Ex Parte Ferrera et al

Patent Trial and Appeal Board

Jun 21, 2018

13172778 (P.T.A.B. Jun. 21, 2018)

UNITED STA TES p A TENT AND TRADEMARK OFFICE
APPLICATION NO. FILING DATE
13/172,778 06/29/2011
137574 7590 06/25/2018
Medtronic
826 Coal Creek Circle
Louisville, CO 80027
FIRST NAMED INVENTOR
David A. Ferrera
UNITED STATES DEPARTMENT OF COMMERCE
United States Patent and Trademark Office
Address: COMMISSIONER FOR PATENTS
P.O. Box 1450
Alexandria, Virginia 22313-1450
www .uspto.gov
ATTORNEY DOCKET NO. CONFIRMATION NO.
H-KN-02746US9 7982
EXAMINER
BACHMAN, LINDSEY MICHELE
ART UNIT PAPER NUMBER
3731
NOTIFICATION DATE DELIVERY MODE
06/25/2018 ELECTRONIC
Please find below and/or attached an Office communication concerning this application or proceeding.
The time period for reply, if any, is set in the attached communication.
Notice of the Office communication was sent electronically on above-indicated "Notification Date" to the
following e-mail address( es):
rs. patents. two@medtronic.com
docketing@fortemip.com
PTOL-90A (Rev. 04/07)
UNITED STATES PATENT AND TRADEMARK OFFICE
BEFORE THE PATENT TRIAL AND APPEAL BOARD
Ex parte DAVID A. FERRERA, ANDREW H. CRAGG,
and JOHN FULKERSON 1
Appeal 2016-008577
Application 13/172,778
Technology Center 3700
Before TONI R. SCHEINER, ULRIKE W. JENKS,
and CHRISTOPHER G. PAULRAJ, Administrative Patent Judges.
SCHEINER, Administrative Patent Judge.
DECISION ON APPEAL
This is an appeal under 35 U.S.C. § 134 from the final rejection of
claims 1-10, 12, and 14--20, directed to a method of managing a thrombus in
neurovasculature. The claims have been rejected as obvious. We have
jurisdiction under 35 U.S.C. § 6(b ).
We reverse.
1 Appellants identify the Real Party in Interest as Covidien LP. Appeal
Br. 2.
Appeal 2016-008577
Application 13/172,778
BACKGROUND
An ischemic stroke occurs when a blood vessel in the brain becomes
blocked by an occlusion. Occlusion may be partial or complete, and may be
due to a thrombus (i.e., a blood clot), among other obstructions. Spec. i-f 13.
The Specification discloses a "thrombus management method" (id. i-f 15)
"for the treatment of acute ischemic stroke that provide[ s] immediate blood
flow restoration to a vessel occluded by a clot and, after reestablishing blood
flow, address[ es] the clot itself' (id. i-f 14).
The thrombus management method comprises identifying a blood
vessel (e.g., a neurovascular artery) having a thrombus, and inserting an
expandable tip assembly comprising a scaffold through a microcatheter into
the thrombus. The scaffold is a self-expandable, cylindrical body comprised
of a plurality of struts and bridges forming a plurality of cells sized and
shaped to impact, compress, and engage thrombus material upon radial
expansion of the self-expandable scaffold. Id. i-fi-115, 16. Expansion of the
scaffold impacts and compresses the thrombus against a wall of the blood
vessel, restoring blood flow within the blood vessel. Id. i-f 17.
In addition, the thrombus management method comprises macerating
the thrombus by repeatedly resheathing the scaffold and unsheathing the
scaffold (i.e., advancing and retracting the microcatheter), thereby
facilitating mechanical lysis and fragmentation of the thrombus to release
embolic particles. Id. The embolic particles flow in the direction of blood
flow and can be lysed through a natural lysis process due to the restored
blood flow, without the need for a distal embolic protection member to
capture the embolic particles. Id.
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Application 13/172,778
STATEMENT OF THE CASE
Claims 1-10, 12, and 14--20 are on appeal. Claims 11 and 13 have
been canceled. Claims 1, 10, and 18 are independent, Claim 1 is
representative of the subject matter on appeal, and reads as follows (with the
principal disputed limitation italicized):
1. A method of managing a thrombus in neurovasculature
without distal embolic protection for the treatment of acute
ischemic stroke, the method comprising:
identifying an occluded artery of the neurovasculature of
a subject having a thrombus;
inserting a balloon guide catheter within the subject and
advancing a distal end of the balloon guide catheter to an
arterial location proximal to the occluded artery;
inserting a guidewire through the balloon guide catheter
and advancing a distal end of the guidewire within the occluded
artery and through or to the side of the thrombus,
inserting a distal access catheter through the guide
catheter and advancing a distal end of the distal access catheter
to a location within the occluded artery proximate the
thrombus;
inserting a microcatheter through the distal access
catheter and advancing a distal end of the microcatheter through
or to the side of the thrombus;
positioning the distal end of the microcatheter 0.5 to 10
mm past a distal end of the thrombus;
inserting an expandable tip assembly comprising a self-
expandable scaffold tethered to a distal end of an elongate
delivery member through the microcatheter,
wherein said self-expandable scaffold has an open
downstream end and comprises a generally cylindrical body
comprised of a plurality of struts and bridges forming a
plurality of cells,
wherein the cells are sized and shaped to impact,
compress and engage thrombus material upon radial expansion
of the self-expandable scaffold;
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Application 13/172,778
retracting the microcatheter proximally, thereby causing
the self-expandable scaffold to span at least a segment of the
length of the thrombus;
wherein said expansion impacts and compresses the
thrombus against a wall of the occluded artery,
wherein said compression of the thrombus restores blood
flow within the occluded artery,
wherein said restored blood flow facilitates natural lysis
of the thrombus;
while the expandable tip remains stationary, macerating
the thrombus by resheathing the self-expandable scaffold and
unsheathing the self-expandable scaffold, thereby facilitating
mechanical lysis and fragmentation of the thrombus to release
embolic particles,
wherein the embolic particles flow in the direction of the
blood flow and are not captured by any distal embolic
protection member, but are instead lysed through the natural
lysis process due to the restored blood flow; and
removing said expandable tip assembly from the subject,
thereby removing any portions of the thrombus engaged by the
self-expandable scaffold from the occluded artery.
The claims stand rejected under pre-AIA 35 U.S.C. § 103(a) as
follows:
Claims 1-5 and 7-9 as unpatentable over Rapaport, 2 Miller, 3
Slee,4 and Radisch5 (Final Act. 3-8); 6
2 Avraham Rapaport & Gilad Cibulski, WO 2010/146581 Al, published
December 23, 2010 ("Rapaport").
3 John Miller & Scott Wilson, U.S. Patent Application Publication No.
2008/0188865 Al, published August 7, 2008 ("Miller").
4 Earl Howard Slee et al., U.S. Patent Application Publication No.
2011/0060212 Al, published March 10, 2011 ("Slee").
5 Herbert R. Radisch Jr., U.S. Patent Application Publication No.
2004/0127920 Al, published July 1, 2004 ("Radisch").
6 Final Office Action, mailed October 16, 2015.
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Application 13/172,778
Claim 6 as unpatentable over Rapaport, Miller, Slee, Radisch,
and Fiorella 7 (Final Act. 8);
Claims 10, 12, 14--16, 18, and 19 as unpatentable over
Rapaport, Slee, and Radisch (Final Act. 8-15);
Claim 17 as unpatentable over Rapaport, Slee, Radisch, and Fiorella
(Final Act. 15); and
Claim 20 as unpatentable over Rapaport, Slee, Radisch, and Boyd8
(Final Act. 16).
DISCUSSION
The dispositive issue raised by all five of the obviousness rejections is
whether the Examiner has established that one of ordinary skill in the art
would have had a reason to modify Rapaport's method of perfusing
oxygenated blood through a thrombus-occluded blood vessel by repeatedly
unsheathing and sheathing (i.e., expanding and contracting) Rapaport's
expanding scaffold, resulting in maceration and fragmentation of the
thrombus.
Overview of the Relevant Prior Art
Rapaport
Rapaport teaches that "occlusion of a cerebral artery in an acute
ischemic stroke is mostly due to thrombus formation" (Rapaport i-f 2), and
"[ fJailure to timely restore blood flow triggers a biochemical and metabolic
cascade ultimately leading to irreversible brain injury" (id. i-f 3). Rapaport
7 David Fiorella & Henry Woo, U.S. Patent Application Publication No.
2007 /0208367 Al, published September 6, 2007 ("Fiorella").
8 Stephen W. Boyd, US 6,629,953 Bl, issued October 7, 2003 ("Boyd").
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discusses several known methods of quickly restoring blood flow through an
affected artery-for example, by inserting a mesh-like expanding member
into the occlusion and exerting outward radial force against the occlusion to
remove or disrupt it and to provide a passage allowing blood flow through
the affected artery. Id. i-fi-14, 5, 8, 9. Rapaport notes that those known
methods are associated with various disadvantages, including trauma to the
blood vessel exhibiting the occlusion (id. i18), subsequent decreased blood
flow due to aggregation of dislodged fragments in the expanding member
(id.), and "undesired breaking up of the occlusion with significant fragments
being dislodged to proceed further into the bloodstream resulting in potential
brain damage" (id. i-f l 0).
To avoid these problems, Rapaport discloses "a method and apparatus
for passively perfusing oxygenated blood through an obstructing clot while
minimizing undesired radial force against the occlusion." Id. i-f 11. The
apparatus comprises "a tubular body expandable from an initial small
diameter state for manipulation adjacent, and/or through, the occlusion of
the small blood vessel and a second larger diameter state." Id. i-f 12. For
example, Rapaport discloses:
[A] device comprising a tubular body exhibiting a first small
diameter state for manipulation to, and through, the occlusion
of the small blood vessel, the device expandable to a second
large diameter state within the occlusion, the inner dimensions
of the second large diameter state being no more than 50% of
the diameter of the small blood vessel at the occlusion location,
the device presenting a conduit through the tubular body for
blood flow through the occlusion when in the large diameter
state.
Id. i-f 14. In addition, "[i]n some embodiments the device further comprises a
distal filtering extension coupled to a first end of the tubular body" (id.
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i-f 16), or a "clot retrieval device in communication with the tubular body and
exhibiting a diameter greater than 50% of the diameter of the small blood
vessel at the occlusion location" (id. i-f 18).
Slee
Slee discloses a method of restoring localized blood flow to a vascular
site occluded by a thrombus. Slee i-f 33. Using a microcatheter and a push
wire, a retrievable self-expanding apparatus is positioned within a blood
vessel occluded by a thrombus. The self-expanding apparatus, in its
volume-reduced form, is placed radially adjacent to the thrombus, with the
distal end of the self-expanding apparatus downstream of the thrombus. Id.
i-f 35. The distal segment of the apparatus is held in a fixed position by
holding the push wire stationary while the distal segment is released from its
volume-reduced form by withdrawing the microcatheter, exerting an
outward radial force on the thrombus and immediately re-establishing blood
flow through the vessel past the thrombus. Id.
Rad is ch
Radisch discloses a surgical device "useful for the incision and
dilation of a stenosis in the vasculature of a patient." Radisch i-f 2. Stenoses
"are typically caused by the build-up of atherosclerotic plaque on the inside
wall of an artery ... [and] can result in a partial, or even complete, blockage
of the artery." Id. i-f 4. Radisch's device comprises "a plurality of blade
segments that are mounted and aligned on a base member" and "the base
member is mounted on the external surface of an inflatable angioplasty
balloon." Id. i-f 8. "[W]hen the balloon is inserted into the vasculature ...
positioned across a stenosis and subsequently inflated, the blade segments
form an effective cutting edge that effectively conforms to the surface of the
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stenosis," so that "the stenosis can be incised to a substantially uniform
depth." Id. Radisch teaches that "[a]fter incision, the angioplasty balloon
can be further inflated to dilate the stenosis ... [and] subsequently deflated
to withdraw the blade segments from the stenosis." Id. i-f 15. "Once
deflated, the balloon and blade segments can be repositioned for treatment of
another stenosis or removed from the patient." Id. Alternatively, Radisch
teaches that"[ o ]nee deflated, the balloon [] can be re-inflated to repeat the
process, if desired." Id. i-f 34.
Obviousness of Claims 1-5 and 7-9
Claims 1-5 and 7-9 stand rejected as unpatentable over Rapaport,
Miller, Slee, and Radisch.
The Examiner finds that Rapaport's method meets most of the
limitations of claim 1, with one principal exception: Rapaport does not
disclose "macerating the thrombus by resheathing and unsheathing the
scaffold ... while the [scaffold] is held in a stationary position." Final Act.
6. In particular, the Examiner finds that Rapaport "teaches macerating the
thrombus by resheathing and unsheathing the scaffold ... but does not teach
that the resheathing and unsheathing occurs while the tip is held in a
stationary position." Id.
The Examiner finds, however, that Slee teaches "maintain[ing] the
position [of] the scaffold (4) while retracting the microcatheter (8) to
unsheath the scaffold ... and to maintain the position of the scaffold while
advancing the microcatheter (8) to resheath the scaffold." Id.
In addition, the Examiner finds that Radisch "teaches a method of
treating a thrombus by repeatedly expanding and collapsing a thrombus
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Application 13/172,778
treatment device (in this case, atherectomy blades mounted on a balloon
catheter) to incrementally treat a blockage within a vessel." Id.
The Examiner concludes that:
It would have been obvious to one of ordinary skill in the
art at the time the invention was made to modify the method
taught by Rapaport[], by repeating the steps of expanding and
collapsing the scaffold, as taught by Radisch[], and resheathing
and unsheathing the scaffold while maintain[ing] the scaffold in
a stationary position, as taught by Slee[], because all the
claimed elements were known in the prior art and one skilled in
the art could have combined the elements as claimed, by known
methods with no change in their respective functions, and the
combination would have yielded predictable results.
Id. at 6-7.
Appellants contend, in relevant part, that Rapaport "does not disclose
macerating a thrombus" (Appeal Br. 14), and in particular, does not
"disclose or suggest fragmentation of a thrombus to release embolic
particles" (id. at 17). Rather, Rapaport's device and method are "directed to
creating a temporary passage through the clot to allow blood flow, and [are]
not directed to clot breakup." Reply Br. 3. Appellants contend that
Rapaport's device "fully expands upon its first deployment ... and produces
its maximum flow passage through the thrombus upon a single expansion."
Id. Appellants further contend that "one having skill in the art would not
have been motivated to repeatedly expand and contract Rapaport's device
within a clot" because "subsequent expansions of Rapaport's device would
not achieve any additional clot breakup nor further increase the size of the
passage" nor "add any therapeutic advantage." Id.
We agree with Appellants that the Examiner has not established that
one of ordinary skill in the art would have had a reason to modify
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Rapaport's method in the manner proposed by the Examiner. As discussed
above, Rapaport's device and method are designed to avoid "undesired
breaking up of the occlusion with significant fragments being dislodged to
proceed further into the bloodstream resulting in potential brain damage."
Rapaport i-f 10. In other words, Rapaport's method is designed to minimize
maceration or fragmentation of the thrombus and release of embolic
particles. Thus, Rapaport limits the expansion diameter of the tubular body,
"minimizing undesired radial force against the occlusion" and the occluded
vessel. Id. i-f 11. That being the case, we agree with Appellants that one of
ordinary skill in the art would not have had a reason to combine Rapaport's
and Radisch's methods by repeatedly expanding and contracting Rapaport's
scaffold according to Radisch' s method of incising a stenosis, as doing so
would promote fragmentation of the thrombus-the very result that
Rapaport seeks to avoid.
Conclusion
The evidence of record does not support the Examiner's conclusion
that all the limitations of claims 1-5 and 7-9 would have been obvious over
the combined disclosures of the cited art. Accordingly, the rejection of
claims 1-5 and 7-9 as obvious over Rapaport, Miller, Slee, and Radisch is
reversed.
Obviousness of Claim 6
Claims 6 stands rejected as unpatentable over Rapaport, Miller, Slee,
Radisch, and Fiorella. Final Act. 8. Claim 6 depends from claim 1, and
further specifies that the occluded artery is a middle cerebral artery and the
distal end of the guide catheter is inserted into a middle cerebral artery or an
internal carotid artery.
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This rejection is premised on the Examiner's conclusion that the
subject matter of claim 1 would have been obvious over the combined
disclosures of Rapaport, Miller, Slee, and Radisch.
As the evidence of record does not support the Examiner's underlying
conclusion, and Fiorella does not remedy this deficiency, we will reverse the
rejection.
Obviousness of Claims 10, 12, 14-16, 18, and 19
Claims 10, 12, 14--16, 18, and 19 stand rejected as unpatentable over
Rapaport, Slee, and Radisch. Final Act. 8-15. Claims 10 and 18 are
independent claims, and like claim 1, require repeatedly resheathing and
unsheathing a stationary self-expandable scaffold, thereby facilitating
fragmentation of the thrombus to release embolic particles. Claims 12 and
14--16 depend from claim 10 and claim 19 depends from claim 18.
The Examiner's concludes that the subject matter of claims 10 and 18
would have been obvious over the combined disclosures of Rapaport, Slee,
and Radisch for the same reasons discussed in connection with claim 1.
As the evidence of record does not support the underlying Examiner's
conclusion with respect to claim 1, we will reverse this rejection as well.
Obviousness of Claim 17
Claims 17 stands rejected as unpatentable over Rapaport, Slee,
Radisch, and Fiorella. Final Act. 15. Claim 17 depends from claim 10, and
further specifies that the occluded artery is a middle cerebral artery and the
distal end of the guide catheter is inserted into a middle cerebral artery or an
internal carotid artery.
This rejection is premised on the Examiner's conclusion that the
subject matter of claims 1 and 10 would have been obvious over the
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combined disclosures of Rapaport, Slee, and Radisch, for the same reasons
discussed in connection with claim 1.
As the evidence of record does not support the Examiner's underlying
conclusion, and Fiorella does not remedy this deficiency, we will reverse the
rejection.
Obviousness of Claim 20
Claims 20 stands rejected as unpatentable over Rapaport, Slee,
Radisch, and Boyd. Final Act. 16. Claim 20 depends from claim 18, and
further specifies extracting the core portion of the thrombus by inserting a
second self-expandable scaffold into the microcatheter after removal of the
first expandable scaffold.
Again, this rejection is premised on the Examiner's conclusion that
the subject matter of claims 1 and 18 would have been obvious over the
combined disclosures of Rapaport, Slee, and Radisch, for the same reasons
discussed in connection with claims 1 and 18.
As the evidence of record does not support the Examiner's underlying
conclusion, and Boyd does not remedy this deficiency, we will reverse the
rejection.
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SUMMARY
The rejection of claims 1-5 and 7-9 as unpatentable over
Rapaport, Miller, Slee, and Radisch is reversed;
The rejection of claim 6 as unpatentable over Rapaport, Miller,
Slee, Radisch, and Fiorella is reversed;
The rejection of claims 10, 12, 14--16, 18, and 19 as
unpatentable over Rapaport, Slee, and Radisch is reversed;
The rejection of claim 17 as unpatentable over Rapaport, Slee,
Radisch, and Fiorella is reversed; and
The rejection of claim 20 as unpatentable over Rapaport, Slee,
Radisch, and Boyd is reversed.
REVERSED
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