Laparoscopic Liver Tunnel for Tumors at the Hepatocaval Confluence.

BACKGROUND: Tumors at the hepatocaval confluence can be treated with parenchyma-sparing surgery, also with minimally invasive approach.1,2 The "Liver Tunnel" was described for tumors involving the paracaval portion of Sg1 in contact or infiltrating the middle hepatic vein (MHV).3 A "Liver Tunnel" with laparoscopic approach is proposed. METHODS: A 48-year-old woman was referred for three synchronous colorectal liver metastases in the paracaval portion of Sg1 in contact with the inferior vena cava and the MHV, in Sg8 ventral and in Sg6, after an urgent left laparoscopic hemicolectomy for an obstructing carcinoma. A laparoscopic Sg1 resection extended to Sg8 ventral were planned after neoadjuvant chemotherapy. Estimated future liver remnant (FLR) was 75% (840 ml) of healthy liver (Fig. 1). In case of right hepatectomy extended to Sg1, estimated FLR was 25% (280 ml) of healthy liver. Fig. 1 3D reconstruction and intraoperative images of Liver Tunnel (A) and Sg6 resection (B). Total liver volume: 1110 ml. Total resected liver volume 270 ml: Liver Tunnel 93 ml; Sg6 177 ml. Liver volumes were measured with HA3D™ technology with Medics3D software (Medics3D, Turin, Italy) RESULTS: Pneumoperitoneum is established, and four operative ports are placed. Sg1 is approached from the left, dividing the Glissonean pedicles and short hepatic veins. MHV is approached cranio-caudally from the dorsal side. The resection continues on the ventral side, according to our "Ultrasound Liver Map technique" with a cranio-caudal approach to the MHV.4 Sg8 ventral pedicles are divided and the resection completed with aid of indocyanine green negative staining. A Sg6 resection is then performed. Operative time was 480 min. Blood loss was 100 ml. The postoperative course was uneventful, and the patient was discharged on fourth postoperative day. The two parenchyma-sparing resections saved an estimated volume of 75% (840 ml) of healthy liver (Fig. 1). The estimated remnant liver volume after a right hepatectomy extended to Sg1 would have been only 25%. CONCLUSIONS: Tumors at the hepatocaval confluence involving Sg1 can be removed with the "Liver Tunnel," which can be performed with minimally invasive approach. The "Laparoscopic Liver Tunnel" pushes further the limit of minimally invasive parenchyma-sparing surgery for ill-located tumors with complex vascular relationship.

Liver Resection Under Total Hepatic Vascular Exclusion with In Situ Hypothermic Isolated Hepatic Perfusion for Advanced Liver Tumors.

PURPOSE: Continuous dissection or simultaneous reconstruction of the hepatic vein (HV) and inferior vena cava (IVC) was achieved under total hepatic vascular exclusion (THVE) with in situ hypothermic isolated hepatic perfusion (HIHP) in two cases. CASE 1: The patient previously underwent liver resections with the right HV for colorectal liver metastasis (CRLM). This time, the CRLM had invaded the left HV and IVC, and five courses of FOLFILI plus ramucirumab were given, resulting in stable disease. Due to expected high HV pressure, liver parenchymal transection was started under THVE. Sub-segmentectomy with patch graft plasty of the IVC and reconstruction of the left HV using a jugular vein graft were performed under THVE and HIHP. This patient died at home 3 months after surgery; the cause of death was unknown. CASE 2: Hepatocellular carcinoma in the caudate lobe was in extensive contact with the roots of three main HVs and the IVC, and pressed the hepatocaval confluence, with high HV pressure expected. In addition, tumor thrombosis extended to both the main portal vein and the common bile duct, resulting in the inability to introduce chemotherapy. After tumor thrombectomy, liver parenchymal transection was started under THVE. Extended left hepatectomy with wedge resection, and primary suture of the right HV and IVC was performed under THVE and HIHP. Recurrence-free and overall survivals were 8 months (lung metastasis) and 31 months, respectively. CONCLUSIONS: In liver resection for liver tumors located in the hepatocaval confluence, THVE with HIHP is useful for ensuring the safety.

Pure Laparoscopic Anatomic Resection of Liver Segment 4 with Middle Hepatic Vein Involvement Using Indocyanine Green Fluorescence Staining.

BACKGROUND: Laparoscopic anatomic resection of liver segment 4 is a technically challenging operation, which is rarely reported owing to the difficulty of defining the demarcation of a hepatic segment 4 on a monitor.1 The portal territory staining method is technically feasible to identify tumors and segment boundaries during hepatectomy.2 Herein, we describe the laparoscopic hepatectomy of segment 4 using the fluorescent-positive staining method. METHODS: A 72-year-old man recurred colorectal liver metastases after colectomy, positron emission tomography (PET)/computed tomography (CT) showed metastases located in segment 4 with involvement of the middle hepatic vein (MHV) and caudate lobe; no other organ metastasis or recurrence occurred. We performed an anatomical hepatectomy 4 with MHV and parenchymal resection of segment 1 (H1'/4-MHV).3 The key point of the procedure was dividing and clamping Glisson's branches for segment 2 and segment 3 using the hepatic round ligament approach; the G2 and G3 were dissected along the right side of round ligament via the extrahepatic Glissonian approach, then the left hepatic artery (LHA) was divided and injected with ICG in the left portal vein (LPV). Finally, transection was performed along the fluorescent stain location line and ischemic demarcation line. RESULTS: The operation time was 263 min; the Pringle lasted 110 min, and the estimated blood loss was 400 g. The patient was discharged on postoperative day 5 without complications. Sigmoid carcinoma and R0 margin were confirmed by histopathology. CONCLUSIONS: Laparoscopic anatomic hepatectomy 4 with middle hepatic vein invasion using indocyanine green (ICG) fluorescence staining is a feasible and effective technique.

Combination of a Glissonean Approach and Indocyanine Green Fluorescence Imaging to Perform a Laparoscopic Right Anterior Sectionectomy.

BACKGROUND: Laparoscopic right anterior sectionectomy (LRAS) remains a technically demanding procedure as it requires two transection planes where the middle and right hepatic veins run; however, the main difficulty is locating these two planes1-3. The aim of this video was to show the technique of an LRAS performed with a transparenchymal glissonean pedicle approach and guided by indocyanine green (ICG) staining. METHODS: This was the case of an 80-year-old man with a history of hemochromatosis and normal liver function. He was diagnosed with a 6 cm hepatocellular carcinoma (HCC) located at segment 8, close to the right anterior pedicle. RESULTS: The technique consisted of parenchymal transection along the main portal fissure along the right border of the middle hepatic vein. Opening the liver facilitated access to the right anterior glissonean pedicle and selective transparenchymal clamping. A negative-stain ICG test permitted to demarcate the transection line along the right lateral portal fissure. The parenchymal transection was carried out in a caudal approach, along two perfectly marked planes, preserving the middle and right hepatic veins. The duration of the procedure was 200 min and blood loss was 300 mL. Postoperative course was uneventful and the patient was discharged on the third postoperative day. CONCLUSION: Guidance during resection, and protection of the right posterior pedicle and right hepatic vein are the key points of the LRAS. The glissonean approach and the ICG imaging technology are of great help in resolving these difficulties.

Novel Use of the Falciform Ligament for MHV Reconstruction During Laparoscopic Hepatectomy of Colorectal Liver Metastasis.

BACKGROUND: Laparoscopic hepatectomy (LH) with oncological R0 resection combined with systemic therapy offers the best chance of cure for colorectal liver metastasis. However, tumors in vicinity of major hepatic veins require complex technique. Parenchyma-sparing resection with involved vein resection and peritoneal patch reconstruction could be an efficacious alternative to preserve liver volume for adjuvant chemotherapy and avoid venous congestion of the remnant liver.1,2 METHODS: A 64-year-old female, with history of colon cancer, had new diagnosis of liver metastatic tumor of S8 (2.8 cm), which was considering encroached on middle hepatic vein (MHV) with distal part patent. Thus margin-negative, parenchyma-sparing liver resection with involved vein resection and proximal MHV reconstruction was indicated for oncological radicality. RESULTS: With the patient in modified French position, we dissected falciform ligament and right coronary ligament to expose the crypt between right hepatic vein (RHV) and MHV. Intraoperative ultrasound localized the tumor and resection margin. Parenchymal dissection was performed caudally to cranially, left to right, to ligate dorsal branch of G8 (G8d) and V8 and expose main trunk of MHV. The involved side-wall of MHV was incised after the proximal and distal parts clamped. Peritoneal patch was harvested from falciform ligament to repair MHV side-wall before clamps released. The patient had an uneventful recovery and remained disease-free at 1 year postoperatively with patency of distal MHV by image. CONCLUSIONS: LH with MHV reconstruction by falciform ligament for metastatic lesion is technically demanding but feasible with oncological radicality and volume preservation for adjuvant chemotherapy.

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.

Liver regeneration after portal and hepatic vein embolization improves overall survival compared with portal vein embolization alone: mid-term survival analysis of the multicentre DRAGON 0 cohort.

BACKGROUND: The purpose of this study was to compare 3-year overall survival after simultaneous portal (PVE) and hepatic vein (HVE) embolization versus PVE alone in patients undergoing liver resection for primary and secondary cancers of the liver. METHODS: In this multicentre retrospective study, all DRAGON 0 centres provided 3-year follow-up data for all patients who had PVE/HVE or PVE, and were included in DRAGON 0 between 2016 and 2019. Kaplan-Meier analysis was undertaken to assess 3-year overall and recurrence/progression-free survival. Factors affecting survival were evaluated using univariable and multivariable Cox regression analyses. RESULTS: In total, 199 patients were included from 7 centres, of whom 39 underwent PVE/HVE and 160 PVE alone. Groups differed in median age (P = 0.008). As reported previously, PVE/HVE resulted in a significantly higher resection rate than PVE alone (92 versus 68%; P = 0.007). Three-year overall survival was significantly higher in the PVE/HVE group (median survival not reached after 36 months versus 20 months after PVE; P = 0.004). Univariable and multivariable analyses identified PVE/HVE as an independent predictor of survival (univariable HR 0.46, 95% c.i. 0.27 to 0.76; P = 0.003). CONCLUSION: Overall survival after PVE/HVE is substantially longer than that after PVE alone in patients with primary and secondary liver tumours.

Pediatric Hepatoblastoma After Neoadjuvant Chemotherapy: Diagnostic Performance of MR in Staging POSTTEXT and Vascular Involvement.

BACKGROUND: The assessment of resectability after neoadjuvant chemotherapy of hepatoblastoma is dependent on Post-Treatment EXTENT of Disease (POSTTEXT) staging and its annotation factors P (portal venous involvement) and V (hepatic venous/inferior vena cava [IVC] involvement), but MR performance in assessing them remains unclear. PURPOSE: To assess the diagnostic performance of contrast-enhanced MR imaging for preoperative POSTTEXT staging and diagnosing vascular involvement in terms of annotation factors P and V in pediatric hepatoblastoma following neoadjuvant chemotherapy. STUDY TYPE: Retrospective. SUBJECTS: Thirty-five consecutive patients (17 males, median age, 24 months; age range, 6-98 months) with proven hepatoblastoma underwent preoperative MR imaging following neoadjuvant chemotherapy. FIELD STRENGTH/SEQUENCE: 3.0 T; T2-weighted imaging (T2WI), T2WI with fat suppression, diffusion weighted imaging, radial stack-of-the-star/Cartesian 3D Dixon T1-weighted gradient echo imaging. ASSESSMENT: Three radiologists independently assessed the POSTTEXT stages and annotation factors P and V based on the 2017 PRE/POSTTEXT system. The sensitivities and specificities were calculated for 1) diagnosing each POSTTEXT stage; 2) discrimination of stages III and IV (advanced) from those stages I and II (non-advanced) hepatoblastomas; and 3) annotation factors P and V. The combination of pathologic findings and surgical records served as the reference standard. STATISTICAL TESTS: Sensitivity, specificity, Fleiss kappa test. RESULTS: The sensitivity and specificity ranges for discriminating advanced from non-advanced hepatoblastomas were 73.3%-80.0% and 80.0%-90.0%, respectively. For annotation factor P, they were 66.7%-100.0% and 90.6%, respectively. For factor V, they were 75.0% and 67.7%-83.9%, respectively. There was excellent, substantial, and moderate agreement on POSTTEXT staging (Fleiss kappa = 0.82), factors P (Fleiss kappa = 0.64), and factors V (Fleiss kappa = 0.60), respectively. DATA CONCLUSION: MR POSTTEXT provides reliable discrimination between advanced and non-advanced tumors, and MR has moderate to excellent specificity at identifying portal venous and hepatic venous/IVC involvement. EVIDENCE LEVEL: 3 TECHNICAL EFFICACY: Stage 3.

Adrenal Vein Sampling: Tips and Tricks.

Adrenal vein sampling (AVS) is the standard method for distinguishing unilateral from bilateral sources of autonomous aldosterone production in patients with primary aldosteronism. This procedure has been performed at limited specialized centers due to its technical complexity. With recent advances in imaging technology and knowledge of adrenal vein anatomy in parallel with the development of adjunctive techniques, AVS has become easier to perform, even at nonspecialized centers. Although rare, anatomic variants of the adrenal veins can cause sampling failure or misinterpretation of the sampling results. The inferior accessory hepatic vein and the inferior emissary vein are useful anatomic landmarks for right adrenal vein cannulation, which is the most difficult and crucial step in AVS. Meticulous assessment of adrenal vein anatomy on multidetector CT images and the use of a catheter suitable for the anatomy are crucial for adrenal vein cannulation. Adjunctive techniques such as intraprocedural cortisol assay, cone-beam CT, and coaxial guidewire-catheter techniques are useful tools to confirm right adrenal vein cannulation or to troubleshoot difficult blood sampling. Interventional radiologists should be involved in interpreting the sampling results because technical factors may affect the results. In rare instances, bilateral adrenal suppression, in which aldosterone-to-cortisol ratios of both adrenal glands are lower than that of the inferior vena cava, can be encountered. Repeat sampling may be necessary in this situation. Collaboration with endocrinology and laboratory medicine services is of great importance to optimize the quality of the samples and for smooth and successful operation. ©RSNA, 2024 Test Your Knowledge questions for this article are available in the supplemental material.

Wedged hepatic vein portovenography for assessment of Rex vein patency in children with extrahepatic portal venous obstruction.

BACKGROUND: Meso-Rex bypass is the surgical intervention of choice for children with extrahepatic portal vein obstruction (EHPVO). Patency of Rex vein, umbilical recessus of the portal vein, is a prerequisite for this surgery. Conventional diagnostic modalities poorly detect patency, while transjugular wedged hepatic vein portography (WHVP) accurately detects patency in 90%. OBJECTIVES: We aimed to assess Rex vein patency and portal vein branching pattern in children with EHPVO using transjugular WHVP and to identify factors associated with Rex vein patency. METHODS: Transjugular WHVP was performed in 31 children with EHPVO by selective cannulation of left and right hepatic veins. Rex vein patency, type of intrahepatic portal venous anatomy (Types A-E), and factors associated with patency of Rex vein were studied. RESULTS: The patency of Rex recess on transjugular WHVP was 29%. Complete obliteration of intrahepatic portal venous radicles was the commonest pattern (Type E, 38.7%) while Type A, the favorable anatomy for meso-Rex bypass, was seen in only 12.9%. Patency of the Rex vein, but not the anatomical pattern, was associated with younger age at evaluation (patent Rex: 6.6 ± 4.9 years vs. nonpatent Rex: 12.7 ± 3.9 years, p = 0.001). Under-5-year children had a 12 times greater chance of having a patent Rex vein (odds ratio: 12.22, 95% confidence interval: 1.65-90.40, p = 0.004). Patency or pattern was unrelated to local factors like umbilical vein catheterization, systemic thrombophilia, or disease severity. CONCLUSION: Less than one-third of our pediatric EHPVO patients have a patent Rex vein. Younger age at evaluation is significantly associated with Rex vein patency.

Pediatric living donor liver transplant for Budd-Chiari syndrome using a cryopreserved pulmonary vein graft for retro-hepatic vena cava reconstruction: A case report.

INTRODUCTION: In pediatric patients with Budd-Chiari syndrome (BCS), living donor liver transplantation (LDLT) raises substantial challenges regarding IVC reconstruction. CASE PRESENTATION: We present a case of an 8-year-old girl with BCS caused by myeloproliferative syndrome with JAK2 V617F mutation. She had a complete thrombosis of the inferior vena cava (IVC) with multiple collaterals, developing a Budd-Chiari syndrome. She underwent LDLT with IVC reconstruction with a cryopreserved pulmonary vein graft obtained from a provincial biobank. The living donor underwent a laparoscopic-assisted left lateral hepatectomy. The reconstruction of the vena cava took place on the back table and the liver was implanted en bloc with the reconstructed IVC in the recipient. Anticoagulation was immediately restarted after the surgery because of her pro-thrombotic state. Her postoperative course was complicated by a biliary anastomotic leak and an infected biloma. The patient recovered progressively and remained well on outpatient clinic follow-up 32 weeks after the procedure. CONCLUSION: IVC reconstruction using a cryopreserved pulmonary vein graft is a valid option during LDLT for pediatric patients with BCS where reconstruction of the IVC entails considerable challenges. Early referral to a pediatric liver transplant facility with a multidisciplinary team is also important in the management of pediatric patients with BCS.

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.

Caudo-dorsal approach combined with the occlusion of right hepatic vein and Pringle maneuver in laparoscopic anatomical resection of segment 7.

BACKGROUND: Laparoscopic anatomical resection of segment 7 (LARS7) remains a technically challenging procedure due to the deep anatomical location and the potential risk of injury to the right hepatic vein (RHV). Herein, we initiated an innovative technique of caudo-dorsal approach combined with the occlusion of the RHV and Pringle maneuver for LARS7 and presented the outcomes of our initial series. METHOD: Since January 2021, the patients who underwent LARS7 by using this novel technique were enrolled in this study. The critical aspect of this technique was the interruption of communication between the RHV and the inferior vena cava. Meanwhile, the Pringle maneuver was adopted to control the hepatic inflow. RESULT: A total of 11 patients underwent LARS7 by using this novel technique, which included 8 hepatocellular carcinoma, 2 bile duct adenocarcinoma and one focal nodular hyperplasia. The median operative time was 199 min (range of 151-318 min) and the median blood loss was 150 ml (range of 50-200 ml). The main trunk of the RHV was fully exposed on the cutting surface in all cases and no patient received perioperative blood transfusion. No procedure was converted to open surgery. Of note, no indications of CO2 gas embolism were observed in these cases after the introduction of double occlusion. Only one patient suffered from postoperative complications and healed after treatment. The median postoperative stay was 5 days (range of 4-7 days). The 90-day mortality was nil. At a median follow-up period of 19 months, all of the patients were alive without any evidence of tumor recurrence. CONCLUSION: The caudo-dorsal approach combined with the occlusion of RHV and the Pringle maneuver may be a feasible and expected technique for safe exposure of RHV in LARS7. Further validation of the feasibility and efficacy of this technique is needed.

Laparoscopic dissection of the first and second porta hepatis along Laennec's capsule via "Hepatic Serosal Incision" approach: How I do it.

To provide a standardized approach for laparoscopic access to dissection of the first and second porta hepatis. By opening a portion of the hepatic serosa and subsequently exposing the hepatic Laennec's capsule, dissection of the first and second porta hepatis was performed along the Laennec's capsule. Utilizing the "Hepatic Serosal Incision" approach along the Laennec's capsule enabled the precise dissection of the left and right hepatic pedicles of the first porta hepatis and the root of the hepatic veins at the second porta hepatis under laparoscopy. This method allows for rapid and accurate access to the space between Laennec's capsule and the hepatic hilar plate system under laparoscopy as well as clear exposure of the root of the hepatic veins and their branches, facilitating more precise laparoscopic anatomical liver resection.

Liver resection with two-step vascular exclusion, in situ hypothermic portal perfusion for the treatment of end-stage hepatic alveolar echinococcosis.

PURPOSE: To evaluate the safety and efficacy of two-step vascular exclusion and in situ hypothermic portal perfusion in patients with end-stage hepatic hydatidosis. METHODS: This study involved patients with advanced hepatic hydatid disease undergoing surgical treatment between 2022 and 2023, which included resection and reconstruction of the hepatic veins, inferior vena cava (IVC), and portal vein (PV). We described the technical details of liver resection and vascular reconstruction, as well as the use of two-step vascular exclusion and in situ hypothermic portal perfusion techniques during the vascular reconstruction process. RESULT: We included 7 patients with advanced hepatic hydatid disease who underwent surgical resection using two-step vascular exclusion and in situ hypothermic portal perfusion. The mean duration of surgery was 12.5 h (range, 7.5-15.0 h). The average hepatic ischemia time was 45 min (range, 25-77 min), while the occlusion time of the IVC was 87 min (range, 72-105 min). The total blood loss was 1000 milliliters (range, 500-1250 milliliters). Postoperatively, patients exhibited good recovery of liver and renal function. The mean ICU stay was 2 days (range, 1-3 days), and the mean postoperative hospital stay was 13 days (range, 9-16 days), with no Grade III or above complications observed during a mean follow-up period of 15 months (range, 9-24 months), CONCLUSION: two-step vascular exclusion and in situ hypothermic portal perfusion for surgical resection of end-stage hepatic hydatid disease is safe and effective. This significantly reduces the anhepatic time.

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.

Venous reconstruction using a round ligament-covered prosthetic vascular graft in right­lobe living­donor liver transplantation: a technical report.

PURPOSE: To evaluate the short term-outcomes of venous reconstruction using a round ligament-covered prosthetic vascular graft and assess its effectiveness in the prevention of prosthetic vascular graft migration in right­lobe living donor liver transplantation (LDLT). METHODS AND RESULTS: Thirty patients underwent reconstruction of the middle hepatic vein (MHV) tributaries during right lobe LDLT between January, 2021 and October, 2022. These patients were divided into the autologous vascular graft group (A group, n = 24) and the round ligament-covered prosthetic vascular graft group (RP group, n = 6). The computed tomography (CT) density ratio of the drainage area in the posterior segment of patent grafts was significantly higher in the RP group than in the A group (0.91 vs. 1.06, p = 0.0025). However, the patency rates of reconstructed MHV tributaries in the A and RP groups were 61% and 67%, respectively, with no significant difference between the groups (p = 0.72). Prosthetic vascular graft migration did not occur in the RP group. CONCLUSION: Venous reconstruction using round ligament-covered prosthetic vascular grafts is a feasible and simple method to prevent prosthetic vascular graft migration in right-lobe LDLT.

Feasibility of venous cuff using an open round ligament or inferior mesenteric vein around the hepatic vein for a left lobe graft in living-donor liver transplantation.

Living-donor liver transplantation (LDLT) is an established treatment for patients with end-stage liver disease or acute liver failure, and outflow reconstruction is considered one of the most vital techniques in LDLT. To date, many strategies have been reported to prevent outflow obstruction, which can be refractory to liver dysfunction and can cause life-threatening graft loss or mortality. In addition, in this era of laparoscopic hepatectomy in donor surgery, especially LDLT using a left liver graft, it has been predicted that cutting the hepatic vein with automatic linear staplers will lead to more outflow-related problems than with conventional open hepatectomy because of the short neck of the anastomosis orifice. We herein review 10 cases of venoplasty performed with a novel venous cuff system using a donor's round ligament around the hepatic vein in LDLT with a left lobe graft, which makes anastomosis of the hepatic vein sterically easy for postoperative venous patency.

Automated segmentation of liver and hepatic vessels on portal venous phase computed tomography images using a deep learning algorithm.

BACKGROUND: CT-image segmentation for liver and hepatic vessels can facilitate liver surgical planning. However, time-consuming process and inter-observer variations of manual segmentation have limited wider application in clinical practice. PURPOSE: Our study aimed to propose an automated deep learning (DL) segmentation algorithm for liver and hepatic vessels on portal venous phase CT images. METHODS: This retrospective study was performed to develop a coarse-to-fine DL-based algorithm that was trained, validated, and tested using private 413, 52, and 50 portal venous phase CT images, respectively. Additionally, the performance of the DL algorithm was extensively evaluated and compared with manual segmentation using an independent clinical dataset of preoperative contrast-enhanced CT images from 44 patients with hepatic focal lesions. The accuracy of DL-based segmentation was quantitatively evaluated using the Dice Similarity Coefficient (DSC) and complementary metrics [Normalized Surface Dice (NSD) and Hausdorff distance_95 (HD95) for liver segmentation, Recall and Precision for hepatic vessel segmentation]. The processing time for DL and manual segmentation was also compared. RESULTS: Our DL algorithm achieved accurate liver segmentation with DSC of 0.98, NSD of 0.92, and HD95 of 1.52 mm. DL-segmentation of hepatic veins, portal veins, and inferior vena cava attained DSC of 0.86, 0.89, and 0.94, respectively. Compared with the manual approach, the DL algorithm significantly outperformed with better segmentation results for both liver and hepatic vessels, with higher accuracy of liver and hepatic vessel segmentation (all p < 0.001) in independent 44 clinical data. In addition, the DL method significantly reduced the manual processing time of clinical postprocessing (p < 0.001). CONCLUSIONS: The proposed DL algorithm potentially enabled accurate and rapid segmentation for liver and hepatic vessels using portal venous phase contrast CT images.

Intrahepatic and anterior course of the inferior vena cava: CT image and 3D reconstruction of a rare anatomical variation.

The widespread use of computed tomography (CT) for diagnosing and screening abdominal conditions often reveals rare, asymptomatic anomalies. There is a wide range of documented congenital variations in the anatomy of the inferior vena cava (IVC) and hepatic veins. In this report, we detail an exceptionally unusual variant of the IVC that follows a frontward and intraliver course, terminating at the anterior section of the right atrium. To gain a deeper insight into this anomaly, we employed 3D reconstruction techniques using the software Slicer and Blender.