Radiotherapy and temozolomide for newly diagnosed glioblastoma and anaplastic astrocytoma: validation of Radiation Therapy Oncology Group-Recursive Partitioning Analysis in the IMRT and temozolomide era.

Since the development of the Radiation Therapy Oncology Group-Recursive Partitioning Analysis (RTOG-RPA) risk classes for high-grade glioma, radiation therapy in combination with temozolomide (TMZ) has become standard care. While this combination has improved survival, the prognosis remains poor in the majority of patients. Therefore, strong interest in high-grade gliomas from basic research to clinical trials persists. We sought to evaluate whether the current RTOG-RPA retains prognostic significance in the TMZ era or alternatively, if modifications better prognosticate the optimal selection of patients with similar baseline prognosis for future clinical protocols. The records of 159 patients with newly-diagnosed glioblastoma (GBM, WHO grade IV) or anaplastic astrocytoma (AA, WHO grade III) were reviewed. Patients were treated with intensity-modulated radiation therapy (IMRT) and concurrent followed by adjuvant TMZ (n = 154) or adjuvant TMZ only (n = 5). The primary endpoint was overall survival. Three separate analyses were performed: (1) application of RTOG-RPA to the study cohort and calculation of subsequent survival curves, (2) fit a new tree model with the same predictors in RTOG-RPA, and (3) fit a new tree model with an expanded predictor set. All analyses used a regression tree analysis with a survival outcome fit to formulate new risk classes. Overall median survival was 14.9 months. Using the RTOG-RPA, the six classes retained their relative prognostic significance and overall ordering, with the corresponding survival distributions significantly different from each other (P < 0.01, χ(2) statistic = 70). New recursive partitioning limited to the predictors in RTOG-RPA defined four risk groups based on Karnofsky Performance Status (KPS), histology, age, length of neurologic symptoms, and mental status. Analysis across the expanded predictors defined six risk classes, including the same five variables plus tumor location, tobacco use, and hospitalization during radiation therapy. Patients with excellent functional status, AA, and frontal lobe tumors had the best prognosis. For patients with newly-diagnosed high-grade gliomas, RTOG-RPA classes retained prognostic significance in patients treated with TMZ and IMRT. In contrast to RTOG-RPA, in our modified RPA model, KPS rather than age represented the initial split. New recursive partitioning identified potential modifications to RTOG-RPA that should be further explored with a larger data set.

Treatment disparities following the diagnosis of an astrocytoma.

Post-operative radiation and chemotherapy following diagnosis of astrocytoma are standard care. No research has examined racial or insurance-based disparities in treatment receipt. The purpose of this study was to evaluate whether African Americans and patients with dual eligibility in Medicare and Medicaid (DE), compared to Caucasians and patients with Medicare alone, experienced differences in (1) seeing a radiation oncologist, (2) receiving radiation or chemotherapy, and (3) overall survival. Using a retrospective descriptive design, statewide Medicaid and Medicare data were merged with the Michigan Tumor Registry to extract a sample of patients (n = 604) ≥ 65 years old with a first primary astrocytoma diagnosis in Michigan between 1996 and 2000. There were no racial or insurance-based differences in reporting a claim for a radiation oncologist. Controlling for age, income, surgical intervention, residence population, comorbidities, gender, and stage, African Americans were less likely to report radiation claims than Caucasians (OR = 0.20; 95% CI = 0.07-0.54). DE patients were less likely to report radiation claims (OR = 0.50; 95% CI = 0.26-0.94) than those with Medicare only. These differences were not seen with chemotherapy. When only those with a glioblastoma multiforme were examined, DE patients (OR = 0.47; 95% CI = 0.24-0.92) and African Americans (OR = 0.13; 95% CI = 0.04-0.44) were much less likely to report radiation claims. Race and insurance status did not significantly affect survival, although income did. Data suggest disparities in race and insurance status may exist in receiving standard of care for astrocytomas. Further research is warranted to replicate the data and determine potential sources for these disparities.

Stereotactic radiosurgery to the resection cavity of brain metastases: a retrospective analysis and literature review.

PURPOSE: The aim of this study was to analyze results of stereotactic radiosurgery (SRS) as adjuvant therapy for resected brain metastases. METHODS: Medical records of patients treated at a single institution with SRS to the postoperative cavity of brain metastases were retrospectively reviewed. Patients who completed the prescribed SRS regimen following gross-total resection and had no previous whole brain radiotherapy were included in the study. Kaplan-Meier analyses were used to estimate local (LC) and intracranial control (IC), and overall survival (OS) rates. RESULTS: Between April 2005 and July 2010, 77 patients (median age 63 years) with 89 metastases met the inclusion criteria. The median prescription dose was 18 Gy (12-27 Gy) delivered in 1-3 fractions for a median target volume of 7.6 cm(3) (0.5-59 cm(3)). The 6-month, 1-year, and 2-year LC rates were 76.1, 76.1, and 74.3%, respectively. The 6-month, 1-year, and 2-year IC rates were 75.2, 54, and 43.6%, respectively. With a median follow-up of 13.8 months, the median OS was 14.5 months (1.9-51.4 months) after SRS. The overall 6-month, 1-year, and 2-year OS rates were 91, 62.5, and 43.6%, respectively. Complications included 2 patients with radiation necrosis. CONCLUSION: Adjuvant radiosurgery to the tumor cavity of resected brain metastases is well-tolerated and achieves LC in the majority of patients.

Protection of normal brain cells from γ-irradiation-induced apoptosis by a mitochondria-targeted triphenyl-phosphonium-nitroxide: a possible utility in glioblastoma therapy.

Glioblastoma multiforme is the most frequent and aggressive primary brain tumor. A strong rationale to identify innovative approaches to treat these tumors is required since treatment failures result in local recurrences and median survivals range from 9 to 12 months. Glioma cells are reported to have less mitochondrial content compared to adjacent normal brain cells. Based on this difference, we suggest a new strategy, utilizing protection of normal brain cells by mitochondria-targeted electron scavengers and antioxidants-nitroxides-thus allowing for the escalation of the radiation doses. In this paper, we report that a conjugate of nitroxide with a hydrophobic cation, triphenyl-phosphonium (TPEY-Tempo), significantly protected brain endothelial cells from γ-irradiation-induced apoptosis while radiosensitizing brain tumor cells. Thus, TPEY-Tempo may be a promising adjunct in the treatment of glioblastoma with the potential to not only prolong survival but also to maintain quality of life and reduce treatment toxicity.

Identifying Muir-Torre syndrome in a patient with glioblastoma multiforme.

Patients with Muir-Torre syndrome, an autosomal-dominant familial tumor condition caused by germline mutation of the DNA mismatch repair genes, MSH2 or MLH1, present with tumors of the sebaceous gland and visceral malignancies characterized by microsatellite instability. Here we show development of glioblastoma multiforme in a patient with Muir-Torre syndrome. Immunohistochemical analysis of the brain tumor and colon cancer revealed loss of the DNA mismatch repair gene detected by the genetic test, suggesting a pathogenic link.

Completely endoscopic resection of intraparenchymal brain tumors.

OBJECT: The authors introduce a novel technique of intraparenchymal brain tumor resection using a rod lens endoscope and parallel instrumentation via a transparent conduit. METHODS: Over a 4-year period, 21 patients underwent completely endoscopic removal of a subcortical brain lesion by means of a transparent conduit. Image guidance was used to direct the cannulation and resection of all lesions. Postoperative MR imaging or CT was performed to assess for residual tumor in all patients, and all patients were followed up postoperatively to assess for new neurological deficits or other surgical complications. RESULTS: The histopathological findings were as follows: 12 metastases, 5 glioblastomas, 3 cavernous malformations, and 1 hemangioblastoma. Total radiographically confirmed resection was achieved in 8 cases, near-total in 6 cases, and subtotal in 7 cases. There were no perioperative deaths. Complications included 1 infection and 1 pulmonary embolus. There were no postoperative hematomas, no postoperative seizures, and no worsened neurological deficits in the immediate postoperative period. CONCLUSIONS: Fully endoscopic resection may be a technically feasible method of resection for selected subcortical masses. Further experience with this technique will help to determine its applicability and safety.

Minimal-access technique for distal catheter insertion during ventricular peritoneal shunt procedures: a review of 100 cases.

The authors report the safety and efficacy of using a percutaneous minimal-access insertion technique for distal shunt catheter placement in 100 cases. From June 2007 to March 2008, they attempted 100 minimal-access insertions of distal shunt catheters in 91 patients who required ventriculoperitoneal shunting. Using the minimal-access approach, they avoided utilizing laparoscopic assistance or a mini-laparotomy in 91% of the cases. There were no bowel injuries or misplaced distal catheters. Additional outcomes in terms of operative times, cases that required conversion to open or laparoscopically assisted implantation, and infection rates are presented. They conclude that intraperitoneal shunt catheter placement can be safely and effectively accomplished using a simplified percutaneous minimal-access insertion method that does not require direct laparoscopic visualization.

Endoscopic endonasal suturing of dural reconstruction grafts: a novel application of the U-Clip technology. Technical note.

Cerebrospinal fluid (CSF) leakage following endoscopic endonasal skull base resection can be a significant problem. A method for securing tissue grafts is needed. In this paper the authors used an endonasal suturing device to secure the graft reconstruction following endonasal tumor resection. The U-Clip anastomotic device (Medtronic), developed for cardiovascular anastomoses, was used to secure the tissue graft to native dura. A specialized needle driver and hemoclip applier were used for the application and deployment of this device. No suture tying was necessary, facilitating its endonasal application. The graft was successfully secured in its desired position to native dura by using the U-Clip anastomotic device. The patient did not suffer a postoperative CSF leak, and postoperative imaging and endoscopy revealed that the graft was in a good position. There was no complication from the use of the device. The U-Clip anastomotic device can be used as a suture device during endonasal surgery. It may prevent tissue graft migration and help prevent CSF leakage.

Expanded endonasal approach, a fully endoscopic transnasal approach for the resection of midline suprasellar craniopharyngiomas: a new classification based on the infundibulum.

OBJECT: Craniopharyngiomas are notoriously difficult to treat. Surgeons must weigh the risks of aggressive resection against the long-term challenges of recurrence. Because of their parasellar location, often extending well beyond the sella, these tumors challenge vision and pituitary and hypothalamic function. New techniques are needed to improve outcomes in patients with these tumors while decreasing treatment morbidity. An endoscopic expanded endonasal approach (EEA) is one such technique that warrants understanding and evaluation. The authors explain the techniques and approach used for the endoscopic endonasal resection of suprasellar craniopharyngiomas and introduce a tumor classification scheme. METHODS: The techniques and approach used for the endoscopic, endonasal resection of suprasellar craniopharyngiomas is explained, including the introduction of a tumor classification scheme. This scheme is helpful for understanding both the appropriate expanded approach as well as relevant involved anatomy. RESULTS: The classification scheme divides tumors according to their suprasellar extension: Type I is preinfundibular; Type II is transinfundibular (extending into the stalk); Type III is retroinfundibular, extending behind the gland and stalk, and has 2 subdivisions (IIIa, extending into the third ventricle; and IIIb, extending into the interpeduncular cistern); and Type IV is isolated to the third ventricle and/or optic recess and is not accessible via an endonasal approach. CONCLUSIONS: The endoscopic EEA requires a thorough understanding of both sinus and skull base anatomy. Moreover, in its application for craniopharyngiomas, an understanding of tumor growth and extension with respect to the optic chiasm and infundibulum is critical to safely approach the lesion via an endonasal route.

The evolution of the endonasal approach for craniopharyngiomas.

Craniopharyngiomas have always been an extremely challenging type of tumor to treat. The transsphenoidal route has been used for resection of these lesions since its introduction. The authors present a historical review of the literature from the introduction of the endonasal route for resection of craniopharyngiomas until the present. Abandoned early due to technological limitations, this approach has been expanded both in its application and in its anatomical boundaries with subsequent progressive improvements in outcomes. This expansion has coincided with advances in visualization devices, imaging guidance techniques, and anatomical understanding. The progression from the use of headlights, to microscopy, to endoscopy and fluoroscopy, and finally to modern intraoperative magnetic resonance-guided techniques, combined with collaboration between otolaryngologists and neurosurgeons, has provided the framework for the development of current techniques for the resection of sellar and suprasellar craniopharyngiomas.

Outcomes following endoscopic, expanded endonasal resection of suprasellar craniopharyngiomas: a case series.

OBJECT: Craniopharyngiomas are challenging tumors that most frequently occur in the sellar or suprasellar regions. Microscopic transsphenoidal resections with various extensions and variations have been performed with good results. The addition of the endoscope as well as the further expansion of the standard and extended transsphenoidal approaches has not been well evaluated for the treatment of this pathological entity. METHODS: The authors performed a retrospective review of all patients who underwent a purely endoscopic, expanded endonasal approach (EEA) for the resection of craniopharyngiomas at their institution between June 1999 and February 2006. Endocrine and ophthalmological outcomes, extent of resection, and complications were evaluated. RESULTS: Sixteen patients underwent endoscopic EEA for the resection of craniopharyngiomas. Five patients (31%) presented with recurrent disease. Complete resection was planned in 11 of the 16 patients. Three elderly patients with vision loss underwent planned debulking, 1 patient with vision loss and a moderate-sized tumor had express wishes for debulking, and 1 patient had a separate, third ventricular nodule that was not resected. Of those in whom complete resection was planned, 91% underwent near-total (2/11) or gross-total (8/11) resection. No patient who underwent gross-total resection suffered a recurrence. The mean follow-up period was 34 months. Of the 14 patients who presented with vision loss, 93% had improvement or complete recovery and 1 patient's condition remained stable. No patient experienced visual worsening. Eighteen percent of patients (without preexisting hypopituitarism) developed panhypopituitarism and 8% developed permanent diabetes insipidus. There were no cases of new obesity. The postoperative cerebrospinal fluid leak rate was 58%. All leaks were resolved, and there were no cases of bacterial meningitis. There was 1 vascular injury (posterior cerebral artery perforator branch) resulting in the only new neurological deficit. No patient died. CONCLUSIONS: Endoscopic EEA for the resection of craniopharyngiomas provides acceptable results and holds the potential to improve outcomes.

Expanded endonasal approach: vidian canal as a landmark to the petrous internal carotid artery.

The purpose of this study was to describe the technique used to safely identify the petrous carotid artery during expanded endonasal approaches to the skull base. A series of 20 cadaveric studies was undertaken to isolate the vidian artery and nerve and to use them as landmarks to the petrous internal carotid artery (ICA). Twenty-five consecutive paraclival endoscopic cases were also reviewed to determine the consistency of the vidian artery in vivo as an intraoperative landmark to the ICA. These data were then correlated with results from a separate study in which computed tomography scans from 44 patients were evaluated to delineate the course of the vidian canal and its relationship to the petrous ICA. In all 20 cadaveric dissections and all 25 surgical cases, the vidian artery was consistently identified and could be reliably used as a landmark to the ICA. The correlation between anatomical and clinical data in this paper supports the consistent use of the vidian artery as an important landmark to the petrous ICA.

Diffusion-weighted magnetic resonance imaging demonstrating intraventricular rupture of a cerebral abscess and subsequent therapeutic response.

BACKGROUND: The most feared complication of a pyogenic brain abscess is intraventricular rupture. Mortality for this event has been traditionally reported to be approximately 80%. Appreciation of the incidence of IVROBA has likely increased with the dawn of CT and MRI. In selected cases, a patient with IVROBA may demonstrate a functional survival with low morbidity, if therapy is initiated quickly and aggressively. CASE DESCRIPTION: The authors report the IVROBA in a 49-year-old patient despite appropriate abscess drainage and broad-spectrum intravenous antibiotic administration. Diffusion-weighted MRI was particularly useful in this case for the demonstration of not only the intraventricular rupture but also the subsequent resolution of the inflammatory response within the ventricular system in response to aggressive ventricular drainage and systemic antibiotic therapy. CONCLUSION: Diffusion-weighted MRI can be applicable both to the diagnosis of IVROBA as well as to the response to appropriate surgical therapy. With aggressive treatment, a good outcome is achievable in the setting of IVROBA.

Endoscopic endonasal clipping of an unsecured superior hypophyseal artery aneurysm. Technical note.

Paraclinoidal aneurysms, especially superior hypophyseal artery (SHA) aneurysms (with medial projection), can be challenging to access via a pterional craniotomy and damage to the optic nerve can occur during surgery. The authors have previously reported on endonasal clipping and aneurysmorrhaphy of a vertebral artery aneurysm following proximal and distal protection of the aneurysm using partial coil embolization. To the best of the authors' knowledge no unprotected aneurysm has been clipped using an endonasal approach. The 56-year-old woman in this report was found to have two unruptured aneurysms: an anterior communicating artery (ACoA) aneurysm and an SHA aneurysm. An endoscopic endonasal, transplanar-transsellar approach was used to successfully clip the SHA aneurysm. Proximal and distal control was obtained endonasally prior to successful clip occlusion of the aneurysm. The ACoA aneurysm was clipped via a pterional craniotomy during the same anesthetic session. This report shows that it is possible to successfully clip a medially projecting, paraclinoidal aneurysm using an endonasal approach. Such cases must be chosen with extreme caution and only performed by surgeons with significant experience with both endoscopic endonasal approaches and neurovascular surgery.

Transpalatal endoscopic endonasal resection of a giant epignathus skull base teratoma in a newborn. Case report.

Teratomas are neoplasms composed of tissues from all three germ layers with varying degrees of differentiation. They are most commonly found in the sacrococcygeal and gonadal regions and rarely occur in the head and neck region. A teratoma is termed "epignathus" when it arises from the skull base or hard palate and is located in the oral cavity. The authors describe a case of a giant epignathus teratoma originating in the skull base of a neonate, extending bilaterally via two pedicles throughout the hard palate and protruding through the oral cavity. The tumor was completely resected using a transpalatal endoscopic endonasal approach. The excised tumor proved to be an immature teratoma with well-differentiated yolk sac elements. At the 1-year follow-up the patient showed no evidence of tumor recurrence and the child remains neurologically intact. This report demonstrates the use of a transpalatal endonasal corridor in a preterm infant. This approach provided an ample corridor into the ventral skull base without the need for external excisions and/or disruption of osseous elements.

Fully endoscopic expanded endonasal approach treating skull base lesions in pediatric patients.

OBJECT: The authors reviewed their experience with endoscopic approaches to determine their safety and efficacy in the treatment of pediatric patients who harbor skull base lesions. Although they were interested in ascertaining outcomes after surgery as well as validating and defining indications and limitations of these approaches, the authors recognized that the follow-up duration was inadequate to assess long-term outcomes. METHODS: The authors conducted a retrospective review of all endoscopic procedures performed at their institution between January 2000 and September 2005. The procedures were categorized into a series of anatomical modular approaches. Twenty-five patients 18 years of age or younger were identified. The surgical goals were individualized and included gross-total resection, partial resection, biopsy, decompression of neural structures, and repair of a cerebrospinal fluid (CSF) leak. One patient required an open procedure in addition to the expanded endonasal approach for definitive therapy. No patient suffered a neurological deficit, vascular injury, or central nervous system infection. A CSF leak was the most common complication and occurred in two (8%) of the 25 patients. CONCLUSIONS: In well-selected patients, the expanded endonasal approach represents a safe, effective, and minimally invasive technique for the treatment of skull base lesions in children. Incremental experience is needed for acquiring the skills with endoscopic techniques to progress to the more complex modular approaches.

Vidian canal: analysis and relationship to the internal carotid artery.

OBJECTIVES: The purpose of this study is to describe the anatomy and relationships of the vidian canal to known endonasal and skull base landmarks. This will allow the endoscopic skull base surgeon to safely approach the anterior genu of the petrous carotid artery during expanded endonasal approaches to the skull base. STUDY DESIGN: The study is a prospective cohort study. METHODS: Axial, coronal, and sagittal computed tomography scans of the paranasal sinuses and skull base of 44 patients were examined. Individuals with known skull base pathology were excluded. Measurements included the length of the vidian canal, the relationship of the vidian canal to the anterior genu of the petrous carotid artery, and the type of pneumatization of the sphenoid sinus as it pertains to foramen rotundum and the vidian canal. In addition, we will focus on the relationship of the vidian canal to the sphenopalatine foramen and base of the medial pterygoid plate. RESULTS: The degree of pneumatization of the sphenoid sinus is highly variable. The mean length of the vidian canal is 18 mm (10-23 mm). The vidian canal is found entirely within bone in 27% to 30% of scans reviewed. The anterior genu of the petrous internal carotid artery is found superior-medial to the vidian canal in 44 of 44 of the CT scans reviewed. The vidian canal runs medial to lateral in 93% to 98% of patients studied. CONCLUSIONS: As a result of this study the endoscopic skull base surgeon has a number of anatomical landmarks and measurements that may be helpful in safely localizing the anterior genu of the petrous internal carotid artery during expanded endonasal approaches to the skull base.

Acquisition of surgical skills for endonasal skull base surgery: a training program.

INTRODUCTION: Endonasal surgery represents a radical change in the practice of cranial base surgery and requires the acquisition of new knowledge and surgical skills. The optimal training program for surgeons has not been established. METHODS: We reviewed our experience with endonasal cranial base surgery from 1998 to 2006 to develop a training plan for the acquisition of surgical skills. It consists of a modular and incremental approach to endonasal skull base surgery that is designed to train surgeons to function as a team, learn endoscopic skull base anatomy, and develop fundamental endoscopic skills. RESULTS: Stages of training are established for the otolaryngologist-head and neck surgeon and the neurosurgeon that are based on level of technical difficulty, potential risk of vascular and neural injury, and unfamiliar endoscopic anatomy. Mastery of each level is recommended before attempting procedures at a higher level. CONCLUSIONS: Standardization of training and the adoption of a modular, incremental training program are expected to facilitate the training of endonasal surgeons in both surgical specialties. Adherence to such a program during the growth phase of endoscopic skull base surgery may decrease the risk of complications as the surgeon's knowledge and surgical expertise develop.

Improving the design of the pedicled nasoseptal flap for skull base reconstruction: a radioanatomic study.

BACKGROUND: Reconstruction of the skull base after an expanded endonasal approach (EEA) is critical to achieve a good outcome. A novel technique based on the use of a pedicled nasoseptal flap has proven to be a reliable and versatile reconstructive option for extensive defects of the skull base. Data regarding the potential dimensions of a nasoseptal flap are lacking in the literature. This pilot study was developed to help optimize the design of the nasoseptal flap and to ensure that when harvesting the flap, its width and length are adequate to reconstruct the defects that are created by various EEAs. METHODS: We analyzed the computed tomographic (CT) scans of four patients who underwent EEAs for skull base lesions. Sagittal and coronal CT reconstructions were generated from axial images. The measurements were divided into skull base measurements, flap dimensions required to cover skull base defects resulting from various EEAs, and potential maximal dimensions of the nasoseptal flap. Measurements were studied for three different EEAs: sellar/transplanar, transclival, and transcribiform/anterior skull base. We measured the potential defects for each of these EEAs and the nasoseptal flap dimensions that would be required to reconstruct them. We estimated all dimensions based on the most extensive defect that could result with each EEA. We then compared these with various modifications of the nasoseptal flap. RESULTS: Two male and two female patients were studied. Twenty-seven measurements were taken to compare the different skull base defects and nasoseptal flaps. CONCLUSIONS: The length of the nasal septum comprises sufficient mucoperichondrium and mucoperiosteum to allow the harvesting of a nasoseptal flap that could cover any defect resulting from an anterior skull base, a transsellar/transplanar, or a transclival EEA. Similarly, the height of the nasal septum has the potential to yield a nasoseptal flap with a width that is adequate to cover the laterolateral aspect of any defect of the anterior skull base and clivus. Skull base defects resulting from combined EEAs, such as those that would create a defect that comprises the skull base from sella turcica to frontal sinus, are beyond the potential dimensions of a single nasoseptal flap. This and other defects resulting from a combination of EEAs require other strategies, such as the use of bilateral nasoseptal flaps, or the use of other reconstructive options.

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.