CHCHD2 P14L, found in amyotrophic lateral sclerosis, exhibits cytoplasmic mislocalization and alters Ca2+ homeostasis.

CHCHD2 and CHCHD10, linked to Parkinson's disease and amyotrophic lateral sclerosis-frontotemporal dementia (ALS), respectively, are mitochondrial intermembrane proteins that form a heterodimer. This study aimed to investigate the impact of the CHCHD2 P14L variant, implicated in ALS, on mitochondrial function and its subsequent effects on cellular homeostasis. The missense variant of CHCHD2, P14L, found in a cohort of patients with ALS, mislocalized CHCHD2 to the cytoplasm, leaving CHCHD10 in the mitochondria. Drosophila lacking the CHCHD2 ortholog exhibited mitochondrial degeneration. In contrast, human CHCHD2 P14L, but not wild-type human CHCHD2, failed to suppress this degeneration, suggesting that P14L is a pathogenic variant. The mitochondrial Ca2+ buffering capacity was reduced in Drosophila neurons expressing human CHCHD2 P14L. The altered Ca2+-buffering phenotype was also observed in cultured human neuroblastoma SH-SY5Y cells expressing CHCHD2 P14L. In these cells, transient elevation of cytoplasmic Ca2+ facilitated the activation of calpain and caspase-3, accompanied by the processing and insolubilization of TDP-43. These observations suggest that CHCHD2 P14L causes abnormal Ca2+ dynamics and TDP-43 aggregation, reflecting the pathophysiology of ALS.

Regeneration of the ureter using a scaffold-free live-cell structure created with the bio-three-dimensional printing technique.

Ureteral strictures, which can be caused by ureteral injury, radiation therapy, ureterolithiasis, urinary tract infections, and ureteral endometriosis, typically require ureteral reconstruction. Although tissue engineering, autologous alternative tissue transplantation, and surgical techniques applying various flaps have been carried out for ureteral regeneration, all with some success, each method has its advantages and disadvantages. As an alternative, we created the first artificial ureter structures using only live cells and grafted them into healthy rat ureters. Spheroids were created using normal human dermal fibroblasts and human umbilical vein endothelial cells and subsequently laminated using a bio-three-dimensional printer. After molding the laminated spheroids into tubular structures, the artificial ureters were transplanted into live rats. After 2-12 weeks, the animals were sacrificed and their gross and pathological features were examined. In the artificial ureteral lumen of rats with Grade 0-1 hydronephrosis, regeneration of the ureteral epithelium was observed, the thickness of which increased over the course of the experiment. Regeneration of the muscular layer was also observed, extending from the normal ureteral side toward the artificial ureter structure over time. However, complete regeneration was not observed at the end of 12 weeks. Although ureteral peristalsis was noted in all cases, it was weaker than expected. Therefore, we achieved short-segment ureteral regeneration using a cell-only structure. This finding suggests that by applying alternative strategies to this method, such as changing the cell type and composition, regeneration over the entire length of the ureter may be possible in the future. STATEMENT OF SIGNIFICANCE: Until now, ureteral regeneration techniques have been dominated by the use of high-molecular-weight compounds and autologous tissues, and there have been no reports of regeneration using structures made entirely of cells. This is the first report of ureteral regeneration using a tubular structure made from stacked spheroids. Although this study only attained short-segment ureteral regeneration, regeneration of the ureter over a much longer proportion of its length can be achieved in the future by applying other strategies, such as changing the cell type. This study provides a foundation to achieve the future goal of complete regeneration.

Synchronous gallbladder metastasis originating from residual gastric cancer: a case report and the review of literature.

BACKGROUND: Gastric cancer rarely metastasizes to the gallbladder. Furthermore, there has never been a case report of simultaneous gallbladder metastasis from residual gastric cancer. Here, we report a case of synchronous gallbladder metastasis originating from a residual gastric cancer. CASE PRESENTATION: A 67-year-old man underwent a follow-up upper endoscopy 18 months after a partial gastrectomy for gastric cancer; an ulcerative lesion was found in the remnant stomach at the gastrojejunal anastomosis. A biopsy revealed gastric signet-ring cell carcinoma (SRCC). A full-body examination revealed no abnormalities other than gallstones in the gallbladder. With a diagnosis of residual gastric cancer (cT2N0M0 cStage I), the patient underwent open total gastrectomy and cholecystectomy. Macroscopic findings of the resected specimen revealed thickening of the gallbladder wall; however, no obvious neoplastic lesions were found on the mucosal surface of the gallbladder. The pathological findings showed that the SRCC had invaded the submucosa of the gastrojejunostomy site with a high degree of lymphatic invasion and lymph node metastases. SRCCs were also found in the lymphatic vessels of the gallbladder wall. These findings suggested the possibility of gallbladder metastasis through lymphatic vessels. The patient and his family members refused postoperative chemotherapy. Ten months after the operation, the patient experienced respiratory failure due to lymphangitis carcinomatosa and died. CONCLUSIONS: At present, it is difficult to determine whether resection of the gallbladder contributes to an improved prognosis of gastric cancer patients. However, reports in such cases demonstrate that gallbladder metastasis could be a poor predictor of prognosis for gastric cancer.

Cell Inertia: Predicting Cell Distributions in Lung Vasculature to Optimize Re-endothelialization.

We created a transient computational fluid dynamics model featuring a particle deposition probability function that incorporates inertia to quantify the transport and deposition of cells in mouse lung vasculature for the re-endothelialization of the acellular organ. Our novel inertial algorithm demonstrated a 73% reduction in cell seeding efficiency error compared to two established particle deposition algorithms when validated with experiments based on common clinical practices. We enhanced the uniformity of cell distributions in the lung vasculature by increasing the injection flow rate from 3.81 ml/min to 9.40 ml/min. As a result, the cell seeding efficiency increased in both the numerical and experimental results by 42 and 66%, respectively.

Successful use of bio plugs for delayed bronchial closure after pneumonectomy in experimental settings.

OBJECTIVES: Cell therapies, such as stem cell suspension injection, are used to treat bronchopleural fistula. Although it is safe and effective, injected cells cannot remain within the bronchioles of the fistula due to cell leakage into the thoracic cavity. Here, we inserted a 'bio plug' into the fistula, produced using cells and a bio-3D printer, to examine the effectiveness of bio plugs for the closure of bronchopleural fistulas, the optimal cell source and the closure mechanism. METHODS: Bio plugs were made with mesenchymal stem (stromal) cells derived from bone marrow (MSCBM), fibroblasts and rat lung micro-vessel endothelial cells using a bio-3D printer with different cell mixing ratios. Six groups, according to the presence or absence and the type of bio plugs, were compared. The plugs were inserted into the bronchi of F344 rats. The obstruction ratio and histological and immunohistochemical findings were evaluated. RESULTS: MSCBM+ rat lung micro-vessel endothelial cell group exhibited a higher obstruction ratio among all groups excluding the MSCBM group (P = 0.039). This group had fibrosis and CD31-positive cells and fewer CD68-positive cells than MSCBM and MSCBM+ fibroblast groups. CONCLUSIONS: Bio plugs with mixed cells, including stem cells, contribute to bronchial closure in the current experimental setting. Endothelial cells effectively maintain the structure in this model. Although bronchial closure for bronchopleural fistula could not be described as clinical conditions were not reproduced, we collected essential data on bronchial closure; however, further experiments are warranted.

Use of High-Rate Ventilation Results in Enhanced Recellularization of Bioengineered Lung Scaffolds.

While transplantation is a viable treatment option for end-stage lung diseases, this option is highly constrained by the availability of organs and postoperative complications. A potential solution is the use of bioengineered lungs generated from repopulated acellular scaffolds. Effective recellularization, however, remains a challenge. In this proof-of-concept study, mice lung scaffolds were decellurized and recellurized using human bronchial epithelial cells (BEAS2B). We present a novel liquid ventilation protocol enabling control over tidal volume and high rates of ventilation. The use of a physiological tidal volume (300 µL) for mice and a higher ventilation rate (40 breaths per minute vs. 1 breath per minute) resulted in higher cell numbers and enhanced cell surface coverage in mouse lung scaffolds as determined via histological evaluation, genomic polymerase chain reaction (PCR) analysis, and immunohistochemistry. A biomimetic lung bioreactor system was designed to include the new ventilation protocol and allow for simultaneous vascular perfusion. We compared the lungs cultured in our dual system to lungs cultured with a bioreactor allowing vascular perfusion only and showed that our system significantly enhances cell numbers and surface coverage. In summary, our results demonstrate the importance of the physical environment and forces for lung recellularization. Impact statement New bioreactor systems are required to further enhance the regeneration process of bioengineered lungs. This proof-of-concept study describes a novel ventilation protocol that allows for control over ventilation parameters such as rate and tidal volume. Our data show that a higher rate of ventilation is correlated with higher cell numbers and increased surface coverage. We designed a new biomimetic bioreactor system that allows for ventilation and simultaneous perfusion. Compared to a traditional perfusion only system, recellularization was enhanced in lungs recellularized with our new biomimetic bioreactor.

Recurrent intraductal papillary neoplasm of the bile duct due to intraductal dissemination: a case report and literature review.

BACKGROUND: Intraductal papillary neoplasm of the bile duct (IPNB) is a subtype of biliary tumor. The 5-year survival rate of patients with IPNB who underwent curative resection is 81%. However, IPNB is known to often recur in other parts of the bile duct. Nevertheless, its mechanism remains poorly understood. Herein, we report the case of a patient with recurrent IPNB, which was considered to be attributed to intraductal dissemination in the common bile duct at 12 months after curative resection. We also made a review of the existing literature. CASE PRESENTATION: A 69-year-old man was referred to our hospital for the evaluation and dilation of an intrahepatic bile duct (IHBD) mass. Computed tomography (CT) findings confirmed a mass in the left hepatic duct. Left trisectionectomy, extrahepatic bile duct resection with biliary reconstruction, and regional lymph node dissection were performed. Intraoperative examination of the resection margin at the common bile duct and posterior segmental branch of the hepatic duct was negative for the presence of malignant cells. Histologically, the tumor showed intraductal papillary growth of the mucinous epithelium and was diagnosed as non-invasive IPNB. It had a papillary structure with atypical epithelial cells lined up along the neoplastic fibrovascular stalks. Immunohistochemically, this was as a gastric-type lesion. At 12 postoperative months, CT revealed a 1.5-cm mass in the lower remnant common bile duct. We performed subtotal stomach-preserving pancreaticoduodenectomy. The tumor exhibited papillary growth and was microscopically and immunohistochemically similar to the first tumor. At approximately 16 months after the patient's second discharge, CT showed an abdominal mass at the superior mesenteric plexus, which was diagnosed as recurrent IPNB. Chemotherapy is ongoing, and the patient is still alive. In this case, as described in many previous reports, IPNB recurred below the primary lesion in the bile duct. CONCLUSION: Based on our review of previous reports on IPNB recurrence, intraductal dissemination was considered one of the mechanisms underlying recurrence after multicentric development. Considering the high frequency and oncological conversion of recurrence in IPNB, regular follow-up examination is essential to achieve better prognosis in patients with recurrent IPNB.

Pancreatic enzymatic mediastinitis followed by total gastrectomy with splenectomy: report of two cases.

BACKGROUND: Acute mediastinitis is a rare disease that rapidly progresses with a high mortality rate. Its most common cause is direct injury of the mediastinum, including iatrogenic causes such as cardiac surgery or upper endoscopy. Enzymatic mediastinitis is a rare complication of a pancreatic fistula caused by the inflammatory digestion of the parietal peritoneum spreading to the mediastinum. Here, we present two cases of enzymatic mediastinitis caused by total gastrectomy with splenectomy. One of them was successfully treated and cured after early diagnosis and transabdominal drainage. CASE PRESENTATION: Case 1 was that of a 60-year-old man (body mass index [BMI] 27) with a medical history of diabetes and hypertension who was diagnosed with advanced gastric cancer in the upper body of the stomach. A total gastrectomy with splenectomy was performed. The patient experienced acute respiratory failure 24 h after surgery. Pulmonary embolism was suspected, so a computed tomography (CT) scan was performed; however, no relevant causes were found. Although he was immediately intubated and treated with catecholamine, he died in the intensive care unit (ICU) 40 h after surgery. Post-mortem findings revealed retroperitonitis caused by a pancreatic fistula spreading towards the mediastinum, causing severe mediastinitis; a review of the CT scan revealed pneumomediastinum. We concluded that the cause of death was enzymatic mediastinitis due to post-gastrectomy pancreatic fistula. Case 2 involved a 61-year-old man (BMI 25) with a medical history of appendicitis who was diagnosed with advanced gastric cancer at the gastric angle between the lesser curvature and the pylorus, spreading to the upper body of the stomach. A total gastrectomy with splenectomy was also performed. The patient had a high fever 3 days after the surgery, and a CT scan revealed pneumomediastinum, indicating mediastinitis. As the inflammation was below the bronchial bifurcation, we chose a transabdominal approach for drainage. The patient was successfully treated and discharged. CONCLUSION: Acute mediastinitis caused by gastrectomy is rare. The acknowledgment of abdominal surgery as a cause of mediastinitis is important. In treating mediastinitis caused by abdominal surgery, transabdominal drainage may be a minimally invasive yet effective method if the inflammation is mainly located below the bifurcation of the trachea.

Safety, efficacy, and analysis of key parameters after prophylactic administration of a sustained-release formulation of azithromycin in lung cancer surgery.

BACKGROUND: The current use of prophylactic antibiotics for lung cancer surgery requires modification in aging individuals with impaired lung function. A sustained-release formulation of azithromycin (AZM-SR) could help resolve some of these challenges with its sustained antibacterial and anti-inflammatory effects. The aim of this study was to examine the safety and efficacy of AZM-SR in lung cancer surgery as well as its anti-inflammatory effect. METHODS: Fifty patients were included in the study, and AZM-SR was administered 1 day prior to the surgery. The clinical course, including postoperative complications, was monitored, and the concentration of AZM, bacterial culture, and inflammatory cytokine levels of resected lung specimens were evaluated. RESULTS: No side effects related to AZM-SR were observed. Five cases of postoperative pneumonia (10%) were observed; technical issues were involved in 3 cases. All patients recovered well. Four cases showed positive bacterial culture upon lung tissue examination; however, this was not significantly correlated with postoperative complications. A negative correlation was observed between AZM concentration in lung tissue and interleukin-6 (IL-6) expression. CONCLUSIONS: Prophylactic utilization of AZM-SR in lung cancer surgery seems feasible. The anti-inflammatory effect of AZM might contribute additional beneficial effects in the perioperative management of lung cancer surgery.

Radiation-Induced Myopathy Developing in a Hodgkin Lymphoma Patient: An Autopsy Case with Systemic Muscle Sampling.

Radiation-induced myopathy (RIM) is a rare complication occurring years after radiotherapy. RIM basically occurs within the irradiation field, but some cases have been reported to be accommodated by myopathy outside the irradiation field, and the actual extent of RIM is obscure. The presented case also showed decreased MMT scores and abnormal needle electromyography results in the muscles outside the irradiated field, and the patient was initially thought to have RIM both within and outside the irradiated field. However, while systemic postmortem muscle sampling revealed prominent myopathy in line with RIM in the irradiated muscles, only mild myogenic changes that could be explained by other causes such as age-related sarcopenia, radiculopathy, and disuse atrophy were observed in the non-irradiated muscles. The number of biopsy sites in live patients is limited due to the invasive nature of the procedure, but we were privileged to systemically evaluate the extent of myopathy through multiple muscle sampling including muscles both inside and outside of the irradiation field because this was an autopsy case. Through the presented case, we conclude that RIM is a phenomenon most probably limited to the muscles within the irradiated field, and myopathy outside the irradiation is due to other causes.

Lethal multiple colon necrosis and perforation due to fulminant amoebic colitis: a surgical case report and literature review.

BACKGROUND: Amoebiasis caused by the protozoan species Entamoeba histolytica rarely develops into fulminant amoebic colitis (FAC), but when it does, it shows an aggressive clinical course including colonic perforation, necrotizing colitis, and high mortality. Surgical treatment for FAC patients should be carried out urgently. However, even after surgery, the mortality rate can be 40-50%. Although FAC is one of the most unfavorable surgical diseases with a poor prognosis, there are a few reports on the perioperative diagnosis and management of FAC based on autopsy findings. We herein report the surgical case of a 64-year-old man who developed multiple colon necrosis and perforation due to FAC. A detailed autopsy revealed FAC as the cause of death. Additionally, we reviewed the existing literature on FAC patients who underwent surgery and followed their perioperative diagnosis and management. CASE PRESENTATION: A 64-year-old man presented with anorexia, diarrhea, and altered consciousness on arrival to our hospital. Computed tomography revealed a large mass in the upper right lobe of his lung, and the patient was admitted for close investigation. Bloody diarrhea, lower abdominal pain, and hypotension were observed soon after admission. Urgent abdominal contrast-enhanced computed tomography scan revealed extensive intestinal ischemia, intestinal pneumatosis, and free intra-abdominal gas. The preoperative diagnosis was bowel necrosis and perforation with intussusception of the small intestinal tumor. Emergency subtotal colectomy and enterectomy were performed soon after the contrast-enhanced computed tomography. He was taken to an intensive care unit after surgery. However, he could not recover from sepsis and died with disseminated intravascular coagulation and multiple organ failure on the 10th-day post-surgery. A histopathological examination of the resected colon showed transmural necrosis and massive amoebae invasion. He was diagnosed with FAC. An autopsy revealed that he had developed pulmonary large cell carcinoma with small intestinal metastasis. The death was caused by intestinal ischemia, necrosis and the perforation of the residual bowel caused by amoebae invasion. CONCLUSIONS: Since FAC is a lethal disease with a high mortality rate and antibiotic therapies except metronidazole are ineffective, preoperative serological testing and perioperative metronidazole therapy in FAC patients can dramatically improve their survival rates.

Negative Pressure Cell Delivery Augments Recellularization of Decellularized Lungs.

For end-stage lung disease, lung transplantation remains the only treatment but is limited by the availability of organs. Production of bioengineered lungs via recellularization is an alternative but is hindered by inadequate repopulation. We present a cell delivery method via the generation of negative pressure. Decellularized lungs were seeded with human bronchial epithelial cells using gravity-based perfusion or negative pressure (via air removal). After delivery, lungs were maintained in static conditions for 18 h, and cell surface coverage was qualitatively assessed using histology and analyzed by subjective scoring and an image analysis software. Negative pressure seeded lungs had higher cell surface coverage area, and this effect was maintained following 5 days of culture. Enhanced coverage via negative pressure cell delivery was also observed when vasculature seeded with endothelial cells. Our findings show that negative pressure cell delivery is a superior approach for the recellularization of the bioengineered lung. Impact statement New strategies are required to overcome the shortage of organ donors for lung transplantation. Recellularization of acellular biological scaffolds is an exciting potential alternative. Adequate recellularization, however, remains a significant challenge. This proof of concept study describes a novel cell delivery approach, which further enhances the recellularization of decellularized lungs. Organs seeded and cultured with this method possess higher cell surface coverage and number compared to those seeded via traditional gravity-based perfusion approaches.

Preoperative tracheal resection and reconstruction simulations with patient-specific three-dimensional models.

Three-dimensional (3D) printers are increasingly being used for a variety of applications. In the surgical field, patient-specific organ models are increasingly being used as preoperative simulators for complicated surgeries. In this study, we describe the use of patient-specific 3D models for tracheal resection. We performed preoperative simulations for two patients diagnosed with tracheal ganglioneuroma and adenoid cystic carcinoma; the mimic operations suggested the necessity of a short cuff intubation tube across the surgical field, indicating the recommended amount of dissection around the trachea and bilateral hilum prior to tracheal reconstruction. The postoperative courses were free from any anastomotic or pulmonary complications. We described the availability of preoperative simulations for complicated tracheal resection and reconstruction using patient-specific 3D printed models. Mimic operations using the 3D printed models allowed accurate preparation and confidence in selection of the optimal surgical strategy.

A new method using a vessel-sealing system provides coagulation effects to various types of bleeding with less thermal damage.

BACKGROUND: Hemostasis is very important for a safe surgery, particularly in endoscopic surgery. Accordingly, in the last decade, vessel-sealing systems became popular as hemostatic devices. However, their use is limited due to thermal damage to organs, such as intestines and nerves. We developed a new method for safe coagulation using a vessel-sealing system, termed flat coagulation (FC). This study aimed to evaluate the efficacy of this new FC method compared to conventional coagulation methods. METHODS: We evaluated the thermal damage caused by various energy devices, such as the vessel-sealing system (FC method using LigaSure™), ultrasonic scissors (Sonicision™), and monopolar electrosurgery (cut/coagulation/spray/soft coagulation (SC) mode), on porcine organs, including the small intestine and liver. Furthermore, we compared the hemostasis time between the FC method and conventional methods in the superficial bleeding model using porcine mesentery. RESULTS: FC caused less thermal damage than monopolar electrosurgery's SC mode in the porcine liver and small intestine (liver: mean depth of thermal damage, 1.91 ± 0.35 vs 3.37 ± 0.28 mm; p = 0.0015). In the superficial bleeding model, the hemostasis time of FC was significantly shorter than that of electrosurgery's SC mode (mean, 19.54 ± 22.51 s vs 44.99 ± 21.18 s; p = 0.0046). CONCLUSION: This study showed that the FC method caused less thermal damage to porcine small intestine and liver than conventional methods. This FC method could provide easier and faster coagulation of superficial bleeds compared to that achieved by electrosurgery's SC mode. Therefore, this study motivates for the use of this new method to achieve hemostasis with various types of bleeds involving internal organs during endoscopic surgeries.

Enhanced airway stenting using a preoperative, three-dimensionally printed airway model simulation.

Three-dimensionally printed organ models that facilitate preoperative simulations have the potential to improve outcomes of surgical procedures. Here, we report a case involving a 54-year-old man diagnosed with lung cancer of the right upper bronchus that was invading the right main bronchus. A right upper lobectomy with carinoplasty was performed. Although complete excision of the tumor was achieved, exertional dyspnea redeveloped 4 months post-surgery. Chest computed tomography revealed that airway stenosis caused by granulation had deformed the airway. Ablation of the granulation and airway stenting was required to improve the patient's symptoms. Prior to performing airway stenting, a three-dimensionally printed airway model was constructed, and the Y-shaped silicone stent used was modified in accordance with the model. After stenting, both the right and left bronchi were preserved, and the patient's symptoms improved. The three-dimensional printed airway model enhanced the accuracy and safety of the airway stenting procedure performed.

Pure pancreatic hepatoid carcinoma: a surgical case report and literature review.

BACKGROUND: Hepatoid carcinoma (HC) is an extra-hepatic neoplasm that shares the morphological and immunohistochemical features of hepatocellular carcinoma. Pancreatic HC exists as either pure or combined type. Pure pancreatic HC is extremely rare, with only a few cases reported in the literature to date. Because of the rarity of pure pancreatic HC, its clinical features including incidence, behavior, and prognosis remain unclear. We herein report the case of a 56-year-old man who developed pure pancreatic HC treated with surgical resection. We also include a review of the existing literature. CASE PRESENTATION: A 56-year-old male patient was admitted to our hospital after a pancreatic cyst was identified by abdominal ultrasonography on a comprehensive medical examination. Endoscopic ultrasound revealed a cystic mass measuring 13 mm in size in the pancreatic head and a low-density mass measuring 16 mm in size in the pancreatic tail, which was partially enhanced on contrast-enhanced ultrasound. Contrast-enhanced computed tomography (CT) revealed a branch duct type intraductal papillary mucinous neoplasm in the pancreatic head and an early enhanced nodule measuring approximately 10 mm in size in the pancreatic tail. Endoscopic ultrasound-guided fine-needle aspiration of the hypervascular tumor was performed. The hypervascular tumor was suspected to be a solid pseudopapillary neoplasm. Laparoscopic spleen-preserving distal pancreatectomy was performed. Histology was identical to hepatocellular carcinoma of the liver. Immunohistochemically, the tumor cells were positive for hepatocyte paraffin 1, and a canalicular pattern was confirmed on the polyclonal carcinoembryonic antigen staining. The patient was diagnosed with a moderately differentiated pancreatic HC. The patient was followed up without adjuvant chemotherapy, and there was no evidence of recurrence at 6 months post-operatively. CONCLUSIONS: We present a case of moderately differentiated pure pancreatic HC. For the accurate preoperative diagnosis of pure pancreatic HC, biopsy is preferred to cytology or preoperative imaging studies such as CT. The prognosis of pure pancreatic HC depends on its differentiation.

A case of emergent operation for a life-threatening infectious mediastinal cyst.

PURPOSE: Congenital mediastinal cysts are an uncommon but important diagnostic group. Most of these cysts are benign and asymptomatic in adults. However, some of them are clinically problematic due to the compression of neighboring organs, infection, or perforation. CASE PRESENTATION: A 20-year-old man presented with severe dyspnea. Imaging revealed a mediastinal cyst in the subcarinal space compressing his right pulmonary artery and airway, which was later diagnosed as a bronchogenic cyst. Due to quick symptom exacerbation, emergent cyst wall fenestration was performed through video-assisted thoracic surgery with "stand-by" extracorporeal membrane oxygenation. Complete cyst resection was difficult owing to adhesion of the cyst to the surrounding organs. The symptoms immediately resolved after surgery and the postoperative course was uneventful. CONCLUSION: Mediastinal bronchogenic cysts with life-threatening complications are rarely reported in adults. However, this case was life-threatening due to airway and vascular compression; emergent surgical care should be considered in such cases.

Postoperative acute exacerbation of interstitial pneumonia in pulmonary and non-pulmonary surgery: a retrospective study.

BACKGROUND: Acute exacerbation of interstitial pneumonia (AE-IP) is a serious complication of pulmonary surgery in patients with IP. However, little is known about AE-IP after non-pulmonary surgery. The aim of this study was to determine the frequency of AE-IP after non-pulmonary surgery and identify its risk factors. METHODS: One hundred and fifty-one patients with IP who underwent pulmonary surgery and 291 who underwent non-pulmonary surgery were retrospectively investigated. RESULTS: AE-IP developed in 5 (3.3%) of the 151 patients in the pulmonary surgery group and 4 (1.4%) of the 291 in the non-pulmonary surgery group; the difference was not statistically significant. A logistic regression model showed that serum C-reactive protein (CRP) was a predictor of AE-IP in the non-pulmonary surgery group (odds ratio 1.187, 95% confidence interval 1.073-1.344, P = 0.002). CONCLUSIONS: This is the first study to compare the frequency of AE-IP after pulmonary surgery with that after non-pulmonary surgery performed under the same conditions. The results suggest that the frequency of AE-IP after non-pulmonary surgery is similar to that after pulmonary surgery. A high preoperative C-reactive protein level is a potential risk factor for AE-IP after non-pulmonary surgery.

Regeneration of esophagus using a scaffold-free biomimetic structure created with bio-three-dimensional printing.

Various strategies have been attempted to replace esophageal defects with natural or artificial substitutes using tissue engineering. However, these methods have not yet reached clinical application because of the high risks related to their immunogenicity or insufficient biocompatibility. In this study, we developed a scaffold-free structure with a mixture of cell types using bio-three-dimensional (3D) printing technology and assessed its characteristics in vitro and in vivo after transplantation into rats. Normal human dermal fibroblasts, human esophageal smooth muscle cells, human bone marrow-derived mesenchymal stem cells, and human umbilical vein endothelial cells were purchased and used as a cell source. After the preparation of multicellular spheroids, esophageal-like tube structures were prepared by bio-3D printing. The structures were matured in a bioreactor and transplanted into 10-12-week-old F344 male rats as esophageal grafts under general anesthesia. Mechanical and histochemical assessment of the structures were performed. Among 4 types of structures evaluated, those with the larger proportion of mesenchymal stem cells tended to show greater strength and expansion on mechanical testing and highly expressed α-smooth muscle actin and vascular endothelial growth factor on immunohistochemistry. Therefore, the structure with the larger proportion of mesenchymal stem cells was selected for transplantation. The scaffold-free structures had sufficient strength for transplantation between the esophagus and stomach using silicon stents. The structures were maintained in vivo for 30 days after transplantation. Smooth muscle cells were maintained, and flat epithelium extended and covered the inner surface of the lumen. Food had also passed through the structure. These results suggested that the esophagus-like scaffold-free tubular structures created using bio-3D printing could hold promise as a substitute for the repair of esophageal defects.

Replacement of Rat Tracheas by Layered, Trachea-Like, Scaffold-Free Structures of Human Cells Using a Bio-3D Printing System.

Current scaffold-based tissue engineering approaches are subject to several limitations, such as design inflexibility, poor cytocompatibility, toxicity, and post-transplant degradation. Thus, scaffold-free tissue-engineered structures can be a promising solution to overcome the issues associated with classical scaffold-based materials in clinical transplantation. The present study seeks to optimize the culture conditions and cell combinations used to generate scaffold-free structures using a Bio-3D printing system. Human cartilage cells, human fibroblasts, human umbilical vein endothelial cells, and human mesenchymal stem cells from bone marrow are aggregated into spheroids and placed into a Bio-3D printing system with dedicated needles positioned according to 3D configuration data, to develop scaffold-free trachea-like tubes. Culturing the Bio-3D-printed structures with proper flow of specific medium in a bioreactor facilitates the rearrangement and self-organization of cells, improving physical strength and tissue function. The Bio-3D-printed tissue forms small-diameter trachea-like tubes that are implanted into rats with the support of catheters. It is confirmed that the tubes are viable in vivo and that the tracheal epithelium and capillaries proliferate. This tissue-engineered, scaffold-free, tubular structure can represent a significant step toward clinical application of bioengineered organs.