Use of cross-sectional imaging in predicting facial nerve sacrifice during surgery for parotid neoplasms

BACKGROUND: Neoplasms of the parotid gland are difficult management issues because of the wide variation in their biological behavior and the potential for sacrifice of the facial nerve during resection. Because of the significant associated morbidity, prediction of facial nerve sacrifice is critically important for planning surgical procedures and preoperative counseling of patients. We hypothesize that along with the knowledge of the tumor type we would be able to accurately predict the likelihood of facial nerve sacrifice using cross-sectional imaging. METHODS: All patients included in this study were previously untreated patients with parotid neoplasms operated on between January 1997 and July 2002. Only those patients with an available preoperative imaging were included and this resulted in 44 patients for review. Nine patients with preoperative deficits in facial nerve function were excluded from this study since these patients would require facial nerve sacrifice regardless of the radiological prediction. The prediction of facial nerve sacrifice was determined using a prediction of tumor location and an algorithm. The predicted results were compared to the operative record. RESULTS: For all lesions, cross-sectional imaging predicted the need for sacrifice of the facial nerve with a sensitivity of 0.83 (95% CI, 0.36-0.99), specificity of 0.90 (95% CI, 0.72-0.97), PPV of 0.63 (95% CI, 0.26-0.90), and NPV of 0.96 (95% CI, 0.79-0.99). For malignant lesions only, prediction of sacrifice of the facial nerve had a sensitivity of 0.83 (95% CI, 0.36-0.99), specificity of 0.80 (95% CI, 0.51-0.95), PPV of 0.63 (95% CI, 0.26-0.90), and NPV of 0.92 (95% CI, 0.62-0.99). CONCLUSION: Cross-sectional imaging and application of our algorithm is a sensitive method for identifying patients with parotid neoplasms who require facial nerve sacrifice. CT and MRI have a high negative predictive value for facial nerve sacrifice.     

颞骨CT三维重建面神经立体解剖定位

目的:探讨基于PC机的颞骨CT三维重建在面神经解剖定位中的方法和应用价值,总结出一套量化的研究面神经定位的方法,以便指导耳科及侧颅底手术。方法:使用3D-DOCTOR软件对成人轴位CT影像进行三维重建,显示颞骨内各重要结构的形态及其相互间复杂的立体关系。并用软件自带的功能测量面神经及其毗邻结构之间的距离和相对角度。分析测得的数据,总结面神经与其毗邻解剖标志结构之间的相对关系。结果:重建获得清晰的三维图像,包括面神经、鼓环、听小骨、匙突、锥隆起、内听道、耳蜗、半规管、颈静脉球窝、颈内动脉管等颞骨内结构。准确测量三维模型所得的面神经及其毗邻结构之间的相关参数并发现一定的规律性,这非常有益于手术中进行面神经快速定位和手术入路的设计。结论:基于PC机的颞骨CT三维重建可以准确地显示其内部各解剖结构及其相互间的空间立体关系,并可进行测量定位。     

颈交感神经鞘瘤CT表现与手术对照研究

目的 探讨CT在术前诊断颈交感神经鞘瘤(SSN)的价值。〖HTW〗方法 回顾性分析16例经手术和病理检查证实为颈交感神经鞘瘤患者的CT资料。分别对病变部位、肿块大小、边界、强化作出判断。重点分析在CT轴面上SSN与颈总、内动脉及颈内静脉的位置关系。对照研究病变的定位与手术所见。结果 肿块均呈膨胀性生长,周围结构呈受压推移改变。10例表现为内密度不均,不均匀强化。6例表现为低密度区内散在不规则结节状、云团状或烟雾状高密度强化影。CT增强扫描示10例次颈总动脉移位于肿瘤的外半周的前半侧; 16例次颈内动脉被推移于肿瘤的外半周的偏后侧。14例显示颈内静脉受压、变形并移位于肿瘤的外半周,颈内静脉皆移位于颈总(内)动脉的外后;动静脉相互靠近或分离不超过90°。手术中所见血管移位关系与此相一致。结论 CT仍能较准确地反映颈交感神经颈总(内)动脉及颈内静脉等原有的解剖定位关系。根据典型血管移位关系对本病作出术前诊断具有一定的价值。     

Ligation of the external carotid in the parotid space. Its surgical significance

The classical procedure of external carotid artery ligature in the carotid sulcus presents certain difficulties: The subdiagastric lymph nodes and branches of farabeuf's venous trunk must be avoided, and major nerves and vessels, including the hypoglossal nerve, internal carotid artery, and internal jugular vein, identified and protected. An approach to the external carotid artery at its entry into the parotid space, as employed in parotidectomy, avoids such problems due to major anatomical elements. This technique appears to be simpler, less restrictive, and more rapidly accomplished than the classical method of ligature, when its objective, the most frequent one, is arrest or prevent ion of hemorrhage in the region supplies by the internal maxillary artery.     

Nuclear magnetic resonance tomography in the diagnosis of parotid tumors. A comparison of methods

The diagnostic value and the limitations of magnetic resonance imaging (MRI) in the management of large parotid masses were evaluated in a prospective clinical study. The results were compared with computed tomography (CT) and B-mode ultrasonography (US). MRI was performed using a Siemens 1.5 Tesla Magnetom with a RF head coil and surface RF coils. The images were evaluated by the following parameters of clinical importance: tumour detectability and marginal appearance, internal architecture, regional extension, and artifact degradation. MR imaging of parotid masses was superior to CT and US for the following reasons. The marginal appearance of the tumour was sharp and further enhanced in T2 weighted pictures. The extension of the tumour can be well seen by use of transaxial and frontal projections. This is an advantage especially when the mass extends to the retromandibular fossa or even to the pterygopalatine fossa. The position of the jaw, external ear canal, mastoid, skull base, and vessels of the neck are clearly shown without artifact degradation. Benign neoplasms can be well differentiated from malignant tumours which show local infiltration into the adjacent anatomical structures as well as irregularities of their internal structure. However, their appearance in MRI can be identical to that of an acute inflammation of the parotid gland. In summary MRI is the imaging technique of choice for extensive parotid masses, whereas US is effective for small tumours not situated in the retromandibular fossa.     

Facial nerve: vascular-related anatomy at the stylomastoid foramen

We dissected 30 facial nerves in fresh cadavers after arterial casting with red latex to provide specific information about the arterial-related anatomy of the trunk of the facial nerve from the stylomastoid foramen to its bifurcation. We found that a wide anatomic variability does exist. The trunk of the facial nerve was in proximity to the stylomastoid artery, which originated from the posterior auricular artery in 70% of the specimens (21/30), from the occipital artery in 20% (6/30), and directly from the external carotid artery in 10% (3/30). The stylomastoid artery passed medially to the trunk of the facial nerve in 63 of the specimens (19/30) and laterally in 37% (11/30). Among these 11 specimens, 8 were large-caliber stylomastoid arteries. During parotid surgery, the main trunk of the facial nerve may be difficult to identify, because a large-caliber stylomastoid artery can mask it. Therefore, it is important to dissect this artery with caution.     

Unusual primary and secondary facial blast injuries

PURPOSE: To discuss unusual facial injuries resulting from a bomb blast. MATERIALS AND METHODS: In March 1997, a bomb consisting of a bag of nails was detonated in a coffee shop in Tel Aviv. Two of the wounded were brought to our level 1 Trauma Center with unique facial injuries. Computed tomography (CT) scan and CT angiogram were performed. RESULTS: The blast occurred to the immediate right of the victims who were sitting in an open cafe. Both had tympanic perforation. The first patient showed indirect damage to the facial nerve from a piece of shrapnel located anterior to the carotid artery and medial to the right mandibular angle. The second had a piece of shrapnel lodged in the parapharyngeal space that was initially missed and discovered only on reexamination 3 days later after the patient complained of pain in the temporomandibular joint; there was no facial nerve deficit. The port of entry was probably a small wound in the anterior wall of the external ear canal. CONCLUSIONS: The wounds are probably attributable to the spalling effect of the shrapnel passing through the parotid gland, which has mixed-density tissue. These cases show that nerves are susceptible to damage even in the absence of direct engagement and that the emergency room physician should be alert to even small skin imperfections in blast victims to avoid missing penetrating wounds.     

Evaluation of parotid lesions by magnetic resonance imaging

The effectiveness of magnetic resonance (MR) imaging in the evaluation of parotid lesions was tested by scanning 21 patients with parotid masses. In 20 patients the lesion was visualized, and in 19 benign/malignant differentiation was accurately made, indicating sensitivity and specificity of .95. The deep extent of the lesions was readily assessed by MR but the facial nerve could not be identified.     

颈动脉体瘤的个体化序贯治疗应用评价

目的探讨颈动脉体瘤的个体化序贯治疗。方法回顾性分析1999年1月～2009年7月诊治的23例(29侧)颈动脉体瘤患者,其中单侧颈动脉体瘤17例,双侧6例;经确诊后采用术前Matas试验-BOT试验-手术的序贯治疗方式。手术方法包括瘤体剥脱、瘤体与颈外动脉同时切除、颈内动脉切除后颈外动脉与颈内动脉远心端吻合或颈内动脉自体血管重建及颈内动脉单纯结扎。结果患者术前Matas试验结果:能持续按压阻断30 min无特殊不适者1周内17侧、2周内26侧、4周内29侧。其中2例女性患者在通过Matas训练后,于术前行BOT试验检测时出现阳性反应。所有患者颈动脉体瘤11侧肿瘤切除后动脉完好,5侧肿瘤切除同时结扎颈外动脉,6侧肿瘤切除后行颈内动脉破损直接修补,2侧肿瘤行颈外动脉与颈内动脉对端吻合,3侧肿瘤取大隐静脉及1侧取颈外静脉行颈总,颈内动脉搭桥,1侧单纯结扎颈内动脉。术后患者出现局灶性脑梗塞1例,Horner综合征5例,迷走神经麻痹6例,舌下神经麻痹3例,面神经麻痹2例,副神经麻痹1例。采用静脉重建的颈内动脉术后3～6个月复查彩超均见重建血管通畅。结论术前Matas试验-BOT试验-手术的序贯治疗方式能有效促进大脑侧枝循环建立;该序贯治疗对术中颈动脉重建是否需要采用转流手术方式提供准确依据,术中颈动脉破裂后单纯颈动脉修补及颈外动脉与颈内动脉端端吻合均不需要行颈动脉转流;仅行大隐静脉搭桥重建颈内动脉时才需要转流手术。颈动脉体瘤的个体化序贯治疗不仅避免了不转流导致造成脑缺血而产生偏瘫、昏迷等严重并发症,而且减少了盲目使用转流管所带来的血管损伤、血栓形成等风险及相关材料的浪费。     

面神经瘤误诊分析

目的总结分析面神经瘤误诊的原因，提高对面神经瘤的认识。方法1993年1月至2006年9月手术治疗的28例面神经瘤患者，11例有误诊的经历。所有患者均行CT或MRI检查、纯音测听，面神经功能的评估采用House-Brackman（HB）系统。结果11例患者被误诊。2例术前被误诊为腮腺肿块，行腮腺浅叶切除术，术中发现肿块来自面神经。4例单侧面神经麻痹长期外院误诊为贝尔面神经麻痹，病史1至8年。由于长期面神经麻痹无好转，行影像学检查发现面神经占位病变。2例复发性面神经麻痹误诊为贝尔面神经麻痹，行影像学检查发现均为面神经膝状神经节占位。1例因左耳渐进性听力下降，体检见外耳道新生物，诊断为外耳道新生物，行活组织检查示神经鞘瘤，进一步影像学检查提示为面神经瘤。1例右耳流脓数年，面神经麻痹1个月。查体示右鼓膜穿孔，CT检查诊断为慢性中耳炎行手术，术中见上鼓室肿块同面神经关系密切，取部分组织送病理，术后病理为面神经鞘瘤。另1例面神经麻痹1年半，CT检查误诊为先天性胆脂瘤，入院后发现乳突肿块同面神经关系密切，MRI证实为面神经肿瘤并且侵及腮腺内面神经。11例均经手术和病理证实。结论面神经瘤较罕见，不为大多数临床耳科医生熟悉，在临床中易被漏诊和误诊。临床中，如贝尔面神经麻痹半年内无好转现象或患者表现为反复面神经麻痹，应行影像学检查排除面神经瘤的可能。如患者出现面神经麻痹，CT示中耳占位并同面神经关系密切时，行MRI检查可同中耳胆脂瘤、肉芽、胆固醇肉芽肿等区分。腮腺肿块同面神经总干关系密切者应警惕面神经可能。     

Conservative facial nerve management in jugular foramen schwannomas

OBJECTIVE: Although transposition of the facial nerve is crucial in infiltrative vascular lesions involving the jugular foramen, the objective was to show that a conservative approach to management of the facial nerve is sufficient with jugular foramen neuromas because of their noninfiltrative, less vascular nature and medial location in the jugular foramen. STUDY DESIGN: Retrospective case review. SETTING: Tertiary, private, multiphysician, otologic practice. PATIENTS: Sixteen patients with jugular foramen schwannoma (18 procedures) treated between January 1975 and October 1995. The 8 male and 8 female patients ranged in age from 13 to 66 years (mean age 47.7 years). INTERVENTION: One-stage, total jugular foramen neuroma removal without transposition of the facial nerve, using a variety of surgical approaches. MAIN OUTCOME MEASURES: Facial nerve transposition (yes or no), House-Brackmann facial nerve grade, lower cranial nerve status, complications. RESULTS: One-stage total tumor removal was accomplished in all the cases. In 13 (72%) of the neuromas, removal was accomplished without facial nerve transposition. Transposition was performed in 2 revision cases in which scar tissue from a previous operation prevented complete control of the carotid artery and safe removal, 2 cases with large tumor extension anteriorly to the petrous apex, and 1 case with extensive involvement of the middle ear. A House-Brackmann facial nerve Grade I or II was obtained in 16 of the 18 procedures, with 1 Grade III and 1 case that remained Grade V, as it was preoperatively. CONCLUSIONS: One-stage, total tumor removal can be achieved with excellent control of the important vascular structures and without transposition of the facial nerve in a majority of jugular foramen schwannomas.     

Water-jet dissection in parotid surgery--initial clinical results

INTRODUCTION: The most frequent complication following parotidectomies is postoperative facial nerve dysfunction. In animal experiment we successfully studied the technique of water-jet-dissection for safe and functional preservation in facial nerve dissection in parotid gland surgery. The aim of the present study was to evaluate our animal experiments clinically. METHODS: Until November '99 ten patients with benign parotid gland tumors (4 female, 6 male, age 32-77 years) underwent lateral or latero-segmental parotidectomies using water-jet-dissection ("Hydro-Jet", Andreas Pein Medizintechnik GmbH, Schwerin, Germany). All operations were performed under permanent intraoperative facial nerve monitoring ("Neurosign 100", Fa. Inomed, Tenningen, Germany). The postoperative facial nerve function was measured daily by the House-Brackmann and Stennert-Paresis-Index for at least one week. RESULTS: A quick parotid gland and safe facial nerve dissection could be performed in all operations using the 120 microns-nozzle with effective working pressures from 30-50 bar. In addition strong connective tissue fibers were transected with scissors. Intraoperative facial nerve lesions did not occur and cardiopulmonary complications due to eventual cutting-fluid-resorption were not seen. After surgery all patients had a normal facial nerve function. DISCUSSION: The results of our studies showed that the technique of water-jet-dissection provides safe facial nerve dissection and preservation during parotid gland surgery. CONCLUSIONS: The tissue selective cutting qualities of the new surgical method are an excellent alternative compared to standard dissection methods in parotid surgery.     

Metastases to parotid nodes

The differential diagnosis of masses in the preauricular and retromandibular regions includes a number of diseases in addition to primary tumors of the parotid. The lesions most commonly misdiagnosed as parotid tumors are intraparotid lymph nodes involved with inflammatory or neoplastic disease. Metastatic tumors in parotid nodes are unusual but must be considered. We present 12 patients with isolated metastases to parotid lymph nodes. Nine of the patients had primary tumors in the local afferent lymphatic bed. Three patients had metastases from unknown or distant sites. The majority of tumors that metastasize to the parotid are of cutaneous origin. Six of the patients had squamous cell carcinomas, three had adenocarcinomas, two melanomas and one a small cell carcinoma. The treatment of parotid metastases from local tumors is surgical removal of the parotid and associated regional nodes with postoperative irradiation therapy in certain instances. Management of the facial nerve should follow those principles appropriate for primary parotid tumors.     

Management of lipomas arising from deep lobe of the parotid gland

OBJECTIVES: We would like to present our experience in management of lipomas arising in the deep lobe of the parotid gland, which were diagnosed and operated in our clinic from the point of complication/morbidity, and recurrence, in line with the literature. MATERIAL AND METHODS: Five patients with lipoma found in the deep lobe of the parotid gland, diagnosed and treated at our clinic in the 12-year period between March 1992 and March 2004, were included in this study. Limits of the tumors were determined by computed tomography (CT), and/or magnetic resonance imaging (MRI). Preoperative fine needle aspiration biopsy (FNAB) was also performed. Through a classic parotidectomy incision, the parotid gland was exposed. Full exposure of the facial nerve and its branches was performed. The removal of deep lobe parotid lipomas was achieved by enucleation in all cases. Postoperative complication/morbidity and recurrence were evaluated. RESULTS: The most common symptom was an otherwise asymptomatic mass on the parotid region and/or upper lateral neck. One of five patients was presented with medial displacement of the lateral pharyngeal wall, and tonsil as the additional physical finding. Preoperative radiologic evaluation results revealed that CT and/or MRI scans accurately localized 100% of the tumors in relation to the deep lobe of the parotid gland. FNAB did not enable us to make a diagnosis of lipoma in four of the cases. Total resection was achieved in all cases. Temporary facial nerve paralysis, due to the dissection of the facial nerve, did not occur in any cases. There was no recurrence of the tumors after a mean follow-up of 60 months. CONCLUSION: Assessment of the exact location of the tumor is an important consideration for selection of the appropriate surgical approach. Different from lipomas found in other locations, those observed in the parotid gland cannot be easily resected by simple dissection. Resection of these tumors requires full exposure of the facial nerve.     

腮腺癌不规范手术后的特点及再手术治疗

目的总结腮腺癌不规范手术后的特点,探讨腮腺癌不规范手术后再手术的适应证及手术方式。方法总结1 998年6月～201 0年6月在外院行腮腺癌切除术后又至我院再次手术的52例腮腺癌患者的完整临床资料,分析手术情况并对临床资料进行统计。结果病理检查证实再手术患者肿瘤残留率为82.7%（43/52）,面神经完好保存率为82.7%（43/52）,面神经分支损伤率为1.9%（1/52）,面神经部分切除率为7.7%（4/52）,面神经全切除率为7.7%（4/52）;增强CT扫描的灵敏度为86.7%（39/45）,阳性预测值为90.7%（39/43）。结论腮腺癌不规范手术后的肿瘤残留率较高,慎重的再手术很有必要。增强CT扫描检查对于发现肿瘤残留有较高的阳性预测值,对于筛选再手术患者有重要意义。     

侧颅底塑化断层解剖及计算机辅助三维重建研究

目的：探讨侧颅底结构的断层解剖学特征，为此区域的病变和手术方法的选择提供解剖学依据。方法：采用生物塑化技术制作三套冠状面侧颅底结构的薄层切片，观察测量各个层面上重要结构的位置、毗邻关系，并用计算机提取图像后进行三维重建。结果：采用塑化技术制作的切片可以清晰显示侧颅底的骨质、肌肉、血管和神经等结构。侧颅底的结构可以通过上颌窦中部切面、咽鼓管咽口切面、卵圆孔切面、咽鼓管鼓口切面和内昕道切面分别展示，通过计算机对正常人侧颅底区域塑化薄层连续切片进行信号标定、提取和三维重建，成功地获得了蝶窦、三叉神经及其分支、颈内动脉、咽鼓管的离体图像。结论：薄层断面解剖可以准确定位侧颅底区域的重要结构及相互位置关系，三维重建图像形象逼真、准确，对侧颅底外科手术具有重要的意义。     

Limitations of blood supply to the skin flap in face lift surgery]

BACKGROUND: Besides nerve injuries or hematomas, one of the main risks of face lift surgery is the development of skin necrosis. We therefore investigated which arteries contribute to the blood supply of the face lift skin flap and how extensively mobilization can be performed before arterial cutaneous circulation is endangered. MATERIAL AND METHOD: In six cadavers, selective dye injections into the branches of the carotid external artery were performed to determine the location of their vascular territories in relation to the face lift region. In another 12 cadavers, face lift flaps were raised with different extension of the undermined skin area before dye injections were performed. RESULTS: It was shown that the facial artery provides blood supply to the area of the face lift flap by perforating vessels in the paranasal, perioral and submental regions and the transverse facial artery by a perforating vessel below the malar bone prominence. Although the perforating vessel of the transverse facial artery was transected by standard mobilization, the face lift flaps were sufficiently perfused via the paranasal and perioral perforating vessels of the facial artery alone. CONCLUSION: We conclude that undermining of the face lift flap should not exceed the nasolabial fold to preserve the perforating vessels of the facial artery in the centrofacial region.     

内耳及毗邻结构三维形态学研究

目的基于颞骨CT三维重建,研究内耳及其毗邻结构的三维解剖关系,对内耳及其毗邻结构的空间立体关系进行测量定位,总结规律,为指导耳科及侧颅底手术提供参考。方法使用3D-DOCTOR软件对34例成人颞骨轴位CT影像进行三维重建,显示内耳及其毗邻各重要结构的形态及其相互间复杂的空间关系。并用软件自带的功能测量内耳及其毗邻结构之间的距离和相对角度,总结内耳及其毗邻各重要结构的距离及相对角度的规律性。结果重建获得了清晰的耳蜗、半规管、听小骨、面神经、内听道、颈静脉球窝、颈内动脉管等颞骨内重要结构三维图象。测量三维模型后准确获得了耳蜗及半规管与面神经、颈内动脉、颈静脉球之间相对关系的参数。结论颞骨CT三维重建可以明确地显示其内部各解剖结构及其相互间的空间立体关系。     

螺旋CT三维重建咽旁隙的研究

目的探索螺旋CT扫描成人呈张口位时咽旁隙成像并行多平面重建和三维重建等后处理，为经口入路切除咽旁隙肿瘤提供解剖依据及术前指导。方法选择咽旁隙无占位性病变患者28例，放置张口器后行多层螺旋CT血管成像，应用多平面重建测量茎突长度并统计茎突末端与第一颈椎横突的关系，于颅底层面测量茎突至颈内动脉、下颌骨升支后缘的距离并进行统计学分析。利用容积重现和剪切技术对图像进行三维重建等后处理，观察颈内动静脉走行及是否存在变异移位等。结果茎突长度、茎突根部至颈内动脉、茎突根部至下颌骨升支后缘的平均距离分别为(2.50±0.80)、(1.09±0.26)、(2.27±0.29)cm，侧别、性别方面均无显著性差异（P＞0.05）。78.6%（44/56）茎突末端位于第一颈椎横突或以下，64.3%（36/56）颈内动脉起始部位低于舌骨，12.5%（7/56）咽旁隙段颈内静脉先走行于颈内动脉前方然后再转向后外。结论咽旁隙以茎突至毗邻解剖结构的距离为参考，有助于神经血管的定位。三维重建的图像能清晰地显示颅底、下颌骨升支、茎突、颈内动静脉等咽旁隙周边及内部结构。咽旁隙段颈内动静脉均存在一定的变异率，为模拟手术入路和术中颈内动脉定位提供重要信息。     

Accuracy of high-resolution computed tomography in locating facial nerve injury sites in temporal bone trauma

In this study, high-resolution, multislice computed tomography findings are compared with surgical findings in terms of the fracture location in patients with traumatic facial paralysis. Patients with traumatic facial paralysis with grade VI House-Brackmann scale who met the criteria for surgical decompression between 2008 and 2012 were included in this study. All the patients underwent a multislice high-resolution, multislice computed tomography (HRCT) using 1-mm-thick slices with a bone window algorithm. The anatomical areas of the temporal bone (including the Fallopian canal) were assessed by CT and during the surgery (separately by the radiologist and the surgeon), and fracture line involvement was recorded. Forty-one patients entered this study. The perigeniculate area was the most commonly involved region (46.34 %) of the facial nerve. The sensitivity and specificity of HRCT to detect a fracture line seems to be different in various sites, but the overall sensitivity and specificity were 77.5 and 77.7 %, respectively. Although HRCT is the modality of choice in traumatic facial paralysis, the diagnostic value may differ according to the fracture location. The results of HRCT should be considered with caution in certain areas.