Ruptured venous aneurysm associated with a dural arteriovenous fistula:Two case reports

BACKGROUND In general,venous aneurysm associated with dural arteriovenous fistula(dAVF)is considered to be developed under long standing venous hypertension and manifested as venous ectasia of draining vein itself.However,discrete saccular shaped venous aneurysm without angiographic evidence of venous hypertension arising from the draining vein,like cerebral arterial aneurysm,is quite rare and its pathomechanism remains unclear in patients with dAVF.CASE SUMMARY In this report,we present two cases of ruptured saccular venous aneurysms associated with dAVF without venous hypertension or venous ectasia.In both cases,significant curve or stenosis is observed in draining vein,which is located in just distal portion of the venous aneurysms.These aneurysms were successfully treated with a transarterial embolization.Underlying mechanism of venous aneurysms in these cases is discussed.CONCLUSION Although there is little doubt that hemodynamic stress has a critical role in the development of venous aneurysms in patients with dAVF,preceding venous hypertension or venous ectasia is not necessary for development and enlargement of venous aneurysms.Considering the significant risk of rupture,a careful review of draining vein features including tortuosity or stenosis is needed,especially in venous aneurysms without evidence of venous hypertension.

Application of Clinical Care Pathway in Perioperative Patients with Autologous Arteriovenous Fistula Balloon Expansion

[Objective] To explore the effect of clinical care pathways in perioperative patients with autologous arteriovenous fistula balloon expansion. [Method] 202 patients undergoing autologous arteriovenous fistula from July 2021 to June 2022 were randomly divided into a control group (101 cases) and an observation group (101 cases) to compare the incidence rates of postoperative complications, hospitalization days, hospitalization expenses, knowledge of self-management of arteriovenous fistula and nursing satisfaction. [Results] In the observation group, the incidence of arteriovenous fistula was higher than that of the control group, and the hospitalization days and hospitalization costs were lower than that of the control group. The difference between the two groups was statistically significant (P < 0.05). [Conclusion] The application of the clinical nursing path to intervene in patients with autologous arteriovenous fistula balloon dilation can reduce the incidence of postoperative complications, shorten the hospital length of time, reduce hospitalization costs and improve patient satisfaction, which is clinical promotion significance.

Impact of stage-specific limb function exercises guided by a selfmanagement education model on arteriovenous fistula maturation status

BACKGROUND The exercise of limb function is the most economical and safe method to promote the maturation of arteriovenous fistula(AVF).However,due to the lack of a uni-fied exercise standard in China,many patients have insufficient awareness of the importance of AVF,leading to poor effectiveness of limb function exercise.The self-management education model can effectively promote patients to take pro-active health-related actions.This study focuses on the characteristics of patients during the peri-AVF period and conducts a phased limb function exercise under the guidance of the self-management education model to observe changes in fac-tors such as the maturity of AVF.AIM To assess the impact of stage-specific limb function exercises,directed by a self-management education model,on the maturation status of AVFs.METHODS This study is a randomized controlled trial involving 74 patients with forearm AVFs from the Nephrology Department of a tertiary hospital in Sichuan Province,China.Patients were randomly divided into an observation group and a control group using a random number table method.The observation group underwent tailored stage-specific limb func-tion exercises,informed by a self-management education model which took into account the unique features of AVF at various stages,in conjunction with routine care.Conversely,the control group was given standard limb function exercises along with routine care.The assessment involves the maturity of AVFs post-intervention,post-operative complications,and the self-management level of the fistula in both groups patients.Analyses were conducted using SPSS version 23.0.Count data were represented by frequency and percentage and subjected to chi-square test comparisons.Measurement data adhering to a normal distribution were presented as mean±SD.The independent samples t-test was utilized for inter-group comparisons,while the paired t-test was used for intra-group comparisons.For measurement data not fitting a normal distribution,the median and interquartile range were presented and analyzed using the Wilcoxon rank sum test.RESULTS At the 8-wk postoperative mark,the observation group demonstrated significantly higher scores in AVF symptom recognition,symptom prevention,and self-management compared to the control group(P<0.05).However,the variance in symptom management scores between the observation and control groups lacked statistical signi-ficance(P>0.05).At 4 wk after the operation,the observation group displayed a superior vessel diameter and depth from the skin of the drainage vessels in comparison to the control group(P<0.05).While the observation group did manifest elevated blood flow rates in the drainage vessels relative to the control group,this distinction was not statistically significant(P>0.05).By the 8-wk postoperative interval,the observation group outperformed the control group with notable enhancements in blood flow rates,vessel diameter,and depth from the skin of drainage vessels(P<0.01).Seven days following the procedure,the observation group manifested significantly diminished limb swelling and an overall reduced complication rate in contrast to the control group(P<0.05).The evaluation of infection,thrombosis,embolism,arterial aneurysm stenosis,and incision bleeding showed no notable differences between the two groups(P>0.05).By the 4-wk postoperative juncture,complications between the observation and control groups were statistically indistinguishable(P>0.05).CONCLUSION Stage-specific limb function exercises,under the guidance of a self-management education model,amplify the capacity of AVF patients to discern and prevent symptoms.Additionally,they expedite AVF maturation and miti-gate postoperative limb edema,underscoring their efficacy as a valuable method for the care and upkeep of AVF in hemodialysis patients.

The Preventive Effect of Comprehensive Nursing Intervention on Arteriovenous Fistula Failure in Patients in the Hemodialysis Room

Objective:To explore the preventive effect of comprehensive nursing intervention on arteriovenous fistula failure in patients in the hemodialysis room.Methods:82 patients with arteriovenous fistula in the hemodialysis chamber treated in our hospital from July 2022 to October 2023 were selected as the research subjects.The random number table method divided them into a control group and an experimental group of 41 cases each.The control group received general nursing intervention measures,while the experimental group underwent comprehensive nursing intervention.The incidence of complications(internal fistula failure,bleeding,thrombosis,infection),psychological emotions(SAS scale,SDS scale),quality of life(physical pain,physiological function,emotional function,social function),and nursing satisfaction(very satisfied,basically satisfied,satisfied,dissatisfied)were compared between the two groups of patients.Results:The incidence of complications in the experimental group(4,9.76%)was significantly lower than that in the control group(29,70.73%);the SAS scores and SDS scores of the patients in the experimental group after intervention were both lower than those in the control group;the quality of life score(physical pain,physiological function,emotional function,and social function)was all higher than those of the control group;the post-intervention nursing satisfaction of the experimental group(40,97.57%)was also significantly higher than that of the control group(29,73.17%);and the listed differences were statistically significant(P<0.01).Conclusion:For patients with hemodialysis ventricular arteriovenous fistula failure,comprehensive nursing intervention can reduce the incidence of complications,relieve anxiety and stress,improve quality of life and nursing satisfaction,and achieve better preventive effects.

Oral bacteria-associated liver abscess in conjunction with pulmonary arteriovenous fistula:a case report

Pulmonary arteriovenous fistul a(PAVF)represents an abnormal direct connection between the pulmonary artery and vein,circumventing the alveolar capillary network.A right-to-left shunt in the lungs precluding proper gas exchange and reduces pulmonary capillary filtration.

Splenic arteriovenous fistula and sudden onset of portal hypertension as complications of a ruptured splenic artery aneurysm: Successful treatment with transcatheter arterial embolization. A case study and review of the literature

Splenic arteriovenous fistula （SAVF） accounts for an unusual but well-documented treatable cause of portal hypertension. A case of a 50-year-old multiparous female who developed suddenly portal hypertension due to SAVF formation is presented. The patient suffered from repeated episodes of haematemesis and melaena during the past twelve days and thus was emergently admitted to hospital for management. Clinical and laboratory investigations established the diagnosis of portal hypertension in the absence of liver parenchymal disease. Endoscopy revealed multiple esophageal bleeding varices. Abdominal computed tomography （CT） and transfemoral celiac arteriography documented the presence of a tortuous and aneurysmatic splenic artery and premature filling of an enlarged splenic vein, findings highly suggestive of an SAVF. The aforementioned vascular abnormality was successfully treated with percutaneous transcatheter embolization. Neither recurrence nor other complications were observed.

Combined functional and anatomical diagnostic endpoints for assessing arteriovenous fistula dysfunction

Failure of arteriovenous fistulas(AVF) to mature and thrombosis in matured fistulas have been the major causes of morbidity and mortality in hemodialysis patients. Stenosis, which occurs due to adverse remodeling in AVFs, is one of the major underlying factors under both scenarios. Early diagnosis of a stenosis in an AVF can provide an opportunity to intervene in a timelymanner for either assisting the maturation process or avoiding the thrombosis. The goal of surveillance strategies was to supplement the clinical evaluation(i.e., physical examination) of the AVF for better and earlier diagnosis of a developing stenosis. Surveillance strategies were mainly based on measurement of functional hemodynamic endpoints, including blood flow(Q a) to the vascular access and venous access pressure(VAP). As the changes in arterial pressure(MAP) affects the level of VAP, the ratio of VAP to MAP(VAPR = VAP/MAP) was used for diagnosis. A Q a < 400-500 m L/min or a VAPR > 0.55 is considered sign of significant stenosis, which requires immediate intervention. However, due to the complex nature of AVFs, the surveillance strategies have failed to consistently detect stenosis under different scenarios. VAPR has been primarily developed to detect outflow stenosis in arteriovenous grafts, and it hasn't been successful in accurate diagnosis of outflow lesions in AVFs. Similarly, AVFs can maintain relatively high blood flow despite the presence of a significant outflow stenosis and thus, Q a has been found to be a better predictor of only inflow lesions. Similar shortcomings have been reported in the detection of functional severity of coronary stenosis using diagnostic endpoints that were based on either flow or pressure. This limitation has been associated with the fact that both pressure and flow change in the presence of a stenosis and thus, hemodynamic diagnostic endpoints that employ only one of these parameters are inherently prone to inaccuracies. Recent attempts have resulted in development of new diagnostic endpoints that can combine the effects of pressure and flow. These new hemodynamic diagnostic endpoints have shown to be better predictors of functional severity of lesions as compared to either flow or pressure based counterparts. In this review article, we discussed the advantages and limitations of current functional and anatomical diagnostic endpoints in AVFs.

Melena-associated regional portal hypertension caused by splenic arteriovenous fistula

Regional portal hypertension is a rare cause of upper gastrointestinal bleeding.We reported an extremely rare case in which regional portal hypertension was associated with both the splenic arteriovenous fistula and chronic pancreatitis.In June 2010,our patient,a 41-year-old man,was admitted to a local hospital due to a sudden melena and dizziness without haematemesis and jaundice.The splenic arteriovenous fistula in this patient was successfully occluded through transcatheter arterial embolization.At the 12-mo follow-up,our patient was in good condition.

Overview of multimodal MRI of intracranial Dural arteriovenous fistulas

Dural arteriovenous fistulas(DAVFs)include a wide range of pathological conditions that are associated with intracranial vessel abnormalities.While some types of DAVFs present with typical neuroimaging characteristics,others share overlapping pathological and neuroimaging features that can hinder accurate differentiation.Hence,misclassification of the various types of DAVFs is common.Thorough knowledge of DAVF imaging findings is essential to avoid such misinterpretations.Traditional digital subtraction angiography(DSA)is considered the gold standard for diagnosing and evaluating DAVFs.However,angiography cannot detect changes in a patient’s brain structure.Conventional magnetic resonance imaging(MRI)sequences,including MR angiography(MRA),allow the evaluation of DAVFs without ionizing radiation or invasiveness.Advanced MRI techniques,such as susceptibility-weighted imaging(SWI)and dynamic contrast-enhanced MRA,provide added value to real-time physio-pathological data regarding the hemodynamics of DAVFs.Beyond these techniques,new insights using high-resolution vascular wall MRI are incorporated for the noninvasive evaluation of DAVFs.This article reviews the pathophysiology of DAVFs,focusing on the specifics of MRI findings that facilitate their classification.The role of conventional and advanced MRI sequences for DAVFs was assessed using insights derived from the data provided by structured reports of multimodal MRIs to evaluate DAVFs.

Optimization of Maturation of Radio-Cephalic Arteriovenous Fistula Using a Model Relating Energy Loss Rate and Vascular Geometric Parameters

The main reason for the early failure of radio-cephalic arteriovenous fistula (RCAVF) is non-maturity, which means that the blood flow rate in the fistula cannot increase to the expected value for dialysis. From a mechanical perspective, the vascular resistance at the artificially designed anastomosis causes an energy loss that affects blood flow rate growth and leads to early failure. This research studied how to maximize the RCAVF maturity and primary patency by controlling the energy loss rate. We theoretically analyzed and derived a model that evaluates the energy loss rate Eavf in RCAVF as a function of its blood vessel geometric parameters (GPs) for given flow rates. There was an aggregate of five controllable GPs in RCAVF: radial artery diameter (Dra), cephalic vein diameter (Dcv), blood vessel distance between artery and vein (h), anastomotic diameter (Da), and anastomotic angle (θ). Through this analysis, it was found that Eavf was inversely proportional to Dra, Dcv, Da, and θ, whereas proportional to h. Therefore, we recommended surgeons choose the vessels with large diameters, close distance, and increase the diameter and angle of the anastomosis to decrease the early failure of RCAVF. Simultaneously, we could explain the results of many clinical empiricisms with our formula. We found that increasing Dcv and θ was more significant in reducing Eavf than increasing Dra and Da. Based on our model, we could define two critical energy loss rates (CELa, CELb) to help surgeons evaluate the blood vessels and choose the ideal range of θ, and help them design the preoperative RCAVF plan for each patient to increase the maturity and the primary patency of RCAVF.

Transvenous injection of n-Butyl cyanoacrylate combined with placement of coils in cavernous sinus for treatment of cavernous dural arteriovenous fistulae

Objective： To evaluate the technical aspects, efficacy and safety in the treatment of cavernous dural arteriovenous fistulae （DAVF） by transvenous liquid n-Butyl cyanoacrylate （NBCA） injection combined with coils placement in the cavemous sinus. Methods： Eight patients with cavernous DAVF, treated by transvenous embolization with combination of detachable coils and glue between February 2006 and February 2009 in our hospital, were retrospectively analyzed, including the clinical presentations, patterns of angioarchitecture, methods of treatment and the results of follow-up. Results： In all 8 patients, 9 transvenous and 1 transarterial interventions were carried out. A single endovascular procedure was performed in 6 patients and 2 patients had to be treated twice. Of the nine transvenous approaches, eight approaches were performed via inferior petrosal sinus （IPS） and 1 via the facial vein. Complete angiographic obliteration was achieved in all patients immediately after the embolization. There was no procedure-related morbidity except for mild headache for one to seven days after the embolization. Clinical cure was achieved in all cases during the clinical follow-up periods, ranging from 8 months to 3 years. The follow-up angiography periods averaged 6.6 months with a range of 5-9 months, in which no recurrence was observed. Conclusion： In this small series, embolization with combination of glue and detachable coils by transvenous approaches was a safe, effective and economical method for the treatment of part of symptomatic patients presenting with complex cavernous DAVE

Transvenous embolization of dural arteriovenous fistula of cavernous region by multiple venous routes

Objective：To evaluate the safety and efficiency of transvenous embolization of dural arteriovenous fistula of cavernous region by multiple venous routes. Methods： Twenty seven patients with dural arteriovenous fistula of cavernous region were treated by transvenous embolization with micro-coils. The transvenous routes included inferior petrosal sinus, superior ophthalmic vein and facial vein. Results： Clinical cure was achieved in 23 cases and significant improvement of symptoms in 4 cases. Complete anglographic obliteration was documented in 22 patients （82%）. Residual shunting were left in 2 patients via pterygoid drainage and 1 case via inter-cavernous sinus, 2 cases via inferior petrosal sinus, disappeared one month later by manual compression carotid artery. Headache and vomiting were the most common symptoms after embolization. Three patients had diplopia and relieved within two months after embolization. There was no permanent procedure-related morbidity. The clinic follow up ranged from 5 months to 6 years, and there was not recurrence case. Conclusion： Transvenous embolization via different venous routes is a safe and efficient method for dural arteriovenous fistula of cavernous region treatment.

Transient ischemic attack induced by pulmonary arteriovenous fistula in a child:A case report

BACKGROUND Cerebral ischemic stroke is attributed to paradoxical cerebral embolism.Pulmonary arteriovenous fistula(PAVF)is a rare potential cause of cerebral ischemic stroke,and cerebral ischemic stroke induced by PAVF in children is rare.CASE SUMMARY We report a case of right PAVF that presented as a transient ischemic attack(TIA)in a 13-year-old boy.The patient underwent embolization therapy and remained clinically stable for 2 years after treatment.CONCLUSION TIA induced by PAVF in children is rare,lacks typical clinical manifestations,and should not be ignored.

Case Report: Post Lumbar Discectomy Acute Iliac Arteriovenous Fistula;Endovascular Management and Literature Review

Posterior approach lumbar disc surgeries (LDS) can be associated with serious iatrogenic vascular complications which could be a serious life threatening condition. We report a rare case of right sided acute iliac vessels iatrogenic arteriovenous fistula (IAVF) which was diagnosed and managed in 24 hours duration in a 45 years old healthy female who underwent surgical posterior approach L4-5 discectomy. Intraoperative, she developed sudden hypotension, tachycardia, wide pulse pressure and acute drop of hemoglobin level without obvious operative site bleeding which raise the index of suspicion of vascular injury and urge the team for doing emergency CT angiography (CTA), vascular and endovascular team consultation for digital subtraction angiography (DSA) and endovascular management. Endovascular stenting is nowadays the modality of choice of intervention. We provide case report with literature review.

Multimodal MRI diagnosis and transvenous embolization of a basicranial emissary vein dural arteriovenous fistula:A case report

A dural arteriovenous fistula(DAVF) is an abnormal linkage connecting the arterial and venous systems within the intracranial dura mater. A basicranial emissary vein DAVF drains into the cavernous sinus and the ophthalmic vein, similar to a cavernous sinus DAVF. Precise preoperative identification of the DAVF location is a prerequisite for appropriate treatment. Treatment options include microsurgical disconnection, endovascular transarterial embolization(TAE), transvenous embolization(TVE), or a combination thereof. TVE is an increasingly popular approach for the treatment of DAVFs and the preferred approach for skull base locations, due to the risk of cranial neuropathy caused by dangerous anastomosis from arterial approaches. Multimodal magnetic resonance imaging(MRI) can provide anatomical and hemodynamic information for TVE. The therapeutic target must be precisely embolized in the emissary vein, which requires guidance via multimodal MRI. Here, we report a rare case of successful TVE for a basicranial emissary vein DAVF, utilizing multimodal MRI assistance. The fistula had vanished, pterygoid plexus drainage had improved, and the inferior petrosal sinus had recanalized, as observed on 8-month follow-up angiography. Symptoms and signs of double vision, caused by abduction deficiency, disappeared. Detailed anatomic and hemodynamic assessment by multimodal MRI is the key to guiding successful diagnosis and treatment.

Onyx embolization of a spinal epidural hemorrhage caused by thoracic spinal epidural arteriovenous fistula:A case report and literature review

Spinal epidural hemorrhages(SEDH)caused by spinal epidural arteriovenous fistulas(SEAVFs)are rare;thus,their specific pathogenesis has not been explained.Furthermore,the standard treatment for SEAVFs has not yet been defined.Here we report the case of a 36-year-old Chinese man who experienced acute onset chest pain and tightness.His symptoms rapidly aggravated until the lower limbs were unable to support him.Spinal magnetic resonance angiography(MRA)revealed a localized SEAVF and a secondary spinal cord lesion at the T4 level.Digital subtraction angiography(DSA)confirmed the presence of the SEDH/SEAVF at the T3–4 level with the left radicular artery feeding the fistula.Based on DSA and MRA findings,SEDH,local spinal cord infarction,and spinal venous reflux disorder were conditionally diagnosed.Using the arterial route,Onyx-34 was injected into the fistula to embolize the feeding arteries and the venous system.Angiography was performed after the microcatheter was withdrawn,and no residual fistula or anterior spinal artery was observed.The six-week follow-up MRI showed acceptable healing of the SEAVF,and the patient improved neurologically.This case suggests that endovascular treatment with Onyx-34 embolization should be considered a promising treatment strategy for this type of complicated SEAVF.

A Computational Analysis of the Influence of Anastomosis Angle on Stenosis-Prone Locations during Radio-Cephalic Arteriovenous Fistula Maturation

In dialysis treatment, the radio-cephalic arteriovenous fistula (RCAVF) is a commonly used fistula, yet its low maturation rate remains a challenge. To enhance surgical outcomes, the relationship between stenosis-prone locations and RCAVF anastomosis angle is studied during maturation by developing two sets of RCAVF models for early (non-mature) and mature RCAVFs at five anastomosis angles. The impact of hemodynamics and wall shear stress (WSS) is examined to determine optimal anastomotic angles. Results indicate that acute angles produce more physiological WSS distributions and fewer disturbed regions, with early stenosis-prone regions located near the anastomosis that shift to the bending venous segment during remodeling. A pilot study comparing clinical and numerical results is conducted for validation.

Clinical features of bilateral multiple pulmonary arteriovenous fistulas with paroxysmal aphasia as the first symptom:a case report

Objective:to describe the clinical features of bilateral multiple pulmonary arteriovenous fistulas(PAF)with paroxysmal aphasia as the first symptom.Methods:we collected the clinical history and examination data of a patient with paroxysmal aphasia.In order to trace the etiology,we performed chest computed tomography(CT)and pulmonary CT angiography(CIA).Results:the patient had paroxysmal aphasia with dizziness,brain magnetic resonance imaging(MRI)showed cerebral infarction,the transcranial Doppler(TCD)foaming test was positive,transesophageal ultrasound showed no patent foramen ovale,and chest CT and CIA showed bilateral multiple PAF.Conclusion:bilateral multiple PAF are rare in clinic.When patients have paroxysmal neurological symptoms,the possibility of PAF leading to embolism should be considered.

Impact and Management under Extracorporeal Circulation of a Patient with Renal Insufficiency on Dialysis with a High-Flow Arteriovenous Fistula in the Cardiac Surgery Department of the Angers Teaching Hospital about a Case and Review of the Literature

Arteriovenous fistulas have a substantial impact on systemic hemodynamics, however their effect on extracorporeal circulation is not well understood. We report our clinical observation on the management under extracorporeal circulation of a patient with renal insufficiency with a high-flow arteriovenous fistula. This is a 59-year-old man who was referred to us for surgical treatment of ischemic coronary artery disease in a context of anuric chronic renal failure. Hypothermia at 32°C is started from the start in CEC due to hyperflow at the level of the arteriovenous fistula. We performed two coronary artery bypasses of the marginal and IVA via the two internal thoracic arteries. The patient is hemofiltered in order to avoid hyperkalaemia and possibly avoid fluid overload related to filling per CEC. The clamping time was 71 minutes and the SCC lasted 141 minutes. There was no homologous transfusion in the operating room. It turns out that the input/output balance is zero at the end of the CEC. The postoperative course was simple.

DSA analysis of hepatic arteriovenous fistula concurrent with hepatic cancer and its clinical significance

INTRODUCTIONIntervention therapy has become one of the maintherapies of hepatic cancer.Theintroduction of hepatic arterial perfusion andembolization has provided opportunities for asecondary operation on patients with intermediateand advanced cancer,thus