Clinical Application Of Endoscopic Sublabial Transmaxillary Approach In Resection Of Lateral Skull Base Tumour

Object With the continuous improvement of surgical technique and auxiliary equipment,endoscopic surgery has been widely recognized as an important method of resecting tumor in the middle line of the skull base.Further more,the region of the current endoscopic skull base surgery has extended to lateral skull base,while the surgery is confined to using endonasal approach.Serious nasal structure damage,multifarious complications and limited exposion of lateral skull base are the fatal flaws of endonasal approach.On the basis of anatomical study and clinical exploration,we try to apply endoscopic sublabial transmaxillary approach(ESTA)to resecting lateral skull base tumor,aiming to explore the individual surgical indications,techniques,advantages and disadvantages,development and evolution of ESTA,avoid the disadvantages of endonasal approach.Method On the basis of early anatomical study,ESTA was tentatively used to resect 9 skull base tumors during 10/2014 to 12/2016.Data of patient general condition,property and location of tumors,blood supply and volumes of tumors,adjacent anatomy relationships of tumors,open areas of anterior wall of maxillary sinus,intraoperative blood loss,resection rates,operation times,complications,follow-up effects are summarized.The following points are discussed detailedly:The personalized design and tailoring for each surgery plan,the main points and adjustion of specific surgery operation,the possilbe applying strategies of ESTA and its development and evolution.Result The general conditions of all patients are well(KPS>70).All cases involve pterygopalatine fossa(PPF),5 cases involve infratemporal fossa(ITF),4 cases involve middle cranial fossa.The open areas of anterior wall of maxillary sinus range from 2.5×1.5cm2 to 3×2.5cm2(avg.5.11cm2).Tumor volumes range from 4.14 to182.7cm3(avg.54.2cm3).Execpt 1 cystic tumor,all of the tumors are significantly enhanced on MRI,which indicates the blood supply is abundant.This character is corresponding to the finding during operation.Intraoperative blood loss range from 100 to 2500ml(avg.717ml).1 non-hodgkin lymphoma is resected subtotally,on account of that the internal carotid artery and more than one cranial nerves in cavernous sinus are wrapped in the tumor.Other operations are successful.Postoperative image reviews display that the tumors are removed totally in 8 patients,subtotally in 1 patient.Pathology:5 schwannomas,1 malignant neurofibroma,1 epidermoid cyst,1 non-hodgkin lymphoma,1 chordoma.No recurrence and death is found during 3-26months(avg.9.7 months)follow-up.All patients have different level of facial hypoesthesia on effected side.Conclusion Compared to endonasal approach,ESTA provides shortest path,better directly exposion and flexible operation space for resecting the tumor in pterygopalatine fossa and infratemporal fossa.With slight extention,the significant increase of surgery field and operation space in lateral infratemporal fossa could be acquired,without nasal complications.ESTA may be regard as an ideal approach for endoscopic surgery of lateral skull base tumor.Combined using ESTA and endonasal approach,the scope of endoscopic surgery could include all skull base areas.