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2.
Several cases of systemic arteriovenous fistula diagnosed in the human fetus have been associated with the postnatal development of persistent pulmonary hypertension. The aim of this study was to determine the effects of a prenatally created systemic arteriovenous fistula on the structure and reactivity of the pulmonary circulation in the fetal lamb. A fistula between the jugular vein and carotid artery was created in fetal lambs at 119-124 days of gestation. At delivery (134-139 days), left pulmonary artery (LPA) pressure was increased in the fistula group (n = 12) compared with controls (n = 11, P < 0.01). The pulmonary vascular resistance was significantly higher in the fistula group (P < 0.05), whereas mean LPA blood flow was not statistically different between the two groups. Morphometric analysis of the pulmonary vascular bed revealed an increase in the number of peripheral muscular arteries, together with an increase in pulmonary arterial medial thickness in the fistula group. There was no difference in the relative number or size of intraacinar arteries. In vitro organ bath studies on pulmonary arterial rings showed impaired endothelium-dependent relaxation in the fistula group compared with controls. However, endothelial nitric oxide synthase protein expression was similar in both groups, whereas endothelium-independent relaxation to sodium nitroprusside was greater in the fistula group compared with controls. A systemic arteriovenous fistula leads to both structural and functional alteration of the pulmonary vasculature, which might lead to the development of persistent pulmonary hypertension after birth.  相似文献   

3.
BACKGROUND: The autogenous brachiocephalic or brachiobasilic arteriovenous elbow fistula is not considered to be only the secondary haemodialysis access. In patients with an unsuitable forearm vessel bundle, it is indicated as primary access and it is the method preferred to the fistula creation using a vascular prosthesis. Its rather rare complication is the development of upper extremity ischemia. AIM: To summarise current knowledge of this fistula type and its associated complications METHODS: Review of the literature. RESULTS: The creation and maturation of the fistula and occurrence of the steal syndrome is influenced by a number of factors. The analysis and awareness of such factors will provide for creation of a suitable fistula as well as for timely complication diagnostics and treatment. CONCLUSIONS: The autogenous elbow fistula utilising the brachial artery and the cephalic or basilic vein in the upper extremity represents a high-quality haemodialysis access. Its potential complication is the occurrence of the steal syndrome. Its occurrence and manifestations do not constitute indications for ligation of the access. The gathered information shows that a suitable surgical procedure can help meet the basic rule for haemodialysis access--resolving the ischemia and maintaining the access.  相似文献   

4.
This investigation set out to determine the effect of 56 days of head-down tilt bed rest (HDBR) and an exercise countermeasure on endothelial dependent and independent vascular function. 24women took part in this study. 8 subjects completed lower body resistance and aerobic exercise (EX, treadmill running 3-4 days per week for 40-min followed by 10-min of static LBNP, and resistive exercise on a flywheel device every 3rd day) and 16 subjects were considered as non-exercisers in a control group and a protein supplement group. FMD was induced by release of distal limb ischemia and NMD by sublingual administration of 0.3 mg of nitroglycerin before and after HDBR. Preliminary results of this study suggest that HDBR without EX results in a decreased resting diameter of the popliteal while EX increased the diameter. It is also suggested that FMD was elevated without exercise in both brachial and popliteal arteries, while pre-HDBR FMD was preserved by EX in the popliteal, but not the brachial artery. NMD appears to be elevated in the popliteal and femoral in the absence of exercise, but unchanged in the brachial artery or at any site for EX.  相似文献   

5.
Restoration of arterial flow to a severely ischemic extremity remains a major challenge in vascular surgery. The procedure of choice for limb salvage is a bypass utilizing reversed saphenous vein. When the saphenous vein is unsuitable or unavailable, the surgeon must turn to endarterectomy of the femoral and popliteal systems or synthetic, composite, heterologous, autologous, or homologous grafts. To avoid the problems associated with these techniques and to improve the results of limb salvage, we have revived and modified the technique of superficial femoral artery eversion endarterectomy and combined it with other reconstructive techniques in an effort to salvage the severely ischemic lower extremity. Of 38 patients treated for incapacitating claudication or severe limb ischemia during a one-year period, six patients had an unsuitable saphenous vein for the proposed reconstruction. Five of these patients underwent superficial femoral eversion endarterectomy. These six patients have 100% patency at follow-up seven months to one year postoperatively. Our experience with these six patients, including angiographic follow-up, will be presented.  相似文献   

6.
Trauma to the popliteal artery is potentially dangerous, and limb loss may result, especially with delayed diagnosis. Three anatomic factors contribute to the seriousness of the outcome: proximity of the artery to bone, superficial position of the artery and consequent lack of protection, and frequent associated injury to associated collateral blood vessels. Diagnosis of injury to the popliteal artery rests on suspicion and vigilance; the Doppler transcutaneous flow detector and angiography are often useful aids to diagnosis. Methods of treatment that have been used include arterial repair, grafting and fasciotomy, together with management of associated injuries. The bypass principle of vascular reconstruction may improve overall results.  相似文献   

7.
Successful reconstructive surgery with muscle flaps depends on adequate arterial supply and undisturbed venous drainage. Combining such surgery with reconstructive vascular surgery of a large-caliber vein that is responsible for the venous drainage of the flap poses an additional challenge--the repaired vein's susceptibility to thrombosis. Every attempt must be made to prevent venous outflow obstruction following muscle flap surgery. Data from the vascular surgery literature demonstrate a low success rate for subclavian vein repair. The success rate with venous reconstructive surgery has been greater when a distal arteriovenous fistula accompanied the repair. The present case described the use of a temporary distal cephalic-brachial arteriovenous fistula to maintain the patency of the venous drainage of a pedicled latissimus dorsi muscle flap, following subclavian vein repair, for one-stage coverage of a large chest wall defect.  相似文献   

8.

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.  相似文献   

9.
A 10-month-old infant was found to have an isolated congenital arteriovenous fistula between the right subclavian artery and vein. Ligation of the fistula resulted in complete anatomic correction and rapid resolution of cardiomegaly.  相似文献   

10.
Gosain AK  Yan JG  Aydin MA  Das DK  Sanger JR 《Plastic and reconstructive surgery》2002,110(7):1655-61; discussion 1662-3
The vascular supply of the tensor fasciae latae flap and of the lateral thigh skin was studied in 10 cadavers to evaluate whether the lateral thigh skin toward the knee could be incorporated into an extended tensor fasciae latae flap. Within each cadaver, vascular injection of radiopaque material preceded flap elevation in one limb and followed flap elevation in the contralateral limb. Flaps raised after vascular injection were examined radiographically to evaluate the vascular anatomy of the lateral thigh skin independent of flap elevation. When vascular injection was made into the profunda femoris, the upper two-thirds of the flaps was better visualized than the distal third. When the injection was made into the popliteal artery, the vasculature of the distal third of the flaps was better visualized. Flaps raised before vascular injection were examined radiographically to delineate the anatomical territory of the vascular pedicle that had been injected. In these flaps, consistent cutaneous vascular supply was only seen in the skin overlying the tensor fasciae latae muscle, confirming that musculocutaneous perforators are the predominant means by which the pedicle of the tensor fasciae latae flap supplies the skin of the lateral thigh. Extended tensor fasciae latae flaps were elevated bilaterally in one cadaver, and selective methylene blue injections were made into the lateral circumflex femoral artery on one side and into the superior lateral genicular artery on the contralateral side. Methylene blue was observed in the proximal and distal thirds of the skin paddles, respectively, leaving unstained midzones. The vascular network of the lateral thigh skin could be divided into three zones. The lateral circumflex femoral artery and the third perforating branches of the profunda femoris artery perfuse the proximal and middle zones of the lateral thigh skin, respectively. The superior lateral genicular artery branch of the popliteal artery perfuses the distal zone. The middle and distal zones meet 8 to 10 cm above the knee joint, where the skin paddle of the tensor fasciae latae flap becomes unreliable. These data indicate that if the aim is to incorporate the skin over the distal thigh in an extended tensor fasciae latae flap without resorting to free-tissue transfer, then either a carefully planned delay procedure or an additional anastomosis to the superior lateral genicular artery is required.  相似文献   

11.
The purpose of this investigation was to examine the effect of rhythmic tetanic skeletal muscle contractions on peak muscle perfusion by using spontaneously perfused canine gastrocnemii in situ. Simultaneous pulsatile blood pressures were measured by means of transducers placed in the popliteal artery and vein, and pulsatile flow was measured with a flow-through-type transit-time ultrasound probe placed in the venous return line. Two series of experiments were performed. In series 1, maximal vasodilation of the muscles' vascular beds was elicited by infusing a normal saline solution containing adenosine (29.3 mg/min) and sodium nitroprusside (180 microg/min) for 15 s and then simultaneously occluding both the popliteal artery and vein for 5 min. The release of occlusion initiated a maximal hyperemic response, during which time four tetanic contractions were induced with supramaximal voltage (6-8 V, 0.2-ms stimuli for 200-ms duration at 50 Hz, 1/s). In series 2, the muscles were stimulated for 3 min before the muscle contractions were stopped for a period of 3 s; stimulation was then resumed. The results of series 1 indicate that, although contractions lowered venous pressure, muscle blood flow was significantly reduced from 2,056 +/- 246 to 1,738 +/- 225 ml x kg(-1) x min(-1) when contractions were initiated and then increased significantly to 1,925 +/- 225 ml x kg(-1) x min(-1) during the first 5 s after contractions were stopped. In series 2, blood flow after 3 min of contractions averaged 1,454 +/- 149 ml x kg(-1) x min(-1). Stopping the contractions for 3 s caused blood flow to increase significantly to 1,874 +/- 172 ml x kg(-1) x min(-1); blood flow declined significantly to 1,458 +/- 139 ml x kg(-1) x min(-1) when contractions were resumed. We conclude that the mechanical action of rhythmic, synchronous, maximal isometric tetanic skeletal muscle contractions inhibits peak muscle perfusion during maximal and near-maximal vasodilation of the muscle's vascular bed. This argues against a primary role for the muscle pump in achieving peak skeletal muscle blood flow.  相似文献   

12.
The study of hemodynamic alterations following the creation of an arteriovenous fistula (AVF) is relevant to vascular adaptive responses and hemodialysis access dysfunction. This study examined such alterations in a murine AVF created by anastomosing the carotid artery to the jugular vein. AVF blood flow was markedly increased due to reduced AVF vascular resistance. Despite such markedly increased basal blood flow, AVF blood flow further increased in response to acetylcholine. This AVF model exhibited increased cardiac output and decreased systemic vascular resistance; the kidney, in contrast, exhibited decreased blood flow and increased vascular resistance. Augmentation in AVF blood flow was attended by increased arterial heme oxygenase-1 (HO-1) mRNA and protein expression, the latter localized to smooth muscle cells of the AVF artery; AVF blood flow was substantially reduced in HO-1(-/-) mice compared with HO-1(+/+) mice. Finally, in a murine model of a representative disease known to exhibit impaired hemodynamic responses (sickle cell disease), the creation of an AVF was attended by decreased AVF flow and impaired AVF function. We conclude that this AVF model exhibits markedly increased AVF blood flow, a vasodilatory reserve capacity, increased cardiac output, decreased renal blood flow, and a dependency on intact hemodynamic responses, in general, and HO-1 expression, in particular, in achieving and maintaining AVF blood flow. We suggest that these findings support the utility of this model in investigating the basis for and the consequences of hemodynamic stress, including shear stress, and the pathobiology of hemodialysis AVF dysfunction.  相似文献   

13.
摘要 目的:探讨神经肌肉电刺激(NMES)联合间歇性充气加压预防颅脑外伤患者下肢深静脉血栓(LEDVT)的临床疗效,为预防LEDVT干预措施的选择提供依据。方法:将2020年11月至2021年8月于安徽中医药大学附属六安医院就诊的72例颅脑外伤患者纳入研究对象,随机数字法分为对照组和观察组,各组36例。对照组给予常规措施+间歇性充气加压干预,观察组在对照组基础上联合NMES干预。收集患者资料,比较两组LEDVT情况、卧床时间、住院时间、干预前后凝血功能指标[凝血酶原时间(PT)、活化部分凝血活酶时间(APTT)、D-二聚体(D-D)及纤维蛋白原(FIB)]水平、腘静脉、股总静脉血液流速、视觉疼痛模拟量表(VAS)评分,日常生活能力量表(ADL)评分。结果:观察组LEDVT发生率5.56%(2/36)低于对照组25.00%(9/36),卧床时间、住院时间短于对照组(P<0.05);两组干预后凝血功能指标PT、APTT、D-D、FIB水平较干预前显著改善,且观察组较对照组改善更为显著(P<0.05);两组干预后腘静脉、股总静脉血液流速、ADL评分较干预前升高,VAS评分较干预前降低,且观察组腘静脉、股总静脉血液流速、ADL评分高于对照组,VAS评分低于对照组(P<0.05)。结论:NMES联合间歇性充气加压干预能缩短颅脑外伤患者卧床时间和住院时间,改善患者凝血功能和血液循环,减少LEDVT的发生,且有助于减轻患者疼痛,提高患者生活能力。  相似文献   

14.
The endothelial cells of the umbilical vessels are frequently used in mechanobiology experiments. They are known to respond to wall shear stress (WSS) of blood flow, which influences vascular growth and remodeling. The in vivo environment of umbilical vascular WSS, however, is not well characterized. In this study, we performed detailed characterization of the umbilical vascular WSS environments using clinical ultrasound scans combined with computational simulations. Doppler ultrasound scans of 28 normal human fetuses from 32nd to 33rd gestational weeks were investigated. Vascular cross-sectional areas were quantified through 3D reconstruction of the vascular geometry from 3D B-mode ultrasound images, and flow velocities were quantified through pulse wave Doppler. WSS in umbilical vein was computed with Poiseuille’s equation, whereas WSS in umbilical artery was obtained via computational fluid dynamics simulations of the helical arterial geometry. Results showed that blood flow velocity for umbilical artery and vein did not correlate with vascular sizes, suggesting that velocity had a very weak trend with or remained constant over vascular sizes. Average WSS for umbilical arteries and vein was 2.81 and 0.52 Pa, respectively. Umbilical vein WSS showed a significant negative correlation with the vessel diameter, but umbilical artery did not show any correlation. We hypothesize that this may be due to differential regulation of vascular sizes based on WSS sensing. Due to the helical geometry of umbilical arteries, bending of the umbilical cord did not significantly alter the vascular resistance or WSS, unlike that in the umbilical veins. We hypothesize that the helical shape of umbilical arteries may be an adaptation feature to render a higher constancy of WSS and flow in the arteries despite umbilical cord bending.  相似文献   

15.
Portal hypertension, a major complication of cirrhosis, is caused by both increased portal blood flow due to arterial vasodilation and augmented intrahepatic vascular resistance due to sinusoidal constriction. In this study, we examined the possible involvement of resident macrophages in the tone regulation of splanchnic blood vessels using bile duct ligated (BDL) portal hypertensive rats and an in vitro organ culture method. In BDL cirrhosis, the number of ED2-positive resident macrophages increased by two- to fourfold in the vascular walls of the mesenteric artery and extrahepatic portal vein compared with those in sham-operated rats. Many ED1-positive monocytes were also recruited into this area. The expression of inducible nitric oxide (NO) synthase (iNOS) mRNA was increased in the vascular tissues isolated from BDL rats, and accordingly, nitrate/nitrite production was increased. Immunohistochemistry revealed that iNOS was largely expressed in ED1-positive and ED2-positive cells. We further analyzed the effect of iNOS expression on vascular smooth muscle contraction using an in vitro organ culture system. iNOS mRNA expression and nitrate production significantly increased in vascular tissues (without endothelium) incubated with 1 μg/ml lipopolysaccharide (LPS) for 6 h. Immunohistochemistry indicated that iNOS was largely expressed in ED2-positive resident macrophages. α-Adrenergic-stimulated contractility of the mesenteric artery was greatly suppressed by LPS treatment and was restored by N(G)-nitro-L-arginine methyl ester (NO synthase inhibitor); in contrast, portal vein contractility was largely unaffected by LPS. Sodium nitroprusside (NO donor) and 8-bromo-cGMP showed greater contractile inhibition in the mesenteric artery than in the portal vein with decreasing myosin light chain phosphorylation. In the presence of an α-adrenergic agonist, the mesenteric artery cytosolic Ca(2+) level was greatly reduced by sodium nitroprusside; however, the portal vein Ca(2+) level was largely unaffected. These results suggest that the induction of iNOS in monocytes/macrophages contributes to a hypercirculatory state in the cirrhosis model rat in which the imbalance of the responsiveness of visceral vascular walls to NO (mesenteric artery > portal vein) may account for the increased portal venous flow in portal hypertension.  相似文献   

16.
Hemodialysis vascular access can develop venous neointimal hyperplasia (VNH) causing stenosis. Recent clinical and experimental data has demonstrated that there is increased expression of a disintegrin and metalloproteinase thrombospondin motifs-1 (ADAMTS-1) at site of VNH. The experiments outlined in the present paper were designed to test the hypothesis that targeting of the adventitia of the outflow vein of murine arteriovenous fistula (AVF) using a small hairpin RNA that inhibits ADAMTS-1 expression (LV-shRNA-ADAMTS-1) at the time of fistula creation will decrease VNH. At early time points, ADAMTS-1 expression was significantly decreased associated with a reduction in vascular endothelial growth factor-A (VEGF-A) and matrix metalloproteinase-9 (MMP-9) (LV-shRNA-ADAMTS-1 transduced vessels vs. controls). These changes in gene and protein expression resulted in favorable vascular remodeling with a significant increase in mean lumen vessel area, decrease in media/adventitia area, with a significant increase in TUNEL staining accompanied with a decrease in cellular proliferation accompanied with a reduction in CD68 staining. Collectively, these results demonstrate that ADAMTS-1 transduced vessels of the outflow vein of AVF have positive vascular remodeling.  相似文献   

17.
Severe ischemia and distal gangrene of lower extremities due to obstruction of the popliteal artery and its branches need not require major amputation. Autogenous vein grafts to the distal anterior tibial, posterior tibial, peroneal and dorsalis pedis arteries can avoid tissue loss in many instances.  相似文献   

18.
《Endocrine practice》2013,19(3):e61-e63
ObjectiveTo present a case of Paget’s disease of bone that was unmasked after vascular reperfusion.MethodsIn this case study, we review the presentation, evaluation, diagnosis, and management of a patient with Paget’s disease and peripheral vascular disease.ResultsA 79-year-old-woman with a history of coronary artery heart disease and recent finding of a T5 compression fracture was hospitalized for evaluation of right lower extremity claudication. Angiography demonstrated a focal complete occlusion of the distal right femoral and popliteal arteries. A self-expanding stent was placed in the distal femoral and popliteal arteries. Approximately 48 hours after the procedure, the patient developed severe, right lower leg pain. On endocrine evaluation, the patient was found to have clinical signs suggesting Paget’s disease of bone, which was subsequently confirmed by imaging.ConclusionThis patient’s development of severe pain following reperfusion of distal femoral and popliteal arteries is in keeping with the known and aforementioned hypervascularity of pagetic bone. The finding of increased warmth over an area of skeletal deformation should always raise the possibility of Paget’s disease of bone.(Endocr Pract. 2013;19:e61-e63)  相似文献   

19.
Recent evidence supports the hypothesis that the mechanism by which glyceryl trinitrate induces relaxation of vascular smooth muscle involves the biotransformation of glyceryl trinitrate. This study was conducted to determine if there was a direct correlation between the capacity of vascular smooth muscle preparations to biotransform glyceryl trinitrate and their sensitivity to the relaxant effect of this organic nitrate. Isolated bovine pulmonary arteries and veins were contracted submaximally and cumulative dose-response relationships to glyceryl trinitrate were obtained; the vein was approximately 10 times more sensitive than the artery to glyceryl trinitrate induced relaxation. In a separate series of experiments, these vascular tissues were contracted submaximally and incubated with 0.5 microM [14C]glyceryl trinitrate for 2 min, during which glyceryl trinitrate induced relaxation was monitored. At 2 min, tissue samples were taken for determination of glyceryl trinitrate and glyceryl-1,2- and 1,3-dinitrate content by thin-layer chromatography and liquid scintillation spectrometry. Biotransformation of glyceryl trinitrate to glyceryl dinitrate occurred concomitantly with relaxation of these blood vessels. The concentration of glyceryl dinitrate in the vein was significantly less than that in the artery (p less than or equal to 0.05), even though significantly greater relaxation of the vein than the artery was observed (p less than or equal to 0.05). From these data, a simple linear relationship between glyceryl trinitrate biotransformation and relaxation is not apparent.  相似文献   

20.
The thoracodorsal artery perforator flap is a relatively new flap that has yet to find its niche in reconstructive surgery. At the authors' institution it has been used for limb salvage, head and neck reconstruction, and trunk reconstruction in cases related to trauma, burns, and malignancy. The authors have found the flap to be advantageous for cranial base reconstruction and for resurfacing the face and oral cavity. The flap has been used successfully for reconstruction of traumatic upper and lower extremity defects, and it can be used as a pedicled flap or as a free tissue transfer. The perforating branches of the thoracodorsal artery offer a robust blood supply to a skin-soft-tissue paddle of 10 to 12 cm x 25 cm, overlying the latissimus dorsi muscle. The average pedicle length is 20 cm (range, 16 to 23 cm), which allows for a safe anastomosis outside the zone of injury in traumatized extremities; the flap can be made sensate by neurorrhaphy with sensory branches of the intercostal nerves. Vascularized bone can be transferred with this flap by taking advantage of the inherent vascular anatomy of the subscapular artery. A total of 30 pedicled and free flap transfers were performed at the authors' institution with an overall complication rate of 23 percent and an overall flap survival rate of 97 percent. Major complications, such as vascular thrombosis, return to the operating room, fistula formation, recurrence of tumor, and flap loss, occurred in 17 percent of the patients. Despite these drawbacks, the authors have found the thoracodorsal artery perforator flap to be a safe and extremely versatile flap that offers significant advantages in acute and delayed reconstruction cases.  相似文献   

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