Thoracic Paravertebral Block for Percutaneous Transhepatic 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.

Optimized nerve block techniques while performing percutaneous hepatic ablation:

Percutaneous image guided thermal ablation has become a cornerstone of therapy for patients with oligometastatic disease and primary liver malignancies. Evolving from percutaneous ethanol injection (PEI), thermal ablation utilizing radiofrequency ablation (RFA) and microwave ablation (MWA) have become the standard approach in the treatment of isolated lesions that fit within the size criteria for curative intent therapy (typically 3-4cm). With the evolution of more intense thermal ablation, such as MWA, the dramatic increase in both the size of ablation zone and intensity of heat generation have extended the limits of this technique. As a result of these innovations, intra-procedural and post-procedural pain have also significantly increased, requiring either higher levels of intravenous sedation or, in some institutions, general anesthesia. In addition to the increase in therapeutic intensity, the use of intravenous sedation during aggressive ablation procedures carries the risk of over-sedation when the noxious insult (i.e. the ablation) is removed, adding further difficulty to post-procedural recovery and management. Furthermore, high subdiaphragmatic lesions become challenging in this setting due to issues relating to sedation and compliance with breath hold/breathing instructions. Although general anesthesia may mitigate these complications, the added resources associated with providing general anesthesia during ablation is not cost effective and may result in substantial delays in treatment. The reduction of Aerosol Generating Medical Procedures (AGMP), such as intubation due to the COVID-19 Pandemic, must also be taken into consideration. Due to the potential increased risk of infection transmission, alternatives to general anesthesia should be considered when safe and possible. Upper abdominal regional nerve block techniques have been used to manage pain related to trauma, surgery, and cancer; however, blocks of this nature are not well described in the interventional radiology literature. The McGill University group has developed experience in using such blocks as splanchnic, celiac and hepatic hilar nerve blocks to provide peri-procedural pain control [1]. Since incorporating these techniques (along with hydrodissection with tumescent anesthesia), we have also observed in our high volume ablation center a dramatic decrease in the amount of sedatives administered during the procedure, a decrease in patient discomfort during localization and ablation, as well as decreased pain post-procedure. Faster time to discharge and overall reduction in room procedural time serve as added benefits. The purpose of this publication is to outline and illustrate the practical application and use of nerve block/regional anesthesia techniques with respect to percutaneous hepatic thermal ablation.

Bilateral thoracic paravertebral nerve blocks for placement of percutaneous radiologic gastrostomy in patients with amyotrophic lateral sclerosis: a case series

BACKGROUND AND AIMS

To assess the efficacy of bilateral thoracic paravertebral nerve blocks (PVB) in providing procedural anesthesia and post-procedural analgesia for placement of percutaneous radiologic gastrostomy tubes (PRG) in patients with amyotrophic lateral sclerosis (ALS).

METHODS

We prospectively observed 10 patients with ALS scheduled for PRG placement that had bilateral thoracic PVBs at thoracic 7, 8, and 9 levels with administration of a mixture of 3 mL of 1% ropivacaine, 0.5 mg/mL dexamethasone, and 5 μg/mL epinephrine at each level. The success of the block was assessed after 10 minutes. PRG placement was done in the interventional radiology suite without sedation. All patients were followed up via phone 24 hours after the procedure.

RESULTS

All 10 patients had successful placement of PRG with PVBs as the primary anesthetic. Segmental anesthesia over the surgical site in all cases was successful with first attempt of the blocks. Three patients had significant hypotension after the block, requiring boluses of vasopressors and intravenous fluids. All patients reported high levels of satisfaction and sleep quality on the night of the procedure.

CONCLUSIONS

Bilateral thoracic PVBs provided satisfactory procedural anesthesia and post-procedural analgesia, and thus, seem promising as a safe alternative to sedation in ALS patients having PRG placement.

Continuous right thoracic paravertebral block following bolus initiation reduced postoperative pain after right-lobe hepatectomy: a randomized, double-blind, placebo-controlled trial

Background and Objectives

We hypothesized that continuous right thoracic paravertebral block, following bolus initiation, decreases opioid consumption after right-lobe hepatectomy in patients receiving patient-controlled intravenous analgesia with sufentanil.

Methods

Patients undergoing right-lobe hepatectomy with a right thoracic paravertebral catheter placed at T7 30 minutes before surgery were randomly assigned to receive through this catheter either a 10-mL bolus of 0.2% ropivacaine before emergence, followed by a continuous infusion of 6 mL/h for 24 hours (PVB group), or saline at the same scheme of administration (control group). All patients were started on patient-controlled intravenous analgesia with sufentanil in the postanesthesia care unit. The primary outcome measure was total sufentanil consumption during the first 24 postoperative hours. P = 0.05 was considered as significant. For the multiple comparisons of data at 5 different time points, the P value for the 0.05 level of significance was adjusted to 0.01.

Results

Sixty-six patients were assessed for eligibility, and a PVB catheter was successfully placed for 48 patients. Data were analyzed on 22 patients in group PVB and 22 patients in the control group. The cumulative sufentanil consumption in the PVB group (54.3 ± 12.1 μg) at 24 postoperative hours was more than 20% less than that of the control group (68.1 ± 9.9 μg) (P < 0.001). There was also a significant difference in pain scores (numerical rating scale) between groups, where the PVB group had lower scores than did the control group at rest and with coughing for the first 24 hours (P < 0.001).

Conclusions

Continuous right thoracic paravertebral block, following bolus initiation, has an opioid-sparing effect on sufentanil patient-controlled intravenous analgesia for right-lobe hepatectomy patients and reduces numerical rating scale pain scores at rest and with coughing in the first 24 postoperative hours.

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.

Thoracic paravertebral anesthesia for percutaneous radiofrequency ablation of hepatic tumors

STUDY OBJECTIVE

To present our preliminary experience using a thoracic paravertebral block (TPVB) as the sole anesthetic in percutaneous hepatic radiofrequency ablation (RFA).

DESIGN

Retrospective case series of 12 ASA physical status 1, 2, and 3 patients of average risk scheduled for RFA.

SETTING

University medical center.

MEASUREMENTS

The first 12 procedures performed using TPVB were analyzed to evaluate the efficacy and safety of this anesthetic technique. Data collected included patients' characteristics, procedure, pain referred during paravertebral punctures, and RFA (verbal numerical scale; VNS). Anesthesia and medical records also were reviewed for any major complications that occurred during or after the RFA.

MAIN RESULTS

Ten of the 12 patients presented for hepatocellular carcinoma; the other two patients had melanoma metastasis. Nine patients were ASA physical status 1 or 2; the other three patients were ASA physical status 3. Nine had liver cirrhosis. All patients had normal coagulation profiles. The TPVBs were performed in a median time of 6.5 (4-15) minutes. Onset of sensory loss to pinprick test occurred approximately 15 to 20 minutes after the injections. No evidence of bilateral blockade was seen in any patient. In most cases, the extent of anesthesia ranged from T6 to T11 or T12. In one patient (no. 2), the stimulating needle elicited no sensory or motor response at the T7 level; the local anesthetic was then injected one cm beyond the transverse process. All patients were very pleased with their anesthetic care; all were discharged from the hospital with no procedure-related complications.

CONCLUSION

The use of thoracic paravertebral block as the sole anesthetic for RFA of liver produced satisfactory unilateral anesthesia and minor adverse events.

Paravertebral blocks

Paravertebral blocks have been demonstrated to represent an interesting alternative to epidural, especially for the management of perioperative and trauma pain. Initially performed mostly as single-shot blocks for breast surgery, thoracotomy, and hernia repairs in adults and children, presently these blocks are also used for placement of a paravertebral catheter, either unilateral or bilateral. Although complications associated with the performance of these blocks are infrequent, the use of ultrasound-guided approaches, which allow performing the block under direct vision, is becoming the standard in most groups performing these blocks routinely.

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.