Infralabyrinthine approach for cholesterol granuloma of the petrous apex

Cholesterol granuloma of the petrous apex are cystic lesions, revealed by otologic and/or cranial nerve palsies, and diagnosed with the help of computed tomography and magnetic resonance imaging. Surgical treatment is not the complete removal of the lesion, but a conservative approach requiring drainage of the cyst and re-establishment of a correct aeration of the cavity. Three cases of cholesterol granuloma of the petrous apex were treated through a transmastoid infralabyrinthine procedure. Through a postauricular approach, a simple mastoidectomy was performed. The third portion of the facial nerve was identified. The posterior and lateral semicircular canals, and the jugular bulb were skeletonized. In two cases, a high diverticulum of the jugular bulb was impacted downwards with wax. The cystic lesion was then opened, and evacuated. The opening must be large to permit a correct aeration of the cavity and prevent stenosis of the drainage site. Hearing and the facial function were preserved in all cases. In conclusion, conservative approach to cholesterol granuloma of the petrous apex provides satisfactory drainage of this intrapetrous deep seated lesion with preservation of hearing and facial nerve function.     

Transcanal infracochlear approach to the petrous apex

Computerized tomography and magnetic resonance imaging have now made it possible to reliably differentiate cholesteatoma from cholesterol granuloma of the petrous apex. The treatment for cholesteatoma is complete surgical excision when possible, whereas cholesterol granuloma needs only adequate drainage for control. A new transcanal infracochlear approach for drainage of cholesterol granuloma involving the anterior petrous apex is described. Absolute measurements from 10 cadaveric temporal bones were obtained to determine the distances between the cochlea, jugular bulb, carotid artery, and facial nerve. In all specimens the petrous apex was entered without invading the cochlea, carotid, or jugular bulb. Advantages of this technique include a more direct route to the petrous apex, dependent drainage, and preservation of the normal hearing mechanism, including the tympanic membrane. Clinical indications for this technique include failure of other treatment approaches and a high jugular bulb obstructing an infralabyrinthine approach. Experience to date shows that patients experience little difficulty from the procedure.     

Endoscopic balloon dilation as an adjunct to extended endoscopic approaches to the skull base

Cholesterol granulomas (CGs) are benign, expanding cystic lesions surrounded by a thick fibrous capsule and filled with fluid, formed by the degradation of blood elements. The goal of surgery is to open the granuloma widely, creating a well-drained cavity. The endonasal endoscopic approach for this extradural lesion is a minimal access method for surgical removal or fenestration. The role of balloon dilation in creating a wide fenestration has not been previously described. The authors describe a patient with a recurrent petrous apex CG who underwent an endoscopic, endonasal, transmaxillary transpterygoid approach to the petrous apex. A balloon sinuplasty catheter was used to dilate the surgical fenestration to maintain continued patency. The authors report on their first experience using balloon dilation combined with endoscopic drainage of the petrous apex. The excellent surgical outcome of this minimally invasive technique holds promise for future endonasal approaches to the middle cranial fossa.     

Endoscopic management of a giant cholesterol cyst of the petrous apex

Giant cholesterol cyst (GCC) of the petrous apex is a rare clinical entity. This benign cystic lesion can cause neurologic deficits and vascular compromise by persistent growth and progressive bone destruction. Magnetic resonance imaging studies of GCC show the lesions to be hyperintense on T(1)-weighted sequences with progressively lower signal intensities on the first and second echoes of T(2)-weighted sequences. These findings are relatively specific for GCC, permitting a narrow differential diagnosis. The goal of surgery is to provide adequate drainage with the creation of a permanent fistula. The classic approaches to these lesions are the posterior fossa craniotomy and the middle fossa extradural craniotomy. The translabyrinthine approach provides wide exposure at the expense of cochlear and vestibular function. The transsphenoidal approach provides adequate drainage with hearing preservation and no craniotomy. The endoscopic, endonasal transsphenoidal approach to a 2.5 cm GCC of the petrous apex accomplished complete drainage with the creation of a fistula. Advances in endoscopic technique and instrumentation facilitated the addition of the approach to the surgeon's armamentarium. In selected cases, this approach provides adequate surgical exposure with minimal morbidity.     

A novel treatment approach to cholesterol granulomas. Technical note

The authors report a novel technique for the treatment of cholesterol granulomas. An extradural middle fossa approach was used to access the granuloma, with drainage through silastic tubes into the sphenoid sinus via the anteromedial triangle between V1 and V2. Cholesterol granulomas occur when the normal aeration and drainage of temporal bone air cells is occluded, resulting in vacuum formation and transudation of blood into the air cells. This process results in anaerobic breakdown of the blood with resulting cholesterol crystal formation and an inflammatory reaction. Traditional treatment of this lesion involves extensive drilling of the temporal bone to drain the granuloma cyst and establish a drainage tract into the middle ear. Such drainage procedures can be time consuming and difficult, and potentially involve structural damage to the inner ear and facial nerve. An extradural middle fossa approach provides easy access to the granuloma and anterior petrous bone entry into the granuloma for resection. Granuloma drainage is then achieved using shunt tubing in the sphenoid sinus via a small hole in the anteromedial triangle between V1 and V2. Five patients with symptomatic cholesterol granuloma were treated without complication using this novel extradural middle fossa approach. One patient required reoperation 1-year postoperatively for cyst regrowth and occlusion of the drainage tube. At the 5-year follow-up examination, no patient reported recurrent symptoms. Extradural middle fossa craniotomy and silastic tube drainage into the sphenoid sinus is a viable alternative method for treatment of cholesterol granuloma.     

Hearing Outcomes after Surgical Drainage of Petrous Apex Cholesterol Granuloma

Objective This study aims to assess the hearing outcomes of patients undergoing surgical management of petrous apex cholesterol granuloma and to discuss the role of otic capsule–sparing approaches in drainage of petrous apex cholesterol granulomas. Design Retrospective case series. Setting Tertiary care medical center. Participants Eight patients underwent surgery for presumed or definitive cholesterol granuloma between 2002 and 2011 and met the inclusion criteria for this study. Main Outcome Measures Pre- and postoperative audiogram results as measured by pure tone thresholds and word recognition scores. Results Four patients (50%) demonstrated improvement in speech discrimination. One patient had an increase from 0 to 67% in word recognition scores. Four patients (50%) demonstrated worsening of pure tone thresholds, including two patients with anacusis. Conclusion Perilabyrinthine drainage of petrous apex cholesterol granulomas may result in hearing preservation or hearing improvement, even in the setting of otic capsule erosion. Patients should be counseled about the potential risk of significant hearing loss.     

Giant cholesterol cysts of the petrous apex]

In connection with their two own cases, the authors deal about the giant cholesterol cysts of the petrous apex. The lesions which are to be differentiated from epidermoid cysts are cholesterol granulomas. Their petrous apex location explains their characteristic large appearance. As each cholesterol granuloma, they occur when a bony cell is obstructed. This chronic obstruction induces mucosal edema then bleedings which lead to the formation and, by the lack of drainage, to the accumulation of cholesterol crystals. These crystals initiate a non specific reaction to foreign bodies, a granuloma, which also can bleed. Thus, a continuous cycle perpetuates the growth of the lesion. This lesion, when it is localized in the petrous apex, can reach a big size before the appearance of some signs. Usually, these are otologic (sensorineural hearing loss, tinnitus, vertigo) and/or cranial nerve palsies (V, VI, VII). C.T. scan (well defined, sharply marginated bony expansible lesion with isodense to the brain central part) and M.R.I. (central region of increased intensity on both T1 and T2 weighted images and peripheral rim of markedly decreased signal intensity in all instances) features are characteristic enough to allow diagnose with other petrous apex lesions (cholesteatoma, mucocele, epithelial cyst, histiocytosis X, ...). Surgical treatment must try to evacuate and to aerate the cavity or perhaps to obliterate it with fatty pieces in order to prevent the recurrence.     

A limited anterior petrosectomy with preoperative embolization of the inferior petrosal sinus for ventral brainstem tumor removal

BACKGROUND: The present study describes the use of a limited subtemporal extradural anterior petrosectomy with preoperative embolization of the inferior petrosal sinus for the management of tumors located behind the clivus and ventral to the brainstem. Details of the procedure and its application in five cases are presented. METHODS: This procedure consists of using the extradural route to approach the upper side of the petrosal pyramid so that it can be drilled medially, and to resect the apex to come out into the posterior fossa. This route gives a petrosectomy just medial to the horizontal segment of the petrous carotid artery in front of the cochlea. It goes around the labyrinthine mass and the internal auditory canal from above to expose the posterior fossa dura between the two petrosal sinuses. The dural opening exposes the ventral aspect of the pons from the trigeminal nerve to the origin of the abducens nerve, ventral to the facial nerve. Preoperative embolization of the inferior petrosal sinus allows its intraoperative section for a wider exposure along the lower clivus. This approach can easily be combined with an intradural approach to provide additional exposure above the trigeminal nerve. Patients who underwent this procedure had prepontine cisternal chordoma or epidermoid cyst of the petroclival region. RESULTS: One patient experienced a cranial nerve deficit as a direct result of the surgical procedure (VIth nerve palsy requiring surgery) but no other patient has had permanent neuromuscular compromise. Complications consisted of a wound infection in one case. Tumor removal was total in three cases and partial in two cases. CONCLUSION: Quite easy to master, the anterior petrosectomy with preoperative embolization of the inferior petrosal sinus is a time-conserving approach giving one of the best routes to reach the ventral brainstem while working in front of the cranial nerves and preserving hearing.     

Petrous apex cholesterol granuloma aeration: does it matter?

OBJECTIVE: To determine whether aeration of surgically treated petrous apex cholesterol granulomas (PA CG) has any correlation with resolution of symptoms. STUDY DESIGN: Retrospective chart review. SUBJECTS: Twenty-six patients with a petrous apex cholesterol granuloma during a 16-year period were reviewed. RESULTS: Seventeen of 26 (65%) patients underwent surgical intervention. Preoperative symptoms included headache, facial weakness/twitching or numbness, vertigo, hearing loss, vision changes, and tinnitus. Postoperative symptoms resolved in 9 of the 16 patients (56%). Three patients had a postoperative headache. Facial nerve dysfunction persisted or recurred in four patients. One patient was lost to follow-up. Thirteen patients had postoperative imaging. All 13 (100%) patients demonstrated stable or increased size of PA CG with no evidence of aeration. Revision surgery was performed in four patients (25%) for facial nerve symptoms or persistent headaches. CONCLUSION: The extent of PA CG aeration on postoperative imaging had no correlation to symptom resolution or cyst enlargement. Revision surgery should not depend on imaging alone but primarily on patient symptoms and physical exam.     

Petrous Apex Cholesterol Granuloma: Importance of Pedicled Nasoseptal Flap in Addition to Silicone T-tube for Prevention of Occlusion of Drainage Route in Transsphenoidal Approach—A Technical Note

Recently, petrous apex cholesterol granulomas (CGs) have been treated via the endoscopic endonasal transsphenoidal approach (EEA) using a silicone tube, to prevent drainage route occlusion. Occlusion of the drainage route has led to problems with recurrence. The aim of this report is to describe the use of a surgical technique to prevent drainage route occlusion. In surgical technique, the posterolateral wall of the sphenoid sinus was opened by EEA. After cyst debridement, a vascularized nasoseptal flap with a width of approximately 4 cm was inserted into the lumen with a silicone T-tube with a diameter of 7 mm. This technique was used in two patients: the first patient during the second operation after recurrence following occlusion of the drainage route, and the second patient during the first operation. Opening of the cyst wall was confirmed endoscopically in both patients 12–24 months after surgery, even after removal of the T-tube. In conclusion, the use of a pedicled nasoseptal flap with a silicone tube is useful to prevent CG recurrence, by paranasal cavitization of the cystic cavity.     

Extradural neuromas at the petrous apex: report of two cases

OBJECTIVE AND IMPORTANCE: Two rare cases of middle cranial fossa neuroma located in the epidural space at the petrous apex are reported. CLINICAL PRESENTATION: Two women, aged 58 and 49 years, were admitted to our hospital with diagnoses of cavernous sinus tumor. Analysis of preoperative computed tomography scans showed bone erosion of the petrous apex, and magnetic resonance imaging demonstrated the presence of an extradural mass located along the course of the petrous internal carotid artery in both patients. INTERVENTION: The tumor was completely removed in one patient and partially removed in the other by use of the epidural middle cranial fossa transpetrosal approach. In both patients, histological examination of tumor specimens revealed neuroma. CONCLUSION: Because surgical exploration revealed that these epidural tumors adhered tightly to the internal carotid artery, and because they had no relationship to the trigeminal nerve, facial nerve, or proximal greater superficial petrosal nerve, in our opinion, these tumors originated from the distal portion of the greater superficial petrosal nerve or the deep petrosal nerve. These neuromas were mainly found in a site under the cavernous sinus at the petrous apex, a location not previously reported.     

En bloc resection of the temporal bone by the lateral approach in carcinoma of the middle ear associated with skull base infiltration with reference to the resection of the petrous apex

En bloc resection of the temporal bone was performed by the lateral approach on two patients with carcinoma of the middle ear, which was associated with destruction in the temporal bone and tumor infiltration of the cranial base. In one of the patients, the petrous apex was resected along with the temporal bone.En bloc resection on the temporal bone with the petrous apex is believed to be difficult because the internal carotid artery (ICA), cavernous sinus, and the brainstem are adjacent to each other in the petrous apex. However, the intra- and extracranial surgical procedures by this approach allow resection of the temporal bone ranging from the anterior part including the petrous apex to the posterior part including the mastoid process, the dura of the middle and posterior cranial fossae, and the sigmoid sinus, without exposure of the tumor. Special attention should be paid to the procedural points of surgery, such as, exposure of the petrous ICA, bleeding from the petrous sinus, and dural suturing in the vicinity of the apex. With regard to surgical indication, it is important to determine whether tumor infiltration is confined to the temporal bone and the dura of the middle and posterior fossa. If tumor infiltration into the petrous ICA, the dominant side of sigmoid sinus and/or the inferior cranial nerve is observed, then indication for surgery should be determined in a more critical manner.     

Conventional posterior fossa approach for surgery on petroclival meningiomas: a report on an experience with 28 cases

BACKGROUND: This is a report of our experience with 28 cases of select petroclival meningiomas operated by a posterior fossa route encompassing the lateral supracerebellar-infratentorial and retrosigmoid avenues. METHODS: Twenty-eight cases of petroclival meningiomas treated during the period 1991 to 2002 by conventional posterior cranial fossa route are analyzed. The average length of follow-up is 48 months. RESULTS: The maximum diameter of the tumors ranged from 1.8 to 6.8 cm (mean, 4.0 cm). Five tumors extended up to or beyond the contralateral petroclival junction. Basilar artery was at least partially encased in 9 cases. Gross total tumor resection was achieved in 21 cases and a partial tumor resection was achieved in the remaining 7 cases. Two patients died in the postoperative phase. CONCLUSIONS: Conventional posterior cranial fossa surgery can be suitable for a select group of petroclival meningioma. Apart from other advantages, it provides easy and quick exposure of the tumor without any petrous bone drilling. It also provides a direct and early exposure of the tumor-cranial nerve-brainstem interface facilitating the dissection. The lateral and inferior tumor extensions in relationship to the clivus can be more easily accessed. The site of attachment of the tumor to the dura overlying the posterior face of the petrous apex can be seen directly.     

En Bloc Resection of the Temporal Bone by the Lateral Approach in Carcinoma of the Middle Ear Associated with Skull Base Infiltration with Reference to the Resection of the Petrous Apex

En bloc resection of the temporal bone was performed by the lateral approach on two patients with carcinoma of the middle ear, which was associated with destruction in the temporal bone and tumor infiltration of the cranial base. In one of the patients, the petrous apex was resected along with the temporal bone.

En bloc resection on the temporal bone with the petrous apex is believed to be difficult because the internal carotid artery (ICA), cavernous sinus, and the brainstem are adjacent to each other in the petrous apex. However, the intra- and extracranial surgical procedures by this approach allow resection of the temporal bone ranging from the anterior part including the petrous apex to the posterior part including the mastoid process, the dura of the middle and posterior cranial fossae, and the sigmoid sinus, without exposure of the tumor. Special attention should be paid to the procedural points of surgery, such as, exposure of the petrous ICA, bleeding from the petrous sinus, and dural suturing in the vicinity of the apex. With regard to surgical indication, it is important to determine whether tumor infiltration is confined to the temporal bone and the dura of the middle and posterior fossa. If tumor infiltration into the petrous ICA, the dominant side of sigmoid sinus and/or the inferior cranial nerve is observed, then indication for surgery should be determined in a more critical manner.

     

Endoscopic/Microscopic approach to sphenopetroclival complex: an anatomical study

A dilemma presents itself to the otoneurologist and neurosurgeon when determining the least invasive surgical approach to giant cholesterol cysts (GCC) of the petrous apex of the temporal bone. These lesions can be diagnosed with a fair degree of certainty with imaging studies. Transmastoid and subcochlear approaches may be inadequate to access these lesions, and the transcochlear approach results in the sacrifice of hearing. A minimally invasive, combined microscopic and endoscopic sublabial transsphenoid approach to drain and marsupalize these lesions has been chosen by the authors in those cases that are anatomically possible. The purpose of this article is to establish the feasibility of exenterating anterior petrous apex cells by way of this approach, and to better conceptualize the anatomy of the Spheno-Petro-Clival Complex (SPC). Ten Fresh cadaveric "whole head" specimens were dissected with, endoscopic/microscopic control, through midline, sublabial, transseptal, and transsphenoidal routes to the petrous apex. The three-dimensional relationships of the sphenoid sinus, petrous apex, and the clivus were further demonstrated by dissections of the same specimens from the posterior fossa. Sagittal cut sections were also performed. After confirming the feasibility of this approach by dissections, the technique was adopted for performing drainage of GCC of the petrous apex in clinical cases.     

Endoscopic/Microscopic Approach to Sphenopetroclival Complex: An Anatomical Study

A dilemma presents itself to the otoneurologist and neurosurgeon when determining the least invasive surgical approach to giant cholesterol cysts (GCC) of the petrous apex of the temporal bone. These lesions can be diagnosed with a fair degree of certainty with imaging studies. Transmastoid and subcochlear approaches may be inadequate to access these lesions, and the transcochlear approach results in the sacrifice of hearing. A minimally invasive, combined microscopic and endoscopic sublabial transsphenoid approach to drain and marsupalize these lesions has been chosen by the authors in those cases that are anatomically possible. The purpose of this article is to establish the feasibility of exenterating anterior petrous apex cells by way of this approach, and to better conceptualize the anatomy of the Spheno-Petro-Clival Complex (SPC). Ten Fresh cadaveric “whole head” specimens were dissected with, endoscopic/microscopic control, through midline, sublabial, transseptal, and transsphenoidal routes to the petrous apex. The three-dimensional relationships of the sphenoid sinus, petrous apex, and the clivus were further demonstrated by dissections of the same specimens from the posterior fossa. Sagittal cut sections were also performed. After confirming the feasibility of this approach by dissections, the technique was adopted for performing drainage of GCC of the petrous apex in clinical cases.     

Subcochlear approach for cholesterol granulomas of the inferior petrous apex

Cholesterol granulomas of the petrous apex are drained through two major extralabyrinthine routes: one, along the posterosuperior chain of air cells, and two, along the anteroinferior chain. Procedures that use the posterosuperior chain approach the apex from the sinodural angle, the base of the zygomatic arch, the attic, or through the arch of the superior semicircular canal. Operations that use the anteroinferior chain reach the apex along the internal carotid canal (Ramadier's operation) or by a posterior infralabyrinthine approach between the descending facial nerve and jugular bulb. Inferior petrous apex cholesterol granulomas may be unreachable by any of these routes, and hence the subcochlear route is proposed as an alternative. The subcochlear approach starts in a triangle bounded superiorly by the cochlea, anteriorly by the internal carotid canal and posteriorly by the deep jugular vein. This operation requires lowering the inferior bony canal wall to the level of the "crutch." It provides access to an inferiorly situated cholesterol granuloma, yet preserves hearing. It allows enough room for the placement of a tube drain from the petrous apex to the mastoid. It is particularly useful when a high jugular bulb precludes the use of the posterior infralabyrinthine route.     

Endoscopic Endonasal Management of Recurrent Petrous Apex Cholesterol Granuloma

Introduction Petrous apex cholesterol granulomas (PACGs) are uncommon lesions. Recurrence following transcranial or endonasal approaches to aerate the cyst occurs in up to 60% of cases. We describe the technical nuances pertinent to the endonasal endoscopic management of a recurrent symptomatic PACG and review the literature.Results A 19-year-old woman presented with a recurrent abducens nerve paresis. Four months prior, she underwent an endonasal transsphenoidal surgery (TSS) for drainage of a symptomatic PACG. Current imaging documented recurrence of the right PACG. Transsphenoidal and infrapetrous approaches were performed to obtain a wider bony opening along the petrous apex and drain the cyst. A Doyle splint was inserted into the cyst''s cavity and extended out into the sphenoid sinus, maintaining patency during the healing process. Three months after surgery, the splint was removed endoscopically, allowing visualization of a patent cylindrical communication between both aerated cavities. The patient remains symptom-free and recurrence-free.Conclusion Endoscopic endonasal surgery must be adapted to manage a recurrent PACG. A TSS may not be sufficient. An infrapetrous approach with wider bony opening, extensive removal of the cyst''s anterior wall, and the use of a stent are indicated for the treatment of recurrent PACG and to prevent recurrences.     

Epidermoid tumor originating from the petrous bone: report of two cases

In case 1, the tumor was incidentally found in the right petrous bone, middle cranial fossa and cerebello-pontine angle. T1 weighted MRI demonstrated a low intense mass and T2 weighted imaging demonstrated hyperintensity. Through the subtemporal extradural approach, an epidermoid in the middle cranial fossa was partially removed. Postoperative course was uneventfull but an episode of rhinorrhea occurred 15 months later. Bone-window CT scan disclosed air cells of the petrous bone were exposed to the previous surgical cavity. Using the same approach, an epidermoid was totally removed. With the sealing of the tumor cavity with the vascularized muscle flap, the patient became free from rhinorrhea. Case 2 had complainted of sensory impairment in the left trigeminal nerve distribution, atrophy of the left temporal and masseter muscle, and diplopia. T1 weighted imaging of MRI demonstrated a low-intense mass in the left petrous bone, middle cranial fossa, temporal lobe, and cerebello-pontine angle, and T2 weighted imaging demonstrated hyperintensity. The intradural tumor under the temporal lobe was removed at another hospital. As the diplopia deteriorated 5 years later, the patient was re-introduced to our hospital. At first, the tumor in the cerebello-pontine angle was removed using the left retromastoid lateral suboccipital approach. Later, the tumor in the petrous bone and middle cranial fossa was removed through the left subtemporal extradural approach. With the sealing of the tumor cavity with the vascularized muscle flap, postoperative cerebrospinal fluid leakage was prevented. The epidermoid tumor in the petrous apex is a congenital and rare disease. The obstruction of the petrous air cell and dural defect using the vascularized flap is most important to prevent postoperative cerebrospinal fluid leakage.     

Arachnoid cysts of the posterior fossa

BACKGROUND: The surgical indications and management of posterior fossa arachnoid cysts (AC) are still controversial. Different surgical techniques and management have already been suggested for arachnoid cysts of the posterior fossa. AC involving the posterior fossa and especially the cerebellopontine angle may carry a high surgical morbidity because of the involvement of important neurovascular structures (e.g., brain stem and cranial nerves). Only long-term follow-up will determine the best surgical technique for such lesions. METHODS: Between 1990 and 1996 a total of 12 patients underwent surgery for arachnoid cysts involving the posterior fossa. In seven cases AC were located within the cerebellopontine angle (CPA), in three cases in the CPA with major extension dorsal to the brainstem, and in two cases at the CPA extending into the internal auditory canal. RESULTS: A suboccipital retrosigmoid approach was performed in all patients. Radical resection of the cyst could be accomplished in all but one case. There was no mortality. Major postoperative morbidity was present in one case because of an intraoperative air embolism in the semisitting position and strong adherence of the cyst wall to the surrounding neurovascular structures. Long-term follow-up (mean, 3.3 years) revealed improvement of most preoperative symptoms. CONCLUSION: Open surgery and radical removal of the AC located at the posterior fossa, based on our retrospective analysis, provide very good long-term postoperative results. The suboccipital approach provides a good and safe exposure of vascular structures and cranial nerves in the CPA and allows radical resection of the cyst, reducing the chance of recurrence.