TREPHINING OF THE FRONTAL SINUSES. 27 



By studying Plates IV-VII it will be seen that any collec- 

 tion of pus or other disease products at F would result in poor 

 drainage so far as may be obtained by trephining through 

 the external wall only, and consequently in order to com- 

 plete it aside from that through the superior maxillary sinus 

 an artificial communication between it and the nasal fossa 

 rnay be made at ST, Plate ■ VIII by a second opening oppo- 

 site that point near the median line midway between F and 

 N, Plate III, and then breaking through the thin walls of 

 the turbinated bone by means of a probe or other suitable 

 instrument and enlarging it suflBciently with the probe 

 pointed bistoury or with the finger. In locating the exact 

 point for making this opening in the turbinated bone it is 

 advisable to pass a slightly curved heavy probe, a pair of 

 long curved uterine dressing forceps or some other slightly 

 curved and somewhat rigid instrument up the nostril to 

 the operative region and having an index finger in the 

 sinus against the median wall, the movements of the sound 

 can easily be felt and the wall be broken down either by 

 pushing the sound up into the sinus or thrusting the finger 

 downwards into the nasal passage. 



In order to prevent aspiration of fluids, the animal must 

 be allowed to get up immediately or if under anaesthesia a 

 trachea tube should be inserted sufficiently early to avoid 

 danger. Thread a long probe with a heavy suture about 

 75 cm. long and inserting it through the trephine opening 

 into the nasal passage draw it out through the nostril and 

 removing the probe, attach a strip of gauze 75 cm. long to 

 one end of the suture, draw it out through the nostril and 

 tie the ends together on the side of the face to prevent dis- 

 Ipdgement. Retain the gauze in position for about forty- 

 eight hours to insure the permanency of the opening through 

 the turbinated bone. In case of severe hemorrhage the 

 cavity can be tamponed for twenty-four hours with a long 

 strip of gauze which may be secured if necessary by sutur- 



