However, the safety and effectiveness of each procedure must be demonstrated with randomized controlled trials. The term was coined by John E. A. Wickham in 1984, who wrote of it in British Medical Journal in 1987. Specific procedures Many medical procedures are called minimally invasive; those that involve small incisions through which an endoscope is inserted, end in the suffix -oscopy, such as endoscopy, laparoscopy, arthroscopy. Other examples of minimally invasive procedures include the use of hypodermic injection, and air-pressure injection, subdermal implants, refractive surgery, percutaneous surgery, cryosurgery, microsurgery, keyhole surgery, endovascular surgery using interventional radiology (such as angioplasty), coronary catheterization, permanent placement of spinal and brain electrodes, stereotactic surgery, the Nuss procedure, radioactivity-based medical imaging methods, such as gamma camera, positron emission tomography and SPECT (single photon emission tomography). Related procedures are image-guided surgery, and robot-assisted surgery. Equipment Special medical equipment may be used, such as fiber optic cables, miniature video cameras and special surgical instruments handled via tubes inserted into the body through small openings in its surface. The images of the interior of the body are transmitted to an external video monitor and the surgeon has the possibility of making a diagnosis, visually identifying internal features and acting surgically on them. Benefits Minimally invasive surgery should have less operative trauma, other complications and adverse effects than an equivalent open surgery. It may be more or less expensive (for dental implants, a minimally invasive method reduces the cost of installed implants and shortens the implant-prosthetic rehabilitation time with 4–6 months). Operative time is longer, but hospitalization time is shorter. It causes less pain and scarring, speeds recovery, and reduces the incidence of post-surgical complications, such as adhesions and wound rupture. Some studies have compared heart surgery. Risks Risks and complications of minimally invasive procedures are the same as for any other surgical operation, among the risks are: death, bleeding, infection, organ injury, and thromboembolic disease. There may be an increased risk of hypothermia and peritoneal trauma due to increased exposure to cold, dry gases during insufflation. The use of surgical humidification therapy, which is the use of heated and humidified CO2 for insufflation, may reduce this risk. Invasive procedures Sometimes the use of non-invasive methods is not an option, so that the next level of minimally invasive techniques are looked to. These include the use of hypodermic injection (using the syringe), an endoscope, percutaneous surgery which involves needle