title: Superficial contact cryoablation attenuates experimentally created lung air leakage.
abstract: Previously, we, and others found that cryoablation on normal lung produced localized pulmonary hemorrhage and edema, causing obliteration of air space. Therefore, we hypothesized that lung air leakage may be diminished by this procedure. In the present study, we examined if cryoablation can attenuate experimentally created lung air leakage. Male domestic pigs (n=4) underwent a thoracotomy. The lung was resected approximately 5 mm in diameter and 1mm in depth to create air leakage lesions. An argon gas cryoprobe with a copper plate attached to its tip was used to cryoablate the lesions superficially. After cryoablation, the positive airway pressure that produced macroscopic bubbles from each lesion site was compared between cryoablated and untreated lesions. Also, cryoablation of the lung surface was carried out in male Donryu rats (n=20) which were sequentially sacrificed to observe the histological changes over a time course. In the pigs, the air leakage pressure was significantly increased with cryoablation (40 cmH2O <) compared to no treatment (19+/-5 cmH2O) (p=0.021, Mann-Whitney U test). Histologically, cryoablation produced acute pulmonary hemorrhage and edema. In the rats, the region with extensive hemorrhage progressed to fibrosis in 1 month, and the areas with edema recovered. This study provides supportive evidence that cryoablation has the potential to stop air leakage from surface pulmonary injury. This procedure may provide a useful adjunct to surgical resection for spontaneous pneumothorax, and the control of air leakage from dissected raw lung surfaces during lung resection.
authors.affiliation: Division of General Thoracic Surgery, Department of Surgery, School of Medicine, Keio University, Tokyo, Japan.
authors.forename: Yotaro
authors.initials: Y
authors.lastname: Izumi
authors.forename: Norimasa
authors.initials: N
authors.lastname: Tsukada
authors.forename: Eiji
authors.initials: E
authors.lastname: Ikeda
authors.forename: Masafumi
authors.initials: M
authors.lastname: Kawamura
authors.forename: Koichi
authors.initials: K
authors.lastname: Kobayashi
mesh_terms: D000818:Animals; D003452:Cryosurgery / Q000379:methods*; D004195:Disease Models, Animal; D006470:Hemorrhage / Q000209:etiology / Q000473:pathology; D008297:Male; D011030:Pneumothorax / Q000473:pathology / Q000601:surgery*; D011654:Pulmonary Edema / Q000209:etiology / Q000473:pathology; D051381:Rats; D034421:Sus scrofa