Despite diagnostic improvements and advances in medical therapy, acute massive pulmonary embolism accounts for approximately 50,000 deaths per year in the United States. During the past three decades, the mortality rate did not decline. Patients are at highest risk of death within the first hours of onset due to right ventricular failure. Survival depends on rapid recanalization of the pulmonary arterial obstruction and reduction of the right ventricular afterload. In a number of cases, thrombolytic therapy may fail to achieve this therapeutic goal in time.
Percutaneous catheter treatment may represent an additional option for high-risk patients, in terms of a synergistic adjunct to thrombolysis as well as an alternative to surgical embolectomy. Different concepts of percutaneous treatment include catheter embolectomy and embolus breakup with standard diagnostic and balloon catheters.
In the present study, a new percutaneous technique was evaluated, based on a rotatable pigtail catheter that can be used for pulmonary angiography and mechanical embolus fragmentation. Following experimental assessment and a successful first clinical application, the results of a phase I clinical multicenter study are presented.
Materials and Methods
Fragmentation Catheter System
The fragmentation catheter device (Schmitz-Rode T, Gunther RW. Apparatus for fragmentation of a lung embolus. German patent DE G 9409863.8, US patent 5,630,823, PCT WO 95/35066) (William Cook Europe A/S; Bjaerverskov, Denmark) consisted of a coaxial combination of catheter and sheath. The nylon catheter with a 5F high-torque shaft had a radiopaque pigtail tip with an outer diameter of not more than 8 mm. In the outer curvature of the pigtail loop an oval side hole was arranged in straight projection to the axis of the catheter shaft, allowing passage of a guide wire (Fig 1, top). In the distal shaft portion, six small standard sideholes were arranged for delivery of contrast medium or thrombolytic agent Here flovent inhalers. Four centimeters of the distal shaft of the catheter were curved 90°, with upturned pigtail for femoral and downturned pigtail for jugular access, hence facilitating improved probing of the right ventricle. The femoral version had a length of 115 cm, the jugular 105 cm, respectively.