Bypass de instrumento endodôntico fraturado: relato de caso / Bypass of a fractured endodontic instrument: case report

Introdução: Mesmo com toda evolução tecnológica desses instrumentos, com o desenvolvimento das limas de liga de níquel-titanio (NiTi) e sistemas mecanizados, as fraturas podem ocorrer durante o preparo químico/mecânico. Existem três abordagens mais regulamente aplicadas para solucionar essa intercorrencia: tentativa de remoção do instrumento com ultrassom, tentativa de ultrapassálo (bypass) ou a obturação do segmento. Objetivo: Relatar um caso da técnica de bypass em instrumento fraturado no canal radicular. Descrição do caso: Paciente, sexo feminino, 47 anos, brasileira, sem condições sistêmicas associadas, foi encaminhada à clínica do Curso de Odontologia da UNIFENAS, Divinópolis, Minas Gerais, Brasil, para resolução de fratura de instrumento no canal mésio- vestibular do primeiro molar superior direito (16). Optou-se pelo tratamento pela técnica de bypass, que envolveu as seguintes etapas: anestesia, abertura, utilização de lima C-Pilot #08 para ultrapassar o instrumento fraturado, odontometria, escalonamento regressivo a partir da lima k#20, desinfecção com hipoclorito de sódio 5%, medicação com hidróxido de cálcio por 21 dias, agitação da substância irrigadora e obturação dos canais radiculares. Conclusão: O bypass ao instrumento é uma técnica conservadora, eficaz e uma solução adequada em casos de fratura de limas endodônticas dentro dos canais radiculares. Essa técnica visa preservar o máximo possível da estrutura dental original, evitando procedimentos mais invasivos.(AU)

Introduction: Even with all technological evolution of these instruments, with the development of nickel-titanium alloy (NiTi) files and mechanized systems, fractures can occur during chemical/mechanical preparation. There are three most commonly applie to resolve this complication: attempting to remove the instrument with ultrasound, attempting to bypass it, or obturating the segment. Objective: To report a case of bypass technique in fractured instrument in the root canal. Case description: A 47-year-old female patient from Brazil, with no associated systemic conditions, was referred to the clinic of the Dentistry Course at UNIFENAS, Divinópolis, Minas Gerais, Brazil, for resolution of an instrument fracture in the mesio-vestibular canal of the right upper first molar (16). Treatment was performed using the bypass technique, which involved the following steps: anesthesia, opening, use of a C-Pilot #08 file to bypass the fractured instrument, odontometry, regressive scaling from the k#20 file, disinfection with 5% sodium hypochlorite, medication with calcium hydroxide for 21 days, agitation of the irrigating substance and root canal filling. Conclusion: Instrument bypass is a conservative, effective technique and an adequate solution in cases of endodontic file fracture within root canals. This technique aims to preserve as much of the original tooth structure as possible, avoiding more invasive procedures.(AU)

Digital X-ray Machine Carestream DRX-NOVA Fault Maintenance / 中国医疗器械杂志

OBJECTIVE@#To analyze the malfunction and maintenance process of Carestream digital X-ray machine DRX-NOVA for reference.@*METHODS@#The fault of Carestream digital X-ray machine DRX-NOVA in 2011-2021 was summarized, the fault types were classified, and the maintenance process was summarized.@*RESULTS@#Fault types can be divided into three categories, each of which has its own characteristics and specific solutions.@*CONCLUSIONS@#It is necessary to master the principle of equipment to repair all kinds of equipment failures. Repair the machine should be careful, comprehensive consideration of the cause of the failure. To correctly understand and analyze the operation of the machine under normal conditions, we can accurately analyze the cause of failure, so that we can really solve the problem.

Endodontic file separation and its management among dentists in Punjab, Pakistan: a cross-sectional study

The study aimed to find the incidence and awareness of endodontic instrument separation and its management among dental house officers, postgraduate trainees, demonstrators, consultants, and general dentists. Methods: This online questionnaire-based cross-sectional study was conducted with the approval of the IRB in private and public dental hospitals and dental clinics in Punjab. The authors developed the survey tool, which comprises 24 closed-ended items regarding demographics, the incidence of file separation, and awareness about its management. The data were analyzed using IBM SPSS version 24. The Chi-Square Test was used to compare percentages of categorical variables. Results: Postgraduate trainees experienced the most instrument separations (43.6%), made the most retrieval attempts (49.2%), and experienced the most secondary errors during retrieval (52.1%) (p<0.001). Around four out of ten respondents always informed the patients (39.6%) and department (41.6%) about errors. Manual files (69.8%), stainless steel files (75.8%), and short files (60.4%) were more frequently separated, and the most frequent cause was older fatigue files (57.7%). Manual files were more frequently broken in public dental institutes (p=0.003). Two-thirds of the file separations (72.5%) occurred during cleaning and shaping in the apical third of molars (65.1%), especially in mesiolingual canal (56.4%). Bypass attempt was the most common in symptomatic teeth (47.7%). Conclusions: Preventive approaches such as limiting file reuse and constructing a glide path can reduce the occurrence of file separation. Operators should be familiar with the number of uses of the instrument before fatigue and should be trained through workshops and refresher courses

The influence of a doppler ultrasound in arteriovenous fistula for dialysis failure related to some risk factors / Influência da Ultrassonografia Doppler nas Falhas de Fístulas Arteriovenosas de Diálise Relacionada a Alguns Fatores de Risco

ABSTRACT Introduction: The increasing prevalence of chronic kidney disease has increased the demand for arteriovenous fistula (AVF) care. The objective of this study was to assess the relationship between some risk factors for AVF failure (advanced age, female sex, diabetes, obesity, central venous catheter, previous fistula, and hospitalization) and having a Doppler ultrasound performed preoperatively. Methods: A prospective study was performed with 228 dialysis patients from Imperatriz, Maranhão. Half of the sample was randomly selected to receive preoperative Doppler ultrasound and the other half did not, from the period of October 2016 to September 2018. Results: There were 53 total failures corresponding to 23.2% of our sample, which is almost double that of the patients in the clinical group. Considering the failures and risk factors associated with the overall sample, there was a statistically significant association between a central venous catheter on the same side of the AVF with P = 0.04 (Odds Ratio 1.24) and obesity with P = 0.05 (Odds Ratio 1.36), which was not repeated in the Doppler ultrasound group individually. There was no statistically significant difference between the Doppler group and clinical group with respect to the amount of days of previous AVF hospitalization and failure. Conclusions: We concluded that the reduction of failures with an introduction of the Doppler was statistically significant in the overall sample, but establishing a relationship between specific risk factors and failure was only possible with two of the risk factors in the study - obesity and central venous catheter on the same side of the AVF.

RESUMO Introdução: A crescente prevalência de doença renal crônica aumentou a demanda por confecção de fístula arteriovenosa (FAV). O objetivo do presente estudo foi avaliar a relação entre alguns fatores de risco para falha da FAV (idade avançada, sexo feminino, diabetes, obesidade, cateter venoso central, fístula prévia e hospitalização) e a realização de ultrassonografia Doppler no pré-operatório. Métodos: Estudo prospectivo com 228 pacientes em diálise em Imperatriz, MA. Metade da amostra foi randomizada para receber ultrassonografia Doppler no pré-operatório. A outra metade dos pacientes não foi submetido a exame ultrassonográfico. O estudo incluiu pacientes atendidos no período de outubro de 2016 a setembro de 2018. Resultados: Houve 53 falhas (23,2%) em nossa amostra, quase o dobro do número dos pacientes no grupo clínico. Considerando as falhas e os fatores de risco associados à amostra geral, houve associação estatisticamente significativa entre catéter venoso central do mesmo lado da FAV (P = 0,04; Razão de Chances: 1,24) e obesidade (P = 0,05; Razão de Chances: 1,36), o que não foi reproduzido no grupo de ultrassonografia Doppler individualmente. Não houve diferença estatisticamente significativa entre o grupo Doppler e o grupo clínico em relação à quantidade de dias de internação e falha da FAV. Conclusões: A redução de falhas com a introdução do Doppler foi estatisticamente significativa na amostra geral, mas só foi possível estabelecer uma relação entre fatores de risco específicos e falha em dois dos fatores estudados, obesidade e catéter venoso central no mesmo lado da FAV.

Universal masking during covid-19 pandemic - current evidence and controversies

ABSTRACT The emergence of coronavirus disease 19 pandemic and novel research on the high transmissibility of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has raised controversies over the use of face masks to prevent community transmission. Specific regulations need to be fulfilled to use a face mask as part of the personal protective equipment and high quality of evidence supporting its use to prevent respiratory viral infections, including SARS-CoV-2, is lacking. However, its widespread use is becoming a standard practice in some countries and discrepancies between health authorities on their policy have led to controversy. The aim of this review is to provide an outlook on recent research in this matter and areas of opportunity.

Instrumentação reciprocante em canal mésiovestibular de molar superior após fratura de lima endodôntica: relato de caso / Reciprocal instrumentation in the mesiobuccal canal of the upper molar after endodontic file fracture: case report

Objetivo: reportar um caso clínico de ultrapassagem de instrumento endodôntico fraturado em terço médio de canal mésiovestibular de molar superior permanente, utilizando a técnica de instrumentação reciprocante associada à instrumentação convencional manual e ao gel de E.D.T.A. 24%. Relato de caso: paciente do sexo masculino, 24 anos, normossistêmico, compareceu ao consultório odontológico privado com queixa de dor espontânea e encaminhamento para tratamento endodôntico do dente 17. O diagnóstico foi pulpite irreversível sintomática com indicação de tratamento endodôntico primário. A lima principal escolhida foi a Reciproc® R25 M-wire (VDW), que, durante a instrumentação do canal mésiovestibular, sofreu fratura por torção em terço médio, inviabilizando a continuação em direção apical. Considerações finais: a associação da técnica convencional manual das limas Hedströen com a técnica reciprocante de corte reverso da lima Wave One® Gold Primary e o uso do gel de E.D.T.A. 24% permitiram ultrapassagem do fragmento de lima fraturado em terço médio do canal mésiovestibular do dente 17, promovendo selamento hermético, limpeza, modelagem e obturação satisfatórias.(AU)

Objective: to report a clinical case of a fractured endodontic instrument in the middle third of the permanent maxillary molar maxillary canal using the technique instrumentation reciprocation with technique to conventional manual instrumentation and the E.D.T.A. 24% gel. Case report: a 24-yearold normosystemic male patient came to the private dental office complaining of spontaneous pain and referred for endodontic treatment of tooth 17. The diagnosis was irreversible symptomatic pulpitis with indication for primary endodontic treatment. The main file chosen was the Reciproc® R25 M-wire (VDW), which during the instrumentation of the mesiobuccal canal suffered torsional fracture in the middle third, preventing continuity in the apical direction. Final considerations: the association of the conventional manual Hedströen file technique with the reciprocal reverse cutting technique of the Wave One® Gold Primary file and the use of E.D.T.A. 24% gel allowed the fractured file fragment to be overcome in the middle third of the mesiobuccal canal of tooth 17, promoting hermetic sealing, cleaning, modeling and satisfactory filling. (AU)

Summary of Fault Maintenance Experience of Multifunctional Digital Flat Plate Radiography System-Carestream DR7500 / 中国医疗器械杂志

This paper is a summary of the three types of faults that have occurred in the recent years in the Carestream DR7500:hardware failure, software failure, and communication failure. The specific cases of three types of faults are introduced in a case-by-case basis.

Analysis of Performance of the MINItrace Cyclotron before and after Upgrade / 中国医疗器械杂志

OBJECTIVE@#To compare the performance of the GE cyclotron MINItrace system before and after the upgrade.@*METHODS@#The upgrade of the MINItrace system included replacing the silver target with the Nb syetem and adopting the latest RF control and management system and lastest ion source system.The failrue rate and production efficiency were retrospectively analyzed before and after the upgrade.@*RESULTS@#After the upgrade, the cyclotron failure rate decreased by 86.2%, the average capacity increased by 45%.@*CONCLUSIONS@#After the upgrade of MINItrace cyclotron, the failure rate is sharply reduced, and the production efficiency is grately improved.

Fractura intravascular de un catéter arterial: una complicación poco común pero real / Intravascular fracture of an arterial catheter: an uncommon nevertheless real complication

Arterial catheterization is a common procedure performed for invasive blood pressure as well as cardiac output monitoring and blood sampling for analysis. The fracture or embolization of arterial catheters are rare but serious complications, and may cause vascular thrombosis or occlusion. Ultrasound can be used to identify the intravascular fragment, however their removal may be complex. The authors report a case of intra-arterial catheter fracture in the radial artery, confirmed by ultrasound and surgically removed. This case may alert to be aware of this complication when using this invasive method, helping to prevent future complications for patients.

La introducción de un catéter arterial es un procedimiento realizado regularmente para evaluar la presión arterial invasiva, el gasto cardíaco y tomar muestras de sangre para su análisis. La fractura y la embolización de los catéteres arteriales son complicaciones poco frecuentes pero graves y pueden causar trombosis u oclusión de la arteria. La ecografía puede usarse para identificar el fragmento intravascular, pero la extracción puede ser compleja. Presentamos un caso de fractura intravascular del catéter de la arteria radial confirmada por ecografía y extirpada quirúrgicamente. Este caso señala la necesidad de prestar atención a esta complicación cuando se usa el monitoreo invasivo, para evitar complicaciones futuras para los enfermos.

Incidence of thrombotic events and complications associated to inferior vena cava filters in patients with and without anticoagulation therapy / Incidencia de eventos trombóticos y complicaciones asociadas al uso de filtros de vena cava en pacientes en pacientes con o sin terapia anticoagulante

Abstract Objective: Anticoagulation is the primary management to prevent venous thromboembolism; inferior vena cava filters (IVCFs) provide a mechanical prophylactic alternative when anticoagulation is contraindicated. The aim of this study was to evaluate in IVCF patients, whether the initiation of anticoagulation therapy is associated with decreased rates of recurrent thrombotic events and device-related complications. Methods: This was a retrospective review of patients that underwent insertion of IVCF. Subjects with IVCF were studied in two groups: those initiated on anticoagulation (A) and without anticoagulation (NA). Variables as indications for IVCF, anticoagulation, recurrence of thrombosis, complications, and reinterventions were examined. Results: From April 2007 to March 2014, 54 patients underwent IVCF placement; (61% of females), with mean age of 54 years (standard deviation ± 19). 28 (52%) were initiated on anticoagulation, during a mean follow-up period of 28 months, five experienced recurrent thrombosis and three were on the A group (p=0.5); when comparing patients that developed post-thrombotic syndrome, seven were in the A group and seven in the NA. Two patients with IVC rupture were in the A group (p=0.5), and the only case of IVCF migration occurred in the A group. 11 (20%) patients died from comorbidities nonrelated to the device or procedure (four in the A cohort). Conclusions: Patients with IVCF on anticoagulation have equivalent rates of thrombotic events and device-related complications than those patients NA.

Resumen Objetivo: La anticoagulación es la terapia de elección para la prevención de tromboembolismo venoso; los filtros de vena cava inferior (FVCI) proveen una alternativa mecánica profiláctica cuando la anticoagulación está contraindicada. El objetivo de este estudio fue evaluar si la terapia anticoagulante se asocia con una tasa menor de eventos trombóticos recurrentes y complicaciones relacionadas con el dispositivo. Métodos: Los pacientes fueron categorizados en dos grupos: Aquellos a los que se les inicio anticoagulación (A) y aquellos que no (NA). Variables tales como indicación de la colocación del filtro, anticoagulación, recurrencia de trombosis y complicaciones fueron examinadas. Resultados: De abril de 2007 a marzo 2014, a 54 pacientes se les coloco un filtro (61% fueron mujeres), con una media de edad de 54 años [Desviación estándar (DE) ±19. Veintiocho (52%) fueron iniciados en anticoagulación y durante un seguimiento de 28 meses, 5 pacientes experimentaron recurrencia de trombosis, 3 en el grupo A (p=0.5). Al comparar los pacientes que desarrollaron síndrome posflebítico, 7 pertenecieron al grupo A y 7 al grupo NA. Dos pacientes con ruptura de vena cava pertenecieron al grupo A (p=0.5) y el único caso de migración del dispositivo ocurrió en el grupo A. Once (20%) pacientes fallecieron debido a comorbilidades no relacionadas con el dispositivo o el procedimiento. Conclusión: Pacientes con FVCI en anticoagulación tienen tasas de eventos trombóticos y complicaciones asociadas a los dispositivos equivalentes a aquellos pacientes sin anticoagulación.

Iatrogenic foreign body in urinary bladder: Holmium laser vs. Ceramic, and the winner is

ABSTRACT Introduction Urological surgery is estimated to be the third most common cause of iatrogenic-retained foreign bodies 1. Presentation A 76-year old man was undergoing a transurethral resection of bladder tumor with a 26-Ch continuous flow resectoscope (Karl Storz, Germany). Before starting resection, a detachment of resectoscope sheath tip was noted. The ceramic tip was free-floating in the bladder lumen, and it would not fit within the sheath, making direct extraction using the loop impossible. An attempt was made to break it with a stone punch, but it was unsuccessful due to impossibility of closing it in the branches. Therefore, we decided to fragment the tip with holmium laser (RevoLix®, LISA Laser products, Germany), using an 800-micron, front-firing fiber. Laser device was settled at with 2.5 J energy and 5 Hz frequency. Ceramic appeared very hard, but it was difficult to carry on breaking with this setting because of tip retropulsion. Then, laser setting was switched to lower energy and higher frequency (1 J and 13 Hz). This setting guaranteed the same power of 13 W, but with minimal retropulsion. Results Tip was fragmented against the posterior bladder wall in seven pieces, which were retrieved trough the outer sheath. A total 5.62 kJ were used to fragment it. At the end, superficial lesions of the posterior bladder wall were highlighted. Surgical time was 55 minutes. Patient was discharged home next day without problems. Conclusions Holmium laser fragmentation is a safe and effective approach to remove foreign bodies from the bladder.

Circular saw misuse is related to upper limb injuries: a cross-sectional study

OBJECTIVES: Machinery injuries account for a substantial share of traumatic upper limb injuries (TULIs) affecting young active individuals. This study is based on the hypothesis that there is an important relationship between the improper use of power saws and TULIs. The aim of the study is to assess the prevalence and epidemiology of TULIs caused by power saws and determine the risks related to power saw use. METHODS: A cross-sectional evaluation of medical records from a two-year period was performed. Patients sustaining TULIs related to power saws were analyzed. Data on the epidemiology, site of injury, mechanism of trauma, technical specifications of the tool, cutting material, personal protective equipment, time lost and return to work were obtained. RESULTS: A database search retrieved 193 TULI records, of which 104 were related to power saws. The majority of patients were male (102/104; 98.1%), right-handed (97/104; 93.3%), and manual workers (46/104; 44.2%), with an average age of 46.8 years. The thumb was the most frequently injured site (32/93; 34.4%). Most of the injuries were caused by manual saws (85/104; 81.7%), and masonry saws accounted for 68.2% (58/85) of the cases. Masonry saws improperly used for woodwork resulted in 86.2% (50/58) of the injuries. TULI caused by masonry saws was 5 times higher in manual workers than in other patients. In addition, masonry saws had a risk of kickback 15 times higher than that of other saws, and the risk of injury increased by 5.25 times when the saws were used improperly for wood cutting. CONCLUSIONS: The profile of TULIs related to power saws was demonstrated and was mainly associated with manual saws operated by manual workers that inappropriately used masonry saws for woodworking.

The Present and Future of Vagus Nerve Stimulation

Epilepsy is one of the major chronic neurological diseases affecting many patients. Resection surgery is the most effective therapy for medically intractable epilepsy, but it is not feasible in all patients. Vagus nerve stimulation (VNS) is an adjunctive neuromodulation therapy that was approved in 1997 for the alleviation of seizures; however, efforts to control epilepsy by stimulating the vagus nerve have been studied for over 100 years. Although its exact mechanism is still under investigation, VNS is thought to affect various brain areas. Hence, VNS has a wide indication for various intractable epileptic syndromes and epilepsy-related comorbidities. Moreover, recent studies have shown anti-inflammatory effects of VNS, and the indication is expanding beyond epilepsy to rheumatoid arthritis, chronic headaches, and depression. VNS yields a more than 50% reduction in seizures in approximately 60% of recipients, with an increase in reduction rates as the follow-up duration increases. The complication rate of VNS is 3–6%, and infection is the most important complication to consider. However, revision surgery was reported to be feasible and safe with appropriate measures. Recently, noninvasive VNS (nVNS) has been introduced, which can be performed transcutaneously without implantation surgery. Although more clinical trials are being conducted, nVNS can reduce the risk of infection and subsequent device failure. In conclusion, VNS has been demonstrated to be beneficial and effective in the treatment of epilepsy and various diseases, and more development is expected in the future.

The Present and Future of Vagus Nerve Stimulation

Epilepsy is one of the major chronic neurological diseases affecting many patients. Resection surgery is the most effective therapy for medically intractable epilepsy, but it is not feasible in all patients. Vagus nerve stimulation (VNS) is an adjunctive neuromodulation therapy that was approved in 1997 for the alleviation of seizures; however, efforts to control epilepsy by stimulating the vagus nerve have been studied for over 100 years. Although its exact mechanism is still under investigation, VNS is thought to affect various brain areas. Hence, VNS has a wide indication for various intractable epileptic syndromes and epilepsy-related comorbidities. Moreover, recent studies have shown anti-inflammatory effects of VNS, and the indication is expanding beyond epilepsy to rheumatoid arthritis, chronic headaches, and depression. VNS yields a more than 50% reduction in seizures in approximately 60% of recipients, with an increase in reduction rates as the follow-up duration increases. The complication rate of VNS is 3–6%, and infection is the most important complication to consider. However, revision surgery was reported to be feasible and safe with appropriate measures. Recently, noninvasive VNS (nVNS) has been introduced, which can be performed transcutaneously without implantation surgery. Although more clinical trials are being conducted, nVNS can reduce the risk of infection and subsequent device failure. In conclusion, VNS has been demonstrated to be beneficial and effective in the treatment of epilepsy and various diseases, and more development is expected in the future.

Research on Fault Risk Identification and Control of CT Simulator Based on FMEA / 中国医疗器械杂志

OBJECTIVE@#To explore the high-risk fault risk of CT simulator and the main causes of the risk, and to put forward effective risk management strategies.@*METHODS@#The failure mode and effect analysis method was used to identify and control the operational fault risk of CT simulator.@*RESULTS@#5 major fault components, 8 fault failure models and 17 failure causes were analyzed. The top 5 failure causes are:anode target surface burn caused by direct scanning without warming up the tube (590.4), tube failure (518.2), burnout of joints caused by aging of high voltage cables (424.2), motor carbon brush wear (304.8) and belt break (296.4).@*CONCLUSIONS@#The failure mode and effect analysis method can effectively identify the risk of equipment failure, and thus specifically formulate risk management and control measures to ensure the normal operation of equipment and the safety of doctors and patients.

General Troubleshooting and Preventive Maintenance of the Digestive Electron Microscope System / 中国医疗器械杂志

OBJECTIVE@#Improve the integrity of the digestive electron microscope equipment and reduce the cost of equipment failure maintenance.@*METHODS@#By studying the composition and function of the digestive electron microscope system and analyzing the causes of common faults, a targeted preventive maintenance plan is developed, equipment users are graded, and a training system is established.@*RESULTS@#The user of the device can skillfully analyze the cause of the malfunction and timely deal with the sudden failure of the diagnosis and treatment, thereby reduce the risk of diagnosis and treatment and the investment in hospital maintenance.@*CONCLUSIONS@#Through the analysis and processing of the digestive electron microscope system, point detection leakage, grading training, preventive maintenance can significantly improve the equipment integrity rate, reduce the risk of clinical diagnosis and treatment, effectively reduce the number of equipment failures, and reduce maintenance costs.

Feasibility of Revision Cochlear Implant Surgery for Better Speech Comprehension

BACKGROUND AND OBJECTIVES: The purpose of this study was to evaluate the efficacy of revision cochlear implant (CI) surgery for better speech comprehension targeting patients with low satisfaction after first CI surgery. SUBJECTS AND METHODS: Eight patients who could not upgrade speech processors because of an too early CI model and who wanted to change the whole system were included. After revision CI surgery, we compared speech comprehension before and after revision CI surgery. Categoies of Auditory Performance (CAP) score, vowel and consonant confusion test, Ling 6 sounds, word and sentence identification test were done. RESULTS: The interval between surgeries ranged from eight years to 19 years. Same manufacturer’s latest product was used for revision surgery in six cases of eight cases. Full insertion of electrode was possible in most of cases (seven of eight). CAP score (p-value=0.01), vowel confusion test (p-value=0.041), one syllable word identification test (p-value=0.026), two syllable identification test (p-value=0.028), sentence identification test (pvalue=0.028) had significant improvement. Consonant confusion test (p-value=0.063), Ling 6 sound test (p-value=0.066) had improvement but it is not significant. CONCLUSIONS: Although there are some limitations of our study design, we could identify the effect of revision (upgrade) CI surgery indirectly. So we concluded that if patient complain low functional gain or low satisfaction after first CI surgery, revision (device upgrade) CI surgery is meaningful even if there is no device failure.