The Preventive Effect of Endovascular Treatment for Recurrent Hemorrhage in Patients with Spinal Cord Arteriovenous Malformations

Perioperative Management of Spinal Arteriovenous Malformation Embolization: Delayed Venous Thrombosis and Implications for Severe Back Pain

BACKGROUND AND PURPOSE

The prognosis of untreated spinal arteriovenous malformations (SAVMs) is poor. Embolization plays an important role in the management of intramedullary SAVMs. Delayed aggravation due to spinal venous thrombosis following successful embolization has been reported; however, perioperative management strategies to prevent thrombosis have not been explored. We present our single-center experience of SAVM embolization and perioperative management, including anticoagulation.

MATERIAL AND METHODS

We retrospectively evaluated 18 patients with SAVMs who underwent transarterial embolization. Perioperative anticoagulation therapy was administered to selected patients. We compared the characteristics of the patients, including perioperative management procedures, between those with and without postoperative worsening following embolization.

RESULTS

Acute postoperative worsening within 1 week occurred in 4 (22.2%) patients. Of these, immediate worsening was observed in one patient as a procedure-related complication. Delayed worsening after 24 h was observed in 3 patients, caused by delayed venous thrombosis with severe back pain. Rescue anticoagulation for delayed worsening improved symptoms in two patients. A comparison between patients with and without acute postoperative worsening revealed significant differences in age (median 46.5 vs. 26.5 years, p = 0.009) and the presence of postoperative back pain (75.0% vs. 0%, p = 0.005); however, there was no significant difference in use of selective anticoagulation (p = 0.274).

CONCLUSION

The results of this study suggest that SAVM embolization can cause acute worsening due to postoperative venous thrombosis with severe back pain, which may be reversed by anticoagulation therapy. Back pain is an important finding that suggests venous thrombosis, and anticoagulation should be urgently administered.

Long term follow-up of endovascular management of spinal cord arteriovenous malformations with emphasis on particle embolization

Objective

To determine long term safety and efficacy of endovascular treatment of spinal cord arteriovenous malformations (AVMs), with calibrated particle embolization as a firstline approach.

Methods

We reviewed clinical and imaging data of consecutive patients who underwent endovascular treatment for both nidal and fistulous type spinal cord AVMs in our center, from 1990 to 2015. Outcome at the last follow-up was assessed by an independent observer.

Results

Embolization of spinal cord AVMs was performed in 61 patients, including 46 (75%) with particles (exclusively in 29 patients), 30 (49%) with cyanoacrylate, and 6 (10%) with combined surgical treatments. Particle embolizations were iterative in 33 patients (median number of sessions 5 (range 3–6)). Neurological deterioration after treatment occurred in 5 patients (cyanoacrylate=4, surgery=1, particles=0; P<0.001). At a median follow-up of 6 years (range 3–13 years), angiographic cure was obtained in 11/61 (18%) patients (nidal type=6/53 (11%), fistulous type=5/8 (63%)). In progressive forms, neurological improvement occurred in 16/28 (57%) patients, stabilized in 9/28 (31%), and worsened in 3/28 (12%). In hemorrhagic forms, the rebleeding rate was 4/14 patient years without standard treatment, 0/322 patient years in partial iterative treatment, and 0/15 patient years in angiographically cured lesions (P=0.001).

Conclusion

Our study suggests that particle embolization as a firstline therapy to treat spinal cord AVMs is safe and offers long term efficacy, especially for those with small, distal, and multiple shunts. Partial occlusion of the AVM may be sufficient to prevent rebleeding, without the potential risks of complete occlusion. Particle calibration and injection technique, ‘one by one’, are critical to safety. Cyanoacrylate embolization or surgery remains necessary if particle embolization fails to occlude large shunts.

Visualization of mouse spinal cord intramedullary arteries using phase- and attenuation-contrast tomographic imaging

Many spinal cord circulatory disorders present the substantial involvement of small vessel lesions. The central sulcus arteries supply nutrition to a large part of the spinal cord, and, if not detected early, lesions in the spinal cord will cause irreversible damage to the function of this organ. Thus, early detection of these small vessel lesions could potentially facilitate the effective diagnosis and treatment of these diseases. However, the detection of such small vessels is beyond the capability of current imaging techniques. In this study, an imaging method is proposed and the potential of phase-contrast imaging (PCI)- and attenuation-contrast imaging (ACI)-based synchrotron radiation for high-resolution tomography of intramedullary arteries in mouse spinal cord is validated. The three-dimensional vessel morphology, particularly that of the central sulcus arteries (CSA), detected with these two imaging models was quantitatively analyzed and compared. It was determined that both PCI- and ACI-based synchrotron radiation can be used to visualize the physiological arrangement of the entire intramedullary artery network in the mouse spinal cord in both two dimensions and three dimensions at a high-resolution scale. Additionally, the two-dimensional and three-dimensional vessel morphometric parameter measurements obtained with PCI are similar to the ACI data. Furthermore, PCI allows efficient and direct discrimination of the same branch level of the CSA without contrast agent injection and is expected to provide reliable biological information regarding the intramedullary artery. Compared with ACI, PCI might be a novel imaging method that offers a powerful imaging platform for evaluating pathological changes in small vessels and may also allow better clarification of their role in neurovascular disorders.

Pediatric spinal arteriovenous malformations and fistulas: a single institute's experience

OBJECTIVE

Pediatric spinal vascular diseases are extremely rare. We aimed to evaluate their clinical characteristics and treatment outcomes in our institute.

DESIGN

A total of 10 patient files were retrospectively reviewed, including 3 cases of intramedullary arteriovenous malformations (AVMs), 6 cases of perimedullary arteriovenous fistulas (AVFs), and 1 case of epidural AVF. Clinical features, radiological findings, treatment results, and clinical outcomes were evaluated. The median durations of the radiologic and clinical follow-ups were 17.7 and 107.9 months, respectively.

RESULTS

The male to female ratio was 1:1, with a median age at diagnosis of 9 years. All AVMs were juvenile type, all perimedullary AVFs were high flow types (three type IVb and three type IVc), and one epidural AVF was associated with intradural venous drainage. Most cases (90 %) were located in the cervical spine and conus medullaris. Acute neurological deterioration was identified in five patients; however, bleeding was identified in only one patient. Two cases were surgically treated, seven cases underwent embolization, and one case underwent radiosurgery. Three cases were completely obliterated, and their clinical states were improved (n = 2; 66.7 %) and stationary (n = 1; 33.3 %). Meanwhile, seven cases were incompletely obliterated, and their clinical states were improved (n = 2; 28.6 %), stationary (n = 3; 42.8 %), and aggravated (n = 2; 28.6 %).

CONCLUSIONS

Pediatric spinal AVMs and AVFs were mostly complex and high flow types, and complete obliteration could not be satisfactorily achieved. Incompletely treated lesions should be closely followed up because they may worsen.