Resection and reconstruction of the largest abdominal vein system (the inferior vena cava, hepatic, and portal vein): a narrative review.

Background and Objective: As tumors invade major abdominal veins, surgical procedures are transformed from simple and basic to complicated and challenging. In this narrative review, we focus on what is currently known and not known regarding the technical aspects of major abdominal venous resection and its reconstruction, patency, and oncologic benefit in a cross-cutting perspective. Methods: A systematic literature search was performed in PubMed and Semantic Scholar from inception up to October 18, 2023. We reviewed 106 papers by title, abstract, and full text regarding resection or reconstruction of the inferior vena cava, hepatic vein confluence, portal vein (PV), and middle hepatic vein (MHV) tributaries in living donor liver transplantation (LDLT) in a cross-cutting perspective. Key Content and Findings: The oncologic benefit of aggressive hepatic vein resection with suitable reconstruction against adenocarcinoma remains unclear, and further studies are required to clarify this point. A superior mesenteric/PV resection is now a universal, indispensable, and effective procedure for pancreatic ductal adenocarcinoma. Although many case series using tailor-made autologous venous grafts have been reported, not only size mismatch but also additional surgical incisions and a longer operation time remain obstacles for venous reconstruction. The use of autologous alternative tissue remains only an alternative procedure because the patency rate of customized tubular conduit type to interpose or replace the resected vein is not known. Unlike arterial replacement, venous replacement using synthetic vascular grafts is still rarely reported and there are several inherent limitations except for reconstruction of tributaries of MHV in LDLT. Conclusions: Various approaches to abdominal vein resection and replacement or reconstruction are technically feasible with satisfactory results. Synthetic vascular grafts may be appropriate but have a certain rate of complications.

The impact of the covalently closed circular DNA level on recurrence of hepatocellular carcinoma after initial hepatectomy: an analysis of patients with resolved hepatitis B virus infection.

BACKGROUND: We assessed whether or not covalently closed circular DNA (cccDNA) levels in the background liver influence the recurrence of hepatocellular carcinoma (HCC) in patients with resolved hepatitis B virus (HBV) infection. METHODS: Among 425 patients who underwent initial hepatectomy for HCC between 2010 and 2018, a retrospective review was performed in 44 with resolved HBV infection. The clinicopathologic characteristics were analyzed for correlation with tumor recurrence. The HBV cccDNA levels were tested via a droplet digital polymerase chain reaction assay. RESULTS: HBV cccDNA was detected in 27 of 44 patients (61%), and the median level was 1.0 copies/1000 ng (range, 0-931.3 copies/1000 ng). Anti-HBc ≥8.9 S/CO was associated with cccDNA detection (odds ratio, 11.08; 95% confidence interval [95% CI], 2.48-49.46; P = 0.002). Twenty-eight patients (64%) developed HCC recurrence after hepatectomy. The overall 3- and 5-year recurrence-free survival rates were 45.7% and 34.3%, respectively.19 HBV cccDNA levels was not significantly associated with HCC recurrence, while the presence of multiple tumors was an independent risk fact or (hazard ratio, 6.53; 95% CI, 2.48-17.19; P < 0.001. CONCLUSION: HBV cccDNA levels did not influence HCC recurrence after hepatectomy. Anti-HBc levels may be used as a surrogate marker for cccDNA.

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.

Repeat Hepatectomy After Major Hepatectomy for Colorectal Liver Metastases.

OBJECTIVE: This study assessed predictors of survival after repeat hepatectomy and the feasibility of a repeat hepatectomy after a major hepatectomy in the patients with colorectal liver metastases (CLM). BACKGROUND: More than half of all patients who receive a curative initial hepatectomy for CLM develop hepatic recurrence, and aggressive indications for a repeat hepatectomy can improve the outcome in selected patients. However, the feasibility of repeat hepatectomy after major hepatectomy remains uncertain, and optimal selection criteria for repeat hepatectomy have not yet been established. METHODS: Data were collected retrospectively on 296 CLM patients who underwent an initial curative hepatectomy between 2007 and 2017 at our institution. The postoperative outcomes of patients undergoing a repeat hepatectomy after major hepatectomy were assessed, and independent predictors of survival were investigated. RESULTS: After a median follow-up period of 32 months, 247 patients (83%) developed disease recurrence and 122 patients (49%) underwent repeat hepatectomy. The 5-year overall survival (OS) was significantly higher in patients who underwent a repeat hepatectomy than in those who did not receive repeat hepatectomy (51% vs. 19%, respectively; P < 0.001). In a multivariate analysis, an extrahepatic lesion at the time of the repeat hepatectomy (HR, 2.49; P = 0.001) and 5 or more liver tumors at the time of recurrence (HR, 1.88; P = 0.04) remained as independent factors negatively affecting OS after repeat hepatectomy. The type of operative procedure and the intraoperative and postoperative factors at the time of the initial hepatectomy did not have any significant influence on the OS after repeat hepatectomy. No significant difference in OS was found between patients who received repeat hepatectomy after major hepatectomy (n = 43) and those after non-major hepatectomy (n = 79). CONCLUSIONS: The operative procedure and the liver tumor status at the time of the initial hepatectomy have little impact on the indications for a repeat hepatectomy for recurrent CLM. Repeat hepatectomy is feasible even if major hepatectomy was initially performed.

Quantitative Assessment of the Accuracy of Real-Time Virtual Sonography for Liver Surgery.

Background. Real-time virtual sonography (RVS) is a navigation system for liver surgery. In this study, the degree of misalignment of intraoperative RVS images with computed tomographic (CT) images was measured. Methods. Between December 2014 and July 2015, intraoperative RVS was performed in a total of 33 patients undergoing liver surgery. Reconstructed CT images, rendered like intraoperative ultrasonographic (IOUS) images, were adjusted with the IOUS images and visualized side by side. The degree of misalignment between the reconstructed CT images and IOUS images was measured at anterior section, posterior section, and left liver in each patient. Furthermore, the time required for the adjustment was measured as the "adjustment time." Results. The degree of misalignment between the images could potentially be measured for a total of 96 points in the 33 patients. Of these, the actual measurement could not be conducted for 35 points due to poor visualization of the intrahepatic vasculature (n = 20) or to a large misalignment that hampered continuation of further adjustment (n = 15). The median degree of misalignment was 9.8 mm (range = 2.4-37.6 mm) in the right anterior section, 9.8 mm (range = 2.7-71.5 mm) in the right posterior section, and 9.5 mm (range = 0.9-37.6 mm) in the left liver. The median adjustment time was 105 seconds (range = 51-245 seconds). Conclusions. Although some misalignment occurred, it might be acceptable for selected situations. Further investigation is needed to reduce the frequency of adjustment failure.

Efficacy of Hyaluronic Acid/Carboxymethyl Cellulose-Based Bioresorbable Membranes in Reducing Perihepatic Adhesion Formation: A Prospective Cohort Study.

BACKGROUND: Perihepatic adhesions induced by hepatectomy make the subsequent repeat hepatectomy technically demanding. The aim of this study was to verify the effect of hyaluronic acid/carboxymethyl cellulose-based bioresorbable membrane (HA membrane) in preventing posthepatectomy adhesion formation by focusing on the ease of the adhesiolysis in subsequent hepatectomy for recurrent tumors. METHODS: A total of 201 patients who underwent hepatectomy using HA membrane were prospectively followed-up for 3 years. Thirty of the 201 patients underwent a repeat hepatectomy for recurrence. The operative data of 85 cases of repeat hepatectomy, the primary hepatectomy of which had been performed without the use of HA membrane, served as the historical control data. The primary endpoint was the time interval between the skin incision and the start of hepatic parenchymal transection (the preparation time) including adhesiolysis. Secondary endpoints were blood loss during the operation, incidence of postoperative complications, and the biochemical data. RESULTS: The median preparation time (183 vs. 228 min; p = 0.027) and total operation time (374 vs. 439 min; p = 0.041) were significantly shorter in the HA membrane group than in the control group. CONCLUSION: Use of HA membranes during hepatectomy enabled significant shortening of the adhesiolysis time during the sequential hepatectomy performed for recurrent tumors.

Aggressive Hemihepatectomy Combined with Resection and Reconstruction of Middle Hepatic Vein for Intrahepatic Cholangiocarcinoma.

BACKGROUND: Major hepatectomy for intrahepatic cholangiocarcinoma (ICC) sometimes involves resection of major hepatic veins, which might result in the future liver remnant (FLR) congestion. The necessity and efficacy of resection and reconstruction of the middle hepatic vein (MHV) during right or left hemihepatectomy for resection of ICC remains unclear. METHODS: Between 1995 and 2013, 68 patients underwent right (n = 24) or left hemihepatectomy (n = 44) for primary ICC, with (n = 27) or without (n = 41) resection of MHV. If the noncongested FLR volume was <40 % of the total liver volume, reconstruction of major hepatic veins was considered. RESULTS: No significant differences between the groups were observed for patients with or without resection of MHV in the pathologic findings, including negative surgical margins (81 vs. 85 %, P = 0.67) and overall survival (5-year survival rate: 18.3 vs. 33.4 %, P = 0.26). In five patients who underwent venous resection and reconstruction, the noncongested FLR increased from 37 to 74 % after reconstruction (P < 0.01); this noncongested FLR was almost similar to the patients without venous resection (72 %). Three patients undergoing venous resection without reconstruction developed postoperative hepatic failure (grade A in 2 and grade B in 1; International study group of liver surgery definition); however, there was no surgical mortality. CONCLUSIONS: Aggressive hemihepatectomy for ICC with venous resection in the FLR resulted in acceptable long-term outcome with no mortality when considering hepatic venous reconstruction based on our criterion.

Surgical Indications and Procedures for Resection of Hepatic Malignancies Confined to Segment VII.

OBJECTIVE: To establish a strategy for surgical resection of hepatic malignancies confined to segment VII. BACKGROUND: Various surgical procedures can be used to resect hepatic malignancies in segment VII, the deepest region of the liver, by open and/or laparoscopic approaches: nonanatomic wedge resection (WR), segmentectomy VII, right lateral sectionectomy (RLS), and right hepatectomy. METHODS: WR and segmentectomy VII were applied as first-line surgical procedures for colorectal liver metastasis (CRLM) and hepatocellular carcinoma (HCC), respectively. RLS and right hepatectomy were indicated only when tumor infiltration to the proximal Glissonian sheath was suspected. Operative outcomes were evaluated in 200 consecutive patients who underwent hepatic resection for HCC (n = 120) or CRLM (n = 80). RESULTS: WR, segmentectomy VII, RLS, and right hepatectomy were performed in 104 (52.0%), 57 (28.5%), 22 (11.0%), and 17 (8.5%) patients, respectively. Local hepatectomy (WR and segmentectomy VII) led to shorter operation times and lower blood loss volumes than did extensive hepatectomy (RLS and right hepatectomy). Thoracotomy was performed in half of the WR and two-thirds of the segmentectomy VII procedures. The availability of a laparoscopic approach was 40% (8 patients) after its application in October 2012. CONCLUSIONS: Even for hepatic malignancies located in segment VII, WR and segmentectomy should be prioritized over extensive hepatectomy to preserve the postoperative functional hepatic volume. Full mobilization of the right liver and a good surgical field provided by a large thoracoabdominal or abdominal incision or a laparoscopic approach are key factors for safe performance of deep hepatic transection.

Photoacoustic tomography of human hepatic malignancies using intraoperative indocyanine green fluorescence imaging.

Recently, fluorescence imaging following the preoperative intravenous injection of indocyanine green has been used in clinical settings to identify hepatic malignancies during surgery. The aim of this study was to evaluate the ability of photoacoustic tomography using indocyanine green as a contrast agent to produce representative fluorescence images of hepatic tumors by visualizing the spatial distribution of indocyanine green on ultrasonographic images. Indocyanine green (0.5 mg/kg, intravenous) was preoperatively administered to 9 patients undergoing hepatectomy. Intraoperatively, photoacoustic tomography was performed on the surface of the resected hepatic specimens (n = 10) under excitation with an 800 nm pulse laser. In 4 hepatocellular carcinoma nodules, photoacoustic imaging identified indocyanine green accumulation in the cancerous tissue. In contrast, in one hepatocellular carcinoma nodule and five adenocarcinoma foci (one intrahepatic cholangiocarcinoma and 4 colorectal liver metastases), photoacoustic imaging delineated indocyanine green accumulation not in the cancerous tissue but rather in the peri-cancerous hepatic parenchyma. Although photoacoustic tomography enabled to visualize spatial distribution of ICG on ultrasonographic images, which was consistent with fluorescence images on cut surfaces of the resected specimens, photoacoustic signals of ICG-containing tissues decreased approximately by 40% even at 4 mm depth from liver surfaces. Photoacoustic tomography using indocyanine green also failed to identify any hepatocellular carcinoma nodules from the body surface of model mice with non-alcoholic steatohepatitis. In conclusion, photoacoustic tomography has a potential to enhance cancer detectability and differential diagnosis by ultrasonographic examinations and intraoperative fluorescence imaging through visualization of stasis of bile-excreting imaging agents in and/or around hepatic tumors. However, further technical advances are needed to improve the visibility of photoacoustic signals emitted from deeply-located lesions.