Intra-arterial Pressure Measurements Research Articles

Can exercise prevent preeclampsia?

Can exercise prevent preeclampsia?

THE “ULTRASONOGRAPHIC OSLER'S MANEUVER” AND ITS USE IN IDENTIFYING PATIENTS WITH PSEUDOHYPERTENSION

THE “ULTRASONOGRAPHIC OSLER'S MANEUVER” AND ITS USE IN IDENTIFYING PATIENTS WITH PSEUDOHYPERTENSION

Best Duplex-Sonographic Criteria for the Assessment of Renal Artery Stenosis - Correlation with Intra- Arterial Pressure Gradient

Colour coded duplex sonography (DS) is widely used for the assessment of renal artery stenosis (RAS). Different criteria have been specified for the detection of significant RAS. The aim of our study was to compare routinely used DS criteria, both with intra-arterial pressure gradients and arteriographic degree of stenosis, and to validate different cut-off points of these DS criteria for the assessment of haemodynamically significant RAS. We retrospectively analysed forty-nine patients (median age 67 years, 29 male) with RAS documented by duplex sonography, referred for renal arterial subtraction arteriography and intra-arterial pressure measurement (93 renal arteries). DS measurement of peak systolic velocity (PSV) in the main renal artery, the renal/aortal velocity ratio (RAR) and the side-to-side differences of the intrarenal resistive indices (DeltaRI) were correlated to intra-arterial pressure measurements and arteriographic degree of stenosis. Receiver operating characteristics (ROC) were used to determine the best cut-off value of DS criteria. 39 (41 %) renal arteries had normal findings or non significant stenosis < 50 %, 23 (25 %) had a diameter reduction between 50 % and 69 %, and 31 (33 %) > or = 70 %. The systolic pressure gradient showed good correlation with the arteriographic degree of RAS (r = 0.77, p < 0.001) and the PSV measured by duplex sonography (r = 0.67, p < 0.001). Mean systolic pressure gradient was 24 mmHg at 50 % stenosis and 23 mmHg at PSV of 200 cm/sec. A PSV of > or = 200 cm/sec provided a sensitivity of 92 % and specificity of 81 % for detecting RAS of > or = 50 %. Similar results were found for RAR > or = 2.5 with a sensitivity of 92 % and specificity of 79 %. These cut-off values have a negative predictive value of 100 % for excluding high-grade RAS of > or = 70 %. A DeltaRI of > or =0.05 has low sensitivity of 31 %, but a high specificity of 97 % for detecting RAS of > or = 50 %. DS measurements and the severity of arteriographic diameter reduction correlate well with systolic pressure gradients. Clinically expedient DS criteria for detecting RAS of > or = 50 % are a PSV of > or = 200 cm/sec or a RAR of > or =2.5. These criteria allow reliable exclusion of severe RAS of > or = 70 %.

Value of duplex scanning compared with angiography and pressure measurement in the assessment of aortoiliac arterial lesions

To detect haemodynamically significant lesions in the aortoiliac arteries, invasive tests such as angiography and intra-arterial pressure measurement (IAPM) are considered valuable diagnostic tools. The value of duplex scanning as a direct non-invasive examination technique was prospectively compared with intra-arterial digital subtraction angiography (IADSA) and IAPM at rest, and after the administration of papaverine in 60 patients. Excellent agreement, as assessed by the kappa statistic, was shown between duplex scanning and IADSA (kappa = 0.81). A fair agreement was shown between duplex scanning and IAPM (kappa = 0.63), and between IADSA and IAPM (kappa = 0.63). Duplex scanning and IADSA both missed some less haemodynamically critical lesions if IAPM was considered the 'gold standard'. It is concluded that duplex scanning detects haemodynamically significant lesions as effectively as angiography and so may be considered a new and valuable diagnostic tool. IAPM remains necessary to detect some lesions of borderline haemodynamic significance. However, with future developments, duplex scanning has the potential to replace the need even for IAPM.

Criteria from intra-arterial femoral artery pressure measurements combined with reactive hyperaemia to assess the aorto-iliac segment; A prospective study

Direct femoral artery blood pressure measurements combined with reactive hyperaemia (FAP study) were performed on 50 extremities (45 patients) with multilevel arterial occlusive disease of the lower extremities. In a previous retrospective study we established criteria for detection of significant aorto-iliac occlusive disease. These criteria were used in a prospective way in this study. Twenty-seven extremities were subjected to a proximal and 23 extremities to a distal reconstruction. The half-year postoperative results were evaluated. The criteria used were 86 per cent sensitive, 100 per cent specific and 93 per cent accurate in relation to predicting the postoperative haemodynamic result. The positive predictive value was 100 per cent and the negative predictive value 89 per cent. The criteria are presented and compared with data from the literature. It is concluded that FAP studies are a simple and excellent way to assess the aorto-iliac segment and to predict the outcome of a reconstruction in multilevel arterial occlusive disease.

Noninvasive Techniques to Detect Subcritical Iliac Artery Stenoses

Severe iliac stenoses in patients with peripheral arterial occlusive disease (PAOD) can be accurately detected bymeans of angiography or duplex scanning. Unfortunately, sub-critical, or borderline, iliac artery stenoses (i.e. with diameter reduction between severe and mild) are missed in approximately 25% of the cases by both angiography and duplex scanning. Since, most of the patients with PAOD are known to have multi-level disease, involving both iliac and femoro-popliteal segments, it is important for the therapeutic management to assess whether iliac stenoses with a sub-critical diameter reduction are of haemodynamic significance and can be regarded as causal to the patient’s complaints. Intra-arterial pressure measurement (IAPM) before and after the administration of a vasodilating agent is the reference diagnostic tool for the haemodynamic assessment of lesions in the iliac arteries. Here, we focus on the noninvasive haemodynamic approach in the detection of sub-critical iliac artery stenoses and discuss the potential of hyperaemic duplex scanning and phase-contrast MRI.

Clinical and Angiographic Outcome After Interventional Treatment of the Iliac Arteries with a New CarboFilm™ Coated Stent: Preliminary Results

To evaluate the handling, the procedural success rate and the six-month outcome of a new Carbofilm coated balloon-expandable stent in iliac artery lesions. In a prospective study, 46 stenoses and 2 occlusions of the iliac arteries were primarily stented in 30 patients with the Isthmus CarboStent (Sorin Biomedica Cardio S.p. A., Saluggia, Italy). The ankle-brachial index (ABI) at rest was determined before intervention and at the six-month follow-up visit. Iliac angiography, including intraarterial pressure measurement, was performed before intervention, post-procedurally and at the follow-up visit. All lesions were treated with procedural success. The mean degree of all stenoses was 73.9 % +/- 14.6 before and 2.4 % +/- 8.2 after intervention. The mean pressure gradient was 15.6 mm Hg +/- 10.1 before and 2.5 mm Hg +/- 2.7 after treatment. No or only a mild restenosis developed in 27 patients. The mean ABI increased from 0.64 +/- 0.21 to 0.86 +/- 0.33 and the mean pressure gradient was 2.7 mm Hg +/- 5.4 at the six-month visit. The six-month patency rate was 97.9 %. Three patients showed acute stent thrombosis due to an insufficient postprocedural antiplatelet regimen. The Isthmus CarboStent is a safe and easy to handle balloon-expandable stent for interventional therapy of iliac artery lesions. The six-month patency rate is good. Despite its Carbofilm coating, postprocedural antiplatelet therapy is necessary.

The effect of sympathetic stimulation on proximal brachial artery mechanics in humans--differential behaviour within the length of the brachial artery?

The mechanical properties of arteries play a major role in the regulation of blood pressure and cardiac performance. The effect of sympathetic stimulation on the mechanical properties of the proximal brachial artery was analysed in 18 healthy volunteers, nine young (25 +/- 2 years) and nine elderly (69 +/- 2 years). A non-invasive ultrasonic echo-tracking system for measurement of systolic/diastolic variation of the proximal brachial artery diameter in combination with intra-arterial pressure measurements was used to determine wall mechanics. The pressure-diameter (P-D) relationship, distensibility coefficient (DC), compliance coefficient (CC) and stiffness(beta) were obtained at rest and during sympathetic stimulation induced by lower body negative pressure (LBNP). The peripheral vascular resistance increased by 100 and 72%, respectively in the young and elderly during LBNP (P < 0.001). Simultaneously, the mechanical properties of the proximal brachial artery remained unaltered, as estimated from both P-D relationship and stiffness in young (beta-index rest: 5.2 +/- 0.9, LBNP: 5.5 +/- 1.3, NS) as well as elderly (beta-index rest: 13.6 +/- 4.6, LBNP: 16.1 +/- 4.7, NS). LBNP-induced sympathetic activation does not change proximal brachial artery mechanics, in contrast to earlier reports on the muscular distal brachial artery. This may imply that the transition between elastic and muscular artery behaviour is within the length of the brachial artery, where the site of transition from elastic to muscular wall structure needs to be specified in future studies.

Improved assessment of the hemodynamic significance of borderline iliac stenoses with use of hyperemic duplex scanning

Objective: To improve the assessment of the hemodynamic significance of borderline iliac stenoses (stenosis with a peak systolic velocity [PSV] ratio between 1.5 and 3.5) by means of hyperemic duplex scanning. The duplex ultrasound parameter—absolute increase in PSV across the stenosis after exercise (ΔPSV e)—was studied prospectively. Patients and Methods: Fifty-eight legs in 53 consecutive patients with symptomatic arterial obstructive disease with borderline iliac stenosis were studied prospectively. Ultrasound velocity data collected after exercise on a bicycle ergometer at 2 W/kg during 2 minutes were judged against the assessment of the hemodynamic significance by means of intraarterial pressure measurement, before and after the administration of 50 mg papaverine. Results: On the basis of receiver operating characteristic curves traced for 43 iliac stenoses in 39 patients who finished the exercise, ΔPSV e ≥1.4 m/s had optimal sensitivity of 93% (95% confidence interval [CI], .77-.99), specificity of 87% (95% CI, .60-.98), positive predictive value of 93% (95% CI, .77-.99) and negative predictive value of 87% (95% CI, .60-.98). Conclusions: The results of this study show that ΔPSV e with a cutoff value of 1.4 m/s in combination with the PSV ratio improves the assessment of the hemodynamic significance of borderline iliac artery stenoses if the patient can accomplish the workload. (J Vasc Surg 2002;36:575-80.)

Steal affecting the central nervous system.

Steal is a pathophysiological process in which increased blood flow through a low-resistance vascular bed is sufficient to divert flow away from a region of the central nervous system. Three disease states in which steal may cause neurological deficits due to central nervous system ischemia are reviewed. Subclavian steal occurs when stenosis of the subclavian artery proximal to the vertebral origin causes retrograde flow in the left vertebral artery. Patients with anatomic subclavian steal usually do not develop neurological symptoms but may rarely present with posterior circulation ischemia. Arteriovenous malformations alter cerebral blood flow patterns and regional perfusion pressure. It has been hypothesized that cerebral arteriovenous malformations may cause neurological deficits due to steal and that these deficits may be cured with arteriovenous malformation treatment. Intra-arterial pressure measurements and transcranial velocity studies show regional hemodynamic alterations. However, these changes have not been correlated with presenting symptoms. Evidence from single-photon emission computed tomography does suggest a relationship between regional hypoperfusion and neurological deficits. Coarctation of the aorta may divert flow from the spinal cord circulation through intercostal arteries distal to the stenosis. This is a possible but unproven mechanism of myelopathology. Steal syndromes may be amenable to treatment by open surgical or endovascular approaches. Experimental studies of the pathophysiology of steal are strengthened by precise definitions of the measured parameters and innovative applications of technology.

Diagnostic evaluation of aortoiliac occlusive disease: when is a lesion significant?

Many methods, both invasive and noninvasive, are currently available for evaluation of the aortoiliac arterial system before and after percutaneous intervention. Optimal evaluation requires a combination of morphologic and functional information to localize, characterize, and assess the hemodynamic significance of any primary or residual arterial narrowing. In this article, we consider these methods, with an emphasis on the combination of contrast arteriography and intra-arterial pressure measurements in current management of aortoiliac disease.

Noninvasive evaluation before and after percutaneous therapy of iliac artery stenoses: The value of the Bernoulli-predicted pressure gradient

Purpose: The purpose of this study was to assess the value of the Bernoulli-predicted pressure gradient in the noninvasive evaluation of patients undergoing iliac percutaneous transluminal angioplasty (PTA) or stent placement with the use of intra-arterial pressure measurements as the standard of reference. Methods: Stent placement or PTA was performed in 261 patients with intermittent claudication caused by iliac artery stenoses (333 procedures). Intra-arterial translesional pressure gradients were recorded before and after each procedure. Hemodynamic success was defined as a postprocedural mean pressure gradient less than or equal to 10 mm Hg at rest and during vasodilatation. Before and after intervention, the following noninvasive parameters were determined: the Bernoulli-predicted pressure gradient, the peak systolic velocity ratio, and the ankle-brachial pressure index. Results: Before treatment, both the intra-arterial–measured pressure gradients and the Bernoulli-predicted gradients indicated hemodynamic significance of the iliac artery stenoses. After treatment, both methods indicated significant improvement of the translesional pressure gradient (P <.0001). However, the correlation between the intra-arterially measured pressure gradient and the Bernoulli-predicted gradient of iliac artery stenoses was low (Pearson's r = 0.27). None of the three investigated noninvasive methods could differentiate an optimal PTA or stent result from a suboptimal result, as assessed by intra-arterial pressure measurements. Conclusions: The disappointing correlation among the duplex velocity data, whether expressed as pressure gradient or as a peak systolic velocity ratio, and the actually measured pressure gradient might be caused by errors in pressure or velocity measurements or the different circumstances in which the pressure or velocity measurements were performed. Residual pressure gradients after iliac PTA or stent placement assessed with intra-arterial pressure measurements could not be assessed with the investigated noninvasive methods. (J Vasc Surg 2000;32:153-9.)

Gadolinium-enhanced Magnetic Resonance Angiography, Digital Subtraction Angiography and Duplex of the Iliac Arteries Compared with Intra-arterial Pressure Gradient Measurements

Purpose: to compare gadolinium-enhanced magnetic resonance angiography (Gd-MRA), digital subtraction angiography (DSA) and duplex of the iliac arteries with intra-arterial pressure gradient measurement as the reference method. Materials and methods: Gd-MRA, DSA and duplex examinations of the iliac arteries were performed in 30 patients (60 arteries) with lower-limb arterial occlusive disease. In 29 arteries, pressure measurements were made (n=25) or the artery was found to be occluded on catheterisation (n=4). An aortofemoral peak systolic pressure gradient of 20 mmHg or more was regarded as haemodynamically significant. Stenoses with a diameter reduction of 50% or more on MRA or DSA, or an increase in peak systolic velocity greater than 150% (duplex) were considered significant. MRA examinations were evaluated by means of maximum intensity projections (MRA-MIP) and using source images and curved multiplanar reconstruction (MRA-MPR). Results: the sensitivity (specificity) for a significant iliac artery stenosis were 81% (75%) for MRA-MIP, 76% (75%) for MRA-MPR, 86% (88%) for DSA, and 72% (88%) for duplex. Conclusion: with intra-arterial pressure measurements as the reference method, similar results were achieved with Gd-MRA, DSA and duplex concerning the detection of haemodynamically significant iliac artery stenoses. The use of source images and multiplanar reconstructions resulted in higher accuracy for the detection of occlusions.

Lower extremity vascular reconstruction and endovascular surgery without preoperative angiography

Background: Recent studies have shown the feasibility of performing lower extremity revascularization based on noninvasive vascular studies alone. Methods: We undertook a prospective study of patients with lower extremity ischemia who underwent revascularization without preoperative angiography. Preoperative evaluation was done with noninvasive studies including segmental pressures, ankle arm index, duplex scan, and selective use of magnetic resonance angiography. Intraoperative angiography and intra-arterial pressure measurements were used prior to revascularization. Standard patency analysis and follow-up examination were performed. Results: In all, 47 patients underwent 65 procedures (27 iliac, 38 infrainguinal) over a 3-year period. Intraoperative angiography and operative findings correlated with the noninvasive studies. There was one immediate failure, and life table analysis demonstrated primary patency rates of 92% for iliac reconstruction (29 months) and 82% for infrainguinal reconstruction (40 months). Conclusion: Preoperative evaluation for lower extremity revascularization utilizing only noninvasive vascular testing gives satisfactory results and is a safe and potentially durable alternative to routine preoperative angiography in most cases.

Sources of error in intra-arterial pressure measurements across a stenosis

To investigate potential errors associated with different techniques of intra-arterial pressure measurement at angiography. An experimental model of an arterial stenosis was developed. Experiments were performed to assess the relevance of catheter position, catheter direction and catheter type on the recorded intraluminal pressure. Transstenotic pressure gradients were recorded with and without angiographic catheters crossing the stenosis. At physiological flow rates angiographic catheter type does not influence the recorded pressure. At high flow rates through tight stenoses there is a significant catheter-related difference in recorded pressure adjacent to a stenosis. Downstream pressures may be altered by up to 85 mmHg when standard angiographic catheters are placed across a stenosis. The different techniques employed to measure pressure differences across a model stenosis may introduce significant errors up to 85 mmHg. Care must be taken when pressure measurements alone are used to interpret the clinical significance of a stenosis. In low flow conditions there may not be a detectable pressure gradient across a 95% stenosis.

Hyperaemic colour duplex scanning for the detection of aortoiliac stenoses. A comparative study with intra-arterial pressure measurement

Intra-arterial pressure measurement is considered the "gold standard" for the haemodynamic evaluation of aortoiliac lesions. When compared to pressure measurement duplex scanning fails to detect some of the haemodynamically significant lesions. To improve the assessment of the haemodynamic significance of these lesions by duplex scanning, the flow-related duplex parameters delta PSV and EDV at rest and after exercise were compared with intra-arterial pressure gradients before and during increased blood flow. Forty-five aortoiliac segments with an isolated stenosis were studied prospectively. Doppler samples were taken at the site of the stenosis both at rest and after exercise on a bicycle ergometer, followed by intraarterial pressure measurement at rest and during pharmacologically induced increased blood flow. At rest a delta PSV (delta PSVr) of 1.6 m/s showed a sensitivity and specificity of 85% and 88%, respectively. After exercise a delta PSV (delta PSVe) of 1.6 m/s showed a sensitivity of 100% at the cost of only a slight reduction in specificity when compared to delta PSVr. The end diastolic velocity at rest (EDVr) had only limited clinical value. The EDV after exercise (EDVe) provided important information if the velocity was 0.5 m/s or lower or if the velocity was 1.6 m/s or greater. The delta PSV and the EDV after exercise can be of value in the assessment of the haemodynamic significance of aortoiliac stenoses.

Cardiovascular phenotype of a mouse strain with disruption of bradykinin B2-receptor gene.

To evaluate the role of kinins in the regulation of cardiovascular function, we studied the phenotype of a mouse strain with disruption of the bradykinin B2-receptor gene (Bk 2r-/-). Under basal conditions, tail-cuff blood pressure was higher in Bk2r-/- than in wild-type Bk2r+/+ and heterozygous Bk2r+/- mice (124+/-1 versus 109+/-1 and 111+/-2 mm Hg, respectively; P<.01 for both comparisons), a difference that was confirmed by measurements of intra-arterial blood pressure in unanesthetized mice. Heart weight was greater in Bk2r-/- than in Bk2r+/+ and Bk2r+/- mice (505+/-10 versus 449+/-12 and 477+/-10 mg/100 g body wt, P<.05). Chronic blockade of B2-receptors by Icatibant (50 nmol/100 g body wt twice a day S.C.) or inhibition of nitric oxide synthase by nitro-L-arginine-methyl ester (0.14 mmol/100 g body wt orally) increased the blood pressure of Bk2r+/+ to the levels of Bk2r-/- mice. Compared with the wild-type strain, both Bk2r-/- and Bk2r+/- mice showed exaggerated vasopressor responses to angiotensin II. In addition, chronic administration of an angiotensin AT1-receptor antagonist reduced the basal blood pressure of Bk2r-/- by 21+/-3 mmHg (P<.05) to the levels of Bk2r+/+. No difference was detected between strains as far as plasma renin activity and the expression of renin and AT1-receptor genes are concerned. Chronic salt loading (0.84 mmol/g chow for 15 days) increased the blood pressure of Bk2r-/- and Bk2r+/- by 34+/-3 and 14+/-6 mm Hg, respectively, whereas it was ineffective in Bk2r+/+. Our results suggest that a normally functioning B2-receptor is essential for the maintenance of cardiovascular homeostasis in mice. Dysfunction of the kallikrein-kinin system could contribute to increase blood pressure levels by leaving the activity of vasoconstrictor agents unbalanced.

Therapeutic consequences of variation in intraarterial pressure measurements after iliac angioplasty.

To assess the accuracy of intraarterial measurement of transstenotic pressure gradients for the detection of hemodynamically suboptimal iliac angioplasty. In 14 patients, referred for diagnostic angiography, mean pressure gradients in the aorta and iliac artery were obtained twice, using a double-sensor pressure catheter. Additional iliac measurements were performed during pharmacologically induced flow augmentation. Repeatability was assessed by calculation of the mean difference plus standard deviation (MD +/- SD) and repeatability coefficient (2 x SD). These results were extrapolated to 137 iliac angioplasty procedures with secondary stenting where there was a residual pressure gradient > 10 mmHg. MD +/- SD for repeated measurements at rest and during flow augmentation were 0 +/- 2 mmHg and 1 +/- 3 mmHg, respectively. Repeatability coefficients were 3 and 6 mmHg. Mean pressure gradients after hemodynamically insufficient angioplasty were 8 +/- 7 mmHg at rest and 17 +/- 5 mmHg following vasodilatation. Inaccurate pressure recordings may have led to inappropriate stent placement in less than 2.5%, and inappropriate denial of stent placement in less than 5% of the lesions. Variability of intraarterial pressure measurements has little consequence in the detection of hemodynamically significant stenosis after angioplasty.

Continuous blood pressure monitoring in cirrhosis: Relations to splanchnic and systemic haemodynamics

Background/Aims: Low arterial blood pressure is recognised as a distinctive factor in the hyperdynamic circulation in cirrhosis. 24-hour monitoring of the blood pressure and heart rate has recently revealed a reduced circadian variation with relation to liver function. However, associations with other clinical and haemodynamic characteristics have not been investigated and the aim of the present study was to identify splanchnic and systemic determinants of the 24-h blood pressure and heart rate in cirrhosis. Methods: The variables were measured by an automatic ambulant device for monitoring blood pressure and related to the results of an invasive haemodynamic investigation, including measurements of intra-arterial blood pressure (9.00–11.00 h) in 37 patients with cirrhosis. Results: The 24-h blood pressures were significantly lower and the heart rate was significantly higher in patients with cirrhosis than in matched controls ( p<0.05–0.001). To identify determinants of 24-h or intra-arterial blood pressures and heart rate, pertinent variables were included in a multivariate regression model. This model revealed that independent determinants of a low 24-h arterial blood pressure were a high post-sinusoidal resistance, a low plasma volume, a short central circulation time, and the presence of ascites. In contrast, a low intra-arterial blood pressure was determined by a low serum sodium, a low haemoglobin, and a high cardiac output. Diuretic treatment did not influence this model. Conclusions: Although the 24-h blood pressure and the intra-arterial blood pressure were determined by different variables, the overall results indicate that abnormalities in both splanchnic and central haemodynamics and sodium-water retention are important in the pathophysiology of arterial hypotension in patients with portal hypertension.

Effects of Cryopreservation on the Viscoelastic Properties of Human Arteries

The purpose of this study was to use our newly developed mock circulation loop to determine the effects of cryopreservation on the common carotid artery (CCA) and the superficial femoral artery (SFA). Fourteen healthy arteries (7 CCA and 7 SFA) harvested from multiple organ donors between the ages of 18 and 35 years were tested before and after cryopreservation at -140 degrees C using dimethyl sulfoxide and the vapor phase of liquid nitrogen. Mean storage time was 4.2 months. The mock pulse rate was 60 beats/min and the following four systolic/diastolic pressures settings were used: 50/110, 80/140, 110/170, and 140/200 mm Hg. Simultaneous measurements of intra-arterial pressure and external arterial diameter were made using an intra-arterial pressure sensor and external piezoelectric sensors. Measured data were used to calculate pulsatility, volumetric compliance, stiffness, midwall radial arterial stress, Young's modulus, and the incremental modulus. After SFA cryopreservation, no significant changes were observed. Conversely, CCA cryopreservation led to a significant decrease in compliance and pulsatility and a significant increase in stiffness. Young's modulus, the incremental modulus, and midwall radial arterial stress did not change significantly. A clearcut decrease in hysteresis was observed after cryopreservation in the CCA. No evidence of structural changes was detected on light and scanning electron microscopy. Baseline findings in this study were consistent with classification of the CCA as an elastic artery and the SFA as a muscular artery. Cryopreservation had no effect on the viscoelastic properties of muscular arteries (SFA). Cryopreservation affected only values related to the cylindrical shape of the elastic arteries (CCA). It had no effect on values related to wall structure.