title: Minimally invasive inlay and underlay tympanoplasty.
abstract: OBJECTIVE
  The objective of this study is to understand the outcome of minimally invasive topical anesthetized transcanal inlay and underlay tympanoplasty, and to compare these 2 procedures in hearing result, take rate, perioperative pain, and operation time.
  
  
  METHODS
  This is a retrospective study conducted from September 2003 to December 2006. Forty-eight tympanoplasty in 46 patients, 28 inlay and 20 underlay procedures, with small- to medium-sized tympanic membrane perforations without middle ear lesion, were studied in a tertiary referral center. Interventions included otologic examination, perioperative hearing evaluation, local anesthetized transcanal inlay, or underlay tympanoplasty. The outcome measurements were the following: the take rate and audiometric result at the last follow-up visit, perioperative pain, and duration of surgery. The statistical methods used were t test, Mann-Whitney U test, chi(2) test, and Fisher exact test.
  
  
  RESULTS
  The take rate were 82.1% in the inlay group and 85% in the underlay group, without significant difference (P = .79) at the last follow-up visit. Air-bone gap closure was 6.3 +/- 2.5 dB in the inlay group and 9.3 +/- 3.2 dB in the underlay (P = .07). Linear analogue scale of perioperative pain was lower in the inlay group with significance (1.7 +/- 1.2 in the inlay and 4.6 +/- 1.9 in the underlay group, P < .001). The duration of the surgery was significantly shorter in the inlay group (31.8 +/- 13.9 minutes for the inlay group and 75.9 +/- 14.6 minutes for the underlay group, P < .001).
  
  
  CONCLUSIONS
  Minimally invasive topically anesthetized transcanal tympanoplasty provides satisfactory surgical and audiometric outcome both in inlay and underlay procedures. The take rate and extent of hearing recovery are similar in both groups. However, inlay tympanoplasty is superior to transcanal tympanoplasty because of less discomfort and shorter operation time.
authors.affiliation: Department of Otolaryngology-Head and Neck Surgery, Chang Gung Memorial Hospital, Pu-Tzu City, Chiayi County, Taiwan.
authors.forename: Wen-Hung
authors.initials: WH
authors.lastname: Wang
authors.forename: Yen-Chun
authors.initials: YC
authors.lastname: Lin
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001299:Audiometry; D001309:Auditory Threshold; D015331:Cohort Studies; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D019060:Minimally Invasive Surgical Procedures / Q000379:methods*; D010149:Postoperative Pain / Q000503:physiopathology; D017060:Patient Satisfaction; D011336:Probability; D012189:Retrospective Studies; D018570:Risk Assessment; D012720:Severity of Illness Index; D018709:Statistics, Nonparametric; D013997:Time Factors; D016896:Treatment Outcome; D018058:Tympanic Membrane Perforation / Q000175:diagnosis / Q000601:surgery*; D014433:Tympanoplasty / Q000295:instrumentation / Q000379:methods*; D055815:Young Adult