Ureteral stent-catheter having varying internal diameter and method of use

Claim 1

A unitary, flexible ureteral stent for implantation in a ureteral meatus, comprising: a flexible tubular drain passage segment having a plurality of drain passages and a first fluid passage channel extending substantially the entire length of said drain passage segment, said channel communicating with the outside of said drain passage segment, said first fluid passage channel having a first channel width, one end of said drain passage segment being closed and a portion of said passage segment forming a preformed curl; and a flexible tubular ureteral catheter receiving segment having a second fluid passage channel extending the entire length thereof, said catheter receiving segment being collinearly integral with said passage segment, with said second fluid passage channel also being collinear with said first fluid passage channel, said second passage channel having a second channel width, said second channel width being larger than said first channel width, wherein a portion of said catheter receiving segment forming another preformed curl, and wherein said length of said drain passage segment being substantially longer than said catheter receiving segment.

Claim 25

A method of inserting an elongated flexible ureteral stent into a renal pelvis comprising the steps of: inserting a stiff tubular ureteral catheter into a ureteral catheter receiving segment of an elongated flexible ureteral stent having preformed set curls at both ends thereof, said stent having a flexible tubular drain passage segment having a plurality of drain passages and a first fluid passage channel extending substantially the entire length of said drain passage segment, said channel communicating with the outside of said drain passage segment, said drain passage segment having a first outer width and said first fluid passage channel having a first channel width, one end of said drain passage segment being closed and a portion of said passage segment forming one of said preformed curls; and said ureteral catheter receiving segment having a second fluid passage channel extending the entire length thereof, said catheter receiving segment being collinearly integral with said passage segment, with said second fluid passage channel also being collinear with said first fluid passage channel, said catheter receiving segment having a second outer width, said second passage channel having a second channel width, said second channel width being larger than said first channel width, wherein a portion of said catheter receiving segment forming the other preformed curl, and wherein said length of said drain passage segment being substantially longer than said catheter receiving segment, to straighten the other curl formed in the distal end; inserting a stiffening wire through said catheter and said stent through said second channel to straighten the curl formed in the drain passage segment of said stent; inserting the stent-catheter combination through a cystoscope until the proximal end of the stent is within a renal cavity; withdrawing the stiffening wire from the stent-catheter combination thereby allowing the preformed curl at said proximal end to reform and thus allowing the device to function as an externalized ureteral catheter; and extracting said catheter, allowing the preformed distal curl of the stent to reform to maintain the stent in the renal pelvis.

Claim 26

A method of inserting an elongated flexible ureteral stent into a renal pelvis comprising the steps of: inserting a stiff tubular ureteral catheter into a ureteral catheter receiving segment of an elongated flexible ureteral stent having preformed set curls at both ends thereof, said stent having a flexible tubular drain passage segment having a plurality of drain passages and a first fluid passage channel extending substantially the entire length of said drain passage segment, said channel communicating with the outside of said drain passage segment, said drain passage segment having a first outer width and said first fluid passage channel having a first channel width, one end of said drain passage segment being closed and a portion of said passage segment forming one of said preformed curls; and said ureteral catheter receiving segment having a second fluid passage channel extending the entire length thereof, said catheter receiving segment being collinearly integral with said passage segment, with said second fluid passage channel also being collinear with said first fluid passage channel, said catheter receiving segment having a second outer width, said second passage channel having a second channel width, said second channel width being larger than said first channel width, wherein a portion of said catheter receiving segment forming the other preformed curl, and wherein said length of said drain passage segment being substantially longer than said catheter receiving segment, to straighten the other curl formed in the distal end; inserting a stiffening wire through said catheter and said stent through said second channel to straighten the curl formed in the drain passage segment of said stent; inserting the stent-catheter combination through a cystoscope until the proximal end of the stent is within a renal cavity; withdrawing the stiffening wire from the stent-catheter combination thereby allowing the preformed curl at said proximal end to reform and thus allowing the device to function as an externalized ureteral catheter; and extracting said catheter, allowing the preformed distal curl of the stent to reform to maintain the stent in the renal pelvis.