射频导管消融与经球囊超声导管消融犬下腔静脉口的病理对照研究

目的：观察并对比射频导管消融与经球囊超声导管消融犬下腔静脉开口处后静脉壁的近期及远期病理改变，探讨消融术后静脉狭窄的病理机制。方法：对两组共6条杂种犬行下腔静脉造影后分别用射频及超声能量消融下腔静脉开口处，术后30min,4周，12周分别取两组试验犬各1条，重复下腔静脉造影后处死，取被消融处组织制成切片，光镜下观察。结果：下腔静脉造影示射频导管消融组术后30min,3条犬均有下腔静脉不同程度的狭窄，而超声消融组则没有。术后12周时处死的两条犬均有管腔狭窄，慢性期大体标本显示射频导管消融术后可使静脉客壁形成局限的，僵硬的，形状不规则的疤痕，管壁挛缩，而超声组在静脉内壁仅形成光滑的，均匀的，连续的环状损伤，组织学观察均显示不同程度的内膜损伤及增生，全层肌组织破坏并逐渐被纤维组织取代，管壁挛缩，但射频导管消融组改变更明显。结论：射频导管消融与经球囊超声导管消融均可造成血管透壁损伤，术后病理演变过程相似，超声在血管内壁造成的损伤轻微，均匀，呈连续环状，慢性期修复反应较轻，虽有形成管腔狭窄的可能，但较射频导管消融组轻微，且操作简便，效果确切，是较为理想的消融方法。

Comparison of the pathological effects of radiofrequency and through-the-balloon ultrasound catheter abla tion in the orifice of the inferior vena cava in canines

Objective To observe and compare the short-and long-term pathological effects of radiofre-quency(RF) and ultrasound energy application in the orifice of inferior vena cava(IVC) in dogs. Methods Six mongrel dogs were equally divided into two groups, with RF catheter ablation (RFCA) and through-the-balloon ultrasound ablation (TTB-USA) performed within the IVCs, respectively. Animals were euthanized at 30 minutes,4,12 weeks after repeat IVC angiography. Sections were cut and examined under the light microscope. Results All the 3 RF ablated IVC developed significant venous stenosis scon after the ablation while none was found among the TTB-USA group. Venous stenosis were found with both group at 12 weeks. On gross examination, RFCA produced tissue necrosis and white, firm, irregularly contracted scars while lesions caused by TTB-USA were smooth, even and continuously circumferential. Histological examination revealed that intimal injury and proliferation, necrotic myocardium in various stages of collagen replacement, vascular contraction were found in both groups and were more serious in RFCA group. Conclusions Both RF and ultrasound energy could produce transmural lesions in the IVC. The ablated veins shared similar pathological procedure. Ultrasound energy injured venous slightly and the lesions tended to be continuously circumferential and smooth,so it is of less possibility to lead to venous stenosis compared with RFCA and might be relatively ideal energy for catheter ablation.