Microwave versus radiofrequency ablation for the treatment of liver malignancies: a randomized controlled phase 2 trial

[EN] Microwave (MWA) and radiofrequency ablation (RFA) are main ablative techniques for hepatocellular carcinoma (HCC) and colorectal liver metastasis (MT). This randomized phase 2 clinical trial compares the effectiveness of MWA and RFA as well as morphology of corresponding ablation zones. HCC and MT patients with 1.5-4 cm tumors, suitable for ablation, were randomized into MWA or RFA Groups. The primary endpoint was short-to-long diameter ratio of ablation zone (SLR). Primary technical success (TS) and a cumulative local tumor progression (LTP) after a median 2-year follow-up were compared. Between June 2015 and April 2020, 82 patients were randomly assigned (41 patients per group). For the per-protocol analysis, five patients were excluded. MWA created larger ablation zones than RFA (p = 0.036) although without differences in SLR (0.5 for both groups, p = 0.229). The TS was achieved in 98% (46/47) and 90% (45/50) (p = 0.108), and LTP was observed in 21% (10/47) vs. 12% (6/50) (OR 1.9 [95% CI 0.66-5.3], p = 0.238) of tumors in MWA vs. RFA Group, respectively. Major complications were found in 5 cases (11%) vs. 2 cases (4%), without statistical significance. MWA and RFA show similar SLR, effectiveness and safety in liver tumors between 1.5 and 4 cm.This work was supported by a grant for medical research from Spanish Government (FIS-PI12/00799) and by the Spanish Ministerio de Ciencia, Innovacion y Universidades under "Programa Estatal de I+D+i Orientada a los Retos de la Sociedad", Grant RTI2018-094357-B-C21.Radosevic, A.; Quesada, R.; Serlavos, C.; Sánchez, J.; Zugazaga, A.; Sierra, A.; Coll, S.... (2022). Microwave versus radiofrequency ablation for the treatment of liver malignancies: a randomized controlled phase 2 trial. Scientific Reports. 12(1):1-10. https://doi.org/10.1038/s41598-021-03802-xS11012

Metastatic gallbladder adenocarcinoma with signet-ring cells: A case report

<p>Abstract</p> <p>Introduction</p> <p>Signet-ring cell carcinoma is a rare and aggressive variant of mucinous adenocarcinoma. Only a few cases of gallbladder adenocarcinoma with signet-ring cells have been reported and because of this there is a lack of knowledge about the behavior and biology of this pathology.</p> <p>Case presentation</p> <p>We present the case of a 63-year-old Arab man with gallbladder signet-ring cell adenocarcinoma. He had an elective cholecystectomy and refused chemotherapy. Two months later, a small hepatic metastatic nodule was found, and nine months later he presented with multiple metastases in the liver, lymphatic nodes, both pleuras, peritoneum and subcutaneous tissue.</p> <p>Conclusion</p> <p>The proliferation of signet-ring cells in a gallbladder adenocarcinoma worsens the prognosis of an already adverse neoplasm. New lines of treatment in chemotherapy, such as cisplatin, or new biological therapy, such as monoclonal antibody c-myc oncogene, should be encouraged to improve the survival and life quality of these oncologic patients.</p

Clinical efficacy and safety of a new hybrid radiofrequency electrode for treatment of liver malignancies : Phase I and phase II randomized clinical trial using radiofrequency versus microwave ablation

La ablación con radiofrecuencia y microondas son opciones terapéuticas útiles para el tratamiento de tumores malignos hepáticos en pacientes seleccionados. Aunque comparables, sus resultados son todavía inferiores a los obtenidos con cirugía. Se han intentado crear dispositivos capaces de producir ablaciones mayores y con geometrías más favorables. Uno de estos dispositivos es Gnomon, el electrodo híbrido experimental desarrollado por nuestro equipo cuya validación clínica en las fases I y II del ensayo clínico constituye el objeto de esta tesis. Inicialmente confirmamos que este electrodo es seguro para el uso clínico y posteriormente, a través de un estudio randomizado, hemos comparado este electrodo con el sistema de microondas de última generación. Aunque no hemos encontrado mejoría en cuanto a geometría de la zona de ablación, los resultados técnicos y clínicos parecen que están en a la altura de los resultados obtenidos con uno de los sistemas de microondas de última generación.Radiofrequency ablation and MWA have each been reported as offering a useful therapeutic option for the treatment of liver malignancy in selected patients. Although comparable, their results are still inferior to results obtained through surgical resection. Efforts have been made to develop devices that are able to produce larger ablation zones with a more favorable geometry. One of these devices is Gnomon, an experimental hybrid electrode developed by our team whose clinical testing through Phase I and Phase II trials is the object of this thesis. We have initially confirmed that this electrode is safe for clinical use and posteriorly, through a randomized clinical trial, we compared this electrode with the latest generation microwave system. Although we did not confirm improvement of the ablation zone geometry, the technical and clinical outcomes seem to be in the range of those obtained with one of the latest generation of microwave systems

The next Pandora’s Box of criminal background checks

The use of criminal background checks (CBCs) – requests for information on previous convictions during the employment recruitment process – is growing worldwide. This article seeks to explain the proliferation in CBCs by examining whether novel legislation introducing mandatory requests for some jobs also leads to an increase in requests for CBCs for jobs outside the scope of the law. The present research makes use of survey data collected from individuals requesting criminal records certificates before and after the introduction of new CBC regulation in Spain – EU Directive 93/2011/EU – which established the obligation to request a criminal record certificate covering sexual crimes for jobs involving frequent contact with children. The analysis detects only a small and unsustained growth in non-mandatory checks following introduction of the new law. However, the results suggest that the danger of the new legislation lies in employers requesting certificates with a higher level of disclosure than is required for the positions on which checks were made mandatory by the new law. In addition, the growth in non-mandatory CBCs observed during this period seems to be related not to the new legislation but to the emergence of tech companies, raising alarm regarding the role of novel forms of policy mobility and the new collaborative economy in limiting the re-entry of individuals with criminal records to the labour market.The author(s) disclosed receipt of the following financial support for the research, authorship, and/or publication of this article: This research was conducted as part of the projects ‘Invisible stripes? A field experiment on the mark of a criminal record in the British labour market’ supported by the British Academy (Ref PF19\100020), ‘Ejecución y supervisión de la pena: Calidad de la intervención, legitimidad y reincidencia’ supported by the Spanish Ministry of Economy and Competitiveness and FEDER, UE (Grant DER2015-64403-P) and ‘Red de Excelencia EmpiriC: Desarrollo de un modelo criminológico y empírico de la política criminal’ supported by the Spanish Ministry of Science and Innovation (Ref. DER2017-90552-REDT)

Replaced Right Hepatic Artery Arising from the Gastroduodenal Artery: a Rare and Challenging Anatomical Variant of the Whipple Procedure

Accurate assessment of the vascular anatomy is a prerequisite of any pancreatic resection, since an unnoticed arterial injury in the context of a complex resection such as Whipple procedure, can seriously jeopardize patient’s safety. This article aims to describe an infrequent anatomic variant of a replaced right hepatic artery originating directly from the gastroduodenal artery and its potential implications for duodenopancreatectomy, as the gastroduodenal artery is routinely divided. We present here two different cases of this arterial abnormality identified during a Whipple procedure and its implications in each different setting. Preoperative identification of anatomical variations is essential for proficient surgical planning. Nevertheless, when detected during surgery, an meticulous dissection of the hepatoduodenal ligament is required to identify all the vascular relations in order to avoid irreversible damage

Short pulsed microwave ablation: computer modeling and ex vivo experiments

Purpose: To study the differences between continuous and short-pulse mode microwave ablation (MWA). Methods: We built a computational model for MWA including a 200 mm long and 14 G antenna from Amica-Gen and solved an electromagnetic-thermal coupled problem using COMSOL Multiphysics. We compared the coagulation zone (CZ) sizes created with pulsed and continuous modes under ex vivo and in vivo conditions. The model was used to compare long vs. short pulses, and 1000 W high-powered short pulses. Ex vivo experiments were conducted to validate the model. Results: The computational models predicted the axial diameter of the CZ with an error of 2-3% and overestimated the transverse diameter by 9-11%. For short pulses, the ex vivo computer modeling results showed a trend toward larger CZ when duty cycles decreases. In general, short pulsed mode yielded higher CZ diameters and volumes than continuous mode, but the differences were not significant (<5%), as in terms of CZ sphericity. The same trends were observed in the simulations mimicking in vivo conditions. Both CZ diameter and sphericity were similar with short and long pulses. Short 1000 W pulses produced smaller sphericity and similar CZ sizes under in vivo and ex vivo conditions. Conclusions: The characteristics of the CZ created by continuous and pulsed MWA show no significant differences from ex vivo experiments and computer simulations. The proposed idea of enlarging coagulation zones and improving their sphericity in pulsed mode was not evident in this study.This work was supported by the Spanish Ministerio de Ciencia, Innovación y Universidades under ‘Programa Estatal de I + D + i Orientada a los Retos de la Sociedad’, Grant N° RTI2018-094357-B-C21

How large is the periablational zone after radiofrequency and microwave ablation? Computer-based comparative study of two currently used clinical devices

Purpose: To compare the size of the coagulation (CZ) and periablational (PZ) zones created with two commercially available devices in clinical use for radiofrequency (RFA) and microwave ablation (MWA), respectively. Methods: Computer models were used to simulate RFA with a 3-cm Cool-tip applicator and MWA with an Amica-Gen applicator. The Arrhenius model was used to compute the damage index (Ω). CZ was considered when Ω > 4.6 (>99% of damaged cells). Regions with 0.6<Ω < 2.1 were considered as the PZ (tissue that has undergone moderate sub-ablative hyperthermia). The ratio of PZ volume to CZ volume (PZ/CZ) was regarded as a measure of performance, since a low value implies achieving a large CZ while keeping the PZ small. Results: Ten-min RFA (51 W) created smaller periablational zones than 10-min MWA (11.3 cm3 vs. 17.2-22.9 cm3, for 60-100 W MWA, respectively). Prolonging duration from 5 to 10 min increased the PZ in MWA more than in RFA (2.7 cm3 for RFA vs. 8.3-11.9 cm3 for 60-100 W MWA, respectively). PZ/CZ for RFA were relatively high (65-69%), regardless of ablation time, while those for MWA were highly dependent on the duration (increase of up to 25% between 5 and 10 min) and on the applied power (smaller values as power was raised, 102% for 60 W vs. 81% for 100 W, both for 10 min). The lowest PZ/CZ across all settings was 56%, obtained with 100 W-5 min MWA. Conclusions: Although RFA creates smaller periablational zones than MWA, 100 W-5 min MWA provides the lowest PZ/CZ.This work was supported by the Spanish Ministerio de Ciencia, Innovación y Universidades under “Programa Estatal de I + D + i Orientada a los Retos de la Sociedad”, Grant N° “RTI2018-094357-B-C21”. Punit Prakash acknowledges support from NIH grant R01EB028848. This project has also received funding from the European Union's Horizon 2020 research and innovation programme under the Marie Sklodowska-Curie grant agreement No 845645

Morphological changes of the pancreas after pancreaticoduodenectomy

The aim of this retrospective study was thus to evaluate postoperative morphological changes in the remnant pancreas after pancreaticoduodenectomy (PD) associated with postoperative pancreatic fistula (POPF). Fifty-one patients subjected to PD were enrolled in the study and allocated into 2 groups according to the presence (n = 16) or absence of POPF (n = 35). A morphological evaluation of the pancreas was conducted for up to a 20 months follow-up on CT scans and compared between groups. No significant differences were observed in morphology between the groups at the different preoperative and PO intervals, regardless of the clinical relevance of the POPF or POPF grade. However, in the overall patient analysis we observed a significant reduction of the entire pancreas over time. In fact, thickness decreased 0.4 mm/month, length 1.2 mm/month and volume 1.17 cm3/month over the PO. The impact of age, POPF, type of anastomosis, surgical technique and PO follow-up (time) was evaluated in a multivariate analysis using the general linear model, but only PO follow-up had a significant influence on the final model (p < 0.001). A significant reduction on pancreatic parenchyma (thickness, length and volume) occurs after PD with no significant differences between patients with or without POPF

Clinical case report: endoluminal thermal ablation of main pancreatic duct for patients at high risk of postoperative pancreatic fistula after pancreaticoduodenectomy

Purpose: Multiple attempts have been made to manage the pancreatic stump and the pancreatic duct in order to reduce the rate of postoperative pancreatic fistula (POPF) after pancreaticoduodenectomy (PD), however radiofrequency-based technologies could help to achieve this goal. Previous encouraging clinical and experimental results support the use of endoluminal thermal ablation (ETHA) of the main pancreatic duct to reduce pancreatic exocrine secretion and hence POPF. We here describe our initial clinical experience with ETHA of the main pancreatic duct in two cases at high risk of POPF. Methods: Two cases underwent PD for malignancy with a high risk of POPF (adenocarcinoma, obese patients, surgical difficulties with heavy intraoperative blood loss, soft pancreas or walled-off pancreatitis and a tight small pancreatic main duct). In both cases, ETHA of the main pancreatic duct was conducted intraoperatively just before Blumgart-type pancreatic-jejunal anastomosis using a ClosureFast catheter (Medtronic, Mansfield, MA, USA) normally used for varicose vein treatment (therefore an off-label use). Results: Although a clear radiological POPF was detected in the second case, the clinical postoperative course in both cases was uneventful. Little pancreatic fluid collected in the abdominal drainage with low levels of amylase enzyme, confirming low exocrine pancreatic function. No other procedure-related complications were detected. Conclusion: Endoluminal thermal ablation of the main pancreatic duct may be a feasible and safe technique to reduce the adverse effects of POPF after PD.This work was supported by the Spanish Ministerio de Ciencia, Innovación y Universidades under “Programa Estatal de I + D + i Orientada a los Retos de la Sociedad”, Grants RTI2018-094357-B-C21 and RTI2018-094357-B-C22

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Data de publicació electrònica: 22/01/202