Percutaneous microwave ablation of hepatic tumors: prospective evaluation of postablation syndrome and postprocedural pain

Sex-Differences in Post-Procedural Pain Experiences After Thermal Liver Ablations for Liver Tumors: A Retrospective Study

INTRODUCTION

Literature shows differences in pain experiences between sexes. The exact influence of thermal liver ablation on experienced pain is still not well-known. This study aims to investigate the maximum pain intensity at the recovery between men and women after percutaneous thermal liver ablation.

METHODS

Patients treated with percutaneous thermal liver ablation (radiofrequency or microwave ablation) in Maastricht University Medical Center + between 2018 and 2022 for primary or secondary liver tumors were included retrospectively. Outcomes included maximum numerical rating scale (NRS, scale:0-10) score at the recovery room, prevalence of post-procedural pain (defined as NRS score ≥ 4), duration of anesthesia, length of stay at recovery, and complications. Regression analyses were adjusted for age, ASA-score, BMI, tumor type, maximum diameter of lesion, chronic pain in patients' history, and history of psychological disorder.

RESULTS

183 patients were included of which 123 men (67%). Results showed higher average maximum NRS scores in women patients compared to men (mean:3.88 versus 2.73), but not after adjustments (aß:0.75, 95%CI:-0.13-1.64). Women suffered more from acute post-procedural pain (59% versus 35%; aOR:2.50, 95%CI:1.16-5.39), and needed analgesics more often at the recovery room (aOR:2.43, 95%CI:1.07-5.48) compared to men. NRS score at recovery arrival did not significantly differ (aß:0.37, 95%CI:-0.48-1.22). No differences were seen in the length of stay at the recovery, duration of anesthesia, procedure time, and complication rate. Location of the tumor (subcapsular or deep), total tumors per patient, and distinction between primary and secondary tumors had no influence on the NRS.

CONCLUSION

This retrospective single-center study shows higher post-procedural pain rates after thermal liver ablation in women, resulting in higher analgesics use at the recovery room. The results suggest considering higher dosage of analgesics during thermal liver ablation in women to reduce post-procedural pain. LEVEL OF EVIDENCE 3: Non-controlled retrospective cohort study.

Efficacy of percutaneous microwave ablation guided by contrast-enhanced and two-dimensional ultrasound for in hepatic alveolar echinococcosis in difficult/dangerous locations

Background

Ultrasound-guided microwave ablation (MWA) has become a popular method for treating malignant liver tumors. However, few studies have investigated its use in the treatment of hepatoalveolar echinococcosis (HAE). This study aimed to explore the effectiveness and safety of contrast-enhanced ultrasound combined with two-dimensional ultrasound-guided MWA for the treatment of HAE in difficult/dangerous locations.

Methods

Data from 81 patients, who were diagnosed with hepatic alveolar hydatid disease in difficult/dangerous locations between January 2018 and January 2023, and underwent contrast-enhanced ultrasonography combined with two-dimensional ultrasound-guided MWA, were analyzed. After undergoing MWA, patients were followed up to determine whether the lesions recurred and to evaluate the therapeutic effect of MWA. Preoperatively, individualized strategies were designed for lesions in different locations, and different auxiliary ablation technologies were used for contrast-enhanced ultrasound combined with two-dimensional ultrasound-guided MWA to achieve complete inactivation of lesions in difficult/dangerous locations.

Results

MWA was performed on 89 HAE lesions in 81 patients. The median diameter of the lesions was 2.86 cm (interquartile range [IQR] 2.36-3.49 cm). The complete ablation rate after surgery was 100%, with a recurrence rate of 11.11%, and median follow-up of 24 months (IQR 12-48 months). The incidence of minor complications was 14.81%; no serious complications or deaths occurred. Compared with before surgery, TB, DB, alanine aminotransferase, and aspartate aminotransferase levels increased (p < 0.001), albumin platelets and activated partial thromboplastin time decreased (p < 0.05), with no statistical difference in prothrombin time (p > 0.05).

Conclusion

MWA may be a safe and effective method for treating HAE in difficult/dangerous locations, and may represent a new and alternative option for this patient population.

Outpatient percutaneous image-guided microwave ablation with monitored anesthesia care: An exploratory study

PURPOSE

To evaluate the feasibility, safety, and periprocedural perception of pain for a combination approach of moderate and deep sedation for image-guided percutaneous microwave ablation of both primary and secondary malignant lesions.

METHODS

This was a retrospective study of 33 image-guided percutaneous microwave ablation procedures performed on 33 patients in an outpatient-based interventional radiology center. We used a combination of midazolam, fentanyl, propofol, and/or ketamine to achieve mild to moderate sedation for the procedure, and also to achieve deeper sedation as needed for the ablation portion.

RESULTS

Technical success was achieved in all image-guided percutaneous microwave ablation procedures. Mean procedural time was 49.4 min. There were no major complications. Intraprocedural pain was absent in all patients. All 33 patients were deemed fit for discharge within 30 min following the procedure.

CONCLUSION

The combination approach of moderate and deep sedation for anesthesia during image-guided percutaneous microwave ablation is an advantageous option. This approach has a strong safety profile, good technical success, short procedure times, low levels of intraprocedural and post-procedural pain, and short recovery from anesthesia.

Evaluation of paravertebral blocks in improving post-procedural pain and decreasing hospital admission after microwave ablation of liver tumors

Although ablations are performed with conscious sedation or general anesthesia, microwave ablations can be painful post procedure. Newer analgesic modalities, including regional blocks, have promoted the proliferation of less invasive anesthesia care for ablative procedures. This study evaluates whether bilateral paravertebral blocks reduce the need for additional analgesics in comparison to unilateral blocks in microwave ablations. In this retrospective study, individuals undergoing microwave ablation who underwent unilateral versus bilateral nerve blocks at a single institution from 2017 to 2019 were compared. Categorical variables were analyzed using Pearson's chi-squared tests. Comparisons of means were completed using multiple T-tests corrected using the Holm-Sidak method with α = 0.05. Regression modeling was used to identify factors related to increased MME (milligram morphine equivalent) usage and post-procedure admission rates. A total of 106 patients undergoing 112 liver MWA procedures were included in this analysis, with patients receiving either a bilateral or unilateral block. Pre-procedural characteristics demonstrated no significant differences in age or gender. Bilateral blocks were associated with decreased usage of gabapentin (14% vs. 0%, p = 0.01) and a lower rate of post-procedure admissions (OR 0.23, p = 0.003). Therefore, when using paravertebral blocks, bilateral blocks are superior to unilateral blocks, as demonstrated by decreased rates of hospital admission and reduced use of systemic neuropathic pain medication. Additionally, reducing post-procedural MME may reduce the rate of admission to the hospital.

Hepatic Hilar Nerve Block for Adjunctive Analgesia during Percutaneous Thermal Ablation of Hepatic Tumors: A Retrospective Analysis

PURPOSE

To determine whether hepatic hilar nerve block techniques reduce analgesic and sedation requirements during percutaneous image-guided thermal ablation of hepatic tumors.

MATERIALS AND METHODS

A single-center retrospective cohort analysis was performed of 177 patients (median age, 67 years; range, 33-86 years) who underwent percutaneous image-guided thermal ablation of liver tumors. All patients were treated utilizing local anesthetic and moderate sedation between November 2018 and November 2021 at a tertiary level hospital, with or without the administration of a hepatic hilar nerve block. Univariable and multivariable linear regression analyses were performed to determine the relationship between the administration of the hilar nerve block and fentanyl and midazolam dosages.

RESULTS

A total of 114 (64%) patients received a hilar nerve block in addition to procedural sedation, and 63 (36%) patients received procedural sedation alone. There were no significant differences in the baseline demographic and tumor characteristics between the cohorts. The procedure duration was longer in the hilar block cohort than in the unblocked cohort (median, 95 vs 82 minutes; P = .0012). The technical success rate (98% in both the cohorts, P = .93) and adverse event rate (11% vs 3%, P = .14) were not significantly different between the cohorts. After adjusting for patient and tumor characteristics, ablation modality, and procedure and ablation durations, hilar nerve blocks were associated with lower fentanyl (-18.4%, P = .0045) and midazolam (-22.7%, P = .0007) dosages.

CONCLUSIONS

Hepatic hilar nerve blocks significantly decrease the fentanyl and midazolam requirements during thermal ablation of hepatic tumors, without a significant change in the technical success or adverse event rates.

Percutaneous ultrasound-guided microwave ablation for treatment of hepatocellular carcinomas in dogs: four cases (2019-2020)

OBJECTIVES

To describe ultrasound-guided microwave ablation as a minimally invasive treatment option for primary or metastatic hepatocellular carcinomas.

METHODS

Four client-owned dogs underwent percutaneous ultrasound-guided microwave ablation of three primary and one metastatic hepatocellular carcinoma, diagnosed on cytology/histopathology. In each case, multiple ultrasound-guided thermal lesions were created in a 10 to 40 minutes ablation at 30 to 35 W. Real-time monitoring was performed using 10 MHz diagnostic ultrasound transducers. The procedures were performed without complication and CT scans or abdominal ultrasounds were repeated immediately after. Patients were discharged on oral analgesia on the same day or 24 hours later.

RESULTS

Hepatocellular carcinomas were successfully ablated, which in some cases resulted in an improvement in clinical signs and laboratory values. The patients were followed up for a time ranging between 39 and 649 days and no evidence of disease progression was found. Three out of four patients are still alive at the time of writing.

CLINICAL SIGNIFICANCE

In these four patients, minimally invasive ultrasound-guided microwave ablation was feasible and resulted in no immediate complications. Regular imaging follow-up is recommended after the procedure and further studies on microwave ablation are warranted to establish its effectiveness in dogs with hepatocellular carcinomas.

Optimizing anxiolysis and analgesia for percutaneous intervention by the abdominal radiologist

Abdominal radiologists perform a wide variety of image-guided interventions. Procedures performed by abdominal radiologists can be broadly categorized into paracentesis, thoracentesis, superficial and deep soft tissue biopsy, drain placement, and ablation. As these procedures continue to develop as an alternative to more invasive and potentially morbid interventions, and with continued improvements in minimally invasive technologies, it becomes increasingly important for abdominal radiologists to be familiar with options for peri-procedural analgesia and anxiolysis, as well as when to consult anesthesiology. In this review, we discuss analgesic, anxiolytic, and nonpharmacologic options available to the abdominal radiologist. We focus on practical agents that are relatively safe for general use, special populations, and considerations for post-procedural monitoring.

Oncologic Interventions: Periprocedural Medications

Significant advances in ablative and endovascular therapies have allowed interventional radiology to play a substantial role in the management of patients with malignant neoplasms. The evolution of these procedures and the optimization of patient outcomes and experience must take into account various elements of the periprocedural period. Some of the most important considerations within the periprocedural period are the pharmacologic agents used to avoid infectious complications, decrease pain, and manage side effects. In this article, we discuss some of the most commonly used medications in interventional oncology procedures including antibiotics, narcotics, sedatives, antiemetics, and others.

Pain after Interventional Radiology in Oncology: A Case-Control Study from a 5-Year Cohort

Background: Interventional radiology plays a major role in oncology both for curative and palliative treatment, but few reports address post-procedural pain. The purpose of this study was to quantify postoperative pain after interventional radiology procedures in oncology and to identify major pain-associated pre and intraoperative factors. Methods: From 2015 to 2019, all patients treated with interventional radiology were included retrospectively in a cohort study. Anesthetic protocols were standardized by the type of radiological procedure. Demographic data, preoperative treatments, analgesic agents, pain score levels, and morphine consumption from the post-anesthesia care unit (PACU) to hospital discharge were collected from databases. In an additional case-control study, patients reporting strong or intolerable pain in PACU were compared to those with no pain. Matching to control cases was based on the type of intervention, sex, and age. Results: From 4411 procedures, severe pain in PACU was more frequent in women (p < 0.04) and the youngest patients (p < 0.0001), after general anesthesia (p < 0.0001). Higher pain levels were associated with certain procedures, such as arterial embolization, limb cementoplasty, osteosynthesis, and abdominal tumor ablation, and when the intervention duration exceeded 160 min (p = 0.038). In the cohort study, high-dose remifentanil (≥0.055 µg/kg/min) was a risk factor for post-procedural high pain levels (p < 0.001). Intraoperative ketoprofen was associated with a decrease in high pain level incidence (p < 0.0001). Severe pain in PACU was a risk factor for severe pain in wards from day 0 until discharge. Conclusion: Severe pain depends on the type and duration of interventional radiology, type of anesthesia, and preoperative use of opiates. Limiting doses of remifentanil and injecting intraoperative analgesics, especially ketoprofen, may reduce the incidence of post-intervention severe pain.

Effectiveness and safety of ultrasound-guided percutaneous microwave ablation for hepatic alveolar echinococcosis

Background

Microwave ablation (MWA) is a popular therapy for liver malignant tumor in recent years. Few studies have been conducted on its use in the treatment of hepatic alveolar echinococcosis (HAE). The study aims to evaluate the efficacy and safety of MWA in the treatment of HAE.

Methods

This study analyzed the data of 45 patients (mean age, 38 ± 2 years; 24 males) diagnosed with HAE and underwent MWA treatment between June 2014 to December 2019. The patients after MWA were examined by CT or MRI [follow-up: 32 months (IQR 23–48.5)] to determine whether the lesions were relapsed and to evaluate the therapeutic effect of MWA. The safety of MWA was evaluated by monitoring postoperative complications. Clinical data, such as patient demographics, imaging features of the lesions, relevant findings of laboratory tests before and after ablation, and information related to ablation, were collected and analyzed. Paired-sample t tests and paired-sample Wilcoxon signed-rank tests were used to compare relevant laboratory indicators before and after MWA.

Results

MWA was applied to 57 HAE lesions in 45 patients. The median size of lesions was 3.42 cm (IQR2.85–4.41). The rate of complete ablation was 100% (57/57). The median follow-up time was 32 months (IQR 23–48.5). The recurrence rate was 13% (6/45), and the median time of recurrence was 22 months. The rate of minor complications was 11.1% (5/45), and there were no major complications and deaths. Compared to preoperative, ALB, RBC, HBG, and PLT were decreased (p < 0.001); ALT, TB, DB, and WBC were increased (p < 0.001); and no statistically difference in PT, APTT, and INR (p > 0.05).

Conclusions

MWA might be a safe and effective way to cure HAE. Meanwhile, it provides a new option and a new way of thinking about treatment for patients with HAE.

Continuous versus pulsed microwave ablation in the liver: any difference in intraoperative pain scores?

Background

This study prospectively compared intraoperative pain scores during percutaneous microwave ablation of the liver in patients randomized between continuous and pulsed energy delivery algorithms.

Methods

During a 12-month period, 20 patients who underwent microwave liver ablation were prospectively randomized between 2 different energy delivery modes: “continuous mode” (CM, n=10) and “pulsed mode” (PM, n=10). All ablation sessions were performed using the same microwave ablation platform under computed tomographic guidance and intravenous analgesia. Within 30 min post ablation, all patients completed a questionnaire assigning a numeric pain intensity score from 0 (no pain) to 10.

Results

Mean pain scores were 8.17±1.850 in the CM group and 4.50±1.567 in the PM group, with a statistically significant difference of 3.667±2.807 pain units (P=0.001). The mean procedure time was 53.5±20.90 min in the PM group vs. 58.5±17.44 min in the CM group (P=0.279). The mean size of the lesions was 2.81±0.95 cm in the PM group and 2.81±0.85 cm in the CM group (P=0.984). On a per-lesion basis, technical success was achieved in all evaluable tumors in both groups. No difference was noted in the local tumor control on the 6-month imaging evaluation. No complications were observed in the CM arm, while small perihepatic hemorrhagic fluid collections were reported in the PM group.

Conclusions

Both algorithms for microwave energy delivery have comparable treatment effects in terms of 6-month local tumor control for liver lesions <3 cm in diameter. PM treatments compared to CM appear to induce significantly less pain in patients undergoing percutaneous liver ablation under intravenous analgesia.

Value of MRI/CT Image Fusion for Targeting "invisible" Lesions in Stereotactic Microwave Ablation (SMWA) of Malignant Liver Lesions: A Retrospective Analysis

PURPOSE

To assess the technical feasibility of MRI/CT image fusion and completeness of ablation treatment for primary or metastatic liver lesions invisible on contrast-enhanced CT planning scans and outcome in patients treated with stereotactic microwave ablation (SMWA).

MATERIALS AND METHODS

The study was approved by the local ethics committee. Patients who underwent SMWA between January 2015 and December 2018 were retrospectively analyzed. All liver lesions for which MRI/CT fusion was performed due to invisibility on pre-interventional CT planning scans were included and reassessed. The outcome measurement was successful ablation of the lesion at first follow-up imaging.

RESULTS

During the study period, 236 patients underwent 312 SMWAs with ablation of 496 lesions. Twenty-four lesions in 15 patients (mean age, 62 years; range, 43-80 years) were included. Following MRI/CT image fusion, all 24 lesions could be sufficiently localized to perform SMWA. The first follow-up imaging showed complete ablation of 22 lesions. Two initially incompletely ablated lesions were hepatocellular carcinomas and were successfully re-ablated afterwards.

CONCLUSION

SMWA with MRI/CT image fusion is an accurate and safe treatment option for patients with liver lesions not detectable on contrast-enhanced CT planning scans. MRI/CT image fusion may allow more patients with malignant liver lesions to benefit from local ablation treatment even if their lesions are not visible on CT planning examinations.

Microwave ablation of liver cancer: An updated review

The treatment methods for early liver cancer include surgical resection, liver transplantation, and local ablation. Among them, microwave ablation (MWA) is widely used in clinical practice because of its outstanding advantages, such as minimal invasiveness, radical curative effect, short treatment time, few complications, and no heat-sink effect, especially for the treatment of tumors adjacent to major vessels and hepatic metastases. However, MWA also has limitations such as unpredictable size and shape of the ablation area. This review systematically illustrates the effectiveness and safety of MWA in the treatment of liver cancer. Meanwhile, the relative superiority of the new generation of MWA is discussed, with an aim to provide reference for MWA of liver cancer.

Transcatheter arterial chemoembolization combined with simultaneous DynaCT-guided microwave ablation in the treatment of small hepatocellular carcinoma

PURPOSE

To evaluate the method and effectiveness of transcatheter arterial chemoembolization (TACE) combined with simultaneous DynaCT-guided Microwave ablation (MWA) for the treatment of small hepatocellular carcinoma (SHCC).

MATERIALS AND METHODS

From June 2015 to May 2017, a total of 28 consecutive patients with SHCC received single treatment of TACE and 23 subjects received a combination treatment of TACE with simultaneous DynaCT-guided MWA. Following 1 month of treatment, the tumor response was assessed using the mRECIST criteria and the outcomes were analyzed including intervention-associated complications, changes in liver function, imaging response, and progression-free survival (PFS).

RESULTS

The technical success rate was 100%. The rates of CR (65%) in the combined TACE and MWA group were higher than those of the TACE group (46%). The rate of common adverse events, such as liver abscess, spontaneous bacterial peritonitis and liver dysfunction, in the combined TACE and MWA group (56%) was comparable to the corresponding rate of the TACE group (P > 0.411). The median and mean PFS of the TACE group were significantly lower than those of the combined TACE and MWA group (19.00 months vs. 29.00 months, 21.076 months vs. 24.693 months, p = 0.019, log-rank test).

CONCLUSION

Stereotactic DynaCT-guided MWA is a safe and effective method for the treatment of SHCC, which usually provides an effective tumor puncture path, notably for lesions that cannot be detected following TACE. Overall, the data suggested that this treatment method could improve the clinical outcome of patients with SHCC.

Efficacy and Safety of Percutaneous Argon-Helium Cryoablation for Hepatocellular Carcinoma Abutting the Diaphragm

PURPOSE

To evaluate the efficacy and safety of percutaneous argon-helium cryoablation (CA) for hepatocellular carcinoma (HCC) abutting the diaphragm (<5 mm).

MATERIALS AND METHODS

A total of 61 consecutive patients (50 men, 11 women; mean age, 56.3 ± 12.1 years old; range, 32-83 years) with 74 HCC tumors (mean size, 3.3 ± 1.7 cm; range, 0.8-7 cm) who were treated with percutaneous argon-helium CA were enrolled in this retrospective study. Adverse events were evaluated according to Common Terminology Criteria for Adverse Events, version 5.0. Local tumor progression (LTP) and overall survival (OS) were analyzed using the Kaplan-Meier method and the log-rank test. The risk factors associated with OS and LTP were evaluated using univariate and multivariate Cox regression analysis.

RESULTS

No periprocedural (30-day) deaths occurred. A total of 29 intrathoracic adverse events occurred in 24 of the 61 patients. Major adverse events were reported in 5 patients (pleural effusion requiring catheter drainage in 4 patients and pneumothorax requiring catheter placement in 1 patient). Median follow-up was 18.7 months (range, 2.3-60.0 months). Median time to LTP after CA was 20.9 months (interquartile range [IQR], 14.1-30.6 months). Median times of OS after CA and diagnosis were 27.3 months (IQR, 15.1-45.1 months) and 40.9 months (interquartile range, 24.8-68.6 months), respectively. Independent prognostic factors for OS included tumor location (left lobe vs right lobe; hazard ratio [HR], 2.031; 95% confidence interval [CI], 1.062-3.885; P = .032) and number of intrahepatic tumors (solitary vs multifocal; HR, 2.684; 95% CI, 1.322-5.447; P = .006). Independent prognostic factors for LTP included age (HR, 0.931; 95% CI, 0.900-0.963; P  < .001), guidance modality (ultrasound vs computed tomography and US; HR, 6.156 95% CI, 1.862-20.348; P  =   .003) and origin of liver disease.

CONCLUSIONS

Percutaneous argon-helium CA is safe for the treatment of HCC abutting the diaphragm, with acceptable LTP and OS.

Percutaneous image-guided ablation: From techniques to treatments

Image-guided ablation is performed by percutaneously introducing ablation probes to deliver energy into a tumor to destroy it in a controlled and localized fashion. Ablation modalities can be broadly classified as thermal or non-thermal based on the mechanism of tumor destruction and are performed using different types of image guidance for planning, delivering and follow-up of the treatment. Ablation is performed in a minimally invasive fashion, providing greater residual organ preservation with minimal morbidity to the patient. Image-guided ablation is being used in the clinic for the treatment of primary and metastatic tumors, and this article reviews state of the art for the treatment of malignancies in the liver, lung, kidney and musculoskeletal tissue.

Propofol Compared to Midazolam Sedation and to General Anesthesia for Percutaneous Microwave Ablation in Patients with Hepatic Malignancies: A Single-Center Comparative Analysis of Three Historical Cohorts

Purpose

In percutaneous ablation procedures, periprocedural pain, unrest and respiratory concerns can be detrimental to achieve a safe and efficacious ablation and impair treatment outcome. This study aimed to compare the association between anesthetic technique and local disease control in patients undergoing percutaneous microwave ablation (MWA) of colorectal liver metastases (CRLM) and hepatocellular carcinoma (HCC).

Materials and Methods

This IRB-exempted single-center comparative, retrospective analysis of three cohorts analyzed 90 patients treated for hepatic malignancies from January 2013 until September 2018. The local tumor progression-free survival (LTPFS), safety and periprocedural pain perception were assessed using univariate and multivariate Cox proportional hazard regression analyses to correct for potential confounders.

Results

In 114 procedures (22 general anesthesia; 32 midazolam; 60 propofol), 171 liver tumors (136 CRLM; 35 HCC) were treated with percutaneous MWA. Propofol and general anesthesia were superior to midazolam/fentanyl sedation regarding LTPFS (4/94 [4.3%] vs. 19/42 [45.2%] vs. 2/35 [5.7%]; P < 0.001, respectively). Local tumor progression rate was 14.6% (25/171). Eighteen tumors (72.0%) were retreated by ablation. Of them, 14 (78%) were previously treated with midazolam. Propofol versus midazolam (P < 0.001), general anesthesia versus midazolam (P = 0.016), direct postprocedural visual analog pain score above 5 (P = 0.050) and more than one tumor per procedure (P = 0.045) were predictors for LTPFS. Multivariate analysis revealed that propofol versus midazolam (HR 7.94 [95% CI 0.04–0.39; P < 0.001]) and general anesthesia versus midazolam (HR 6.33 [95% CI 0.04–0.69; P = 0.014]) were associated with LTPFS. Pain during and directly after treatment was significantly worse in patients who received midazolam sedation (P < 0.001).

Conclusions

Compared to propofol and general anesthesia, midazolam/fentanyl sedation was associated with an increased periprocedural perception of pain and lower local tumor progression-free survival. To reduce the number of repeat procedures required to eradicate hepatic malignancies, general anesthesia and propofol sedation should be favored over midazolam.

Similar complication rates for irreversible electroporation and thermal ablation in patients with hepatocellular tumors

Background To compare the frequency of adverse events of thermal microwave (MWA) and radiofrequency ablation (RFA) with non-thermal irreversible electroporation (IRE) in percutaneous ablation of hepatocellular carcinoma (HCC). Patients and methods We retrospectively analyzed 117 MWA/RFA and 47 IRE procedures (one tumor treated per procedure; 144 men and 20 women; median age, 66 years) regarding adverse events, duration of hospital and intensive care unit (ICU) stays and occurrence of a post-ablation syndrome. Complications were classified according to the Clavien & Dindo classification system. Results 70.1% of the RFA/MWA and 63.8% of the IRE procedures were performed without complications. Grade I and II complications (any deviation from the normal postinterventional course, e.g., analgesics) occurred in 26.5% (31/117) of MWA/RFA and 34.0% (16/47) of IRE procedures. Grade III and IV (major) complications occurred in 2.6% (3/117) of MWA/RFA and 2.1% (1/47) of IRE procedures. There was no significant difference in the frequency of complications (p = 0.864), duration of hospital and ICU stay and the occurrence of a post-ablation syndrome between the two groups. Conclusions Our results suggest that thermal (MWA and RFA) and non-thermal IRE ablation of malignant liver tumors have comparable complication rates despite the higher number of punctures and the lack of track cauterization in IRE.

Pain control for patients with hepatocellular carcinoma undergoing CT-guided percutaneous microwave ablation

Background

Hepatic percutaneous microwave ablation (MWA) is usually performed in patients under conscious sedation. Nonetheless, many patients reported pain during the procedure. The current study investigated the safety and effectiveness of analgesia given at personalized dosage during the MWA procedure.

Methods

A total of 100 patients with hepatocellular carcinomas (HCCs) were included in this study. These patients underwent CT-guided percutaneous MWA between February and October 2017. Patients were randomized into two groups: Experimental group (n = 50) and Control group (n = 50). Patients in the Control group were given 5 mg of morphine intravenously, followed by 10 mg of morphine injected subcutaneously 30 min before surgery. Patients in the Experimental group were given a personalized dosage of morphine during the procedure when the Visual Analogue Scale (VAS) was ≥4. Other clinical and treatment parameters were also analysed.

Results

A significantly less amount of morphine (p < 0.001) was used in the experimental group (7.18 ± 1.65 mg) than in the control group (17.40 ± 2.52 mg). No significant differences were found in the number of patients who needed to discontinue the surgery (p = 0.242). Other clinical parameters including heart rate, systolic and diastolic blood pressures at various time points were comparable. Importantly, a lower VAS was reported in the experimental group, indicating a lower pain intensity experienced by patients during the procedure.

Conclusion

The administration of personalized dosage of morphine to HCC patients undergoing percutaneous MWA is an effective and safe procedure for pain control.

The Safety and Efficacy of Oxycodone Versus Fentanyl in Percutaneous Microwave Ablation of a Liver Tumour Abutting the Capsule

PURPOSE

The present study compared the safety and efficacy of oxycodone with those of fentanyl under non-intubated general anaesthesia in percutaneous microwave ablation (MWA) of a liver tumour abutting the capsule.

MATERIALS AND METHODS

Thirty-eight patients underwent MWA of liver cancers abutting the capsule. Patients received 0.1 mg/kg oxycodone (O group) or 1 μg/kg fentanyl (F group) prior to the start of ablation. Both groups received continuous infusions of propofol for non-intubated general anaesthesia during ablation. The primary outcomes were the pain scores (11-point numeric rating scale, NRS) within 24 h after MWA. Vital signs, body movement during ablation, and opioid side effects after ablation were recorded. The need for additional analgesics was recorded 24 h after MWA.

RESULTS

The pain NRS scores were lower in the O group than in the F group at 0.5 (P = 0.035), 3 (P = 0.002), and 6 h (P = 0.001) after MWA, and fewer patients required additional analgesics in the O group (6 of 20 vs. 13 of 18, P = 0.022) within 24 h. The average 24-h dose of dezocine was 5.5 ± 4.1 mg in the F group and 2.1 ± 3.3 mg in the O group (P = 0.008). A significant reduction in the respiratory rate (P = 0.020) and more body movements were observed in the F group (P = 0.027) during ablation with non-intubated general anaesthesia. No differences in post-operative nausea and vomiting (PONV) were observed between the two groups, but dizziness occurred significantly more often in the O group (P = 0.033). No significant differences in other vital signs were observed before, during, and after the procedure.

CONCLUSIONS

Oxycodone provides better analgesia and reduces post-operative opioid consumption without significant respiratory or hemodynamic instability.

The management of peri- and postprocedural pain in interventional radiology: a narrative review

Interventional radiology encompasses a wide range of procedures and the degree of associated pain depends predominantly on the procedure being undertaken. Procedures may be painful during but not after the procedure, relatively painless during but painful after the procedure, or relatively painless during and after the procedure. However, there is a lack of good quality publications in interventional radiology that specifically address the subject of peri- and postprocedural pain management. Nevertheless, a variety of more or less complex protocols exist for intraprocedural sedation and for peri- and postprocedural analgesia. While weight-based protocols for procedural sedation have demonstrable benefit, protocols for postprocedural pain relief after major procedures have not been sufficiently rigorously evaluated.

Local Ablation for Solid Tumor Liver Metastases: Techniques and Treatment Efficacy

BACKGROUND

Treatment options for liver metastases from solid tumors, such as colon cancer, breast cancer, neuroendocrine tumors, and sarcomas, have expanded in recent years and now include nonresection methods.

METHODS

The literature focused on the treatment of liver metastases was reviewed for technique, perioperative, and long-term outcomes specifically related to local ablation techniques for liver metastases.

RESULTS

Ablation modalities have become popular as therapies for patients who are not appropriate candidates for surgical resection. Use of these techniques, alone or in combination with other liver-directed therapies (and often systemic therapy), has extended the rate of survival for patients with liver metastases and, at times, offers nearly equivalent disease-free survival rates to surgical resection.

CONCLUSIONS

Although surgical resection remains the optimal treatment for liver metastasis, local options, including microwave ablation and radiofrequency ablation, can offer similar long-term local control in appropriately selected patients.

Microwave ablation in primary and secondary liver tumours: technical and clinical approaches

Thermal ablation is increasingly being utilised in the treatment of primary and metastatic liver tumours, both as curative therapy and as a bridge to transplantation. Recent advances in high-powered microwave ablation systems have allowed physicians to realise the theoretical heating advantages of microwave energy compared to other ablation modalities. As a result there is a growing body of literature detailing the effects of microwave energy on tissue heating, as well as its effect on clinical outcomes. This article will discuss the relevant physics, review current clinical outcomes and then describe the current techniques used to optimise patient care when using microwave ablation systems.

Irreversible Electroporation versus Radiofrequency Ablation: A Comparison of Local and Systemic Effects in a Small-Animal Model

Purpose To compare both periablational and systemic effects of two mechanistically different types of ablation: thermal radiofrequency (RF) ablation and electroporative ablation with irreversible electroporation (IRE) in appropriately selected animal models. Materials and Methods Animal experiments were performed according to a protocol approved by the Animal Care Committee of Hebrew University. Female C57BL/6 mice (n = 165) were randomized to undergo either RF or IRE ablation of noncancerous normal liver. The inflammatory response, cell proliferation, interleukin 6 (IL-6) levels, and intactness of vessels in the liver were assessed at 6, 12, and 24 hours and at 3, 7, and 14 days after ablation (n = 122 for mechanistic experiments). Systemic effects were then assessed by comparing tumor formation in an Mdr2-knockout (KO) mouse model (n = 15) and tumor growth in a remote BNL 1ME hepatoma xenograft tumor (n = 28). Results were averaged and evaluated by using two-tailed t tests. Results Although RF ablation was associated with a well-defined periablational inflammatory rim, for IRE, the infiltrate penetrated the ablation zone, largely along persistently patent vessels. Peak IL-6 levels (6 hours after ablation) were 10 and three times higher than at baseline for IRE and RF, respectively (P < .03). Mdr2-KO mice that were treated with IRE ablation had more tumors that were 3 mm or larger than mice treated with RF ablation or sham operation (mean, 3.6 ± 1.3 [standard deviation] vs 2.4 ± 1.1 and 2.2 ± 0.8, respectively; P < .05 for IRE vs both RF ablation and sham operation). For BNL 1ME tumors, both RF and IRE liver ablation reduced tumor growth, with a greater effect noted for IRE (1329 mm(3) ± 586 and 819 mm(3) ± 327 vs 2241 mm(3) ± 548 for sham operation; P < .05) that was accompanied by more infiltrating lymphocytes compared with sham operation (7.6 cells per frame ± 1.9 vs 11.2 ± 2.1 vs 0.3 ± 0.1; P < .05). Conclusion Persistent patency of vasculature within the coagulated zone from IRE increases the area and accumulation of infiltrative cells that is associated with a higher serum IL-6 level than RF ablation. These local changes of IRE induce more robust systemic effects, including both tumorigenic and immunogenic effects. (©) RSNA, 2016 Online supplemental material is available for this article.

Value of microwave ablation in treatment of large lesions of hepatocellular carcinoma

OBJECTIVE

Thermal ablative therapies continue to be favored as a safe and effective treatment for patients with non-resectable hepatocellular carcinoma (HCC). Percutaneous microwave ablative therapy, which is a relatively new technique, has the advantage in providing faster ablation of large tumors. This study aimed to evaluate microwave ablation in the treatment of large HCC (5-7 cm) and to assess its effect on local tumor progression, prognostic outcome and patients' survival.

METHODS

In all, 26 patients with large HCC lesions (5-7 cm) were managed in the multidisciplinary clinic of Kasr Al Ainy University hospital using microwave ablation. The treatment was performed with the patient under conscious sedation and analgesia and ultrasonography-guided using an HS AMICA microwave machine operating at frequency of 2450 MHz and a power up to 100 W. Multiple needle insertions were made in one or two sessions according to the size of the lesion. The complete ablation rate, local tumor progression and patients' overall survival were analyzed, and the efficacy and safety of MWA was evaluated.

RESULTS

Complete ablation was achieved in 19/26 (73.1%). Local tumor progression was recorded in five treated lesions (19.2%). Distant tumor progression within the liver was recorded in six patients (23.1%), with a mean survival of 21.5 months. No procedure-related major complications or deaths were observed.

CONCLUSIONS

Percutaneous microwave ablation is safe and effective in the treatment of large HCC tumors. Patients' survival and local tumor control were acceptable.

Microwave Ablation: Comparison of Simultaneous and Sequential Activation of Multiple Antennas in Liver Model Systems

PURPOSE

To compare microwave ablation zones created by using sequential or simultaneous power delivery in ex vivo and in vivo liver tissue.

MATERIALS AND METHODS

All procedures were approved by the institutional animal care and use committee. Microwave ablations were performed in both ex vivo and in vivo liver models with a 2.45-GHz system capable of powering up to three antennas simultaneously. Two- and three-antenna arrays were evaluated in each model. Sequential and simultaneous ablations were created by delivering power (50 W ex vivo, 65 W in vivo) for 5 minutes per antenna (10 and 15 minutes total ablation time for sequential ablations, 5 minutes for simultaneous ablations). Thirty-two ablations were performed in ex vivo bovine livers (eight per group) and 28 in the livers of eight swine in vivo (seven per group). Ablation zone size and circularity metrics were determined from ablations excised postmortem. Mixed effects modeling was used to evaluate the influence of power delivery, number of antennas, and tissue type.

RESULTS

On average, ablations created by using the simultaneous power delivery technique were larger than those with the sequential technique (P < .05). Simultaneous ablations were also more circular than sequential ablations (P = .0001). Larger and more circular ablations were achieved with three antennas compared with two antennas (P < .05). Ablations were generally smaller in vivo compared with ex vivo.

CONCLUSION

The use of multiple antennas and simultaneous power delivery creates larger, more confluent ablations with greater temperatures than those created with sequential power delivery.

Hepatocellular carcinoma: Surgeon's view on latest findings and future perspectives

Hepatocellular carcinoma (HCC) is the most common liver-derived malignancy with a high fatality rate. Risk factors for the development of HCC have been identified and are clearly described. However, due to the lack of tumor-specific symptoms, HCC are diagnosed at progressed tumor stages in most patients, and thus curative therapeutic options are limited. The focus of this review is on surgical therapeutic options which can be offered to patients with HCC with special regard to recent findings, not exclusively focused on surgical therapy, but also to other treatment modalities. Further, potential promising future perspectives for the treatment of HCC are discussed.

Artificial Ascites for Pain Relief During Microwave Ablation of Subcapsular Liver Tumors

PURPOSE

To compare post-procedure pain of subcapsular hepatic metastasis treated with microwave ablation (MWA) with and without artificial ascites.

MATERIALS AND METHODS

During a 2-years period, 41 patients underwent MWA of 52 peripheral liver metastases including 20 patients (10 men and 10 women (mean ± SD age: 62 ± 9.3 years) who underwent MWA of 27 metastasis without artificial ascites (group 1), and 21 patients (12 men and 9 women (mean age: 63.5 ± 9.9 years) who underwent MWA of 25 metastasis with artificial ascites (group 2). Patient's pain assessment cores [10-point visual analog scale (VAS)] at 6, 24 h, and 4 days after the MWA procedure were compared among groups, as well as 24 h cumulative morphine dose was also compared among groups. Complications were reported. Statistical significance was evaluated by Fisher's exact test and Student's t test.

RESULTS

Pain VAS were 8.6 ± 2.7, 3.9 ± 1.4, and 0.6 ± 1.2 at 6, 24 h, 4 days, respectively, for group-I and 0.8 ± 1.9, 0.3 ± 0.9, and 6.6 ± 3.5 for group II. Pain VAS were significantly different at 6, 24 h, and 4 days between the two groups (p < 0.0001). The average 24 h dose of morphine was 5.8 ± 2.2 mg in group-I and 0.2 ± 0.6 mg in group-II (p < 0.0001). Complications occurred in two patients from group-I (10%), including one bilio-pleural fistula and one minor cutaneous burn. One patient (9.5%) in group-II developed a lobar infarction. No bleeding and no procedure-related death were reported.

CONCLUSION

Artificial ascites prevents immediate post-procedural pain, which re-appears intensively 4 days later.

Complications of image-guided thermal ablation of liver and kidney neoplasms

Image-guided thermal ablation is a widely accepted tool in the treatment of a variety of solid organ neoplasms. Among the different techniques of ablation, radiofrequency ablation, cryoablation, and microwave ablation have been most commonly used and investigated in the treatment of liver and kidney neoplasms. This article will review complications following thermal ablation of tumors in the liver and kidney, and discuss the risks and clinical presentation of each complication as well as how to treat and potentially avoid complications.