Pringle maneuver exacerbates systemic inflammatory response and multiple-organ injury induced by extended liver radiofrequency ablation

How Biology Guides the Combination of Locoregional Interventional Therapies and Immunotherapy for Hepatocellular Carcinoma: Cytokines and Their Roles

As most patients with hepatocellular carcinoma (HCC) are diagnosed at the intermediate or advanced stage and are no longer eligible for curative treatment, the overall survival rate of HCC remains unsatisfactory. Locoregional interventional therapies (LITs), and immune checkpoint inhibitor (ICI)-based immunotherapy, focus on treating HCC, but the efficacy of their individual application is limited. Therefore, the purpose of this review was to discuss the biological roles of cytokines and their therapeutic potential in the combination therapy of LITs and ICI-based immunotherapy. The two common techniques of LITs are ablative and transarterial therapies. Whether LITs are complete or incomplete can largely affect the antitumor immune response and tumor progression. Cytokines that induce both local and systemic responses to LITs, including interferons, interleukins, chemokines, TNF-α, TGF-β, VEGF, and HGF, and their roles are discussed in detail. In addition, specific cytokines that can be used as therapeutic targets to reduce immune-related adverse events (irAEs) are introduced. Overall, incomplete LITs in a tumor, combined with specific cytokines, are thought to be effective at improving the therapeutic efficacy and reducing treatment-induced irAEs, and represent a new hope for managing unresectable HCC.

A systematic review and meta-analysis comparing tumor progression and complications between radiofrequency ablation and thyroidectomy for papillary thyroid carcinoma

BACKGROUND

Papillary thyroid cancer (PTC) is the most frequent thyroid cancers worldwide. The efficacy and acceptability of radiofrequency ablation (RFA) in the treatment of PTC have been intensively studied. The aim of this study is to focus on extra detailed that may influent for PTC or papillary thyroid microcarcinoma (PTMC).

MATERIALS AND METHODS

We identified a total of 1,987 records of a primary literature searched in PubMed, Embase, Cochrane Library, and Google Scholar by key words, from 2000 to 2022. The outcome of studies included complication, costs, and local tumor progression. After scrutiny screening and full-text assessment, six studies were included in the systematic review. Heterogeneity was estimated using I2, and the quality of evidence was assessed for each outcome using the GRADE guidelines.

RESULTS

Our review enrolled 1,708 patients reported in six articles in the final analysis. There were 397 men and 1,311 women in the analysis. Two of these studies involved PTC and four focused on PTMC. There were 859 patients in the RFA group and 849 patients in the thyroidectomy group. By contrast, the tumor progression of RFA group was as same as that surgical groups [odds ratio, 1.31; 95% CI, 0.52-3.29; heterogeneity (I2 statistic), 0%, p = 0.85]. The risk of complication rates was significantly lower in the RFA group than that in the surgical group [odds ratio, 0.18; 95% CI, 0.09-0.35; heterogeneity (I2 statistic), 40%, p = 0.14].

CONCLUSIONS

RFA is a safe procedure with a certain outcome for PTC. RFA can achieve a good efficacy and has a lower risk of major complications.

Percutaneous radiofrequency ablation near large vessels in beagle livers: the impact of time and distance on the ablation zone

PURPOSE

To investigate the effects of ablation time and distance between the radiofrequency ablation (RFA) electrode tip and a large vessel on the ablation zone in beagle livers.

METHODS

Sixty-one percutaneous RFA coagulation zones were created near large vessels in 10 beagle livers in vivo. The ablated lesions were divided into four groups based on ablation time and distance between the electrode tip and a large vessel (group A, 3 min 0.5 cm; group B, 3 min 0 cm; group C, 5 min 0.5 cm; group D, 5 min 0 cm). The ablated area, long-axis diameters, short-axis diameters, and vessel wall injury were examined.

RESULTS

With a fixed ablation time, the ablation zone created with the electrode tip at 0.5 cm from the large vessel was significantly larger than at 0 cm (p < .05). At a fixed distance between the electrode tip and vessel, the ablation zone created for 5 min was significantly larger than for 3 min (p < .05). The frequency of vessel wall injury in the 0 cm groups was significantly higher than that in the 0.5 cm groups (37.5% vs. 6.9%; p = .003, odds ratio, 7.43). The ratio of width to depth (Dw/Dz) was larger in the 0.5 cm groups than in the 0 cm groups (p < .001).

CONCLUSION

The ablation zone increased with longer ablation times and greater distances between the RFA tip and large vessels for perivascular lesions. The distance between the needle tip and blood vessels is an important factor that affects the overall ablation outcome.

Perivascular vital cells in the ablation center after multibipolar radiofrequency ablation in an in vivo porcine model

Multibipolar radiofrequency ablation (RFA) is an advanced ablation technique for early stage hepatocellular carcinoma and liver metastases. Vessel cooling in multibipolar RFA has not been systematically investigated. The objective of this study was to evaluate the presence of perivascular vital cells within the ablation zone after multibipolar RFA. Multibipolar RFA were performed in domestic pigs in vivo. Three internally cooled bipolar RFA applicators were used simultaneously. Three experimental settings were planned: (1) inter-applicator-distance: 15 mm; (2) inter-applicator-distance: 20 mm; (3) inter-applicator-distance: 20 mm with hepatic inflow occlusion (Pringle maneuver). A vitality staining was used to analyze liver cell vitality around all vessels in the ablation center with a diameter > 0.5 mm histologically. 771 vessels were identified. No vital tissue was seen around 423 out of 429 vessels (98.6%) situated within the central white zone. Vital cells could be observed around major hepatic vessels situated adjacent to the ablation center. Vessel diameter (> 3.0 mm; p < 0.05) and low vessel-to-ablation-center distance (< 0.2 mm; p < 0.05) were identified as risk factors for incomplete ablation adjacent to hepatic vessels. The vast majority of vessels, which were localized in the clinically relevant white zone, showed no vital perivascular cells, regardless of vessel diameter and vessel type. However, there was a risk of incomplete ablation around major hepatic vessels situated directly within the ablation center. A Pringle maneuver could avoid incomplete ablations.

Prediction of perioperative outcome after hepatic resection for pediatric patients

Background

Hepatic resection is associated with significant risk of morbidity and mortality. Optimising the surgical techniques and perioperative management may improve in operative morbidity and mortality. However, perioperative variables involved in the improvement for postoperative outcomes in pediatric hepatectomy have not been defined.

Methods

We retrospectively reviewed 156 consecutive pediatric patients who underwent hepatectomy at our center (an academic tertiary care hospital) between 2006 and 2016. Baseline demographic variables, intraoperative variables, complications, and hospital stay were explored. The patients were further investigated using univariate and multivariate analysis for the factors involved in the postoperative outcomes.

Results

Of the conditions requiring resections, malignant and benign liver diseases accounted for 47.4% (74/156) and 52.6% (82/156), respectively. The overall hospital mortality was 1.9% (3/156) and the overall postoperative complication rate was 44.2% (69/156). Anatomical resections were performed in 128 patients (82.1%), including 14(9.0%) extended hepatectomies. Eighty percent of patients had three or more segments resected. The median operative time was 167.7 (65–600) minutes and median estimated blood loss was 320.1(10–1600) mL. On multivariate analysis, the estimated blood loss (EBL) (mL) (OR, 2.19; 95CI, 1.18–3.13; p = 0.016), extent of hepatectomy (OR, 1.81; 95CI, 1.06–2.69; p = 0.001) and pringle maneuver (OR, 1.38; 95CI, 1.02–1.88; p = 0.038) were the independent predictors of postoperative complications.

Conclusions

Extent of hepatectomy and estimated blood loss are largely responsible for the perioperative complications. With the surgical devices and management amelioration, like pringle maneuver, the treatment planning may be optimize in pediatric liver resection.

Intermittent Pringle maneuver may be beneficial for radiofrequency ablations in situations with tumor-vessel proximity

Background

Radiofrequency ablation (RFA) represents a treatment option for non-resectable liver malignancies. Larger ablations can be achieved with a temporary hepatic inflow occlusion (Pringle maneuver - PM). However, a PM can induce dehydration and carbonization of the target tissue. The objective of this study was to evaluate the impact of an intermittent PM on the ablation size.

Methods

Twenty-five multipolar RFAs were performed in porcine livers ex vivo. A perfused glass tube was used to simulate a natural vessel. The following five test series (each n=5) were conducted: (1) continuous PM, (2-4) intermittent PM, and (5) no PM. Ablations were cut into half. Ablation area, minimal radius, and maximal radius were compared.

Results

No change in complete ablation size could be measured between the test series (p>0.05). A small rim of native liver tissue was observed around the glass tube in the test series without PM. A significant increase of ablation area could be measured on the margin of the ablations with an intermittent PM, starting without hepatic inflow occlusion (p<0.05).

Conclusion

An intermittent PM did not lead to smaller ablations compared to a continuous or no PM ex vivo. Furthermore, an intermittent PM can increase the ablation area when initial hepatic inflow is succeeded by a PM.

Immune and Inflammatory Responses of the Intestinal Mucosa following Extended Liver Radiofrequency Ablation

Background and Aim

Extended liver radiofrequency ablation (RFA) has been shown to disrupt gut barrier integrity with subsequent bacterial translocation. The aim of the present project was to study the immune and inflammatory responses of the intestinal mucosa after extended RFA of the liver.

Methods

Twelve Wistar rats were either subjected to RFA of the left lateral hepatic lobe (approximately 30% of the liver mass) after midline laparotomy (group RFA, n = 6) or sham operation (group Sham, n = 6). Forty-eight hours later, ileal tissue specimens were excised for immunohistochemical assessment of CD68⁺ macrophages, CD4⁺ T-lymphocytes, CD8⁺ T-lymphocytes, mucosal addressin cell adhesion molecule-1 (MAdCAM-1), tumor necrosis factor-α (TNFα), interleukin-6 (IL-6), and nuclear factor-κB (NFκB) expression.

Results

Immune response biomarkers were upregulated in the RFA group. Expression of CD4⁺ and CD8⁺ T-lymphocytes was moderate, while that of CD68⁺ macrophages and MAdCAM-1 was high. Inflammatory response biomarkers were also upregulated in the RFA group. TNFα, IL-6, and NFκB expression was low, moderate, and high, respectively.

Conclusions

Extended liver RFA evokes both immune and inflammatory responses of the gut mucosa.

Short- and long-term outcomes of hepatectomy with or without radiofrequency-assist for the treatment of hepatocellular carcinomas: a retrospective comparative cohort study

The objective of this study was to compare the short- and long-term outcomes of radiofrequency-assisted liver resection (RFLR) and conventional clamp-crushing liver resection (CCLR) and to evaluate the safety and efficiency of RFLR. Between January 2008 and December 2012, a total of 597 patients with hepatocellular carcinoma (HCC) who underwent curative hepatectomy were identified. A total of 272 patients underwent RFLR, and 325 patients received CCLR. The short- and long-term outcomes were compared. The patients in the RFLR and CCLR groups showed similar baseline characteristics. The RFLR group showed less intraoperative blood loss (485.5 vs. 763.2 mL, p = 0.003), a lower transfusion requirement rate (19.1 vs. 31.7%, p ≤ 0.01), shorter surgery duration (211 vs. 296 min, p ≤ 0.01) and a lower vascular inflow occlusion rate (25.7 vs. 33.8%, p = 0.032). No significant postoperative changes in bilirubin or liver enzymes were observed in the two groups. The degree of postoperative complications and morbidity did not significantly differ between the two groups. There were no significant differences in the 1-, 2- and 3-year overall survival rates (73.8%, 58.5%, and 55.7% vs. 80.8%, 65.8%, and 56.2%, respectively) or disease-free rates (51.9%, 47.2%, and 46.0% vs. 54.5%, 44.9%, and 38.5%, respectively) between the RFLR and CCLR groups. These results suggested RFLR was a safe and efficient method for patients with HCC. RFLR was associated with decreased blood loss, fewer blood transfusions, shorter surgery times and less vascular inflow occlusion application. The RFLR group did not show increased liver injury or postoperative morbidity or mortality.

Liver radiofrequency ablation compromises the biological gut barrier

AIM

Liver radiofrequency ablation (RFA) has been shown to disrupt the mechanical component of the gut barrier. The aim of the present study was to investigate the consequences of liver RFA on the biological gut barrier in terms of the effects of bile production rate and bowel inflammatory state on intestinal microflora balance.

METHOD

A total of 25 New Zealand rabbits were assigned to five groups (n = 5 per group): group CBD: subjected to common bile duct (CBD) extracorporeal bypass; group CBD-RFA: subjected to CBD bypass plus one session of open liver RFA; group RFA: subjected to liver RFA; group sham: subjected to sham operation; and group TBD: subjected to total bile deviation (TBD). In groups CBD and CBD-RFA, bile production rate was assessed for 48 h. In groups sham and RFA, measurement of biliary glycine conjugates of cholic and deoxycholic acid levels, histopathologic examination of the non-ablated liver tissue, morphometric analysis, and histopathologic examination of the terminal ileum and microbiological analysis of fecal and tissue samples collected from the jejunum and the cecum (and in group TBD) were performed at 48 h post-operation.

RESULTS

One session of liver RFA resulted in ablation of 18.7 ± 2.7% of liver weight. Following liver RFA, bile production rate was reduced, while the levels of biliary bile salts were not affected. There was mild injury of the non-ablated liver parenchyma, mild intestinal wall inflammation, intestinal mucosa atrophy, and intestinal microbial population overgrowth.

CONCLUSION

Reduced in bile production and mild bowel inflammation secondary to liver RFA impaired the biological gut barrier as manifested by intestinal microflora imbalance.

Curative resection of hepatocellular carcinoma using modified Glissonean pedicle transection versus the Pringle maneuver: a case control study

OBJECTIVE

The Glissonean pedicle transection method of liver resection has been found to shorten operative time and minimize intraoperative bleeding during liver segmentectomy. We have compared the feasibility, effectiveness, and safety of the Glissonean pedicle transection method with the Pringle maneuver in patients undergoing selective curative resection of large hepatocellualr carcinoma (HCC).

METHODS

Eligible patients with large (> 5 cm) nodular HCC (n = 50) were assigned to undergo curative hepatectomy using the Glissonean pedicle transection method (n = 25) or the Pringle maneuver (n = 25). Partial interruption of the infrahepatic inferior vena cava was incorporated to further reduce bleeding from liver transection. The primary outcome measure was postoperative changes in liver function from baseline. Secondary outcomes included operating time, volume of intraoperative blood loss/transfusion, and time to resolution of ascites.

RESULTS

The two groups were comparable in age, sex, site and size of the liver tumor, segment or lobe intended to be resected, and liver function reserve, and the results were not significant statistically. All patients underwent successful major hepatectomies using the assigned method, with the extent of major hepatectomy comparable in the two groups (P = 0.832). The Glissonean approach was associated with shorter hepatic inflow interruption (30.0 ± 12.0 min vs. 45.0 ± 13.0 min, P < 0.001), lower volume of blood loss (145.0 ± 20.0 mL vs. 298.0 ± 109.0 mL, P < 0.001), reduced requirement for transfusion (0.0 ± 0.0 mL vs. 200.0 ± 109.0 mL, P < 0.0001), and more rapid resolution of ascites (9.5 ± 1.2 d vs. 15.3 ± 2.4 d, P < 0.001). Postoperative liver function measures were comparable in the two groups, and the results were not significant statistically.

CONCLUSION

The Glissonean pedicle transection method is a feasible, effective, and safe technique for hepatic inflow control during the curative resection of large nodular HCCs.