| Popis: |
A surgically created, totally autogenous venous valve has been devised that holds potential for the treatment of venous insufficiency. Valves were constructed from 2.7 cm long segments of canine external jugular veins. Through the use of intimal separation, folding, and suturing techniques, thin, pliable valves with an intimal lining were constructed and interposed in the canine superficial femoral vein. Fifteen valves were implanted in three groups of dogs. In group I (six dogs) the valves were immediately removed after implantation and subjected to various levels of hydrostatic pressure. In group 2 (six dogs) valves were removed after 1 week and examined for patency and competency. Group 3 animals (three dogs) were anticoagulated with subcutaneously administered heparin from implantation to removal at 7, 9, and 13 days. In group 1 valves were found to open at less than 3 cm of water and remain competent at 55 cm of water. Two of these valves subjected to 300 mm Hg pressure also remained competent. In the six group 2 dogs, two valves remained patent and competent, whereas four valves were patent but incompetent as a result of thrombus that prevented valve closure. In group 3 all valves were patent and competent at 7, 9, and 13 days after implantation. An autogenous venous valve that opens at physiologic pressures and remains competent at high pressures can be surgically created. The ability to remain competent at high pressures may give this valve an advantage over the repaired, transposed, or transplanted native venous valve in the treatment of chronic venous valvular insufficiency. |
