Schwannoma of the skull base with intracranial extension

A case is reported of solitary schwannoma involving the skull base with extension into the middle cranial fossa and parasellar region. The patient presented with an exophthalmos and ipsilateral facial numbness. The tumor was successfully excised via a two-stage procedure involving an initial intracranial and subsequent transmaxillary approach. The relevant literature on the presentation and treatment of schwannomas of the skull base with intracranial extension is also reviewed.     

Internal carotid artery sacrifice for radical resection of skull base tumors

When dealing with skull base tumors that encase the internal carotid artery (ICA), the surgeon must decide between ICA preservation and incomplete tumor resection, or radical resection with ICA sacrifice. In our experience with more than 300 anterior skull base tumors, the ICA was sacrificed in only 10 patients. These tumors were malignant, except for one meningioma that occluded the ICA and produced translent ischemic symptoms. All patients had the ICA resected with the tumor, and all patients underwent revascularization (cervical ICA-MCA saphenous bypass, n = 4; cervical-to-supraclinoid bypass, n = 1; petrous-to-supraclinoid bypass, n = 3; bonnet bypass, n = 2). This small patient series reflects our practice of preserving the ICA whenever possible. We recommend preserving the ICA with benign tumors because they do not invade the artery, or do so only to a limited extent. In addition, similar rates of tumor recurrence are seen after aggressive resection with or without ICA sacrifice. In contrast, we recommend radical tumor resection and sacrifice of the ICA with malignant tumors because they directly threaten the integrity of the ICA and the patient's survival. The ICA should not be considered a limitation to radical tumor resection because the ICA can be reconstructed safely with an appropriate bypass procedure.     

颈动脉体瘤的外科治疗

目的 总结颈动脉体瘤的外科治疗经验.方法 从1994年起共手术治疗颈动脉体瘤54例,其中男39例,女15例,男女比例为2.6:1.发病年龄22～53岁,平均年龄31岁.所有瘤体均为良性和单侧发病.手术方法包括:单纯颈动脉体瘤瘤体切除12例;瘤体加颈外动脉切除5例;颈动脉体瘤切除加颈内动脉血管重建6例(其中4例应用大隐静脉,2例应用直径6 mm的PTFE人工血管);借助颈动脉内转流切除瘤体32例(包括3例颈内动脉重建者);因瘤体位置太高需打断下颌骨切除瘤体者2例.结果 54例瘤体均完全切除,无复发,无转移病例.无1例发生脑缺血并发症.颈部神经损伤7例,其中交感神经和喉上神经损伤各2例,喉返神经损伤3例.结论 颈动脉转流管有助于颈动脉体瘤切除,需切除颈内动脉者应予以重建,瘤体位置过高者打断下颌骨可增加显露.     

Recent advances in the treatment of skull base tumors using radiation

The evolution of technology has led to dramatic advances in the ability to treat tumors of the skull base, and the future of these devices seems bright. Only with time, however, will we be certain of their true role in the management of tumors of the skull base.     

颈动脉体瘤的外科治疗

目的 探讨颈动脉体瘤的诊断与外科治疗.方法 分析山东大学附属省立医院血管外科2003年1月至2010年10月收治16例颈动脉体瘤患者,经数字减影血管造影术检查得以最终确诊.采用Shamblin分型标准分型:Ⅰ型3例,Ⅱ型11例,Ⅲ型2例,本组全部行外科手术治疗.3例ⅠⅠ型患者行单纯摘除术.11例Ⅱ型患者中,3例行单纯摘除术,3例行摘除术并颈外动脉切除,3例行摘除术、颈外动脉切除并颈动脉修补术,2例行摘除术、颈外动脉切除并颈内动脉重建术.2例Ⅲ型患者,1例行摘除术、颈外动脉切除并颈动脉修补术,1例行摘除术、颈外动脉切除并颈内动脉重建术.结果 16例患者病理均证实为颈动脉体瘤.无手术死亡、偏瘫和失明.术后并发症中以颅神经损伤最多见,共有7例(43.75%),经对症治疗,6例有不同程度改善,1例遗留永久性13角歪斜.随访13例(81.25%),随访时间2～76个月,平均(42.0±1.2)个月,未见肿瘤复发和远处转移.结论 数字减影血管造影术在颈动脉体瘤的诊断和治疗中具有重要意义,颈动脉体瘤应首选手术治疗,可根据瘤体与血管的关系选择适当的术式.

Abstract：

Objective To discuss the diagnosis and surgical treatment for carotid body tumors (CBT). Methods Retrospective analysis was made on 16 cases of carotid body tumors hospitalized in Shandong Provincal Hospital from January 2003 to October 2010. All patients were diagnosed by digital subtraction angiography, including 3 case of Shamblin type Ⅰ,11 cases of Shamblin type Ⅱ and 2 cases of Shamblin type Ⅲ. Three cases of type Ⅰ and 3 cases of type Ⅱ underwent carotid body tumor resection. Three cases of type Ⅱ underwent carotid body tumor plus external carotid artery resection, 3 cases underwent carotid body tumor plus external carotid artery resection plus carotid artery repairment, 2 cases did carotid body tumor plus external carotid artery resection plus internal carotid artery reconstruction. One of type Ⅲ underwent carotid body tumor plus external carotid artery resection plus carotid artery repairment, and the other one underwent carotid body tumor plus external carotid artery resection plus internal carotid artery reconstruction. Results Diagnosis of CBT was confirmed by pathology in all cases. There was no postoperative death、hemiplegia and blindness. The cranial nerve injury was caused in 7 cases, accounting for 43. 75%. 13 cases ( 81. 25% ) were followed up for 2 to 76 months ( mean 42 months), no tumor recurrence and metastasis was found. Conclusions Digital subtraction angiography (DSA) is important in the diagnosis and therapy of carotid body tumor. Surgical treatment is the choice of therapy for carotid body tumors.     

Surgical treatment of tumors of the carotid body

In the period between 1967 and 1985 the authors operated on 5 patients with chemodectoma; their ages ranged from 29 to 39. The duration of the disease ranged from 2 to 4 years. The tumor was on the right side in 3 and on the left side in 2 patients. Carotid angiography, which was conducted in all cases, revealed a richly vascularized tumor in the region of the carotid artery bifurcation with characteristic "angulation" and "cuff" signs. Damage to the carotid arteries was avoided during the operation in 3 patients and the chemodectoma was removed subadventitionally. In 2 patients the arteries were injured. There were neither neurological complications nor fatal outcomes.     

Vertical Ramus osteotomy allows exposure of the distal internal carotid artery to the base of the skull

Exposure of the distal internal carotid artery (ICA) above the level of the second cervical vertebra can be difficult and often require maneuvers such as division of the digastric muscle or mandibular subluxation. These techniques increase exposure but may not provide adequate access. We report a series of eight cases in which vertical division of the mandibular ramus provided access of the ICA up to the base of the skull. Over the last 10 years, eight patients underwent vertical ramus osteotomy (VRO) to aid in distal ICA exposure. Preoperative arteriography revealed ICA lesions within 1.5 cm of the skull base. Indications for surgery were compelling and included gunshot wounds to zone III of the neck (n = 2), transient ischemic attack (n = 2), and preocclusive stenosis (n = 4). VRO was performed through a standard vertical neck incision and was created from the depth of the sigmoid notch to the angle of the mandible after elevating the masseter muscle from the bone. Miniature titanium plates were used to reapproximate the mandible after endarterectomy (n = 5), bypass (n = 2), or arterial repair (n = 1). We found that VRO provides reliable exposure of the distal ICA up to the base of the skull. Unlike mandibular subluxation, it requires no pre-incision preparation, thus mandibulotomy can be performed after carotid artery dissection has begun, and may even be avoided. VRO is especially useful when carotid artery pathology unexpectedly extends beyond the usual field of exposure. Work on the carotid artery at the skull base is associated with significant complications and should be reserved for compelling indications. Presented at the Twenty-fifth Annual Meeting of the Peripheral Vascular Surgery Society, Toronto, Ontario, Canada, June 10, 2000.     

双侧颈动脉体瘤的手术治疗

目的 探讨双侧颈动脉体瘤的手术治疗.方法 回顾性分析北京大学人民医院1994年以来收治的5例双侧颈动脉体瘤患者的临床资料.男1例,女4例,2例女性为姐妹,年龄26～48岁,平均(37±10)岁.5例患者均表现为双侧颈部无痛性肿物,术前行喉镜检查了解声带活动情况,双侧肿瘤均分次切除,先切除肿瘤体积较小一侧.2例Shamblin Ⅰ型和2例ShamblinⅡ型行单纯肿瘤切除;3例ShamblinⅡ型行肿瘤加颈外动脉切除;3例ShamblinⅢ型切除肿瘤并行颈内动脉重建,2例应用自体大隐静脉,1例应用直径6 mm人工血管,动脉重建过程中使用转流管保持颈内动脉血供.结果 5例患者双侧肿瘤均完整切除,病理证实为良性颈动脉体瘤,无肿瘤残留者,未发生脑缺血并发症,未出现颈部血肿,未出现压力感受器调节失效综合征,2例术后出现颅神经损伤.随访时间6～39个月,平均(25±13)个月,未发现肿瘤复发和转移,3例颈内动脉重建者未发现颈动脉血栓形成.结论 双侧颈动脉体瘤分次手术切除是安全的,颈动脉转流管有助于术中肿瘤切除.     

Plexiform ameloblastoma of the maxilla with extension to the skull base

Ameloblastomas are locally invasive benign tumors believed to originate from the developing dental lamina. Maxillary ameloblastomas are rare, comprising only 20% of all ameloblastomas. Of these, 90% arise posterior to the canine tooth. As tumors of the posterior maxilla grow slowly, symptoms are few until the tumor has reached considerable size. At the time of presentation there may be evidence of extension into anatomic areas adjacent to the posterior maxilla. Hemimaxillectomy through wide surgical exposure has the best chance of achieving tumor control. However, once the tumor has extended beyond the confines of the maxilla the prognosis for control of the disease is poor.     

Neuronavigation in skull base tumors.

OBJECTIVE: Computer-assisted neuronavigation was used in 87 cases of skull base lesions (SBLs). Preoperative planning and intraoperative identification of anatomic landmarks is especially important in SBLs since it helps to avoid or minimize surgical morbidity and mortality. In this study, we assessed the accuracy and the clinical usefulness of a frameless system based on the optical digitizer in SBLs. PATIENTS AND METHODS: Between April 2000 and March 2003, eighty-seven patients with SBLs were operated on in our department using cranial neuronavigation. A passive-marker-based neuronavigation system was used for intraoperative image guidance. There were 56 women and 31 men. The patient's ages ranged from 4 to 76 years (average: 45.7 year). The locations of the tumors reported in this series were as follows: frontobasal, 24 cases; sellar/parasellar, 32 cases; petroclival, 16 cases; tentorial/subtemporal, 15 cases. RESULTS: The computer-calculated registration accuracy ranged between 0.3 and 1.7 mm (mean, 1.1 mm). Gross total removal of the SBLs was accomplished in 82 out of 87 patients as was confirmed on postoperative CT and MRI scans. The follow-up period ranged from 1 month to 48 months (average: 20.1 months). Overall mortality and severe morbidity (meningitis, permanent cranial nerve deficits, and cerebrospinal fluid fistulae) rates were 4.6 % and 33.3 %, respectively. CONCLUSION: The image-guided surgery is a valuable aid for safe, helpful and complete removal of SBLs of the brain where accurate localization of the lesion is critical. Although our preliminary series is not large, interactive image guidance provides a constant display of surgical instrument position during surgery and its relationship with the SBLs components, surrounding normal brain, and vascular structures, providing valuable guidance to the surgeon during an operation. Our experience with the neuronavigation suggests that image guidance is helpful in this type of lesions, providing better anatomic orientation during skull base surgery, delineating tumor margins and their relation to critical neurovascular structures.     

Surgical treatment of tumors in the anterior skull base using the transbasal approach

Five patients with tumors in the anterior skull base were surgically treated using the transbasal approach, which permits removal of the tumor, repair of the dura mater, and reconstruction of the skull base in a one-stage procedure. By using autologous materials for the bone graft and pedunculated pericranial flap for the reconstruction, the intracranial structures are separated from the air-filled nasal and paranasal cavities. No postoperative complications such as wound infection and leakage of cerebrospinal fluid were encountered. The use of this surgical technique makes it possible to extirpate brain tumors that heretofore have been considered unresectable.     

Malignant tumors of the anterior cranial skull base

Malignant tumors of the anterior cranial skull base are still a challenge for radical surgical treatment. Several different techniques and approaches have been developed over the years and the results, with mortality rates over 50%, are still not encouraging.Here we present our results of an interdisciplinary, onestage, neurohino transfronto-transbasal surgical approach in twelve patients with such tumors.The long-term survival rate in our patients is now 83% with a mean postoperative follow-up of 19.3 months. Two patients died due to early recurrencies and metastasis after 10 and 13 months after initial treatment and postoperative irradiation.Another five patients with a follow-up of 34.2 months have had tumor recurrencies diagnosed at 19.5 months postoperatively. These patients have survived their recurrent tumor for 14.7 months.Five patients, 41% of the whole group, have been living without evidence of tumor recurrence for between 2 and 35 months.     

Trigeminal nerve tumors of the lateral skull base

A retrospective review of 8 trigeminal nerve tumors centered in the lateral skull base was carried out. Clinical manifestations, radiographic features, and outcome of management are detailed. Six patients in this series presented for primary surgery, and 2 patients had prior surgical interventions with incomplete resections.Surgical exposure via the infratemporal fossa (ITF) approaches resulted in complete tumor extirpation in all but I of the reoperated cases. Limited postoperative cranial neuropathies and the lack of intracranial complications are particularly notable in this series.A mean follow-up of 3 years revealed no evidence of recurrent disease. In the case of incomplete resection, there appears to be no appreciable growth of the small tumor remnant in the region of the cavernous sinus after 5 years.Trigeminal tumors of the lateral skull base with intracranial components below the level of the posterior clinoid process are ideally suited for the ITF techniques. The importance of securing the petrous carotid artery through a wide exposure is emphasized.     

Progress in carotid artery surgery at the base of the skull

From 1977 to 1984, 752 reconstructions of the supra-aortic arteries were performed at our service. In a group of 31 patients presenting with transient ischemic attacks (13) or minor strokes (15), preoperative multiplane angiograms identified lesions from various causes in extremely high locations (fibromuscular dysplasia, 10; atherosclerosis, 6; traumatic changes, 10; spontaneous dissection, 3; and mycotic aneurysms and others, 4) in 34 internal carotid arteries (aneurysms, 10; and stenosis, 24). Surgery was performed on 30 patients. Flow restoration was achieved by resection and vein graft replacement (20), gradual dilatation (5), thromboendarterectomy (6), and tangential clip for exclusion of a lateral aneurysm (1). Only one patient was treated with an extracranial-intracranial anastomosis because the stenosis extended into the carotid siphon. One patient was treated with heparin. Exposure of the internal carotid artery (ICA) at the base of the skull required dissection of the digastric muscle, careful mobilization of the cranial nerves, and detachment of the styloid process in 29 patients. Partial resection of the mastoid process was helpful in two patients. The carotid bone canal was opened from the lateral side in four cases to allow the most distal anastomosis 1 cm within the carotid canal. Back-bleeding was controlled by a balloon catheter. A shunt was impossible to use and clamping time averaged 62 ± 40 minutes. Except for one recurrent stroke and two transient ischemic attacks no other neurologic deficits occurred. Cranial nerve damage could not be avoided in 21 cases (nervus recurrens, 7; nervus glossopharyngeus, 16; and nervus facialis, 4) but disappeared clinically within a 1- to 6-month period in all but two. Each surgical patient underwent control angiography, which demonstrated 30 arteries to be patent, two became occluded, and one had an insignificant stenosis. We conclude that standard surgical techniques are unsuitable for repair of highly located lesions of the ICA. Although extracranial-intracranial anastomosis has been proposed in patients with planned ligation of the ICA, the anatomic reconstruction remains advantageous because flow is restored to normal and the source of emboli is eliminated. With the use of a special approach, graft replacement can be performed up to the base of the skull. (J VASC SURG 1984;1:734-743.)     

颈动脉体瘤的手术治疗及围手术期处理

目的探讨颈动脉体瘤手术及围手术期处理方法。方法 15例颈动脉体瘤患者均给予充分的围手术期处理后行手术治疗。结果 15例中6例行单纯肿瘤剥离切除,7列行肿瘤及颈外动脉切除,2例行肿瘤及颈总动脉交叉处切除,颈总与颈内动脉重建。手术顺利,无手术死亡者。术后随访1～3年,平均15.3个月,所有患者手术切口一期愈合,肿瘤压迫症状消失,其中2例术后头痛3个月,经对症处理后头痛好转,1例术后2d天出现脑梗死,1例出现舌下神经损伤,经治疗后症状缓解。术后肿瘤无复发。结论完善的围手术期处理可提高颈动脉体瘤切除手术的疗效、增加手术的安全性、降低手术的并发症。