We appreciate the comments and questions from Drs. Dubar and Fischler regarding our article.1
We agree that the detection of a patent foramen ovale (PFO) would have been enhanced if we had used the methods that they had recommended. Because the incidence of PFO in Koreans has been well known,2,3our focus was not the incidence of PFO in this study.
We also tried to find bubbles in the left heart, especially PFO cases and any neurologic complications after surgery, but we did not find any. However, if we had conducted postoperative cognitive function test, such as the Mini Mental State Examination,4minor neurologic complications might have been found.
Although animal studies found no benefit from the left-lateral decubitus (Durant's) position in improving hemodynamic performance, it can allow gas bubbles to rise into the apex of the right atrium. So, it may be helpful for trapping and aspirating bubbles entrained in the right atrium.
As one of the specialists in diving medicine, the corresponding author (K.J.K.) totally agrees with them that hyperbaric oxygen therapy has potential benefits for arterial air embolism and cerebral air embolism.
The major reason why systemic complications resulting from paradoxical embolism with carbon dioxide are rare may be because of the high solubility of carbon dioxide in blood (0.60 ml CO2/ml blood).5Air embolism can be rapidly transformed into a nonair embolism because of the adhesion of platelets to the bubble, as they had pointed out. However, endothelial cells are important because they can be damaged by bubbles that are small enough to pass through the blood circulation without obstructing the blood flow.
In contrast to laparotomy, laparoscopic surgery has several benefits such as improved and more rapid recovery, reduced postoperative fatigue, heightened feeling of well-being, and better maintenance of homeostasis.6–8Moreover, clinically significant carbon dioxide embolism is rare (0.001%) during laparoscopic procedures9,10unlike PFO whose incidence is relatively high. Therefore, we believe that PFO cannot be a ground for eliminating laparoscopic surgery from possible surgical treatments.
*Anesthesia and Pain Research Institute, Yonsei University College of Medicine, Seoul, Korea. email@example.com