Lateral border and scapular tip free flaps: Old school versus new school.

Free tissue transfer from the subscapular system provides a wide array of options for both soft tissue and bony reconstruction. When bone stock is required for head and neck reconstruction, both the lateral scapular border free flap (LSBFF), supplied by the circumflex scapular artery, and the scapular tip free flap (STFF), supplied by the angular artery, are excellent options. Issues with positioning had previously prevented the widespread use of these bony subscapular system flaps. However, through the use of a Spider Limb Positioner, current clinical practice patterns allow for two team approaches in both of these free flaps. The following pictorial essay compares and contrasts the specific positioning and harvesting technique used for both the LSBFF and STFF, while discussing the clinical advantages and drawbacks of each. Both the lateral border scapula and scapular tip free flaps provide excellent bone stock for head and neck reconstruction. By positioning with currently available technology, both of these free flaps can be harvested through a two team approach.

Revisiting pedicled latissimus dorsi flaps in head and neck reconstruction: contrasting shoulder morbidities across mysofascial flaps.

Free tissue transfer has become the gold standard for reconstruction within the head and neck. However, there are still many instances where pedicled locoregional flaps are the optimal reconstructive option. When myofascial tissue is needed, several options have been described throughout the literature. Various trapezius flaps have been used, although these have variable vascular anatomy and significant donor site morbidity. The pectoralis major myofascial flap has become a mainstay in head and neck reconstruction for its ease of harvest and reliability but suffers from similar issues with donor site morbidity. The pedicled latissimus dorsi flap (PLDF) is another reliable option that has been used for multiple different ablative sites within the head and neck. The thin, pliable structure of the latissimus dorsi makes it a viable option for many defects, and recent reports also support its feasibility for use in an interdisciplinary two-team approach. Furthermore, the donor site morbidity of the PLDF is minimal compared to other similar myofascial options. In this article, we describe the surgical considerations and operative techniques for PLDF transfer along with a review of its associated donor site morbidity.

Primary Clear Cell Adenocarcinoma of the Head and Neck: A Population-Based Analysis.

OBJECTIVE: To characterize the epidemiology and clinicopathologic determinants of survival following the diagnosis of clear cell adenocarcinoma in the head and neck region. STUDY DESIGN: Retrospective cohort study. SETTING: The Surveillance, Epidemiology, and End Results registry (1994 to 2014). SUBJECTS AND METHODS: A total of 173 cases were identified. Study variables included age, sex, race, tumor subsite, tumor stage, tumor grade, surgical excision, and regional and distant metastases. Survival measures included overall survival (OS) and disease-specific survival (DSS). RESULTS: Median age at diagnosis was 63 years, 48% were female, and 80.2% were white. Fourteen percent of patients presented with regional lymph node metastases, while 3.3% of patients presented with distant metastases. Most of the tumors presented in the oral cavity, salivary glands, and pharynx. Kaplan-Meier analysis demonstrated OS and DSS of 77.2% and 83.7% at 5 years, respectively. Median OS after diagnosis was 153 months. Bivariate analysis showed that surgical excision was associated with 5-fold increased OS and DSS, whereas advanced age, high tumor grade, advanced stage, larger tumor size, nodal disease, and distant metastases were all significant predictors of decreased OS and DSS. CONCLUSIONS: Clear cell adenocarcinoma is a rare neoplasm that typically affects white individuals in their early 60s, with a generally favorable prognosis. It most commonly arises in the oral cavity, major salivary glands, and pharynx. Surgical excision is associated with 5-fold survival benefit, whereas advanced age, high tumor grade, advanced stage, nodal disease, and distant metastases are independently associated with worse OS and DSS.

Understanding nationwide readmissions after parotidectomy.

OBJECTIVES: To evaluate the incidence, causes, risk factors, and costs associated with 30-day readmissions in parotidectomy patients utilizing the Nationwide Readmissions Database (NRD). STUDY DESIGN: Retrospective cohort study. METHODS: We examined the NRD for patients who underwent parotidectomy between 2010 and 2014. Rates, causes, and costs of 30-day readmissions were determined. Multivariate logistic regression was used to identify risk factors for readmission. RESULTS: Among 15,102 included patients, 594 (3.9%) were readmitted within 30 days. The average cost per readmission was $12,502. Infectious (22.7%) and wound (11.2%) complications were the two most common causes of readmission. After controlling for other covariates, significant predictors of readmission included advanced comorbidity (odds ratio [OR], 1.61; 95% confidence interval [CI], 1.09-2.37), a malignant parotid tumor (OR, 2.37; 95% CI, 1.63-3.43), length of stay ≥2 days (OR, 1.54; 95% CI, 1.09-2.18), and nonroutine discharge destinations (home with care [OR, 1.88; 95% CI, 1.27-2.78] and nursing facility [OR, 2.69; 95% CI, 1.55-4.67]). CONCLUSION: In this nationwide database analysis, we found that nearly 4% of all patients undergoing parotidectomy are readmitted within 30 days. Readmissions are commonly due to infections and wound complications. Quality improvement proposals targeting avoidable readmissions should focus on early recognition and prevention of infection and wound complications. Risk factors contributing to readmission include advanced comorbidity, malignant parotid tumor, prolonged index hospitalization, and nonroutine discharge destinations. LEVEL OF EVIDENCE: NA Laryngoscope, 130:1212-1217, 2020.

A Population-Based Analysis of Nodal Metastases in Esthesioneuroblastomas of the Sinonasal Tract.

OBJECTIVE: Esthesioneuroblastoma is an uncommon malignancy of the sinonasal tract arising from the olfactory epithelium. Surgical management of the primary site, often via an endoscopic approach, with or without adjuvant radiation, is often curative. There is growing but ultimately limited data regarding management of the neck and the risk of nodal metastases. In this study, we examine the incidence and patterns of esthesioneuroblastoma-related cervical nodal metastases using the Surveillance, Epidemiology, and End Results (SEER) database. METHODS: The SEER registry was queried for all patients with esthesioneuroblastomas diagnosed between 1973 and 2012. Patient data was then analyzed with respect to age, sex, race, modified Kadish stage, grade, survival functions, and nodal disease including specific nodal basins. RESULTS: Three hundred and eighty-one cases of esthesioneuroblastoma with information on nodal metastases were identified. The overall cervical nodal metastasis rate was 8.7%. Level II metastases were most common (6.6%). A total of 4.5% of cases presented with multiple positive nodal basins. Male sex (P = 0.009) and higher tumor grade (P = 0.009) correlated with the presence of level II metastases. There was no association of primary tumor site to the presence of nodal metastases (P > 0.05). The presence of nodal disease significantly predicted poorer overall (P = 0.001) and disease-specific survival (P = 0.017). CONCLUSION: The incidence of nodal metastases in esthesioneuroblastoma at diagnosis is rare, and elective management of the neck remains controversial. Primary tumor site does not appear to predict metastases at specific nodal basins. Higher tumor grade may be a harbinger of eventual nodal metastases. LEVEL OF EVIDENCE: NA Laryngoscope, 129:1025-1029, 2019.

Co-culture of adipose-derived stem cells and chondrocytes on three-dimensionally printed bioscaffolds for craniofacial cartilage engineering.

OBJECTIVES/HYPOTHESIS: Reconstruction of craniofacial cartilagenous defects are among the most challenging surgical procedures in facial plastic surgery. Bioengineered craniofacial cartilage holds immense potential to surpass current reconstructive options, but limitations to clinical translation exist. We endeavored to determine the viability of utilizing adipose-derived stem cell-chondrocyte co-culture and three-dimensional (3D) printing to produce 3D bioscaffolds for cartilage tissue engineering. We describe a feasibility study revealing a novel approach for cartilage tissue engineering with in vitro and in vivo animal data. METHODS: Porcine adipose-derived stem cells and chondrocytes were isolated and co-seeded at 1:1, 2:1, 5:1, 10:1, and 0:1 experimental ratios in a hyaluronic acid/collagen hydrogel in the pores of 3D-printed polycaprolactone scaffolds to form 3D bioscaffolds for cartilage tissue engineering. Bioscaffolds were cultured in vitro without growth factors for 4 weeks and then implanted into the subcutaneous tissue of athymic rats for an additional 4 weeks before sacrifice. Bioscaffolds were subjected to histologic, immunohistochemical, and biochemical analysis. RESULTS: Successful production of cartilage was achieved using a co-culture model of adipose-derived stem cells and chondrocytes without the use of exogenous growth factors. Histology demonstrated cartilage growth for all experimental ratios at the post-in vivo time point confirmed with type II collagen immunohistochemistry. There was no difference in sulfated-glycosaminoglycan production between experimental groups. CONCLUSION: Tissue-engineered cartilage was successfully produced on 3D-printed bioresorbable scaffolds using an adipose-derived stem cell and chondrocyte co-culture technique. This potentiates co-culture as a solution for several key barriers to a clinically translatable cartilage tissue engineering process. LEVEL OF EVIDENCE: NA. Laryngoscope, 128:E251-E257, 2018.

Biomechanical evaluation of human and porcine auricular cartilage.

OBJECTIVES/HYPOTHESIS: The mechanical properties of normal auricular cartilage provide a benchmark against which to characterize changes in auricular structure/function due to genetic defects creating phenotypic abnormalities in collagen subtypes. Such properties also provide inputs/targets for auricular reconstruction scaffold design. Several studies report the biomechanical properties for septal, costal, and articular cartilage. However, analogous data for auricular cartilage are lacking. Therefore, our aim in this study was to characterize both whole-ear and auricular cartilage mechanics by mechanically testing specimens and fitting the results to nonlinear constitutive models. STUDY DESIGN: Mechanical testing of whole ears and auricular cartilage punch biopsies. METHODS: Whole human cadaveric ear and auricular cartilage punch biopsies from both porcine and human cartilage were subjected to whole-ear helix-down compression and quasistatic unconfined compression tests. Common hyperelastic constitutive laws (widely used to characterize soft tissue mechanics) were evaluated for their ability to represent the stress-strain behavior of auricular cartilage. RESULTS: Load displacement curves for whole ear testing exhibited compliant linear behavior until after significant displacement where nonlinear stiffening occurred. All five commonly used two-term hyperelastic soft tissue constitutive models successfully fit both human and porcine nonlinear elastic behavior (mean R(2) fit >0.95). CONCLUSIONS: Auricular cartilage exhibits nonlinear strain-stiffening elastic behavior that is similar to other soft tissues in the body. The whole ear exhibits compliant behavior with strain stiffening at high displacement. The constants from the hyperelastic model fits provide quantitative baselines for both human and porcine (a commonly used animal model for auricular tissue engineering) auricular mechanics. LEVEL OF EVIDENCE: NA

Local presynaptic activity gates homeostatic changes in presynaptic function driven by dendritic BDNF synthesis.

Homeostatic synaptic plasticity is important for maintaining stability of neuronal function, but heterogeneous expression mechanisms suggest that distinct facets of neuronal activity may shape the manner in which compensatory synaptic changes are implemented. Here, we demonstrate that local presynaptic activity gates a retrograde form of homeostatic plasticity induced by blockade of AMPA receptors (AMPARs) in cultured hippocampal neurons. We show that AMPAR blockade produces rapid (<3 hr) protein synthesis-dependent increases in both presynaptic and postsynaptic function and that the induction of presynaptic, but not postsynaptic, changes requires coincident local activity in presynaptic terminals. This "state-dependent" modulation of presynaptic function requires postsynaptic release of brain-derived neurotrophic factor (BDNF) as a retrograde messenger, which is locally synthesized in dendrites in response to AMPAR blockade. Taken together, our results reveal a local crosstalk between active presynaptic terminals and postsynaptic signaling that dictates the manner by which homeostatic plasticity is implemented at synapses.