ZRZT™
The Lin Zero-Residual Zero-Tip (ZRZT) Balloon Catheter ™
U.S. Patent 5,250,029
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Introduction to the currently used Foley (urinary) catheter
Foley catheters are standard catheters commonly used in urology to drain urine from the bladder. Almost 30 million Foley catheters are used each year in the U.S. for a wide variety of medical conditions. These include incontinence, urinary retention (such as after surgery, obstructive prostate enlargement, paraplegia, multiple sclerosis, etc.) and close medical monitoring during anesthesia, and in any intensive care setting.

The basic shape of the Foley catheter has remain unchanged for 6 decades, with a prominent tip and two drainage holes situated above the retention balloon.

This design presents four major drawbacks (See Fig. 1): 1.  There is no further bladder drainage once the urine level in the bladder falls to the level of the drainage holes atop the balloon. In a catheterized patient, residual urine from incomplete bladder drainage becomes stagnant and can serve as a growth medium for bacterial proliferation. Urinary tract infections, through increased morbidity, mortality and hospital days, cost over $1 billion annually in the U.S.* Incomplete drainage also leads to proteinaceous crusting and obstruction of catheter, concretion and sediment accumulation, and stone formation. (Fig. 2) 2.  The protruding tip against the delicate bladder mucosa often causes bladder irritation, pain, spasm or even pressure injury. It can also disrupt suture lines after bladder surgery, leading to serious complications. 3.  The catheter drainage holes near its tip can become occluded by adjacent bladder mucosa from suction force secondary to the downward gravity pull of a column of urine in the catheter or drainage tubing. This negative pressure suction phenomenon (akin to that in a soda-straw) prevents further bladder drainage and results in misleadingly low urine output measurements. False reading can lead to inappropriate and deleterious treatment(s), including unwarranted administration of intravenous fluids, drugs or other erroneous intervention in critically ill patients. 4.  When used as a three-way catheter for irrigation, the Foley design does not allow effective evacuation of heavier particles such as blood clots and stones — these settle to the bottom of the bladder and resist being flushed out through the catheter’s drainage hole, which is situated instead near the top.

Fig. 1 Fig. 2

The Lin Balloon Catheter overcomes all of the aforementioned drawbacks:

Fig. 3 The Lin catheter has an extra large drainage hole situated at the same level as the retaining balloon to allow complete drainage. (See Fig. 3 & 4)   Fig. 4

Fig. 5 The catheter tip "retracts" once the balloon is inflated and will not cause irritation or injury. (See Fig. 5)   Fig. 6 There is a buffering "gully" (formed by the inflated balloon) on each side of the drainage hole that keeps bladder mucosa away and prevents negative pressure suction from taking place. In an acute or critical care setting, it enables consistently error-free monitoring of urine output. (See Fig. 6)

A three-way ZRZT irrigation catheter incorporating the above features provides superior irrigation and complete drainage. Any large clots that develop after urologic surgery can be extracted via suction at the bedside, instead of a costly return trip to the operating room. The extra large drainage hole at the lowermost portion of the bladder allows blood clots, stones and mucous to be easily flushed out. The aforementioned buffering gully protects against mucosal injury from even aggressive suction (Figs. 7 & 8).

In radical cystectomy for bladder cancer, a neobladder is reconstructed from colon. Large amounts of colonic mucus are secreted in the post-operative period, which if not effectively flushed out, creates blockage and adversely affect surgical outcome. A Lin 3-way catheter is ideally suited to prevent such post-operative complications and attendant costs. It also saves other healthcare dollars many times its cost by reducing the use of voluminous sterile irrigation fluid and skilled nursing care. By reducing irrigation-induced hypothermia, the Lin catheter also enhances patient comfort and speed recovery. Lastly, adding an integral or external patient-controlled drainage valve enables cyclical filling and emptying of the bladder to simulate normal voiding behavior. This re-establishes bladder tone and prepares the patient for weaning from catheter dependence, and eliminates the need for urine collection bags and connecting tubes.

Summary

The Lin Zero-Residual Zero-Tip Balloon Catheter has been granted a strong U.S. patent (Number 5,250,029) with broad basic claims. It is available for licensing or purchase. For more information, please contact us through one of the following:

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Tel: 941-966-0890
Mail: 1109 Millpond Court, Osprey, Florida 34229-8863, USA

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