Colour flow imaging in the detection of femoro-distal graft and native artery stenosis: Improved criteria

doi:10.1016/S0950-821X(05)80310-X

European Journal of Vascular Surgery

Volume 6, Issue 3, May 1992, Pages 232-236

https://doi.org/10.1016/S0950-821X(05)80310-X Get rights and content

Vein graft or native artery stenosis after femoro-distal revascularisation is a common cause of graft occlusion. The early detection and treatment of such stenoses offers the potential for better graft patency than salvage procedures undertaken for graft thrombosis. In the past, two criteria using duplex scanning have been used to detect grafts at risk: (a) a localised increase in the peak velocity (V2) by 100% or more in comparison to the peak velocity (V1) 2cm upstream (i.e. V2/V1 ratio > 2.0), and (b) a decrease in average peak velocity to less than 45 cm s⁻¹. Seventy-four consecutive patients with femoro-distal vein grafts have been studied with intravenous digital subtraction angiography to detect stenosis (>50% diameter) and colour flow imaging using both duplex scanning criteria (a) and (b) at 1.5, 3, 6, 9 and 12 months after operation. The results show that the V2:V1 ratio > criterion had a sensitivity of 100% and a specificity of 83%. Stenoses in the native distal arteries were not detected. Low average peak velocity <45 cm s⁻¹ had a sensitivity of 61% and a specificity of 98%. By combining both criteria the sensitivity for detecting stenoses in both the vein graft and native distal artery, became 100% and the specificity 98%.

References (10)

VeithFJ et al.
Six year prospective multi-centre randomised comparison of autologous saphenous vein and expanded polytetrafluoroethylene grafts in infrainguinal arterial reconstructions
J Vasc Surg
(1986)
RutherfordRB et al.
Factors affecting the patency of infrainguinal bypass
J Vasc Surg
(1988)
GriggMJ et al.
Detection and grading of femorodistal vein graft stenoses: duplex velocity measurements compared with angiography
J Vasc Surg
(1988)
HarrisPL et al.
A prospective randomised clinical trial to compare in situ and reversed vein grafts for femoropopliteal bypass
Br J Surg
(1987)
WhittemoreAD et al.
Secondary femoro-popliteal reconstruction
Ann Surg
(1981)

There are more references available in the full text version of this article.

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Chapter II: Diagnostic methods
2011, European Journal of Vascular and Endovascular Surgery
Citation Excerpt :
Venous grafts may fail due to de novo obstructions either within the body of the graft or at the anastomoses (intimal hyperplasia), or due to progression of atherosclerotic obstructions upstream or downstream from the graft. DUS surveillance studies can detect these obstructions during impeding graft thrombosis with greater sensitivity than evaluation by clinical history, physical examination, or use of the resting ABI.1,91–96 In general, low velocities indicate poor arterial inflow, proximal stenosis, or large graft diameter.
Non-invasive vascular studies can provide crucial information on the presence, location, and severity of critical limb ischaemia (CLI), as well as the initial assessment or treatment planning.
Ankle-brachial index with Doppler ultrasound, despite limitations in diabetic and endstage renal failure patients, is the first-line evaluation of CLI. In this group of patients, toe-brachial index measurement may better establish the diagnosis. Other non-invasive measurements, such as segmental limb pressure, continuous-wave Doppler analysis and pulse volume recording, are of limited accuracy. Transcutaneous oxygen pressure (TcPO₂) measurement may be of value when rest pain and ulcerations of the foot are present. Duplex ultrasound is the most important non-invasive tool in CLI patients combining haemodynamic evaluation with imaging modality.
Computed tomography angiography (CTA) and magnetic resonance angiography (MRA) are the next imaging studies in the algorithm for CLI. Both CTA and MRA have been proven effective in aiding the decision-making of clinicians and accurate planning of intervention. The data acquired with CTA and MRA can be manipulated in a multiplanar and 3D fashion and can offer exquisite detail. CTA results are generally equivalent to MRA, and both compare favourably with contrast angiography. The individual use of different imaging modalities depends on local availability, experience, and costs. Contrast angiography represents the gold standard, provides detailed information about arterial anatomy, and is recommended when revascularisation is needed.
Peripheral Arterial Disease: Clinical Evaluation
2006, Vascular Medicine: A Companion to Braunwald's Heart Disease
Peripheral arterial disease: Clinical evaluation
2006, Vascular Medicine
Intra-operative Doppler flow measurement do not predict 'At-risk' status of infrainguinal bypass grafts
2005, European Journal of Vascular and Endovascular Surgery
Citation Excerpt :
At risk (AR) status was defined as those criteria that determined a 50% or more reduction in diameter which equated to a 75% or more reduction in cross-sectional area.14 Thus graft segments that demonstrated a focal two-fold increase in the velocity ratio (velocity ratio, PSV Vr, where Vr=PSV atlesion/PSVproximaltolesion) (Vr≥2.0) were regarded as at risk.14–16 Stenosis grading was primarily based on the concept that a doubling of PSV equated to a 50% or greater diameter stenosis.
Patients undergoing infrainguinal arterial reconstruction using vein conduits, frequently undergo intra-operative Doppler flow measurements to determine technical adequacy. The aim of this study was to determine the proportion of vein grafts with normal intra-operative haemodynamic parameters that were subsequently discovered to be ‘at risk’ on post-operative duplex surveillance scanning.
We prospectively collected data on 82, primary infrainguinal vein bypass grafts. Post papaverine graft flow and peripheral resistance were measured using the Scimed Opdop^® intra-operative Doppler machine. All grafts were determined to be technically adequate on the basis of measured peripheral resistance units (mPRU) being ≤1. At 1 week, a post-operative duplex surveillance scan was performed. At risk status was determined and compared to the intra-operative Doppler flow measurement. Statistical analysis was performed using the Mann–Whitney U-test.
The post-operative duplex scan demonstrated that 53 (65%) of the 82 vein bypass grafts were diagnosed as being ‘not at risk’; and 29 (35%) were regarded as at risk. When the groups were compared, there was no significant difference in intra-operative haemodynamic parameters between those not at risk and those at risk (P=0.19, Mann–Whitney U-test). The 1 month primary patency rate was 79% with a secondary patency rate of 100%.
Despite normal intra-operative Doppler flow measurements, 35% of vein grafts were regarded as being at risk at the 1 week post-operative duplex surveillance scan. No single value may be universally applicable for identifying at risk grafts intraoperatively. Indeed, graft failure appears to be a multifactorial process.
Identification of factors predictive of lower extremity vein graft thrombosis
2001, Journal of Vascular Surgery
Citation Excerpt :
The association between graft thrombosis, PSV, and EDV exists only when these parameters reach high velocities, more 400 cm/s and more than 50 cm/s, respectively. The suggestion that low peak systolic flow velocity predicts vein graft failure was first made by Bandyk et al.22 A number of investigators have used low flow velocity criteria, typically less than 45 cm/s, to detect at-risk grafts.16,18,19,21,23,24 There have been no studies, however, that have identified the ideal “cut point” in terms of the PSV below which grafts are at risk of failure.
Objective: The objective of this study was to assess the prognostic value of hemodynamic parameters measured with duplex ultrasound scan, together with other important graft and patient characteristics, in predicting lower extremity vein graft thrombosis. Methods: A total of 165 lower extremity vein grafts were entered prospectively into a postoperative duplex ultrasound scan surveillance program with examinations performed at 1, 2, 3, 4, 6, 9, 12, 18, and 24 months, and annually thereafter. Duplex scan–derived blood flow velocity measurements were recorded at 1562 patient visits over 7 years. Graft patency was determined after each visit, and an analysis of factors predictive of vein graft thrombosis was performed with Poisson regression. Results: Thirty-two episodes of first-time graft thrombosis occurred, 23 of which were permanent. One-, 3-, and 5-year secondary graft patency rates were 90%, 86%, and 79%, respectively. In multivariate analyses, duplex scan velocity measurements predictive of lower extremity graft thrombosis included the maximum velocity ratio (Vr) in association with a graft stenosis and the mean graft peak systolic velocity (MGV) within nonstenotic portions of the body of the graft. The incidence of graft thrombosis among grafts without inflow/outflow stenoses, with Vr less than 3.5, and with MGV 50 cm/s or more, was 2.9% per year. Incidence rates were considerably higher among grafts with a of Vr of 3.5 or more (incidence rate ratio = 7.0; 95% CI, 3.4-14.6) or an MGV less than 50 cm/s (incidence rate ratio = 6.5; 95% CI, 3.3-13.1). In grafts without identifiable inflow, outflow, or graft stenoses, there was no association between MGV and the risk of graft thrombosis. Conclusion: Duplex scan velocity measurements are valid predictors of impending graft thrombosis. A Vr of 3.5 or more and an MGV less than 50 cm/s are the best predictive measures. Repair of correctable graft lesions with a Vr of 3.5 or more, or inflow, outflow, or graft lesions associated with an MGV less than 50 cm/s are recommended. Grafts without detectable inflow, outflow, or graft stenoses, regardless of MGV, may be safely followed. (J Vasc Surg 2001;33:24-31.)
The natural history of intermediate and critical vein graft stenosis: Recommendations for continued surveillance or repair
2001, Journal of Vascular Surgery
Objective: Duplex ultrasound surveillance (DUS) after autogenous lower extremity bypass grafting is controversial. Specific criteria mandating graft revision are not uniform. It has been suggested that grafts harboring critical stenoses undergo revision, whereas those with intermediate stenoses undergo arteriography with selective repair. We sought to define the natural history and determine the risk of graft occlusion associated with unrepaired vein graft stenoses. Methods: We analyzed serial vascular laboratory and clinical data of 156 autogenous infrainguinal vein grafts in 142 patients. Grafts were categorized into three groups according to the first DUS-detected (index) lesion: (1) normal (peak systolic velocity [PSV] < 200 cm/s, velocity ratio [V_r] < 2); (2) intermediate stenosis (200 cm/s < PSV < 300 cm/s, 2 < V_r < 4); and (3) critical (PSV > 300 cm/s, V_r > 4). Our policy was to repair grafts with critical lesions and monitor all others. The risks of stenosis progression, graft revision, and graft thrombosis for each group were compared. Results: Serial DUS was normal in 100 (64%) grafts. The incidence of graft thrombosis in the normal group was 3% per year (mean follow-up, 27.5 months). Intermediate lesions developed in 32 grafts (20%) and were followed. Among these 32 grafts with intermediate stenoses, 63% progressed to critical and were revised, and 32% resolved or stabilized (mean follow-up, 26 months). Only one graft occlusion occurred in grafts with intermediate lesions subjected to serial DUS monitoring (incidence 1.5% per year, P = not significant). In the third group, 16 of 25 grafts with critical lesions were successfully revised and remain patent. In nine cases, critical lesions were not repaired, resulting in seven (78%) occlusions, all within 4 months of DUS detection. Conclusions: Serial surveillance is safe and effective for grafts with intermediate stenoses. The graft occlusion rate for such grafts with careful monitoring is no different from grafts without stenosis, and therefore, arteriography is not indicated in the absence of progression to critical stenosis. The short-term risk of graft occlusion in the presence of an unrevised critical stenosis is nearly 80%. These data have important clinical implications concerning the natural history of vein graft lesions. (J Vasc Surg 2001;33:273-80.)

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Colour flow imaging in the detection of femoro-distal graft and native artery stenosis: Improved criteria

J Vasc Surg

J Vasc Surg

J Vasc Surg

A prospective randomised clinical trial to compare in situ and reversed vein grafts for femoropopliteal bypass

Br J Surg

Secondary femoro-popliteal reconstruction

Ann Surg