title: The learning curve in minimally invasive percutaneous nephrolitholapaxy: a 1-year retrospective evaluation of a novice and an expert.
abstract: OBJECTIVE
  The aim of this study was to compare a novice surgeon with an expert surgeon independently performing minimally invasive percutaneous neprolitholapaxy (PCNL) excluding the influence of the expert in the learning curve.
  
  
  METHODS
  Clinical records of 84 patients (novice: n = 35; expert: n = 49) undergoing minimally invasive PCNL between 04/2007 and 04/2008 were retrospectively reviewed for the following parameters: drop in hemoglobin, operative and fluoroscopy time, length of hospital stay, stone-free rate and complication rate. Complications were graded according to the Clavien classification. Statistical analysis was carried out by student's t test (Chi-square test) with p < 0.05 considered significant.
  
  
  RESULTS
  The novice surgeon experienced longer median operative and fluoroscopy time, lower stone-free rate and higher re-treatment rate (all p < 0.005) but no longer length of hospital stay (p = 0.19) compared to the experienced surgeon. The novice showed a notable improvement in operating time (p = 0.0208). Altogether, 16 complications occurred in 84 minimally invasive PCNL (19.1%) with five patients (6.0%) encountering grade III complications. Four patients (8.2%) treated by the expert surgeon developed complications (all grade I/II) compared to 12 of the patients (34.3%) treated by the novice surgeon (p = 0.0265). All grade III complications occurred in the first 20 patients of the novice surgeon group.
  
  
  CONCLUSIONS
  Despite longer operating time and a lower initial stone-free rate, the novice showed a significant improvement with growing experience and a low rate of higher grade (≥IIIa) complications. This demonstrates that the concept of minimally invasive PCNL can also be learned by urologists who do not have the support of an experienced colleague without endangering patient safety.
authors.affiliation: Department of Urology, University Hospital Tuebingen, Hoppe-Seyler-Str. 3, 72076, Tübingen, Germany. david.schilling@med.uni-tuebingen.de
authors.forename: David
authors.initials: D
authors.lastname: Schilling
authors.forename: Georgios
authors.initials: G
authors.lastname: Gakis
authors.forename: Ute
authors.initials: U
authors.lastname: Walcher
authors.forename: Arnulf
authors.initials: A
authors.lastname: Stenzl
authors.forename: Udo
authors.initials: U
authors.lastname: Nagele
mesh_terms: D000328:Adult; D000368:Aged; D002983:Clinical Competence; D005260:Female; D005471:Fluoroscopy; D006801:Humans; D015994:Incidence; D007669:Kidney Calculi / Q000601:surgery*; D059032:Learning Curve; D007902:Length of Stay; D008137:Longitudinal Studies; D008297:Male; D008875:Middle Aged; D019060:Minimally Invasive Surgical Procedures / Q000193:education / Q000379:methods*; D009403:Nephrostomy, Percutaneous / Q000379:methods*; D011183:Postoperative Complications / Q000453:epidemiology; D012189:Retrospective Studies; D013997:Time Factors; D016896:Treatment Outcome
references.citation: Urology. 2010 Jan;75(1):51-5
references.pmid: 19781744
references.citation: J Endourol. 2005 Apr;19(3):279-82
references.pmid: 15865512
references.citation: Eur Urol. 2007 Jul;52(1):206-11
references.pmid: 17229522
references.citation: J Endourol. 2008 Sep;22(9):1851-3; discussion 1857
references.pmid: 18811465
references.citation: Eur Urol. 2007 Apr;51(4):899-906; discussion 906
references.pmid: 17095141
references.citation: Urology. 2006 Sep;68(3):489-93; discussion 493-4
references.pmid: 16979734
references.citation: Aktuelle Urol. 2009 Nov;40(6):351-4
references.pmid: 19795340
references.citation: Eur Urol. 2008 Jan;53(1):184-90
references.pmid: 17651892
references.citation: J Endourol. 2007 Apr;21(4):393-6
references.pmid: 17451328
references.citation: J Endourol. 2007 Sep;21(9):1113-6
references.pmid: 17941796
references.citation: Urology. 2001 Sep;58(3):345-50
references.pmid: 11549477
references.citation: Ann Surg. 2009 Aug;250(2):187-96
references.pmid: 19638912
references.citation: J Endourol. 2007 May;21(5):545-50
references.pmid: 17523912