日本語 The Lung Group
A New Approach to Seal Intraoperative Lung Air Leaks Using Dermal Fibroblast Cell Sheets
In chest surgery, lung air leaks are often observed after thoracic procedures and are a peculiar complication in addition to other complications such as bleeding and infection. Various surgical techniques and biological sealant have been applied to resolve intraoperative air leaks. However, improved techniques have not enough and have been decreasing few complications. To now, pleurodesis which lead to pleural adhesion by autologous blood or many antibiotics have been performed for prolonged lung air leaks. Conversely, other general surgeries avoid and prevent such adhesion. Pleurodosis causes fever-up, chest pain, and shock. Moreover, resulting in pleurodosis, patients lead to cause decreased pulmonary function. As a result of prolonged air leak, in some patients have undergone reoperation. In thoracoscopic surgery, the lung and chest wall sometimes do not adhere because intrathoracic manipulations are different from that of conventional open chest surgery. For these reasons there are some cases of lung air leaks that present major problems after chest surgery.
It is expected that the tight sealing of intraoperative air leaks will be effective in reducing the chest cavity drainage period after an operation, as well as the length of hospital stay. Though the sealing of intractable and prolonged air leaks have been achieved using the adhesion procedure, in cases requiring repeated operations, such as recurrence of malignancy, adhesion to the thoracic cavity has to be avoided. This is because operating time would have to be prolonged due to the necessity of dissecting the previously adhersion, and also because a new air leak may occur. The ideal tissue adhesive is easy to handle and can attach stably and contour to the wet surfaces of lungs to immediately seal intraoperative air leaks.
At present, there has been no clinical use of adhesive materials that have both strong adhesiveness and low toxicity. Promisingly, however, many cells make bonds for cell-to-cell adhesion, and in addition, under the lower surface of cells, there exist extra matrix-cellular components, the collagen and the fibronectin. All of these substances are accumulated in the course of cultivation of cells in sheet form, enabling them to acquire the adhesive function required. This is why we can use cell sheets to make tissues, for they mutually adhere together. Exploiting these characteristics, we have developed a new surgical procedure that is distinctively different from previous surgical methods and materials. To date, we have confirmed the usefulness of sealing air leaks by utilizing dermal fibroblast sheets both in small animal models with pleural injuries and also in large animals such as swine. Currently we are working on verifying the optimization of cell-sheet-fabrication conditions and others, utilizing human dermal fibroblasts.
Fig.1：
A Collected Human Dermal Fibroblast Sheet
←Click to enlarge
Fig.2：
A dermal fibroblast sheet was applied to a rat air-leak model to seal the lung air leak. When the chest was opened three months after transplantation, the area was white in color and was covered with the sheet.
↑Click to enlarge
Researcher Introduction
Thoracic Surgery /
Institute of Advanced BioMedical Engineering and Science (Joint Appointment),
Associate Professor Masato KANZAKI
Thoracoscopic surgery has become the mainstay in surgeries such as lung cancer, spontaneous pneumothorax and other pulmonary diseases. Especially to the advancement in surgical tools including artificial materials, and surgical instruments such as throrascopes, safe and improved surgical operations are now provided to patients. However, lung air leaks, which have been regarded as troublesome since the beginning of chest surgery, still worry chest surgeons today. Due to the prolonged period of air leaking after surgery, patients face a long hospital stay with a thoracostomy tube inserted in their thoracic cavities. Therefore, we are devoting ourselves unreservedly to achieving a new and reliable method of sealing air leaks for lung-air-leak through the clinical application of cell sheets.
Achievements
- Maeda M, Yamato M, Kanzaki M, Iseki H, Okano T. Thoracoscopic cell sheet transplantation with a novel device. J Tissue Eng Regen Med. 2009;3(4):255 - 9.
- Kanzaki M, Yamato M, Yang J, Sekine H, Takagi R, Isaka T, Okano T, Onuki T. Functional closure of visceral pleural defects by autologous tissue engineered cell sheets. Eur J Cardiothorac Surg. 2008;34(4):864 - 9.
- Kanzaki M, Yamato M, Yang J, Sekine H, Kohno C, Takagi R, Hatakeyama H, Isaka T, Okano T, Onuki T. Dynamic sealing of lung air leaks by the transplantation of tissue engineered cell sheets. Biomaterials. 2007;28(29):4294 - 302.
