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Biomedical subjects

R H Maisel

Publications and source records attributed to R H Maisel.

At least 19 recordsLinked to original sources
PubMed1997

Terazosin blockade of nicotine-induced skin flap necrosis in the rat.

OBJECTIVE: To examine the ability of terazosin hydrochloride to block the decrease in skin flap survival induced by nicotine. DESIGN: A randomized controlled animal trial. SUBJECTS: Ninety-two male Sprague-Dawley rats were randomized to 1 of 5 groups: double-placebo control (n = 15), nicotine opposed by oral placebo (n = 26), nicotine opposed by subcutaneous placebo (n = 16), nicotine opposed by oral terazosin (n = 21), and nicotine opposed by subcutaneous terazosin (n = 14). INTERVENTION: All rats received 1 mg of nicotine twice daily via subcutaneous injection except for those in the double-placebo control group, which received saline injections twice daily, for the 6-week study. The terazosin treatment groups received 1.5 mg of terazosin hydrochloride twice daily either orally or subcutaneously while the rest received a saline solution placebo either orally or subcutaneously for the last 4 weeks of the study. At the end of the fifth week, a 4 x 10-cm, caudally based, dorsal random-pattern flap was elevated and repositioned. The outcome was measured in percentage area of flap survival. RESULTS: The mean (+/-SEM) area of flap survival for the double-placebo control group was 79% +/- 2%. Nicotine opposed by oral placebo or subcutaneous placebo produced a significant decrease in survival areas (mean [+/-SEM] area, 73% +/- 2% and 74% +/- 2%, respectively). Nicotine opposed by oral terazosin produced a mean (+/-SEM) survival area of 81% +/- 2%, which was significantly better than the nicotine opposed by placebo group and similar to the control group (P = .02). CONCLUSION: Use of oral terazosin elevated flap survival rates to control levels in nicotine-treated rats.

Adrenergic alpha-Antagonists↗
PubMed1996

Pediatric fiberoptic laser rigid bronchoscopy.

Use of the fiberoptic laser for treatment of tracheobronchial lesions in the adult is well established. However, there is a paucity of experience with the fiberoptic laser in the pediatric airway. Tracheal obstruction caused by granulation tissue or stenosis, as is often seen in children, may be effectively treated with this approach. This article documents the successful use as well as the technologic advantage of the flexible fiberoptic laser systems, primarily the potassium titanyl phosphate (KTP) laser, combined with standard pediatric rigid bronchoscopic equipment in 73 procedures involving 52 children (43 children younger than five years. with an average age of 21 months). Visualization was excellent, assisted or spontaneous ventilation was well maintained, and complications were few.

Adolescent↗
PubMed1994

The effects of the inhalational anesthetic agent combination, isoflurane-nitrous oxide, on survival in a pig random skin flap model.

Using a dorsally based, random skin flap model in 14 swine, the influence on skin flap survival of isoflurane used with nitrous oxide as maintenance anesthetic agents was examined. The mean area of skin flap survival was 54.9% for the experimental group compared with 28.6% in the control group. Arterial blood gas content (PO2, PCO2, and HCO3-), respiratory rate, acid-base balance, blood pressure level, pulse rate, and temperature were monitored. Improved survival of the isoflurane-nitrous oxide group was independent of these parameters. These data support the findings of a previous study that isoflurane positively affects random skin flap survival in a swine model. Furthermore, the addition of nitrous oxide partially reduces isoflurane's beneficial effects.

Anesthesia, Inhalation↗
PubMed1994

Cervical necrotizing fasciitis.

Nine cases of cervical necrotizing faciitis are presented. Five were odontogenic, three were pharyngeal in origin, and one developed from a soft-tissue spider bite. The bacteriology represented a polyculture of gram-positive, gram-negative, as well as anaerobic bacteria, and initial medical treatment by third-generation cephalosporin and metronidazole or clindamycin was successful and is recommended. Airway control is necessary early, as is a wide exploration of the fascial spaces of the neck, with frequent reexploration in either the operating room or at the bedside to evaluate the effects of treatment and to prevent further progression of the disease. Intensive medical support is crucial, and hyperbaric oxygen is advised for patients who are deteriorating under standard therapy.

Adult↗
PubMed1992

The effects of inhalation anesthetic agents on survival in a pig random skin flap model.

In recent years a myriad of studies have been performed investigating the effects on flap survival of various pharmacologic agents. One class of agents, however, that has received relatively little attention is the inhalational anesthetics. Yet, they are widely used during reconstructive efforts using skin flaps and they possess several pharmacologic properties shown to affect flap survival. Using a dorsally based random skin flap model in 28 swine, the influence of nitrous oxide and isoflurane on skin flap survival was examined. The mean area of skin flap survival in the isoflurane, nitrous oxide, euoxemic control, and hyperoxygenated control groups was 79.4%, 29.7%, 42.0%, and 28.6%, respectively. A significant improvement in flap viability was seen only in the group using isoflurane as the anesthetic agent. Arterial blood gas content (PO2, PCO2, and HCO3), respiratory rate, acid-base balance, blood pressure, pulse, and temperature were monitored. Improved survival of the isoflurane group was independent of these parameters. These data suggest that the choice of anesthetic agent may effect random skin flap survival with isoflurane providing the greatest benefit of the agents tested in this model.

Anesthesia, Inhalation↗
PubMed1992

Postoperative radiation-associated changes in free jejunal autografts.

Free jejunal autografts are a preferred method of pharyngoesophageal reconstruction. Ten adult mongrel dogs underwent free jejunal transplantations to the neck, five being controls and five receiving a 55-Gy equivalent dose of radiation after 3 weeks. Histologic changes 10 months after radiotherapy included simplified and blunted villi with normal architecture loss; fibrous replacement of the lymphatics and microvasculature in the intravillous space; goblet cell increase; significant increase in lamina propria thickness and muscularis mucosa fibrous plates; focal destruction and replacement of muscle layers with fibrosis; gross hypertrophy of the myenteric plexus with increased fibrous tissue about the hypertrophied neural tissue; and significant perivascular fibrosis. Controls demonstrated only minimal changes. These adverse delayed effects of irradiation on revascularized jejunal autografts should be considered in planning the method of pharyngoesophageal reconstruction as well as timing of adjuvant radiotherapy.

Animals↗
PubMed1992

Angiogenic growth factors: their effects and potential in soft tissue wound healing.

Since their discovery 30 years ago, angiogenic growth factors have been demonstrated to stimulate neovascularization in vitro and in animal studies. Over the last decade, knowledge gained in the field of angiogenic growth factors has grown immensely. These angiogenic growth factors exist in four major families: fibroblast growth factor (FGF), transforming growth factor beta (TGF-beta), platelet-derived growth factor (PDGF), and epidermal growth factor (EGF). Each has the ability to induce soft tissue vascularization in microgram quantities. In animal models, FGF, TGF-beta, PDGF, and EGF have been shown to enhance soft tissue wound healing. In human clinical trials, EGF, and a mixture of PDGFs have been demonstrated to accelerate epidermal regeneration in cutaneous wounds. These factors have considerable therapeutic potential in the areas of soft tissue wound healing and otolaryngology. This article reviews important aspects of angiogenic growth factors and discusses their future potential in soft tissue wound healing.

Animals↗
PubMed1992

Uvulopalatopharyngoplasty for obstructive sleep apnea: a community's experience.

Uvulopalatopharyngoplasty (UPPP) has become an accepted method for treating obstructive sleep apnea (OSA), with a reported success rate as high as 77%, depending upon inclusionary and outcome criteria. The authors reviewed the records of 90 patients with moderately severe OSA (apnea plus hypopnea index [AHI] greater than 20) who underwent UPPP at either a private community or an academic hospital. Forty percent of patients experienced more than a 50% reduction in their AHI with UPPP. Only 22 (24%) of the patients had a postoperative AHI less than 50% of the preoperative AHI and less than 20, i.e., met the authors' criteria for surgical success. The success rate for community otolaryngologists was no different than that achieved in the academic institution. When data from previously published reports were analyzed using these criteria for success, similar results were observed. This study suggests that the effectiveness of UPPP performed by the general otolaryngologic community is equivalent to that reported in the literature. However, more rigorous criteria must be applied to UPPP when evaluating its results and in counseling potential candidates for this procedure.

Adult↗
PubMed1992

Gross morphologic and functional effects of postoperative radiation on free jejunal autografts.

Twenty adult mongrel dogs underwent free jejunal transplants to the neck; 10 either died of or had to be sacrificed as a result of postoperative complications, 5 received a 55-Gy-equivalent dose of radiation after 3 weeks, and 5 were followed as controls. Serial manometric and endoscopic evaluations were performed over a 9-month period. Progressive deterioration of the quality and amplitude of peristalsis of the jejunal autografts was observed only in the radiated group. In addition, all dogs in the radiated group developed severe jejunal circumferential constriction and stricture formation. These delayed effects of irradiation on revascularized jejunal autografts should be considered in planning the method of pharyngoesophageal reconstruction as well as the timing of adjuvant radiotherapy.

Anastomosis, Surgical↗
PubMed1991

Invasive Chrysosporium infection of the nose and paranasal sinuses in an immunocompromised host.

Aggressive fungal rhinosinusitis with Chrysosporium sp. occurred in a patient with acute lymphocytic leukemia. The infecting organism is an exceedingly rare human pathogen. Usually, human chrysosporial infections are mild and unmarked by symptoms. Most case reports appear in the pathology literature and describe the incidental finding of adiaspores in the pulmonary parenchyma at autopsy. Clinical disease from active growth of chrysosporial mycelia in human tissues has been noted on a porcine aortic valve prosthesis and in a tibial abscess. Hyphal elements were not recovered from any other body parts of these patients. Histopathologic and microbiologic studies permitted the identification of this rarely encountered organism. Our patient experienced systemic spread of Chrysosporium organisms. Treatment of this pathogen is the same as for other opportunistic fungal infections.

Adolescent↗
PubMed1990

Inhibition of endogenous superoxide dismutase with diethyldithiocarbamate in acute island skin flaps.

Oxygen free radicals have been implicated in postischemic tissue damage in a variety of experimental models including the island skin flap. Previous studies have demonstrated that supplementing animals with exogenous superoxide dismutase (SOD), a free radical scavenger, improves tissue survival in island flaps. No studies to our knowledge have attempted to inhibit endogenous SOD in a skin flap model. In this experiment 20 control rats demonstrated a 12.00% flap necrosis 7 days after a modified ventral island skin flap was raised. A second group of 20 rats were supplemented with exogenous SOD (50,000 U/kg 30 minutes preoperatively and 12 hours postoperatively) and demonstrated a statistically significant decreased flap necrosis of 5.28%. A third group of 20 rats received diethyldithiocarbamate (DDC, 0.5 gm/kg 12 hours preoperatively), an agent previously shown to inhibit SOD, and demonstrated a statistically significant increased flap necrosis of 19.77%. In a final group of 20 rats the effect of DDC was overcome by supplementation with exogenous SOD, obtaining a flap necrosis of 8.35%. Our results add further support to the importance of SOD and oxygen free radicals in postischemic tissue damage by demonstrating increased tissue necrosis with inhibition of endogenous SOD. This suggests that there is a baseline degree of SOD activity in ischemic areas working to preserve tissue. It appears that the copper-containing species of SOD found primarily in the cytoplasm plays a pivotal role in preservation of postischemic tissue.

Animals↗
PubMed1989

Postirradiation sarcomas of the head and neck.

We discuss four cases of postirradiation sarcomas of the head and neck. Two cases were metachronous sarcomas that appeared after operation and irradiation for primary sarcomas, 1 case was a mandibular malignant fibrous histiocytoma that developed on the opposite side of the jaw from a malignant histiocytic neoplasm that was irradiated 8 years previously, and 1 case was a laryngeal tumor that appeared 5 years after combined operative and radiation therapy for a laryngeal squamous carcinoma. Immunohistochemical studies more precisely defined and classified these tumors, and assisted in determining a therapeutic protocol. The therapy for postirradiation sarcomas includes extirpative operation when possible, but the role of chemotherapy is uncertain. The aggressive behavior of these neoplasms was attested to by the death of three patients within 18 months of their operations.

Adult↗
PubMed1988

Three-dimensional CT reconstruction in midfacial surgery.

Correct preoperative planning is an essential aspect of any surgical procedure and it is equally important when midfacial reconstruction is contemplated. Conventional methods include standard radiographic views, plain tomography, photography, and computerized tomography. All of these methods produce a two-dimensional image of the patient. Three-dimensional computerized tomographic reconstruction allows the surgeon to visualize the entire facial skeletal deformity. The three-dimensional image produced also allows comparison of the deformity to surrounding normal structures, and thus makes the correction of facial asymmetrics more precise. This new modality is particularly useful in the preoperative planning for patients with zygomaticomaxillary defects that result from either trauma or maxillectomy. Illustrative examples of patients in whom autogenous bone graft zygomaticomaxillary reconstruction was performed, after trauma and subsequent to subtotal maxillectomy, are presented. The amount and exact placement of the grafts was determined preoperatively from the analysis of the three-dimensional CT reconstruction, and the surgical planning was thereby simplified.

Adult↗
PubMed1988

Chapter 2. Anatomy of the facial nerve.

This issue of the American Journal of Otology includes the second of a series of articles on facial nerve disorders, which collectively are known as the "Facial Nerve Manual." In the early 1980s, Dr. Mark May chaired the AAO-HNS Facial Nerve Committee and organized the Facial Nerve Study Group. One of the tasks he initiated was the creation of a Facial Nerve Manual, assigned to a small group of clinicians at the COSM Meeting in the Spring of 1984. The purpose of this work was to disseminate practical information on management of selected facial nerve problems, one of the primary charges of the committee. Work began slowly but surely. During Dr. Gale Gardner's tenure as committee chairman, manuscripts were reviewed and edited by Dr. Nels Olson, and the American Journal of Otology agreed to publish the manual. Perhaps more than anyone else, Dr. Olson worked tirelessly to create a finished product of consistent style and content. Of course, even since the original writing and editing, controversial topics continue to change; for example, the author of "Prognostic Testing" now feels that electroneurography is the only sufficiently sensitive prognostic test to determine the need for possible surgery for Bell's palsy. As each "chapter" is published individually over the next year, other concepts may change, and the reader is encouraged to explore these issues in more depth. Drs. May, Gardner, Olson and the individual authors are congratulated for their efforts. The Committee sincerely thanks the American Journal of Otology for supporting this work.

Facial Nerve↗
PubMed1987

Oral cavity reconstruction using the free radial forearm flap.

While a number of flaps are available that can "plug the hole" created by the resection of an oral cavity malignancy, the final functional and cosmetic result is often far from satisfactory. The ideal flap for this area should provide a one-stage, reliable reconstruction (regardless of previous surgery or irradiation) with the options of thin pliable skin and/or vascularized bone. Donor-site morbidity must be acceptable. In our experience, the free radial forearm flap best approaches these ideals. Unfortunately, it has received relatively little attention in the otolaryngology literature. The results of using 15 of these flaps to reconstruct 14 oral cavity defects are reported here. Despite the fact that most of the reconstructions were performed in older patients who had undergone irradiation (nine of 14) and previous surgical treatment (ten of 14), there were no flap failures. Hospital stays were short (less than two weeks), cosmetic results were good, and all but one patient had resumed oral intake by the time of hospital discharge. The specific applications and limitations of this flap are emphasized so that the reader can better understand its role in head and neck reconstructive surgery.

Adult↗
PubMed1987

Free jejunal autograft reconstruction of the pharyngoesophagus: review of a 10-year experience.

Seventeen patients underwent free jejunal autograft reconstruction of the pharyngoesophagus after ablative surgery for Stage III and IV squamous cell carcinoma of the cervical esophagus and hypopharynx. Postoperative complications included three perioperative deaths, three graft failures, six transient fistulas, and two early and one late fistula. The 5-year survival rate of patients with Stage III and IV hypopharyngeal carcinoma was 20% (one of five). The 4-year survival rate for patients with cervical esophageal carcinoma was 33% (one of three). This method of reconstruction is advocated as a reliable palliative procedure for patients with a dismal long-term survival.

Adult↗