How a vacuum bell corrects pectus excavatum.
Pectus excavatum is a cartilage problem, and cartilage can be reshaped without surgery. A vacuum bell lifts the breastbone the moment it seals, surgeons have watched it happen with a camera inside the chest, and daily use teaches the cartilage to hold the new position. Here is the science.
- The breastbone sits below the line of the ribs.
- Under the bell, it rises into position in one session.
- Off the bell, muscle pulls it back down.
- Held between sessions and retrained, the cartilage learns the position over months.
The dent is in the cartilage.
Your breastbone is joined to the ribs by the costal cartilages, flexible bars of hyaline cartilage. Most explanations of pectus excavatum point to these cartilages: shaped wrong, they hold the breastbone back behind the line of the ribs. That is good news, because cartilage is far more pliable than bone. It bends under load, and under a load that keeps coming back, it reshapes.
The video shows four steps. Step 1, seat the bell on the chest. Step 2, pump. Step 3, the breastbone lifts to the rib line, shown as an illustration. Step 4, lift the bell off. At the end the chest sits level, with a red ring where the bell sealed.
The physics of the bell.
The hand pump draws air out of the silicone dome. The air around you keeps pressing on the rest of your body, so the chest wall inside the rim is pulled up into the dome. Clinical protocols lower the pressure inside the dome by up to 15% below the air around you, which is about 150 grams of pull on every square centimetre inside the rim. The pull is even across the dome, and the chest moves most where it gives most: the sunken cartilage and the breastbone it holds.
Sources: Haecker FM, Mayr J, 2006; Schier F, Bahr M, Klobe E, 2005.
Surgeons use it too.
In Basel, the surgical team places a vacuum bell on the chest during the Nuss operation itself. Across 50 operations, a camera inside the chest confirmed a clear lift of the breastbone, which made room to pass the bar, and the team recommends it as routine. Other teams have shown the same lift on CT scans. The bell was invented by an engineer who had pectus himself and corrected his own chest with it.
Sources: Haecker FM, Sesia SB, 2012; Haecker FM, Sesia S, 2016; Togoro et al., 2018.
How the new shape sets.
Cartilage is viscoelastic. Held under a steady load, it keeps yielding for minutes (creep), and the internal stress pulling it back eases (stress relaxation). Its cells sense mechanical load, and repeated day after day, that load drives the cartilage to remodel toward the new position over months: the same principle that moves teeth under braces and reshapes a protruding chest in a brace. Between sessions, the diaphragm and a thin muscle behind the breastbone, the transversus thoracis, pull it back in, which is why the method holds the position with a brace and retrains those muscles.
Source for the muscles: the Klobe vacuum bell user manual.
Consistency is what corrects it.
In a study of 240 children whose chests still moved, the average dent shrank by nearly two-thirds, from 0.83 to 0.30 inches, and the researchers named adherence as a key factor in the result. FormaChest’s founder showed the same on himself: the routine every day, without exception, took his chest from a one-inch dent to nearly flat in four and a half months.
Source: AlShammari et al., J Thorac Cardiovasc Surg 2025.
Built to make every day easy.
A bare bell leaves you on your own for the other 23 hours. The FormaChest method fills that gap.
The brace.
Holds the lift between sessions.
The exercise.
A short routine from the guide that retrains the muscles pulling inward.
The right size.
A bell that seals on the firm rim of your chest, checked by a person before it ships.
What a day looks like.
About an hour in total, most of it on the couch.
-
Morning30 minutes under the bell, on the couch or in bed.
-
During the dayThe brace holds the position under your shirt.
-
A few times a dayShort rounds of the exercise, wherever you are.
-
Evening30 minutes under the bell, then the gel on your skin.
Before it ships, a person confirms your size. After it arrives, you get a Day-1 walkthrough, a plan for your case and a check-in every two to three weeks. Tomas answers every time.
What the research says.
improved significantly in the Basel study.
kept going when someone checked on them.
average dent before and after, 240 children.
patients studied, across 27 studies.
Each dot is 10 patients.
Twenty years of clinical use, and offered at major children’s hospitals.
Sources: Basel cohort, about 140 patients; Haje et al., 2021; AlShammari et al., 2025; Sesia et al., 2025.
Before a bar goes behind the breastbone.
The Nuss procedure threads a curved steel bar behind the breastbone, leaves it there for two to three years and takes it out in a second operation, at $40,000 to $80,000. The bell asks for none of that: nothing enters the body, you control the pressure at home, and you can stop any day. If your chest still moves, you can find out in 60 seconds, before you sign anything.
Is it right for you?
If your chest still moves, a mild to moderate dent that lifts under suction, the bell is for you. Age changes how long it takes, not whether it works: the oldest patient in the Basel series was 61. The 60-second quiz checks this for you and gives you your size.
Deep, rigid dents and any breathing or heart symptoms need a doctor first. Under 18, a parent decides.
Real results.
Verified buyers now post their own photos, and the founder's chest went from a one-inch dent to nearly flat in four and a half months, where published cohorts take 12 to 24, measured every morning before the session.
Sources.
Show all 11 sources
- Schier F, Bahr M, Klobe E. The vacuum chest wall lifter. J Pediatr Surg. 2005;40:496 to 500.
- Haecker FM, Mayr J. The vacuum bell for treatment of pectus excavatum: an alternative to surgical correction? 2006.
- Haecker FM, Sesia SB. Intraoperative use of the vacuum bell for elevating the sternum during the Nuss procedure. J Laparoendosc Adv Surg Tech A. 2012;22:934 to 936.
- Haecker FM, Sesia S. Vacuum bell therapy. Ann Cardiothorac Surg. 2016;5(5):440 to 449.
- Togoro SY, Tedde ML, Eisinger RS, et al. The Vacuum Bell device as a sternal lifter: an immediate effect even with a short time use. J Pediatr Surg. 2018;53:406 to 410.
- Haecker FM. 20 years clinical application of the vacuum bell. J Thorac Dis. 2024.
- AlShammari A, Santhirakumaran G, Patel A, Hunt I. Prospective evaluation and successful outcomes using vacuum bell therapy for pectus excavatum in selected pediatric patients: analysis of a prospective cohort study of 240 patients. J Thorac Cardiovasc Surg. 2026;171(3):732 to 741 (online November 2025).
- Sesia et al. A scoping review of the effectiveness, appropriateness and economic efficiency of the vacuum bell for pectus excavatum within the Swiss healthcare system: 27 studies, 2,271 patients. J Thorac Dis. 2025 (online 29 October 2025).
- Haje DP, et al. Localized pectus excavatum treated with brace and exercise. Acta Ortop Bras. 2021;29(3):148 to 153.
- Klobe E. Vacuum bell user manual (manufacturer’s instructions), quoted above.
- Cincinnati Children’s Hospital Medical Center, vacuum bell therapy, institutional adoption.
Read the full scientific breakdown.
The routine, the pressure, the exercise that turns the muscles around, and how to track it, in the free guide.