EC-IC bypass for cavernous carotid aneurysms: An initial experience with twelve patients

Natural History of Cavernous Carotid Artery Aneurysms: A Systematic Review and Meta-Analysis

BACKGROUND

Cavernous carotid artery aneurysms (CCAAs) represent a common condition seen in clinical practice with significant practice variability. The aim of this systematic review and meta-analysis was to aggregate current evidence on the natural history of CCAAs.

METHODS

MEDLINE/PubMed, EMBASE, and Cochrane Library were queried from inception until December 2023. The primary outcome of this study was CCAA-related mortality. The secondary outcomes of this study were aneurysm growth, intracranial ischemic and hemorrhagic events, improved non-cerebrovascular symptoms, and new or worsened non-cerebrovascular symptoms during follow-up.

RESULTS

Ten studies met our inclusion criteria, involving 835 patients and 975 CCAAs. CCAA-related mortality had an incidence rate of 0.28 (95% CI 0.12-0.64) per 100 person-years (PYs) of follow-up. The incidence rate of CCAA growth was 2.91 (1.05-8.07) per 100 PYs of follow-up. The incidence rate of CCAA-related intracranial ischemic events was 0.4 (0.16-1.01) per 100 PYs of follow-up. The incidence rate of CCAA-related intracranial hemorrhagic events was 0.54 (0.33-0.87) per 100 PYs of follow-up. The incidence rate of improved non-cerebrovascular symptoms was 2.51 (1.18-5.33) per 100 PYs of follow-up. The incidence rate of new or worsened non-cerebrovascular symptoms was 3.41 (2.03-5.73) per 100 PYs of follow-up.

CONCLUSIONS

CCAAs are typically benign lesions with a low risk of rupture and life-threatening complications. CCAAs tend to follow an indolent course regarding non-cerebrovascular outcomes, and new or worsening symptoms are infrequent during the clinical course. However, spontaneous resolution of non-cerebrovascular symptoms and cranial nerve deficits at presentation is uncommon.

Is STA really a low‐flow graft? A quantitative ultrasonographic study of the flow of STA for cerebral revascularization in MMD patients

OBJECTIVE

Direct revascularization remains an important tool in the treatment of patients with Moyamoya disease (MMD). The superficial temporal artery (STA) is the most commonly used donor vessel for direct bypass, and an STA graft has traditionally been considered a low-flow graft for flow augmentation. This study aimed to quantitatively evaluate the blood flow of the STA after direct revascularization.

METHODS

All direct revascularization procedures performed between 2018 and 2021 by one experienced neurosurgeon were screened. Quantitative ultrasound was used to measure the flow data of the patient's bilateral parietal branch of the STA(STA-PB), the bilateral frontal branch of the STA(STA-FB), and the left radial artery. Data on the patients' basic information, Suzuki grade, Matsushima type, anastomosis type, and blood biochemical parameters were collected and analyzed using univariate and multivariate models. An MBC Scale scoring system was proposed to evaluate the recipient artery network of the middle cerebral artery (MCA) tree. The relationship between MBC Scale score and STA graft flow was statistically analyzed.

RESULTS

In total, 81 patients (43 males and 38 females) successfully underwent STA-MCA bypass and were included in this study. The mean flow rates in the STA-PB graft on 1 day preoperatively, 1 day postoperatively, 7 days postoperatively, and >6 months postoperatively (long-term) were 10.81, 116.74, 118.44, and 56.20 mL/min respectively. Intraoperative graft patency was confirmed in all patients. Comparing the preoperative and all postoperative time points, the STA-PB flow rates were statistically significant (p < 0.001). The MCA-C score was significantly associated with postoperative flow rate on day 1 (p = 0.007).

CONCLUSION

The STA is a useful donor artery for direct revascularization inpatients with MMD and can provide sufficient blood supply to the ischemic cerebral territory.

[Mathematical modeling of high-flow extra-intracranial bypass in the treatment of a complex cerebral aneurysm]

BACKGROUND

Intracranial aneurysms (IAs) pose a high risk of spontaneous subarachnoid hemorrhage. In the most complex cases, the only way to exclude the aneurysm from the circulation is to perform a high-flow extracranial-to-intracranial bypass, thus creating a new bloodstream. This avoids severe ischemic complications; however, it requires careful consideration of individual anatomy and hemodynamic parameters. Computational fluid dynamics (CFD) can be of great help in planning such a surgery by creating 3D patient-specific models of cerebral circulation.

OBJECTIVE

Assessment of the perspectivity of high-flow extracranial-to-intracranial bypass planning using computational modeling.

MATERIAL AND METHODS

In this research work, we have applied the CFD methods to a patient with a giant thrombosed IA of the internal carotid artery (ICA). Preoperative CTA images and Gamma Multivox workstation were used to create a 3D model with current geometry and three additional models: Normal anatomy (no IA), Occlusion (with ligated ICA), Virtual bypass (with bypass and ligated ICA). The postoperative data were also available. Boundary conditions were based on PC-MRI measurements. Calculation of hemodynamics was conducted with a finite element package ANSYS Workbench 19.

RESULTS

The results demonstrated an increase in the blood flow on the affected side by more than 70% after the virtual surgery and uniformity of flow distribution between the affected and contralateral sides, indicating that the treatment is likely to be efficient. Later, postoperative data confirmed that.

CONCLUSION

The study showed that virtual preoperative CFD modeling could significantly simplify and improve surgical planning.

High-Flow Bypass with Radial Artery Graft for Cavernous Carotid Aneurysms: A Case Series

Background:

The incidence of cavernous carotid aneurysms (CCAs) of intracranial aneurysms is low. Majority of cases presented as incidental findings with benign natural progression. The most common presenting symptoms are multiple cranial neuropathies among symptomatic patients. The treatment modalities for symptomatic patients include direct surgical clipping, endovascular coil embolization, or placement of flow diverter, or indirect procedures such as occlusion of parent artery with and without revascularization techniques. The advancement in the microsurgical treatments and endovascular devices have enable a high success rate in the treatment of patients with CCAs with low morbidity and mortality rates.

Objective:

To study the surgical outcomes of patients with cavernous aneurysm who underwent high-flow bypass between 2015 and 2020 in our institution.

Materials and Methods:

A total of six patients in a single institution presented with CCAs who were treated with high-flow bypass surgery were included in this case-series. A single-case illustration was presented focusing on the details of surgical case management of CCA. The intraoperative middle cerebral artery (MCA) pressure monitoring during bypass surgery was also described.

Results:

All five female patients and one male patient who were diagnosed with cavernous carotid aneurysms were studied. The mean age was 68.8 years old (range: 24-84 years old) and the mean size of the aneurysm was 19.6mm (range: 9.7 – 30mm). There were successfully treated with high flow bypasses using radial artery graft without any neurological sequelae.

Conclusion:

The surgical treatments of cavernous carotid aneurysms should be limited to experienced neurosurgeons in view of significant risk of morbidity and mortality. Endovascular procedures may be the main stay of treatments. The success shown in this case series with parent artery occlusion and bypass surgery may provide an safe alternative to the endovascular treatment.

Does Universal Bypass before Carotid Artery Occlusion Obviate the Need for Balloon Test Occlusion: Personal Experience with Extracranial-Intracranial Bypass in 23 Patients

Aim

Carotid artery ligation carries a potential risk of ischemic complications even in patients with good collaterals and adequate cross-circulation. Preoperative assessment through balloon test occlusion (BTO) is technically challenging and not feasible in all patients. We analyze our experience with universal bypass without performing detailed cerebrovascular reserve (CVR) studies in 23 patients before carotid artery ligation.

Patients and Methods

This was a retrospective analysis of the case records of 23 patients who underwent cervical carotid artery ligation for various indications since January 2009.

Results

The study included 21 patients with cavernous carotid aneurysms, one patient with a large fusiform petrous carotid aneurysm, and one patient with recurrent glomus jugulare encasing the cervical internal carotid artery. The initial 12 patients underwent preoperative BTO with hypotensive challenge. All patients underwent a bypass procedure followed by carotid artery ligation irrespective of the BTO findings. Patients who successfully completed a BTO underwent a low-flow superficial temporal artery to middle cerebral artery bypass. A high-flow extracranial-intracranial bypass using a saphenous vein graft from external carotid artery to middle cerebral artery was done in all patients who either failed the BTO or did not undergo BTO. We had two operative mortalities and one poor outcome. All the other patients had a good recovery with a Glasgow outcome score of 5 at the last follow-up. Graft patency rates were 81.1% in both the low-flow and high-flow groups.

Conclusion

Universal high-flow bypass is safe, effective, and should be preferred in all patients before carotid artery ligation. It obviates the need for detailed CVR assessment, especially in centers with limited resources.

Superior orbital fissure syndrome caused by an internal carotid artery aneurysm in the cavernous sinus

This article describes the case of superior orbital fissure syndrome caused by an internal carotid artery aneurysm in the cavernous sinus. Etiology, clinical presentations, and diagnostic methods are discussed. Possible regression of signs and symptoms after timely endovascular treatment of an internal carotid artery aneurysm in the cavernous sinus is reported.