Anatomical Variants of Post-ganglionic Fibers within the Pterygopalatine Fossa: Implications for Endonasal Skull Base Surgery

xlomafota13 shared this article with you from Inoreader Anatomical Variants of Post-ganglionic Fibers within the Pterygopalatine Fossa: Implications for Endonasal Skull Base Surgery Via Journal of Neurological Surgery Part B: Skull Base J Neurol Surg B Skull Base DOI: 10.1055/s-0040-1722714 Objectives The vidian nerve provides parasympathetic innervation to the nasal cavity and the lacrimal gland. Previous anatomic studies have primarily focused on preservation or severance of the vidian nerve proximal to the pterygopalatine ganglion (PPG). This study aimed to assess its neural fibers within the pterygopalatine fossa after synapsing at the PPG, and to explore potential clinical implications for endoscopic endonasal skull base surgery. Methods An endonasal transpterygoid approach was performed on eight cadaveric specimens (16 sides). The PPG and maxillary nerve within the pterygopalatine fossa were divided. The vidian nerve was traced retrograde into the foramen lacerum, and postganglionic fibers distal to the PPG were dissected following the zygomatic nerve into the orbit. Potential communicating branches between the ophthalmic nerve (V1) and the PPG were also explored. Results All sides showed a plexus of neural communications between the PPG and the maxillary nerve. The zygomatic nerve exits the maxillary nerve close to the foramen rotundum, piercing the orbitalis muscle to enter the orbit in all sides. The zygomatic nerve was identified running beneath the inferior rectus muscle toward a lateral direction. In 7/16 sides (43.75%), a connecting branch between V1 and the pterygopalatine ganglion was observed. Conclusion Neural communications between the PPG and the maxillary nerve were present in all specimens. A neural branch from V1 to the PPG potentially contributes additional postganglionic parasympathetic function to the lacrimal gland. [...] Georg Thieme Verlag KG Rüdigerstraße 14, 70469 Stuttgart, Germany Article in Thieme eJournals: Table of contents  |  Abstract  |  Full text View on the web Inoreader. Take back control of your news feed. Follow us on Twitter and Facebook.

Estimating Risk of Pituitary Apoplexy after Resection of Giant Pituitary Adenomas

xlomafota13 shared this article with you from Inoreader Estimating Risk of Pituitary Apoplexy after Resection of Giant Pituitary Adenomas Via Journal of Neurological Surgery Part B: Skull Base J Neurol Surg B Skull Base DOI: 10.1055/s-0041-1722993 Background Pituitary apoplexy after resection of giant pituitary adenomas is a rare but often cited morbidity associated with devastating outcomes. It presents as hemorrhage and/or infarction of residual tumor in the postoperative period. Because of its rarity, its incidence and consequences remain ill defined. Objective The aim of this study is to estimate the rate of postoperative pituitary apoplexy after resection of giant pituitary adenomas and assess the morbidity and mortality associated with apoplexy. Methods A systematic review of literature was performed to examine extent of resection in giant pituitary adenomas based on surgical approach, rate of postoperative apoplexy, morbidities, and mortality. Advantages and disadvantages of each approach were compared. Results Seventeen studies were included in quantitative analysis describing 1,031 cases of resection of giant pituitary adenomas. The overall rate of subtotal resection (<90%) for all surgical approaches combined was 35.6% (95% confidence interval: 28.0–43.1). Postoperative pituitary apoplexy developed in 5.65% (n = 19) of subtotal resections, often within 24 hours and with a mortality of 42.1% (n = 8). Resulting morbidities included visual deficits, altered consciousness, cranial nerve palsies, and convulsions. Conclusion Postoperative pituitary apoplexy is uncommon but is associated with high rates of morbidity and mortality in subtotal resection cases. These findings highlight the importance in achieving a maximal resection in a time sensitive fashion to mitigate the severe consequences of postoperative apoplexy. [...] Georg Thieme Verlag KG Rüdigerstraße 14, 70469 Stuttgart, Germany Article in Thieme eJournals: Table of contents  |  Abstract  |  < a href="https://www.thieme-connect.com/products/ejournals/html/10.1055/s-0041-1722993" target="_blank" rel="noopener" class="underlink bluelink" tabindex="-1">Full text View on the web Inoreader. Take back control of your news feed. Follow us on Twitter and Facebook.

Keyhole Endoscopic-Assisted Transcervical Approach to the Upper and Middle Retrostyloid Parapharyngeal Space: An Anatomic Feasibility Study

xlomafota13 shared this article with you from Inoreader Keyhole Endoscopic-Assisted Transcervical Approach to the Upper and Middle Retrostyloid Parapharyngeal Space: An Anatomic Feasibility Study Via Journal of Neurological Surgery Part B: Skull Base J Neurol Surg B Skull Base DOI: 10.1055/s-0041-1722931 Objectives The aim of this study was to describe the anatomical nuances, feasibility, limitations, and surgical exposure of the parapharyngeal space (PPS) through a novel minimally invasive keyhole endoscopic-assisted transcervical approach (MIKET). Design Descriptive cadaveric study. Setting Microscopic and endoscopic high-quality images were taken comparing the MIKET approach with a conventional combined transmastoid infralabyrinthine transcervical approach. Participants Five colored latex-injected specimens (10 sides). Main Outcome Measures Qualitative anatomical descriptions in four surgical stages; quantitative and semiquantitative evaluation of relevant landmarks. Results A 5 cm long inverted hockey stick incision was designed to access a corridor posterior to the parotid gland after independent mobilization of nuchal and cervical muscles to expose the retrostyloid PPS. The digastric branch of the facial nerve, which runs 16.5 mm over the anteromedial part of the posterior belly of the digastric muscle before piercing the parotid fascia, was used as a landmark to identify the main trunk of the facial nerve. MIKET corridor was superior to the crossing of the accessory nerve over the internal jugular vein within 17.3 mm from the jugular process. Further exposure of the occipital condyle, vertebral artery, and the jugular bulb was achieved. Conclusion The novel MIKET approach provides in the cadaver straightforward access to the upper and middle retrostyloid PPS through a natural corridor without injuring important neurovascular structures. Our work sets the anatomical nuances and limitations that should guide future clinical studies to prove its efficacy and safety either as a stand-alone procedure or as an adjunct to other approaches, such as the endonasal endoscopic approach. [...] Georg Thieme Verlag KG Rüdigerstraße 14, 70469 Stuttgart, Germany Article in Thieme eJournals: Table of contents  |  Abstract  |  Full text View on the web Inoreader. Take back control of your news feed. Follow us on Twitter and Facebook.

Systematic Review Comparing Open versus Endoscopic Surgery in Clival Chordomas and a 10-Year Single-Center Experience

xlomafota13 shared this article with you from Inoreader Systematic Review Comparing Open versus Endoscopic Surgery in Clival Chordomas and a 10-Year Single-Center Experience Via Journal of Neurological Surgery Part B: Skull Base J Neurol Surg B Skull Base DOI: 10.1055/s-0041-1722933 Objectives Chordomas are rare, slow-growing, and osteo-destructive tumors of the primitive notochord. There is still contention in the literature as to the optimal management of chordoma. We conducted a systematic review of the surgical management of chordoma along with our 10-year institutional experience. Design A systematic search of the literature was performed in October 2020 by using MEDLINE and EMBASE for articles relating to the surgical management of clival chordomas. We also searched for all adult patients surgically treated for primary clival chordomas at our institute between 2009 and 2019. Participants Only articles describing chordomas arising from the clivus were included in the analysis. For our institution experience, only adult primary clival chordoma cases were included. Main Outcome Measures Patients were divided into endoscopic or open surgery. Rate of gross total resection (GTR), recurrence, and complications were measured. Results Our literature search yielded 24 articles to include in the study. Mean GTR rate among endoscopic cases was 51.9% versus 41.7% for open surgery. Among the eight cases in our institutional experience, we found similar GTR rates between endoscopic and open surgery. Conclusion Although there is clear evidence in the literature that endoscopic approaches provide better rates of GTR with fewer overall complications compared to open surgery. However, there are still situations where endoscopy is not viable, and thus, open surgery should still be considered if required. [...] Georg Thieme Verlag KG Rüdigerstraße 14, 70469 Stuttgart, Germany Article in Thieme eJournals: Table of contents  |  Abstract  |  Full text View on the web Inoreader. Take back control of your news feed. Follow us on Twitter and Facebook.

3D Printing for Complex Cranial Surgery Education: Technical Overview and Preliminary Validation Study

xlomafota13 shared this article with you from Inoreader 3D Printing for Complex Cranial Surgery Education: Technical Overview and Preliminary Validation Study Via Journal of Neurological Surgery Part B: Skull Base J Neurol Surg B Skull Base DOI: 10.1055/s-0040-1722719 Background: 3D printing—also known as additive manufacturing—has a wide range of applications. Reproduction of low-cost, high-fidelity, disease- or patient-specific models presents a key developmental area in simulation and education research for complex cranial surgery. Methods: Using cadaveric dissections as source materials, skull base models were created, printed, and tested for educational value in teaching complex cranial approaches. In this pilot study, assessments were made on the value of 3D printed models demonstrating the retrosigmoid and posterior petrosectomy approaches. Models were assessed and tested in a small cohort of neurosurgery resident subjects (n = 3) using a series of 10 radiographic and 2 printed case examples, with efficacy determined via agreement survey and approach selection accuracy. Results: All subjects indicated agreement or strong agreement for all study endpoints that 3D printed models provided significant improvements in understanding of neuroanatomic relationships and principles of approach selection, as compared to 2D dissections or patient cross-sectional imaging alone. Models were not superior to in-person hands-on teaching. Mean approach selection accuracy was 90% ( ±  13%) for 10 imaging-based cases, or 92% ( ±  7%) overall. Trainees strongly agreed that approach decision-making was enhanced by adjunctive use of 3D models for both radiographic and printed cases. Conclusion: 3D printed models incorporating skull base approaches and/or pathologies provide a compelling addition to the complex cranial education armamentarium. Based on our preliminary analysis, 3D printed models offer substantial potential for pedagogical value as dissection guides, adjuncts to preoperative study and case preparation, or tools for approach selection training and evaluation. [...] Georg Thieme Verlag KG Rüdigerstraße 14, 70469 Stuttgart, Germany Article in Thieme eJournals: Table of contents  |  Abstract  |  Full text View on the web Inoreader. Take back control of your news feed. Follow us on Twitter and Facebook.

Anatomic Considerations of Microvascular Free Tissue Transfer in Endoscopic Endonasal Skull Base Surgery

xlomafota13 shared this article with you from Inoreader Anatomic Considerations of Microvascular Free Tissue Transfer in Endoscopic Endonasal Skull Base Surgery Via Journal of Neurological Surgery Part B: Skull Base J Neurol Surg B Skull Base DOI: 10.1055/s-0041-1722935 Objective Though microvascular free tissue transfer is well established for open skull base reconstruction, normative data regarding flap design and inset after endoscopic endonasal skull base surgery (ESBS) is lacking. We aim to describe anatomical considerations of endoscopic endonasal inset of free tissue transfer of transclival (TC) and anterior cranial base resection (ACBR) defects. Design and Setting Radial forearm free tissue transfer (RFFTT) model. Participants Six cadaveric specimens. Main Outcome Measures Pedicle orientation, pedicle length, and recipient vessel intraluminal diameter. Results TC and ACBR defects averaged 17.2 and 11.7 cm2, respectively. Anterior and lateral maxillotomies and endoscopic medial maxillectomies were prepared as corridors for flap and pedicle passage. Premasseteric space tunnels were created for pedicle tunneling to recipient facial vessels. For TC defects, the RFFTT pedicle was oriented cranially with the flap placed against the clival defect (mean pedicle length 13.1 ± 0.6 cm). For ACBR defects, the RFFTT pedicle was examined in three orientations with respect to anterior–posterior axis of the RFFTT: anteriorly, posteriorly, and laterally. Lateral orientation offered the shortest average pedicle length required for anastomosis in the neck (11.6 ± 1.29 cm), followed by posterior (13.4 ± 0.7cm) and anterior orientations (14.4 ± 1.1cm) (p < 0.00001, analysis of variance). Conclusions In ACBR reconstruction using RFFTT, our data suggests lateral pedicle orientation shortens the length required to safely anastomose facial vessels and protects the frontal sinus outflow anteriorly while limiting pedicle exposure through a maxillary corridor within the nasal cavity. With greater understanding of anatomical factors related to successful preoperative flap planning, free tissue transfer may be added to the ESBS reconstruction ladder. Level of Evidence NA [...] Georg Thieme Verlag KG Rüdigerstraße 14, 70469 Stuttgart, Germany Article in Thieme eJournals: Table of contents  |  Abstract  |  Full text View on the web Inoreader. Take back control of your news feed. Follow us on Twitter and Facebook.

Epigenetic and metabolic regulation of epidermal homeostasis

xlomafota13 shared this article with you from Inoreader Epigenetic and metabolic regulation of epidermal homeostasis Via Experimental Dermatology Abstract Continuous exposure of the skin to environmental, mechanical, and chemical stress necessitates constant self‐renewal of the epidermis to maintain its barrier function. This self‐renewal ability is attributed to epidermal stem cells (EPSCs), which are long‐lived, multipotent cells located in the basal layer of the epidermis. Epidermal homeostasis – coordinated proliferation and differentiation of EPSCs – relies on fine‐tuned adaptations in gene expression which in turn are tightly associated with specific epigenetic signatures and metabolic requirements. In this review, we will briefly summarize basic concepts of EPSC biology and epigenetic regulation with relevance to epidermal homeostasis. We will highlight the intricate interplay between mitochondrial energy metabolism and epigenetic events – including miRNA‐mediated mechanisms – and discuss how the loss of epigenetic regulation and epidermal homeostasis manifests in skin disease. Discussion of inherited epider molysis bullosa (EB) and disorders of cornification will focus on evidence for epigenetic deregulation and failure in epidermal homeostasis, including stem cell exhaustion and signs of premature aging. We reason that the epigenetic and metabolic component of epidermal homeostasis is significant and warrants close attention. Charting epigenetic and metabolic complexities also represents an important step in the development of future systemic interventions aimed at restoring epidermal homeostasis and ameliorating disease burden in severe skin conditions. View on the web Inoreader. Take back control of your news feed. Follow us on Twitter and Facebook.