Percutaneous destructive pain procedures on the upper spinal cord and brain stem in cancer pain: CT-guided techniques, indications and results

Pharmacological Treatments and Therapeutic Drug Monitoring in Patients with Chronic Pain

Pain is an unpleasant sensory and emotional experience that affects every aspect of a patient's life and which may be treated through different pharmacological and non-pharmacological approaches. Analgesics are the drugs most commonly used to treat pain, and in specific situations, the use of opioids may be considered with caution. These drugs, in fact, do not always induce optimal analgesia in patients, and several problems are associated with their use. The purpose of this narrative review is to describe the pharmacological approaches currently used for the management of chronic pain. We review several aspects, from the pain-scale-based methods currently available to assess the type and intensity of pain, to the most frequently administered drugs (non-narcotic analgesics and narcotic analgesics), whose pharmacological characteristics are briefly reported. Overall, we attempt to provide an overview of different pharmacological treatments while also illustrating the relevant guidelines and indications. We then report the strategies that may be used to reduce problems related to opioid use. Specifically, we focus our attention on therapeutic drug monitoring (TDM), a tool that could help clinicians select the most suitable drug and dose to be used for each patient. The actual potential of using TDM to optimize and personalize opioid-based pain treatments is finally discussed based on recent scientific reports.

Percutaneous CT-guided trigeminal tractotomy-nucleotomy under general anesthesia for intractable craniofacial pain

OBJECTIVE

When used to treat craniofacial pain, CT-guided trigeminal tractotomy-nucleotomy (TR-NC) is usually performed with local anesthesia. Unfortunately, local anesthesia is insufficient for patients with such severe pain that they cannot tolerate the required head positioning while awake. This study aimed to contextualize previous findings associated with TR-NC performed under general anesthesia. The authors examined clinical and operative factors that could impact postoperative pain outcomes.

METHODS

This is a retrospective single-institution cohort study of patients who underwent a percutaneous CT-guided TR-NC under general anesthesia at a single institution between 2012 and 2019. Outcome data were analyzed.

RESULTS

Twenty-five patients underwent CT-guided TR-NC procedures under general anesthesia; 23 met the inclusion criteria and underwent a total of 31 procedures. The procedure success rate was 74% (23/31). Approximately 50% and 40% of procedures provided pain relief for at least 6 and 12 months, respectively. The median duration of pain relief was 153 days. Adverse events, all minor and transient, occurred following 6/31 (19%) of procedures. Patients with a body mass index > 25 were less likely to experience a successful TR-NC (p = 0.045). Higher electrode ablation temperatures (p = 0.033) and more medial entry trajectories relative to the midsagittal plane (p = 0.029) characterized successful procedures.

CONCLUSIONS

These results suggest that CT-guided TR-NC performed under general anesthesia is safe and effective. Postoperative outcomes were found to be associated with a number of clinical and operative factors. Such associations should be further explored and evaluated in the context of future, better-powered analyses.

Neurosurgical Ablation for Pain: A Technology Review

Neurosurgical ablative procedures for pain have dramatically transformed over the years. Compared to their precursors, present day techniques are less invasive and more precise as a result of advances in both device engineering and imaging technology. From a clinical perspective, understanding the strengths and drawbacks of modern techniques is necessary to optimize patient outcomes. In this review, we provide an overview of the major contemporary neuroablative modalities/technologies used for treating pain. We will compare and contrast these modalities from one another with respect to their intraoperative monitoring needs, invasiveness, range of access, and lesion generation. Finally, we will provide a brief commentary on the future of neuroablation given the advent of neuromodulation options for pain control.

The Use of L2 and L3 Lumbar Sympathetic Blockade for Cancer-Related Pain, an Experience and Recommendation in the Oncologic Population

OBJECTIVE

The sympathetic nervous system has a recognized role in transmission of pain, and the lumbar sympathetic blockade is intended to provide analgesia. We share our experiences of lumbar sympathetic blockade in the treatment of cancer-related pain.

METHODS

We performed a retrospective analysis of patients with cancer-related pain in the back, abdomen, pelvis, or legs treated at Memorial Sloan Kettering Cancer Center between 2000 and 2018 undergoing lumbar sympathetic blockade at L2 or L3. Blocks were accomplished by injection of local anesthetic or local anesthetic with steroid under fluoroscopy. We measured numerical rating scale scores, percent relief, and relief time. The primary end point was defined as "effective" or "ineffective" pain relief. Effective pain relief was defined as ≥30% relief for at least one day.

RESULTS

We identified 124 data points of lumbar sympathetic blockade at L2 or L3, of which 57 were with complete data and used for analysis. Peri-injection, 42 data points had active disease whereas 15 were in remission. Lumbar sympathetic blockade was 67% effective in the back pain cohort, 82% effective in the abdominopelvic pain cohort, and 75% effective in the leg pain cohort. Seventeen data points went on to neurolysis, two to neuromodulation, and eight to intrathecal pump implantation.

CONCLUSIONS

Lumbar sympathetic blockade is effective for back, abdominopelvic, and leg pain related to cancer and its treatments. Future research should be aimed at refining its role within multimodal pain management.

Dorsal root entry zone lesion, midline myelotomy and anterolateral cordotomy

This review encompasses the most common spinal cord lesioning procedures used for the treatment of pain: dorsal root entry zone lesioning, open cordotomy, percutaneous cordotomy, and midline myelotomy. A literature review and summary of each technique regarding relevant anatomy, patient selection, surgical technique, outcomes, and complications are discussed. A general review of somatic and visceral pain pathways of the spinal cord is included, as each procedure requires an understanding of the advantages and disadvantages of various approaches to lesioning the spinal cord for pain. Neurosurgical education of these rarely used procedures needs to be included in residency and fellowship training.

Degree of knowledge of health care professionals about pain management and use of opioids in pediatrics

OBJECTIVE

To evaluate the degree of knowledge about pain management and opioids use by professionals working at three pediatric units.

DESIGN

This is a cross-sectional study.

SETTING

This study was carried out at three pediatric units (pediatrics, intensive care unit, and oncology) of Hospital de Clínicas de Porto Alegre, which is a university hospital located in southern Brazil.

SUBJECT

The subjects of this study include physicians, pharmacists, physiotherapists, nurses, nursing technicians, and nursing assistants.

METHODS

Cross-sectional study carried out in a university hospital in southern Brazil. A self-applicable semi-structured questionnaire was handed out to 182 professionals from December 2011 to March 2012.

RESULTS

The response rate was 67% (122); the average percentage of correct answers was 63.2 ± 1.4%. The most frequent errors were: an opioid must not be used if the cause of pain is unknown (47%; 54/115); patients often develop respiratory depression (42.3%; 22/52); and confusion about symptoms of withdrawal, tolerance, and dependency syndromes (81.9%; 95/116). Only 8.8% (10/114) reported the use of pain scales to identify pain in children. The most often cited hindrance to control pain was the difficulty to measure and spot pain in pediatric patients. Finally, 50.8% (62/122) of them did not have any previous training in pain management.

CONCLUSIONS

Problems in the processes of pain identification, measurement, and treatment have been found. Results suggest that there is a need for both an investment in continuing education of professionals and the development of protocols to optimize the analgesic therapy, thus preventing increased child suffering.

Cellular therapeutics delivery to the spinal cord: technical considerations for clinical application

Current literature demonstrates the efficacy of cell-based therapeutics in small animal models of varied spinal cord diseases. However, logistic challenges remain towards development of an optimized delivery approach to the human spinal cord. Clinical trials utilize a variety of methods to achieve this aim. In this article, the authors review currently employed delivery methods, compare the merits of alternate delivery paradigms, introduce their implementation in completed and ongoing clinical trials, and discuss promising near-term advances in image-guided delivery and in vivo graft tracking.

Surgical/radiological interventions for cancer pain

Pain is a major morbidity associated with cancer and up to 20% patients require invasive procedures for pain relief. Ablative techniques can be directed towards the spinal cord and brain to palliate pain or modify its perception. Anterolateral cordotomy, myelotomy, DREZotomy and cingulotomy are useful interventions for the management of refractory cancer pain. Advanced imaging modalities, including intraoperative computed tomography (CT) guidance, have increased safety and efficacy of these interventions. In this paper, authors review the recent literature regarding surgical interventions for the management of cancer pain.