A vacuum bell consists of medical equipment placed upon the chest for pectus excavatum treatment. Pectus excavatum is where the chest becomes concave in appearance due to sinking inward, which is also described as a “funnel chest.” Applying a vacuum bell causes the chest to be sucked outward, raising the chest wall and reducing the concavity in the middle of the chest.
The bell works by attaching a suction cup to the chest and using a hand pump to excavate air out of the interior of the bell. Different sizes of suction cups are used for different ages and chest sizes, although the average size usually varies from 6.3 to 7.87 inches (16 to 26 cm). The patient operates the hand pump to pump out enough air from the bell to create a vacuum, which can be as great as 15 percent below the atmospheric level of 14.696 psi, or about 12.49 psi.
Chest wall defects have been described since the time of Hippocrates, who noted a bony projection in the middle of the chest that resembled a chicken breast and caused difficulty breathing. A concave deformity of the chest was also described in 1954 by Johannes Schenk and is now known to be a common defect of the chest wall, affecting about five times as many males as females. Chest wall defects were first reported as being treated by using a vacuum bell in Munich, Germany in 1910, as part of nonsurgical medical treatments for lifting the chest wall away from the breastbone.
Pediatricians have documented some degree of chest defect in approximately 85 percent of newborns. Many of the more severe types were corrected by chest surgery since the Ravitch procedure was developed in 1952. In the 1990s, when the Nuss procedure was developed to treat this condition, a vacuum bell was frequently used with other medical devices to help pull the sternum, or chest bone, away from the heart during the procedure.
The use of the vacuum bell to treat chest defects has been compared to orthodontic treatment, which can take up to two years to produce lasting results. Immediate effects can be noticed after applying the bell, such as in clinical studies, where the sternum and ribs are raised up immediately after the bell is applied. Regrowth of chest cartilage in new formations can take up to two or three years to achieve, however.
The bell is most effective for less severe chest defects. It has been found to produce good results for many individuals when used for a minimum of 30 minutes at a time at least twice a day, with an ideal use of about 1.5 hours daily. When used clinically, many persons have shown considerable lasting improvement in their chest structure after five to nine months.
The vacuum bell is popular in Europe, where it can be purchased from the Internet. Persons who have used the bell in health clinics have expressed their satisfaction and promised to continue using it as long as it was needed. Some pain and reddened skin were reported when first using the bell, due to the strong suction it can produce. The pain was not severe, however, and it was reduced with continued use. The amount of suction can also be controlled by the person using the device.
The device is not recommended for use on young children, due to their more fragile chest bones and cartilage. Adolescents generally like using the bell, as well as many adults. The ages of those who use the apparatus range from around 10 to 50.