Evaluation of ventral branches of segment VI portal vein relative to the right hepatic vein in laparoscopic right anterior sectionectomy.

INTRODUCTION: The right intersectional plane and the right hepatic hilum were noted too often exhibit anatomical variations, making difficult the laparoscopic right anterior sectionectomy (LRAS). METHODS: We analyzed the anatomical features employing 3D-CT images of 55 patients, and evaluated these features according to the course of ventral branches of segment VI of the portal vein (PV, P6a) relative to the right hepatic vein (RHV). RESULTS: P6a run on the dorsal side of RHV in 32 patients (58%, Dorsal-P6a) and the ventral side of RHV in 23 (42%, Ventral-P6a). Ventral-P6a had more patients with S6 partially drained by middle hepatic vein (MHV, 39% vs. 0%, P < 0001), the narrower angle between the anterior and posterior branches of PV (73.1° vs. 93.8°, P = 0.006), the wider angle between the RHV and inferior vena cava  (54.3° vs. 44.3°, P < 0.001), and more steeply pitched angle between S6 and S7 along the RHV (140.6° vs. 162.0°, P < 0.001) compared to Dorsal-P6a. CONCLUSION: In LRAS for Dorsal-P6a patients, the transection surface was relatively flat. In LRAS for Ventral-P6a patients, the narrow space between anterior and posterior glissons makes difficult the glissonean approach. The transection plane was steeply pitched, and RHV was partially exposed. S6 was often partially drained to MHV in 39% of the Ventral-P6a patients, which triggers congestion during liver transection of a right intersectional plane after first splitting the confluence of this branch.

Application of the "Hand as Foot" teaching method in liver Couinaud segmentation.

OBJECTIVE: We aim to provide a teaching method to better explain the liver Couinaud Segmentation teaching. METHOD: Through a deep understanding of the liver Couinaud Segmentation teaching, and after more than 20 years of teaching practice, our department teaching team pioneered "Hand as Foot ". RESULTS: The combined teaching method of "Hand as Foot" can clearly show the liver Couinaud Segmentation teaching. CONCLUSION: Compared with the traditional teaching method, "Hand as Foot" is favored by most teachers and students.

Quantitative anatomy of the large variant right hepatic vein: A systematic three-dimensional analysis.

Anatomical variations of the right hepatic vein, especially large variant right hepatic veins (≥5 mm), have important clinical implications in liver transplantation and resection. This study aimed to evaluate anatomical variations of the right hepatic vein using quantitative three-dimensional visualization analysis. Computed tomography images of 650 patients were retrospectively analyzed, and three-dimensional visualization was applied using the derived data to analyze large variant right hepatic veins. The proportion of the large variant right hepatic vein was 16.92% (110/650). According to the location and number of the variant right hepatic veins, the configuration of the right hepatic venous system was divided into seven subtypes. The length of the retrohepatic inferior vena cava had a positive correlation with the diameter of the right hepatic vein (rs = 0.266, p = 0.001) and the variant right hepatic veins (rs = 0.211, p = 0.027). The diameter of the right hepatic vein was positively correlated with that of the middle hepatic vein (rs = 0.361, p < 0.001), while it was inversely correlated with that of the variant right hepatic veins (rs = -0.267, p = 0.005). The right hepatic vein diameter was positively correlated with the drainage volume (rs = 0.489, p < 0.001), while the correlation with the variant right hepatic veins drainage volume was negative (rs = -0.460, p < 0.001). The number of the variant right hepatic veins and their relative diameters were positively correlated (p < 0.001). The volume and percentage of the drainage area of the right hepatic vein decreased significantly as the number of the variant right hepatic vein increased (p < 0.001). The findings of this study concerning the variations of the hepatic venous system may be useful for the surgical planning of liver resection or transplantation.

Impact of the inferior vena cava morphology on fluid dynamics of the hepatic veins.

We reported previously that a large vertical interval between the hepatic segment of the inferior vena cava (IVC) and right atrium (RA), referred to as the IVC-RA gap, was associated with more intraoperative bleeding during hemi-hepatectomy. We conducted a computational fluid dynamics (CFD) study to clarify the impact of fluid dynamics resulting from morphologic variations around the liver. The subjects were 10 patients/donors with a large IVC-RA gap and 10 patients/donors with a small IVC-RA gap. Three-dimensional reconstructions of the IVC and hepatic vessels were created from CT images for the CFD study. Median pressure in the middle hepatic vein was significantly higher in the large-gap group than in the small-gap group (P = 0.008). Differences in hepatic vein pressure caused by morphologic variation in the IVC might be one of the mechanisms of intraoperative bleeding from the hepatic veins.

Hepatic venous reconstruction of the left lateral segment with emphasis on anomalous hepatic vein in pediatric liver transplantation.

Left lateral segment grafts have become a suitable option in pediatric liver transplantation (PLT). The correlation between hepatic vein (HV) reconstruction and outcome is relevant when assessing the safe use of these grafts. We retrospectively reviewed the medical records prospectively collected from a pediatric living donor liver transplantation database and conducted a comparative analysis of the different left lateral segment graft types according to HV reconstruction. Donor, recipient, and intraoperative variables were analyzed. Post-transplant outcomes included vascular complications such as hepatic vein outflow obstruction, early (≤30 d) and late (>30 d) PVT, hepatic artery thrombosis, and graft survival. From February 2017 to August 2021, 303 PLTs were performed. According to venous anatomy, the distribution of the left lateral segment was as follows: single HV (type I) in 174 (57.4%), close HVs, simple venoplasty for reconstruction (type II) in 97 (32.01%), anomalous hepatic vein (AHV) with a distance between the HVs orifices that allowed simple venoplasty (type IIIA) in 25 (8.26%) and AHV with a distance between the HVs orifices requiring homologous venous graft interposition (type IIIB) in 07 (2.31%) grafts. Type IIIB grafts came from male donors ( p =0.04) and had a higher mean donor height ( p =0.008), a higher mean graft weight, and a higher graft-to-recipient weight ratio, both p =0.002. The median follow-up time was 41.4 months. The overall cumulative graft survival was 96.3%, and comparative graft survival showed no difference (log-rank p =0.61). No hepatic vein outflow obstructions were observed in this cohort study. There was no statistically significant difference in the post-transplant outcomes between the graft types. The venous reconstruction of the AHV with homologous venous graft interposition had similar outcomes in the short and long term.

Revisión Anatómica de Sistema Venoso Intrahepático. Hematoma Intrahepático Subcapsular en Colecistectomia Laparoscópica / Anatomical Review of Intrahepatic Venous System. Subcapsular Intrahepatic Hematoma In Laparoscopic Cholecystectomy

La aparición del hematoma intrahepático subcapsular (SHI) después de la colecistectomía laparoscópica es una complicación poco frecuente. El estudio anatómico de las venas suprahepáticas nos permitió observar que existen numerosos patrones de ramificación de estos. Presentamos el caso de una mujer de 37 años que, durante la intervención de colecistectomía laparoscópica, se observa en el acto quirúrgico, la formación espontánea de hematomas subcapsulares, secundario a la tracción forzada del fondo del órgano

The appearance of subcapsular intrahepatic hematoma (SHI) after laparoscopic cholecystectomy is an infrequent complication.The anatomical study of the suprahepatic veins allowed us to observe that there are numerous branching patterns of these. We present the case of a 37-year-old female who, during the laparoscopic cholecystectomy intervention, is observed in the surgical act, the spontaneous formation of subcapsular hematomas, secondary to forced traction of the fundus of the organ

Portal and Hepatic Venous Territorial Mapping in Healthy Human Livers: Virtual Three-Dimensional Computed Tomography Size-Shape-Topography Study.

OBJECTIVES: This study aimed to assess portal and hepatic venous volumes as related to the planning of complex liver resections and segmental liver transplant. MATERIALS AND METHODS: We analyzed 3-dimensional computed tomography of portal and hepatic vein territorial maps of 140 potential living related liver donors. Portal and hepatic vein maps were simulated both separately and in overlap (cross-mapping) to calculate inflow and outflow volumes. RESULTS: In total liver volume, the right hemiliver was always dominant (mean 64.7 ± 4.8%) and the right medial sector (mean 36.4 ± 6.8%) and segment 8 (mean 19.1 ± 4.3%) accounted for the largest volumes, whereas the left medial sector(mean 13.5 ± 3.1%) and segment 4A (mean 5.8 ± 1.8%) accounted for the smallest volumes (with exclusion of caudate lobe). The right hepatic vein was dominant for both right hemiliver and right lateral sector and had the largest drainage volume in total liver volume (mean 40.0 ± 11.2%). The left hepatic vein was dominant for both left hemiliver and left lateral sector but had the smallest drainage volume fortotal liver volume (mean 21.3 ± 5.0%). The middle hepatic vein drained 50.2 ± 12.5% of the right medial sector and 75.8 ± 15.4% of the left medial sector. In 67 cases, an accessory vein (inferior hepatic vein) drained 16.5 ± 13.2% ofthe right hemiliver, 31.4 ± 25.1% ofthe right lateral sector, 26.6 ± 23.2% of segment 7, and 37.4 ± 31.3% of segment 6. CONCLUSIONS: The portal and hepatic vein territorial anatomy was characterized by extensive individual variability. An extremely smallremnant volume (<25% of total liver volume) precluded a minority of virtual extended left and a majority of extended right hepatectomies. Left trisectionectomy was associated with risky drainage from the middle hepatic vein, extensive segment 6 remnant congestion volume in 8% of cases, and right lateral sector-favorable inferior hepatic vein large drainage pattern in 13% of livers.

Bases anatómicas y aplicación clínica inicial del abordaje glissoniano intrahepático en las hepatectomías / Anatomical bases and initial clinical application of the intrahepatic Glissonian approach in hepatectomies / Bases anatômicas e aplicação clínica inicial da abordagem glissoniana intra-hepática em hepatectomias

Introducción: El control pedicular durante las resecciones hepáticas puede hacerse mediante disección hiliar extrahepática (DHE) o abordaje glissoniano (AG). El AG intrahepático (AGI) según técnica de Machado puede brindar ciertas ventajas, especialmente en disecciones difíciles. Sin embargo, es menos empleado que la DHE. Objetivo: Analizar las bases anatómicas del AGI y comunicar nuestra experiencia clínica inicial. Material y métodos : El AGI según técnica de Machado se practicó en seis (6) hígados cadavéricos. Luego se hizo la disección hepática para valorar la efectividad del cargado pedicular y medir la profundidad de los diferentes pedículos glissonianos. La aplicación clínica de la técnica fue gradual y selectiva, aplicándola cuando nos parecía factible y que aportaba alguna ventaja sobre la DHE. Resultados: en los 6 hígados cadavéricos fue posible realizar el cargado de todos los pedículos glissonianos (lobares y sectoriales bilateralmente, así como los segmentarios izquierdos). Estos se encuentran a una profundidad menor a 2 cm de la capsula hepática, siendo accesibles para su control mediante AGI. La principal excepción es el pedículo anterior derecho, cuyo nacimiento es más profundo, lo que asociado a su origen en sentido cefálico y a veces ramificado, puede hacer más difícil su cargado. La aplicación del AGI se llevo a cabo en 5 pacientes, en todos fue efectiva, insumió poco tiempo y no tuvo complicaciones intraoperatorias. Conclusiones: el AGI según técnica de Machado es un procedimiento sistematizado, reproducible, factible y seguro, aún en su aplicación clínica inicial. El conocimiento anatómico de los pedículos glissonianos es fundamental para llevarlo a cabo con éxito.

Introduction: Pedicle control during liver resections can be done by extrahepatic hilar dissection (EHD) or the Glissonian approach (GA). Intrahepatic GA (IGA) according to the Machado technique can offer certain advantages, especially in difficult dissections. However, it is used less than the DHE. Objective : to analyze the anatomical bases of the IGA and to communicate our initial clinical experience. Material and methods : IGA according to the Machado technique was performed on six (6) cadaveric livers. Liver dissection was then performed to assess the effectiveness of pedicle loading and measure the depth of the different Glissonian pedicles. The clinical application of the technique was gradual and selective, applying it when it seemed feasible and that it provided some advantage over DUS. Results : in the 6 cadaveric livers it was possible to load all the Glissonian pedicles (lobar and sectoral bilaterally, as well as the left segmental ones). These are found at a depth of less than 2 cm from the hepatic capsule, being accessible for control by IGA. The main exception is the right anterior pedicle, whose origin is deeper, which, associated with its cephalad and sometimes branched origin, can make it more difficult to load. The application of the IGA was carried out in 5 patients, in all of them it was effective, it took little time and there were no intraoperative complications. Conclusions: the IGA according to the Machado technique is a systematic, reproducible, feasible and safe procedure, even in its initial clinical application. The anatomical knowledge of the Glissonian pedicles is essential to carry it out successfully.

Introdução: o controle pedicular durante as ressecções hepáticas pode ser feito por dissecção hilar extra-hepática (DHE) ou abordagem Glissoniana (AG). A AG intra-hepática (AGI) segundo a técnica de Machado pode oferecer algumas vantagens, principalmente em dissecções difíceis. No entanto, é usado menos do que o DHE. Objetivo: Analisar as bases anatômicas da AGI e comunicar nossa experiência clínica inicial. Material e métodos : A AGI segundo a técnica de Machado foi realizada em seis (6) fígados cadavéricos. A dissecção do fígado foi então realizada para avaliar a eficácia da carga pedicular e medir a profundidade dos diferentes pedículos Glissonianos. A aplicação clínica da técnica foi gradativa e seletiva, aplicando-a quando parecia viável e que proporcionava alguma vantagem sobre o USD. Resultados: nos 6 fígados cadavéricos foi possível carregar todos os pedículos Glissonianos (lobares e setoriais bilateralmente, assim como os segmentares esquerdos). Estes são encontrados a menos de 2 cm da cápsula hepática, sendo acessíveis para controle por AGI. A principal exceção é o pedículo anterior direito, cuja origem é mais profunda, o que, associado à sua origem cefálica e por vezes ramificada, pode dificultar o carregamento. A aplicação da AGI foi realizada em 5 pacientes, em todos foi eficaz, em pouco tempo e sem complicações intraoperatórias. Conclusões : AGI segundo a técnica de Machado é um procedimento sistemático, reprodutível, factível e seguro, mesmo em sua aplicação clínica inicial. O conhecimento anatômico dos pedículos Glissonianos é essencial para realizá-lo com sucesso.

Relationship between hepatic venous anatomy and hepatic venous blood loss during hepatectomy.

PURPOSE: Predicting increased blood loss based on anatomical intervascular relationships is essential in major hepatectomy. METHODS: We assessed 63 consecutive patients undergoing anatomical hepatectomy exposing the hepatic vein (HV) trunk at two institutes. Correlations between anatomical alterations of the hepatic inferior vena cava (IVC), HV, hepatic IVC, or right atrium (RA) and the blood loss per standard weight (BLSW) or blood transfusion (n = 18) were analyzed. The results of IVC partial clamping (PC) were additionally examined. RESULTS: The BLSW in type V-up anatomical morphology was significantly higher than that in straight type (p < 0.05). The parameters associated with an increased BLSW (> 13.5 mL/kg) were tumor size (> 4 cm), prothrombin activity (< 87%), CVP (> 7 mmHg), area of suprahepatic IVC (< 360 mm2), IVC-RA gap (> 28 mm), longitudinal angle of IVC (< 160°), and axial angle of the MHV (< 55°). A multivariate analysis revealed that a high IVC-RA gap was a significant independent risk factor (odds ratio; 4.32, p < 0.05). Among 25 patients undergoing IVC-PC, only three showed a remarkable decrease in hepatic venous bleeding. No other statistically significant differences in the surgical records were observed in most cases. CONCLUSION: The IVC-RA gap might be a promising novel predictive parameter reflecting increased blood loss leading to blood transfusion in anatomical hepatectomy.

High-resolution three-dimensional visualization of hepatic sinusoids in cirrhotic rats via serial histological sections.

AIM: As a specialized intraparenchymal vascular conduit, hepatic sinusoids play a key role in liver microcirculation. This study aimed to explore the three-dimensional (3D) morphological changes of cirrhotic sinusoids by serial histological sections. METHODS: Cirrhosis was induced by tail vein injection of albumin in Wistar rats with a positive antibody. A total of 356 serial histological sections were prepared from liver tissue blocks of normal and cirrhotic rats. The optical microscope images were registered and reconstructed, and 3D reconstructions of the fine structures of fibrous tissues and sinusoids were subsequently visualized. RESULTS: The fibrosis area of the cirrhotic sample was 6-16 times that of the normal sample (P<0.001). Cirrhosis led to obvious changes in the distribution and morphology of sinusoids, which were mainly manifested as dilation, increased quantity and disordered distribution. Compared with normal liver, cirrhotic liver has a significantly increased volume ratio, number and volume of sinusoids (1.63-, 0.53-, and 1.75-fold, respectively, P<0.001). Furthermore, the samples were further divided into three zones according to the oxygen supply, and there were significant differences in the morphology of the sinusoids in the normal and cirrhotic samples (P<0.05). In particular, morphological parameters of the cirrhotic sinusoids near the portal area were obviously greater than those in the normal liver (P<0.05). CONCLUSION: 3D morphological structures of hepatic sinusoids were reconstructed, and the adaptive microstructure changes of cirrhotic sinusoids were accurately measured, which has an important implications for the study of hepatic microcirculation and pathological changes of cirrhosis.

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.

Hepatic "hot-spot" on angio-computed tomography: the role of inferior Sappey's and ensiform veins.

Hepatic "hot spots" in anterior paraumbilical hepatic segments of patients suffering from superior vena cava syndrome may be revealed by angio-computed tomography. They may be due to a collateralizing system, the epigastric-paraumbilical venous system (EPVS), which enters the liver as a "third inflow". We report a typical case emphasizing the role of the ensiform and inferior Sappey's veins which constitute typical anatomic components of the EPVS.

Current role of intraoperative ultrasonography in hepatectomy.

Hepatectomy had a high mortality rate in the previous decade because of inadequate techniques, intraoperative blood loss, liver function reserve misdiagnoses, and accompanying postoperative complications. However, the development of several modalities, including intraoperative ultrasonography (IOUS), has made hepatectomy safer. IOUS can provide real-time information regarding the tumor position and vascular anatomy of the portal and hepatic veins. Systematic subsegmentectomy, which leads to improved patient outcomes, can be performed by IOUS in open and laparoscopic hepatectomy. Although three-dimensional (3D) computed tomography and gadoxetic acid-enhanced magnetic resonance imaging have been widely used, IOUS and contrast-enhanced IOUS are important modalities for risk analyses and making decisions regarding resectability and operative procedures because of the vital anatomical information provided and high sensitivity for liver tumors, including "disappearing" liver metastases. Intraoperative color Doppler ultrasonography can be used to delineate the vascular anatomy and evaluate the blood flow volume and velocity in hepatectomy patients and recipients of deceased- and living-donor liver transplantation after vessel reconstruction and liver positioning. For liver surgeons, IOUS is an essential technique to perform highly curative hepatectomy safely, although recent advances have also been made in virtual modalities, such as real-time virtual sonography with 3D visualization.

Study of the human liver by ultrasound examination to search for variations of venous anatomy.

INTRODUCTION: Knowledge about venous patterns (especially portal and hepatic venous) and their variations are extremely crucial for liver transplantation and other surgical procedures on liver. Studies have been done at national or international level on variations of hepatic venous patterns by CT or MRI or by dissection on cadaveric liver. No definitive or authentic study on this topic could be noted in electronic and print media, as well as in standard textbook. Considering low cost and noninvasive nature, we utilized ultrasonography to bridge this lacuna. AIM: To estimate prevalence and types of anatomical variations of hepatic venous system and to determine association of among variations. MATERIALS AND METHODS: It is an observational cross-sectional study where ultrasonographic evaluation of hepatic venous pattern on adult population of either sex (consecutive sampling) without any major liver disorders was done in RG Kar Medical College and data were analyzed with appropriate statistical procedures. RESULTS: Normal hepatic venous pattern along with normal portal venous pattern is much higher in our study, which is a unique finding. The proportion of normal portal venous pattern is more in extra hepatic bifurcation group. Variations of portal vein and normal hepatic venous pattern are more in case of intrahepatic bifurcation of portal venous branching group. Overall presence of intrahepatic bifurcation of portal vein is significantly higher than extrahepatic bifurcation. CONCLUSIONS: This study provides an updated database for the prevalence and distribution of anatomic variations of the hepatic venous and portal venous system.

Re-evaluation of the Couinaud classification for segmental anatomy of the right liver, with particular attention to the relevance of cranio-caudal boundaries.

BACKGROUND: Although the Couinaud classification of liver segments has been challenged by several studies, whether the cranio-caudal boundaries can be delineated in the right liver has not yet been assessed. This study scrutinized the third-order branching pattern of the portal vein in the right liver with attention to the validity of cranio-caudal segmentation. METHODS: Three-dimensional reconstruction of the portal vein and hepatic vein, using non-contrast-enhanced magnetic resonance imaging was performed in 50 healthy participants. RESULTS: In the right paramedian sector, the portal vein ramified into 2 thick P8s (P8vent and P8dor) in all the participants. Additional thick P8s that ran laterally and/or medially (P8lat and/or P8med) were observed in 18 (32%) participants. In contrast, multiple thin P5s, ranging in number from 2 to 6 (median, 4), branched from the right paramedian trunk, the right portal trunk, and/or even from P8s. In the right lateral sector, an arch-like type in which multiple P6s ramified from a single thick P7 was observed in 26 (52%) participants. A bifurcation type composed of a single P7 and a single P6 was observed in 23 (46%) participants, and a trifurcation type was observed in 1 participant. CONCLUSION: No clear cranio-caudal intersegmental plane could be delineated in the right liver in most of the participants. The resection of a whole Couinaud segment in the right liver should not be regarded as a systematic, anatomic resection from an oncologic viewpoint. In contrast, detailed information on the third-order portal vein ramification pattern is likely to be helpful when performing smaller anatomic resections.

Outcomes of transjugular liver biopsies for liver transplant recipients with bicaval and piggyback hepatic vein anastomoses.

BACKGROUND: Liver transplant hepatic venous anastomoses are usually created using "bicaval" or "piggyback" techniques, which may result in unfavorable angulation between the inferior vena cava and hepatic veins, and makes hepatic vein catheterization and tissue sampling during transjugular liver biopsy (TLB) technically challenging. PURPOSE: To compare the technical successes and complications of TLBs for recipients of liver transplants with bicaval and piggyback hepatic vein anastomoses. MATERIAL AND METHODS: Information on type of hepatic vein surgical anastomosis was available for 190 adult patients in whom 306 consecutive TLBs were performed during 2009-2017: 158 with bicaval and 148 with piggyback anastomoses. The primary outcome of procedural success was defined as obtaining a tissue sample sufficient to make a pathologic diagnosis. RESULTS: A technical success rate of 97% with adequate liver tissue for diagnosis was similar between the anastomotic groups (P = 0.50). TLB was unsuccessful in 3% of patients with piggyback anastomoses due to unfavorable hepatic venous anatomy whereas biopsy was successful in all patients with bicaval anastomoses (P = 0.02). Fluoroscopy times were not significantly different (12.1 vs. 13.9 min, P = 0.08). Rates of major complication were similar between the two groups (3% vs. 3%, P > 0.99). CONCLUSION: TLB is safe and effective for liver transplant patients regardless of the type of hepatic vein anastomosis. While failure to catheterize or advance the stiffened biopsy cannula into the hepatic vein is more likely to occur in patients with piggyback anastomoses, this is a rare occurrence.

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.

[Research progression and application of Laennec capsule in liver].

The Laennec capsule of liver was first discovered and reported by French doctor Rene Theophile Hyacinthe Laennec in 1802.However, it has not received enough attention for more than 200 years since then. In recent years, with the rapid development of liver surgery represented by laparoscopic technology, and the deepening of the theory of precise liver surgery, the fine anatomical structure of liver Laennec capsule has returned to the vision of liver surgeons.Recent studies have demonstrated the presence of Laennec capsule in liver histology, covering the whole liver surface, and lining the surface of liver parenchyma around the Glisson pedicle and the main hepatic vein along the inflow and outflow channels of the liver. Based on the Laennec capsule approach, it is expected to unify the current approach of Glisson pedicle and the approach of hepatic vein, and provide a new theoretical basis for the liver surgery, and guide us in the standardization of liver surgeries.

Hepatic vein in living donor liver transplantation.

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