Comparison of intraoperative sodium fluorescein and indocyanine green videoangiography during intracranial aneurysm and arteriovenous malformation surgery.

OBJECTIVE: Indocyanine green (ICG) and sodium fluorescein (Na-Fl) are two fluorophores, which are used for videoangiography purposes. This prospective study reports our experience by using surgical microscopes equipped with two special filters. We compared the imaging efficacy of Na-FL and ICG videoangiography techniques during aneurysm and arteriovenous malformations (AVM) surgeries. PATIENT AND METHODS: Fourtynine consecutive patients were operated between September 2015 and December 2022. Patients with ruptured/unruptured aneurysms or with AVMs presented with/without hemorrhage were included to the current study. RESULTS: There were a total of 48 aneurysms and 11 AVMs in 49 patients in the current study. Na-Fl enables the surgeon to manipulate vessels and aneurysms real-time. ICG provides the ability to watch the videoangiography repeatedly and understand the angioarchitecture. The use of FLOW-800 module allows the surgeon to make concrete judgements about the flow dynamics of AVMs and therefore ICG videoangiography found useful in AVM surgery. Na-Fl has been found more useful for the evalution of the low caliber perforating arteries and anatomical features of the aneursym dome in aneurysm surgery. CONCLUSION: The results of our series demonstrated the safety and efficacy of Na-Fl use in the surgery of aneurysms and AVMs. Both the ICG and Na-Fl videoangiographies are easy to perform and complimentary to each other. Combined use of these two mediums may provide better surgical results, considering the separate advantages and disadvantages of these both techniques.

Intraventricular Shunt Catheter Placement of Adult Normal Pressure Hydrocephalus Using an AxiEMTM Electromagnetic Neuronavigation System: A Single-Center Experience.

AIM: To prove the superiority of the electromagnetic (EM) neuronavigation technique to increase the accuracy of intraventicular shunt catheter placement, and to reduce accompanying complications. MATERIAL AND METHODS: A total of 21 patients with hydrocephalus [age range (years): 53-84] were studied. All of them had undergone thin-slice, navigation-compatible, computed tomography (CT) preoperatively. Shunt surgery was performed under the guidance of EM neuronavigation technology. All patients underwent follow-up CT the next day to evaluate catheter tip placement and were followed up at 1, 3, 6, and 12 months. RESULTS: All catheter tips were placed properly in front of the foramen of Monro in the desired position, except in one case in which the tip migrated to the perimesencephalic cistern and underwent reoperation in the early postoperative period. No complications due to infection and obstruction were observed in the medium- and long-term follow-ups. The complication rate due to the incorrect catheter positioning was 4.76% of the total cases. CONCLUSION: The placement of the ventricular catheter under EM-guided navigation technology reduces the proximal-end failure caused by malpositioning, obstruction, and infection.

Contralateral vs. Ipsilateral Approach to Superior Hypophyseal Artery Aneurysms: An Anatomical Study and Morphometric Analysis.

Introduction: Surgical clipping of superior hypophyseal artery (SHA) aneurysms is a challenging task for neurosurgeons due to their close anatomical relationships. The development of endovascular techniques and the difficulty in surgery have led to a decrease in the number of surgical procedures and thus the experience of neurosurgeons in this region. In this study, we aimed to reveal the microsurgical anatomy of the ipsilateral and contralateral approaches to SHA aneurysms and define their limitations via morphometric analyses of radiological anatomy, three-dimensional (3D) modeling, and surgical illustrations. Method: Five fixed and injected cadaver heads underwent dissections. In order to make morphometric measurements, 75 cranial MRI scans were reviewed. Cranial scans were rendered with a module and used to produce 3D models of different anatomical structures. In addition, a medical illustration was drawn that shows different sizes of aneurysms and surgical clipping approaches. Results: For the contralateral approach, pterional craniotomy and sylvian dissection were performed. The contralateral SHA was reached from the prechiasmatic area. The dissected SHA was approached with an aneurysm clip, and maneuverability was evaluated. For the ipsilateral approach, pterional craniotomy and sylvian dissection were performed. The ipsilateral SHA was reached by mobilizing the left optic nerve with left optic nerve unroofing and left anterior clinoidectomy. MRI measurements showed that the area of the prechiasm was 90.4 ± 36.6 mm2 (prefixed: 46.9 ± 10.4 mm2, normofixed: 84.8 ± 15.7 mm2, postfixed: 137.2 ± 19.5 mm2, p < 0.001), the distance between the anterior aspect of the optic chiasm and the limbus sphenoidale was 10.0 ± 3.5 mm (prefixed: 5.7 ± 0.8 mm, normofixed: 9.6 ± 1.6 mm, postfixed:14.4 ± 1.6 mm, p < 0.001), and optic nerves' interneural angle was 65.2° ± 10.0° (prefixed: 77.1° ± 7.3, normofixed: 63.6° ± 7.7°, postfixed: 57.7° ± 5.7°, p: 0.010). Conclusion: Anatomic dissections along with 3D virtual model simulations and illustrations demonstrated that the contralateral approach would potentially allow for proximal control and neck control/clipping in smaller SHA aneurysm with relatively minimal retraction of the contralateral optic nerve in the setting of pre- or normofixed chiasm, and ipsilateral approach requires anterior clinodectomy and optic unroofing with considerable optic nerve mobilization to control proximal ICA and clip the aneurysm neck effectively.

Is elective cancer surgery feasible during the lock-down period of the COVID-19 pandemic? Analysis of a single institutional experience of 404 consecutive patients.

BACKGROUND: We aimed to assess the feasibility and short-term clinical outcomes of surgical procedures for cancer at an institution using a coronavirus disease 2019 (COVID-19)-free surgical pathway during the peak phase of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pandemic. MATERIALS AND METHODS: This was a single-center study, including cancer patients from all surgical departments, who underwent elective surgical procedures during the first peak phase between March 10 and June 30, 2020. The primary outcomes were the rate of postoperative SARS-CoV-2 infection and 30-day pulmonary or non-pulmonary related morbidity and mortality associated with SARS-CoV-2 disease. RESULTS: Four hundred and four cancer patients fulfilling inclusion criteria were analyzed. The rate of patients who underwent open and minimally invasive procedures was 61.9% and 38.1%, respectively. Only one (0.2%) patient died during the study period due to postoperative SARS-CoV2 infection because of acute respiratory distress syndrome. The overall non-SARS-CoV2 related 30-day morbidity and mortality rates were 19.3% and 1.7%, respectively; whereas the overall SARS-CoV2 related 30-day morbidity and mortality rates were 0.2% and 0.2%, respectively. CONCLUSIONS: Under strict institutional policies and measures to establish a COVID-19-free surgical pathway, elective and emergency cancer operations can be performed with acceptable perioperative and postoperative morbidity and mortality.

Lighting Up the Tumor-Fluorescein-Guided Resection of Gangliogliomas.

(1) Background: Gangliogliomas comprise a small number of brain tumors. They usually present as World Health Organization (WHO) grade I, and they delineate on gadolinium-enhanced MRI; the surgical goal is wide radical resection, and the course thereafter is usually benign. Fluorescein sodium (FL) tends to accumulate in areas with altered blood-brain barrier (BBB). Thus far, the results provided by prospective and retrospective studies show that the utilization of this fluorophore may be associated with better visualization and improvement of resection for several tumors of the central nervous system. In this study, we retrospectively studied the effect of fluorescein sodium on visualization and resection of gangliogliomas. (2) Methods: Surgical databases in three neurosurgical departments (Regensburg University Hospital; Besta Institute, Milano, Italy; and Liv Hospital, Istanbul, Turkey), with approval by the local ethics committee, were retrospectively reviewed to find gangliogliomas surgically removed by a fluorescein-guided technique by the aid of a dedicated filter on the surgical microscope from April 2014 to February 2020. Eighteen patients (13 women, 5 men; mean age 22.9 years, range 3 to 78 years) underwent surgical treatment for gangliogliomas during 19 operations. Fluorescein was intravenously injected (5 mg/kg) after general anesthesia induction. Tumors were removed using a microsurgical technique with the YELLOW 560 Filter (YE560) (KINEVO/PENTERO 900, Carl Zeiss Meditec, Oberkochen, Germany). (3) Results: No side effects related to fluorescein occurred. In all tumors, contrast enhancement on preoperative MRI correlated with bright yellow fluorescence during the surgical procedure (17 gangliogliomas WHO grade I, 1 ganglioglioma WHO grade II). Fluorescein was considered helpful by the operating surgeon in distinguishing tumors from viable tissue in all cases (100%). Biopsy was intended in two operations, and subtotal resection was intended in one operation. In all other operations considered preoperatively eligible, gross total resection (GTR) was achieved in 12 out of 16 (75%) instances. (4) Conclusions: The use of FL and YE560 is a readily available method for safe fluorescence-guided tumor resection, possibly visualizing tumor margins intraoperatively similar to contrast enhancement in T1-weighted MRI. Our data suggested a positive effect of fluorescein-guided surgery on intraoperative visualization and extent of resection during resection of gangliogliomas.

Intracranial cystic meningiomas: A series of six patients.

OBJECTIVE: Although meningiomas are the most common primary non-glial intracranial tumors, cystic meningiomas are quite rare. This study presents six cases in order to discuss the radiological and pathological features of cystic meningiomas. PATIENTS AND METHODS: Six patients with cystic meningiomas were included in the study. All patients underwent a cranial computed tomography scan and magnetic resonance imaging (MRI) evaluation, pre- and postoperatively. RESULTS: All patients presented with long standing headache dating back at least two years. There was no gender predominance in our series. Radiological evaluation revealed two parasagittal and two convexity meningiomas located at the frontal region. Two lesions were located at the tuberculum sellae and the foramen magnum. All of the tumors were totally excised (Simpson Grade I or II). Pathology results included meningothelial meningioma in three patients, angiomatous meningioma in two patients, and metaplastic meningioma in one patient. In two patients, the cystic meningiomas were resected with the use of sodium fluorescein (Na-Fl) under a YELLOW 560nm microscope filter. Na-Fl was found to be very useful in demonstrating the brain-tumor interface, and it was especially effective in resecting the cyst wall of the peritumoural cystic meningiomas. None of the patients had any complications, and no recurrences were noted in any of the patients within the mean follow-up period of 51 months (range: 16-102 months). CONCLUSION: It is important to note MRI changes specific to cystic meningioma and include meningiomas in the differential diagnosis of intracranial cystic lesions. The use of sodium fluorescein (Na-Fl) under a YELLOW 560nm microscope filter is a useful tool to differentiate the brain-tumor interface, as well as to identify the cyst wall in order to fully resect the tumor with the cystic component to avoid recurrence and achieve better clinical results.

Fluorescein Sodium in the Surgical Treatment of Recurrent Glioblastoma Multiforme.

BACKGROUND: Glioblastoma multiforme (GBM) is the most common primary brain tumor and has a high recurrence rate. Maximizing the extent of resection (EOR) in recurrent GBM has proved to be the cornerstone of neurosurgical retreatment. The development of surgical microscopes fitted with fluorescein-specific filters has facilitated fluorescein-guided microsurgery and the identification of tumor tissue. Use of fluorescein sodium (FL) in primary high-grade glioma resection has shown promising results. Here, we present our experience with FL and the dedicated surgical microscope filter YELLOW 560 nm in 106 patients with recurrent GBM. METHODS: A total of 106 patients with recurrent GBM were included (53 women, 53 men; mean age, 53 years). A total of 5 mg/kg bodyweight of FL was intravenously injected approximately 45 minutes before craniotomy. A YELLOW 560 nm filter (PENTERO 900 [Carl Zeiss Meditec, Oberkochen Germany]) was used for microsurgical tumor resection and resection control. Surgical reports were reviewed regarding the degree of fluorescent staining. Postoperative magnetic resonance images were examined within 48 hours after surgery regarding the EOR and postoperative course regarding neurologic outcome, complications, and any adverse events. RESULTS: Bright fluorescent staining was present in all patients, which markedly enhanced tumor visibility and was deemed helpful for tumor resection. Seventeen patients (16%) showed residual tumor tissue on postoperative magnetic resonance imaging (MRI). Therefore, gross total resection was achieved in 89 patients (84%). No adverse events were registered postoperatively. CONCLUSIONS: FL and YELLOW 560 nm are readily available methods for fluorescence-guided tumor resection, similar to contrast enhancement in T1-weighted MRI. FL may improve resection in recurrent GBM with minimal risk, and tumor margins are clearly visualized. FL and the YELLOW 560 nm filter are safe and feasible tools for safe maximal resection of recurrent glioblastoma.

Sodium fluorescein-guided brain tumor surgery under the YELLOW-560-nm surgical microscope filter in pediatric age group: feasibility and preliminary results.

OBJECTIVE: To evaluate the feasibility and safety of sodium fluorescein (Na-Fl)-guided surgery with the use of the PENTERO 900 surgical microscope (Carl Zeiss, Meditec, Oberkochen, Germany) equipped with the YELLOW-560-nm filter and low-dose Na-Fl (2 mg/kg) in pediatric brain tumor surgery. METHODS: The study included 23 pediatric patients with various intracranial pathologies, who underwent Na-Fl-guided surgery between April 2015 and February 2018. Clinical features, surgical observations, extent of resection, and tumor histopathology were retrospectively analyzed. The use of YELLOW-560-nm filter was found "helpful" if the discrimination of the pinkish brain tissue and bright yellow stained tumor tissue was clear. Otherwise, it was described as "not helpful." RESULTS: There were 11 female and 12 male patients with a mean age of 9.4 years. There were 7 brain stem/tectal plate gliomas, 6 supratentorial tumors, 4 intraventricular tumors, 2 pineal tumors, 2 infratentorial tumors, 1 clivus tumor, and 1 tumor with supra- and infratentorial extensions in the current series. Na-Fl was found helpful by means of the tumor demarcation in 20 instances (87%). In 11 of these 20 operations (55%), a total resection was achieved regardless of the tumor pathology. A subtotal resection was achieved in the remaining 9 patients (45%). No adverse events or side effects were encountered with regard to Na-Fl use. CONCLUSION: Na-Fl guidance with the use of the YELLOW-560 filter is safe and effective during brain tumor surgery in pediatric age group.

Life-threatening parkinsonism-hyperpyrexia syndrome following bilateral deep brain stimulation of the subthalamic nucleus.

Parkinsonism-hyperpyrexia syndrome (PHS), or neuroleptic malignant syndrome (NMS), is a neurophysiologic reaction to the acute withdrawal/decrease of central dopamine levels. It is a severe complication characterized by rigidity, change in consciousness level, fever, hypertension, and autonomic instability, that can be fatal. To the best of our knowledge, PHS following deep brain stimulation (DBS) of subthalamic nucleus (STN) surgery due to anti-Parkinson drug discontinuation has been previously reported only six times. Half of these cases resulted in fatalities. Herein, we report on an early diagnosed case of PHS following bilateral STN-DBS which was successfully treated with the administration of dopamine agonists, fluid replacement, and activation of DBS.

Fluorescein-Guided Resection of Intramedullary Spinal Cord Tumors: Results from a Preliminary, Multicentric, Retrospective Study.

BACKGROUND: Intramedullary spinal cord tumors (IMSCTs) are rare, heterogenous lesions that are usually enhanced on preoperative magnetic resonance imaging (MRI) because of a damaged blood-brain barrier. Sodium fluorescein is a dye that accumulates in areas of the central nervous system with a damaged BBB. Given the pattern of MRI contrast enhancement of the majority of IMSCTs, the use of this fluorescent tracer could improve tumor visualization and quality of resection. In this article, we present the first experience with the application of fluorescein-guided technique for surgical removal of IMSCTs. METHODS: Eleven patients (6 men, 5 women; mean age, 50.1 years), harboring 5 ependymomas, 3 hemangioblastomas, 1 astrocytoma, 1 pilocytic astrocytoma, and 1 glioneuronal tumor forming rosettes were included. Sodium fluorescein (5 mg/kg) was injected immediately after patient intubation. Tumors were removed with microsurgical technique and standard neurophysiological monitoring, under YELLOW 560 filter (Pentero 900) visualization. Surgical reports were reviewed regarding usefulness and grade of fluorescein staining. Postoperative MRI was performed within 72 hours after surgery, and postoperative clinical outcome was registered. RESULTS: No adverse events were registered. Fluorescent staining was reported in 9 of 11 cases (82%), all of them enhancing on preoperative MRI (100% of ependymomas, 100% of pilocytic astrocytomas, 100% of hemangioblastomas). No fluorescence was reported in 1 astrocytoma and 1 glioneuronal tumor-forming rosette. Intraoperative fluorescence was considered helpful for tumor resection in 9 of 11 cases (82%). Gross total resection was obtained in 8 of 11 cases (72.7%). CONCLUSIONS: Our results suggest that fluorescein-guided surgery is a safe and effective technique that can be used during the surgical resection of IMSCTs presenting with contrast-enhancement on preoperative MRI.

Use of Sodium Fluorescein in Meningioma Surgery Performed Under the YELLOW-560 nm Surgical Microscope Filter: Feasibility and Preliminary Results.

OBJECTIVE: To evaluate the feasibility of sodium fluorescein (Na-Fl)-guided surgery involving the use of the PENTERO 900 surgical microscope equipped with the YELLOW-560 nm filter and low-dose Na-FL (200 mg/2-4 mg/kg) in meningioma surgery. PATIENTS AND METHODS: The study included 30 patients with newly diagnosed or recurrent meningiomas who underwent Na-Fl-guided surgery between April 2015 and December 2016. Clinical features, surgical observations, extent of resection, and tumor histopathology were retrospectively analyzed. The Na-Fl enhancement pattern was assessed as "no enhancement," "diffuse homogenous enhancement," or "low heterogeneous enhancement." RESULTS: There were 30 meningiomas among the 30 patients. In 25 patients, Na-Fl was used for tumor demarcation, whereas in 5 patients, it was used for videoangiography. In this series, 88% of tumors showed diffuse homogeneous Na-Fl enhancement during the operation. The resection rate of the meningiomas was 87%. In 5 patients, in whom Na-Fl was used for videoangiography, the approach was useful to evaluate Na-Fl-stained vessels for patency and to understand their relationship with the tumor. No adverse events were encountered with regard to Na-Fl use. CONCLUSIONS: Na-Fl guidance with the use of the YELLOW-560 filter is safe and effective during meningioma surgery.

Effect of Visible Light on Vasospasticity of Post-Subarachnoid Hemorrhage Cerebrospinal Fluid.

Background and Objective Cerebral vasospasm (CV) is a serious complication of subarachnoid hemorrhage (SAH) with high morbidity and mortality rates. The mechanism of CV has not been determined. There are many theories related to this unsolved issue, one of which supports CV as a two-stage phenomenon from a pathophysiologic perspective. The first stage consists of inhibition of neuronal nitric oxide synthase by oxyhemoglobin, which results in a decrease of nitric oxide (NO) production. The second stage consists of an increase in the levels of asymmetric dimethylarginine through bilirubin oxidation products (BOXes), which are oxidized by-products of hemoglobin metabolism. These in turn inhibit endothelial nitric oxide synthase (eNOS), which results in the blockage of the second NO production mechanism. BOXes are sensitive to visible light, as is their precursor bilirubin. The hypothesis of CV prevention using the photosensitivity of BOXes was tested in this study. Material and Methods Cerebrospinal fluid (CSF) obtained from two patients with SAH was divided in half and either exposed to a standard dose of visible light or not exposed to any light. The CSF was spectrophotometrically investigated and the concentration of BOXes was measured. A comparison between CSF samples exposed to light and not exposed to light was made. Using two groups of 16 rats each, the vasospastic effect of the CSF exposed and not exposed to light on arteries of the cortical surface was measured. The cortex was exposed using the cranial window. Results Spectrophotometric analysis revealed that the concentration of BOXes in the CSF decreased significantly after being exposed to visible light (p < 0.001). There was a significant difference of the vasospastic effect of CSF on exposed cortical arteries (p < 0.001). Conclusion The concentration of BOXes and the vasospastic effect of CSF taken from patients with SAH were significantly reduced after being exposed to visible light if compared with CSF not exposed to light.

Clinical Course of Non-Traumatic Non-Aneurysmal Subarachnoid Hemorrhage: A Single Institution Experience over 10 Years and Review of the Contemporary Literature.

AIM: To report our experience with a relatively large series of patients with non-traumatic non-aneurysmal subarachnoid hemorrhage (NNSAH) to identify the prognosis associated with different bleeding patterns as well as a further diagnostic work-up to determine the underlying cause. MATERIAL AND METHODS: Between January 2004 and December 2014, 81 patients with angiography-negative non-traumatic subarachnoid hemorrhage (SAH) were treated at our institution. Diagnosis was confirmed with a typical history of spontaneous SAH and cranial computed tomography (CT) scan or lumbar puncture (LP). The patients were grouped according to the bleeding pattern on the CT scan: Group 1: Perimesencephalic (PM) SAH (n=33, 40.7%); Group 2: Non-perimesencephalic (nPM) SAH (n=41, 50.6%); and Group 3: CT-negative NNSAH (n=7, 8.6%). The clinical course, hospitalization period, and complications were noted. All patients underwent an initial four-vessel digital subtraction angiography (DSA). Cranial magnetic resonance imaging (MRI), repeat DSA investigations and spinal MRI were performed in all patients. RESULTS: The mean hospital stays were 6.3, 14.7 and 10.1 days for patient groups 1, 2, and 3, respectively. The mortality rate was 1.2% (1 patient) in our series. Repeat DSA investigations were positive in two patients (2.5%), both from Group 2 (4.9%). Cranial MRI revealed 100% negative results. Spinal MRI revealed positive results in three patients from Group 2 (7.3%). CONCLUSION: We suggest our diagnostic work-up for patients with nPM-SAH, namely repeat DSA and spinal MRI, until an evidence-based guideline is established for the patient management.

The use of the YELLOW 560 nm surgical microscope filter for sodium fluorescein-guided resection of brain tumors: Our preliminary results in a series of 28 patients.

OBJECTIVE: Sodium fluorescein (Na-Fl) is a fluorescent dye that accumulates in tumoral tissues via disrupted blood-brain barrier. It has been used in fluorescence-guided surgery for various brain tumors. Herein, we report our initial experience and preliminary results for the first 28 patients who were operated on under Na-Fl guidance with the use of a special filter on the surgical microscope. PATIENT AND METHODS: Between January and November 2015, 200 mg (2-4 mg/kg) of Na-Fl was administered in 28 patients (30 surgeries) after anesthesia induction. The clinical features, surgical observations, extent of resection on the postoperative magnetic resonance imaging (MRI) and histopathology of the tumors were retrospectively analyzed. The use of YELLOW 560 nm filter was found "helpful" if the discrimination of the pinkish brain tissue and bright yellow stained tumor tissue was clear. Otherwise, it was described as "not helpful. RESULTS: There were 23 high-grade and 7 metastatic tumors in our study group. Na-Fl was found helpful by means of the tumor demarcation in 29 of 30 operations (97%). In 23 of these 29 operations (79%), a total resection was achieved regardless of the tumor pathology. No adverse events were encountered regarding the use of Na-Fl. CONCLUSION: Na-Fl guidance with the use of a YELLOW 560 filter is safe and effective in high-grade glioma and metastatic tumor surgery. We think it is feasible for increasing the extent of resection in these tumors.

Fully endoscopic interlaminar and transforaminal lumbar discectomy: short-term clinical results of 163 surgically treated patients.

OBJECTIVE: To evaluate the clinical outcomes of patients with lumbar disc disease undergoing fully endoscopic surgery at a single clinic. METHODS: Between August 2009 and January 2012, 163 patients (74 men and 89 women) underwent fully endoscopic lumbar discectomy. All patients were followed for 1 year after surgery. The Oswestry Disability Index and a visual analog scale were used to analyze outcomes. RESULTS: During the follow-up period, 114 (70%) patients had no complaints, 30 (18%) patients had occasional pain, and 19 (12%) patients had no improvement. During postoperative follow-up, 8 patients required repeat surgery for recurrence or residual fragments. Postoperatively, 4 patients experienced dysesthesia, which completely resolved in time. Neurologic deterioration occurred in 5 patients, 4 of whom recovered completely without any intervention. Dural tears occurred in 6 patients. CONCLUSIONS: Fully endoscopic interlaminar or transforaminal surgeries are safe and effective treatment modalities for lumbar disc herniations. Despite the difficulties of acquiring this new technique, good results can be achieved with sufficient experience.