Direct V3 Vertebral Artery Access for Embolization of Partially Thrombosed Fusiform Basilar Trunk Aneurysm: Technical Case Instruction

BACKGROUND AND IMPORTANCE

Fusiform vertebrobasilar aneurysms carry significant morbidity. Endovascular strategies are preferred; however, unsafe or unfeasible access can call for innovative strategies.

CLINICAL PRESENTATION

An octogenarian patient with an enlarging fusiform proximal basilar artery aneurysm causing a sixth nerve palsy was found to have multiple anatomic features that precluded a transradial or transfemoral endovascular approach. She was thus treated with direct microsurgical access of the V3 segment of the vertebral artery for subsequent coil embolization and flow diversion.

CONCLUSION

This case introduces a novel combined microsurgical and endovascular strategy for treating a complex partially thrombosed fusiform basilar artery aneurysm. This approach should be reserved only for patients where conventional endovascular access is dangerous or unfeasible.

Open Surgical Treatment of Middle Cerebral Artery Aneurysms: A Single-Center Series in the Endovascular Era

OBJECTIVE

We review the outcomes of open surgical treatment of middle cerebral artery aneurysms (MCAAs) at a single center, focusing on aneurysm obliteration rates and functional outcomes at the most recent follow-up. These findings can be used for future comparisons of surgical outcomes with MCAAs.

METHODS

We retrospectively reviewed cases from a prospectively maintained database of patients receiving open surgical treatment for ruptured or unruptured MCAAs between July 2014 and December 2022. We utilized patients' modified Rankin Scale (mRS) score and Glasgow Outcome Scale score as functional outcome measures. Means, standard deviations, medians, and interquartile ranges were calculated, and a student's t test or its nonparametric equivalent was used to compare subgroups.

RESULTS

One hundred fifty patients (114 women, 76%; mean age 55.0 ± 14.7 years) with a total of 156 MCAAs comprised 152 cases; 85 (56%) ruptured and 71 (46%) unruptured. Bypass was performed in 34 cases (22.4%); 18 ruptured (51.4%) and 16 unruptured (48.6%). Intraoperative rupture occurred in 5 (5%) ruptured and 1 (2%) unruptured cases. Onwe hundred forty-five patients (95.4%) had aneurysm obliteration with initial surgery, with 98.4% of patients having complete occlusion at 40.2± 65.5 weeks of follow-up. Intrahospital mortality occurred in 7 (6.9%) ruptured versus 1 (2.0%) unruptured case. Fifty-two (51.5%) of the ruptured compared to 43 (86%) unruptured patients were discharged home, with the remaining patients requiring inpatient rehabilitation or long-term hospitalization. The ruptured group had a mean hospital stay of 18.4 ± 10.5 days versus. 5.7 ± 6.0 days for unruptured. Length of stay, discharge mRS/ Glasgow Outcome Scale, and mRS at 4-6 weeks favored unruptured cases (P < 0.0001-0.0336). Mean change in mRS from presentation to last follow-up favored ruptured cases (-0.7 ± 1.2 vs. -0.04 ± 1.2, P = 0.0215).

CONCLUSIONS

Open surgery remains a safe and definitive treatment option for MCAAs in the endovascular era.

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

BACKGROUND AND OBJECTIVE

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.

METHODS

Retrospective review of perioperative data and outcomes for patients undergoing multiterritory cerebral revascularization using a 3-vessel anastomosis from 2019 to 2023.

RESULTS

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.

CONCLUSION

The 3-vessel anastomosis technique can be considered for simultaneous revascularization of multiple intracranial territories.

Neurotropism of SARS-CoV-2: A Pathological Examination of Neurosurgical Specimens

BACKGROUND AND OBJECTIVES

Neurological manifestations may occur in more than 80% of patients hospitalized with COVID-19 infection, including severe disruptions of the central nervous system (CNS), such as strokes, encephalitis, or seizures. Although the primary pathophysiological mechanism for the effects of COVID-19 in CNS remains unknown, evidence exists for both direct injury from neuroinvasion and indirect effects from disruptions in systemic inflammatory and coagulation pathways. In this study, we analyzed CNS tissue from living patients to better understand these processes.

METHODS

With institutional review board approval and patient consent, samples that would be otherwise discarded from patients with active or recent (within 6 days of surgery) COVID-19 infection undergoing neurosurgical intervention were collected and tested for the presence of SARS-CoV-2 using immunohistochemistry, in situ hybridization, electron microscopy, and reverse transcription polymerase chain reaction.

RESULTS

Five patients with perioperative mild-to-moderate COVID-19 infection met inclusion criteria (2 male, 3 female; mean age 38.8 ± 13.5 years). Neurosurgical diagnoses included a glioblastoma, a ruptured arteriovenous malformation, a ruptured posterior inferior cerebellar artery aneurysm, a middle cerebral artery occlusion, and a hemorrhagic pontine cavernous malformation. Samples analyzed included the frontal lobe cortex, olfactory nerve, arteriovenous malformation/temporal lobe parenchyma, middle cerebral artery, cerebellum, and cavernous malformation/brainstem parenchyma. Testing for the presence of SARS-CoV-2 was negative in all samples.

CONCLUSION

The CNS is likely not a significant viral reservoir during mild-to-moderate COVID-19 infection, although direct neuroinvasion is not definitively excluded. Additional testing to help elucidate the relative contributions of direct and indirect pathways for CNS injury from COVID is warranted.

Cilostazol for the management of moyamoya disease: a systematic review of the early evidence, efficacy, safety, and future directions

Surgical revascularization remains the standard treatment for symptomatic moyamoya disease (MMD). As with any major surgical treatment, revascularization is associated with risks and limitations, denoting the need for noninvasive treatments to improve ischemic symptoms and prevent strokes. Cilostazol is a selective phosphodiesterase III inhibitor with antiplatelet, antithrombotic, and vasodilatory effects commonly used in peripheral vascular disease. Clinical studies assessing the efficacy of cilostazol in the management of stroke and MMD were recently reported, although a comprehensive assessment of the overall evidence is lacking. A systematic scoping review was conducted to assess the early evidence on cilostazol administration in patients with MMD. The inclusion criteria encompassed original human studies primarily focused on cilostazol's safety, efficacy, or utilization in managing MMD patients. A search of the PubMed database was conducted in June 2023, yielding 5 peer-reviewed publications that satisfied the inclusion criteria and were subjected to narrative synthesis. Risk of bias assessment was not applicable due to the scoping nature of this review. East Asian studies demonstrate increasing rates of cilostazol prescriptions for patients with MMD. In a large population-based study, cilostazol was compared to other antiplatelet medications and yielded the largest decrease in mortality among patients with newly diagnosed MMD. Other studies reported significant improvements in cerebral blood flow and cognitive function, which were deemed to be independent of one another. There are limited data on the safety profile of cilostazol in the MMD population, although the evidence derived from various studies performed in the general stroke population can likely provide insights into its potential utility in MMD patients. Cilostazol targets several critical pathways involved in the pathophysiology of MMD. The evidence corroborates the potential benefits of cilostazol for the management of MMD, although these findings should be interpreted with caution due to the small number of studies and lack of randomized trials. Subgroups of patients need to be identified who can safely undergo medical management in lieu of revascularization surgery or to improve surgical outcomes. Additional studies are needed to assess the efficacy and safety of cilostazol therapy, especially in Western populations.

A window to the brain: ultrasound imaging of human neural activity through a permanent acoustic window

Recording human brain activity is crucial for understanding normal and aberrant brain function. However, available recording methods are either highly invasive or have relatively low sensitivity. Functional ultrasound imaging (fUSI) is an emerging technique that offers sensitive, large-scale, high-resolution neural imaging. However, fUSI cannot be performed through adult human skull. Here, we use a polymeric skull replacement material to create an acoustic window allowing ultrasound to monitor brain activity in fully intact adult humans. We design the window through experiments in phantoms and rodents, then implement it in a participant undergoing reconstructive skull surgery. Subsequently, we demonstrate fully non-invasive mapping and decoding of cortical responses to finger movement, marking the first instance of high-resolution (200 μm) and large-scale (50 mmx38 mm) brain imaging through a permanent acoustic window.

Surgical Outcomes Following Vestibular Schwannoma Resection in Patients over the Age of Sixty-five

Objective  Vestibular schwannoma (VS) are benign, often slow growing neoplasms. Some institutions opt for radiosurgery in symptomatic patients of advanced age versus surgical resection. The aim of the study is to analyze surgical outcomes of VS in patients over the age of 65 who were either not candidates for or refused radiosurgery. Methods  This includes retrospective analysis of VS patients between 1988 and 2020. Demographics, tumor characteristics, surgical records, and clinical outcomes were recorded. Patient preference for surgery over radiosurgery was recorded in the event that patients were offered both. Facial nerve outcomes were quantified using House-Brackmann (HB) scores. Tumor growth was defined by increase in size of >2 mm. Results  In total, 64 patients were included of average age 72.4 years (65-84 years). Average maximum tumor diameter was 29 mm (13-55 mm). Forty-five patients were offered surgery or GKRS, and chose surgery commonly due to radiation aversion (48.4%). Gross total resection was achieved in 39.1% ( n  = 25), near total 32.8% ( n  = 21), and subtotal 28.1% ( n  = 18). Average hospitalization was 5 days [2-17] with 75% ( n  = 48) discharged home. Postoperative HB scores were good (HB1-2) in 43.8%, moderate (HB3-4) in 32.8%, and poor (HB5-6) in 23.4%. HB scores improved to good in 51.6%, moderate in 31.3%, and remained poor in 17.1%, marking a rate of facial nerve improvement of 10.9%. Tumor control was achieved in 95.3% of cases at an average follow-up time of 37.8 months. Conclusion  VS resection can be safely performed in patients over the age of 65. Advanced age should not preclude a symptomatic VS patient from being considered for surgical resection.

A Novel Bypass Technique to Prevent Vexing Spinal Cord Ischemia in Endovascular Thoracoabdominal Aortic Intervention

BACKGROUND

Spinal cord ischemia remains a devastating complication when treating patients with complex thoracoabdominal aortic aneurysms using fenestrated endovascular aortic repair. This approach is progressively deployed. However, to date, no strategy has been identified to reduce the feared risk of spinal cord ischemia.

OBJECTIVE

To introduce a novel bypass technique using a customized composite graft to create a direct extra-anatomic revascularization before fenestrated endovascular aortic repair in patients with high-risk of spinal cord ischemia.

METHODS

To demonstrate this novel concept, we present here a clinical case that reports the strategy of this novel concept in detail. An 83-year-old man with medical history of endovascular repair of an abdominal aortic aneurysm and thoracic aorta presented with a type IA endoleak, located along the posterior superior aspect of the aortic stent graft adjacent to the lumbar arteries. A multidisciplinary plan was developed, which included a novel bypass from the profunda femoris to the left L1 radicular artery before fenestrated endovascular aortic repair to prevent spinal cord ischemia.

RESULTS

The patient successfully receives the novel extra-anatomic revascularization bypass before fenestrated endovascular aortic repair. During the first implementation of this strategy, no intraoperative difficulties and postoperative complications were observed.

CONCLUSION

This case demonstrates a novel surgical technique before fenestrated endovascular aortic repair for prevention of spinal cord ischemia. In addition, this concept provides a promising direction to not only complement the existing surgical techniques but also to generate more future innovations.

Combined open revascularization and endovascular treatment of complex intracranial aneurysms: case series

Background and purpose

The treatment of complex intracranial aneurysms can be challenging with stand-alone open or endovascular techniques, particularly after rupture. A combined open and endovascular strategy can potentially limit the risk of extensive dissections with open-only techniques, and allow for aggressive definitive endovascular treatments with minimized downstream ischemic risk.

Materials and methods

Retrospective, single-institution review of consecutive patients undergoing combined open revascularization and endovascular embolization/occlusion for complex intracranial aneurysms from 1/2016 to 6/2022.

Results

Ten patients (4 male [40%]; mean age 51.9 ± 8.7 years) underwent combined open revascularization and endovascular treatment of intracranial aneurysms. The majority of aneurysms, 9/10 (90%), were ruptured and 8/10 (80%) were fusiform in morphology. Aneurysms of the posterior circulation represented 8/10 (80%) of the cases (vertebral artery [VA] involving the posterior inferior cerebellar artery [PICA] origin, proximal PICA or anterior inferior cerebellar artery/PICA complex, or proximal posterior cerebral artery). Revascularization strategies included intracranial-to-intracranial (IC-IC; 7/10 [70%]) and extracranial-to-intracranial (EC-IC; 3/10 [30%]) constructs, with 100% postoperative patency. Initial endovascular procedures (consisting of aneurysm/vessel sacrifice in 9/10 patients) were performed early after surgery (0.7 ± 1.5 days). In one patient, secondary endovascular vessel sacrifice was performed after an initial sub-occlusive embolization. Treatment related strokes were diagnosed in 3/10 patients (30%), largely from involved or nearby perforators. All bypasses with follow-up were patent (median 14.0, range 4-72 months). Good outcomes (defined as a Glasgow Outcomes Scale ≥4 and modified Rankin Scale ≤2) occurred in 6/10 patients (60%).

Conclusion

A variety of complex aneurysms not amenable to stand-alone open or endovascular techniques can be successfully treated with combined open and endovascular approaches. Recognition and preservation of perforators is critical to treatment success.

A Review of Medical and Surgical Options for the Treatment of Facial Pain

Facial pain is a common medical complaint that is easily misdiagnosed. As a result, this pain often goes mistreated. Despite this, there are a variety of pharmacologic, surgical, and neuromodulatory options for the treatment of facial pain. In this review, the authors detail the forms of facial pain and their treatment options. They discuss the common medications used in the first-line treatment of facial pain and the second-line surgical and neuromodulatory options available to patients when pharmacologic options fail.

Altered adult neurogenesis and gliogenesis in patients with mesial temporal lobe epilepsy

The hippocampus is the most common seizure focus in people. In the hippocampus, aberrant neurogenesis plays a critical role in the initiation and progression of epilepsy in rodent models, but it is unknown whether this also holds true in humans. To address this question, we used immunofluorescence on control healthy hippocampus and surgical resections from mesial temporal lobe epilepsy (MTLE), plus neural stem-cell cultures and multi-electrode recordings of ex vivo hippocampal slices. We found that a longer duration of epilepsy is associated with a sharp decline in neuronal production and persistent numbers in astrogenesis. Further, immature neurons in MTLE are mostly inactive, and are not observed in cases with local epileptiform-like activity. However, immature astroglia are present in every MTLE case and their location and activity are dependent on epileptiform-like activity. Immature astroglia, rather than newborn neurons, therefore represent a potential target to continually modulate adult human neuronal hyperactivity.

External Carotid Artery-to-Middle Cerebral Artery Bypass Using a Saphenous Vein Graft With 3-Vessel Anastomosis for the Treatment of a Large, Ruptured Middle Cerebral Artery Aneurysm: 2-Dimensional Operative Video

Cerebral revascularization is the treatment of choice for select complex intracranial aneurysms unamenable to traditional approaches.1 Complex middle cerebral artery (MCA) bifurcation aneurysms can include the origins of 1 or both M2 branches and may benefit from a revascularization strategy.2,3 A novel 3-vessel anastomosis technique combining side-to-side and end-to-side anastomoses, allowing for bihemispheric anterior cerebral artery revascularization, was recently reported.4 This 2-dimensional operative video presents the case of a 73-yr-old woman who presented as a Hunt-Hess grade 4 subarachnoid hemorrhage due to the rupture of a large right MCA bifurcation aneurysm. The aneurysm incorporated the origins of the frontal and temporal M2 branches and was deemed unfavorable for endovascular treatment. A strategy using a high-flow bypass from the external carotid artery to the MCA with a saphenous vein (SV) graft was planned to revascularize both M2 branches simultaneously, followed by clip-trapping of the aneurysm. Intraoperatively, the back walls of both M2 segments distal to the aneurysm were connected with a standard running suture, and the SV graft was then attached to the side-to-side construct in an end-to-side fashion. Catheter angiograms on postoperative days 1 and 6 demonstrated sustained patency of the anastomosis and good filling through the bypass. The patient's clinical course was complicated by vasospasm-related right MCA territory strokes, resulting in left-sided weakness, which significantly improved upon 3-mo follow-up with no new ischemia. The patient consented for inclusion in a prospective Institutional Review Board (IRB)-approved database from which this IRB-approved retrospective report was created.

Neuroprotective effect of minocycline against acute brain injury in clinical practice: A systematic review

Acute brain injury is a leading cause of morbidity and mortality worldwide. The term is inclusive of traumatic brain injury, cerebral ischemia, subarachnoid hemorrhage, and intracerebral hemorrhage. Current pharmacologic treatments have had minimal effect on improving neurological outcomes leading to a significant interest in the development neuroprotective agents. Minocycline is a second-generation tetracycline with high blood brain barrier penetrance due to its lipophilic properties. It functions across multiple molecular pathways involved in secondary-injury cascades following acute brain injury. Animal model studies suggest that minocycline might lead to improved neurologic outcomes, but few such trials exist in humans. Clinical investigations have been limited to small randomized trials in ischemic stroke patients which have not demonstrated a clear advantage in neurologic outcomes, but also have not been sufficiently powered to draw definitive conclusions. The potential neuroprotective effect of minocycline in the setting of traumatic brain injury, subarachnoid hemorrhage, and intracerebral hemorrhage have all been limited to pilot studies with phase II/III investigations pending. The authors aim to synthesize what is currently known about minocycline as a neuroprotective agent against acute brain injury in humans.

Cerebrovascular bypass for ruptured aneurysms: A case series

In patients with aneurysmal subarachnoid hemorrhage (aSAH) unfavorable for endovascular or traditional open surgical techniques, surgical revascularization strategies comprise one of remaining limited options. There is nonetheless a paucity of data on the safety and efficacy of bypass in aSAH. In this study, we aimed to investigate complications and outcomes in a cohort of patients with aSAH treated with bypass. A prospective single-surgeon database of consecutive patients treated for aSAH between 2013 and 2018 was retrospectively analyzed. Complications and functional status at discharge were recorded and analyzed for the patients that underwent bypass surgery. Forty patients with aSAH were treated with bypass surgery (23 extracranial-intracranial; 17 intracranial-intracranial). All-cause perioperative mortality was 13% (6 patients). At discharge and at mean 14-month follow up, respectively, 16/40 (40%) and 16/25 (64%) of patients achieved a Glasgow Outcome Score of 4-5. All-cause, in-hospital complications occurred in 28 patients (70%), of which any ischemic complication occurred in 20 patients (50%), 7 (18%) being open surgical complications. This work represents the largest modern series of bypass for aSAH to date. In cases of aSAH unfavorable for endovascular intervention or traditional open surgical techniques, bypass remains a viable option in this complex group of patients.

Prospects of Photo- and Thermoacoustic Imaging in Neurosurgery

The evolution of neurosurgery has been, and continues to be, closely associated with innovations in technology. Modern neurosurgery is wed to imaging technology and the future promises even more dependence on anatomic and, perhaps more importantly, functional imaging. The photoacoustic phenomenon was described nearly 140 yr ago; however, biomedical applications for this technology have only recently received significant attention. Light-based photoacoustic and microwave-based thermoacoustic technologies represent novel biomedical imaging modalities with broad application potential within and beyond neurosurgery. These technologies offer excellent imaging resolution while generally considered safer, more portable, versatile, and convenient than current imaging technologies. In this review, we summarize the current state of knowledge regarding photoacoustic and thermoacoustic imaging and their potential impact on the field of neurosurgery.

An Expedited Transition to the Back Wall Suturing for Side-to-Side In Situ Microvascular Anastomosis: A Technique Update

BACKGROUND

The side-to-side in situ microvascular anastomosis is an important tool in the cerebrovascular neurosurgeon's armamentarium. The execution of the side-to-side anastomosis, however, can be limited by the inability to acquire sufficient visualization and approximation of the recipient and donor vessels.

OBJECTIVE

To expedite the transition to the back wall suturing of the donor and recipient vessels during side-to-side in situ microvascular anastomosis.

METHODS

Incorporation of the first suture throw from the outside to the inside of the vessel lumen with the initial stay suture at the proximal apex of the arteriotomy is described. The apical knot is tied between one limb of the resultant loop and the free end of the suture. The remainder of side-to-side anastomosis can then be completed in a standard fashion starting from the inside of the lumen.

RESULTS

This modification allows for an expedited transition to the back wall suturing of the 2 arterial segments and avoids difficulties associated with taking the first bite from behind the knot at the proximal apex of the arteriotomy or the transfer of the needle between the approximated vessels. This updated technique is illustrated with a case example, illustration, and video.

CONCLUSION

This technical modification for the side-to-side anastomosis helps optimize microsurgical efficiency by limiting needle, suture, and vessel handling after the initial suture placement, which has classically been a challenge of this bypass.

Comparative Assessment of Extracranial-to-Intracranial and Intracranial-to-Intracranial In Situ Bypass for Complex Intracranial Aneurysm Treatment Based on Rupture Status: A Case Series

BACKGROUND

Comparative outcomes of extracranial-to-intracranial (EC-IC) and intracranial-to-intracranial (IC-IC) bypass for complex aneurysm treatment based on rupture status are not well described in the literature. In this study, we compare outcomes of EC-IC and IC-IC bypass for complex intracranial aneurysm treatment based on rupture status.

METHODS

A prospective neurosurgical patient database was retrospectively reviewed. Sixty-three consecutive patients with aneurysm managed with revascularization were identified between July 2014 and December 2018.

RESULTS

During the study period, 41 patients with aneurysm underwent EC-IC bypass (65%; 24 [58.5%] ruptured, 17 [41.5%] unruptured) and 22 patients with aneurysm underwent IC-IC bypass (34.9%; 13 [59.1%] ruptured, 9 [40.9%] unruptured). Graft spasm occurred in 4 patients (9.8%) in the EC-IC group (all ruptured aneurysms) and all anastomoses were patent on immediate postoperative imaging. Perioperative mortality occurred in 5 patients who underwent EC-IC bypass (12.2%; 3 ruptured, 2 unruptured) EC-IC and 2 patients who underwent IC-IC bypass (9.1%; both ruptured); (P = 0.709). Bypass-related complications occurred only in patients with ruptured aneurysm (2 [8.3%] in the EC-IC group and 0 [0%] in the IC-IC group; P = 0.285). For unruptured aneurysms, the overall complication rate was lower in IC-IC compared with the EC-IC group (P = 0.006). Modified Rankin Scale scores on discharge were significantly lower in IC-IC compared with EC-IC bypass for unruptured aneurysms (P = 0.008). There was a trend for shorter temporary occlusion and hospitalization times and overall better outcomes with IC-IC compared with EC-IC bypass.

CONCLUSIONS

Although often considered riskier than EC-IC bypass, IC-IC in situ bypass showd a favorable technical and safety profile for the treatment of complex, unruptured aneurysms.

A3-A3 Anastomosis in the Management of Complex Anterior Cerebral Artery Aneurysms: Experience With in Situ Bypass and Lessons Learned From Pseudoaneurysm Cases

BACKGROUND

A3-A3 side-to-side bypass is an intracranial-to-intracranial (IC-IC) revascularization option when aneurysm treatment involves occlusion of one anterior cerebral artery (ACA).

OBJECTIVE

To describe applications of A3-A3 side-to-side bypass in the management of ACA true and pseudoaneurysms along with a review of pertinent literature.

METHODS

Six consecutive patients undergoing an A3-A3 bypass as part of their aneurysm management, representing a single-surgeon experience in a 2-yr period, were included in this retrospective review of a prospectively collected database.

RESULTS

Three male and three female patients with a median (range) age of 41.5 (11-69) years representing four ruptured and two unruptured aneurysms were included. Two of the aneurysms were communicating while four were postcommunicating from which three were pseudoaneurysms. Complete aneurysm obliteration was achieved in 5/6 cases. Bypass patency was evaluated in all cases intra- and postoperatively. Good outcomes (modified Rankin Scale score ≤ 2) at follow-up were observed in 4/6 patients. An improvement in mRS scores at the most recent follow-up as compared to preoperative status was achieved in three while scores remained the same in two patients. Ischemic complications related to aneurysm treatment were observed in two patients, both of which achieved good functional recovery upon follow-up. One patient deceased postoperatively due to progression of vasospasm-related infarcts.

CONCLUSION

A3-A3 bypass in the management of true as well as pseudoaneurysms of the ACA can achieve good postoperative outcomes in selected patients. Prompt diagnosis and aggressive surgical treatment needs to be pursued if a vessel injury with pseudoaneurysm formation is suspected.

Intraoperative Assessment of Cortical Perfusion After Intracranial-To-Intracranial and Extracranial-To-Intracranial Bypass for Complex Cerebral Aneurysms Using Flow 800

BACKGROUND

Revascularization strategies for complex cerebral aneurysms are largely based on subjective interpretation of flow demands, or indirect measures of perfusion in at-risk territories. Indocyanine Green -based flow analyses ((ICG-BFA); Flow 800, Carl Zeiss, Oberkochen, Germany) provide a real-time, semiquantitative measure of intraoperative cortical perfusion during cerebral bypass surgery for complex aneurysms.

OBJECTIVE

To determine the utility of intraoperative ICG-BFA for assessing cortical perfusion in at-risk territories during cerebral bypass for complex aneurysms requiring vessel sacrifice.

METHODS

Retrospective analysis of consecutive patients from a prospective, single-institution open cerebrovascular database.

RESULTS

Intraoperative ICG-BFA confirmed adequate cortical perfusion in 2 patients with fusiform posterior circulation aneurysms, treated with a posterior inferior cerebellar artery (PICA)-PICA and occipital artery (OA)-to-third segment of the posterior cerebral artery (P3) bypass with proximal vessel sacrifice, respectively. ICG-BFA was used in a third patient that underwent clip reconstruction/ intracranial-to-intracranial bypass for a large middle cerebral artery (MCA) bifurcation aneurysm requiring sacrifice of the temporal M2 branch. In this case, a frontal M3 to temporal M3 side-to-side anastomosis was created to arborize the MCA tree and allow filling of both M2 territories through a single M2 branch. After aneurysm reconstruction, ICG-BFA identified an inadvertent occlusion of the frontal M2 that left the entire MCA distribution reliant on collateral flow but did not cause a neuromonitoring change. Repeat ICG-BFA after clip re-arrangement demonstrated aneurysm occlusion and equal flow in both frontal and temporal MCA cortical distributions from the arborization.

CONCLUSION

ICG-BFA is a useful adjunct for intraoperative cortical flow assessment during cerebral revascularization for complex aneurysms requiring vessel sacrifice.

Bypass and Deconstructive Technique for Hunt and Hess Grade 3-5 Aneurysmal Subarachnoid Hemorrhage Deemed Unfavorable for Endovascular Treatment: Case Series of Outcomes and Comparison with Clipping

BACKGROUND

Intracranial bypass to treat ruptured aneurysms has been well described in the literature but is largely deferred in patients with higher Hunt and Hess (H & H) grades due to complexity and length of surgery, risk of inducing vasospasm, and poor prognosis. However, there is a paucity of data and no direct comparison with more traditional open surgical techniques. This study investigated outcomes in patients with H & H grade 3-5 aneurysmal subarachnoid hemorrhage (aSAH) unfavorable for stand-alone endovascular treatment managed with bypass compared with direct surgical clipping.

METHODS

A prospective database of patients treated for aSAH with H & H grade 3-5 between 2013 and 2018 was retrospectively analyzed. Complications and functional status at discharge and latest follow-up were compared between patients who underwent bypass surgery versus direct clipping.

RESULTS

Twenty-three patients underwent revascularization, and 60 underwent clipping alone. There were no significant differences in all-cause 30-day mortality (15% vs. 16%; P = 0.97) or Glasgow Outcome Scale and modified Rankin Scale at discharge or median 8-month follow-up (P > 0.67). There was a higher overall stroke rate with revascularization (P = 0.004), specifically endovascular treatment-related stroke (P = 0.049), with no difference in surgical (P = 0.47) or vasospasm-related stroke (P = 0.53). There were no differences in overall complications, medical complications, seizures, reruptures, hydrocephalus, or perioperative death (P > 0.05).

CONCLUSIONS

Bypass is a viable option for patients presenting with higher H & H grade aSAH deemed unfavorable for stand-alone endovascular therapy. Despite obvious differences in aneurysm complexity and a higher risk of stroke, functional outcomes with revascularization can be comparable with clipping in this high-risk patient cohort.

Transblepharo-Preseptal Modified Orbitozygomatic Approach for Resection of Giant Frontal Cavernous Malformation: 3-Dimensional Operative Video

A previously healthy 44-year-old woman presented with a first-time seizure. Magnetic resonance imaging (MRI) revealed a right frontal intraaxial mass extending from the orbitofrontal gyri and gyrus rectus to the head of the caudate (Video 1). The mass demonstrated heterogeneous signal intensity on precontrast T1-weighted MRI, minimal contrast enhancement, and mixed intensity on gradient echo MRI sequence consistent with a likely cavernous malformation. Given the location above the orbital roof with cranial-caudal extension to the level of the caudate, a transblepharo-preseptal modified orbitozygomatic craniotomy was recommended. With the assistance of plastic surgery, the lesion was approached through an eyelid incision that extended laterally to expose the keyhole. A McCarty burr hole was made, followed by a tailored orbitozygomatic craniotomy with osteotomies extending through the superolateral orbit and greater sphenoid wing to expose the proximal sylvian fissure. Dura was opened in a C-shaped fashion over the periorbital fat to allow for mild downward retraction of the globe, exposing the subfrontal trajectory. The opticocarotid cistern was opened to allow for cerebrospinal fluid egress and relaxation, and the lesion was readily identified through the use of stereotactic neuronavigation and presence of a faint hemosiderin blush within the underlying parenchyma. The standard microsurgical technique was used to perform a gross total resection of the pathologically confirmed cavernous malformation. The orbitozygomatic bone flap was replaced and plated, and the wound was closed in multiple layers. The patient was seen at a 3-month follow-up without further seizures.

Three-Vessel Anastomosis for Direct Bihemispheric Cerebral Revascularization

BACKGROUND

In rare, complex cerebrovascular pathologies, patients may benefit from simultaneous revascularization of multiple arterial territories. Traditional strategies for these situations include the use of more than 1 interposition graft, multiple microvascular anastomoses, vessel reimplantations, and staged procedures.

OBJECTIVE

To improve upon traditional revascularization strategies by describing a novel 3-vessel microvascular anastomosis. This technique combines a side-to-side and an end-to-side anastomoses to facilitate simultaneous direct revascularization of 2 arterial territories in a single procedure, with a single donor vessel.

METHODS

We present an illustrative case of moyamoya angiopathy in which a 3-vessel anastomosis was performed in the interhemispheric fissure to simultaneously directly revascularize bilateral anterior cerebral artery (ACA) territories. A detailed step-by-step depiction of the anastomosis technique is provided. In the presented case, 3-vessel anastomosis was combined with a radial artery fascial flow-through free flap, allowing for an additional indirect revascularization.

RESULTS

Technical execution of the 3-vessel anastomosis was uncomplicated. The patency of the anastomosis providing direct bilateral ACA territory revascularization was demonstrated intra- and postoperatively.

CONCLUSION

With this report, we demonstrate technical feasibility of a novel 3-vessel anastomosis for direct 2 arterial territory revascularization This single-stage approach combines side-to-side and end-to-side techniques and has benefits over traditional revascularization techniques, as it is not deconstructive, requires only a single craniotomy and a single interposition graft, and does not require lengthy recipient artery dissection.

Lessons Learned from the Initial Experience with Pedicled Temporoparietal Fascial Flap for Combined Revascularization In Moyamoya Angiopathy: A Case Series

BACKGROUND

The pedicled temporoparietal fascial flap (TPFF) with a direct superficial temporal (STA) artery to middle cerebral artery (MCA) bypass is a novel combined revascularization approach for moyamoya angiopathy (MMA). With this case series, we aim to report the initial experience with pedicled TPFF combined revascularization for MMA treatment.

METHODS

Data from 14 consecutive patients undergoing pedicled TPFF combined revascularization for MMA between May 2016 and December 2018 were retrospectively reviewed. Patients admitted with acute ischemia or a modified Rankin Scale (mRS) score >3 were considered high risk.

RESULTS

Mean ± standard deviation age on surgery was 41.9 ± 15.4 years. Three of 14 patients (21.4%) presented with an mRS score >3. Nine of 14 patients (64.3%) presented with ischemic stroke, 4 of whom (44.4%) had acute ischemia. Direct anastomosis patency was confirmed in all cases postoperatively. Mean hospitalization time was 13 ± 9.3 days and mean follow-up time was 14.1 ± 9.3 months. From admission to follow-up, neurologic status improved in 8 patients (57.1%) and stabilized in 6 patients (42.9%). Overall, 11/14 patients (78.6%) achieved good functional outcome (mRS score ≤2). All patients achieved some radiographic collateral development, with 5 (71.5%) graded as Matsushima A and B. Three patients developed new radiographic ischemia and 3 experienced wound complications, all in the high-risk group.

CONCLUSIONS

The TPFF combined approach is a viable strategy for revascularization in MMA. This technique may be suboptimal in patients presenting with acute ischemia and/or mRS score >3.

Assessment of ischemic risk following intracranial-to-intracranial and extracranial-to-intracranial bypass for complex aneurysms using intraoperative Indocyanine Green-based flow analysis

Cerebral bypass is often needed for complex aneurysms requiring vessel sacrifice, yet intraoperative predictors of ischemic risk in bypass-dependent territories are limited. Indocyanine Green (ICG)-based flow analyses (ICG-BFAs; Flow 800, Carl Zeiss, Oberkochen, Germany) semi-quantitatively assess cortical perfusion, and in this work we determine the efficacy of ICG-BFA for assessing post-operative ischemic risk during cerebral bypass surgery for complex aneurysms. Retrospective clinical and pre/post-bypass intra-operative ICG-BFA data (delay and blood flow index [BFI]) on ten patients undergoing cerebral bypass for complex cerebral aneurysms requiring vessel sacrifice were collected from a single-institution prospective database and analyzed via non-parametric testing and logistic regression. Mean age was 55.9 ± 14.8 years. Pre/post-bypass delay (median 35.6 [5.1-51.3] vs. 26.0 [17.1-59.9]; p = 0.2) and BFI (median 56.1 [8.1-120.4] vs. 32.2 [3.0-147.4]; p = 0.2) did not significantly differ. Two patients (20%) developed post-operative ischemia in bypass dependent territories. Delay ratio did not differ between patients with and without post-operative ischemia (median 1.15 [0.67-1.64] vs. 0.83 [0.36-3.56]; p = 0.6), nor predict stroke risk (odds ratio = 1.1, p = 0.9). Conversely, BFI ratio was significantly lower for patients experiencing post-operative ischemia than those without ischemia (median 0.11 [0.06-0.17] vs. 0.99 [0.28-1.42]; p = 0.03). A BFI ratio <0.21 predicted the occurrence of post-operative ischemia (odds ratio = 0.02, p = 0.05). These data suggest that intraoperative ICG-BFA may help assess post-operative ischemic risk during cerebral bypass surgery for complex aneurysms requiring vessel sacrifice.

Radial Artery Fascial Flow-Through Free Flap for Complex Cerebral Revascularization: Technical Notes and Long-Term Neurologic and Radiographic Outcomes

BACKGROUND

Surgical innovation is critical for the management of challenging cerebrovascular pathology. Flow-through free flaps are versatile composite grafts that combine viable tissue with a revascularization source. Neurosurgical experience with these flaps is limited.

OBJECTIVE

To provide an in-depth technical description of the radial artery fascial (and fasciocutaneous) flow-through free flap (RAFF and RAFCF, respectively) for complex cerebral revascularizations.

METHODS

An Institutional Review Board-approved, prospective database was retrospectively reviewed to identify patients that underwent extracranial-to-intracranial cerebral bypass with a RAFF or RAFCF. Patient demographics, underlying pathology, surgical treatment, complications, and outcomes were recorded.

RESULTS

A total of 4 patients were treated with RAFFs or RAFCFs (average age 40 ± 8.8 yr). Two patients with progressive moyamoya disease involving multiple vascular territories with predominantly anterior cerebral artery (ACA) symptoms and flow alterations underwent combined direct ACA and indirect middle cerebral artery (MCA) bypass with a RAFF. The third patient with moyamoya disease and concomitant proximal fusiform aneurysms requiring internal carotid artery sacrifice underwent dual direct ACA and MCA bypass and indirect MCA revascularization with posterior tibial artery and RAFF grafts. The fourth patient with a large MCA bifurcation aneurysm and recurrent wound complications underwent a direct MCA bypass and complex wound reconstruction using a RAFCF. Good neurologic outcomes (Glasgow Outcomes Scale score ≥4 at discharge) were achieved in all patients. There were no perioperative surgical complications, and graft patency was confirmed on long-term follow-up.

CONCLUSION

The RAFF and RAFCF are versatile grafts for complex cerebral revascularizations.

Complex Revascularization for Idiopathic Intracranial Occlusive Disease with Unruptured, Fusiform Anterior Cerebral Artery and Middle Cerebral Artery Aneurysms: 3-Dimensional Operative Video

Revascularization is an important strategy when treating cerebrovascular occlusive disease and complex aneurysms. Radial artery fascial flow-through free flaps (RAFFs) are flexible grafts that provide direct and indirect revascularization. RAFFs can be especially useful for large territory revascularization and can be combined with other direct bypasses. Although common in plastic and reconstructive surgery, RAFF neurosurgical applications have rarely been described. The 3-dimensional video presents a 47-year-old man with watershed infarcts on imaging who presented with right-sided weakness (Video 1). Vessel imaging was significant for bilateral internal carotid artery (ICA) terminus stenosis. The left middle cerebral artery (MCA) ended in a fusiform aneurysm of the M1 segment. The left anterior cerebral artery (ACA) also had a smaller fusiform aneurysm at the A1/2 junction. A perfusion study demonstrated an increased mean transit time in the left MCA territory. Given the patient's age, his symptomatic ischemia, and enlarging MCA aneurysm, he was recommended for a combined revascularization and left ICA occlusion. A left facial artery-to-MCA bypass using the right posterior tibial artery was performed for direct MCA revascularization. A left superficial temporal artery-to-ACA bypass with a RAFF was performed for direct ACA and indirect MCA territory revascularization. Postoperative angiography demonstrated patency of both direct grafts. The patient suffered small pericallosal infarcts because of retraction and perforator sacrifice at the revascularization site. At early follow-up, the patient was at his neurologic baseline, and at 1-year follow up, the patient had no additional infarcts on imaging and was living independently.

Extracranial-to-Intracranial Bypass for Refractory Vertebrobasilar Insufficiency

BACKGROUND

Vertebrobasilar insufficiency (VBI) is associated with high rates of morbidity and mortality, especially after failure of first-line medical and/or endovascular therapies. Although the optimal therapeutic strategy for refractory VBI remains unclear, surgical bypass represents a potentially life-saving treatment in this patient subset.

METHODS

A multi-institution retrospective database review was performed to identify patients with symptomatic refractory VBI over a 4-year period (July 2014 to July 2018). Surgical treatments, as well as clinical and neurologic outcomes were recorded.

RESULTS

Five patients were identified with refractory VBI (average age 55 ± 11.0 years). All 5 patients had clinically significant posterior circulation strokes on presentation. Three patients underwent superficial temporal artery-to-superior cerebellar artery bypass based on significant acute perfusion mismatches or progressive strokes despite maximal medical therapy; 1 surgical patient (33%) experienced punctate perioperative strokes and there were no significant bypass related complications. Functional outcomes in the 3 surgical patients were correlated with preoperative stroke burden. The remaining 2 patients experienced rapid neurologic declines after presentation that precluded bypass, and died shortly thereafter.

CONCLUSIONS

Refractory VBI has high morbidity, with cerebral bypass representing a safe and potentially efficacious treatment for selected patients. Long-term post-bypass outcomes are dependent on the level of irreversible preoperative neurologic injuries.

Ruptured Mycotic Aneurysm of the Distal Circulation in a Patient with Mucormycosis Without Direct Skull Base Extension: Case Report

BACKGROUND AND IMPORTANCE

Infectious intracranial aneurysms are a rare subset of intracranial aneurysms caused by bacterial, fungal, or viral sources. Intracranial aneurysms of fungal etiology carry a high mortality risk and typically occur in immunocompromised patients via direct extension of skull base infections, or more rarely, after intracranial surgery.

CLINICAL PRESENTATION

We present the case of a 27-yr-old female with systemic lupus erythematous and primary pulmonary mucormycosis, who suffered a subarachnoid hemorrhage from a ruptured fusiform distal middle cerebral artery aneurysm. Despite undergoing a successful extracranial-to-intracranial bypass and aneurysm excision, the patient ultimately died following progressive disseminated infection and a secondary intracranial hemorrhage of unknown etiology. Pathological examination of the excised artery confirmed Mucor infection.

CONCLUSION

To the best of our knowledge, this case represents one of the first mycotic cerebral aneurysms from mucormycosis in a patient without an underlying skull base infection or previous intracranial surgery. Despite optimal surgical management, clinical outcomes for mycotic cerebral aneurysms are largely dependent on the success of medical therapies at controlling systemic disease.

Intentional Subtotal Resection of Vestibular Schwannoma: A Reexamination

Background  Treatment of vestibular schwannomas (VS) remains controversial. Historical surgical series prioritized gross total resections (GTR); however, near total resections (NTR) and intentional subtotal resections (STR) aiming at improving cranial nerve outcomes are becoming more popular. Objective  The main purpose of this article is to assess the tumor control and facial nerve outcomes in VS patients treated with STR or NTR. Methods  VS patients undergoing STR or NTR at our institution between 1984 and 2016 were retrospectively reviewed. Patient demographics, extent of tumor resection, facial nerve injury, tumor recurrence, and need for Gamma Knife radiosurgery were analyzed. Facial nerve outcomes were quantified using House-Brackmann (HB) scores. Tumor regrowth was defined by the San Francisco criteria. Results  Four-hundred fifty-seven VS resections were performed in a 32-year period. Sixty cases met inclusion criteria. The mean (range) follow-up duration was 30.9 (12-103) months. The STR cohort ( n  = 33) demonstrated regrowth in 12 patients (36.3%) at an average of 23.6 months. The NTR cohort ( n  = 27) did not experience tumor recurrence. Risk of tumor recurrence was positively correlated with preoperative tumor size ( p  = 0.002), size of residual tumor ( p  < 0.001), and STR ( p  < 0.001). Facial nerve outcomes of HB1-2 were observed in the majority of patients in both cohorts (74.1% NTR, 56% STR), though NTR was associated with a higher likelihood of facial nerve recovery ( p  = 0.003). Conclusion  GTR remains the gold standard as long as facial nerve outcomes remain acceptable. NTR achieved superior tumor control and higher likelihood of facial nerve recovery compared with STR.

Role of botulinum neurotoxin-A in cerebral revascularization graft vasospasm prevention: current state of knowledge

Graft stenosis and occlusion remain formidable complications in cerebral revascularization procedures, which can lead to significant morbidity and mortality. Graft vasospasm can result in early postoperative graft stenosis and occlusion and is believed to be at least partially mediated through adrenergic pathways. Despite various published treatment protocols, there is no single effective spasmolytic agent. Multiple factors, including anatomical and physiological variability in revascularization conduits, patient age, and comorbidities, have been associated with graft vasospasm pathogenesis and response to spasmolytics. The ideal spasmolytic agent thus likely needs to target multiple pathways to exert a generalizable therapeutic effect. Botulinum toxin (BTX)-A is a powerful neurotoxin widely used in clinical practice for the treatment of a variety of spastic conditions. Although its commonly described paradigm of cholinergic neural transmission blockade has been widely accepted, evidence for other mechanisms of action including inhibition of adrenergic transmission have been described in animal studies. Recently, the first pilot study demonstrating clinical use of BTX-A for cerebral revascularization graft spasm prevention has been reported. In this review, the mechanistic basis and potential future clinical role of BTX-A in graft vasospasm prevention is discussed.

Pedicled temporoparietal fascial flap for combined revascularization in adult moyamoya disease

Moyamoya disease (MMD) is a progressive, idiopathic cerebrovascular occlusive disease. Various revascularization techniques including direct, indirect, and combined microvascular bypasses have been described. This article presents a modified revascularization technique for MMD utilizing a pedicled temporoparietal fascial flap (TPFF) for combined revascularization. This technique combines a large area of coverage for indirect revascularization with the benefits of a direct bypass. The pedicled TPFF also benefits from intact venous drainage to minimize the risk of flap swelling that could result in complications from mass effect.

Occipital Artery to Posterior Cerebral Artery Bypass Using Descending Branch of the Lateral Circumflex Femoral Artery Graft for Treatment of Fusiform, Unruptured Posterior Cerebral Artery Aneurysm: 3-Dimensional Operative Video

Posterior cerebral artery (PCA) aneurysms can be technically challenging lesions due to the intricacy of perforating branches and the relationship to cranial nerves and the brainstem. Fusiform aneurysms of the perimesencephalic segment of the PCA are a rare finding which does not favor direct clip occlusion or reconstruction. In such cases, proximal parent vessel occlusion is an option for aneurysm treatment. Extracranial-intracranial (EC-IC) bypass can be used to revascularize beyond the lesion when considering proximal occlusion. Based on previous literature for occipital artery (OA) bypass and the time-consuming dissection required for OA harvest, an interposition graft was chosen. The descending branch of the lateral circumflex femoral artery (DLCFA) is a good alternative interposition graft with a diameter that is favorable for revascularizing smaller, more distal vessels.This 3-dimensional video presents the case of a 26-year-old female with severe headaches who was found to have unruptured, fusiform aneurysmal dilatations of the PCA. Given the patient's youth and the morphology of the aneurysms, an EC-IC bypass with proximal occlusion was recommended. The DLCFA was used as an interposition graft. The left OA was found to be a suitable donor. A subtemporal approach was used to access the PCA for proximal occlusion. An occipital interhemispheric approach was performed to isolate a suitable recipient segment of the ipsilateral PCA branch for microvascular end-to-side anastomosis. Postoperative catheter angiography showed significant thrombosis of the fusiform aneurysms and a patent EC-IC bypass. Postoperative magnetic resonance imaging showed no infarcts and the patient was discharged neurologically intact.The patient was consented for inclusion in a prospective institutional review board (IRB) approved database from which this IRB approved retrospective report was performed. The consent for intraoperative video and picture use was also obtained.Images in the video between 0:49 and 1:11, © University of Southern California Neurorestoration Center. Used with permission, all rights reserved.