ENDOCLEAR® Liberator® System Overview

This 30 minute video demonstrates the multiple functions of the endOclear® Liberator® Airway Maintenance System and how protocol driven use of this System results in:

• Safer Airway Management
 Improved patient outcomes
• Lower hospital costs



As several recent publications show, commonly used suction systems leave a significant amount of biofilm, mucus and secretions in the endotracheal tube.  The standard of care for maintenance of the artificial airway is not effective in maintaining patency1.

On the right (Figure: 1), is a cross-section of a typical endotracheal tube (ETT) after a few days of intubation and care with a standard Closed Suction System (CSS).  It has been shown that all endotracheal tubes accumulate biofilm and that the amount of accumulation is unpredictable and independent of time.2,5

Figure: 2 (right) shows a high-definition CT scan of an extubated ETT3.  In a related study, the average cross-sectional area reduction was about 25%1.  Again, this is after suction with CSS. This reduction in luminal volume results in higher imposed work of breathing equivalent to the next smaller ETT size in 48% and three sizes smaller in 10-15% of patients studied4.

Figure: 3 (right) provides a visual illustration pointing to the reason CSS does not address biofilm and retained sections and how figures 1 and 2 can be so prevalent. It is physically impossible for a suction catheter (14 French in an 8.0 ETT, for example) to remove adherent biofilm, mucus and secretions from the ETT wall.

Understandably, a typical response is:  “We know this but what can we do?  We don’t have a better tool.”  That is where it ends for most.

We asked the same question. However, we decided to try and address the problem.


“Although the internal lumen of an [endotracheal tube] ETT decreases substantially after a few days of intubation, due to formation of biofilm,84 suctioning should be performed only when clinically indicated in order to maintain the patency of the artificial airway used.85-87 Special consideration should be given to the potential complications associated with the procedure.”

– AARC Clinical Practice Guidelines, Endotracheal Suctioning of Mechanically Ventilated Patients With Artificial Airways 2010, Respir Care 2010;55(6):758 –764

– – –

The AARC, as part of their guidelines for proper endotracheal suctioning, affirms what has become common knowledge; the ETT lumen decreases “substantially” after a few days of intubation due to the formation of biofilm.

What we know…

• We know that “there is microbiological continuity between airway colonization, biofilm formation and VAP development”.4, 11
• We know that the use of closed suction systems (CSS) has had no impact on VAP rates, mortality and length of stay compared to open suction (OSS)15.
• We also know that leaving a closed suction catheter in place for a week or more has no impact on VAP, length of intubation or length of stay13.
• And we are beginning to learn about the connection between narrow endotracheal tubes, difficulty weaning and links to increased time on the ventilator and length of stay9, 10

Based on the available research, we decided to focus on the endotracheal tube. More specifically, the material that is allowed to collect and grow in it and what is not removed by our current standards of care.

The colonization of the endotracheal tube and its role in VAP was identified in 198911. Based on this research and the hypothesis that antimicrobial availability inside an ETT would prevent biofilm formation and subsequent inoculation of the lung, a silver lined ETT was introduced.

Addressing the growth of biofilm in the ETT was attempted with silver lined endotracheal tubes. “[ETTs] coated with silver deter the initial adherence of pathogens on the [ETT] surface. In laboratory 16, 17 and clinical trials silver-coated [ETT] have shown delayed biofilm formation. Yet, the efficacy of coated [ETTs] seems to weaken over time,18 as “colonized mucus builds up within the [ETT].”19  The antimicrobial silver had its greatest clinical impact during the first 10 days of intubation.20 However, there were no differences in durations of intubation, intensive care unit stay, and hospital stay which led to a “Generally not recommended” conclusion for use as a VAP mitigation technique.15 It has been hypothesized that the failure of the silver lined ETT to make a significant clinical difference was due to the build-up of secretions in the ETT which protected the bacteria from the silver.21

The NASCENT trial and use of silver lined ETTs (through which much of the above referenced data was collected) were on the right track! The obstacle the silver lined ETT could not overcome, however, was mucus build up that was not being removed (by the standard of care suction).

Artificial airway patency and proper clearing are not being addressed by the current standards of care. The replacement of OSS by CSS (keeping a closed circuit) made no difference in mortality, length of stay or VAP rates. Leaving CSS in place for 7 days or more made no difference either – which is interesting because of the concerns of what would grow on the CSS catheter and how that might negatively impact outcomes. Lastly, the introduction silver-coated endotracheal tubes made no difference (although it showed promise).

All of the data (with regard to addressing time on the ventilator, length of stay, mortality and VAP as it relates to patency) seems to point to what is in the ETT. More specifically, the data points to the material that is allowed to collect and grow in the ETT and what is not removed by our current standards of care.

We have re-imagined a new standard of care that attempts to address the problem directly, efficiently and safely.


BEFORE (Figure 1)

The above Bioluminescense Image shows a distribution and concentrations of bacteria in an ETT.

Blue = low concentration
Yellow/Green = medium concentration
Red = High concentration


AFTER (Figure 2)

The above Bioluminescence image shows the effectiveness of the endOclear® Restore device in removing secretions and bacteria from the ETT in Fig. 1.



We have used closed suction for 30 years without any problems. Why use the endOclear® Liberator™ System?
Closed suction alone is inadequate to clear retained and obstructing secretions that lead to increased airway resistance and work of breathing.1,2,3,4,8,11  Also, suction allows colonization of the endotracheal tube (ETT) with VAP causing microorganisms and permits maturation of infectious biofilm that is consistently found to be linked with VAP occurrence. The endOclear® Liberator™ System has a patented wiper that removes material from the ETT that would otherwise be left behind, reducing airway resistance and work of breathing.6,7

We use heated wire/active humidification instead of HMEs in our ventilator circuits to decrease obstruction. Isn’t that enough?
While it is widely held that heated wire/active humidification circuits result in less total or emergent obstruction of the artificial airway than HMEs, the evidence shows that these circuits have the same issues of secretion accumulation with increased resistance and work of breathing and also colonization and biofilm formation within the ETT.

My CS catheter is quite stiff and easy to push in quickly. Won’t a softer silicone catheter be harder to advance inside the ETT? Yes. On average it will take a few extra “pushes” to get into position. However, silicone is softer and therefore safer to tracheal mucosa if suctioning is performed beyond the end of the ETT. Also, unlike commonly used suction systems that require 4 or more passes, we have designed a system that can clear an ETT with 2 passes for most patients. In some cases, the tube can be cleared without using suction at all and be done in one pass.

Your device only goes out the end of the ETT a few centimeters. What about the patient needing deep suctioning?
The AARC clinical practice guidelines recommend against deep suctioning.12  If the clinician really believes a patient requires deep suctioning it can be done using the endOclear® Liberator® System accessory adaptor and a long, open suction catheter. However that clinical assessment may more appropriately require a bronchoscopy, which may also be performed using the accessory adaptor.

I leave my CSS in place for up to a week. Why is your device approved for only 72 hours?
The endOclear® Liberator® System is a complex device with multiple functions, and has been designed for safe and reliable functioning for up to 72 hours. It has been reported that commonly used CS devices that do not clear the ETT and allow bacteria and biofilm to accumulate can be used up to 7 days without impacting length of stay, infection rates or mortality.13  A likely reason is that colonization of the catheter is irrelevant compared to what is going on in the ETT and therefore does not contribute significantly to the bacterial or fungal problem. In contrast, the endOclear® Liberator® System is designed to disrupt the growth and accumulation of harmful material in the ETT. Therefore we don’t want colonization and biofilm formation within the manifold and catheter module over time to affect a patient’s infection risk.

What if a patient has bloody or really thick secretions that are hard to remove completely even with the endOclear® Liberator™ System?
The clinician should use the endOclear® Restore™ single use catheter with the endOclear® Liberator® System Accessory Adaptor to effectively remove exceptionally tenacious debris and then return to ETT maintenance with the endOclear® Liberator® System. The endOclear® Restore™ may be used in any intubated patient, not only those on the endOclear® Liberator® System device.

What if the secretions are so thick and voluminous that the cleaning chamber becomes fouled and the catheter cannot be cleaned?
First be certain the stopcock is closed to completely isolate the cleaning chamber. Then use higher suction to aspirate and irrigate the cleaning chamber. If unsuccessful, the catheter module can be disconnected from the manifold and the catheter cleaned with a sterile 4×4. Alternatively the closed suction catheter module can be replaced, either by itself or as part of a complete device change out.

What if I need to do an FOB or a BAL?
The optional endOclear® Liberator® System accessory adaptor is an FOB/BAL/instrumentation adaptor that maintains the closed ventilator circuit during the procedure and accepts devices 3-7 mm in diameter.

How many times a day should the endOclear® Liberator® System be used?
The recommendation is every six hours as that schedule has been shown to markedly decrease bacterial and fungal colonization and biofilm formation.14  Of course, it may also be used as needed based on patient status.

Why routinely do a suction pass first?
As a catheter advances down the ETT, it can act as a “bulldozer” and push secretions distally. The first pass using suction clears a path for the catheter and sucks up secretions that collect at the catheter tip. However, if a patient requires high ventilatory pressures and PEEP, the clinician may choose to avoid suction entirely and only use the wiper function.

Should we use endOclear® Liberator® System for patients expected to be extubated within 24 hours?
We think so, yes. Secretion buildup can occur quickly and is unpredictable.4 Having a clear airway may be the difference between a normal extubation and an extended stay in the ICU. A patient who “should” pass their spontaneous breathing trial may not do so if unpredicted secretions accumulate and increase airway resistance and work of breathing.

Does using the endOclear® Restore™ or endOclear® Liberator® System decrease VAP?
Unlike other systems that claim to be part of a “VAP Solution”, we do not make any assertion that use of the endOclear® Restore™ or endOclear® Liberator® System will decrease VAP. It should be noted that commonly used Closed Suction Systems have been shown to not decrease VAP, length of stay or mortality compared to Open Suction Systems. VAP is a complicated matter and has evolved through many different criteria for diagnosis, with some hospitals reporting zero VAP although their ICU antibiotic use has remained the same or even increased. To show that one intervention by itself decreases VAP is extremely difficult to do and something that we do not claim. What we can say is that cleaning the ETT better can result in decreased length of intubation, decreased ICU length of stay, decreased length of hospital stay, and decreased direct patient costs.5,6,7 Research suggests that decreasing airway resistance and work of breathing improves the chance of weaning successfully and sooner.6,9,10

If we use the endOclear® Liberator® System in all of our intubated patients, why do we need to stock the endOclear® Restore™?
The 2 devices are elements of an airway maintenance system, with the endOclear® Liberator® System addressing routine clearing and prevention of obstruction (maintenance) and the endOclear® Restore™ used for acute or emergent problems in a (hopefully) small number of patients. (See FAQ 6)

Isn’t the endOclear® Liberator™ System just a fancy and expensive suction catheter?
The endOclear® Liberator® System is artificial airway maintenance re-imagined. It is an elegant solution to a problem that has been largely ignored, is efficient, safer and more versatile than any other closed suction system available.  So, yes it is “fancy” and more expensive than commonly used suction catheters, but the endOclear® Liberator® System is not just a suction catheter – it is part of an artificial airway maintenance system that can result in significant benefits to the patient, care giver and hospital.

Who can use the endOclear® Liberator® System or the endOclear® Restore™?
The primary users are nurses and respiratory therapists. All users must be in-serviced and signed off on satisfactory completion before using either device clinically. The company program includes developing “super users” at each institution to train new hires, department transfers, etc.

What if the endOclear® Liberator® System malfunctions?
If the manifold is clean the modular closed suction catheter may be replaced (replacement catheters sold separately). If the manifold is soiled, the entire system should be replaced.

Is the endOclear® Liberator® System contra-indicated for any patients (other than size of ETT), such as those with high pressure ventilatory requirements?
One of the significant features of the endOclear® Liberator® System is that the device can be used to clear ETT’s without suction.  In addition, the manifold can be completely isolated from the closed suction catheter module so that a loss of ventilatory pressure/PEEP is never necessary even when performing a FOB or BAL procedure using the optional endOclear® Liberator® System accessory adaptor. There are no contraindications for use other than size of the ETT, and other standard cautions as noted on the labeling.

Can the endOclear® Liberator® System be used in ETTs less than 7.0?
The endOclear® Liberator® System is designed to be used in ETT’s from 7.0 – 8.5.  Smaller (and larger) sizes will be available in the near future.

Do we need to use 15 cc rather than 5 cc saline bullets?
15 cc bullets are recommended. In this instance, more is better due to the likelihood that more material will be retrieved than commonly used catheters. Complete isolation of the manifold allows as much saline as necessary to clean the catheter, as there can be no leak into the ETT.

Don’t see your question here?
Please e-mail Gary Saur, ENDOCLEAR LLC Director of Clinical Affairs, at: gsaur@endoclearllc.com


At ENDOCLEAR LLC, we are driven to continuously explore and develop new technology for improving patient care and reducing hospital cost. Developing and acquiring new technologies has enabled us to create innovative and helpful product solutions.

Various existing or contemplated features of the ENDOCLEAR® technology are covered by one or more U.S. patents, with additional U.S. and international patents pending. In accordance with Section 287(a) of Title 35 of the United States Code, see the lists below to find U.S. patents associated with particular products. Each list of patents by product name applies to all package counts, unless stated differently. Items listed below may be sold individually or as part of a combination product.  This list was last revised on January 31, 2017. Other patents issuing after the date of the last revision may also cover the products listed below but may not be included until this list is next revised.

Any inquiries should be directed to ENDOCLEAR LLC at 855.887.8366

endOclear® Liberator® System
US 7,051,737 (exclusively licensed from National Institutes of Health)
US 10,016,575
US 10,004,863
US 9,907,624

endOclear® Restore™ Device
US 8,381,345
US 8,382,908
US 8,458,844
US 8,468,637
US 8,601,633
US 9,962,233

endOclear® Biofilm Collection Adaptor
US 9,445,714

Additional ENDOCLEAR LLC Patents
US 8,157,919
US 8,534,287
US 9,095,286
US 9,386,907
US 9,332,891
US 9,398,837
US 9,579,012
US 9,855,111


1 Pinciroli, R., Mietto, C., Berra, L., 2013, Use of High-Definition Computed Tomography to Assess Endotracheal Tube Luminal Narrowing after Mechanical Ventilation, Anesthesiology 2013

2 Danin, P-E, et. al., 2015, Description and Microbiology of Endotracheal Tube Biofilm in Mechanically Ventilated Subjects, Respiratory Care 2015; 60(1):21-29

3 Gil-Perotin, S., 2012, Implications of endotracheal tube biofilm in ventilator-associated pneumonia response: a state of concept , Critical Care 16:R93 doi: 10.1186/cc11357

4 Wilson, A., Gray, D., Karakiozis, J., Thomas, J., 2012, Advanced endotracheal tube biofilm stage, not duration of intubation, is related to pneumonia, Journal of Trauma and Acute Care Surgery, April 2012 – Volume 72 – Issue 4 – p 916–923

5 Schofield, L., 2013, The use of Endoclear Catheter Device to Improve Ventilator Weaning, Chest 2013 Annual Meeting (Chicago, IL) October 30-31, 2013

6 Schofield, L., Shorr, A., et. al., 2014, The Impact of a Unique Airway Clearance System on Airway Mechanics in Ventilated Patients, SCCM Annual Congress (San Francisco, CA) January 9-13, 2014

7 Comparison of Two Endotracheal Tube Cleaning Devices in Reducing Airway Resistance for the Mechanically Ventilated Patient, Schofield, L, et. al., AARC Congress (Tampa, FL) November 9-11, 2015

8 Shah, C., Kollef, MH.., 2004, Endotracheal tube intraluminal volume loss among mechanically ventilated patients Crit Care Med, Jan;32(1):120-5

9 Valentini I, Tonveronachi E, Gregoretti C, Mega C, Fasano L, Pisani L, Nava S. Different tracheotomy tube diameters influence diaphragmatic effort and indices of weanability in difficult to wean patients. Respir Care. 2012;57(12):2012-2018.
10 Epstein SK. “Narrow” thinking about difficult weaning: don’t forget the endotracheal tube. Respir Care 2012;57(12):2130-2132.

11 Inglis, T., Millar, M., Jones, G., Robinson, D., 1989, Tracheal Tube Biofilm as a Source of Bacterial Colonization of the Lung, Journal of Clinical Microbiology, Vol. 27, No. 9, p. 2014-2018

12 AARC, Endotracheal Suctioning of Mechanically Ventilated Patients With Artificial Airways 2010, Respir Care 2010;55(6):758 –764

13 Kollef MH, Prentice D, Shapiro SD, Fraser VJ, Silver P, Trovillion E, Weilitz P, Von Harz B, St. John R. Mechanical ventilation with or without daily changes of in-line suction catheters, AM J RESPIR CRIT CARE MED 1997;156:466–472

14 Berra, 2012, A clinical assessment of the Mucus Shaver: a device to keep the endotracheal tube free from secretions, Crit Care Med Jan;40(1):119-24

15 Michael Klompas, Richard Branson, Eric C. Eichenwald, Linda R. Greene, Michael D. Howell, Grace Lee, Shelley S. Magill, Lisa L. Maragakis, Gregory P. Priebe, Kathleen Speck, Deborah S. Yokoe and Sean M. Berenholtz (2014). Strategies to Prevent Ventilator-Associated Pneumonia in Acute Care Hospitals: 2014 Update. Infection Control & Hospital Epidemiology, 35, pp 915-936 doi:10.1086/527363

16 Olson ME, Harmon BG, Kollef MH. Silver-coated endotracheal tubes associated with reduced bacterial burden in the lungs of mechanically ventilated dogs. Chest. 2002; 121: 863–70

17 Berra L, De Marchi L, Yu ZX, Laquerriere P, Baccarelli A, Kolobow T. Endotracheal tubes coated with antiseptics decrease bacterial colonization of the ventilator circuits, lungs, and endotracheal tube. Anesthesiology. 2004; 100: 1446–56

18 Berra L, Curto F, Li Bassi G, Laquerriere P, Baccarelli A, Kolobow T. Antibacterial-coated tracheal tubes cleaned with the Mucus Shaver : a novel method to retain long-term bactericidal activity of coated tracheal tubes. Intensive Care Med. 2006; 32: 888–93

19 Aguilera Xiol E, Li Bassi G, Wyncoll D, Ntoumenopoulos G, Fernandez-Barat L, Marti J. D., Comaru T, De Rosa F, Rigol M, Rinaudo M, Ferrer M, Torres A. Tracheal tube biofilm removal through a novel closed-suctioning system: an experimental study, British Journal of Anaesthesia, 115 (5): 775–83 (2015)

20 Kollef MH, Afessa B, Anzueto A, et al. Silver-Coated Endotracheal Tubes and Incidence of Ventilator-Associated Pneumonia: The NASCENT Randomized Trial. JAMA. 2008;300(7):805-813. doi:10.1001/jama.300.7.805.

21 Clinical Trial NCT02120001 – Efficacy Study on Silver-coated ETT Cleaned With a Novel Device – Completed

22 Mietto C., et. al., Removal of Endotracheal Tube Obstruction With a Secretion Clearance Device, Respir Care 2014;59(9):e122–e126

23 Pinciroli R., et. al., Endotracheal Tubes Cleaned With a Novel Mechanism for Secretion
Removal: A Randomized Controlled Clinical Study, Respir Care 2016;61(11):1431–1439.


Endoclear LLC was founded by Dr. Brad Vazales, a cardiovascular surgeon from Petoskey, Michigan with the following goals in mind:

1. Reduce Hospital Acquired Infections (HAI) and specifically target Ventilator Associated Pneumonia (VAP)

2. Improve the efficiency and efficacy of endotracheal tube (ETT) cleaning

3. Reduce the number of days on a ventilator to absolute minimum

In his practice, Dr. Vazales noted that most ventilator patients who experienced difficulty weaning and subsequently underwent tracheostomy improved dramatically within 24 hours, and often could be weaned very quickly afterward. Curious to understand why, Dr. Vazales decided to examine the ETT he removed from patients undergoing tracheostomy. He observed two things:

1. Even though patients’ ETT were regularly suctioned, almost all ETT removed at the time of tracheostomy were significantly occluded by a thick biofilm. The reduction in diameter of the ETT increased airway resistance and caused significant increases in patients’ work of breathing (WOB)

2. Biofilm in the ETT was comprised of the same organisms that colonized the oropharynx of intubated patients and could be contributing to VAP.

Dr. Vazales hypothesized that if harmful biofilm could be cost effectively removed from patients’ ETT with the same (or better) safety profile as blind suctioning, then patients, hospitals, and society could benefit in several ways:

1. Patients with reduced WOB would require less sedation, recover faster, and wean faster from the ventilator (reduction of ventilator ICU days saves US hospitals an average of $6,000/day; reducing the financial burden to patients, hospitals, and society)

2. Patients that wean faster would not require a tracheostomy (reducing both morbidity, mortality) and could have less opportunity for VAP (VAP occurs most commonly in patients beyond 48-72 hours of intubation and elimination of biofilm on the inside of the ETT could possibly reduce VAP as it is comprised of the same organisms found in teeth plaque and the oropharynx; the very reason teeth brushing of ventilator patients is now the standard of care in ICUs worldwide).


A team of clinicians and developers addressing unmet and urgent needs of patients, caregivers and hospitals by re-imagining the future of artificial airway maintenance and engineering a new standard of care.


2400 Camino Ramon, Suite 106
San Ramon, California 94583
Map our location »


T 855.887.8366
F 925.237.9233
E info@endoclearllc.com