The system of the modified transcochlear approaches to the petroclival area and the prepontine cistern

Between June 1986 and June 1993 46 different tumors (27 extradural and 19 intradural) located in the petroclival area and/or prepontine cistern have been operated on at The Gruppo Otologico Piacenza and the ENT Department of Bergamo, Italy using a modification of the transcochlear approach. Total tumor removal was obtained in all cases. Complications occurred in eight patients. One patient died due to infarction of the brain stem. The system of modified transcochlear approaches conceived for the removal of various intradural and extradural tumors is presented. This approach, together with its modifications, is the major operative access to the central skull base and clivus among a series of lateral approaches described in the literature. The basilar surgical technique (type A) and its modifications (types B, C, D) are described in detail, and five different, illustrative cases are presented. Indications, limits, results, and complications related to the approach are discussed.

Intratemporal hemangiomas involving the facial nerve: diagnosis and management

Intratemporal vascular tumors involving the facial nerve are rare benign lesions. Because of their variable clinical features, they are often misdiagnosed preoperatively. This study presents a series of 21 patients with such lesions managed from 1977 to 1994. Facial nerve dysfunction was the most common complaint, present in 60% of the cases, followed by hearing loss, present in 40% of cases. High-resolution computed tomography, magnetic resonance imaging with gadolinium, and a high index of clinical suspicion is required for preoperative diagnosis of these lesions. Early surgical resection of these tumors permits acceptable return of facial nerve function in many patients.

Surgical anatomy of the extended middle cranial fossa approach

The extended middle cranial fossa approach includes removal of the petrous bone from its subtemporal surface in order to expose widely the internal auditory canal and the posterior fossa dura around its porus while preserving all the important and closely related anatomical structures. We have dissected 25 temporal bones and five fresh cadavers in order to define the limits of this approach. Measurements were obtained between the different structures to find reliable angles and distances that could guide working in this area. A new method of identification of the internal auditory canal is discussed based on the measurements taken.The results of the present work showed wide variations in the different structures. The arcuate eminence was coincident with the superior semicircular canal in only 48% of bones. Dehiscence of the geniculate ganglion and of the internal carotid artery was noted in 16% and 20% of specimens, respectively. The angles measured between the different structures showed great variations. However, the angle between the internal auditory canal and superior petrosal sinus was constant. Though the extended middle cranial fossa is a versatile approach, it affords a limited access to the cerebellopontine angle. A thorough understanding of the complex and variable anatomy of this area is necessary should this approach be utilized.

Posterior fossa meningioma: surgical strategy

Posterior fossa meningioma is the second most common tumor in the cerebellopontine angle. It has a higher rate of postoperative morbidity and mortality compared to acoustic neuroma. Forty posterior fossa meningioma patients managed in our centers were reviewed. Thirty-nine patients were managed surgically with 42 surgical procedures. The approaches used were the translabyrinthine approach in 18 patients (43%), the modified transcochlear in 11 cases (26%), the petro-occipital transsigmoid in 5 cases (12%), the suboccipital in 4 cases (10%), the petro-occipital trassigmoid transcervical in 2 cases (5%), the petro-occipital transsigmoid transtentorial in 1 case (2%), and a subtemporal transtentorial for another case (2%). Facial nerve anatomical integrity was preserved in 87% of procedures but was interrupted in 5 cases, with 4 of the latter subsequently repaired. Total tumor removal was accomplished in 38 cases. A second-stage total tumor removal is planned for the remaining case. There was only one case of perioperative death and no cases of radiological recurrence so far.

Combined endovascular-surgical management of the internal carotid artery in complex tympanojugular paragangliomas

The infratemporal fossa approach described by Fisch overcame most of the factors that had previously prevented the total removal of tympanojugular paragangliomas (TJP). The remaining problem has been infiltration of the internal carotid artery (ICA) for which there has been no entirely satisfactory solution. At the least, severe encasement risks the possibility of an arterial rupture at surgery. In order to reduce this risk, preoperative endovascular interventions have been employed-mainly balloon occlusion, with or without arterial bypass. Recently, intra-arterial stents to reinforce the encased segment of the ICA have been introduced. This study evaluates our experience with 20 patients affected by TJP in which the ICA has been subjected to preoperative interventions. Ten patients underwent a preoperative balloon occlusion and the other 10 patients had their ICAs reinforced with stents. Problems that arose during embolization necessitated that one patient with a stent required ligation of their ICA. No other problems were encountered during endovascular treatment or surgical resection. In one patient with a stent, it was impossible to establish a cleavage plane between their recurrent tumour and the ICA. These early results are encouraging and suggest that intra-arterial stents have a part to play in the surgical management of large TJPs.

Meningiomas intrinsic to the geniculate ganglion

Geniculate ganglion meningiomas are extremely rare lesions-only 14 cases have been reported in the literature. Two new cases of these tumors are described. On computed tomography and magnetic resonance imaging, both lesions appeared centered on the area of the geniculate ganglion, extending to the tympanic cleft and eroding the middle cranial fossa floor. The first case was treated through a middle cranial fossa approach. Because the tumor was so large in the second case, a subtotal petrosectomy was used. The authors review the literature to clarify the clinical and radiological characteristics of these tumors and their surgical treatment.

Decision making in acoustic neuroma management: the only hearing ear

Patients with acoustic neuroma in their only hearing ear are not frequently seen in clinical practice. Managing this group of patients is a challenge to both patient and surgeon. In this study we report on five cases of acoustic neuroma in an only hearing ear. Our decision for nonsurgical management of those patients with regular follow-up using auditory brainstem responses and magnetic resonance imaging is discussed. Other management options currently available are considered as well.

Fast-growing vestibular schwannoma

A case of a Jehovah's witness affected by an intracanalicular vestibular schwannoma with an extremely fast growth rate is presented. Nine months after presentation, the tumor reached 23 mm in the cerebellopontine angle. A partial removal through a retrosigmoid approach was planned. Because of the presence of a dominant high jugular bulb masquering the internal auditory canal, the intracanalicular portion of the tumor was left in place. The residual tumor grew 12 mm in 2 months. Even after a gross total removal through a middle cranial fossa approach, the tumor recurred, reaching the size of 30 mm in 17 months. A modified transcochlear approach was then performed, and the patient was free of disease at the last radiologic follow-up, 8 months after the surgery. We illustrate our strategy in treating this aggressive benign lesion with unusual behavior.

CNAP To Predict Functional Cochlear Nerve Preservation in NF-2: Cochlear Implant or Auditory Brainstem Implant

The ideal management of bilateral vestibular schwannomas (VSs) involves complete tumor resection with preservation of hearing in at least one ear. While auditory brainstem implants (ABIs) have represented a significant advance in the management of neurofibromatosis type 2 (NF-2) patients, hearing rehabilitation is far from ideal. More recently, cochlear implantation has been used in selected cases of NF-2, following tumor removal, where the patient is left with bilateral profound hearing loss but with anatomical continuity of the cochlear nerve. In selected cases, cochlear implant (CI) has given superior results to ABI. The Gruppo Otologico experience in managing NF-2 patients consists of 29 patients treated between December 1996 and December 2007 out of a total of 1723 VSs. Thirty-nine tumors have been removed, with 10 patients having had bilateral tumor removed. Ten ABIs have been implanted and 5 CIs placed. We present a case that illustrates some of the difficulties encountered in the management of NF-2 VS and provides a basis for discussion of a technique to assist intraoperative decision-making to achieve optimal hearing rehabilitation. In the setting of a negative fast auditory brainstem response (ABR), but preserved cochlear nerve action potential (CNAP), the option of a CI can be considered. However, where the fast ABR and the morphology and amplitude of the CNAP are significantly degraded at the brainstem, the placement of an ABI should be strongly considered at the time of tumor removal. This technique must be further evaluated, but it represents an adjunct in this difficult area for the neurotologist. To this end we propose that a multicenter trial be undertaken to further elucidate the role of intraoperative monitoring to determine the functional preservation of the cochlear nerve.

A posterolateral approach to the skull base: the petro-occipital transsigmoid approach

This posterolateral approach is directed to the petro-occipital skull base and is a combination of a suboccipital craniotomy, with an inferoposterior petrosectomy. The areas exposed are the jugular foramen, occipital condyle, lower clivus to the midline, petrous apex, tympanic cavity, the vertical portion of the intrapetrous carotid artery below the level of the eustachian tube, cerebellopontine angle, the jugulocarotid space in the upper neck. We evaluated 45 cases as follows: 13 chemodectomas, 14 lower cranial nerve schwannomas, 10 meningiomas, and 8 other lesions. The approach is indicated for extra-, intra-, and transdural lesions of the jugular foramen area. The transdural lesions could be extirpated in a single procedure without cerebrospinal fluid leak. This, in addition to preservation of the facial nerve, middle and inner ear functions, constituted the main advantages of this approach. Lower cranial nerve deficit formed the major morbidity in the present series and is still an unsolved problem in such cases.

Facial nerve function after vestibular schwannoma surgery

OBJECT

The object of this study was to evaluate long-term postoperative facial nerve (FN) function in patients undergoing vestibular schwannoma (VS) surgery.

METHODS

The authors retrospectively reviewed the clinical course of patients affected by isolated VSs with normal preoperative FN function, with no previous surgical or radiotherapeutic treatment, and who underwent surgery between 1987 and 2007. Facial nerve function was clinically evaluated according to the House-Brackmann (HB) scale. The minimum postoperative follow-up was 12 months.

RESULTS

Among the 1550 patients surgically treated at the authors' center, 1151 matched inclusion criteria for the present study. The FN was anatomically interrupted in 48 cases (4.2%), and 51 patients (4.4%) underwent subtotal tumor removal and were considered separately. Among the 1052 patients with anatomically preserved FNs and total tumor removal, 684 (65%) enjoyed postoperative HB Grade I or II and 309 (29.4%) enjoyed Grade III, with the remaining 59 cases (5.6%) suffering unsatisfactory results (HB Grades IV-VI). As expected, FN function results deteriorated in cases of larger tumors.

CONCLUSIONS

The main factor influencing postoperative FN function was tumor size. Although there was a progressive deterioration in FN function outcome in relation to tumor size, a cutoff point between satisfactory and unsatisfactory results could be identified at around 2 cm in maximum extrameatal tumor diameter, with the "optimal size" for surgery identified at < 1 cm. This finding emphasizes the importance of an early diagnosis and should be kept in mind when selecting the correct timing for VS removal. For small lesions, the results following a middle cranial fossa approach were significantly worse as compared with those following the translabyrinthine and retrosigmoidretrolabyrinthine approaches.

Intermediate nerve schwannoma: a rare tumour

The intermediate nerve (IN), also called the nerve of Wrisberg, is a relatively small nerve with a variable anatomical course. Currently, this nerve is not addressed well in the pertinent literature. Pre-operative diagnosis of IN tumours is clinically challenging due to the lack of related symptoms. Symptoms are typically caused by the functional deterioration of neighbouring anatomical structures. In this report, we describe a patient with a schwannoma that arose at the porus acusticus of the internal auditory canal; during surgery, this proved to originate from the IN. We discuss our findings in the context of previously reported cases of IN schwannomas and analyse the vague characteristics and symptoms of this rare tumour.

Management of complex cases of petrous bone cholesteatoma

OBJECTIVES

In a retrospective analysis of a quaternary referral neuro-otologic private practice, we identify complex cases of petrous bone cholesteatoma (i.e., cases with encasement of vital structures such as the internal carotid artery, jugular bulb, and sigmoid sinus, with further extension to the clivus, sphenoid sinus, or rhinopharynx), review surgical approaches and techniques of management of vital structures, and propose the ideal surgical management.

METHODS

We performed a retrospective case study of 130 cases of petrous bone cholesteatoma submitted to surgery between 1979 and 2009 to identify the complex cases and their classification, approach used, outcomes, and recurrences.

RESULTS

Of 130 cases. 13 were complex. Facial palsy was the presenting feature in 11 cases, 7 of which presented with grade VI palsy. A long duration of facial palsy (more than 3 years) was seen in 5 cases. Clival involvement was seen in 6 cases; 1 case extended to the sphenoid sinus, and 1 to the rhinopharynx. The internal carotid artery was encased in 11 cases in the vertical and the horizontal parts. The jugular bulb was involved in 7 cases. Modified transcochlear approaches or infratemporal fossa approaches were used in all cases. There were no recurrences.

CONCLUSIONS

Classification is fundamental to choosing the right surgical approach. Transotic and modified transcochlear approaches hold the key to treating complex cases. Infratemporal fossa approach type B has to be used for extension into the clivus, sphenoid sinus, or rhinopharynx. Internal carotid artery, jugular bulb, and sigmoid sinus involvement should be identified before operation.

Petrous bone cholesteatoma: classification, management and review of the literature

OBJECTIVE

To discuss the classification of petrous bone cholesteatoma (PBC) and add a subclassification; to review the existing literature and to propose the ideal surgical management of PBC based upon the experience of the largest series published in the literature until now.

STUDY DESIGN

Retrospective analysis.

SETTING

Quaternary referral neuro-otologic private practice.

MATERIALS AND METHODS

The data of 129 patients who underwent surgery for PBC between 1979 and 2008 were analyzed with respect to the classification, type of the approach used, facial nerve lesion and its management, recurrences and outcome.

RESULTS

Out of the 129 PBC cases 64 were supralabyrinthine, 9 infralabyrinthine, 7 infralabyrinthine-apical, 48 massive and 1 apical. The facial nerve was involved in 95% of the cases. Hearing could not be preserved in 82% of the cases due to the extent of the lesions and the surgical approaches used. The internal carotid artery, jugular bulb and the lower cranial nerves were infrequently involved, but demanded careful identification and meticulous care to avoid complications. Obliteration of the cavities provided a safe solution for protection of the exposed dura and the vital neurovascular structures. Recurrences were observed in 5 cases.

CONCLUSION

The classification of PBC is fundamental to choose the appropriate surgical approach; the facial nerve is involved in almost all the cases, radical removal takes priority over hearing preservation and cavity obliteration is important to protect the vital neurovascular structures which may be exposed.

Middle ear and mastoid glomus tumors (glomus tympanicum): an algorithm for the surgical management

OBJECTIVE

Glomus tumors are slow-growing benign lesions and represent the most common primary neoplasms of the middle ear. The objective of the present study is to report our surgical strategy in the management of glomus tympanicum tumors.

METHODS

Between December 1988 and July 2008, 68 patients with histologically confirmed glomus tympanicum tumor underwent surgical treatment. The follow-up of the series ranged from 6 to 194 months (mean, 33.4 months).

RESULTS

Distribution of tumors according to Fisch and Mattox classification was as follows: type A, 44 cases (64.7%); type B, 24 cases (35.3%). All of the 44 Class A tumors were safely removed via either a stapedectomy-type transcanal approach or a retroauricolar-transcanal approach. Five patients with Class B tumors were operated on through a transmastoid approach. Nineteen patients with larger Class B tumors underwent a subtotal petrosectomy with blind sac closure of the external auditory canal and middle ear obliteration. Gross total tumor removal was achieved in all 68 cases. In one case (1.4%) there was recurrence after 9 years, for which the patient was re-operated. No residual/recurrence has been detected on computed tomography in the rest of the patients.

CONCLUSION

Surgical excision of glomus tympanicum tumors is a safe procedure, allowing total tumor removal with minimal morbidity, a low recurrence rate, and a low complication rate.

Otoneurological management of petrous apex cholesterol granuloma

OBJECTIVE

The aim of the study is to review the management of petrous apex cholesterol granuloma. The surgical approaches for drainage or total removal and the wait and see policy were analyzed, and outcomes were evaluated.

METHODS

Retrospective charts of 27 patients managed for petrous apex cholesterol granuloma with a minimum follow-up of 12 months were analyzed in a quartenary skull base center. Presenting symptoms and signs were recorded, and radiologic imaging was evaluated. Management options included wait and see policy and surgery by several approaches.

RESULTS

The mean age of patients affected by the lesion was 38.8 years. The mean follow-up was 56.7 months. Patients complained of hearing loss, vertigo, tinnitus, diplopia, hemifacial spasm, trigeminal neuralgia, and facial paresthesia. Twelve patients were managed by wait and see policy, and in this category, only one lesion showed growth during the follow-up. Depending upon size and location, 15 patients were surgically treated by infralabyrinthine approach (9 patients), infratemporal type B approach (3 patients), combined infratemporal type B transotic approach (2 patients), and transotic approach (1 patient). One recurrence was recorded during the follow-up.

CONCLUSIONS

Radiologic evaluation is required for diagnosis and management. Patients with good hearing can be treated by infralabyrinthine approach. Infratemporal fossa type B approach is advocated in patients with extensive disease and internal carotid artery involvement. Wait and see policy is recommended for asymptomatic cases. Drainage and permanent ventilation are the goals of treatment. Complete removal is indicated in selected cases where placement of drainage tube is not feasible.

Intracranial facial nerve grafting after removal of vestibular schwannoma

OBJECTIVE

The objectives of this study were to evaluate outcomes from facial nerve (FN) cable grafting in patients who experienced FN transection during vestibular schwannoma removal and to compare the FN outcomes of patients who underwent FN grafting by using fibrin glue with those of patients who underwent FN grafting by using microsuture.

MATERIAL AND METHODS

We retrospectively evaluated a series of 33 patients in whom FN grafting was achieved either by using microsuture (8 cases) or fibrin glue (25 cases). Immediate repair of the FN was performed in all cases at the time of initial resection. The patients FN function was assessed preoperatively, in the immediate postoperative period, and at 3, 6, 9, and 12 months or more postoperatively using the House-Brackmann grading system. All patients had at least 1-year follow-up.

RESULTS

At 12 months, a House-Brackmann grade III was achieved in 75% of those who underwent cable nerve graft interposition by using microsuture and in 76% of those who underwent cable nerve graft interposition by using fibrin glue. Analysis of final FN function outcomes demonstrated no statistically significant difference in FN outcomes between the 2 groups (P = .891, Mann-Whitney U test; P = .1, Fisher exact test).

CONCLUSIONS

The functional results after FN cable grafting by using fibrin glue exclusively were equivalent to those obtained with microsuture. However, the technique of FN repair by means of fibrin glue is technically simple, less time-consuming, and imparts less trauma on the nerve than does the traditional suture method.

[Emotional aspects and quality of life of patients after acoustic neuroma surgery]

Acoustic neuromas are rare lesions arising in the internal auditory canal (IAC) and extending in the posterior cranial fossa. Surgical removal is the treatment of choice; peri and postoperative complications are directly related to the size of the tumour. Some Authors think the surgical treatment and related temporary or permanent neurological deficits could change the QoL and the psychological status.

PURPOSE

The aim of this analysis is to ascertain if the surgical procedure could significantly worsen the QoL of this population 12 months after the discharge from surgical department.

METHODS

By using a questionnaires of Quality of Life aims to evaluate the impact that the disease and the surgical procedure have on this population.

SUBJECTS

We have evaluated a sample of 150 subjects one year after the surgical removal of a acoustic neuroma. Data have been collected through questionnaires the Whoqol-Brief, the BDI, the STAI Y1 and Y2 and specific item to assess effects of postoperative dysfunctions.

RESULTS

Data reveal a negative effect on QoL, 94% of the subjects show lower score at Whoquol-Brief and in anxiety with scores higher than normative score sample (state-anxiety (t = 5.602 p = .000; trait-anxiety: t = 4.354 p = .000). Higher incidence of depressive disorders have not been found.

CONCLUSION

Psychological support to subjects after discharge from acoustic neuroma surgical removal should be tailored to improve quality of life and for a better management of anxiety.