Endoscopic modified Lothrop procedure

Draf III Extension in the Endoscopic Endonasal Transethmoidal, Transcribriform Approach Through the Back Wall of the Frontal Sinus: A Cadaveric Study

BACKGROUND

The Draf III (modified endoscopic Lothrop) procedure has been proposed to extend the endonasal transethmoidal, transfovea ethmoidalis, and transcribriform approach through the back wall of the frontal sinus. The exposure is time-consuming and increases the risk of cerebrospinal fluid leak, and the indications for use are not well described. There are few data quantifying the advantage it conveys over the approach without the Draf III procedure.

METHODS

An endoscopic, endonasal transfovea, transcribriform approach was performed in 5 fresh, injected cadaveric heads. Anatomic boundaries and measurements of the exposure were compared before and after addition of a Draf III procedure. Computed tomography scans were performed before and after dissection, and additional radiographic measurements were made to quantify the additional exposure provided by the Draf III procedure. Also, 2 clinical cases are presented in which a Draf III procedure was used.

RESULTS

The mean anterior to posterior boundary from the frontal sinus to the planum sphenoidale before the Draf III procedure was 3.0 cm and after the Draf III procedure was 3.8 cm with an average change of 0.8 cm. After the Draf III procedure, the mean anterior to posterior boundary from the posterior wall of frontal sinus to the planum sphenoidale increased from 3.0 cm to 4.3 cm. There was an average increase of 1.3 cm with an average increased area of view of 1.79 cm(2).

CONCLUSIONS

This study quantifies the increased field of view provided by the Draf III procedure during anterior skull base dissection. Recommendations for preoperative examination of radiographic evidence are provided to help identify which individuals would benefit from the additional exposure.

The Draf III septal flap technique: a preliminary report

AIM

The most prevalent complication of Draf III surgery is recurrence of frontal recess stenosis. The aim of this study is to introduce a method to prevent closure of the recess.

TYPE OF THE STUDY AND SETTING

This is a retrospective study that was conducted in Ear, Nose and Throat Referral Center, Amir'Alam Hospital, Tehran.

METHODS AND MATERIALS

We introduced a new technique for reconstructing frontal recess mucosa and prevention of restenosis following Draf III operation; we covered the posterior wall of the common recess with a vascular mucosal flap from nasal septum.

RESULTS

During a 6-month period we used septal flaps based on anterior ethmoidal artery on four patients who had undergone endoscopic Draf III operation. During a 3-month follow-up period, frontal recess stenosis did recur in any of the patients.

CONCLUSION

Applying a precise and astute surgical method along with reconstructing common recess mucosa will improve the outcomes of endoscopic frontal sinus drill-out. We strongly recommend application of septal mucosal flap based on the anterior ethmoidal artery during Draf III operation to decrease the incidence of scar and recurrence of common frontal recess stenosis.