Microsurgical Obliteration of Craniocervical Junction Dural Arteriovenous Fistulas: Multicenter Experience

Clinical Characteristics and Management Considerations of Craniocervical Junction Arteriovenous Fistulas With Subarachnoid Hemorrhage: A Multicenter Study

BACKGROUND AND OBJECTIVES

Craniocervical junction (CCJ) arteriovenous fistulas (AVFs) presenting with subarachnoid hemorrhage (SAH) are rare conditions, with the optimal timing and approach to treatment still debated among neurosurgeons. The aim of this study was to characterize CCJ AVF-related SAH and determine appropriate surgical timing in a multicenter study.

METHODS

Data from 111 consecutive patients with CCJ AVF, including 51 with SAH, were collected from 29 centers across Japan. The vascular anatomy, diagnosis, treatment, surgical timing, and clinical outcomes were analyzed. Binary logistic regression was used to identify risk factors for complications.

RESULTS

The mean age of the patients was 67 years (range, 33-85 years), with 36 male patients and 15 female patients. Notably, a high percentage of patients (84%) presented with mild SAH (World Federation of Neurosurgical Societies grade I or II). Rebleeding and symptomatic vasospasm each occurred in 2% of cases. Initial treatments included direct surgery (n = 38), endovascular treatment (n = 10), and combined therapy (n = 3). Of the 51 patients, 17.6% (9/51) underwent acute (within 3 days of onset), 17.6% (9/51) subacute (within 4-14 days), and 64.7% (33/51) delayed procedures (after 15 days). Our study revealed a higher rate of complications, especially ischemic complications (P = .028), in patients who underwent acute surgery than in those who underwent delayed procedures. Endovascular treatment required retreatment in 60% (6/10) of cases, whereas direct surgery did not necessitate retreatment. The final modified Rankin Scale scores did not differ based on surgical timing.

CONCLUSION

CCJ AVF-related SAH is often mild, as evidenced by a high proportion of patients with low-grade World Federation of Neurosurgical Societies scores and a low rate of rebleeding/vasospasm. In contrast to intracranial aneurysmal SAH, our results do not support acute surgical intervention as the preferred management for patients with CCJ AVF-related SAH. Through delayed surgery, clinicians can avoid ischemic complications and improve patient outcomes.

Comparative outcomes of endovascular vs. surgical treatment in craniocervical junction dural arteriovenous fistulas: A systematic review and meta-analysis

BACKGROUND

Craniocervical junction dural arteriovenous fistulas (CCJ-DAVFs) are rare and complex vascular malformations that are challenging to diagnose and treat. This study aims to compare surgical and endovascular treatments for CCJ-DAVFs through a systematic review and meta-analysis.

METHODS

A systematic review and meta-analysis was conducted according to the PRISMA guidelines. PubMed, Scopus, and Web of Science databases were searched from inception to July 2024.

RESULTS

Fifteen studies involving 266 patients were included. Of these, 143 (53.8 %) patients underwent surgical treatment alone and 123 (46.2 %) underwent endovascular treatment alone. In the surgical group, the complete obliteration rate at last follow-up was 89.8 %. Retreatment rate was 6.2 %. Periprocedural complications occurred in 21.6 % of cases. In the endovascular group, the complete occlusion rate at last follow-up was 73.6 %. Retreatment rate was 46.7 %. Periprocedural complications occurred in 18.8 % of cases. Comparative meta-analysis revealed that the rate of complete obliteration at last follow-up was significantly higher in the surgical group (OR: 0.24; CI: 0.07 to 0.89, p = 0.03). Surgical treatment had a significantly higher successful treatment rate (OR: 0.24; CI: 0.07 to 0.89, p = 0.03) and lower retreatment rate (OR: 37.13; CI: 6.31 to 218.59, p < 0.01). No significant differences were observed between the groups in terms of periprocedural complications or complete resolution of symptoms.

CONCLUSION

Surgical treatment for CCJ-DAVFs achieves higher rates of complete obliteration with lower retreatment rates compared to endovascular treatment. However, endovascular treatment showed a tendency towards reducing periprocedural complications while increasing the likelihood of complete resolution of symptoms. Individualized treatment plans for CCJ-DAVFs, should be considered according to their anatomical location and potential surgical accessibility. Further studies are required to confirm these findings.

How I do it? surgical resection of craniocervical junction dural arteriovenous fistula

BACKGROUND

Craniocervical junction (CCJ) dural arteriovenous fistulas (DAVFs) represent a rare yet critical vascular anomaly that may result in significant neurological impairments.

METHOD

We report the case of a 52-year-old male with a history of medullary hemorrhage who underwent surgical intervention for a left CCJ DAVF. Through comprehensive surgical planning and meticulous intraoperative monitoring, multiple feeders of the DAVF were safely coagulated and transected, with successful DAVF obliteration confirmed by intraoperative angiography.

CONCLUSION

The patient demonstrated full recovery, underscoring the efficacy of surgical management in complex cases facilitated by advanced techniques in a hybrid operating theatre.

Dural arteriovenous fistulas at the craniocervical junction: a systematic review and meta-analysis

BACKGROUND

The management for craniocervical junction dural arteriovenous fistulas (CCJ-DAVFs) remains controversial and clinically challenging. We systemically summarized the clinical and angiographic outcomes of microsurgery, embolization, and conservative management.

METHODS

Relevant articles were retrieved from PubMed, Scopus, Web of Science, and Cochrane, following PRISMA guidelines. A systematic review and meta-analysis were conducted on the clinical characteristics, management approaches, and clinical and angiographic outcomes.

RESULTS

We included 13 articles (166 patients). The weighted mean age was 58.9 years (95%CI: 53.2-64.5), 58.8 years (95%CI: 48.4-69.2), and 63.8 years (95%CI: 60.1-67.5), in microsurgery, embolization, and conservative groups respectively, with an overall male sex predominance (microsurgery [n = 51/77, 66.2%], embolization [n = 44/56, 78.6%], and conservative management [n = 6/8, 75.0%]). Patients were managed with microsurgery (n = 80/172, 46.5%), embolization (n = 79/172, 45.9%), and conservative treatment (n = 13/172, 7.6%). Foramen magnum was the most common location (microsurgery [n = 34/77, 44.2%], embolization [n = 31/56, 55.4%], and conservative treatment [n = 3/8, 37.5%]). Vertebral artery was the primary feeder (microsurgery [n = 58/84, 69.1%], embolization [n = 41/86, 47.6%], and conservative treatment [n = 4/7, 57.1%]). Complete fistula obliteration rates were 74.1% (95%CI:52.3-88.2%) in the microsurgery group and 54.9% (95%CI:30.7-77.0%) in the embolization group. Complications rates were 16.2% (95%CI:6.7-34.5%) in the embolization group, 11.6% (95%CI:3.8-30.4%) in the microsurgery group, and 7.7% (95%CI:1.1-39.1%) in the conservative group. Different rates of good clinical outcomes were observed [microsurgery: 66.4% (95%CI:48.1-80.8%), embolization: 51.9% (95%CI:30.8-72.4%), and conservative: 11.6% (95%CI:4.4-27.4%)].

CONCLUSIONS

In patients with CCJ-DAVFs, each management approach has its own merits based on the fistula and patient characteristics.

The role of surgical disconnection for posterior fossa pial arteriovenous fistulas and dural fistulas with pial supply: an illustrative case series

BACKGROUND

Pial arteriovenous fistulas (pAVFs) are rare vascular malformations characterized by high-flow arteriovenous shunting involving a cortical arterial supply directly connecting to venous drainage without an intermediate nidus. Dural arteriovenous fistulas (dAVFs) can infrequently involve additional pial feeders which can introduce higher flow shunting and increase the associated treatment risk. In the posterior fossa, arteriovenous fistula (AVF) angioarchitecture tends to be particularly complex, involving either multiple arterial feeders-sometimes from both dural and pial origins-or small caliber vessels that are difficult to catheterize and tend to be intimately involved with functionally critical brainstem or upper cervical cord structures. Given their rarity, published experience on microsurgical or endovascular treatment strategies for posterior fossa pAVFs and dAVFs with pial supply remains limited.

METHODS

Retrospective chart review from 2019-2023 at a high-volume center identified six adult patients with posterior fossa pAVFs that were unable to be fully treated endovascularly and required microsurgical disconnection. These cases are individually presented with a technical emphasis and supported by comprehensive angiographic and intraoperative images.

RESULTS

One vermian (Case 1), three cerebellopontine angle (Cases 2-4) and two craniovertebral junction (Cases 5-6) posterior fossa pAVFs or dAVFs with pial supply are presented. Three cases involved mixed dural and pial arterial supply (Cases 1, 4, and 6), and one case involved a concomitant microAVM (Case 2). Endovascular embolization was attempted in four cases (Cases 1-4): The small caliber and tortuosity of the main arterial feeder prevented catheterization in two cases (Cases 1 and 3). Partial embolization was achieved in Cases 2 and 4. In Cases 5 and 6, involvement of the lateral spinal artery or anterior spinal artery created a prohibitive risk for endovascular embolization, and surgical clip ligation was pursued as primary management. In all cases, microsurgical disconnection resulted in complete fistula obliteration without evidence of recurrence on follow-up imaging (mean follow-up 27.1 months). Two patients experienced persistent post-treatment sensory deficits without significant functional limitation.

CONCLUSIONS

This illustrative case series highlights the technical difficulties and anatomical limitations of endovascular management for posterior fossa pAVFs and dAVFs with pial supply and emphasizes the relative safety and utility of microsurgical disconnection in this context. A combined approach involving partial preoperative embolization-when the angioarchitecture is permissive-can potentially decrease surgical morbidity. Larger studies are warranted to better define the role for multimodal intervention and to assess associated long-term AVF obliteration rates in the setting of pial arterial involvement.

Enhanced Treatment Options for Dural Arteriovenous Fistulas at the Craniocervical Junction: Endovascular Embolization Versus Microsurgery? A Single-Center 23-Year Experience

OBJECTIVE

The occurrence of dural arteriovenous fistulas (DAVFs) at the craniocervical junction (CCJ) is an uncommon vascular malformation. The diagnosis and treatment of CCJ DAVFs present a formidable challenge. This study aims to investigate the effect of endovascular embolization and microsurgery on improving patient prognosis.

METHODS

This retrospective study included patients diagnosed with CCJ DAVFs who received treatment at the First Affiliated Hospital of Fujian Medical University between January 2000 and January 2023. The clinical records, imaging data, and treatment methods were obtained from the hospital's medical record system. The patients were classified into microsurgery and embolization groups based on the surgical technique employed for treatment. The primary outcome measures were surgical-associated neurological dysfunction (SAND) and long-term neurological outcomes. The Cox proportional hazard regression was utilized to determine hazard ratios and 95% confidence intervals (CI) to assess the relationship between treatment methods and prognosis. Kaplan-Meier survival analysis was employed to evaluate the incidence of SAND in both cohorts.

RESULTS

This study recruited 46 patients with an average age of 53.72 ± 13.83 years. In the microsurgery group, there were 12 cases (26.1%) observed. While in the embolization group, there were 34 cases (73.9%). Of these patients, 16 (34.8%) experienced SAND after treatment. In the microsurgery group, there were 8 cases (75.0%), while in the embolization group, only 8 cases (23.5%) were reported. Specifically, the embolization group exhibited a significantly lower risk of SAND [adjusted hazard ratio = 0.259, 95% CI = 0.096-0.700; P = 0.008)] compared to the microsurgery group. Additionally, the combined Borden grade 2-3 was found to be significantly associated with SAND (adjusted hazard ratio = 3.150, 95% CI = 1.132-8.766; P = 0.028). The results of the Kaplan-Meier survival analysis indicated a statistically significant difference in the occurrence of favorable functional outcomes between the 2 groups (log-rank P = 0.0081).

CONCLUSIONS

CCJ DAVFs are uncommon disorders characterized by a diverse range of clinical manifestations. The functional prognosis of endovascular treatment may be superior to microsurgery.

Bridging veins at the craniocervical junction: from anatomy to clinical significance in dural arteriovenous shunts

PURPOSE

Bridging veins (BVs) serve as a route of pial venous reflux, and its anatomy is essential to understand the pathophysiology of dural arteriovenous shunts (dAVSs) around the craniocervical junction (CCJ) (from the jugular foramen level to the atlantal level). However, the anatomical variations of the BVs and their proximal connections remained poorly elucidated. This study aimed to radiologically investigate the anatomy of the bridging veins around CCJ and discuss the clinical significance of these BVs in the dAVS.

METHODS

We investigated normal venous anatomy of the BVs from the jugular foramen level to the atlantal level using preoperative computed tomography digital subtraction venography in patients undergoing elective neurosurgery. BVs affected by the dAVSs in the same region were also evaluated. The three types of dAVS, craniocervical junction, anterior condylar, and proximal sigmoid sinus, were investigated.

RESULTS

We identified six BV groups: superolateral, anterolateral, lateral, posterior, inferolateral, and inferoposterior. The superolateral and inferolateral groups, connected with the proximal sigmoid sinus and suboccipital cavernous sinus, respectively, were the largest groups. Each group has a specific downstream venous connection. The association with dVASs was observed only in the inferolateral group, which was typically the sole venous drainage in most dAVSs at the CCJ.

CONCLUSION

We reported detailed anatomy of BVs from the jugular level to the atlantal level, which enhanced our understanding of the pathophysiology of dAVSs in the corresponding region.

Craniocervivcal Spinal Dural Arteriovenous Fistula Ligation via a Modified Suboccipital Craniectomy and C1 Laminectomy: Operative Video

Dural arteriovenous fistulas (dAVFs) are vascular malformations of the central nervous system that feature an arteriovenous shunt fed by dural arteries and can be intracranial or spinal.1-3 Spinal dAVFs are classically found at the nerve root sleeve.3 The arterial supply can often be predicted by the fistula location, whereas the symptomatology and risk of hemorrhage is determined by the venous drainage pattern.1-3 Craniocervical fistulas, a subset of dAVFs, may arise in association with the anterior condylar venous confluence or more dorsally in association with the transdural segment of the vertebral artery.1-3 This latter type of fistula typically has spinal venous drainage and may present with myelopathy from spinal cord venous congestion. We present a 61-year-old man who presented with a 2-week history of neck pain and paraparesis. Magnetic resonance imaging of the cervical spine revealed diffuse T2 hyperintensity of the cord from the pons to the level of the T1 vertebra. A computed tomography angiogram showed a possible dAVF at the craniocervical junction on the left. Because of the unclear nature of the patient's spinal cord lesion, a cerebral angiogram was performed. It confirmed a dAVF associated with the transdural segment of the left vertebral artery, with small dural feeders from the left vertebral artery and venous drainage into the anterior spinal vein. The patient underwent a modified suboccipital craniectomy and C1 laminectomy for dAVF ligation (Video 1). He was extubated postoperatively and discharged to a rehabilitation unit with improvement in lower extremity strength.

Treatment of high cervical arteriovenous fistulas in the craniocervical junction region

The craniocervical junction (CCJ) is a complex region. Rarely, arteriovenous fistulas (AVFs) can occur in the CCJ region. Currently, it is accepted that CCJ AVFs should only refer to AVFs at the C1-C2 levels. It is reasonable to assume that high cervical CCJ AVFs are being referred to when discussing CCJ AVFs. High cervical CCJ AVFs can be divided into the following four types: dural AVF, radicular AVF, epidural AVF and perimedullary AVF. Until now, it was difficult to understand high cervical CCJ AVFs and provide a proper treatment for them. Therefore, an updated review of high cervical CCJ AVFs is necessary. In this review, the following issues are discussed: the definition of high cervical CCJ AVFs, vessel anatomy of the CCJ region, angioarchitecture of high cervical CCJ AVFs, treatment options, prognoses and complications. Based on the review and our experience, we found that the four types of high cervical CCJ AVFs share similar clinical and imaging characteristics. Patients may present with intracranial hemorrhage or congestive myelopathy. Treatment, including open surgery and endovascular treatment (EVT), can be used for symptomatic AVFs. Most high cervical CCJ AVFs can be effectively treated with open surgery. EVT remains challenging due to a high rate of incomplete obliteration and complications, and it can only be performed in superselective AVFs with simple angioarchitecture. Appropriate treatment can lead to a good prognosis.

Angioarchitectural features of arteriovenous fistulas at craniocervical junction predicting clinical presentation and unfavorable neurological function: insight from a multicenter cohort and pooled analysis

Arteriovenous fistulas (AVFs) at the craniocervical junction (CCJ) are uncommon conditions with complex angioarchitecture. The objective of this study was to identify the angioarchitectural features of CCJ-AVF that were predictive of clinical presentation and neurological function. The study encompassed a total of 68 consecutive patients with CCJ-AVF at two neurosurgical centers between 2014 and 2022. Additionally, a systematic review was conducted, including 68 cases with detailed clinical data obtained via PubMed database spanning 1990 to 2022. Clinical and imaging data were collected and pooled together to analyze factors associated with subarachnoid hemorrhage (SAH), myelopathy, and modified Rankin scale (mRS) at presentation. The mean age of the patients was 54.5 ± 13.1 years, with 76.5% of them being male. The most common feeding arteries were V3-medial branches (33.1%), and drainage was frequently through the anterior or posterior spinal vein/perimedullary vein (72.8%). SAH was the most common presentation (49.3%), and an associated aneurysm was identified as a risk factor for SAH (adjusted OR, 7.44; 95%CI, 2.89-19.15). Anterior or posterior spinal vein/perimedullary vein (adjusted OR, 2.78; 95%CI, 1.00-7.72) and male gender (adjusted OR, 3.76; 95%CI, 1.23-11.53) were associated with higher risk for myelopathy. Myelopathy at presentation was an independent risk factor for unfavorable neurological status (adjusted OR per score, 4.73; 95%CI, 1.31-17.12) in untreated CCJ-AVF. The present study identifies risk factors associated with SAH, myelopathy, and unfavorable neurological status at presentation in patients with CCJ-AVF. These findings may help treatment decisions for these complex vascular malformations.