Modern surgical treatment of otosclerosis - Helda - Helsinki.fi

More documents

Recommendations

Info

Materials and methods A drop of blood was used as a sealing material after stapedotomy. All surgeries were performed with local anaesthesia using an endaural incision. Study III included 29 stapedotomies done with a laser (21 ears) or a micro-drill (8 ears). In four cases, a partial stapedectomy was performed due to an unintended fracture of the footplate. Piston prostheses were applied and small pieces of fascia (n=19), fat (n=3), or blood (n=11) were used as a sealant. All but one patient received local anaesthesia. In Study IV, 19 of the procedures were performed using a local anaesthetic, and in two cases a general anaesthetic was preferred by the patient. The surgical approach was either transcanal (18 ears) or endaural (3 ears). Stapedotomy was performed with a laser on four patients and with a micro-drill on 16 of the patients. A titanium piston prosthesis with a diameter of 0.4-0.6 mm was applied and small pieces of fascia or blood were used as a sealant. One patient had cholesteatoma, which had previously been operated on and the ossicular chain had been reconstructed with incus interposition. The interpositioned incus was removed and the stapes footplate was found to be mobile but fractured. A reconstruction was done using a titanium total ossicular replacement prosthesis and cartilage. Three patients in Study III and one in Study IV lived alone and were scheduled as inpatients, but all other patients were scheduled as outpatients. 4.3 Objective measurements and analysis Video-oculography Eye movements were recorded using a rubber mask-mounted video camera in a dimly lit room (Figure 1). The other eye was either uncovered, allowing vision, or covered. Eye position curves for horizontal and vertical planes were calculated by using software (2D VOG, Version 3.0, Sensomotoric Instruments, Berlin, Germany). The recordings were also stored on a standard VHS videotape, allowing visual evaluation of the rotatory component. The nystagmus was characterized by maximal slow phase velocity (SPV) and direction. During the VOG, the patients were prone and their heads were faced straight ahead. We first recorded spontaneous nystagmus with one eye uncovered. We then measured spontaneous nystagmus with the gaze forward, the gaze approximately 30 º to the left or right, and after 20 seconds of passive head shaking with the eyes covered. In Study IV, the head shaking provocation was not done. Each test condition lasted 30 seconds, and for a positive finding, at least five nystagmus beats were required. The limit for an abnormal SPV was 1 º/s for horizontal and 2 º/s for vertical components of spontaneous nystagmus. After head shaking, the corresponding normal limits were 6.1 and 6.8 º/s. The normative values were based on a previous study of healthy persons using the same equipment (Levo et al. 2004). 44
Materials and methods Study III included 33 patients. On 11 of these patients, preoperative VOG was performed. Most of the patients had VOG measurements taken at one week (27 patients) and one month (28 patients) after the operation. Nineteen of the patients were also measured 3-4 months postoperatively. Patients in Study IV had a single recording on average four hours postoperatively. Visual feedback posturography The vestibular function of patients with bilateral otosclerosis was measured using visual feedback posturography (VFP) in Study I. The VFP equipment was a custom-made force platform described in detail in Hirvonen et al. (2002) (Figure 2). While standing on the platform, the patient’s center of gravity (COG) was calculated and movement of the COG marker was displayed on a computer screen. Patients were instructed to move their COG marker by leaning their body as fast and as accurately as possible to given targets shown one at a time on the computer screen. A balance index (BI) was calculated by dividing hit delay (s) to the targets with hold percentage (%) within the targets. VFP was performed preoperatively as well as at one week, three months and one year after surgery. According to our previous study, a BI ≤ 2.5 s/% is considered normal (Hirvonen et al. 2002). Audiogram The audiological examinations were carried out using a clinical audiometer, calibrated according to ISO standards. Mean thresholds at frequencies of 0.5, 1, 2 and 4 kHz were used to calculate four-tone pure-tone average (PTA). Air conduction (PTA-AC) and bone conduction (PTA-BC) thresholds were recorded, and the air-bone gap (AB-GAP) was calculated. The postoperative AB-GAP was calculated by subtracting the postoperative BC from the corresponding AC. To analyse possible inner ear damage, mean preoperative BC at 1, 2 and 4 kHz minus postoperative BC values was used to calculate overclosure in Studies I, III and IV. Speech discrimination audiograms were performed pre- and postoperatively in Study I. Statistical analysis Statistical analysis was performed with SPSS version 11.0 or later software (SPSS Inc., Chicago, IL, USA), and a p-value of ≤0.05 was considered statistically significant. Audiometric data were analysed using paired Student’s t-test (I-II) or paired Wilcoxon signed-rank test (IV) to compare results within groups. An unpaired t-test (II) or nonpaired Mann-Whitney test (IV) was used to compare differences between groups. For noncontinuous parameters, Kendall’s W-test was used in Study I and Mann-Whitney U-test in Studies II and III. In Study IV, χ2 -test was used to compare the prevalence of nystagmus 45
Page 1 and 2: Department of Otorhinolaryngology U
Page 3 and 4: To my Family
Page 5 and 6: Stapedius tendon preservation 29 Re
Page 7 and 8: List of original publications The t
Page 9 and 10: Abstract Abstract The era of modern
Page 11 and 12: Tiivistelmä (Finnish summary) Tiiv
Page 13 and 14: 1 Introduction Introduction Otoscle
Page 15 and 16: 2 Review of the literature 2.1 Defi
Page 17 and 18: Clinical otosclerosis Review of the
Page 19 and 20: Review of the literature examinatio
Page 21 and 22: Review of the literature hearing lo
Page 23 and 24: Otosclerosis and Meniere’s diseas
Page 25 and 26: Review of the literature is positiv
Page 27 and 28: Review of the literature and light-
Page 29 and 30: Review of the literature shorter wa
Page 31 and 32: Review of the literature The analys
Page 33 and 34: Review of the literature Twenty-eig
Page 35 and 36: Review of the literature demonstrat
Page 37 and 38: Review of the literature disturb th
Page 39 and 40: Review of the literature images. In
Page 41 and 42: 3 Aims of the study Aims of the stu
Page 43: Studies III and IV Materials and me
Page 47 and 48: Materials and methods Figure 2. Vis
Page 49 and 50: Results and comments improved signi
Page 51 and 52: Results and comments Table 3. Heari
Page 53 and 54: Results and comments A final follow
Page 55 and 56: Results and comments spontaneous ho
Page 57 and 58: Discussion The patient also would a
Page 59 and 60: Discussion surgeries are suitable f
Page 61 and 62: Discussion Patients with vestibular
Page 63 and 64: 7 Conclusions Conclusions Audiologi
Page 65 and 66: Acknowledgements Most of my writing
Page 67 and 68: References Baloh RW, Honrubia. Clin
Page 69 and 70: References Dahlqvist A, Diamant H,
Page 71 and 72: References Gersdorff M, Nouwen J, G
Page 73 and 74: References Jablokow VR, Kathuria S.
Page 75 and 76: References Markou K, Goudakos J. An
Page 77 and 78: References Perkings RC. Laser stape
Page 79 and 80: References Shabana YK, Ghonim MR, P
Page 81 and 82: References Toner JG, Smyth GDL. Com
Page 83 and 84: Appendix Questionnaire used to asse

Modern surgical treatment of otosclerosis - Helda - Helsinki.fi

You also want an ePaper? Increase the reach of your titles

Delete template?

Save as template?