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`Toxic Posterior Segment Syndrome Due to Reuse of Cannulated Tools - Retina Today
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`July/ August 2009 I Retina In The Ase
`Toxic Posterior Segment Syndrome Due to Reuse of Cannulated
`Tools
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`Similarities to TASS should be considered.
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`Steve Charles, MD
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`One of the main misconceptions regarding ambulatory surgery centers (ASCs) that I encounter around the
`country and, indeed, around the world, is that surgeries in ASCs are performed "on the cheap." Part of that
`misconception involves having to reuse disposable equipment in order to be profitable. I studied the direct
`case overhead costs at the Spectra Eye Institute and found that almost 70% of the overhead was due to
`personnel and less than 20% due to disposable instrumentation. In the following article, Steve Charles, MD,
`eloquently points out that reusing disposable equipment can be dangerous.
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`Even from a business standpoint, focusing on surgical equipment to cut costs does not make sense. If70% of
`my overhead is personnel, it makes more business sense for me to focus my efforts on proper staff task
`assignment for the proper skill (and salary) level. For instance, is a skilled and expensive nurse necessary to
`position a patient or push a bed? Or can this task be assigned to less skilled (and less expensive) staff?
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`Personnel task management is a key to achieving ASC financial success by reducing overhead. Unfortunately,
`the ASC physician owners rarely give it much thought. Instead, we tend to focus on the 20% cost of
`disposable equipment. The bottom line is that reusing disposable equipment not only compromises patient
`care, but does not make business sense. -Pravin U. Dugel, MD
`Toxic anterior segment syndrome (TASS) is an acute, postoperative, noninfectious inflammation that
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`occurs after cataract surgery, corneal transplantation, and glaucoma surgery. The incidence has
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`been estimated at 0.1 % to 2.0%; it seems to be increasing worldwide and occurs in clusters
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`(institutional outbreaks). It is the author's contention that a similar phenomenon can occur after
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`vitreoretinal surgery due to reuse of tools with lumens, which includes all scissors and forceps.
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`FIBRIN SYNDROME
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`TASS presents within a few hours after surgery with blurred vision (all patients), severe limbus-to(cid:173)
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`limbus corneal edema (surgical trauma produces localized edema), 4+ flare, hypopyon, fibrin,
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`minimal conjunctiva! or episcleral hyperemia, and minimal to no pain (75% to 80% of patients with
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`endophthalmitis have pain).
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`Toxic Posterior Segment Syndrome Due to Reuse of cannulated Tools - Retina Today
`1/6/22, 6:09 PM
`Vitreoretinal surgeons have reported a similar com~ ication for decades but described it as fibrin
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`syndrome or sterile endophthalmitis.
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`Fibrin syndrome has been reported after extensive cryopexy, cyclodestructive procedures, intense
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`endolaser to prior detached retina with residual subretinal fluid, use of poor quality silicone oil,
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`heavy silicone oil, iris manipulation or iris retractors especially in uveitis cases, retained lens
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`material, implanting IOLs in uveitis cases, and in proliferative diabetic retinopathy cases with florid
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`neovascularization.
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`Sterile endophthalmitis has been reported after injecting intravitreal triamcinolone acetonide
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`(Kena log, Bristol-Myers Squibb), hyaluronidase (Vitrase, lsta Pharmaceuticals, Inc.), and selected
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`pharmacologic agents.
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`Long term complications of TASS include: glaucoma due to peripheral anterior synechiae and
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`trabecular meshwork damage, chronic inflammation, cystoid macular edem, corneal endothelial
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`damage, iris damage, fixed pupil, and iris transillumination defects.
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`CAUSES OF TOXIC ANTERIOR AND POSTERIOR SEGMENT SYNDROMES
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`Causes of TASS include surgical issues, drugs and devices, and process issues.
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`Surgical issues in TASS include: retained lens cortex, iris trauma, iris retractors,
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`endocyclophotocoagulation, and ointment in the anterior chamber.
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`Device and drug factors in TASS include: Poor quality infusion solutions, intraocular lidocaine,
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`intraocular epinephrine (pH, dose, preservative, stabilizing agents: bisulphites or metabisulphites),
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`intraocular antibiotics (pH, concentration, dose), intraocular triamcinolone acetonide (active drug
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`and preservative), and poor quality viscoelastics. Many of these issues are also applicable to
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`vitrPnrPtin~I c.11n:rprv
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`Novartis Exhibit 2292.002
`Regeneron v. Novartis, IPR2021-00816
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`

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`1/6/22, 6:09 PM
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`Toxic Posterior Segment Syndrome Due to Reuse of Cannulated Tools - Retina Today
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`Process issues that have been proven in TASS include contamination within steam sterilizer (filters,
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`water chambers, and the inside of autoclave), denatured viscoelastics from resterilized cannulas,
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`bacterial endotoxins from gram negative bacteria killed when cannulas are autoclaved,
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`contamination of ultrasonic cleaner, water baths with enzymes or detergents, endotoxins from tap
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`water, detergent or chemical residue on instruments, and incomplete cleaning of reusable cannulas.
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`All of these process issues are also applicable to vitreoretinal surgery. It is important to point out
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`that all scissors and forceps have lumens to permit axial movement of the actuator rod relative to
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`the outer hollow shaft. These lumens are extremely difficult to clean and rinse, especially with 23-
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`and 25-guage instruments. The intraocular pressure is greater than atmospheric pressure, which
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`forces protein and other biomaterials into the lumen.
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`Benefits of Disposable Instrumentation
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`Small diameter 25- and 23-gauge scissors and forceps are easily damaged during cleaning and
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`sterilization. Disposable scissors and forceps provide optimal gripping and cutting performance
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`from beginning to end of every case. Disposable tools eliminate the risk of contamination from
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`transmissible spongiform encephalopathy/bovine spongiform encephalopathy/prions, bioburden,
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`hepatitis, HIV/AIDS, denatured proteins, and bacterial endotoxins. Disposable tools reduce per case
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`cost because of elimination of cleanup, sterilization, packaging, storage, backup, and inventory costs
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`including labor and materials.
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`In summary, fibrin syndrome after vitreoretinal surgery may be due to process issues associated
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`with reuse of scissors, forceps, and cannulas: ie, toxic posterior segment syndrome.
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`Steve Charles, MD, is Founder of the Charles Retina Institute in Memphis, TN, and is a Clinical Professor
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`in the Department of Ophthalmology at the University of Tennessee College of Medicine. He is a Retina
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`Today Editorial Board member and states that he is a consultant for Alcon Laboratories, Inc. Dr.
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`Charles can be reached via e-mail: scharles@att.com.
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`Pravin U. Dugel, MD, is Managing Partner of Retinal Consultants of Arizona and Founding Member of
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`the Spectra Eye Institute in Sun City, AZ. He is a Retina Today Editorial Board member. He can be
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`reached at pdugel@gmail.com.
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`July/August 2009
`MORE FROM THIS ISSUE ➔
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`https://retinatoclay.com/articles/2009-july-aug/0709 _ 05-php
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`3/6
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`Novartis Exhibit 2292.003
`Regeneron v. Novartis, IPR2021-00816
`
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