Antimicrobial tympanostomy tube

• US 6,361,526 B1
• Filed: 04/12/1999
• Issued: 03/26/2002
• Est. Priority Date: 11/01/1993
• Status: Expired due to Term

• Current Assignee: Medtronic Xomed Incorporated (Medtronic Plc)
• Original Assignee: Medtronic Xomed Incorporated (Medtronic Plc)
• Inventors: Hissong, James B., Reisdorf, Dennis J.
• Primary Examiner(s): KENNEDY, SHARON E
• Application Number:
  US09/291,151
• Time in Patent Office: 1,079 Days
• Field of Search: 604/265, 604/266, 604/523, 604/264, 604/890.1, 604/514, 604/506, 604/285, 604/540, 604/541, 623/1, 623/10-12, 623/1.1, 623/1.42, 623/1.45, 606/109, 606/161, 606/162, 424/437, 424/422, 424/423, 424/486, 424/617-618, 514/956
• US Class Current: 604/265
• CPC Class Codes: A61F 11/202 Surgical middle-ear ventilation or drainage, e.g. permanent; Implants therefor

Abstract

An antimicrobial tympanostomy tube used to alleviate bacteriostatic infections following myringotomy which is compatible with otologic tissue associated with the middle ear. The tube is formed from a microporous thermoplastic or thermoset resin having incorporated therein 0.5 to about 15% by weight of a silver compound capable of migrating to the surface of tube sidewalls to impart a therapeutically effective level of antibacterial activity throughout the sidewall surface so as to provide long-term prevention of infections which may otherwise result during or after surgery or implantation of the tube.

Claims

1. A tympanostomy tube having a sidewall and flange formed of a microporous resin cured to form a gas-permeable matrix containing a homogeneous dispersion of particles of a silver compound capable of migrating to the surface of said tympanostomy tube to provide antimicrobial activity, said tympanostomy tube being produced by the process steps of

mixing a microporous, gas-permeable elastomeric resin with a concentration of about 0.5 to about 15% by weight of a silver compound in the form of particles having an average particle size of about 5 to about 100 microns;

forming the mixture into a tympanostomy tube having a sidewall and flange; and

post curing the tympanostomy tube whereby the silver compound is capable of migrating to the surface of the tympanostomy tube via pores in the resin.

2. A tympanostomy tube as recited in claim 1 wherein said resin is a silicone resin.

3. A tympanostomy tube as recited in claim 2 wherein said resin is a silicone gum resin in the form of a paste and further comprising the step of milling the mixture to uniformly disperse the silver compound particles throughout the silicone paste.

4. A tympanostomy tube as recited in claim 3 wherein said post curing step is performed at a temperature of about 120°

centigrade for a period of about 1.5 hours.