Editing Endoscopic electrosurgery


== Preparation ==

* Be aware of metal jewellery or metalwork
* Bowel prep - methane gas (which can be associated with mannitol preparations) can explode

== Monopolar ==

* Functions: resect, cut, coagulate mucosal lesions
* Hot polypectomy snare, or hot biopsy forceps, or monopolar EMR knives
* Hot polypectomy:
** Use either modulated low-voltage (blended) or modulated high-voltage (coag). Pure cutting has the highest risk of post-polypectomy bleeding. Coag has a higher risk of delayed bleed, while blended has a higher risk of immediate bleed.
** Some people use coag to blanch the tissue followed by blended to pull through
** Can also do saline lift and tenting the mucosa at the base of the polyp.
** Don't allow the snare to be tightened too quickly

== Bipolar: ==

* Radiofrequency array for ablation of oesophageal mucosa, and multipolar electrocoagulation probe  (gold probe)

== APC ==

* Achieves superficial coagulation of the GI mucosa without deeper thermal injury
* Good for ablating AVMs and radiation proctitis
* Thin-walled areas - 20W modulated high voltage is usually sufficient
* Thick-walled areas - 40-60W may be used
* Adjust effect by modulating flow rate of argon and the configuration of the APC probe
* Evacuate the argon gas intermittently throughout the procedure to prevent overdistension

== Complications ==

* Perforation
** Related to thickness of wall - be very careful in caecum and duodenum, while stomach and rectum are much thicker
** Current density is highest at the base of the polyp - if broad-based, it requires more energy to cut, and full-thickness injury is more likely
** Saline lift can buffer the muscularis propria from thermal energy
** The smallest snare and lowest power settings should be used
* Direct coupling
** Can occur with failure to fully push instrument out of channel of scope
** Also when a large polyp rests against the opposite wall - prevent this by jiggling the snare to shift the focus of the polyp around

[[Category:Endoscopy]]