Extensive Skull Base Approaches Research Articles

Surgical Management of Large (≥3 cm) Trigeminal Schwannomas: Functional Outcomes and Approach Selection in Multicompartmental Schwannomas.

Introduction Trigeminal schwannoma surgery has shown a remarkable improvement in functional recovery and tumor resection. In the era of radiosurgery, these outcomes need to be characterized for tumors which are outside the realm of being treated with radiosurgery. We present a series of trigeminal schwannomas larger than 3 cm, surgical approaches used, and outcomes with an emphasis on functional recovery in a high-volume center with radiosurgery facilities. Method All consecutive cases of trigeminal schwannoma from January 2012 to May 2021 which were more than 3 cm in size and underwent microsurgery were included in this series. The surgical approach, neurological outcomes, and extent of resection were defined objectively with pre/postoperative magnetic resonance imaging. Results A total of 83 such cases (>3 cm) were found, with cranial nerve symptoms (5th most common) being the commonest. Twenty three percent cases had blindness due to secondary optic atrophy and eighteen percent had long tract motor symptoms signifying the tumor burden in our series. Radiological gross total excision was achieved in 75.9% cases. Conclusion Large-volume schwannomas present with cranial nerve involvement and may need extensive skull base approaches. Functional outcomes need to be prioritized and can be achieved albeit with lesser gross resection rates. Hearing and facial preservation in addition to relief of trigeminal symptoms should be the goal of resection with minimal additional morbidity.

Is Olfactory Function Affected by Endoscopic Transsphenoidal Skull Base Surgery?

Is Olfactory Function Affected by Endoscopic Transsphenoidal Skull Base Surgery?

The extended pterional approach for midline anterior skull base meningiomas

Background: Various surgical approaches for the management of midline anterior skull base meningiomas exist in the literature. The main surgeon target is proper selection the appropriate approach that achieves total removal of the lesion without causing morbidity or mortality and facilitates safe effective removal of the tumour.
 Objectives: To evaluate the role of the extended pterional approach for excision of midline anterior skull base meningiomas as regarding the effectiveness, extent of resection and surgical outcome.
 Patients and methods: This retrospective study involved 23 cases with midline anterior skull base meningiomas resected through the extended pterional approach. Patients' clinical data, operative notes, imaging studies and clinical follow-up data were analyzed and evaluated.
 Results: Tumors studied were 9 olfactory groove meningiomas, 8 tuberculum Sellae meningiomas, 4 planum sphenoidale meningiomas and 2 diaphragma sellae meningiomas. Gross total resection tumour excision in 15 cases (64.5%), subtotal excision in 5 cases (21.5%) and partial excision in 3 cases (14%). Complications were diabetes insipidus (2 cases 8.6%), CSF rhinorrhea (3 cases 12.9%) and visual deterioration (3 cases 12.9%). We had two cases of mortality.
 Conclusion: The extended pterional approach allows safe and effective removal of midline anterior skull base meningiomas. It expands the exposure offered by the classic pterional approach and minimizing the necessity for applying fixed brain retraction with good cosmetic outcome and less approach-related morbidities in comparison with the extensive skull base approaches.

Surgical challenges and outcome of endoscopic endonasal approaches in the management of recurrent pituitary adenomas

Background: Various surgical approaches for the management of midline anterior skull base meningiomas exist in the literature. The main surgeon target is proper selection the appropriate approach that achieves total removal of the lesion without causing morbidity or mortality and facilitates safe effective removal of the tumor.
 Objectives: To evaluate the role of the extended pterional approach for excision of midline anterior skull base meningiomas as regard the effectiveness, extent of resection and surgical outcome.
 Patients and methods: This retrospective study involved 23 cases with midline anterior skull base meningiomas resected through the extended pterional approach. Patients' clinical data, operative notes, imaging studies and clinical follow-up data were analyzed and evaluated.
 Results: Tumors studied were 9 olfactory groove meningiomas, 8 tuberculum Sellae meningiomas, 4 planum sphenoidale meningiomas and 2 diaphragma sellae meningiomas. Gross total resection tumor excision in 15 cases (64.5%), subtotal excision in 5 cases (21.5%) and partial excision in 3 cases (14%). Complications were diabetes insipidus (2 cases 8.6%), CSF rhinorrhea (3 cases 12.9%) and visual deterioration (3 cases 12.9%). We had two cases of mortality.
 Conclusion: The extended pterional approach allows safe and effective removal of midline anterior skull base meningiomas. It expands the exposure offered by the classic pterional approach and minimizing the necessity for applying fixed brain retraction with good cosmetic outcome and less approach related morbidities in comparison with the extensive skull base approaches.

Versatility of sub-occipital approach for foramen magnum meningiomas: a single centre experience.

Foramen magnum meningiomas (FMM) represent a challenge for neurosurgeons. Multiple surgical strategies have been reported to treat these lesions in their variable location. Contemporary technical innovations allow the utilization of common sub-occipital craniotomy to treat ventrally, ventro-laterally and dorsally located FMMs. We present our technique and experience. From November 2004 to November 2015, we treated 14 patients with FMM at the Department of Neurosurgery of the Santa Maria delle Grazie Hospital in Pozzuoli, Naples, Italy. There were 10 females and 4 males, with a mean age of 64.5 years (range, 55-77 years). All patients had high field magnetic resonance imaging (MRI) with contrast enhancement preoperatively, which led to the radiological diagnosis. A sub-occipital craniotomy was performed in all patients as well as the removal of the posterior arch of C1. Partial removal of C2 was necessary in 2 patients. Neck pain was the most common symptom of presentation. Paraparesis was present in patients in 3 patients. Upper limbs dysesthesia or pain existed in 3 cases. Thirty days after surgery neck pain and dysesthesia decreased in all patients affected. Neurological improvement was observed in 2 patients affected by weakness in lower limbs at 6 months follow up. Paraparesis was unchanged in 1 patient. Two patients presented transient worsening after surgery. Transient dysphagia occurred in one case and postoperative hemorrhage with subsequent surgery in another patient. We had no postoperative mortality. FMM surgery should be tailored to the lesion at hand as in most instances it is possible to avoid the use of extensive skull base approaches.

Long-term follow-up after endoscopic trans-sphenoidal surgery or initial observation in clivus chordomas.

Resection of clivus chordomas through extensive skull base approaches is associated with high mortality and morbidity even in experienced hands. We report our experience with endoscopic trans-sphenoidal surgery, or a "wait-and-scan" strategy in selected patients. Ten patients were diagnosed with clivus chordomas during an 8-year period. Six patients underwent primary treatment with endoscopic trans-sphenoidal surgery, followed by adjuvant proton-beam therapy in three of these patients. Four patients with minor symptoms were followed-up untreated. Mean follow-up was 91months. Of the six patients operated on, total or gross total resection was achieved in four, partial resection in one and biopsy was taken in one. Preoperative cranial neuropathies resolved in three out of five patients, and no new cranial nerve palsies were encountered. Postoperative cerebrospinal fluid leak occurred in one patient. Four patients were initially followed-up without any treatment, and three of these have remained stable without tumour progression for a mean of 94months. Due to a slow, though progressive growth of tumour, one patient was operated on after 80months of initial observation. The natural course of clivus chordomas has yet to be defined. The endoscopic trans-sphenoidal approach is a valid, minimally invasive alternative for the treatment of clival chordomas, and in selected patients a "wait and scan" strategy can be considered. Our long-term results show low mortality and good functional outcome. An endonasal endoscopic trans-sphenoidal approach should be a principal part of the armamentarium of surgeons treating clivus chordomas.

The suboccipital midline approach to foramen magnum meningiomas.

Anterior and anterolateral meningiomas of the foramen magnum (FM) can be resected either through extensive skull base approaches or through the classical suboccipital midline approach with limited bone removal. This paper describes the suboccipital midline approach focusing on some peculiar technical features that serve to achieve the necessary space for safe resection of these challenging tumors. In our experience, by adopting appropriate strategies to gain space (some of them natural, others acquired) the suboccipital midline approach can achieve the safe resection of anterior and anterolateral FM meningiomas in the majority of cases.

Retrosigmoid Intradural Inframeatal Approach

Surgery of lesions of the petrous apex involving the inframeatal/infralabyrinthine area is challenging and related to a high risk of complications. Various extensive skull-base approaches have been used. To present and evaluate our experience with a new hearing-preserving extension of the retrosigmoid approach to the inframeatal/infralabyrinthine area. The approach was used in 3 patients harboring lesions in the petrous apex with variable extension in the inframeatal/infralabyrinthine region. The surgical accessibility of the lesions offered by the approach, the completeness of tumor removal, and the outcome, in particular, the functional outcome and complication rate, were assessed. The tumor could be resected from the target area in all cases. No approach-related complications occurred. Serviceable hearing and normal facial nerve functions were preserved in all cases. Our initial experience with the retrosigmoid inframeatal approach showed that it provides sufficient access to the area and offers the possibility of complete tumor removal. It allows for hearing and facial nerve functional preservation. The approach is safe and related to a very low complication rate.

Neurosurgical Strategies and Operative Results in the Treatment of Tumors of or Extending to the Petrous Apex

Tumors originating from or involving the petrous apex are considered to be an operative challenge due to their deep location and close relationship to critical neural and vascular structures. Extensive skull base approaches have been developed to deal with these lesions. The purpose of this study is to review an institutional series of 57 petrous apex tumors, to report our operative experiences and to address the usefulness and limits of standard approaches. 57 patients (22 men, 35 women) with petrous apex tumors were treated microsurgically. We analyzed the type of surgical approach, histological diagnoses, pre- and postoperative clinical findings, diagnostic imaging and surgery-associated complications. According to the location and its predominant extension, a retromastoid approach (n=27), subtemporal approach (n=18), subtemporal/anterosigmoid approach (n=5), transnasal-transsphenoidal approach (n=2), pterional approach (n=2) or a subtemporal/retrosigmoid approach, biphasic approach (subtemporal and pterional), transmastoidal approach (n=1 each) was chosen. In the majority of cases, histological analysis revealed a meningeoma (n=31) or neurinoma (n=7). A total tumor resection was accomplished in 37 patients (64.9%). New permanent neurological deficits, mainly cranial nerve palsies, were found in 18 (31.6%), transient deficits in 5 patients (9.6%). Postoperative improvements of neurological deficits were observed in 17 patients (29.8%), and the neurological status remained unchanged in 17 patients (32.7%). Complete resection of petrous apex tumors using standard neurosurgical approaches without permanent surgery-associated neurological deficits is achievable in the majority of cases.

Combined Microsurgical and Endoscopic Resection of Extensive Suprasellar and Prepontine Epidermoid Tumors

Introduction: Epidermoid tumors often grow around critical neurovascular structures and may adhere firmly to them. Nevertheless, maximal resection is required to reduce the recurrence. Before 2001, we selected extensive skull base approaches. After 2001, we changed our strategy to select less invasive approaches. In this presentation, we discuss the usefulness of combined microsurgical and endoscopic resection for epidermoid tumors.

Trans-zygomatic middle cranial fossa approach to access lesions around the cavernous sinus and anterior parahippocampus: a minimally invasive skull base approach

Exposure of the cavernous sinus or anterior parahippocampus often involves a wide exposure of the temporal lobe and mobilization of the temporalis muscle associated with temporal lobe retraction. The authors present a cadaveric study to illustrate the feasibility, advantages and landmarks necessary to perform a trans-zygomatic middle fossa approach to lesions around the cavernous sinus and anterior parahippocampus. The authors performed bilateral trans-zygomatic middle fossae exposures to reach the cavernous sinus and parahippocampus in five cadavers (10 sides). We assessed the morbidity associated with this procedure and compared the indications, advantages, and disadvantages of this method versus more extensive skull base approaches. A vertical linear incision along the middle portion of the zygomatic arch was extended one finger breadth inferior to the inferior edge of the zygomatic arch. Careful dissection inferior to the arch allowed preservation of facial nerve branches. A zygomatic osteotomy was followed via a linear incision through the temporalis muscle and exposure of the middle cranial fossa floor. A craniotomy along the inferolateral temporal bone and middle fossa floor allowed extradural dissection along the middle fossa floor and exposure of the cavernous sinus including all three divisions of the trigeminal nerve. Intradural inspection demonstrated adequate exposure of the parahippocampus. Exposure of the latter required minimal or no retraction of the temporal lobe. The trans-zygomatic middle fossa approach is a simplified skull base exposure using a linear incision, which may avoid the invasivity of more extensive skull base approaches while providing an adequate corridor for resection of cavernous sinus and parahippocampus lesions. The advantages of this approach include its efficiency, ease, minimalism, preservation of the temporalis muscle, and minimal retraction of the temporal lobe.

Petroclival Meningiomas: A Clinicopathological Correlation

Aim: Petroclival tumors are rare and require extensive skull base approaches, and are associated with high morbidity/mortality due to their location/relationship to adjacent neurovascular structures.

Endoscopic Transnasal Trans-sphenoidal Resection of Clival Chordomas: Selective Use, Useful Adjunct, or a New Standard of Care?

Introduction/Purpose: Clival chordomas are challenging lesions for which the optimal treatment is debated in the literature. Most would agree that radical resection, when possible, represents the best chance for long-term recurrence-free survival. Traditionally, extensive skull base approaches were necessary for radical resection. More recently, endoscopic techniques have become more popular, but their exact role in the surgical treatment of clival chordomas has yet to be determined.

Endoscopic Transnasal Trans-sphenoidal Resection of Clival Chordomas: Selective Use, Useful Adjunct, or a New Standard of Care?

Introduction: Clival chordomas are challenging lesions for which the optimal treatment is debated in the literature. Most would agree that radical resection, when possible, represents the best chance for long-term recurrence-free survival. Traditionally, extensive skull base approaches were necessary for radical resection. More recently, endoscopic techniques have become more popular, but their exact role in the treatment of clival chordomas has yet to be determined.

Endoscopic Transnasal Trans-sphenoidal Resection of Clival Chordomas: Selective Use, Useful Adjunct, or a New Standard of Care?

Introduction/Purpose: Clival chordomas are challenging lesions for which the optimal treatment is debated in the literature. Most would agree that radical resection, when possible, represents the best chance for long-term recurrence-free survival. Traditionally, extensive skull base approaches were necessary for radical resection. More recently, endoscopic techniques have become more popular, but their exact role in the surgical treatment of clival chordomas has yet to be determined.