Left Isomerism Sonographic Findings and Post Mortal Autopsy in a Female Foetus

Case Report

Austin J Anat. 2015; 2(3): 1043.

Left Isomerism Sonographic Findings and Post Mortal Autopsy in a Female Foetus

Fröber R¹, Eichhorn K², Schleußner E³ and Schlembach D³*

¹Departmente of Anatomy, Jena University Hospital, Germany

²Center for Prenatal Diagnosis, Gerhart-Hauptmann- Strasse, Germany

³Department of Obstetrics, University of Jena Hospital, Germany

*Corresponding author: Schlembach D, Department of Obstetrics & Gynecology, Prenatal Diagnosis & Fetal Physiology, University of Jena Hospital, Bachstrasse 18, 07743 Jena, Germany

Received: November 25, 2015; Accepted: December 10, 2015; Published: December 16, 2015


Background: Left isomerism is a complex malformation syndrome. Important diagnostic pointers like viscera cardiac heterotaxy, complex cardiac anomalies, heart block and interruption of the inferior vena cava provide the prenatal diagnosis. However, although essential for counseling about prognosis, the knowledge about the whole spectrum of associated anomalies in cases of left isomerism is very rare.

Case Presentation: We report a case of a 26-year-old primigravid women presenting at 17+3 weeks of gestation with foetal left isomerism. Following termination of the pregnancy a detailed teratological examination according to the guidelines of the sequential segmental approach was performed, which confirmed the prenatal sonographic findings. Moreover, additional distinct malformations of the cardiovascular, the pulmonal and the gastrointestinal tract were revealed. The main malformation features were: uniatrial-univentricular connection between the left isomeric atrium and a double-outlet right ventricle, interruption of the inferior vena cava combined with juxtaposition of its subhepatic portion and the abdominal aorta, polysplenia, and duodenojejunal malposition with subsequent malrotation of the malfixed bowel.

Conclusion: We demonstrate the importance of an interdisciplinary cooperation of highly skilled sonographer and pathoanatomical experts in teratology. An accurate prenatal diagnosis of left isomerism is feasible. However, the whole dimension of this complex malformation syndrome is usually prenatal not visible. Detailed post mortal autopsy should be recommended to enhance the prenatal diagnosis further with respect to adequate counseling of the parents.

Keywords: Left isomerism; Heterotaxy; Congenital heart disease; Polysplenia; Echocardiography; Autopsy


Heterotaxy syndrome is a rare disease with an incidence of 1-1.5/10,000 live births and high mortality rates [1-3]. This malformation syndrome is defined as the abnormal arrangement of viscera across the left-right axis primarily induced by disorders of the laterality determination during early embryonic development. Its cellular and molecular mechanisms have been extensively investigated in the past decade and the developmental mechanisms of the syndrome have been considerably elucidated [2]. According to the characteristic morphology of the atrial appendages heterotaxy can be divided into “bilateral right-sided” (right isomerism) and “bilateral left-sided” (left isomerism) [4]. Typical findings in case of left isomerism are viscera cardiac heterotaxy, complex cardiac malformations, heart block, and interruption of the inferior vena cava [5]. However, a wide variety of cardiac and extracardiac congenital malformations, with considerable overlap of the anatomical features can occur. In consequence the prenatal differentiation between the two main settings is sometimes delicate. However, it is possible by assessment of specific diagnostic pointers. An intimate knowledge of these markers and the corresponding real anatomy is essential for an exact diagnosis, which is mandatory for adequate parental counseling for planning pregnancy and postnatal management, further diagnostic steps, and also further pregnancies [6]. In this case we report a case of prenatally diagnosed left isomerism illustrated by detailed anatomical pictures.

Case Presentation

Clinical findings

A healthy 26-year-old primigravid woman was referred at 17 + 3 weeks of gestation to a specialist sonographer (K.E.). Ultrasound examination revealed a severe congenital heart defect; brady arrhythmia and heterotaxy syndrome (left isomerism). The sonographic findings are summarized in (Table 1) and (Figure 1). Chromosomal analysis revealed a normal karyotype (46, XX). After detailed counseling, the parents opted for termination of pregnancy at 20 weeks of gestation. Following termination of pregnancy a detailed teratologic examination was performed. The foetal heart has been examined following the guidelines of the sequential segmental analysis [7].