Direct (D)-Wave Monitoring Enhancement With Subdural Electrode Placement: A Case Series.

PURPOSE: Direct-wave (D-wave) neuromonitoring is a direct measure of corticospinal tract integrity that detects potential injury during spinal cord surgery. Epidural placement of electrodes used for D-wave measurements can result in high electrical impedances resulting in substantial signal noise that can compromise signal interpretation. Subdural electrode placement may offer a solution. METHODS: Medical records for consecutive patients with epidural and subdural D-wave monitoring were reviewed. Demographic and clinical information including preoperative and postoperative motor strength were recorded. Neuromonitoring charts were reviewed to characterize impedances and signal amplitudes of D-waves recorded epidurally (before durotomy) and subdurally (following durotomy). Nonparametric statistics were used to compare epidural and subdural D-waves. RESULTS: Ten patients (50% women, median age 50.5 years) were analyzed, of which five patients (50%) were functionally independent (modified McCormick grade ≤ II) preoperatively. D-waves were successfully acquired by subdural electrodes in eight cases and by epidural electrodes in three cases. Subdural electrode placement was associated with lower impedance values ( P = 0.011) and a higher baseline D-wave amplitude ( P = 0.007) relative to epidural placement. No association was observed between D-wave obtainability and functional status, and no adverse events relating to subdural electrode placement were encountered. CONCLUSIONS: Subdural electrode placement allows successful D-wave acquisition with accurate monitoring, clearer waveforms, and a more optimal signal-to-noise ratio relative to epidural placement. For spinal surgeries where access to the subdural compartment is technically safe and feasible, surgeons should consider subdural placement when monitoring D-waves to optimize clinical interpretation.

Transforming Otolaryngology-Head and Neck Surgery: The Pivotal Role of Artificial Intelligence in Clinical Workflows.

Use of artificial intelligence (AI) is expanding exponentially as it pertains to workflow operations. Otolaryngology-Head and Neck Surgery (OHNS), as with all medical fields, is just now beginning to realize the exciting upsides of AI as it relates to patient care but otolaryngologists should also be critical when considering using AI solutions. This paper highlights how AI can optimize clinical workflows in the outpatient, inpatient, and surgical settings while also discussing some of the possible drawbacks with the burgeoning technology.

Intraoperative Monitoring of the External Urethral Sphincter Reflex: A Novel Adjunct to Bulbocavernosus Reflex Neuromonitoring for Protecting the Sacral Neural Pathways Responsible for Urination, Defecation and Sexual Function.

PURPOSE: Intraoperative bulbocavernosus reflex neuromonitoring has been utilized to protect bowel, bladder, and sexual function, providing a continuous functional assessment of the somatic sacral nervous system during surgeries where it is at risk. Bulbocavernosus reflex data may also provide additional functional insight, including an evaluation for spinal shock, distinguishing upper versus lower motor neuron injury (conus vs. cauda syndromes) and prognosis for postoperative bowel and bladder function. Continuous intraoperative bulbocavernosus reflex monitoring has been utilized to provide the surgeon with an ongoing functional assessment of the anatomical elements involved in the S2-S4 mediated reflex arc including the conus, cauda equina and pudendal nerves. Intraoperative bulbocavernosus reflex monitoring typically includes the electrical activation of the dorsal nerves of the genitals to initiate the afferent component of the reflex, followed by recording the resulting muscle response using needle electromyography recordings from the external anal sphincter. METHODS: Herein we describe a complementary and novel technique that includes recording electromyography responses from the external urethral sphincter to monitor the external urethral sphincter reflex. Specialized foley catheters embedded with recording electrodes have recently become commercially available that provide the ability to perform intraoperative external urethral sphincter muscle recordings. RESULTS: We describe technical details and the potential utility of incorporating external urethral sphincter reflex recordings into existing sacral neuromonitoring paradigms to provide redundant yet complementary data streams. CONCLUSIONS: We present two illustrative neurosurgical oncology cases to demonstrate the utility of the external urethral sphincter reflex technique in the setting of the necessary surgical sacrifice of sacral nerve roots.

Novel Standalone Motion-Sparing Pelvic Fixation Prevents Short-Term Insufficiency Fractures After Midsacrectomies Without Sacrificing Normal, Mobile Lumbar Segments Traditionally Used for Stabilization.

BACKGROUND AND OBJECTIVES: Sacrectomy is often the treatment of choice to provide the greatest chance of progression-free and overall survival for patients with primary malignant bone tumors of the sacrum. After midsacrectomy, the stability of the sacropelvic interface is diminished, resulting in insufficiency fractures. Traditional stabilization involves lumbopelvic fixation but subjects normal mobile segments to fusion. The purpose of this study was to determine whether standalone intrapelvic fixation is a safe adjunct to midsacrectomy, avoiding both sacral insufficiency fractures and the morbidity of instrumenting into the mobile spine. METHODS: A retrospective study identified all patients who underwent resection of sacral tumors at 2 comprehensive cancer centers between June 2020 and July 2022. Demographic, tumor-specific, operative characteristics and outcome data were collected. The primary outcome was presence of sacral insufficiency fractures. A retrospective data set of patients undergoing midsacrectomy without hardware placement was collected as a control. RESULTS: Nine patients (5 male, 4 female), median age 59 years, underwent midsacrectomy with concomitant placement of standalone pelvic fixation. No patients developed insufficiency fractures during the 216 days of clinical and 207 days of radiographic follow-up. There were no adverse events attributable to the addition of standalone pelvic fixation. In our historical cohort of partial sacrectomies without stabilization, there were 4/25 patients (16%) with sacral insufficiency fractures. These fractures appeared between 0 and 5 months postoperatively. CONCLUSION: A novel standalone intrapelvic fixation after partial sacrectomy is a safe adjunct to prevent postoperative sacral insufficiency fractures in patients undergoing midsacrectomy for tumor. Such a technique may allow for long-term sacropelvic stability without sacrificing mobile lumbar segments.

Direct Wave Intraoperative Neuromonitoring for Spinal Tumor Resection: A Focused Review.

At present, surgical resection of primary intramedullary spinal cord tumors is the mainstay of treatment. However, given the dimensional constraints of the narrow spinal canal and dense organization of the ascending and descending tracts, intramedullary spinal cord tumor resection carries a significant risk of iatrogenic neurological injury. Intraoperative neurophysiological monitoring (IONM) and mapping techniques have been developed to evaluate the functional integrity of the essential neural pathways and optimize the surgical strategies. IONM can also inform on impending harm to at-risk structures and can correlate with postoperative functional recovery if damage has occurred. Direct waves (D-waves) will provide immediate feedback on the integrity of the lateral corticospinal tract. In the present review, we have provided an update on the utility of D-waves for spinal cord tumor resection. We have highlighted the neuroanatomical and neurophysiological insights from the use of D-wave monitoring, the technical considerations and limitations of the D-wave technique, and multimodal co-monitoring with motor-evoked potentials and somatosensory-evoked potentials. Together with motor-evoked potentials, D-waves can help to guide the extent of tumor resection and provide intraoperative warning signs and alarm criteria to direct the surgical strategy. D-waves can also serve as prognostic biomarkers for long-term recovery of postoperative motor function. We propose that the use of D-wave IONM can contribute key findings for clinical decision-making during spinal cord tumor resection.

Subdural Direct Wave Intraoperative Neurophysiological Monitoring in Intramedullary Spinal Cord Tumor Resection: Case Report.

Direct wave (D-wave) intraoperative neurophysiological monitoring (IONM) is used during intramedullary spinal cord tumor (IMSCT) resection to assess corticospinal tract (CST) integrity. There are several obstacles to obtaining consistent and reliable D-wave monitoring and modifications to standard IONM procedures may improve surgical resection. We present the case of a subependymoma IMSCT resection at the T2-T6 spinal levels where subdural D-wave monitoring was implemented. A 47-year-old male was presented with a five-year history of numbness in his right foot eventually worsening to sharp upper back pain with increased lower extremity spasticity. MRI revealed an expansile non-contrast enhancing multi-loculated cystic lesion spanning T2-T6 as well as a separate T1-T2 lesion. A T2-T6 laminoplasty was performed for intramedullary resection of the lesion. A spinal electrode was placed in the epidural space caudal to the surgical site to monitor CST function; however, action potentials could not be obtained. Post durotomy, the electrode was placed in the subdural space under direct visualization. This resulted in a reliable D-wave recording, which assisted surgical decision-making during the procedure upon D-wave and limb motor evoked potential attenuation. Surgical intervention led to the recovery of the D-wave recording. Subdural D-wave monitoring serves as an alternative in patients where reliable D-waves from the epidural space are unable to be obtained. Further investigation is required to improve the recording technique, including exploring various types of contacts and lead placement locations.

Intradural Extramedullary Solitary Fibrous Tumor of the Thoracic Spinal Cord.

Solitary fibrous tumors (SFTs) are rare soft tissue neoplasms that can impact the central nervous system (CNS). SFTs comprise <1% of all primary CNS tumors. Here, we describe a rare case of intradural, extramedullary SFT arising within the thoracic spine that was treated with surgical resection. Histological features were evaluated and revealed a highly cellular tumor with positive expression of BCL2, CD34, CD99, and STAT6 proteins that are consistent with a diagnosis of SFT. We discuss the use of surgical intervention for long-term disease control of spinal SFT and evaluate the role of postoperative radiation therapy in management strategies. Lastly, we review the literature reports of intradural, extramedullary SFTs in the thoracic spine. The importance of molecular characterization by histopathology to properly determine diagnosis and prognosis is emphasized.

Delayed Surgical Intervention in Acute Subdural Hematoma.

Background Current guidelines recommend an acute subdural hematoma (ASDH) with a thickness greater than or equal to 10 mm or a midline shift greater than or equal to 5 mm be evacuated regardless of Glasgow Coma Scale (GCS). A large craniotomy versus craniectomy is the preferred surgical treatment for ASDH. A subset of patients who are typically older if not elderly meet the above criteria but have a monitorable neurologic exam. These patients can be followed and taken in a delayed manner allowing the ASDH to become chronic. The delay in treatment allows for a smaller surgery in regards to size of incision, size of craniotomy, and duration of anesthesia.  Methods Between February 2013 and July 2019, we retrospectively identified 19 patients who underwent delayed evacuation of an ASDH, with the primary outcome being Glasgow Outcome Score (GOS) at discharge and three-month follow-up. Results Eight patients (42%) were female and 11 patients (58%) were male. The median age was 77 years, with a range from 49 to 93 years. Sixteen patients (84%) were 60 years of age or older. Mechanism of injury was a fall for 10 patients (53%). Median number of days from initial evaluation and surgical evacuation was 11 days with a range from 6 to 31 days. Thirteen patients (68%) had a GOS of 4-5 at three-month follow-up. Six patients (32%) had a GOS 1-3 at three-month follow-up. Two mortalities (11%) recorded in the postoperative period. Conclusion Surgically evacuated ASDH in the elderly population is known to carry a significant mortality and morbidity. With close neuromonitoring, delayed intervention in older patients with an ASDH, initially meeting surgical criteria with a good neurologic exam, is a safe practice. Delayed treatment allows for smaller surgery, decreased operative time, and decreased surgical risk which affects older patients even more than younger patients.

Use of pharyngeal packs in functional endoscopic sinus surgery: A randomized controlled trial.

OBJECTIVE: To determine if pharyngeal packs have an effect on postoperative pain and postoperative nausea and vomiting in functional endoscopic sinus surgery (FESS). STUDY DESIGN: Forty-six patients scheduled for routine endoscopic sinus surgery were recruited into this study. The patients were randomly allocated to have or to not have pharyngeal packing prior to surgery. METHODS: The placement of pharyngeal packs during FESS is controversial. Theoretically, pharyngeal packs may prevent postoperative nausea and vomiting by preventing ingestion of blood during sinus surgery. However, prior studies have not conclusively demonstrated this to be the case in FESS. Pharyngeal packs have been associated with complications including throat pain, aspiration, and death. The objective of this randomized control trial was to determine if pharyngeal packs have an effect on postoperative throat pain, nausea, and vomiting in order to determine their importance during FESS. Patients were blinded to intervention. Postoperatively, throat pain and nausea/vomiting scores were recorded. RESULTS: There was no significant difference in mean throat pain at 4 hours following surgery (P = 0.860). At 24 hours after surgery, patients without pharyngeal packing experienced more pain than those who had a throat pack placed (P = 0.002). There was no significant difference in the level of nausea at 4 hours after surgery (P = 0.315) or at 24 hours after surgery (P = 0.315). CONCLUSION: We recommend against the routine use of placing pharyngeal packs during FESS. LEVEL OF EVIDENCE: 1b. Laryngoscope, 127:2460-2465, 2017.

Total Thyroidectomy Versus Lobectomy for the Treatment of Follicular Thyroid Microcarcinoma.

AIM: To compare the effectiveness of total thyroidectomy versus thyroid lobectomy for the treatment of follicular thyroid microcarcinoma. PATIENTS AND METHODS: Data were extracted from the Surveillance, Epidemiology, and End Results 18 Database. The study cohort included patients diagnosed with follicular thyroid microcarcinoma between 1988 and 2009, treated with either total thyroidectomy or thyroid lobectomy. Propensity-score analysis using inverse probability weighting was used to control for allocation bias. RESULTS: A total of 203 patients were identified. The 5-year overall survival was 98% for patients treated with lobectomy and 99% for those treated with total thyroidectomy; this difference was not statistically significant (p=0.13). Unadjusted analysis and propensity-score analysis revealed no difference in overall survival between the two treatment groups (p=0.15 and p=0.49, respectively). CONCLUSION: Total thyroidectomy does not appear to offer any survival advantage over thyroid lobectomy for patients with follicular thyroid microcarcinoma.

Evaluation of a laryngopharyngeal reflux management protocol.

PURPOSE: To evaluate the effectiveness of a protocol for management of patients with laryngopharyngeal reflux (LPR) in a multi-provider clinic. MATERIALS AND METHODS: This is a retrospective cohort study of 188 patients treated for LPR. A standardized clinical protocol for diagnosis and management was instituted in 2012. Two cohorts were established: those managed according to the protocol, and those who were not. For patients managed with the LPR protocol, diagnosis was made using clinical judgment, guided by the Reflux Symptom Index (RSI) and Reflux Finding Score (RFS). Patients were treated with proton pump inhibitors (PPI) with the goal of weaning therapy after symptom resolution. Response to therapy was rated using a global rating scale with three response levels: no response, partial response, and complete response. The primary outcome measure was complete response to therapy and the secondary outcome measures were any response (complete or partial) and successful wean off PPI therapy. RESULTS: The patients treated with the LPR protocol had higher rates of complete response (p<0.001). There was no statistically significant difference in rates of any response (complete or partial) between the two groups (p=0.08). Patients treated using the LPR protocol were more likely to be successfully weaned off PPI therapy (p=0.006). CONCLUSIONS: The use of an LPR protocol improved treatment effectiveness in our clinic, highlighting the role of clinical protocols in reducing variability in care, thereby improving patient outcomes.

Adenoid cystic carcinoma of the external ear: a population based study.

PURPOSE: To determine the incidence of adenoid cystic carcinoma of the external ear in the United States, and to evaluate the clinical characteristics and survival outcomes associated with the disease. MATERIALS AND METHODS: Data were extracted from the Surveillance, Epidemiology, and End Results (SEER) 18 Database of the National Cancer Institute. The study cohort included patients diagnosed with adenoid cystic carcinoma of the external ear from 1973 to 2012. RESULTS: The incidence of adenoid cystic carcinoma of the external ear was 0.004 per 100,000. The SEER database identified 66 patients meeting the inclusion criteria. Nodal metastasis was noted in 13.1% of patients, while 7.9% had distant metastasis. Distant metastasis was associated with worse overall survival (HR 10.18). However, nodal metastasis had no impact on overall survival (HR 0.15, p = 0.09). Surgery alone was associated with improved overall survival (HR 0.26), compared with combination surgery and radiotherapy, while radiotherapy alone was associated with worse overall survival (HR 20.12). Increasing age (HR 1.12) and black race (HR 6.83) were associated with worse overall survival, while female sex (HR 0.26) was associated with improved overall survival. CONCLUSION: ACC of the external ear is rare. Distant metastasis is a poor prognostic factor. However, nodal metastasis does not appear to impact survival. Advanced age, black race, and male sex are also poor prognostic factors. Surgical resection alone is associated with better survival than combination surgical resection and radiation, or radiotherapy alone.

α1-antitrypsin increases interleukin-1 receptor antagonist production during pancreatic islet graft transplantation.

Although islet transplantation for individuals with type 1 diabetes has been shown to yield superior blood glucose control, it remains inadequate for long-term control. This is partly due to islet injuries and stresses that can lead to beta cell loss. Inhibition of excess IL-1ß activity might minimize islet injuries, thus preserving function. The IL-1 receptor antagonist (IL-1Ra), an endogenous inhibitor of IL-1ß, protects islets from cytokine-induced necrosis and apoptosis. Therefore, an imbalance between IL-1ß and IL-1Ra might influence the courses of allogeneic and autoimmune responses to islets. Our group previously demonstrated that the circulating serine-protease inhibitor human alpha-1-antitrypsin (hAAT), the levels of which increase in circulation during acute-phase immune responses, exhibits anti-inflammatory and islet-protective properties, as well as immunomodulatory activity. In the present study, we sought to determine whether the pancreatic islet allograft-protective activity of hAAT was mediated by IL-1Ra induction. Our results demonstrated that hAAT led to a 2.04-fold increase in IL-1Ra expression in stimulated macrophages and that hAAT-pre-treated islet grafts exhibited a 4.851-fold increase in IL-1Ra transcript levels, which were associated with a moderate inflammatory profile. Unexpectedly, islets that were isolated from IL-1Ra-knockout mice and pre-treated with hAAT before grafting into wild-type mice yielded an increase in intragraft IL-1Ra expression that was presumably derived from infiltrating host cells, albeit in the absence of hAAT treatment of the host. Indeed, hAAT-pre-treated islets generated hAAT-free conditioned medium that could induce IL-1Ra production in cultured macrophages. Finally, we demonstrated that hAAT promoted a distinct phosphorylation and nuclear translocation pattern for p65, a key transcription factor required for IL-1Ra expression.

Central condylar displacement with brain abscess from chronic mandibular osteomyelitis.

In this case report, we describe a unique long-term complication from undiagnosed mandibular osteomyelitis. A 53-year-old female who underwent a dental extraction complicated by chronic postoperative odontogenic infection and cutaneous parotid fistula formation 2 years earlier presented with acute mental status change, gradual unilateral facial nerve palsy (House-Brackmann score V), and nontraumatic dislocation of the condylar head into the middle cranial fossa. The patient's chronic mandibular osteomyelitis led to glenoid fossa erosion, middle cranial fossa penetration, and temporal lobe abscess formation. A combined middle cranial fossa approach through a burr hole placed in the squamous temporal bone near the zygomatic root and intraoral mandibular approach to ipsilateral condylar head was performed to complete partial mandibulectomy, including condylectomy. The patient was treated with 6 weeks of meropenem perioperatively. Four months after the surgery, the patient had complete resolution of skull base osteomyelitis, parotid fistula, and neurologic deficits and full recovery of facial nerve function (House-Brackmann score of I).

Activating transcription factor-2 in survival mechanisms in head and neck carcinoma cells.

BACKGROUND: Activating transcription factor-2 (ATF2) is associated with tumor progression but is not well studied in head and neck squamous cell carcinoma (HNSCC). Its effects in stress and its importance in other survival mechanisms were studied. METHODS: ATF2 expression and nuclear activation were confirmed in HNSCC. After modulation of ATF2, in vitro effects on proliferation and chemosensitivity were studied. Effects on in vivo tumor growth and interleukin 8 (IL-8) expression were determined. Tumor necrosis factor-alpha (TNF-α) treatment was used to further evaluate cytokine production and chemosensitivity. RESULTS: Reductions of ATF2 resulted in significant nuclear p-ATF2 activation, cisplatin resistance, and augmented IL-8 expression without affecting in vivo tumor growth. In this setting, TNF increases p-p38 phosphorylation and chemosensitivity while further enhancing IL-8 production. CONCLUSION: Our data suggest regulatory roles for ATF2 in TNF-related mechanisms of HNSCC. Its perturbation and nuclear activation are associated with significant effects on survival and cytokine production.