Guidelines E1 EFSUMB Guidelines on Interventional Ultrasound (INVUS), Part I General Aspects (long Version) EFSUMB Leitlinien Interventioneller Ultraschall (INVUS), Teil I Allgemeine Aspekte (Langversion) Authors T. Lorentzen1, C. P. Nolsøe1, C. Ewertsen2, M. B. Nielsen2, E. Leen3, R. F. Havre4, N. Gritzmann5, B. Brkljacic6, D. Nürnberg7, A. Kabaalioglu8, D. Strobel9, C. Jenssen10, F. Piscaglia11, O. H. Gilja12, P. S. Sidhu13, C. F. Dietrich14, 15 Affiliations Affiliation addresses are listed at the end of the article. Key words Abstract Zusammenfassung ●" guideline ! ! ●" ultrasound guidance This is the first part of the Guidelines on Interven- Der erste Teil der Leitlinien „interventionelle So- ●" hygiene tional Ultrasound of the European Federation of nografie” der European Federation of Societies for ●" microbiology Societies for Ultrasound in Medicine and Biology Ultrasound in Medicine and Biology (EFSUMB) ●" safety (EFSUMB) and covers all general aspects of ultra- erörtert die allgemeinen Aspekte sonografisch ge- sound-guided procedures (long version). stützter und assistierter diagnostischer und thera- peutischer Interventionen im Abdomen (Langver- sion). Introduction equipment and different types of transducers. ! INVUS is now an integrated part of transcuta- Ultrasound (US), both as a diagnostic modality neous abdominal and superficial (small part) US. as well as a guidance technique for interventional Furthermore, INVUS is a natural component of procedures, has developed into an invaluable tool various endoluminal US exams such as transrec- in virtually all medical specialties. The real-time tal, transvaginal, transbronchial and transgastric nature of US combined with low cost and high (endoscopic) US. Finally, INVUS is also feasible availability, has allowed US to become the modal- during intra-operative and laparoscopic US. ity of first choice for guidance of a broad variety of Performing a competent INVUS procedure involves interventional procedures. the successful combination of theoretical knowl- The history of interventional US (INVUS) goes back edge and practical skills at a high level: to the 1960 s, when reports on the utility of US to ▶ Knowledge of normal and pathologic US anato- guide renal biopsies, pleural fluid aspiration, and my including pitfalls and artifacts Bibliography A-mode US-guided amniocentesis were published ▶ Knowledge of the puncture principle and aux- DOI http://dx.doi.org/ [1]. A milestone in early INVUS was the develop- iliary US techniques such as Doppler and CEUS 10.1055/s-0035-1553593 ment of a special A-mode transducer with a central ▶ Knowledge of the INVUS apparatus used in- Published online: 2015 hole to enable amniocentesis and other punctures cluding all potential complications This document was downloaded for personal use only. Unauthorized distribution is strictly prohibited. Ultraschall in Med 2015; 36: E1–E14 © Georg Thieme Verlag to be performed safely. In the 1970 s and 1980 s, ▶ Dexterity and stereotactic skills. Part I of the Eu- KG Stuttgart · New York · the technological development of US systems and ropean Federation of Societies for Ultrasound in ISSN 0172-4614 transducers was significant, and US systems with Medicine and Biology (EFSUMB) Guidelines on real-time grayscale imaging (B-mode) and Doppler interventional ultrasound adresses general as- Correspondence Prof. Dr. med. Christoph F. mode became commercially available and widely pects of US-guided interventions. The methods Dietrich distributed. During these two decades, the classic of guideline development are described in the Med. Klinik 2, INVUS techniques of biopsy and drainage/puncture introduction to the EFSUMB Guidelines on In- Caritaskrankenhaus Bad were further refined to become established tech- terventional Ultrasound [3]. Levels of evidence Mergentheim niques. First reports of US-guided tissue ablation (LoE) and Grades of Recommendations (GoR) Uhlandstr. 7 appeared in the 1980 s, but the different ablation have been assigned according to the Oxford Cen- D-97980 Bad Mergentheim techniques did not become established and clini- tre for Evidence-based Medicine criteria (March Germany cally implemented until the 1990 s [2]. 2009 edition) [http://www.cebm.net/oxford- Tel.: ++ 49/(0)79 31/58–22 01/ 22 00 Interventional ultrasound (INVUS) consists of a centre-evidence-basedmedicine-levels-evi- Fax: ++ 49/(0)79 31/58–22 90 variety of diagnostic as well as therapeutic proce- dence-march-2009] [3]. [email protected] dures, and may be performed with a variety of Lorentzen T et al. EFSUMB Guidelines on … Ultraschall in Med 2015; 36: E1–E14 E2 Guidelines Imaging and INVUS out the entire procedure may be used. CEUS is indicated in several ! situations and aspects of interventional US. Ultrasound guidance for interventional procedures is utilized on different levels ranging from a “courtesy” look with the transducer Biopsy from viable areas prior to placing a pleural or ascitic drainage catheter to using so- With CEUS, the viability of tumor tissue, signified by the presence phisticated techniques of contrast-enhanced ultrasound (CEUS) fu- of vascularity, can be reliably evaluated, and CEUS-guided biopsy sion imaging with CT or MR imaging [4]. increases the diagnostic yield by 10 % and decreases the false neg- ative rate especially in large tumors with areas of necrosis [7, 8]. B-mode imaging In preparation for a US-guided procedure, it is important to choose Biopsy of “invisible” or poorly visualized/delineated the appropriate transducer and imaging program (presetting/ap- lesions plication) and to select the correct interventional apparatus. For When previous CT, MR or PET-CT imaging has demonstrated a abdominal or thoracic interventions, a curved or phased array suspicious lesion and a biopsy for a definitive diagnosis is requir- transducer with a frequency of 3.5 – 6 MHz should be chosen. For ed but the lesion is not seen or is poorly visualized with US, CEUS a superficial lesion, a linear high-frequency transducer with a fre- may be helpful in two ways: 1) The target lesion may become quency of 7.5 – 15 MHz should be selected. Optimal and clear vi- “clearly visualized” on CEUS, or 2) Additional lesions that poten- sualization of the puncture target and the puncture route is of ut- tially render themselves more accessible to biopsy become evi- most importance. A high-contrast image with a low dynamic dent and can then be biopsied under CEUS guidance [9 – 11]. range, which appears somewhat crispy or “hard” compared to the normal diagnostic US image is preferable. This enables better vi- Guidance, monitoring and follow-up in percutaneous sualization of needles and other devices used in US-guided proce- thermal ablation of abdominal tumors dures. Use of “crossbeam” and other imaging improvement fea- The ablation volume may be of a similar texture to the surround- tures may reduce reflections from the needle and blur the outline ing normal tissue on B-mode US, however, the clarity achieved of the needle tip. Further adjustments of image size, field of view, with CEUS is playing an increasingly important role in monitor- gain, time gain compensation (TGC), depth and number of focal ing post-ablation local recurrence and ablation volume viability, zones may often be necessary to obtain the best visualization of as well as demonstrating new lesions [12 – 16]. the target and puncture device. Whenever US visibility is an issue, CEUS or fusion imaging should be considered. Emerging applications Besides the indications for CEUS in interventional US described Recommendation 1 above, a number of other uses may serve as alternatives to exist- ing techniques or offer a possible alternative where no current Ultrasound is safe and effective for selecting punctures site technique is available. Examples of indications include but are and subsequent guidance. (LoE 4, GoR C). Strong consensus not limited to: A) replacement for a conventional X-ray contrast (100 %). study, i. e., fistulography (including CEUS via nephrostomy cathe- ter), B) diagnosis and monitoring of all stages of post-procedure bleeding, C) improved visualization of all types of fluid collec- Doppler imaging tions other than blood. The use of Doppler in interventional US might be helpful in some circumstances as color Doppler may be used to map the relation- Avoidance of interventional procedures ship between the target and any vessel that needs to be avoided CEUS may prevent patients from undergoing an interventional during puncture [5]. However, vascular structures are occasional- procedure with the associated morbidity e. g. liver biopsy if CEUS ly impossible to avoid and the procedural strategy must be direc- can allow for a definitive diagnosis of a malignant or benign abnor- ted towards the best approach dictated by the prevailing circum- mality. stances [6]. If any doubt exits as to whether the lesion is vascular or avascular, Recommendation 3 color Doppler should be applied. If this still does not solve the CEUS can be helpful to avoid necrotic areas in percutaneous ambiguity, CEUS should be considered. This document was downloaded for personal use only. Unauthorized distribution is strictly prohibited. biopsy of intra-abdominal tumors. (LoE 4, GoR C). Strong con- sensus (100 %). Recommendation 2 Ultrasound color Doppler can be helpful to avoid inadvertent puncture of vascular structures. (LoE 4, GoR C). Strong consen- Recommendation 4 sus (100 %). CEUS can be helpful in identifying biopsy targets poorly or not visualized with fundamental