Repair of Anterior Skull Base Defect by Dual-Layer/Split-Frontal Pericranial Flap

Reducing CSF complications by a recycled Hadad's flap combined with autologous mucosa in secondary endoscope transsphenoidal surgery

Background

Transsphenoidal secondary operations are a minority but not a rare occurrence. How to viably prevent cerebral fluid (CSF)-related complications and confine surgery-caused injury in secondary surgery as minimally as possible is a huge challenge. This article shares our solution of recycling a prior Hadad-Bassagasteguy flap (HBF) along with a using small piece of free autologous mucosa to reconstruct the skull base.

Methods

Of 69 patients, fitted criteria were assigned into 2 different groups: a recycled HBF incorporated with an autologous free mucosa and a recycled HBF incorporated with an artificial dura to rebuild the skull base in secondary transsphenoidal surgery. The postoperative morbidities of pseudomeningocele, CSF leakage and meningitis were recorded and analyzed.

Results

A recycled HBF incorporated with an autologous mucosa is capable of reducing CSF complications compared to that of the matched group, particularly decreasing the morbidity of meningitis in secondary transsphenoidal surgery. Diabetes mellitus, craniopharyngioma, chordoma and the utilization of artificial dura were independent risk factors for CSF complications in secondary transsphenoidal surgery through univariate and multivariate logistic regression. In addition, diabetes mellitus and artificial dura are more likely to induce CSF leakage and meningitis. Patients suffering from craniopharyngioma are more susceptible to meningitis. Chordoma indiscriminately increased the risk of each CSF complication.

Conclusion

A recycled HBF incorporated with an autologous mucosa is reliable for reconstructing the skull base in secondary transsphenoidal surgery, especially for patients simultaneously suffering from diabetes mellitus and central skull base tumors.

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.