利用者:加藤勝憲/ガレン大静脈瘤
| Vein of Galen aneurysmal malformations | |
|---|---|
| 別称 | Vein of Galen aneurysmal dilations |
 | |
| Axial image from computerized tomography angiogram showing arteriovenous communication in vein of Galen malformation | |
| 概要 | |
| 分類および外部参照情報 | |
ガレン大静脈瘤（英: Vein of Galen aneurysmal malformations、VGAMs および 英: Vein of Galen aneurysmal dilations、VGADs）は乳幼児や胎児に最も頻度の高い動静脈奇形である[1][2]。VGAMは、拡大した動脈によって供給される拡張した血管のもつれた塊から成る[3]。この奇形は加齢とともに増大するが、増大の機序は不明である[3]。大大脳静脈の拡張は、動静脈瘻を介して動脈から直接、または動脈から直接血液を受ける支脈を介して、動脈血の力が加わることによる二次的な結果である[1][3]。 通常、流出静脈の下流に静脈の異常があり、大大脳静脈への高血流とともにその拡張を引き起こす[4]。右心室と肺動脈も軽度から重度の拡張を起こす[5]。
Signs and symptoms
[編集]
奇形は、新生児においてしばしば心不全、頭蓋内出血（パターン1）、水頭症、くも膜下出血を引き起こす[4]。心不全は、動静脈シャントの大きさによるもので、心拍出量の80％以上を奪う可能性があり、高圧下の大量の血液が右心や肺循環、洞静脈洞心房中隔欠損症に戻る[4][5] 。また、このような患者における最も一般的な死因である[6]。
Associated conditions
[編集]非発達性症候群も直接または間接的に大脳静脈に影響を及ぼすが、極めてまれである。これには、上大静脈症候群（superior vena cava syndrome、SVCS）、外側洞、上矢状洞、内頸静脈、またはガレンの大脳静脈自体の血栓症が含まれる[要出典]。
Genetics
[編集]10% of vein of Galen aneurysmal malformations are associated with deleterious heterozygous mutations of EPHB4[7]
Another study found that 30% of cases were associated with mutations in EPH receptor B4 (EPHB4) gene.
Diagnosis
[編集]Testing for a malformed vein of Galen is indicated when a patient has heart failure which has no obvious cause.[8] Diagnosis is generally achieved by signs such as cranial bruits and symptoms such as expanded facial veins.[4] The vein of Galen can be visualized using ultrasound or Doppler.[4] A malformed Great Cerebral Vein will be noticeably enlarged. Ultrasound is a particularly useful tool for vein of Galen malformations because so many cases occur in infancy and ultrasound can make diagnoses prenatally. Many cases are diagnosed only during autopsy as congestive heart failure occurs very early.[9]
Classification
[編集]Five patterns of Galenic arteriovenous malformations have been described:
| Pattern 1 | Many vessels, including anterior cerebral arteries, thalamic perforating arteries, and superior cerebellar arteries discharge into the vein of Galen.[9] |
|---|---|
| Pattern 2 | A single posterior choroidal artery drains into the vein of Galen.[9] |
| Pattern 3 | One or both posterior choroidal and one or both anterior cerebral arteries drain directly into the Galenic system.[9] |
| Pattern 4 | An angiomatous network of posterior choroidal and thalamic perforating arteries enter the Vein of Galen directly.[9] |
| Pattern 5 | A high flow arteriovenous malformation in the right inferior frontal lobe drains via the inferior sagittal sinus and pericallosal vein into the Vein of Galen.[10] |
These malformations develop in utero by the persistence of fistulae between primitive pia arachnoidal arteries and pial veins that cross each other at right angles.[10] Because the primitive Galenic system and the primitive choroidal system lie close together, an arteriovenous malformation involving the primitive choroidal system will inevitably involve the Galenic vein.[11] Larger arteriovenous shunts correlate with greater hemodynamic effects and earlier symptom onset; small arteriovenous shunts correlate with greater local mass effect causing progressive neurological impairment.[10]
Treatment
[編集]Treatment depends on the anatomy of the malformation as determined by angiography or Magnetic Resonance Imaging (MRI).[10]
Surgical
[編集]Head circumference measurements should be obtained regularly and monitored carefully to detect hydrocephalus. Neurosurgical procedures to relieve hydrocephalus are important. A ventriculoperitoneal shunt may be required in some infants. A pediatric cardiologist should be consulted to manage high-output failure, if present. Often patients need to be intubated. In most cases, the fistulous arteries feeding into the Vein of Galen must be blocked, thereby reducing the blood flow into the vein.[9] Open surgery has a high morbidity and mortality. Recent advances over the past few decades have made endovascular embolization the preferred method of treatment. These treatments are preferred because they offer little threat to the surrounding brain tissue. However, there have been several reported cases of arteriovenous malformations recurring.[12] The young age of many patients, the complex vascular anatomy, and the sensitive location of the Vein of Galen offer considerable challenges to surgeons.[13] Another treatment option is Radiotherapy. Radiotherapy, also called radiosurgery, involves the use of focused beams to damage the blood vessel.[12] Radiotherapy is often not pursued as a treatment because the effects of the procedure can take months or years and there is risk of damaging adjacent brain tissue.[12]
Medical care
[編集]Surgery is not always an option when the anatomy of the malformation creates too much of a risk. Recent improvements in endovascular procedures have made many cases, which were not surgically accessible, treatable.[12] Endovascular treatments involve delivering drugs, balloons, or coils to the site of the malformation through blood vessels via catheters.[12] These treatments work by limiting blood flow through the vein. There is, however, still risk of complications from endovascular treatments. The wall of the vein can be damaged during the procedure and, in some cases, the emboli can become dislodged and travel through the vascular system.[14] Two-dimensional echocardiography with color-flow imaging and pulsed Doppler ultrasound was used to evaluate one fetus and five neonates with a Vein of Galen malformation.[15] Color-flow imaging and pulsed Doppler ultrasonography provided anatomical and pathophysiological information regarding cardiac hemodynamics and intracranial blood flow; with the patient's clinical status, these methods provided a reliable, noninvasive means to evaluate the effectiveness of therapy and the need for further treatment in neonates with Vein of Galen malformations.[15] When none of these procedures are viable, shunting can be used to ameliorate the pressure inside the varix.[10] Seizures usually are managed with antiepileptic medications.[16]
Prognosis
[編集]The complications that are usually associated with vein of Galen malformations are usually intracranial hemorrhages.[17] Over half the patients with VGAM have a malformation that cannot be corrected. Patients frequently die in the neonatal period or in early infancy.[14]
Society and culture
[編集]Vein of Galen malformations are devastating complications. Studies have shown that 77% of untreated cases result in mortality.[13] Even after surgical treatment, the mortality rate remains as high as 39.4%.[13] Most cases occur during infancy when the mortality rates are at their highest. Vein of Galen malformations are a relatively unknown condition, attributed to the rareness of the malformations. Therefore, when a child is diagnosed with a faulty Great Cerebral Vein of Galen, most parents know little to nothing about what they are dealing with.[要出典]
脚注・参考文献
[編集]- ^ a b O'Brien M; Schechter M (September 1970). “Arteriovenous malformations involving the Galenic system”. The American Journal of Roentgenology, Radium Therapy, and Nuclear Medicine 110 (1): 50–55. doi:10.2214/ajr.110.1.50. ISSN 0002-9580. PMID 5459527 October 25, 2009閲覧。.[リンク切れ]
- ^ K.M. Auyeung, S. Laughlin, K.G. TerBrugge (October 2004). “Prenatal Diagnosis of Unusual Fetal Pial Arteriovenous Malformation”. Interv Neuroradiol 9 (2): 163–8. doi:10.1177/159101990300900205. PMC 3547507. PMID 20591266.
- ^ a b c Takashima S; Becker LE (May 1980). “Neuropathology of cerebral arteriovenous malformations in children”. Journal of Neurology, Neurosurgery, and Psychiatry 43 (5): 380–385. doi:10.1136/jnnp.43.5.380. ISSN 0022-3050. PMC 490562. PMID 7420086.
- ^ a b c d e Nicholson AA; Hourihan MD; Hayward C (December 1989). “Arteriovenous malformations involving the vein of Galen”. Archives of Disease in Childhood 64 (12): 1653–1655. doi:10.1136/adc.64.12.1653. ISSN 0003-9888. PMC 1792909. PMID 2696431.
- ^ a b McElhinney DB; Halbach VV; Silverman NH; Dowd CF; Hanley FL (June 1998). “Congenital cardiac anomalies with vein of Galen malformations in infants”. Archives of Disease in Childhood. Fetal and neonatal edition 78 (6): 548–551. doi:10.1136/adc.78.6.548. ISSN 1359-2998. PMC 1717608. PMID 9713012.
- ^ Johnston IH; Whittle IR; Besser M; Morgan MK (May 1987). “Vein of Galen malformation: diagnosis and management”. Neurosurgery 20 (5): 747–758. doi:10.1227/00006123-198705000-00013. ISSN 0148-396X. PMID 3601022.
- ^ Vivanti, Alexandre; Ozanne, Augustin; Grondin, Cynthia; Saliou, Guillaume; Quevarec, Loic; Maurey, Helène; Aubourg, Patrick; Benachi, Alexandra et al. (April 2018). “Loss of function mutations in EPHB4 are responsible for vein of Galen aneurysmal malformation”. Brain 141 (4): 979–988. doi:10.1093/brain/awy020. PMID 29444212.
- ^ “Vein of Galen Abnormalities”. Duke University. December 6, 2009閲覧。 [リンク切れ]
- ^ a b c d e f Hoffman HJ; Chuang S; Hendrick EB; Humphreys RP (September 1982). “Aneurysms of the vein of Galen. Experience at The Hospital for Sick Children, Toronto”. Journal of Neurosurgery 57 (3): 316–322. doi:10.3171/jns.1982.57.3.0316. ISSN 0022-3085. PMID 7097326.
- ^ a b c d e Nicholson AA; Hourihan MD; Hayward C (December 1989). “Arteriovenous malformations involving the vein of Galen”. Archives of Disease in Childhood 64 (12): 1653–1655. doi:10.1136/adc.64.12.1653. ISSN 0003-9888. PMC 1792909. PMID 2696431.
- ^ Padget DH (May 1956). “The cranial venous system in man in reference to development, adult configuration, and relation to the arteries”. The American Journal of Anatomy 98 (3): 307–355. doi:10.1002/aja.1000980302. ISSN 0002-9106. PMID 13362118.
- ^ a b c d e The Arteriovenous Malformation Study Group (June 10, 1999). “Arteriovenous Malformations of the Brain in Adults”. New England Journal of Medicine 340 (23): 1812–1818. doi:10.1056/NEJM199906103402307. ISSN 0028-4793. PMID 10362826.
- ^ a b c Alexander, Michael J.; Spetzler, Robert F. (October 2005). Pediatric Neurovascular Disease: Surgical, Endovascular, and Medical Management. New York: Thieme Medical Publishers. ISBN 978-1-58890-368-6
- ^ a b McElhinney DB; Halbach VV; Silverman NH; Dowd CF; Hanley FL (June 1998). “Congenital cardiac anomalies with vein of Galen malformations in infants”. Archives of Disease in Childhood 78 (6): 548–551. doi:10.1136/adc.78.6.548. ISSN 1359-2998. PMC 1717608. PMID 9713012.
- ^ a b Ciricillo, S.F.; SCHMIDT K.G.; SILVERMAN N.H.; HIESHIMA G.B.; HIGASHIDA R.T.; HALBACH V.V.; EDWARDS M.S.B (1990). “Serial Ultrasonographic Evaluation of Neonatal Vein of Galen Malformations to Assess the Efficacy of Interventional Neuroradiological Procedures”. Neurosurgery 27 (4): 544–548. doi:10.1227/00006123-199010000-00007. ISSN 0148-396X. PMID 2234356.
- ^ Chatterjee (May 22, 2009). “Antiepileptic drugs”. Molecules of the Millennium. Indian Journal of Pharmacology. December 6, 2009閲覧。〔ママ〕
- ^ Meyers PM; Halbach VV; Phatouros CP; Dowd CF; Malek AM; Lempert TE; Lefler JE; Higashida RT (June 2000). “Hemorrhagic complications in vein of Galen malformations”. Annals of Neurology 47 (6): 748–755. doi:10.1002/1531-8249(200006)47:6<748::AID-ANA7>3.0.CO;2-7. PMID 10852540.
外部リンク
[編集]Template:Congenital vascular defects
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