Prosecution Insights
Last updated: April 19, 2026
Application No. 18/151,885

ELECTROSPUN PTFE COATED STENT AND METHOD OF USE

Final Rejection §DP
Filed
Jan 09, 2023
Examiner
DUKERT, BRIAN AINSLEY
Art Unit
3774
Tech Center
3700 — Mechanical Engineering & Manufacturing
Assignee
Merit Medical Systems Inc.
OA Round
2 (Final)
82%
Grant Probability
Favorable
3-4
OA Rounds
2y 9m
To Grant
93%
With Interview

Examiner Intelligence

Grants 82% — above average
82%
Career Allow Rate
651 granted / 794 resolved
+12.0% vs TC avg
Moderate +11% lift
Without
With
+11.1%
Interview Lift
resolved cases with interview
Typical timeline
2y 9m
Avg Prosecution
30 currently pending
Career history
824
Total Applications
across all art units

Statute-Specific Performance

§101
1.7%
-38.3% vs TC avg
§103
32.8%
-7.2% vs TC avg
§102
31.9%
-8.1% vs TC avg
§112
22.5%
-17.5% vs TC avg
Black line = Tech Center average estimate • Based on career data from 794 resolved cases

Office Action

§DP
DETAILED ACTION The following is a final office action is response to communications received on 01/27/2026. Claims 1-19 are currently pending and addressed below. Notice of Pre-AIA or AIA Status The present application is being examined under the pre-AIA first to invent provisions. Response to Arguments Applicant’s arguments, see pages 5-8, filed 01/27/2026, with respect to claims 1 & 12 have been fully considered and are persuasive. Holloway et al. (US8,262,979) in view of Anneaux et al. (US 7,244,272) fails to teach wherein a non-electrospun layer is disposed between inner and outer layers of electrospun PTFE. The 103 rejection of claims 1 & 12 has been withdrawn. Double Patenting The nonstatutory double patenting rejection is based on a judicially created doctrine grounded in public policy (a policy reflected in the statute) so as to prevent the unjustified or improper timewise extension of the “right to exclude” granted by a patent and to prevent possible harassment by multiple assignees. A nonstatutory double patenting rejection is appropriate where the conflicting claims are not identical, but at least one examined application claim is not patentably distinct from the reference claim(s) because the examined application claim is either anticipated by, or would have been obvious over, the reference claim(s). See, e.g., In re Berg, 140 F.3d 1428, 46 USPQ2d 1226 (Fed. Cir. 1998); In re Goodman, 11 F.3d 1046, 29 USPQ2d 2010 (Fed. Cir. 1993); In re Longi, 759 F.2d 887, 225 USPQ 645 (Fed. Cir. 1985); In re Van Ornum, 686 F.2d 937, 214 USPQ 761 (CCPA 1982); In re Vogel, 422 F.2d 438, 164 USPQ 619 (CCPA 1970); In re Thorington, 418 F.2d 528, 163 USPQ 644 (CCPA 1969). A timely filed terminal disclaimer in compliance with 37 CFR 1.321(c) or 1.321(d) may be used to overcome an actual or provisional rejection based on nonstatutory double patenting provided the reference application or patent either is shown to be commonly owned with the examined application, or claims an invention made as a result of activities undertaken within the scope of a joint research agreement. See MPEP § 717.02 for applications subject to examination under the first inventor to file provisions of the AIA as explained in MPEP § 2159. See MPEP § 2146 et seq. for applications not subject to examination under the first inventor to file provisions of the AIA . A terminal disclaimer must be signed in compliance with 37 CFR 1.321(b). The filing of a terminal disclaimer by itself is not a complete reply to a nonstatutory double patenting (NSDP) rejection. A complete reply requires that the terminal disclaimer be accompanied by a reply requesting reconsideration of the prior Office action. Even where the NSDP rejection is provisional the reply must be complete. See MPEP § 804, subsection I.B.1. For a reply to a non-final Office action, see 37 CFR 1.111(a). For a reply to final Office action, see 37 CFR 1.113(c). A request for reconsideration while not provided for in 37 CFR 1.113(c) may be filed after final for consideration. See MPEP §§ 706.07(e) and 714.13. The USPTO Internet website contains terminal disclaimer forms which may be used. Please visit www.uspto.gov/patent/patents-forms. The actual filing date of the application in which the form is filed determines what form (e.g., PTO/SB/25, PTO/SB/26, PTO/AIA /25, or PTO/AIA /26) should be used. A web-based eTerminal Disclaimer may be filled out completely online using web-screens. An eTerminal Disclaimer that meets all requirements is auto-processed and approved immediately upon submission. For more information about eTerminal Disclaimers, refer to www.uspto.gov/patents/apply/applying-online/eterminal-disclaimer. Claims 1-8, 12 & 14-19 are rejected on the ground of nonstatutory double patenting as being unpatentable over claims 1, 3, 8, 9, 13 & 15 of U.S. Patent No. 9,655,710. Although the claims at issue are not identical, they are not patentably distinct from each other because the Patent and the instant application all recite the same basic structure with a permutation of similar elements throughout. Regarding Claim 1, patent claims 1, 3, 13 & 15 also recite a stent, comprising; a coating, the coating comprising: an inner layer of electrospun polytetrafluoroethylene (PTFE) fibers; an outer layer of electrospun PTFE fibers, and a non-electrospun tie layer disposed between the inner layer of electrospun PTFE fibers and the outer layer of electrospun PTFE fibers, wherein the inner layer of electrospun PTFE fibers has an average pore size configured to permit growth of endothelial cells on a surface of the stent and the non-electrospun tie layer is impermeable to tissue growth. Regarding Claim 12, patent claims 1, 3, 13 & 15 also recite a method of constructing a stent, comprising; electrospinning a first tube of PTFE onto a rotating mandrel; sintering the first tube; applying a tie layer around the first tube, and applying a second tube of electrospun PTFE around the tie layer, wherein the first tube of PTFE has an average pore size configured to permit growth of endothelial cells on a surface of the stent and the tie layer is impermeable to tissue growth. Regarding Claims 2-8, patent claims 1, 8 & 9 recite the same limitations. Regarding Claims 14-19, patent claims 1, 6-8 & 13 recite the same limitations. Claims 1, 3, 6, 7 & 12 are rejected on the ground of nonstatutory double patenting as being unpatentable over claims 1,3, 11 & 15 of U.S. Patent No. 10,507,268. Although the claims at issue are not identical, they are not patentably distinct from each other because the Patent and the instant application all recite the same basic structure with a permutation of similar elements throughout. Regarding Claim 1, patent claims 1, 2, 11 & 15 also recite a stent, comprising; a coating, the coating comprising: an inner layer of electrospun polytetrafluoroethylene (PTFE) fibers; an outer layer of electrospun PTFE fibers, and a non-electrospun tie layer disposed between the inner layer of electrospun PTFE fibers and the outer layer of electrospun PTFE fibers, wherein the inner layer of electrospun PTFE fibers has an average pore size configured to permit growth of endothelial cells on a surface of the stent and the non-electrospun tie layer is impermeable to tissue growth. Regarding Claim 12, patent claims 1, 11 & 15 also recite a method of constructing a stent, comprising; electrospinning a first tube of PTFE onto a rotating mandrel; sintering the first tube; applying a tie layer around the first tube, and applying a second tube of electrospun PTFE around the tie layer, wherein the first tube of PTFE has an average pore size configured to permit growth of endothelial cells on a surface of the stent and the tie layer is impermeable to tissue growth. Regarding Claim 3, patent claim 3 recites the same limitations. Regarding Claim 6, patent claim 1 recites the same limitations. Regarding Claim 7, patent claim 11 recites the same limitations. Claims 1-13 & 15-19 are rejected on the ground of nonstatutory double patenting as being unpatentable over claims 1, 5, 7-9, 14-16, 18 & 19 of U.S. Patent No. 10,653,511. Although the claims at issue are not identical, they are not patentably distinct from each other because the Patent and the instant application all recite the same basic structure with a permutation of similar elements throughout. Regarding Claim 1, patent claim 1 also recites a stent, comprising; a coating, the coating comprising: an inner layer of electrospun polytetrafluoroethylene (PTFE) fibers; an outer layer of electrospun PTFE fibers, and a non-electrospun tie layer disposed between the inner layer of electrospun PTFE fibers and the outer layer of electrospun PTFE fibers, wherein the inner layer of electrospun PTFE fibers has an average pore size configured to permit growth of endothelial cells on a surface of the stent and the non-electrospun tie layer is impermeable to tissue growth. Regarding Claim 12, patent claim 1 also recites a method of constructing a stent, comprising; electrospinning a first tube of PTFE onto a rotating mandrel; sintering the first tube; applying a tie layer around the first tube, and applying a second tube of electrospun PTFE around the tie layer, wherein the first tube of PTFE has an average pore size configured to permit growth of endothelial cells on a surface of the stent and the tie layer is impermeable to tissue growth. Regarding Claims 3, 4,15 & 16, patent claim 5 recites the same limitations. Regarding Claims 5 & 6, patent claim 1 recites the same limitations. Regarding Claims 7 & 8, patent claim 7 recites the same limitations. Regarding Claims 9 & 10, patent claims 8 & 9 recite the same limitations. Regarding Claims 17 & 18, patent claims 18 & 19 recite the same limitations. Claims 1, 8 & 11 are rejected on the ground of nonstatutory double patenting as being unpatentable over claims 1 & 6 of U.S. Patent No. 10,653,512. Although the claims at issue are not identical, they are not patentably distinct from each other because the Patent and the instant application all recite the same basic structure with a permutation of similar elements throughout. Regarding Claim 1, patent claim 1 also recites a stent, comprising; a coating, the coating comprising: an inner layer of electrospun polytetrafluoroethylene (PTFE) fibers; an outer layer of electrospun PTFE fibers, and a non-electrospun tie layer disposed between the inner layer of electrospun PTFE fibers and the outer layer of electrospun PTFE fibers, wherein the inner layer of electrospun PTFE fibers has an average pore size configured to permit growth of endothelial cells on a surface of the stent and the non-electrospun tie layer is impermeable to tissue growth. Regarding Claim 8, patent claim 1 recites the same limitations. Regarding Claim 11, patent claim 6 recites the same limitations. Claims 1 & 12 are rejected on the ground of nonstatutory double patenting as being unpatentable over claims 1, 3, 5 & 18 of U.S. Patent No. 11,541,154. Although the claims at issue are not identical, they are not patentably distinct from each other because the Patent and the instant application all recite the same basic structure with a permutation of similar elements throughout. Regarding Claim 1, patent claims 1, 3, 5 & 18 also recite a stent, comprising; a coating, the coating comprising: an inner layer of electrospun polytetrafluoroethylene (PTFE) fibers; an outer layer of electrospun PTFE fibers, and a non-electrospun tie layer disposed between the inner layer of electrospun PTFE fibers and the outer layer of electrospun PTFE fibers, wherein the inner layer of electrospun PTFE fibers has an average pore size configured to permit growth of endothelial cells on a surface of the stent and the non-electrospun tie layer is impermeable to tissue growth. Regarding Claim 12, patent claim 1, 3, 5 & 18 also recite a method of constructing a stent, comprising; electrospinning a first tube of PTFE onto a rotating mandrel; sintering the first tube; applying a tie layer around the first tube, and applying a second tube of electrospun PTFE around the tie layer, wherein the first tube of PTFE has an average pore size configured to permit growth of endothelial cells on a surface of the stent and the tie layer is impermeable to tissue growth. Conclusion Applicant's amendment necessitated the new ground(s) of rejection presented in this Office action. Accordingly, THIS ACTION IS MADE FINAL. See MPEP § 706.07(a). Applicant is reminded of the extension of time policy as set forth in 37 CFR 1.136(a). A shortened statutory period for reply to this final action is set to expire THREE MONTHS from the mailing date of this action. In the event a first reply is filed within TWO MONTHS of the mailing date of this final action and the advisory action is not mailed until after the end of the THREE-MONTH shortened statutory period, then the shortened statutory period will expire on the date the advisory action is mailed, and any nonprovisional extension fee (37 CFR 1.17(a)) pursuant to 37 CFR 1.136(a) will be calculated from the mailing date of the advisory action. In no event, however, will the statutory period for reply expire later than SIX MONTHS from the mailing date of this final action. Any inquiry concerning this communication or earlier communications from the examiner should be directed to BRIAN AINSLEY DUKERT whose telephone number is (571)270-3258. The examiner can normally be reached Mon-Fri 6am-4pm. Examiner interviews are available via telephone, in-person, and video conferencing using a USPTO supplied web-based collaboration tool. To schedule an interview, applicant is encouraged to use the USPTO Automated Interview Request (AIR) at http://www.uspto.gov/interviewpractice. If attempts to reach the examiner by telephone are unsuccessful, the examiner’s supervisor, Melanie Tyson can be reached at (571)272-9062. The fax phone number for the organization where this application or proceeding is assigned is 571-273-8300. Information regarding the status of published or unpublished applications may be obtained from Patent Center. Unpublished application information in Patent Center is available to registered users. To file and manage patent submissions in Patent Center, visit: https://patentcenter.uspto.gov. Visit https://www.uspto.gov/patents/apply/patent-center for more information about Patent Center and https://www.uspto.gov/patents/docx for information about filing in DOCX format. For additional questions, contact the Electronic Business Center (EBC) at 866-217-9197 (toll-free). If you would like assistance from a USPTO Customer Service Representative, call 800-786-9199 (IN USA OR CANADA) or 571-272-1000. /BRIAN A DUKERT/Primary Examiner, Art Unit 3774
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Prosecution Timeline

Jan 09, 2023
Application Filed
Aug 23, 2025
Non-Final Rejection — §DP
Jan 27, 2026
Response Filed
Mar 21, 2026
Final Rejection — §DP (current)

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Prosecution Projections

3-4
Expected OA Rounds
82%
Grant Probability
93%
With Interview (+11.1%)
2y 9m
Median Time to Grant
Moderate
PTA Risk
Based on 794 resolved cases by this examiner. Grant probability derived from career allow rate.

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