Prosecution Insights
Last updated: April 19, 2026
Application No. 18/183,827

STENT GRAFT WITH ELASTOMERIC IMPERMEABLE LAYER

Non-Final OA §103§112
Filed
Mar 14, 2023
Examiner
PRESTON, REBECCA STRASZHEIM
Art Unit
3774
Tech Center
3700 — Mechanical Engineering & Manufacturing
Assignee
Merit Medical Systems Inc.
OA Round
1 (Non-Final)
74%
Grant Probability
Favorable
1-2
OA Rounds
3y 7m
To Grant
99%
With Interview

Examiner Intelligence

Grants 74% — above average
74%
Career Allow Rate
453 granted / 616 resolved
+3.5% vs TC avg
Strong +37% interview lift
Without
With
+37.1%
Interview Lift
resolved cases with interview
Typical timeline
3y 7m
Avg Prosecution
28 currently pending
Career history
644
Total Applications
across all art units

Statute-Specific Performance

§101
1.1%
-38.9% vs TC avg
§103
28.7%
-11.3% vs TC avg
§102
33.1%
-6.9% vs TC avg
§112
32.4%
-7.6% vs TC avg
Black line = Tech Center average estimate • Based on career data from 616 resolved cases

Office Action

§103 §112
DETAILED ACTION Notice of Pre-AIA or AIA Status The present application, filed on or after March 16, 2013, is being examined under the first inventor to file provisions of the AIA . Election/Restrictions Applicant’s election without traverse of Group I in the reply filed on 2/13/2026 is acknowledged. Claim(s) 13-17 is/are withdrawn from further consideration pursuant to 37 CFR 1.142(b) as being drawn to a nonelected invention, there being no allowable generic or linking claim. Election was made without traverse in the reply filed on 2/13/2026. Claim Objections Claim(s) 1, 4, 18, 20 is/are objected to because of the following informalities: Within claim 1, line 3 (and claim 18, line 3): “a vascular prosthesis” should be replaced with --the vascular prosthesis-- (to properly link to the vascular prosthesis within claim 1, line 1 of claim 18, line 1). Within claim 4, line 3 (and claim 20, lien 3): “the multilayered vascular prosthesis” should be replaced with --the vascular prosthesis-- (in order to maintain consistent claim terminology). Appropriate correction is required. Claim Rejections - 35 USC § 112 The following is a quotation of 35 U.S.C. 112(b): (b) CONCLUSION.—The specification shall conclude with one or more claims particularly pointing out and distinctly claiming the subject matter which the inventor or a joint inventor regards as the invention. The following is a quotation of 35 U.S.C. 112 (pre-AIA ), second paragraph: The specification shall conclude with one or more claims particularly pointing out and distinctly claiming the subject matter which the applicant regards as his invention. Claim(s) 4, 6-7, 18-20 is/are rejected under 35 U.S.C. 112(b) or 35 U.S.C. 112 (pre-AIA ), second paragraph, as being indefinite for failing to particularly point out and distinctly claim the subject matter which the inventor or a joint inventor (or for applications subject to pre-AIA 35 U.S.C. 112, the applicant), regards as the invention. Claim 4 recites the limitation "the axis of expansion" in lines 1-2. There is insufficient antecedent basis for this limitation in the claim. Within claim 6, lines 1-2: Applicant claims, “wherein the second layer circumferentially stretches when the vascular prosthesis is expanded”; it is unclear, and therefore indefinite, what Applicant considers to be the scope of the invention – the scope of the claim is determined by the preamble (which is to the vascular prosthesis alone); however, the aforementioned claim requirement is claiming the method of use (as to how second layer stretches/ expanded). As such, if it unclear, whether Applicant is trying to claim the vascular prosthesis or the method us implanting/ using the vascular prosthesis. (Please note: if Applicant is trying to claim the vascular prosthesis – Applicant could amend the aforementioned claim requirement to --wherein the second layer is configured to circumferentially stretch when the vascular prosthesis is expanded--.) Within claim 7, lines 1-3: Applicant claims, “wherein each of the first and third layer circumferentially stretch when the vascular prosthesis is expanded”; it is unclear, and therefore indefinite, what Applicant considers to be the scope of the invention – the scope of the claim is determined by the preamble (which is to the vascular prosthesis alone); however, the aforementioned claim requirement is claiming the method of use (as to how layers stretches/ expanded). As such, if it unclear, whether Applicant is trying to claim the vascular prosthesis or the method us implanting/ using the vascular prosthesis. (Please note: if Applicant is trying to claim the vascular prosthesis – Applicant could amend the aforementioned claim requirement to --wherein each of the first and third layer is configured to circumferentially stretch when the vascular prosthesis is expanded--.) Within claim 18, line 5: Applicant claims, “a third layer comprising polytetrafluoroethylene (ePTFE)”; it is unclear, and therefore indefinite, if the third layer comprises: polytetrafluoroethylene (PTFE) OR expanded polytetrafluoroethylene (ePTFE)? Claim(s) 19-20, inherit all the problems associated with claim 18. Within claim 20, line 2: Applicant claims, “an ePTFE layer”; it is unclear, and therefore indefinite, if this is the same as OR different from the ePTFE (?) third layer (within claim 18, line 5)? Claim Rejections - 35 USC § 103 In the event the determination of the status of the application as subject to AIA 35 U.S.C. 102 and 103 (or as subject to pre-AIA 35 U.S.C. 102 and 103) is incorrect, any correction of the statutory basis (i.e., changing from AIA to pre-AIA ) for the rejection will not be considered a new ground of rejection if the prior art relied upon, and the rationale supporting the rejection, would be the same under either status. The following is a quotation of 35 U.S.C. 103 which forms the basis for all obviousness rejections set forth in this Office action: A patent for a claimed invention may not be obtained, notwithstanding that the claimed invention is not identically disclosed as set forth in section 102, if the differences between the claimed invention and the prior art are such that the claimed invention as a whole would have been obvious before the effective filing date of the claimed invention to a person having ordinary skill in the art to which the claimed invention pertains. Patentability shall not be negated by the manner in which the invention was made. Claim(s) 1-2, 4-12, 18-20 is/are rejected under 35 U.S.C. 103 as being unpatentable over Hall et al. (US 2016/0250048 A1) in view of Cully et al. (US 2007/0250153 A1) (as evidenced by Akhtar et al. (US 2005/0187607 A1) for claim 12). With respect to claim 1. Hall et al. discloses the invention substantially as claimed. Specifically, Hall et al. discloses a multilayered vascular prosthesis (medical applicant 100), as can be seen in figs. 3A-3C, comprising: a first layer (first layer 110) comprising serially deposited polytetrafluoroethylene (PTFE) fibers (rotational spun PTFE) providing a luminal surface (luminal surface) of a vascular prosthesis (medical applicant 100) (paragraph [0049]); a second layer (fourth layer 140) comprising an elastomeric material (FEP is considered an elastomeric material as they have “sufficient elasticity” to allow for expansion (Applicant’s specifications [0064])) (paragraphs [0059-0061]); a third layer (fifth layer 150) comprising expanded polytetrafluoroethylene (ePTFE) (ePTFE) providing an abluminal surface (abluminal surface) of the vascular prosthesis (medical applicant 100) (paragraphs [0059, 0062]), wherein the second layer (fourth layer 140) is disposed between the first layer (first layer 110) and the third layer (fifth layer 150) (paragraph [0059]); and a scaffolding (scaffolding structure 130) disposed between the first layer (first layer 110) and the second layer (fourth layer 140) (paragraph [0059]); However, Hall et al. is silent regarding: the vascular prosthesis (medical applicant 100) having a nominal state (with a nominal diameter) and an expanded state (with an expanded diameter); wherein the second layer is non-stretched in the nominal state; wherein the expanded diameter is larger than the nominal diameter; and wherein the vascular prosthesis (medical applicant 100) is free of pleats when the vascular prosthesis (medical applicant 100) is in the nominal state and the expanded state (as required by claim 1). Cully et al. teaches a vascular prosthesis (implantable device 60), as can be seen in figs. 1a-2c, comprising: a graft layer (cover 62) and a self-expanding scaffolding (stent component 63) (paragraph [0046]). The vascular prosthesis (implantable device 60) is manufactured by attaching the graft layer (cover 62) to the self-expanding scaffolding (stent component 63) while the self-expanding scaffolding (stent component 63) is in a nominal diameter (at which the cover 62 is applied to the stent component 63, as can be seen in fig. 2b) which is smaller (90% is less) than an expanded diameter (fully deployed, as can be seen in fig. 2c) (paragraphs [abstract, 0049, 0055-0059, 0062]). This method of attaching/ manufacturing the vascular prosthesis (implantable device 60) both prevents the vascular prosthesis (implantable device 60) from having pleats in both the nominal state (at which the cover 62 is applied to the stent component 63, as can be seen in fig. 2b) and the expanded state (fully deployed, as can be seen in fig. 2c) (pleats can disrupt blood flow and become sites for clot deposition) (paragraphs [0046]) and reduces the perforation risks for the graft layer (cover 62) during crushing (paragraph [0062]). When the vascular prosthesis (implantable device 60) in in the in the nominal state (at which the cover 62 is applied to the stent component 63, as can be seen in fig. 2b) the graft layer (cover 62) will be non-stretched (as there is no radial stretching as the graft is radially constrained within a constraining tube) (paragraph [0058]). It would have been obvious to one having ordinary skill in the art at the time the invention was made to attach the first layer (first layer 110), second layer (fourth layer 140), and third layer (fifth layer 150) to the scaffolding (scaffolding structure 130), as disclosed by Hall et al., while the scaffolding (scaffolding structure 130) is in a nominal state (partially expanded/ diameter smaller (90% or less) than the fully expanded state), as taught by Cully et al., thereby preventing the vascular prosthesis (medical applicant 100) from having pleats in both the nominal state (partially expanded/ diameter smaller than the fully expanded state) and the fully expanded state and requiring less crushing (and thereby reducing the risks of perforations) during the collapse of the vascular prosthesis (medical applicant 100) for delivery, as taught by Cully et al. With respect to claim 2: Wherein the second layer (fourth layer 140) is cell impermeable (impermeable regardless of state) when the vascular prosthesis (medical applicant 100) (Cully et al. paragraph [0060]), as disclosed by Hall et al. as modified by Cully et al., is in the nominal state (partially expanded/ diameter smaller than the fully expanded state) and the expanded state (fully expanded state). With respect to claim 4: Wherein the axis of expansion (axis of expansion) of one or more sublayers (any single layer) of the third layer (fifth layer 150) of ePTFE (ePTFE), as disclosed by Hall et al., is disposed at an angle of between 0° and 25° to a longitudinal axis (aligned with a central axis of the prosthesis) of the vascular prosthesis (medical applicant 100) (Hall et al. paragraph [0073]). With respect to claim 5: Hall et al. discloses the invention substantially as claimed, as discussed above. However, Hall et al. is silent with respect to the dimensions of the vascular prosthesis (medical applicant 100) (specifically, the nominal diameter ranging from 2-55 mm and the expanded diameter ranging from 4-55 mm (as required by claim 5)). Cully et al. additionally teaches the vascular prosthesis (implantable device 60) to have an expanded diameter (fully deployed, as can be seen in fig. 2c) of 8 mm (paragraph [0089]) and a nominal diameter (at which the cover 62 is applied to the stent component 63, as can be seen in fig. 2b) of 4 mm (paragraphs [0081, 0084]). It would further have been obvious to one having ordinary skill in the art at the time the invention was made to further modify the vascular prosthesis (medical applicant 100), as disclosed by Hall et al., to have the same/ similar dimensions (both during the manufacturing and for the final product), as taught by Cully et al., as both structures are used for the same/ similar purposes (as grafts within a patients vascular) (thus resulting in the vascular prosthesis (implantable device 60), as disclosed by Hall et al. as modified by Cully et al., having a nominal diameter (at which the cover 62 is applied to the stent component 63, as can be seen in fig. 2b) of 4 mm and an expanded diameter (fully deployed, as can be seen in fig. 2c) of 8 mm). With respect to claim 6: Wherein the second layer (fourth layer 140) is configured to circumferentially stretch when the vascular prosthesis (medical applicant 100), as disclosed by Hall et al. as modified by Cully et al., is expanded from the nominal state (partially expanded/ diameter smaller than (90% or less) the fully expanded state) to the expanded state (fully expanded state), and wherein the circumferential stretch ranges from 0% to 200%, as taught by Cully et al. (Cully et al. paragraph [0049] – the nominal state (partially expanded/ diameter smaller than the fully expanded state) is 90% or less the size of the expanded state (fully expanded state); as such, when the vascular prosthesis (medical applicant 100), as disclosed by Hall et al. as modified by Cully et al., as w whole expands from the nominal state (partially expanded/ diameter smaller than the fully expanded state) to the expanded state (fully expanded state) circumferential stretch will be at least 100% but less than 200% (for cases wen the nominal state (partially expanded/ diameter smaller than the fully expanded state) is 50% the expanded state (fully expanded state)). With respect to claim 7: Wherein each of the first layer (first layer 110) and the third layer (fifth layer 150) circumferentially stretch when the vascular prosthesis (medical applicant 100), as disclosed by Hall et al. as modified by Cully et al., is expanded from the nominal state (partially expanded/ diameter smaller than (90% or less) the fully expanded state) to the expanded state (fully expanded state), and wherein the circumferential stretch ranges from 0% to 200%, as taught by Cully et al. (Cully et al. paragraph [0049] – the nominal state (partially expanded/ diameter smaller than the fully expanded state) is 90% or less the size of the expanded state (fully expanded state); as such, when the vascular prosthesis (medical applicant 100), as disclosed by Hall et al. as modified by Cully et al., as w whole expands from the nominal state (partially expanded/ diameter smaller than the fully expanded state) to the expanded state (fully expanded state) circumferential stretch will be at least 100% but less than 200% (for cases when the nominal state (partially expanded/ diameter smaller than the fully expanded state) is 50% the expanded state (fully expanded state)). With respect to claim 8: Wherein the scaffolding (scaffolding structure 130), as disclosed by Hall et al. as modified by Cully et al., is configured to resist a radially inward oriented force applied by the second layer (fourth layer 140) to prevent the vascular prosthesis (medical applicant 100) from contracting from the expanded state (fully expanded state) to the nominal state (partially expanded/ diameter smaller than the fully expanded state) (Cully et al. paragraph [0062] – the stent component stretched the graft component, as such the stent must resist the radial inward force of the graft component due to the graft component stretching). With respect to claim 9. Wherein the scaffolding (scaffolding structure 130), as disclosed by Hall et al. as modified by Cully et al., is configured to apply a radially outward oriented force (stretching) to circumferentially stretch the second layer (fourth layer 140) 100% (to the fully expanded state which is considered 100%) (Cully et al. paragraph [0062] – the stent component stretched the graft component, as such the stent must resist the radial inward force of the graft component due to the graft component stretching). With respect to claim 10: Wherein the serially deposited PTFE fibers (PTFE fibers of the first layer 110), as disclosed by Hall et al., are rotational spun (rotationally spun) (Hall et al. paragraph [0049]). With respect to claim 11: Wherein the vascular prosthesis (medical applicant 100) is a self-expanding stent graft (the scaffold structure 130 which is responsible for the expansion of the vascular prosthesis (medical applicant 100) is made from nitinol, a self-expanding material) (Hall et al. paragraph [0059]). With respect to claim 12: Wherein the vascular prosthesis (medical applicant 100) is a balloon expandable stent graft (the scaffold structure 130 which is responsible for the expansion of the vascular prosthesis (medical applicant 100) is made from stainless steel, a balloon material) (Hall et al. paragraph [0059]) (stainless steel is a balloon expandable material as evidenced by Akhtar et al. paragraph [0025]). With respect to claim 18: Hall et al. discloses the invention substantially as claimed. Specifically, Hall et al. discloses a multilayered vascular prosthesis (medical applicant 100), as can be seen in figs. 3A-3C, comprising: a first layer (first layer 110) comprising polytetrafluoroethylene (PTFE) providing a luminal surface (luminal surface) of a vascular prosthesis (medical applicant 100) (paragraph [0049]); a second layer (fourth layer 140) comprising an elastomeric material (FEP is considered an elastomeric material as they have “sufficient elasticity” to allow for expansion (Applicant’s specifications [0064])) (paragraphs [0059-0061]); a third layer (fifth layer 150) comprising expanded polytetrafluoroethylene (ePTFE) (ePTFE) providing an abluminal surface (abluminal surface) of the vascular prosthesis (medical applicant 100) (paragraphs [0059, 0062]), wherein the second layer (fourth layer 140) is disposed between the first layer (first layer 110) and the third layer (fifth layer 150) (paragraph [0059]); and a scaffolding (scaffolding structure 130) disposed between the first layer (first layer 110) and the second layer (fourth layer 140) (paragraph [0059]); However, Hall et al. is silent regarding: the vascular prosthesis (medical applicant 100) having a nominal state (with a nominal diameter) and an expanded state (with an expanded diameter); wherein the second layer is non-stretched in the nominal state; wherein the expanded diameter is larger than the nominal diameter; and wherein the vascular prosthesis (medical applicant 100) is free of pleats when the vascular prosthesis (medical applicant 100) is in the nominal state and the expanded state (as required by claim 18). Cully et al. teaches a vascular prosthesis (implantable device 60), as can be seen in figs. 1a-2c, comprising: a graft layer (cover 62) and a self-expanding scaffolding (stent component 63) (paragraph [0046]). The vascular prosthesis (implantable device 60) is manufactured by attaching the graft layer (cover 62) to the self-expanding scaffolding (stent component 63) while the self-expanding scaffolding (stent component 63) is in a nominal diameter (at which the cover 62 is applied to the stent component 63, as can be seen in fig. 2b) which is smaller than an expanded diameter (fully deployed, as can be seen in fig. 2c) (paragraphs [abstract, 0055-0059, 0062]). This method of attaching/ manufacturing the vascular prosthesis (implantable device 60) both prevents the vascular prosthesis (implantable device 60) from having pleats in both the nominal state (at which the cover 62 is applied to the stent component 63, as can be seen in fig. 2b) and the expanded state (fully deployed, as can be seen in fig. 2c) (pleats can disrupt blood flow and become sites for clot deposition) (paragraphs [0046]) and reduces the perforation risks for the graft layer (cover 62) during crushing (paragraph [0062]). When the vascular prosthesis (implantable device 60) in in the in the nominal state (at which the cover 62 is applied to the stent component 63, as can be seen in fig. 2b) the graft layer (cover 62) will be non-stretched (as there is no radial stretching as the graft is radially constrained within a constraining tube) (paragraph [0058]). It would have been obvious to one having ordinary skill in the art at the time the invention was made to attach the first layer (first layer 110), second layer (fourth layer 140), and third layer (fifth layer 150) to the scaffolding (scaffolding structure 130), as disclosed by Hall et al., while the scaffolding (scaffolding structure 130) is in a nominal state (partially expanded/ diameter smaller than the fully expanded state), as taught by Cully et al., thereby preventing the vascular prosthesis (medical applicant 100) from having pleats in both the nominal state (partially expanded/ diameter smaller than the fully expanded state) and the fully expanded state and requiring less crushing (and thereby reducing the risks of perforations) during the collapse of the vascular prosthesis (medical applicant 100) for delivery, as taught by Cully et al. With respect to claim 19: Wherein the second layer (fourth layer 140) is cell impermeable (impermeable regardless of state) when the vascular prosthesis (medical applicant 100) (Cully et al. paragraph [0060]), as disclosed by Hall et al. as modified by Cully et al., is in the nominal state (partially expanded/ diameter smaller than the fully expanded state) and the expanded state (fully expanded state). With respect to claim 20: Wherein an axis of expansion (axis of expansion) of one or more sublayers (any single layer) of the third layer (fifth layer 150) of ePTFE (ePTFE), as disclosed by Hall et al., is disposed at an angle of between 0° and 25° to a longitudinal axis (aligned with a central axis of the prosthesis) of the vascular prosthesis (medical applicant 100) (Hall et al. paragraph [0073]). Claim(s) 3 is/are rejected under 35 U.S.C. 103 as being unpatentable over Hall et al. (US 2016/0250048 A1) as modified by Cully et al. (US 2007/0250153 A1) as applied to claim(s) 1-2, 4, 6-11, 18-20 above, and further in view of Ballard et al. (US 2013/0238086 A1). With respect to claim 3: Hall et al. as modified by Cully et al. discloses the invention substantially as claimed, as discussed above. However, Hall et al. as modified by Cully et al. does not disclose the elastomeric material (FEP) of the second layer (fourth layer 140) to comprise silicone or polyurethane. Ballard et al. teaches a multilayered vascular prosthesis, as can be seen in figs. 2A-2B, comprising: a luminal first layer (inner layer 220) (paragraph [0045]); an impermeable second layer (tie layer) (paragraph [0046]); an abluminal third layer (outer layer 210) (paragraph [045]); and a scaffolding (wire 110). The impermeable second layer (tie layer) maybe made from FEP, silicone, polyurethane (paragraphs [0047]). It would have been obvious to one having ordinary skill in the art at the time the invention was made to replace the FEP of the second layer (fourth layer 140), as disclosed by Hall et al. as modified by Cully et al., with either silicone or polyurethane, as taught by Ballard et al., as Ballard et al. teaches the materials to be interchangeable in creating an impermeable bonding layer between two other graft layers. Conclusion Any inquiry concerning this communication or earlier communications from the examiner should be directed to REBECCA S PRESTON whose telephone number is (571)270-5233. The examiner can normally be reached M, W: 9-5; T, Th, F: 9-1. 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, Jerrah Edwards can be reached at (408)918-7557. 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. /REBECCA S PRESTON/ Primary Examiner, Art Unit 3774
Read full office action

Prosecution Timeline

Mar 14, 2023
Application Filed
Mar 05, 2026
Non-Final Rejection — §103, §112 (current)

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Study what changed to get past this examiner. Based on 5 most recent grants.

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Prosecution Projections

1-2
Expected OA Rounds
74%
Grant Probability
99%
With Interview (+37.1%)
3y 7m
Median Time to Grant
Low
PTA Risk
Based on 616 resolved cases by this examiner. Grant probability derived from career allow rate.

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