Catheter for Portable Lung Assist Device

Abstract

The present invention relates to a catheter that minimizes or eliminates the recirculation of oxygenated blood. The catheter of the present invention can be used to drain blood from multiple points in the patient, namely the superior vena cava, right atrium, and the right ventricle, while returning blood to the patient's pulmonary artery. Further, the catheter of the present invention is less likely to be moved or dislodged than catheters currently available in the art, thus making the catheter particularly useful for portable lung assist devices. The present invention also relates to methods for inserting the catheter into the patient and using the catheter with a lung assist device.

What is claimed is: 
     
         1 . A catheter comprising:
 a first tube having a proximal end, a distal end, and a length therebetween, and a lumen within the length of the first tube with at least one opening to the lumen near the distal end;   a second tube having a proximal end, a distal end, and a length therebetween, and a lumen within the length of the second tube with at least one opening to the lumen at the distal end; and   a preformed curvature near the distal end of the first tube and along the length of the second tube;   wherein at least one of the openings of the first tube resides within the curvature, and wherein the distance of the at least one opening in the first tube residing in the curvature relative to the at least one opening in the distal end of the second tube is such that when the catheter is positioned in a subject's heart, the at least one opening in the first tube is positionable in the right ventricle while the at least one opening of the second tube is positionable in the pulmonary artery.   
     
     
         2 . The catheter of  claim 1 , wherein the distal end of the second tube extends 50 to 150 mm past the most distal opening of the first tube. 
     
     
         3 . The catheter of  claim 1 , wherein at least one of the openings of the first tube is positionable in the superior vena cava when the catheter is positioned in the subject's heart. 
     
     
         4 . The catheter of  claim 1 , wherein at least one of the openings of the first tube is positionable in the right atrium when the catheter is positioned in the subject's heart. 
     
     
         5 . The catheter of  claim 1 , wherein the curvature of the catheter comprises a vertex or inflection point positioned 130 to 170 mm from the distal end of the second tube. 
     
     
         6 . The catheter of  claim 1 , wherein the distal end of the first tube is positioned at the vertex or inflection point of the curvature of the catheter. 
     
     
         7 . The catheter of  claim 1 , wherein the catheter is sized for blood flow in the range of about 3 to 4 L per minute. 
     
     
         8 . The catheter of  claim 1 , wherein at least a portion of the first tube is reinforced with wire. 
     
     
         9 . The catheter of  claim 1 , wherein at least a portion of the second tube is reinforced with wire. 
     
     
         10 . The catheter of  claim 1 , further comprising a means for measuring pressure in the patient's heart. 
     
     
         11 . The catheter of  claim 10 , wherein the means for measuring pressure comprises at least one pressure measuring lumen. 
     
     
         12 . The catheter of  claim 1 , wherein the curvature is between 110° and 120°. 
     
     
         13 . A method for supporting a failing right ventricle in a subject, comprising:
 inserting a catheter into a subject, the catheter comprising a first tube having at least one opening connected to a lumen within, a second tube having at least one opening connected to a lumen within, and a preformed curvature, such that the catheter enters the subject's heart via the superior vena cava, passes through the right atrium, enters the right ventricle wherein the first tube terminates, and the curvature extends the second tube into the pulmonary artery;   draining blood from the subject's right ventricle via the first tube; and   pumping the blood to the subject's pulmonary artery via the second tube.   
     
     
         14 . The method of  claim 13 , wherein the first and second tubes run substantially parallel to each other along at least a portion of the length of the catheter. 
     
     
         15 . The method of  claim 13 , wherein the first tube and second tube are coaxial along at least a portion of the length of the catheter. 
     
     
         16 . The method of  claim 13 , wherein blood is also drained from the subject's superior vena cava via the first tube. 
     
     
         17 . The method of  claim 13 , wherein blood is also drained from the subject's right atrium via the first tube. 
     
     
         18 . The method of  claim 13 , wherein the blood is oxygenated prior to pumping the blood to the subject's pulmonary artery via the second tube. 
     
     
         19 . The method of  claim 18 , wherein the blood is oxygenated using an extra-corporeal membrane oxygenation (ECMO) device. 
     
     
         20 . The method of  claim 13 , wherein the catheter is inserted into the subject using a guiding mechanism selected from the group consisting of: a guide wire, an X-ray guidance system, and an ultrasound guidance system.