hadad flap-HADAD Bassagasteguy flap

This flap was designed by Gustavo Hadad & Luis Bassagasteguy (HB Flap)

Surgical Technique for harvesting the flap

The nasal cavity is decongested with oxymetazoline 0.05% and the nasal septum is infiltrated with lidocaine 2% with epinephrine 1/100,000 to 1/200,000. The inferior and middle turbinates are lateralized to allow visualization of the nasal septum from the cribriform plate to the nasal floor.

The flap is designed according to the size and shape of the anticipated defect, it is always best to overestimate the size and then trim the flap if needed. Two parallel incisions are performed following the sagittal plane of the septum, one over the maxillary crest and the other 1 to 2 cm below the most superior aspect of the septum (to preserves olfactory epithelium).

These incisions are joined anteriorly by a vertical incision. These incisions may be modified to account for the specific area of a reconstruction or to allow adequate oncologic margins. These incisions are usually taken with a cutter (electro-cautery)

At the posterior septum, the superior incision is extended laterally and with an inferior slant over the rostrum of the sphenoid sinus crossing it horizontally at the level of the natural ostium.

The inferior incision is extended superiorly along the free posterior edge of the nasal septum and then laterally to cross the posterior choana below the floor of the sphenoid sinus.

So now the flap is only attached posteriorly , pedicled by the posterior septal branch of the sphenopalatine artery.

Elevation starts anteriorly with a Cottle dissector or an elevator. The elevation of the flap from the anterior face of the sphenoid sinus is completed with care taken to preserve the posterolateral neurovascular pedicle.

The entire ipsilateral mucoperiosteum and mucoperichondrium may be harvested to cover anterior skull base defects as extensive as those that include the area from the posterior wall of the frontal sinus to the sella turcica and from orbit to orbit.

Now this flap is usually parked in the nasopharynx to provide space for working, The raw part of the cartilage is covered by the flap from the opposite side and incision site sutured, (reverse flap )

This rich vascular pedicle and branching is responsible for the fact that the HBF versatility, reliability, arc of rotation, and area of coverage is superior to any other flap previously described.

The HBF is the workhorse for the reconstruction of large defects of the skull base as it adds a high degree of reliability to the current methods of reconstruction. Its only caveat is that it needs to be anticipated in advance before a posterior septectomy is performed because this would destroy the vascular pedicle.

The HBF is a reliable reconstructive technique for extensive defects of the anterior, middle, clival, and parasellar skull base. Its use has resulted in a sharp decrease in the incidence of postoperative CSF leaks after EEA.

Multiple modification of this flap are present such as rescue and reverse flap , details of which shall be discussed in csf repair techniques .