Endoscope affects decision making in cholesteatoma surgery.

OBJECTIVE: The aim of the present study was to evaluate the use of intraoperative otoendoscopy as a factor that could influence surgical decision-making in cholesteatoma surgery. MATERIALS AND METHODS: The material of this study included 82 ears with acquired cholesteatoma that were operated on. They were divided into 4 groups according to the surgical technique chosen and the use of the endoscope. Group I included 22 ears that underwent canal wall-down (CWD) tympanomastoid surgery, group II included 20 ears that underwent CWD tympanomastoid surgery with intraoperative use of endoscopy, group III included 20 ears that underwent canal wall-up (CWU) tympanomastoid surgery, and group IV included 20 ears that underwent CWU tympanomastoid surgery with intraoperative use of endoscopy. Endoscopy was used as a complementary tool to microscopy. The follow-up period ranged from 12 to 48 months. RESULTS: Intraoperative remnants of cholesteatoma matrix were detected during both CWU and CWD by the use of the rigid endoscope. However, its incidence was higher in the CWU group (50%) than in the CWD (30%) group. Most of these remnants were in the sinus tympani (37.5%). The mean duration of follow-up was 18.19 (+/-8.7) months. Postoperative residual cholesteatoma was much higher in the CWU group (25%) than in the CWD group (5%). All residuals were from groups of patients in whom intraoperative endoscopy was not used in the primary surgery. CONCLUSION: Our results showed that the use of the endoscope gave the surgeon better control over the pathology, thus achieving better eradication. Stated differently, the use of the endoscope raised the surgeon's confidence level about total removal and thus encouraged the surgeon to keep the canal wall intact while removing cholesteatoma in hidden areas. Therefore, the use of endoscope could be considered an additional tool that may affect decision-making in cholesteatoma surgery.

Value of ear endoscopy in cholesteatoma surgery.

OBJECTIVE: The purpose of this study was to assess the value of ear endoscopy in cholesteatoma surgery and to demonstrate its consequence in improving surgical outcome. MATERIALS AND METHODS: A total of 92 ears with acquired cholesteatoma (primary or secondary) were operated on. In this prospective study, 82 cases were operated on by using canal wall up (CWU) technique, and 10 cases were on operated on by using canal wall down (CWD) procedure. Endoscopically guided ear surgery was incorporated complementary to the microscope as a principal part in the procedure. Second-look endoscopic exploration was performed on some selected cases, depending on the finding during the primary surgery and the postoperative findings of clinical and computed tomographic studies. RESULTS: In the primary surgery after completion of microscopic cleaning, the overall incidence of intraoperative residuals detected with the endoscope was 22.8%. Sinus tympani was the most common site of intraoperative residuals in both CWU and CWD groups, followed by the facial recess and the undersurface of the scutum in the CWU cases. Reconstruction of the hearing mechanism was performed in the primary surgery in 86 cases (93.5%) and postponed to the second stage in only six cases (6.5%). Out of the 82 CWU cases, 35 second-look endoscopic explorations (42.7%) were performed. Three recurrences (8.6%) were identified. Two cases showed a tiny residual cholesteatoma pearl, and the third showed a larger open residual cholesteatoma filling the sinus tympani and extending to the aditus. In this series, no morbidity or complication was encountered secondary to the use of endoscopes in the mastoid or middle ear. CONCLUSION: Incorporating the endoscope into the surgical armamentarium in otology contributes much to the concept of minimally invasive surgery. Minimally invasive endoscopic ear surgery should be accepted as a new horizon in ear surgery. In this study, it became obvious that despite the use of the endoscope in conjunction with the operating microscope, 100% eradication of the disease still could not be achieved; however, the use of endoscopes did reduce the residual cholesteatoma rate.

Endoscopically assisted minimally invasive microvascular decompression of hemifacial spasm.

OBJECTIVE: The aim of this study was to assess the use of endoscopy in minimally invasive surgery of the cerebellopontine angle in cases of hemifacial spasm. MATERIALS AND METHODS: Eighty patients with hemifacial spasm underwent endoscopically assisted microvascular decompression between October 1992 and October 1998, at the Ear, Nose, and Throat Department of Nord Hospital in Marseille, France. The microvascular decompression was performed via a minimally invasive retrosigmoid approach. The cerebellopontine angle was then explored by a 30-degree endoscope to visualize the root exit zone of the facial nerve and the precise location of the site of the conflict. Microvascular decompression was performed under the microscope. If the site was an artery, a Teflon sponge was inserted; if the site was a vein, it was coagulated and then dissected away from the facial nerve. RESULTS: In 80 patients seen regularly for at least 1 year of follow-up, and including patients operated on once or twice, the procedure was successful in 92.5% of patients, brought about improvement in 3.75% (96.25% success plus improvement), and failed in 3.75%. In relation to the type of conflict, success or improvement was experienced by 90.7% of patients with simple conflicts, 86.2% of patients with multiple conflicts, and 87.5% of patients with nutcracker conflicts. No major postoperative complication or mortality occurred in this series. No facial paresis or paralysis occurred immediately postoperatively. Three patients (3.25%) experienced delayed facial palsy. Postoperative cerebrospinal fluid leak occurred in 2 patients (2.5%) and was treated surgically. CONCLUSION: The principle of minimally invasive surgery in the cerebellopontine angle is gaining universal acceptance. The use of endoscopy in microvascular decompression for hemifacial spasm has helped tremendously in improving the results. In this study, the use of the endoscope enabled the authors to identify the site of the conflict in all cases, and to confirm the position of the Teflon sponge before closure.

Endoscopy as a tool in minimally invasive trigeminal neuralgia surgery.

OBJECTIVE: The aim of this study was assessment of the use of endoscopy in minimally invasive surgery of the cerebellopontine angle in cases of trigeminal neuralgia. METHODS: This study comprises 42 cases of trigeminal neuralgia that underwent operation with endoscopic-assisted microvascular decompression between October 1992 and October 1998. This study was performed in the Ear, Nose, and Throat Department, Nord Hospital, in Marseille, France. The decompression was performed by means of a minimally invasive retrosigmoid approach without a cerebellar retractor. The cerebellopontine angle was then explored by a 30-degree endoscope that gives a panoramic view of this space, with clear visualization of the trigeminal nerve from the pons to Meckel's cave, allowing for the identification of the precise location of the site of the conflict. Microvascular decompression was performed under the microscope by separating the offending vessel from the trigeminal nerve; separation was maintained by the insertion of a piece of Teflon. RESULTS: The site of conflict was detected at the root entry zone of the nerve in 35 patients (83.3%) and at Meckel's cave in 7 patients (16.7%). In 32 cases (76.2%), the type of contact between the vessel and the nerve was of the simple type (1 vessel coming in contact with the nerve in a single point); in 6 cases (14.3%), it was a multiple type (2 vessels touching the nerve in the same point); and in 4 cases (9.5%), it was a nutcracker type (2 vessels compressing the nerve between them). After at least 1-year follow-up and a single operation (cases that required a second operation for revision were considered failures), a successful result was obtained in 31 cases (73.8%), and an improvement was obtained in 4 cases (9.5%). The operation was a failure or early recurrence occurred in 7 cases (16.7%). Postoperative complications were rare. A cerebrospinal fluid leak occurred in only 1 case (2.4%) and was subsequently treated with lumbar puncture and a compressive bandage. CONCLUSION: The minimally invasive retrosigmoid endoscopic-assisted microvascular decompression is an acceptable treatment of primary trigeminal neuralgia. Endoscopy provides a unique way to explore the cerebellopontine angle and to identify the exact location of the neurovascular conflict.

Electrocochleographic evaluation of the guinea pig model of endolymphatic hydrops.

Electrocochleography (ECochG) was used to evaluate cochlear function in guinea pigs with experimentally induced endolymphatic hydrops (ELH) before and after osmotic dehydration with either glycerol or urea. We surgically induced ELH in the right ears of 9 guinea pigs, while the right ears of 6 guinea pigs received a sham operation. The left ears of the 15 animals constituted the normal group. Eight weeks after surgery, summating potential (SP) and action potential (AP) amplitudes were measured prior to and following the administration of glycerol or urea. The SPs and SP/AP ratios were reduced in all groups, with no significant differences among groups or between dehydrating agents. Some of the hydropic ears, however, did show an increased AP threshold and a recruitment effect. In measurements from 6 additional animals, serum osmolarity increased more with urea than with glycerol. The guinea pig model remains valuable for investigation of ELH, even though it differs in significant respects from ELH in humans.

Summating potential and action potential gradients on and in the vicinity of the round window in guinea pig.

The purpose of this study was to determine the spatial gradients of summating potential (SP) amplitudes, action potential (AP) amplitudes, and SP/AP ratios for recording loci on the round window (RW) membrane and in its vicinity. Sixteen guinea pigs were tested by means of free-field click and tone burst (2.0 kHz) stimuli. Seven recording regions were specified: five equal-area regions on the RW membrane and two basal promontory regions. Statistically significant differences were found between the promontory regions and the RW membrane regions for the SP, AP, and SP/AP obtained with click stimuli, and for the SP and AP obtained with tone burst stimuli. The SP/AP ratio for tone burst stimuli did not differ significantly across the seven regions. The RW membrane was found to be isoelectric, but there were marked spatial gradients on the basal promontory. These results are of consequence for the interpretation of transtympanic electrocochleography recordings.

Loss of perilymph affects electrocochleographic potentials in the guinea pig.

Alterations of electrocochleographic (ECoG) potentials recorded from guinea pig cochleae have been reported to occur following round window (RW) membrane perforation (perilymphatic fistula). To further evaluate the pathophysiology of perilymphatic fistula, a study was conducted of the short-term effects of acute RW membrane perforation on the amplitude of the summating potential (SP) and the action potential (AP), and the SP:AP ratio. Acute RW membrane perforation was produced in 15 Hartley guinea pigs. The animals were placed in a head dependent position, so that some perilymph would drain from the inner ear following RW perforation. For both click and low frequency tone burst stimuli (2 kHz), the mean AP amplitudes showed variable but progressive deterioration with time following RW membrane perforation. Action potential latencies showed a significant increase with time for both click and tone burst stimuli. Summating potential amplitudes for click and tone burst were typically stable or slightly decreased. Interanimal variability of all measures was typically high. However, AP and SP amplitudes in the same animal were consistently and differentially affected by perforation of the RW membrane. There also were differential effects on the positive and the negative components of the SP, suggesting the interplay of several generator mechanisms. The authors conclude that AP amplitude and, consequently, the SP:AP ratio are sensitive to the creation of a perilymphatic fistula. These results provide support for the use of ECoG tests in the diagnosis of perilymphatic fistula.

[Anastomosis of the facial nerve using fibrin glue, apropos of 60 cases]. / Anastomose du nerf facial par colle de fibrine exclusive, à propos de 60 cas.

The facial nerve was repaired with only fibrin glue anastomosis in 60 cases. The facial nerve was repaired by end-to-end (21 cases) or cable graft (28 cases) anastomosis. In 11 cases, a hypoglosso-facial anastomosis was performed. Grade 3 facial regeneration was observed in 62% of cases after one year follow-up. End-to-end or cable graft anastomosis provided the best results when the anastomosis were glued into the petrous bone or the parotid. The anastomosis should be performed without tension and the vascularization of nerve should be preserved if possible.