Microsurgical Clipping of Unruptured Anterior Circulation Aneurysms-A Global Multicenter Investigation of Perioperative Outcomes.

BACKGROUND AND OBJECTIVES: Microsurgical aneurysm repair by clipping continues to be highly important despite increasing endovascular treatment options, especially because of inferior occlusion rates. This study aimed to present current global microsurgical treatment practices and to identify risk factors for complications and neurological deterioration after clipping of unruptured anterior circulation aneurysms. METHODS: Fifteen centers from 4 continents participated in this retrospective cohort study. Consecutive patients who underwent elective microsurgical clipping of untreated unruptured intracranial aneurysm between January 2016 and December 2020 were included. Posterior circulation aneurysms were excluded. Outcome parameters were postsurgical complications and neurological deterioration (defined as decline on the modified Rankin Scale) at discharge and during follow-up. Multivariate regression analyses were performed adjusting for all described patient characteristics. RESULTS: Among a total of 2192 patients with anterior circulation aneurysm, complete occlusion of the treated aneurysm was achieved in 2089 (95.3%) patients at discharge. The occlusion rate remained stable (94.7%) during follow-up. Regression analysis identified hypertension (P < .02), aneurysm diameter (P < .001), neck diameter (P < .05), calcification (P < .01), and morphology (P = .002) as preexisting risk factors for postsurgical complications and neurological deterioration at discharge. Furthermore, intraoperative aneurysm rupture (odds ratio 2.863 [CI 1.606-5.104]; P < .01) and simultaneous clipping of more than 1 aneurysm (odds ratio 1.738 [CI 1.186-2.545]; P < .01) were shown to be associated with an increased risk of postsurgical complications. Yet, none of the surgical-related parameters had an impact on neurological deterioration. Analyzing volume-outcome relationship revealed comparable complication rates (P = .61) among all 15 participating centers. CONCLUSION: Our international, multicenter analysis presents current microsurgical treatment practices in patients with anterior circulation aneurysms and identifies preexisting and surgery-related risk factors for postoperative complications and neurological deterioration. These findings may assist in decision-making for the optimal therapeutic regimen of unruptured anterior circulation aneurysms.

Global Outcomes for Microsurgical Clipping of Unruptured Intracranial Aneurysms: A Benchmark Analysis of 2245 Cases.

BACKGROUND AND OBJECTIVES: Benchmarks represent the best possible outcome and help to improve outcomes for surgical procedures. However, global thresholds mirroring an optimal and reachable outcome for microsurgical clipping of unruptured intracranial aneurysms (UIA) are not available. This study aimed to define standardized outcome benchmarks in patients who underwent clipping of UIA. METHODS: A total of 2245 microsurgically treated UIA from 15 centers were analyzed. Patients were categorized into low- ("benchmark") and high-risk ("nonbenchmark") patients based on known factors affecting outcome. The benchmark was defined as the 75th percentile of all centers' median scores for a given outcome. Benchmark outcomes included intraoperative (eg, duration of surgery, blood transfusion), postoperative (eg, reoperation, neurological status), and aneurysm-related factors (eg, aneurysm occlusion). Benchmark cutoffs for aneurysms of the anterior communicating/anterior cerebral artery, middle cerebral artery, and posterior communicating artery were determined separately. RESULTS: Of the 2245 cases, 852 (37.9%) patients formed the benchmark cohort. Most operations were performed for middle cerebral artery aneurysms (53.6%), followed by anterior communicating and anterior cerebral artery aneurysms (25.2%). Based on the results of the benchmark cohort, the following benchmark cutoffs were established: favorable neurological outcome (modified Rankin scale ≤2) ≥95.9%, postoperative complication rate ≤20.7%, length of postoperative stay ≤7.7 days, asymptomatic stroke ≤3.6%, surgical site infection ≤2.7%, cerebral vasospasm ≤2.5%, new motor deficit ≤5.9%, aneurysm closure rate ≥97.1%, and at 1-year follow-up: aneurysm closure rate ≥98.0%. At 24 months, benchmark patients had a better score on the modified Rankin scale than nonbenchmark patients. CONCLUSION: This study presents internationally applicable benchmarks for clinically relevant outcomes after microsurgical clipping of UIA. These benchmark cutoffs can serve as reference values for other centers, patient registries, and for comparing the benefit of other interventions or novel surgical techniques.

Reoperation in Chiari-1 Malformations.

(1) Background: The issue of unsuccessful surgery for Chiari-1 malformation (CM-1), as well as its potential causes and possible solutions, remains poorly documented and studied. (2) Methods: From a retrospective review of a personal series of 98 patients undergoing treatment for CM-1 during the past 10 years, we created two study groups. Group 1: 8 patients (8.1%) requiring additional surgeries owing to postoperative complications (7 cerebrospinal fluid leakage, 1 extradural hematoma); 7 patients (7.1%) undergoing reoperations for failed decompression during the follow-up. Group 2: During the same period, we also managed 19 patients who had previously been operated on elsewhere: 8 patients who required adequate CM-1 treatment following extradural section of the filum terminale; 11 patients requiring reoperations for failed decompression. Failed decompression was managed by adequate osteodural decompression, which was associated with tonsillectomy (6 cases), subarachnoid exploration (8 cases), graft substitution (6 cases), and occipito-cervical fixation/revision (1 case). (3) Results: There was no mortality or surgical morbidity in Group 1. However, one patient's condition worsened due to untreatable syrinx. In Group 2, there were two cases of mortality, and surgical morbidity was represented by functional limitation and pain in the patient who needed revision of the occipitocervical fixation. Twenty patients improved (58.8%), 6 remained unchanged (32.3%), 1 worsened (2.9%) and 2 died (5.9%). (4) Conclusions: The rate of complications remains high in CM-1 treatment. Unfortunately, a certain rate of treatment failure is unavoidable, but it appears that a significant number of re-operations could have been avoided using proper indications and careful technique.

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.

Clinical considerations on a right operculo-insular cavernous angioma: an illustrative case.

The insular cortex is considered one of the most complex regions of the brain, defined as the "hub" of somatosensory areas. Here, we examine the case of a surgically treated haemorrhagic cavernoma involving the middle and posterior insular cortex, presenting both sensory, gustative and speech symptoms. By reviewing the recent findings in humans' and primates' basic research, we illustrated clinical and radiological correlations of the reported case, confirming insular role in sensitive and gustatory functions.

Surgical management of Chiari malformation type II.

BACKGROUND: Chiari malformation type II is present in almost all patients with myelomeningocele but usually remains asymptomatic. Symptoms are generally more severe in neonates, who have the worst prognosis. The association symptoms/hydrocephalus is well known, and first treatment usually consists of ensuring adequate ventricular drainage. Craniovertebral decompression may be required in patients who do not improve after drainage. However, mechanisms of symptom development are not yet completely understood, timing and techniques of surgery are not codified, long-term evolution is poorly reported, and there are few paper reporting clinical onset and treatment in older patients. METHODS: We reviewed our personal series of 42 consecutive symptomatic patients that required surgical treatment. Age at surgery ranged from 1 week to 44 years (mean 6.6 years). Surgical timing strictly depended on clinical conditions: urgent management in the more compromised patients (usually infants) and elective treatment before severe deterioration in patients with less severe conditions. All patients first underwent external ventricular drainage, which resolved the symptomatology in 17 cases (40%). Craniocervical decompression was required by 25 patients (60%) who received no benefit from the ventricular drainage. RESULTS: Early mortality (2 cases = 4.7%) occurred only in neonates. Clinical improvement was achieved in 37 of 40 survivors (92%). During a follow-up ranging from 2 to 20 years (mean 10.3 years), late mortality consisted of 4 cases (10%), mainly due to cardio-respiratory arrest. Twenty-two patients (55%) required surgery for shunt malfunction and 4 for cord detethering. Six patients (15%) required reoperation owing to symptom recurrence. CONCLUSION: Early treatment of symptomatic Chiari II malformations may warrant satisfactory results in a significant number of patients, even in neonates. Nevertheless, overall mortality remains relatively high, throughout the patient life. Formal transition programs and adult spina bifida care processes have become crucial.

Acute presentation of Chiari 1 malformation in children.

PURPOSE: To review the literature about the acute presentation of Chiari 1 malformation in children, with a focus on acute cervical cord syndromes with impairment of the cortico-spinal tract. To analyze the possible precipitating factors and the pathophysiology of the acute onset. METHOD: Illustrative case presentation with literature review. RESULTS: The literature includes just a few dozens of children with acute presentation of Chiari 1 malformation. The more frequent presentations consist of oropharyngeal dysfunction, cranial nerve impairment, high intracranial pressure, peripheral motor deficit. Acute impairment of cervical long tracts is very rare and we could find only 16 previously reported cases of cervical cord impairment with quadriparesis or hemiparesis. CONCLUSIONS: Nowadays, a lot of asymptomatic Chiari 1 malformations are frequently observed owing to the wide diffusion of magnetic resonance imaging. This raised the question about the management of these patients. Despite severe and even lethal manifestations being reported in previously asymptomatic patients, the absolute rarity of acute deterioration does not justify prophylactic surgery. The diagnosis of Chiari malformation may be initially difficult in patients with isolated, acute, and unusual presentations but physicians should bear in mind its possibility, because prompt cranio-cervical decompression may be decisive.

Endoscopic Third Ventriculostomy in Cases of Ventriculoperitoneal Shunt Malfunction: Does Shunt Duration Play a Role?

BACKGROUND: Endoscopic third ventriculostomy (ETV) is now widely used to manage ventriculoperitoneal shunt (VPS) malfunctions, but outcome predictors are still debated. Different opinions exist about the prognostic factors, but shunt duration is generally considered unimportant although its influence remains poorly investigated. METHODS: A total of 139 patients undergoing ETV for VPS malfunction were reviewed. Successful ETV was defined as shunt independence. There were 56 children and 83 adults; hydrocephalus had different causes. The mean VPS-ETV interval was 8.1 years. RESULTS: Ninety patients (64.7%) became shunt free. Children and adults achieved comparable success rates (64.3% and 65.1%, respectively). Age, gender, and cause of shunt malfunction were scarcely significant. The success rates were 86.8% (33/38 patients) in obstructive hydrocephalus (OH), 55.2% (36/67) in communicating hydrocephalus, and 58.8% (21/34) in myelomeningocele-related hydrocephalus, which was significant (P = 0.02). History of multiple revisions was a negative predictor (P < 0.001): success rate, 39% (16/48) versus 81.3% (74/91). Any individual time step increase reduced the odds of ETV success by 34% (P = 0.014). In OH, the results were good regardless of any other factor, including shunt duration. In communicating hydrocephalus, short VPS-ETV intervals correlated with better outcome (P = 0.021), although they were irrelevant in perinatal posthemorrhagic hydrocephalus. In myelomeningocele-related hydrocephalus, shunt duration had intermediate effects. CONCLUSIONS: ETV is the first option for shunt malfunctions in OH and perinatal posthemorrhagic hydrocephalus, regardless of other factors. Conversely, in other types of hydrocephalus, the chances of shunt independence are lower and shunt duration and history of multiple shunt revisions are significant.

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.

Paratrigeminal, Paraclival, Precavernous, or All of the Above? A Circumferential Anatomical Study of the C3-C4 Transitional Segment of the Internal Carotid Artery.

BACKGROUND: Although the term paraclival carotid pervades recent skull base literature, no clear consensus exists regarding boundaries or anatomical segments. OBJECTIVE: To reconcile various internal carotid artery (ICA) nomenclatures for transcranial and endoscopic-endonasal perspectives, we reexamined the transition between lacerum (C3) and cavernous (C4) segments using a C1-C7 segments schema. In this cadaveric study, we obtained a 360°-circumferential view integrating histological, microsurgical, endoscopic, and neuroradiological analyses of this C3-C4 region and identified a distinct transitional segment. METHODS: In 13 adult, silicone-injected, formalin-fixed cadaveric heads (26 sides), transcranial-extradural-subtemporal and endoscopic-endonasal CT-guided dissections were performed. A quadrilateral area was noted medial to Meckel's cave between cranial nerve VI, anterolateral and posterolateral borders of the lateral-paratrigeminal aspect of the precavernous ICA, and posterior longitudinal ligament. Endoscopically, a medial-paraclival aspect was defined. Anatomical correlations were made with histological and neuroradiological slides. RESULTS: We identified a distinct precavernous C3-C4 transitional segment. In 18 (69%) specimens, venous channels were absent at the quadrilateral area, on the paratrigeminal border of the precavernous ICA. A trigeminal membrane, seen consistently on the superior border of V2, defined the lateral aspect of the cavernous sinus floor. The medial aspect of the precavernous ICA corresponded with the paraclival ICA. CONCLUSION: Our study revealing the juncture of 2 complementary borders of the ICA, endoscopic endonasal (paraclival) and transcranial (paratrigeminal), reconciles various nomenclature. A precavernous segment may clarify controversies about the paraclival ICA and support the concept of a "safe door" for lesions involving Meckel's cave, cavernous sinus, and petrous apex.

Use of Laser in Arteriovenous Malformation Surgery.

BACKGROUND: Arteriovenous malformation surgery is particularly demanding owing to the need to control bleeding of small, deep white matter vessels during and after removal of the nidus; this is probably one of the most critical moments of arteriovenous malformation surgery. The aim of this article is to describe a useful technique based on the use of tweezers to temporarily stop the blood flow followed by coagulation with the thulium laser. METHODS: Surgery was performed in 20 patients with unruptured cerebral arteriovenous malformations. In each case, the superficial feeder vessels were easily coagulated with nonstick bipolar tips. The finer and deeper feeder vessels were coagulated with use of tweezers and thulium laser. RESULTS: All patients were treated successfully. Optimal intraoperative hemostasis was achieved. CONCLUSIONS: Results were good with no postoperative complications. Our results could encourage a more standardized use of the described technique.

Posttraumatic atlantoaxial rotatory dislocation in a healthy adult patient: a case report and review of the literature.

Atlantoaxial rotatory dislocation (AARD) is a rare complication in adults usually leading to pain, spinal cord injury, or death. Clinical and radiological diagnosis is difficult and often delayed. We report a rare case of posttraumatic AARD in a neurological intact 27-year-old male in which initial radiographic evaluation was negative. A computed tomography (CT) scan was promptly done because the patient showed a severe torticollis. Therefore, early diagnosis, immobilisation, and surgical fusion and arthrodesis were performed. After surgery, cervical pain and torticollis were resolved and the patient remained neurologically intact with a CT scan documentation of fusion at the 3-year followup.

Heterotopic ossification in vertebral interlaminar/interspinous instrumentation: report of a case.

We present here a rare case of heterotopic ossification in interspinous/interlaminar Coflex device. The classical surgical indications for these implants are degenerative canal stenosis, discogenic low back pain, disk herniations, facet syndrome, and instability. However, fractures of spinous processes are a potential risk after interspinous/interlaminar devices' implantation. Recently, heterotopic ossification, a well-known complication of hip and knee arthroplasty, has been reported after cervical and lumbar prosthesis. We performed undercutting and implantation of the dynamic interspinous/interlaminar device to treat an adult male patient with L4-L5 stenosis. The patient underwent 45-day imaging and clinical followup, and we observed both a neurological and imaging improvement. A CT bone scan, performed 3 years after surgery for recurrence of neurogenic claudication, showed a new stenosis due to an abnormal ossification all over the device. To our knowledge, this is the first reported case of heterotopic ossification in an interspinous/interlaminar dynamic device. Accordingly, we aim to suggest it as a new complication of interspinous/interlaminar devices.

Validation of the Italian version of a new coma scale: the FOUR score.

The Glasgow Coma Scale (GCS) is the most widely accepted tool for the evaluation of consciousness, despite several reported shortcomings. A new coma scale, named Full Outline of UnResponsiveness (FOUR) score, is now available. The aim of the present study is to provide and validate the Italian version of the FOUR score. The Italian version of the FOUR score was developed according to a standardized protocol, and thereafter validated in a series of patients with acute neurological illness. For each patient, the FOUR and the GCS scores were recorded by two physicians randomly selected. The inter-rater agreement for the FOUR and the GCS scores was evaluated using the weighted kappa (κ(w)). The receiving operating characteristic curve was also calculated to determine the ability of the scales to predict outcome. Eighty-seven consecutive patients with an acute brain injury were enrolled. The inter-rater agreement was excellent both for the FOUR (κ(w) = 0.953; P < 0.0001) and the GCS (κ(w) = 0.943; P < 0.01). The area under the curve for mortality was 0.935 for the FOUR and 0.953 for the GCS. The FOUR score provides greater neurological details than the GCS. Our data indicate that the Italian version of the FOUR score is a valid predictor of outcome, yielding reproducible findings across raters independent of their expertise.