Bipedicled submental musculofascial "hammock" flap for salvage laryngectomy closure reinforcement.

BACKGROUND: The aim of the study was to describe a novel technique for reinforcement of salvage laryngectomy closure using a bipedicled musculofascial submental flap. METHODS: A retrospective cohort study design identified patients who underwent salvage laryngectomy reinforcement with a bipedicled submental hammock flap between January 2008 and December 2016 were compared to salvage laryngectomy patients treated with primary closure of the neopharynx during the same time period. Pharyngocutaneous fistula rates were compared between groups. RESULTS: Pharyngocutaneous fistula rate in the submental hammock group (2/31, 6.5%) was significantly lower compared to the primary closure group (14/45, 31%, P < .05). CONCLUSION: The bipedicled musculofascial submental hammock flap is a viable method for reinforcement of salvage laryngectomy defects. It has a favorable pharyngocutaneous fistula rate compared to primary closure alone and has unique advantages over conventional methods of reinforcement.

Cervicofacial necrotising fasciitis by clindamycin-resistant and methicillin-resistant Staphylococcus aureus (MRSA) in a young healthy man.

An otherwise healthy 24-year-old man presented with 1 week of fever, facial pain and swelling. He initially sought care at an outside hospital, where he was diagnosed with folliculitis and sent home with oral antibiotics. On arrival at our institution, CT neck was ordered, which demonstrated diffuse submental phlegmon, prompting incision and drainage. After initial improvement, the patient experienced high fevers and increased swelling just 12 hours later. The decision was made to take the patient for operative exploration, and wide debridement was performed due to suspicion for necrotising fasciitis intraoperatively that was ultimately confirmed on final pathology. Final speciation of intraoperative culture demonstrated a clindamycin-resistant and methicillin-resistant strain of Staphylococcus aureus The patient was managed with intravenous antibiotics, additional debridement and careful wound care. Delayed partial closure of wound was eventually performed once patient showed marked and persistent clinical improvement. The patient was discharged on hospital day 12 with close follow-up.

Reconstruction of the segmental mandibular defect: current state of the art.

PURPOSE OF REVIEW: This article reviews literature pertaining to advances in the reconstruction of segmental mandibular defects in the context of an established standard of care, microvascular transfer of free osteocutaneous flaps. RECENT FINDINGS: Most literature reiterates established reconstructive techniques. Exceptions include the use of computer-assisted modeling to preoperatively design the excision of both the mandible and fibula segments and to produce a template for contouring the neomandible, the design of new flaps, distraction osteogenesis and techniques for dealing with osteonecrosis. SUMMARY: The microvascular transfer of free osteocutaneous flaps remains the standard of care, with the fibula flap the clear favorite. Review of the evolution of this flap for segmental mandibular reconstruction provides the bulk of the literature. Improvement on this standard of practice continues to be elusive, in large part because of the effects of associated radiation. Tissue engineering holds promise but no current practical application is available.

EGFR kinase promotes acquisition of stem cell-like properties: a potential therapeutic target in head and neck squamous cell carcinoma stem cells.

Members of the EGFR/ErbB family of tyrosine kinases are found to be highly expressed and deregulated in many cancers, including head and neck squamous cell carcinoma (HNSCC). The ErbB family, including EGFR, has been demonstrated to play key roles in metastasis, tumorigenesis, cell proliferation, and drug resistance. Recently, these characteristics have been linked to a small subpopulation of cells classified as cancer stem cells (CSCs) which are believed to be responsible for tumor initiation and maintenance. In this study, we investigated the possible role of EGFR as a regulator of "stemness" in HNSCC cells. Activation of EGFR by the addition of EGF ligand or ectopic expression of EGFR in two established HNSCC cell lines (UMSCC-22B and HN-1) resulted in the induction of CD44, BMI-1, Oct-4, NANOG, CXCR4, and SDF-1. Activation of EGFR also resulted in increased tumorsphere formation, a characteristic ability of cancer stem cells. Conversely, treatment with the EGFR kinase inhibitor, Gefinitib (Iressa), resulted in decreased expression of the aforementioned genes, and loss of tumorsphere-forming ability. Similar trends were observed in a 99.9% CD44 positive stem cell culture derived from a fresh HNSCC tumor, confirming our findings for the cell lines. Additionally, we found that these putative cancer stem cells, when treated with Gefitinib, possessed a lower capacity to invade and became more sensitive to cisplatin-induced death in vitro. These results suggest that EGFR plays critical roles in the survival, maintenance, and function of cancer stem cells. Drugs that target EGFR, perhaps administered in combination with conventional chemotherapy, might be an effective treatment for HNSCC.

Merlin knockdown in human Schwann cells: clues to vestibular schwannoma tumorigenesis.

HYPOTHESIS: To investigate the early events in molecular progression toward schwannoma tumorigenesis, we developed an in vitro model of human Schwann cell tumorigenesis by merlin knockdown. BACKGROUND: Neurofibromatosis 2 (NF2)-related and sporadic vestibular schwannoma (VS) exhibit loss of functional merlin (schwannomin). After loss of merlin expression in the Schwann cell, the initial steps toward VS tumorigenesis are unknown. Merlin, a putative tumor suppressor protein, interacts with many cellular proteins, regulating their function. Among these are receptor tyrosine kinases, including the epidermal growth factor receptor family B (ErbB) family receptors epidermal growth factor receptor and ErbB2. Functional merlin interacts with and internalizes these growth factor receptors, silencing their proliferation and survival signaling. Deregulation of CD44, the cell adhesion/signaling molecule and cancer stem cell marker, has also been implicated in VS tumorigenesis. METHODS: Merlin knockdown was performed using small interfering RNA transfection into human Schwann cell primary cultures. Knockdown was confirmed by real-time quantitative PCR, immunofluorescence, and Western analysis. Expression profiles of ErbB, merlin, and the stem cell markers nestin and CD44 were examined in knockdowns. Proliferation rate was assessed with bromodeoxyuridine incorporation, and radiation sensitivity was assessed using the Annexin assay in knockdowns versus controls. RESULTS: Merlin knockdowns demonstrated increased proliferation rate, upregulation of epidermal growth factor receptor, ErbB2, and ErbB3, CD44, and nestin. Short-term merlin depletion had no effect on gamma irradiation sensitivity compared with controls. CONCLUSION: Merlin depletion results in deregulation of ErbB receptor signaling, promotes a dedifferentiated state, and increases Schwann cell proliferation, suggesting critical steps toward schwannoma tumorigenesis.

Vestibular schwannoma quantitative polymerase chain reaction expression of estrogen and progesterone receptors.

OBJECTIVES/HYPOTHESIS: Determine the role of estrogen receptor (ER) and progesterone receptor (PR) expression in sporadic and neurofibromatosis 2 (NF2)-related vestibular schwannomas (VS). Growth and proliferation signaling in human VS tumorigenesis may play a key role in molecular therapeutic targeting. VS carry mutations of the NF2 gene encoding the tumor suppressor, merlin, which interacts with ErbB2 in Schwann cells, implicating ErbB receptors in VS tumorigenesis. ErbB receptor family members are overexpressed or constitutively activated in many human tumors, and are effective therapeutic targets in some human cancers. VS occur more frequently in women and are larger, more vascular, and demonstrate increased growth rates during pregnancy. ER and PR may play a role in ErbB pathway activation and VS progression. STUDY DESIGN: Quantitative real-time polymerase chain reaction (qRT-PCR) for ER and PR messenger RNA was performed using greater auricular and vestibular nerve controls (n = 8), sporadic VS (n = 23), and NF2-related VS (n = 16) tissues. METHODS: The qRT-PCR data were normalized with standardization to a single constitutively expressed control gene, human cyclophylin. RESULTS: Reverse transcription of messenger RNA from control and tumor specimens followed by RT Q-PCR demonstrated differences in ER and PR gene expression between sporadic and NF2-related VS. CONCLUSIONS: ER and PR expression in VS might have implications for development of a VS-specific drug delivery system using antihormone and ErbB pathway small molecule inhibitors, due to crosstalk between these receptors. These signals may be critical for re-establishing ErbB-mediated cell density dependent growth inhibition.

Two temporal bone computed tomography measurements increase recognition of malformations and predict sensorineural hearing loss.

OBJECTIVES/HYPOTHESIS: The objectives of this prospective study were to assess the reproducibility of the measurements of the cochlea and lateral semicircular canal (LSCC) and to determine if abnormal measurements predict sensorineural hearing loss (SNHL). METHODS: Two readers independently measured the cochlear height on coronal section and the LSCC bony island width on axial section on 109 temporal bone computed tomography scans; audiologic data on these patients were collected independently from medical records. Inter- and intrareader variability was evaluated using intraclass correlation coefficients (ICCs) based on a random-effects model. The positive and negative predictive values of abnormal measurement for hearing loss were determined. RESULTS: There was excellent inter- and intraobserver agreement for both measurements (ICC >80%). The average cochlear height was 5.1 mm (normal range, 4.4-5.9 mm) and average LSCC bony island width was 3.7 mm (normal range, 2.6-4.8 mm). Review of the original radiology reports demonstrated that both cochlear hypoplasia and LSSC dysplasia were overlooked in >50% of patients with both abnormal measurements and SNHL. Cochlear hypoplasia (< 4.4 mm) had a positive predictive value of 100% for SNHL, whereas cochlear hyperplasia and bony island dysplasia were less predictive. CONCLUSION: The measurements of coronal cochlear height and axial LSCC bony width have excellent reproducibility and identify bony labyrinth abnormalities missed by visual inspection alone. In addition, cochlear hypoplasia is highly predictive of SNHL. To reliably identify inner ear malformations, measurement of the cochlear height and LSCC bony island width, in addition to the vestibular aqueduct, should be routinely performed on all temporal bone studies.