„Ein-Schuss-CO2-Laser-Stapedotomie“

BACKGROUND: In order to further optimize the surgical technique with CO(2) laser in stapes surgery, a scanner system was used to obtain a footplate perforation of 0.5-0.6 mm with only one laser application ("one-shot" stapedotomy). PATIENTS AND METHODS: A total of 255 patients with otosclerosis were submitted to primary CO(2) laser stapedotomy with a SurgiTouch scanner. This study discusses the surgical technique and clinical results. RESULTS: An adequately large perforation diameter could be achieved with a single shot in 68% of the patients treated. In 14% of the patients, a second laser application at the same site was necessary. In 18% the perforation had to be enlarged by several slightly overlapping laser applications without using the scanner. There was no evidence of laser dependent inner ear affections. CONCLUSION: CO(2) laser, combined with modern scanner systems, is well suited for application in stapes surgery.     

Clinical results after stapedotomy: a comparison between the erbium: yttrium-aluminum-garnet laser and the conventional technique.

OBJECTIVE: The objective of this study was to assess whether the use of the erbium: yttrium-aluminum-garnet (Er:YAG) laser has negative effects on inner ear function and to compare the short- and long-term hearing outcome of patients undergoing conventional stapedotomy versus laser stapedotomy. STUDY DESIGN: Retrospective review of prospectively collected audiometric data of patients with otosclerosis operated on by one experienced surgeon. SETTING: Academic tertiary referral center. PATIENTS: A total of 266 stapes surgeries were evaluated for intraoperative findings, of which 209 patients were evaluated for preoperative and postoperative hearing thresholds after a 6- to 452-week (mean, 22 wk) audiological follow-up. INTERVENTION: One hundred fifteen (43%) of the operations were performed conventionally, using manual perforators for stapedotomy (Group A); in 115 (43%) surgeries, the perforators were used in combination with the Er:YAG laser (Group B), and in 36 (14%) operations, the Er:YAG was used exclusively for footplate perforation (Group C). MAIN OUTCOME MEASURES: Pure-tone audiometry was performed before surgery, 2 days postoperatively (bone conduction only) and at 5, 26, and 57 weeks postoperatively. RESULTS: A postoperative temporary threshold shift of the bone conduction could be found in all groups. In Group C, where the laser was used exclusively for footplate perforation, this threshold shift was not only the most significant, but also-in contrast to the other groups-not totally reversible. In all techniques, a satisfactory air-bone gap closure could be achieved. The best long-term results (96% of the patients had 相似文献   

The influence of the sequence of surgical steps on complications rate in stapedotomy.

OBJECTIVE: To assess whether the incidence of complications of stapes surgery depended on the sequence of surgical steps and CO2 laser use in stapes surgery. STUDY DESIGN AND SETTING: Retrospective and prospective analysis of 420 consecutive stapedotomies was set in tertiary referral University Hospital. PATIENTS: 376 patients with otosclerosis in whom 420 primary stapedotomies were performed. INTERVENTION: Stapedotomy under local anesthesia using manual perforators and CO2 laser. MAIN OUTCOME MEASURE: The incidence of incus subluxation, floating footplate during stapedotomy. RESULTS: Comparison of the incidence of incus luxation in groups with the piston inserted after removal of the stapes arch, and groups with the piston inserted on the intact ossicular chain showed statistical significance. In the group where perforation of the footplate was performed after removal of the stapes arch floating footplate occurred more often than in groups with reversed sequence of steps. CONCLUSION: Perforation of the footplate before removal of stapes arch reduces the risk of floating footplate, and placing the prosthesis on the incus before removal of stapes arch reduces the risk of subluxation of the incus. CO2 laser stapedotomy with reversed sequence of steps was the safest method of stapes surgery.     

Effect of the pulsed Er:YSGG and Ho:YAG laser on the organ of Corti of the guinea pig cochlear--a scanning electron microscopy study

BACKGROUND: Recent experimental studies have demonstrated that, apart from the continuous wave lasers, several pulsed laser systems are also suitable for stapedotomy. The aim of this study was to clarify whether irradiation of the basal convolution of the guinea pig cochlea could cause morphological inner-ear changes using the Er:YSGG and Ho:YAG laser with laser parameters required for stapedotomy. METHODS: After opening the bulla, the basal convolution of the guinea pig cochlea, whose thickness is similar to that of the human stapes footplate, was irradiated with the Er:YSGG and Ho:YAG laser. The laser parameters used were those necessary for an adequate perforation of a human stapes footplate (500-600 microns). The cochleae were removed 90 minutes, 1 day, 2 weeks, or 4 weeks after laser application. The organ of Corti was examined by scanning electron microscopy in all convolutions. RESULTS: Application of Er:YSGG laser parameters effective for stapedotomy (5 pulses, energy: 85 J/pulse, energy density: 36 J/cm2, total energy: 0.425 J) had no adverse effects on the organ of Corti in the guinea pig cochlea. On the other hand, effective Ho:YAG laser parameters (10 pulses, energy: 210 J/pulse, energy density: 90 J/cm2, total energy: 2.1 J) caused damage to the outer hair cells with fusion of stereocilia and formation of giant cilia leading to partial or total cell loss. The inner hair cells and supporting cells were usually normal. CONCLUSION: Our results clearly demonstrate that the Er:YSGG laser has high application safety. It could prove to be a viable alternative to the thermically acting CO2 laser for stapedotomy. The Ho:YAG laser is not well tolerated in animals and has low application safety. Its use in stapedotomy would be unreliable and dangerous for the inner ear.     

智能CO2激光在耳硬化症手术中的应用

目的：探讨应用智能CO2激光辅助 Fisch 人工镫骨术治疗耳硬化症的疗效。方法回顾性分析28例接受智能CO2激光辅助Fisch人工镫骨手术治疗的耳硬化症患者的临床资料,术中均使用智能CO2激光切断镫骨肌腱、后足弓,并行镫骨足板开窗;所有患者术前及术后6个月行纯音听阈测试,记录0．5、1、2、4 kHz 频率气、骨导阈值。结果所有患者术后均未发生永久性眩晕和感音性聋;所有患者手术前后骨导阈值无明显变化,差异无统计学意义（P＞0．05）;术前及术后6个月言语频率气骨导差中位数分别为30．38（23．13,39．38）及9．75（8．25,10）dB,两者差异有统计学意义（P＜0．05）。结论智能CO2激光切断镫骨肌腱、后足弓,行镫骨足板开窗安全便捷,适合在耳硬化症人工镫骨手术中使用。     

Advantages and dangers of erbium laser application in stapedotomy.

Among different types of lasers, the erbium laser exhibits particularly favourable characteristics for ear surgery. Experiments with application of erbium laser pulses to the isolated stapes connected to an inner ear model confirmed that there was virtually no thermal effect to the inner ear liquid and that the border damage zone on the stapes footplate perforation did not exceed 5-10 microm. Erbium laser pulses, however, produce pressure waves due to the explosive ablation of tissue. Pulses of 10 to 17 J/cm2 producing pressure waves between 140 and 160 dB appear to be a limit for clinical application. With these criteria, an in-house built erbium YAG laser with a fiberoptic delivery device was used in 15 patients for stapedotomy. A special microhandpiece, where a zirconium fluoride fiber was connected to a quartz tip, was developed. In addition, three patients had stapedotomy with a commercially available Zeiss (Opmi TwinER) microscope equipped with a micromanipulator-operated erbium laser beam. One year after surgery, the air-bone gap was closed in all patients to within 20 dB between 0.5 and 3 kHz with only minor permanent bone conduction threshold losses (< 20 dB). However, we observed an immediate postoperative middle and high frequency loss of up to 75 dB on bone conduction threshold measurements 2 h after surgery, suggesting an acoustic traumatization by the erbium laser. This threshold shift recovered close to preoperative values within 6 h. These observations prompted us to discontinue the clinical use of erbium laser for stapedotomy until the problem of temporary acoustic traumatization is resolved.     

Experimental and clinical results of fiberoptic argon laser stapedotomy

Since 1992 a small air-cooled opthalmological argon laser (Augus system, 3 W max.) equipped with a fiberoptic microhandpiece has been used for stapedotomy at the Inselspital, Berne. The microhandpiece has been developed especially for otological purposes in our electronic laboratory. In order to measure the effect of argon laser pulses applied through the handpiece to the ear, we performed temperature measurements in a saline-filled inner ear model by using ultrathin (2 m thick), ultrafast (4 ns) thermosensitive rhodamine-coated polyurethane films. Multiple laser pulses of 1–2.5 W and 0.1 s duration — as used in clinical applications — produced a temperature elevation of about 1 ° C in the liquid of the inner ear model. The local laser effect was then examined histologically on the isolated stapes. The thermal damage zone around the stapedotomy perforation was limited to about 100 m. In a clinical study we compared the results of argon laser stapedotomy (n = 54) with those of a skeeter microdrill stapedotomy (n = 29). Substantial hearing gains were found in all cases in both groups. In the laser stapedotomy group the mean residual air-bone gap (0.5–2 kHz) was 10 dB or less in all cases but one. Inner ear function remained unchanged except for a 40-dB loss at 4000 Hz in one case. Transient vertigo with nystagmus occurred in one case. Facial nerve dysfunction did not occur in any patient. The most important advantage of the laser found was the absence of mechanical trauma to the stapes. Stapes luxation and a floating footplate were avoided. In contrast, thick footplates were more easily perforated with the skeeter. Use of an argon laser equipped with a fiberoptic microhandpiece and a skeeter microdrill as needed seems particularly advantageous for stapedotomy.Adapted from presentations at the Politzer Society Meeting in Punta Ala, 29 August–2 September 1995 and the 65th Annual Meeting of the German Society for ENT, Head and Neck Surgery, Chemnitz, 14–18 May 1994     

Carbon dioxide laser stapedotomy. Thermal effects in the vestibule

Small-fenestra stapedotomy has recently been popularized in efforts to reduce the incidence of sensorineural hearing loss following stapes surgery for otospongiosis. Lasers have been advocated as a tool to fenestrate the stapes footplate. Conversion of radiant energy from the laser into heat in the vestibule represents the greatest potential risk to the inner ear. Using a carbon dioxide laser with a focal point of 150 microns at 300 mm, fenestrations of the stapes footplate were performed in a series of 14 anesthetized cats. The laser power output ranged from 0.47 to 3.05 W, with pulse durations of 0.2 and 0.5 s. Resultant temperature elevations in the vestibule, measured by a thin-wire thermocouple, ranged from 0 to 4.4 degrees C (0 to 8 degrees F) and directly correlated to wattage and duration of the laser-beam pulse. Temperature changes could be reduced by use of lower wattage, shorter pulse duration, timed intervals between pulses, and convection cooling of the promontory.     

Influence of CO2 laser application to the guinea-pig cochlea on compound action potentials

HYPOTHESIS: Experiments in guinea pigs were performed to clarify which, if any, of the CO2 lasers in different modes (continuous wave [cw] and superpulse) can damage the inner ear on application of the laser parameters required for stapedotomy and to determine their application safety. METHODS: The laser effect connected with perforating the basal convolution of the guinea-pig cochlea (cochleostomy) was examined. Acoustic evoked potentials (compound action potentials [CAPs]) yielded information on inner-ear function. RESULTS: In cw mode, even single applications of an approximately four times higher power density (60,000 W/cm2) than necessary for stapedotomy at a pulse duration of 50 msec (energies up to 1 J) and 20-fold applications of effective parameters for a footplate perforation (power density 16,000 W/cm2; energy 0.2 J) did not cause CAP changes. Experimental studies with the CO2 superpulse laser used (peak pulse powers: ca. 300 W) have demonstrated that irreversible CAP alterations already occur in the effective laser range in > 40% of the animals. CONCLUSIONS: Because damage is expected only at much higher energies (> 2 J) than those used clinically, the CO2 laser in cw mode has a high application safety for laser stapedotomy. The application of the CO2 laser in superpulse mode with peak pulse powers of approximately 300 W in stapedotomy appears to be more unreliable and dangerous for the inner ear.     

Short- and long-term results of stapedotomy and stapedectomy with a teflon-wire piston prosthesis

We analyzed the results of 604 cases of primary stapes surgery performed between 1974 and 1997 with replacement of the stapes by a 0.6- or 0.8-mm Schuknecht Teflon-wire piston. At long-term follow-up (1 to 21 years; mean, 7 years), the residual air-bone gap was 10 dB or less in 79% of the cases. The hearing results and postoperative complications were comparable to those reported by authors who used the same evaluation criteria. Although the aim of the surgery was to perform a small stapedotomy with a narrow footplate perforation (0.8 mm), a large stapedotomy or a stapedectomy was performed in 134 cases (22.2%) because of surgical or anatomic conditions. Our results show that the larger footplate perforations allowed a better correction of the air-bone gap at the lower frequencies. The ears with larger perforations did not show a higher incidence of sensorineural hearing loss.     

Retrospective case study of carbon dioxide laser stapedotomy with lens-based and mirror-based micromanipulators

Most clinical studies on carbon dioxide (CO2) (lambda = 10.6 mm) laser stapedotomy have been carried out with the laser guided by a conventional lens-based micromanipulator, with the attendant risks of correct aiming (HeNe) and surgical (CO2) beam misalignment. Hence, engineering advances have attempted to improve laser targeting as well as the spot size focus. The development of the mirror-based micromanipulator was a response to this need but no data concerning its use in stapes surgery is available. We performed a retrospective case-series review of patients treated for otosclerosis between 1992 and 2000. Primary laser stapedotomy was performed in 218 consecutive patients. In the first 78 procedures, the aiming beam (HeNe, lambda = 632 nm) and surgical beam (CO2) were guided with a conventional lens-based micromanipulator whereas in the subsequent 140 procedures, they were guided by using a mirror-based micromanipulator. Hearing was tested at six and 12 months. The mean (SD) airbone gap was 5 dB (4.5) and 4.5 dB (3.9). The mean closure was 15 dB (9.9) and 14.4 dB (9.4). The mean change in the high-tone bone-conduction level was 5.5 dB (7.3) and 7.8 dB (7.5). Overheating of the facial canal produced transient facial paralysis in one case and was due to misalignment of the beams with the lens-based micromanipulator. Use of the mirror-based micromanipulator obviated the need to verify alignment. The light-weight and superior optical yield of this system made it possible to reduce the number of impacts on the footplate by the integral restitution of the energy source. This study demonstrated that the CO2 laser is an effective method for performing stapedotomy. In addition, microtrauma to the labyrinth is reduced by its ability to perform calibrated footplate fenestration without mechanical or vibrational injury to the inner ear. The optical reflection micromanipulator simplified beam alignment and enhanced surgical comfort.     

Comparison of KTP,Thulium, and CO2 laser in stapedotomy using specialized visualization techniques: thermal effects

High-speed thermal imaging enables visualization of heating of the vestibule during laser-assisted stapedotomy, comparing KTP, CO₂, and Thulium laser light. Perforation of the stapes footplate with laser bears the risk of heating of the inner ear fluids. The amount of heating depends on absorption of the laser light and subsequent tissue ablation. The ablation of the footplate is driven by strong water absorption for the CO₂ and Thulium laser. For the KTP laser wavelength, ablation is driven by carbonization of the footplate and it might penetrate deep into the inner ear without absorption in water. The thermal effects were visualized in an inner ear model, using two new techniques: (1) high-speed Schlieren imaging shows relative dynamic changes of temperatures up to 2 ms resolution in the perilymph. (2) Thermo imaging provides absolute temperature measurements around the footplate up to 40 ms resolution. The high-speed Schlieren imaging showed minimal heating using the KTP laser. Both CO₂ and Thulium laser showed heating below the footplate. Thulium laser wavelength generated heating up to 0.6 mm depth. This was confirmed with thermal imaging, showing a rise of temperature of 4.7 (±3.5) °C for KTP and 9.4 (±6.9) for Thulium in the area of 2 mm below the footplate. For stapedotomy, the Thulium and CO₂ laser show more extended thermal effects compared to KTP. High-speed Schlieren imaging and thermal imaging are complimentary techniques to study lasers thermal effects in tissue.     

Use of the excimer laser in stapes surgery and ossiculoplasty of middle ear ossicles: preliminary report of an experimental approach

Surgery of the stapes may cause a number of complications, including hearing deficits and balance disorders. This has made it necessary to look for improved techniques. Small-fenestra stapedotomy has recently been popularized. Lasers have been advocated for use in fenestrating the stapes footplate. On the other hand, sculpting the middle ear ossicles during tympanoplasty is often necessary for the reconstruction of the ossicular chain and the improvement of sound conduction. Using an excimer laser with a wavelength of 193 nm, fenestrations of the footplate and ossicular sculpting were performed on ossicles obtained during ear surgery and from human cadaver temporal bones. The results indicate that the excimer laser can be used effectively and accurately on an experimental basis and that further research is needed before this method can be used for clinical purposes.     

Preoperative diagnosis and surgical strategy in congenital auditory ossicular malformation of 26 ears

We retrospectively analyzed 26 ears of 21 subjects having auditory ossicular malformation and who had undergone auditory reconstruction between April 2004 and December 2010 at our clinic. We checked preoperative condition, pathological classification, surgical procedure, and hearing improvement. We could predict pathological conditions precisely from preoperative computed tomography (CT), including incudostapedial disconnection (9/12, 75%) and malleus and/or incus fixation (7/12, 58%), which tended to be present in external ear malformation, and stapes footplate fixation (0/12, 0%). We could not, however, predict complex malformation (0/8, 0%). Overall success was 90% (18/20) in the 20 ears observed for at least 1 year. In the 2 ears without improved hearing, the first had congenital cholesteatoma and no stapes superstructure, was treated with type IV tympanoplasty. The second had malleus, incus, and stapes fixation and discontinuity between the incus and stapes, and was treated with type III tympanoplasty and stapes mobilization. Preoperative diagnosis is difficult in mixed congenital auditory ossicular malformation, especially stapes footplate fixation, possibly requiring unexpected procedures, with a poor hearing outcome. Preoperative status must thus be evaluated precisely using hearing, tympanometry, acoustic reflex test, and CT. Temporal bone CT and external ear findings are useful in diagnosing middle-ear malformation. Subjects' informed consent should also be obtained due to the possible need for changing procedure based on findings during surgery.     

A study of the intra-operative effect of the Argon and KTP laser in stapes surgery

The intraoperative effect of the Argon and KTP laser was studied on 20 patients who had primary stapes surgery under local anaesthetic; 10 had Argon and 10 had KTP laser stapedotomy. Symptoms of inner ear disturbance such as dizziness and tinnitus were systematically recorded during the laser procedure. Both dizziness and tinnitus were relatively uncommon when the laser was used on the promontory. When the laser was used to transect the posterior crus, all the patients reported transient dizziness, probably from the thermal effect through the posterior crus into the inner ear. However, tinnitus was unusual during this stage. When the laser was used to fenestrate the footplate, only 30% of patients reported a transient dizziness as less laser energy was used. On the other hand, 55% of the patients experienced tinnitus during this stage, which indicates an acoustic effect on the inner ear. There is no difference between the Argon and KTP laser.     

A study of the intra‐operative effect of the Argon and KTP laser in stapes surgery

The intraoperative effect of the Argon and KTP laser was studied on 20 patients who had primary stapes surgery under local anaesthetic; 10 had Argon and 10 had KTP laser stapedotomy. Symptoms of inner ear disturbance such as dizziness and tinnitus were systematically recorded during the laser procedure. Both dizziness and tinnitus were relatively uncommon when the laser was used on the promontory. When the laser was used to transect the posterior crus, all the patients reported transient dizziness, probably from the thermal effect through the posterior crus into the inner ear. However, tinnitus was unusual during this stage. When the laser was used to fenestrate the footplate, only 30% of patients reported a transient dizziness as less laser energy was used. On the other hand, 55% of the patients experienced tinnitus during this stage, which indicates an acoustic effect on the inner ear. There is no difference between the Argon and KTP laser.     

Posterior crus stapedectomy: an obsolete method in otosclerosis surgery?

BACKGROUND: Stapedectomy and stapedotomy with interposition of prostheses are the methods of choice for surgical treatment of otosclerosis. For the present study we resumed and reevaluated the posterior crus stapedectomy, a method based on the principal of renouncing a prosthesis by cutting the posterior crus of the stapes close to the footplate and the anterior crus close to the stapes head. METHODS: The posterior crus is temporarily transposed with the incudostapedial joint remaining intact. After performance of platinectomy and sealing of the oval window with fascia it is repositioned onto the center of the window. RESULTS: 19 of 20 ears operated on applying this technique showed good results (closure of air bone gap) after a mean follow up of 24.6 months. One patient showed persistence of air bone gap of 32.5 dB. Revision surgery revealed that the posterior crus had migrated to the posterior rim of the oval window. No inner ear affection, perilymph fistula or sensorineural hearing loss were observed. CONCLUSIONS: The major advantage of this technique is the avoidance of incus necrosis and foreign body reactions related to the material of the prosthesis. Disadvantages are technical plus the longer duration of the procedure.     

The sandwich cartilage shoe technique for ossicular reconstruction in a case of an unsecure stapes footplate

This article describes a new surgical method for total ossicular reconstruction in a case of a broken stapes footplate. We developed the technique of the "cartilage shoe sandwich," which consists of two surgical steps. First, the closure of the oval window is achieved by a cartilage shoe without a central perforation. During this surgical intervention, the prearrangement of a secure placement of a total ossicular replacement prosthesis is provided by a second cartilage with a central hole that is plugged with silicone. In a staged procedure, the silicone plug is removed and the ossicular reconstruction can be performed. The audiological results of the first patients show a stable inner ear function with an air-conduction gain of 9 dB. The technique described herein has proven to be safe and reliable in total ossicular reconstruction in the event of an unsecure stapes footplate.     

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.     

Surgical results of stapedectomy or stapedotomy (author's transl)

468 stapes operations have been performed at the ENT-Department of the University of Zurich between 1970 and 1978. In one half of the cases, a total or partial removal of the footplate with introduction of a wire connective tissue prosthesis has been used. In the other half, the operation consisted in a limited fenestration of the footplate, which was large enough to accept a wire teflon piston of 0.6 mm diameter. Statistical analysis of the results of both methods shows a better bone conduction threshold for the speech frequencies (500, 1,000 and 2,000 Hz) as well as for air conduction at 4,000 cps after stapedotomy. Complete postoperative deafness occurred in one case following stapedectomy (0.3% of patients with primary operation). The advantages of stapedotomy over stapedectomy are the following: 1. Less trauma to the inner ear, 2. better stability of the position of the prosthesis and 3. better adaptation of the length of the prosthesis. The surgical steps used for stapedotomy are described.