Comparing the Efficacy of Dorsal Root Ganglion Stimulation With Conventional Medical Management in Patients With Chronic Postsurgical Inguinal Pain: Post Hoc Analyzed Results of the SMASHING Study

OBJECTIVES

Approximately 10% of patients who undergo inguinal hernia repair or Pfannenstiel incision develop chronic (> three months) postsurgical inguinal pain (PSIP). If medication or peripheral nerve blocks fail, a neurectomy is the treatment of choice. However, some patients do not respond to this treatment. In such cases, stimulation of the dorsal root ganglion (DRG) appears to significantly reduce chronic PSIP in selected patients.

MATERIALS AND METHODS

In this multicenter, randomized controlled study, DRG stimulation was compared with conventional medical management (CMM) (noninvasive treatments, such as medication, transcutaneous electric neurostimulation, and rehabilitation therapy) in patients with PSIP that was resistant to a neurectomy. Patients were recruited at a tertiary referral center for groin pain (SolviMáx, Eindhoven, The Netherlands) between March 2015 and November 2016. Suitability for implantation was assessed according to the Dutch Neuromodulation Association guidelines. The sponsor discontinued the study early owing to slow enrollment. Of 78 planned patients, 18 were randomized (DRG and CMM groups each had nine patients). Six patients with CMM (67%) crossed over to DRG stimulation at the six-month mark.

RESULTS

Fifteen of the 18 patients met the six-month primary end point with a complete data set for a per-protocol analysis. Three patients with DRG stimulation had a negative trial and were lost to follow-up. The average pain reduction was 50% in the DRG stimulation and crossover group (from 6.60 ± 1.24 to 3.28 ± 2.30, p = 0.0029). Conversely, a 13% increase in pain was observed in patients with CMM (from 6.13 ± 2.24 to 6.89 ± 1.24, p = 0.42). Nine patients with DRG stimulation experienced a total of 19 adverse events, such as lead dislocation and pain at the implantation site.

CONCLUSIONS

DRG stimulation is a promising effective therapy for pain relief in patients with PSIP resistant to conventional treatment modalities; larger studies should confirm this. The frequency of side effects should be a concern in a new study.

CLINICAL TRIAL REGISTRATION

The Clinicaltrials.gov registration number for the study is NCT02349659.

Safety and efficacy of occipital nerve stimulation for attack prevention in medically intractable chronic cluster headache (ICON): a randomised, double-blind, multicentre, phase 3, electrical dose-controlled trial

BACKGROUND

Occipital nerve stimulation (ONS) has shown promising results in small uncontrolled trials in patients with medically intractable chronic cluster headache (MICCH). We aimed to establish whether ONS could serve as an effective treatment for patients with MICCH.

METHODS

The ONS in MICCH (ICON) study is an investigator-initiated, international, multicentre, randomised, double-blind, phase 3, electrical dose-controlled clinical trial. The study took place at four hospitals in the Netherlands, one hospital in Belgium, one in Germany, and one in Hungary. After 12 weeks' baseline observation, patients with MICCH, at least four attacks per week, and history of being non-responsive to at least three standard preventive drugs, were randomly allocated (at a 1:1 ratio using a computer-generated permuted block) to 24 weeks of occipital nerve stimulation at either 100% or 30% of the individually determined range between paraesthesia threshold and near-discomfort (double-blind study phase). Because ONS causes paraesthesia, preventing masked comparison versus placebo, we compared high-intensity versus low-intensity ONS, which are hypothesised to cause similar paraesthesia, but with different efficacy. In weeks 25-48, participants received individually optimised open-label ONS. The primary outcome was the weekly mean attack frequency in weeks 21-24 compared with baseline across all patients and, if a decrease was shown, to show a group-wise difference. The trial is closed to recruitment (ClinicalTrials.gov NCT01151631).

FINDINGS

Patients were enrolled between Oct 12, 2010, and Dec 3, 2017. We enrolled 150 patients and randomly assigned 131 (87%) to treatment; 65 (50%) patients to 100% ONS and 66 (50%) to 30% ONS. One of the 66 patients assigned to 30% ONS was not implanted and was therefore excluded from the intention-to-treat analysis. Because the weekly mean attack frequencies at baseline were skewed (median 15·75; IQR 9·44 to 24·75) we used log transformation to analyse the data and medians to present the results. Median weekly mean attack frequencies in the total population decreased from baseline to 7·38 (2·50 to 18·50; p<0·0001) in weeks 21-24, a median change of -5·21 (-11·18 to -0·19; p<0·0001) attacks per week. In the 100% ONS stimulation group, mean attack frequency decreased from 17·58 (9·83 to 29·33) at baseline to 9·50 (3·00 to 21·25) at 21-24 weeks (median change from baseline -4·08, -11·92 to -0·25), and for the 30% ONS stimulation group, mean attack frequency decreased from 15·00 (9·25 to 22·33) to 6·75 (1·50 to 16·50; -6·50, -10·83 to -0·08). The difference in median weekly mean attack frequency between groups at the end of the masked phase in weeks 21-24 was -2·42 (95% CI -5·17 to 3·33). In the masked study phase, 129 adverse events occurred with 100% ONS and 95 occurred with 30% ONS. None of the adverse events was unexpected but 17 with 100% ONS and eight with 30% ONS were labelled as serious, given they required brief hospital admission for minor hardware-related issues. The most common adverse events were local pain, impaired wound healing, neck stiffness, and hardware damage.

INTERPRETATION

In patients with MICCH, both 100% ONS intensity and 30% ONS intensity substantially reduced attack frequency and were safe and well tolerated. Future research should focus on optimising stimulation protocols and disentangling the underlying mechanism of action.

FUNDING

The Netherlands Organisation for Scientific Research, the Dutch Ministry of Health, the NutsOhra Foundation from the Dutch Health Insurance Companies, and Medtronic.

Considerations on spent fuel behavior for transport after extended storage

Packages for the transport of spent nuclear fuel shall meet the International Atomic Energy Agency regulations to ensure safety under different transport conditions. The physical state of spent fuel and the fuel rod cladding as well as the geometric configuration of fuel assemblies are important inputs for the evaluation of package capabilities under these conditions. In this paper, the mechanical behavior of high burn-up spent fuel assemblies (> approx. 50 GWd/tHM, value averaged over the fuel assembly) under transport conditions is analyzed with regard to the assumptions which are used in the containment and criticality safety analysis. In view of the complexity of the interactions between the fuel rods as well as between the fuel assemblies, basket, and cask containment, the exact mechanical analysis of such phenomena is nearly impossible. Additionally, the gaps in information concerning the material properties of cladding and pellet behavior, especially for the high burn-up fuel, make the analysis more complicated. Considerations and knowledge gaps for the transport after extended interim storage are issues of growing interest. In this context, practical approaches are discussed based on the experience of BAM within the safety assessment of packages approved for transport of spent nuclear fuel.

Prospective Cohort Analysis of DRG Stimulation for Failed Back Surgery Syndrome Pain Following Lumbar Discectomy

INTRODUCTION

Surgical lumbar discectomy is a commonly performed routine spinal procedure that is usually undertaken to alleviate lumbar radicular symptoms caused by a herniated intervertebral disc. Surgical lumbar discectomy can also lead to chronic postsurgical leg and/or back pain (failed back surgery syndrome [FBSS]), a condition that can be refractory to conventional medical management. Early clinical results on the use of dorsal root ganglion (DRG) stimulation for FBSS have supported the use of this treatment alternative.

METHODS

A multicenter, single-arm, observational cohort study enrolled patients who had chronic pain following surgical lumbar discectomy, had failed conservative treatments, and reported pain intensity of at least 6 out of 10 in the primary region of pain. Data were collected on pain, quality of life, disability, and mood at baseline and through 12 months.

RESULTS

Thirteen patients underwent a trial of DRG stimulation; 11 (84.6%; 95% confidence interval = 57.8% to 95.7%) had good outcomes and underwent permanent device placement. Pain was reduced from a score of 8.64 (±0.92) at baseline to 2.40 (±2.38; n = 9) after 12 months of treatment, a 72.05% average reduction (P < 0.001). Similar improvements were observed across the secondary clinical measures, and safety data were in line with published rates.

DISCUSSION

These results suggest that DRG stimulation induces pain relief in subjects diagnosed with FBSS. These reductions in pain were also associated with improvements in quality of life and disability. Additional prospective studies are warranted to further investigate this potential application of DRG stimulation, as well as to optimize patient selection, lead placement, and programming strategies.

Therapy-Related Explants After Spinal Cord Stimulation: Results of an International Retrospective Chart Review Study

Objectives

Clinical trials of spinal cord stimulation (SCS) have largely focused on conversion from trial to permanent SCS and the first years after implant. This study evaluates the association of type of SCS and patient characteristics with longer‐term therapy‐related explants.

Materials and Methods

Implanting centers in three European countries conducted a retrospective chart review of SCS systems implanted from 2010 to 2013. Ethics approval or waiver was obtained, and informed consent was not required. The chart review recorded implants, follow‐up visits, and date and reasons for any explants through mid‐2016. Results are presented using Cox regression to determine factors associated with explant for inadequate pain relief.

Results

Four implanting centers in three countries evaluated 955 implants, with 8720 visits over 2259 years of follow‐up. Median age was 53 years; 558 (58%) were female. Explant rate was 7.9% per year. Over half (94 of 180) of explants were for inadequate pain relief, including 32/462 (6.9%) of implants with conventional nonrechargeable SCS, 37/329 (11.2%) with conventional rechargeable and 22/155 (14.2%) with high‐frequency (10 kHz) rechargeable SCS. A higher explant rate was found in univariate regression for conventional rechargeable (HR 1.98, p = 0.005) and high‐frequency stimulation (HR 1.79, p = 0.035) than nonrechargeable SCS. After covariate adjustment, the elevated explant rate persisted for conventional rechargeable SCS (HR 1.95, p = 0.011), but was not significant for high‐frequency stimulation (HR 1.71, p = 0.069).

Conclusions

This international, real‐world study found higher explant rates for conventional rechargeable and high‐frequency SCS than nonrechargeable systems. The increased rate for conventional rechargeable stimulation persisted after covariate adjustment.

Hygiene guideline for the planning, installation, and operation of ventilation and air-conditioning systems in health-care settings - Guideline of the German Society for Hospital Hygiene (DGKH)

Since the publication of the first "Hospital Hygiene Guideline for the implementation and operation of air conditioning systems (HVAC systems) in hospitals" (http://www.krankenhaushygiene.de/informationen/fachinformationen/leitlinien/12) in 2002, it was necessary due to the increase in knowledge, new regulations, improved air-conditioning systems and advanced test methods to revise the guideline. Based on the description of the basic features of ventilation concepts, its hygienic test and the usage-based requirements for ventilation, the DGKH section "Ventilation and air conditioning technology" attempts to provide answers for the major air quality issues in the planning, design and the hygienically safe operation of HVAC systems in rooms of health care.

[Safe reprocessing of medical devices with a view of the entire process chain. Recommendations of the VDI 5700 guidelines]

The reprocessing of medical devices for low pathogen or sterile use is in itself potentially risky even though the aim of reprocessing is the avoidance of hygienic or technically functional risks. The methodological principles of risk management for medical devices are described in the standard DIN EN ISO 14971. The recommendations of the Commission for Hospital Hygiene and Infectious Disease Prevention (Kommission für Krankenhaushygiene und Infektionsprävention KRINKO) of the Robert Koch Institute (RKI) and the Federal Institute for Drugs and Medical Devices (Bundesinstituts für Arzneimittel und Medizinprodukte BfArM) "hygiene requirements for the reprocessing of medical devices" clarify numerous reprocessing-specific risks and are structured with reference to the different steps of reprocessing. The aim was a practical combination of the normative risk management methodology with the process-oriented KRINKO/BfArM recommendations, which has provided an interdisciplinary group of experts moderated by the Association of German Engineers (VDI). The main contents of the VDI 5700 guidelines on "hazards associated with the reprocessing--risk management in the reprocessing of medical devices--measures for risk control" and the process of the development of these guidelines is described.

Cost-effectiveness of minimal interventional procedures for chronic mechanical low back pain: design of four randomised controlled trials with an economic evaluation

BACKGROUND

Minimal interventional procedures are frequently applied in patients with mechanical low back pain which is defined as pain presumably resulting from single sources: facet, disc, sacroiliac joint or a combination of these. Usually, these minimal interventional procedures are an integral part of a multidisciplinary pain programme. A recent systematic review issued by the Dutch Health Insurance Council showed that the effectiveness of these procedures for the total group of patients with chronic low back pain is yet unclear and cost-effectiveness unknown. The aim of the study is to evaluate whether a multidisciplinary pain programme with minimal interventional procedures is cost-effective compared to the multidisciplinary pain programme alone for patients with chronic mechanical low back pain who did not respond to conservative primary care and were referred to a pain clinic.

METHODS

All patients with chronic low back pain who are referred to one of the 13 participating pain clinics will be asked to participate in an observational study. Patients with a suspected diagnosis of facet, disc or sacroiliac joint problems will receive a diagnostic block to confirm this diagnosis. If confirmed, they will be asked to participate in a randomized controlled trial (RCT). For each single source a separate RCT will be conducted. Patients with a combination of facet, disc or sacroiliac joint problems will be invited for participation in a RCT as well. An economic evaluation from a societal perspective will be performed alongside these four RCTs. Patients will complete questionnaires at baseline, 3 and 6 weeks, 3, 6, 9 and 12 months after start of the treatment. Costs will be collected using self-completed cost questionnaires.

DISCUSSION

No trials are yet available which have evaluated the cost-effectiveness of minimal interventional procedures in patients with chronic mechanical low back pain, which emphasizes the importance of this study.

TRIAL REGISTRATION NUMBER

National Trial Register: NTR3531.

Time trends of mercury in feathers of West Greenland birds of prey during 1851-2003

Temporal trends of mercury (Hg) in West Greenland gyrfalcons, peregrine falcons, and white-tailed eagles were determined over 150 years from 1851 to 2003. Hg was measured in the fifth primary feather. Results showed that Hg increased in the order gyrfalcon (lowest) < peregrine falcon (intermediate) < white-tailed eagle (highest). All species showed significant age accumulations, which were taken into account in the temporal trend analysis. Of eight time trend analyses (three species and three age groups of which one was missing), seven showed an increase in primary feather concentrations. Of these, four were significant at the 5% level, two were close to being significant, and one was not significant. The linear regressions of which three out of four showed significant increases were for juvenile and immature gyrfalcon and juvenile peregrine falcon, which covered only periods prior to 1960, owing to limited data from the last half-century. The two sample comparisons of Hg 10-year medians for adult peregrine falcons and juvenile and adult white-tailed eagles indicated a continued increase during recent decades. However, low levels of Hg in a few recent collections among gyrfalcons and peregrines could indicate a change in the increasing trend.

Effect of chronic nonmalignant pain on highway driving performance

Most pain patients are treated in an outpatient setting and are engaged in daily activities including driving. Since several studies showed that cognitive functioning may be impaired in chronic nonmalignant pain, the question arises whether or not chronic nonmalignant pain affects driving performance. Therefore, the objective of the present study was to determine the effects of chronic nonmalignant pain on actual highway driving performance during normal traffic. Fourteen patients with chronic nonmalignant pain and 14 healthy controls, matched on age, educational level, and driving experience, participated in the study. Participants performed a standardized on-the-road driving test during normal traffic, on a primary highway. The primary parameter of the driving test is the Standard Deviation of Lateral Position (SDLP). In addition, driving-related skills (tracking, divided attention, and memory) were examined in the laboratory. Subjective assessments, such as pain intensity, and subjective driving quality, were rated on visual analogue scales. The results demonstrated that a subset of chronic nonmalignant pain patients had SDLPs that were higher than the matched healthy controls, indicating worse highway driving performance. Overall, there was a statistically significant difference in highway driving performance between the groups. Further, chronic nonmalignant pain patients rated their subjective driving quality to be normal, although their ratings were significantly lower than those of the healthy controls. No significant effects were found on the laboratory tests.

Mortality Factors, Environmental Contaminants, and Parasites of White-Tailed Sea Eagles from Greenland

Twelve white-tailed sea eagles (Haliaeetus albicilla groenlandicus) found dead between 1997 and 2000 in Greenland were examined to investigate the health status, including the causes of death and the burden of organochlorine contaminants and potentially toxic heavy metals. The determined causes of death were unspecific trauma (n = 6), lead poisoning (n = 2) with 36 and 26 ppm lead in the liver tissue, infectious diseases (n = 1), injuries sustained during intraspecific conflict (n = 1), and gunshot (n = 1). One lead poisoned eagle had a single lead shot pellet in its gizzard. No diagnosis could be made in one case because of decomposition of the carcass. Four of the investigated eagles were injured with lead shot or bullet fragments; one of the birds was killed with about 69 lead shots. Levels of organochlorine pesticides, polychlorinated biphenyls, mercury, and cadmium in organs were moderate. The parasite fauna consisted of one coccidian and three helminth species. The acanthocephalas Profiliocollis botulus and Corynosoma suduche as well as the nematode Stegophorus stellaepolaris are all new records for the white-tailed sea eagle.

Paravertebral blockade for minor breast surgery

Paravertebral blockade (PVB) has been advocated as a useful technique for breast surgery. We prospectively compared the efficacy of PVB via a catheter technique with the efficacy of general anesthesia (GA) for minor breast surgery. Thirty patients were randomized into two groups to receive either PVB or GA. Variables of efficacy were postoperative pain measured on a visual analog scale, postoperative nausea and vomiting (PONV), recovery time, and patient satisfaction. Postoperative visual analog scale scores in the PVB group were significantly lower in the early postoperative period (maximum, 12 vs 45 mm; P < 0.01). In both groups, PONV was nearly absent. There was no difference in recovery time. Patient satisfaction was better in the PVB group (2.8 vs 2.3; scale, 0-3; P < 0.01). There was one inadvertent epidural block and one inadvertent pleural puncture in the PVB group. Although PVB resulted in better postoperative pain relief, the advantages over GA were marginal in this patient group because postoperative pain was relatively mild and the incidence of PONV was small. Considering that the technique has a certain complication rate, we conclude that at present the risk/benefit ratio of PVB does not favor routine use for minor breast surgery.

IMPLICATIONS

This study confirms the previously reported superior pain relief after paravertebral blockade (PVB) for breast surgery. However, considering the relatively mild postoperative pain and therefore the limited advantage of PVB for these patients, the risk/benefit ratio does not favor the routine use of PVB for minor breast surgery.

Stroking parameters in top level swimmers with a disability

PURPOSE

The purposes of this study were to analyze velocity (V), stroke length (SL), and stroke rate (SR) values during the 100-m freestyle competitive events in top level male and female swimmers with a disability (DS) according to the international Functional Classification System (FCS) and to compare the results obtained with those of able-bodied swimmers (ABS).

METHODS

DS (N = 119) and ABS (N = 32) were tested in real competitive conditions during European and French swimming championships in the A finals of the 100-m freestyle.

RESULTS

V and SL increased significantly (P < 0.01) according to the level of ability from class S3 up to S10. SL values were significantly different (P < 0.01) between males and females in each class group. On the contrary, SR was not significantly different between genders, between each class group of FCS, and also with ABS. The major result of this study was that stroke length was related to velocity whereas stroke rate was not. The differences in weekly training time between each class of DS were not significantly different and showed that performances seemed to be more related to the various locomotor disabilities than to the training status.

CONCLUSIONS

These findings, which are discussed, showed that stroke index (SI = V.SL) could be used as a sensitive criterion to assess the swimmer with a disability in relationship to his classification level.

Swimming performances and stroking parameters in non skilled grammar school pupils: relation with age, gender and some anthropometric characteristics

OBJECTIVE

It was hypothesized that swimming velocity (V) and stroking parameters such as stroke length (SL), stroke rate (SR) and stroke index (SI) are influenced by age, gender, and some anthropometric characteristics.

EXPERIMENTAL DESIGN

Cross-sectional study.

SETTING

Grammar school pupils from French schools.

PARTICIPANTS

One thousand and ninety-seven males and 961 females non skilled swimmers aged from 11 to 17.

INTERVENTIONS

Usual swimming sessions (6 +/- 2 h.year-1) during a physical education program at school.

MEASURES

V, SL, SF and SI (SI = V.SL) were measured or calculated from a 50-m crawl sprint and height, arm span and body mass were measured for all subjects.

RESULTS

The results showed that V, SL and SI increased regularly (p < 0.01) in relation to age in both genders. SL was never significantly different between males and females. SF remained unchanged according to age and was significantly higher in males than in females. V, SL and SI were influenced by age and arm span but not SF.

CONCLUSIONS

As males and females were submitted to the same swimming teaching program at school, a higher increase in muscle power and anaerobic capacity in males could explain the gender differences. These results observed in non skilled swimmers showed that the differences in stroking parameters between genders were the reverse of those of top level swimmers and that they can be used by swimming teachers in order to build some assessment tools and to better understand the improvements in swimming in relation to growth and gender.

Surgical treatment of liver injury with an absorbable mesh: an experimental study

Uncontrollable bleeding remains a life-threatening problem in severe liver injury. The application of an absorbable mesh has been reported in a small number of patients. To evaluate an absorbable mesh wrap in standardized conditions, we performed an experimental study in 14 female pigs. A standard liver laceration imitating a blunt injury grade IV (Liver Injury Scale of the American Association for the Surgery of Trauma) was made in all animals. Heparin was administered to mimic coagulopathy. After randomization, seven animals received a polyglycolic acid (Vicryl) mesh wrap to control bleeding. Seven animals served as controls. Six of seven animals with a mesh wrap survived. Six of seven animals in the control group died (p = 0.02, Fisher's exact test). Intrahepatic pressures in the treated group varied from 3 to 55 mm Hg. Liver function tests in surviving animals were temporarily elevated. Necropsy at 2 weeks demonstrated adhesions to the wrapped lobe, but no hematoma, free bile, or abscess. Histologic examination showed a foreign-body reaction to the mesh and necrotic parts in the liver. It is concluded that an absorbable mesh wrap can effectively control bleeding from severe liver injury and improve survival in an animal model, although it may cause some damage to liver tissue.