Faculty Bibliography

OBJECT/OBJECTIVE:The management of recurrent or residual craniopharyngiomas remains controversial. Although possible, revision surgery is more challenging than primary surgery, and more often results in incomplete resection and an increased risk of death and complications. The extended (also called expanded) endoscopic endonasal transsphenoidal approach through the planum sphenoidale has been proposed over the past decade as an alternative surgical route for removal of various suprasellar tumors including craniopharyngiomas. In this study, the authors describe the feasibility and advantages of this technique in recurrent or symptomatic residual craniopharyngiomas. METHODS:Between January 2004 and June 2008, 22 patients underwent surgery via the extended endoscopic transsphenoidal approach for the treatment of recurrent or residual symptomatic craniopharyngiomas at either the University of Pittsburgh or the Universita degli Studi di Napoli. The lesions included 12 purely suprasellar craniopharyngiomas, 9 with both intra- and suprasellar extensions, and 1 arising from a remnant in the Meckel cave. To better evaluate the features of the extended endonasal approach for recurrent or residual craniopharyngiomas, each patient was assigned to 1 of 3 subgroups depending on the original surgical treatment: transcranial pterional route (13 patients), transphenoidal approach (3 patients; 2 microsurgically and 1 with the standard endoscopic technique), or extended endonasal endoscopic approach (6 patients). RESULTS:Total removal was achieved in 9 patients (40.9%), and in 8 patients (36.4%) near-total removal (defined as >95% removal) was possible. Subtotal removal (>70%) was attained in 4 patients (18.2%), and tumor removal was partial (<50%) in only 1 case (4.5%). There were no deaths or major complications, including behavior changes. Postoperative CSF leaks developed in 2 patients in the transcranial subgroup, and 1 in the transsphenoidal subgroup (overall rate 13.6%), requiring early successful endoscopic revision surgery for the cranial base defect. CONCLUSIONS:Most of the advantages of the endoscopic endonasal technique were noted during tumor dissection from the inferior aspect of the chiasm, the infundibulum, the third ventricle, and/or the retro- and parasellar areas. These benefits were best appreciated in patients who had originally undergone transcranial surgery, since in such cases the authors' endoscopic endonasal approach was a virgin route. However, the extended endoscopic endonasal technique can also be safely used in patients who originally underwent transsphenoidal surgery. The endoscopic endonasal technique should be considered as a therapeutic option in selected cases of recurrent or symptomatic residual craniopharyngiomas.

OBJECT/OBJECTIVE:External ventricular drain (EVD) placement is one of the most common neurosurgical procedures performed. Rates and significance of hemorrhage associated with this procedure have not been well quantified. METHODS:All adults who underwent EVD placement at the University of Pittsburgh Medical Center between July 2002 and June 2003 were evaluated for catheter-associated hemorrhage. Patients without postprocedural imaging were excluded. RESULTS:Seventy-seven (41%) of 188 EVDs were associated with imaging evidence of hemorrhage after either placement or removal. Most of these were insignificant, punctate intraparenchymal, or trace subarachnoid hemorrhages (51.9%). Thirty-seven (19.7%) were associated with larger hemorrhages, which were divided into 3 groups according to volume of hemorrhage: 16 patients (8.5%) had < 15 ml of hemorrhage, 20 (10.6%) had hemorrhages of > 15 ml or associated intraventricular hemorrhage, and in 1 case there was a subdural hematoma that required surgical evacuation. No hemorrhages larger than punctate or trace were seen after EVD removal. Hemorrhage was associated with 44.3% of EVDs placed in an intensive care unit compared with 34.8% in EVDs placed in the operating room (p > 0.10). CONCLUSIONS:External ventricular drain placement has a significant risk of associated hemorrhage. However, the hemorrhages are rarely large and almost never require surgical intervention. There is a favorable trend, but no significant risk reduction when EVDs are placed in the operating room rather than the intensive care unit.

OBJECTIVE:Tumors within Meckel's cave are challenging and often require complex approaches. In this report, an expanded endoscopic endonasal approach is reported as a substitute for or complement to other surgical options for the treatment of various tumors within this region. METHODS:A database of more than 900 patients who underwent the expanded endoscopic endonasal approach at the University of Pittsburgh Medical Center from 1998 to March of 2008 were reviewed. From these, only patients who had an endoscopic endonasal approach to Meckel's cave were considered. The technique uses the maxillary sinus and the pterygopalatine fossa as part of the working corridor. Infraorbital/V2 and the vidian neurovascular bundles are used as surgical landmarks. The quadrangular space is opened, which is bound by the internal carotid artery medially and inferiorly, V2 laterally, and the abducens nerve superiorly. This offers direct access to the anteroinferomedial segment of Meckel's cave, which can be extended through the petrous bone to reach the cerebellopontine angle. RESULTS:Forty patients underwent an endoscopic endonasal approach to Meckel's cave. The most frequent abnormalities encountered were adenoid cystic carcinoma, meningioma, and schwannomas. Meckel's cave and surrounding structures were accessed adequately in all patients. Five patients developed a new facial numbness in at least 1 segment of the trigeminal nerve, but the deficit was permanent in only 2. Two patients had a transient VIth cranial nerve palsy. Nine patients (30%) showed improvement of preoperative deficits on Cranial Nerves III to VI. CONCLUSION/CONCLUSIONS:In selected patients, the expanded endoscopic endonasal approach to the quadrangular space provides adequate exposure of Meckel's cave and its vicinity, with low morbidity.

OBJECTIVE:Cranial base chordomas are difficult lesions to treat. The endoscopic endonasal approach (EEA) takes advantage of the natural sinus corridor and may provide a less invasive approach for these midline tumors. METHODS:Patients undergoing EEA for chordomas were selected from a database of more than 800 consecutive patients undergoing EEA at the University of Pittsburgh Medical Center and were retrospectively evaluated. Additionally, a systematic review of the literature of endoscopic endonasally resected chordomas was performed and compared with our personal experience. RESULTS:Twenty patients (8 females and 12 males) underwent 26 endoscopic EEAs for cranial base chordomas. Eight chordomas (40%) were recurrent. Treatment of the 12 newly diagnosed chordomas included 8 total resections (66.7%), 2 near total resections (16.7%), and 2 subtotal resections (16.7%). Treatment of the 8 recurrent chordomas included 1 gross total resection (12.5%), 2 near total resections (25.0%), and 5 subtotal resections (62.5%). Two patients (10%) had recurrences, and 5 patients (25%) progressed during the mean follow-up period of 13 months (range, 1-45 months). Five patients (25%) underwent re-resection, 1 patient was lost to follow-up, and 1 patient died secondary to progression of disease. There was 1 intraoperative vascular complication with no sequelae. The cerebrospinal fluid leak rate was 25%, and there were no cases of bacterial meningitis. The incidence of a new permanent neurological complication was 5%. A systematic review of the literature yielded a total of 26 cases of chordomas resected via a completely endoscopic endonasal technique. CONCLUSION/CONCLUSIONS:Endoscopic endonasal resection of cranial base chordomas is safe once adequate experience is gained with the technique. This approach provides the potential for, at the least, similar resections compared with traditional cranial base approaches while potentially limiting morbidity.

OBJECTIVES/OBJECTIVE: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. STUDY DESIGN/METHODS:Feasibility. METHODS:We reviewed radiology images with attention to the pterygopalatine fossa and the descending palatine vessels (DPV), which supply the palate. Using cadaver dissections, we investigated the feasibility of transposing the standard mucoperiosteal palatal flap into the nasal cavity and mobilizing the DPV for pedicled skull base reconstruction. RESULTS:We transposed the palate mucoperiosteum into the nasal cavity through limited enlargement of a single greater palatine foramen. Our method preserves the integrity of the nasal floor mucosa, and mobilizes the DPV from the greater palatine foramen to their origin in the pterygopalatine fossa. Radiological measurements and cadevaric dissections suggest that the transposed, pedicled palatal flap (the Oliver pedicled palatal flap) could be used to reconstruct defects of the planum, sella, and clivus. CONCLUSIONS:Our novel modifications to the island palatal flap yield a large (12-18 cm(2)) mucoperiosteal flap based on a approximately 3 cm pedicle. The Oliver pedicled palatal flap shows potential for nasal cavity and skull base reconstruction (see video, available online only).

Olfactory schwannomas are rare tumors of the anterior skull base that are possibly derived from ectopic Schwann cells, perivascular neural tissue, or sensory nerves of the meninges. The authors report the case of a 14-year-old boy with an olfactory schwannoma that extended inferiorly through the cranial base and superiorly into the frontal lobe. Because of the growth characteristics of the tumor and the significant overlying frontal lobe edema, the lesion was approached via an endonasal endoscopic route, as a strategy to minimize brain retraction. This tumor was characterized radiographically as contrast-enhancing with cystic areas and erosion into bone. The tumor showed immunoreactivity for S100 protein and leukocyte antigen 7 (CD57) but not epithelial membrane antigen, supporting the diagnosis of olfactory schwannoma. A gross-total resection was achieved. This approach represents a novel application of endoscopic endonasal surgery to the pediatric neurosurgical context, as well as a favorable outcome in an extremely unusual tumor type, that should be applicable to other appropriately selected pediatric brain tumors.

OBJECT/OBJECTIVE: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.

OBJECTIVE:The endonasal route may be feasible for the resection of anterior cranial base tumors that abut the paranasal sinuses. There are several case reports and mixed case series discussing this approach. Other than pituitary adenomas, there is a lack of literature describing the outcomes of endonasal approaches for single-tumor types such as meningiomas. METHODS:In this study, we describe our current endoscopic endonasal technique and demonstrate the feasibility of using it to access anterior cranial base meningiomas from the back wall of the frontal sinus to the sella and laterally to the region of the midorbit. After this discussion, which includes key technical considerations and nuances, we address safety and efficacy by reporting the outcomes of our early experience with endoscopic endonasal resection of 35 anterior cranial base meningiomas. RESULTS:A total of 35 patients underwent endoscopic endonasal resection of anterior cranial base meningiomas from October 2002 to October 2005. Degree of resection by tumor location was as follows: 10 of the 12 (83%) patients with olfactory groove meningiomas planned for complete resection underwent gross total (seven of 12) or near-total (>95%) (three of 12) resection (67% of all 15 olfactory tumors); 12 of 13 patients (92%) with tuberculum meningiomas underwent gross (11 of 13) or near (>95%) (one of 13) total resection; five patients diagnosed with petroclival meningiomas had successful resection of the parasellar portion of their tumors with relief of visual symptoms (no patients underwent complete resection of their tumors via the endoscopic, endonasal approach); two giant petroclival meningiomas were debulked with 63 and 89% resection, respectively.All patients experienced resolution or improvement of visual symptoms. No patient experienced permanent worsening of vision after surgery. Only one (3%) patient without preoperative endocrine dysfunction experienced a new, permanent pituitary deficit, diabetes insipidus. One (3%) patient experienced a new neurological deficit after experiencing a hemorrhage 3 weeks after surgery. The postoperative cerebrospinal fluid leak rate was 40% (14 of 35) and varied by tumor location. All leaks were resolved without craniotomy. There were no cases of bacterial meningitis. One patient developed a superinfection of a sterile granuloma from a sinusitis 2 years after surgery. There were two cases of deep venous thrombosis and one pulmonary embolus. There were no operative or perioperative deaths. CONCLUSION/CONCLUSIONS:Cranial base meningiomas can be successfully managed via a purely endoscopic endonasal approach with acceptable morbidity and mortality rates. The extent of resection is guided by patient factors and symptoms, not by approach. This series had a high cerebrospinal fluid leak rate. With the evolution of new reconstruction techniques, these rates have been substantially reduced.

OBJECTIVE:Reconstruction of the cranial base using vascularized tissue promotes rapid and complete healing, thus avoiding complications caused by persistent communication between the cranial cavity and the sinonasal tract. The Hadad-Bassagasteguy flap (HBF), a neurovascular pedicled flap of the nasal septum mucoperiosteum and mucoperichondrium based on the nasoseptal artery, seems to be advantageous for the reconstruction of the cranial base after endonasal cranial base surgery. METHODS:We performed a retrospective review of patients who underwent endonasal cranial base surgery at the University of Pittsburgh Medical Center from January 30, 2006 to January 30, 2007, identifying patients who experienced reconstruction with a vascularized septal mucosal flap (HBF). We analyzed the demographic data, pathological characteristics, site and extent of resection, use of cerebrospinal fluid (CSF) diversion techniques, and outcome. RESULTS:Seventy-five patients who underwent endonasal cranial base endoscopic surgery received repair with the HBF. In this population, we encountered eight postoperative CSF leaks (10.66%), all in patients who required intra-arachnoidal dissection. When we correct the statistical analysis to include only patients with intra- arachnoidal lesions, the postoperative CSF leak rate is 14.5% (eight of 55 patients). It is notable that six CSF (33%) leaks occurred in our first 25 repairs, whereas we encountered only two postoperative leaks (4%) in the last 50 patients. The corrected CSF leak rate, considering only intra-arachnoidal lesions, was two (5.4%) of 37 patients. This improvement in the CSF leak rate reflects our growing experience and comfort with this reconstructive technique. All of our failures could be matched to a specific technical mistake. In addition, we modified the flap-harvesting technique to allow for staged procedures and the removal of caudal lesions. These special circumstances require storage of the flap in the antrum during the removal of caudal lesions, and suturing of the flap in its original position for staged procedures. One patient experienced a posterior nose bleed from the posterior nasal artery. This was controlled with bipolar electrocautery, thereby preserving the flap blood supply. We encountered no infectious or wound complications in this series of patients. The donor site accumulates crusting, which requires debridement until mucosalization is complete; this usually occurs 6 to 12 weeks after surgery. CONCLUSION/CONCLUSIONS:The HBF is a versatile and reliable reconstructive technique for repairing defects of the anterior, middle, clival, and parasellar cranial base. Its use has resulted in a significant decrease in our incidence of CSF leaks after endonasal cranial base surgery. Attention to technical details is of paramount importance to achieve the best outcomes.