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Biomedical subjects

H F Mahieu

Publications and source records attributed to H F Mahieu.

At least 37 records · Page 2Linked to original sources
PubMed1999

The ultra-low resistance Groningen voice prosthesis: aerodynamic properties.

Post-laryngectomy voice rehabilitation using the low resistance (LR) Groningen voice prosthesis has over the past years provided good voice and speech results. The valve part of the prosthesis is largely responsible for the airflow resistance of the prosthesis. This study was performed to evaluate if by modifying the valve part of the LR Groningen prosthesis a lower airflow resistance in vitro could be achieved. Several prototypes with modified valves were tested. Based on the aerodynamic measurements the prosthesis with a single slit of 200 degrees in the 'hat' of the esophageal flange was selected for further evaluation and named the ultra-low resistance (ULR) Groningen voice prosthesis. Aerodynamic measurements were performed and showed the airflow resistance of the ULR Groningen voice prosthesis to be significantly lower than the resistance of the LR Groningen and the Provox voice prostheses.

Equipment Design↗
PubMed1998

Teratoma in a newborn: an unusual cause of airway obstruction.

We report the case of a newborn girl who presented with an inspiratory stridor and apneic episodes due to a mass in the oropharynx. On flexible pharyngo-laryngoscopy, it appeared that on inspiration this swelling, originating from the oropharynx, was sucked into the larynx, obstructing the airway. After intubation under flexible optic control the swelling was excised using the CO2-laser. Histopathological examination showed a teratoma of the oropharynx. The postoperative course was uneventful. Teratomas of the oropharynx are rare and are treated by surgical excision. If respiratory distress accompanies the lesion, priority must be given to securing the airway.

Airway Obstruction↗
PubMed1998

Laryngeal abductor reinnervation with a phrenic nerve transfer after a 9-month delay.

BACKGROUND: Successful restoration of laryngeal abductor function, using the phrenic nerve, has been described in the cat model in the acute phase. However, in clinical practice there is usually a considerable delay between injury to the RLN and presentation for treatment. Delayed reinnervation therefore would be more suitable in clinical practice. OBJECTIVE: To test the feasibility of delayed selective abductor reinnervation following transection of the recurrent laryngeal nerve (RLN). MATERIALS AND METHODS: In 12 cats, the right RLN was severed. Nine months later, the phrenic nerve was anastomosed to the distal RLN stump with all its branches directed toward the posterior cricoarytenoid muscle. For 10 weeks after the reconstruction, electromyography and videolaryngoscopy were performed weekly. Finally, histological analysis of the RLN was performed. RESULTS: Evaluation was possible in 11 cats. Reinnervation of the right posterior cricoarytenoid muscle with the phrenic nerve occurred in 10 cats following nerve anastomosis, but results of videolaryngoscopy showed adequate to good abduction in only 4 cats. The main limiting factor was reduced mobility of the cricoarytenoid joint. Evidence of spontaneous subclinical reinnervation after the delay was observed in 7 cats but apparently did not impede the surgical reinnervation. CONCLUSIONS: Delayed selective laryngeal abductor reinnervation was feasible, but function recovery was less successful than if performed immediately. Future investigations should concentrate on early determinants of spontaneous restoration of function to allow early selection of patients who are eligible for reinnervation surgery.

Anastomosis, Surgical↗
PubMed1998

Malignant lymphoma of mucosa-associated lymphoid tissue in the larynx.

A 36-year-old woman was referred to the department of Otolaryngology/Head and Neck Surgery, University Hospital Vrije Universiteit, because of complaints of hoarseness. A submucosal swelling of the right ventricular fold was found that was subsequently biopsied. Histopathological examination showed a low-grade B-cell non-Hodgkin's lymphoma of mucosa-associated lymphoid tissue (MALT). Treatment consisted of local radiotherapy (to 2800 cGy). During the 2-year follow-up to date there has been no evidence of recurrent disease. To our knowledge, only four cases of MALT lymphomas in the larynx have been reported. The clinical behavior of MALT lymphoma is clearly quite distinct and requires proper recognition to prevent inadvertent misdiagnosis of overtreatment.

Adult↗
PubMed1998

Reinnervation aspects of laryngeal transplantation.

Although restoration of laryngeal function after laryngeal transplantation depends on appropriate reinnervation, non-selective reinnervation procedures result in synkinesis and poor function restoration. This study was performed to test the feasibility of selective reinnervation procedures to restore laryngeal function. Three surgical reinnervation procedures were studied each in a group of ten cats: in group 1 a non-selective procedure in which the recurrent laryngeal nerve (RLN) was cut and reanastomosed; in group 2 selective abductor reinnervation was performed with the phrenic nerve; in group 3 selective abductor reinnervation with the phrenic nerve (PN) was combined with selective adductor reinnervation with the ansa cervicalis. Ten weeks after surgical reinnervation abductor and reflex adductor functions were evaluated with videolaryngoscopy and electromyography. Findings demonstrated that non-selective reinnervation not only gave poor abduction during inspiration but even resulted in paradoxical movement during reflex adduction. Selective abductor reinnervation resulted in good abductor function. Selective adductor reinnervation with the ansa cervicalis brought about muscle tonus in the animals studied but no restoration of reflex adduction. Enhanced activity during respiratory distress gave only slight compromise to the abductor function. In all, selective laryngeal reinnervation with the PN and ansa cervicalis produced good restoration of respiratory laryngeal function. However, deglutition following laryngeal motor and sensory reinnervation with protection of the respiratory tract is probably not sufficient, as in the present group of animals no reflex glottic closure was achieved. More research is required.

Animals↗
PubMed1998

In vitro and in vivo microbial adhesion and growth on argon plasma-treated silicone rubber voice prostheses.

Patients who undergo a total laryngectomy usually receive a silicone rubber voice prosthesis for voice rehabilitation. Unfortunately, biofilm formation on the esophageal side of voice prostheses limits their lifetime to 3-4 mon on average. The effects of repeated argon plasma treatment of medical grade, hydrophobic silicone rubber on in vitro adhesion and growth of bacteria and yeasts isolated from voice prostheses, as well as in vivo biofilm formation are presented here. In vitro experiments demonstrated that initial microbial adhesion over a 4 h time span to plasma-treated, hydrophilized, silicone rubber was generally less than on original, hydrophobic silicone rubber, both in the absence and presence of a salivary conditioning film on the biomaterial. Growth studies over a time period of 14 d at 37 degrees C in a modified Robbins device, showed that fewer Candida cells adhered on plasma-treated, hydrophilized silicone rubber as compared to on original, hydrophobic silicone rubber. For the in vivo evaluation of biofilm formation on plasma-treated silicone rubber voice prostheses, seven laryngectomized patients received a partly hydrophilized "Groningen Button" voice prosthesis for a planned evaluation period of 4 wk. After removal of the voice prostheses, the border between the hydrophilized and the original, hydrophobic side of the prostheses was clearly visible. However, biofilm formation was, unexpectedly, less on the original, hydrophobic sides, although the microbial compositions of the biofilms on both sides were not significantly different. Summarizing, this study demonstrates that in vitro microbial adhesion and growth on silicone rubber can be reduced by plasma treatment, but in vivo biofilm formation on silicone rubber voice prostheses is oppositely enhanced by hydrophilizing the silicone rubber surface. Nevertheless, from the results of this study the important conclusion can be drawn that in vivo biofilm formation on voice prostheses is controlled by the hydrophobicity of the biomaterials surface used.

Journal Article↗
PubMed1998

In vitro and in vivo comparison of the low-resistance Groningen and the Provox tracheosophageal voice prostheses.

This study has been performed to evaluate and compare two frequently used indwelling tracheoesophageal voice prostheses, the low-resistance (LR) Groningen and the Provox voice prosthesis. The airflow resistance in vitro of the Provox prosthesis has been measured and compared to our reported results of the LR Groningen prosthesis. The in vivo study involved fifteen non-myotomized laryngectomees who randomly received one of the two prostheses. Measurements were performed of the intratracheal phonatory pressure and of voice parameters. The intelligibility of speech in noise was evaluated in eight patients. Patients preferences regarding the two prostheses were assessed. Aerodynamic measurements show the Provox voice prosthesis to have a lower airflow resistance. The median intratracheal phonatory pressure for phonation of 75 dB was significantly lower (2.1 kPa) in patients using the Provox voice prosthesis. Speech rate, maximal phonation time and maximal vocal intensity showed no significant difference. The intelligibility of speech in noise produced with the Provox was significantly better than the speech produced with the LR Groningen prosthesis. Subjectively, most patients preferred the Provox prosthesis because speech required less effort. Patients with a hypotonic pharyngoesophageal segment tended to prefer the LR Groningen prosthesis.

Adult↗
PubMed1997

Selective laryngeal reinnervation with separate phrenic and ansa cervicalis nerve transfers.

OBJECTIVE: To perform selective reinnervation of the laryngeal abductor and adductor muscle groups after injury to the recurrent laryngeal nerve, recovering laryngeal function without impairment by synkinesis. DESIGN: Ten cats underwent the surgical procedure. To reinnervate the posterior cricoarytenoid muscle (abductor), a phrenic nerve graft was anastomosed to the main trunk of the recurrent laryngeal nerve. The adductor branch was severed, and the proximal stump was buried in the posterior cricoarytenoid muscle. The sternohyoid branch of the ansa cervicalis was anastomosed to the distal stump to reinnervate the adductor muscle group. After a period of 10 weeks, the laryngeal function was evaluated with videolaryngoscopy and electromyography of the posterior circoarytenoid and vocalis muscles. RESULTS: Of the 10 cats, 9 could be evaluated. Laryngeal abductor function was comparable with the unaffected side in the 9 cats. During respiratory distress conditions, a minor compromise of the maximal abduction was observed in 5 cats. Phonation was not tested, but spontaneous adduction during expiration was seen in all cats. Reflex closure on ipsilateral, supraglottic, tactile mucosal stimulation was seen in only 2 cats. In each cat, evidence of nerve regeneration and reinnervation of both muscle groups was established with electromyography, electrical stimulation, and histological examination. CONCLUSIONS: Using this selective reinnervation procedure, good laryngeal function can be achieved in the cat model, which may be applicable in humans. By reinnervation of the vocalis muscle, muscle tonus is achieved, which is expected to improve voice quality. Using this procedure, however, no active reflex closure may be expected.

Animals↗
PubMed1997

Quantitative analysis of voice quality in early glottic laryngeal carcinomas treated with radiotherapy.

The quality of voice after radiotherapy is generally considered to be better than that after surgery for early glottic (T1a and T1b) carcinomas. Studies concerning voice quality after radiotherapy are scarce, and results have been contradictory concerning actual normalization of voice following therapy. This study was designed to compare several voice parameters of patients successfully treated 1-12 years previously with radiotherapy (5750-7000 cGy) for early glottic carcinoma. Parameters involved an age- and sex-matched control group. Results showed that voice quality following radiotherapy was less than normal for maximum vocal intensity, dynamic vocal intensity range, jitter, and mean fundamental frequency. These findings showed that voice following radiotherapy could not be considered normal.

Aged↗
PubMed1997

A new method for in vivo evaluation of biofilms on surface-modified silicone rubber voice prostheses.

A new method is presented that permits a rapid and accurate in vivo evaluation of biofilm formation on surface-modified silicone rubber voice prostheses. The method is based on partial modification of a Groningen button voice prosthesis by exposing half of the prosthesis to an argon plasma. This results in one side of the prosthesis becoming hydrophilic while leaving the unmodified side hydrophobic as a control. Modified prostheses were placed in patients for an evaluation period of approximately 4 weeks. Despite making the silicone rubber surface hydrophilic, biofilm formation was stimulated when compared to unmodified, hydrophobic silicone rubber. Findings show that biofilm formation on voice prostheses is influenced by hydrophobicity of a silicone rubber surface. The method of partial surface modification used was seen to be suitable for demonstrating such influences regardless of nutrition and other variations in the patient's lifestyle. Microbiological analysis of the biofilms on both sides of the prosthesis valve did not show any changes in microbial composition, with Candida albicans, streptococci and staphylococci being the most commonly isolated strains.

Biofilms↗
PubMed1996

[CO2 laser treatment; an effective and minimally disruptive endoscopic therapy for small glottic laryngeal carcinomas].

OBJECTIVE: To evaluate endoscopic CO2 laser vaporization as a treatment of small glottic laryngeal carcinomas selected by means of video laryngo-stroboscopy. DESIGN: Prospective. SETTING: ENT department, University hospital, Free University Amsterdam. METHODS: Patients with a small glottic laryngeal carcinoma (stage Tis or T1a), were selected by means of video-laryngo-stroboscopy for a single stage endoscopic CO2 laser vaporization treatment as an alternative for radiotherapy. They were followed up for at least 24 months. RESULTS: Three of the 46 patients (6%) developed a local recurrence within 2 years; one of these could be treated once more with the CO2 laser, the other two were irradiated. None of these patients developed metastases in cervical lymph nodes or distant metastases. Most patients (41, 89%) assessed their voices after CO2 laser vaporization as normal or almost normal. Slight dysphonia was reported by five patients (11%). No serious dysphonia or aphonia occurred. CONCLUSION: Endoscopic CO2 laser vaporization, compared with radiotherapy or more extensive surgery, constitutes an adequate treatment for selected patients with small glottic laryngeal carcinomas. As a result of this treatment, it will be possible to preserve the larynx in more patients.

Adult↗
PubMed1996

Laryngeal abductor function after recurrent laryngeal nerve injury in cats.

OBJECTIVE: To determine the influence of severity of neural injury of t he recurrent laryngeal nerve on recovery of laryngeal abductor function and the importance of synkinesis. DESIGN: The recovery of laryngeal abductor function was studied in 30 cats after crushing (second-degree injury) or transection followed by neurorrhaphy (fifth-degree injury) of the recurrent laryngeal nerve, with a reinnervation period of 10 weeks. MAIN OUTCOME MEASURES: Recovery of laryngeal abductor function was evaluated by videolaryngoscopy of spontaneous laryngeal abduction during respiration and electromyography of the posterior cricoarytenoid and vocalis muscles. Neural lesions were applied unilaterally, and recovery of laryngeal function was compared with the contralateral unimpaired hemilarynx. Reinnervation was confirmed by histologic examination. RESULTS: After the recurrent laryngeal nerve was crushed, laryngeal abductor function was similar to normal after a 10-week reinnervation period in 19 of the 20 cats; after neurorrhaphy, no notable recovery of laryngeal abduction resulted in any of 10 cats. Electromyographic recordings disclosed synkinesis after neurorrhaphy and recovery of normal activity patterns after crush injuries. CONCLUSIONS: Severity of neural injury to the recurrent laryngeal nerve influences the recovery of laryngeal abductor function. Damage to the endoneurium leads to misdirection of regenerating axons, inappropriate reinnervation, and synkinesis. No effective laryngeal function can then be expected.

Animals↗
PubMed1996

Laryngeal framework surgery for voice improvement.

Dysphonias resulting from incomplete glottis closure or inadequate vocal fold tension are eligible for phonosurgical correction. Many different phonosurgical techniques have been used for these indications, but the disadvantages associated with augmentation of the vocal folds by means of intracordal injections and the favourable reports concerning laryngeal framework surgery, have lead to a change in treatment policy in many centers. Most phonosurgeons presently advocate laryngeal framework surgery as the first treatment of choice. For correction of incomplete glottis closure usually thyroplasty type 1 and arytenoid adduction techniques are used. For correction of vocal fold tension cricothyroid approximation and thyroplasty type 3 can be used. Often combinations of different techniques are required to achieve the best result. It is therefore essential to perform these procedures under local anaesthesia, so that the voice can be monitored during the surgery and so that the surgery can be tailored to the patient's voice, 119 patients underwent laryngeal framework surgery, 85 of them for correction of incomplete glottis closure, which in 75 patients was due to unilateral vocal fold immobility. The results in this group were good also in long term follow-up. Complications were few and insignificant. For 30 patients, mostly transsexuals, the aim of surgery was to obtain a higher vocal pitch. This was successful in most patients, but 4 patients had cartilage fracture at the time of surgery as a result of the extreme cricothyroid approximation required. In all cases adequate repair could be obtained without further sequellae.

Glottis↗
PubMed1994

Carbon dioxide laser vaporization in early glottic carcinoma.

OBJECTIVE: Presently, widely employed treatment modalities for early glottic carcinoma include radiation therapy, surgical excision, and carbon dioxide laser excision. All these treatments have good oncological results, but poor or questionable functional results in terms of quality of voice and mucosal wave patterns as seen via a laryngostroboscope. We assessed the oncological and functional results of carbon dioxide laser vaporization of the diseased mucosa as a more conservative treatment alternative. DESIGN: Case series. SETTING: Department of Otolaryngology-Head and Neck Surgery in a tertiary care center. PATIENTS: Thirty-three patients with early glottic carcinoma (carcinoma in situ and Tla squamous cell carcinoma) who were referred to our center in the period from 1986 through 1990 were selected for carbon dioxide laser vaporization treatment on the criterion of a still recognizable mucosal wave pattern of the affected vocal fold via a laryngostroboscope. MAIN OUTCOME MEASURES: Local tumor control, voice quality, and a good appearance via a laryngostroboscope. RESULTS: Two patients were excluded from evaluation because a simultaneously diagnosed, incurable second primary tumor precluded frequent follow-up. Of the remaining 31 patients seen during a median follow-up period of 58 months, seven patients died of unrelated causes. A local recurrence of disease developed in two patients and was treated by radiation therapy. A recurrence of disease developed again in one of these patients but was successfully treated by total laryngectomy. Overall, local control of disease was achieved in all patients, with a 97% laryngeal preservation rate. Functional results in terms of voice quality were good in 97% of the patients, 75% of whom even retained a normal voice. Normal or near normal laryngostroboscopic appearance was achieved in 68% of all patients. CONCLUSION: Carbon dioxide laser vaporization is a good treatment alternative for early glottic carcinoma in terms of oncological as well as functional results.

Adult↗
PubMed1993

Selective laryngeal abductor reinnervation in cats using a phrenic nerve transfer and ORG 2766.

Reinnervation of the recurrent laryngeal nerve following nerve injury often leads to laryngeal synkinesis. Selective reinnervation of adductor and abductor muscles might be able to avoid synkinesis. This study presents the results of selective abductor reinnervation in cats, using a phrenic nerve transfer to the recurrent laryngeal nerve and directing all reinnervating axons toward the abductor muscle. Simultaneously, a blind, placebo-controlled, pilot study was performed to evaluate the capacity of ORG 2766, administered subcutaneously (25 micrograms/kg per 48 hours), to facilitate reinnervation by stimulation of axon sprouting. Reinnervation surgery was performed in 10 cats. Postoperative evaluation included videolaryngoscopy, electromyography, histological examination, and quantification of reinnervating axons. Nine cats could be evaluated, of which eight demonstrated electromyographic and laryngoscopic activity as soon as 6 weeks following surgery. The one cat showing no abduction was found to have an inadequate nerve anastomosis and was marked as a surgical failure. After 10 weeks, near-normal or more than normal abduction was seen in the eight cats, and histological proof of reinnervation was obtained in seven of them; one cat could not be evaluated histologically owing to unsuccessful fixation. Although no conclusive evidence was obtained concerning the effect of ORG 2766, the tendencies found warrant further experiments with this compound on laryngeal reinnervation.

Adrenocorticotropic Hormone↗
PubMed1992

Indirect microlaryngostroboscopic surgery.

Detailed preoperative laryngostroboscopic examination is a prerequisite for phonosurgical correction of organic dysphonia. Although suspension microlaryngoscopic surgery has proved its value in the past, it excludes functional control during the removal of vocal fold swellings. Using an indirect microlaryngostroboscopic surgical technique with topical anesthesia, functional control can be achieved during surgery. This enables the removal of vocal fold swellings with a high degree of precision. Postoperative voice evaluation was performed in 31 patients after suspension microlaryngoscopic or indirect microlaryngostroboscopic surgery. The results showed that indirect microlaryngostroboscopic surgery is at least as good as, and in some respects even better than, suspension microlaryngostroboscopic surgery. Large vocal fold swellings, extensive Reinke's edema, and submucosal swellings are considered less suitable for indirect microlaryngostroboscopic surgery, because such lesions require bimanual instrumentation.

Adolescent↗
PubMed1992

Clinical experience with the low-resistance Groningen button.

Since its introduction in 1980, the standard Groningen button prosthesis has been of proven value for post-laryngectomy voice rehabilitation. Its relatively high airflow resistance has, however, been the cause of failure in achieving good post-laryngectomy tracheoesophageal shunt speech in some patients. The low-resistance Groningen button (LRGB) was therefore designed, thus reducing airflow resistance by 50% when compared to the standard device. The clinical performance of the LRGB, and the effect of prophylactic amphotericin, was assessed in 32 patients. The device lifetime, intratracheal phonatory pressures and patients' subjective acceptances of the prosthesis were recorded. Present findings showed that the majority of the patients preferred the LRGB as it required less effort to operate than the standard device. The intra-tracheal phonatory pressure was found to increase with time, but this change was prevented with the prophylactic use of amphotericin to inhibit concurrent colonization by Candida spp, which also helped to prolong the prosthesis lifetime.

Amphotericin B↗