Metachronous carcinoma at the colostomy site after abdominoperineal resection of rectal cancer: a case report

Metachronous carcinoma at the colostomy site is very rare after abdominoperineal resection. A 53-year-old male patient underwent an abdominoperineal resection 6 years earlier for rectal cancer developed metachronous carcinoma at the site of stoma. A portion of the colon, including the stoma and the surrounding skin, was resected and a new stoma was created in the transverse colon. Although the occurrence of carcinoma at the stoma site is a rare condition, careful observation for the stoma and colonoscopy for surveillance are necessary.

The characteristics of the patients who visited the emergency department with fever, after the chronification of COVID-19 pandemic

Objective@#This study examined the characteristics of patients visiting the emergency department (ED) with fever after the chronification of the coronavirus disease 2019 (COVID-19) pandemic. @*Methods@#This retrospective observational study analyzed the medical records of patients who visited the ED with fever from May 1 to October 31, 2021, and the corresponding period in 2019. This study was conducted at a single center in Seoul, Korea. @*Results@#There was no statistical difference in the comorbidities of the patients of the two groups: the AC (after the COVID-19 pandemic) group and the BC (before the COVID-19 pandemic) group. As for the level of consciousness at the time of ED arrival, there was a significantly larger decrease in consciousness (verbal response or less) in the AC group than in the BC group (P=0.002). In the case of the National Early Warning Score (NEWS), the proportion was higher in the AC group in the moderate-risk and high-risk groups (P=0.003). The median time from symptom onset to ED arrival was 15.7 hours in the BC group and 13.8 hours in the AC group, and there was no significant difference (P=0.137). When leaving the ED, the AC group had a higher admission rate to the ward and intensive care unit than the BC group. There was no statistical difference in the in-hospital mortality between the two groups (2.9% and 2.4%, respectively; P=0.62). @*Conclusion@#Patients who visited the emergency room with fever after one year of the COVID-19 pandemic showed a similar time from symptom onset to ED arrival compared to patients who visited before the COVID-19 pandemic. In addition, there was no difference in in-hospital mortality among these patients compared to those with fever before the COVID-19 pandemic.

Professional self-concept, self-leadership, job stress and fatigue on clinical competence of dental hygienists / 대한구강보건학회지

Objectives@#This study examines the relationship of dental hygienists’ professional self-concept, self-leadership, job stress, and fatigue with their clinical competence in order to identify factors that can improve clinical competence. This study is intended to provide basic information to develop educational programs for dental hygienist’s clinical competence. @*Methods@#The self-administered questionnaire survey was conducted with 243 dental hygienists working at dental clinics in Gwangju and Jeonnam from August 14, 2017 to September 9, 2017.The data regarding the general characteristics, professional self-concept, self-leadership, job stress and fatigue, and clinical competence were collected, and analyzed through independent t-tests, one-way analysis of variance (ANOVA), Pearson’s correlation coefficient, and multiple regression analysis using the SPSS Windows ver. 22.0. @*Results@#High professional self-concept (r=0.54) and self-leadership(r=0.48) were associated with high clinical competence. High self-leadership (r=0.53) was associated with high professional selfconcept. High fatigue(r=―0.21) was associated with low professional self-concept(P<0.01). The highest factor influencing clinical competence was professional self-concept, followed by selfleadership, total clinical experience, education level, and fatigue (P<0.05). @*Conclusions@#Based on the findings, it is necessary to develop educational programs which can improve autonomy and develop professionalism to enhance clinical competence in consideration of work experience and educational levels in dental hygienists.

Improved Detection of Urolithiasis Using High-Resolution Computed Tomography Images by a Vision Transformer Model / 대한배뇨장애요실금학회지

Purpose@#Urinary stones cause lateral abdominal pain and are a prevalent condition among younger age groups. The diagnosis typically involves assessing symptoms, conducting physical examinations, performing urine tests, and utilizing radiological imaging. Artificial intelligence models have demonstrated remarkable capabilities in detecting stones. However, due to insufficient datasets, the performance of these models has not reached a level suitable for practical application. Consequently, this study introduces a vision transformer (ViT)-based pipeline for detecting urinary stones, using computed tomography images with augmentation. @*Methods@#The super-resolution convolutional neural network (SRCNN) model was employed to enhance the resolution of a given dataset, followed by data augmentation using CycleGAN. Subsequently, the ViT model facilitated the detection and classification of urinary tract stones. The model’s performance was evaluated using accuracy, precision, and recall as metrics. @*Results@#The deep learning model based on ViT showed superior performance compared to other existing models. Furthermore, the performance increased with the size of the backbone model. @*Conclusions@#The study proposes a way to utilize medical data to improve the diagnosis of urinary tract stones. SRCNN was used for data preprocessing to enhance resolution, while CycleGAN was utilized for data augmentation. The ViT model was utilized for stone detection, and its performance was validated through metrics such as accuracy, sensitivity, specificity, and the F1 score. It is anticipated that this research will aid in the early diagnosis and treatment of urinary tract stones, thereby improving the efficiency of medical personnel.

Transfer Learning for Effective Urolithiasis Detection / 대한배뇨장애요실금학회지

Purpose@#Urolithiasis is a common disease that can cause acute pain and complications. The objective of this study was to develop a deep learning model utilizing transfer learning for the rapid and accurate detection of urinary tract stones. By employing this method, we aim to improve the efficiency of medical staff and contribute to the progress of deep learning-based medical image diagnostic technology. @*Methods@#The ResNet50 model was employed to develop feature extractors for detecting urinary tract stones. Transfer learning was applied by utilizing the weights of pretrained models as initial values, and the models were fine-tuned with the provided data. The model’s performance was evaluated using accuracy, precision-recall, and receiver operating characteristic curve metrics. @*Results@#The ResNet-50-based deep learning model demonstrated high accuracy and sensitivity, outperforming traditional methods. Specifically, it enabled a rapid diagnosis of the presence or absence of urinary tract stones, thereby assisting doctors in their decision-making process. @*Conclusions@#This research makes a meaningful contribution by accelerating the clinical implementation of urinary tract stone detection technology utilizing ResNet-50. The deep learning model can swiftly identify the presence or absence of urinary tract stones, thereby enhancing the efficiency of medical staff. We expect that this study will contribute to the advancement of medical imaging diagnostic technology based on deep learning.

Usefulness of Early Warning Scores, ROX index, and CURB-65 in the prognostic evaluation of patients with COVID-19

Objective@#Early identification of COVID-19 in patients is important to prevent significant worsening of the disease. This study was undertaken to verify whether MEWS (Modified Early Warning Score), NEWS(National Early Warning Score), ROX index, and CURB-65, which are early diagnostic tools for severe respiratory diseases, could be applied to patients visiting the emergency room for COVID-19. @*Methods@#This retrospective observational study included patients who visited an emergency medical center from September 1 to October 31, 2020, and from January 1 to February 28, 2021. Based on the vital signs and blood tests during the emergency room visit, severity evaluation tools and early diagnostic tools for severe cases were used and compared according to their area under the curve (AUC) values. The primary outcome was in-hospital mortality, while the secondary outcomes were intensive care unit admission rate and the need for mechanical ventilation based on these four tools (MEWS, NEWS, ROX index, and CURB-65). @*Results@#A total of 667 patients were analyzed. No significant difference was determined between the non-survivor group and survivor group in the MEWS values (P=0.13), but statistically significant differences were observed for NEWS (5 vs. 1, P<0.05), CURB-65 (2 vs. 1, P<0.05), and ROX index (16.61 vs. 23.1, P<0.01). The AUC value of NEWS for death prediction indicated a good predictive power at 0.80, while that of MEWS showed a low predictive power at 0.57, which was statistically significant. Moreover, the AUC values of CURB-65 and ROX index did not differ significantly from values obtained for NEWS. @*Conclusion@#As early diagnostic tools for predicting death in COVID-19 patients, NEWS, ROX index, and CURB-65 showed excellent discrimination ability, whereas MEWS showed statistically and significantly lower discrimination ability.

Neurotrauma Clinical Practice Guidelines Committee of the Korean Neurotraumatology Society: A Review of a Group That Writes and Inherits the Thoughts and Will of the Society / 대한신경손상학회지

The Neurotrauma Clinical Practice Guidelines Committee of the Korean Neurotraumatology Society (KNTS-NCPGC) is developing clinical guidelines for neurotrauma in line with the capabilities of the Korean Neurotraumatology Society, which is leading pioneering development in the field of neurosurgery. From the mid-1990s, the KNTS-NCPGC has been working to develop guidelines and disseminate evidence-based medicine, including the development of Korean guidelines for the management of severe head injuries and active participation in the Clinical Practice Guidelines Committee of the Korean Academy of Medical Sciences. The KNTS-NCPGC strives to write and inherit the will of the society through the development of clinical practice guidelines, which are one of the outcomes representing professionalism and public interest and can be expressed in terms of “trust” and “best.” In this review, the history and achievements of KNTS-NCPGC, the status of the ongoing development of guidelines, and the perspectives of the committee are covered.

A Radiological Assessment of Chronic Subdural Hematomas / 대한신경손상학회지

Chronic subdural hematoma (CSDH), which generally occurs in elderly patients, is a frequently diagnosed condition in neurosurgical departments. Computed tomography (CT) and magnetic resonance imaging (MRI) are the most preferred diagnostic modalities for CSDH assessment. With early diagnosis and adequate management, CSDH may show favorable prognosis in majority of the patients; however, recurrence after surgery can occur in a significant number of patients. The recently increasing number of CSDH studies could reveal the prognostic factors affecting CSDH recurrence. Particularly, radiological characteristics regarding the internal architecture of CSDH are considered closely associated with recurrence in surgically treated CSDH patients. In this literature review, we evaluated the various diagnostic modalities of CSDH and its radiological characteristics on CT and MRI. Furthermore, we summarized the prognostic factors of recurrence for the hematoma type based on the radiological findings.

Salty taste: the paradoxical taste

Taste is a basic sensation to get attracted toward nutritious foods or avoid possible harmful substances. The basic taste qualities in humans consist of sweet, bitter, umami, salty, and sour. Basically, sweet and umami tastes make food attractive, whereas bitter and sour tastes make it avoidable. Salty taste comprises basic salty and high salt taste.The basic salty taste is known as amiloride-sensitive salty taste, which is inhibited by amiloride, but the high salt taste is not sensitive to amiloride. Moreover, high salt taste can also cause avoidance behavior in human beings. Sodium, one of the most important cations in the body fluids of vertebrates, controls the volume of total body fluids and is a risk factor for cardiovascular diseases, such as hypertension. The concentration of sodium in body fluids must be under delicate control. A distinction between the salty taste and high salt taste would be a contributing mechanism to control the volume and/or osmolarity of body fluids.

Development of Nutritional Biochemistry Learning Goals and Core Competencies in the Dental Hygiene Curriculum / 치위생과학회지

Background@#In the dental hygiene curriculum, efforts are being made to introduce an integrated curriculum based on the competency of a dental hygienist. Because there is a connection and overlap in learning contents between Dental Nutrition and Oral Biochemistry, which are basic dental hygiene subjects, it is possible to integrate these two subjects. This study aims to derive Nutritional Biochemistry as an integrated curriculum for Dental Nutrition and Oral Biochemistry, and to develop learning goals and competencies for Dental Nutritional Biochemistry. @*Methods@#The learning contents of the integrated curriculum were composed by referring to the contents of the Dental Nutrition and Oral Biochemistry textbooks, and learning goals were derived from the learning contents. Moreover, competency was developed by analyzing the duties of a dental hygienist that can be performed through the learning goals. The Delphi survey was conducted twice to verify the content validity ratio (CVR) of the competence and the learning goal of the integrated curriculum. @*Results@#In the first Delphi survey, the CVR for two competencies was 0.56 or higher. Moreover, it was revised based on expert’s opinions, and as a result of the second Delphi survey after the revision, the CVR was either increased or maintained. Eighty-five learning goals were derived by referring to the textbook. According to CVR and expert opinions, after the first Delphi survey, the number of learning goals was reduced to 69. After the second Delphi survey, 68 learning goals were finally derived. @*Conclusion@#The development process of the integrated curriculum conducted in this study can be utilized for integration between subjects in basic dental hygiene.

Primary Mucinous Adenocarcinoma of the Lower Eyelid

Purpose@#We report a case of a primary mucinous adenocarcinoma of the lower eyelid diagnosed in patient with a painless mass.Case summary: A 62-year-old male visited our clinic with a painless mass of the left lower eyelid of increasing the size for 2 months. Orbital computed tomography and magnetic resonance imaging revealed an approximately 2 cm well-defined ovoid, homogeneous enhancing mass in the left lower eyelid. A biopsy was performed under general anesthesia, and histopathologic examination confirmed mucinous adenocarcinoma. Final diagnosis was made as primary mucinous adenocarcinoma since torso positron emission tomography and computed tomography found no abnormal findings and extensive resection was performed for complete resection of the tumor. @*Conclusions@#Primary mucinous adenocarcinoma that occurs in the eyelid is a very rare malignant tumor, and a systemic examination to determine whether it is metastatic is essential, and due to its high local recurrence, regular follow-up after extensive resection is required.

Learning Curve in Phaco Chop Cataract Surgery Using an Illuminated Chopper

Purpose@#To confirm that the phaco chop method using an illuminated chopper (iChopper; Oculight, Seongnam, Korea) can reduce cataract surgery complications, and that even beginners can safely and effectively perform phaco chop. @*Methods@#We retrospectively analyzed the medical records of the first 30 phaco chop cases using illuminated chopper of four cataract surgeons. Four ophthalmologists had a variety of empirical backgrounds, from those who have experienced more than 10,000 cataract surgery, to beginners who have experienced 20 cataract surgery. @*Results@#Of the total 120 eyes, two eyes (1.67%) had posterior capsule rupture. The chopping method was changed from phaco chop to stop and chop in three eyes (2.5%) including one eye with brown cataract with pseudoexofoliation syndrome and two eyes with nuclear opacity grade ≥5. @*Conclusions@#The rates of posterior capsule rupture of phaco chop using an illuminated chopper were very low in four surgeons with various experiences and who became proficient shortly in phaco chop.

Mean and Variability of Lipid Measurements and Risk for Development of Subclinical Left Ventricular Diastolic Dysfunction

Background@#Subclinical left ventricular diastolic dysfunction (LVDD) is an emerging consequence of increased insulin resistance, and dyslipidemia is one of the few correctable risk factors of LVDD. This study evaluated the role of mean and visit-to-visit variability of lipid measurements in risk of LVDD in a healthy population. @*Methods@#This was a 3.7-year (interquartile range, 2.1 to 4.9) longitudinal cohort study including 2,817 adults (median age 55 years) with left ventricular ejection fraction >50% who underwent an annual or biannual health screening between January 2008 and July 2016. The mean, standard deviation (SD), coefficient of variation (CV), variability independent of the mean (VIM), and average real variability of total cholesterol, low-density lipoprotein cholesterol (LDL-C), high-density lipoprotein cholesterol (HDL-C), apolipoprotein B (apoB), non-HDL-C, and triglycerides were obtained from three to six measurements during the 5 years preceding the first echocardiogram. @*Results@#Among the 2,817 patients, 560 (19.9%) developed LVDD. The mean of no component of lipid measurements was associated with risk of LVDD. CV (hazard ratio [HR], 1.35; 95% confidence interval [CI], 1.10 to 1.67), SD (HR, 1.27; 95% CI, 1.03 to 1.57), and VIM (HR, 1.26; 95% CI, 1.03 to 1.55) of LDL-C and all the variability parameters of apoB were significantly associated with development of LVDD. The association between CV-LDL and risk of LVDD did not have significant interaction with sex, increasing/decreasing trend at baseline, or use of stain and/or lipid-modifying agents. @*Conclusion@#The variability of LDL-C and apoB, rather than their mean, was associated with risk for LVDD.

Do-It-Yourself Open Artificial Pancreas System in Children and Adolescents with Type 1 Diabetes Mellitus: Real-World Data

Few studies have been conducted among Asian children and adolescents with type 1 diabetes mellitus (T1DM) using do-it-yourself artificial pancreas system (DIY-APS). We evaluated real-world data of pediatric T1DM patients using DIY-APS. Data were obtained for 10 patients using a DIY-APS with algorithms. We collected sensor glucose and insulin delivery data from each participant for a period of 4 weeks. Average glycosylated hemoglobin was 6.2%±0.3%. The mean percentage of time that glucose level remained in the target range of 70 to 180 mg/dL was 82.4%±7.8%. Other parameters including time above range, time below range and mean glucose were also within the recommended level, similar to previous commercial and DIY-APS studies. However, despite meeting the target range, unadjusted gaps were still observed between the median basal setting and temporary basal insulin, which should be handled by healthcare providers.

Helicobacter pylori-derived outer membrane vesicles stimulate interleukin 8 secretion through nuclear factor kappa B activation

Background/Aims@#Bacteria-derived outer membrane vesicles (OMVs) are commonly associated with various biological activities and functions. Helicobacter pylori-derived OMVs are thought to contribute to pathogenesis. This study aimed to investigate the effects of H. pylori-derived OMVs. @*Methods@#H. pylori strains were isolated from patients with gastritis, gastric ulcer, or gastric cancer using endoscopic biopsy. The U-937, AGS, and MKN-45 cell lines were exposed to H. pylori and H. pylori-derived OMVs. The expression of interleukin 8 (IL-8) messenger RNA (mRNA) was assessed using reverse transcription-polymerase chain reaction (RT-PCR) and real-time RT-PCR, and IL-8 secretion was analyzed using enzyme-linked immunosorbent assay. Nuclear factor kappa B (NF-κB) activation was evaluated by Western blotting. @*Results@#H. pylori and H. pylori-derived OMVs induced the expression of IL-8 mRNA and protein. Importantly, the bacteria induced higher IL-8 mRNA and protein expression than the OMVs. IL-8 expression was induced to different levels in response to H. pylori-derived OMVs from hosts with different gastric diseases. Western blotting revealed the increased phosphorylation and reduced degradation of inhibitor of NF-κB alpha in cells exposed to OMVs. @*Conclusions@#H. pylori-derived OMVs may aid the development of various gastric diseases by inducing IL-8 production and NF-κB activation.

Reconstruction of Tracheal Defect by Sternocleidomastoid Muscle Flap Covered with Skin Graft: A Case Report / 대한두경부종양학회지

Supracricoid partial laryngectomy (SCPL) with cricohyoidoepiglottopexy (CHEP) or cricohyoidopexy (CHP) involves the removal of the whole thyroid cartilage, both true and false vocal cords, the ventricles, and the paraglottic spaces, sparing the cricoid cartilage, hyoid bone, and at least one functional and mobile cricoarytenoid unit. Reconstruction is performed by suturing of the cricoid cartilage up tightly to the hyoid bone, so trachea-releasing procedures are needed to prevent leakage at anastomosis site. In case of advanced tranglottic cancer invading tracheal tracheal wall, we need to perform additional circumferentrial tracheal wall resection. However, when we perform SCPL, circumferential resection of tracheal wall is limited because SCPL procedure itself needs releasing of tracheal length. We report a case of advanced transglottic cancer involving tracheal wall treated with induction chemotherapy and SCPL including tracheal wall resection with reconstruction of tracheal defect by sternocleidomastoid muscle flap covered with skin graft.

Association of Urinary N-Acetyl-β-D-Glucosaminidase with Cardiovascular Autonomic Neuropathy in Type 1 Diabetes Mellitus without Nephropathy

Background@#Cardiovascular autonomic neuropathy (CAN) is a common microvascular complication of diabetes and related to albuminuria in diabetic nephropathy (DN). Urinary N-acetyl-β-D-glucosaminidase (uNAG) is a renal tubular injury marker which has been reported as an early marker of DN even in patients with normoalbuminuria. This study evaluated whether uNAG is associated with the presence and severity of CAN in patients with type 1 diabetes mellitus (T1DM) without nephropathy. @*Methods@#This cross-sectional study comprised 247 subjects with T1DM without chronic kidney disease and albuminuria who had results for both uNAG and autonomic function tests within 3 months. The presence of CAN was assessed by age-dependent reference values for four autonomic function tests. Total CAN score was assessed as the sum of the partial points of five cardiovascular reflex tests and was used to estimatethe severity of CAN. The correlations between uNAG and heart rate variability (HRV) parameters were analyzed. @*Results@#The association between log-uNAG and presence of CAN was significant in a multivariate logistic regression model (adjusted odds ratio, 2.39; 95% confidence interval [CI], 1.08 to 5.28; P=0.031). Total CAN score was positively associated with loguNAG (β=0.261, P=0.026) in the multivariate linear regression model. Log-uNAG was inversely correlated with frequency-domain and time-domain indices of HRV. @*Conclusion@#This study verified the association of uNAG with presence and severity of CAN and changes in HRV in T1DM patients without nephropathy. The potential role of uNAG should be further assessed for high-risk patients for CAN in T1DM patients without nephropathy.

Mini-Screws-Only Fixation Method for Small Fragments of Medial Malleolus Fractures

Background@#Open reduction and internal fixation is the standard treatment for a displaced medial malleolus fracture (MMFx), achieving ankle stability and bony union to prevent post-traumatic arthritis. Previous fixation techniques including tension band wiring and unicortical screw fixation are not optimal for fixation of small fragments in MMFx due to their small size and poor manipulability. Here, we describe a novel surgical method using mini-screws only for fixation of small fragments in MMFx. @*Methods@#We conducted a retrospective consecutive study of patients who underwent surgery using mini-screws for small fragment MMFx between April 2013 and March 2018. We reviewed the patients’ clinical characteristics and assessed the fracture features radiographically. Clinical outcomes were assessed by measuring the range of motion of both ankle joints and investigating symptomatic implants. We reviewed the radiographic outcomes of the medial malleolus and the functional outcomes using the Foot and Ankle Outcome Score (FAOS) at the last follow-up. @*Results@#Nine patients were included in the study. The minimal follow-up period was 27 months. There was no incidental bone breakage during the procedure. All MMFx healed without reduction loss, nonunion, or implant failure at the last follow-up. Two patients had mild osteoarthritic changes of the ankle joint. The mean FAOS score of the patients was 80.99 (range, 65.44–98.42). No patients required removal of the hardware. @*Conclusions@#Fixation of comminuted fractures of the medial malleolus using mini-screws for young adult patients is a straightforward and simple technique. Safe fixation of the anterior and posterior colliculi reduces the risk of implant irritation symptoms that necessitate implant removal.

Helicobacter pylori-derived outer membrane vesicles stimulate interleukin 8 secretion through nuclear factor kappa B activation

Background/Aims@#Bacteria-derived outer membrane vesicles (OMVs) are commonly associated with various biological activities and functions. Helicobacter pylori-derived OMVs are thought to contribute to pathogenesis. This study aimed to investigate the effects of H. pylori-derived OMVs. @*Methods@#H. pylori strains were isolated from patients with gastritis, gastric ulcer, or gastric cancer using endoscopic biopsy. The U-937, AGS, and MKN-45 cell lines were exposed to H. pylori and H. pylori-derived OMVs. The expression of interleukin 8 (IL-8) messenger RNA (mRNA) was assessed using reverse transcription-polymerase chain reaction (RT-PCR) and real-time RT-PCR, and IL-8 secretion was analyzed using enzyme-linked immunosorbent assay. Nuclear factor kappa B (NF-κB) activation was evaluated by Western blotting. @*Results@#H. pylori and H. pylori-derived OMVs induced the expression of IL-8 mRNA and protein. Importantly, the bacteria induced higher IL-8 mRNA and protein expression than the OMVs. IL-8 expression was induced to different levels in response to H. pylori-derived OMVs from hosts with different gastric diseases. Western blotting revealed the increased phosphorylation and reduced degradation of inhibitor of NF-κB alpha in cells exposed to OMVs. @*Conclusions@#H. pylori-derived OMVs may aid the development of various gastric diseases by inducing IL-8 production and NF-κB activation.

Reconstruction of Tracheal Defect by Sternocleidomastoid Muscle Flap Covered with Skin Graft: A Case Report / 대한두경부종양학회지

Supracricoid partial laryngectomy (SCPL) with cricohyoidoepiglottopexy (CHEP) or cricohyoidopexy (CHP) involves the removal of the whole thyroid cartilage, both true and false vocal cords, the ventricles, and the paraglottic spaces, sparing the cricoid cartilage, hyoid bone, and at least one functional and mobile cricoarytenoid unit. Reconstruction is performed by suturing of the cricoid cartilage up tightly to the hyoid bone, so trachea-releasing procedures are needed to prevent leakage at anastomosis site. In case of advanced tranglottic cancer invading tracheal tracheal wall, we need to perform additional circumferentrial tracheal wall resection. However, when we perform SCPL, circumferential resection of tracheal wall is limited because SCPL procedure itself needs releasing of tracheal length. We report a case of advanced transglottic cancer involving tracheal wall treated with induction chemotherapy and SCPL including tracheal wall resection with reconstruction of tracheal defect by sternocleidomastoid muscle flap covered with skin graft.