Faculty Bibliography

LEARNING OBJECTIVES: After studying this article, the participant should be able to: 1. Evaluate clinically a patient with brachial plexus paralysis and define the appropriate electrophysiologic and radiographic studies. 2. Differentiate between preganglionic (root) avulsion and postganglionic lesions and identify appropriate motor donors and nerve grafts. 3. Describe various nerve reconstructive strategies and make appropriate selection of secondary procedures for shoulder stability, elbow flexion, and hand reanimation. 4. Anticipate the possible functional outcome

BACKGROUND: Limited availability of donor nerve grafts along with donor-site morbidity has stimulated research toward other alternatives for the repair of severe nerve injuries. The authors provide a comprehensive review of 'tubulization' biology and share with the readers their experience with two cases of obstetrical brachial plexus paralysis where they used vein grafts with 'minced' nerve tissue, to accomplish connectivity of proximal donors with distal targets. Usage of vascular tissue as conduits for nerve regeneration was first reported more than 100 years ago. It has been suggested that the vein's wall allows diffusion of the proper nutrients for nerve regeneration, acts as a barrier against ingrowth of scar, and prevents wastage of regenerating axons. METHODS: In this report, vein grafts of 2.4, 3.5, and 22 cm in length filled with minced peripheral nerve tissue were used as bridges in two cases of obstetrical brachial plexus paralysis. RESULTS: By filling the vein lumen with small pieces of nerve tissue suspended in a heparinized saline solution, a potential problem associated with vein collapse caused by compression was solved. CONCLUSION: The authors suggest that tubulization techniques should be kept in mind in clinical practice when autologous nerve grafts are insufficient for distal target connectivity or as an alternative to conventional nerve grafts for bridging certain nerve defects

OBJECTIVE: The mechanism of neovascularization during the proliferative phase of infantile hemangioma is poorly understood. It is known that circulating bone marrow-derived endothelial progenitor cells (EPCs) form new blood vessels in ischemic tissues using mediators regulated by the transcription factor, HIF-1alpha. Mobilization of EPCs is enhanced by VEGF-A, matrix metalloproteinase (MMP)-9, and estrogen, whereas homing is secondary to localized expression of stromal cell-derived factor-1alpha (SDF-1alpha). We examined whether these mediators of EPC trafficking are upregulated during the proliferation of infantile hemangioma. METHODS AND RESULTS: Surgical specimens and blood samples were obtained from children with proliferating hemangioma and age-matched controls (n=10, each group). VEGF-A and MMP-9 levels were measured in blood, and tissue sections were analyzed for SDF-1alpha, MMP-9, VEGF-A, and HIF-1alpha. The role of estrogen as a modulator of hemangioma endothelial cell growth was also investigated. We found that all these mediators of EPC trafficking are elevated in blood and specimens from children with proliferating infantile hemangioma. In vitro, the combination of hypoxia and estrogen demonstrated a synergistic effect on hemangioma endothelial cell proliferation. CONCLUSIONS: These findings demonstrate that proliferating hemangiomas express known mediators of vasculogenesis and suggest that this process may play a role in the initiation or progression of this disease

OBJECTIVES: To explore distribution of stage at diagnosis and relative survival rates among US adults with oral cavity cancer in relation to race, and over time. METHODS: We obtained 1973-2002 oral cancer incidence data from the Surveillance, Epidemiology, and End Results (SEER) Program, and computed proportions for each oral cavity site by stage at diagnosis, tumor size, and 5-year relative survival rates among Whites and Blacks. RESULTS: A total of 46 855 cases of oral cavity cancer were reported to the SEER registry among adults > or =20 years between 1973 and 2002. African-Americans had a significantly higher proportion of cancer, mainly in the tongue, that had spread to a regional node or to a distant site at diagnosis than Whites: 67% versus 49% of tongue cancers reported from 1973 to 1987 (P < 0.001), and 70% versus 53% of those reported from 1988 to 2002 (P < 0.001). They had a significantly higher proportion of tongue cancer that were >4 cm in diameter at time of diagnosis (59% versus 44%; P < 0.001), and black men in particular experienced lower 5-year relative survival rates than white men, in particular, for tongue cancer (25% versus 43% from 1973 to 1987, and 31% versus 53% from 1988 to 2002). CONCLUSION: There are significant racial disparities with respect to stage at diagnosis and survival among adults with oral cancer reported to the SEER registry from 1973 to 2002. One possible explanation for the lower survival among Blacks may be a difference in access to, and utilization of, healthcare services

In this study we investigated the role of endothelin-1 (ET-1) and its peripheral receptor (ET-A) in carcinoma-induced pain in a mouse cancer pain model. Tumors were induced in the hind paw of female mice by local injection of cells derived from a human oral squamous cell carcinoma (SCC). Significant pain, as indicated by reduction in withdrawal thresholds in response to mechanical stimulation, began at four days after SCC inoculation and lasted to 28 days, the last day of measurement. Intra-tumor expression of both ET-1 mRNA and ET-1 protein were significantly upregulated compared to normal tissue, and local administration of the ET-A receptor selective antagonist, BQ-123 (100 microM) significantly elevated withdrawal thresholds, indicating the induction of an antinociceptive effect. These findings support the suggestion that ET-1 and ET-A receptors contribute to the severity of carcinoma-induced soft tissue cancer pain

PURPOSE: The workup for oral malignancy involving the mandible typically involves a head and neck exam, laboratory studies, a panoramic radiograph, and computed tomography (CT) or magnetic resonance imaging of the head and neck to evaluate the primary lesion and cervical lymph nodes. Panoramic plain film radiography of the mandible is often unreliable for detecting bony invasion; therefore, other imaging studies are necessary before staging is complete. Bony invasion is typically imaged with the use of conventional CT scanners. In this article we relate the use of cone beam computed tomography (CBCT) to image the mandible with less cost and morbidity to the patient and its use in the evaluation and treatment planning of mandibular cancer. MATERIALS AND METHODS: A retrospective review of 3 patients with mandibular malignancies was performed. All patients had a panoramic radiograph, magnetic resonance imaging, and chest radiograph, in addition to laboratory studies. CBCT scans were ordered, after bony involvement was suspected, and compared with the other imaging studies. RESULTS: Two patients with squamous cell carcinoma of anterior mandible and 1 patient with osteogenic sarcoma were reviewed. In all cases CBCT aided the evaluation of the mandible. The cone beam panoramic view, as part of the CBCT, was used to determine extent of resection. CONCLUSION: CBCT can accurately aid in evaluating and treatment planning for malignant tumors of the mandible with less cost and decreased radiation to the patient relative to conventional CT

PURPOSE: The treatment of locally aggressive lesions of the mandible can have a profound effect on a patient's quality of life (QOL), both functionally and psychologically. The more knowledge available on this subject, the better a patient can be prepared and counseled. PATIENTS AND METHODS: Patients undergoing mandibular resection with immediate insertion of a reconstruction plate and subsequent staged reconstruction for the management of locally aggressive lesions of the mandible at the University of California at San Francisco were studied over a 6-year period from 1999 to 2005. The staged reconstruction involved bone grafting, removal of the reconstruction plate, vestibuloplasty, implant insertion, and construction of an implant-supported prosthesis. Each patient completed a modified University of Washington Quality of Life version 4 questionnaire after reaching his or her highest level of reconstruction. RESULTS: A total of 26 patients were identified as fulfilling the criteria for this study. Eight patients did not progress beyond resection, bone grafting, and subsequent removal of the bone plate. Seven patients progressed all the way through the 7 stages to an implant-supported prosthesis. The most important determinants of the patient's subsequent QOL were time interval from initial resection and stage of reconstruction; the greater the time interval from initial resection and the further the stage of reconstruction reached, the better the QOL. Resections involving the mandibular angle had a negative effect on appearance, and resections involving the parasymphysis and symphysis region carried a worse overall QOL, possibly due to difficulty with chewing and lip support. Males reached a higher overall QOL than females. Although most patients seemed satisfied with their overall QOL, 73% had some concerns regarding appearance, 42% had concerns with chewing, 42% had concerns regarding their mood, 35% felt more anxious since the surgery, 23% had some residual pain and discomfort, 19% had concerns with swallowing, and 15% had concerns with taste. CONCLUSION: These and other findings necessitate further investigation and confirmation