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 ha...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.展开更多
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...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.展开更多
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 PAV...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.展开更多
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 ophtha...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.展开更多
BACKGROUND A carotid-cavernous fistula(CCF)is an abnormal connection between the internal carotid artery(ICA)and the cavernous sinus.Although direct CCFs typically result from trauma or as an iatrogenic complication o...BACKGROUND A carotid-cavernous fistula(CCF)is an abnormal connection between the internal carotid artery(ICA)and the cavernous sinus.Although direct CCFs typically result from trauma or as an iatrogenic complication of neuroendovascular procedures,they can occur as surgery-related complications after mechanical thrombectomy(MT).With the widespread use of MT in patients with acute ischemic stroke complicated with large vessel occlusion,it is important to document CCF following MT and how to avoid them.In this study,we present a case of a patient who developed a CCF following MT and describe in detail the characteristics of ICA tortuosity in this case.CASE SUMMARY A 60-year-old woman experienced weakness in the left upper and lower limbs as well as difficulty speaking for 4 h.The neurological examination revealed left central facial paralysis and left hemiplegia,with a National Institutes of Health Stroke Scale score of 9.Head magnetic resonance imaging revealed an acute cerebral infarction in the right basal ganglia and radial crown.Magnetic resonance angiography demonstrated an occlusion of the right ICA and middle cerebral artery.Digital subtraction angiography demonstrated distal occlusion of the cervical segment of the right ICA.We performed suction combined with stent thrombectomy.Then,postoperative angiography was performed,which showed a right CCF.One month later,CCF embolization was performed,and the patient’s clinical symptoms have significantly improved 5 mo after the operation.CONCLUSION Although a CCF is a rare complication after MT,it should be considered.Understanding the tortuosity of the internal carotid-cavernous sinus may help predict the complexity of MT and avoid this complication.展开更多
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-pron...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.展开更多
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 extracor...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.展开更多
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...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展开更多
Arteriovenous fistulas between the inferior mesenteric artery and vein are rare, with only 26 primary and secondary cases described in the literature. Secondary fistulas occur following operations of the left hemicolo...Arteriovenous fistulas between the inferior mesenteric artery and vein are rare, with only 26 primary and secondary cases described in the literature. Secondary fistulas occur following operations of the left hemicolon and manifest as abdominal pain, abdominal mass, gastrointestinal bleeding, colonic ischemia and portal hypertension. Symptom intensities are flow-dependent, and can range from minimal symptoms to severe heart failure due to left to right shunt. Diagnosis is usually established by radiological or intraoperative examination. Treatment options include embolization and/or surgical resection. Therapeutic decisions should be adapted to the unique characteristics of the fistula on an individual basis. A new case of a primary arteriovenous fistula is described and discussed along with a complete review of the literature. The patient in this report presented with signs and symptoms of colonic ischemia without portal hypertension. The optimal treatment for this pa-tient required a combination of embolization and surgical operation. The characteristics of these rare inferior mesenteric arteriovenous fistulas are examined and some considerations concerning diagnostic and therapeutic strategies that should be followed are presented.展开更多
Splenic arteriovenous fistulas(SAVFs) with splenic vein aneurysms are extremely rare entities. There have been no prior reports of SAVFs developing after laparoscopic pancreatectomy. Here, we report the first case. A ...Splenic arteriovenous fistulas(SAVFs) with splenic vein aneurysms are extremely rare entities. There have been no prior reports of SAVFs developing after laparoscopic pancreatectomy. Here, we report the first case. A 40-year-old man underwent a laparoscopic, spleen-preserving, distal pancreatectomy for an endocrine neoplasm of the pancreatic tail. Three months after surgery, a computed tomography(CT) scan demonstrated an SAVF with a dilated splenic vein. The SAVF, together with the splenic vein aneurysm, was successfully treated using percutaneous transarterial coil embolization of the splenic artery, including the SAVF and drainage vein. After the endovascular treatment, the patient's recovery was uneventful. He was discharged on postoperative day 6 and continues to be well 3 mo after discharge. An abdominal CT scan performed at his 3-mo follow-up demonstrated complete thrombosis of the splenic vein aneurysm, which had decreased to a 40 mm diameter. This is the first reported case of SAVF following a laparoscopic pancreatectomy and demonstrates the usefulness of endovascular treatment for this type of complication.展开更多
BACKGROUND A hybrid operating room(hybrid-OR)is a surgical space that combines a conventional operating room with advanced medical imaging devices.AIM To explore and summarize the technical features and effectiveness ...BACKGROUND A hybrid operating room(hybrid-OR)is a surgical space that combines a conventional operating room with advanced medical imaging devices.AIM To explore and summarize the technical features and effectiveness of the application of a hybrid-OR in dealing with spinal dural arteriovenous fistulas(SDAVFs).METHODS Eleven patients with SDAVFs were treated with the use of a hybrid-OR at the Department of Neurosurgery of our hospital between January 2015 and December 2018.The dual-marker localization technique was used in the hybrid-OR to locate the SDAVFs and skin incision,and the interoperative digital subtraction angiography(DSA)technique was used before and after microsurgical ligation of the fistulae in the hybrid-OR to verify the accuracy of obliteration.The patients were followed for an average of 2 years after the operation,and the preoperative American Spinal Cord Injury Association(ASIA)score and postoperative ASIA score at 6 mo after the operation were compared.RESULTS The location and skin incision of the SDAVFs were accurately obtained by using the dual-marker localization technique in the hybrid-OR in all patients,and there were no cases that required expansion of the range of the bone window in order to expose the lesions.Intraoperative error obliteration occurred and was identified in two patients by using the intraoperative DSA technique;therefore,the findings provided by the intraoperative DSA system significantly changed the surgical procedure in these two patients.With the assistance of the hybrid-OR,the feeding artery was correctly ligated in all cases,and the intraoperative error obliteration rate decreased from 18.2%(2/11)to 0%.All 11 patients were followed for an average of 2 years.The ASIA score at 6 mo after the operation was significantly improved compared with the preoperative ASIA score,and there were no patients with late recurrence during the follow-up.CONCLUSION Compared with intra-arterial embolization for the treatment of SDAVFs,hybrid-ORs can solve the problem of a higher incidence of initial failure and late recurrence.Compared with direct occlusion of SDAVFs in microsurgery,hybrid-ORs can take advantage of the intraoperative DSA system for locating the shunt and verifying the obliteration of fistulae in order to reduce the error obliteration rate.At this point,our experience suggests that the safety and ease of use make hybrid-ORs combined with microsurgery and intraoperative DSA systems an attractive modality for dealing with SDAVFs.展开更多
Dural arteriovenous fistula(DAVF) is a rare type of cerebral arteriovenous malformation. Common presenting symptoms are related to hemorrhage. However, rarely these patients may present with myelopathy. We present two...Dural arteriovenous fistula(DAVF) is a rare type of cerebral arteriovenous malformation. Common presenting symptoms are related to hemorrhage. However, rarely these patients may present with myelopathy. We present two cases of DAVF presenting as rapidly progressive myelopathy. Two treatment options are available: microsurgical interruption of the fistula and endovascular embolization. These treatment options of DAVFs have improved significantly in the last decade. The optimal treatment of DAVFs remains controversial, and there is an ongoing debate as to whether primary endovascular or primary microsurgical treatment is the optimal management for these lesions. However, despite treatment a high percentage of patients are still left with severe disability. The potential for functional ambulation in patients with DAVF is related to the time of intervention. This emphasizes the important of early diagnosis and early intervention in DAVF. The eventual outcome may depend on several factors, such as the duration of symptoms, the degree of disability before treatment, and the success of the initial procedure to close the fistula. The usage of magnetic resonance imaging and selective angiography has significantly improved the ability to characterize DAVFs, however, these lesions remain inefficiently diagnosed. If intervention is delayed even prolonged time in rehabilitation does not change the grave prognosis. This review outlines the presentation, classication and management of DAVF as well as discussing patient outcomes.展开更多
Objective:Transarterial and transvenous embolization methods are considered effective and safe approaches for the treatment of cavernous sinus dural arteriovenous fistula(CSDAVF).Here.,we report the angioarchitectural...Objective:Transarterial and transvenous embolization methods are considered effective and safe approaches for the treatment of cavernous sinus dural arteriovenous fistula(CSDAVF).Here.,we report the angioarchitectural features and clinical outcomes of CSDAVF in patients treated with either the inferior arterial approach(IAA) or the inferior petrosal sinus approach(IPSA).Methods:The clinical data of 32 patients with CSDAVF treated at our institution from May 2008 to May 2014 were retrospectively analyzed.All patients underwent routine diagnostic digital subtraction angiography(DSA) before surgery.Embolization was performed using the IPSA through the internal jugular vein or IAA,based on angioarchitectural features.Results:Of the 32 patients with CSDAVF,24 underwent embolization treatment through the internal jugular veinIPSA and 8 patients underwent treatment through IAA.Nineteen patients in the IPSA group experienced mild headache,which improved after specific treatment.The immediate postembolization angiographic results revealed complete occlusion in 26 cases(18 IPSA and 8 IAA) and almost complete occlusion in 6 cases(IPSA).Complications that occurred during the procedure included abducens nerve palsy(n=1,IPSA) and prosopoplegia(n=1,IAA).One patient developed tinnitus,which was diagnosed as anterior cranial fossa new-onset dural arteriovenous fistula on DSA,whereas the symptoms of other patients all improved with no recurrence.Conclusions:On the basis of the angioarchitectural features of CSDAVF,IAA can be considered the primary treatment when the blood-supplying artery and fistula are relatively singular,and when the microcatheter can easily reach the fistula through the artery.The venous approach should be selected as the primary approach when the fistula is indistinguishable and blood is supplied by multiple arteries through small plexiform vessels.Choosing the optimal surgical approach may increase the success rate of intravascular CSDAVF surgery and may help avoid complications.展开更多
Objective: To evaluate the effectiveness of cryotherapy in managing the pain at the puncture site of Arterio-Venous Fistula (AVF) among children undergoing maintenance hemodialysis (HD).Methods: A one-group pre-post q...Objective: To evaluate the effectiveness of cryotherapy in managing the pain at the puncture site of Arterio-Venous Fistula (AVF) among children undergoing maintenance hemodialysis (HD).Methods: A one-group pre-post quasi-experiment was performed in two HD centers affiliated with Cairo University.The experiment involved 40 children with AVF undergoing HD.Before puncturing,cryotherapy was applied using 2 cm-3 cm pieces of frozen distilled water in a plastic bag.Pain was assessed subjectively and objectively in two dialysis sessions before and after cryotherapy.A part from a physiological assessment of vital signs,pain was assessed using the Wong-Baker Faces Pain and the Observed Pain Behavior rating scales.All research ethics were applied.Results: HD had a median duration of four years,while cryotherapy had a median application time of 8.8 min.The Wong-Baker Faces Pain score and almost all observed pain behaviors significantly decreased after cryotherapy.Significant improvements were observed in respiratory rate before and after needle puncture and in oxygen saturation after needle puncture.A lower skin dryness was observed after cryotherapy (12.5%) than before cryotherapy (52.5%;p < 0.001).Conclusions: Cryotherapy can effectively reduce the venipuncture pain among children with AVF undergoing maintenance HD.However,the confounding effects of distraction and the non-randomized design used must be both considered when interpreting the findings.This study recommends the use of cryotherapy in managing needle puncture pain.Further research must adopt a randomized trial design with a placebo to support further the benefits of this procedure.展开更多
An idiopathic renal arteriovenous(AV) fistula is a rare malformation of the kidney that may present insidiously with heart failure or hematuria.The treatment may be challenging due to large fistula size that may limit...An idiopathic renal arteriovenous(AV) fistula is a rare malformation of the kidney that may present insidiously with heart failure or hematuria.The treatment may be challenging due to large fistula size that may limit endovascular management.The authors report a case of an 85-year-old Caucasian woman who presented with acute heart failure and was found to have a right renal AV fistula.Since she had no prior history of renal intervention or trauma,a diagnosis of idiopathic renal AV fistula was made.She was managed by endoluminal occlusion using multiple stainless steel coils and Amplatzer vascular plug II device.The follow-up computed tomography showed complete occlusion of the fistula.This report highlights the late presentation of this rare disease and presents the utility of the combination of coils and Amplatzer device for management of a large fistula.It also reiterates that even if large,these fistulas can be managed by endovascular occlusion.展开更多
AIM: To discuss about the perioperative problems encountered in patients with internal biliary fistula (IBF) caused by cholelithiasis. METHODS: In our hospital, 4 130 cholecystectomies were carried out for symptomatic...AIM: To discuss about the perioperative problems encountered in patients with internal biliary fistula (IBF) caused by cholelithiasis. METHODS: In our hospital, 4 130 cholecystectomies were carried out for symptomatic cholelithiasis from January 2000 to March 2004 and only 12 patients were diagnosed with IBF. The perioperative data of these 12 IBF patients were analyzed retrospectively. RESULTS: The incidence of IBF due to cholelithiasis was nearly 0.3%. The mean age was 57 years. Most of the patients presented with non-specific complaints. Only two patients were considered to have IBF when gallstone ileus was observed during the investigations. Nine patients underwent emergency laparotomy with a pre-operative diagnosis of acute abdomen. In the remaining three patients, elective laparoscopic cholecystectomy was converted to open surgery after identification of IBF. Ten patients had cholecystoduodenal fistula and two patients had cholecystocholedochal fistula. The mean hospital stay was 13 d. Two wound infections, three bile leakages and three mortalities were observed. CONCLUSION: Cholecystectomy has to be performed in early stage in the patients who were diagnosed as cholelithiasis to prevent the complications like IBF which is seen rarely. Suspicion of IBF should be kept in mind, especially in the case of difficult dissection during cholecystectomy and attention should be paid in order to prevent iatrogenic injuries.展开更多
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 A...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.展开更多
<span style="font-family:Verdana;">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 incr...<span style="font-family:Verdana;">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 <em>E</em><sub><em>avf</em></sub> 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 (<em>D</em><sub><em>ra</em></sub>), cephalic vein diameter (<em>D</em><sub><em>cv</em></sub>), blood vessel distance between artery and vein (<em>h</em>), anastomotic diameter (<em>D</em><sub><em>a</em></sub>), and anastomotic angle (<em>θ</em>). Through this analysis, it was found that <em>E</em><sub><em>avf</em></sub> was inversely proportional to <em>D</em><sub><em>ra</em></sub>, <em>D</em><sub><em>cv</em></sub>, <em>D</em><sub><em>a</em></sub>, and <em>θ</em>, whereas proportional to <em>h</em>. 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 <em>D</em><sub><em>cv</em></sub> and <em>θ</em> was more significant in reducing <em>E</em><sub><em>avf</em></sub> than increasing <em>D</em><sub><em>ra</em></sub> and <em>D</em><sub><em>a</em></sub>. Based on our model, we could define two critical energy loss rates (<em>CEL</em><sub><em>a</em></sub>, <em>CEL</em><sub><em>b</em></sub>) to help surgeons evaluate the blood vessels and choose the ideal range of <em>θ</em>, and help them design the preoperative RCAVF plan for each patient to increase the maturity and the primary patency of RCAVF.</span>展开更多
Arteriovenous fistula (AVF) involving the inferior mesenteric vessels is rare, and the affected patients usually present with abdominal pain, mass, or features of established portal hypertension. Colonic ischemia is a...Arteriovenous fistula (AVF) involving the inferior mesenteric vessels is rare, and the affected patients usually present with abdominal pain, mass, or features of established portal hypertension. Colonic ischemia is a less common and more serious manifestation of AVF. We report a case of ischemic colitis secondary to inferior mesenteric AVF in a patient who underwent a previous liver transplantation, subsequently developed portal vein stenosis, and then presented with acute lower gastrointestinal bleeding. He underwent percutaneous transhepatic placement of a portal vein stent and left colectomy.展开更多
基金Supported by The Research Project 2022 of The People's Hospital of Jianyang City,No.JY202208.
文摘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.
文摘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.
基金Supported by Scientific Research Project of Hainan Provincial Health Industry,China,No.20A200081Clinical Medical Center Project of Hainan Province,China,No.QWYH202175.
文摘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.
基金funding from the National Natural Science Foundation of China (Grant No.81771242)the Shanghai Pujiang Program (Grant No.20PJ1402200)。
文摘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.
文摘BACKGROUND A carotid-cavernous fistula(CCF)is an abnormal connection between the internal carotid artery(ICA)and the cavernous sinus.Although direct CCFs typically result from trauma or as an iatrogenic complication of neuroendovascular procedures,they can occur as surgery-related complications after mechanical thrombectomy(MT).With the widespread use of MT in patients with acute ischemic stroke complicated with large vessel occlusion,it is important to document CCF following MT and how to avoid them.In this study,we present a case of a patient who developed a CCF following MT and describe in detail the characteristics of ICA tortuosity in this case.CASE SUMMARY A 60-year-old woman experienced weakness in the left upper and lower limbs as well as difficulty speaking for 4 h.The neurological examination revealed left central facial paralysis and left hemiplegia,with a National Institutes of Health Stroke Scale score of 9.Head magnetic resonance imaging revealed an acute cerebral infarction in the right basal ganglia and radial crown.Magnetic resonance angiography demonstrated an occlusion of the right ICA and middle cerebral artery.Digital subtraction angiography demonstrated distal occlusion of the cervical segment of the right ICA.We performed suction combined with stent thrombectomy.Then,postoperative angiography was performed,which showed a right CCF.One month later,CCF embolization was performed,and the patient’s clinical symptoms have significantly improved 5 mo after the operation.CONCLUSION Although a CCF is a rare complication after MT,it should be considered.Understanding the tortuosity of the internal carotid-cavernous sinus may help predict the complexity of MT and avoid this complication.
文摘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.
文摘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.
文摘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
文摘Arteriovenous fistulas between the inferior mesenteric artery and vein are rare, with only 26 primary and secondary cases described in the literature. Secondary fistulas occur following operations of the left hemicolon and manifest as abdominal pain, abdominal mass, gastrointestinal bleeding, colonic ischemia and portal hypertension. Symptom intensities are flow-dependent, and can range from minimal symptoms to severe heart failure due to left to right shunt. Diagnosis is usually established by radiological or intraoperative examination. Treatment options include embolization and/or surgical resection. Therapeutic decisions should be adapted to the unique characteristics of the fistula on an individual basis. A new case of a primary arteriovenous fistula is described and discussed along with a complete review of the literature. The patient in this report presented with signs and symptoms of colonic ischemia without portal hypertension. The optimal treatment for this pa-tient required a combination of embolization and surgical operation. The characteristics of these rare inferior mesenteric arteriovenous fistulas are examined and some considerations concerning diagnostic and therapeutic strategies that should be followed are presented.
文摘Splenic arteriovenous fistulas(SAVFs) with splenic vein aneurysms are extremely rare entities. There have been no prior reports of SAVFs developing after laparoscopic pancreatectomy. Here, we report the first case. A 40-year-old man underwent a laparoscopic, spleen-preserving, distal pancreatectomy for an endocrine neoplasm of the pancreatic tail. Three months after surgery, a computed tomography(CT) scan demonstrated an SAVF with a dilated splenic vein. The SAVF, together with the splenic vein aneurysm, was successfully treated using percutaneous transarterial coil embolization of the splenic artery, including the SAVF and drainage vein. After the endovascular treatment, the patient's recovery was uneventful. He was discharged on postoperative day 6 and continues to be well 3 mo after discharge. An abdominal CT scan performed at his 3-mo follow-up demonstrated complete thrombosis of the splenic vein aneurysm, which had decreased to a 40 mm diameter. This is the first reported case of SAVF following a laparoscopic pancreatectomy and demonstrates the usefulness of endovascular treatment for this type of complication.
基金the Tianjin Science and Technology Projects in Key Areas of Traditional Chinese Medicine,No.2018001.
文摘BACKGROUND A hybrid operating room(hybrid-OR)is a surgical space that combines a conventional operating room with advanced medical imaging devices.AIM To explore and summarize the technical features and effectiveness of the application of a hybrid-OR in dealing with spinal dural arteriovenous fistulas(SDAVFs).METHODS Eleven patients with SDAVFs were treated with the use of a hybrid-OR at the Department of Neurosurgery of our hospital between January 2015 and December 2018.The dual-marker localization technique was used in the hybrid-OR to locate the SDAVFs and skin incision,and the interoperative digital subtraction angiography(DSA)technique was used before and after microsurgical ligation of the fistulae in the hybrid-OR to verify the accuracy of obliteration.The patients were followed for an average of 2 years after the operation,and the preoperative American Spinal Cord Injury Association(ASIA)score and postoperative ASIA score at 6 mo after the operation were compared.RESULTS The location and skin incision of the SDAVFs were accurately obtained by using the dual-marker localization technique in the hybrid-OR in all patients,and there were no cases that required expansion of the range of the bone window in order to expose the lesions.Intraoperative error obliteration occurred and was identified in two patients by using the intraoperative DSA technique;therefore,the findings provided by the intraoperative DSA system significantly changed the surgical procedure in these two patients.With the assistance of the hybrid-OR,the feeding artery was correctly ligated in all cases,and the intraoperative error obliteration rate decreased from 18.2%(2/11)to 0%.All 11 patients were followed for an average of 2 years.The ASIA score at 6 mo after the operation was significantly improved compared with the preoperative ASIA score,and there were no patients with late recurrence during the follow-up.CONCLUSION Compared with intra-arterial embolization for the treatment of SDAVFs,hybrid-ORs can solve the problem of a higher incidence of initial failure and late recurrence.Compared with direct occlusion of SDAVFs in microsurgery,hybrid-ORs can take advantage of the intraoperative DSA system for locating the shunt and verifying the obliteration of fistulae in order to reduce the error obliteration rate.At this point,our experience suggests that the safety and ease of use make hybrid-ORs combined with microsurgery and intraoperative DSA systems an attractive modality for dealing with SDAVFs.
文摘Dural arteriovenous fistula(DAVF) is a rare type of cerebral arteriovenous malformation. Common presenting symptoms are related to hemorrhage. However, rarely these patients may present with myelopathy. We present two cases of DAVF presenting as rapidly progressive myelopathy. Two treatment options are available: microsurgical interruption of the fistula and endovascular embolization. These treatment options of DAVFs have improved significantly in the last decade. The optimal treatment of DAVFs remains controversial, and there is an ongoing debate as to whether primary endovascular or primary microsurgical treatment is the optimal management for these lesions. However, despite treatment a high percentage of patients are still left with severe disability. The potential for functional ambulation in patients with DAVF is related to the time of intervention. This emphasizes the important of early diagnosis and early intervention in DAVF. The eventual outcome may depend on several factors, such as the duration of symptoms, the degree of disability before treatment, and the success of the initial procedure to close the fistula. The usage of magnetic resonance imaging and selective angiography has significantly improved the ability to characterize DAVFs, however, these lesions remain inefficiently diagnosed. If intervention is delayed even prolonged time in rehabilitation does not change the grave prognosis. This review outlines the presentation, classication and management of DAVF as well as discussing patient outcomes.
文摘Objective:Transarterial and transvenous embolization methods are considered effective and safe approaches for the treatment of cavernous sinus dural arteriovenous fistula(CSDAVF).Here.,we report the angioarchitectural features and clinical outcomes of CSDAVF in patients treated with either the inferior arterial approach(IAA) or the inferior petrosal sinus approach(IPSA).Methods:The clinical data of 32 patients with CSDAVF treated at our institution from May 2008 to May 2014 were retrospectively analyzed.All patients underwent routine diagnostic digital subtraction angiography(DSA) before surgery.Embolization was performed using the IPSA through the internal jugular vein or IAA,based on angioarchitectural features.Results:Of the 32 patients with CSDAVF,24 underwent embolization treatment through the internal jugular veinIPSA and 8 patients underwent treatment through IAA.Nineteen patients in the IPSA group experienced mild headache,which improved after specific treatment.The immediate postembolization angiographic results revealed complete occlusion in 26 cases(18 IPSA and 8 IAA) and almost complete occlusion in 6 cases(IPSA).Complications that occurred during the procedure included abducens nerve palsy(n=1,IPSA) and prosopoplegia(n=1,IAA).One patient developed tinnitus,which was diagnosed as anterior cranial fossa new-onset dural arteriovenous fistula on DSA,whereas the symptoms of other patients all improved with no recurrence.Conclusions:On the basis of the angioarchitectural features of CSDAVF,IAA can be considered the primary treatment when the blood-supplying artery and fistula are relatively singular,and when the microcatheter can easily reach the fistula through the artery.The venous approach should be selected as the primary approach when the fistula is indistinguishable and blood is supplied by multiple arteries through small plexiform vessels.Choosing the optimal surgical approach may increase the success rate of intravascular CSDAVF surgery and may help avoid complications.
文摘Objective: To evaluate the effectiveness of cryotherapy in managing the pain at the puncture site of Arterio-Venous Fistula (AVF) among children undergoing maintenance hemodialysis (HD).Methods: A one-group pre-post quasi-experiment was performed in two HD centers affiliated with Cairo University.The experiment involved 40 children with AVF undergoing HD.Before puncturing,cryotherapy was applied using 2 cm-3 cm pieces of frozen distilled water in a plastic bag.Pain was assessed subjectively and objectively in two dialysis sessions before and after cryotherapy.A part from a physiological assessment of vital signs,pain was assessed using the Wong-Baker Faces Pain and the Observed Pain Behavior rating scales.All research ethics were applied.Results: HD had a median duration of four years,while cryotherapy had a median application time of 8.8 min.The Wong-Baker Faces Pain score and almost all observed pain behaviors significantly decreased after cryotherapy.Significant improvements were observed in respiratory rate before and after needle puncture and in oxygen saturation after needle puncture.A lower skin dryness was observed after cryotherapy (12.5%) than before cryotherapy (52.5%;p < 0.001).Conclusions: Cryotherapy can effectively reduce the venipuncture pain among children with AVF undergoing maintenance HD.However,the confounding effects of distraction and the non-randomized design used must be both considered when interpreting the findings.This study recommends the use of cryotherapy in managing needle puncture pain.Further research must adopt a randomized trial design with a placebo to support further the benefits of this procedure.
文摘An idiopathic renal arteriovenous(AV) fistula is a rare malformation of the kidney that may present insidiously with heart failure or hematuria.The treatment may be challenging due to large fistula size that may limit endovascular management.The authors report a case of an 85-year-old Caucasian woman who presented with acute heart failure and was found to have a right renal AV fistula.Since she had no prior history of renal intervention or trauma,a diagnosis of idiopathic renal AV fistula was made.She was managed by endoluminal occlusion using multiple stainless steel coils and Amplatzer vascular plug II device.The follow-up computed tomography showed complete occlusion of the fistula.This report highlights the late presentation of this rare disease and presents the utility of the combination of coils and Amplatzer device for management of a large fistula.It also reiterates that even if large,these fistulas can be managed by endovascular occlusion.
文摘AIM: To discuss about the perioperative problems encountered in patients with internal biliary fistula (IBF) caused by cholelithiasis. METHODS: In our hospital, 4 130 cholecystectomies were carried out for symptomatic cholelithiasis from January 2000 to March 2004 and only 12 patients were diagnosed with IBF. The perioperative data of these 12 IBF patients were analyzed retrospectively. RESULTS: The incidence of IBF due to cholelithiasis was nearly 0.3%. The mean age was 57 years. Most of the patients presented with non-specific complaints. Only two patients were considered to have IBF when gallstone ileus was observed during the investigations. Nine patients underwent emergency laparotomy with a pre-operative diagnosis of acute abdomen. In the remaining three patients, elective laparoscopic cholecystectomy was converted to open surgery after identification of IBF. Ten patients had cholecystoduodenal fistula and two patients had cholecystocholedochal fistula. The mean hospital stay was 13 d. Two wound infections, three bile leakages and three mortalities were observed. CONCLUSION: Cholecystectomy has to be performed in early stage in the patients who were diagnosed as cholelithiasis to prevent the complications like IBF which is seen rarely. Suspicion of IBF should be kept in mind, especially in the case of difficult dissection during cholecystectomy and attention should be paid in order to prevent iatrogenic injuries.
文摘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.
文摘<span style="font-family:Verdana;">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 <em>E</em><sub><em>avf</em></sub> 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 (<em>D</em><sub><em>ra</em></sub>), cephalic vein diameter (<em>D</em><sub><em>cv</em></sub>), blood vessel distance between artery and vein (<em>h</em>), anastomotic diameter (<em>D</em><sub><em>a</em></sub>), and anastomotic angle (<em>θ</em>). Through this analysis, it was found that <em>E</em><sub><em>avf</em></sub> was inversely proportional to <em>D</em><sub><em>ra</em></sub>, <em>D</em><sub><em>cv</em></sub>, <em>D</em><sub><em>a</em></sub>, and <em>θ</em>, whereas proportional to <em>h</em>. 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 <em>D</em><sub><em>cv</em></sub> and <em>θ</em> was more significant in reducing <em>E</em><sub><em>avf</em></sub> than increasing <em>D</em><sub><em>ra</em></sub> and <em>D</em><sub><em>a</em></sub>. Based on our model, we could define two critical energy loss rates (<em>CEL</em><sub><em>a</em></sub>, <em>CEL</em><sub><em>b</em></sub>) to help surgeons evaluate the blood vessels and choose the ideal range of <em>θ</em>, and help them design the preoperative RCAVF plan for each patient to increase the maturity and the primary patency of RCAVF.</span>
基金A grant from the National R & D Program for Cancer Control,Ministry of Health & Welfare,Republic of Korea, No.0620220-1
文摘Arteriovenous fistula (AVF) involving the inferior mesenteric vessels is rare, and the affected patients usually present with abdominal pain, mass, or features of established portal hypertension. Colonic ischemia is a less common and more serious manifestation of AVF. We report a case of ischemic colitis secondary to inferior mesenteric AVF in a patient who underwent a previous liver transplantation, subsequently developed portal vein stenosis, and then presented with acute lower gastrointestinal bleeding. He underwent percutaneous transhepatic placement of a portal vein stent and left colectomy.
