Au Joyce T, Carson Joshua, Monette Sebastien, Finley David J
Department of Surgery, Thoracic Surgery, Memorial Sloan-Kettering Cancer Center, New York, NY 10065, USA.
Interact Cardiovasc Thorac Surg. 2012 Oct;15(4):580-4. doi: 10.1093/icvts/ivs192. Epub 2012 Jul 18.
Spray cryotherapy (SCT) delivers a liquid nitrogen spray via a catheter to produce cellular death. This study seeks to determine the histological changes after bronchoscopic, endoscopic and open SCT on tissues in the thoracic cavity.
Yorkshire pigs underwent flexible bronchoscopy, endoscopy and thoracotomy for SCT of the airway, oesophagus and other intrathoracic structures, respectively. Variations in the duration and number of spray cycles for the same dosimetry were compared.
Bronchoscopic SCT of the airway resulted in cellular death up to the cartilage layer. Endoscopic SCT of the oesophagus led to cell death up to the adventitial layer. Tissue necrosis was severe in the lung, of full thickness in the pleura, but very superficial in the great vessels. The extracellular matrix (ECM) of treated tissues remained well-preserved. Having shorter but more cycles of SCT decreased the depth of the cellular necrosis. One pig developed ventricular fibrillation during the surgery and expired.
SCT causes reproducible tissue injury with the preserved ECM of most tissues within the thoracic cavity, making it enticing for ablation around vital structures like the great vessels with a decreased long-term risk. Further study is warranted to investigate the adverse events during SCT.
喷雾冷冻疗法（SCT）通过导管输送液氮以导致细胞死亡。本研究旨在确定经支气管镜、内镜及开放手术进行SCT后胸腔内组织的组织学变化。
约克夏猪分别接受了柔性支气管镜检查、内镜检查及开胸手术，以对气道、食管及其他胸腔内结构进行SCT。比较了相同剂量下喷雾周期的持续时间和次数的变化。
气道的支气管镜SCT导致细胞死亡直至软骨层。食管的内镜SCT导致细胞死亡直至外膜层。肺组织坏死严重，胸膜全层坏死，但大血管处坏死非常表浅。处理后组织的细胞外基质（ECM）保存良好。进行较短但次数更多的SCT周期可减少细胞坏死深度。1头猪在手术期间发生心室颤动并死亡。
SCT可导致可重复性的组织损伤，胸腔内大多数组织的ECM得以保存，这使得其在大血管等重要结构周围进行消融具有吸引力，且长期风险降低。有必要进一步研究SCT期间的不良事件。
