Harriet Jones, Reem Ahmed, Mohammed Anabtawi, Muzzammil A Nusrath
Patients are living longer with implantable permanent pacemakers and often need surgery in close proximity to the pacemaker. Electro Magnetic Interference (EMI) can occur when an electromagnetic source comes in direct contact with the body. This type of EMI can be generated by electrocautery, defibrillation, MRI and PET scans. Use of electrocautery might inhibit or trigger the pacemaker in demand modes, damage the pacing system, or its automatic safety reversion mode during surgery, and can lead to thermal damage of the heart through the lead electrode. The use of bipolar diathermy is a safer, but not an absolute safe alternative. Furthermore tissue cutting and dissection is not possible with bipolar cautery. The proximity of pacemaker device to electrocautery, especially during level 4 Neck dissection, increases these concerns.
We present our experience in a 69 year old male with permanent DDDR pacemaker who needed a SND and Parotidectomy for metastatic SCC of Skin. We used a Harmonic Scalpel and this did not lead to any issues with the heart monitor or a change in the ECG rhythm. Harmonic scalpel transforms electric power into longitudinal movement by a piezoelectric transducer situated in the hand piece. Its mechanism of action involves cavitations, heat generation and coagulation by protein denaturation. Mechanical oscillation of the instrument causes rapid rise and fall in temperature of the tissues. Vapour filled cavities are formed within cells. It is the force generated by expansion and contraction resulting in tissue dissection. Heat is generated due to internal tissue friction caused by high frequency vibrations. Coagulation is produced by denaturing proteins through mechanical disruption of tertiary hydrogen bonds.
We would recommend Harmonic scalpel as a safe dependable device which both divides tissue and achieves haemostasis for patients with pacemakers, cochlear implants and other implantable devices which are susceptible to EMI.