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Biomedical subjects

C H Snyderman

Publications and source records attributed to C H Snyderman.

At least 55 records · Page 3Linked to original sources
PubMed1994

Phase Ib trial of the effect of peritumoral and intranodal injections of interleukin-2 in patients with advanced squamous cell carcinoma of the head and neck: an Eastern Cooperative Oncology Group trial.

Thirty-six patients with unresectable squamous cell carcinoma of the head and neck were entered into a phase Ib trial evaluating the toxicity, maximally tolerated dose (MTD), and immunomodulating effects of locally administered interleukin-2 (IL-2). Patients received daily IL-2 injected perilesionally in divided doses in each of four quadrants and bilaterally into the superior jugular lymph nodes. The dose of IL-2 began at 200 U/day and was escalated to 4 x 10(6) U/day in groups of six patients. Overall, regionally administered IL-2 was well tolerated. The most frequently encountered toxicities were fever, hepatotoxicity, and hypotension. Dose-limiting toxicity was encountered at 4 x 10(6) U. Of the 36 patients treated, 2 partial responses were noted at 2,000 and 4 x 10(6) U. We conclude that regionally administered IL-2 is well tolerated in patients with head and neck cancer and that the MTD is 2 x 10(6) U/day, similar to what has been reported with systemically administered IL-2. Although the overall response rate was low, it may be improved with prolonged administration of IL-2 or by combining it with other biologic or cytotoxic agents.

Adult↗
PubMed1994

Thrombosed aneurysm of the cervical carotid artery: avoiding a retrospective diagnosis.

Two patients with neck masses were evaluated, one with computed tomography (CT) and the other with magnetic resonance (MR) imaging. Each mass was correctly identified within the carotid sheath. The correct diagnosis-thrombosed cervical carotid aneurysm--was not considered, necessitating unexpected repair of the aneurysm or artery. Although rare, aneurysm of the cervical carotid artery should be considered in the differential diagnosis of a carotid sheath mass between the jugular vein and carotid artery. Peripheral calcification or enhancement on CT scans and a peripheral signal void on MR images are especially suggestive of the diagnosis.

Aged↗
PubMed1994

Computer-assisted frontal sinusotomy.

An osteoplastic frontal sinus flap with flat obliteration is the "gold" standard for the management of chronic frontal sinus inflammatory disease caused by obstruction of the nasofrontal duct. Frontal sinusotomy, with an osteoplastic technique, call for osteotomies, guided by a template obtained from a Caldwell radiographic view taken at a distance of 6 feet. The reliability of the template depends on the position of the patient, distance at which the radiograph is taken, penetration of the x-rays, and other technical aspects. Therefore the template is a potential source of error. We present the use of a computer-assisted frontal sinusotomy as a method to corroborate the shape and margins of the frontal sinus in six patients undergoing obliterative frontal sinus surgery. In our hands, this technique has proved more reliable than the radiographic template to corroborate the positioning of the osteotomies.

Ethmoid Sinus↗
PubMed1994

Comparison of in vivo and in vitro prostaglandin E2 production by squamous cell carcinoma of the head and neck.

Prostaglandin E2 has been identified as an immunosuppressive factor in patients with squamous cell carcinoma of the head and neck. Spontaneous prostaglandin E2 production by 21 cancer cell lines, which were obtained from 17 patients with squamous cell carcinoma of the head and neck, was determined by radioimmunoassay. In comparison with normal keratinocyte cultures, prostaglandin E2 production by cancer cell lines was significantly decreased (p < 0.0001). Prostaglandin E2 levels demonstrated no correlation to the site, stage, or histopathologic differentiation of the tumor. In a separate group of 17 patients with squamous cell carcinoma of the head and neck, tumor cells were isolated from fresh tumor specimens, and 24-hour PGE2 production in vitro was assayed. No correlation was found with tumor site, stage, or 2-year disease-free survival. Although prostaglandin E2 may have biologic significance in vivo in patients with squamous cell carcinoma of the head and neck, these findings suggest that measurements of tumor cell-derived prostaglandin E2 are not predictive of biologic behavior.

Aged↗
PubMed1994

Hydroxyapatite cement: a new method for achieving watertight closure in transtemporal surgery.

Transtemporal approaches to the petrous apex and CP angle are standard procedures in the armamentarium of the neurotologist. In the majority of these cases, it is not possible to achieve a watertight suture closure of the dura following the procedure. Subsequently, cerebrospinal fluid leakage and potential meningitis are among the most troublesome complications for both patient and surgeon. Recent use of calcium phosphate cement (hydroxyapatite [HA]) has proved efficacious in animal studies and is now being used to close cranial defects in several medical centers, as part of an FDA-IDE study in human subjects. The use of this material is described in 11 neurotologic procedures. It is believed that hydroxyapatite cement (HAC) will become a standard tool in the management of cranial base and temporal bone defects following surgery.

Adult↗
PubMed1994

Excision of petroclival tumors by a total petrosectomy approach.

The surgical removal of intradural petroclival tumors of any size is demanding because of the restricted surgical exposure and relation of the tumor with the brain stem, cranial nerves, and vertebrobasilar artery and branches. When petroclival tumors are large or giant sized and involve multiple areas of the clivus, adequate surgical exposure is difficult to achieve, yet is critical for safe tumor removal. In 17 patients with extensive petroclival tumors, total removal of the petrous bone was performed to gain a wide and shallow surgical exposure. This report details the intraoperative and postoperative complications, cranial nerve status, pre- and postoperative disability scores, and extent of tumor resection in these 17 patients. Deterioration of facial nerve function was the most common new cranial nerve injury following surgery. Three patients suffered major neurologic complications; six other patients suffered significant but temporary neurologic complications. Gross total tumor resection was accomplished in 9 of 17 patients, and most patients (15/17) maintained or improved their disability status. Tumor residual was related to cavernous sinus involvement, vascular encasement, or brainstem pial invasion. Total petrosectomy is an intensive and complex approach with inherent morbidity and thus should be reserved for extensive petroclival tumors that cannot be removed using less complicated approaches.

Adolescent↗
PubMed1993

Chordomas and chondrosarcomas involving the cavernous sinus: review of surgical treatment and outcome in 31 patients.

During the last 9 years, 31 patients with chordomas (20 cases) and chondrosarcomas (11 cases) involving the cavernous sinus have been treated using an aggressive surgical approach. On the basis of postoperative magnetic resonance imaging (MRI), 17 patients were considered to have undergone total removal, whereas in the remaining 14 cases the tumor was either subtotally or partially removed. Surgical complications were most commonly encountered among patients who had undergone previous operations. One patient died 3 months after the operation as a result of pulmonary embolism. Significant disability occurred in one patient because of thalamic perforator occlusion and hemorrhage. Recovery of extraocular muscle function was gratifying, and correlated to the preoperative functional level. After a median follow-up of 24 months, three recurrences (21%) occurred among the 14 patients who had undergone incomplete removal. No recurrence was observed among the 17 patients with total resection. This experience shows that gross radical removal of chordomas and chondrosarcomas involving the cavernous sinus can be accomplished with an acceptable surgical morbidity. However, much longer follow-up will be required to determine whether such aggressive surgical treatment results in cure or long-term control of these neoplasms.

Adolescent↗
PubMed1993

Meta-analysis of outcome in anterior skull base resection for squamous cell and undifferentiated carcinoma.

Multiple reports now demonstrate the technical feasibility of combined intra- and extracranial procedures for the excision of malignancy involving the anterior skull base-Anatomic proximity to vital structures in this region often precludes en bloc resection, however, and margins are often measured in millimeters. Nevertheless, multiple cases of prolonged survival following craniofacial excision of high-grade malignancies have been reported. These are usually included in larger series that encompass tumors of various histologic characteristics and grade. A meta-analysis of the reported outcome of craniofacial resection for squamous cell and undifferentiated carcinoma was performed. Ninety-six articles on craniofacial resection were reviewed and a total of 425 patients who had undergone craniofacial resection were identified in 30 of these. Of 89 patients with squamous cell carcinoma in whom follow-up data were available from seven larger series, the disease-free survival at 2 or greater years was 64%. Forty-one patients with undifferentiated carcinoma were identified who had undergone surgical excision, and 45% were disease-free at 2 or greater years (range, 2 to 24 years). This meta-analysis suggests that high-grade carcinoma involving the anterior cranial base is amenable to surgical excision with acceptable disease-free survival in selected patients at 2 years.

Journal Article↗
PubMed1993

Angiogenesis induced by head and neck squamous cell carcinoma xenografts in the chick embryo chorioallantoic membrane model.

The angiogenic potential of head and neck tumors compared to nonneoplastic control tissues was investigated by using the chick embryo chorioallantoic membrane (CAM) as a bioassay for angiogenesis. Eighty tumor specimens from 10 patients with squamous cell carcinoma of the head and neck were grafted onto the CAM of 7-day chick embryos. The presence of tumor in the original explant was confirmed histologically. Forty-four embryos (55%) survived and were evaluated histologically at day 17. Tumors were growing on or invading the CAM mesoderm in 30 of 44 embryos (68%). Before harvesting of the membranes, the tumors and surrounding blood vessels were photographed, and the angiogenic responses were graded by a panel of blinded observers. Tumor explants elicited a significantly greater angiogenic response than nontumor controls (p = .01). We conclude that head and neck squamous cell carcinomas can induce an angiogenic response in vivo, presumably secondary to the production of an unidentified angiogenic factor, and that the chick embryo CAM is an effective model for quantifying angiogenesis induced by head and neck tumors.

Allantois↗
PubMed1992

Postoperative wound infection. A poor prognostic sign for patients with head and neck cancer.

BACKGROUND: The development of a wound infection has been identified as a favorable prognostic factor after oncologic surgical procedures. METHODS: The authors retrospectively studied the relationship between postoperative wound infection, local/regional tumor recurrence, and survival rates in 134 patients undergoing therapeutic surgical resection for squamous cell carcinoma of the head and neck (SCCHN). RESULTS: The median age was 61 years (range, 25-87 years) with most (75%) patients having advanced disease (Stage III or IV). Patients without evidence of recurrent disease were followed up for a median time of 34 months (range, 24-68 months). Twenty-nine (22%) had local or regional bacterial infections develop postoperatively. Recurrence rates were increased (P = 0.008) in patients with postoperative wound infections compared with patients who had distant infections, e.g., pneumonia or urinary tract infection, or no infection. Disease-free survival also was adversely affected (P = 0.04) in this group. Both advanced tumor stage and postoperative wound infections were independently associated with decreased survival, with odds ratios of 2:3 and 2:4, respectively. CONCLUSIONS: These data contrast with other reports in the literature of a beneficial effect of postoperative wound infection on outcome. These findings suggest a possible relationship between local/regional immune function and postoperative infection in patients with SCCHN:

Adult↗
PubMed1992

Experimental tracheal replacement using a revascularized jejunal autograft with an implantable Dacron mesh tube.

Defects comprising more than 50% of the trachea cannot be reliably reconstructed by any current technique or prosthesis. A composite tracheal replacement implant consisting of a Dacron-urethane mesh tube and revascularized jejunal autograft was applied to this problem. This composite implant was used to replace 7 to 10 cm of trachea in eight dogs. The implant was sewn to the outside (serosal surface) of the jejunum to provide permanent structural support to the autograft, and an intraluminal silicone tube was placed inside the jejunal segment and left for 4 weeks following reconstruction. Six of eight animals survived the predetermined time periods and were killed painlessly in groups of two animals at 1, 2, and 6 months after removal of the intraluminal silicone tube. Postoperative intubation, ventilation, or tracheostomy was not necessary. Excessive secretions were not seen in any of the animals, and a fair to good performance status was maintained until death in all but one animal. Histologic examination revealed slight thinning of the jejunal mucosa, with no change in the jejunal muscularis. These data suggest that with further refinement this composite implant may be a viable reconstructive option in humans.

Animals↗
PubMed1991

Functional and phenotypic analysis of lymphocytes in head and neck cancer.

We compared the phenotype and antitumor effector function of lymphocytes obtained from tumor tissues, lymph nodes, and the peripheral blood of patients with head and neck cancer. Freshly isolated tumor-infiltrating lymphocytes were deficient in CD4+ T cells in comparison with lymph node lymphocytes (LNL) and peripheral blood lymphocytes. A significantly higher CD4/CD8 ratio observed in LNL vs tumor-infiltrating lymphocytes and peripheral blood lymphocytes was attributable to both a significant enrichment in CD4+ T cells as well as a decrease in CD8+ T cells. The percentage of natural killer cells (CD3-CD56+) was uniformly low in both tumor-infiltrating lymphocytes and LNL. In patients with cervical metastases, LNL contained an increased proportion of CD16+ cells. Tumor-involved lymph nodes were not enriched in the CD8+C11b+ subset of T "suppressor" lymphocytes compared with uninvolved lymph nodes. Also, tumor-involved lymph nodes had significantly fewer CD4+ T cells than did uninvolved lymph nodes. In comparison with peripheral blood lymphocytes, freshly isolated tumor-infiltrating lymphocytes and LNL were depleted of cytotoxic effector cells, as indicated by low or absent cytotoxic activity against tumor cell targets. The ability to generate lymphokine-activated killer cells was significantly reduced in LNL in comparison with peripheral blood lymphocytes. In patients with head and neck cancer, depressed local and regional antitumor responses are associated with a deficiency of functional cytotoxic effector cells rather than an increase in suppressor T lymphocytes.

Adult↗
PubMed1991

Computerized tomography and magnetic resonance imaging following cranial base surgery.

The computed tomography scans and magnetic resonance imaging films of 57 patients who underwent anterior or anterolateral cranial base surgery from January 1987 to August 1989 were retrospectively reviewed to ascertain the significance of early and late postoperative intracranial imaging changes. Extra-axial changes (air, blood, cerebrospinal fluid collection) were found in 96% of patients; axial changes (brain edema, contusion) were seen in 30% of patients in the first postoperative period (72 hours). Subsequently, extra-axial changes began to resolve but axial changes became more prevalent. After 6 months, only axial changes persisted (encephalomalacia). It was encouraging to find a low correlation of imaging abnormalities with clinically significant findings.

Encephalomalacia↗
PubMed1990

Local adoptive immunotherapy of human head and neck cancer xenografts in nude mice with lymphokine-activated killer cells and interleukin 2.

The efficacy of local adoptive immunotherapy with human lymphokine-activated killer cells and recombinant interleukin 2 (rIL-2) in growth inhibition of established squamous cell carcinoma of the head and neck (SCCHN) was evaluated in a nude mouse model. The model of xenografted SCCHN was established by s.c. injections of in vitro maintained tumor cells (2-10 x 10(6) cells/mouse) into the flank of splenectomized animals pretreated with cyclophosphamide (200 mg/kg). The SCCHN line used was tumorigenic in 95% of the appropriately conditioned nude mice. Inhibition of tumor growth by locally administered effector cells was the end point of the study, since the tumors did not metastasize within 6 weeks of tumor challenge. Either i.p. or local administration of rIL-2 alone (1000 units/day) to the tumor site daily for 2 weeks resulted in a significant inhibition of tumor growth. In the absence of detectable natural killer activity in these mice, a modest dose of rIL-2 had a direct antitumor effect on SCCHN cells in vivo. In addition, complete inhibition of tumor growth was achieved with 3 times weekly injections of 5-10 x 10(6) lymphokine-activated killer cells delivered to the tumor site and 1000 units of rIL-2 administered locally every day for 2 weeks. Our data indicate that local or systemic immunotherapy with rIL-2 alone or local adoptive immunotherapy with an adequate dose of lymphokine-activated killer cells plus rIL-2 may be effective in preventing the growth of established SCCHN tumors in vivo.

Animals↗
PubMed1990

Anterior cranial base reconstruction: role of galeal and pericranial flaps.

Reconstruction of surgical defects in 30 patients undergoing surgery of the anterior cranial base was performed using pericranial, galeopericranial, and galeal scalp flaps. Twenty-seven patients had resection of neoplasms, the majority of which were malignant. Fifty-seven percent of patients received prior therapy consisting of surgery and/or radiotherapy. Adequate healing of the cranial base was noted in all cases without persistent cerebrospinal fluid leaks, meningitis, or brain herniation. Mucosalization of the intranasal surface was noted. No skin grafts were used. At a median follow-up of 13 months, 67% of patients were alive with no evidence of disease. The pericranial, galeopericranial, and galeal flaps are highly reliable, versatile, and well suited for reconstruction of the anterior cranial base.

Adolescent↗
PubMed1990

Malignant skull base tumors.

A multidisciplinary approach to the treatment of malignant cranial base tumors has resulted in improved resections with less morbidity and a greater potential for cure. An improved understanding of the complex anatomy has allowed the development of new surgical approaches and improved methods of reconstruction. The authors' experience with the treatment of malignant neoplasms of the cranial base is reviewed, with emphasis on biologic behavior of this diverse group of neoplasms.

Craniotomy↗