Comparison Of The Treatment Strategies For Symptomatic Chronic Internal Carotid Artery Occlusion.

BACKGROUND: The best management of symptomatic chronic internal carotid artery occlusion (CICAO) has been controversial. This systematic review and meta-analysis were to compare the outcomes of different treatment strategies for symptomatic CICAO. METHODS: Two independent researchers conducted a search of articles on the treatment of CICAO published between January 2000 and October 2023 in PubMed, Web of Science, Embase, and The Cochrane Library. Twenty-two articles were eligible for meta-analysis using a random effects model to combine and analyze the data for the pooled rates of stroke and death, and the rates of procedural success and significant restenosis/occlusion. RESULTS: Total of 1193 patients from 22 publications were included in this study. 6 of them had bilateral internal carotid artery occlusion. The 30-day stroke and death rates were 1.1% (95%CI: 0%-4.4%) in the best medical treatment (BMT) group, 4.1% (95%CI: 0.7%-9.3%, I2=71.4%) in the extracranial-intracranial (EC-IC) bypass group, 4.4% (95%CI: 2.4% - 6.8%, I2 = 0%) in the carotid artery stenting (CAS) group, and 1.2% (95% CI: 0% - 3.4%, I2 = 0%) in the combined carotid endarterectomy and stenting (CEA+CAS) group. During follow-up of 16.5 (±16.3) months, the stroke and death rates were 19.5%, 1.2%, 6.6%, and 2.4% in BMT, EC-IC, CAS and CEA+CAS groups respectively. The surgical success rate was 99.7% (95%CI: 98.5%-100%, I2=0%) in EC-IC group, 70.1% (95%CI: 62.3%-77.5%, I2=64%) in CAS group, and 86.4% (95%CI: 78.8%-92.7%, I2=60%) in CEA+CAS group. The rate of post-procedural significant restenosis or occlusion was 3.6% in EC-IC group, 18.7% in CAS group, and 5.7% in CEA+CSA group. The surgical success rate was negatively associated by the length of internal carotid artery (ICA) occlusion. Surgical success rate was significantly higher in the patients with occlusive lesion within C1 to C4 segments, comparing to those with occlusion distal to C4 segment (OR:11.3, 95%CI: 5.0-25.53, P<0.001). A proximal stump of ICA is a favorable sign for CAS. The success rate of CAS was significantly higher in the patients with an ICA stump than that in the patients without (OR=11.36, 95%CI:4.84-26.64, P<0.01). However, the success rate of CEA+CAS was not affected by the proximal ICA stump. CONCLUSIONS: For the management of symptomatic CICAO, BMT alone is associated with the highest risk of mid- and long-term stroke and death. EC-IC bypass surgery and CEA+CAS should be considered as the choice of treatment based on operator's expertise and patient's anatomy. CAS may be employed as an alternative option in high surgical risk patients, especially when proximal ICA stump exists.

Maxillary Nerve as Landmark for Exposure of the Internal Maxillary Artery in Extracranial-Intracranial Bypass Surgery.

OBJECTIVE: To establish a new method for fast exposure of the internal maxillary artery (IMA) during extracranial-intracranial bypass surgery. METHODS: To explore the positional relationship between the IMA and the maxillary nerve and pterygomaxillary fissure, 11 formalin-fixed cadaveric specimens were dissected. Three bone windows of the middle fossa were created for further analysis. Then the IMA length that could be pulled up above the middle fossa was measured after different degrees of removal of bony structure. The IMA branches under each bone window were also explored in detail. RESULTS: The top of the pterygomaxillary fissure was located 11.50 mm anterolateral to the foramen rotundum. The IMA could be identified just inferior to the infratemporal segment maxillary nerve in all specimens. After drilling of the first bone window, the IMA length that could be pulled above the middle fossa bone was 6.85 mm. After drilling of the second bone window and further mobilization, the IMA length that could be harvested was significantly longer (9.04 mm vs. 6.85 mm; P < 0.001). Removal of the third bone window did not significantly improve the IMA length that could be harvested. CONCLUSIONS: The maxillary nerve could be used as a reliable landmark for the exposure of the IMA in the pterygopalatine fossa. With our technique, the IMA could be easily exposed and sufficiently dissected without zygomatic osteotomy and extensive middle fossa floor removal.

Current perspectives and future directions of the treatment for non acute intracranial artery occlusion / 中国综合临床

Non-acute intracranial artery total occlusion can lead to severe neurological defect and high recurrence rate of stroke.At present, there is no effective treatment recommended by the guidelines.Traditional treatment methods include medical therapy, extracranial-intracranial bypass surgery and minimally invasive endovascular recanalization therapy.In recent years, with the development of microsurgical vascular anastomosis technique and neurosurgical intervention, and the development of interventional materials, the treatment of non-acute intracranial artery total occlusion has become a hot spots.In this paper, the concept of non on-acute intracranial artery total occlusion, medical therapy, extracranial-intracranial bypass surgery and endovascular interventional therapy are reviewed.

Postprandial cerebral infarction resolved by extracranial-intracranial bypass surgery.

A 51-year-old man with type 2 diabetes mellitus was admitted with a 2-month history of repeated episodes of transient aphasia and right hemiparesis after food intake. His blood pressure (BP) fell when the neurological deficits developed. The fall in BP after each meal was confirmed by 24-h ambulatory blood pressure monitoring (ABPM), which established the diagnosis of postprandial hypotension (PPH). Diffusion-weighted magnetic resonance imaging of the brain showed multiple high-intensity lesions at the borderzone between the anterior and middle cerebral artery (MCA) territories in the left hemisphere. Digital subtraction angiography showed tapered occlusion at the origin of the left internal carotid artery (ICA). Despite sufficient antiplatelet therapy and medication for PPH, the transient symptoms remained. Positron emission tomography scanning using H2 15O showed decreased cerebral blood flow with increased oxygen extraction fraction in the left MCA territory. As the symptomatic left ICA occlusion was intractable, an extracranial-intracranial (EC-IC) bypass surgery was conducted without any perioperative complications. Although PPH remained, cerebrovascular ischemic events including repeated transient ischemic attack disappeared for 2 months after surgery. The coincidence of stroke with ABPM-proved transient hypotension suggested that the brain infarcts were caused by hemodynamic changes related to PPH co-existent with the chronic left ICA occlusion. ABPM is useful in evaluating hemodynamic infarcts associated with BP fluctuation, and should be considered for patients with chronic ICA occlusion. In addition, EC-IC bypass may be a treatment option for symptomatic chronic ICA occlusion due to PPH.

Extracranial-intracranial bypass surgery for occlusive atherosclerotic disease of the anterior cerebral circulation: protocol for a systematic review and meta-analysis.

BACKGROUND: Occlusive atherosclerotic disease of the anterior cerebral circulation is one of the most common causes of anterior circulation ischemia and stroke. Treatment options include medical therapies (including antiplatelet use, blood pressure control, lipid reduction, and lifestyle modification) and extracranial-intracranial bypass surgery (such as superficial temporal artery-middle cerebral artery bypass). However, the optimal treatment remains unclear. The objective of this study will be to compare the efficacy of and extracranial-intracranial bypass surgery with that of other medical therapy in adult patients with occlusive atherosclerotic disease of the anterior cerebral circulation. METHODS: This is the study protocol for a systematic review. We will search MEDLINE, EMBASE, Web of Science, and the Cochrane Library (from January 1980 onwards). We will include randomized controlled trials, quasi-experimental studies (non-randomized, interrupted time series), and observational studies (e.g., cohort studies and case-control studies), examining the efficacy of extracranial-intracranial bypass surgery compared to other treatments for adult patients with occlusive atherosclerotic disease of anterior cerebral circulation. Two team members will independently screen all citations, full-text articles, and abstract data. Potential conflicts will be resolved through discussion. The primary outcome will include stroke or death. The secondary outcomes will include intracranial hemorrhage, transient ischemic attack, and myocardial infarction. The study methodological quality (or bias) will be appraised using appropriate tools. If feasible, we will conduct random effects meta-analysis. Additional analyses will be conducted to explore the potential sources of heterogeneity (e.g., study design, geographical location, or risk of bias). DISCUSSION: This review will evaluate the evidence on the efficacy of extracranial-intracranial bypass surgery for adult patients with occlusive atherosclerotic disease of the anterior cerebral circulation. We anticipate that our findings will be of interest to patients, their families, caregivers, healthcare professionals, and in making optimal treatment selection. Implications for future clinical and epidemiological research will be discussed. SYSTEMATIC REVIEW REGISTRATION: PROSPERO CRD42018105513.

Computed tomography perfusion evaluation after extracranial-intracranial bypass surgery.

OBJECTIVE: Perfusion imaging is increasingly used for postoperative evaluation of extracranial to intracranial (EC-IC) bypass surgery. Altered hemodynamics and delayed arrival of the contrast agent in the area fed by the bypass can influence perfusion measurement. We compared perfusion asymmetry obtained with different algorithms in EC-IC bypass surgery patients. METHODS: We retrospectively identified all patients evaluated with computed tomography perfusion (CTP) between May 2007 and May 2011 after EC-IC bypass surgery at our institution. CTP images were analyzed with three perfusion algorithms that differ among their ability to anticipate for delayed arrival time of contrast material: the delay-sensitive first-moment mean transit time (fMTT), the semi-delay-sensitive standard singular value decomposition (sSVD) and the delay-insensitive block-circulant SVD (bSVD). The interhemispheric difference in bolus arrival time (ΔBAT) was determined to confirm altered hemodynamics. Interhemispheric asymmetry in perfusion values (mean transit time (MTT) difference, cerebral blood flow (CBF) ratio and cerebral blood volume (CBV) ratio) was compared between the three algorithms. Presence of a new infarct in the treated hemisphere was evaluated on follow-up imaging and perfusion asymmetry was compared between patients with and without infarction. RESULTS: Twenty-two patients were included. The median interhemispheric difference in ΔBAT was 0.98 s. The median MTT difference was significantly smaller when calculated with the delay-insensitive algorithm than with the other algorithms (0.44 s versus 0.90 s and 0.93 s, p<0.01). The CBF ratio was similar for all algorithms (111.98 versus 112.59 and 112.60). The CBV ratio was similar for all algorithms (113.20 versus 111.95 and 113.97). There was a significant difference in MTT asymmetry between patients with and without infarction with the delay-insensitive algorithm only (1.57 s versus 0.38 s, p=0.04). CONCLUSION: In patients with EC-IC bypass surgery, delay-sensitive algorithms showed larger MTT asymmetry than delay-insensitive algorithms. Furthermore, only the delay-insensitive method seems to differentiate between patients with and without infarction on follow-up.

Arachnoid Membrane Suturing for Prevention of Subdural Fluid Collection in Extracranial-intracranial Bypass Surgery.

OBJECTIVE: Water-tight closure of the dura in extracranial-intracranial (EC-IC) bypass is impossible because the superficial temporal artery (STA) must run through the dural defect. Consequently, subdural hygroma and subcutaneous cerebrospinal fluid (CSF) collection frequently occur postoperatively. To reduce these complications, we prospectively performed suturing of the arachnoid membrane after STA-middle cerebral artery (STA-MCA) and evaluated the clinical usefulness. MATERIALS AND METHODS: Between Mar. 2005 and Oct. 2010, extracranial-intracranial arterial bypass (EIAB) with/without encephalo-myo-synangiosis was performed in 88 cases (male : female = 53 : 35). As a control group, 51 patients (57 sides) underwent conventional bypass surgery without closure of the arachnoid membrane. Postoperative computed tomography (CT) scan was performed twice in three days and seven days later, respectively, for evaluation of the presence of subdural fluid collection and other mass lesions. RESULTS: The surgical result was excellent, with no newly developing ischemic event until recent follow-up. The additional time needed for arachnoid suture was five to ten minutes, when three to eight sutures were required. Post-operative subdural fluid collection was not seen on follow-up computed tomography scans in all patients. CONCLUSION: Arachnoid suturing is simple, safe, and effective for prevention of subdural fluid collection in EC-IC bypass surgery, especially the vulnerable ischemic hemisphere.

Reliability of laser speckle flow imaging for intraoperative monitoring of cerebral blood flow during cerebrovascular surgery: comparison with cerebral blood flow measurement by single photon emission computed tomography.

OBJECTIVE: To determine the clinical utility of laser speckle flow imaging (LSFI) and its comparability to (123)I-iodoamphetamine single photon emission computed tomography (IMP-SPECT), we used LSFI to monitor cerebral blood flow (CBF) during extracranial-intracranial (EC-IC) bypass surgery. METHODS: Intraoperative intensity of CBF (iCBF) by LSFI and preoperative and postoperative CBF by IMP-SPECT were measured in 3 patients with internal carotid artery (ICA) aneurysms who were undergoing ICA trapping surgery and in 16 patients with major cerebral artery occlusion who were undergoing EC-IC bypass surgery. RESULTS: The decrease in iCBF (16.9% ± 2.3%) with ICA interruption was equivalent to the decrease in CBF during the preoperative balloon test occlusion, as measured by IMP-SPECT (12.2% ± 4.4%). Whether preserved iCBF in LSFI promised postoperative intact CBF was not determined, as no patient showed ischemic tolerance by ICA occlusion. The increase in iCBF resulting from EC-IC bypass correlated moderately with the increase in postoperative CBF as measured by IMP-SPECT. However, the increase in iCBF was too small to be recognized intraoperatively by visual inspection. CONCLUSIONS: Although LSFI clearly demonstrated a decrease in CBF, the information is taken only from the surface of the brain. Combined use of LFSI with an electrophysiologic examination is required for intraoperative diagnosis of ischemia. LSFI was not sensitive enough to detect increased CBF by superficial temporal artery-to-middle cerebral artery anastomosis, because CBF changes are minimized during anesthesia, probably owing to low metabolic activity.

Arachnoid Membrane Suturing for Prevention of Subdural Fluid Collection in Extracranial-intracranial Bypass Surgery

OBJECTIVE: Water-tight closure of the dura in extracranial-intracranial (EC-IC) bypass is impossible because the superficial temporal artery (STA) must run through the dural defect. Consequently, subdural hygroma and subcutaneous cerebrospinal fluid (CSF) collection frequently occur postoperatively. To reduce these complications, we prospectively performed suturing of the arachnoid membrane after STA-middle cerebral artery (STA-MCA) and evaluated the clinical usefulness. MATERIALS AND METHODS: Between Mar. 2005 and Oct. 2010, extracranial-intracranial arterial bypass (EIAB) with/without encephalo-myo-synangiosis was performed in 88 cases (male : female = 53 : 35). As a control group, 51 patients (57 sides) underwent conventional bypass surgery without closure of the arachnoid membrane. Postoperative computed tomography (CT) scan was performed twice in three days and seven days later, respectively, for evaluation of the presence of subdural fluid collection and other mass lesions. RESULTS: The surgical result was excellent, with no newly developing ischemic event until recent follow-up. The additional time needed for arachnoid suture was five to ten minutes, when three to eight sutures were required. Post-operative subdural fluid collection was not seen on follow-up computed tomography scans in all patients. CONCLUSION: Arachnoid suturing is simple, safe, and effective for prevention of subdural fluid collection in EC-IC bypass surgery, especially the vulnerable ischemic hemisphere.

Management Options and Prognosis of Carotid Artery Occlusive Disease / 대한뇌혈관외과학회지

OBJECT: The effective management of carotid occlusive disease still remains a challenge to neurosurgeons. The authors analyzed the series of management of carotid occlusive disease in order to determine whether our management strategy affected patient's clinical outcomes. Methods of identifying patients who stand to benefit from this therapy need to be established. METHOD: Clinical findings, management, complications and outcome in 52 patients with high grade carotid stenosis of at least 70% and occlusion were investigated. The patients were treated by percutaneous transluminal angioplasty (PTA) and/or stent (PTAS), Extracranial-Intracranial (EC-IC) bypass surgery, carotid endarterectomy (CEA) according to the neurologic status, medical condition, severerity of stenosis, collateral blood flow. RESULTS: The causes of carotid stenosis were 40 atherosclerosis arteries, 9 spontaneous dissections and 2 traumas, 1 fibomuscular dysplasia (FMD) of 52 patients. 9 patients were treated by PTA alone, and 28 patients by PTAS, 9 patients by EC-IC bypass surgery, 3 patients by PTAS followed by EC-IC bypass surgery, 3 patients by CEA. For the outcome according to management, 26 patients (100% of all bypass surgery only and CEA, 35% of all PTA and PTAS) recovered excellently, 14 patients (35% of all PTA and PTAS) had a good outcome. 2 patients died. CONCLUSION: The results of this study suggest that PTAS should be a useful and effective treatment method for some patients with the severe atherosclerotic stenosis or carotid artery dissection. However, the surgical management must be considered for the high risk, high grade carotid stenosis patients with collateral blood flow, and with or without mild or moderate deficits.

Effectiveness of Bypass Surgery in Treatment and Prevention for Cerebrovascular Occlusive Disease

To study the effect of extracranial-intracranial(EC/IC) bypass on symptomatic patients with hemodynamic cerebral ischemia, we prospectively reviewed 76 patients who underwent EC/IC bypass surgery in patients with occlusive cerebrovascular disease. A series of 76 patients treated in a 7 years period met following criteria. (1) symptomatic internal carotid artery(ICA) or middle cerebral artery(MCA) obstruction or stenosis over 80%. (2) decrease in basal cerebral blood flow(CBF) over 10%. (3) decreased reactivity of CBF in response to acetazolamide. Among these, the types of ischemic episodes were transient ischemic attack(TIA) or reversible ischemic neurological deficit(RIND) in 39, minor stroke in 22, and major stroke in 15. Based on our criteria, superficial temporal artery(STA)-MCA anastomosis was performed in 67 cases and EC-IC bypass grafting using saphenous vein or radial artery in 9. Average follow up period was 26 months(3 months~7 year). Patency of bypass was confirmed by postoperative angiography or magnetic resonence angiography(MRA) in all case except four cases. Of the 72 patients with patiency of bypass, 68 patients(94%) have had an excellent to good outcome with improvement of preoperative neurologic or cognitive dysfunction, 3 patients showed no improvement of preoperative neurologic symptoms and remaining one patient had new developed deficit. All 72 patients with patency of bypass had experienced no further cerebral ischemic events during following period. Postoperative significant improvement of CBF to acetazolamide was showed in 68 cases(94%) of the 72 cases with patency of bypass, while the basal CBF showed significant improved in 31cases. Postoperative permanent neurologic deficit occurred only in one. In view of these finding, the author suggest that EC-IC bypass surgery is a reliable and resonably safe method for establishing new pathways of collateral circulation to the brain and to be considered as an appropriate therapy for improvement of the cerebrovascular reserve capacity in patients with hemodynamic cerebral ischemia, defined using the strict selection criteria employed in this study.

Surgical Treatment of Cerebral Ischemia / 대한뇌혈관외과학회지

Since the proportion of ischemic stroke has been increasing compared to hemorrhagic stroke in our country, only recently the medical community began to systematically emphasize the importance of managing ischemic stroke patients as aggressively as possibly in an attempt to improve outcome and facilitate the development of useful treatment algorithms. It is necessary to estimate initially which vascular territory among large or small artery is compromised for planning treatment strategies in patients with acute ischemic stroke. The author focuses on the efficient assessment and surgical management of patients with acute ischemic stroke by reviewing the operative techniques and perioperative management of carotid endarterectomy and extracranial-intracranial bypass surgery

Current Indication of Extracranial-Intracranial Bypass Surgery / 대한뇌혈관학회지

Since the negative results of the international extracranical-intracranial bypass surgery (EIBS), this procedure is rarely employed in the treatment of patients with ischemic stroke. However, recent evidence suggests that patients with hemodynamic cerebral ischemia (HCI) are at particular risk for subsequent stroke compared to those with similar occlusive lesion but intact cerebrovascular reserve (CVR). Furthermore, several investigators have suggested that EIBS is effective in preventing recurrent ischemic attacks in patients with HCI due to occlusive disease and insufficient collateral blood supply. In addition, EIBS has been frequently used for the patients with moyamoya disease and for the patients who need therapeutic occlusion or sacrifice of a parent vessel during the treatment of complex intra or extracranial aneurysms or cranial base tumors. Based on a review of literature the rationale and the indication of EIBS will be summaried.

Extracranial-Intracranial Bypass Surgery: Surgical Techniques and Perioperative Management / 대한뇌혈관학회지

Options for extracranial-intracranial bypass surgery of anterior circulation include saphenous vein grafts, occipital to middle cerebral artery (MCA) anastomosis, and most commonly superficial temporal artery (STA) to MCA anastomosis. Although less common, posterior circulation revascularization has been successfully peformed. The operative techniques and perioperative management such as anesthetic techniques and electrophysiologic monitoring are reviewed. Finally the author's surgical experiences of STA-MCA anastomosis in 30 patients with symptomatic internal carotid artery or MCA stenoocclusion are reported.

Improvement of Cerebrovascular Reserve Capacity by Bypass Surgery in Patients with Hemodynamic Cerebral Ischemia

To study the effect of extracranial-intracranial(EC/IC) bypass on symptomatic patients with hemodynamic cerebral ischemia, we prospectively reviewed 14 patients who underwent EC/IC bypass surgery. A series of 14 patients treated in a 2 years period met the following criteria, 1) symptomatic internal carotid artery(ICA) or middle cerebral aetery(MCA) obstruction or stenosis over 80M, 2) decrease in basal cerebral blood flow(CBF) over 10%, 3) hyporeactivity to acetazolimide of CBF Amomg these, the type of ischemic episode was transient ischemic attack(TIA) or reversible ischemic neurological deficit(RIND) in 4, minor stroke in 8, and major stroke in 2. Of these, 10 patients had multiple episode of ischemic attack. CT or MRI were showed infarction of the MCA territory in 3, border zone infarction in 5, basal ganglia infarction in 2 and multiple lacunar infarction in 4. Based on our criteria, superficial temporal artery(STA)-MCA anastomosis was performed in 13 cases and EC-IC bypass grafting using radial artery in one. Average follow up period was 24 months. Postoperative course was uneventful in 12 patients. One patient suffered a postoperative stroke with complete recovery and another suffered operative wound infection. Of the 14 patients 12(85.7 % ) have had an excellent to good outcome with complete resolution or significant improvement of preoperative neurologic symptom, remaining two show no improvement of preoperative neurologic deficit. Bypass patency was confirmed by postoperative angiography in all cases except for one. Postoperative follow up studies of the basal CBF and response to the acetazolamide of the CBF showed significant increased CBF activity to acetazolamide in 12 cases(85. 7%) while the basal CBF was essentially unchanged in all cases except for two. In view of these finding, the authors suggest that EC-IC bypass surgery to be considered as an appropritate therapy for improvement of the cerebrovascular reserve capacity in patients with hemodynamic cerebral ischemia, defined using the strict selection criteria employed in this study.