title: Superperc: A new technique in minimally-invasive percutaneous nephrolithotomy.
abstract: BACKGROUND
  Percutaneous nephrolithotomy (PCNL) has undergone significant changes in recent years in the quest for improving efficacy and reducing morbidity. Newer minimally-invasive modalities of PCNL such as mini-PCNL, ultra-mini PCNL, and micro-PCNL have evolved with advancement in optics and technology. However, with these newer advancements, migration of small fragments produced with laser lithotripsy remains a concern, which may result in incomplete stone clearance. We describe a new technique of PCNL termed "Superperc", that utilizes suction to remove all the fragments and maintain one-way flow.
  
  
  METHODS
  This was a prospective observational study involving 52 consecutive patients who underwent PCNL with the Superperc technique from April 2014 to June 2015. Surgery was performed using a pediatric ureteroscope used as a nephroscope and a specially designed sheath with a suction attachment. The Superperc uses a 10/12 F tract size, specially designed Superperc sheath (Shah Sheath) with suction mechanism and a pediatric ureteroscope (4.5/6 Fr, Richard Wolf) as nephroscope.
  
  
  RESULTS
  The mean age of the group was 41.8 years (range 6-84) with 33 males and 19 females. Mean stone size was 19.11 mm (range 10-37 mm) and mean operative time was 40.9 min (range 26-92 min). Twenty-seven renal units had upper calyceal puncture, whereas 12 had middle, 8 lower calyceal and 5 had two punctures. DJ stent was placed in 20 patients, whereas 32 patients were totally tubeless. Only three patients required a nephrostomy tube. The mean hemoglobin drop was 0.32 g with no blood transfusion. Postoperatively, three patients had a mild fever and one had transient hematuria. The stone clearance rate in our study was 96.15% and the mean hospital stay was 31.5 h (range 22-76 h).
  
  
  CONCLUSIONS
  Superperc is a new technique of minimally-invasive PCNL and can be successfully done with minimal modification in armamentarium, with the potential advantage of good stone clearance.
authors.affiliation: Department of Urology, Varun Kidney Hospital, Surat, Gujarat, India.
authors.forename: Kaushik
authors.initials: K
authors.lastname: Shah
authors.affiliation: Department of Urology, Global Rainbow Hospital, Agra, Uttar Pradesh, India.
authors.forename: Madhu Sudan
authors.initials: MS
authors.lastname: Agrawal
authors.affiliation: Department of Urology, Global Rainbow Hospital, Agra, Uttar Pradesh, India.
authors.forename: Dilip Kumar
authors.initials: DK
authors.lastname: Mishra