Instruction For The Safe Operation of Vascular Occluders

Important:

Before implantation--Operate the occluder in accordance with the instructions under Testing Procedure*
 
1. To avoid unintentional constriction, select the occluder size that provides a slightly loose fit around the subject vessel.
2. Wrap the occluder cuff around the exposed vessel and secure it in place using suture material passed through the eyelets and tied securely.
3. Exteriorize the actuating tube through a convenient incision.
4. When used in conjunction with a flow transducer, be sure to position the occluder distally, (down stream) from the transducer. If positioned upstream, the vessel will collapse during occlusion, resulting in loss of contact with the transducer's electrodes or crystals.
5. Occlusion may be determined in a chronic implantation by any of the following methods:
  a. Obliteration of phasic flow patterns displayed by the vessel under study. This is the recommended method for accurately determining zero-flow baseline in small vessels.
  b. Noting the amount of air pressure or Liquid volume injected, according to the previous calibration, see Testing Procedure*.
  c. Monitoring of inflation by injecting radiopaque fluid instead of water and viewing the action fluoroscopically.

Suggested Actuating Medias For Vascular Occluders:
The occluder may be activated by either pneumatic or hydraulic methods. Satisfactory results can be expected by injecting air, inert gas, or various liquids into the actuating tube. Some researchers prefer air because of it's simplicity, availability, and easy of pressure control. Others prefer water or Saline solution, especially for occlusions of longer duration, (up to one hour). As a precaution, sterile normal Saline solution or sterile distilled water are recommended for use with this device in case fluid is accidentally injected into the animal under study. For procedures requiring occlusion times in excess of one hour, sterile Glycerin has been used successfully by researchers due to the fact that Glycerin does not transpire through the Silicone rubber, it does not evaporate, and it is generally biocompatible.

Duration of Occlusion for Vascular Occluders:
Model VO vascular occluders, when used with water or Saline solution perform well for brief occlusions . Stable, long-term occlusion cannot be maintained with water due to it's tendency to transpire through silicone rubber. Short term occlusion of up to approximately one hour may be maintained successfully using water or Saline solution if pressure it applied slightly in excess of what is required to achieve full occlusion. For longer occlusion times, we recommend monitoring the degree of occlusion using any of the methods described in step 5 above, as well as selecting a liquid such as Glycerin as the actuating fluid. Glycerin done not transpire or evaporate easily through Silicone rubber; nor will it cause damage to the device.

*Testing Procedures are available either by going here or requesting a faxed copy.

Intended for Animal Research Only

Caution: Use extreme caution when using sharp objects during implantations. The occluder diaphragm and actuating tube can be easily cut or pierced.