Fluorescein-Assisted Microsurgical Resection of Vestibular Schwannoma: A Prospective Feasibility Study.

OBJECTIVE: To evaluate the optimal dose and timing of administration of sodium fluorescein (SF) for selective fluorescence of sporadic vestibular schwannoma (VS) during microsurgery with the YELLOW 560-nm microscope filter (YE560) and to characterize the potential benefit of this fluorescence as determined by intraoperative surgeon assessment. STUDY DESIGN: Prospective cohort study. SETTING: Tertiary referral center. PATIENTS: Adult patients undergoing VS microsurgery. INTERVENTIONS: Intraoperative intravenous administration of SF and visualization with the YE560. MAIN OUTCOME MEASURES: Time to differential fluorescence, duration of fluorescence, correlation of fluorescence of VS with electrostimulation and white light microscopy visual assessment, and likelihood of surgeons to use SF with the YE560 in future cases. RESULTS: Novel use of SF and YE560 during microsurgery achieved selective fluorescence of VS with capabilities to differentiate nerve fascicles and tumor approximately 30 minutes after administration. Nuances of SF administration and timing are discussed. Seventy-five percent of surgeons observed an excellent correlation of selective fluorescence with white light microscopy. Representative images and cases are presented. CONCLUSIONS: SF and YE560 may be used in VS microsurgery to visually differentiate VS from surrounding nerves. Potential benefits include enhanced visualization of the tumor-nerve interface for tumor dissection and detection of any residual disease, such as in the fundus after hearing preservation microsurgery.

The role of total parotidectomy in high-grade parotid malignancy: A multisurgeon retrospective review.

PURPOSE: Determine rates of intra-parotid and neck nodal metastasis, identify risk factors for recurrence, and report outcomes in patients with primary high-grade parotid malignancy who undergo total parotidectomy and neck dissection. MATERIALS & METHODS: Retrospective review of patients undergoing total parotidectomy and neck dissection for high-grade parotid malignancy between 2005 and 2015. The presence and number of parotid lymph nodes, superficial and deep, as well as cervical lymph nodes involved with metastatic disease were assessed. Risk factors associated with metastatic spread to the parotid deep lobe were identified and recurrence rates reported. RESULTS: 75 patients with median follow-up time of 47 months. 35 patients (46.7%) had parotid lymph node metastasis. Seven patients (9.3%) had deep lobe nodal metastasis without metastasis to the superficial lobe nodes. Nine patients (12%) had positive intra-parotid nodes without positive cervical nodes. Cervical nodal disease was identified in 49.3% patients (37/75). Local, parotid-bed recurrence rate was 5.3% (4/75). Regional lymph node recurrence rate was also 5.3% (4/75). Rate of distant metastasis was 30.6% (23/75). The overall disease free survival rate for all patients at 2 and 5 years were 71% and 60% respectively. CONCLUSION: Parotid lymph node metastasis occurred at a similar rate to cervical lymph node metastasis (46.7% and 49.3%, respectively). Deep lobe parotid nodal metastasis occurred in nearly a quarter of patients and can occur without superficial parotid nodal metastasis. Rate of recurrence in the parotid bed, which may represent local or regional recurrence, was similar to regional cervical lymph node recurrence. Total parotidectomy and neck dissection should be considered high-grade parotid malignancy regardless of clinical nodal status.

Mucoepidermoid carcinoma of the parotid gland: Twenty-year experience in treatment and outcomes.

BACKGROUND: Parotid gland mucoepidermoid carcinoma (MEC) has published five-year cancer-specific survival (CSS) rates of 77%-97%, with variance related to grade. METHODS: Patients receiving primary surgery for parotid gland MEC from 1995 to 2014 at a tertiary medical center underwent clinical review, histopathologic review, and cytogenetic analysis. Survival outcomes were evaluated. RESULTS: Among 58 patients, T/N/M classification was as follows: T1 in 35 patients, T2 in 14, T4a in 9, N0 in 53, N1 in 2, N2b in 3. Histologic grade was low in 27, intermediate in 17, and high in 12 patients with 98% MAML2 positivity. All patients underwent parotidectomy, and seven patients received adjuvant radiation therapy. CSS was 100% at 5 years and 94.1% at 10 and 15 years. Two patients experienced locoregional recurrence. CONCLUSIONS: Treatment with adequate surgical resection and adjuvant radiation therapy for high-grade or advanced-stage tumors yields excellent survival, independent of clinical stage or pathologic grade.

Evolution in Management Trends of Sporadic Vestibular Schwannoma in the United States Over the Last Half-century.

OBJECTIVE: Limited data currently characterize management trends of sporadic vestibular schwannoma (VS) in the United States over recent decades. Serving as the primary patient support organization in the United States, the Acoustic Neuroma Association (ANA) facilitates amalgamation of data from patients treated from 1970 through January 2019. The primary objective of the current study was to characterize the evolution in the management of sporadic VS among ANA survey respondents treated over the last half-century. STUDY DESIGN/INTERVENTION: Cross-sectional survey. SETTING/PATIENTS: ANA survey respondents diagnosed with sporadic VS. MAIN OUTCOME MEASURES: Trends in rates of microsurgery, radiosurgery, and observation from 1970 to 2019. RESULTS: Among 953 patients with VS responding during the study period, 876 (92%) were included. Subjects reported the following management strategies: 220 observation (25%), 454 microsurgery (52%), and 193 radiosurgery (22%). The rate of microsurgery decreased from 86-88% from 1970 to 2000 to 44% in the last decade. The proportion of VS observed increased from 7% of all tumors in the 1990s, to 14% in the 2000s, to 33% in the 2010s. The rate of radiosurgery has increased to 28% in the last decades compared with 7% in the 1990s. The rate of subtotal resection in tumors > 2 cm increased from 34% in the 2000s to 60% in the 2010s (p = 0.0011). CONCLUSIONS: Overall, these data support a progression toward fewer patients treated with microsurgery in recent decades. Radiosurgery and observation became increasingly more common after the turn of the century, possibly due to better detection of small and asymptomatic tumors and a greater understanding of the natural history of disease.

Upper aerodigestive tract frostbite from inhalation of automotive nitrous oxide.

Nitrous oxide, a cryogenic gas, may be abused as an inhalant for its euphoric properties. If inhaled, nitrous oxide may cause frostbite to the oral cavity and upper aerodigestive tract, with possible airway compromise due to edema. In this article we describe what is, to the best of our knowledge, the first case of intentional inhalation of nitrous oxide from an automotive nitrous oxide canister and discuss the management and mechanism of the patient's injury.

Patient compliance following isolated mandibular fracture repair.

OBJECTIVE: Compliance with postoperative care in the maxillofacial trauma population often is considered poor. This lack of follow-up does not seem to be a function of decreased access to care but rather its anticipated lack of utilization. The goal of this study is to identify what factors are associated with increased compliance in postoperative management of mandible fractures. STUDY DESIGN: Retrospective cohort study. METHODS: Using Current Procedural Terminology codes to identify maxillofacial injuries requiring operative repair, a subset of isolated mandibular fractures was identified. Age, gender, race, insurance type, travel distance, mandible fracture location, surgical approach, and complications were used as variables in univariate regression modeling to examine factors associated with compliance to postoperative care. RESULTS: Between 2010 and 2013, 344 isolated mandible fractures were identified. A total of 83.1% of patients made their first postoperative follow-up visit. Demographic data, fracture location, distance to medical center (odds ratio [OR] = 1, P = 0.75), type of repair, use of drains (OR = 1.27, P = 0.61), or nonabsorbable suture (OR = 1.44, P = 0.32) did not appear to be associated with compliance. No association between complications and postoperative compliance was observed (OR = 2.37, P = 0.17). Trends toward improved compliance were observed when evaluating insurance type and use of temporary fixation hardware. The presence of current tobacco use was found to be negatively associated with patient compliance (OR = 0.33, P < 0.01). CONCLUSION: Postoperative compliance after surgical repair is better than what is currently represented in the literature. It appears that postoperative compliance is dependent on patient-related factors more so than what can be modified by the surgeon. LEVEL OF EVIDENCE: 4. Laryngoscope, 127:2230-2235, 2017.

Novel utilization of serum in tissue decellularization.

Decellularization of native tissues is a promising technique with numerous applications in tissue engineering and regenerative medicine. However, there are various limitations of currently available decellularization methods, such as alteration of extracellular matrix mechanics and restricted use on certain tissues. This study was conducted to explore the effect of serum on the decellularization of various types of tissues. Fetal bovine serum-containing cell culture medium endothelial growth media-2 removed DNA but not cellular beta-actin from human umbilical artery after detergent treatment, without compromising the tissue mechanical strength assessed by burst pressure. In addition, the effect of serum-containing endothelial growth media-2 on DNA removal was replicated in other types of tissues such as tissue-engineered vessels and myocardium. Other types of serum, including human serum, were also shown to remove DNA from detergent-pretreated tissues. In conclusion, we describe a novel utilization of serum that may have broad applications in tissue decellularization.

Development of decellularized human umbilical arteries as small-diameter vascular grafts.

OBJECTIVE: Developing a tissue-engineered small-diameter (<6mm) vascular graft for reconstructive surgery has remained a challenge for the past several decades. This study was conducted to develop a decellularized umbilical artery and to evaluate its composition, endothelial cell compatibility, mechanical properties, and in vivo stability for potential use as a small-diameter vascular graft. METHODS AND RESULTS: Human umbilical arteries were isolated and decellularized by incubation in CHAPS and sodium dodecyl sulfate buffers followed by incubation in endothelial growth media-2. Decellularized umbilical arteries were completely devoid of cellular and nuclear material while retaining the integrity of extracellular collagenous matrix. The mechanical strength of the decellularized umbilical artery as assessed by its burst pressure in vitro showed no significant change from its native form. Decellularized umbilical arteries supported endothelial adherence as indicated by the re-endotheliazation with a monolayer of human umbilical vein endothelial cells. Furthermore, decellularized vessels that were implanted into nude rats as abdominal aorta interposition grafts remained mechanically intact and patent for up to 8 weeks. CONCLUSION: Decellularized human umbilical arteries preserved the extracellular matrix, supported endothelialization, and retained function in vivo for up to 8 weeks. These properties suggest the potential use of decellularized umbilical arteries as small-diameter vascular grafts.