Tissue puncture assemblies and methods for puncturing tissue

Abstract

A tissue puncture assembly includes an elongate tubular member having a lumen, a distal portion having a side wall, a side port opening extending through the side wall and, and a guiding surface having a distal end that extends adjacent to a distal edge of the side port opening. The tissue puncture assembly further includes a flexible puncture member insertable through the lumen of the elongate tubular member. The flexible puncture member deflects upon contacting the guiding surface to exit the elongate tubular member through the side port in a lateral direction relative to a longitudinal direction of the elongate tubular member. The tissue puncture member is capable of puncturing tissue at an oblique angle. The tissue puncture member may further adopt a pre-formed shape at its distal end to prevent inadvertent puncture of tissue and to maintain access to the puncture site. The transseptal puncture assembly may include various sensors to identify tissue structures and precisely locate the desired puncture site.

What is claimed is: 
     
         1 . A medical device comprising:
 an elongate tubular member having a lumen extending therethrough in a longitudinal direction, wherein the elongate tubular member comprises
 a distal portion having a wall; 
 a port opening extending through the wall, the port opening having a distal edge and a proximal edge; and 
 a guiding surface within the lumen of the elongate tubular member, the guiding surface having a distal end, wherein the distal end of the guiding surface extends adjacent to the distal edge of the port opening; and 
   a flexible puncture member insertable through the lumen of the elongate tubular member, the flexible puncture member having a distal portion and a proximal portion,   wherein the flexible puncture member deflects upon contacting the guiding surface to exit the elongate tubular member through the port opening, and   wherein the distal portion of the flexible puncture member is biased into an atraumatic shape upon exiting the elongate tubular member.   
     
     
         2 . The medical device according to  claim 1 , wherein the distal portion of the flexible puncture member is straightenable for insertion within the elongate tubular member. 
     
     
         3 . The medical device according to  claim 1 , wherein the flexible puncture member comprises a shape-memory alloy. 
     
     
         4 . The medical device according to  claim 1 , wherein the flexible puncture member further comprises a lumen extending therethrough. 
     
     
         5 . The medical device according to  claim 4  further comprising a guidewire insertable through the lumen of the flexible puncture member. 
     
     
         6 . The medical device according to  claim 1 , wherein the distal portion of the elongate tubular member further comprises at least one electrode coupled to an impedance-measuring circuit. 
     
     
         7 . The medical device according to  claim 1 , wherein the distal portion of the elongate tubular member further comprises at least one thermal sensor coupled to a temperature-measuring circuit. 
     
     
         8 . The medical device according to  claim 1 , wherein the port opening defines an outer perimeter, and wherein the outer perimeter of the port opening comprises at least one of an electrode or a thermal sensor. 
     
     
         9 . The medical device according to  claim 1 , wherein the distal portion of the elongate tubular member further comprises at least one intravascular ultrasound sensor coupled to an image processor. 
     
     
         10 . The medical device according to  claim 1 , wherein the distal portion of the elongate tubular member further comprises a plurality of ultrasound transducers in a phased array. 
     
     
         11 . The medical device according to  claim 10 , wherein the plurality of ultrasound transducers are arranged in a linear phased array parallel to the longitudinal direction of the elongate tubular member. 
     
     
         12 . The medical device according to  claim 10 , wherein the plurality of ultrasound transducers are arranged radially about the distal portion of the elongate tubular member in a circular phased array. 
     
     
         13 . The medical device according to  claim 1 , wherein the distal portion of the elongate tubular member further comprises at least one ultrasound transducer, and wherein the at least one ultrasound transducer or a reflective surface which deflects the signal from the ultrasound transducer is rotatable relative to an axis of the elongate tubular member. 
     
     
         14 . The medical device according to  claim 1 , wherein the port opening is positioned on the wall of the distal portion of the elongate tubular member such that the flexible puncture member exits therefrom in a lateral direction relative to the longitudinal direction of the elongate tubular member. 
     
     
         15 . A medical device comprising:
 an elongate tubular member having a lumen extending therethrough in a longitudinal direction, wherein the elongate tubular member comprises
 a distal portion having a wall; 
 a port opening extending through the wall, the port opening having a distal edge and a proximal edge; and 
 a guiding surface within the lumen of the elongate tubular member, the guiding surface having a distal end, wherein the distal end of the guiding surface extends adjacent to the distal edge of the port opening; and 
   a flexible puncture member insertable through the lumen of the elongate tubular member, the flexible puncture member having a distal portion and a proximal portion,   wherein the flexible puncture member deflects upon contacting the guiding surface to exit the elongate tubular member through the port opening, and   wherein the distal portion of the flexible puncture member automatically adopts a first shape configured to puncture tissue upon exiting the elongate tubular member and a second shape configured to be atraumatic after the puncture member is fully extended.   
     
     
         16 . The medical device according to  claim 15 , wherein the second shape anchors the flexible puncture member in place. 
     
     
         17 . A method for puncturing the pericardial sac, comprising:
 providing a flexible puncture member contained within a lumen of an elongate tubular member, the elongate tubular member comprising a guiding surface within the lumen and a distal portion having a distal tip and a side port opening, and;   inserting the elongate tubular member containing the flexible puncture member into a patient via a subxiphoid percutaneous approach;   urging the distal tip of the elongate tubular member against the pericardial sac so that at least a portion of the pericardial sac is adjacent the side port opening;   advancing the flexible puncture member through the elongate tubular member, wherein the flexible puncture member deflects upon contacting the guiding surface to exit the side port in a lateral direction relative to a longitudinal direction of the elongate tubular member;   puncturing the portion of the pericardial sac adjacent the side port opening with the flexible puncture member; and   advancing the flexible puncture member through the pericardial sac and into the pericardial space.   
     
     
         18 . The method according to  claim 17 , wherein during the advancing step, a distal end of the flexible puncture member adopts a pre-formed shape and becomes anchored within the pericardial space. 
     
     
         19 . The method according to  claim 17  further comprising:
 advancing the elongate tubular member over the flexible puncture member and into the pericardial space. 
 
     
     
         20 . The method according to  claim 19  further comprising:
 inserting a guidewire through a lumen of the flexible puncture member and into the pericardial space; and 
 withdrawing the elongate tubular member and the flexible puncture member.