Early Outcomes of Interwoven Nitinol Wire Stent Placement versus Endarterectomy for the Treatment of Atherosclerotic Disease of the Common Femoral Artery.

PURPOSE: To compare the clinical outcomes of common femoral artery (CFA) atherosclerotic disease treated with either surgical endarterectomy or an interwoven nitinol wire stent system. MATERIALS AND METHODS: A retrospective review was conducted of all patients with chronic, de novo atherosclerotic CFA disease treated with surgical endarterectomy (CFAE) or stent placement between July 2019 and March 2022. Outcome measures assessed up to 12 months after procedure included clinical improvement, primary restenosis, target vessel revascularization (TVR), major adverse limb events (MALEs), and all-cause mortality. RESULTS: Thirty-nine stents were deployed in 33 patients, and 56 CFAEs were performed in 55 patients. No differences were noted in the rate of primary patency (95.5% vs 94.4%, P = .618), TVR (2.9% vs 1.8%, P = .777), MALE (5.1% vs 5.4%, P = .949), and all-cause mortality (14.1% vs 3.6%, P = .076) between the stent and CFAE groups up to 12 months after procedure. There was greater improvement in median clinical severity in the stent group than in the CFAE group (Rutherford score change of 3.0 vs 1.5, P = .013). The median length of stay was less for the stent group (3 vs 7 days, P = .002), and there was a lower likelihood of severe or disabling adverse events in the stent group (0 vs 9 cases, P = .010). CONCLUSIONS: Patients treated with an interwoven nitinol wire stent had patency rates comparable to those treated with CFAE while having a lower incidence of severe adverse events and a shorter length of hospital stay than those who underwent CFAE.

Accuracy and Reliability of Peripheral Artery Calcium Scoring Systems Using an Intravascular Ultrasound Reference Standard.

BACKGROUND: Peripheral artery calcium scoring systems are commonly used in clinical trials to categorize calcium severity but there are little data on their accuracy and reliability. The purpose of this study was to investigate the accuracy and reliability of these systems. METHODS: Angiographic, computed tomography angiography, and intravascular ultrasound (IVUS) imaging were obtained from 47 consecutive cases sourced from a prospectively collected database of patients undergoing femoropopliteal artery endovascular intervention. Two independent blinded readers graded calcium severity using the Peripheral Arterial Calcium Scoring System, Peripheral Academic Research Consortium, and Fanelli calcium scoring systems. IVUS maximum arc of calcium and calcium length were compared between severity grades for each scoring system. The diagnostic accuracy of each scoring system for identifying severe calcium was calculated using the reference standard of an IVUS maximum calcium arc ≥ 180°. Agreement testing was performed between scoring systems and between and within observers for each system. RESULTS: IVUS identified calcium in 85% (42/47) of cases, compared to 68% (32/47) of cases with angiography. There were no differences in IVUS calcium parameters between grades of calcium for any of the scoring systems. Severe calcium was detected by IVUS in 30 cases, in 23 cases by Peripheral Arterial Calcium Scoring System (sensitivity: 73%, specificity: 33%, positive predictive value [PPV]: 83%, negative predictive value [NPV]: 22%), in 12 cases by Peripheral Academic Research Consortium (sensitivity: 42%, specificity: 83%, PPV: 92%, NPV: 25%), and in 10 cases by Fanelli (sensitivity: 39%, specificity: 100%, PPV: 100%, NPV: 27%). Agreement between scoring systems was weak to moderate (range: k = 0.55-0.74). Interobserver agreement was weak (k = 0.41-0.54) and intraobserver agreement was highly variable ranging from k = 0.41 to k = 0.92. CONCLUSIONS: The poor diagnostic accuracy and weak-to-moderate reliability of calcium scoring systems raise doubts about the use of current calcium scoring systems for use in clinical trials.

The Impact of Intravascular Ultrasound on Femoropopliteal Artery Endovascular Interventions: A Randomized Controlled Trial.

OBJECTIVES: The aim of this study was to investigate whether the addition of intravascular ultrasound (IVUS) guidance during femoropopliteal artery interventions reduced the rate of binary restenosis within 12 months compared with angiographic guidance alone. BACKGROUND: IVUS is more accurate than angiography for assessment of vessel size and disease severity. Low-level studies suggest that the use of IVUS in femoropopliteal endovascular interventions improves outcomes, but currently, no level 1 evidence exists. METHODS: This was a prospective single-center trial of 150 patients undergoing femoropopliteal endovascular intervention, randomized (1:1) to guidance by angiography or angiography and IVUS. The primary outcome measure was freedom from binary restenosis, on duplex ultrasound, within 12 months. Secondary outcomes included clinically driven target lesion revascularization, disagreements in imaging findings between modalities, and changes in treatment caused by IVUS. RESULTS: Freedom from binary restenosis at 12 months was significantly higher in the IVUS group (72.4% vs 55.4%; P = 0.008). There was no significant difference between groups for clinically directed target lesion revascularization (84.2% and 82.4%; P = 0.776). Mean vessel diameter was significantly larger with IVUS (5.60 mm vs 5.10 mm; P < 0.001). A change in treatment occurred caused by IVUS in 79% of cases. Binary restenosis was lower in the IVUS group for cases treated with drug-coated balloons (9.1% vs 37.5%; P = 0.001). CONCLUSIONS: The use of IVUS resulted in a significant reduction in the rate of restenosis after endovascular intervention. This is the first randomized controlled trial to demonstrate that IVUS improves outcomes in femoropopliteal interventions. This benefit may primarily relate to cases treated with drug-coated balloons. (Does the use of intravascular ultrasound improve outcomes of endovascular interventional procedures for peripheral vascular disease of the superficial femoral artery or popliteal artery?; ACTRN12614000006640).

Identification of micro-channels within chronic total occlusions using contrast-enhanced ultrasound.

BACKGROUND: Vascular micro-channels within chronic total occlusions (CTO) have been identified in histopathology and animal studies. They have been proposed as a potential path for achieving endovascular crossing via the lumen. There are currently no noninvasive means of imaging these structures. The aim of this study was to investigate whether contrast-enhanced ultrasound (CEUS) examination can identify micro-channels within CTO in humans. METHODS: CTO within the femoropopliteal arteries were imaged with CEUS examination in 38 patients. Segments containing micro-channels were identified and their length measured. The proportion of occlusion length containing micro-channels was assessed for each case. Micro-channel appearances including linear or tortuous configuration, crossing of occlusion caps, and connections to vasa vasorum were recorded. RESULTS: The median CTO length was 17.0 cm (interquartile range [IQR], 6.9-27.9 cm) and median age of CTO was 12 months (IQR, 6-16 months). Micro-channels were identified in 92.1% of cases (35/38). The median length within a lesion containing micro-channels was 6.4 cm (IQR, 2.4-14.3 cm) and median proportion of CTO containing micro-channels was 47.9% (IQR, 1.7%-28.5%). A linear micro-channel configuration was seen in 84.2% of cases and a tortuous configuration was seen in 57.9% of cases. Micro-channel connections through the cap were seen in 50% (19/38 cases) and connections to the vasa vasorum in 71.1% (27/38 cases). No association was found between the proportion of each lesion containing micro-channels and CTO age, lesion length or calcification severity. There were no adverse effects related to contrast use. CONCLUSIONS: CEUS can be used to detect micro-channels in CTO in human femoropopliteal arteries. This imaging technique is safe and minimally invasive and may represent a practical method for selection of occlusion crossing method. Further work is required to determine whether identification of micro-channels can be used to improve treatment decision-making and provide a better understanding of the natural history of femoropopliteal CTO.

The effect of supervised exercise therapy for intermittent claudication on lower limb lean mass.

OBJECTIVE: Supervised exercise is currently recommended for the first-line treatment of intermittent claudication based on improvement in walking capacity. However, the promotion of skeletal muscle atrophy by repetitive ischemia-reperfusion caused by treadmill-based programs remains a concern. Because preservation of skeletal muscle mass (SMM) and lean mass (LM) is integral to functional capacity and longevity, this study measured the effect of standard treadmill-based supervised exercise on SMM and regional lower limb LM in patients with intermittent claudication. METHODS: Patients with calf claudication caused by infrainguinal peripheral artery disease underwent whole-body dual-energy X-ray absorptiometry scanning before and after completion of a 12-week supervised treadmill exercise program. Total body SMM and lower limb LM were measured according to anatomical regions of the lower limb (thigh vs calf) and side of symptoms. Walking performance was assessed using pain-free walking distance and 6-minute walking distance tests. RESULTS: Thirty-six patients with calf claudication completed exercise training and dual-energy X-ray absorptiometry scanning, allowing analysis of 55 symptomatic and 17 asymptomatic lower limbs. No difference in total body SMM (P = .41) or LM of symptomatic (P = .53) or asymptomatic calves (P = .59) was detected after the program. In contrast, a significant decrease in LM was observed in symptomatic (P = .04) and asymptomatic thighs (P = .005). Pain-free walking distance (P = .001) and the 6-minute walking distance both improved significantly (P = .004) but were not associated with changes in LM. CONCLUSIONS: Twelve weeks of standard treadmill-training for intermittent calf claudication did not result in loss of calf LM; however, a significant decrease in bilateral thigh LM was observed, even in patients with unilateral symptoms. Further research on optimum exercise modalities and end points are required to determine the pathophysiology and effects of these changes on function and survival.

A Comparison of Measures of Endothelial Function in Patients with Peripheral Arterial Disease and Age and Gender Matched Controls.

This study compared flow-mediated dilatation (FMD), peripheral artery tonometry (PAT), and serum nitric oxide (NO) measures of endothelial function in patients with peripheral artery disease (PAD) against age/gender matched controls. 25 patients (mean age: 72.4 years, M : F 18 : 7) with established PAD and an age/gender matched group of 25 healthy controls (mean age: 72.4 years, M : F 18 : 7) were studied. Endothelial function was measured using the % FMD, reactive hyperemia index (RHI) using PAT and serum NO (µmol). Difference for each method between PAD and control patients and correlation between the methods were investigated. FMD and RHI were lower in patients with PAD (median FMD for PAD = 2.16% versus control = 3.77%, p = 0.034 and median RHI in PAD = 1.64 versus control = 1.92, p = 0.005). NO levels were not significantly different between the groups (PAD median = 7.70 µmol, control median = 13.05 µmol, p = 0.662). These results were obtained in elderly patients and cannot be extrapolated to younger individuals. FMD and PAT both demonstrated a lower hyperaemic response in patients with PAD; however, FMD results in PAD patients were unequivocally reduced whereas half the PAD patients had RHI values above the established threshold for endothelial dysfunction. This suggests that FMD is a more appropriate method for the measurement of NO-mediated endothelial function.

The impact of different supervised exercise regimens on endothelial function in patients with intermittent claudication.

BACKGROUND AND OBJECTIVES: The impact of supervised exercise training on endothelial function in patients with intermittent claudication is unclear. This study assesses the impact of treadmill-based supervised exercise training alone or in combination with resistance training on pain free walking distance, flow-mediated dilatation, reactive hyperaemia index, nitric oxide and asymmetric dimethylarginine. METHODS: Thirty-five patients with intermittent claudication were randomised to 12 weeks of treadmill-only supervised exercise training (Group 1) or a combination of treadmill and lower-limb resistance supervised exercise training (Group 2). Pain free walking distance was assessed by six-minute walk test. Endothelial function was assessed by brachial artery flow-mediated dilatation, reactive hyperaemia index and serum analysis of asymmetric dimethylarginine and nitric oxide. RESULTS: Pain free walking distance improved within Group 1 (160 m to 204 m, p = 0.03) but not Group 2 (181 m to 188 m, p = 0.82), no between group difference. No significant change in flow-mediated dilatation or reactive hyperaemia index in either group. Nitric oxide decreased in Group 1 (15.0 µmol/L to 8.3 µmol/L, p = 0.003) but not Group 2 (11.2 µmol/L to 9.1 µmol/L, p = 0.14), p = 0.07 between groups. Asymmetric dimethylarginine decreased in Group 2 (0.61 µmol/L to 0.56 µmol/L, p = 0.03) but not Group 1 (0.58 µmol/l to 0.58 µmol/L, p = 0.776), no between group difference. CONCLUSION: Supervised exercise training does not improve endothelial function as measured by flow-mediated dilatation, reactive hyperaemia index and nitric oxide bioavailability.

Fluctuating fetal or neonatal renal pelvis: marker of high-grade vesicoureteral reflux.

Fetal renal pelvic dilatation is a predictor of vesicoureteral reflux (VUR), but has low specificity. The aim of this study was to determine the clinical significance of fluctuating size of the renal pelvis on sonography, particularly in relationship to VUR. We prospectively recorded fetal renal pelvic diameter >/=4 mm in 1,092 fetuses (692 boys), from May 1989 to December 1995, with a minimum follow-up of 7 years. Fluctuation, defined as size of renal pelvis changing by more than 4 mm during the course of obstetric (23), postnatal (128), and both pre- and postnatal (7) renal sonograms, was recorded prospectively in 159 (117 boys). Of the 1,092, 849 (593 boys) had a voiding cystourethrogram at a mean age of 7 weeks (range 3-20 weeks). Of the 31 (16 girls) with high-grade VUR, fluctuation was observed in 20 (9 girls). Fluctuation was strongly associated with high-grade VUR (odds ratio 11.1, P=0.0000003) and with renal damage (sensitivity 61%, positive predictive value 31%). Primary high-grade VUR was persistent, seen equally in boys and girls, and required surgery in the majority. Fluctuation was associated with renal duplication anomalies ( P=0.00009) and megaureter ( P<0.00000001). Fluctuation of the renal pelvis on sonography is a marker for persistent high-grade VUR and renal damage in girls and boys.