Adjuvant Coil Assisted Glue Embolization of Vein of Galen Aneurysmal Malformation in Pediatric Patients

Chemical abscess post vein of Galen aneurysmal malformation embolisation with ethylene vinyl alcohol copolymer

Vein of Galen aneurysmal malformation (VGAM) is a rare congenital malformation characterised by arteriovenous fistulas between primitive choroidal arteries and the median prosencephalic vein, the embryonic precursor to the vein of Galen. Endovascular techniques have changed the management of these patients with improved prognosis. An eight-month-old with VGAM managed by endovascular embolisation using ethylene vinyl alcohol copolymer (EVOH) developed a chemical abscess - a rare complication. It was managed conservatively and showed promising clinical outcome.

Contribution

Chemical abscesses following EVOH embolisation are scarce - with imaging differentials, which include brain abscess and onyx granuloma. Knowledge and successful identification of this entity are essential as its management as prognoses differ. Chemical abscess is managed conservatively and has a good prognosis.

Rapid Ventricular Pacing Facilitates Transarterial Embolization in Vein of Galen Malformations

Background: Mural type vein of Galen malformation (mVOGM) is a congenital high flow arteriovenous shunt between choroidal arteries and the prosencephalic vein of Markowski leading to heart failure and hydrovenous disorder in children. Embolizing fistulous connections can be challenging and typically requires adjunctive techniques such as induced hypotension, balloon-assisted flow control, and creation of a coil basket. These maneuvers add time, complexity, and unpredictability. Rapid ventricular pacing (RVP) has been proposed as an alternative strategy with fewer drawbacks, but has not been well studied. The approach involves catheterizing the right ventricle with a pacing catheter connected to a temporary external pacemaker. Prior to embolization, RVP is initiated to lower cardiac output. Following embolization, pacing is discontinued, and the heart returns to sinus rhythm. Methods: We performed RVP in five mVOGM patients from 4/2020 through 7/2021. Accounting for multiple procedures, RVP was utilized in ten cases and twenty-six pedicles. Results: Ventricular capture was achieved in all instances and was well tolerated, without arrhythmia. Casting the arterial pedicle with liquid embolic immediately adjacent to, or traversing, the fistulous point was achieved in 9/10 cases. There were no procedural complications. In 1 case, creation of a coil basket in the venous pouch was required to achieve a stable arterial cast Conclusions: This report describes the largest case series utilizing RVP in mVOGM. The technique appears safe and well tolerated.

Rare Neurovascular Diseases in Korea: Classification and Related Genetic Variants

Rare neurovascular diseases (RNVDs) have not been well-recognized in Korea. They involve the central nervous system and greatly affect the patients' lives. However, these diseases are difficult to diagnose and treat due to their rarity and incurability. We established a list of RNVDs by referring to the previous literature and databases worldwide to better understand the diseases and their current management status. We categorized 68 RNVDs based on their pathophysiology and clinical manifestations and estimated the prevalence of each disease in Korea. Recent advances in genetic, molecular, and developmental research have enabled further understanding of these RNVDs. Herein, we review each disease, while considering its classification based on updated pathologic mechanisms, and discuss the management status of RNVD in Korea.

Long Vascular Sheaths for Transfemoral Neuroendovascular Procedures in Children

PURPOSE

To evaluate the safety and efficacy of long vascular sheaths for transfemoral neuroendovascular procedures in children.

MATERIALS AND METHODS

A retrospective evaluation of transfemoral neuroendovascular procedures in children <18 years, using long sheaths was undertaken analyzing procedure type, fluoroscopic times, technical success, access site and systemic complications. Twenty-seven consecutive procedures were included over a 2-year period. Mean age was 8.4 years (standard deviation [SD] 6.3) (range 17.0 months-16.3 years).

RESULTS

Patients were 44% female and mean weight was 35.0 kg (SD 22.8) (range 9.8-72.2 kg). A third of the procedures were performed in ≤15 kg children. The most common procedure was for embolization (n=13, 48.1%) and the most common indication was dual microcatheter technique (52%). The most common device used was the 5 Fr Cook Shuttle sheath. Mean fluoroscopy time was 61.9 minutes (SD 43.1). Of these procedures, 93% were technically successful. Femoral vasospasm, when present, was self-limiting. Complications (3/27, 11.1%) included groin hematoma (n=1), neck vessel spasm that resolved with verapamil (n=1), and intracranial thromboembolism (n=1), with no significant difference between the ≤15 kg and >15 kg subcohorts. There were no aorto-femoro-iliac or limb-ischemic complications.

CONCLUSION

Long vascular sheaths without short femoral sheaths can be safely used for pediatric neuroendovascular procedures as they effectively increase inner diameter access without increasing the outer sheath diameter. This property increases the range of devices used and intracranial techniques that can be safely performed without arterial compromise, thus increasing the repertoire of the neurointerventionist.

Coil assisted glue embolization to improve safety and accuracy in endovascular management of Vein of Galen patients

BACKGROUND

Vein of Galen malformation (VOGM) patients present in neonatal age with cardiac failure or significant neurologic consequences. The most established method of treatment has been transarterial embolization with high concentration glue (N-Butyl Cyano Acrylate) which may be difficult to control due to very high flow rates and may migrate to the venous side with undesirable consequences. We describe our experience in four patients in whom initial coil placement in prominent feeding arteries helped inflow reduction thereby facilitating controlled glue injection with a good result and no incidence of non-target embolization.

MATERIALS AND METHODS

Four neonates who had presented during the last three years with cardiac failure were included in the study. Prominent feeders identified on imaging or DSA were treated with transarterial helical coil placement in the terminal segment just before the VOGM sac followed by controlled glue injection. The outcome was assessed by detailed clinical and imaging follow-up.

RESULTS

A total of 10 most prominent feeders were embolized in four patients. Complete embolization of the VOGM was achieved in two patients in a single session. One patient with residual small feeders showed subsequent thrombosis of these feeders, possibly secondary to flow reduction in the sac. One patient still shows thin residual feeders but good clinical improvement and is being planned for follow-up and a second session at one year of age. No complications were observed. All patients showed immediate improvement in cardiac failure and good neurological development on follow-up. On imaging, the VOGM sac regressed completely (3 patients) or significantly in size (1 patient).

CONCLUSION

Planned coil placement in the terminal part of prominent feeding arteries reduced the flow and provided lattice on which glue deposits in a controlled manner without any incidence of non-target embolization in our study. This relatively less described technique increases the safety and accuracy of the endovascular treatment in VOGM patients.

Transvenous Pressure Monitoring Guides Endovascular Treatment of Vein of Galen Malformation: A Technical Note

INTRODUCTION

Vein of Galen malformations (VGMs) are complex congenital arteriovenous malformations that generally require serial endovascular treatment sessions to slowly correct the high-flow fistulous connections that cause increased venous pressures and ultimately lead to the classic presentations of heart failure, hydrocephalus, and intracranial hemorrhages. Despite the advances in endovascular technology and embolic materials, the resolution of embolization is often limited to the subjective view of diminished flow on angiograms.

CASE REPORT

An 8-month-old patient with a VGM developed clinical signs of heart failure and growing head circumference with ventriculomegaly. The patient was treated endovascularly with a transvenous approach for coil embolization while undergoing continuous monitoring of the post-malformation venous pressures. The arterial and venous systolic blood pressures (SBP) were collected at serial time points and used to measure estimated 95% confidence interval bounds for arteriovenous SBP gradients and determine when sufficient coil embolization and flow reduction was thought to be achieved.

CONCLUSION

The transvenous pressure monitoring demonstrated progressively increasing pressure gradients between the arterial and venous systems that correlated with the degree of flow reduction on angiographic runs. The patient underwent successful coil embolization of the VGM and had improvement of heart failure and ventricular size in follow-up at 8-month post-op. This provides a novel technique to introduce an objective measurement that can guide the embolization of a VGM.