Comparison of Magnetic Resonance Angiography (MRA) and Duplex Ultrasound Arterial Mapping (DUAM) prior to infrainguinal arterial reconstruction

Mid-term outcomes of an everolimus-eluting bioresorbable vascular scaffold in patients with below-the-knee arterial disease: A pooled analysis of individual patient data

Previous studies on everolimus-eluting bioresorbable vascular scaffolds (BVS) have shown promising 1-year primary patency rates in infrapopliteal arteries. Literature from large cohorts on long-term outcomes with the infrapopliteal Absorb BVS (Abbott Vascular) is lacking. The aim of this study is to pool published and unpublished data to provide a more precise estimate of the 24-month outcomes of Absorb BVS for the treatment of infrapopliteal disease. For the pooled analysis, updated original and newly collected data from three cohorts on treatment with the Absorb BVS for de novo infrapopliteal lesions were combined. The primary endpoint was freedom from restenosis. Secondary endpoints were freedom from clinically driven target lesion revascularization (CD-TLR), major amputation and survival. The pooled analysis included a total of 121 patients with 161 lesions, treated with 189 Absorb BVS in 126 limbs. The mean age of the patients was 73 years, 57% had diabetes mellitus, and 75% were classified as Rutherford-Becker class 5 or 6. Of the 161 lesions, 101 (63%) were calcified and 36 (22%) were occlusions. Successful deployment was achieved with all scaffolds. Freedom from restenosis was 91.7% and 86.6% at 12 and 24 months, respectively, and freedom from CD-TLR was 97.2% and 96.6%. Major amputation occurred in 1.6% of the limbs. Overall survival was 85% at 24 months. In conclusion, this pooled analysis represents the largest reported analysis of mid-term results of the Absorb BVS for the management of chronic limb-threatening ischemia. At 24 months, the Absorb BVS was safe with promising clinical outcomes for the treatment of infrapopliteal disease.

Long-Term Follow-up of the PADI Trial: Percutaneous Transluminal Angioplasty Versus Drug-Eluting Stents for Infrapopliteal Lesions in Critical Limb Ischemia

BACKGROUND

Clinical outcomes reported after treatment of infrapopliteal lesions with drug-eluting stents (DESs) have been more favorable compared with percutaneous transluminal angioplasty with a bailout bare metal stent (PTA-BMS) through midterm follow-up in patients with critical limb ischemia. In the present study, long-term results of treatment of infrapopliteal lesions with DESs are presented.

METHODS AND RESULTS

Adults with critical limb ischemia (Rutherford category ≥4) and infrapopliteal lesions were randomized to receive PTA-BMS or DESs with paclitaxel. Long-term follow-up consisted of annual assessments up to 5 years after treatment or until a clinical end point was reached. Clinical end points were major amputation (above ankle level), infrapopliteal surgical or endovascular reintervention, and death. Preserved primary patency (≤50% restenosis) of treated lesions was an additional morphological end point, assessed by duplex sonography. In total, 74 limbs (73 patients) were treated with DESs and 66 limbs (64 patients) were treated with PTA-BMS. The estimated 5-year major amputation rate was lower in the DES arm (19.3% versus 34.0% for PTA-BMS; P=0.091). The 5-year rates of amputation- and event-free survival (survival free from major amputation or reintervention) were significantly higher in the DES arm compared with PTA-BMS (31.8% versus 20.4%, P=0.043; and 26.2% versus 15.3%, P=0.041, respectively). Survival rates were comparable. The limited available morphological results showed higher preserved patency rates after DESs than after PTA-BMS at 1, 3, and 4 years of follow-up.

CONCLUSIONS

Both clinical and morphological long-term results after treatment of infrapopliteal lesions in patients with critical limb ischemia are improved with DES compared with PTA-BMS.

CLINICAL TRIAL REGISTRATION

URL: http://www.clinicaltrials.gov. Unique identifier: NCT00471289.

Comparison of Computed Tomography Angiography to Contrast Arteriography for Patients Undergoing Evaluation for Lower Extremity Revascularization

In an effort to explore alternatives to contrast arteriography, we compared computed tomography angiography to contrast arteriography for defining anatomic features of patients undergoing lower extremity revascularization. From November 2003 to March 2004, 36 inpatients with chronic lower extremity ischemia underwent contrast arteriography and computed tomography angiography before undergoing lower extremity revascularization procedures. A Siemens 16 slice multiplanar computed tomography device with bolus tracking was used for these exams. The reports of these tests and images were compared prospectively, and the differences in the aorto-iliac segment, femoral-popliteal, and infrapopliteal segments were noted. The vessels were classified as mild disease (<50%), moderate disease (50%-70%), severe (71%-99%), and occluded. The studies and treatment plans based on these data were compared. The mean age was 76 ± 12 years (SD). Indications for the procedures included gangrene (45%), ischemic ulcer (32%), rest pain (19%), and severe claudication (3%); 69% were diabetics. Accuracy of computed tomography angiography in the aorto-iliac, femoral-popliteal, and infrapopliteal segments was 100%, 81%, and 59%, respectively. Thirteen of 18 (72%) of these disagreements resulted in a different procedure than that suggested by computed tomography angiography. A review of the data obtained in this series indicated that computed tomography angiography appears to be unable to obtain adequate information in this highly selected population at our institution.

Screening Algorithm for Aortoiliac Occlusive Disease Using Duplex Ultrasonography–Acquired Velocity Spectra from the Distal External Iliac Artery

Aortoiliac duplex scanning can be difficult to perform owing to the deep location of these vessels. We propose a new method to indirectly screen for aortoiliac disease by performing duplex examination of the distal external iliac artery (DEIA). After performing a preliminary study on 21 patients, the parameters of the Doppler waveform that best distinguish normal from diseased arteries were the presence or absence of reverse flow, peak systolic velocity, and resistance index. These values were used in a derived equation, with the value Y ≥ 0.78 predicting normal proximal inflow. We then studied 118 aortoiliac segments in 81 consecutive patients with arteriography and DEIA duplex ultrasonography. To predict moderate to severe stenosis, duplex ultrasonography had a sensitivity of 95.7%, a specificity of 84.1%, a positive predictive value of 80%, and a negative predictive value of 96.8%. Our formula thus predicted significant disease in 55 of the 118 aortoiliac segments (47%), with these segments needing further arteriographic evaluation. The other 63 limbs can be safely considered as having normal aortoiliac inflow.

Our method accurately screens for aortoiliac disease and is excellent for predicting normal inflow. This information can be used to better plan the intraoperative diagnostic study and intervention.

Ten-year technical and clinical outcomes in TransAtlantic Inter-Society Consensus II infrainguinal C/D lesions using duplex ultrasound arterial mapping as the sole imaging modality for critical lower limb ischemia

OBJECTIVE

The aim of this study was to evaluate duplex ultrasound arterial mapping (DUAM) as the sole imaging modality when planning for bypass surgery (BS) and endovascular revascularization (EvR) in patients with critical limb ischemia for TransAtlantic Inter-Society Consensus (TASC) II C/D infrainguinal lesions.

METHODS

This was a retrospective review evaluating the accuracy of DUAM as the sole imaging tool in determining patient suitability for BS vs EvR. Primary outcomes were the sensitivity and specificity of DUAM compared with intraoperative digital subtraction angiography. Secondary outcomes were procedural, hemodynamic, and clinical outcomes, amputation-free survival, and freedom from major adverse clinical events.

RESULTS

From 2002 to 2012, a total of 4783 patients with peripheral arterial disease were referred, of whom 622 critical limb ischemia patients underwent revascularization for TASC C and D lesions (EvR: n = 423; BS: n = 199). Seventy-four percent of EvR and 82% of BS were performed for TASC D (P = .218). The DUAM showed sensitivity of 97% and specificity of 98% in identifying lesions requiring intervention. Of the 520 procedures performed with DUAM alone, there was no difference regarding the number of procedures performed for occlusive or de novo lesions (EvR: 65% and 71%; BS: 87% and 78%; P = .056). Immediate clinical improvement to the Rutherford category ≤3 was 96% for EvR and 97% for BS (P = .78). Hemodynamic success was 79% for EvR and 77% for BS (P = .72). Six-year freedom from binary restenosis was 71.6% for EvR and 67.4% for BS (P = .724). Six-year freedom from target lesion revascularization was 81.1% for EvR and 70.3% for BS (P = .3571). Six-year sustained clinical improvement was 79.5% for EvR and 66.7% for BS (P = .294). Six-year amputation-free survival was 77.2% for EvR and 74.6% for BS (P = .837). There was a significant difference in risk of major adverse clinical events between EvR and BS (51% vs 70%; P = .034). Only 16.4% of patients required magnetic resonance angiography, which tended to overestimate lesions with 84% agreement with intraoperative findings. Six-year binary restenosis was 71% for DUAM procedures compared with 55% for magnetic resonance angiography procedures (P = .001), which was solely based on the prospective modality.

CONCLUSIONS

The DUAM epitomizes a minimally invasive, economically proficient modality for road mapping procedural outcome in BS and EvR. It allows for high patient turnover with procedural and clinical success without compromising hemodynamic outcome. The DUAM is superior to other available modalities as the sole preoperative imaging tool in a successful limb salvage program.

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.

Limitations of and Lessons Learned from Clinical Experience of 1,020 Duplex Arteriography

Objective: Due to the inherent risks, deficiencies and cost associated with contrast arteriography (CA), our group has been utitilizing duplex arteriography (DA) for evaluating the arteries of the lower extremity for patients undergoing lower extremity revascularization. In an effort to further explore the strengths and weaknesses of DA, we reviewed our evolving experience with DA from January 1, 1998, to January 1, 2005.

Patients and Methods: The arterial segments starting from mid-abdominal aorta to the pedal arteries were studied in cross-sectional and longitudinal planes using a variety of scanheads of 7–4, 10–5, 12–5, 5–2 and 3–2 MHz extended operative frequency range to obtain high-quality B-mode, color and power Doppler images as well as velocity spectra. In 906 patients, 1,020 duplex arteriograms were obtained. The ages ranged from 30–98 years old with a mean of 73±11 (SD) years. Fifty percent of the patients were diabetics. Indications for the examination included: tissue loss (409), rest pain (221), claudication (310), acute ischemia (74), popliteal aneurysm (45), SFA aneurysm (2), abdominal aortic aneurysms (AAA) (10) and failing bypass (55). Prior procedures had been performed in 262. DA was performed by six technologists (4 of whom are MDs). In all, 207 DA were performed intraoperatively and the remainder, preoperatively.

Results: The resultant procedures based upon DA included: bypass to the popliteal artery (262) and bypass to an infrapopliteal artery (325), endovascular procedures (363), thrombectomy (11), embolectomy (9), inflow bypass procedures to the femoral arteries (46), débridment (4), amputation (8) and no intervention (75). The areas not visualized well included: iliac (73), femoral (26), popliteal (17), and infrapopliteal (221). Additional imaging after DA was deemed necessary in 102 cases to obtain enough information to plan lower extremity revascularization. Factors associated with increased need to obtain CA included: DM ( p<.001), infrapopliteal calcification ( p<.001), older age ( p = .01) and limb threatening ischemia ( p<.001). Factors not associated with the need to obtain CA included: which technologist performed the exam, whether the technologist has a medical degree and whether the patient underwent prior revascularization.

Conclusions: In 90% of patients reviewed, DA is able to obtain the needed information to plan lower extremity revascularization. Severe tibial vessel calcification is the most common cause of an incomplete DA exam and determines when alternative imaging modalities need to be obtained.

A Prospective Feasibility Study of Duplex Ultrasound Arterial Mapping, Digital-Subtraction Angiography, and Magnetic Resonance Angiography in Management of Critical Lower Limb Ischemia by Endovascular Revascularization

Duplex ultrasound arterial mapping (DUAM) allows precise evaluation of peripheral vascular disease (PVD). However, magnetic resonance angiography (MRA) and digital-subtraction angiography (DSA) are the diagnostic tools used most frequently prior to intervention. Our aim was to compare clinical pragmatism, hemodynamic outcomes, and cost-effectiveness when using DUAM alone compared to DSA or MRA as preoperative assessment tools for endovascular revascularization (EvR) in critical lower limb ischemia (CLI). From 2002 through 2005, 465 patients were referred with PVD. Of these, 199 had CLI and 137 required EvR. Preoperative diagnostic evaluation included DUAM (n = 41), DSA (n = 50), or MRA (n = 46). EvR was aortoiliac in 27% of cases and infrainguinal in 73%. Patients were assessed at day 1, 6 weeks, 3 months, and 6 months. Composite end points were relief of rest pain, ulcer/gangrene healing, and increase in perfusion pressure, as measured by ankle-brachial index (ABI) and digital pressures. Patency by DUAM, limb salvage, morbidity, mortality, length of stay, and cost-effectiveness were compared between groups using nonparametric t-test, analysis of variance, and Kaplan-Meier analysis. The three groups were comparable in terms of age, sex, comorbidity, and Society for Vascular Surgery/International Society of Cardiovascular Surgery clinical classification. Six-month mean improvement in ABI in the DUAM group was comparable to that in the DSA group (P = 0.25) and significantly better than that in the MRA group (P < 0.05). Six-month patency rates for the DUAM group were comparable to those in the DSA group (P = 0.68, relative risk [RR] = 0.74, 95% confidence interval [CI] 0.18-2.99) and superior to that in the MRA group (P = 0.022, RR = 0.255, 95% CI 0.09-0.71). Length of hospital stay was lower in the DUAM group compared with the DSA group (P < 0.0001) and the MRA group (P = 0.0003). The cost of DUAM is lower than that of both DSA and MRA. DUAM accurately identified the total number of target lesions for revascularization; however, MRA overestimated it. Our results indicate that DUAM is outstanding when compared with other available modalities as a preoperative imaging tool in a successful EvR program. DUAM is a minimally invasive preoperative evaluation for EvR and offers precise consecutive data with patency and limb salvage rates comparable to EvR based on DSA and superior to MRA. We believe that our feasibility study has established DUAM as an economically proficient primary modality for investigating patients with CLI that significantly shortens length of hospital stay.

Preprocedural imaging: new options to reduce need for contrast angiography

In vascular surgery, the gold standard for evaluation of the lower-extremity arterial tree has long been contrast arteriography (CA). Associated risks of CA are well-documented and include severe allergic reactions, arterial injury and/or hemorrhage, and contrast-induced nephropathy. Increasingly, less-invasive techniques, with fewer inherent risks for complication, are being explored as diagnostic alternatives. Magnetic resonance angiography, computed tomography angiography, and duplex arteriography, each offer distinct advantages, though are not without limitation. This review explores the indications, advantages, and disadvantages of these newer technologies and provides a comparison to CA as a means for defining the anatomic features of patients undergoing lower-extremity revascularization. This data suggests that noninvasive imaging technologies may, in the future, play an increasingly important role in the surgical evaluation of the patient with lower-extremity ischemia.

Magnetic resonance angiography versus duplex arteriography in patients undergoing lower extremity revascularization: which is the best replacement for contrast arteriography?

OBJECTIVE

In an effort to explore alternatives to contrast material-enhanced arteriography, we compared magnetic resonance angiography (MRA) and duplex arteriography (DA) with contrast arteriography (CA) for defining anatomic features in patients undergoing lower extremity revascularization.

METHODS

From August 1, 2001, to August 1, 2002, 61 consecutive inpatients (64 limbs) with chronic lower extremity ischemia underwent CA, MRA, and DA before undergoing lower extremity revascularization procedures. The reports of these tests and images were compared prospectively, and the differences in the iliac, femoropopliteal, and infrapopliteal segments were noted. The vessels were classified as mildly diseased (<50%), moderately diseased (50%-70%), severely diseased (71%-99%), or occluded. The studies and treatment plans based on these data were compared.

RESULTS

Mean patient age was 76 +/- 10 years (SD). Indications for the procedures included gangrene (43%), ischemic ulcer (28%), rest pain (19%), severe claudication (9%), and failing bypass (1%). During this period 35 patients were ineligible for the protocol, because they could not undergo MRA (n=27) or angiography (n=8). Of the total 192 segments in the 64 patients (iliac, femoropopliteal, tibial), 17% were not able to be fully assessed with DA, and 7% with MRA. Disagreements with CA and DA were found in the iliac, femoropopliteal, and tibial segments in 0%, 7%, and 14% of cases, respectively, and between CA and MRA in 10%, 26%, and 42% of cases, respectively. Two of 9 differences (22%) between DA and CA were thought to be clinically significant, and 28 of 45 differences (62%) between MRA and CA were thought to be clinically significant.

CONCLUSIONS

A review of the data obtained in this series indicates that MRA does not yet seem to yield adequate data, at least in this highly selected population at our institution. When severe calcification is identified, CA may be necessary in patients undergoing DA.