Reconsideration Of Indications Of Maxillary Swing Approach In Endoscopic Era

ObjectiveHernandez initiated a transfacial approach through swinging the maxilla into the posterior maxilla,pterygoid bone,ethmoid sinus,sphenoid sinus,clivus and nasopharynx,which was named as maxillary swing approach.In 1991,Wei et al.reported for the first time that the tumors of infratemporal fossa,pterygopalatine fossa,nasopharynx and sphenoid sinus were removed by maxillary swing approach.Later,this approach was used by scholars at home and abroad to treat tumors invading inside and outside the skull base,and some achievements were made.With the development of endoscopic technology,in the removal of some specific tumors,the widely used endoscopic technology had a tendency to gradually replace the maxillary swing approach,and had the advantages of less trauma and no facial scars,which was more acceptable to patients.However,endoscopy also had its limitations,and it was more appropriate to remove some specific tumors by maxillary swing approach.There was little research on this aspect.We retrospectively analyzed the case data of the patients with maxilla swing surgery in our hospital,and discussed the surgical indications of maxillary swing approach in the endoscopic era.MethodsFrom January 2006 to January 2019,the clinical data of 50 patients who underwent resection of skull base communicating tumors through maxillary swing approach in Cancer Hospital of Chinese Academy of Medical Sciences were collected and analyzed retrospectively.The skull base was divided into the midline region and the lateral region by making a sagittal plane parallel to the cerebral falx with the root of the pterygoid process.According to the nature and characteristics of tumor and the results obtained after operation,the indications of maxillary swing approach and its advantages over endoscopic surgery were discussed.We separated the benign and malignant tumors.Kaplan-Meier method was used for survival analysis,and Log-rank method was used for univariate analysis.The factors with statistical significance(p<0.05)in univariate analysis and the factors that conventional experience thought would affect Progress-Free survival(PFS)were included in multivariate analysis,and COX model method was used for multivariate analysis.ResultsThere were 50 cases,and the incidence of male patients(28 cases,56%)was slightly higher than that of female patients(22 cases,44%).23(46%)patients were relapsed.The average age at the time of diagnosis was 45.8 years(range 12-67 years).The average duration of symptoms before operation was 12.5 months(range,0.5-72 months).The most common symptoms,chief complaints and signs include headache(8 cases,16.0%),paralysis of extraocular muscles(8 cases,16.0%),nasal stenosis or obstruction(6 cases,12.0%),facial numbness or pain(5 cases,10.0%),nosebleed or effusion(4 cases,8.0%).Tumors were located in lateral area in 26 cases,midline area in 12 cases and trans-regional growth in 12 cases.3 patients received chemotherapy before operation,and 16 patients received radiotherapy before operation.All tumors were resected by maxillary swing approach.45 cases of tumors were totally resected,and all the malignant ones sent for examination reached the goal of clear margin.18 of them can be removed in en bloc resection.There were 34 malignant tumors(68.0%),and the most common ones included squamous cell carcinoma(6 cases,12.0%),chordoma(6 cases,12.0%),adenoid cystic carcinoma(4 cases,8.0%),adenocarcinoma(3 cases,6.0%)and malignant peripheral nerve sheath tumors(WHO Ⅲ)(3 cases,6.0%).There were 16 benign tumors(32.0%),10 schwannomas(20.0%),3 meningiomas(6.0%),1 pituitary tumor(2.0%),1 fibrous dysplasia(2.0%)and 1 simple cyst(2.0%).One patient died of meningitis after operation.After operation,all patients had slight loss of facial sensation,8 cases had permanent facial numbness/pain,and 1 case had permanent unilateral visual field defect.5 cases of palatal fistula,5 cases of cerebrospinal fluid leakage,3 cases of epistaxis and 1 case of hydrocephalus were recovered after rehabilitation treatment and lumbar cistern drainage.One case of cerebrospinal fluid leakage was relieved after undergoing skull base repair again.Another 3 cases had teeth misalignment with mild symptoms,which did not affect normal life.48 patients were followed up,and 2 patients lost follow-up after discharge.The median follow-up time was 47 months(6-177 months).The median PFS of all patients was 44 months(range,6-117 months)and the median overall survival(OS)was 47months(range,6-177 months).The 2-year survival rate of malignant tumor patients was84.0%,and the 5-year survival rate was 44.2%.The 2-year PFS rate and 5-year PFS rate were 72.5% and 56.9% respectively.Survival analysis showed that benign tumors had no PFS-related factors.In univariate analysis of malignant tumors,en bloc excision was statistically significant(P= 0.012),correlated with OS,and was still significant in multivariate analysis(P=0.021,HR 4.445,95%CI 1.252-15.784).ConclusionIn the era of endoscopy,the surgical indications of maxillary swing approach are limited to the following aspects: The tumor is huge and involves multiple skull base areas.Obvious calcification,fibrosis or recurrent tumor,so that it is difficulty in endoscopic resection.Those with abundant blood supply and complete capsule are expected to be completely removed.Low-grade malignant tumors with huge volume and are promising with radical resection.