title: Percutaneous imaging-guided solid organ core needle biopsy: coaxial versus noncoaxial method.
abstract: OBJECTIVE
  The purpose of our study was to compare the diagnostic yield and complication rate of coaxial technique with those of noncoaxial technique in percutaneous imaging-guided renal and hepatic core biopsies. We also compared bleeding complication rates with and without absorbable gelatin sponge occlusion of the biopsy track.
  
  
  METHODS
  The records of 1,060 consecutively registered patients who underwent percutaneous imaging-guided hepatic or renal biopsy at two hospitals were retrospectively reviewed. Core specimens were obtained in all biopsies. Indications for biopsy included acquisition of general tissue specimens to evaluate for hepatic (n = 495) or renal disease (n = 243) and acquisition of specimens of specific hepatic (n = 289) and renal (n = 33) lesions. Samples were acquired with a coaxial set of needles (n = 764) or with a noncoaxial needle (n = 296 patients). Absorbable gelatin sponge was injected before removal of the outer needle in 269 of the 764 coaxial biopsies. Gelatin sponge was not injected in the other 495 coaxial biopsies. Complication rates were evaluated in a comparison of the two methods and of the coaxial biopsies with and without postprocedural injection of gelatin sponge. Complications were considered minor if follow-up imaging in the 7 days after the procedure showed a complication that did not necessitate treatment other than conservative pain management. Complications were considered major if treatment such as blood product transfusion or surgery was needed or if the patient died.
  
  
  RESULTS
  Specimens were immediately given to a pathologist, who typically was present during the procedure. Specimens were evaluated and judged adequate for a specific diagnosis by the histopathology staff. The rates of minor complications were 3.4% (10/296) for the noncoaxial method and 2.6% (20/764) for the coaxial method. The rates of major complications were 1.0% (3/296) for the noncoaxial method and 0.9% (7/764) for the coaxial method. Six cases of major complications necessitating blood product transfusion were documented for the coaxial method and one case for the noncoaxial method. One (0.1%) of the patients undergoing coaxial biopsy died. One patient undergoing noncoaxial biopsy needed surgical repair of an arterial injury that was refractory to blood transfusion, and another developed pancreatitis and needed a blood transfusion. The percentage of minor complications of the coaxial method with absorbable gelatin sponge injection was 3.7% (10/269), and that of major complications was 0.7% (2/269). There was no statistical difference in complication rates between the various methods of percutaneous hepatic and renal biopsy.
  
  
  CONCLUSIONS
  In regard to complications, there are no differences between coaxial and noncoaxial biopsy methods or between the coaxial method with or without injection of absorbable gelatin sponge.
authors.affiliation: Milwaukee Radiologists, Ltd., affiliated with Aurora St. Luke's Medical Center, Milwaukee, WI, USA. Hatfield@pol.net
authors.forename: Malcolm K
authors.initials: MK
authors.lastname: Hatfield
authors.forename: Robert A
authors.initials: RA
authors.lastname: Beres
authors.forename: Shekhar S
authors.initials: SS
authors.lastname: Sane
authors.forename: George X
authors.initials: GX
authors.lastname: Zaleski
mesh_terms: D001707:Biopsy, Needle / Q000706:statistics & numerical data*; D006801:Humans; D007668:Kidney / Q000473:pathology*; D008099:Liver / Q000473:pathology*; D011183:Postoperative Complications / Q000453:epidemiology*; D015995:Prevalence; D012189:Retrospective Studies; D018570:Risk Assessment / Q000379:methods*; D012307:Risk Factors; D025321:Surgery, Computer-Assisted / Q000706:statistics & numerical data*; D014922:Wisconsin / Q000453:epidemiology