Major complications of ultrasound-guided percutaneous radiofrequency ablations for liver malignancies: single center experience

Risk Factors for Hospitalization Duration Longer Than 24 Hours Following Percutaneous Radiofrequency Ablation of Liver Tumours

PURPOSE

Prior studies have described complications of radiofrequency ablation (RFA) of liver tumours. The aim of this study was to identify risk factors for hospitalization duration longer than 24 hours following RFA of liver tumours.

METHODS

This retrospective, single-centre study included patients with liver tumours undergoing RFA between October 2017 and July 2020. Medical records were reviewed to collect patient, tumours, and procedure characteristics for each RFA session. The association between potential risk factors and duration of hospitalization (less than or more than 24 hours) was analyzed using univariate and multivariate logistic regressions.

RESULTS

Our study included 291 patients (mean age: 65.2 ± 11.2 [standard deviation]; 201 men) undergoing 324 RFA sessions. Sixty-eight sessions (21.0%) resulted in hospitalization of more than 24 hours. Multivariate analysis identified each additional needle insertion per session (OR 1.4; 95% CI [1.1-1.9]; P = .02), RFA performed in segment V (OR 2.8; 95% CI [1.4-5.7]; P = .004), and use of artificial pneumothorax (OR 14.5; 95% CI [1.4-146.0]; P = .02) as potential risk factors. A history of hepatic encephalopathy (OR 2.6; 95% CI [1.1-6.0]; P = .03) was only significant in univariate analysis. Post-hoc, subgroup analysis of patients with hepatocellular carcinoma (69.8%) did not identify other risk factors.

CONCLUSION

Risk factors for a hospitalization duration longer than 24 hours include a higher number of needle insertions per session, radiofrequency ablation in segment V, and use of an artificial pneumothorax.

Hemocholecyst caused by accidental injury associated with radiofrequency ablation for hepatocellular carcinoma: A case report

BACKGROUND

Radiofrequency ablation (RFA) is an effective and safe treatment for hepatocellular carcinoma that features a lower incidence of serious complications than surgical resection. Hemocholecyst caused by RFA is a rare complication of secondary damage to the intrahepatic bile duct that results in hemobilia.

CASE SUMMARY

Here we report on a case of a hemocholecyst caused by accidental injury during RFA that induced hematemesis and melena. Digital subtraction angiography revealed no gallbladder arterial injuries. After conservative treatment and transcatheter arterial chemoembolization, the patient's condition stabilized, and she was discharged 1 wk later.

CONCLUSION

Therefore, when performing interventional procedures such as RFA, clinicians must be vigilant because even minor injuries can lead to serious complications such as hemocholecyst.

The frequency and risk factors of major complications after thermal ablation of liver tumours in 2,084 ablation sessions

Background

To assess the frequency of major complications after thermal ablation of liver tumours and to determine risk factors for adverse events.

Methods

A retrospective study was conducted between January 2015 and January 2021. A total of 2,084 thermal ablation sessions in 1,592 patients with primary and metastatic liver tumours were evaluated. The frequency of major complications was evaluated according to the Society of Interventional Radiology Standards, and putative predictors of adverse events were analysed using simple and multivariate logistic regression.

Results

Thermal ablation-related mortality was 0.1% (2/2,084), with an overall major complication rate of 5.6% (117/2,084). The most frequent major complication was symptomatic pleural effusion (2.9%, 60/2,084). Multivariate logistic regression analysis revealed that a total maximum diameter of lesions >3 cm, microwave ablation (MWA) and MWA combined with radiofrequency ablation, intrahepatic cholangiocarcinoma and postoperative systemic inflammatory response syndrome were independent prognostic factors for major complications.

Conclusions

Thermal ablation of liver tumours is a safe procedure with an acceptable incidence of major complications. The risk factors identified in this study will help to stratify high-risk patients.

Hemostasis using re-radiofrequency ablation for hepatic tract bleeding after ultrasound-guided percutaneous radiofrequency ablation of hepatic tumors

OBJECTIVE

To evaluate the hemostatic efficacy of re-radiofrequency ablation (re-RFA) for hepatic tract bleeding after ultrasound-guided RFA of hepatic tumors.

METHODS

A total of 4679 percutaneous ultrasound-guided RFA procedures were performed for hepatic tumors at Samsung Medical Center between January 2012 and December 2020. We identified patients who had hepatic tract bleeding after RFA by reviewing radiologic reports and ultrasound images and investigated the measures taken to control the bleeding and their outcomes. We also identified patients who had a significant peritoneal hematoma on immediate post-RFA CT or underwent transarterial embolization to control hepatic bleeding after RFA of hepatic tumors.

RESULTS

In total, 91 patients with tract bleeding after RFA were identified. As initial measures to control the bleeding, external compression, re-RFA, and observation were performed in 71 (78%), 17 (19%), and 3 (3%) patients, respectively. Hemostasis using re-RFA was attempted to control tract bleeding in 40 patients as an initial measure or an additional measure after other initial efforts. In all 40 patients, the bleeding stopped after re-RFA on Doppler ultrasound, and there was no active bleeding on the immediate follow-up CT. During the study period, in the years when re-RFA was performed frequently, the number of transarterial embolizations to control tract bleeding and significant peritoneal hematoma formation tended to be low.

CONCLUSION

Hemostasis using re-RFA of the needle tract is effective in controlling tract bleeding after ultrasound-guided RFA of hepatic tumors.

ADVANCES IN KNOWLEDGE

Re-RFA is a simple, safe, and effective method to control tract bleeding.

Gastrointestinal tract injuries after thermal ablative therapies for hepatocellular carcinoma: A case report and review of the literature

BACKGROUND

Radiofrequency ablation (RFA) and microwave ablation (MWA) represent the standard of care for patients with early hepatocellular carcinoma (HCC) who are unfit for surgery. The incidence of reported adverse events is low, ranging from 2.4% to 13.1% for RFA and from 2.6% to 7.5% for MWA. Gastrointestinal tract (GIT) injury is even more infrequent (0.11%), but usually requires surgery with an unfavourable prognosis. Due to its low incidence and the retrospective nature of the studies, the literature reporting this feared complication is heterogeneous and in many cases lacks information on tumour characteristics, comorbidities and treatment approaches.

CASE SUMMARY

A 77-year-old man who had undergone extended right hepatectomy for HCC was diagnosed with early disease recurrence with a small nodule compatible with HCC in the Sg4b segment of the liver with a subcapsular location. He was treated with percutaneous RFA and a few week later he was urgently admitted to the Surgery ward for abdominal pain and fever. A subcutaneous abscess was diagnosed and treated by percutaneous drainage. A fistulous tract was then documented by the passage of contrast material from the gastric antrum to the abdominal wall. The oesophagogastroduodenoscopy confirmed a circular wall defect at the lesser curvature of gastric antrum, leading directly to the purulent abdominal collection. An over-the-scope clip (OTSC) was used to successfully close the defect

CONCLUSION

This is the first reported case of RFA-related GIT injury to have been successfully treated with an OTSC, which highlights the role of this endoscopic treatment for the management of this complication.

Radiofrequency Ablation Using a Separable Clustered Electrode for the Treatment of Hepatocellular Carcinomas: A Randomized Controlled Trial of a Dual-Switching Monopolar Mode Versus a Single-Switching Monopolar Mode

OBJECTIVE

This study aimed to prospectively compare the efficacy, safety, and mid-term outcomes of dual-switching monopolar (DSM) radiofrequency ablation (RFA) to those of conventional single-switching monopolar (SSM) RFA in the treatment of hepatocellular carcinoma (HCC).

MATERIALS AND METHODS

This single-center, two-arm, parallel-group, randomized controlled study was approved by the Institutional Review Board. Written informed consent was obtained from all patients upon enrollment. A total of 80 patients with 94 HCC nodules were randomized into either the DSM-RFA group or SSM-RFA group in a 1:1 ratio, using a blocked randomization method (block size 2). The primary endpoint was the minimum diameter of the ablation zone per unit time. The secondary endpoints included other technical parameters, complication rate, technique efficacy, and 2-year clinical outcomes.

RESULTS

Significantly higher ablation energy per unit time was delivered to the DSM-RFA group than to the SSM-RFA group (1.7 ± 0.2 kcal/min vs. 1.2 ± 0.3 kcal/min; p < 0.001). However, no significant differences were observed between the two groups for the analyzed variables, including primary endpoint, regarding size of the ablation zone and ablation time. Major complication rates were 4.9% in the DSM-RFA group and 2.6% in the SSM-RFA group (p = 1.000). The 2-year local tumor progression (LTP) rates of the HCC nodules treated using DSM-RFA and SSM-RFA were 8.5% and 4.7%, respectively (p = 0.316). The 2-year LTP-free survival rates of patients in the DSM-RFA and SSM-RFA groups were 90.0% and 94.4%, respectively (p = 0.331), and the 2-year recurrence-free survival rates were 54.9% and 75.7%, respectively (p = 0.265).

CONCLUSION

Although DSM-RFA using a separable clustered electrode delivers higher ablation energy than SSM-RFA, its effectiveness failed to show superiority over SSM-RFA in the treatment of HCC.

Imaging and Management of Liver Cancer

Imaging of primary hepatic neoplasms in patients at risk for hepatocellular carcinoma (HCC) and in patients with otherwise normal livers relies on proper multiphase image acquisition technique, with emphasis on a high-quality, late arterial phase, using either CT or MRI for accurate image interpretation. The introduction of liver imaging reporting and data system in 2011, with subsequent multiple updates, the most recent in 2018, has provided standardization of image interpretation, reporting and management recommendations for liver observations in patients at risk for HCC. This review article will emphasize key points of imaging primary liver tumors with emphasis on liver imaging reporting and data system, including strengths of this system. We will also review imaging of less common primary liver tumors such as cholangiocarcinoma and angiosarcomas. Imaging pitfall associated with primary liver malignancies will be demonstrated as well as ways to mitigate them. Finally, imaging and reporting of findings following locoregional treatment of HCC will be reviewed.

Single-centre retrospective review of risk factors for local tumour progression and complications in radiofrequency ablation of 555 hepatic lesions

INTRODUCTION

This study aimed to assess safety, local tumour progression (LTP) and risk factors for LTP after radiofrequency ablation (RFA) of liver tumours in a single centre.

METHODS

All consecutive patients treated with RFA for liver tumours between January 2009 and October 2012 were included. Previously treated lesions that progressed were excluded. Using electronic medical records, the following data was captured: patient demographics, pre-procedural laboratory results, Child-Pugh status, tumour characteristics, development of tumoral seeding, RFA complications and LTP. Possible risk factors for LTP were identified using Cox regression.

RESULTS

In total, 555 liver tumours were treated in 337 patients. 483 (87.0%) hepatocellular carcinomas, 52 (9.4%) colorectal metastases and 20 (3.6%) other tumour types were treated. Mean tumour size was 2.1 ± 1.1 (range 0.4-6.8) cm. Mean follow-up duration was 387 days. 416 (75.0%) lesions had no LTP at the last imaging. 70 (12.6%) patients had minor complications requiring observation, while 7 (1.3%) patients had significant complications requiring prolonged hospitalisation or further interventions. Only one case of tumour seeding was detected. Using multivariate Cox regression, the following factors were statistically significant in predicting LTP: hilar location (relative ratio [RR] 3.988), colorectal metastases (RR 2.075), size (RR 1.290) and younger age (RR 0.982).

CONCLUSION

RFA of liver tumours is safe and effective, with a low significant complication rate of 1.3%. Hilar lesions are most prone to LTP, followed by lesions that were larger in size and colorectal metastases. 75.0% of patients showed no LTP at the last follow-up.

Complications after Radiofrequency Ablation for Hepatocellular Carcinoma: A Multicenter Study Involving 9,411 Japanese Patients

INTRODUCTION

Radiofrequency ablation (RFA) for hepatocellular carcinoma (HCC) is considered a safe and minimally invasive procedure. We previously reported that the mortality and complication rates for RFA were 0.038% (5/13,283 patients) and 3.54% (579 complications/16,346 procedures), respectively, from 1999 to 2010 (previous period). In this study, we investigated the clinical criteria for RFA and the mortality and complication rates from 2011 to 2015 (recent period).

METHODS

Data were collected from 25 centers by using a questionnaire developed by the Chugoku-Shikoku Society for Local Ablation Therapy of HCC. The criteria for RFA, RFA modification, use of image-guidance modalities, mortality, and complications during the previous and recent periods were compared.

RESULTS

We evaluated 11,298 procedures for 9,411 patients, including those that involved new devices (bipolar RFA and internally adjustable electrode system). The criterion of hepatic function for RFA increased from a Child-Pugh score ≤8 during the previous period to ≤9 during the recent period. The criteria regarding the tumor location and other risk factors have been expanded recently because of the increased use of several modifications of the RFA procedure and image-guidance modalities. The mortality rate was 0.064% (6/9,411 patients), and the complication rate was 2.92% (330 complications/11,298 procedures). There was no difference in mortality rates between the 2 periods (p = 0.38), but the complication rates was significantly lower during the recent period (p = 0.038).

DISCUSSION AND CONCLUSIONS

Our findings confirmed that RFA, including the use of new devices, is a low-risk procedure for HCC, despite the expansion of the criteria for RFA during the recent period.

Biliary stone disease in patients receiving somatostatin analogs for neuroendocrine neoplasms. A retrospective observational study

BACKGROUND

Somatostatin analogs are the backbone of neuroendocrine neoplasms treatment. Biliary stone disease is a potentially severe adverse event of somatostatin analogs: an increased incidence has been reported in somatostatin analogs-treated acromegalic patients, but studies on patients with neuroendocrine neoplasms are lacking.

AIMS

To evaluate biliary stone disease incidence and associated factors in a large series of patients treated with somatostatin analogs for neuroendocrine neoplasms.

METHODS

A prospectively-collected database of patients with a diagnosis of neuroendocrine neoplasms of any grade and site, treated with somatostatin analogs at our Institution between 1995 and 2017, was retrospectively analyzed. Patients' demographics and disease characteristics were analyzed to evaluate the incidence and the factors related to biliary stone disease.

RESULTS

Three-hundred patients were included; 101 (33.7%) patients underwent cholecystectomy before starting somatostatin analogs. Among 164 patients with gallbladder in situ and no history of stone disease, 60 (36.6%) developed gallstones after a mean of 36.7 months (range 1-239) from treatment start with a mean yearly incidence of 8.73%. Previous cholecystectomy was associated with a lower rate of development of gallstones (p < 0.001) or related complications (p = 0.017).

CONCLUSION

We observed a high incidence of biliary stone disease in patients treated with somatostatin analogs-treated for neuroendocrine neoplams. Previous cholecystectomy was the only factor associated with a lower occurrence of biliary stone disease.

The value of KRAS gene status in predicting local tumor progression of colorectal liver metastases following radiofrequency ablation

PURPOSE

We investigated the relationships between KRAS gene status and local tumor progression (LTP) of colorectal liver metastases (CLMs) after treatment with percutaneous ultrasound-guided radiofrequency ablation (RFA).

MATERIALS AND METHODS

Clinical and imaging data from 76 patients (154 lesions) with CLM who underwent percutaneous ultrasound-guided RFA and had KRAS gene test results between January 2012 and June 2016 were analyzed. The average lesion size was 2.3 ± 1.0 cm (range 0.9-5.7 cm); 38 cases (82 lesions) had wild-type KRAS, and 38 cases (72 lesions) had KRAS mutations.

RESULTS

The technique effectiveness was 98.1% (151/154), and the LTP rate was 18.2% (28/154) after RFA, which was performed between January 2012 and November 2017. The mean and median follow-up were 32.7 ± 2.5 and 32.0 ± 2.6 months (range 1-70 months), respectively. Cumulative LTP rates at 6 months and 1, 2 and 3 years post-RFA for all patients were 7.4, 14.5, 17.8 and 19.2%, respectively. The LTP rate for patients with mutant KRAS (27.8% [20/72]) was significantly higher than that in patients with wild-type KRAS (9.8% [8/82]; p = .004). The cumulative LTP rates at 6 months and 1, 2 and 3 years post-RFA were 4.0, 11.1, 11.1 and 11.1%, respectively, for patients with wild-type KRAS and 11.2, 18.4, 25.2 and 36.2%, respectively, for patient with mutant KRAS (p = .011). Univariate (p = .011) and multivariate analyses (p = .005) showed that KRAS genotype in liver metastases was predictive of LTP. Multivariate analysis also showed that ablation margin size (p< .001) and modified clinical risk score (CRS; p = .033) were independent prognostic factors for LTP.

CONCLUSIONS

KRAS gene status of liver metastatic lesions was associated with LTP rates after RFA of CLM. Ablation margin size and modified CRS were also independent prognostic factors for LTP.

A Case of Hypertensive Crisis without a Surge in Adrenal Hormones after Radiofrequency Ablation as a Treatment for Primary Hepatocellular Carcinoma

Radiofrequency ablation (RFA) is a minimally invasive procedure that has been considered as a relatively safe treatment for patients with small hepatocellular carcinoma (HCC). However, RFA has been shown to be associated with complications including mechanical and thermal damage. A 74-year-old man with hepatitis C virus-associated HCC was admitted to our hospital. Abdominal computed tomography revealed two lobulated-HCC in segments 4 and 5. He had no medical history of hypertension and cardiac disease. During RFA, blood pressure was elevated to 200/140 mmHg. There was no evidence of pulmonary embolism, aortic dissection, or ischemic heart disease. Laboratory findings for catecholamine surge were all within normal limits. After continuous intravenous nitroglycerin and oral beta-blocker treatment, patient's blood pressure gradually decreased and back within the normal range. Hypertensive crisis after RFA treatment for HCC is rare. Most reported cases of hypertensive crisis during RFA were related to adrenal gland injury with a release of catecholamine. In our case, the site of HCC was not close to the adrenal gland, and there was no evidence of catecholamine surge. Herein, we report a very rare case of hypertensive crisis without a surge in adrenal hormones after RFA treatment for HCC.

Early complications after percutaneous radiofrequency ablation for hepatocellular carcinoma: an analysis of 1,843 ablations in 1,211 patients in a single centre: experience over 10 years

AIM

To evaluate the incidence of adverse events and associated factors after radiofrequency ablation (RFA) in patients with hepatocellular carcinoma within 30 days.

MATERIALS AND METHODS

The early complications that occurred within 30 days after RFA at a single institution from January 2000 to July 2010 were reviewed in order to evaluate the morbidity, mortality, and risk factors associated with the complications. In total, 1,211 patients (845 men, 70.5%) with a mean age of 68 years (range, 27-88 years) underwent 1,843 RFA procedures.

RESULTS

The overall incidence rate of complications was 6.8% (125 cases). Major complications (n=36, 2%) included liver abscess (n=15, 0.8%), intraperitoneal bleeding (n=8, 0.4%), liver failure (n=5, 0.3%), variceal bleeding (n=3, 0.2%), haemothorax (n=2, 0.1%), cholecystitis (n=2, 0.1%), and bowel perforation (n=1, 0.1%). Among the minor complications (n=89, 4.8%), the most common was the post RFA syndrome accompanied by pain and fever (n=75, 4.1%). Other minor complications included significant pleural effusion (n=7, 0.4%), skin wound infection (n=4, 0.2%), and thermal injuries to the skin (n=3, 0.2%). Procedural infections significantly increased with tumour size (OR=1.379; 95% confidence interval [CI], 1.191-1.579; p<0.001), and multiple overlapping ablations (OR=1.118; 95% CI, 1.019-1.227, p=0.018). Thrombocytopenia (<50,000/μl), prothrombin time, and serum albumin level were significantly associated with post-RFA bleeding episodes (p=0.041, p=0.021, and p=0.003, respectively). The overall mortality rate was 0.3% (three cases of hepatic failure, two case of sepsis, and one case of renal failure).

CONCLUSIONS

RFA is a safe and effective local treatment for hepatocellular carcinoma. Careful selection of patients and appropriate RFA planning could decrease procedural mortality and morbidity.

Radiofrequency ablation of hepatocellular carcinoma: Mono or multipolar?

BACKGROUND AND AIMS

Thermo-ablation by radiofrequency is recognized as a curative treatment for early-stage hepatocellular carcinoma. However, local recurrence may occur because of incomplete peripheral tumor destruction. Multipolar radiofrequency has been developed to increase the size of the maximal ablation zone. We aimed to compare the efficacy of monopolar and multipolar radiofrequency for the treatment of hepatocellular carcinoma and determine factors predicting failure.

METHODS

A total of 171 consecutive patients with 214 hepatocellular carcinomas were retrospectively included. One hundred fifty-eight tumors were treated with an expandable monopolar electrode and 56 with a multipolar technique using several linear bipolar electrodes. Imaging studies at 6 weeks after treatment, then every 3 months, assessed local effectiveness. Radiofrequency failure was defined as persistent residual tumor after two sessions (primary radiofrequency failure) or local tumor recurrence during follow-up. This study received institutional review board approval (number 2014/77).

RESULTS

Imaging showed complete tumor ablation in 207 of 214 lesions after the first session of radiofrequency. After a second session, only two cases of residual viable tumor were observed. During follow-up, there were 46 local tumor recurrences. Thus, radiofrequency failure occurred in 48/214 (22.4%) cases. By multivariate analysis, technique (P < 0.001) and tumor size (P = 0.023) were independent predictors of radiofrequency failure. Failure rate was lower with the multipolar technique for tumors < 25 mm (P = 0.023) and for tumors between 25 and 45 mm (P = 0.082). There was no difference for tumors ≥ 45 mm (P = 0.552).

CONCLUSIONS

Compared to monopolar radiofrequency, multipolar radiofrequency improves tumor ablation with a subsequent lower rate of local tumor recurrence.

Complications after percutaneous ablation of liver tumors: a systematic review

BACKGROUND

Although ablation therapy has been accepted as a promising and safe technique for treatment of unrespectable hepatic tumors, investigation of its complications has been limited. A physician who performs ablation treatment of hepatic malignancies should be aware of the broad spectrum of complications. Proper management is possible only if the physician Performing ablation understands the broad spectrum of complications encountered after ablation.

OBJECTIVES

TO SYSTEMATICALLY REVIEW THE COMPLICATIONS AFTER DIFFERENT ABLATION MODALITIES: Radiofrequency ablation (RFA), microwave ablation (MWA) and Nano knife for the treatment of liver tumors and analyze possible risk factors that precipitate these complications.

SEARCH METHODS

WE PERFORMED ELECTRONIC SEARCHES IN THE FOLLOWING DATABASES: MEDLINE, EMBASE and COCHARNE. Current trials were identified through the Internet (from January 1, 2000 to January 1, 2014). We included only studies who specific mentioned complications after liver ablation therapy (RFA/MWA/Nano knife).

MAIN RESULTS

A total of 2,588 publications were identified, after detailed examination only 32 publications were included in the review. The included studies involved 15,744 participants. According to the type of technique, 13,044 and 2,700 patients were included for RFA and MWA. Analysis showed a pooled mortality of 0.15% for RFA, and 0.23% for MWA.

CONCLUSIONS

This systematic review gathers information from controlled clinical trials and observational studies which are vulnerable to different types of bias, never the less RFA and MWA can be considered safe techniques for the treatment of liver tumors.

Outcomes of Locoregional Tumor Therapy for Patients with Hepatocellular Carcinoma and Transjugular Intrahepatic Portosystemic Shunts

PURPOSE

Locoregional therapy for hepatocellular carcinoma (HCC) can be challenging in patients with a transjugular intrahepatic portosystemic shunt (TIPS). This study compares safety and imaging response of ablation, chemoembolization, radioembolization, and supportive care in patients with both TIPS and HCC.

METHODS

This retrospective study included 48 patients who had both a TIPS and a diagnosis of HCC. Twenty-nine of 48 (60%) underwent treatment for HCC, and 19/48 (40%) received best supportive care (i.e., symptomatic management only). While etiology of cirrhosis and indication for TIPS were similar between the two groups, treated patients had better baseline liver function (34 vs. 67% Child-Pugh class C). Tumor characteristics were similar between the two groups. A total of 39 ablations, 17 chemoembolizations, and 10 yttrium-90 radioembolizations were performed on 29 patients.

RESULTS

Ablation procedures resulted in low rates of hepatotoxicity and clinical toxicity. Post-embolization/ablation syndrome occurred more frequently in patients undergoing chemoembolization than ablation (47 vs. 15%). Significant hepatic dysfunction occurred more frequently in the chemoembolization group than the ablation group. Follow-up imaging response showed objective response in 100% of ablation procedures, 67% of radioembolization procedures, and 50% of chemoembolization procedures (p = 0.001). When censored for OLT, patients undergoing treatment survived longer than patients receiving supportive care (2273 v. 439 days, p = 0.001).

CONCLUSIONS

Ablation appears to be safe and efficacious for HCC in patients with TIPS. Catheter-based approaches are associated with potential increased toxicity in this patient population. Chemoembolization appears to be associated with increased toxicity compared to radioembolization.

Comparative study of percutaneous radiofrequency ablation and hepatic resection for small, poorly differentiated hepatocellular carcinomas

AIM

Histologically, poorly differentiated hepatocellular carcinomas (HCC) are considered highly malignant. Here, we aimed to evaluate the relative efficacy and safety of hepatic resection or radiofrequency ablation (RFA) for treating this malignancy.

METHODS

Between April 2004 and May 2011, we enrolled 48 patients who had poorly differentiated HCC that had been diagnosed postoperatively by pathological assessment. All the tumors had a maximum diameter of 3 cm and all patients had three or less tumors. Fifteen of these patients underwent hepatic resection (HR group) and 33 patients underwent RFA (RF group). The patient background, tumor characteristics, overall survival rate and recurrence-free survival rate were assessed in both groups.

RESULTS

The mean maximum tumor diameter was 2.5 and 2.0 cm in the HR and RF groups, respectively. The prothrombin activity level was 94% and 86% in the HR and RF groups, respectively. The 1-, 3- and 5-year cumulative survival rates were 89.1%, 68.7% and 68.7%, respectively, in the HR group, and 59.2%, 40.9% and 32.7%, respectively, in the RF group. The 1-, 3- and 5-year recurrence-free survival rates were 85.1%, 64.8% and 48.6%, respectively, in the HR group, and 29.0%, 7.2% and 7.2%, respectively, in the RF group. There was a significant difference between these groups (P < 0.05).

CONCLUSION

As hepatic resection has greater efficacy than RFA in the treatment of poorly differentiated HCC, even in cases with a small tumor size, we recommend its use for this malignancy.

MAFR. Complications of radiofrequency ablation of hepatic tumors: Frequency and risk factors

Radiofrequency ablation (RFA) has become an important option in the therapy of primary and secondary hepatic tumors. Surgical resection is still the best treatment option, but only a few of these patients are candidates for surgery: multilobar disease, insufficient liver reserve that will lead to liver failure after resection, extra-hepatic disease, proximity to major bile ducts and vessels, and co-morbidities. RFA has a low mortality and morbidity rate and is considered to be safe. Thus, complications occur and vary widely in the literature. Complications are caused by thermal damage, direct needle injury, infection and the patient’s co-morbidities. Tumor type, type of approach, number of lesions, tumor localization, underlying hepatic disease, the physician’s experience, associated hepatic resection and lesion size have been described as factors significantly associated with complications. The physician in charge should promptly recognize high-risk patients more susceptible to complications, perform a close post procedure follow-up and manage them early and adequately if they occur. We aim to describe complications from RFA of hepatic tumors and their risk factors, as well as a few techniques to avoid them. This way, others can decrease their morbidity rates with better outcomes.

TG13 miscellaneous etiology of cholangitis and cholecystitis

This paper describes typical diseases and morbidities classified in the category of miscellaneous etiology of cholangitis and cholecystitis. The paper also comments on the evidence presented in the Tokyo Guidelines for the management of acute cholangitis and cholecystitis (TG 07) published in 2007 and the evidence reported subsequently, as well as miscellaneous etiology that has not so far been touched on. (1) Oriental cholangitis is the type of cholangitis that occurs following intrahepatic stones and is frequently referred to as an endemic disease in Southeast Asian regions. The characteristics and diagnosis of oriental cholangitis are also commented on. (2) TG 07 recommended percutaneous transhepatic biliary drainage in patients with cholestasis (many of the patients have obstructive jaundice or acute cholangitis and present clinical signs due to hilar biliary stenosis or obstruction). However, the usefulness of endoscopic naso-biliary drainage has increased along with the spread of endoscopic biliary drainage procedures. (3) As for biliary tract infections in patients who underwent biliary tract surgery, the incidence rate of cholangitis after reconstruction of the biliary tract and liver transplantation is presented. (4) As for primary sclerosing cholangitis, the frequency, age of predilection and the rate of combination of inflammatory enteropathy and biliary tract cancer are presented. (5) In the case of acalculous cholecystitis, the frequency of occurrence, causative factors and complications as well as the frequency of gangrenous cholecystitis, gallbladder perforation and diagnostic accuracy are included in the updated Tokyo Guidelines 2013 (TG13). Free full-text articles and a mobile application of TG13 are available via http://www.jshbps.jp/en/guideline/tg13.html.

Flow-dependent vascular heat transfer during microwave thermal ablation

Microwave tumor ablation is an attractive option for thermal ablation because of its inherent benefits over radiofrequency ablation (RFA) in the treatment of solid tumors such as hepatocellular carcinoma (HCC). Microwave energy heats tissue to higher temperatures and at a faster rate than RFA, creating larger, more homogenous ablation zones. In this study, we investigate microwave heating near large vasculature using coupled fluid-flow and thermal analysis. Low-flow conditions are predicted to be more likely to cause cytotoxic heating and, therefore, vessel thrombosis and endothelial damage of downstream tissues. Such conditions may be more prevalent in patient with severe cirrhosis or compromised blood flow. High-flow conditions create the more familiar heat-sink effect that can protect perivascular tissues from the intended thermal damage. These results may help guide placement and use of microwave ablation technologies in future studies.

Effectiveness of impedance monitoring during radiofrequency ablation for predicting popping

AIM: To retrospectively evaluate the effectiveness of impedance monitoring for predicting popping during radiofrequency ablation (RFA) using internally cooled electrodes.

METHODS: We reviewed 140 patients (94 males, 46 females; age range 73.0 ± 11.1 year) who underwent RFA between February 2006 and November 2008 with a modified protocol using a limited power delivery rather than a conventional one to avoid popping. All the patients provided their written informed consent, and the study was approved by the institutional review board. Intraprocedural impedances were measured for the study subjects, and the tumors were classified into three types according to the characteristics of their impedance curves: increasing, flat, or decreasing. The tumors were further sorted into seven subtypes (A-G) depending on the curvature of the impedance curve’s increase or decrease. Relative popping rates were determined for the three types and seven subtypes. A chi-square test was performed to estimate statistical significance.

RESULTS: A total of 148 nodules treated by RFA were analyzed. The study samples included 132 nodules of hepatocellular carcinoma, 14 nodules of metastatic liver cancer, and two nodules of intrahepatic cholangiocarcinoma. The numbers of nodules with each impedance curve type were as follows: 37 increasing-type nodules, 43 flat-type nodules, and 68 decreasing-type nodules. Popping occurrence rates were 24.3%, 46.5% and 64.7%, respectively. Flat-type nodules exhibited a significantly higher rate of popping compared to increasing-type nodules (P = 0.039). Decreasing-type nodules exhibited a significantly higher rate of popping compared to increasing-type nodules (P < 0.0001). Notably, nodules that showed a sharp decrease in impedance in the latter ablation period (subtype E) exhibited a significantly higher rate of popping compared to other subtypes.

CONCLUSION: Intraprocedural impedance monitoring can be a useful tool to predict the occurrence of popping during liver tumor RFA performed with internally cooled electrodes.

Complications of radiofrequency ablation for hepatocellular carcinoma in a multicenter study: An analysis of 16 346 treated nodules in 13 283 patients

AIM

  We surveyed multiple centers to identify types and frequency of complications and mortality rate associated with radiofrequency ablation (RFA) of hepatocellular carcinoma (HCC).

METHODS

  We distributed a questionnaire developed by members of the Chugoku-Shikoku Society for the Local Ablation Therapy of Hepatocellular Carcinoma to 20 centers and analyzed types and frequency of complications and mortality rate.

RESULTS

  In total, 16 346 nodules were treated in 13 283 patients between January 1999 and November 2010. Five patients (0.038%) died: two from intraperitoneal hemorrhage, and one each from hemothorax, severe acute pancreatitis and perforation of the colon. In 16 346 treated nodules, 579 complications (3.54%) were observed, including 78 hemorrhages (0.477%), 276 hepatic injuries (1.69%), 113 extrahepatic organ injuries (0.691%) and 27 tumor progressions (0.17%). The centers that treated a large number of nodules and performed RFA modifications, such as use of artificial ascites, artificial pleural effusion and bile duct cooling, had low complication rates.

CONCLUSION

  This study confirmed that RFA is a low-risk treatment for HCC and that sufficient experience and technical skill can reduce complications.

Determining a minimal safe distance to prevent thermal injury to intrahepatic bile ducts in radiofrequency ablation of the liver: a study in dogs

PURPOSE

To determine a minimal safe distance between the radiofrequency ablation (RFA) electrode tip and major intrahepatic bile ducts to prevent thermal injury during hepatic RFA in a canine model.

MATERIALS AND METHODS

Forty healthy mongrel dogs were randomised equally into four groups based on the distance between the electrode and large intrahepatic bile ducts during RFA of the liver, as follows: 1.0-2.9 mm, 3.0-4.9 mm, 5.0-7.9 mm, or 8.0-10.0 mm. The RFA electrodes were opened uniformly at 2 cm. During RFA, energy was sequentially raised, starting at 5 W and increasing by 5 W increments every minute to a maximum of 95 W. Animals were monitored for a maximum of 14 days post-RFA for complications and by bilirubin testing, after which they were euthanised and their livers were surgically removed for cholangiographic and pathological examination.

RESULTS

When the electrodes were less than 5.0 mm from the bile ducts during RFA, either full or partial-thickness bile duct necrosis occurred, leading to a variety of serious complications. In contrast, when the distance was more than 5.0 mm between the RFA electrode and bile ducts, serious complications occurred rarely, with pathological examinations showing either normal bile ducts or vacuolar changes of the biliary ductal epithelium.

CONCLUSION

A minimum safe distance of 5.0 mm between the RFA electrode and intrahepatic bile ducts was effective in preventing serious complications secondary to bile duct injury in a canine model.

A case of hemocholecyst associated with hemobilia following radiofrequency ablation therapy for hepatocellular carcinoma

Radiofrequency ablation (RFA) is performed as an alternative to surgical resection for primary or secondary liver malignancies. Although RFA can be performed safely in most patients, early and late complications related to mechanical or thermal damage occur in 8-9.5% cases. Hemocholecyst, which refers to hemorrhage of the gallbladder, has been reported with primary gallbladder disease or as a secondary event associated with hemobilia. Hemobilia, defined as hemorrhage in the biliary tract and most commonly associated with accidental or iatrogenic trauma, is a rare complication of RFA. Here we report a case of hemocholecyst associated with hemobilia after RFA for hepatocellular carcinoma that was successfully managed by laparoscopic cholecystectomy.

Mortality and complication rates of percutaneous ablative techniques for the treatment of liver tumors: a systematic review

OBJECTIVES

Reported rates of major complications and mortality of radiofrequency ablation (RFA), microwave ablation (MWA) and percutaneous ethanol injection (PEI) for the treatment of liver tumours were substantially heterogeneous among studies. The aim was to analyse the mortality and major complication rates of percutaneous RFA, PEI and MWA.

METHODS

MEDLINE and EMBASE search from January 1982 to August 2010. Randomised clinical trials and observational studies, age >18, more than 50 patients for each technique analysed, studies reporting mortality and major complications were included. Random effects model was performed, with assessment for heterogeneity and publication bias.

RESULTS

Thirty-four studies including 9531, 1185, and 1442 patients for RFA, MWA, and PEI, respectively were included. For all ablative techniques pooled proportion mortality rate was 0.16% (95% confidence interval [CI], 0.10-0.24). Pooled mortality rate associated with RFA, PEI and MWA was 0.15% (0.08-0.23), 0.59% (0.14-1.3) and 0.23% (0.0-0.58) respectively. Pooled proportion of major complications was 3.29% (2.43-4.28). Major complication rates associated with RFA, MWA, and PEI was 4.1% (3.3-5.1), 4.6% (0.7-11.8) and 2.7% (0.28-7.4) respectively.

CONCLUSIONS

Percutaneous RFA, PEI and MWA can be considered safe techniques for the treatment of liver tumours.

Metformin associated with lower mortality in diabetic patients with early stage hepatocellular carcinoma after radiofrequency ablation

BACKGROUND AND AIM

Type 2 diabetes increases the risk of cancer development and mortality. However, antidiabetic treatment with metformin can reduce the risk of cancer. We studied whether metformin users among diabetic patients with early hepatocellular carcinoma (HCC) undergoing radiofrequency ablation (RFA) would have a favorable survival compared with those without metformin treatment.

METHODS

A total of 135 patients with early stage HCC having 162 tumors underwent RFA. Among them, 53 patients were diabetic, including 21 metformin users and 32 patients without metformin treatment.

RESULTS

Diabetic patients had an inferior survival rate compared with nondiabetic patients (1 year, 82.8% vs 93.9%; 3 years, 55.1% vs 80.2%; 5 years, 41.3% vs 64.7%; P = 0.004). With regards to antidiabetic treatments, metformin users had better survival outcome (adjusted hazard ratio [HR] 0.24; 95% confidence interval [CI], 0.07-0.80; P = 0.020) compared to patients without metformin treatment after adjustments for potential confounders. Sulfonylureas and insulin exposures did not achieve significant conclusions. For the whole studied population including nondiabetic and diabetic patients, the multivariate analysis revealed that maximum tumor size more than 2.5 cm (HR, 3.49; 95% CI, 1.74-6.99; P < 0.001) and diabetic patients without metformin treatment (HR, 3.34; 95% CI, 1.67-6.71, P = 0.001) were independent explanatory variables associated with unfavorable survival.

CONCLUSIONS

Metformin users among diabetic patients with HCC undergoing RFA had a favorable overall survival compared with patients without metformin treatment.

Prophylactic cholecystectomy in midgut carcinoid patients

BACKGROUND

Patients with midgut carcinoid (MGC) tumors are commonly treated with somatostatin analogs. Adverse effects of these drugs include impairment of gallbladder function, formation of gallstones, and cholecystitis. Prophylactic cholecystectomy has been advocated, but data to support this recommendation are sparse. We have analyzed a cohort of 235 patients with MGC focusing on the risk for gallstone formation and complications thereof.

METHODS

Forty-eight of the 235 patients had been cholecystectomized before surgery for MGC. Of the remaining 187 patients, 144 were treated with somatostatin analogs. Eighteen of the 187 patients had their gall bladder removed during the primary carcinoid surgery.

RESULTS

Twenty-two of the 144 somatostatin-analog-treated patients developed complications, such as gallbladder empyema (n = 1), cholangitis (n = 2), acute cholecystitis (n = 6), acute pancreatitis (n = 1) or acute pancreatitis and cholecystitis (n = 1), or biliary colic (n = 11). Ninety-two of the 144 were examined during surgery, by computed tomography, or by ultrasound, most for reasons other than gallbladder-related indications, and 63% (58/92) of these examinations revealed gallstones. Of the 43 patients not treated with somatostatin analogs, only 3 patients suffered from biliary colic and underwent cholecystectomy.

CONCLUSIONS

In our study the incidence of gallstone-related complications seems to be higher than in the general population. We recommend that prophylactic cholecystectomy is liberally performed during laparotomy for MGC if patients are planned to undergo treatment with somatostatin analogs.

Myoglobinuria after laparoscopic radiofrequency ablation of liver tumors

BACKGROUND

There are scant data in the literature about myoglobinuria after radiofrequency ablation (RFA) of liver tumors. The aim of this study is to analyze the incidence and identify the risk factors involved in this complication after RFA.

PATIENTS AND METHODS

An initial case of myoglobinuria and acute kidney injury (AKI) during laparoscopic liver RFA after 10 years of the liver ablation program led to the design of this study. Prospective data were collected on 41 consecutive patients undergoing laparoscopic RFA at our institution over a 9-month period. Urine myoglobin, serum creatinine kinase, and serum creatinine levels were obtained preablation and postablation. Variables were compared between patients to identify possible risk factors that might be related to this rare complication. Data are expressed as mean +/- standard error of the mean.

RESULTS

Two patients were excluded from the study due to preoperative myoglobinuria of unknown etiology. Of the remaining 39 patients, three developed dark urine with significant myoglobinuria on postoperative day 1. Two of these patients had carcinoid liver metastases; the remaining patient had a metastatic colorectal lesion. The number of tumors ablated in these patients was 14, 11, and 3 vs. 2.4 +/- 0.4 in the rest of the patients. Cumulative tumor volume was larger in the group of patients that developed the complication vs. those who did not (127.9 +/- 59.5 vs. 48 +/- 3 cm(3)). Two grounding pads were used in the three patients that had a complication vs. four pads in the rest of the patients. Dark urine was identified promptly intraoperatively and treated aggressively. All of these patients required intensive care unit (ICU) admission and had a prolonged hospital stay. Marked elevation of transaminases and creatinine kinase as well as a drop in hematocrit and platelet count was observed in patients with myoglobinuria. In our retrospective review of 706 patients that underwent liver RFA in the past 10 years, we detected 27 patients (3.8%) with ten or more lesions (11.9 +/- 0.4). None of these patients had significant elevation of serum creatinine postoperatively. In the whole series of 706 patients, 22 (3.2%) were found to have elevated creatinine after liver RFA, with return to baseline in all but seven patients in follow-up.

CONCLUSION

Myoglobinuria after liver RFA is a rare but potentially devastating complication that may lead to AKI with significant morbidity and prolonged hospital stay. Patients with large tumor volumes requiring longer ablation times need to be monitored closely for the development of this complication. The fact that this was not observed in other patients with similar tumor characteristics suggests that individual patient-related factors might play an important role.

Major complications after radiofrequency ablation for liver tumors: Analysis of 255 patients

AIM: To investigate the major complications after radiofrequency ablation (RFA) for the treatment of liver tumors and analyze possible risk factors that precipitate these complications.

METHODS: From March 2001 to April 2008, 255 patients with liver tumors (205 male, 50 female; age range, 18-89 years; mean age, 56.0 years) who received RFA were enrolled in this study. Of these patients, 212 had hepatocellular carcinoma, 39 had metastatic liver tumors and four had cholangiocellular carcinoma. One hundred and forty eight patients had a single tumor, and 107 had multiple tumors. Maximum diameter of the tumors ranged 1.3-20 cm (mean, 5.1 cm). All patients were treated with a cooled-tip perfusion electrode attached to a radiofrequency generator (Radionics, Burlington, MA, USA). RFA was performed via the percutaneous approach (n = 257), laparoscopy (n = 7), or open surgical treatment (n = 86). The major complications related to RFA were recorded. The resultant data were analyzed to determine risk factors associated these complications.

RESULTS: Among the 255 patients, 425 liver tumors were treated and 350 RFA sessions were performed. Thirty-seven (10%) major complications were observed which included 13 cases of liver failure, 10 cases of hydrothorax requiring drainage, three cases of tumor seeding, one case of upper gastrointestinal bleeding, one case of intrahepatic abscess, one case of bile duct injury, one case of cardiac arrest, and five cases of hyperglycemia. Seven patients had more than two complications. Liver failure was the most severe complication and was associated with the highest mortality. Eleven patients died due to worsening liver decompensation. Child-Pugh classification (P = 0.001) and choice of approach (P = 0.045) were related to post-treatment liver failure, whereas patient age, tumor size and number were not significant factors precipitating this complication.

CONCLUSION: RFA can be accepted as a relatively safe procedure for the treatment of liver tumors. However, attention should be paid to possible complications even though the incidences of these complications are rare. Careful patient selection and the best approach choice (percutaneous, laparoscopy, or laparotomy) will help to minimize the incidence and morbidity rate of complications which occur after RFA.

Treatment of ultrasound-guided radiofrequency ablation for primary hepatic carcinoma: an analysis of 46 cases

AIM: To compare and analyze the therapeutic efficacy of ultrasound-guided radiofrequency ablation (RFA) for the primary hepatic carcinoma.

METHODS: A total of 46 patients with 69 nodules of the primary hepatic carcinoma were treated at our hospital from March 2003 to July 2008. All patients were clinically diagnosed, treated with RFA and followed up. Patients' survival rates were analyzed using Kaplan-Meier model and Log-rank test, the complete ablation rate and the local recurrence rate were calculated using χ2 test.

RESULTS: After RFA treatment, the complete ablation rate, the local recurrence rate, the 1-, 2-, and 3-year survival rates were 93.61%, 6.82%, 87.10%, 80.13%, 61.92% respectively in the patients with the nodule < 3 cm, and were 68.18%, 27.27 %, 73.33%, 53.33%, 30.48% respectively in the patients with the nodule ≥ 3 cm; the complete ablation rate, the local recurrence rate, the 1- , 2-, and 3-year survival rates were 90.00%, 10.00%, 90.00%, 82.80% and 63.98% for the patients with the single nodule and were 82.05%, 15.38%, 68.75 %, 50.00 % and 28.57% respectively for those with multiple nodules; the complete ablation rate, the local recurrence rate, the 1- , 2-, and 3-year survival rates, were 87.93%, 13.21%, 86.40%, 75.25% and 54.99% respectively for the patients in Child-Pugh classification A, and 81.82%, 22.22%, 66.67%, 53.33%, 35.56 respectively for those in Child-Pugh classification B and C.

CONCLUSION: The complete ablation rate and the local recurrence rate of RFA treatment on PHC are related to the size of the nodules; the long-term survival rate is related to the number, size of the nodules and liver function.