Operative microwave ablation for hepatocellular carcinoma: a single center retrospective review of 219 patients.

BACKGROUND: Microwave ablation (MWA) of hepatocellular carcinoma (HCC) offers local regional treatment that can be safely and effectively performed, even in patients with advanced liver disease. We update results from our group's previous analysis of operative MWA for HCC. METHODS: Retrospective review was performed of all patients who underwent operative MWA for HCC from 2007-2014. Patient demographics, operative characteristics and complications were recorded. Follow up imaging was reviewed to determine rates of complete ablation, local, regional and metastatic recurrence. RESULTS: Two hundred and nineteen patients were included with a total of 340 tumors treated with operative MWA. Median tumor size was 3.2 cm (range, 1-6 cm). Cirrhosis was present in 89.5% of patients, 60.7% had hepatitis C, and 8.2% had hepatitis B. Thirty-five point nine percent were Child-Pugh class B/C. Ninety-six point eight percent of MWA procedures were performed laparoscopically. Four deaths occurred within 30 days (1.8%). Clavien-Dindo grade III complications occurred in 3.2% of patients. Complete ablation was identified in 97.1% of tumors, with local recurrence rates of 8.5% at 10.9 months median follow up (0-80 months). Regional recurrence occurred in 34.8% of patients at 10.9 months median follow up and metastatic recurrence was seen in 8.1% of patients. One year overall survival was 80.0% and 2-year survival was 61.5%. CONCLUSIONS: We propose that laparoscopic MWA offers a low morbidity approach for treatment of HCC affording low rates of local recurrence even for patients with significant underlying liver dysfunction. This large series offers insight into outcomes of this modality as definitive treatment for patients with HCC.

Postmarketing Analysis of a Novel, Cordless Ultrasonic Dissector.

Introduction Tissue dissection and vessel sealing is performed using a variety of energy sources and surgical devices. We describe the postmarketing analysis of a cordless ultrasonic dissector and vessel sealer in a series of general and gynecological procedures. Methods Patients were prospectively screened and consented for participation. Data collected included demographics, device activations/seals and failures, and patient complications. Surgeons were surveyed following each case. Data was analyzed using standard statistical methods. Results A total of 110 patients were consented and participated in the study. The most frequently performed procedures were bilateral salpingo-oophorectomy (n = 48) and total laparoscopic hysterectomy (n = 36). Mean age was 54.2 years and 79.2% were female. The most frequent number of device activations per case was between 26 and 50 (36.6%). Five failed seals occurred out of 4858 total estimated seals (0.11%). Failed seals were felt to be due to thickened, scarred tissue not amenable to device compression. There were no patient intraoperative complications related to the device itself. Overall, surgeons felt the device was extremely easy to use (97.6%) and no visual obstruction due to steam from the device was encountered (95%). Ninety-five percent of surgeons felt the device was beneficial for soft tissue dissection and vessel sealing. Conclusion Sonicision is safe and effective for use in dissection of soft tissues and vessel sealing in a variety of laparoscopic and open procedures. In this study, there were no complications related to the device itself. The remarkable cordless design of this device enhances its ease of use with overall excellent effectiveness.

Multimodality treatment of intrahepatic cholangiocarcinoma: A review.

Intrahepatic cholangiocarcinoma (iCCA) is the second most common primary hepatic cancer in the United States. Currently, curative treatment involves aggressive surgery. Chemotherapy and radiation treatments have been used for unresectable tumors with some success. Optimizing the use of current and developing novel multimodality treatment for iCCA is essential to improving outcomes.

Mixed Hepatocellular Carcinoma, Neuroendocrine Carcinoma of the Liver.

We present the case of a 76-year-old male found to have a large tumor involving the left lateral lobe of the liver, presumed to be hepatocellular carcinoma (HCC). After resection, pathologic features demonstrated both high-grade HCC and high-grade neuroendocrine carcinoma (NEC). Areas of NEC stained strongly for synaptophysin, which was not present in HCC component. The HCC component stained strongly for Hep-Par 1, which was not present in the NEC component. The patient underwent genetic analysis for biomarkers common to both tumor cell types. Both tumor components contained gene mutations in CTNNB1 gene (S33F located in exon 3). They also shared mutations in PD-1, PGP, and SMO. Mixed HCC/NEC tumors have been rarely reported in the literature with generally poor outcomes. This patient has been referred for adjuvant platinum-based chemotherapy; genetic biomarker analysis may provide some insight to guide targeted chemotherapy.

Mortality in hepatectomy: Model for End-Stage Liver Disease as a predictor of death using the National Surgical Quality Improvement Program database.

BACKGROUND: The predictive value of the Model for End-stage Liver Disease (MELD) for mortality after hepatectomy is unclear. This study aimed to evaluate whether MELD score predicts death after hepatectomy and to identify the most useful score type for predicting mortality. We hypothesized that an increase in this score is correlated with 30-day mortality in patients undergoing hepatic resection. METHODS: The American College of Surgeons National Surgical Quality Improvement Program database was queried for hepatectomy. Original MELD, United Network of Organ Sharing-modified MELD (uMELD), integrated MELD (i-MELD), and sodium-corrected MELD (MELD-Na) scores were calculated. Mortality was analyzed by multivariate logistic regression. MELD types were compared using receiver operating characteristic (ROC) curves. RESULTS: From 2005 to 2011, 11,933 hepatic resections were performed, including 7,519 partial, 2,104 right, and 1,210 left resections, and 1,100 trisectionectomies. The mean duration of stay was 8.4 ± 22.0 days, and there were 275 deaths (2.4%). The 30-day mortality rates were 1.8%, 6.9%, 15.4%, and 25% according to uMELD strata of 0-9, 10-19, 20-29, and ≥ 30, respectively. Multivariate analysis revealed that increasing MELD stratum was independently associated with higher mortality (P < .001) for all MELD types. The uMELD had the largest effect size (odds ratio [OR], 1.16; 95% CI, 1.10-1.20), whereas i-MELD had the narrowest CI (OR, 1.13; 95% CI, 1.10-1.17) and largest area under the ROC curve. CONCLUSION: The postoperative 30-day mortality after hepatectomy increases with increasing MELD score across all MELD types. There is a 16% increase in the odds of mortality for each point increase in uMELD.

Building the Nonuniversity, Tertiary Care Center Hepatobiliary and Pancreatic Surgery Practice: Structural and Financial Considerations.

Early in their careers, many new surgeons lack the background and experience to understand essential components needed to build a surgical practice. Surgical resident education is often devoid of specific instruction on the business of medicine and practice management. In particular, hepatobiliary and pancreatic (HPB) surgeons require many key components to build a successful practice secondary to significant interdisciplinary coordination and a scope of complex surgery, which spans challenging benign and malignant disease processes. In the following, we describe the required clinical and financial components for developing a successful HPB surgery practice in the nonuniversity tertiary care center. We discuss significant financial considerations for understanding community need and hospital investment, contract establishment, billing, and coding. We summarize the structural elements and key personnel necessary for establishing an effectual HPB surgical team. This article provides useful, essential information for a new HPB surgeon looking to establish a surgical practice. It also provides insight for health-care administrators as to the value an HPB surgeon can bring to a hospital or health-care system.

Outcomes of surgical resection and loco-regional therapy in patients with stage 3A hepatocellular carcinoma: a retrospective review from the national cancer database.

OBJECTIVES: In advanced stages, hepatocellular carcinoma (HCC) is often associated with major vascular involvement (cava, portal vein). The aim of the present study was to analyse the role of surgical resection (SR) and loco-regional therapy (LRT) in these advanced stage patients to determine if there was a survival benefit. METHODS: The study is a retrospective analysis from the Commission on Cancer's National Cancer Data Base (NCDB) from 1998 to 2011. In total, 148,882 patients with liver cancer were identified, of which 126,984 had HCC. Of these, 64,264 patients (1998-2006) had 5-year survival data available and 8825 patients had Stage 3A disease based on AJCC classification. Of these patients, 884 had SR, 771 had LRT and 7170 patients had neither intervention. Kaplan-Meier curves and log-rank tests were used for statistical analysis. RESULTS: Eight thousand eight hundred and twenty-five patients met analysis criteria. The mean age (years) in the SR, LRT and no intervention group were 62.5, 64.3 and 64.2, respectively. Most patients were males in all three groups (77.5%, 74.5% and 68.1%). The mean tumour size (cm) in the three groups was 9.8, 6.4 and 8.4, respectively. SR and LRT were primarily performed in major academic and comprehensive cancer programmes compared with community cancer programmes and other centres (SR: 93% versus 7%; LRT: 94.6% versus 5.4%). The median 5-year survival (months) was 26.6 in SR, 16.5 in LRT and 4.8 in the no intervention group (P < 0.0001). CONCLUSION: A SR and LRT offer a survival benefit in select patients diagnosed with Stage 3A HCC.

Robotic pancreaticoduodenectomy for pancreatic adenocarcinoma: role in 2014 and beyond.

Minimally invasive surgery (MIS) for pancreatic adenocarcinoma has found new avenues for performing pancreaticoduodenectomy (PD) procedures, a historically technically challenging operation. Multiple studies have found laparoscopic PD to be safe, with equivalent oncologic outcomes as compared to open PD. In addition, several series have described potential benefits to minimally invasive PD including fewer postoperative complications, shorter hospital length of stay, and decreased postoperative pain. Yet, despite these promising initial results, laparoscopic PDs have not become widely adopted by the surgical community. In fact, the vast majority of pancreatic resections performed in the United States are still performed in an open fashion, and there are only a handful of surgeons who actually perform purely laparoscopic PDs. On the other hand, robotic assisted surgery offers many technical advantages over laparoscopic surgery including high-definition, 3-D optics, enhanced suturing ability, and more degrees of freedom of movement by means of fully-wristed instruments. Similar to laparoscopic PD, there are now several case series that have demonstrated the feasibility and safety of robotic PD with seemingly equivalent short-term oncologic outcomes as compared to open technique. In addition, having the surgeon seated for the procedure with padded arm-rests, there is an ergonomic advantage of robotics over both open and laparoscopic approaches, where one has to stand up for prolonged periods of time. Future technologic innovations will likely focus on enhanced robotic capabilities to improve ease of use in the operating room. Last but not least, robotic assisted surgery training will continue to be a part of surgical education curriculum ensuring the increased use of this technology by future generations of surgeons.

Laparoscopic microwave ablation of human liver tumours using a novel three-dimensional magnetic guidance system.

BACKGROUND: Accurate antenna placement is essential for effective microwave ablation (MWA) of lesions. Laparoscopic targeting is made particularly challenging in liver tumours by the needle's trajectory as it passes through the abdominal wall into the liver. Previous optical three-dimensional guidance systems employing infrared technology have been limited by interference with the line of sight during procedures. OBJECTIVE: The aim of this study was to evaluate a newly developed magnetic guidance system for laparoscopic MWA of liver tumours in a pilot study. METHODS: Thirteen patients undergoing laparoscopic MWA of liver tumours gave consent to their participation in the study and were enrolled. Lesion targeting was performed using the InnerOptic AIM™ 3-D guidance system to track the real-time position and orientation of the antenna and ultrasound probe. RESULTS: A total of 45 ablations were performed on 34 lesions. The median number of lesions per patient was two. The mean ± standard deviation lesion diameter was 18.0 ± 9.2 mm and the mean time to target acquisition was 3.5 min. The first-attempt success rate was 93%. There were no intraoperative or immediate postoperative complications. Over an average follow-up of 7.8 months, one patient was noted to have had an incomplete ablation, seven suffered regional recurrences, and five patients remained disease-free. CONCLUSIONS: The AIM™ guidance system is an effective adjunct for laparoscopic ablation. It facilitates a high degree of accuracy and a good first-attempt success rate, and avoids the line of site interference associated with infrared systems.

Optimal ablation volumes are achieved at submaximal power settings in a 2.45-GHz microwave ablation system.

INTRODUCTION: Local ablative therapies, including microwave ablation (MWA), are common treatment modalities for in situ tumor destruction. Currently, 2.45-GHz ablation systems are gaining prominence because of the shorter application times required. The aims of this study were to determine optimal power and time to ablation volume (AbV) ratios for a new 1.8-mm-2.45-GHz antenna using ex vivo tissue models. METHODS: The 1.8-mm-2.45-GHz Accu2i MWA system was employed to perform ablations in bovine liver, porcine muscle, and porcine kidney ex vivo. Whole tissues were prewarmed (35°C) and multiple ablations performed at power settings of 60 to 180 W for 2- to 6-minute time intervals. Postablation, tissues were dissected, AbVs calculated, and correlations to power and time settings made. RESULTS: Significant increases in AbV were measured between each of the time points for a constant power setting in all 3 tissues. Increasing power settings led to significant increases in AbV at power settings ≤140 W. However, no significant increase in AbV was obtained at power settings >140 W. CONCLUSIONS: Optimal efficiency for MWA using a new 1.8-mm-2.45-GHz system is achieved at settings of ≤140 W for 6 minutes in a range of ex vivo tissue and no additional benefit occurs by increasing the power setting to 180 W in these tissues.

Fibrin sealants and topical agents in hepatobiliary and pancreatic surgery: a critical appraisal.

INTRODUCTION: Fibrin sealants and topical hemostatic agents have been used extensively in hepatobiliary and pancreatic (HPB) surgery to promote coagulation and clot formation decreasing the need for allogeneic blood transfusion and to act as tissue sealants, ideally preventing biliary, enteric, and pancreatic leaks. RESULTS: Current literature has demonstrated some favorable outcomes using many different products for application in the field of HPB surgery. However, critical findings exist demonstrating lack of reproducible efficacy or benefit. In all, many clinical trials have demonstrated effectiveness of fibrin sealants and other agents at reducing the need for intraoperative and postoperative blood transfusion. Ability to effectively seal tissues providing biliostatic effect or preventing postoperative fistula formation remains debated as definitive evidence is lacking. CONCLUSIONS: In the following invited review, we discuss current literature describing the use of topical agents and fibrin sealants in liver and pancreas surgery. We summarize major contemporary clinical trials and their findings regarding the use of these agents in HPB surgery and provide evidence from the preclinical literature as to the translation of these products into the clinical arena.

Survival analysis of patients with stage I and II hepatocellular carcinoma after a liver transplantation or liver resection.

INTRODUCTION: Liver transplantation (LT) is a treatment option in select patients with hepatocellular carcinoma (HCC). The aim of the present study was to compare survival in Stage I or II HCC patients undergoing either liver transplant (LT) or a liver resection (LR). METHOD: The study is a retrospective analysis of the National Cancer Data Base (1998-2011). In total, 148,882 patients with liver cancer were identified, of which 5-year survival data (1998-2006) were available for 64,227 patients. Patients were stratified by the American Joint Committee on Cancer (AJCC) clinical stage I and II. Kaplan-Meier curves and log-rank tests were used for statistical analysis. RESULTS: 3340 HCC patients met analysis criteria. Among stage I HCC, 860 had LT and 871 had LR. Among stage II HCC, 833 had LT and 776 LR. In stage I patients the median survival for LT and LR were 127.9 and 56.7 months, respectively, (P < 0.0001) and in stage II patients the median survival was 110.8 and 42.8 months (P < 0.0001). Unlike LT patients, LR patients with Stage I HCC had a longer median survival compared with Stage II patients (P = 0.0002). CONCLUSION: Liver transplantation offers a survival advantage compared with a liver resection among patients with Stage I and II HCC. LT is the best surgical treatment for early stage (I/II) HCC in patients with advanced fibrosis or cirrhosis, whereas LR provides equivalent outcomes to LT in patients without advanced fibrosis and should be considered as the first surgical option.

Outcomes of pancreatic debridement in acute pancreatitis: analysis of the nationwide inpatient sample from 1998 to 2010.

BACKGROUND: The objective of this study was to perform a national review of patients with acute pancreatitis (AP) who undergo pancreatic debridement (PD) to evaluate for risk factors of in-hospital mortality. METHODS: The Nationwide Inpatient Sample was used to identify patients with AP who underwent PD between 1998 and 2010. Risk factors for in-hospital mortality were assessed with multivariate logistic regression. RESULTS: From 1998 to 2010, there were 585,978 nonelective admissions with AP, of which 1,783 (.3%) underwent PD. From 1998 to 2010, the incidence of PD decreased from .44% to .25% (P < .01) and PD in-hospital mortality decreased from 29.0% to 15% (P < .05). Of patients undergoing PD, independent factors associated with increased odds of mortality were increased age (odds ratio [OR] 1.04, confidence interval [CI] 1.03 to 1.05; P < .01), sepsis with organ failure (OR 1.76, CI 1.24 to 2.51; P < .01), peptic ulcer disease (OR 1.83, CI 1.02 to 3.30; P < .05), liver disease (OR 2.27, CI 1.36 to 3.78; P < .01), and renal insufficiency (OR 1.78, CI 1.14 to 2.78; P < .05). CONCLUSIONS: The incidence and operative mortality of PD have decreased significantly over the last decade in the United States with higher odds of dying in patients who are older, with chronic liver, renal, or ulcer disease, and higher rates of sepsis with organ failure.

The impact of regionalization of pancreaticoduodenectomy for pancreatic Cancer in North Carolina since 2004.

Pancreaticoduodenectomy (PD) carries a significant risk. High-volume centers (HVCs) provide improved outcomes and regionalization is advocated. Rapid regionalization could, however, have detrimental effects. North Carolina has multiple HVCs, including an additional HVC added in late 2006. We investigated regionalization of PD and its effects before, and after, the establishment of this fourth HVC. The North Carolina Hospital Discharge Database was queried for all PDs performed during 2004 to 2006 and 2007 to 2009. Hospitals were categorized by PD volume as: low (one to nine/year), medium (10 to 19/year), and high (20/year or more). Mortality and major morbidity was assessed by comparing volume groups across time periods. Number of PDs for cancer increased 91 per cent (129 to 246 cases) at HVCs, whereas decreasing at low-volume (62 to 58 cases) and medium-volume (80 to 46 cases) centers. Percentage of PD for cancer performed at HVCs increased significantly (47.6 to 70.3%) while decreasing for low- and medium-volume centers (P < 0.001). Mortality was significantly less at HVCs (2.8%) compared with low-volume centers (10.3%) for 2007 to 2009. Odds ratio for mortality was significantly lower at HVCs during 2004 to 2006 (0.31) and 2007 to 2009 (0.34). Mortality for PD performed for cancer decreased from 6.6 to 4.6 per cent (P = 0.31). Major morbidity was not significantly different between groups within either time period; however, there was a significant increase in major morbidity at low-volume centers (P = 0.018). Regionalization of PD for cancer is occurring in North Carolina. Mortality was significantly lower at HVCs, and rapid regionalization has not detracted from the superior outcomes at HVCs.

Laparoscopic transgastric endolumenal cystogastrostomy and pancreatic debridement.

BACKGROUND: Cystogastrostomy is commonly performed for internal drainage of pancreatic pseudocysts (PP) and concomitant debridement of walled-off pancreatic necrosis (WOPN). While an open approach to cystogastrostomy is well established, an optimal minimally invasive technique continues to evolve. This laparoscopic transgastric endolumenal cystogastrostomy presented here allows for a large cystogastrostomy with complete debridement of necrosis and internal drainage through a minimally invasive approach. METHODS: We performed a retrospective review of 22 patients with symptomatic PP/WOPN treated with attempted laparoscopic transgastric endolumenal cystogastrostomy (Lap-TEC) and pancreatic debridement. Short- and long-term outcomes were assessed. RESULTS: From November 2006 to March 2013, a total of 22 Lap-TEC/pancreatic debridement procedures were attempted; 15 were completed laparoscopically. The median age of the cohort was 49.5 ± 12 years (range = 18-71), average body mass index = 29.1 kg/m(2), 77 % had an ASA score ≥ 3, and 10 were female. Gallstones were the most common etiology (50 %), and median time between initial presentation and surgery was 86 days (range = 0-360). Median operative time and estimated blood loss were 213 min and 100 cc, respectively. Forty-one percent of the patients were admitted to the ICU postoperatively and the average length of stay was 14 days (range = 4-50). Median follow-up was 2 months (range = 0-62.5), with one patient having a procedure-related complication. No other reoperations, late complications, or mortalities occurred. All patients had resolution of their symptoms and fluid collections. CONCLUSION: This technique of internal drainage via Lap-TEC and pancreatic debridement has been successful in achieving primary drainage and relieving symptoms of PP/WOPN with no mortality and minimal morbidity.

Regionalization and outcomes of hepato-pancreato-biliary cancer surgery in USA.

BACKGROUND: Recent publications demonstrate regionalization of complex operations to high-volume centers (HVCs) in the USA. We hypothesize that this pattern applies to hepato-pancreato-biliary (HPB) cancer resections and improved outcomes. METHODS: The Nationwide Inpatient Sample (NIS) data were analyzed from 1995-1999(T1) to 2005-2009(T2) for all HPB oncologic resections. Division of hospitals into high-, mid-, and low-volume centers (HVC, MVC, LVC) was performed. Multivariate regression was utilized to identify predictors of LVC resection. Outcomes were compared in both eras. RESULTS: A total of 45,815 cases met the inclusion criteria (19,250 from T1 and 25,565 from T2). At T1, 32.5% of resections were performed at HVCs and 34.9% at LVCs. At T2, 60.8% were performed at HVCs versus 18.5% at LVCs. In T1, inpatient mortality at HVCs versus LVCs was 3.3% versus 8.67% (p < 0.0001) and 2.7% versus 6.5% (p < 0.0001) in T2. LOS and routine discharge were improved in HVCs, but total charges were higher. All outcomes significantly differed between HVCs and LVCs in multivariate analysis, except for LOS and total charges in T2. CONCLUSION: The most recent NIS data demonstrate better outcomes in HVCs for HPB oncologic resections. These trends reflect alignment with national recommendations to centralize complex cancer surgery, as well as improved outcomes in all centers.

Microwave ablation for hepatic malignancies: a multiinstitutional analysis.

OBJECTIVE: This study hypothesized that tumor size, number of tumors, surgical approach, and tumor histology significantly affected microwave ablation (MWA) success and recurrence-free survival. BACKGROUND: Although many hepatobiliary centers have adopted MWA, the factors that influence local control are not well described. METHODS: Consecutive patients with hepatic malignancy treated by MWA were included from 4 high-volume institutions (2003-2011) and grouped by histology: hepatocellular carcinoma (HCC), colorectal liver metastases, neuroendocrine liver metastases, and other cancers. Independent significance of outcome variables was established with logistic regression and Cox proportional hazards models. RESULTS: Four hundred fifty patients were treated with 473 procedures (139 HCC, 198 colorectal liver metastases, 61 neuroendocrine liver metastases, and 75 other) for a total of 875 tumors. Median follow-up was 18 months. Concurrent hepatectomy was performed in 178 patients (38%), and when performed was associated with greater morbidity. Complete ablation was confirmed for 839 of 865 tumors (97.0%) on follow-up cross-sectional imaging (10 were unevaluable). A surgical approach (open, laparoscopic, or percutaneous) had no significant impact on complication rates, recurrence, or survival. The local recurrence rate was 6.0% overall and was highest for HCC (10.1%, P = 0.045) and percutaneously treated lesions (14.1%, P = 0.014). In adjusted models, tumor size 3 cm or more predicted poorer recurrence-free survival (hazard ratio: 1.60, 95% CI: 1.02-2.50, P = 0.039). CONCLUSIONS: In this large data set, patients with 3 cm or more tumors showed a propensity for early recurrence, regardless of histology. Higher rates of local recurrence were noted in HCC patients, which may reflect underlying liver disease. There were no significant differences in morbidity or survival based on the surgical approach; however, local recurrence rates were highest for percutaneously ablated tumors.

Microwave ablation using 915-MHz and 2.45-GHz systems: what are the differences?

OBJECTIVES: This study was conducted to evaluate differences between 915-MHz and 2.45-GHz microwave ablation (MWA) systems in the ablation of hepatic tumours. METHODS: A retrospective analysis of patients undergoing hepatic tumour MWA utilizing two different systems over a 10-month period was carried out. RESULTS: Data for a total of 48 patients with a mean age of 58 ± 1.24 years were analysed. A total of 124 tumours were ablated; 72 tumours were ablated with a 915-MHz system and 52 with a 2.45-GHz system. Mean tumour diameters were 1.7 ± 0.1 cm in the 915-MHz group and 2.5 ± 0.2 cm in the 2.45-GHz group (P < 0.01). Mean ablation time per burn was 8.1 ± 0.3 min in the 915-MHz group and 4.0 ± 0.1 min in the 2.45-GHz group (P < 0.01). The mean number of burns per lesion was 2.0 ± 0.1 in the 915-MHz group and 1.7 ± 0.1 in the 2.45-GHz group (P < 0.05). The mean ablation time per lesion was 9.7 ± 0.7 min in the 915-MHz group, and 6.6 ± 0.6 min in the 2.45-GHz group (P < 0.01). The 2.45-GHz system demonstrated a better correlation between ablation time and tumour size (r(2) = 0.6222) than the 915-MHz system; (r(2) = 0.0696). Mean total energy applied per lesion, and energy applied per cm, were greater with the 915-MHz system (P < 0.05 and P < 0.01, respectively). Total energy applied per lesion was similarly correlated for the 2.45-GHz (r(2) = 0.6263) and 915-MHz (r(2) = 0.7012) systems. Mean total energy applied per cm/min was greater with the 2.45-GHz system (P < 0.05). CONCLUSIONS: Both 915-MHz and 2.45-GHz MWA systems achieve reproducible hepatic tumour ablation. The 2.45-GHz system achieves equivalent, but more predictable and faster ablations using a single antenna system.

Obesity, but not ethanol, promotes tumor incidence and progression in a mouse model of hepatocellular carcinoma in vivo.

BACKGROUND: Hepatocellular carcinoma (HCC) is a major global health burden. Although chronic, heavy alcohol abuse is an established risk factor for HCC, obesity is emerging as an increasingly important factor in HCC development. Given that other risk factors for HCC act synergistically to promote tumorigenesis, we investigated the effects of diet-induced obesity and chronic ethanol consumption on tumor progression. METHODS: A diethylnitrosamine (DEN) mouse model of HCC was established and mice randomized to control (CD; 10 % kcal% fat) or high fat (HFD; 60 % kcal% fat diet) at 5 weeks of age. At 35 weeks, mice were randomized to 10/20 % ethanol (EtOH) in drinking water (alternate days), or drinking water (H2O) alone. Tumor incidence/size were measured and confirmed. Liver tissue was analyzed for oxidative stress and EtOH-metabolizing enzymes and serum analyzed for liver function and nutritional status. RESULTS: DEN treatment induced HCC formation in 60 % CD-H2O mice (6 of 10), an effect exacerbated by HFD (89 %). Tumors in HFD animals occupied significantly more of the liver than mice on CD. EtOH-feeding did not impact HCC incidence or tumor size. HFD resulted in increased liver injury and liver:body weight ratio regardless of EtOH consumption. Increased tumor incidence was associated with elevated hepatic oxidative stress in the absence of changes in intrinsic antioxidant (glutathione) levels. CONCLUSIONS: Obesity independently promoted HCC formation in the absence or presence of a known hepatocarcinogen (DEN), and enhanced both number and size of hepatic tumors independent of chronic EtOH consumption in mice.

Operative microwave ablation for hepatocellular carcinoma: complications, recurrence, and long-term outcomes.

BACKGROUND: Treatment of hepatocellular carcinoma (HCC) in the setting of cirrhosis is limited by tumor size/location and underlying liver disease. Radiofrequency ablation is utilized in selected patients; however, local recurrence remains a concern. Microwave ablation (MWA) delivers energy to tissue in a unique fashion, reducing local recurrence. A minimally invasive operative approach allows for mobilization/protection of adjacent structures, intra-operative ultrasound, and assessment of ablation progress. STUDY DESIGN: Retrospective review of operative MWA performed for HCC in patients with cirrhosis over a 4-year period at a single center. Complications were stratified by Clavien-Dindo classification. Incomplete ablation and local, regional, and metastatic recurrence was assessed on follow-up imaging. Survival was assessed in months. RESULTS: Fifty-four patients with 73 tumors underwent MWA. Median tumor size was 2.6 cm (range 0.5-8.5 cm). Cirrhosis was present in 92.6 % of patients, with a Child-Pugh score of B/C in 27.8 % and hepatitis C present in 59.3 %. A minimally invasive approach was used in 94.5 % of patients. There were no deaths within 30 days. Thirty-day morbidity was 28.9 %, with grade III complications present in 11.5 %. Delayed complications occurred in 7.8 % of patients, with a 5.6 % 90-day mortality. Incomplete ablation was identified in 5.9 % of tumors with local recurrence of 2.9 % at 9 months median follow-up. Regional and metastatic recurrence occurred in 27.5 and 11.8 % at 9 months median follow-up. Median survival was not reached at 11 months median follow-up. One- and 2-year survival was 72.3 and 58.8 %. CONCLUSION: Operative, preferably minimally invasive, MWA can be performed in cirrhotic patients with HCC with acceptable morbidity and low recurrence rates. High regional and metastatic recurrence rates in these patients underscore the need for minimally invasive, low morbidity approaches to liver-directed therapy.