Dr R. K. Mishra
What is Active Electrode Monitoring System?
Since the 1930s, the electrosurgery unit (ESU) has been the standard surgical tool, used to cut, coagulate, and vaporize tissue. Active electrode monitoring is used for identifying the diffect in insulated instrument of laparoscopic surgery and this technology make laparoscopic surgery safe, cost-effective, and does not significantly affect the surgeon's clinical surgical technique or time. The stray electrosurgical energy that causes burns is a result of insulation failure, capacitive coupling, and direct coupling. Active electrode monitoring system is a system in which shielded and monitored instruments continuously direct stray energy, the cause of stray electrosurgical burns, away from the patient via a protective shield. Every time when a laparoscopic surgeon steps on the monopolar foot pedal during laparoscopic surgery, the patient is at risk for a potentially fatal stray electrosurgical burn. Burns due to electrosurgery are caused by stray energy resulting from insulation failure or capacitive coupling.
During laparoscopic surgery unlike external skin burns at the site of the patient return electrode, which are usually recognized immediately following a surgical case, stray electrosurgical burns occur inside abdomen also and more often not in the view of the laparoscope. Sometime without the knowledge of surgeon this insulation failure and capacitive coupling may cause electrical current to come in contact with non-target tissue, causing unintended injury. Active Electrode Monitoring (AEM) system continuously monitors laparoscopic instruments during surgery, eliminating the risk of stray energy burns to patients. If insulation is damaged, the AEM Monitor will sound an alarm andit will light the indicators.
What are the causes of these insulation failure?
The life expectancy of a reusable instrument is limited and it is average calculated at about one year. With emphasis on cost containment in laparoscopic surgery, facilities are using instrumentation beyond their expected life. Most laparoscopic hospitals have no formal protocol for testing to ensure that the laparoscopic surgeon is handed an laparoscopic instrument free from insulation failure.
Inspection of laparoscopic instruments before and after surgical use may help reduce the electrosurgical risk, but because this examination technique is user-dependent, it is not free from risk. Minute insulation defects of laparoscopic instrument cannot be detected by even the most vigilant of surgeon or staff and inspection does not totally make it possible to prevent insulation failure from occurring during a minimal access surgical procedure.
In Laparoscopic Instrument insulation failure can occur as a result of the constant introduction and removal of the laparoscopic instrument during minimal access surgery, high voltages, general handling, and the stresses of sterile processing. A small insulation defect is actually more dangerous during laparoscopic surgery than a large one; the smaller the defect, the higher the current density transferred to nearby non-target tissue, the greater the chance of an electrosurgical burn in laparoscopic surgery. A high-voltage waveform such as those used during laparoscopic coagulation will create a larger hole in the insulation or create a hole in weak insulation.
What are the causes of these capacitative coupling?
During laparoscopic surgery capacitive coupling can also cause stray electrosurgical burns. As the number of laparoscopic surgery is performed has increased in recent years, the need to lessen the responsibility of processing laparoscopic instruments has resulted in facilities using disposable laparoscopic instruments and trocars as well as reusable laparoscopic instruments. The mixing of reusable and disposable laparoscopic instruments, which also mixes conductive and non-conductive materials, facilitates capacitive coupling.
What is the Advantage of AEM System?
Laparoscopy has made a significant impact in the past decade. During laparoscopic surgery, the surgeon views the peritoneal cavity through laparoscopic cameras introduced into the abdominal cavity through small ports. Thus, the surgeon's field of view is limited to 5 to 10 cm. Stray electrosurgical energy occurring outside this field of view can cause unintended burns to non-target tissue, and these burns usually go unnoticed. During laparoscopic surgery surgeon has to use long insulated instrument and In the event insulation failure or in case of capacitively coupled energy if reaches dangerous levels, the electrosurgical unit (ESU) immediately shuts down automatically and the surgical staff and surgeons or gynecologists are alerted. With the high quality AEM system, the patient is never at risk for stray electrosurgical burns due to insulation failure and capacitive coupling.
AEM system detects even the smallest full thickness insulation breaks on 5-mm and 10-mm Laproscopic and Endoscopic instruments, virtually eliminating accidental burns due to faulty insulation, saving costs and reducing the possibility of patient injury.
Is there any alternative of Active electrode monitoring system?
Visual Inspection is possible to inspect insulation failure. One of the two main causes of stray electrosurgical burns in laparoscopy is insulation failure and another is capacitative coupling. Conventional monopolar laparoscopic instruments contain a single layer of insulation which can be easily inspected if surgeon will inspect it carefully.