In December 2020, Diana Dyer “was surgically implanted with an Aris™ Trans-Obturator Sling System (hereinafter the ‘Aris’), a pelvic mesh product and medical device designed, manufactured, and marketed by Defendants,” which “was intended to treat pelvic organ prolapse and stress urinary incontinence.”
Dyer claimed that she “has suffered, and continues to suffer, debilitating injuries” “as a result of being surgically implanted with Defendants’ unreasonably dangerous defective pelvic mesh device.”
Dyer retained as a general and specific causation expert Dr. Neeraj Kohli, “an active surgeon, teacher, entrepreneur, inventor, lecturer, and researcher.” Coloplast sought to exclude the opinions of Kohli.
Gynecology Expert Witness
Dr. Neeraj Kohli is a board certified Ob/Gyn and fellowship trained urogynecologist practicing strictly in the field of Urogynecology and Reconstructive Pelvic Surgery since 1997.
Kohli has extensive experience with pelvic repair surgery of all types with and without biologic or synthetic materials.
Discussion by the Court
Kohli offered the following general causation opinions: (1) the “inherent properties of polypropylene mesh make it an unsuitable material for placement in the transobturator space,” (2) the Aris is “defective in its technique and [its] material design,” (3) the Aris “has an unacceptably high rate of mesh exposure/erosion, dyspareunia, and chronic pain complications,” (4) the Aris’s IFU “and brochure warnings were inadequate to allow physicians to make responsible treatment choices and allow patients to give proper informed consent,” (5) Coloplast did not perform adequate safety testing on the Aris and failed to warn about known “complications related to transobturator mesh placement,” (6) there “are safer alternatives that are equally or more effective” than the Aris, and (7) the risks of the Aris outweigh its benefits.
As to specific causation, Kohli opined that the “vaginal/groin pain and persistent [overactive bladder]/incontinence suffered by Dyer is the direct result of the defects described throughout this report.”
Analysis
Coloplast challenged the reliability of Kohli’s specific causation opinions. Coloplast also argued that many of Kohli’s general causation opinions are unreliable, unhelpful, or irrelevant. Finally, Coloplast contended that the Court should exclude Kohli’s opinions “stating legal standards, conclusions, and terms of art, as well as opinions about Coloplast’s knowledge, state of mind, or conduct.”
A. Kohli’s Case-Specific Opinions
Coloplast argued that Kohli’s case-specific opinions are not reliable because he based his differential diagnosis on a cherry-picked selection of medical records and did not adequately rule out alternative possible causes of Dyer’s injuries. The Court is not persuaded.
Coloplast argued that Kohli’s specific causation opinions are unreliable because he: (1) failed to adequately consider medical records that did not support his opinion, (2) only reviewed the medical records provided to him by Dyer’s counsel, and (3) did not conduct a pelvic exam of Dyer. None of the alleged factual discrepancies or mischaracterizations warrant excluding Kohli’s opinions.
Coloplast also argued that Kohli’s differential diagnosis is unreliable because he did not adequately rule out alternative possible causes of Dyer’s injuries. The Court disagreed.
Kohli “ruled in the mesh as a primary cause because Dyer’s pelvic pain symptoms began . . .immediately after mesh implantation and are unique to mesh placement in the vagina and particularly the Aris”
transobturator sling.” Kohli also noted that Dyer “has no significant medical, surgical, or social history or risk factors contributing to her present mesh complication symptoms or current pelvic floor complaints.”
Coloplast argued that Kohli failed to adequately rule out lumbar disc and sacroiliac joint issues, sciatica, and surgical positioning as being sources of Dyer’s pelvic pain. However, Kohli explained that he ruled out lumbar disc involvement as it typically would not cause the symptoms experienced by Dyer immediately following mesh implantation and as post-surgical therapies to the lumbar area were not effective. With respect to sacroiliac joint issues and sciatica, Coloplast did not challenge Kohli’s assertion that Dyer denied suffering from such problems prior to the mesh implantation.
As a result, the Court found Kohli’s methodology regarding the cause of Dyer’s pelvic pain sufficiently reliable.
B. Kohli’s General Causation Opinions
1. Surgical Technique
Kohli opined that the Aris “was defective in its technique and it[s] material design. This includes blind insertion of a permanent device through the transobturator space, through and in close proximity to vital anatomic structures including muscles and nerves.”
Coloplast argued that “Kohli’s criticisms about the Aris’ transobturator approach amount to no more than personal opinions on a particular surgical technique, which does not speak to a ‘defect’ in the Aris that resulted in injury,” and, therefore, are irrelevant. The Court disagreed.
A comparison of the risks associated with implanting in the transobturator region as opposed to the retropubic region is relevant to the defect analysis because the location of the device within the body and the method of insertion are inherent attributes of the device’s design. Accordingly, the Court held that Kohli’s opinions regarding the transobturator approach are not irrelevant.
Coloplast further argued that “Kohli’s blind placement opinion is also divorced from any scientifically reliable methodology.” The Court is not persuaded. Here, Coloplast has not demonstrated that there is too great an analytical gap between the studies Kohli cited and his opinion.
2. Defective Design
Kohli opined that “the inherent properties of polypropylene mesh make it an unsuitable material for placement in the transobturator space. . . . This is especially true of the Coloplast mesh given its increased weight and stiffness.”
Coloplast argued that the Court should exclude Kohli’s opinion that the Aris is defectively designed because “Kohli does not provide support for his opinions on Aris’ design properties or that the Aris is unsuitable for use in the transobturator space.” However, Kohli cited multiple scientific articles to support his opinions regarding the properties of polypropylene mesh and its unsuitability for use in the transobturator space. Accordingly, Coloplast has not demonstrated that Kohli’s opinions are unreliable.
Coloplast further argued that Kohli’s opinions are unhelpful to the jury because Kohli “fails to provide a measuring stick for assessing the propriety of Aris’s specifications, and instead advances a ‘trust me, I’m a doctor’ approach.”
To succeed on any of her claims, Dyer must prove that the Aris “is defective or unreasonably dangerous.” Kohli explained the basis for his opinion that the properties of polypropylene mesh make it unsuitable for use in the transobturator space and cites to multiple scientific studies.
Kohli’s opinion logically advances a material aspect of Dyer’s case: whether the Aris is defective or unreasonably dangerous. This information is “beyond the understanding of the average lay person.”
3. Unacceptably High Rate of Complications
Kohli opined that the Aris “has an unacceptably high rate of mesh exposure/erosion, dyspareunia, and chronic pain complications.”
Coloplast argued that Kohli’s opinion is unreliable because “Kohli
identified no methodology (much less a reliable one) for determining what constitutes an acceptable versus ‘unacceptably high’ rate of complications.”
Kohli did not identify the alleged complication rate of the Aris or explain the scientific basis for his opinion that the Aris’ rate is “unacceptably high.” Accordingly, the Court found that Kohli’s opinion on this issue is unreliable and is excluded.
4. Safer Alternatives
Kohli opined that “the Burch procedure, autologous fascial slings, and appropriate retropubic slings are safer than the Aris.”
Coloplast argued that Kohli’s opinions regarding the Burch procedure and autologous fascial slings are irrelevant as they are not safer alternative product designs for a transobturator sling but are “entirely different surgeries.” The Court disagreed. Kohli’s opinions regarding safer alternative procedures are relevant to the question of whether the risks of the Aris outweigh the benefits.
Alternatively, Coloplast argued that Kohli’s opinions are unreliable. The Court is not persuaded.
Coloplast further argued that “Kohli’s ‘safer alternative’ opinions about polypropylene retropubic slings and PVDF mid-urethral slings are unreliable.” The Court disagreed.
Coloplast’s challenge to “the sufficiency of scientific literature on which” Kohli relies “is a matter that more properly goes to the weight of the evidence and can be probed during cross-examination.”
Coloplast also argued that Kohli’s opinions regarding PVDF mesh mid-urethral slings should be excluded because such slings are not available in the United States. Under Florida law, “a Plaintiff need not demonstrate the existence of a reasonable alternative design for a strict liability design defect claim.” Accordingly, the fact that PVDF mid-urethral slings were not available in the United States at the time of Dyer’s surgery did not render Kohli’s opinion irrelevant in this case.
The Court found that Kohli’s opinions on PVDF mid-urethral slings are relevant to the issue of whether “alternative safer designs exist.”
5. Inadequate Safety Testing
Kohli opined that Coloplast failed to perform adequate safety testing on the Aris. Coloplast argued that Kohli is unqualified to opine on the matter and, alternatively, that his opinion is unreliable.
Although Kohli is the chief medical officer of a medical device company, there is no indication that he has experience in testing medical devices. Accordingly, the Court found that Kohli is not qualified to testify as to the adequacy of Coloplast’s safety testing.
In any event, even if Kohli were qualified to opine on the adequacy of the safety testing, Kohli has not offered any support for his conclusory opinion that Coloplast “rushed to market with Aris to avoid loss of market share without adequate safety testing.”
6. Deficient IFU
Kohli opined that the Aris’ Instructions for Use (“IFU”) “were inadequate to allow physicians to make responsible treatment choices and allow patients to give proper informed consent.”
Coloplast argued that Kohli is not qualified to render an opinion on the IFU and, in any event, that Kohli has not provided any “basis for reaching the conclusion that the purported inadequacy of Aris’s IFU renders the device ‘not reasonably safe’ or makes it ‘impossible’ for implanting physicians to obtain informed consent.”
The Court found Kohli qualified to opine on the adequacy of the Aris’ IFU as, in addition to his surgical experience, Kohli “assists in the drafting and editing of IFUs” at a medical device company.
However, Kohli did not provide an adequate basis for, or a reliable methodology used, in reaching his conclusions that the inadequacy of the instructions and warnings renders Aris ‘not reasonably safe’ and made it ‘impossible’ to obtain informed consent.
7. Legal Conclusions, Summaries, and Opinions on Coloplast’s Knowledge, Intent, or State of Mind
Finally, Coloplast asked the Court to exclude Kohli’s opinions to the extent they contain impermissible legal conclusions, summaries, and speculation on Coloplast’s corporate intent, knowledge, or state of mind.
The Court held that Kohli will not be permitted to testify as to the knowledge, state of mind, or corporate intent of [Coloplast] or summarize corporate documents but will be allowed to testify as to his review of the corporate documents solely for the purpose of explaining the basis of his opinions. Kohli was also not precluded from offering testimony that uses terms that do not have a separate, distinct, and specialized meaning in the law.
Held
The Court granted in part and denied in part Defendant Coloplast Corp.’s motion to exclude the testimony of Neeraj Kohli, M.D.
Key Takeaway
Experience as a surgeon alone does not translate into experience with or knowledge about the appropriate testing a medical device manufacturer should undertake when preparing a product for the market.
Case Details:
| Case Caption: | Dyer V. Coloplast Corp. |
| Docket Number: | 8:24cv2867 |
| Court Name: | United States District Court, Florida Middle |
| Order Date: | July 02, 2026 |
Leave a Reply