Rendon R A, Gertner M R, Sherar M D, Asch M R, Kachura J R, Sweet J, Jewett M A
Division of Urology, Department of Surgery, Toronto General Hospital and Princess Margaret Hospital, University of Toronto, Ontario, Canada.
J Urol. 2001 Jul;166(1):292-8.
Incidentally detected small renal tumors appear to grow slowly and be localized to the kidney. Minimally invasive therapies are being investigated as alternatives to standard surgical techniques. Radiofrequency ablation has been reported for the treatment of small renal cell carcinomas. We developed a radiofrequency technique and established its efficacy and safety in a large animal model.
A total of 22 lesions were created in normal kidneys of 7 pigs. Radiofrequency energy was administered during open exposure of the kidneys or percutaneously under ultrasound guidance. Lesion development was monitored with gray-scale and power Doppler ultrasound. To avoid heating surrounding tissues new hydro-dissection and gas-dissection techniques were developed. Lesion sizes and characteristics were assessed by ultrasound and pathological examination.
No complications were observed due to probe insertion and removal. Perirenal structures were thermally damaged before the development and application of the dissection techniques. Lesion size was accurately predicted by gray-scale ultrasound on day 7. Loss of perfusion in the ablated volume was confirmed by power Doppler ultrasound. Lesions were wedge-shaped, presumably due to the effects of heating on segmental blood flow distribution. Pathological examination revealed changes consistent with thermal injury and ischemic type infarction.
Radiofrequency thermal therapy is an effective and efficient method for ablating normal renal tissue in the pig. It may be applied percutaneously under ultrasound guidance with minimal complications provided that vital adjacent structures are protected from thermal damage. Further studies are required in humans before adopting this technique as definitive treatment for small renal cell carcinoma.
偶然发现的小肾肿瘤似乎生长缓慢且局限于肾脏。目前正在研究微创治疗方法作为标准手术技术的替代方案。已有报道采用射频消融治疗小肾细胞癌。我们开发了一种射频技术，并在大型动物模型中确定了其有效性和安全性。
在7头猪的正常肾脏中总共制造了22个病灶。在肾脏开放暴露期间或在超声引导下经皮给予射频能量。用灰阶和能量多普勒超声监测病灶发展情况。为避免加热周围组织，开发了新的水分离和气体分离技术。通过超声和病理检查评估病灶大小和特征。
未观察到因探头插入和取出导致的并发症。在分离技术开发和应用之前，肾周结构受到了热损伤。灰阶超声在第7天准确预测了病灶大小。能量多普勒超声证实消融区域灌注消失。病灶呈楔形，可能是由于加热对节段性血流分布的影响。病理检查显示与热损伤和缺血性梗死一致的变化。
射频热疗是一种消融猪正常肾组织的有效方法。如果保护重要的相邻结构免受热损伤，可在超声引导下经皮应用，并发症极少。在将该技术作为小肾细胞癌的确定性治疗方法应用于人类之前，还需要进一步研究。
