Michael A. Horgan

Acoustic neuroma surgery outcomes.

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.

Shaving of the Scalp May Increase the Rate of Infection in CSF Shunt Surgery

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.

Safety of microvascular decompression for trigeminal neuralgia in the elderly: Clinical article

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.

Helmet use and reduction in skull fractures in skiers and snowboarders admitted to the hospital

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.

Spontaneous Involution of a Diencephalic Astrocytoma

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.

Hearing preservation with the transcrusal approach to the petroclival region.

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.

Posterior cervical arthrodesis and stabilization: an early report using a novel lateral mass screw and rod technique

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 plates 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 patients 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.

Trends in neurosurgical complication rates at teaching vs nonteaching hospitals following duty-hour restrictions.

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.

Glioneuronal tumor with unique imaging and histologic features

Mixed glioneuronal neoplasms are relatively rare. In the past several years there have been several reports of tumors of this origin that are not accommodated in the recent WHO classification (2000). We describe a case of an anaplastic glioneuronal tumor with neuropil-like and rosetted islands in a 42 year old male who presented with new onset seizures. Evaluation by MRI revealed a large, cystic frontal lesion with a small area of enhancement (Figure 1a). The patient subsequently underwent a gross total resection of the tumor. On histopathology, the tumor was noted to have a varied appearance which partially resembled an infiltrating glioma with both astrocytic and oligodenroglioma-like regions with multi-nucleated giant cells (Figure 1b), and featured regions with smaller cells with rounded nuclei in clusters and rosettes around neuropillike regions (Figures 1c and 1d). Five recent reports of over 20 cases of distinctive glioneuronal tumors with neuropil-like islands have shown variable imaging characteristics as well as differing clinical progression after surgical resection. The majority of lesions with evidence of enhancement on imaging studies have amore benign course, while patients harboring nonenhancing lesions have a more unfavorable prognosis [1– 5]. The pathophysiology and biologic behavior of this tumor type remains to be elucidated. It is key for future reports to discriminate this from other more benign glioneuronal tumors as the distinction may affect the subsequent treatment.

External carotid artery to middle cerebral artery bypass with the saphenous vein graft.

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.