Clinical Neurology and Neurosurgery 202 (2021) 106505 Contents lists available at ScienceDirect Clinical Neurology and Neurosurgery journal homepage: www.elsevier.com/locate/clineuro Dorsal subdural hemorrhage from ruptured thoracic radicular artery pseudoaneurysm. case report and surgical video Massimiliano Minardi *, Giovanni Giulio Vercelli, Marco Mammi, Alessandro Fiumefreddo, Diego Garbossa Neurosurgery Unit, Department of Neuroscience, Città della salute e della Scienza Torino, Via Cherasco 15, Turin, Italy A R T I C L E I N F O A B S T R A C T Keywords: Pseudoaneurysm Spinal radicular artery Spinal subdural hemorrhage Radiculomedullary artery Vascular malformation Radiculomedullary artery malformations are rare conditions: their rupture usually manifests with subarachnoid hemorrhage. To the best of our knowledge no cases of subdural bleeding have been described in the literature. We present the rare case of a 74 year old woman admitted to our Institute with sudden onset of right lower limb motor deficit and hypoesthesia, with no history of trauma: Magnetic Resonance Imaging of the dorsal spine was performed and a subdural hematoma was detected; subsequent dorsal laminectomy for hematoma evacuation was carried out. As the source of bleeding was not recognized, Digital Subtraction Angiography (DSA) was performed: a new leak of contrast agent from a dilation of a spinal radicular artery at the level of T5 was detected; XperCT imaging (an angiographic acquisition of Computed Tomography-like images) confirmed a new acute subdural bleeding. Urgent repeat surgery was considered the best option to identify and close the malformation. Postoperative DSA confirmed complete exclusion of the radicular artery malformation. This is the first report that describes, with an intraoperative video, a case of radiculomedullary artery pseudoaneurysm, responsible of an acute subdural bleeding and associated neurological deficit. 1. Introduction Spinal subdural hematomas (SSDHs) are rarer than intracranial subdural hematomas. Causes can be divided into traumatic, iatrogenic (following surgery or lumbar puncture), and spontaneous, including vascular malformations or coagulation deficits [1]. Radiculomedullary artery malformations like aneurysms or pseudo-aneurysms are very rare and tend to manifest with subarachnoid hemorrhage (SAH) at rupture [2–6]. This case report describes, to the best of our knowledge, the first case of spinal subdural hematoma due to rupture of spinal radicular artery pseudo-aneurysm. 2. Case report A 74 years old woman arrived at the emergency department of our Institute for acute onset of headache and right leg motor and sensitive deficits. Past medical history was remarkable only for hypertension and dyslipidemia; no recent history of trauma was disclosed. Head Computed Tomography (CT) detected bleeding surrounding the cervical spine and angioCT of the head showed no sign of vascular malformations (Fig.1A). A spinal MRI was then performed and a sub­ dural hematoma spanning from T3 to T6 was discovered (Fig.1B). The patient was therefore taken to the operating room and bilateral lam­ inectomy from T3 to T6 was performed. The subdural hematoma was completely evacuated, as demonstrated by post-op MR imaging (Fig.1C). After the operation, the patient did well with partial recovery of her motor deficit. One week following surgery, digital subtraction angiography (DSA) was performed to identify the source of bleeding, which had not been apparent during the operation (Fig. 2). A dilation of a right spinal radicular artery along the lateral aspect of the spinal cord at the level of T5 was detected. Moreover, active bleeding form this pseudoaneurysm was noticed as a hyperdense spot in the spinal canal on XperCT (a spiral CT-like angiographic acquisition) images (Fig. 3,Fig. 4Figs. 3, 4 ). In consideration of the worsening of the motor deficit, taking into account the active bleeding, the patient underwent urgent repeat sur­ gery, with the aim of excluding the bleeding malformation. She was positioned prone and neurophysiological monitoring was prepared. The * Corresponding author. E-mail address: massimiliano.minardi@edu.unito.it (M. Minardi). https://doi.org/10.1016/j.clineuro.2021.106505 Received 2 December 2020; Received in revised form 13 January 2021; Accepted 15 January 2021 Available online 19 January 2021 0303-8467/© 2021 Elsevier B.V. All rights reserved. M. Minardi et al. Clinical Neurology and Neurosurgery 202 (2021) 106505 Fig. 1. A: pre-operative CT with upper cervical bleeding B pre-spinal decompression MR C post-spinal decompression MR. Fig. 2. Pre-operative DSA: black arrow selects the source of active bleeding. Fig. 3. XperCT in early phase post contrast enhancement (reconstruction with angiography’s CT imaging): A-B-C: axial, coronal and sagittal view, respectively, show hyperdense spot in the spinal canal that represent the pseudoaneurysm’s bleeding. 2 M. Minardi et al. Clinical Neurology and Neurosurgery 202 (2021) 106505 Fig. 4. XperCT in late phase post contrast enhancement (reconstruction with angiography’s CT imaging): A-B-C: coronal, axial and sagittal view, respectively, that show active bleeding from pseudoaneurysm. Fig. 5. post-operative DSA: complete exclusion of the radicular artery pseudoaneurysm. previous incision was used to reach the spinal canal and the dura mater was reopened along the previous suture line. The acute subdural he­ matoma was then thoroughly evacuated through a combination of irri­ gation and gentle aspiration. Once the spinal cord was adequately decompressed, subarachnoid dissection was performed, and the source of bleeding was identified from an enlarged radicular artery. Arachnoid adhesions were further dissected, in order to separate the malformation from surrounding structures. Direct compression of the fusiform enlargement of the blood vessel proved to arrest the bleeding. A temporary clip was positioned caudal to the pseudoaneurysm. Videoangiography with Indocyanine green (ICG) demonstrated cranial refill of the malformation. The temporary clip was then moved cranial to the pseudoaneurysm and repeat ICG videoangiography again demon­ strated perfusion of the malformation. As no eloquent vessel appeared to be arising from the malformation and adequate anastomoses were apparent form videoangiography, both parent vessels above and below the fusiform enlargement were coagu­ lated. No decrease of evocated potential was recorded on neurophysio­ logical monitoring. Finally, the malformation was removed after sharp separation of the two ends. Postoperative DSA confirmed complete exclusion of the radicular artery pseudoaneurysm one month after surgery (Fig. 5). In the suspi­ cion of a mycotic etiology of the aneurysm, an echocardiography was performed with negative results. The patient was discharged home after seven days from the operation, with no neurological deficit. 3. Discussion SSDH is a rare pathology that can result from different conditions (post-traumatic, iatrogenic, and spontaneous). In their review, H. de Beer et al. presented different features and etiologies of this type of bleeding; however, it was reported that no underlying cause could be 3 M. Minardi et al. Clinical Neurology and Neurosurgery 202 (2021) 106505 identified in 43 % of cases [1]. Nevertheless, vascular malformations should be considered in SSDH. Rupture of a spinal radicular artery aneurysm could be the source of bleeding, even if most the common presentation is SAH [2,3,7]. Rate of hemorrhage has been reported to be higher in isolated spinal aneurysms, than in spinal aneurysms associated with other vascular malformations [8]. The pathogenesis of spinal artery aneurysms is probably multifac­ torial; circulatory factors like increased arterial blood flow and hemo­ dynamic stress on the vessel wall definitely have an important role in the development of these lesions [9]. Most reported spinal radicular artery aneurysms have a diameter of less than 3 mm and are usually fusiform rather than saccular [7]. Spinal radicular artery aneurysms can often be associated with systemic conditions, such as neoplasms, Behçet disease [10], autoimmune diseases, infection, pregnancy, coarctation of aorta, fibromuscular dysplasia [2,3], and Moyamoya disease [11]. Due to the rarity of this type of lesion, no standard treatment guideline is available. Surgery and endovascular embolization have both been successfully employed, whereas conservative treatment remains controversial and might be considered depending on aneurysm features and patient clinical condition. Endovascular treatment with simple coiling is often adequate for spinal aneurysms. However, catheterization of smaller spinal arteries with lower flow rate may be technically challenging [7]. Alternatively, a surgical approach is commonly used for posteriorly localized aneurysms [12]. Specific features of the malformation are important for surgical planning: in fusiform aneurysms or in aneurysms without a clear neck, direct clipping may not be possible and often preservation of the parent vessel is not possible. In these cases, surgical resection can be performed with fair clinical outcome. In the presented case, we preferred a surgical approach over an endovascular one, because of the presence of a symptomatic acute subdural bleeding that compressed the spinal cord. Also, difficulties in reaching and closing the malformation with microcatheterization shif­ ted the choice towards a surgical procedure. After evacuation of the hematoma and spinal cord decompression, an important role in the surgical procedure was played by neurophysio­ logical monitoring and ICG videoangiography. The usefulness of neurophysiological monitoring during spinal surgery has widely been documented in the literature [13,14]: in our case motor evoked poten­ tials and somato-sensory evoked potentials remained constant during the surgical procedure, especially through temporary clipping of the parent vessels and after exclusion of the malformation. The importance of ICG videoangiography has recently been highlighted by Acerbi et al in a retrospective study, analyzing its use in the decision-making process of venous sacrifice [15]. ICG videoangiography can, in fact, provide valuable real-time intraoperative information regarding patient-specific vascular anatomy. neurological outcome. Spinal radicular artery aneurysms and pseudoaneurysms should be suspected in cases of subarachnoid or subdural hemorrhage, considering a surgical or, alternatively, an endovascular approach for their treatment. Funding None. References [1] M.H. de Beer, M.M. Eysink Smeets, H. Koppen, Spontaneous spinal subdural hematoma, Neurologist. 22 (2017) 34–39, https://doi.org/10.1097/ NRL.0000000000000100. [2] P. Marovic, N. Thani, S. Lu, A. Bala, Spinal subarachnoid hemorrhage secondary to rupture of an isolated radicular artery aneurysm, J. Neurol. Surg. A. Cent. Eur. Neurosurg. 74 (2013) 410–414, https://doi.org/10.1055/s-0032-1320025. [3] S.M. Priola, C. 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Focus 27 (2009), https://doi.org/10.3171/2009.8.FOCUS09150. E6. [15] F. Acerbi, I.G. Vetrano, T. Sattin, J. Falco, C. de Laurentis, C.M. Zattra, L. Bosio, Z. Rossini, M. Broggi, M. Schiariti, P. Ferroli, Use of ICG videoangiography and FLOW 800 analysis to identify the patient-specific venous circulation and predict the effect of venous sacrifice: a retrospective study of 172 patients, Neurosurg. Focus 45 (2018), https://doi.org/10.3171/2018.4.FOCUS18120. E7. 4. Conclusion A rare case of SSDH due to rupture of a spinal radicular artery was presented. Meticulous microsurgical technique, assisted by intra­ operative neurophysiological monitoring and ICG videoangiography, allowed for complete exclusion of the malformation with favorable 4