Complications in AVM Surgery.

In AVM surgery perioperative complications can arise and can have serious perioperative consequences. Surgically related complications in AVM treatment, in many cases, can be avoided by paying attention to details:1. Careful selection of the patient: - addressing a patient with eloquent AVM to Gamma Knife treatment - preoperative treatment with selective embolization of the accessible deep feeders - preoperative gamma knife or embolize those patient with an over-expressed venous pattern2. Meticulous coagulation of deep medullary feeders: - Using dirty coagulation - Using dry non-stick coagulation - Using micro clips - Using laser - Reaching the choroidal vessel in the ventricle when possible - Avoiding occlusive coagulation with hemostatic agents3. Check and avoiding any residual of the AVM4. Keep the patient under pressure control during postoperative periodFulfilling these steps contributes to reduce complications in this difficult surgery, leading to a safer treatment that compares favorably with natural history of brain arteriovenous malformations.

Intracranial Dural Arteriovenous Fistulas: The Sinus and Non-Sinus Concept.

INTRODUCTION: Dural arteriovenous fistulas (dAVFs) account for 10-15% of all intracranial arteriovenous lesions. Different classification strategies have been proposed in the course of the years. None of them seems to guide the treatment strategy. OBJECTIVE: We expose the experience of the vascular group at Niguarda Hospital and we propose a very practical classification method based on the location of the shunt. We divide dAVF in sinus and non-sinus in order to simplify our daily practice, as this classification method is simply based on the involvement of the sinuses. MATERIAL AND METHODS: 477 intracranial dural arteriovenous fistulas have been treated. 376 underwent endovascular treatment and 101 underwent surgical treatment. Cavernous sinus DAVFs and Galen ampulla malformations have been excluded from this series as they represent a different pathology per se. 376 dAVFs treated by endovascular approach: 180 were sinus and 179 were non-sinus. 101 dAVFs treated with surgical approach: 15 were sinus and 86 were non-sinus. DISCUSSION: Of the 477 intracranial dAVF the recorded mortality and severe disability was 3% and morbidity less than 4%. All patients underwent a postoperative DSA with nearly 100% of complete occlusion of the fistula. At a mean follow-up of 5 years in one case there was a non-sinus fistula recurrence, due to the presence of a partial clipping of "piè" of the vein. CONCLUSIONS: The sinus and non-sinus concept has guided our institution for years and has led to good clinical results. This paper intends to share this practical classification with the neurosurgical community.

Spontaneous Subarachnoid Haemorrhage in Spinal Hemangioblastoma: Illustrative Case and Discussion of a Pathophysiological Hypothesis.

Spontaneous non-aneurysmal subarachnoid haemorrhage (naSAH) is an unusual finding that could be burdened by significant mortality and morbidity rates. Rare pathologies and delayed diagnosis could be advocated as responsible of unfavourable outcomes. Herein, we describe an exceedingly rare giant lumbar spinal hemangioblastoma (80 × 23 mm) presenting as an intracranial naSAH. Based on our radiological and clinical findings a pathophysiological hypothesis linking intracranial naSAH to venous hypertension was discussed for the first time even among lumbar spinal tumors. Although rare, unusual causes should be investigated in presence of radiological atypical finding as a prompt evaluation and treatment could be needed.

Effect of extracranial-intracranial bypass revascularization procedure in acute stroke after endovascular failure: the EIRASP study protocol.

BACKGROUND: Intravenous thrombolysis and endovascular reperfusion represent nowadays the standard treatment for acute ischemic stroke. However, ineffective reperfusion may occur, representing a major negative prognostic factor on clinical outcome. Extracranial-intracranial (EC-IC) bypass revascularization procedure in an acute setting appears as a promising tool to increase reperfusion rates and improve clinical outcome in a highly selected population refractory or ineligible for standard reperfusion therapies. METHODS: The Extracranial-Intracranial Revascularization for Acute Stroke - Parma (EIRASP) study is an observational, prospective, single-center, study (protocol 203/2020/OSS/AOUPR). Patients admitted for an acute ischemic anterior circulation stroke due to large vessels occlusion and refractory or ineligible for standard reperfusion therapies will be submitted to an extracranial-intracranial bypass revascularization procedure when fulfilling all clinical and radiological inclusion criteria. The primary outcome will be the functional outcome (modified Rankin Scale and NIHSS score) at 3 months after the surgical procedure. Secondary outcome will include the evaluation of clinical and surgical complications rates, quantitative monitoring of perfusion parameters, and further functional and survival rates. RESULTS: Despite promising data regarding the feasibility and the favorable outcome of urgent EC-IC bypass revascularization procedure in selected patients suffering an acute ischemic stroke are emerging in literature, no studies to date have prospectively explored the real potential of this technique. CONCLUSIONS: The EIRASP study aims to provide further and stronger methodological evidence of the benefit of urgent EC-IC bypass revascularization procedure in acute ischemic stroke.

A minimally invasive approach for giant middle cerebral artery thrombosed aneurysms treatment.

BACKGROUND: Management of complex thrombosed aneurysms of the middle cerebral artery (MCA) is challenging. Lesions not amenable to endovascular techniques or direct clipping might require a bypass procedure with subsequent aneurysm occlusion. Various bypass techniques followed by surgical or endovascular closure of the aneurysm are available, but an unpredictable extension of the thrombus to the parent vessel and/or to perforator vessels can occur. We presented a multidisciplinary technique with the aim to reduce invasiveness and complications. METHODS: We present two patients, harboring a thrombosed giant MCA bifurcation aneurysm, who were treated with a minimally invasive three-steps multimodality procedure. In both cases, through a limited exposure of the sylvian fissure, a side-to-side anastomosis between the two M2 branches was performed, followed in the immediate postop by an endovascular occlusion of the frontal M2 branch, with the aim of transforming a bifurcation aneurysm in a sidewall aneurysm, that was then treated a few days later by flow diverter deployment. RESULTS: Both patients had excellent outcomes and were discharged after 7 days without neurological deficits. CONCLUSIONS: Treatment of complex thrombosed MCA aneurysms is challenging. Side-to-side M2 anastomosis with the aim of transforming a bifurcation aneurysm in a sidewall aneurysm, suitable to be treated few days later by flow diverter deployment, offers a minimally invasive multimodal approach with the possibility of reducing serious complications.

Subtemporal-Transtentorial Approach for Microsurgical Resection of Hemorrhagic Ambient Cistern Arteriovenous Malformation.

Arteriovenous malformations (AVMs) of the ambient cistern are an extremely rare and complex subgroup of vascular malformation, representing a clinical challenge due to the deep-seated, highly eloquent anatomic location and the debilitating, life-threatening consequences related to hemorrhagic presentation and surgical morbidity. Ultimately, a tailored treatment, based on the presenting symptoms, AVM angioarchitecture, and annual risk of hemorrhage should be discussed among a multidisciplinary team to find the best individualized strategy balancing between the pros and cons of each approach. In Video 1, we present the case of a 60-year-old man with a hemorrhaged AVM of the right ambient cistern, present the pros and cons of each possible treatment strategy, and illustrate the successful resection of this lesion through a subtemporal-transtentorial microsurgical approach.

Using a Smartphone as an Exoscope Where an Operating Microscope is not Available.

OBJECTIVE: Neurosurgical operating rooms are equipped with microscopes in order to provide a good standard of care. Nevertheless, in developing countries, microscopes are not always available. During a short period in a western Africa hospital, we adapted our smartphones as a valid alternative to the microscope. METHODS: Using a shaped tin can, a smartphone cover, and a rod fixed to the bed, we could make a support for a smartphone creating a simple "homemade" exoscope, which allowed us to have magnification and light in the surgical field. RESULTS: Among others, we performed 5 surgical interventions of both spinal and brain surgery using our smartphone as a magnifier. This allowed us to overcome the absence of a better magnification system. CONCLUSIONS: This simple "smartphone-based exoscope" allows surgeons to get an adequate magnification during surgery when microscopes or magnification goggles are not available. It can be a useful solution in developing countries where often nothing better is available.

Contemporary tools in arteriovenous malformations surgery.

Arteriovenous malformations (AVMs) are rare entities and therefore considered the main challenge for a neurosurgeon. Since the publication of the ARUBA study, one of the most popular debate regards the actual surgical indication for unruptured AVMs. Our group recently published a multicenter review of more than 500 cases underlying the important role of surgery. Over the last few decades, the expanding technologies used in the treatment of AVMs have shown an ongoing improvement overcoming some of the existing difficulties and shortcomings. In this paper, we reviewed the present literature to illustrate the main contemporary tools that, in our opinion, are crucial to obtain the best surgical and clinical outcome. Indocyanin green is nowadays considered a gold standard to identify arterial feeders, draining veins, and to detect any eventual residual. The use of non-stick, bipolar, 2-mm blade microclips, and thulium laser allows to obtain a better bleeding control and nidus removal. The development of the intraoperative ultrasound with neuronavigation, angiosonography, and color-Doppler improves the accuracy of AVM resection. Moreover, improvements have been developed with the use of intraoperative micro-Dopplers combined with flow measurements, which consent to verify the gradual reduction of flow through draining veins. The possibility to perform functional preoperative studies and intraoperative monitoring can be considered as an essential point in the decision making in eloquent or near-eloquent AVMs. Furthermore, the hybrid operating room represents the best expression of an excellent neurovascular team where the use of the intraoperative angiography allows neurosurgeons and neurointerventional radiologists to work at the same time in a combined approach to achieve the best surgical removal.

Unruptured Versus Ruptured AVMs: Outcome Analysis from a Multicentric Consecutive Series of 545 Surgically Treated Cases.

BACKGROUND: Recent literature strongly challenged indications to perform preventive surgery in unruptured arteriovenous malformation (AVM) claiming that invasive AVM treatment is associated with a significant risk of complications and thus conservative management may be a preferable alternative in many patients. On the other hand, the recent improvement of surgical instrumentation and treatment strategies (both surgical and interventional) yielded better outcomes than those achieved only a decade ago. Therefore, even among specialists, a wide variety of opinions, concerning the treatment of unruptured AVM, can be found. METHODS: This multicenter retrospective study analyzes a consecutive series of 545 surgically treated AVMs in 10 different hospitals in Italy. RESULTS: Patients with AVMs treated after hemorrhage had an unfavorable (modified Rankin Scale score >1) outcome in more than one third (37.69%) of the cases. Conversely, with proper indications, unruptured AVMs treated preventively have a good outcome in 93.8% of cases, increasing to 95.7%, with no death, if only Spetzler-Martin grades 1-3 are considered (P < 0.05). Outcomes on discharge significantly (P < 0.05) improve at 6 months with the disappearance of many of the initial neurologic deficits that turn out to be transient. CONCLUSIONS: In unruptured low-risk AVMs (Spetzler-Martin grades 1-3), over time, the risk of surgery-associated neurologic deficits becomes lower than that linked to spontaneous hemorrhage, with a crossover point at 6.5 years. Because the average bleeding age is less than 45 years, preventive surgery can be advocated to safeguard the patient and overcome the risks associated with the natural history of AVMs.

Post-neurosurgical meningitis: Management of cerebrospinal fluid drainage catheters influences the evolution of infection.

BACKGROUND: In order to better define the pathogenic role of cerebrospinal fluid (CSF) drainage catheters in postoperative patients, we comparatively analyze the clinical course of device and non-device-related meningitis. METHODS: This is an observational, partially prospective, study on consecutive adult patients who developed meningitis after undergoing neurosurgical procedures at the Neurosurgery and Neurointensive care Departments, Spedali Civili, Brescia, Italy, between January 1999 and August 2007. RESULTS: All 77 consecutive post-neurosurgical meningitis events in 65 patients were included in the analysis. Most were classified as external ventricular drainage (EVD)-related meningitis (23 cases, group A), external spinal drainage (ESD)-related meningitis (12 cases, group B), and non-device-related post-neurosurgical meningitis (30 cases, group C). Proven meningitis was identified in 78.3%, 91.7% and 56.7% of the events, respectively. ESD-related meningitis had a shorter onset time vs EVD and non-device-associated meningitis (3 days versus 6 and 7 days, respectively). Median antibiotic treatment duration was 20, 17, and 22.5 days in groups A, B, and C, respectively. Overall, 8 patients (34.8%) in group A, 3 (25.0%) in group B, and 3 (10.0%) in group C died. Median time to become afebrile was shorter in group C than in group A (10 days versus 12 days, P = 0.04). Removal of the device later than 48 hours after meningitis onset, as well as implantation of a second device were associated with a slower time of meningitis resolution. CONCLUSIONS: Early device removal and avoiding implantation of a second device were associated with short illness duration. Larger studies are warranted to confirm the conclusions of this study.

Surgical Treatment of Inadvertent Internal Carotid Artery Lesion by Extraintracranial High-flow Bypass. A Case Report and Review of the Literature.

Internal carotid artery (ICA) injury following transsphenoidal surgery is a rare but potentially fatal complication. Usually, endovascular occlusion of the ICA or stent graft placement is the treatment of these vascular complications described in literature. We present a case of ICA perforation during transsphenoidal surgery in a patient with limited collateral cerebral blood flow and with ectasia of the ICA that rule out an endovascular treatment. We report the surgical revascularization via high-flow extra-intracranial radial artery bypass and consicutive artery ligation.