Is There a Plateau to the Learning Curve for Acoustic Neuroma Resection?-Experience and Outcomes from a Single Interdisciplinary Team Over Thirty Years.

Objective The evolution of acoustic neuroma (AN) care continues to shift focus on balancing optimized tumor resection and control with preservation of neurological function. Prior learning curve analyses of AN resection have demonstrated a plateau between 20 and 100 surgeries. In this study of 860 consecutive AN surgeries, we investigate the presence of an extended learning curve tail for AN resection. Methods A retrospective cohort study of AN resections by a single interdisciplinary team between 1988 and 2018 was performed. Proportional odds models and restricted cubic splines were used to determine the association between the timing of surgery and odds of improved postoperative outcomes. Results The likelihood of improved postoperative House-Brackmann (HB) scores increased in the first 400 procedures, with HB 1 at 36% in 1988 compared with 79% in 2004. While the probability of a better HB score increased over time, there was a temporary decrease in slope of the cubic spline between 2005 and 2009. The last 400 cases continued to see improvement in optimal HB outcomes: adjusted odds of HB 1 score were twofold higher in both 2005 to 2009 (adjusted odds ratio [aOR]: 2.11, 95% confidence interval [CI]: 1.38-3.22, p < 0.001) and 2010 to 2018 (aOR: 2.18, 95% CI: 1.49-3.19, p < 0.001). Conclusion In contrast to prior studies, our study demonstrates the steepest growth for learning, as measured by rates of preservation of facial function outcomes (HB 1), occurs in the first 400 AN resections. Additionally, improvements in patient outcomes continued even 30 years into practice, underlining the importance of lifelong learning.

Occipital Neuralgia following Acoustic Neuroma Resection.

Background While postoperative outcomes of acoustic neuroma (AN) resection commonly consider hearing preservation and facial function, headache is a critical quality of life factor. Postoperative headache is described in the literature; however, there is limited discussion specific to occipital neuralgia (ON) following AN resection. Objective The aim of this study is to investigate the effectiveness of conservative management and surgery. Methods We conducted a retrospective review of 872 AN patients who underwent resection at our institution between 1988 and 2017 and identified 15 patients (1.9%) that met International Classification of Headache Disorders criteria for ON. Results Of the 15 ON patients, surgical approaches included 13 (87%) retrosigmoid (RS), one (7%) translabyrinthine (TL), and one (7%) combined RS + TL. Mean clinical follow-up was 119 months (11-263). Six (40%) patients obtained pain relief through conservative management, while the remaining nine (60%) underwent surgery or ablative procedure. Three (38%) patients received an external neurolysis, four (50%) received a neurectomy, one (13%) had both procedures, and one (13%) received two C2 to 3 radio frequency ablations. Of the nine patients who underwent procedural ON treatment, seven (78%) patients achieved pain relief, one patient (11%) continued to have pain, and one patient (11%) was lost to follow-up. Of the six patients whose pain was controlled with conservative management and nerve blocks, five (83%) found relief by using neuropathic pain medication and one (17%) found relief on nonsteroidal anti-inflammatory drug. Conclusion Our series demonstrates success with conservative management in some, but overall a minority (40%) of patients, reserving decompression only for refractory cases.

Long-Term Outcomes of Pituitary Gland Preservation in Pituitary Macroadenoma Apoplexy: Case Series and Review of the Literature.

Introduction For patients presenting with neurological changes from pituitary tumor apoplexy, urgent surgical intervention is commonly performed for diagnosis, tumor resection, and optic apparatus decompression. Although identification and preservation of the pituitary gland during the time of surgery can be challenging, it may lead to improve endocrine outcomes. Methods A retrospective case series of all patients with macroadenomas presenting with apoplexy at Loyola University Medical Center from 2016 to 2018 was studied. Demographic, radiographic, and intraoperative characteristics were collected including age, gender, comorbidities, presenting symptoms, preoperative size of pituitary adenoma, Knosp's grade, Hardy's grade, identification and/or preservation of the gland, pre- and postoperative hormonal levels, intraoperative and/or postoperative complications, and follow-up time. Results A total of 68 patients underwent endoscopic endonasal surgery for resection of a macroadenoma. Among them, seven (10.2%) presented with apoplexy; five patients were male and two were female and presenting symptoms and signs included headache (100%), endocrinopathies (57%), visual acuity deficit (71%), visual field deficit (71%), and oculomotor palsy (57%). A gross-total resection rate was achieved in 86% of patients. Among them, 71% of patients obtained complete symptomatic neurological improvement. A statistically significant difference between gender and endocrine function was found, as no females and all males required some form of postoperative hormonal supplementation ( p = 0.047) . Conclusion Endoscopic endonasal resection of macroadenomas with sparing of the pituitary gland in the setting of apoplexy is safe and effective. Preservation of the normal gland led to no posterior pituitary dysfunction, and a statistically significant difference between gender and postoperative endocrinopathy was identified. Further studies with larger samples sizes are warranted.

Effect of Institutional Volume on Acoustic Neuroma Surgical Outcomes: State Inpatient Database 2009-2013.

BACKGROUND: Evolving technologies and health care quality metrics have altered treatment algorithms for acoustic neuromas (ANs), increasing trends toward observation and radiosurgery, with proportionate declines in use of microsurgery. A correlation between increasing surgical volumes and superior outcomes has been investigated previously in numerous surgical diseases, including AN. OBJECTIVE: To re-evaluate the volume-outcome relationship of AN resection in a changing health care system, with evolving treatment strategies. METHODS: Patients who underwent AN resection between 2009 and 2013 were retrospectively identified in the State Inpatient Database subset of the Healthcare Cost and Utilization Project. Generalized linear mixed-effect models were used to assess odds of various outcome measures (length of stay [LOS], discharge disposition, and facial nerve or severe clinical complications). Institutions were grouped into low-volume centers (1-6 cases/year) and high-volume centers (HVC; ≥31 cases/year) for analysis. RESULTS: A total of 1873 patients underwent AN resection between 2009 and 2013 with a mean age of 50.1 ± 14.1 years (±standard deviation). For each additional case treated annually, patients were 2% (odds ratio [OR], 0.98; 95% confidence interval, 0.96-0.99) less likely to experience a severe complication (P = 0.004). Each additional case also trended toward a decreased rate of facial nerve complications and nonroutine discharge. Inpatient LOS was also shorter for patients at HVCs (median, 4 vs. 5 days; P < 0.001). CONCLUSIONS: Despite a relative decline in microsurgery compared with previous eras, care at HVCs is still associated with superior short-term outcomes, such as decreased LOS, facial nerve or other severe complications, and nonroutine discharges.

Cranial Nerve Preservation Following Surgical Treatment for Epidermoid Cysts of the Posterior and Middle Fossae.

Epidermoid cysts are rare lesions, accounting for 0.2 to 1.8% of all intracranial tumors. They most commonly occur in the cerebellopontine angle where they may cause a breadth of neurologic complications due to mass effect on the nearby cranial nerves (CN), vascular structures, and the brain stem. Treatment of epidermoid cysts is surgical, with the goal of complete resection using microsurgical technique and even more importantly preservation of the involved CNs, vasculature, and brain parenchyma. Successful surgery can result in total resolution of symptoms, but, in certain situations, may not be advisable due to adherence, scarring, or inflammation making dissection of CN fascicles difficult and possibly hazardous. We conducted a retrospective review from 1998 to 2016 and compiled a series of 28 skull base epidermoid cysts operated on at our institution. Cases were evaluated for presenting symptoms, history of prior resection, and postoperative results including CN function, extent of resection, residual tumor, and need for reoperations. The average tumor size (largest diameter) was 3.9 cm with a range of 1 to 7cm. Eighteen of twenty-eight (64%) patients underwent a gross total resection and ten underwent subtotal resection. No patients, whether presenting with CN deficits or not, experienced permanent worsening of CN function following surgery. Complete resection of epidermoid cysts should remain a high priority of therapy, but, in our opinion, preservation of CN function should be a primary goal, determining the extent of resection to provide patients with the highest quality of life possible following surgery.

The Quest for Predicting Sustained Shunt Response in Normal-Pressure Hydrocephalus: An Analysis of the Callosal Angle's Utility.

BACKGROUND: Diagnosing normal-pressure hydrocephalus (NPH) and selecting patients who will experience a sustained benefit from fluid diversion surgery remains challenging. This study seeks to evaluate the association between the callosal angle (CA) and the long-term postoperative response to ventriculoperitoneal shunt surgery in a different subgroup population than previously studied to assess its generalizability. METHODS: We studied 72 patients with idiopathic NPH who underwent ventriculoperitoneal shunt surgery and had at least 18 months of follow-up between 2000 and 2016. We recorded their pre- and postoperative symptoms according to the NPH Eide scale and their comorbidities with the Kiefer index. Their CA, as well as Evans' Index, ventricular height, and transependymal signal were measured. Multivariable statistical models were used to determine which factors were associated with postoperative improvement while we controlled for the presence of the NPH triad. RESULTS: Fifty-nine patients (82%) demonstrated a successful response to surgery at their first postoperative follow-up. However, this declined to 54 patients (75%) at 1 year and 45 (62.5%) patients at their last follow-up. When we controlled for the presence of the triad of symptoms, the CA significantly predicted a good, sustained response to surgery; for every degree decrease in the CA, a patient is 4% more likely to experience benefit from surgery. CONCLUSIONS: The CA is a useful preoperative prognostic tool for predicting which patients will experience a sustained benefit from surgery. Further studies are required to clarify this disease in the context of old age, comorbidity, and possible concomitant neurodegenerative diseases.

Ophthalmic Complications Following Acoustic Neuroma Resection.

BACKGROUND: Past studies have shown high rates of ocular complications with the need for ophthalmic surgery following acoustic neuroma resection (ANR). OBJECTIVE: To determine the rates of ophthalmic complications, referrals, and surgery following ANR, and the factors associated with poor outcomes. METHODS: A retrospective study of ophthalmic outcomes in patients who underwent ANR was conducted, following institutional review board approval. Surgical approach, tumor size, tumor characteristics, completeness of resection, postoperative House-Brackmann grades, ocular complications, referrals to ophthalmology, and ophthalmic treatments were recorded. RESULTS: Between 2007 and 2012, 174 patients underwent ANR. There were 3 surgical groups: retrosigmoid (n = 97), translabyrinthine (n = 59), and combined retrosigmoid and translabyrinthine (n = 18). Median tumor size was 2.2 cm. Postoperatively, 30% of patients had facial nerve dysfunction (House-Brackmann ≥3), which recovered to 19% by 1 mo and 8.6% by 1 yr following ANR. Fifty-six (32.9%) patients experienced ocular complications postoperatively, with lagophthalmos, dry eye, and blurry vision as the most common complications. Thirty-six (67.9%) of the patients who required ophthalmic treatment were managed nonsurgically, with just 13 (7.6%) patients requiring referral to an ophthalmologist. In total, only 9 (5.3%) patients received an ophthalmic procedure. Patients with tumors >2 cm, those undergoing combined retrosigmoid and translabyrinthine resection, and those with severe facial nerve dysfunction which did not improve in the first month following surgery were more likely to have poor ophthalmic outcomes. CONCLUSION: We present lower rates of ophthalmic complications following ANR than previously reported. Improved surgical technique, better postoperative eye care, and facial nerve monitoring most likely accounted for the improved ocular outcomes.

Prognostic Indices for Predicting Facial Nerve Outcome following the Resection of Large Acoustic Neuromas.

This study analyzes the simple ratio of anterior-to-posterior extension of large (>2.5 cm) acoustic neuromas relative to the internal auditory canal (ICA; anterior-posterior [A/P] index) as a tool for predicting risk of facial nerve (FN) injury. In total, 105 patients who underwent microsurgical resection for large acoustic neuromas were analyzed retrospectively. House-Brackmann (HB) scores were assessed immediately postoperatively, at 1 month, and at 1 year. Lateral-medial, inferior-superior, A/P, and maximum diameters were measured from preoperative magnetic resonance images. These measurements and the A/P index were analyzed using univariable and multivariable statistical models to assess relationship to FN outcomes. The retrosigmoid, translabyrinthine, and combined approaches were used, and the extent of resection was evaluated. For every 1 standard deviation increase in the A/P index, a patient was 3.87 times more likely have a higher postoperative HB score ( p < 0.0001). Accordingly, for every 1-mm increase anterior to the IAC, a patient was 16% more likely have a higher postoperative HB score ( p < 0.001). After controlling for tumor size, a patient was still 3.82 times more likely have a higher postoperative HB score for every 1 standard deviation increase in the A/P index ( p < 0.0001). While larger tumor size trended toward worse postoperative HB scores, it was not statistically significant. Our prognostic index may be useful to assess the risk of FN injury preoperatively for large acoustic neuromas, while also providing information about the tumor-nerve relationship.

Identification of Preoperative and Intraoperative Risk Factors for Complications in the Elderly Undergoing Elective Craniotomy.

BACKGROUND: Neurosurgical patients are aging as the general population is becoming older. METHODS: A retrospective review of patients ≥65 years of age who underwent an elective craniotomy from 2007 to 2015 to identify risk factors for 30-day morbidity/mortality was conducted. Key preoperative variables included age, comorbidities, and functional status based on the Karnofsky Performance Status score and modified Rankin Scale score. Outcome variables included long-term care (LTC) complications, neurologic complications, systemic/infectious complications, length of stay, functional outcomes, and mortality. RESULTS: A total of 286 patients ≥65 years underwent elective craniotomy at Loyola University Medical Center over 8 years. Seventy-two patients had a preoperative neurologic deficit and 95 had a systemic morbidity before surgery. Postoperative neurologic and systemic morbidity was 14% and 23%, respectively. 7% of patients experienced a LTC complication and 5 patients (1.7%) died. Worse preoperative scores on both the Karnofsky Performance Status and modified Rankin Scale predicted increased length of stay and mortality (P < 0.05). Univariable and multivariable analyses showed that patients with preoperative motor deficit, altered mental status, congestive heart failure, smoking history, and chronic steroid use were all more likely to have an LTC complication, and increased anesthesia time and estimated blood loss increased risk for LTC, neurologic, and systemic/infectious complications. CONCLUSIONS: This study identifies factors that predict perioperative complications for elderly patients undergoing elective craniotomies, particularly congestive heart failure, smoking history, chronic steroid use, anesthesia time, and estimated blood loss. Age alone should not preclude elective craniotomy.