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Welcome the Poiesis Medical LLC clinical research page. Here you can find a library of research dating back 40 years that ties Foley catheter use to bladder trauma. This very research served as the impetus and compass for our design goals for the Duette™.

To begin, you may be interested in reading our White Paper. It reviews the basic premise of how bladder trauma is caused, and how we designed the Duette™ as a solution:

Download the White Paper

Below you will find several full length clinical studies, excerpts from others, and links to several addition studies, all of which substantiate the relationship between traditional catheter use and patient treatment complications.

Supporting Clinical Data for Duette™ Dual Balloon Technology

Novel Dual-Balloon Urinary Catheters Reduce Catheter-Associated Urinary Tract Infections
Chasin Zero: Reduction of CAUTIs in the SICU
Novel Dual-Balloon Urinary Catheters Reduce Catheter-Associated Urinary Tract Infections
One Unit's Novel Approach to Decrease CAUTIs
Duette™ Catheter Study Results

Clinical Research Overview

A Catheter Associated Lesion of the Human Bladder
Changes in the Urinary Bladder Caused by Short-Term Permanent Catheter Insertion
Foeley Catheter Design Flaws Exposed

The urinary bladder has two main functions: to store urine and to void urine. (Please refer to the image below for a more detailed look at the anatomy of the bladder) To aid in the fulfillment of these functions, the bladder has several innate (non-specific) immune defense mechanisms to avoid bacterial colonization. The bladder’s immune system is comprised of two primary functions:

  • the process of voiding (urination)
  • the mucin (GAG) coating of the bladder wall, which acts as a barrier to bacterial attachment

The innate immune system functions as a first line of defense to inhibit or prevent the attachment of bacteria to the bladder wall. These defensive mechanisms are crucial in keeping the bladder healthy, as bacterial colonization on the bladder wall is the first step in symptomatic urinary tract infection and its virulence.

Bladder Diagram

The following clinical documentation expresses the value of this system and how bacteria are able to dramatically increase attachment when it is damaged or removed. Please find areas highlighted yellow for a quick reference to key points in the study.

Relevant Studies

1. Antibacterial Mechanisms of the Urinary Bladder
Carl W. Norden, Gareth M. Green, Edward H. Kass
J Clin Invest. 1968 December; 47(12): 2689–2700.

2. Bladder Surface Mucin Effects Against Bacterial Species
C. L. Parsons, S. G. Mulholland
Am J Pathol. 1978 November; 93(2): 423–432.

3. Antibacterial Activity of Bladder Surface Mucin (When Mucin is Removed)
C. L. Parsons, S. G. Mulholland
H Anwarl. Infect. Immun. May 1979 vol. 24 no. 2 552-557

4. Mechanism of Bladder Wall Defense
Cox CE, Hinman F Jr.
J Urol. 1961 Dec;86:739-48.

5. The Role of the Urinary Epithelium as a Barrier
C. Lowell Parsons
Urology – April 2007 (Vol. 69, Issue 4, Supplement, Pages S9-S16)

The Role of the Foley Catheter in Damaging the Bladder’s Natural Defenses

Bladder catherterized with a Foley

The traditional Foley catheter has two fundamental flaws that work in concert to compromise the bladder’s natural defensive mechanisms. It features an exposed tip, which grinds against and sometimes embeds into the bladder wall during urinary drainage events. This friction strips away the mucosa lining of the bladder wall, allowing bacteria to attach and colonize this area of trauma. Second, the Foley design has drainage eyes that are unprotected. As the bladder drains, the bladder wall often becomes aspirated into the drainage eye itself, causing suction damage and blockage of urine flow.

Upon insertion of a catheter, drainage of urine from the bladder commences immediately. As the bladder drains, the dome and posterior walls collapse onto the catheter tip and around the drainage eyes. Multiple drainage events mean that the bladder wall will repeatedly collapse onto these damaging areas of the catheter, leading to a compromised protective mucin layer, swelling and hemorrhaging, and in severe cases, the embedding of the catheter tip in the bladder wall.

The following are clinical studies that document the trauma urinary catheters cause to the bladder’s natural innate immune system. However, it is interesting to note that many clinicians today believe most catheter damage results at the bladder neck. The following studies have shown that, contrary to this belief, the dome and posterior wall endure the brunt of the damage caused by the catheter tip, and, to a lesser degree, the suction aspiration of the drainage eyes.

Relevant Studies


8. Bladder Wall Study – Short TermCatheter Damage Abstract
Peychl L, Zalud R.
Cas Lek Cesk. 2008;147(6):325-9.

9. Catheter Tip Areas of Damage
(1979) POLYPOID CYSTITIS. Acta Pathologica Microbiologica Scandinavica Section A Pathology, 87A: 179–184.

10. Catheter Damage by Suction Aspiration
Glahn BE, Braendstrup O, Olesen HP.
Scand J Urol Nephrol. 1988;22(2):93-9.

11. Histological Changes Due to Urinary Catheters
(1989), Histological Changes in the Urinary Bladder Secondary to Urethral Catheterisation. British Journal of Urology, 63: 354–357.

12. Posterior Wall and Dome Damage
Ekelund P, Anderström C, Johansson SL, Larsson P.
J Urol. 1983 Sep;130(3):456-9.

13. Catheter Damage as a Cause of Infection
Gray, Mikel PhD, FNP, PNP, CUNP, CCCN
July/September 2010 – Volume 21 – Issue 3 – p 247–257

14. Catheter Averse Events

The Importance of Materials: Why 100 Percent Silicone Matters

Studies have also shown that the material of the catheter selected is crucial to reducing trauma levels during catheterization. The Duette™ a 100% silicone catheter.

15. The Effects of Catheter Material and Bacteria on Cells
Jessica M.T. Barford,Yanmin Hu, Ken Anson, Anthony R.M. Coates
The Journal of Urology, Volume 180, Issue 4 , Pages 1522-1526, October 2008

16. Comparison of Latex and Silicone Catheters in Human Trials
NACEY, J. N., TULLOCH, A. G. S. and FERGUSON, A. F. (1985), Catheter-induced Urethritis: a Comparison Between Latex and Silicone Catheters in a Prospective Clinical Trial. British Journal of Urology, 57: 325–328.

Future Updates

Please check back soon to see newly added clinical studies that will continue to aid us in understanding and addressing the the shortcomings of current urinary drainage technology.


The Duette™ relies on its third party studies to show how it has addressed adverse events from Foley urinary catheterization, providing better patient care and improved outcomes while attempting to reduce health care costs.

A healthy bladder wall is made up of layers that are clinically documented to have anti-bacterial properties that resist infection; the mechanical irritation of the bladder that occurs by introducing a traditional Foley catheter damages the wall thereby disrupting these innate defenses

The emptying bladder collapses on the exposed Foley tip results in trauma that breaks down the protective lining of the bladder wall. This damage is compounded by the exposed drainage eyes which result in the wall being aspirated into the eyes. This can result in:

  • Painful bladder spasms and urine leakage around the Foley catheter
  • Increased incidents of catheter-associated urinary tract infection (CAUTI)
  • An increased degree of sepsis
  • For chronic, long term uses of Foley catheters, an increased risk of cancer

“The fundamental reason catheterized patients are so vulnerable to infection is that the catheter violates the integrity of the defense systems that normally protect the bladder against infection. The indwelling Foley undermines this system.”

-An indwelling urinary catheter for the 21st Century, Roger C.L. Fenely, Calvin M.Kunin and David J. Stickler, 2011

If you would like additional usage information, please see the below documentation:

Duette Instructions for Use
Duette™ Catheter Care Guide