BEaTS-ß: an open-source electromechanical bioreactor for simulating human cardiac disease conditions.

Heart disease remains the leading cause of worldwide mortality. Although the last decades have broadened our understanding of the biology behind the pathologies of heart disease, ex vivo systems capable of mimicking disease progression and abnormal heart function using human cells remain elusive. In this contribution, an open-access electromechanical system (BEaTS-ß) capable of mimicking the environment of cardiac disease is reported. BEaTS-ß was designed using computer-aided modeling to combine tunable electrical stimulation and mechanical deformation of cells cultured on a flexible elastomer. To recapitulate the clinical scenario of a heart attack more closely, in designing BEaTS-ß we considered a device capable to operate under hypoxic conditions. We tested human induced pluripotent stem cell-derived cardiomyocytes, fibroblasts, and coronary artery endothelial cells in our simulated myocardial infarction environment. Our results indicate that, under simulated myocardium infarction, there was a decrease in maturation of cardiomyocytes, and reduced survival of fibroblasts and coronary artery endothelial cells. The open access nature of BEaTS-ß will allow for other investigators to use this platform to investigate cardiac cell biology or drug therapeutic efficacy in vitro under conditions that simulate arrhythmia and/or myocardial infarction.

Longitudinal Outcomes Following Surgical Repair of Primary Mitral Regurgitation.

Degenerative mitral valve (MV) disease is the most common cause of organic mitral regurgitation (MR) in developed countries. Surgical mitral valve repair is the gold standard treatment for primary MR. Surgical mitral valve repair is associated with excellent outcomes in terms of survival and freedom from recurrent MR. As well, innovations in surgical repair techniques, including thoracoscopically and robotically assisted approaches, further reduce morbidity. Emerging catheter-based therapies may also provide advantages in select patient groups. Although the outcomes following surgical mitral valve repair are well described in the literature, longitudinal follow-up is heterogenous. Indeed, longitudinal follow-up and long-term data are vital to better advise treatment and counsel patients.

Maximization of the sealing effect of fibrin glue in aortic surgery.

OBJECTIVES: Fibrin glue is used to reinforce anastomosis in aortic surgery. There has not yet been a consensus on how it should be applied optimally. This study aimed to define the optimal condition of applying fibrin glue. METHODS: In experiment 1, we determined the optimal condition for spraying fibrin glue using an expanded polytetrafluoroethylene graft within a needle hole. The length and area of the fibrin cap within the hole were measured. In experiment 2, methods for applying fibrinogen were assessed by comparing brushing and spraying. In experiment 3, swine aorta segments sutured with a Dacron graft were divided into the following three groups: nothing was applied; fibrinogen was sprayed and rubbed using brush. The aorta was clamped and blood was infused from an occlusion catheter inserted into the graft. The pressure at the first appearance of blood leak was recorded. RESULTS: In experiment 1, among the four groups divided by the pressure and distance of spraying, the fibrin cap area in the group with 0.075 MPa and 2-cm spray distance was significantly larger than that in the group with 0.15 MPa and 2 cm (P < 0.01). In experiment 2, the fibrin cap area in the brushing group was significantly larger than that in the spraying group (P < 0.05). In experiment 3, the capacity to resist endoluminal pressure was higher in the brushing and combined spraying group compared with that in the sequential combined spraying group (P < 0.01). CONCLUSIONS: The brush and spray methods showed excellent hemostatic outcomes.

[Splenic Injury during Replacement of the Thoracoabdominal Aorta].

Extraperitoneal approach is commonly employed for thoracoabdominal aortic repair via Stoney incision. It is supposedly rare to encounter abdominal visceral bleeding during that procedure. However, the spleen may spontaneously adhere to the adjacent peritoneum, which could induce incidental injury to the spleen by its anterior mobilization during extraperitoneal approach. Unless we bare its potential risk in mind, bleeding from the spleen may be overlooked, which results in hemodynamic deterioration. We have experienced 3 cases of splenic injury that necessitated hemostatic maneuvers for bleeding during and just after the thoracoabdominal aortic repair.

Morphometrical and biomechanical analyses of a stentless bioprosthetic valve: an implication to avoid potential primary tissue failure.

OBJECTIVES: Stentless bioprosthetic valves provide hemodynamic advantages over stented valves as well as excellent durability. However, some primary tissue failures in bioprostheses have been reported. This study was conducted to evaluate the morphometrical and biomechanical properties of the stentless Medtronic Freestyle™ aortic root bioprosthesis, to identify any arising problem areas, and to speculate on a potential solution. METHODS: The three-dimensional heterogeneity of the stentless bioprosthesis wall was investigated using computed tomography. The ascending aorta and the right, left, and non-coronary sinuses of Valsalva were resected and examined by an indentation test to evaluate their biomechanical properties. RESULTS: The non-coronary sinus of Valsalva was significantly thinner than the right sinus of Valsalva (p < 0.01). Young's modulus, calculated as an indicator of elasticity, was significantly greater at the non-coronary sinus of Valsalva (430.7 ± 374.2 kPa) than at either the left (190.6 ± 70.6 kPa, p < 0.01) or right sinuses of Valsalva (240.0 ± 56.5 kPa, p < 0.05). CONCLUSIONS: Based on the morphometrical and biomechanical analyses of the stentless bioprosthesis, we demonstrated that there are differences in wall thickness and elasticity between each sinus of Valsalva. These differences suggest that the non-coronary sinus of Valsalva is the most vulnerable and at greater risk of tissue failure. The exclusion of the non-coronary sinus of Valsalva may be beneficial to mitigate the long-term risks of tissue failure in the stentless bioprosthesis.

[A recurrent gastric cancer with peritoneal metastasis 15 years after distal gastrectomy successfully treated with S-1 and weekly intravenous and intraperitoneal injections of Paclitaxel].

Fifteen years after receiving a distal gastrectomy for advanced gastric cancer, a 70-year-old woman was admitted to our hospital because of abdominal fullness due to ascites. Although cytological examination showed adenocarcinoma cells in the fluid, no examination revealed the primary lesion. Peritoneal metastasis was detected via immunohistochemistry using the cell block technique. After chemotherapy failure (S-1 plus CDDP, weekly PTX, and S-1 plus DOC), the patient received S-1 and weekly intravenous and intraperitoneal injections of PTX. The ascites decreased, and she has been doing well. Our experience with this case suggests that S-1 and weekly intravenous and intraperitoneal injections of PTX is a promising means of treating gastric cancer with peritoneal metastasis.

[A case of superior mesenteric artery occlusion with ischemic enteritis after transcatheter therapy].

An 84-year-old female was admitted with sudden-onset upper abdominal pain. Contrast-enhanced computed tomography (CECT) revealed complete occlusion of the superior mesenteric artery (SMA). After transcatheter infusion of urokinase, embolic occlusion resolved. However, the pain recurred when she started eating. CECT revealed a lesion with thickening of the intestinal wall; therefore, laparoscopy-assisted surgery was undertaken. Histological examination yielded a definitive diagnosis of ischemic enteritis caused by SMA occlusion. Rapid diagnosis and treatment are important in SMA occlusion, and careful observation of the clinical course is recommended after transcatheter therapy.

[Pancreatic pseudocyst with fistula to the common bile duct and the duodenum].

A 35-year-old man was hospitalized for severe acute pancreatitis. On the 24th hospital day, CT scan showed a pancreatic pseudocyst in the head of the pancreas. Conservative medical treatment for 1 month was not effective, and CT scan revealed a fistulous communication of the pseudocyst to the common bile duct and duodenum. After the formation of a fistulous communication, we detected common bile duct stones composed of fatty acid calcium and we removed them endoscopically. The pseudocyst gradually decreased in size and disappeared 4 months later. Follow-up CT scan showed no sign of recurrence.