Treatment Of Arteriovenous Malformations Research Articles

CyberKnife based fractionated stereotactic radiotherapy as an upfront treatment for cerebral arteriovenous malformation

BackgroundTo explore the therapeutic outcomes of CyberKnife based fractionated stereotactic radiotherapy (CKFRT) for patients with cerebral arteriovenous malformations (AVM). MethodsBetween January 2008 and October 2020, 45 patients underwent CKFRT for cerebral AVMs as a first treatment. The delineation of AVM targets included AVM nidus. The mean target volume was 4.07 cm3, and 9 lesions (20%) were larger than 10.0 cm3. The mean marginal dose was 24 Gy (range, 20–35 Gy). CKFRT was delivered in median 3 fractions (range, 2 ∼ 5 fractions). AVM obliteration following CKFRT was confirmed by magnetic resonance imaging or angiography. ResultsDuring a median follow-up of 47 (5–148) months, complete obliteration and partial obliteration of AVM after CKFRT were obtained in 23 (51%) and 13 (29%) patients, respectively. Median time to complete obliteration was 39 (15–63) months. The cumulative probability of complete obliteration rate at 3 years was 47%. Complete obliteration rate of AVM was associated with Radiosurgery-based AVM score, which was consisted of AVM volume, patients age, and AVM location. One (2%) patient had hemorrhage during the follow-up period. ConclusionsCKFRT is an effective primary treatment for patients with cerebral AVMs with a low hemorrhage risk.

Targeting the microenvironment in the treatment of arteriovenous malformations

Extracranial arteriovenous malformations (AVMs) are regarded as rare diseases and are prone to complications such as pain, bleeding, relentless growth, and high volume of shunted blood. Due to the high vascular pressure endothelial cells of AVMs are exposed to mechanical stress. To control symptoms and lesion growth pharmacological treatment strategies are urgently needed in addition to surgery and interventional radiology. AVM cells were isolated from three patients and exposed to cyclic mechanical stretching for 24 h. Thalidomide and bevacizumab, both VEGF inhibitors, were tested for their ability to prevent the formation of circular networks and proliferation of CD31+ endothelial AVM cells. Furthermore, the effect of thalidomide and bevacizumab on stretched endothelial AVM cells was evaluated. In response to mechanical stress, VEGF gene and protein expression increased in patient AVM endothelial cells. Thalidomide and bevacizumab reduced endothelial AVM cell proliferation. Bevacizumab inhibited circular network formation of endothelial AVM cells and lowered VEGF gene and protein expression, even though the cells were exposed to mechanical stress. With promising in vitro results, bevacizumab was used to treat three patients with unresectable AVMs or to prevent regrowth after incomplete resection. Bevacizumab controlled bleeding, pulsation, and pain over the follow up of eight months with no patient-reported side effects. Overall, mechanical stress increases VEGF expression in the microenvironment of AVM cells. The monoclonal VEGF antibody bevacizumab alleviates this effect, prevents circular network formation and proliferation of AVM endothelial cells in vitro. The clinical application of bevacizumab in AVM treatment demonstrates effective symptom control with no side effects.Graphical abstractMechanical stress increases VEGF expression in endothelial AVM cells, possibly causing the VEGF upregulation in the microenvironment of AVM cells. The resulting RAS/RAF/MEK/ERK signaling in leads to progression of fast-flow malformations. The monoclonal VEGF-A antibody bevacizumab alleviates this effect, prevents circular network formation and proliferation of AVM endothelial cells in vitro. Sporadically occurring slow-flow malformations (LMs, VMs) have mutations in TEK or PIK3CA. TEK encodes the endothelial receptor tyrosine kinase TIE2. Sporadic extracranial fast-flow malformations (AVMs) show mutations in KRAS, BRAF and MAP2K1, which encodes the dual specificity mitogen-activated protein kinase MEK1. Combined targeting of the molecular causes of the disease could be key to achieve symptom control and reduce lesion growth. Orange: gain-of-function; Blue, circled with orange: enhanced signaling.

Recurrence of pediatric cerebral arteriovenous malformation after obliteration by radiosurgery: a case report

The rupture of a cerebral arteriovenous malformation is the most common cause of cerebral hemorrhage in children, with recurrence rates reported to be higher than that in adults. Herein, we present the case of a 4-year-old child who initially demonstrated obliteration of a ruptured brain arteriovenous malformation after initial Gamma Knife radiosurgery, but subsequently experienced delayed recurrence, ultimately necessitating a second Gamma Knife radiosurgery procedure. By reviewing this case, we aim to explore considerations regarding the recurrence, treatment, and follow-up strategies for pediatric arteriovenous malformations.

"Treatment of Uterine Arteriovenous Malformation and Subsequent Successful Pregnancy: A Case Report"

"Treatment of Uterine Arteriovenous Malformation and Subsequent Successful Pregnancy: A Case Report"

Application of epinephrine mixed with local anaesthetics in injection sclerotherapy of early-stage arteriovenous malformation

PurposeTo explore the effect of epinephrine mixed with local anaesthetic injection on blood flow control in early stage arteriovenous malformation (AVM) and explore suitable cases. MethodsTwenty-five patients with early stage (Schobinger clinical stage I/II) AVM were selected between September 2019 and March 2022. Local anaesthetics containing epinephrine were injected around the nourishing artery and into lesions under the guidance of ultrasound, and the blood flow distribution grade in the lesions as well as the changes in diameter, peak systolic velocity (PSV), and resistance index (RI) of the nourishing arteries and vessels in the lesions were observed to determine the type of AVM suitable for epinephrine injection. After blood flow was controlled, sclerosant agents were injected into the lesions for sclerotherapy. ResultsAfter local injection of the epinephrine mixture, the blood flow distribution in the lesion decreased by one to three grades; the diameter and PSV also decreased, while RI increased. There were statistically significant differences before and after the injection (P < 0.05). The efficacy of the injection was 80% (20/25), especially in patients with lesion vessels, a nourishing artery lumen diameter <2 mm, and a PSV <40 cm/s in the lesion. Patients with Schobinger clinical stage I AWM showed good results. ConclusionsLocal anaesthetics containing epinephrine play a positive role in reducing the distribution and velocity of blood flow in patients with AVM lesions and may be used as an experimental method for the treatment of AVM, which is beneficial for sclerotherapy in patients with early AVM.

Algorithm for Endovascular Treatment of Patients With Spinal Arteriovenous Malformations

Objective: To compare the endovascular treatment results in patients with spinal arteriovenous malformations (AVM) based on the proposed algorithm. Materials and methods: We retrospectively analyzed the endovascular treatment results in 72 patients with various types of spinal AVMs for 2014-2021. We formed 2 main groups of patients based on the developed indications for neurophysiological monitoring and provocative tests (NFM and PT): group 1 (n = 63) was treated according to the algorithm, and group 2 (n = 9) was treated before the algorithm was implemented. Group 1 was divided into subgroup 1.1 (n = 42) including patients with no indications for NFM and PT and subgroup 1.2 (n = 21) with patients indicated for NFM and PT. Subgroup 1.2 was further divided into subsubgroup 1.2A (n = 2) with patients indicated for NFM and PT yet to be informative due to severe neurological deficit and subsubgroup 1.2B (n = 19) with patients that had indications for and successfully underwent NFM and PT. We compared patients between groups 1 and 2, subsubgroup 1.2B and group 2 to evaluate the effectiveness of the algorithm (radical nature of the treatment, functional status assessment, complications). Results: Radical nature of spinal AVM treatment in group 1 was 79 % compared with 44 % in group 2 (P = 0.043). There was a significant improvement in motor function in group 1 compared with group 2 in each follow-up period (Р ≤ 0.007). Comparison of subsubgroup 1.2B and group 2 showed no significant differences (P = .05). The treatment led to complications in 5 patients (7 % of the total number of patients with spinal AVMs): 4 patients in group 2 and 1 patient in subsubgroup 1.2B. The effectiveness of the developed criteria was indirectly confirmed by difference in complications number between subsubgroup 1.2B and group 2 (P = 0.001). Conclusions: Group 1 showed better treatment results, significant clinical improvement, high radical nature of treatment, and a low percentage of complications compared with group 2. The proposed algorithm proved effective for main tasks of endovascular treatment of spinal AVMs.

Impact of COVID-19 pandemic on treatment and outcomes of cerebral arteriovenous malformations

BackgroundThere has been a recent decrease in interventional management of cerebral arteriovenous malformations (AVMs). The objective of our study was to evaluate the changing patterns in management of AVMs in...

Letter: Microsurgery Versus Microsurgery With Preoperative Embolization for Brain Arteriovenous Malformation Treatment: A Systematic Review and Meta-Analysis.

Letter: Microsurgery Versus Microsurgery With Preoperative Embolization for Brain Arteriovenous Malformation Treatment: A Systematic Review and Meta-Analysis.

Microsurgical Treatment of Arteriovenous Malformations: A Single-Center Study Experience.

The purpose of the study was to assess the functional outcomes after microsurgical resection of arteriovenous malformations (AVMs) and to compare the results between patients eligible for A Randomized Trial of Unruptured Brain Arteriovenous Malformations in this surgical series to the results reported and the ARUBA study. We reviewed the records of 169 patients who underwent microsurgical treatment of arteriovenous malformation (AVMs) in our institution between January 2016 and December 2021. These patients' functional status was assessed using modified Rankin Scale (mRS) scores at the last follow-up and before treatment. The mRS scores at the latest follow-up were classified into good outcomes (mRS < 3) and poor outcomes (mRS ≥ 3). Clinical presentation, patients' demographics, AVM characteristics, follow-up time, and obliteration rate were analyzed. Subgroup analyses were performed on the whole cohort, comparing Spetzler-Martin Grade I and Grade II, and ARUBA-eligible AVMs. The initial hemorrhagic presentation occurred in 71 (42%) out of 169 patients. The majority of the patients presented with headaches (73%). The AVMs were completely obliterated in 166 (98.2%) patients. The series included 65 Spetzler-Martin Grade I (38.5%), 46 Grade II (27.2%), 32 Grade III (18.9%), 22 Grade IV (13%), and 4 Grade V (2.4%) AVMs. There were 98 unruptured and 79 ARUBA-eligible cases. Also, optimal functional outcome was achieved in 145 (85.8%) patients. The overall mortality rate was 5.3% (9/169). The multivariate analysis illustrated that a poor outcome was significantly associated with presurgical mRS ≥3 (p < 0.013; OR, 0.206; 95% CI 0.059-0.713), increasing age (p < 0.045; odds ratio [OR], 1.022; 95% CI 1.000-0.045), and female gender (p < 0.009; OR, 2.991; 95% CI 1.309-6.832). Our study suggests that better outcomes can be obtained using microsurgical resection in the majority of patients with AVMs. Independent predictors of poor outcomes after surgical resection of AVMs include increasing age at the time of surgery, poor presurgical functional status, and female gender. Supposing that patients are more suitable for microsurgery after presurgical examination, outcomes are normally better in that case than those achieved by multimodal interventions (such as conservative treatment or ARUBA treatment arm). Therefore, we recommend early surgical removal on all surgically accessible AVMs to prevent successive hemorrhages and the consequences of poor neurological outcomes.

Endovascular Treatment of Brain Arteriovenous Malformations in Pediatric Patients: A Single Center Experience and Review of the Literature.

Brain arteriovenous malformations (bAVMs) are abnormal vascular connections with direct arteriovenous shunts, generally symptomatic in the adult life. However, a small number of bAVMs may manifest in pediatric patients, with higher bleeding risk and mortality rates when compared to adults. The purpose of this study is to review our experience with endovascular treatment of bAVMs in pediatric patients. This is a retrospective analysis of all bAVMs in pediatric patients (0-18 years) who underwent diagnostic digital subtraction angiography (DSA) at our institution from January 2010 to June 2021. Twenty-six patients met the inclusion criteria, of which 12 underwent endovascular treatment. Treated patients had a mean age of 10.25 years and 58% were females. Complete angiographic exclusion was achieved in five (42%) patients with endovascular treatment. Five patients with residual bAVM after embolization needed adjuvant therapy with surgery (n = 3) or stereotactic radiosurgery (SRS; n = 2). Two patients are still undergoing embolization sessions. Procedure-related complications occurred in two patients (17%) and included small vessel perforation and an occipital ischemic stroke. Two patients showed bAVM recurrence on follow-up (17%) and subsequently underwent SRS (n = 1) or surgery (n = 1), both resulting in complete bAVM exclusion. All patients had a modified Rankin scale (mRS) score of 0 to 2 on follow-up. Our experience supports the effectiveness and safety of endovascular treatment of bAVM in selected pediatric patients. A multidisciplinary approach combining surgery and SRS is warranted to achieve higher complete bAVM obliteration rates. Long-term follow-up is important as these lesions may show recurrence over time, especially in the pediatric population.

In Reply: Microsurgery Versus Microsurgery With Preoperative Embolization for Brain Arteriovenous Malformation Treatment: A Systematic Review and Meta-Analysis.

In Reply: Microsurgery Versus Microsurgery With Preoperative Embolization for Brain Arteriovenous Malformation Treatment: A Systematic Review and Meta-Analysis.

Deliberately Staged Combined Endovascular Embolization and Subsequent Microsurgery Resection for the Treatment of Cerebral Arteriovenous Malformations

Complex cerebral arteriovenous malformations (AVMs) require a combined therapy of endovascular embolization and microsurgical resection to eliminate the lesion and maximize neurological protection, while a deliberate time interval might contribute to optimal clinical outcomes. The present study aimed to explore the feasibility of this paradigm. All patients who underwent deliberately planned presurgery embolization and microsurgery resection between 2015 and 2023 were reviewed, with baseline data, postoperative complications, and follow-up outcomes recorded. The modified Rankin scale (mRS) was used to evaluate clinical outcomes, with mRS 0-2 defined as good. A total of 30 patients were included in the study (15 were ruptured AVMs). The median Spetzler-Martin grade of baseline AVMs was 3 (interquartile range: 2-3). The median interval between the last embolization and microsurgery was 5days (interquartile range: 2.25-7). The complete removal rate was 100%, and the overall permanent complication rate was 16.67%. At the last follow-up, 26 patients achieved mRS 0-2, while 28 had improved or unaltered mRS. The last follow-up mRS significantly improved from baseline and discharge (P= 0.0006 and P= 0.006). The last follow-up mRS decreased by 0.65 for each additional day of time interval before the 4.4-day inflection point (β=-0.65, P= 0.02) in the AVM ruptured cohort. The deliberately staged combined procedure of embolization and microsurgery might be a safe and efficacious strategy for Spetzler-Martin grade 2-5 AVMs, 4-5 days might be an appropriate staged time interval for ruptured AVMs, although further studies are needed to substantiate these findings.

Head and Neck Arteriovenous Malformations: Clinical Manifestations and Endovascular Treatments.

Arteriovenous malformations (AVMs) are vascular malformations that present high-flow direct communication between the arteries and veins, not involving the capillary beds. They can be progressive and lead to various manifestations, including abnormal skin or mucosal findings, ischemia, hemorrhage, and high-output heart failure in severe cases. AVMs often involve the head and neck region. Head and neck AVMs can present region-specific clinical manifestations, angioarchitecture, and complications, especially in cosmetic appearance and ingestion, respiratory, and neuronal functions. Therefore, when planning endovascular treatment of head and neck AVMs, physicians should consider not only the treatment strategy but also the preservation of the cosmetic appearance and critical functions. Knowledge of the functional vascular anatomy as well as treatment techniques should facilitate a successful management. This review summarizes AVMs' clinical manifestations, imaging findings, treatment strategy, and complications.

An Update of Treatment of Pancreatic Arteriovenous Malformations.

Pancreatic arteriovenous malformation is a rare entity (0.9%). There are about 200 articles available in PubMed. This review article includes 86 published articles, with 117 cases published after 2000. The median age at diagnosis was 51, and most of the patients were male (87.0%). The symptoms included pain, bleeding, pancreatitis, ulcers in the duodenum or stomach, varix formation, jaundice, and ascites. The diagnostic modalities were angiography, contrast-enhanced CT, MRI, and/or Ultra Sound. The most common treatments were surgery and embolization. The clinical success rate of embolization reported was 57.7%. The tailored embolization based on each agio-architecture had a clinical success rate of 80%. If embolic therapy is ineffective, surgical intervention should be considered.

Study of target volume effect on efficiency index and paddick comformty index for arteriovenous malformation treatment plans by gamma knife

Study of target volume effect on efficiency index and paddick comformty index for arteriovenous malformation treatment plans by gamma knife

Nidus Compacity Determined by Semi-Automated Segmentation is aStrong Quantitative Predictor of Brain Arterio-Venous Malformation Cure.

Acompact nidus is awell-known feature of good outcome after treatment in brain arteriovenous malformations (bAVM). This item, included in the "Supplementary AVM grading system" by Lawton, is subjectively evaluated on DSA. The present study aimed to assess whether quantitative nidus compacity along with other angio-architectural bAVM features were predictive of angiographic cure or the occurrence of procedure-related complications. Retrospective analysis of 83patients prospectively collected data base between 2003 to 2018 having underwent digital subtraction 3D rotation angiography (3D-RA) for pre-therapeutic assessment of bAVM. Angio-architectural features were analyzed. Nidus compacity was measured with adedicated segmentation tool. Univariate and multivariate analyses were performed to test the association between these factors and complete obliteration or complication. Compacity was the only significant factor associated with complete obliteration in our predictive model using logistic multivariate regression; the area under the curve for compacity predicting complete obliteration was excellent (0.82; 95% CI 0.71-0.90; p < 0.0001). The threshold value maximizing the Youden index was acompacity > 23% (sensitivity 97%; specificity 52%; 95% CI 85.1-99.9; p = 0.055). No angio-architectural factor was associated with the occurrence of acomplication. Nidus high compacity quantitatively measured on 3D-RA, using adedicated segmentation tool is predictive of bAVM cure. Further investigation and prospective studies are warranted to confirm these preliminary results.

Radiation-induced change after Gamma Knife radiosurgery for cerebral arteriovenous malformations

Objective: Radiation-induced change (RIC) on magnetic resonance imaging after Gamma Knife radiosurgery (GKRS) for cerebral arteriovenous malformations (AVMs) is not rare. We reviewed patients who underwent GKRS for AVMs and analyzed the results and factors associated with RIC.Methods: We reviewed 189 patients who underwent GKRS for AVMs between October 2002 and August 2017. All patients were followed up for at least 3 years. This study included 111 males and 78 females (mean age, 39.63 years; range, 3–79 years). Nineteen patients underwent pre-GKRS embolization. Seventy-six patients had ruptured AVMs and 113 had unruptured AVMs. We analyzed obliteration and RIC occurrence rates. Several demographic and clinical factors were analyzed to determine the influence of AVM obliteration on RIC occurrence.Results: The overall obliteration rate (OR) was 72.49% (137/189) at the final follow-up. The actuarial OR was 55.5% 36 months after GKRS. The overall RIC occurrence rate was 28.04% (53/189), and the actuarial RIC occurrence rate was 26.8% 24 months after GKRS. The OR showed a statistically significant difference according to AVM rupture (p&lt;0.01) and sex (p&lt;0.01). The RIC occurrence rate was significantly associated with AVM rupture (p&lt;0.01), lesion volume (p=0.04), and treatment volume (p=0.03). Other factors showed statistically non-significant relationships.Conclusion: The overall OR after GKRS for AVMs was comparable to the results of other previous reports. RIC is a common postoperative outcome following GKRS for AVMs. In this study, the OR was higher in ruptured AVMs and male patients, whereas RIC occurred more frequently in larger and unruptured AVMs.

Combined use of percutaneous and endovascular surgery in the diagnosis and treatment of arteriovenous malformation of the kidneys. Clinical observation

This article describes the causes of vascular abnormality of the upper urinary tract, arteriovenous malformation of the kidneys, its variants, possible clinical manifestations, methods of diagnosis of this condition, as well as ways to eliminate hemorrhagic complications caused by this pathology. The main method of correction of arteriovenous malformation is superselective embolization of vessels of the malformation zone. This clinical example presents a rare case of surgery in which embolization was unacceptable due to technical difficulties associated with the complexity of vascular angioarchitectonics, with the impossibility of superselective entry into varix through the arterial channel. In this regard, endovascular surgeons and urologists had to use a combined approach – percutaneous varix puncture with the introduction of a spiral and an embolizing substance through a puncture needle under the control of selective angiography of the branches of the renal artery.

Embolo/sclerotherapy for the treatment of hand arteriovenous malformations: a single-center retrospective cohort experience.

To retrospectively report our preliminary experience of treating hand arteriovenous malformations (AVMs) with embolo/sclerotherapy. Retrospectively review the demographics, treatment detail, outcome data, and complications of 13 consecutive patients with hand AVMs from January 2018 to December 2021. We embolize the dominant outflow vein with elastic coils and then use absolute ethanol or polidocanol for intravascular sclerotherapy and bleomycin for interstitial sclerotherapy. Yakes type II presents in four lesions, type IIIa in six, and type IIIb in three. A total of 29 treatment episodes were conducted for the 13 patients (1 episode for 3 patients, 2 for 4 patients, and 3 for 6 patients; the repeated treatment rate was 76.9%). The mean stretched length of coils for 1 treatment episode was 95 cm. The mean absolute ethanol dosage was 6.8 ml (range 4-30 ml). In addition, 10 ml of 3% polidocanol foam was injected and interstitial sclerotherapy with 150,000 IU bleomycin was performed on every patient. The post-operative arterial-dominant outflow vein pressure index (AVI) increased in the 29 procedures (6.55 ± 1.68 vs. 9.38 ± 2.80, P < 0.05). The Mann-Whitney U test showed that the post-operative AVI was higher in patients without re-intervention (P < 0.05). Local swelling occurred after all the procedures. Blistering occurred in 6 of the patients in 13 (44.8%) of the 29 procedures. Superficial skin necrosis occurred in 3 of the patients in 5 (17.2%) of the 29 procedures. The swelling, blistering, and superficial skin necrosis recovered within 4 weeks. No finger amputation occurred. The follow-up time was 6 months. The 6-month assessment of clinical improvement after the last treatment episode showed that 2 patients were cured, 10 were improved, and 1 remained unchanged. With regard to angiographic evaluation, 9 showed partial response and 4 complete response. Embolo/sclerotherapy can be effective and safe for hand AVM. The AVI increased significantly after embolo/sclerotherapy, and the index may be valuable in predicting recurrence in further study.

Outcomes of Microsurgical Resection of Low-Grade Cerebral Arteriovenous Malformations: A Prospective Observational Multicenter Study from a Low-Middle-Income Country

ObjectiveTo appraise the overall outcomes of microsurgical resection of low-grade arteriovenous malformations (AVMs) in a low-middle-income country. MethodsData was collected prospectively from three different neurosurgical centres in Pakistan for this study and it lasted for two years. According to the Spetzler-Martin (S-M) grading system, patients diagnosed with cerebral AVMs were divided into three classes A, B, and C. AVMs of grade 1 and 2 were included in Class A. Class B contained grade 3 AVMs, while Class C contained grade 4 and 5 AVMs. All male and female patients in Class A were eligible for this study. Patients were evaluated postoperatively for seizures, haemorrhage, focal neurological deficits, and AVM cure rates. Morbidity, mortality, and functional recovery were used to evaluate the outcome. Functional recovery and cure rate were observed after 6 months of follow-up. ResultsThere were a total of 22 patients. Mean age was 36.41 ± 14.32 SD years. There were 12 (54.5 %) male patients and 10 (45.5 %) female patients. 13 patients (59.1 %) presented with spontaneous intracerebral haemorrhage, while 9 patients (40.9 %) presented with seizures. 14 patients (63.6 %) had S-M grade 1 and 8 patients (36.4 %) had S-M grade 2. All patients underwent microsurgical resection. We discovered 4.5 % morbidity in our study. There was no postoperative mortality. At 6 months, an excellent functional outcome of 95.5 % (according to the Glasgow outcome scale) and 100 % cure rate was observed. ConclusionMicrosurgery is a safe and effective treatment for low-grade AVMs in terms of morbidity, mortality, functional outcome and cure rates in our country.