Prevedello, Daniel M.

Abstract Alpha-gal syndrome (AGS) is an immunoglobulin E–mediated hypersensitivity to galatcose-alpha-1,3-galactose (alpha-gal), a carbohydrate compound present in nonprimate mammalian products. Initial exposure to alpha-gal most often occurs through a tick bite, most commonly the lone star tick in the United States. Repeated exposure to alpha-gal may elicit severe allergic reactions, including anaphylaxis. The allergy restricts dietary intake and may significantly impact perioperative risk, as many medications, anesthetics, and intraoperative surgical products utilize bovine or porcine-derived agents, including those containing magnesium stearate, glycerol, and gelatin. Here, we review the perineurosurgical care of two individuals with AGS and highlight pertinent clinical practices and perioperative management of these patients.

BACKGROUND AND OBJECTIVES: Lesions located in the retrosellar region, interpeduncular cistern, and petroclival region are among the most difficult to access in neurosurgery. Transcranial approaches are useful; however, the large distance between the surgeon and the lesion as well as the presence of major neurovascular structures surrounding the lesion may limit surgical exposure. A midline transsphenoidal route avoids transgression of the neurovascular plane and provides direct access to the interpeduncular cistern. To safely access the interpeduncular fossa, it requires mobilization of the pituitary gland. The pituitary hemitransposition technique permits mobilization of the gland, while preserving its venous drainage and arterial supply to the gland on one of its sides, preserving gland function. The authors aim to describe the intradural pituitary hemitransposition technique and to demonstrate its safe application for resection of skull base tumors in the retrosellar space. METHODS: The authors describe the surgical technique and illustrate its application in 5 cases of different types of skull base tumors, including a video demonstrating all the steps to perform this approach. In addition, the authors discuss the advantages and limitations of this technique compared with other approaches to the retrosellar space. RESULTS: The intradural pituitary hemitransposition technique was used to safely resect a chondrosarcoma, chordoma, craniopharyngioma, teratoma, and meningioma involving the parasellar and retrosellar spaces, while minimizing endocrine morbidity. We had one patient with mild, albeit permanent hyperprolactinemia and hypothyroidism after surgery. No other patients had permanent dysfunction related to surgery. CONCLUSION: The endonasal endoscopic intradural pituitary hemitransposition approach is an effective technique for resection of lesions located within the retrosellar and petroclival regions, allowing adequate exposure while potentially optimizing the preservation of the pituitary function.

Abstract Background Patients with relapsed intracranial germinoma can achieve durable remission with standard chemotherapy regimens and/or reirradiation; however, innovative therapies are required for patients with relapsed and/or refractory intracranial nongerminomatous germ cell tumors (NGGCTs) due to their poor prognosis. Improved outcomes have been reported using reinduction chemotherapy to achieve minimal residual disease, followed by marrow-ablative chemotherapy (HDCx) with autologous hematopoietic progenitor cell rescue (AuHPCR). We conducted a phase II trial evaluating the response and toxicity of a 3-drug combination developed for recurrent intracranial germ cell tumors consisting of gemcitabine, paclitaxel, and oxaliplatin (GemPOx). Methods A total of 9 patients with confirmed relapsed or refractory intracranial GCT were enrolled after signing informed consent, and received at least 2 cycles of GemPOx, of which all but 1 had relapsed or refractory NGGCTs. One patient with progressive disease was found to have pathologically confirmed malignant transformation to pure embryonal rhabdomyosarcoma (without GCT elements), hence was ineligible and not included in the analysis. Patients who experienced sufficient responses proceeded to receive HDCx with AuHPCR. Treatment response was determined based on radiographic tumor assessments and tumor markers. Results A total of 7 patients achieved sufficient response and proceeded with HDCx and AuHPCR, and 5 subsequently received additional radiotherapy. A total of 2 patients developed progressive disease while receiving GemPOx. Myelosuppression and transaminitis were the most common treatment-related adverse events. With a mean follow-up of 44 months, 4 patients (3 NGGCTs, 1 germinoma) are alive without evidence of disease. Conclusions GemPOx demonstrates efficacy in facilitating stem cell mobilization, thus facilitating the feasibility of both HDCx and radiotherapy.

Abstract Introduction Meningiomas—the most common extra-axial tumors—are benign, slow-growing dural-based lesions that can involve multiple cranial fossae and can progress insidiously for years until coming to clinical attention secondary to compression of adjacent neurovascular structures. For complex, multicompartmental lesions, multistaged surgeries have been increasingly shown to enhance maximal safe resection while minimizing adverse sequela. Here, we systematically review the extant literature to highlight the merits of staged resection. Methods PubMed, Scopus, and Web of Science databases were queried to identify articles reporting resections of intracranial meningiomas using a multistaged approach, and articles were screened for possible inclusion in a systematic process performed by two authors. Results Of 118 identified studies, 36 describing 169 patients (mean age 42.6 ± 21.3 years) met inclusion/exclusion criteria. Petroclival lesions comprised 57% of cases, with the most common indications for a multistaged approach being large size, close approximation of critical neurovascular structures, minimization of brain retraction, identification and ligation of deep vessels feeding the tumor, and resection of residual tumor found on postoperative imaging. Most second-stage surgeries occurred within 3 months of the index surgery. Few complications were reported and multistaged resections appeared to be well tolerated overall. Conclusions Current literature suggests multistaged approaches for meningioma resection are well-tolerated. However, there is insufficient comparative evidence to draw definitive conclusions about its advantages over an unstaged approach. There are similarly insufficient data to generate an evidence-based decision-making framework for when a staged approach should be employed. This highlights the need for collaborative efforts among skull base surgeons to establish an evidentiary to support the use of staged approaches and to outline those indications that merit such an approach.

Background Endoscopic skull‐base surgery (ESBS) is employed in the management of diverse skull‐base pathologies. Paralleling the increased utilization of ESBS, the literature in this field has expanded rapidly. However, the rarity of these diseases, the inherent challenges of surgical studies, and the continued learning curve in ESBS have resulted in significant variability in the quality of the literature. To consolidate and critically appraise the available literature, experts in skull‐base surgery have produced the International Consensus Statement on Endoscopic Skull‐Base Surgery (ICAR:ESBS). Methods Using previously described methodology, topics spanning the breadth of ESBS were identified and assigned a literature review, evidence‐based review or evidence‐based review with recommendations format. Subsequently, each topic was written and then reviewed by skull‐base surgeons in both neurosurgery and otolaryngology. Following this iterative review process, the ICAR:ESBS document was synthesized and reviewed by all authors for consensus. Results The ICAR:ESBS document addresses the role of ESBS in primary cerebrospinal fluid (CSF) rhinorrhea, intradural tumors, benign skull‐base and orbital pathology, sinonasal malignancies, and clival lesions. Additionally, specific challenges in ESBS including endoscopic reconstruction and complication management were evaluated. Conclusion A critical review of the literature in ESBS demonstrates at least the equivalency of ESBS with alternative approaches in pathologies such as CSF rhinorrhea and pituitary adenoma as well as improved reconstructive techniques in reducing CSF leaks. Evidence‐based recommendations are limited in other pathologies and these significant knowledge gaps call upon the skull‐base community to embrace these opportunities and collaboratively address these shortcomings.