Development of hypothyroidism following hemithyroidectomy: A population-based study.

PURPOSE: Hypothyroidism is a known possibility after hemithyroidectomy, with a highly variable incidence in the literature ranging from 8 to 60 %. Incidence of hypothyroidism after hemithyroidectomy was evaluated with a secondary aim to assess incidence in patients with Hashimoto's disease. MATERIALS & METHODS: A retrospective study using the TriNetX global federated research network was performed. We included patients within the last 15 years that were ≥18 years of age and had Current Procedural Terminology codes for hemithyroidectomy. Patients were excluded if they had a total or completion thyroidectomy at any time, a history of thyroid cancer, were preoperatively either on levothyroxine, diagnosed with hypothyroidism, or had a Thyroid Stimulating Hormone ≥ 4 m[IU]/L. We assessed the 3 month incidence of hypothyroidism postoperatively based on the International Classification of Diseases code, TSH ≥ 4 m[IU]/L, or taking levothyroxine after surgery. RESULTS: 6845 patients met the inclusion criteria. Most of the cohort was female (67 %) and white (63 %). The mean age at surgery for this population was 54 ± 14.8 years. During the 15 years of data, we found the 3-month incidence of hypothyroidism following hemithyroidectomy to be 23.58 %. The median time to develop the disease was 41.8 months. A subgroup analysis of those with Hashimoto's revealed a 3-month incidence of 31.1 % of patients developing hypothyroidism after surgery. CONCLUSIONS: This population-based study gives additional insight into the incidence of hypothyroidism after hemithyroidectomy. This will help improve perioperative patient counseling and management.

Impact of intraoperative ischemia time on acute complications of head and neck microvascular free tissue transfer: A systematic review and meta-analysis.

BACKGROUND: To evaluate the relationship between intraoperative ischemia time with acute microvascular free tissue transfer (MFTT) complications in head and neck reconstruction. METHODS: A systematic review using PRISMA guidelines was performed. Inclusion encompassed all available studies published and indexed using PubMed, Medline, and Embase. Meta-analyses were performed using the Cochrane Review Manager tool. Methodological Index for Non-Randomized Studies (MINORS), the Revised Cochrane risk-of-bias tool for randomized trials, and the NIH Study Quality Assessment Tool for non-randomized prospective studies. RESULTS: A total of 430 citations were reviewed. 25 were included in our overall qualitative analysis, and 14 for meta-analysis. When comparing ischemia times for flaps with and without complications, no significant difference was observed (p = 0.98). Additionally, in a separate cohort, no significant effect was realized when correlating ischemia time to overall rates and total complications. CONCLUSION: Ischemia time was not significantly different between those with and without acute flap complications.

Modern multimodality management of patients with caval leiomyosarcoma: New treatment paradigms and potential molecular insights.

BACKGROUND AND OBJECTIVES: Caval leiomyosarcomas (cLMS) are rare soft tissue sarcomas historically associated with high recurrence rates and poor prognosis. While radical resection remains the mainstay of therapy for cLMS, new systemic therapies have presented opportunities for multimodality treatment. We examined the clinical outcomes of patients with cLMS treated with modern, multimodality approaches, and compared their outcomes to those of patients with noncaval retroperitoneal LMS (ncLMS). METHODS: A retrospective, single-institution review identified all patients diagnosed with primary retroperitoneal LMS from 2012 to 2018. Radiographic and pathologic review distinguished patients with cLMS and ncLMS. Standard clinicopathologic variables and response to chemotherapy (when applicable) were analyzed. Primary endpoints were overall (OS) and progression-free survival (PFS). RESULTS: Eleven patients with cLMS were identified. Median tumor size was 7.5 cm (IQR, 5.0-14.3 cm); all patients had Stage II/III disease. Seven patients received neoadjuvant chemotherapy. Nine cLMS patients underwent R0/R1 resection; two did not complete resection. Six patients received adjuvant systemic therapy. Twenty patients with ncLMS were treated during the same period. No statistical intergroup differences were noted in tumor size, pathologic grade, stage, or resection margin status. Patients with ncLMS were less likely to receive neoadjuvant (10% vs. 64%) and adjuvant chemotherapy (30% vs. 55%). Two-year OS (81% vs. 78%; p = NS) and PFS (55% vs. 46%; p = NS) were comparable between cLMS and ncLMS patients. CONCLUSIONS: Multimodality treatment with systemic therapy and aggressive surgical resection may achieve equivalent survival outcomes for patients with cLMS versus similar ncLMS. We recommend that all patients with cLMS be evaluated for multidisciplinary treatment. Genomic and proteomic expression profiling may identify novel or targetable mutations.

Can the Expiratory Disproportion Index Distinguish PVFMD from Subglottic Stenosis in Obese Patients?

OBJECTIVES: Expiratory disproportion index (EDI) is the ratio of forced expiratory volume in 1 second (FEV1) divided by peak expiratory flow rate (PEFR) multiplied by 100. Prominent EDI (>50) values can differentiate subglottic stenosis (SGS) from paradoxical vocal fold movement disorder (PVFMD), but this has not been verified when considering body habitus. We hypothesize that the predictive value of elevated EDI in differentiating SGS from PVFMD will be lower in obese patients than non-obese patients. METHODS: Patients ≥ 18 years old with recorded PFT values, BMI, and airway imaging were reviewed retrospectively from 01/2011 to 10/2018. EDI was recorded for 4 cohorts: non-obese/SGS, non-obese/ PVFMD, obese/SGS, and obese/ PVFMD, to determine the mean EDI and the sensitivity/specificity of an elevated EDI. RESULTS: Mean EDI values were 69.32 and 48.38 in the non-obese SGS and PVFMD groups, respectively (P < .01). They were 58.89 and 47.67 in the obese SGS and PVFMD groups, respectively (P < .05). At a threshold of >50, EDI had a sensitivity of 90.0% and specificity of 51.6% in differentiating between SGS and PVFMD cases in non-obese patients and 51.6% and 63.6% in obese patients. CONCLUSION: Prior literature has established that EDI can distinguish SGS from PVFMD in the general population. Our results show that the mean EDI values were significantly different in both cohorts, but an elevated EDI was not as sensitive at identifying SGS cases in obese patients. This suggests that the EDI should be used with caution in obese patients and should not be relied upon to rule out SGS. LEVEL OF EVIDENCE: 3.

Does the Expiratory Disproportion Index Remain Predictive of Airway Stenosis in Obese Patients?

OBJECTIVES/HYPOTHESIS: The expiratory disproportion index (EDI) is the ratio of forced expiratory volume in 1 second divided by peak expiratory flow rate multiplied by 100. An elevated EDI (>50) can help differentiate upper airway stenosis from other dyspnea etiologies, but this has not been verified when considering body habitus. We hypothesize that the predictive value of elevated EDI in diagnosing airway stenosis will be lower in obese patients as compared to nonobese patients. STUDY DESIGN: Retrospective cohort study. METHODS: Patients >18 years old with recorded pulmonary function test values, body mass index (BMI), and airway imaging were reviewed retrospectively from January 2011 to October 2018. EDI was recorded for four cohorts: nonobese and nonstenotic, obese and nonstenotic, nonobese and stenotic, and obese and stenotic, to determine the mean EDI and the sensitivity and specificity of an elevated EDI. RESULTS: Mean EDI values were 66.53 ± 17.66 and 49.55 ± 2.04 in the nonobese stenotic and nonstenotic groups, respectively (P < .01). They were 58.00 ± 10.79 and 45.02 ± 1.42 in the obese stenotic and nonstenotic groups, respectively (P < .01). At a threshold of >50, EDI had a sensitivity of 83.3% and specificity of 56.2% in differentiating between stenotic and nonstenotic cases in the nonobese cohort and 50.0% and 71.9% in the obese cohort. CONCLUSIONS: As previously established, mean EDI values were significantly different in stenotic and nonstenotic patients in both BMI cohorts. However, at the established threshold of >50, EDI was not as sensitive at identifying stenotic cases in obese patients as in nonobese patients. This suggests that the EDI remains useful in obese patients when elevated but should not be relied upon to rule out stenosis. LEVEL OF EVIDENCE: 4 Laryngoscope, 131:606-609, 2021.

Predictive value of difficult airway identifiers for intubation-related complications in the emergency department.

OBJECTIVES: The Airway Alert banner at our institution alerts physicians to patients with the potential for a difficult intubation. Difficult airway guidelines can reduce intubation complications in the operating room, but little research has been done in the emergency department (ED). We hypothesize that patients meeting criteria for the banner will have a more difficult intubation and increased complications. METHODS: Patients greater than 18 years old who presented to the ED for any complaint and required intubation were reviewed from January 2015 to January 2020 and divided into those meeting criteria for a difficult airway ("criteria cohort") and those who did not ("non-criteria cohort"). Past medical history and details of the intubation were collected. RESULTS: The mean number of attempts for intubation was 1.60 in the criteria cohort and 1.36 in the non-criteria cohort (P > .05). The mean grade of view was 1.73 and 1.39, respectively (P < .05). The average size of endotracheal tube was 7.50 and 7.74 in the criteria and non-criteria cohorts (P < .05). The use of adjuncts was 28.6% and 12.5%, respectively (P < .01). The average number of intubation attempts and complication rate did not differ significantly. CONCLUSIONS: Intubations in patients meeting criteria for the banner are associated with a more difficult view, use of smaller endotracheal tube, and increased use of adjuncts, but not with a significantly higher rate of complications or attempts. Physicians should prepare with additional endotracheal tube sizes, adjuncts, and a plan for secondary strategies in these patients. LEVEL OF EVIDENCE: 2b.

Yield of Imaging to Evaluate Unilateral Vocal Fold Paralysis of Unknown Etiology.

OBJECTIVES/HYPOTHESIS: To identify the incidence and nature of positive findings on imaging studies ordered for evaluation of unilateral vocal fold paralysis (UVFP) of unknown etiology, to analyze these findings based on laterality, and to examine the use of the expanded-field computed tomography (CT) neck protocol in this evaluation. STUDY DESIGN: Retrospective review. METHODS: A total of 145 patients from 2000 to 2018 with UVFP of unknown etiology were studied. Data on imaging studies ordered, laterality of paralysis, and significant positive results were studied. An expanded-field CT neck protocol that included the entire course of the vagus and recurrent laryngeal nerves was instituted during the study period. RESULTS: A total of 20.7% of patients had an etiology for paralysis identified on imaging. Malignancies comprised the majority of findings overall (19/30), whether in the chest (12/18) or the neck (7/12). Etiology was more often found in the chest for left-sided paralysis (15/21) and in the neck for right-sided paralysis (6/9). In 26 patients who underwent both expanded-field CT neck and CT chest, no findings related to the UVFP were seen on CT chest that were not captured by expanded-field CT neck. CONCLUSIONS: This is one of the largest retrospective studies examining the incidence of positive findings on imaging studies for evaluation of UVFP of unknown etiology. Imaging in one of five patients with UVFP of unknown etiology will reveal a causative lesion, most often malignant. Left-sided paralysis tends to localize to the chest, and right-sided paralysis to the neck. Expanded-field CT neck may allow practitioners to forego dedicated CT chest in evaluation of UVFP. LEVEL OF EVIDENCE: 4 Laryngoscope, 131:1840-1844, 2021.

Preserving Mitochondrial Structure and Motility Promotes Recovery of White Matter After Ischemia.

Stroke significantly affects white matter in the brain by impairing axon function, which results in clinical deficits. Axonal mitochondria are highly dynamic and are transported via microtubules in the anterograde or retrograde direction, depending upon axonal energy demands. Recently, we reported that mitochondrial division inhibitor 1 (Mdivi-1) promotes axon function recovery by preventing mitochondrial fission only when applied during ischemia. Application of Mdivi-1 after injury failed to protect axon function. Interestingly, L-NIO, which is a NOS3 inhibitor, confers post-ischemic protection to axon function by attenuating mitochondrial fission and preserving mitochondrial motility via conserving levels of the microtubular adaptor protein Miro-2. We propose that preventing mitochondrial fission protects axon function during injury, but that restoration of mitochondrial motility is more important to promote axon function recovery after injury. Thus, Miro-2 may be a therapeutic molecular target for recovery following a stroke.

Tao Negatively Regulates BMP Signaling During Neuromuscular Junction Development in Drosophila.

The coordinated growth and development of synapses is critical for all aspects of neural circuit function and mutations that disrupt these processes can result in various neurological defects. Several anterograde and retrograde signaling pathways, including the canonical Bone Morphogenic Protein (BMP) pathway, regulate synaptic development in vertebrates and invertebrates. At the Drosophila larval neuromuscular junction (NMJ), the retrograde BMP pathway is a part of the machinery that controls NMJ expansion concurrent with larval growth. We sought to determine whether the conserved Hippo pathway, critical for proportional growth in other tissues, also functions in NMJ development. We found that neuronal loss of the serine-threonine protein kinase Tao, a regulator of the Hippo signaling pathway, results in supernumerary boutons which contain a normal density of active zones. Tao is also required for proper synaptic function, as reduction of Tao results in NMJs with decreased evoked excitatory junctional potentials. Surprisingly, Tao function in NMJ growth is independent of the Hippo pathway. Instead, our experiments suggest that Tao negatively regulates BMP signaling as reduction of Tao leads to an increase in pMad levels in motor neuron nuclei and an increase in BMP target gene expression. Taken together, these results support a role for Tao as a novel inhibitor of BMP signaling in motor neurons during synaptic development and function.

Mitochondrial dynamics and preconditioning in white matter.

Mechanisms of ischemic preconditioning have been extensively studied in gray matter. However, an ischemic episode affects both the gray matter (GM) and white matter (WM) portions of the brain. Inhibition of mitochondrial fission is one of the mechanisms of preconditioning neuronal cell bodies against ischemia. Although axons are anatomical extensions of neuronal cell bodies, injury mechanisms differ between GM and WM. Indeed, axonal dysfunction is responsible for much of the disability associated with clinical deficits observed after stroke; however, the signaling process underlying preconditioning remains unexplored in axons. Using mouse optic nerve, which is a pure isolated WM tract, we show that mitochondria in myelinated axons undergo rapid and profuse fission during oxygen glucose deprivation (OGD) that is mediated by translocation of cytoplasmic Dynamin Related Protein-1 (Drp-1) to mitochondria. OGD-induced mitochondrial fission correlates with reduced mitochondrial motility and loss of axon function. Mitochondrial fragmentation and loss of motility become permanent during the recovery period. Inhibiting mitochondrial fission by administering mitochondrial division inhibitor-1 (Mdivi-1) during OGD preserves mitochondrial shape and motility and promotes axon function recovery. In contrast, preconditioning WM by applying Mdivi-1 only before OGD fails to conserve mitochondrial shape or motility and fails to benefit axon function. Our findings suggest that inhibition of mitochondrial fission during ischemia promotes axon function recovery, but is not sufficient to precondition WM against ischemia. These results raise caution in that approaches to preconditioning neuronal cell bodies may not successfully translate into functional improvement following ischemia.