Emergent ultrasound interventions

Urgent ultrasound-guided interventional procedures

Interventional radiology procedures have become a fundamental part of radiology, resulting in faster diagnoses and in safer, more effective, and more precise treatments, all of which are important, and even more so when referring to urgent situations, where time is of the essence. In this context, the use of ultrasound to guide interventional procedures enables real-time viewing in multiple planes that can be done at the patient's bedside, which is a great advantage in critical patients. We review the indications and technical aspects of the most common procedures related with radiological care of urgent patients.

Deep circumflex iliac artery pseudoaneurysm as a complication of paracentesis

We report a case of a pseudoaneurysm arising from the deep circumflex iliac artery, in an end-stage renal disease patient with gross ascitis, presenting with an anterior abdominal wall hematoma following paracentesis. Duplex Doppler sonography confirmed the presence of the pseudoaneurysm and multidetector computed tomography angiography delineated the detailed arterial anatomy.

[US-guided interventional procedures: what a radiologist needs to know]

US has important advantages in guiding interventional procedures: it is economical and widely available, it does not use ionizing radiation, and it requires less time than other techniques. US guidance can be provided using devices adapted to probes or using the freehand technique (holding the needle in one hand and the probe in the other). US-guided procedures require careful planning, adequate hemostasis or a directly compressible puncture site, the patient's informed consent, and appropriate measures to ensure asepsis and anesthesia. The technique involves introducing the needle or catheter through the plane of the US slice. The advance of the needle is controlled in real time. High resolution linear probes are ideal for interventional procedures in superficial tissues, but 3.5 MHz probes are required for procedures in deep tissues. The most common procedures include biopsies, drainages, and percutaneous injections. Biopsies can be carried out using fine needles to obtain material for cytological study (fine-needle aspiration cytology) or using large needles to obtain specimens for histologic study (core biopsy). Core biopsy is more sensitive and more specific, and it has a low rate of complications. Drainage almost always involves placing a catheter in a fluid collection; it can be done using the Seldinger techniques, trocars, or pleural catheters. US-guided percutaneous injections can be used to inject substances into infectious lesions, tumors, or nerve plexuses, and they are especially useful in musculoskeletal disease.

Ultrasound-guided interventional radiology in critical care

Ultrasound-guided intervention is becoming an increasingly popular and valuable tool in the critical care setting. In general, image-guided procedures can expedite wait times and increase the accuracy, safety, and efficacy of many procedures commonly performed within intensive care units. In the intensive care unit setting, ultrasound has particular advantages over other imaging modalities such as computed tomography and fluoroscopy, including real-time visualization, portability permitting bedside procedures, and reduced exposure to nephrotoxic contrast agents. We review the technical and procedural aspects of a number of ultrasound-guided interventions appropriate for critical care patients. These include central venous catheter deployment, thoracentesis, paracentesis, and drainage of a wide variety of abscesses, and percutaneous nephrostomy, percutaneous cholecystectomy, and inferior vena cava filter placement. Although we believe ultrasound is significantly underutilized in critical care today, we anticipate that with the improvement of ultrasound technology and the innovation of new ultrasound-guided procedures, the role of ultrasound in the intensive care unit will continue to expand, with bedside ultrasound-guided interventions increasingly becoming the norm.