The cryoablation of lung tissue using liquid nitrogen in gel and in the ex vivo pig lung.
OBJECTIVE
To examine the efficiency of cryoablation using liquid nitrogen in lung tissue, we measured the size and temperature distribution of the frozen area (iceball) in gel and in the ex vivo pig lungs.


METHODS
Cryoprobes with diameters of 2.4 and 3.4 mm (2.4D and 3.4D, respectively) were used. Three temperature sensors were positioned at the surface of the cryoprobe and at distances of 0.5 and 1.5 cm from the cryoprobe. The ex vivo pig lungs were perfused with 37 °C saline and inflated using ventilator to simulate in vivo lung conditions.


RESULTS
In gel, the 2.4D and 3.4D probes made iceballs of 3.9 ± 0.1 and 4.8 ± 0.3 cm in diameter, respectively, and the temperature at 1.5 cm from those probes reached -32 ± 8 and -53 ± 5 °C, respectively. In the pig lung, the 2.4D and 3.4D probes made iceballs of 5.2 ± 0.1 and 5.5 ± 0.4 cm in diameter, respectively, and the temperature at 1.5 cm from these probes reached -49 ± 5 and -58 ± 3 °C, respectively.


CONCLUSIONS
Liquid nitrogen cryoablation using both 2.4D and 3.4D probes made iceballs that were of sufficient size, and effective temperatures were reached in both gel and the ex vivo pig lung.
Departments of Thoracic Surgery, Kameda Medical Center, 929 Higashi-cho, Kamogawa, Chiba, 296-8602, Japan. hnomori@qk9.so-net.ne.jp.
Hiroaki
H
Nomori
Diagnostic Radiology, Kameda Medical Center, Kamogawa, Chiba, Japan.
Ikuo
I
Yamazaki
Clinical Engineering, Kameda Medical Center, Kamogawa, Chiba, Japan.
Toshiya
T
Kondo
Clinical Engineering, Kameda Medical Center, Kamogawa, Chiba, Japan.
Masaya
M
Kanno
D000818:Animals; D003080:Cold Temperature; D003452:Cryosurgery / Q000295:instrumentation* / Q000379:methods*; D005782:Gels; D008168:Lung / Q000473:pathology* / Q000601:surgery*; D008175:Lung Neoplasms / Q000601:surgery; D023421:Models, Animal; D009584:Nitrogen / Q000627:therapeutic use*; D013552:Swine
D005782:Gels; D009584:Nitrogen
Cryoablation; Liquid nitrogen; Lung cancer