A double-blind, placebo-controlled study of acetylsalicylic acid (ASA) in trained runners.

Acetylsalicylic acid (ASA) is a short-acting oral inhibitor of the cyclooxygenase enzyme. Ingestion of ASA is associated with a decrease in prostaglandins, including those of the E2 series, as well as prostacyclin, and thromboxane. Consumption of therapeutic doses is associated with decreased pain and inflammation and is therefore used in a variety of inflammatory conditions. Platelet aggregation is also inhibited. Because of these observations, and the fact that platelet aggregation has been noted to be altered during exercise, the effects of ASA on exercise tolerance was of interest. We studied 17 healthy male volunteers who regularly ran as a source of exercise. During the study they ingested either 650 mg of ASA or placebo 30 min before running 2 miles (3.2 km). Outcome of the double-blind crossover study was measured by the time required to run a 2-mile distance. No differences between ASA or placebo were noted in the subjects. These data suggest that 650 mg of ASA as a premedication has little effect on exercise performance in normal endurance runners. However, whether ASA may affect pain after exercise or whether other dosage intervals would be more beneficial needs further study.     

Hemodynamic effect of percutaneous transluminal angioplasty for lower limb atherosclerosis. A study based on pulsed Doppler ultrasound flowmetry

Measurements of ankle pressure index (API) and arterial flow velocity including calculation of pulsatility index (PI) from the common femoral and pedal arteries were performed in 89 limbs of 75 patients before and after percutaneous transluminal angioplasty (PTA) (63 iliac and 26 femoropopliteal). A pulsed wave Doppler ultrasound flowmeter was used. An increase of API at rest of at least 0.15 or the absence of pressure drop after exercise following PTA was used as criteria for a hemodynamically successful angioplasty. In patients with hemodynamically successful PTA of an iliac obstruction PI increased from 4.2 to 8.6 (p less than 0.001); 91 per cent of these patients improved clinically. When iliac angioplasty was hemodynamically unsuccessful, PI remained unchanged; 11 per cent of these patients improved clinically. All limbs with hemodynamically successful PTA of a femoropopliteal obstruction improved clinically and PI increased from 3.1 to 8.7 (p less than 0.001). After hemodynamically unsuccessful femoropopliteal PTA, PI remained unchanged though 25 per cent of these patients improved clinically. These results illustrate that measurement of arterial flow velocity with calculation of PI may be a useful supplement for the functional evaluation of the effect of PTA, since symptomatic response alone may be unreliable.     

Insertion of Self-Expandable Nitinol Stents Without Previous Balloon Angioplasty Reduces Restenosis Compared with PTA Prior to Stenting

PURPOSE: To compare the development of intimal hyperplasia after deployment of a self-expanding nitinol stent with and without previous percutaneous transluminal balloon angioplasty (PTA), with the results after PTA alone. METHODS: In nine healthy pigs, the iliac arteries were divided into three groups: group 1 (n = 6 arteries) was treated with PTA; group 2 n = 6) with insertion of self-expanding stents after PTA; and group 3 (n = 6) with stent insertion without previous PTA. After 8 weeks the vessels were examined with intravascular ultrasonography, histologic examination and morphometric analysis. RESULTS: Although the injury index in group 1 (0.17 +/- 0.57) was lower (p <0.05) than in group 2 (0.26 +/- 0.06) and group 3 (0.26 +/- 0.08), PTA-treated arteries showed significantly (p <0.05) reduced mean luminal gain (0.53 +/- 2.84) compared with arteries treated with PTA prior to stenting (2.58 +/- 1.38) and compared with stenting alone (4.65 +/- 5.34). Stenting after PTA resulted in a higher (p <0.05) restenosis index (2.63 +/- 1.06) compared with stenting without PTA (1.35 +/- 0.59). Group 2 also had a significantly thicker intima p <0.05) and 83% and 74% higher intima/media ratio (p <0.05) compared with groups 1 and 3, respectively. CONCLUSION: Insertion of a self-expandable nitinol stent without previous PTA results in less intimal hyperplasia than if PTA is performed prior to stenting, suggesting that direct stenting can be used in angioplasty sessions with a favorable outcome.     

Percutaneous transluminal angioplasty for intracranial arteriosclerotic lesions

We report 17 cases of intracranial arterial stenosis treated by percutaneous transluminal angioplasty (PTA), including 9 on the intracranial internal carotid (ICA), 4 on the middle cerebral (MCA), and 4 on vertebrobasilar artery (VBA) system. All patients had ischaemic brain symptoms and stenoses of more than 60 % (calculated angiographically). We treated four patients by PTA for residual stenoses after thrombolysis for acute occlusion. We used PTA balloon catheters 2.0–3.5 mm in diameter for all procedures. As a rule, the balloon was inflated for 1 min at 6 atm. All arteries were successfully dilated (stenosis less than 50 %) except for one treated by PTA for residual MCA stenosis after thrombolysis. The patient died of a massive infarct due to MCA reocclusion caused by arterial dissection. Stenosis recurred in 4 of 16 patients. Repeat PTA was successfully carried out in these cases. However, stenosis recurred in one of these patients 3 months after PTA, but the patient is being followed because he is asymptomatic. PTA of intracranial arteries is effective, but its indications should be based strictly on potential risks, such as acute occlusion derived from arterial dissection. Received: 8 September 1997 Accepted: 6 January 1998     

Iliac and femoropopliteal vascular occlusive disease treated with flexible tantalum stents

Two hundred patients were treated with tantalum stents, 2 in the aortoiliac bifurcation, 114 in the iliac, and 84 in the femoropopliteal arteries. The indications for stenting were technically unsuccessful percutaneous transluminal angioplasty (PTA) due to arterial recoil, dissection (156 patients), or acute occlusions (15 patients). Long iliac artery occlusions (29 patients) were indications for primary stenting. Life-table analysis revealed a 3-year patency rate of 95% for stented iliac arteries, and a 1-year patency rate of 80% for stented femoropopliteal arteries. Restenosis of the stented femoropopliteal lumen was particularly frequent in stents placed for restenosis following prior PTA (7 of 12 patients), in stents placed into the distal superficial femoral and popliteal arteries (14 of 24 patients), and in stents positioned over a longer than 4-cm artery segment (9 of 16 patients). For the aortic bifurcation and iliac arteries, arterial stenting has proved to be a valuable adjunct to PTA; for femoropopliteal arteries, stenting should be restricted to acute arterial occlusions or severe residual stenosis following PTA.     

Percutaneous transluminal angioplasty of crural arteries.

In 91 patients suffering from peripheral arterial occlusive disease (Fontaine stage IIb-IV) 125 percutaneous transluminal angioplasties (PTA) of crural arteries were performed. Eighty-six of the dilatations were done in combination with a recanalization procedure (PTA, laser angioplasty, fibrinolysis) of a femoropopliteal obstruction in order to improve outflow. PTA was performed with 5 F balloon catheters 2.5 to 4 mm in diameter in combination with steerable guide wires. A primary technical success was achieved in 41 of 42 (97.6%) vessels with a single stenosis, in 64 of 68 (94.1%) vessels with 2 or more stenoses, and 9 of 15 (60%) vessels with total occlusions (overall primary success rate 91.2%). Complications included spasm (n = 3), thrombosis (n = 2), peripheral embolization (n = 2), and dissection (n = 1). None of the complications required surgical intervention. After PTA, accumulative patency rate of 71% at 2 years and 64.2% at 3 years was achieved. These results demonstrated that PTA of crural arteries is a safe procedure with an excellent primary success rate and satisfying long-term results. Thus we believe that even arterial occlusive disease in the clinical stage Fontaine IIb should be accepted as an indication for crural PTA. Furthermore, crural PTA should be used to improve reduced peripheral outflow after femoropopliteal PTA.     

血管成形术和内支架置入术对放射治疗后动脉损伤的治疗

目的评价经皮穿刺血管成形术和内支架置入术在放射治疗（简称放疗）后所致动脉疾病的治疗,及靶血管和内支架的长期支撑开放作用。方法１４例患者,因为放疗所致１８处动脉性病变,而给予血管球囊成形术治疗。并将１３个内支架置入于８例患者,分别治疗血管闭塞３例,动脉瘤１例,残存狭窄２例,多发狭窄１例,球囊成形术后再发狭窄１例。所有病例均用ＣＴ扫描和（或）多普勒超声检查,观察内支架及其靶血管内的血流情况。结果血管成形术成功治疗１４例,其中８例患者在动脉病变处置入内支架。随访８个月至５年,１１例动脉病变基本消失,血管造影示狭窄＜２０％,临床症状完全解除,３例狭窄＜３０％,临床症状改善。结论单一的血管成形术以及多技术综合运用,可有效治疗放疗所致的动脉性病变,应考虑其为动脉损伤性病变的首选治疗方法     

Endovascular treatment of atherosclerotic arterial stenoses and occlusions of the supraaortic arteries: mid-term results from a single center analysis

OBJECTIVE: To determine mid-term patency rates after endovascular treatment of supraaortic atherosclerotic arterial stenoses and occlusions using percutaneous transluminal angioplasty (PTA) and stent placement. PATIENTS AND METHODS: During a period of 83 months, 48 patients (18 female, 30 male; mean age 61 years, range 31-82 years) were included into this prospective single-center study. Fifty-five lesions of the brachial and cephalic arteries (subclavian/axillary artery n = 42, innominate artery n = 7, origin common carotid artery n = 6) were treated using PTA (n = 38), PTA plus stent (n = 11) or primary stent placement (n = 6). For anticoagulation, patients received a bolus of heparin (5000 IU) intraarterially during the intervention followed by intravenous application for 24h. At discharge, life-time application of ASA (100mg/day) was initiated. Follow-up protocol included clinical examination, colour-coded duplex ultrasound and intraarterial angiography in case of re-stenosis. RESULTS: PTA and stent placement were technically successful in all patients (100%). No major complications occurred. Of seven patients presenting with total occlusions, six were treated with stent placement. Stent implantation was also performed in all lesions located at the origin of the supraaortic arteries (n = 6). In 38 lesions, the result of PTA was satisfactory. Mean follow-up time is 22 months (range 1-83 months). During follow-up examinations, re-stenoses occurred in 10 cases (at 1 month n = 2, at 6 months n = 2, at 12 months n = 3, at 24 months n = 3). In 9 lesions, re-interventions were performed (PTA n = 7; PTA plus stent n = 2). According to Kaplan-Meier life-table analysis, cumulative primary and primary assisted patency rates are 69.5% (patients at risk n = 15; standard error 9%) and 90.6% (patients at risk n = 16; standard error 6.3%) at 20 months, respectively. CONCLUSIONS: Endovascular treatment of atherosclerotic obstructive disease in brachial and cephalic arteries is a safe procedure showing promising mid-term patency rates.     

Use of the abdominal aorta for arterial input function determination in hepatic and renal PET studies.

A method using the activity in the abdominal aorta of human and animal subjects to noninvasively estimate blood-pool input function in dynamic, abdominal PET scans is proposed and validated in this paper. Partial volume effects due to the aorta's dimensions are corrected by a semi-automated algorithm based on the transaxial resolution in the reconstructed images. The technique was validated by comparing PET measurements of abdominal aortic activity to well counter measurements of arterial blood samples (eight canine renal studies) and to PET measurements of left ventricular cavity activity (eight human hepatic studies). In renal studies, correlation analysis of the areas subtended by the two input functions yielded an essentially unitary slope (1.03 +/- 0.09), with high correlation (R2 greater than 0.95, p less than 0.001). In hepatic studies, similar values (0.99 +/- 0.03 and R2 greater than 0.85, p less than 0.001) were found. Correlation of the blood flow estimates based on the two input functions and a two-compartment model produced slopes of 1.07 +/- 0.16 and 1.03 +/- 0.07, and correlations of (R2 greater than 0.98, p less than 0.001) and (R2 greater than 0.97, p less than 0.001) for the renal and hepatic studies, respectively. We conclude that noninvasive, accurate measurements of the arterial input function by dynamic PET imaging are possible and represent a clinically viable alternative to arterial blood sampling.     

Cutting balloon percutaneous transluminal angioplasty for salvage of lower limb arterial bypass grafts: feasibility

PURPOSE: To evaluate the feasibility of cutting balloon percutaneous transluminal angioplasty (PTA) for treatment of neointimal hyperplasia in peripheral arterial bypass grafts. MATERIALS AND METHODS: Fifteen consecutive patients (six women, nine men; age range, 57-89 years; mean age, 71 years) were treated with cutting balloon PTA for 16 anastomotic stenoses after infrainguinal bypass (prosthetic grafts, seven patients; prosthetic-vein composite grafts, two; venous grafts, five; and ileofemoral stent-graft, one). Cutting balloon PTA was followed by conventional PTA to improve anastomotic diameter. Patients with stenotic vein grafts underwent cutting balloon PTA after failed conventional PTA; the other patients were treated primarily with cutting balloon PTA. Criteria for success were a lumen diameter improvement of greater than 50% or residual stenosis of 20% or less. Follow-up was performed with color duplex ultrasonographic surveillance. Patency rates and durations were calculated with Kaplan-Meier survival curves and log-rank statistics. RESULTS: Attempted conventional PTA (n = 6) prior to cutting balloon PTA was unsuccessful. Cutting balloon PTA was technically successful in 15 (94%) of 16 lesions, without clinical complications. Two local restenoses and one graft occlusion occurred between 5 and 7 months. The cumulative 6-month primary and secondary graft patency rates were 84% and 92%, respectively. At 12 and 18 months, they were 67% (95% CI: 0.34, 0.86) and 83% (95% CI: 0.48, 0.96), respectively; mean follow-up was 10.0 months. CONCLUSION: Cutting balloon PTA proved feasible for treatment of resistant peripheral arterial bypass graft stenosis, commonly caused by neointimal hyperplasia, with excellent technical success. Short-term patency with this technique appears to be superior to that with conventional PTA, and it compares well with patency of atherectomy for salvage of infrainguinal bypass grafts.     

Ioxaglate versus diatrizoate in selective pulmonary angiography. II. Cardiovascular responses

A clinical comparison of ioxaglate and diatrizoate with regard to the cardiovascular effects following selective pulmonary angiography was performed in 20 patients with normal pulmonary arterial pressure. Ioxaglate produced a significantly less marked effect on systemic blood pressure (p less than 0.001), pulmonary arterial pressure (p less than 0.001), and heart rate (p less than 0.05-0.01), as compared with diatrizoate.     

Total occlusion of iliac arteries: Results of balloon angioplasty

Fifty-six occluded iliac arteries (mean length 6.1 cm; range 1–17 cm) in 50 patients were treated by percutaneous transluminal angioplasty (PTA) or laser-assisted PTA (bilateral lesions in 6 patients). Twenty-seven patients (54%) were at high risk for surgery. Patients were followed for a maximum period of 72 months (mean 23.12 months; median 20 months). The initial success rate was 78.5% for arteries and 82% for patients. Laser-assisted PTA was attempted in 11 occluded arteries (19.64%) and was successful in 4 arteries (7.14%). Conventional PTA was successful in 71.4% of arteries including all 7 arteries for which laser-assisted PTA failed (76% of patients). PTA was unsuccessful in 12 arteries (21.43%). Urokinase was used before PTA in I artery. The effect of PTA was evident clinically by relief of rest pain (66.66%), healing of ulcer (57%), increased claudication distance or no claudication (79%) in limbs, and objectively, by improvement in ankle/arm index (AAI) (an increase of 0.16 to 0.91) and increased exercise tolerance. Continuous improvement in AAI was observed after PTA on follow-up in 9 limbs. One patient died during follow-up. On follow-up, 3 arteries were occluded, 6 showed evidence of stenosis, and 1 showed fusiform dilatation at the PTA site. The long-term results using the life-table method determined a 76% primary patency rate and 81% secondary patency rate for 72 months. The overall patency including failures was 63%. Age of the patients (p=0.0169) and hypertension (p=0.0015) significantly affected the long-term patency of the artery but not the initial success. The major complications were arterial rupture in a repeat procedure in 1 artery, axillary artery thrombosis in 1, and distal thromboembolic occlusion during PTA in 4, The long-term patency rates suggest that PTA of totally occluded iliac arteries is a safe and effective procedure and provides a long-term benefit. This paper was presented in part at the 6th Asian Oceanian Congress of Radiology, New Delhi, India, December 14–18, 1991     

Percutaneous transluminal angioplasty for transplant renal artery stenosis.

A recent report has challenged the efficacy and safety of percutaneous transluminal angioplasty (PTA) for the treatment of transplant renal artery stenosis (TRAS). From January 1983 to December 1990, 24 PTA procedures were performed for TRAS in 18 patients. The stenoses were anastomotic in two cases, in the main renal artery in 14, and segmental in eight. After PTA, the residual stenosis was less than 20% in 14 (58%), 20%-50% in four (17%), and greater than 50% in six (25%). The mean diastolic blood pressure decreased from 106 mm Hg 1 day prior to PTA to 82 mm Hg 1 day after PTA. Long-term follow-up mean diastolic blood pressure (at 2-32 months) was 93 mm Hg (P less than .01). Eleven of the 18 patients (63%) had a 10% or greater reduction in diastolic blood pressure on long-term follow-up. Major complications occurred in two patients; one groin hematoma required surgical evacuation, and one polar infarct led to hypertension that was difficult to control. No surgical revisions of the transplant renal artery were necessary. The authors' data indicate that PTA should remain the treatment of choice for nonanastomotic TRAS.     

Percutaneous transluminal angioplasty after renal transplantation

Renal artery stenosis is a frequent complication of kidney transplantation (10%). Percutaneous transluminal angioplasty (PTA) has recently been proposed as a potential therapeutic procedure. Twelve transplant patients with arterial stenosis underwent PTA. The procedure was successful in 10 cases (83.3%). Restenosis occurred in 2 patients (16.7%); both of them underwent PTA successfully. No complications occurred. A considerable improvement in glomerular filtration rate and a reduction in high blood pressure were observed in all patients after successful PTA. The authors believe PTA to be the therapy of choice in the treatment of arterial stenoses in kidney transplant patients.     

Stent placement for renal arterial stenosis: where do we stand? A meta-analysis

PURPOSE: To perform a meta-analysis of renal arterial stent placement in comparison with renal percutaneous transluminal angioplasty (PTA) in patients with renal arterial stenosis. MATERIALS AND METHODS: Studies dealing with renal arterial stent placement (14 articles; 678 patients) and renal PTA (10 articles; 644 patients) published up to August 1998 were selected. A random-effects model was used to pool the data. RESULTS: Renal arterial stent placement proved highly successful, with an initial adequate performance in 98% and major complications in 11%. The overall cure rate for hypertension was 20%, whereas hypertension was improved in 49%. Renal function improved in 30% and stabilized in 38% of patients. The restenosis rate at follow-up of 6-29 months was 17%. Stent placement had a higher technical success rate and a lower restenosis rate than did renal PTA (98% vs 77% and 17% vs 26%, respectively; P <.001). The complication rate was not different between the two treatments. The cure rate for hypertension was higher and the improvement rate for renal function was lower after stent placement than after renal PTA (20% vs 10% and 30% vs 38%, respectively; P <.001). CONCLUSION: Renal arterial stent placement is technically superior and clinically comparable to renal PTA alone.     

经皮穿刺锁骨下动脉腔内成形术

目的：评价经皮穿刺锁骨下动脉腔内成形术的效果及安全性。方法：对76例锁骨下动脉严重狭窄或完全闭塞的患者行经皮经腔血管成形术（PTA）。所有患者均有椎基底动脉和（或）上肢动脉供血不足症状。术前DSA证实锁骨下动脉狭窄69例,完全闭塞7例。行单纯球囊扩张术68例,置入支架8例。结果：PTA术后所有患者症状均消失或明显减轻。DSA、经颅多普勒超声（TCD）显示45例患者锁骨下动脉窃血被纠正,有3例出现并发症（2例穿刺部位假性动脉瘤形成,1例术中一过性眩晕暧间恢复）。经4-35个月的随访（平均29个月）,发生再狭窄3例。结论：PTA治疗锁骨下动脉严重狭窄或完全闭塞是有效和安全的,并发症低于手术治疗。     

Is percutaneous transluminal angioplasty of the femoral and popliteal arteries a justifiable procedure? A discussion in relation to 58 attempts

Angioplasty of the femoral and popliteal arteries was attempted in 58 cases over a period of 2 years. Ideal cases for treatment by percutaneous transluminal angioplasty (PTA) are those with stenoses less than 3 cm or obliterations less than 6 cm in length where the onset was between 6 months and 2 years previously. Immediate success was obtained in 50 cases (86 patients), failures usually being observed in very advanced cases. Permeability after 2 years, by actuarial calculation, was observed in 85 p. cent of cases and there were 7 complications (12 p. cent) in the 58 patients, one of whom required urgent surgery. This method represents an alternative procedure to conventional surgical shunts in young subjects, those at high surgical risk, and those with lesions in two zones. These results illustrate the value of early diagnosis, by arteriography of the lower limbs, to detect recent lesions responding best to PTA and thus to gain time in the long and painful history of this disease.     

Experimental increase in brain HIPDM uptake by hypercapnia

The 30-min brain uptake of [125I]HIPDM was measured in conscious rats--normocapnic (n = 8), hypercapnic (n = 12), and hyperoxic (n = 6). A mean 41.2% higher uptake was found in the brains of hypercapnic animals (p less than 0.01). In the three groups of rats, brain HIPDM uptake had a negative correlation with body weight (p less than 0.001) and a positive correlation with arterial pCO2 (p less than 0.01), when adjusted for body weight. These results indicate that HIPDM uptake with hypercapnia may be used as a provocative test to measure cerebral blood flow reserves.     

Decrement in postural control during mild hypobaric hypoxia

The effects of mild hypoxia on the postural control system of 39 naive subjects were examined by measuring the postural sway with a Kistler force platform, at ground level and at one of four simulated altitudes: 1,521 m (5,000 ft), 2,438 m (8,000 ft), 3,048 m (10,000 ft), or 3,658 m (12,000 ft). The total sway increased above the ground level controls for the 1,521 m, 2,438 m, and 3,048 m exposures (p less than or equal to 0.005) as did the sway at the lowest measurable frequency (p less than or equal to 0.002), but no change in sway was seen in those subjects exposed to 3,658 m as compared to ground level values. Significant interaction between altitude and exposure was observed at p less than or equal to 0.04, reflecting the definite effect at the lower altitudes and the lack of an effect at the higher altitude. The multiple comparison test indicated no difference between the responses at 1,524 m, 2,438 m, and 3,048 m. Both arterial oxygen saturation, SaO2, and the end-tidal oxygen partial pressure, PetO2, decreased in relation to the test altitudes with a statistically significant interaction between altitude and PetO2 (p less than or equal to 0.02), and SaO2 (p less than or equal to 0.005). There was no significant interaction between altitude and end-tidal carbon dioxide partial pressure (p = 0.4853). The postural control mechanisms, as an intergrative functional unit, are very sensitive to acute mild hypoxia. Arguments are advanced to indicate that intervention of compensatory mechanisms at higher altitudes may explain the recovery of postural stability at 3,658 m.     

Effect of body position on the afterload response during sustained exercise.

Hemodynamic and cardiovascular responses were studied in 80 males (age: 30 +/- 2 years) at rest, and during separate three minute trials of upright and supine isometric deadlift exercise at 30% of maximum voluntary contraction (MVC). MVC did not differ significantly between supine and upright deadlift exercise. In comparison to values at rest, both forms of isometric exercise resulted in significant increases (p less than 0.05) in heart rate, systolic blood pressure, diastolic blood pressure, mean arterial blood pressure, oxygen uptake, oxygen pulse and double product. In the upright exercise, the values obtained for all of the physiological variables were found to be significantly higher (p less than 0.05) than in the supine exercise. These findings indicate that the upright isometric deadlift produces a higher after-load than the supine maneuver, and that this response may be a good indicator of cardiovascular functioning.