title: Complications of laparoscopic and percutaneous renal cryoablation in a single tertiary referral center.
abstract: BACKGROUND
  Laparoscopic cryoablation (LCA) and percutaneous cryoablation (PCA) of small renal masses have gained popularity, but only limited data exist on the complication rates.
  
  
  OBJECTIVE
  In this study, we report on postoperative complications associated with LCA and PCA in a single tertiary center experience.
  
  
  METHODS
  We conducted a retrospective review of electronic medical records for patients undergoing LCA or PCA between 2001 and 2008 at our institution.
  
  
  METHODS
  All patients underwent LCA or PCA.
  
  
  METHODS
  Demographics, radiographic variables, and complication rates were compared between the two groups. Complications were classified according to the modified Clavien system.
  
  
  CONCLUSIONS
  Of a total of 195 patients included in this study, 72 underwent LCA and 123 underwent PCA. There were no differences in demographics between the groups. We observed complications in 10 LCA procedures (13.9%) and 26 PCA procedures (21.1%) (p=0.253). The distribution of the complications differed significantly between the groups with mild complications (grades 1 and 2) more common in the PCA group (20.3% vs 5.6%, respectively; p=0.001), whereas severe events (grades 3 and 4) were more frequent in the LCA group (8.3% vs 0.8%, respectively; p=0.011). On multivariate analysis, age and body mass index were inversely associated with complications, whereas female gender, multiple tumors, and preexisting comorbidities showed a trend toward increased risk.
  
  
  CONCLUSIONS
  LCA and PCA, although minimally invasive, are not void of complications. Most of the complications encountered are mild; however, severe (grade 3 or 4) events may occur in up to 3.6% of patients. PCA may be associated with a higher rate of complications, although most of these are mild and transient. However, on multivariate analysis, the chosen ablative approach (laparoscopic or percutaneous) is not associated with the risk of complications.
authors.affiliation: Division of Urology, Department of Surgery, Duke University Medical Center, Durham, NC, USA.
authors.forename: Matvey
authors.initials: M
authors.lastname: Tsivian
authors.forename: Valerie H
authors.initials: VH
authors.lastname: Chen
authors.forename: Charles Y
authors.initials: CY
authors.lastname: Kim
authors.forename: Dorit E
authors.initials: DE
authors.lastname: Zilberman
authors.forename: Vladimir
authors.initials: V
authors.lastname: Mouraviev
authors.forename: Rendon C
authors.initials: RC
authors.lastname: Nelson
authors.forename: David M
authors.initials: DM
authors.lastname: Albala
authors.forename: Thomas J
authors.initials: TJ
authors.lastname: Polascik
mesh_terms: D000368:Aged; D015331:Cohort Studies; D003452:Cryosurgery / Q000009:adverse effects*; D005260:Female; D006801:Humans; D007680:Kidney Neoplasms / Q000601:surgery*; D010535:Laparoscopy / Q000009:adverse effects*; D008297:Male; D008875:Middle Aged; D011183:Postoperative Complications / Q000453:epidemiology* / Q000601:surgery; D015995:Prevalence; D012189:Retrospective Studies; D016896:Treatment Outcome