A veress needle is a surgical instrument also called an insufflation or pneumo needle. It is a spring-loaded needle used in many laparoscopic operations to inflate the abdominal cavity before a trochar tool is inserted. This type of needle is made in two different sizes, featuring a spring-loaded blunt tip that retracts into a sharp outer needle as it is inserted into the abdominal cavity. Once the peritoneal cavity is reached, the blunt tip emerges and carbon dioxide is added to the abdominal cavity allowing the laparoscopic procedure to begin.
Incorrect positioning of this needle can cause severe injuries. Damage to the nearby blood vessels or to the intestines is possible if the instrument is not inserted at the proper angle. Puncturing the bowel may cause a post-operative infection called peritonitis. Insertion into a blood vessel can cause excessive bleeding or cause air pockets to form within the vessel. The right common iliac artery, the inferior epigastric vessels, and the distal aorta are most often damaged if the veress needle is not correctly used.
Proper use of the veress needle involves the careful positioning of the patient at the beginning of the laparoscopic procedure. Before the surgeon inserts the veress needle, the patient will be placed in the trendelenburg position. The abdomen is elevated and the patient is immobilized prior to the introduction of the veress needle towards the pelvic region at a 45-degree angle to the spine. If the needle deviates from the anticipated insertion angle or is inserted perpendicular to the abdomen, serious injury can occur.
A surgeon can verify the proper positioning of the veress needle by performing a few simple tests. First, saline is added through the needle. When it is properly positioned, the surgeon will be unable to aspirate any fluid from the needle. If blood is drawn up from the needle, it may indicate that it has punctured a blood vessel. Fecal matter or urine may also be aspirated from an incorrectly positioned veress needle.
After the surgeon is reasonably certain the needle is placed in the proper location, a valve will be attached to the instrument. Carbon dioxide is slowly pumped into the abdominal cavity to inflate the region for optimum visibility during the surgical procedure. Then the surgeon will perform another test to ensure the needle is correctly placed. During this test, the valve supplying the carbon dioxide is briefly closed, causing air to escape from the veress needle with a slight hissing sound. If no hissing sound is heard, the needle may need be removed and repositioned.