Abstract:Objective To investigate the association of surgical effect with resection (or partial excision) and retention of the involved lesions of horizontal portion of middle turbinate′s basal lamella(hBL) in functional endoscopic nasal sinus surgery (FESS). Methods By prospective trial design, 40 patients with hBL lesions of bilateral chronic rhinosinusitis with or without nasal polyps were enrolled from January 2014 to June 2017，and they were divided into single number group and double number group according to the time of hospital admission. In single number group, it was conducted that left hBL was excised or partially excised, and right hBL was retented in FESS, and the just reversed operation (excision or partial excision of right hBL and retention of left hBL) was performed in double number group. Scores of visual analogue scale(VAS), Lund-Kennedy endoscopic mucosal morphology and postoperative middle turbinate drift adhesion were evaluated before and 1-, 3-, 6-, 9- and 12- month after operation. Results There was no significant difference in VAS score between resection side and unresected side before and 1-, 3-, 6-, 9- and 12- month after operation. (P>0.05). The total score of Lund-Kennedy endoscopic mucosal morphology in the resection side was slightly lower than that in the reserved side (namely, the mucosal condition was better in the resection side ), but there was no statistical difference (P>0.05). The incidence of drift adhesion of middle turbinate on reserved side was slightly higher than that in resection side, but there was no significant difference (P>0.05). Conclusion If the fulcrum of the middle turbinate is stable, resection of hBL does not inevitably increase the probability of drift and adhesion of the middle turbinate. Good drainage, remove of irreversible lesions and bone malformation, complete contouring of diseased air cells and timely follow-up and cleanup before mucosal epithelialization play the key roles in the clinic efficacy of surgery.