[Surgery technique of combined different infratemporal fossa approaches for lesions in lateral skull base]

Objective: To investigate the technical points and clinical application of combined infratemporal fossa approaches (CIFA) by analyzing the clinical results with CIFA for lesions involved skull base. Methods: A retrospective study was performed on 11 patients underwent CIFA for skull base lesions dissection from December 2014 to January 2019 in the department of otolaryngology, Peking Union Medical College Hospital. There were 6 male and 5 female patients, with age range of 16-72 years old and median age of 53 years old. Five patients underwent CIFA Type B and D, and the other 6 underwent CIFA A and B. All patients were followed up regularly by CT and MRI to observe possible recurrence. Results: Among the 5 patients with CIFA Type B and D, 3 were giant cell tumor and 2 were giant cell reparative granuloma, and median maximum cross-section size was 42 mm×46 mm (range from 37 mm×18 mm to 56 mm×53 mm). Among the 6 patients with CIFA Type A and B, 4 were paraganglioma of head and neck, 1 was schwannoma of skull base, 1 was petrous cholesteatoma, and median maximum cross-section size was 43 mm×36 mm (range from 24 mm×22 mm to 63 mm×35 mm). Nine patients underwent complete resection of the tumor in the first stage. In 2 patients, the extracranial parts were removed in the first stage, and the intracranial part was removed in the second stage. Tympanum and ossicular reconstruction were done in one of the CIFA Type B and group D, and 1 year's postoperative hearing was mild conductive hearing loss. There was no cerebrospinal fluid leakage of all patients. All the 5 patients with normal facial nerve function before surgery recovered to H-B grade Ⅰ to Ⅱ within 3 months after surgery. Among the 4 patients whose preoperative facial nerve function were grade Ⅱ, 2 recovered to grade I after surgery and the other 2 were still grade Ⅱ. For the patient whose preoperative facial nerve function was grade Ⅴ, his postoperative recovery was grade Ⅲ. There was 1 patient whose pre-operative FN function was H-B grade Ⅲ, and the post-operative FN function was grade Ⅵ due to FN resection. Except for 2 cases with cochlear involved before surgery, cochleae of the other 9 cases were preserved. The follow-up time was 14 to 58 months. No recurrence was observed in all patients. Conclusions: The CIFA can safely and completely remove the extensive lesions that invade the skull base, and the facial nerve function can be well protected and recovered intro-and post-operation. Appropriate use of combined IFA can not only achieve good exposure and complete resection of lesions, but also create conditions for functional reconstruction.