On Use of the New and Non-Standard 510(k) Sternotomy Closure Device, VariTrax, by U.S. Cardiothoracic Surgeons — A Safe and Non-Inferior Innovation, or A Patient Safety and Medical Tort Liability?
On January 30, 2024 the United States Food and Drug Administration (FDA) provided a company named CircumFix Solutions, Inc. with a 510(k) “clearance” to market a new and non-standard medical device, called VariTrax (K232986). The 510(k) clearance was announced by the FDA in a public Pre-Market Notification (PMN) document, published by that agency. This device was invented for closure of sternotomy incisions in open heart surgery patients — and the VariTrax’s FDA cleared “Indications for Use” states: “The VariTrax Sternal CircumFixation system is indicated for primary or secondary closure/repair of the sternum following sternotomy or fracture of the sternum to stabilize the sternum and promote fusion.”
CircumFix Solutions, Inc. is a subsidiary of a large German multinational company named Evonik Industries — and is funded by venture capital from Evonik Venture Capital.
The “sternal cerclage” surgical technique relied on by the new VariTrax device is similar to the currently used standard technique, which utilizes stainless steel wire sutures. This stainless steel wire closure technique is used by the vast majority of cardiac surgeons across the United States, and globally. However, the VariTrax device, itself, is NOT a standard device for sternotomy closure—and FDA’s 510(k) clearance of this device is not a standardizing mechanism. In other words, sternal cerclage with stainless steel wires, NOT with VariTrax, is the standard and established way in which the vast majority of sternotomy incisions are closed in patients undergoing open heart surgery.
A word on standardization of medical technologies and treatments: The main sign that a new medical technology or treatment has been standardized is its widespread adoption and use in clincal practice, across the US. When a great majority of practitioners use a certain product or treatment, it is generally accepted as a standard by the specialty. But proper standardization of a medical technology or treatment, especially in high risk clinical areas like open heart surgery, generally occurs through methodical clinical trials demonstrating safety, efficacy and non-inferiority to pre-existing treatment modalities, where they exist. Guidelines and consensus statements issued by professional guilds are typically based on such trials or based on majority consenssus, when clinical trials have not been done. In the case of VariTrax, only a very small fraction of surgeons are currently using this device for sternotomy closure — and there have been no clinical trials to establish its safety, efficacy and non-inferiority. There are no society consensus statements or guidelines adopting VariTrax’s use as an alternative sternal cerclage device to standard stainless steel wire sutures. So, its fair to say that use of the VariTrax 510(k) medical is NOT currently a standard of care in sternotomy closure.
To be clear, when FDA provides a 510(k) clearance to any new medical device the agency is explicitly authorizing the manufacturer of the device to market and sell its product to U.S. consumers — as it has in the case of VariTrax. BUT this 510(k) clearance from FDA is NOT creating a new standard of care in medicine or surgery — nor is FDA’s 510(k) clearance in any way obviating the need for full disclosure and patient informed consent required by federal/state statutes, about the fact that a given 510(k) device used in patient care is new and non-standard. Even if FDA’s 510(k) process determines that a new medical device is “substantially equivalent” to a predicate device that is a standard of care, this FDA determination is not what would convert the new 510(k) device into a new standard — specifcally, because FDA does NOT have jursidiction over creating or changing medical standards of care. To reiterate for clarity, a 510(k) clearance from FDA does not and can not create new standards of care — and it does not and can not overrule medical ethical and state/federal legal statutes governing the requirement for full disclosure of risk or patient informed consent about the novelty and non-standard nature of a new device; most especially in high-risk clinical areas like open heart surgery.
It is also well-established that a 510(k) clearance from FDA does NOT operate on the premise of establishing epidemiological evidence of safety, efficacy and non-inferiority of new and non-standard devices to pre-existing standards of care, or even the claimed predicates. Rather, 510(k) operates on a rather subjectively adjudicated notion of “substantial equivalency to a predicate device”, based primarily on a manufacturer’s rhetorical claims, variable data and postulations — not based on an evidence-based adjudication of clinical outcomes, safety or efficacy. It stands to reason, therefore, that whenever any clinician or medical center uses a new and non-standard 510(k) cleared medical device in the care of patients, or when a manufacturer markets a new and non-standard 510(k) device, there is a legal duty to disclose this risk and obtain informed consent from the treated patient (and likely the patients’ insurers — especially Medicare). A 510(k) clearance does not mean a new device is a standard-of-care, or that it is necessarily safe, effective and non-inferior to a pre-existing standard, or to its claimed predicate — nor is it a guarantee of reimbursement by health insurers. In fact, there are many examples of 510(k) cleared medical devices, used on- or off-label, that insurers would not knowingly reimburse for. As of this writing it is unclear if any insurers, including Medicare, would knowingly reimburse for use of the new and non-standard medical device, Varitrax, in the care of high risk adult cardiac surgery patients.
What makes VariTrax a non-standard device is, in part, its novelty. As of this writing, CircumFix has advertised a mere 200 VariTrax implantations in high-risk human subjects undergoing open heart surgery in the U.S., out of approximately 700,000 performed annually. That is only 0.029% of open heart surgeries performed in the US — hardly a fraction that would justify calling VariTrax sternal cerclage a standard of care. Additionally, at least some of, if not all of these VariTrax implantations in human subjects may have been performed outside the guardrails of properly designed clinical trials and IRB guided patient informed consent. In fact, 100 of these VariTrax human subject implants performed in the U.S. were anecdotally performed (i.e., outside of any clinical trial setting), by one single surgeon at St. Alphonsus Medical Center in Boise, Idaho — that’s 50% of the VariTrax devices used in the US to date, has been by one surgeon. Based on that surgeon’s publication on CircumFix’s website, It remains unclear if that surgeon disclosed that VariTrax is new and non-standard, or if he obtained direct informed consent from his patients for implantation of this medical device in their bodies. One hopes that he did.
The core issue that makes the new VariTrax sternotomy closure device non-standard is that, instead of the standard stainless steel wire sutures used for sternal cerclage in the vast majority of sternotomy closures, VariTrax is made of a plastic material known as VESTAKEEP® PEEK made by Evonik Industries. Polyether ether ketone (PEEK), is basically a plastic material, which Evonik Industries has been developing and marketing for use in medical devices in the US and globally. Of course Evonik claims that PEEK is sufficiently stable, biologically inert and resistant to infection to justify its use as a component of implantable medical devices, such as VariTrax. While this claim is probably true, the use of PEEK instead of stainless steel wire sutures, specifically for sternotomy closure/sternal cerclage, has not been compared in appropriately designed side-by-side clinical trials in human subjects to establish its clinical non-inferiority. In my opinion, even the sheer volume of foreign PEEK material in VariTrax implanted into the patient, compared to the amount of standard foreign body stainless steel material implanted to achieve sternal cerclage, appears to be significantly greater — thus, theoretically, providing a much greater surface area for bacterial contamination and seeding of the sternotomy closure incision closed with VariTrax. But, I digress.
Most cardiothoracic surgeons worldwide recognize that stainless steel wire cerclage closure of sternotomy incisions is, in fact, the global standard of care for sternotomy closure. For anyone to formally deny this fact, is pure wishful thinking or belligerent fiction. It’s also true that most cardiothoracic surgeons recognize that this current standard has significant limitations, including wire breakage and inconsistent/operator dependent geometric/tensile instability. So, to be sure, there is ample room for innovation and improvement in the sternotomy closure clinical area — as some have suggested. Circumfix Solutions, Inc. and Evonik are hoping to capitalize on this need for improvement in their attempt to market VariTrax in the sternotomy closure arena by using FDA’s 510(k) “clearance” as the pathway to market access. The FDA has, in fact opened the door to CircumFix/Evonik’s business goal by granting CircumFix its 510(k) clearance. And CircumFix is doing so by publicly advertising VariTrax as providing the following advantages, presumably over the stainless steel wire suture standard (See CircumFix.com):
- Quick and easy application
- Bio-compatible polymer composition*
- Anatomically conforming
- Provides 3D stability
- Load distributing
- Radiolucent
- Unibody construction
- Reproducible
- Simple removal
- Sterile kit solution
These advantages, the manufacturer rhetorically argues, make VariTrax a more stable and potentially superior alternative technological advancement for sternal cerclage/closure compared to the current standard wire closure. But, the validity of these claims have not been substantiated at all using any proper evidentiary standard in clinical research and development — other than in a few hundred questionable observational VariTrax implanations performed by a few surgeons.
In fact, CircumFix itself advertises Varitrax as “The Future Standard in Sternal Closure” — implicitly acknowledging (appropriately so) that it is NOT the current standard. More importantly, the U.S. patent filing for VariTrax, on which the CircumFix CEO serves as inventor, explicitly stated that: “The standard method for reconstructing the surgically cut sternum is the placement of stainless steel wires circumferentially (cerclage) around the sternum segments and compressing together by twisting the wires tight to hold the surgically cut bone ends together approximating the pre-cut anatomical position of the sternum and chest wall. In most cases wire fixation has proven to be a successful and cost effective method of repairing the cut sternum with minimal reports of infection and non-union.” Thus, in VariTrax’s patent filing, CircumFix’s CEO is explicitly stating that sternal steel wire sutures, NOT the new VariTrax device made of PEEK, which is subject of the referenced patent, is the standard of care for circlage sternotomy closure.
To be clear, the new 510(k) cleared VariTrax medical device is NOT a standard of care in sternotomy closure because: 1) FDA’s 510(k) clearance label for any given “Indication for Use” does NOT automatically make a novel device, like VariTrax, a new standard, 2) VariTrax is made of the PEEK plastic material, which is not even remotely similar in composition to the long-established stainless steel wire suture standard used for sternotomy cerclage/closure, and 3) the VariTrax inventor and manufacturer, themselves, have both implicitly and explicitly admitted in their advertisements and public patent disclosures, that this 510(k) cleared medical device is NOT a current standard for sternotomy closure.
The problem exposed by the non-standard use of the new 510(k) cleared VariTrax medical device is more broadly important to public health in the medical device marketplace, on two counts:
- Patient Safety
- Surgeon and Medical Center Tort Liability
From a patient safety perspective, any time a new and non-standard medical product emerges into a clinical practice market space where a definitive standard of care (or predicte) pre-exists, it is critically important from a patient safety and efficacy perspective that the new product be demonstrated, at minimum, to be non-inferior to the existing and widely used standard. This approach to securing patient safety is especially important in high-risk clinical areas, as is the care of patients with cardiovascular disease requiring open heart surgery.
Demonstration of non-inferiority to an existing standard is even more important in the case of 510(k) cleared medical devices, whose clearance for market relies on a rather subjective and rhetorical demonstration of “substantial equivalency to a predicate” as assessed by an FDA officer or two — instead of proper clinically based and epidemiologically defensible evidentiary establishment of clinical non-inferiority to the pre-existing standard, or predicate. In other words, 510(k) clearance of new medical devices for marketing in the US by FDA, as is the case with VariTrax, does NOT necessarily provide a reasonable assurance of non-inferior safety and efficacy — ESPECIALLY, IN CLINICAL AREAS WHERE A WIDELY USED AND ESTABLISHED STANDARD OF CARE DEVICE ALREADY EXISTS.
From a practitioner liability perspective, any time a new and non-standard medical product is used by a clinician in any patient, there is a risk of liability. Specifically, because any adverse event related to the use of such new and non-standard medical devices may be judged to be the result of a “breach of standard”, which is a main principle governing adjudication of medical tort claims by the courts. Certainly, a 510(k) clearance in and of itself does not standardize a new medical device — especially in clinical areas where a long-standing and established standard pre-exists. To avoid liability for breaching an existing standards of care, clinicians interested in innovating in their areas of specialty, using new and non-standard medical products, typically seek patient informed consent for anecdotal used, or engage in IRB guided clinical trials.
Needless to say, if/when new and non-standard medical products are used in any patient, or series of patients, especially when such use is occurring electively in high-risk scenarios (e.g., open heart surgery), there is a legal duty, under both state and federal legal statutes, to obtain specific patient informed consent for such non-standard (and potentially “investigational”) treatment. The duty to inform patients of such new and non-standard uses, and their unknown safety and efficacy, rests squarely with the practitioner/medical center — and likely with the manufacturer of the non-standard medical product, even if the manufacturer has managed to obtain a 510(k) clearance from FDA to market its product. New and non-standard 510(k) cleared medical devices, though authorized to be marketed and sold in US interstate commerce, are not exempt from strict patient informed consent requirements under the law — the least of which those applicable to patients in high-risk clinical care scenarios like open heart surgery.
Certainly if any practitioners and medical centers elect to systematically use a new and non-standard medical product, including a 510(k) cleared medical device, in clinically high risk patients, and then to publish their clinical results in the public domain, there is a very clear ethical and legal duty to inform the human subject patients — and most rational and ethical clinicians and medical centers do so using guidance from their local Institutional Review Board (IRB).
As it pertains to the new and non-standard use of VariTrax in open heart surgery patients, the 510(k) clearance granted to this product by FDA allows the manufacturer to market and sell it in the US, but it does NOT obviate the legal requirement for full disclosure to and informed consent from patients for its clinical use — or the need for IRB involvement (even if it is to grant a waiver of consent), when a practitioner and medical center elect to systematically use/implant the device in the patients under their care. Also, neither standardization of a new and non-standard medical product, like VariTrax, nor the duty to enforce patient informed consent, fall within FDA’s direct jurisdiction — though FDA’s informed consent “guidance” is relatively clear to any rational practitioner, manufacturer or attorney, about the duty to inform patients. Rather, it is state/federal legal statutes governing medical malpractice liability, risk disclosure and patient informed consent requirements that impose a significant risk of liability to any practitioners or medical centers that use new and non-standard medical devices in the care of their patient(s), without informed consent.
A note of introspection regarding sternal closure/cerclage in open heart surgery: There is no question that the current standard stainless steel wire cerclage closure of sternotomy incisions has inefficiencies and deficits that could be improved upon. It is entirely possible that VariTrax may be that revolutionary novel device to provides an incremental (or monumental) improvement in clinical outcomes of sternotomy closure — as the CircumFix and Evonik manufacturers are hoping for. But my point is that we just don’t know yet! We don’t know if the safety and efficacy of the new and non-standard VariTrax 510(k) device is non-inferior to the existing standard. No amount of rhetorical hand-waving, aggressive legalistic posturing, or reliance on a 510(k) clearance/PMN from FDA, changes the fact that non-standard use of any new and unproven medical device in human subjects, WITHOUT informed consent from patients is actually illegal under state/federal statutes — with or without a 510(k) clearance from FDA.
In my opinion, any clinicians and medical centers that elect to use a new and non-standard medical device, like VariTrax, in the care of their already high risk patients, without, at minimum, full disclosure, patient inform consent and IRB guidance, are risking liability to themselves — and are in ethical and legal jeopardy. And any manufacturer of such a new and non-standard medical device that attempts to aggressively claim that the FDA’s 510(k) market clearance somehow standardizes their device or obviates the need for patient informed consent or IRB guidance for a new/non-standard use, is standing on extremely thin ice and is playing with fire — it does so at risk of peril to its own credibility and standing as a good faith actor in the U.S. healthcare marketplace.
Recently, my colleagues and I, at Northeastern University School of Law and Tufts University Medical Center’s Amy J. Reed Collaborative for Medical Device Safety, petitioned that FDA to re-review the VariTrax 510(k) clearance in light of our concerns about its new and non-standard use and composition in a high-risk patient population. One of our suggestion to FDA and the manufacturer is to assign an Investigational Device Exemption (IDE) to this device and initiate an IRB guided clinical trial to properly demonstrate its safety, efficacy and non-inferiority to the pre-existing standard stainless steel wire sutures used for sternal cerclage, which Varitrax also is claiming as one of its “substantial equivalency” predicates. By doing so, the manufacturer could work towards obtaining a PMA label for VariTrax as a new standard in sternal closure/cerclage in a properly designed, safe and well regulated framework. If VariTrax cerclage is truly non-inferior to stainless steel wire cerclage, obtaining a PMA should be relatively easy. In fact, having a PMA label, will not only establish VariTrax as a new definitvely reimbursable standard for sternotomy closure, it will also ensure that it’s use is safe, effective and, at minimum non-inferior (if not superior) to the current standard of care. Not to mention, a PMA label would pre-empt the manufacturer from product liability claims under Riegel v. Medtronic.
In my opinion, open heart surgery patients and cardiothoracic surgeons in the US deserve to know whether VariTrax is, at minimum, as safe and effective as the existing standard stainless steel wires sutures currently used as the standard for sternal cerclage closure in a vast majority of cases in the US and globally. After all sternotomy closure is not just a minor technical part of an open heart surgical procedures — it is as critically important to the health and successful recovery of the adult cardiac surgery patient, as is every other step in his/her care. But, at present, simply no one knows if clinical outcomes from non-standard use of VariTrax for sternotomy closure are truly non-inferior to standard sternal wires!
Therefore, it is a rational and defensible opinion to state that: any marketing (or legalistic) claim without clinical evidence of non-inferiority to an existing standard-of-care — or any anecdotal/observational clinical use of a new and non-standard medical device in human subjects — WITHOUT full disclosure and specific patient informed consent about the experimental, new and non-standard approach— is almost certainly ignorant, dishonest, misleading or potentially illegal/fraudulent behavior in the US healthcare marketplace, where patient safety and lives (not just dollars) are on the line.
Hooman Noorchashm MD, PhD
Research Professor of Law,
August 2025.
