Complex Middle Cerebral Artery Aneurysms Research Articles

319 A Case Series of Direct Multi-territory Cerebral Revascularizations Using a Three-Vessel Anastomosis

INTRODUCTION: The ability to perform simultaneous, multi-territory cerebral bypass using a single interposition graft has significant utility for the revascularization of multiple cerebral territories that would otherwise require multiple constructs, serial anastomoses, or a combination of direct and indirect approaches. METHODS: Peri-operative data and outcomes were collected retrospectively for patients undergoing multi-territory cerebral revascularization using a three-vessel anastomosis over a 4-year period (2019-2023). RESULTS: Five patients underwent triple vessel bypass (median age 53 years [range 12-73]). Three patients with complex middle cerebral artery (MCA) aneurysms (one ruptured) were treated multi-territory external carotid artery (ECA)-M2-M2 revascularization using a saphenous vein interposition graft, followed by either proximal ligation or partial/complete aneurysm clip trapping. Two patients with predominately bilateral anterior cerebral artery (ACA) territory moyamoya disease were treated with proximal superficial temporal artery (STA)-A3-A3 revascularization using a radial artery or radial artery fascial flow-through free flap (RAFF) graft. Bypass patency was 100% and zero patients experienced surgery-related ischemia. One patient had new strokes from vasospasm after subarachnoid hemorrhage. One patient required a revision surgery for a post-operative hematoma and RAFF debridement that did not affect bypass patency or neurologic outcome. Median Glasgow Outcome Scale (GOS) and modified Rankin Scale (mRS) scores on discharge were 4 (range 3-5) and 2 (range 0-5), respectively. GOS and mRS scores were stable or improved on follow up in 4/5 patients; one patient died from medical complications of their original stroke. CONCLUSIONS: In experienced hands, three-vessel anastomosis can be a viable option for the safe, simultaneous revascularization of multiple ACA and MCA territories.

Navigating Complexity: A Comprehensive Approach to Middle Cerebral Artery Aneurysms.

Background: The concept of aneurysm "complexity" has undergone significant changes in recent years, with advancements in endovascular treatments. However, surgical clipping remains a relevant option for middle cerebral artery (MCA) aneurysms. Hence, the classical criteria used to define surgically complex MCA aneurysms require updating. Our objective is to review our institutional series, considering the impacts of various complexity features, and provide a treatment strategy algorithm. Methods: We conducted a retrospective review of our institutional experience with "complex MCA" aneurysms and analyzed single aneurysmal-related factors influencing treatment decisions. Results: We identified 14 complex cases, each exhibiting at least two complexity criteria, including fusiform shape (57%), large size (35%), giant size (21%), vessel branching from the sac (50%), intrasaccular thrombi (35%), and previous clipping/coiling (14%). In 92% of cases, the aneurysm had a wide neck, and 28% exhibited tortuosity or stenosis of proximal vessels. Conclusions: The optimal management of complex MCA aneurysms depends on a decision-making algorithm that considers various complexity criteria. In a modern medical setting, this process helps clarify the choice of treatment strategy, which should be tailored to factors such as aneurysm morphology and patient characteristics, including a combination of endovascular and surgical techniques.

Three-Vessel Anastomosis for Direct Multiterritory Cerebral Revascularization: Case Series.

Cerebral revascularization of multiple territories traditionally requires multiple constructs, serial anastomoses, or a combination of direct and indirect approaches. A novel 3-vessel anastomosis technique allows for direct, simultaneous multiterritory cerebral revascularization using a single interposition graft. We herein present our experience with this approach. Retrospective review of perioperative data and outcomes for patients undergoing multiterritory cerebral revascularization using a 3-vessel anastomosis from 2019 to 2023. Five patients met inclusion criteria (median age 53 years [range 12-73]). Three patients with complex middle cerebral artery aneurysms (1 ruptured) were treated with proximal ligation or partial/complete clip trapping and multiterritory external carotid artery-M2-M2 revascularization using a saphenous vein interposition graft. Two patients with moyamoya disease, prior strokes, and predominately bilateral anterior cerebral artery hypoperfusion were treated with proximal superficial temporal artery-A3-A3 revascularization using a radial artery or radial artery fascial flow-through free flap graft. No patients experienced significant surgery-related ischemia. Bypass patency was 100%. One patient had new strokes from vasospasm after subarachnoid hemorrhage. One patient required a revision surgery for subdural hematoma evacuation and radial artery fascial flow-through free flap debridement, without affecting bypass patency or neurologic outcome. On hospital discharge, median Glasgow Outcome Scale and modified Rankin Scale scores were 4 (range 3-5) and 2 (range 0-5), respectively. On follow-up, 1 patient died from medical complications of their presenting stroke; Glasgow Outcome Scale and modified Rankin Scale scores were otherwise stable or improved. The 3-vessel anastomosis technique can be considered for simultaneous revascularization of multiple intracranial territories.

Arterial Bypass in the Treatment of Complex Middle Cerebral Artery Aneurysms: Lessons Learned from Forty Patients

Complex middle cerebral artery (MCA) aneurysms incorporating parent or branching vessels are often not amenable to standard microsurgical clipping or endovascular embolization treatments. We aim to discuss the treatment of such aneurysms via a combination of surgical revascularization and aneurysm exclusion based on our institutional experience. Thirty-four patients with complex MCA aneurysms were treated with bypass and aneurysm occlusion, 5 with surgical clipping or wrapping only, and 1 with aneurysm excision and primary reanastomosis. Bypasses included superficial temporal artery (STA)-MCA, double-barrel STA-MCA, occipital artery-MCA, and external carotid artery-MCA. After bypass, aneurysms were treated by surgical clipping, Hunterian ligation, trapping, or coil embolization. The average age at diagnosis was 46 years. Of the aneurysms, 67% were large and most involved the MCA bifurcation. Most bypasses performed were STA-MCA bypasses, 12 of which were double-barrel. There were 2wound-healing complications. All but 2 of the aneurysms treated showed complete occlusion at the last follow-up. There were 3 hemorrhagic complications, 3 graft thromboses, and 4 ischemic insults. The mean follow-up was 73months. Of patients, 83% reported stable or improved symptoms from presentation and 73% reported a functional status (Glasgow Outcome Scale score 4 or 5) at the latest available follow-up. Cerebral revascularization by bypass followed by aneurysm or parent artery occlusion is an effective treatment option for complex MCA aneurysms that cannot be safely treated by standard microsurgical or endovascular techniques. Double-barrel bypass consisting of 2 STA branches to 2 MCA branches yields adequate flow replacement in most cases.

Cerebral revascularization for complex middle cerebral artery aneurysms: surgical strategies and outcomes in a single center

Cerebral revascularization is the ultimate treatment for a subset of complex middle cerebral artery (MCA) aneurysms. The decision for the revascularization strategy should be made during the treatment process. This study aimed to summarize the revascularization strategies for different types of complex MCA aneurysms and their outcomes. The clinical data of patients with complex MCA aneurysms who underwent cerebral revascularization since 2015 were analyzed retrospectively. The aneurysms were classified according to the location and other main characteristics that affect the selection of surgical modalities. The corresponding surgical modalities and treatment outcomes were summarized. A total of 29 patients with 29 complex MCA aneurysms were treated with cerebral revascularization from 2015 to 2022. Treated aneurysms were located at the prebifurcation segment in 7 patients, bifurcation segment in 12 patients, and postbifurcation segment in 10 patients. Surgical modalities in the prebifurcation segment included four high-flow extracranial-to-intracranial (EC-IC) bypasses with aneurysm trapping or proximal occlusion, two IC-IC bypasses with aneurysm excision, and one combination bypass with aneurysm excision. In the bifurcation segment, surgical modalities included two low-flow EC-IC bypasses with aneurysm excision or trapping, six IC-IC bypasses with aneurysm excision, three combination bypasses with aneurysm excision, and one constructive clipping with IC-IC bypass. In the postbifurcation segment, surgical modalities included nine IC-IC bypasses with aneurysm excision and low-flow EC-IC bypass with aneurysm trapping. The revascularization strategy for prebifurcation aneurysms was determined based on the involvement of lenticulostriate arteries, whereas the strategy for bifurcation aneurysms was determined based on the number of distal bifurcations and the shape of the aneurysm. The location of the aneurysm determined the revascularization strategy for aneurysms in the postbifurcation segments. Angiography demonstrated that aneurysms were completely obliterated in 26 cases and shrank in 3 cases, and all bypasses except one were patent. The mean follow-up period was 47.5months. Three patients developed hemiplegic paralysis, and one developed transient aphasia postoperatively due to cerebral ischemia. No new neurological dysfunction occurred in the other 25 patients with no recurrence or enlargement of aneurysms during the follow-up. Prebifurcation aneurysms involving the lenticulostriate arteries require proximal occlusion with high-flow bypass. Most of the other aneurysms can be safely excised or trapped by appropriate revascularization strategies according to their location and orientation.

‘Y’-Shaped Palmar Common Digital Artery Interposition Bypass in the Treatment of an Infantile M2 Large Aneurysm and Literature Review

Both craniotomy and interventional embolization are difficult and risky to treat complex middle cerebral artery (MCA) aneurysms in infants. Trapping with revascularization is a therapeutic option for giant aneurysms that cannot be clipped or coiled alone. We describe a technical method using revascularization with a natural Y-shaped palmar common digital artery interposition graft that provides a normal variation for a complex MCA aneurysm in an infant with intracerebral hemorrhage at 37 days of age. Conservative treatment was performed at that time. Seven months later, the patient was re-admitted to the hospital and was confirmed a large aneurysm in the M2 segment of the right MCA by cerebral angiography. A natural artery palmar common digital artery Y-graft was used as the graft and anastomosed to the M2 and both M3 trunks. The symptoms improved after surgery, and the mRS score of the patient was 1 after 5 years of follow-up. The palmar common digital artery can be an option for intracranial revascularization bypass in complex intracranial aneurysms.

Flow diverter devices in the treatment of complex middle cerebral artery aneurysms when surgical and endovascular treatments are challenging

ObjectiveIn this study, the authors retrospectively evaluated the effectiveness and the safety of non-surgical middle cerebral artery (MCA) aneurysms treated via the implantation of a flow diverter device (FDD). MethodsClinical, procedural and follow-up data were analyzed in order to evaluate the safety and effectiveness of the treatment with the FDD in complex MCA aneurysms. Safety was assessed recording (intra-procedural, peri-procedural and delayed) complications in order to determine the morbidity and mortality rates. Functional outcome was evaluated with modified Rankin Scale (mRS) prior and after the endovascular procedure. To assess the efficacy, midterm and long-term clinical, angiographic and cross-sectional imaging follow-ups were recorded. Results47 patients (21 males; 26 females) with MCA aneurysms were treated with FDD. 7 were ruptured. 21 aneurysms were saccular, 19 dissecting, 3 fusiform, 2 blood blister-like and 2 were pseudo-aneurysms. 14 aneurysms were small, 23 large and 10 giant, with a mean size of 15.3 mm. 8 aneurysms were recurrent (Raymond-Roy class III): 2 patients had an aneurysmal sac recanalization after being treated with simple coiling and 6 after being treated with microsurgical clipping. In 4 cases (8.5%), more than one FDD was telescopically positioned in order to treat the aneurysm, for a total of 54 FDDs used.The overall mortality rate was 2.1% (1/47) and the overall morbidity rate was 8.6% (4/47). Midterm neuroimaging follow-ups showed the complete occlusion of the aneurysm in 63% cases, which became 91% at the end of the follow-up. ConclusionsFDD is a safe and effective tool that can be used in the treatment of complex MCA aneurysms, where conventional neurosurgical treatments can be challenging or ineffective.

Staged Hybrid Techniques With Straightforward Bypass Surgery Followed by Flow Diverter Deployment for Complex Recurrent Middle Cerebral Artery Aneurysms.

BackgroundRecurrent complex middle cerebral artery (MCA) aneurysms after combined clipping and endovascular surgery are challenging, and if conventional techniques are adapted, advanced surgical, endovascular, and a combination of both techniques are often required. For such complex aneurysms, safe and effective straightforward techniques for all neurovascular surgeons are warranted. We describe the details of staged hybrid techniques with straightforward bypass surgery followed by flow diverter deployment in a patient with complex MCA aneurysm.Illustrative CaseA 69-year-old woman presented with left recurrent large MCA aneurysm enlargement 25 years after direct surgery and coil embolization for ruptured aneurysm. The recurrent MCA aneurysm had large and complex morphology and was adhering to the brain tissues. Therefore, it was unsuitable to treat such aneurysm with conventional surgical and endovascular techniques with a high risk of morbidity. We performed (1) M2 ligation following superficial temporal artery-M2 bypass and (2) flow diverter deployment assisted with coil packing in two sessions. Three months after the second session, the aneurysm was completely occluded with endothelialization of the neck. Angiographic findings revealed no recurrence 12 months after the treatment.ConclusionsStaged hybrid techniques with straightforward bypass surgery followed by flow diverter deployment may be a safe and effective treatment for complex recurrent MCA aneurysms.

Extracranial-intracranial bypass in a neonate with multiple ruptured middle cerebral artery aneurysms: illustrative case

BACKGROUNDReports of ruptured neonatal aneurysms are rare in neurosurgical literature. Pediatric aneurysms differ from adult aneurysms, notably in morphology, size, number, and risk of rerupture. Many authors report experience with clipping, citing durability and decreased use of radiation as benefits over endovascular intervention. Few authors report extracranial-to-intracranial bypass because small pediatric vessels make this option challenging. The authors discussed a case of a newborn with multiple ruptured aneurysms, one of the youngest reported cases involving extracranial-intracranial bypass.OBSERVATIONSA 3-week-old baby presented with hemorrhage from multiple complex middle cerebral artery (MCA) aneurysms. Because of young age, endovascular intervention was not possible; therefore, the patient received craniotomy. Upon exploration, clip reconstruction was impossible; the vessel was trapped, and superficial temporal artery (STA)-MCA bypass was performed. The recipient vessel diameter was 0.3 mm. The postoperative course was complicated by seizures as well as symptomatic vasospasm, which was treated with intraarterial verapamil and ventriculostomy. At last follow-up, the patient was developing normally and was ambulatory with minimal deficit.LESSONSThis case, one of the youngest patients reported, highlighted details of pediatric aneurysm management, such as propensity for multiple/fusiform aneurysms and high risk of re-hemorrhage, with significant mortality. The authors recommended aggressive, early intervention in pediatric aneurysms at centers with surgeons familiar with both endovascular intervention and cerebral bypass.

Intravascular hypothermia for cerebral ischemia after microsurgical clipping of complex MCA aneurysms

To analyze the effectiveness of intravascular hypothermia in patients with ischemic cerebrovascular accidents in early postoperative period after microsurgical clipping of complex MCA aneurysms. We present four patients with cerebral ischemia after microsurgical treatment of complex MCA aneurysms. In all cases, ischemic disorders developed immediately after surgery. We induced intravascular hypothermia 32-34 °C in all patients. CT-based volumetry of ischemia and edema foci was performed to objectively assess the dynamics of ischemic disorders. We carried out volumetry using segmentation of edema and ischemia foci (range 5-33 Hounsfield units). According to brain CT data, all four patients had enlargement of postoperative ischemic brain damage. Nevertheless, ICP was stable that made it possible to avoid decompressive craniotomy. Early hypothermia for acute ischemic injury after surgery for complex MCA aneurysms can reduce ischemic perifocal edema. This approach effectively reduces ICP and can exclude the need for decompressive craniotomy in some cases. No side effects of hypothermia justifies further research in this field.

Microsurgical management of complex middle cerebral artery aneurysms

Introduction Management of complex aneurysms of the middle cerebral artery (MCA) is very challenging and require individualized treatment strategies. The aim of our review was to analyze experience with the treatment of complex MCA aneurysms using revascularization and artery sacrifice techniques. Methods We have reviewed 9 original articles on patients' treatment with complex MCA aneurysms. Depending on localization of complex aneurysm of MCA various methods of parent artery sacrifice, revascularization strategies, surgical results, outcomes and complications were reviewed. Results We have analyzed treatment of 244 patients with 246 complex MCA aneurysms in 9 different groups. From 67 to 100% of cases the aneurysms were occluded successfully. Bypass patency being a result of the performed revascularization methods was from 83.3 to 100%. The main complications included ischemic disorders related to occlusion of the bypass graft or perforators injury. Morbidity in some reviews varied from 2.4 to 6.9%. The majority of patients in late follow-up showed good outcomes 0-2 on modified Rankin scale and 4-5 on Glasgow Outcome Scale. Illustrative clinical cases of the patients with complex MCA aneurysms treated at the Federal Neurosurgical Center were presented. Conclusion Complex aneurysms of the MCA are very challenging lesions. The surgical strategy for treating complex MCA aneurysm should take into account vascular anatomy, complex aneurysm morphology, its localization and rupture status of each case

M2 plane rotation technique for approaching M2 perpendicularly to obliterate aneurysms with interlocking clipping: Technical case report

IntroductionThe interlocking tandem clipping technique allows a surgeon to effectively obliterate the morphologically complex middle cerebral artery aneurysm. However, applying clips perpendicular to the M2 plane is sometimes challenging, even after meticulous arterial dissection and wide dissection of the Sylvian fissure. We present herein a surgical case of a middle cerebral artery aneurysm, and demonstrate a feasible method by which to rotate the M2 plane and apply the clip perpendicular to the M2 plane. Case illustrationA 44-year-old woman presenting with severe headache was admitted to our hospital. Cerebral digital subtraction angiography showed a small saccular aneurysm arising from the left M2 bifurcation. Due to aneurysm neck overhang of the posterior aspect of the bifurcation, the base of the aneurysm was likely to remain following simple parallel clipping of the efferent artery. Therefore, an interlocking tandem clipping technique was considered. Clip application was needed perpendicular to the M2 plane, but the M2 plane was not perpendicular in the line of sight, even after meticulous arterial dissection. We pushed the superior division of the middle cerebral artery inferiorly and pulled the artery medially using an aspiration tube, which allowed the M2 plane to be rotated medially. This allowed application of both a straight mini-clip and an angled fenestrated mini-clip perpendicular to the M2 plane, resulting in successful aneurysm obliteration without a remnant. ConclusionThe presented feasible method allows easy rotation of the M2 plane and application of the clip perpendicular to the M2 plane.

Cerebral revascularization for the management of complex middle cerebral artery aneurysm: A case series.

Complex middle cerebral artery (MCA) aneurysms, including aneurysms that are sizeable (large or giant), fusiform, wide-necked or calcified, remain a significant challenge during microsurgical clipping or endovascular coiling as treatment strategies. In the present study, a retrospective analysis of cases of this type of aneurysm treated between August 2012 and December 2019 was performed. From the hospital's database, a total of 13 patients (7 males and 6 females) with a mean age of 39.0 years (range, 13-65 years) were identified. The mean size of the aneurysms was 17.5 mm (range, 3.9-35.0 mm). A total of four patients (30.8%) had ruptured aneurysms and nine (69.2%) had unruptured aneurysms. All aneurysms were treated by proximal occlusion of the parent artery, trapping or excision combined with cerebral revascularization. The bypasses performed included 10 extracranial-intracranial bypasses and 3 intracranial-intracranial bypasses (1 end-to-end re-anastomosis, 1 interpositional graft and 1 end-to-side reimplantation). Postoperative angiography confirmed that the bypass patency was 92.3% and the clinical outcomes were indicated to be favorable, with a modified Rankin Scale score ≤2 in 12 out of 13 patients (92.3%) at the last follow-up. Taken together, the results of the present analysis suggested that treatment strategies for complex MCA aneurysms should depend on the status and characteristics of the aneurysm, including aneurysm size, location and morphology. For aneurysms that lack perforating arteries in the aneurysm dome, clip trapping or aneurysm excision with or without bypass are preferred as treatment strategies. When there are perforating arteries (particularly the lenticulostriate artery) arising from the aneurysm dome, however, the aneurysms should be treated with bypass followed by proximal occlusion of the parent artery or clip reconstruction.

Surgical Management of Complex Middle Cerebral Artery Aneurysms: An Institutional Review.

Background:Complex middle cerebral artery (MCA) aneurysms are defined as large (≥10 mm) or giant (≥25 mm) aneurysms with M2 branches arising from the aneurysm rather than M1 segments and usually require some form of reconstruction of the bifurcation. Their management is difficult and surgery is preferred over endovascular modalities because of their peculiar angioarchitecture and association with critical branch points or perforators.Objectives:The study was aimed at analyzing surgically managed complex MCA aneurysms and discussing characteristics not favorable for endovascular management, surgical nuances and clipping strategies, patient outcomes, and newer diagnostic modalities which help improve management.Methods:Nine cases of surgically operated complex MCA aneurysms were identified from January 2017 to July 2019. The aneurysm characteristics, surgical nuances, clipping strategies, patient outcomes and points not favoring endovascular management were tabulated and analyzed.Results:The mean maximum aneurysm diameter was 13.4 mm and the mean fundus/neck ratio was 1.6. The average microscope time was 124 min, and the most common method was clip reconstruction. The average number of clips used was 2.7 and the mean follow-up was 13 months. All patients have good postoperative outcome (Modified Rankin Score 0-2). The complete occlusion rate was 88.9% with one intraoperative voluntary residual sac which was coated. Computational fluid dynamic study results done preoperatively correlated with intraoperative findings.Conclusions:MCA aneurysms pose a significant challenge for endovascular treatment because of various factors such as luminal thrombi, complex angio-architecture, precarious branch/perforator locations, broad necks, and fusiform characteristics. Surgical management in experienced hands can tackle all these problems with an armamentarium of clipping techniques and bypass procedures.

Endovascular treatment of complex middle cerebral artery aneurysms using TuBridge flow diverters.

The safety and efficacy of the TuBridge flow diverter in treating middle cerebral artery aneurysms remains unknown. In this study, we report our preliminary experience treating complex middle cerebral artery aneurysms using the TuBridge flow diverter. A prospectively maintained database of intracranial aneurysms treated with the TuBridge flow diverter was retrospectively reviewed, and patients with middle cerebral artery aneurysms were included in this study. Demographics, aneurysm features, complications, and clinical and angiographic outcomes were assessed. Evaluation of the angiographic results included occlusion grade of aneurysm (O'Kelly-Marotta grading scale), patency of jailed branch(es), and in-stent stenosis. Eight patients with eight middle cerebral artery aneurysms were included in this study. The mean aneurysm size was 11.8 ± 6.8 mm. There were no procedure-related complications and there was no morbidity or mortality at a mean follow-up of 11.3 ± 3.6 months. All patients had follow-up angiograms at a mean of 7.5 ± 4.0 months after surgery. Of the eight patients, there was 1 (12.5%) O'Kelly-Marotta grading scale A, 3 (37.5%) O'Kelly-Marotta grading scale B, 1 (12.5%) O'Kelly-Marotta grading scale C, and 3 (37.5%) O'Kelly-Marotta grading scale D. Of the seven patients with jailed branch, the blood flow of jailed branch was unchanged in 4 (57.1%), decreased in 2 (28.6%), and occluded in 1 (14.3%). In-stent stenosis was mild in 2 (25%) patients and moderate in 1 (12.5%) patient. Midterm results suggest that endovascular treatment of middle cerebral artery aneurysms using the TuBridge flow diverter is safe and associated with good outcomes. The TuBridge flow diverter may be an option for complex middle cerebral artery aneurysms that are difficult to treat with either clipping or coiling.

Natural Y-shaped radial artery graft bypass for a complex middle cerebral artery aneurysm: A case report

Giant thrombosed middle cerebral artery (MCA) aneurysms are difficult to treat and sometimes require complex revascularization using allografts. We describe a technical method using revascularization with a natural Y-shaped graft that provides a normal variation for a complex MCA aneurysm. A 65-year-old man with a giant thrombosed MCA aneurysm presented with right hemiparesis and aphasia. The patient had a history of clipping surgery for the ipsilateral side of the MCA aneurysm 25 years before, and a de novo aneurysm developed over the previous 18 years. For the giant thrombosed aneurysm, trapping and revascularization were performed. A natural radial artery Y-graft was used as the graft and anastomosed to both M2 trunks. The symptoms improved after surgery, and the patient was discharged 3 weeks later. This is the first report of a double-barrel bypass using a natural Y-graft. This method attained a normal variation, and the flow of the Y-graft was physiological. For the radical cure of giant thrombosed MCA aneurysms, multiple revascularizations might be required. With this natural Y-graft, complex transpositions could be avoided.

Commentary: Combined Internal Maxillary Artery to Middle Cerebral Artery and In Situ Middle Cerebral to Middle Cerebral Artery Bypass for Complex Middle Cerebral Artery Aneurysm: 3-Dimensional Operative Video.

Division of Neurosurgery, SBH Health System, Bronx, New York Albert Einstein College of Medicine, Bronx, New York CUNY School of Medicine, New York, New York Correspondence: Ralph Rahme, MD, Division of Neurosurgery, SBH Health System, 4422 Third Ave, Bronx, NY 10457. Email: [email protected]sbhny.org

Commentary: Orbitozygomatic Craniotomy for Clipping a Complex Middle Cerebral Artery Aneurysm: 2-Dimensional Operative Video.

Commentary: Orbitozygomatic Craniotomy for Clipping a Complex Middle Cerebral Artery Aneurysm: 2-Dimensional Operative Video.

Bypass surgery of complex middle cerebral artery aneurysms-technical aspects and outcomes.

The main challenge of bypass surgery of complex MCA aneurysm is not the selection of the bypass type, but the initial decision making of how to exclude the affected vessel segment from circulation. The aim of our study was to review our experience with the treatment of complex MCA aneurysms using revascularization and parent artery sacrifice techniques. Based on this, we aimed at categorizing these aneurysms according to specific surgical aspects in order to facilitate preoperative planning for these challenging surgical pathologies. We reviewed 50 patients with complex MCA aneurysms that were not clippable but required revascularization and parent artery sacrifice. We report the individual variations of surgical techniques, highlight the technical aspects, and categorize the aneurysms based on their location and orientation. Of the 50 aneurysms, 56% were giant, 16% large, and 28% < 10mm, but fusiform. Fourteen percent were previously treated endovascular. Four percent presented with SAH. Ten percent were prebifurcational, 60% involved the bifurcation, and 30% were postbifurcational. Both parent artery sacrifice and bypass strategies were tailored to the individual localization and anatomical relationship of the aneurysm and inflow/outflow arteries (38% proximal inflow occlusion, 42% aneurysm trapping, 20% distal outflow occlusion; 14% STA-MCA bypass, 48% interposition graft, 36%, combined/complex revascularization with reimplantation/in situ techniques). Good outcome (mRS 0-2) rates at discharge and at follow-up were 64% and 84%. Based on our analysis of individual cases, we categorized complex MCA aneurysms into six types and provide individual recommendations for their surgical exploration and treatment by revascularization and parent artery sacrifice. Complex MCA aneurysms are among the most challenging vascular lesions and afford highly individualized treatment strategies. Revascularization and parent artery sacrifice provide durable results that are superior to the natural history. Our classification provides a tool for planning and pre-surgical assessment of the intraoperative anatomy of complex MCA aneurysms, helping to assume possible pitfalls.

Surgical Clipping for Complex Middle Cerebral Artery Aneurysm: Decision-Making Tree With Tailored Bypass Strategy

Abstract INTRODUCTION Bypass surgery is important as an effective strategy for complex middle cerebral artery (MCA) aneurysms. Various bypass techniques were reported, but some of them were challenging and difficult to understand. The aim of this report was to propose our simple and flexible method for selecting ideal bypass option and its outcome. METHODS The strategy of bypass surgery is modified by a consideration of the anatomical situation as follows: Is it possible to make a flow our route? Is the amount of bypass flow sufficient? How is the location of lateral lenticulostriate artery (LSA)? Is the preservation of M2 branches possible? Modality of bypass surgery consists of (1) standard superficial temporal artery (STA)-middle cerebral artery (MCA) bypass (single/double, M3/4), (2) STA-proximal MCA (single/double, M1/2), (3) high flow bypass, (4) in-situ bypass (MCA-MCA parallels), and (4) interposition bypass. Operative strategy is selected based on our decision making tree. RESULTS Between 2015 and 2018, we experienced 280 cases (70 ruptured, 210 unruptured) of direct surgery for cerebral aneurysms. Of these cases, the MCA aneurysm accounted for 40% (112 cases). Among these, revascularization was required in 10 cases of complex anatomy. Strategy of bypass surgery included the following: STA-proximal MCA (M1) single bypass: 1 case, STA-proximal MCA (M2) single bypass: 3 cases, STA-proximal MCA (M2) double bypass: 3 cases, STA-distal MCA (M3-4): 1 case, and MCA-MCA in situ bypass: 2 cases (include combination bypass). Patency of bypass was 96% and neurological worsening that caused by surgery was 20% with no operative mortality. CONCLUSION Our decision-making tree with tailored bypass strategy is reasonable and will help select an optimal strategy for the complex MCA aneurysm surgery.