| BackgroundParapharyngeal space (PPS) is a challenging anatomical regions hidden deep in the neck, within which contain important anatomical structures, such as the internal carotid artery, jugular vein and the cranial nerves Ⅸ-Ⅻ. Therefore the tumors occuring in the parapharyngeal space poses a challenge in preoperative evaluation, surgical planning and surgical procedures for many of Otolaryngology Head and Neck Surgeons.Recent technological innovations, such as endoscopic operation, robot surgery, adopted in other fields, has made extensive tumor resections possible through new and more conservative approaches. Using this new technology represents a new surgical approach of the parapharyngeal space tumors, which we believe should be emphasized by the surgeon. This paper reanalyzed the characteristic of the anatomy of parapharyngeal space by endoscopy-assisted transoral approach on the basis of the existing anatomy of parapharyngeal space, designed to identify the important anatomical landmark of the surgery, at the same time discussed the indications, the limits, and the criticisms of the surgical approach.Objective:The anatomy of parapharyngeal space is complex and is a challenge for clinicians. With the development of the endoscopic technology, the endoscopy-assisted transoral resection of parapharyngeal space tumors is widely used in clinic. But we still know little about the transoral perspective of anatomy of the parapharyngeal space. This article is mainly about illustrating the anatomy of transoral approach of the parapharyngeal space under endoscopy and finding the surgical landmark in the surgery.Methods:four freshly cadaver heads were dissected to illustrate the anatomy of transoral approach of the parapharyngeal space under the endoscope (Karl Storz, Germany).Results:In the oral level, the parapharyngeal space is from the medial pterygoid muscle (MPM) laterally to the superior constrictor muscle (SCM) medially. The medial pterygoid muscle is the lateral boundary of the parapharyngeal space. The superior constrictor muscle is the key point of the parapharyngeal space. It is the medial boundary of the parapharyngeal space and on the lateral aspect of it, the internal carotid artery (ICA) and anterior to this the ascending pharyngeal artery (APHA) and the ascending palatine artery (APA) are identified. In addition, the stylopharyngeus muscle (SPM) and the styloglossus muscle (SGM) also seem to be critical landmarks in the transoral approach. Posterior to these muscles, the internal carotid artery, internal jugular vein (IJV), and lower cranial nerves are identifiable.Conclusions:The endoscopy-assisted transoral approach of parapharyngeal space tumors is direct access and less morbidity. The medial pterygoid muscle, the superior constrictor muscle, he stylopharyngeus muscle and the styloglossus muscle are all the important landmarks of the surgery. BackgroundTumors of the parapharyngeal space (PPS) are rare, comprising only0.5%of head-neck neoplasms, and can be of a wide variety of histological types. The most commonly occurring tumors arise from the salivary gland, while neurogenic tumors occur less frequently. The anatomic characteristics of the PPS make clinical examination of this area a difficult and unreliable method of tumor assessment.From a pathologic point of view, in the parapharyngeal space, rare primary tumors usually arise which are mostly benign, and this aspect strongly influences the surgical choice. The ideal gold standard approach for parapharyngeal space tumors (PST) should be, at the same time, the widest to completely remove the mass with no remnants, and the safest to reduce to a minimum the postsurgical functional and aesthetic sequelae. Therefore a variety of surgical approaches have been described for the management of parapharyngeal space tumors. The more common among them include the transcervical approach, the transparotid approach, the transcervical-transmandibular approach, and a combination of the above. The transoral approach is the most controversial one, these days indicated in highly selected cases and sometimes even contraindicated.This paper compared the total removal rate, the operation time, blood loss, postoperative pain, hospitalized days, complication rate, scar and recurrence between the endoscopy-assisted transoral approach (EATA) and the external approach (EA) including the transcervical approach, the transcervial-parotid approach and the transubmandibular approach of surgical treatment of parapharyngeal space tumors.Objective:To compare curative effects between the resection of endoscopy-assisted transoral approach (EATA) of parapharyngeal space (PPS) tumors and the resection of external approach (EA), including the transcervical approach, transparotid approach and transubmandibluar approach. Meanwhile, analysis the indication, contraindication, surgical skills, advantages and disadvantages of the endoscopy-assisted transoral approach.Patients and Methods:Retrospective analysis were carried out in21patients with parapharyngeal space tumors hospitalized at Shenzhen No.2People’s Hospital from January2008to January2014. The21patients were divided into the observation group and the control group according to the tumor’s location and the relationship between tumor and adjacent structures and on the basis of the patients’permission. In the observation group (6patients), the tumors were resected solely by transoral approach under the guidance of the endoscopes (EATA), while in the control group (15patients), the tumors were resected completely using the external approach (EA) including the transcervical approach, the transcervial-parotid approach and the transubmandibular approach. We compared the total removal rate, the operation time, blood loss, postoperative pain, hospitalized days, complication rate, scar and recurrence between the two groups. Comparisons were evaluated with the t-test and Fisher exact test between the two groups, and p<0.05was considered significant.Result:In the observation group, the operation time, the blood loss and the hospitalized days was (125.00±9.10) minutes,(84.00±12.87) milliliter,(5.90±0.84)days respectively. While in the control group, the operation time, the blood loss and the hospitalized days was (128.0011.46) minutes,(235.6715.80) milliliter,(9.070.88) days respectively. All the neoplasms were completely cut.21Patients were followed up for6months to5years with no recurrence. Comparing the total removal rate, the operation time, complication rate, and recurrence rate between the two groups, there were no significant differences (P>0.05). The differences in blood loss, hospitalized days and postoperative pain had statistical sense (P<0.05) between the two groups.Conclusions:Parapharyngeal space tumors could be completely resected both by the endoscopy-assisted transoral approach (EATA) and the external approaches (EA) including the transcervical approach, the transcervial-parotid approach and the transubmandibular approach. The endoscopy-assisted transoral approach has significantly shorter hospitalized days, less blood loss and less postoperative pain than the lateral approaches. One of the biggest advantages of the endoscopy-assisted transoral approach, compared to the external approaches, is the ability to maintain facial cosmetic. And the indications of EATA are that the tumor is benign and locates medial or anteromedial to the carotid sheath and/or originating from the deep lobe of the parotid. However, the endoscopy-assisted transoral approach is not applicable for all parapharyngeal space neoplasms, such as tumors encasing the internal carotid arteries and tumors located lateral or posterolateral to the carotid sheath. On the basis of these results, the EATA is worth to encourage a more extensive clinical use in the treatment of parapharyngeal space tumors (PST). |
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