The inferior right hepatic vein: ultrasonic demonstration

Liver Anatomy 2.0 Quiz: Test Your Knowledge

The liver is one the largest organs in the abdomen and the most frequent site of metastases for gastrointestinal tumors. Surgery on this complex and highly vascularized organ can be associated with high morbidity even in experienced hands. A thorough understanding of liver anatomy is key to approaching liver surgery with confidence and preventing complications. The aim of this quiz is to provide an active learning tool for a comprehensive understanding of liver anatomy and its integration into clinical practice.

Relationship of the Presence of the Inferior Right Hepatic Vein with the Right Hepatic Vein Diameter and CT Liver Volumetry

Background  Right hepatic venous anatomy, right lobe volume, and percentage of remnant liver are issues to be considered in preoperative planning especially transplantation. Objectives  The aim of this study was to investigate the relationship of the presence of the inferior right hepatic vein (IRHV) with the right hepatic vein (RHV) diameter, right lobe volume, and percentage of remnant liver. Materials and Methods  In t his cross-sectional study, the computed tomography (CT) images of 90 patients who underwent triphasic CT for being living liver donation were evaluated retrospectively. The number and diameter of IRHVs and the diameter of main RHV were recorded. For the liver volume analysis, a deep learning-based automatic liver segmentation (Hepatic VCAR) program was used. A virtual hepatectomy plane was drawn, where the right and left liver volumes were found and the percentage of the left lobe to the total liver volume was calculated. Pearson's correlation analysis was used for correlation analysis and Student's t -test was used to compare parameters. Results  A total of 74 IRHVs were detected in 53 (58.88%) of 90 patients. There were no differences in the percentage of remnant left lobe volume, right lobe volume, and RHV diameter between the IRHV (+) and (-) groups. The RHV diameter had a weak negative correlation with the IRHV diameter, and a weak positive correlation with the right lobe volume. Conclusions  The percentage of remnant left lobe volume, right lobe volume, and RHV diameter did not differ in liver donors with and without an IRHV. The RHV diameter had a weak negative correlation with the IRHV diameter and a weak positive correlation with the right lobe volume.

Upper Transversal Hepatectomy for Pediatric Liver Tumors Based on the Inferior Right Hepatic Vein

Introduction:

Tumors located at the hepatocaval junction with the involvement of hepatic veins conventionally warrant major liver resections. Appreciation of sizeable inferior right hepatic vein can allow preservation of uninvolved inferior segments of the liver.

Operative Technique:

Preoperative and intraoperative identification of sizeable inferior right hepatic and other accessory or communicating veins in combination of intra-operative ultrasound guidance for resection to preserve inferior segments of the liver with adequate venous drainage. Application of upper transversal resections for pediatric liver tumors at the hepatocaval confluence was illustrated with description of operative technique and patient selection.

Conclusions:

Parenchymal preserving surgeries are possible for pediatric liver tumors located at the hepatocaval confluence by identification of accessory draining veins to the inferior segments. This along with meticulous parenchymal dissection with ultrasound guidance to preserve all uninvolved veins is key to safe upper transversal resections.

Surgical relevance of anatomic variations of the right hepatic vein

BACKGROUND

Variations in the anatomy of hepatic veins are of interest to transplant surgeons, interventional radiologists, and other medical practitioners who treat liver diseases. The drainage patterns of the right hepatic veins (RHVs) are particularly relevant to transplantation services.

AIM

The aim was to identify variations of the patterns of venous drainage from the right side of the liver. To the best of our knowledge, there have been no reports on RHV variations in in a Caribbean population.

METHODS

Two radiologists independently reviewed 230 contrast-enhanced computed tomography scans performed in 1 year at a hepatobiliary referral center. Venous outflow patterns were observed and RHV variants were described as: (1) Tributaries of the RHV; (2) Variations at the hepatocaval junction (HCJ); and (3) Accessory RHVs.

RESULTS

A total of 118 scans met the inclusion criteria. Only 39% of the scans found conventional anatomy of the main hepatic veins. Accessory RHVs were present 49.2% and included a well-defined inferior RHV draining segment VI (45%) and a middle RHV (4%). At the HCJ, 83 of the 118 (70.3%) had a superior RHV that received no tributaries within 1 cm of the junction (Nakamura and Tsuzuki type I). In 35 individuals (29.7%) there was a short superior RHV with at least one variant tributary. According to the Nakamura and Tsuzuki classification, there were 24 type II variants (20.3%), six type III variants (5.1%) and, five type IV variants (4.2%).

CONCLUSION

There was significant variation in RHV patterns in this population, each with important relevance to liver surgery. Interventional radiologists and hepatobiliary surgeons practicing in the Caribbean must be cognizant of these differences in order to minimize morbidity during invasive procedures.

Preserving inferior right hepatic vein enabled bisegmentectomy 7 and 8 without venous congestion: a case report

Background

In hepatectomy, the preservation of portal perfusion and venous drainage in the remnant liver is important for securing postoperative hepatic function. Right hepatectomy is generally indicated when a hepatic tumor involves the right hepatic vein (RHV). However, if a sizable inferior RHV (IRHV) exists, hepatectomy with preservation of the IRHV territory may be another option. In this case, we verified the clinical feasibility of anatomical bisegmentectomy 7 and 8 with RHV ligation, averting the right hepatic parenchyma from venous congestion, utilizing the presence of the IRHV.

Case presentation

A 70-year-old man was presented with a large hepatic tumor infiltrating the RHV on computed tomography during a medical checkup. The patient was diagnosed with hepatocellular carcinoma (HCC), T2N0M0, stage III. Right hepatectomy was first considered, but multi-detector computed tomography (MDCT) also revealed a large IRHV draining almost all of segments 5 and 6, suggesting that IRHV-preserving liver resection may be another option. The calculated future remnant liver volumes were 382 mL (26.1% of the total volume) after right hepatectomy and 755 mL (51.7% of the total volume) after anatomical bisegmentectomy 7 and 8; therefore, we scheduled IRHV-preserving anatomical bisegmentectomy 7 and 8 considering the prevention of postoperative liver failure and increased chance of performing repeat resections in cases of recurrence. Preoperative three-dimensional simulation using MDCT clearly revealed the portal perfusion area and venous drainage territories by the RHV and IRHV. There was an issue with invisibility of the anatomical resection line of segments 7 and 8, which was completely dissolved by intraoperative ultrasonography using Sonazoid and the portal dye injection technique with counter staining. The postoperative course in the patient was uneventful, without recurrence of HCC, for 30 months after hepatectomy.

Conclusions

IRHV-preserving anatomical bisegmentectomy 7 and 8 is a safe and feasible procedure utilizing the three-dimensional simulation of the portal perfusion area and venous drainage territories and the portal dye injection technique.

Supplementary Information

The online version contains supplementary material available at 10.1186/s40792-021-01184-w.

Correlation of clinical features with inferior right hepatic vein incidence: a three-dimensional reconstruction-based study

PURPOSE

The correlation between right hepatic vein (RHV) diameter and inferior RHV (IRHV) incidence and that between IRHV incidence and other clinical features remain unclear. We investigated factors correlated with IRHV incidence as well as provide a simple and reliable method for predicting IRHV presence preoperatively.

METHODS

We obtained computed tomography (CT) imaging data of 1980 patients from the Department of Radiology, Qingdao Municipal Hospital, from July 1, 2016, to July 1, 2017. We excluded patients with heart disease, inferior vena cava (IVC) disease, history of liver surgery or trauma, space-occupying lesions in the liver, and other diseases, which can cause hepatic hemodynamic changes. CT images of patients were three-dimensionally reconstructed. We measured RHV and IRHV diameter as well as the angle between the RHV and the IVC.

RESULTS

Data on 299 patients were included in this study; the incidence of IRHV was 34.44%. Sex, age, and the angle between the RHV and IVC did not correlate with IRHV incidence. RHV diameter negatively correlated with IRHV incidence (P < 0.05). The area under the receiver-operating characteristic curve for IRHV incidence was 0.878. The diagnostic threshold value of RHV diameter was 8.86 mm.

CONCLUSION

A negative correlation was found between RHV diameter and IRHV incidence, suggesting that IRHV is absent with RHV diameter > 8.86 mm, but is present with RHV diameter < 8.86 mm. This suggests that measuring only RHV diameter can predict the presence of an IRHV when IRHV-related hepatectomy and IRHV preserved living donor liver transplantation are needed.

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.

Linear endoscopic ultrasound evaluation of hepatic veins

Liver resection surgery can be associated with significant perioperative mortality and morbidity. Extensive knowledge of the vascular anatomy is essential for successful, uncomplicated liver surgeries. Various imaging techniques like multidetector computed tomographic and magnetic resonance angiography are used to provide information about hepatic vasculature. Linear endoscopic ultrasound (EUS) can offer a detailed evaluation of hepatic veins, help in assessment of liver segments and can offer a possible route for EUS guided vascular endotherapy involving hepatic veins. A standard technique for visualization of hepatic veins by linear EUS has not been described. This review paper describes the normal EUS anatomy of hepatic veins and a standard technique for visualization of hepatic veins from four stations. With practice an imaging of all the hepatic veins is possible from four stations. The imaging from fundus of stomach is the easiest and most convenient method of imaging of hepatic veins. EUS of hepatic vein and the tributaries is an operator dependent technique and in expert hands may give a mapping comparable to computed tomographic and magnetic resonance imaging. EUS of hepatic veins can help in identification of individual sectors and segments of liver. EUS guided interventions involving hepatic veins may require approach from different stations.

Morphological Characteristics and Frequency of Accessory Right Hepatic Veins - Evaluation with Computed Tomography

SUMMARY – In the liver, there are many vascular variants, which are important in liver surgery, the presence of accessory right hepatic veins (aRHVs) in particular. Their frequency, number and diameter vary considerably. Detailed imaging diagnostics with computed tomography (CT) should be undertaken before surgery. The aim of our study was to examine the characteristics of aRHVs and their demographic correlations. The study included data on 188 patients that underwent CT examination of the abdomen with contrast media, 103 men (54.8%) men and 85 (45.2%) women, mean age 63.1±14.3 (range, 21-94) years. The measurements of hepatic veins were carried out on CT images, which were obtained from the Clinical Institute of Radiology, University Medical Centre of Ljubljana. Forty-five of 142 patients had at least one aRHV: one aRHV in 37 (26.1%) cases, two aRHVs in seven (4.9%) cases, and three aRHVs in one (0.7%) case. The incidence of aRHV was between 24% and 39.3% (mean, 31.7%) and of more than one aRHV between 2.3% and 10.3% with 95% confidence interval (CI). Based on the test of proportions, the proportion of cases with inferior aRHV of at least 7 mm was between 7.2% and 18.1% with 95% CI. The mean distance between the aRHV and the main RHV confluences into the inferior vena cava was 3.73 cm (between 3.32 cm and 4.13 cm, 95% CI). The proportion of cases with confluence distance of at least 4 cm was between 21.6% and 49.5% in cases with at least one aRHV. In cases with more than one aRHV, the distance between the middle aRHV and the main RHV ranged from 1.90 cm to 4.32 cm (95% CI). The T-test of independent samples showed no effect of age on the incidence of accessory veins (p=0.18), and the test of differences of interests showed no impact of sex (p=0.75). Evaluation of the incidence and diameter of aRHVs is of great importance for safe surgical procedure. Their presence can change the surgeon’s decision in 10%-20% of cases when employing appropriate imaging technique. CT examination, which is easily accessible and minimally invasive for patients, was successful in only 80% cases, when using standard protocol for CT scanning.

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.

Verification of inferior right hepatic vein-conserving segments 7 to 8 resection of the liver

This study aims to investigate the safety of inferior right hepatic vein (IRHV)-conserving surgery by comparing the surgical data and postoperative complications between IRHV-conserving segments 7 to 8 (S7 to S8) resection and conventional right hemihepatectomy (RH). Five patients who underwent IRHV-conserving S7 to S8 segmentectomy between 2007 and 2011 (IRHV group) and 25 liver cancer patients who underwent RH without biliary tract reconstruction during the same period (RH group) were investigated. The surgical data, postoperative complications, and duration of hospital stay were compared. The IRHV and RH groups included 2 (40%) and 13 (52%) hepatocellular carcinoma patients, respectively. There were no significant differences in liver function before surgery between the groups. The presence of the IRHV did not adversely affect the processing of the short hepatic vein or frontal dissection of the inferior vena cava. The operative time was shorter (median, 366 minutes versus 501 minutes; P = 0.0001), the postoperative bilirubin level was lower (12 mg/dL versus 1.8 mg/dL; P = 0.037), and the duration of hospital stay was shorter (10 days versus 14 days; P = 0.002) in the IRHV group. No significant differences were noted in the intraoperative blood loss, postoperative transaminase levels, or the incidence of severe complications (Clavien grade IIIb or higher) between the groups. IRHV-conserving resection of the liver is a safe surgical procedure that is useful in preventing postoperative elevation of bilirubin level and in shortening the duration of hospital stay.

Development of Collateral Pathways in Tumor Obstruction of Confluence of the Hepatic Veins: Neither Fortuitous nor Innocuous

BACKGROUND

Except in Budd-Chiari syndrome, alternative drainage pathways have been described rarely. The aim was to describe the alternative collaterals pathways due to tumor hepatic vein (HV) confluence obstruction and its impact in the setting of liver resection.

STUDY DESIGN

Between 2006 and 2014, preoperative CT scans of 41 patients resected for malignant tumor(s) compressing the HV confluence were assessed for the presence of accessory veins and collateral veins. A 2:1 matched control group was used for comparison of intraoperative outcomes.

RESULTS

Intrahepatic collaterals were observed in 28 (68%) patients, mostly between segments 3/4b and 5/4b, and subcapsular collaterals were observed in 12 (29%) patients. Patients with isolated right HV obstruction and with an accessory right HV present had fewer collateral pathways develop than patients without (6 of 10 patients [60%] vs 18 of 19 [95%]; p = 0.036). Segment 1 hypertrophy was present in only 6 (15%) patients. Compared with the control group, there was a significant increase in blood loss (900 mL [range 100 to 3,500 mL] vs 500 mL [range 100 to 2,600 mL]; p < 0.001), transfusion requirements (71% vs 15%; p < 0.001), and vascular clamping (hepatic pedicle: 85% vs 72%; p < 0.001, inferior vena cava: 41% vs 11%; p < 0.001) in case of HV obstruction.

CONCLUSIONS

Development of collateral pathways is not fortuitous and depends on the number of HVs involved and pre-existing accessory veins. The increased blood loss observed in patients with collaterals leads to consider specific vascular clamping.

Reappraisal of the inferior right hepatic vein preserving liver resection

BACKGROUND

To resect tumors infiltrating to the right hepatic vein at its root, right hemihepatectomy or that following portal vein embolization (PVE) is applied. If the IRHV is sizable, the IRHV preserving liver resection can be another option.

METHODS

Between 1994 and 2007, the IRHV preserving liver resection was performed in 21 patients (IRHV group). The short-term outcomes after surgery of them p.

RESULTS

There were no mortality and no significant difference between the IRHV and RH groups concerning the blood loss, the morbidity rates and the duration of hospital stay. The median operation time was shorter in the IRHV group than in the RH group (393 vs. 480 min, p = 0.0409). The median weight of resected specimen of the IRHV group was 293 g (range: 20-982), which was significantly lighter than that of the RH group (median: 680 g [250-4,300], p < 0.001). The median percentage of resected volume to standard liver volume was significantly smaller in the IRHV group than in the RH group (25.8 vs. 52.2%, p < 0.001).

CONCLUSION

The IRHV preserving liver resection remains a safe and useful procedure.

Inferior right hepatic vein-preserving major right hepatectomy for hepatocellular carcinoma in patients with significant fibrosis or cirrhosis

BACKGROUND

Liver resection represents a most effective treatment for hepatocellular carcinoma (HCC). The extent of hepatectomy for HCC involves maintaining a tricky balance between radical resection of tumors and preservation of sufficient liver parenchyma. Generally, removal of the right hepatic vein often involves resection of the whole posterior right lobe, which may prevent patients with impaired liver function from maintaining a functional reserve and could also limit the future liver remnant from curative hepatectomy. As a common anatomic variation, preservation of the inferior right hepatic vein (IRHV) may enable preservation of liver segment 6, even when the right hepatic vein has to be removed. In the present study, we report our experience with IRHV-preserving major right hepatectomy.

METHODS

From February 2009 to December 2011, eight trisegmentectomies 5-7-8 and two segmentectomies 4-5-7-8 were performed with the IRHV-sparing technique on patients with HCC and significant fibrosis or cirrhosis. Data including demographic information, preoperative evaluations, postoperative outcomes, and follow-up results were collected and evaluated.

RESULTS

All patients survived and recovered from hepatectomy. The incidence of complications was higher in cirrhotic patients. The 1-year overall survival rate was 80 %, and the 1-year disease free survival rate was 60 %.

CONCLUSIONS

IRHV-preserving major right hepatectomy increases the resectability of HCC. Intraoperative ultrasonography is recommended to facilitate protection of the IRHV. This technique is safe with careful preoperative evaluation and meticulous perioperative care. The short-term outcome of IRHV-preserving liver resections is satisfactory.

Predicting coverage of transverse subcostal sonography with the use of previous computed tomography before a sonographic liver examination: a prospective study

OBJECTIVES

The purpose of this study was to assess the coverage of transverse subcostal sonography in the supine position by using computed tomography (CT) performed before a sonographic liver examination as a predictor of sonographic coverage.

METHODS

A total of 124 patients (87 men and 37 women; mean age, 55.55 years; range, 24-79 years) who underwent abdominal CT and subsequent liver sonography were enrolled. All patients were assessed for the coverage of transverse subcostal sonography in the supine position by consensus of 2 radiologists. We evaluated the correlation between the level of the posterior rib against the liver dome on axial CT and a sonographic coverage scoring system using Spearman partial correlation analysis. The optimal cutoff value of the liver position and other potential factors associated with sonographic coverage were analyzed.

RESULTS

Among age, sex, body mass index, interposition of bowel around the gallbladder fossa, atrophic changes from cirrhotic liver, and liver position, liver position was the only independent factor associated with sonographic coverage (P < .001). Liver position and the sonographic coverage score were moderately negatively correlated, with statistical significance (r = -0.44; P < .001). The optimal cutoff value for the level of the hepatic dome was at the 10th posterior rib on axial CT.

CONCLUSIONS

Liver position is the only independent factor associated with the coverage of transverse subcostal sonography in the supine position. If it is above the 10th posterior rib level, we can predict difficulty in adequate sonographic coverage of the liver.

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.

Hepatectomy preserving drainage veins of the posterior section for liver malignancy invading the right hepatic vein: an alternative to right hepatectomy

BACKGROUND

Although a right hepatectomy (RH) traditionally has been performed for liver tumors infiltrating the main trunk of the right hepatic vein (RHV), the presence of drainage veins of the posterior section (DVPS) beside the RHV provides a chance to preserve their draining area even if the main trunk of the RHV is removed.

METHODS

Since 2005, we systematically have performed DVPS-preserving hepatectomies whenever possible. In the present study, we describe our experience treating 12 consecutive patients who underwent this procedure.

RESULTS

We performed the following types of liver resections concomitant with the main trunk of the RHV without packed red cell transfusion, liver failure, or 90-day mortality: extended right anterior sectionectomy in 2 patients, extended segmentectomy 7 in 3, extended segmentectomy 8 in 2, and partial resection of segment 7 in 2 and segment 8 in 3. Postoperative morbidity was observed in 4 (33%) cases, all of which had pleural effusion requiring a tap. A free resection margin was obtained in all patients.

CONCLUSIONS

This procedure could be a useful alternative to RH, providing a chance for radical liver resection with minimal parenchymal sacrifice in selected patients with DVPS.

Venous reconstruction based on virtual liver resection to avoid congestion in the liver remnant

BACKGROUND

Hepatic vein (HV) reconstruction may prevent venous congestion following resection of liver tumours that encroach on major HVs. This study aimed to identify criteria for venous reconstruction based on preoperative evaluation of venous congestion.

METHODS

A volumetric analysis using image-processing software was performed in selected patients with liver tumours suspected on preoperative imaging of major HV invasion. The size of the non-congested liver remnant (NCLR) was calculated by subtracting the congested area from the liver remnant. Venous reconstruction was scheduled in patients who met the following criteria: normal liver function (indocyanine green retention rate at 15 min (ICGR(15) ) of less than 10 per cent) with a NCLR smaller than 40 per cent of total liver volume (TLV), or liver dysfunction (ICGR(15) 10-20 per cent) with a NCLR smaller than 50 per cent of TLV. Surgical outcomes and liver regeneration were investigated.

RESULTS

A total of 55 patients with suspected HV invasion were enrolled. Sacrifice of one or more HVs was deemed possible in 37 patients. Venous reconstruction was scheduled in 18 patients. At operation, there was seen to be no venous involvement in 11 patients. The HV was sacrificed in 29 patients, and preserved or reconstructed in 24. Volume restoration ratios at 3 months were similar in the sacrifice (88 per cent) and preserve (87 per cent) groups. Operating time was shorter (465 min) and blood loss was lower (580 ml) in the sacrifice than in the preserve group (523 min and 815 ml respectively).

CONCLUSION

The HV can be sacrificed safely according to the proposed criteria, reducing surgical invasiveness without influencing the postoperative course.

Prognosis of patients undergoing hepatectomy for solitary hepatocellular carcinoma originating in the caudate lobe

BACKGROUND

Operative and nonoperative treatment for hepatocellular carcinoma (HCC) originating in the caudate lobe is regarded as challenging because of its deep location in the liver and possibly worse prognosis than HCC in other sites in the liver. The objective of this study is to investigate the clinicopathologic factors and survival of patients who underwent hepatectomy for solitary HCC originating in the caudate lobe.

METHODS

A retrospective review of 783 patients who underwent curative hepatectomy for solitary HCC between 1988 was performed. Clinicopathologic factors and survival rate of 46 (5.9%) patients with HCC originating in the caudate lobe were compared with those of 737 (94%) patients with HCC arising in other sites.

RESULTS

The clinical backgrounds of patients with HCC in the caudate lobe and in other sites were comparable. Hepatectomy for HCC in the caudate lobe was associated with greater operative time and blood loss than for HCC in other sites of the liver. Pathologically, HCC in the caudate lobe was associated with less frequent intrahepatic metastasis, lesser operative margins, and more frequent tumor exposure than HCC in other sites. Overall and disease-free 5-year survival rates of the 46 patients with solitary HCC in the caudate lobe were 76% and 45%, respectively; no significant difference was observed in the overall or disease-free survival rates between the 2 groups (P = .07 and P = .77, respectively). Resection of HCC in the paracaval portion of the caudate lobe (n = 27) was associated with more frequent anatomic resection, greater operative time and blood loss, and a lesser operative margin than HCC in the Spiegel lobe or caudate process (n = 19).

CONCLUSION

Resection for HCC in the caudate lobe, especially in the paracaval portion, remains technically demanding. The prognosis of patients with solitary HCC in the caudate lobe, however, was as good as that of patients with solitary HCC in other sites in the liver.

Fetal development of the retrohepatic inferior vena cava and accessory hepatic veins: Re-evaluation of the Alexander Barry's hypothesis

The retrohepatic inferior vena cava (IVC) is commonly considered to originate from the right vitelline or omphalomesenteric vein. In contrast, Alexander Barry hypothesized that one of the hepatic veins grows to merge with the subcardinal vein and develops into the retrohepatic IVC. We re-examined fetal development of the retrohepatic IVC and other related veins using serial histological sections of 20 human fetuses between 6 and 16 weeks of gestation. At 6-7 weeks, when a basic configuration of the portal-hepatic vein systems had just been established, one of hepatic veins (i.e., the posterocaudal vein in the present study) had grown caudally to reach the posterocaudal surface of the liver, and notably, extended into the primitive right adrenal gland (five of the eight early-staged fetuses). Because the inferior right hepatic vein (IRHV) and retrohepatic IVC appeared at the same developmental stage, it is likely that any peripheral remnants of the posterocaudal vein would continue to function as primary drainage territory for the IRHV. The caudate vein developed rapidly in accordance with marked caudal and leftward extension of Spiegel's lobe at 12-16 weeks. Thin accessory hepatic veins developed later than the caudate vein and IRHV. The present results supported Barry's hypothesis.

Surgical techniques according to anatomic variations in living donor liver transplantation using the right lobe

OBJECTIVES

In living donor liver transplantation, the right lobe has many anatomic variations in the vascular tree, which could lead to surgical complications. We need to define surgical technique according to anatomy.

METHODS

From January 2000 to September 2007, 310 living donor liver transplantations using the right lobe were performed in patients with end-stage liver disease. The vascular trees were evaluated preoperatively with computed tomography and magnetic resonance angiography. We classified anatomic points for safe harvest in the hepatic artery, portal vein, and hepatic vein and described technical points based on anatomic variations.

RESULT

There were many anatomic variations in the hepatic vasculature. Hepatic artery variations were observed in 16.8% of cases. Double hepatic artery was observed in 14 cases (4.5%). Of these 14 cases, reconstruction as a single artery was performed in 6 and dual reconstruction was performed in 8 cases. Portal vein variation was observed in 45 cases (14.5%): Dual anastomosis to right and left portal vein was performed in type III (n = 20; 6.4%) and type IV (n = 3; 1.0%) variations. There were 70 cases of portal vein thrombosis. In 8 of the 70, a jump or interposition graft with iliac vein was utilized. Of the middle hepatic vein variant, segment V vein only was reconstructed in 188 (60.6%) cases. In 21 (6.8%) cases, segment VIII vein only was reconstructed, and in 43 (13.9%) cases, both segment V and segment VIII veins were reconstructed using the recipient's portal vein, a cryopreserved iliac vein, or a prosthetic graft. The most common variation of right inferior hepatic vein was type II (n = 141; 45.5%), which has 1 right inferior hepatic vein.

CONCLUSION

Living donor liver transplantation using the right lobe can be performed safely, but there is a potential operative risk because of various anatomic variations. To minimize operative complications, anatomic variations should be kept in mind to ensure a safe and successful operation.

Portal vein complications after adult-to-adult living donor liver transplantation

Successful management of portal vein (PV) complications after liver transplantation is crucial to long-term success. Little information is available, however, regarding the incidence and treatment of PV complications after adult-to-adult living donor liver transplantation (LDLT). Between January 1996 and October 2006, 310 adult LDLTs were performed at our institution. PV thrombus was present in 54 patients at the time of LDLT. The incidence of PV complications, choice of therapeutic intervention, and outcomes were retrospectively analyzed. Among the 310 recipients, PV complications were identified in 28 (9%). Risk factors included smaller graft size, presence of PV thrombus at the time of LDLT, and use of jump or interposition cryo-preserved vein grafts for PV reconstruction. When divided into early (within 3 months, n = 11) and late (after 3 months, n = 17) complications, the use of vein grafts for PV reconstruction predisposed to the occurrence of late, but not early, PV complications. Portal vein thrombosis occurred more frequently in the early period (eight out of 11, 73%), whereas stenosis occurred more frequently in the later period (14 out of 17, 82%). Surgical interventions were favored in the earlier period, whereas interventional radiologic approaches were selected for later events. Overall 3- and 5-year survival rates were 81% and 77%, respectively, in patients with PV complications and 88% and 84%, respectively, in those without PV complications (P = 0.21, log-rank test). PV complications are a significant problem following LDLT with both early and late manifestations. Acceptable long-term results, however, are achievable with periodic ultrasonographic surveillance and timely conventional therapeutic interventions. The use of cryo-preserved vein grafts for reconstructing portal flow should be discouraged.

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.

Subtotal hepatectomy following neoadjuvant chemotherapy for a previously unresectable hepatocellular carcinoma

An awareness of variant hepatic vascular anatomy provides vital information in the preoperative evaluation of patients with hepatocellular carcinoma. The authors present a patient with unresectable hepatocellular carcinoma who responded to combination systemic and regional chemotherapy. Because of the presence of an enlarged inferior right hepatic vein, the patient subsequently underwent successful subtotal hepatectomy with resection of all three main hepatic veins. This case illustrates that the combination of innovative neoadjuvant chemotherapy and well-planned surgical approaches may benefit a small number of patients previously deemed unresectable.

Ultrasonically assisted retrohepatic dissection for a liver hanging maneuver

OBJECTIVE

To establish a safer and technically easier retrohepatic dissection for the liver hanging maneuver with the assistance of intraoperative ultrasound (IOUS).

SUMMARY BACKGROUND DATA

The liver hanging maneuver described by Belghiti et al is an innovative suspending technique of the liver and is useful in difficult major right hepatectomies or in donor operations for living donor liver transplantation. The most important complication of this procedure is injury to the short hepatic veins and subsequent massive bleeding with an incidence of 4% to 6%.

METHODS

After the cranial dissection of the suprahepatic inferior vena cava (IVC) between the middle and left hepatic veins, a long light curved Kelly clamp is inserted from the caudal edge behind the caudate lobe and passed cranially along the anterior midline of the IVC. On the midway of the dissection, the proper hepatic vein draining the caudate lobe (PrCV) is visualized. A safe dissection path is confirmed by IOUS, identifying the position of the clamp tip, PrCV, and the caudal end of the cranial retrohepatic dissection. When IOUS shows that the clamp tip has reached the caudal end of the cranial dissection, the operator can feel the clamp tip with his/her finger and the retrohepatic dissection is completed.

RESULTS

From September 2003 to July 2004, 50 donor operations were performed for adult living donor liver transplantation. Retrohepatic dissection was feasible in 40 cases (80%). Of these, a US-assisted retrohepatic dissection was performed in 34 donors. PrCVs were visualized by IOUS in 48 donors (96%). The location of these PrCVs varied significantly (60 degrees -175 degrees from the right edge of IVC), and there were no distinct landmarks for identifying the location of PrCVs and safe dissecting course (55 degrees -130 degrees ). IOUS found that the dissecting clamp was heading to the PrCV in 3 cases and the direction of dissection was shifted to avoid injury. No substantial bleeding or no other complication related to retrohepatic dissection was encountered in any of the cases.

CONCLUSIONS

With the aid of IOUS, the whole course of the blind dissection between the anterior surface of the IVC and the liver could be clearly visualized. IOUS could also identify the PrCV, the most dangerous point in the retrohepatic dissection.

Tailoring the type of donor hepatectomy for adult living donor liver transplantation

Donor hepatectomies for adult living donor liver transplantations were performed in 200 consecutive donors to harvest a left liver (LL) graft (n = 5), a LL plus caudate lobe (LL + CL) graft (n = 63), a right liver (RL) graft (n = 86), a RL and middle hepatic vein (RL + MHV) graft (n = 28) or a right lateral sector (RLS) graft (n = 18). The graft type was selected so that at least 40% of the recipient's standard liver volume was harvested. No donor deaths occurred, and no significant differences in the morbidity rates among either donors or recipients were observed when the outcomes were stratified according to the graft type. Donors who donated RL exhibited higher values of serum total bilirubin and prothrombin time than those who donated non-RL (LL, LL + CL, RLS) grafts. The time taken for hilar dissection and parenchymal transection increased in the following order: RLS graft, LL graft and RL graft harvesting. In conclusion, non-RL grafting was more time consuming, but the hepatic functional loss in the donors was smaller. Our graft selection criteria were useful for reducing the use of RL grafts with acceptable morbidity in both donors and recipients.

Superior Vena Cava Graft for Right Liver and Right Lateral Sector Transplantation

BACKGROUND

The usefulness of cryopreserved superior vena cava (SVC) grafts for venous reconstruction remains to be evaluated in right liver and right lateral sector transplantation.

METHODS

Reconstruction of the hepatic vein was performed when the congested area in the liver graft was significant. A vein graft with a suitable shape and length meeting the demands for the venoplasty was selected, and SVC grafts were used in 20 recipients. Surgical techniques were classified into five types according to the necessity of middle or short hepatic vein reconstruction in the liver graft. Surgical outcomes and vein graft patency were evaluated.

RESULTS

All 20 recipients survived the operation without any complications caused by congestion. Liver functions were well recovered in the early postoperative period. The 1-year primary patency rates of cryopreserved vein grafts used for reconstructed right hepatic veins, inferior right hepatic veins, and middle hepatic vein tributaries were 100%, 94%, and 42%, respectively.

CONCLUSIONS

SVC grafts were feasible for outflow tract reconstruction in right liver and right lateral sector transplantation, although the long-term patency of the grafts for middle hepatic vein reconstruction remains to be evaluated.

The prevalence and variations of inferior right hepatic veins on contrast-enhanced helical CT scanning

PURPOSE

To present the prevalence and variations of inferior right hepatic veins (IRHVs) on contrast-enhanced helical computed tomography (CEHCT) scans.

MATERIALS AND METHODS

The routine abdominal CEHCT scans of 349 patients were reviewed. Three hundred and eight patients (88.2%) were included in the study. Of the 349 patients, 41 (11.8%) were excluded from the study because of improper opacification of hepatic veins and right hepatic lobe lesions which made difficult the optimal visualization and assessment of IRHVs. The mean age of 308 patients was 43 years (range 3-97 years). One hundred and forty-three patients (46.4%) were men and 165 (53.6%) women. Scans were examined whether the IRHVs were demonstrated or not and classified according to their numbers, levels, diameters, and joinings to inferior vena cava (IVC).

RESULTS

Of the 308 patients, 65 (21.1%) had one or two IRHVs. Fifty-four patients (83.1%) had only one IRHV and 11 (16.9%) patients had two. More than two IRHVs were not seen in any patient. Eight (72.7%) of 11 double IRHVs joined the IVC at the same level and others (27.3%) did not. There was no truncal opening to the IVC. In five patients (7.7%) the IRHV were large (> or =0.5 cm).

CONCLUSION

The presence of IRHVs is common and routine CEHCT scanning is efficacious in assessment of IRHVs.

Segment-oriented approach to liver resection

Segment-oriented liver resection is a distinct surgical approach and represents the virtuosity of hepatic surgery. It is unique in the finesse of its execution and in its oncologic efficacy and safety. The varied combinations of segmentectomy allow greater flexibility and opportunity for liver surgeons to extirpate the equally diverse nature and location of intrahepatic pathologic conditions. The technique promotes tumor clearance while con-serving uninvolved parenchyma.

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.

Limitations and pitfalls of Couinaud's segmentation of the liver in transaxial Imaging

The segmental anatomy of the human liver has become a matter of increasing interest to the radiologist, especially in view of the need for an accurate preoperative localization of focal hepatic lesions. In this review article first an overview of the different classical concepts for delineating segmental and subsegmental anatomy on US, transaxial CT, and MR images is given. Essentially, these procedures are based on Couinaud's concept of three vertical planes that divide the liver into four segments and of a transverse scissura that further subdivides the segments into two subsegments each. In a second part, the limitations of these methods are delineated and discussed with the conclusion that if exact preoperative localization of hepatic lesions is needed, tumor must be located relative to the avascular planes between the different portal territories.

Sling suspension of the liver in donor operation: a gradual tape-repositioning technique

BACKGROUND

To control bleeding in the deeper parenchymal plane in right hepatectomy, Belghiti et al. (J Am Coll Surg 2001;193:109) proposed a liver-hanging maneuver using a sling passed between the anterior surface of the inferior vena cava (IVC) and the liver parenchyma. We applied this technique in donor operations in which a hepatic parenchymal transection should be performed before dividing the feeding or draining vessels for the graft.

METHODS

After passing a tape between the liver and the IVC, the lower tip of the tape is pulled up behind the hepatic hilum to enable effective traction of the dorsal part of the liver. To preserve significant middle hepatic vein (MHV) tributaries in right-liver graft, the tape is gradually repositioned behind the veins, and parenchymal transection is completed before dividing the venous tributaries. Congestion of the graft is minimal until harvest. In right hepatectomy with the MHV, the tape is switched behind the MHV to preserve the MHV.

RESULTS

Since March 2000, this technique has been used in 71 consecutive donor operations, including 37 right hepatectomies without the MHV, 8 right hepatectomies with the MHV, 20 left hepatectomies with the caudate lobe, and 6 right lateral sectorectomies. Taping behind the liver was successful in all but one donor (98.6%). There were no major complications related to this procedure.

CONCLUSIONS

This new approach to the sling suspension of the liver with a gradual tape manipulation facilitated the suspending action and was useful in four types of donor operation. These techniques are feasible in most living donors and are recommended as basic procedures to enhance the safety of the donor and the quality of the graft.

Surgical treatment of Budd-Chiari syndrome

Shunting and transplantation are satisfactory methods of treating Budd-Chiari syndrome (BCS). Selection of treatment is based on the degree of hepatic injury (clinical settings), liver biopsy results, potential for parenchymal recovery, and pressure measurements. Shunting is recommended in cases of preserved hepatic function and architecture. In the presence of fulminant forms of BCS, in cases of established cirrhosis or frank fibrosis, or for patients with defined hepatic metabolic defects (e.g., protein C or protein S deficiency), liver transplantation is the treatment of choice. Nonsurgical alternatives, although encouraging, have limited long-term outcome results at the present time. In most cases of BCS, a thrombophilic disorder can be identified. However, it is important to note that postoperative vascular thrombosis has been identified in patients with BCS who do not have a definable hypercoagulable predisposition. It therefore is our practice to recommend early (<24 hours postoperatively) initiation of intravenous heparin therapy in all patients with BCS, who then undergo life-long anticoagulation with coumadin.

Intraoperative ultrasonography in liver cancer

IOUS has become increasingly important for surgical resection in patients with cirrhosis and healthy liver. IOUS is important in the diagnosis and staging of liver cancer and as an element of the surgical technique, and IOUS can now be considered a fundamental tool for hepatobiliary and other surgical procedures [3]. The American College of Surgeons has recently recognized the need for surgeons to have specific training in ultrasonography. Meanwhile, dedicated monographs on IOUS have been published in the United States, Chile, and Europe [39-42].

The minor hepatic veins: anatomy and classification

A detailed description of the distribution and drainage pattern of the minor hepatic veins is presented in this paper. A classification based on the segmentation of the liver divides these veins into four main groups: 1) veins of Segment I which includes the veins of the caudate lobe and the veins of the caudate process; 2) veins of Segment VI; 3) veins of Segment VII; and 4) veins of Segment IX. A knowledge of the anatomy of the minor hepatic veins becomes more clinically valuable as the number of complex dissections of the retrohepatic areas, hepatectomies. and hepatic transplantations grow.

Technical challenges of hepatic venous outflow reconstruction in right lobe adult living donor liver transplantation

A right lobe graft that is drained by the right hepatic vein (RHV) is obtained by transecting the liver on the right side of the middle hepatic vein (MHV). On occasion, a small RHV that only drains a portion of the right lobe, with the predominant outflow achieved by the MHV, is encountered. If such variation is not recognized while performing right lobe liver transplantation and the RHV only is used for reconstruction, venous outflow obstruction with subsequent graft congestion and eventual graft failure will occur. Additionally, preservation of the main MHV and its branch drainage of the left lobe is crucial to avoid outflow blockage to the remaining segment 4 in the donor. We report 4 cases showing a variant type of small RHV and large MHV branch that drain not only segments 5 and 8, but also segments 6 and 7. These variations were simultaneously associated with a large-caliber inferior RHV that also required reconstruction. The methods used to diagnose such anatomic variations and the techniques for reconstruction in the donor and recipient are described.

Radiologic anatomy of the rabbit liver on hepatic venography, arteriography, portography, and cholangiography

Seo TS, Oh JH, Lee DH, et al. Radiologic anatomy of the rabbit liver on hepatic venography, arteriography, portography, and cholangiography. Invest Radiol 2001;36:186-192.

RATIONALE AND OBJECTIVES

The radiologic anatomy of rabbit liver has received little study but is important in many experimental investigations.

METHODS

Twenty-four rabbits were studied by using hepatic venograms, aortograms, hepatic arteriograms, cholangiograms, and portograms.

RESULTS

In all cases, the right, middle, and left hepatic veins drained into the inferior vena cava just below the diaphragm, and the caudate lobe hepatic vein drained more inferiorly. The proper hepatic artery was a branch of the common hepatic artery in 96%. The first branch of the proper hepatic artery was the caudate lobe artery. The remaining main hepatic artery was divided into the right and left hepatic arteries. The left hepatic artery was further divided into the medial and lateral segmental branches in 95%. The anatomy of the portal vein or bile duct was the same as the hepatic artery in 100% of cases.

CONCLUSIONS

Knowledge of the normal patterns and variations of the vessels and bile duct will be helpful for experiments of the rabbit liver in future studies.

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.