Anatomic Considerations Guiding Single Versus Multiportal Endoscopic Approaches for Resection of Juvenile Nasopharyngeal Angiofibroma: Cases Series With Graded Multicorridor Resections

BACKGROUND

Juvenile nasopharyngeal angiofibromas (JNAs) are characterized by expansive and destructive growth, often invading the midline/paranasal sinuses, pterygopalatine fossa, and infratemporal fossa and can extend into the orbit, cavernous sinus, or intracranially.

OBJECTIVE

To evaluete the major benefits of the extended endoscopic endonasal approach (EEA) for JNA resection as compared with more traditional and invasive transpalatal and transfacial approaches. When JNAs extend into lateral anatomic compartments, the optimal operative trajectory often requires additional approach strategies or surgical staging.

METHODS

We retrospectively reviewed 8 cases of large JNAs arising in symptomatic adolescent boys (University of Pittsburgh Medical Center Stages II, III, and V) and discuss anatomic and tumor considerations guiding the decision of a pure EEA vs combined EEA and sublabial transmaxillary approach (Caldwell-Luc).

RESULTS

A pure extended EEA was used in 6 JNA cases (UPMC Stages II-III); a multiportal EEA + Caldwell-Luc maxillotomy was used in 2 cases. One of the 2 patients (UPMC Stage V) previously treated with multiportal EEA + Caldwell-Luc maxillotomy underwent staged left temporal/transzygomatic craniotomy, obtaining gross total resection. Seven patients ultimately underwent complete removal without recurrence. One patient with a small residual JNA (UPMC II) underwent stereotactic radiosurgery without progression to date.

CONCLUSION

JNAs with lateral extension into the infratemporal fossa often benefited from additional lateral exposure using a Caldwell-Luc maxillotomy. Cases with significant skull base and/or dural involvement may undergo staged surgical treatment; temporalis + transzygomatic craniotomy is often useful for second-stage approaches for residual tumor in these lateral infratemporal or intracranial regions. SRS should be considered for residual tumor if additional surgery is not warranted.

Thermal Conductance Through the Skull Base From Endoscopic Surgery Cauterization Instruments: Cadaver and Goat Model

OBJECTIVE

Cauterization prevents hemorrhage and optimizes the surgical field during endoscopic sinus surgery but may cause injury to nearby structures. The objective of this study is to examine thermal conductance from cauterization equipment across the skull base.

STUDY DESIGN

Cadaver and animal model.

SETTING

Surgical skills laboratory of an academic tertiary medical institution.

METHODS

A pilot study was conducted with a deidentified cadaver head and expanded to a goat head animal model. Endoscopic dissection was performed to expose the lamina papyracea, ethmoid roof, sphenoid roof, and frontal sinus. Cautery was applied to the frontal sinus of goat heads, and temperatures were measured via thermocouple sensors placed along the intracranial skull base. Surgical instruments studied included monopolar, bipolar, and endoscopic bipolar devices at various power settings.

RESULTS

Temperature increase, as averaged across all cautery powers and measurement positions, was highest for the monopolar cautery (17.55 °C) when compared with the bipolar and endoscopic bipolar devices (<2 °C for bipolar, Endo-Pen, Stammberger, and Wormald; P < .001). Monopolar cautery reached 30.86 °C at high power when averaged over all positions (P < .001) as compared with <3 °C for the other instruments. Temperatures rose as power of cautery was increased from low to medium and high. Temperatures decreased as the distance of the thermocouple sensor probe from the cautery origin increased.

CONCLUSION

Thermal conductance across the skull base varies depending on equipment and power of cautery, with monopolar resulting in the largest temperature increase. Choice and implementation of cauterization instruments have implications on inadvertent transmission of thermal energy during endoscopic sinus surgery.