Johannes T. A. Knape

Radiofrequency denervation of lumbar facet joints in the treatment of chronic low back pain: a randomized, double-blind, sham lesion-controlled trial.

Objectives:Radiofrequency facet joint denervation procedures have been common practice for 2 decades in treatment of chronic low back pain. We designed this multicenter, randomized, double-blind, sham treatment controlled trial to determine the efficacy of radiofrequency facet joint denervation, as it is routinely performed. Methods:Inclusion criteria were low back pain, duration more than 6 months, and ≥50% Visual Analog Scale (VAS) reduction on diagnostic block. Exclusion criteria were prior radiofrequency treatment, radicular syndrome, coagulopathies, specific allergies, cancer, and pregnancy. A total of 81 out of 462 patients were randomized to undergo radiofrequency facet joint denervation or sham treatment. The first evaluation was carried out 3 months after treatment. Primary outcome was determined with a combined outcome measure comprising VAS, physical activities, and analgesic intake, from a twice-weekly recorded diary. Secondary outcome measures were the separate diary parameters, global perceived effect (complete relief, >50% relief, no effect, pain increase), and SF-36 Quality of Life Questionnaire. Results:There were no dropouts before the first evaluation. The combined outcome measure showed no differences between radio- frequency facet joint denervation (n = 40; success 27.5%) and sham (n = 41; success 29.3%) (P = 0.86). The VAS in both groups improved (P < 0.001). Global perceived effect improved after radiofrequency facet joint denervation (P < 0.05). The other secondary outcome parameters showed no significant differences. Relevant costs were evaluated. Discussion:The combined outcome measure and VAS showed no difference between radiofrequency and sham, though in both groups, significant VAS improvement occurred. The global perceived effect was in favor of radiofrequency. In selected patients, radiofrequency facet joint denervation appears to be more effective than sham treatment.

The effect of outpatient preoperative evaluation of hospital inpatients on cancellation of surgery and length of hospital stay.

To evaluate the possible effects of outpatient preoperative evaluation (OPE) for new surgical patients who will be inpatients, we conducted an observational study at a university hospital in The Netherlands. Various outcomes before and after the introduction of an OPE clinic were compared. The study population comprised all 21,553 elective adult inpatients operated on between January 1, 1997 and December 31, 1999. Cardiac surgery, obstetric and pediatric patients, and patients operated on in same-day surgery were excluded. The main outcome measures were surgical cases canceled for medical reasons, rate of same-day admissions (who were expected to increase), and length of hospital stay. After introduction of OPE, the rate of cancellations for medical reasons decreased from 2.0% to 0.9% (adjusted odds ratio 0.7, 95% CI, 0.5–0.9). The rate of same-day admissions increased from 5.3% before to 7.7% after OPE introduction (adjusted odds ratio 1.2, 95% CI, 1.01–1.39), and the total hospital length of stay (in days) significantly decreased by a factor of 0.92 (0.90–0.94), which was partly the result of a reduction in preoperative admission time. We concluded that, although smaller than anticipated, the use of OPE for potential inpatients leads to a significant reduction of cancelled cases and of length of admission. Further increase of these benefits from OPE requires changes in institutional policy, such as forcing surgical departments to increase their number of same-day admissions.

Platelet-rich plasma preparation using three devices: Implications for platelet activation and platelet growth factor release

Background: In this study, three commercial systems for the preparation of platelet-rich plasma (PRP) were compared and platelet growth factors release was measured. Methods: Ten healthy volunteers donated whole blood that was fractionated by a blood cell separator, and a table-top centrifuge to prepare PRP. Furthermore, an autologous growth factor filter was used to concentrate PRP fractionated by the blood cell separator. PRP was subsequently activated with autologously produced thrombin to degranulate the platelets to measure platelet-derived growth factor-AB (PDGF-AB), transforming growth factor-beta (TGF-β), insulin-like growth factor-1 (IGF-1), and vascular endothelial growth factor (VEGF). Results: PRP contained significantly higher platelet counts compared with baseline values (p < 0.001). PDGF-AB concentrations were increased more than 18-fold in the platelet gel supernatant when the cell-separator and GPS were used, whereas only a 3-fold increase was seen with the AGF. Conclusion: The three PRP devices enable the preparation of PRP for the release of high concentrations of platelet growth factor, but showed different harvesting capacities for the collection of concentrated platelets. The administration of thrombin for PRP activation resulted in the release of high concentrations of PDGF-AB and TGF-β but only when PRP had not been activated during the preparation process in vitro.

Heart displacement during off-pump CABG: how well is it tolerated?

BACKGROUND Heart displacement during off-pump coronary artery bypass grafting (CABG) is necessary to expose the anastomosic sites. We analyzed the hemodynamic changes in relation to the grafted arteries. METHODS The relationship between surgical exposure and hemodynamic management was assessed in 150 consecutive patients undergoing off-pump CABG utilizing the Octopus Tissue Stabilization System (Medtronic, Minneapolis, MN). RESULTS Surgical exposure by anterolateral thoracotomy showed no significant hemodynamic changes. Through sternotomy, stroke volume was significantly reduced by dislocation at all target sites: by 6% at the left anterior descending artery (LAD), 25% at the diagonal branch artery (D), 14% at the right coronary artery (RCA), and 21% at the obtuse marginal artery (OM). The application of head-down positioning (LAD, 56%; D, 74%; RCA, 90%; OM, 96%) increased not only surgical exposure but also preload, producing correction of ventricular filling pressures and output. In a minority of cases, dopamine (3 to 5 microg x kg(-1) x min(-1)) was added to maintain baseline hemodynamic values (LAD, 5%; D, 15%; RCA, 7%; OM, 28%). CONCLUSIONS Revascularization during anterolateral thoracotomy was uneventful. The sternotomy approach with heart displacement induced right heart compression. Mainly fluid redistribution was sufficient to correct cardiac output. Once stabilized, systemic circulation remained unchanged during revascularization.

Radiofrequency lesioning of dorsal root ganglia for chronic lumbosacral radicular pain: a randomised, double-lind, controlled trial

BACKGROUND Results of observational studies have shown pain reduction with percutaneous radiofrequency lesioning of dorsal root ganglia for lumbosacral radicular pain, but there are few randomised controlled trials. We aimed to assess the efficacy of radiofrequency lesioning of dorsal root ganglia for lumbosacral radicular pain. METHODS We screened 1001 patients, who were mostly referred by their family doctor, in four hospitals for a double-blind randomised trial. 83 patients met inclusion criteria and thus were randomly assigned to receive a radiofrequency lesion or control treatment of the involved dorsal root ganglion. Control treatment was done in the same way as radiofrequency lesioning, but without radiofrequency current. Preoperatively and during 3-month follow-up, patients reported visual analogue leg-pain and back-pain scores, physical impairment, and use of analgesics in a diary. Primary outcome was success or failure of treatment, defined by a multidimensional decision rule, which included median outcome variables from the diary. Post-hoc analysis for possible covariate interference with outcome variables was done. Primary outcome data were analysed on an intention-to-treat basis. FINDINGS 45 patients were assigned radiofrequency lesioning and 38 control treatment. Three patients dropped out before 3 months. After 3 months, seven (16%) of 44 patients treated with radiofrequency lesioning and nine (25%) of 36 in the control group had successful treatment (difference -9.1% [95% CI -33.0 to 12.0], p=0.43). No differences between groups in side-effects were seen. INTERPRETATION Lumbosacral radiofrequency lesioning of dorsal root ganglia failed to show advantage over control treatment with local anaesthetics. Thus, its use as routine treatment in lumbosacral radicular pain should not be advocated.

Resuscitation skills of lay public after recent training

STUDY OBJECTIVE To investigate the ability of laypeople to apply basic CPR techniques after recent training. DESIGN Cross-sectional assessment of practical CPR skills. TYPE OF PARTICIPANTS 151 laypeople who were trained twice in the preceding 20 to 24 months. MEASUREMENTS AND MAIN RESULTS Practical skills were tested using six primary recorded variables that describe the quality of CPR techniques in a training situation. A total score on the skills of each participant was computed on the basis of a predefined scoring system. Thirty-three percent of the participants were able to perform adequate CPR. The compression:relaxation ratio, the breathing volume, and the breathing interval were points of concern. CONCLUSION Practical skills in basic CPR after a 12-month training interval, though better in this study than in many previous studies, are insufficient in the majority of laypeople. The results of this study could be used to design a better tailored (re)instruction program, with an emphasis on regular, frequent refresher courses.

The use of autologous platelet-leukocyte gels to enhance the healing process in surgery, a review

BackgroundThe therapeutic use of autologously prepared, platelet–leukocyte-enriched gel (PLG) is a relatively new technology for the stimulation and acceleration of soft tissue and bone healing. The effectiveness of this procedure lies in the delivery of a wide range of platelet growth factors mimicking the physiologic wound healing and reparative tissue processes. Despite an increase in PLG applications, the structures and kinetics of this autogenously derived biologic material have not been observed.MethodsA review of the most recent literature was performed to evaluate the use of PLG in various surgical disciplines.ResultsThe review showed that the application of PLG has been extended to various surgical disciplines including orthopedics, cardiac surgery, plastic and maxillofacial surgery, and recently also endoscopic surgery.ConclusionThis review demonstrates the usefulness of PLG in a wide range of clinical applications for improvement of healing after surgical procedures.

The Octopus Study: Rationale and Design of Two Randomized Trials on Medical Effectiveness, Safety, and Cost-Effectiveness of Bypass Surgery on the Beating Heart

The Octopus Study consists of two multicenter randomized clinical trials in which coronary artery bypass grafting on the beating heart (off-pump CABG) using the Utrecht Octopus Method is compared to intracoronary stent implantation and conventional CABG. The primary endpoint in the comparison of off-pump CABG versus stent implantation (OctoStent Trial) is medical effectiveness (i.e., absence of reintervention and major adverse cardiac and cerebrovascular events at 1 year after treatment). The primary endpoint in the comparison of off-pump CABG versus conventional CABG (OctoPump Trial) is cerebral safety (i.e., absence of cognitive deficits and cerebrovascular events at 3 months after treatment). Secondary endpoints in both trials include presence and severity of angina, quality of life, exercise capacity, and cost-effectiveness. A total of 560 patients will be enrolled. A random sample of 210 patients will undergo repeat angiography at 1 year to assess angiographic restenosis rate and graft patency. Including 1-year follow-up, the study will last for 3 years. Control Clin Trials 2000;21:595-609

Reviewing the structural features of autologous platelet-leukocyte gel and suggestions for use in surgery.

The therapeutic use of autologously prepared platelet-leukocyte gel (PLG) is a relatively new technology which might stimulate and accelerate soft-tissue and bone healing. The effectiveness of this procedure lies in the exogenous delivery of a wide range of platelet growth factors, intentionally released from autologously prepared PLG. The rationale to employ this technique is to mimic physiological wound healing and reparative tissue processes. Despite an increase in clinical PLG applications, the structures and kinetics of this biological material have not been completely examined. Electron microscopic imaging was performed to evaluate platelet-leukocyte gel structures. Furthermore, directions for PLG application are presented, based on results from published articles in various surgical disciplines. In conclusion, PLG can be useful in a wide range of clinical applications to enhance healing following surgical procedures, since exogenous applied PLG releases instantly platelet growth factors, in the presence of leukocytic cells.

Large-dose intrathecal sufentanil prevents the hormonal stress response during major abdominal surgery: a comparison with intravenous sufentanil in a prospective randomized trial.

We studied the effect of large-dose intrathecal sufentanil (ITS) for major abdominal surgery on the hormonal stress response. Forty patients were randomly allocated to receive either IV sufentanil (IVS) or 150 &mgr;g of ITS as part of general anesthesia. In the IVS group, adrenocorticotropic hormone (ACTH) and cortisol concentrations were larger than baseline and the ITS group, 60 min after incision and at skin closure. Plasma concentrations of cortisol and ACTH were not different from baseline in the ITS group during surgery. Six hours after skin closure, cortisol concentrations were larger than baseline in both groups. Twenty-four and 48 h after skin closure, ACTH and cortisol values were similar between groups. Norepinephrine concentrations increased after surgery in both groups. Blood glucose levels increased in both groups during and after surgery. Pain scores and morphine consumption during the first 48 h after surgery were lower in the ITS group. The data show that large-dose ITS prevents the intraoperative hormonal stress response in comparison with balanced anesthesia. We speculate that this is due to the highly specific binding of sufentanil to spinal and supraspinal receptors. This technique improves postoperative analgesia when compared with balanced anesthesia.