Thermoablation of Liver Metastases: Efficacy of Temporary Celiac Plexus Block

Hepatic Hilar Nerve Block for Hepatic Interventions: Anatomy, Technique, and Initial Clinical Experience in Thermal Ablation of Liver Tumors

Background Image-guided procedures for treatment of liver diseases can be painful and require heavy sedation of the patient. Local-regional nerve blocks improve pain control and reduce oversedation risks, but there are no documented liver-specific nerve blocks. Purpose To develop a safe and technically simple liver-specific nerve block. Materials and Methods Between March 2017 and October 2019, three cadavers were dissected to evaluate the hepatic hilar anatomy. The hepatic hilar nerves were targeted with transhepatic placement of a needle adjacent to the main portal vein, under US guidance, and evaluated with use of an injection of methylene blue. A hepatic nerve block, using similar technique and 0.25% bupivacaine, was offered to patients undergoing liver tumoral ablation. In a prospective pilot study, 12 patients who received the nerve block were compared with a control group regarding complications, safety, pain scores, and intraoperative opioid requirement. Student t tests were used to compare the groups' characteristics, and Mann-Whitney U tests were used for the measured outcomes. Results Cadaver results confirmed that the hepatic nerves coursing in the hepatic hilum can be targeted with US for injection of anesthetic agents, with adequate spread of injected methylene blue around the nerves in the hepatic hilar perivascular space. The 12 participants (mean age ± standard deviation, 66 years ± 13; eight men) who received a hepatic hilar block before liver thermal ablations demonstrated reduced pain compared with a control group of 12 participants (mean age, 63 years ± 15; eight men) who received only intravenous sedation. Participants who received the nerve block had a lower mean visual analog scale score for pain than the control group (3.9 ± 2.4 vs 7.0 ± 2.8, respectively; P = .01) and decreased need for intraprocedural fentanyl (mean dose, 152 μg ± 78.0 vs 235.4 μg ± 58.2, respectively; P = .01). No major complications occurred in the hepatic hilar nerve block group. Conclusion A dedicated hepatic hilar nerve block with 0.25% bupivacaine can be safely performed to provide anesthesia during liver tumoral ablation. © RSNA, 2021.

A 96-hour continuous wound infiltration with ropivacaine reduces analgesic consumption after liver resection: A randomized, double-blind, controlled trial

BACKGROUND

Continuous wound infiltration (CWI) with local anesthetics to reduce morphine consumption in postoperative pain management after open liver resection in patients with cancer.

METHODS

This single-center randomized double-blind study allocated patients requiring resection of liver metastases to receive a 3.75 mg/mL ropivacaine (ROP) infiltration, followed by a 2 mg/mL ROP CWI, or placebo (P) for 96 hours. Postoperative analgesia included acetaminophen and patient-controlled analgesia morphine pump. The primary endpoint was to investigate the reduction of total morphine consumption (mg/kg) over the first 96 postoperative hours.

RESULTS

Eighty-five patients were recruited, and randomized (ROP: 42, P: 43) between 2009 and 2014. The median morphine consumption significantly decreased in the ROP arm in the first 96 postoperative hours (ROP: 1.0, P: 1.5 mg/kg; P = 0.026). Twenty-three (27%) patients had grade 3 adverse events (ROP: 14, P: 9) and four experienced grade 3 treatment-related adverse events (ROP: mental confusion [n = 1], hallucinations [n = 2], P: hematoma [n = 1]). Two (5%) patients showed a wound inflammation (ROP: 1, P: 1). Nine (11%) patients experienced at least one serious adverse event (ROP: 6, P: 3); none related to treatment.

CONCLUSION

Preperitoneal CWI of 2 mg/mL ROP significantly reduces intravenous morphine consumption during the 96 postoperative hours resulting in an absolute reduction of 0.5 mg/kg.

Celiac plexus block for visceral pain

Celiac plexus block has long been used to provide analgesia for upper abdominal pain. In particular, neurolytic celiac plexus block has been advocated for pancreatic cancer pain. In this article, recent advances clarifying the role and limitations of neurolytic celiac plexus block are reviewed. Neurolytic celiac plexus block provides persistent augmented analgesia when used as an adjunct to systemic opiates, but does not reliably decrease opiate requirements. In addition, neurolytic celiac plexus block may prolong survival, but the data supporting this remain controversial. The optimal technique for accomplishing neurolytic celiac plexus block remains undetermined.