Yusuke Muranishi

Development of a novel tissue-engineered nitinol frame artificial trachea with native-like physical characteristics

Background Tracheal reconstruction is complicated by the short length to which a trachea can be resected. We previously developed a biocompatible polypropylene frame artificial trachea, but it lacked the strength and flexibility of the native trachea. In contrast, nitinol may provide these physical characteristics. We developed a novel nitinol frame artificial trachea and examined its biocompatibility and safety in canine models. Methods We constructed several nitinol frame prototypes and selected the frame that most closely reproduced the strength of the native canine trachea. This frame was used to create a collagen‐coated artificial trachea that was implanted into 5 adult beagle dogs. The artificial trachea was first implanted into the pedicled omentum and placed in the abdomen. Three weeks later, the omentum‐wrapped artificial trachea was moved into the thoracic cavity. The thoracic trachea was then partially resected and reconstructed using the artificial trachea. Follow‐up bronchoscopic evaluation was performed, and the artificial trachea was histologically examined after the dogs were sacrificed. Results Stenosis at the anastomosis sites was not observed in any dog. Survival for 18 months or longer was confirmed in all dogs but 1, which died after 9 months due to reasons unrelated to the artificial trachea. Histological examination confirmed respiratory epithelial regeneration on the artificial tracheas luminal surface. Severe foreign body reaction was not detected around the nitinol frame. Conclusions The novel nitinol artificial trachea reproduced the physical characteristics of the native trachea. We have confirmed cell engraftment, good biocompatibility, and survival of 18 months or longer for this artificial trachea in canine models.

Complete resection of a giant mediastinal leiomyosarcoma.

Primary mediastinal leiomyosarcoma is an extremely rare malignancy, and the only opportunity for a cure lies with an aggressive surgical approach. We report a 66-year-old woman who underwent complete resection of a giant mediastinal leiomyosarcoma located on the bilateral diaphragm. The tumor encased the inferior vena cava and compressed the adjacent structures. Using cardiopulmonary bypass with 20 minutes of hepatic ischemia, the tumor was completely resected with combined resection and reconstruction of the surrounding structures. Because of the tumor size and location in the boundary area between thoracic and abdominal surgeries, the procedure necessitated the cooperation of many expert surgeons.

Three-dimensional Navigation for Thoracoscopic Sublobar Resection Using a Novel Wireless Marking System

We developed a novel localization technique for small intrapulmonary lesions using radiofrequency identification (RFID) technology. Micro-RFID markers with nickel-titanium coils were designed to be placed from subsegmental bronchi to the peripheral parenchyma. In this preclinical study, thoracoscopic subsegmentectomy of a canine pseudotumor model was performed to demonstrate the feasibility and three-dimensional positional accuracy of the system. To recover subcentimeter pseudotumors, markers were bronchoscopically placed to determine the resection line: (1) next to the pseudotumor; (2) in the responsible subsegmental bronchi as the central margin; and (3) on the intersubsegmental plane as the lateral margin. Specific marker positions were located by wireless communication using a wand-shaped probe with a 30-mm communication range, with the distance to the marker indicated by gradual changes in sound pitch. Thirty-four markers were placed for 10 pseudotumors (14.6 mm from the pleura) in 10 canines. Three markers were placed at a mean distance of 5.5 mm from the pseudotumors, and 11 central and 20 lateral markers were placed at mean distances of 17.2 and 20.7 mm from the pseudotumors, respectively. Central markers (20.5 mm from the pleura) were detected within 16.0 seconds in 2.9-mm-diameter bronchi. All resection stumps were within 5.4 mm (range 2-8 mm) from each marker, and pseudotumors were removed with adequate surgical margins toward the central (11.5 mm; range 7-16 mm) and lateral (12.4 mm; range 9-17 mm) directions. RFID wireless markers provided precise three-dimensional positional information and are a potential viable alternative to conventional markers.

Evaluation of a novel multi-articulated endoscope: proof of concept through a virtual simulation

PurposeIn endoscopic surgery such as video-assisted thoracoscopic surgery and laparoscopic surgery, providing the surgeon a good view of the target is important. Rigid endoscope has for years been the go-to tool for this purpose, but it has certain limitations like the inability to work around obstacles. To improve on current tools, a novel multi-articulated endoscope (MAE) is currently under development. To investigate its feasibility and possible value, we performed a user test using virtual prototype of the MAE with the intent to show that it outperforms the conventional endoscope while bringing minimal additional burden to the operator.MethodsTo evaluate the prototype, we built a virtual model of the MAE and a rigid oblique-viewing endoscope. Through a comparative user study we evaluate the ability of each device to visualize certain targets placed inside the virtual chest cavity by the angle between the visual axis of the scope and the normal of the plane of the target, while accounting for the usability of each endoscope by recording the time taken for each task. In addition, we collected a questionnaire from each participant to obtain feedback.ResultsThe angles obtained using the MAE were smaller on average (

Development of a socket-type rib coaptation device made of poly- L-lactide fibers: feasibility study in a canine model

p = 0.01, \text {MD} = 7.25

Development of novel force-limiting grasping forceps with a simple mechanism

p=0.01,MD=7.25), indicating that better visualization can be achieved through the proposed method. A nonsignificant difference in mean time taken for each task in favor of the rigid endoscope was also found (

Atrial fibrillation after lung cancer surgery: incidence, severity, and risk factors

p = 0.42, \text {MD} = -2.09