Catheters, cannulas, or catheter sheath introducers, having hemostasis valves which are mounted on a housing on the end of a catheter are well known in the art. Examples of a catheter sheath introducers are given in U.S. Pat. No. 4,000,739 issued to Stevens on Jan. 4, 1977, U.S. Pat. No. 4,895,565 issued to Hillstead on Jan. 23, 1990 and U.S. Pat. No. 5,417,665 issued to De La Mata et al. on May 23, 1995, all of which are hereby incorporated herein by reference. The catheters have a distal end for insertion into the patient and a proximal end which remains external of the patient. Such catheters are used to facilitate the introduction of other catheters and guidewires into the vascular system of a patient, while minimizing injury to the patient at the access site. For some procedures, such as percutaneous transluminal angioplasty, one or more catheters are inserted into and removed from the patient repeatedly.
The catheter introducer is usually inserted into the femoral or brachial artery of a patient. The presence of the catheter sheath introducer causes the trauma to the body to be limited to only one catheter entering at the body access site. All other catheters and guidewires pass through the catheter introducer, and thus are not traumatic to the body at the access site. Catheter sheath introducers typically have a hemostasis valve located within a housing at the proximal end. The valve can be made from a slit elastomeric partition or membrane. The valve is designed to seal against leakage of blood, as catheters and guidewires of varying diameters are passed therethrough.
When performing interventional procedures, such as PTCA or stent implantation, a guiding catheter is inserted through the catheter sheath introducer and placed adjacent the ostium of the artery. Thereafter, a balloon catheter or the like is inserted through the guiding catheter and delivered to a diseased portion of a coronary artery. During such procedures, the physician often realizes that a larger balloon catheter or stent is needed to treat the particular patient. This may necessitate the need for a larger guiding catheter. In addition to that situation, physicians often will perform diagnostic procedures using relatively small size diagnostic catheters, and thereafter perform interventional procedures with relatively large french size guiding catheters. Both of these procedures often necessitate the need for a larger catheter sheath introducer to accommodate for the larger size catheter. However, exchanging the catheter sheath introducer has many drawbacks, including increased trauma at the insertion site. In addition, exchanging catheter sheath introducers can cause an increase in the procedure time, resulting in additional patient discomfort and additional costs.
There has, therefore, been a need for a catheter sheath introducer, guiding catheter, trocar or the like, which has a shaft that can increase its diameter. There has also been a need to have such a catheter wherein the diameter of the shaft is permanently expanded. By permanently expanding the diameter, friction between the expanded shaft and devices passing therethrough, such as other catheters, decreases. In addition, if the shaft is not permanently expanded, it could damage devices, i.e. stents, balloons etc., as they are passed therethrough, and prevent the removal of such devices out of the shaft. Lastly, a permanently expanded shaft, gives the physician better torque-ability of the devices passing therethrough and allows the physician to do saline flushes. The present invention fulfills such needs.