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

3-D reconstruction in liver surgery: a systematic review

BACKGROUND

Three-dimensional reconstruction of the liver offers several advantages to the surgeon before and during liver resection. This review discusses the factors behind the use of liver 3-D reconstruction.

METHODS

Systematic electronic search, according to PRISMA criteria, was performed. A literature search of scientific papers was performed until October 2023. Articles were chosen based on reference to 3-D liver reconstruction and their use in liver surgery. GRADE methodology and the modified Newcastle-Ottawa scale were used to assess the quality of the studies.

RESULTS

The research included 47 articles and 7724 patients were analyzed. Preoperative planning was performed with 3-D liver reconstruction in the 87.2% of the studies. Most of preoperative 3-D liver reconstructions were performed in the planning of complex or major hepatectomies. Complex hepatectomies were performed in 64.3% patients. The 55.3% of the studies reported an improved navigation and accuracy during liver resection. Four studies (8.6%) on living donor liver transplant (LDLT) concluded that 3-D liver reconstruction is useful for graft selection and vascular preservation. Nine papers (19.1%) reported an accurate measurement of future liver remnant.

CONCLUSION

Liver 3-D reconstruction helps surgeons in the planning of liver surgery, especially in liver graft and complex liver resections, increasing the accuracy of the surgical resection.

The Role of Three-Dimensional Modeling to Improve Comprehension of Liver Anatomy and Tumor Characteristics for Medical Students and Surgical Residents

OBJECTIVE

Studying liver anatomy can be challenging for medical students and surgical residents due to its complexity. Three-dimensional visualization technology (3DVT) allows for a clearer and more precise view of liver anatomy. We sought to assess how 3DVT can assist students and surgical residents comprehend liver anatomy.

DESIGN

Data from 5 patients who underwent liver resection for malignancy at our institution between September 2020 and April 2022 were retrospectively reviewed and selected following consensus among the investigators. Participants were required to complete an online survey to investigate their understanding of tumor characteristics and vascular variations based on patients' computed tomography (CT) and 3DVT.

SETTING

The study was carried out at the General and Hepato-Biliary Surgery Department of the University of Verona.

PARTICIPANTS

Among 32 participants, 13 (40.6%) were medical students, and 19 (59.4%) were surgical residents.

RESULTS

Among 5 patients with intrahepatic lesions, 4 patients (80.0%) had at least 1 vascular variation. Participants identified number and location of lesions more correctly when evaluating the 3DVT (84.6% and 80.9%, respectively) compared with CT scans (61.1% and 64.8%, respectively) (both p ≤ 0.001). The identification of any vascular variations was more challenging using the CT scans, with only 50.6% of correct answers compared with 3DVT (72.2%) (p < 0.001). Compared with CT scans, 3DVT led to a 23.5%, 16.1%, and 21.6% increase in the correct definition of number and location of lesions, and vascular variations, respectively. 3DVT allowed for a decrease of 50.8 seconds (95% CI 23.6-78.0) in the time needed to answer the questions. All participants agreed on the usefulness of 3DVT in hepatobiliary surgery.

CONCLUSIONS

The 3DVT facilitated a more precise preoperative understanding of liver anatomy, tumor location and characteristics.

Efficacy of Extended Modification in Left Hemihepatectomy for Advanced Perihilar Cholangiocarcinoma: Comparison Between H12345'8'-B-MHV and H1234-B

OBJECTIVE

The aim of this study was to verify the prognostic impact of the tumor exposure at the liver transection margin (LTM) in left-sided perihilar cholangiocarcinoma and the impact of middle hepatic vein (MHV) resection on this exposure.

BACKGROUND

In perihilar cholangiocarcinoma, tumors are unexpectedly exposed at the LTM during left hemihepatectomy (LH).

METHODS

Patients who underwent LH for perihilar cholangiocarcinoma during 2002 to 2018 were retrospectively evaluated. LH was classified into conventional and extended types, which preserved and resected the MHVs, respectively. Positive LTM was defined as the involvement of invasive carcinoma at the liver transection plane and/or the adjacent Glissonean pedicle exposed. The clinicopathologic features and survival outcomes were compared between procedures.

RESULTS

Among 236 patients, conventional and extended LHs were performed in 198 and 38 patients, respectively. The LTM was positive in 31 (13%) patients, with an incidence of 14% versus 8% ( P = 0.432) and 24% versus 0% in advanced tumors ( P = 0.011). Tumor size ≥ 18 mm ( P = 0.041), portal vein invasion ( P = 0.009), and conventional LH ( P = 0.028) independently predicted positive LTM. In patients with negative LTM, the survival was comparable between the two groups: 60.4% versus 59.2% at 3 years ( P = 0.206), which surpassed 17.7% for those with positive LTM in the conventional group ( P < 0.001). Multivariable analysis demonstrated that LTM status was an independent prognostic factor ( P = 0.009) along with ductal margin status ( P = 0.030).

CONCLUSIONS

The LTM status is an important prognostic factor in perihilar cholangiocarcinoma. Extended LH reduced the risk of tumor exposure at the LTM with a subsequent improvement in the survival, particularly in advanced tumors.

Hyper accuracy three-dimensional (HA3D™) technology for planning complex liver resections: a preliminary single center experience

Three-dimensional visualization technology (3DVT) has been recently introduced to achieve a precise preoperative planning of liver surgery. The aim of this observational study was to assess the accuracy of 3DVT for complex liver resections. 3DVT with hyper accuracy three-dimensional (HA3D™) technology was introduced at our institution on February 2020. Anatomical characteristics were collected from two-dimensional imaging (2DI) and 3DVT, while intraoperative and postoperative outcomes were recorded prospectively. A total of 62 patients were enrolled into the study. 3DVT was able to study tumor extension and liver anatomy, identifying at least one vascular variation in 37 patients (59.7%). Future remnant liver volume (FRLV) was measured using 2DI and 3DVT. The paired samples t test assessed positive correlation between the two methods (p < 0.001). At least one vessel was suspected to be invaded by the tumor in 8 (15.7%) 2DI cases vs 16 (31.4%) 3DVT cases, respectively. During surgery, vascular invasion was detected in 17 patients (33.3%). A total of 73 surgical procedures were proposed basing on 2DI, including 2 alternatives for 16 patients. After 3DVT, the previously planned procedure was changed in 15 cases (29.4%), due to the clearer information provided. A total of 51 patients (82%) underwent surgery. The most frequent procedure was right hepatectomy (33.3%), followed by left hepatectomy (23.5%) and left trisectionectomy (13.7%). Vascular resection and reconstruction were performed in 10 patients (19.6%) and portal vein was resected in more than half of these cases (66.7%). 3DVT leads to a more detailed and tailored approach to complex liver surgery, improving surgeons' knowledge of liver anatomy and accuracy of liver resection.

The proximity of the middle hepatic vein to the hepatic hilus: a retrospective radiological study

PURPOSE

The middle hepatic vein (MHV) is an important landmark in anatomical hemihepatectomy. The proximity between the MHV and the hilar plate was suspected to be associated with tumor exposure during left hemihepatectomy for advanced perihilar cholangiocarcinoma and is reported to facilitate a dorsal approach to the MHV during laparoscopic hemihepatectomy. However, the precise distance between these locations is unknown.

METHODS

To investigate the "accurate and normal" distance between the MHV and the hilar plate, the present study focused on patients who presented without perihilar tumor. One hundred and sixty-eight consecutive patients who underwent pancreatoduodenectomy were included. Retrospective radiological measurement was performed using preoperative multi-detector row CT. The optimized CT slices perpendicular to the MHV were made using the multiplanar reconstruction technique. The shortest distance between the MHV and the hilar plate was measured on the left and right sides on the perpendicular slices. The diameters of the left and right hepatic ducts were also measured.

RESULTS

The distance was 9.0 mm (1.9-20.0 mm) on the left side and 11.3 mm (2.3-21.8) on the right side (p < 0.001). The distance on the left side was < 10 mm in 60% of patients (n = 100). Only one-third of patients (n = 55) had a distance of ≥ 10 mm on both sides. As the hepatic ducts became more dilated, the distance from the MHV to the hilar plate became shorter.

CONCLUSION

The MHV was located in close proximity to the hepatic hilus, especially on the left side.

Surgery

This chapter provides a comprehensive background from basic to applied knowledge of surgical anatomy which is necessary for the surgical treatment of cholangiocarcinoma (CCA) patients. Significant advances that have been made in the surgical treatment of CCA were examined. For instance, in-depth details are provided for appropriate preoperative assessment and treatment to optimize patient status and to improve the outcome of surgical treatment(s). Comprehensive details are provided for the surgical techniques and outcomes of treatments for each type of CCA with clear illustrations and images. This chapter also describes the role of minimally invasive surgery and liver transplantation in CCA treatment.

[Transplantation technologies in pediatric liver resections]

Liver resections with transplantation technologies have been recognized as safe procedures for the last decades. These procedures may be the only curative option or alternative to liver transplantation in some cases. Moreover, these surgeries can also provide parenchyma-sparing liver resection. Nevertheless, higher postoperative morbidity and mortality compared to traditional hepatectomy require careful research of indications for liver resections with transplantation technologies, the role of vascular liver exclusion, methods of vascular reconstructions with or without anticoagulation. These challenges are more important for pediatric surgery due to few literature data on this issue. This review is devoted to liver resections with transplantation technologies.

Anatomical Study of the Hepatic Veins in Segment 4 of the Liver Using Three-Dimensional Visualization

Objective: The current study aimed to examine the anatomical structure of the hepatic vein of segment IV liver (S4) of the liver using three-dimensional (3D) visualization technology in order to explore the surgical value of the middle hepatic vein (MHV) manipulation and highlight the importance of current research in hepatic surgery. Methods: Between January 2014 and December 2019, 52 patients with abdominal diseases(not including hepatic disease) were selected for multiphasic computed tomography-enhanced scans of the upper abdomen. A 3D visualization system was utilized to display the structural details of the hepatic veins in S4 of their livers. Couinaud's eight-segment classification system was used to denote the liver' sections. Results: The constructed 3D model clearly displayed vascular morphological characteristics and their location in the liver, hepatic artery and vein system, and portal vein system. Of the 52 patients, 43 had an umbilical fissure vein (UFV) (82.7%), 19 had an accessory S4 liver vein (36.5%), 16 had both a UFV (30.8%) and an accessory S4 liver vein, and 6 had neither (11.5%). A total of 79% of the patients with a UFV and 74.2% of those with an accessory S4 liver vein had venous blood returning into the left hepatic vein. Conclusion: 3D visualization technology was used to determine hepatic venous return of S4 hepatic veins and was found to improve the safety of evaluation in hepatic surgery.

The feasibility of medial segment graft in pediatric liver transplantation revisited by three-dimensional printing

BACKGROUND

The medial segment as a mono-segmental graft was proposed to increase the donor pool for pediatric liver transplantation, but to date, there has been no published case. This study aims to revisit the feasibility of procuring the medial segment graft (MSG) by three-dimensional (3D) printing and ex vivo procedures performed on explanted diseased livers to overcome the gap between theory and clinical implementation.

METHODS

From October 2004 to December 2016, we retrospectively analyzed preoperative computed tomography, magnetic resonance cholangiopancreatography, and intraoperative cholangiography images of our previous live liver donors and identified the indicated anatomy for the MSG, then materialized by 3D printing models to simulate the engraftment. Furthermore, we practiced the procurement procedures on selected explanted diseased livers.

RESULTS

Among 291 analyzed livers, 96 livers (33%) met the arterial criteria for MSG, and two-thirds of them had ideal portal branches for reconstruction. The proposed right border of the MSG was the Cantlie's line, and the left edge was the right side of the umbilical fissure. The mean estimated volume of the MSG was 234 ± 54 ml. Besides, we suggest implanting the MSG as an auxiliary partial graft in an inverted vertical position or a standalone graft with right-side rotation in the right subphrenic space.

CONCLUSION

The procurement of the MSG is feasible based on our results. However, due to the novelty of the procedure, we suggest that the first attempted case of MSG should be implanted as an auxiliary partial graft to maximize patient safety.

LEVEL OF EVIDENCE

Type of study: Case series with no comparison groups EVIDENCE LEVEL: Level IV.

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.

Umbilical fissure vein, anatomical variation and potential surgical application

BACKGROUND

The umbilical fissure vein (UFV) is a hepatic vein that travels within the umbilical fissure (or its proximity), providing venous drainage for hepatic segments 3 and 4. Its preservation carries a potential importance in extended right hemi-hepatectomy, left lateral segmentectomy and extended segment 2 resections.

METHODS

Consecutive 1-mm slice thickness portovenous phase intravenous contrast computed tomography (CT) scans of the abdomen performed were retrospectively reviewed during the period of June 2019 to July 2019, with two independent investigators investigating the presence of UFV, its course, insertion and relation to the umbilical fissure.

RESULTS

A total of 244 CTs were identified and 186 included. The UFV was identified on 72.8% of participants, 109 (81.4%) drained into the main left hepatic vein, while the remaining ones drained either from the main middle hepatic vein (16.4%) or the bifurcation between main left and middle hepatic vein (2.2%). The veins course lay 2 mm or less along the length of umbilical fissure in 39.5%, while 57.5% ran within 1 cm along the length of the umbilical fissure.

CONCLUSION

Pre-operative identification of UFV could assist in operative planning. The vein can be used as a landmark in surgery and should be preserved in left lateral segmentectomy and extended right hepatectomy to avoid parenchymal congestion of remnant segments.

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.

Outcomes of surgery for giant hepatic hemangioma

BACKGROUND

The surgical indications for liver hemangioma remain unclear.

METHODS

Data from 152 patients with hepatic hemangioma who underwent hepatectomy between 2004 and 2019 were retrospectively reviewed. We analyzed characteristics including tumor size, surgical parameters, and variables associated with Kasabach-Merritt syndrome and compared the outcomes of laparoscopic and open hepatectomy. Here, we describe surgical techniques for giant hepatic hemangioma and report on two meaningful cases.

RESULTS

Most (63.8%) patients with hepatic hemangioma were asymptomatic. Most (86.4%) tumors from patients with Kasabach-Merritt syndrome were larger than 15 cm. Enucleation (30.9%), sectionectomy (28.9%), hemihepatectomy (25.7%), and the removal of more than half of the liver (14.5%) were performed through open (87.5%) and laparoscopic (12.5%) approaches. Laparoscopic hepatectomy is associated with an operative time, estimated blood loss, and major morbidity and mortality rate similar to those of open hepatectomy, but a shorter length of stay. 3D image reconstruction is an alternative for diagnosis and surgical planning for partial hepatectomy.

CONCLUSION

The main indication for surgery is giant (> 10 cm) liver hemangioma, with or without symptoms. Laparoscopic hepatectomy was an effective option for hepatic hemangioma treatment. For extremely giant hemangiomas, 3D image reconstruction was indispensable. Hepatectomy should be performed by experienced hepatic surgeons.

Perceptions of porta-celiac vascular models for hepatic surgery and their use in residency training

BACKGROUND

Primary aspect of hepatic navigation surgery is the identification of source vascular details to preserve healthy liver which has a vascular anatomy quite challenging for the young surgeons. The purpose was to determine whether three-dimensional (3D) vascular pattern models of preoperative computed tomography (CT) images will assist resident-level trainees for hepatic surgery.

METHODS

This study was based on the perception of residents who were presented with 5 different hepatic source vascular patterns and required to compare their perception level of CT, and 1:1 models in terms of importance of variability, differential of patterns and preoperative planning.

RESULTS

All residents agree that models provided better understanding of vascular source and improved preplanning. Five stations provided qualitative assessment with results showing the usefulness of porta-celiac models when used as anatomical tools in preplanning (p = 0.04), simulation of interventional procedures (p = 0.02), surgical education (p = 0.01). None of the cases had scored less than 8.5. Responses related to understanding variations were significantly higher in the perception of the 3D model in all cases, furthermore 3D models were more useful for seniors in more complex cases 3 and 5. Some open-ended answers: "The 3D model can completely change the operation plan" One of the major factors for anatomical resection of liver transplantation is the positional relationship between the hepatic arteries and the portal veins.

CONCLUSION

The plastic-like material presenting the hepatic vascularity enables the visualization of the origin, pattern, shape, and angle of the branches with appropriate spatial perception thus making it well-structured.

Inferior Vena Cava and Venous Outflow Reconstruction in Living Donor Liver Transplantation in Children: A Single-Center Retrospective Study and Literature Review

Background

In this report, we present technical problems and solutions used in the reconstruction of the inferior vena cava and graft venous outflow during living donor liver transplantation (LDLT) in children.

Material/Methods

In 65 grafts out of 379 liver transplantations from living donors, reconstruction of multiple hepatic venous branches and/or IVC was necessary. In 4 cases, cryopreserved deceased donor venous grafts were used for the reconstruction of the IVC and/or HV.

Results

Follow-up ranged from 2 months to 17.8 years (median 7.2 years). In 4 children, liver re-transplantation was required for a reason not related to venous outflow (biliary complications in 3 patients, graft insufficiency caused by small-for-size syndrome). Two patients died: 1 due to tumor recurrence and 1 due to multi-organ failure. Fifty-nine patients are alive with good liver function. One patient (1.5%) after deceased donor venous graft reconstruction showed symptoms of venous outflow obstruction, which was successfully treated with endovascular balloon angioplasty and stent placement. The remaining 59 transplanted patients do not show any signs of venous outflow obstruction.

Conclusions

In most cases, the reconstruction of multiple hepatic veins of living donor allografts can successfully be done with local venoplasty, while using cold-stored vein grafts may be helpful in selected cases of LDLT.

Simulation and navigation liver surgery: an update after 2,000 virtual hepatectomies

The advent of preoperative 3-dimensional (3D) simulation software has made a variety of unprecedented surgical simulations possible. Since 2004, we have performed more than 2,000 preoperative simulations in the University of Tokyo Hospital, and they have enabled us to obtain a great deal of information, such as the detailed shape of liver segments, the precise volume of each segment, and the volume of hepatic venous drainage areas. As a result, we have been able to perform more aggressive and complicated surgery safely. The next step is to create a navigation system that will accurately reproduce the preoperative plan. Real-time virtual sonography (RVS) is a navigation system that provides fusion images of ultrasonography and reconstructed computed tomography images or magnetic resonance images. The RVS system facilitates the surgeon's understanding of interpretation of ultrasound images and the detection of tumors that are difficult to find by ultrasound alone. In the near future, surgical navigation systems may evolve to the point where they will be able to inform surgeons intraoperatively in real time about not only intrahepatic structures, such as vessels and tumors, but also the portal territory, hepatic vein drainage areas, and resection lines that have been planned preoperatively.

Venous hepatic segmentation in dogs (Canis lupus familiaris-L. 1758)

The external shape of the liver is varied and determines specific vascular arrangements. This morphological relationship is important to establish hepatic segmentation in different species submitted to surgeries that aim to preserve a larger area of liver parenchyma. After observing 60 livers injected with Neoprene Latex and three plastic moulds obtained by corrosion, eight hepatic venous segments were identified, drained by six hepatic veins agrouped into segmental veins, which drained one sector (segments I, VI, VII and VIII) and intersegmental veins, which drained more than one sector (segments II/III and IV/V). They were described as follows: left intersegmental vein, formed by a segmental vein from the papillary process (segment I), two to three lateral left segmental veins that drained the segment II, and one to five left paramedian segmental veins that drained the segment III; sagittal intersegmental vein, formed by the confluence between segmental vein of the quadrate lobe (segment IV) and the medial right paramedian segmental vein, which derived from the segment V; lateral right paramedian vein drained the dorsocranial sector of the segment VI; the lateral right segmental vein, formed by one to four vessels that drained segment VII, and the segmental vein of the caudate process, which drained the segment VIII. Understanding the number and disposition of the hepatic veins in lobate livers is essential to reduce bleeding risks in surgeries. The nomenclature based on segmentation analogy of non-lobate liver could be less confusing and, therefore, be more useful in the surgical approaches of lobate livers.

Venous drainage of the left liver: an evaluation of anatomical variants and their clinical relevance

AIM

To evaluate the variations in venous drainage from the left liver.

MATERIALS AND METHODS

A retrospective evaluation was performed of all consecutive abdominal computed tomography (CT) examinations at a tertiary referral facility between 1 January and 30 June 2018. Osirix (Pixmeo SARL, Bernex, Switzerland) was used to examine the major hepatic veins and their tributaries in each scan. The classification of variants as proposed by Nakamura and Tsuzuki was used to describe the findings. The following information was collected: ramification pattern, number, length and diameter of middle (MHV) and left (LHV) hepatic vein tributaries. Two researchers collected data independently, and the average measurements were used as the final dimensions.

RESULTS

Of 102 examinations evaluated, only 27 demonstrated the conventional venous drainage patterns. The LHV and MHV combined to form a common trunk that emptied into the inferior vena cava (IVC) in 75 (73.5%) cases. The common trunk had a mean length of 8.89 mm and mean diameter of 20.18 mm. Other patterns included Nakamura and Tsuzuki type I (27.5%), type II (29.4%) and type III variants (16.7%). In addition, 4.9% of patients had absent superior middle veins and 80% had supernumerary short hepatic veins (4%).

CONCLUSION

Only 26.5% of patients in this population had conventional venous drainage from the left liver. Surgeons and radiologists in hepatobiliary practice should be aware of these variants in order to minimise morbidity when performing invasive procedures.

Laparoscopic Central Bisectionectomy Including Resection of the Segment 7 Using the Extrahepatic Glissonean Approach and Hepatic Vein Guidance

BACKGROUND

Certain variations in liver anatomy can aid in parenchymal-preserving hepatectomy.1,2 Inferior right hepatic vein (IRHV) is an accessory vein in the right side of liver draining segment 6.2 We present a case of 67-year-old man with HBV cirrhosis. One HCC in segment 7 abutting the right hepatic vein (RHV) and another large HCC in segment 8/4a were found. After two sessions of TACE, liver resection was scheduled. Resection of RHV was inevitable to get free margin. Fortunately, a significant IRHV was present, so we could preserve segment 6. Central bisectionectomy with segment 7 resection using the Glissonean pedicle approach, and hepatic vein guided transection was planned.3 METHODS: After placement of trocars, pneumoperitoneum was created. The main surgical steps were: (1) Right anterior Glissonean pedicle control; (2) Parenchymal transection along the umbilical fissure; (3) Transection of the right anterior portal pedicle, middle, and right hepatic vein; (4) Parenchymal transection between segments 5 and 6; and (5) Identification of IRHV and resection of segment 7.

RESULTS

The operative time was 330 min, and estimated blood loss was 80 mL. The total intermittent inflow occlusion time was 90 min. The histopathologic diagnosis was well-differentiated HCC. The tumors size of segments 8 and 7 was 4 cm and 2.9 cm, respectively. The resection margin was negative. The patient was discharged uneventfully on postoperative day 5.

CONCLUSIONS

The preserved liver parenchyma after hepatectomy demands good vascular inflow and outflow. A large IRHV could be adequate outflow of segment 6, allowing more distinct operations.

Parenchyma sparing multicomponent liver resection strategy for multiple bilobar synchronous colorectal cancer metastasis

A two-stage multicomponent parenchymal sparing surgical strategy (anatomical extended on left hepatic vein 2-nd segment liver resection and R1vascular approach) allows the successful resection of synchronous multiple bilobar CRC metastases.

Vascular Anomalies of the Pediatric Liver

The liver is a unique organ as it receives afferent blood supply from the umbilical vein, portal vein, and hepatic artery in the developing embryo but has only one efferent drainage method, through the hepatic veins. In the postnatal period, about 70% of the afferent blood flow into the liver is from the portal venous system, unique vessels that begin and end in a capillary system. Vascular anomalies of the hepatic artery, hepatic veins, portal vein, and/or umbilical vein can be congenital or acquired secondary to inflammation and/or infection, trauma, systemic disorders, or iatrogenic causes. The vascular anomalies can be incidental findings at imaging, or the infant or child can present with symptoms such as abdominal pain and ascites, be diagnosed with gastrointestinal bleeding, and have abnormal liver function test results. Imaging can demonstrate vascular findings such as shunts, thrombosis, or collaterals; secondary parenchymal findings such as diffuse or focal abnormal enhancement patterns; and parenchymal lesions such as regenerative nodules. This article discusses and illustrates vascular disorders of the liver that may be encountered in the pediatric population. These include (a) normal vascular variants; (b) congenital anomalies (preduodenal portal vein and infradiaphragmatic total anomalous pulmonary venous return); (c) acquired thromboses (extrahepatic portal venous thrombosis); (d) inflammatory vascular conditions, which can result in hepatic artery aneurysms or pseudoaneurysms; (e) hepatic venous outflow disorders (veno-occlusive disease); and shunt lesions. Liver transplantation and associated vascular complications are a large topic and will not be reviewed in this article. Knowledge of the vascular and parenchymal changes seen with these entities can aid imaging diagnosis and guide appropriate management. ^©RSNA, 2019.

Hepatic vein embolization after portal vein embolization to induce additional liver hypertrophy in patients with metastatic colorectal carcinoma

OBJECTIVES

To assess the effect of salvage hepatic vein embolization (HVE) on the volume of the future liver remnant (FLR) for patients with metastatic colorectal cancer (mCRC) and inadequate hypertrophy following initial portal vein embolization (PVE).

METHODS

From April 2011 to October 2018, 9 patients with mCRC underwent HVE following PVE. The right or middle hepatic vein was embolized with coils and/or vascular plugs. Liver volumes were calculated at baseline, following PVE, and following HVE, in order to assess the hypertrophic effect of PVE and HVE on the FLR.

RESULTS

Nine patients underwent HVE (n = 3, right HVE; n = 6, middle HVE) because of inadequate FLR hypertrophy following PVE. The standardized FLR increased from 0.16 (median, range 0.08-0.24) at baseline to 0.22 (median, range 0.13-0.29) following PVE (p = 0.0005) to 0.26 (median, range 0.19-0.37) following HVE (p = 0.0050). HVE was performed 40 days (median, range 19-128 days) following PVE, and assessment of FLR hypertrophy was performed 41 days (median, range 19-92 days) following HVE. Four of nine patients underwent hepatectomy; 5 patients failed to undergo hepatectomy (n = 3, inadequate hypertrophy; n = 1, disease progression; n = 1, portal hypertension). One patient required repeat HVE due to a patent accessory vein.

CONCLUSIONS

Salvage HVE is an effective technique to induce additional FLR hypertrophy in patients with mCRC and inadequate FLR after initial PVE.

KEY POINTS

• Hepatic vein embolization is effective to induce additional liver hypertrophy in surgical patients with metastatic colorectal carcinoma and inadequate hypertrophy after portal vein embolization. • Increases in future liver remnant volume are feasible in patients who receive hepatotoxic neoadjuvant systemic therapy for metastatic colorectal carcinoma. • Sequential portal vein embolization and hepatic vein embolization can be a viable technique to induce liver hypertrophy in patients with small baseline future liver remnant volumes (< 20%).

Successful use of the left portal vein as graft for middle hepatic vein reconstruction in left hemihepatectomy: preliminary experience on six cases

BACKGROUND

The purpose of this research was to assess the feasibility of reconstructing the middle hepatic vein (MHV) with resected left portal vein during left hemihepatectomy.

METHODS

From January 2014 to January 2018, six patients received left hemihepatectomy combined with MHV reconstruction using the resected left portal vein in West China Hospital. We reviewed the clinical data including patient details, surgical technique, graft patency, and operative results.

RESULTS

All six patients underwent left hemihepatectomy for liver tumors located at left hepatocaval confluence. In these patients, MHV was resected due to tumor invading and reconstructed using the resected left portal vein as graft. The mean operating time was 316 min. Two patients developed complications: one experienced bile leakage and one experienced pleural effusion. No patient developed vascular graft complications. All the grafts remained unobstructed, and no local tumor recurrence occurred during the observation period of 13-41 months.

CONCLUSIONS

Our results indicated that the left portal vein was a safe graft for hepatic vein reconstruction. In addition, left hemihepatectomy combined with middle hepatic vein resection and reconstruction using the left portal vein can be performed safely to treat liver tumors located at hepatocaval confluence.

How Has Virtual Hepatectomy Changed the Practice of Liver Surgery?: Experience of 1194 Virtual Hepatectomy Before Liver Resection and Living Donor Liver Transplantation

OBJECTIVE

To assess how virtual hepatectomy (VH), conducted using surgical planning software, influences the outcomes of liver surgery.

BACKGROUND

Imaging technology visualizes the territories of the liver vessels, which were previously impossible. However, the clinical impact of VH has not been evaluated.

METHODS

From 2004 to 2013, we performed 1194 VHs preoperatively. Outcomes of living donor liver transplantation (LDLT) and hepatectomy for hepatocellular carcinoma (HCC)/colorectal liver metastases (CRLM) were compared between patients in whom VH was performed (VH) and those without VH evaluation (non-VH).

RESULTS

In LDLT, the rate of right liver graft use was higher in the VH (62.1%) than in the non-VH (46.5%) (P < 0.01), which did not increase morbidity of donor surgery. Duration of recipient surgery in the VH in which middle hepatic vein branch reconstruction was skipped was shorter than that in the VH with venous reconstruction. Among HCC patients with impaired liver function, portal territory-oriented resection was conducted more often in the VH than in the non-VH. The 5-year disease-free survival rate for localized HCC was higher in the VH than in the non-VH (37.2% vs 23.9%; P = 0.04). In CRLM, long-term outcomes were similar in the VH and non-VH despite the larger tumor load in the VH.

CONCLUSIONS

VH in LDLT allows double equipoise for the recipient and donor by optimizing decision-making on graft selection and venous reconstruction. VH offers a chance for radical hepatectomy even in HCC patients with impaired liver function and CRLM patients with advanced tumors, without compromising survival.

Impact of three-dimensional visualization technology on surgical strategies in complex hepatic cancer

Surgical resection is still the mainstay of treatment for primary liver cancer (PLC). It is unclear whether three-dimensional visualization (3DV) preoperative evaluation and simulated liver resection would affect the surgical strategies and improve the R0 resection rates of patients with complex PLC when compared with the 2D evaluation using computed tomography or magnetic resonance imaging. In the study, patients with complex PLC who were subjected to laparotomy underwent both 2D and 3DV evaluation before operation. A comparison between the 2D and 3DV evaluation was compared with the gold standard of laparotomy findings. In this study, of 335 patients with complex PLC, 71 were assessed to have resectable tumors. 2D and 3DV assessments determined 63 and 71 patients to have resectable PLC, respectively. At laparotomy 69 of the 71 patients were found to have resectable PLC, but 2 patients were found to be unresectable because of detection of metastatic lesions on laparotomy, which were not detected either by 2D or 3DV preoperative evaluation. The accuracy, false positive and false negative rates of the 2D and the 3DV preoperative assessments in determining tumor resectability were 85.9%, 2.8%, 11.3%, and 97.2% (p < 0.05), 2.8%, 0%, respectively. The 3DV and 2D preoperative evaluation revealed 17 and 13 patients with vascular anomalies, respectively. There were 4 patients with major vascular anomalies not detected by 2D evaluation, whose surgical strategies were modified by 3DV evaluation. These results suggested 3DV preoperative assessment could lead to better in evaluating tumor resectability, with potential benefit in the modification of surgical strategy for patients with complex PLC.

The influence of the middle hepatic vein and its impact on outcomes in right lobe living donor liver transplantation

BACKGROUND

In adult right lobe living donor liver transplantation, the decision to include the middle hepatic vein (MHV) remains controversial.

METHODS

A retrospective analysis of 50 R-LDLTs between January 2008 and June 2016 was performed.

RESULTS

Twenty-one procedures were performed using a MHV+ graft (42.0%) and 29 procedures using a MHV- graft (58%). MHV- donors were taller (173 vs 166 cm, p = 0.004) with a larger standard liver volume (1351 vs 1245 mls, p = 0.014) compared to MHV+ donors. The duration of operation for donors was significantly longer in the MHV+ group (530 (313-975) mins) compared to the MHV- group (489 (336-708) mins) (p = 0.029). Similarly, the operative time for recipients was longer in the MHV+ group (660 (428-831) mins) compared to MHV- (579 (359-1214) mins) (p = 0.023). MHV- grafts were heavier compared to MHV+ grafts (918 vs 711 g, p = 0.017). Recipient mortality rates and Kaplan-Meier survival analysis were comparable (p = 0.411). All donors were well at last review.

CONCLUSION

Both MHV+ and MHV- grafts are safe for the donor and recipient. The decision to take the MHV should be based on specific donor-recipient characteristics.

Impact of the Inferior Right Hepatic Veins on Right Liver Lobe Regeneration in Living-Donor Liver Transplant: 3-Dimensional Computed Tomography Scan Analyses in Donors and Recipients

OBJECTIVES

The presence of an inferior right hepatic vein significantly modifies the outflow pattern of the right liver and may have an impact on graft regeneration.

MATERIALS AND METHODS

Study patients were donors and recipients with 3-dimensional computed tomography scan simulation. We studied the physiologic impact of the inferior right hepatic veins on right liver regeneration in donors of left lobe grafts (step1; n = 60 patients) and the efficacy of a inferior right hepatic vein reconstruction policy based on a vessel caliber > 5 mm criteria in recipients of right liver grafts (step 2; n = 38 patients).

RESULTS

In step 1, the regeneration rate at 1 month was comparable between future liver remnants with inferior right hepatic vein (regeneration rate of 28.3%) and without inferior right hepatic vein (regeneration rate of 30.2%). In step 2, at 3 months after living-donor liver transplant, we observed no significant differences in regeneration rates among grafts anatomically without an inferior right hepatic vein (regeneration rate of 60.7%), grafts with an inferior right hepatic vein but no reconstruction (regeneration rate of 64.9%), and grafts with an inferior right hepatic vein and its reconstruction (regeneration rate of 68.1%). Within the latter subgroup, grafts with a dominant inferior right hepatic vein showed a greater regeneration of the anterior sector with inversion of the anterior-to-posterior sector regeneration ratio compared with right hepatic vein-dominant grafts (inferior right hepatic vein-dominant vs right hepatic vein-dominant showed anterior sector regeneration rates of 85.7% vs 52.1%; P = .02; anterior/posterior sector regeneration ratio was 2.3 vs 0.6, respectively; P = .04).

CONCLUSIONS

The reconstruction policy for inferior right hepatic vein with caliber > 5 mm is effective but should be implemented with computed tomography scan simulation. Right lobe grafts with a dominant inferior right hepatic vein are at higher risk of impaired regeneration due to expected large volumes of hepatic venous congestion if the middle hepatic veins tributaries or the inferior right hepatic veins are not reconstructed and an increased rate of right hepatic vein complications.

Comparison of Patients With and Without Anterior Sector Venous Drainage in Right Lobe Liver Transplantation From Live Donors in Terms of Complications, Rejections, and Graft Survival: Single-Center Experience

AIM

The issue of performing an anastomosis of the anterior sector veins to the vena cava in living donor liver transplantation is still controversial. We aimed to research whether there was any difference in terms of complications, rejections, and graft survival between patients with and without anterior sector venous drainage to the vena cava.

PATIENTS AND METHODS

Patients were retrospectively investigated for demographic data and ratio of graft needed to available graft weight. Donors had volumetric calculations and middle hepatic vein anterior sector drainage documented in detail.

RESULTS

Seventy-three donors with middle hepatic vein drainage were included. Thirty-five had anterior sector venous drainage performed and 38 patients did not have drainage procedures performed. The incidence of general complications was higher in the group without anterior sector drainage (78.3% and P = .002). Biloma linked to bile leaks were observed in 8 patients without drainage (72.8%) and 3 patients with drainage (27.2%). Late acute rejection occurring during follow up after transplantation was identified in 28 patients (11.6%). Of these, 1 (14.3%) had anterior sector drainage and 6 (85.7%) were in the patient group without drainage (P = .067).

CONCLUSION

As a result of this study, for patients with grafts at the volume limit (graft weight to receiver weight ratio <0.8) and with congestion observed in the anterior sector after liver implantation and for patients with outflow problems identified on Doppler ultrasonography, anterior sector veins >5 mm should definitely be drained into the vena cava. Hence, both complication and rejection rates will reduce, and we can lengthen the graft, and thus patient, survival.

Conceptual framework of middle hepatic vein anatomy as a roadmap for safe right hepatectomy

BACKGROUND

While the middle hepatic vein (MHV) guides parenchymal transection during right hepatectomy, its most proximal tributaries can be difficult to identify, and injury to its tributaries can be a source of major bleeding.

METHOD

Following simulation modeling of right hepatectomy, reconstructed MHV data was pooled from 40 patients. MHV-tributaries and MHV-relationship to the portal pedicle were mapped out to facilitate their identification from the beginning of parenchymal transection.

RESULTS

Hotspots for injury were identified: A median of 1 (1-3) tributaries draining segment 5 (V5) were within 45-90mm from the MHV termination, and 16mm above and 22mm caudal to the portal trunk. Simulation demonstrated a constant anatomic relationship between portal pedicle and the proximal MHV. A median of 2 (0-4) tributaries draining segment 8 (V8) were located 9-35mm from the MHV termination. This information was compiled into an "MHV-road-map" demonstrating 86% of the MHV tributaries at risk for significant bleeding are within 15mm of the MHV, while only thin tributaries are located in the outer area.

CONCLUSIONS

The MHV-road-map led to a peripheral-to-central parenchymal transection approach to minimize the risk of MHV-injury thereby reducing bleeding during open and minimally invasive right hepatectomy.

Readdressing the Middle Hepatic Vein in Right Lobe Liver Donation: Triangle of Safety

For equipoising donor safety and optimal recipient outcomes, we adopted an algorithmic "triangle of safety" approach to retrieve 3 types of right lobe liver grafts (RLGs), namely, the modified extended right lobe graft (MERLG), the partial right lobe graft (PRLG), and the modified right lobe graft (MRLG). Reconstruction to achieve a single wide anterior sector outflow was ensured in all patients. We present donor and recipient outcomes based on our approach in 665 right lobe (RL) living donor liver transplantations (LDLTs) performed from January 2013 to August 2015. There were 347 patients who received a MERLG, 117 who received a PRLG, and 201 who received a MRLG. A right lobe graft (RLG) with a middle hepatic vein was retrieved only in 3 out of 18 donors with steatosis >10%. Cold ischemia time was significantly more and remnant volume was less in the MRLG group. Of the donors, 29.3% had complications (26% Clavien-Dindo grade I, II) with no statistically significant difference among the groups. The Model for End-Stage Liver Disease score was higher in the MERLG group. There were 34 out of 39 with a graft-to-recipient weight ratio (GRWR) of <0.7% who received a MERLG with inflow modulation. Out of 4 patients who developed small-for-size syndrome in this group, 2 died. The 90-day patient survival rate was similar among different GRWRs and types of RLG. In conclusion, a selective and tailored approach for RL donor hepatectomy based on optimal functional volume and metabolic demands not only addresses the key issue of double equipoise in LDLT but also creates a safe path for extending the limits.

Segment 5 parenchymal sparing in extended left hepatectomy with respect to venous outflow-is it a feasible procedure?

BACKGROUND

Segment 5 (S5) sparing liver resection for cases that require an anatomic left trisectionectomy has not been reported yet. The authors intended to verify the outcome of S5-sparing extended left hepatectomy (ELH) in respect to venous outflow.

METHODS

All adult patients who underwent S5-sparing ELH between 2012 and 2017 in authors' institute have been enrolled in this study. S5-sparring ELH was defined as resection of S2, S3, S4, and S8 with or without S1. The surgery planning was based on the images from two-dimensional triphasic computed tomography and/or magnetic resonance imaging. A three-dimensional image reconstruction and liver volumetric study were performed retrospectively.

RESULTS

Out of 177 cases of major hepatic resection, only seven non-hilar cholangiocarcinoma patients underwent ELH during the study period. S5-sparing ELH was performed to five patients, in whom no tumor involvement in S5. The venous outflow of S5 has been maintained intraoperative, and S5 congestion has not been observed in all patients. Tailored management of the S5 venous outflow ensured an increase in functional remnant liver volume by 52.8% (range, 25.6 to 66.9%) by sparing of S5. A negative resection margin was achieved in all patients. One patient had postoperative bile leak requiring reoperation. No posthepatectomy liver failure (PHLF) has been observed.

CONCLUSION

S5-sparing ELH is technically feasible. Under the tailored management of S5 venous outflow, the functional future liver remnant can be increased. Further studies with larger sample size are needed to evaluate which circumstances the liver segment 5 could be preserved without venous reconstruction during the left extended hepatectomy.

Human liver segments: role of cryptic liver lobes and vascular physiology in the development of liver veins and left-right asymmetry

Couinaud based his well-known subdivision of the liver into (surgical) segments on the branching order of portal veins and the location of hepatic veins. However, both segment boundaries and number remain controversial due to an incomplete understanding of the role of liver lobes and vascular physiology on hepatic venous development. Human embryonic livers (5-10 weeks of development) were visualized with Amira 3D-reconstruction and Cinema 4D-remodeling software. Starting at 5 weeks, the portal and umbilical veins sprouted portal-vein branches that, at 6.5 weeks, had been pruned to 3 main branches in the right hemi-liver, whereas all (>10) persisted in the left hemi-liver. The asymmetric branching pattern of the umbilical vein resembled that of a "distributing" vessel, whereas the more symmetric branching of the portal trunk resembled a "delivering" vessel. At 6 weeks, 3-4 main hepatic-vein outlets drained into the inferior caval vein, of which that draining the caudate lobe formed the intrahepatic portion of the caval vein. More peripherally, 5-6 major tributaries drained both dorsolateral regions and the left and right ventromedial regions, implying a "crypto-lobar" distribution. Lobar boundaries, even in non-lobated human livers, and functional vascular requirements account for the predictable topography and branching pattern of the liver veins, respectively.