Interventional radiology procedures in the liver. Biopsy, drainage, and ablation

The utility of liver biopsy in 2020

PURPOSE OF REVIEW

Over the past decade, imaging modalities and serological tests have emerged as important tools in the evaluation of liver diseases, in many cases supplanting the use of liver biopsy and histological examination. Nonetheless, the accuracy and diagnostic value of these methods may not always be conclusive and the assessment of liver histology often remains the gold standard for diagnostic evaluation. The purpose of this review is to summarize the current role of liver biopsy in contemporary hepatology practice.

RECENT FINDINGS

Technical factors were found to influence the diagnostic value of liver biopsy and histological examination of the liver, including specimen number and size (preferably ≥3 nonfragmented specimens of >20 mm in length), needle diameter (1.6 mm Menghini), number of passes (mean 2.5), imaging-guidance, and operator experience. Liver biopsy was demonstrated to be diagnostically valuable in the evaluation of persistently abnormal liver tests of unclear cause, with histology pointing to a specific diagnosis in 84% of patients. Although coagulation abnormalities continue to be an important concern when performing liver biopsy, their influence on complication risk remains unclear. Implementation of less stringent preprocedural coagulation thresholds decreased preprocedural transfusions without increasing the bleeding rate. Serious complications associated with percutaneous liver-biopsy (PLB) and transjugular liver-biopsy are similar, but pain appears to be more common with PLB.

SUMMARY

Histopathological evaluation continues to be fundamentally important in assessing hepatic disease, and liver histology remains the most accurate approach to assess fibrosis and assign prognosis.

Lung and Abdominal Biopsies in the Age of Precision Medicine

Image-guided percutaneous needle biopsies (PNBs) are one of the most common procedures performed in radiology departments today. Rapid developments in precision medicine, which identifies molecular and genomic biomarkers in cancers, have ushered a new paradigm of oncologic workup and treatment. PNB has conventionally been used to establish a benign or malignant nature of a lesion during initial diagnosis or in suspected metastatic or recurrent disease. However, increasing amounts of tissue are being required to meet the demands of molecular pathologic analysis, which are now being sought at multiple time points during the course of the disease to guide targeted therapy. As primary providers of biopsy, radiologists must be proactive in these developments to improve diagnostic yield and tissue acquisition in PNB. Herein, we discuss the important and expanding role of PNB in the age of precision medicine and review the technical considerations of percutaneous lung and intra-abdominal biopsy. Finally, we examine promising state-of-the-art techniques in PNB that may safely increase tissue acquisition for optimal molecular pathologic analysis.

US-GUIDED PERCUTANEOUS CORE LIVER BIOPSY: ANALYSIS OF 171 CASES FROM A SINGLE ONCOLOGY SERVICE

BACKGROUND

Though strongly suggestive of metastasis, focal lesions on liver scans of oncological patients require histological confirmation for the prescription of adequate treatment.

OBJECTIVE

To evaluate the safety and efficacy of US-guided percutaneous core liver biopsy.

METHODS

Descriptive, cross-sectional study based on secondary data from 171 patients submitted to US-guided percutaneous core liver biopsy at the diagnostic radiology service of the Ceará Cancer Institute (ICC, Brazil) between February 2010 and March 2015. Quantitative data were expressed in absolute numbers or percentages, with emphasis on the rate of complications observed within six hours after the procedure.

RESULTS

The overall accuracy was 96.4%. The overall rate of complications was 2.3%, three quarters of which was due to hemorrhage. Age over 50 years was positively associated with accuracy. No deaths occurred within the period of observation.

CONCLUSION

Our findings support the claim that the use of thick biopsy needles improves diagnostic accuracy. The few complications observed were non-lethal and predominantly hemorrhagic.

Needlestick Injuries in Interventional Radiology Are Common and Underreported

Purpose To determine the prevalence of and risk factors for needlesticks in interventional radiology physicians, as well as the attitudes, behaviors, and conditions that promote or interfere with reporting of these injuries. Materials and Methods A total of 3889 interventional radiologists from academic and private practice in the United States were surveyed by emailing all interventional radiologist members of the Society of Interventional Radiology, including attending-level physicians and trainees (April-August 2016). The institutional review board waived the need for consent. Questions inquired about the nature, frequency, and type of needlestick and sharps injuries and whether and to whom these incidents were reported. Stepwise regression was used to determine variables predicting whether injuries were reported. Results In total, 908 (23%) interventional radiologists completed at least a portion of the survey. Eight hundred fourteen (91%) of 895 respondents reported a prior needlestick injury, 583 (35%) of 895 reported at least one injury while treating an HIV-positive patient, and 626 (71%) of 884 reported prior training regarding needlestick injury. There was, on average, one needlestick for every 5 years of practice. Most needlestick or sharps injuries were self inflicted (711 [87%] of 817) and involved a hollow-bore device (464 [56%] of 824). Only 566 (66%) of 850 injuries were reported. The most common reasons for not reporting included perceived lack of utility of reporting (79 [28%] of 282), perceived low risk for injury (56 [20%] of 282), noncontaminated needle (53 [19%] of 282), too-lengthy reporting process (37 [13%] of 282), and associated stigma (23 [8%] of 282). Only 156 (25%) of 624 respondents informed their significant other. Stepwise regression assessing variables affecting the likelihood of reporting showed that male sex (P = .009), low-risk patient (P < .0001), self injury (P = .010), trainee status (P < .0001), and the total number of prior injuries (P = .019) were independent predictors of not reporting. Conclusion Needlestick injuries are ubiquitous among interventional radiologists and are often not reported. ^© RSNA, 2017 Online supplemental material is available for this article.

Perk Station--Percutaneous surgery training and performance measurement platform

MOTIVATION

Image-guided percutaneous (through the skin) needle-based surgery has become part of routine clinical practice in performing procedures such as biopsies, injections and therapeutic implants. A novice physician typically performs needle interventions under the supervision of a senior physician; a slow and inherently subjective training process that lacks objective, quantitative assessment of the surgical skill and performance. Shortening the learning curve and increasing procedural consistency are important factors in assuring high-quality medical care.

METHODS

This paper describes a laboratory validation system, called Perk Station, for standardized training and performance measurement under different assistance techniques for needle-based surgical guidance systems. The initial goal of the Perk Station is to assess and compare different techniques: 2D image overlay, biplane laser guide, laser protractor and conventional freehand. The main focus of this manuscript is the planning and guidance software system developed on the 3D Slicer platform, a free, open source software package designed for visualization and analysis of medical image data.

RESULTS

The prototype Perk Station has been successfully developed, the associated needle insertion phantoms were built, and the graphical user interface was fully implemented. The system was inaugurated in undergraduate teaching and a wide array of outreach activities. Initial results, experiences, ongoing activities and future plans are reported.

Emergent ultrasound interventions

The interventionist can perform many emergent procedures with ultrasound guidance, because of its real-time, multiplanar imaging capability and portability. With the use of color Doppler, additional important information, such as aberrant vessels, can be ascertained to help plan needle trajectory. Ultrasound is also useful for nonemergent procedures, such as biopsies. All interventionists are encouraged to be facile with the use of ultrasound.