Brustkorbdeformität

Dieser Artikel behandelt zwei der drei häufigsten Brustkorbdeformitäten: Pectus excavatum (Trichterbrust) und Pectus carinatum (Kielbrust). Die dritthäufigste Brustkorbdeformität wird durch Skoliose verursacht. Siehe den separaten Scoliosis and Kyphosis Artikel.

Pectus excavatum (funnel chest)

Es wird angenommen, dass dies durch eine Anomalie des Bindegewebes verursacht wird, die zu einer Einsenkung des Brustbeins führt. Es ist manchmal verbunden mit Marfan-Syndrom und Ehlers-Danlos-Syndrom. Most cases are recognised at birth or within the first two years of life.

Pectus excavatum

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Epidemiologie^{1 2}

Pectus excavatum is a congenital anomaly. It is the most common deformity of the anterior chest in children and is present in between 1 in 300-400 live births. There is a 4:1 male-to-female ratio. It is thought to be an inherited condition.

Untersuchungen³

• Radio-imaging with CXR is the first-line investigation.

• Two clinical methods have also been developed here in assessing the severity of pectus excavatum:⁴
  

  • Chest cytometry involves measuring the circumference of the chest in the region of the distal third of the sternum or at the site of greatest deformity with the patient in the orthostatic position and inspiring deeply.

  • Calculation of the anthropomorphic index - this involves taking two measurements. Firstly, the maximum anteroposterior measurement in the region of greatest deformity or of the distal third of the sternum (A) is assessed. Secondly, the greatest depth of the defect is measured with the highest point of the anterior costal wall and the lowest point of the pre-sternal region at the site of greatest deformity being used as reference (B). The index is calculated as B/A.

• Standardised cardiopulmonary function tests may be useful, particularly in assessing whether patients would benefit from surgery.

• CT chest scanning may be indicated to assess the degree of sternal deformity, the severity of lung compression and the presence of mediastinal displacement.

• An MRI technique has been developed due to concerns about the radiation dose obtained from CT scans.⁵

• Echocardiography may be clinically indicated in patients with dyspnoea to evaluate cardiac compression. 20-60% of patients have mitral valve prolapse. Atrial compression and cardiac displacement are frequently seen.

• Pulmonary function tests may be required to assess lung capacity.⁶

Behandlung³

• Mild cases may not require treatment, as the deformity can be hidden under clothing.

• The treatment to correct functional disability was for many years the Ravitch operation in which the anterior chest wall is exposed, skin and muscle flaps are created, the affected cartilages are excised and sternal osteotomy is performed.

• A newer minimally invasive procedure called the Nuss technique has been developed which involves the insertion of a retrosternal metal bar via two incisions, using a thorascope - this is now the standard treatment. The bar is removed 2-3 years later.^{7 2} Es wird hauptsächlich bei 12- bis 14-Jährigen angewendet, kann aber auch bei jüngeren Kindern und Erwachsenen durchgeführt werden, bei denen möglicherweise zwei Stäbe erforderlich sind.⁸ Die Technik könnte die Schwelle für chirurgische Eingriffe senken, die zuvor durch die hohe Inzidenz von Keloidbildung an der vorderen Brustwand, die das Ravitch-Verfahren erschwerte, behindert wurde. Es scheint wenig Unterschied zwischen dem Nuss-Verfahren und dem Ravitch-Verfahren in Bezug auf allgemeine Komplikationen, die Dauer des Krankenhausaufenthalts und die Zeit bis zur Mobilisierung zu geben. Allerdings könnte die Rate der Reoperationen, postoperativen Hämatothorax und Pneumothorax nach dem Nuss-Verfahren im Vergleich zum Ravitch-Verfahren höher sein.⁹

• Autologous fat transplantation has been reported, as has polyethylene implant for patients with mild deformity who required aesthetic improvement.^{10 11}

• A survey of patients who have had surgery showed considerable improvement in body image and function.¹²

• NHS England does not routinely fund surgery for pectus excavatum.¹³

Pectus carinatum (pigeon chest)¹⁴

In this condition, the sternum is raised (carina = keel). It used to be associated with rickets. Nowadays there is usually an associated history of severe asthma in childhood, sometimes with a ventricular septal defect (VSD). 20% of patients have an associated scoliosis. Pectus carinatum complicating surgical treatment for pectus excavatum has been reported.¹⁵

Pectus carinatum

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Two main types have been identified - chondrogladiolar (90%, keel chest, prominent middle and lower sternum) and chondromanubrial (pouter pigeon breast, prominent upper sternum). Some authorities also identify a lateral type.

The large forces needed for inspiration lead to an in-drawing of the lower portion of the ribs giving a Harrison's sulcus.

Most cases were thought to be asymptomatic. However, recent studies suggest that some patients develop a rigid chest wall resulting in reduced vital capacity and symptoms of dyspnoea, exertional tachypnoea and reduced endurance.

Epidemiologie¹

Dies ist viel weniger verbreitet als Pectus excavatum. Die Prävalenz in den USA wurde auf 0,06 % geschätzt, wobei ein Drittel der Patienten eine positive Familienanamnese aufweist. Assoziierte Krankheiten sind Marfan-Syndrom und angeborene Herzkrankheit. The patient or their parents will often be aware of the condition from early childhood but typically present to health professionals between the ages of 11-15.

Untersuchungen

• Pulmonary function tests should be performed if reduced lung capacity is suspected.

• Electrocardiography and echocardiography may be needed to rule out cardiac abnormalities and assess cardiac function.

• Chest radiography should be carried out; CT scanning may be helpful.

• A scoliosis series should be arranged if this condition is suspected.

Behandlung¹⁴

• Many patients have a mild deformity with no associated morbidity requiring treatment.

• Various physical methods of correcting the deformity have been tried, including casting, bracing and chest compressors.

• Endoscopic resection of costal cartilage and sternal osteotomy is available for patients who require cosmetic correction but this procedure does nothing to correct any functional disability.

• Rarely, if there is significant pulmonary and/or cardiac dysfunction, open surgical repair is performed. Various techniques have been tried.^{16 17}

• NHS England does not routinely fund surgery for pectus excavatum.¹³