1. Aetna considers the AngioJet Rheolytic Thrombectomy System, also known as the Possis AngioJet Rapid Thrombectomy System, medically necessary for removing fresh blood clots from any of the following vessels: 

   1. Coronary arteries or coronary bypass grafts greater than or equal to 2.0 mm in diameter prior to angioplasty or stent placement; or
   2. Infra-inguinal peripheral arteries greater than or equal to 2.0 mm in diameter; or

   3. Arterio-venous fistulas for hemodialysis by direct anastomosis of artery to vein or by placement of a synthetic graft (e.g., Gortex).

2. Aetna considers the AngioJet Rheolytic Thrombectomy System experimental and investigational for the treatment of deep vein thrombosis, acute renal artery thrombosis, pulmonary embolism, and for all other indications because its clinical value for these indications has not been established.

The AngioJet Rheolytic Thrombectomy System (Possis Medical, Minneapolis, MN) consists of a single-use catheter, single-use pump set, and multi-use drive unit.  The same drive unit and pump set are compatible with various catheters with different design features.  Thrombectomy is accomplished with the introduction of a pressurized saline jet stream through the directed orifices in the catheter distal tip.  The jets generate a localized low pressure zone via the Bernoulli effect, which entrains and macerates thrombus.  The saline and clot particles are then sucked back into the exhaust lumen of the catheter and out of the body for disposal.  Treatment with the device takes about one minute.

United States marketing of the AngioJet System began in 1997 following the receipt of U.S. Food and Drug Administration (FDA) marketing clearance for clot removal in A-V fistulas used for dialysis access.  In March 1999, the AngioJet System was approved by the FDA for use in native coronary vessels and coronary bypass grafts and in February 2000, an expansion of this indication was made to include the treatment of fresh thrombus from infra-inguinal peripheral arteries greater than or equal to 2.0 mm in diameter.

The AngioJet has been shown to be appropriate for removal of fresh blood clots from native coronary arteries or coronary bypass grafts prior to angioplasty or stent placement in patients sustaining acute myocardial injury.  Studies show that the AngioJet is similar in effectiveness to urokinase in removing blood clots during a heart attack; therefore, the procedure can be used as an alternative to thrombolytic drugs.

Regarding future AngioJet System applications, a four-hospital FDA clinical study is underway to evaluate AngioJet System safety and effectiveness in treating stroke caused by blood clot blockage of the carotid arteries.

Suarez, et al. (2004) stated that catheter thrombectomy techniques (e.g., aspiration thrombectomy, fragmentation thrombectomy, and rheolytic thrombectomy) are being developed to provide an alternative treatment modality for severe cases of acute massive pulmonary embolism (PE) when thrombolytics are contraindicated.  Catheter thrombectomy devices have undergone major advances over the last decade, but literature support of their success is limited.

Current evidence for the effectiveness of rheolytic thrombectomy in pulmonary embolism is limited to case reports and one small case series.  Zeni and associates (2003) examined the effectiveness of thrombus removal using the rheolytic thrombectomy catheter (RTC) in 17 patients with acute massive PE.  The RTC was successfully delivered and operated via a 0.035-inch guide wire in all attempted cases.  Treatment resulted in immediate angiographic improvement and initial relief of PE symptoms (improvement in dyspnea and oxygen saturation) in 16 of 17 patients.  One patient developed heart block during the procedure, and further treatment with the RTC was discontinued.  Bradycardia occurred in 1 patient (managed with lidocaine).  After thrombectomy, 10 patients received adjunctive reteplase thrombolysis for treatment of residual thrombus, and 12 received inferior vena cava filters.  In the patient with renal cell carcinoma, histopathological analysis of the evacuated material confirmed tumor origin of the embolism.  There were 2 deaths, both within 24 hours of treatment and secondary to PE.  One death occurred in a patient who had only minimal thrombus removal after treatment with the RTC and no thrombolysis.  The remaining 15 patients showed continued improvement in PE symptoms and were eventually discharged from the hospital with mean length of stay 10.3 + 6.5 days (range, 5 - 30 days).  The authors concluded that rheolytic thrombectomy can be performed effectively in patients with massive PE.  However, a large portion of the patients in this study underwent adjuvant overnight thrombolytic infusion.  Further evaluation in a larger cohort of patients is warranted to assess whether this treatment may offer an alternative or complement to thrombolysis or surgical thrombectomy.

The AngioJet is being evaluated for its potential use in the management of patients with deep vein thrombosis.  However, there is insufficient evidence to support its use for this indication.  Bush, et al. (2004) describe a new method of thrombus removal, with simultaneous percutaneous mechanical thrombectomy (PMT) by means of the AngioJet and thrombolysis in treating symptomatic lower extremity deep venous thrombosis.  These investigators reported that complete thrombus removal was obtained in 15 procedures (65%), and partial resolution in the remaining 8 procedures (35%).  The investigators concluded, however, that further outcome measures are needed to examine the effectiveness of this treatment method on preservation of valve function, reduction of chronic venous insufficiency, and improvement in quality of life.

There have been a number of case reports (Siablis, et al., 2005; Greenberg, et al., 2005; Sternbergh, et al., 2000) of the use of the AngioJet thrombectomy catheter for the percutaneous treatment of acute renal-artery thrombosis.  However, the effectiveness of Angiojet for this indication needs to be validated by prospective clinical trials.

Current risk of inadequate myocardial perfusion for thrombus embolization in primary coronary interventions is not negligible.  Margheri et al (2006) evaluated the safety and effectiveness of the AngioJet coronary device in patients with acute myocardial infarction (AMI).  The AngioJet device was used in 116 consecutive patients with AMI and angiographic evidence of extensive thrombosis in a vessel with a reference diameter of greater than 2.5 mm.  Glycoprotein IIb/IIIa inhibitors and stents were used.  Epicardial and myocardial re-perfusion angiographic parameters, and in-hospital major adverse cardiac events (MACE, i.e., cardiac death, myocardial infarction, target vessel re-vascularization) were assessed.  The AngioJet was successfully used in all patients.  Angiographic analysis showed that the AngioJet significantly improved epicardial coronary flow (p < 0.01), frame count (p < 0.01) and myocardial blush (p < 0.01), while stenting yielded significant improvements only in diameter stenosis, minimum lesion diameter and correlated vessel parameters (p < 0.01).  In-hospital MACE were uncommon (9 [8 %]).  When compared to an AMI population with similar thrombus burden but not undergoing thrombectomy, the AngioJet population showed significant improvement of re-perfusion parameters.  Moreover, there was greater AngioJet benefit in the high versus moderate thrombus burden subset; laboratory and operator experience also correlated significantly with final angiographic results.  The authors concluded that the findings of this study supports the favorable risk-benefit profile of AngioJet device use in selected patients with AMI when it is employed in experienced laboratories and by trained operators.

On the other hand, De Luca et al (2007) stated that the benefits of adjunctive mechanical devices to prevent distal embolization in patients with AMI are still a matter of debate.  In a meta-analysis, these researchers combined data from all randomized studies conducted with adjunctive mechanical devices to prevent distal embolization in AMI.  A total of 21 studies with 3721 patients were included (1877 patients [50.4 %] in the adjunctive mechanical device group and 1844 [49.6 %] in the control group); 1502 patients (40.3 %) were randomized in trials with distal protection devices, and 2219 patients (59.7 %) were randomized in trials with thrombectomy devices.  Adjunctive mechanical devices were associated with a higher rate of post-procedural thrombolysis in myocardial infarction (TIMI) 3 flow (89.4 % versus 87.1 %, p = 0.03), a significantly higher rate of post-procedural myocardial blush grade 3 (48.8 % versus 36.5 %, p < 0.0001), and less distal embolization (6.0 % versus 9.3 %, p = 0.008), without any benefit in terms of 30-day mortality (2.5 % versus 2.6 %, p = 0.88).  No difference was observed in terms of coronary perforations (0.27 % versus 0.07 %, p = 0.24).  The authors concluded that this meta-analysis demonstrates that, among patients with AMI treated with percutaneous coronary intervention, the use of adjunctive mechanical devices to prevent distal embolization is associated with better myocardial perfusion and less distal embolization, but without an apparent improvement in survival.

Chauhan and Kawamura (2007) noted that pulmonary embolism (PE) is a common cardiovascular disease with significant mortality.  Some patients with large PE are not eligible for current treatment options such as thrombolysis or surgical embolectomy.  These investigators reported their experience of percutaneous rheolytic thrombectomy (PRT) using the AngioJet system combined with adjunctive local thrombolytic therapy and inferior vena cava (IVC) filter placement to treat massive or sub-massive PE in patients ineligible for current treatment options.  Of the 14 consecutive patients ineligible for thrombolysis or embolectomy treated with PRT, 10 patients had massive PE (6 patients were hypotensive and 4 patients had intractable hypoxemia) and 4 patients had sub-massive PE.  Adjunctive local thrombolysis was performed in 5 patients.  An IVC filter was placed in 11 patients.  Angiographic success based on Miller score was achieved in 13 patients (92.9 %).  Procedure success was seen in 12 patients (85.7 %). Procedural mortality occurred in 1 patient (7.1 %) who presented in cardiogenic shock and non-fatal hemoptysis occurred in 1 patient (7.1 %).  Total in-hospital mortality occurred in 3 patients (21.4 %).  On a mean follow-up of 9 months, all 11 survivors had noted significant improvement in symptoms without recurrence.  The authors concluded that percutaneous rheolytic thrombectomy using the AngioJet may be a treatment option for patients with massive or sub-massive PE who may not be eligible for thrombolytic therapy or surgical embolectomy.