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Biomedical subjects

C H Snyderman

Publications and source records attributed to C H Snyderman.

At least 37 records · Page 2Linked to original sources
PubMed1997

Trigeminal neurotrophic ulceration.

A 74 year-old female developed a trigeminal neurotrophic ulcer (TNU) 20 years following surgical ablation of the trigeminal nerve. The diagnosis of this unusual disorder is suggested when an ulcerative lesion develops. In the ala nasi in a patient with trigeminal sensory loss. A history of self-induced trauma to that area and some form of mental impairment further support the diagnosis.Exclusion of basal cell carcinoma and other causes of facial ulceration is mandatory before the diagnosis of TNU is established.

Case Reports↗
PubMed1997

QT interval changes following neck dissection. A stratified prospective study.

Studies from Europe have suggested that neck dissection, especially right radical neck dissection, causes a dangerous prolongation of the QT interval. Sudden cardiac arrest due to QT prolongation has been reported following right radical neck dissection. We investigated the prevalence of QT interval prolongation following neck dissection. Electrocardiogram tracings from 45 patients who underwent different combinations of neck dissection were studied. Preoperative and postoperative tracings were interpreted by a cardiologist blinded to the patient identification of each tracing. There were 28 unilateral neck dissection patients and 17 bilateral neck dissection patients eligible for analysis. There were 7 patients in the classic right radical neck dissection group, and only 3 of these had no neck dissection on the left. Comparisons of preoperative versus postoperative corrected QT interval for all subjects did not indicate a significant change. Stratification by neck dissection type (radical, modified or selective, and carotid artery resection) or by side dissected (left, right, or both) also showed no significant differences. No malignant arrhythmias were encountered. Thus, in contrast to the European experience, our findings show no significant predictable change in the QT interval after any of the combinations of neck dissection. Head and neck surgeons should be aware of the possibility of postoperative QT interval prolongation following neck dissection, although in the absence of other risk factors it appears to be a rare occurrence.

Analysis of Variance↗
PubMed1996

Management and long-term outcome of adenoid cystic carcinoma with intracranial extension: a neurosurgical perspective.

Adenoid cystic carcinoma is a tumor of minor and major salivary glands that often invades the cranial base and intracranial cavity via local and perineural spread. In the past, the role of neurosurgeons in managing these tumors has been limited. The growth of interdisciplinary cranial base surgical approaches has now increased the involvement of neurosurgeons in the management of these tumors. We present a series of 16 patients with adenoid cystic carcinomas with cranial base and intracranial extension, the largest series reported in the neurosurgical literature. We have focused our approach on a neurosurgical perspective and made recommendations for the treatment of these tumors in relation to the following specific aspects of this disease. 1) The management of the carotid artery: In our experience, when the carotid artery is involved by tumor, a preliminary cerebral revascularization procedure with a cervical carotid to middle cerebral artery vein bypass graft should be performed before tumor resection. 2) The management of the cavernous sinus and orbit: Cavernous sinus tumor should be removed as fully as possible, but every effort should be made to preserve the IIIrd and IVth cranial nerves to achieve optimal functional and cosmetic results. The orbit should be exenterated when there is intraconal involvement; otherwise, intraorbital tumor can be removed with orbital preservation. 3) The use of palliative surgery: We have found that the use of palliative surgery can be considered even in patients whose extent of local disease precludes a surgical cure. The slow progression of the disease allows for long-term survival of many patients with advanced local disease and even of those with metastatic disease. 4) The long-term survival of these patients: In our series, six patients had no evidence of local disease and a mean survival of 72 months, one living patient had evidence of local disease and has survived 56 months, eight patients died of disease, with a mean survival of 137 months, and one patient died of complications after surviving for 63 months.

Adult↗
PubMed1996

Hydroxyapatite cement to repair skull base defects: radiologic appearance.

PURPOSE: To describe the radiologic appearance of hydroxyapatite cement (HAC), which, when mixed with liquid, forms a paste that can be contoured to osseous defects and, over time, becomes "osseointegrated" (native bone grows into the pores of the HAC and forms a strong chemical bond with the substance). METHODS: Between March 1992 and June 1993, 24 adults (16 men, eight women) underwent skull base surgery that included reconstruction or closure with HAC. Fourteen patients had HAC placed in the paranasal sinuses or facial bones, and 10 had HAC placed in the mastoid cavity. RESULTS: HAC is homogeneously radiopaque on CT scans and plain radiographs. Large amounts (ablating a frontal sinus or mastoid air cells) are readily seen; small amounts are inconspicuous. On MR images, HAC is a signal void. Infected HAC in one patient was surrounded be enhancing soft tissue on MR images, separated from native bone by an irregular radiolucent cleft on CT scans. CONCLUSIONS: HAC is a valuable addition to the surgical armamentarium for the repair of skull base defects. More experience will determine the time course for normal osseointegration, as well as the typical appearance of infection.

Adult↗
PubMed1995

Inhibition of growth of a murine squamous cell carcinoma by a cyclooxygenase inhibitor increases leukotriene B4 production.

OBJECTIVE: To determine the role of metabolites of arachidonic acid in the growth of squamous cell carcinomas of the head and neck. DESIGN: Investigation of the effect of a cyclooxygenase inhibitor, piroxicam, on the growth of squamous cell carcinoma in a murine model. INTERVENTION: C3H/HeJ mice bearing squamous cell carcinoma (SCCVII) were treated with piroxicam (0.08 mg/d, orally) for 30 days beginning 1 day before tumor inoculation. MAIN OUTCOME MEASURES: Decrease in tumor volumes and tumor growth rates. RESULTS: Significant inhibition of tumor growth (P = .002) and final tumor weight (P = .0007) was noted in the group receiving piroxicam therapy. Prostaglandin E2 levels in the tumor tissue were unrelated to treatment or tumor size. Increased levels of leukotriene B4 were observed in the piroxicam-treated group (P = .03), and larger tumors were associated with decreased leukotriene B4 levels (P = .0001). CONCLUSIONS: Cyclooxygenase inhibitors may be effective in the treatment of some squamous cell carcinomas. The therapeutic effect of cyclooxygenase inhibitors may result from shunting into the lipoxygenase pathway of arachidonic acid metabolism.

Animals↗
PubMed1995

A reappraisal of the squamous cell carcinoma antigen as a tumor marker in head and neck cancer.

OBJECTIVE: To analyze serial measurements of squamous cell carcinoma antigen (SCCAg) to determine its prognostic significance in squamous cell carcinoma of the head and neck (SCCHN). DESIGN: Retrospective analysis of serial SCCAg measurements in 75 patients with squamous cell carcinoma of the head and neck. Serum samples were obtained preoperatively and at postoperative intervals ranging from 1 week to 36 months. Serum SCCAg levels were determined by radioimmunoassay. SETTING: Oncologic head and neck practice at a tertiary referral hospital. PATIENTS: Tumor Registry data of 75 consecutive patients with at least three postoperative SCCAg determinations were reviewed to provide equal numbers of patients with and without recurrent disease. All patients who remained disease-free were followed up for at least 2 years. All patients were previously untreated and underwent surgical therapy. MAIN OUTCOME MEASURES: Association of postoperative SCCAg levels and 2-year disease-free survival. RESULTS: No differences in preoperative levels were noted, but SCCAg levels predicted 2-year disease-free survival at 6, 9, and 12 months after surgery. The ratio of post-operative SCCAg levels to preoperative and early post-operative levels also provided prognostic information. CONCLUSIONS: Serial measurements of SCCAg postoperatively in patients with head and neck cancer predict outcome and may allow for earlier detection of recurrent disease. Further studies are needed to determine if earlier detection can be translated into improved survival.

Antigens, Neoplasm↗
PubMed1995

Superiority of the T and N integer score (TANIS) staging system for squamous cell carcinoma of the oral cavity.

An alternative to the TNM classification system has been proposed for patients with head and neck cancer. The T and N integer score (TANIS) system adds the integer values of T and N classifications. The TNM and TANIS staging systems were retrospectively evaluated for 186 patients with squamous cell carcinoma of the oral cavity (tongue and floor of mouth). The TANIS system was found to better separate the patients into prognostic groups and allowed a more accurate prediction of disease-free survival.

Carcinoma, Squamous Cell↗
PubMed1995

Practical Applications of Image-Guided Navigation during Anterior Craniofacial Resection.

Intraoperative image-guided navigation allows the surgeon to identify anatomic landmarks obscured by overlying normal tissue, neoplasms, infection, or previous surgery. This case presentation illustrates some of the practical applications of the ISG image-guided navigation system during anterior cranial base surgery. The advantages and the pitfalls of the ISG system are discussed.

Case Reports↗
PubMed1995

Chordomas and chondrosarcomas of the cranial base: results and follow-up of 60 patients.

The management of chordomas and chondrosarcomas involving the cranial base remains controversial. The options for therapy include biopsy, partial resection, radical resection, and various forms of radiotherapy. In this article, we analyze the outcome of 60 patients with cranial base chordoma or chondrosarcoma treated with extensive surgical resection between 1984 and 1993. Forty-six patients had chordomas, and 14 had low-grade chondrosarcomas; 50% of these patients had been treated previously. Preoperative studies included computed tomography, magnetic resonance imaging, cerebral angiography, and balloon occlusion test of the internal carotid artery, as indicated. Magnetic resonance imaging was performed on all patients during follow-up. The surgical approaches used for tumor resection were predominantly the following: subtemporal, transzygomatic, transcavernous, and transpetrous apex; subtemporal and infratemporal; extended frontal; and extreme lateral transcondylar. Staged operations with a combination of approaches were used when necessary (52% of cases) to remove a tumor more completely. Statistical analysis was done by the chi 2 test and correlation matrix. Sixty-seven percent of the patients had total or near-total resection. Twenty percent of the patients received postoperative radiotherapy. Eleven patients died during the postoperative follow-up period, nine with chordomas and two with chondrosarcomas. Three patients died because of systemic complications within 3 months after surgery, five died because of tumor recurrence, one died from unrelated causes, and two died from late complications of radiotherapy. The recurrence-free survival rate for all tumors was 80% at 3 years and 76% at 5 years. Chondrosarcomas had a better prognosis than chordomas (recurrence-free survival rates, 90% at 5 years and 65% at 5 years, respectively; P = 0.09). Patients who had undergone previous surgery had a greater risk of recurrence (5-year recurrence-free survival rate, 64%) than did patients who had not undergone previous surgery (5-year recurrence-free survival rate, 93%; P < 0.05). Patients with total or near-total resection had a better 5-year recurrence-free survival rate (84%) than did patients with partial or subtotal resection (64%) (P < 0.05). Postoperative leakage of cerebrospinal fluid was the most frequent complication (30% of patients) and was found to increase the risk of permanent disability. Patients who had undergone previous radiotherapy had a greater risk of death in the postoperative period (within 3 months of their operations) and during follow-up. However, total or near-total resection did not increase the rate of postoperative disability.(ABSTRACT TRUNCATED AT 400 WORDS)

Adolescent↗
PubMed1995

Prognostic significance of prostaglandin E2 production by mononuclear cells and tumor cells in squamous cell carcinomas of the head and neck.

Prostaglandin E2 (PGE2) has been implicated as a cause of immunosuppression in patients with head and neck cancer. To determine the relative contribution of tumor cells and mononuclear cells to PGE2 levels in vivo, tumor cells and tumor-infiltrating mononuclear cells (TIMC) were isolated from fresh tumor biopsy specimens of 23 patients with squamous cell carcinoma of the head and neck (SCCHN) by using enzymatic digestion and differential gradient centrifugation. Peripheral blood mononuclear cells (PBMC) and lymph node mononuclear cells (LNMC) from metastatic and nonmetastatic lymph nodes were also isolated. Cell fractions were cultured for 24 hours, and PGE2 levels of supernatant were determined by radioimmunoassay. PGE2 production by LNMC was significantly decreased compared to tumor cells, TIMC, and PBMC (P = .0002). LNMC from metastatic lymph nodes produced significantly higher levels of PGE2 (P = .02) compared to nonmetastatic lymph nodes. Although T stage was not correlated with PGE2 production by TIMC or tumor cells, advanced N stage (N1-3) was associated with decreased PGE2 production by TIMC (P = .006). These results suggest that both tumor cells and TIMC are sources of PGE2 in tumor tissues of patients with SCCHN and that decreased PGE2 production by host inflammatory cells may have clinical significance in the development of cervical metastases.

Adult↗
PubMed1995

Laryngotracheal separation for intractable aspiration: a retrospective review of 34 patients.

LTS is an effective surgical procedure that results in the elimination of intractable aspiration. Most of these patients have major neurologic impairment due to progressive neurologic disease or devastating injury secondary to stroke, trauma, or surgery. The procedure can be performed in ill, debilitated patients and is well tolerated, even with local anesthesia. Few patients lose communicative speech, and some patients gain the ability to swallow following the procedure. LTS should be considered in the management of patients with intractable aspiration before performance of a tracheotomy because the procedure is technically easier to perform at this time and may reduce the risk of a wound-healing complication. Postoperative nursing care is decreased, and most patients can be discharged or transferred to a chronic-care facility within 2 to 3 weeks following the procedure.

Adult↗
PubMed1995

Tumor angiogenesis as a predictor of tumor aggressiveness and metastatic potential in squamous cell carcinoma of the head and neck.

Squamous cell carcinoma of the head and neck induces neovascularization to support tumor growth and facilitate the metastatic spread. Others have suggested that the density of microvessels within the tumor correlates with the neovascularization process and therefore with clinical behavior and outcome. To ascertain the value of the microvessel count as an independent prognostic indicator for squamous cel carcinoma of the head and neck, we studied the primary tumors of 44 patients. Histological slides were stained for factor VIII and the individual microvessels were counted on a 200 x field (0.49 mm). No statistically significant difference was found between the microvessel counts of tumors that metastasize or recur locally, as compared with tumors that did not. The possibility of a beta-error due to the small number of cases mandates a larger possibly multi-institutional, study to better ascertain the significance of a microvessel count as an independent prognostic indicator.

Carcinoma, Squamous Cell↗
PubMed1994

In vitro urokinase type plasminogen activator levels and total plasminogen activator activity in squamous cell carcinomas of the head and neck.

OBJECTIVE: Determine total plasminogen activator (PA) activity and urokinase-type plasminogen activator (u-PA) levels in cell-free supernatants derived from primary and metastatic squamous cell carcinoma of the head and neck. DESIGN: Plasminogen activator activity was measured by spectrophotometric assay with chromogenic substrate Val-Leu-Lys-para-nitroanilide. Urokinase-type plasminogen activator levels were measured with enzyme-linked immunosorbent assay technique. RESULTS: Fourteen established squamous cell carcinoma lines from patients with head and neck cancer were assayed for both total PA activity and u-PA levels at 24 to 48 hours of incubation. Compared with control and fibroblast-conditioned media, cell lines established from squamous cell carcinoma of the head and neck had significantly (P < .005) higher levels of both total PA activity and u-PA levels. Linear regression analysis showed a positive correlation (r = .65, P = .007) between total PA activity and u-PA levels. CONCLUSIONS: Squamous cell carcinomas of the head and neck are able to activate plasminogen and produce u-PA in vitro. The production of PA by squamous cell carcinomas of the head and neck may play an important role in the biology of invasion and metastasis.

Carcinoma, Squamous Cell↗
PubMed1994

Role of skull base surgery for local control of sarcoma of the nasal cavity and paranasal sinuses.

Sarcomas of the nose and paranasal sinuses are rare neoplasms and comprise less than 1% of the malignancies arising in the sinonasal tract. From 1977 to 1989, we had the opportunity to treat 15 patients presenting with these tumors at The Eye & Ear Institute of the University of Pittsburgh. The clinical charts of these patients were reviewed retrospectively for demographic data, characteristics of disease, treatment considerations and clinical outcome. Data were also analyzed with special attention to the role of skull base surgery for the local control of tumors. Seven patients underwent cranial base surgery as part of their original therapy. Two of these patients are alive with no evidence of disease, one patient died of other causes, and four are dead of disease. Two patients died with local disease. Although not statistically significant due to the small number of patients, these data suggest that cranial base surgery can improve the local control of sarcomas of the sinonasal tract that approach or invade the skull base.

Adolescent↗
PubMed1994

Arachidonic acid metabolites in saliva of patients with squamous cell carcinoma of the head and neck.

Alterations in the production of arachidonic acid metabolites by squamous epithelium of the upper aerodigestive tract may play a role in the pathogenesis of squamous cell carcinoma of the head and neck. The levels of cyclooxygenase and lipoxygenase metabolites of arachidonic acid metabolism were measured by radioimmunoassay in the saliva of 51 patients with squamous cell carcinoma of the head and neck and compared with a control group of 27 patients with no history of cancer. Levels of leukotriene B4 were significantly increased in cancer patients (p = 0.02), whereas there were no significant differences in levels of prostaglandin E2 or 15-hydroxy-eicosatetranoic acid. Levels of metabolites did not correlate with a history of tobacco use and did not change in a consistent manner after surgery. The significance of arachidonic acid metabolites in the saliva of patients with squamous cell carcinoma of the head and neck is unknown.

Adult↗