Secondary clinical deterioration after successful embolization of a spinal dural arteriovenous fistula: a plea for prophylactic anticoagulation

Spinal dural and epidural fistulas: role of cone beam CT in diagnosis and treatment

Understanding normal spinal arterial and venous anatomy, and spinal vascular disease, is impossible without flow-based methods. Development of practical spinal angiography led to site-specific categorization of spinal vascular conditions, defined by the 'seat of disease' in relation to the cord and its covers. This enabled identification of targets for highly successful surgical and endovascular treatments, and guided interpretation of later cross-sectional imaging.Spinal dural and epidural arteriovenous fistulas represent the most common types of spinal shunts. Although etiology is debated, anatomy provides excellent pathophysiologic correlation. A spectrum of fistulas, from foramen magnum to the sacrum, is now well-characterized.Most recently, use of cone beam CT angiography has yielded new insights into normal and pathologic anatomy, including venous outflow. It provides unrivaled visualization of the fistula and its relationship with spinal cord vessels, and is the first practical method to study normal and pathologic spinal veins in vivo-with multiple implications for both safety and efficacy of treatments. We advocate consistent use of cone beam CT imaging in modern spinal fistula evaluation.The role of open surgery is likely to remain undiminished, with increasing availability and use of hybrid operating rooms for practical intraoperative angiography enhancing safety and efficacy of complex surgery.

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.

Acute neurological deterioration after surgical interruption of spinal dural arteriovenous fistulas: clinical characteristics, possible predictors, and treatment. Patient series

BACKGROUND

Acute neurological deterioration develops paradoxically in some patients after obliteration of a spinal dural arteriovenous fistula (SDAVF), with thrombosis of the spinal cord veins as its primary cause. The authors aimed to clarify the clinical and radiological characteristics of acute deterioration to identify high-risk patients. They also discussed the optimal treatment for this complication.

OBSERVATIONS

Ten patients with SDAVF presenting with congestive myelopathy who received microsurgical interruption were retrospectively reviewed. Severe myelopathy developed in three patients on postoperative days 1 to 3. Anticoagulation therapy was effective; however, discontinuing anticoagulants under residual spinal cord congestion caused redeterioration. These patients were characterized by significantly extended transit time on angiography and significant prolongation of spinal cord congestion. Acute deterioration exhibited a strong correlation with transit time (coefficient, 0.825; p = 0.006) and a strong correlation with spinal cord edema before surgery (coefficient, 0.656; p = 0.040).

LESSONS

Acute deterioration after SDAVF treatment is likely to develop in patients with severe venous outflow impairment. Its pathology is prolonged spinal cord congestion caused by postoperative venous thrombosis and preexistent severe venous outflow impairment. Anticoagulation treatment should be continued for patients with acute deterioration until the resolution of spinal cord congestion is confirmed with magnetic resonance imaging.

Spinal vascular malformations: Angiographic evaluation and endovascular management

Spinal vascular malformations (SVM) are classified based on their location (intramedullary, perimedullary, radicular, extradural) and flow pattern (high-flow, low-flow, no arteriovenous shunt). High-flow SVMs are generally congenital lesions diagnosed in children and young patients without gender predominance. They present with hemodynamic disturbances, mass effect, or hemorrhages, but may also be discovered incidentally. Low-flow SVMs tend to be acquired lesions presenting in older men with progressive myelopathy caused by spinal venous hypertension. They are rarely associated with vascular syndromes but may accompany prothrombotic conditions. The sensitivity and specificity of conventional MRI are excellent for high-flow SVMs but poor for low-flow lesions, which are frequently diagnosed with extensive delays reducing the potential for favorable outcomes. The sensitivity of advanced MRI techniques remains unclear, notably for the detection of low-flow shunts without flow voids on conventional MRI. Catheter angiography remains the gold standard modality for the evaluation of the spinal vasculature and its disorders. SVMs can be treated by surgical or endovascular means. Initially plagued by high recurrence rates due to inadequate embolization material, endovascular techniques represent nowadays a valid alternative to surgery, thanks notably to the introduction of liquid embolic agents.

Introduction to Diagnostic and Therapeutic Spinal Angiography

This article describes the basic principles of diagnostic and therapeutic spinal angiography as practiced by the author, including catheterization and radioprotection techniques, the selection of endovascular devices and embolization agents, and procedural complications.

Republished: Primary intraventricular haemorrhage due to rupture of giant varix of the basal vein of Rosenthal in a patient with long-standing direct CCF: angiographic features and treatment considerations

Direct carotid cavernous fistulae (CCF) are often detected early and treated promptly resulting in a paucity of literature regarding its long-term evolution. We present a case of high flow post-traumatic direct CCF that was neglected for over 6 years and presented with a rare manifestation of primary intraventricular haemorrhage. Occlusions of the primary venous outlets likely resulted in engorgement of the deep venous system. The segmental anatomy of the shunting basal vein is critical to the clinical presentation and may range from basal ganglia or brainstem oedema/infarctions to uniquely, as in our case, isolated intraventricular haemorrhage secondary to variceal rupture. Treatment in such chronic cases requires a consideration of cerebral hyperperfusion syndrome necessitating deconstructive techniques with subsequent anticoagulation to avoid accelerated thrombosis of the venous varices.

Asymptomatic spinal dural arteriovenous fistula: case series and systematic review

OBJECTIVE

Spinal dural arteriovenous fistulas (SDAVFs) commonly present with symptoms of myelopathy due to venous congestion in the spinal cord; asymptomatic SDAVFs are rarely encountered. To elucidate the clinical characteristics of asymptomatic SDAVFs, the authors present 5 new cases of asymptomatic SDAVF and report the results of their systematical review of the associated literature.

METHODS

Five databases were systematically searched for all relevant English-language articles on SDAVFs published from 1990 to 2018. The clinical features and imaging findings of asymptomatic SDAVFs were collected and compared with those of symptomatic SDAVFs.

RESULTS

Twenty cases, including the 5 cases from the authors' experience, were found. Asymptomatic SDAVFs were more prevalent in the cervical region (35.0%); cervical lesions account for only 2% of all symptomatic SDAVFs. The affected perimedullary veins tended to drain more cranially (50.0%) than caudally (10.0%). Four cases of asymptomatic SDAVF became symptomatic, 1 case spontaneously disappeared, and the remaining 15 cases were unchanged or surgically treated.

CONCLUSIONS

The higher prevalence of asymptomatic SDAVFs in the cervical spine might be a distinct feature of asymptomatic SDAVFs. Given that venous congestion is the pathophysiology of a symptomatic SDAVF, abundant collateral venous pathways and unique flow dynamics of the CSF in the cervical spine might prevent asymptomatic cervical SDAVFs from becoming symptomatic. In cases in which venous congestion is avoidable, not all asymptomatic SDAVFs will become symptomatic.

Clinical outcomes and prognostic factors in patients with spinal dural arteriovenous fistulas : a prospective cohort study in two Chinese centres

BACKGROUND

The short-term outcomes and prognostic factors of patients with spinal dural arteriovenous fistulas (SDAVFs) have not been defined in large cohorts.

OBJECTIVE

To define the short-term clinical outcomes and prognostic factors in patients with SDAVFs.

METHODS

A prospective cohort of 112 patients with SDAVFs were included consecutively in this study. The patients were serially evaluated with the modified Aminoff and Logue's Scale (mALS) one day before surgery and at 3 months, 6 months and 12 months after treatment. Univariate and multivariate analyses were performed to identify demographic, clinical and procedural factors related to favourable outcome.

RESULTS

A total of 94 patients (mean age 53.5 years, 78 were men) met the criteria and are included in the final analyses. Duration of symptom ranged from 0.5 to 66 months (average time period of 12.7 months). The location of SDAVFs was as follows: 31.6% above T7 level, 48.4% between T7 and T12 level (including T7 and T12) and 20.0% below T12 level. A total of 81 patients (86.2%) underwent neurosurgical treatment, 10 patients (10.6%) underwent endovascular treatment, and 3 patients (3.2%) underwent neurosurgical treatment after unsuccessful embolisation. A total of 78 patients demonstrated an improvement in mALS score of one point or greater at 12 months. Preoperative mALS score was associated with clinical improvement after adjusting for age, gender, duration of symptoms, location of fistula and treatment modality using unconditional logistic regression analysis (p<0.05).

CONCLUSION

Approximately four fifths of the patients experienced clinical improvement at 12 months and preoperative mALS was the strongest predictor of clinical improvement in the cohort.

Primary intraventricular haemorrhage due to rupture of giant varix of the basal vein of Rosenthal in a patient with long-standing direct CCF: angiographic features and treatment considerations

Direct carotid cavernous fistulae (CCF) are often detected early and treated promptly resulting in a paucity of literature regarding its long-term evolution. We present a case of high flow post-traumatic direct CCF that was neglected for over 6 years and presented with a rare manifestation of primary intraventricular haemorrhage. Occlusions of the primary venous outlets likely resulted in engorgement of the deep venous system. The segmental anatomy of the shunting basal vein is critical to the clinical presentation and may range from basal ganglia or brainstem oedema/infarctions to uniquely, as in our case, isolated intraventricular haemorrhage secondary to variceal rupture. Treatment in such chronic cases requires a consideration of cerebral hyperperfusion syndrome necessitating deconstructive techniques with subsequent anticoagulation to avoid accelerated thrombosis of the venous varices.

Intracranial non-galenic pial arteriovenous fistula: A review of the literature

An intracranial non-galenic pial arteriovenous fistula (NGPAVF) is a direct connection between the intracranial artery and vein without a nidus. NGPAVFs are clinically rare, and the current understanding of NGPAVFs is limited. This study searched PubMed for the currently available literature, and a review of the relevant publications revealed that NGPAVFs require aggressive treatment, spontaneous occlusion is uncommon, and the prognosis following conservative treatment is poor. NGPAVFs can be divided into congenital and traumatic (including iatrogenic) types. Clinically, NGPAVFs are characterized by congestive heart failure, epilepsy, hemorrhage, mass effects, and nerve function deficits. For the imaging examination of NGPAVFs, digital subtraction angiography (DSA) is still the gold standard for diagnosis, although magnetic resonance DSA (MRDSA) and 4D computed tomography angiography (CTA) can also provide hemodynamic data in a non-invasive manner. Current treatments for NGPAVFs include surgical resection and endovascular embolization, both of which can yield clinical improvements. However, potential postoperative complications should be addressed, such as fatal bleeding due to rupture and deep vein thrombosis. Some studies recommend postoperative anticoagulation to reduce postoperative thrombotic complications.

Analysis of the embolization spinal dural arteriovenous fistula and surgical treatments on 52 cases of the patients

BACKGROUND

Spinal dural arteriovenous fistula (SDAVF) highly threatens people's life and health. Effective methods for the diagnosis and treatment of the disease are badly needed in clinical application.

OBJECTIVE

The objective of the present study was to sum up the diagnosis and treatment method of SDAVF to improve the diagnosis and treatment effect of the disease.

METHODS

The epidemiological data, imaging data, therapeutic methods and postoperative follow-up data of 52 cases of patients with SDAVF received in our hospital in recent 6 years were collected and retrospectively analyzed.

RESULTS

There were 43 male patients and 9 female patients with ages of 39-77 years and average age of 59.6 years. The course of disease was 1 to 48 months with an average disease course of 14.4 months. All the patients had syndromes of lower limb numbness, pain, weakness and other sensory and movement disorders mostly accompanied with defecation dysfunction. Magnetic resonance imaging (MRI) results demonstrated that spinal cord abnormalities were found in spinal cord, which could be diagnosed by digital subtraction angiography (DSA) examination. There were 40 cases received surgical treatment and there was no recurrence in the follow-up. There were 12 patients received embolotherapy, of whom 3 patients were operated the second time and 2 patients had embolization again. After 0.5-6 years of follow-up, postoperative symptoms of the 40 patients were improved in different degrees. The modified Aminoff-Logue function scoring was significantly decreased after treatment.

CONCLUSION

SDAVF is the easily diagnosed and delayed spinal cord vascular lesions in clinical applications. The diagnosis relies mainly on MRI and DSA examinations. The surgical treatment effect is good and is not easily relapsed. The trauma of the interventional embolization treatment is small, but the recurrence rate is high.

Rapid and progressive venous thrombosis after occlusion of high-flow arteriovenous fistula

BACKGROUND

Cerebral venous thrombosis developing after surgical or endovascular obliteration of arteriovenous fistula (AVF) is a rare but devastating complication that has not been adequately reported.

CASE DESCRIPTION

Two patients presenting with AVF (1 pial, 1 dural) and large venous pouches were successfully treated by surgical and endovascular means and were neurologically intact postoperatively. Rapid neurologic deterioration was seen on postoperative day 5 in the first patient and postoperative day 2 in the second patient. Both patients had massive cerebral venous thromboses on brain imaging and surgical exploration. One patient died and the other was severely disabled.

CONCLUSION

Rapid occlusion of a high-flow AVF resulting in significant venous stasis can precipitate thrombosis of the venous system distal to the fistulous point. In the presence of large venous pouches and significant venous stasis, strict therapeutic anticoagulation may be required to prevent cerebral venous thrombosis. Therapeutic anticoagulation, though feasible following endovascular treatment, may prove particularly challenging after open surgical interventions given the risk of hemorrhagic complications.