Simulation of lower limb axial arterial length change during locomotion

The effect of external forces on axial arterial wall mechanics has conventionally been regarded as secondary to hemodynamic influences. However, arteries are similar to muscles in terms of the manner in which they traverse joints, and their three-dimensional geometrical requirements for joint motion. This study considers axial arterial shortening and elongation due to motion of the lower extremity during gait, ascending stairs, and sitting-to-standing motion. Arterial length change was simulated by means of a graphics based anatomic and kinematic model of the lower extremity. This model estimated the axial shortening to be as much as 23% for the femoropopliteal arterial region and as much as 21% for the iliac artery. A strong correlation was observed between femoropopliteal artery shortening and maximum knee flexion angle (r2=0.8) as well as iliac artery shortening and maximum hip angle flexion (r2=0.9). This implies a significant mechanical influence of locomotion on arterial behavior in addition to hemodynamics factors. Vascular tissue has high demands for axial compliance that should be considered in the pathology of atherosclerosis and the design of vascular implants.     

Three-dimensional bending,torsion and axial compression of the femoropopliteal artery during limb flexion

High failure rates of femoropopliteal artery reconstruction are commonly attributed to complex 3D arterial deformations that occur with limb movement. The purpose of this study was to develop a method for accurate assessment of these deformations. Custom-made stainless-steel markers were deployed into 5 in situ cadaveric femoropopliteal arteries using fluoroscopy. Thin-section CT images were acquired with each limb in the straight and acutely bent states. Image segmentation and 3D reconstruction allowed comparison of the relative locations of each intra-arterial marker position for determination of the artery’s bending, torsion and axial compression. After imaging, each artery was excised for histological analysis using Verhoeff–Van Gieson staining. Femoropopliteal arteries deformed non-uniformly with highly localized deformations in the proximal superficial femoral artery, and between the adductor hiatus and distal popliteal artery. The largest bending (11±3–6±1 mm radius of curvature), twisting (28±9–77±27°/cm) and axial compression (19±10–30±8%) were registered at the adductor hiatus and the below knee popliteal artery. These deformations were 3.7, 19 and 2.5 fold more severe than values currently reported in the literature. Histology demonstrated a distinct sub-adventitial layer of longitudinally oriented elastin fibers with intimal thickening in the segments with the largest deformations. This endovascular intra-arterial marker technique can quantify the non-uniform 3D deformations of the femoropopliteal artery during knee flexion without disturbing surrounding structures. We demonstrate that 3D arterial bending, torsion and compression in the flexed lower limb are highly localized and are substantially more severe than previously reported.     

Relative and combined effects of ethanol and protein deficiency on strontium and barium bone content and fecal and urinary excretion

To elucidate accumulation of minerals in human iliac arteries with aging, the content of minerals was analyzed by inductively coupled plasma atomic emission spectrometry. Bilateral common, internal, and external iliac arteries of 16 men and 8 women, ranging ages from 65 to 93 yr, were examined. It was found that an extremely high accumulation of calcium and phosphorus occurred in the common iliac artery at old age, being higher than that of the internal and external iliac arteries. It should be noted that the accumulation of calcium and phosphorus is the highest in the common iliac artery among the human arteries examined to date. Regarding sexual differences, the content of calcium and phosphorus in the common and internal iliac arteries was higher in women than in men, whereas their content in the external iliac artery was lower in women than in men.     

Differential constrictor responses of cephalic and caudal vasculature to α-adrenoceptor agonist after hind limb unloading

We examined the effects of hind limb unloading (HLU, 14 days) on constriction of carotid and iliac arterial beds in vivo in thiobutabarbital-anaesthetized rats and isolated carotid and iliac arteries in vitro. Both control and HLU rats had similar arterial pressure and carotid and iliac arterial flows. The HLU rats had increased carotid arterial but reduced iliac arterial constriction in response to methoxamine (α1-adrenoceptor agonist) in vivo. In contrast, constriction in response to methoxamine was reduced in the isolated carotid and unchanged in the iliac artery of HLU rats relative to control rats. Thus, HLU is associated with increased constriction of carotid arterial bed but reduced constriction of the isolated carotid artery, and reduced constriction of iliac arterial bed but unchanged constriction of the isolated iliac artery. These results show differential influence of HLU on constriction of cephalic and caudal arterial beds, and differential effect on constrictions of arterial beds relative to conduit arteries.     

盆腔疾病髂内动脉栓塞术的研究进展

髂内动脉栓塞是盆腔出血性疾病和肿瘤治疗的重要治疗方法,常规采用Seldinger技术,从一侧股动脉径路两侧髂内动脉选择性与超选择性插管。髂内动脉是盆腔脏器主要供血来源,根据数字减影动脉造影术（Digital subtraction arteriography,DSA）功能可分为：常规DSA,旋转DSA,平板数字减影旋转血管造影与三维血管重建和路图技术。栓塞剂可分为颗粒型和液态型栓塞剂。本文综述了盆腔疾病髂内动脉栓塞术近年来的研究进展。     

Advanced Age and Disease Predict Lack of Symptomatic Improvement after Endovascular Iliac Treatment in Male Veterans

Background: Endovascular angioplasty and stent placement is currently the most frequent treatment for iliac artery occlusive disease. However, despite a successful endovascular procedure, some patients do not experience symptomatic improvement and satisfaction with their care. This study seeks to identify patient-related factors associated with lack of symptomatic improvement after endovascular iliac artery treatment in male veterans.Methods: Retrospective review of patients treated with endovascular methods for iliac artery occlusive disease between January 2008 and July 2012 at VA Connecticut Healthcare System. Symptomatic improvement on the first post-operative visit was evaluated, with bilateral treatments counted separately.Results: Sixty-two patients had 91 iliac arteries treated with angioplasty and stent placement. Forty-seven (52 percent) legs had critical limb ischemia, and 77 (85 percent) had at least two-vessel distal runoff. Angiographic success was 100 percent. Patient-reported symptomatic improvement at the first post-operative visit was 55 percent (50/91). Lack of symptomatic improvement correlated with older age (OR 1.09 [1.03-1.17], p = 0.008), presence of critical limb ischemia (OR 3.03 [1.09-8.65], p = 0.034), and need for additional surgical intervention (OR 5.61 [1.65-17.36], p = 0.006). Survival, primary and secondary patency, and freedom from restenosis were comparable between patients who reported symptomatic improvement and those who did not.Conclusions: Despite angiographically successful revascularization, patients who are older or have critical limb ischemia who are treated with isolated endovascular iliac artery intervention are more likely to require additional interventions and less likely to experience symptomatic improvement. These patients may need more extensive infra-inguinal revascularization than isolated iliac angioplasty and stent placement, despite a preserved ankle-brachial index. Quality of life needs to be measured with formal instruments after iliac artery endovascular treatment, especially to determine long term outcomes.     

Effect of balloon pre-dilation on performance of self-expandable nitinol stent in femoropopliteal artery

Balloon pre-dilation is usually performed before implantation of a nitinol stent in a femoropopliteal artery in a case of severe blockage or calcified plaque. However, its effect on performance of the nitinol stent in a diseased femoropopliteal artery has not been studied yet. This study compares the outcomes of stenting with pre-dilation and without it by modelling the entire processes of stent deployment. Fatigue deformation of the implanted stent is also modelled under diastolic–systolic blood pressure, repetitive bending, torsion, axial compression and their combination. Reduced level of stress in the stent occurs after stenting with pre-dilation, but causing the increased damage in the media layer, i.e. the middle layer of the arterial wall. Generally, pre-dilation increases the risk of nitinol stent’s fatigue failure. Additionally, the development of in-stent restenosis is predicted based on the stenting-induced tissue damage in the media layer, and no severe mechanical irritation is induced to the media layer by pre-dilation, stent deployment or fatigue loading.

     

Differences in alpha 1-adrenoceptor mechanisms for phenylephrine and tizanidine in rabbit thoracic aorta and common iliac artery.

Based on affinity for WB4101 and susceptibility to chloroethylclonidine, we evaluated the subtype of alpha 1-adrenoceptors activated by phenylephrine (a full agonist) and tizanidine (a partial agonist). The rabbit thoracic aorta and common iliac artery contain both alpha 1A- and alpha 1B-adrenoceptors, but the alpha 1B-subtype may be more predominantly in the common iliac artery than in the thoracic aorta. In rabbit thoracic aorta and common iliac artery, phenylephrine induced contraction through both alpha 1A- and alpha 1B-subtypes and tizanidine through only the alpha 1A-subtype. The subtype activated by phenylephrine may be partly different from that activated by tizanidine in the preparations used herein.     

Life-threatening bleeding after pelvic lymphadenectomy for cervical cancer: endovascular management of ruptured false aneurysm of the external iliac artery

ABSTRACT: Late rupture of external iliac artery pseudo-aneurysm is an uncommon complication in patients who undergo extensive gynecologic radical surgeries. A 28-year-old woman with stage IB cervical cancer underwent pelvic lymphadenectomy and extrafascial trachelectomy. Two months after surgery, massive bleeding from ruptured pseudo-aneurysm of the external iliac artery occurred. Endovascular management with covered stent placement was feasible and safe to stop bleeding.     

The role of adaptive structures in the umbilical arteries in regulating the blood flow in the internal iliac artery system

A complex of special structures having compensatory-adaptive character has been found in the umbilical artery wall of a mature dog. The role of the structures revealed is to participate in an active regulation of the blood stream. In the test animals with a model of the blood stream disorder in the iliac artery reservoir, the importance of the structures of its active regulation increases. The investigations performed have stated the fact, that the canine umbilical artery during the postnatal period of ontogenesis actively participates in regulation of the blood stream in the internal iliac artery reservoir. In some cases the umbilical artery plays the role of a blocking artery, in others--as a powerful arteriovenous formation and it is able to participate in distribution and regulation of the blood stream.     

Age-related changes of elements in thoracic and abdominal aortas and coronary, common carotid, pulmonary, splenic, common iliac, and uterine arteries and relationships in elements among their arteries

To elucidate whether the accumulation of elements occurred simultaneously in the various arteries with aging, the authors investigated age-related changes of elements in the eight arteries, such as the thoracic and abdominal aortas and the coronary, common carotid, pulmonary, splenic, common iliac, and uterine arteries, and the relationships in the element contents among their arteries. After ordinary dissection by medical students was finished, the thoracic and abdominal aortas and the coronary, common carotid, pulmonary, splenic, common iliac, and uterine arteries were resected from the subjects, who ranged in age from 58 to 94 yr. The element contents were analyzed by inductively coupled plasma-atomic emission spectrometry. It was found that the accumulation of Ca was the highest in the common iliac artery and decreased in the order of the uterine artery, abdominal aorta, coronary artery, thoracic aorta, splenic artery, common carotid artery, and pulmonary artery. Regarding the relationships in the element contents among the eight arteries, it was found that there were significant direct correlations in the contents of Ca, P, Mg, Zn, Fe, and Na between the coronary and splenic arteries, and there were significant correlations in the contents of Ca, P, and Mg between the abdominal aorta and pulmonary artery.     

Combined Effects of Flow Diverting Strategies and Parent Artery Curvature on Aneurysmal Hemodynamics: A CFD Study

Purpose

Flow diverters (FD) are increasingly being considered for treating large or giant wide-neck aneurysms. Clinical outcome is highly variable and depends on the type of aneurysm, the flow diverting device and treatment strategies. The objective of this study was to analyze the effect of different flow diverting strategies together with parent artery curvature variations on altering intra-aneurysmal hemodynamics.

Methods

Four ideal intracranial aneurysm models with different parent artery curvature were constructed. Computational fluid dynamics (CFD) simulations of the hemodynamics before and after applying five types of flow diverting strategies (single FD, single FD with 5% and 10% packing density of coils, two FDs with 25% and 50% overlapping rate) were performed. Changes in pressure, wall shear stress (WSS), relative residence time (RRT), inflow velocity and inflow volume rate were calculated and compared.

Results

Each flow diverting strategy resulted in enhancement of RRT and reduction of normalized mean WSS, inflow volume rate and inflow velocity in various levels. Among them, 50% overlapped FD induced most effective hemodynamic changes in RRT and inflow volume rate. The mean pressure only slightly decreased after treatment. Regardless of the kind of implantation of FD, the mean pressure, inflow volume rate and inflow velocity increased and the RRT decreased as the curvature of the parent artery increased.

Conclusions

Of all flow diverting strategies, overlapping FDs induced most favorable hemodynamic changes. Hemodynamics alterations post treatment were substantially influenced by parent artery curvature. Our results indicate the need of an individualized flow diverting strategy that is tailored for a specific aneurysm.     

Simultaneous accumulation of magnesium with calcium and phosphorus in aorta and iliac arteries of thai

To elucidate compositional changes of arteries with aging, the authors previously investigated age-related changes of mineral contents in the various arteries of Japanese and Japanese monkey. To examine whether there were differences between races in regard to age-related changes of mineral contents and the relationships among element contents in the arteries, the authors investigated the arteries of Thai. The subjects consisted of 13 men and 3 women, ranging in age from 39 to 84 yr. After the ordinary dissection at Chiang Mai University was finished, abdominal aortas, common iliac, internal iliac, and external iliac arteries were resected and the element contents were determined by inductively coupled plasma-atomic emission spectrometry. The contents of calcium, phosphorus, and magnesium became the highest in the fifties in the abdominal aorta, common iliac, and external iliac arteries, whereas the contents of calcium and magnesium became the highest in the sixties in the internal iliac artery, and decreased thereafter. In regard to relationships among element contents, it was found that there were high correlations between calcium and phosphorus contents, between calcium and magnesium contents, and between phosphorus and magnesium in all of the abdominal aortas and three iliac arteries. The mass ratios of magnesium to calcium and phosphorus were each similar in the abdominal aorta, common iliac, and internal iliac arteries, except for the external iliac artery, in which it was slightly high. These revealed that as calcium and phosphorus increased in the arteries with aging, magnesium increased in the arteries as well. The differences between the arteries of Thai and Japanese were discussed in the present article.     

A comparison of the long-term morbidity following deep circumflex iliac and fibula free flaps for reconstruction following head and neck cancer

Composite free tissue transfer has an established role in head and neck oncology for the reconstruction of the bony defect following tumor ablation, and while donor-site morbidity is variably reported, there is little consensus on the most favorable donor site. The fibula and deep circumflex iliac artery have distinct advantages in terms of the volume and length of bone in mandibular reconstruction. Few studies have compared their donor-site morbidity. The aim of this study was to compare the fibula and deep circumflex iliac artery flaps using a review of the case notes and cross-sectional review of patients attending a research clinic for validated orthopedic examination and completion of health-related quality-of-life questionnaires. Between February of 1993 and May of 2001, 44 fibula free flaps and 73 deep circumflex iliac artery free flaps were performed. Ninety-nine case notes and 36 patients were available for review of donor-site morbidity. Sixteen patients with fibula flaps and 20 patients with deep circumflex iliac artery flaps took part in the clinical examination component of the study, which was composed of a clinical examination by an orthopedic surgeon using the American Orthopedic Foot and Ankle Society ankle scoring system and the Harris hip scoring system, and two patient-completed questionnaires, the University of Washington Questionnaire and the Hospital Anxiety and Depression Scale. Subjective and objective markers of morbidity related to both flaps were similar in most parameters. However, fibula flaps were associated with more problems with donor-site healing, reduced power, and sensation. Poor orthopedic scores for both flaps were associated with notably poor scores on the University of Washington Questionnaire and the Hospital Anxiety and Depression Scale. The study would suggest that both deep circumflex iliac artery and fibula donor sites result in an acceptable and comparable morbidity for most patients, but in cases in which significant donor-site morbidity is encountered, health-related quality of life is significantly compromised.     

Early calcification patterns of the iliac arteries and their relation to the arterial structure

Summary Gross calcifications of the common iliac and internal iliac arteries represent a common finding in newborn children and infants. In both arteries, the calcific deposits regularly appear in certain areas of the arterial luminal surface only, whereas the other parts of the arterial wall remain free of gross lesions even in cases with a pronounced calcification. In the common iliac artery, the lateral wall of the vessel and the adjacent sectors of the anterior and posterior wall represent the predilection site of calcific deposits. In the internal iliac artery, the gross calcifications have been regularly demonstrated in the dorso-medial wall. The predominant localisation of the calcification in these parts of the vessels and its absence in the others depend on the definite structural features of the arterial tube and different affinity for calcium of the individual structural elements. In both iliac arteries, only the primary internal elastic membrane undergoes early calcification. However, unlike the most muscular arteries, this membrane is not developed in the whole arterial circumference of the common iliac and internal iliac arteries, but is absent in large areas of their arterial luminal layer. In these areas, the subendothelial or subintimal elastic layers are formed by the networks of longitudinally arranged elastic fibers or membraneous elastic structures which arise from the elastic networks with the further growth. These elastic elements always stay free of calcific deposits. The structural features found in both iliac arteries may be important for the development of the later pathological changes.     

Traumatic aneurysm in persistent sciatic artery

A 59-year-old male patient admitted to our hospital with a pulsatile right gluteal mass with history of formation after blunt trauma. Persistent sciatic artery and its traumatic aneurysm was diagnosed after medical examination followed by peripheric digital substraction angiography. Surgery was performed under general anesthesia, and the patient was discharged from the hospital on postoperative day 7 without any problems. The sciatic artery, a continuation of the internal iliac artery into the popliteal-tibial vessels, represents the major blood supply to the lower limb in early embryologic development. Its persistence is very rare, and the aneurysmatic dilatation is the most common pathology diagnosed. Here, we present a rare case of persistent sciatic artery presenting with a traumatic aneurysm treated by iliopopliteal bypass surgery and ligation of the internal iliac artery proximal to the aneurysm.     

Estimation of the functional role of arterial pathways to the buttock circulation during treadmill walking in patients with claudication.

The aim of the study was to estimate the functional contribution of the arterial inflow pathways to the pelvic circulation during walking in patients with stage 2 lower extremity arterial disease. Transcutaneous oxygen pressure (Ptc(O(2))) changes during exercise can be used to estimate the severity of regional blood flow impairment while walking. Seventy patients with stable lower limb claudication were studied using a multivariate linear regression model. The relationship between exercise-induced buttock Ptc(O(2)) changes, the ipsilateral calf Ptc(O(2)) changes, and the arterial diameters of the pelvic arteriographic pathways were analyzed. The ipsilateral hypogastric and lumbar pathway, as well as the ipsilateral calf Ptc(O(2)) changes, were the only variables significantly related to buttock Ptc(O(2)) changes (r = 0.47; P < 0.001). Their normalized respective contribution to the regressive model was 39%, 19%, and 18%. None of the contralateral hypogastric, mesenteric, and sacral pathways or pathways stemming from the external iliac artery showed significant correlation to buttock Ptc(O(2)) changes. The ipsilateral hypogastric and ipsilateral lumbar pathways are the major pathways responsible for the functional buttock blood flow supply during walking. The role of contralateral hypogastric, inferior mesenteric, and median sacral pathways and arteries distal to the internal iliac trunk is negligible in the normal or compensatory blood flow supply. Distal Ptc(O(2)) decrease at exercise aggravates proximal Ptc(O(2)) decrease, possibly through the occurrence of a "steal phenomenon" of distal over proximal circulation during walking.     

The significance of subclavian artery injection prior to surgical myocardial revascularization

Successful arterial revascularization using the internal thoracic artery is dependent on unobstructed inflow through the subclavian artery. Systematic physical examination should discover subclavian stenosis; however, simple routine injection into the orifice of the subclavian artery during the diagnostic catheterization may avoid a catastrophic outcome.     

Do P2X purinergic receptors regulate skeletal muscle blood flow during exercise?

Although there is evidence that sympathetic nerves release ATP as a neurotransmitter to produce vasoconstriction via P2X purinergic receptors, the role of these receptors in the regulation of blood flow to exercising skeletal muscle has yet to be determined. We hypothesized that there is tonic P2X receptor-mediated vasoconstriction in exercising skeletal muscle. To test this hypothesis, the effect of P2X receptor blockade on skeletal muscle blood flow was examined in six exercising mongrel dogs. P2X receptor antagonism was accomplished with pyridoxal-phosphate-6-azophenyl-2'4'-disulfonic acid (PPADs). Animals were instrumented chronically with flow probes on the external iliac arteries of both hindlimbs and a catheter in one femoral artery. PPADs (40 mg) was infused as a bolus into the femoral artery catheter during steady-state exercise at 6 miles/h. Intra-arterial infusion of PPADs increased iliac blood flow from 542 +/- 55 to 677 +/- 69 ml/min (P < 0.05) and iliac vascular conductance from 5.17 +/- 0.62 to 6.53 +/- 0.80 ml.min(-1).mmHg(-1). The PPADs infusion did not affect blood flow in the contralateral iliac artery. These data support the hypothesis that P2X purinergic receptors produce vasoconstriction in exercising skeletal muscle.     

Monophasic synovial sarcoma presenting as a primary ileal mass: a case report and review of the literature

Introduction

Iliocaval fistulas can complicate an iliac artery aneurysm. The clinical presentation is classically a triad of hypotension, a pulsatile mass and heart failure. In this instance, following presentation with multiorgan failure, management included the immediate use of an endovascular stent graft on discovery of the fistula.

Case presentation

A 62-year-old Caucasian man presented to our tertiary hospital for management of iatrogenic trauma due to the insertion of a central venous line into his right common carotid artery, causing transient ischemic attack. Our patient presented to a peripheral hospital with fever, nausea, vomiting, acute renal failure, acute hepatic dysfunction and congestive heart failure. A provisional diagnosis of sepsis of unknown origin was made. There was a 6.5 cm×6.5 cm right iliac artery aneurysm present on a non-contrast computed tomography scan. An unexpected intra-operative diagnosis of an iliocaval fistula was made following the successful angiographic removal of the central line to his right common carotid artery. Closure of the iliocaval fistula and repair of the iliac aneurysm using a three-piece endovascular aortic stent graft was then undertaken as part of the same procedure. This was an unexpected presentation of an iliocaval fistula.

Conclusion

Our case demonstrates that endovascular repair of a large iliac artery aneurysm associated with a caval fistula is safe and effective and can be performed at the time of the diagnostic angiography. The presentation of an iliocaval fistula in this case was unusual which made the diagnosis difficult and unexpected at the time of surgery. The benefit of immediate repair, despite hemodynamic instability during anesthesia, is clear. Our patient had two coronary angiograms through his right femoral artery decades ago. Unusual iatrogenic causes of iliocaval fistulas secondary to previous coronary angiograms with wire and/or catheter manipulation should be considered in patients such as ours.