Laparoscopic surgery, sometimes called “keyhole surgery,” performs operations with minimal invasion, utilizing small incisions instead of a single large one. This technique requires specialized tools and a way for the surgeon to see and maneuver inside the abdominal or pelvic cavity. Gas is an indispensable part of this procedure, providing the necessary conditions for a safe and effective operation.
Creating the Working Space
The abdominal cavity is naturally a collapsed space where organs rest against each other and the abdominal wall. For the surgeon to insert instruments and visualize the operative field, this space must be artificially expanded and stabilized. This expansion is achieved through a process called insufflation, which involves pumping gas into the cavity.
This controlled inflation creates a dome-like shape, physically lifting the abdominal wall away from the internal organs. The resulting space is called a pneumoperitoneum, and it is maintained at a specific intra-abdominal pressure, typically between 12 and 15 mmHg, using a specialized device called an insufflator. This pressurized environment provides a clear, three-dimensional view of the organs through the laparoscope, a thin instrument with a camera and light.
The mechanical separation of the tissues is crucial because it allows the surgeon to safely introduce and manipulate long, slender surgical tools. Without this inflated space, the risk of accidental injury to surrounding organs would be significantly increased, making the procedure impossible to perform effectively.
Why Carbon Dioxide is Chosen
The gas used for insufflation is almost universally Carbon Dioxide (CO2), chosen for a combination of scientific and practical reasons. A primary consideration is safety, as CO2 is non-flammable and does not support combustion. This is important because surgeons frequently use electrocautery tools, which generate heat and electrical currents, to stop bleeding and cut tissue during the operation.
Carbon Dioxide is the gas of choice because of its high solubility in blood, being about 22 times more soluble than oxygen. This means that if any gas accidentally enters the bloodstream, it dissolves and is quickly absorbed by the body. This rapid absorption significantly minimizes the risk of a gas embolism, a potentially serious complication where a gas bubble blocks a blood vessel.
Furthermore, CO2 is naturally present in the body as a byproduct of metabolism. The body possesses a highly efficient system for processing and eliminating excess CO2 through the lungs, making it physiologically compatible with the patient. This compatibility makes CO2 the preferred and safest medium for creating the necessary working space.
What Happens to the Gas After Surgery
Once the surgical procedure is complete, the surgeon actively releases the majority of the carbon dioxide gas from the abdominal cavity. Most of the gas is vented through the small incisions before they are closed, often with gentle pressure applied to the abdomen to encourage expulsion. However, a small amount of residual gas inevitably remains trapped inside the body.
This remaining CO2 is safely absorbed into the bloodstream from the peritoneal tissues. The circulatory system then transports this dissolved gas to the lungs, where it is naturally expelled through the patient’s normal breathing. This process of absorption and exhalation usually resolves the retained gas within a few hours to days after the operation.
Occasionally, the residual gas can irritate the diaphragm. This irritation can cause a phenomenon known as referred pain, which patients commonly feel in the shoulder or upper chest area. This discomfort typically resolves on its own as the body eliminates the final traces of CO2.