Major Internal Carotid Artery Injury During Endoscopic Skull Base Surgery: Case Report

Major vascular structures are always at risk during complex skull base surgery, particularly with use of the endoscopic endonasal approach, and intraoperative damage of the internal carotid artery (ICA) can be a devastating complication. Herein, we report a case of a young patient who had a major injury of the left ICA during endoscopic resection of a recurrent petrous bone chordoma. Massive bleeding was controlled by a Foley balloon inserted and kept in the resection area. Urgent angiography revealed a persistent leak from the petrous segment of the left ICA, and the vessel was sacrificed with coiling, since a balloon occlusion test showed good collateral blood flow. The patient woke up from anesthesia without a neurological deficit. Salvage resection of recurrent skull base neoplasms deserves specific attention because of the possibility of major vascular damage. In cases of intraoperative ICA injury, its management requires immediate decisions, and the available possibilities for endovascular therapy should always be considered.

The Quadrangular Space, Endonasal Access to the Meckel Cave: Technical Considerations and Clinical Series

OBJECTIVE

An anteromedial corridor via an expanded endoscopic endonasal approach to the Meckel cave (MC) was described more than a decade ago. However, few clinical series or endoscopic endonasal technical contributions exist concerning this type of approach to this complex region.

METHODS

We present a detailed description of the surgical technique for this approach reviewing the original technique and adding clarifying conceptual notions. We conducted a multicenter retrospective study selecting patients who underwent endonasal endoscopic surgery for lesions exclusively limited to the MC in the past 6 years. Intraoperative and postoperative complications were analyzed. The study of 10 cadaveric specimens provides additional information.

RESULTS

We performed a fully endoscopic anteromedial corridor to the MC in 18 patients. The most prevalent pathologic finding was schwannoma of the V nerve in 4 patients. Sixth cranial nerve palsy (13 patients) and trigeminal dysfunction (10 patients) were the predominant preoperative clinical signs. There were no remarkable intraoperative complications. Corneal keratopathy caused by dry eye syndrome affected 3 patients and V2 residual neuralgia appeared postoperatively in 2 patients. Six patients recovered from sixth cranial nerve palsy, and 2 showed improvement in preoperatively referred facial pain.

CONCLUSIONS

The front door to the MC via the endonasal anteromedial corridor could be a good option. Understanding of the anatomy and the concept of the quadrangular space is crucial to performing this technique safely, which has few complications in experienced hands. Recovery from sixth nerve palsy is possible with this approach. Corneal keratopathy in these patients is a potential complication.

Graphene Oxide and Reduced Derivatives, as Powder or Film Scaffolds, Differentially Promote Dopaminergic Neuron Differentiation and Survival

Emerging scaffold structures made of carbon nanomaterials, such as graphene oxide (GO) have shown efficient bioconjugation with common biomolecules. Previous studies described that GO promotes the differentiation of neural stem cells and may be useful for neural regeneration. In this study, we examined the capacity of GO, full reduced (FRGO), and partially reduced (PRGO) powder and film to support survival, proliferation, differentiation, maturation, and bioenergetic function of a dopaminergic (DA) cell line derived from the mouse substantia nigra (SN4741). Our results show that the morphology of the film and the species of graphene (GO, PRGO, or FRGO) influences the behavior and function of these neurons. In general, we found better biocompatibility of the film species than that of the powder. Analysis of cell viability and cytotoxicity showed good cell survival, a lack of cell death in all GO forms and its derivatives, a decreased proliferation, and increased differentiation over time. Neuronal maturation of SN4741 in all GO forms, and its derivatives were assessed by increased protein levels of tyrosine hydroxylase (TH), dopamine transporter (DAT), the glutamate inward rectifying potassium channel 2 (GIRK2), and of synaptic proteins, such as synaptobrevin and synaptophysin. Notably, PRGO-film increased the levels of Tuj1 and the expression of transcription factors specific for midbrain DA neurons, such as Pitx3, Lmx1a, and Lmx1b. Bioenergetics and mitochondrial dysfunction were evaluated by measuring oxygen consumption modified by distinct GO species and were different between powder and film for the same GO species. Our results indicate that PRGO-film was the best GO species at maintaining mitochondrial function compared to control. Finally, different GO forms, and particularly PRGO-film was also found to prevent the loss of DA cells and the decrease of the α-synuclein (α-syn) in a molecular environment where oxidative stress has been induced to model Parkinson's disease. In conclusion, PRGO-film is the most efficient graphene species at promoting DA differentiation and preventing DA cell loss, thus becoming a suitable scaffold to test new drugs or develop constructs for Parkinson's disease cell replacement therapy.

Global neurosurgery: the current capacity and deficit in the provision of essential neurosurgical care. Executive Summary of the Global Neurosurgery Initiative at the Program in Global Surgery and Social Change

OBJECTIVE

Worldwide disparities in the provision of surgical care result in otherwise preventable disability and death. There is a growing need to quantify the global burden of neurosurgical disease specifically, and the workforce necessary to meet this demand.

METHODS

Results from a multinational collaborative effort to describe the global neurosurgical burden were aggregated and summarized. First, country registries, third-party modeled data, and meta-analyzed published data were combined to generate incidence and volume figures for 10 common neurosurgical conditions. Next, a global mapping survey was performed to identify the number and location of neurosurgeons in each country. Finally, a practitioner survey was conducted to quantify the proportion of disease requiring surgery, as well as the median number of neurosurgical cases per annum. The neurosurgical case deficit was calculated as the difference between the volume of essential neurosurgical cases and the existing neurosurgical workforce capacity.

RESULTS

Every year, an estimated 22.6 million patients suffer from neurological disorders or injuries that warrant the expertise of a neurosurgeon, of whom 13.8 million require surgery. Traumatic brain injury, stroke-related conditions, tumors, hydrocephalus, and epilepsy constitute the majority of essential neurosurgical care worldwide. Approximately 23,300 additional neurosurgeons are needed to address more than 5 million essential neurosurgical cases-all in low- and middle-income countries-that go unmet each year. There exists a gross disparity in the allocation of the surgical workforce, leaving large geographic treatment gaps, particularly in Africa and Southeast Asia.

CONCLUSIONS

Each year, more than 5 million individuals suffering from treatable neurosurgical conditions will never undergo therapeutic surgical intervention. Populations in Africa and Southeast Asia, where the proportion of neurosurgeons to neurosurgical disease is critically low, are especially at risk. Increasing access to essential neurosurgical care in low- and middle-income countries via neurosurgical workforce expansion as part of surgical system strengthening is necessary to prevent severe disability and death for millions with neurological disease.

Familial isolated pituitary adenoma caused by a Aip gene mutation not described before in a family context

The cause of familial isolated pituitary adenomas (FIPA) remains unknown in a high percentage of cases, but the AIP gene plays an important role in the etiology. The aim of the study is to describe a family with FIPA syndrome and the results of genomic studies. A 16-year-old man had a giant prolactinoma resistant tomedical treatment with delayed growth and pubertal development. His mother had been previously diagnosed with a nonfunctioning pituitary macroadenoma. Transsphenoidal endoscopic resection was performed and a genetic study revealed a heterozygous mutation in exon 6: 974G>A (p.Arg325Gln). Because the AIP gene is a tumor suppressor gene, we searched for loss of heterozygosity within the AIP gene by amplifying exon 6 from tumor tissue of the patient. In the electropherogram, only the A allele was amplified (hemizygous state), indicating loss of the normal allele. We report a Spanish family with FIPA in whom a mutation in the AIP gene previously unreported in a familiar context was identified.

[The preservation of hearing in surgery for acoustic neurinoma]

The surgical result in one patient with unilateral tumor of the cerebellopontine angle and internal auditory canal is presented. Total tumor removal and preservation of hearing was possible in spite of the size of the tumor. The authors make some considerations about the possibility to preserve a useful hearing in patients with this type of tumors.