Antiemetic effects of granisetron,droperidol and dexamethasone in otologic surgery

The objective was to assess the antiemetic activity of granisetron, dexamethasone and droperidol in the otologic surgeries. Sixty patients in ASA (American Society of Anesthesiologists) I and II risk groups who underwent surgery for chronic otitis media were assessed in a double blind and randomized trial. The patients were divided into three equal groups. Single intravenous dose of granisetron (3 mg), granisetron (3 mg) plus dexamethasone (8 mg) and droperidol (1.25 mg) were prophylactically administered to the patients in group 1, group 2 and group 3, respectively, and their antiemetic actions were compared. The antiemetic effects of the drugs were not significantly different between the groups (P>0.05). The antiemetic effects also did not differ significantly in the early and late postoperative periods (P>0.05). In conclusion, the results of prophylactic use or side effects of granisetron, granisetron plus dexamethasone or droperidol are similar in middle ear surgery. Therefore, cost effectivity of the antiemetic prophylaxis should be reconsidered in otologic surgery in the light of the results of this study.     

Cerebral cortical veins in otologic surgery

Proximity of the cerebral cortical veins to the overlying dura predisposes them to surgical injury. Labbé's vein, draining a major portion of the posterior temporal and inferior parietal lobes, occurs on the left in 77% and on the right in 66% of patients. Interruption of this vein during otologic surgery may produce devastating neurologic consequences. In this regard, the roentgenographic anatomy of cerebral cortical venous drainage is reviewed. Technical treatment of the temporal dura should include those techniques familiar to the neurosurgeon that ensure the pretection of the temporal lobe and its superficial venous drainage.     

Ionomer-based bone substitute in otologic surgery

Summary During post-set hardening the self-curing bone substitute Ionocem develops a solid bond with the adjacent bony tissue, leaving no empty spaces. The fully matured material can be fixed to bone with freshly mixed cement or it may be used as a blank, e.g. an ossicular implant (Ionos ossicle). After insertion of 945 alloplastic middle ear prostheses over a period of 4.5 years, the take-rate was 94%. In some patients revision surgery became necessary, in 50% of cases because of prosthesis dislocation. A granular version of the cement (Ionogran) was implanted in 46 ears for obliteration of mastoid cavities and showed complete mucosal overgrowth within a maximal period of 3 months. Posterior canal wall reconstruction with the self-curing bone substitute was done in 74 patients, with revisions required in 12 cases because of persistent epithelial deficits in the external ear canal or epitympanic retraction. Overall results showed that the ionomer-based cement was a useful substitute for bone in reconstructive otologic surgery.     

Biologic and nonbiologic materials in otologic surgery

Review of the materials used in middle ear surgery high-light numerous advantages and disadvantages of specific substances. Nevertheless, the great variety of materials available suggests that the ideal implant has not yet been identified.     

The use of Proplast TM in otologic surgery

The use of alloplastic implants in otolaryngologic and maxillofacial surgery has a long history. In recent years, collaborative efforts among materials scientists, surgeons, and dentists have elucidated biological and functional criteria for implant materials. Using these criteria, a new alloplastic material, Proplast^TM was developed, the first of a new generation of materials for implantation, which is a composite of Teflon polymer and elemental carbon. It is very well tolerated as an interphase between metal and plastic implants and tissue. The gross physical appearance is that of a resilient black felt sponge. Because of the ingredients from which Proplast^TM is made it exhibits extraordinary chemical and thermal resistance, permitting firm fusion of pieces 0.5 mm to 5 mm in thickness to metallic and rigid plastic implant materials. The resultant lamination may be sterilized by routine steam autoclave techniques used for metals. Like the elemental carbon with which it is covered, Proplast^TM has the least reaction of any material known when tested in simulated biochemical exposure to pseudoextracellular fluid. The elemental carbon surface renders Proplast^TM extremely wettable to body fluid, permitting precipitation of host proteins in a relatively undenatured form, camouflaging the implant from the body's immunologic rejection mechanism. Since it is 70 to 90 percent porous, Proplast^TM is malleable and easily handled. It can be shaped with a knife or scissors and even shaved to a sheet 1/50th of an inch in thickness with a dermatome. Teflon and other plastics and metals suitable for implantation can be laminated to Proplast^TM to form a composite alloplast with unlimited structural properties and shapes. Even though Proplast^TM is relatively new to otolaryngology, it has been used extensively for the past three years in orthopedic and oral surgery as an interphase material between metal implants and surrounding tissue. These uses have demonstrated that fibrous ingrowth into the Proplast^TM is rapid and acts to stabilize metal and plastic prostheses mechanically. Bound to a Teflon columella it has been successful as a Total Ossicular Replacement Prosthesis, to prevent necrosis of the drum over the malleus with a prosthesis around it, to reconstruct an atrophic retracted drum and to reconstruct the posterior canal wall. Animal experiments are now underway to determine the effect of Proplast^TM on the inner ear as an oval window seal. If these are satisfactory, Proplast^TM will be tried as an oval window seal around a Teflon piston inserted into a small hole in the footplate for otosclerosis.     

Comparative study of otologic surgery in outpatient and hospital settings

The results of nine years' experience with 1,750 otologic surgical procedures are reviewed; 1,110 of these procedures were performed in an outpatient surgical setting and 640 procedures were performed in a general hospital. The results and complications are compared between these two settings. This study includes tympanoplasty, stapedectomy, mastoidectomy, labyrinthectomy, and other otologic procedures. The study is not concerned with minor procedures such as myringotomy. A detailed analysis of results for each type of procedure compares hearing results, graft take rates, and the occurrence of complications in both outpatient and inpatient settings. No significant differences are seen between the results or complications of outpatient and inpatient procedures, thus supporting the use of outpatient surgical settings for most standard otologic procedures.     

Effects of partial neuromuscular blockade on facial nerve monitorization in otologic surgery

OBJECTIVE: Neuromuscular blockade (NMB) is administered as part of a general anesthetic in order to keep the patient immobilized during surgery and has been known to hinder intraoperative neuromonitorization. The aim of this study was to determine the effects of different levels of NMB on electrical stimulation thresholds of the facial nerve during otologic surgery. MATERIAL AND METHODS: Intraoperative facial nerve monitorization was performed in 29 patients with advanced middle ear disease. Electromyographic (EMG) responses were recorded by insertion of needle electrodes into the orbicularis oris and orbicularis oculi muscles. Minimal facial nerve stimulations causing EMG responses in the facial musculature were measured during full recovery from the effects of muscular relaxants and with 25%, 50%, 75% and 100% levels of NMB. These defined NMB levels were maintained by the administration of a drip infusion of atracurium and were assessed objectively by recording the hypothenar muscle action. RESULTS: All of the patients had detectable EMG responses of the facial musculature at the 50% and 75% levels of NMB in response to the electrical stimulation of the facial nerve. The corresponding mean stimulation thresholds were 0.10 +/- 0.08 and 0.11 +/- 0.09 mA, respectively. No responses were measured in 31% of the patients when the level of peripheral NMB was 100%. CONCLUSION: This study suggests that a regulated 50% level of peripheral NMB provides reliable intraoperative EMG monitoring of the facial musculature in response to electrical stimulation and adequate anesthesia, with full immobilization of the patient.     

False ankylosis of the temporomandibular joint after otologic and neurotologic surgery

Two cases of ankylosis of the temporomandibular joint (TM) after otologic and neurotologic surgery involving an approach through the temporal fossa are reported. The etiology is believed to be that of fibrous contracture within the temporalis muscle, which is incised during the procedure. If the possibility of this rare complication is anticipated, the immediate instigation of prophylactic jaw exercises and forced opening with tongue depressors can significantly limit morbidity. If the condition is allowed to become established, then surgical correction by coronoidectomy may be necessary.     

Facial nerve monitoring in otologic surgery: clinical indications and intraoperative technique

While identification of the intratemporal portion of the facial nerve is mandatory in most otologic surgical procedures, inadvertent instrumentation, traction, or thermal injury may still result from inaccurate delineation, purposeful avoidance, or false protection of this critical structure. Improved functional preservation of the facial nerve has been achieved in acoustic neuroma surgery through the monitoring of evoked facial electromyographic activity. This technique may also be used during otologic procedures in which facial nerve manipulation is anticipated in the management of recurrent cholesteatoma, temporal bone trauma, congenital deformity, or purposeful access for cochlear implantation. Potential indications for using facial nerve monitoring in contemporary otologic surgery are detailed through illustrative case presentations, and necessary instrumentation and techniques are briefly reviewed. Intraoperative monitoring can assist the surgeon in isolating the facial nerve when chronic inflammation, traumatic injury, or anomalous development has resulted in distortion or absence of microanatomic landmarks.