IN RE: Bard Implanted Port Catheter Products Liability Litigation

1
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
WO
IN THE UNITED STATES DISTRICT COURT
FOR THE DISTRICT OF ARIZONA
IN RE: Bard Implanted Port Catheter
Products Liability Litigation
–––––––––––––––––––––––––––––––––
Robert Cook,
Individual Plaintiff,
v.
Becton Dickinson and Company, et al.,
Defendants.
MDL No. 3081
No. CV-23-01975-PHX-DGC
ORDER
Expert Witness Benjamin Musher, M.D.
This multidistrict litigation (“MDL”) involves thousands of personal injury cases
related to implanted port catheters (“IPCs” or “ports”) designed, manufactured, and
marketed by Defendants Becton Dickenson and Company, C. R. Bard, Inc., Bard Access
Systems, Inc., and Bard Peripheral Vascular, Inc. (collectively, “Defendants” or “Bard”).
Plaintiff has filed a motion to exclude the expert opinions of Benjamin Musher, M.D.
Doc. 5811. The motion is fully briefed and no party requests oral argument. See
Docs. 5811, 6244, 6411. The Court will grant the motion in part.
I. Background.
An IPC is a medical device surgically implanted under the skin to provide repeated
access to a patient’s vascular system without the need for multiple needlesticks into
peripheral veins. IPCs are used to deliver chemotherapy and immunotherapy medication,
Case 2:23-md-03081-DGC Document 6986 Filed 01/29/26 Page 1 of 8

2
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
intravenous fluids, blood transfusions, and parenteral nutrition. IPCs can remain in place
for weeks, months, or even years until treatment is completed.
IPCs consist of a port and a catheter. The port is a small reservoir disc with a self-
sealing silicone center where a needle can be inserted to deliver medication. The port
typically is implanted beneath the chest skin and below the collarbone. Port bodies vary
in shape and size and are made of plastic, silicone, or titanium. The port is attached to a
catheter, which is a thin flexible tube for delivery of the medication to a vein. The catheter
is tunneled under the skin to an insertion point in a central vein. Catheters vary in width
and are made of silicone or polyurethane. IPCs typically are implanted by an interventional
radiologist or a vascular surgeon. A nurse or other medical professional then accesses the
IPC to inject the medication, which flows from the port to the catheter and into the vein.
This MDL involves multiple versions of Bard IPCs, each of which received
premarket clearance from the Food and Drug Administration (“FDA”). Bard IPCs contain
barium sulfate, a radiopaque substance that can be seen on diagnostic imaging such as
X-ray, CT, and MRI scans. Several Bard IPCs are manufactured using polyoxymethylene
(“POM”), an acetal thermoplastic polymer, in the construction of the port. Many Bard
IPCs have a port with raised palpation bumps on the silicone center, which help identify
these IPCs as power-injectable devices.
Each Plaintiff in this MDL had a Bard IPC implanted in his or her body, and claims
it was defective and caused serious injury. Plaintiffs allege that the barium sulfate in the
IPC degrades the mechanical integrity of the catheter, leading to surface irregularities that
cause catheter fracture, infection, and blood clots. Plaintiffs further allege that Bard’s
manufacturing process for the POM-containing IPCs lacks adequate measures to stabilize
the POM to prevent oxidative degradation, which causes cracks, fissures, and other
physical defects in the polymer and increases the risk of fracture, infection, and thrombosis.
Plaintiffs also allege that the palpation bumps on the power-injectable IPCs cause undue
compression stress on the tissue surrounding the port, leading to ulceration and tissue
necrosis. See Docs. 23, 1889.
Case 2:23-md-03081-DGC Document 6986 Filed 01/29/26 Page 2 of 8

3
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
Plaintiffs claim that safer alternative designs and manufacturing processes were
available to Bard and that Bard IPCs are more dangerous than other available treatment
options. Plaintiffs assert a host of state law claims, including design and manufacturing
defects, failure to warn, breach of warranty, misrepresentation, concealment, and consumer
fraud and unfair trade practices. See Docs. 23, 1889.
Bard disputes Plaintiffs’ allegations and contends its IPCs are safe and effective and
that the medical community is aware of risks associated with IPCs. Bard further contends
that various factors impact the performance and wear of IPCs, including where the catheter
is inserted and how well the device is maintained by medical professionals and the patient.
See Docs. 23, 2023-1.
Plaintiff Robert Michael Cook brings his lawsuit in this MDL. Doc. 216 (Case No.
CV-23-01975-PHX-DGC). On August 24, 2022, Plaintiff Cook had a Bard port implanted,
and he subsequently suffered from an infection. Id. at 4. Plaintiff raises claims typical of
this MDL, alleging the infection was caused by the Bard port. Id. at 5.
Defendants have identified Benjamin Musher, M.D. as an expert witness in the
Cook case. Dr. Musher is a Professor of Medicine in the Hematology-Oncology Division
of Baylor College of Medicine, and the Director of the Gastrointestinal Cancer Program at
Baylor’s NCI-designated Dan L Duncan Comprehensive Cancer Center. Doc. 5811-1 at
54, 76. He is certified by the American Board of Internal Medicine in Internal Medicine
and Medical Oncology and is a member of the American Society of Clinical Oncology,
among other medical societies. Id. at 20, 54, 78. He specializes in gastrointestinal
malignancies and has treated thousands of patients with ports. Id. at 54-55. Plaintiff moves
to exclude certain opinions of Musher under Federal Rule of Evidence 702.
II. Legal Standard.
Rule 702 provides that “[a] witness who is qualified as an expert by knowledge,
skill, experience, training, or education may testify in the form of an opinion” if the
proponent of the expert’s testimony “demonstrates to the court that it is more likely than
not that” (a) “the expert’s scientific, technical, or other specialized knowledge will help the
Case 2:23-md-03081-DGC Document 6986 Filed 01/29/26 Page 3 of 8

4
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
trier of fact to understand the evidence or to determine a fact in issue,” (b) “the testimony
is based on sufficient facts or data,” (c) “the testimony is the product of reliable principles
and methods,” and (d) “the expert’s opinion reflects a reliable application of the principles
and methods to the facts of the case.” Fed. R. Evid. 702(a)-(d). The proponent of the
expert testimony must show by a preponderance of the evidence that the testimony satisfies
each of these requirements. Fed. R. Evid. 104(a); Fed. R. Evid. 702 advisory committee’s
note to 2023 amendment (“[T]he rule has been amended to clarify and emphasize that
expert testimony may not be admitted unless the proponent demonstrates to the court that
it is more likely than not that the proffered testimony meets the admissibility requirements
set forth in the rule.”); Engilis v. Monsanto Co., 151 F.4th 1040, 1050 (9th Cir. 2025)
(“Consistent with the 2023 amendment, our precedent establishes that Rule 702 requires a
proponent of expert testimony to demonstrate each of the requirements of Rule 702 by a
preponderance of the evidence.”).
The Court acts as a gatekeeper to ensure that expert testimony satisfies Rule 702.
Daubert v. Merrell Dow Pharms., Inc., 509 U.S. 579, 597 (1993). The Court’s task is not
to decide whether the expert is right or wrong, but to ensure the proposed opinions satisfy
Rule 702. Alaska Rent-A-Car, Inc. v. Avis Budget Grp., 738 F.3d 960, 969-70 (9th Cir.
2013); Engilis, 151 F.4th at 1050. If the proponent does not meet its Rule 702 burden, the
expert testimony is not admissible. See Davis v. McKesson Corp., No. CV-18-1157-PHX-
DGC, 2019 WL 3532179, at *3 n.2 (D. Ariz. Aug. 2, 2019) (“[T]he Court may admit expert
opinions only if it can determine, under Rule 104(a), that Plaintiffs have shown each of the
Rule 702 requirements to be satisfied by a preponderance of the evidence.”).
III. Diagnosis Opinion.
Plaintiff argues Musher, an oncologist and not an infectious disease doctor, is not
qualified to diagnose Plaintiff’s infection. Plaintiff argues “[i]t is not entirely clear whether
Dr. Musher independently diagnosed Plaintiff with a port infection or is merely relaying
the diagnosis made by Plaintiff’s treating physicians.” Doc. 5811 at 4. Plaintiff contends
Case 2:23-md-03081-DGC Document 6986 Filed 01/29/26 Page 4 of 8

5
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
Musher may only relay Plaintiff’s diagnosis from Plaintiff’s doctors – he may not make
the diagnosis himself. Id.
Defendants confirm that Musher has not diagnosed Plaintiff with a port-related
MSSA infection. Doc. 6244 at 5. Instead, Musher incorporates into his testimony the
undisputed fact that Plaintiff was diagnosed with an MSSA infection stemming from his
port. See id. at 6 (“There is no dispute that [Plaintiff] had an infection and that the infection
was caused by MSSA.”); see also Doc. 5811-1 at 6 (Musher’s report relying on Plaintiff’s
medical records confirming Plaintiff’s infection was MSSA). Plaintiff acknowledges that
Musher may testify about these undisputed facts. See Doc. 5811 at 4. Defendants’
clarification will be accepted by the Court, and this issue therefore provides no basis for
exclusion of Musher’s testimony.
IV. Causation Opinion.
Plaintiff seeks to exclude Musher’s opinion that Plaintiff’s infection was “most
likely” introduced during deaccessing. Doc. 5811 at 6. Plaintiff contends Musher’s
opinion must be excluded because it was not timely disclosed, he is not qualified to provide
it, and he did not perform a differential diagnosis. Id. at 6-12. Because the Court accepts
one of these arguments it need not address the other two.1
Plaintiff argues Musher is unqualified to opine on the “most likely” source of
Plaintiff’s infection because he does not possess “specialized training in or knowledge of
infectious diseases” and was not otherwise Plaintiff’s treating physician. Doc. 5811 at 9.
Plaintiff relies on Berk v. St. Vincent’s Hosp. & Med. Ctr., 380 F. Supp. 2d 334 (S.D.N.Y.
2005), for the proposition that Plaintiff must exhibit specialized training or knowledge in
infectious diseases, or otherwise be Plaintiff’s treating physician, to render his causation
opinion. See id. at 352 n.24 (orthopedic surgeon likely not qualified to opine on the cause
of infection where he lacked “any unique training or qualifications,” but causation opinion
admitted because he was the treating physician).
1 The Court reminds Plaintiffs’ counsel to eliminate snide comments from briefing or
argument. See Doc. 6411 at 2 (saying Musher “sputtered out his half-baked causation
opinion for the first time at deposition”).
Case 2:23-md-03081-DGC Document 6986 Filed 01/29/26 Page 5 of 8

6
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
Defendants respond that “courts in the Ninth Circuit have consistently held that Rule
702 ‘impose[s] no requirement that an expert be a specialist in a given field, although there
may be a requirement that he or she be of a certain profession, such as a doctor.’”
Doc. 6244 at 7 (quoting Doe v. Cutter Biological, Inc., 971 F.2d 375, 385 (9th Cir. 1992)).
They contend Musher need not be an infectious disease physician to render his causation
opinion, and that “lack of particularized expertise goes to the weight accorded [an expert’s]
testimony, not to the admissibility of her opinion as an expert.” Id. (quoting Marshall v.
RS 2018 Float, LLC, No. 22-35899, 2024 WL 637487, at *1 (9th Cir. Feb. 15, 2024)).
The Court is not persuaded by Defendants’ arguments. Clearly, a medical doctor’s
qualification to opine in one area “does not mean he is qualified to testify on all other
medical topics.” Gorney v. Safeway Inc., No. CV-23-01413-PHX-SHD, 2025 WL
2586133, at *5 (D. Ariz. Sept. 8, 2025) (citation omitted). Because Musher is not an
infectious disease physician, Defendants must show by a preponderance of the evidence
that his knowledge, skill, experience, training, or education equip him with the specialized
knowledge to opine on the original cause of Plaintiff’s infection. Fed. R. Evid. 702.
Defendants have not met this burden. They cite Musher’s qualification as a board-
certified oncologist, but a medical license is not enough to opine on the cause of any
medical issue. See Alsadi v. Intel Corp., No. CV-16-03738-PHX-DGC, 2019 WL
4849482, at *4 (D. Ariz. Sept. 30, 2019) (explaining “the mere fact that Dr. Garcia is a
qualified pulmonologist who treated [the plaintiff] does not render his opinions on
causation admissible under Rule 702[.]” (citation omitted)).
Defendants rely primarily on Musher’s clinical experience in managing patients
with IPCs, in addressing both port-related and non-port related infections, and in
collaborating with other doctors on treating port-related infections, as well as his medical
decision-making for patients with port-related infections, including whether ports should
be removed. Doc. 6244 at 6-7. But Musher’s management of port patients and their
infections, and his involvement in decision-making about port removal, does not show he
has the knowledge or experience to testify as an expert on the original source of a port-
Case 2:23-md-03081-DGC Document 6986 Filed 01/29/26 Page 6 of 8

7
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
related infection. Treating an infection is not the same as determining its originating cause,
and Defendants offer no evidence that Musher’s medical practice involves determining the
causes of infections.
The Court finds no support for Musher’s qualification from its own review of his
report and curriculum vitae. As a hematologist oncologist, Musher primarily treats patients
with gastrointestinal (“GI”) cancers. Doc. 5811-1 at 54. His research, publications, and
teaching focus on GI cancers. Id.; see also id. at 76, 79-80, 86-92. Musher’s clinical
experience involving IPCs centers around providing therapy to his GI cancer patients,
which requires him to monitor his patients’ ports for complications, including infections,
and treat them accordingly. Id. at 55. But Musher’s report and CV nowhere state that he
determines the causes of port-related infections.2
Courts have recognized that a physician’s skill and experience in treating an illness
does not necessarily mean the doctor can determine its cause. See, e.g., Wilson v. Pinnacle
Foods Inc., No. 3:19-CV-229-BJB, 2022 WL 419595, at *6 (W.D. Ky. Feb. 10, 2022) (“Dr.
Cumbo never connects his general experience treating Listeria and enteritis with any
experience deducing their causes. Causation, not clinical diagnosis and treatment, is the
question at issue. And ‘[t]he ability to diagnose medical conditions is not remotely the
same,’ . . . ‘as the ability to deduce . . . in a scientifically reliable manner, the causes of
those medical conditions.’” (citation omitted)). Courts within the Ninth Circuit have
similarly excluded causation opinions of experts who have experience treating a medical
condition but cannot show experience deducing their cause. See, e.g., Stambolian v.
Novartis Pharms. Corp., No. CV 12-04378 BRO FMOX, 2013 WL 6345566, at *6 (C.D.
Cal. Dec. 6, 2013) (finding doctor unqualified to render causation opinion where the
2 The Court notes one publication co-authored by Musher on gastrointestinal infections.
See Doc. 5811-1 at 86 (citing Daniel M. Musher & Benjamin L. Musher, Contagious Acute
Gastrointestinal Infections, 351 New England J. Med. 2417 (2004)). The parties have not
provided this article to the Court for review and it is not readily accessible. The article’s
abstract suggests, however, that the article does not discuss port-related infections. See id.
(“This article examines direct human-to-human spread of acute gastrointestinal illness,
defined as a syndrome of vomiting, diarrhea, or both that begins abruptly in otherwise
healthy persons and is most often self-limited.”).
Case 2:23-md-03081-DGC Document 6986 Filed 01/29/26 Page 7 of 8

8
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
plaintiff had “only shown that Dr. Herford was qualified to treat her as a patient suffering
from [the medical condition at issue],” but there was “not enough evidence to demonstrate
that Dr. Herford [was] qualified to opine within a reasonable degree of medical certainty
that there [was] a connection between [the argued cause] and Plaintiff’s [medical
condition]”).
The cases cited by Defendants are distinguishable.
In Doe, 971 F.2d 375, the Ninth Circuit found a surgeon qualified as an expert on
blood products and hematology based on both his experience and study of medical
literature. See id. at 385-86. Here, the Court finds no similar support for Musher’s
causation opinion.
In Marshall, 2024 WL 637487, the Ninth Circuit affirmed a district court’s
exclusion of proposed expert opinions on railcar design, modification, and loading because
“beyond general references to their broad areas of expertise, [the experts] did not provide
any link between their expertise and their opinions and methodology.” Id. at *1. Similarly,
Defendants have not provided any link between Musher’s expertise in hematology
oncology and the skill needed to determine the original source of an infection.
Finally, in Gorney, 2025 WL 2586133, the expert was not rendering a causation
opinion. The cause of the injury – an accident – was not in dispute. Id. at *1.
Defendants have not shown by a preponderance of the evidence that Musher has the
knowledge, skill, experience, training, or education to opine on the most likely cause of
Plaintiff’s infection. The Court therefore will exclude this opinion.
IT IS ORDERED that Plaintiff’s motion to exclude the opinions of Benjamin
Musher, M.D. (Doc. 5811) is granted in part and denied in part. Dr. Musher cannot
opine that deaccessing was the most likely source of Plaintiff Cook’s infection.
Dated this 29th day of January, 2026.
David G. Campbell
Senior United States District Judge
Case 2:23-md-03081-DGC Document 6986 Filed 01/29/26 Page 8 of 8