ENDOSCOPIC VERSUS MICROSCOPIC APPROACH TO TYPE 1 TYMPANOPLASTY.

type of operation (ET, MT), operation time,visualization of middle ear structures ,external auditory canal widening requirement. During the postoperative follow-up, pain scale score was collected immediately after surgery, at 3 hours, and 1 day postoperatively. The graft success rate was also determined. Pain scale was scored using an 11-item, patient-reported numeric rating scale of pain intensity (NRS-11, range 0 to 10) 7 . Graft success as well as healing status of the EAC was evaluated at 3 months. Tympanoplasties were performed under Local Anasthesia. Temporalis fascia was used as graft material in all microscopic and endoscopic tympanoplasty . Microscopic tympanoplasty were operated by post aural Approach. Endoscope assisted tympanoplasty were done through permeatal Approach. Zero degree & 30 degree 4 mm wide 10 cm long Hopkins rod endoscopes were used. All endoscopic surgeries were performed by direct visualization on the monitor. Postoperative follow-up evaluations were performed after 1, 3, and 6 months; they included pure tone audiometry, and endoscopic or microscopic evaluation of the status of the graft. Hearing thresholds, including air conduction threshold and bone conduction threshold, were evaluated by the averages at 0.5, 1.0, and 2.0 kHz. The air-bone gap (ABG) was also calculated in each examination. Final assessment of graft uptake was done at 3 months and hearing was assessed by postoperative Pure tone audiometry. Successful results were to be considered as patient having complete graft uptake and post operative air bone


Methods:-
A prospective study was conducted at SCB medical college, Cuttack between June to December 2016.Patients attending ENT outpatient department with chief complain of decreased hearing and ear discharge were screened. Those patients having dry central perforation were chosen for the study.82 patients were taken up for the study. All patients had detailed clinical examination, endoscopic examination, pure tone audiometry, as preoperative work-up and had postoperative follow-up with endoscopic or microscopic examination and pure tone audiometry at 3 months after surgery . Patients were randomly divided into two groups. Group A consisting of 38 patients underwent endoscopic tympanoplasty and Group B consisting of 44 patients underwent microscopic tympanoplasty. Either microscopic or endoscopic tympanoplasty were performed by experienced otologists.
Pure tone audiometry tests were performed at preoperatively and 3 months postoperatively. Hearing thresholds including air conduction and bone conduction were measured at 0.5, 1.0, 2.0 kHz, and the pure tone averages were calculated. TM perforation size was expressed as a percentage of the entire TM area using Image J software (National Institutes of Health, Bethesda, MD, USA) 6 . X-ray mastoid was done to know the cellularity of mastoid. Detailed operative data were collected including type of operation (ET, MT), operation time,visualization of middle ear structures ,external auditory canal widening requirement. During the postoperative follow-up, pain scale score was collected immediately after surgery, at 3 hours, and 1 day postoperatively. The graft success rate was also determined. Pain scale was scored using an 11-item, patient-reported numeric rating scale of pain intensity (NRS-11, range 0 to 10) 7 . Graft success as well as healing status of the EAC was evaluated at 3 months. Tympanoplasties were performed under Local Anasthesia. Temporalis fascia was used as graft material in all microscopic and endoscopic tympanoplasty . Microscopic tympanoplasty were operated by post aural Approach. Endoscope assisted tympanoplasty were done through permeatal Approach. Zero degree & 30 degree 4 mm wide 10 cm long Hopkins rod endoscopes were used. All endoscopic surgeries were performed by direct visualization on the monitor.
Postoperative follow-up evaluations were performed after 1, 3, and 6 months; they included pure tone audiometry, and endoscopic or microscopic evaluation of the status of the graft. Hearing thresholds, including air conduction threshold and bone conduction threshold, were evaluated by the averages at 0.5, 1.0, and 2.0 kHz. The air-bone gap (ABG) was also calculated in each examination. Final assessment of graft uptake was done at 3 months and hearing was assessed by postoperative Pure tone audiometry. Successful results were to be considered as patient having complete graft uptake and post operative air bone gap ≤15 dB. Those patients not fulfilling above criteria were considered as failure.     The average operation time in ET group 53 minutes and in MT group was 64.2 minutes with a statistical significance. EAC widening was not necessary in the ET group and was performed in 3 patients in the MT group. Graft failure was found to be equal for both the groups.

Results:-
The main goals of treatment for COM are to relieve symptoms, rehabilitate hearing, and minimize complications and drainage. Conventionally,tympanoplasty is performed under an operative microscope.The main advantages of the microscopic approach are stereo vision and bimanual handling. However, despite providing direct exposure, microscopes require frequent adjustment and may still not be sufficient when encountering protruding structures, particularly the anterior wall. Ayache reported a graft success rate of 96% in patients undergoing transcanal endoscopic cartilage tympanoplasty, and this procedure was reportedly a minimally invasive, safe, and effective treatment method. 8 This finding is similar to that of ours. In a study conducted by Furukawa et al 9 the circumference of the perforation could not be confirmed with a microscope before denuding in 12.0% of cases. Furthermore, the entire perforation was not visible in 20.0% of cases after refreshing the edges. The ear canal is narrow or protruding.Using a thin, rigid endoscope, a surgeon can perform minimally invasive procedures with protection of the anatomy, which allows for functional reconstruction during surgery . When exploring the middle ear, the endoscope approach can provide more information regarding the orifice of the tube, the incudostapedial joint, and the round-window niche, which are usually difficult to observe under an operating microscope.The advantages of the endoscopic approach also include a decrease in the operative time, which results in a decrease of the duration of anesthesia and related side effects, and a lower effect on the surgeon's concentration. In a study by Ghaffar et al. 10 the mean operative time was 62.85 minutes among 34 patients who underwent endoscopic tympanoplasty. In our study, the mean operative time among the cases those received the endoscopic approach was 53.4 minutes, compared to 64.2 minutes for the microscopic approach;this shows a significant difference. In our institution, the preparation of the microscope and the time to harvest the graft and adjust the microscope were the major factors responsible for this difference. A higher level of experience can shorten the duration of surgery.Besides the patients who were operated through the endoscopic approach complained of lesser post-operative pain and were cosmetically more satisfied than those operated with the microscope.

Conclusion:-
The use of endoscope in type-1 tympanoplasty can be advocated as an alternative approach to the use of microscope.