Histologic study of chronic catheter cryoablation of atrioventricular conduction in swine.
Histologic study of chronic catheter cryoablation of atrioventricular conduction in swine.
复制标题
猪房室传导慢性导管冷冻消融的组织学研究。
DOI：
10.1016/0002-8703(93)90752-u
复制
发表时间：
1993
影响因子：
4.8
通讯作者：
Gillette,PC
中科院分区：
文献类型：
--
作者：
Fujino,H;Thompson,RP;Germroth,PG;Harold,ME;Swindle,MM;Gillette,PC
为了评价导管冷冻消融的有效性，我们研究了冷冻消融中央传导组织后6周8只猪房室（AV）交界处的组织学变化。通过无电极的8 F或11 F冷冻导管对房室结施加−60° C的低温，并在获得完全房室传导阻滞后维持3分钟。6周后，肉眼检查显示每只动物三尖瓣隔叶上或上方有一个明显的椭圆形瘢痕，长沿着5 - 8 mm。显微镜下，消融部位离散，被致密结缔组织替代，无慢性炎症体征。瘢痕组织中常可见新生血管形成，病变内小分支或冠状血管通畅，伴轻度内膜增生。三只动物的消融病变涉及肌性室间隔顶部的一小部分区域，但在主动脉壁或主动脉瓣基部从未发现病变。在所有5只完全性房室传导阻滞的动物中，消融近端房室传导系统（穿透束或房室结的一部分）。3只未维持完全房室传导阻滞的动物在房室结或穿透束上方的房间隔中显示瘢痕形成;其中2处病变的瘢痕组织中嵌入了存活的心房心肌小岛。导管冷冻消融术可以产生与心脏直视手术中一样有效的损伤，并且是治疗顽固性室上性心动过速的可能方法。可能需要改进技术或冷冻导管，以产生更可靠的定位和均匀的疤痕。
To evaluate the efficacy of catheter cryoablation, we studied histologic changes of the atrioventricular (AV) junction in eight pigs 6 weeks after cryoablation of central conducting tissue. Cryothermia at −60° C was applied to the AV junction through an 8F or 11F cryocatheter with no electrode and was maintained for 3 minutes after complete AV block was obtained. Six weeks later, gross inspection revealed a distinct, oval-shaped scar 5 to 8 mm in length along or above the septal leaflet of the tricuspid valve in each animal. Microscopically, ablated sites were discrete and were replaced by dense connective tissue with no signs of chronic inflammation. Neovascularization was often seen in scar tissue, and small branches or coronary vasculature within lesions appeared patent with mild intimal proliferation. Ablated lesions involved a small area of the summit of the muscular interventricular septum in three animals, but lesions were never found in the base of the aortic wall or aortic valve. The proximal AV conduction system, either the penetrating bundle or a portion of the AV node, was ablated in all five animals with complete AV block. Three animals that did not maintain complete AV block showed scar formation in the atrial septum above the AV node or penetrating bundle; two of these lesions had small islands of viable atrial myocardium embedded within scar tissue. Catheter cryoablation can produce lesions as effectively as those created during open-heart surgery and is a possible procedure for treatment of intractable supraventricular tachycardia. Improvements in technique or in the cryocatheter may be needed to create more reliably located and homogeneous scar.