U544989.pdf (38.62 MB)
Approaches to the assessment of combined segment vascular disease.
thesisposted on 2015-11-19, 08:52 authored by Antony Richard. Baker
Co-existing aorto-iliac and femoro-popliteal disease is difficult to manage. Arteriography does not shew the relative importance of the two components. Proximal reconstruction alone fails to relieve symptoms in 20-50% of cases. Total repair in all cases may increase mortality and morbidity and would involve uneccessary procedures in many patients. Haemodynamic information may allow pre-operative identification of the group in whom total repair is necessary. A canine model of aorto-iliac disease shewed that Doppler recordings are reliable in monitoring flew increases during a hyperaemic test. Indices were derived from the pressure and Doppler readings. These were shewn to provide more accurate characterisation of stenoses than either pressure or flew alone. These indices were then investigated in patients with peripheral vascular disease where they gave increased accuracy in the assessment of the aorto-iliac segment. The success of proximal reconstruction depends on what distal disease remains uncorrected. Many haemodynamic methods have been advocated for the assessment of the femoro-popliteal segment. In a canine model of combined segment disease segmental pressure gradient and several Doppler methods were compared. Pressure measurement was superior to the Doppler methods in characterising distal disease. Of the Doppler techniques Pulsatility Index Damping Factor was particularly disappointing. The reason for this was that arterial stenosis results in reduction of Pulsatility Index both distally and also proximally. The methods were then investigated in vascular patients. The best Doppler results were obtained with Normalised Transit Time. Damping Factor again produced disappointing results and its addition to Normalised Transit Time did not produce a statistically significant improvement in the area of clinical relevance. Segmental pressure measurement provided the most accurate assessment of the femoro-popliteal segment. None of the Doppler methods was sufficiently accurate for reliable clinical use. Pressure measurements are required for accurate haemodynamic assessment in both the aorto-iliac and femoro-popliteal segments.
Date of award1986-01-01
Author affiliationCollege of Medicine, Biological Sciences and Psychology
Awarding institutionUniversity of Leicester