CT or Ultrasound Guided Ablations of Liver/Kidney/Lungin IR
Barbara Wilkey, MD
Bob Ryu, MD
Purpose: The purposes of this document are
1)To provide education pertaining to the process of CT or Ultrasound Guided Ablations in IR.
2)To provide peri-procedure management suggestions.
Content: This content is a combination of published literature and peer recommendation (Interventional Radiology and Anesthesiology).
The procedure
Most common indications: ablation of primary or secondary tumors of the liver or kidney by applying thermal energy under imaging guidance.
Length of procedure: 1-2 hours of IR MD time (this can be longer if ablating multiple and/or large lesions).
Antibiotic prophylaxis: yes, depending on location: enteric coverage for liver and renal, skin coverage for lung
Imaging: CT or CT fluoroscopy, ultrasound
Contrast agents: None routinely. Intravenous iodinated contrast is sometimes given after liver ablations to assess the treatment area
Ancillary procedures: None routinely, although biopsy is occasionally performed before ablation. Chest tube placement may be needed for intra-procedural pneumothorax in lung ablation cases.
Preprocedural testing: CT/MR/US/CXR, routine laboratory tests including comprehensive blood chemistries (LFTs, Cr, GFR, etc), hematology (plt >50K, WBC), coagulation parameters (INR<2), type and screen.
Patient positioning: usually supine for liver (right upper quadrant and epigastrium), with arms over the head. Renal ablations are usually prone. Lung ablations may be prone or supine, depending upon location.
Procedural details: Ultrasound/CT guided ablation probe(s) placement into the targeted lesion, confirmation of placement and treatment plan, activation of microwave/cryablation system to achieve the desired ablation morphology/size, intra/post procedural imaging to assess ablation result, probe removal and manual compression for site hemostasis.
The patient
The pre-anesthesia assessment starts with a standard evaluation, with careful attention to the disease process requiring intervention. Airway considerations are important, especially when anticipating a difficult airway in the CT scanner.
General anesthesia is necessary for microwave ablations in any anatomic location.
Microwave ablation is generally quite painful.
Cryoblations in any anatomic location can be done under MAC. Consider general anesthesia for kidney cryoablations done in the CT scanner in patients with known or suspected difficult airways. Cryoablations are generally not painful and can be safely performed with conscious sedation.
Room Setup standard set up plus IV pumps for any necessary infusions. Prone view should be available for kidney procedures. Please note, IR has their own gel rolls for prone positioning. Consider additional IV if ablation risks damage to major vascular structure.
Anesthesia induction: Induction agent of choice.
Maintenanceof choice.
Emergence/extubation/disposition is at the discretion of the anesthesia team. Generally floor status after CVC PACU stay.
Procedural Risks
-Pneumothorax
- Hemoptysis
- Liver/kidney injury (hematoma)
-Significant bleeding (slightly higher risk in renal/lung cryoablation cases)
-Post ablation pain