Lateral skull base surgery for cancer

The management of malignant tumors of the lateral skull base remains a challenging problem. Sixty-two patients underwent lateral skull base resection for cancer. Preoperative evaluation included complete neurotologic examination, CT scan, MRI, and carotid angiography. During surgery, the nasopharynx, the posterior maxilla, the infratemporal fossa structures, the mandibular ramus, and the parotid gland were resected en bloc. Reconstruction of the surgical defect was performed using pectoralis and/or rhombotrapezius myocutaneous flaps. Although the overall cure rate was not greatly improved, patients with lateral skull base malignancies now enjoy extended periods of palliation and a better quality of life.     

Intratemporal carotid artery bypass in resection of a base of skull tumor

Tumors of the skull base with carotid artery involvement have heretofore required carotid ligation or been deemed inoperable. Two case reports are presented in which en bloc resection of malignant base of skull tumors included removal of a portion of the internal carotid artery. In the first case, the tumor was primarily in the parapharyngeal space and extended to the base of skull. Partial temporal bone resection was carried out to obtain exposure for carotid reconstruction. The second case involved an en bloc temporal bone resection for a recurrent, malignant, mixed tumor that had invaded the carotid canal. Revascularization was achieved in both cases by an autogenous, saphenous vein graft. The patients suffered no postoperative ischemic neurologic sequelae. These are the first known cases of a carotid bypass with distal anastomosis to the intratemporal portion of the internal carotid artery for a malignant base of skull neoplasm. The authors propose this procedure as an alternative to carotid ligation during surgery of tumors of the skull base requiring carotid resection.     

Craniofacial resection for malignant tumors of ethmoid and anterior skull base.

A combined craniofacial approach is described for resection of tumors that involve the ethmoid sinuses and adjacent base of the skull in the frontal fossa. This operation provides a more thorough en bloc excision than by conventional methods with reasonable safety since both the neurosurgeon and the head and neck surgeon are guided by each other during the mobilization of the specimen, and adequate repair of dural defects can be accomplished. Reconstruction of the bony defect in the skull base is performed with a pedicled periosteal flap from the scalp and a skin graft.     

Chondrosarcoma of the skull base.

OBJECTIVES: Sarcomas of the skull base are challenging, potentially lethal tumors. Prognosis is considered poor. The present report reviews treatment options and presents a case of treatment with en bloc resection of the temporal bone and adjacent skull base. STUDY DESIGN: Single case report and literature review. RESULTS: Extensive skull base resection for chondrosarcoma can be performed successfully and may be curative. CONCLUSION: There is a role for en bloc resection of large areas of the skull base for treatment of chondrosarcoma. It appears that treatment combining surgery and radiation therapy is most likely to be effective.     

Prognostic factors in oral cavity cancer with skull base recurrence

Objective

Recurred oral cavity cancer at the skull base is complicated to treat due to difficult surgical approach and possible dural invasion. Therefore, initial curative treatment is of most importance and it would be helpful to know cases that would likely recur before treatment. We tried to identify prognostic factors that can predict skull base recurrence after initial treatment, to find out cases that need more aggressive initial treatment.

Methods

This retrospective study was performed on 51 patients diagnosed as squamous cell carcinoma in the oral cavity, and they underwent surgery and adjuvant radiotherapy. Variables associated with clinical findings, imaging studies, and pathologic results were analyzed to identify factors related to skull base recurrence.

Results

Recurrences occurred in 21% (11) cases, and skull base invasion in 5 of these recurred cases. Tumor location, clinical T stage, retromolar trigone (RMT) invasion, bone invasion, perineural invasion, positive resection margin, endolymphatic tumor emboli, and medial and lateral pterygoid muscle invasion were found to be significant prognostic factors by univariate analyses. Among those factors, medial pterygoid muscle invasion and positive resection margin remained independent predictors of skull base recurrence with multivariate analyses by Cox regression.

Conclusion

Patients with medial pterygoid muscle invasion or a positive resection margin have a high risk of skull base invasion during tumor recurrence. Therefore, careful evaluation and aggressive management are needed to prevent skull base invasion in cases that recur.     

Complementary use of computed tomography and magnetic resonance imaging in assessing skull base lesions.

Twenty-six patients underwent computed tomography (CT) and magnetic resonance imaging (MRI) of skull base lesions at the Cleveland Clinic Foundation. CT provided improved bone detail, documenting invasion of the lamina papyracea, orbital floor, fovea ethmoidalis, cribriform plate, pterygoid plates, hard palate, and skull base. MRI defined invasion of the orbit, dura, brain, and cavernous sinus. Improved soft-tissue-tumor interface was evident on MRI. MRI was superior to CT in determining carotid artery involvement. MRI distinguished between tumor and retained secretions in the paranasal sinuses. Combining radiographic tumor staging reliably predicted surgical findings; however, MRI consistently yielded sufficient diagnostic information and the additional expense of performing two imaging procedures may not be justified.     

Management of the carotid artery at the skull base

PURPOSE: To determine appropriate management of benign lesions with significant involvement of the carotid artery at the skull base and present an algorithm for safe treatment of these patients. MATERIALS AND METHODS: From 1982 to 1999, 115 patients with significant parapharyngeal space masses were treated at our institution. Of these patients, 43 had lesions involving the carotid artery at the skull base and served as the basis for this study. All patients underwent preoperative computed tomography or magnetic resonance imaging scans to determine carotid involvement, and all had preoperative 4-vessel arteriograms and carotid occlusion tests with continuous electroencephalography or neurologic examination monitoring to predict safety of carotid sacrifice. RESULTS: Of 43 patients, 41 passed carotid occlusion testing and were treated surgically. Of these patients, 33 (81%) underwent resection of their lesions with preservation of the internal carotid artery, 5 (12%) had resection with bypass or reconstruction of the artery, and 3 (7%) had en bloc resections without artery reconstruction. There were no transient or permanent neurologic sequelae in any patient. CONCLUSIONS: When carotid artery encasement occurs in the setting of benign lesions at the skull base, safe resection with vascular preservation is possible in most cases. If carotid artery resection is necessary, vascular bypass or reconstruction is recommended to minimize neurologic morbidity.     

颅面联合进路切除前颅底肿瘤

目的：探讨累及前颅底或颅内脑组织的鼻腔鼻窦癌的手术切除途径及方法。方法：经颅面联合进路行显微外科连续整块切除累及前颅底或颅内脑组织的鼻腔鼻窦癌15例,其中5例仅累及前颅底,10例累及前颅底至颅内额叶脑组织。硬脑膜缺损应用大腿阔筋膜修补。结果：15例均作了术后随访,随访时间最长为10年,最短2年。其中4例为初治患者,11例为综合治疗后局部复发患者。9例无瘤生存2年以上,2年无瘤生存率为60．00％。11例接受此手术行拯救外科治疗,其中6例无瘤生存2年以上,2年拯救成功率为54．55％。结论：经颅面联合进路行显微外科连续整块切除累及前颅底或颅内脑组织的鼻腔鼻窦癌是可行的。     

Significance of tubal resection in surgical treatment of middle ear carcinoma

We successfully carried out total en bloc resection of squamous cell carcinoma of the middle ear in two patients. Both patients have been free of the disease for 32–39 months. In one of the cases, the eustachian tube was resected totally with the temporal bone. Postoperative histopathological examination proved tumor invasion into the cartilaginous part of the tube. We would like to emphasize the significance of total resection of the eustachian tube when neoplastic invasion into the tube is highly suspected. Axial computed tomography is of great value for preoperative evaluation of such invasion. Anterior mobilization of the carotid artery from the carotid canal facilitates resection of the petrous apex and should be done after management of the eustachian tube. The carotid canal is best exposed ventrally, since lateral exposure is at high risk for injuring the bony part of the eustachian tube and may possibly disseminate tumor cells.     

State of the Art. Diagnostic imaging of paranasal sinus diseases

The following article describes a diagnostic concept of paranasal sinus imaging, based on more than 10 years close collaboration of the authors. CT and MR are the primary imaging modalities for investigating paranasal sinus lesions. Conventional X-ray images add little information due to insufficient sensitivity. Angiography is restricted to those patients who require preoperative tumor embolization or emergency treatment of intractable epistaxis. After thorough medical treatment of inflammatory paranasal sinus disease, CT becomes the method of choice to clearly depict preoperative osseous anatomy and to distinguish between benign and malignant intraosseous lesions. In cases where trauma is involved, CT easily identifies anterior skull base fractures. Moreover, CT will be the first step to localize early or late CSF rhinorrhea. MR, with its ability to distinguish between different soft tissues, compliments CT. This holds particularly true for inflammatory or neoplastic disease close to the skull base, orbital apex and cavernous sinus. The signal intensity in T(1) and T(2) weighted images provides additional information with respect to cellularity and vascularization of lesions, which has important diagnostic and therapeutic implications.     

Endoscopically assisted anterior cranial skull base resection of sinonasal tumors.

The traditional approach to sinonasal tumors involving the base of skull has been the anterior craniofacial resection. Endoscopic techniques have created the potential to approach the intranasal aspect of skull base lesions without external incisions and still develop an en bloc resection when removed. We report our initial experience with skull base neoplasms in which the otolaryngic portion of the standard resection was accomplished instead through an endoscopic approach. The nature of lesions favorable for this approach and associated technical issues are discussed. Although we do not consider this approach a replacement for the traditional anterior craniofacial resection, it is an important adjunct in the skull base surgeon's armamentarium.     

Endoscopic endonasal surgery in the management of selected malignant naso-ethmoidal tumors

Objective

The objective of this study was to report the cases of three patients with sinonasal malignant tumors who underwent en bloc tumor resection using endoscopic endonasal approaches, and to discuss the advantages and limitations of endoscopic endonasal tumor resection.

Methods

Three patients with malignant naso-ethmoidal tumors underwent en bloc resection with endoscopic endonasal approach.

Results

In very carefully selected cases of naso-ethmoidal malignant tumors that were preoperatively evaluated on endoscopic findings and magnetic resonance imaging to be limited to within the nasal cavity and/or ethmoid sinus and to have some safe margins between the tumor and skull base and/or lamina papyracea, tumors were resected en bloc using endoscopic endonasal approaches. A case of cerebrospinal fluid leakage was safely managed with the endoscopic approach.

Conclusions

In selected T1–T2 naso-ethmoidal malignant tumors with some safe margins, endoscopic endonasal surgery may offer a satisfactory alternative to external procedures.     

Ungewöhnliche intra- extrakranielle Ausdehnung eines Meningeoms der lateralen Schädelbasis

Extracranial meningiomas are rare tumors of the lateral skull base. A 37-year-old woman presented with tinnitus und progressive hearing loss of her right ear. A painful mass lesion was also palpable in her mandibular angle. CT and MRI scans revealed an intracranial mass with extension to the lateral skull base. These findings suggested the occurrence of a paraganglioma or meningioma. In a two-stage surgical procedure tumor was extirpated without functional impairment to the patient. Histology of the excised lesion demonstrated an endotheliomatous meningioma. Since an extracranial meningioma can present as a mass lesion of the lateral skull base, CT and MRI scans are essential in preoperative surgical planning.     

Patterns of Framework Invasion in Patients with Laryngeal Cancer: Correlation of in vitro Magnetic Resonance Imaging and Pathological Findings

Total laryngectomy for laryngeal squamous cell carcinoma means a drastic change in the way of living for a patient. New surgical techniques such as laser surgery attempt to save the voice. To be oncologically correct, an accurate assessment of the tumor extent is necessary. Imaging is especially important in determining tumor extent in the regions where conventional and endoscopic ENT examinations are less accurate. Correlations of CT, in vivo MRI and pathological findings after surgery have demonstrated that MRI is more sensitive than CT, but that it overestimates the degree of cartilage invasion. Cartilage invasion is believed to be a contraindication to radiation therapy and voice-sparing surgery. In a prospective study, Gd-enhanced in vitro MRI of 10 total laryngectomy specimens was correlated with subsequent pathological examination. Good correlation of the anatomical relationships of the tumor between the in vitro images and gross pathology were found. Important is the absence of false negatives in our study, indicating that cartilage invasion can be ruled out when a normal signal intensity on in vitro MRI of the cartilage is seen. This has important oncological implications for partial voice-sparing laryngeal surgery.     

Preoperative and intraoperative imaging for endoscopic endonasal approaches to the skull base

Endoscopic endonasal approaches are being used with increasing frequency to provide access to virtually any anterior cranial base, clival, or anterior craniocervical pathology. The radiographic evaluation of skull base anatomy and its relationship to associated tumors is critical for both preoperative planning and intraoperative guidance, to ensure the safety and efficacy of these techniques. CT and MRI play a complementary role in guiding endoscopic endonasal procedures.     

下颌骨外旋咽、颅底肿瘤切除术4例报告

目的总结下颌骨外旋咽、颅底肿瘤切除术的体会.方法 4例咽及颅底肿瘤均采用下颌骨外旋入路进行手术切除.同期颈淋巴结清扫术2例,咽侧壁缺损以咽后壁局部黏膜转移修复2例.结果 3例恶性肿瘤完全切除;1例脊索瘤未完全切除,术后发生脑脊液鼻漏,填塞后痊愈.2例口咽癌中,1例术后1年死于局部复发,另1例术后2年10个月死于肺部转移.1例咽旁恶性混合瘤已术后3年2个月,仍在随访中.1例脊索瘤2年5个月死于颅内广泛转移.结论此手术入路能充分显露咽、中颅底、咽旁间隙、斜坡和颈椎,并能从颈部向上至颅底,将肿瘤完全切除,手术安全,后遗症轻微.     

颅底脊索瘤的CT和核磁共振成像影像分析

目的研究颅底脊索瘤的CT、核磁共振(magneticresonanceimaging,MRI)诊断特征和临床应用价值.方法16例颅底脊索瘤和侵犯颅底的13例鼻咽癌、11例垂体瘤患者作了头颅CT、MRI检查;7例颅底脊索瘤作了MRI的多层面重建(multipleplanarreconstruction,MPR).结果MRI反映肿瘤的部位和侵犯范围优于CT,CT、MRI显示颅底中线骨质破坏作用相似.根据MRI显示肿瘤的部位与侵犯范围,颅底脊索瘤分为蝶鞍斜坡型、鼻咽型和颞枕型.颅底脊索瘤T2加权(T2weightimaging,T2WI)信号强度明显高于侵犯颅底的鼻咽癌和垂体瘤(P＜0.01).MRI的MPR影像显示,3例视神经被肿瘤推压移位,4例被肿瘤包埋,7例功能损害的外展神经均为肿瘤包绕侵蚀,3例动眼神经受压.结论T2WI显著高信号是颅底脊索瘤的特征性MRI征象,有重要鉴别意义;MRI的MPR技术可对颅神经精确显示,在颅底脊索瘤的手术中有重要应用价值.     

CT and MRI and clinical study of chordoma in the skull base]

OBJECTIVE: To investigate the diagnostic features of CT and MRI in chordoma of the skull base (CSB) and to estimate their value of clinical application. METHODS: Sixteen patients with CSB were performed CT and MRI examinations of the head, and 13 patients with nasopharyngeal carcinoma (NPC) and 11 patients with pituitary adenoma (PA) which invaded the skull base were selected as control. In addition, 7 cases of chordoma were performed multiple planar reconstruction (MPR) of MRI. RESULTS: MRI was superior to CT in depicting the location and the extent of CSB. The bone destruction at mid-line skull base was demonstrated equally well on both CT and MRI. Based on the location of the tumor displayed on MRI, the CSB could be classified into selloclival, nasopharyngeal, and occipito-temperal types. The T2 weight imaging(T2WI) signal intensity of chordoma was significantly higher than those of NPC and PA (P < 0.01). On MPR images of MRI, oppressed and displaced optic nerves caused by chordoma were noted in 3 cases and encased optic nerves in 4 cases, encased abducent nerves in 7 cases with abducent paralysis and mildly oppressed oculomotor nerves in 3 cases. CONCLUSION: The extremely high T2WI signal intensity is the characteristic of MRI finding in CSB and has great differential value for the tumors of the skull base. The MPR of MRI plays an important role in the surgical treatment for these tumors.     

Prognostic factors in craniofacial surgery

From 1979 to 1989, 21 patients underwent craniofacial resection for malignancies involving the anterior skull base. Histologic types included 8 squamous cell carcinomas, 3 chondrosarcomas, 2 melanomas, 2 basal cell carcinomas, 2 adenocarcinomas, 2 poorly differentiated carcinomas, 1 malignant schwannoma, and 1 malignant hemangiopericytoma. Survival was 57%, with follow-up of 41 months. A 50% complication rate included osteomyelitis, cerebrospinal fluid rhinorrhea, meningitis, brain abscess, epidural abscess, and syndrome of inappropriate antidiuretic hormone. Recurrent disease occurred in 9 patients (41%), the most reliable predictor being dural invasion indicated preoperatively by CT scan or at operation. Patients demonstrating dural involvement (N = 9) had a 22% survival rate, while patients without (N = 12) had a survival rate of 83%. The impact of dural invasion on long-term survival is emphasized. Though complications were frequent, long-term results were favorable.     

Indications and diagnostic sensitivity of CT and MRI in the otorhinolaryngology field

Of all malignant tumors, 4-5% affect the head and neck region. Computed tomography (CT) and magnetic resonance imaging (MRI) provide the means for us to determine the precise extent and depth of infiltration of space-occupying lesions, detect submucosal growth, stage lymph nodes preoperatively, and thus facilitate better preoperative planning. Thinner collimations of sections and shorter examination times are possible with modern multilayer spiral CT. Two-dimensional and three-dimensional images can be calculated from the volume specifications to assess the skull base (coronal and sagittal sections) and the midline crossover of tumors as well as staging of lymph nodes (coronal section). Examination of laryngeal and hypopharyngeal function as well as determination of tumor perfusion are also possible. Detection of tumors that do not absorb any contrast medium (approximately 15%) is more difficult with CT. In addition to providing a high degree of tissue contrast, MRI makes it possible to directly acquire images in any number of planes. In contrast to CT, metallic artefacts hardly come into play. Infiltration of the dura and the cerebrum can be depicted better with MRI than with CT. The long examination time with MRI carries the risk of movement artefacts. In the head and neck region, it is important to suppress fat in T2-weighted sequences and in T1-weighted sequences after administration of contrast media. Inflammations in the head and neck region are only exceptionally clarified with CT or MRI. It is imperative that CT be performed before functional endoscopic operations of the paranasal sinuses. Further indications for CT and MRI in cases of inflammation are the diagnosis of retrotonsillar and parapharyngeal abscesses and ensuing complications as well as the diagnosis of osteomyelitis. Since conventional sialography is contraindicated in acute inflammation in sialolithiasis, magnetic resonance sialography can be employed.