An anomalous portal vein crossing the lesser sac and ending at the upper part of ductus venosus / 대한해부학회지

In serial sagittal sections of a fetus on week 9 (crown-rump length, 36 mm), we incidentally found absence of the usual portal vein through the hepatoduodenal ligament. Instead, an anomalous portal vein originated behind the pancreatic body, crossed the lesser sac and merged with the upper part of the ductus venosus. During the course across the lesser sac, the vein provided a deep notch of the liver caudate lobe (Spiegel's lobe). The hepatoduodenal ligament contained the hepatic artery, the common bile duct and, at the right posterior margin of the ligament, and a branch of the anomalous portal vein which communicated with the usual right branch of the portal vein at the hepatic hilum. The umbilical portion of the portal vein took a usual morphology and received the umbilical vein and gave off the ductus venosus. Although it seemed not to be described yet, the present anomalous portal vein was likely to be a persistent left vitelline vein. The hepatoduodenal ligament was unlikely to include the left vitelline vein in contrast to the usual concept.

Neonatal vitelline vein aneurysm with thrombosis: prompt treatment should be needed

Vitelline veins are a pair of embryonic structures. The veins develop the portal vein system. Serious problems occur if the vitelline vein does not regress and becomes an aneurysm. Thrombus formation in the vitelline vein aneurysm could lead to portal vein thrombosis and portal hypertension unless promptly and correctly treated. Though vitelline vein aneurysm is an extremely rare anomaly, it rapidly progresses to portal vein thrombosis that requires prompt diagnosis and treatment. We reported a case of neonatal vitelline vein aneurysm and thrombosis that was cured by prompt operation.

A Clinical Study of Vitelline Duct and Vessel Remnants

Of 72 cases with vitelline duct and vessel remnants, 45 (62.5%) had symptomatic lesions (mean age, 27.9 months) with male preponderance (4.6: 1). Among the 45 symptomatic lesions, there were 22 cases of Meckel's diverticulum, 6 cases of Meckel's diverticulum with fibrous band attached to the umbilicus, 6 cases of patent vitelline duct, 5 cases of vitelline artery remnant as fibrous band, 2 cases of umbilical sinus, 2 cases of umbilical polyp, and 2 cases of vitelline cyst. Twenty three cases (51%) presented with intestinal obstruction, 6 (13%) with rectal bleeding, 4 (9%) with perforated Meckel's diverticulum, 5 with intestinal fluid drainage through umbilicus, 5 with umbilical lesion, and 1 with abdominal mass. Intestinal obstruction due to fibrous band developed at infancy (average age, 4.6 months). About 82% of complicated Meckel's diverticulum (n=28) presented less than 4 years of age. Seventeen Meckel's diverticulums, 8 obliterated vitelline artery remnants, and 1 vitelline vein remnant as fibrous band were found incidentally at laparotomy.