[Ablation of liver tumors : From pre-interventional imaging to post-interventional assessment]. / Ablation von Lebertumoren : Von der prä-interventionellen Bildgebung bis zur post-interventionellen Beurteilung.

The aim of this article is to provide an overview on the most frequently applied image-guided, percutaneous, local ablative techniques for treatment of primary and secondary liver tumors. The technical procedures of microwave ablation (MWA) and radiofrequency ablation (RFA) are presented. The pre-interventional diagnostics, indications and feasibility are also discussed, taking the current national guidelines into consideration. Finally, treatment outcomes and recommendations on post-interventional imaging following local tumor ablation are presented.

Abbreviated MRI Protocols in the Abdomen and Pelvis.

Abbreviated MRI (AMRI) protocols rely on the acquisition of a limited number of sequences tailored to a specific question. The main objective of AMRI protocols is to reduce exam duration and costs, while maintaining an acceptable diagnostic performance. AMRI is of increasing interest in the radiology community; however, challenges limiting clinical adoption remain. In this review, we will address main abdominal and pelvic applications of AMRI in the liver, pancreas, kidney, and prostate, including diagnostic performance, pitfalls, limitations, and cost effectiveness will also be discussed. Level of Evidence: 3 Technical Efficacy Stage: 3.

Consensus report from the 10th Global Forum for Liver Magnetic Resonance Imaging: developments in HCC management.

The 10th Global Forum for Liver Magnetic Resonance Imaging (MRI) was held as a virtual 2-day meeting in October 2021, attended by delegates from North and South America, Asia, Australia, and Europe. Most delegates were radiologists with experience in liver MRI, with representation also from specialists in liver surgery, oncology, and hepatology. Presentations, discussions, and working groups at the Forum focused on the following themes: • Gadoxetic acid in clinical practice: Eastern and Western perspectives on current uses and challenges in hepatocellular carcinoma (HCC) screening/surveillance, diagnosis, and management • Economics and outcomes of HCC imaging • Radiomics, artificial intelligence (AI) and deep learning (DL) applications of MRI in HCC. These themes are the subject of the current manuscript. A second manuscript discusses multidisciplinary tumor board perspectives: how to approach early-, mid-, and late-stage HCC management from the perspectives of a liver surgeon, interventional radiologist, and oncologist (Taouli et al, 2023). Delegates voted on consensus statements that were developed by working groups on these meeting themes. A consensus was considered to be reached if at least 80% of the voting delegates agreed on the statements. CLINICAL RELEVANCE STATEMENT: This review highlights the clinical applications of gadoxetic acid-enhanced MRI for liver cancer screening and diagnosis, as well as its cost-effectiveness and the applications of radiomics and AI in patients with liver cancer. KEY POINTS: • Interpretation of gadoxetic acid-enhanced MRI differs slightly between Eastern and Western guidelines, reflecting different regional requirements for sensitivity vs specificity. • Emerging data are encouraging for the cost-effectiveness of gadoxetic acid-enhanced MRI in HCC screening and diagnosis, but more studies are required. • Radiomics and artificial intelligence are likely, in the future, to contribute to the detection, staging, assessment of treatment response and prediction of prognosis of HCC-reducing the burden on radiologists and other specialists and supporting timely and targeted treatment for patients.

Consensus report from the 10th global forum for liver magnetic resonance imaging: multidisciplinary team discussion.

The 10th Global Forum for Liver Magnetic Resonance Imaging was held in October 2021. The themes of the presentations and discussions at this Forum are described in detail in the review by Taouli et al (2023). The focus of this second manuscript developed from the Forum is on multidisciplinary tumor board perspectives in hepatocellular carcinoma (HCC) management: how to approach early-, mid-, and late-stage management from the perspectives of a liver surgeon, an interventional radiologist, and an oncologist. The manuscript also includes a panel discussion by multidisciplinary experts on three selected cases that explore challenging aspects of HCC management. CLINICAL RELEVANCE STATEMENT: This review highlights the importance of a multidisciplinary team approach in liver cancer patients and includes the perspectives of a liver surgeon, an interventional radiologist, and an oncologist, including illustrative case studies. KEY POINTS: • A liver surgeon, interventional radiologist, and oncologist presented their perspectives on the treatment of early-, mid-, and late-stage HCC. • Different perspectives on HCC management between specialties emphasize the importance of multidisciplinary tumor boards. • A multidisciplinary faculty discussed challenging aspects of HCC management, as highlighted by three case studies.

Evaluation of tissue shrinkage after CT-guided microwave ablation in patients with liver malignancies using Jacobian determinant.

PURPOSE: To assess short-term tissue shrinkage in patients with liver malignancies undergoing computed tomography (CT)-guided microwave ablation (MWA) using Jacobian determinant (JD). MATERIALS AND METHODS: Twenty-nine patients with 29 hepatic malignancies (primary n = 24; metastases n = 5; median tumor diameter 18 mm) referred to CT-guided MWA (single position; 10 min, 100 W) were included in this retrospective IRB-approved study, after exclusion of five patients. Following segmentation of livers and tumors on pre-interventional images, segmentations were registered on post-interventional images. JD mapping was applied to quantify voxelwise tissue volume changes after MWA. Percentual volume changes were evaluated in the ablated tumor, a 5-cm tumor perimeter and in the whole liver and compared in different clinical conditions (tumor entity: primary vs. secondary; tumor location: subcapsular vs. non-subcapsular; tumor volume: >/<6 ml: cirrhosis: yes vs. no; prior chemotherapy: yes vs. no using Shapiro-Wilk, χ2 and Wilcoxon rank sum tests, respectively (with p < 0.05 deemed significant). RESULTS: Tissue volume change was 0.6% in the ablated tumor, 1.6% in the 5-cm perimeter and 0.3% in the whole liver. Shrinkage in the ablated tumor was pronounced in non-subcapsular located tumors, whereas tissue expansion was noted in subcapsular tumors (median -3.5 vs. 1.1%; p = 0.0195). Shrinkage in the whole liver was higher in tumor volumes >6ml, compared with smaller tumors, in which tissue expansion was noted (median -1.0 vs. 2.5%; p = 0.002). Other clinical conditions had no significant influence on the extent of tissue shrinkage (p > 0.05). CONCLUSION: 3D Jacobian analysis shows that hepatic tissue deformation following MWA is most pronounced in a 5-cm area surrounding the treated tumor. Tumor location and tumor volume may have an impact on the extent of tissue shrinkage which may affect estimation of the safety margin.

Reporting standards for primary sclerosing cholangitis using MRI and MR cholangiopancreatography: guidelines from MR Working Group of the International Primary Sclerosing Cholangitis Study Group.

Primary sclerosing cholangitis (PSC) is a chronic inflammatory disorder affecting the bile ducts and is characterized by biliary strictures, progressive liver parenchymal fibrosis, and an increased risk of hepatobiliary malignancies primarily cholangiocarcinoma (CCA). PSC may lead to portal hypertension, liver decompensation, and liver failure with the need for liver transplantation. Magnetic resonance imaging (MRI)/magnetic resonance cholangiopancreatography (MRCP) are considered the imaging standard for diagnosis and follow-up in patients with PSC. Currently, there are no universally accepted reporting standards and definitions for MRI/MRCP features. Controversies exist about the definition of a high-grade stricture and there is no widely agreed approach to their management. The members of the MRI working group of the International Primary Sclerosing Cholangitis Study Group (IPSCSG) sought to define terminologies and reporting standards for describing MRI/MRCP features that would be applied to diagnosis and surveillance of disease progression, and potentially for evaluating treatment response in clinical trials. In this extensive review, the technique of MRI/MRCP and assessment of image quality for the evaluation of PSC is briefly described. The definitions and terminologies for severity and length of strictures, duct wall thickening and hyperenhancement, and liver parenchyma signal intensity changes are outlined. As CCA is an important complication of PSC, standardized reporting criteria for CCA developing in PSC are summarized. Finally, the guidelines for reporting important changes in follow-up MRI/MRCP studies are provided. KEY POINTS: • Primary sclerosing cholangitis is a chronic inflammatory disorder affecting the bile ducts, causing biliary strictures and liver fibrosis and an increased risk of cholangiocarcinoma. • This consensus document provides definitions and suggested reporting standards for MRI and MRCP features of primary sclerosing cholangitis, which will allow for a standardized approach to diagnosis, assessment of disease severity, follow-up, and detection of complications. • Standardized definitions and reporting of MRI/MRCP features of PSC will facilitate comparison between studies, promote longitudinal assessment during management, reduce inter-reader variability, and enhance the quality of care and communication between health care providers.

Cross-insitutional standardization of imaging protocols - A pilot study within the scope of the Comprehensive Cancer Center Lower Saxony. / Standortübergreifende Standardisierung von Untersuchungsprotokollen ­ eine Pilotstudie im Rahmen des Comprehensive Cancer Centers Niedersachen.

PURPOSE: Cross-institutional establishment of standardized protocols for CT and MR imaging of primary liver and pancreas tumors in an oncological center. MATERIALS AND METHODS: This prospective dual-institution study was approved by the local IRBs. Minimum requirements (phases, sequences, slice thickness) for imaging of primary liver and pancreas tumors were defined and implemented at both sites. Between 06/19 and 08/19 in-house examinations were evaluated in terms of compliance with defined protocols and image quality. In addition, extramural examinations that were demonstrated at interdisciplinary tumor board meetings in the same study period were reviewed. Results were analyzed by means of descriptive statistics, and differences between centers, modalities and organs assessed (Fisher-exact Test, p < 0.05 deemed significant). RESULTS: 480 data sets (397 internal, 83 extramural) were included in this study and analyzed. Overall protocol compliance for in-house examinations was 93.5 % (371/397 datasets), without statistical significant difference between the two institutions (p = 0.0615). External studies met minimum requirements in 48.2 % (40/83 datasets). Regarding in-house imaging, significant differences were observed between CT of the liver and the pancreas (p < 0.05) and between CT and MRI of the pancreas (p < 0.05). CONCLUSION: As demonstrated in this pilot project, cross-institutional establishment of standardized imaging protocols is feasible with a compliance rate of more than 90 %. Standardized imaging protocols may serve as a quality indicator in oncological imaging, and over time, improve cross-institutional patient care. KEY POINTS: · Cross-institutional establishment of standardized imaging protocols is feasible with high compliance.. · Standards may serve as a quality indicator in oncological imaging.. · In perspective, cross-institutional patient care may be improved.. CITATION FORMAT: · Römermann I, Al-Bourini O, Seif Amir Hosseini A et al. Cross-insitutional standardization of imaging protocols - A pilot study within the scope of the Comprehensive Cancer Center Lower Saxony. Fortschr Röntgenstr 2021; 193: 410 - 416.

Abdominal Surgery in Patients with Ventricular Assist Devices: a Single-Center Report.

This study was performed to evaluate the incidence and outcome of patients with ventricular assist devices (VADs) undergoing abdominal surgery at our institution. A total of 604 adult patients who underwent VAD implantation between February 2004 and February 2018 were analyzed retrospectively with a median follow-up time of 66 (6-174) months. Thirty-nine patients (6.5%) underwent abdominal surgery. Elective surgical procedures were performed in 22 patients (56.4%), mainly for abdominal wall hernia repairs, partial colectomies, and cholecystectomies. Early after elective abdominal surgery no patient died, resulting in a median survival of 23 (1-78) months. Emergency surgery was performed in 17 patients (43.6%). The most common emergency indications were intestinal ischemia and/or perforation. Eight patients undergoing emergent surgery (44.4%) died within the first 30 days after primary abdominal operation, mainly due to sepsis and consecutive multiple organ failure, resulting in a dismal median survival of one month (0-52). Patients undergoing abdominal surgery had significantly lower rates of realized heart-transplantation (p = 0.031) and a significantly higher rate of VAD exchange, before or after abdominal surgery, due to thromboses or infections (p = 0.037). Nonetheless, overall survival after primary VAD implantation in these patients (median 38 months; 0-107) was not significantly impaired when compared to all other patients undergoing VAD implantation (median 30 months; 0-171). In summary, elective abdominal surgery can be performed safely when well planned by an experienced multidisciplinary team. Abdominal complications in VAD patients requiring emergent surgery, however, lead to a significant increase in short-term morbidity and a high 30-day mortality rate.

Clinical features and MRI progression of small duct primary sclerosing cholangitis (PSC).

PURPOSE: First, to evaluate and describe the clinical and MRI progression of patients with small duct primary sclerosing cholangitis (sdPSC), and second, to look for MRI features associated with disease progression to large duct PSC. METHOD: 16 patients (7 female, 9 male; median age 27 years) with diagnosis of sdPSC and available MR imaging were included in this retrospective dual-center study. Liver function tests (LFTs) and imaging was reviewed in consensus by two radiologists at baseline and follow-up, and compared by means of non-parametric tests, with p < 0.05 deemed significant. RESULTS: At baseline and follow-up patients had a cholestatic liver profile with elevated LFTs. Progressive liver deformity, heterogeneous enhancement and hilar lymphadenopathy were common findings. In 9 patients follow-up MRI was available with a mean interval between imaging of 10.6 years (range 3.6-15.3 years). 5 patients (55.5 %) developed cholangiographic changes diagnostic of large duct PSC. No correlation was observed between MRI findings or LFTs at baseline and the endpoint of developing PSC typical cholangiographic changes at follow-up imaging (p > 0.05). CONCLUSIONS: More than half of sdPSC patients developed cholangiographic changes, supporting that sdPSC may be an early stage of large duct PSC rather than an entity of its own. Larger studies are needed to address the value of MRI for prediction of sdPSC disease progression.

Ablation zone geometry after CT-guided hepatic microwave ablation: evaluation of a semi-automatic software and comparison of two different ablation systems.

Purpose: The aims of this study were to evaluate a semi-automatic segmentation software for assessment of ablation zone geometry in computed tomography (CT)-guided microwave ablation (MWA) of liver tumors and to compare two different MWA systems.Material and Methods: 27 patients with 40 hepatic tumors (primary liver tumor n = 20, metastases n = 20) referred for CT-guided MWA were included in this retrospective IRB-approved study. MWA was performed using two systems (system 1: 915 MHz; n = 20; system 2: 2.45 GHz; n = 20). Ablation zone segmentation and ellipticity index calculations were performed using SAFIR (Software Assistant for Interventional Radiology). To validate semi-automatic software calculations, results (2 perpendicular diameters, ellipticity index, volume) were compared with those of manual analysis (intraclass correlation, Pearson's correlation, Mann-Whitney U test; p < 0.05 deemed significant.Results: Manual measurements of mean maximum ablation zone diameters were 43 mm (system 1) and 34 mm (system 2), respectively. Correlations between manual and semi-automatic measurements were r = 0.72 and r = 0.66 (both p < 0.0001) for perpendicular diameters, and r = 0.98 (p < 0.001) for volume. Manual analysis demonstrated that ablation zones created with system 2 had a significantly lower ellipticity index compared to system 1 (mean 1.17 vs. 1.86, p < 0.0001). Results correlated significantly with semi-automatic software measurements (r = 0.71, p < 0.0001).Conclusion: Semi-automatic assessment of ablation zone geometry using SAFIR is feasible. Software-assisted evaluation of ablation zones may prove beneficial with complex ablation procedures, especially for less experienced operators. The 2.45 GHz MWA system generated a significantly more spherical ablation zone compared to the 915 MHz system. The choice of a specific MWA system significantly influences ablation zone geometry.

Impact of active dose management on radiation exposure and image quality in computed tomography: An observational study in 1315 patients.

PURPOSE: To determine the clinical impact of CT dose management team on radiation exposure and image quality. METHODS: 2026 clinical routine CT examinations of 1315 patients were evaluated retrospectively. A CT dose management team was established as an integral part of the radiological department. It identified 5 CT protocols (A-E), where national reference values were exceeded the most. Those reference values included specifically the mean volumetric CT dose index (CTDIvol) and the mean dose-length product (DLP). Baseline data (period 1) and follow up data (period 2) were obtained after reduction of tube voltage and increase of pitch or noise index. Signal-to-noise ratios (SNR) and contrast-to-noise ratios (CNR) were calculated to compare image quality. Two-sided t-tests were performed. RESULTS: Mean CTDIvol and mean DLP of the chest protocol (A) decreased after reduction of tube voltage (P < 0.01). In the chest/abdomen/pelvis protocol (B), the increase of noise index resulted in a significant mean CTDIvol decrease (P < 0.02) without statistical significance of mean DLP (P < 0.12). In the abdomen/pelvis protocol (C), mean CTDIvol (P = 0.01) and mean DLP (P < 0.01) were significantly lower after noise index increase. In the staging of hepatocellular carcinoma (D), mean CTDIvol and mean DLP were significantly lower after increase of pitch and noise index (P < 0.01). The lung protocol (E) yielded no significant changes after modulation (P > 0.05). SNR (protocol A) was significantly higher in period 2 (P < 0.04). Protocol D showed significantly lower selected SNR and CNR (P < 0.02). CONCLUSIONS: Establishing an operating dose management team as a standard for good clinical practice helps to considerably reduce CT radiation dose while preserving image quality.

Complications of CT-guided lung biopsy with a non-coaxial semi-automated 18 gauge biopsy system: Frequency, severity and risk factors.

OBJECTIVES: To evaluate frequency and severity of complications after CT-guided lung biopsy using the Society of Interventional Radiology (SIR) classification, and to assess risk factors for overall and major complications. MATERIALS AND METHODS: 311 consecutive biopsies with a non-coaxial semi-automated 18 gauge biopsy system were retrospectively evaluated. Complications after biopsy were classified into minor SIR1-2 and major SIR3-6. Studied risk factors for complications were patient-related (age, sex and underlying emphysema), lesion-related (size, location, morphologic characteristic, depth from the pleura and histopathology), and technique-related (patient position during procedure, thoracic wall thickness at needle path, procedure time length and number of procedural CT images, number of pleural passes, fissure penetration and needle-to-blood vessel angle). Data were analyzed using logistic and ordinal regression. RESULTS: Complications were pneumothorax and pulmonary hemorrhage. The complications were minor SIR1-2 in 142 patients (45.6%), and major SIR3-4 in 25 patients (8%). SIR5-6 complications were not present. Emphysema, smaller deeply located lesion, increased puncture time length and number of procedural CT images, multiple pleural passes and fissure puncture were significant risk factors for complication severity in univariate analysis. Emphysema (OR = 8.8, p<0.001), lesion depth from the pleura (OR = 1.9 per cm, p<0.001), and fissure puncture (OR = 9.4, p = 0.01) were the independent factors for major complications in a multiple logistic regression model. No statistical difference of complication rates between the radiologists performing biopsies was observed. CONCLUSIONS: Knowledge about risk factors influencing complication severity is important for planning and performing CT-guided lung biopsies.

An Imaging Biomarker for Assessing Hepatic Function in Patients With Primary Sclerosing Cholangitis.

BACKGROUND & AIMS: We aimed to evaluate the potential of hepatobiliary phase magnetic resonance imaging (MRI) as parameter for assessment of hepatocellular function in patients with primary sclerosing cholangitis (PSC). METHODS: We collected data from 111 patients (83 male, 28 female; median, 44 years old), from March 2012 through March 2016, with a confirmed diagnosis of PSC who underwent MRI evaluation before and after injection (hepatobiliary phase) of a hepatocyte-specific contrast agent (gadoxetate disodium). Signal intensities were measured in each liver segment. Mean relative enhancement values were calculated and correlated with findings from liver functions tests, prognostic scoring systems (model for end-stage liver disease [MELD] score; Mayo risk score; Amsterdam-Oxford-PSC score), abnormalities detected by endoscopic retrograde cholangiopancreatography (using the Amsterdam cholangiographic classification system), and clinical endpoints (liver transplantation, cholangiocarcinoma, liver-related death). Our primary aim was to associate relative enhancement values with liver function and patient outcomes. RESULTS: Most patients had moderate-stage disease and had intermediate levels of risk (median MELD score, 8 and median Mayo score, 0.27). Clinical endpoints were reached by 21 patients (6 developed cholangiocarcinoma, 8 underwent liver transplantation, and 7 patients died). The highest levels of correlations were observed for relative enhancement 20 min after contrast injection and level of alkaline phosphatase (r = -0.636), bilirubin (r = -0.646), albumin (r = 0.538); as well as international normalized ratio (r = 0.456); MELD score (r = -0.587); Mayo risk score (r = -0.535), and Amsterdam-Oxford model score (r = -0.595) (P < .0001). Relative enhancement correlated with all clinical endpoints (all P < .05). A cutoff relative enhancement value of 0.65 identified patients with a clinical endpoint with 73.9% sensitivity 92.9% specificity (area under the receiver operating characteristic curve, 0.901; likelihood ratio, 10.34; P < .0001). CONCLUSIONS: In an analysis of 111 patients with PSC, we found MRI-measured relative enhancement, using a hepatocyte-specific contrast agent, to identify patients with clinical outcomes with 73.9% sensitivity 92.9% specificity. Long-term, multicenter studies are needed to further evaluate this marker of PSC progression.

CT-Guided Microwave Ablation of Liver Tumors in Anatomically Challenging Locations.

PURPOSE: To assess the feasibility and outcome of microwave ablation (MWA) of hepatic tumors in anatomically challenging locations. MATERIALS AND METHODS: A total of 94 patients with 174 hepatic tumors referred for CT-guided MWA were included in this retrospective institutional review board-approved study. One hundred and twenty-five tumors (median size 17 mm, range 12-24 mm) with subcapsular location (n = 91) and/or in which a transpleural approach was applied (n = 53) were identified (group 1) and compared to tumors with a central intrahepatic location (group 2; n = 49, median size 19 mm, range 12-23 mm). Technical success, complications and local tumor progression (LTP) were evaluated. Risk factors were analyzed using univariate analysis, logistic regression and Kaplan-Meier curves (p < 0.05 deemed significant). RESULTS: Technical success was 100% in both groups. In group 1, complications occurred in n = 31 tumors (24.8%; pneumothorax n = 20; hematoma n = 11). Complications occurred significantly less often in group 2 (8.2%; n = 4 (hematoma); p = 0.011). There were no major complications. Transpleural approach and number of capsule punctures were identified as risk factors for complications (all p < 0.05). Median follow-up was 265 days. LTP was comparable between both groups (13.6 vs. 10.2%; p = 0.41). Use of hydrodissection was the only independent factor associated with LTP (p = 0.03, HR 3.29). CONCLUSION: CT-guided hepatic MWA of subcapsular tumors and subdiaphragmatic tumors requiring a direct or transpleural approach is feasible with increased minor but not major complications. LTP did not differ significantly between both groups.

The Role of Endoscopic Retrograde Cholangiopancreatography in the Diagnosis of Biliary Atresia: 14 Years' Experience.

INTRODUCTION: Biliary atresia (BA) is a rare destructive inflammatory obliterative cholangiopathy of neonates. Early diagnosis is important in disease management. The aim was to evaluate the role of endoscopic retrograde cholangiopancreatography (ERCP) in diagnosing BA in a large cohort. In addition, we evaluated whether parameters such as bile trace, GGT, bilirubin, and laboratory values in combination can be used to develop a risk score that could indicate the referral to specialized centers. MATERIALS AND METHODS: All infants with neonatal cholestasis (2000-2014) who presented to our endoscopy unit for suspected BA were included. Demographics, laboratory parameters, ultrasound findings, liver biopsy results, ERCP diagnosis, and surgical outcome were collected. Value and safety of ERCP and risk factors for BA were retrospectively analyzed. RESULTS: We included 251 infants in our cohort (55% males, median age: 53 days). BA was intraoperatively diagnosed in 155 (83.4%) patients and was excluded in 30 (16.2%). Fifty-six cases were not operated due to the ERCP findings. ERCP was successful in 224/251 patients (89.2%) with no procedure-related complications. The operative and endoscopic diagnosis matched in 96.6% of the patients (positive predictive value: 92.2%, negative predictive value: 97.1%). In comparison to cases with excluded BA, the ones with this disease were significantly associated with absence of duodenal bile traces (98.4 vs. 1.6%, p < 0.001), higher bilirubin (p < 0.001, cutoff 7.3 mg/dL), and higher GGT (p < 0.001, cutoff 250 U/L). CONCLUSION: ERCP is safe and accurate in the hands of experts in diagnosing BA if the cause of cholestasis is unclear. While evaluating the role of ERCP for diagnosing this disease, we found that the secondary parameters GGT > 250 U/L, bilirubin > 7.3 mg/dL (125 µmol/L), and the absence of bile traces are risk factors.

Associating Liver Partition and Portal vein ligation for Staged hepatectomy after pre-operative chemotherapy.

BACKGROUND: Recently a procedure termed 'Associating Liver Partition and Portal vein ligation for Staged hepatectomy' (ALPPS) was developed to increase the resectability of marginally resectable or locally unresectable liver tumours. This study focused on the application of ALPPS in patients with advanced colorectal liver metastases (CRLM) and pre-operative chemotherapy, with the aim to investigate whether the latter still allows for sufficient hypertrophy of the future liver remnant (FLR) following the first step of ALPPS. METHODS: Retrospective analysis was performed on six patients suffering from advanced CRLM. Analyses comprised demographical and basic clinical data, the perioperative courses as well as short- and long-term outcomes. RESULTS: All patients presented with bilobular CRLM and pre-operative chemotherapy of at least 6 months. Extended right hemihepatectomy was performed in all cases, four patients additionally received atypical resections in segments II/III. Mean FLR prior to step 1 of ALPPS was 397.9 cm3 (121-753 cm3 ), on average representing 20.9% of the total liver volume (13.2-27.1%). A mean hypertrophy of the FLR of 67.9% (32.5-94.1%) was achieved. Overall, severe morbidity (Dindo Clavien >3a) occurred in two patients. Following completion of ALPPS, mean post-operative disease-free survival was 5.7 months (2.6-8.9 months). CONCLUSION: Despite pre-operative chemotherapy, ALPPS seems to result in adequate liver hypertrophy, preventing post-operative small-for-size syndrome. However, there might be a high risk of tumour recurrence in patients with an aggressive tumour biology.

Monitoring of liver function in a 73-year old patient undergoing 'Associating Liver Partition and Portal vein ligation for Staged hepatectomy': case report applying the novel liver maximum function capacity test.

BACKGROUND: The two-stage liver resection combining in situ liver transection with portal vein ligation, also referred to as ALPPS (Associating Liver Partition and Portal vein ligation for Staged hepatectomy), has been described as a promising method to increase the resectability of liver tumors. However, one of the most important issues regarding the safety of this procedure is the optimal timing of the second stage at the point of sufficient hypertrophy of the future liver remnant. The recently developed liver maximum function capacity test (LiMAx) can be applied to monitor the liver function postoperatively and hence could be a useful tool for decision-making regarding the timing of the second stage of ALPPS. CASE PRESENTATION: A 73-year-old female patient presented with metachronous colorectal liver metastasis comprising the complete right liver lobe as well as segment IV. Due to an insufficient future liver remnant (19.3 %; segments II and III of the liver) and a low future liver remnant:body weight ratio (0.28 %) the decision was made to perform an ALPPS-procedure in order to avoid development of postoperative small-for-size syndrome. Despite a formally sufficient increase of the FLR to 30.8 % within 7 days after the first step of ALPPS, the liver function was seen to only slowly increase as expressed by a LiMAx value of 245 µg/h/kg (baseline of 282 µg/h/kg prior to surgery). By means of the LiMAx test, sufficient increase of liver function eventually was detected by postoperative day 11 (LiMAx value of 371 µg/h/kg; FLR 35.2 %) so that the second step of ALPPS (completion of hepatectomy) was performed with no signs of liver failure during further clinical course. CONCLUSION: Performing ALPPS we have observed a significant difference between the increase in future liver remnant volume and function applying the LiMAx test. The latter tool thus might proof valuable for application in two-stage liver resection to avoid postoperative small-for-size syndrome.

A case of pancreatic cancer with concomitant median arcuate ligament syndrome treated successfully using an allograft arterial transposition.

An association of pancreatic cancer and median arcuate ligament syndrome (MALS) is a rare and challenging situation in terms of treatment. A 60-year-old man diagnosed with pancreatic cancer underwent laparotomy. A pancreaticoduodenectomy was planned, but during the resection part of the operation, a celiac artery stenosis was noticed. The patient was diagnosed with MALS causing almost total celiac artery occlusion, with no radiological solution. The patient was re-operated the next day, and an iliac artery allograft was used for aorta-proper hepatic artery reconstruction, concomitant with the total pancreaticoduodenectomy. Preoperative meticulous evaluation of vascular structures of the celiac trunk and its branches is important, especially in pancreatic surgery. A vascular allograft may be a lifesaving alternative when vascular reconstruction is necessary.

Experimental Evaluation of the Heat Sink Effect in Hepatic Microwave Ablation.

PURPOSE: To demonstrate and quantify the heat sink effect in hepatic microwave ablation (MWA) in a standardized ex vivo model, and to analyze the influence of vessel distance and blood flow on lesion volume and shape. MATERIALS AND METHODS: 108 ex vivo MWA procedures were performed in freshly harvested pig livers. Antennas were inserted parallel to non-perfused and perfused (700,1400 ml/min) glass tubes (diameter 5mm) at different distances (10, 15, 20mm). Ablation zones (radius, area) were analyzed and compared (Kruskal-Wallis Test, Dunn's multiple comparison Test). Temperature changes adjacent to the tubes were measured throughout the ablation cycle. RESULTS: Maximum temperature decreased significantly with increasing flow and distance (p<0.05). Compared to non-perfused tubes, ablation zones were significantly deformed by perfused tubes within 15 mm distance to the antenna (p<0.05). At a flow rate of 700 ml/min ablation zone radius was reduced to 37.2% and 80.1% at 10 and 15 mm tube distance, respectively; ablation zone area was reduced to 50.5% and 89.7%, respectively. CONCLUSION: Significant changes of ablation zones were demonstrated in a pig liver model. Considerable heat sink effect was observed within a diameter of 15 mm around simulated vessels, dependent on flow rate. This has to be taken into account when ablating liver lesions close to vessels.