Absence of bifurcation of the portal vein

Laparoscopic left hepatectomy for a patient with an absence of portal bifurcation using real-time imaging: a case report

BACKGROUND

Absence of portal bifurcation is an extremely rare anomaly that should be recognized preoperatively, especially prior to a major hepatectomy.

CASE PRESENTATION

A 45-year-old woman presented with abdominal pain, and abdominal computed tomography (CT) revealed dilatation of both the common bile duct (CBD) and intrahepatic bile duct (IHBD). Endoscopic retrograde cholangiopancreatography (ERCP) showed CBD and IHBD stones (B2 and B4). The CBD stones were removed, but the IHBD stones could not be, yet there was no evidence of malignancy at the site of IHBD stenosis. Enhanced CT revealed a dilated IHBD, while three-dimensional CT images showed the left portal vein running through the ventral side of the middle hepatic vein, which was diagnosed as the absence of portal vein bifurcation (APB). Laparoscopic left hepatectomy was successfully performed using real-time indocyanine green (ICG) fluorescence imaging.

CONCLUSION

Surgeons should be aware of the possibility of APB, a rare portal vein anomaly, before performing major hepatectomy. Real-time ICG fluorescence imaging may be helpful to ensure the precise anatomy of the liver during laparoscopic surgery.

Description of the Vascular Anatomy of Livers with Absence of the Portal Bifurcation

BACKGROUND

The absence of the portal bifurcation (APB) is a rare anatomic variation, in which the horizontal part of the left portal vein (PV) is missing. The aim of this study was to identify the vascular architecture in livers with APB.

METHODS

Computed tomography data for 17,651 patients were reviewed; five patients (0.03%) were found to present with APB. The liver volume and anatomy of APB patients were compared with those of 30 patients with normal livers.

RESULTS

All the APB patients exhibited an independent posterior branch of the PV. The intrahepatic left PV (LPV) ran through either the ventral (n = 2, 40%) or dorsal side (n = 3, 60%) of the middle hepatic vein. The frequency of medial branches diverging from the LPV was higher in patients with APB than in normal patients (p < 0.001). The left hepatic duct (LHD) ran through the inside of the left lobe along the left PV in 40% of the patients with APB, whereas in the remaining 60% of the patients with APB, the LHD ran on the outside of the liver separately from the left PV and joined the right hepatic duct. The liver volume of the left lateral section was significantly smaller (p = 0.014), and the posterior section was significantly larger (p = 0.014) in patients with APB than in patients with normal livers.

CONCLUSION

The unique anatomical characteristics and the positional relation of the vessels should be considered preoperatively in patients with APB.

Complication of portal vein thrombosis after right hemihepatectomy in a patient lacking the portal vein bifurcation

Absence of portal vein bifurcation is a rare anomaly. We report a patient with this anomaly who underwent right hemihepatectomy for treatment of hepatocellular carcinoma. Although the procedure was carefully performed with a preoperative three-dimensional simulation and intraoperative cholangiography, postoperative portal vein thrombosis occurred. J. Med. Invest. 63: 315-318, August, 2016.

Absent portal vein bifurcation: a rare variant and its clinical significance

Portal vein branching anomaly occurs due to aberration of normal anastomotic patterns and involution of vitelline veins during development of portal vein. Anatomical knowledge of portal vein and its branching pattern is important for hepatobiliary surgeon and gastrointestinal intervention radiologist. We are reporting a case of absence of portal vein bifurcation showing single main intrahepatic portal vein with gradual decreasing caliber distally, in a young female patient on contrast-enhanced computed tomography study of abdomen. Few cases of absence of portal bifurcation have been reported in literature so far.

Extended right hepatectomy in a liver with a non-bifurcating portal vein: the hanging maneuver protects the portal system in the presence of anomalies

INTRODUCTION

Variations in portal vein anatomy occur in 20-35 % of individuals. A non-bifurcating portal vein (PV) was suspected on preoperative imaging in a patient with a large right lobe hepatocellular carcinoma. The single PV curved within the liver parenchyma from right to left supplying second-order branches along its course.

CASE REPORT

Utilizing the hanging maneuver, an extended right hemihepatectomy was safely performed. This approach allowed for preservation of the main PV and its left-sided branches while easily identifying the second-order right branches for ligation.

CONCLUSION

Knowledge of portal vein variations and identification preoperatively by cross-sectional imaging are critical. The hanging maneuver aids in the preservation of the main portal vein and its left-sided branches during right hemihepatectomy in the presence of portal vein anomalies, and this technique can be used to improve safety in hepatobiliary surgery.

A case of absence of extrahepatic portal bifurcation in biliary atresia

The absence of extrahepatic portal bifurcation is a rare anomaly and is considered to be caused by anomalous development of the portal vessels early in fetal life. The portal system develops from two main fetal vessels, the left umbilical vein and right vitelline vein. An anomalous connection of these two vessels early in fetal life results in the absence of bifurcation of the portal vein. We report a case who suffered from biliary atresia complicated with the absence of bifurcation of the portal vein. The patient had an anomalous left hepatic portal vein that ran along the cranial side of the hepatic hilar ductal plate. This is the first report of biliary atresia that was complicated with the absence of extrahepatic portal bifurcation.

Preduodenal portal vein, intestinal malrotation, polysplenia, and interruption of the inferior vena cava: a review of anatomical anomalies associated with gastric cancer

PURPOSE

Anatomical anomalies of visceral organs associated with gastric cancer are extremely rare. Here, we report a case of preduodenal portal vein (PDPV), intestinal malrotation, interruption of the inferior vena cava (IVC), and polysplenia associated with gastric cancer in an adult patient, together with a review of the literature on the anomalies of visceral organs associated with gastric cancer.

METHODS

We describe the diagnosis and surgical treatment in a 63 year-old man who had a preoperative diagnosis of PDPV, intestinal malrotation, interruption of the IVC with azygos continuation, and polysplenia associated with gastric cancer. Fifteen reports, in the English literature up to 2011, on visceral organ anomalies detected in gastric cancer patients were identified by searching Medline.

RESULTS

All of the 15 cases of anomalies associated with gastric cancer, including the present case, were correctly diagnosed by preoperative imaging. Situs anomaly was the most frequent anatomical anomaly detected, and PDPV was observed in only four cases. In 12 cases, gastrectomy was performed, and gastrojejunostomy was done in 1 case.

CONCLUSIONS

Although embryological anomalies such as PDPV, intestinal malrotation, interruption of the IVC, and polysplenia are rarely encountered in abdominal surgery, surgeons must be aware of their possible existence and be able to recognize them to avoid major intraoperative injuries.