Related Experiment Videos
Collateral back pressure--is it a valid predictor of infrainguinal bypass graft patency?
Insights
Collateral back pressure (CBP) and outflow resistance (OR) predict graft patency after bypass surgery. Outflow resistance was found to be a more reliable predictor than CBP and angiographic criteria.
Area of Science:
- Vascular Surgery
- Hemodynamics
- Graft Patency Prediction
Background:
- Collateral back pressure (CBP) is traditionally considered a predictor of graft patency.
- Previous validation of CBP's predictive capability has been limited.
- A novel, less invasive method for CBP measurement is introduced.
Purpose of the Study:
- To validate the correlation between collateral back pressure (CBP) and graft patency.
- To compare the predictive value of CBP and outflow resistance (OR) for infrapopliteal graft patency.
- To assess the reliability of CBP compared to angiographic criteria.
Main Methods:
- A new technique was employed to measure CBP in 84 lower extremity bypass grafts (43 femoropopliteal, 41 femorodistal) without direct arterial puncture.
- Outflow resistance (OR) was measured in 70 grafts using a previously described method.
- Graft patency was assessed at 3 months, and correlations with CBP, OR, and angiographic findings were analyzed.
Main Results:
- Mean CBP differed significantly between femoropopliteal (41 mmHg) and femorodistal (26 mmHg) bypasses.
- Early graft patency correlated significantly with both CBP (patent: 36 mmHg vs. occluded: 22 mmHg) and OR (patent: 0.36 mmHg/ml/min vs. occluded: 1.29 mmHg/ml/min).
- Outflow resistance emerged as a superior predictor of infrapopliteal graft patency compared to CBP and angiographic criteria via logistic regression analysis.
Conclusions:
- Collateral back pressure (CBP) is a significant predictor of graft outcome, outperforming angiographic assessments.
- Outflow resistance (OR) is a more reliable predictor of infrapopliteal graft patency than CBP.
- The study introduces a practical method for CBP measurement, aiding in the assessment of bypass graft viability.
Abstract:
While it is generally thought that collateral back pressure (CBP) is a reliable predictor of graft patency, this correlation has not yet been validated. We have used a new, simple technique to measure CBP without direct puncture of the recipient artery. After the distal anastomosis is completed, the graft is filled with saline and clamped proximally. A transducer connected needle is then inserted into the distal portion of the graft for CBP measurements (mm Hg). These were obtained in 84 grafts (43 femoropopliteals [FP] and 41 femorodistals [FD]). Outflow resistance (OR) measurements (mm Hg/ml/min) were also obtained in 70 (36 FP; 34 FD) of these grafts by a previously described technique. The mean CBP for FP and FD bypasses was 41 +/- 17 and 26 +/- 19 mm Hg, respectively (P less than 0.001). Although early graft patency (3 months) (13 occluded, 71 patent) did not correlate with angiographic findings of popliteal runoff or integrity of pedal arch, it did significantly relate to CBP. Mean CBP for occluded grafts was 22 +/- 17 mm Hg and for patent grafts it was 36 +/- 19 mm Hg (P less than 0.01). Similarly, mean OR was significantly related to patency, 1.29 +/- 0.23 mm Hg/ml/min for occluded grafts and 0.36 +/- 0.23 mm Hg/ml/min for patent grafts (P less than 0.0001). Moreover, only OR was a significant predictor of infrapopliteal graft patency (P less than 0.01). OR was found to be a better predictor of graft patency than CBP by stepwise logistic regression analysis (P less than 0.0001). We conclude that CBP is a more reliable predictor of graft outcome than angiographic criteria.(ABSTRACT TRUNCATED AT 250 WORDS)