Thrombectomy with the transluminal endarterectomy catheter (TEC) system: experimental study and case report

Pharmacomechanical thrombolysis with use of the brush catheter in canine thrombosed femoropopliteal arterial PTFE bypass grafts

PURPOSE

To assess the efficacy, acute endothelial changes, and distal arterial emboli after use of the Cragg thrombolytic brush catheter in mature thrombosed polytetrafluoroethylene (PTFE) femoropopliteal arterial grafts in canines.

MATERIALS AND METHODS

PTFE femoropopliteal arterial grafts were implanted in 10 canines and were allowed to mature for approximately 4 weeks. The grafts were thrombosed by mechanical means and allowed to remain thrombosed for 24-72 hours. Through a left carotid cut-down, standard Seldinger arterial puncture was performed, followed by catheterization of the thrombosed graft. A soft, low-speed, brush (6 mm in diameter) aided by preprocedure pulse-spray urokinase infusion was utilized for thrombolysis. The native vessels, just proximal and distal to the anastomosis, were evaluated microscopically for endothelial damage. Arteriography was used for assessment of distal embolus.

RESULTS

All grafts were successfully thrombosed before thrombolysis. One graft could not be traversed with a wire and catheter and was, therefore, not treated. Immediate preprocedure pulse-spray urokinase infusion in the remaining nine grafts did not reconstitute antegrade flow in any instance and left significant amounts of residual thrombus in all treated grafts. Mechanical brush thrombolysis reconstituted antegrade flow in all nine treated grafts and complete graft thrombolysis was obtained in most. This was accomplished in a mean time of less than 4 minutes. Emboli were noted angiographically in 67% of cases. Histologic studies showed vessel wall damage limited to the intima or media in 67% of anastomoses.

CONCLUSION

This method offers a simple and rapid means of recanalizing thrombosed PTFE femoropopliteal arterial grafts in the studied model. This technique provides a means of rapidly "debulking" most intragraft thrombi. This may result in a shorter course of thrombolytic infusion. Potential benefits may include shortening the total treatment time and decreasing morbidity and cost associated with percutaneous thrombolysis. The occurrence of distal emboli in a majority of cases is a concerning limitation of this technique.

A new rotational thrombectomy catheter: system design and first clinical experiences

PURPOSE

To describe a new catheter for the percutaneous mechanical removal of fresh and organized thrombi, and to assess its efficacy and safety in vitro and in vivo.

METHODS

The catheter consists of a coated stainless steel spiral that rotates at 40,000 rpm over a guidewire inside the whole length of an 8 Fr, single-lumen, polyurethane catheter, driving a dual-blade cutting crown. Abraded occlusion material is sucked into the catheter head through distal side holes and transported by the spiral into a reservoir at the proximal end. The efficacy of the device was tested in arterial models and fresh bovine carotid arteries (n = 72). In a clinical pilot study 10 patients (8 women, 2 men; mean age 70.6 +/- 10.1 years) with occlusions of the superficial femoral artery (2-12 cm, mean 5.8 cm), not older than 4 weeks, underwent thrombectomy with the new catheter.

RESULTS

In arterial models and bovine cadaver arteries the catheter completely removed fresh thrombi. Occlusion material of higher consistency was cut into particles of 100-500 micron and transported outside. Thrombectomy was successful and vessel patency restored in all 10 patients. The ankle/brachial pressure index significantly (p < 0.0005) increased from 0.41 +/- 0. 18 before intervention to 0.88 +/- 0.15 after 48 hr and to 0.84 +/- 0.20 after 3 months. Two reocclusions occurred within 14 days after the intervention.

CONCLUSION

Thrombectomy with the new device appears to be feasible and safe in patients with acute and subacute occlusions of the femoropopliteal artery.

Short-term results with use of the Amplatz thrombectomy device in the treatment of acute lower limb occlusions

PURPOSE

To evaluate the clinical efficacy of the Amplatz device for the treatment of acute occlusions of the lower limb arteries.

MATERIALS AND METHODS

Forty patients with acute occlusion of the lower limb arteries (3 hours to 8 days; mean, 2 days) were treated using the Amplatz clot macerator. Acute thrombotic lower limb occlusion was due to an embolic event in 32 patients and to atherosclerotic disease in eight patients.

RESULTS

Complete success, with complete clearing of thrombotic material without an adjunctive procedure, was achieved in 75% (30 of 40) of the patients. Mean thrombectomy time in these patients was 75 seconds. Partial success, with incomplete clearing of the thrombus, requiring additional procedures such as local thrombolysis, angioplasty, or atherectomy, was achieved in 20% (eight of 40) of the patients. The Doppler index increased significantly (P < .001) from .45 before intervention to .96 after intervention. There were two failures (5%). No major complications occurred.

CONCLUSION

Mechanical thrombectomy with use of the Amplatz device is a promising approach for quick recanalization of acute peripheral thromboembolic occlusions. Further studies are needed to prove the long-term patency after mechanical thrombectomy with use of this device.

Mechanical thrombectomy with the Amplatz device: human experience

PURPOSE

The authors present their early experience of mechanical arterial and graft thrombectomy with the Amplatz thrombectomy device.

PATIENTS AND METHODS

Preliminary data are presented for 14 patients treated with the Amplatz thrombectomy catheter. The procedure was carried out in 10 arterial polytetrafluorethylene grafts, in two native arteries, and in two patients with venous thrombosis.

RESULTS

The thrombectomy catheter completely removed the clot in 11 patients and partially removed clot in three patients. Mean thrombectomy time was 2 minutes 45 seconds. Despite distal blood pressure cuff occlusion, two instances of insignificant distal embolization occurred. Mechanical clot dissolution has consistently produced hemolysis without adverse clinical effects. The underlying causative factors such as stenoses were treated by means of angioplasty, atherectomy, or surgical endarterectomy.

CONCLUSION

Mechanical thrombectomy with this device is a new, effective technique and can rapidly remove the thrombus. From preliminary results, the device seems most promising in clearing out thrombi in occluded synthetic femoral-to-popliteal bypass grafts. The device could have wider application if it were steerable and if it could be introduced from the contralateral approach.

New approach to superior vena caval obstruction

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Hemolytic effect of the Amplatz thrombectomy device

PURPOSE

The hemolytic effect of the Amplatz thrombectomy device (ATD) was evaluated in nine dogs and in nine patients.

MATERIALS AND METHODS

The device was activated for 1-2 minutes in the abdominal aorta, inferior vena cava, or femoral artery of nine dogs. The device was activated for 1-4 minutes in the nine patients in occluded lower extremity bypass grafts (n = 5), native superficial femoral artery (n = 1), a pulmonary artery embolus (n = 1), a portocaval shunt (n = 1), and an iliac vein stent (n = 1). Patients were examined for laboratory evidence of hemolysis following mechanical thrombectomy.

RESULTS

In all dogs haptoglobin level decreased, free hemoglobin level in the plasma increased, and hemoglobinuria was present. There was no change in renal function. The level of haptoglobin decreased and the level of plasma free hemoglobin increased in eight patients, with hemoglobinuria detected in one. More hemolysis was observed in the animals than in the patients.

CONCLUSION

The ATD has a definite transient hemolytic effect. Until further studied, it should not be used in children and should be used with caution in patients who are anemic, hypoxemic, or have potentially reversible renal insufficiency. Activation time should be monitored closely because hemolysis probably increases with increasing activation time.

Case report: superior vena caval obstruction treated by thrombolysis, mechanical thrombectomy and metallic stents

We describe a case of superior vena caval obstruction (SVCO) due to bronchial carcinoma which was complicated by extensive central venous thrombosis. Partial clot lysis was achieved with thrombolytic agents, but therapy had to be discontinued due to bleeding from the gastrointestinal tract and puncture sites. Clot dissolution was completed using the Amplatz Thrombectomy Device, and the subsequent placement of a Gianturco Z-stent resulted in prolonged symptomatic relief.

Thromboembolectomy with the transluminal extraction catheter (TEC) as an adjunct to thrombolysis

Multiple surgical and percutaneous interventional radiologic techniques have been used to restore blood flow in an acutely ischemic extremity. The transluminal extraction catheter (TEC) system was used as a mechanical thromboembolectomy device to supplement pharmacologic thrombolysis in one patient. In this case, 40 hours of direct intraarterial infusion of urokinase into the occluded vascular segments of a threatened lower extremity resulted in incomplete thrombolysis. Therefore, a 7-F TEC system was advanced percutaneously through the occluded vessels with restoration of luminal patency in all vessels treated. No distal embolization occurred. The TEC system facilitated prompt recanalization of vessels occluded by acute thrombus superimposed on atherosclerotic disease.