Reducing the pain associated with local anaesthetic infiltration for open carpal tunnel decompression.

This prospective, randomized study assessed the effectiveness of buffering lidocaine with sodium bicarbonate for reducing the pain associated with local anaesthetic infiltration for open carpal tunnel decompression. Twenty-one patients undergoing bilateral open carpal tunnel decompression received, in a randomized manner, lidocaine 1% with adrenaline (1:200,000) in one hand and the same local anaesthetic buffered with 8.4% NaHCO3 at a 5:1 ratio in the other hand. Pain, especially its burning element, was evaluated on a visual analogue scale and was significantly reduced with the buffered solution. The buffering was effective for all patients and no adverse effects were noted. This is a safe, easy and quick method for making open carpal tunnel surgery less uncomfortable to patients.

Hearing evaluation with distortion-product otoacoustic emissions in young patients undergoing haemodialysis.

Sensorineural hearing loss is frequently reported in young patients with chronic renal failure having haemodialysis. The effect of a single session of haemodialysis on hearing acuity was assessed prospectively in nine children with end-stage renal disease using pure-tone audiometry (PTA) and distortion-product otoacoustic emissions (DPOAEs). Results were compared with those obtained from nine audiologically normal healthy children also tested with PTA and DPOAEs twice during a 4-h interval. Sensorineural hearing loss of unknown aetiology was found in 55.5% of renal patients, mainly in the higher frequencies. Patients on HD had mean PTA thresholds significantly poorer than those of the control group in the frequency range 1000-12 000Hz (P < 0.05). Their mean DPOAE amplitudes were significantly lower in all frequencies > 1184 Hz (P < 0.05). Furthermore, patients' ears with normal PTA thresholds between 250 and 4000 Hz also had decreased DPOAE amplitudes. No significant changes in PTA thresholds or DPOAE amplitudes were encountered in renal patients before and after a HD session (P > 0.05). Changes in PTA thresholds or DPOAE amplitudes were not significantly different than those in the control group (P > 0.05). In conclusion, sensorineural hearing loss of unknown origin, especially in high frequencies, is frequent in young renal patients under HD and single HD sessions do not seem to alter the hearing acuity of these patients. DPOAEs seem to be more sensitive to incipient cochlear damage than behaviour thresholds in monitoring renal patients.

Evoked otoacoustic emissions--an approach for monitoring cisplatin induced ototoxicity in children.

OBJECTIVES: Cisplatin chemotherapy is associated with an increased risk of ototoxic changes. The incidence of hearing loss after the 1st cisplatin-infusion session is only scarcely mentioned in the international literature. With increasing survival rates, prevention and/or early detection of ototoxicity are important for providing management options. The predictive value of pure-tone audiometry in early detection of ototoxicity has been questioned, particularly in the higher frequencies. Otoacoustic emissions appear to be more sensitive to cochlear insult than the conventional pure-tone audiometry. The aims of our study was (a) to define the extent of hearing damage in children after the 1st cisplatin-infusion session (50 mg/m(2)); and (b) to compare the efficacy of otoacoustic emissions (transient evoked otoacoustic emissions, distortion-product otoacoustic emissions) with that of pure-tone audiometry as methods of audiological monitoring. METHODS: Baseline audiometric (0.25-8 kHz) and otoacoustic emission testing (transient evoked otoacoustic emissions, distortion-product otoacoustic emissions) was conducted in 19 children, 12 of whom met the criteria for inclusion in the final study. Comparisons were performed between baseline measurements and those recorded after the 1st cisplatin course. Transient evoked otoacoustic emissions were analyzed in terms of emission level and reproducibility as a function of frequency (0.8-4 kHz). Distortion-product otoacoustic emissions were obtained as DP-grams and I/Q functions at 4,6 and 8 kHz. The DP-gram amplitude, the dynamic range and the detection thresholds from the I/Q functions were determined for each child. RESULTS: Threshold changes from baseline were founded to be statistically significant from 4-8 kHz in 50% of the children (P<0.01). Transient evoked otoacoustic emissions revealed a significant decrease in the emission level and in the reproducibility at the highest frequency tested (4 kHz, P<0.01), reflecting the results seen in pure-tone audiometry. Distortion-product otoacoustic emissions demonstrated a significant threshold shift, a reduced dynamic range and a decreased amplitude in the frequencies >3 kHz (P<0.05). Furthermore, DP-gram amplitude also reduced significantly at 3 kHz (P<0.05) without any similar change in pure-tone audiometry. CONCLUSIONS: A significant high-frequency hearing loss is identified in children even after one low-dose cisplatin-infusion session. As ototoxicity screening tools DP-grams were extremely sensitive and superior to pure-tone audiometry and/or transient evoked otoacoustic emissions. Their use is recommended for regular monitoring of cochlear function, aiming in prevention of permanent damage. Some suggestions for reducing the potential for cisplatin ototoxicity (chemoprotective agents, gene therapy, inhibition of apoptosis) are also discussed.

Comparative study of the laryngeal innervation in humans and animals employed in laryngeal transplantation research.

Laryngeal transplantation is receiving increased attention. Re-innervation of the transplanted larynx is critical for a successful functional outcome. Different anatomical models (dog, cat, rat, pig) have been employed for experimental purposes. Interspecies similarities and differences are important for extrapolating the experimental results to humans. We present a review of the anatomical course and regional branching patterns of the laryngeal nerves in both humans and animals currently being employed in laryngeal transplantation. The clinical and surgical implications are also discussed.

Raman spectroscopy for early detection of laryngeal malignancy: preliminary results.

OBJECTIVE: Raman spectroscopy, the analysis of scattered photons after monochromatic laser excitation, is well established in nonbiological sciences. Recently this method has been used to differentiate premalignant and malignant lesions from normal tissue. Its application for early diagnosis has been explored in a variety of sites (e.g., esophagus, cervix), but not, to date, in laryngeal cancer. The objective of this study was to perform a feasibility study of the use of Raman spectroscopy for early diagnosis of laryngeal malignancy. METHODS: Biopsy specimens were snap-frozen, and top sections were sent for histopathological analysis. Only homogenous samples with clearly defined pathological findings were used in this study: seven histologically normal samples, four exhibiting dysplasia, and four with carcinoma. Samples were defrosted and placed under a Renishaw (Wotton-Under-Edge, UK) System 1000 Raman microspectrometer for analysis. Between 5 and 12 spectra were acquired from each sample, with an excitation wavelength of 830 nm. Average characteristic spectra for each disease or condition were compared. Further multivariate statistical analysis of the data was carried out to evaluate and maximize the differences in the spectra for each disease or condition. RESULTS: The most visible differences in the spectra occur between 850 and 950 cm(-1) and 1,200 and 1,350 cm(-1). The later peaks are directly related to protein conformation and C-H bond stretch in nucleic acid bases. The relative intensity of the nucleic acid peak increases with progression to malignancy. Use of linear discriminant analysis made it possible to separate the spectra with disease to a greater degree of accuracy than using empirical peak ratio methods alone. Classification results obtained from cross-validation of the discriminant model showed prediction sensitivities of 83%, 76%, and 92% and specificities of 94%, 91%, and 90% for normal, dysplastic, and squamous cell carcinoma of the larynx, respectively. CONCLUSIONS: There was strong evidence to support spectral identification of malignancy and earlier abnormal changes. More substantive studies of the spectral differences between malignant and non-neoplastic tissue are warranted. Raman spectroscopy may become a useful adjunct to pathological diagnosis allowing directed or guided biopsies and assessment of adequacy of resection margins.

Stapedotomy in osteogenesis imperfecta patients.

Osteogenesis imperfecta (OI) is a connective tissue disorder characterized by osseous fragility, blue sclerae and hearing loss. In order to assess the impact of stapedotomy on improving hearing on OI, a retrospective, one-group, pre-test-post-test design was used to compare the pre-operative and post-operative audiograms of nine OI patients, treated with stapedotomy for their mixed hearing loss. Operative findings included fixation or thickening of the stapes footplate with normal superstructure configuration and hypervascularization of the promontory mucosa. Immediate post-operative results showed a significant improvement (p < 0.05) from 250-4000 Hz in air conduction and from 250-2000 Hz in bone conduction. A significant closure of the air-bone gap between 250-2000 Hz was also achieved (p < 0.05). The long-term results remained satisfactory with a mean threshold shift of 8 dB HL and an almost unchanged air-bone gap. These satisfactory results and the lack of complications make stapedotomy an appealing method for the management of OI-associated hearing loss.

Modified supracricoid partial laryngectomy with cricohyoidopexy: series report and analysis of results.

Aiming to improve voice quality and to facilitate swallowing rehabilitation, we modified the supracricoid partial laryngectomy with cricohyoidopexy by preserving the posterior segment of the true vocal cord on the less involved side of the larynx. Between 1983 and 1994, 13 patients with supraglottic cancer were treated with this modified procedure. The possibility of incomplete tumor excision was eliminated by careful patient selection and intraoperative reconfirmation of tumor extent with frozen sections. Our results have been promising, with a 76.9% 3-year survival rate and a 69.2% laryngeal preservation rate. There were 7 recurrences, 3 local (2 at the superior border of the cricoid and 1 at the cricoarytenoid region) and 4 nodal, in 5 patients. Distant metastases developed in another patient. Three patients, 2 with local and nodal recurrence and 1 with distant metastases, died of disease. Functional outcomes were also good, with all patients achieving normal swallowing by the end of the first year, although 5 patients required temporary gastrostomy for transient swallowing impairment. Early decannulation and satisfactory voice quality were achieved in all cases. We believe that with proper patient selection this modified procedure is effective both for tumor control and for preserving a more functional larynx.

Squamous cell carcinoma presenting as a cutaneous horn.

A cutaneous horn is a variably sized, cohesive, keratotic, usually conical lesion associated with a broad spectrum of pathology at their base (benign, premalignant or malignant). Two cases of a squamous cell carcinoma in the face, with a horn formation are presented, highlighting the need for careful management of such lesions due to the high incidence of malignant or premalignant histology. The existing literature is also briefly reviewed.

Otoacoustic emissions--an approach for monitoring aminoglycoside induced ototoxicity in children.

OBJECTIVES: The early detection of hearing impairment caused by ototoxic drugs, such as aminoglycosides, has been the aim of research world-wide. Histopathological studies have shown that the outer hair cells are the most susceptible cochlear components to injury from ototoxic drugs like aminoglycosides. Otoacoustic emissions reflect the functional status of the outer hair cells and constitute the only non-invasive means of objective cochlear investigation. The aim of this study was to evaluate the potential of otoacoustic emissions in early identification of aminoglycoside-induced cochlear dysfunction. In addition, a comparison with pure-tone audiometry or auditory brainstem responses was performed in order to determine if this test might provide a more reliable method of monitoring early ototoxic insults to the cochlea. METHODS: Twenty four children receiving gentamicin (4 mg/kg once daily) for 6-29 days were included in the study. Eleven children received gentamicin for up to 7 days (group A), while 13 underwent longer-term therapy lasting 8-29 days (group B). Hearing was serially monitored using transient evoked otoacoustic emissions and pure-tone audiometry (0.25-12 kHz) or auditory brainstem responses for younger or uncooperative children. Transient evoked otoacoustic emissions data were analysed in terms of emission amplitude and response reproducibility as a function of frequency. RESULTS: All patients yielded a normal baseline audiometric assessment upon hospital admission. For group A patients no significant changes in hearing levels were observed either by pure-tone audiometry (P = 0.2), auditory brainstem responses (P = 0.3) or transient evoked otoacoustic emissions (mean response: P = 0.06, reproducibility by frequency: P > 0.05). For group B patients no significant changes in hearing levels measured by pure-tone audiometry (P = 0.1) or auditory brainstem responses (P = 0.4) were observed. Transient evoked otoacoustic emissions however revealed a statistically significant decrease in the mean response level (P = 0.017) and in the reproducibility over the whole frequency spectrum (1 kHz: P = 0.0057, 2 kHz: P = 0.0247, 3 kHz: P = 0.0134, 4 kHz: P = 0.0049, 5 kHz: P = 0.0019). CONCLUSIONS: The findings suggest that transient evoked otoacoustic emissions are an extremely sensitive measure of the early effects of aminoglycoside-induced injury to the peripheral auditory system. Therefore, their use is recommended for regular monitoring of cochlear function, in the presence of potentially toxic factors, aiming at prevention of permanent damage.

CO2 and KTP-532 laser cordectomy for bilateral vocal fold paralysis.

Laryngeal obstruction due to bilateral vocal fold paralysis has been treated in many different ways. The CO2 laser or KTP-532 laser endoscopic cordectomy described in this report is a slight modification of the posterior partial cordectomy proposed by Dennis and Kashima. This technique was used in 18 patients (14 with the CO2 and four with the KTP-532 laser). Prophylactic tracheostomy was performed pre-operatively. Post-operative results were excellent in nine cases, good in seven cases and poor in two cases who had to remain with a permanent tracheostomy tube with a speaking valve. The main complications noted were the formation of a granuloma (seven cases) and arytenoid oedema (six cases). Revision surgery was performed in the seven cases with granuloma formation and in the two with persistent oedema. The results and the post-operative findings from the use of the two lasers were similar.