Effectiveness of FEES with artificial intelligence-assisted computer-aided diagnosis

OBJECTIVES

FEES is a standard procedure for diagnosing dysphagia. However, appropriate evaluation of FEES findings is difficult for inexperienced evaluators. Recent progress in deep learning has highlighted the use of artificial intelligence-assisted computer-aided diagnosis (AI-assisted CAD) in medical applications. We investigated the detection accuracy of FEES findings evaluated by inexperienced evaluators with and without the use of CAD.

METHODS

The algorithm for FEES-CAD was developed using 25,630 expert-annotated images. A total of 45 inexperienced evaluators from three groups of people (resident doctors, nurses, and medical students), evaluated 32 FEES videos from 32 patients. To confirm the effectiveness of FEES-CAD, first, 32 FEES videos were evaluated without the use of CAD. Second, one half was evaluated with, and one half without, the use of CAD. The detection accuracy of the FEES findings was investigated, and the evaluation results obtained with CAD were statistically compared with those obtained without CAD.

RESULTS

In the first FEES evaluation, the total detection accuracy was 82.2 %. In the second evaluation, the total detection accuracy with CAD was 84.3 %, and that without CAD was 81.7 %. The detection accuracies by the resident doctors, nurses, and medical students with CAD were 90.1 %, 82.6 %, and 79.4 %, respectively, and those without CAD were 83.7 %, 80.9 % and 80.1 %, respectively. In the resident doctors, the detection accuracy was significantly better when CAD was used for evaluation, compared with the non-CAD evaluations.

CONCLUSION

The present study demonstrated the effectiveness of FEES-CAD in improving the detection accuracy of resident doctors, however, the differences were small.

Flowchart for selecting an appropriate surgical airway in neurologically impaired pediatric intubated patients: a case series

OBJECTIVE

Medical advances have resulted in increased survival rates of neurologically impaired children who may require mechanical ventilation and subsequent tracheostomy as a surgical airway. However, at present, there is no definite consensus regarding the timing and methods for placement of a surgical airway in a neurologically impaired intubated child who needs to be cared for over a long-term period. We therefore created a flowchart for the selection of a surgical airway for Neurologically Impaired Pediatric Patients (NIPPs).

METHODS

The flowchart includes information on the patients' backgrounds, such as intubation period, prognosis related to reversibility, and history of aspiration pneumonia. To evaluate the importance of the flowchart, first we conducted a survey of pediatricians regarding selection of a surgical airway, and we also evaluated the appropriateness of the flowchart among pediatricians and caregivers through questionnaire surveys which include satisfaction with the decision-making process, and postoperative course after discharge.

RESULTS

A total of 21 NIPPs with intubation underwent surgery and a total of 24 participants (14 pediatricians and 10 caregivers) completed the survey. The answers regarding the importance of the flowchart showed that eleven pediatricians had experience selecting of surgical airways, nine of whom had had experiences in which they had to make a difficult decision. The answers regarding the appropriateness of the flowchart revealed that all pediatricians and caregivers were satisfied with the decision-making process and postoperative course after discharge using the flowchart.

CONCLUSIONS

The present study demonstrated the effectiveness of our flowchart for selecting an appropriate surgical airway in NIPP. By referring to our flowchart, pediatricians and caregivers are likely to be able to select an appropriate surgical airway, leading to increased satisfaction with the decision-making process and postoperative course.

LEVEL OF EVIDENCE: 4

Will levels of experience of examiners affect the diet provided for patients with swallowing impairment?

OBJECTIVE

Flexible endoscopic evaluation of swallowing (FEES) is widely performed to determine the safety of oral intake. However, evaluation results can vary among examiners depending on their experience. To analyze the impact of such differences, we investigated the diet provided for patients with swallowing impairment evaluated by experienced and inexperienced examiners.

METHODS

We included 20 subjects with swallowing impairment. They underwent FEES twice, once by an experienced examiner (EE) and once by an inexperienced examiner (IE), in random order. The second FEES was generally performed within one month of the first FEES. The diet provided by the EE (EE results) and by the IE (IE results) during and after FEES was investigated and statistically compared. Respiratory and oral intake conditions at each time of FEES were also investigated and the results were included in the corresponding EE or IE results.

RESULTS

The median interval between FEES was 13.5 days. There was no significant difference between the EE and IE results regarding swallowing impairment-related conditions, such as amount of sputum suctioned, oral intake status, or prevalence of fever after FEES. However, there was a significant difference in the texture-modified diet provided after FEES: A close-to-normal diet was provided by the EE compared to the diet provided by the IE.

CONCLUSION

This study demonstrated a difference in the provided diet for patients with swallowing impairment between the examiners with different levels of experience. Our results suggest that EEs may be able to safely recommend patients with swallowing impairment have a close-to-normal diet.

Expert-level aspiration and penetration detection during flexible endoscopic evaluation of swallowing with artificial intelligence-assisted diagnosis

Flexible endoscopic evaluation of swallowing (FEES) is considered the gold standard in diagnosing oropharyngeal dysphagia. Recent advances in deep learning have led to a resurgence of artificial intelligence-assisted computer-aided diagnosis (AI-assisted CAD) for a variety of applications. AI-assisted CAD would be a remarkable benefit in providing medical services to populations with inadequate access to dysphagia experts, especially in aging societies. This paper presents an AI-assisted CAD named FEES-CAD for aspiration and penetration detection on video recording during FEES. FEES-CAD segments the input FEES video and classifies penetration, aspiration, residue in the vallecula, and residue in the hypopharynx based on the segmented FEES video. We collected and annotated FEES videos from 199 patients to train the network and tested the performance of FEES-CAD using FEES videos from other 40 patients. These patients consecutively underwent FEES between December 2016 and August 2019 at Fukushima Medical University Hospital. FEES videos were deidentified, randomized, and rated by FEES-CAD and laryngologists with over 15 years of experience in performing FEES. FEES-CAD achieved an average Dice similarity coefficient of 98.6[Formula: see text]. FEES-CAD achieved expert-level accuracy performance on penetration (92.5[Formula: see text]), aspiration (92.5[Formula: see text]), residue in the vallecula (100[Formula: see text]), and residue in the hypopharynx (87.5[Formula: see text]) classification tasks. To the best of our knowledge, FEES-CAD is the first CNN-based system that achieves expert-level performance in detecting aspiration and penetration.

Cone beam computed tomography with oral contrast for accurate diagnosis and surgical planning of pharyngeal leakage and fistula: a case series

OBJECTIVE

Pharyngocutaneous fistula is one of the severe complications related to head and neck surgeries. Detecting the accurate three-dimensional location of both the fistula and leakage is essential for surgical treatment. Videofluoroscopy is usually used for locating these; however, its imaging is two-dimensional. We evaluated pharyngeal leakage and fistulae using Cone Beam Computed Tomography (CBCT), known for its three-dimensional high spatial resolution imaging, taken in a sitting position, with oral contrast (contrast CBCT).

METHODS

Pharyngeal leakage and fistulae were evaluated in a total of 31 subjects by sequentially performing videofluoroscopy and contrast CBCT. The detection accuracy of videofluoroscopy and contrast CBCT for leakage and fistula, as well as the ability to determine the extent and depth for surgical planning, were investigated and compared.

RESULTS

Videofluoroscopy and contrast CBCT showed suspicious leakage and/or fistula in six and three of the 31 subjects, respectively. Surgical findings revealed the presence of leakage and/or fistula in three of the 31 subjects. The positive predictive values of videofluoroscopy and contrast CBCT were 50% (3/6) and 100% (3/3), respectively. Contrast CBCT provided more precise images, showing the extent and depth of leakage and fistula in three-dimensions.

CONCLUSION

The present study's results indicate the usefulness of contrast CBCT in terms of accurate diagnosis of leakage and fistula, due to its three-dimensional imaging being performed with the patient in a sitting position.

LEVEL OF EVIDENCE: 4

Decannulation after cricotracheostomy: a comparison of partial cricoid cartilage resection with conventional tracheostomy

BACKGROUND

Cricotracheostomy, a modified procedure to open the airway with partial cricoid cartilage resection, was recently reported to be useful in selected cases.

AIMS/OBJECTIVES

To examine decannulation outcomes in patients who underwent cricotracheostomy by comparing it with a conventional tracheostomy.

MATERIALS AND METHODS

Data from 127 consecutive adult patients, who underwent either conventional tracheostomy or cricotracheostomy between 2016 and 2019, were collected and analyzed with respect to subsequent decannulation with stoma closure.

RESULTS

Conventional tracheostomy and cricotracheostomy were performed in 94 and 33 patients, respectively. The most frequent reason for choosing cricotracheostomy was a physiological low-lying larynx (n = 12). After excluding 30 patients who were considered ineligible due to their primary disease, subsequent decannulation with stoma closure was achieved in 35 (46%) of 76 cases with conventional tracheostomy and seven (33%) of 21 cases with cricotracheostomy, showing no significant difference (p = .33).

CONCLUSIONS/SIGNIFICANCE

Compared with a conventional tracheostomy, cricotracheostomy had an acceptable decannulation outcome. However, it should be emphasized that an appropriate selection of patients is required on considering the advantages of cricotracheostomy.

Multicenter Study of Congenital Middle Ear Anomalies. Report on 246 Ears

OBJECTIVES/HYPOTHESIS

Congenital middle ear anomalies represent a relatively rare condition. This study aimed to describe the characteristics and the surgical outcomes for patients with middle ear anomalies.

METHODS

A multicenter study was conducted of consecutive patients with congenital middle ear anomalies who underwent primary surgical treatment between January 2008 and December 2017. Demographics, surgical procedures, and audiometric data were registered into the institutional database. Hearing changes and postoperative air-bone gap (ABG) were evaluated 1 year after surgery.

RESULTS

A total of 246 patients (246 ears) (median age: 14 years, range: 4-75 years old) were included in this study. Anomalies were subdivided using the Teunissen and Cremers classification: 53 ears (22%) were categorized as class I, comprising only stapes ankylosis; 35 ears (14%) as class II, having ossicular chain anomalies with stapes ankylosis; 139 ears (57%) as class III, having ossicular chain anomalies with a mobile stapes-footplate; and 19 ears (8%) as class IV, with aplasia of the oval window. Evaluation of hearing outcomes for 198 ears with more than 1 year of follow-up revealed that good postoperative ABG (≤20 dB) was achieved in 82% of class I, 68% of class II, 74% of class III, and 23% of class IV anomalies. The postoperative ABG in class IV was significantly worse than in class I (P < .001) or class III (P < .01).

CONCLUSIONS

This study demonstrated that class III anomalies comprised the majority of middle ear anomalies and surgical outcomes for class IV anomalies are unfavorable.

LEVEL OF EVIDENCE

4 Laryngoscope, 131:E2323-E2328, 2021.

Using the larynx as a last resort for oral intake in a hypopharyngeal cancer patient

We present a new oral intake route in a hypopharyngeal cancer patient with severe complications. A 64-year-old man was diagnosed as having T2N0M0 squamous cell carcinoma of the posterior wall of the hypopharynx. He had previously undergone radiotherapy for laryngeal cancer and tricuspid valve replacement surgery, and also had atrial flutter and renal dysfunction. We performed surgery with curative intent. The hypopharynx was primarily closed after tumor resection. Laryngotracheal separation and tracheoesophageal diversion with end-to-end anastomosis of the trachea to the esophagus was performed. After surgery, complete oral feeding was achieved using the new pathway created. The larynx, contradictory to its typical role, can be used as a pathway to the esophagus using our revolutionary technique.

Clinical characteristics, the diagnostic criteria and management recommendation of otitis media with antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis (OMAAV) proposed by Japan Otological Society

Anti-neutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV) is a form of necrotizing vasculitis with few or no immune deposits. It primarily affects small and medium blood vessels. AAV is classified into three categories, granulomatosis with polyangiitis (GPA), microscopic polyangiitis (MPA) and eosinophilic granulomatosis with polyangitis (EGPA), and two major ANCAs, proteinase 3 (PR3)-ANCA or myeloperoxidase (MPO)-ANCA are involved in their pathogenesis. Intractable otitis media frequently occurs in patients with GPA, MPA or EGPA, although all patients show similar clinical features, regardless of the type of AAV. Furthermore, approximately 15% patients with otitis media caused by AAV do not show ANCA positivity, histopathological evidence, or any other AAV-related lesions at the initial visit; therefore, these patients do not fulfill the ordinary diagnostic criteria for systemic AAV. Thus, we first proposed that this condition could be categorized as "otitis media with AAV (OMAAV)". Subsequently, the Japanese Otological Society (JOS) conducted a nationwide survey between December 2013 and February 2014 and identified 297 patients with OMAAV. The survey revealed that OMAAV is a disease that initially occurs in the middle ear and subsequently spreads to other organs such as the lungs and kidneys, with eventual involvement of all body organs. Severe sequelae such as facial palsy, hypertrophic pachymeningitis, complete deafness, and subarachnoid hemorrhage resulting in death can also occur. In this review, we introduce the clinical features, diagnostic criteria, and treatment strategies recommended by JOS for early diagnosis and treatment of OMAAV.

Individual response of humans to ionising radiation: governing factors and importance for radiological protection

Tissue reactions and stochastic effects after exposure to ionising radiation are variable between individuals but the factors and mechanisms governing individual responses are not well understood. Individual responses can be measured at different levels of biological organization and using different endpoints following varying doses of radiation, including: cancers, non-cancer diseases and mortality in the whole organism; normal tissue reactions after exposures; and, cellular endpoints such as chromosomal damage and molecular alterations. There is no doubt that many factors influence the responses of people to radiation to different degrees. In addition to the obvious general factors of radiation quality, dose, dose rate and the tissue (sub)volume irradiated, recognized and potential determining factors include age, sex, life style (e.g., smoking, diet, possibly body mass index), environmental factors, genetics and epigenetics, stochastic distribution of cellular events, and systemic comorbidities such as diabetes or viral infections. Genetic factors are commonly thought to be a substantial contributor to individual response to radiation. Apart from a small number of rare monogenic diseases such as ataxia telangiectasia, the inheritance of an abnormally responsive phenotype among a population of healthy individuals does not follow a classical Mendelian inheritance pattern. Rather it is considered to be a multi-factorial, complex trait.

Regenerative potential of basic fibroblast growth factor contained in biodegradable gelatin hydrogel microspheres applied following vocal fold injury: Early effect on tissue repair in a rabbit model

Introduction

Postoperative dysphonia is mostly caused by vocal fold scarring, and careful management of vocal fold surgery has been reported to reduce the risk of scar formation. However, depending on the vocal fold injury, treatment of postoperative dysphonia can be challenging.

Objective

The goal of the current study was to develop a novel prophylactic regenerative approach for the treatment of injured vocal folds after surgery, using biodegradable gelatin hydrogel microspheres as a drug delivery system for basic fibroblast growth factor.

Methods

Videoendoscopic laryngeal surgery was performed to create vocal fold injury in 14 rabbits. Immediately following this procedure, biodegradable gelatin hydrogel microspheres with basic fibroblast growth factor were injected in the vocal fold. Two weeks after injection, larynges were excised for evaluation of vocal fold histology and mucosal movement.

Results

The presence of poor vibratory function was confirmed in the injured vocal folds. Histology and digital image analysis demonstrated that the injured vocal folds injected with gelatin hydrogel microspheres with basic fibroblast growth factor showed less scar formation, compared to the injured vocal folds injected with gelatin hydrogel microspheres only, or those without any injection.

Conclusion

A prophylactic injection of basic fibroblast growth factor -containing biodegradable gelatin hydrogel microspheres demonstrates a regenerative potential for injured vocal folds in a rabbit model.

Thromboxane Generation in Patients with Essential Hypertension or Cerebrovascular Disease and Effect of Oral Aspirin

The ability of platelets to synthesize thromboxane B2 (TxB2) from arachidonic acid (AA) or prostaglandin H2 (PGH2) was studied in 26 control subjects, 40 patients with essential hypertension, 20 patients with cerebrovascular disease (CVD) not taking aspirin and 11 patients with CVD taking aspirin. The activity of platelets to form TxB2 from AA or PGH2 was measured using 1 — 14C arachidonic acid or 1—14C PGH2 as a substrate. There was no significant difference in TxB2 generation from AA or PGH2 among the platelets collected from the control subjects, hypertensive patients and CVD patients not taking aspirin.

In CVD patients taking aspirin, marked suppression was observed in TxB2 synthesis from AA, but no suppression in TxB2 synthesis from PGH2. At least 750 mg aspirin per day were required for nearly complete suppression of TxB2 generation from AA.

Telomere length determined by the fluorescence in situ hybridisation distinguishes malignant and benign cells in cytological specimens

BACKGROUND

Telomeres are tandem repeats of TTAGGG at the end of eukaryotic chromosomes that play a key role in preventing chromosomal instability. The aim of the present study is to determine telomere length using fluorescence in situ hybridisation (FISH) on cytological specimens.

METHODS

Aspiration samples (n = 41) were smeared on glass slides and used for FISH.

RESULTS

Telomere signal intensity was significantly lower in positive cases (cases with malignancy, n = 25) as compared to negative cases (cases without malignancy, n = 16), and the same was observed for centromere intensity. The difference in DAPI intensity was not statistically significant. The ratio of telomere to centromere intensity did not show a significant difference between positive and negative cases. There was no statistical difference in the signal intensities of aspiration samples from ascites or pleural effusion (n = 23) and endoscopic ultrasound-guided FNA samples from the pancreas (n = 18).

CONCLUSIONS

The present study revealed that telomere length can be used as an indicator to distinguish malignant and benign cells in cytological specimens. This novel approach may help improve diagnosis for cancer patients.

Implantation of Induced Pluripotent Stem Cell-Derived Tracheal Epithelial Cells

OBJECTIVES

Compared with using autologous tissue, the use of artificial materials in the regeneration of tracheal defects is minimally invasive. However, this technique requires early epithelialization on the inner side of the artificial trachea. After differentiation from induced pluripotent stem cells (iPSCs), tracheal epithelial tissues may be used to produce artificial tracheas. Herein, we aimed to demonstrate that after differentiation from fluorescent protein-labeled iPSCs, tracheal epithelial tissues survived in nude rats with tracheal defects.

METHODS

Red fluorescent tdTomato protein was electroporated into mouse iPSCs to produce tdTomato-labeled iPSCs. Embryoid bodies derived from these iPSCs were then cultured in differentiation medium supplemented with growth factors, followed by culture on air-liquid interfaces for further differentiation into tracheal epithelium. The cells were implanted with artificial tracheas into nude rats with tracheal defects on day 26 of cultivation. On day 7 after implantation, the tracheas were exposed and examined histologically.

RESULTS

Tracheal epithelial tissue derived from tdTomato-labeled iPSCs survived in the tracheal defects. Moreover, immunochemical analyses showed that differentiated tissues had epithelial structures similar to those of proximal tracheal tissues.

CONCLUSIONS

After differentiation from iPSCs, tracheal epithelial tissues survived in rat bodies, warranting the use of iPSCs for epithelial regeneration in tracheal defects.

Retention of Human-Induced Pluripotent Stem Cells (hiPS) With Injectable HA Hydrogels for Vocal Fold Engineering

Objective:

One prospective treatment option for vocal fold scarring is regeneration with an engineered scaffold containing induced pluripotent stem cells (iPS). In the present study, we investigated the feasibility of utilizing an injectable hyaluronic acid (HA) scaffold encapsulated with human-iPS cell (hiPS) for regeneration of vocal folds.

Methods:

Thirty athymic nude rats underwent unilateral vocal fold injury. Contralateral vocal folds served as uninjured controls. Hyaluronic acid hydrogel scaffold, HA hydrogel scaffold containing hiPS, and HA hydrogel scaffold containing hiPS with epidermal growth factor (EGF) were injected in both vocal folds immediately after surgery. One and 2 weeks after injection, larynges were excised for histology, immunohistochemistry, and fluorescence in situ hybridization (FISH).

Results:

Presence of HA hydrogel was confirmed in vocal folds 1 and 2 weeks post injection. The FISH analysis confirmed the presence and viability of hiPS in the injected vocal folds. Histological results demonstrated that vocal folds injected with HA hydrogel scaffold containing EGF demonstrated less fibrosis than those with HA hydrogel only.

Conclusions:

Human-iPS survived in injured rat vocal folds. The HA hydrogel with hiPS and EGF ameliorated the fibrotic response. Additional work is necessary to optimize hiPS differentiation and further confirm the safety of hiPS for clinical applications.

Effectiveness of steroid injections for bamboo nodules: A case report

Vocal nodules are generally caused by vocal abuse, and conservative treatments such as voice therapy have been advocated as a first-choice treatment for vocal nodules. Reports of vocal fold lesions related to autoimmune diseases, such as bamboo nodules, are rare in the literature. Here we report a very rare case of bamboo nodules in a 30-year-old woman treated by steroid injection into the vocal folds by videoendoscopic laryngeal surgery in an outpatient setting. She was successfully treated without further recurrence. This report indicates that a steroid injection into bamboo nodules might be a useful treatment option, especially in patients who have not shown any improvement after conservative treatments.

Potential of laryngeal muscle regeneration using induced pluripotent stem cell-derived skeletal muscle cells

Conclusion Induced pluripotent stem (iPS) cells may be a new potential cell source for laryngeal muscle regeneration in the treatment of vocal fold atrophy after recurrent laryngeal nerve paralysis. Objectives Unilateral vocal fold paralysis can lead to degeneration, atrophy, and loss of force of the thyroarytenoid muscle. At present, there are some treatments such as thyroplasty, arytenoid adduction, and vocal fold injection. However, such treatments cannot restore reduced mass of the thyroarytenoid muscle. iPS cells have been recognized as supplying a potential resource for cell transplantation. The aim of this study was to assess the effectiveness of the use of iPS cells for the regeneration of laryngeal muscle through the evaluation of both in vitro and in vivo experiments. Methods Skeletal muscle cells were generated from tdTomato-labeled iPS cells using embryoid body formation. Differentiation into skeletal muscle cells was analyzed by gene expression and immunocytochemistry. The tdTomato-labeled iPS cell-derived skeletal muscle cells were transplanted into the left atrophied thyroarytenoid muscle. To evaluate the engraftment of these cells after transplantation, immunohistochemistry was performed. Results The tdTomato-labeled iPS cells were successfully differentiated into skeletal muscle cells through an in vitro experiment. These cells survived in the atrophied thyroarytenoid muscle after transplantation.

Regeneration of tracheal epithelium using mouse induced pluripotent stem cells

Conclusion The findings demonstrated the potential use of induced pluripotent stem cells for regeneration of tracheal epithelium. Objective Autologous tissue implantation techniques using skin or cartilage are often applied in cases of tracheal defects with laryngeal inflammatory lesions and malignant tumor invasion. However, these techniques are invasive with an unstable clinical outcome. The purpose of this study was to investigate regeneration in a tracheal defect site of nude rats after implantation of ciliated epithelium that was differentiated from induced pluripotent stem cells. Method Embryoid bodies were formed from mouse induced pluripotent stem cells. They were cultured with growth factors for 5 days, and then cultured at the air-liquid interface. The degree of differentiation achieved prior to implantation was determined by histological findings and the results of real-time polymerase chain reaction. Embryoid bodies including ciliated epithelium were embedded into collagen gel that served as an artificial scaffold, and then implanted into nude rats, creating an 'air-liquid interface model'. Histological evaluation was performed 7 days after implantation. Results The ciliated epithelial structure survived on the lumen side of regenerated tissue. It was demonstrated histologically that the structure was composed of ciliated epithelial cells.

Chemoselection combined with alternating chemoradiotherapy or surgery for hypopharyngeal cancer

OBJECTIVES/HYPOTHESIS

In order to make possible organ preservation, since 2007 our hospital has performed induction chemotherapy (ICT) with cisplatin and 5-fluorouracil (PF) for hypopharyngeal cancer as chemoselection, followed by alternating chemoradiotherapy (ACRT) with docetaxel, cisplatin, and 5-fluorouracil in (TPF) good responders and curative surgery was used in poor responders.

METHODS

Twenty-six patients with stage III to stage IVB hypopharyngeal cancer received ICT. Eleven of the patients were classified as poor responders and received curative surgery. The remaining 15 patients were classified as good responders. Three of these patients underwent curative surgery, and the remaining 12 underwent ACRT.

RESULTS

The primary lesions in the 12 ACRT patients responded completely to treatment without severe late toxicities. The estimated 3-year laryngectomy-free rate for all 26 patients was 23%. The estimated 3-year overall survival rates for all 26 patients, 12 patients treated with ACRT, and 14 patients who underwent curative surgery, were 79%, 75%, and 84%, respectively.

CONCLUSION

The patients who underwent ACRT showed no significant difference in overall survival compared with the patients who underwent curative surgery. All the patients were able to proceed with this series of therapy, indicating that ICT with PF could be a feasible tool for choosing good responders. Because ACRT with TPF had a high response rate and fewer severe toxicities, this treatment could be safe and have enough impact to control hypopharyngeal cancer in good responders.

LEVEL OF EVIDENCE

4. Laryngoscope, 126:1349-1353, 2016.

Effect of Structural Differences in Collagen Sponge Scaffolds on Tracheal Epithelium Regeneration

OBJECTIVE

We developed an in situ regeneration-inducible artificial trachea composed of a porcine collagen sponge and polypropylene framework and used it for tracheal reconstruction. In the present study, collagen sponges with different structures were prepared from various concentrations of collagen solutions, and their effect on the regeneration of tracheal epithelium was examined.

METHODS

Collagen sponges were prepared from type I and III collagen solutions. The structures of the sponges were analyzed using scanning electron microscopy (SEM). Artificial tracheae, which were formed using the collagen sponges with different structures, were implanted into rabbits, and regeneration of the tracheal epithelium on the artificial tracheae was evaluated by SEM analysis and histological examination.

RESULTS

The SEM analysis showed that collagen sponges prepared from 0.5% and 1.0% collagen solutions had a porous structure. However, the sponges prepared from a 1.5% collagen solution had a nonporous structure. After implantation of artificial tracheae prepared from 0.5% and 1.0% collagen solutions, their luminal surfaces were mostly covered with epithelium within 14 days. However, epithelial reorganization occurred later on artificial tracheae prepared from the 1.5% collagen solution.

CONCLUSION

Collagen sponges with a porous structure are suitable for regeneration of the tracheal epithelium in our artificial trachea.

Visualization of mouse induced pluripotent stem cells for evaluation of tracheal regeneration

CONCLUSION

Visualization of mouse induced pluripotent stem (iPS) cells with the use of a fluorescent protein was successfully achieved for evaluation of tracheal regeneration.

OBJECTIVES

Tracheal epithelial cells derived from iPS cells are expected to be a useful cell source for tracheal regeneration. Our previous study demonstrated that mouse iPS cells differentiated into tracheal epithelial cells. However, when they are implanted into tracheal defects in experimental animals, it is difficult to determine whether the regenerated tracheal epithelium is in fact derived from iPS cells. The purpose of this study was to develop a visualization technique for iPS cells for evaluation of tracheal regeneration.

METHODS

Fluorescent marker tdTomato was transfected into iPS cells. Tracheal epithelial cells were generated from tdTomato-labeled iPS cells using embryoid body formation to detect the expression of tdTomato. The artificial material with tdTomato-labeled iPS cells was implanted into tracheal defects in nude rats. The survival and distribution of tdTomato-labeled iPS cell-derived cells were examined using the IVIS Imaging System and immunostaining.

RESULTS

The expression of tdTomato was detected in both undifferentiated cells and tracheal epithelial cells in vitro. tdTomato-labeled iPS cell-derived cells were successfully detected in the tracheal defects by IVIS Imaging System and immunostaining.

Epithelial cells are active participants in vocal fold wound healing: an in vivo animal model of injury

Vocal fold epithelial cells likely play an important, yet currently poorly defined, role in healing following injury, irritation and inflammation. In the present study, we sought to identify a possible role for growth factors, epidermal growth factor (EGF) and transforming growth factor-beta 1 (TGFβ1), in epithelial regeneration during wound healing as a necessary first step for uncovering potential signaling mechanisms of vocal fold wound repair and remodeling. Using a rat model, we created unilateral vocal fold injuries and examined the timeline for epithelial healing and regeneration during early and late stages of wound healing using immunohistochemistry (IHC). We observed time-dependent secretion of the proliferation marker, ki67, growth factors EGF and TGFβ1, as well as activation of the EGF receptor (EGFR), in regenerating epithelium during the acute phase of injury. Ki67, growth factor, and EGFR expression peaked at day 3 post-injury. Presence of cytoplasmic and intercellular EGF and TGFβ1 staining occurred up to 5 days post-injury, consistent with a role for epithelial cells in synthesizing and secreting these growth factors. To confirm that epithelial cells contributed to the cytokine secretion, we examined epithelial cell growth factor secretion in vitro using polymerase chain reaction (PCR). Cultured pig vocal fold epithelial cells expressed both EGF and TGFβ1. Our in vivo and in vitro findings indicate that epithelial cells are active participants in the wound healing process. The exact mechanisms underlying their roles in autocrine and paracrine signaling guiding wound healing await study in a controlled, in vitro environment.

Multiple drug combination of anti-diabetic agents as a predictor for poor clinical response to liraglutide

AIM

Aim of the study was to retrospectively analyze the clinical parameters that contribute to the therapeutic outcome of GLP-1 analogues.

METHODS

We enrolled 106 patients with type 2 diabetes mellitus (T2DM), treated with liraglutide (N.=69) or exenatide (N.=37) for longer than three months. The patients were divided into two groups: good responders and poor responders to GLP-1 analogues, based on pretreatment and post-treatment HbA1c levels. Good responders were those whose HbA1c level had decreased by 1% or more, or maintained at less than 7%. All other patients were categorized as poor responders. We used univariate and multivariate analyses to assess pretreatment parameters between the two groups.

RESULTS

Approximately 35% of the patients were poor responders. Our analysis of the pretreatment clinical parameters revealed that number of anti-diabetic agents and use of sulfonylurea were significantly associated with poor response to liraglutide (P=0.02 and P=0.03, respectively) in a multivariate analysis. We were not able to find any candidate related to clinical response to exenatide.

CONCLUSION

Our study showed that the therapeutic effects of GLP-1 analogues on T2DM patients were heterogeneous. T2DM patients who require multiple anti-diabetic agents, especially sulfonylurea, do not benefit from liraglutide treatment.

Parotid lymphangioma associated with facial nerve paralysis

Parotid lymphangioma is a relatively rare disease that is usually detected in infancy or early childhood, and which has typical features. Clinical reports of facial nerve paralysis caused by lymphangioma, however, are very rare. Usually, facial nerve paralysis in a child suggests malignancy. Here we report a very rare case of parotid lymphangioma associated with facial nerve paralysis. A 7-year-old boy was admitted to hospital with a rapidly enlarging mass in the left parotid region. Left peripheral-type facial nerve paralysis was also noted. Computed tomography and magnetic resonance imaging also revealed multiple cystic lesions. Open biopsy was undertaken in order to investigate the cause of the facial nerve paralysis. The histopathological findings of the excised tumor were consistent with lymphangioma. Prednisone (40 mg/day) was given in a tapering dose schedule. Facial nerve paralysis was completely cured 1 month after treatment. There has been no recurrent facial nerve paralysis for eight years.

Stiffness of salivary gland and tumor measured by new ultrasonic techniques: Virtual touch quantification and IQ

OBJECTIVE

To evaluate normal salivary gland stiffness and compare the diagnostic performance of virtual touch quantification (VTQ) and virtual touch imaging quantification (VTIQ) for head and neck tumor.

METHODS

A total of 92 measurements were examined, comprising 77 normal salivary glands, 11 benign tumors and four malignant tumors. Examinations were made to evaluate normal salivary gland stiffness and compare the diagnostic performances of new ultrasonic techniques regarding head and neck tumor.

RESULTS

The mean values of VTQ and VTIQ for the normal salivary group (NSG) were 1.92 and 2.06m/s, respectively. The VTQ and VTIQ values were correlative, and there were no statistical differences in each mean value between the normal parotid glands and submandibular glands. For the benign tumor group (BTG), four of the 11 values were non-numeric and were considered above the measurable range. The mean VTIQ value for the BTG was 4.24m/s. For the malignant tumor group (MTG), all four VTQ values were non-numeric. The mean VTIQ value for the MTG was 6.52m/s. For the mean VTIQ values, significant differences were observed among the three groups. The optimum VTQ cutoff value to detect malignant tumors was above the measurable range, and that of VTIQ was 4.83m/s.

CONCLUSION

The VTQ and VTIQ values were correlative for the salivary glands, and the stiffnesses of normal parotid glands were almost same as those of submandibular glands. VTQ and VTIQ values could be applied for the preoperative diagnosis in salivary gland lesions.

Structural and functional vocal fold epithelial integrity following injury

OBJECTIVES/HYPOTHESIS

An intact epithelium is an important part of vocal fold defense. Damage to the epithelium can compromise vocal fold homeostasis and protection of the host tissue from viral and bacterial invasion. Elucidating the effects of damage on epithelial architectural and barrier integrity provides insight into the role of epithelium in protecting vocal folds. Using an animal model, we evaluated the time course of structural and functional epithelial restoration following injury.

STUDY DESIGN

Prospective, controlled animal study.

METHODS

Forty rats underwent surgery to remove vocal fold mucosa unilaterally. Larynges were harvested at five time intervals between 3 to 90 days postinjury and were prepared for histological and permeability analyses.

RESULTS

Rapid restoration of structural integrity was demonstrated by return of a multilayerd epithelium, intercellular junctions, and basement membrane at 5 days postinjury. Atypical epithelial permeability was observed up to 5 weeks postinjury.

CONCLUSION

Restoration of epithelial barrier integrity lags epithelial structural restoration. Consequently, epithelial regeneration cannot be equated with return of functional barrier integrity. Rather, ongoing leakiness of regenerated epithelium indicates that vocal folds remain at risk for damage, pathogen invasion, and remodeling postinjury.

LEVEL OF EVIDENCE

N/A. Laryngoscope, 124:2764-2769, 2014.

Classification for animal vocal fold surgery: resection margins impact histological outcomes of vocal fold injury

OBJECTIVES/HYPOTHESIS

Extent of vocal fold injury impacts the nature and timing of wound healing and voice outcomes. However, depth and extent of the lesion created to study wound healing in animal models vary across studies, likely contributing to different outcomes. Our goal was to create a surgery classification system to enable comparison of postoperative outcomes across animal vocal fold wound-healing studies.

STUDY DESIGN

Prospective, controlled animal study.

METHODS

Rats underwent one of three types of unilateral vocal fold surgeries classified by depth and length of resection. The surgeries were: for subepithelial injury, resection of epithelium and superficial layer of the lamina propria at the midmembranous portion of the vocal fold; for transmucosal injury, resection of epithelium and lamina propria; and for transmuscular injury, resection of epithelium, lamina propria, and superficial portion of the vocalis muscle. Wound healing was evaluated histologically at various time points up to 35 days postinjury.

RESULTS

Complete healing occurred by 14 days postsurgery for subepithelial injury, and by day 35 for transmucosal injury. Injury remained present at day 35 for transmuscular injury.

CONCLUSIONS

Timing and completeness of healing varied by extent and depth of resection. Scarless healing occurred rapidly following subepithelial injury, whereas scarring was observed at 5 weeks after transmuscular injury. The proposed classification system may facilitate comparison of surgical outcomes across vocal fold wound-healing studies.

LEVELS OF EVIDENCE

N/A.

In vitro epithelial differentiation of human induced pluripotent stem cells for vocal fold tissue engineering

OBJECTIVES

We determined the feasibility and optimization of differentiating human induced pluripotent stem cells (hiPS) into nonkeratinized stratified squamous epithelial cells for vocal fold engineering.

METHODS

hiPS were cultured and assessed for differentiation in 3 conditions: a 3-dimensional (3D) hyaluronic acid (HA) hydrogel scaffold, a 3D HA hydrogel scaffold with epidermal growth factor (EGF), and a 3D HA hydrogel scaffold cocultured with human vocal fold fibroblasts (hVFF). After 1, 2, and 4 weeks of cultivation, hiPS were selected for histology, immunohistochemistry, and/or transcript expression analysis.

RESULTS

At 4 weeks, hiPS cultivated with hVFF or with EGF had significantly decreased levels of Oct 3/4, indicating loss of pluripotency. Immunofluorescence revealed the presence of pancytokeratin and of cytokeratin (CK) 13 and 14 epithelial-associated proteins at 4 weeks after cultivation in hiPS EGF and hiPS hVFF cultures. The transcript expression level of CK14 was significantly increased for hiPS hVFF cultures only and was measured concomitantly with cell morphology that was clearly cohesive and displayed a degree of nuclear polarity suggestive of epithelial differentiation.

CONCLUSIONS

We found that hiPS cultivated in 3D HA hydrogel with hVFF demonstrated the most robust conversion evidence to date of epithelial differentiation. Further work is necessary to focus on amplification of these progenitors for application in vocal fold regenerative biology.

Effective embryoid body formation from induced pluripotent stem cells for regeneration of respiratory epithelium

OBJECTIVES/HYPOTHESIS

We have previously demonstrated the potential use of induced pluripotent stem (iPS) cells for regeneration of respiratory epithelium by culturing embryoid bodies (EBs). The aim of the present study was to determine the most effective conditions for EB formation from iPS cells for regeneration of respiratory epithelium.

STUDY DESIGN

Experimental study.

METHODS

iPS cells cultured on a gelatin-coated dish were seeded on low-attachment plates for generating EBs. Under several conditions including the air-liquid interface (ALI) method, with varying cell numbers and suspension times, EBs were transferred to a gelatin-coated dish supplemented with growth factors. The shape, size, aggregation, and adhesion of EBs for iPS cell differentiation were evaluated, and the cultured tissue was histologically examined.

RESULTS

EBs appropriate for differentiation were observed using 1,000 cells after 5 days of suspension culture. Respiratory epithelium-like tissue was histologically observed. The ciliary epithelium was confirmed immunohistologically.

CONCLUSIONS

Based on the varying suspension times and cell numbers with the ALI method, this study presented effective conditions for EB formation from iPS cells for regeneration of respiratory epithelium.

Implantation site-dependent differences for tracheal regeneration with induced pluripotent stem cells (iPS cells)

CONCLUSION

The histological findings and quantitative measurements demonstrated that there were differences in teratoma formation according to the site of implantation. Elucidating the mechanisms of the teratoma formation caused by the site of implantation moves the field another step closer to clinical use of induced pluripotent stem (iPS) cells for tracheal regeneration.

OBJECTIVES

Our previous study demonstrated the potential for iPS cells to be used as a new cell source for tracheal regeneration. However, teratoma formation remains a major problem. Implantation site-dependent differences in teratoma formation have been reported. In this study, the teratoma-forming propensity after implantation into tracheal defects and abdominal subcutaneous tissue was examined histologically and quantitatively.

METHODS

Mouse iPS cells were cultured in artificial material under various conditions. After cultivation in vitro, artificial materials with cultured iPS cells were then implanted into cervical tissue around tracheal defects and into abdominal subcutaneous tissue in nude rats. Teratoma formation was evaluated histologically and quantitatively with measurement of maximum diameter (MD).

RESULTS

Teratoma was observed in 10 of 11 rats with cervical tissue around tracheal defects and in 3 of 11 rats with abdominal subcutaneous tissue implants. The average MD was 5.36 mm in the trachea and 0.97 mm in the abdomen.

Potential for Respiratory Epithelium Regeneration from Induced Pluripotent Stem Cells

Objectives:

In cases of laryngeal inflammatory lesions and tracheal invasion of a malignant tumor, autologous tissue implantation techniques using skin or cartilage are often applied. However, these techniques are both invasive and unstable. The purpose of this study was to evaluate the potential use of induced pluripotent stem (iPS) cells in the regeneration of respiratory epithelium.

Methods:

We seeded iPS cells on low-attachment plates in serum-free media to generate embryoid bodies (EBs). After a 3-day culture, the EBs were transferred to a gelatin-coated dish supplemented with activin A alone or with basic fibroblast growth factor (induction groups). As a control, EBs were cultured without these growth factors (control group). Cultured tissues from all groups were histologically examined for 2 weeks.

Results:

In the induction groups, the presence of respiratory epithelium-like tissue was observed with hematoxylin and eosin staining after 14 days of culture.

Conclusions:

This study demonstrated the potential use of iPS cells in regeneration of the respiratory epithelium.

Evaluation of the use of induced pluripotent stem cells (iPSCs) for the regeneration of tracheal cartilage

The treatment of laryngotracheal stenosis remains a challenge as treatment often requires multistaged procedures, and successful decannulation sometimes fails after a series of operations. Induced pluripotent stem cells (iPSCs) were generated in 2006. These cells are capable of unlimited symmetrical self-renewal, thus providing an unlimited cell source for tissue-engineering applications. We have previously reported tracheal wall regeneration using a three-dimensional (3D) scaffold containing iPSCs. However, the efficiency of differentiation into cartilage was low. In addition, it could not be proven that the cartilage tissues were in fact derived from the implanted iPSCs. The purpose of this study was to evaluate and improve the use of iPSCs for the regeneration of tracheal cartilage. iPSCs were cultured in vitro in a 3D scaffold in chondrocyte differentiation medium. After cultivation, differentiation into chondrocytes was examined. The ratio of undifferentiated cells was analyzed by flow cytometry. The 3D scaffolds were implanted into tracheal defects, as an injury site, in 24 nude rats. Differentiation into chondrocytes in vitro was confirmed histologically, phenotypically, and genetically. Flow cytometric analysis demonstrated that the population of undifferentiated cells was decreased. Cartilage tissue was observed in the regenerated tracheal wall in 6 of 11 rats implanted with induced iPSCs, but in none of 13 rats implanted with the control and noninduced iPSCs. The expression of cartilage-specific protein was also demonstrated in vivo in 3D scaffolds containing iPSCs. The presence of the GFP gene derived from iPSCs was confirmed in samples of cartilage tissue by the combination of laser microdissection (LMD) and polymerase chain reaction (PCR) techniques. Our study demonstrated that iPSCs have the potential to differentiate into chondrogenic cells in vitro. Cartilage tissue was regenerated in vivo. Our results suggest that iPSCs could be a new cell source for the regeneration of tracheal cartilage.

Regeneration of tracheal epithelium using a collagen vitrigel-sponge scaffold containing basic fibroblast growth factor

OBJECTIVES

Our group has had good results in tracheal mucosal regeneration using a collagen vitrigel-sponge scaffold in an animal model. In this study, the effectiveness of this scaffold with the application of basic fibroblast growth factor (b-FGF) was investigated.

METHODS

A collagen vitrigel-sponge scaffold was fabricated with simultaneous addition of b-FGF. Three types of collagen vitrigel-sponge scaffolds were made: no b-FGF, 10 ng of b-FGF, and 100 ng of b-FGF. At 3, 5, 7, and 14 days after implantation in rats, the tracheas were removed and histologically evaluated. The regeneration of mucosal epithelium and the subepithelial layer was evaluated.

RESULTS

Mucosal epithelium, including pseudostratified epithelium and ciliated cells, regenerated earlier in the scaffolds when b-FGF was applied than when b-FGF was not applied. Regeneration of the subepithelial layer, infiltration of inflammatory cells and fibroblasts, and angiogenesis were promoted earlier in the scaffolds with b-FGF application.

CONCLUSIONS

Our technique for tracheal reconstruction using collagen vitrigel-sponge scaffolds with b-FGF application affords a feasible approach for accelerating the regeneration of the intraluminal surface and subepithelial layer of tracheal tissue.

MR imaging-based correction for partial volume effect improves detectability of intractable epileptogenic foci on iodine 123 iomazenil brain SPECT images: an extended study with a larger sample size

BACKGROUND AND PURPOSE

It has been suggested, on the basis of a previous pilot study conducted in a small number of patients, that MR imaging-based PVE correction in I-123 iomazenil brain SPECT improves the detectability of cortical epileptogenic foci. In the present study, we performed an investigation by using a larger sample size to establish the effectiveness of the PVE correction and to conduct a detailed evaluation based on the histologic classification of lesions.

MATERIALS AND METHODS

Seventy-five patients (male/female, 37/38; age, 28 ± 12 years) with intractable epilepsy who had undergone surgical treatment were enrolled in this study. I-123 iomazenil SPECT and MR imaging examinations were performed before the operation in all patients. I-123 iomazenil SPECT images with and without MR imaging-based PVE correction were assessed visually and by semiquantitative analysis based on the AI(%) of the SPECT count in the resected lesions.

RESULTS

The sensitivity, specificity, and accuracy of foci detection by visual assessment were significantly higher after PVE correction compared with the values obtained before the correction. The results of the semiquantitative analysis revealed that the asymmetry of the SPECT counts was significantly increased after the PVE correction in the surgically resected lesions in cases of mesial temporal sclerosis, tumor, and malformations of cortical development.

CONCLUSIONS

The effectiveness of MR imaging-based PVE correction in I-123 iomazenil brain SPECT in improving the detection of cortical epileptogenic foci with abnormal histologic findings was established by our investigation conducted on a large sample size.

Surgical Treatment of Laryngeal Papillomatosis Using Narrow Band Imaging

Laryngeal papillomatosis has a high rate of recurrence after surgery. Narrow band imaging (NBI) is a novel optical enhancement technology used for the diagnosis. This is the first report to date to indicate the availability of the combination of laryngomicro surgery and videoendoscopic surgery for laryngeal papillomatosis using NBI technology. The patients were a 34-year-old man and a 30-year-old man. Both patients underwent surgery in another hospital. However, due to recurrence, they were subsequently referred to the authors’ department for further evaluation. The presence of papillomas was confirmed by NBI, and the papillomas were removed using an XPS Micro Debrider and a CO2 laser. Using the NBI system, the border between the normal mucosa and the papillomas could be clearly identified, allowing precise resection. Further treatment on the lesions has been carried out several times to date using NBI. The lesions have now been eradicated without further recurrence.

Lipid infiltration in the parotid glands: a clinical manifestation of metabolic syndrome

BACKGROUND

The clinical features of lipid infiltration in the parotid glands (LIPG) have not been studied. Monitoring of atomic-bomb survivors for late effects of radiation exposure has provided the opportunity to review the clinical findings of LIPG.

METHODS

A total of 992 atomic-bomb survivors in Nagasaki, Japan underwent lachrymal and salivary secretion tests and anthropometric, biochemical, and abdominal ultrasonographic examinations between 2002 and 2004. Among 465 subjects who had reduced tear and/or salivary excretion, 176 subjects took a salivary magnetic resonance imaging (MRI) examination.

RESULTS

LIPG was detected in 53 of the 176 subjects who had salivary MRI. LIPG cases showed a preponderance of females and fatty liver compared with the subjects without LIPG. Age-and-sex-adjusted regression analysis revealed that body mass index (BMI), low-density lipoprotein cholesterol, triglycerides, hemoglobin A1c, and C-reactive protein were higher, whereas high-density lipoprotein cholesterol and adiponectin were lower, in the subjects with LIPG. Multivariate logistic regression analysis showed that BMI and fatty liver were mutually associated with LIPG independently from radiation dose.

CONCLUSIONS

LIPG associated with BMI, fatty liver, and coronary risk factors was a clinical manifestation of metabolic syndrome.

Surgical Treatment of Laryngeal Papillomatosis Using NBI

Objective: Multiple laryngeal papillomatosis has a high rate of recurrence after surgery. Narrowband imaging (NBI) is a novel optical enhancement technology used for the diagnosis. This is the first report to date to indicate the availability of the combination of laryngomicro surgery and videoendoscopic surgery for laryngeal papillomatosis using NBI technology.

Method: The patients were 34-year-old and 30-year-old men. Both cases underwent surgery in another hospital. However, because of recurrence, they were subsequently referred to our department for further evaluation. Examination in our outpatient clinic revealed papilloma-like mucosal changes, and recurrent multiple laryngeal papillomatosis was diagnosed in both cases.

Results: In laryngomicroscopic surgical findings, the presence of papillomas was confirmed by NBI, and the papillomas were removed using an XPS Micro Debrider and a CO2 laser. Using the NBI system, the border between the normal mucosa and the papillomas could be clearly identified, allowing precise resection. Two months later, CO2 laser resection using a laryngeal flexible endoscope under topical anesthesia was undertaken in an outpatient setting for recurring or remaining papilloma lesions. Further treatment on the lesions has been carried out several times to date using NBI. The lesions have now been eradicated without further recurrence.

Conclusion: Herein we reported 2 cases of multiple laryngeal papillomatosis that were treated by tumor resection using NBI. Clearer identification of the tumor border was obtained by this technique, thus allowing minimally invasive resection. This paper demonstrates the applicability of the NBI system to the identification and resection of laryngeal papillomatosis.

[Outcome of treatment for chest trauma at a single institution]

Between March 2005 and September 2009, 41,827 patients visited our emergency outpatient clinic, and 50 patients (0.12%) were admitted to our institution for chest trauma. Seventy percent of the chest traumas were caused by traffic accidents. Eighty-five percent of the traffic accidents were associated with car driving or motorcycle driving. Rib fracture, pneumothorax, hemothorax, and lung injury were seen in 56%, 40%, 22%, and 28% of the patients, respectively. Chest tube drainage was performed in 36% of the patients. Sixty-two percent of the patients with chest trauma underwent conservative follow-up. Only 1 patient underwent the ligation of the intercostal artery. One patient with chest trauma and fracture of the cervical vertebra and the pelvis died, who was in the state of cardio-pulmonary arrest on arrival. Forty-nine patients were discharged in 15.2 +/- 17.0 days. Twenty-two percent of the patients were hospitalized only 1 night.

Potential of induced pluripotent stem cells for the regeneration of the tracheal wall

OBJECTIVES

Our previous studies focused on basic research and the clinical applications of an artificial trachea. However, the prefabricated artificial trachea cannot be utilized for pediatric airways, because the tracheal frame needs to expand as the child develops. The purpose of this study was to evaluate the potential of induced pluripotent stem (iPS) cells for the regeneration of the tracheal wall.

METHODS

We cultured iPS cells in a 3-dimensional (3-D) scaffold in chondrocyte differentiation medium (bioengineered scaffold model), and the results were compared with those in a 3-D scaffold without iPS cells (control scaffold model). The 3-D scaffolds were implanted into tracheal defects in 8 nude rats. After 4 weeks, the regenerated tissue was histologically examined.

RESULTS

Implanted iPS cells were confirmed to exist in all 5 rats implanted with bioengineered scaffolds. Cartilage-like tissue was observed in the regenerated tracheal wall in 2 of the 5 rats in the bioengineered scaffold model, but in none of the 3 rats in the control scaffold model.

CONCLUSIONS

Implanted iPS cells were confirmed to exist in the bioengineered scaffold. Cartilage-like tissue was regenerated in the tracheal defect. This study demonstrated the potential of iPS cells in the regeneration of the tracheal wall.

[Reconstruction of the left common carotid artery for dissective occlusion detected by intra-operative ultrasonography]

We describe a case of Stanford type A acute aortic dissection. Replacement of the ascending aorta and aortic arch was performed using an "arch 1st technique". Following the completion of replacement, hypotension of the left superficial temporal artery pressure was detected. Ultrasonography revealed dissection of the left common carotid artery (LCCA) and compressive occlusion of the true lumen. Reconstruction of the LCCA was performed in the neck. The patient did well after the operation without any neurological abnormalities.