title: Categorization of ureteroscopy complications and investigation of associated factors by using the modified Clavien classification system.
abstract: OBJECTIVE
  The purpose of the present study was to review the complications of ureteroscopy (URS) by using the modified Clavien classification system (MCCS) and to investigate the factors associated with complications.
  
  
  METHODS
  Data regarding 811 patients who underwent URS for ureteral calculus were analyzed. Peroperative and postoperative complications were recorded. The patients were divided into seven groups depending on the severity of the complications. The association of sex, stone size, number, and localization with each MCCS grade was also evaluated.
  
  
  RESULTS
  The average age was 45 years. The success of the procedure after one session was 93.5%. Complications were recorded in 57.9% of the patients. According to the MCCS, grade I, II, IIIa, IIIb, IVa, IVb, and V complications were documented in 29.8%, 7.1%, 8.6%, 11%, 0%, 1.2%, and 0% of the patients, respectively. The factors associated with the complications graded by MCCS were sex, stone size, number of stones, and localization. In addition, in multivariate analysis, history of previous surgeries for urolithiasis, orifice dilatation, and instrument size were associated with complications.
  
  
  CONCLUSIONS
  According to MCCS, sex, history of previous surgeries for urolithiasis, orifice dilatation, size of the instrument, stone size, number of stones, and localization are associated with different grades of complications in URS.
authors: Department of Urology, Faculty of Medicine, Giresun University, Giresun, Turkey.
authors: Ercan
authors: E
authors: Öğreden
authors: Department of Urology, Faculty of Medicine, Giresun University, Giresun, Turkey.
authors: Ural
authors: U
authors: Oğuz
authors: Department of Urology, Faculty of Medicine, Giresun University, Giresun, Turkey.
authors: Erhan
authors: E
authors: Demirelli
authors: Department of Urology, Faculty of Medicine, Ordu University, Ordu, Turkey.
authors: Erdal
authors: E
authors: Benli
authors: Department of Urology, Faculty of Medicine, Çanakkale 18 Mart University, Çanakkale, Turkey.
authors: Eyüp Burak
authors: EB
authors: Sancak
authors: Department of Urology, Faculty of Medicine, Çanakkale 18 Mart University, Çanakkale, Turkey.
authors: Murat Tolga
authors: MT
authors: Gülpinar
authors: Department of Urology, Faculty of Medicine, Çanakkale 18 Mart University, Çanakkale, Turkey.
authors: Alpaslan
authors: A
authors: Akbaş
authors: Department of Urology, Ankara Training and Research Hospital, Ankara, Turkey.
authors: Berkan
authors: B
authors: Reşorlu
authors: Department of Urology, Faculty of Medicine, Ordu University, Ordu, Turkey.
authors: Ali
authors: A
authors: Ayyildiz
authors: Department of Urology, Faculty of Medicine, Giresun University, Giresun, Turkey.
authors: Orhan
authors: O
authors: Yalçin
mesh_terms: D006801:Humans; D015999:Multivariate Analysis; D011183:Postoperative Complications; D012189:Retrospective Studies; D016896:Treatment Outcome; D014514:Ureteral Calculi; D018666:Ureteroscopy
keywords: Clavien classification system; Complication; ureterorenoscopy