title: Perioperative morbidity of laparoscopic cryoablation of small renal masses with ultrathin probes: a European multicentre experience.
abstract: BACKGROUND
  Low morbidity has been advocated for cryoablation of small renal masses.
  
  
  OBJECTIVE
  To assess negative perioperative outcomes of laparoscopic renal cryoablation (LRC) with ultrathin cryoprobes and patient, tumour, and operative risk factors for their development.
  
  
  METHODS
  Prospective collection of data on LRC in five centres.
  
  
  METHODS
  LRC.
  
  
  METHODS
  Preoperative morbidity was assessed clinically and the American Society of Anaesthesiologists (ASA) score was assigned prospectively. Charlson Comorbidity Index (CCI) and Charlson-Age Comorbidity Index (CACI) scores were retrospectively assigned. Negative outcomes were prospectively recorded and defined as any undesired event during the perioperative period, including complications, with the latter classed according to the Clavien system. Patient, tumour, and operative variables were tested in univariate analysis as risk factors for occurrence of negative outcomes. Significant variables (p<0.05) were entered in a step-forward multivariate logistic regression model to identify independent risk factors for one or more perioperative negative outcomes. The confidence interval was settled at 95%.
  
  
  CONCLUSIONS
  There were 148 procedures in 144 patients. Median age and tumour size were 70.5 yr (range: 32-87) and 2.6 cm (range: 1.0-5.6), respectively. A laparoscopic approach was used in 145 cases (98%). Median ASA, CCI, and CACI scores were 2 (range: 1-3), 2 (range: 0-7), and 4 (range: 0-11), respectively. Comorbidities were present in 79% of patients. Thirty negative outcomes and 28 complications occurred in 25 (17%) and 23 (15.5%) cases, respectively. Only 20% of all complications were Clavien grade > or = 3. Multivariate analysis showed that tumour size in centimetres, the presence of cardiac conditions, and female gender were independent predictors of negative perioperative outcomes occurrence. Receiver operator characteristic curve confirmed the tumour size cut-off of 3.4 cm as an adequate predictor of negative outcomes.
  
  
  CONCLUSIONS
  Perioperative negative outcomes and complications occur in 17% and 15.5%, respectively, of cases treated by LRC with multiple ultrathin needles. Most of the complications are Clavien grade 1 or 2. The presence of cardiac conditions, female gender, and tumour size are independent prognostic factors for the occurrence of a perioperative negative outcome.
authors.affiliation: Department of Urology, AMC University Hospital, Amsterdam, The Netherlands. m.p.lagunapes@amc.uva.nl
authors.forename: M Pilar
authors.initials: MP
authors.lastname: Laguna
authors.forename: Patricia
authors.initials: P
authors.lastname: Beemster
authors.forename: Vivenkanandar
authors.initials: V
authors.lastname: Kumar
authors.forename: Patricia
authors.initials: P
authors.lastname: Kumar
authors.forename: H Christoph
authors.initials: HC
authors.lastname: Klingler
authors.forename: Stephen
authors.initials: S
authors.lastname: Wyler
authors.forename: Chris
authors.initials: C
authors.lastname: Anderson
authors.forename: Francis X
authors.initials: FX
authors.lastname: Keeley
authors.forename: Alexander
authors.initials: A
authors.lastname: Bachmann
authors.forename: Jorge
authors.initials: J
authors.lastname: Rioja
authors.forename: Charalampos
authors.initials: C
authors.lastname: Mamoulakis
authors.forename: Michael
authors.initials: M
authors.lastname: Marberger
authors.forename: Jean J
authors.initials: JJ
authors.lastname: de la Rosette
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D003452:Cryosurgery / Q000009:adverse effects* / Q000379:methods*; D005060:Europe; D005260:Female; D006801:Humans; D007680:Kidney Neoplasms / Q000473:pathology / Q000601:surgery*; D010535:Laparoscopy; D008297:Male; D008875:Middle Aged; D011183:Postoperative Complications / Q000453:epidemiology / Q000209:etiology; D011446:Prospective Studies; D012307:Risk Factors