Axillary approach for radiologic endovascular dilatation]

Basing on the analysis of 39 observed cases, the authors consider various aspects of the use of roentgenovascular dilatation by an axillary access : problems of methods, indications and contraindications; they also assess the advantages and shortcomings of the access.     

X-ray morphology of coronary arteries in patients with arterial hypertension in late periods after endovascular treatment

An association of arterial hypertension (AH) and late angiographic outcomes of endovascular interventions was studied in coronary heart disease. Forty two patients with or without AH underwent repeated coronary angiography within 2 months after the procedure. The total number of restenoses was found to be significantly greater in patients with AH than in those without it. The diameter of restenoses was significantly smaller (70.2 +/- 24.7 vs 48.2 +/- 29.2%) and their area is significantly larger (82.6 +/- 19.6 vs 66.9 +/- 28.8). Absence probability of restenosis was significantly smaller in patients with AH (7 vs 27%); at the same time there was the greatest reduction in this probability in the first 8 months following the intervention.     

Duplex scanning of brachiocephalic arteries and multislice spiral computed tomography of coronary arteries in the comprehensive evaluation of the arteries in women with rheumatoid arthritis

Comprehensive examination was made in women (mean age 49.6 +/- 7.4 years) with rheumatoid arthritis diagnosed abnormalities of brachiocephalic and coronary arteries in 86% of cases. Duplex scanning of brachiocephalic arteries revealed changes in 82% of the women. 64-section spiral computed tomography established coronary artery abnormalities in 33% of cases. There were isolated changes in the brachiocephalic arteries in 50% of the patients, a concomitant lesion of the brachiocephalic and coronary arteries in 32%, and isolated changes in the coronary arteries in 4%. A direct correlation was found between the index of coronary artery calcification and the intima-media thickness of brachiocephalic arteries.     

Diagnosis of coronary artery restenosis after radiologic endovascular dilatation]

Altogether 40 patients with stable angina of effort were investigated in a long-term period after roentgenovascular dilatation of one or two coronary arteries. Control coronarography was performed in 22 patients with lowered exercise tolerance. A reliable feature in the development of hemodynamically significant restenosis and/or "new" coronary stenosis in 11 patients was a combination of average and low exercise tolerance with its negative dynamics. For patients with I functional class, a sign of restenosis and/or "new" stenosis was the appearance of the ischemic shift of the CT-segment on ECG during bicycle testing. An efficient selection of patients resulted in increased sensitivity and specificity of noninvasive tests.     

Blood flow velocity--a constantly acting factor in dilatation of the large arteries

Acute experiments on cats have demonstrated the presence of renal artery sensitivity to the bloodstream velocity; the artery is enlarged with the blood flow increase and is narrowed with its decrease. The dilatation of the artery caused by the double increase of the blood flow (from 20 to 40 ml/min) is 23 +/- 8%. It has been established experimentally that carotid, femoral and renal arteries of cats respond to minor changes (of the order of 1 ml/min) in the volumetric velocity of the bloodstream by changing their diameters. Therefore, the arteries continuously follow the bloodstream velocity changes by changing their diameters. It may thus be concluded that the bloodstream itself is the artery dilatation factor.     

X-ray endovascular surgery of the right ovarian vein syndrome]

The author analyzes the causes of the disorders in the urodynamics and retention changes in the upper urinary routes of 43 infertile women who suffered from disordered venous reno-ovarian circulation. In chronic phlebostasis of the pelvic organs a compensatory varicose dilatation of the right ovarian vein, mediating the hemodynamic decompression of the venous bed of internal genitals, is responsible for the development of the venous compression syndrome of the right ureter. To correct the vasourethral conflict roentgenoendovascular embolization of the left ovarian vein was carried out. In the remote postembolization period 40 women presented without pain or urodynamic disorders and with normal urinalyses, in 3 women the right ureter dilatation persisted but had not progressed.     

Effects of hyperthermia on contraction and dilatation of rabbit femoral arteries

To analyze the effect of hyperthermia on thevascular response, the isometric response of isolated rabbit femoralartery segments was recorded at 37°C and hyperthermia (41 and44°C). Contraction to potassium (5 × 10³-5 × 10² M) was significantlygreater at 41 and 44 than at 37°C and increased by inhibition ofnitric oxide (NO) synthesis withN-nitro-L-arginine(L-NNA;10⁴ M) or endotheliumremoval at 37°C but not at 41 or 44°C. Norepinephrine (10⁹-10⁴M) produced a concentration-dependent contraction greater at 41 or 44 than at 37°C and not modified by endothelium removal orL-NNA at either temperature.Phenylephrine(10⁹-10⁴M) produced a contraction increased by warming to 44°C but not to41°C. The specific₂-adrenoceptor agonist BHT-920produced a weak contraction, reduced by the₁-adrenoceptor antagonist prazosin (10⁶ M) andincreased at 44°C but not at 41°C. The concentration-dependent contraction to endothelin-1 (ET-1;10¹¹-10⁷M) was increased by warming to 41 and 44°C and by endothelium removal or L-NNA at 37°C butnot at 41 or 44°C. Response to ET-1 was reduced by endothelinET_A-receptor antagonist BQ-123(10⁵ M) andET_B-receptor antagonist BQ-788(10⁵ M). In arteriesprecontracted with ET-1(10⁸-3 × 10⁸ M), relaxation tosodium nitroprusside(10⁸-10⁴M) was increased at 41 and 44°C vs. at 37°C, but that of ACh (10⁸-10⁴M) or adenosine(10⁸-10⁴M) was not different at all temperatures studied. Relaxation to ACh,but not adenosine, was reduced similarly byL-NNA at all temperaturesstudied. These results suggest hyperthermia in muscular arteries mayinhibit production of, and increase dilatation to, NO, resulting inunchanged relaxation to ACh and increased constriction to KCl and ET-1,and may increase constriction to stimulation of₁-adrenoceptors byNO-independent mechanisms.

     

Radiologic endovascular prosthesis of the renal arteries in patients with renovascular hypertension]

A high percentage of restenoses after roentgenovascular dilatation of the renal arteries laid the basis of a search for new therapeutic methods for these patients. Experiments on implantation of nitinol spiral endoprostheses showed their ability for long-term permeability of renal arteries, not causing their thrombosis and intimal spreading, destruction of formed elements of the blood, change in plasma proteins. Morphological investigations have shown rapid formation (during 14 days) of connective tissue neointima, covered on the side of the blood flow with the true vascular endothelium (ensuring a nonadhesive surface and laminar blood flow), around the coils of an endoprosthesis. This method after its experimental development started to be used in clinical practice. The authors reported the first experience in the clinical use of this method (12 patients with vasorenal hypertension). A 15-month follow-up revealed a stable antihypertensive effect in all patients.     

A comparison of balloon injury models of endovascular lesions in rat arteries

Background

Balloon injury (BI) of the rat carotid artery (CCA) is widely used to study intimal hyperplasia (IH) and decrease in lumen diameter (LD), but CCA's small diameter impedes the evaluation of endovascular therapies. Therefore, we validated BI in the aorta (AA) and iliac artery (CIA) to compare it with CCA.

Methods

Rats underwent BI or a sham procedure (control). Light microscopic evaluation was performed either directly or at 1, 2, 3, 4 and 16 weeks follow-up. The area of IH and the change in LD (LD at 16 weeks minus LD post BI) were compared.

Results

In the BI-groups the area of IH increased to 0.14 ± 0.08 mm² (CCA), 0.14 ± 0.03 mm² (CIA) and 0.12 ± 0.04 mm² (AA) at 16 weeks (NS). The LD decreased with 0.49 ± 0.07 mm (CCA), compared to 0.22 ± 0.07 mm (CIA) and 0.07 ± 0.10 mm (AA) at 16 weeks (p < 0.05). The constrictive vascular remodelling (CVR = wall circumference loss combined with a decrease in LD) was -0.17 ± 0.05 mm in CIA but absent in CCA and AA. No IH, no decrease in LD and no CVR was seen in the control groups.

Conclusions

BI resulted in: (1.) a decrease in LD in CCA due to IH, (2.) a decrease in LD in CIA due to IH and CVR, (3.) no change in LD in AA, (4.) Comparable IH development in all arteries, (5.) CCA has no vasa vasorum compared to CIA and AA, (6.) The CIA model combines good access for 2 F endovascular catheters with a decrease in LD due to IH and CVR after BI.     

Influence of vascular dimension on gender difference in flow-dependent dilatation of peripheral conduit arteries

To assess the influence of initial diameter on the gender difference in flow-dependent dilatation (FDD) of the conduit artery, we measured radial artery internal diameter (echotracking), flow (Doppler) and total blood viscosity in 24 healthy (25 +/- 0.8 yr) men and women during reactive hyperemia (RH) and during a gradual hand skin heating (SH). At baseline, mean diameter (men, 2.76 +/- 0.09 vs. women, 2.32 +/- 0.07 mm, P < 0.05), flow (men, 21 +/- 4 vs. women, 10 +/- 1 ml/min, P < 0.05), and blood viscosity (men, 4.13 +/- 0.07 vs. women, 3.92 +/- 0.13 cP, P < 0.05) were higher in men but mean shear stress (MSS) was not different between groups. During RH, the percent increase in diameter was lower in men (men, 9 +/- 1 vs. women, 13 +/- 1%, P < 0.05). This difference was suppressed after correction for baseline diameter. During SH, the increase in diameter with flow was higher in women (P < 0.01). However, the increase in MSS was higher in women because of their smaller diameter at each level of flow (P < 0.01) and there was no difference between groups for the increase in diameter at each level of MSS. These results demonstrate in a direct manner that initial diameter influences the magnitude of FDD of conduit arteries in humans by modifying the value of the arterial wall shear stress at each level of flow and support the interest of the heating method in presence of heterogeneous groups.     

Late color duplex scanning diagnosis of the areas of endovascular intervention into arteries and lower extremity shunts

The purpose of the study was to assess the areas of balloon angioplasty (BAP) and stenting of lower extremity arteries and femoral, popliteal, mainly, in situ autovenous shunts, by using color duplex scanning (CDS) in the late period of a follow-up. Materials and methods. The CDS technique could diagnose 344 (64%) areas of BAP and stenting of lower extremity arteries and shunts. The echosemiotics of complications typical of a late period was determined. Based on the specified echosemiotics of late complications, the author detected 99 (28.8%) cases of hemodynamically significant complications: BAP and stenting area stenosis (n=25 (7.3%)); BAP area restenosis (reocciusion) (n=33 (9.6%)); stent restenosis (n=19 (5.5%), arterial stenosis proximal and distal to a stent (n=17 4.9%)), and stent breakage (n=5 (1.5%)). Hemodynamically insignificant complications were revealed in 90 (26.2%) cases: intimal dissection in 16 (4.7%) cases, BAP area restenosis in 35 (10%), stent restenosis in 15 (4.4%), and arterial stenosis proximal or distal to the stent and between the stents. In the late period following BAP and stenting aortoiliac patency was 87.50 + 3.18% during a mean follow-up o 27.58 + 1.50 months. In the late period, the patency of the superficial femoral artery (SFR) was 55.41 + 14.43% during a mean follow-up of 22.60 + 2.73 months, that of the popliteal artery (PA) was 67.34 + 15.98% during a mean follow-up of 43.08 + 5.81 months, that of shin arteries was 44.96 + 19.77% during a mean follow-up of 18.76 + 2.58 months, and that of shunts, was 40.89 + 18.47% during a mean follow-up of 23.32 + 2.29 months. Thus, changes caused by the progression of the underlying disease--atherosclerosis were found in the areas of BAP and stenting of lower extremity arteries and shunts. Stent breakage may be due to "metal deterioration" and the presence of a stent in the superficial femoral artery with greatest functional load on extremity movement and flexion. The blood flow spectrum mode recording a local hemodynamic shift with > 2.0-2.5-fold linear blood flow velocity increase in the complication area was leading in the operation of an ultrasound apparatuses in the differential diagnosis of hemodynamically significant and insignificant complications. The results of good late patency of the areas of BAP and stentming of SFR and PA may be accounted for by strict criteria for selecting patients for endovascular surgery, by taking into account the indications for and contraindications to TASC (2001). In our study, 20 endovascular reinterventions (repeated balloon angioplasty, additional stenting stent balloon angioplasty) in complicated areas were performed, which maintained and prolonged the function of segments. The detection of hemodynamically insignificant complications revealed patients who need further meticulous follow-up ultrasound studies.     

X-ray endovascular embolization of the superior rectal artery: New potentialities in the surgical management of chronic hemorrhoids

Based on the concept of occurrence and development of hemorrhoids from pathologically altered groups of cavernous bodies of the anal submucosa, the author used dearterialization of hyperplastic cavernous tissue for the treatment of hemorrhoids. The treatment involves superselective catheterization and material embolization of the superior rectal artery. The characteristics of 86 remedial embolizations of the superior rectal artery and routine treatments (sclerotherapy, latex-ring ligation, cryotherapy, and surgical hemorrhoidectomy) for chronic hemorrhoids. Emphasis is placed on the advantages of embolization methods over conventional low-invasive and surgical treatment.     

Supravalvular aortic stenosis and total occlusion of the brachiocephalic trunk

In a 4-year-old girl supravalvular aortic stenosis was diagnosed by echocardiography. Her younger brother was operated on for the same heart disease one year before.     

The state of the coronary arteries during balloon dilatation following thrombolytic therapy of acute myocardial infarction (a quantitative angiographic study)

The paper is concerned with the investigation of 52 patients who received i.v. thrombolytic therapy and "delayed" balloon dilatation of the coronary arteries in the first hours of acute myocardial infarction for the first 6 days. The investigation was repeated 6 mos after the onset of disease. Analysis of the coronaroventriculography results has shown that a combined use of i.v. thrombolytic therapy and delayed balloon dilatation of the coronary arteries results in a considerable and prolonged improvement of vascular permeability attended by a significant improvement of left ventricular local function and a decrease in the number of reocclusions. Infarction-related artery restenosis after combined therapy has little influence on left ventricular function which can be probably associated with a slow rate of its formation. Infarction-related vascular reocclusion leads to marked impairment of left ventricular total and local function.     

Exercise improves the dilatation function of mesenteric arteries in postmyocardial infarction rats via a PI3K/Akt/eNOS pathway-mediated mechanism

Myocardial infarction (MI) has been shown to induce endothelial dysfunction in peripheral resistance arteries and thus increase peripheral resistance. This study was designed to investigate the underlying mechanisms of post-MI-related dysfunctional dilatation of peripheral resistance arteries and, furthermore, to examine whether exercise may restore dysfunctional dilatation of peripheral resistance arteries. Adult male Sprague-Dawley rats were divided into three groups: sham-operated, MI, and MI + exercise. Ultrastructure and relaxation function of the mesenteric arteries, as well as phosphatidylinositol-3 kinase (PI3K), Akt kinases (Akt), endothelial nitric oxide synthase (eNOS) activity, and phosphorylation of PI3K, Akt, and eNOS by ACh were determined. Post-MI rats exhibited pronounced ultrastructural changes in mesenteric artery endothelial cells and endothelial dysfunction. In addition, the activities of PI3K, Akt, and eNOS, and their phosphorylation by ACh were significantly attenuated in mesenteric arteries (P < 0.05-0.01). After 8 wk of exercise, not only did endothelial cells appeared more normal in structure, but also ameliorated post-MI-associated mesenteric arterial dysfunction, which were accompanied by elevated activities of PI3K, Akt, and eNOS, and their phosphorylation by ACh (P < 0.05-0.01). Importantly, inhibition of either PI3K or eNOS attenuated exercise-induced restoration of the dilatation function and blocked PI3K, Akt, and eNOS phosphorylation by ACh in the mesenteric arteries. These data demonstrate that MI induces dysfunctional dilation of peripheral resistance arteries by degradation of endothelial structural integrity and attenuating PI3K-Akt-eNOS signaling. Exercise may restore dilatation function of peripheral resistance arteries by protecting endothelial structural integrity and increasing PI3K-Akt-eNOS signaling cascades.