The validity of intraoperative angiography for the treatment of spinal arteriovenous fistula. ACTA ACUST UNITED AC. 2007;20:442-448. [PMID: 17970185 DOI: 10.1097/bsd.0b013e318031afa1]

Spinal Dorsal Intradural Arteriovenous Fistulas: Natural History, Imaging, and Management

In this review, we describe the pathophysiology, diagnosis, and treatment of spinal dorsal intradural arteriovenous fistulas (DI-AVFs), focusing on novel research areas. DI-AVFs compose the most common subgroup of spinal arteriovenous lesions and most commonly involve the thoracic spine, followed by lumbar and sacral segments. The pathogenesis underlying DI-AVFs is an area of emerging understanding, thought to be attributable to venous congestion and hypertension that precipitate ascending myelopathy. Patients with DI-AVFs typically present with motor, sensory, or urinary dysfunction, although a wide swath of other less common symptoms has been reported. DI-AVFs can be subdivided by spinal region, which in turn is associated with 4 distinct clinical phenotypes: craniocervical junction (CCJ), subaxial cervical, thoracic, and lumbosacral. Patients with CCJ and lumbosacral DI-AVFs have particularly interesting presentations and treatment considerations. High-value diagnostic findings on MRI include flow voids, missing-piece sign, and T2-weighted intramedullary hyperintensity. However, digital subtraction angiography is the gold standard for diagnosis and localization of DI-AVFs and for definitive treatment planning. Surgical disconnection of DI-AVFs is almost universally curative and frontline treatment, especially for CCJ and lumbosacral DI-AVFs. Endovascular techniques evolve in promising ways, such as improved visualization, distal access, and liquid embolic techniques. The pathophysiology of DI-AVFs is better understood using newly identified radiologic diagnostic markers. Despite new techniques and devices introduced in the endovascular field, surgery remains the gold-standard treatment for DI-AVFs.

Intraoperative angiography during neurosurgical procedures on patients in prone, three-quarters prone, and park-bench positions: tertiary single-center experience with systematic review and meta-analysis

BACKGROUND

There is limited evidence about the role and effectiveness of intraoperative angiography (IOA) during neurosurgical procedures with patients in prone, three-quarters prone, and park-bench positions.

OBJECTIVE

To carry out a systematic review and meta-analysis of the literature to evaluate the safety and efficacy of IOA during neurosurgical procedures.

METHODS

We reviewed (between January 1960 and July 2022) all studies in which IOAs were performed during neurosurgical procedures with patients in either prone, three-quarters prone, or park-bench positions. Additionally, a cohort of patients from our institutional experience was included. Efficacy outcomes were the rate of successful angiography and the rate of surgical adjustment/revision after IOA. Safety outcomes were the rate of angiography-related complications and mortality. Data were analyzed using a random-effects meta-analysis of proportions, and statistical heterogeneity was assessed.

RESULTS

A total of 26 studies with 142 patients plus 32 subjects from our institution were included in the analysis. The rate of successful intraoperative angiography was 98% (95% CI 94% to 99%; I²=0%). The rate of surgical adjustment/revision was 18% (95% CI 12% to 28%; I²=0%). The rate of complications related to the angiography was 1% (95% CI 0% to 5%; I²=0%). There were no deaths associated with IOA.

CONCLUSION

We found that IOA performed with patients in prone, three-quarters prone, and park-bench positions is feasible and safe with a non-negligible rate of intraoperative post-angiographical surgical adjustment/revision. Our findings suggest that the performance of IOA to complement vascular neurosurgical procedures might have a valuable role in favoring patient outcomes.

Resection of ruptured spinal pial arteriovenous fistula under ultrasound control: how I do it

BACKGROUND

Spinal pial arteriovenous fistulae are rare intradural superficial vascular lesion consisting in a direct shunt between spinal pial arteries and veins. The presentation of pial arteriovenous fistula is caused by venous congestion with spinal cord ischemia, mass effect, or hemorrhage. The treatment is surgery or endovascular procedure.

METHODS

We illustrate the case of thoracic pial arteriovenous fistula in a 66-year-old female operated with posterior midline approach and B-mode US.

CONCLUSION

Posterior midline approach with targeted laminotomy using high-speed drill affords an ideal surgical exposure. B-mode US is helpful to detect the fistula and study their relationship with the surrounding structures.

Application of hybrid operating rooms for treating spinal dural arteriovenous fistula

BACKGROUND

A hybrid operating room (hybrid-OR) is a surgical space that combines a conventional operating room with advanced medical imaging devices.

AIM

To explore and summarize the technical features and effectiveness of the application of a hybrid-OR in dealing with spinal dural arteriovenous fistulas (SDAVFs).

METHODS

Eleven patients with SDAVFs were treated with the use of a hybrid-OR at the Department of Neurosurgery of our hospital between January 2015 and December 2018. The dual-marker localization technique was used in the hybrid-OR to locate the SDAVFs and skin incision, and the interoperative digital subtraction angiography (DSA) technique was used before and after microsurgical ligation of the fistulae in the hybrid-OR to verify the accuracy of obliteration. The patients were followed for an average of 2 years after the operation, and the preoperative American Spinal Cord Injury Association (ASIA) score and postoperative ASIA score at 6 mo after the operation were compared.

RESULTS

The location and skin incision of the SDAVFs were accurately obtained by using the dual-marker localization technique in the hybrid-OR in all patients, and there were no cases that required expansion of the range of the bone window in order to expose the lesions. Intraoperative error obliteration occurred and was identified in two patients by using the intraoperative DSA technique; therefore, the findings provided by the intraoperative DSA system significantly changed the surgical procedure in these two patients. With the assistance of the hybrid-OR, the feeding artery was correctly ligated in all cases, and the intraoperative error obliteration rate decreased from 18.2% (2/11) to 0%. All 11 patients were followed for an average of 2 years. The ASIA score at 6 mo after the operation was significantly improved compared with the preoperative ASIA score, and there were no patients with late recurrence during the follow-up.

CONCLUSION

Compared with intra-arterial embolization for the treatment of SDAVFs, hybrid-ORs can solve the problem of a higher incidence of initial failure and late recurrence. Compared with direct occlusion of SDAVFs in microsurgery, hybrid-ORs can take advantage of the intraoperative DSA system for locating the shunt and verifying the obliteration of fistulae in order to reduce the error obliteration rate. At this point, our experience suggests that the safety and ease of use make hybrid-ORs combined with microsurgery and intraoperative DSA systems an attractive modality for dealing with SDAVFs.

Efficacy of Intraarterial Fluorescence Video Angiography in Surgery for Dural and Perimedullary Arteriovenous Fistula at Craniocervical Junction

OBJECTIVE

Confirming the exact location of a fistula and the origins of draining veins during surgery for dural and perimedullary arteriovenous fistulas (AVFs) is crucial but sometimes inadequately performed, which can result in incomplete elimination of the lesion. Intraoperative digital subtraction angiography (DSA) is the gold standard for confirming the hemodynamics of an AVF; however, it cannot reveal the location of an AVF in the operative field. In this study, the efficacy of intraoperative intraarterial fluorescence video angiography during surgery for craniocervical junction dural and perimedullary AVFs was investigated.

METHODS

We repeatedly employed this technology to evaluate its usefulness in revealing the flow dynamics and anatomy of AVFs and to confirm complete elimination of the fistula.

RESULTS

Seven AVFs were included in this study. Their locations were C1 in 5 cases and C2 in 2 cases. Intraarterial fluorescence video angiography precisely revealed the locations of 3 dural AVFs, 1 perimedullary AVF, and 3 co-occurring dural and perimedullary AVFs. Frame-by-frame review of the fluorescence video angiography clearly demonstrated that fluorescence appeared earlier in the perimedullary AVF than in the draining vein through the dural AVF after intraarterial injection in all 3 co-occurring cases. Complete elimination of the AVF was also confirmed in all cases by fluorescence video angiography, as well as intraoperative and follow-up DSA.

CONCLUSIONS

Intraarterial fluorescence video angiography, particularly frame-by-frame review, enables surgeons to distinguish the flow dynamics of AVFs and contributes to the planning of effective surgical strategies for optimal results.

Study and therapeutic progress on spinal cord perimedullary arteriovenous fistulas

Spinal cord perimedullary arteriovenous fistulas (PMAVFs) are rare and belong to type IV spinal cord arteriovenous malformations (AVMs). Little is known regarding the treatment and prognosis of spinal cord PMAVFs. In the present study the relevant literature from PubMed was reviewed, and it was found that these fistulas can occur at all ages but are more common in children. In children, most spinal cord PMAVFs are large and with high flow, begin with bleeding and are frequently associated with hereditary hemorrhagic telangiectasia. However, in adults, most spinal cord PMAVFs are small and with low flow and begin with progressive spinal cord dysfunction. The early diagnosis of spinal cord PMAVFs is generally difficult, and symptoms can be very severe at the time of diagnosis. Digital subtraction angiography remains the gold standard; however, computed tomography angiography and magnetic resonance angiography are also promising. Spinal cord PMAVFs can be treated by endovascular embolization, surgical removal or a combination of the two methods. Most spinal cord PMAVFs show good outcomes after the appropriate treatment, and the prognosis is primarily associated with the blood flow of the PMAVF. For high-flow spinal cord PMAVFs, endovascular embolization is more effective and can lead to a good outcome; however, for low-flow spinal cord PMAVFs, surgical removal or the combination with endovascular embolization is the optimal choice. The prognosis for low-flow types is slightly worse than for high-flow spinal cord PMAVFs in children, but the outcome is acceptable.

Intraoperative Imaging for Vascular Lesions

Neurovascular surgery is a broad and challenging, yet exciting field within neurologic surgery. The neurovascular surgeon must be meticulous; because the brain and spinal cord are unforgiving to ischemic insults. Along with the pressures of this demanding subspecialty comes the potential to help patients recover from potentially devastating pathology to go on and lead normal, healthy lives. Several intraoperative imaging modalities are available to help maximize treatment success while reducing risk. This article reviews each of these modalities, including digital subtraction angiography, fluorescence angiography, Doppler ultrasonography, laser Doppler, laser speckle contrast imaging, neuronavigation, and neuroendoscopy.

Intraoperative spinal digital subtraction angiography: indications, technique, safety, and clinical impact

Background

Cerebral intraoperative DSA (IODSA) is a well-described, routinely performed procedure that allows the effectiveness of cerebrovascular interventions to be evaluated in the operating room. Spinal IODSA, on the other hand, is infrequently obtained and has received less attention.

Objective

To discuss the indications, technique, safety, and clinical impact of spinal IODSA.

Materials and methods

Twenty-three patients underwent 45 thoracic and/or lumbar spinal IODSA between 2005 and 2016, either immediately before surgery for lesion localization or after the intervention to evaluate its effectiveness. Indications included 21 vascular malformations and 2 diaphragmatic crus compression syndromes. A long femoral arterial sheath with its hub positioned on the lateral surface of the thigh was used to allow catheter manipulations in the prone position.

Results

All targeted intersegmental arteries (ISAs) were successfully catheterized. The course of surgery was changed in 6 instances (26.1%). In 4 cases of epidural or perimedullary arteriovenous fistulae (AVFs), a residual lesion required additional intervention. In one case of epidural AVF, initial IODSA revealed spontaneous resolution of the lesion, preventing unnecessary surgery. Finally, angiography performed in a case of diaphragmatic crus syndrome showed thrombosis of the ISA and non-visualization of the artery of Adamkiewicz. Recanalization was obtained by IA thrombolysis, with excellent clinical outcome. No intraprocedural or postprocedural complication was noted.

Conclusions

Spinal IODSA is a safe technique that offers an immediate assessment of the effectiveness of a spinovascular surgical procedure, notably epidural and perimedullary AVFs. Spinal IODSA was technically successful in all cases, influencing the surgical strategy in 6 of 23 patients, including one patient who benefited from intraoperative endovascular therapy.

Intramedullary hemorrhage from a thoracolumbar dural arteriovenous fistula

BACKGROUND CONTEXT

Spinal dural arteriovenous fistulas (AVFs) are acquired lesions presenting typically with neurologic deficits secondary to chronic congestive myelopathy. The low-flow and low-volume nature of these lesions makes hemorrhage very unlikely, and intramedullary hemorrhage caused by thoracolumbar dural AVFs is exceedingly rare.

PURPOSE

The purpose of this study was to report a case of intramedullary hemorrhage caused by a thoracolumbar dural AVF.

STUDY DESIGN/SETTING

The study design included a case report and review of literature.

METHODS

A case of intramedullary hemorrhage from a thoracolumbar dural AVF was reported, and the literature regarding hemorrhagic presentations of dural AVF was reviewed.

RESULTS

A 66-year-old woman presented with a sudden onset of abdominal pain, paraplegia, sensory loss below the costal margins, and urinary retention. Magnetic resonance imaging scan showed intramedullary hemorrhage with abnormal flow voids raising suspicion of an intramedullary AV malformation. However, subsequent selective spinal angiography demonstrated a spinal dural AVF fed by the T7 intercostal artery and a varix within the draining vein. Complete obliteration of the dural AVF and the varix was achieved via embolization. As far as we are aware, there are only two other similar cases in the literature. Literature review revealed that presentation of thoracolumbar dural AVFs with hemorrhage is frequently associated with accelerated venous flow and the presence of a venous varix.

CONCLUSIONS

Although very unusual, a spinal dural AVF may present with intramedullary hemorrhage, and hemorrhage in such conditions may be associated with an accelerated venous flow and the presence of a venous varix.

Indocyanine green videoangiography "in negative": definition and usefulness in spinal dural arteriovenous fistulae

PURPOSE

Indocyanine green videoangiography (IGV) has proven its effectiveness in the field of exovascular neurosurgery, both in the intracranial and spinal compartment, but is necessary to define a systematic process for the performance of the IGV to facilitate its interpretation during the procedure. We have defined and applied the concept of videoangiography "in negative" (INIGV) to spinal dural arteriovenous fistulae (dAVF) for the detection and treatment of arteriovenous shunts, so called because the first phase is performed with the vessel suggestive of being pathological occluded.

METHODS

A Pentero-operating microscope with near-infrared IGV-integrated system (Carl Zeiss Co., Germany) was used. At our institution, 24 patients were treated for a spinal dAVF between 1995 and 2011, only in the last 4 cases, INIGV was performed.

RESULTS

We describe the IGV in negative procedure and show the most illustrative cases. In all cases, the fistula occlusion was confirmed by postoperative selective digital subtraction angiography (DSA). INIGV demonstrate its capacity in detecting vessels not actually arterialized that should be respected and avoid some of the main limitations of the conventional IGV. This is a technical description about an Indocyanine green (ICG) videoangiographic procedure modification that is superior to merely performing ICG before and after clipping of a dAVF.

CONCLUSION

The INIGV results are rapid and easy to interpret procedure and provide great advantages to the dAVF treatment. Nevertheless, further studies are needed with a larger sample size to determine if INIGV may reduce the need to perform immediate postoperative DSA.

Selective intraarterial injection of ICG for fluorescence angiography as a guide to extirpate perimedullary arteriovenous fistulas

BACKGROUND

Fluorescence angiography with indocyanine green (ICG) provides real-time information regarding the patency of vessels. To enhance the capability to delineate flow direction, flow velocity and sequence of dye filling in different components of complex spinal vascular lesions such as perimedullary arteriovenous fistulas (AVFs), we tried selective intraarterial injection of ICG with catheterization in the proximity of the AVFs.

METHOD

Prior to taking the position for surgery, a metallic introducer sheath was placed into the femoral artery, and placed over the patient's lateral buttock. After the exposure of the AVFs, a standard angiographic catheter was advanced into the proximal portion of the feeding artery and a small volume of diluted ICG (0.06 mg in 5 ml saline for one examination) injected repeatedly. To avoid the thromboembolism, heparinized saline was perfused continuously thorough the catheter and sheath.

FINDINGS

The small injection volume and the close proximity of the injection site to the lesions resulted in quick rise and fall of the fluorescence without any background. Time and spatial resolution of analysis were enhanced; flow dynamics such as direction, velocity and alteration after temporary occlusion were well visualized. The feeders and drainers were clearly distinguished, and the shunts could be precisely identified.

CONCLUSIONS

Selective intraarterial injection ICG fluorescence angiography was very useful for perimedullary AVFs. Albeit that it requires intraoperative selective catheterization, this repeatable technique has an advantage to improve temporary resolution and provides accurate information of the flow dynamics through the complex anatomy of vascular lesions.

Indocyanine green videoangiography in the management of dural arteriovenous fistulae

OBJECTIVE

To evaluate the usefulness of indocyanine green (ICG) videoangiography in the operative management of dural arteriovenous fistulae (dAVFs).

METHODS

Intraoperative ICG videoangiography was used as a surgical adjunct in 25 patients with cranial and spinal dural arteriovenous fistulae to identify the fistula and verify its complete obliteration. The findings on ICG videoangiography were compared with intraoperative and/or postoperative imaging.

RESULTS

All dural arteriovenous fistulae were clearly identified by intraoperative ICG videoangiography and obliteration was documented in each case. Findings on ICG videoangiography correlated with intraoperative and/or postoperative imaging.

CONCLUSION

ICG videoangiography is a useful adjunct to the surgical management of dural arteriovenous fistulae for localization and confirmation of complete obliteration. The safety and ease of use make it an attractive modality. The surgeon can only evaluate what is visualized under the operating microscope and must therefore fully expose the venous drainage of the fistula to confirm obliteration.

Advanced noninvasive imaging of spinal vascular malformations

Spinal vascular malformations (SVMs) are an uncommon, heterogeneous group of vascular anomalies that can render devastating neurological consequences if they are not diagnosed and treated in a timely fashion. Imaging SVMs has always presented a formidable challenge because their clinical and imaging presentations resemble those of neoplasms, demyelination diseases, and infection. Advancements in noninvasive imaging modalities (MR and CT angiography) have increased during the last decade and have improved the ability to accurately diagnose spinal vascular anomalies. In addition, intraoperative imaging techniques have been developed that aid in the intraoperative assessment before, during, and after resection of these lesions with minimal and/or optimal use of spinal digital subtraction angiography. In this report, the authors review recent advancements in the imaging of SVMs that will likely lead to more timely diagnoses and treatment while reducing procedural risk exposure to the patients who harbor these uncommon spinal lesions.