Endonasal endoscopic exposure of the internal carotid artery: an anatomical study.

OBJECTIVES/HYPOTHESIS: The aim of this work was to define the anatomical landmarks, limitations, and difficulties of obtaining internal carotid artery (ICA) exposure via endonasal endoscopic approaches (EEA). STUDY DESIGN: Cadaveric descriptive study. METHODS: The ICA was dissected via EEA in 10 cadaveric specimens (20 sides) prepared with intravascular injections of colored silicone. We carried the ICA dissection from the cavernous to the distal parapharyngeal segments through a transpterygoid corridor. RESULTS: The transpterygoid approach provided adequate exposure of the lacerum and horizontal petrous ICA. Additional exposure of the ICA and the infrapetrous area required resection of the eustachian tube (ET) and the fibrocartilaginous tissue of the foramen lacerum after a medial maxillectomy and resection of the pterygoid plates. The main anatomical landmarks to the corresponding ICA segment include: the vidian nerve that points to the lacerum and horizontal segments, the mandibular nerve (V3) that heralds the petrous segment, the foramen ovale and the ET that signal toward the carotid canal, and the posterior trunk of the mandibular nerve (V3) and the ET that mark the parapharyngeal segment. CONCLUSIONS: EEAs provide access to the ICA from its cavernous to the distal parapharyngeal segments. A stepwise approach is critical to its exposure and control. Surgeons must be aware of its frequently tortuous three-dimensional course and the intimate relation of the vessel to the carotid canal and the cartilage of the foramen lacerum.

Endoscopic anatomy of the pterygopalatine fossa and the transpterygoid approach: development of a surgical instruction model.

INTRODUCTION: The pterygopalatine fossa (PPF) is a narrow space located between the posterior wall of the antrum and the pterygoid plates. Surgical access to the PPF is difficult because of its protected position and its complex neurovascular anatomy. Endonasal approaches using rod lens endoscopes, however, provide better visualization of this area and are associated with less morbidity than external approaches. Our aim was to develop a simple anatomical model using cadaveric specimens injected with intravascular colored silicone to demonstrate the endoscopic anatomy of the PPF. This model could be used for surgical instruction of the transpterygoid approach. METHODS: We dissected six PPF in three cadaveric specimens prepared with intravascular injection of colored material using two different injection techniques. An endoscopic endonasal approach, including a wide nasoantral window and removal of the posterior antrum wall, provided access to the PPF. RESULTS: We produced our best anatomical model injecting colored silicone via the common carotid artery. We found that, using an endoscopic approach, a retrograde dissection of the sphenopalatine artery helped to identify the internal maxillary artery (IMA) and its branches. Neural structures were identified deeper to the vascular elements. Notable anatomical landmarks for the endoscopic surgeon are the vidian nerve and its canal that leads to the petrous portion of the internal carotid artery (ICA), and the foramen rotundum, and V2 that leads to Meckel's cave in the middle cranial fossa. These two nerves, vidian and V2, are separated by a pyramidal shaped bone and its apex marks the ICA. CONCLUSION: Our anatomical model provides the means to learn the endoscopic anatomy of the PPF and may be used for the simulation of surgical techniques. An endoscopic endonasal approach provides adequate exposure to all anatomical structures within the PPF. These structures may be used as landmarks to identify and control deeper neurovascular structures. The significance is that an anatomical model facilitates learning the surgical anatomy and the acquisition of surgical skills. A dissection superficial to the vascular structures preserves the neural elements. These nerves and their bony foramina, such as the vidian nerve and V2, are critical anatomical landmarks to identify and control the ICA at the skull base.

The posterior pedicle inferior turbinate flap: a new vascularized flap for skull base reconstruction.

BACKGROUND: Expanded endonasal approaches (EEA) for the resection of lesions of the anterior and ventral skull base can create large defects with a significant risk of postoperative cerebrospinal fluid (CSF) leaks or exposure of the internal carotid artery. In these cases, a reconstruction using a vascularized flap facilitates rapid and complete healing of the defect. The Hadad-Bassagasteguy flap (HBF), a posterior pedicle nasoseptal flap, is our preferred reconstructive option; however, a prior posterior septectomy or prior wide sphenoidotomies preclude its use. We have developed two additional pedicled flaps to reconstruct these selected patients: the transpterygoid temporoparietal fascia flap, which is suitable for large defects, and the posterior pedicle inferior turbinate flap (PPITF), the subject of this paper. METHODS: We developed a flap comprising the inferior turbinate mucoperiosteum pedicled on the inferior turbinate artery, a terminal branch of the posterior lateral nasal artery, which arises from the sphenopalatine artery. We retrospectively reviewed the clinical data of four patients who underwent a skull base reconstruction using a PPITF. RESULTS: Four patients underwent a reconstruction with the PPITF after undergoing an EEA that produced a skull base defect associated with a CSF fistula (n = 2), an exposed internal carotid artery (n = 1), or a basilar aneurysm clip (n = 1). All patients had undergone posterior septectomies as part of previous EEAs. All flaps healed uneventfully and covered the entire defect. CONCLUSION: The PPITF is a viable reconstructive option for patients with skull base defects of a limited size defect and in whom the HBF is not available.

Mandibular subluxation for distal cervical exposure of the internal carotid artery.

INTRODUCTION: Surgical access to the distal segment of the cervical internal carotid artery (ICA) is a challenge because of the limited exposure imposed by bony structures and concern regarding cranial nerve and major vasculature injury. Our objective is to quantify the additional exposure of the distal cervical ICA obtained with mandibular subluxation (MS) compared with maneuvers that do not mobilize the mandible. METHODS: Thirty dissections of the cervical ICA and common carotid artery bifurcation were performed on fresh cadavers. The length of the ICA exposure was measured from the carotid bifurcation to the most distally exposed ICA after sectioning the posterior belly of the digastric and stylohyoid muscles, removal of the styloid process, and MS. RESULTS: After MS, a 5.52 +/- 1.00 cm mean exposure of the cervical ICA was obtained. Comparison between the second and third measures revealed an average additional exposure of the ICA of 0.77 cm, corresponding to an additional 16.2% (P < .001). Neck length, sex, and age showed no correlation with the ICA exposure. CONCLUSION: MS provided an additional exposure of the distal segment of the cervical ICA and may be useful in selected cases to improve access. However, staged maneuvers should be used, and the need for MS depends on the level and extension of the lesion.

Transpterygoid transposition of a temporoparietal fascia flap: a new method for skull base reconstruction after endoscopic expanded endonasal approaches.

BACKGROUND: Endoscopic expanded endonasal approaches (EEAs) for the resection of lesions of the anterior and ventral skull base can create large defects that present a significant risk of postoperative cerebrospinal fluid (CSF) leak. These defects, especially in patients who received preoperative radiotherapy, are best reconstructed with vascularized tissue. The Hadad-Bassagasteguy flap, a pedicled nasoseptal flap, is our preferred method for reconstruction. This option is not available, however, in patients who underwent a previous posterior septectomy or in those with tumors that invade the pterygopalatine fossa (PPF) or sphenoid sinus rostrum. In this scenario, we have used a temporoparietal fascial flap (TPFF) for the reconstruction of large surgical defects. METHODS: We developed a new technique for the transposition of the TPFF into the nasal cavity to reconstruct skull base defects after EEA. The flap is harvested using a conventional hemicoronal incision but is then advanced to the defect using a temporal-infratemporal tunnel and an endonasal transpterygoid approach. The latter is created using an endoscopic endonasal approach that involves the resection of the posterior wall of the antrum, dissection of the PPF, and partial resection of the pterygoid plates. These maneuvers open a bone window to accommodate the flap. The soft tissue tunnel, extending from the temporal to the infratemporal and then to the PPF, is opened with percutaneous tracheostomy dilators. We present a detailed description of the surgical technique and a retrospective review of two cases in which we used this technique. RESULTS: Two patients with large CSF fistulas who had undergone preoperative radiotherapy were reconstructed transposing the TPFF through a transpterygoid tunnel. We obtained an adequate exposure for placing the flap endonasally, and the flap provided complete coverage of the skull base defect. Both CSF leaks were resolved without any additional morbidity from the flap or the access technique. CONCLUSION: The TPFF is a reliable and versatile method for the reconstruction of the anterior, middle, clival, and parasellar skull base after EEAs. Its harvesting requires an external incision; thus, it is not our preferred method of reconstruction. It is recommended for large dural defects in patients with previous posterior septectomy and previous radiation treatment.

Tissue maturation correlating to clinical manifestations in juvenile angiofibroma.

OBJECTIVES: Juvenile nasopharyngeal angiofibroma is a rare benign tumor that affects young male patients and shows a characteristic development from its origin. It is not a true neoplasm, but shows features of vascular processes, developing into a more fibrous condition. The aim of this study was to correlate the clinical manifestations and the histologic findings of the tumor. METHODS: Thirty-six patients without previous treatment were studied. We correlated the incidence and duration of the clinical manifestations (nasal obstruction, epistaxis, nasal and/or pharyngeal tumor, and facial deformity) and morphometric histologic analyses of the central region of the tumor (number, caliber, and presence of muscle cells in the vessel wall, and tissue maturity and cellularity). RESULTS: The duration of nasal obstruction, the presence of nasal and/or pharyngeal tumor, and facial deformity were significantly correlated with the number of vessels, the tissue maturation, and the cellularity of the tumor. Epistaxis showed a strong correlation with the presence of muscle fibers in the vessels. CONCLUSIONS: There are correlations between the duration of the clinical manifestations and histologic maturation in the central portion of the tumor.

Melhora da qualidade de vida em crianças após adenoamigdalectomia / Quality of life improvement in children after adenotonsillectomy

O aumento de volume das tonsilas palatina e faríngea é um dos problemas mais freqüentes do consultório do otorrinolaringologista e é a principal causa de apnéia obstrutiva do sono em crianças. OBJETIVO: Avaliar o impacto da adenoamigdalectomia na qualidade de vida em crianças com hiperplasia adenoamigdaliana. FORMA DE ESTUDO: Clínico prospectivo. MATERIAL E MÉTODO: Trinta e seis pais ou responsáveis de crianças submetidas a adenoamigdalectomia foram entrevistados antes e após a cirurgia através do questionário sobre qualidade de vida específica desenvolvido por Serres et al., 2000, que inclui os domínios: sofrimento físico, distúrbios do sono, problemas de fala e deglutição, desconforto emocional, limitação das atividades e preocupação do responsável. RESULTADOS: A qualidade de vida de todas as crianças melhorou após a cirurgia. Foi observada correlação direta entre o grau de obstrução e distúrbios do sono, preocupação paterna, e na média dos domínios. Correlacionando-se os domínios entre si, observamos relação estatística entre sofrimento emocional e distúrbios do sono, preocupação paterna e distúrbios do sono, limitação das atividades físicas e desconforto emocional. CONCLUSÃO: O aumento das tonsilas e a apnéia obstrutiva do sono pioram a qualidade de vida das crianças, principalmente pelo sofrimento físico e distúrbios do sono. A adenoamigdalectomia realmente traz uma melhora importante na qualidade de vida destes pacientes.

Relaçäo anatômica entre o nervo hipoglosso e a bifurcaçäo carotídea / Anatomical relation between the hypoglossal nerve and the carotid artery bifurcation

Introduçäo: Nas últimas décadas o índice de complicaçöes neurológicas centrais e mortalidade após cirurgia da artéria carótida (tumor do corpo carotídeo e endarterectomia) diminuiu significativamente. A lesäo de nervos cranianos continua pouco alterada e elevada, e a lesäo do nervo hipoglosso é a mais freqüente. Objetivo: Estudar a relaçäo entre o nervo hipoglosso e a bifurcaçäo carotídea, determinando a distância entre estas estruturas, além de estudar a influência do sexo, idade, raça e comprimento do pescoço sobre esta medida. Forma de estudo: Experimental. Material e método: Foram realizadas 38 dissecçöes da artéria carótida em 38 cadáveres. Os cadáveres eram colocados em posiçäo padräo (pescoço em extensäo de 95º). Após identificaçäo do nervo e da bifurcaçäo carotídea, foi medida a distância entre as estruturas. O comprimento do pescoço foi medido do processo mastóide até a incisura jugular. Resultados: O nervo hipoglosso näo foi encontrado abaixo da bifurcaçäo, e a distância entre o nervo e a bifurcaçäo variou de 0.5 a 4.3 cm (média = 2.1 cm, mediana = 2.0 cm, desvio padräo = 0.63 cm). Comprimento do pescoço, sexo, raça e idade näo demonstraram significância estatística. Conclusäo: Nesta amostra observamos grande variaçäo anatômica entre o nervo hipoglosso e a bifurcaçäo carotídea, e näo houve correlaçäo com comprimento do pescoço, sexo, raça e idade. Um melhor entendimento da anatomia do nervo hipoglosso e a sua variaçäo em relaçäo à bifurcaçäo carotídea säo importantes para prevenir lesäo do nervo hipoglosso