Quantitative Prediction of the Location of Carotid Bifurcation and Neurovascular Structures in the Carotid Region: A Cross-Sectional Cadaveric Study.

INTRODUCTION: The carotid region is encountered in vascular and neurological surgery and carries a potential for vascular and cranial nerve trauma. The carotid bifurcation is an especially important landmark and difficult to predict based on currently established landmarks. This study is a detailed analysis of the carotid region and proposes a novel methodology to predict the height of the bifurcation. MATERIALS AND METHODS: Superficial and deep dissections were performed on the anterior triangle of the neck to expose the carotid region in twenty-one formalin-fixed donor cadavers. Musculoskeletal and neurovascular structures were assessed in relation to the carotid bifurcation and the medial border of the clavicle (MBC). RESULTS: The carotid bifurcation occurred, on average, 11.4 mm higher on the left (p < 0.001; 95% CI: 9.28, 13.54). The superior thyroid artery (p < 0.001), facial vein (p < 0.001), and cranial nerve XII (p < 0.001) were all more distal on the left side when measured from the MBC while the angle of the mandible and stylohyoid muscle remained symmetric. Left- and right-sided vascular structures were symmetric when measured from the carotid bifurcation. CONCLUSIONS: Neurovascular structures within the carotid region are likely to be anatomically superior on the left side while vessels are likely to remain symmetric in relation to the carotid bifurcation. When measured from the MBC, the bifurcation height can be predicted by multiplying the distance between the MBC and mastoid process by 0.65 (right side) or 0.74 (left side). This novel methodological estimation may be easily learned and directly implemented in clinical practice.

An Intravagal Parathyroid Adenoma in the Poststyloid Parapharyngeal Space.

OBJECTIVES: Describe a case of an intravagal parathyroid adenoma. CASE: A 35-year-old male presented with symptomatic primary hyperparathyroidism and non-localizing imaging studies. Intraoperative venous sampling revealed a substantial gradient within the right internal jugular vein. Repeat imaging identified an enhancing lesion in the right parapharyngeal space at the skull base. An intravagal parathyroid adenoma was discovered intraoperatively. Microdissection of the adenoma out of the nerve allowed preservation of laryngeal function and an appropriate drop in ioPTH. CONCLUSIONS: Intraneural parathyroid adenomas are exceedingly rare. The clinical, radiologic, and histologic findings of an intravagal parathyroid adenoma in the post-styloid parapharyngeal space are described. Laryngoscope, 131:453-456, 2021.

Transcervical endoscopic approach for parapharyngeal space: a cadaver study and clinical practice.

Background: The traditional transcervical approach is frequently applied but limited in handling the tumors in parapharyngeal space.Objectives: We explore a new transcervical endoscopic approach with more direct visualization, less complications, and better outcomes.Material and methods: Eight cadaver heads (sixteen sides) were prepared for endoscopic dissection. Clinical cases were carefully selected, and thirty patients accepted the transcervical endoscopic surgery.Results: The transcervical approach with an endoscopic video system clearly exposed the detailed structures in the parapharyngeal space. The stylopharyngeus, styloglossus muscles, and styloid process were critical landmarks in this approach. During the thirty cases of clinical surgeries, internal carotid arteries and cranial nerves could be effectively exposed and protected with the endoscopic video system. Accurate hemostasis could be achieved under endoscopic transcervical approach with a mean amount between 30 to 100 ml of hemorrhaging. There was no postoperative hemorrhages and emergency tracheotomies. The follow up led to promising results.Conclusions and significance: The transcervical endoscopic approach provides a wide corridor for surgery in the parapharyngeal space. With accurate hemostasis, this approach can be applied as the first-line strategy for parapharyngeal surgeries in selected patients.