Adjunctive venous sinus stenting in transvenous embolization of vein of Galen malformations.

BACKGROUND: Vein of Galen malformations are congenital arteriovenous malformations primarily treated by endovascular embolization via transarterial or transvenous approaches. transvenous embolization can be utilized to close the malformation but may be difficult in patients with venous stenosis or blockages, which drive venous hypertension and lead to significant neurologic consequences. Here, we illustrate the atypical placement of an intracranial venous sinus stent to improve outflow after transvenous embolization in pediatric patients with the vein of Galen malformation. METHODS: A retrospective review of clinical databases at two high-volume endovascular centers from January 2018 to March 2023 identified all vein of Galen malformation patients who received a venous sinus stent during transvenous embolization. Clinical data, imaging, angioarchitecture, operative details, postoperative management, and follow-up were reviewed. RESULTS: Three patients presented for transvenous embolization after multiple staged transarterial embolizations of their vein of Galen malformation. Transvenous access was complicated by lateral sinus stenosis, which was temporarily relieved by balloon angioplasty. After transvenous embolization by pressure cooker technique, the dural sinuses were stented using the existing venous guide catheter. Venous angiography demonstrated improved flow across the stenosed areas and post-embolization angiography demonstrated normalized venous drainage with widely patent stents. One patient experienced postoperative oculomotor nerve palsy unrelated to the stent placement. All patients demonstrated a complete cure of their vein of Galen malformations with patent venous sinus stents on follow-up. CONCLUSION: In patients with the vein of Galen malformation and venous hypertension receiving transvenous embolization, venous sinus stenting may be a safe and effective option to reduce aberrant cortical venous drainage and improve normal outflow. Further studies are warranted to investigate its benefit in high-flow vascular malformations.

Use of a mini balloon microcatheter to facilitate penetration of fine vascular networks and curative embolization in vein of Galen malformations.

Background Patients with vein of Galen malformations (VOGMs) can develop fine angiogenic networks with fistulous connections to the precursor of the vein of Galen. In these cases, transarterial embolization (TAE) with liquid embolic agents (LEAs) is challenging due to reflux in the pedicle leading to the network, causing poor penetration. Transvenous approaches carry a risk of hemorrhage from pathologic vasculature. Dual-lumen balloon microcatheters like the Scepter Mini (Microvention, Aliso Viejo, CA) improve distal pedicle access, preventing reflux.Objective Here, we report on the use of the Scepter Mini for TAE of angiogenic VOGM.Methods A single-institution retrospective chart review identified all VOGMs treated with Scepter Mini microcatheters. Clinical data, angioarchitecture, and technical parameters were reviewed.Results 17 Scepter Mini catheters were used in 12 embolization procedures of 7 patients with VOGM at a median age of 2.1 years. Patients presented with hydrocephalus (100%) and gross motor and speech delays (57.1%). Networks developed extra-axially into the subependymal zone fed by posterior choroidal, posterior cerebral, and thalamoperforator arteries. Posterior choroidal branches (n=7/17, 41.2%) were most frequently catheterized to achieve distal access to the network. Embolization with Onyx-18 and significant network penetration occurred in 17/17 uses. Near tip entrapment with LEA cast displacement occurred in 1/17 uses. Another patient experienced postprocedural intraventricular hemorrhage requiring a third ventriculostomy without permanent neurologic deficit.Conclusion The Scepter Mini provided excellent distal access with penetration to the fistula and extra-axial network reduction with few complications. The Scepter Mini provides a means for successful treatment of technically challenging angiogenic VOGM.

Evolution of transvenous embolization in vein of Galen malformation: case series and review of the literature.

BACKGROUND: Treatment of vein of Galen malformations (VOGMs) has improved greatly since the inception of endovascular treatment. Transvenous embolization (TVE) is an attractive option to achieve complete obliteration. OBJECTIVE: To review the literature on TVE of VOGM and then analyze our practice's unique experience and evolving treatment strategies over 30 years. METHODS: A retrospective review of our clinical database for patients with the diagnosis of VOGM treated between January 2004 and August 2021 was performed. A literature review of 49 relevant articles was also carried out. RESULTS: TVE in VOGM has evolved with initial introduction as a transtorcular (TT) approach, which then lost favor to transarterial embolization (TAE). TAE has been considered the more favorable approach in most high-volume centers. In more recent times, the transvenous embolization (TVE) approach has been revisited as a last treatment to achieve a cure after a series of TAE treatments. We presently favor beginning treatment with staged TAE to reduce flow to the lesion and, importantly, shrink the draining vein. This then allows for the performance of TVE with the Chapot pressure cooker technique (CPCT) with coils and liquid embolic embolization. CONCLUSIONS: TT TVE itself carries a high degree of risk and is most highly associated with long-term morbidities and mortality. Traditional transfemoral/transjugular TVE approaches are safe and effective in simple fistulas with a small venous pouch; however, we believe that the CPCT is the safest technique as a last-stage treatment for its security in avoiding reflux and obtaining occlusion of the small perforators.

Percutaneous sclerotherapy of microcystic lymphatic malformations: the use of an innovative gravity-dependent technique.

BACKGROUND: In the last few decades there has been development of innovative therapies for the treatment of craniofacial lymphatic malformations. Percutaneous sclerotherapy has demonstrated efficacy in the management of macrocystic lymphatic lesions, but it is less suitable for microcystic lesions given their size. The gravity-dependent technique is a novel augmentation of standard percutaneous sclerotherapy: the technique enables a sclerosing agent to permeate the small microchannels seen in microcystic lesions that would otherwise be difficult to treat. METHODS: Between 2005 and 2021, 124 patients with microcystic or mixed lymphatic malformations were treated using a novel gravity-dependent sclerotherapy technique. Bleomycin at a maximum dose of 15 IU per session was used as the main sclerosing agent. Fluoroscopy and ultrasound were used to ensure proper positioning of the catheter prior to injecting the sclerosing agent. The response to treatment was assessed clinically and with cross-sectional imaging. RESULTS: Nearly all cases showed significant improvement after the gravity-dependent technique. There have been no permanent complications from sclerotherapy treatment. There was a mild transient adverse effect from bleomycin in one case of erythema and tenderness that lasted several weeks then ameliorated. CONCLUSIONS: The gravity-dependent sclerotherapy technique is a suitable treatment option for microcystic lymphatic malformations.

Transvenous embolization of vein of galen aneurysmal malformations using the "Chapot pressure cooker" technique.

METHODS: Two patients, one 5-year-old and one 7-year-old, both presented with congestive heart failure in the newborn period and were subsequently treated in the newborn period with multiple, staged TAEs with n-BCA for choroidal VGAMs. RESULTS: We achieved progressive reduction in shunting and flow but were unable to accomplish complete closure of the malformation: in both patients, a small residual with numerous perforators persisted. The decision was made to perform TVE using the CHPC. In this technique, a guiding catheter is placed transjugular into the straight sinus (SS). One or two detachable tip microcatheters are advanced to the origin of the SS. Another microcatheter is advanced and the tip placed between the distal marker and the detachment zone of the former. Coils and n-BCA are used to prevent reflux of Onyx. CONCLUSIONS: In this study, we recognized two important factors of traditional VGAM treatment that may cause interventionalists to consider the ChPC to treat VGAM: (1) without liquid embolic, deployed coils may not occlude the fistula entirely. (2) There is the concern of causing delayed bleeding should the arterial component of the fistula rupture. ChPC ameliorates these issues by offering complete closure of the fistula with liquid embolic material in TVE.

Bleomycin sclerotherapy for eyelid venous malformations as an alternative to surgery or laser therapy.

PURPOSE: To evaluate the clinical outcome of patients with venous malformation (VM) involving the eyelid treated with bleomycin sclerotherapy. METHODS: A retrospective review was performed of 18 consecutive patients with VM involving the eyelid who underwent bleomycin sclerotherapy. Patients' clinical presentation, details of sclerotherapy, and post-sclerotherapy resolution of the lesion as well as any procedure-related complications were evaluated. RESULTS: Twelve women and six men of mean age 34.3±20.4 years underwent sclerotherapy with bleomycin. Chief complaints were cosmetic disfigurations with or without hemifacial deformity (n=2), pain in engorgement area (n=2), pain and swelling from venous thrombosis (n=2), swelling or engorgement obstructing their eyesight (n=2), or eyelid dysfunction (n=1). The lesions were only in the eyelid in three patients; otherwise they were extended out of the eyelid either superiorly (n=3), laterally (n=8), inferiorly (n=8), and/or posteriorly to the orbit (n=8) to various extents. Conjunctival involvement was present in 13 patients. 14 patients had received prior treatments including surgery, laser therapy, or non-bleomycin sclerotherapy. With an average three sessions of bleomycin sclerotherapy (average total dose 34.5 mg), more than 80% shrinkage was observed in seven patients (38.9%), 50-80% shrinkage in eight patients (44.4%), and 30-50% shrinkage in two patients (11.1%). One patient had recurrence, which was successfully treated again with bleomycin. No procedure-related complications were noted. CONCLUSIONS: The use of bleomycin appears to be a simple, safe, and effective treatment for venous malformations involving the eyelid, avoiding more elaborate and challenging surgical or laser interventions, and is even effective in full thickness lesions.

Vein of Galen Aneurysmal Malformation: Advances in Management and Endovascular treatment.

BACKGROUND: Vein of Galen aneurysmal malformation (VGAM) is a rare congenital vascular malformation representing <1% of all arteriovenous malformations. The knowledge and strategies in the management are constantly evolving. OBJECTIVE: To review our series of postneonatal VGAM patients treated over 11-yr period. METHODS: Retrospective analysis of 113 VGAM treated between January 2004 and April 2015. After exclusions, 45 patients were included: 33 choroidal and 12 mural types. RESULTS: Presenting symptom in the order of frequency: enlarged head circumference, antenatal diagnosis, mild CHF, and PHT at birth. Older patients were diagnosed following trauma, headache, cognitive decline, and incidentally during workup for other diseases. Hydrocephalus due to hydrodynamic disorder was present in 70% of choroidal and 58% of mural types. Only a quarter needed cerebrospinal fluid diversion procedure. Radiological cure was achieved in 82%; the outcome graded on a 5-point scale: 0 (death) to 4 (normal). A total of 66.6% are neurologically and developmentally intact with outcome score 4, 20% had outcome score of 3, and 8.9% had outcome score of 2. There was 4.4% mortality. Dural feeders to VGAM were found either in the initial or during the treatment in 22.2% in the current series. Angiogenesis from pial vessels developed after partial embolization in 17.7% that resolved completely following complete obliteration of VGAM. CONCLUSION: Technical and technological advancements in endovascular embolization along with better understanding of clinical, anatomic, and pathophysiological aspects have resulted in significantly improved outcome and prognosis in VGAM. Most patients with proper treatment can now survive and most develop normally following appropriately timed treatment.

Mutations in Chromatin Modifier and Ephrin Signaling Genes in Vein of Galen Malformation.

Normal vascular development includes the formation and specification of arteries, veins, and intervening capillaries. Vein of Galen malformations (VOGMs) are among the most common and severe neonatal brain arterio-venous malformations, shunting arterial blood into the brain's deep venous system through aberrant direct connections. Exome sequencing of 55 VOGM probands, including 52 parent-offspring trios, revealed enrichment of rare damaging de novo mutations in chromatin modifier genes that play essential roles in brain and vascular development. Other VOGM probands harbored rare inherited damaging mutations in Ephrin signaling genes, including a genome-wide significant mutation burden in EPHB4. Inherited mutations showed incomplete penetrance and variable expressivity, with mutation carriers often exhibiting cutaneous vascular abnormalities, suggesting a two-hit mechanism. The identified mutations collectively account for ∼30% of studied VOGM cases. These findings provide insight into disease biology and may have clinical implications for risk assessment.

Expanding the clinical and molecular findings in RASA1 capillary malformation-arteriovenous malformation.

RASA1-related disorders are vascular malformation syndromes characterized by hereditary capillary malformations (CM) with or without arteriovenous malformations (AVM), arteriovenous fistulas (AVF), or Parkes Weber syndrome. The number of cases reported is relatively small; and while the main clinical features are CMs and AVMs/AVFs, the broader phenotypic spectrum caused by variants in the RASA1 gene is still being defined. Here, we report the clinical and molecular findings in 69 unrelated cases with a RASA1 variant identified at ARUP Laboratories. Sanger sequencing and multiplex ligation-dependent probe amplification were primarily used to evaluate RASA1. Several atypical cases were evaluated using next-generation sequencing (NGS) and array-comparative genomic hybridization (aCGH). Sixty individuals had a deleterious RASA1 variant of which 29 were novel. Nine individuals had a variant of uncertain significance. Five large RASA1 deletions were detected, giving an overall deletion/duplication rate of 8.3% (5/60) among positive cases. Most (75.4%) individuals with a RASA1 variant had CMs, and 44.9% had an AVM/AVF. Clinical findings in several cases expand the RASA1 phenotype. Our data suggest that screening for large RASA1 deletions and duplications in this disorder is important and suggest that NGS multi-gene panel testing is beneficial for the molecular diagnosis of cases with complex vascular phenotypes.

Vein of Galen malformations in neonates: new management paradigms for improving outcomes.

BACKGROUND: Untreated patients with symptomatic neonatal presentation of vein of Galen aneurismal malformations (VGAMs) carry almost 100% morbidity and mortality. Medical management and endovascular techniques for neonatal treatment have significantly evolved. OBJECTIVE: To evaluate the clinical and angiographic outcomes of modern management of neonates with refractory heart failure from VGAMs. METHODS: From 2005 to 2010, 16 neonatal patients with VGAM presented to our institution. Medical care from the prenatal to perinatal stages was undertaken according to specified institutional guidelines. Nine patients with refractory heart failure required neonatal endovascular intervention. All patients were treated by transarterial deposition of n-butyl cyanoacrylate into fistula sites. Short- and long-term angiographic studies and clinical outcomes were reviewed. RESULTS: Control of heart failure was achieved in 8 patients. One premature baby died shortly after treatment. Long-term angiographic follow-up shows total or near-total angiographic obliteration in all 8 patients. One patient has a mild hemiparesis from treatment. Another has a mild developmental delay. One patient developed a severe seizure disorder and developmental delay. Overall, 66.7% patients have normal neurological development with near-total or total obliteration of the malformation. CONCLUSION: Treatment of refractory heart failure in neonatal VGAM with modern prenatal, neurointensive, neuroanesthetic, and pediatric neuroendovascular care results in significantly improved outcomes with presumed cure and normal neurological development in most.