The Role of Canine Fossa Trephination in the Severely Diseased Maxillary Sinus (CFT)

The hypothesis of this study is that canine fossa trephination (CFT) improves surgical outcomes for patients with a severely diseased maxillary sinus.

Chronic sinusitis (CRS) with nasal polyps and thick mucin in the sinuses adversely affects results from endoscopic sinus surgery (ESS) because failure to clear the disease leads to ongoing inflammation and symptoms. In particular a subset of CRS patients with thick eosinophilic mucin (EMCRS) develop recurrent symptoms and require further surgeries. ESS techniques for the maxillary sinus requires a WMA in the side wall of the sinus and the use of curved debrider instruments to clear the polyps. Sometimes this doesn't provide access to the inferior/floor and anterior/front aspects of the maxillary sinus due to the fact that the maxillary sinus is on the side of the nasal cavity at an angle. The CFT through the front wall of the sinus was developed years ago as an alternative approach to improve access to these areas. Both techniques are acceptable standard treatments and which one is initially used to address the maxillary sinus currently depends on surgeon preference. The role of CFT has been studied by Sathanatar et al (Laryngoscope 2005) and Lee et al (Laryngoscope 2008) which provided conflicting results. Differences in their study patients and methodology could explain the different outcomes. Hence this study is proposed to clarify the role of CFT in patients with extensive maxillary sinus disease to see whether initial use of CFT is more helpful than WMA in the severely diseased maxillary sinus with polyps and mucin. Findings from this study may improve surgical outcomes for CRS patients in the future.

Patients undergoing standard ESS and a canine fossa trephine technique, which is a 6 mm puncture in the anterior wall of the maxillary sinus, to allow standard sinus debrider blades and instruments to pass into the sinus to clear polyps in the maxillary sinus.

Patients undergoing standard ESS without canine fossa trephination with clearance of the maxillary sinus polyps via a wide maxillary antrostomy (WMA) with use of curved debrider surgical blades and instruments.

Grade 0: Normal mucosa with no evidence of disease Grade 1: Edematous mucosa and/or eosinophilic mucus Grade 2: Polypoidal mucosa and/or eosinophilic mucus Grade 3: Polyps and fungal debris

Inclusion Criteria: Patients with extensively opacified maxillary sinuses on CT scanning undergoing Endoscopic Sinus Surgery for Chronic Rhinosinusitis Patients with Eosinophilic Mucin Chronic Rhinosinusitis or fungal sinusitis disease undergoing Endoscopic Sinus Surgery for Chronic Rhinosinusitis Patients with Recalcitrant Chronic Rhinosinusitis undergoing Endoscopic Sinus Surgery for Chronic Rhinosinusitis Patients over the age of 18 Patients able to give informed consent to participate in the study Exclusion Criteria: Patients will be excluded if they are unable to undergo surgery due to co morbidities. Patients with previous Caldwell-Luc procedures Patients with pre existing paraesthesia of the upper teeth or gums Patients with destructive lesions of the maxilla Patients with systemic disease affecting the paranasal sinuses (e.g. Wegener's granulomatosis) Patients immune compromised

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Lee JY, Lee SH, Hong HS, Lee JD, Cho SH. Is the canine fossa puncture approach really necessary for the severely diseased maxillary sinus during endoscopic sinus surgery? Laryngoscope. 2008 Jun;118(6):1082-7. doi: 10.1097/MLG.0b013e318169028d.

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