2025 Proffered Presentations
S052: A NOVEL "INSIDE OUT" MODIFIED ENDOSCOPIC PERI CRANIAL FLAP TECHNIQUE FOR SKULL BASE RECONSTRUCTION - A CADAVERIC MORPHOMETRIC STUDY.
Glen D Souza, MD; Peter Filip; Peter Papagiannopoulos; Pete Batra; Stephan Munich; Bobby Tajudeen; RUSH University Medical Center
Introduction: Reconstruction of dural defects following extensive anterior skull base surgery can be challenging, especially in cases where the nasoseptal flaps are not available or are infiltrated with tumor. In this study, we describe a novel inside-out technique to augment the previously described endoscopic peri cranial flap and, for the first time, provide morphometric measurements for harvesting the flap without an external incision on the root of the nose. The data from this study could help with pre-emptive reconstruction planning while avoiding possible disfiguring incisions on the face.
Methods: This is an ongoing cadaveric study being conducted at the skull base lab at Rush University Medical Center. The technical aspects of the procedure are described here. In brief, cadaveric endoscopic dissection was performed to mimic a trans-cribriform, para- sellar as well as a trans-clival approach to the anterior skull base, and the reconstructive cover provided by the endoscopic peri-cranial flap for each of these approaches was evaluated. After the endoscopic peri-cranial flap was raised till the nasion, trans-nasally under endoscopic visualization, the nasion was drilled from “inside” the nasal cavity with the endoscope light providing an estimate of the “out” point of exit to form a tunnel. The elevated peri-cranial flap was then guided into the “inside out” tunnel, thus creating and spreading over the defect (images 1 to 4).
Results: This ongoing study describes a novel way of introducing the peri-cranial flap into the surgical site without incisions on the nasion. An appropriate sample size of cadaver dissections is planned, with 4 in process. Morphometric measurements to help localize the supra orbital and supra trochlear arteries as well as extent of reconstructive coverage the flaps can reliably provide based on the extent of surgery is being studied.
Discussion: The inside-out technique provides a viable reconstruction alternative. By avoiding incisions of the face, it maintains the facial aesthetics. The anthropometric data collected from the study could help with precise graft harvesting and placement and provide measurements required to modify the flap size based on the extent of reconstructive needs.
Figure 1: Elevation of corridor to elevate the Endoscopic peri-cranial flap
Figure 2: The inside part (red arrow) “inside out” tunnel to deliver the flap
Figure 3: The outside part (red arrow)
“inside out” tunnel.
Figure 4: Extent of coverage provided by the flap
