Trevor Hackman

Palatal flap modifications allow pedicled reconstruction of the skull base.

Objectives: Defects after endoscopic expanded endonasal approaches (EEA) to the skull base, have exposed limitations of traditional reconstructive techniques. The ability to adequately reconstruct these defects has lagged behind the ability to approach/resect lesions at the skull base. The posteriorly pedicled nasoseptal flap is our primary reconstructive option; however, prior surgery or tumors can preclude its use. We focused on the branches of the internal maxillary artery, to develop novel pedicled flaps, to facilitate the reconstruction of defects encountered after skull base expanded endonasal approaches.

Juvenile nasopharyngeal angiofibroma: The expanded endonasal approach

Background Juvenile nasopharyngeal angiofibroma (JNA) is a benign but locally aggressively vascular tumor that may involve the skull base and extend intracranially. Endoscopic excision has become the new standard for smaller tumors but remains a challenge for large tumors, leading some to advocate radiation therapy. We reviewed our experience managing JNA, specifically with respect to utility of the expanded endonasal approach (EEA) for lesions with skull base and intracranial extension. Methods All cases of JNA at the University of Pittsburgh Medical Center from 1995 to 2006 were reviewed with respect to tumor size and location, vascular supply and results of embolization, skull base involvement and intracranial extension, surgical approach, blood loss, intraoperative and postoperative complications, and recurrence. Results Thirty-one cases of JNA were identified. The majority of tumors were completely excised using the EEA, regardless of size or extension into adjacent compartments. Surgical excision of some tumors with intracranial blood supply was staged. Recurrence rates were not associated with extent of tumor or surgical technique. Long-term morbidity was minimal. Conclusion Most JNA, regardless of tumor extent, may be completely excised using EEA alone or in combination with minor sublabial incisions avoiding the morbidity associated with larger open approaches or postoperative radiation therapy.

Powered instrumentation and tissue effects in the nose and paranasal sinuses.

Purpose of review The technologic cornerstones of endoscopic sinus surgery initially rested on the endoscope and CT scanning. In the mid-1990s, the advent of powered instrumentation, in particular the microdebrider, advanced the surgeons ability to treat polypoid disease, sinus and nasal disease in a bleeding field, choanal atresia, antral choanal polyps, and inferior turbinate hypertrophy. This review evaluates both positive and negative tissue effects secondary to powered instrumentation. Recent findings Recent reports of deleterious outcomes with powered instrumentation require a reevaluation of the role of powered instrumentation and consideration of factors that lead to injury. The rapidity of injury makes the powered instrument especially dangerous in inexperienced hands. One third of participants in a recent survey were unaware that powered instruments could be involved in orbital injury and half were unaware that cranial injuries could be secondary to powered instrumentation. Summary Microdebriders will continue to advance the field of endoscopic surgery, providing clearer operative fields and causing less tissue trauma in experienced hands. However, the severity of complications, including the potential for rapidly aspirating orbital and cerebral contents when laminae are violated, must be appreciated and respected.

Maturation pathways of dendritic cells determine TAP1 and TAP2 levels and cross-presenting function.

Ability to cross-present exogenous antigens in the human leukocyte antigen class I pathway is key to the antigen presenting function of mature tumor cell-loaded dendritic cells (DC). Conditions of DC maturation have been shown to be important for DCs ability to produce proinflammatory cytokines and induce T cell effector functions. However, it remains unknown if the different pathways of maturation are associated with modulation of the ability of mature DCs to cross-present tumor antigens (TA). Here, we compare DC matured with 3 clinically relevant cytokine combinations including interleukin (IL)-1β, tumor necrosis factor-α, IL-6 (termed DC-0), DC-0 cells incubated with prostaglandin-2 (termed DC-0+prostaglandin-2), or DC treated with interferon-γ, interferon-α, tumor necrosis factor-α, Poly I:C, and IL1-β (termed DC-1). We found that these DC vary in their ability to cross-present TA to cytotoxic T lymphocytes (CTL), with the DC-1 cytokine combination being significantly more effective than the other 2. TA cross presentation and CTL priming were strongly correlated with level of expression of the antigen processing machinery components, TAP1 and TAP2, indicating that these components could be used as biomarkers to standardize DC preparations for optimal function. However, the up-regulation of TAP1/TAP2 was not sufficient to explain the enhanced cross-presentation ability of DC-1 cells, as the use of IFN-γ alone to up-regulate TAP1/TAP2 did not generate DC as effective at cross-presentation as the full DC-1 maturation cytokine combination. These data indicate for the first time that the pathways of DC maturation modulate antigen processing machinery component expression to different extents and that differently matured DC vary in the ability to cross-present TA to human leukocyte antigen class I-restricted CTL.

Novel application of the palatal island flap for endoscopic skull base reconstruction

INTRODUCTION The frontiers of endoscopic anterior skull base surgery have been dramatically advanced in the last decade, with further expansion along the sagittal and coronal planes, thus allowing the skull base surgeon to address more advanced tumors. However, until recently, the significant rate limiting step for wide spread application of the endoscopic approach has been the availability of reliable means of postextirpative reconstructive techniques. The goals of endoscopic reconstruction follows the same principles and goals as the reconstruction after open approaches, which is to provide separation of the cranial and sinonasal cavities to prevent cerebrospinal fluid (CSF) leakage, pneumocephalus, and ascending intracranial infection. One of the major developments in endoscopic skull base surgery that meets all these criteria for reconstruction is the recent description of the Hadad-Bassagasteguy flap (HBF), a vascularized mucoperiosteal pedicled flap of the nasal septum based on the nasoseptal artery. The availability of this option has resulted in a sharp decrease in the incidence of postoperative CSF leaks for endonasal approaches and provides great comfort for the endoscopic skull base surgeon due to its reliability and technical ease of harvest and inset. Although the septal flap has become a workhorse for endoscopic reconstruction in most primary surgeries, it may not be available every time, as in recurrent cases with previous septectomies, patients with previous septoplasty operations with large perforations, or in patients with tumors involving the posterior septum, rostrum of the sphenoid sinus, or pterygopalatine fossa, where compromise of the blood supply to the HBF is a given. In the search for alternative endoscopically accessible local flaps in cases where the nasal septal flap is unavailable and where CSF leaks are encountered, we have explored the utility of the pedicled palatal island flap, which has a long history of use in the oral cavity for skull base reconstruction. Herein, we present the novel application of a pedicled palatal flap for reconstruction of a clival defect created after resection of a recurrent clival chordoma in a patient with limited options due to previous open resection. Thus, this first clinical application, which was recently described in a cadaver model, shows significant promise for the recurrent skull base surgery case where limited reconstructive options remain.

Endoscopic Surgical Management of Vidian Nerve Schwannoma

Vidian nerve schwannomas are highly unusual, with only two reported cases in the world literature, and present with a constellation of symptoms that may be extremely vague. In the reported cases, open techniques have been utilized that required significant dismantling of the midfacial skeleton to access and manage these skull base lesions. Over the last 15 years, a paradigm shift in base of skull surgery has evolved with the advent of transnasal endoscopic techniques and instrumentation, improved surgical access and resectability of most skull‐based pathologies, including vidian nerve lesions as reported here. We describe the varied clinical presentation and radiologic findings in two patients with such rare lesions. In addition, in one of these patients, we report on the first use of an expanded endonasal technique to access and remove vidian nerve schwannomas entirely endoscopically.