EUS-Guided Versus Percutaneous Celiac Neurolysis for the Management of Intractable Pain Due to Unresectable Pancreatic Cancer: A Randomized Clinical Trial

Endoscopic Ultrasound-Guided Pain Management

The diagnosis and management of pancreatic cancer has become a standard role for the endoscopic oncologist. Pancreatic cancer can produce disabling abdominal pain, and the medical management of this pain is often challenging. Endoscopic ultrasound-guided celiac plexus neurolysis and celiac ganglia neurolysis serve as an alternative or adjunct for pain control in these patients. There remains a great deal of practice variability with regard to techniques and approaches. This article summarizes the latest scientific evidence and highlights contemporary best practice advice for these procedures.

The Role of Endoscopy in the Palliation of Pancreatico-Biliary Cancers: Biliary Drainage, Management of Gastrointestinal Obstruction, and Role in Relief of Oncologic Pain

Therapeutic endoscopy permits many and various treatments for cancer palliation in patients with bilio-pancreatic cancers, enabling different options, supporting patients during their route to oncologic treatments, and trying to improve their quality of life. Therefore, both endoscopic and endoscopic ultrasound (EUS)-guided techniques are performed in this scenario. We performed a literature review focusing on the role of endoscopy in the palliation of those advanced pancreatic and biliary cancers developing malignant biliary obstruction (MBO), gastric outlet obstruction (GOO), and pain unresponsive to medical therapies. Therefore, we explored and focused on the clinical outcomes of endoscopic procedures in this scenario. In fact, the endoscopic treatment is based on achieving biliary drainage in the case of MBO through endoscopic retrograde cholangiopancreatography (ERCP) or EUS-guided biliary drainage (EUS-BD), while GOO is endoscopically treated through the deployment of an enteral stent or the creation of EUS-guided gastro-entero-anastomosis (EUS-GEA). Furthermore, untreatable chronic abdominal pain is a major issue in patients unresponsive to high doses of painkillers, so EUS-guided celiac plexus neurolysis (CPN) or celiac ganglia neurolysis (CGN) helps to reduce dosage and have better pain control. Therefore, therapeutic endoscopy in the palliative setting is an effective and safe approach for managing most of the clinical manifestations of advanced biliopancreatic tumors.

Efficacy of Endoscopic Ultrasound-guided Celiac Plexus Neurolysis for Abdominal Pain in Patients With Unresectable Pancreatic Cancer: Network Meta-analysis of Randomized Controlled Trials

GOALS

We conducted a systematic review and network meta-analysis to investigate the effect of endoscopic ultrasound-guided celiac plexus neurolysis added to medical management (EUS-CPN+MM) compared with MM, percutaneous CPN (P-CPN)+MM, or intraoperative CPN (I-CPN)+MM for abdominal pain associated with unresectable pancreatic cancer.

BACKGROUND

Many approaches to CPN have been proposed since 1919. EUS-CPN, which is less invasive and safer than traditional procedures, has been preferred recently, but the superiority of EUS-CPN+MM has not been fully investigated.

STUDY

We performed searches of PubMed, Web of Science, and the Cochrane Central Register of Controlled Trials for randomized controlled trials (RCTs) on March 16, 2021. We conducted the network meta-analysis using a frequentist weighted least-squares approach. We used a random-effects model to synthesize the primary outcome, defined as the mean difference between treatment groups in standardized pain intensity scores at 4 and 12 weeks.

RESULTS

We selected 10 RCTs involving 662 individuals. At 4 weeks, the estimated mean difference between the EUS-CPN+MM and MM groups was -1.30 (95% CI: -2.19 to -0.41) in favor of EUS-CPN+MM, and that between the EUS-CPN+MM and P-CPN+MM groups was -0.88 (95% CI: -1.82 to 0.06). At 12 weeks, the estimated mean difference between the EUS-CPN+MM and MM groups was -2.58 (95% CI: -3.68 to -1.48), and that between the EUS-CPN+MM and P-CPN+MM groups was -2.44 (95% CI: -4.03 to -0.84), both in favor of EUS-CPN+MM.

CONCLUSIONS

The combination of EUS-CPN+MM was effective at 4 and 12 weeks, although the risk of bias in synthesized studies was generally high, necessitating careful interpretation.

EUS-guided celiac plexus neurolysis for pancreas cancer - Finally established or still under review?

Patients with pancreas cancer must deal frequently with intractable and refractory pain. Endoscopic ultrasound guided-celiac plexus neurolysis (EUS-CPN) has been the most studied and used therapeutic technique aimed to destroy the pain fibres that allow the pancreas to communicate with the central nervous system. A neurolytic agent, most commonly ethanol, is optimally spread around the celiac axis in order to reduce pain and mitigate narcotic requirements. This can be performed early to prevent the spiral of pain and medication use, or more historically as salvage therapy. Different techniques to best administer the ethanol for effective EUS-CPN are still being debated. New EUS-guided injection techniques with radiofrequency, radioactive, and/or chemotherapeutic agents need more study.

PALLIATIVE TREATMENT OF INTRACTABLE CANCER PAIN

In 10% to 30% cancer-pain cases standard analgesic therapy fails to provide effective pain relief. Interventional techniques, such as peripheral nerve blocks, neuraxial analgesia along with neurolytic blocks may be used for such refractory pain. Peripheral nerve blocks can be used when pain occurs in the territory of one or more peripheral nerves, but rarely as main therapy. Neuraxial analgesia is a valid option for progressive cancer pain, and healthcare possibilities and costs call into question the utility of intrathecal infusion pumps. Neurolysis is the targeted destruction of a nerve or nerve plexus, using chemicals, radiofrequency ablation (RFA), cryoablation, and neurosurgical procedures; however, it rarely completely eliminates pain because patients frequently experience coexisting somatic and neuropathic pain as well. Complex conditions of palliative patients along with limited high-quality randomized controlled trials limit the use of interventional procedures. Even so, some cancer patients benefit from interventional procedures to achieve pain alleviation and consequently improve quality of life.

Systematic review and meta-analysis of celiac plexus neurolysis for abdominal pain associated with unresectable pancreatic cancer

INTRODUCTION

Celiac plexus neurolysis (CPN) has been developed as adjunctive therapy to medical management (MM) of abdominal pain associated with unresectable pancreatic cancer. We aimed to conduct a systematic review and meta-analysis to obtain updated and more accurate evidence on the efficacy of additional types of CPN, including endoscopic ultrasound-guided CPN (EUS-CPN).

METHODS

On March 16, 2021, we performed searches of PubMed, Web of Science, and CENTRAL for original randomized controlled trials (RCTs). We defined the primary outcome as a standardized pain intensity score with a range of 0-10, and evaluated the mean difference between the CPN + MM and MM groups at 4, 8, and 12 weeks after the initiation of treatment. We used a random-effects model to synthesize the mean differences across RCTs.

RESULTS

We selected 10 RCTs involving 646 individuals. The synthesized mean difference in the pain intensity score between the CPN + MM and MM groups was -0.58 (95% confidence interval [CI]: -1.09 to -0.07) (p = 0.034) in favor of CPN + MM at 4 weeks, -0.46 (95%CI: -1.00 to 0.08) (p = 0.081) at 8 weeks, and - 1.35 (95%CI: -3.61 to 0.92) (p = 0.17) at 12 weeks.

CONCLUSIONS

This updated meta-analysis of CPN demonstrates its efficacy for managing abdominal pain at 4 weeks. Although there are various limitations, when abdominal pain in patients with unresectable pancreatic cancer is poorly controlled with MM alone, CPN should be an option even if the duration of effect is short-lived, taking into account the absence of serious adverse events.

Factors associated with successful response to neurolytic celiac plexus block in patients with upper abdominal cancer-related pain: a retrospective study

Background

Prior studies have reported that 40%-90% of the patients with celiac plexus-mediated visceral pain benefit from the neurolytic celiac plexus block (NCPB), but the predictive factors of response to NCPB have not been evaluated extensively. This study aimed to identify the factors associated with the immediate analgesic effectiveness of NCPB in patients with intractable upper abdominal cancer-related pain.

Methods

A retrospective review was performed of 513 patients who underwent NCPB for upper abdominal cancer-related pain. Response to the procedure was defined as (1) a decrease of ≥ 50% or ≥ 4 points on the numerical rating scale (NRS) in pain intensity from the baseline without an increase in opioid requirement, or (2) a decrease of ≥ 30% or ≥ 2 points on the NRS from the baseline with simultaneously reduced opioid consumption after NCPB. Logistic regression analysis was performed to determine the factors associated with successful responses to NCPB.

Results

Among the 513 patients included in the analysis, 255 (49.8%) and 258 (50.2%) patients were in the non-responder and responder group after NCPB, respectively. Multivariable logistic regression analysis showed that diabetes (odds ratio [OR] = 0.644, P = 0.035), history of upper abdominal surgery (OR = 0.691, P = 0.040), and celiac metastasis (OR = 1.496, P = 0.039) were the independent factors associated with response to NCPB.

Conclusions

Celiac plexus metastases, absence of diabetes, and absence of prior upper abdominal surgery may be independently associated with better response to NCPB for upper abdominal cancer-related pain.

Interventional endoscopic ultrasound

PURPOSE OF REVIEW

To update on recent advances in interventional endoscopic ultrasound (INVEUS) techniques.

RECENT FINDINGS

The introduction of linear echoendoscopes with larger instrument channels and the combined development of new tools and devices have enabled various new applications of minimally invasive endoscopic ultrasound (EUS)-guided transluminal interventions of the pancreas, biliary system and peri-gastrointestinal structures. In this review, EUS-guided interventions are discussed and evaluated: drainage of peripancreatic fluid collections, access and drainage of bile ducts, gallbladder and pancreatic duct, treatment of gastrointestinal haemorrhage, coeliac plexus block and coeliac plexus neurolysis, fiducial placement, solid and cystic tumour ablation, drug delivery and brachytherapy, gastroenterostomy, angiotherapy and other EUS-guided applications. The EUS-guided interventions are classified based on the available evidence as established or experimental, standardized or nonstandardized procedures in common or rare diseases with well or little known complications and their established or nonestablished treatment.

SUMMARY

Some EUS-guided interventions have sparse published evidence with only single-centre studies, case series or individual case reports, others like drainage of peripancreatic fluid collections have become widely accepted practice. INVEUS has been accepted as an alternative to several surgical approaches, EUS-guided techniques result in faster recovery times, shorter hospital stay and lower costs.

The American Society of Pain and Neuroscience (ASPN) Best Practices and Guidelines for the Interventional Management of Cancer-Associated Pain

Moderate to severe pain occurs in many cancer patients during their clinical course and may stem from the primary pathology, metastasis, or as treatment side effects. Uncontrolled pain using conservative medical therapy can often lead to patient distress, loss of productivity, shorter life expectancy, longer hospital stays, and increase in healthcare utilization. Various publications shed light on strategies for conservative medical management for cancer pain and a few international publications have reviewed limited interventional data. Our multi-institutional working group was assembled to review and highlight the body of evidence that exists for opioid utilization for cancer pain, adjunct medication such as ketamine and methadone and interventional therapies. We discuss neurolysis via injections, neuromodulation including targeted drug delivery and spinal cord stimulation, vertebral tumor ablation and augmentation, radiotherapy and surgical techniques. In the United States, there is a significant variance in the interventional treatment of cancer pain based on fellowship training. As a first of its kind, this best practices and interventional guideline will offer evidenced-based recommendations for reducing pain and suffering associated with malignancy.

Neuropathic Pain in Pancreatic Cancer: An Update of the Last Five Years

Pain is the main symptom of pancreatic cancer (pancreatic ductal adenocarcinoma, PDAC). Pain in pancreatic cancer may be visceral, somatic or neuropathic in origin. Pain is produced by tissue damage, inflammation, ductal obstruction and infiltration. Visceral nociceptive signals caused by damage to the upper abdominal viscera are carried along sympathetic fibers, which travel to the celiac plexus nerves and ganglia, which are found at the T12-L2 vertebral levels, anterolateral to the aorta near the celiac trunk. From here, the signals are transmitted through the splanchnic nerves to the T5-T12 dorsal root ganglia and then on to the higher centers of the central nervous system. Somatic and neuropathic pain may arise from tumor extension into the surrounding peritoneum, retroperitoneum and bones and, in the latter case, into the nerves, such as the lumbosacral plexus. It should also be noted that other types of pain might arise because of therapeutic interventions, such as post-chemoradiation syndromes, which cause mucositis and enteritis. Management with non-steroidal anti-inflammatory agents and narcotics was the mainstay of therapy. In recent years, celiac plexus blocks and neurolysis, as well as intrathecal therapies have been used to control severe pain, at times resulting in a decreased need for drugs, avoiding their unwanted side effects. Pain may impair the patient’s quality of life, negatively affecting patient outcome and resulting in increased psychological stress. Even after recognizing the negative effect of cancer pain on patient overall health, studies have shown that cancer pain is still undertreated. This review focuses on neuropathic pain, which is difficult to handle; thus, the most recent literature was reviewed in order to diagnose neuropathic pain and its management.

EUS-guided celiac plexus neurolysis for pain in pancreatic cancer patients - a meta-analysis and systematic review

Background: Endoscopic ultrasound guided celiac plexus neurolysis (EUS- CPN) has been reported to be an effective way to help with pain in pancreatic cancer patient. The aim of our updated meta-analysis is to assess the efficacy of pain relief in patients with pancreatic cancer who underwent EUS guided neurolysis.

Methods:

Pooled proportions were calculated using both Mantel-Haenszel method (fixed effects model) and DerSimonian Laird method (random effects model). The heterogeneity among studies was tested using Cochran’s Q test based upon inverse variance weights. 

Results: Initial search identified 176 reference articles, of which 34 were selected and reviewed in detail. Sixteen studies that met the inclusion criteria were included in this analysis. The mean age of patients undergoing neurolysis was 56.31 ± 19.72 years. Number of males, N = 563 (57.4%), was higher than the number of females, N = 417 (42.5%). The pooled proportion of patients who showed pain relief with EUS-guided neurolysis was 71% (95% CI = 68–74). Bias calculated using Begg–Mazumdar was not significant (p = 0.8). In a subgroup analysis, when comparing the central and bilateral techniques, the pooled proportion of patients with pain relief was 66% (95% CI = 61–71) and 57% (95% CI = 48–67), respectively.

Conclusions: Our results show that EUS guided CPN could provide relief in as much as 70% of patients with central neurolysis technique having some edge over peripheral neurolysis. Further larger scale randomized controlled trials may further help to elaborate the efficacy of central vs peripheral neurolysis.