How to cite this article: Guevara-Valdivia ME, Aranda-Ayala ZL, Argüello-Hurtado M. Answer to comment on the article “Prevalence and implicated risk factors associated with the exteriorization of cardiac pacemakers...”. Rev Med Inst Mex Seguro Soc. 2016;54(1):77.
LETTERS TO THE EDITOR
Milton E. Guevara-Valdivia,a Zulema Lisbeth Aranda-Ayala,a Marco Argüello-Hurtadoa
aDepartamento de Electrofisiología Cardiaca, Hospital de Especialidades, Centro Médico Nacional La Raza, Instituto Mexicano del Seguro Social, Distrito Federal, México
We appreciate Dr. Vidal Acoltzin’s comments on our publication.1 In our study the delayed type was the most frequent as stated, and although the size of pacemaker generators has been greatly reduced, the edges and the characteristics of these can still influence externalization, so much so that new pacemakers and defibrillators (the latter large in size) have been made with more physiological edges, which shows that the degree of skin pressure on the generator is much lower, unlike those with angled edges, which put more pressure on skin areas and can ultimately produce erosion and be externalized. When the externalization is early, it is the result of contamination, and now with the frequent use of anticoagulants, such as heparin, patients may develop hematomas that, it is well known, are prone to infection. The delayed form is the one in which the generator puts more pressure on the skin, which can cause necrosis, infection, or externalization; however, our study found no significant statistical difference in patients considered at high risk of externalization. We think that there are other factors that predispose to this, and perhaps the incision made at pacemaker implantation could be involved, since the technique and experience of the operator are important points. In our study we did not analyze the technique, although at our hospital we first do dissection of the cephalic vein and if that is not found, we puncture the subclavian or modified axillary; something that we also did not take into account is the procedure time, and we know that surgical exposure may be implicated in externalization. There are antibacterial absorbable covers that include some antibiotic, which decreases the risk of infections.
With respect to sutures, we agree that it is preferable to use either absorbable or non-absorbable monofilament. It is true that sometimes the generator can move, causing the consequences you mentioned, Dr. Acoltzin, especially when pressing on the skin. Another mechanism that may be involved is making a small subcutaneous pocket that predisposes to generator extrusion. Something we take care of during the procedure is to try to expose the electrodes and generator the shortest possible time, so that it is out of its sterile packaging and opened only when it is about to be used, because meticulous asepsis and antisepsis is important. We have not had the chance to read your book, but will soon review it with excitement and interest.