Jonathan W. Shum

Low Prealbumin Level Is a Risk Factor for Microvascular Free Flap Failure

PURPOSE The purposes of this study were 1) to estimate and compare the 1-month survival rates of patients with acute malnutrition (low prealbumin level) and patients who are not malnourished (normal prealbumin level) and 2) to identify risk factors associated with microvascular free flap failure. MATERIALS AND METHODS To address the research purposes, we designed a retrospective cohort study and enrolled a sample composed of patients who underwent head and neck microvascular reconstruction and had prealbumin levels measured in the perioperative period. The primary predictor variable was nutritional status (low vs normal prealbumin level). The primary outcome variable was flap survival. One-month survival rates were estimated by use of Kaplan-Meier survival analyses. Risk factors for free flap failure were identified by use of multivariate marginal Cox proportional hazards modeling. RESULTS The sample was composed of 162 patients who underwent microvascular free tissue transfer during the study enrollment period. The 1-month survival estimates for patients who were and were not malnourished were 76.5% (95% confidence interval [CI], 48.8% to 90.5%) and 95.2% (95% CI, 90.1% to 97.7%), respectively (P = .002). In the adjusted Cox hazards proportions model, acute malnutrition was associated with a 4-fold increased risk of failure (P = .04) in comparison with those patients with a normal nutritional status. CONCLUSIONS Acute malnutrition in patients undergoing microvascular free flap reconstruction in the head and neck region was associated with an increased risk for free flap failure.

Resection and immediate reconstruction of a pediatric vascular malformation in the mandible: case report.

Arteriovenous malformations (AVMs) within the mandible are rare and potentially life-threatening conditions that can pose a therapeutic dilemma. We present the case of a child with significant spontaneous gingival bleeding, radiographic evidence of a space-occupying lesion of the mandible, and delayed diagnosis and treatment because of parental reluctance to accept invasive treatment. Imaging studies and intravascular embolization with coils limited, but did not stop blood flow to this lesion. Resection of the mandible was the definitive treatment. The AVM was removed from the resected segment and the bone was replaced as a free graft, thereby avoiding a second site morbidity. Two years after surgery the replaced segment was well consolidated with moderate vertical resorption-remodeling.

Parotid lymphoma: A review of clinical presentation and management

Lymphoma of the parotid gland is a relatively rare occurrence among head and neck tumors. Presentation is indistinguishable from other swellings of the parotid gland; therefore, it is important to consider lymphoma in the differential diagnosis when examining parotid swellings. Parotid lymphomas are most likely to be B-cell non-Hodgkin lymphoma of 1 of 3 types, which include follicular, marginal zone, and diffuse large B cell, although other histologic patterns have been described. We present a review of 3 patients with parotid lymphoma who presented to the University of Maryland Medical Centers Department of Oral and Maxillofacial Surgery with facial swelling. Two patients were diagnosed with follicular lymphoma, whereas the third was diagnosed with marginal zone lymphoma.

Robotic surgery: a new approach to tumors of the tongue base, oropharynx, and hypopharynx.

Oropharyngeal cancer was traditionally treated with en bloc resection of the tumor via lip-split mandibulotomy approach, often with adjuvant radiation and chemotherapy. In the 1990s, organ-sparing definitive chemoradiation therapy without surgery became the standard of care for oropharyngeal squamous cell carcinoma. Although organ-sparing treatment provided acceptable locoregional disease control with preservation of anatomic organs adjacent to the tumors and less disfiguration from lack of surgical incisions, it often resulted in significant deficits in speech and swallowing. This article reviews a current organ-and-function preserving approach to oropharyngeal carcinoma using the surgical robot.

A technique for the treatment of oral–antral fistulas resulting from medication-related osteonecrosis of the maxilla: the combined buccal fat pad flap and radical sinusotomy

OBJECTIVE Bisphosphonates and monoclonal antibodies directed at osteoclastic function are frequently used to treat postmenopausal and corticosteroid-induced osteoporosis. They are also used in the treatment of certain metastatic malignancies. However, osteonecrosis of the jaw has been reported after intravenous, subcutaneous, or oral use of these agents. More than 12 million Americans and another 20 million worldwide are thought to be taking a bisphosphonate. Exposed bone with oral-antral fistulas has been known to occur increasingly as a specific presentation of what is now termed medication-related osteonecrosis of the jaws (MRONJ) with a specific International Classification of Diseases, 10th revision (ICD-10) code. Oral-antral communications caused by bisphosphonate concomitant with secondary sinusitis represent a unique treatment challenge for the oral and maxillofacial surgeon. The purpose of this article is to demonstrate a simple but effective technique to treat oral-antral communications caused by MRONJ. STUDY DESIGN With the review and approval of the University of Miami Internal Review Board, we identified 23 patients who had undergone this surgical procedure. RESULTS We report a 100% resolution of osteonecrosis of the jaw (ONJ) and sinusitis with repneumatization. CONCLUSIONS The buccal fat pad and radical sinustomy can be used as an effective and predictable technique for the resolution of oral-antral fistulas caused by MRONJ.

Adenoid cystic carcinoma of the minor salivary glands: a retrospective series of 29 cases and review of the literature

OBJECTIVE Approximately 78% of minor salivary gland tumors are malignant, of which adenoid cystic carcinoma (ACC) represents 15% in our series. ACC is an uncommon tumor characterized by slow growth and a high potential for recurrence. This series of 29 consecutive patients examines clincopathologic features, management, and survival outcomes. MATERIALS AND METHODS This study is a retrospective chart review of 29 patients with ACC of the minor salivary glands in a period of 23 years (1989 and 2012). RESULTS The mean age was 61.2 years (16-89 years), with no gender predilection. The majority occurred in the palate/maxilla (66%) and initial presentation was stage IV. Mean follow-up was 42.6 months. Recurrence rate was 10% local, 14% distant over the observation period. CONCLUSIONS The palate/maxilla is the preferred location for occurrence, and initial presentation at stage IV is common. Postoperative radiation remains a common strategy to prevent local recurrence in lesions with adverse features.

Reconstruction of large mandibular defects using autologous tissues generated from in vivo bioreactors

Reconstruction of large mandibular defects is clinically challenging due to the need for donor tissue of appropriate shape and volume to facilitate high fidelity repair. In order to generate large vascularized tissues of custom geometry, bioreactors were implanted against the rib periosteum of 3-4year-old sheep for nine weeks. Bioreactors were filled with either morcellized autologous bone, synthetic ceramic particles, or a combination thereof. Tissues generated within synthetic graft-filled bioreactors were transferred into a large right-sided mandibular angle defect as either avascular grafts (n=3) or vascularized free flaps (n=3). After twelve additional weeks, reconstructed mandibular angles were harvested and compared to contralateral control angles. Per histologic and radiologic evaluation, a greater amount of mineralized tissue was generated in bioreactors filled with autologous graft although the quality of viable bone was not significantly different between groups. Genetic analyses of soft tissue surrounding bioreactor-generated tissues demonstrated similar early and late stage osteogenic biomarker expression (Runx2 and Osteocalcin) between the bioreactors and rib periosteum. Although no significant differences between the height of reconstructed and control mandibular angles were observed, the reconstructed mandibles had decreased bone volume. There were no differences between mandibles reconstructed with bioreactor-generated tissues transferred as flaps or grafts. Tissues used for mandibular reconstruction demonstrated integration with native bone as well as evidence of remodeling. In this study, we have demonstrated that synthetic scaffolds are sufficient to generate large volumes of mineralized tissue in an in vivo bioreactor for mandibular reconstruction. STATEMENT OF SIGNIFICANCE A significant clinical challenge in craniofacial surgery is the reconstruction of large mandibular defects. In this work, we demonstrated that vascularized tissues of large volume and custom geometry can be generated from in vivo bioreactors implanted against the rib periosteum in an ovine model. The effects of different bioreactor scaffold material on tissue ingrowth were measured. To minimize donor site morbidity, tissues generated from bioreactors filled with synthetic graft were transferred as either vascularized free flaps or avascular grafts to a large mandibular defect. It was demonstrated that synthetic graft in an in vivo bioreactor is sufficient to produce free tissue bone flaps capable of integrating with native tissues when transferred to a large mandibular defect in an ovine model.

Bone Tissue Engineering Challenges in Oral & Maxillofacial Surgery.

Over the past decades, there has been a substantial amount of innovation and research into tissue engineering and regenerative approaches for the craniofacial region. This highly complex area presents many unique challenges for tissue engineers. Recent research indicates that various forms of implantable biodegradable scaffolds may play a beneficial role in the clinical treatment of craniofacial pathological conditions. Additionally, the direct delivery of bioactive molecules may further increase de novo bone formation. While these strategies offer an exciting glimpse into potential future treatments, there are several challenges that still must be overcome. In this chapter, we will highlight both current surgical approaches for craniofacial reconstruction and recent advances within the field of bone tissue engineering. The clinical challenges and limitations of these strategies will help contextualize and inform future craniofacial tissue engineering strategies.

Evaluation and Staging of the Neck in Patients with Malignant Disease

This article presents an overview of the evaluation and staging of the neck in the context of malignant disease. The current tumor-nodes-metastasis (TNM) nodal classification is reviewed followed by a brief discussion of the common malignant processes encountered in the head and neck and their associated risk factors for cervical metastasis. Common imaging modalities, such as ultrasound, magnetic resonance imaging, Computed tomography, and positron emission tomography, for the investigation of the neck are also summarized.

Oral Surgery in Patients Undergoing Chemoradiation Therapy

Oral health care in patients undergoing chemotherapy and/or radiation therapy can be complex. Care delivered by a multidisciplinary approach is timely and streamlines the allocation of resources to provide prompt care and to attain favorable outcomes. A hospital dentist, oral and maxillofacial surgeon, and a maxillofacial prosthodontist must be involved early to prevent avoidable oral complications. Prevention and thorough preparation are vital before the start of chemotherapy and radiation therapy. Oral complications must be addressed immediately and, even with the best management, can cause delays and interruption in treatment, with serious consequences for the outcome and prognosis.