During what surgical procedure is the incidence of venous air embolism significantly increased?

The incidence of venous air embolism is significantly increased during a craniotomy due to the specific environmental and positional factors present during the procedure. In particular, craniotomies often involve operating on the head, which can be positioned higher than the heart. This elevation can create a gradient that facilitates the entry of air into the venous system if a venous sinus is breached or if there is a disruption in vascular integrity.

Additionally, during a craniotomy, there is a potential for exposure to atmospheric pressure changes, especially when manipulating the skull. If a surgeon inadvertently opens a venous sinus or if there is a defect in the skull that allows for air entry, the risk of air embolism increases. Such episodes can lead to serious complications, as air bubbles can travel to the heart or lungs, causing obstruction and affecting cardiovascular and respiratory functions.

In contrast, while other surgical procedures like spinal fusion, transurethral resection, and cardiac surgeries can carry risks for embolisms, they are generally not associated with the same elevated risk of venous air embolism seen in craniotomies. The mechanisms involved in those surgeries do not create the same conditions conducive to air entering the venous system as those present during a craniotomy