Arteriovenous fistula and nerve conduction velocity in patients on hemodialysis: statistical and electrographic findings

The aim of this study was to investigate the possible influence of arteriovenous fistula (AVF) on nerve conduction velocity in patients on intermittent hemodialysis and its relevance to the pathogenesis of carpal tunnel syndrome (CTS). The data on 22 patients showed no statistically significant differences in the electrographic parameters considered. This suggests that AVF by the end-to-end method plays no significant part in the alteration of nerve conduction. Possibly radial steal phenomena, which occur with other types of AVF, are at least partly responsible for the reported cases of CTS.

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Sommario Scopo di questo studio è stato indagare l'eventuale influenza della fistola arterovenosa (FAV) sulla velocità di conduzione nervosa in pazienti in trattamento emodialitico periodico, per le sue pssibili implicazioni nella patogenesi della sindrome del tunnel carpale (CTS). Vengono presentati i dati relativi a 22 pazienti. I risultati non hanno evidenziato differenze statisticamente significative dei parametri elettrografici considerati.Pertanto i nostri dati suggeriscono che la FAV (eseguita secondo la tecnica termino-terminale) non riveste un ruolo significativo nell'alterazione della conduzione nervosa. È possibile che fenomeni di furto nel territorio dell'arteria radiale, che si verificano con FAV eseguite con altra modalità, siano, almeno in parte, responsabili dei casi di CTS segnalati nella letteratura al riguardo.

     

Surgical treatment of high grade dural arteriovenous fistulae

Dural arteriovenous fistulae (dAVF) with direct cortical venous drainage (CVD, Borden Type III) have a high risk of hemorrhage, particularly when symptomatic. Stereotactic radiosurgery is therefore not recommended, and endovascular treatment can be limited by access, incomplete obliteration, and recanalization. Of 70 cerebral dAVF seen at our institution over the past 8 years, 35 were Borden Type III (50%). Twenty-four were treated via microsurgery (69%). Presentation included hemorrhage in nine patients (38%), nonhemorrhagic neurologic deficits in five (21%), asymptomatic in five (21%), headache in three (13%), and seizure in two patients (8%). Only eight of 19 patients with symptomatic dAVF were independent (modified Rankin Scale [mRS] 0–2) preoperatively (42%). The dAVF location was tentorial in six patients (25%), petrosal in six (25%), superior sagittal sinus in four (17%), torcular in two (7%), floor of the anterior fossa in two (7%), and sphenoid ridge, transverse-sigmoid, inferior sagittal sinus and jugular in one patient each (4%). Four patients had failed endovascular therapy (17%). The angiographic obliteration rate was 96%. The combined permanent morbidity and mortality rate was 17%. After a mean follow-up of 2.1 years, 13 patients improved (54%), seven were the same, (29%) and four were worse (17%). Thirteen patients were asymptomatic (mRS 0, 54%), and 18 were independent (mRS 0–2, 75%). Our results reinforce that surgical treatment of dAVF with direct CVD is associated with a high angiographic cure rate with acceptable morbidity and mortality, particularly in light of the lesions’ natural history.     

Pathomorphological description of the shunted portion of a filum terminale arteriovenous fistula

Background contextThe clinical morphology of a filum terminale arteriovenous fistula (f-AVF) is well known; however, pathological details of the fistulized portion are unknown. Herein, we report the pathological findings of the f-AVF.Study designCase report and literature review.PurposeTo present a detailed pathological examination of the fistulized portion of the f-AVF.MethodsA 71-year-old man presented with gradually worsening bilateral foot paresthesias and anal dysesthesia. T2-weighted magnetic resonance imaging showed flow voids surrounding an edematous conus medullaris and cauda equina with spinal stenosis at L3–L4 and L4–L5. Spinal digital subtraction angiography demonstrated an f-AVF fed by the left T9 intercostal artery.ResultsWe performed laminotomies of L3 and L4 to open the dura mater and found a hypertrophic filum terminale. It was resected, leaving a length of 2 cm between the abnormal proximal end and normal distal end. The f-AVF completely disappeared after the surgery. On pathological examination, the filum terminale included two vessels at the proximal end and one at the distal end. At the proximal end, immunostaining showed one vessel that was definitively an artery with both an internal elastic membrane (IEM) and smooth muscle. The other was a vein and lacked an IEM. On the distal side, the collagen fibers gradually increased, the IEM partially disappeared from the arterial wall, and the vein became arterialized with a thin IEM. At the distal end the two vessels joined. Therefore, we speculated that the fistulized portion of the f-AVF was not a fistula point but had some lengths where the artery had characteristics of a vein and there was venous arterialization.ConclusionsThe filum arteriovenous shunting occurred at the portion where there was venous arterialization and the artery had the characteristics of a vein. Therefore, resecting the filum terminale requires more proximal from the normal distal end.     

上海市单中心血液透析患者血管通路调查分析

目的 回顾性分析血液透析患者血管通路使用情况.方法 记录第二军医大学附属长征医院自2010年1月1日至12月31日新进入血液透析患者与长期维持性血液透析患者的基本资料和不同血管通路的选择概况,并对维持性血液透析患者中自体动静脉内瘘(arteriovenous fistula,AVF)使用和长期导管插管手术患者原发病种类进行统计分析.结果 全年血液透析患者共1102例.其中新入血液透析患者667例(60.53%),维持性血液透析患者435例(39.47%),94.94%患者每周透析3次.667 例新入透析患者分别选择临时导管81.26%、长期导管4.20%、AVF14.54%.435例维持透析患者分别选择临时导管1.84%、长期导管13.56%、AVF83.91%、人造血管0.69%.中心共施行AVF手术504例次、长期导管74例次和临时导管301例次:AVF手术中71.83%患者首选左前臂;选择右颈内静脉在长期导管和临时导管中分别为48.65%和87.04%.内瘘选择吻合血管依次为桡动脉-头静脉75.40%,肱动脉- 正中静脉16.87%,肱动脉-贵要静脉2.98%,桡动脉-贵要静脉2.38%,肱动脉-头静脉2.38%.瘘管吻合方式主要为端端吻合52.60%,端侧吻合36.44%,侧侧吻合10.96%.收治患者AVF发生并发症 173例,占总透析人数的15.7%,血栓125例占并发症总例数72.25%,其余依次为缺血14.45%,狭窄 8.67%,肿胀手4.62%.长期导管年平均感染率为0.07次/1000导管日.结论 新入透析患者中选择临时导管比例较大,说明国内患者大多数仍然不能提前准备瘘管.而维持性血液透析患者则绝大多数选择AVF,聚四氟乙烯(poly tetra fluoro ethylene,PTFE)人造血管相对偏少,留置长期导管后许多患者由于方便性不愿进一步手术.减少内瘘并发症依然是临床工作者的研究目标和方向.     

Multi-detector-row CT angiography as a preoperative evaluation for spinal arteriovenous fistulae

The role of multi-detector-row computed tomographic angiography (MDCTA) in spinal vascular malformations has not yet been determined. We present a report on a short series of spinal arteriovenous fistulae (AVF) evaluated by MDCTA. With 4-row and 16-row MDCTA, three cases of spinal dural AVF and one case of perimedullary AVF were examined. Each case was also examined by magnetic resonance (MR) imaging and spinal catheter angiography. In two patients with spinal dural AVF, including one patient with angiographically occult AVF, MDCTA successfully located the site of the AVF in a multi-planar reformation image. MDCTA failed to locate the remaining case of spinal dural AVF, probably due to the small amount of shunting blood volume at the fistula. In a patient with perimedullary AVF, MDCTA visualized the broad range of the lesion, including the anterior spinal artery as a single feeder, the fistulous point, and the single perimedullary draining vein. In conclusion, although conventional spinal angiography might be still essential, MDCTA provides useful information for the surgeon in treatment of the spinal dural AVF. Further accumulation of clinical cases is required to determine the potential of MDCTA for perimedullary AVF. MDCTA should be considered as a choice of investigation in the evaluation of spinal AVFs.     

A Case of Intractable Left Forearm Congenital Arteriovenous Fistula Ending with Amputation: Importance of New Medical Information Obtained via the Internet

Objective: 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.Patient: 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.Conclusion: 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.     

芦荟对动静脉内瘘维护的研究

目的探讨芦荟外用对动静脉内瘘(arteriovenous fistula,AVF)维护的临床疗效.方法将自身血管条件差的106例血透患者(均已建立AVF),随机分为治疗组和对照组各53例.治疗组和对照组的患者均进行内瘘侧手的常规功能锻炼,治疗组另加新鲜芦荟外用,并进行近期和远期的效果评定.结果治疗组AVF明显的改善,总有效率96.22%(51/53),远期疗效表明一年的通畅率大大的提高,与对照组有显著的差异(P＜0.005).结论芦荟对AVF的功能维护有明显的疗效.