Prospective Study of Polytetrafluoroethylene-Covered Microplugs and Detachable Coils for Embolization of Pulmonary Arteriovenous Malformations: Technical Results, Procedure Times, and Costs.

PURPOSE: To determine time to occlusion and procedure costs of embolization of pulmonary arteriovenous malformations (PAVMs) using a polytetrafluoroethylene-covered microplug compared with embolization using detachable coils. MATERIALS AND METHODS: In this prospective study, 37 patients (mean age, 39.1 years [SD ± 17.6]) with 82 PAVMs underwent embolization with microplug or detachable coils between April 2019 and January 2023. Technical success, procedure time intervals, and costs were analyzed. RESULTS: In 37 patients, 82 PAVMs and 101 feeding arteries were successfully treated (microplug, 64; microplug + another device, 5; detachable coils alone, 32). Time from embolic device inserted into the catheter to device deployed and time to occlusion differed significantly between microplug and detachable coil cohorts (P < .0001 for both). Embolization with ≥1 microplug had a significantly shorter occlusion time than embolization with detachable coils (median, 10.0 minutes saved per feeding artery) (P < .0001). Compared with detachable coil embolization, microplug embolization saved a median of 9.0 minutes per feeding artery (P < .0001) and reduced room cost by a median of $429 per feeding artery (P < .0001). Device costs per feeding artery did not differ significantly between microplug ($2,790) and detachable coil embolization ($3,147) (P = .87). CONCLUSIONS: Compared with coils, microplugs had an equally high technical success rate but significant time to occlusion and room costs savings per feeding artery. Total room cost and device cost together did not differ significantly between microplugs and coils. Microplugs may be considered technically effective and at least cost-neutral for PAVM embolization where clinically appropriate.

Flash pulmonary oedema following arteriovenous fistula surgery: rapid assessment and treatment is key to break the vicious cycle.

An early adolescent boy with chronic kidney disease on haemodialysis was referred to the surgical clinic for the creation of an arteriovenous fistula. He was undergoing treatment for dilated cardiomyopathy and extrapulmonary tuberculosis. The patient was haemodynamically stable during the procedure, but he developed rapidly progressing dyspnoea, tachycardia and tachypnoea about 10 min after the vessels were declamped. His blood pressure rapidly rose above 220/120 mm Hg and saturation dropped below 90%. A multidisciplinary team (MDT) constituted of surgeons, nephrologists and intensivists was quickly activated. The patient was put on a mechanical ventilator and resuscitated with parenteral antihypertensives, diuretics, amiodarone and haemodialysis. The patient improved clinically and was discharged on the third postoperative day. Thus, a rapidly activated MDT approach was key in breaking the vicious cycle caused by hypertensive crisis, myocardial dysfunction and impending ventilatory failurethat occurred following access surgery.

IN.PACT AV Access Trial: Economic Evaluation of Drug-Coated Balloon Treatment for Dysfunctional Arteriovenous Fistulae Based on 12-Month Clinical Outcomes.

PURPOSE: To study, from a U.S. payer's perspective, the economic consequences of drug-coated balloon (DCB) versus standard percutaneous transluminal angioplasty (PTA) use for the treatment of stenotic lesions in dysfunctional hemodialysis arteriovenous fistulae. MATERIALS AND METHODS: Cost differences between DCBs and PTA at year 1 and beyond were calculated via 2 methods. The first approach used the mean absolute number of trial-observed access circuit reinterventions through 12 months (0.65 ± 1.05 vs 1.05 ± 1.18 events per patient for DCBs and PTA, respectively) and projected treatment outcomes to 3 years. The second approach was based on the trial-observed access circuit primary patency rates at 12 months (53.8% vs 32.4%) and calculated the cost difference on the basis of previously published Medicare cost for patients who maintained or did not maintain primary patency. Assumptions regarding DCB device prices were tested in sensitivity analyses, and the numbers needed to treat were calculated. RESULTS: Using the absolute number of access circuit reinterventions approach, the DCB strategy resulted in an estimated per-patient savings of $1,632 at 1 year and $4,263 at 3 years before considering the DCB device cost. The access circuit primary patency approach was associated with a per-patient cost savings of $2,152 at 1 year and $3,894 at 2.5 years of follow-up. At the theoretical DCB device reimbursement of $1,800, savings were $1,680 and $2,049 at 2.5 and 3 years, respectively. The one-year NNT of DCB compared to PTA was 2.48. CONCLUSIONS: Endovascular therapy for arteriovenous access stenosis with the IN.PACT AV DCB can be expected to be cost-saving if longer follow-up data confirm its clinical effectiveness.

The NASSAU (New ASSessment of cerebral Arteriovenous Malformations yet Unruptured) Analysis: Are the Results From The ARUBA Trial Also Applicable to Unruptured Arteriovenous Malformations Deemed Suitable for Gamma Knife Surgery?

BACKGROUND: The optimal management of unruptured brain arteriovenous malformations (AVMs) is controversial after the ARUBA trial. OBJECTIVE: To confirm or repudiate the ARUBA conclusion that "medical management only is superior to medical management with interventional therapy for unruptured brain arteriovenous malformations." METHODS: Data were collected from 1351 patients treated with Gamma Knife Surgery (GKS; Elekta AB, Stockholm, Sweden) for unruptured and untreated AVMs The follow-up was 8817 yr (median 5.0 and mean 6.5). The results of the analyses were compared to that found in patients randomized to medical management only in the ARUBA trial and extrapolated to a 10-yr time period. Our data were also compared to the natural course in a virtual AVM population for a 25-yr time period. RESULTS: The incidence of stroke was similar among ARUBA and our patients for the first 5 yr. Thereafter, the longer the follow-up, the relatively better outcome following treatment. Both the mortality rate and the incidence of permanent deficits in patients with small AVMs were the same as in untreated patients for the first 2 to 3 yr after GKS, after which GKS patients did better. Patients with large AVMs had a higher incidence of neurological deficits in the first 3 yr following GKS. The difference decreased thereafter, but the time until break even depended on the analysis method used and the assumed risk for hemorrhage in patent AVMs. CONCLUSION: The ARUBA trial conclusion that medical management is superior to medical management with interventional therapy for all unruptured AVMs could be repudiated.

Conventional digital subtractional vs non-invasive MR angiography in the assessment of brain arteriovenous malformation.

OBJECTIVES: Digital subtractional angiography (DSA) is the standard method for diagnosis, assessment and management of arteriovenous malformation in the brain. Conventional DSA (cDSA) is an invasive imaging modality that is often indicated before interventional treatments (embolization, open surgery, gamma knife). Here, we aimed to compare this technique with a non-invasive MR angiography (MRI DSA) for brain arteriovenous malformation (bAVM). PATIENTS AND METHODS: Fourteen patients with ruptured brain AVM underwent embolization treatment pre-operation. Imaging was performed for all patients using MRI (1.5 T). After injecting contrast Gadolinium, dynamic MRI was performed with 40 phases, each phase of a duration of 1.2 s and having 70 images. The MRI results were independently assessed by experienced radiologist blinded to the cDSA. RESULTS: The AVM nidus was depicted in all patients using cDSA and MRI DSA; there was an excellent correlation between these techniques in terms of the maximum diameter and Spetzler Martin grading. Of the fourteen patients, the drainage vein was depicted in 13 by both cDSA and MRI DSA showing excellent correlation between the techniques used. CONCLUSION: MRI DSA is a non-invasive imaging modality that can give the images in dynamic view. It can be considered as an adjunctive method with cDSA to plan the strategy treatment for bAVM.

Multicenter assessment of morbidity associated with cerebral arteriovenous malformation hemorrhages.

BACKGROUND: The optimal management strategy for unruptured cerebral arteriovenous malformations (AVMs) is controversial since the ARUBA trial (A Randomized trial of Unruptured Brain AVMs). An accurate understanding of the morbidity associated with AVM hemorrhages may help clinicians to formulate the best treatment strategy for unruptured AVMs. OBJECTIVE: To determine the morbidity associated with initial cerebral AVM rupture in patients presenting to tertiary medical centers. METHODS: Retrospective chart reviews from three tertiary academic medical centers were performed for the period between 2008 and 2014. All patients admitted with intracranial hemorrhage due to untreated AVMs were included in this study. Patient-specific variables, including demographics, imaging characteristics, neurologic examination results, and clinical outcome, were analyzed and recorded. RESULTS: 101 Patients met the inclusion criteria. Admission National Institutes of Health Stroke Scale (NIHSS) scores were 0, 1-9, and ≥10 in 26%, 29%, and 45% of patients, respectively. Hematoma locations were subarachnoid, intraventricular, intraparenchymal, and combined in 5%, 11%, 32%, and 52% of patients, respectively. Deep venous drainage was present in 43% of AVMs; AVM-associated aneurysms were present in 44% of patients. Emergent hematoma evacuations were performed in 37% of patients and 8% of patients died while in hospital. At discharge, of those who survived, NIHSS scores of ≥1 and ≥10 were found in 69% and 23%, respectively. At the 90-day follow-up, 34% had a modified Rankin Scale (mRS) score >2. Patients with admission NIHSS score ≥10 had significantly higher rates of midline shift, surgical hematoma evacuation, and follow-up mRS ≥3 (p<0.05). CONCLUSIONS: The morbidity associated with cerebral AVM rupture appeared to be higher in our study than previously reported. Morbidity from AVM rupture should be considered as an important factor, together with variables such as risk of AVM rupture and procedural risk, in determining the optimal treatment strategy for unruptured cerebral AVMs.

Validity assessment of grading scales predicting complications from embolization of cerebral arteriovenous malformations.

OBJECTIVE: Endovascular embolization, though initially approved as an adjunctive therapy for surgical excision of cerebral arteriovenous malformations (AVMs), has found extensive use in the management of these lesions. A number of systems have been proposed to stratify AVMs by the procedural risk of embolization, including the Buffalo score and AVM Neuroendovascular grade. An external validity assessment of these systems has not been performed. PATIENTS AND METHODS: A retrospective review of all patients who underwent embolization of cerebral AVMs at a single institution, between 2010 and 2016, was performed. Data including patient demographics, AVM characteristics, procedural details, complications, and outcomes were collected. RESULTS: Fifty-five embolization procedures in 39 patients (median age 53.1 years) were identified. Ten (25.6%) patients underwent more than 1 embolization procedure. A triaxial catheter system for support was used in 48 (87.3%) of the embolization procedures and a detachable tip microcatheter was used in 28 (50.9%). Complete obliteration of the AVM was achieved in 10.9% of the cases. There was one (2.6%) mortality unrelated to the procedure. Three minor (5.5%) and 2 major (3.6%) clinical complications occurred. Neither Spetzler-Martin grade, Buffalo score, or AVM Neuroendovascular grade correlated with complications. CONCLUSION: Neither Buffalo score nor AVM Neuroendovascular grade predicted complications from embolization in the present study. Given the relative infrequency of complications, the number of factors that may influence AVM treatment, recent advancements in endovascular technologies, and the subjectivity inherent in these grading systems, the relative utility of risk stratification scales in the embolization of AVMs remains largely unknown.

Incidence, management, and outcomes of the arteriovenous fistula complicating transvenous lead extraction.

BACKGROUND: An arteriovenous (AV) fistula is an infrequently reported complication of transvenous lead extraction (TLE), but may be under-recognized. OBJECTIVE: To determine the incidence, management, and outcomes of the AV fistula complicating TLE. METHODS: All TLE procedures from July 2001 to December 2012 were reviewed. RESULTS: Of 2471 patients who underwent TLE, the AV fistula occurred in 8 (0.3%; 6 pacemaker and 2 implantable cardioverter-defibrillator) procedures. Patients who developed an AV fistula had longer lead implant duration (11.8 [interquartile range 7.7] vs 5.2 [interquartile range 7.0] years) and were more likely to have required a powered sheath (8 of 8 [100%] vs 1392 of 2463 [56.5%]) compared to those who did not. Other procedural and demographic details did not discriminate. All patients had a continuous bruit along the anterior chest wall. Catheter angiography was more sensitive (100%) than computed tomography (75%) or ultrasound (25%) for confirming the diagnosis and identifying the vessels involved. One fistula closed spontaneously, while others were closed with covered stents (4) or surgical glue (1). One attempt at closure failed, and one was diagnosed postmortem. Mortality related to the AV fistula was 3 of 8 (37.5%). Patients who died all had structural heart disease. In the 5 patients with normal hearts, the AV fistula was well tolerated for up to 2 years. CONCLUSIONS: An AV fistula is an infrequent, though possibly under-recognized, complication of TLE. It requires a high index of suspicion for early diagnosis, may present late, and may be associated with significant morbidity and mortality in patients with structural heart disease.

Capillary malformation-arteriovenous malformation syndrome: a report of 2 cases, diagnostic criteria, and management.

Capillary malformation-arteriovenous malformation syndrome is a rare type of vascular malformation first described in 2003. It is an autosomal dominant inherited disorder that has been reported in association with heterozygous mutations in the RASA1 gene, which encodes the protein RASp21. The clinical picture is characterized by multiple small capillary malformations which are associated with either arteriovenous malformations or arteriovenous fistulas in both the affected individual and other members of their family. We describe 2 new familial cases of this syndrome that were clinically and genetically diagnosed and studied in our hospital.

MicroNester coils as an adjunct to endovascular embolization.

OBJECTIVES/BACKGROUND: In June 2003, detachable balloons were removed from the US market and were supplanted with coil embolization for parent artery sacrifice in difficult or nonsurgical aneurysms and other vascular pathologies. The current series examines the use of MicroNester pushable coils (Cook Medical, Bloomington, IN) as a low-cost and effective adjunct to detachable coils in the treatment of selected neurovascular pathologies. METHODS: A retrospective analysis of all patients undergoing neurointerventional procedures from November 2003 through May 2008 was performed to identify patients in whom MicroNester coils were used as part of treatment. Analysis of coil type and number as well as pathology was performed. RESULTS: MicroNesters were used in 26 cases, of which 21 were for arterial sacrifice--19 for the internal carotid artery and 2 for the vertebral artery. Fourteen were performed for intracranial aneurysms, 3 for pseudoaneurysms, 2 for carotid cavernous fistulae, 1 for a carotid blowout, and 1 for an arteriovenous malformation. Five additional procedures were transvenous, for treatment of dural arterial venous fistulae. The mean number of coils for artery sacrifice was 13, with an average of 10 MicroNesters. For transvenous embolizations, the means were 30 and 6, respectively. CONCLUSION: MicroNesters are not the coil of choice for most neurointerventional procedures because they are not retrievable. However, when parent artery sacrifice or transvenous occlusion of dural arteriovenous fistulas is the goal, MicroNesters are a relatively inexpensive and equally effective alternative to more expensive, detachable coils and can reduce the procedural costs by $3600 to $6000 for the current series.

Assessment of availability of magnetic resonance angiography (MRA) in renal arteriovenous fistula.

We report two cases of cirsoid-type renal arteriovenous fistula (RAVF) which were difficult to differentiate from renal pelvic tumor by intravenous pyelogram (IVP) and computed tomography (CT) scan. Two women visited our department complaining of sudden asymptomatic macroscopic hematuria. CT scans showed an irregular mass in the right kidney. Magnetic resonance angiography (MRA) revealed a cirsoid-type RAVF. These patients were treated with transarterial embolization (TAE) using ethanol, geratin sponge, and a coil. It is suggested that MRA is useful for the diagnosis of renal arteriovenous fistula.

Extrahepatic arterioportal fistula: three-dimensional reconstruction of computerized tomodensitometric scan for diagnosis and morphologic assessment.

Arterioportal fistulae (APFs) are rare. An asymptomatic APF was suspected by computed tomography. Multiplanar, maximum intensity projection, and surface shaded display reconstructions showed its anatomy. To our knowledge, this is the first report using such reconstructions to analyze the architecture of an extrahepatic APF. Complete assessment of APF can be achieved noninvasively, and initial endovascular treatment can be planned.

Surgical and endovascular treatment of spinal dural arteriovenous fistulas: long-term disability assessment and prognostic factors.

OBJECT: The authors assessed clinical outcomes of patients with treated spinal dural arteriovenous fistulas (DAVFs) and investigated prognostic factors. METHODS: Thirty consecutive patients with spinal DAVFs were treated at the authors' institution during the past 15 years: seven underwent surgery; seven underwent surgery after failed embolization: and 16 underwent embolization alone. The outcomes of gait and micturition disability, were analyzed. Follow up averaged 3.4 years (range 1 month-11.8 years). Age, duration of symptoms, pre- and postintervention magnetic resonance (MR) imaging findings, and preintervention disability were correlated with outcome. Seventeen patients (57%) experienced improved gait, 12 (40%) were unchanged, and one (3%) was worse. In 11 patients (37%) micturition function was improved, in 15 (50%) it was unchanged, and in four (13%) it was worse. Gait disability, as measured by the Aminoff-Logue Scale, was significantly improved after treatment, from 3.4+/-1.4 (average +/- standard deviation) to 2.7+/-1.5 (p = 0.007). Mean micturition disability scores decreased, but not significantly, from 1.9+/-1 to 1.6+/-1.1 (p = 0.20). Preintervention gait disability was not associated with improvement except for patients with Aminoff-Logue Scale Grade 4 disability (eight of nine improved; p = 0.024). For patients treated within 13 months of symptom onset, mean micturition disability decreased (p = 0.035). No association was found between clinical improvement and age, a symptom duration less than 30 months, or pre- and postintervention MR imaging-documented spinal cord edema. CONCLUSIONS: Spinal DAVF treatment significantly improved patients' mean gait disability score by almost one grade at last follow up. The mean micturition disability score was not significantly improved, unless treatment was performed within 13 months of symptom onset. Longer and more uniform follow-up study is needed to determine if improved and stabilized clinical outcomes are sustained.

Comparison of cost affecting parameters and costs of the "closed" and "open" in situ bypass technique.

OBJECTIVES: The "closed" in situ bypass results in a reduction of wound complications compared to the "open" technique. This advantage is partly diminished by extra costs for the "closed" procedure and a larger percentage of residual arteriovenous (AV)-fistulae. This aim of this study was to analyse costs related to "closed" and "open" procedures. METHODS: The cost affecting parameters: (1) duration of operation; (2) length of hospital stay; and (3) number of treated residual AV-fistulae, were analysed in a randomised group of 73 patients (35 "closed" and 38 "open") in two centres. In addition, costs of the operation, nursing care and treatment of AV-fistulae were analysed. RESULTS: The "closed" and "open" group showed a median duration of operation of 210 min (range 105-570) and 154 min (range 90-355) (p < 0.05), length of hospital stay of 16 days (range 5-51) and 25 days (range 12-65) (p < 0.01), and a percentage of patients treated for residual AV-fistulae of 40% and 5%, respectively (p < 0.01). The median "closed" operation was US$798 more expensive than the "open". Median postoperative care was US$2664 less for the "closed" group. Mean estimated costs for treatment of AV-fistulae was US$9 in the "open" and US$167 in the "closed" group. CONCLUSION: The "closed" in situ vein bypass technique is cost-effective in comparison with the "open" technique.

Transvenous hemodynamic assessment of arteriovenous malformations and fistulas. Preliminary clinical experience in Doppler guidewire monitoring of embolotherapy.

BACKGROUND AND PURPOSE: Transvenous monitoring of blood flow through intracranial vascular malformations was performed with an intravascular Doppler guidewire to assess hemodynamic changes during endovascular embolotherapy. METHODS: Flow velocity was assessed in the intracranial venous sinuses of two patients with arteriovenous malformations and seven patients with dural arteriovenous fistulas. In all cases, the Doppler guidewire was positioned in the dural sinuses coaxially through a 2.1F microcatheter. The Doppler guidewire was then advanced to the site of arteriovenous shunting for sampling of venous average peak velocity (APV) and pulsatility index. In two cases, simultaneous feeding artery flow velocity was monitored by transcranial color-coded duplex sonography. RESULTS: Before embolotherapy, the flow pattern in the venous sinuses was pulsatile, with a mean (+/-SD) APV of 39.0 +/- 22.5 cm/s. Total or near-total embolization was achieved in six of the nine cases. After embolization, the flow pattern became less pulsatile and the APV was reduced to a mean of 21.2 +/- 14.6 cm/s (P = .0123, one-tailed paired t test). The pulsatility index was used to calculate the maximum minus the minimum peak velocity (MxPV-MnPV). This was reduced from an average of 27.0 +/- 8.7 cm/s to 13.5 +/- 8.3 cm/s after treatment (P = .0456). A parallel reduction in APV of the feeding arteries was observed with embolization. CONCLUSIONS: Preliminary clinical experience indicates that transvenous assessment of two parameters, APV and MxPV-MnPV, is useful in the hemodynamic evaluation of intracranial arteriovenous shunts. This valuable hemodynamic information may be used for objective and quantitative monitoring during embolotherapy of intracranial vascular malformations.

Use of a collagen hemostatic closure device to achieve hemostasis after arterial puncture: a cost-effectiveness analysis.

PURPOSE: To evaluate whether a collagen hemostatic closure device is a safe, cost-effective alternative to manual compression for achieving hemostasis at arterial puncture sites. MATERIALS AND METHODS: A cost-effectiveness analysis, based on a meta-analysis of published data, was performed from the perspective of the health-care system. The gain in effectiveness was expressed as the decrease in rate of puncture-site complications that required treatment. Costs associated with achieving hemostasis and treating complications were included. RESULTS: Use of a collagen closure device decreased the number of puncture-site complications from 31:1,000 to 16:1,000. The average cost of using the device was $177 per patient compared with $42 per patient for manual compression. The incremental cost of averting one complication exceeded $9,000. CONCLUSION: Use of a collagen closure device to achieve hemostasis after an arterial puncture may reduce the complication rate, but the additional cost per complication averted is very high.