A funnel chest (technical term: pectus excavatum) refers to a funnel-shaped depression of the sternum and is the most common type of chest wall deformity. It occurs in 1:300-400 people, more frequently in boys and a familial clustering has been observed. The funnel chest can already exist after birth, or develop or worsen during puberty as the child grows in length. The deformity is caused by excessive growth of the cartilage connections between the breastbone and the ribs, the exact cause of which is still unclear. There are various forms of funnel chest, the depth and length of the "funnel" varies from patient to patient and it can be symmetrical or asymmetrical.

 

Restrictions due to a funnel chest

As a rule, adolescent funnel chest patients have no limitations to their physical performance. A relevant factor for those affected is usually a pronounced emotional burden due to dissatisfaction with the appearance of the anterior chest. As a result, many sufferers are restricted in their social life, they avoid going to the swimming pool or are teased by classmates. This can result in a significant reduction in quality of life. There are now numerous studies on this aspect, in which this has been scientifically proven [1].

However, physical limitations are also increasingly observed in adulthood, e.g. during exercise. This can, for example, be due to a slightly reduced cardiac output during exercise, as the sunken sternum compresses the right atrium of the heart [2; 3]. In addition, a reduced lung volume is measured in some patients, as the lungs do not have as much space available due to the narrow chest. However, this often only plays a minor clinical role due to sufficient lung reserves.

In most cases, a funnel chest in adolescence is a harmless clinical finding that does not require surgery. However, if the affected person suffers from the appearance of their chest, the funnel chest can be corrected. There are various methods for this, which are explained below.

 

1) Minimally inv asive pectus excavatumcorrection according to Nuss: The minimally invasive repair of pectus excavatum (MIRPE) is now considered the gold standard in the surgical correction of pectus excavatum and is the most widely used surgical method. It was first performed in 1987 by Dr. Donald Nuss and a series of 42 patients was first published in 1998 [4]. The principle consists of a specially adapted metal stirrup that is placed under the sternum and lifts the sternum, immediately correcting the funnel chest. This stirrup remains in place for approx. 3 years if the patient's condition progresses normally and can then be surgically removed in a short procedure under anesthesia. Nowadays, this method is regularly performed worldwide and new modifications are constantly being developed [5 - 10].

Ideal age for correction: The ideal time for surgery is shortly before or after the end of longitudinal growth, i.e. between the ages of 13 and 20. At this time, the shape of the rib cage is largely as pronounced as can be expected in the end.

In Germany, funnel chest surgery is only carried out at an earlier age in absolutely exceptional cases of severe complications caused by the funnel chest. Over the years of the development of minimally invasive funnel chest correction, various studies have repeatedly reported recurrences if the operation was performed too early [11; 12]. The funnel chest therefore recurred and the patients had to be operated on again.

In the vast majority of cases, funnel chest does not cause any physical complaints during childhood and puberty. During puberty, however, social life is often restricted due to dissatisfaction with the appearance of the ribcage. Many patients avoid going to the swimming pool or are teased by classmates. Correction can usually counteract this development and patients feel comfortable in their bodies again [1].

Other studies also show that uncorrected funnel chests can lead to restrictions in cardiovascular function, which normalize again after funnel chest correction [13].

Necessary examinations before the operation: The following examinations should be carried out on an outpatient basis before the operation and the findings should be brought to the inpatient admission: X-ray thorax in 2 planes (funnel chest findings see Figure 1a), sitting echocardiography (ultrasound of the heart), ECG, pulmonary function test. A CT (computed tomography) of the chest is not normally necessary! It has a high radiation exposure and usually does not provide any relevant information that would influence the operation. In our Clinical Department, however, we have the possibility to measure and visualize the chest without radiation using a 3D scanner.

The examinations are primarily used to diagnose and document functional limitations in the patient's lung and heart function and to visualize the extent of the funnel chest in the imaging.

Surgical procedure: A small incision is made on each side of the chest. A metal stirrup that is individually adapted to the chest is inserted under the sunken sternum under visual control with the aid of a thoracoscopy. This is corrected forwards by the stirrup and held in a normal position (see Figures 2a and 2b). The stirrup is then fixed laterally (usually using one or two stabilizers) to the intercostal muscles (see Figures 3 & 4).

An important advantage of this method is that it is not necessary to operate on the bones and cartilage themselves, in contrast to the open surgical method using the Ravitch technique, and that the small scars on the side of the rib cage are not visually disruptive.

 

Advantages of the minimally invasive method: This correction method is performed through only 2 small incisions and the entire course of the operation is monitored using a camera in the chest. Compared to open funnel chest correction according to Ravitch, the pain is less, the hospital stay is shorter and the recovery phase is faster [Nuss 1998]. The rib cartilage is not removed and better long-term results (particularly with regard to recurrence) have been described.

 

Number of corrective stirrups: As a rule, the implantation of one stirrup is sufficient for adolescent patients. In the case of very pronounced "funnels", 2 or, in rare cases, even 3 temples can be used. The older the patient gets and the firmer the rib cage becomes, the more sensible it may be to implant a second or possibly even a third stirrup, as enormous forces have to hold the rib cage in its new shape. In total, 2 stirrups are now used in around 40% of patients. This is not a disadvantage for the patient, but the aim of the operation is to achieve an optimal result, which in special cases can be achieved better and more safely with several stirrups.

 

Possible complications and risks of the operation: Complications can occur with any operation. Possible complications of minimally invasive funnel chest correction include dislocation (tilting) of the stirrup, infection, allergy to the metal of the stirrup, bleeding during the operation, injury to surrounding tissue (including the heart, pericardium, lungs, diaphragm) and failure to achieve the desired correction result.

Even though we have been regularly performing minimally invasive funnel chest corrections without major complications since 2000, this operation remains a potentially risky procedure. Serious complications and even deaths have been reported internationally and nationally [14]. Important factors for performing the operation safely are the center's experience with minimally invasive thoracic surgery and good visual control by means of thoracoscopy during the operation in order to place the stirrup safely. Furthermore, good cooperation with the experienced Departments of Anesthesia and Pediatric Intensive Care Medicine is required.

It is also important to know that cardiopulmonary resuscitation (heart pressure massage) may not be possible as long as the stirrup is in the body.

Post-operative course: Immediately after the operation, the focus of inpatient treatment is on good pain therapy and the start of mobilization. Depending on the course of the operation, the entire inpatient stay will last around 5-7 days.

Sports should be avoided for 6 - 8 weeks and no contact sports should be practiced for 3 months. During this period, care should also be taken to avoid jerky rotational movements of the upper body. After that, there are no more restrictions.

Most patients no longer notice the brace after a few weeks.

A follow-up check in the consultation should take place after 6 months. However, if problems occur, we should be contacted immediately for further diagnostics.

 

Post-operative pain therapy: Immediately after the operation, there is usually severe pain, which is why patients are given a pain pump through which they can administer opioid painkillers intravenously at certain intervals. Non-opioid painkillers are also administered at regular intervals. However, the pain usually decreases significantly after approx. 2-3 days and the need for painkillers can be gradually reduced. We are constantly adapting the treatment methods in collaboration with our pain team in order to further optimize pain therapy.

 

Metal removal: The brackets are usually removed under anesthesia after a period of 3 years. After this period, the rib cage has sufficiently stabilized in its new shape so that the removal of the stirrups usually no longer leads to a recurrence of the funnel chest. It is possible to leave the underwire in place for longer, but this is not necessary and can make metal removal more difficult. Staple removal should always be carried out for the reasons already mentioned, namely the limited resuscitation ability in the event of cardiovascular arrest and the additional improvement in lung function after metal removal, which has been proven in studies. Cardiac function is essentially improved by the initial funnel chest correction and is not further improved by metal removal.

The procedure is usually not very painful compared to the implantation of a stirrup, patients can usually be discharged after 2 days and are not restricted for long afterwards. Patients should nevertheless refrain from sport for 3 - 4 weeks.

 

Risk of recurrence after removal of the stir rup: In principle, recurrences can occur after metal removal, but after 3 years the chest has usually stabilized to such an extent that it retains its "new" shape even after removal of the stirrup.

However, should a recurrence occur in the course of the procedure, we recommend contacting us again to discuss the possible treatment options.

 

2) Ravitch open correction method: Dr. Mark Ravitch developed a surgical method for correcting a funnel chest back in 1949 [15]. The deformed rib cartilage is removed via a large skin incision in the anterior chest area (often centrally above the sternum, in some cases also transversely below the chest), the sternum is cut with a saw and brought into the desired shape. In the meantime, this correction method is also followed by the insertion of metal brackets for stabilization for some time [16].

As minimally invasive funnel chest correction according to Nuss (see above) has clear advantages over this surgical method and is the gold standard, we only perform open funnel chest correction at our Clinical Department in exceptional cases.

 

3) Suctioncup therapy according to Klobe: In 2005, Eckart Klobe (engineer and patient himself) and Prof. Felix Schier developed suction cup therapy as an alternative to surgical therapy [17]. The suction cup is placed on the chest from the outside and creates a vacuum. This leads to an elevation of the sternum and must be applied very regularly. It is recommended that it is used 2-3 times a day for 20-30 minutes over a period of approx. 18-24 months. It is generally used for less pronounced findings. Consistent application can lead to a permanent reduction in the depth of the funnel in some patients [18]. Problems with this form of therapy are skin irritation and the relatively low effectiveness as well as the long duration of therapy.

Most patients who present to our Clinical Department have pronounced findings for which this therapy method is not suitable.

 

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