Undergoing Skull Base Surgery Research Articles

Venous thromboembolism chemical prophylaxis after skull base surgery

PurposeThere is no guidance surrounding postoperative venous thromboembolism (VTE) prophylaxis using pharmacological agents (chemoprophylaxis) in patients undergoing skull base surgery. The aim of this study was to compare VTE and intracranial haematoma rates after skull base surgery in patients treated with/without chemoprophylaxis.MethodsReview of prospective quaternary centre database including adults undergoing first-time skull base surgery (2009–2020). VTE was defined as deep vein thrombosis (DVT) and pulmonary embolism (PE) within 6 months of surgery. Multivariate logistic regression was used to determine factors predictive of postoperative intracranial haematoma/VTE. Propensity score matching (PSM) was used in group comparisons.ResultsOne thousand five hundred fifty-one patients were included with a median age of 52 years (range 16–89 years) and female predominance (62%). Postoperative chemoprophylaxis was used in 81% of patients at a median of 1 day postoperatively. There were 12 VTE events (1.2%), and the use of chemoprophylaxis did not negate the risk of VTE entirely (p > 0.99) and was highest on/after postoperative day 6 (9/12 VTE events). There were 18 intracranial haematomas (0.8%), and after PSM, chemoprophylaxis did not significantly increase the risk of an intracranial haematoma (p > 0.99). Patients administered chemoprophylaxis from postoperative days 1 and 2 had similar rates of intracranial haematomas (p = 0.60) and VTE (p = 0.60), affirmed in PSM.ConclusionPostoperative chemoprophylaxis represents a relatively safe strategy in patients undergoing skull base surgery. We advocate a personalised approach to chemoprophylaxis and recommend it on postoperative days 1 or 2 when indicated.

Endoscopic endonasal resection of craniovertebral junction osteomyelitis: illustrative cases

Operative management of craniovertebral junction (CVJ) osteomyelitis has traditionally been extracranial and focused on debriding the infection. In select patients, the endoscopic endonasal approach (EEA) with a focus on additional resection versus debridement may be preferred. The goal of this study is to present the authors' experience with the EEA with gross or subtotal resection for the treatment of osteomyelitis at the CVJ and describe their technique in the context of the literature. Two patients of the authors' and 6 detailed case reports in the literature were identified with a mean age of 58.9 years. Most patients (n = 5; 62.5%) underwent skull base surgery and debridement (n = 5; 62.5%). Although more common, debridement was inferior to resection in terms of neurological improvement (66.7% vs. 100.0%) postoperatively. The majority (n = 7; 87.5%) of patients underwent occipitocervical fusion. Osteomyelitis is an exceedingly rare lesion of the CVJ. Despite the region's delicate biomechanical stability, resection of infected bone may be superior to debridement alone in terms of clinical outcome. Given how well established the safety of the EEA is to this region, further study of outcomes with resection is warranted.

Salvage Endoscopic Skull Base Surgery: Another Treatment Option After Immunotherapy for Recurrent Nasopharyngeal Carcinoma.

BackgroundAdvanced recurrent nasopharyngeal carcinoma (NPC) is a relatively common nasopharyngeal skull base disease for which there is no uniform treatment modality. Not all patients are satisfied with the efficacy of immunotherapy with or without chemotherapy.MethodsThis study included patients who underwent salvage endoscopic skull base nasopharyngectomy after immunotherapy between February 2017 and June 2021. Patient survival information was analyzed. Relevant publications were retrieved from five databases from December 1, 2011 to December 1, 2021. The outcomes of patients with advanced recurrent NPC who received programmed death 1 (PD-1) immunotherapy were collected and analyzed.ResultsNine patients who underwent skull base surgery, all of whom had previously undergone PD-1 immunotherapy, were included in this study. The 2-year overall survival (OS) and progression-free survival (PFS) rates of these patients were 25% and 29.2%, respectively. Eight publications involving 688 patients with advanced recurrent NPC were also included in this study. The combined complete response (CR), partial response (PR), and stable disease (SD) values were 2%, 23%, and 29%, respectively. The combined DCR included the three disease conditions, CR, PR, and SD, with a value of 53%. PD-1 monotherapy was more effective than PD-1 combination chemotherapy.ConclusionsPD-1 immunotherapy may improve the remission rate in patients with recurrent NPC. Salvage endoscopic skull base nasopharyngectomy may be another option for patients with poor immunotherapeutic outcomes. For patients with advanced recurrent NPC, better evidence-based medical data are needed to determine whether they should receive immunotherapy before or after surgery.

Anterior skull base reconstruction using an anterolateral thigh free flap.

BackgroundGaleal or temporalis muscle flaps have been traditionally used to reconstruct skull base defects after tumor removal. Unfortunately, these flaps do not provide sufficient vascularized tissue for a dural seal in extensive defects. This study describes the successful coverage of large skull base defects using anterolateral thigh (ALT) free flaps.MethodsThis retrospective study included five patients who underwent skull base surgery between June 2018 and June 2021. Reconstruction was performed using an ALT free flap to cover defects that included the intracranial space and extended to the frontal sinus and cribriform plate.ResultsThere were no major complications, such as ascending infections or cerebrospinal leakage. Postoperative magnetic resonance imaging showed that the flaps were well-maintained in all patients.ConclusionSuccessful reconstruction was performed using ALT free flaps for large anterior skull base defects. In conclusion, the ALT free flap is an effective option for preventing communication between the nasal cavity and the intracranial space.

Rate of Development of Venous Thromboembolism in Lateral Skull Base Surgery.

Venous thromboembolism (VTE) is a major cause of morbidity and mortality for surgical patients. This article aims to determine factors that may have contributed to the development of VTE in patients undergoing lateral skull base surgery, to assess the validity of the Caprini Risk Assessment Model (RAM) score in this subset of patients, and to determine the efficacy of mechanical DVT prophylaxis alone in preventing VTE. Retrospective chart review. A retrospective chart review was conducted of patients who underwent skull base surgery for vestibular schwannoma, and the rate of VTE was assessed. Patient demographics, comorbidities, and treatment factors were examined to determine risk factors associated with the development of a postoperative thrombotic event. Caprini RAM scores were compared for patients who developed a VTE. Among 197 patients, the rate of VTE formation was 3.5%. No individual risk factor independently contributed to the development of a thrombotic event. The mean Caprini RAM score was 4.06 in patients who did not develop a VTE and 5.14 in the patients that did develop a VTE (P=.005). The Caprini score was significant for the risk of VTE formation, with an odds ratio of 2.8 (P=.009, 95% CI=1.3-6.2). Venous thromboembolism rates are relatively low following lateral skull base surgery. While there is no individual risk factor associated with increased VTE risk, the Caprini RAM score appears to be a useful predictor of risk. The Caprini score may be useful in identifying high-risk patients who may benefit from chemoprophylaxis for VTE prevention. 3 Laryngoscope, 132:662-667, 2022.

Frailty as a Predictor of Postoperative Complications Following Skull Base Surgery.

Frailty has emerged as a powerful risk stratification tool across surgical specialties; however, an analysis of the impact of frailty on outcomes following skull base surgery has not been published. The aim of this study was to assess the validity of the 5-factor modified frailty index (mFI-5) as a predictor of perioperative morbidity and mortality in patients undergoing skull base surgery. A mFI-5 score was calculated for patients undergoing skull base surgeries using the National Surgical Quality Improvement Program (NSQIP) database from 2005 to 2018. Multivariate logistic regression analysis was used to evaluate the association of increasing frailty with complications in the 30-day postoperative period, with a subanalysis by operative location. A total of 17,912 patients who underwent skull base procedures were identified, with 45.5% of patients having a frailty score of one or greater; 44.9% were male and the mean age was 52.0 (±16.1 SD) years. Multivariable regression analysis revealed frailty to be an independent predictor of overall complications (odds ratio [OR]: 1.325, P < .001), life-threatening complications (OR: 1.428, P < .001), and mortality (OR: 1.453, P < .001). Higher frailty also correlated with increased length of stay. When procedures were stratified by operative location, frailty correlated significantly with overall complications for middle, posterior, and multiple-fossae operations but not the anterior fossa. Frailty demonstrates a significant and stepwise association with life-threatening postoperative morbidity, mortality, and length of stay following skull base surgeries. mFI-5 is an objective and easily calculable measure of preoperative risk, which may facilitate perioperative planning and counseling regarding outcomes prior to surgery. 3 Laryngoscope, 131:1977-1984, 2021.

Short-Term Morbidity and Predictors of Adverse Events Following Esthesioneuroblastoma Surgery.

The short-term adverse events and predictors of morbidity in surgical resection of esthesioneuroblastoma (ENB) are largely unknown, and investigating these variables can help direct planning for at-risk patients. The 2005-2017 National Surgical Quality Improvement Program database was queried to identify patients with a diagnosis of ENB undergoing skull base surgery for tumor resection. Information regarding demographics, patient morbidity score, pre-operative and intra-operative data, and post-operative outcomes were extracted. Cox proportional hazard analysis was utilized to assess complication and readmission/reoperation rates. A total of 95 patients undergoing skull base surgery for resection of ENB were included. Mean age, BMI, operation time, and post-operative length of stay (LOS) of the cohort were 53.6 ± 16.2 years, 29.1 ± 6.5, 392.0 ± 204.6 minutes, and 5.8 ± 4.6 days, respectively. In total, 31 patients (32.6%) experienced at least one 30-day adverse event, which included blood transfusion intra-operatively or within 72 hours from the operation (22.1%), readmission (10.7%), intubation >48 hours (7.4%), reintubation (4.2%), organ or space infection (4.2%), reoperation (4.0%), superficial or deep surgical site infection (2.1%), sepsis (2.1%), pulmonary embolism (1.1%), and myocardial infarction (1.1%). Patients who experienced at least one adverse event had significantly higher operation time (486.8 ± 230.4 vs. 347.5 ± 176.2 minutes, p = 0.002), LOS (9.2 ± 5.6 days vs. 4.2 ± 3.0, p < 0.001), and lower hematocrit (37.3 ± 5.9 vs. 41.2 ± 3.8, p < 0.001) and albumin levels (3.8 ± 0.6 vs. 4.2 ± 0.3, p = 0.009). Patients with a higher American Society of Anesthesiologists (ASA) score (HR = 2.39; p = 0.047) or longer operation time (HR = 1.004; p = 0.001) had a significantly higher risk for experiencing adverse events. Obesity was not associated with different intra- or post-operative outcomes, but older patients had shorter operations (p = 0.002) and LOS (p = 0.0014). Longer operation time and lower pre-operative hematocrit and albumin levels may all increase complication rates in ENB resection. Patients with high ASA score or more advanced age may have different short-term outcomes.

Clinical utility of apparent diffusion coefficient and diffusion‐weighted magnetic resonance imaging for resectability assessment of head and neck tumors with skull base invasion

The usefulness of apparent diffusion coefficient (ADC) and diffusion-weighted magnetic resonance imaging (DWI) in the detection of malignant tumors has been reported. The purpose of this study is to clarify the role of ADC and DWI for diagnosis of skull base tumors. A total of 27 patients with head and neck tumors with skull base invasions undergoing skull base surgery were enrolled in this study. Pathological findings of dural invasion and bone invasion were compared with the diagnostic imaging. Advanced magnetic resonance imaging techniques revealed that ADC values in regions of pathological bone and dural invasions were significantly lower than in regions of no invasion. The area under the curve of ADC in bone invasions and dural invasions were 0.957 and 0.894, respectively. Our findings indicate that ADC and DWI are useful tools for the diagnosis of head and neck tumors with skull base invasion.

Diverse phenotypes and endotypes of fungus balls caused by mixed bacterial colonization in chronic rhinosinusitis.

The pathogenic roles of fungus and bacteria in chronic rhinosinusitis (CRS) remain unclear. Recently, we described the bacterial ball, which is distinct from the fungus ball, as an unusual phenotype of bacterial infection. In this study, we investigated the clinical, histopathologic, and immunologic characteristics of sinonasal microorganic materials, including fungus ball and bacterial ball. In this study, we enrolled 80 CRS patients with sinonasal microorganic materials and 10 control subjects who underwent skull base surgery or endoscopic dacryocystorhinostomy and had no signs or symptoms of nasal inflammation. All specimens were stained with hematoxylin-eosin, Gomori-methenamine-silver, and Gram stain to identify fungal organisms and Gram-positive/negative bacterial colonies. The expression of tumor necrosis factor (TNF)-α; interleukin (IL)-1β; S100A7; S100A8/A9; and short, palate, lung, and nasal epithelial clone 1 (SPLUNC1) were evaluated by enzyme-linked immunosorbent assay using sinus lavage fluid. We histologically classified sinonasal microorganic materials into the following 4 groups: fungus ball (n = 45); bacterial ball (n = 6); mixed ball (formed by a mixture of fungus and bacteria, n = 27); and double ball (formed by separate fungal and bacterial balls, n = 2). Compared with the fungus ball, the mixed ball was more frequently detected in immunocompromised patients (p < 0.0001). In addition, TNF-α expression was significantly higher in fungus and mixed balls than in control, whereas the mixed ball showed higher expression of IL-1β compared with the fungus ball. Moreover, the expression of S100A7 and S100A8/A9 protein in the mixed ball was significantly decreased when compared with the fungus ball, whereas there was no significant difference in SPLUNC1 expression between fungus and mixed balls. Our findings suggest that fungal and bacterial interactions are diverse in CRS. Specifically, the mixed ball is prevalent in CRS with an immunocompromised state and it may decrease epithelial barrier function.

Timing of Postoperative CSF Leak after Endoscopic Skull Base Surgery in Patients with Obstructive Sleep Apnea.

Background There is little data regarding postoperative outcomes of patients with obstructive sleep apnea (OSA) undergoing skull base surgery. The purpose of this study is to determine an association between risk factors and proximity of cerebrospinal fluid (CSF) leak to surgery in patients with OSA undergoing endoscopic skull base surgery. Methods A retrospective review of neurosurgical inpatients, with and without OSA, at a tertiary care institution from 2002 to 2015 that experienced a postoperative CSF leak after undergoing endoscopic skull base surgery. Results Forty patients met inclusion criteria, 12 (30%) with OSA. OSA patients had significantly higher body mass index (BMI; median 39.4 vs. 31.7, p < 0.01) and were more likely to have diabetes (41.7 vs. 10.7%, p = 0.04) than non-OSA patients; otherwise there were no significant differences in clinical comorbidities. No patients restarted positive pressure ventilation (PPV) in the inpatient setting. The type of repair was not a significant predictor of the time from surgery to leak. Patients with OSA experienced postoperative CSF leak 49% sooner than non-OSA patients (Hazard Ratio 1.49, median 2 vs. 6 days, log-rank p = 0.20). Conclusion Patients with OSA trended toward leaking earlier than those without OSA, and no OSA patients repaired with a nasoseptal flap (NSF) had a leak after postoperative day 5. Due to a small sample size this trend did not reach significance. Future studies will help to determine the appropriate timing for restarting PPV in this high risk population. This is important given PPV's significant benefit to the patient's overall health and its ability to lower intracranial pressure.

Postoperative Continuous Positive Airway Pressure Use and Nasal Saline Rinses After Endonasal Endoscopic Skull Base Surgery in Patients With Obstructive Sleep Apnea: A Practice Pattern Survey.

Endoscopic skull base surgery continues to evolve in its indications, techniques, instrumentation, and postoperative care. As surgery of the skull base will often violate dura, intraoperative and postoperative cerebrospinal fluid (CSF) leak is not uncommon and represents a potential conduit for air and bacterial contamination. Patients with obstructive sleep apnea (OSA) requiring continuous positive airway pressure (CPAP) therapy undergoing skull base surgery represent a challenging group. However, there appears to be a paucity of consensus regarding the postoperative management of this patient population. The objective of this study is to examine practice patterns and expert opinion on the use of postoperative CPAP and nasal saline in patients with OSA. A 14-item survey was generated by consensus among expert authors and distributed online to members of the North American Skull Base society and other international skull base community members. Data were analyzed for median, mean, and standard deviation variables. Subgroup analysis was completed between surgeons from different geographical locations and operative experience. SPSS22 was utilized for all complex statistical analysis and figures. Seventy-one responses were collected from skull base surgeons. In patients with OSA, respondents would resume patients' CPAP therapy after a mean of 10.1 days (median, 7; standard deviation [SD], 10.2), without a CSF leak. In the presence of a small CSF leak, the mean duration would increase to 14.3 days (median, 14; SD, 9.8) and to 20.7 days (median, 21; SD, 11.8) in the presence of a larger leak. A surgeon's choice to attribute the relationship between delaying the start of nasal saline and CPAP after the endoscopic skull base surgery with progressively more challenging skull base repair was found to be statistically significant ( P < .001). Saline and CPAP therapies are initiated after the endoscopic skull base surgical repairs by surgeons at an increasing temporal delay in relation to the degree and complexity of the skull base defect repaired.

Outcomes of Open vs Endoscopic Skull Base Surgery in Patients 70 Years or Older

The use of skull base surgery in patients 70 years or older is increasing, but its safety in this age group has not been evaluated to date. To describe outcomes in a cohort of patients 70 years or older undergoing skull base surgery and to evaluate whether age, type of disease process, and approach (endoscopic vs traditional open surgery) are associated with increased intraoperative and postoperative complications in this population. This retrospective cohort study analyzed a population-based sample of 219 patients 70 years or older from a database of 1720 patients who underwent skull base surgery at University of North Carolina Hospitals, Chapel Hill, a tertiary referral center, between October 2007 and June 2017. Data were collected from June 2016 to July 2017 and analyzed in July 2017 and August 2017. Skull base surgery. Data collected included demographic characteristics, surgical approach, and disease process. Intraoperative findings and postoperative complications were analyzed by age, surgical approach, and malignancy status. Of the 219 patients, 166 were aged 70.0 to 79.9 years and 53 patients were older than 80 years (mean [SD] age, 76.4 [4.7] years); 120 (54.8%) were men and 160 (73.7%) were white. There were 161 (73.5%) endoscopic and 58 (26.5%) open operations. The most common pathologic processes among the 219 patients were nonsellar malignant (81 [37.0%]), nonsellar benign (53 [24.2%]), and pituitary (49 [22.4%]) tumors. The most common intraoperative and postoperative complications were intraoperative major bleeding (5 of 219 patients [2.3%]) and postoperative bleeding (9 [4.1%]). Thirty-day mortality was zero. There was no clinically meaningful difference in complications between patients aged 70.0 to 79.9 years vs those older than 80 years, endoscopic vs open surgery, or benign vs malignant neoplasms. Specifically, between the endoscopic and open surgery groups, there was no difference in intraoperative major bleeding (3.9%; 95% CI, -0.7% to 12.9%), postoperative cerebrospinal fluid leak (-0.6%; 95% CI, -3.4% to 5.6%), or postoperative bleeding (1.5%; 95% CI, -3.9% to 10.6%). Skull base surgery is a safe option in persons 70 years or older, with similar outcomes across age ranges, surgical approaches, and disease processes.

Outcomes of Craniofacial Open Surgery in Octogenarians.

Introduction The steady increase in average life expectancy has led to a rise in the number of referrals of elderly patients for major operations. It is not clear whether age itself is a risk factor for morbidity and mortality after skull base operations. We investigated a possible link among a cohort of patients older than 80 years of age who underwent those surgeries in our department. Methods We conducted a retrospective analysis of all patients who underwent skull base surgery at the TASMC (Tel Aviv Sourasky Medical Center) between 2000 and 2016. Results A total of 369 patients underwent open skull base surgeries in our institution, and 13 were patients older than 80 years. The median age of the octogenarians was 83.4 (range 80-89), and the male-to-female ratio was 7:6. Twelve patients had major systemic comorbidities. Four patients had major complications associated with surgery: three had early wound complications, and one each had early central nervous system complications, early and late systemic complications, and late orbital complications. This complication rate is comparable to that of our younger group of 356 patients. The overall survival rate was measured for 30 days, 1 year, and 3 years, and it was not significantly different between the octogenarians and that of the younger patients. Further comparison of the elderly group with 13 matched younger patients revealed no difference of morbidity and mortality between the two groups. Conclusions Despite their systemic comorbidities, the morbidity and mortality rates associated with skull base surgery in octogenarians appear to be comparable to that of younger patients undergoing the same procedures.

Examining Skull Base Surgeon Practice Patterns for Patients with OSA Undergoing Skull Base Surgery

Examining Skull Base Surgeon Practice Patterns for Patients with OSA Undergoing Skull Base Surgery

Complications in Salvage Surgery for Nasal and Paranasal Malignant Tumors Involving the Skull Base.

Objective Nasal and paranasal malignant tumors invading the skull base are rare and poorly studied. We evaluated postoperative complications in patients undergoing salvage surgery for such tumors. Design Retrospective study. Setting Kobe University Hospital. Participants Among 48 patients who underwent surgery for tumors involving the skull base between 1993 and 2015, 21 patients had squamous cell carcinoma, 13 had olfactory neuroblastoma, 5 had adenocarcinoma, 2 had sarcoma, 2 had adenoid cystic carcinoma, and 1 each had malignant melanoma, poorly differentiated carcinoma, undifferentiated carcinoma, myoepithelial carcinoma, and malignant peripheral nerve sheath tumor. Prior to skull base surgery, radiotherapy, chemoradiotherapy (CRT), particle radiotherapy, chemotherapy, or surgery were applied in 3, 15, 4, 5, and 3 patients, respectively. Main Outcome Measures Main outcome measures were postoperative complications in patients who underwent skull base surgery after concomitant CRT and/or particle therapy. Results Major postoperative complications were observed in 14 surgical procedures (29%; 2 patients with cerebral herniation, 3 with cerebrospinal fluid leakages, 3 with meningitis, 1 with hydrocephalus, 6 with epidural abscesses, 2 with local infections, and 2 with partial flap necrosis). Four patients developed ≥2 complications. One patient died of postoperative lung infarction. Three (16.7%) of 18 patients without prior treatment and 9 (50%) of 18 patients who underwent preoperative radiotherapy/CRT had severe postoperative complications. Two (50%) of four patients treated with particle radiotherapy had postoperative complications. Conclusions CRT or particle radiotherapy were significantly associated with a high risk of severe postoperative complications after skull base surgery. Meticulous care should be taken in patients treated with radiotherapy/particle therapy prior to skull base surgery.

Long-term olfactory outcome after nasoseptal flap reconstructions in midline skull base surgery.

The nasoseptal flap (NSF) is a universally used surgical technique to cover defects of the skull base after extended sinonasal surgery. Long-term follow-up of complications, sequelae, and smell function is largely unknown. The main objective of this study was to investigate monorhinal olfaction after transsphenoidal skull base surgery. Patients who underwent skull base surgery for midline lesions (craniopharyngioma and pituitary tumors) by using a NSF, also referred to as the Haddad flap, were assessed for their long-term outcome. Endoscopic examination was conducted and the bilateral "Sniffin' Sticks" test was performed before surgery. Each side was tested separately in the postoperative follow-up consultation. Twenty patients were included in the study. No flap failures were observed. One anterior perforation and one small posterior septal perforation were found during long-term follow-up. None of the patients had nasal breathing impairment, whereas two patients had nose bleeds. A significant decrease in olfactory function was observed on the flap donor side in four patients (20%) compared with that observed in one patient (5%) on the opposite side. NSF reconstructions for midline lesions were efficient and safe in the long term. Olfactory impairment on the donor side was frequently encountered. Although subclinical, these findings justified a monorhinal smell testing before surgery, which possibly prevented bilateral smell impairment in patient with preexisting single-sided olfactory loss.

Safety and Efficacy of TachoSil (Absorbable Fibrin Sealant Patch) Compared With Current Practice for the Prevention of Cerebrospinal Fluid Leaks in Patients Undergoing Skull Base Surgery: A Randomized Controlled Trial.

Cerebrospinal fluid (CSF) leakage associated with incomplete sealing of the dura mater is a major complication of intradural procedures. To compare the efficacy and safety of adjunctive TachoSil (Takeda Pharma A/S, Roskilde, Denmark) with current practice for the prevention of postoperative CSF leaks in patients undergoing elective skull base surgery involving dura mater closure. Patients were intraoperatively randomized to TachoSil or current practice immediately before primary dura closure by suturing ± duraplasty. Choice of adjunctive treatment in the current practice group was at the surgeon's discretion. Primary efficacy endpoint was occurrence of clinically evident verified postoperative CSF leak or clinically evident pseudomeningocele within 7 weeks after surgery or treatment failure (third application of trial treatment or use of other treatment). A total of 726 patients were randomized to TachoSil (n = 361) or current practice (n = 365). More current practice patients had sutures plus duraplasty for primary dura closure compared with TachoSil (49.6% vs 35.7%) and fewer had sutures only (45.5% vs 63.2%). The primary endpoint of estimated leak rate favored TachoSil with events in 25 (6.9%) patients vs 30 (8.2%) current practice patients; however, this was not statistically significant (odds ratio: 0.82; 95% confidence interval: 0.47, 1.43; P = .485). Both treatments were well tolerated with similar frequency of adverse events. Very low rates of postoperative CSF leaks can be achieved in patients undergoing skull base surgery of various indications. Although the study did not meet its primary endpoint, TachoSil appears to be safe and effective for the prevention of CSF leaks and associated complications.

Incidence of Posttraumatic Stress Disorder (PTSD) Symptoms in Skull Base Surgery

Objective: To assess the incidence of posttraumatic stress disorder (PTSD) symptoms in patients undergoing elective skull base surgery in comparison to other elective brain surgery. Methods: A prospective cohort study of patients undergoing elective brain surgery was examined. The incidence of development of PTSD symptoms was evaluated in comparison between general cranial cases and skull base cases using a structured clinical interview (SCID) and a battery of standardized questionnaires before surgery as well as 1 week and 3 months postoperatively. In addition, the short form SF36 and EuroQOL-3D were completed preoperatively and at 3 months postoperatively. Results: A prospective cohort study of 36 patients undergoing elective brain surgery was examined. Nine patients (25%) had skull base surgery. Before surgery the PTSD symptoms were reported in two (22%) and two cases (7%) in the skull base and general cranial cases, respectively. At 3 months follow-up PTSD symptoms were observed in two (22%) and three patients (11%) in the skull base and general cranial cases, respectively. Conclusions: Our results reveal that PTSD symptoms have initially a higher incidence in patients undergoing skull base surgery. Further research is needed to determine the relevant incident triggering the PTSD symptoms. Psychological support is needed for patients suffering from PTSD symptoms as we could observe stabilization in the symptoms also at 3 months follow-up.

Somatosensory Evoked Potentials Help Prevent Positioning‐Related Brachial Plexus Injury during Skull Base Surgery

Evaluate the use of somatosensory evoked potentials (SSEP) monitoring to detect positioning-related brachial plexus injury during skull base surgery. Prospective cohort observational study. University Hospital. Patients undergoing skull base surgery had a focused neurologic exam of the brachial plexus performed before and after surgery. Under stable anesthesia, brachial plexus SSEP values were obtained before and after surgical positioning. Significant SSEP changes required a readjustment of arm or neck positions. SSEPs were assessed every 30 minutes. If changes were noted, position was readjusted and SSEPs were reassessed until surgical completion. Demographic data, neurologic exams, SSEP latency, and amplitude values were recorded. Persistent changes were correlated with postoperative neurologic findings. Sixty-five patients, 15 to 77 years old, were studied. Six patients (9.2%) developed SSEP amplitude changes after positioning (average amplitude decrease 72.8%). One patient had a significant latency increase. The sensitivity of SSEP for detection of injury was 57%, while specificity was 94.7%. The average body mass index (BMI) of patients with normal and abnormal SSEPs was 28.7 ± 5.6 versus 29.2 ± 8.0, respectively. Average BMI of patients with postoperative symptoms regardless of SSEP findings was 33.8 ± 4.3. Two patients who had persistent SSEP changes after positioning had BMIs of 40.1 and 31.2 kg/m(2), respectively. Improvement in neurologic findings occurred in all patients after surgery. This study demonstrates that upper extremity nerve stress can be detected in real time using SSEP and may be of value in protecting patients from nerve injury undergoing lateral skull base surgery.

New dried human amniotic membrane is useful as a substitute for dural repair after skull base surgery.

Objectives Cerebrospinal fluid (CSF) leakage is an undesirable complication of skull base surgery. We used dried human amniotic membrane (AM) as a patch graft for dural repair to determine its efficacy in preventing CSF leakage. Design Frontoparietal craniotomy and removal of dura were performed in 20 Wistar rats. A dried AM was placed to cover the dural defect without suturing in 16 animals. In four animals, an expanded polytetrafluoroethylene was implanted. At 2 weeks and 1, 3, and 6 months, histological examination was performed. Dried AM was also used as a substitute in 10 patients who underwent skull base surgery, after approval by the Ethics Committee of the University of Toyama. Results At 2 weeks after implantation, thick connective tissue completely enclosed the dried AM. At 1 month after implantation, the connective tissue became thin and the implanted AM shortened. At 3 and 6 months after implantation, histological examination revealed disappearance of the dried AM and formation of membranous tissue. In the clinical study, neither CSF leakage nor clinical adverse reactions directly related to the dried AM were observed. Conclusion Dried human AM appears to be an ideal substitute for dura, since it is replaced by natural tissue.