Intercarotid artery distance in the pediatric population: Implications for endoscopic transsphenoidal approaches to the skull base

Craniopharyngioma surgery for rhinologists

PURPOSE OF REVIEW

Craniopharyngiomas are rare tumors that that present with loss of pituitary function in most cases. They present in a bimodal age distribution and the most common treatment paradigms include gross total resection or subtotal resection followed by radiation. Endoscopic transnasal access to intradural tumors has become increasingly common due to improvements in equipment, increased familiarity with the surgical corridor and anatomy, and reconstruction techniques. As such, rhinologists play an increasingly important role in the management of craniopharyngiomas.

RECENT FINDINGS

Recent years have highlighted our growing experience with pediatric endonasal skull base surgery. Prior concerns including sphenoid pneumatization, midfacial growth restrictions, and intercarotid space limitations have been studied more extensively. It has been found that there are no increased complications with lack of sphenoid pneumatization, no changes to midfacial growth with endonasal techniques, and the inter-carotid distance is stable after around age 5. Advances in surgical and skull base reconstruction techniques and intraoperative monitoring have reduced the risks of complications from surgery.

SUMMARY

Rhinologists play an important role in craniopharyngioma surgery. The approach to and reconstruction after tumor removal are vital portions of the procedure that allow for resection and prevent postsurgical complications.

Endoscopic Endonasal Skull Base Surgery Complication Avoidance: A Contemporary Review

The endoscopic endonasal approach (EEA) provides a direct trajectory to ventral skull base lesions, avoidance of brain retraction, and clear visualization of cranial nerves as they exit skull base foramina. Despite these benefits, the EEA is not without complications. Here, we review published literature highlighting complications associated with the EEA including cerebrospinal fluid (CSF) leak, cranial nerve (CN) dysfunction, pituitary gland dysfunction, internal carotid artery (ICA) injury, infection, and others; we place special emphasis on discussing the prevention of these complications. As widespread adoption of the EEA continues, it becomes critical to educate surgeons regarding potential complications and their prevention while identifying gaps in the current literature to guide future research and advances in clinical care.

Anatomic Parameters and Growth of the Pediatric Skull Base: Endonasal Access Implications

Objectives: Endoscopic endonasal anterior skull base surgery has expanding use in the pediatric population, but the anatomy of pediatric patients can lead to limitations. This study aims to characterize the important anatomical implications of the pediatric skull base using computed tomography (CT) scans. Design: Retrospective analysis Setting: Tertiary academic medical center Participants: 506 patients aged 0-18 who had undergone maxillofacial and or head CTs between 2009-2016. Methods: Measurements included piriform aperture width, nare to sella distance (NSD), sphenoid pneumatization, olfactory fossa depth, lateral lamella cribriform plate angles, and intercarotid distances (ICD) at the superior clivus and cavernous sinus. These patients were then subdivided into 3 age groups adjusting for sex. ANCOVA models were fit comparing between all age groups and by sex. Results: Piriform aperture width, NSD, sphenoid sinus pneumatization as measured using lateral aeration and anterior sellar wall thickness, olfactory fossa depth, and ICD at the cavernous sinus was significantly different among all age groups (P<0.0001). Our results show that mean piriform aperture width increased with each age group. The mean olfactory fossa depth also had consistent age dependent growth. In addition, ICD at the cavernous sinus showed age dependent changes. When comparing by sexes, females consistently showed smaller measurements. Conclusion: The process of skull base development is age and sex dependent. During preoperative evaluation of pediatric patients for skull base surgery piriform aperture width, sphenoid pneumatization in both the anterior posterior and lateral directions, and ICD at the cavernous sinus should be carefully reviewed.