Occlusion Of Arteriovenous Fistula Research Articles

Percutaneous transcatheter occlusion of large pulmonary arteriovenous fistula with Amplatzer Septal Occluder in a young cyanotic girl

ABSTRACT For most instances, percutaneous transcatheter intervention has replaced surgical procedure as the preferred treatment for pulmonary arteriovenous fistulas (PAVFs). Despite its efficacy in interventional occlusions of small- to medium-sized PAVFs, “classic” devices such as detachable balloons and intravascular coils are not recommended for bigger fistulas due to the potential risk of embolization to the systemic circulation. This case report is a unique case of a 17-year-old cyanotic girl who had a large symptomatic solitary PAVF that was effectively closed with a 26 mm Amplatzer Septal Occlude (ASO) device. The PAVF was located in the lower right lobe of the lung. The position of the device in situ occluding the feeding channel was verified by computed tomography pulmonary angiography and postprocedure echocardiography, which also revealed the obliteration of the right-to-left shunt.

Grouting technique-combining transvenous Onyx and coils for the embolization of complex non-cavernous intracranial dural arteriovenous fistulas.

Incomplete occlusion of cerebral dural arteriovenous fistula (DAVF) may lead to fistula recurrence and rebleeding, which may necessitate several embolizations and lead to worse clinical outcomes. Herein, we describe a grouting technique for endovascular embolization and its outcomes in a series of patients with complex intracranial DAVF. A total of 20 patients with aggressive type or symptomatic intracranial non-cavernous DAVF underwent endovascular transvenous embolization combining detachable coils and Onyx. Two microcatheters were positioned either in the distal segment of the involved sinus or near the draining veins. To achieve tight occlusion of the involved sinus, coils were carefully delivered through the first microcatheter, starting from the distal segment and then to the proximal segment. Next, Onyx was injected through the second microcatheter to reinforce and fill (grout) the interspace of coil mass and gradually refluxed to the mural channels and para-sinus cortical veins until the fistula was completely occluded. Successful embolization was achieved in all 20 patients. The initial angiographic results revealed the achievement of complete occlusion in 19 patients (95%). At the postembolization follow-up, complete obliteration of the fistula was achieved in all patients (100%). No symptom or angiographic recurrence was observed at the 2- to 5-year follow-ups. No patient required additional embolization or stereotactic radiosurgery. The proposed grouting technique combining detachable coils and Onyx appears to be promising for the elimination of complex intracranial non-cavernous DAVFs.

Endovascular Fistula Salvage for Preserving Arteriovenous Fistula Failure in Haemodialysis Patient: Tertiary Referral Hospital, a Single-Centre Experience

Abstract: Efficacy of endovascular intervention for the preservation of failing accesses is very important in hemodialysis patients. This study aimed to determine the efficacy of endovascular balloon angioplasty in preserving the patency of hemodialysis arteriovenous fistula (AVF) failure. This was a retrospective study of hemodialysis patients who received endovascular intervention due to access difficulties. A single-center study was created between January 2022 and June 2022. Fistulography was conducted on patients suspected of having access stenosis, and balloon angioplasty was performed in the same setting if stenosis of 50% was confirmed. Post-operative complications and access restenosis or failure were monitored. The results obtained 69 patients with hemodialysis access failure due to AVF stenosis, occlusion, and thrombosis that were admitted or referred to our hospital. The majority of patients were 40-60 years (50.7%); 88.4% patients were male and 11.6% were female, with a mean age of 56.3±11.6 (range, 18–77). The sites of AVF failure were brachiocephalic (81.1%) and radiocephalic (18.9%). There was no complication recorded. The procedure succes rate was 81.1%. In conclusion, endovascular balloon angioplasty is effective in restoring hemodialysis access patency. Recurrence is common, and interventions must be repeated. Keeping access open can save lives. Percutaneous transluminal angioplasty (PTA) can be used to achieve safely and successfully repair arteriovenous fistulas failure. Keywords: angioplasty; arteriovenous fistula; arteriovenous graft; hemodialysis

Endovascular treatment for scalp arteriovenous fistulas: prospects and dilemmas.

Scalp arteriovenous fistula (AVF) is an anomalous arteriovenous connection without a capillary bed. For symptomatic scalp AVFs, an appropriate treatment must be chosen. Currently, endovascular treatment (EVT) can serve as an alternative to surgical excision. However, EVT of scalp AVFs constitutes a challenge. A standard EVT strategy for scalp AVFs has not yet been established. Therefore, a review of current research on EVT for scalp AVFs is essential. In this review, the following issues were discussed: scalp vessel anatomy; etiology, angioarchitecture and classification of scalp AVFs; EVT principles and techniques; and EVT complications and prognosis. In addition, we attempted to propose a feasible grading system with 4 grades. Based on the literature review and our experience, we found that scalp AVFs have a complex angioarchitecture, which made EVT only possible in specific cases with low-grade scalp AVFs. EVT can be performed by transarterial or transvenous embolization. Direct puncture embolization can also be used for scalp AVFs. Complete occlusion of scalp AVF by EVT had low complication and recurrence rates and a good prognosis.

Cost-Effectiveness of Forgoing Postoperative Catheter Angiography After Microsurgical Occlusion of Spinal Dorsal Intradural Arteriovenous Fistulas

Spinal dorsal intradural arteriovenous fistulas (DI-AVFs) represent 70% of all spinal vascular lesions. Diagnostic tools include pre- and postoperative digital subtraction angiography (DSA) and intraoperative indocyanine green videoangiography (ICG-VA). ICG-VA has a high predictive value in DI-AVF occlusion, but postoperative DSA remains a core component of postoperative protocols. The aim of this study was to evaluate the potential cost reduction of forgoing postoperative DSA after microsurgical occlusion of DI-AVFs. Cohort-based cost effectiveness study of all DI-AVFs within a prospective, single-center cerebrovascular registry from January 1, 2017, to December 31,2021. Complete data including intraoperative ICG-VA and costs were available for 11 patients. Mean (SD) age was 61.5 (14.8) years. All DI-AVFs were treated with microsurgical clip ligation of the draining vein. ICG-VA showed complete obliteration in all patients. Postoperative DSA was performed for 6 patients and confirmed complete obliteration. Mean (SD) cost contributions for DSA and ICG-VA were $11,418 ($4,861) and $12 ($2), respectively. Mean (SD) total costs were $63,543 ($15,742) and $53,369 ($27,609) for patients who did and did not undergo postoperative DSA, respectively. Comorbidity status was identified as the main driver of total cost (P= 0.01 after adjusting for postoperative DSA status). ICG-VA is a powerful diagnostic tool in demonstrating microsurgical cure of DI-AVFs, with a negative predictive value of 100%. Eliminating postoperative DSA in patients with confirmed DI-AVF obliteration on ICG-VA may yield substantial cost savings, in addition to sparing patients the risk and inconvenience of a potentially unnecessary invasive procedure.

Management of Thrombosed Dialysis Access Circuits.

Thrombotic occlusion of autologous arteriovenous fistulas or synthetic arteriovenous grafts is a serious adverse event in hemodialysis patients and declotting should be performed before next hemodialysis session, in order to avoid a central venous catheter. Various techniques exist to declot a thrombosed vascular access, including open surgical thrombectomy, catheter-directed thrombolysis and use of different types of percutaneous thrombo-aspiration catheters and mechanical thrombectomy devices. These devices can be categorized as devices with direct wall contact and hydrodynamic devices without direct wall contact. Technical and early clinical outcome results of percutaneous hemodialysis declotting are high and ranging between 70 and 100%; late clinical patency results are much lower related to restenosis or re-thrombosis; these patency results are higher for autologous arteriovenous fistulas compared to synthetic arteriovenous grafts and mainly depend on the combined efficacy of successful thrombectomy and durable treatment of the underlying stenoses, associated with the acute thrombosis.

Two cases of aseptic internal jugular vein thrombophlebitis associated with hemodialysis catheter, presenting as sore throat: case report and literature review

BackgroundNon-cuffed hemodialysis (HD) catheters are often used for emergency or temporary vascular access. Its complications include thrombosis and catheter-related bloodstream infection (CRBSI); however, thrombophlebitis can also occur. Thrombophlebitis of the internal jugular vein (IJV) may present with symptoms, such as fever, lateral neck pain, and swelling, regardless of the presence or absence of infection; however, symptoms may be minor and easily overlooked. Sore throat is a well-known symptom of Lemierre's syndrome, but has not been reported in cases of thrombophlebitis without infection. We report two cases of HD catheter-associated IJV thrombophlebitis in patients that were diagnosed with sore throat.Case presentationCase 1 included a 58-year-old woman with diabetic nephropathy on HD. She was admitted to our hospital due to the occlusion of an arteriovenous fistula (AVF) for dialysis. A temporary HD catheter was placed in the right IJV until an arteriovenous graft (AVG) was fabricated. After admission, CRBSI was suspected because she developed fever; however, bacteremia was ruled out and a sore throat gradually developed. Contrast-enhanced computed tomography (CT) revealed thrombophlebitis of the right IJV. Anticoagulation therapy was initiated and she was discharged due to an improvement of symptoms. Case 2 included an 83-year-old man with end-stage renal disease due to hypertensive nephrosclerosis. He was admitted to our hospital because of AVF occlusion. A temporary HD catheter was inserted into the right IJV and an AVG was created. He had elevated C-reactive protein levels after catheter placement but was asymptomatic. When removing the catheter, he complained of throat discomfort. Ultrasonography of the neck revealed thrombotic obstruction of the right IJV, and contrast-enhanced CT revealed thrombophlebitis of the right IJV. Blood culture results were negative. He was discharged after anticoagulation therapy was started and symptoms improved.ConclusionsThe presence of sore throat leads to the diagnosis of IJV thrombophlebitis. Pharyngeal symptoms that develop after central venous catheter (CVC) placement should be differentiated from thrombophlebitis using a minimally invasive vascular ultrasound.

Successful surgical treatment in patients with late major vascular complications of missed minor vascular injuries

Aim: Vascular injuries can result from various causes, including trauma, surgery, or medical procedures, and can present immediate life-threatening risks. While some injuries are readily apparent and require urgent intervention, others may not display obvious signs of vascular compromise during the initial evaluation, potentially leading to delayed major complications. Analyse errors in the primary treatment of vascular injuries and delayed presentation of overlooked vascular injuries as surrogate indicators of the need for improved vascular surgical training for future surgeons. Material and Methods: At the Inönü University Cardiovascular Surgery Clinic between June 2011 and June 2019, a All instances of unidentified vascular injuries that present post-trauma in the form of pseudoaneurysm, arteriovenous fistula, and post-traumatic arterial occlusion were reported within the hospitals during the study duration. Results: This study included 28 patients undergoing multiple vascular repair interventions at our institution, including 14 penetrating, 10 blunt and 4 iatrogenic. Vessels of the lower limbs were involved in 18 cases (64.2%), vessels of the upper limbs in 7 cases (25%) and vessels of the neck in 2 cases (7.14%). All patients underwent surgical procedures without any fatalities or loss of limb function. There were no fatalities or unanticipated amputations. Conclusion: Vascular injuries may lead to noteworthy delayed complications occurring months or even years subsequent to the initial injury, including false aneurysms, dissections, occlusions, and fistulas, which may cause considerable disability, albeit, fortunately, they are typically not fatal. Patients with suspected injury, even in the absence of clear clinical signs of vascular injury, should be carefully monitored and a detailed examination is recommended to assess individuals with potential vascular injury.

Off-label Use of ADO II® in the Closure of Various Congenital Heart Defects

Devices may be used for special purposes different than their production purpose. For instance, Amplatzer Ductal Occluder is actually designed for duct closure and its usage for closing defects other than ductus is named as off-label. The aim of this study is to emphasize off-label use of device: not only for PDA and VSD but also for other various defects. This study is designed retrospectively, performed by the evaluation catheterization records of patients in whom ADO II and ADO II-AS devices were used in Erciyes University Medical Faculty Children Hospital, Pediatric Cardiology Department between 2011 and 2018. Patients’ demographic criteria: age, weight at the time of procedure was gathered. The diagnosis, size of device, follow-up period and complications were also noted. From April 2011 to March 2018, a total of 121 patients underwent transcatheter closure by ADO II and 66 patients by ADO II AS. The number of PDA closure with ADO II was 48; with ADO II AS were 62. Rest of the procedures were all off-label. Types of off-label procedures performed were: VSD closure, residual mitral cleft closure, Aorta-Right atrium tunnel closure, pulmonary arteriovenous fistula occlusion, aorta-pulmonary window closure, and occlusion of the artery feeding accessory lobe in scimitar syndrome, Gerbode defect occlusion. Up to our knowledge; this study includes the largest pediatric case series with various different congenital heart defects which were closed with ADO-II. Also our ADO-II occluded VSD case series is one of the largest series in the literature with almost 6 years’ follow-up. We believe in that ADO-II device may be an alternative in percutaneous closure of various rare heart defects. It is used successfully for non-ductal defects with low complication and high compliance rates.

Hybrid interventions on cerebral dural arteriovenous fistulas with isolated segment of the venous sinus

Introduction. In most cases, dural arteriovenous fistulas of the brain can be effectively treated endovascularly. However, rare fistulas with an isolated segment of the venous sinus may be difficult to treat surgically. Hybrid surgical interventions (combination of open surgical access to the sinus and puncture embolization in hybrid operating room) can significantly increase the effectiveness of surgical treatment of patients with this pathology.The objective was to improve the results of surgical treatment of patients with cerebral dural arteriovenous fistulas with isolated segment of the venous sinus by using a hybrid surgical intervention.Methods and materials. 2 surgical interventions were performed using microsurgical and endovascular methods. Surgical interventions were made in hybrid operating room.Results. Radical occlusion of dural arteriovenous fistulas was achieved in both cases. The postoperative period was favorable in both cases with positive dynamics in the neurological status.Conclusions. Hybrid interventions combining microsurgical and endovascular methods make it possible to achieve radical occlusion of “complex” cerebral dural arteriovenous fistulas with isolated segments of the venous sinus.

Managing thrombosis of arteriovenous fistula accompanied by aneurysm and single outflow of elbow perforating vein: a case report

BackgroundWe report a case of a patient who suffered thrombosis of a radial artery-cephalic vein fistula accompanied by aneurysm and a single outflow path of the elbow perforating vein. We performed open surgery combined with Fogarty balloon catheter embolectomy, anastomotic reconstruction and forearm median vein transposition.Case presentationThe patient presented with an arteriovenous fistula (AVF) after haemodialysis 5 years ago. In the process of dialysis, the fistula vein was punctured, resulting in aneurysm, high pressure and difficult haemostasis after needle extraction. AVF occlusion was observed on April 12, 2022. We performed a combined open surgery. First, a Fogarty balloon catheter was used to remove the thrombus, and the anastomosis was then reconstructed to restore AVF fistula patency. Finally, forearm median vein transposition was used to establish dual outflow. Postoperative haemodialysis was possible. There are various methods for removing the thrombus in AVF. Here, we report a case in which we performed open surgery combined with Fogarty balloon catheter embolectomy, anastomotic reconstruction and forearm median vein transposition to ensure fistula patency.ConclusionWe removed a complete reverse ‘Z’-shaped thrombus of the elbow perforating vein in a haemodialysis fistula. This report provides an effective strategy to manage a high-pressure fistula with single outflow of the elbow perforating vein.

Comparison of Intraoperative Indocyanine Green Videoangiography vs Postoperative Catheter Angiography to Confirm Microsurgical Occlusion of Spinal Dorsal Intradural Arteriovenous Fistulas.

Dorsal intradural arteriovenous fistulas (DI-AVFs) represent 80% of spinal AVFs. Microsurgical clip occlusion is a durable treatment that uses preoperative and postoperative digital subtraction angiography (DSA) as standard practice. Intraoperative indocyanine green videoangiography (ICG-VA) is a valuable intraoperative adjunct in these cases. Intraoperative ICG-VA findings have not been compared with postoperative DSA findings. To assess the diagnostic value of intraoperative ICG-VA vs postoperative DSA for spinal DI-AVFs. A multi-institutional database of vascular malformations was queried for all surgically managed cases of DI-AVF. Patients with both intraoperative ICG-VA and postoperative DSA were included. Demographic and radiologic data, intraoperative findings, and surgical outcomes data were retrospectively analyzed. Forty-five patients with DI-AVF were identified (male sex, 32; mean age, 61.9 [range, 26-85] years). All DI-AVFs were treated with interruption of the fistula with clip occlusion of the draining vein. Intraoperative ICG-VA showed complete obliteration in all patients. Postoperative DSA was performed for 40 patients and confirmed complete obliteration in all patients. The negative predictive value of ICG-VA confirming complete occlusion of the DI-AVFs was 100%. Eighteen patients (47%) experienced clinical improvement, and 16 (42%) experienced no change in condition. ICG-VA is useful for intraoperative identification of DI-AVFs and confirmation of complete microsurgical occlusion. Correlation between intraoperative ICG-VA and postoperative DSA findings demonstrates the diagnostic power of ICG-VA. This finding suggests that postoperative DSA is unnecessary when intraoperative ICG-VA confirms complete occlusion of the DI-AVF, which will spare patients the procedural risk and cost of this invasive procedure.

Embolisation of an aneurysmal high-flow renal arteriovenous fistula in a paediatric patient: simultaneous arterial and venous approach

BackgroundA large aneurysmal renal arteriovenous fistula (AVF) can cause hypokalaemic hypertension due to activation of renin-aldosterone system due to steal effect from renal parenchyma. In comparison to nephrectomy, endovascular embolisation of renal AVF is minimally invasive and can be nephron sparing, thus preserving renal function. However, such embolisation is technically challenging and can be associated with high risk of embolic migration.Case presentationWe present a case of successful embolisation of a large aneurysmal renal AVF in a 11-year-old girl. The AVF was initially treated with coil embolization via transarterial route, resulting in partial migration of coil into inferior vena cava. After removal of the migrated coil via transvenous snaring, coils were deployed simultaneously via transarterial and transvenous routes to prevent migration. AVF flow dampened but residual flow persisted at 1 month follow up. A second embolization session with additional coil deployment and N-butyl cyanoacrylate (NBCA) injection resulted in successful occlusion of the AVF. At 3 months follow up, the girl’s blood pressure and serum potassium level have normalized without need of antihypertensive agent or potassium supplements.ConclusionEndovascular embolisation can be an effective nephron sparing treatment for large aneurysmal renal AVF. This is particularly important in paediatric patients as most renal function can be preserved with their expected longer life span. Risk of coil migration can be controlled by simultaneous transarterial and transvenous deployment. Complete occlusion of AVF can be aided by additional use of NBCA.

Feasibility and safety of guidewire-balloon entrapment technique for recanalization of thoracic central vein occlusion in hemodialysis patients.

To explore the feasibility and safety of Guidewire-Balloon Entrapment Technique (GBET) for the recanalization of thoracic central vein occlusions (TCVOs) in hemodialysis patients. A retrospective observational study was conducted using data from 28 patients who required the establishment or maintenance of hemodialysis access and were treated with GBET for the recanalization of right-sided TCVOs from January 2017 to April 2021. Of the patients, 27 required tunneled cuffed catheter (TCC) placement or exchange, and 1 had an outflow tract occlusion of the Brescia-Cimino radio cephalic arteriovenous fistula (AVF). A total of 26 patients successfully underwent TCC exchange and placement using GBET; 1 patient underwent successful recanalization of an occlusion of the outflow tract of the right Brescia-Cimino AVF; and 1 patient underwent successful TCC placement in the left internal jugular vein (LIJV) after the failure of TCC placement in the right internal jugular vein (RIJV). The success rate for GBET was 27/28 (96.43%), and there were no major complications. GBET is a safe and effective method for the recanalization of right-sided TCVOs, especially for TCC exchange and placement, and can be used as a safe and easy approach for TCVO recanalization.

Outcome after early thrombotic occlusion of arteriovenous fistulas.

Arteriovenous fistulas (AVFs) are considered the first choice for venous access in end-stage renal disease patients, however, they are also known to have a high primary failure rate (early thrombosis and maturation failure). Of these, the outcome of thrombosed immature AVFs is not well known. This study aimed to investigate the outcome of AVFs with early thrombosis. Patients who underwent AVF creation from January 2009 to December 2019 at Seoul National University Hospital or Seoul Metropolitan Government - Seoul National University Boramae Medical Center were retrospectively reviewed. Patients who received salvage operations due to early thrombosis within 30 days after access creation were analyzed. During the study period, a total of 45 patients (radiocephalic 26; brachiocephalic 19) developed early thrombosis and underwent salvage operations. The median age of patients was 61.0 (54.5-69.5) years, and 51.1% were male. The first salvage operation was performed on the median 1.0 (0.0-4.5) day after AVF creation. The most common cause for early thrombosis was venous stenosis (64.4%) and followed by poor arterial inflow (28.9%), especially in radiocephalic AVFs. About 20 AVFs were salvaged to maturation (46.5%). Post-salvage primary patency and secondary patency at 1 year was 72.6% and 100%. In a multivariate logistic regression, significant risk factors for maturation failures were minimum venous outflow diameter ⩽2.5 mm (OR, 4.433; 95% CI, 1.039-18.921; p = 0.044) and lower in patients with hypertension (OR, 0.064; 95% CI, 0.006-0.637; p = 0.019). Thrombosed immature AVFs are associated with a high failure rate after salvage operation. However, if the salvage operation is successfully performed, it is associated with an acceptable 1-year outcome.

Intraoperative Spinal Angiography during Microsurgical Occlusion of Spinal Dural Arteriovenous Fistula within the Hybrid Operation Room.

Spinal dural arteriovenous fistula (SDAVF) is a rare cause of progressive myelopathy in predominantly middle-aged men. Treatment modalities include surgical obliteration and endovascular embolization. In surgically treated cases, failure of obliteration is reported in up to 5%. The aim of this technical note is to present a safe procedure with complete SDAVF occlusion, verified by intraoperative digital subtraction angiography (DSA). We describe four patients with progressive leg weakness who underwent surgical obliteration of SDAVF with spinal intraoperative DSA in the prone position after cannulation of the popliteal artery. All surgeries took place in our hybrid operating room (OR) and were accompanied by electrophysiologic monitoring. Surgeries and cannulation of the popliteal artery were performed in the prone position. Ultrasound was used to guide the popliteal artery puncture. A 5-Fr sheath was inserted and the fistula was displayed using a 5-Fr spinal catheter. Spinal intraoperative DSA was performed prior to and after temporary clipping of the fistula point as well after the final SDAVF occlusion. The main feeder of the SDAVF fistula in the first patient arose from the right T11 segmental artery, which also supplied the artery of Adamkiewicz. The second patient initially underwent endovascular treatment and deteriorated 5 months later due to recanalization of the SDAVF via a small branch of the T12 segmental artery. The third and fourth cases were primarily scheduled for surgical occlusion. Access through the popliteal artery for spinal intraoperative DSA proved to be beneficial and safe in the hybrid OR setting, allowing the sheath to be left in place during the procedure. During exposure and after temporary and permanent occlusion of the fistulous point, intraoperative indocyanine green (ICG) video angiography was also performed. In one case, the addition of intraoperative DSA showed failure of fistula occlusion, which was not visible with ICG angiography, leading to repositioning of the clip. Complete fistula occlusion was documented in all cases. Spinal intraoperative DSA in the prone position is a feasible and safe intervention for rapid localization and confirmation of surgical SDAVF occlusion.

Clinical outcomes of procedures combining endovascular embolization with a direct surgical approach in a hybrid operating room for the treatment of refractory dural arteriovenous fistulas.

Background: We reviewed the clinical outcomes of a procedure that combines endovascular embolization and a direct surgical approach in a hybrid operating room (OR) for the treatment of refractory dural arteriovenous fistulas (dAVFs).Methods: All patients with intracranial dAVFs who underwent a procedure combining endovascular embolization and direct surgical approach with biplane angiography or a robotic C-arm system in a hybrid OR between February 2004 and June 2020 were considered. Borden grading, occlusion rate, pre-and post-operative modified Rankin Scale (mRS) scores, and complications were retrospectively investigated. The pre-and postoperative mRS scores were compared using the Wilcoxon signed-ranks test.Results: We evaluated 14 arteriovenous fistulas (AVFs) in consecutive 13 patients. Of these, ten AVFs were previously treated with endovascular embolization, ten were located in the transverse-sigmoid sinus, and four in the cortical vein. The Borden grade was II in two AVFs and III in 12 AVFs. Immediate occlusion of the AVF was achieved in 13 AVFs, and gradual occlusion was observed in one case. The median preoperative mRS was 1 (0–3), whereas the median postoperative mRS was 0 (0–1) which indicated marked improvement (P = 0.006). Complications including postoperative transient visual disturbance and intraprocedural extravasation were observed in only two cases.Conclusion: The combination of endovascular embolization and direct surgical approach in a hybrid OR could achieve sufficient occlusion of refractory AVFs with acceptable complication rates and improved symptoms.

Sharp Needle Recanalization Technique for Peripheral Hemodialysis Arteriovenous Fistula Occlusion.

To determine the efficacy of a percutaneous sharp needle recanalization technique for the treatment of peripheral hemodialysis arteriovenous fistula (AVF) occlusion. This study included 13 patients (14 procedures) between May 2010 and February 2020 with non-thrombotic AVF occlusion wherein guidewire passage through the occluded segment had failed. We successfully passed the guidewire through the occluded segment using a sharp needle recanalization technique with Chiba or Colapinto needles, under ultrasound or fluoroscopic guidance. The type of AVF, site and length of occlusion, technical success, complications, and long-term patency were analyzed. Technical success was achieved in 12 (85.7%) out of 14 procedures. The procedure failed in two patients due to the poor angle of approach in the axillary area and diffuse severe stenosis in the draining cephalic vein. In eight procedures, sharp needle recanalization was performed under ultrasound guidance, while the other six procedures were performed under fluoroscopic guidance. Chiba and Colapinto needles were used in five and nine procedures, respectively. The mean length of occlusion was 2.7cm (range 1.8-4.2cm). There was one case of mild complication, that is, mild contrast extravasation, which was treated by stent deployment. The post-intervention primary patency rates at 6months, 1year, and 2years were 81.8%, 36.4%, and 18.2%, respectively. The results of this limited series suggest that the sharp needle recanalization technique is a simple and effective method for the treatment of peripheral non-thrombotic AVF occlusion.

Embolization of Giant Post-Traumatic Arteriovenous Renal Fistula using the Penumbra Occlusion Device

Purpose: Giant post-traumatic artero-venous renal fistula is a very rare condition, and the exclusion of renal perfusion is the principal risk of embolization. Aim of our presentation is to evaluate new materials and devices derivated by neuro-angio experience to treat the vascular arterio-venous renal fistula. Material and Methods: From march 2017t to december 2020 we have treated 3 post traumatic hight-flow artero-venous renal fistulas. In one case an aneurysmatic dilatation of renal artery was associated. All patients were previously and during follow-up evaluated by MDCTA and US-color-Doppler. POD Penumbra System plus, POD packing coil were used to treat arterio-venous renal fistula. Results: In all cases (3/3) complete arterio-venous renal fistula occlusion was obtained. Pod System and Pod packing coil were delivered with microcatheter directly in the arterial side of the arterio-venous renal fistula. The renal fuction and complete parenchymal preservation were obtained Conclusions: In our preliminary experience Penumbra System revealed to be a secure device for a complete exclusion of high-flow arterio-venous renal fistula and preserving renal perfusion.

Pressure Cooker Technique for Endovascular Treatment of Spinal Arteriovenous Fistulas: Experience in 15 Cases

Spinal arteriovenous fistulas are challenging to cure by endovascular means, with a risk of incomplete occlusion or delayed recurrence. The authors report herein their preliminary experience using the pressure cooker technique for the embolization of spinal arteriovenous fistulas.Fifteen patients (8 men; mean age, 60.3 years) underwent an endovascular treatment of a spinal arteriovenous fistula (12 dural spinal arteriovenous fistulas and 3 epidural spinal arteriovenous fistulas) in 2 different institutions using the pressure cooker technique. Two microcatheters could be navigated in the segmental artery in all patients using 2 guiding catheters. A proximal plug was achieved with highly concentrated cyanoacrylate ± coils. The liquid embolic agent injected to cure the fistula was diluted cyanoacrylate (n = 11) or ethylene-vinyl alcohol (n = 4). Technical and clinical complications were systematically recorded. Clinical and angiographic outcomes were systematically evaluated at follow-up.One (6.7%) procedure-related complication was recorded, which consisted of a transient radicular deficit, related to nerve root ischemia. Clinical improvement was observed in 10/14 (71%) patients for whom clinical follow-up was available. Complete spinal arteriovenous fistula occlusion on a follow-up angiography was observed in 11/12 patients (91.7%) for whom angiographic follow-up was available. One patient (8.3%) presented with a delayed recurrence at 29 months.The pressure cooker technique is feasible, with either glue or ethylene-vinyl alcohol, for the embolization of spinal arteriovenous fistulas. Our results suggest the safety and effectiveness of this technique.