Endoscopic Frontal Recess Approach (Draf I Procedure)

The endoscopic frontal recess approach (Draf type I) procedure is indicated when frontal sinus disease persists despite more conservative endoscopic approaches directed at the infundibulum and anterior ethmoid region. This procedure involves complete removal of the anterior ethmoid cells and uncinate process surrounding the frontal recess to the frontal ostium. Obstructing frontal cells, if present, are removed. The frontal sinus ostium may then drain into a patent frontal recess.

Schematic diagram of endoscopic frontal recess approach (Draf I) procedure. Anterior ethmoid air cells around the right frontal recess are removed. The recess is opened and to allow drainage of the frontal sinus ostium. The floor of the frontal sinus itself is not completely resected. (Adapted from Draf, ref. 1)
CT in a 34 year old female with history of recurrent right frontal sinusitis after endoscopic frontal recess approach (Draf I) procedure. Anterior ethmoid cells and uncinate process have been removed. Coronal image (Fig. A) and sagittal reformatted image (Fig. B) show patent frontal recess. The agger nasi cell has not been completely resected (arrow).
Coronal CT following bilateral endoscopic frontal recess approach (Draf I). The lateral border of the patent frontal recess is the lamina papyracea and the medial border is the middle turbinate.
Coronal CT in a patient following bilateral Draf I procedures. The patient had bilateral frontal sinus disease preoperatively. The right frontal recess is patent post-op despite an incompletely resected agger nasi cell (a). The left recess became occluded (likely as a result of middle turbinate lateralization) and disease within the left frontal sinus persisted.
Endoscopic image (30 degree endoscope) of a left Draf I (endoscopic frontal recess approach) procedure. The lateral boundary is the lamina papyracea (LP) and the medial boundary is the middle turbinate (MT). The frontal sinus can be easily seen through the patent frontal recess.


This 52 year old male suffered from chronic bilateral frontal sinusitis. Preoperative CT in Fig. A shows bilateral frontal mucosal thickening and a fluid level within an obstructing frontal cell (arrow). Within the left frontal sinus in Fig. B, an osteoma (O) was present. The frontal recesses were occluded by mucosal thickening bilaterally (Fig.C). CT and endoscopic images during computer-assisted procedure show tip of probe within the diseased frontal cell (Fig.D). Postoperatively (Fig. E), a surgical defect within the base of the frontal cell is seen (arrow) and the majority of the disease within and around that cell has resolved. Coronal image shows patency of the right frontal recess (Fig. F). The disease within the left frontal recess and sinus has cleared. An endoscopic image of the left frontal sinus at the time of surgery shows patent frontal ostium and non-obstructing frontal osteoma (O) (Fig. G). Purulent material can be seen at the medial aspect of the frontal sinus (arrow).