Extracranial-intracranial Bypass Research Articles

Cognitive and cerebral hemodynamic effects of endovascular recanalization of chronically occluded cervical internal carotid artery: single-center study and review of the literature.

Revascularization of a symptomatic, medically refractory, cervical chronically occluded internal carotid artery (COICA) using endovascular techniques (ETs) has surfaced as a viable alternative to extracranial-intracranial bypass. The authors aimed to assess the safety, success, and neurocognitive outcomes of recanalization of COICA using ETs or hybrid treatment (ET plus carotid endarterectomy) and to identify candidate radiological markers that could predict success. The authors performed a retrospective analysis of their prospectively collected institutional database and used their previously published COICA classification to assess the potential benefits of ETs or hybrid surgery to revascularize symptomatic patients with COICA. Subjects who had undergone CT perfusion (CTP) imaging and Montreal Cognitive Assessment (MoCA) testing, both pre- and postprocedure, were included. The authors then performed a review of the literature on patients with COICA to further evaluate the success and safety of these treatment alternatives. The single-center study revealed 28 subjects who had undergone revascularization of symptomatic COICA. Five subjects had CTP imaging and MoCA testing pre- and postrevascularization and thus were included in the study. All 5 patients had very large penumbra involving the entire hemisphere supplied by the ipsilateral COICA, which resolved postoperatively. Significant improvement in neurocognitive outcome was demonstrated by MoCA testing after treatment (preprocedure: 19.8 ± 2.4, postprocedure: 27 ± 1.6; p = 0.0038). Moreover, successful revascularization of COICA led to full restoration of cerebral hemodynamics in all cases. Review of the literature identified a total of 333 patients with COICA. Of these, 232 (70%) showed successful recanalization after ETs or hybrid surgery, with low major and minor complication rates (3.9% and 2.7%, respectively). ETs and hybrid surgery are safe and effective alternatives to revascularize patients with symptomatic COICA. CTP imaging could be used as a radiological marker to assess cerebral hemodynamics and predict the success of revascularization. Improvement in CTP parameters is associated with significant improvement in neurocognitive functions.

Local in situ fibrinolysis for recanalization of an occluded extracranial-intracranial bypass: Technical note

Extracranial-intracranial (EC-IC) bypass is a versatile technique to augment or preserve blood flow when treating cerebrovascular pathologies to prevent ischemic complications. Technical success and good patient outcomes rely on the successful establishment and maintenance of a patent bypass graft. Multiple modalities have been developed to confirm intraoperative graft patency. However, techniques and strategies to manage an occluded bypass are sparsely reported. The authors describe a novel technique for the in situ fibrinolysis utilizing recombinant tissue plasminogen activator (r-tPA) to recanalize an occluded EC-IC bypass following thrombus formation. This technique is feasible and effective in restoring long term EC-IC graft patency without requirement of additional vessel harvest or added ischemia time which may be tailored for use with other pharmacologic agents based on the acuity of an in-graft thrombosis.

Anatomical Assessment of the Temporopolar Artery for Revascularization of Deep Recipients

Intracranial-intracranial and extracranial-intracranial bypass options for revascularization of deep cerebral recipients are limited and technically demanding. To assess the anatomical feasibility of using the temporopolar artery (TPA) for revascularization of the anterior cerebral artery (ACA), posterior cerebral artery (PCA), and superior cerebellar arteries (SCA). Orbitozygomatic craniotomy was performed bilaterally on 8 cadaveric heads. The cisternal segment of the TPA was dissected. The TPA was cut at M3-M4 junction with its proximal and distal calibers and the length of the cisternal segment measured. Feasibility of the TPA-A1-ACA, TPA-A2-ACA, TPA-SCA, and TPA-PCA bypasses were assessed. A total of 17 TPAs were identified in 16 specimens. The average distal TPA caliber was 1.0±0.2 mm, and the average cisternal length was 37.5±9.4 mm. TPA caliber was≥1.0 mm in 12 specimens (70%). The TPA-A1-ACA bypass was feasible in all specimens, whereas the TPA reached the A2-ACA, SCA, and PCA in 94% of specimens (16/17). At the point of anastomosis, the average recipient caliber was 2.5±0.5 mm for A1-ACA, and 2.3±0.7 mm for A2-ACA. The calibers of the SCA and PCA at the anastomosis points were 2.0±0.6 mm, and 2.7±0.8 mm, respectively. The TPA-ACA, TPA-PCA, and TPA-SCA bypasses are anatomically feasible and may be used when the distal caliber of the TPA stump is optimal to provide adequate blood flow. This study lays foundations for clinical use of the TPA for ACA revascularization in well-selected cases.

Factors related to improvement of cerebrovascular reserve after superficial temporal artery to middle cerebral artery anastomosis for patients with atherosclerotic steno-occlusive disease.

This study aimed to investigate factors related to improvement of hemodynamics and evaluated the usefulness of intraoperative Doppler for predicting postoperative hemodynamics in patients with cerebrovascular atherosclerotic steno-occlusive disease (CASD) of the internal carotid artery (ICA) or middle cerebral artery (MCA) who were treated with extracranial-intracranial (EC-IC) bypass surgery. Forty-eight patients with CASD of the ICA or MCA who were treated by superficial temporal artery to middle cerebral artery bypass with a follow-up longer than 12months were enrolled. Repeated transient ischemic attack or completed ischemic stroke was observed under optimal medical therapy in all patients. Intraoperative blood flow velocity of the MCA was evaluated by a Doppler flowmeter. Cerebral blood flow and cerebrovascular reserve (CVR) were evaluated using N-isopropyl-[123I] p-iodoamphetamine (IMP) single photon emission computed tomography (SPECT) preoperatively and 3months after surgery. Imaging and clinical data were retrospectively reviewed. CVR was significantly increased postoperatively (p = 0.03). One year after the operation, two (4.2%) patients developed cerebral infarction. The change in MCA flow velocity just after anastomosis compared with pre-anastomosis proximal and distal of the anastomosis site was a median of 3.0 and 2.6 times, respectively. However, there was no significant association between changes in intraoperative MCA flow velocity and postoperative CVR. Multivariate analysis showed that the presence of a lower estimated glomerular filtration rate (eGFR) was an independent risk factor for a decrease in CVR (p = 0.036). A higher eGFR might have prognostic value for improvement in CVR after EC-IC bypass surgery in patients with CASD and misery perfusion.

Indocyanine Green and Contrast-Enhanced Ultrasound Videoangiography: A Synergistic Approach for Real-Time Verification of Distal Revascularization and Aneurysm Occlusion in a Complex Distal Middle Cerebral Artery Aneurysm

Distal outflow occlusion and extracranial-intracranial bypass represent a possible option for the surgical management of complex middle cerebral artery (MCA) aneurysm. A limitation of the distal clipping strategy combined to bypass is related to the difficulties in predicting intraoperatively the good blood flow supply to the brain territory distal to the aneurysm and the extent and speed of aneurysmal thrombosis. We present an innovative approach in which contrast-enhanced ultrasound (CEUS) and indocyanine green videoangiography (ICG-VA) have been synergistically used to study the effect of distal clipping on the aneurysm flow and the parenchymal blood flow after the bypass. We used this approach in a patient harboring a fusiform, partially thrombosed distal left MCA aneurysm. The patient was treated by a superficial temporal artery-MCA bypass, followed by MCA clipping immediately distally to the aneurysm. ICG-VA was used to evaluate bypass patency and brain perfusion in the area supplied by the bypass. CEUS was used to confirm the characteristics of the aneurysm and to explore the proximal MCA compartment immediately after dural opening, and to verify in real time the effect on aneurysm flow determined by distal outflow occlusion. Postoperative imaging confirmed aneurysm occlusion and patency of the bypass. The patient did not experience any neurologic sequelae. We present the first report of a synergistic intraoperative utilization of ICG-VA and CEUS in studying parenchymal perfusion and aneurysm flow in complex neurovascular procedures.

Review of first clinical experiences with a 1.5 Tesla ceiling-mounted moveable intraoperative MRI system in Europe.

High-field intraoperative MRI (iMRI) systems provide excellent imaging quality and are used for resection control and update of image guidance systems in a number of centers. A ceiling-mounted intraoperative MRI system has several advantages compared to a conventional iMRI system. In this article, we report on first clinical experience with using such a state-of-the-art, the 1.5T iMRI system, in Europe. A total of 50 consecutive patients with intracranial tumors and vascular lesions were operated in the iMRI unit. We analyzed the patients' data, surgery preparation times, intraoperative scans, surgical time, and radicality of tumor removal. Patients' mean age was 46 years (range 8 to 77 years) and the median surgical procedure time was 5 hours (range 1 to 11 hours). The lesions included 6 low-grade gliomas, 8 grade III astrocytomas, 10 glioblastomas, 7 metastases, 7 pituitary adenomas, 2 cavernomas, 2 lymphomas, 1 cortical dysplasia, 3 aneurysms, 1 arterio-venous malformation and 1 extracranial-intracranial bypass, 1 clival chordoma, and 1 Chiari malformation. In the surgical treatment of tumor lesions, intraoperative imaging depicted tumor remnant in 29.7% of the cases, which led to a change in the intraoperative strategy. The mobile 1.5T iMRI system proved to be safe and allowed an optimal workflow in the iMRI unit. Due to the fact that the MRI scanner is moved into the operating room only for imaging, the working environment is comparable to a regular operating room.

Progressive Cerebral Ischemia and Intracerebral Hemorrhage after Indirect Revascularization for a Patient with Cerebral Proliferative Angiopathy

We previously reported a patient with cerebral proliferative angiopathy (CPA) who showed cerebral ischemia in resting and acetazolamide-stressed N-isopropyl-p-[123I] iodoamphetamine single-photon emission computed tomography (123I-IMP-SPECT). At onset, the patient was treated conservatively. However, during the 2 years following initial onset, his hemiparesis and aphasia had gradually aggravated and his IQ scores were markedly decreased. MRI revealed progressive vascular proliferation and brain atrophy. 123I-IMP-SPECT showed more severely impaired cerebral blood flow (CBF) and cerebrovascular reactivity over the affected hemisphere. We performed an indirect revascularization to augment CBF; however, his neurological deficits were not improved and new arteriovenous shunts via extracranial-intracranial bypass were developed, followed by an asymptomatic small intracerebral hemorrhage.There are no reports on CPA patients who have shown cerebral hemorrhage after indirect revascularization. Treatments for CPA are still challenging and controversial. Cases with severe stenosis of the proximal arteries may benefit from indirect revascularization. But indirect bypass should not be indicated for such patients without main arterial stenosis, even if they have persistent ischemia.

Clinical factors influencing the development of extracranial-intracranial bypass graft for steno-occlusive cerebrovascular disease.

OBJECTIVEEffectively retaining the patency of the extracranial-intracranial (ECIC) bypass is one of the most important factors in improving long-term results; however, the factors influencing bypass patency have not been discussed much. Therefore, the authors investigated factors influencing the development of the bypass graft.METHODSIn this retrospective study, the authors evaluated 49 consecutive hemispheres in 47 adult Japanese patients who had undergone ECIC bypass for chronic steno-occlusive cerebrovascular disease. To evaluate objectively the development of the ECIC bypass graft, the change in the area of the main trunk portion of the superficial temporal artery (STA) from before to after bypass surgery (postop/preop STA) was measured. Using the interquartile range (IQR), the authors statistically analyzed the factors associated with excellent (> 3rd quartile) and poor development (< 1st quartile) of the bypass graft.RESULTSThe postop/preop STA ranged from 1.08 to 6.13 (median 1.97, IQR 1.645-2.445). There was a significant difference in the postop/preop STA between the presence and absence of concurrent diabetes mellitus (p = 0.0432) and hyperlipidemia (0.0069). Furthermore, logistic regression analysis revealed that only concurrent diabetes mellitus was significantly associated with poor development of the bypass graft (p = 0.0235).CONCLUSIONSDiabetes mellitus and hyperlipidemia influenced the development of the ECIC bypass graft. In particular, diabetes mellitus is the only factor associated with poor development of the bypass graft.

Abstract TP523: A Randomized Controlled Trial Evaluating the Effectiveness of Pretreatment With the Free Radical Scavenger, Edaravone, Before Carotid Artery Stenting

Objective: Cerebral hyperperfusion syndrome (CHS) is likely to occur after carotid revascularization in patients with severe hemodynamic failure. It is important to control cerebral hyperperfusion phenomenon (CHP) to prevent the development of CHS. To determine whether pretreatment with the free radical scavenger, edaravone, could prevent the onset of CHP after carotid artery stenting (CAS). Methods: Patients with severe carotid artery stenosis were randomized to receive either pretreatment with edaravone immediately before CAS or the common CAS procedure. Cerebral blood flow (CBF) was assessed in the affected middle cerebral artery (MCA) region and in the ipsilateral cerebellum using single-photon emission computed tomography (SPECT) of the brain before and immediately after CAS. Cerebrovascular reactivity (CVR) in the MCA region was also evaluated using the stereotactic extraction estimation based on the Japanese extracranial-intracranial bypass trial (SEE-JET) program and classified as reduced when it was &lt;18.4%. The ratio of MCA to cerebellar activity was defined as the CBF in the affected MCA region divided by the CBF in the ipsilateral cerebellar hemisphere. CHP was defined as an increase in the ratio of MCA to cerebellar activity after CAS ≥10%. Results: Of the 52 patients recruited in this study, 26 were assigned to the pretreatment with edaravone group and 26 were assigned to the treatment as the usual group. Eleven patients showed reduced CVR. CHP occurred in 0 of 6 patients in the edaravone group and in 4 of 5 patients in the usual group (0% vs. 80%, p=0.0152). However, there was no significant difference in the overall patient population between the two groups. Conclusion: Pretreatment with edaravone could reduce the incidence of CHP after CAS in patients with reduced CVR.

Extracranial-intracranial bypass approach to cerebral revascularization: a historical perspective

While the majority of cerebral revascularization advancements were made in the last century, it is worth noting the humble beginnings of vascular surgery throughout history to appreciate its progression and application to neurovascular pathology in the modern era. Nearly 5000 years of basic human inquiry into the vasculature and its role in neurological disease has resulted in the complex neurosurgical procedures used today to save and improve lives. This paper explores the story of the extracranial-intracranial approach to cerebral revascularization.

Aneurysms of the pericallosal artery (literature review)

The study objective is to analyze scientific sources describing features of surgical treatment of aneurysms of the pericallosal artery (APcA) and unfavorable outcome risk factors.Materials and methods. The analysis included 4 russian and 57 foreign sources.Results and conclusion. Conservative treatment of patients with ruptured APcAs yields unsatisfactory results due to high mortality. Data on surgical outcomes of ruptured APcAs are contradictory: per some sources, they do not differ from results of treatment of cerebral aneurysms of other locations; another sources state that they are worse. The main risk factors are severity per the Hunt–Hess scale ≥IV, large size of intracranial hematoma. Outcomes of surgical treatment of unruptured aneurysms are mostly favorable. Microsurgical clipping allows to achieve favorable results both for ruptured and unruptured APcAs. Due to deep APcA localization, the majority of revascularization surgeries can be performed only using intracranial-to-intracranial bypass. Extracranial-intracranial bypass in the anterior cerebral artery system is rarely performed. For surgical treatment, choice of its timeframe in critically ill patients (grade IV–V by the Hunt–Hess scale) causes difficulties: early surgery prevents repeated hemorrhages, while postponed surgeries eliminate the possibility of affecting this and other factors. There are arguments for preventive exclusion of APcA from blood flow even if its size is &lt;5 mm because of high frequency of APcA ruptures and more severe consequences. For combination of an unruptured APcA with a ruptured aneurysm in another location, either simultaneous exclusion of all aneurysms is performed or two-stage surgery with primary exclusion of the ruptured aneurysm, but the first approach is not always possible. Selection of optimal approach depends on the location of the aneurysm: pterional approach is used for clipping infracallosal aneurysms, variations of interhemispheric accesses – for exclusion of supracallosal aneurysms and aneurysms located at the genu of corpus collosum. Temporary pharmacological cardioplegia is considered a promising method which potentially can replace temporary APcA clipping.

Long-Term Effects on Preventing Stroke after Endovascular Treatment or Bypass Surgery for Intracranial Arterial Stenosis

Background: Intracranial arterial stenosis (ICAS) is an important cause of ischemic stroke worldwide due to its higher risk of recurrence with medical therapy. Although some large randomized studies failed to show the superiority of surgical treatment compared with medical therapy, the results of medical therapy are not sufficient. There are patients who still benefit from surgical treatment. This retrospective analysis aimed to evaluate the long-term efficacy of surgical therapy with percutaneous transluminal angioplasty and/or stenting (PTA/PTAS) or extracranial-intracranial (EC/IC) bypass surgery for patients with ICAS. Methods: Between October 2005 and December 2016, 55 ICAS patients were treated with PTA/PTAS or EC-IC bypass surgery. Their electronic medical records were retrospectively reviewed and analyzed. The primary outcome was all adverse events beyond 30 days after a revascularization procedure. Results: We performed 21 cases (35%) of PTA, 4 cases (7%) of PTAS, and 34 cases (58%) of EC-IC bypass surgery and the median follow-up duration was 66 months (range 1-144 months). The occurrence rate of the primary outcome was 10.2% and only 1 patient (1.8%) experienced ipsilateral disabling ischemic stroke beyond 30 days. The long-term functional independent survival rate was 83.6%. Conclusions: We demonstrated a long-term favorable outcome of combined surgical intervention for ICAS patients with PTA/PTAS and EC-IC bypass surgery, and the result was better than previously reported outcomes of medical therapy. Additional multicenter studies are required to draw firm conclusions on the efficacy of reduction of recurrent stroke in patients with ICAS.

A Modified Encephalo-Duro-Synangiosis Technique Induced Neovascularization in Symptomatic Atherosclerotic Carotid Artery Occlusion: A Phase I trial

To the best of our knowledge, the present study is the first to assess the safety and feasibility of a modified encephalo-galeo-duro-synangiosis operation in patients with atherosclerotic carotid artery occlusion. Eight patients who had experienced new ipsilateral cerebrovascular events after the diagnosis of carotid artery occlusion were recruited. To facilitate extracranial-to-intracranial collateralization, 5 or 6 burr holes were made, and the dura mater and arachnoid were opened. The patients were closely monitored for complications and underwent conventional angiography, magnetic resonance imaging, and perfusion-weighted magnetic resonance imaging at baseline and 1 year of follow-up. After 10 years, the patients who were still alive were interviewed and assessed for functional outcomes and neurological status. No surgery-related adverse events were observed, apart from temporary headache and subcutaneous effusion. Four of six patients had developed an extracranial-to-intracranial collateral blood vessels on angiography, and these patients had no incident ischemic events during the follow-up period. During the long-term follow-up period (10 years), 3 patients had died. Of those living, 4 of the 5 patients reported total resolution of the symptoms, with no incident ischemic events. One patient still experienced disability from an ischemic stroke that occurred as a result of the 1-year follow-up angiography. Encephalo-duro-galeo-synangiosis for symptomatic carotid occlusion seems to be safe and feasible and might be able to induce extracranial-to-intracranial collaterals in patients with carotid artery occlusion. Further studies are needed to define the optimal therapeutic window and yield of burr hole surgery in the treatment of symptomatic carotid occlusive disease as an adjuvant to extracranial-intracranial bypass.

Utilization and safety of extracranial-intracranial bypass surgery in symptomatic steno-occlusive disorders.

OBJECTIVE:The objective of this study was to investigate patterns of utilization and safety of extracranial–intracranial (EC-IC) bypass in patients with symptomatic cerebrovascular steno-occlusive disorders.METHODS:Patients with one of the steno-occlusive conditions (defined as symptomatic intracranial stenosis, extracranial stenosis, and moyamoya disease) were identified using all nonfederal hospitalizations in New York (2005–2014) and Florida (2005–2015). EC-IC bypass surgery was defined using the corresponding procedure codes. Patients were included if there was a prior history of ischemic stroke or transient ischemic attack. Patients were excluded for any preceding diagnosis of cerebral hemorrhage, aneurysm, or trauma. The primary outcome was perioperative ischemic stroke, cerebral hemorrhage, or mortality occurring within 30 days of surgery. We also determined yearly trends for the volume of EC-IC bypass procedures in the study period.RESULTS:Among 346 patients with steno-occlusive disease treated with EC-IC bypass, median age was 52.5 years and 52.5% were female. Rates of EC-IC bypass surgery procedure increased until 2011 and then decreased coinciding with the publication of the Carotid Occlusion Surgery Study trial. Thirty-day event rates of stroke, hemorrhage, or death decreased in patients treated with EC-IC bypass (odds ratio: 0.2, confidence interval: 0.0.4–0.99; P = 0.03) over the 10-year study period.CONCLUSIONS:Overall utilization of EC-IC bypass procedure is relatively low, whereas the 30-day complication rates for patients with steno-occlusive conditions appear to be relatively low and improving. Further research is needed to confirm these findings and to determine the subset of patients who would most likely benefit from this intervention.

Minimally Invasive Exposure of the Maxillary Artery at the Anteromedial Infratemporal Fossa.

The maxillary artery (MA) has been described as a reliable donor for extracranial-intracranial high-flow bypass. Existing techniques to harvest MA require brain retraction and drilling of the middle fossa (with or without a zygomatic osteotomy), carrying the potential risks of venous bleeding, injury to the branches of the maxillary or mandibular nerves, muscular transection, or temporomandibular junction disorders. To describe a novel technique to expose the MA without bony drilling and with minimal impact to surrounding structures. A conventional curvilinear incision was performed in 10 cadaveric specimens, prior to elevating the scalp to expose the zygomatic root and lateral orbital rim. The sphenozygomatic suture was followed to the anterolateral edge of the inferior orbital fissure (IOF) to locate and harvest the pterygoid segment of the MA. Topographic anatomy was assessed using surrounding landmarks and 3D Cartesian coordinates to define the surgical area. The number of visible MA branches and their lengths were recorded. The MA was successfully exposed in all specimens. This approach allowed 6 branches of MA to be exposed. The average length of exposure was 23.3±8.3 mm and the average surgical area was 2.8±0.9 cm2. The IOF was 11.5±4.2 mm from the MA. Our technique provides landmarks to identify the distal pterygoid segment of MA as a donor for extracranial-intracranial bypasses without the need for additional craniectomies. Clear anatomical landmarks, including the sphenozygomatic suture, anterolateral edge of IOF, infraorbital artery, and the pterygomaxillary fissure defined a trajectory to efficiently localize the MA with minimal risk to surrounding structures.

Local cerebral hemodynamics following STA-MCA bypass in patients with symptomatic carotid occlusions

To assess changes in local hemodynamic parameters in patients with symptomatic ICA occlusions and moyamoya disease after placement of extracranial-intracranial bypass (EC-IC bypass). The study included 112 patients who underwent surgical treatment at the National Scientific and Practical Center for Neurosurgery in the period between 1999 and 2015. Of these, 105 patients had ICA occlusions, and 7 patients had moyamoya disease. During the main stage of EC-IC bypass placement, all patients were monitored for local hemodynamic parameters using intraoperative contact Doppler ultrasonography - 89 (72%) patients (72%) and flowmetry - 56 (50%)). In 33 (29%) cases, both techniques were used. Forty two patients underwent preoperative SCT perfusion to assess the degree of perfusion deficit. Grade 1 cerebrovascular insufficiency (acute oligemia) was detected in 6 patients; grade 2 perfusion deficit (persistent oligemia) was found in 25 patients; grade 3 perfusion deficit (chronic oligemia) was present in 11 patients. Measurements were performed before bypass placement: the blood flow direction and hemodynamic parameters in the cortical arteries were evaluated; and after bypass placement: blood flow values and directions in the cortical artery, proximal and distal to the bypass area, were assessed. A total of 112 EC-IC bypasses were placed without perioperative complications and deaths. Bypass functioning was confirmed in 108 (96.3%) cases; bypass thrombosis occurred in 4 (3.7%) cases. The distal blood flow direction was observed in patients with ICA occlusions (105 patients) in all cases before EC-IC bypass placement. Patients with moyamoya disease had more often the proximal blood flow direction - 5 (71%) out of 7 cases. The cerebral blood flow parameters obtained in this study differed significantly, depending on the baseline degree of perfusion deficit. The blood flow rate was minimal in patients with grade 1 cerebrovascular insufficiency. After revascularization, local hemodynamics in the cortical arteries was significantly dependent on the ability of EC-IC bypass to reverse blood flow in the proximal acceptor artery. A change in the blood flow direction was observed in 86 (77%) cases. The mean volumetric blood flow in EC-IC bypass was 34.2±5.7 mL/min. The knowledge of baseline hemodynamic parameters and their changes after revascularization plays an important role in choosing the correct surgical technique, further bypass functioning, and, as a result, improvement of the clinical outcome after surgery.

Extracranial-intracranial bypass and aneurysm trapping for the treatment of large and giant paraclinoid carotid aneurysms

Objective To explore the methods and effects of extracranial-intracranial (EC-IC) bypass and aneurysm trapping for the treatment of large and giant paraclinoid aneurysms. Methods The clinical data of 12 patients with paraclinoid aneurysms were analyzed retrospectively. Those patients were admitted to Department of Neurosurgery, the First Affiliated Hospital of Soochow University between April 2014 and February 2018. There were totally 12 aneurysms in 12 patients, including 8 giant and 4 large aneurysms. There were 1 case of postoperative bleeding of aneurysm embolization and 1 case of thrombotic aneurysms and 1 case of blood blister-like aneurysm. All cases underwent EC-IC high flow bypass and trapping of the aneurysms. The outcomes were evaluated based on the Glasgow Outcome Scale (GOS). Results Intraoperative fluorescein angiography and ultrasound suggested bridge vascular patency. The assessment at discharge indicated a GOS of 4-5 (good outcome) in 9 cases and GOS of 2-3 (severe disability) in 3 cases. There was no death. One was lost to follow-up. Eleven patients were followed up for 6-46 months post operation. The GOS of 4-5 (good outcome) was reported in 10 cases and 2 (severe disability) in 1 case. The bridge vascular patency was revealed in 10 cases. Conclusion The operation of EC-IC bypass combined with aneurysm trapping seems effective in the treatment of large and giant paraclinoid aneurysms. Key words: Intracranial aneurysm; Carotid artery, internal; Treatment outcome; Prognosis; Cerebral revascularization

Clip reconstruction of a giant internal carotid artery bifurcation aneurysm in hybrid operating room: 2-Dimensional operative video

Giant internal carotid artery (ICA) bifurcation aneurysms are technically difficult to treat because of lack of a definable neck, which makes direct clipping impossible. In addition, these lesions are related to multiple perforating arteries, posing a different challenge to surgical operators. This video demonstrates clip reconstruction of a giant ICA bifurcation aneurysm in a hybrid operating room. A 32-year-old female presented with dizziness for one year. Angiography demonstrated a giant left ICA bifurcation aneurysm. The patient was consented for both clip reconstruction and extracranial-intracranial bypass if needed. A left pterional craniotomy was performed. After dural opening, the sylvian fissure was opened widely until the aneurysm was identified. The proximal ICA was then identified. The aneurysm projected posteriorly, involving the origins of both the A1 and M1 segments. After temporary clipping, the critical perforators were dissected free from the aneurysm wall. Tandem fenestrated clipping was used to reconstruct the parent artery. Finally, curved clips were used to occlude the distal part of the neck. Vessel patency was evaluated using intraoperative Doppler and indocyanine green angiography. Intraoperative somatosensory and motor evoked potential monitoring remained unchanged after final clipping. Intraoperative angiography confirmed complete obliteration of the aneurysm and reconstruction of the parent artery. The patient recovered well without any complications. Giant ICA bifurcation aneurysms are complex lesions that require preoperative planning and intraoperative monitoring. Adherence to general principles, including careful dissection of aneurysmal wall from adjacent perforators and clip reconstruction using tandem fenestrated clipping, these lesions can be treated safely and effectively.

Direct Bypass Surgery Vs. Combined Bypass Surgery for Hemorrhagic Moyamoya Disease: A Comparison of Angiographic Outcomes.

Objective: Extracranial-intracranial bypass is currently recognized as the optimal treatment for hemorrhagic-type moyamoya disease (MMD) which reduces incidence of rebleeding. Recent studies have reported the advantage of combined bypass over direct bypass for the general MMD patients. However, the effect of direct bypass and combined bypass surgery specifically for hemorrhagic-type MMD had not been investigated yet.Methods: Hemorrhagic-type MMD patients who underwent direct and combined bypass surgery with complete clinical and radiological documentation from a multicenter cohort between 2009 and 2017 were retrospectively included. Surgical methods included superficial temporal artery-middle cerebral artery (STA-MCA) anastomosis (direct bypass), combined STA-MCA bypass with encephalodurosynangiosis (EDS), and combined STA-MCA bypass with encephaloduroarteriosynangiosis (EDAS). Matsushima standard on follow-up catheter angiography was used to assess surgical outcome. Modified Rankin Scale, incidence of rebleeding and ischemia during follow-up were recorded. Rebleeding-free survival rates between direct and combined bypass were compared by Kaplan-Meier analysis.Results: Sixty eight hemorrhagic-onset MMD patients were included in this study, among which 71 hemispheres were treated with surgery (direct bypass: 17; bypass+EDS: 24; bypass+EDAS: 30). Forty six (64.8%) hemispheres had satisfactory revascularization (Matsushima level 2–3) and 26 (36.6%) had poor neoangiogenesis. Matsushima level was not significantly different between surgical groups (P = 0.258). Good neoangiogenesis from dural grafts was achieved in 26 (36.6%) hemispheres, and good neoangiogenesis from STA grafts was only seen in 4 (out of 30, 12.5%) hemispheres. Multivariate analysis showed bypass patency [P < 0.001, OR (95%CI): 13.41 (3.28–54.80)] and dural neoangiogenesis [P < 0.001, OR (95%CI): 13.18 (3.26–53.36)] both independently contributed to good angiographic outcome. During follow-up, incidences of rebleeding or ischemic events, and re-bleeding free survival rate were not significantly different between surgical groups (P = 0.433, P = 0.559, and P = 0.997). However, patients who underwent combined bypass surgery had significantly lower mRS at follow-up comparing to patients who underwent direct bypass (P = 0.006).Conclusion: Combined bypass surgery and direct bypass surgery offered similar revascularization for hemorrhagic MMD. Bypass patency and dural angiogenesis both contributed to revascularization independently. The potential of indirect bypass to grow new vessels in hemorrhagic-MMD patients was generally limited, but dural leaflets offered better neoangiogenesis than STA grafts and was therefore recommended for surgical revascularization of hemorrhagic MMD.

Microsurgical treatment strategy for large and giant aneurysms of the internal carotid artery

ObjectiveWe aimed to summarize our microsurgical treatment results for large (10–25 mm) and giant (≥25 mm) intradural internal carotid artery (ICA) aneurysms over a 7-year period at a single institution and to describe our detailed strategy. Patients and methodsWe reviewed the records of 68 patients with 69 aneurysms, including large and giant intradural ICA aneurysms, treated using microsurgical techniques from January 2008 to December 2014. We used adenosine-induced cardiac standstill or retrograde suction decompression for some aneurysm clipping cases and performed bypass surgery if needed. ResultsFifty-eight large and giant ICA aneurysms (84%) were treated with direct clipping, including 6 aneurysms (9%) clipped using adenosine-induced cardiac standstill and 10 aneurysms (14%) clipped using suction decompression. Eleven unclippable aneurysms (16%) were trapped with extracranial-intracranial bypass. Good or excellent results (modified Rankin Scale scores 0–2) were obtained in 47 patients with unruptured aneurysms (92%) and in 14 patients with ruptured aneurysms (82%) at the 6-month follow-up. Of 17 patients with visual disturbances before treatment, 11 (65%) had improved vision after surgical treatment. A remnant sac was found in 20 cases (29%) on digital subtraction angiography performed immediately postoperatively. At the median follow-up of 22 months, we encountered 3 recurrent aneurysm cases (5%) among the 58 aneurysms that were followed up. ConclusionOur study demonstrated that microsurgical treatment of large and giant intradural ICA aneurysms remains competitive to flow-diverting treatment, if the surgeon is prepared to perform multifarious surgical methods, including adenosine administration, retrograde suction decompression, and bypass vascular anastomosis.