Laparoscopic instruments – websurg – cirugía laparoscópica en websurg, la referencia quirúrgica en línea dolor lumbar izquierdo

• Degrees of freedom Most laparoscopic instruments, i.e. graspers and scissors, have basic opening and closing functions. Many instruments manufactured during the past few years are able to rotate 360 degrees, which increases the degrees of freedom of movement of the instrument. However, many of these instruments are designed to prevent rotation when the instrument is tightly closed (e.g.; during tissue clamping). This may facilitate tissue retraction but can be a disadvantage if the surgeon wishes to rotate the grasped tissue.

A certain number of instruments offer angulation at their tip, in addition to the usual 4 degrees of freedom. These instruments are used to avoid obstacles and for lateral grasping when the instrument is placed outside of the visual field. Angulation features are available both for reusable and disposable instruments. However, the complex mechanisms of such instruments make sterilization very difficult, so manufacturers tend to offer a larger range of disposable versions of these instruments.

• Sterilization and cleaning The sterilization of surgical instruments must comply with safety standards. These vary depending upon the legislation of individual countries each of which may which require different sterilization systems and sterilization times. For example:

– American legislation: AAMI TIR No. 12 – 1994: Designing, testing, and labeling reusable medical devices for reprocessing in Health Care Facilities: A Guide for Medical Device Manufacturers. This document is the primary one referred to by the Food and Drug Administration (FDA) for sterilization validation and criteria regarding sterilization of reusable devices.

ANSI/AAMI ST81:2004: Sterilization of Medical Devices – Information to be Provided by the manufacturer for the Processing of Resterilizable Medical Devices (This is the same, with some minor exceptions as BS EN ISO 17664: 2004 Sterilization of Medical Devices – Information to be Provided by the Manufacturer for the Processing of Resterilizable Medical Devices).

Instruments require cleaning systems that are adapted to the way they are designed. Some instruments can be dismantled and each piece can be cleaned independently. Other instruments cannot be dismantled but are equipped with a flush port. The flush port requires abundant rinsing (300 cc) under pressure at the end of each usage. Incomplete cleaning followed by a high temperature autoclave sterilization will cause coagulation of proteins in the flush port channels and articulations leading to malfunction.

A standard IV giving set bag usually containing normal saline is placed within a pressure cuff. The bag is then pressurized. Irrigant can then be flushed into the operative field via the suction-irrigation instrument. The flow is controlled by a valve on the instrument handle. This type of system is not powerful enough for hydro-dissection, and cannot inject large quantities of fluid into the peritoneal cavity for an efficient lavage.

This system uses the principle of the vacuum pump. They are disposable systems that are hooked up to the operating room compressed air system. A pressure transfer system uses the hyperpressure of the compressed air to pressurize the irrigation fluid. These relatively inexpensive, disposable systems enable surgeons to have high pressure irrigation at all times.

The use of high flow, high pressure irrigation systems during laparoscopy involves the risk of significantly increasing the intra-abdominal pressure. The most powerful irrigation systems can inject several liters of fluid per minute into the abdomen. This volume will increase the intra-abdominal pressure accordingly. It is mandatory to arrange for systematic evacuation of the pneumoperitoneum or to work with an insufflator equipped with an automatic exsufflation system capable of preventing excessive pressure.