Facing the challenge of pain management and opioid misuse, abuse and opioid-related fatalities

A nationwide study on consumption of opioid analgesics in Iran from 2000 to 2018

BACKGROUND

Opioid analgesics play a unique role in pain management. National opioid consumption studies could provide indirect evidence of pain management in a country. National, regional, and global opioid consumption have been studied in other countries so far; however, conducting a focused study to illuminate the consumption of opioid analgesics over the past decades in Iran seemed necessary.

AIM

The main objective of this study was to determine the consumption of opioid analgesics and explore the trend of their use during 19 years in Iran.

METHOD

Iran pharmaceutical wholesale data were used to extract the annual consumption figures of the opioid analgesics in group N02A of the World Health Organization (WHO) Anatomical Therapeutic Chemical classification and were available in Iran (morphine, fentanyl, pethidine, and oxycodone as strong opioids and, tramadol and pentazocine as weak opioids), from 2000 to 2018. Using Defined Daily Dose (DDD) by WHO and Oral Morphine Equivalent (OMEQ), the amount of annual consumption was determined in DDD/1000 inhabitants/Day (DID) and OMEQ (mg)/1000 inhabitants/Day (OID).

RESULTS

Total opioid analgesic utilization based on DID and OID increased 31.12-fold (from 0.0196 to 0.61) and 21.06-fold (from 1.97 to 41.5 mg) over 19 years, respectively with a significant sharp increase from 2003 to 2006 (ß = 1.78 (DID), P value < 0.001). Medications that constituted 70% of annual opioid analgesics utilization were morphine in 2000, compared to tramadol in 2018. The annual weak and strong opioids share were 86.7% and 13.2% in 2018, respectively.

CONCLUSION

Despite considerable growth in the consumption of opioid analgesics in Iran over nearly two decades, the consumption amount remained low, which might signal sub-optimal pain management. On the other hand, misuse and abuse seem to be the main reason behind significant increases in the consumption of opioid analgesics with less controlled distribution.

Novel digital approaches to the assessment of problematic opioid use

The opioid epidemic continues to contribute to loss of life through overdose and significant social and economic burdens. Many individuals who develop problematic opioid use (POU) do so after being exposed to prescribed opioid analgesics. Therefore, it is important to accurately identify and classify risk factors for POU. In this review, we discuss the etiology of POU and highlight novel approaches to identifying its risk factors. These approaches include the application of polygenic risk scores (PRS) and diverse machine learning (ML) algorithms used in tandem with data from electronic health records (EHR), clinical notes, patient demographics, and digital footprints. The implementation and synergy of these types of data and approaches can greatly assist in reducing the incidence of POU and opioid-related mortality by increasing the knowledge base of patient-related risk factors, which can help to improve prescribing practices for opioid analgesics.

The phenomics and genetics of addictive and affective comorbidity in opioid use disorder

Opioid use disorder (OUD) creates significant public health and economic burdens worldwide. Therefore, understanding the risk factors that lead to the development of OUD is fundamental to reducing both its prevalence and its impact. Significant sources of OUD risk include co-occurring lifetime and current diagnoses of both psychiatric disorders, primarily mood disorders, and other substance use disorders, and unique and shared genetic factors. Although there appears to be pleiotropy between OUD and both mood and substance use disorders, this aspect of OUD risk is poorly understood. In this review, we describe the prevalence and clinical significance of addictive and affective comorbidities as risk factors for OUD development as a basis for rational opioid prescribing and OUD treatment and to improve efforts to prevent the disorder. We also review the genetic variants that have been associated with OUD and other addictive and affective disorders to highlight targets for future study and risk assessment protocols.

5-O-methylcneorumchromone K Exerts Antinociceptive Effects in Mice via Interaction with GABAA Receptors

The proper pharmacological control of pain is a continuous challenge for patients and health care providers. Even the most widely used medications for pain treatment are still ineffective or unsafe for some patients, especially for those who suffer from chronic pain. Substances containing the chromone scaffold have shown a variety of biological activities, including analgesic effects. This work presents for the first time the centrally mediated antinociceptive activity of 5-O-methylcneorumchromone K (5-CK). Cold plate and tail flick tests in mice showed that the 5-CK-induced antinociception was dose-dependent, longer-lasting, and more efficacious than that induced by morphine. The 5-CK-induced antinociception was not reversed by the opioid antagonist naloxone. Topological descriptors (fingerprints) were employed to narrow the antagonist selection to further investigate 5-CK's mechanism of action. Next, based on the results of fingerprints analysis, functional antagonist assays were conducted on nociceptive tests. The effect of 5-CK was completely reversed in both cold plate and tail-flick tests by GABA_A receptor antagonist bicuculline, but not by atropine or glibenclamide. Molecular docking studies suggest that 5-CK binds to the orthosteric binding site, with a similar binding profile to that observed for bicuculline and GABA. These results evidence that 5-CK has a centrally mediated antinociceptive effect, probably involving the activation of GABAergic pathways.

A theoretical framework and nomenclature to characterize the iatrogenic contribution of therapeutic opioid exposure to opioid induced hyperalgesia, physical dependence, and opioid use disorder

Opioid use, misuse, and risky use contribute to a critically important and complex crisis in current healthcare. Consequences of long-term opioid use, including opioid induced hyperalgesia, physical dependence, and opioid use disorder, can be considered iatrogenic, or partially iatrogenic, in cases where therapeutic opioid exposures were contributory. Research investigation and presumptive clinical action are needed to attenuate the iatrogenic component of the opioid crisis; treatment of individuals already suffering from opioid use disorder will not prevent incident cases. This work will be challenged by a remarkably high degree of complexity involving myriad and highly variable factors along the continuum from initial opioid exposure to long-term opioid use. An organized view of this complex problem should accelerate the pace of innovation and facilitate clinical implementation of research findings. Herein, we propose a theoretical framework and modern nomenclature for characterizing therapeutic opioid exposure and the degree to which it contributes iatrogenically to adverse outcomes. In doing so, we separate the role of exposure from other factors contributing to long-term opioid use, clarify the relationship between opioid exposure and outcomes, emphasize that exposure source is an important consideration for health services research and practice in the areas of pain treatment and opioid prevention, and recommend terminology necessary to quantify therapeutic opioid exposure separately from nonmedical exposure.

Association Between Diagnoses of Chronic Noncancer Pain, Substance Use Disorder, and HIV-Related Outcomes in People Living With HIV

BACKGROUND

Chronic pain is common in people living with HIV (PLWH). Few studies have evaluated the association between the diagnoses of chronic pain, substance use disorder (SUD), and HIV-related outcomes in clinical settings over a 10-year period.

METHODS

Using electronic medical records, the study described psychiatric diagnoses, pain medication, and HIV-related variables in PLWH and examined the factors associated with pain diagnosis and HIV-related outcomes.

RESULTS

Among 3528 PLWH, more than one-third exhibited a chronic pain diagnosis and more than one-third a psychiatric disorder. Chronic pain diagnosis has been associated with SUD and mood and anxiety disorders and occurred before SUD or psychiatric disorders about half of the time. Opioids have been commonly prescribed for pain management, more often than nonopioid analgesic, without any change in prescription pattern over the 10-year period. A dual diagnosis of pain and SUD has been associated with more psychiatric disorders and had a negative impact on the pain management by requesting more health care utilization and higher frequency of both opioid and nonopioid medication prescriptions. Chronic pain and SUD had a negative impact on ART adherence. SUD but not chronic pain has been associated with an unsuppressed HIV viral load.

CONCLUSIONS

In the current intertwining opioid prescription and opioid epidemic, opioids are still commonly prescribed in PLWH in HIV care. A diagnosis of chronic pain and/or SUD worsened the HIV-related outcomes, emphasizing the potential risk of the HIV epidemic. These findings called for a better coordinated care program in HIV clinics.

Surgeon motivation, and obstacles to the implementation of minimally invasive spinal surgery techniques

Background

This study aimed to analyze the motivators and obstacles to the implementation of minimally invasive spinal surgery techniques (MISST) by spinal surgeons. Motivators and detractors may impact the availability of MISST to patients and drive spine surgeons' clinical decision-making in the treatment of common degenerative conditions of the lumbar spine.

Methods

The authors solicited responses to an online survey sent to spine surgeons by email, and chat groups in social media networks including Facebook, WeChat, WhatsApp, and Linkedin. Descriptive statistics were employed to count the responses and compared to the surgeon's training. Kappa statistics and linear regression analysis of agreement were performed.

Results

A total of 430 surgeons accessed the survey. The completion rate was 67.4%. A total of 292 surveys were submitted by 99 neurosurgeons (33.9%), 170 orthopaedic surgeons (58.2%), and 23 surgeons of other postgraduate training (7.9%). Personal interest (82.5%) and patient demand (48.6%) were the primary motivators for MISST implementation. High equipment (48.3%) and disposables (29.1%) cost were relevant obstacles to MISST implementation. Local workshops (47.6%) and meetings in small groups (31.8%) were listed as the primary knowledge sources. Only 12% of surgeons were fellowship trained, but 46.3% of surgeons employed MISST in over 25% of their cases.

Conclusions

The rate of implementation of MISST reported by spine surgeons was found to be high but impeded by the high cost of equipment and disposables. The primary motivators for spine surgeons' desire to implement were personal interest and patient demand.

Five-year clinical outcomes with endoscopic transforaminal outside-in foraminoplasty techniques for symptomatic degenerative conditions of the lumbar spine

Background

Lumbar foraminal stenosis in the extraforaminal zone is best directly visualized with the outside-in transforaminal endoscopic technique. Stenosis in that area is often missed with traditional translaminar surgery. The authors analyzed the long-term 5-year clinical results, reoperation rates, and unintended after care with the outside-in endoscopic transforaminal foraminoplasty for symptoms from lumbar foraminal stenosis to better establish clinical indications and prognosticators of favorable outcomes.

Methods

Long-term 5-year Macnab outcomes, visual analog scale (VAS) scores, complications, and unintended aftercare were analyzed in a series of 90 patients treated with the transforaminal outside-in selective endoscopic discectomy (SED™) with foraminoplasty for foraminal and lateral recess stenosis.

Results

At minimum 5-year follow-up, excellent results according to the Macnab criteria were obtained in 61 (67.8%) patients, good in 23 (25.6%), fair in 6 (6.7%), respectively. The mean preoperative VAS 7.55. The mean postoperative VAS was 2.87 and at last follow-up 2.53. Both postoperative VAS and last follow-up VAS were statistically reduced at a significance level of P<0.0001. Postoperative dysesthesia occurred in 8 patients (8.9%). While most of the 32 follow-up surgeries following SED™ were additional endoscopic decompressions and rhizotomies (24/32; 75%) were non-fusion procedures, only 8 of the whole study series of 90 patients (8.9%) underwent fusion at the index SED™ level within the minimum 5-year follow-up period. One patient opted for an open laminectomy (1.1%).

Conclusions

Patients with symptomatic foraminal stenosis may be treated successfully in a staged manner with outside-in transforaminal endoscopic decompression while maintaining favorable long-term outcomes without the excessive need for fusion in the vast majority of patients. The reoperation fusion rate at 5-year follow-up was approximately 3 times lower when compared to recently reported reoperation rates following traditional translaminar decompression/fusion.

Regional variations in acceptance, and utilization of minimally invasive spinal surgery techniques among spine surgeons: results of a global survey

Background

Regional differences in acceptance and utilization of MISST by spine surgeons may have an impact on clinical decision-making and the surgical treatment of common degenerative conditions of the lumbar spine. The purpose of this study was to analyze the acceptance and utilization of various minimally invasive spinal surgery techniques (MISST) by spinal surgeons the world over.

Methods

The authors solicited responses to an online survey sent to spine surgeons by email, and chat groups in social media networks including Facebook, WeChat, WhatsApp, and Linkedin. Surgeons were asked the following questions: (I) Do you think minimally invasive spinal surgery is considered mainstream in your area and practice setting? (II) Do you perform minimally invasive spinal surgery? (III) What type of MIS spinal surgery do you perform? (IV) If you are performing endoscopic spinal decompression surgeries, which approach do you prefer? The responses were cross-tabulated by surgeons' demographic data, and their practice area using the following five global regions: Africa & Middle East, Asia, Europe, North America, and South America. Pearson Chi-Square measures, Kappa statistics, and linear regression analysis of agreement or disagreement were performed by analyzing the distribution of variances using statistical package SPSS Version 25.0.

Results

A total of 586 surgeons accessed the survey. Analyzing the responses of 292 submitted surveys regional differences in opinion amongst spine surgeons showed that the highest percentage of surgeons in Asia (72.8%) and South America (70.2%) thought that MISST was accepted into mainstream spinal surgery in their practice area (P=0.04) versus North America (62.8%), Europe (52.8%), and Africa & Middle East region (50%). The percentage of spine surgeons employing MISST was much higher per region than the rate of surgeons who thought it was mainstream: Asia (96.7%), Europe (88.9%), South America (88.9%), and Africa & Middle East (87.5%). Surgeons in North America reported the lowest rate of MISST implementation globally (P<0.000). Spinal endoscopy (59.9%) is currently the most commonly employed MISST globally followed by mini-open approaches (55.1%), and tubular retractor systems (41.8%). The most preferred endoscopic approach to the spine is the transforaminal technique (56.2%) followed by interlaminar (41.8%), full endoscopic (35.3%), and over the top MISST (13.7%).

Conclusions

The rate of implementation of MISST into day-to-day clinical practice reported by spine surgeons was universally higher than the perceived acceptance rates of MISST into the mainstream by their peers in their practice area. The survey suggests that endoscopic spinal surgery is now the most commonly performed MISST.

Is Asia truly a hotspot of contemporary minimally invasive and endoscopic spinal surgery?

Background

The purpose of this study was to analyze the training in relation to practice patterns of surgeons in Asia who perform lumbar endoscopic spinal surgery in comparison to surgeons the world over. The authors solicited responses to an online survey sent to spine surgeons.

Methods

Pearson Chi-Square measures, Kappa statistics, and linear regression analysis of agreement or disagreement were performed by analyzing the distribution of variances of responses in relation to surgeons' training using statistical package SPSS Version 25.0.

Results

A total of 430 surgeons accessed the survey. The completion rate was 67.4%. Analyzing the responses of 292 surveys submitted by 97 neurosurgeons (33.2%), 161 orthopaedic surgeons (55.1%), and 34 surgeons of other postgraduate training (11.6%) showed that only 14.0% (41/292) of surgeons had completed a fellowship. Ninety-one of the 292 respondents were from Asian countries/regions. A statistically significantly higher percentage of Asian surgeons (96.7%) compared to non-Asian surgeons (81.6%) indicated that they perform modern minimally invasive (MIS) and endoscopic spinal (ES) surgery (P=0.001). Spinal endoscopy was employed by 70.3% of Asian versus 55.2% of non-Asian surgeons (P=0.015). Endoscopic decompression techniques requiring advanced training was employed nearly twice as high by the Asian surgeons than by non-Asian.

Conclusions

Training requirements for MIS and ES surgery and implementation of privileges vary in different parts of the world. While industry-sponsored weekend cadaver workshops have remained the mainstay of training aspiring endoscopic spinal surgeons in North America and Europe leaving many of them to become autodidacts.

Surgeon training and clinical implementation of spinal endoscopy in routine practice: results of a global survey

Background

Training of spine surgeons may impact the availability of contemporary minimally invasive spinal surgery (MIS) to patients and drive spine surgeons' clinical decision-making when applying minimally invasive spinal surgery techniques (MISST) to the treatment of common degenerative conditions of the lumbar spine. Training requirements and implementation of privileges vary in different parts of the world. The purpose of this study was to analyze the training in relation to practice patterns of surgeons who perform lumbar endoscopic spinal surgery the world over.

Methods

The authors solicited responses to an online survey sent to spine surgeons by email, and chat groups in social media networks including Facebook, WeChat, WhatsApp, and Linkedin. Surgeons were asked the following questions: (I) please indicate your training? (II) What type of MISST spinal surgery do you perform? (III) How would you rate your experience in MIS lumbar spinal surgery and what percentage of your practice is MISST? And (IV) which avenue did you use to train for the MISST you currently employ in your clinical practice today? Descriptive statistics were applied to count responses and cross-tabulated them to the surgeon's training. Pearson Chi-square measures, kappa statistics, and linear regression analysis of agreement or disagreement were performed by analyzing the distribution of variances using statistical package SPSS version 25.0.

Results

A total of 430 surgeons accessed the survey. The completion rate was 67.4%. Analyzing the responses of 292 surveys submitted by 97 neurosurgeons (33.2%), 161 orthopaedic surgeons (55.1%), and 34 surgeons of other postgraduate training (11.6%) showed that only 14% (41/292) of surgeons had completed a fellowship. Surgeons rated their skill level 33.5% of the time as master and experienced surgeon, and 35.6% of the time as novice or surgeon with some experience. There were more master (64.6% versus 29.2%) and experienced (52% versus 40%) surgeons amongst orthopaedic surgeons than amongst neurosurgeons at a statistically significant level (P=0.11). There were near twice as many orthopaedic surgeons (54.3%) using endoscopic procedures in the lumbar spine as their favorite MISST than neurosurgeons (35.4%; P=0.096). Endoscopic spine surgeons' main sources of knowledge acquisition were (I) learning in small meetings (57.3%), (II) attending workshops (63.1%), and (III) national and international conferences (59.8%).

Conclusions

The majority of spine surgeons reported more than half of their cases employing MISST at a high skill level. Very few MISST surgeons are fellowship trained but attend workshops and various meetings suggesting that many of them are self-thought. Orthopaedic surgeons were more likely to implement endoscopic spinal surgery into the routine clinical practice. As endoscopic spine surgery gains more traction and patient demand, minimal adequate training will be part of the ongoing debate.

Use of "Inside-Out" Technique for Direct Visualization of a Vacuum Vertically Unstable Intervertebral Disc During Routine Lumbar Endoscopic Transforaminal Decompression-A Correlative Study of Clinical Outcomes and the Prognostic Value of Lumbar Radiographs

Background

The purpose of this study was to record the frequency of lumbar intervertebral disc vacuum phenomenon on routine lumbar plain films taken prior to transforaminal endoscopic decompression surgery for sciatica-type leg and back pain and to correlate it with visualized intradiscal pathology and clinical outcomes.

Methods

A prospective case series study of 200 consecutive patients with an average mean follow-up of 41.85 months who underwent lumbar endoscopic transforaminal decompression at 236 lumbar levels was conducted. The sensitivity, specificity, and accuracy of vacuum phenomenon on preoperative x-ray to predict the presence of an empty vacuum disc found during transforaminal microdiscectomy using the "inside-out" approach were calculated using the YESS™ technique. Clinical outcomes were assessed by both Macnab criteria and visual analog score (VAS) reduction.

Results

Of the 200 patients evaluated, 124 (62%) were deemed to have a vacuum disc on intraoperative probing using the "inside-out" technique. During needle insertion the more severely degenerative discs are met with negative pressures manifested by an air discogram. According to Macnab criteria, all patients who also had extruded disc herniations had excellent results (8 of 200), with the mean VAS decreasing from 6.1 ± 2.6 preoperatively to 1.9 ± 1.4 at the final follow-up (P < .01). This indicates a more severely degenerative disc causing nonspecific back pain due to lack of anterior column support from the intervertebral disc, accentuating foraminal stenosis. Patients with contained disc herniations (62 of 200) had excellent and good results 82.2% of the time. The mean VAS decreased from 6.9 ± 1.7 preoperatively to 2.2 ± 1.1 at final follow-up (P < .01). This identifies the disc as a contributing factor in low back pain. It can also identify the disc and annulus in combination with foraminal stenosis as a contributing factor. In the spinal stenosis group (130 of 200), 81.5% of patients had excellent to good results, and the mean VAS decreased from 6.3 ± 1.5 preoperatively to 2.1 ± 1.2 at final follow-up (P < .01). An analysis of lumbar x-ray vacuum phenomenon in patients with visualized vacuum disc showed true-positive (35 patients) and false-negative (89 patients), compared with an x-ray negative grading in patients without intraoperatively visualized vacuum disc of false-positive (2 patients); and true-negative (74 patients); this allowed for calculation of sensitivity (28.2%), specificity (97.4%), and positive predictive value (94.6%) of preoperative diagnostic x-ray in relation to intraoperatively visualized presence of the vacuum disc during subsequent endoscopic decompression surgery. Direct endoscopic visualization of the inside of the vacuum disc revealed longitudinal fissuring of the intervertebral disc as the most common finding in 77 of the 124 patients (62.1%) with a vacuum disc. Cavitation with delamination was the second most common observation (21 patients). Fair outcomes were associated with cavitation and delamination of the intervertebral disc from the endplates (P < .0001).

Conclusions

A vacuum phenomenon seen on lumbar x-rays is highly specific for a source of one component that is actually a multiple source of nonspecific common back pain. A vacuum disc being found during "inside-out" transforaminal discectomy actually encompasses the disc, annulus, and foraminal stenosis as a multifactorial source of nonspecific common back pain. Further studies of better prognosticators of failed endoscopic transforaminal discectomy are required and are underway by the coauthors.

Guidelines for Monitoring Patients Using Opioid Therapy

Opioid-related morbidity and mortality have increased to epidemic proportions over the past 20 years. Gynecologists play an integral role in addressing this epidemic through management of patients with pain, specifically through prescribing and monitoring practices. Practical recommendations are provided for clinicians caring for noncancer patients on chronic opioid therapy. Recommendations are largely based on national consensus guidelines with a focus on frequency and content of follow-up, identification of high risk behaviors, and reassessment of goals of treatment.

The Concept for A Standalone Lordotic Endoscopic Wedge Lumbar Interbody Fusion: The LEW-LIF

OBJECTIVE

To review concepts of a standalone endoscopically assisted lumbar interbody fusion as a simplified method to treat spinal instability.

METHODS

MacNab outcomes and complications were analyzed in a series of 48 consecutive patients who underwent standalone lordotic endoscopic wedge lumbar interbody fusion (LEW-LIF) for advanced lumbar disc degeneration, spinal stenosis, and spondylolisthesis.

RESULTS

Forty-two of the 48 patients (77.8%) did well with excellent and good outcomes with a follow up of up to 20 months. Fair outcomes were reported by 4, and poor by another 2 patients, respectively. Six patients had endoscopic decompression procedures at another level. Four patients underwent open transforaminal lumbar interbody fusion revision surgery including the index level between 2 to 6 months postoperatively. An L5 vertebral body fracture was noted in 1 of these 4 patients. Another patient underwent removal of the extruded L3/4 cage. The cage fractured in one additional asymptomatic patient not requiring any intervention. No patient had a wound infection, or permanent sensory, or motor dysfunction. However, 29 patients developed a postoperative irritation of the dorsal root ganglion with burning leg pain typically between postoperative weeks 2 and 6. Symptoms were treated with activity modification, gabapentin, and transforaminal epidural steroid injections in 12 patients (25%).

CONCLUSION

Standalone LEW-LIF was associated with favorable clinical outcomes in the majority of patients. Patient-related predictors of less favorable outcomes considering normal variations as well as patho-anatomy may aid in the development of next-generation implants.

Incidence, Management, and Cost of Complications After Transforaminal Endoscopic Decompression Surgery for Lumbar Foraminal and Lateral Recess Stenosis: A Value Proposition for Outpatient Ambulatory Surgery

Objective

The objective of this study is to analyze incidence, estimate cost savings, and evaluate best management practices of complications resulting from outpatient transforaminal endoscopic decompression surgery for lumbar foraminal and lateral recess stenosis performed in an ambulatory surgery center.

Background

Endoscopic spinal surgery is gaining popularity for the treatment of lumbar disc herniations. Recent advances in surgical techniques allow for endoscopically assisted bony decompression for neurogenic claudication symptoms due to spinal stenosis. Postoperative complications from dural tears, recurrent disc herniations, nerve root injuries, foot drop, and facet and pedicle fractures, and postoperative sequelae such as dysesthetic leg pain and infiltration of the surgical access and spinal canal with irrigation fluid causing spinal headaches and painful wound swelling, as well as failure to cure, have been reported.

Methods

A retrospective study of 1839 consecutive patients with an average mean follow up of 33 months (range: 24 to 85 months) that underwent transforaminal endoscopic decompression surgery at 2076 levels between 2006 and 2015 was conducted to analyze incidence, and estimate the cost savings of postoperative adverse events following endoscopic foraminotomy and microdiscectomy. Complications were stratified using Dindo's 7-category grading system, distinguishing them from procedure-inherent sequelae as well as failure to cure. Only patients with unilateral radiculopathy due to either herniated disc or lateral recess stenosis were included in this study. Preoperatively, disc migration was graded by direction and distance from the disc space according to Lee's radiologic 4-zone classification. The type of disc herniation was classified either as contained or extruded. Contained herniations were further subclassified as disc protrusions versus disc bulges. In addition, the preoperative disc height was recorded. Bony spinal foraminal stenosis and lateral recess stenosis were graded on preoperative magnetic resonance imaging and computed tomography scans into mild, moderate, and severe by dividing the lumbar neuroforamen into 3 zones: (1) entry zone, (2) midzone, and (3) exit zone. Surgical outcomes were classified according to the Macnab criteria. In addition, reduction in the visual analog scale (VAS) scores were assessed.

Results

According to the Macnab criteria, excellent and good results were obtained in 82.2% of patients with extruded disc fragment (331/1839). In this group, the mean VAS score decreased from 5.9 ± 2.5 preoperatively to 2.4 ± 1.8 at final follow-up (P < .01). Patients with contained disc herniations (648/1839) had excellent and good results 72.7% of the time. In this group, the mean VAS score decreased from 7.2 ± 1.6 preoperatively to 3.1 ± 1.5 at final follow-up (P < .01). In the spinal stenosis group (860/1839), 75% of patients had excellent to good results. Postoperative grade I complications (any deviation from normal postoperative course treated with observation) occurred in 2 patients who immediately developed foot drop postoperatively on the surgical side (0.11%) and in another 2 patients (0.11%) with incidental durotomy. Grade II complications (any deviation with pharmacological interventions) occurred in 11 patients due to chronic obstructive pulmonary disease exacerbation, and in another 2 patients due to infections as the latter were successfully treated with antibiotics. Grade IIIb complications (any deviation requiring surgical, endoscopic, or radiological intervention under general anesthesia) occurred in 9 patients with reherniations of extruded discs within the first 3 postoperative months (recurrence rate 2.7%). Reherniations were associated with preserved disc height of > 6 mm (P < .02). Grade IV (organ failure), and grade V (death) complications did not occur. Procedure-inherent sequelae from adverse operative side effects were noted in 8 patients with spinal headaches (0.44%), and in 69 patients (3.75%), who had extravasations of irrigation fluid into the subcutaneous tissues causing wound swelling. Another 229 patients developed postoperative dysesthetic leg pain due to irritation of the dorsal root ganglion (12.45%), which was associated with severe foraminal stenosis (P < .01) and improved with supportive care in all cases. Failure to cure occurred in 39 patients (2.12%) with bony stenosis in the central canal, and lateral recess involving the entry zone of the neuroforamen and in 41 patients (2.23%) with contained disc herniations.

Conclusions

Complications after outpatient transforaminal endoscopic decompression surgery with respect to reherniation, wound infections, durotomy, and nerve root injury are approximately 1 magnitude lower than equivalent reported complication rates with microdiscectomy while delivering comparable clinical outcomes and lower readmission rates to an emergency room or hospital. Postoperative sequelae are typically self-limiting and successfully managed with supportive care measures. Significant cost savings are realized due to a considerably lower rate of decompensated postoperative medical problems.

A brief review of the genetics and pharmacogenetics of opioid use disorders

Increased physician prescribing of opioids to treat chronic nonprogressive pain has been accompanied by an increase in opioid addiction. Twin studies of opioid addiction are consistent with an inherited component of risk, approximately 50%. Several genome-wide association study (GWAS) reports indicate that genetic risk for opioid addiction is conveyed by many alleles of small effect (odds ratios <1.5). These reports have detected alleles in potassium-ion-channel genes (KCNC1 and KCNG2) and in a glutamate receptor auxiliary protein (CNIH3). Additionally, a variant at the µ-opioid receptor gene (OPRM1), which regulates OPRM1 expression appears promising. In pharmacogenetics of opioid addictions, methadone dose may be regulated by variants in cytochrome P450 2B6 (CYP2B6), a methadone-metabolizing enzyme, and by a locus 300 kb 5' to OPRM1. A δ-opioid-receptor gene single-nucleotide polymorphism may predict treatment response to methadone versus buprenorphine. To achieve better progress, larger sample sizes are needed for GWAS research, including controls with chronic opioid exposure, but no addiction. Large clinical trials comparing effective pharmacotherapies for opioid addiction (naltrexone, methadone, and buprenorphine) are needed for pharmacogenetic progress.

Readmissions After Outpatient Transforaminal Decompression for Lumbar Foraminal and Lateral Recess Stenosis

Background

The objective of this study was to analyze readmission rates after outpatient transforaminal endoscopic decompression surgery for lumbar foraminal and lateral recess stenosis done in an ambulatory surgery center. Endoscopic lumbar spinal surgery is gaining popularity for the treatment of lumbar disc herniations. Recent advances in surgical techniques allow for percutaneous endoscopically assisted bony decompression for neurogenic claudication symptoms due to spinal stenosis. The surgery can be done under local anesthesia and sedation. Patients may be discharged home within hours from surgery, and complications are rare. However, readmissions for recurrent disc herniations, failure of pain relief, dysesthetic leg pain, nerve root injuries with foot drop, and facet and pedicle fractures have been reported.

Methods

A retrospective study of 1839 consecutive patients with an average mean follow up of 33 months (range 24 to 85 months) that underwent percutaneous endoscopic surgery at 2076 levels between 2006 and 2015 was conducted with the intent of identifying factors associated with emergency room or hospital readmission following endoscopic foraminotomy and microdiscectomy. Only patients with unilateral radiculopathy due to either herniated disc or lateral recess stenosis were included in this study. Preoperatively, disc migration was graded by direction and distance from the disc space according to Lee's radiologic 4-zone classification. The type of disc herniation was classified either as extruded or contained. Contained herniations were further subclassified as disc protrusions versus disc bulges. In addition, the preoperative disc height was recorded. Bony spinal foraminal stenosis and lateral recess stenosis were graded on preoperative magnetic resonance imaging and computed tomography scans into mild, moderate, and severe by dividing the lumbar neuroforamen into 3 zones: (a) entry zone, (b) midzone, and (c) exit zone. Surgical outcomes were classified according to the Macnab criteria. In addition, reduction in visual analog scores (VASs) were assessed. The treating physician (KUL) performed all surgeries.

Results

According to the Macnab criteria, excellent and good results were obtained in 82.2% of patients with extruded disc fragment (331/1839). In this group, the mean VAS decreased from 5.9 ± 2.5 preoperatively to 2.4 ± 1.8 at the final follow up (P < .01). Patients with contained disc herniations (648/1839) had excellent and good results 72.7% of the time. In this group, the mean VAS decreased from 7.2 ± 1.6 preoperatively to 3.1 ± 1.5 at the final follow up (P < .01). In the spinal stenosis group (860/1839), 75% of patients had excellent to good results. There were no major approach-related complications. Sixty-nine patients had extravasations of irrigation fluid into the subcutaneous tissues (3.8%). Eight patients developed spinal headaches (0.4%). Two patients developed foot drop on the surgical side immediately postoperatively (0.1%). Reherniations of extruded discs occurred in 9 patients (2.7% recurrence rate). Failure of pain relief without significant improvement of walking endurance occurred in 29 patients with bony stenosis in the central canal, lateral recess, and entry zone of the neuroforamen (3.3%). Reherniations were associated with preserved disc height of >6 mm (P < .02). Dysesthetic leg pain due to dorsal root ganglion irritation occurred in 229 patients (12.4%) and was unrelated to case frequency but was associated with severe foraminal stenosis (P < .01). All 229 patients improved with supportive care. Facet or pedicle fractures did not occur in this series. There were 26 acute care (within 6 weeks from surgery) postoperative emergency room visits [16 of which resulted in readmission to a hospital over the 9-year study period (0.86%): 9 for dysesthetic leg pain, 2 for wound infections, and 5 for poorly controlled incisional pain].

Conclusions

Transforaminal endoscopic decompression can be successfully carried out in an outpatient surgery center setting. Readmissions due to reherniations, postoperative complications, or poor pain control are uncommon.

Managing Concerning Behaviors in Patients Prescribed Opioids for Chronic Pain: A Delphi Study

BACKGROUND

Current guideline-recommended monitoring of patients prescribed long-term opioid therapy (LTOT) for chronic pain will likely result in increased identification of behaviors of concern for misuse and addiction, but there is a dearth of empiric evidence about how these behaviors should be managed.

OBJECTIVE

To establish expert consensus about treatment approaches for common and challenging concerning behaviors that arise among patients on LTOT.

DESIGN

We used a Delphi approach, which allows for generation of consensus.

PARTICIPANTS

Participants were clinical experts in chronic pain and opioid prescribing recruited from professional societies and other expert groups.

MAIN MEASURES

The Delphi process was conducted online, and consisted of an initial brainstorming round to identify common and challenging behaviors, a second round to identify management strategies for each behavior, and two rounds to establish consensus and explore disagreement/uncertainty.

KEY RESULTS

Forty-two participants completed round 1, 22 completed round 2, 30 completed round 3, and 28 completed round 4. Half of round 1 participants were female (52%), and the majority were white (83%). Most (71%) were physicians, and most participants practiced in academic primary (40%) or specialty care (19%).The most frequently cited common and challenging behaviors were missing appointments, taking opioids for symptoms other than pain, using more opioid medication than prescribed, asking for an increase in opioid dose, aggressive behavior, and alcohol and other substance use. Across behaviors, participants agreed that patient education and information gathering were important approaches. Participants also agreed that stopping opioids is not important initially, but if initial approaches do not work, tapering opioids and stopping opioids immediately may become important approaches.

CONCLUSIONS

This study presents clinical expert consensus on how to manage concerning behaviors among patients on LTOT. Future research is needed to investigate how implementing these management strategies would impact patient outcomes, practice and policy.