Prevention of CSF Leakage by Staged Operation for Clival Metastatic Tumor

The transoral approach is a direct route to the clivus. However, application of this approach is infrequent because of the risk of cerebrospinal fluid (CSF) fistula and subsequent meningitis. We report a case of clival metastatic tumor treated by staged operation without CSF leakage. A 39-year-old man was found to have a tumor in clivus extending to the intradural space. Two-staged resection through the lateral suboccipital and transoral approach was performed and the dural defect was replaced by a fascia in the first operation. CSF leakage was prevented by this procedure. The patient received radiotherapy postoperatively.     

Transoral transclival approach for intradural lesions using a protective bone baffle to block cerebrospinal fluid pulse energy--two case reports

The transoral transclival approach for the treatment of intradural lesions of the clivus is often associated with serious complications such as cerebrospinal fluid (CSF) leakage and meningitis. CSF pulse energy may be the most significant factor in CSF leakage and meningitis, but a bone baffle can block such CSF pulse energy. A 64-year-old female presented with sudden onset of severe headache. She had subarachnoidal hemorrhage due to a rupture of the vertebral-posterior inferior cerebellar artery aneurysm. A 66-year-old female complaining of occipitalgia and numbness of the extremities had a foramen magnum meningioma. Both patients were treated via the transoral transclival route with a protective bone baffle, obtained from the iliac bone, securely fixed in the bone window to protect the repaired dura from injury by CSF pulse energy. Neither patient showed CSF leakage or meningitis, and the period of continuous lumbar CSF drainage was only 7 days. The transoral transclival approach with a bone baffle is still very effective in selected cases.     

经口咽入路显微外科技术治疗颅颈区畸型

目的　总结经口咽入路颅颈区畸型的显微外科治疗的体会。　方法　分析 16例颅颈区畸型的围手术期处理包括抗生素应用、气管切开、静脉营养、颅骨牵引等及手术方法、术后并发症的处理、手术结果等。　结果　本组 16例颅颈区畸型 ,以颅底陷入为主的枕骨大孔区畸型 8例 ,慢性寰枢椎脱位 3例 ,齿状突骨折及脱位 2例 ,下斜坡脊索瘤 2例 ,颈髓腹侧肉芽肿 1例。其中 3例行二期植骨。随访半年～ 3年。 10例恢复轻体力劳动 ,4例生活自理 ,1例临床症状改善 ,1例死亡。　结论　采用显微外科技术经口咽入路治疗颅颈区前方病变可降低术后并发症和致残率。重视围手术期处理 ,预防术后伤口感染和脑脊液漏。二期植骨能增加颈椎稳定性。     

Transcervical and transoral approach to clival and upper cervical chordoma: a case report

The patient, a 48-year-old man, was first admitted in 1981 for the chief complaints of retropharyngeal tumor and anosmia. Computerized tomography scan disclosed destruction of the lower half of the clivus and retropharyngeal tumor predominantly located in the third prevertebral region. The tumor was removed partially via the transcervical approach and was histologically a typical chordoma. Two years later the tumor recurred and was operated on by the same approach. However, only partial removal of the tumor was realized due to difficulties in dissecting the fibrous adhesion. In 1986 (7 years after onset of the symptoms), the patient was readmitted due to severe dysphagia. The sagittal MRI scan demonstrated a huge oval retropharyngeal tumor with precise delineation between the tumor and clivus, clivus upper cervical spine and brain stem. The tumor was extirpated subtotally on the midline via the transoral approach. Dysphagia completely improved postoperatively and the patient regained normal smell sensation. The advantages and disadvantages of the transcervical and transoral approach to clival lesion are discussed and the advantage of the MRI imaging is stressed for preoperative information for the transoral approach.     

Transoral transpalatal removal of a giant premesencephalic clivus chordoma

Summary Due to their surgical inaccessibility and resistance to radiotherapy, clivus chordomas represent a formidable therapeutic challenge. The transoral approach to chordomas of the clivus has been usually restricted to relatively small or midsized neoplasms, located at the lower end of the clivus or at the anterior clival-cervical junction. In this report the transoral transpalatal transclival removal of a giant recurrent chordoma occupying the whole length of the clivus with considerable premesencephalic extension and brain stem compression is described. Regression of preoperative symtoms without additional postoperative morbidity could be achieved by radical transoral tumour extirpation documented by magnetic resonance imaging.     

Endoscopic Endonasal Skull Base Surgery: Advantages,Limitations, and Our Techniques to Overcome Cerebrospinal Fluid Leakage: Technical Note

In recent years, resections of midline skull base tumors have been conducted using endoscopic endonasal skull base (EESB) approaches. Nevertheless, many surgeons reported that cerebrospinal fluid (CSF) leakage is still a major complication of these approaches. Here, we report the results of our 42 EESB surgeries and discuss the advantages and limits of this approach for resecting various types of tumors, and also report our technique to overcome CSF leakage. All 42 cases involved midline skull base tumors resected using the EESB technique. Dural incisions were closed using nasoseptal flaps and fascia patch inlay sutures. Total removal of the tumor was accomplished in seven pituitary adenomas (33.3%), five craniopharyngiomas (62.5%), five tuberculum sellae meningiomas (83.3%), three clival chordomas (100%), and one suprasellar ependymoma. Residual regions included the cavernous sinus, the outside of the intracranial part of the internal carotid artery, the lower lateral part of the posterior clivus, and the posterior pituitary stalk. Overall incidence of CSF leakage was 7.1%. Even though the versatility of the approach is limited, EESB surgery has many advantages compared to the transcranial approach for managing mid-line skull base lesions. To avoid CSF leakage, surgeons should have skills and techniques for complete closure, including use of the nasoseptal flap and fascia patch inlay techniques.     

三种经口入路处理颅颈交界区病变的解剖及比较

目的观察3种经口咽入路达到颅颈交界区的解剖特点。方法通过在尸体标本上模拟各种经口咽入路手术,观察解剖层次,测量手术深度、横向和纵向显露范围,重点对椎动脉与颅、颈神经的位置关系以及各段椎动脉的参数进行测量。结果单纯经口入路能显露从斜坡下1/3到C2椎体下缘的范围,水平向和纵向的显露范围分别为（39.4±2.2）mm和（52.1±3.5）mm。软腭切开后纵向显露范围增加到了（66.7±3.9）mm,能显露到从斜坡中部到C2/C3间隙的范围。上颌骨截骨后能将纵向显露提高到（74.6±5.1）mm,能显露至斜坡上1/3及蝶窦,足够暴露椎-基底动脉汇合点。椎动脉颅外段最宽处在C1横突孔内为（25.5±4.5）mm,最窄处在C2/C3间隙内为（11.2±1.5）mm。结论通过改良经口入路手术能直接将显露范围扩展至斜坡上段和蝶窦,椎动脉的解剖特点使其能作为该术式安全边界的标志。     

Use of the radial forearm microvascular free-flap graft for cranial base reconstruction

OBJECT: Reconstruction of the cranial base after resection of complex lesions requires creation of both a vascularized barrier to cerebrospinal fluid (CSF) leakage and tailored filling of operative defects. The authors describe the use of radial forearm microvascular free-flap grafts to reconstruct skull base lesions, to fill small tissue defects, and to provide an excellent barrier against CSF leakage. METHODS: Ten patients underwent 11 skull base procedures including placement of microvascular free-flap grafts harvested from the forearm and featuring the radial artery and its accompanying venae comitantes. Operations included six craniofacial, three lateral skull base, and two transoral procedures for various diseases. Excellent results were obtained, with no persistent CSF leaks, no flap failures, and no operative infections. One temporary CSF leak was easily repaired with flap repositioning, and at one flap donor site minor wound breakdown was observed. One patient underwent a second procedure for tumor recurrence and CSF leakage at a site distant from the original operation. CONCLUSIONS: Microvascular free tissue transfer reconstruction of skull base defects by using the radial forearm flap provides a safe, reliable, low-morbidity method for reconstructing the skull base and is ideally suited to "low-volume" defects.     

Anterior video-assisted approach to the craniovertebral junction: transnasal or transoral? A cadaver study

Background

Endoscopy represents both an alternative and useful complement to the standard microsurgical approach to the anterior craniovertebral junction (CVJ). Nevertheless, few studies provide an experimental comparison between transnasal and transoral endoscopic control on CVJ. We compared the surgical exposition angle and the working channel volume of both the transnasal and transoral approaches in the cadaver.

Methods

Eleven fresh non-perfused cadavers were studied. Transnasal and transoral linear and angled exposure of the CVJ were evaluated by means of X-ray and CT scan both in sagittal and lateral planes.

Results

The transoral endoscopic surgical exposition was wider compared with the transnasal in anterior and lateral projections:(1)in the sagittal plane, both in vertical exposition (transnasal inferior to transoral from 5.89 % to 76.48 %, average 35.89 %) and in vertical surgical angle (from 22 % to 77.42 %, average 56.53 %); (2)in the coronal plane, both in coronal exposition (transnasal inferior to transoral from 50.77 % to 83.88 %, average 70.34 %) and in coronal surgical angle (from 65.58 % to 86.71 %, average 76.70 %). The sagittal surgical domain was found to spanning from the inferior third of the clivus to C3 with the transoral and from the middle third of the clivus to the nasopalatal line (NPL) with the transnasal approach. The overlapping surgical domain area was found to be the inferior third of the clivus.

Conclusions

The endoscope assisted transoral approach allows a better surgical control of the CVJ. It provides a better CVJ exposure, in sagittal and transverse planes, providing a larger working channel and an easier manoeuvrability. The transnasal approach is limited in caudal direction down to the NPL, otherwise the transoral approach is limited in the rostral direction with a maximum to the foramen magnum in normal specimen. In every individual case, pros and cons of the appropriate approach have to be taken into account as well as the choice of a combined transnasal and transoral approaches strategy.     

扩大经蝶入路显微手术切除斜坡脊索瘤

目的 报道应用扩大经蝶入路治疗斜坡脊索瘤的临床效果.方法 采用扩大经蝶入路显微手术切除斜坡脊索瘤病例9例(均经病理结果证实),所有病例均在神经导航下进行,其中经唇下-扩大经蝶入路4例,经鼻-扩大经蝶入路5例.4例术前通过虚拟现实系统实现图像三维重建,明确肿瘤与周围重要结构的关系,以更好的指导手术入路.结果 肿瘤术中显微镜下及术后影像学证实完全切除3例,肿瘤镜下次全切除(切除比例大于90%)6例.其中2例因肿瘤侵犯至硬脑膜下,肿瘤切除后出现脑脊液漏,经颅底重建修补后痊愈.结论 扩大经蝶入路显微手术可以简单迅速地到达斜坡区域,并能较充分地暴露前颅底、中下斜坡以及双侧海绵窦区,术后并发症少,创伤小,对斜坡脊索瘤来讲是一种较好的手术方式.     

Morphometric measurements of the anterior skull base for endoscopic transoral and transnasal approaches

The objective of this study is to determine the bony limits of the transnasal and transoral approaches to the anterior skull base. The data we present are meant to assist surgeons in preoperative planning for lesions of the sella, clivus, foramen magnum, and odontoid. Using precise measurements undertaken on 41 high-resolution computed tomography scans from patients at the University of Pennsylvania without any history of sinus or sellar pathology, we sought to define the bony limits of transoral and transnasal approaches. Direct measurements and calculated angles were used to assess the dimensions of the anterior skull base. Using our measurements, a transnasal approach can reach an average of 22.5 mm below the plane of the hard palate to the body of C2, and a transoral route can reach 38 mm above the basion along the length of the clivus. Analysis of variance demonstrated no significant differences when subjects were grouped based on race or gender. The measurements outlined within this article help to define the relative dimensions necessary for adapted transoral and transnasal skull base surgeries.     

Surgical approaches to foramen magnum meningioma--report of three cases.

Although foramen magnum meningiomas are usually removable, their location poses considerable surgical risk. The authors present three cases of foramen magnum meningioma. The first involved a ventral type tumor extending to the second cervical body. Following bilateral mandibulotomy, surgery was performed via the anterior transoral approach and the tumor was totally removed. Nine days postoperatively, she developed meningitis, which was successfully treated with antibiotics. The second patient's tumor was dorsal type and was deeply embedded in the lateral part of the vermis. The tumor was totally removed via the midline suboccipital approach and she recovered uneventfully, with only slight upper-extremity paresthesia. In the third case, the tumor was ventral type and situated mainly in the clivus. Craniotomy was performed by the bilateral suboccipital approach and extended nearly to the jugular tubercle. The tumor, which severely displaced the lower cranial and upper cervical nerves, was totally removed. The postoperative course was lengthy and complicated. Artificial ventilation was required for 2 months, and difficulty in swallowing persisted during long-term follow-up. As illustrated by the second case, dorsal and lateral type foramen magnum meningiomas can usually be removed via the lateral suboccipital approach. In the case of ventral type tumors, the anterior transoral approach entails the risk of infection, as occurred in the first case. The authors conclude that the lateral suboccipital approach is preferable; craniotomy extending to the jugular tubercle lowers the risk of brainstem damage.     

Approach to the clivus via maxillary bipartition. Report of a case of chordoma]

Large tumors of the clivus require a combination of several approaches. We review the technique previously described; they cross numerous anatomical structures and include a transcranial approach. We propose to combine transoral and transrhino-septal approaches by means of maxillary bipartition which allows good exposure and an easy removal in a case of chordoma of the clivus.     

Surgical management of anteriorly placed lesions at the craniocervical junction — an alternative approach

Summary Lesions ventral to the neuraxis at the craniocervical junction can pose a significant management problem because of their strategic location. Conventional posterolateral approaches sometimes may not permit adequate visualization of the entire base of the tumor without significant manipulation of the brain stem and spinal cord. The anterior transoral and extrapharyngeal approaches are alternate ways of exposing this region without neural retraction. However, these approaches do not provide adequate exposure of the lateral margins of the tumour, there is no control of the vertebral arteries and cranial nerves and the tumor—brain stem interface is not seen till the end of the operation. A lateral approach is described in this report which involves additional bone removal in the region of the mastoid process and the articular pillars in order to provide a true lateral perspective for the removal of these tumors. The advantages include excellent definition of the interface between the tumor and cord/brain stem without manipulation of the neuraxis, control of the ipsilateral vertrebral artery and caudal cranial nerves, ability to remove the intra- and extradural portions of the tumor in one operation and the ability to perform an immediate bony fusion if necessary. The application of this approach in the management of 9 patients with a variety of intra- and extradural lesions at the clivus and foramen magnum is discussed.     

Transoral approach to extradural lesions of the lower clivus and upper cervical spine: an experience of 19 cases

An experience with 19 cases of transoral exposure of the lower clivus and ventral aspect of the upper cervical spine is presented. The spectrum of pathological entities in this series includes malformative, neoplastic, and spondylotic conditions. The report is designed to focus upon some points of overall surgical management of patients treated by the transoral approach, with emphasis on management of postoperative instability, and to underline the discrepancy in the prognosis of congenital and acquired disorders, in terms of mortality, morbidity, and long-term results.     

Cerebrospinal fluid leak after acoustic neuroma surgery: influence of tumor size and surgical approach on incidence and response to treatment

OBJECT: The aims of this study were to review the incidence of cerebrospinal fluid (CSF) leakage complicating the removal of acoustic neuroma and to identify factors that influence its occurrence and treatment. METHODS: Prospective information on consecutive patients who underwent operation for acoustic neuroma was supplemented by a retrospective review of the medical records in which patients with CSF leaks complicating tumor removal were identified. This paper represents a continuation of a previously published series and thus compiles the authors' continuous experience over the last 24 years of practice. In 624 cases of acoustic neuroma the authors observed an overall incidence of 10.7% for CSF leak. The rate of leakage was significantly lower in the last 9 years compared with the first 15, most likely because of the abandonment of the combined translabyrinthine (TL)-middle fossa exposure. There was no difference in the leakage rate between TL and retrosigmoid (RS) approaches, although there were differences in the site of the leak (wound leaks occurred more frequently after a TL and otorrhea after an RS approach, respectively). Tumor size (maximum extracanalicular diameter) had a significant effect on the leakage rate overall and for RS but not for TL procedures. The majority of leaks ceased with nonsurgical treatments (18% with expectant management and 49% with lumbar CSF drainage). However, TL leaks (especially rhinorrhea) required surgical repair significantly more often than RS leaks. This has not been reported previously. CONCLUSIONS: The rate of CSF leakage after TL and RS procedures has remained stable. Factors influencing its occurrence include tumor size but not surgical approach. The TL-related leaks had a significantly higher surgical repair rate than RS-related leaks, an additional factor to consider when choosing an approach. The problem of CSF leakage becomes increasingly important as nonsurgical treatments for acoustic neuroma are developed.     

Modifications of transnasal and transoral stereotactic procedures — Technical notes

Summary Stereotactic transnasal and and transoral procedures have been reported by different authors in the past. In this paper, several modifications of these methods are described. The modifications are: transnasal approach to the frontal skull base and suprasellar regions; and transoral approaches to the clivus, the petroclival junction, medial part of the cerebellopontine angle and the lateral mass of C-1. Eleven patients were operated on using these modifications. The procedures were for biopsy and brachytherapy. No complications resulted from the procedures.     

Transoral operations for craniospinal malformations

The transoral approach to the lower third of the clivus and to the ventral aspect of the upper cervical spine is used in craniospinal malformations with or without dislocation as well as in basilar aneurysms, ventrally situated cranio-spinal tumours, fractures of the odontoid process, and in rheumatoid arthritis compressing the spinal cord. In consideration of the literature and ten personal cases the indications and techniques of the transoral approach in craniospinal malformations are discussed. According to our own experiences and those of other authors it is possible to expose the lower clivus and the cervical spine down to C2 by a midline incision of the pharyngeal wall using a mouth retractor and oral intubation. Splitting of the soft palate or resection of the hard palate are not necessary, a tracheotomy should be performed only in exceptional cases. In congenital craniospinal malformations without dislocation or instability causing a ventral compression of the spinal cord, for instance by the odontoid process, the transoral decompression is preferable to dorsal decompressing operations. In cases of pure instability without any space-occupying lesion the transoral and posterior approach are possible in order to perform a fusion. The last one seems more advantageous in these cases. In craniospinal malformations with dislocation causing a ventral and dorsal narrowing of the spinal canal, apart from the decompression a stabilization has to be achieved. In these usually complex malformations individual treatment is necessary. According to the rare cases in the literature and to our own experience a primary anterior decompression, followed by a most careful posterior stabilization seems to produce the most favourable results.     

Transoral Approach and Extended Modifications for Lesions of the Ventral Foramen Magnum and Craniovertebral Junction

Objectives: To describe our method of performing the transoral approach and the extended approaches to the ventral foramen magnum and craniovertebral junction and review the technical aspects and operative nuances. Design: Review. Results: The transoral approach provides direct midline exposure to access extradural disease located at the craniovertebral junction and ventral foramen magnum. The corridor of exposure is generally limited by the extent to which the patient can open his or her mouth. The location of the hard palate relative to the craniovertebral junction limits superior exposure, whereas the mandible and base of the tongue limit the inferior exposure. In most cases, exposure can be obtained from the inferior clivus to the middle to lower C2 vertebral body. Extended transoral approaches can be performed to increase exposure if necessary. These approaches include transmaxillary (Le Fort I maxillotomy), transmaxillary with a midline palatal split (extended “open-door” maxillotomy), transpalatal, and median labiomandibular glossotomy (transmandibular split). Conclusions: The transoral approach effectively provides direct access to extradural midline lesions of the craniovertebral junction. A specialized retractor system can expose the inferior clivus to the C2 body. Extended approaches as described can access lesions that extend beyond these limits.     

Endoscopic transoral surgery for craniovertebral junction anomalies. Technical note

Craniovertebral junction (CVJ) anomalies continue to be challenging for neurosurgeons because of the complex anatomy of this region. To date, microsurgical decompression via a transoral route is the standard treatment for anteriorly located compressive lesions of the cervicomedullary junction (CMJ). The results obtained by minimizing surgical trauma are fewer complications, shorter hospital stays, and reduced overall psychological burden. Endoscopic surgery is becoming a leading modality in minimally invasive neurosurgical treatment. The authors performed surgery in 11 patients with irreducible osseous dislocations resulting from CVJ abnormality during a 2-year period. Anterior CMJ decompression was achieved in all patients by performing neuroendoscopically controlled transoral excision of bone and soft tissues. The surgical technique and results will be discussed. The use of the endoscope offers several advantages in cases requiring a transoral approach to the lower clivus and atlantoaxial region. The use of minimally invasive endoscopic techniques has the potential to reduce the need for a wider cranial base opening and to decrease postoperative complications.