EFFECT OF POSTERIOR NASAL NEURECTOMY ON THE SIZE OF INFERIOR TURBINATES IN PATIENTS WITH ALLERGIC RHINITIS- AN OBSERVATIONAL STUDY

Abstract

INTRODUCTION: Allergic rhinitis is a type of hypersensitivity reaction of sinonasal mucus membrane. As inferior turbinate is the first point of contact to allergen on inhalation, it is affected the worst in terms of inflammation of mucus membrane leading to hypertrophy of inferior turbinate in case of perennial allergen exposure or long-standing inflammation. This results in nasal obstruction mechanically to some extent due to relative increase in size of inferior turbinates on both sides and functional obstruction due to congestion of nasal mucosa covering the bilateral inferior turbinates with additional symptoms of increased bouts of sneezing and clear watery nasal discharge while attempting to expatriate the trigger. Initially management option of environmental control measures works to some extent but not in all cases for whom pharmacotherapy is initiated. Antihistamines, Decongestants, intranasal and oral corticosteroids are used. Immunotherapy can be tried but not all are successful as tracing the precise allergen is not always possible or multiple allergens are associated with single patient. Due to such technical difficulties, surgical options are offered to alleviate symptoms which include Septoplasty, inferior turbinate reduction, FESS and at times Vidian neurectomy. Posterior nasal nerve resection is relatively newer and safer surgical option that is equally effective as others. This is the area explored in present study. AIM OF THE STUDY: The primary aim of the study was to investigate the impact of Posterior nasal neurectomy on size of inferior turbinate with additional objective to look for effective symptom control in refractory allergic rhinitis cases after resection of Posterior nasal nerve endoscopically. xv MATERIALS AND METHODS: 36 patients with symptoms of Allergic rhinitis not responding to medical therapy for a minimum of 4 weeks were selected. Diagnostic nasal endoscopy and CT of nose and PNS was done. TNSS assessment and measure of size and volume of bilateral inferior turbinates using CT was done preoperatively. Clinical findings and size of inferior turbinate was recorded. Bilateral posterior nasal neurectomy was done in all 36 patients in addition to FESS and/or Septoplasty for those who required as they were diagnosed with DNS and /or chronic rhinosinusitis with or without polyposis during DNE and CT nose and PNS. Post surgery, size and volume of bilateral inferior turbinates was measured at 3 months and 6 months. TNSS assessment repeated at 3 months and 6 months postoperatively. Data was documented and analysed. STATISTICAL ANALYSIS: ANOVA test (Analysis of variance Statistical test) was used to verify significance in change in volume reduction of right and left inferior turbinates and TNSS assessment post-surgery at 3 months and 6 months with respect to DNS, CRS and Bilateral sinonasal polyposis. One way ANOVA and repeated measures ANOVA was used appropriately. Independent Sample t-test was used to analyse the change in reduction of right inferior turbinate volume, change in reduction of left inferior turbinate volume, Change in TNSS scores distribution pre-op to 3rd month post op with respect to time and test statistics in chronic rhinosinusitis and with bilateral sinonasal polyposis. Chi square test was used to analyse if there is significant difference in percentage of reduction in nasal symptoms between pre-op and 3rd month postop among patients with regards to presence or absence of DNS, presence or absence of CRS and presence or absence of sinonasal polyposis. RESULTS: (1) Amongst the variables tested using repeated measures ANOVA, significance was found in (i) Change in the volume of inferior turbinate with (a) F=210.321; p= .001 indicating that there is a significant reduction in the volume of the right inferior turbinate xvi from preoperative mean of 6.51 to postoperative 6 months mean of 1.90. (b) F=235.737; p= .001 indicating that there is a significant reduction in the volume of the left inferior turbinate from preoperative mean of 6.45 to postoperative 6 months mean of 2.15. (ii) Change in volume of right and left inferior turbinates with respect to time and DNS (a) F = 4.102; p= .005 indicating patients having DNS to the left had more reduction in volume of right inferior turbinate from Preoperative to Postoperative 6 months than patients having DNS to the right and those without DNS.(b) F = 5.011; p= .001 indicating patients without DNS had more reduction in volume of left inferior turbinate from Preoperative to Postoperative 6 months than patients having DNS to the right and those to the left. (iii) Change in volume of left inferior turbinate with respect to time and bilateral sinonasal polyposis, with F = 5.029; p= .009indicating the reduction in volume of left inferior turbinate was more among patients with bilateral sinonasal polyposis than patients without it over time. (2) Amongst the variables tested using One way ANOVA, significance was found in (i) Change in reduction of right inferior turbinate volume with respect to time and DNS, and test statistics at 3 months postoperatively with F= 4.058; p= .027 which indicates that patients with left DNS had a higher volume reduction mean score of 5.41, followed by patients with right DNS with a volume reduction mean score of 4.00 while patients who had no DNS had a lower volume reduction mean score of 2.65. At 6 months postoperatively, F= 4.263; p= .023 which indicates that patients with left DNS had a higher mean volume reduction score of 5.48, followed by patients with right DNS with a mean reduction score of 4.03, while patients who with no DNS had a lower mean score of 2.65. (ii) Change in reduction of left inferior turbinate volume with respect to time and DNS, and test statistics at 3 months postoperatively, with F= 11.402; p= .014, which indicates that patients who had no DNS had a higher mean reduction score of 6.70, followed by patients with left DNS with a mean score of 4.74, while patients with right DNS had a lower mean score of 3.62. At 6 months xvii postoperatively, with F= 4.953; p= .013, which indicates that patients with no DNS had a higher mean volume reduction score of 6.75, followed by patients with left DNS with a mean reduction score of 4.75, while patients with right DNS had a lower mean score of 2.65.(iii) Change in TNSS score distribution with respect to time and DNS , preoperatively with F = 11.402; p= .014, which indicates that the distribution of TNSS scores among patients with DNS (left or right) and among those without DNS is significant.(3) Amongst the variables tested using independent sample ‘t’ test , significance was found in change in reduction of left inferior turbinate volume with respect to time and bilateral sinonasal polyposis, at 3 months postoperatively, t= 2.183; p= .036, which indicates that patients with bilateral sinonasal polyposis had a higher mean volume reduction score of 6.70. At 6 months postoperatively, the t= 2.227; p= .033, which indicates that patients with bilateral sinonasal polyposis had a higher mean score of 6.75. Chi square test found NO significant difference in percentage of reduction in nasal symptoms in patients with or without DNS, with or without CRS, with or without polyposis, between preop and 3rd month post op. CONCLUSION: Posterior nasal neurectomy effectively alleviates symptoms of intractable allergic rhinitis with additional benefit of inferior turbinate reduction without disrupting the mucosal framework and its physiology in long run. Hence can be a recommended treatment option for recalcitrant allergic rhinitis.