System and method for positioning implantable medical devices within coronary veins

Abstract

An improved system and method for placing implantable medical devices (IMDs) such as leads within the coronary sinus and branch veins is disclosed. In one embodiment, a slittable delivery sheath and a method of using the sheath are provided. The sheath includes a slittable hub, and a substantially straight body defining an inner lumen. The body comprises a shaft section and a distal section that is distal to, and softer than, the shaft section. A slittable braid extends adjacent to at least a portion of one of the shaft section and the distal section. In one embodiment of the invention, the sheath further includes a transition section that is distal to the shaft section, and proximal to the distal section. The transition section is softer than the shaft section, but stiffer than the distal section.

1 - 37 . (canceled) 
     
     
         38 . A system for positioning implantable medical devices within the coronary sinus or a branch vein thereof, comprising:
 a substantially straight slittable sheath comprising a central lumen, a shaft section, and a distal section that is distal to, and softer than, the shaft section, the sheath further comprising a slittable braid adjacent to at least a portion of at least one of the shaft section and the distal section;   a balloon catheter adapted to be inserted within the central lumen of the sheath, the balloon catheter comprising an elongated shaft defining an inner lumen; and   a steerable catheter having a shaft adapted to be inserted within the inner lumen of the balloon catheter.   
     
     
         39 . The system of  claim 38 , wherein the balloon catheter further comprises an inflation lumen and an occlusion balloon fluidly coupled to the inflation lumen. 
     
     
         40 . The system of  claim 38 , wherein the elongated shaft of the balloon catheter has an outer diameter ranging from approximately 0.050 to 0.100 inches. 
     
     
         41 . The system of  claim 38 , wherein the elongated shaft of the balloon catheter has an outer diameter of approximately 0.074 inches. 
     
     
         42 . The system of  claim 38 , wherein the inner lumen of the balloon catheter has an inner diameter ranging from approximately 0.030 to 0.080 inches. 
     
     
         43 . The system of  claim 38 , wherein the balloon catheter further comprises a heat shrink tubing disposed on an outer surface of a shaft proximal section. 
     
     
         44 . The system of  claim 38 , wherein the balloon catheter further comprises a distal tip disposed at a distal end of the elongated shaft, and wherein the distal tip is formed of a flexible polymeric material. 
     
     
         45 . The system of  claim 44 , wherein the distal tip of the balloon catheter is radiopaque. 
     
     
         46 . The system of  claim 38 , wherein the balloon catheter further comprises a distal tip, a distal section, and a proximal section, and wherein a total length of the distal tip, the distal section and the proximal section is approximately 50 to 90 centimeters. 
     
     
         47 . The system of  claim 38 , wherein the balloon catheter comprises PEBAX tubing having a hardness ranging from approximately 60D to 80D (Shore). 
     
     
         48 . The system of  claim 38 , wherein the balloon catheter further comprises an occlusion balloon having an inflated diameter ranging from approximately 0.2 to 1.0 inches. 
     
     
         49 . The system of  claim 48 , wherein the occlusion balloon has a wall thickness ranging from approximately 0.002 to 0.006 inches. 
     
     
         50 . The system of  claim 48 , wherein the occlusion balloon has length ranging from approximately 6 to 14 millimeters. 
     
     
         51 . A catheter assembly for positioning implantable medical devices within the coronary sinus or a branch vein thereof comprising:
 a sheath apparatus comprises a substantially straight slittable sheath extending from a proximal end to a distal end defining an inner lumen, wherein the slittable sheath comprises a shaft section, a distal section distal to the shaft section at the distal end of the sheath, wherein the distal section comprises a soft tip extending from a transition location along the distal section to the distal end of the sheath, and a slittable braid extending along the shaft section and at least a portion of the distal section, and an internal liner adjacent at least a portion of the inner lumen and extending along the shaft section and terminating within the distal section of the sheath beyond the distal end of the slittable braid;   a balloon catheter adapted to be inserted within the central lumen of the sheath, the balloon catheter comprising an elongated shaft defining an inner lumen and a balloon disposed along the elongated shaft; and   a steerable catheter having a shaft adapted to be inserted within the inner lumen of the balloon catheter.   
     
     
         52 . The assembly of  claim 51 , wherein the balloon catheter further comprises a distal tip disposed at a distal end of the elongated shaft, and wherein the distal tip is formed of a flexible polymeric material. 
     
     
         53 . A method for seating an implantable medical device within a coronary sinus or branch vein of a patient, the method comprising:
 a.) providing a slittable sheath having a substantially straight sheath body defining a central lumen, wherein the sheath body comprises:
 a shaft section and a distal section, wherein the shaft section is formed of a first material and the distal section is formed of a second material, and wherein the first material is more rigid than the second material; and 
 a slittable braid extending adjacent to at least a portion of one of the shaft section and the distal section; 
   b.) inserting a balloon catheter within the central lumen of the slittable sheath, the balloon catheter comprising defining an inner lumen;   c.) inserting a steerable catheter within the inner lumen of the balloon catheter;   d.) positioning the slittable sheath, the balloon catheter, and the steerable catheter within a passageway of the patient; and   e.) navigating the slittable sheath, the balloon catheter, and the steerable catheter into the coronary sinus.   
     
     
         54 . The method of  claim 53 , wherein step e.) comprises:
 advancing a distal end of the steerable catheter beyond a distal end of the slittable sheath;   cannulating the coronary sinus with the steerable catheter; and   withdrawing the steerable catheter from the coronary sinus.   
     
     
         55 . The method of  claim 53 , and further comprising:
 obtaining a venogram; and   withdrawing the balloon catheter from the central lumen of the slittable sheath.   
     
     
         56 . The method of  claim 53 , and further comprising:
 f.) advancing an implantable medical device within the central lumen of the slittable sheath.   
     
     
         57 . The method of  claim 56 , wherein the step f) further comprises:
 advancing a navigational device within the central lumen of the slittable sheath.