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Doppler ultrasonography is the main modality for imaging of hemodialysis AV ?stula as it is safe and non-invasive. This study is to measure the Arterio-venous (AV) ?stula blood ?ow during early postoperative period (0–7days) and assess its role in AV ?stula failure prediction. Doppler ultrasonography was used to estimate the blood ?ow in the AV ?stula of 50 patients at (0–7days) after the ?stula was made. The blood ?ow in ?stula during early postoperative period for ?stula failure was evaluated, and long term failure was predicted. Blood ?ow rates Method measured in arteriovenous ?stula created in upper extremity were measured in ?rst week and sixth week post-operative. Results After follow up evaluation out of 50 patients, 40 ?stulas considered to be matured; 10 considered failed. 30% failure were males and 70% were female. In early post operative period, cut off was set at 182 ml/min and the sensitivity of blood ?ow for prediction of ?stula failure is 98%, speci?city 90 %, PPV 95% and NPV 90%. Measurements of the AV ?stula blood Conclusion ?ow in proximal artery and draining vein with its diameter of lumen were noted in the early postoperative period has a role predicting AV ?stula failure. There is risk of failure if the blood ?ow less than 182 ml/min (day 0–7)
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Objective To explore the hemodynamic characteristics in functional side-to-end (STE) anastomosis arteriovenous fistula (AVF) by computational fluid dynamics (CFD), so as to provide theoretical basis for clinical application of the AVF. Methods AVF models of functional STE anastomosis (STE group) and conventional STE anastomosis (cSTE group) were established. The hemodynamic parameters of models in two groups under retrograde and antegrade flow states were analyzed, including blood flow velocity, pressure drop, low wall shear stress area (LWSSA). Results Under retrograde flow, the total LWSSA in STE group was 5.70% lower than that in cSTE group, and the LWSSA on venous wall in STE group was 49.71% lower than that in cSTE group. Under antegrade flow, the total LWSSA in STE group was 6.97% greater than that in cSTE group, and the LWSSA on venous wall in STE group was 10.62% lower than that in cSTE group. Conclusions Under retrograde flow state, functional STE anastomosis can significantly decrease the LWSSA of AVF, while under antegrade flwo state, functional STE anastomosis has no significant impact on improving the LWSSA of AVF.
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Objective • To investigate the feasibility of four-dimensional flow MRI (4D flow MRI) in evaluating the hemodynamics of forearm autologous arteriovenous fistula (AVF) in renal dialysis patients. Methods • Forty-five patients from Renal Division of Renji Hospital, Shanghai Jiao Tong University School of Medicine were included. Patients with forearm AVF underwent ultrasonography and MRI. The consistency of 4D flow MRI hemodynamic parameters measured by two radiologists and hemodynamic parameters at the same plane of AVF by 4D flow MRI and ultrasonography were analyzed by paired t test. The morphological parameters of AVF were acquired from black blood sequence, and they were used for Pearson correlation analysis with the hemodynamic parameters obtained from 4D flow MRI. Results • Forty-two patients completed the forearm AVF ultrasonography and MRI successfully. Paired t test showed that the consistency of 4D flow MRI hemodynamic parameters by two radiologists was good (all P=0.000), and all hemodynamic parameters measured by 4D flow MRI and ultrasonography were in good agreement (r=0.292-0.569, all P0.05). Pearson correlation analysis showed that the cephalic venous flow volume of AVF was correlated with the diameter ratio of the cephalic venous to radial artery and the anastomosis area ( r=-0.671, r=0.482, both P<0.05), and the wall shear stress (WSS) near the anastomosis was correlated with the anastomosis angle and wall thickness (r=0.530, r=0.462, both P<0.05). Conclusion • 4D flow MRI can be used to evaluate the hemodynamic parameters of forearm AVF in renal dialysis patients, which can provide a reference for further study of AVF dysfunction.
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Objective · To investigate the feasibility of four-dimensional flow MRI (4D flow MRI) in evaluating the hemodynamics of forearm autologous arteriovenous fistula (AVF) in renal dialysis patients. Methods · Forty-five patients from Renal Division of Renji Hospital, Shanghai Jiao Tong University School of Medicine were included. Patients with forearm AVF underwent ultrasonography and MRI. The consistency of 4D flow MRI hemodynamic parameters measured by two radiologists and hemodynamic parameters at the same plane of AVF by 4D flow MRI and ultrasonography were analyzed by paired t test. The morphological parameters of AVF were acquired from black blood sequence, and they were used for Pearson correlation analysis with the hemodynamic parameters obtained from 4D flow MRI. Results · Forty-two patients completed the forearm AVF ultrasonography and MRI successfully.Paired t test showed that the consistency of 4D flow MRI hemodynamic parameters by two radiologists was good (all P=0.000), and all hemodynamic parameters measured by 4D flow MRI and ultrasonography were in good agreement (r=0.292-0.569, all P＜0.05) except for the peak flow velocity at anastomosis (r=-0.078, P＞0.05). Pearson correlation analysis showed that the cephalic venous flow volume of AVF was correlated with the diameter ratio of the cephalic venous to radial artery and the anastomosis area (r=-0.671, r=0.482, both P＜0.05), and the wall shear stress (WSS) near the anastomosis was correlated with the anastomosis angle and wall thickness (r=0.530, r=0.462, both P＜0.05). Conclusion · 4D flow MRI can be used to evaluate the hemodynamic parameters of forearm AVF in renal dialysis patients, which can provide a reference for further study of AVF dysfunction.
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<b>Objective:</b> The aim of the present study was to consider the importance of medical information obtained via the Internet for difficult cases in hospitals, especially in those located in rural areas. We report here a case of congenital arteriovenous fistula (AVF) in the upper extremities. <br><b>Patient:</b> A 30-year-old lady was transported to our hospital by ambulance due to massive bleeding in her left hand. She was seen by our current cardiovascular surgery team for the first time, although she had been diagnosed with congenital AVF of the left arm 9 years previously. Because it was asymptomatic, she was followed up by observation. During 5 years of observation, symptoms such as cyanosis, pain, and refractory ulcers gradually developed. When she was 26 years old, she was referred to a university hospital in Akita, but surgery had already been judged to be impossible. When she was 30 years old, traumatic bleeding in her left hand and hemorrhagic shock led her to be taken to our hospital by ambulance. Using the Internet, we found an institution that had treated a large number of cases of AVF. After controlling the bleeding, we referred her to that institution. However, she could not be treated without an above-elbow amputation. <br><b>Conclusion:</b> Congenital AVF in the upper extremities is a rare vascular anomaly and has been generally accepted to be an extremely difficult disease to treat. Treatment should be started as early as possible before the presence of any symptoms. When a specialist is not available near the hospital, precise information must be found using the Internet and the patient should be referred without any delay.
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<b>Objective:</b> The aim of the present study was to consider the importance of medical information obtained via the Internet for difficult cases in hospitals, especially in those located in rural areas. We report here a case of congenital arteriovenous fistula (AVF) in the upper extremities. <br><b>Patient:</b> A 30-year-old lady was transported to our hospital by ambulance due to massive bleeding in her left hand. She was seen by our current cardiovascular surgery team for the first time, although she had been diagnosed with congenital AVF of the left arm 9 years previously. Because it was asymptomatic, she was followed up by observation. During 5 years of observation, symptoms such as cyanosis, pain, and refractory ulcers gradually developed. When she was 26 years old, she was referred to a university hospital in Akita, but surgery had already been judged to be impossible. When she was 30 years old, traumatic bleeding in her left hand and hemorrhagic shock led her to be taken to our hospital by ambulance. Using the Internet, we found an institution that had treated a large number of cases of AVF. After controlling the bleeding, we referred her to that institution. However, she could not be treated without an above-elbow amputation. <br><b>Conclusion:</b> Congenital AVF in the upper extremities is a rare vascular anomaly and has been generally accepted to be an extremely difficult disease to treat. Treatment should be started as early as possible before the presence of any symptoms. When a specialist is not available near the hospital, precise information must be found using the Internet and the patient should be referred without any delay.
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Intracranial pial arteriovenous fistulas (AVFs) are rare vascular lesions of the brain. These lesions consist of one or more arterial connection to a single venous channel without true intervening nidus. A 24-year-old woman visited to our hospital because of headache, vomiting, dizziness and memory disturbance that persisted for three days. She complained several times of drop attack because of sudden weakness on both leg. Cerebral angiograms demonstrated a giant venous aneurysm on right frontal lobe beyond the genu of corpus callosum, multiple varices on both frontal lobes fed by azygos anterior cerebral artery, and markedly dilated draining vein into superior sagittal sinus, suggesting single channel pial AVF with multiple varices. Transarterial coil embolization of giant aneurysm and fistulous portion resulted in complete disappearance of pial AVF without complication.
Subject(s)
Female , Humans , Young Adult , Aneurysm , Anterior Cerebral Artery , Arteriovenous Fistula , Brain , Corpus Callosum , Dizziness , Embolization, Therapeutic , Frontal Lobe , Headache , Leg , Memory , Superior Sagittal Sinus , Syncope , Varicose Veins , Veins , VomitingABSTRACT
Vascular access is the prerequisite and mainstay of extra-corporeal renal replacement therapy and its management is central to maintain the health and quality of life of end-stage renal disease (ESRD) patients. Success of maturation of AVF depends on the quality and size of the vessels and anatomic structure. There have been several reports on non-maturation by vascular stenosis or small vascular size after AVF procedure, but reports demonstrating that AVF non-maturation is due to by latent vessel variation are uncommon. We report a rare case of scalp edema and insufficient maturation of AVF due to cephalic vein variation in a 27 year-old female patient with ESRD on hemodialysis. Conclusively, meticulous observation on not only vessels used for AVF but also its proximal connection to other vessels should be considered.
Subject(s)
Adult , Female , Humans , Arteriovenous Fistula , Constriction, Pathologic , Edema , Kidney Failure, Chronic , Quality of Life , Renal Dialysis , Renal Replacement Therapy , Scalp , VeinsABSTRACT
PURPOSE: We designed this study to find out the risk factors affecting the patency rate after creation of an arteriovenous fistula (AVF) for hemodialysis. METHODS: Between March 1997 and December 2001, a total of 397 AVF operations in 314 patients were performed by a single surgeon using the same surgical technique and principles. One hundred and forty cases (35.3%) were reoperations due to previous AVF failure. Artificial vessels (=PTFE, polytetrafluoroethylene) were used for the AVF in 39 cases (9.8%). The sex, age, diabetes mellitus, previous operation history and type of dialysis center were considered as a possible risk factors affecting the patency rate. RESULTS: After a mean follow-up of 18.3 months, there were 63 cases of patient death, 15 of kidney transplantation, and 104 of AVF failure identified. The overall patency rates of 1, 2 and 3 year were 76.2, 70.9, and 66.9%, respectively. From the multivariate analysis, the previous operation history was the only significant factor affecting the patency rate of AVF (P=0.001, odd ratio=2.58). Although the diabetic patient (odd ratio=1.43) and artificial vessel groups (odd ratio=1.678) showed high odd ratios, these factors were not statistically significant (P>0.05). From the univariate analysis, the reoperation cases also showed a significantly inferior patency rate compared to the first operation cases (1 year patency rate was 65.2% and 83.7%, P=0.001). However, the diabetes and types of vessel showed no significant differences in patency rates. CONCLUSION: A reoperation of an AVF creation was the most significant risk factor affecting the patency rate after its original creation. The first attempt AVF creations showed-favorable patency rates. To improve the overall patency rate of an AVF creation, a more delicate preoperative study and accurate surgical technique will be required at the time of the first AVF operation.
Subject(s)
Humans , Arteriovenous Fistula , Diabetes Mellitus , Dialysis , Follow-Up Studies , Kidney Transplantation , Multivariate Analysis , Renal Dialysis , Reoperation , Risk FactorsABSTRACT
Objective To evaluate the application value of detachable balloon in today's interventional neuroradiology. Methods 38 cases with vascular lesion in the area of cranial cervical region ( 26 cases with CCF, 3 with giant aneurysm in the cavernous segment of internal carotid artery, one with fusiform aneurysm in internal carotid artery, and 8 with AVF in the area of cranial cervical) were treated by detachable balloon for embolizing the shunt or scrificing the lesion ipsilateral internal carotid artery. Results All 38 cases were cured without complication and sequeulae. Of them, anatomical cure was aquired in 21 cases, lesion cure in 17 cases. Conclusions Detachable balloon is still the first choice of embolization material in today's endovascular therapy of some vascular lesions in the area of cranial cervical region.
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Este estudo quantitativo tem como objetivo verificar a associação entre a ocorrência de complicações funcionais da fístula arteriovenosa (FAV) estenose e pseudoaneurismas, com as técnicas de manuseio da FAV pela equipe de enfermagem com o tempo de maturação da FAV na primeira punção, a distância mantida entre a punção arterial e venosa e o rodízio do local de punção. Foi realizada uma análise de diálise com 146 pacientes em programa de hemodiálise crônica na cidade de São Paulo. A amostra foi constituída por 40 pacientes em programa de hemodiálise com FAV realizada pela técnica de Cimino-Brescia com um mínimo de um ano de uso, com idade entre 20 e 65 anos, não diabéticos. A coleta de dados foi realizada através de avaliação física e clínica dos 40 pacientes da amostra pela pesquisadora. Destes 40 pacientes, 23 eram homens e 17 mulheres, tendo como diagnóstico de base a nefroesclerose maligna em 19 e glomerulonefrite crônica em 14. Em relação ao número de confecção do acesso vascular, 24 pacientes (60%) tinham ainda a primeira FAV, sendo que destas, 27 estavam em região tabaqueira anatômica, e destas 20 em braço não dominante. O tempo médio de maturação da FAV na primeira foi de 21 dias, e a média das distâncias entre as punções arterial e venosa foi de 12 cm. Da amostra, 39 pacientes apresentaram cicatrizes de punções repetidas. As complicações encontradas foram 28 pseudoaneurismas e 7 estenoses. Na avaliação clínica das FAVs observou-se pressão venosa média de 124mmHg, fluxo de sangue de 350ml/min, e o teste de recirculação esteve abaixo de 10% em 38 pacientes. Os resultados do estudo sugerem que o tempo restrito destinado a maturação da FAV pode estar relacionado com a ocorrência de pseudoaneurisma e não de estenose apesar de não ter sido identificada significância estatística, e que a avaliação física de sinais de complicação funcional na FAV é uma estratégia significativa para o acompanhamento e ) detecção precoce dessas alterações.
The aim of this quantitative study is to verify the association of functional complications in arteriovenous fistulae (AFV) - stenoses and pseudoaneurysms - with the management techniques for AVF employed by nursing teams, such as: the time afforfed for maturation of the AVF before the first punch; the distance maintained between the arterial and venous punches; and rotation of the punch location. The study was carried out at a dialysis unit with 146 patients in chronic hemodialysis programs in the city of São Paulo. The sample was composed of 40 patients in hemodialysis programs, having had Cimino-Brescia fistulae used for at least one year, between 20 and 65 years of age, non diabetic. The data were collected by the author, through physical and clinical evaluation of the 40 sample patients. Of these 40 patients, 23 were men and 17 were women. The base diagnosis was malignant nephrosclerosis for 19 patients and chronic glomerulonephritis dor 14 patients. As for the number of times the vascular access had been made, 24 patients (60%) still had their fisrst AVF. Of these, 27 were in the anatomic snuffbox region, and 20 of these were on the non dominant arm. The average maturation time of the first AVF was 21 days, and the average distance between the arterial and venous punches was 12 cm. Of the sample, 39 patients had scars from repeated punches. The complications observed were 28 pseudoaneurysms and 7 stenoses. At the clinical evaluation of the AVFs, the average venous pressure observed was 124mmHg, the blood flow was 350ml/min, and the recirculation test results were below 10% in 38 patients. The results of the study suggest that the short time afforded for AVF maturation may be related with the occurence of pseudoaneurysms, but not with the occurence of stenoses, although no statistical significance was found, and that the physical evaluation of functional complications signs in AVF is a significant strategy for early detection and following of these abnormalities.
Subject(s)
Arteriovenous Fistula/complications , Nephrology Nursing , Renal DialysisABSTRACT
Effectively functioning arterio-venous fistula (AVF) is so important as to be called a lifeline of the patient with end stage renal disease by maintaining hemodialysis. Not infrequent development of complications of AVF is a major cause of patient's admission and medical cost. Rescue therapy of complicated AVF had several advantages; delay or prevention of new AVF formation, prevention of temporary percutaneous central vein cannulation, and maintenance of psychologic stability. PURPOSE: In order to analyse the patterns of AVF complications and the short- and long-term results of rescue therapy, we made a clinical review retrospectively. PATIENTS & METHODS: We performed AVF in 1503 cases from Jan. 1986 to Dec. 1997. Among them, we performed 93 rescue therapies in 70 patients. Rescue therapy is defined to be a secondary procedure to correct complications while maintaining the primary anastomosis. Secondary procedures in immediate postoperative failure due to technical cause, such as improper selection of vein, were excluded. RESULTS: The most common indication of rescue therapy in 93 cases was thrombosis (78 cases, 83.9%), which is followed by aneurysm in 9 cases, venous hypertension in 2 cases, steal syndrome in 2 cases, high output cardiac failure in 1 case. Autogenous veins were used in initial operation in 55 cases and PTFEs in 38 cases. Early failure within 1 month after rescue therapy happened in 20 cases (21.5%). Complications occured in 4 cases, such as infection (2), brachial plexus injury (1), and arm edema. (1) Mean follow up duration was 3.9 months (1~123 months). Secondary patency rate after 3, 6, 12, 24 months were 70.3+/-3.97, 62.0+/-4.89, 50.6+/-5.85, 37.9+/-7.03% respectively. Secondary patency rate in successfully rescued patients excluding early failure within 1 month after rescue therapy were 91.5+/-3.11, 80.9+/-4.46, 68.9+/-6.15, 54.1+/-8.19%. CONCLUSIONS: Thrombosis or malfunction due to neointimal hyperplasia was the most common complication in AVF. Early and proper rescue therapy in complicated fistula could salvage the AVF. So careful and prompt evaluation of the inflow and outflow of the complicated fistula is necessary, and every effort to rescue the fistula should be made.
Subject(s)
Humans , Aneurysm , Arm , Brachial Plexus , Catheterization , Edema , Fistula , Follow-Up Studies , Heart Failure , Hyperplasia , Hypertension , Kidney Failure, Chronic , Polytetrafluoroethylene , Renal Dialysis , Retrospective Studies , Thrombosis , VeinsABSTRACT
The most common limiting factor in arterio-venous fistula operation (AVF) is the lack of a suitable native vein. So preoperative assessment of venous system is essential for successful results. But simple physical examination alone is not enough to assess in many cases. To evaluate difference between venogram results with physical examination, 20 patients (group A) imaged with venogram preoperatively compared with 20 patients (group B) who examined only physically. In group A, all patients palpated thrill in immediate post operation and one patient revealed fistula occlusion within post operative 2 months. In group B 4 patients revealed failed fistula within 24 hours and 5 fistula failed in 2 months. Twelve patients (>50%) of group A showed different results in venogram compared with physical examination, which influenced type of operation. Physical examination alone was not enough to assess venous system and venogram provided valuable information in AVF constructive surgery.
Subject(s)
Humans , Fistula , Physical Examination , VeinsABSTRACT
BACKGROUND: When it is difficult to insure adequate blood vessels, an expanded polytetrafluoroethylene (e-PTFE) graft has been accepted as an alternative although its long-term patency is not equal to that of an autogenous arteriovenous fistula (AVF) for the purpose of performing hemodialysis. There being no hemodynamic guidelines for creating an autogenous or e-PTFE AVF, we prospectively investigated the difference in blood flows between autogenous and e-PTFE AVFs after internal AVF creation in order to identify an ideal AVF. METHODS: We performed color doppler ultrasonography on 15 patients who experienced AVF creation between December 1997 and December 1998 at the Wallace Memorial Baptist Hospital in Pusan and compared the volume flow per minute, the peak systolic velocity, and the cross-sectional area between an autogenous and an e-PTFE AVF. RESULTS: Eight (8) patients experienced an autogenous vein AVF creation, and seven (7) patients experienced an AVF creation using 4x6 mm graded e-PTFE (Impra(R)). 1. Average volume flow: 1611.87 +/-687.52 mL/min for autogenous AVFs and 1725.28+/-269.06 mL/min for e-PTFE AVFs (p=0.67). 2. Average peak systolic velocity: 128.98+/-52.83 cm/sec for autogenous AVFs and 81.71+/-8.93 cm/sec in e-PTFE AVFs (p=0.04). 3. Average cross-sectional area: 0.23+/-0.10 cm2 for autogenous AVFs and 0.34+/-0.02 cm2 for e-PTFE AVFs (p=0.02). 4. There were no postoperative complications, such as venous hypertension or distal ischemia, except for one puncture-site infection. CONCLUSIONS: There was no significant difference in volume flows between autogenous AVFs and 4x6 mm graded e-PTFE graft AVFs after internal AVF creation. In the e-PTFE graft AVFs, the cross-sectionalarea was greater and the peak systolic velocity was smaller compared with those of autogenous AVFs. These results suggest that, in e-PTFE AVF creation in order to maintain on adequate minute volume flow, it is important to minimized the cross-sectional area of the outflow vessel where the lower compliance of the e-PTFE graft increases outflow resistance. Also, we conclude that choosing the appropriate blood vessels and using a meticulous surgical technique are mandatory in establishing optimal hemodynamics for arteriovenous fistulae.