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Biomedical subjects

C W Vaughan

Publications and source records attributed to C W Vaughan.

At least 19 recordsLinked to original sources
PubMed1992

Hypogastric nerve section reveals a role for both afferent and efferent fibres in the feline continence process.

The role of the hypogastric afferent and efferent innervation in the process of urine storage during natural rate filling was examined in the pentobarbitone anaesthetized cat. The observed changes in bladder pressure following hypogastric nerve section demonstrated the presence of baseline sympatho-inhibitory and phasic sympatho-excitatory influences for a significant portion of each distension, which proceeded to a volume just over halfway through the continence process. A reduction in bladder wall compliance at the end of the distensions provided evidence for a net sympatho-inhibitory influence in the second half of the continence phase. Hypogastric nerve section also resulted in a reduction in the reflex increase in hypogastric efferent nerve activity, measured in-continuity. This suggested that hypogastric afferent fibres made a significant contribution to the regulation of sympathetic hypogastric nerve activity during natural rate filling.

Animals↗
PubMed1992

Role of sympathetic innervation in the feline continence process under natural filling conditions.

1. The effect of the sympathetic innervation on the bladder detrusor muscle was assessed in pentobarbitone-anesthetized cats by measuring the changes in bladder wall tension that occurred during sympathetic ganglion blockade after filling the bladder at a natural rate. 2. At a point 60% of the way through the continence process, systemic sympathetic blockade was produced by intravenous trimethaphan, and selective blockade of postganglionic hypogastric nerve activity was produced by application of trimethaphan to the exposed inferior mesenteric ganglia. The level of blockade was monitored with an in-continuity hypogastric nerve recording. 3. During both systemic and selective ganglion blockade, there was an increase in baseline transmural bladder pressure and a decrease in the amplitude of nonmicturating contractions. 4. Although there was no change in the mean level of transmural bladder pressure during either systemic or selective blockade, there was a significant increase in the mean level of bladder wall mechanoreceptor discharge, suggesting that before the blockade sympathoinhibitory effects were greater than sympathoexcitatory effects. 5. Measurement of bladder wall mechanoreceptor discharge before and during ganglion blockade revealed a net sympathoinhibitory influence on the level of bladder wall tension under natural filling conditions. These results confirm that the detrusor muscle of the feline bladder is under both sympathoinhibitory and sympathoexcitatory influences for a significant portion of the continence process.

Anesthesia↗
PubMed1991

Suprahyoid pharyngotomy for oropharynx cancer including the tongue base.

Suprahyoid pharyngotomy has been utilized as the standard approach to tongue base cancer not involving the larynx or mandible for the last 6 years at the Department of Veterans Affairs Medical Center, Boston, Mass. Review of 15 patients revealed that all had advanced disease (stage III and stage IV); 14 cases involved the tongue base, and one was on the posterior pharyngeal wall. By following the hyoepiglottic ligament, precise entry into the vallecula was routine. No injuries of vital neurovascular structures or compromised tumor margins were present; one tracheotomy was performed. Primary closure without the use of flaps was accomplished in 14 of 15 patients. No locoregional recurrences were found, with a median follow-up of 25 months. However, two patients died of another unrelated cancer, and two patients died of a myocardial infarction unrelated to their surgery. Suprahyoid pharyngotomy is a familiar approach often utilized during laryngectomy. In our experience, it provides excellent exposure of the oropharynx, can be combined with a transoral approach to avoid mandibulotomy without precluding this option, allows for simple reconstruction, and has a low complication rate.

Follow-Up Studies↗
PubMed1991

A model for multidisciplinary data collection for cervical metastasis.

A system for multidisciplinary data collection for metastatic neck disease is discussed. Information from 87 neck dissections and 3218 lymph nodes is reported to illustrate the strength of the model. Clinical (endoscopic) assessment under general anesthesia, surgical assessment during the neck dissection, and radiographic (computed tomographic scan) assessment were compared with the pathological evaluation. All disciplines stratified the necks by region and node size. This model provides an effective stratagem for multi-institutional studies.

Data Collection↗
PubMed1991

Larynx preservation using induction chemotherapy plus radiation therapy as an alternative to laryngectomy in advanced head and neck cancer. A long-term follow-up report.

Since 1977, we have used induction chemotherapy (CT) plus radiation therapy (RT) with curative intent in 35 advanced head and neck cancer (Ca) patients who otherwise would have required total laryngectomy. Fourteen patients had advanced Ca of the larynx or supraglottic larynx (SGL); 21 patients had Ca of the hypopharynx. In six patients the Ca was Stage III; in 26 patients it was Stage IV. Three patients had Stage II disease--2 with cancer of the pyriform sinus and one patient with Stage II SGL Ca who refused surgery. Chemotherapy consisted of platinum (P) + bleomycin in 18 patients until 1982, then P + fluorouracil in the next 17 patients. Total response rate was 77%--complete (CR) in 26% and partial (PR) in 51%. There were two toxic deaths. Surgery was limited to tracheostomy in 4 patients prior to CT and to radical neck dissection after CT in 4 others. Two patients required salvage laryngectomy at 11 and 31 months, respectively. One patient underwent partial laryngectomy with voice preservation. Thirty-two patients were evaluable for overall response after RT. Final disease-free status was achieved in 20/34. One long-term survivor was lost to follow-up (44 months) and 8 patients remained alive at 13+ to 109+ months. Median failure-free survival for all patients was no less than 24 months. Not counting 4 early deaths free of disease, 2-year local control using only chemotherapy plus radiation was 52% (16:31). Overall, 33 of 35 patients retained their voices. Sixteen patients (46%) have survived 2 years or longer. Survival of patients who achieved CR after induction chemotherapy was 48 months versus 14 months for those with less than a CR (p = 0.001). Patients with a hypopharyngeal primary had only a 33% 2-year local control rate with chemotherapy and radiation and a median survival of only 12 months versus 77% control and a minimum 39-month survival for those whose tumor arose in the larynx (p = 0.009). Induction chemotherapy plus radiation therapy is an effective strategy which can produce a high rate of larynx preservation, local control, and long-term survival in patients with advanced cancer of the larynx. Patients with hypopharyngeal primaries have a lesser rate of long-term survival and local control, despite similar overall response rates.

Aged↗
PubMed1991

Preepiglottic space invasion in "early" epiglottic cancer.

The tendency of epiglottic cancer to invade the preepiglottic space and the significance of this invasion was evaluated in 36 surgical specimens of epiglottic carcinoma originally staged T1 or T2. None of the 9 lesions originating above the hyoepiglottic ligament invaded the preepiglottic space. Twenty-four of the 27 (89%) lesions originating below the hyoepiglottic ligament showed invasion of the preepiglottic space and were clinically understaged. Of the 3 infrahyoid lesions showing no invasion of the preepiglottic space, 1 was a verrucous carcinoma and another was a mucoepidermoid carcinoma arising on the petiole. All other lesions were squamous cell carcinoma. In 12 of the 24 patients (50%) with preepiglottic space invasion, cervical node metastasis was present despite the preoperative staging of T1 or T2.

Carcinoma↗
PubMed1991

A rare cause of nasal obstruction: a solitary neurofibroma.

This case represents a peripheral nerve sheath tumor as a cause of nasal obstruction. Nerve sheath tumors are relatively uncommon; however, most otolaryngologists will encounter them. These tumors develop from cranial and spinal nerve roots and from peripheral nerves. In total, approximately 25% to 44% of nerve sheath tumors occur in the head and neck region. Although the most important are cranial nerve tumors--the majority being acoustic neuromas arising from the vestibular nerve--they may also develop in the nasal cavity.

Aged↗
PubMed1991

A submucosal true vocal fold infusion needle.

This simple, inexpensive device for submucosal true vocal fold saline infusion into Reinke's space improves the diagnosis and treatment of small vocal cord lesions and is a useful addition to our microlaryngoscopy instrumentation.

Equipment Design↗
PubMed1991

A precision technique for suprahyoid pharyngotomy.

This technique of suprahyoid pharyngotomy is very useful for excision of selected laryngeal and pharyngeal neoplasms. By identifying and following the hyoepiglottic ligament, precise entry into the pharynx is accomplished easily and rapidly at the median glossoepiglottic fold.

Epiglottis↗
PubMed1990

Endoscopic management of early supraglottic cancer.

An initial endoscopic surgical approach to early supraglottic cancer provides the surgeon with the ability to accurately stage these lesions, avoiding possible undertreatment while allowing for a valuable treatment option for those supraglottic cancers with histologically incontrovertibly superficial disease. Early invasion of the preepiglottic and paraglottic spaces can be determined accurately without altering or delaying any treatment option (open surgical excision, radiotherapy, or chemotherapy). The tendency of supraglottic cancers to transgress the natural foramina of the epiglottis is well established, and the concern about this depth of invasion is reflected by the 1977 revised staging criteria, which required assessment of the preepiglottic space (PES). Along with the microscope and the carbon dioxide laser, the adjustable supraglottiscope facilitates the determination of PES invasion and facilitates en bloc excision of superficial supraglottic cancers. The resulting morbidity typically is no different from that with routine direct endoscopy and biopsy.

Combined Modality Therapy↗
PubMed1990

Laser epiglottectomy: endoscopic technique and indications.

Endoscopic epiglottectomy (epiglottidectomy) may be performed with relative ease and minimal morbidity by using standard microlaryngoscopy techniques and the CO2 laser. Depending on the indications, the removal may be partial or complete. Indications for 51 epiglottectomies included treatment of supraglottic airway obstruction--30 cases; discovery of benign or malignant neoplasm (diagnosis and staging)--20 cases; treatment of malignant neoplasm--7 cases; glottic visualization--4 cases; and treatment of chronic inflammatory conditions--1 case. It is not unusual for a patient to have more than one indication for this procedure. Some epiglottic cancers invade the pre-epiglottic space. This crucial information may not be detectable by MRI or CT scanning techniques. Laser epiglottectomy provides a method to explore and perform a biopsy of the pre-epiglottic space and thereby stage these lesions accurately. There are no significant problems with postoperative alimentation, airway, or voice. Any form of primary or adjuvant therapy can be started without delay.

Airway Obstruction↗
PubMed1990

The adjustable supraglottiscope.

Transoral surgery in the supraglottic larynx is facilitated by the use of a new instrument, an adjustable supraglottiscope. Conventional adjustable laryngoscopes are not designed for supraglottic surgery and are therefore difficult to use in this area. The adjustable supraglottiscope: (1) provides wide exposure of the supraglottis and much of the lower pharynx, (2) allows instruments to be introduced from the side (between the blades), (3) allows for true suspension, and (4) retracts the endotracheal tube out of the way. These factors provide greater visualization and control of the surgical field and thus improve hemostasis and precision. The adjustable supraglottiscope has been used successfully in a variety of clinical situations. Transoral supraglottic surgery now takes considerably less time and is done with much greater ease. The adjustable supraglottiscope is a valuable instrument in our armamentarium and extends our versatility for endoscopic management of lesions of the supraglottic larynx and lower pharynx.

Glottis↗
PubMed1988

Motor control deficits of orofacial muscles in cerebral palsy.

Voluntary control of the masseter and orbicularis oris superioris muscles was examined in able bodied and cerebral palsied subjects using visual tracking tasks. A smoothed measure of muscle activity (the full-wave rectified and low-pass filtered electromyogram) was presented as a marker on a computer display screen and the subjects could control the vertical position of the marker by voluntarily altering the level of isometric contraction of one of the muscles. A target marker was also displayed on the screen and the subjects were required to follow or "track" the irregular movements of this target with the response marker. Their success in aligning the response marker with the target was analysed for these orofacial muscles. The masseter is influenced by muscle spindle based reflexes, while the orbicularis oris superioris lacks such reflex control. The cerebral palsied subjects displayed similarly poor control over both muscles, implying that their voluntary motor deficits are not related to abnormal muscle spindle based reflexes. It is suggested that the impairment may be related to perceptual-motor integration.

Adult↗
PubMed1979

Induction chemotherapy in advanced squamous head and neck carcinoma with high-dose cis-platinum and bleomycin infusion.

Forty patients with advanced head and neck cancer were treated with combined Cis-platinum-Bleomycin chemotherapy. Cis-diammine dichloroplatinum (DDP) 120 mg/m2 iv was given after prehydration, with mannitol diuresis on Day 1. On Day 3, an initial loading dose of Bleomycin 15 mg/m2 was given by rapid iv push followed by continuous 24 hour intravenous infusion of Bleomycin 15 mg/m2 Day 3 through Day 10. DDP 120 mg/m2 iv was administered again on Day 22. The patients were evaluated for tumor response and resectability between Day 29 to Day 35. Of 39 patients who were evaluable, there were 8 complete responses or CR (20%) and 22 partial responses or PR (56%), for a major response rate of 76%. Nineteen patients had surgery (14 patients whose lesions were initially inoperable and 5 patients who were initially operable). Chemotherapy toxicity in 40 patients included alopecia (40), vomiting (39), mucositis (11), skin rash (10), fever (17), weight loss of more than 5 lbs. (25), WBC less than 3,000 (2), platelets less than 100,000 (1), peak serum creatinine of 2 mg% (3), severe-hearing loss (1), hypersensitivity reaction (2). Surgical complication in 19 patients were pharyngocutaneous fistulae (2), wound dehiscence (1), meningitis and brain abscess (1). There was one death secondary to nephrotoxicity. This particular combination chemotherapy when given as initial treatment, appears very effective in reduction of tumor bulk. Long-term follow-up and randomization is necessary to determine effect upon survival.

Aged↗