Intravascular catheter

A catheter for insertion into blood vessels, said catheter comprising a flexible tube having an outer diameter of no more than about 0.05 inch, said flexible tube defining proximal and distal ends and having outer and inner tubular layers, said inner tubular layer surrounding a catheter lumen and comprising a chemically inert, fluorinated polymer;

• said flexible tube carrying a helical reinforcement member embedded within said tube adjacent a distal end of said catheter, said helical reinforcement member being spaced from a proximal end portion of said catheter, said proximal end portion comprising at least about half of the catheter length, said proximal end portion comprising said tube embedded along most of its length with a crossing-strand, tubular reinforcement member;
• said proximal end portion defining a softer, distally positioned portion that comprises a softer plastic material than other portions of said proximal end portion;
• said catheter having, adjacent to and distal of said proximal end portion, an integrally attached, second tubular wall portion comprising part of said flexible tube and which carries some of said embedded helical reinforcement member and, distal to said second tubular wall portion, an integrally attached third tubular wall portion comprising part of said flexible tube and which carries some of said embedded, helical reinforcement member, said catheter having, distal to said third tubular wall portion, an integrally attached, fourth tubular wall portion comprising part of said flexible tube and comprising a tubular plastic material which is softer than the corresponding tubular plastic materials positioned proximal to said fourth tubular wall portion, said fourth tubular wall portion carrying some of said embedded helical reinforcement member, said proximal end portion having a larger outer diameter then said fourth portion.