Variations of the middle and inferior right hepatic vein: application in hepatectomy

Transversal hepatectomies: Classification and intention-to-treat validation of new parenchyma-sparing procedures for deep-located hepatic tumors

BACKGROUND

Deep-located liver tumors involving hepatic veins at the caval confluence or main Glissonean pedicles generally require a major hepatectomy. An intraoperative ultrasound guidance policy opened a possibility to opt for parenchyma-sparing procedures as alternatives to major hepatectomy, called transversal hepatectomies. We ought to standardize the procedure and analyze the surgical outcome, oncological suitability, and salvageability.

METHODS

This is a retrospective cohort study. All consecutive patients undergoing hepatectomies for liver tumors between January 2005 and August 2020 were reviewed. Transversal hepatectomies were classified as follows: upper transversal hepatectomy: resection of the posterosuperior segments along with at least 1 hepatic vein and preservation of the anteroinferior ones; roller coaster hepatectomy: transversal hepatectomy with tumor vessel detachment from at least 2 hepatic veins; and lower transversal hepatectomy: amputation of the distal portion of at least 1 hepatic vein with tumor vessel detachment from first/second-order Glissonean pedicles. Morbidity, mortality, local recurrences, and salvageability in cases of relapse were considered.

RESULTS

A total of 61 transversal hepatectomies were performed: 40 (66%) upper transversal hepatectomies, 19 (31%) roller coaster hepatectomies, and 2 (3%) lower transversal hepatectomies. The median preserved liver volume was 67% (range 41-86). Mortality was 0, and major morbidity was 6%. Local recurrence occurred in 7 (11%) patients. Ten out of 34 (29%) patients with liver-only recurrence received redo surgery.

CONCLUSION

Transversal hepatectomies offer a new parenchyma-sparing perspective for the management of complex tumor presentation, which would otherwise demand major tissue removal or even unresectability. Safety, adequate local control, and salvageability are further pillars of this approach herein systematized.

Induction of Robust Future Liver Remnant Hypertrophy Before Hepatectomy With a Modified Liver Venous Deprivation Technique Using a Trans-venous Access for Hepatic Vein Embolization

Purpose: Hepatic and/or portal vein embolization are performed before hepatectomy for patients with insufficient future liver remnant and usually achieved with a trans-hepatic approach. The aim of the present study is to describe a modified trans-venous liver venous deprivation technique (mLVD), avoiding the potential risks and limitations of a percutaneous approach to hepatic vein embolization, and to assess the safety, efficacy, and surgical outcome after mLVD. Materials and Methods: Retrospective single-center institutional review board-approved study. From March 2016 to June 2019, consecutive oncologic patients with combined portal and hepatic vein embolization were included. CT volumetric analysis was performed before and after mLVD to assess liver hypertrophy. Complications related to mLVD and surgical outcome were obtained from medical records. Results: Thirty patients (62.7 ± 14.5 years old, 20 men) with liver metastasis (60%) or primary liver cancer (40%) underwent mLVD. Twenty-one patients (70%) had hepatic vein anatomic variants. Technical success of mLVD was 100%. Four patients had complications (three minor and one major). FLR hypertrophy was 64.2% ± 51.3% (mean ± SD). Twenty-four patients (80%) underwent the planned hepatectomy and no surgery was canceled as a consequence of mLVD complications or insufficient hypertrophy. Fifty percent of patients (12/24) had no or mild complications after surgery (Clavien-Dindo 0-II), and 45.8% (11/24) had more serious complications (Clavien-Dindo III-IV). Thirty-day mortality was 4.2% (1/24). Conclusion: mLVD is an effective method to induce FLR hypertrophy. This technique is applicable in a wide range of oncologic situations and in patients with complex right liver vein anatomy.

Hepatic vein in living donor liver transplantation

Right lobe living donor liver transplantation (LDLT) is a major development in adult LDLT that has significantly increased the donor pool by providing larger graft size and by decreasing risk of small-for-size graft syndrome. However, right lobe anatomy is complex, not only from the inflow but also from the outflow perspective. Outflow reconstruction is one of the key requirements of a successful LDLT and venous drainage of the liver graft is just as important as hepatic inflow for the integrity of graft function. Outflow complications may cause acute graft failure which is not always easy to diagnose. The right lobe graft consists of two sections and three hepatic venous routes for drainage that require reconstruction. In order to obtain a congestion free graft, several types of vascular conduits and postoperative interventions are needed to assure an adequate venous allograft drainage. This review described the anatomy, functional basis and the evolution of outflow reconstruction in right lobe LDLT.

Right hepatic venous system variation in living donors: a three-dimensional CT analysis

BACKGROUND

The right hepatic venous system consists of the right hepatic vein (RHV) and inferior RHVs (IRHVs). When the right posterior section is used as a graft for liver transplantation, understanding variations and relationships between the RHV and IRHVs is critical for graft venous return and hepatic vein reconstruction. This study aimed to evaluate variations in the hepatic veins and the relationships between them.

METHODS

The medical records and CT images of patients who underwent hepatectomy as liver donors were assessed retrospectively. The relationship between the veins was evaluated by three-dimensional CT.

RESULTS

The configuration of the posterior section was classified into one of eight types based on the RHV and IRHVs in 307 patients. Type 1a (103 of 307), type 1b (139 of 307) and type 2a (40 of 307) accounted for 91·9 per cent of the total. The diameter of the RHV extending towards the inferior vena cava had a significant inverse correlation with that of the IRHV (r²  = -0·615, P < 0·001). Type 1a, which had no IRHVs, had the RHV with the largest diameter; conversely, type 2a, which had a large IRHV, had the RHV with the smallest diameter.

CONCLUSION

The hepatic venous system of the right posterior section was classified into eight types, with an inverse relationship between RHV and IRHV sizes. This information is useful for segment VII resection or when the right liver is used as a transplant graft.

Inferior right hepatic vein on routine contrast-enhanced CT of the abdomen: prevalence and correlation with right hepatic vein size

AIM

To determine the prevalence of the inferior right hepatic vein (IRHV) in patients undergoing routine contrast-enhanced computed tomography (CECT) of the abdomen and to compare it with the size of the right hepatic vein (RHV).

MATERIALS AND METHODS

Two hundred and twenty-four consecutive patients who underwent routine CECT abdomen, with adequate venous opacification, were included in the study. The number and diameter of IRHVs and the diameter of the RHV was noted in each case.

RESULTS

A total of 214 IRHVs were detected in 126 cases (56.2%) with a mean diameter of 4.15±1.44 mm. The number of IRHVs ranged from one to four (more than one IRHV was present in 39.7% [50/126] of cases). In approximately one-third of cases (46/126), an IRHV ≥5 mm was found. A weak negative correlation was found between size of the RHV and IRHV (Pearson's correlation coefficient -0.222; p=0.01). The RHV was smaller in size in patients with an IRHV (7.34±1.88 mm) than in patients without an IRHV (8.47±1.99 mm) on CECT abdomen. A larger IRHV was associated with a smaller RHV (6.91±2.05 mm).

CONCLUSION

The presence of IRHV on routine CECT abdomen is frequent, and it is not uncommon to encounter more than one IRHV. The diameter of the IRHV has a weak negative correlation with the diameter of the RHV, and a smaller RHV is found in patients with an IRHV.

Liver vascular anatomy: a refresher

To prevent and decrease procedural complications, it is important to identify variants of hepatic vascular anatomy before interventional radiologic procedures, surgery, and liver transplantation. Knowledge of the vascular variants helps in selecting patients and in exploring alternative management options. Non-invasive detailed demonstration of the hepatic vascular anatomy is possible with advanced multi-detector computed tomography (CT) and magnetic resonance (MR) imaging. The objective of this review is to provide a brief overview of clinically relevant hepatic vascular anatomy and important variants.

Imaging of pathology involving the space around the hepatic veins: "perivenous pattern"

We aimed to illustrate diseases involving the potential space around the hepatic veins. Perivenous halo sign can be seen in patients with congestive heart failure or fluid overload. Perivenous involvement can be observed in patients with alcoholic fatty liver disease, which can be focal or diffuse. Metastasis and primary liver tumor spread can also involve this space most likely due to involvement of lymphatics around hepatic veins.

Venous drainage map of the liver for complex hepatobiliary surgery and liver transplantation

BACKGROUND

Inflow and outflow patency of the liver parenchyma is required to maximize the metabolic function of the liver. However, the definition and distribution of hepatic venous drainage regions has yet to be reported. The aim of this study was to define major hepatic venous tributaries and investigate the mean drainage volume of each territory.

METHODS

Three-dimensional (3D) simulations from the livers of 100 healthy donors were reviewed for living donor liver transplantation to determine the distribution of the significant hepatic venous tributaries and the drainage patterns of each segment.

RESULTS

The left hepatic vein (LHV), middle hepatic vein (MHV), and right hepatic vein (RHV) contributed a mean drainage of 20.7%, 32.7%, and 39.6% of the entire liver, respectively. Accessory hepatic veins accounted for remaining 7.0%. The middle right hepatic vein (MRHV) and inferior right hepatic vein (IRHV) accounted for a mean total drainage of 8.0% and 10.6%, respectively, when they present. In addition, major tributaries of hepatic veins were clearly detected, and their typical distributions were described.

CONCLUSIONS

Knowledge of hepatic venous territories is necessary for complex hepatobiliary surgery. This "venous drainage map" may provide useful information for complex liver surgery and transplantation.

Is the absence of Right Hepatic Vein opening into Inferior Vena Cava a contraindication for right lobe liver donation in Living Donor Liver Transplantation? Common hepatic venous trunk-A rare hepatic vein anomaly: A case report and review

•

A rare hepatic venous variation in the voluntary liver donor and the surgical challenge faced by the transplant surgeon.

•

Review of the variations of hepatic venous drainage and their significance in the context of living donor liver transplantation.

•

Surgical maneuver employed in dealing with such a rare variation of hepatic vein in the living donor.

Introduction

In majority of the living liver donors, the left and the middle hepatic veins form a common trunk and the right hepatic vein drains by a separate trunk into the IVC forming two ostial openings. Presentation of Case: This report presents a rare challenge to the operating surgeon in which the three major hepatic veins form a common trunk and drain into the IVC through a single ostial opening. It was detected preoperatively by the routine donor imaging studies.

Discussion

To our knowledge, this type of rare venous anatomy in the setting of living donor liver transplantation has not been described in the literature before. A few studies have described similar anatomy in the cadaveric liver specimen of some particular ethnicity.

Conclusion

This type of a rare anomaly poses challenge to the donor operation and requires a sound expertise on the knowledge of hepatic venous anatomy to perform the donor hepatectomy with the appropriate maneuvering.

Multiplanar imaging of inferior vena cava variants

Inferior vena cava (IVC) variants are rare and are usually detected incidentally. Even though, these variants are by themselves asymptomatic, they can have important clinical, radiological, and surgical implications. In this pictorial essay, we sensitize the reader to various IVC variants by presenting reports of actual patients. A succinct description of the embryological development of these anatomic variants is also provided.

Anatomical variations in the pattern of the right hepatic veins draining the posterior segment of the right lobe of the liver

BACKGROUND

The pattern of drainage in the right posterior lobe of liver varies considerably. The knowledge of this variation is very important while performing various surgeries on the right posterior lobe.

AIM

A study was conducted to see the variations in the pattern of drainage of posterior segment of the right lobe of liver. The aim was to see the variations of right hepatic vein and small accessory hepatic veins draining the posterior segment, the presence of which led to modifications in drainage of posterior segment.

MATERIAL AND METHODS

Sixty formalin fixed adult human liver specimens were dissected manually.

RESULTS

According to the pattern of drainage of tributaries of right hepatic vein, the right hepatic vein was classified into type I, type II, type III and type IV. According to presence of inferior right hepatic vein, three types of drainage of posterior lobe were seen: Type I, (76.36%) right hepatic vein was large, draining wide area of posterior segment. A small inferior right hepatic vein drained the small area of posterior segment. In Type II, (19.92%) both right hepatic and inferior right hepatic veins were medium sized draining the posteroinferior segment of the right lobe concomitantly. In Type III, (32%) accessory veins, the middle right hepatic vein drained the posterosuperior (VII) as well as the posteroinferior (VI) segment. In one specimen, there were numerous middle right hepatic veins draining the right posterior segment. The knowledge of anatomic relationship of veins draining right lobe, is important in performing right posterior segmentectomy.

CONCLUSION

For safe resection of the liver, the complex anatomy of the distribution of the tributaries of the right hepatic vein and the accessory veins have to be studied prior to any surgery done on liver.

Hepatic veins in presurgical planning of hepatic resection: what a radiologist should know

Hepatic resection is considered to be feasible when all malignant nodules can be technically excised. The goal of the surgical approach is to optimize the oncologic resection (negative margins), sparing the non-cancerous hepatic parenchyma. The outflowing hepatic vein (HV) of that particular liver remnant must be intact in order to preserve its function. The purpose of this article is to familiarize radiologists with anatomy and anatomical variants of HVs, with special emphasis on segmental venous drainage for presurgical planning of hepatic resections. We focus on information which radiologist should give to hepatic surgeon to choose proper surgical approach. Radiologist's familiarity with the anatomy and anatomical variants of HVs is essential for accurate surgical planning to avoid venous congestion as postoperative complication. Any clinically important hepatic vein variation detected on presurgical imaging should be carefully recorded in the radiology report.

Preoperative hepatobiliary imaging: what does the radiologist need to know?

Accurate preoperative reporting is essential in guiding the surgeon in deciding when and how to operate safely and effectively. Critically, this relies on an understanding of the operative issues faced by the surgeon, which is not always appreciated by the radiologist. This paper therefore aims to address this, first focusing on relevant anatomical variants, and then issues specific to laparoscopic cholecystectomy, hepatic transplantation, and finally hepatic resection (including cholangiocarcinoma resection). Throughout the paper, there is an emphasis on associated surgical techniques to add context to the discussion.

Surgical impact of an inferior right hepatic vein on right anterior sectionectomy and right posterior sectionectomy

BACKGROUND

In hepatocellular carcinoma, anatomical resection is important because of portal spread. In right anterior sectionectomy (RAS) and right posterior sectionectomy (RPS), the right hepatic vein (RHV) may not correspond with the intersectional plane if an inferior RHV (IRHV) is present. The aim of this study was to evaluate the influence of the IRHV on the exposure of the RHV retrospectively.

METHODS

One hundred ninety-one patients underwent RAS or RPS by the Glissonean pedicle transection method. The calibres of the RHV and IRHV were measured and assessed the extent of exposure of RHV.

RESULTS

One hundred seventeen patients underwent RAS and 74 underwent RPS. The calibre of the RHV averaged 8.0 mm and that of the IRHV, 6.2 mm. Exposure of the RHV was divided into three groups: no exposure 31 (16.2%) (with IRHV, 20 patients; without IRHV, 11 patients), upper half exposure 49 (25.7%; with IRHV, 24; without IRHV, 25) and full exposure 111 (58.1%) (with IRHV, 16; without IRHV, 95). The effect of the IRHV on exposure of the RHV was substantial (P < 0.001).

CONCLUSIONS

The IRHV can affect the course of the RHV and its exposure. Therefore, in RAS and RPS, it is important to evaluate the existence of the IRHV.

A simple formula to calculate the liver drainage volume of the accessory right hepatic vein using its diameter alone

BACKGROUND

The liver sometimes has an accessory middle or inferior right hepatic vein (RHV) in addition to the usually existing superior RHV. In liver surgery, it is important to know the parenchymal drainage volume of these accessory RHVs to avoid postoperative liver dysfunction caused by blood congestion. The purpose of this study was to determine methods to estimate parenchymal drainage volume of such accessory veins.

METHODS

By reviewing the preoperative multidetector-row computed tomography (MDCT) and using specialist software, we investigated the presence of accessory RHVs, the diameter, and the parenchymal drainage volume of each vein, and we determined correlations between the diameter and parenchymal drainage volume of the accessory RHVs.

RESULTS

Middle (median diameter, 4.9 mm) and inferior (median diameter, 5.0 mm) RHVs were present in 15% and 47%, respectively, in this study. The median parenchymal drainage volume of the superior, middle, and inferior RHVs was 401 mL, 64 mL, and 116 mL, respectively. There were positive correlations between diameters and the parenchymal drainage volume of accessory RHVs (middle RHV: y = 27.1x-45.7, r = .78, P < .05; inferior RHV: y = 34.8x-57.8, r = .80, P < .01), which made it possible to calculate the parenchymal drainage volume of these veins using their diameters alone.

CONCLUSION

Approximately half of the livers in this study had 1 or 2 accessory RHV(s), the parenchymal drainage volume of which was substantial. We can calculate the parenchymal drainage volume from the diameter of each accessory RHV on CT, which enables liver surgeons to determine how to manage these hepatic veins.

Changes in hepatic venous morphology with cirrhosis on MRI

PURPOSE

To identify changes in vascular morphology on magnetic resonance imaging (MRI) in patients with cirrhosis and to compare these findings to liver donors.

MATERIALS AND METHODS

Patients undergoing liver transplantation with biopsy-proven cirrhosis (n = 74) and liver donor candidates (n = 85) underwent dynamic gadolinium-enhanced 3D MR at 1.5T. Vessel diameters were measured independently by three radiologists and features of cirrhosis were identified and correlated with cirrhosis.

RESULTS

Hepatic veins were smaller in patients with cirrhosis (4.9, 4.5, and 5.0 mm for right, middle, and left vs. 9.9, 7.6, and 8.9 mm in donors, P << 0.001) and were negatively correlated with cirrhosis (P < 0.001). Right hepatic vein (RHV) <5 mm diagnosed cirrhosis with 59% sensitivity and 99% specificity; the sensitivity and specificity were 88% and 85% for RHV <7 mm. Main portal vein was minimally larger in cirrhosis, 14 versus 12 mm (P < 0.001) in donors. Right portal veins were smaller in cirrhotic patients, 6.5 and 6.2 mm compared to 8.4 and 7.6 mm (P << 0.001), respectively, in donors.

CONCLUSION

Vascular features of cirrhosis include small hepatic veins, minimally enlarged main portal vein, and small intrahepatic portal veins; these features may facilitate identification of cirrhosis.

Budd-Chiari syndrome: a review of imaging findings

Budd-Chiari syndrome is an uncommon, often fatal disorder resulting from an obstructed hepatic venous outflow tract. The obstructive lesion is situated in the main hepatic veins, in the inferior vena cava or in both. The nature, location and extension of the obstruction can be displayed on diagnostic imaging techniques. In addition to this direct evidence, the indirect findings of venous obstruction such as the presence of intra- and extrahepatic collateral veins, when combined with the altered morphology and enhancement pattern of the liver enables one to arrive at a confident diagnosis. In patients with suspected Budd-Chiari syndrome, gray-scale sonography with complementary support of color and pulsed Doppler examinations is the first step in approaching the diagnosis. It is followed by a contrast-enhanced cross-sectional technique, preferrentially by MR angiography. The patients with a high clinical suspicion of Budd-Chiari syndrome may undergo hepatic venography or venacavography directly so that a potential of recanalization (e.g. percutaneous transluminal angioplasty with or without stent placement or TIPS) of the obstructed segment under the guidance of these techniques would not be delayed.

Bisegmentectomie 7–8 : intérêt du repérage pré-opératoire d'une veine hépatique inférieure droite (VHID)

The extent of hepatic resection is often determined by the hepatic veins and their relation to the tumor. A need to transect the right hepatic vein at its entry into the vena cava indicates a need to remove the entire right posterior segment. About six cases, the aim of the study was to remind that under certain circumstances the posteroinferior area may be preserved. The circumstances which allow such preservation are the presence of a stout inferior right hepatic vein and the ability to recognize the presence of the vein in the preoperative staging. In patients with possible impaired hepatic function (cirrhosis, chemotherapy), preservation of hepatic parenchyma is an important consideration during resection for hepatic tumors.

Transatrial Stent Placement for Treatment of Inferior Vena Cava Obstruction Secondary to Extension of Intracardiac Tumor Thrombus from Hepatocellular Carcinoma

Two cases of superior vena cava-to-inferior vena cava (IVC) transatrial stent placement to palliate obstruction of the IVC secondary to the intracardiac extension of hepatocellular carcinoma are reported. Both patients presented with debilitating edema of the trunk and lower extremities and varying degrees of hepatic venous obstruction resulting in Budd-Chiari syndrome. One patient required the adjunctive creation of a percutaneous portocaval shunt and the second patient responded to transatrial stent placement alone. Both patients' functional status improved and edema markedly decreased after endovascular therapy.

Using multidetector CT for preoperative vascular evaluation of liver neoplasms: technique and results

OBJECTIVE

The purpose of our study was to evaluate the performance of CT angiography using multidetector CT (MDCT) for preoperative vascular evaluation in candidates who were scheduled for liver neoplasm resection.

SUBJECTS AND METHODS

Forty-two consecutive subjects with malignant liver tumors scheduled for resection were studied with multiphase MDCT. The first 22 subjects underwent both multiphase MDCT angiography and catheter angiography before surgery. The subsequent 20 subjects underwent only preoperative CT angiography. Postprocessing was performed, and the images were analyzed for the depiction of arterial, portal vein, and hepatic vein anatomy and for the identification of important vascular variants. The postprocessing findings were compared and correlated with the findings from catheter angiography (22/42) or intraoperative sonography (42/42) and surgery (42/42).

RESULTS

Arterial anomalies were detected on the images of 17 of 42 patients, including a replaced right hepatic artery in five, replaced left hepatic artery in six, accessory right and left hepatic arteries in two, common trunk for the celiac and superior mesenteric arteries in one, and early bifurcation of the celiac artery in one. In 22 patients in whom catheter angiography confirmation was available, the number of arteries and almost all the significant anomalies were correctly identified on CT angiography (accuracy, 97%; sensitivity, 94%; specificity, 100%). In the subset of 20 patients who underwent MDCT angiography without catheter angiography confirmation, all clinically relevant information was provided by CT angiography. The portal and hepatic vein anatomy and the relationships of the liver tumors to the neighboring venous structures were shown on CT.

CONCLUSION

Multidetector CT provides valuable preoperative information about hepatic vascular architecture and can be used as a noninvasive alternative to catheter angiography before oncologic liver surgery.

Anatomical variations in the pattern of the right hepatic veins: possibilities for type classification

A morphological study of the right hepatic veins (RHVv) was conducted based on the shape and the confluence pattern of the superior right hepatic vein (SRHV) and the presence of accessory right hepatic veins. The study was performed in 110 undamaged, randomly selected, cadaveric human livers prepared using the corrosion cast methodology. The principles for classifying the RHVv into types were as follows: the length of the vein trunk, the confluence of 2 or 3 main tributaries that form a trunk, and the accessory right hepatic veins that modify the venous drainage of the right side of the liver. Four types of SRHV were identified. Type 1 (20 %), type 2 (40 %) and type 3 (25 %) were the most common, while type 4 (15 %) was linked to the accessory right hepatic veins in cases where they drain a surgically important part of the liver. Accessory right hepatic veins were found in a total of 31 casts (28 %). The hepatocaval confluence was studied and the tributary-free part of the SRHV trunk before it entered the inferior vena cava was measured. The tributary-free part of the SRHV was longer than 1 cm in 77 % of the casts. Anastomoses between the terminal tributaries of the veins involved in the drainage of the right side of the liver were also investigated.