Situs Inversus

Congenital condition caused by malrotation of viscera in utero. Can be classified further into situs inversus with dextrocardia or situs inversus with levocardia. The classification is independent of the cardiac apical position. The association of situs inversus and ciliary dyskinesia is known as the Kartagener syndrome.

Present in 0.01% of the population. Patients present a normal life expectancy. In the rare instance of cardiac anomalies, the life expectancy is determined by the heart condition and not the presence of a situs inversus. The male:female ratio is 1:1.

Autosomal recessive inheritance and congenital anomalies.

Unknown. Abnormal rotation of the viscera in utero results in the orientation of the lungs and abdominal organs being reversed. Dextrocardia may or may not be present. The occurrence of situs inversus viscerum with levocardia is associated with severe congenital heart disease.

Radiological and echographic demonstration of abnormal orientation of organs with or without dextrocardia.

Situs inversus may remain asymptomatic throughout life, with little impact on cardiorespiratory function. Situs inversus is a feature of Kartagener syndrome, asplenia syndrome, and polysplenia syndrome. Clinical features of these medical conditions may therefore be present. Congenital heart disease described with situs inversus includes ventricular septal defect, atrial septal defect, transposition of the great arteries, and conotruncal malformations.

Examine for features of Kartagener syndrome (increased risk of pneumonia and perioperative respiratory embarrassment). Consider chest radiograph. Full cardiac evaluation, including history, examination, ECG, and echocardiography if congenital heart disease is present. Cardiac catheter data as indicated clinically.

Anesthetic technique dictated by presence or absence of cardiac disease. If part of Kartagener syndrome, a technique to maximize ability to clear secretions and early use of physiotherapy postoperatively should be considered.

There are no known specific implications with this condition.

Situs Ambiguous: When the situs orientation cannot be determined, the patient has situs ambiguous or heterotaxy. The liver may be midline, the spleen absent or multiple, the axial morphology unclear, and the bowel malrotated. Two primary subtypes include: right isomerism or asplenia syndrome, and left isomerism or polysplenia syndrome.

Kartagener Syndrome: The association of situs inversus and ciliary dyskinesia is known as the Kartagener syndrome. Genetically transmitted polymalformative syndrome characterized by bronchiectasis, situs inversus, and chronic sinusitis. Twenty percent of patients with situs inversus are affected with Kartagener syndrome.