Patent GB-1436679-A (GB)
Title: Method of making an inflatable balloon catheter
IPC: A61M25/00
Filed: 1974-03-14
Abstract: 1436679 Catheters BAXTER LABORATORIES INC 14 March 1974 [21 March 1973] 11358/74 Heading A5R A method of making an inflatable balloon catheter, by attaching an inflatable balloon catheter tip 26 to the distal end (46), Figure 8 (not shown) of a double lumen catheter shaft 11, the tip comprising a drainage section 30 and a balloon section 28, comprises the steps of covering, with a first heat-shrinkable sleeve (42) a portion of the shaft adjacent to but spaced from the distal end of the shaft, thereby leaving an exposed portion (44) of the shaft at the distal end of the shaft; heating the first sleeve to shrink it around the shaft; adhering a distal portion 40 of the balloon section to said exposed distal portion of the shaft; removing the first sleeve; covering, with a second heat-shrinkable sleeve (50); Figure 13 (not shown) a portion of the balloon section of the tip at a position adjacent to but spaced from the proximal end of the balloon section; and heating the second sleeve to shrink it around the balloon section and shaft. The method is continued by applying a curable adhesive 49 to the shaft between the second sleeve and the proximal end of the balloon section of the tip, covering, with a third heat-shrinkable sleeve (54), Figure 14 (not shown) the second sleeve and the proximal end of the balloon section in contact with the adhesive; heating the third sleeve to shrink it around the shaft and thereby form a smoothly tapering surface of the balloon section, adhesive and shaft at the junction of the proximal portion of the balloon section of the tip and the shaft; curing the adhesive in order to bond the proximal portion of the balloon section to the shaft; and removing the second and third sleeves. The distal portion of the balloon section may be adhered to the shaft by the steps of applying a curable adhesive 48 to the exposed distal portion (44) of the shaft, placing the distal portion of the balloon section in contact with the adhesive, and curing the adhesive. Alternatively the adhesive 48 may be applied after bringing together the distal portions of the balloon section and the shaft. The catheter shaft and tip may be made of silicone rubber and the adhesive may be a room temperature vulcanizing silicone rubber adhesive. The first, second and third heatshrinkable sleeves may be made of polyvinyl chloride capable of shrinking at temperatures of 500F to 800F. The adhesive may be cured by subjecting it to an atmosphere of 70F to 125F and a relative humidity of 30 to 70%. The exposed portion (44) of the shaft may be from <3>/32 to 1 inch in length, and the distance between the second sleeve and the proximal end of the balloon section may be from <1>/16 to  inch. In an alternative embodiment, Figures 16, 17 (not shown) a catheter tip (26a) differs from the tip 26 in that the balloon and drainage sections (28a, 30a) comprise a continuous thin silicone rubber layer extending distally to a more rigid head (31) at the end of the tip (26a). Drainage holes (32a) in this embodiment may be punched through the tip and shaft after the tip has been attached to the shaft.