Artificial Trachea, by Chris Carr

Background

Figure 1. Diagram of a trachea [A]

The trachea, also known as the windpipe, is the passage way that leads air to your lungs. It is made up of cartilage, muscle and connective tissue. Tracheas are often around 4 inches long which are comprised of approximately 20 cartilage rings. On the inside lining of the trachea is a mucus membrane that is able to catch harmful airborne particles and bacteria before it reaches your lungs. Swallowing and sneezing are ways of removing these particles [4C].

Breathing involves two main steps; oxygen enters the body when you breathe in and carbon dioxide leaves the body when you exhale. When someone takes a breath, oxygen goes through the nose and mouth down their trachea. From here the trachea splits up into two bronchi tubes which lead to the left and right lung. Next the oxygen travels through the smaller branches, bronchioles, to millions of small alveoli located throughout the lungs. Alveoli are small sacs in the lungs that allow for the exchange of gases with the blood stream. Here oxygen is exchanged with carbon dioxide. The red blood cells deliver the oxygen to the rest of the body while the carbon dioxide is expelled out the same way the oxygen came in. Too avoid food and drink from entering the lungs, a flap known as the epiglottis, closes while swallowing in order to prevent them from entering the trachea and lungs [5c].

[AC] http://www.webmd.com/lung/picture-of-the-trachea [4C] webmd.com [5C] http://www.ehow.com/how-does_4565395_breathing-process-work.html

History

1981 - Start of skin tissue engineering of epithelial cells [2c]

2008 - First cadaver trachea transplant seeded with patients own cells by Macchiarini[1c,9c]

2010 - Macchiarini performed first artificial trachea implanted with patient's stem cells [1c,9c]

DATE - dog trials or other animals with artificial trachea or other animals??????????

[1C] http://singularityhub.com/2011/07/09/in-medical-first-doctors-implant-lab-grown-synthetic-trachea-into-patient/

[2C] http://www.medscape.com/viewarticle/470251_3

[9c] http://articles.baltimoresun.com/2012-01-13/health/bs-hs-trachea-transplant-20120112_1_tumor-windpipe-trachea

Health Issues

Many diseases can affect the trachea and diagnosis may be complicated by generalized symptoms such as coughing, wheezing, and shortness of breath. As a result, these diseases can become fatal if not treated or detected fast enough. Computed tomography (commonly referred to as CT) is often used to diagnose trachea abnormalities caused from disease or illness. Diseases of the trachea that can benefit from a trachea replacement are:[6c]

Tracheal Cancer: Although rare, tracheal cancer is very fatal if undetected right away (5% survival rate). Tracheal neoplasms are lumps or growths which can result in malignant tumors. There are two types of neoplasms, one of which is benign while the other is malignant. These are usually detected by a CT scan. Benign neoplasms would most likely be surgically removed while malignant neoplasms would benefit from a full trachea replacement. A majority of tracheal tumors are a result of these malignant neoplasims which is most commonly squamous cell carcinoma (the second most common form of non-melonma skin cancer, common in head/neck cancers). [6c,7c] Tracheal stricture – Is an abnormal narrowing of the trachea which is usually caused because of trauma to the neck. It can be cured by temporary enlargement using tracheal dilation (last few days-6 months), resection (cut and sewn back together to enlarge), or a full trachea replacement. [6c]

Tracheomalacia – Is a weakness of the trachea walls which leads to collapsed airways, this is common in children with cartilage deficiencies. This can also be caused in adults due to injury or smoking. This typically is not serious enough for surgery but in extreme cases replacement may be necessary [4c, 6c].

Turburulosis – stent failed need transplant [need source]

[6c] http://radiographics.rsna.com/content/12/4/645.full.pdf (peer reviewed) [7c] http://emedicine.medscape.com/article/425904-overview

Current Technology

Transplants

cadavers

Artificial Trachea

PET material