Recanalization of thrombosed superficial femoral arteries with a hydraulic thrombectomy catheter in a canine model.

OBJECTIVE: This experiment was conducted to evaluate efficacy and safety of the Oasis thrombectomy catheter on arterial thrombosis in dogs. MATERIALS AND METHODS: Thrombosis was induced in 18 femoral arteries of nine mongrel dogs. Recanalization of the thrombosed femoral artery was performed using a thrombectomy catheter 7-10 days after thrombus induction. Pre- and postprocedural arterial status was documented by angiography. After mechanical thrombectomy, the animals were sacrificed and the femoral arteries were harvested and examined macro- and microscopically. Additionally, in vitro fragmentation was carried out to determine particle size and distribution from the recovered effluent. RESULTS: Subacute thrombosis was successfully created in 15 femoral arteries. Full recanalization was achieved in 80% (12/15) of the thrombosed femoral arteries without any residual thrombus. No significant downstream embolization was documented angiographically. Endothelial denudation was observed in all the treated arteries along with occasional disruption of the internal elastic lamina. No medial injury was seen. Ninety-eight percent of thrombus was liquefied, defined as particles smaller than 15 microm, by the catheter. Particles larger than 400 microm represented 0.27% of the original clot weight. CONCLUSION: Occluded femoral arteries with 7- to 10-day-old thrombus can be efficiently recanalized with the Oasis catheter in dogs without any significant complication. This thrombectomy catheter appears to be highly effective and safe and requires no sophisticated equipment. Blood loss was our major concern regarding use of this catheter but can be minimized by strictly controlling activation time and restricting the inflow into the vascular segment being treated.

Percutaneous implantation of non-small-cell lung carcinoma: technique and observations.

RATIONALE AND OBJECTIVES: The authors performed this study to determine whether intrathoracic inoculation of non-small-cell lung carcinoma with fluoroscopic guidance would provide for more accurate implantation. MATERIALS AND METHODS: A tumor cell inoculum (2 x 10(6) cells per 0.15 mL) was injected percutaneously under fluoroscopic guidance at the posterior midaxillary line in 22 athymic nude mice. The mice underwent imaging with a mammographic unit at 3, 5, and 8 weeks after implantation. The mice were sacrificed at 8 weeks, and autopsy was performed to determine tumor yield. RESULTS: The use of a percutaneous technique under fluoroscopic guidance greatly facilitated the accurate implantation of xenografts. Tumor growth was seen at radiography in 18 of the 22 (82%) mice at 8 weeks. Necropsy revealed a 100% tumor yield. Histologic examination confirmed adenocarcinoma of the lung. The average number of tumors found in the lung parenchyma was 1.05 +/- 0.35; the average number of tumors found in the mediastinum was 0.59 +/- 0.67. The average tumor weight was 389 mg +/- 64.3. The average tumor size was 300 mm3 +/- 66.23. CONCLUSION: With fluoroscopic guidance, percutaneous implantation of tumor cells in athymic nude mice is simple and effective.

Effects of anti-erbB-2 (HER-2/neu) recombinant oncotoxin AR209 on human non-small cell lung carcinoma grown orthotopically in athymic nude mice.

The recombinant oncotoxin AR209 [e23(Fv)PE38KDEL; formerly OLX-209] was developed to treat neoplasia that expresses the c-erbB-2 (HER-2/neu) protein product p185(erbB-2). The AR209 compound contains a single-chain antibody domain specific for p185(erbB-2), coupled with a portion of the Pseudomonas exotoxin. The drug has been shown to be effective in inhibiting cells that overexpress erbB-2 due to gene amplification and in cells that do not contain amplified erbB-2 but express slightly higher levels of the protein than normal cells do. To test the efficacy of AR209 on human lung tumors, athymic nude mice were inoculated intrathoracically with a cell line derived from a poorly differentiated lung adenocarcinoma. This cell line, termed 201T, expresses moderately elevated levels of p185(erbB-2) 7.6-fold over normal bronchial epithelium. Mice treated with i.v. injections of AR209 for 5 weeks after orthotopic tumor implantation had smaller tumors and in 20% of cases showed no evidence of disease. The data from this study indicate that AR209 may be an effective treatment for patients with non-small cell lung cancers that express p185(erbB-2).