Standardized measurement of the future liver remnant prior to extended liver resection: methodology and clinical associations

Simple diameter measurement as predictor of liver volume and liver parenchymal disease

To investigate the accuracy of liver diameters for estimation of liver size and to evaluate their application as tool for assessment of parenchymal liver disease. In the course of a population-based study, (SHIP) one thousand nine hundred thirty-nine volunteers underwent magnetic resonance imaging (MRI) of the liver including 3D gradient echo MRI sequences. Maximum liver diameters were measured in cranio-caudal (CC), anterior–posterior (AP), medial–lateral (ML) orientation. Diameters were compared with true liver volume assessed by liver segmentation. Additionally, age-dependent reference values for diameters were defined. Finally, accuracy of liver diameters was assessed to discriminate volunteers with healthy livers and participants with parenchymal changes, measured by MRI and laboratory. Reference values of liver diameters within the healthy population (n = 886) were defined as follows (mean ± standard deviation, confidence interval CI in cm): CC 17.2 ± 2, CI 13.6/21.2; AP 15.8 ± 1.9, CI 12.6/19.8; ML 19.7 ± 2.3, CI 15.8/24.6. There was a poor correlation using linear regression between liver diameter and true liver volume; CC 0.393, AP 0.359; ML 0.137. The AP direction shows the best correlation to discriminate between healthy and pathologic liver changes; AUC 0.78; p < 0.001, CC AUC 0.53; p < 0.001 and ML AUC 0.52; p = 0.008. Measurement of liver diameter, especially in the anterior–posterior direction is a simple option to detect chronic liver disease but less suitable for prediction of liver volume.

Locally advanced gallbladder cancer treated with effective chemotherapy and subsequent curative resection: a case report

Background

Surgical resection of gallbladder cancer with negative margins is the only potentially curative therapy. Most patients with gallbladder cancer are diagnosed in an advanced stage and, despite the availability of several chemotherapies, the prognosis remains dismal. We report a case of locally advanced gallbladder cancer that was successfully treated with effective cisplatin plus gemcitabine, followed by curative resection.

Case presentation

A 55-year-old Japanese female was hospitalized with right hypochondrial pain. Enhanced computed tomography revealed a 49 × 47 mm mass at the neck of the gallbladder, with suspected invasion of the liver and right hepatic artery. Endoscopic retrograde cholangiopancreatography demonstrated displacement of the upper bile duct. Intraductal ultrasonography showed irregular wall thickening and disappearance of the wall structure in bile ducts from the B4 branch to distal B2 and B3. Percutaneous transhepatic biliary biopsy revealed a poorly differentiated carcinoma. The patient was diagnosed with unresectable gallbladder cancer (T4N0M0 stage IVA). Cisplatin plus gemcitabine chemotherapy was initiated. After six courses of chemotherapy, enhanced computed tomography showed that the mass in the neck of the gallbladder had shrunk to 30 mm, Endoscopic retrograde cholangiopancreatography showed improvement of the hilar duct stenosis. A biopsy of the bile duct mucosa showed no malignant cells in the branch of the left and right hepatic ducts, the left hepatic duct, or the intrapancreatic ducts. The patient underwent conversion surgery with right and segment 4a liver resection, extrahepatic duct resection, and cholangiojejunostomy. The histopathologic diagnosis showed that the tumor cells had shrunk to 2 × 1 mm, and that R0 resection of the T2aN0M0 stage IIA tumor was successful.

Conclusion

Although conversion surgery for gallbladder cancer is rarely possible, curative resection may offer a better prognosis, and it is important to regularly pursue possibilities for surgical resection even during chemotherapy.

Repeatability and reproducibility of deep-learning-based liver volume and Couinaud segment volume measurement tool

Purpose

Volumetric and health assessment of the liver is crucial to avoid poor post-operative outcomes following liver resection surgery. No current methods allow for concurrent and accurate measurement of both Couinaud segmental volumes for future liver remnant estimation and liver health using non-invasive imaging. In this study, we demonstrate the accuracy and precision of segmental volume measurements using new medical software, Hepatica™.

Methods

MRI scans from 48 volunteers from three previous studies were used in this analysis. Measurements obtained from Hepatica™ were compared with OsiriX. Time required per case with each software was also compared. The performance of technicians and experienced radiologists as well as the repeatability and reproducibility were compared using Bland–Altman plots and limits of agreement.

Results

High levels of agreement and lower inter-operator variability for liver volume measurements were shown between Hepatica™ and existing methods for liver volumetry (mean Dice score 0.947 ± 0.010). A high consistency between technicians and experienced radiologists using the device for volumetry was shown (± 3.5% of total liver volume) as well as low inter-observer and intra-observer variability. Tight limits of agreement were shown between repeated Couinaud segment volume (+ 3.4% of whole liver), segmental liver fibroinflammation and segmental liver fat measurements in the same participant on the same scanner and between different scanners. An underestimation of whole-liver volume was observed between three non-reference scanners.

Conclusion

Hepatica™ produces accurate and precise whole-liver and Couinaud segment volume and liver tissue characteristic measurements. Measurements are consistent between trained technicians and experienced radiologists.

Graphic abstract

Supplementary Information

The online version contains supplementary material available at 10.1007/s00261-021-03262-x.

99mTc-GSA scintigraphy for assessing the functional volume ratio of the future liver remnant in the routine practice of liver resection

Background

The significance of incorporating regional functional heterogeneity assessment by liver scintigraphy into the calculation of the future liver remnant has been reported. However, liver scintigraphy entails additional costs and radiation exposure. Nevertheless, studies describing when liver scintigraphy demonstrates an actual benefit over computed tomography liver volumetry are lacking. Thus, we evaluated the degree of agreement between future liver remnant % values calculated by technetium ^99mTc diethylenetriaminepentaacetic acid-galactosyl human serum albumin scintigraphy (galactosyl human serum albumin–based future liver remnant %) and those by computed tomography volumetry and investigated the practical impact of performing regional functional heterogeneity assessment.

Methods

The Bland–Altman method was used to retrospectively analyze the agreement between computed tomography– and galactosyl human serum albumin–based future liver remnant % measurements in 84 patients.

Results

In ordinary patients with a computed tomography–based future liver remnant % greater than 50%, there was a good agreement between both measurements. However, in cases with a computed tomography–based future liver remnant % less than 40%, galactosyl human serum albumin–based measurements were significantly smaller than computed tomography–based values, with 88% of these patients exhibiting a galactosyl human serum albumin–based future liver remnant % less than 30%. After portal vein embolization, galactosyl human serum albumin–based measurements were primarily greater than or in agreement with computed tomography–based values, even in cases with a computed tomography–based future liver remnant % less than 40%.

Conclusion

Adding ^99mTc diethylenetriaminepentaacetic acid-galactosyl human serum albumin scintigraphy to computed tomography liver volumetry is advised when deciding on hepatectomy in patients with a computed tomography–based future liver remnant % less than 50%. If the computed tomography–based future liver remnant % is smaller than 40%, it is strongly recommended to check future liver remnant % by ^99mTc diethylenetriaminepentaacetic acid-galactosyl human serum albumin scintigraphy. In other cases, computed tomography–based future liver remnant % calculation alone can be regarded as the gold standard of safe hepatectomy.

Role of CT in Two-Stage Liver Surgery

Complete resection is the only potentially curative treatment for primary or metastatic liver tumors. Improvements in surgical techniques such as conventional two-stage hepatectomy (TSH) with portal vein embolization and ALPPS (associating liver partition and portal vein ligation for staged hepatectomy) promote hypertrophy of the future liver remnant (FLR), expanding resection criteria to include patients with widespread hepatic disease who were formerly not considered candidates for resection. Radiologists are essential in the multidisciplinary approach required for TSH. In particular, multidetector CT has a critical role throughout the various stages of this surgical process. The aims of CT before the first stage of TSH are to define the feasibility of surgery, assess the number and location of liver tumors in relation to relevant anatomy, and provide a detailed anatomic evaluation, including vascular and biliary variants. Volume calculation with CT is also essential to determine if the FLR is sufficient to avoid posthepatectomy liver failure. The objectives of CT between the first and second stages of TSH are to recalculate liver volumes (ie, assess FLR hypertrophy) and depict expected liver changes and complications that could modify the surgical plan or preclude the second stage of definitive resection. In this review, the importance of CT throughout different stages of TSH is discussed and key observations that contribute to surgical planning are highlighted. In addition, the advantages and limitations of MRI for detection of liver metastases and assessment of complications are briefly described. ^©RSNA, 2022.

Liver regeneration biology: Implications for liver tumour therapies

The liver has remarkable regenerative potential, with the capacity to regenerate after 75% hepatectomy in humans and up to 90% hepatectomy in some rodent models, enabling it to meet the challenge of diverse injury types, including physical trauma, infection, inflammatory processes, direct toxicity, and immunological insults. Current understanding of liver regeneration is based largely on animal research, historically in large animals, and more recently in rodents and zebrafish, which provide powerful genetic manipulation experimental tools. Whilst immensely valuable, these models have limitations in extrapolation to the human situation. In vitro models have evolved from 2-dimensional culture to complex 3 dimensional organoids, but also have shortcomings in replicating the complex hepatic micro-anatomical and physiological milieu. The process of liver regeneration is only partially understood and characterized by layers of complexity. Liver regeneration is triggered and controlled by a multitude of mitogens acting in autocrine, paracrine, and endocrine ways, with much redundancy and cross-talk between biochemical pathways. The regenerative response is variable, involving both hypertrophy and true proliferative hyperplasia, which is itself variable, including both cellular phenotypic fidelity and cellular trans-differentiation, according to the type of injury. Complex interactions occur between parenchymal and non-parenchymal cells, and regeneration is affected by the status of the liver parenchyma, with differences between healthy and diseased liver. Finally, the process of termination of liver regeneration is even less well understood than its triggers. The complexity of liver regeneration biology combined with limited understanding has restricted specific clinical interventions to enhance liver regeneration. Moreover, manipulating the fundamental biochemical pathways involved would require cautious assessment, for fear of unintended consequences. Nevertheless, current knowledge provides guiding principles for strategies to optimise liver regeneration potential.

Complete Pathological Response to Neoadjuvant Chemoimmunotherapy in a Patient With Metastatic Intrahepatic Cholangiocarcinoma With High Tumor Mutational Burden

Intrahepatic cholangiocarcinoma (ICC) is an aggressive biliary tract cancer (BTC) with distinct anatomic, molecular, and clinical characteristics. Over the last 10-20 years, ICC has become the focus of increasing concern largely due to its rising incidence and high mortality rates in various parts of the world, including the United States.

Surgery is the only potentially curative treatment option for ICC; however, recurrence rate is high, and prognosis is poor in patients with recurrent disease. The chemotherapy regimen of gemcitabine-cisplatin (GemCis) is still the standard of care for patients with unresectable metastatic ICC. There is limited data regarding pathologic ICC response to palliatively intentioned systemic treatment.

Here, we report a case of a 47-year-old Caucasian male with metastatic ICC microsatellite stable (MSS) and TMB 49 mutation per megabase who achieved complete pathological response with sequential GemCis/nab-paclitaxel and pembrolizumab. This case highlights the effect of sequential neoadjuvant chemoimmunotherapy in a patient with high tumor mutational burden (TMB-H) ICC, emphasizing the importance of molecular testing, which provides valuable information that can be used in clinical practice to better select targeted chemotherapy regimens.

Short-term efficacy of precise hepatectomy and traditional hepatectomy for primary liver cancer: a systematic review and meta-analysis

BACKGROUND

As the base of hepatitis B patients has been increasing annually, it has developed into a high incidence source of primary liver cancer worldwide. The fatality rate of liver cancer is still relatively high. Among the many treatment methods, liver resection is the first-line treatment of primary liver cancer. Although precision hepatectomy has achieved rapid development in recent years, the understanding of its efficacy is still not completely clear. This study aimed to analyze and compare the safety and effectiveness of precision hepatectomy and traditional hepatectomy in the treatment of primary liver cancer.

METHODS

We performed a literature search of the CNKI, Wanfang, Weipu.com, PubMed, Cochrane Library, Web of Science databases for studies on precision liver resection (precision group) and traditional liver resection (traditional group) for the treatment of primary liver cancer. Data including the operation time, intraoperative blood loss, hospital stay, postoperative complications, liver function, and survival rate were analyzed using RevMan 5.3 software to compare the differences in the effects of the two surgical procedures.

RESULTS

Ten articles were included in the study, involving a total of 1,969 patients, including 1,045 cases in the precision group and 924 cases in the traditional group. Meta-analysis results showed that compared with the traditional group, the precision group had a longer operation time [mean difference (MD) =8.01, P=0.004], and total bilirubin (TBiL; MD =-2.78, P=0.055) was similar. Meanwhile, the precision group exhibited advantages in terms of intraoperative blood loss (MD =-149.37, P=0.000), hospital stay (MD =-5.59, P=0.000), postoperative liver function indexes [aspartate aminotransferase (AST; MD =-11.61, P=0.000) and alanine aminotransferase (ALT; MD =-18.53, P=0.000)], postoperative complication rate [relative risk (RR) =0.51, P=0.000], and 1-year survival rate (RR =1.11, P=0.000).

DISCUSSION

The application of precision surgery in the treatment of primary liver cancer can be a safe and effective method. It can minimize intraoperative blood loss, mitigate surgical risk, reduce postoperative complications, improve patient prognosis and quality of life, and provide better short-term curative effect and patient benefits.

Technique of vessel-skeletonized parenchyma-sparing hepatectomy for the oncological treatment of bilobar colorectal liver metastases

BACKGROUND

To aid in the oncological management of multiple bilobar colorectal liver metastases (CRLMs), we describe a new surgical procedure, VEssel-Skeletonized PArenchyma-sparing Hepatectomy (VESPAH).

STUDY DESIGN

Of 152 patients with CRLMs treated with hepatectomy, 33 patients had multiple bilobar liver metastases (≥8 liver metastases); their surgical procedures and clinical outcomes were retrospectively summarized and compared between those who underwent VESPAH and those who underwent major hepatectomy (Major Hx).

RESULTS

Of the 33 patients, 20 patients were resected by VESPAH (the VESPAH group) and 13 patients by major hepatectomy (Major Hx group). The median number of CRLMs was 13 (range, 8-53) in the VESPAH group and 10 (range, 8-41) in the Major Hx group (P=0.511). No operative mortality nor severe morbidity was observed in either group. The VESPAH group showed earlier recovery of remnant liver function after surgery than the Major Hx group; the incidence of grade B/C post hepatectomy liver failure was 5% in the VESPAH group and 38% in the Major Hx group, P=0.048). Intrahepatic tumor recurrence was confirmed in 14 (70%) and 7 (54%) patients in the VESPAH and Major Hx groups, respectively (P=0.416). There was no significant difference in median overall survival (OS) after hepatectomy between the two groups; the median OS was 47 months in the VESPAH group and 33 months in the Major Hx group (P=0.481). The VESPAH group showed the higher induction rate of adjuvant chemotherapy within 2 months after surgery (P=0.002) and total number of repeat hepatectomy for intrahepatic recurrence (P=0.060) than the Major Hx group.

CONCLUSIONS

VESPAH enables us to clear surgical navigation by hepatic vessel skeletonization and may enhance patient tolerability of not only adjuvant chemotherapy but also repeat hepatectomies during the patients' lifetimes.

Surgical management of intrahepatic cholangiocarcinoma

INTRODUCTION

Intrahepatic cholangiocarcinoma (ICC) incidence continues to rise worldwide, and overall survival remains poor. Complete surgical resection remains the only opportunity for cure in patients with ICC yet only one-third of patients present with resectable disease.

AREAS COVERED

While the low incidence rate of ICC hinders accrual of patients to large, randomized control trials, larger database and long-term institutional studies provide evidence to guide surgical management of ICC. These studies demonstrate feasibility, safety, and efficacy of aggressive surgical management in appropriately selected patients with ICC. Recent advances in the management of ICC, with a focus on surgical considerations, are reviewed.

EXPERT OPINION

Historically, little progress has been made in the management of ICC with stagnant mortality rates and poor long-term outcomes. However, regionalization of care to centers with experienced multidisciplinary teams, advances in minimally invasive surgical techniques, discovery and development of targeted and immunotherapy agents, and combination locoregional and systemic therapies offer signs of progress in the management of ICC.

Challenges and Opportunities for Treating Intrahepatic Cholangiocarcinoma

Intrahepatic cholangiocarcinoma (ICC) is one of the rarest and most aggressive types of cancer. The symptoms of ICC patients can be vague, leading to late diagnosis and dismal prognosis. In this review, we investigated the treatment options for ICC, as well as ways to overcome challenges in identifying and treating this disease. Imaging remains the gold standard to diagnose ICC. Patients are staged based on the tumor, nodes and metastases (TNM) staging system. Patients eligible for surgical resection should undergo surgery with curative intent with the goal of microscopically disease-free margins (R0 resection) along with lymphadenectomy. Minimal invasive surgery (MIS) and liver transplantation have recently been offered as possible ways to improve disease outcomes. ICC recurrence is relatively common and, thus, most patients will need to be treated with systemic therapy. Several clinical trials have recently investigated the use of neoadjuvant (NT) and adjuvant therapies for ICC. NT may offer an opportunity to downsize larger tumors and provide patients, initially ineligible for surgery, with an opportunity for resection. NT may also treat occult micro-metastatic disease, as well as define tumor biology prior to surgical resection, thereby decreasing the risk for early postoperative recurrence. Adjuvant systemic therapy may improve outcomes of patients with ICC following surgery. Ongoing clinical trials are investigating new targeted therapies that hold the hope of improving long-term outcomes of patients with ICC.

Mesohepatectomía, una alternativa para el manejo del hepatocarcinoma en paciente no cirrótico: serie de casos

Introducción. La resección quirúrgica es el tratamiento de elección de las neoplasias primarias y secundarias del hígado. Los pacientes con hepatocarcinoma de los segmentos centrales representan un reto, siendo la hepatectomía extendida la técnica más usada, sin embargo, el riesgo postquirúrgico de falla hepática es alto, dado que la resección puede comprometer entre el 65 % y el 80 % del volumen hepático. La mesohepatectomía es una alternativa que permite dejar un volumen hepático residual suficiente. El objetivo de este trabajo es presentar nuestra experiencia en el tratamiento de pacientes con hepatocarcinomas en segmentos centrales a quienes se les realizó mesohepatectomía. Serie de casos. Se presentan tres pacientes no cirróticos, con hepatocarcinoma en los segmentos 4, 5 y 8, que fueron atendidos en el Hospital San Vicente Fundación, en las sedes de Medellín y de Rionegro, entre 2018 y 2020. Resultados. La mesohepatectomía se realizó mediante ligadura selectiva de los pedículos del segmento 4 y del sector anterior derecho. Se utilizó aspirador ultrasónico y endograpadora para la transección hepática. La duración de la maniobra de Pringle varió entre 16 y 43 minutos. El sangrado promedio fue de 1000 ml. Solo un paciente presentó fuga biliar tipo B. No hubo mortalidad a 30 días. Conclusiones. La mesohepatectomía es una alternativa segura para pacientes con tumores en los segmentos centrales, que permite disminuir el riesgo de falla hepática luego de la resección.

Systematic Reviews and Meta-Analyses of Portal Vein Embolization, Associated Liver Partition and Portal Vein Ligation, and Radiation Lobectomy Outcomes in Hepatocellular Carcinoma Patients

PURPOSE OF REVIEW

To understand portal vein embolization (PVE), associated liver partition and portal vein ligation (ALPPS) and radiation lobectomy (RL) outcomes in hepatocellular carcinoma (HCC) patients. Systematic reviews of future liver remnant (FLR) percent hypertrophy, proportion undergoing hepatectomy and proportion with major complications following PVE, ALPPS, and RL were performed by searching Ovid MEDLINE, Ovid EMBASE, The Cochrane Library, and Web of Science. Separate meta-analyses using random-effects models with assessment of study heterogeneity and publication bias were performed whenever allowable by available data.

RECENT FINDINGS

Of the 10,616 articles screened, 21 articles with 636 subjects, 4 articles with 65 subjects, and 4 articles with 195 subjects met the inclusion criteria for systematic reviews and meta-analyses for PVE, ALPPS, and RL, respectively. The pooled estimate of mean percent FLR hypertrophy was 30.9% (95%CI: 22-39%, Q = 4034.8, p < 0.0001) over 40.3 +/- 26.3 days for PVE, 54.9% (95%CI: 36-74%, Q = 73.8, p < 0.0001) over 11.1 +/- 3.1 days for ALPPS, and 29.0% (95%CI: 23-35%, Q = 56.2, p < 0.0001) over 138.5 +/- 56.5 days for RL. The pooled proportion undergoing hepatectomy was 91% (95%CI: 83-95%, Q = 43.9, p = 0.002) following PVE and 98% (95%CI: 50-100%, Q = 0.0, p = 1.0) following ALPPS. The pooled proportion with major complications was 5% (95%CI: 2-10%, Q = 7.3, p = 0.887) following PVE and 38% (95%CI: 18-63%, Q = 10.0, p = 0.019) following ALPPS. Though liver hypertrophy occurs following all three treatments in HCC patients, PVE balances effective hypertrophy with a short time frame and low major complication rate.

Development of Models to Predict Postoperative Complications for Hepatitis B Virus-Related Hepatocellular Carcinoma

Background

Surgical treatment remains the best option for patients with hepatocellular carcinoma (HCC) caused by chronic hepatitis B virus (HBV) infection. However, there is no optimal tool based on readily accessible clinical parameters to predict postoperative complications. Herein, our study aimed to develop models that permitted risk of severe complications to be assessed before and after liver resection based on conventional variables.

Methods

A total of 1,047 patients treated by hepatectomy for HCC with HBV infection at three different centers were recruited retrospectively between July 1, 2014, and July 1, 2018. All surgical complications were recorded and scored by the Comprehensive Complication Index (CCI). A CCI ≥26.2 was used as a threshold to define patients with severe complications. We built two models for the CCI, one using preoperative and one using preoperative and postoperative data. Besides, CCI and other potentially relevant factors were evaluated for their ability to predict early recurrence and metastasis. All the findings were internally validated in the Hangzhou cohort and then externally validated in the Lanzhou and Urumqi cohorts.

Results

Multivariable analysis identified National Nosocomial Infections Surveillance (NNIS) index, tumor number, gamma-glutamyltransferase (GGT), total cholesterol (TC), potassium, and thrombin time as the key preoperative parameters related to perioperative complications. The nomogram based on the preoperative model [preoperative CCI After Surgery for Liver tumor (CCIASL-pre)] showed good discriminatory performance internally and externally. A more accurate model [postoperative CCI After Surgery for Liver tumor (CCIASL-post)] was established, combined with the other four postoperative predictors including leukocyte count, basophil count, erythrocyte count, and total bilirubin level. No significant association was observed between CCI and long-term complications.

Conclusion

Based on the widely available clinical data, statistical models were established to predict the complications after hepatectomy in patients with HBV infection. All the findings were extensively validated and shown to be applicable nationwide. Such models could be used as guidelines for surveillance follow-up and the design of post-resection adjuvant therapy.

Determination of the segmental hepatic clearance rate of 99mTc-mebrofenin and its application in the functional assessment of future liver remnant after liver resection

^99mTc-mebrofenin hepatobiliary scintigraphy with SPECT/CT (HBS-M) has become an important quantitative method to evaluate global liver function and future liver remnant (FLR) function in patients who are candidates for resective liver surgery. The purpose of this work was to describe the method in the prediction of post-surgical liver failure. The overall liver function and that of the FLR are obtained by analysis of the initial dynamic phase of the scan. Liver volume to be preserved is expressed as a percentage of the total liver volume measured in both CT sections. HBS-M is able to accurately gauge regional liver function abnormalities that could be represented as normal liver tissue parenchyma in the CT study. This technique can provide very valuable prognostic information for the estimation of the postoperative risk of liver failure in all patients who are candidates for resective liver surgery.

Predictors of residual hepatic reserve and hepatic decompensation in cirrhotic patients after ablated hepatocellular carcinoma treated by DDAs or systemic therapy

Background

Therapeutic interventions for hepatocellular carcinoma (HCC) particularly in patients with advanced liver disease may lead to more aggravation of clinical and biochemical parameters of liver functions. We aimed to assess the utilization of easily applied variables which evaluate residual hepatic reserve to predict liability for complications and hepatic decompensation in cirrhotic patients with ablated HCC particularly when these patients were exposed to specific medical treatment such as DAAs and systemic therapy for HCC such as sorafenib.

This study included 3 groups with HCC. Group 1: patients with ablated HCC and Child-Turcotte-Pugh (CTP) class A, who received Sofosbuvir (SOF)-based treatment (n = 250), group 2: HCC patients CTP (A), managed with sorafenib after transarterial chemoembolization (TACE) (n = 250) and group 3 as a control group of non-cirrhotic patients (n = 176). Evaluation for all patients was done by routine laboratory investigations including liver and kidney functions, complete blood count, platelet indices and plasma ammonia, upper gastrointestinal (GI) endoscopy and estimation of liver volume by ultrasound and liver stiffness (LS) by Fibroscan.

Results

Unfavorable outcome and increased incidence of complications during DAAs were independently associated with severity of thrombocytopenia (p = 0.001) at a cut-off 78,000/μl, LS > 20 kPa (p = 0.001), liver volume < 500 ml (p = 0.002), and gamma globulin levels > 4 gm/dl (p = 0.004).

In the sorafenib group, unfavorable outcome and complications were independently associated with PDW/MPV ratio > 2.74 (p = 0.001), level of ammonia > 87 μg/dl (p = 0.001), LS > 25 kPa (p = 0.001), and liver volume < 490 ml (p = 0.001).

Conclusion

Non-invasive parameters of residual hepatic reserve are promising tools to guide therapy and avoid further complications in patients with liver cirrhosis and ablated HCC.

Imaging Evaluation of Living Liver Donor Candidates: Techniques, Protocols, and Anatomy

The need for liver transplants is increasing because the prevalence of liver diseases and the indications for transplants are growing. In response to the shortage of grafts from deceased donors, more transplants are being performed worldwide with grafts from living donors. Radiologic evaluation is an integral component in the assessment of donor candidates to ensure their eligibility and to choose the most appropriate surgical approach. MRI is the preferred modality for evaluation of the liver parenchyma and biliary tree. In most centers, a combination of MRI and CT is used to take advantage of the higher spatial resolution of CT for evaluation of arteries. However, MRI-only assessment is feasible. In addition to assessment of the liver parenchyma for abnormalities such as steatosis, a detailed evaluation of the hepatic vascular and biliary system for pertinent anatomic variants is crucial, because these variants can affect surgical techniques and outcomes in both recipients and donors. In this pictorial article, after a brief review of the most common surgical techniques and postsurgical liver anatomy, the biliary and vascular anatomy are discussed, with specific attention paid to the variants that are pertinent to this surgical procedure. The roles of liver segmentation and volumetric assessment and current imaging techniques and protocols are also discussed. Online supplemental material is available for this article. ©RSNA, 2021.

Clinical application of a three-dimensional reconstruction technique for complex liver cancer resection

OBJECTIVE

To explore the utility of three-dimensional (3D) visualization technology in liver resection for patients with complex liver cancer.

METHODS

In this retrospective cohort study, we collected and analyzed clinic pathological data from 105 patients who underwent complicated liver cancer resection at the authors' unit between January 2014 and June 2019. Observation indicators included general demographic information, operative time, intraoperative blood loss, blood transfusion volume, postoperative liver function, complication rate, hospital stay, and in-hospital mortality.

RESULTS

Compared with the complex liver cancer control group, operative time (257.1  ±  63.4 min versus [vs] 326.6  ±  78.3 min; P < 0.001), intraoperative blood loss (256.4  ±  159.1 mL vs 436.1  ±  177.3 mL; P < 0.001), blood transfusion volume (213.3  ±  185.2 mL vs 401.6  ±  211.2 mL; P < 0.001), and length of hospital stay (9.7  ±  3.1 days vs 11.9  ±  3.3 days; P = 0.001) were significantly reduced in the complex liver cancer reconstruction group. Although there was no statistical difference in total postoperative complication rate between the two groups, the incidence of serious postoperative complications in the reconstruction group was significantly lower than that in the control group (3/54 [5.6%] vs 10/51 [19.6%], respectively; P = 0.038). Regarding laboratory investigations, the time to recovery of liver function in the complex liver cancer reconstruction group was shorter than that in the complex liver cancer control group.

CONCLUSION

The use of 3D visualization technology was highly influential in formulating meticulous, individualized surgical strategies for complex liver cancer liver resection with safety and reduced perioperative risk.

Lower Ratio of Liver Volume and Body Weight Is a Negative Predictor of Survival after Transjugular Intrahepatic Portosystemic Shunt

Transjugular intrahepatic portosystemic shunt (TIPS) is the most effective measure to treat complications of portal hypertension. However, liver function may deteriorate after TIPS. Predictors of liver function and outcome after TIPS are therefore important for management of TIPS patients. The study aimed to evaluate the impact of liver volume on transplant-free survival (TFS) after TIPS, as well as the evolution of liver volume and its relationship with liver function after TIPS. A retrospective analysis of all consecutive patients who underwent TIPS in a tertiary care university liver center between 2012 and 2017 (n = 216) was performed; n = 72 patients with complete prior and follow-up (FU) computed tomography (CT) imaging studies were included in the study. Volumetry of the liver was performed by a semi-automatic 9-lobe image segmentation algorithm at baseline and FU (FU 1: 90–180 d; FU 2: 180–365 d; FU 3: 365–545 d; FU 4: 545–730 d; FU 5: >730 d). Output variables were total liver volume (TLV, cm³), left liver volume (LLV, cm³), right liver volume (RLV, cm³) and TLV/body weight ratio. CT derived liver volumes were correlated with liver function tests, portosystemic pressure gradient (PPG) measurements and survival. To assess predictors of liver volume change over time we fitted linear mixed models. Kaplan–Meier analysis was performed and validated by matched pair analysis followed by Cox regression to determine independent prognostic factors for survival. The median TLV at baseline was 1507.5 cm³ (773.7–3686.0 cm³). Livers with higher baseline liver volumes and larger TLV/weight ratios retained their volume after an initial loss while smaller livers continuously lost volume after TIPS. At the first follow-up period (90–180 d post-TIPS) lower liver volumes and TLV/weight ratios were associated with higher bilirubin levels. Within the final multivariable model containing time (days since TIPS), baseline INR and baseline TLV, the average loss of liver volume was 0.74 mL per day after TIPS. Twelve-month overall transplant-free survival was 89% and median overall TFS was 33 months. The median TFS for a baseline TLV/body weight ratio > 20 was significantly higher compared with ≤20 (40.0 vs. 27.0 months, p = 0.010) while there were no differences regarding the indication for TIPS or etiology of liver disease in the matched pair analysis. Lower TLV/weight ratios before TIPS were associated with shorter TFS and should therefore be critically considered when selecting patients for TIPS. In addition, this study provides first evidence of an effect of TIPS on subsequent liver volume change and associated liver function.

Population-based and Personalized Reference Intervals for Liver and Spleen Volumes in Healthy Individuals and Those with Viral Hepatitis

Background Reference intervals guiding volumetric assessment of the liver and spleen have yet to be established. Purpose To establish population-based and personalized reference intervals for liver volume, spleen volume, and liver-to-spleen volume ratio (LSVR). Materials and Methods This retrospective study consecutively included healthy adult liver donors from 2001 to 2013 (reference group) and from 2014 to 2016 (healthy validation group) and patients with viral hepatitis from 2007 to 2017. Liver volume, spleen volume, and LSVR were measured with CT by using a deep learning algorithm. In the reference group, the reference intervals for the volume indexes were determined by using the population-based (ranges encompassing the central 95% of donors) and personalized (quantile regression modeling of the 2.5th and 97.5th percentiles as a function of age, sex, height, and weight) approaches. The validity of the reference intervals was evaluated in the healthy validation group and the viral hepatitis group. Results The reference and healthy validation groups had 2989 donors (mean age ± standard deviation, 30 years ± 9; 1828 men) and 472 donors (mean age, 30 years ± 9; 334 men), respectively. The viral hepatitis group had 158 patients (mean age, 48 years ± 12; 95 men). The population-based reference intervals were 824.5-1700.0 cm³ for liver volume, 81.1-322.0 cm³ for spleen volume, and 3.96-13.78 for LSVR. Formulae and a web calculator (https://i-pacs.com/calculators) were presented to calculate the personalized reference intervals. In the healthy validation group, both the population-based and personalized reference intervals were used to classify the volume indexes of 94%-96% of the donors as falling within the reference interval. In the viral hepatitis group, when compared with the population-based reference intervals, the personalized reference intervals helped identify more patients with volume indexes outside the reference interval (liver volume, 21.5% [34 of 158] vs 13.3% [21 of 158], P = .01; spleen volume, 29.1% [46 of 158] vs 22.2% [35 of 158], P = .01; LSVR, 35.4% [56 of 158] vs 26.6% [42 of 158], P < .001). Conclusion Reference intervals derived from a deep learning approach in healthy adults may enable evidence-based assessments of liver and spleen volume in clinical practice. © RSNA, 2021 Online supplemental material is available for this article. See also the editorial by Ringl in this issue.

Fast-track two-stage hepatectomy by concurrent portal vein embolization at first-stage hepatectomy in hybrid interventional radiology / operating suite

OBJECTIVES

In two-stage hepatectomy for bilateral liver metastases, patient dropout between stages is a major issue. We recently proposed a novel approach of fast-track two-staged hepatectomy (FT-TSH), in which patients undergo concurrent first-stage hepatectomy (FSH) with portal vein embolization (PVE) in a hybrid interventional radiology surgical suite. However, its efficacy remains unclear.

METHODS

Patients with bilateral liver metastases scheduled for FT-TSH at MD Anderson Cancer Center between October 2017 and December 2020 were included on a prospective registry. The effectiveness and feasibility were evaluated.

RESULTS

Nineteen patients were scheduled for FT-TSH. Primary site of tumor was colon/rectum in 18 patients and ovary in one patient. Median number of tumors was 10 and median size of largest tumor before surgery was 2.4 cm. Two (11%) patients did not undergo PVE and seventeen patients (89%) completed FSH + PVE. None of the patients had a major complication (Clavien-Dindo grade ≥ III) after FSH + PVE. Median kinetic growth rate after FSH + PVE was 2.9%/week (range 0.8-5.6). Twelve patients (71%) among the seventeen who underwent FSH + PVE proceeded to second-stage hepatectomy, and ten patients (59%) finally completed second-stage hepatectomy. Median interval between stages was 5.6 weeks (4.0-20.1). One patient (10%) had a major morbidity after SSH, and there was no 90-day mortality.

CONCLUSIONS

FT-TSH is safe and allows for short intervals between hepatectomy stages while achieving favorable liver hypertrophy. Further investigation is needed to evaluate the true efficacy of FT-TSH.

An observational study to determine volume changes in the functional liver remnant following portal vein embolization

Background and Aim

Portal vein embolization (PVE) prior to hepatic resection reduces the risk of hepatic insufficiency in the postoperative period by redistributing blood from the embolized unhealthy liver to the healthy liver, termed the functional liver remnant (FLR). A retrospective analysis of liver volumes after embolization in a single institution was performed to identify change in volume of the FLR and determine factors affecting this change.

Methods

Between 2013 and 2015, 21 patients undergoing PVE followed by hepatic resection for varied indications (colorectal metastases, hepatocellular carcinoma, cholangiocarcinoma, etc.) were included in this study. n-butyl cyanoacrylate glue diluted with Lipiodol (35-45% strength) along with 75-100 μm of polyvinyl alcohol particles were used for embolization. Liver volumetric determination was performed before and after PVE and volume changes in the FLR were analyzed. Biochemical factors and factors affecting FLR hypertrophy were also analyzed.

Results

Majority of the patients (n = 18) underwent right-lobe embolization. All were performed using the ipsilateral approach. No major complications occurred with only one patient developing post-procedural ascites requiring percutaneous draining. A significant increase in the mean volume of the FLR by 63.7% ± 91.6%, P = 0.001 was noted after PVE. The FLR/total liver volume (TLV) increased significantly by 17% ± 18%. No significant demographic factors affected FLR hypertrophy and no significant biochemical changes were noted. Thirteen patients were successfully operated on after embolization.

Conclusions

PVE is effective in inducing significant hypertrophy of the future FLR, prior to hepatic resection in our institution.

Impact of acute kidney injury after extended liver resections

BACKGROUND

Complex liver resection is a risk factor for the development of AKI, which is associated with increased morbidity and mortality. Aim of this study was to assess risk factors for acute kidney injury (AKI) and its impact on outcome for patients undergoing complex liver surgery.

METHODS

AKI was defined according to the KDIGO criteria. Primary endpoint was the occurrence of AKI after liver resection. Secondary endpoints were complications and mortality.

RESULTS

Overall, 146 patients undergoing extended liver resection were included in the study. The incidence of AKI was 21%. The incidence of chronic kidney disease (CKD) and hepatocellular carcinoma were significantly higher in patients with AKI. In the AKI group, the proportion of extended right hepatectomies was the highest (53%), followed by ALPPS (43%). Increased intraoperative blood loss, increased postoperative complications and perioperative mortality was associated with AKI. Besides age and CKD, ALPPS was an independent risk factor for postoperative AKI. A small future liver remnant seemed to increase the risk of AKI in patients undergoing ALPPS.

CONCLUSION

Following extended liver resection, AKI is associated with an increased morbidity and mortality. ALPPS is a major independent risk factor for the development of AKI and a sufficient future liver remnant could avoid postoperative AKI.

Analysis of factors associated with discrepancies between predicted and observed liver weight in liver transplantation

BACKGROUND

Even using predictive formulas based on anthropometrics in about 30% of subjects, liver weight (LW) cannot be predicted with a ≤20% margin of error. We aimed to identify factors associated with discrepancies between predicted and observed LW.

METHODS

In 500 consecutive liver grafts, we tested LW predictive performance using 17 formulas based on anthropometric characteristics. Hashimoto's formula (961.3 × BSA_D-404.8) was associated with the lowest mean absolute error and used to predict LW for the entire cohort. Clinical factors associated with a ≥20% margin of error were identified in a multivariable analysis after propensity score matching (PSM) of donors with similar anthropometric characteristics.

RESULTS

The total LW was underestimated with a ≥20% margin of error in 53/500 (10.6%) donors and overestimated in 62/500 (12%) donors. After PSM analysis, ages ≥ 65, (OR = 3.21; CI95% = 1.63-6.31; P = .0007), age ≤ 30 years, (OR = 2.92; CI95% = 1.15-7.40; P = .02), and elevated gamma-glutamyltransferase (GGT) levels (OR = 0.98; CI95% = 0.97-0.99; P = .006), influenced the risk of LW overestimation. Age ≥ 65 years, (OR = 5.98; CI95% = 2.28-15.6; P = .0002), intensive care unit (ICU) stay with ventilation > 7 days, (OR = 0.32; CI95% = 0.12-0.85; P = .02) and waist circumference increase (OR = 1.02; CI95% = 1.00-1.04; P = .04) were factors associated with LW underestimation.

CONCLUSIONS

Increased waist circumference, age, prolonged ICU stay with ventilation, elevated GGT were associated with an increase in the margin of error in LW prediction. These factors and anthropometric characteristics could help transplant surgeons during the donor-recipient matching process.

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.

Ipsilateral access portal venous embolization (PVE) for preoperative hypertrophy exhibits low complication rates in Clavien-Dindo and CIRSE scales

Background

Portal venous embolization (PVE) is a minimal invasive preoperative strategy that aims to increase future liver remnant (FLR) in order to facilitate extended hemihepatectomy. We analyzed our data retrospectively regarding complications and degree of hypertrophy (DH).

Methods: 88 patients received PVE either by particles / coils (n = 77) or by glue / oil (n = 11), supported by 7 right hepatic vein embolizations (HVE) by coils or occluders. All complications were categorized by the Clavien- Dindo (CD) and the CIRSE classification.

Results

In 88 patients (median age 68 years) there was one intervention with a biliary leak and subsequent drainage (complication grade 3 CD, CIRSE 3), two with prolonged hospital stay (grade 2 CD, grade 3 CIRSE) and 13 complications grade 1 CD, but no complications of grade 4 or higher neither in Clavien- Dindo nor in CIRSE classification. The median relative increase in FLR was 47% (SD 35%). The mean pre-intervention standardized FLR rose from 23% (SD 10%) to a post-intervention standardized FLR of 32% (SD 12%). The degree of hypertrophy (DH) was 9,3% (SD 5,2%) and the kinetic growth rate (KGR) per week was 2,06 (SD 1,84).

Conclusion

PVE and, if necessary, additional sequential HVE were safe procedures with a low rate of complications and facilitated sufficient preoperative hypertrophy of the future liver remnant.

Evolutions in the Management of Hepatocellular Carcinoma over Last 4 Decades: An Analysis from the 100 Most Influential Articles in the Field

INTRODUCTION

Over the past 4 decades, the management of hepatocellular carcinoma (HCC) has changed dramatically. The publications that have had the most significant impact on HCC management have not been quantitatively analyzed. In this article, we analyzed the 100 most influential articles over the past 4 decades using bibliometric citation analysis to characterize the evolution in HCC treatment.

METHODS

The top-cited publications were identified and analyzed from the Clarivate Analytics Web of Science Core Collection database.

RESULTS

The 100 most cited articles were identified with an average of 738 citations (range: 349-6,799). There was an increase in the number of influential articles in the late 1990s, which was paralleled by an increase in reports focused on locoregional treatment of HCC. Most top 100 articles came from the USA (n = 35), followed by Italy (n = 28), mainland China (n = 26), and Japan (n = 24). The surgical management was the most studied topic (n = 33). The Annals of Surgery published the highest number of papers (n = 26) with 13,978 citations. While other 3 topics (surgical management, locoregional treatment, and outcome prediction) declined among publications beginning in the 2000s, there was an emergence of highly cited papers on targeted drugs and immune checkpoint inhibitors with a concomitant increase in the number of publications on systemic therapy.

CONCLUSIONS

Based on bibliometric analysis of the literature over the last 40 years, a comprehensive analysis of the most historically significant HCC management articles highlighted the key contributions made to the evolution and advancement of this specialist field. The data should provide clinicians and researchers insight into future directions relative to the advancement of HCC management.

Functional transition: Inconsistently parallel to the increase in future liver remnant volume after preoperative portal vein embolization

BACKGROUND

Preoperative portal vein embolization (PVE) is a widely used strategy to enable major hepatectomy in patients with insufficient liver remnant. PVE induces hypertrophy of the future liver remnant (FLR) and a shift of the functional reserve to the FLR. However, whether the increase of the FLR volume (FLRV) corresponds to the functional transition after PVE remains unclear.

AIM

To investigate the sequential relationship between the increase in FLRV and functional transition after preoperative PVE using 3-dimensional (3D) computed tomography (CT) and ^99mTc-galactosyl-human serum albumin (^99mTc-GSA) single-photon emission computed tomography (SPECT) fusion images.

METHODS

Thirty-three patients who underwent major hepatectomy following PVE at the Department of Gastroenterological Surgery I, Hokkaido University Hospital between October 2013 and March 2018 were enrolled. Three-phase dynamic multidetector CT and ^99mTc-GSA SPECT scintigraphy were performed at pre-PVE, and at 1 and 2 wk after PVE; 3D ^99mTc-GSA SPECT CT-fused images were constructed from the Digital Imaging and Communications in Medicine data using 3D image analysis system. Functional FLRV (FFLRV) was defined as the total liver volume × (FLR volume counts/total liver volume counts) on the 3D ^99mTc-GSA SPECT CT-fused images. The calculated FFLRV was compared with FLRV.

RESULTS

FFLRV increased by a significantly larger extent than FLRV at 1 and 2 wk after PVE (P < 0.01). The increase in FFLRV and FLRV was 55.1% ± 41.6% and 26.7% ± 17.8% (P < 0.001), respectively, at 1 wk after PVE, and 64.2% ± 33.3% and 36.8% ± 18.9% (P < 0.001), respectively, at 2 wk after PVE. In 3 of the 33 patients, FFLRV levels decreased below FLRV at 2 wk. One of the three patients showed rapidly progressive fatty changes in FLR. The biopsy at 4 wk after PVE showed macro- and micro-vesicular steatosis of more than 40%, which improved to 10%. Radical resection was performed at 13 wk after PVE. The patient recovered uneventfully without any symptoms of pos-toperative liver failure.

CONCLUSION

The functional transition lagged behind the increase in FLRV after PVE in some cases. Evaluating both volume and function is needed to determine the optimal timing of hepatectomy after PVE.

Utility of remnant liver volume for predicting posthepatectomy liver failure after hepatectomy with extrahepatic bile duct resection

BACKGROUND

Hepatectomy with extrahepatic bile duct resection is associated with a high risk of posthepatectomy liver failure (PHLF). However, the utility of the remnant liver volume (RLV) in cholangiocarcinoma has not been studied intensively.

METHODS

Patients who underwent major hepatectomy with extrahepatic bile duct resection between 2002 and 2018 were reviewed. The RLV was divided by body surface area (BSA) to normalize individual physical differences. Risk factors for clinically relevant PHLF were evaluated with special reference to the RLV/BSA.

RESULTS

A total of 289 patients were included. The optimal cut-off value for RLV/BSA was determined to be 300 ml/m2. Thirty-two patients (11.1 per cent) developed PHLF. PHLF was more frequent in patients with an RLV/BSA below 300 ml/m2 than in those with a value of 300 ml/m2 or greater: 19 of 87 (22 per cent) versus 13 of 202 (6.4 per cent) (P < 0.001). In multivariable analysis, RLV/BSA below 300 ml/m2 (P = 0.013), future liver remnant plasma clearance rate of indocyanine green less than 0.075 (P = 0.031), and serum albumin level below 3.5 g/dl (P = 0.015) were identified as independent risk factors for PHLF. Based on these risk factors, patients were classified into three subgroups with low (no factors), moderate (1-2 factors), and high (3 factors) risk of PHLF, with PHLF rates of 1.8, 14.8 and 63 per cent respectively (P < 0.001).

CONCLUSION

An RLV/BSA of 300 ml/m2 is a simple predictor of PHLF in patients undergoing hepatectomy with extrahepatic bile duct resection.

Portal vein embolization with ethylene-vinyl alcohol copolymer for contralateral lobe hypertrophy before liver resection: safety, feasibility and initial experience

Background

To report our preliminary experience with preoperative portal vein embolization (PVE) using liquid ethylene vinyl alcohol (EVOH) copolymer.

Methods

Retrospectively review of patients with primary or secondary liver malignancies scheduled for extensive hepatectomy after the induction of future liver remnant (FLR) hypertrophy by right or left PVE with EVOH as the only embolic agent between 2014 and 2018 at two academic centers. Cross-sectional imaging liver volumetry data obtained before and 3-6 weeks after PVE were used to assess the FLR volume (FLRV) increase, degree of FLR hypertrophy and the FLR kinetic growth rate (KGR).

Results

Twenty-six patients (17 males; mean age, 58.7±11 years; range, 32-79 years) were included. The technical and clinical success rate was 100%. PVE produced adequate FLR hypertrophy in all patients. Embolization occurred in all targeted portal branches and in no non-target vessels. The %FLRV increased by 52.9%±32.5% and the degree of FLR hypertrophy was 16.7%±6.8%. The KGR was 4.4%±2.0% per week. Four patients experience minor complications after PVE which resolved with symptomatic treatment. The resection rate was 84.5%. One patient died during surgery for reasons unrelated to PVE.

Conclusions

Preoperative PVE with EVOH copolymer is feasible, safe, and effective in inducing FLR hypertrophy.

Evaluating dose constraints for radiation induced liver damage following magnetic resonance image guided Stereotactic Body radiotherapy

This study reports dose corresponding to visible radiation induced liver damage following Stereotactic Body Radiation Therapy (SBRT) for liver metastasis, and the optimal time for follow up scans using post radiation imaging. Diagnostic magnetic resonance scans of nine patients treated with liver SBRT using a 0.35 T MRI-guided radiotherapy system were analyzed. The dice coefficients between the region of visible liver damage and the delivered dose were calculated. A median dose of 35 Gy correlated most closely with the visible radiation induced liver damage. We compared scans over two to nine months and observed maximal dice coefficients at two to five months post radiation. We have presented a new method for developing treatment planning guidelines for liver SBRT.

A novel model for predicting posthepatectomy liver failure based on liver function and degree of liver resection in patients with hepatocellular carcinoma

BACKGROUND

The permissible liver resection rate for preventing posthepatectomy liver failure (PHLF) remains unclear. We aimed to develop a novel PHLF-predicting model and to strategize hepatectomy for hepatocellular carcinoma (HCC).

METHODS

This retrospective study included 335 HCC patients who underwent anatomical hepatectomy at eight institutions between 2013 and 2017. Risk factors, including volume-associated liver-estimating parameters, for PHLF grade B-C were analyzed in a training set (n = 122) via multivariate analysis, and a PHLF prediction model was developed. The utility of the model was evaluated in a validation set (n = 213).

RESULTS

Our model was based on the three independent risk factors for PHLF identified in the training set: volume-associated indocyanine green retention rate at 15 min, platelet count, and prothrombin time index (the VIPP score). The areas under the receiver operating characteristic curve of the VIPP scores for severe PHLF in the training and validation sets were 0.864 and 0.794, respectively. In both sets, the VIPP score stratified patients at risk for severe PHLF, with a score of 3 (specificity, 0.92) indicating higher risk.

CONCLUSION

Our model facilitates the selection of the appropriate hepatectomy procedure by providing permissible liver resection rates based on VIPP scores.

Alteration of FBXW7 is Associated with Worse Survival in Patients Undergoing Resection of Colorectal Liver Metastases

BACKGROUND

For patients undergoing resection of colorectal liver metastases (CLMs), the prognostic role of somatic gene alterations is increasingly recognized. F-box/WD repeat-containing protein 7 (FBXW7) is a tumor suppressor gene found in approximately 10% of patients with colorectal cancer. The aim of this study is to assess the association of FBXW7 with overall survival after CLM resection.

METHODS

Patients who underwent initial CLM resection during 2001-2016 and had genetic sequencing data were studied. Risk factors for overall survival (OS) were evaluated with Cox proportional hazards models using backward elimination.

RESULTS

Of 2045 patients who underwent CLM resection during the study period, 476 were included. The majority (90.5%) underwent prehepatectomy chemotherapy. A total of 27 patients (5.7%) had FBXW7 alteration, along with 240 (50.4%) RAS, 337 (70.8%) TP53, 51 (10.7%) SMAD4, and 27 (5.7%) BRAF. Cox proportional hazards model analyses including 5 somatic gene alteration status and 12 clinicopathologic factors revealed FBXW7(hazard ratio [HR] 1.99, P = 0.015), BRAF (HR 2.47, P = 0.023), RAS (HR 2.42, P < 0.001), TP53 (HR 2.00, P < 0.001), and SMAD4 alterations (HR 1.90, P = 0.004) as significantly associated with OS, together with three clinicopathologic factors, prehepatectomy chemotherapy > 6 cycles (HR 1.51, P = 0.021), number of CLM (HR 1.05, P = 0.007), and largest liver metastasis diameter (HR 1.07, P = 0.023). The covariate-adjusted 5-year OS was significantly lower in patients with FBXW7 alteration than in patients with FBXW7 wild-type (40.4% vs.59.4%, P = 0.015).

CONCLUSIONS

FBXW7 alterations are associated with worse survival after CLM resection. The information on multiple somatic gene alterations is imperative for risk stratification and patient selection for CLM resection.

The role of associating liver partition and portal vein ligation for staged hepatectomy in the management of patients with colorectal liver metastasis

Associating liver partition and portal vein ligation for staged hepatectomy (ALPPS) approach emerged as a promising surgical strategy for rapid and large hypertrophy of the future liver remnant (FLR) when a major liver resection is necessary. Colorectal liver metastasis (CRLM) is their main indication. However, the promising results published so far, are very difficult to interpret since they usually focus on the technique and not on the underlying disease. Moreover, they are usually made up of complex populations, which received different chemotherapy schemes, with the ALPPS technical variations implemented over time and without consistent long-term follow-up results as well. Whereby, its role in CRLM should be analyzed as carefully as possible to indicate and select the best candidates who will benefit the most from this approach. We conducted a computerized search using PubMed and Google Scholar for reports published so far, using mesh headings and keywords related to the ALPPS and CRLM.

Personalized computed tomography - Automated estimation of height and weight of a simulated digital twin using a 3D camera and artificial intelligence

PURPOSE

 The aim of this study was to develop an algorithm for automated estimation of patient height and weight during computed tomography (CT) and to evaluate its accuracy in everyday clinical practice.

MATERIALS AND METHODS

 Depth images of 200 patients were recorded with a 3D camera mounted above the patient table of a CT scanner. Reference values were obtained using a calibrated scale and a measuring tape to train a machine learning algorithm that fits a patient avatar into the recorded patient surface data. The resulting algorithm was prospectively used on 101 patients in clinical practice and the results were compared to the reference values and to estimates by the patient himself, the radiographer and the radiologist. The body mass index was calculated from the collected values for each patient using the WHO formula. A tolerance level of 5 kg was defined in order to evaluate the impact on weight-dependent contrast agent dosage in abdominal CT.

RESULTS

 Differences between values for height, weight and BMI were non-significant over all assessments (p > 0.83). The most accurate values for weight were obtained from the patient information (R² = 0.99) followed by the automated estimation via 3D camera (R² = 0.89). Estimates by medical staff were considerably less precise (radiologist: R² = 0.78, radiographer: R² = 0.77). A body-weight dependent dosage of contrast agent using the automated estimations matched the dosage using the reference measurements in 65 % of the cases. The dosage based on the medical staff estimates would have matched in 49 % of the cases.

CONCLUSION

 Automated estimation of height and weight using a digital twin model from 3D camera acquisitions provide a high precision for protocol design in computer tomography.

KEY POINTS

  · Machine learning can calculate patient-avatars from 3D camera acquisitions.. · Height and weight of the digital twins are comparable to real measurements of the patients.. · Estimations by medical staff are less precise.. · The values can be used for calculation of contrast agent dosage..

CITATION FORMAT

· Geissler F, Heiß R, Kopp M et al. Personalized computed tomography - Automated estimation of height and weight of a simulated digital twin using a 3D camera and artificial intelligence. Fortschr Röntgenstr 2021; 193: 437 - 445.

The role of hepatobiliary scintigraphy combined with spect/ct in predicting severity of liver failure before major hepatectomy: a single-center pilot study

Hepatobiliary scintigraphy (HBS) has been demonstrated to predict post-hepatectomy liver failure (PHLF). However, existing cutoff values for future liver remnant function (FLR-F) were previously set according to the “50–50 criteria” PHLF definition. Methods of calculation and fields of application in liver surgery have changed in the meantime. The aim of this study was to demonstrate the role of HBS combined with single photon emission computed tomography (SPECT/CT) in predicting severity of PHLF, according to the International Study Group of Liver Surgery (ISGLS). All patients submitted to major hepatectomy with preoperative HBS-SPECT/CT between November 2016 and December 2019, were analyzed. Patients were resected according to hepatic volumetry. Receiver operating characteristic (ROC) curve analysis was performed to identify cutoffs of FLR function for predicting PHLF according to ISGLS definition and grading. Of the 38 patients enrolled, 26 were submitted to one-stage hepatectomy (living liver donors = 4) and 12 to two-stage procedures (portal vein embolization = 4, ALPPS = 8). Overall, 18 patients developed PHLF according to ISGLS criteria: 12 of grade A (no change in the patient’s clinical management) and 6 of grade B (change in clinical management). ROC analysis established increasingly higher cutoffs of FLR-F for predicting PHLF according to the “50–50 criteria”, ISGLS grade B and ISGLS grade A/B, respectively. HBS with SPECT/CT may help to assess severity of PHLF following major hepatectomy. Prospective multicenter trials are needed to confirm the effective role of HBS-SPECT/CT in liver surgery.

Surgical Resection: Old Dog, Any New Tricks?

Patients with hepatocellular carcinoma (HCC) have many treatment options. For patients with surgical indication, consideration of future liver remnant and the surgical complexity of the procedure is essential. A new 3-level complexity classification categorizing 11 liver resection procedures predicts surgical complexity and postoperative morbidity better than reported classifications. Preoperative portal vein embolization can mitigate the risk of hepatic insufficiency. For small HCCs, both liver resection and ablation are effective. New medical treatment options are promising and perioperative use of these drugs may further improve outcomes for patients undergoing liver resection and lead to changes in current treatment guidelines.

Assessment of Radiation Dose Delivered and Volume Measurement By Low- and High-Dose Diagnostic Computed Tomography: Anthropomorphic Liver Phantom Study

Aim:

Liver volume measurement is a mandatory test before measure liver surgeries and transplantation. We aimed a study on the difference in volume measurement and radiation dose to an anthropomorphic liver phantom using high-dose and low-dose diagnostic computed tomography (CT).

Materials and Methods:

Several measurements of the manual total volume measurement done on an anthropomorphic liver phantom mounted with thermoluminescent dosimeter. We exposed the phantom with diagnostic CT, low-dose CT, and a low-dose CT with copper filter.

Results:

Phantom underwent ten scanning for each exposure. There was no significant difference in the total volume measurement in comparison to the phantom volume. The volume of phantom measured by low-dose CT, low-dose CT with copper phantom, and high-dose CT were 1869 ± 18 cm³, 1852 ± 24 cm³, and 1908 ± 12 cm³, (P = 0.3), respectively. However, the radiation dose delivered was significantly different (1.54 mGy, 0.77 mGy, and 5.84 mGy [P = 0.001], respectively).

Conclusion:

Total liver volume measurement provides essential clinical information in several clinical conditions. We recommended that the volume measured by a low-dose CT has an excellent correlation with the diagnostic quality CT and should be a routine in the routine clinical practice. CT volumetry achieves the same result while using very less radiation exposure. It may also be used with functional imaging to give complete information.

Minimally Invasive Stage 1 to Protect Against the Risk of Liver Failure: Results from the Hepatocellular Carcinoma Series of the Associating Liver Partition and Portal Vein Ligation for Staged Hepatectomy Italian Registry

Introduction: Associating liver partition and portal vein ligation for staged hepatectomy (ALPPS) has been described to treat hepatocellular carcinoma (HCC) but burdened, in its pioneering phase, by high morbidity and mortality. With the advent of minimally invasive (MI) techniques in liver surgery, surgical complications, including posthepatectomy liver failure (PHLF), have been dramatically reduced. The primary endpoint of this study was to compare the short-term outcomes of MI- versus open-ALPPS for HCC, with specific focus on PHLF. Methods: Data of patients submitted to ALPPS for HCC between 2012 and 2020 were identified from the ALPPS Italian Registry. Patients receiving an MI Stage 1 (MI-ALPPS) constituted the study group, whereas the patients who received an open Stage 1 (open-ALPPS) constituted the control group. Results: Sixty-six patients were enrolled from 12 Italian centers. Stage 1 of ALPPS was performed in 14 patients using an MI approach (21.2%). MI-ALPPS patients were discharged after Stage 1 at a significantly higher rate compared with open-ALPPS (78.6% versus 9.6%, P < .001). After Stage 2, major morbidity after MI-ALPPS was 8.3% compared with 28.6% reported after open-ALPPS. Mortality was nil after MI-ALPPS. Length of hospital stay was significantly shorter in MI-ALPPS (12 days versus 22 days, P < .001). Univariate logistic regression analysis (Firth method) found that both MI-ALPPS (odds ratio [OR] = 0.05, P = .040) and partial parenchymal transection (OR = 0.04, P = .027) were protective against PHLF. Conclusion: This national multicenter study showed that a less invasive approach to ALPPS first stage was associated with a lower overall risk of PHLF.

Issues to be considered to address the future liver remnant prior to major hepatectomy

An accurate preoperative evaluation of the hepatic function and application of portal vein embolization in selected patients have helped improve the safety of major hepatectomy. In planning major hepatectomy, however, several issues remain to be addressed. The first is which cut-off values for serum total bilirubin level and prothrombin time should be used to define post-hepatectomy liver failure. Other issues include what minimum future liver remnant (FLR) volume is required; whether the total liver volume measured using computed tomography or the standard liver volume calculated based on the body surface area should be used to assess the adequacy of the FLR volume; whether there is a discrepancy between the FLR volume and function during the recovery period after portal vein embolization or hepatectomy; and how best the function of a specific FLR can be assessed. Various studies concerning these issues have been reported with controversial results. We should also be aware that different strategies and management are required for different types of liver damage, such as cirrhosis in hepatocellular carcinoma, cholangitis in biliary tract cancer, and chemotherapy-induced hepatic injury.

Simultaneous portal and hepatic vein embolization before major liver resection

Background

Regenerative liver surgery expands the limitations of technical resectability by increasing the future liver remnant (FLR) volume before extended resections in order to avoid posthepatectomy liver failure (PHLF). Portal vein rerouting with ligation of one branch of the portal vein bifurcation (PVL) or embolization (PVE) leads to a moderate liver volume increase over several weeks with a clinical dropout rate of 20–40%, mostly due to tumor progression during the waiting period. Accelerated liver regeneration by the Associating Liver Partition and Portal vein Ligation for Staged hepatectomy (ALPPS) was poised to overcome this limitation by reduction of the waiting time, but failed due increased perioperative complications. Simultaneous portal and hepatic vein embolization (PVE/HVE) is a novel minimal invasive way to induce rapid liver growth without the need of two surgeries.

Purpose

This article summarizes published results of PVE/HVE and analyzes what is known about its efficacy to achieve resection, safety, and the volume changes induced.

Conclusions

PVE/HVE holds promise to induce accelerated liver regeneration in a similar safety profile to PVE. The demonstrated accelerated hypertrophy may increase resectability. Randomized trials will have to compare PVE/HVE and PVE to determine if PVE/HVE is superior to PVE.

Case report of Tourniquet ALPPS and simultaneous sleeve gastrectomy: A valuable association to achieve an adequate future liver remnant in obese patients

INTRODUCTION

Obesity represents a risk factor in case of major hepatectomy, because the future liver remnant (FLR) must be proportional with body weight. To avoid post-hepatectomy liver failure, and further increase the ratio between FLR and body weight, we performed a bariatric procedure in the first stage of the ALPPS technique.

PATIENT CONCERNS

Fifty-four-year-old woman, with morbid obesity (BMI 58.5) and type II diabetes mellitus, was scheduled for a major hepatectomy due to multiple colorectal liver metastases DIAGNOSIS:: Six months before, the patient was diagnosed with colorectal cancer and synchronous liver metastases. She was initially treated with sigmoidectomy and chemotherapy. After partial response of the liver metastases, we considered a liver resection but the FLR was very low, especially in relation to her BMI.

INTERVENTION

We planned a novel approach and, for the first time, we performed a sleeve gastrectomy during the first stage of Tourniquet ALPPS (T-ALPPS). After achieving an adequate FLR, we successfully completed the major hepatectomy during the second stage of T-ALPPS.

OUTCOME

The association between sleeve gastrectomy and T-ALPPS produced an increase of FLR/body weight ratio up to 0.8 that allowed completing a right trisectionectomy in the second stage of ALPPS. The major hepatectomy was performed without severe complications, and several months after surgery the patient is still alive without any recurrence Conclusion: Despite obesity represents a risk factor involved in the carcinogenesis, the role of the bariatric surgery in the oncological setting is not well established. In this clinical case, we benefited from the weight loss produced by bariatric surgery combined with an effective hypertrophy technique and chemotherapy. These findings suggest that bariatric surgery could be useful for obese patients with liver malignancy and need for extended hepatectomy.

MRI-guided adaptive radiotherapy for liver tumours: visualising the future

MRI-guided radiotherapy is a novel and rapidly evolving technology that might enhance the risk-benefit ratio. Through direct visualisation of the tumour and the nearby healthy tissues, the radiation oncologist can deliver highly accurate treatment even to mobile targets. Each individual treatment can be customised to changing anatomy, potentially reducing the risk of radiation-related toxicities while simultaneously increasing the dose delivered to the tumour. MRI-guided radiotherapy offers a new tool for the radiation oncologist, and creates an opportunity to achieve durable local control of liver tumours that might not otherwise be possible. Future work will allow us to expand the population eligible for curative-intent radiotherapy, optimise and customise radiation doses to specific tumours, and hopefully create opportunities for improving outcomes through machine learning and radiomics-based approaches. This Review outlines the current and future applications for MRI-guided radiotherapy with respect to metastatic and primary liver cancers.

Simulated model of RAPID concept: highlighting innate inflammation and liver regeneration

Background

The resection and partial liver segment II/III transplantation with delayed total hepatectomy (RAPID) concept is a novel transplantation technique for removal of non‐resectable liver tumours. The aim of this study was to establish a simulated RAPID model to explore the mechanism involved in the liver regeneration.

Methods

A RAPID model was created in rats involving cold ischaemia and reperfusion of the selected future liver remnant (FLR), portal vein ligation, followed by resection of the deportalized lobes in a second step. Histology, liver regeneration and inflammatory markers in RAPID‐treated rats were compared with those in controls that underwent 70 per cent hepatectomy with the same FLR size. The effects of interleukin (IL) 6 and macrophage polarization on hepatocyte viability were evaluated in an in vitro co‐culture system of macrophages and BRL hepatocytes.

Results

The survival rate in RAPID and control hepatectomy groups was 100 per cent. The regeneration rate was higher in the RAPID‐treated rats, with higher levels of IL‐6 and M1 macrophage polarization (P < 0·050). BRL hepatocytes co‐cultured with M1 macrophages showed a higher proliferation rate through activation of the IL‐6/signal transducer and activator of transcription 3/extracellular signal‐regulated kinase pathway. This enhancement of proliferation was inhibited by tocilizumab or gadolinium trichloride (P < 0·050).

Conclusion

The surgical model provides a simulation of RAPID that can be used to study the liver regeneration profile.

Liver resection in Cirrhotic liver: Are there any limits?

Liver resection remains one of the most technically challenging surgical procedure in abdominal surgery due to the complex anatomical arrangement in the liver and its rich blood supply that constitutes about 20% of the cardiac output per cycle. The challenge for resection in cirrhotic livers is even higher because of the impact of surgical stress and trauma imposed on borderline liver function and the impaired ability for liver regeneration in cirrhotic livers. Nonetheless, evolution and advancement in surgical techniques as well as knowledge in perioperative management of liver resection has led to a substantial improvement in surgical outcome in recent decade. The objective of this article was to provide updated information on the recent developments in liver surgery, from preoperative evaluation, to technicality of resection, future liver remnant augmentation and finally, postoperative management of complications.

Comprehensive Complication Index Validates Improved Outcomes Over Time Despite Increased Complexity in 3707 Consecutive Hepatectomies

OBJECTIVE

The aim of this study was to evaluate trends over time in perioperative outcomes for patients undergoing hepatectomy.

BACKGROUND

As perioperative care and surgical technique for hepatectomy have improved, the indications for and complexity of liver resections have evolved. However, the resulting effect on the short-term outcomes over time has not been well described.

METHODS

Consecutive patients undergoing hepatectomy during 1998 to 2015 at 1 institution were analyzed. Perioperative outcomes, including the comprehensive complication index (CCI), were compared between patients who underwent hepatectomy in the eras 1998 to 2003, 2004 to 2009, and 2010 to 2015.

RESULTS

The study included 3707 hepatic resections. The number of hepatectomies increased in each era (794 in 1998 to 2003, 1402 in 2004 to 2009, and 1511 in 2010 to 2015). Technical complexity increased over time as evidenced by increases in the rates of major hepatectomy (20%, 23%, 30%, P < 0.0001), 2-stage hepatectomy (0%, 3%, 4%, P < 0.001), need for portal vein embolization (5%, 9%, 9%, P = 0.001), preoperative chemotherapy for colorectal liver metastases (70%, 82%, 89%, P < 0.001) and median operative time (180, 175, 225 minutes, P < 0.001). Significant decreases over time were observed in median blood loss (300, 250, 200 mL, P < 0.001), transfusion rate (19%, 15%, 5%, P < 0.001), median length of hospitalization (7, 7, 6 days, P < 0.001), rates of CCI ≥26.2 (20%, 22%, 16%, P < 0.001) and 90-day mortality (3.1%, 2.6%, 1.3%, P < 0.01). On multivariable analysis, hepatectomy in the most recent era 2010 to 2015 was associated with a lower incidence of CCI ≥26.2 (odds ratio 0.7, 95% confidence interval 0.6-0.8, P < 0.0001).

CONCLUSION

Despite increases in complexity over an 18-year period, continued improvements in surgical technique and perioperative outcomes yielded a resultant decrease in CCI in the most current era.

Hallmarks of postoperative liver regeneration: An updated insight on the regulatory mechanisms

Performance and advances in liver surgery makes remarkable progress of the understanding of liver regeneration. Liver regeneration after liver resection has been widely researched, and the underlying mechanism mostly concerns proliferation of hepatocytes and the influence by inflammation through activation of Kupffer cells and the other parenchymal cells, the second regenerative pathway by hepatic progenitor cells (HPCs), inducing angiogenesis, remodeling of a extracellular matrix (ECM), and termination mechanisms. New clinical surgeries and the updated multiomics analysis are exploiting the remarkable progress, especially in immune regulation and metabolic process of two emerging hallmarks. This review briefly represents a systemic outline of eight hallmarks, including hepatocyte proliferation, contribution of hepatic progenitor cells, inducing angiogenesis, reprogramming of the extracellular matrix, apoptosis and termination of proliferation, inflammation, immune and metabolic regulation, which are set as organizing characteristics of postoperative liver regeneration and future directions of refining treatment targets.