Popliteal artery volume flow measurement: A new and reliable predictor of early patency after infrainguinal balloon angioplasty and subintimal dissection

Pulsatility index-adjusted doppler flow measurement of pedal arteries in peripheral artery disease patients

BACKGROUND

To examine the feasibility of using pulsatility index-adjusted (PI) flow equations to accurately characterize blood volume flow changes using Doppler technique in patients with peripheral artery disease (PAD) before and after percutaneous transluminal angioplasty (PTA).

METHODS

PTA was performed on 17 PAD patients (23 target vessels treated, 16 anterior tibial arteries, and 7 posterior tibial arteries). Arterial diameter, peak systolic velocity, PI, time-averaged mean velocity, and measured volume flow (MVF) of dorsalis pedis artery (DPA) and common plantar artery (CPA) were measured with duplex Doppler ultrasound before and after PTA. PI-adjusted volume flows (PIVF) were calculated as part of the MVF/PIVF relative percentage metric.

RESULTS

Significant changes (p < 0.001) of the MVF (mean: 33.0 mL/min, range: -20.9-102.2 mL/min) and MVF/PIVF relative percentages (mean: 51.8, range: 5.1-127.2%) in the DPA existed between before and after PTA, whereas no significant changes could be found in the CPA (mean:10.9 mL/min, p = 0.148 and mean: 21.3%, p = 0.146, respectively). Of the 7 treated posterior tibial arteries, the increments of the MVF/PIVF (mean: 60.4%, p = 0.033) was significant but not in the MVF (mean: 26.5 mL/min, p = 0.125). The ankle-brachial index also showed non-significant changes (p = 0.081). All PI-adjusted results matched clinical observations after blood flow restoration.

CONCLUSION

No conclusions can be drawn from the comparison of actual measured volume flow between before and after PTA. However, using the MVF/PIVF relative percentage allows for a more objective framework upon which to base clinical observations and provides clarity in situations where direct measurement provides a counter-intuitive or contradictory picture.

Effects of Enhanced External Counterpulsation With Different Sequential Levels on Lower Extremity Hemodynamics

Objective: This study aimed to investigate acute hemodynamics of lower extremities during enhanced external counterpulsation with a three-level sequence at the hips, thighs, and calves (EECP-3), two-level sequence at the hips and thighs (EECP-2), and single leg three-level sequence (EECP-1).

Methods: Twenty healthy volunteers were recruited in this study to receive a 45-min EECP intervention. Blood flow spectrums in the anterior tibial artery, posterior tibial artery, and dorsalis pedis artery were imaged by Color Doppler ultrasound. Mean flow rate (FR), area, pulsatility index (PI), peak systolic velocity (PSV), end-diastolic velocity (EDV), mean flow velocity (MV), and systolic maximum acceleration (CCAs) were sequentially measured and calculated at baseline during EECP-3, EECP-1, and EECP-2.

Results: During EECP-3, PI, PSV, and MV in the anterior tibial artery were significantly higher, while EDV was markedly lower during EECP-1, EECP-2, and baseline (all P < 0.05). Additionally, ACCs were significantly elevated during EECP-3 compared with baseline. Moreover, FR in the anterior tibial artery was significantly increased during EECP-3 compared with baseline (P = 0.048). During EECP-2, PI and MV in the dorsalis pedis artery were significantly higher and lower than those at baseline, (both P < 0.05). In addition, FR was markedly reduced during EECP-2 compared with baseline (P = 0.028). During EECP-1, the area was significantly lower, while EDV was markedly higher in the posterior tibial artery than during EECP-1, EECP-2, and baseline (all P < 0.05). Meanwhile, FR of the posterior tibial artery was significantly reduced compared with baseline (P = 0.014).

Conclusion: Enhanced external counterpulsation with three-level sequence (EECP-3), EECP-2, and EECP-1 induced different hemodynamic responses in the anterior tibial artery, dorsalis pedis artery, and posterior tibial artery, respectively. EECP-3 acutely improved the blood flow, blood flow velocity, and ACCs of the anterior tibial artery. In addition, EECP-1 and EECP-2 significantly increased the blood flow velocity and peripheral resistance of the inferior knee artery, whereas they markedly reduced blood flow in the posterior tibial artery.

Doppler Flow Measurement of Lower Extremity Arteries Adjusted by Pulsatility Index

OBJECTIVE. The purposes of this study were to estimate the blood volume flow of the lower extremities by means of Doppler technique; to establish a quantitative relationship between volume flow and pulsatility index (PI) in both healthy subjects and patients with peripheral artery disease (PAD); and to derive arterial blood flow equations in the lower extremities for more accurate volume flow estimations. SUBJECTS AND METHODS. Sixty healthy subjects were recruited. Arterial diameter, peak systolic velocity, PI, time-averaged mean velocity, and volume flow of right lower extremity arteries were measured with duplex Doppler ultrasound. Linear regression analysis was used to evaluate the relationship between volume flow and the reciprocal of PI. This quantitative relationship was also used to assess flow changes in 10 patients with PAD before, after, or both before and after percutaneous angioplasty. RESULTS. Volume flow in the common femoral artery was 434.4 mL/min; superficial femoral artery, 172.5 mL/min; popliteal artery, 92.1 mL/min; dorsalis pedis artery, 11.8 mL/min; and common plantar artery, 12.0 mL/min. Linear relationships between the reciprocal of PI and volume flow were found and expressed as linear blood flow equations. For the patients with PAD, no statistical increase in measured flow in the downstream artery after percutaneous angioplasty was found (p = 0.1), although four arteries had decreased flow. After normalization of flow measurements with PI values, however, statistical increases were observed between percentage increment (p < 0.001) calculations. CONCLUSION. When real-time PI values are factored into blood volume flow calculations in the evaluation of lower extremity arteries, discrepancies in flow measurements can be resolved, resulting in more accurate and stable measurements of clinical and diagnostic significance.

Iatrogenic percutaneous vascular injuries: clinical presentation, imaging, and management

Vascular interventional radiology procedures are relatively safe compared with analogous surgical procedures, with overall major complication rates of less than 1%. However, major vascular injuries resulting from these procedures may lead to significant morbidity and mortality. This review will discuss the etiology, clinical presentation, diagnosis, and management of vascular complications related to percutaneous vascular interventions. Early recognition of these complications and familiarity with treatment options are essential skills for the interventional radiologist.

Clinical efficacy of successful angioplasty in critical ischemia--a cohort study

BACKGROUND

To evaluate the impact of percutaneous angioplasty (PA), objectively assessed with duplex-ultrasound, on 3-year clinical outcome.

METHODS

Thirty-nine patients with atherosclerotic disease successfully treated by PA were included (40 limbs). All patients had critical ischemia with rest pain and ischemic ulcers due to infrainguinal obstructions alone. The patients were submitted to duplex ultrasound examination on the day before and on the first or second day after the procedure. Peak systolic velocities (PSV) were recorded in the anterior tibial, posterior tibial, and fibular arteries at the level of distal third of the leg. All patients were followed for 3 years. Comparison between groups with good and bad results were based on perioperative VPS gradient (GPSV) of the mean of the VPS in the 3 arteries. After 3 years, a good result was defined as a patient having no pain and complete healing of a previous ulcer or minor amputations.

RESULTS

Mean age was 68.5±8.1 years with no difference in demographic characteristics (P>0.05). In 26 cases, the long-term result was good. Healing time ranged from 4 to 130 weeks (median 26.5). Bad long-term results were observed in 12 cases. Two lesions remained unhealed despite patent angioplasty. In 10 cases, a second procedure was carried out (repeat angioplasty in 6 and bypass in 4). TransAtlantic Inter-Society Consensus (TASC) II category A/B registered better clinical success then TASC II category C/D (P<0.05) at 1-year follow-up but not at 3 years (P=0.36). Two-year limb salvage was 92.5%±4.2%. Primary patency was 52.5%±9.5% at 3 years. GVPS was 21.9 cm/sec in the good results group and 24.7 cm/sec in the bad results group (P>0.05). The quality of the initial result, as measured by GPSV, was not associated with long-term success (P>0.05).

CONCLUSIONS

An initially successful procedure indicated by the degree of increased flow is not related to long-term durability and ulcer healing.

Predictive factors of femoropopliteal patency after suboptimal duplex-guided balloon angioplasty and stenting: is recoil a bad sign?

Currently, the value of stenting during femoropopliteal balloon angioplasty (FPBA) remains unclear. Herein we evaluate the patency rates of successful duplex-guided balloon angioplasty (DAGBA) alone versus suboptimal DAGBA followed by stenting and the prestenting dissection versus recoil as potential indicators of stent success or failure. Over a period of 27 months, we performed 291 duplex-guided FPBAs (194 stenoses; 97 occlusions) on 244 limbs in 220 patients. Disabling claudication was the indication in 67%. Critical limb ischemia was the indication in the remaining 33%. Self-expanding nitinol stents were used when plaque dissection and/ or recoil caused diameter reduction > or = 40%. Serial follow-up duplex scans were obtained. Severe restenosis (> 70%) was measured by B-mode imaging and a peak systolic velocity ratio > 3. Follow-up ranged from 1 to 41 months (mean 10 +/- 8.3 months). The overall mean interval for restenosis and occlusion was 6.5 +/- 4.2 months and 5.6 +/- 6.1 months, respectively. Stents did affect overall patency results compared with not using stents. Reasons for stenting were plaque recoil, dissection, or both in 98 (53%), 44 (24%), and 42 (23%) cases, respectively. Six-month patency was 59%, 94%, and 69%, respectively. The difference between plaque recoil and dissection was significant (p<.04). The use of stents during FPBA may be associated with balloon angioplasty site failure in the femoropopliteal segment. To our knowledge, this is the first report ever to document plaque recoil as a predictor of balloon angioplasty site failure notwithstanding stent placement.