A method of performing descending venography.

With the recent development of successful methods to correct valve incompetence in the lower extremity, there is a need for a standardized approach to descending venography. This is the single test that accurately defines the site of the venous valve and demonstrates its competence or degree of incompetence. This report describes a technique of descending venography, including the details of catheter placement, injection procedure, and monitoring techniques. Interpretation of the study requires a method that analyzes both the individual valve function and the overall valvular competence of the entire extremity. Descending venography can separate patients with primary valve incompetence from those with postthrombotic valve destruction, as well as the occasional case of valve aplasia. Points on interpretation of valve function and the use of the Valsalva maneuver for "stressing" the valve are discussed. The descending venographic results are compared with the clinical state and with venous pressure findings in 78 extremities.