Assessment of celiac plexus block and neurolysis outcomes and technique in the management of refractory visceral cancer pain

Role of interventional radiology in pain management in oncology patients

This article reviews the current evidence of interventional radiology procedures for patients suffering with debilitating cancer pain, refractory to conventional therapies. Cancer pain is notoriously difficult to treat. Up to 90% of cancer patients experience pain with 56-82% of cancer pain controlled inadequately. Cancer pain influences a patient's ability to perform normal daily activities, causes higher risk of depression, and reduces quality of life. Pain-free status has been universally voted as a "good death". Alternative minimally invasive options include nerve blocks, neurolysis, bone ablation, spine and peripheral musculoskeletal augmentation techniques, embolisation, and cordotomy with evidence highlighting improved pain control, reduced analgesic requirements, and improved quality of life. Unfortunately, awareness and availability of these procedures is limited, potentially leaving patients suffering during their remaining life. The purpose of this review is to describe the basic concepts of interventional radiology techniques for pain palliation in oncology patients. In addition, emphasis will be given upon the need for an individually tailored approach aiming to augment efficacy and safety.

Role of Endoscopy in Management of Upper Gastrointestinal Cancers

Upper gastrointestinal (GI) malignancy is a leading cause of cancer-related morbidity and mortality. Upper endoscopy has an established role in diagnosing and staging upper GI cancers, screening for pre-malignant lesions, and providing palliation in cases of advanced malignancy. New advances in endoscopic techniques and technology have improved diagnostic accuracy and increased the therapeutic potential of upper endoscopy. We aim to describe the different types of endoscopic technology used in cancer diagnosis, summarize the current guidelines for endoscopic diagnosis and treatment of malignant and pre-malignant lesions, and explore new potential roles for endoscopy in cancer therapy.

Computed tomography-guided single celiac plexus neurolysis analgesic efficacy and safety: a systematic review and meta-analysis

PURPOSE

To perform a systematic review and meta-analysis of published studies to evaluate the analgesic efficacy and safety of computed tomography (CT)-guided single celiac plexus neurolysis (CPN) with the injection of a neurolytic agent into the celiac plexus in one session (CT-guided single CPN).

METHODS

PubMed, the Cochrane Library, and Ichushi-Web were searched for English or Japanese articles published up to February 2022, which reported findings about patients who underwent CT-guided single CPN. The outcome measures assessed in the systematic review and meta-analysis were the pain measurement scales from 0 to 10 before and after the intervention and the rate of minor and major complications.

RESULTS

The pooled pain measurement scales at pre-intervention and 1- or 2-, 7-, 30-, 60-, 90-, and 180-day post-intervention was 6.72 (95% confidence interval [CI], 4.77-9.46, I² = 98%), 2.31 (95% CI 2.31-4.44, I² = 92%), 2.84 (95% CI 1.39-5.79, I² = 95%), 3.36 (95% CI 1.66-6.77, I² = 98%), 3.19 (95% CI 1.44-7.08, I² = 59%), 3.87 (95% CI 1.88-7.97, I² = 0%), and 3.40 (95% CI 3.02-3.83, I² = not applicable), respectively. The pooled minor complication rates of diarrhea, hypotension, nausea or vomiting, and pain associated with the procedure were 18% (95% CI 8-37%, I² = 45%), 16% (95% CI 2-58%, I² = 76%), 6% (95% CI 2-16%, I² = 1%), and 7% (95% CI 2-21%, I² = 17%), respectively. There was no major complication in the included studies.

CONCLUSION

CT-guided single CPN can be performed safely and provides immediate analgesic efficacy although the amount of heterogeneity is characterized as large. Further investigation of its long-term analgesic efficacy is required.

CT-Guided Coeliac Plexus Neurolysis in Patients with Intra-Abdominal Malignancy: A Retrospective Evaluation of 52 Palliative In-Patients

INTRODUCTION

Prevalence rates of chronic abdominal pain (CAP) and breakthrough cancer pain (BTcP) are high in patients with intra-abdominal malignancies. As part of a multimodal approach, CT-guided coeliac plexus blockade (CPB) and CT-guided coeliac plexus neurolysis (CPN) are commonly used pain management strategies. The aim of this study was to evaluate pain outcomes among patients with intra-abdominal malignancies who underwent CPB and/or CPN.

METHODS

Patients with intra-abdominal malignancies who underwent CPB and/or CPN for pain control at the general hospital Klagenfurt am Wörthersee from 2010 to 2019 were enrolled.

RESULTS

A total of 84 procedures (24 CPB and 60 CPN) were performed on 52 patients; 62% of these patients had pancreatic cancer. CPN led to significant pain reduction and decreased BTcP intensity. Patients receiving repeated CPN showed higher individual pain reduction. Higher pre-procedural pain intensity was correlated with higher pain reduction. No difference in pain reduction in patients receiving a diagnostic CPB prior to CPN compared to patients without a diagnostic CPB was found. Higher pain reduction after CPN led to longer-lasting pain relief. The time frame from diagnosis to CPN was 472 (± 416) days. Patients experienced a mean duration of pain prior to CPN of 330 (± 53) days. The time frame from diagnosis to CPN was shorter in patients with pancreatic cancer compared to other intra-abdominal malignancies. In 58% of patients pain medication was stable or was reduced after CPN; 16% of patients complained about pain during the procedure; no major complications occurred. There was no correlation between median survival after CPN and pain outcomes.

CONCLUSIONS

In patients with intra-abdominal malignancy-related CAP, CPN is a safe and effective procedure which can provide long-lasting significant relief of background pain and BTcP. As part of a multimodal approach, CPN should be considered as an earlier option for pain management in these patients.

Consensus practice guidelines on interventions for cervical spine (facet) joint pain from a multispecialty international working group

BACKGROUND

The past two decades have witnessed a surge in the use of cervical spine joint procedures including joint injections, nerve blocks and radiofrequency ablation to treat chronic neck pain, yet many aspects of the procedures remain controversial.

METHODS

In August 2020, the American Society of Regional Anesthesia and Pain Medicine and the American Academy of Pain Medicine approved and charged the Cervical Joint Working Group to develop neck pain guidelines. Eighteen stakeholder societies were identified, and formal request-for-participation and member nomination letters were sent to those organizations. Participating entities selected panel members and an ad hoc steering committee selected preliminary questions, which were then revised by the full committee. Each question was assigned to a module composed of 4-5 members, who worked with the Subcommittee Lead and the Committee Chairs on preliminary versions, which were sent to the full committee after revisions. We used a modified Delphi method whereby the questions were sent to the committee en bloc and comments were returned in a non-blinded fashion to the Chairs, who incorporated the comments and sent out revised versions until consensus was reached. Before commencing, it was agreed that a recommendation would be noted with >50% agreement among committee members, but a consensus recommendation would require ≥75% agreement.

RESULTS

Twenty questions were selected, with 100% consensus achieved in committee on 17 topics. Among participating organizations, 14 of 15 that voted approved or supported the guidelines en bloc, with 14 questions being approved with no dissensions or abstentions. Specific questions addressed included the value of clinical presentation and imaging in selecting patients for procedures, whether conservative treatment should be used before injections, whether imaging is necessary for blocks, diagnostic and prognostic value of medial branch blocks and intra-articular joint injections, the effects of sedation and injectate volume on validity, whether facet blocks have therapeutic value, what the ideal cut-off value is for designating a block as positive, how many blocks should be performed before radiofrequency ablation, the orientation of electrodes, whether larger lesions translate into higher success rates, whether stimulation should be used before radiofrequency ablation, how best to mitigate complication risks, if different standards should be applied to clinical practice and trials, and the indications for repeating radiofrequency ablation.

CONCLUSIONS

Cervical medial branch radiofrequency ablation may provide benefit to well-selected individuals, with medial branch blocks being more predictive than intra-articular injections. More stringent selection criteria are likely to improve denervation outcomes, but at the expense of false-negatives (ie, lower overall success rate). Clinical trials should be tailored based on objectives, and selection criteria for some may be more stringent than what is ideal in clinical practice.

Consensus practice guidelines on interventions for cervical spine (facet) joint pain from a multispecialty international working group

Background

The past two decades have witnessed a surge in the use of cervical spine joint procedures including joint injections, nerve blocks and radiofrequency ablation to treat chronic neck pain, yet many aspects of the procedures remain controversial.

Methods

In August 2020, the American Society of Regional Anesthesia and Pain Medicine and the American Academy of Pain Medicine approved and charged the Cervical Joint Working Group to develop neck pain guidelines. Eighteen stakeholder societies were identified, and formal request-for-participation and member nomination letters were sent to those organizations. Participating entities selected panel members and an ad hoc steering committee selected preliminary questions, which were then revised by the full committee. Each question was assigned to a module composed of 4–5 members, who worked with the Subcommittee Lead and the Committee Chairs on preliminary versions, which were sent to the full committee after revisions. We used a modified Delphi method whereby the questions were sent to the committee en bloc and comments were returned in a non-blinded fashion to the Chairs, who incorporated the comments and sent out revised versions until consensus was reached. Before commencing, it was agreed that a recommendation would be noted with >50% agreement among committee members, but a consensus recommendation would require ≥75% agreement.

Results

Twenty questions were selected, with 100% consensus achieved in committee on 17 topics. Among participating organizations, 14 of 15 that voted approved or supported the guidelines en bloc, with 14 questions being approved with no dissensions or abstentions. Specific questions addressed included the value of clinical presentation and imaging in selecting patients for procedures, whether conservative treatment should be used before injections, whether imaging is necessary for blocks, diagnostic and prognostic value of medial branch blocks and intra-articular joint injections, the effects of sedation and injectate volume on validity, whether facet blocks have therapeutic value, what the ideal cut-off value is for designating a block as positive, how many blocks should be performed before radiofrequency ablation, the orientation of electrodes, whether larger lesions translate into higher success rates, whether stimulation should be used before radiofrequency ablation, how best to mitigate complication risks, if different standards should be applied to clinical practice and trials, and the indications for repeating radiofrequency ablation.

Conclusions

Cervical medial branch radiofrequency ablation may provide benefit to well-selected individuals, with medial branch blocks being more predictive than intra-articular injections. More stringent selection criteria are likely to improve denervation outcomes, but at the expense of false-negatives (ie, lower overall success rate). Clinical trials should be tailored based on objectives, and selection criteria for some may be more stringent than what is ideal in clinical practice.

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.

Consensus practice guidelines on interventions for lumbar facet joint pain from a multispecialty, international working group

BACKGROUND

The past two decades have witnessed a surge in the use of lumbar facet blocks and radiofrequency ablation (RFA) to treat low back pain (LBP), yet nearly all aspects of the procedures remain controversial.

METHODS

After approval by the Board of Directors of the American Society of Regional Anesthesia and Pain Medicine, letters were sent to a dozen pain societies, as well as representatives from the US Departments of Veterans Affairs and Defense. A steering committee was convened to select preliminary questions, which were revised by the full committee. Questions were assigned to 4-5 person modules, who worked with the Subcommittee Lead and Committee Chair on preliminary versions, which were sent to the full committee. We used a modified Delphi method, whereby the questions were sent to the committee en bloc and comments were returned in a non-blinded fashion to the Chair, who incorporated the comments and sent out revised versions until consensus was reached.

RESULTS

17 questions were selected for guideline development, with 100% consensus achieved by committee members on all topics. All societies except for one approved every recommendation, with one society dissenting on two questions (number of blocks and cut-off for a positive block before RFA), but approving the document. Specific questions that were addressed included the value of history and physical examination in selecting patients for blocks, the value of imaging in patient selection, whether conservative treatment should be used before injections, whether imaging is necessary for block performance, the diagnostic and prognostic value of medial branch blocks (MBB) and intra-articular (IA) injections, the effects of sedation and injectate volume on validity, whether facet blocks have therapeutic value, what the ideal cut-off value is for a prognostic block, how many blocks should be performed before RFA, how electrodes should be oriented, the evidence for larger lesions, whether stimulation should be used before RFA, ways to mitigate complications, if different standards should be applied to clinical practice and clinical trials and the evidence for repeating RFA (see table 12 for summary).

CONCLUSIONS

Lumbar medial branch RFA may provide benefit to well-selected individuals, with MBB being more predictive than IA injections. More stringent selection criteria are likely to improve denervation outcomes, but at the expense of more false-negatives. Clinical trials should be tailored based on objectives, and selection criteria for some may be more stringent than what is ideal in clinical practice.

Celiac plexus block increases quality of life in patients with pancreatic cancer

Background

Pancreatic cancer is a malignant disease with a high mortality rate and severe pain that is challenging to manage. To reduce the excruciating abdominal pain, opioids and adjuvant agents are conventionally used.

Objectives

PRNCPB is a treatment of neural therapy. The number of studies assessing the effect on patients' QoL is limited and inconsistent. With this study, we intended to address this issue.

Study design

A prospective nonrandomized study with a series of cases of unresectable pancreatic cancer was conducted.

Setting

The study was performed at our pain clinic under real life conditions.

Materials and methods

A total number of 16 patients with severe abdominal pain were enrolled in the study all of whom had responded to combined systemic analgesic therapy inadequately and had intolerable side effects contraindicating further increase in dose. The efficacy of this invasive, palliative analgesic procedure was evaluated 35 days after PRNCPB was performed. Primary outcomes were changed in pain intensity using the VAS questionnaire. Secondary outcomes were improved in QoL using the SF-36 questionnaire. Changes in pain medications and adverse reactions were monitored.

Results

After PRNCPB patients experienced a significant decrease (P=0.002) in pain intensity as shown by the VAS score, and a decreased opiate demand. Their QoL scores considering effect sizes also improved (P<0.001). No complications attributable to PRNCPB were observed during the study period. Additionally, no adverse drug reactions were observed.

Limitations

Detection, observation, and reporting bias can be estimated as moderate. Selection bias was not detected.

Conclusion

Our results give preliminary evidence that PRNCPB might be helpful as an additional treatment to conventional pain management in end-stage pancreatic cancer patients. PRNCPB seems to improve QoL in these patients in a time frame of at least 5 weeks after intervention.

Predictors of analgesic efficacy of neurolytic celiac plexus block in patients with unresectable pancreatic cancer: the importance of timing

BACKGROUND

Neurolytic celiac plexus block (NCPB) is a safe and effective method for reducing abdominal cancer pain. However, the analgesic efficacy of NCPB is not always guaranteed. The aim of this retrospective study was to identify predictors for the analgesic efficacy of NCPB in patients with unresectable pancreatic cancer.

METHODS

Patients with unresectable pancreatic cancer who underwent NCPB from 2006 to 2015 were enrolled. Good analgesia after NCPB was defined as ≥ 50% reduction in pain score at day 30. Patient demographics, cancer characteristics, and pain-related factors were evaluated using a logistic regression analysis to identify predictors for good analgesia after NCPB. Additionally, survival outcomes were compared between patients with poor and good analgesia after NCPB.

RESULTS

A total of 112 patients satisfied the study protocol requirements. Forty-seven patients (41.9%) showed good analgesia after NCPB. Better performance status, lower serum CA 19-9 level, shorter pain duration, and lower opioid dose were observed in patients with good analgesia after NCPB. Good performance status (ECOG performance status 1 vs. 2 or 3, OR = 2.737, 95% CI = 1.149 to 6.518, P = 0.023) and low daily opioid use (< 150 vs. ≥ 150 mg, OR = 2.813, 95% CI = 1.159 to 6.831, P = 0.022) before NCPB were independent predictors of good analgesia after NCPB. The median survival was significantly lower for patients with poor analgesia after NCPB (68 vs. 150 days, P < 0.001).

CONCLUSION

NCPB should be offered early to selected patients to improve its analgesic efficacy in advance of deterioration from disease and pain in this population.

Most effective pain-control procedure for open liver surgery: a network meta-analysis

BACKGROUND

To determine the most effective pain-control procedure for open liver surgery through a network meta-analysis and provide a best developing direction in this field.

METHODS

PubMed, Embase and Cochrane Library database were searched for randomized controlled trials up to 1 July 2016. We extracted data on post-operative pain score at the 4th-8th hour and 24th hour from studies that compared various pain-control strategies. Network meta-analysis was conducted in Aggregate Data Drug Information System software by evaluating the parametric pain score at rest and on movement. Cumulative probability value was utilized to rank the procedures under examination. The inconsistency would also be tested by node-splitting models.

RESULTS

Twelve articles containing 661 patients were included. Intrathecal analgesia plus intravenous analgesia played the most effective role in pain controlling at post-operative 4-8 h (both at rest and on movement, P = 0.49 and P = 0.62, respectively) and at post-operative 24 h (both at rest and on movement, P = 0.46 and P = 0.29, respectively). Node-splitting models test revealed that no significant inconsistency existed in this research.

CONCLUSIONS

Intrathecal analgesia plus intravenous analgesia revealed the most effective clinical pain-control value for open liver surgery. More importantly, we believed that creating a better comprehensive and systematic combined pain-control procedure should be considered as the developing direction in this field.

CT guided neurolytic blockade of the coeliac plexus in patients with advanced and intractably painful pancreatic cancer

Background and aims:

Pain caused by infiltrating pancreatic cancer is complex in nature and may therefore be difficult to treat. In addition to conventional analgesics, neurolytic blockade of the coeliac plexus is often recommended. However, different techniques are advocated, and procedures vary, and the results may therefore be difficult to compare. Therefore strong evidence for the effect of this treatment is still lacking, and more studies are encouraged. Our aim was to describe our technique and procedures using a Computer Tomograph (CT) guided procedure with a dorsal approach and present the results.

Methods:

The procedures were performed in collaboration between a radiologist and an anaesthesiologist. All patients had advanced pancreatic cancer. The patients were placed in prone position on pillows, awake and monitored. Optimal placement of injection needles was guided by CT, and the radiologist injected a small dose of contrast as a control. When optimal needle position, the anaesthesiologist took over and completed the procedure. At first 40 mg methylprednisolone was injected to prevent inflammation. Thereafter a mixture of 99% ethanol diluted to 50% by ropivacaine 7.5 mg/mL to a total amount of 20–30 mL per needle was slowly injected. Repeated aspiration was performed during injection to avoid intravasal injection. Pain treatment and pain score was recorded and compared before and after the treatment.

Results:

Eleven procedures in 10 patients were performed. Age 49–75, mean 59 years. Median rest life time was 36 days (11–140). Significant reduction of analgesics was observed 1 week after the procedure, and most patients also reported reduction of pain. No serious side effects were observed.

Conclusions:

CT guided neurolytic celiac plexus blockade is a safe and effective treatment for intractable pain caused by advanced pancreatic cancer. Not all patients experience a significant effect, but the side effects are minor, and the procedure should therefore be offered patients experiencing intractable cancer related pain.

Celiac Plexus Block and Neurolysis in the Management of Chronic Upper Abdominal Pain

Chronic upper abdominal pain occurs as a complication of various malignant and benign diseases including pancreatic cancer and chronic pancreatitis, and when present may contribute to lower quality of life and higher mortality. Though various pain management strategies are available as part of a multimodal approach, they are often incompletely effective and accompanied by side effects. Pain originating in upper abdominal viscera is transmitted through the celiac plexus, which is an autonomic plexus located in the retroperitoneum at the root of the celiac trunk. Direct intervention at the level of the plexus, referred to as celiac plexus block or neurolysis depending on the injectate, is a minimally invasive therapeutic strategy which has been demonstrated to decrease pain, improve function, and reduce opiate dependence. Various percutaneous techniques have been reported, but, with appropriate preprocedural planning, use of image guidance (usually computed tomography), and postprocedural care, the frequency and severity of complications is low and the success rate high regardless of approach. The main benefit of the intervention may be in reduced opiate dependence and opiate-associated side effects, which in turn improves quality of life. Celiac plexus block and neurolysis are safe and effective treatments for chronic upper abdominal pain and should be considered early in patients experiencing such symptoms.

Opioid Reduction Following Interventional Procedures for Chronic Pain: A Synthesis of the Evidence

The past decade has witnessed the tremendous growth of procedures to treat chronic pain, which has resulted in increased third-party scrutiny. Although most of these procedures appear to be associated with significant pain relief, at least in the short and intermediate term, their ability to improve secondary outcome measures, including function and work status is less clear-cut. One of these secondary outcome measures that has garnered substantial interest in the pain and general medical communities is whether interventions can reduce opioid intake, which is associated with significant risks that in most cases outweigh the benefits in the long term. In the article, we examine whether procedural interventions for chronic pain can reduce opioid intake. Most studies that have examined analgesic reduction as a secondary outcome measure have not separated opioid and nonopioid analgesics, and, among those studies that have, few have demonstrated between-group differences. Reasons for failure to demonstrate opioid reduction can be broadly classified into procedural, design-related, clinical, psychosocial, biological, and pharmacological categories, all of which are discussed. In the future, clinical trials in which this outcome is examined should be designed to evaluate this, at least on a preliminary basis.

New Cancer Pain Treatment Options

PURPOSE OF REVIEW

Cancer pain is often incapacitating and discouraging to patients; is demoralizing to family members and care takers; and is taxing and difficult to subdue for the pain specialists. The consequences of implementing suboptimal treatment are far-reaching; therefore, effective treatment methods are in a great demand. The face of cancer pain management has changed in considerable ways, and interventional procedures have become an integral part of providing multimodal analgesia in cancer pain treatment. The goals of this review are to draw attention to the critical role that regional anesthetic nerve blocks and interventional pain management techniques play in treating malignancy-related pain and emphasize the benefits provided by the aforementioned treatment strategies.

RECENT FINDINGS

A large proportion of cancer patients continues to struggle with an inadequately treated pain despite a strict adherence to the WHO analgesic step ladder. The previous pain treatment algorithm has been modified to include peripheral neural blockade, neuro-destructive techniques, neuromodulatory device use, and intrathecal drug delivery systems. The accumulated evidence highlights the opioid-sparing qualities and other benefits afforded by these modalities: decreasing medication-induced side effects, reducing economic burden of poor analgesia, and overall improvement in quality of life of the patients afflicted with a painful neoplastic disease. The rising prevalence of cancer-related pain syndromes is paralleled by an unmatched growth of innovative treatment strategies. Modified WHO analgesic ladder represents one of the greatest paradigm shifts within the domain of oncologic pain treatment. The cancer patient population requires a prompt and liberal, albeit judicious, delivery of unorthodox pain treatment options freed from the rigid bonds of conventional guidelines and standard practices.

Pain Outcomes in Patients Undergoing CT-Guided Celiac Plexus Neurolysis for Intractable Abdominal Visceral Pain

The purpose of this study was to assess outcomes in patients who have undergone celiac plexus neurolysis (CPN) as treatment for refractory abdominal visceral pain at a tertiary care medical center. This study involved retrospective analysis of all patients who had undergone computed tomography (CT)-guided CPN over a 7-year period, as identified in the medical record. Cases were categorized into 1 of 3 groups-group 1: patients getting at least moderate improvement in pain but with improvements subsiding within 2 days; group 2: patients with some sustained pain relief but still requiring heavy doses of narcotics; group 3: patients with major or complete sustained reduction in pain where the narcotic dose was able to be reduced. One hundred thirty-eight cases were identified, 51 of which had no or insufficient follow-up, leaving 87 cases for analysis. Of the 87 cases, 31 (36%) were categorized as group 1, 21 (24%) as group 2, and 35 (40%) as group 3. There were no statistical differences in outcomes based on patient age, gender, time since diagnosis, or type of cancer. Documented postoperative complications were diarrhea (11 cases) and 1 case each of obtundation, hypotension, and presyncopal event. We conclude that patients undergoing CT-guided CPN for abdominal visceral pain achieve moderate or major short-term pain relief in a majority of cases. The procedure is safe with minimal complications.

Pulse Transit Time as a Predictor of the Efficacy of a Celiac Plexus Block in Patients With Chronic Intractable Abdominal Pain

OBJECTIVE

There is no well-defined predictor of satisfactory pain relief after celiac plexus block (CPB) at the early stage of treatment. This study evaluated whether measurement of the electrocardiographic R-wave and the arrival time of the pulses at the toe pulse transit time (E-T PTT) can be an early predictor of pain response and success of CPB in patients with chronic intractable visceral pain.

METHODS

Twelve patients aged between 20 and 80 years who underwent CPB for treatment of chronic intractable cancer-related abdominal pain were included. A successful CPB was determined as a >50% decrease on the numerical rating scale measured 24 hours after the procedure. The E-T PTT at baseline and at 5, 10, 20, and 30 minutes after the injection of local anesthetic was measured as the time between the R-wave on the electrocardiogram and the peak point of the corresponding plethysmogram wave from the ipsilateral great toe. The change in the E-T PTT that was predictive of a successful CPB was analyzed using receiver operating characteristic curve analysis.

RESULTS

A CPB was successful in 9 of 12 cases; the dE-T PTT5/E-T PTT0 of the success group was 6.84%±5.04% versus 0.72%±0.78% in the failure group (P=0.021). The mean E-T PTTx differed significantly between timepoints (F=9.313, P=0.014) and between the success and failure groups (P<0.01). The best value of dE-T PTT5/E-T PTT0 indicating a successful CPB, estimated by receiver operating characteristic curve analysis, was 2.30% (sensitivity 88.9%, specificity 100%). The area under the curve was 96% (95% confidence interval, 85.7%-100%).

CONCLUSIONS

Prolongation of E-T PTT at 5 minutes after CPB correlates closely with a significant analgesic effect.

Celiac plexus block: an anatomical study and simulation using computed tomography

Objective

To analyze anatomical variations associated with celiac plexus complex by means of computed tomography simulation, assessing the risk for organ injury as the transcrural technique is utilized.

Materials and Methods

One hundred eight transaxial computed tomography images of abdomen were analyzed. The aortic-vertebral, celiac trunk (CeT)-vertebral, CeT-aortic and celiac-aortic-vertebral topographical relationships were recorded. Two needle insertion pathways were drawn on each of the images, at right and left, 9 cm and 4.5 cm away from the midline. Transfixed vital organs and gender-related associations were recorded.

Results

Aortic-vertebral - 45.37% at left and 54.62% in the middle; CeT-vertebral - T12, 36.11%; T12-L1, 32.4%; L1, 27.77%; T11-T12, 2.77%; CeT-aortic - 53.7% at left and 46.3% in the middle; celiac-aortic-vertebral - L-l, 22.22%; M-m, 23.15%; L-m, 31.48%; M-l, 23.15%. Neither correspondence on the right side nor significant gender-related associations were observed.

Conclusion

Considering the wide range of abdominal anatomical variations and the characteristics of needle insertion pathways, celiac plexus block should not be standardized. Imaging should be performed prior to the procedure in order to reduce the risks for injuries or for negative outcomes to patients. Gender-related anatomical variations involved in celiac plexus block should be more deeply investigated, since few studies have addressed the subject.

Interventional modalities to treat cancer-related pain

Cancer-related pain is a significant cause of morbidity in those affected by both primary and metastatic disease. Although oral, transdermal, and parenteral opioid medications are an integral part of the World Health Organization's analgesic ladder, their use may be limited by side effects. Fortunately, there are advanced interventional pain management strategies effective in reducing pain in the cancer patient while mitigating the aforementioned side effects. Celiac plexus blocks and neurolysis have been proven effective in treating cancers of the abdominal viscera (ie, pancreas). Transversus abdominis plane blocks, neurolysis, and catheter placement can be used to treat cancer pain associated with the abdominal wall. Peripheral nerve blocks and catheter placement at the brachial and lumbosacral plexus or peripheral nerves treat cancer pain associated with the upper and lower limbs, whereas paravertebral and intercostal blocks treat cancer pain associated with the chest wall and ribs. Finally, alternate drug delivery methods such as intrathecal drug delivery systems concentrate medication at central opioid receptors without affecting the peripheral receptors implicated in unwanted side effects. This article provides an overview of these interventions, including indications, contraindications, and potential complications of advanced interventional pain management options available for the treatment of intractable cancer-related pain.

Establishing an optimal "cutoff" threshold for diagnostic lumbar facet blocks: a prospective correlational study

OBJECTIVES

Diagnostic medial branch blocks (MBB) are considered the reference standard for diagnosing facetogenic pain and selecting patients for radiofrequency (RF) denervation. Great controversy exists regarding the ideal cutoff for designating a block as positive. The purpose of this study is to determine the optimal pain relief threshold for selecting patients for RF denervation after diagnostic MBB.

METHODS

In this multicenter, prospective correlational study, 61 consecutive patients undergoing lumbar facet RF denervation after experiencing significant pain relief after MBB were enrolled. A positive outcome was defined as a ≥50% reduction in back pain at rest or with activity coupled with a positive satisfaction score lasting longer than 3 months. The relationship between pain relief after the blocks and denervation outcomes was evaluated by pairwise correlation matrix, receiver's operating characteristic curve, and stratifying outcomes based on 10- and 17-percentage point intervals for MBB.

RESULTS

There were no significant differences in RF outcomes based on any MBB pain relief cutoff over 50%. A trend was noted whereby those patients who obtained <50% pain relief reported poorer outcomes. No optimal threshold for designating a diagnostic block as positive, above 50% pain relief, could be calculated.

CONCLUSION

Employing more stringent selection criteria for lumbar facet RF is likely to result in withholding a beneficial procedure from a substantial number of patients, without improving success rates.

Effects of neurolytic celiac plexus block on liver regeneration in rats with partial hepatectomy

Liver regeneration is the basic physiological process after partial hepatectomy (PH), and is important for the functional rehabilitation of the liver after acute hepatic injury. This study was designed to explore the effects of neurolytic celiac plexus block (NCPB) on liver regeneration after PH. We established a model of PH in rats, assessing hepatic blood flow, liver function, and serum CRP, TNF-α, IL-1β and IL-6 concentrations of the residuary liver after PH. Additionally, histopathological studies, immunohistochemistry, and western blotting were also performed. Our results indicated that NCPB treatment after PH improved liver regeneration and survival rates, increased hepatic blood flow, reduced hepatocyte damage, decreased the secretion and release of inflammatory cytokines, increased the expression of B cell lymphoma/leukemia-2 (Bcl-2), and decreased the expression of Bcl-2 associated X protein (Bax). Additionally, Western blotting revealed that the expression of NF-κB p65 and c-Jun were decreased in liver after NCPB. In conclusion, the results of our present study indicate that NCPB treatment has a favorable effect on liver regeneration after PH. We suggest that NCPB can be utilized as an effective therapeutic method to help the functional rehabilitation of the liver after acute hepatic injury or liver cancer surgery.

Recent progress in pancreatic cancer

Pancreatic cancer is currently one of the deadliest of the solid malignancies. However, surgery to resect neoplasms of the pancreas is safer and less invasive than ever, novel drug combinations have been shown to improve survival, advances in radiation therapy have resulted in less toxicity, and enormous strides have been made in the understanding of the fundamental genetics of pancreatic cancer. These advances provide hope but they also increase the complexity of caring for patients. It is clear that multidisciplinary care that provides comprehensive and coordinated evaluation and treatment is the most effective way to manage patients with pancreatic cancer.

Recent progress in pancreatic cancer

Pancreatic cancer is currently one of the deadliest of the solid malignancies. However, surgery to resect neoplasms of the pancreas is safer and less invasive than ever, novel drug combinations have been shown to improve survival, advances in radiation therapy have resulted in less toxicity, and enormous strides have been made in the understanding of the fundamental genetics of pancreatic cancer. These advances provide hope but they also increase the complexity of caring for patients. It is clear that multidisciplinary care that provides comprehensive and coordinated evaluation and treatment is the most effective way to manage patients with pancreatic cancer.

The effect of celiac plexus block on heart rate variability

BACKGROUND

Celiac plexus block (CPB) can be used for treating intra-abdominal visceral pain syndromes. The celiac plexus is the largest plexus of the sympathetic nervous system. Several nerve blocks have a marked effect on autonomic nervous activity. Furthermore, stellate ganglion block changes cardiac autonomic nervous activity. Thus, CPB could influence the sympathetic activity of the cardiac plexus. The aim of the present study was to see whether CPB modulated heart rate variability (HRV) in patients with pancreatic cancer.

METHODS

Twelve patients received neurolytic CPB using 14 ml absolute alcohol. Data recorded in a palm-sized electrocardiographic unit were analyzed for HRV.

RESULTS

CPB using a neurolytic solution did not induce any significant changes in the low-frequency (LF)/high-frequency (HF) ratio of HRV (LF/HF, P = 0.4642). Furthermore, the procedure did not induce any significant changes in blood pressure (systolic, P = 0.5051; diastolic, P = 0.5180).

CONCLUSION

CPB did not induce any significant changes in HRV or hemodynamics.

Neurolytic transversus abdominis plane block in the palliative treatment of intractable abdominal wall pain

A 45 year old man with metastatic colon cancer presented with uncontrollable abdominal wall pain. Transversus abdominis plane (TAP) block with ropivacaine and methylprednisolone was performed with excellent pain relief, which allowed a significant weaning of the patient's opioid requirements. A second TAP block was performed with a 33% ethanol solution (ethanol and ropivacaine) with excellent pain relief. The neurolytic block appeared to offer better pain control for more than 5 days after placement until the patient finally succumbed to his illness.

The effectiveness of repeat celiac plexus neurolysis for pancreatic cancer: a pilot study

BACKGROUND

 Celiac plexus neurolysis (CPN) is an effective but temporary management tool for pancreatic cancer pain (PCP). Clinical studies have shown the duration of benefit with initial CPN to be apaproximately 3 months. When pain recurs, CPN may be repeated, but the outcomes for repeat CPN are not well established. The objective of this study is to determine the success rate and duration of relief following repeat celiac plexus neurolysis (rCPN) for PCP.

METHODS

 Patients who underwent rCPN were identified from a database and their records reviewed. Responses of rCPN were then compared with iCPN for success rates and duration of relief. Success was defined as ≥ 50% pain relief lasting ≥ 1 month.

RESULTS

 Overall, there were 24 rCPN performed. The success rate decreased from 67% after initial CPN to 29% following rCPN (P = 0.13). The mean duration of pain relief decreased in parallel from 3.4 months (iCPN) to 1.6 months (rCPN) (P = 0.03). Among those who had a successful rCPN, 2.9 months elapsed from iCPN to rCPN, with disease progression noted in 29%. In those who failed rCPN, 7.8 months elapsed, with disease progression apapreciated in 71% of cases.

CONCLUSIONS

 rCPN does not provide as much pain relief as iCPN. Disease progression as detailed on imaging appears to be a major factor in the limitations of rCPN. Further prospective studies are warranted to confirm these results and investigate the utility of rCPN.

Drug management of visceral pain: concepts from basic research

Visceral pain is experienced by 40% of the population, and 28% of cancer patients suffer from pain arising from intra- abdominal metastasis or from treatment. Neuroanatomy of visceral nociception and neurotransmitters, receptors, and ion channels that modulate visceral pain are qualitatively or quantitatively different from those that modulate somatic and neuropathic pain. Visceral pain should be recognized as distinct pain phenotype. TRPV1, Na 1.8, and ASIC3 ion channels and peripheral kappa opioid receptors are important mediators of visceral pain. Mu agonists, gabapentinoids, and GABAB agonists reduce pain by binding to central receptors and channels. Combinations of analgesics and adjuvants in animal models have supra-additive antinociception and should be considered in clinical trials. This paper will discuss the neuroanatomy, receptors, ion channels, and neurotransmitters important to visceral pain and provide a basic science rationale for analgesic trials and management.

CT-guided celiac plexus neurolysis: a review of anatomy, indications, technique, and tips for successful treatment

The celiac plexus is the largest visceral plexus and is located deep in the retroperitoneum, over the anterolateral surface of the aorta and around the origin of the celiac trunk. It serves as a relay center for nociceptive impulses that originate from the upper abdominal viscera, from the stomach to the proximal transverse colon. Celiac plexus neurolysis, with agents such as ethanol, is an effective means of diminishing pain that arises from these structures. Percutaneous imaging-guided celiac plexus neurolysis has been established as an invaluable therapeutic option in the management of intractable abdominal pain in patients with upper abdominal malignancy. The use of multidetector computed tomography (CT) for imaging guidance has superseded other modalities and allows direct visualization of the spread of the neurolytic agent in the antecrural space. Accurate depiction of the retroperitoneal anatomy and the position of the needle tip helps avoid crucial anatomic structures such as the pancreas, aorta, celiac artery, and superior mesenteric artery. Proper patient education, meticulous preprocedure planning, use of optimal multidetector CT techniques, adjunctive CT maneuvers, and postprocedure care are integral to successful celiac plexus neurolysis. Celiac plexus neurolysis does not completely abolish pain; rather, it diminishes pain, helping to reduce opioid requirements and their related side effects and improving survival in patients with upper abdominal malignancy.

Anatomical Analysis of Computed Tomography Images for Determining the Optimal Oblique Fluoroscope Angle for Percutaneous Coeliac Plexus Block

This retrospective study used abdominal computed tomography (CT) scan images to determine the optimal safe oblique angle for fluoroscopy in fluoroscope-assisted coeliac plexus block (CPB). Abdominal CT scans from 131 patients were included in the study: 42 patients with cancer of the pancreas head, 45 with cancer of the pancreas body and tail and 44 with chronic pancreatitis. The oblique angle and entry distance from the midline were measured at the T12 and L1 levels, and the safe angle range that avoided puncture of the organs was also measured. The optimal angle varied between the T12 and L1 levels, and between the right and left sides at the T12 level. There was no difference in the oblique angle between the patient groups. The optimal oblique angle for fluoroscopy was determined to be 17° for right T12, 18° for left T12, and 19° for both left and right L1.

Celiac plexus block in pancreatic neuroendocrine tumors

Pancreatic neuroendocrine tumors (pNETs), an uncommon finding, are distinct from pancreatic carcinomas. When pNETs are unresectable and progressive, visceral pain often presents and is challenging to treat. Opioids commonly used for pain control are difficult to implement in this setting because of adverse side effects such as constipation. Neurolytic celiac plexus blocks are indicated in the treatment of visceral pain related to upper abdominal malignancies when opioid analgesia does not provide adequate relief or is contraindicated because of side effects. As a result, this article presents a brief review of pNETs, celiac plexus blocks, associated side effects, and contraindications along with related literature in the context of a case study.

Pain management in pancreatic cancer

A majority of pancreatic cancer patients present with pain at the time of diagnosis. Pain management can be challenging in light of the aggressive nature of this cancer. Apart from conventional pharmacotherapy, timely treatment with neurolytic celiac plexus block (NCPB) has been shown to be of benefit. NCPB has demonstrated efficacious pain control in high quality studies with analgesic effects lasting one to two months. NCPB has also shown to decrease the requirements of narcotics, and thus decrease opioid related side effects. Another option for the control of moderate to severe pain is intrathecal therapy (IT). Delivery of analgesic medications intrathecally allows for lower dosages of medications and thus reduced toxicity. Both of the above mentioned interventional procedures have been shown to have low complication rates, and be safe and effective. Ultimately, comprehensive pancreatic cancer pain management necessitates understanding of pain mechanisms and delivery of sequential validated therapeutic interventions within a multidisciplinary patient care model.