Association Between Surgeon Scorecard Use and Operating Room Costs.

Importance: Despite the significant contribution of surgical spending to health care costs, most surgeons are unaware of their operating room costs. Objective: To examine the association between providing surgeons with individualized cost feedback and surgical supply costs in the operating room. Design, Setting, and Participants: The OR Surgical Cost Reduction (OR SCORE) project was a single-health system, multihospital, multidepartmental prospective controlled study in an urban academic setting. Intervention participants were attending surgeons in orthopedic surgery, otolaryngology-head and neck surgery, and neurological surgery (n = 63). Control participants were attending surgeons in cardiothoracic surgery, general surgery, vascular surgery, pediatric surgery, obstetrics/gynecology, ophthalmology, and urology (n = 186). Interventions: From January 1 to December 31, 2015, each surgeon in the intervention group received standardized monthly scorecards showing the median surgical supply direct cost for each procedure type performed in the prior month compared with the surgeon's baseline (July 1, 2012, to November 30, 2014) and compared with all surgeons at the institution performing the same procedure at baseline. All surgical departments were eligible for a financial incentive if they met a 5% cost reduction goal. Main Outcomes and Measures: The primary outcome was each group's median surgical supply cost per case. Secondary outcome measures included total departmental surgical supply costs, case mix index-adjusted median surgical supply costs, patient outcomes (30-day readmission, 30-day mortality, and discharge status), and surgeon responses to a postintervention study-specific health care value survey. Results: The median surgical supply direct costs per case decreased 6.54% in the intervention group, from $1398 (interquartile range [IQR], $316-$5181) (10 637 cases) in 2014 to $1307 (IQR, $319-$5037) (11 820 cases) in 2015. In contrast, the median surgical supply direct cost increased 7.42% in the control group, from $712 (IQR, $202-$1602) (16 441 cases) in 2014 to $765 (IQR, $233-$1719) (17 227 cases) in 2015. This decrease represents a total savings of $836 147 in the intervention group during the 1-year study. After controlling for surgeon, department, patient demographics, and clinical indicators in a mixed-effects model, there was a 9.95% (95% CI, 3.55%-15.93%; P = .003) surgical supply cost decrease in the intervention group over 1 year. Patient outcomes were equivalent or improved after the intervention, and surgeons who received scorecards reported higher levels of cost awareness on the health care value survey compared with controls. Conclusions and Relevance: Cost feedback to surgeons, combined with a small departmental financial incentive, was associated with significantly reduced surgical supply costs, without negatively affecting patient outcomes.

Clinical utility and cost analysis of routine postoperative head CT in elective aneurysm clippings.

OBJECTIVE Postoperative head CT scanning is performed routinely at the authors' institution on all neurosurgical patients after elective aneurysm clippings. The goal of this study was to determine how often these scans influence medical management and to quantify the associated imaging costs. METHODS The authors reviewed the medical records and accounting database of 304 patients who underwent elective (i.e., nonruptured) aneurysm clipping performed by 1 surgeon (M.T.L.) from 2010 to 2014 at the University of California, San Francisco. Specifically, the total number of postoperative head CT scans, radiographic findings, and the effect of these studies on patient management were determined. The authors obtained the total hospital costs for these patients, including the cost of imaging studies, from the hospital accounting database. RESULTS Overall, postoperative CT findings influenced clinical management in 3.6% of cases; specifically, they led to permissive hypertension in 4 patients for possible ischemia, administration of mannitol for edema and high-flow oxygen for pneumocephalus in 2 patients each, seizure prophylaxis in 1 patient, Plavix readjustment in 1 patient, and return to the operating room for an asymptomatic epidural hematoma evacuation in 1 patient. When patients were stratified on the basis of postoperative neurological examination, findings on CT scans altered management in 1.1%, 4.8%, and 9.0% of patients with no new neurological deficits, a nonfocal examination, and focal deficits, respectively. The mean total hospital cost for treating patients who undergo elective aneurysm clipping was $72,227 (± $53,966) (all values are US dollars), and the cost of obtaining a noncontrast head CT scan was $292. Neurologically intact patients required 99 head CT scans, at a cost of $28,908, to obtain 1 head CT scan that influenced medical management. In contrast, patients with a focal neurological deficit required only 11 head CT scans, at a cost of $3212, to obtain 1 head CT scan that changed clinical management. CONCLUSIONS Although there are no clear guidelines, the large number and high cost of CT scans needed to treat neurologically intact elective aneurysm patients suggest that careful neurological monitoring may be more clinically useful and a better use of hospital resources than routine postoperative CT.

Extent of resection and the long-term durability of vestibular schwannoma surgery.

OBJECT: With limited studies available, the correlation between the extent of resection and tumor recurrence in vestibular schwannomas (VSs) has not been definitively established. In this prospective study, the authors evaluated 772 patients who underwent microsurgical resection of VSs to analyze the association between total tumor resection and the tumor recurrence rate. METHODS: The authors selected all cases from a prospectively collected database of patients who underwent microsurgical resection as their initial treatment for a histopathologically confirmed VS. Recurrence-free survival was analyzed using Kaplan-Meier analysis. The authors studied the impact of possible confounders such as patient age and tumor size using stepwise Cox regression to calculate the proportional hazard ratio of recurrence while controlling for other cofounding variables. RESULTS: The authors analyzed data obtained in 571, 89, and 112 patients in whom gross-total, near-total, and subtotal resections, respectively, were performed. A gross-total resection was achieved in 74% of the patients, and the overall recurrence rate in these patients 8.8%. There was no significant relation between the extent of resection and the rate of tumor recurrence (p = 0.58). As expected, the extent of resection was highly correlated with patient age, tumor size, and surgical approach (p < 0.0001). Using Cox regression, the authors found that the approach used did not significantly affect tumor control when the extent of resection was controlled for. CONCLUSIONS: While complete tumor removal is ideal, the results presented here suggest that there is no significant relationship between the extent of resection and tumor recurrence.

Implications of cystic features in vestibular schwannomas of patients undergoing microsurgical resection.

BACKGROUND: Cystic vestibular schwannomas (VSs) are described as being more aggressive than solid tumors. OBJECTIVE: We examined 468 VS patients to evaluate whether the presence of cystic components in VSs may be an important feature for predicting postoperative outcome. METHODS: We selected all VS patients from a prospectively collected database (1984-2009) who underwent microsurgical resection for VS. Hearing data were analyzed using American Association of Otolaryngology-Head and Neck Surgery. Facial nerve dysfunction was analyzed using the House-Brackmann scale. We used univariate comparisons to determine the clinical impact of cystic changes on preoperative and postsurgical hearing and facial nerve preservation. RESULTS: We identified 58 patients (11%) with cystic changes and 410 patients with solid VSs. In this analysis, cystic VS patients tended to have larger tumors (78% of patients with >2.0 cm extrameatal extension) compared with the solid VS group, which consisted of many smaller and medium-sized tumors (P < .0001). Univariate analyses found that tumors with cystic changes did not lead to worse rates of preoperative hearing loss (χ(2), P = not significant) compared with solid VSs. Cystic changes conferred worse postoperative hearing in patients with medium-sized tumors (P = .035). Cystic changes also did not significantly affect facial nerve outcomes (χ(2), P = not significant). CONCLUSION: Cystic tumors tend to be larger than noncystic tumors and affect outcomes by reducing the rate at which hearing preservation is attempted and by worsening hearing outcome in medium-sized tumors. Further, peripheral cysts cause lower rates of hearing preservation compared with centrally located cysts.

Factors associated with preservation of facial nerve function after surgical resection of vestibular schwannoma.

Avoidance of facial nerve palsy is one of the major goals of vestibular schwannoma (VS) microsurgery. In this study, we examined the significance of previously implicated prognostic factors (age, tumor size, the extent of resection and the surgical approach) on post-operative facial nerve function. We selected all VS patients from prospectively collected database (1984-2009) who underwent microsurgical resection as their initial treatment for histopathologically confirmed VS. The effect of variables such as surgical approach, tumor size, patient age and extent of resection on rates facial nerve dysfunction after surgery, were analyzed using multivariate logistic regression. Patients with preoperative facial nerve dysfunction (House-Brackman [HB] score 3 or higher) were excluded, and HB grade of 1 or 2 at the last follow-up visit was defined as "facial nerve preservation." A total of 624 VS patients were included in this study. Multivariate logistic regression analysis found that only pre-operative tumor size significantly predicted poorer facial nerve outcome for patients followed-up for ≥6 and ≥12 months (OR 1.27, 95% CI 1.09-1.49, p < 0.01; OR 1.35, 95% CI 1.10-1.67, P < 0.01, respectively). We found no significant relationship between facial nerve function and age, extent of resection, surgical approach, or tumor size (when extent of resection and surgical approach were included in the regression analysis). Because facial nerve palsy is a debilitating and psychologically devastating condition for the patient, we suggest altering surgical aggressiveness in patients with unfavorable tumor anatomy, particularly in cases with large tumors where overaggressive resection might subject the patient to unwarranted risk. Residual disease can be followed and controlled with radiosurgery if interval growth is noted.

Intratumoral hemorrhage and fibrosis in vestibular schwannoma: a possible mechanism for hearing loss.

OBJECT: Vestibular schwannomas (VSs) are benign lesions with an unpredictable natural history. Perhaps the greatest barrier to predicting which patients need treatment is our poor understanding of how these tumors cause hearing loss in the first place. In this case-control study, the authors investigated the relationship between preoperative hearing loss and histological changes such as intratumoral microhemorrhage and extensive fibrosis. METHODS: From a prospectively collected database, the authors selected all patients with VS who had undergone microsurgical resection as their initial treatment for histopathologically confirmed VS. Histological specimens obtained in 274 of these patients were systematically reviewed by a blinded neuropathologist who graded the extent of microhemorrhage and fibrosis in these tumors. The effect of these variables on preoperative hearing loss was studied using binary logistic regression. RESULTS: On univariate analysis, patients with extensive intratumoral microhemorrhage or fibrosis (p < 0.0001), patients with larger tumors (p < 0.05), and patients 65 years of age or older (p < 0.05) were significantly more likely to have unserviceable hearing at the time of surgery. On multivariate analysis, only patients with extensive intratumoral microhemorrhage or fibrosis had an increased risk of having unserviceable hearing at the time of surgery (OR 3.72, 95% CI 1.3-10; p = 0.01). Older age and tumor size greater than 3 cm were not statistically significant risk factors for hearing loss, controlling for the effect of microhemorrhage and fibrosis. CONCLUSIONS: In this study, the authors have demonstrated a correlation between the extent of nonneoplastic histological changes, such as microhemorrhage and fibrosis, and hearing loss. This alternate hypothesis has the potential to explain many of the exceptions to previously described mechanisms of hearing loss in patients with VS. The advent of high-resolution MR imaging technology to identify microhemorrhages may provide a method to screen for patients with VS at risk for hearing loss.

A prospective study of hearing preservation in untreated vestibular schwannomas.

OBJECT: The authors previously published a systematic review of the English language literature regarding the natural history of untreated vestibular schwannomas (VSs). This analysis found that the best predictor of future hearing loss was tumor growth > 2.5 mm/year on serial imaging, a factor that doubled the rate of hearing loss. In this paper the authors present an analysis of prospectively collected outcomes in patients with untreated VS from their institution that confirms their previous findings. METHODS: Clinical, radiographic, and audiometric data for all patients evaluated for VS at the authors' institution over a 22-year period were prospectively collected in a database. All patients in this database who had serviceable hearing (American Academy of Otolaryngology-Head and Neck Surgery Grade A or B) on initial presentation were selected, and underwent serial observation. Magnetic resonance imaging and audiometric data were analyzed, and the time from presentation until hearing loss was analyzed using Kaplan-Meier analysis. RESULTS: Fifty-nine patients with VS who initially presented with serviceable hearing were treated conservatively over this period. Consistent with the authors' previous findings, patients with a tumor growth rate > 2.5 mm/year at any point during follow-up lost their hearing at a much faster rate than those who had slower growing tumors. The median time to hearing loss was 7.0 years in those patients with tumor growth rate > 2.5 mm/year compared to 14.8 years in the other patients (p < 0.0001). The estimated median time to hearing loss in the 3 initial tumor size groups was 11.6 years in the intracanalicular group, 10.3 years in the group with 0.1-1 cm extension into the CPA cistern, and 9.3 years in the group with > 1 cm extension into the CPA cistern (p value nonsignificant). Initial tumor size, age at diagnosis, and neurofibromatosis Type 2 status did not affect the time to loss of serviceable hearing. Interestingly, many patients who were followed up for more than a decade eventually lost their hearing, regardless of whether the tumor displayed any documented interval growth. CONCLUSION: The authors confirmed the findings of their systematic review of the literature using a prospectively followed group of patients with untreated VS. Collectively, these data suggest that the expectation for more rapid hearing loss should be communicated to patients, and the decision for surgical or other intervention should be made in the context of the known risk of continued observation of fast growing tumors.

A critical evaluation of vestibular schwannoma surgery for patients younger than 40 years of age.

BACKGROUND: There are few published prospective data sets specifically focusing on patients younger than 40 years old undergoing microsurgery for vestibular schwannoma. OBJECTIVE: We describe functional outcomes and long-term tumor control after surgery in patients younger than 40 years old enrolled in a prospectively collected database over a 25-year period. METHODS: We selected all vestibular schwannoma patients from a prospectively collected database who were younger than 40 years old at the time of surgical resection for a vestibular schwannoma. Rates of tumor control and hearing preservation were analyzed using Kaplan-Meier analysis, and risk factors for facial nerve palsy, hearing loss, and trigeminal neuropathy were analyzed using multivariate logistic regression. RESULTS: A total of 204 patients younger than 40 years of age met our inclusion criteria and were included in the analysis. Our data indicate that surgical resection leads to durable long-term freedom from tumor recurrence or progression in 89% of young patients at 15 years of follow-up. Consistent with other published series, hearing was preserved in 68% of patients with smaller tumors (<3 cm). Facial nerve function was preserved in 76% of patients with smaller tumors and 52% of patients with larger tumors (P<.001). On multivariate logistic regression, tumor size was a significant predictor of hearing loss, whereas gross total resection was nearly a significant predictor of hearing loss controlling for other variables (P=.06). CONCLUSION: We present the largest prospectively studied cohort of young patients undergoing microsurgical resection of vestibular schwannoma. These data suggest that surgical resection provides excellent long-term tumor control in these patients.

The value of intraoperative facial nerve electromyography in predicting facial nerve function after vestibular schwannoma surgery.

The prognostic significance of intraoperative facial nerve electromyography (EMG) changes is not well-established in vestibular schwannoma (VS) surgery. We studied facial nerve EMG with a threshold >0.05mA and performed subgroup analyses based on tumor size, resection approach, and extent of resection, for prediction of long-term facial nerve outcome. A total of 477 surgically treated VS patients were included. Elevated stimulation threshold exceeding >0.05mA is a highly specific (90%), but very insensitive (29%) finding in this cohort. The positive predictive value and negative predictive values (NPV) of facial nerve EMG for detection of permanent facial palsy are 68% and 63%, respectively. The NPV decreased with increasing tumor size (72% versus [vs.] 64% vs. 53%) due to the increasing prevalence of post-operative facial nerve palsy in these patients. In conclusion, while facial nerve EMG is a critical adjunct for locating the facial nerve intraoperatively, its predictive value for facial nerve function remains to be determined.

A comprehensive analysis of hearing preservation after radiosurgery for vestibular schwannoma.

OBJECT: Gamma Knife surgery (GKS) has evolved into a practical alternative to open microsurgical resection in the treatment of patients with vestibular schwannoma (VS). Hearing preservation rates in GKS series suggest very favorable outcomes without the possible acute morbidity associated with open microsurgery. To mitigate institutional and practitioner bias, the authors performed an analytical review of the published literature on the GKS treatment of vestibular schwannoma patients. Their aim was to objectively characterize the prognostic factors that contribute to hearing preservation after GKS, as well as methodically summarize the reported literature describing hearing preservation after GKS for VS. METHODS: A comprehensive search of the English-language literature revealed a total of 254 published studies reporting assessable and quantifiable outcome data obtained in patients who underwent radiosurgery for VSs. Inclusion criteria for articles were 4-fold: 1) hearing preservation rates reported specifically for VS; 2) hearing status reported using the American Association of Otolaryngology-Head and Neck Surgery (AAO-HNS) or Gardner-Robertson classification; 3) documentation of initial tumor size; and 4) GKS was the only radiosurgical modality in the treatment. In the analysis only patients with AAO-HNS Class A or B or Gardner-Robertson Grade I or II status at the last follow-up visit were defined as having preserved hearing. Hearing preservation and outcome data were then aggregated and analyzed based on the radiation dose, tumor volume, and patient age. RESULTS: The 45 articles that met the authors' inclusion criteria represented 4234 patients in whom an overall hearing preservation rate was 51%, irrespective of radiation dose, patient age, or tumor volume. Practitioners who delivered an average < or = 13-Gy dose of radiation reported a higher hearing preservation rate (60.5% at < or = 13 Gy vs 50.4% at > 13 Gy; p = 0.0005). Patients with smaller tumors (average tumor volume < or = 1.5 cm(3)) had a hearing preservation rate (62%) comparable with patients harboring larger tumors (61%) (p = 0.8968). Age was not a significant prognostic factor for hearing preservation rates as in older patients there was a trend toward improved hearing preservation rates (56% at < 65 years vs 71% at > or = 65 years of age; p < 0.1134). The average overall follow-up in the studies reviewed was 44.4 +/- 32 months (median 35 months). CONCLUSIONS: These data provide a methodical overview of the literature regarding hearing preservation with GKS for VS and a less biased assessment of outcomes than single-institution studies. This objective analysis provides insight into advising patients of hearing preservation rates for GKS treatment of VSs that have been reported, as aggregated in the published literature. Analysis of the data suggests that an overall hearing preservation rate of approximately 51% can be expected approaching 3-4 years after radiosurgical treatment, and the analysis reveals that patients treated with < or = 13 Gy were more likely to have preserved hearing than patients receiving larger doses of radiation. Furthermore, larger tumors and older patients do not appear to be at any increased risk for hearing loss after GKS for VS than younger patients or patients with smaller tumors.

The natural history of untreated sporadic vestibular schwannomas: a comprehensive review of hearing outcomes.

OBJECT: Observation is an important consideration when discussing management options for patients with vestibular schwannoma (VS). Most data regarding clinical outcomes after conservative management come from modestsized series performed at individual centers. The authors performed an analysis of the published literature on the natural history of VSs with respect to hearing outcome. Their objective was to provide a comprehensive and unbiased description of outcomes in patients whose disease was managed conservatively. METHODS: The authors identified a total of 34 published studies containing hearing outcome data in patients with VSs < 25 mm in largest diameter who underwent observation management. The effects of initial tumor size and tumor growth rate on hearing function at latest follow-up were analyzed. Data from individual and aggregated cases were extracted from each study. Patients with poorer hearing (American Association of Otolaryngology-Head and Neck Surgery Classes C or D, or Gardner-Robertson Classes III, IV, or V) at the time of presentation were excluded. RESULTS: A total of 982 patients met the inclusion criteria for this analysis, with a mean initial tumor size of 11.3 +/- 0.68 mm. The mean growth rate was 2.9 +/- 1.2 mm/year. The length of follow-up for these studies ranged from 26 to 52 months. Patients with preserved hearing at latest follow-up had a statistically larger initial tumor size than those whose hearing declined during the observation period (11.5 +/- 2.3 mm vs 9.3 +/- 2.7 mm, p < 0.0001), but the 2-mm difference of means was at the limit of imaging resolution and observer reliability. In contrast, patients with lower rates of tumor growth ( 2.5 mm/year is a better predictor of hearing loss than the initial tumor size for patients undergoing observation management of VSs < 25 mm in largest diameter.

Facial nerve preservation after vestibular schwannoma Gamma Knife radiosurgery.

OBJECTIVE: Facial nerve preservation is a critical measure of clinical outcome after vestibular schwannoma treatment. Gamma Knife radiosurgery has evolved into a practical treatment modality for vestibular schwannoma patients, with several reported series from a variety of centers. In this study, we report the results of an objective analysis of reported facial nerve outcomes after the treatment of vestibular schwannomas with Gamma Knife radiosurgery. MATERIALS AND METHODS: A Boolean Pub Med search of the English language literature revealed a total of 23 published studies reporting assessable and quantifiable outcome data regarding facial nerve function in 2,204 patients who were treated with Gamma Knife radiosurgery for vestibular schwannoma. Inclusion criteria for articles were: (1) Facial nerve preservation rates were reported specifically for vestibular schwannoma, (2) Facial nerve functional outcome was reported using the House-Brackmann classification (HBC) for facial nerve function, (3) Tumor size was documented, and (4) Gamma Knife radiosurgery was the only radiosurgical modality used in the report. The data were then aggregated and analyzed based on radiation doses delivered, tumor volume, and patient age. RESULTS: An overall facial nerve preservation rate of 96.2% was found after Gamma Knife radiosurgery for vestibular schwannoma in our analysis. Patients receiving less than or equal to 13 Gy of radiation at the marginal dose had a better facial nerve preservation rate than those who received higher doses (13 Gy = 94.7%, P < 0.0001). Patients with a tumor volume less than or equal to 1.5 cm(3) also had a greater facial nerve preservation rate than patients with tumors greater than 1.5 cm(3) (1.5 cm(3) 95.5%, P < 0.0001). Superior facial nerve preservation was also noted in patients younger than or equal to 60 years of age (96.8 vs. 89.4%, P < 0.0001). The average reported follow up duration in this systematic review was 54.1 +/- 31.3 months. CONCLUSION: Our analysis of case series data aggregated from multiple centers suggests that a facial nerve preservation rate of 96.2% can be expected after Gamma knife radiosurgery for vestibular schwannoma. Younger patients with smaller tumors less than 1.5 cm(3) and treated with lower doses of radiation less than 13 Gy will likely have better facial nerve preservation rates after Gamma Knife radiosurgery for vestibular schwannoma.

Hearing preservation after stereotactic radiosurgery for vestibular schwannoma: a systematic review.

Radiosurgery has evolved into an effective alternative to microsurgical resection in the treatment of patients with vestibular schwannoma. We performed a systematic analysis of the literature in English on the radiosurgical treatment of vestibular schwannoma patients. A total of 254 published studies reported assessable and quantifiable outcome data of patients undergoing radiosurgery for vestibular schwannomas. American Association of Otolaryngology-Head and Neck Surgery (AAO-HNS) class A or B and Gardner-Robertson (GR) classification I or II were defined as having preserved hearing. A total of 5825 patients (74 articles) met our inclusion criteria. Practitioners who delivered an average dose of 12.5 Gy as the marginal dose reported having a higher hearing preservation rate (12.5 Gy=59% vs. >12.5 Gy=53%, p=0.0285). Age of the patient was not a significant prognostic factor for hearing preservation rates (<65 years=58% vs. >65 years=62%; p=0.4317). The average overall follow-up was 41.2 months. Our data suggest that an overall hearing preservation rate of about 57% can be expected after radiosurgical treatment, and patients treated with 12.5 Gy were more likely to have preserved hearing.

Selection of surgical approach to acoustic neuroma. 1992.

A variety of surgical approaches are available in the management of acoustic neuroma. Each procedure has certain advantages and disadvantages in terms of surgical exposure, the capability of preserving cranial nerve function, and postoperative morbidity. This article advocates tailoring the operative approach to each acoustic neuroma according to its size, location, and clinical manifestations.

Optimal placement of recording electrodes for quantifying facial nerve compound muscle action potential.

OBJECTIVE: To analyze optimal placement of recording-needle electrodes surrounding the eye and lip for facial nerve monitoring by identifying the maximum compound muscle action potential (CMAP) recorded by electrode pairs of different spatial configurations. STUDY DESIGN: Prospective clinical trial. SETTING: Ambulatory surgery at a tertiary care center. PATIENTS: Thirty adults undergoing chronic ear surgery such as tympanoplasty, mastoidectomy, ossicular chain reconstruction, stapedectomy, and cochlear implantation. INTERVENTION: Facial nerve monitoring. MAIN OUTCOME MEASURE: Suprathreshold (threshold + 0.2 V) CMAP responses are recorded from referential paired needle electrodes placed into orbicularis oculi (1.5-cm spacing; n = 15) and orbicularis oris (1.0-cm spacing; n = 15) muscles. Optimal recording electrode placement is inferred by identifying the maximum evoked CMAP amplitude. RESULTS: For the eye, placement of electrodes by the orbital rim and into the upper eyelid is significantly better (Friedman test; p < 0.01) than the other 2 configurations. For the lip, placement of electrodes into the oral commissure and either the upper or lower lip is satisfactory because there is no statistically significant difference among the configurations (Friedman test; p > 0.2). CONCLUSION: Recording electrode placement configurations that capture the largest CMAP responses are recommended as standard operating procedure for intraoperative facial nerve monitoring.

Complications of lumboperitoneal shunts.

OBJECTIVE: Placement of a lumboperitoneal (LP) shunt is a method for treating communicating hydrocephalus. These shunts can be placed with or without valves. We sought to review the complications associated with the use of LP shunts with the increasing use of horizontal-vertical (HV) valve systems. PATIENTS AND METHODS: A retrospective chart review of all patients who received LP shunts at University of California, San Francisco from 1998 to 2005 was performed. RESULTS: Of the 74 patients identified in this study, 67 underwent LP shunt placement for the first time, and seven patients had revisions of LP shunts that were originally placed at another hospital. There were a total of 44 revisions for the entire group: 27 patients had one revision, 10 patients had two or three revisions, and one patient had five revisions. Obstruction or migration of the peritoneal catheter was the most common reason for revision. The HV valve was responsible for shunt malfunction in nine patients and was the second-most common site of system problems. Overdrainage symptoms were observed in 11 patients, most of whom had LP shunts without any valve. No patients with an HV valve system developed an acquired Chiari malformation. There were three cases of infection, two of which required removal of the LP shunt. CONCLUSION: Overall, the placement of LP shunts for the treatment of communicating hydrocephalus seems to be a safe procedure. Serious complications such as subdural hematoma were not observed. The HV valve was associated with minor complications, but it was effective in reducing the incidence of overdrainage.

Intraoperative electrophysiologic identification of the nervus intermedius.

OBJECTIVE: Although enormous attention has been directed to the localization and preservation of the facial nerve in acoustic neuroma surgery, the nervus intermedius has largely been ignored. In this article, we describe a method for intraoperative electrophysiologic identification of the nervus intermedius. STUDY DESIGN: Retrospective case review. SETTING: University hospital (tertiary care center). PATIENTS: Thirty-three patients who underwent intraoperative facial nerve monitoring for various cerebellopontine angle procedures. Recording electrodes were placed in the orbicularis oculi and orbicularis oris muscles. A constant-voltage stimulator was used to stimulate both the facial nerve and the nervus intermedius. INTERVENTIONS: None. MAIN OUTCOME MEASURE: Electrophysiologic response after stimulation of the nervus intermedius. RESULTS: Stimulation of the nervus intermedius produced long-latency, low-amplitude response recorded only on the orbicularis oris channel. The response had a mean threshold 0.4 V, a mean latency of 11.1 ms, and a mean amplitude of 11.1 microV, all significantly different from responses to stimulation the facial nerve. CONCLUSION: Knowledge of electrophysiologic features of nervus intermedius stimulation can help protect the facial nerve during cerebellopontine angle surgery. The surgeon must recognize that stimulation of the nervus intermedius can cause electromyographic activity in the facial nerve monitoring channels, but the main trunk of the facial nerve may lie in entirely different location in the cerebellopontine angle.

The fate of the tumor remnant after less-than-complete acoustic neuroma resection.

OBJECTIVES: We sought to determine the recurrence rate after near-total and subtotal resection of acoustic neuroma. STUDY DESIGN, SETTING, AND PATIENTS: We conducted a retrospective chart review of a total of 79 patients: 50 with near-total resections (remnant < or =25 mm(2) and < or =2 mm thick) and 29 with subtotal resections (any larger remnant). Surgical approach included 5 middle fossa, 17 retrosigmoid, and 57 translabyrinthine. MAIN OUTCOME MEASURES: Recurrence was defined as documented tumor growth by serial imaging or the recommendation for further treatment after a single scan. No recurrence was defined as no visible tumor on imaging for a minimum follow-up time of 3 years or tumor remnants that remained unchanged on serial scans (mean, 5-year follow-up). RESULTS: Fifty-two patients were included in the study group. Recurrences were seen in 1 (3%) of 33 patients who had a near-total resection compared with 6 (32%) of 19 patients who had a subtotal resection. After adjustment for follow-up time and large tumor size, the odds ratio for recurrence was 12 times larger for subtotal than for near-total resections (P = 0.033). All recurrences were seen following the translabyrinthine approach in the mid-cerebellopontine angle. None were encountered in the internal auditory canal. The mean time interval from surgery to the detection of a recurrence was 3 years (range, 1 to 5 years). CONCLUSIONS: The recurrence rate when performing a near-total resection is low but is substantially higher with a subtotal resection. Recurrences can be detected within the first 5 postoperative years. We recommend near-total resection in any patient if needed to preserve neural integrity. Subtotal resection is best avoided whenever possible; however, adjunctive treatment with stereotactic radiotherapy may be considered.

Resolution of intracranial hypertension after elevation of depressed cranial fracture over the superior sagittal sinus: case report.

OBJECTIVE AND IMPORTANCE: It is common neurosurgical wisdom that depressed cranial fractures (DCFs) over the superior sagittal sinus (SSS) should not be elevated because of the risk of fatal venous hemorrhage. CLINICAL PRESENTATION: A 34-year-old man presented with severe headache and diplopia after a motor vehicle accident. Clinical examination demonstrated severe papilledema and bilateral abducens palsy. Imaging findings demonstrated a DCF over the posterior third of the SSS and absent flow distal to the fracture with dilated cortical venous drainage. INTERVENTION: Conservative treatment with acetazolamide only partially alleviated the patient's headache and diplopia. Definitive surgical treatment via elevation of the DCF was discussed and decided upon. Twelve days after injury, the patient underwent midline parieto-occipital craniotomy with successful elevation of the DCF off the posterior third of the SSS. Postoperative magnetic resonance venograms revealed restoration of patency in the SSS with reduced tortuosity of cortical veins. The patient's headache resolved, and his papilledema and diplopia resolved gradually. CONCLUSION: Elevation of DCF over the SSS can be attempted in cases in which favorable bone anatomy and the patient's clinical condition warrant. This may result in rapid and dramatic resolution of signs and symptoms of secondary intracranial hypertension.