Peter Kurucz

BACKGROUND AND IMPORTANCE: Pure arterial malformations (PAMs) are rare vascular lesions with unknown natural history. Described in 2013 and initially considered benign, recent evidence of ruptured cases and progressive angioarchitectural changes may support the need for interventional treatment for selected patients. We present the first case of an accessory middle cerebral artery PAM successfully treated using a hybrid approach, including microsurgical revascularization and endovascular occlusion using Glubran2/Lipiodol.CLINICAL PRESENTATION: A 58-year-old woman with a history of spontaneous basal ganglia hemorrhage 2 years before presented to our clinic with a dilated, multilobulated, and overlapping lesion located at a dominant left accessory middle cerebral artery, compatible with the diagnostic criteria of a PAM. The lesion was near the previous bleeding site, and since perforating and cortical vessels arose from its distal lobule, a safeguarding superficial temporal artery-MCA bypass was considered necessary before the successful endovascular embolization of the malformation using nBCA (Glubran2/Lipiodol).CONCLUSION: PAMs can be associated with intracranial bleeding; thus, active treatment is warranted for selected patients. A hybrid microsurgical-endovascular approach is feasible and can be considered the optimal treatment for specific complex anatomies.

Background There is high risk of injury to the olfactory tract and olfactory bulb during surgery of the anterior cranial fossa. The goal of this study was to describe the outer arachnoid envelope around the olfactory bulb, which plays a significant role in approach-related injury of the nerve. Methods A total of 20 fresh human cadaveric heads were examined. Five cadaveric heads were used to describe a gross overview of the topographic anatomy of the outer arachnoid cover of the olfactory bulb. In 15 cadaveric heads, endoscopic surgical approaches were performed to examine the in situ undisrupted anatomy of the outer arachnoid around the olfactory bulb. Four cadaveric heads were used for the lateral subfrontal approach, 5 heads for the medial subfrontal approach, 3 heads for the median subfrontal approach, and 3 heads for the anterior interhemispheric approach. Results The outer arachnoid membrane of the frontal lobe attaches the olfactory bulb strongly to the above lying olfactory sulcus. Only the most rostral portion of the olfactory bulb became slightly detached from the frontal lobe. The outer arachnoid forms a decent protrusion around the tip of the olfactory bulbs. The fila olfactoria have their own outer arachnoid cover as a continuation of the same layer of the olfactory bulb. The effect of brain retraction and manipulation forces on the olfactory bulb and the role of the arachnoid membranes located here were visually analyzed and described in detail through the four different neurosurgical approaches we performed. Conclusion The results of our observations provide important anatomical details for preserving the sense of smell during neurosurgical procedures.

Spinal arachnoid web (SAW) is a rare disease entity characterized as band-like arachnoid tissue that can cause spinal cord compression and syringomyelia. This study aimed to analyze the surgical management of the spinal arachnoid web in patients with syringomyelia, focusing on surgical strategies and outcomes. A total of 135 patients with syringomyelia underwent surgery at our department between November 2003 and December 2022. All patients underwent magnetic resonance imaging (MRI), with a special syringomyelia protocol (including TrueFISP and CINE), and electrophysiology. Among these patients, we searched for patients with SAW with syringomyelia following careful analysis of neuroradiological data and surgical reports. The criteria for SAW were as follows: displacement of the spinal cord, disturbed but preserved CSF flow, and intraoperative arachnoid web. Patients were evaluated for initial symptoms, surgical strategies, and complications by reviewing surgical reports, patient documents, neuroradiological data, and follow-up data. Of the 135 patients, 3 (2.22%) fulfilled the SAW criteria. The mean patient age was 51.67 ± 8.33 years. Two patients were male, and one was female. The affected levels were T2/3, T6, and T8. Excision of the arachnoid web was performed in all cases. No significant change in intraoperative monitoring was noted. Postoperatively, none of the patients presented new neurological symptoms. The MRI 3 months after surgery revealed that the syringomyelia improved in all cases, and caliber variation of the spinal cord could not be detected anymore. All clinical symptoms improved. In summary, SAW can be safely treated by surgery. Even though syringomyelia usually improves on MRI and symptoms also improve, residual symptoms might be observed. We advocate for clear criteria for the diagnosis of SAW and a standardized diagnostic (MRI including TrueFISP and CINE).

Introduction The arachnoid membranes’ anatomy is a controversial topic in the literature, and the rhomboid membrane at the craniovertebral junction is an element of this system that has been described poorly. Hence, our study's objective was to examine this membrane's anatomy and histology. Materials and Methods 45 fresh formalin‐fixed human cadaveric heads were examined, and anatomic dissections and histologic examinations using standard staining methods were performed. Results The membrane was found to be a constant structure. It has a rhomboid shape and is located on the medulla oblongata and upper cervical spine's ventral surface within the subarachnoid space. Its average cranio‐caudal length is 49 mm and the short axis is 26 mm. The cranial apex is attached to the vertebral arteries' junction, and the caudal apex reaches the level of C4. The lateral apices are attached to the dura mater at the level of the denticulate ligament's second insertion. The C1 spinal nerves perforate the membrane, while the C2 roots are located dorsal to it. The membrane is attached strongly to the underlying pia mater. Histologically, it has a typical arachnoid structure, in which its adhesions to the vertebral arteries as well as to the pia mater could be verified histologically. Conclusions This is the first detailed examination of the rhomboid membrane. Our results suggest that the membrane serves a valve‐like function between the spinal and cranial subarachnoid spaces. Based on our findings, further hydrodynamic studies should clarify the membrane's physiologic role.

A 45-year-old male patient with reduced hearing in the right ear was diagnosed with a medium-sized (T3a) acoustic neuroma. The operation was performed through an individually tailored retrosigmoid mini-craniotomy. Endoscope-assisted microsurgical technique was applied to early detect the location of the facial and cochlear nerves as well as to look around the hidden corners during the surgery. The entire operation was performed without using brain retractors. The moderate intrameatal extension of the tumor and the use of angled endoscopes allowed to avoid the drilling of the internal auditory meatus. The lesion could be completely removed and the patient showed a satisfactory hearing recovery in the follow-up examinations 3 months after the surgery.The link to the video can be found at: https://youtu.be/dAYLakih924.