Heat-zone effect after surface application of dissecting sealer on the "in situ margin" after tumorectomy for liver tumors

Application of the woodchuck animal model for the treatment of hepatitis B virus-induced liver cancer

This review describes woodchucks chronically infected with the woodchuck hepatitis virus (WHV) as an animal model for hepatocarcinogenesis and treatment of primary liver cancer or hepatocellular carcinoma (HCC) induced by the hepatitis B virus (HBV). Since laboratory animal models susceptible to HBV infection are limited, woodchucks experimentally infected with WHV, a hepatitis virus closely related to HBV, are increasingly used to enhance our understanding of virus-host interactions, immune response, and liver disease progression. A correlation of severe liver pathogenesis with high-level viral replication and deficient antiviral immunity has been established, which are present during chronic infection after WHV inoculation of neonatal woodchucks for modeling vertical HBV transmission in humans. HCC in chronic carrier woodchucks develops 17 to 36 mo after neonatal WHV infection and involves liver tumors that are comparable in size, morphology, and molecular gene signature to those of HBV-infected patients. Accordingly, woodchucks with WHV-induced liver tumors have been used for the improvement of imaging and ablation techniques of human HCC. In addition, drug efficacy studies in woodchucks with chronic WHV infection have revealed that prolonged treatment with nucleos(t)ide analogs, alone or in combination with other compounds, minimizes the risk of liver disease progression to HCC. More recently, woodchucks have been utilized in the delineation of mechanisms involved in innate and adaptive immune responses against WHV during acute, self-limited and chronic infections. Therapeutic interventions based on modulating the deficient host antiviral immunity have been explored in woodchucks for inducing functional cure in HBV-infected patients and for reducing or even delaying associated liver disease sequelae, including the onset of HCC. Therefore, woodchucks with chronic WHV infection constitute a well-characterized, fully immunocompetent animal model for HBV-induced liver cancer and for preclinical evaluation of the safety and efficacy of new modalities, which are based on chemo, gene, and immune therapy, for the prevention and treatment of HCC in patients for which current treatment options are dismal.

The impact of additional margin coagulation with radiofrequency in liver resections with subcentimetric margin: can we improve the oncological results? A propensity score matching study

BACKGROUND

Whereas the usefulness of radiofrequency (RF) energy as haemostatic method in liver surgery has become well established in the last decades, its intentional application on resection margins with the aim of reducing local recurrence is still debatable. Our goal was to compare the impact of an additional application of RF energy on the top of the resection surface, namely additional margin coagulation (AMC), on local recurrence (LR) when subjected to a subcentimeter margin.

METHODS

We retrospectively analyzed 185 patients out of a whole cohort of 283 patients who underwent radical hepatic resection with subcentimetric margin. After propensity score adjustment, patients were classified into two balanced groups according to whether RF was applied or not.

RESULTS

No significant differences were observed within groups in baseline characteristics after PSM adjustment. The LR rate was significantly higher in the Control than AMC Group: 12 patients (14.5%) vs. 4 patients (4.8%) (p = 0.039). The estimated 1, 3, and 5-year LR-free survival rates of patients in the Control and AMC Group were: 93.5%, 86.0%, 81.0% and 98.8%, 97.2%, 91.9%, respectively (p = 0.049). Univariate Cox analyses indicated that the use of the RF applicator was significantly associated with lower LR (HR = 0.29, 95% confidence interval 0.093-0.906, p = 0.033). The Control Group showed smaller coagulation widths than the AMC group (p < 0.001).

CONCLUSIONS

An additional application of RF on the top of the resection surface is associated with less local hepatic recurrence than the use of conventional techniques.

The Prognostic Value of Varying Definitions of Positive Resection Margin in Patients with Colorectal Cancer Liver Metastases

BACKGROUND

Varying definitions of resection margin clearance are currently employed among patients with colorectal cancer liver metastases (CRLM). Specifically, a microscopically positive margin (R1) has alternatively been equated with an involved margin (margin width = 0 mm) or a margin width < 1 mm. Consequently, patients with a margin width of 0-1 mm (sub-mm) are inconsistently classified in either the R0 or R1 categories, thus obscuring the prognostic implications of sub-mm margins.

METHODS

Six hundred thirty-three patients who underwent resection of CRLM were identified. Both R1 definitions were alternatively employed and multivariable analysis was used to determine the predictive power of each definition, as well as the prognostic implications of a sub-mm margin.

RESULTS

Five hundred thirty-nine (85.2%) patients had a margin width ≥ 1 mm, 42 had a sub-mm margin width, and 52 had an involved margin (0 mm). A margin width ≥ 1 mm was associated with improved survival vs. a sub-mm margin (65 vs. 36 months; P = 0.03) or an involved margin (65 vs. 33 months; P < 0.001). No significant difference in survival was detected between patients with involved vs. sub-mm margins (P = 0.31). A sub-mm margin and an involved margin were both independent predictors of worse OS (HR 1.66, 1.04-2.67; P = 0.04, and HR 2.14, 1.46-3.16; P < 0.001, respectively) in multivariable analysis. Importantly, after combining the two definitions, patients with either an involved margin or a sub-mm margin were associated with worse OS in multivariable analysis (HR 1.94, 1.41-2.65; P < 0.001).

CONCLUSIONS

Patients with involved or sub-mm margins demonstrated a similar inferior OS vs. patients with a margin width > 1 mm. Consequently, a uniform definition of R1 as a margin width < 1 mm should perhaps be employed by future studies.

Impact of monopolar radiofrequency coagulation on intraoperative blood loss during liver resection: a prospective randomised controlled trial

PURPOSE

To evaluate the impact of using monopolar thermal coagulation based on radiofrequency (RF) currents on intraoperative blood loss during liver resection.

MATERIALS AND METHODS

A prospective randomised controlled trial was planned. Patients undergoing hepatectomy were randomised into two groups. In the control group (n = 10), hemostasis was obtained with a combination of stitches, vessel-sealing bipolar RF systems, sutures or clips. In the monopolar radiofrequency coagulation (MRFC) group (n = 18), hemostasis was mainly obtained using an internally cooled monopolar RF electrode.

RESULTS

No differences in demographic or clinical characteristics were found between groups. Mean blood loss during liver resection in the control group was more than twice that of the MRFC group (556 ± 471 ml vs. 225 ± 313 ml, p = .02). The adjusted mean bleeding/transection area was also significantly higher in the control group (7.0 ± 3.3 ml/cm² vs. 2.8 ± 4.0 ml/cm², p = .006). No significant differences were observed in the rate of complications between the groups.

CONCLUSIONS

The findings suggest that the monopolar electrocoagulation created with an internally cooled RF electrode considerably reduces intraoperative blood loss during liver resection.

Impact of surgical margin clearance for resection of secondary hepatic malignancies

Over the past several decades, there has been increasing discussion regarding the optimal management of secondary liver malignancies. Traditionally, resection has only been recommended if it could be accomplished with negative microscopic margins of at least 10 mm. However, many investigators have pushed this limit to offer resection to patients with narrower margins. We review the data regarding the impact of margin clearance on outcomes for patients undergoing hepatic metastasectomy.

A comparative evaluation of ablations produced by high-frequency coagulation-, argon plasma coagulation-, and cryotherapy devices in porcine liver

INTRODUCTION

Hepatic resection is the only curative treatment option for primary or metastatic malignancies of the liver. Although R1 resections can also lead to prolonged survival, the main surgical goal is complete tumor resection (R0). To achieve this, additional treatment of the resection margin with ablation devices is discussed. Using a porcine in vivo model, we therefore analyzed the effect of different ablation devices on depth and completeness of hepatic parenchymal cell destruction.

METHODS

Swabian-Hall strain pigs underwent ablation on the surface of the right, middle, or left liver lobe using seven different types of high-frequency (HF)-, cryotherapy (Cryo)-, or argon plasma coagulation (APC) devices. Penetration depth and volume were analyzed from histological sections. Severity of parenchymal cell destruction was assessed by a histomorphological score.

RESULTS

The greatest penetration depth was achieved with Cryo (10.4 ± 1.7 mm), whereas HF and APC exhibited a smaller penetration depth. However, HF and APC compared to Cryo achieved complete destruction of the intralobular architecture and hepatocellular morphology depending on the application time and the adjusted power.

CONCLUSION

HF, APC, and Cryo applied to the liver surface induce different parenchymal penetration depth and cell destruction. HF and APC are considered to be standard surgical instruments and therefore recommended as standard treatment, whereas Cryo may be used only if particularly deep penetration is required.

Low-dose steroid pretreatment ameliorates the transient impairment of liver regeneration

AIM: To determine if liver regeneration (LR) could be disturbed following radiofrequency (RF) ablation and whether modification of LR by steroid administration occurs.

METHODS: Sham operation, partial hepatectomy (PH), and partial hepatectomy with radiofrequency ablation (PHA) were performed on adult Fisher 344 rats. We investigated the recovery of liver volume, DNA synthetic activities, serum cytokine/chemokine levels and signal transducers and activators of transcription 3 DNA-binding activities in the nucleus after the operations. Additionally, the effects of steroid (dexamethasone) pretreatment in the PH group (S-PH) and the PHA group (S-PHA) were compared.

RESULTS: The LR after PHA was impaired, with high serum cytokine/chemokine induction compared to PH, although the ratio of the residual liver weight to body weight was not significantly different. Steroid pretreatment disturbed LR in the S-PH group. On the other hand, low-dose steroid pretreatment improved LR and suppressed tumor necrosis factor (TNF)-α elevation in the S-PHA group, with recovery of STAT3 DNA-binding activity. On the other hand, low-dose steroid pretreatment improved LR and suppressed TNF-α elevation in the S-PHA group, with recovery of STAT3 DNA-binding activity.

CONCLUSION: LR is disturbed after RF ablation, with high serum cytokine/chemokine induction. Low-dose steroid administration can improve LR after RF ablation with TNF-α suppression.

Laparoscopic hepatectomy: a systematic review, meta-analysis, and power analysis

PURPOSE

A previous meta-analysis study demonstrated that bleeding and the duration of the hospital stay following laparoscopic hepatectomy (Lap) were significantly smaller and shorter, respectively, than for patients undergoing an open approach (Op). The aim of the present study was to re-evaluate perioperative variables and adverse outcomes in patients undergoing Lap versus (vs) Op after 2000.

METHODS

A PubMed and Ovid Medline search identified clinical studies that compared the outcomes of Lap vs Op patients after 2000. A meta-analysis and power analysis were performed.

RESULTS

Operative time was not significantly different between the two approaches (95% confidence interval [CI]: -0.063 to 0.992). Patient bleeding in the Lap group was significantly lower than in the Op group (95% CI: -1.027 to -0.390). Complications with Lap patients were significantly less frequent (95% CI: 0.231-0.642), and the duration of the hospital stay for Lap patients was significantly shorter (95% CI: -0.950 to -0.530) than for Op patients. Only one paper presented 80% power with 0.05 α-errors in all four outcomes, whereas four studies did not have sufficient statistical power.

CONCLUSIONS

The clinical benefits of Lap include a smaller incidence of complications and a shorter duration of hospital stay at the current time. Several studies had too few cases to sufficiently evaluate these factors, although other studies were appropriately analyzed.

Selecting treatment for hepatocellular carcinoma based on the results of hepatic resection and local ablation therapy

BACKGROUND

First-line treatment for <or=3 hepatocellular carcinomas (HCCs) <or=3 cm in size remains controversial. The superiority of survival benefit needs to be clarified between these modalities for such lesions.

METHODS

We examined post-treatment survival of 144 consecutive HCC patients who underwent hepatectomy and of 56 consecutive HCC patients who underwent thermal ablation therapy limited to the HCC (<or=3 cm, <or=3 lesions).

RESULTS

Pretreatment liver function was significantly worse and prevalence of Child-Pugh classification B/C was significantly higher in the ablation group compared to the hepatectomy group. Prevalence of tumor recurrence after treatment did not differ significantly between groups, irrespective of solitary or multiple HCC. In solitary HCC, overall survival rates in both groups did not differ significantly. Even in Child-Pugh B patients, survival was not significantly different between hepatectomy and ablation. In HCC with 2-3 lesions <or=3 cm, overall survival was significantly longer with hepatectomy than with ablation and mean survival periods in the hepatectomy and ablation groups were 4.5 and 1.2 years, respectively.

CONCLUSION

In cases of multiple small HCCs, hepatic resection is recommended over local ablation therapy as the first-line treatment in cases where liver function has been preserved.

Evaluation of a bipolar radiofrequency device for laparoscopic hepatic resection: technique and clinical experience in 18 patients

BACKGROUND

The increased frequency of laparoscopic hepatic resection as a principal or adjunct component of patient care has driven the need for and development of efficient and safe hepatic parenchymal transection technologies. At present, various devices are available for pre-coagulation transection (PCT) of hepatic parenchyma with the intent of minimizing procedure-associated postoperative haemorrhage and bile leak. This report presents the evaluation of a novel bipolar radiofrequency (RF) energy device for PCT used for laparoscopic hepatic resection.

METHODS

Patients undergoing laparoscopic hepatic resection using the Enseal device (SurgRx Inc.) were identified from the prospectively maintained hepatobiliary database. Information on patient demographics, procedures and postoperative complications was collected and analysed; complications were grouped into early (at <30 days) and late (at > or = 30 days) events.

RESULTS

A total of 18 patients, of whom 13 had malignant tumours (12 colorectal metastases and one hepatocellular carcinoma) and five had benign tumours (two hepatic adenomas and three haemangiomas) underwent 18 hepatic procedures, including two formal hemi-hepatectomies, four left lateral sections, three posterior sections and nine atypical non-anatomic resections. Estimated blood loss did not differ from institutional historical control data; no postoperative haemorrhage, bile leaks or hepatic abscess or necrosis were identified (n = 18).

CONCLUSIONS

This initial experience using the laparoscopic bipolar RF device demonstrates an acceptable safety profile in terms of the outcomes analysed.