Abstract
Dear Editors,
I would like to thank the authors of ‘Effectiveness of a bipolar vessel sealant device for ovariohysterectomy in cats with pyometra’ 1 for their study on the interesting topic of this rare clinical disease. I have read the article with great interest and wish to raise a couple of critical questions and add some comments.
First of all, I would like to point out that it is not best veterinary practice to undertake clinical studies on client-owned animals without performing any experimental studies in advance; especially when the animals are affected by a life-threatening disease such as pyometra. Therefore, I wonder how an ethical committee could approve the study and what the owner consent form looked like, and ask if the authors could provide the ethical approval number and the owner consent form.
Regarding the Caiman vessel sealant device (VSD), it is not mentioned if a new VSD was used for every patient or not. If not, a description of how the VSDs were cleaned and resterilised, and how often each VSD was used and how this was selected is an important omission. In addition, how did the authors decide where to place the VSD? From Figure 1, it looks like it was specifically placed at the level of the cervix; if so, why was this position chosen? Also, how was the number of three sealing cycles selected and were those seals all performed at the same position? If not, between which seals was the tissue transected and how was this decided?
In the results section it is stated that there were no signs of peritonitis detected during the follow-up examinations, but I wonder how this could be determined, since there was no ultrasound performed at any time point? How could it be assured that the uterus would not open up after the healing period and that there was a tight seal? Since the collagen ratio in the uterus is so different from vessel walls, we cannot assume that there will be a reliable seal at the uterus as well without testing this with histopathologic studies using the Caiman VSD on the uterus.
Because of the above-stated arguments, I consider that this study has several weaknesses. Furthermore, the Caiman VSD should not be safely recommended for sealing the uterus without any further experimental studies to prove that it will create a reliable seal and to determine up to which diameters it can be safely used.
