Direct intrahepatic portocaval shunt through transhepatic puncture via retrohepatic inferior vena cava: applied anatomical study

Direct intrahepatic portocaval shunt (DIPS) or transjugular transcaval intrahepatic portosystemic shunt (TTIPS) to treat complications of portal hypertension: Indications, technique, and outcomes beyond Budd-Chiari syndrome

Transjugular intrahepatic portosystemic shunt (TIPS) is nowadays the benchmark treatment of severe portal hypertension complications. However, besides usual contraindication to the procedure (namely recurrent hepatic encephalopathy, severe liver dysfunction, right heart failure and/or pulmonary hypertension), TIPS appears regularly unfeasible due to abnormal and/or distorted anatomy. In this situation, the only non-surgical approaches to treat severe portal hypertension consist in the creation of an intrahepatic portocaval shunt from percutaneous (direct intrahepatic portocaval shunt - DIPS) or transjugular route (transjugular transcaval intrahepatic portosystemic shunt - TTIPS). These procedures have been rapidly adopted in patients with Budd-Chiari syndrome but are only poorly reported in patients with cirrhosis and without BCS. Considering the broadening landscape of TIPS indication in patients with cirrhosis within the last ten years, we aimed to describe the techniques, safety and efficacy of DIPS and TTIPS procedures as an alternative to TIPS in case of unfavourable anatomy.

A South Indian Cadaveric Study About the Relationship of Hepatic Segment of Inferior Vena Cava with the Liver

INTRODUCTION

Inferior Vena Cava (IVC) is the largest vein of the body. It runs vertically upwards in the abdomen, behind the liver. Its course is very constant in relation to liver. However, the amount of liver parenchyma related to it can vary from person to person. The data regarding its course and relations may be very useful to radiologists and surgeons during surgical treatment procedures for Budd-Chiari syndrome, liver carcinoma, liver transplant, venous cannulations and many other clinical procedures.

AIM

Aim of this study was to document the incidence of straight and curved course of IVC in relation to liver and also to note the pattern in which the liver tissue was related to the IVC.

MATERIALS AND METHODS

In the current study, 95 adult cadaveric livers were observed; specifically to study the course/direction of the hepatic segment of IVC in relation to the liver. The extent of liver tissue related to various aspects of IVC was also studied. The course of the IVC was classified as straight and curved; and the relationship of liver parenchyma to the IVC was classified into 6 categories. The data was expressed as percentage incidence.

RESULTS

In 78.94% cases, the IVC had a straight course in relation to the liver; whereas in 21.06% cases, it had a left sided curve (concavity of the curve towards the caudate lobe) in its course. In 6.31% cases, IVC travelled in a tunnel, being encircled by the liver parenchyma all around; in 36.84% cases, it was covered by liver parenchyma on front and sides so that only posterior surface of IVC was visible; in 3.15% cases it was covered by liver tissue on front, sides and also partly on posterior aspect; in 50.52% of cases, its anterior surface, sides and left edge of the posterior surface was covered by liver tissue; and in 3.15% cases it was covered only from the front by the liver tissue.

CONCLUSION

The data being reported here might be useful for surgeons while planning and executing various hepatic surgeries and also to the radiologists in planning and performing venous cannulation and therapeutic procedures. Since in many livers, the curvature of IVC was associated with enlarged caudate lobe, the curved IVC could hint about the increase in the volume of caudate lobe or liver itself.

Anatomy of the retrohepatic segment of the inferior vena cava and the ostia venae hepaticae with its clinical significance

PURPOSE

The present study was undertaken to provide morphological data regarding the retrohepatic segment of the inferior vena cava (RHIVC) and ostia venae hepaticae with an emphasis on the clinical significance of the observations made.

METHODS

This was an observational study conducted on 160 apparently healthy, randomly selected, cadaveric adult human livers fixed in 10% formalin. The distribution of the hepatic venous openings was studied by dividing the interior of the RHIVC into 16 quadrants. These openings were classified as large, medium, small and very small openings based on their diameter and were also classified as single/double/triple/quadruple according to the number of veins opening into them.

RESULTS

The median length of RHIVC was 7.3 cm (6.2-8.4) and was directed obliquely with respect to the vertical axis of the liver in 92.5% of cases. A total of 1,376 ostia venae hepaticae were observed, and the median number of openings per liver was 7 (5-9). The right hepatic vein had a single opening in 156 (97.5%) and the left and middle hepatic veins had a common opening in 144 (90%) cases. A longitudinal area on the anterior wall of the RHIVC, to the right side of the midline, was relatively avascular with 10.1% of the venous openings, of which 70% were single openings of the right dorsal vein having a small diameter (0.1-0.5 cm).

CONCLUSION

During liver hanging maneuver, rightward direction of the dissecting forceps would avoid injury to the caudate vein and allow access to the safe avascular space in the RHIVC.