Neurosurg Focus 27 (5):E13, 2009

Endovascular embolization with Onyx in the management of sinus pericranii: a case report

Le o n a r d o Ra n g e l -Ca s t i ll a , M.D.,1 Ch a n d a n Kr i s h n a , M.D.,1 Ri c h a r d Kl u c z n i k , M.D.,2 a n d Or l a n d o Di a z , M.D.2 1Department of Neurosurgery and 2Endovascular Interventional Neuroradiology, Department of Radiology, The Methodist Hospital, Houston, Texas

Sinus pericranii (SP) is an uncommon and usually asymptomatic communication between intra- and extracranial venous drainage pathways in which blood flow can circulate bidirectionally through abnormal dilated veins through a defect. Diagnosis and evaluation of the venous drainage pattern is important if treatment is contemplated. Cerebral angiography with the use of Dyna CT can be helpful in the diagnosis of SP and its relationship with the skull defect. The authors report what is, to the best of their knowledge, the first case of SP treated by means of endovascular embolization with Onyx. (DOI: 10.3171/2009.8.FOCUS09170)

Ke y Wo r d s • sinus pericranii • endovascular therapy • Dyna CT • embolization • Onyx

i n u s pericranii was initially described by Stromeyer in size with the Valsalva maneuver. Findings on physical in 1850 as a “blood bag on the skull…in connec- examination, including a full neurological examination, tion with the veins of the diploë and through these were otherwise unremarkable. Swith the sinuses of the brain.”20 Sinus pericranii is an ab- Contrast-enhanced MR imaging revealed multiple normal vascular communication of extracranial venous enlarged subgaleal vessels that enhanced homogeneously blood vessels with the intracranial dural venous sinuses and showed flow void. The lesion extended from the left via a transosseous diploic vein or emissary vein. The fronto-orbital region posteriorly to the temporal , communication can be a complex network of thin-walled extending along the temporalis muscle on both medial veins that forms a varix on the external table of the skull. and lateral surfaces (Fig. 1). This abnormal varix is continuous with pericranial and Cerebral angiography showed normal arterial and subgaleal veins.6,9,15,21 capillary phases. The delayed venous phase demonstrat- In the majority of cases, the SP becomes apparent ed abnormal communication of the most anterior aspect and symptomatic as a nontender, nonpulsatile soft-tissue of the SSS via a midline frontal foramen (Fig. 2C) mass, most commonly located on the frontal region close involving only the inner table of the frontal bone. This to the midline connected to the SSS though a skull de- foramen contained a diploic vein (Fig. 2A and B) that fect.4 Off-midline lesions are extremely rare. We present connected the SSS with a large tangled venous structure a case of this rare condition that was successfully treated that extended over the malar eminence and into the soft with endovascular embolization with the use of Onyx. tissues of the infratemporal fossa. To our knowledge, embolization with the use of Onyx as Three-dimensional imaging with the use of DynaCT a definitive treatment of SP has not been previously re- better delineates the intraosseous channel along the fron- ported. tal bone and the connection from the anterior aspect of the SSS (Fig. 2D and E). The bone 3D reconstruction im- Case Report aging documents the intraosseous channel with the exter- nal foramen just posterior to the left (Fig. 2C). The History and Examination. This 27-year-old woman venous channels then extend along the orbital process of presented with a discoloration of the skin at the level of the and into the inferior the posterolateral aspect of the left orbit associated with a (Fig. 2E and F). nontender soft mass. The mass and discoloration had been Embolization and Postoperative Course. Under gen- present since early childhood, and they had extended and eral anesthesia, a percutaneous injection of the frontal increased in size over the last years. The mass increased diploic vein (Fig. 3A) demonstrated multiple irregular channels with reflux into the most anterior aspect of the Abbreviations used in this paper: SP = sinus pericranii; SSS = SSS. There was reflux into the contralateral small frontal superior sagittal sinus. diploic vein and anterograde flow into the multiple ve-

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jections demonstrated normal anterograde flow into the intracranial circulation. There was normal filling of the anterior aspect of the SSS without evidence of venous hy- pertension. There was complete disconnection from the anterior aspect of the SSS and the left frontal diploic vein. Minimal filling of the diploic vein in the right frontal re- gion was detected. General anesthesia is recommended, although it is not mandatory, because Onyx injection can be painful. The postoperative course was uneventful and the patient did not experience headaches or neurological deficits. The serpiginous extracranial veins decreased in size significantly after embolization. The patient was dis- charged home 2 days after the procedure.

Discussion Sinus pericranii has been defined as “an uncommon, usually asymptomatic condition involving abnormal com- munication between the intra- and extracranial venous drainage pathways.”3 The communication usually occurs Fig. 1. Gadolinium-enhanced MR images showing multiple enlarged via dilated emissary or diploic veins that leave the skull vessels in the left temporal and infratemporal fossa (A and B). Close-up through an aberrant skull defect that is usually lined with views (C and D) demonstrate the diploic vein (red arrows) connecting the superior sagittal sinus with the abnormal extracranial vessels. connective tissue or endothelial cells. The etiology of SP is unknown, although the condition was described as - ly as 1760 by Percival Pott.17 Some authors suggest an ac- nous vascular channels located in the soft tissues of the quired pathophysiology because of the development of SP left periorbital region. After the diagnostic arteriogram a after head trauma, skull fracture, emissary vein tear, or microcatheter (Fig. 3B) was navigated into the junction of birth trauma.4,11,13 However, the constant association with the SSS and the diploic vein, and multiple hydrocoils (Fig. other vascular anomalies7,12,14 (for example, angiomas,18 3D and E) and Onyx (Fig. 3C) were used to completely aneurysmal malformation of an internal cerebral vein,12 obliterate the connection between those structures. The subcutaneous venous cavernoma) supports a congenital postembolization right and left internal carotid artery in- cause such as failure of regression of the venous plexus

Fig. 2. Digital substraction angiogram (A and B) demonstrated the abnormal communication of the most anterior aspect of the superior sagittal sinus with the extracranial vessels via an enlarged frontal bone foramen (C). Dyna CT (D to F) delineates the intraosseous channel (red arrow) along the frontal bone and the connection from the superior sagittal sinus.

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Fig. 3. Endovascular procedure. Injection of the frontal diploic vein (A) followed by insertion of the microcatheter (B). Hydro- coils (D and E) and Onyx as an embolic agent (C) were introduced to obliterate the abnormal vein. between the periosteum and dura during early brain devel- of mixed signal intensity, with areas of flow void (Fig. 1). opment or failure of the closure of intracranial sutures.10 Invasive angiography will show the lesion in the venous The presence of endothelial lining defines a congenital phase (Fig. 2A and B), and as described above, Dyna CT SP and distinguishes it from the acquired type.7 angiography is very useful in showing the morphological Sinus pericranii affects mainly young people, 80% of characteristics of the vessels in a very detailed fashion cases occurring in patients younger than 40 years of age. and their relation to the bone structures as well as the It appears to occur with approximately equal frequency in drainage of the SP into the dural venous sinuses, usually males and female, although males may be more affected the SSS (Fig. 3A–C). Cerebral angiography and venog- due to a higher incidence of head injury.2,15 The majority raphy should be performed before any treatment plan is of SP cases occur along the midline, with 40% of the le- formulated. Digital substraction angiography is the best sions being frontal, 34% parietal, 23% occipital, and 4% diagnostic modality for excluding other vascular mal- temporal.4 The case described in the current report is a formations, including arterial and venous anomalies that rare instance of an SP located in the temporal fossa, al- can mimic SP, and it can demonstrate direct or indirect though the skull defect where the emissary vein exited drainage of a venous anomaly into the SP, both of which the skull was on the frontal region. could change the plan of treatment. Moreover, digital Patients with SP usually present with mild headache, subtraction angiography can be used to assess the venous localized tenderness, and a sensation of fullness due to dynamics and their relation to the SP. In a recent angio- the mass extension. The natural history is that of a slowly graphic classification based on flow dynamics, there were enlarging or persistent lesion. Differential diagnosis is 2 different patterns of SP: 1) dominant, in which the ve- varied and includes leptomeningeal cyst, encephalocele, nous flow uses the SP to drain the brain parenchyma and epidermoid tumor, arteriovenous malformation, and cav- bypasses the normal venous outlets; and 2) accessory, in ernous hemangioma; further evaluation is always recom- which only a portion of the brain’s venous outflow occurs mended before surgery, as the treatment for these condi- through the SP.6 tions is different. Clinical findings of SP, demonstrated Treatment for SP is very controversial and has main- by manual and dynamic maneuvers (for example, Val- ly been recommended for cosmetic reasons, for preven- salva maneuver) on physical examination, combined with tion of hemorrhage, and because of the possible risk of characteristic neurovascular imaging findings can help air embolism.1,13,19 Surgery has been the usual method of guide the correct diagnosis. A simple CT scan will show treatment. Typically, craniectomy of the involved bone a nonenhancing soft-tissue mass along with an underlying has been proposed—with division of the diploic veins and skull defect. An MR imaging study with administration cranioplasty. 4 Although surgery is curative, some studies of contrast medium will demonstrate a soft-tissue mass have reported significant hemorrhage as a result of dural

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Unauthenticated | Downloaded 10/03/21 11:46 PM UTC L. Rangel-Castilla et al. sinus lacerations.4 Other conservative approaches have P: Radiological case of the month. Sinus pericranii. Arch Pe- been proposed, since the bone channels are often small diatr Adolesc Med 148:607–608, 1994 enough to be occluded with bone wax.3 3. Brook AL, Gold MM, Farinhas JM, Goodrich JT, Bello JA: In case of an SP in which the cerebral venous pat- Endovascular transvenous embolization of sinus pericranii. Case report. J Neurosurg Pediatr 3:220–224, 2009 tern is accessory, surgical or endovascular treatment 4. Buxton N, Vloeberghs M: Sinus pericranii. Report of a case can be an option; as previously described, treatment of and review of the literature. Pediatr Neurosurg 30:96–99, a dominant SP is contraindicated because it may lead to 1999 venous congestion, venous infarction, or bleeding. In the 5. Chew J, Weill A, Guilbert F, Raymond J, Audet ME, Roy D: present case, indications for endovascular treatment were Arterial Onyx embolisation of intracranial DAVFs with corti- relief of facial pain and the desirability of a minimally cal venous drainage. Can J Neurol Sci 36:168–175, 2009 invasive intervention for cosmetic reasons. Endovascular 6. Gandolfo C, Krings T, Alvarez H, Ozanne A, Schaaf M, Bac- treatment of SP with N-butyl cyanoacrylate glue has been cin CE, et al: Sinus pericranii: diagnostic and therapeutic con- proposed.3 Since its approval by the US Food and Drug siderations in 15 patients. Neuroradiology 49:505–514, 2007 Administration, the liquid embolic agent Onyx (ethylene- 7. Kohshu K, Takahashi S: [Two cases of laterally situated sinus pericranii. (author’s transl)] Rinsho Hoshasen 26:391–394, vinyl alcohol copolymer) has been used in the endovascu- 1981 (Jpn) lar treatment of intracranial arteriovenous malformations, 8. La Barge DV III, Ng PP, Stevens EA, Friedline NK, Kestle JR, arteriovenous fistulas, and other venous malformations Schmidt RH: Extended intracranial applications for ethylene with excellent results.5,8,16 We decided to combine the use vinyl alcohol copolymer (Onyx): mycotic and dissecting aneu- of coils and Onyx to obtain a fast obliteration of the di­ rysms. J Neurosurg 111:114–118, 2009 ploic vein, minimizing the number of coils used. 9. Marras C, McEvoy AW, Grieve JP, Jager HR, Kitchen ND, The current case also illustrates the efficacy of Dyna Villani RM: Giant temporo-occipital sinus pericranii. A case CT (Fig. 3A–C) in demonstrating the morphological report. J Neurosurg Sci 45:103–109, 2001 characteristics of the SP and its relationship with osseous 10. Mori K, Yoneda S, Handa H: Posttraumatic subepicranial varix. Surg Neurol 5:337–339, 1976 structures. In addition, digital subtraction angiography 11. Nakasu Y, Nakasu S, Minouchi K, Handa J: Multiple sinus was used to demonstrate the flow pattern—in this case it pericranii with systemic angiomas: case report. Surg Neurol was an accessory flow pattern; the emissary vein origi- 39:41–45, 1993 nates from the anterior portion of the SSS and connects to 12. Nakayama T, Matsukado Y: Sinus pericranii with aneurys- the SP located in the temporal fossa. We never observed mal malformation of the internal cerebral vein. Surg Neurol dominant venous flow, so we proceeded with treatment. 3:133–137, 1975 Onyx was used as the embolic agent (Fig. 3D–E). Based 13. Nishio A, Sakaguchi M, Murata K, Nishikawa M, Nishimura on previous good results obtained with Onyx for oblitera- S: Lateral situated sinus pericranii. Case report. Surg Neurol tion of dural and cerebral AVMs, the use of this agent in 32:382–386, 1989 high–blood flow vessels is reliable and safe. Its use in low- 14. Nomura S, Kato S, Ishihara H, Yoneda H, Ideguchi M, Suzuki M: Association of intra- and extradural developmental venous flow vessels such as veins can be considered even safer. anomalies, so-called venous angioma and sinus pericranii. Childs Nerv Syst 22:428–431, 2006 Conclusions 15. Ota T, Waga S, Handa H, Nishimura S, Mitani T: Sinus peri­ cranii. J Neurosurg 42:704–712, 1975 Sinus pericranii is a rare venous anomaly that con- 16. Pierot L, Spelle L, Leclerc X, Cognard C, Bonafe A, Moret J: nects intra- and extracranial venous drainage pathways. Endovascular treatment of unruptured intracranial aneurysms: We agree with the authors of previous reports that, based comparison of safety of remodeling technique and standard on angiographic findings, the assessment of venous treatment with coils. Radiology 251:846–855, 2009 17. Sadler LR, Tarr RW, Jungreis CA, Sekhar L: Sinus pericranii: drainage patterns is crucial to determine the possibility CT and MR findings. J Comput Assist Tomogr 14:124–127, of treatment. As previously described, an endovascular 1990 approach can be a safe method for definitive treatment. 18. Sakai K, Namba K, Meguro T, Mandai S, Gohda Y, Sakurai To the best of our knowledge, this is the first report of M, et al: Sinus pericranii associated with a cerebellar venous endovascular treatment of an SP anomaly with the use of angioma—case report. Neurol Med Chir (Tokyo) 37:464– Onyx. As with surgery, the goal was to permanently oc- 467, 1997 clude the intraosseous connection of the SP to the dural 19. Spektor S, Weinberger G, Constantini S, Gomori JM, Beni- sinus, and this was successfully accomplished. Adani L: Giant lateral sinus pericranii. Case report. J Neuro- surg 88:145–147, 1998 20. Stromeyer: About sinus pericranii (translating of original Disclaimer 1850 text, Alexander E Jr, Johnson BO, trans). Surg Neurol The authors report no conflict of interest concerning the mate- 40:3–4, 1993 rials or methods used in this study or the findings specified in this 21. Vinas FC, Valenzuela S, Zuleta A: Literature review: sinus paper. pericranii. Neurol Res 16:471–474, 1994

References Manuscript submitted July 15, 2009. 1. Bollar A, Allut AG, Prieto A, Gelabert M, Becerra E: Sinus Accepted August 26, 2009. pericranii: radiological and etiopathological considerations. Address correspondence to: Leonardo Rangel-Castilla, M.D., Case report. J Neurosurg 77:469–472, 1992 Department of Neurosurgery, The Methodist Neurological Institute, 2. Bonioli E, Bellini C, Palmieri A, Fondelli MP, Tortori Donati ZC 77030, Houston, Texas. email: [email protected].

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