title: Characteristics of laparoscopic microwave ablation with renal tissue: Experimental in vivo study using a porcine model.
abstract: OBJECTIVE
  A model of in vivo porcine kidneys is used to clarify the characteristics of laparoscopic microwave ablation (MWA) of renal tissue.
  
  
  METHODS
  Six pigs were utilised for the experiment using 18G water circulating-cooling microwave needles. The operating frequency was 2450 MHz, and the independent variables were power (50-60 W) and time (300-600 s). The kidneys were dissociated laparoscopically and ablated with a single or double needle at different power/time combinations and depths of puncture. Changes in the kidneys were carefully observed. Specimens of the ablated lesions were stained with haematoxylin-eosin (H&E) to evaluate the pathological features.
  
  
  RESULTS
  Thirty-four thermoablations were applied. The effective ablation shape was similar to a chestnut. The ablated lesions could be divided into three zones: carbonization zone, coagulation zone, and inflammatory reaction zone. The ablation zone enlarged with increasing power and time. When combined with two needles, the maximum diameter of the ablated lesions significantly increased. Pathological results indicated that renal tissues of the carbonisation zone were thoroughly necrotic. Coagulative necrosis was observed in the coagulation zone. No 'skipped' areas were noted in any ablation zone. The structure of the inflammatory reaction zone was integrated, and interstitial small blood vessels were highly expanded and congested with infiltrated inflammatory cells.
  
  
  CONCLUSIONS
  MWA achieved excellent effects in this porcine model. It can be safely and effectively used in renal tissue. For patients with poor physical condition or small renal masses (<4 cm), we can refer to these data and select the appropriate combinations to obtain satisfactory therapeutic efficacy.
authors.affiliation: a Department of Urology , Beijing Cancer Hospital (Beijing Institute for Cancer Research) , Beijing .
authors.forename: Baoan
authors.initials: B
authors.lastname: Hong
authors.affiliation: a Department of Urology , Beijing Cancer Hospital (Beijing Institute for Cancer Research) , Beijing .
authors.forename: Xin
authors.initials: X
authors.lastname: Du
authors.affiliation: c Department of Pathology , Beijing Chaoyang Hospital, Capital Medical University , Beijing , and.
authors.forename: Yuan
authors.initials: Y
authors.lastname: Zhao
authors.affiliation: d Department of Urology , Xinjiang Production and Construction Corps Korla Hospital , Xinjiang , China.
authors.forename: Guowei
authors.initials: G
authors.lastname: Chen
authors.affiliation: a Department of Urology , Beijing Cancer Hospital (Beijing Institute for Cancer Research) , Beijing .
authors.forename: Xiaodong
authors.initials: X
authors.lastname: Zhang
authors.affiliation: b Department of Urology , Beijing Chaoyang Hospital, Capital Medical University , Beijing .
authors.forename: Ning
authors.initials: N
authors.lastname: Zhang
authors.affiliation: b Department of Urology , Beijing Chaoyang Hospital, Capital Medical University , Beijing .
authors.forename: Yong
authors.initials: Y
authors.lastname: Yang
mesh_terms: D000818:Animals; D017115:Catheter Ablation; D005260:Female; D007668:Kidney / Q000473:pathology / Q000601:surgery*; D010535:Laparoscopy; D008872:Microwaves; D013552:Swine
keywords: Ablation techniques; kidney neoplasms; laparoscope; microwave