Search

Abstract Background Human papillomavirus (HPV) causes cervical cancer and external genital warts. The purpose of this study is to document the genotype distribution of HPV in females aged between 18 and 34 who self-referred to an STI clinic with visible external genital warts (EGW). Scrapings were taken from visible external genital warts (EGW). These scrapings were analysed by PCR for the presence of HPV DNA. Positive samples were then genotyped by means of a commercially available assay (LiPA). A comparison of genotyping results determined by the LiPA assay and direct amplicon DNA sequencing was also performed. Results Ninety-two patients out of 105 samples (88%) had detectable levels of HPV DNA. The majority of individuals with EGW (66%) showed the presence of two or more genotypes. The most common HPV genotypes present in the study population were HPV-6, HPV-11, HPV-16, HPV-18, HPV-33 and HPV-53. Potential effects of vaccination on HPV molecular epidemiology indicate that 40% of the patients could have been protected from the high risk genotypes HPV-16 and HPV-18. Conclusion This is the first report of the molecular epidemiology of external genital warts in women aged between 18 and 34 from Ireland based on results from a LiPA assay. The study shows that most individuals are infected with multiple genotypes including those with high oncogenic potential and that the newly available HPV vaccines could have a significant impact on prevalence of the most common HPV genotypes in this study population.

Introduction: The UNIPLATE was developed to improve operative times and limit dissection at the lateral margins of the vertebral bodies. The distinguishing character of this plate is its thin design, which requires only one screw per vertebral level (monovertebral screw plate). Most cervical spine plates, in contrast, are designed for two screws per vertebral level (bivertebral screw plate). Limited reports of the biomechanical efficacy of the UNIPLATE are available, and to the authors' knowledge, this report represents the largest clinical study of its use., Methods: This is a retrospective chart-review study of consecutively treated patients without previous cervical spine surgery undergoing anterior cervical diskectomy and fusion at one or two levels. The primary end point was symptomatic pseudarthrosis requiring revision surgery. Pseudarthrosis is defined as a failure of bony fusion on the operated level seen on thin-cut computed tomography scans performed on symptomatic patients. The rate of revision surgery caused by symptomatic pseudarthrosis was compared between patients undergoing one- and two-level fusion surgeries treated with UNIPLATE compared with other plates with two screws per vertebral level. The minimum follow-up was 18 months., Results: A total of 162 patients were identified, including 125 patients with one-level fusion and 37 patients with two-level fusion surgery. The median follow-up period was 3.3 years. A significantly greater incidence (odds ratio 10.2, P = 0.042) of reoperation for symptomatic pseudarthrosis was noted for patients treated with the UNIPLATE (4 of 13, 31%) compared with patients treated with bivertebral screw plates (1 of 24, 2.5%). No significant difference in reoperation attributable to symptomatic pseudarthrosis was noted for different plating systems for one-level fusion surgeries., Conclusions: There is an increased rate of reoperation for symptomatic pseudarthrosis after anterior cervical diskectomy and fusion surgery with the use of a monovertebral screw semiconstrained plate, particularly in two-level fusion surgeries. Use of the UNIPLATE system has since been abandoned at our institution in favor of bivertebral screw plating systems., (Copyright © 2014. Published by Elsevier Inc.)

Background: In 2003 the Accreditation Council for Graduate Medical Education implemented duty-hour restrictions for residents, with an unclear impact on patient care., Objective: The authors hypothesize that implementation of duty-hour restrictions is not associated with decreased morbidity for neurosurgical patients. This hypothesis was tested with the Nationwide Inpatient Sample to examine inpatient complications associated with a common elective procedure, craniotomy for meningioma., Methods: The Nationwide Inpatient Sample was queried for all patients admitted for elective craniotomy for meningioma from 1998 to 2008, excluding the year 2003. Each case was queried for common in-hospital postoperative complications. The complication rate was compared for 5-year epochs at teaching and nonteaching hospitals before (1998-2002) and after (2004-2008) the adoption of the Accreditation Council for Graduate Medical Education work-hour restriction. Multivariate analysis was performed to control for the effects of age and medical comorbidities., Results: We identified 21177 patients who met inclusion criteria. We identified an effect of age, preexisting medical comorbidity, and timing of surgery on postoperative complication rates. At teaching hospitals, the complication rate increased from 14% to 16% (P < .001). In contrast, this increase was not mirrored at nonteaching hospitals, which saw a nearly constant postoperative complication rate of 15% from 1998 to 2002 and 15% for the years 2004 to 2008 (P = .979). This effect remained significant in a multivariate analysis including age and existing comorbidities as covariates (P = .016)., Conclusion: In patients undergoing craniotomy for meningioma, postoperative complication rates increased at teaching hospitals, but not at nonteaching hospitals over the 5-year epochs before and after 2003.

Purpose: The authors aimed to trial an alternative interviewing strategy by inviting residency candidates to our surgical anatomy laboratory. Interviews were coincident with surgical dissection. The authors hypothesized that residency candidates hoping to match into a surgical subspecialty might enjoy this unconventional interviewing strategy, which would mimic an operating room experience., Methods: On scheduled residency interview dates, formal, unstructured interviews were held with half of the neurosurgical faculty, and unstructured surgical skills laboratory-based interviews were held with the other half of the neurosurgical faculty. Interviews in the skills laboratory featured cases and corresponding surgical dissection guided by faculty. After the interview, the residency candidates were encouraged to complete an optional survey about their interview process. The survey results were pooled for analysis., Results: Of 28 interviewed, 19 individuals responded to the survey. The survey respondents had favorable reviews of the all aspects of the interview process. When asked to report the most enjoyable part of the interview, all respondents listed the surgical skills laboratory. The average respondent scores for importance of the surgical skills laboratory interview (9.5 ± 1.1) compared with conventional interview with faculty (9.2 ± 1.0) or residents (9.1 ± 1.0) was not significantly different (p = 0.50, analysis of variance)., Conclusions: The surgical skills laboratory interviews were reviewed favorably by the survey respondents. Nearly all respondents listed the surgical skills interview as the most enjoyable part of the interview experience. The authors advocate this residency interview strategy for surgical subspecialty residencies., (Copyright © 2011 Association of Program Directors in Surgery. Published by Elsevier Inc. All rights reserved.)

Object: The Accreditation Council for Graduate Medical Education instituted mandatory 80-hour work-week limitations in July 2003. The work-hour restriction was met with skepticism among the academic neurosurgery community and is thought to represent a barrier to teaching, ultimately compromising patient care. The authors hypothesize that the introduction of the mandatory resident work-hour restriction corresponds with an overall increase in morbidity rate., Methods: This study compares the morbidity and mortality rates on an academic neurological surgery service before and after institution of the work-hour restriction. Complications are individually assessed at a monthly divisional conference by neurosurgical faculty and residents. A prospective database was commenced in July 2000 recording all complications, complications that were deemed to be potentially avoidable ("possibly preventable"), and complications that were deemed unavoidable. The incidence of morbidity and mortality from July 2000 to June 2003 is compared with the incidence from July 2003 to June 2006., Results: The overall rate of morbidity and mortality increased from 103 to 114 per 1000 patients treated after institution of the work-hour restriction, although this increase was not statistically significant (χ(2)(1, N = 8546) = 2.6, p = 0.106). The morbidity rate increased from 70 to 89 per 1000 patients treated after institution of the work-hour restriction (χ(2)(1, N = 8546) = 10, p = 0.001). The overall mortality rate was diminished from 32 to 27 per 1000 patients treated after institution of the work-hour restriction (χ(2)(1, N = 8546) = 3.2, p = 0.075). Morbidities considered avoidable or possibly preventable were seen to increase from 56 to 66 per 1000 patients treated (χ(2)(1, N = 8546) = 5.7, p = 0.017). Avoidable or possibly preventable mortalities numbered 3 per 1000 patients treated, and this rate did not change after introduction of the work-hour restriction (χ(2)(1, N = 8546) = 0.08, p = 0.777)., Conclusions: The morbidity rate on a neurological surgery service is increased after implementation of the work-hour restriction. Mortality rates remain unchanged.

Object: Microvascular decompression (MVD) offers an effective and durable treatment for patients suffering from trigeminal neuralgia (TN). Because the disorder has a tendency to occur in older persons, the risks of surgical treatment in the elderly have been a topic of recent interest. To date, evidence derived from several small retrospective and a single prospective case series has suggested that age does not increase the complication rate associated with surgery. Using a large national database, the authors aimed to study the impact of age on in-hospital complications following MVD for TN., Methods: Using the Nationwide Inpatient Sample (NIS) for the 10-year period from 1999 to 2008, the authors selected all patients who underwent MVD for TN. The primary outcome of interest was the in-hospital mortality rate. Secondary outcomes of interest were cardiac, pulmonary, thromboembolic, cerebrovascular, and wound complications as well as the duration of hospital stay, total hospital charges, and discharge location. An elderly cohort of patients was first defined as those 65 years of age and older and then redefined as those 75 years and older., Results: A total of 3273 patients who underwent MVD for TN were identified, having a median age of 57 years. Within this sample, 31.5% were 65 years and older and 10.7% were 75 years and older. The in-hospital mortality rate was 0.68% for patients 65 years or older (p = 0.0087) and 1.16% for those 75 years or older (p = 0.0026). In patients younger than 65 years, the in-hospital mortality rate was 0.13% (3 deaths among 2241 patients). As analyzed using the chi-square test (for both 65 and 75 years as the age cutoff) and the Pearson rank correlation coefficient, the risk of cardiac, pulmonary, thromboembolic, and cerebrovascular complications was higher in older patients (that is, those 65 and older and those 75 and older), but the risks of wound complications and CNS infection were not. The risk of any in-hospital complication occurring in a patient 65 years and older was 7.36% (p < 0.0001) and 10.0% in those 75 years and older (p < 0.0001). There was no difference in the total hospital charges associated with age. The duration of the hospital stay was longer in older patients, and the likelihood of discharge home was lower in older patients., Conclusions: Microvascular decompression for TN in the elderly population remains a reasonable surgical option. However, based on data from a large national database, authors of the present study suggest that complications do tend to gradually increase in tandem with an advanced age. While age does not act as a risk factor in isolation, it may serve as a convenient surrogate for complication rates. The authors hope that this information can be of use in guiding older patients through decisions for the surgical treatment of TN.

Pneumosinus dilitans (PSD) is enlargement of the sinuses of the skull base and is frequently seen with meningiomas. Identifying PSD on imaging can assist with operative planning and preparation. Meningiomas associated with PSD are not more commonly high grade, and complete resection is frequently possible.

Object: Helmet use has been associated with fewer hospital visits among injured skiers and snowboarders, but there remains no evidence that helmets alter the intracranial injury patterns. The authors hypothesized that helmet use among skiers and snowboarders reduces the incidence of head injury as defined by findings on head CT scans., Methods: The authors performed a retrospective review of head-injured skiers and snowboarders at 2 Level I trauma centers in New England over a 6-year period. The primary outcome of interest was intracranial injury evident on CT scans. Secondary outcomes included the following: need for a neurosurgical procedure, presence of spine injury, need for ICU admission, length of stay, discharge location, and death., Results: Of the 57 children identified who sustained a head injury while skiing or snowboarding, 33.3% were wearing a helmet at the time of injury. Of the helmeted patients, 5.3% sustained a calvarial fracture compared with 36.8% of the unhelmeted patients (p = 0.009). Although there was a favorable trend, there was no significant difference in the incidence of epidural hematoma, subdural hematoma, intraparenchymal hemorrhage, subarachnoid hemorrhage, or contusion in helmeted and unhelmeted patients. With regard to secondary outcomes, there were no significant differences between the 2 groups in percentage of patients requiring neurosurgical intervention, percentage requiring admission to an ICU, total length of stay, or percentage discharged home. There was no difference in the incidence of cervical spine injury. There was 1 death in an unhelmeted patient, and there were no deaths among helmeted patients., Conclusions: Among hospitalized children who sustained a head injury while skiing or snowboarding, a significantly lower number of patients suffered a skull fracture if they were wearing helmets at the time of the injury.

Object: The authors describe the artificial neural network (ANN) as an innovative and powerful modeling tool that can be increasingly applied to develop predictive models in neurosurgery. They aimed to demonstrate the utility of an ANN in predicting survival following traumatic brain injury and compare its predictive ability with that of regression models and clinicians., Methods: The authors designed an ANN to predict in-hospital survival following traumatic brain injury. The model was generated with 11 clinical inputs and a single output. Using a subset of the National Trauma Database, the authors "trained" the model to predict outcome by providing the model with patients for whom 11 clinical inputs were paired with known outcomes, which allowed the ANN to "learn" the relevant relationships that predict outcome. The model was tested against actual outcomes in a novel subset of 100 patients derived from the same database. For comparison with traditional forms of modeling, 2 regression models were developed using the same training set and were evaluated on the same testing set. Lastly, the authors used the same 100-patient testing set to evaluate 5 neurosurgery residents and 4 neurosurgery staff physicians on their ability to predict survival on the basis of the same 11 data points that were provided to the ANN. The ANN was compared with the clinicians and the regression models in terms of accuracy, sensitivity, specificity, and discrimination., Results: Compared with regression models, the ANN was more accurate (p < 0.001), more sensitive (p < 0.001), as specific (p = 0.260), and more discriminating (p < 0.001). There was no difference between the neurosurgery residents and staff physicians, and all clinicians were pooled to compare with the 5 best neural networks. The ANNs were more accurate (p < 0.0001), more sensitive (p < 0.0001), as specific (p = 0.743), and more discriminating (p < 0.0001) than the clinicians., Conclusions: When given the same limited clinical information, the ANN significantly outperformed regression models and clinicians on multiple performance measures. While this paradigm certainly does not adequately reflect a real clinical scenario, this form of modeling could ultimately serve as a useful clinical decision support tool. As the model evolves to include more complex clinical variables, the performance gap over clinicians and logistic regression models will persist or, ideally, further increase.

Object: The Subdural Evacuating Port System (SEPS) was recently introduced as a novel method of treating chronic subdural hematomas (SDHs). This system is a variation of the existing twist-drill craniostomy methods for treating chronic SDH. Compared with craniotomy or bur hole treatment of chronic SDH, this system offers the possibility of treatment at bedside without general anesthesia. In comparison with existing twist-drill methods, the system theoretically offers the advantage of a hermetically closed system that can evacuate a hematoma without an intracranial catheter., Methods: The authors performed a case-control study of all chronic SDHs treated at a single institution over a 5-year period and compared the efficacy and safety of the SEPS to bur hole evacuation. Patients were matched for age, injury mechanism, medical comorbidities, use of anticoagulation, and radiographic appearance of the SDH. The primary outcome of interest was the recurrence rate in each group, which was evaluated by radiographic evidence as well as the number of patients requiring a second procedure. Secondary outcomes examined were mortality, infection, acute hematoma formation, seizure, length of hospital stay, length of intensive care unit stay, and discharge location., Results: The authors found that there were no appreciable differences in symptoms on presentation, existing comorbidities, home medications, or laboratory values between the treatment groups. The average Hounsfield units of preoperative CT scanning was similar in both groups. Radiographic recurrence was statistically similar between the SEPS group (25.9%) and the bur hole group (18.5%; p = 0.37). Although there was a trend toward higher reoperation rates in the SEPS group, the need for a subsequent procedure was also statistically similar between the SEPS group (25.9%) and the bur hole group (14.8%; p = 0.25). The mortality rate was not significantly different between the SEPS group (9.5%) and the bur hole group (4.8%; p = 0.50). The SEPS procedure provided a mean reduction in SDH thickness of 27.3% compared with 37.9% with bur hole (p = 0.05) when comparing the preoperative CT scan with the first postoperative CT scan. The percentage of reduction in SDH thickness when comparing the preoperative CT scan with the most recent postoperative CT scan was 40.5% in the SEPS group and 45.4% in the bur hole group (p = 0.31)., Conclusions: The SEPS offers an alternative type of twist-drill craniostomy for the treatment of chronic SDH with a trend toward higher recurrence in our experience. The efficacy and safety of SEPS is similar to that of other twist-drill methods reported in the literature. In the authors' experience, the efficacy of this treatment as measured by radiographic worsening or the need for a subsequent procedure is statistically similar to that of bur hole treatment. There was no difference in mortality or other adverse outcomes associated with SEPS.

Raymond M. P. Donaghy was one of the true pioneers of modern neurosurgery. His restless dedication, innovation, and desire to humbly disseminate his knowledge facilitated the advancement of the field of microneurosurgery. Many of his trainees--most notably M. Gazi Yaşargil--continued to advance the field, developing innovative microsurgical instruments and techniques. The history of microneurosurgery is incomplete without a glimpse at the life of this remarkable man.

Patients with occlusive cerebrovascular disease who have failed maximal medical therapy, which consists of antiplatelet agents as well as maximizing modifiable risk factors such as blood pressure, cholesterol, smoking cessation, and obesity, and whose lesions are not amenable or have not responded to the more common vascular procedures (i.e., carotid endarterectomy or stenting) are considered candidates for an extracranial-intracranial bypass. Additionally, for a patient to be a candidate, he/she must have an adequate graft vessel. Typically, this vessel is the superficial temporal artery. However, oftentimes, the superficial temporal artery is an inadequate vessel or the patient requires a high-flow conduit. It is in these patients that use of the saphenous vein should be considered. In this report, we detail the technical aspects of performing an extracranial-intracranial bypass by using a saphenous vein graft.

Objective: We studied the hearing results and outcomes after transcrusal craniotomy., Study Design: We conducted a retrospective review., Setting: This study was conducted at a tertiary care hospital., Patients: We studied 10 consecutive patients, including two men and eight women, who underwent transcrusal craniotomy for petroclival masses or tumors., Intervention: The intervention consisted of therapeutic removal of petroclival meningioma., Main Outcome Measure: The main outcome measure of this study was hearing preservation as measured by standard audiogram., Results: There were six meningiomas, one eighth nerve schwannoma, one fifth nerve schwannoma, one chordoma, and one midbasilar artery aneurysm. Postoperative hearing was measured according to the AAOHNS criteria. Complications and further therapies were recorded. Postoperative hearing was measured in eight. The cochlear nerve was severed in one patient. One was unavailable for follow up. Eight patients retained hearing at or near preoperative levels, seven with SRT within 10 dB and speech discrimination within 10% of preoperative levels. Four patients presented with trigeminal symptoms, one with third nerve palsy and two with facial weakness. Postoperative deficits included fourth, sixth, seventh, and eighth nerve palsies in three patients. Complications included one wound infection, two cerebrospinal fluid leak, and two cases of meningitis, both of which were sterile. There were secondary procedures in five patients-three radiosurgery, two shunts, one tracheotomy, and one g-tube., Conclusions: Transcrusal craniotomy is a safe and effective approach to the petroclival region. Excellent hearing results can be expected with this technique.

Objective: This study was designed to quantify the operative exposure obtained in the pterional, orbitozygomatic, and modified orbitozygomatic with maxillary extension surgical approaches., Methods: The pterional and orbitozygomatic approaches and a variation of the orbitozygomatic osteotomy that included an extra centimeter of bone resection in the inferior direction ("maxillary extension") were performed on cadaveric heads. For each surgical exposure, the working area was determined by using triangles defined with anatomic points. The "angle of attack" of the approaches for the same target point was determined with the use of a robotic microscope., Results: The maximum allowable angle of attack was significantly greater with the orbitozygomatic approach (37.2 +/- 4.7 degrees) than that with the pterional approach (27.1 +/- 4.3 degrees) (P < 0.001). The angle of attack with the maxillary extension (42.0 +/- 4.9 degrees) was significantly greater than that with the orbitozygomatic approach (P < 0.001). The working areas were 281, 343, and 371 mm(2) for the pterional, orbitozygomatic, and maxillary extension approaches, respectively. The orbitozygomatic approach with maxillary extension had a significantly larger working area than the pterional approach (P = 0.011)., Conclusion: Increments in bony removal open a wider angle in which to work more than they increase the actual amount of working area. Increasing the amount of bone removed by using an orbitozygomatic approach instead of a pterional approach converts a narrow space into a wide portal, allowing surgeons to work closer to the surgical target while decreasing the need for brain retraction. Extending the orbitozygomatic approach into the maxillary region also improves the exposure area and angle, but less significantly.

Objective: The outcomes of surgery for acoustic neuromas have improved dramatically since the development of modern surgical techniques, the operating microscope, magnetic resonance imaging (MRI), and cranial nerve monitoring. The goals of acoustic neuroma surgery are now preservation of facial nerve function and, when feasible, hearing preservation. Many large series do not report standardized hearing and facial function grading, and they include patients who did not benefit from the most modern techniques. The purpose of this study was to present the results of acoustic neuroma surgery using the most modern techniques and equipment, using standardized grading systems., Study Design: Retrospective review., Setting: Tertiary referral center., Patients: 97 patients who underwent surgical removal of acoustic neuromas from 1992 to 1998., Intervention: All patients underwent acoustic neuroma surgery and had preoperative audiograms and MRI with contrast. In addition, all patients had preoperative and postoperative facial function graded by the House-Brackmann scale and intraoperative facial nerve monitoring. Hearing preservation was attempted in patients with tumors of any size who had preoperative function of grade A or B according to the Committee on Hearing and Equilibrium guidelines for reporting results of acoustic neuroma surgery., Main Outcome Measures: Hearing preservation was considered successful if the patient retained serviceable hearing grade A or B. House-Brackmann grade 1 or 2 was considered excellent facial function. Complications were recorded., Results: Facial nerve integrity was preserved in 96 of 97 patients (99%). Eight of 8 (100%) patients with intracanalicular tumors had excellent facial nerve function (HB 1-2). Fifty-two of 55 (95%) of patients with small tumors had excellent facial nerve function, and 15 of 24 (63%) with medium tumors had HB grade 1-2. Hearing was preserved in 29% of patients with tumors under 2 cm. The overall complication rate was 20%; cerebrospinal fluid leak was the most common., Conclusion: These results show that with modern imaging and surgical techniques, acoustic neuroma surgery is extremely safe and outcomes are very good. Surgery remains the treatment of choice for most tumors until alternative therapies, such as gamma knife, use uniform grading scales and show long-term facial and hearing results.

As a term, the "petrosal approach" to the petroclival region has a variety of meanings. The authors define a common nomenclature based on historical contributions and add new terminology to describe a technique of hearing preservation that allows for greater exposure of the petroclival region. The degree of temporal bone dissection defines five stages of operation. The authors used the second or "transcrusal" stage, in which the posterior and superior semicircular canals are sacrificed while preserving hearing, in six consecutive cases. Use of a common terminology ensures better understanding among surgeons. In the authors' hands, hearing has been successfully preserved in six patients after partial labyrinthectomy.

Object: The petrosal approach to the petroclival region has been used by a variety of authors in various ways and the terminology has become quite confusing. A systematic assessment of the benefits and limitations of each approach is also lacking. The authors classify their approach to the middle and upper clivus, review the applications for each, and test their hypotheses on a cadaver model by using frameless stereotactic guidance., Methods: The petrosal approach to the upper and middle clivus is divided into four increasingly morbidity-producing steps: retrolabyrinthine, transcrusal (partial labyrinthectomy), transotic, and transcochlear approaches. Four latex-injected cadaveric heads (eight sides) underwent dissection in which frameless stereotactic guidance was used. An area of exposure 10 cm superficial to a central target (working area) was calculated. The area and length of clival exposure with each subsequent dissection was also calculated. The retrolabyrinthine approach spares hearing and facial function but provides for only a small window of upper clival exposure. The view afforded by what we have called the transcrusal approach provides for up to four times this exposure. The transotic and transcochlear procedures, although producing more morbidity, add little in terms of a larger clival window. However, with each step, the surgical freedom for manipulation of instruments increases., Conclusions: The petrosal approach to the upper and middle clivus is useful but should be used judiciously, because levels of morbidity can be high. The retrolabyrinthine approach has limited utility. For tumors without bone invasion, the transcrusal approach provides a much more versatile exposure with an excellent chance of hearing and facial nerve preservation. The transotic approach provides for greater versatility in treating lesions but clival exposure is not greatly enhanced. Transcochlear exposure adds little in terms of intradural exposure and should be reserved for cases in which access to the petrous carotid artery is necessary.

Object: The purpose of this study was to evaluate the far-lateral transcondylar transtubercular approach (complete FLA) based on quantitative measurements of the exposure of the foramen magnum and petroclival area obtained after each successive step of this approach., Methods: The complete FLA was reproduced in eight specially prepared cadaveric heads (a total of 15 sides). The approach was divided into six steps: 1) C-1 hemilaminectomy and suboccipital craniectomy with unroofing of the sigmoid sinus (basic FLA); 2) partial resection of the occipital condyle (up to the hypoglossal canal); 3) removal of the jugular tuberculum; 4) mastoidectomy (limited to the labyrinth and the fallopian canal) and retraction of the sigmoid sinus; 5) resection of the lateral mass of C-1 with mobilization of the vertebral artery; and 6) resection of the remaining portion of the occipital condyle. After each successive step, a standard set of measurements was obtained using a frameless stereotactic device. The measurements were used to estimate two parameters: the size of the exposed petroclival area and the size of a spatial cone directed toward the anterior rim of the foramen magnum, which depicts the amount of surgical freedom available for manipulation of instruments. The initial basic FLA provided exposure of only 21 +/- 6% of the petroclival area that was exposed with the full, six-step maximally aggressive (complete) FLA. Likewise, only 18 +/- 9% of the final surgical freedom was obtained after the basic FLA was performed. Each subsequent step of the approach increased both petroclival exposure and surgical freedom. The most dramatic increase in petroclival exposure was noted after removal of the jugular tuberculum (71 +/- 12% of final exposure), whereas the least improvement in exposure occurred after the final step, which consisted of total condyle resection., Conclusions: The complete FLA provides wide and sufficient exposure of the foramen magnum and lower to middle clivus. The complete FLA consists of several steps, each of which contributes to increasing petroclival exposure and surgical freedom. However, the FLA may be limited to the less aggressive steps, while still achieving significant exposure and surgical freedom. The choice of complete or basic FLA thus depends on the underlying pathological condition and the degree of exposure required for effective surgical treatment.

Object: Use of orbital rim and orbitozygomatic osteotomy has been extensively reported to increase exposure in neurosurgical procedures. However, there have been few attempts to quantify the extent of additional exposure gained by these maneuvers. Using a novel laboratory technique, the authors have attempted to measure the increase in the "area of exposure" that is gained by removal of the orbital rim and zygomatic arch via the frontotemporal transsylvian approach., Methods: The authors dissected five cadavers bilaterally. The area of exposure provided by the frontotemporal transsylvian approach was determined by using a frameless stereotactic device. With the tip of a microdissector placed on targets deep within the exposure, the position of the end of the microdissector handle was measured in three-dimensional space as the microdissector was rotated around the periphery of the operative field. This maneuver was performed via the frontotemporal approach alone as well as with orbital rim and orbitozygomatic osteotomy approaches. After data manipulation, the areas of exposure corresponding to the polygons used to define these handle positions were calculated and directly compared. On average, the area of exposure provided by the frontotemporal transsylvian approach was increased 26 to 39% (p<0.05) by adding orbital rim osteotomy and an additional 13 to 22% (not significant) with removal of the zygomatic arch., Conclusions: Significant and consistent increases in surgical exposure were obtained by using orbital osteotomy, whereas zygomatic arch removal produced less consistent gains. Both maneuvers may be expected to improve surgical access. However, because larger and more consistent gains were afforded by orbital rim removal, the threshold for removal of this portion of the orbitozygomatic complex should be lower.

Techniques for operative management for type II odontoid fractures have continuously been refined with anterior odontoid screw arthrodesis having a clear advantage in maintaining normal motion. We have refined the technique of odontoid screw fixation further with the introduction of an endoscopic approach developed by the senior author. The necks of two partially embalmed cadavers were slightly extended under fluoroscopic guidance to simulate a reduced, anteriorly displaced type II fracture. Using a guide wire, graduated plastic sheath and endoscopic guidance, a solid 45 mm bone screw was passed through the odontoid with the aid of biplanar fluoroscopy. There were no apparent complications and no damage to surrounding vital structures. Anterior screw fixation of the odontoid is an established technique that provides adequate fixation, but the procedure can be technically demanding secondary to awkward tissue retraction. We present a percutaneous technique that obviates the need for tissue retraction while achieving an excellent result with only a modicum of effort.

Fibrous dysplasia is a benign, developmental bone disorder of unknown aetiology. With involvement of the facial bones, indications for surgical intervention include cosmetic deformity and/or progressive neurological dysfunction. We present the case of a 36-year-old female with bilateral orbital lesions whose initial presentation was that of progressive proptosis and visual loss. She underwent bilateral pterional craniotomies with gross total resection of her tumours. Review of the literature reveals several cases of unilateral orbital fibrous dysplasia. This appears to be the first reported case of distinct, bilateral orbital fibrous dysplasia.

OBJECTIVE: Posterior cervical arthrodesis and stabilization with lateral mass plates is a biomechanically sound construct in multiple planes of motion. It is reproducible and especially useful when the posterior elements are missing or fractured. Unfortunately, it is difficult to use in patients with severe degenerative spondylosis because the plate is malleable only in the sagittal plane and the screw positions are dictated by the plate's entry holes. METHODS: A novel system of lateral mass screws that can be positioned before placement of a lateral construct was used in nine patients. Their outcomes as well as the technical applications of this system were reviewed. RESULTS: A total of 52 screws were placed in nine patients who underwent posterior cervical arthrodesis with the Cervifix system (Synthes USA, Paoli, PA). Diagnoses included trauma in four patients, degenerative spondylosis in three, and tumor in two. Rods were molded individually according to the patient's anatomy. Compression, distraction, and lateral rotation, if indicated, were performed. Follow-up averaged 36 weeks. Lateral and anteroposterior radiographs, obtained at progressive intervals, revealed excellent fixation and screw purchase without pull-out. There were no cases of spinal cord, nerve root, or vertebral artery injury. CONCLUSION: The Cervifix system accommodates variation in anatomic size and spacing of the lateral masses, potentiating precise screw placement. The rods can be molded in multiple planes, and selective application of compressive, distractive, or lateral rotatory forces is allowed. The system is very straightforward and simple to use, and we have had good success without pseudarthrosis or complications from screw placement in our series.

Object: Reconstruction of the cranial base after resection of complex lesions requires creation of both a vascularized barrier to cerebrospinal fluid (CSF) leakage and tailored filling of operative defects. The authors describe the use of radial forearm microvascular free-flap grafts to reconstruct skull base lesions, to fill small tissue defects, and to provide an excellent barrier against CSF leakage., Methods: Ten patients underwent 11 skull base procedures including placement of microvascular free-flap grafts harvested from the forearm and featuring the radial artery and its accompanying venae comitantes. Operations included six craniofacial, three lateral skull base, and two transoral procedures for various diseases. Excellent results were obtained, with no persistent CSF leaks, no flap failures, and no operative infections. One temporary CSF leak was easily repaired with flap repositioning, and at one flap donor site minor wound breakdown was observed. One patient underwent a second procedure for tumor recurrence and CSF leakage at a site distant from the original operation., Conclusions: Microvascular free tissue transfer reconstruction of skull base defects by using the radial forearm flap provides a safe, reliable, low-morbidity method for reconstructing the skull base and is ideally suited to "low-volume" defects.

Neurosurgeons perform operations every day, many of which involve the scalp. There is evidence supporting similar or decreased wound infection rates in the unshaven scalp. Patients with standard scalp incisions were assigned to either shave or shaveless preparations (n = 20). The timing of preparation and skin closure was recorded for both groups as were infectious complications. All of the patients have been followed for an average of 10 months. There were no cases of infection. The timing of scalp preparation and closure was not significantly different between the two groups (P < .05). We have previously suggested that shaving the scalp is not a critical step in the prevention of infection. We confirm that the timing of this technique is not prolonged over that of standard preparations.

With greater understanding of the pathophysiological mechanisms by which carotid artery-cavernous sinus fistulas occur, and with improved endovascular devices, more appropriate and definitive treatments are being performed. The authors define cartoid cavernous fistulas based on an accepted classification system and the signs and symptoms related to these fistulas are described. Angiographic evaluation of the risk the lesion may pose for precipitating stroke or visual loss in the patient is discussed. The literature on treatment alternatives for the different types of fistulas including transvenous, transarterial, and conservative management is reviewed.

In the treatment of acoustic neuroma, operative results have improved greatly during recent years, with high rates of functional cranial nerve preservation. Because of this, it has become more important to consider issues of patient satisfaction and quality of life (QOL) following treatment for these lesions. The authors have developed a novel questionnaire designed to measure QOL in patients with acoustic neuromas, and they administered it to 50 consecutive patients at least 6 months after acoustic neuroma surgery. Overall QOL was judged to be good but with definite minor difficulties, including some problems with hearing, facial nerve function, headache, tinnitus, dizziness, activity level, enjoyment of life, and emotional well-being. No significant differences were found between age groups and different operative approaches, and only minor differences were found in relation to tumor size. Patients with intracanalicular tumors fared no better than those with cerebellopontine angle tumors. Analysis of the data suggests an overall good outcome from acoustic neuroma surgery; however, when discussing the possible effects on postoperative QOL, even the potential minor problems should not be minimized, especially in patients undergoing operation for small or intracanalicular tumors.

We present the case of a child with a symptomatic diencephalic astrocytoma which involuted after needle biopsy without any adjuvant therapy. A tendency for certain childhood astrocytomas to regress after partial resection has been previously suggested. However, some authors have doubted whether or not such regression actually occurs. Our case radiographically documents the spontaneous involution of a low-grade astrocytoma.

Meningioangiomatosis occurs sporadically and in patients with neurofibromatosis. The literature, however, is unclear concerning the type of neurofibromatosis associated with meningioangiomatosis. Because determining which form of neurofibromatosis predisposes to meningioangiomatosis would clarify the genetic alterations of this lesion, we reviewed all reported cases of meningioangiomatosis associated with neurofibromatosis in light of current diagnostic criteria for neurofibromatosis 1 (NF1) and neurofibromatosis 2 (NF2). All well-documented cases of meningioangiomatosis occurred in the setting of NF2, implying that germline alterations of the NF2 gene predispose to meningioangiomatosis. To determine whether sporadic (non-NF) cases of meningioangiomatosis arise from somatic alterations of the same gene, we screened the NF2 gene for mutations in 12 sporadic cases of meningioangiomatosis and in constitutional DNA from 6 of these 12 patients. No mutations were found in either the lesional or constitutional DNA, which suggests that sporadic meningioangiomatosis is not a forme fruste of NF2 and that somatic alterations of the NF2 gene do not play a major role in sporadic meningioangiomatosis. For some tumor suppressor genes, germline mutations may predispose to specific tumors, while similar sporadic lesions only rarely suffer somatic mutations in these genes. The present findings suggest a similar dichotomy for the NF2 gene in meningioangiomatosis.

Hydrocephalic patients undergo repetitive surgical procedures, most of which involve the scalp. 141 shaveless operations involving scalp incisions for cerebrospinal fluid (CSF) shunts as well as 218 historical controls were reviewed after the senior author ceased shaving the scalp. The study population has been followed for a mean of 13.4 months and the control population for a mean of 38.6 months. The actuarial rate of infection at 1 year was 3.3% in the study population and 6.9% in the control population. Anesthesia times were not significantly different. Shaving of the scalp is not a critical step in the prevention of CSF shunt infection.

The authors present the case of an 11-year-old boy with symptomatic tethering of the hindbrain related to a Chiari Type III malformation repaired at birth. Surgical release of the cord resulted in functional improvement.