Shaan M. Raza and Franco DeMonte
This video describes the surgical management of an epidermoid cyst within the cerebellopontine angle and petroclival region with involvement of cranial nerves V through XI and the vertebrobasilar system. A retrosigmoid craniotomy was performed for gross total resection of the lesion. The key steps of the procedure are discussed, including: positioning, soft tissue dissection, craniotomy, microsurgical dissection/resection, closure. Additionally, surgical nuances with regards to the safe maximal resection of such lesions are detailed.
The video can be found here: http://youtu.be/VEROVO5cYdU.
Sameer Deshmukh and Franco Demonte
✓ The rare occurrence of an inflammatory mucocele in a pneumatized anterior clinoid process is described. The patient, a 20-year-old woman, presented with a severe visual field defect in her right eye associated with abnormality in the right anterior clinoid process identified on computed tomography and magnetic resonance imaging. Initially, surgical intervention was recommended for resection of a possible neoplasm. The patient's clinical history, however, was significant for sinusitis accompanied by sore throat and right ear infection that resolved with oral antibiotic therapy. When her condition was evaluated approximately 1 month after the onset of her visual symptoms, the patient had regained full visual acuity in the affected eye. Surgical exploration was not required, and the patient's optic neuropathy reversed with appropriate antibiotic therapy.
Sarfaraz Sadruddin, L. Jeffrey Medeiros and Franco DeMonte
The rare occurrence of T-cell lymphoblastic lymphoma as a primary tumor in the cavernous sinus is described. The patient, a 17-year-old girl, presented with right-sided ophthalmic and maxillary neuropathy and diplopia due to neuropathies of cranial nerves III and VI. An enhancing mass in the cavernous sinus was identified on MR imaging. Dexamethasone was prescribed but did not provide symptomatic relief. Rapid progression of symptoms led to open biopsy, and a diagnosis of T-cell lymphoblastic lymphoma was made. The patient promptly underwent aggressive chemotherapy in which a modified hyper–cyclophosphamide, vincristine, and dexamethasone without doxorubicin regimen with concurrent radiotherapy was used. The patient achieved complete remission and is currently completing the 2-year maintenance phase of chemotherapy.
Franco DeMonte and Paul W. Gidley
In the early 1960s William F. House developed the middle fossa approach for the removal of small vestibular schwannomas (VSs) with the preservation of hearing. It is the best approach for tumors that extend laterally to the fundus of the internal auditory canal, although it does have the potential disadvantage of increased facial nerve manipulation, especially for tumors arising from the inferior vestibular nerve. The aim of this study was to monitor the hearing preservation and facial nerve outcomes of this approach.
A prospective database was constructed, and data were retrospectively reviewed.
Between December 2004 and January 2012, 30 patients with small VSs underwent surgery via a middle fossa approach for hearing preservation. The patients consisted of 13 men and 17 women with a mean age of 46 years. Tumor size ranged from 7 to 19 mm. Gross-total resection was accomplished in 25 of 30 patients. Preoperative hearing was American Academy of Otolaryngology–Head and Neck Surgery (AAO-HNS) Class A in 21 patients, Class B in 5, Class C in 3, and undocumented in 1. Postoperatively, hearing was graded as AAO-HNS Class A in 15 patients, Class B in 7, Class C in 1, Class D in 2, and undocumented in 5. Facial nerve function was House-Brackmann (HB) Grade I in all patients preoperatively. Postoperatively, facial nerve function was HB Grade I in 28 patients, Grade III in 1, and Grade IV in 1. There were 3 complications: CSF leakage in 1 patient, superficial wound infection in 1, and extradural hematoma (asymptomatic) in 1. The overall hearing preservation rate of at least 73% and HB Grade I facial nerve outcome of 93% in this cohort are in keeping with other contemporary reports.
The middle fossa approach for the resection of small VSs with hearing preservation is a viable and relatively safe option. It should be considered among the various options available for the management of small, growing VSs.
Franco DeMonte and Ehab Hanna
Achieving microscopically tumor-free margins during resection of skull base malignancies has consistently been identified as a positive prognostic factor for patient survival. When malignancies extend perineurally into the major nerves traversing the skull base and entering the cavernous sinus, achieving tumor-free margins can be challenging and typically necessitates performing a craniotomy to access the lateral wall of the cavernous sinus. This report describes a novel technique used to access and resect malignancy extending perineurally into the intracranial portion of V2 via the maxillary sinus.
Seven patients with maxillary sinus tumors and perineural extensions along V2, who underwent resection of the primary tumor and transmaxillary intracranial exposure and dissection of the maxillary nerve to achieve maximal tumor resection, were analyzed. Prospectively collected data, including symptoms, clinical signs, diagnostic imaging data, pathological diagnosis, incidence and nature of complications, adjuvant therapies, and oncological outcomes, were retrospectively analyzed.
All patients in this cohort had trigeminal nerve symptomatology as well as abnormal enhancement in the pterygopalatine fissure as noted on magnetic resonance imaging. The transmaxillary exploration of the maxillary nerve technique was used in all seven patients, resulting in gross-total resection of the tumors in every patient. At the last follow-up (mean 30 months, range 13–58 months, in four of seven patients for > 2 years), six patients were alive without evidence of local disease. One patient with squamous cell carcinoma died of progressive infratemporal fossa and regional neck disease 26 months after resection. No intracranial or cavernous sinus disease was present.
This technique extended the limits of resection without the need for a craniotomy and improved local tumor control in this patient cohort.
Franco DeMonte and Ossama Al-Mefty
✓ The syndrome of fat embolism is a well-known clinicopathological entity that may appear 2 to 4 days after skeletal trauma; nontraumatic causes have been recognized, however. This report details the fat embolism syndrome occurring in a patient after surgery within the cavernous sinus to remove a dermoid tumor.
Stephen J. Hentschel and Franco DeMonte
Olfactory groove meningiomas (OGMs) arise over the cribriform plate and may reach very large sizes prior to presentation. They can be differentiated from tuberculum sellae meningiomas because OGMs arise more anterior in the skull base and displace the optic nerve and chiasm inferiorly rather than superiorly.
The authors searched the neurosurgery database at the M. D. Anderson Cancer Center for cases of OGM treated between 1993 and 2003. The records of these patients were then reviewed retrospectively for details regarding clinical presentation, imaging findings, surgical results and complications, and follow-up status.
Thirteen patients, (12 women and one man, mean age 56 years) harbored OGMs (mean size 5.7 cm). All patients underwent bifrontal craniotomies and biorbital osteotomies. There were 11 complete resections (including the hyperostotic bone and dura of the cribriform plate and any extension into the ethmoid sinuses) and two subtotal resections with minimal residual tumor left in patients with recurrent lesions. No complication directly due to the surgery occurred in any patient. There were no recurrences in a mean follow-up period of 2 years (range 0–5 years).
With current microsurgical techniques, the results of OGM resection are excellent, with a high rate of total resection and a low incidence of complications. All hyperostotic bone should be removed with the dura of the anterior skull base to minimize the risk of recurrence.