic perforation
The colon is usually lateral or anterolateral to the kidney and is therefore not usually at risk of injury unless a very lateral approach is made. The colon is retrorenal in 2% of individuals (more commonly in thin females with little retroperitoneal fat31). The perforation usually occurs in an extraperitoneal part of the colon, and is managed by JJ stent placement and withdrawal of the nephrostomy tube into the lumen of the colon to encourage drainage of bowel contents away from that of the urine, thereby encouraging healing without development of a fistula between bowel and kidney. A radiological contrast study a week or so later confirms that the colon has healed and that there is no leak of contrast from the bowel into the renal collecting system.

Damage to the liver or spleen
Very rare in the absence of splenomegaly or hepatomegaly.

Damage to the lung and pleura leading to pneumomothorax or pleural effusion
Can occur with supra-12th rib puncture.

Nephrocutaneous fistula
When the nephrostomy tube is removed from the kidney, a few days after surgery, the 1cm incision usually closes within 2 or so. Occasionally, urine continues to drain percutaneously for a few days and a small  stoma bag must be worn. In the majority of such cases the urine leak will stop spontaneously, but if it fails to do so after a week or so, place a JJ stent to encourage antegrade drainage of urine.

Outcomes
For small stones, the stone-free rate after PCNL is in the order of 90 -95%. For staghorn stones, the stone-free rate of PCNL, when combined with post-op ESWL for residual stone fragments, is in the order of 80 -85%.

Serious or frequently occurring complications of PCNL
Common
- Temporary insertion of a bladder catheter and ureteric stent/kidney tube needing later removal
- Transient haematuria
- Transient temperature

Occasional
- More than one puncture site may be required
- No guarantee of removal of all stones and need for further operations
- Recurrence of stones

Rare
- Severe kidney bleeding requiring transfusion, embolization, or, at last resort, surgical removal of kidney
- Damage to lung, bowel, spleen, liver requiring surgical intervention
- Kidney damage or infection needing further treatment
- Over absorption of irrigating fluids into blood system causing strain on heart function

Alternative treatment External shock wave treatments, open surgical removal of stones, observation.

Indications :
- Stones >3cm in diameter
- Stones that have failed ESWL and/or an attempt at flexible ureteroscopy and laser treatment
- Staghorn calculi

Pre-operative preparation
- CT scan to assist planning the track position and to identify a retrorenal colon31
- Stop aspirin 10 days prior to surgery
- Culture urine (so appropriate antibiotic prophylaxis can be given)
- Cross-match 2 units of blood
- Start IV antibiotics the afternoon before surgery to reduce the chance of septicaemia (many of the stones treated by PCNL are infection stones). If urine is culture -ve, use 1.5g IV cefuroxime TDS and once daily IV gentamicin (3mg/kg). Routine antibiotic prophylaxis also reduces the incidence of post-OP UTI.