Vascular outflow resistance and angiographic assessment of lower limb arterial reconstructive procedures.
In an attempt to predict early graft occlusion secondary to poor distal run-off, the outflow resistance was measured intra-operatively and compared with the intra-operative angiogram in 50 patients undergoing lower limb bypass procedures. With arterial inflow occluded, 60 mL of plasmalyte was infused via a catheter and the resultant pressure generated in the graft was measured through a second catheter connected to a pressure transducer and recorder. Using the infusion rate and integrated pressure value, outflow resistance was calculated. High resistance measurements were defined as grafts with outflow resistance greater than 1.1 mmHg/mL per min, low measurements were defined as values less than 0.5 mmHg/mL per min and intermediate measurements were those in the range 0.5-1.1 mmHg/mL per min. Angiograms were classified independently of resistance measurements by scoring the numbers of run-off vessels crossing the ankle and stenoses, with subsequent assignment of the patient to one of three groups with either low, intermediate, or high probability of graft failure. Early graft failure was defined as cessation of graft function within 3 months of surgery. Early graft failure occurred in both cases with high outflow resistance and in seven of 44 with low outflow resistance. Of these nine occluded bypasses, six had been placed in the high probability of occlusion category on angiographic appearance and three in the intermediate category. Assessment of angiographic appearance and prediction of patency on a prospective basis had a sensitivity rate of 67% and a specificity rate of 78%. The corresponding sensitivity and specificity rates with resistance measurements were 22% and 100%, respectively.(ABSTRACT TRUNCATED AT 250 WORDS)
Miller
J
J
Vascular Surgery Unit, Flinders Medical Centre, Bedford Park, South Australia.
Walsh
J A
JA
Foreman
R K
RK
Dupont
P A
PA
Luethke
R
R
James
M J
MJ
Iannos
J
J
D000368:Aged; D000369:Aged, 80 and over; D000792:Angiography; D001157:Arterial Occlusive Diseases / Q000000981:diagnostic imaging / Q000503:physiopathology / Q000601:surgery; D005260:Female; D006083:Graft Occlusion, Vascular / Q000000981:diagnostic imaging / Q000503:physiopathology; D006801:Humans; D007866:Leg / Q000098:blood supply*; D008297:Male; D008875:Middle Aged; D011237:Predictive Value of Tests; D012680:Sensitivity and Specificity; D014655:Vascular Resistance; D014656:Vascular Surgical Procedures