simon wapnick (2 resultados)

Condición: Good. Pages intact with minimal writing/highlighting. The binding may be loose and creased. Dust jackets/supplements are not included. Stock photo provided. Product includes identifying sticker. Better World Books: Buy Books. Do Good.

Soft cover. Condición: Very Good. No Jacket. 1st Edition. A scarce monograph documenting an important development in the history of medicine and surgery for the control of ascites secondary to liver disease. Softcover, stapled wraps, printed/illustrated front cover, 8 7/8 x 5 7/8 inches, 61 pp., references, figures. Very good plus (mailing and postal labels, rear cover). (K011) The LeVeen shunt was the first widely successful, clinically viable device to employ the peritoneovenous method of controlling ascites. Introduced by Dr. Harry H. LeVeen in 1974, it completely revolutionized the management of refractory ascites by establishing a way to continuously cycle fluid back into the venous system using a pressure-sensitive, one-way valve. While it was the first design to gain massive global adoption and mainstream clinical success, it belongs to a timeline of specialized medical evolution: 1. Predecessors and Early Concepts (Before 1974) Before Dr. LeVeen's design, physicians experimented with early variations of peritoneovenous shunting?such as the experimental Hyde shunt used between 1964 and 1974. However, these early attempts struggled heavily with immediate clogging, backward blood flow, and severe surgical complications, meaning they never achieved widespread clinical validation. 2. The LeVeen Breakthrough (1974) Dr. LeVeen solved the backflow issue by engineering a unidirectional valve that opened only when the pressure in the abdominal cavity grew higher than the pressure in the central veins. This structural breakthrough allowed the medical community to adopt the device en masse, with thousands of placements performed globally through the late 1970s and 1980s. 3. Subsequent Evolution (1979 and Beyond) Though revolutionary, the LeVeen shunt required a strict pressure gradient to flow and was highly prone to clotting if the fluid became too thick. To fix this, the Denver shunt was introduced in 1979. It utilized LeVeen's core concept but added a flexible, subcutaneous pump chamber that patients or doctors could manually squeeze to flush out debris and keep the tube clear. Because the Denver modification drastically reduced valve failure, the original LeVeen design fell out of favor and was eventually discontinued in the late 1990s. (K011).