79th PostGraduate Assembly in Anesthesiology 2025

Title: Anesthesia Considerations and Planning for a Histotripsy Procedure in a Non-Operating Room Setting

Authors: Vanchi Ly BS^¹^,², Anthony Zisa BS^¹^,3, Yan Lai MD, MPH, FASA, FASRA, CBA, LAc¹

Introduction:

Many liver tumors are conventionally treated with thermal ablation, chemoembolization and radiation therapy which may require invasive access, interrupt systemic therapies, or struggle with tumors in difficult anatomical locations³.
Histotripsy has been developed as a minimally invasive technique to address these issues--using focused ultrasound-induced acoustic cavitation to destroy hepatic tumors³. It is an alternative for patients with complex tumors, anatomical challenges, and significant comorbidities ².
While the absence of puncture reduces hemorrhagic risk, histotripsy may activate coagulation and elevate thrombotic potential.
This case highlights the anesthetic concerns for liverhistotripsy performed in a remote setting with non-OR anesthesia (NORA) environment for an medically complex patient.

Case Description:

A 79-year-old man with metastatic sigmoid colon adenocarcinoma to the liver underwent a liver histotripsy in interventional radiology suite.

Comorbidities: CAD with PCI and drug-eluting stents, severe COPD, hypertension, and type 2 diabetes.
Home medications (daily): Aspirin 81mg, clopidogrel 75mg, amlodipine 10mg, lisinopril 20mg, metoprolol succinate 100mg, insulin and oral anti-glycemics, bronchodilators, inhaled corticosteroids,statin, PPI, and alprazolam PRN.
Exercise tolerance adequate, and he was not oxygen-dependent.

General anesthesia was induced, and a double-lumen endotracheal tube was placed via direct laryngoscopy. The 4.5-hour procedure proceeded without intraoperative complications.

Postoperatively, the patient developed a hypertensive crisis with acute respiratory distress.
Pulmonary congestion on chest radiography.
Management: IV antihypertensives, diuretics, and bronchodilators led to stabilization and oxygen weaning.

The patient was discharged the following day.

Discussion:

The patient’s complex cardiopulmonary history and anticoagulant use posed anesthetic challenges throughout the perioperative period.

Lung isolation with double lumen ETT for better liver lobe exposure: This optimizes the acoustic window, prevented air from interfering with ultrasound.
Hemodynamic control: Hemodynamic control was critical given the patient’s cardiac, stroke risks, and anticoagulant use.
High risk in remote location: The procedure occurred in a remote setting with non-OR anesthesia(NORA) with limited personnel and no on-site bloodbank with major limitations on massive blood transfusion. If a major complication occurred during the procedure, a plan was in place for a transfer to a tertiary facility.

Conclusions:

This case underscores the need for proactive, tailored anesthetic planning in high-risk patients undergoing novel procedures such as histotripsy, especially when performed in resource-limited, remote procedural locations.

The combination of significant cardiopulmonary comorbidities, ongoing antiplatelet therapy, and the physiologic demands of one-lung ventilation required careful preoperative evaluation, vigilant intraoperative management, and rapid postoperative intervention.
Because histotripsy is a novel modality with evolving procedural workflows, proactive planning and close communication among anesthesia, interventional radiology, and perioperative support teams were essential to maintaining patient safety and ensuring positive outcomes.

79th PostGraduate Assembly in Anesthesiology 2025

Anesthesia Considerations and Planning for a Histotripsy Procedure in a Non-Operating Room Setting

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