Spinal sealant system provides better intraoperative watertight closure than standard of care during spinal surgery: a prospective, multicenter, randomized controlled study.

STUDY DESIGN: Prospective, 3:1 randomized, single-blind, multicenter investigational study. OBJECTIVE: To assess the safety and efficacy of a low-swell spinal sealant when used as an adjunct to sutured dural repair compared with standard of care methods to obtain watertight dural closure in subjects undergoing spinal surgery. SUMMARY OF BACKGROUND DATA: Watertight dural closure is paramount in spinal surgery to avoid complications of cerebrospinal fluid leak. Prior reports have proven the efficacy of a synthetic, absorbable polyethylene glycol (PEG) hydrogel sealant in spinal surgery compared with standard of care. Given the potential concerns of swelling in spinal applications, the hydrogel was modified to a low-swell formulation. METHODS: The primary endpoint was success rate in obtaining intraoperative watertight dural closure in subjects receiving PEG hydrogel sealant versus a control group of subjects receiving any standard method designed to provide intraoperative watertight closure. Subjects were evaluated at discharge and at 30 and 90 days postprocedure for cerebrospinal fluid leaks, surgical site infections, and adverse events. RESULTS: Between May 2007 and May 2009, 98 subjects (74 PEG hydrogel spinal sealant, 24 control) were randomized at 14 clinical sites in the United States. Patients treated with the PEG hydrogel spinal sealant had a significantly higher rate of watertight closure than the control (98.6% vs. 79.2%, P = 0.003). No statistical differences were seen in postoperative cerebrospinal fluid, infection, and wound healing. No neurological deficits were seen attributable to the sealant. CONCLUSION: The low-swell PEG hydrogel spinal sealant evaluated in this study has been proven safe and effective for providing watertight closure when used as an adjunct to sutured closure of intentional durotomies during spinal surgery. PEG hydrogel sealants have again proved superior to other standard of care technologies for safe, efficacious dural closure. LEVEL OF EVIDENCE: 2.

Measuring surgical outcomes in neurosurgery: implementation, analysis, and auditing a prospective series of more than 5000 procedures.

OBJECT: Health care reform debate includes discussions regarding outcomes of surgical interventions. Yet quality of medical care, when judged as a health outcome, is difficult to define because of impediments affecting accuracy in data collection, analysis, and reporting. In this prospective study, the authors report the outcomes for neurosurgical treatment based on point-of-care interactions recorded in the electronic medical record (EMR). METHODS: The authors' neurosurgery practice collected outcome data for 19 physicians and ancillary personnel using the EMR. Data were analyzed for 5361 consecutive surgical cases, either elective or emergency procedures, performed during 2009 at multiple hospitals, offices, and an ambulatory spine surgery center. Main outcomes included complications, length of stay (LOS), and discharge disposition for all patients and for certain frequently performed procedures. Physicians, nurses, and other medical staff used validated scales to record the hospital LOS, complications, disposition at discharge, and return to work. RESULTS: Of the 5361 surgical procedures performed, two-thirds were spinal procedures and one-third were cranial procedures. Organization-wide compliance with reporting rates of major complications improved throughout the year, from 80.7% in the first quarter to 90.3% in the fourth quarter. Auditing showed that rates of unreported complications decreased from 11% in the first quarter to 4% in the fourth quarter. Complication data were available for 4593 procedures (85.7%); of these, no complications were reported in 4367 (95.1%). Discharge dispositions reported were home in 86.2%, rehabilitation center in 8.9%, and nursing home in 2.5%. Major complications included culture-proven infection in 0.61%, CSF leak in 0.89%, reoperation within the same hospitalization in 0.38%, and new neurological deficits in 0.77%. For the commonly performed procedures, the median hospital LOS was 3 days for craniotomy for aneurysm or intraaxial tumor and less than 1 day for angiogram, anterior cervical discectomy with fusion, or lumbar discectomy. CONCLUSIONS: With prospectively collected outcome data for more than 5000 surgeries, the authors achieved their primary end point of institution-wide compliance and data accuracy. Components of this process included staged implementation with physician pilot studies and oversight, nurse participation, point-of-service data capture, EMR form modification, data auditing, and confidential surgeon reports.

A multicenter, single-blind, prospective randomized trial to evaluate the safety of a polyethylene glycol hydrogel (Duraseal Dural Sealant System) as a dural sealant in cranial surgery.

OBJECTIVE: Incisional cerebrospinal fluid (CSF) leakage after cranial surgery is a significant cause of morbidity due to poor wound healing and infection, meningitis, and pseudomeningocele formation. Many common dural closure techniques, such as sutures, autologous grafts, gelatin or collagen sponges, and fibrin glues, are used to achieve watertight closure, although none are US Food and Drug Administration approved for this use. DuraSeal Dural Sealant System is a polyethylene glycol (PEG) hydrogel approved by the U.S. Food and Drug Administration for obtaining watertight dural closure when applied after standard dural suturing. This multicenter, prospective randomized study further evaluated the safety of a PEG hydrogel compared with common dural sealing techniques. METHODS: A total of 237 patients undergoing elective cranial surgery at 17 institutions were randomized to dural closure augmented with the PEG hydrogel or a control "standard of care" dural sealing technique after Valsalva maneuver demonstrated an intraoperative nonwatertight dural closure. Data were collected on complications resulting in unplanned postoperative interventions or reoperations, surgical site infections, CSF leaks, and other neurological complications within 30 days. Surgeons also provided data on the ease of use of the dural sealing techniques, as well as preparation and application times. RESULTS: The incidences of neurosurgical complications, surgical site infections, and CSF leaks were similar between treatment and control groups, with no statistically significant difference between the measures. In the PEG hydrogel group (n = 120), the incidence of neurosurgical complications was 5.8% (n = 7), the incidence of surgical site infections was 1.7% (n = 2), and the incidence of CSF leak was 0.8% (n = 1). In the control group (n = 117), the incidence of neurosurgical complications was 7.7% (n = 9), the incidence of surgical site infection was 2.6% (n = 3), and the incidence of CSF leak was 1.7% (n = 2). Sealant preparation time was less than 5 minutes in 96.6% of the PEG hydrogel group compared with 66.4% of controls (P < 0.001). The dural augmentation was applied in less than 1 minute in 85.7% of the PEG hydrogel group compared with 66.4% of the control group (P < 0.001). CONCLUSIONS: The PEG hydrogel dural sealant used in this study has a similar safety profile to commonly used dural sealing techniques when used as dural closure augmentation in cranial surgery. The PEG hydrogel dural sealant demonstrated faster preparation and application times than other commonly used dural sealing techniques.

Anatomic study of the prechiasmatic sulcus and its surgical implications.

To address a lack of anatomical descriptions in the literature regarding the prechiasmatic sulcus, we conducted an anatomical study of this sulcal region and discuss its clinical relevance to cranial base surgery. Our systematic morphometric analysis includes the variable types of chiasmatic sulcus and a classification schema that has surgical implications. We examined the sulcal region in 100 dry skulls; bony relationships measured included the interoptic distance, sulcal length/width, planum sphenoidale length, and sulcal angle. The varied anatomy of the prechiasmatic sulcii was classified as four types in combinations of wide to narrow, steep to flat. Its anterior border is the limbus sphenoidale at the posterior aspect of the planum sphenoidale. The sulcus extends posteriorly to the tuberculum sellae and laterally to the posteromedial aspect of each optic strut. Averages included an interoptic distance (19.3 +/- 2.4 mm), sulcal length (7.45 +/- 1.27 mm), planum sphenoidale length (19 +/- 2.35 mm), and sulcal angle (31 +/- 14.2 degrees). Eighteen percent of skulls had a chiasmatic ridge, a bony projection over the chiasmatic sulcus. The four types of prechiasmatic sulcus in our classification hold potential surgical relevance. Near the chiasmatic ridge, meningiomas may be hidden from the surgeon's view during a subfrontal or pterional approach. Preoperative evaluation by thin-cut CT scans of this region can help detect this ridge.

Maximizing the extent of tumor resection during transsphenoidal surgery for pituitary macroadenomas: can endoscopy replace intraoperative magnetic resonance imaging?

OBJECT: Endoscopic approaches to pituitary tumors have become an effective alternative to traditional microscopic transsphenoidal approaches. Despite a proven potential to decrease unexpected residual tumor, intraoperative MR (iMR) imaging is infrequently used even in the few operating environments in which such technology is available. Its use is prohibitive because of its cost, increased complexity, and longer operative times. The authors assessed the potential of intrasellar endoscopy to replace the need for iMR imaging without sacrificing the maximum extent of resection. METHODS: In this retrospective study, 27 consecutive patients underwent fully endoscopic resection of pituitary macroadenomas. Intrasellar endoscopy was used to determine the presence of residual tumor within the sella turcica and tumor cavity. Intraoperative MR imaging was used to identify rates of unexpected residual tumor and the need for further tumor resection. RESULTS: Intraoperative estimates of the extent of tumor resection were correct in 23 patients (85%). Of 4 patients with unacceptable tumor residuals, 3 underwent further tumor resection. After iMR imaging, the rate of successful completion of the planned extent of resection increased to 26 patients (96%). Rates of both endocrinopathy reversal and postoperative complications were consistent with previously published results for microscopic and endoscopic resection techniques. CONCLUSIONS: The findings in this study provided quantitative evidence that intrasellar endoscopy has significant promise for maximizing the extent of tumor resection and is a useful adjunct to surgical approaches to pituitary tumors, particularly when iMR imaging is unavailable. A larger prospective study on the extent of resection following endoscopic transsphenoidal surgery would strengthen these findings.

Delayed extrusion of hydroxyapatite cement after transpetrosal reconstruction.

OBJECTIVE: Use of hydroxyapatite cement has been advocated for closure of transpetrosal defects to decrease the incidence of cerebrospinal fluid leaks. We previously identified delayed extrusion of this cement as a significant complication associated with this closure technique and now update our long-term experience. METHODS: In our retrospective review, we identified 1231 patients who underwent transpetrosal procedures by our multidisciplinary cranial base team between 1984 and 2005. Of the subgroup of 177 patients who had hydroxyapatite cement used during the closure of the procedure, 13 patients (7.3%) experienced delayed extrusion of hydroxyapatite cement. RESULTS: Extrusion occurred in 3 patients within 12 months and in 10 patients within 68 to 140 months. Twelve patients presented with draining fistulae and concomitant Staphylococcus aureus infection; 1 patient presented asymptomatically with a large temporal lobe abscess identified on surveillance magnetic resonance imaging. All 13 patients underwent reoperation, including 1 who underwent a second procedure. CONCLUSION: Delayed extrusion of hydroxyapatite cement resulted in significant morbidity to our patients and often presented in an indolent manner. We recommend serial examination and imaging studies in patients who have had transpetrosal closures with hydroxyapatite cement. Because of the complication rates associated with hydroxyapatite cement, we have discontinued its use.

Extension of the one-piece orbitozygomatic frontotemporal approach to the glenoid fossa: cadaveric study.

OBJECTIVE: Resection of the glenoid fossa has been described as part of cranial approaches to the clivus and subtemporal approaches. However, radical resection carries a significant risk of postoperative temporomandibular joint dysfunction. We examine a simple variation of our previously described one-piece frontotemporal orbitozygomatic (FTOZ) osteotomy that adds en bloc resection of the root of the zygomatic arch and a portion of the glenoid fossa. METHODS: Five cadaveric fixed heads injected with colored silicone underwent an FTOZ osteotomy that extended to the root of the zygomatic arch and glenoid fossa. RESULTS: A step-by-step guide to the surgical technique is described, with illustrations to depict the glenoid fossa keyhole and bony cuts that free the zygomatic arch and portions of glenoid fossa. The first cut was made through the posterior root, and the second cut was made through the anterior root of the zygomatic arch. CONCLUSION: In this cadaveric study, extension of the one-piece FTOZ approach included the posterior root of the zygoma and the lateral part of the glenoid fossa. En bloc resection of the glenoid fossa and root of the zygomatic arch, together with the FTOZ osteotomy, facilitated reconstruction of the temporomandibular joint and increased the amount of exposure obtained with this FTOZ osteotomy. Comprehensive understanding of functional outcomes awaits further clinical study.

Evolution in the assessment and management of trigeminal schwannoma.

EDUCATIONAL OBJECTIVE: At the conclusion of this presentation, the participants should be able to understand the contemporary assessment and management algorithm used in the evaluation and care of patients with trigeminal schwannomas. OBJECTIVES: 1) Describe the contemporary neuroradiographic studies for the assessment of trigeminal schwannoma; 2) review the complex skull base osteology involved with these lesions; and 3) describe a contemporary management algorithm. STUDY DESIGN: Retrospective review of 23 cases. METHODS: Chart review. RESULTS: From 1984 to 2006, of 23 patients with trigeminal schwannoma (10 males and 13 females, ages 14-77 years), 15 patients underwent combined transpetrosal extirpation, 5 patients underwent stereotactic radiation, and 3 were followed without intervention. Of the 15 who underwent surgery, total tumor removal was achieved in 9 patients. Cytoreductive surgery was performed in six patients; of these, four received postoperative radiation. One patient who underwent primary radiation therapy required subsequent surgery. There were no deaths in this series. Cranial neuropathies were present in 14 patients pretreatment and observed in 17 patients posttreatment. Major complications included meningitis (1), cerebrospinal fluid leakage (2), major venous occlusion (1), and temporal lobe infarction (1). CONCLUSIONS: Trigeminal schwannomas are uncommon lesions of the skull base that may occur in the middle fossa, posterior fossa, or both. Moreover, caudal extension results in their presentation in the infratemporal fossa. Contemporary diagnostic imaging, coupled with selective use of both surgery and radiation will limit morbidity and allow for the safe and prudent management of this uncommon lesion.

Safety and efficacy of a novel polyethylene glycol hydrogel sealant for watertight dural repair.

OBJECT: The authors prospectively evaluated the safety and efficacy of a novel polyethylene glycol (PEG) hydrogel sealant in patients undergoing elective cranial surgery with documented cerebrospinal fluid (CSF) leakage after sutured dural repair. METHODS: The PEG hydrogel sealant was used at 11 different study sites in 111 patients with documented intraoperative CSF leakage after neurosurgical dural repair for a variety of conditions. Intraoperative CSF leakage was either spontaneous or induced by a Valsalva maneuver. Patients were monitored for 3 months postoperatively with physical examinations, clinical laboratory analyses, and diagnostic imaging. The PEG hydrogel sealant was 100% effective in stopping CSF leakage in all patients. There were no sealant-related adverse events and all clinical outcomes were consistent with expectations for seriously ill patients undergoing prolonged neurosurgical procedures. CONCLUSIONS: The PEG hydrogel sealant provides a safe and effective watertight closure when used as an adjunct to sutured dural repair during cranial surgery.

Facial paralysis and surgical rehabilitation: a quality of life analysis in a cohort of 1,595 patients after acoustic neuroma surgery.

OBJECTIVES: On the basis of survey results of the Acoustic Neuroma Association, we report patient ratings of facial dysfunction and outcomes for various facial rehabilitative therapies after surgical treatment of acoustic neuroma (AN). We assessed patients' perceived quality of life (QOL) and reviewed the literature regarding facial dysfunction and its management associated with AN. STUDY DESIGN: The Acoustic Neuroma Association mailed a detailed questionnaire to 2,372 members to identify preoperative and postoperative symptoms, complications, and long-term effects on physical and psychosocial function. A cohort of 1,595 (82.2%) respondents who underwent surgical treatment of ANs reported their experiences with facial dysfunction. PATIENTS: Of all 1,940 survey respondents, 1,682 of 1,875 that had ANs underwent surgical treatment. The study included 1,595 patients with ANs (82.2% of all respondents) who underwent surgical treatment by way of the translabyrinthine, suboccipital, or middle fossa approaches and excluded 87 respondents who did not report the type of surgical approach. METHODS: Respondents answered questions intended to qualify and quantify the degree that facial dysfunction impacted QOL parameters. Responses were analyzed for tumor size, surgical approach, patient age, and sex. Statistical analysis was performed using SPSS software. RESULTS: In our analysis, 11% of all respondents experienced some degree of preoperative facial weakness or eye problems. Of all respondents, 45.5% (725 patients) experienced worsened facial weakness caused by surgery, and of these, 72% reported that it was permanent. The most commonly used successful therapy for facial reanimation for 271 (19.6%) patients was placement of a gold weight. The factor most often associated with poor outcome was a large tumor. Of all respondents, 28% felt significantly affected by facial weakness, 63% felt their smile was symmetric, and 70% were content "quite a bit" or "very much" with their QOL. CONCLUSIONS: In this large cohort study of AN patients, facial dysfunction was a significant morbidity. Physicians should be aware of the risk factors identified, specifically large tumor size and the impact facial dysfunction has on QOL, when counseling patients regarding optimal management of AN.

Headache: a quality of life analysis in a cohort of 1,657 patients undergoing acoustic neuroma surgery, results from the acoustic neuroma association.

OBJECTIVES: On the basis of survey results of the Acoustic Neuroma Association (ANA), we report patient ratings of postoperative headache (POH) symptoms, determine its effect on quality of life (QOL), and review the literature regarding POH after acoustic neuroma (AN) treatment. STUDY DESIGN: In this cohort study, 1,657 patients who underwent surgical treatment of AN reported their experiences of POH. METHODS: A detailed questionnaire was mailed to members of the ANA to identify preoperative and postoperative headache symptoms, complications, and long-term effects on physical and psychosocial function. Questions were answered by 1657 (85.4%) respondents that were intended to qualify and quantify the effects of POH, including QOL issues. Responses were analyzed by tumor size, surgical approach, and patient age and sex. Statistical analysis was performed with the SPSS software. RESULTS: Preoperative headache was reported in approximately one third of respondents. Typical POHs occurred more than once daily (46%), lasted 1 to 4 hours in duration (43.1%), and were of moderate intensity (62.6%). The worst headaches were rated as "severe" by 77% of respondents. Treatment most often reported for typical headaches were nonprescription medications including nonsteroidal anti-inflammatory drugs in 61.3% (P < .01) and regular use of narcotics in 15%. Patients who underwent the retrosigmoid approach were significantly more likely to report their worst POH as "severe" (82.3%) compared with the translabyrinthine (75.2%) and middle fossa approaches (63.3%). Women and younger patients tended to have poorer outcomes with regard to POHs. CONCLUSIONS: In this large cohort study of AN patients, POH was a significant morbidity among AN patients with persistent headaches. Treating physicians should be aware of the risk factors identified and the effect POH has on the QOL when counseling patients regarding optimal treatment management.

Adaptation of a standard low-field (0.3-T) system to the operating room: focus on pituitary adenomas.

iMRI is a reliable and safe tool to monitor the extent of resection and to avoid complications in the transsphenoidal surgical approach for pituitary tumors. The best indication for its application in transsphenoidal surgery is for patients with pituitary macroadenomas with suprasellar extension. The low-field 0.3-T magnet has a diagnostic imaging quality that provides surgeons with good intraoperative detail of the anatomic relations in the sellar region. In our experience, iMRI provided a distinct benefit in planned STR for invasive macroadenomas that compress the optic chiasm and in planned GTR for noninvasive tumors. The iMRI design adopted at our center includes important features, such as the use of ferromagnetic surgical instruments, elimination of patient transportation, and capability as a shared resource, that allow multipurpose diagnostic use and increased cost-effectiveness.

Recurrence of cerebral arteriovenous malformations in children: report of two cases and review of the literature.

BACKGROUND: Angiography is considered the standard to assess the treatment success of cerebral arteriovenous malformations (AVMs). When postoperative angiograms show neither residual nidus nor early draining veins, patients are considered cured, and the risks of hemorrhage are eliminated. However, this notion is challenged by the development of recurrent AVMs in children. In our report, 2 children developed recurrent AVMs after undergoing complete resection, which was documented by postoperative angiography. We review other similar cases reported in the literature to help establish guidelines for postoperative monitoring. METHODS: In this retrospective review, 36 children underwent complete surgical resection of cerebral AVMs that were documented by intra- or postoperative angiography. After a follow-up period ranging from 1 to 17 years, rates of recurrence were assessed. RESULTS: Although angiographic documentation showed complete resection, 2 children developed recurrences 3 and 5 years later. Among these 36 children, the recurrence rate was 5.5% at follow-up (mean 9 years). CONCLUSIONS: Based on our data and review of the literature, intra- or early postoperative angiography is essential to exclude the presence of a residual nidus but does not ensure cure of the AVMs in children. If postoperative angiographic scans are obtained too early, postoperative changes may prevent the detection of a residual nidus. Therefore, we recommend that angiographic scans be obtained intraoperatively or early postoperatively to document complete resection and again at 1 and 5 years after surgical resection.

Patient perception of comorbid conditions after acoustic neuroma management: survey results from the acoustic neuroma association.

OBJECTIVES/HYPOTHESIS: Based on survey results of the Acoustic Neuroma Association, the patient ratings of the most difficult aspects of acoustic neuroma management were reported and a review of the literature was made regarding comorbid conditions associated with acoustic neuroma treatment and their impact on patient quality of life. STUDY DESIGN: Cohort study of 1940 patients who were members of the Acoustic Neuroma Association. METHODS: A detailed questionnaire was mailed to 2372 members of the Acoustic Neuroma Association to identify preoperative and postoperative symptoms, complications, and long-term effects on physical and psychosocial function. For 1940 respondents (81.8%) who reported the "most difficult aspect of the AN [acoustic neuroma] experience," the responses were analyzed by tumor size, surgical approach, and patient age and sex. Statistical analysis was performed using SPSS software. RESULTS: Respondents reported that the most difficult aspect of the acoustic neuroma experience was hearing loss (25.8%), followed by facial weakness (17.9%), eye problems (10.8%), and headache (10.5%). In order of frequency, men reported hearing loss, balance problems, perioperative surgical experience, and eye and facial weakness, and women reported hearing loss, facial weakness, eye problems, and headache. Facial weakness was a morbidity more often reported for men and women who had large tumors, who were young, or who had undergone the retrosigmoid approach. Balance dysfunction was significant in patients older than 75 years of age. In patients with small tumors, headaches and balance problems were frequently reported. CONCLUSION: In the large cohort study of patients with acoustic neuroma, perceptions regarding the impact of treatment illustrated why it is incumbent on physicians to understand the sentiments of patients with acoustic neuroma when counseling them and recommending optimal management strategies.

Large sphenoid wing meningiomas involving the cavernous sinus: conservative surgical strategies for better functional outcomes.

OBJECTIVE: The ability to resect meningiomas that involve the medial and anterior compartments of the cavernous sinus has been refuted. In this retrospective study, we determined the efficacy of total resection of meningiomas that invade the cavernous sinus but are restricted to the lateral compartment. METHODS: We reviewed the charts of 38 consecutive patients with sphenocavernous, clinoidocavernous, and sphenoclinoidocavernous meningiomas who underwent surgical treatment. We assessed early and late cranial nerve morbidity, extent of resection, and long-term outcome (mean, 96 mo). RESULTS: In all patients, tumors exceeded 3 cm diameter. In 22 of 24 patients, total microscopic excision was achieved in tumors that involved only the lateral compartment of the cavernous sinus and touched or partially encased the cavernous internal carotid artery (i.e., modified Hirsch Grades 0 and 1, respectively). In 2 of 24 patients, remaining tumor infiltrated the superior orbital fissure. All 14 patients who had tumors that encased (with or without narrowing) the cavernous segment of the internal carotid artery (Hirsch Grades 2-4) underwent incomplete resection. Among 38 patients, mortality was 0%, late cranial nerve deficits remained in 6 (16%), and late Karnofsky Performance Scale scores exceeded 90 in 34 patients (90%). Four patients (10.5%) developed a recurrence or regrowth. Of 20 patients who were treated with either linear accelerator-based stereotactic radiosurgery or fractionated conformal radiotherapy, 11 had residual tumor and a moderate to high proliferative index, 4 had atypical tumors and 1 had angioblastic meningioma after total excision, 2 had regrowth, and 2 had recurrent tumors. In 18 (90%) of the 20 patients who underwent radiation, tumor size was reduced or controlled. CONCLUSION: On the basis of this study and a review of the literature, we demonstrate that sphenocavernous, clinoidocavernous, and sphenoclinoidocavernous meningiomas of Hirsch Grades 0 and 1 can be excised from the lateral compartment of the cavernous sinus without postoperative mortality and with acceptable rates of morbidity. Residual tumor in the medial compartment (Hirsch Grades 2-4) may be treated with some form of radiation therapy or observation.

Intradural aneurysm arising from the posterior genu of the cavernous carotid artery mimicking a posterior communicating aneurysm: case report.

OBJECTIVE AND IMPORTANCE: We present a rare case of an intradural aneurysm that arose from the posterior genu of the cavernous carotid artery and was diagnosed via angiography as originating from the internal carotid artery (ICA) at the level of the posterior communicating artery. Our review of the English-language literature found no other case of an intradural aneurysm that originated at the posterior genu of the cavernous ICA. CLINICAL PRESENTATION: A 65-year-old woman presented with increasingly severe left retro-orbital headaches. Her family history included aneurysmal subarachnoid hemorrhage. Angiography revealed an 11-mm aneurysm, which was interpreted as arising from the left ICA at the level of the posterior communicating artery. INTERVENTION: During a left pterional craniotomy, an aneurysm was identified underneath the oculomotor nerve; its neck seemed to arise from the posterior communicating artery segment. Despite clipping of the aneurysm attachment to the ICA and trapping of the posterior communicating segment, the aneurysm continued to fill. Further dissection revealed that the aneurysm's neck originated from the cavernous ICA. Placement of fenestrated clips around the oculomotor nerve successfully occluded the intradural portion of the aneurysm, as documented by an intraoperative angiogram. CONCLUSION: We discuss this unique case to draw attention to the importance of the interpretation and adequacy of preoperative angiography, and we review pertinent vascular anatomy.

Malignant squamous degeneration of a cerebellopontine angle epidermoid tumor. Case report.

The authors present the case of a woman with a cerebellopontine angle (CPA) epidermoid cyst that degenerated into a squamous cell carcinoma. Malignant degeneration of an epidermoid cyst is an extremely rare occurrence. Malignant transformation must be considered in the differential diagnosis when new contrast enhancement on imaging studies and progressive neurological deficit are seen in a patient harboring an epidermoid cyst. The patient initially presented with a 10-year history of left trigeminal neuralgia, subacute left-sided hearing loss, and with facial weakness of 3 weeks' duration. Initial magnetic resonance (MR) imaging revealed a left CPA mass, consistent with an epidermoid. There was faint contrast enhancement where the tumor was in contact with the lateral brainstem. A subtotal resection was performed. Histopathological findings were consistent with an epidermoid tumor. One year after initial presentation, the patient's neurological deficit had increased, and follow-up MR imaging demonstrated a large contrast-enhancing tumor filling the left CPA and compressing the brainstem. At repeated surgery a squamous cell carcinoma arising from the previous epidermoid was found. The patient was subsequently treated with external-beam radiotherapy and stereotactic radiosurgery. Her tumor stabilized. Three years and 8 months after the patient's initial presentation, a new area of tumor developed at the torcular Herophili. The patient died shortly thereafter. Malignant squamous degeneration is a rare cause of enhancement on MR images, as is progressive neurological deficit in a patient with an epidermoid. The combination of subtotal resection, external-beam radiotherapy, and stereotactic radiosurgery may be useful for local tumor control but the long-term prognosis is guarded.

Indications for endovascular therapy for refractory vasospasm after aneurysmal subarachnoid hemorrhage: experience at the University of Cincinnati.

BACKGROUND: Transluminal balloon angioplasty (TBA) and intra-arterial papaverine (IAP) appear to be valuable alternatives for the treatment of aneurysmal subarachnoid hemorrhage (SAH)-induced vasospasm refractory to maximal medical therapy. Although widely used, guiding principles for the implementation of TBA and IAP are not yet established. Based on our retrospective analysis, we define guidelines for endovascular therapy for refractory vasospasm based on our clinical results, adverse effects, and pattern of vasospasm. METHODS: Medical records of 62 patients who experienced aneurysmal SAH-induced vasospasm refractory to hypervolemic, hypertensive, hyperdynamic therapy, and who were treated with IAP or TBA were reviewed. Fifty patients met the inclusion criteria for analysis. After careful scrutiny, two types of responses to endovascular treatment were identified. On the basis of that grouping, patients were divided into two groups according to the number of arterial segments involved, that is, monoterritorial and multiterritorial vasospasm. Multiple variables were analyzed. RESULTS: Patients undergoing multiple endovascular procedures exhibited the worst outcomes. Patients in the monoterritorial group experienced a higher incidence of clinical improvement and better outcomes after endovascular treatment. Elevated intracranial pressure (ICP) and ICP-related deaths were more prominent in the multiterritorial group of patients. Sustained ICP elevation after administration of IAP was strongly associated with poor outcome in the multiterritorial group. CONCLUSIONS: IAP is indicated as an early potential single-dose infusion in distal monoterritorial vasospasm, if angioplasty is impossible or unsafe. The use of IAP in bilateral diffuse vasospasm is discouraged because of the high susceptibility of these patients to develop elevated ICP. Multiple IAP infusions seem to have no significant impact on patient outcome. Balloon angioplasty seems to be indicated at an early juncture in patients with multiterritorial proximal vasospasm.

Acute foramen magnum syndrome caused by an acquired Chiari malformation after lumbar drainage of cerebrospinal fluid: report of three cases.

OBJECTIVE AND IMPORTANCE: The perioperative use of lumbar drainage of cerebrospinal fluid (CSF) is relatively common in neurosurgery, and the development of "acquired" Chiari malformations (tonsillar herniation) with lumbar CSF diversion procedures has been reported. CLINICAL PRESENTATION: We describe the history of three patients who developed a foramen magnum syndrome, attributable to acquired Chiari I malformations, after perioperative lumbar drainage of CSF. CONCLUSION: We propose that the mechanism responsible for Chiari I malformations involves a negative pressure gradient between the cranial and spinal regions, created by CSF drainage. Theories regarding the formation of acquired Chiari I malformations, the possible synergistic roles of intracranial pathological conditions and CSF drainage in the development of this entity, and the implications for the use of perioperative lumbar drainage are discussed.