title: Complications of automated spring fired biopsy gun technique. A retrospective analysis of 230 cases.
abstract: BACKGROUND
  Renal biopsy (RB) is a procedure which allows obtaining kidney tissue for a morphological diagnosis. As an invasive procedure, RB could lead to some complications. The aim of the study was to assess the incidence and the severity of various complications of renal biopsy(RB) performed by automated spring fired biopsy gun with needles 16 and 18G.
  
  
  METHODS
  A total number of 230 RB obtained from patients over 18 years of age, within the period from January 2009 to July 2013, were analyzed retrospectively. All RB were performed by a standartized technique using an automated spring fired biopsy gun, with 16, and 18 G disposable needle. The average age of the patients was 45.5 ± 22.3 years, 119 male and 111 female. As many as 170 biopsies were performed with 16 G needle and 60 with 18G. The assessment of the early post-biopsy complications was done by renal ultrasound (US).
  
  
  RESULTS
  Of all RB, 92.7% were successfully performed. In 60% of the failed RB 18 G needle was used. No post-biopsy complications were noted in 93.4%. Hematomas were observed in 15 out of 230 cases (6.6%). Of those, 80% were assessed as minor hematomas (12/15) with an average size of 20.4mm ± 11mm and they appeared to be asymptomatic.While 8 cases (66%) of all 12 minor hematomas were obtained by two passes (66%), only 4 cases (34%) of hematoma were observed after one pass <0.01. The cases of hematomas obtained with 16 G needle were significantly higher than those in the group with 18G (8 to 4, p<0,05). However, when the number of hematomas in both groups referred to the number of all biopsies in the corresponding group, no significant difference of this complication was observed, p > 0.05. The incidence of major complications was 1.3%.
  
  
  CONCLUSIONS
  The optimal period for US examination of the kidneys for early diagnosis of complications is up to 24 hours after RB. The experience of the physician performing the procedure is of great importance for reducing the risk of complications as well as the RB technique used. An automated spring fired biopsy gun with needle 16G is recommended.
authors.affiliation: Clinic of Nephrology, University Hospital "Alexandrovska", Sofia, Bulgaria"
authors.forename: M
authors.initials: M
authors.lastname: Lubomirova
authors.affiliation: Clinic of Nephrology, University Hospital "Alexandrovska", Sofia, Bulgaria"
authors.forename: T
authors.initials: T
authors.lastname: Tzocheva
authors.affiliation: Clinic of Nephrology, University Hospital "Alexandrovska", Sofia, Bulgaria"
authors.forename: M
authors.initials: M
authors.lastname: Hristova
authors.affiliation: Clinic of Nephrology, University Hospital "Alexandrovska", Sofia, Bulgaria"
authors.forename: B
authors.initials: B
authors.lastname: Bogov
keywords: Renal biopsy; biopsy complications; spring-loaded biopsy gun