[Standardized risk-based antibiotic prophylaxis and adhesive film dressing for the prevention of wound infection following cochlear implantation]. / Standardisierte risikobasierte Antibiotikaprophylaxe und adhäsiver Filmverband zur Prävention von Wundinfektion bei Cochleaimplantation.

BACKGROUND: There is no consensus in the pertinent literature regarding the optimal antibiotic prophylaxis (AP) for cochlear implantation (CI). This study evaluates the implementation of standardized risk-based AP combined with application of an adhesive film dressing. MATERIALS AND METHODS: All CI cases since September 2019 were retrospectively reviewed for postoperative wound complications. While all patients received preoperative AP with ceftriaxone, postoperative AP after CI in patients older than 7 years was no longer routinely performed in our clinic. Exceptions were made according to predefined criteria for an increased risk of infection. The wound was covered with a transparent adhesive polyurethane film. RESULTS: In 72% of the 219 cases, we did not perform postoperative AP. The overall wound complication rate was 2.7% (in the groups with and without postoperative AP, 4.9% and 1.9%, respectively). Wound infection did not occur in any of the patients without postoperative AP older than 70 years (n = 32), with controlled diabetes mellitus (n = 19), or with reimplantation due to technical defect (n = 19). The film did not need to be changed until the suture material was removed. CONCLUSION: Standardized risk-based AP can avoid prolonged administration of antibiotics in selected patients. The film dressing permits continual examination and sufficient wound protection.

Novel noncanonical splice site variant causes mild CHD7-related disorder with variable intrafamilial expressivity.

The clinical diagnosis criteria for CHARGE syndrome have been revised several times in the last 25 years. Variable expressivity and reduced penetrance are known, particularly in mild and familial cases. Therefore, it has been proposed to include the detection of a pathogenic CHD7 variant as a major diagnostic criterion. However, intronic variants not located at the canonical splice site are still underrepresented in mutation databases, often because functional analysis is not performed in the diagnostic setting. Here, we report a two-generation family that did not meet the criteria for CHARGE syndrome, until the molecular findings were taken into account. By exome sequencing, we detected an intronic variant in a male individual, who presented with unilateral external ear malformation, bilateral semicircular canal aplasia, polydactyly, vertebral body fusion and a heart defect. The variant was inherited by his mother, who also had bilateral semicircular canal aplasia additionally to unilateral sensorineural hearing impairment, unilateral mandibular palpebral synkinesia, orofacial cleft, and dysphagia. Using RNA studies, we were able to demonstrate that aberrant splicing occurs at an upstream cryptic splice acceptor site, resulting in a frameshift and premature stop of translation. Our data show causality of the noncanonical intronic CHD7 variant and end the diagnostic odyssey of this unsolved phenotype of the family.

Piezoelectric ear surgery: a systematic review.

BACKGROUND: The piezoelectric instrument (PEI) offers a novel technique for bone removal in ear surgery with a combination of micro-oscillation and cavitation. The aim of this review is to explore the advantages, disadvantages, and limitations of this instrument in comparison to the drill. MATERIALS AND METHODS: We conducted a search of PubMed/MEDLINE and Google Scholar in accordance with the PRISMA recommendations. The primary selection included all studies reporting on the use of PEI in ear surgery or its effect on the inner ear. Only studies with a control group were included in the secondary selection. RESULTS: The first search identified 49 studies between 2003 and 2022. These reported on a total of 1162 ear operations, during which PEI was used for various indications. Most data were based on uncontrolled retrospective studies or case reports (76%). Only one of the five controlled clinical studies was prospective and randomized. The advantages of PEI weighed against its limitations and disadvantages were critically analyzed in comparison to the drill. CONCLUSION: Piezoelectric surgery is an innovative and promising surgical technique in the temporal bone. PEI appears to enable safer and more precise bone removal in close proximity to soft tissue when compared to the drill. The slower bone removal and cost factors represent current limitations to its wider use in ear surgery.

[Piezoelectric ear surgery: a systematic review. German version]. / Piezoelektrische Ohrchirurgie: systematische Literaturübersicht.

BACKGROUND: The piezoelectric instrument (PEI) offers a novel technique for bone removal in ear surgery with a combination of micro-oscillation and cavitation. The aim of this review is to explore the advantages, disadvantages, and limitations of this instrument in comparison to the drill. MATERIALS AND METHODS: We conducted a search of PubMed/MEDLINE and Google Scholar in accordance with the PRISMA recommendations. The primary selection included all studies reporting on the use of PEI in ear surgery or its effect on the inner ear. Only studies with a control group were included in the secondary selection. RESULTS: The first search identified 49 studies between 2003 and 2022. These reported on a total of 1162 ear operations, during which PEI was used for various indications. Most data were based on uncontrolled retrospective studies or case reports (76%). Only one of the five controlled clinical studies was prospective and randomized. The advantages of PEI weighed against its limitations and disadvantages were critically analyzed in comparison to the drill. CONCLUSION: Piezoelectric surgery is an innovative and promising surgical technique in the temporal bone. PEI appears to enable safer and more precise bone removal in close proximity to soft tissue when compared to the drill. The slower bone removal and cost factors represent current limitations to its wider use in ear surgery.

Piezoelectric canalplasty for exostoses and osteoma.

OBJECTIVE: To evaluate the safety profile and surgical technique for removal of symptomatic exostoses and osteoma of the external auditory canal with a micro-oscillating piezoelectric device. METHOD: A chart review was conducted on patients undergoing piezoelectric canalplasty between 2019 and 2021 at tertiary referral hospital. Surgery was performed by two surgeons with varying experience. Bone removal was achieved using both osteotomy and osteoplasty. Postoperative complications, operative time and hearing outcome were evaluated. RESULTS: The study comprised 16 patients (16 ears). No major complications occurred. The skin of the auditory canal was completely preserved in all patients without injury to the tympanic membrane. Except for one patient with known noise-induced hearing loss, there was no postoperative deterioration of the bone-conduction threshold more than 10 dB HL at any frequency. The difference of the bone-conduction threshold in pure-tone audiometry (average for 0.5, 1, 2 and 4 kHz) three weeks postoperatively had a median of 0.6 dB ± 5.7. One patient complained of temporary new tinnitus. One patient had prolonged wound healing. Mean operative time was comparable with literature data. CONCLUSION: The atraumatic characteristics of the piezoelectric instrument enable low-risk removal of external auditory canal exostoses and osteoma. Through the combination of precise osteotomy and osteoplasty, this novel instrument has the potential to become established in routine canalplasty.

Does severity of cerebral MRI lesions in congenital CMV infection correlates with the outcome of cochlear implantation?

The objective is to investigate whether there is a correlation between the severity of typical brain lesions in congenital cytomegalovirus (cCMV) infection and cochlear implant (CI) outcome. The design of the study is a retrospective single-institutional chart review (2005-2015), performed in a tertiary academic referral center. 23 children with typical signs of cCMV infection on cerebral magnetic resonance imaging (MRI) and bilateral severe-to-profound sensorineural hearing loss were retrospectively evaluated. They were graded in three groups according to the severity of brain involvement. The average implantation age of the first CI is 1.8 years (range 0.6-5.8). Five patients were implanted unilaterally, 18 bilaterally. The average follow-up time after implantation was 3.3 years (range 0.6-6.9). Hearing performance was assessed using the Categories of Auditory Performance (CAP), and speech development was assessed using Speech Intelligibility Rating (SIR). The outcome in each group showed great variation. The majority of children achieved moderate-to-good auditory and speech rehabilitation. The children with severe MRI changes had comparatively better auditory than speech scores. There were children with good auditory performance (CAP ≥6) both in grades II and III, while poor performers (CAP ≤3) were encountered in each group. The severity of brain lesions on its own does not directly correlate with the outcome of cochlear implantation. Despite good retrospective diagnostic evidence of cCMV infection through MRI patterns, this has no predictive role for future hearing and speech rehabilitation.

Impact of the surgical wound closure technique on the revision surgery rate after subtotal petrosectomy.

The objective of the study was to examine the impact of the surgical wound closure technique as protection of the obliterated tympanomastoid cavity on the revision surgery rate after subtotal petrosectomy (SP). This is a retrospective case series conducted in a tertiary care referral center. 199 patients (212 ears) with recurrent chronic otitis media underwent SP followed by tympanomastoid obliteration with abdominal fat at a single tertiary referral center between 2005 and 2015. 124 SP were carried out without (group A), 74 with temporalis muscle flap (group B) and 14 with reinforcing material like polydioxanone foil or bovine pericardium or allogenic fascia lata (group C) for wound closure. The evaluated follow-up was either until the scheduled device implantation or 6 months postoperatively. We assessed the rate of postoperative wound healing disorder with revision surgery according to the surgical technique for closure of the obliterated cleft. Revision surgery due to impaired wound healing was necessary in 16 % of the total cases (group A: 18.5 %, group B: 10.8 %, group C: 21.4 %). Further analysis concerning the dehiscent area in both sites (retroauricular and blind sac of the external auditory canal) was conducted and discussed. There was no significant difference observed in the rate of revision surgery between the three groups. The wound healing process after SP is determined by many factors and cannot be significantly influenced solely by reinforcing tissue like the temporalis muscle flap or supporting materials.

Multi-mode grounding and monophasic passive discharge stimulation avoid aberrant facial nerve stimulation following cochlear implantation.

We report on a case with severe facial nerve stimulation via a cochlea-facial nerve dehiscence that was most likely the result of prolonged occlusive hydrocephalus. The successful treatment of this adverse effect demonstrates for the first time its complete resolution using a multi-mode grounding and monophasic passive discharge stimulation.

Cochlear reimplantation from mid-scala to lateral wall electrode array: Surgical and hearing outcome.

A mid-scala cochlear implant electrode array, which was inserted with an atraumatic round window approach, could be replaced with longer lateral wall electrode array. Deeper electrode insertion seems to have beneficial influence on the hearing quality.

Piezosurgery in Translabyrinthine-Approach Exposure of the Internal Auditory Canal.

OBJECTIVE: To assess the applicability of the piezoelectric device in translabyrinthine-approach exposure of the internal auditory canal. METHODS: In three cases with vestibular schwannoma, the bone around the internal auditory canal was completely removed by means of piezosurgery. Evaluation was performed by an experienced surgeon, and a second relatively inexperienced surgeon. RESULTS: Irrespective of surgical experience, piezosurgery proved to be a safe method for exposure of the internal auditory canal. Compared with the conventional procedure it provides an improved surgical view and more precise bone removal in a narrow operating field. This novel technique has the characteristics to reduce the corresponding risk of accidental slipping with consequent thermal and mechanical injury to the dura and neurovascular structures. The major disadvantage of piezosurgery is the longer time required for bone removal. CONCLUSION: The micro-oscillating piezoelectric device is a useful adjunct to the rotating burr during removal of the bone around the internal auditory canal in translabyrinthine approach. It could reduce the risk of injury to neurovascular structures at the bone-to-soft tissue interface.

Reprint of Corrosion casting of the temporal bone: Review of the technique.

The temporal bone has the most sophisticated anatomy of the whole skeleton. Its study is a challenge for students and surgeons. An inverse model of the visually obscured cavities and canals can facilitate better three-dimensional orientation and investigation. This can be made by means of corrosion casting, which is an established technique first documented on the temporal bone at the beginning of the nineteenth century. The prepared specimens are suitable not only for teaching purposes but also for research on the fascinating topography of the osseous labyrinth and the whole temporal bone. Many important studies on temporal bone anatomy are based on this technique. An extensive review of the pertinent literature is provided in relation to each method available.

Impact of occlusive material and cochlea-carotid artery relation on eustachian tube occlusion in subtotal petrosectomy.

OBJECTIVE: To evaluate the success rate of eustachian tube (ET) occlusion in subtotal petrosectomy relative to the occlusive material used and to the varying protympanum anatomy, by means of standardized alignment of the cochlea-carotid artery relation on computed tomography images. PATIENTS AND METHODS: All cases of subtotal petrosectomy carried out by the same surgeon at a tertiary care referral center were retrospectively evaluated. Only cases with available computed tomography prior to second stage cochlear or middle ear implantation were included. The occlusive material was either muscle tissue or oxidized regenerated cellulose in combination with bone wax. On 3D multiplanar image reconstruction, the varying topographic interrelation of the cochlea and the petrous carotid artery was measured and categorized into two groups: detachment or overlapping. RESULTS: In 9 (31%) of the 29 included cases there was insufficient occlusion of the ET. In none of these cases was an infection of the fat filling in the obliterated cavity observed during the implantation procedure on second stage (average 10 months interval). The failure rate of both occlusion materials was almost the same (using muscle tissue, in 4 (33.3%) of 12 or oxidized regenerated cellulose, in 5 (29.4%) of 17 cases). It was also similar for both materials in each of the anatomic variation groups. CONCLUSIONS: An incomplete occlusion of the ET alone does not appear to lead to an infection of the obliterated cavity. Autologous muscle tissue and oxidized regenerated cellulose had similar rates of ET occlusion failure. The topographical variance of the protympanum appears to have no direct influence on the success of the ET occlusion.

Corrosion casting of the temporal bone: Review of the technique.

The temporal bone has the most sophisticated anatomy of the whole skeleton. Its study is a challenge for students and surgeons. An inverse model of the visually obscured cavities and canals can facilitate better three-dimensional orientation and investigation. This can be made by means of corrosion casting, which is an established technique first documented on the temporal bone at the beginning of the nineteenth century. The prepared specimens are suitable not only for teaching purposes but also for research on the fascinating topography of the osseous labyrinth and the whole temporal bone. Many important studies on temporal bone anatomy are based on this technique. An extensive review of the pertinent literature is provided in relation to each method available.

Optical properties of the human round window membrane.

Optical techniques are effective tools for diagnostic applications in medicine and are particularly attractive for the noninvasive analysis of biological tissues and fluids in vivo. Noninvasive examinations of substances via a fiber optic probe need to consider the optical properties of biological tissues obstructing the optical path. This applies to the analysis of the human perilymph, which is located behind the round window membrane. The composition of this inner ear liquid is directly correlated to inner ear hearing loss. In this work, experimental methods for studying the optical properties of the human round window membrane ex vivo are presented. For the first time, a comprehensive investigation of this tissue is performed, including optical transmission, forward scattering, and Raman scattering. The results obtained suggest the application of visible wavelengths (>400 nm) for investigating the perilymph behind the round window membrane in future.

Improved imaging of cochlear nerve hypoplasia using a 3-Tesla variable flip-angle turbo spin-echo sequence and a 7-cm surface coil.

OBJECTIVE/HYPOTHESIS: Magnetic resonance imaging of the temporal bone has an important role in decision making with regard to cochlea implantation, especially in children with cochlear nerve deficiency. The purpose of this study was to evaluate the usefulness of the combination of an advanced high-resolution T2-weighted sequence with a surface coil in a 3-Tesla magnetic resonance imaging scanner in cases of suspected cochlear nerve aplasia. STUDY DESIGN: Prospective study. METHODS: Seven patients with cochlear nerve hypoplasia or aplasia were prospectively examined using a high-resolution three-dimensional variable flip-angle turbo spin-echo sequence using a surface coil, and the images were compared with the same sequence in standard resolution using a standard head coil. Three neuroradiologists evaluated the magnetic resonance images independently, rating the visibility of the nerves in diagnosing hypoplasia or aplasia. RESULTS: Eight ears in seven patients with hypoplasia or aplasia of the cochlear nerve were examined. The average age was 2.7 years (range, 9 months-5 years). Seven ears had accompanying malformations. The inter-rater reliability in diagnosing hypoplasia or aplasia was greater using the high-resolution three-dimensional variable flip-angle turbo spin-echo sequence (fixed-marginal kappa: 0.64) than with the same sequence in lower resolution (fixed-marginal kappa: 0.06). CONCLUSIONS: Examining cases of suspected cochlear nerve aplasia using the high-resolution three-dimensional variable flip-angle turbo spin-echo sequence in combination with a surface coil shows significant improvement over standard methods.

Highly selective A(1) -adenosine-agonist (2-chloro-N6-cyclopentyladenosine) and reduction of flap necrosis in adipocutaneous flaps in rats.

BACKGROUND: The 2-chloro-N6-cyclopentyladenosine (CCPA) was proven to be a protective factor in ischemic reperfusion injury in myocardium and to reduce the infarct size in the heart. The purpose of this study was to determine whether flap necrosis could be reduced by intravenous administration of CCPA. METHODS: Fifty-six male Wistar rats were divided into 4 experimental groups. An epigastric adipocutaneous flap was raised, and the area of flap necrosis was assessed for all groups on the fifth postoperative day with planimetry software. RESULTS: The control group had a significantly lower rate of flap necrosis than the ischemic control group (p < .05). The nonischemic CCPA group had a significantly lower rate of flap necrosis than the nonischemic control group (p < .05). The ischemic CCPA group had a highly significant (p < .0001) rate of lower flap necrosis than the ischemic control group. CONCLUSION: Our data show that reduction of flap necrosis can be achieved both with and without ischemic periods by intravenous administration of CCPA.

Pyrrolidine dithiocarbamate as an effector and trigger in ischemia-reperfusion injury in adipocutaneous flaps in rats.

BACKGROUND: Immune and inflammatory responses and the regulation of cellular events seem to be major factors in ischemia-reperfusion (I/R) injury. The inhibition of nuclear transcription factor κB (NF-κB) by pyrrolidine dithiocarbamate (PDTC) shows beneficial effects in animal models in various diseases and tissues with respect to I/R injury. If these results from other tissues could be transferred to adipocutaneous flaps in rats, a new approach to pharmacologic preconditioning could be defined for tissue transfer, and PDTC could be a solution as a trigger and effector to ameliorate the aftermath of the I/R injury. METHODS: Fifty-six male WISTAR rats were divided into four experimental groups. An epigastric adipocutaneous flap was raised, and the average flap necrosis was assessed for all groups on the fifth postoperative day using planimetric software. RESULTS: The control group had a significantly lower flap necrosis than the ischemic control group (p < .05). The PDTC nonischemic group had a significantly lower flap necrosis than the ischemic control group (p  =  .005). The ischemic PDTC group had a 10% reduction in flap necrosis that was not significant. CONCLUSION: Our data show that a significant reduction in flap necrosis can be achieved by intravenous application of PDTC.