Vertebral arterio-venous fistula presenting with intracranial hemorrhage

Vertebral arteriovenous fistulas are rare lesions consisting of an abnormal shunt between the extracranial vertebral artery and the neighboring veins. The authors present a case of post-surgical high-flow left vertebral arteriovenous fistula presenting with intracranial hemorrhage. The patient underwent endovascular balloon occlusion of the fistula: after endovascular treatment a reduction of the flow was evident but the patient presented neurological deterioration related the occurrence of intraventricular-subarachnoid hemorrhage. Intracranial hemorrhage is a potential manifestation of high-flow vertebral AVF and a possible complication of endovascular fistula balloon occlusion. Direct endovascular occlusion of the vertebral artery may be primarily considered in selected cases.     

Symptomatic high-flow arteriovenous fistula after a C-2 fracture. Case report

Spinal arteriovenous fistulas (AVFs) are relatively uncommon lesions that are often diagnosed in a delayed fashion. The authors present a cause of a symptomatic high-flow AVF that developed in a patient after traumatic injury to the upper cervical spine. The patient presented to the trauma bay after a motor vehicle collision, and was found to have a C-2 fracture involving the transverse foramen. Although the patient was neurologically intact on presentation, 6 hours after admission weakness developed on his left side. Imaging studies demonstrated complete transection of the distal cervical aspect of the right vertebral artery (VA) at the base of C-2, with antegrade and retrograde flow into a direct AVF, resulting in early filling of the right internal jugular vein and other external draining veins. The patient was treated endovascularly with coil occlusion of the VA both proximal and distal to the transection. The patient's weakness improved over the next 7 days. At the 12-week follow-up examination, the patient's fractures had healed and he was neurologically intact.     

Arteriovenous fistula after endovenous ablation for varicose veins

Endovenous ablation, using radiofrequency or laser, is becoming the mainstay of treatment for symptomatic varicose veins in the setting of saphenous vein incompetency. Both procedures have been shown to produce high rates of truncal vein occlusion with few complications. This article presents three patients who developed arteriovenous fistula (AVF) following great saphenous vein treatment: two following radiofrequency ablation (RFA) and one following laser ablation. This is the first published report of AVF following RFA for which operative details are known. We review the literature and discuss possible causes and management of this rare complication.     

Arteriovenous fistula involving the inferior petroclival vein--case report

A 68-year-old man presented with an extremely rare extracranial arteriovenous fistula (AVF) involving the inferior petroclival vein (IPCV) with retrograde venous drainage into an ophthalmic vein through the anterior condylar confluence and inferior petrosal sinus manifesting as ocular symptoms. The AVF was successfully treated by selective transvenous embolization with platinum coils. AVF involving the IPCV should be recognized as a possible extracranial lesion manifesting as clinical symptoms similar to cavernous sinus dural AVF.     

Dural arteriovenous fistula of the transverse sinus with concomitant ipsilateral meningioma

A 69-year-old female complained of headache and tinnitus. Computed tomography, magnetic resonance imaging, and angiography showed a tumour in the right transverse sinus extending to the transverse-sigmoid sinus junction, a dural arteriovenous fistula (AVF), and right transverse-sigmoid sinus thrombosis with the downstream from the right sigmoid sinus involved by the tumour. Right external carotid angiography showed the tumour to be supplied by many branches of the right occipital artery, the posterior branches of the middle meningeal artery, and the posterior auricular artery, and the dural AVF fed by the occipital artery and the meningeal branches of the right vertebral artery. She underwent surgery via a combined right supra- and infratentorial approach. The tumour had invaded and blocked the right transverse sinus, which was resected. After surgery the patient was free of headache and tinnitus was diminished. Histological examination found that the tumour was a fibrous meningioma and that the orifice of the vein at the transverse sinus was blocked by the tumour. Serial follow-up cerebral angiography 2 months after surgery showed no change in the AVF, but 9 months after surgery confirmed disappearance of the AVF. This AVF was caused by occlusion of the right transverse sinus by the meningioma and was an acquired lesion.     

Successful surgical repair of an ilio-iliac arteriovenous fistula associated with a ruptured common iliac artery aneurysm

IntroductionWe describe the case of an 86-year-old man with an ilio-iliac arteriovenous fistula (AVF) resulting from a ruptured aneurysm. This condition rarely occurs, has a high mortality rate, and was successfully treated via surgery.Presentation of caseThe patient presented with a temporary loss of consciousness and left leg edema. A pulsatile abdominal mass with vascular murmur and thrill was detected. Enhanced computed tomography showed abdominal aortic and iliac aneurysms with left common iliac vein occlusion, and the left external iliac vein was easily seen through the AVF. We directly sutured the AVF and performed aneurysmectomy and prosthetic graft replacement. During surgery, placement of occlusive balloon catheters through the AVF minimized intraoperative bleeding. The patient recovered uneventfully, and swelling of the left leg was immediately reduced after surgery.DiscussionAlthough rare, AVFs can be life-threatening, and urgent treatment and intensive care are occasionally needed. Surgical management of AVF requires a definitive preoperative diagnosis and control of venous bleeding during surgery. Fulfilling these major requirements can potentially reduce morbidity and mortality in patients with AVFs. Interestingly, there was no sign of high-output heart failure throughout the treatment course due to compression of the aneurysm and consequent blood flow failure to the left iliac vein.ConclusionUsing the balloon occlusion technique, we were able to minimize blood loss during open repair. Use of multiple imaging modalities facilitates correct preoperative diagnosis and consequently improves surgical outcome.     

Intracranial venous hypertension and the effects of venous outflow obstruction in a rat model of arteriovenous fistula

A model of rat arteriovenous fistula (AVF) was created using a proximal common carotid artery to distal external jugular vein anastomosis. Anatomical dissections revealed that the external jugular vein is the primary vessel draining intracranial venous blood. Physiological measurements were made with the AVF open and closed, and during venous outflow occlusion of the contralateral external jugular vein. Opening the AVF increased torcular pressure from 6.5 +/- 0.6 to 13.5 +/- 1.1 mm Hg and decreased mean arterial pressure from 82.7 +/- 1.8 to 62.8 +/- 1.8 mm Hg (both P less than .05), decreasing cerebral perfusion pressure from 76.2 +/- 1.7 to 49.3 +/- 2.2 mm Hg (P less than .05). Middle cerebral artery blood flow velocity (MCA BFV) decreased from 6.8 +/- 1.1 to 4.2 +/- 0.7 cm/s (P less than 0.05). In rats with an AVF, occlusion of venous outflow increased torcular pressure to 34.8 +/- 3.1 mm Hg (P less than 0.05), MCA BFV decreased to 1.8 +/- 0.5 cm/s (P less than 0.05), and severe ischemic changes were seen on the electroencephalogram. Under this condition, torcular pressure and systemic arterial pressure had a positive linear relationship (P less than 0.05), whereas in control rats torcular pressure and arterial pressure had no relationship. Restoration of cerebral perfusion pressure by release of venous outflow occlusion and AVF closure transiently increased MCA BFV to 69% above baseline (P less than 0.05). Histological examination 1 week after permanent venous outflow occlusion revealed venous infarction, subarachnoid hemorrhage, and severe brain edema in rats with an AVF but not in control rats without an AVF. This model of cerebrovascular steal with venous hypertension reproduces both hemodynamic and hemorrhagic complications of human AVF and emphasizes the importance of venous outflow obstruction and venous hypertension in the pathophysiology of these lesions.     

Progressive myelopathy caused by dural arteriovenous fistula at the craniocervical junction--case report.

A 68-year-old male presented an unusual dural arteriovenous fistula (AVF) located at the craniocervical junction. Magnetic resonance imaging revealed dilated perimedullary veins around the spinal cord at C-1 and C-2 levels, as well as high intensity signals in the spinal cord on T2-weighted images. Vertebral angiography identified an AVF at the point where the right vertebral artery penetrates the dura. The fistula was a single and direct communication between the vertebral artery and the spinal vein. Surgical interruption of the fistula at its venous side resulted in prompt improvement of both motor and sensory signs and symptoms.     

Inferior vena cava bypass: experimental evaluation of externally supported grafts and initial clinical application

Inferior vena caval obstruction is an unusual but important clinical problem for which adequate treatment previously has not been available. Recently, a polytetrafluoroethylene (PTFE) graft with external rigid spiral supports was developed that appeared particularly applicable to the venous system. In 18 dogs a 15 cm length of Impraflex was placed from the proximal right common iliac vein to the inferior vena cava (IVC) at the level of the renal veins after IVC and right iliac vein interruption. End-to-end and end-to-side iliac vein anastomoses were alternated, with and without distal femoral arteriovenous (AV) fistulas (AVFs). At 2 months, with a distal AV fistula, 11 of 12 (92%) grafts were patent, angiograms demonstrated no evidence of intraluminal clot, and there was no hind limb edema. Following AVF ligation 2 months after graft insertion, 10 grafts remained patent, but five developed some intraluminal thrombus and one of them progressed to complete occlusion. Four months after fistula ligation (6 months after graft insertion) 9 of 12 grafts (75%) remained patent. All six grafts without distal AVF were occluded within 1 week. This procedure was performed on one severely symptomatic patient who had IVC occlusion, and currently the patient shows marked improvement. Thus IVC bypass is possible when an externally supported PTFE prosthesis is complemented by a temporary AVF.     

Spontaneous spinal epidural arteriovenous fistulae in neurofibromatosis type-1

BACKGROUND: NF-1 is one of the most common autosomal-dominantly inherited genetic disorders with an incidence of approximately 1:3500. We report a case and review the literature to characterize spontaneous spinal AVF that occur in neurofibromatosis (NF-1). CASE REPORT: A 51-year-old woman presented with NF-1 and progressive radiculomyelopathy. Angiography revealed an AVF terminating in a giant intraspinal epidural varix extending paraspinally through the C3/4 neural foramen. Trapping of the AVF attempted 18 years earlier prevented endovascular access for embolization, and vigorous bleeding made direct surgical resection impossible. Therefore, as palliation, arterial feeding collaterals were occluded, and surgically exposed tortuous veins were packed with coils. Laminectomies and partial resection of the epidural varix resulted in subtotal occlusion with clinical improvement. CONCLUSION: The spinal AVF associated with NF-1 appears to show dominant venous drainage to the intraspinal extradural and paraspinal venous plexus without evidence of intradural drainage. The vertebral artery is typically the origin of the fistula. A giant venous varix and numerous collateral feeders to the vertebral artery may give an AVM-like appearance. Clinically, the fistulae produce a syndromic triad including symptoms of NF-1, progressive radiculomyelopathy, and a bruit. Treatment is direct attack on the fistula by either surgery or embolization. If, however, a direct approach cannot be chosen, occlusion of feeding vessels combined with laminectomies can result in long-term symptomatic improvement.     

Arteriovenous fistula with associated aneurysms coexisting with dural arteriovenous malformation of the anterior inferior falx. Case report and review of the literature.

This 24-year-old man presented with an unusual case of a high-flow arteriovenous fistula (AVF). This lesion was similar to giant AVFs in children that have been previously described in the literature. In patients in whom abnormalities of the vein of Galen have been excluded and in whom presentation occurs after 20 years of age, a diagnosis of congenital AVF is quite unusual. The fistula in this case originated in an enlarged callosomarginal artery and drained into the superior sagittal sinus via a saccular vascular abnormality. Two giant aneurysmal dilations of the fistula were present. In an associated finding, a small falcine dural arteriovenous malformation (AVM) was also present. Arterial supply to the AVM arose from both external carotid arteries and the left vertebral artery, with drainage through an aberrant vein in the region of the inferior sagittal sinus into the vein of Galen. Craniotomy with exposure and trapping of the AVF was performed, with subsequent radiosurgical (linear accelerator) treatment of the dural AVM. Through this combination of microsurgical trapping of the AVF and radiotherapy of the dural AVM, an excellent clinical outcome was achieved.     

Combination of intravascular surgery and surgical operation for occipital subcutaneous arteriovenous fistula in a patient with neurofibromatosis type I

We presented a case of neurofibromatosis type I (NF-1) associated with an extracranial arteriovenous fistula (AVF) fed by the occipital and vertebral artery. A 20-year-old man was referred to our hospital because of an occipital subcutaneous pulsatile mass. A CT scan showed a huge subcutaneous enhanced mass. Angiography revealed that the occipital AVF was fed by bilateral occipital arteries, the left ascending pharyngeal artery, the left middle cerebral artery, and the left vertebral artery with-abundant communication with the subcutaneous veins. Endovascular treatment by using both coil and glue (Eudragid) embolization via the occipital artery successfully obliterated the AVF. Subsequently surgical operation was performed. Postoperative angiography showed the disappearance of the AVF. Combination of intravascular surgery and surgical operation should be considered as an effective treatment for NF-1 associated with AVF.     

Treatment of "swing point stenoses" in hemodialysis arteriovenous fistulae

AIM: This is a retrospective study of percutaneous transluminal balloon angioplasty (PTA) efficacy for treatment of surgical vein mobilization site ("swing point") stenoses in hemodialysis arteriovenous fistulae (AVF) that fail to mature or are poorly functioning. METHOD: Between February 1, 1999, and February 28, 2001, 65 non-maturing or poorly functioning AVF were studied in 63 consecutive hemodialysis patients (30 male, 33 female, aged 26-92 years). All AVF underwent contrast angiography to study the inflow artery, AVF, outflow and central veins. PTA of stenotic sites was performed to initiate or restore AVF function. RESULTS: Seventy-eight venous and 2 arterial stenoses were found and treated with PTA in the 65 AVF. All PTA were technically successful. A total of 55 stenoses were identified in the vein at the site of surgical mobilization ("swing point"). Additionally, 19 cephalic and 4 central venous stenoses were found. During the study, 13 AVF underwent repeat PTA at the "swing point". Of the 65 AVF treated, 50 were being successfully used as an access site, 4 AVF were lost during follow-up (34-688 days; mean: 258 days) and 8 patients died within the study period. The duration of functional patency of the treated AVF was 39-660 days (mean: 280 days). CONCLUSION: Non-maturing or poorly functioning AVF frequently have stenoses in the outflow vein at the original site of surgical vein mobilization. These "swing point stenoses" are amenable to PTA, which is a safe and effective treatment for prolonging AVF patency and function.     

A case of dural arteriovenous fistula of the inferior petrosal sinus successfully treated by transarterial and transvenous embolizations

A 69-year-old male was admitted with chemosis and exophthalmos of his right eye. Angiograms revealed a dural arteriovenous fistula (AVF) involving the right inferior petrosal sinus. The AVF was fed by the right occipital and ascending pharyngeal arteries and drained into the cavernous sinus and right superior ophthalmic vein from the right inferior petrosal sinus. He was treated by transarterial embolization with polyvinyl alcohol in order to reduce the shunt-flow through the fistula. Then he was treated by transvenous embolization with GDC coils five days after the arterial embolization. Symptoms in his right eye have completely disappeared. Transvenous embolization combined with transarterial embolization is a useful and safe approach in the management of AVF involving the inferior petrosal sinus.     

Dural arteriovenous fistula involving the superior sagittal sinus following sinus thrombosis--case report

A 57-year-old woman presented with a dural arteriovenous fistula (AVF) involving the superior sagittal sinus (SSS) based upon serial radiological examinations. Her chief complaints were headache and vomiting. Cerebral angiography and magnetic resonance (MR) venography revealed the sinus thrombosis involving the SSS, the bilateral transverse sinuses (TSs), and the right sigmoid sinus. Her symptoms disappeared after anticoagulant therapy. Follow-up MR venography revealed almost complete recanalization of the occluded sinuses, followed by restenosis of the SSS and the left TS and occlusion of the right TS without symptoms. She developed transient right hemiparesis 13 months after the initial onset. Cerebral angiography revealed a dural AVF involving the SSS with cortical reflux into the left frontoparietal region. The dural AVF was occluded by transarterial and transvenous embolization. Her symptom disappeared during the follow-up period.     

球囊扩张成形术处理透析用动静脉内瘘狭窄性病变及短中期结果

目的:探讨球囊扩张成形技术在治疗血液透析用动静脉内瘘(AVF)狭窄的临床效果。方法:回顾性分析2014年5月—2015年12月间采用球囊扩张成形技术治疗的31例血液透析用AVF狭窄性病变患者的临床资料。结果:31例患者中,男18例,女13例;桡动脉-头静脉内瘘27例,桡动脉-贵要静脉内瘘2例,尺动脉-贵要静脉内瘘2例;均接受球囊扩张技术治疗。28例(90.3%)获得技术上的成功,围手术期无患者死亡。1例患者术后出现动脉穿刺处假性动脉瘤,1例患者术后出现AVF血栓形成,1例患者出现前臂皮下血肿,其他所有患者AVF恢复通畅并能够以正常流量进行血液透析治疗。术后随访3~12个月,3、6、12个月初次通畅率分别为92.9%,75.0%,50.0%。结论:球囊扩张成形术处理AVF狭窄性病变微创、安全,是AVF狭窄性病变的合理治疗方法,但其中长期疗效仍有待于进一步改善。     

Questionable value of adjuvant arteriovenous fistula in pedal bypass at high risk for early failure

Results of an adjuvant arteriovenous fistula (AVF) in pedal bypass surgery in the presence of poor status of the recipient artery, severely impaired intraoperative runoff, or revision for early failure and flow restitution were analyzed in a retrospective study. From January 1998 to December 2006, 24 adjuvant AVFs were constructed in autologous vein or composite pedal bypasses with low intraoperative bypass flow, poor status of the pedal artery, or during successful early bypass revision to prevent graft failure. All infrainguinal bypass operations were registered in a computerized database and prospectively followed. Pedal bypasses with adjunctive AVF were reviewed for fistula function, graft patency, limb salvage, and patient survival. Primary and secondary bypass patency rates at 1 year were 59% and 77%, respectively, with an AVF patency of 36%. Four legs were amputated despite a patent bypass with patent AVF on three occasions. The corresponding limb salvage rate was 65% at 1 year. Patient survival was 50% at 3 years. Adjuvant AVF constructed in grafts considered at high risk for early failure in pedal vein graft or composite bypass does not seem to prevent future graft failure. In patent bypasses the fistula has a significant tendency for spontaneous occlusion. It may be considered in the use of prosthetic composite pedal grafts in selected cases.     

Vertebral arteriovenous fistula that developed in the same place as a previous ruptured aneurysm: a case report

BACKGROUND: Aneurysms of the extracranial vertebral artery (VA) and vertebral arteriovenous fistulas (VAVFs) are relatively rare diseases. The most frequent cause of both diseases is trauma. Atraumatic lesions are less common. Presented here is a case of atraumatic AVF of the extracranial VA that developed in the same location as a previous ruptured aneurysm of the ipsilateral VA that was originally treated by proximal occlusion 11 years earlier. METHODS: A 40-year-old woman presented with a massive hematoma in the upper posterior neck region caused by the rupture of an extracranial VA aneurysm. Proximal occlusion of the VA was performed by use of a detachable balloon. She enjoyed good health for 11 years, then she noticed a pulsatile bruit. Angiograms revealed an AVF between the left VA that was fed by collateral circulation and the paravertebral venous plexus. Incidentally found were soft tissue masses in the left retroauricular and the right suboccipital regions. Also, skull X-ray films showed multiple bony defects. Biopsy of the subcutaneous mass was performed in the hope of obtaining clues as to which pathological processes had weakened the artery. RESULTS: As direct transarterial access to the fistula was out of the question, the fistulous compartment of the paravertebral venous plexus was tightly packed with multiple platinum coils effected by the transfemoral approach. A histological examination of the specimen revealed features of a neurofibroma, and a diagnosis of neurofibromatosis Type 1 was established. CONCLUSIONS: In this case, transvenous embolization of the VAVF was successfully performed. The fragility of the arterial wall, related to neurofibromatosis Type 1, was considered to contribute to the development of the aneurysm and AVF.     

Evaluation of clinical examination preceding surgical treatment of AV-fistula problems. Is angiography necessary?

Clinical and angiographic findings at preoperative assessment were compared in a prospective investigation of 34 consecutive uraemic patients with problems of vascular access. The series comprised 26 patients with malfunctioning arteriovenous fistulas (AVF) and 8 who were about to receive a new AVF. The diagnostic sensitivity and specificity of clinical examination in malfunctioning AVF were, respectively, 50 and 100% in cases with significant stenosis upstream from the cannulation site (inflow restriction). The corresponding figures in cases with significant stenosis or vein occlusion downstream from the cannulation site (outflow restriction) were 38 and 43%. Clinical disclosure of outflow restriction is considerably impeded when there is concurrent inflow restriction. The advantages and disadvantages of the most commonly used angiographic techniques are discussed.     

A proposed management algorithm for fistulae between hemodialysis access circuits and adjacent veins

Purpose: Fistulae between an arteriovenous hemodialysis graft (AVG) or fistula (AVF) and an adjacent vein are an unusual complication of hemodialysis access. Such fistulae may theoretically cause steal syndrome, extremity edema, or access dysfunction. We sought to use our experience and existing literature to develop a management algorithm for this access complication. Methods: Twelve patients with AVG/AVF to adjacent vein fistulae found on fistulography were identified using a quality assurance database. Indications for fistulography, treatment rendered for both the fistulae and access stenosis, and outcome of treatment were determined. AVG/AVF to adjacent vein fistulae, when identified and considered to be significant, were treated with embolization. Results: Five out of twelve patients had successful embolization of their AVG/AVF to adjacent vein fistulae. Reasons for treatment included partial thrombosis of the access to the level of the fistula (n=1), contribution to bleeding during dialysis (n=1), and concern for competing flow causing thrombosis (n=5). No recurrence was identified. Seven patients did not undergo embolization either because of failure to recognize the fistula (n=3) or determination that treatment was not indicated (n=4). Two untreated fistulae were found occluded at follow-up. Additional access treatment included angioplasty (n=11), covered stent (n=1), and mechanical thrombectomy (n=3). Conclusions: The significance of AVG/AVF to adjacent vein fistulae remains unclear; some resolve spontaneously, possibly related to PTA of outflow stenosis. Embolotherapy is an effective treatment for such fistulae when determined to be significant.