Transmaxillary Transpterygoid Approach Research Articles

Combined endoscopic endonasal transpterygoid and sublabial transmaxillary approaches for a large infratemporal fossa trigeminal schwannoma.

Trigeminal schwannomas (TSs) with solitary extracranial location are rare, and surgical excision is challenging. In recent years, the endoscopic endonasal transmaxillary transpterygoid approach (EETPA) has been advocated as an effective strategy for TSs in the infratemporal fossa (ITF). We describe the steps of the EETPA combined with the sublabial transmaxillary approach for the surgical excision of a giant mandibular schwannoma of the ITF. Indications, advantages, and approach-specific complications are also discussed. The main surgical steps are shown in an operative video. A combined EETPA and sublabial transmaxillary approach represents a safe and effective option for the surgical excision of extracranial TSs.

Temporal Galeofascial Flap for Reconstruction After Transmaxillary Approaches to the Clival Region

A paramount concern after transmaxillary approaches has been skull base reconstruction. Regional pedicled flaps represent the best reconstructive option. We have described a technique to harvest a lateral-based multilayered vascularized flap for skull base reconstruction after resection of large tumors using the transmaxillary transpterygoid approach (TMTPA). We performed a cadaver study using the TMTPA to harvest the combined temporal galeofascial flap (CTGF). The first layer, with major sealing capabilities, is composed by a temporoparietal galeal-pericranial flap. The second layer is composed by temporal muscle fascia to provide mechanical support for flap dural engrafting. The CTGF provides excellent coverage of both the clival dural lining and the ipsilateral pterygopalatine fossa structures (×1.6). The CTGF is pliable and easy to harvest. It offers great flexibility in flap content and design, providing a large quantity of vascularized tissue. The vascular pedicle derives from the superficial temporal vessels, which can ensure flap trophism. CTGF represents an effective option as a regional multilayered pedicled flap for skull base reconstruction after resection of clival tumors using the TMTPA. The flap pedicle, owing to its anatomical location, will often be preserved even after repeated microsurgical or endoscopic procedures, providing a technical alternative for reconstruction even in patients who have undergone multiple surgeries with low residual availability of regional flaps.

An Alternative Endoscopic Anterolateral Route to Meckel's Cave: An Anatomic Feasibility Study Using a Sublabial Transmaxillary Approach.

To describe an endoscopic anterolateral surgical route to the lateral portion of Meckel's cave. A sublabial transmaxillary transpterygoid approach was performed in 6 cadaveric heads (12 sides). A craniectomy was drilled between the foramen rotundum (FR) and foramen ovale (FO) with defined borders. Extradural dissection was performed up to the V2-V3 junction of the trigeminal ganglion. The working space was analyzed using anatomic measurements. The approach allowed for extradural dissection to the lateral aspect of Meckel's cave and provided excellent exposure of V2, V3, and the V2-V3 junction at the gasserian ganglion. The mean distance between the FR and FO along the pterygoid process of the sphenoid bone was 21.3 ± 2.8 mm (range, 18-24.4 mm). The mean distance of V2 and V3 segments from their foramina to the gasserian ganglion junction was 12.0 ± 2.3 mm (range, 9.2-14.6 mm) and 15.2 ± 2.7 mm (range, 12.3-18.5 mm), respectively (6 sides). A potential working area (mean area, 89 mm2) is described. Its superior edge is from the FR to the V2-V3 junction at the gasserian ganglion, its inferior edge is from the FO to the V2-V3 junction at the gasserian ganglion, and its base is from the FO to the FR. The surgical anatomy of the infratemporal fossa, pterygopalatine fossa, and lateral Meckel's cave is highlighted. An endoscopic anterolateral sublabial transmaxillary transpterygoid approach between the FR and FO avoids crossing critical neurovascular structures within the cavernous sinus and pterygopalatine fossa and can provide a safe surgical corridor for laterally based lesions in Meckel's cave.

Endoscopic Transnasal Approach to the Infratemporal and Upper Parapharyngeal Tumors: Indications and Outcomes

Objectives: Describe the endoscopic transnasal approach to the infratemporal fossa (ITF) and upper parapharyngeal region (UPR), and analyze the indications and outcomes of this surgical technique in the management of the tumors localized in this critical area. Methods: Retrospective review of patients with benign and malignant tumors arising in or extending to the ITF and UPR, treated from 2002 to 2012 at a single institute. The tumors were surgically resected using an endoscopic transnasal transmaxillary transpterygoid approach, combined with a posterior septotomy to improve the controlateral maneuverability of surgical instruments. Results: Thirty-one consecutive patients with benign tumors (20 juvenile nasopharyngeal angiofibromas, 2 extracranial trigeminal schwannomas, 2 meningiomas, and 1 cavernous hemangioma) and malignancies (2 adenoid-cystic carcinoma, 1 mucoepidermoid carcinoma, 1 squamous-cell carcinoma, 1 adenocarcinoma, and 1 recurrence of chondrosarcoma after chemo-radiation therapy) were treated with curative intent. A gross-total resection was achieved in 28/30 patients. Major complications were observed in 1 case (intra-operative internal carotid artery blowout), and minor complications (postoperative palate and/or cheek numbness) were observed in 4 cases. Postoperatively, the 5 primitive malignancies received intensity-modulated radiotherapy. Mean follow-up was 30 months for malignancies and 54 months for benign tumors. All patients are now alive without recurrences, with stable intracranial persistence of disease in 2 cases (1 meningioma and 1 adenoid-cystic carcinoma). Conclusions: The purely endoscopic transnasal technique may provide a minimally-invasive and safe approach to resect selected tumors involving the ITF and UPR. Larger case series and longer follow-up are needed to validate the reproducibility and efficacy of this technique.

Endoscopic Surgery in the Skull Base Unit: Experience in the First 72 Cases

Abstract Introduction A multidisciplinary team is essential to develop and expand the indications in endonasal endoscopic skull base surgery. The aim of this study was to present our experience in a group of patients with skull base lesions treated using endonasal endoscopic approach. Methods From January 2008 to January 2012, 72 patients with skull base involvement were diagnosed and treated in our centre. Results The mean patient age was 53 years. The different pathologies included 36 pituitary adenomas, 10 cerebrospinal fluid leaks and 5 inverted papillomas as the most frequent pathologies. We performed a transsphenoidal transellar approach in 45 cases, a transmaxillary transpterygoid approach in 4 cases and a transnasal expanded approach in 6 cases. We performed an ethmoidal/sphenoidal approach in 12 patients and a Draf IIb/III procedure in four cases. Total resection was achieved in 61% of patients with pituitary adenomas, subtotal in 22% and partial in 17%. Successful repair was achieved in 86% of CSF leaks. No recurrences were observed in patients with inverted papilloma. Complications were observed in 21 patients (29%), 6 being major complications. Conclusions Our centre stresses the importance of multidisciplinary collaboration in endoscopic endonasal skull base surgery.

Integración de la cirugía endoscópica en una unidad de base de cráneo: experiencia en los primeros 72 casos

IntroductionA multidisciplinary team is essential to develop and expand the indications in endonasal endoscopic skull base surgery.The aim of this study was to present our experience in a group of patients with skull base lesions treated using endonasal endoscopic approach. MethodsFrom January 2008 to January 2012, 72 patients with skull base involvement were diagnosed and treated in our centre. ResultsThe mean patient age was 53 years. The different pathologies included 36 pituitary adenomas, 10 cerebrospinal fluid leaks and 5 inverted papillomas as the most frequent pathologies. We performed a transsphenoidal transellar approach in 45 cases, a transmaxillary transpterygoid approach in 4 cases and a transnasal expanded approach in 6 cases. We performed an ethmoidal/sphenoidal approach in 12 patients and a Draf IIb/III procedure in four cases. Total resection was achieved in 61% of patients with pituitary adenomas, subtotal in 22% and partial in 17%. Successful repair was achieved in 86% of CSF leaks. No recurrences were observed in patients with inverted papilloma. Complications were observed in 21 patients (29%), 6 being major complications. ConclusionsOur centre stresses the importance of multidisciplinary collaboration in endoscopic endonasal skull base surgery.

Endoscopic approaches to the trigeminal nerve and clinical consideration for trigeminal schwannomas: a cadaveric study

The course of the trigeminal nerve straddles multiple fossae and is known to be very complex. Comprehensive anatomical knowledge and skull base techniques are required for surgical management of trigeminal schwannomas. The aims of this study were to become familiar with the endoscopic anatomy of the trigeminal nerve and to develop a minimally invasive surgical strategy for the treatment of trigeminal schwannomas. Ten fresh cadavers were studied using 5 endoscopic approaches with the aid of 4-mm 0° and 30° endoscopes to identify surgical landmarks associated with the trigeminal nerve. The endoscopic approaches included 3 transcranial keyhole approaches (the extradural supraorbital, extradural subtemporal, and retrosigmoid approaches), and 2 endonasal approaches (the transpterygoid and the transmaxillary transpterygoid approaches). The trajectories of the extradural supraorbital, transpterygoid, and extradural subtemporal approaches corresponded with the course of the first, second, and third divisions of the trigeminal nerve, respectively. The 3 approaches demonstrated each division in intra- and extracranial spaces, as well as the Meckel cave in the middle cranial fossa. The interdural space at the lateral wall of the cavernous sinus was exposed by the extradural supraorbital and subtemporal approaches. The extradural subtemporal approach with anterior petrosectomy and the retrosigmoid approach visualized the trigeminal sensory root and its neighboring neurovascular structures in the posterior cranial fossa. The transmaxillary transpterygoid approach revealed the course of the third division in the infratemporal fossa. The 5 endoscopic approaches effectively followed the course of the trigeminal nerve with minimal invasiveness. These approaches could provide alternative options for the management of trigeminal schwannoma.

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 approaches to the cavernous sinus

Skull base tumors that involve the cavernous sinus (CS) present a challenge to the endoscopic surgeon. Most such lesions arise from sellar pathology that involves the medial wall of the CS, which can be accessed by a transsphenoidal transsellar approach. Tumors that arise primarily in the medial CS may be accessed via a transethmoidal transsphenoidal parasellar approach, which avoids the dissection of sellar contents but requires the removal of bone overlying the carotid artery. Involvement of the tumor in the lateral CS may be accessed by a transmaxillary transpterygoid approach in patients who wish to avoid a craniotomy and in whom radiosurgery is not an option. These tumors are associated with a greater risk of cranial nerve injury, including extraocular palsy. Important adjuncts to the endoscopic approach include angled instrumentation, neuronavigation, intraoperative Doppler and intrathecal fluorescein injection. Tumor extirpation from the CS and cytoreduction are realistic goals for the endoscopic surgeon in well-selected cases. Skull base tumors that involve the cavernous sinus (CS) present a challenge to the endoscopic surgeon. Most such lesions arise from sellar pathology that involves the medial wall of the CS, which can be accessed by a transsphenoidal transsellar approach. Tumors that arise primarily in the medial CS may be accessed via a transethmoidal transsphenoidal parasellar approach, which avoids the dissection of sellar contents but requires the removal of bone overlying the carotid artery. Involvement of the tumor in the lateral CS may be accessed by a transmaxillary transpterygoid approach in patients who wish to avoid a craniotomy and in whom radiosurgery is not an option. These tumors are associated with a greater risk of cranial nerve injury, including extraocular palsy. Important adjuncts to the endoscopic approach include angled instrumentation, neuronavigation, intraoperative Doppler and intrathecal fluorescein injection. Tumor extirpation from the CS and cytoreduction are realistic goals for the endoscopic surgeon in well-selected cases.

Quantification of clival and paraclival exposure in the Le Fort I transmaxillary transpterygoid approach: a microanatomical study

The authors describe a modified Le Fort I maxillotomy with medial and posterior antrectomy and removal of the pterygoid plates, aimed at improving the lateral surgical exposure during open transmaxillary surgery for pathological conditions involving the clivus. A cadaveric microanatomical study was conducted to compare the planimetric exposures allowed by the transmaxillary transpterygoid (TMTP) approach and the standard Le Fort I maxillotomy (STM). Six cadaveric specimens that had been fixed with glutaraldehyde and injected with latex were dissected to obtain morphometric measurements after both TMTP and STM approaches. The anatomical areas exposed by the surgical approaches were calculated using ImageJ 1.37a software. As expected, the TMTP approach allowed for a greater surgical exposure, with an incremental area exposed ranging from 4.9 to 7.6 cm(2) (mean ± standard deviation 6.4 ± 1.2 cm(2), 95% CI 5.4-7.4 cm(2)). The amount of additional anatomical area visualized, as recorded as a percentage increase after the TMTP approach when compared with the STM approach, ranged from 83 to 109% (mean 99%). The lateral surgical exposure allowed by the STM approach is limited by the pterygoid plates. The TMTP approach significantly improves the exposure of the anatomical regions lateral to the clivus, allowing access to the pterygopalatine and medial infratemporal fossae. In comparison with the STM, the TMTP approach allows for a surgical exposure that is nearly double. The authors conclude that the TMTP approach provides a significant improvement in the surgical exposure of the lateral paraclival areas, when compared with the STM approach.