title: Flexible ureteroscopically assisted percutaneous renal access.
abstract: OBJECTIVE
  To combine retrograde flexible ureteroscopic techniques with a simultaneous percutaneous puncture to gain precise antegrade renal access in selected patients.
  
  
  METHODS
  Patients with minimally dilated collecting systems and complex stone burdens (including caliceal diverticular calculi) underwent adjunctive flexible ureteroscopy in an attempt to expedite percutaneous renal access. This combined retrograde and antegrade approach was also used in treating obese patients and those in whom prior attempts at percutaneous renal access had failed. The prone split-leg position and flexible retrograde ureteroscopy were employed. The exact calyx for percutaneous puncture was selected under direct vision using an actively deflectable, flexible ureteroscope. Access to narrow infundibula and caliceal diverticula was facilitated by employing injectable guidewires as well as small-diameter balloon dilators passed through the working channel of the flexible endoscope. A fluroscopically guided percutaneous puncture was then performed. The tip of the intrusive needle was visualized both fluoroscopically and endoscopically. An antegrade guidewire was advanced through a ureteroscopically positioned snare and withdrawn out the urethra. With this through-and-through guidewire access, standard percutaneous tract dilation and nephroscopic lithotripsy were performed expeditiously.
  
  
  RESULTS
  Seven patients with renal disease or body habitus that made precise percutaneous access difficult underwent adjunctive retrograde flexible ureteroscopy. One patient had a large perinephric hematoma from previous attempts at nephrostomy placement. The other six patients presented with: tightly branched staghorn calculi (three patients) and lateral/anterior caliceal diverticular calculi (three patients). Four patients were morbidly obese (240-320 lb), which also complicated antegrade access. Percutaneous renal access was obtained in < 30 min in all cases.
  
  
  CONCLUSIONS
  A precise percutaneous puncture into a complex collecting system and establishing a through-and-through safety guidewire can be facilitated with simultaneous retrograde flexible ureteroscopic techniques.
authors.affiliation: Division of Urology, Loma Linda University, California, USA.
authors.forename: M
authors.initials: M
authors.lastname: Grasso
authors.forename: G
authors.initials: G
authors.lastname: Lang
authors.forename: F C
authors.initials: FC
authors.lastname: Taylor
mesh_terms: D002404:Catheterization / Q000295:instrumentation; D004240:Diverticulum / Q000601:surgery; D004564:Electrocoagulation; D004867:Equipment Design; D005471:Fluoroscopy; D006406:Hematoma / Q000209:etiology; D006801:Humans; D007669:Kidney Calculi / Q000601:surgery*; D007670:Kidney Calices / Q000601:surgery; D007674:Kidney Diseases / Q000601:surgery; D008096:Lithotripsy / Q000379:methods; D009403:Nephrostomy, Percutaneous / Q000009:adverse effects / Q000295:instrumentation / Q000379:methods*; D009765:Obesity / Q000150:complications; D009767:Obesity, Morbid / Q000150:complications; D018583:Pliability; D015641:Radiography, Interventional; D012449:Safety; D013997:Time Factors; D020709:Ureteroscopes; D018666:Ureteroscopy / Q000379:methods*