Materials and Methods:
A retrospective cost analysis study was conducted, in an NHS district general hospital setting. The direct costs involved in a patient journey for a total endoscopic approach to management of an attic cholesteatoma were compared to those for a microscopic combined approach tympanoplasty. Indirect and future costs were excluded.
A retrospective chart analysis was carried out for 10 consecutive cases of attic cholesteatoma who were managed with a total endoscopic approach and 10 consecutive cases managed with a combined approach tympanoplasty between 2017 and 2019, at the same institution and under the care of the same consultant surgeon. Only cases where the cholesteatoma did not extend beyond the posterior limits of the lateral semi-circular canal or below the inferior limits of the stapes supra-structure were included.
The patients’ health journey was mapped (figure 1) to identify resources for comparison, similar to a previously described study (4). There was an initial overlap of required resources in the diagnostic work up of patients, which were not included in our final analysis. A comparison of the direct costs involved in the surgical set up, anaesthetic set up and operation theatre running costs was made.
Total endoscopic ear surgery was defined as transcanal surgery performed completely using an endoscopic with no use of an operating microscope. Hypotensive anaesthesia was given using remifentanil and desflurane. Endoscopic atticotomy was performed in all ten cases using 0 and 45 degree 4mm rigid endoscopes and a curette. A composite tragal cartilage-perichondrium graft was used for reconstruction of the tympanic membrane and the attic defect in all endoscopic cases. Post-operatively, the canal was packed with chloramphenicol ointment. No head dressing was applied, and the surgery was done as a day case.
Microscopic ear surgery was defined as a postaural approach combined approach tympanoplasty involving a cortical mastoidectomy and a posterior tympanotomy in all ten cases. Hypotensive anaesthesia was given using remifentanil and desflurane. The postaural incision was made using a handheld diathermy, and the mastoidectomy and tympanotomy were done using a drill and an average of 4.5 different size burrs (Medtronic). Temporalis fascia and conchal cartilage were used for reconstruction. Post-operatively, the skin was closed using skin clips, and the canal was packed with bismuth subnitrate and iodoform paraffin paste impregnated gauze (BIPP dressing). A head dressing was applied for 24 hours, and the patient was admitted overnight.
Data regarding the operative set up costs and intraoperative consumables used were obtained from theatre staff. The operating theatre running costs (£1200 per hour) were obtained from hospital management, and included an hourly cost based on staffing, quality control, utilities, land rent and building depreciation. The average surgical time for both procedures was calculated using data available from operating theatre records for the consultant surgeon, and was used to calculate the cost of anaesthetic agents used and operation theatre running costs.
Statistical analysis was done using a two sample t­-­ test to compare the endoscopic and microscopic surgical groups.