Percutaneous ultrasound guided endoscopic lavage of perinephric abscess – different, but not necessarily better
Reviewed by Hamid Abboudi

Perinephric abscess is an uncommon but serious form of urosepsis. It develops as a consequence of the extension of an infection outside of the parenchyma of the kidney in acute pyelonephritis, or more rarely from haematogeneous spread of an infection from a distant site. Most patients require some form of drainage of the abscess in addition to antibiotic therapy. The authors of this manuscript report their experience of using percutaneous ultrasonography guided endoscopic lavage of perinephric abscesses greater than 3cms. The technique described is similar to percutaneous nephrolithotomy (PCNL) access. Ultrasound (US) guided puncture of the abscess cavity was followed by serial dilation of the track to either 26F or 32F. Once the abscess cavity had been inspected via a nephroscope and purulent material was drained passively by irrigation, an ultrasonic lithotripter with a 9.9F ultrasound probe was used to actively clear the infection and break down loculations. An 18F or 21F percutaneous drainage tube was left in situ post procedure. Patients were followed up with serial US during their hospital admission and then at four to six weeks post discharge to look for any recurrence of collection. There were 37 patients (40 operations) retrospectively identified. Thirty-one procedures were performed under general anaesthesia, the remainder either spinal or local anaesthesia with sedation. The mean operative time was 49.4 minutes. Thirty-one patients had their percutaneous track dilated to 32F. Two patients required repeated drainage. The average postoperative drainage time was 8.35 days (3-21 days). The median postoperative hospital stay was 10 days (4-101 days). There was no mortality. The authors’ title ‘a better way’ may be slightly premature given these results. However, traditional percutaneous drainage can be limited by small size drainage catheters leading to suboptimal drainage and failure to deloculate the abscess. Therefore re-intervention rates may be higher than this novel technique. Further prospective studies would be helpful to compare this new approach to the current standard approach. 

A better way to manage perinephric abscesses: percutaneous ultrasonography-guided endoscopic lavage.
Ng C, Liong Y, Leong W, et al.
JOURNAL OF ENDOUROLOGY
2014;28:528-31.