Rotational Latissimus Dorsi Flap for Lateral Repair of Thoracic Cerebrospinal Fluid-Pleural Fistula: Case Report.

BACKGROUND AND IMPORTANCE: Giant calcified thoracic discs are challenging surgical pathologies that tend to be more centrally located and calcified. This complicates the removal process and potentiates the formation of dural defects, resulting in persistent cerebrospinal fluid (CSF) leaks and the formation of pleural fistulas. The typical intervention for this is CSF diversion through external ventricular drain or lumbar drain placement, followed by direct repair. However, if all these measures fail, subsequent salvage techniques have not been described previously. CLINICAL PRESENTATION: A 45-year-old man with past medical history of obesity (body mass index: 58), hypertension, and type 2 diabetes mellitus presented to the emergency department with thoracic myelopathy symptoms. MR demonstrated a giant calcified thoracic discs at T7-T8 with severe spinal cord compression. Intraoperatively, the disc was found fused to the dura and removal caused a large ventrolateral dural dehiscence. CSF diversion and direct repair were attempted unsuccessfully, so a salvage procedure with a rotational pedicled latissimus dorsi flap was performed. The patient's latissimus dorsi was exposed and resected from attachments, maintaining thoracodorsal blood supply, while removing thoracodorsal innervation. The flap was then rotated into the previous corpectomy site. The dural defect was repaired with a sealant patch, overlayed with a parietal pleural flap and the latissimus dorsi flap. By the patient's last follow-up, he had full functional independence at home. CONCLUSION: We present a surgical case highlighting the challenges of managing postoperative CSF-pleural fistula occurring after giant calcified thoracic disc removal and the successful use of a novel rotational latissimus dorsi flap to definitively repair the fistula after unsuccessful primary interventions.

Tunable Hydrogen-Related Defects in ZnO Nanowires Using Oxygen Plasma Treatment by Ion Energy Adjustment.

The chemical bath deposition (CBD) process enables the deposition of ZnO nanowires (NWs) on various substrates with customizable morphology. However, the hydrogen-rich CBD environment introduces numerous hydrogen-related defects, unintentionally doping the ZnO NWs and increasing their electrical conductivity. The oxygen-based plasma treatment can modify the nature and amount of these defects, potentially tailoring the ZnO NW properties for specific applications. This study examines the impact of the average ion energy on the formation of oxygen vacancies (VO) and hydrogen-related defects in ZnO NWs exposed to low-pressure oxygen plasma. Using X-ray photoelectron spectroscopy (XPS), 5 K cathodoluminescence (5K CL), and Raman spectroscopy, a comprehensive understanding of the effect of the oxygen ion energy on the formation of defects and defect complexes was established. A series of associative and dissociative reactions indicated that controlling plasma process parameters, particularly ion energy, is crucial. The XPS data suggested that increasing the ion energy could enhance Fermi level pinning by increasing the amount of VO and favoring the hydroxyl group adsorption, expanding the depletion region of charge carriers. The 5K CL and Raman spectroscopy further demonstrated the potential to adjust the ZnO NW physical properties by varying the oxygen ion energy, affecting various donor- and acceptor-type defect complexes. This study highlights the ability to tune the ZnO NW properties at low temperature by modifying plasma process parameters, offering new possibilities for a wide variety of nanoscale engineering devices fabricated on flexible and/or transparent substrates.

Management of recurrent giant hemangiopericytoma: illustrative cases.

BACKGROUND: Hemangiopericytoma (HPC) is a rare malignancy accounting for 0.4% of intracranial tumors. HPCs are characterized by local aggressiveness, high rates of recurrence, and a tendency to metastasize to extracranial sites. These features make management of HPCs challenging, often requiring a combination of radical resection and radiation. Given their rarity, optimal treatment algorithms remain undefined. OBSERVATIONS: The authors report a series of four patients who underwent resection of intracranial HPC. Mean age at presentation was 49.3 years. Three patients had reoperation for progression of residual tumor, and one patient was surgically retreated for recurrence. One patient received adjuvant radiotherapy following initial resection, and three patients received adjuvant radiotherapy following resection of recurrent or residual disease. There was one death in the series. Average progression-free survival and overall survival following the index procedure were 32.8 and 82 months, respectively. Progression occurred locally in all patients, with metastatic recurrence in one patient. LESSONS: The current gold-standard treatment for intracranial HPC consists of gross-total resection followed by radiation therapy. This approach allows satisfactory local control; however, given the tendency for these tumors to recur either locally or distally within or outside of the central nervous system, there is a need for salvage therapies to improve long-term outcomes for patients.

Microvascular Decompression for Trigeminal Neuralgia Caused by Vascular Compression on the Trigeminal Sensory Nucleus and Descending Trigeminal Tract.

BACKGROUND: Trigeminal neuralgia (TN) is characterized by paroxysmal episodes of severe shocklike orofacial pain typically resulting from arterial compression on the trigeminal root entry zone. However, neurovascular conflict in more proximal parts of the trigeminal pathway within the pons is extremely rare. METHODS: The authors present a case of microvascular decompression for TN caused by dual arterial compression on the dorsolateral pons, along with a brief literature review. RESULTS: Our patient was a 74-year-old man with episodic left-sided facial stabbing pain. Brain magnetic resonance imaging revealed a dual arterial compression on dorsolateral pons, the known site of the trigeminal sensory nucleus and descending trigeminal tract. Microvascular decompression was performed via a retrosigmoid approach. Complete pain relief and partial improvement of the facial hypesthesia were achieved immediately after surgery and the Barrow Neurological Institute (BNI) pain intensity score improved from V to I, and the BNI hypesthesia score decreased from III to II within a month following surgery. The literature review identified 1 case of TN secondary to an arteriovenous malformation in root entry zone with lateral pontine extension. One month following partial coagulation of the draining vein, the patient was reportedly able to reduce medication dosage by half to achieve an improvement of BNI pain intensity score from V to IIIa. CONCLUSIONS: Neurovascular compression in the trigeminal tract and nucleus is a rare but potential cause of TN. A thorough investigation of the trigeminal pathway should be considered during preoperative evaluation and intraoperative inspection, particularly if no clear offending vessel is identified.

Intradural Pituitary Hemitransposition: Technical Note and Case Series Illustration.

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.

Real-time ultrasound guidance in the endoscopic endonasal resection of a retro-odontoid pannus: Technical note and case illustration.

Background and Objectives: Odontoidectomy is a surgical procedure indicated in the setting of various pathologies, with the main goal of decompressing the ventral brain stem and spinal cord as a result of irreducible compression at the craniovertebral junction. The endoscopic endonasal approach has been increasingly used as an alternative to the transoral approach as it provides a straightforward, panoramic, and direct approach to the odontoid process. In addition, intraoperative ultrasound (US) guidance is a technique that can optimize safety and surgical outcomes in this context. It is used as an adjunct to neuronavigation and provides intraoperative confirmation of decompression of craniovertebral junction structures in real time. The authors aim to present the use and safe application of real-time intraoperative US guidance during endonasal endoscopic resection of a retro-odontoid pannus. Methods: A retrospective chart review of a single case was performed and presented herein as a case report and narrated operative video. Results: A minimally invasive US transducer was used intraoperatively to guide the resection of a retro-odontoid pannus and confirm spinal cord decompression in real time. Postoperative examination of the patient revealed immediate neurological improvement. Conclusions: Intraoperative ultrasonography is a well described and useful modality in neurosurgery. However, the use of intraoperative US guidance during endonasal endoscopic approaches to the craniovertebral junction has not been previously described. As demonstrated in this technical note, the authors show that this imaging modality can be added to the ever-evolving armamentarium of neurosurgeons to safely guide the decompression of neural structures within the craniocervical junction with good surgical outcomes.