Single-cell analysis reveals cellular and molecular factors counteracting HPV-positive oropharyngeal cancer immunotherapy outcomes.

BACKGROUND: Oropharyngeal squamous cell carcinoma (OPSCC) induced by human papillomavirus (HPV-positive) is associated with better clinical outcomes than HPV-negative OPSCC. However, the clinical benefits of immunotherapy in patients with HPV-positive OPSCC remain unclear. METHODS: To identify the cellular and molecular factors that limited the benefits associated with HPV in OPSCC immunotherapy, we performed single-cell RNA (n=20) and T-cell receptor sequencing (n=10) analyses of tonsil or base of tongue tumor biopsies prior to immunotherapy. Primary findings from our single-cell analysis were confirmed through immunofluorescence experiments, and secondary validation analysis were performed via publicly available transcriptomics data sets. RESULTS: We found significantly higher transcriptional diversity of malignant cells among non-responders to immunotherapy, regardless of HPV infection status. We also observed a significantly larger proportion of CD4+ follicular helper T cells (Tfh) in HPV-positive tumors, potentially due to enhanced Tfh differentiation. Most importantly, CD8+ resident memory T cells (Trm) with elevated KLRB1 (encoding CD161) expression showed an association with dampened antitumor activity in patients with HPV-positive OPSCC, which may explain their heterogeneous clinical outcomes. Notably, all HPV-positive patients, whose Trm presented elevated KLRB1 levels, showed low expression of CLEC2D (encoding the CD161 ligand) in B cells, which may reduce tertiary lymphoid structure activity. Immunofluorescence of HPV-positive tumors treated with immune checkpoint blockade showed an inverse correlation between the density of CD161+ Trm and changes in tumor size. CONCLUSIONS: We found that CD161+ Trm counteracts clinical benefits associated with HPV in OPSCC immunotherapy. This suggests that targeted inhibition of CD161 in Trm could enhance the efficacy of immunotherapy in HPV-positive oropharyngeal cancers. TRIAL REGISTRATION NUMBER: NCT03737968.

A Phase II Open-Label Randomized Clinical Trial of Preoperative Durvalumab or Durvalumab plus Tremelimumab in Resectable Head and Neck Squamous Cell Carcinoma.

PURPOSE: Clinical implications of neoadjuvant immunotherapy in patients with locally advanced but resectable head and neck squamous cell carcinoma (HNSCC) remain largely unexplored. PATIENTS AND METHODS: Patients with resectable HNSCC were randomized to receive a single dose of preoperative durvalumab (D) with or without tremelimumab (T) before resection, followed by postoperative (chemo)radiotherapy based on multidisciplinary discretion and 1-year D treatment. Artificial intelligence (AI)-powered spatial distribution analysis of tumor-infiltrating lymphocytes and high-dimensional profiling of circulating immune cells tracked dynamic intratumoral and systemic immune responses. RESULTS: Of the 48 patients enrolled (D, 24 patients; D+T, 24 patients), 45 underwent surgical resection per protocol (D, 21 patients; D+T, 24 patients). D±T had a favorable safety profile and did not delay surgery. Distant recurrence-free survival (DRFS) was significantly better in patients treated with D+T than in those treated with D monotherapy. AI-powered whole-slide image analysis demonstrated that D+T significantly reshaped the tumor microenvironment toward immune-inflamed phenotypes, in contrast with the D monotherapy or cytotoxic chemotherapy. High-dimensional profiling of circulating immune cells revealed a significant expansion of T-cell subsets characterized by proliferation and activation in response to D+T therapy, which was rare following D monotherapy. Importantly, expansion of specific clusters in CD8+ T cells and non-regulatory CD4+ T cells with activation and exhaustion programs was associated with prolonged DRFS in patients treated with D+T. CONCLUSIONS: Preoperative D±T is feasible and may benefit patients with resectable HNSCC. Distinct changes in the tumor microenvironment and circulating immune cells were induced by each treatment regimen, warranting further investigation.

Guideline for the Surgical Management of Locally Invasive Differentiated Thyroid Cancer From the Korean Society of Head and Neck Surgery.

The aim of this study was to develop evidence-based recommendations for determining the surgical extent in patients with locally invasive differentiated thyroid cancer (DTC). Locally invasive DTC with gross extrathyroidal extension invading surrounding anatomical structures may lead to several functional deficits and poor oncological outcomes. At present, the optimal extent of surgery in locally invasive DTC remains a matter of debate, and there are no adequate guidelines. On October 8, 2021, four experts searched the PubMed, Embase, and Cochrane Library databases; the identified papers were reviewed by 39 experts in thyroid and head and neck surgery. The Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach was used to assess the quality of evidence, and to develop and report recommendations. The strength of a recommendation reflects the confidence of a guideline panel that the desirable effects of an intervention outweigh any undesirable effects, across all patients for whom the recommendation is applicable. After completing the draft guidelines, Delphi questionnaires were completed by members of the Korean Society of Head and Neck Surgery. Twenty-seven evidence-based recommendations were made for several factors, including the preoperative workup; surgical extent of thyroidectomy; surgery for cancer invading the strap muscles, recurrent laryngeal nerve, laryngeal framework, trachea, or esophagus; and surgery for patients with central and lateral cervical lymph node involvement. Evidence-based guidelines were devised to help clinicians make safer and more efficient clinical decisions for the optimal surgical treatment of patients with locally invasive DTC.

Effect of human acellular dermal matrix (Megaderm™) on infra-auricular depressed deformities, Frey's syndrome, and first bite syndrome following parotidectomy: a multi-center prospective study.

BACKGROUND: Parotidectomy is the primary treatment for parotid gland tumors. However, complications may include a prominent facial scar or infra-auricular depressed deformity, Frey's syndrome, first bite syndrome, or other facial pain, numbness, and paralysis. Acellular dermal matrix (ADM) has been widely used to prevent these complications in parotid surgery, but there have been no prospective, multi-center trials documenting its efficacy. This study evaluates the effectiveness of ADM implantation in preventing infra-auricular depressed deformity, Frey's syndrome and first bite syndrome after parotidectomy. METHODS: We analyzed 51 cases of standard parotidectomy and 58 cases of parotidectomy with implantation of Megaderm™ ADM through prospective multicenter trial. Acute complications including infection, seroma, hematoma, skin necrosis, and acute parotid area pain were evaluated 1 week postoperatively. Clinician grading of Frey's syndrome and blinded clinician evaluation of infra-auricular depressed deformities were conducted at 3, 6, and 12 months. Patients evaluated subjective satisfaction with neck appearance, Frey's syndrome quality, and acute parotid area pain at 3, 6, and 12 months. RESULTS: There was a higher incidence of seroma in the Megaderm™ group than in the control group at week 1. The incidence and total clinician-evaluated Frey's syndrome scores were significantly lower in the Megaderm™ group than in the control group at 3, 6, and 12 months. Both the objective and subjective evaluations of the facial contour showed a better outcome in the Megaderm™ group compared to the control group at 3, 6, and 12 months. There were no significant differences between the groups in the patient-reported Frey's syndrome quality scores at 3, 6, and 12 months, but the Megaderm™ group reported significantly less acute pain than the control group. CONCLUSIONS: ADM implantation can effectively reduce the occurrence of Frey's syndrome, infra-auricular depressed deformity, and first bite syndrome after parotidectomy. ADM may be especially advantageous in complex parotidectomy cases when significant complications are expected.

Recent Treatment Patterns of Oropharyngeal Cancer in Korea Based on the Expert Questionnaire Survey of the Korean Society for Head and Neck Oncology (KSHNO).

PURPOSE: The incidence of human papillomavirus (HPV)-related oropharyngeal cancer (OPC) has increased, and staging and optimal therapeutic approaches are challenging. A questionnaire survey was conducted to investigate the controversial treatment policy of stage T2 OPC according to the N category and determine the opinions of multidisciplinary experts in Korea. MATERIALS AND METHODS: Five OPC scenarios were developed by the Subcommittee on Oropharyngeal Treatment Guidelines of the Korean Society for Head and Neck Oncology and distributed to experts of multidisciplinary treatment hospitals. RESULTS: Sixty-five experts from 45 institutions responded. For the HPV-positive T2N0M0 scenario, 67.7% of respondents selected surgery followed by definitive concurrent chemoradiotherapy (CCRT) or radiotherapy alone. For the T2N1M0 HPV-positive scenario, there was a notable difference in the selection of primary treatment by expert specialty; 53.9% of respondents selected surgery and 39.8% selected definitive CCRT as the primary treatment. For the T2N3M0 advanced HPV-positive scenario, 50.0% of respondents selected CCRT and 33.3% considered induction chemotherapy (IC) as the primary treatment. CCRT and IC were significantly more frequently selected for the HPV-related OPC cases (p=0.010). The interdepartmental variability showed that the head and neck surgeons and medical oncologists favored surgery, whereas the radiation oncologists preferably selected definitive CCRT (p < 0.001). CONCLUSION: In this study, surgery was preferred for lymph node-negative OPC, and as lymph node metastasis progressed, CCRT tended to be preferred, and IC was administered. Clinical practice patterns by stage and HPV status showed differences according to expert specialty. Multidisciplinary consensus guidelines will be essential in the future.

Effects of Intratympanic Injection of Isosorbide on the Vestibular Function of Animal Models of Endolymphatic Hydrops.

OBJECTIVES: The aims of this study were to investigate the effects of intratympanic injections of isosorbide on vestibular function in animal models of endolymphatic hydrops and to find a new treatment option for the acute onset of vertigo in Ménière disease (MD). METHODS: Seventy male guinea pigs received intratympanic injection of isosorbide (IT-ISB). The animals were divided into three study groups: control, a chronic hydrops model, and an acute hydrops model. Intracochlear drug concentrations were measured using high-performance liquid chromatography. Vestibular function was analyzed using an animal rotator test with bidirectional sinusoidal harmonic acceleration before and after IT-ISB administration. Histological changes were also investigated. RESULTS: ISB successfully permeated the perilymph through the round window membrane (RWM) at all three concentrations (25%, 50%, and 100%). In the chronic hydrops model, while IT-ISB histologically induced a reduction of endolymphatic hydrops, vestibular function was unchanged. In the acute hydrops model, no endolymphatic hydrops was histologically observed, and vestibular symmetry was also preserved after IT-ISB. CONCLUSION: ISB passed through the RWM into the perilymphatic space even at lower concentrations. IT-ISB histologically reduced hydrops in the chronic model and preserved symmetrical vestibular function in the acute model. IT-ISB could be a treatment candidate for acute attacks of vertigo in MD.

Safety of esophagogastroduodenoscopy-guided forceps biopsy and the feasibility of esophagogastroduodenoscopy for evaluation of hypopharyngeal cancer.

BACKGROUND: There is currently no established standard tissue sampling method for hypopharyngeal cancer. The present study aimed to evaluate the feasibility of esophagogastroduodenoscopy (EGD) for the pretreatment evaluation of hypopharyngeal cancer and the safety of EGD-guided forceps biopsy. METHODS: We reviewed nine patients with hypopharyngeal cancer who underwent EGD for the evaluation of tumor extent and tissue biopsy from March 2014 to March 2017 at International St. Mary's Hospital. One experienced endoscopist performed all the EGD procedures in the presence of a head and neck surgeon. The procedure included determining tumor location, extent (presence of pyriform sinus apex involvement), and size, and passing the endoscope through the upper esophageal sphincter. The success rate of tissue sampling was assessed, and procedure-related complications were recorded. RESULTS: All patients were male, with a mean age of 69.9 ± 10.9 years (range 61-69 years). Tissue sampling using biopsy forceps was performed in 6/9 patients (66.7%). No complications related to moderate sedation or biopsy, including post-biopsy bleeding or respiratory distress, were reported. Histologic confirmation was successful in 5/6 patients (83.3%). Upper gastrointestinal lesions were evaluated in 7/9 (77.8%) patients in whom the scope passed through the lesion. CONCLUSIONS: EGD and EGD-guided forceps biopsy may be useful for the evaluation of hypopharyngeal cancer extent and tissue sampling, respectively.

Guidelines for the Surgical Management of Laryngeal Cancer: Korean Society of Thyroid-Head and Neck Surgery.

Korean Society of Thyroid-Head and Neck Surgery appointed a Task Force to develop clinical practice guidelines for the surgical treatment of laryngeal cancer. This Task Force conducted a systematic search of the EMBASE, MEDLINE, Cochrane Library, and KoreaMed databases to identify relevant articles, using search terms selected according to the key questions. Evidence-based recommendations were then created on the basis of these articles. An external expert review and Delphi questionnaire were applied to reach consensus regarding the recommendations. The resulting guidelines focus on the surgical treatment of laryngeal cancer with the assumption that surgery is the selected treatment modality after a multidisciplinary discussion in any context. These guidelines do not, therefore, address non-surgical treatment such as radiation therapy or chemotherapy. The committee developed 62 evidence-based recommendations in 32 categories intended to assist clinicians during management of patients with laryngeal cancer and patients with laryngeal cancer, and counselors and health policy-makers.

Prognostic Factors and Treatment Outcomes of Parotid Gland Cancer: A 10-Year Single-Center Experience.

OBJECTIVE: To investigate the treatment outcomes of parotid gland cancer at a single center over a 10-year period and to evaluate the prognostic significance of maximum standardized uptake value. STUDY DESIGN: Retrospective case series with chart review. SETTING: Academic care center. SUBJECTS AND METHODS: Ninety-eight patients with primary parotid gland cancer who were surgically treated at Yonsei University Head & Neck Cancer Clinic between January 1999 and December 2008 were analyzed. Patient data were collected retrospectively from medical charts. The investigators analyzed the association of clinicopathological factors and maximum standardized uptake value on (18)F-fluorodeoxyglucose positron emission tomography-computed tomography scan with disease-specific survival. RESULTS: Mean patient age was 49.7 years. Mean follow-up was 48.8 months. Thirty-three, 40, 30, and 23 patients had stage I, II, III, and IVA disease, respectively. Mucoepidermoid carcinoma was the most common histologic type (34.7%), followed by acinic cell carcinoma (27.6%). Eighteen patients (18.4%) experienced recurrences (mean recurrence gap, 20.6 months; range, 2-87 months). Five- and 10-year disease-specific survival rates were 93.6% and 81.8%, respectively. In the univariate analysis, pathologic T stage, pathologic lymph node status, resection margin, external parenchymal extension, and maximum standardized uptake value were significantly associated with disease-specific survival. Pathologic lymph node status and maximum standardized uptake value were independent prognostic factors in the multivariate analysis. CONCLUSION: Our single-center experience with parotid gland cancer treatment is consistent with the literature. Cervical lymph node metastasis and high maximum standardized uptake value are associated with poor survival in parotid gland cancer.

Phonatory outcome of 585 nm/pulsed-dye laser in the management of glottic leukoplakia.

OBJECTIVE: Vocal cord mucosectomy using pulsed-dye laser was assessed for its ability to completely remove lesions without deterioration of vocal quality in cases of vocal cord leukoplakia. To confirm the validity of a pulsed-dye laser, we retrospectively analyzed the treatment outcomes of patients who received surgery preceded by pulsed-dye laser and compared these with the outcomes of patients who received vocal cord mucosectomy using CO2 laser. METHODS: Between February 2007 and June 2012, 36 patients were enrolled. Seventeen patients received vocal cord treatment with a CO2 laser and 19 patients received operation with a pulsed-dye laser. To evaluate voice status, acoustic wave form analysis and electroglottography were done, and voice handicap index was measured before and after the operation. RESULTS: The entire lesion was removed in all patients. Compared to preoperative vocal parameters, the postoperative values for jitter were only improved in the pulsed-dye laser group. On stroboscopic findings, a diminution or lack of mucosal wave was observed in more CO2 laser cases than pulsed-dye laser cases. Significant improvement in voice handicap index results was only observed in the pulsed-dye laser group. CONCLUSION: Although long-term results with more patients are required to establish the validity of pulsed-dye laser, this study confirmed the merits of pulsed-dye laser for the en-bloc removal of vocal cord leukoplakia and improved voice outcome.

Tracheal reconstruction using chondrocytes seeded on a poly(L-lactic-co-glycolic acid)-fibrin/hyaluronan.

Reconstruction of trachea is still a clinical dilemma. Tissue engineering is a recent and promising concept to resolve this problem. This study evaluated the feasibility of allogeneic chondrocytes cultured with fibrin/hyaluronic acid (HA) hydrogel and degradable porous poly(L-lactic-co-glycolic acid) (PLGA) scaffold for partial tracheal reconstruction. Chondrocytes from rabbit articular cartilage were expanded and cultured with fibrin/HA hydrogel and injected into a 5 × 10 mm-sized, curved patch-shape PLGA scaffold. After 4 weeks in vitro culture, the scaffold was implanted on a tracheal defect in eight rabbits. Six and 10 weeks postoperatively, the implanted sites were evaluated by bronchoscope and radiologic and histologic analyses. Ciliary beat frequency (CBF) of regenerated epithelium was also evaluated. None of the eight rabbits showed any sign of respiratory distress. Bronchoscopic examination did not reveal stenosis of the reconstructed trachea and the defects were completely recovered with respiratory epithelium. Computed tomography scan showed good luminal contour of trachea. Histologic data showed that the implanted chondrocytes successfully formed neocartilage with minimal granulation tissue. CBF of regenerated epithelium was similar to that of normal epithelium. Partial tracheal defect was successfully reconstructed anatomically and functionally using allogeneic chondrocytes cultured with PLGA-fibrin/HA composite scaffold.

Robot-assisted versus endoscopic submandibular gland resection via retroauricular approach: a prospective nonrandomized study.

The aim of this study was to compare the short-term clinicopathological results of robot-assisted and endoscopic resection of the submandibular gland by the retroauricular approach. We present a prospective, non-random, study of 35 patients who had endoscope-assisted (n=22), or robot-assisted (n=13), resection of the submandibular gland using a retroauricular approach. Patients selected one of the two methods, and short-term clinical outcomes were then compared, including maximum diameter of the tumour and gland, length of incision, total operating time, amount of operative bleeding, amount and duration of drainage, duration of hospital stay, cosmesis, and complications. The operation was feasible in all patients with no appreciable operative complications or need to convert to a conventional open operation. The operating time of the robot-assisted group (63.4 (6.3)min) was comparable with that of the endoscopic group (66.5 (9.1)min) (p=0.15). There were no differences in the other clinical outcomes between the 2 groups. Both groups of patients were extremely satisfied with their postoperative cosmesis, and did not differ significantly (p=0.89). Robotic and endoscopic resection of the submandibular gland gave comparable early surgical outcomes and excellent cosmetic results. Despite the technical convenience for the surgeon, the robot gave no apparent clinical benefit over the endoscope in this series.

Carcinoma ex pleomorphic adenoma in the oral cavity: a huge oral cavity mass with neck metastasis.

Carcinoma ex pleomorphic adenoma (CEPA) is a rare, aggressive, poorly understood malignancy. In CEPA, an epithelial malignancy develops in association with a primary or recurrent benign pleomorphic adenoma. Carcinoma ex pleomorphic adenoma is very difficult to identify before surgery because the clinical presentation of many cases is similar to that of pleomorphic adenomas. The risk for malignancy increases with the duration of a mixed tumor. Treatment of CEPA must be individualized on the basis of the tumor location, involvement of adjacent structures, histologic subtype, and grade. The authors recently experienced a case of CEPA arising in the oral cavity with neck metastasis. The patient was a 70-year-old man presenting a huge mass that was present for 20 years and that slowly grew on the left side of the neck. We treated it with a total excision with wide margins and neck dissection. There was no recurrence during the follow-up period of 5 years up until now. We present a case of an unusually huge CEPA in the oral cavity.

Clinical characteristics of vocal polyps with underlying sulcus vocalis.

OBJECTIVE: This study aims to find a correlation between vocal fold polyps and sulcus vocalis and to investigate the character of such vocal fold polyps associated with sulcus vocalis. STUDY DESIGN: Retrospective clinical research. METHODS: A retrospective review of 280 patients who have been admitted and operated under general anesthesia for vocal fold polyps at a tertiary care medical center from March 2009 to July 2012 was performed. RESULTS: The patients were classified into two groups. Group A (18 patients) was defined as patients who have been diagnosed with vocal polyps coexisting with sulcus vocalis. Group B (262 patients) was designated to the rest of the patients who have been solely diagnosed with vocal fold polyps. The prevalence of an underlying sulcus vocalis associated with vocal polyps in the studied population overall was 6.4% (18/280). Considering the recurrence rate of vocal fold polyps in each group, it was 16.7% (three patients) in group A and 3.1% (eight patients) in group B. In general, there was an improvement in the voice quality after the operation in both groups. The degree of improvement was less substantial in group A rather than group B. CONCLUSION: When dealing with patients who have been diagnosed as vocal fold polyps, the possibility of coexisting sulcus vocalis should always be considered, and if diagnosed simultaneously, management of vocal polyps and sulcus vocalis must be sought for a better voice outcome and to reduce the chance of recurrence of vocal polyps.

Transoral robotic retropharyngeal lymph node dissection with or without lateral oropharyngectomy.

Retropharyngeal lymph node (RPLN) metastases can occur from advanced head and neck malignancies. Surgical access to RPLNs can be challenging. Considering the more aggressive conventional approach methods, there is an increasing need for minimally invasive techniques. Applying transoral robotic surgery (TORS) to access the RPLN has never been reported in the literature. The purpose of this study was to describe our experience with transoral robotic RPLN dissection for oropharyngeal and hypopharyngeal squamous cell carcinomas. We conducted a retrospective review of TORS cases performed at Severance Hospital, a tertiary care medical center from December 2011 to July 2012. Demographic, clinicopathologic, and treatment characteristics were abstracted from the medical record as well as complications and were analyzed descriptively. A total of 5 TORS procedures with transoral robotic RPLN dissection have been performed at Severance Hospital. Of these, 4 patients were treated for oropharyngeal squamous cell carcinoma and 1 for hypopharyngeal squamous cell carcinoma. The mean operation time for TORS including the robotic RPLN dissection was 84 ± 18.5 minutes. The operation time included time for docking of the robotic arms (4.8 ± 1.3 minutes), console working time for primary tumor removal (50 ± 8.9 minutes), and console working time for RPLN dissection (29.2 ± 9.4 minutes). No patients experienced complications related to the transoral robotic RPLN dissection. Transoral robotic RPLN dissection is a feasible approach for accessing retropharyngeal lymph nodes. This particular operative technique can serve as a minimal invasive surgery in removing pathologic RPLNs.

Use of pulsed dye laser in the treatment of sulcus vocalis.

OBJECTIVE: The pulsed dye laser (PDL) has been shown to be effective in the treatment of hypertrophic scars and keloids in dermatology. On the basis of histopathologic similarities between sulcus vocalis and scar tissue and numerous reports on the treatment of laryngeal lesions, especially scar tissue, with PDL, we evaluated the efficacy of treating sulcus vocalis with PDL. We named this surgical procedure PDL glottoplasty. STUDY DESIGN: Case series with planned data collection. SETTING: A university-based, tertiary care medical center. SUBJECTS AND METHODS: This study was conducted on 25 patients diagnosed with sulcus vocalis by videostroboscopy at the Gangnam Severance Hospital Otorhinolaryngology Department between August 2006 and February 2012. Energy delivery was fixed at 0.75 Joules (J) per pulse, and each vocal fold was administered 60 to 110 pulses (average 72.5 pulses) during each procedure. Aerodynamic, stroboscopic, and acoustic voice analyses were performed pre- and postoperatively. RESULTS: Although assessment was necessarily subjective, our study indicated that vocal folds showed decreased stiffness and improved mucosal wave properties after treatment, resulting in improved vibration and dysphonia. In the objective assessments, most patients who underwent PDL glottoplasty showed improvement in several postoperative voice analysis indices. The differences between preoperative and some postoperative voice parameter indices were statistically significant. CONCLUSION: We found PDL glottoplasty to be beneficial in the treatment of sulcus vocalis. Objective measurements of voice quality and normalization of vocal fold vibration improved after PDL treatment in most cases. Our results warrant further studies with larger numbers of participants and longer follow-up periods.

Transplantation of autologous chondrocytes seeded on a fibrin/hyaluronan composite gel into tracheal cartilage defects in rabbits: preliminary results.

Reconstruction of tracheal defects is one of the most difficult procedures in head and neck surgery. To date, various reconstructing techniques have been used with no consensus on the best approach. This study investigated the feasibility of using a fibrin/hyaluronic acid (HA) composite gel with autologous chondrocytes for tracheal reconstruction. Chondrocytes from autologous rabbit auricular cartilages were expanded and seeded into a culture dish at high density to form stable tracheal cartilages mechanically using a fibrin/HA composite gel. A 1-cm long by 0.5-cm wide defect was created by a scalpel on the cervical tracheae of six rabbits. Tissue-engineered cartilages using fibrin/HA composite were trimmed and fixed to the defect boundaries with tissuecol. Postoperatively, the site was evaluated endoscopically, histologically, radiologically, and functionally. None of the six rabbits showed signs of respiratory distress. Postoperatively, in all cases, rigid telescopic examination showed that the implanted scaffolds were completely covered with regenerated mucosa without granulation or stenosis. Histologically, the grafts showed no signs of inflammatory reaction and were covered with ciliated epithelium. Even when grafts were broken and migrated from their original insertion site, the implanted cartilages were well preserved. However, the grafts did show signs of mechanical failure at the implantation site. The beat frequency of ciliated epithelium on implants was very similar to that of normal respiratory mucosa. In conclusion, implants with autologous chondrocytes cultured with fibrin/HA showed good tracheal luminal contour, functional epithelial regeneration, and preservation of neocartilage without inflammation but lacked adequate mechanical stability.

Robot-assisted Supraomohyoid neck dissection via a modified face-lift or retroauricular approach in early-stage cN0 squamous cell carcinoma of the oral cavity: a comparative study with conventional technique.

BACKGROUND: Supraomohyoid neck dissection (SOND) in clinical N0 (cN0) neck of oral cavity squamous cell carcinoma (SCC) is performed by many head and neck surgeons showing improved regional control and disease-specific survival. However, disfiguring neck scars have been accepted to be unavoidable. In this study, we sought to introduce and evaluate the feasibility of our surgical technique to hide the external scar of neck dissection using the robotic system via a modified face-lift or retroauricular approach. METHODS: Twenty-six patients with cN0 oral cavity SCC were divided into two groups of robot-assisted neck dissection and conventional neck dissection via external cervical incision. The operation time, amount and duration of drainage, length of hospital stay, complications, number of retrieved lymph nodes, and satisfaction scores were compared. RESULTS: Mean operation time was longer in the robot-assisted group (157 ± 22 min) than the conventional group (78 ± 16 min) (P < 0.001). However, the amount and duration of drainage, hospital stay, retrieved lymph nodes, and complications were comparable. Because the postoperative scar was hidden by the auricle and hair, the satisfaction score was significantly higher in the robot-assisted group (P < 0.001). CONCLUSIONS: Robot-assisted SOND via a modified face-lift or retroauricular approach in cN0 oral cavity SCC was feasible compared to conventional technique and showed a clear cosmetic benefit. Longer operation time remains the drawback of this procedure. However, it could be considered for patients who require SOND and prefer to avoid external neck scar.

Feasibility of robot-assisted neck dissections via a transaxillary and retroauricular ("TARA") approach in head and neck cancer: preliminary results.

BACKGROUND: Recently, robot-assisted neck dissection in thyroid cancer patients with lateral neck node metastasis has been demonstrated to be feasible. We realized the necessity of technical modification in order to apply robotic system to comprehensive neck dissection for head and neck squamous cell carcinoma. This study examined the feasibility and safety of transaxillary and retroauricular ("TARA") approach for robotic neck dissection in patients with head and neck squamous cell cancer. METHODS: Four human cadaveric dissections were followed by robotic neck dissections in seven patients with oral cavity or laryngopharyngeal cancer through TARA incision. RESULTS: In all cases, vital structures including major vessels and nerves were preserved. The numbers of retrieved lymph nodes in robotic neck dissections were comparable with those in conventional neck dissections. CONCLUSIONS: Robotic neck dissection via TARA approach is a feasible and useful method with excellent cosmetic results for treating nodal metastasis in selected cases of head and neck squamous cell cancer.