Percutaneous nephrolithotomy (PCNL)
With this technique, a large bore tract (30Fr) is dilated over a guide wire passed from the loin, traversing the renal parenchyma and entering into the pelvicalyceal system via a renal papilla. A nephroscope is then passed down the tract and calculi are fragmented and removed. This is then followed by a period of post-operative nephrostomy drainage (1-2 days) and typically the patient is in hospital for 3-4 days. The wound is approximately 1cm in diameter and normal activities are rapidly resumed, although full contact sport should be avoided for 4-6 weeks.
The indications for PCNL are large renal stone burdens (i.e. ›2cm, ›1.5cm for lower pole), ESWL or flexible ureterorenoscopic failures and in the treatment of concurrent intrarenal pathology (i.e. pelviureteric junction obstruction, calyceal diverticulum). Over the past few years, there has been a resurgence of interest in this technique as the indications for ESWL become more tightly defined. The technique continues to evolve with present research concentrating on the role of smaller tracts (the so-called Miniperc) and “tubeless” post-operative management.
Post-operative discomfort is quite common, especially after intercostals punctures; however, this is usually well controlled with simple analgesia. Major complications include bleeding and sepsis. The incidence of transfusion requirement is between 1-2% and rarely radiological embolisation is required to treat life-threatening haemorrhage (‹0.5%). Transient post-operative pyrexia is common; however, gram-negative sepsis and signs of septicaemia are fortunately rare but can lead to a few days in the high dependency unit when it does occur. Whilst there is undoubtedly a loss of a small amount of renal function from this technique, this is not clinically significant and cannot be detected by present imaging modalities unless a complication arises. Indeed, the operation may involve more than one tract and is repeatable with no discernible reduction in renal function. Those patients who are anticoagulated should not undergo PCNL without haematological back up.