The left-right asymmetry of liver lobation is generated by Pitx2c-mediated asymmetries in the hepatic diverticulum.

Internal organs exhibit left-right asymmetric sizes, shapes and anatomical positions, but how these different lateralities develop is poorly understood. Here we use the experimentally tractable Xenopus model to uncover the morphogenetic events that drive the left-right asymmetrical lobation of the liver. On the right side of the early hepatic diverticulum, endoderm cells become columnar and apically constricted, forming an expanded epithelial surface and, ultimately, an enlarged right liver lobe. In contrast, the cells on the left side become rounder, and rearrange into a compact, stratified architecture that produces a smaller left lobe. Side-specific gain- and loss-of-function studies reveal that asymmetric expression of the left-right determinant Pitx2c elicits distinct epithelial morphogenesis events in the left side of the diverticulum. Surprisingly, the cellular events induced by Pitx2c during liver development are opposite those induced in other digestive organs, suggesting divergent cellular mechanisms underlie the formation of different lateralities.

Congenital Abnormalities of the Pericardium.

Congenital abnormalities of the pericardium are a rare group of disorders that include congenital absence of the pericardium, pericardial cysts, and diverticula. These congenital defects result from alterations in the embryologic formation and structure of the pericardium. Although many cases are incidentally found, they can present as symptomatic, life-threatening disease. Owing to their rarity, many cases are inappropriately diagnosed. Alterations in the embryologic formation and structure may result in the formation of these congenital abnormalities. We review the presentation, diagnosis, and management of congenital absence of the pericardium, pericardial cysts, and diverticula. A summary of multimodality imaging features is provided.

Prenatal diagnosis of left ventricular diverticulum and coarctation of the aorta.

Congenital left ventricular diverticulum (LVD) is a rare abnormality of the myocardium which has been detected previously in the fetus. Lesions have been reported from as early as 12 weeks' gestation but are more commonly detected in the mid-second trimester. Fetal presentation of LVD ranges from an abnormal four-chamber view of the heart, arrhythmia or isolated pericardial effusion to fetal hydrops with associated heart failure. Here, we describe the prenatal diagnosis of an infant with LVD originating from the left ventricular outflow tract associated with coarctation of the aorta. The diagnosis was confirmed postnatally by two-dimensional echocardiography and cardiac magnetic resonance imaging. We hypothesize that the lesion compromised antegrade flow into the transverse aortic arch, which may have contributed to underdevelopment of the aortic arch and subsequently the development of coarctation of the aorta. This is a unique case of LVD and coarctation of the aorta.

Aberrant subclavian artery pathologies and Kommerell's diverticulum: a review and analysis of published endovascular/hybrid treatment options.

Aberrant subclavian artery (ASA) is one of the most common congenital vascular anomalies of the aortic arch. The incidences of aberrant right subclavian artery (ARSA) and aberrant left subclavian artery (ALSA) are 0.4% to 2.3% and 0.05%, respectively. Approximately 60% of ARSA patients will have a Kommerell's diverticulum at the origin of the ASA. Symptomatic or aneurysmal ASAs need to be treated. Historically, open operation was the favored method to reconstruct ASA anatomy; however, novel endovascular techniques are now available. Following a brief discussion of embryonic development, symptoms, and treatment history of the ASA and Kommerell's diverticulum, the results of a literature review to collect the worldwide experience of endovascular/hybrid treatment of ASA is presented.

Fetal right ventricular diverticulum with pericardial effusion: report of a new case treated by in utero pericardiocentesis.

Right ventricular diverticulum associated with pericardial effusion was diagnosed in a male fetus at 13 weeks of gestation. Screening for infectious, chromosomal, or structural disease was negative. Because there was concern about pulmonary hypoplasia, fetal pericardiocentesis was performed at 17 weeks of gestation. The pericardial fluid did not reaccumulate, and the diverticulum decreased and finally disappeared before the third trimester. The diverticulum could not be seen on the neonatal echocardiography scan performed on the full-term live baby, who was delivered vaginally. The child is doing well at 11 months of age. Given the good outcome of this case, in utero drainage should be considered in similar cases.

Prenatally diagnosed right ventricular outpouchings: a case series and review of the literature.

Congenital right ventricular aneurysms and right ventricular diverticula are rare forms of congenital heart disease for which little information exists regarding optimal management, natural history, or prognosis. With advancements in prenatal cardiac evaluation and ultrasound, the reported frequency of these lesions, as well as a better understanding of the natural history of this form of congenital heart disease, is likely to evolve. We present three cases of fetal right ventricular aneurysms/diverticula diagnosed at our institution, along with a review of the current literature. We describe the pre- and postnatal courses as well as suggest counseling and management strategies.

Prenatal rupture of a left ventricular diverticulum: a case report and review of the literature.

Congenital left ventricular diverticulum is a rare malformation. We report a case of a ruptured congenital left ventricular diverticulum in a 24-week-old fetus. The fetus was referred for a large and circumferential pericardial effusion confirmed by cross-sectional echocardiography in our tertiary fetal cardiology unit. Pericardiocentesis removed 25 mL of old hematic fluid. The fetus died 5 days later. The pathological examination showed a ruptured submitral fibrous diverticulum of the posterior wall of the left ventricle. There is no previous report in the literature of prenatal rupture of a cardiac diverticulum. The submitral location and the fibrous wall of the diverticulum is uncommon. As regards this case, we reviewed the diagnostic criteria and the outcome of 11 cases of prenatal cardiac diverticulum reported in the literature.

[Air-filled cysts of tracheal origin: nosological problems and actual frequency]. / Kystes aériens d'origine trachéale: problèmes nosologiques et fréquence réelle.

Air-filled paratracheal bronchogenic cysts are extremely rare. They are lined by respiratory epithelium. We have operated on 2 patients whose cysts were diagnosed by CT scan: one presenting with bloody sputum and the other with dysphagia. Both patients had a history of neck surgery. Because such cases are rare in the literature, their exact origin, whether tracheocele, diverticulum or other form of air-filled cyst, remains a matter of debate. However, their frequency is probably underestimated because most cause few symptoms and are well tolerated. In a recent radiologic study their prevalence was found to be 2% in patients undergoing CT scan.

[Pyelocalicial diverticula]. / Divertículos pielocaliciales.

OBJECTIVE: To review the embryological and clinical aspects of the different types of pyelocaliceal diverticula, with special reference to the differential diagnosis and treatment. METHODS: Images of type I and II pyelocaliceal diverticula are shown. The conditions that cause difficulty in making the differential diagnosis are discussed. RESULTS: Urography continues to be the diagnostic method preferred and is sometimes aided by retrograde ureteropyelography. CONCLUSIONS: Pyelocaliceal diverticula are cystic eventrations of the upper urinary tract lying within the renal parenchyma that communicate through a narrow channel into the main collecting system. They occur in 0.2 to 0.5% of the population and are congenital in origin. Calyceal diverticula are frequently found incidentally on routine excretory urograms, but patients may complain of flank pain, hematuria or recurrent urinary infections. In the past, treatment required open renal surgery. Endourologic procedures are widely utilized today.

Early prenatal diagnosis of ventricular diverticulum complicated by serous pericardial effusion.

An unusual case of apical diverticulum complicated by serous pericardial effusion and diagnosed ultrasonographically at 13 weeks of gestation is described. A therapeutic abortion was induced at 14 weeks and the complete post-mortem examination did not show additional malformation. Cardiac diverticulum is a rare malformation that occurs as an isolated defect or as part of a complex midline thoraco-abdominal defect. Only two prenatally diagnosed cases have been previously reported in the literature and none with associated hydropericardium.

[Pathology of developmental defects of the digestive system in human embryos]. / Patologicheskaia anatomiia porokov razvitiia pishchevaritel'noi sistemy u zarodyshei cheloveka.

Total incidence of the alimentary system defects was 1.05 +/- 0.12% in the non-selected material of medical abortions performed at 5-12 weeks of the intrauterine development. Atresia and stenosis of the duodenum are described for the first time in the embryos of the above age, the possibility of differential diagnosis between physiological and pathological atresia is established. The connection between the ducts of the ring-like head of pancreas and ductus choledochus is observed thus confirming the hypothesis of the additional pancreatic part developing from the ventral anlage. Diagnosis of Mekkel's diverticulum became possible beginning from stage 17. The existence of atresia, stenosis and gastro-intestinal tract doubling in the embryos of the above age indicate that at least some of these defects are not connected with a secondary damage of the intestinal tube due to circulation disturbances, recanalization or inflammation but represent a primary developmental anomaly arising in the early ontogenesis.

The aortic diverticulum: a remnant of the partially involuted dorsal aortic root.

The aortic diverticulum, a large bulge on the lesser curvature of the aortic isthums, is an occasional variation found during thoracic aortography in patients with a left aortic arch and normal origin of the brachiocephalic arteries. Although it is commonly thought to be a remnant of the closed ductus arteriosus, the results of this study support the hypothesis that it is a remnant of the right dorsal aortic root.

[Intraluminal diverticulum of the duodenum]. / Diverticule intraluminal du duodénum.

A case of intraluminal duodenal diverticulum associated with partial situs inversus in a 15 year-old girl is reported. Etiopathogenicity is discussed. The pathological characteristics explain that surgery associated with upper digestive endoscopy had to be performed and why endoscopic excision was not possible in this case.