Intraarterial cyanoacrylate: an adjunct in the treatment of spinal/paraspinal arteriovenous malformations

Bioadhesive Technology Platforms

Bioadhesives have emerged as transformative and versatile tools in healthcare, offering the ability to attach tissues with ease and minimal damage. These materials present numerous opportunities for tissue repair and biomedical device integration, creating a broad landscape of applications that have captivated clinical and scientific interest alike. However, fully unlocking their potential requires multifaceted design strategies involving optimal adhesion, suitable biological interactions, and efficient signal communication. In this Review, we delve into these pivotal aspects of bioadhesive design, highlight the latest advances in their biomedical applications, and identify potential opportunities that lie ahead for bioadhesives as multifunctional technology platforms.

Endovascular management of arteriovenous malformations

Arteriovenous malformation (AVM) embolization can serve as a crucial adjunct before surgical resection, a partial approach to target high-risk features, or, rarely, as a curative approach for high-risk, surgically inaccessible lesions. Specifically, embolization is a welcome surgical adjunct to reduce the size of medium to large AVMs, to target perforator supply, and/or to target the deep portion of a nidus. In addition, a crucial role for embolization is the targeting of associated aneurysms, particularly in the setting of a ruptured lesion, regardless of the subsequent therapeutic modality. Rarely, a deep, small ruptured AVM that cannot be accessed surgically may be embolized with intent to cure. This chapter will review patient selection, technical nuances, and published results for AVM embolization. With appropriate patient selection and well-defined goals of embolization, the risk of procedural morbidity can be outweighed by its benefit.

Evolution of treatment and a detailed analysis of occlusion, recurrence, and clinical outcomes in an endovascular library of 260 dural arteriovenous fistulas

OBJECTIVE Many small series and technical reports chronicle the evolution of endovascular techniques for cranial dural arteriovenous fistulas (dAVFs) over the past 3 decades, but reports of large patient series are lacking. The authors provide a thorough analysis of clinical and angiographic outcomes across a large patient cohort. METHODS The authors reviewed their endovascular database from January 1996 to September 2015 to identify patients harboring cranial dAVFs who were treated initially with endovascular approaches. They extracted demographic, presentation, angiographic, detailed treatment, and long-term follow-up data, and they evaluated natural history, initial angiographic occlusion, complications, recurrence, and symptomatic resolution rates. RESULTS Across a cohort of 251 patients with 260 distinct dAVFs, the overall initial angiographic occlusion rate was 70%; recurrence or occult residual lesions were seen on subsequent angiography in 3% of cases. The overall complication rate was 8%, with permanent neurological complications occurring in 3% of cases. Among 102 patients with dAVFs without cortical venous reflux, rates of resolution/improvement of pulsatile tinnitus and ocular symptoms were 79% and 78%, respectively. Following the introduction of Onyx during the latter half of the study period, the number of treated dAVFs doubled; the initial angiographic occlusion rate increased significantly from 60% before the use of Onyx to 76% after (p = 0.01). In addition, during the latter period compared with the pre-Onyx period, the rate of dAVFs obliterated via a transarterial-only approach was significantly greater (43% vs 23%, p = 0.002), as was the number of dAVFs obliterated via a single arterial pedicle (29% vs 11%, p = 0.002). CONCLUSIONS Overall, in the Onyx era, the rate of initial angiographic occlusion was approximately 80%, as was the rate of meaningful clinical improvement in tinnitus and/or ocular symptoms after initial endovascular treatment of cranial dAVFs.

Validation of an 'endovascular-first' approach to spinal dural arteriovenous fistulas: an intention-to-treat analysis

BACKGROUND/OBJECTIVE

Spinal dural arteriovenous fistulas (SDAVFs) require pretreatment angiography; embolization can be performed in the same session. To validate this approach, obliteration and morbidity rates of 'endovascular-first' (embolization and microsurgery in the case of embolization failures) must be compared with rates for 'microsurgery-first' (microsurgical ligation without attempted embolization) approaches.

METHODS

We reviewed our institutional database (January 1998-October 2015) for SDAVFs, performing an intention-to-treat analysis comparing endovascular-first and microsurgery-first approaches.

RESULTS

A total of 71 patients underwent surgical and/or endovascular treatment for SDAVFs. All SDAVFs were ultimately occluded. Of 35 patients under consideration for an endovascular-first approach, radicular artery anatomy or anterior spinal artery embolization risk precluded attempting embolization in seven cases (20%). Among 28 patients undergoing embolization, angiographic non-opacification of the fistula was noted in 18 (64%). Fourteen patients had obliteration with excellent casting of the draining vein (50%) and did not undergo surgery. There were no significant differences in total complications (9% vs 11%; p=1.0) or permanent complications (3% vs 4%; p=1.0) after attempted endovascular and surgical treatment. Based on an intention-to-treat analysis, there were no significant differences in total complications (11% vs 14%; p=1.0), permanent complications (6% vs 3%; p=0.61), or the symptomatic resolution/improvement rate (80% vs 78%; p=1.0) between endovascular-first and microsurgery-first groups.

CONCLUSIONS

Our results support attempted embolization of SDAVFs prior to consideration of microsurgery, allowing for a less invasive treatment option in the same session as diagnostic angiography.

Spinal juvenile (Type III) extradural-intradural arteriovenous malformations

Object

Owing to their rarity, demographics, natural history, and treatment, results for spinal juvenile (Type III) extradural-intradural arteriovenous malformations (AVMs) are frequently only provided in case report format.

Methods

A pooled analysis was performed utilizing the PubMed database through April 2013. Individualized patient data were extracted to elucidate demographics, hemorrhage risk, and treatment result information.

Results

Twenty-nine studies describing 51 patients were included. The mean age at presentation was 15.0 ± 10.5 years with a slight male predilection (63%, 1.7:1 sex ratio). Presentation modality included progressive deficits in 35%, hemorrhage in 31%, acute deficits not attributed to hemorrhage in 22%, and asymptomatic/incidental in 12% of patients. The annual hemorrhage rate was 2.1%; statistically significant risk factors for hemorrhage included presentation age (HR 0.39 [95% CI 0.18–0.87]) and associated aneurysms (HR 8.74 [95% CI 1.76–43.31]). Seventy-seven percent of patients underwent treatment; after a mean follow-up of 2.6 ± 3.2 years, 73% were improved, 10% were the same, and 17% were worse neurologically. Of 25 cases with described angiographic results, 8 lesions were obliterated (32%). Of these 25 patients, 8 had AVMs with associated aneurysms, and the aneurysm was obliterated in all 8 patients. Over the course of 57.9 patient-years of follow-up, including 55.3 patient-years for partially treated AVMs, no hemorrhages were described, reflecting a trend toward protection from hemorrhage after treatment (p = 0.12, likelihood ratio test).

Conclusions

Spinal juvenile (Type III) extradural-intradural AVMs commonly present symptomatically. Associated arterial aneurysms increase their hemorrhage risk, and protection from hemorrhage may be achieved from partial obliteration of these lesions, particularly if targeted toward associated aneurysms.

Thoraco-lumbar artery aneurysms associated with a metameric paraspinal lesion presenting with retroperitoneal hemorrhage: Endovascular management

Background:

Retroperitoneal hemorrhage is a life-threatening condition. This is the first reported case of rupture of one of multiple thoraco-lumbar artery aneurysms associated with a metameric paraspinal vascular lesion.

Case Description:

A 77-year-old female patient presented to the emergency room with a new onset of left-sided low back pain shooting down the leg associated with weakness, numbness, and inability to walk. On physical examination, there was a notable left paraspinal swelling with a harsh bruit audible in the same area, left flank ecchymosis and a positive straight leg raising test. A computed tomography (CT) scan showed a large retroperitoneal hematoma. Digital subtraction angiography showed a large left paraspinal high-flow arteriovenous lesion, with large arterial aneurysms of the left T11, T12, and L1 segmental arteries. The patient was successfully treated with endovascular aneurysm embolization using coils and Onyx-34. Six months following the procedure, the patient had fully recovered, and a follow-up angiogram showed no residual or recurrent aneurysms.

Conclusion:

Thoraco-lumbar artery aneurysms have never previously been described in association with a metameric paraspinal vascular malformation. We report a case of retroperitoneal hemorrhage due to rupture of one of several high-flow artery aneurysms of a paraspinal arteriovenous malformation (AVM). The diagnosis was made on CTA, MRI, and angiography, and the lesion was successfully treated by transarterial embolization.

Modified classification of spinal cord vascular lesions

The literature on spinal vascular malformations contains a great deal of confusing terminology. Some of the nomenclature is inconsistent with the lesions described. Based on the experience of the senior author (R.F.S.) in the treatment of more than 130 spinal cord vascular lesions and based on a thorough review of the relevant literature, the authors propose a modified classification system for spinal cord vascular lesions. Lesions are divided into three primary or broad categories: neoplasms, aneurysms, and arteriovenous lesions. Neoplastic vascular lesions include hemangioblastomas and cavernous malformations, both of which occur sporadically and familially. The second category consists of spinal aneurysms, which are rare. The third category, spinal cord arteriovenous lesions, is divided into arteriovenous fistulas and arteriovenous malformations (AVMs). Arteriovenous fistulas are subdivided into those that are extradural and those that are intradural, with intradural lesions categorized as either dorsal or ventral. Arteriovenous malformations are subdivided into extradural-intradural and intradural malformations. Intradural lesions are further divided into intramedullary, intramedullary-extramedullary, and conus medullaris, a new category of AVM. This modified classification system for vascular lesions of the spinal cord, based on pathophysiology, neuroimaging features, intraoperative observations, and neuroanatomy, offers several advantages. First, it includes all surgical vascular lesions that affect the spinal cord. Second, it guides treatment by classifying lesions based on location and pathophysiology. Finally, it eliminates the confusion produced by the multitude of unrelated nomenclatural terms found in the literature.

Long-term pathological follow-up of cerebral arteriovenous malformations treated by embolization with bucrylate

We examined 17 intracranial arteriovenous malformations that were resected after treatment by embolization using bucrylate (isobutyl-2-cyanoacrylate). In nine specimens removed 5 days to 16 months after embolization therapy, a series of pathologic changes was seen, including patchy mural angionecrosis (adjacent to bucrylate fragments) up to six weeks after embolization, the presence of bucrylate in vessel walls and fibromuscular intimal cushions, and the occurrence (after several months) of entirely extravascular bucrylate. Occasional parts of recanalized vascular malformations were identified. Bucrylate was present within arteriovenous malformations as late as 16 months after embolization, although the amount appeared to be diminished. These findings suggest a specific sequence of events in the interaction between bucrylate and mural components within the malformations and may explain some important complications of embolization therapy (e.g., delayed hemorrhage after embolization).

The histotoxicity of cyanoacrylates. A selective review

Cyanoacrylates, a group of rapidly polymerizing adhesives, have found widespread uses in oral and general surgery as well as surgical subspecialties, for example as hemostatic and anastomotic agents. They have been utilized most recently as materials for embolotherapy of complex cerebral and extra-cerebral vascular anomalies. The histopathology that results from their deposition in human tissues is thus an important consideration, and the subject of this review. Particular attention is given to the fate of cyanoacrylates in cerebral lesions after iatrogenic embolization procedures. The apparent toxicity of these plastics on blood vessel walls is discussed in relation to experimental observations. It is imperative that clinicians who use this group of substances evaluate their potential functions in the light of the pathologic findings.

Therapeutic arterial embolisation: report of five years' experience

Therapeutic arterial embolisation was performed in 48 patients. Gelfoam, Oxycel, Bucrylate, Gianturco wire coils and lyophilised dura mater were used. Indications included control of acute haemorrhage, pre-operative vascular reduction, palliation of inoperable lesions, or to render such lesions operable, and elective definitive treatment. The technique was not considered to be of significant value as a pre-operative measure but was successful for the control of haemorrhage, the management of inoperable lesions and as an elective definitive treatment for various unusual lesions. One patient died and three had complications. The choice of occlusive material is discussed and depends upon the nature and vascularity of the lesion and whether short- or long-term occlusion is required.

Bleeding from esophageal varices exacerbated by splenic arterial-venous fistula: complete transcatheter obliterative therapy

A cirrhotic patient who had previously undergone both mesocaval shunting and transthoracic esophageal and gastric devascularization with splenectomy (Sugiura procedure) presented with recurring intractable variceal hemorrhage. Diagnostic visceral angiography demonstrated a large splenic arterial-venous fistula and gastroesophageal varices. Transarterial occlusion of the fistula and transheptic obliteration of the varices successfully done at one sitting prevented further bleeding. Follow-up angiography nine months later revealed persistent occlusion of the previous fistula and no evidence of esophageal varices.

Cyanoacrylate occlusion of a spinal cord arteriovenous malformation. Case report

✓ An arteriovenous malformation of the spinal cord was successfully obliterated by a percutaneous transcatheter technique using isobutyl 2-cyanoacrylate.