Modification of the Echogenicity of Femoral Plaques after Treatment with Total Triterpenic Fraction of Centella aslatica: A Prospective, Randomized, Placebo-Controlled Trial

The aim of this study was to evaluate whether TTFCA (total triterpenic fraction of Centella asiatica), was effective, by modulating collagen production, in a period of 12 months, increasing the echogenicity of echolucent plaques at the femoral bifurcation. Hypoechoic atherosclerotic plaques have been found to be associated with an increased evidence of cerebrovascular events. In this type of plaques stromal composition is limited as the collagen component is generally very low; the plaque composition is mainly due to lipid accumulation or thrombosis. The aim of this study was the evaluation of echogenicity of hyperechoic plaques and how it could be modified by a drug acting on the modulation of collagen synthesis. Antiplatelet agents were used in all patients; cholesterol-lowering agents were used in 34% of patients in the treatment group and in 36% in the placebo group. TTFCA was used at the dose of 60 mg thrice daily (oral tablets). Of the 60 included subjects 26 completed the study in the treatment group and 24 in the placebo group. At inclusion the average GSM in the treatment group was 14 (SD 3) and 14.3 (SD 3) in controls. At 12 months GSM was increased up to 22.8 (SD 4) in the treatment group and it was 15 (SD 3) in controls. Considering texture no significant changes were observed in controls while a qualitative increase in homogenicity was observed in the TTFCA group. Plaque size measured at the beginning and at the end of the study showed a median increase in size, in controls (23%; range 0%–44%); it was unchanged in the TTFCA group (variation 7%; 4%–26%). In conclusion in the treatment group plaques increased in echogenicity and in homogenicity; size and stenosis remained unchanged. Modulating the scarring process within echolucent plaques (low echogenicity, high echolucency, with a very low collagen/stromal component), possibly by collagen modulation, makes plaques more stable. This has been achieved and documented in the present study by an increase in the gray-scale median (plaques become more echogenic, more ‘white’). The variation in GSM is generally associated with a lower risk of wall thrombosis, rupture and embolization. These observations indicate a positive action of TTFCA on the stabilization of hypoechoic, low-density femoral plaques

Oesophagitis dissecans superficialis complicating repeated rigid oesophagoscopy and dilatation

Oesophagitis dissecans superficialis is an extremely rare and benign condition where the mucosal epithelium of the oesophagus sloughs off along the whole length of the oesophagus and is expelled as an oesophageal cast. This condition has been reported in association with various aetiological factors. We report a case of an oesophageal cast in a patient who underwent repeated oesophagoscopy and dilatation for a postcricoid web. We discuss the possible relationship between trauma to the upper oesophagus and the development of oesophagitis dissecans superficialis.

The LONFLIT4-Concorde--Sigvaris Traveno Stockings in Long Flights (EcoTraS) Study: a randomized trial

The LONFLIT1/2 studies have established that in high-risk subjects after long ( > 10 hours) flights the incidence of deep venous thrombosis (DVT) may be between 4% and 6%. The LONFLIT4 study was aimed at evaluating the control of edema and DVT prevention in low-medium-risk subjects. In this study prophylaxis of edema with specific travel stockings was evaluated in 2 separate studies involving flights lasting 7 hours and 10-12 hours. Part I. Subjects at low-medium risk for DVT were contacted; 55 subjects were excluded for several nonmedical, travel-related problems or inconvenient evaluation time; the remaining 211 were randomized into 2 groups to evaluate prophylaxis with elastic stockings in 7-8-hour, long-haul flights. The control group had no prophylaxis; the treatment group used below-knee, Sigvaris Traveno elastic stockings (Ganzoni, Switzerland, producing 12-18 mm Hg of pressure at the ankle). Color duplex scanning was used to evaluate the possible presence of DVT; edema/swelling were evaluated with a composite score including the presence of edema (with an edema tester), variations in ankle circumference and leg volumetry, subjective swelling, and discomfort (scale ranging from 0 to 10).

RESULTS

Of the 103 included subjects in the stockings group and 108 in the control group (total 211), 195 subjects completed the study. Dropouts (16) were due to low compliance or traveling and connection problems. Age, sex distribution, and risk factors distributions were comparable in the 2 groups. Stockings Group: Of 97 subjects none had DVT or superficial thromboses.

CONTROL GROUP

Of 98 subjects none had thrombosis. The level of edema at inclusion was comparable in the 2 groups of subjects. After flights there was an average score of 6.4 (1.3) in the control group, while in the stockings group the score was on average 2.4 (SD 1), 2.6 times lower than in the control group (p < 0.05). In the control group 83% of the subjects had an evident increase in ankle circumference and volume that was visible at inspection and associated with discomfort. The control of edema with stockings was clear, considering both parametric data (circumference and volume) and nonparametric (analogue scale lines) measurements. Part II. In this part of the study 200 subjects at low-medium risk for DVT were contacted; 35 subjects were excluded for several nonmedical, travel-related problems or inconvenient evaluation time; the remaining 165 were randomized into 2 groups to evaluate prevention in flights lasting between 11 and 12 hours. The control group had no prophylaxis; the treatment group used Traveno stockings. Of the 83 included subjects in the stockings group and 82 in the control group (total 165), 146 subjects completed the study. Dropouts were due to low compliance or connection problems. Age/sex distribution were comparable. Of 75 subjects completing the study in the stockings group and 71 in the control group, none had thrombosis. The average level of edema at inclusion was comparable in the 2 groups (1.1). After the flight there was a score of 8.9 (2) in controls; in the stockings group the score was 2.56 (1.3) (p < 0.05). The control of edema and swelling with stockings even after 11 hours of flight was clear, considering both parametric (circumference, volume) and nonparametric (analogue scale lines) measurements. The tolerability of the stockings was very good and there were no complaints or side effects. In conclusion Sigvaris Traveno stockings are very effective in controlling edema in long-haul flights.

[Treatment of severe intermittent claudication: ORACLE-PGE1 short term study. A randomised 40-week study. Evaluation of efficacy and costs]

BACKGROUND

The efficacy and cost of prostaglandin E1 (PGE1) in severe intermittent claudication was studied comparing a long-term protocol (LTP) with a short-term protocol (STP) in a randomised 40-week study.

METHODS

Phase 1 was a 2-week run-in phase (no treatment) for both protocols. In LTP, phase 2 was the main treatment phase. Treatment was performed with 2-hour infusions (60 micro g PGE1, 5 days each week for 4 weeks. In phase 3 (4-week interval period), PGE1 was administered twice a week (same dosage). In phase 4 (40 weeks), no PGE1 were used. In STP, phase 2 treatment was performed in two days by a 2-hour infusion (60 micro g PGE1 twice a day in 2 days). The same cycle was repeated every 4 weeks. A treadmill test was performed at inclusion, at the beginning of each phase and at the end of weeks 12, 16, 20 32 and 40. A progressive training plan (walking) and reduction in risk factors plan was used in both groups.

RESULTS

Out of the 1276 included patients 1165 completed the study (606 in LTP group; 559 in the STP). Drop-outs were 111. The two groups were comparable in distribution, risk factors and smoking. Intention-to-treat analysis indicated an increase in pain free walking distance (PFWD). The absolute and percent increase in pain-free walking distance (PFWD) was comparable in both LTP and STP groups with a significative increase in TWD at 4 weeks. At 20 and 40 weeks increase was up to 219% in the LTP and 460% in the STP group (p<0.02). Comparable results concerning PFWD were obtained in the two groups. Both treatments were well tolerated. No side effect was observed. Local effects were observed in 8.5% of the treated subjects in the LTP and 4% in the STP. The average cost of the LTP protocol was 8786 Euro. For STP the costs was 946 (10.8% of LTP). For both protocols the cost of the infusion was 24% of the total for the LTP and 35% in the STP. Therefore 75% of the cost is not drug-related.

CONCLUSIONS

In conclusion between-group-analysis favours STP considering walking distance and costs. Results indicate good efficacy and tolerability of PGE1 treatment particularly STP.

Treatment of severe intermittent claudication with pentoxifylline: a 40-week, controlled, randomized trial

The efficacy, safety, and cost of pentoxifylline (PXF) in the treatment of severe intermittent claudication were studied comparing PXF and placebo in a randomized 40-week study. A treadmill test was performed at inclusion and at the end of weeks 20 and 40. A progressive training plan and the control of risk factors (with antiplatelet treatment) were used in both groups. Of the 200 included patients, 178 completed the study: 88 in the PXF group and 90 in the placebo group. There were 22 dropouts. The two groups were comparable for age, sex distribution, and for the presence of risk factors and smoking. There was a significant increase in pain-free walking distance (PFWD) in both groups. The absolute and percent increase in PFWD was significantly greater in the PXF group (p<0.05). At 20 weeks, the increase was 360.5% in the PXF vs 252% in the placebo group. At 40 weeks, the increase was 386% in the PXF and 369% in the placebo group (p<0.02). Total walking distance (TWD) increased at 20 weeks (up to 254%) and up to 329% at 40 weeks. In the placebo groups the increase was 158% at 20 weeks and 183% at 40 weeks. The excess increase produced by PXF treatment was 30% at 20 weeks and 38% at 40 weeks (p<0.02). Unwanted effects treatment was well tolerated. No serious drug-related side effects were observed. In summary, between-group analysis favors PXF considering walking distance and costs. Results indicate good efficacy and tolerability.

Treatment of vascular inner ear disease in vascular patients with pentoxifylline: a controlled, randomized trial

The efficacy of Pentoxifylline in vascular inner ear disease (VIED) was studied comparing PXF and placebo in a 4-week study; 40 patients with vascular disease and monolateral loss of hearing, vertigo, dizziness, tinnitus (analyzed with an analogue scale line), and cochlear flow reduction were included. The aims of the study were to study the effects of PXF (1600 mg daily) in VIED considering clinical outcome and cochlear flow. Of the 20 included patients, 19 completed the study. One dropout in the placebo group was due to low compliance. Intention-to-treat analysis indicated an improvement in cochlear flow (p<0.05) and a decrease in score in both groups. The cochlear flow increase was 287.5% in the PXF group vs 168% in the placebo group (119.5% difference; p<0.02). There was a difference in score decrease (44.1% larger) in the PXF group (p<0.05).Between-group analysis favors PXF considering blood flow and symptoms. Results indicate good efficacy and tolerability of PXF in VIED.

Treatment of vascular retinal disease with pentoxifylline: a controlled, randomized trial

The aim of this study was to evaluate the effect of PXF (1800 mg daily) in patients with sudden loss of vision (SLV) in a 4-week trial, evaluating clinical outcome and retinal flow parameters. Inclusion criteria were SLV associated with thrombosis of the retinal artery; decrease in retinal blood flow (PSF: peak-systolic flow; EDF: end-diastolic flow velocity) and asymmetry between the two retinal arteries (>40%) documented by duplex scanning. All 10 included patients completed the study. The groups were comparable. No side effects were reported. A significant improvement in flow velocity (p<0.05) and a decrease in analogue score in both groups were observed. PSF increase was 550% in the PXF group vs 288% in the placebo group (262% difference). EDF increase was 400% in the PXF group vs 200% in the placebo group (200% difference). There was a significant difference in the analogue score decrease (33.3% difference larger in the PXF group; p<0.05). In conclusion, PXF treatment improved retinal flow after retinal artery occlusion better than placebo and should be considered as an important option in this condition.

Treatment of long-distance intermittent claudication with pentoxifylline: a 12-month, randomized trial

The efficacy, safety, and cost of pentoxifylline (PXF) in long-range (>400 m interval) intermittent claudication was studied comparing PXF and placebo in a 12-month study. A standardized treadmill test was performed at inclusion and at 6 and 12 months. A training plan based on walking was associated with the control of risk factor levels. Of the 194 included patients, 135 completed the study: 75 in the PXF group and 60 in the placebo group. There were 59 dropouts (due to low compliance). The authors observed a 148% increase in total walking distance (TWD) at 6 months with PXF (vs 110% with placebo; p<0.05); at 12 months, the increase was 170% with PXF (vs 131% with placebo; p<0.02). There was a 38% difference at 6 months and 39% at 12 months in favor of PXF. Treatment was well tolerated. In conclusion, PXF improved walking distance significantly better than placebo.

Short-range intermittent claudication and rest pain: microcirculatory effects of pentoxifylline in a randomized, controlled trial

The efficacy of pentoxifylline (PXF) in severe intermittent claudication was studied comparing PXF and placebo. Patients were randomized into two treatment plans: PXF (2400 mg, four 600-mg tablets daily) or equivalent placebo was administered for 10 days. The exercise protocol associated with treatment was conducted under supervision. Skin flux (RF) was measured at rest and after 1 minute of exercise (AEF = after exercise flux; 3 km/hr, 12% inclination) with laser Doppler. PO2 and PCO2 were measured at the dorsum of the foot. All 20 included patients completed the study. The two groups were comparable. In the PXF group there was a significant increase in RF, AEF, and in PO2 (p<0.05); PCO2 was decreased (p<0.05). There were also changes in the placebo group, significantly lower than those observed in the PXF group (p<0.05). In conclusion high-dose PXF treatments improved all microcirculatory parameters in subjects with short-range claudication even with a short period of treatment.

Treatment of intermittent claudication with pentoxifylline: a 12-month, randomized trial--walking distance and microcirculation

The efficacy, safety and cost of pentoxifylline (PXF) in severe intermittent claudication was studied comparing PXF and placebo in a 12-month study. A treadmill test and microcirculatory evaluation with laser Doppler flowmetry were performed at inclusion and at the end of 6 and 12 months. A physical training plan (based on walking) and reduction in risk factor levels plan was used in both groups. Of the 120 included patients, 101 completed the study: 56 in the PXF group and 45 in the placebo group. There were 19 dropouts (due to low compliance). The two groups were comparable for age, sex distribution, walking distance, and the presence of risk factors and smoking. Intention-to-treat analysis indicated a 268% increase in walking distance in the PXF group (vs 198% in the placebo group; p<0.05) at 6 months and an increase of 404% (vs 280% in the placebo group; p<0.02) at 12 months. The absolute and percent increase in pain-free walking distance (PFWD) was greater in the PXF group (p<0.05). Treatment was well tolerated. No serious drug-related side effects were observed. Microcirculatory evaluation indicated an increase in flux (p < 0.05) in the PXF group (not significant in the placebo group); the after-exercise flux (AEF) was increased (p<0.05) in both groups at 6 months but the increase in AEF was greater in the PXF group at 12 month. In conclusion, between-group analysis favors PXF considering walking distance and microcirculatory parameters. Results indicate good efficacy and tolerability.

Treatment of vascular inner ear disease with pentoxifylline: a 4-week, controlled, randomized trial

The efficacy of pentoxifylline (PXF) in vascular inner ear disease (VIED) was studied comparing PXF and placebo in a 4-week study; 60 patients with unilateral loss of hearing, vertigo, dizziness, tinnitus (analyzed with an analogue scale line), and cochlear flow reduction were included. The aim of the study was to study the effect of PXF (1800 mg/day) in VIED considering clinical outcome and cochlear flow. All patients completed the study. Improvement in cochlear flow (p<0.05) and a decrease in score in both groups were observed. The cochlear flow increase was 287.5% in the PXF group vs 168% in the placebo group (119.5% difference; p<0.02). There was a difference in score decrease (44.1% larger) in the PXF group (p<0.05). PXF was more effective considering flow and symptoms.

Intermittent claudication in diabetics: treatment with exercise and pentoxifylline--a 6-month, controlled, randomized trial

The aims of this study were to evaluate the effect of PXF (1600 mg daily) in diabetic patients with intermittent claudication. Of the 60 included patients, 53 completed the study (27 in the PXF group). There were seven dropouts. The groups were comparable for age, sex distribution, and total walking distance (TWD), and risk factors. There was an increase in TWD at 3 and 6 months in both groups (p<0.05) possibly due to exercise. However the increase (both absolute and percentage) in TWD was significantly larger in the PXF group. At 6 months, PXF produced a 292% increase in TWD (vs 180% produced by placebo) (p<0.02). The excess increase produced by PXF treatment was 112% at 6 months in comparison with placebo (p<0.02). Treatment was well tolerated. Between-group analysis favors PXF considering TWD, and results indicate good efficacy and tolerability.

Modification of the echogenicity of femoral plaques after treatment with total triterpenic fraction of Centella asiatica: a prospective, randomized, placebo-controlled trial

The aim of this study was to evaluate whether TTFCA (total triterpenic fraction of Centella asiatica), was effective, by modulating collagen production, in a period of 12 months, increasing the echogenicity of echolucent plaques at the femoral bifurcation. Hypoechoic atherosclerotic plaques have been found to be associated with an increased evidence of cerebrovascular events. In this type of plaques stromal composition is limited as the collagen component is generally very low; the plaque composition is mainly due to lipid accumulation or thrombosis. The aim of this study was the evaluation of echogenicity of hyperechoic plaques and how it could be modified by a drug acting on the modulation of collagen synthesis. Antiplatelet agents were used in all patients; cholesterol-lowering agents were used in 34% of patients in the treatment group and in 36% in the placebo group. TTFCA was used at the dose of 60 mg thrice daily (oral tablets). Of the 60 included subjects 26 completed the study in the treatment group and 24 in the placebo group. At inclusion the average GSM in the treatment group was 14 (SD 3) and 14.3 (SD 3) in controls. At 12 months GSM was increased up to 22.8 (SD 4) in the treatment group and it was 15 (SD 3) in controls. Considering texture no significant changes were observed in controls while a qualitative increase in homogenicity was observed in the TTFCA group. Plaque size measured at the beginning and at the end of the study showed a median increase in size, in controls (23%; range 0%-44%); it was unchanged in the TTFCA group (variation 7%; 4%-26%). In conclusion in the treatment group plaques increased in echogenicity and in homogenicity; size and stenosis remained unchanged. Modulating the scarring process within echolucent plaques (low echogenicity, high echolucency, with a very low collagen/stromal component), possibly by collagen modulation, makes plaques more stable. This has been achieved and documented in the present study by an increase in the gray-scale median (plaques become more echogenic, more 'white'). The variation in GSM is generally associated with a lower risk of wall thrombosis, rupture and embolization. These observations indicate a positive action of TTFCA on the stabilization of hypoechoic, low-density femoral plaques.

Carotid and femoral ultrasound morphology screening and cardiovascular events in low risk subjects: a 10-year follow-up study (the CAFES-CAVE study(1))

BACKGROUND

Subclinical arteriosclerotic lesions at the carotid and femoral bifurcations may be related to the occurrence of future cardiovascular events and of occult arteriosclerotic coronary disease. B-mode ultrasound of carotid and femoral arteriosclerotic bifurcation lesions may provide a simple screening method to select asymptomatic subjects at risk of future events.

METHODS AND RESULTS

13221 low-risk, healthy, asymptomatic individuals were included in a 10-year, prospective, follow-up based on carotid and femoral bifurcation morphology defined by B-mode ultrasound. Four classes were considered at inclusion (I: normal wall, II: wall thickening, III: non-stenosing plaques, IV: stenosing plaques). When 10000 subjects (75.6% of included subjects; 6055 males, 3945 females) completed the 10-year follow-up the study was concluded. At 10 years there were 10 events (out of 7989 subjects) in class I and 81 events in II (930 subjects; incidence=8.6%); 239 events were observed in class III (611 subjects; 39.28%) and 381 events (470 subjects; 81.06%) in IV; 61 deaths occurred in classes III+IV (1081 subjects) producing a death rate within these two classes of 5.5% (51 out of 61=81.5% in class IV). The increased event rates in classes III and IV were significant (log rank; P<0.02) in comparison with I and II.

CONCLUSIONS

Carotid and femoral morphology identified 2011 subjects (20.1% of the population) in classes II,III,IV including 98.6% of cardiovascular events and deaths in the following 10 years. A higher (P<0.05) rate of progression in classes III and IV in comparison with I and II was also observed. The ultrasound carotid and femoral classification was useful in selecting subjects at very low risk of cardiovascular events (class I), those at limited risk (class II) and a group at moderate risk (class III). A subpopulation at high risk of cardiovascular events (IV) was identified.

Endovascular stent grafting in the presence of aortic neck filling defects: early clinical experience

OBJECTIVE

Although endovascular grafts have been increasingly applied to the treatment of abdominal aortic aneurysms, their use in clinical trials is limited by well-defined anatomical exclusion criteria. One such criterion is the presence of thrombus within the infrarenal neck of an aneurysm, which is thought to (1) prevent the creation of a permanent watertight seal between the graft and the vessel wall, resulting in an endoleak; (2) contribute to stent migration; and (3) increase the risk of thromboembolism. This article summarizes our experience with endovascular abdominal aortic aneurysm exclusion in 19 patients with large aortic aneurysms, significant medical comorbidities, and apparent thrombus extending into the pararenal aortic neck.

METHODS

Of 268 patients undergoing abdominal aortic aneurysm repair, 19 (7%; 17 men; mean age, 71 years) demonstrated computed tomographic and angiographic evidence of intramural filling defects at the level of the aortic neck. In no instance did these filling defects extend above the renal arteries. Endovascular grafting was performed through use of a balloon-expandable Palmaz stent and an expanded polytetrafluoroethylene graft, delivered and deployed under fluoroscopic guidance. Follow-up at 3, 6, and 12 months and annually thereafter was performed with computed tomography and duplex ultrasound scan.

RESULTS

Spiral computed tomography and aortography revealed an irregular flow-limiting defect, occupying up to 75% of the aortic circumference, in every case. The mean aneurysm size, aortic neck diameter, and neck length before the procedure were 6.1, 2.43, and 1.4 cm, respectively; the mean aortic neck diameter after the procedure was 2.61 cm. No primary endoleaks were observed after graft insertion, and no delayed endoleaks have been detected during follow-up, which ranged from 7 to 48 months (mean, 23 months). In one patient, an asymptomatic renal artery embolus was detected on immediate follow-up computed tomography, and in another patient, an asymptomatic posterior tibial embolus occurred.

CONCLUSION

No primary endoleaks, endograft migration, or significant distal embolization were observed after endografting in patients with aortic neck thrombus. The deployment of the fenestrated portion of the stent, above the thrombus and across the renal arteries, allows for effective renal perfusion, graft fixation, and exclusion of potential mural thrombus from the circulation. The presence of aortic neck thrombus may not necessarily be a contraindication to endovascular repair in select patients.

Correlates of embolic events detected by means of transcranial Doppler in patients with carotid atheroma

PURPOSE

This study identified in patients with carotid plaques the associations of emboli detected by means of transcranial Doppler (TCD) with cerebrovascular symptoms, brain computed tomography (CT) infarction patterns, and the attributes of plaques (echodensity, degree of stenosis).

METHODS

Eighty carotid plaques (in 59 patients), producing 50% to 99% stenosis, were imaged on duplex scanning and analyzed echomorphologically in a computer with the gray scale median (GSM). The GSM facilitated the quantitative distinction of dark (low GSM) from bright (high GSM) plaques. Stenosis was assessed with duplex scanning. Emboli were counted on TCD in the ipsilateral middle cerebral artery for half an hour. The brain CT infarction patterns (pattern A: discrete subcortical and cortical; pattern B: hemodynamic, diffuse white matter lesions, basal ganglia infarctions, lacunes) and normal CT and cerebrovascular symptoms on the ipsilateral hemisphere were noted.

RESULTS

Emboli were more frequent in symptomatic (median count, 3) than asymptomatic (median count, 0) hemispheres (Mann-Whitney U test, P =.031) and in hemispheres with pattern A infarction (median count, 3.5) than in hemispheres with pattern B infarction or normal CT (median count, 0; Kruskal-Wallis test, P =.047). The increased embolic count was associated with decreased GSM (Spearman correlation, P =.045, r = -0.22), but not with high degrees of stenosis (Spearman correlation, P =.44, r = 0.086).

CONCLUSION

Emboli were more frequent in symptomatic than asymptomatic hemispheres and in CT pattern A harboring hemispheres than in CT pattern B or normal hemispheres. They were more frequent in the presence of low-plaque echodensity, but not in the presence of a high degree of stenosis. These data support the embolic nature of cerebrovascular symptomatology and CT pattern A infarctions.

PGE(1) treatment of severe intermittent claudication (short-term versus long-term, associated with exercise)--efficacy and costs in a 20-week, randomized trial

The efficacy, safety, and cost of prostaglandin E1 (PGE1) in the treatment of severe intermittent claudication was studied comparing a long-term treatment protocol (LTP) with a short-term treatment protocol (STP) in a randomized 20-week study. The study included 980 patients (883 completed the study) with an average total walking distance of 85.5 +/-10 m (range 22-119). Phase 1 was a 2-week run-in phase (no treatment) for both protocols. In LTP, phase 2 was the main treatment phase. In the LTP, treatment was performed with 2-hour infusions (60 microg PGE1, 5 days each week for 4 weeks. In phase 3 (4-week interval period) PGE1 was administered twice a week (same dosage). In phase 4 (monitoring lasting 3 months, from week 9 to 20) no drugs were used. In STP phase 2 treatment was performed in 2 days by a 2-hour infusion (first day: morning 20 microg, afternoon 40 microg; second day morning and afternoon 60 microg). The reduced dosage was used only at the first cycle (week 0) to evaluate tolerability or side effects. Full dosage (60 microg bid) was used for all other cycles. The same cycle was repeated at the beginning of weeks 4, 8, and 12. The observation period was between weeks 12 and 20. A treadmill test was performed at inclusion, at the beginning of each phase, and at the end of 20th week. A similar progressive physical training plan (based on walking) and a reduction in risk factors levels plan was used in both groups. Intention-to-treat analysis indicated an increase in walking distance, which improved at 4 weeks and at 20 weeks in the STP more than in the LTP group. At 4 weeks the variation (increase) in pain-free walking (PFWD) was 167.8% (of the initial value) in the LTP group and 185% in the STP group (p<0.05). At 4 weeks the variation (increase) in total walking distance (TWD) was 227.6% of the initial value in the LTP group and 289% in the STP group (p<0.05). At 20 weeks the increase in PFWD was 496% of the initial value in the LTP group vs 643% in the STP group (147% difference; p<0.02). The increase in TWD was 368% in the LTP group and 529% in the STP group (161% difference; p<0.02). In both groups there was a significant increase in PFWD and TWD at 4 and 20 weeks, but results obtained with STP are better considering both walking distances. No serious drug-related side effects were observed. Local, mild adverse reactions were seen in 6.3% of the treated subjects in the LTP and 3% in the STP. Average cost of LTP was 6,664 Euro; for STP the average costs was approximately 1,820 E. The cost to achieve an improvement in walking distance of 1 m was 45.8 E with the LTP and 8.5 E with the STP (18% of the LTP cost; p<0.02). For an average 100% increase in walking distance the LTP cost was 1,989 E vs. 421 E with STP (p<0.02). Between-group analysis favors STP considering walking distance and costs. Results indicate good efficacy and tolerability of PGE, treatment. With STP less time is spent in infusion and more in the exercise program. STP reduces costs, speeds rehabilitation, and may be easily used in a larger number of nonspecialized units.

The role of duplex scanning in decision making for patients with claudication

The aim of this study was to compare the accuracy of clinical decisions made for patients presenting with claudication on the basis of the ankle/brachial index (ABI) (at rest and postexercise) and duplex scanning with that made on the basis of angiograms. Fifty-six patients presenting with a history suggestive of claudication had the ABI taken at rest. Seven patients could not be exercised but their resting ABI was <0.8. Additional exercise testing was done in 49 patients; two were then excluded as there was no fall in the ABI. Thus, 54 patients were entered into the study and underwent color-flow duplex scans and angiography. A clinical decision was reached independently on the basis of the results of ABI and duplex scans as to a) conservative treatment, b) angioplasty, and c) surgery. This was compared to the decision reached on the basis of angiograms. The results show that the combined use of ABI (as a screening test) and duplex scanning can replace angiography for clinical decision making in nearly 80% of claudicants. Angiography will only be needed when duplex scans are inconclusive.

The role of duplex scanning in the diagnosis of lower limb arterial disease

Color flow duplex imaging of the iliac and femoropopliteal arteries was performed in patients undergoing angiography. The aim of the study was to determine: (1) in what percentage of patients could the iliac arteries be adequately visualized to enable a diagnosis, (2) the overall accuracy of duplex scanning in the diagnosis of arterial disease, and (3) whether there is a useful duplex criterion for the selection of patients for angioplasty. One hundred and twenty patients (79 males, 41 females; mean age 64.4 years) had duplex scans prior to angiography (2-7 days) and the results were compared. The duplex criteria of an increase in the peak systolic velocity ratio (PSVR) >2 and lesions <5 cm were used to signify hemodynamically significant stenosis (>50% narrowing), the presence of plaque and calcification in the arterial wall with alteration of PSVR and lesions >5 cm, diffuse disease, and the absence of flow on color/Doppler interrogation, occlusion. The results show that duplex scanning is a useful screening tool and may be effectively used to diagnose iliac and femoropopliteal disease in nearly 80% of patients. Angiography will be needed in those in whom duplex scanning is inconclusive, or, prior to intervention in those with disease suitable for surgical reconstruction or angioplasty, diagnosed on the basis of duplex scans.

Stent grafts in occlusive arterial disease

The use of endovascular grafts for the treatment of occlusive arterial disease continues to evolve as the sophistication of currently available devices improves with regard to device composition and delivery systems. Endovascular grafting for occlusive arterial disease is particularly useful in high-risk patients with medical comorbidities who are otherwise unfit for a major operation and conventional open repair. The early term and midterm results on the treatment of occlusive, iliac, and femoropopliteal disease have been encouraging. Further refinements in catheter technology, stent grafts, and delivery systems will further extend the use of these devices. Increasing experience from centers using different devices and long-term follow-up with regard to durability and complication will establish the role of endovascular grafts as alternatives to conventional repair.

Angioplasty of lower limb arterial stenoses under ultrasound guidance: single-center experience

PURPOSE

To examine the feasibility and utility of ultrasound-guided angioplasty for treating lower limb stenoses.

METHODS

Duplex ultrasonography was employed to guide 55 balloon dilation procedures (27 iliac, 26 superficial femoral, 1 profunda, and 1 vein graft) with the help of a special ultrasound catheter (EchoMark). Ultrasound was used to determine balloon size, monitor guidewire passage, direct the dilation, and judge procedural success. Angiography was performed prior to the procedure to confirm preprocedural ultrasound findings and afterward to compare with duplex visual and hemodynamic parameters of success (peak systolic velocity ratio < 2.0).

RESULTS

The balloon size determined from duplex measurements correlated in all cases with sizes selected based on the angiographic image. Guidewire visualization was possible in 95% of the cases. Angioplasty using ultrasound alone was feasible in 84%; inability to obtain a satisfactory image owing to vessel tortuosity, calcification, and bowel gas accounted for the failures. Against the duplex success criterion, initial completion angiograms had an accuracy of 76%, sensitivity of 76%, and specificity of 100%. The additional time for ultrasound guidance averaged 42 +/- 12 minutes for all cases.

CONCLUSIONS

Our results show that ultrasound guidance is feasible in routine clinical practice. In this series of well-selected cases of arterial stenoses, angioplasty was performed safely using ultrasound guidance alone in over 80% of the cases. Fluoroscopic monitoring is needed when ultrasound visualization is suboptimal.

Ultrasonic plaque character and outcome after lower limb angioplasty

PURPOSE

The value of ultrasonic plaque characteristics in identifying patients at "high-risk" of restenosis after percutaneous transluminal angioplasty (PTA) was studied.

METHODS

Thirty-one arterial stenoses (6 common iliac, 2 external iliac, 1 profunda femoris, 21 superficial femoral, and 1 popliteal) in 17 patients who underwent angioplasty were studied by means of duplex scanning. With a computer-based program, B-mode images were digitized and normalized using 2 reference points, blood and adventitia. A grey level of 0 to 5 was allocated for the lumen (blood) and 180 to 190 for the adventitia on a linear gray scale of 0 to 255 (0 = absolutely black; 255 = absolutely white), and the overall plaque gray-scale median (GSM) of the pixels of the plaque was used as a measure of plaque echodensity. After PTA, follow-up of stenoses was done on day 1, weekly for 8 weeks, at 3 months, 6 months, and 1 year. The total plaque thickness (sum of anterior and posterior components), minimal luminal diameter (MLD), and peak systolic velocity ratio (PSVR) were measured for all stenoses. An increase of more than 2 in the PSVR was the duplex criterion used to signify restenosis.

RESULTS

The GSM of the stenoses before angioplasty ranged from 6 to 71 (mean, 31.3 +/- 17.9); 17 stenoses had a GSM less than 25 (mean, 18.7 +/- 5.3), and 14 had a GSM more than 25 (mean, 46.4 +/- 15.8). When the GSM was less than 25, the absolute reduction in plaque thickness on day 1 post-PTA was 3.3 +/- 1.8 mm, in contrast to 1.8 +/- 1.6 mm when GSM was more than 25 (P <.03). The restenosis rate (PSVR more than 2) was 41% at 6 months and remained unchanged at 1 year. When the GSM was less than 25, restenosis occurred in 11% of lesions, in comparison with 78% when the GSM was more than 25 (P <.001).

CONCLUSION

Plaque echodensity can be used to evaluate stenoses before PTA, to predict initial success and identify a subgroup that has a high prevalence of restenosis. The identification of a group at "high-risk" of restenosis can improve the selection of patients for the procedure and also be used in prospective studies on the prevention of restenosis.

Treatment of severe intermittent claudication with PGE1--a short-term vs a long-term infusion plan--a 20 week, European randomized trial--analysis of efficacy and costs

The efficacy, safety, and cost of prostaglandin E1 (PGE1) in the treatment of severe intermittent claudication was studied by comparing a long-term treatment protocol (LTP) with a short-term treatment protocol (STP) in a randomized 20-week study. The study included 109 patients (96 completed the study) with an average total walking distance of 65.5 +/- 8 m (range 20-109). Phase 1 was a 2-week run-in phase (no treatment) for both protocols. In LTP, phase 2 was the main treatment phase. In the LTP, treatment was performed with 2-hour infusions (60 microg PGE1, 5 days each week for 4 weeks). In phase 3 (4-week interval period) PGE1 was administered twice a week (same dosage). In phase 4 (monitoring lasting 3 months, from week 9 to 20) no drugs were used. In STP, phase 2 treatment was performed in 2 days by a 2-hour infusion (1st day: morning 20 microg, afternoon 40 microg; 2nd day morning and afternoon 60 microg). The reduced dosage was used only at the first cycle (week 0) to evaluate reduced tolerability or side effects. Full dosage (60 microg b.i.d.) was used for all other cycles. The same cycle was repeated at the beginning of weeks 4, 8, and 12. The observation period was between weeks 12 and 20. A treadmill test was performed at inclusion, at the beginning of each phase, and at the end of the 20th week. A similar progressive physical training plan (based on walking) and a reduction in risk factors levels plan was used in both groups. Intention-to-treat analysis indicated an increase in walking distance, which improved at 4 weeks (101.5% in STP vs 78.3% in LTP), at 8 weeks (260.9% STP vs 107.3% LTP), and at 20 weeks (351% STP vs 242% LTP). Comparable increases in pain-free walking distance were observed in the two groups. No serious drug-related side effects were observed. Local, mild adverse reactions were seen in 7% of the treated subjects in the LTP and 5% in the STP. Average cost of LTP was approximately 6,588 ECU; for STP the average cost was approximately 1,881 ECU. The cost to achieve an improvement in walking distance of 1 m was 35.6 ECU with the LTP and 9.45 ECU with the STP (26% of the LTP cost; p<0.02). For an average 100% increase in walking distance the LTP cost was 1,937 ECU vs 550 ECU with STP (p<0.02). The cost of PGE1 (including infusion and operative costs) was 25% of the total cost for LTP (24.9% for STP). In summary, between-group-analysis favors STP, in terms of walking distance and costs. Results indicate good efficacy and tolerability of PGE1 treatment. With STP less time is spent in infusion and more can be spent in the exercise program. STP reduces costs, speeds up rehabilitation, and may be used in a larger number of nonspecialized units available to follow the protocol.

Shock waves in vascular diseases: an in-vitro study

Three human aortic specimens were used for this in-vitro study on the effects of shock waves on the arterial wall. Specimen one was from a normal (for age) healthy aorta. The full abdominal length was used (including mesenteric and renal arteries and the aortoiliac bifurcation), divided into six pieces (3 cm). The pieces were placed and fixed into degassed water. Shock waves (SW) were focused onto the aortic wall by means of a B-mode ultrasound imager. An SW generator (Minilith SL1, Storz Medical AG, Kreuzlingen, Switzerland) was used for setting of energy flux density between 0.03 and 0.5 mJ/mm2. The six aortic pieces (excluding piece 1, placed in water and left untreated as control) were treated with SW at increasing energy levels. A second aortic specimen of a man with arteriosclerotic plaques was also used and the experiment repeated at energy levels 1, 5, and 8. Another specimen of normal thoracic aorta was exposed at energy levels 1 and 8 only. Energy levels delivered onto the aortic walls were selected from theoretically destructive levels to minimal levels known not to alter vascular tissues. High-resolution ultrasounds of the aortic segments were performed with a 10 MHz high-resolution, broad-band (ATL 3000, USA) probe in water before and after SW application to detect structural changes in the wall after SW. Histology was performed with a standard hematoxylin-eosin staining.

RESULTS

The aortic pieces did not show macroscopic damages at visual examination, and at the ultrasound examination no visible changes were observed even at higher levels of SW energy. Also no effects were seen by histology. In conclusion, no damaging effects were observed, visually, by ultrasound, or by histology. At these energy levels SW appear to be safe and do not produce any damage to the aortic wall. Therefore, SW could be considered a safe, nondamaging procedure for potential treatment (ie, thrombolysis) in which vessel walls could be involved. Theoretically it is possible that functional changes could be observed in vivo including cell permeability modifications and other alterations (including changes in the potential of the cells in SW fields to modify themselves and to divide). At the energy levels described in this study SW could, theoretically be, safely used for vascular applications (ie, treating venous and arterial thrombi or in arterial plaques modification) without altering major, structural, arterial wall characteristics. Lesions or alterations that have a different density from the normal wall (thrombi or plaques) could be differently sensitive to the same dosage of SW. These differences in acoustic impedance characteristics could be used for potential treatments with SW without damaging the arterial wall.

Peter B. Samuels Award. Restenosis after percutaneous transluminal angioplasty

BACKGROUND

Determine the feasibility of studying the natural history of the atherosclerotic plaque following percutaneous transluminal angioplasty (PTA), using duplex scanning.

METHODS

Twenty-three patients with 40 stenoses (>70% and <5 cm in length) in the iliac and femoro-popliteal segments were studied by duplex scanning before PTA, on day 1, weekly for 8 weeks, and at 3 months, 6 months, and 1 year. The following measurements were made: thickness of the plaque, minimal lumen diameter (MLD), and peak systolic velocity ratio (PSVR). A PSVR >2.0 was used to indicate >50% lumen diameter reduction.

RESULTS

Thirty stenoses were available for measurement and analysis. Mean reduction in plaque thickness after angioplasty was greater in echolucent plaques (2.33 +/- 0.9 mm) than echogenic plaques (0.83 +/- 0.6 mm; P < 0.0001). Successful angioplasty (PSVR <2.0) and increase in MLD in echolucent plaques was the result of plaque compression; in echogenic plaques, of wall dilatation. The incidence of restenosis (PSVR >2.0) at 6 months was 12 of 30 (40%) remaining unchanged at 1 year; of the lesions that restenosed, 33% recurred before week 8 and the remainder between weeks 8 and 24, suggesting different mechanisms. During follow-up, all plaques showed "growth"; <2 mm in 17 (57%; group A) and >2 mm in the remaining 13 (43%; group B). The incidence of restenosis (PSVR >2.0) was 4 of 17 (23%) in group A and 8 of 13 (61%) in group B (P <0.05).

CONCLUSION

Duplex scanning provides valuable information on both luminal diameter and plaque thickness; it may be used to study the natural history of plaques following angioplasty and also the effects of therapeutic agents aimed at reducing restenosis.

Changes in energy metabolism of calf muscle in patients with intermittent claudication assessed by 31P magnetic resonance spectroscopy: a phase II open study

Energy status and metabolism in skeletal muscle of nine patients with peripheral arterial disease and suffering from intermittent claudication were evaluated using 31phosphorus magnetic resonance spectroscopy (MRS) before and after treatment for 3 months with propionyl-L-carnitine (PLC; 2 g/day p.o.). Maximum walking distance (MWD) was assessed on a standard treadmill (4 km/h, zero incline). For the group as a whole 31P MRS results did not change significantly with PLC. Although MWD increased by a mean of 36%, this change did not reach significance. However, when these variables were assessed with respect to the change in MWD, there were significant differences between those who increased MWD by > 30% (responders, R; n = 5) and those who did not (nonresponders, NR; n = 4). Compared with pretreatment values, during exercise the decrease in muscle pH in R relative to the decrease in phosphocreatine was less after PLC (p = 0.04). After exercise there was a significant inverse correlation between the changes in recovery half-time (t1/2) for phosphocreatine and in MWD (r = -0.91, p = 0.01). With PLC, Vmax increased in R (p = 0.04), but not in NR. For the patient group as a whole, the changes in Vmax and MWD correlated positively (r = 0.90, p = 0.01). This study helps to identify the changes in muscle metabolism that correlate with changes in exercise performance, and may accompany treatment with PLC.

Ultrasonic image analysis of the arterial wall in atherosclerosis

BACKGROUND

Atherosclerotic carotid artery plaques can be classified on the basis of their ultrasound appearance according to the pattern of echolucency and echogenicity. The most commonly used classification is the one described by Gray-Weale who defined 4 plaque types.

METHODS

The images of the carotid and femoral arteries of 9 healthy volunteers and 21 non-insulin dependent diabetic patients were analysed. In this study 16 atherosclerotic carotid artery plaques were imaged by B-mode high resolution ultrasonography and then subjected to analysis of the digitised images.

RESULTS

The results show that the plaques could be separated into 3 groups according to their echogenic properties. Gray-Weale plaques types 2 and 3 could not be distinguished and it is proposed that these should be classified as a single group.

CONCLUSIONS

An increased echogenicity in the intima-media complex of non-insulin dependent diabetics as well as a relationship with risk factors for the development of cardiovascular disease and with the ultrasound score could not be determined in this study.

Circadian pattern of post-surgical fatal pulmonary embolism

BACKGROUND

The circadian distribution of fatal pulmonary thromboembolism in general surgical patients is unknown.

PATIENTS AND METHODS

One hundred consecutive cases of pulmonary embolism, with reliable clinical notes and data, were studied (67 men and 33 women; mean age 71 years). Only post-surgical cases were considered in this analysis. Patients had undergone elective (78%) or emergency abdominal surgery (22%). Correct prophylaxis (according to the Windsor Consensus Statement) had been used in 12%. Cases were grouped according to the time of onset of signs and symptoms related to pulmonary embolism at one hour intervals.

RESULTS

The maximum incidence of fatal pulmonary embolism was between 7.00 a. m. and 1.00 p. m. with the highest peaks at 9.00 and 11.00 a. m. 9% of deaths) (P < 0.02). When results from this study were compared to a previous study no significant difference was observed between the distribution profile of cases from general medical wards and surgical wards.

CONCLUSION

It appears that in surgical patients there is a circadian pattern in pulmonary embolism as already documented in medical patients.

Principles of angioplasty guidance using ultrasound

Marker bands that cast dense shadow on X-ray are placed at crucial points on a catheter (for example on a peripheral angioplasty catheter on either side of the balloon) so that those parts of the catheter can be guided inside the body by X-ray. For catheter guidance by ultrasound, an ultrasound sensor in the mid-balloon region of an angioplasty catheter is integrated to the scanhead of an ultrasound scanner, via a catheter system interface (CSI). When the sensor in the catheter is imaged by the ultrasound scanner, the CSI injects a bright arrow corresponding to its position. This allows accurate catheter guidance using ultrasound. This paper describes the principles of ultrasound guidance of catheters and the initial clinical experience using this new catheter system (Echomark) in carrying out peripheral transluminal angioplasty.

The role of the distribution and anatomic extent of reflux in the development of signs and symptoms in chronic venous insufficiency

PURPOSE

The purpose of this study was to identify the distribution of venous reflux in patients with different patterns of reflux with each class.

METHODS

Color-flow duplex imaging was used to evaluate the entire venous system from groin to ankle in 465 patients (594 limbs) belonging to different clinical CVI classes (0, 1, 2, and 3). A history of previous superficial thrombophlebitis was present in five limbs and past deep vein thrombosis in 70.

RESULTS

One hundred seventy eight (30%) limbs were normal and the remaining 416 (70%) had venous incompetence. Deep reflux was present exclusively in 19 limbs (3.2%), and the perforation system alone was involved in only three limbs (0.5%). However, isolated superficial incompetence was seen in 186 limbs (31.3%) and a combination of superficial with perforating alone was involved in 45 (7.6%). Incompetence in all three systems was seen in 99 extremities (16.7%). In addition, the superficial system was involved in 390 limbs, the perforators in 151, and the deep system in 178 limbs. Only a small percentage of those in class 0 had reflux, and most of them had a single site of incompetence. In class 1 the majority of the limbs had superficial reflux (90.3%), 10.3% of the limbs had deep venous reflux, and 6.9% were competent. Reflux in the superficial system was only seen in 80.7% of the limbs in class 1 and in one fifth of the limbs in classes 2 and 3. Isolated deep or perforated incompetence was rare in all classes. Variable combined patterns of reflux were seen more often in classes 2 and 3 (p < 0.0001). In classes 2 and 3 there were no differences in the number of incompetent sites in the superficial and deep venous systems or the patterns of reflux (p > 0.1). The number of incompetent perforators in class 3 tended to be higher than that in class 2, especially in the below-knee segment, but no significant differences were seen. Distal reflux was present in the majority of the limbs in all symptomatic classes (1, 2, and 3).

CONCLUSIONS

The distribution and extent of reflux is strongly associated with clinical severity of CVI through class 2. Distal venous reflux is present in at least 80% of the symptomatic limbs. Deep venous thrombosis may not be a prerequisite for the development of skin changes or ulceration in about 75% of the limbs. Superficial venous surgery could be beneficial to at least one third of patients with skin changes or ulceration.

Calf muscle mitochondrial and glycogenolytic ATP synthesis in patients with claudication due to peripheral vascular disease analysed using 31P magnetic resonance spectroscopy

1. We set out to define abnormalities of oxidative ATP synthesis, cellular proton efflux and the efficiency of ATP usage in gastrocnemius muscle of patients with claudication due to peripheral vascular disease, using data obtained by 31P magnetic resonance spectroscopy during aerobic exercise and recovery. 2. Eleven patients with moderate claudication were studied and results were compared with 25 age-matched control subjects. Changes in pH and phosphocreatine concentration during recovery were used to calculate the maximum rate of oxidative ATP synthesis (Qmax.) and the capacity of net proton efflux. Changes in pH and phosphocreatine concentration were used to estimate rates of non-oxidative and (indirectly) oxidative ATP synthesis throughout exercise, taking account of abnormalities in proton efflux during exercise. 3. In patients with claudication, slow post-exercise phosphocreatine recovery showed a 42 +/- 9% decrease in Qmax., and the slow ADP recovery was consistent with this. pH recovery was slow, showing a 77 +/- 9% decrease in the capacity for proton efflux. Both abnormalities are compatible with a substantial reduction in muscle blood flow. 4. During exercise, increased phosphocreatine depletion and intracellular acidification were a consequence of impaired oxidative ATP synthesis and the consequent increase in non-oxidative ATP synthesis, compounded by reduced proton efflux. The acidification prevented an increase in ADP concentration which could otherwise partially compensate for the oxidative defect. All these abnormalities are compatible with a reduced muscle blood flow. 5. In addition, initial-exercise changes in pH and phosphocreatine concentration implied a 44 +/- 5% reduction in 'effective muscle mass', necessitating an ATP turnover (per litre of muscle water) twice as high for given power output as in control muscle. Some of this is probably due to a localized loss of muscle fibres, but the rest appears to reflect reduced metabolic efficiency of the muscle. This is not a direct consequence of reduced blood flow, and may be related to change in muscle fibre type.

New insights into the pathophysiologic condition of venous ulceration with color-flow duplex imaging: implications for treatment?

PURPOSE

This study was conducted to investigate the distribution of reflux in the veins adjacent to or within the venous ulcer (local) and to correlate it with the pattern of disease of the axial veins (all veins away from the ulcer area) of the affected limb.

METHODS

Forty-three ulcers in 34 legs of 33 patients were examined with color-flow duplex imaging. The veins in the area of the ulcer were scanned with a sterile technique.

RESULTS

In 17 legs (50%) there was documented past deep venous thrombosis. All of the 34 limbs had reflux in the superficial or deep axial veins either alone or in combination. Fifteen of these limbs (44%) also had perforating vein incompetence, but none had perforator incompetence alone. Six ulcers showed no evidence of reflux in the local veins when scanned through the ulcer bed despite the presence of reflux in the axial veins of the limb. In 13 limbs with 17 ulcers, either the superficial axial veins alone or the deep axial veins alone were affected (with or without associated perforator incompetence). Examination of the local veins associated with these 17 ulcers revealed a similar pattern of reflux to that seen in the axial veins in 13 cases, with the remaining 4 ulcers showing no local venous abnormality. The pattern of reflux was less predictable at the local ulcer level in limbs where both superficial and deep venous incompetence coexisted in the axial veins. Only 7 of the 26 ulcers (27%) in these limbs had similar evidence of combined superficial and deep reflux in the local ulcer veins, whereas 10 ulcers (39%) were associated with local reflux in the superficial or deep veins alone.

CONCLUSIONS

These data show that 86% (37/43) of the ulcers has some degree of reflux in the local area, the pattern of which may differ from the axial vein disease. Treatment of the local hemodynamic abnormalities may be an important factor in the healing of the ulcers and in the prevention of their recurrence.

Peripheral transluminal angioplasty under ultrasound guidance: initial clinical experience and prevalence of lower limb lesions amenable to ultrasound-guided angioplasty

PURPOSE

Currently, endovascular techniques require monitoring by radiographic imaging for accurate catheter placement. The aim of this study was first to determine the feasibility of angioplasty under ultrasound guidance using a special catheter system. Based on this outcome, the second goal was to investigate the prevalence of lesions amenable to ultrasound-guided angioplasty.

METHODS

A balloon catheter system (Echomark) has been developed, which allows accurate catheter guidance by ultrasound imaging. An ultrasound-sensitive piezoelectric sensor positioned in the middle of the balloon portion of the angioplasty catheter is interfaced to an external duplex scanner via the catheter system. The exact position of the balloon relative to the transducer is calculated and reproduced on the screen of the duplex scanner to guide balloon positioning. In the feasibility assessment of the procedure, 16 patients with disabling claudication and rest pain were selected for balloon angioplasty under ultrasound guidance based on arteriographic and hemodynamic lesion criteria of > 50% stenosis with a peak systolic velocity ration > 2.5 in a lesion < 4 cm long that could be imaged by duplex ultrasonography. A fall in the peak systolic velocity ratio below 2.0 was selected for a procedural endpoint corresponding to < 30% residual stenosis on the completion angiogram. In the second part of the study, the prevalence of stenoses amenable to ultrasound-guided angioplasty was studied in 80 patients presenting with symptoms of peripheral arterial disease.

RESULTS

In the feasibility study, 20 stenoses (5 common iliac, 6 external iliac, and 8 superficial femoral arteries and 1 graft) meeting the inclusion criteria were subjected to ultrasound-guided angioplasty with confirmation by completion angiography. The procedure was possible in 18 (90%) of the 20 stenoses. The two failures occurred in iliac arteries that could not be imaged by duplex scanning due to obesity, bowel gas, and/or vessel wall calcification. In one case, the peak systolic velocity ratio exceeded 2.5 despite a satisfactory control arteriogram; redilation was performed, and the ratio fell below 2.0. In the second part of the study, 21 (26.2%) of the 80 patients had 29 stenoses that were amenable to angioplasty according to angiographic criteria (> 50% stenosis and < 4 cm length). All these stenoses were evaluated with duplex scanning to determine their suitability for angioplasty under ultrasound guidance. Twenty-three (79%) of the 29 lesions selected for angioplasty were well visualized by duplex, and angioplasty would have been possible based on our initial clinical experience.

CONCLUSIONS

Angioplasty under ultrasound control is a feasible technique for peripheral lesions. Ultrasound allows monitoring of both anatomical and hemodynamic parameters during angioplasty and thus provides a procedural endpoint that correlates to the control angiogram. A large proportion (79%) of stenoses deemed suitable for angioplasty can be well visualized by ultrasound, but obesity, vessel wall calcification, and bowel gas may limit the ability to obtain a satisfactory ultrasound image. Ultrasound-guided angioplasty is a potentially useful procedure that warrants further investigation.

Arterial wall changes in type 2 diabetic subjects

Arterial ultrasonic appearances using high resolution ultrasound were studied in 97 subjects with Type 2 diabetes and age- and sex-matched controls. The intima-media thickness of both common carotid arteries was measured 2 cm proximal to the bifurcation and the presence or absence of plaque on both common and femoral bifurcations was recorded. The mean intima-media thickness in subjects with diabetes was 0.82 +/- 0.22 mm while in the controls 0.66 +/- 0.13 mm (p < 0.001). Multiple regression in diabetic subjects only showed no correlation between age, sex, body mass index, smoking, duration of diabetes, systolic or diastolic blood pressure, cholesterol, HDL, LDL, triglycerides, HbA1 and the common carotid artery intima-media thickness. Type 2 diabetes is associated with increased intima-media thickness which has been found to be a marker of cardiovascular events in the general population.

Ultrasonic carotid artery plaque structure and the risk of cerebral infarction on computed tomography

PURPOSE

The North American and the European Symptomatic Carotid Endarterectomy Trial investigators reported a conclusive benefit of carotid endarterectomy for patients with symptomatic 70% to 99% internal carotid artery (ICA) stenosis. However, it has been suggested that plaque structure may be an even more important factor in producing stroke than the degree of stenosis. The aim of this study was to test the hypothesis that the ultrasonic characteristics of carotid artery plaques were closely related to symptoms and to the prevalence of cerebral infarcts on computed tomography (CT).

METHODS

One hundred five carotid artery plaques causing greater than 70% stenosis in the ICA in 83 consecutive patients who underwent brain CT were characterized into four ultrasonic types: echolucent plaques, predominantly echolucent plaques, predominantly echogenic plaques, and echogenic plaques. Patients with permanent neurologic deficit were excluded.

RESULTS

There was a significant ipsilateral association between type 1 plaques and symptomatic hemispheres (p < 0.002). Twenty-six of the 105 cerebral hemispheres assessed by CT had infarcts. There was an increased incidence of brain infarcts in type I plaques (37%) compared with 18% in types II, III, and IV combined (p < 0.02).

CONCLUSION

Our results support the hypothesis that echolucent plaques are more frequently associated with symptoms and cerebral infarctions and provide further evidence that these plaques are unstable and tend to embolize. Studies on the natural history of asymptomatic carotid artery stenosis should investigate whether plaque characterization could identify a high-risk group.

Duplex controlled angioplasty

Duplex examination was carried out to assess lesions in peripheral arteries amenable to angioplasty. With the help of a special catheter, angioplasty of these lesions was performed under Duplex control. Sixteen patients presenting with claudication were examined by Duplex and 38 lesions were identified (31 stenoses, seven occlusions) and all the findings except one (vessel E1) were confirmed by subsequent angiography. Sixteen lesions were considered amenable to angioplasty and 13 lesions (in 10 patients) were selected for Duplex controlled angioplasty. A new catheter system which has a piezo-electric transducer at the centre of the balloon and integrated to a Duplex scanner via a catheter system interface, was used for the procedure. This allows the exact position of the balloon to be represented on the screen. Thirteen lesions (seven superficial femoral artery (SFA), three external iliac, two common iliac and one graft) were subjected to angioplasty under Duplex control. In one patient, the SFA was punctured directly under ultrasound control as the profunda was diseased. The guide wire was visualised in all cases and in the majority of cases, balloon size for the angioplasty was chosen by measurement of the arterial diameter by Duplex, which was also used for haemodynamic evaluation before, during and after the procedure. Eleven lesions (85%) underwent angioplasty entirely under Duplex control and additional X-ray control was needed in only two cases. In conclusion, Duplex allows the monitoring of both anatomical and haemodynamic parameters during angioplasty. It also reduces the risk of ionising radiation. Our initial experience has been encouraging as angioplasty was performed in the majority of lesions purely under Duplex control.

Characterization of symptomatic and asymptomatic carotid plaques using high-resolution real-time ultrasonography

High-resolution ultrasonography was used to classify carotid plaques into five different types in 72 patients with symptoms and in 49 without, and with stenosis of the origin of the internal carotid artery > 70 per cent. There were 72 plaques in the symptomatic group and 75 in the asymptomatic group. Type 1 plaques were uniformly echolucent, type 2 predominantly echolucent, type 3 predominantly echogenic, type 4 uniformly echogenic and type 5 consisted of plaques that could not be classified owing to heavy calcification and acoustic shadows. Type 1 plaque was found in 90 per cent of patients with symptoms and in 10 per cent of those without, type 2 plaque was found in 53 and 47 per cent, type 3 in 34 and 66 per cent, and type 4 in 5 and 95 per cent, respectively. The preponderance of echolucent plaques in symptomatic patients with stenosis > 70 per cent supports the hypothesis that this type of plaque is unstable and tends to embolize. In contrast, in patients without symptoms there is preponderance of echogenic plaques.

Ultrasonic classification of carotid plaques causing less than 60% stenosis according to ultrasound morphology and events

Carotid plaque morphology studied by ultrasound has been used to classify 3 types of bifurcation plaques, producing less than 60% stenosis on duplex scanning: Type A, the homogeneous, highly echogenic plaque; Type B, the heterogeneous (mainly echogenic, B-1 or mainly echolucent, B-2) plaque; Type C, the complex plaque with irregular surface, echogenic and/or echolucent with calcifications. One hundred asymptomatic subjects in each plaque group were included in a prospective 4-year follow-up study to evaluate clinical events and brain damage by yearly cerebral CT and MR scans. After four years 96 subjects with type A plaque, 89 with type B-1 and 67 with type C plaques completed the study. While there were no clinical events or positive cerebral scans in subjects with type A plaques there was a significantly increasing number of cerebral and vascular events in subjects with plaque B and C type with a zero mortality in the plaque A group, a 2.24% mortality in type B plaques and a significantly higher (p > 0.05) mortality (13.4%) in type C plaques. CT and MR scans revealed brain damage which had been totally asymptomatic with MR detecting a larger number of lesions. Also the number of cerebral lesions observed by CT/MR were significantly greater than the number of recorded clinical episodes. ECG stress test revealed a larger number of asymptomatic coronary disease in the C type plaques. In conclusion ultrasound plaque morphology is linked to different incidences of cerebral and cardiac events, brain damage and asymptomatic coronary disease. Also CT and MR may reveal lesions which do not cause signs or symptoms.