Endometrioma is the presence of tissue similar but distinct to the endometrium in and sometimes on the ovary. It is the most common form of endometriosis. Endometrioma is found in 17–44% patients with endometriosis. More broadly, endometriosis is the presence of tissue similar but distinct to endometrial tissue located outside the uterus. The presence of endometriosis can result in the formation of scar tissue, adhesions and an inflammatory reaction. It usually is a benign growth. An endometrioma is most often found in the ovary. This ovarian endometriosis forms dark, fluid-filled cysts. These fluid-filled sacs can vary greatly in size and are known as endometriomas, also called "chocolate cysts". The fluid inside the cysts is thick, dark, old blood, giving it a chocolate-like appearance. It can also develop in the cul-de-sac (the space behind the uterus), the surface of the uterus, and between the vagina and rectum. Pathophysiology
Endometrial tissue is the mucous membrane that normally lines the uterus. The endometrium is richly supplied with blood and its growth is regulated by estrogen and progesterone. It consists of glandular and stroma tissue from the lining of the uterus. When the endometrial mucous membrane is found outside of the uterus in places such as the ovaries, it causes chronic pelvic pain with intercourse and menstrual cycles. Endometriomas can produce a toxic environment by producing estrogen, cytokines, interleukins, and other inflammatory substances, that could damage healthy endometriomal tissue.
: 142 In 1982, Quinton together with Dr Sakharam Mahurkar, a nephrologist at County Cook Hospital in Chicago, developed dual-lumen catheter which became the standard for haemodialysis and apheresis.Sheridan was dubbed the "Catheter King" by Forbes magazine in 1988. He also invented the modern "disposable" plastic endotracheal tube now used routinely in surgery. Materials
Urinary catheters
A range of polymers are used for the construction of catheters, including silicone rubber, nylon, polyurethane, polyethylene terephthalate (PET), latex, and thermoplastic elastomers. Silicone is one of the most common implantable choice because it is inert and unreactive to body fluids and a range of medical fluids with which it might come into contact. On the other hand, the polymer is weak mechanically, and a number of serious fractures have occurred in catheters. For example, silicone is used in Foley catheters where fractures have been reported, often requiring surgery to remove the tip left in the bladder. There are many different types of catheters for bladder problems. A typical modern intermittent catheter is made from polyurethane and comes in different lengths and sizes for men, women and children.Some catheters are packed in a sterile saline solution.