Stent installation method using balloon catheter having stepped compliance curve

• US 6,352,551 B1
• Filed: 11/08/2000
• Issued: 03/05/2002
• Est. Priority Date: 03/02/1995
• Status: Expired due to Term

• Current Assignee: Boston Scientific Scimed, Inc. (Boston Scientific Corporation)
• Original Assignee: Scimed Life Systems Incorporated (Boston Scientific Corporation)
• Inventors: Wang, Lixiao
• Primary Examiner(s): Recla, Henry J.
• Assistant Examiner(s): HO, TAN-UYEN THI
• Application Number:
  US09/709,033
• Time in Patent Office: 482 Days
• Field of Search: 606/108, 606/190-200, 623/1.11, 623/1.34, 623/12, 604/96.01, 604/101.01, 604/101.02, 604/101.04, 604/103.06, 604/103.07, 604/103.08, 604/103-1-1
• US Class Current: 623/1.11
• CPC Class Codes: A61F 2/958 Inflatable balloons for placing stents or stent-grafts
• CPC Class Codes: A61F 2250/0039 differing in diameter
• CPC Class Codes: A61M 2025/1059 having different inflatable sections mainly depending on the response to the inflation pressure, e.g. due to different material properties
• CPC Class Codes: A61M 2025/1075 having a balloon composed of several layers, e.g. by coating or embedding
• CPC Class Codes: A61M 25/10 Balloon catheters A61M25/0125 takes precedence; embolectomy A61B17/22032; retractors A61B17/02; inflatable balloons for placing stents or stent-grafts A61F2/958 ; stomach balloons for treatment of obesity A61F5/0003; oesophagal tubes A61J15/00
• CPC Class Codes: A61M 25/1002 characterised by balloon shape A61M25/1006, A61M25/1009 take precedence
• CPC Class Codes: A61M 25/1029 Production methods of the balloon members, e.g. blow-moulding, extruding, deposition or by wrapping a plurality of layers of balloon material around a mandril
• CPC Class Codes: A61M 25/104 used for angioplasty

Abstract

A method for installing a stent in a vessel utilizes a single balloon catheter for both low pressure predilation at a relatively small diameter to open the lesion sufficiently to allow insertion and deployment of the stent across the lesion and for subsequent high pressure embedding of the stent in the vessel wall. The same balloon catheter may also be employed to insert and deploy the stent. The balloons utilized in the method have a stepped compliance curve which allows for predilation at a low pressure and predetermined diameter and for high pressure embedding at a substantially larger diameter. The balloons may be provided with a configuration in which only a portion of the balloon has a stepped compliance curve while a further portion has a generally linear compliance profile. With such balloons high pressure treatment of the vessel wall areas not reinforced by the stent can be avoided despite the occurence of longitudinal shrinkage of the stent during expansion thereof.

Claims

1. A balloon for use on a catheter, the balloon having an inflatable balloon body comprising first, second and third sequentially adjacent longitudinal body portions, the balloon body being located between first and second end regions and having been formed by a radial expansion process at elevated temperature wherein a preform was blown to a configuration wherein each said body portion and each end region had a respective blown diameter, the body portion diameters having been greater than the end region diameters, each said balloon body portion formed a step, and the second body portion blown diameter having been greater than the first and third body portion blown diameters.

2. A balloon as in claim 1 wherein the blown diameters of the balloon first and third body portions were substantially equal.

3. A balloon as in claim 1 wherein the lengths of the first and third body portions are substantially equal and the length of the second body portion is approximately twice the length of the first body portion.

4. A balloon as in claim 1 wherein, after having been blown, the second body portion was shrunk to a reduced diameter approximately equal to the blown diameter of the first body portion by annealing the second body portion at a temperature and pressure which caused the balloon material to shrink.

5. A balloon as in claim 1 made of a thermoplastic polymer selected from the group consisting of polyesters, nylons, thermoplastic polyimides and thermoplastic polyurethanes.

6. A balloon as in claim 5 made of a polyester selected from poly(ethylene terephthalate) and poly(ethylene napthalenedicarboxylate).

7. A balloon as in claim 1 having a burst pressure of greater than 15 atm and a compliance curve according to which the balloon expands at a rate of no more than 0.1 mm/atm from 15 atm to burst.

8. A balloon as in claim 7 wherein according to said compliance curve the balloon expands at a rate no more than is no more than 0.06 mm/atm from 15 atm to burst.

9. A balloon as in claim 1 having a wall strength of at least 18,000 psi.

10. A balloon as in claim 9 wherein said wall strength is greater than 20,000 psi.