Split-calvarial osteopericranial flap for reconstruction following endoscopic anterior resection of cranial base

The Transorbital Pericranial Flap

OBJECTIVE

The objective of the present study was to describe and evaluate the feasibility, mobility, and surface area provided by the simple and extended transorbital pericranial flap (TOPF). Furthermore, we compared this novel technique with the current practice of pericranial flap harvesting and insetting techniques. We also studied the adequacy of the TOPF in the reconstruction of postoperative anterior cranial fossa (ACF) defects.

METHODS

The TOPF was performed bilaterally in 5 alcohol-preserved, latex-injected human cadaveric specimens. The TOPF was harvested in 2 stages: the orbitonasal stage and the cranial stage. For the orbitonasal stage, a transorbital superior eyelid approach was used. We have described 2 harvesting techniques for creating 2 distinct TOPF types (simple and extended) according to the main vascular pedicle. The superficial flap areas offered by the simple and extended TOPF and the traditional bicoronal pericranial flap were calculated and compared. The distances from the supratrochlear and supraorbital arteries to specified anatomical landmarks were also measured. Additionally, the ACF defect area of relevant surgical cases performed using endoscopic transcribriform approaches were measured on immediate postoperative computed tomography head scans using radiological imaging software.

RESULTS

The harvest of both the simple and the extended TOPFs was efficient. As expected, the areas offered by simple and extended TOPFs were smaller than that offered by the traditional bicoronal flap. However, the surface area offered by either the simple or extended TOPF provides sufficient coverage for most ACF defects. A high spatial distribution was observed between the vascular pedicles and their respective foramen or notch.

CONCLUSIONS

The TOPF represents a novel harvesting, tunneling, and insetting technique that offers a large, versatile, pedicled flap for coverage of most standard ACF defects after endoscopic surgery.

[Tactics of reconstructive closure of basal defects after resection of midline tumors of the anterior skull base (a literature review)]

The purpose of this review is to analyze the techniques used to reconstruct midline defects in the anterior skull base after transcranial and endoscopic endonasal resection of skull base tumors. We provide brief information on the technique for preparing various flaps, indications and contraindications, and advantages and disadvantages. We analyze the international experience in the use of vascularized and non-vascularized flaps as well as the existing algorithms for reconstruction of complex defects of the midline structures of the skull base. The literature data demonstrate the absence of a conventional tactics of reconstructive closure of the discussed defects. To resolve this issue, a meta-analysis in combination with an original prospective study is required.

Updates in anterior skull base reconstruction

PURPOSE OF REVIEW

This article summarizes the indications and surgical techniques for the reconstructions of anterior skull base defects.

RECENT FINDINGS

There is increasing popularity of the vascularized pedicled flaps in endoscopic skull base surgery for the successful reconstruction of anterior skull base defects, compared with the use of free-tissue grafts. The location and size of the defect as well as the rate of cerebrospinal fluid (CSF) flow are important considerations for selection of the most appropriate reconstructive approach. Recent literature provides evidence suggesting that pedicled flaps may be more effective for clival defects and high-flow CSF leaks, potentially reducing the incidence of postoperative CSF leaks. Although the nasoseptal flap (NSF) continues to be the mainstay of endoscopic skull base reconstruction, alternative vascularized flaps exist when the NSF is impractical or unavailable, and new surgical approaches continue to evolve.

SUMMARY

Vascularized pedicled flaps, and especially the NSF, have greatly reduced complications associated with endoscopic skull base surgery. Multiple considerations should be taken into account during closure of skull base defects, and several options are available to accommodate different needs.