True and “Choke” Anastomoses between Perforator Angiosomes

Sir: We read with great interest the recent article by Taylor et al. entitled “True and ‘Choke’ Anastomoses between Perforator Angiosomes: Part I. Anatomical Location,”1 in which the authors accurately described the connections between perforator angiosomes. Nevertheless, we would like to highlight some points on this issue. In the era of perforator flaps, an accurate knowledge of angiosomes is a very important matter for a plastic surgeon. Consequently, the description of “true” and “choke” anastomoses between angiosomes and the role that their caliber plays in these connections become a very useful tool when choosing the correct territory during flap harvest.2 However, there is one issue we believe must be considered when arguing about “choke” vessels. As Professor Ian Taylor stated, vessel diameter has a critical role in the final perfusion. The present study was performed on cadavers, but as we already privately discussed with the senior author, the situation in reality could be different. This is based on the idea that a dynamic and open system, as in a living being, is different from a static system, as in a cadaver. The authors analyzed the vessel caliber as the main factor in the control of blood flow because their work was only based on the study of cadavers. If this can be considered acceptable in a cadaver model, other factors could be involved in the regulation of vessel diameter in living bodies. The nervous stimulation, the metabolic balance (NO, acidity, temperature, pO2, pCO2, Mg++, K+), and the endothelial control, in addition to the muscular pump, can play a major role in the final results we achieve during and after surgery. As described in the article, a “choke” anastomosis occurs when the connection between the angiosomes is made between reduced-caliber vessels. In a more complex context, choke vessels may play a dynamic role and may respond to several stimuli with a specific modification of their flow. In conclusion, a vessel that could appear “choked” in a cadaver may be a dynamic vessel in the living body. As the authors stated in their article, there is strong individual and interindividual variability regarding the perforator angiosomes. Also, a different response to neurohumoral stimulation or a different hormonal environment could modify the flow range through a modification of the vessel’s caliber or blood pressure, according to Poiseuille’s law. Nevertheless, we are aware of the fact that anatomical studies serve as a baseline, and that is very difficult to recreate all the conditions we see physiologically in the operating room. We are thankful to the authors for their important work and conclude by recalling the senior author’s statement: “We need to persist, do, and try.” DISCLOSURE The authors have no financial interest to declare in relation to the content of this communication. No outside funding was received. Pierluigi Gigliofiorito, M.D. Plastic and Reconstructive Surgery Unit Università Campus Bio-Medico di Roma Rome, Italy Iacob Sinziana, M.D. Clinical Emergency “Floreasca” Hospital Bucharest, Romania Alfonso Luca Pendolino, M.D. Luca Piombino, M.D. Francesco Segreto, M.D. Paolo Persichetti, M.D., Ph.D. Plastic and Reconstructive Surgery Unit Università Campus Bio-Medico di Roma Rome, Italy