Masayoshi Takashima

Membrane Tether Formation from Outer Hair Cells with Optical Tweezers

Optical tweezers were used to characterize the mechanical properties of the outer hair cell (OHC) plasma membrane by pulling tethers with 4.5-microm polystyrene beads. Tether formation force and tether force were measured in static and dynamic conditions. A greater force was required for tether formations from OHC lateral wall (499 +/- 152 pN) than from OHC basal end (142 +/- 49 pN). The difference in the force required to pull tethers is consistent with an extensive cytoskeletal framework associated with the lateral wall known as the cortical lattice. The apparent plasma membrane stiffness, estimated under the static conditions by measuring tether force at different tether length, was 3.71 pN/microm for OHC lateral wall and 4.57 pN/microm for OHC basal end. The effective membrane viscosity was measured by pulling tethers at different rates while continuously recording the tether force, and estimated in the range of 2.39 to 5.25 pN x s/microm. The viscous force most likely results from the viscous interactions between plasma membrane lipids and the OHC cortical lattice and/or integral membrane proteins. The information these studies provide on the mechanical properties of the OHC lateral wall is important for understanding the mechanism of OHC electromotility.

Thyroid Surgery: A Comparison of Outcomes between Experts and Surgeons in Training:

OBJECTIVES: Our objective was to compare the results of thyroid surgery performed by residents in a large metropolitan public hospital (MPH) with those performed by faculty in a large private hospital (PH) setting. METHODS: All records of thyroid surgery performed by otolaryngologists for the period between 1986 and 1998 were reviewed. Inclusion criteria were adequacy of data and follow-up. Ninety-two thyroid procedures performed by residents in an MPH were compared with 181 thyroid operations in a PH setting performed by the faculty of these residents for differences in accuracy of diagnostic studies, operative parameters, and complication rates. RESULTS: The demographic distribution in both groups was similar. Presenting symptoms were twice as frequent in the MPH group (45% vs 22%). More total thyroidectomies were performed in the PH group (49% vs 32%). Blood loss, operative time, and hospitalization days were similar in both groups. Preoperative fine needle aspiration and intraoperative frozen section results showed sensitivities and specificities that were comparable. No permanent vocal cord paralysis was observed in either group. Permanent hypocalcemia was more frequent in the PH group (8.8%:PH vs 5.1%:MPH). CONCLUSIONS: The results of thyroid surgery performed by residents in training in an Otolaryngology-Head & Neck Surgery program in an MPH, measured by rates of complications, length of hospitalization, and duration of surgery, are similar to those of faculty at a PH setting in groups of patients with very similar characteristics.

Prospective Trial of a Short Hospital Stay Protocol After Endoscopic Endonasal Pituitary Adenoma Surgery

OBJECTIVEnPatients typically remain hospitalized for several days after transsphenoidal surgery for pituitary adenoma resection for reasons including pain control, serial neurological assessments, surveillance for cerebrospinal fluid leak, and management of endocrine issues. We sought to determine whether an evidence-based perioperative care protocol combined with an endoscopic approach could lead to routine and safe discharge on postoperative day 1.nnnMETHODSnOur multidisciplinary pituitary group prospectively implemented a perioperative care protocol that emphasizes patient education, early mobilization, and scheduled inpatient and outpatient endocrine assessments on 50 consecutive patients who underwent surgical resection of a pituitary adenoma (82% macroadenomas, 2.1 ± 0.8 cm, maximum 4.5 cm, 18% microadenomas). Endoscopic endonasal surgery characterized by aggressive tumor resection and avoidance of nasal packing and lumbar drains was used in all cases. Lengths of stay, readmissions, and postoperative outcomes were analyzed.nnnRESULTSnUsing the short-stay protocol, 92% (46 of 50) of patients were successfully discharged on postoperative day 1. The average length of stay for all patients was 1.16 ± 0.55 days (range 1 to 4). Postoperative diabetes insipidus occurred in 16% of patients (8 of 50), was effectively managed on an outpatient basis, and did not delay discharge. Readmission was required in 2 patients, in both cases for delayed presentation of a cerebrospinal fluid leak.nnnCONCLUSIONSnA short-stay protocol allows for an overnight hospital stay for patients after pituitary surgery, with a low rate of complications or readmission. This study offers evidence-based guidelines that may be used to avoid complications and facilitate early discharge after transsphenoidal surgery.

Usefulness of Sleep Endoscopy in Predicting Positional Obstructive Sleep Apnea

Objectives The aim of the study was to (1) evaluate whether position affects drug-induced sleep endoscopy (DISE) findings in positional and nonpositional patients and (2) determine which areas of the upper airway obstruct in different body positions. Study Design Prospective, case-controlled study. Setting Academic tertiary care center. Subjects and Methods Twenty-two patients with obstructive sleep apnea (OSA) were enrolled. Two groups were individually recruited to make 11 consecutive patients with positional OSA and 11 consecutive patients with nonpositional OSA. Positional OSA was defined by nonsupine 50% reduction in apnea-hypopnea index. DISE was performed with patients in both lateral and supine sleep positions. Upper airway collapse was compared between the sleep positions and between the 2 groups. Results Most patients (77%) demonstrated multilevel obstruction on DISE. Nearly all patients with positional OSA (91%) had at least a partial improvement in collapse while in the lateral sleep position. Most of the reduction in collapse involved the tongue base and epiglottis (P < .05). Sleep position did not significantly alter the upper airway morphology of patients with nonpositional OSA. Apnea-hypopnea index and body mass index were not significantly different between the 2 groups. Conclusions Sleep position can change upper airway morphology on DISE, particularly positional OSA patients. Hypopharyngeal collapse was the primary site that improved with change in position. DISE in multiple sleep positions should be considered as part of a minimally invasive approach to surgical therapy of OSA.

Effects of nasal surgery on the upper airway: A drug‐induced sleep endoscopy study

To evaluate the impact of nasal surgery on the oropharyngeal and hypopharyngeal anatomy of patients with obstructive sleep apnea (OSA) by comparing drug‐induced sleep endoscopy (DISE) data prior to and following nasal surgery.

Endoscopic resection of tuberculum sellae meningiomas.

Objective To evaluate the results of endoscopic transnasal resection of tuberculum sellae meningiomas (TSMs) as compared with transcranial approaches. Design We retrospectively analyzed five patients who underwent endoscopic endonasal resection of TSM and performed a comprehensive review of articles published between 2000 and 2012 describing the operative treatment of TSMs. Results Gross total resection (GTR) was achieved in four patients (80%). Transient diabetes insipidus occurred in three patients (60%). Preoperative visual field deficit resolved in all patients. Cerebrospinal fluid (CSF) leak occurred in one patient. Analysis of published studies included 1,026 transcranial and 144 transnasal cases. GTR was achieved in 85% of transcranial and 72% of transnasal cases. Visual field deficit improved in 65% of transcranial and 82% of transnasal cases. Rate of diabetes insipidus and CSF leak was higher in the transnasal series. Rate of GTR and visual improvement was higher in endoscopic endonasal as compared with microsurgical transnasal series. Conclusion The literature supports transsphenoidal surgery for the resection of TSMs with significant optic nerve compromise and limited lateral extension. This approach may have an equivalent if not superior outcome over transcranial surgery in visual outcome. CSF leaks are still a challenge but may improve with the use of vascularized nasoseptal flaps.

Recurrent Onodi cell mucocele: rare cause of 2 different ophthalmic complications.

The paranasal sinuses are prone to ostium obstruction by surgery, inflammation, or trauma. Sinus obstruction can trigger formation of a mucocele, which is a cyst lined by respiratory epithelium and filled with mucoid secretions. When mucoceles become infected, a mucopyocele develops. Mucoceles of posterior ethmoid cells, known as Onodi cells, are particularly prone to ocular disturbances because of proximity to the optic nerve. This case report represents the second published account of a recurrent Onodi cell mucocele and the only account demonstrating recurrence with different ophthalmic complications. Approval by the Institutional Review Board of Baylor College of Medicine (Houston, Texas) was obtained.

Three-dimensional sinus imaging as an adjunct to two-dimensional imaging to accelerate education and improve spatial orientation

Develop a novel three‐dimensional (3‐D) anatomical model to assist in improving spatial knowledge of the skull base, paranasal sinuses, and adjacent structures, and validate the utilization of 3‐D reconstruction to augment two‐dimensional (2‐D) computed tomography (CT) for the training of medical students and otolaryngology–head and neck surgery residents.

Staining intraoperative topical solutions with fluorescein: enhancing the safety of sinus surgery

Oxymetazoline HCl 0.05%, 1:100,000 lidocaine with epinephrine (lido+epi), and 1:1000 epinephrine are all colorless solutions employed in sinus surgery. Because lido+epi is injected whereas others are not, care must be taken to label all solutions to avoid inadvertent injection of oxymetazoline or concentrated epinephrine because of life‐threatening complications. Dyes have been used to color solutions for visual identification, but efficacy and cost have never been compared. We sought to determine the effectiveness of surgical marking pen (gentian violet) and fluorescein strips as coloring agents in mediums commonly used in sinus surgery.

Endoscopic Extracapsular Dissection for Resection of Pituitary Macroadenomas: Technical Note

OBJECTIVEnWith the increasing use of the endoscope in neurosurgery, transsphenoidal surgery has undergone a considerable technical evolution. However, most recently reported advances relate to the approach to the sella turcica or to extended transsphenoidal approaches, whereas the dissection technique for pituitary tumor removal itself has received more limited attention. A notable exception is Oldfields elegant description of an extracapsular dissection of functional pituitary microadenomas. Our objective is to describe and illustrate our technique for endoscopic extracapsular resection of pituitary macroadenomas.nnnMETHODSnInfluenced by Oldfields description, we have adopted an extracapsular dissection technique in the endoscopic resection of pituitary macroadenomas. After carefully opening the dura without disrupting the macroadenoma pseudocapsule, the pseudocapsule is dissected inferiorly and laterally. The tumor is then internally debulked and the extracapsular dissection is extended circumferentially; the resection is then complete.nnnRESULTSnThe enhanced visualization and illumination afforded by the endoscope enables the identification and surgical dissection of the pseudocapsule at the periphery of the macroadenomas under direct vision in most cases. As demonstrated in the illustrative case, working around the macroadenoma pseudocapsule allows for a definitive and complete macroadenoma resection with direct visual confirmation and with preservation of the normal gland and diaphragma.nnnCONCLUSIONnThe endoscopic transsphenoidal approach permits an extracapsular dissection of many pituitary macroadenomas. In our preliminary experience, this technique appears to result in a high rate of complete resection without an increase in complications.