Microsurgical neurovascular anastomosis: The example of superficial temporal artery to middle cerebral artery bypass. Technical principles

Analyzing characteristics of collateral flow to parasylvian cortical arteries by three-dimensional digital subtraction angiography-magnetic resonance angiography fusion imaging in adult moyamoya disease

Objective

The hemodynamic sources of recipient parasylvian cortical arteries (PSCAs) were significantly related to postoperative cerebral hyperperfusion (CHP) after bypass surgery in patients with moyamoya disease (MMD). The present study aimed to introduce a new method to investigate the characteristics of PSCAs hemodynamic sources and their relationships with clinical presentations in adult MMD and to provide preoperative evaluation for recipient vessel selection in MMD bypass surgery.

Methods

The hemodynamic sources of the PSCAs in 171 symptomatic MMD hemispheres were analyzed by three-dimensional digital subtraction angiography (3D-DSA) combined with magnetic resonance angiography (MRA) fusion imaging. The spatial and temporal characteristics of the hemodynamic sources of the PSCAs and their associations with the patient's demographics, Suzuki stage, and initial onset type were investigated.

Results

Six major types of hemodynamic sources in the PSCAs were observed. There was a significant difference between the hemodynamic sources of the PSCAs above and below the SF (P < 0.001). With advancing Suzuki stages, collateral flow to the PSCAs above the SF from the internal carotid arteries (ICAs) significantly decreased, while the non-ICAs increased (P < 0.001). Multivariate analysis revealed that hemodynamic sources of the PSCAs above the SF were significantly associated with patients' initial onset type (P = 0.026).

Conclusion

In MMD hemispheres, the hemodynamic sources of the PSCAs above the SF are more varied than those below the SF and present a typical conversion trend from ICAs to non-ICAs with advancing Suzuki stages. Analyzing the hemodynamic sources of the PSCAs can help in understanding the conversion pattern of compensatory vascular systems, predicting episodes in MMD, and preoperatively evaluating suitable recipient vessel selection for bypass surgery to avoid postoperative CHP.

Moyamoya disease with distal anterior choroidal artery aneurysm resected via transcallosal approach: A case report and review

RATIONALE

Moyamoya disease (MMD) is a cerebrovascular structural disorder characterized by bilateral stenosis and obstruction of the internal carotid artery, anterior cerebral artery, and initial segment of a middle cerebral artery, as well as the aberrant formation of collateral arteries at the base of the brain. Moyamoya disease with distal anterior choroidal artery (AChA) aneurysm is extremely uncommon. At present, the treatment of Moyamoya disease with aneurysm mainly includes conservative treatment and surgical treatment, including revascularization, endovascular therapy and microsurgical clipping or resection. Interventional therapy is the first treatment of choice. For those whose paths are tortuous and inaccessible and intervention fails, I successfully excised them through craniotomy.

PATIENT CONCERNS

The 38-year-old male patient, diagnosed with Moyamoya disease 11 years ago and was hospitalized for multiple intraventricular hemorrhages throughout that time. During the 11 years, the patient was hospitalized for intra ventricular hemorrhage for several times. The patient was diagnosed as moyamoya disease for many times by digital subtraction angiography, but he was recommended to come to our hospital for cerebrovascular bypass surgery 3 months after each hemorrhage, but he did not come to our hospital until the next intraventricular hemorrhages.

DIAGNOSES

This recurrent intraventricular bleeding was suspected to be caused by MMD, and a digital subtraction angiography of the brain revealed an aneurysm of the distal AChA.

INTERVENTIONS

Interventional therapy was the first choice. During the operation, transcatheter aneurysm embolization was tried. Finally, interventional therapy was abandoned because the vessels were too thin and tortuous and the guide wire could not pass through. After detecting the aneurysm using computerized tomography angiography, the distal AChA aneurysm was resected through the lateral interventricular foramen of the corpus callosum, and the corpus callosum was parted along the interhemispheric fissure to access the third ventricle.

OUTCOMES

On the 21st postoperative day, the patient improved, recovered to a Glasgow Coma Scale score of 15.

LESSONS

We conclude that craniotomy is a satisfying alternative in patients with MMD complicated by perforated distal AChA aneurysm hemorrhage if the vascular prerequisites for endovascular treatment are not accessible and the patient has a favorable prognosis.

The Jai knot technique for deep microvascular surgery

BACKGROUND

Microvascular surgery requires fine finger movements with stabilised hands for successful anastomosis. Limited space in deeper locations, such as the interhemispheric fissure, increases the difficulty in placing the knots during microvascular suturing.

METHODS

This note describes a novel technique of constructing reef knots. The technique reduces the excursions of the instrument tips while knotting.

CONCLUSIONS

Using this knotting technique in deep microvascular suturing improves the ergonomic ease and stability of knots, while working in deep locations through narrow corridors.

Detethering the superficial temporal artery: Application to tension free superficial temporal artery-middle cerebral artery bypasses

Extracranial-intracranial bypass has been shown to be effective in the surgical treatment of moyamoya disease, complex aneurysms, and tumors that involve proximal vasculature in carefully selected patients. Branches of the superficial temporal artery (STA) are used commonly for the bypass surgery; however, an appropriate length of the donor vessel must be harvested to avoid failure secondary to anastomotic tension. The goal of this cadaveric study was to investigate quantitatively operative techniques that can increase the STA length available to facilitate tension-free STA-middle cerebral artery (MCA) bypass. We conducted a cadaveric study using a total of 16 sides in eight cadavers. Measurements of the STA trunk with its frontal branch (STAfb) were taken before and after skeletonization and detethering of the STA with the STAfb and mobilization of the parietal branch of the STA. A final measurement of the STA with the STAfb was taken for the free length gained toward visible proximal cortical branches of the MCA. Paired student's t-tests were used to compare the mean length before and after mobilization and unpaired t-tests to analyze according to laterality. The mean length of the STA with the STAfb was 9.0 cm prior to modification. After skeletonization and mobilization, the mean lengths increased significantly to 10.5 and 11.3 cm, respectively (p < 0.05). Especially in the cases that had the coiled and tortuous STA, skeletonization was considerably effective to increase the length of the STA with the STAfb. After simulating a bypass by bringing the STAfb to the recipient MCA site, the mean extended length of the STA with the STAfb was 3.0 cm. There were no statistically significant differences between sides in all measurements. We report a significant increase in the mean STA length available (3.0 cm) following skeletonization and mobilization. Clinical applications of the extended length of the STA with the STAfb may facilitate tension-free STA-MCA bypasses and improve outcomes. Further studies are needed in a clinical context.

Continuous Interrupted Double Throw Suturing Method: A Novel Suturing Technique for Extracranial-Intracranial Bypass

OBJECTIVE

Despite failure of the EC/IC Bypass Study Group to demonstrate effectiveness in minimizing future stroke events, superior temporal artery-medial cerebral artery (STA-MCA) bypass remains an essential treatment for complex giant intracranial aneurysms, tumors, moyamoya disease with ischemia, and atherosclerotic steno-occlusive disease with hemodynamic cerebrovascular insufficiency. The objective of this report is to describe a novel suturing technique for STA-MCA bypass that helps reduce donor-recipient anastomosis time, allowing for a well-organized systematic workflow.

METHODS

Step 1 involves passing the needle of a 9-0 polypropylene suture from out-to-in on the donor vessel followed by in-to-out on the recipient vessel. Step 2: Before cutting and tying a knot as per the established method of suturing, repeat step 1 and leave the needle "parked", creating a loop that is then cut at its proximal end. Step 3: Tie knots using the jeweler's forceps. Repeat previous steps until there are enough throws to seal the bypass adequately.

RESULTS

The STA-MCA bypass serves as a principal method for flow augmentation. The technique described here allows for more efficient and organized microsurgical movements reducing vessel tissue manipulation and clamp time.

CONCLUSIONS

We describe a novel technique for interrupted STA-MCA bypass suturing that adds efficiency, safety, organization, and operative ease compared with the conventional method of interrupted vessel suturing.

EC-IC Bypass; Our Experience of Cerebral Revascularization with Intraoperative Dual-Image Video Angiography (Diva)

Background:

Extracranial-intracranial (EC-IC) arterial bypass has been used in the treatment of various cerebrovascular ischemic disease due to atherosclerosis or Moyamoya disease, skull base tumors encasing large IC artery or complex IC aneurysms.

Aim:

The aim is to analyze surgical technique (EC-IC bypass) and its outcome with intraoperative use of dual image video angiography (DIVA) and Doppler ultrasound.

Materials and Methods:

We studied in this article a series of 23 patients operated in Banbuntane Hotokukai Hospital, Fujita Health University, for which a superficial temporal artery-middle cerebral artery anastomosis was done for steno-occlusive disease, giant IC aneurysm or Moyamoya disease. The study was conducted between 2018 and 2020. We used dual-image video angiography (DIVA) and Doppler ultrasound to assess the luminal patency of anastomosis during the procedure.

Results:

In this study, three patients presented with Moyamoya disease, 4 had aneurysm, whereas 16 patients presented with the vascular steno-occlusive disease. The patients were divided into three categories (steno-occlusive disease, Moyamoya, and flow replacement for giant aneurysm). Dual image video angiography, along with intraoperative Doppler, helped us in the assessment of luminal patency of the anastomosis.

Conclusion:

Hemodynamic recovery after cerebrovascular bypass brings about a better outcome in ischemic stroke. The result of surgery improves with proper selection of patients with hemodynamic impairment (in Stage 2). With various modalities such as intraoperative Doppler, DIVA (Dual-image Video Angiography) and improved surgical techniques may aid in the reduction of complications and improve clinical outcome.

Postoperative hemorrhage during the acute phase after direct or combined revascularization for moyamoya disease: risk factors, prognosis, and literature review

OBJECTIVE

Postoperative hemorrhage during the acute phase is rarely observed after revascularization surgery for moyamoya disease (MMD) but can have severe complications. Its risk factors and outcomes are still unclear. The aim of this study was to investigate the predictors of postoperative hemorrhage during the acute phase in MMD and examine the outcomes of the hemorrhage.

METHODS

The authors reviewed the preoperative clinical characteristics and radiographic features of 465 consecutive MMD cases (518 procedures) that had undergone direct or combined bypass surgery at their institution between 2009 and 2015. Patients with postoperative intracerebral hemorrhage (ICH) or ICH plus intraventricular hemorrhage (IVH) during the acute phase were screened, and then the incidence, location, and risk factors of hemorrhage in these patients were analyzed. Short-term and long-term outcomes (modified Rankin Scale scores) for these patients were also collected. Outcomes were compared between patients with and those without postoperative ICH using propensity score analysis to reduce the between-group differences in baseline characteristics.

RESULTS

Postoperative hemorrhage occurred in 11 (2.1%; ICH = 9, IVH = 2) of 518 procedures (mean patient age 39.82 ± 8.8 years). Hemorrhage occurred in the first 24 hours after the operation in 8 cases (72.7%). In the ICH group, most of the hemorrhage sites (77.8%) were located beneath the anastomosed area, and the mean hematoma volume was 16.98 ± 22.45 ml (range 3-57 ml). One case from the ICH group required hematoma evacuation. Among the adult patients (463 procedures [89.4%]), preoperative hypertension (p = 0.008), CT perfusion (CTP) stage > III (p = 0.013), and posterior circulation involvement (p = 0.022) were significantly associated with postoperative ICH. No significant differences between the postoperative ICH group and the no-hemorrhage group were detected in terms of postoperative neurofunctional status at discharge (p = 0.569) or at the last follow-up (p = 1.000). Neither was there a significant difference in future stroke risk (p = 0.538) between these two groups.

CONCLUSIONS

Preoperative hypertension, CTP stage > III, and posterior circulation involvement are independent risk factors for postoperative ICH after direct or combined revascularization for MMD. After appropriate perioperative management, postoperative ICH has no significant correlations with the postoperative short-term and long-term neurofunctional status.

How I do it: superficial temporal artery-middle cerebral artery bypass for flow augmentation and replacement

BACKGROUND

The superficial temporal artery-middle cerebral artery (STA-MCA) bypass augments blood flow in patients with cerebral ischemia or replaces flow in patients with complex aneurysms or skull base tumors requiring vessel sacrifice.

METHOD

We provide a description of the STA-MCA bypass with figures and video to illustrate the procedure.

CONCLUSION

The STA-MCA end-to-side anastomosis is a foundational skill for the cerebrovascular surgeon and a building block for more complex bypasses.

Superficial Temporal Artery: Middle Cerebral Artery Bypass, Our Series of 20 Cases, Surgical Technique and Indications with Illustrative Cases

The first extracranial-intracranial (EC-IC) bypass surgery was performed by professor Yasargil in 1967 since then this procedure has been widely used in vascular neurosurgery and sometimes, in tumors excision when a vascular sacrifice is necessary. In this article, we will illustrate the surgical technique of the superficial temporal artery-middle cerebral artery (STA-MCA) bypass with two cases; a 59-year-old male and 64-year-old female who presented with an occlusion of the MCA. The male presented also with a posterior communicating artery-IC aneurysm which was clipped in the same sitting. We also studied in this paper a series of 20 patients operated in Banbuntane Hotokukai Hospital, Fujita Health University, for which a low-flow STA-MCA anastomosis was done for steno-occlusive disease or moyamoya disease. In Banbuntane Hotokukai Hospital, Fujita Health University, 20 patients were operated since 2015, 12 patients were male. Five patients presented with moyamoya disease, while 15 patients presented with vascular steno-occlusive disease. The steno-occlusion was found in internal carotid artery in nine patients. The patients were divided into two categories (steno-occlusive disease and moyamoya). STA-MCA bypass is now one of the basic techniques to master in vascular neurosurgery. It requires to perform the anastomosis correctly within the permissible time. The goal is to have a long-term patency for the anastomosed vessel.

Clinical importance of the occipital artery in vascular lesions: A review of the literature

The occipital artery (OA) is a critical artery in vascular lesions. However, a comprehensive review of the importance of the OA is currently lacking. In this study, we used the PubMed database to perform a review of the literature on the OA to increase our understanding of its role in vascular lesions. We also provided our typical cases to illustrate the importance of the OA. The OA has several variations. For example, it may arise from the internal carotid artery or anastomose with the vertebral artery. Therefore, the OA may provide a crucial collateral vascular supply source and should be preserved in these cases. The OA is a good donor artery. Consequently, it is used in extra- to intracranial bypasses for moyamoya disease (MMD) or aneurysms. The OA can be involved in dural arteriovenous fistula (DAVF) and is a feasible artery for the embolisation of DAVF. True aneurysms and pseudoaneurysms can occur in the OA; surgical resection and embolisation are the effective treatment approaches. Direct high-flow AVF can occur in the OA; embolisation treatment is a good option in such cases. The OA can also be involved in MMD and brain arteriovenous malformation (AVM) by forming transdural collaterals. For a patient in the prone position, if occipital and suboccipital craniotomies are performed, the OA can also be used for intraoperative angiography. In brief, the OA is a very important artery in vascular lesions.

Effect of Adventitial Dissection of Superficial Temporal Artery on the Outcome of Superficial Temporal Artery-Middle Cerebral Artery Bypass in Moyamoya Disease

Superficial temporal artery-middle cerebral artery (STA-MCA) has been used for the treatment of occlusive cerebrovascular disease including moyamoya disease. The effect of STA-MCA bypass depends not only on the patency of anastomosis, but also on integrity and functional capacity of the donor artery. In the present prospective study, we investigated the effect of extensive stripping STA adventitia and fasciae on hemodynamic function in STA-MCA bypass of moyamoya disease patients. Twenty patients (n=8 in control group, n=12 in stripping group) of moyamoya disease were subjected to STA-MCA end-to-side direct anastomosis. Perfusion unit (PU) values of the cortex were measured and recorded using a Laser Doppler flowmetry (LDF) for 5 days. Computed tomography perfusion was performed to determine blood flow before and after bypass. No patient experienced significant neurologic deficits associated with neurosurgical complications. LDF demonstrated that adventitial stripping group had higher cerebral blood flow increase than control group. The adventitia stripping group tends to have higher rate of increased cerebral perfusion after bypass than non-stripping group. Furthermore, the ultrasound examination at 3 days after bypass demonstrated that the adventitial stripping group has a tendency of bigger STA and higher peak systolic velocity than control group. Our result suggests that stripping adventitia of STA improves hemodynamics of STA-MCA bypass in moyamoya disease.

Giant and complex aneurysms treatment with preservation of flow via bypass technique

Due to their anatomical characteristics and the complexity of the procedures required to obtain their complete occlusion, the treatment of giant intracranial aneurysms is a real challenge. Direct reconstructive strategies, whether by interventional neuroradiology (coils, stents) or microsurgical (clipping) means, are not always applicable and, in patients that would not tolerate parent or collateral artery sacrifice, the adjunction of a revascularization procedure using a bypass technique might be necessary. Cerebral arterial bypasses can be classified according to their function (3 types: flow replacement, flow reversal or protective), the branching mode of the graft used (3 types: pedicled, interpositional or in situ), the sites of anastomosis (2 types: extracranial-intracranial or intracranial-intracranial) and the class of flow they are supposed to provide (3 types: low-, intermediate- or high-flow). In this article, the authors review the different aspects in the management of patients with a giant intracranial aneurysm using a bypass: preoperative work-up, types of bypass and indications, surgical techniques and results.