Minimally Invasive Correction of the Funnel Chest

Univ.-Prof. Dr Michael Rolf Müller

Prof. Müller, funnel chest - a deformity of the front chest - is a congenital disease. How often does it occur and what causes it?

The exact causes are unclear, but disorders of cartilage growth around the sternum are suspected to be the most common. Males are affected much more frequently, the frequency in the general population is around 4/1000. The deformation of the costal cartilage radiating into the sternum leads to a malposition of the spine and the formation of a rounded back, which is significantly increased by the reluctance to present oneself with a bare upper body. The shoulders are hunched forward, the back is arched and the abdominal muscles are slack as a result.

In which cases does an operation make sense and at what age should it be performed?

In the absence of relevant physical symptoms, the end of growth should be awaited before surgical measures are taken. However, in very severe forms with detectable physical symptoms caused by the displacement of the chest organs, surgical correction of the funnel chest may be necessary in order to avoid developmental disorders.

How is minimally invasive surgery to correct pectus excavation performed and what are the advantages over other surgical methods?

In order to plan an operation that may be necessary, medical findings are discussed together in a detailed personal consultation: chest measurement, lung function test, cardiac echography and ECG.

However, the accompanying psychological and cosmetic stress for those affected should not be underestimated, so that an operative correction sometimes has to be considered even without measurable functional limitations.

The aim of the operation is the best possible correction of the funnel chest while avoiding large, annoying scars. Today, therefore, minimally invasive methods are used almost exclusively, the results of which are anatomically and functionally comparable to those after open surgery, but produce significantly better cosmetic results due to the smaller incisions.

Donald Nuss, a pediatric surgeon in the United States, developed a less invasive method of correction in 1987. The method was originally used in young patients up to 19 years of age with symmetrical and less pronounced chest excavation. An individually adapted steel bar is inserted under camera view behind the sternum at the level of the deepest depression and thus the sternum is lifted from the inside to the outside.

The method according to Nuss is also used today on adults with correspondingly less elastic conditions and, in my own experience, is even used successfully with strongly asymmetrical forms. In growing patients, the bar has to be replaced by a larger one about every 2 years. In adults, if it is in the correct position and there are no symptoms, the bar remains in the chest for about 3 - 4 years to prevent the breastbone from sinking.

How long is the hospital stay after the operation and what should be considered afterwards?

Despite the minimally invasive technique, the classic Nuss metal bracket and the fixation of the side ends of the bracket on the ribs caused aching pain. I have therefore been using a modification of the Nuss method for many years, recommended by Prof Pilegaard, who recommends shorter bars that are only stabilized on one side. This avoids the "clamping effect" of the bracket and the chest can move normally even when breathing deeply. As a result, the pain level is incomparably lower.

How are the risks and prospects of success of this operation to be assessed?

The operation directly between the heart and the sternum involves a risk of injury. In fact, however, the complication rate in the hands of the experienced surgeon is extremely low due to the optical control with the video camera. The success of the procedure is already visible immediately after the operation and usually gets even better over the following months and years.

How long after the operation can pain be expected and how long does it take for the sternum to come into its normal position.

The pain caused by using the classic method according to Nuss with a long bar and stabilization plates on both sides has completely disappeared with the new method. Patients can leave the hospital on the third day with mild pain medication and report symptoms similar to those observed elsewhere, for example when wearing new orthodontics. The sternum is usually in the desired position early after surgery, depending on the elasticity of the thorax, with the thorax continuing to adjust over the months and years that follow.