Skull base chordomas

Skull base chordomas are rare midline malignancies of clival origin that represent one of the most challenging skull base tumors to treat, given their location, invasiveness, potential extension around vital neurovascular structures, and high recurrence rate. Total tumor resection is the mainstay of treatment. The combination of surgery and postoperative irradiation appears to provide the best outcome.     

Skull base chordomas

Chordomas are rare, benign tumors of the nasopharynx. Because of their location at the skull base, removal of these tumors is usually subtotal. Described is the transcervical-transmandibular approach to the skull base which can be employed in removing these tumors.     

Skull base mapping

Early experience with medium to large tumors of the temporal region has re-emphasized the value of radiologic preoperative plotting of these space occupying lesions in the sagittal, coronal, and horizontal planes. Attention to probable pathology, neurovascular structures and patient's medical status has been important in determining resectability. A standard format of the interior and exterior of the skull base and cervical spine has been employed to map these lesions. Such devices have been used by otolaryngologists in the past to depict laryngeal lesions; and provide for the skull base surgeon a common base of comparison of tumor size, chart documentation, and a means to facilitate communication among other specialists. Experience with 36 cases of skull base tumors seen since July 1979 has emphasized the occult manner in which these lesions may present.     

Skull base surgery

Surgical inaccessibility, the obstacles of vital neural and vascular anatomy, and the overwhelming surgical mortality rate as a result of hemorrhage and sepsis have led surgeons to approach lesions of the skull base with understandable reluctance. We have, however, undergone a technical revolution in microsurgery, anesthesia, and neurodiagnosis. Innovative surgical minds have thus been armed with the technology to make surgery a reasonable alternative for these dreaded lesions. This article singles out the glomus tumor and its associated lesions, which the neuro-otologist must approach transtemporally. Their diagnosis and new treatment concepts are discussed. Old criteria for unresectability are redefined and new classifications are established. Surgery of these skull base lesions is discussed from the standpoint of the basic principles of exposure, hemostasis, and management of the facial nerve. Problems in rehabilitation of postoperative deficits are discussed.     

Skull base reconstruction

Reconstruction of skull base defects following tumor resection is of paramount importance in avoiding serious and life-threatening complications. Cranial base surgery has evolved and outcomes have steadily improved as increasingly reliable reconstructive techniques have been adapted to repair the challenging wounds in this complex anatomic region. The most significant development has been the introduction and refinement of microvascular free tissue transfer to the skull base over the past 15 to 20 years. Free flaps can reliably provide the requisite tissue to not only seal the intracranial space from the subjacent cavities, but also to restore complex craniofacial defects that often result from skull base tumor excision. Advances in alloplast technology have also expanded the armamentarium available to the reconstructive surgeon. In particular, bone substitutes, titanium hardware, and resorbable plate fixation have been shown to be very efficacious when used in carefully selected situations. Finally, tissue sealants and adhesives have become widely used as an adjunctive method to achieve a water-tight dural repair.     

颅底临床解剖标志与颅底肿瘤手术的安全性

目的　探讨颅底手术的重要解剖标志 ,保证颅底手术的安全性并彻底根治肿瘤。方法对我院 10年来 2 9例不同颅底手术进行回顾性总结 ,分析颅底的鸡冠、翼突和颞骨棘、茎突和颈内动脉及其各自的毗邻解剖结构在术前诊断、不同手术进路切除肿瘤时的应用情况。结果　本组初期3例手术中有 2例术后颅底有部分肿瘤残留 ;其余 2 6例颅底手术中 ,皆在直视下完全切除肿瘤 ,无手术死亡及严重颅脑并发症。本组 2 9例中 ,侵犯颅底的恶性肿瘤行不同的颅底手术 19例 ,其 3年生存率为 72 2 % (13/ 18) ,5年生存率为 35 7% (5 / 14 )。结论　鸡冠、翼突和颞骨棘、茎突和颈内动脉及其各自的毗邻解剖结构分别是不同的颅底手术重要标志 ,正确认识这些临床解剖标志是颅底手术安全成功的保证     

Extracranial skull base chondrosarcoma

Chondrosarcoma of the skull base is a rare neoplasm. The most common presenting symptoms are hoarseness, dysphagia, and diplopia, which is associated with palsies of cranial nerves X, IX, and VI. The temporal bone is the most common site of tumor origin, followed by the sphenoid bone. These tumors must be differentiated from chordoma, chondroid chordoma, osteogenic sarcoma, enchondroma, and meningioma. Diagnosis is made by patient history, radiologic imaging, and biopsy. The treatment is surgical excision followed by radiation therapy. Five-year survival rates for grades I, II, and III are 90, 81, and 43%, respectively.     

Nasal base surgery.

Nasal base surgery is a challenging and yet rewarding part of rhinoplasty. The nasal base, the most frequently ignored view of the nose, provides important information with regards to projection, lobular anatomy, nostril size, and overall aesthetics of the nose. This article reviews the anatomy of the nasal base and its surrounding structures, as well as aesthetically pleasing proportions of the nasal base in context of facial analysis. Specific criteria for evaluating discrepancies of the alar-columellar relationship also are described, as well as aesthetic rhinoplastic techniques to correct them.     

Contemporary skull base reconstruction

PURPOSE OF REVIEW: Tumors of the skull base that would have been considered inoperable thirty or forty years ago are now routinely resected with reliable results due to the advancement of modern reconstructive techniques. High mortality rates were common prior to the use of vascularized tissue for skull base repair. However, the advent of local flap reconstruction for skull base defects in the 1960s revolutionized skull base surgery. The use of regional flaps in the 1970s and 1980s allowed skull base surgeons to perform more extensive surgeries, but complication rates were still quite high. RECENT FINDINGS: Experience with free tissue reconstruction increased through the 1980s and 1990s and has become a reliable method to separate the intracranial from extracranial environments. Free tissue transfer has allowed surgeons to address the large volume defects created by extensive skull base resections and has provided dependable, vascularized tissue that is relatively resistant to adjuvant radiation. Local flaps have also become a powerful reconstructive tool in conjunction with free tissue transfer, and in some select cases, may be sufficient alone for reconstruction. SUMMARY: The prevention of serious complications after skull surgery has improved with the use of vascularized tissue. Depending on the anatomic site, the extent of the defect, and the quality of local tissues, either free tissue transfer and/or local flap reconstruction is preferred. Regional flap reconstruction should be reserved for cases where alternative reconstructive techniques are not available.     

Anterior skull base surgery

This article focuses on selected key anatomic considerations in anterior skull base surgery, briefly reviews common pathologies of the paranasal sinuses, and provides an overview of surgical approaches, complications, and results.     

内镜下65例鼻颅底肿瘤切除后颅底重建临床分析

目的 探讨鼻内镜下鼻颅底肿瘤切除后采用游离中鼻甲黏膜（FMT）、阔筋膜、鼻中隔带蒂黏膜瓣（HBF）行颅底缺损重建治疗脑脊液鼻漏的临床效果。方法 回顾性分析65例在鼻内镜下行鼻颅底肿瘤切除且行颅底重建治疗脑脊液鼻漏患者的病例资料。根据颅底缺损大小及部位选择修补材料,缺损<1.5 cm,均采用FMT（24例）;缺损≥ 1.5 cm,优先选择HBF（16例）,但当HBF无法获取或不适用（缺损位于额窦后壁）,选择阔筋膜（25例）。分析患者的修补效果并比较阔筋膜与HBF的修补结果。结果 采用FMT行颅底缺损重建治疗的患者有2例出现术后脑脊液漏,一次性修补成功率为91.7%;采用阔筋膜治疗的患者有1例出现术后脑脊液漏,一次性修补成功率为96%;采用HBF治疗的患者有1例出现术后脑脊液漏,一次性修补成功率为93.8%;总体成功率93.8%。采用阔筋膜行颅底修补的患者术后出现颅内感染2例、肺部感染0例、术后鼻出血2例,采用HBF行颅底修补的患者术后出现颅内感染1例、肺部感染2例、术后鼻出血2例,两种颅底修补方法术后并发症均无明显差异。结论 鼻内镜下采用HBF、阔筋膜或FMT行颅底重建治疗脑脊液鼻漏均可获得较为满意的结果。FMT对于较小（<1.5 cm）的缺损是可靠的修补材料;对于较大的缺损（≥ 1.5 cm）,HBF或阔筋膜均可以采用且获得相似的结果,当HBF无法获取或不适用（缺损位于额窦后壁）,选择阔筋膜是可行的。     

颅底临床解剖标志与颅底肿瘤手术的安全性

目的 探讨颅底手术的重要解剖标志，保证颅底手术的安全性并彻底根治肿瘤。方法 对我院10年来29例不同颅底手术进行回顾性总结，分析颅底的鸡冠、翼突和颞骨棘、茎突和颈内动脉及其各自的毗邻解剖结构在术前诊断、不同手术进路切除肿瘤时的应用情况。结果 本组初期3例手术中有2例术后颅底有部分肿瘤残留；其余26例颅底手术中，皆在直视下完全切除肿瘤，无手术死亡及严重颅脑并发症。本组29例中，侵犯颅底的恶性肿瘤行不同的颅底手术19例，其3年生存率为72．2％(13／18)，5年生存率为35．7％(5／14)。结论 鸡冠、翼突和颞骨棘、茎突和颈内动脉及其各自的毗邻解剖结构分别是不同的颅底手术重要标志，正确认识这些临床解剖标志是颅底手术安全成功的保证。     

Reconstruction of the skull base

Tumor surgery of the skull base has been increasingly undertaken in recent years. This report involves a series of 18 consecutive patients who have undergone 22 operations at Ohio State University from July 1980 to January 1983 for removal of tumors either adjacent to or through the skull base. A variety of reconstructive techniques such as pericranial flaps, muscle flaps, temporalis fascial grafts, split-rib grafts, fat grafts, and bone grafts have been found to be reliable. This series also included the successful use of a temporalis myocutaneous flap. The conclusion of this study is that these techniques provide a safe approach to the resection of tumors involving the base of skull.     

Advances in skull base imaging

Despite being introduced in the 1970s and 1980s, CT and MRI continue to be the primary imaging modalities for the temporal bone and skull base. Although the general concepts and physics remain the same, the images obtained currently are far superior. Augmenting these traditional modalities are nuclear medicine imaging techniques, functional imaging, and the fusion of different techniques. Advances in these areas are expanding our options and illuminating pathology in unique ways. As basic physiologic processes are better understood, new opportunities for novel imaging techniques should arise.     

鼻内镜下可用的带血管蒂组织瓣文献综述

鼻内镜颅底外科术后隔绝颅腔与鼻腔的交通是该学科发展面对的挑战之一,近年利用带血管蒂组织瓣,经内镜手术入路修复颅底缺损获得满意疗效。颅底局部性和区域性带血管蒂组织瓣,修复范围广泛、取材方便、抗感染性强、易于成活,是修复颅底缺损的最佳选择。本文对内镜下修复颅底常用带血管蒂组织瓣进行综述。     

Possible anatomical base of snoring

Variations of the medial and inferior choanal limits may facilitate snoring. These are: 1) short vomer without crista choanalis vomeris and adaptational formations, 2) extremely concave posterior margin of the hard palate leading to disproportion between the muscular and aponeurotic part of m. tensor veli palatini and hence to a flabby soft palate especially during sleep, and 3) neonatal relation of the height and width of the choane resulting in a very large choanal region instead of relative reduction of choanal width compared to its increasing height. All these variations result in a flabby soft palate especially during sleep and may lead to formation of whirles of inspired air and snoring.