Right-Sided Aortic Arch, Kommerell Diverticulum withAberrant Left Subclavian Artery: Diagnosed byPrenatal Ultrasound andPostnatalCardiovascular Casting
Jiaqi Zhang, MD* , Yu Wang, MD*, , Wei Feng, MD* , Ziyi Si, MD, Jinzhi Xu, MD, He Zeng, MD, Qiaoyue He, MD, Ya Liu, MD
Department of Ultrasound, Xiangyang No.1 People’s Hospital, Hubei University of Medicine
* Drs Zhang, Wang and Feng contributed equally to this work
Correspondence to: Dr Yu Wang, Department of Ultrasound, Xiangyang No.1 People’s Hospital, Hubei University of Medicine, No 15, Jiefang Avenue, Xiangyang, Hubei, 441000, China, e-mail: 287383672@qq.com.
CONFLICT OF INTERESTS: The authors declare no conflict of interests.
KEY WORDS: Kommerell diverticulum, aberrant left subclavian artery, fetal echocardiography, cardiovascular casting
Funding information :
This work was supported by Science and Technology Research Project of Education Department of Hubei Province (B2019112).
Abstract : Kommerell diverticulum (KD) is a rare cardiovascular malformation, which is usually diagnosed after birth. To our knowledge, there is no report of prenatal diagnosis of KD so far. Here we present a case of RAA, KD with ALSA prenatally. We confirmed the prenatal diagnosis with a new modified cardiovascular casting technique, which perfectly demonstrated the cardiovascular malformations of the fetus. Our case demonstrates that the modified cardiovascular casting technique can distinctly delineated correlations and spatial structure of heart and cardiac vessels, and this new approach of casting combined with clinical diagnosis may have a role in postnatal diagnosis and clinical teaching.
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A 31-year- old primigravida was referred to our maternal–fetal medical center at a gestational week of 23+3 weeks for suspected heart defects. The cell-free fetal DNA test suggested a low risk of aneuploidy. Prenatal echocardiography revealed RAA with right descending aorta (RDA), left posterior ductus arteriosus (LPDA), forming a “U-shaped” vascular ring. ALSA originating from Kommerell diverticulum (KD) was also seen (Figure 1, A, B). 3D HD-Flow and glass body confirmed the “U-shaped” vascular ring and enlarged KD (Figure 1, C, D). Left ventricular outflow tract section showed a VSD with the aortic riding across ventricular septum (Figure 2). The fetus died in the uterus due to umbilical cord knot at the gestational age of 26 +4 weeks. The induction gave a male fetus with a weight of 724 g. The family voluntary donation of specimen to our maternal and fetal medical center and a written informed consent for this study was provided. The fetal specimen was later made into a cardiovascular cast by following five specific steps. First, the abdominal wall was incised. The umbilical vein was separated and intubated with a small tube. The umbilical arteries were separated with the left side cut off. Heparin (5–10 mL) and acetone (30–60 mL) were injected successively via the umbilical vein to flush out residual blood clots in the cardiovascular system. Second, the specimen was perfused with butadiene-styrene plastic (ABS) gel (30–60 mL) at appropriate pressure and constant speed for approximately 10 h. Third, after 24 hours, the ABS gel-filled specimen was soaked in 30% hydrochloric acid. Fourth, after 2 weeks, the specimen was removed carefully from hydrochloric acid and rinsed thoroughly until there was no residual tissue adhesion on the cardiovascular cast. Finally, the fetal cardiovascular cast was marked, displayed and assessed. The subsequent anatomy and cardiovascular cast confirmed the prenatal diagnosis (Figure 3, Figure 4).
Kommerell diverticulum is a rare vascular malformation characterized by bulbous configuration of the origin of an aberrant left subclavian artery in the setting of a RAA. It is usually detected by accident in asymptomatic patient and rarely diagnosed prenatally. The reported prevalence of KD is 0.05% of the population.1 KD with right aortic arch is a rare congenital anatomical anomaly whose clinical course has not been fully determined. Complications may occur depending on the anatomical distribution of the local structures, the size and extent of the aneurysm. Greater fragility this vascular alteration and more extensive lesions are associated with occurrence with more adverse consequences such as dissections, thromboses and ruptures.2Echocardiography is the preferred method for diagnosing KD, it can be used not only as an imaging method for diagnosis, but also as an imaging method for outpatient follow-up. Moreover, it is safe, convenient and inexpensive.3 Cast models can visually display the origin, course, dimension and relative spatial position of the great vessels, and may become an important supplement to prenatal echocardiography.4 In our case, echocardiography and cardiovascular casting have a complementary relationship and provide a comprehensively evaluation of inside and outside of heart, which is of great importance in diagnosing and teaching of complex fetal cardiac malformations.