BACKGROUND AND PURPOSE Recently, surgeons have used an expanded endonasal surgical approach (EENS) to access skull base lesions not previously accessible by minimally invasive techniques. Reconstruction of the large skull base defects created during EENS is necessary to prevent postoperative CSF leaks. A vascular pedicle nasoseptal mucoperiosteal flap based on the nasoseptal artery, (Hadad-Bass...

OBJECTIVES/HYPOTHESIS Endoscopic endonasal skull base surgery defects require effective reconstruction. Although the nasoseptal flap (NSF) has become our institution's workhorse for large skull base defects with cerebrospinal fluid (CSF) leaks, situations where it is unavailable require secondary flaps. Clinical outcomes, pearls and pitfalls, and an algorithm will be presented for these seconda...

During cellular DNA replication the lagging strand is generated as discontinuous segments called Okazaki fragments. Each contains an initiator RNA primer that is removed prior to joining of the strands. Primer removal in eukaryotes requires displacement of the primer into a flap that is cleaved off by flap endonuclease 1 (FEN1). FEN1 employs a unique tracking mechanism that requires the recogni...

Different reconstruction techniques of the anterior and middle skull base as consequence of a defect after surgical treatment of neoplastic pathologies are described in the literature. The aim of the present study is to present our experience regarding the use of microvascular free flaps for reconstruction of the anterior or middle skull base after large defects caused by removal of malignant n...

OBJECTIVE The aim was to investigate the relationship between the dimensions (length, width, and thickness) of random advancement skin flaps and retained tissue perfusion and oxygenation. METHODS Flaps were raised on the flanks of pigs. The flaps were either 0.5 or 1.0 cm wide, thin (dissected halfway through the subcutaneous tissue) or thick (dissected down to the muscle fascia). Tissue perf...

Dna2 is a nuclease/helicase with proposed roles in DNA replication, double-strand break repair and telomere maintenance. For each role Dna2 is proposed to process DNA substrates with a 50-flap. To date, however, Dna2 has not revealed a preference for binding or cleavage of flaps over single-stranded DNA. Using DNA binding competition assays we found that Dna2 has substrate structure specificity...

The dermal papilla comprises the specialised mesenchymal cells at the base of the hair follicle. Communication between dermal papilla cells and the overlying epithelium is essential for differentiation of the hair follicle lineages. We report that Sox2 is expressed in all dermal papillae at E16.5, but from E18.5 onwards expression is confined to a subset of dermal papillae. In postnatal skin, S...

OBJECTIVE Reconstruction of the cranial base using vascularized tissue promotes rapid and complete healing, thus avoiding complications caused by persistent communication between the cranial cavity and the sinonasal tract. The Hadad-Bassagasteguy flap (HBF), a neurovascular pedicled flap of the nasal septum mucoperiosteum and mucoperichondrium based on the nasoseptal artery, seems to be advanta...