Clinical study of transcanal closure of tympanic membrane perforations using a collagen sponge.

MATERIALS AND METHODS: We used an artificial dermis (Terdermis), which is an atero-collagen sponge covered with a sheet of silicon. PATIENTS: Nineteen ears of 17 patients with perforation of the tympanic membrane under various conditions, including large and wet perforations, underwent operation using this collagen sponge. RESULTS: The success rate of closure after the initial surgery was 8/19. The overall success rate of closure after initial and re-operation was 14/19. The success rate of closure was 12/14 for small-sized perforations, 1/4 for middle-sized perforations and 1/1 for a large-sized perforation. Middle- and large-sized perforations required multiple surgeries. The success rate of closure was 11/11 for dry perforations, 3/4 for perforations with light otorrhoea and 0/4 for perforations with extensive otorrhoea. CONCLUSION: This surgery is a low-cost and minimally invasive surgery and has a high closure rate. This surgery is effective on small-sized, dry perforations although it can also close middle- and large-sized dry perforations.

Detection of middle ear cholesteatoma by diffusion-weighted MR imaging: multishot echo-planar imaging compared with single-shot echo-planar imaging.

BACKGROUND AND PURPOSE: Previous reports have shown that DWI is useful in detecting cholesteatoma. SS-EPI is the most widely used DWI technique. However, SS-EPI may have susceptibility artifacts due to field inhomogeneity in the imaging of the temporal bone region. Our purpose was to prospectively evaluate the advantage of MS-EPI for the diagnosis of middle ear cholesteatoma by comparing it with SS-EPI. MATERIALS AND METHODS: We studied 29 patients with preoperatively suspected acquired cholesteatoma. Each patient underwent an MR imaging examination including both SS-EPI and MS-EPI by using a 1.5T MR imaging scanner. Images of the 29 patients (58 temporal bones including 30 with and 28 without cholesteatoma) were reviewed by 2 independent neuroradiologists. The confidence level for the presence of cholesteatoma was graded on a scale of 0-2 (0 = none, 1 = equivocal, 2 = definite). Interobserver agreement as well as sensitivity, specificity, and accuracy were assessed for the 2 readers. RESULTS: Excellent interobserver agreement was shown for both MS-EPI (κ = 0.856) and SS-EPI (κ = 0.820). MS-EPI was associated with higher sensitivity (76.7%) and accuracy (87.9%) than SS-EPI (sensitivity = 50.0%, accuracy = 74.1%) (P < .05), while both methods showed 100% specificity. CONCLUSIONS: Compared with SS-EPI, MS-EPI improves the accuracy of the diagnosis of acquired middle ear cholesteatomas.

Responses to 5-HT in morphologically identified neurons in the rat substantia gelatinosa in vitro.

Bath application of 5-HT (1-1000 muM) induced a tetrodotoxin (TTX)-resistant outward current at the holding membrane potential (V(H)) of -50 mV in 104/162 (64.2%) of substantia gelatinosa (SG) neurons from the rat spinal cord in vitro. The 5-HT-induced outward current was suppressed by an external solution containing Ba(2+), or a pipette solution containing Cs(2)SO(4) and tetraethylammonium. It was reversed near the equilibrium potential of the K(+) channel. The response to 5-HT was abolished 30 min after patch formation with a pipette solution containing guanosine-5-O-(2-thiodiphosphate)-S. The 5-HT-induced outward current was mimicked by a 5-HT(1A) agonist, (+/-)-8-hydroxy-2-(di-n-propylamino) tetralin hydrobromide, and suppressed by a 5-HT(1A) antagonist, WAY100635, suggesting the 5HT(1A) receptor-mediated activation of K(+) channels in the outward current. In 11/162 (6.8%) SG neurons, 5-HT produced an inward current, which was mimicked by a 5-HT(3) agonist, 1-(m-chlorophenyl)-biguanide (mCPBG). The 5-HT-induced outward currents were observed in vertical cells (21/34) and small islet cells (11/34), while inward currents were induced in islet cells (1/5) and small islet (4/5) cells, but not in vertical cells. It is known that most vertical cells and islet cells in the SG are excitatory (glutamatergic) and inhibitory interneurons, respectively, while small islet cells consist of both excitatory and inhibitory neurons. Bath application of 5-HT or mCPBG increased the amplitude and the frequency of spontaneous inhibitory postsynaptic currents (sIPSCs), but no neurons showed a decrease in sIPSC. Furthermore, frequency, but not amplitude, of miniature IPSCs increased with perfusion with 5-HT in the presence of TTX. These findings, taken together, suggest that 5-HT induces outward currents through 5-HT(1A) receptors in excitatory SG neurons. These findings also suggest that the inward currents are post- and presynaptically evoked through 5-HT(3) receptors, probably in inhibitory neurons.

[Use of intubating laryngeal mask airway for three patients with difficult intubation].

We used intubating laryngeal mask airway (ILM) for three patients with difficult intubation, and tracheal intubation was successfully performed through the ILM in all three cases. Difficult intubation in the first case was caused by direct invasion of malignant lymphoma into the right maxillary sinus leading to restricted mouth opening. Neck stiffness due to invasion of metastatic cancer into the cervical spine in the second case and facial trauma caused by traffic accident in the third case gave rise to the difficult intubation. Insertion of the ILM was successfully performed in all the patients following induction of general anesthesia, and the ventilation through the ILM was possible without any difficulties. Subsequently, all patients were intubated through the ILM successfully. We realized that the ILM is useful and should be prepared on the induction of anesthesia in patients suspected of difficult intubation.