Anesthesia for Percutaneous Radiofrequency Tumor Ablation (PRFA): A Review of Current Practice and Techniques

Current insights into anaesthesia and critical care management of patients with hepatocellular carcinoma: Multifaceted implications for the anaesthesiologist and intensive care physician

BACKGROUND

The incidence of hepatocellular carcinoma (HCC) is on the rise worldwide, due to the increasing prevalence of liver diseases associated with metabolic dysfunction and better management of cirrhosis and its complications. The diversification of HCC treatments has recently increased, with the choice of strategy based on HCC characteristics, liver function and comorbidities. The combination of new therapies has transformed the prognosis, with up to 70% survival at 5 years.

OBJECTIVE

The aim of this review was to analyse the most recent data on preoperative evaluation, peri-operative anaesthetic management of liver resection, liver transplantation and other types of procedures, and to highlight the multidisciplinary aspect of such management.

MAIN FINDINGS AND DISCUSSION

The importance of preanaesthetic evaluation will depend largely on the procedure proposed, associated co-morbidities and the stage of liver disease. This assessment should verify stabilisation of all comorbidities, and evaluate the degree of portal hypertension, cirrhosis severity and sarcopenia. Liver resection and liver transplantation for HCC present specific surgical challenges, and minimally invasive techniques improve recovery. Nonsurgical procedures considered as therapeutic (ablation) or standby (regional embolisation) are diverse, and all expose patients to specific intra-anaesthetic complications, sometimes requiring intensive care management. Peri-operative anaesthetic strategies deployed in the management of liver resection or nonsurgical procedures involve specific management of fluids, coagulation, narcosis and analgesia, which can impact on patients' overall, and cancer prognosis. Lastly, new down-staging strategies combining several types of procedure and possibly immunotherapy, also call for collegial reflection on posthepatic transplant immunosuppression, which must remain tailored to each individual patient.

Cone Beam CT Derived Laser-Guided Percutaneous Lung Ablation: Minimizing Needle-Related Complications Under General Anesthesia with Lung Separation

RATIONALE AND OBJECTIVES

Percutaneous lung tumor ablations are mostly performed in computed tomography (CT) rooms under local anesthesia with conscious sedation. However, maintaining the breath-hold phase during this can be challenging, affecting image quality and increasing complications. With the advent of hybrid operating rooms (HORs), this procedure can be performed with endotracheal tube (ETGA) intubation under general anesthesia with lung separation, ensuring precise imaging in a single-stage setting. Lung separation provides surgical exposure of one lung while ensuring ample gas exchange with the other. This study evaluated tumor ablations performed in an HOR equipped with cone beam CT and laser guidance.

MATERIALS AND METHODS

This retrospective study included patients who underwent lung tumor ablation under general anesthesia with an ETGA in an HOR between July 2020 and May 2023. Anesthesia considerations, perioperative management, and postoperative follow-ups were evaluated.

RESULTS

65 patients (78 tumors) underwent ablation using two types of lung ventilation methods including a single-lumen tube with a blocker (SLT/BL) (n = 15) and double-lumen tube (DLT) (n = 50). Most patients experienced desaturation during the apnea phase of dynamic CT and needling. The average SpO2 value was significantly lower in the DLT group than in the SLT/BL group during the procedure (81.1% versus 88.7%, P = 0.033). Five, three, and two patients developed pneumothorax, subcutaneous emphysema, and pleural effusion, respectively.

CONCLUSION

Percutaneous ablation under general anesthesia with endotracheal intubation and lung separation performed in HORs was feasible and safe. The setup minimized complication risks and maintained a balance between patient safety and successful procedures.

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.

Non-Operating Room Anesthesia (NORA) for Ultrasound-Guided Liver Radiofrequency Ablation

INTRODUCTION

Percutaneous ultrasound-guided radiofrequency ablation (RFA) is a well-studied treatment option for locally non-advanced hepatocellular carcinoma (HCC) and colorectal liver metastases (CRLMs). Sedation is of crucial interest as it enables safe and pain-free procedures. Whether the type of sedation has an impact on procedural outcome is still not well investigated.

METHODS

We retrospectively collected data on patients undergoing liver RFA for various oncological conditions. Procedures were conducted in a non-operating room anesthesia (NORA) setting. Procedural-related complications and short-term oncological outcomes were analyzed.

RESULTS

Thirty-five patients (mean age 71.5 y, 80% male) were treated for HCC (26), CRLM (6) and gastric cancer metastases (3). Mean lesion size was 21 mm (SD ± 10.1 mm), and the most common tumor localization was the right hepatic lobe. RFA was performed in a step-up sedation approach, with subcutaneous lidocaine injection prior to needle placement and subsequent deep sedation during ablation. No anesthesia-related early or late complications occurred. One patient presented with pleural effusion due to a large ablation zone and was treated conservatively. Local tumor-free survival after 1 and 6 months was 100% in all cases where a curative RFA approach was intended.

CONCLUSIONS

NORA for liver RFA comes with high patient acceptance and tolerance, and optimal postoperative outcomes and oncologic results.

Tissue Ablation: Applications and Perspectives

Tissue ablation techniques have emerged as a critical component of modern medical practice and biomedical research, offering versatile solutions for treating various diseases and disorders. Percutaneous ablation is minimally invasive and offers numerous advantages over traditional surgery, such as shorter recovery times, reduced hospital stays, and decreased healthcare costs. Intra-procedural imaging during ablation also allows precise visualization of the treated tissue while minimizing injury to the surrounding normal tissues, reducing the risk of complications. Here, the mechanisms of tissue ablation and innovative energy delivery systems are explored, highlighting recent advancements that have reshaped the landscape of clinical practice. Current clinical challenges related to tissue ablation are also discussed, underlining unmet clinical needs for more advanced material-based approaches to improve the delivery of energy and pharmacology-based therapeutics.

Treatment strategies for malignant pulmonary nodule: beyond lobectomy. Point-counterpoint

PURPOSE OF REVIEW

Technological advancement in low-dose computed tomography resulted in an increased incidental discovery of early-stage lung cancer and multifocal ground glass opacity. The demand for parenchyma-preserving treatment strategies is greater now than ever. Pulmonary ablative therapy is a groundbreaking technique to offer local ablative treatment in a lung-sparing manner. It has become a promising technique in lung cancer management with its diverse applicability. In this article, we will review the current development of ablative therapy in lung and look into the future of this innovative technique.

RECENT FINDINGS

Current literature suggests that ablative therapy offers comparable local disease control to other local therapies and stereotactic body radiation therapy (SBRT), with a low risk of complications. In particular, bronchoscopic microwave ablation (BMWA) has considerably fewer pleural-based complications due to the avoidance of pleural puncture. BMWA can be considered in the multidisciplinary treatment pathway as it allows re-ablation and allows SBRT after BMWA.

SUMMARY

With the benefits which ablative therapy offers and its ability to incorporate into the multidisciplinary management pathway, we foresee ablative therapy, especially BMWA gaining significance in lung cancer treatment. Future directions on developing novel automated navigation platforms and the latest form of ablative energy would further enhance clinical outcomes for our patients.

A comparative study of esketamine-dexmedetomidine and sufentanil-dexmedetomidine for sedation and analgesia in lung tumor percutaneous radiofrequency ablation (PRFA): a randomized double-blind clinical trial

OBJECTIVE

To observe and evaluate the effectiveness and safety of Esketamine or Sufentanil combined with Dexmedetomidine for sedation and analgesia in lung tumor percutaneous radiofrequency ablation (PRFA) to provide a clinical basis for the optimization of sedation and analgesia in lung tumor PRFA protocols outside the operating room.

METHODS

In this trial, 44 patients aged 37 to 84 undergoing lung tumor PRFA were enrolled and assigned to Group E (n = 22, Esketamine 0.2 mg/kg) or Group S (n = 22,Sufentanil 0.1 μg/kg ). Dexmedetomidine was infused intravenously as a sedative in both groups. The modified observer's assessment of alertness and sedation scale (MOAAS), physical movement pain scale, intraoperative vital signs, anesthesia recovery time, radiologist and patient satisfaction rates, incidence of respiratory depression, and incidence of postoperative nausea and vomiting were recorded.

RESULTS

Although there was no significant difference in the physical movement pain scale, blood oxygen saturation or incidence of perioperative adverse events between the two groups during ablation, the MOAAS, mean arterial pressure (MAP) and heart rate (HR) were higher in Group E than in Group S. The anesthesia recovery time was shorter in Group E than in Group S, and radiologist satisfaction was better in Group E than in Group S, but there was no significant difference between the two groups in terms of patient satisfaction.

CONCLUSION

Esketamine or Sufentanil combined with Dexmedetomidine is safe for lung tumor PRFA. However, in elderly patients with multiple underlying diseases, low-dose Esketamine combined with Dexmedetomidine has fewer hemodynamic effects on patients, milder respiratory depression, shorter recovery time, and better radiologist satisfaction because of its better controllability of sedation depth.

TRIAL REGISTRATION

Chinese Clinical Trial Registry (Registration number#ChiCTR ChiCTR21000500 21); Date of Registration: 16/08/2021.

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.

Radiofrequency Ablation, Cryoablation, and Microwave Ablation for the Treatment of Small Renal Masses: Efficacy and Complications

Over the last two decades the detection rate of small renal masses has increased, due to improving diagnostic accuracy, and nephron-sparing treatments have become the first-choice curative option for small renal masses. As a minimally invasive alternative, thermal ablation has increased in popularity, offering a good clinical outcome and low recurrence rate. Radiofrequency ablation, Cryoablation, and Microwave ablation are the main ablative techniques. All of them are mostly overlapping in term of cancer specific free survival and outcomes. These techniques require imaging study to assess lesions features and to plan the procedure: US, CT, and both of them together are the leading guidance alternatives. Imaging findings guide the interventional radiologist in assessing the risk of complication and possible residual disease after procedure. The purpose of this review is to compare different ablative modalities and different imaging guides, underlining the effectiveness, outcomes, and complications related to each of them, in order to assist the interventional radiologist in choosing the best option for the patient.

Different effects of intravenous and local anesthesia in patients undergoing ultrasound-guided radiofrequency ablation of thyroid nodules: a prospective cohort study

PURPOSE

To compare the efficacy and safety of intravenous anesthesia (IV) with local anesthesia (LA) in patients undergoing ultrasound (US)-guided radiofrequency ablation (RFA) of thyroid nodules.

METHODS

50 patients with American Society of Anesthesiologists classification grades I-II undergoing US-guided thyroid RFA were enrolled and randomly (1:1) divided into IV (conscious sedation with Ramsay Sedation Scale [RSS] scores of 2-3 with an anesthesiologist) and LA (subcutaneous anesthesia with lidocaine without an anesthesiologist) groups. Pre-, intra- and post-procedural blood pressure (BP) (SBP₀/DBP₀, SBP₁/DBP₁, and SBP₂/DBP₂), intra- and post-procedural pain (NRS₁ and NRS₂), ablated area volume, treatment time and adverse events were analyzed and compared.

RESULTS

Age, sex, weight, number, nature, volume of nodules, and SBP₀/DBP₀ showed no difference between both groups. 11 and 0 patients' SBP₁/DBP₁ were elevated in the LA and IV groups. NRS₁ differed between both groups. 6 patients in the LA group had moderate or severe pain, but none in the IV group. No between-group difference in SBP₂/DBP₂, NRS₂, ablation completion rate and ablated volume was noted. The median procedure duration differed from 1109 (176) s in IV group and 723 (227) s in LA groups. There was no increased incidence of adverse events in IV group.

CONCLUSIONS

IV with RSS scores of 2-3 maintained intra-procedural BP and relieved intra-procedural pain better, without affecting the ablation efficacy and increasing complications. Despite increased treatment time, IV is a potential option for patients undergoing US-guided RFA of thyroid nodules.

An ultrasonically actuated needle promotes the transport of nanoparticles and fluids

Non-invasive therapeutic ultrasound (US) methods, such as high-intensity focused ultrasound (HIFU), have limited access to tissue targets shadowed by bones or presence of gas. This study demonstrates that an ultrasonically actuated medical needle can be used to translate nanoparticles and fluids under the action of nonlinear phenomena, potentially overcoming some limitations of HIFU. A simulation study was first conducted to study the delivery of a tracer with an ultrasonically actuated needle (33 kHz) inside a porous medium acting as a model for soft tissue. The model was then validated experimentally in different concentrations of agarose gel showing a close match with the experimental results, when diluted soot nanoparticles (diameter < 150 nm) were employed as delivered entity. An additional simulation study demonstrated a threefold increase in the volume covered by the delivered agent in liver under a constant injection rate, when compared to without US. This method, if developed to its full potential, could serve as a cost effective way to improve safety and efficacy of drug therapies by maximizing the concentration of delivered entities within, e.g., a small lesion, while minimizing exposure outside the lesion.

Ablation techniques in non-small cell lung cancer patients: experience of a single center

BACKGROUND

Percutaneous radiofrequency ablation (RFA) and microwave ablation (MWA) are well-established treatments for patients with non-small cell lung cancer (NSCLC). This study assessed the efficacy and safety of RFA and MWA performed on NSCLC patients.

MATERIAL AND METHODS

This retrospective study included one hundred twenty-four patients with NSCLC who underwent percutaneous ablation from November 2014 to November 2020 in the Department of Medical Imaging and Interventional Radiology of Sotiria General Hospital for Chest Diseases in Athens, Greece. Forty (stage IA) were treated with RFA, while 84 were treated with MWA (stages IA, IB, and IIA). All procedures were performed using the AMICA GEN radiofrequency and microwave generator. As a follow-up method, computed tomography was performed immediately after the procedure to evaluate the lesion's response and complications and one, three, six, and twelve months after the ablation.

RESULTS

All ablations were technically successful. The first-month follow-up revealed stage IIA residual tumors in eight patients. Local recurrence was detected one year after RFA in two of the 40 patients and thirteen of the 84 patients after MWA. Overall survival (OS) rates at one, two, and three years for stage IA NSCLC patients treated with ablation were 94 %, 73 %, 57 % for RFA, and 96 %, 75 %, and 62 % for MWA, respectively. In contrast, the OS for stages IB and IIA patients treated with MWA was 90 %, 66 %, and 51 % for the IB stage and 82 %, 62 %, and 48 % for the IIA stage, respectively. Fifteen percent of patients after RFA and 9.5 % after MWA experienced minor complications. Pneumothorax was documented in three patients after RFA and four after MWA. Post-ablation syndrome occurred in 15 % of RFA patients and 8.3 % of MWA patients. There were no major complications.

CONCLUSION

RFA and MWA have comparable efficacy and safety for patients in stage IA. MWA is an effective alternative treatment option for non-resectable IB or IIA stages NSCLC patients. HIPPOKRATIA 2022, 26 (3):105-109.

An ultrasonically actuated fine-needle creates cavitation in bovine liver

Ultrasonic cavitation is being used in medical applications as a way to influence matter, such as tissue or drug vehicles, on a micro-scale. Oscillating or collapsing cavitation bubbles provide transient mechanical force fields, which can, e.g., fractionate soft tissue or even disintegrate solid objects, such as calculi. Our recent study demonstrates that an ultrasonically actuated medical needle can create cavitation phenomena inside water. However, the presence and behavior of cavitation and related bioeffects in diagnostic and therapeutic applications with ultrasonically actuated needles are not known. Using simulations, we demonstrate numerically and experimentally the cavitation phenomena near ultrasonically actuated needles. We define the cavitation onset within a liver tissue model with different total acoustic power levels. We directly visualize and quantitatively characterize cavitation events generated by the ultrasonic needle in thin fresh bovine liver sections enabled by high-speed imaging. On a qualitative basis, the numerical and experimental results show a close resemblance in threshold and spatial distribution of cavitation. These findings are crucial for developing new methods and technologies employing ultrasonically actuated fine needles, such as ultrasound-enhanced fine-needle biopsy, drug delivery, and histotripsy.

Contemporary evidence on colorectal liver metastases ablation: toward a paradigm shift in locoregional treatment

Image-guided percutaneous ablation techniques represent an attractive local therapy for the treatment of colorectal liver metastases (CLM) given its low risk of severe complications, which allows for early initiation of adjuvant therapies and spare functional liver parenchyma, allowing repeated treatments at the time of recurrence. However, ablation does not consistently achieve similar oncological outcomes to surgery, with the latter being currently considered the first-line local treatment modality in international guidelines. Recent application of computer-assisted ablation planning, guidance, and intra-procedural response assessment has improved percutaneous ablation outcomes. In addition, the evolving understanding of tumor molecular profiling has brought to light several biological factors associated with oncological outcomes following local therapies. The standardization of ablation procedures, the understanding of previously unknown biological factors affecting ablation outcomes, and the evidence by ongoing prospective clinical trials are poised to change the current perspective and indications on the use of ablation for CLM.

The Incidence of Bacteremia and Risk Factors of Post-Radiofrequency Ablation Fever for Patients with Hepato-Cellular Carcinoma

Post-radiofrequency ablation (RFA) fever is a self-limited complication of RFA. The correlation between post-RFA fever and bacteremia and the risk factors associated with post-RFA fever have not been evaluated. Patients with newly diagnosed or recurrent hepatocellular carcinoma who underwent ultrasonography-guided RFA between April 2014 and February 2019 were retrospectively enrolled. Post-RFA fever was defined as any episode of body temperature >38.0 °C after RFA during hospitalization. A total of 272 patients were enrolled, and there were 452 applications of RFA. The frequency of post-RFA fever was 18.4% (83/452), and 65.1% (54/83) of post-RFA fevers occurred on the first day after ablation. Patients with post-RFA fever had a longer hospital stay than those without (9.06 days vs. 5.50 days, p < 0.001). Only four (4.8%) patients with post-RFA fever had bacteremia. The independent factors associated with post-RFA fever were younger age (adjusted odds ratio (OR) = 0.96, 95% CI, 0.94-0.99, p = 0.019), low serum albumin level (adjusted OR = 0.49, 95% CI, 0.25-0.95, p = 0.036), general anesthesia (adjusted OR = 2.06, 95% CI, 1.15-3.69, p = 0.015), tumor size (adjusted OR = 1.52, 95% CI, 1.04-2.02, p = 0.032), and tumor number (adjusted OR = 1.71, 95% CI, 1.20-2.45, p = 0.003).

Ultrasound-Guided Moving Shot Radiofrequency Ablation of Benign Soft Tissue Neoplasm

Background and Objective: To evaluate the effectiveness of radiofrequency ablation (RFA) using the moving-shot technique for benign soft tissue neoplasm. Materials and Methods: This retrospective study reviewed eight patients with benign soft tissue neoplasm presenting with cosmetic concerns and/or symptomatic issues who refused surgery. Six patients had vascular malformation, including four with venous malformation and two with congenital hemangioma. The other two patients had neurofibroma. All patients underwent RFA using the moving-shot technique. Imaging and clinical follow-up were performed in all patients. Follow-up image modalities included ultrasound (US), computed tomography (CT), and magnetic resonance (MR) imaging. The volume reduction ratio (VRR), cosmetic scale (CS), and complications were evaluated. Results: Among the seven patients having received single-stage RFA, there were significant volume reductions between baseline (33.3 ± 21.2 cm³), midterm follow-up (5.1 ± 3.8 cm³, p = 0.020), and final follow-up (3.6 ± 1.4 cm³, p = 0.022) volumes. The VRR was 84.5 ± 9.2% at final follow-up. There were also significant improvements in the CS (from 3.71 to 1.57, p = 0.017). The remaining patient, in the process of a scheduled two-stage RFA, had a 33.8% VRR after the first RFA. The overall VRR among the eight patients was 77.5%. No complications or re-growth of the targeted lesions were noted during the follow-up period. Of the eight patients, two received RFA under local anesthesia, while the other six patients were under general anesthesia. Conclusions: RFA using the moving-shot technique is an effective, safe, and minimally invasive treatment for benign soft tissue neoplasms, achieving mass volume reduction within 6 months and significant esthetic improvement, either with local anesthesia or with general anesthesia under certain conditions.

Image-Guided Ablation for Colorectal Liver Metastasis: Principles, Current Evidence, and the Path Forward

Image-guided ablation can provide effective local tumor control in selected patients with CLM. A randomized controlled trial suggested that radiofrequency ablation combined with systemic chemotherapy resulted in a survival benefit for patients with unresectable CLM, compared to systemic chemotherapy alone. For small tumors, ablation with adequate margins can be considered as an alternative to resection. The improvement of ablation technologies can allow the treatment of tumors close to major vascular structures or bile ducts, on which the applicability of thermal ablation modalities is challenging. Several factors affect the outcomes of ablation, including but not limited to tumor size, number, location, minimal ablation margin, RAS mutation status, prior hepatectomy, and extrahepatic disease. Further understanding of the impact of tumor biology and advanced imaging guidance on overall patient outcomes might help to tailor its application, and improve outcomes of image-guided ablation.

Percutaneous ablation versus surgical ablation and resection of liver tumors: medicare volume and physician reimbursement trends from 2010 to 2018

PURPOSE

The purpose of this study is to analyze trends in Medicare volume and physician reimbursement for percutaneous ablation, surgical ablation, and resection of liver tumors from 2010 to 2018.

METHODS

Claims from the Medicare Part B PSPSMF for the years 2010 to 2018 were extracted using the CPT codes for percutaneous and surgical ablation of liver tumors and surgical liver resection. Total procedural volume and physician payment were analyzed by procedure and physician specialty.

RESULTS

From 2010 to 2018, the volume of percutaneous ablation of liver tumors increased 94.3% from 1630 to 3168 procedures, and the volume of surgical ablations increased 86.2% from 593 to 1104 procedures. In contrast, there was a 16.8% decrease in liver resections from 10,807 to 8994 procedures. Physician reimbursement for percutaneous ablation decreased from $702.41 to $610.11 (- 13.1%). Conversely, reimbursement for resection increased from $849.18 to $1015.06 (19.5%). Reimbursement for surgical ablation also increased from $722.36 to $744.25 (3.0%). In 2018, physician reimbursement for resection and surgical ablation were 66% and 22% more than that for percutaneous ablation.

CONCLUSION

An increasing number of patients with liver tumors were treated with percutaneous ablation from 2010 to 2018. Despite higher morbidity, a dwindling set of theoretical advantages over percutaneous ablation, and higher overall costs, the volume of surgical ablation also increased over this time period. The findings of this study suggest that a reevaluation of practice and referral patterns for surgical ablation of liver tumors is warranted in many institutions.

Comparison of deep and moderate neuromuscular blockade in microwave ablation of liver tumours: a randomized-controlled clinical trial

Microwave ablation (MWA) is gaining popularity for the treatment of small primary hepatocellular carcinoma and metastatic lesions especially if patients are not candidates for surgical resection. Deep neuromuscular blockade (DMB) is perceived to improve surgical working conditions compared to moderate neuromuscular blockade (MMB) but no studies have examined the same benefits in MWA of liver tumours. This study aimed to compare the clinical outcomes of DMB and MMB in MWA of liver tumours in terms of liver excursion, performance scores by the interventional radiologists and patients, requirements of additional muscle relaxants and complications. 50 patients were recruited and 45 patients (22 in MMB group, 23 in DMB group) completed the study. The mean liver excursion for the MMB group (1.42 ± 1.83 mm) was significantly higher than the DMB group (0.26 ± 0.38 mm) (p = 0.001). The mean Leiden-Surgical Rating Scale (L-SRS) rated by the two interventional radiologists were 4.5 ± 0.59 and 3.6 ± 0.85 for the DMB and MMB groups, respectively (p = 0.01). There was also statistically significant difference on patient satisfaction scores (0–10: Extremely Dissatisfied–Extremely Satisfied) between DMB (8.74 ± 1.1) and MMB (7.86 ± 1.25) groups (p = 0.01). 5 patients from MMB group and none from DMB group required bolus relaxant during the MWA procedure. Adverse events were also noted to be more severe in the MMB group. In conclusion, DMB significantly reduced liver excursion and movement leading to improved accuracy, safety and success in ablating liver tumour.

Sedation and Analgesia for Liver Cancer Percutaneous Radiofrequency Ablation: Fentanyl and Oxycodone Comparison

Background: Sedation and analgesia use in percutaneous radiofrequency ablation (RFPA) for liver cancer is a necessary part of the procedure; however, the optimal medicine for sedation and analgesia for PRFA remains controversial. The aim of this study was to compare the perioperative pain management, haemodynamic stability and side effects between oxycodone (OXY) and fentanyl (FEN) use in patients under dexmedetomidine sedation. Methods: Two hundred and five adults with an American Society of Anaesthesiologists physical status score of I to II were included in this study. Patients were assigned to the OXY (n=101) or FEN (n=104) group. Radiofrequency ablation was performed under spontaneous breathing and with painless anaesthesia administered intravenously. The outcomes included fluctuations in mean arterial pressure, heart rate, side effects and the perioperative numerical rating scale (NRS). Results: Radiofrequency ablation was successfully performed in 205 patients. No significant differences were observed in mean blood pressure fluctuations between the two groups despite the longer durations of ablation and total sedation time in the OXY group. The highest NRS score during the surgery and 1 hour and 2 hours after the surgery were significantly lower in the OXY group than in the FEN group. Heart rate fluctuations were significantly lower in the OXY group than in FEN group throughout the surgery. More patients in the FEN group displayed unwanted body movement and respiratory depression. Conclusions: Both oxycodone and fentanyl can be applied for liver cancer percutaneous radiofrequency ablation; however, oxycodone provides a better patient experience, lower postoperative pain, less respiratory depression and stable haemodynamic fluctuations.

The Ablation of Thyroid Nodule's Afferent Arteries Before Radiofrequency Ablation: Preliminary Data

Induced radiofrequency thermal ablation is the cytoreductive treatment of symptomatic benign thyroid nodules, metastatic and recurrent thyroid tumors and papillary thyroid microcarcinomas. It is a safe and effective alternative to surgery and it allows to obtain satisfactory results in terms of volumetric reduction of the nodule with significant improvement in the quality of life. The trans-isthmic approach and the moving shot technique are the two basic techniques; however, an advanced technique, artery-first feeding radiofrequency ablation, has been developed and validated. We have prospectively included 29 consecutive patients who have undergone radiofrequency ablation (Group A) or artery- first vRFA (Group B). All included patients had a diagnosis of benign nodular goiter and they underwent a single session of radiofrequency ablation. All patients followed a follow-up program at 1 month, 3 months, and 6 months. Continuous variables (age, TSH value, basal volume of nodule, used Joule, time in second of the procedure, nodules' volume at 1-, 3-, and 6- months of follow-up and percentage of volume reduction at 1-, 3-, and 6- months of follow-up) were described as mean, standard deviation and range, while categorical variables (gender, nodule structure and nodule vascularization) were described as number of cases and percentage. Independent samples t-test were performed to compare the continuous variables. A Test of Proportions was applied to the categorical variables. The Fisher's exact test was used to analyze the gender. Statistical significance was considered in case of p-value <0.05. Solid structure and spongiform structure showed statistic differences with p-values of 0.022 and 0.023 respectively between two groups. The percentage of reduction at 1 month did not show a significant difference between two groups; instead, the percentage of volume reduction was decreased mostly in the Group B at 3 months and 6 months of follow-up with a p-value of 0.003 and 0.013, respectively. The Joules/energy used showed a statistically significant difference (p-value=0.05), more energy must be used in vascular radiofrequency ablation. These data allow us to hypothesize that vRFA may improve the effectiveness of the procedure, allowing for a reduction in volume more quickly. They were preliminary but promising results, clearly a larger series of cases and prolonged follow-up are needed to clarify and confirm our observations.