Effect of dynamic traction technique on postoperative complications, stress response and neurological function recovery in patients with petroclival meningioma undergoing microscopic resection / 中国医师进修杂志

Objective:To investigate the effect of dynamic traction technique on postoperative complications, stress response and neurological function recovery in patients with petroclival meningioma undergoing microscopic resection.Methods:The clinical data of 80 patients with petroclival meningioma in Huanggang Central Hospital of Hubei Province from January 2017 to December 2019 were retrospectively analyzed. Among them, 38 cases were treated with automatic retractor technique (automatic traction group), and 42 cases were treated with dynamic traction technique (dynamic traction group). The operation time, postoperative hospital stay, postoperative complications of brain traction injury and the degree of Simpson tumor resection were compared between 2 groups. The levels of serum stress indexes before and after operation were detected, including C-reactive protein (CRP), interleukin-6 (IL-6) and white blood cell count (WBC). Karnofsky performance status (KPS) score was performed 6 months after operation, and the recovery rate of neurological function (KPS score≥80) and recurrence rate were counted.Results:There were no significant differences in operation time, postoperative hospital stay and the degree of Simpson tumor resection between 2 groups ( P>0.05). The incidence of postoperative complications of brain traction injury in dynamic traction group was significantly lower than that in automatic traction group: 4.76% (2/42) vs. 21.05% (8/38), the recovery rate of neurological function 6 months after operation was significantly higher than that in automatic traction group: 83.33% (35/42) vs. 39.47% (15/38), and there were statistical differences ( P<0.05 or<0.01). The serum CRP, IL-6 and WBC in dynamic traction group were significantly lower than those in automatic traction group: (24.11±5.86) mg/L vs. (28.42±5.94) mg/L, (10.52±2.29) pg/L vs. (12.45±2.46) pg/L and (9.24±2.43) ×10 9/L vs. (10.84±2.38) ×10 9/L, and there were statistical differences ( P<0.01). No recurrence was found in both groups. Conclusions:Dynamic traction technique in microscopic resection of petroclival meningioma can effectively reduce the postoperative complications of brain traction injury, reduce surgical stress, promote the recovery of neurological function, and improve the prognosis of patients.

Palsy of the Contralateral Abducens Nerve after Aneurysm Surgery and Temporal Meningioma in the Presence of Petroclival Meningioma: A Case Report

The sixth abducens nerve is subject to injury after rare complications of intracranial hypotension caused by procedures such as dural punctures and spinal surgeries. The purpose of this case report is to discuss the mechanism of nerve palsy in these situations. Therefore, we describe a case of onset of contralateral sixth cranial nerve palsy after intracranial aneurysm and temporal meningioma surgery. Moreover, in this case there is a singularity due to the presence of the petroclival meningioma that amplified the unfolding of the lesion.

O sexto nervo abducente está sujeito a lesões após raros eventos de hipotensão intracraniana gerada por procedimentos como punções de dura-máter e cirurgias de coluna. O propósito deste relato de caso é discutir o mecanismo da paralisia deste nervo nestas situações. Para isso, descrevemos um caso de aparecimento de paresia do sexto nervo craniano contralateral após cirurgia de aneurisma intracraniano e de meningioma temporal. Além do mais, neste caso há uma singularidade em razão da presença do meningioma petroclival contralateral, que amplificou o desdobramento da lesão.

Meningiomas petroclivales: estrategia quirúrgica endoscópica a propósito de dos casos / Petroclival meningioma: endoscopic approach and case report

A pesar del desarrollo de las técnicas quirúrgicas de base de cráneo, los meningiomas petroclivales constituyen un reto para el neurocirujano debido a su localización y relación con estructuras neurológicas y vasculares críticas. Se reportan 2 pacientes con diagnóstico de meningioma petroclival que recibieron tratamiento por etapas incluyendo derivación ventrículo peritoneal asistida por endoscopia para la hidrocefalia, abordaje endonasal endoscópico (AEE) extendido al ápex petroso, keyhole subtemporal y retromastoideo con remoción de la lesión. La evolución fue satisfactoria. Se concluyó que los abordajes endoscópicos y por etapas constituyen una excelente opción en el tratamiento de los meningiomas petroclivales.

In spite of the development of the skull base surgery techniques, petroclival meningiomas are a challenge for neurosurgeon due to their localization and relationship with neurovascular structures. Those are two patient with diagnostic of petroclival meningioma whom received treatment step by step included ventricle peritoneal shunt with endoscopic guide for hydrocephalus, extended endonasal approach to petrous apex, subtemporal and retrosigmoid keyhole. The endoscopic approach is an excellent option in the treatment of petroclival meningioma.

Meningioma petroclival. abordaje petroso combinado con extensión translaberíntica / Petroclival meningioma. petrosus approach combined with translabyrinthine extension

Objetivo: Presentar un caso de meningioma petroclival con extensión al cavum de Meckel, tratado quirúrgicamente a través de un abordaje petroso combinado con extensión translaberíntica. Introducción: Se define como meningioma petroclival, al que se origina en los dos tercios superiores de la fisura petroclival, y medial al nervio trigémino. Existen numerosos abordajes para estos tumores, y cada caso requiere un análisis individualizado. Descripción del caso: Paciente de 25 años que refiere cefalea de 6 meses de evolución, progresiva e invalidante, e hipoacusia derecha. Al examen físico presenta hipoestesia en territorio trigeminal derecho y desviación velopalatina a derecha. En la imagen de resonancia magnética (IRM) se evidencia voluminosa lesión expansiva petroclival derecha con extensión al cavum de Meckel. La cirugía fue programada en dos tiempos: en el primero se realizó el abordaje y en el segundo la exéresis tumoral total. En el post operatorio evolucionó con una hemiparesia izquierda transitoria y parálisis completa del tercer par derecho en recuperación. Discusión: Existen múltiples modalidades terapéuticas para los meningiomas de base de cráneo. En este caso considerando la ubicación, el tamaño, su extensión clival, al cavum de Meckel y su relación con la arteria basilar, se decidió realizar un abordaje petroso combinado, con extensión translaberíntica debido a la hipoacusia. Conclusiones: Los abordajes de base de cráneo acortan la distancia de trabajo al tumor y mejoran los ángulos de exposición, facilitando su exéresis. Su principal desventaja, que es el tiempo de realización, puede sortearse dividiendo la cirugía en 2 tiempos.

Objective: To present a patient with a right petroclival meningioma with extension into Meckel´s cave, surgically treated by combining a petrosal approach with translabyrinthine extension.Introduction: Petroclival meningiomas are tumors that arise from the upper two thirds of the petroclival fissure, medial to the trigeminal nerve. There are several treatment options, with every case warranting an individualized approach.Case description: Our patient was a 25-year-old male/female with a 6-month history of progressive, disabling headaches and right hearing loss. The physical exam revealed right trigeminal hypoesthesia and rightward deviation of the soft palate. Magnetic resonance imaging detected a huge right petroclival tumor with extension into Meckel´s cave. Two-stage surgery was planned, the first procedure to create an approach, and the second to attempt total tumor resection, which was achieved. Postoperatively, the patient had transient left hemiparesis and a complete third nerve palsy that recovered partially. Discussion: Many different surgical approaches exist for treating petroclival meningiomas. In this case, considering the tumor’s location and volume, its clival and Meckel´s cave extension and basilar artery involvement, we elected to combine a petrosal approach with translabyrinthine extension, due to the patient’s previous hearing loss. Conclusion: Skull-base approaches shorten the working distance to the tumor, improving the angle of approach and rendering total resection possible. One of the procedure’s main disadvantages is the time required; but this can be overcome by performing the procedure in two stages.

Cirugía endoscópica endonasal extendida a la región Petro-Clival / Ápex Petroso. Reporte de un caso y revisión de la literatura / Endonasal endoscopic surgery extended to the Petro-Clival / Petrópe region. Case report and literature review

INTRODUCCIÓN: las indicaciones de la cirugía endoscópica endonasal en el tratamiento de tumores de base de cráneo continúan expandiéndose, sobre todo para los tumores extradurales, como son los cordomas. A partir de un caso, nuestro objetivo fue revisar la literatura relevante de estos desafiantes tumores operados bajo esta técnica. CASO CLÍNICO: paciente de 59 de edad con antecedentes de depresión mayor, que comenzó con un cuadro de diplopía por compromiso del VI par izquierdo. Los estudios (CT y RM) mostraron un proceso expansivo en la región del ápex petroso. Se realizó un abordaje endoscópico extendido a la región petro-clival con resección tumoral subtotal. Buena evolución postquirúrgica con desaparición de su diplopía. El diagnóstico histológico fue de Cordoma Condroide. Se indicó radioterapia adyuvante. DISCUSIÓN: a partir del conocimiento y la experiencia en el manejo endoscópico de la patología intraselar se desarrollaron abordajes para el tratamiento de patologías que comprometen la fosa anterior, media e inclusive la fosa posterior. Actualmente, los abordajes endoscópicos, se han extendido a otras áreas de la base de cráneo que de otro modo presentan un reto técnico para la exposición a través de los abordajes transcraneales habituales. El abordaje endoscópico endonasal ofrece una ruta quirúrgica adecuada para la resección del tumor que se presenta en este caso. Las vías que pueden ser utilizados para llegar a la región petroclival a través de la acceso endonasal incluyen la medial (con o sin la movilización de ACI) y la infrapetrosa transterigoidea. En este reporte de caso se analizan las indicaciones del abordaje endoscópico endonasal basado en una revisión de la literatura. CONCLUSIÓN: el abordaje endoscópico endonasal extendido se presenta como una alternativa segura para el tratamiento de determinadas lesiones petro-clivales. Se requieren más estudios anatómicos y clínicos para establecer mejor el rol de este tipo de técnicas en el manejo de las lesiones localizadas en esta región

INTRODUCTION: indications for endoscopic endonasal surgery for the treatment of skull base tumors continue to expand, particularly for extradural tumors, such as chordomas. Based on this case report presentation, we aim to review the literature on the endoscopic technique relevant to the management of these challenging tumors. CASE REPORT: a 59 year-old woman who presented with diplopia due to left sixth nerve palsy underwent imaging studies (CT, MRI) that revealed a mainly intra-osseous expansive process of the left petrous apex. An expanded endoscopic endonasal approach to the petroclival region was performed and the tumor was subtotally resected. The patient recovered from surgery with resolved diplopia. Histopathology was compatible with chondroid chordoma. The radiation therapy was indicated after surgery. DISCUSSION: built upon the bulk experience on the treatment of intrasellar pathology, endonasal endoscopic approaches have been developed for the treatment of skull base lesions involving the anterior, middle and even posterior cranial fossae. Nowadays, the use of these techniques has spread to other areas of the skull base, which otherwise present as a formidable technical challenge for exposure through transcranial approaches. The endonasal endoscopic approach provides an adequate surgical corridor for the resection of the tumor presented in this case report. The alternative corridors that can be utilized to reach the petroclival region through the endonasal endoscopic route include the medial corridor (with or without ICA mobilization) and the transpterygoid infrapetrous corridor. In this article, we discuss the indications for the endoscopic endonasal approach for the case presented, and discuss our choice of approach based on our review of the literature. CONCLUSION: the extended endoscopic endonasal approach presents as a safe alternative for the treatment of select petroclival lesions. Further anatomical and clinical studies are required to better establish the role of the endoscopic endonasal approach for lesions located in this region

Nuances in the Treatment of Malignant Tumors of the Clival and Petroclival Region

Introduction: Malignancies of the clivus and petroclival region are mainly chordomas and chondrosarcomas. Although a spectrum of malignancies may present in this area, a finite group of commonly encountered malignant pathologies will be the focus of this review, as they are recognized to be formidable pathologies due to adjacent critical neurovascular structures and challenging surgical approaches. Objectives: The objective is to review the literature regarding medical and surgical management of malignant tumors of the clival and petroclival region with a focus on clinical presentation, diagnostic identification, and associated adjuvant therapies. We will also discuss our current treatment paradigm using endoscopic, open, and combined approaches to the skull base. Data Synthesis A literature review was conducted, searching for basic science and clinical evidence from PubMed, Medline, and the Cochrane Database. The selection criteria encompassed original articles including data from both basic science and clinical literature, case series, case reports, and review articles on the etiology, diagnosis, treatment, and management of skull base malignancies in the clival and petroclival region. Conclusions: The management of petroclival malignancies requires a multidisciplinary team to deliver the most complete surgical resection, with minimal morbidity, followed by appropriate adjuvant therapy. We advocate the combination of endoscopic and open approaches (traditional or minimally invasive) as required by the particular tumor followed by radiation therapy to optimize oncologic outcomes...

Clinical analysis of using temporal base transtentorial approach to resect tumors in petroclival region / 中国医师进修杂志

Objective To discuss the surgical method of resection of petroclival tumors used temporal base transtentorial approach.Methods Analyzed 26 cases of petroclival tumors.All of them were surgically treated under intraoperative neurophysiological monitoring by temporal base transtentorial approach.Firstly the supratentorial part of tumors were resected by pieces,and then the tentorium was cut open,in order to resect residue of the subtentorial part of tumors.This surgical maneuver was applied to reduce the retraction to surrounding vessels,nerves and brain stem,as well to protect important structures and to finally achieve radical removal of the tumors.The efficacy and complications were observed.Results Among 26 cases,19 cases (73.1％,19/26) achieved total removal,5 cases (19.2 ％,5/26) achieved subtotal removal and 2 cases (7.7％,2/26) achieved great partial removal.There was no surgery-related death.Eleven cases suffered from partial neurological deficit.All cases were followed up for 3 months to 4 years,3 cases underwent complete recovery,4 cases underwent partial recovery,and 4 cases underwent permanent deficit.Conclusions Using temporal base transtentorial approach to resect petroclival tumors is convenient,applicable,safe and with minimal injury and with high proportionality of total resection.Under intraoperative neurophysiological monitoring,this approach may be an ideal choice for surgical treatment of these tumors.

The microsurgical anatomy of the modified presigmoid transpartial bony labyrinth approach / 中华显微外科杂志

Objective To investigate the surgical techniques of the modified presigmoid trans-partial bony labyrinth approach and the advantages in exposure of the petroclival region and in treat the lesion of this area.Methods By simulate the modified presigmoid trans-partial bony labyrinth approach in 15 adult cadaveric heads with the aid of an operating microscope and record important structures in the petroclival region.Results The petroclival region,the posterior cavernous sinus,Meckel cave,the vertebral-basilar artery,the anterior inferior cerebellar artery,the superior cerebellar artery,ipsilateral Ⅲ-Ⅹ cranial nerve nere fully exposured and contralateral Ⅵ cranial nerve were fully exposured.The range of presigmoid exposure was (19.41 ± 1.58)mm,the exposurein of inferior temporal was (14.18 ± 1.88) nun,the maximum exposure angle of slope center depression was (60.54 ± 6.93) °,the depth of operation was (55.87 ± 4.34) mm.Conclusion The advantages of the modified presigmoid trans-partial bony labyrinth approach can earn enough exposures of deep part of petroclival region and posterior part of cavernous sinus,improved petroclival exposure,multiple axes of visualization,preservation of hearing and facial nerve function,and early devascularization of the tumor.

A Case of Aberrant Abducens Nerve in a Cadaver and Review of Its Clinical Significance

The abducens nerve usually travels from the brainstem to the lateral rectus muscle as a single trunk. However, it has been reported that this nerve could split into branches occasionally. We attempted to show the aberrant course of abducens nerve in a specimen with unilateral duplicated abducens nerve and review relevant literatures. The micro-dissections were performed in a head specimen injected with colored latex under the microscope. The abducens nerve was duplicated unilaterally. This nerve emerged from the pontomedullary sulcus as a single trunk and splitted into two branches in the prepontine cistern. These two separate branches were piercing the cerebral dura of the petroclival region respectively. The slender lower branch passed between the petroclinoid and petrosphenoid ligaments and the thick lower one passed under the petrosphenoid ligament. These two branches united just lateral to the ascending segment of internal carotid artery in the cavernous sinus. The fact that there are several types of aberrant abducens nerve is helpful to perform numerous neurosurgical procedures in the petroclival region and cavernous sinus without inadvertent neurovascular injuries

Isolated Petroclival Craniopharyngioma with Aggressive Skull Base Destruction

We report a rare case of petroclival craniopharyngioma with no connection to the sellar or suprasellar region. MRI and CT images revealed a homogenously enhancing retroclival solid mass with aggressive skull base destruction, mimicking chordoma or aggressive sarcoma. However, there was no calcification or cystic change found in the mass. Here, we report the clinical features and radiographic investigation of this uncommon craniopharyngioma arising primarily in the petroclival region.

Significance of Cerebral Venography in Surgery of Petroclival Meningiomas

OBJECTIVE: A thorough understanding of the related venous structure is mandatory for successful removal of the petroclival meningiomas. This study was planned to investigate the guideline for safe ligation and incision of transverse or sigmoid sinuses and the importance of drainage pattern of vein of Labb in surgical removal of petroclival meningiomas. MATERIALS AND METHODS: The authors reviewed the venogram of the consecutive 37 cases of petroclival meningiomas and retrospectively analyzed their surgical findings. The drainage pattern of confluence of Herophili was classified as Type A(confluent and equal on both sides), Type B(confluent and non-dominant on tumor side), Type C(confluent and dominant on tumor side) and Type D(unilateral drainage only) as these findings gave the information on safe ligation and resection of the sinus. Usefulness of intraoperative test clamping of sinus for safe ligation was also reviewed. The vein of Labb was analyzed with respect to its draining point and its collaterals to other superficial veins. RESULTS: Contraindications of the sinus ligation and resection according to the drainage pattern at the confluence of Herophili were Type C(n=10, 27%)and Type D(n=4, 11%). Patients with Type A(n=12, 32%)and Type B(n=11, 30%) were tolerable to sinus ligation ipsilateral to tumor, if the test clamping proved to be safe. Identification of no brain swelling, after intraoperative test clamping of the sinus for more than 30 minutes performed in 7 out of 11 cases, was a reliable indicator of safe sinus ligation. The drainage pattern of the vein of Labb, especially low-lying type, could predict the possibility of postoperative hemorrhage and infarction. Its drainage into tentorium or superior petrosal sinus, however, made the transtentorial approach impossible, leading to restricted operative field. CONCLUSION: For a successful removal of the petroclival meningiomas preoperative venogram should be examined carefully. The extent of exposure in a planned approach can be estimated by analyzing the variation of sinuses and the drainage pattern of vein of Labb.

Keyhole approach surgery for petroclival meningiomas / 中华显微外科杂志

Objective To evaluate the possibility of keyhole approaches for surgical treatment of petroclival meningiomas. Methods We retrospectively analyzed our experience in 14 cases with petroclival meningiomas surgically treated from May 2003 to January 2004. Eight tumors involved the upper and middle clivus.five tumors were attached to the entire width of clivus and one tumor involved the middle and lower cilvus. The tumors infiltrated into parasella regions or cavernous sinus in six cases simultaneously. Retrosigmoidal keyhole approach was selected to remove the tumors in 6 cases, and subtemporal keyhole approach was selected in 2 cases,while the combined retrosigmoidal and subtemporal keyhole approaches were applied in other six cases. Results Gross total resections of the tumors were achieved in 8 cases, subtotal resections in 4 cases, large resection in two cases who had recurrent tumors. Postoperatively, neurological intact or unchanged were found in 8 cases. The main surgical complications were mild facial palsy (4 cases) , abducent dificits (3 cases) ,temporary oculomotor nerve dificits (2 cases),and lower cranial nerve palsy (1 case). One patient died from disseminated intravascular coagulation (DIC) two weeks after surgey. There were no CSF leakage and infections after surgery in all cases 11 to 19 months follow-up studies demonstrated the great improvement of the Ⅲ and Ⅶ nerve deficits,but minor improvement in the Ⅵ nerve deficits. Conclusion According to the location and extension of the tumors, retrosigmoidal or subtemporal keyhole approaches or their combined can be selected for surgical treatment. These keyhole approaches can expose sufficiently the petroclival region, shorten the surgical time, and minimize the complications. Combined usage of minimally invasive techniques including the keyhole approach and radiosurgey in the treatment of the petroclival meningiomas is suggested.

Microsurgical treatment of petroclival tumors by transpetrosal presigmoid approach / 中华显微外科杂志

Objective To explore clinical curative effect of microsurgery of petroclival tumors by transpetrosal presigmoid approach. Methods A series of 23 patients of petroclival tumors resected by microneurosurgery were analyzed retrospectively, including tumors histological types, clinical and preoperative MRI features, operative approaches, surgical technique and common postoperative complications. Results Total resection of the tumor was achieved microsurgically in 16 cases, subtotal resection in 4 cases, partial resection in 3 cases. No patient died in this series. 8 patients presented worsening crainal nerves palsies postoperatively. CSF leaks were uncommon, occuring in 2 patients. Conclusion The tumors in petroclival region can be totally resected by transpetrosal presigmoid approach. The advantages were offered by this approach such as the temporal lobes and cerebellum are minimally retracted; the operative distance of petroclival tumors is shortened with exposure of clivus and juxta-clival region.

Modified Transpertrosal(mini-petrosal) Approach to Petroclival Tumors: Technical Note

The management of petroclival tumors has been improved by the techniques of cranial base surgery. However, these tumors are still among the most difficult cranial base lesions to treat. The t ranspetrosal approach is a routine procedure for petroclival tumors, but there are some disadvantages such as the time-consuming craniotomy during surgery. CSF leakage due to incomplete dural closure, postoperative infection, epidural hematoma and depressed deformity of the mastoid area after surgery. To solve these disadvantages, we modified the transpetrosal approach to mini-pet rosal technique involving total petrosectomy without temporal or suboccipital craniotomy. 11 petroclival tumors were operated on using this technique between August 1994 and August 1997. Gross total removal was achieved in tumors of up to 4cm diameter by this technique. The advantages of this approach are smaller skin incision, shorter operation time, and less postoperative complications such as epidural hematoma, CSF leakage infection, and headache. This technique can be indicated for medium to large petroclival tumors which do not extend to cavernous sinus and Jugular foramen.

Surgical Removal of Large Petroclival Meningiomas: the Transpetrosal Approach

For surgery involving complex lesions of the petroclival region, the transpetrosal approach-which may be anterior or posterioris known to have distinct advantages over traditional approaches. Six patients with large petroclival meningiomas(over 4.5cm), underwent surgery. In three cases, where the lesion extended only into the posterior fossa, the posterior transpetrosal approach was used, and in the other three, where it extended into the Meckels cave or cavernous sinus, surgery involved a combined anterior-posterior transpetrosal approach. In three cases with serviceable hearing, the retrolabyrinthine technique was employed, the remaining three, without serviceable hearing, were subjected to the translabyrinthine technique. Total removal was achieved in three cases(50%), and no patient died. Immediate postoperative neurological dysfunction appeared in all cases; almost all involved new cranial nerve deficit. As time passed, this dysfunction became less serious, though in four cases, it was permanent; there was mild to moderate hemiparesis in two cases and facial nerve paralysis in two. The surgical outcome was good in four cases, fair in one and poor in one. The authors suggest that the selection of surgical approach to petroclival meningiomas should be based upon the size and location of the tumor, the extent of dural attachment and the status of the patient's hearing. For a high-risk group, with brain stem invasion, arterial and cranial nerve encasement and cavernous sinus invasion, subtotal resection of the tumor is recommended.

Petrosal Approach to Petroclival Meningiomas: Experience with 3 Cases

The authors report three patients of large petroclival meningiomas which were operated by retrolabyrinthine(petrosal) approach. This technique maximizes temporal bone drilling and therefore provide exquisite exposure of the clival and petrous regions with minimal brain retraction. The superior petrosal sinus is sacrificed and the tentorium completely cut. The sigmoid sinus on the other hand can be preserved, depending on the venous drainage and the degree of exposure required.

Surgical Experiences of Transpetrosal Approach in Petroclival Lesions

This is a report of 15 consecutive cases of petroclival lesions performed by transpetrosal approach over five years. Pathologies from these cases include 13 cases of tumors and two cases of aneurysms. All cases of tumors were over 4.5cm in size. Two cases of very low-lying basilar bifurcation aneurysms and one case of facial schwanoma extended to the petrosal tip and temporal fossa were operated with anrerior transpetrosal approach, where as nine cases of petroclival tumor which was localized in the posterior fossa were operated via posterior transpetrosal approach. Of these nine cases, one case with lower clival extension was removed totally by adding a retrosigmoid dural opening. Remaining three cases extended to the Meckel's cave or cavernous sinus were operated by combined anterior-posterior transpetrosal approach. Of the 12 cases done with posterior transpetrosal or combined approach, nine cases with preserved serviceable hearing were approached by retrolabylinthine technique and remaining three cases without preservation of serviceable hearing were operated via retrolabylinthine technique. Total removal was achieved in 9 of 13 tumor cases. Of two cases, aneurysmal neck of the first case was clipped completely but was clipped together with right posterior cerebral artery in second case. There was no operative mortality. Immediate postoperative neurological dysfunction were appered in 12 cases. These were significantly improved by the time of follow up examination. Permanent postoperative dysfunction was present in 6 cases, hemiparesis in 2, facial paralysis in 2 and hearing impairment in 2 cases. These results suggest that when selecting the surgical approach to the petroclival lesions, the size, location, extent of the lesion and preoperative status of the hearing were important factors to be considered. We recommend combined anterior-posterior transpetrosal approach for the complex lesions in the petroclival area which extends into the middle fossa(Meckel's cavum or cavernous sinus). Also, we recommend combining with retrosigmoid dural opening or a far lateral type of suboccipital exposure in cases of complex petroclival lesions involving the entire clivus or foramen magnum. In cases with brain stem invasion by tumor, vascular encasement or cavernous sinus invasion without cranial nerve involvement, we recommend subtotal resection of the tumor and radiosurgery to prevent permanent postoperative sequele.

Posterior Transpetrosal Transtentorial Approach for Tumors of the Petrous and Clival Regions: Experience with 25 Consecutive Cases

Because of their proximity to adjacent vital structures, and deep and narrow operative field in the surrounding compact bony structures, tumors located in the clival or petroclival regions represent a formidable technical challenge to neurosurgeons. Between April 1990 and May 1996, 25 patients(eight males and 17 females with a mean age of 44 years), harboring clival or petroclival tumors underwent surgery in our department involving the posterior transpetrosal transtentorial approach. The median follow-up period was 24 months. A total of 28 operations were performed ; in three cases, these involved two stages, in which different approaches were used. The surgical pathology included 15 meningiomas, seven neurinomas(four acoustic and three trigeminal), and one case each of myxoid chondrosarcoma, chondroid chordoma, and paratrigeminal epidermoid. Tumor size ranged from 2 to 8cm ; 16 were larger than 4cm. According to the extent of petrous resection, three different approaches were used ; retrolabyrinthine in ten cases, translabyrinthine in four, and transcochlear in eleven. The superior petrosal sinus was always sacrificed and the tentorium completely cut. Gross total removal was accomplished in 13 cases, and subtotal removal in 12. The causes of incomplete removal included cavernous sinus invasion in four cases, severe adhesion to the brain stem in two, extremely high consistency and vascularity of the tumor in two, insufficient exposure to the tumor in two, and unexpected residual tumors seen in two cases on postoperative MRI. There was no operative mortality in this series and the most common complication was cranial nerve palsy, which occurred in 15 cases. Other complications included hemiparesis in two cases, CSF leakage in two and an epidural hematoma in one. The authors conclude that the posterior transpetrosal transtentorial approach is advantageous for resecting petroclival tumors because, by avoiding unnecessary brain retraction, it significantly reduces the risk of postoperative complications, and helps provide shorter access and wider exposure of the lesion.