A Camera Inside the Scope: What Borescope Inspections Reveal About “Clean” Endoscopes

For years, the argument over contaminated scopes was hard to picture. A hospital would insist its duodenoscope had been cleaned by the book; a patient who got a superbug infection afterward had no way to see inside the device to show otherwise. That changed when infection-prevention researchers started using a borescope — the same kind of tiny inspection camera a mechanic snakes into an engine — to look inside reprocessed endoscopes. What the camera found, again and again, was not a spotless channel. It was scratches, shredded lining, gritty debris, and beads of leftover fluid inside scopes that had already been cleaned and marked ready for the next patient. This article explains what those studies actually documented, why the national processing standard now tells facilities to look inside, and why that record can matter when someone gets sick.

What Is a Borescope, and Why Does It Take a Camera to Inspect a Scope?

A borescope is a very thin, flexible camera on a cable, thin enough to pass down the working channel that runs the length of an endoscope. That channel is the problem it solves. A reusable duodenoscope or colonoscope has a long, narrow internal lumen that a technician can never see into by eye — it is too small, too long, and too dark. Standard reprocessing relies on brushing, flushing with detergent, and high-level disinfection, and then on a visual once-over of the parts a person can actually see. The inside of the channel is a blind spot. A borescope removes that blind spot by putting an eye where the bacteria live.

Why does the inside matter so much? Because that is exactly where a scope’s design makes cleaning hard. As we explain in our breakdown of the duodenoscope elevator-mechanism design defect, the crevices and moving parts at the tip — and the channel behind them — are the places a brush cannot reliably reach. If cleaning fails there, no amount of scrubbing on the outside fixes it. A borescope is the tool that shows whether it failed.

What Did the Borescope Studies Actually Find?

The findings are hard to argue with because they are photographs. In a study published in Gastrointestinal Endoscopy in 2018, researchers at UCLA inspected 59 endoscopes across 97 inspections using a prototype borescope after the devices had gone through full reprocessing. They found scratches in 86% of the devices and channel shredding — the inner lining peeling or fraying — in 59%. Loose debris inside the channel turned up in 23% of the inspections. These were not scopes flagged as broken; they were the working instruments a busy endoscopy unit was using on patients. The authors concluded that video inspection of the channel “may be useful to audit reprocessing performance and to identify damaged endoscopes.”

Other research teams have found the same pattern with other scope types. In studies led by infection-prevention researcher Cori Ofstead and colleagues, published in the American Journal of Infection Control, inspection of fully reprocessed flexible endoscopes routinely turned up visible irregularities — discoloration, residue, scratches, and debris — along with retained fluid inside a large share of the devices. In one multisite look at drying, retained moisture was detected in roughly half of the endoscopes examined, and retained fluid was associated with higher contamination readings. In a separate examination of reprocessed ureteroscopes, every scope inspected showed some visible irregularity, and laboratory testing detected residual protein on all of them. Damage and leftover moisture are not cosmetic problems: scratches and grooves give bacteria a foothold, and standing fluid is what lets them multiply.

Why Damage and Debris Turn Into Infection

A brand-new channel is smooth, so disinfectant can wash across it and reach everything. Once the lining is scratched or shredded, that smooth surface is gone. Bacteria settle into the grooves and form biofilm, a slick protective layer that shields them from disinfectant. On the next patient, the scope can deposit whatever survived directly into the body. This is the same mechanism behind the FDA’s own finding that roughly 1 in 20 properly reprocessed duodenoscopes still tested positive for contamination. The borescope studies show one reason why: a meaningful fraction of scopes in daily use are physically damaged inside in ways that make full disinfection unlikely.

Damage also accumulates. A channel does not shred all at once; it wears with each use, brush, and repair. A scope that borescoped clean a year ago may not today. That is precisely why a single inspection is not enough, and why the standard treats inspection as an ongoing duty rather than a one-time check.

The Standard Now Says: Look Inside

These studies did not stay in the journals. The national voluntary standard for endoscope processing — ANSI/AAMI ST91:2021, the document U.S. sterile-processing departments follow — was updated to recommend that facilities visually inspect endoscopes and periodically use a borescope to examine the internal channels, with the frequency set by the facility. The same standard calls for lighted magnification when inspecting the scope’s distal tip, and it directs that high-risk endoscopes — duodenoscopes, bronchoscopes, ureteroscopes, cystoscopes, and similar devices — be checked with cleaning-verification tests after every use. The FDA and CDC likewise recommend careful visual inspection with magnification as part of reprocessing.

That evolution matters beyond the cleaning room. When a recognized professional standard tells facilities to inspect for internal damage, a facility’s decision not to inspect — or to keep using a scope that inspection flagged as damaged — becomes a fair question in a lawsuit. It is one thing to argue a hidden defect could not have been known; it is another when the tool to find it was recommended and available. This is the reprocessing-side companion to the product-liability argument we lay out in our discussion of single-use duodenoscopes as the safer design the FDA recommended: when a safer option or a safety check is on the table and goes unused, that choice is part of the story.

How This Becomes Evidence in a Scope-Infection Case

A scope-infection case is built one record at a time, and the borescope story adds a category of records worth chasing. Beyond the reprocessing logs and device-tracking data we describe in our guide to requesting and preserving hospital records after a scope infection, a thorough review asks: Did the facility ever borescope this scope? What did the inspection show? How many times had this specific device been sent out for repair, and why? Was a scope with documented internal damage kept in the rotation anyway? Repair invoices, inspection logs, and device-maintenance histories can answer those questions.

None of that decides a case by itself. It fits into the same two-track framework as every scope claim — hospital reprocessing negligence on one side and product liability against the manufacturer on the other — and it has to line up with the clinical facts: the organism cultured from the patient, the timeline in the chart, and whether other patients at the same facility grew the same bug in the same window. What the borescope evidence adds is a way to test the hospital’s central claim. “The scope was clean” is a much weaker statement when the facility never looked inside — or looked, saw damage, and used it anyway.

A Trial Lawyer’s Read

“For a long time the defense in these cases was simple: we followed the cleaning steps, so the scope was clean. The borescope research takes the mystery out of it,” says Alex Alvarez, Managing Partner of The Alvarez Law Firm and a Board Certified Civil Trial Lawyer. “When a study photographs shredded channels and debris in the majority of scopes a hospital is actually using, ‘we followed the steps’ stops being the end of the conversation. Now I want the inspection log and the repair history for that exact device, by serial number. If they never looked inside, that’s a choice. If they looked and kept using it, that’s a bigger one.”

The medical records tell the other half. “The device history and the patient’s chart have to meet in the middle,” notes Herb Borroto, M.D., J.D., the firm’s Medical-Legal Expert, who holds both a medical degree and a law degree. “I’m matching the organism and its resistance pattern, the date the culture was drawn, and the procedure date against what the equipment records show. If a scope had documented internal damage and a patient then grew a resistant organism that other patients in that unit also grew, the pieces start to fit. My job is to read whether the documents support that connection or rule it out — and inspection findings are one of the pieces I look for.”

What to Do Now

If you or a loved one developed a serious infection — sepsis, a bloodstream infection, or a drug-resistant organism — after an ERCP, colonoscopy, bronchoscopy, or another procedure using a reusable scope, the equipment records and the culture results are the proof, and they do not last forever. Inspection logs, repair histories, reprocessing records, and device-tracking data are archived or discarded on routine retention schedules, and knowing what to ask for — including whether the scope was ever borescoped — can be the difference between a preserved case and a lost one. Our guide to the signs an infection was caused by a scope can help you understand whether your situation fits the pattern.

A short, no-obligation review can tell you whether the facts warrant pulling those records and whether a filing deadline may be approaching. We represent patients nationwide. Free case review. No Fees Unless We Recover Money for You.

Frequently Asked Questions

Can a reprocessed endoscope still be contaminated or damaged after it is cleaned?

Yes. Multiple peer-reviewed studies that used a borescope — a tiny camera on a flexible cable — to look inside fully reprocessed endoscopes found problems in the great majority of them. One study of 59 endoscopes reported scratches in 86% and channel shredding in 59%, and other researchers found retained fluid, debris, and residue inside scopes that had already been cleaned, disinfected, or sterilized and were considered ready for the next patient. Damage and moisture matter because scratches and grooves give bacteria a place to hide and moisture lets them grow.

What is a borescope and why do hospitals use it on endoscopes?

A borescope is a very thin inspection camera on a flexible cable that can be threaded through the long internal channel of an endoscope so staff can actually see inside it. Because a reusable scope’s working channel is too narrow and too long to inspect by eye, a borescope is the only practical way to check for internal scratches, debris, fluid, or damage after cleaning. Professional standards now recommend periodic borescope inspection precisely because a scope can look clean on the outside while hiding contamination or damage inside.

Do professional standards or the FDA recommend borescope inspection?

The national voluntary standard for endoscope processing, ANSI/AAMI ST91:2021, recommends visual inspection of endoscopes including the periodic use of a borescope to examine internal channels, and it calls for lighted magnification of the scope’s distal end. It also directs that high-risk endoscopes — duodenoscopes, bronchoscopes, ureteroscopes, cystoscopes, and similar devices — be checked with cleaning-verification tests after each use. The FDA and CDC likewise recommend careful visual inspection with magnification as part of reprocessing.

Can inspection and repair records help a scope infection lawsuit?

They can be important evidence. In a scope-infection case, a lawyer looks at whether the facility inspected the scope, what any borescope or visual inspection showed, how often the device had been repaired, and whether a damaged scope stayed in service. Those records sit alongside reprocessing logs, device-tracking records, and culture results. Whether any individual has a claim depends on the specific facts, and these records are archived or discarded on routine retention schedules — so identifying and preserving them early can matter.

Sources

• Thaker AM, Kim S, Sedarat A, Watson RR, Muthusamy VR. “Inspection of endoscope instrument channels after reprocessing using a prototype borescope.” Gastrointestinal Endoscopy, 2018;88(4):612–619 (scratches in 86% and channel shredding in 59% of 59 reprocessed endoscopes; intrachannel debris in 23% of inspections). pubmed.ncbi.nlm.nih.gov
• Ofstead CL, et al. “Residual moisture and waterborne pathogens inside flexible endoscopes: Evidence from a multisite study of endoscope drying effectiveness.” American Journal of Infection Control, 2018 (retained moisture and contamination detected inside fully reprocessed endoscopes). ajicjournal.org
• Ofstead CL, et al. “Effectiveness of sterilization for flexible ureteroscopes: A real-world study.” American Journal of Infection Control (visible irregularities and residual protein detected on reprocessed ureteroscopes). ncbi.nlm.nih.gov
• Association for the Advancement of Medical Instrumentation — ANSI/AAMI ST91:2021, “Flexible and semi-rigid endoscope processing in health care facilities” (recommends borescope inspection of internal channels, lighted magnification, and cleaning-verification testing of high-risk endoscopes after each use). webstore.ansi.org
• U.S. Food & Drug Administration — “Infections Associated with Reprocessed Duodenoscopes” (post-market sampling and contamination-after-reprocessing findings for reusable duodenoscopes). fda.gov

This article is for general informational purposes only and is not legal or medical advice. It summarizes published research, professional standards, and regulatory communications as of the publication date; medical guidance and standards can change, and this article does not describe the outcome of any client’s case. Study findings about endoscopes in general, and the existence of an inspection standard, are evidence to be evaluated, not proof of any individual’s claim. Nothing here creates an attorney-client relationship, and no result is promised or implied. Past results do not guarantee future outcomes. Deadlines and legal standards vary by state and by the facts of each case. If you believe you may have a claim, consult a licensed attorney promptly.