Comparison of survival outcomes after anatomical resection and non-anatomical resection in patients with hepatocellular carcinoma

BACKGROUNDS/AIMS: Liver resection is a curative procedure performed worldwide for hepatocellular carcinoma (HCC). Deciding on the appropriate resection range for postoperative hepatic function preservation is an important surgical consideration. This study compares survival outcomes of HCC patients who underwent anatomical or non-anatomical resection, to determine which offers the best clinical survival benefit. METHODS: One hundred and thirty-one patients underwent liver resection with HCC, between January 2007 and February 2015, and were divided into two groups: those who underwent anatomical liver resection (n=88) and those who underwent non-anatomical liver resection (n=43). Kaplan-Meier survival analysis and Cox regressions were used to compare the disease-free survival (DFS) and overall survival (OS) rates between the groups. RESULTS: The mean follow-up periods were 27 and 40 months in the anatomical and non-anatomical groups, respectively (p=0.229). The 3- and 5-year DFS rates were 70% and 60% in the anatomical group and 62% and 48% in the non-anatomical group, respectively. The 3 and 5-year OS rates were 94% and 78% in the anatomical group, and 86% and 80% in the non-anatomical group, respectively. The anatomical group tended to show better outcomes, but the findings were not significant. However, a relative risk of OS between the anatomical and non-anatomical group was 0.234 (95% CI, 0.061-0.896; p=0.034), which is statistically significant. CONCLUSIONS: Although statistical significance was not detected in survival curves, anatomical resection showed better results. In this respect, anatomical resection is more likely to perform in HCC patients with preserve liver function than non-anatomical resection.

Comparative analysis of intraoperative radiofrequency ablation versus non-anatomical hepatic resection for small hepatocellular carcinoma: short-term result

BACKGROUNDS/AIMS: To compare the clinical outcomes of intraoperative radiofrequency ablation (RFA) and non-anatomical hepatic resection (NAHR) for small hepatocellular carcinoma (HCC). METHODS: From February 2007 to January 2015, clinical outcomes of thirty four patients with HCC receiving RFA or NAHR were compared, retrospectively. RESULTS: There was no difference of patient and tumor characteristic between the two groups that received RFA or NAHR. The 1, 2, and 3-year recurrence rates following RFA were 32.2%, 32.2% and 59.3% respectively, and 6.7%, 33.3% and 33.3% following NAHR respectively (p=0.287). The 1, 2 and 3-year overall survival (OS) rates following RFA were 100%, 88.9% and 76.2% respectively, and 100%, 85.6% and 85.6%, respectively, following NAHR (p=0.869). We did not find a definite statistical difference in recurrence rate and OS rate between the two groups. In the multivariate analysis, number of tumor was an independent prognostic factor for recurrence and albumin was an independent prognostic factor for OS. CONCLUSIONS: We recommend non-anatomical hepatic resection rather than intraoperative RFA in small sized HCC, due to a higher recurrence rate in intraoperative RFA. Intraoperative RFA was inferior to non-anatomical hepatic resection in terms of recurrence rate. We need to select the optimal treatment considering liver function and possibility of recurrence.

Computation of geographic variables for air pollution prediction models in South Korea

Recent cohort studies have relied on exposure prediction models to estimate individual-level air pollution concentrations because individual air pollution measurements are not available for cohort locations. For such prediction models, geographic variables related to pollution sources are important inputs. We demonstrated the computation process of geographic variables mostly recorded in 2010 at regulatory air pollution monitoring sites in South Korea. On the basis of previous studies, we finalized a list of 313 geographic variables related to air pollution sources in eight categories including traffic, demographic characteristics, land use, transportation facilities, physical geography, emissions, vegetation, and altitude. We then obtained data from different sources such as the Statistics Geographic Information Service and Korean Transport Database. After integrating all available data to a single database by matching coordinate systems and converting non-spatial data to spatial data, we computed geographic variables at 294 regulatory monitoring sites in South Korea. The data integration and variable computation were performed by using ArcGIS version 10.2 (ESRI Inc., Redlands, CA, USA). For traffic, we computed the distances to the nearest roads and the sums of road lengths within different sizes of circular buffers. In addition, we calculated the numbers of residents, households, housing buildings, companies, and employees within the buffers. The percentages of areas for different types of land use compared to total areas were calculated within the buffers. For transportation facilities and physical geography, we computed the distances to the closest public transportation depots and the boundary lines. The vegetation index and altitude were estimated at a given location by using satellite data. The summary statistics of geographic variables in Seoul across monitoring sites showed different patterns between urban background and urban roadside sites. This study provided practical knowledge on the computation process of geographic variables in South Korea, which will improve air pollution prediction models and contribute to subsequent health analyses.

Computation of geographic variables for air pollution prediction models in South Korea

Recent cohort studies have relied on exposure prediction models to estimate individual-level air pollution concentrations because individual air pollution measurements are not available for cohort locations. For such prediction models, geographic variables related to pollution sources are important inputs. We demonstrated the computation process of geographic variables mostly recorded in 2010 at regulatory air pollution monitoring sites in South Korea. On the basis of previous studies, we finalized a list of 313 geographic variables related to air pollution sources in eight categories including traffic, demographic characteristics, land use, transportation facilities, physical geography, emissions, vegetation, and altitude. We then obtained data from different sources such as the Statistics Geographic Information Service and Korean Transport Database. After integrating all available data to a single database by matching coordinate systems and converting non-spatial data to spatial data, we computed geographic variables at 294 regulatory monitoring sites in South Korea. The data integration and variable computation were performed by using ArcGIS version 10.2 (ESRI Inc., Redlands, CA, USA). For traffic, we computed the distances to the nearest roads and the sums of road lengths within different sizes of circular buffers. In addition, we calculated the numbers of residents, households, housing buildings, companies, and employees within the buffers. The percentages of areas for different types of land use compared to total areas were calculated within the buffers. For transportation facilities and physical geography, we computed the distances to the closest public transportation depots and the boundary lines. The vegetation index and altitude were estimated at a given location by using satellite data. The summary statistics of geographic variables in Seoul across monitoring sites showed different patterns between urban background and urban roadside sites. This study provided practical knowledge on the computation process of geographic variables in South Korea, which will improve air pollution prediction models and contribute to subsequent health analyses.

Experience of laparoscopic liver resection for various liver diseases

BACKGROUNDS/AIMS: We present our experience of laparoscopic liver resection for various liver diseases. METHODS: From April 2008 to August 2012 in Chungnam National University, 68 of 253 liver resections were performed laparoscopically. During the first year, laparoscopy-assisted liver resection was mainly performed and subsequently totally laparoscopic liver resection was the main operative type. Surgery type for treatment purposes was decided preoperatively. Clinical data were collected retrospectively and analyzed. RESULTS: Preoperatively, 43 patients (63.2%) were diagnosed with benign disease, 19 patients (27.9%) were malignant liver tumors and 6 patients (8.8%) were indeterminate liver tumor but favorable towards malignancy. Anatomical major liver resection was performed in 58 cases (85.3%) and 10 cases (14.7%) were non-anatomical resection. Left hemihepatectomy was performed in 38 cases (55.8%) followed by left lateral sectionectomy in 18 cases (26.5%), and segment IV and IVa segmentectomy, were each in 1 case. Mean operation time was 235.0 minutes (range, 60-470) and 14 patients (18.6%) had intraoperative transfusion. Mean postoperative hospital stay was 10.2 days (range, 4-32). Mean operation time of laparoscopy-assisted left lobectomy was 317 minutes and totally laparoscopic left lobectomy was 281 minutes, but there was no significant statistical difference between these two operation types. There were 11 episodes of postoperative complications in 8 patients. There was no mortality after laparoscopic liver resection. CONCLUSIONS: We concluded that laparoscopic liver resection is a feasible operation, but needs to be carefully conducted in malignant tumors.

Comparative analysis of Laparoscopic versus open surgical radiofrequency ablation for malignant liver tumors

BACKGROUNDS/AIMS: This study aims to evaluate the comparative effectiveness of two surgical approaches on the treatment outcomes of radiofrequency ablation (RFA) for malignant liver tumors. METHODS: Fifty-seven patients with malignant liver tumors, hepatocellular carcinoma, cholangiocarcinoma and liver metastases, who were candidates for RFA, underwent laparoscopic or open surgical treatments. RESULTS: The patients' characteristics were comparable in the two groups that received open (n=33, 57.9%) and laparoscopic (n=24, 42.1%) surgical treatments. There were no statistically significant differences between the two groups in terms of recurrence rate (p=0.337) and overall survival (p=0.423). However, patients in the laparoscopic RFA group had significantly shorter hospital stay (14.1 vs. 5.9 days, p<0.05) and experienced fewer complications (Grade I: 62.5% vs. 26.3%, p=0.102). CONCLUSIONS: Laparoscopic RFA can be performed for malignant liver tumors with lower morbidity rates, less invasiveness and lower expense compared to open surgical approach.

Laparoscopic left hepatectomy in patients with intrahepatic duct stones and recurrent pyogenic cholangitis

BACKGROUNDS/AIMS: Recently many studies have been reported the early results of a hepatectomy for various intrahepatic lesions. Also various types of laparoscopic hepatectomies are being performed in many centers. Some reports about the safety of laparoscopic parenchymal dissection of the liver have been published. In this study, we reported our experiences of laparoscopic left hepatectomies in patients with an intrahepatic duct (IHD) stone with recurrent pyogenic cholangitis (RPC), and investigated whether the total laparoscopic parenchymal dissection is as safe as open surgery. METHODS: From April 2008 to December 2010, 25 patients had been admitted for left IHD stones with RPC. Preoperatively, the type of surgery was decided with the intention of treating each patient. Initially 10 patients underwent a laparoscopy-assisted left hepatectomy and the next 15 patients underwent total laparoscopic left hepatectomy as our experience grew. Demographics, peri- and postoperative results were collected and analyzed comparatively. RESULTS: The mean age, gender ratio, preoperative American Society of Anesthesiologists (ASA) score, accompanied acute cholangitis and biliary pancreatitis, and the number of preoperative percutaneous transhepatic biliary drainage (PTBD) inserted cases were not different between the two groups who had undergone laparoscopy-assisted and totally laparoscopic left hepatectomy. The operation time, intraoperative transfusions and postoperative complications also showed no difference between them. The postoperative hospital stay did not show a significant difference statistically. CONCLUSIONS: In this study, we concluded that a laparoscopic left hepatectomy can be adapted to the patients with a left IHD stone with RPC. Also laparoscopic parenchymal dissection is safe and equivalent to an open procedure.