Optimized nerve block techniques while performing percutaneous hepatic ablation: Literature review and practical use.

Percutaneous image guided thermal ablation has become a cornerstone of therapy for patients with oligometastatic disease and primary liver malignancies. Evolving from percutaneous ethanol injection (PEI), thermal ablation utilizing radiofrequency ablation (RFA) and microwave ablation (MWA) have become the standard approach in the treatment of isolated lesions that fit within the size criteria for curative intent therapy (typically 3-4cm). With the evolution of more intense thermal ablation, such as MWA, the dramatic increase in both the size of ablation zone and intensity of heat generation have extended the limits of this technique. As a result of these innovations, intra-procedural and post-procedural pain have also significantly increased, requiring either higher levels of intravenous sedation or, in some institutions, general anesthesia. In addition to the increase in therapeutic intensity, the use of intravenous sedation during aggressive ablation procedures carries the risk of over-sedation when the noxious insult (i.e. the ablation) is removed, adding further difficulty to post-procedural recovery and management. Furthermore, high subdiaphragmatic lesions become challenging in this setting due to issues relating to sedation and compliance with breath hold/breathing instructions. Although general anesthesia may mitigate these complications, the added resources associated with providing general anesthesia during ablation is not cost effective and may result in substantial delays in treatment. The reduction of Aerosol Generating Medical Procedures (AGMP), such as intubation due to the COVID-19 Pandemic, must also be taken into consideration. Due to the potential increased risk of infection transmission, alternatives to general anesthesia should be considered when safe and possible. Upper abdominal regional nerve block techniques have been used to manage pain related to trauma, surgery, and cancer; however, blocks of this nature are not well described in the interventional radiology literature. The McGill University group has developed experience in using such blocks as splanchnic, celiac and hepatic hilar nerve blocks to provide peri-procedural pain control [1]. Since incorporating these techniques (along with hydrodissection with tumescent anesthesia), we have also observed in our high volume ablation center a dramatic decrease in the amount of sedatives administered during the procedure, a decrease in patient discomfort during localization and ablation, as well as decreased pain post-procedure. Faster time to discharge and overall reduction in room procedural time serve as added benefits. The purpose of this publication is to outline and illustrate the practical application and use of nerve block/regional anesthesia techniques with respect to percutaneous hepatic thermal ablation.

Current locoregional therapies and treatment strategies in hepatocellular carcinoma.

Locoregional therapies (lrts) play an important role in the treatment of hepatocellular carcinoma (hcc), with the aim of increasing overall survival while preserving liver function. Various forms of lrt are available, and choosing the best one depends on technical aspects, liver morphology, tumour biology, and the patient's symptoms. The purpose of the present review article is to provide an overview of the current evidence relating to the use of percutaneous ablation, transarterial chemoembolization, and transarterial radioembolization for the curative or palliative treatment of hcc. Special situations are also reviewed, including the combined use of systemic therapy and lrt, indications and techniques for bridging to transplant and downstaging, and the use of lrt to treat patients with hcc and macrovascular invasion.

Production and certification of an enzyme reference material for adenosine deaminase 1 (BCR 647).

BACKGROUND: We describe the preparation of a lyophilised reference material containing purified human adenosine deaminase 1 and the certification of its catalytic concentration. METHODS: The enzyme was purified from human erythrocytes. RESULTS: The enzyme was >99% pure on polyacrylamide gel electrophoresis. Only trace amounts (<0.4%) of alanine aminotransferase, aspartate aminotransferase and L-lactate dehydrogenase were detected in the purified fraction. The purified adenosine deaminase had a molar mass of 41600 g/mol and an isoelectric pH at 4.7, 4.85 and 5.0. The material was prepared by diluting the purified adenosine deaminase in a matrix containing 50 mmol/l Tris-HCl buffer pH 7.4 and 30 g/l human serum albumin; dispensing in vials and freeze-drying. The batch was homogeneous and the predicted loss of adenosine deaminase activity per year on the basis of accelerated degradation studies was 0.006% at -20 degrees C and 0.04% at 4 degrees C. The certified value for adenosine deaminase catalytic concentration in the reconstituted reference material is (2.55+/-0.09) microkat/l when measured by the method that uses adenosine as substrate and glutamate dehydrogenase as auxiliary enzyme at 37 degrees C. CONCLUSIONS: The material can be used to verify the comparability of results from different laboratories, for intra-laboratory quality control, or for calibration of the adenosine deaminase catalytic concentration measurements.

Production and certification of an enzyme reference material for creatine kinase isoenzyme 2 (CRM 608).

We describe the preparation of a lyophilized material containing purified human creatine kinase 2 (CK-MB), and the certification of its catalytic concentration. The material can be used to verify the comparability of results from different laboratories, for intra-laboratory quality control, or for calibration of the creatine kinase 2 catalytic concentration measurements. The enzyme was purified from human heart by ethanol precipitation and chromatography successively on DEAE-Sephacel and Blue-Sepharose. The purified enzyme had a specific activity of 998.4 U/mg and was > 99% pure on polyacrylamide gel electrophoresis. The material was examined for several possible contaminating enzymes, which were found to be absent. The purified creatine kinase 2 had two subunits (B and M) with molecular masses of 43,650 and 41,700 g/mol, respectively, and an isoelectric point at pH 5.8. The material was prepared by diluting the purified creatine kinase 2 in a matrix containing 25 mmol/L PIPES buffer, pH 7.2, 2 mmol/L ADP, 5 mmol/L 2-mercaptoethanol, 154 mmol/L sodium chloride and 50 g/L human serum albumin, dispensing it into vials and freeze-drying. The batch was shown to be homogeneous. The loss of enzyme activity on storage at -20 degrees C is predicted to be less than 0.18% per annum on the basis of accelerated degradation studies. The catalytic concentration of creatine kinase in samples of the reconstituted material is certified to be 67.2+/-1.8 U/L (1.12+/-0.03 microkat/L) when measured, at 30 degrees C, by the Recommended Method of the International Federation of Clinical Chemistry.

Production and certification of an enzyme reference material for pancreatic alpha-amylase (CRM 476).

We describe the preparation of a lyophilized material containing purified human pancreatic alpha-amylase and the certification of its catalytic concentration. The enzyme was purified from human pancreas by ammonium sulphate precipitation and chromatography successively on DEAE-Sephacel, CM-Sepharose and Sephadex G-75. The purified enzyme had a specific activity of 52.9 kU/g protein and was > 99% pure on polyacrylamide gel electrophoresis. Only trace amounts of lipase and lactate dehydrogenase were detected in the purified fraction. The purified pancreatic alpha-amylase had a molar mass of 57,500 g/mol and an isoelectric point at 7.1. The material was prepared by diluting the purified alpha-amylase in a matrix containing PIPES buffer 25 mmol/l, pH 7.0, sodium chloride 50 mmol/l, calcium chloride 1.5 mmol/l, EDTA 0.5 mmol/l and human serum albumin 30 g/l, dispensing in ampoules and freeze-drying. The ampoules were homogeneous and the yearly loss of activity on the basis of accelerated degradation studies was less than 0.01% at -20 degrees C. The certified value for alpha-amylase catalytic concentration in the reconstituted reference material is 555 U/l +/- 11 U/l when measured by the specified method at 37 degrees C. The material can be used to verify the comparability of results from laboratories, for intra-laboratory quality control or for calibration of alpha-amylase catalytic concentration measurements.

Fluorometric study of serum in patients with chronic renal failure.

Sera from 84 uremic patients (53 on conservative treatment and 31 on hemodialysis) were studied spectrofluorometrically in comparison with 20 normal subjects and 11 jaundiced patients. Serum fluorescence in patients with chronic renal failure was significantly higher than in normals and patients with jaundice. Two types of serum fluorescence spectra (A and B) were predominant (93%) and all the patients who were free of any medication for more than two months exhibited the type A spectrum. The intensity of fluorescence was in parallel with the serum creatinine levels. Dialysis experiments of uremic serum in vitro showed that the substance(s) responsible for its fluorescence is dialyzable. Moreover hemodialysis caused a significant decrease in the intensity of serum fluorescence in dialyzed patients. Administration of pyridoxine intravenously caused quite different results in normal subjects and uremic patients. Namely normals presented a transient (for several minutes) increase in serum fluorescence whereas uremics showed a higher and more permanent increase which lasted for several days.

The diagnostic value of protein bound serum fucose in cancer of the breast.

Protein bound serum fucose levels were measured in women with cancer of the breast and in normal women serving as controls. Thirteen healthy women gave a mean value of 13.9 plus or minus 2.4 milligrams per cent, which was not significantly different from the figure of 15.0 plus or minus 3.1 milligrams per cent obtained from 11 patients with operable cancer of the breast, Stage I and II. Only the serums from nine patients with disseminated cancer of the breast showed a significantly elevated fucose concentration of 18.8 plus or minus 3.6 milligrams per cent. It is concluded that serum fucose determination is of no diagnostic value in the early stages of cancer of the breast.