Optimized quantitative mapping of cardiopulmonary oscillations using hyperpolarized 129 Xe gas exchange MRI: Digital phantoms and clinical evaluation in CTEPH.

PURPOSE: The interaction between 129 Xe atoms and pulmonary capillary red blood cells provides cardiogenic signal oscillations that display sensitivity to precapillary and postcapillary pulmonary hypertension. Recently, such oscillations have been spatially mapped, but little is known about optimal reconstruction or sensitivity to artifacts. In this study, we use digital phantom simulations to specifically optimize keyhole reconstruction for oscillation imaging. We then use this optimized method to re-establish healthy reference values and quantitatively evaluate microvascular flow changes in patients with chronic thromboembolic pulmonary hypertension (CTEPH) before and after pulmonary thromboendarterectomy (PTE). METHODS: A six-zone digital lung phantom was designed to investigate the effects of radial views, key radius, and SNR. One-point Dixon 129 Xe gas exchange MRI images were acquired in a healthy cohort (n = 17) to generate a reference distribution and thresholds for mapping red blood cell oscillations. These thresholds were applied to 10 CTEPH participants, with 6 rescanned following PTE. RESULTS: For undersampled acquisitions, a key radius of 0.14 k max $$ 0.14{k}_{\mathrm{max}} $$ was found to optimally resolve oscillation defects while minimizing excessive heterogeneity. CTEPH participants at baseline showed higher oscillation defect + low (32 ± 14%) compared with healthy volunteers (18 ± 12%, p < 0.001). For those scanned both before and after PTE, oscillation defect + low decreased from 37 ± 13% to 23 ± 14% (p = 0.03). CONCLUSIONS: Digital phantom simulations have informed an optimized keyhole reconstruction technique for gas exchange images acquired with standard 1-point Dixon parameters. Our proposed methodology enables more robust quantitative mapping of cardiogenic oscillations, potentially facilitating effective regional quantification of microvascular flow impairment in patients with pulmonary vascular diseases such as CTEPH.

Analytical corrections for B1-inhomogeneity and signal decay in multi-slice 2D spiral hyperpolarized 129Xe MRI using keyhole reconstruction.

PURPOSE: Hyperpolarized xenon MRI suffers from heterogeneous coil bias and magnetization decay that obscure pulmonary abnormalities. Non-physiological signal variability can be mitigated by measuring and mapping the nominal flip angle, and by rescaling the images to correct for signal bias and decay. While flip angle maps can be calculated from sequentially acquired images, scan time and breath-hold duration are doubled. Here, we exploit the low-frequency oversampling of 2D-spiral and keyhole reconstruction to measure flip angle maps from a single acquisition. METHODS: Flip angle maps were calculated from two images generated from a single dataset using keyhole reconstructions and a Bloch-equation-based model suitable for hyperpolarized substances. Artifacts resulting from acquisition and reconstruction schemes (e.g., keyhole reconstruction radius, slice-selection profile, spiral-ordering, and oversampling) were assessed using point-spread functions. Simulated flip angle maps generated using keyhole reconstruction were compared against the paired-image approach using RMS error (RMSE). Finally, feasibility was demonstrated for in vivo xenon ventilation imaging. RESULTS: Simulations demonstrated accurate flip angle maps and B1-inhomogeneity correction can be generated with only 1.25-fold central-oversampling and keyhole reconstruction radius = 5% (RMSE = 0.460°). These settings also generated accurate flip angle maps in a healthy control (RSME = 0.337°) and a person with cystic fibrosis (RMSE = 0.404°) in as little as 3.3 s. CONCLUSION: Regional lung ventilation images with reduced impact of B1-inhomogeneity can be acquired rapidly by combining 2D-spiral acquisition, Bloch-equation-based modeling, and keyhole reconstruction. This approach will be especially useful for breath-hold studies where short scan durations are necessary, such as dynamic imaging and applications in children or people with severely compromised respiratory function.

Keyhole Aqueduct Syndrome.

Keyhole aqueduct syndrome is a rare progressive neurodegenerative disorder describing a unique set of neuro-ophthalmologic, neuroimaging, and histopathological findings on autopsy. A midline mesencephalic cleft communicating with the cerebral aqueduct resembling syrinx is seen on imaging and histopathology. There are 9 cases published in the literature. We encountered a patient with vertical nystagmus, internuclear ophthalmoplegia, and progressive ataxia who has a midline cleft connecting the cerebral aqueduct with the interpeduncular cistern highlighting a distinguishing feature of this syndrome.

Exploring optimal microscopic keyhole access to the skull base: an anatomical evaluation of transciliary supraorbital and transpalpebral orbitofrontal craniotomy approaches.

PURPOSE: The past two decades have witnessed the rise of keyhole microscopic minimally invasive surgeries, including the transciliary supraorbital approach (TCA) and transpalpebral approach (TPA), commonly known as the transorbital approach. This study aims to elucidate the nuances, specific indications, and advantages of each approach. METHODS: A series of dissections were conducted on five formalin-fixed, alcohol-preserved cadaver heads. The TCA was performed on one side, and the TPA on the other. Virtual measurements of working angles for both approaches were recorded. Additionally, three clinical cases were presented to illustrate the practical application of the techniques. RESULTS: For TCA, the craniotomy dimensions were 1.7 cm x 2.5 cm (Cranial-Caudal (CC) x Lateral-Lateral (LL)), while for TPA, they measured 2.1 cm x 2.9 cm (CC x LL). The measurements of anterior clinoid processes (ACP) were obtained and compared between approaches. In the TCA, the mean ipsilateral ACP measurement was 62 mm (Range: 61 -63 mm), and the mean contralateral ACP measurement was 71.2 mm (Range: 70 -72 mm). In TPA, these measurements were 47.8 mm (Range: 47 -49 mm) and 62.8 mm (Range: 62 -64 mm), respectively. TCA exhibited an average cranial-caudal angle of 14.9°, while TPA demonstrated an average of 8.3°. CONCLUSION: The anterior cranial fossa was better exposed by a TCA, which also featured shorter operative times, enhanced midline visualization, and a quicker learning curve. Conversely, the middle fossa was better exposed by a TPA, making it an excellent option for middle fossa pathologies, including those in the anterior temporal lobe. After sphenoid bone wing drilling, the TPA offers superior visualization from the lateral to the medial aspect and enhances the CC angle. Additionally, the TPA reduces the risk of postoperative frontalis palsy based on anatomic landmarks. However, the TPA requires a greater cranial osteotomy, and due to unfamiliarity with eyelid anatomy, the learning curve for most neurosurgeons is lengthier for this procedure.

Anterolateral keyhole transorbital routes to the skull base: a comparative anatomical study.

OBJECTIVE: Although keyhole transorbital approaches are gaining traction, their indications have not been adequately studied comparatively. In this study the authors have defined them also as transwing approaches-meaning that they use the different facies of the sphenoid wing for cranial entry-and sought to compare the four major ones: 1) lateral orbitocraniotomy through a lateral canthal incision (LatOrb); 2) modified orbitozygomatic approach through a palpebral incision (ModOzPalp); 3) modified orbitozygomatic approach through an eyebrow incision (ModOzEyB); and 4) supraorbital craniotomy through an eyebrow incision (SupraOrb), coupled with its expanded version (SupraTransOrb). METHODS: Cadaveric dissections were performed at the neuroanatomy lab. To delineate the skull base exposure, four formalin-fixed heads were used, with two sides dedicated to each approach. The outer limits were assessed via image guidance and were mapped and illustrated accordingly. A fifth head was dissected purely endoscopically, just to facilitate an overview of the transwing concept. Qualitative features were also rigorously examined. RESULTS: The LatOrb proves to be more versatile in the middle cranial fossa (MCF), whereas the anterior cranial fossa (ACF) exposure is limited to a small area above the sphenoid ridge. An anterior clinoidectomy is possible; however, the exposure of the roof of the optic canal is suboptimal. The ModOzPalp adequately exposes both the ACF and MCF. Its lateral trajectory allows the inferior to superior view, yet there is restricted access to the medial anterior skull base (olfactory groove). The ModOzEyB also provides extensive exposure of the ACF and MCF, but has a more superior to inferior trajectory compared to the ModOzPalp, making it more appropriate for pathology reaching the medial anterior skull base or even the contralateral side. The anterior clinoidectomy is performed with improved visualization of the optic canal. The SupraOrb provides mainly anterior cranial base exposure, with minimal middle fossa. An anterior clinoidectomy can be performed, but without any direct observation of the superior orbital fissure. Some MCF access can be accomplished if the lateral sphenoid wing is drilled inferiorly, leading to its highly versatile variant, the SupraTransOrb. CONCLUSIONS: All the aforementioned approaches use the sphenoid wing as skull base corridor from a specific orientation point; hence these are designated as transwing approaches. Their peculiarities mandate careful case selection for the effective and safe completion of the surgical goals.

Surgical management of parastomal hernia following radical cystectomy and ileal conduit: A french multi-institutional experience.

BACKGROUND: Parastomal incisional hernia (PH) is a frequent complication following the creation of an ileal conduit (IC), and it can be a significant detriment to quality of life. The aim of this study was to evaluate outcomes of PH repair following IC for urinary diversion. METHOD: A multicenter retrospective study was conducted of 6 academic hospitals in France. The study's population included patients who underwent surgical treatment for parastomal hernia following IC creation from 2013 to 2021. RESULTS: Fifty-one patients were included in the study. Median follow up was 15.3 months. Eighteen patients presented with a recurrence (35%), with a median time to recurrence of 11.1 months. The vast majority of PH repair was performed through an open approach (88%). With regard to technique, Keyhole was the most reported technique (46%) followed by Sugarbaker (22%) and suture only (20%). The Keyhole technique was associated with a higher risk of recurrence compared to the Sugarbaker technique (52% vs 10%, p = 0.046). Overall, there was a 7.8% rate of major complications without a statistical difference between PH repair techniques for major complications. CONCLUSION: Surgical treatment of parastomal hernia following IC was associated with a high risk of recurrence. Novel surgical approaches to PH repair should be considered.

Laparoscopic parastomal hernia repair: keyhole, Sugarbaker, sandwich, or hybrid technique with 3D mesh? An updated systematic review and meta-analysis.

PURPOSE: Parastomal hernia is the most common complication after stoma formation with an incidence that approaches 50% at 2 years postoperatively. In the last decade, different approaches of minimally invasive procedures have been proposed for the treatment of parastomal hernia. Nevertheless, the superiority of one technique over the others remains still unclear. Our objective was to update and systematically analyze current state of research concerning the postoperative outcomes of the four most prevalent minimally invasive techniques. METHODS: A systematic literature search of three databases (Medline, Scopus, Google Scholar) was undertaken for articles published from January 2015 to November 2022. Fifteen studies from a previous meta-analysis on the topic were included. RESULTS: Thirty-three studies incorporating 1289 total patients were deemed eligible for inclusion in the final analysis. The keyhole technique was associated with the highest incidence of postoperative complications and recurrences (31.3% and 24.1%, respectively), followed by the Sugarbaker technique (27.6% and 9%, respectively). Operative time was among the lowest in patients operated with the 3D mesh technique, while patients undergoing the keyhole technique experienced the shortest cumulative length of hospital stay (6 days). CONCLUSION: Each technique demonstrates a unique profile of effectiveness offset by the propensity towards developing postoperative complications. While no conclusive evidence on the optimal technique exist to date, newer minimally invasive techniques show promising results, albeit based on limited data. The future of parastomal hernia repair seems to rely on a highly individualized approach, tailored to the distinctive characteristics of both the hernia and the patient.

Applications of supraorbital keyhole craniotomy in pediatric cranial trauma: illustrative series of two cases and systematic literature review.

Minimally invasive (MIS) approaches to neurosurgical diseases continue to increase in popularity due to their association with decreased infection risk, shorter recovery time, and improved cosmesis. Cosmesis and lower morbidity are especially important for pediatric patients. The supraorbital keyhole craniotomy (SOKC) is one MIS approach shown to be effective for both neoplastic and vascular pathologies in pediatric patients. However, it is limited data on its use in pediatric trauma patients. Two cases employing SOKC in pediatric trauma patients are presented here along with a systematic review of the literature. We queried PubMed, Scopus, and Web of Science databases from inception to August 2022 using the Boolean search term: (supraorbital OR eyebrow OR transeyebrow OR suprabrow OR superciliary OR supraciliary) AND (craniotomy OR approach OR keyhole OR procedure) AND (pediatric OR children OR child OR young) AND "trauma". Studies that discussed the use of an SOKC in a pediatric patient having sustained trauma to the frontal calvarium and/or anterior fossa/sellar region of the skull base were included. Details were extracted on patient demographics, trauma etiology, endoscope use, and surgical and cosmetic outcomes. We identified 89 unique studies, of which four met inclusion criteria. Thirteen total cases were represented. Age and sex were reported for 12 patients, 25% of whom were male; the mean age was 7.5 years (range: 3-16). Pathologies included acute epidural hematoma (9), orbital roof fracture with dural tear (1), blowout fracture of the medial wall of the frontal sinus with supraorbital rim fracture (1), and compound skull fracture (1). Twelve patients were treated with a conventional operating microscope, while one underwent endoscope-assisted surgery. Only one significant complication (recurrent epidural hematoma) was reported. There were no reported cosmetic complications. The MIS SOKC approach is a reasonable option for select anterior skull base trauma in the pediatric population. This approach has been used previously for successful frontal epidural hematoma evacuation, which is often treated by a large craniotomy. Further study is merited.

Tension pneumocephalus in a patient with NF1 following ventriculoperitoneal shunt-deciphering the cause and proposed management strategy.

INTRODUCTION: Spontaneous pneumocephalus following ventriculoperitoneal shunting is a very unique complication, seen in a handful of patients. Small bony defects form as a result of chronically raised intracranial pressure, which can later lead to pneumocephalus once intracranial pressure decreases following ventriculoperitoneal shunting. CASE REPORT: Here, we present a case of a 15-year-old girl with NF1 who presented to us with pneumocephalus 10 months following shunting and our management strategy along with a literature review of this condition. CONCLUSION: NF1 & hydrocephalus can lead to skull base erosion, which needs to be looked up before proceeding with VP shunting to avoid delayed onset pneumocephalus. SOKHA with the opening of LT is a minimally invasive approach suitable to tackle both problems simultaneously.

Supraorbital eyebrow approach and pterional approach in surgical treatment of ruptured and unruptured aneurysms: a propensity score-matched analysis.

The aim of this study is to reveal efficacy and efficiency of the supraorbital eyebrow approach (SEA) in clipping ruptured and unruptured aneurysms where both SEA and pterional approach (PA) are considered feasible by comparing SEA and PA using propensity score matching. A total of 229 patients who underwent surgical clipping of an aneurysm from 2013 to 2022 and met inclusion criteria were recruited in the study. A study group of 67 patients treated via the SEA and a comparison group of 162 patients treated via the PA were formed. Then, the subgroups of 66 patients each, with balanced incoming factors, were analyzed using the propensity score technique. The safety and efficacy endpoints were compared. Successful clipping was achieved in all cases of both groups. There were no patients in the SEA group who required conversion to the standard craniotomy. There were no procedure-related deaths in this series. No patient experienced early or late rebleeding in either group. Mean blood loss volume in the SEA group was lower than in the PA group by approximately 77.5 ml (p < 0.001). There were favorable differences in the SEA group regarding postoperative neurological deficit (p = 0.016), postoperative epileptic seizure rate (p = 0.013), ischemic and hemorrhagic complications (p = 0.028 and 0.0009, respectively), and outcomes (p < 0.001). Patients' satisfaction with cosmetic results measured by the visual analog scale was rated highly in both groups (p = 0.081). For patients where SEA provides adequate exposure, it results in safety and cosmetic outcomes not inferior to the PA.

Minimally invasive surgical evacuation for spontaneous cerebellar hemorrhage: a case series and systematic review.

Spontaneous cerebellar hemorrhage (scICH) is a subset of intracerebral hemorrhage accounting for 5-10% of all cases. Despite potential advantages, minimally invasive surgical evacuation of scICH may be an underutilized strategy when compared to unilateral or bilateral large suboccipital craniectomy or craniotomy, with or without duraplasty. We performed a retrospective single-center cohort study and a systematic literature review. Radiographic and clinical data were recorded and analyzed. Five consecutive patients with minimally invasive surgical evacuation of scICH were identified. Average hematoma size was 16.4 ± 3.0 cm3. Mean Glasgow coma score (GCS) prior to surgery was 11.6 ± 3.0 with improvement to 14.6 ± 0.4 postoperatively. Mean hematoma evacuation was 92.6 ± 0.6% as confirmed by postoperative computed tomography (CT) imaging. All patients achieved a modified Rankin Scale (mRS) score of 0 or 1 with an average follow-up time of 31 ± 22 months. Mean length of hospital stay was 8.8 ± 3.0 days. No patients experienced significant complications or required reoperation. Systematic review revealed similar results for minimally invasive evacuation of scICH when reporting disaggregated outcomes. A review of recent studies utilizing large unilateral or bilateral suboccipital craniectomy or craniotomy, with or without duraplasty, revealed higher morbidity and mortality rates than minimally invasive surgical evacuation of scICH. Minimally invasive evacuation of scICH is safe and effective. Near complete evacuation of hematoma can be achieved with lower morbidity and mortality than large suboccipital craniectomy or craniotomy. A multi-center, prospective, and rigorous trial comparing the two strategies for evacuation of scICH is warranted.

Supraorbital Keyhole Versus Pterional Approach: A Morphometric Anatomical Study.

OBJECTIVE: Although the supraorbital (SO) keyhole approach has a wide range of indications, its routine usefulness with the advance of current technology has not been fully evaluated. In an attempt to address this issue, a cadaveric morphometric analysis to the supra- and parasellar regions was performed, comparing the standard Pterional craniotomy (PT) with the SO keyhole. METHODS: ETOH-fixed and silicone-injected human cadaveric heads were used. SO (n = 8) and PT craniotomies (n = 8) were performed. Pre- and post-dissection CT, along with pre-dissection MRI scans were also completed for neuro-navigation purposes, aimed to verify predetermined anatomical landmarks selected for morphometric analysis. RESULTS: Notwithstanding the smaller craniotomy, the SO approach allowed optimal anatomical exposure when compared to the PT approach. With 30° of head rotation, the SO keyhole showed a wider surgical field of the suprasellar region. CONCLUSIONS: Using detailed preoperative image-guided surgical planning, the SO keyhole approach offered an appropriate alternative route to the supra- and parasellar regions, compared to the PT craniotomy.

Novel freehand frontal ventriculostomy in the supraorbital keyhole approach: technical note.

BACKGROUND AND OBJECTIVES: The narrow surgical passage provided by the supraorbital keyhole craniotomy restricts the instrument's maneuverability and presents a number of technical challenges. Inadequate brain relaxation may eventually result in unavoidable brain retraction and neurological impairments. The article aims to provide a novel intraoperative ventriculostomy to assist in overcoming the barrier of a narrow surgical corridor and assess its feasibility and safety compared to other techniques. METHODS: The craniometric point was planned on one normal computed tomography (CT) brain. The coordinates were verified on 43 magnetic resonance imaging (MRI) brain images uploaded on the neuronavigation system (StealthStation S8 version 1.0; Medtronic, Louisville, USA). The ventriculostomy point was 3 cm superior to glabella, 2 cm lateral to midline, 6 cm deep to the brain surface in the perpendicular direction, and parallel to the floor of the anterior cranial fossa. Subsequently, the abovementioned radiologically calculated ventriculostomy trajectory was confirmed on 32 consecutive patients (without neuronavigation) of suprasellar mass undergoing supraorbital craniotomy between February 2022 and April 2023. The technical issues, feasibility, and outcomes were assessed. RESULTS: Out of 32 patients, in 29 patients, ventricular hit was attained in a single attempt, and the rest 3 patients needed two attempts. The intraoperative ventricular hit rate was 100% with 90.6% success in a single attempt. No ventriculostomy-related complications occurred. Compared to ELD (external lumbar drainage), performing an intraoperative ventriculostomy had no discernible difference in the perception of the brain retraction force. Intraoperative ventriculostomy fully eliminated the low back pain or radiculopathy that patients with ELD rarely have even after drain removal. CONCLUSION: The novel intraoperative frontal ventriculostomy is a safe trajectory and is a valid alternative to Menovsky's ventriculostomy or external lumbar drainage. The authors recommend this technique be generally utilized in supraorbital keyhole approaches to optimize brain relaxation and minimize secondary adverse events.

How I do it: Endoscopic microvascular decompression for a nerve penetrating trigeminocerebellar artery causing trigeminal neuralgia.

BACKGROUND: The trigeminocerebellar artery is a standard variant originating from the basilar artery and can be an infrequent cause of trigeminal neuralgia. METHOD: Total endoscopic microvascular decompression (eMVD) was performed using a 0-degree endoscope through a retro sigmoid keyhole. Multiple points of neurovascular conflict enhanced by indocyanine green angiography were identified, and the root entry zone was decompressed. The patient had an improvement in facial pain with no complications. CONCLUSION: Complete eMVD for a nerve-penetrating artery is a practical, minimally invasive, uncomplicated technique that improves visualization and patient comfort.

How we do it: the double keyhole micro-endoscopic combined complex pituitary adenoma surgery.

BACKGROUND: Surgical removal of complex pituitary adenomas (PA) is a technically challenging procedure. To ensure safe and efficient surgery, we employ the micro-endoscopic combination technique. METHOD: In this study, we present our approach to the removal of a complex PA using the micro-endoscopic combination strategy. We describe our surgical setup and workflow in detail. CONCLUSION: Our experience with this case highlights the effectiveness of the micro-endoscopic combination technique in the management of complicated skull base surgeries with good teamwork and cooperation.

Radical resection of intracavernous chondrosarcoma using an intradural keyhole approach: how I do it.

BACKGROUND: Skull base chondrosarcoma is rare, arising from the clivus or petroclival junction, and usually presents as ocular motility disorders. Endonasal transsphenoidal surgery may be performed in some cases of midline clivus chondrosarcoma. Chondrosarcoma is located within the cavernous sinus and presents a softer/gelatinous mass and can be removed with suctions and curettage. We have been using a simple intradural keyhole transcavernous approach, avoiding a complex extradural transcavernous dissection. METHODS: The intracavernous chondrosarcoma was removed via a 5 mm keyhole opening over the Parkinson's triangle using a standard frontotemporal intradural approach. CONCLUSION: Minimally invasive keyhole surgical resection can be performed to eradicate skull base chondrosarcomas, avoiding complex extradural cranial base approaches.

Contralateral supraorbital eyebrow approach for tuberculum sellae meningioma.

BACKGROUND: The main challenge in tuberculum sellae meningioma (TSM) resection is the safe dissection of the optic nerves, which many a times are compressed and distorted by the tumor. While intuitive, an approach from the side of predominant tumor extension makes tumor dissection from the medial surface of the ipsilateral optic nerve rather blind. We describe here a contralateral supraorbital eyebrow approach (c-SEA) to address this "blind spot." METHOD: c-SEA was performed using a 2 × 2 cm craniotomy. The patient improved after surgery and postoperative imaging confirmed the totality of the tumor resection. CONCLUSION: c-SEA can be an excellent minimally invasive option for asymmetric TSM.

Paraclinoid aneurysms clipping through an extradural sphenoid ridge keyhole approach.

BACKGROUND: Paraclinoid aneurysms represent a challenge for neurosurgeons due to the anatomical complexity of this region. Then, innovative techniques such as the extradural sphenoid ridge approach are suitable for a safe microsurgical clipping. METHOD: A description of the surgical technique was made by the senior author, a vascular neurosurgeon experienced with the use of this approach in the management of paraclinoid aneurysms exemplified through a clinical case. CONCLUSION: Microsurgical clipping through an extradural sphenoid ridge keyhole approach for small and midsize paraclinoid aneurysms is an excellent treatment modality with good clinical and surgical results.

Outcomes and complications of cerebral aneurysms operated on by eyebrow incision according to aneurysm type and location.

OBJECTIVE: Trans-eyebrow supraorbital aneurysmal neck clipping, also known as keyhole surgery, have many advantages of minimal invasive surgery. However, there are few studies on whether there is a difference in keyhole surgery according to the location of the aneurysm, and how the complications after keyhole approach differ from the conventional approach. The authors investigated the surgical outcome of keyhole aneurysmal surgery for clarify the characteristics of keyhole surgery. METHODS: A retrospective study was performed with review of medical records and images of patients with anterior circulation aneurysm undergoing aneurysmal clipping with keyhole surgery. The patient's clinical condition, imaging, surgical condition, and outcome were investigated. RESULTS: As a result of analysis about the location of the aneurysm, middle cerebral artery (MCA) aneurysm group had a longer operation time than internal carotid artery and anterior cerebral artery aneurysm groups, but there was no significant difference in complication rate. The olfactory dysfunction occurred more than that of conventional surgery and occurred less in MCA aneurysm group than others. Scalp sensory change in the surgical site was more common in patients with unruptured aneurysms. CONCLUSION: By accurately investigating the frequency and severity of complications associated with trans-eyebrow aneurysmal neck clipping surgery, it can help to select a surgical approach considering risk versus benefit. In addition, patient's satisfaction can be increased by providing information to patients and caregivers in advance about the outcome of this approach and the anticipated complications.

Brain abscess caused by Parvimonas micra: A rare case report and literature review.

Brain abscesses mostly develop due to direct infection caused by a nearby infectious lesion or hematogenous spread and are rarely caused by an odontogenic infection. We report a 47-year-old woman who presented with high fever, disturbed consciousness, headache, and neck pain. Imaging studies revealed a ring-shaped enhanced mass in the left frontal lobe causing a mass effect and midline shift. Magnetic resonance spectroscopy revealed a peak alanine concentration of 1.5 ppm. Supraorbital keyhole surgery with abscess removal was performed, and a bacterial culture confirmed a diagnosis of Parvimonas micra infection. After undergoing 6-week antibiotic treatment, the patient's symptoms resolved completely. No recurrence of abscess was observed during the follow-up period. Although brain abscess caused by P. micra has rarely been reported, an odontogenic origin should be investigated, especially when a patient has a history of periodontal infection or tooth extraction.