title: Protective and Heat Retention Effects of Thermo-sensitive Basement Membrane Extract (Matrigel) in Hepatic Radiofrequency Ablation in an Experimental Animal Study.
abstract: OBJECTIVE
  To evaluate the protective effect of using thermo-sensitive basement membrane extract (Matrigel) for hydrodissection to minimize thermal injury to nearby structures and to evaluate its heat sink effect on the ablation zone in radiofrequency ablation (RFA) of the liver.
  
  
  METHODS
  First, the viscosity profile and heat sink effect of Matrigel were assessed during RFA in vitro and ex vivo. Fresh pig liver tissue was used, and the temperature changes in Matrigel and in 5% dextrose in water (D5W) during RFA were recorded. Then, the size of the ablation zone in the peripheral liver after RFA was measured. Second, in an in vivo study, 45 Sprague-Dawley rats were divided into three groups of 15 rats each (Matrigel, D5W and control). In the experimental groups, artificial ascites with 10 ml of Matrigel or D5W were injected using ultrasound guidance prior to RFA. The frequency of thermal injury to the nearby organs was compared among the three groups, with assessments of several locations: near the diaphragm, the abdominal wall and the gastrointestinal (GI) tract. Finally, the biological degradation of Matrigel by ultrasound was evaluated over 60 days.
  
  
  RESULTS
  First, Matrigel produced a greater heat retention (less heat sink) effect than D5W during ex vivo ablation (63 ± 9 vs. 26 ± 6 °C at 1 min on the surface of the liver, P < 0.001). Hepatic ablation zone volume did not differ between the two groups. Second, thermal injury to the nearby structures was found in 14 of 15 cases (93.3%) in the control group, 8 of 15 cases (53.3%) in the D5W group, and 1 of 15 cases (6.7%) in the Matrigel group. Significant differences in the thermal injury rates for nearby structures were detected among the three groups (P < 0.001). The most significant difference in the thermal injury rate was found in locations near the GI tract (P = 0.003). Finally, Matrigel that was injected in vivo was gradually degraded during the following 60 days.
  
  
  CONCLUSIONS
  Using thermo-sensitive Matrigel as a hydrodissection material might help reduce the frequency of collateral thermal injury to nearby structures, especially in locations close to the GI tract, compared to conventional D5W. Additionally, Matrigel did not increase the heat sink effect on the ablation zone during ablation and was degraded over time in vivo.
authors.affiliation: Key Laboratory of Carcinogenesis and Translational Research (Ministry of Education), Department of Ultrasound, Peking University Cancer Hospital, Beijing, 100142, China.
authors.forename: Jing-Jing
authors.initials: JJ
authors.lastname: Fu
authors.affiliation: Key Laboratory of Carcinogenesis and Translational Research (Ministry of Education), Department of Ultrasound, Peking University Cancer Hospital, Beijing, 100142, China.
authors.forename: Song
authors.initials: S
authors.lastname: Wang
authors.affiliation: Key Laboratory of Carcinogenesis and Translational Research (Ministry of Education), Department of Ultrasound, Peking University Cancer Hospital, Beijing, 100142, China. 13681408183@163.com.
authors.forename: Wei
authors.initials: W
authors.lastname: Yang
authors.affiliation: State Key Laboratory of Toxicology and Medical Countermeasures, Beijing Institute of Pharmacology and Toxicology, Beijing, 100850, China.
authors.forename: Wei
authors.initials: W
authors.lastname: Gong
authors.affiliation: Key Laboratory of Carcinogenesis and Translational Research (Ministry of Education), Department of Ultrasound, Peking University Cancer Hospital, Beijing, 100142, China.
authors.forename: An-Na
authors.initials: AN
authors.lastname: Jiang
authors.affiliation: Key Laboratory of Carcinogenesis and Translational Research (Ministry of Education), Department of Ultrasound, Peking University Cancer Hospital, Beijing, 100142, China.
authors.forename: Kun
authors.initials: K
authors.lastname: Yan
authors.affiliation: Key Laboratory of Carcinogenesis and Translational Research (Ministry of Education), Department of Ultrasound, Peking University Cancer Hospital, Beijing, 100142, China.
authors.forename: Min-Hua
authors.initials: MH
authors.lastname: Chen
mesh_terms: D000818:Animals; D001201:Ascites / Q000601:surgery; D001485:Basement Membrane; D002056:Burns / Q000517:prevention & control; D017115:Catheter Ablation / Q000009:adverse effects*; D003094:Collagen; D004210:Dissection / Q000379:methods*; D004338:Drug Combinations; D006358:Hot Temperature; D066298:In Vitro Techniques; D007797:Laminin; D008099:Liver / Q000601:surgery*; D008113:Liver Neoplasms / Q000601:surgery; D008297:Male; D011446:Prospective Studies; D011509:Proteoglycans; D051381:Rats; D017207:Rats, Sprague-Dawley; D025321:Surgery, Computer-Assisted; D013552:Swine
chemical_list: D004338:Drug Combinations; D007797:Laminin; D011509:Proteoglycans; C059485:matrigel; D003094:Collagen
keywords: Heat sink effect; Hydrodissection; Liver; Radiofrequency ablation; Thermal injury