Thomas B. Kinney

Coaxial balloon dilation and calibration of urethral strictures.

New coaxial balloon dilators with standard urologic tip configurations have been designed for use in urethral strictures. Balloon dilatation provides several advantages over conventional dilatation of strictures including improved access and decreased mucosal trauma due to a low silhouette, adjustability of diameter and rigidity, decreased instrumentation, and facilitation of intermittent self-dilation by the patient. The instruments were evaluated in 51 strictures (41 patients) as both a dilator and a calibrator. All catheters were located across the stricture easily (although two required filiform attachments). All clinical goals were achieved, and no complications were identified. Two patients were started on a program of intermittent self-dilation after internal urethrotomy with good results. It is our initial clinical impression that slow, gradual dilation of strictures is superior to rapid, abrupt dilation. This can only be practically achieved with balloon dilators.

Intraoperative coronary artery balloon-catheter dilatation

A new transluminal angioplasty catheter based on linear extrusion of the dilating element has been specifically designed and developed for the cardiac surgeon. This catheter facilitates placement of the dilating balloon within the arterial narrowing without the routine use of fluoroscopy in the operating room. Physical measurements of the frictional forces exerted on the inner arterial surfaces by three different angioplasty catheter designs during advancement show that the linear extrusion catheter consistently minimizes these forces. The linear extrusion catheters have now been used in over 64 coronary adjunctive intraoperative dilatations. The results of these clinical studies and our research data indicate that the linear extrusion balloon catheter is a safe and effective adjunct to primary coronary artery bypass procedures.

Current status of dilatation catheters and guiding systems

New transluminal angioplasty catheters based upon the linear extrusion of the dilating element have been developed to facilitate placement of the dilating balloon within the arterial narrowing. In a multicenter study, the use of linear extrusion catheters has been shown to be safe and effective in adjunctive intraoperative peripheral dilatations. Physical measurements of the frictional forces exerted on the inner arterial surfaces during advancement of 3 angioplasty catheter designs show that the linear extrusion catheter consistently minimizes these forces. The use of a secondary guiding sheath in conjunction with a linear extrusion catheter provides additional directional capability. A secondary guiding sheath with a side port has recently been developed that allows access to difficult-to-cannulate vessels. The favorable results of the clinical studies and research data justify an ongoing evaluation of these concepts in percutaneous dilatation procedures and in intraoperative coronary procedures.