Randomized double-blind clinical trial of celiac plexus block for percutaneous biliary drainage

Evaluation of paravertebral blocks in improving post-procedural pain and decreasing hospital admission after microwave ablation of liver tumors

Although ablations are performed with conscious sedation or general anesthesia, microwave ablations can be painful post procedure. Newer analgesic modalities, including regional blocks, have promoted the proliferation of less invasive anesthesia care for ablative procedures. This study evaluates whether bilateral paravertebral blocks reduce the need for additional analgesics in comparison to unilateral blocks in microwave ablations. In this retrospective study, individuals undergoing microwave ablation who underwent unilateral versus bilateral nerve blocks at a single institution from 2017 to 2019 were compared. Categorical variables were analyzed using Pearson's chi-squared tests. Comparisons of means were completed using multiple T-tests corrected using the Holm-Sidak method with α = 0.05. Regression modeling was used to identify factors related to increased MME (milligram morphine equivalent) usage and post-procedure admission rates. A total of 106 patients undergoing 112 liver MWA procedures were included in this analysis, with patients receiving either a bilateral or unilateral block. Pre-procedural characteristics demonstrated no significant differences in age or gender. Bilateral blocks were associated with decreased usage of gabapentin (14% vs. 0%, p = 0.01) and a lower rate of post-procedure admissions (OR 0.23, p = 0.003). Therefore, when using paravertebral blocks, bilateral blocks are superior to unilateral blocks, as demonstrated by decreased rates of hospital admission and reduced use of systemic neuropathic pain medication. Additionally, reducing post-procedural MME may reduce the rate of admission to the hospital.

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.

Percutaneous Management of Malignant Biliary Obstruction

Malignancy resulting in impaired biliary drainage includes a number of diagnoses familiar to the interventional radiologist. Adequate drainage of such a system can significantly improve patient quality of life, and can facilitate the further treatment options and care of such patients. In the setting of prior instrumentation, cholangitis can present as an urgent indication for drainage. Current initial interventional management of malignant biliary duct obstruction frequently includes endoscopic or percutaneous intervention, with local practices and preprocedural imaging guiding interventional approaches and subsequent management. This article addresses the indications for percutaneous drainage, technical considerations in performing such drainage, and specific techniques useful in attempting to achieve clinical end points in patients with malignant biliary duct obstruction.

Paravertebral Block: An Improved Method of Pain Control in Percutaneous Transhepatic Biliary Drainage

BACKGROUND AND PURPOSE

Percutaneous transhepatic biliary drainage remains a painful procedure in many cases despite the routine use of large amounts of intravenous sedation. We present a feasibility study of thoracic paravertebral blocks in an effort to reduce pain during and following the procedure and reduce requirements for intravenous sedation.

METHODS

Ten consecutive patients undergoing biliary drainage procedures received fluoroscopically guided paravertebral blocks and then had supplemental intravenous sedation as required to maintain patient comfort. Levels T8-T9 and T9-T10 on the right were targeted with 10-20 ml of 0.5% bupivacaine. Sedation requirements and pain levels were recorded.

RESULTS

Ten biliary drainage procedures in 8 patients were performed for malignancy in 8 cases and for stones in 2. The mean midazolam use was 1.13 mg i.v., and the mean fentanyl requirement was 60.0 microg i.v. in the block patients. Two episodes of hypotension, which responded promptly to volume replacement, may have been related to the block. No serious complications were encountered. The mean pain score when traversing the chest wall, liver capsule, and upon entering the bile ducts was 0.1 on a scale of 0 to 10, with 1 patient reporting a pain level of 1 and 9 reporting 0. The mean peak pain score, encountered when manipulating at the common bile duct level or when addressing stones there, was 5.4 and ranged from 0 to 10.

CONCLUSIONS

Thoracic paravertebral block with intravenous sedation supplementation appears to be a feasible method of pain control during biliary interventions.

Thoracic Paravertebral Block for Percutaneous Transhepatic Biliary Drainage

Percutaneous transhepatic biliary drainage is a painful procedure most commonly performed after intravenous sedation. Despite systemic opiates and benzodiazepines, most patients experience significant pain during the procedure and in the recovery period. Paravertebral blocks allow the spinal nerve roots and sympathetic chain in the paravertebral space to be anesthetized, and their role in providing analgesia for thoracic and upper abdominal surgical procedures is well-established. Herein a case is described in which thoracic paravertebral blockade dramatically reduced standard intra- and postprocedural analgesic needs and provided superior pain control.

Sedations and analgesia in patients undergoing percutaneous transhepatic biliary drainage

AIM

To present our experience using intravenous sedoanalgesia for percutaneous biliary drainage.

MATERIALS AND METHODS

This study comprised 100 patients, all of whom were continuously monitored [electrocardiogram (ECG), blood pressure, pulse oxymetry] and received an initial dose of 2mg midazolam followed by 0.02 mg fentanyl. Before every anticipated painful procedure, a maintenance dose of 0.01 mg fentanyl was administered. If the procedure continued and the patient became aware, another 1mg midazolam was given. This was repeated if patients felt pain. A total dose of 0.08 mg fentanyl and 7 mg midazolam was never exceeded. Immediately after the procedure, the nurse was asked to evaluate patients' pain score. The patients were asked 3h later to complete a visual 10-degree pain score scale.

RESULTS

The average dose of fentanyl and midazolam was 0.042 mg (0.03-0.08 mg) and 4.28 mg (2-7 mg), respectively. Only one patient recorded the procedure as painful. The scores given by the attending nurse (1-7 points, mean 2.9) correlated well with those given by the patients (1-6 points, mean 2.72). No complications were noted.

CONCLUSION

According to our experience, interventional radiologists practising biliary procedures can administer low doses of midazolam and minimize the doses of fentanyl, without loss of adequate sedation and analgesia.

Diagnosis and treatment of postoperative chyle leakage via percutaneous transabdominal catheterization of the cisterna chyli: a preliminary study

PURPOSE

To assess the feasibility of percutaneous transabdominal puncture and catheterization of the cisterna chyli or lymphatic ducts (PTCLD) in patients with postoperative chyloperitoneum and chylothorax, and to identify and possibly embolize the chylous fistula.

MATERIALS AND METHODS

Five patients had postoperative uncontrolled chyle fistulas. Two patients with chylothorax had thoracic duct (TD) ligation after esophagectomy and neck surgery. The other three patients had chylous ascites after surgery of the pancreas, the aorta, and the esophagus, respectively. After lymphographic opacification, the cisterna chyli (CC) or retroperitoneal lymph ducts were punctured transabdominally with a 21-gauge needle and catheterized with a 3-F catheter to reach the TD if possible. Microcoils were used to embolize a TD laceration.

RESULTS

Lymph ducts as small as 2-3 mm were catheterized successfully in three patients. The TD was catheterized in two patients; one TD fistula was embolized with cure of chylothorax. In one patient with a surgically tied TD, duct occlusion was confirmed despite continued pleural effusion. Three fistulas, not seen with lymphography, were identified in two of three chylous ascites and one chylothorax. There was no morbidity. As a result of this procedure, four of five patients did not require repeated operation.

CONCLUSIONS

PTCLD in the study of chyle fistulas was feasible and safe in the management of five patients and clinically useful in four patients; transabdominal catheter lymphography with aqueous contrast medium is more sensitive than pedal lymphography. Further evaluation is necessary.