Richard Chan Woo Park

The Role of Reconstruction for Transoral Robotic Pharyngectomy and Concomitant Neck Dissection

OBJECTIVE To evaluate the impact of primary reconstruction of postablative defects following transoral robotic surgery on function and the risk of orocutaneous fistula. DESIGN Prospective nonrandomized clinical trial. SETTING Tertiary academic medical center. PATIENTS Thirty-one patients treated with transoral robotic pharyngectomy for malignant disease. Each case was analyzed for patient age, sex, primary site of the tumor, pathologic characteristics, stage of disease, complications, fistula rate, and functional outcomes. Functional outcomes were assessed using the Performance Status Scale for Head and Neck Cancer Patients and the Functional Oral Intake Scale. INTERVENTIONS In 25 patients, the primary treatment was with transoral robotic pharyngectomy, and 6 cases were salvage procedures performed for recurrent disease following radiation (3 patients) or chemoradiation (3 patients). Twenty-six patients underwent a concomitant unilateral selective neck dissection, and 3 patients underwent concomitant bilateral selective neck dissections; 2 patients did not require a neck dissection for treatment of the primary malignant tumor. MAIN OUTCOME MEASURES Complication rate, fistula rate, and oral function. RESULTS Primary intraoral reconstruction was performed in all 31 patients. Musculomucosal advancement flap pharyngoplasty was performed in 25 patients with a concomitant velopharyngopasty (6 patients), and radial forearm free flap reconstruction was performed in 6 patients. There were no intraoperative complications; however, postoperatively, 1 patient developed a neck hematoma that was treated with bedside drainage and 4 patients sustained minor musculomucosal flap necrosis of the superior aspect of the flap. None of the patients developed a neck infection of salivary fistula. Endoscopic evaluation of swallowing demonstrated that none of the patients experienced aspiration or velopharyngeal reflux, and the performance Status Scale for Head and Neck Cancer Patients and the Functional Oral Intake Scale at 2 weeks, 2 months, 6 months, 9 months, and 1 year demonstrated a progressive improvement in diet, swallowing, and oral function. CONCLUSIONS Primary transoral robotic reconstruction may provide a benefit by decreasing the fistula rate in patients undergoing concomitant neck dissection. Patients regain excellent function following surgery and adjuvant therapy.

Polymorphous low‐grade adenocarcinoma of the head and neck: A population‐based study of 460 cases

Polymorphous low‐grade adenocarcinoma (PLGA) is a rare malignant neoplasm of the minor salivary glands. This study analyzes the demographic, clinicopathologic, incidence, and survival characteristics of head and neck PLGA (HN‐PLGA).

Reconstructive algorithm and classification system for transoral oropharyngeal defects

Transoral techniques for oropharyngeal tumors, such as transoral robotic surgery (TORS) and transoral laser microsurgery, require new reconstructive considerations.

Reconstruction of transoral robotic surgery defects: principles and techniques.

Early functional and oncological outcome studies suggest that transoral robotic surgery (TORS) may have a role for early stage cancers of the oropharynx. Unlike with traditional mandibular swing or pharyngotomy approaches, access to the oropharynx for reconstruction in TORS cases is limited. Maintaining a good functional result necessitates preserving physiological function where possible. The principles that should guide reconstructive surgeons include maintaining a velopharyngeal sphincter to prevent velopharyngeal insufficiency, maintaining sensate mucosa and restoring bulk in the tongue base to prevent aspiration, maintaining separation between the cervical and pharyngeal components, and covering exposed vessels in the pharynx. We present here principles and surgical techniques of TORS to reconstruct oropharyngeal defects using a subsite-based approach using secondary healing, local musculomucosal flaps, and free tissue transfer guided by the above principles.

Calcineurin inhibitor effects on growth and phenotype of human airway epithelial cells in vitro

Calcineurin inhibitors (CIs) cyclosporin and tacrolimus form the basis for immunosuppression in lung transplantation, yet also exert biological effects on nonlymphoid tissue. With the advent of inhaled cyclosporin, we hypothesize that the airway epithelium is also subject to CI effects at high doses. The aim of this study was to identify human tracheobronchial epithelial cell (hTBEC) calcineurin gene expression and quantify effects of CIs on hTBEC growth, interleukin‐1‐β stimulated IL‐8 production and hTBEC phenotype. Cyclophillin B and FK‐associated binding protein, calcineurin A (α and β), and NFATC3 and NFAT5 were detected in hTBEC cultures by RT‐PCR. Acute and chronic cyclosporine treatment 1000 ng/mL significantly inhibited hTBEC proliferation, while tacrolimus did not (range of 10 ng/mL to 1000 ng/mL for acute treatment, 50 ng/mL for chronic treatment). Cyclosporin at 10 000 ng/mL significantly increased LDH release by well‐differentiated hTBEC cultures (n = 6) and trended towards significance at 1000 ng/mL. IL1‐β stimulated IL‐8 production was significantly increased in rapidly growing hTBEC cultures (n = 8) treated with cyclosporin (p = 0.049). Prolonged treatment of well‐differentiated hTBECs at air‐liquid‐interface (ALI) with cyclosporin 1000 ng/mL significantly reduced intact multilayered mucociliary epithelium (p = 0.009). Inhibition of hTBEC growth, stimulation of IL‐8 production and long‐term effects on mucociliary phenotype and intact multi‐layered epithelium suggest that cyclosporin may have a direct toxic effect on airway epithelium after transplantation.

Combined donor specific transfusion and anti‐CD154 therapy achieves airway allograft tolerance

Background: The state of tolerance allows long term graft survival without immunosuppressants. Lung transplantation tolerance has not been consistently achieved in either small or large animal models. Methods: The mechanisms and effectiveness of a tolerance induction protocol consisting of donor specific transfusion (DST; day 0) and a short course of co-stimulatory blockade (anti-CD154 antibody; days −7, −4, 0 and +4) were studied in the mouse heterotopic tracheal transplant model of chronic lung rejection. C57BL/6 mice received BALB/c tracheal grafts (day 0) and were treated with DST alone, anti-CD154 alone, the combination (DST/anti-CD154), or no treatment. No non-specific immunosuppressants were used. Results: DST/anti-CD154 in combination, but neither treatment alone, markedly prolonged the lumen patency and survival (>100 days) of fully histo-incompatible allografts (p<0.05 versus control allografts at every time point studied up to 16 weeks) without immunosuppression. This protocol was donor antigen specific as third party grafts (C3H) were promptly rejected. In addition, DST/anti-CD154 did not result in mixed chimerism but induced transplantation tolerance via a peripheral mechanism(s), which included significantly reduced cytotoxic T cell activity (p<0.001) and a significantly increased percentage of CD4+CD25+ cells (p = 0.03). Conclusions: The DST/anti-CD154 protocol successfully induced and maintained long term, donor specific tolerance in the mouse heterotopic airway graft model of chronic lung rejection. This finding may lead us closer to successful tolerance induction in lung transplantation.

A population-based analysis of Head and Neck hemangiopericytoma.

Hemangiopericytomas (HPC) are tumors that arise from pericytes. Hemangiopericytomas of the head and neck are rare and occur both extracranially and intracranially. This study analyzes the demographic, clinicopathologic, treatment modalities, and survival characteristics of extracranial head and neck hemangiopericytomas (HN‐HPC) and compares them to HPCs at other body sites (Other‐HPC).

The price of free tissue transfer after tongue reconstruction: quantifying the risks

To evaluate the preoperative variables, mean operative time, morbidity, and mortality associated with reconstruction of partial glossectomy defects.

Postoperative complications of total laryngectomy in diabetic patients: Thyroidectomy Outcomes in DM Patients

Analyze postoperative complications of total laryngectomies (TL) in patients with diabetes mellitus and apply these data toward preoperative management of diabetic patients undergoing TL.

PX3.102, a novel chinese herb extract, diminishes chronic airway allograft rejection.

More effective immunosuppressants are needed to improve lung-transplantation survival. PX3.102 is a novel immunosuppressant isolated from a mixture of traditional Chinese herbs. We tested its protective role on chronic lung rejection in the heterotopic tracheal transplant model. C57BL/6 mice received BALB/c tracheal grafts and were treated with PX3.102, cyclosporine A, or vehicle. PX3.102 improved tracheal allograft lumen patency (*P<0.01 vs. vehicle and P=0.14 vs. cyclosporine A) but not epithelialization (P>0.2 vs. vehicle). Subsequent in vitro studies demonstrated that PX3.10 was toxic to fully differentiated human tracheal epithelial cells in a dose-dependent manner. PX3.102 markedly suppressed antigen-specific lymphocyte proliferation in vitro at a concentration 10 times lower than cyclosporine A. In conclusion, PX3.102, a promising and potent immunosuppressant, although exhibiting toxicity to airway epithelial cells at high doses, is effective in inhibiting chronic airway allograft rejection.