Peter D. Peng

Sarcopenia negatively impacts short-term outcomes in patients undergoing hepatic resection for colorectal liver metastasis

BACKGROUND As indications for liver resection expand, objective measures to assess the risk of peri-operative morbidity are needed. The impact of sarcopenia on patients undergoing liver resection for colorectal liver metastasis (CRLM) was investigated. METHODS Sarcopenia was assessed in 259 patients undergoing liver resection for CRLM by measuring total psoas area (TPA) on computed tomography (CT). The impact of sarcopenia was assessed after controlling for clinicopathological factors using multivariate modelling. RESULTS Median patient age was 58 years and most patients (60%) were male. Forty-one (16%) patients had sarcopenia (TPA ≤ 500 mm(2) /m(2) ). Post-operatively, 60 patients had a complication for an overall morbidity of 23%; 26 patients (10%) had a major complication (Clavien grade ≥3). The presence of sarcopenia was strongly associated with an increased risk of major post-operative complications [odds ratio (OR) 3.33; P= 0.008]. Patients with sarcopenia had longer hospital stays (6.6 vs. 5.4 days; P= 0.03) and a higher chance of an extended intensive care unit (ICU) stay (>2 days; P= 0.004). On multivariate analysis, sarcopenia remained independently associated with an increased risk of post-operative complications (OR 3.12; P= 0.02). Sarcopenia was not significantly associated with recurrence-free [hazard ratio (HR) = 1.07] or overall (HR = 1.05) survival (both P > 0.05). CONCLUSIONS Sarcopenia impacts short-, but not long-term outcomes after resection of CRLM. While patients with sarcopenia are at an increased risk of post-operative morbidity and longer hospital stay, long-term survival is not impacted by the presence of sarcopenia.

Infiltrating Hepatocellular Carcinoma: Seeing the Tree through the Forest

IntroductionHepatocellular carcinoma (HCC) is a leading cause of cancer-related death worldwide. It is traditionally difficult to cure, especially when discovered at later stages, making early diagnosis and intervention of paramount importance. HCC typically arises in the background of chronic liver disease and can have various morphologic appearances. One of the most difficult of these to recognize on early surveillance imaging is the infiltrative subtype, which can account for up to 13% of all HCC cases, and may be more closely associated with background hepatitis B infection.DiscussionCertain imaging characteristics can provide vital clues, including differing signal intensity on the T1 and T2 sequences of magnetic resonance imaging (MRI) and the presence/appearance of portal vein thrombus. Owing to the diffuse and infiltrating properties of this tumor, surgical resection and transplantation are rarely if ever viable therapeutic options. Other forms of liver-directed therapy have been attempted with limited success, having minimal efficacy and high morbidity. To date, there is no data available to determine if the various HCC subtypes respond to systemic therapy differently, so this may be the most reasonable approach. Left untreated, observed patients commonly progress to hepatic failure fairly rapidly.ConclusionInfiltrative HCC can be extremely subtle, and therefore difficult to detect, especially in the background of cirrhosis. Providers caring for patients with hepatitis, chronic liver disease, and cirrhosis must be extremely vigilant in the evaluation of surveillance imaging in order to potentially discover this HCC subtype as early as possible and initiate a multidisciplinary treatment plan.

Hepatic Resection for Metastatic Gastrointestinal Stromal Tumors in the Tyrosine Kinase Inhibitor Era

Before the advent of tyrosine kinase inhibitors (TKIs), surgical resection was the primary treatment for hepatic gastrointestinal stromal tumor (GIST) metastases. Although TKIs have improved survival in the metastatic setting, outcomes after multimodal therapy comprised of hepatectomy and TKIs for GIST are unknown. The objective of this study was to determine whether combination therapy for hepatic GIST metastases is associated with improved overall survival compared with reported outcomes from surgery or TKI therapy alone.

Sequential intra-arterial therapy and portal vein embolization is feasible and safe in patients with advanced hepatic malignancies

BACKGROUND A major hepatic resection for malignancies requires an adequate post-operative liver reserve. Portal vein embolization (PVE) with intra-arterial therapy (IAT) may increase future liver remnant (FLR) hypertrophy. As such, the feasibility, safety and efficacy of IAT+PVE were investigated. METHODS Between 2000 to 2011, 86 patients with malignancy of the liver were identified from a multi-institutional database. Twenty-nine patients underwent sequential IAT+PVE, 25 had PVE alone and 32 had IAT alone. Clinicopathological data were evaluated. RESULTS Most patients had hepatocellular carcinoma (HCC) (65.1%) and 31.4% had secondary metastatic disease. A complete or partial response using European Association for the Study of the Liver (EASLD) criteria was seen in 48.3% of patients undergoing IAT+PVE vs. 56.6% among patients undergoing IAT (P = 0.601). The median increase in percentage FLR volume was comparable in IAT+PVE (7.4%) vs. PVE only (7.9%) (P = 0.203). There were no IAT+PVE-associated deaths and only one complication. Among patients treated with IAT+PVE (n = 29), 27 underwent a subsequent hepatic resection. Peri-operative morbidity and mortality was 29.6% and 7.4%, respectively. Among the patients with HCC who underwent curative intent surgery after IAT+PVE, the median survival was 59.0 months. CONCLUSIONS Sequential IAT and PVE are feasible and safe. Utilization of IAT+PVE before a resection can lead to long-term survival and should be considered in the treatment of patients with advanced hepatic malignancies.

Towards validation of robotic surgery training assessment across training platforms

Robotic surgery is increasingly popular for a wide range of complex minimally invasive surgery procedures. To improve robotic surgery training, a skills trainer simulator called dV-Trainer has recently been introduced, and a da Vinci Skills Simulator is in advanced evaluation. These platforms report a range of time and motion based task metrics and literature has investigated the validity of these metrics in training studies. However, the lack of a cross-platform data collection system has so far prevented a cross-platform investigation. Using a new architecture for collecting cross-platform motion data, we present the first study investigating whether metrics previously validated in simulation environments also hold in training exercises with a real robotic system. Preliminary experiments for an anastomosis needle throwing task in both simulated and real robotic environments are presented, and corresponding performance metrics for both proficient and trainee users are reported.

Percutaneous Palliation of Cholangiocarcinoma

Cholangiocarcinomas are malignant tumors arising from the biliary tract and have an worldwide incidence of 0.5∼2.0/100,000 [1]. Complete resection of early stage tumors can be curative [2]. In cases when the disease is unresectable, the prognosis is generally poor with a 1 year survival of 53 % and 5 year survival of less than 5 % [3–6].