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Phrenic nerve stimulation is currently being investigated for the prevention of diaphragm atrophy in patients with mechanically supported breathing. Patients receiving breathing support from mechanical ventilation are at risk of mismatches between respiratory demand and ventilator support. Our objectives were to determine if a novel phrenic nerve stimulation device provided stimulation during inspiration as intended and did not exacerbate any potential discordances. A benchtop electromechanical simulation model was developed to validate phrenic nerve stimulation with simulated breathing. The phrenic nerve stimulation device was evaluated with a mechanical ventilator attached to a breathing simulator. The trigger ratio and time lag between phrenic nerve stimulation and mechanical ventilation was measured for multiple disease and ventilator parameters. For the 1:1 breath trigger ratio test, 99.79% of intended stimulation breaths received stimulation at the correct time. For the 1:4 breath trigger ratio test, 99.72% of intended stimulation breaths received stimulation at the correct time. For trigger lag times for the inspiratory and expiratory phases, the mean inspiratory lag was 36.10 ± 10.50 ms and 16.61 ± 3.61 ms, respectively. The following discordance scenarios were evaluated in conjunction with simulated phrenic nerve stimulation: asynchrony-false trigger, dyssynchrony-early trigger, dyssynchrony-late trigger, dyssynchrony-early cycling, dyssynchrony-late cycling. Testing demonstrated none of these discordances were exacerbated by the simulated phrenic nerve stimulation. The novel phrenic nerve stimulation device delivered electrical stimulation therapy as intended and did not exacerbate any simulated discordances.

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INTRODUCTION: A retrospective review of a consecutive case series of 66 permanent spinal cord stimulation implants utilizing a novel tissue fixation device was performed. The purpose of this case series review is to examine the impact of a novel lead anchor to tissue fixation system and determine if it is a viable alternative to standard tissue fixation methods. CASE SERIES REPORT: Sixty-six cases were performed utilizing a novel method of lead anchor tissue fixation. Cases performed included cervical and thoracolumbar. For the majority of the 66 cases, two spinal cord stimulator leads and two SwiftLock lead anchors in conjunction with the novel method of tissue fixation were utilized. RESULTS: A retrospective review indicated no reports of lead migration during this case series, the mean follow-up time being 38 weeks (range 10-68 weeks). In addition, there were zero reported complications or untoward effects due to use of the novel device and technique. DISCUSSION: Overall complication rates for SCS have been reported in the range of 30-40%, with hardware-related complications contributing a significant percentage to the overall complication rate. Lead anchoring techniques still rely heavily on the experience and skill of the implanting physician. The novel device and method utilized in this case series to aid in anchoring leads demonstrated good results with no observed postoperative complications. CONCLUSION: These data suggest this novel method of tissue fixation may be a viable alternative for fixation of spinal cord stimulator leads to soft tissue. In this case series there were no reported incidents of migration or complications related to the novel device.

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STUDY DESIGN: In vitro comparative, laboratory experiments. OBJECTIVE: This study developed a laboratory apparatus that measured resistance to failure using pressures similar to intradiscal pressure of a lumbar spinal disk. Various combinations of an anular repair device were compared. SUMMARY OF BACKGROUND CONTEXT: Herniated material of the intervertebral disk is removed during a lumbar discectomy; however, the defect in the anulus fibrosus remains and can provide a pathway for future herniation. Repairing the anulus fibrosus could mitigate this reherniation and improve patient outcomes. METHODS: A pneumatic cylinder was used to increase the pressure of a sealed chamber until artificial nucleus pulposus material was expulsed through either a 3-mm circular (diameter) or a 6-mm slit anular defect created in a surrogate anulus fibrosus. Each unrepaired condition was compared with 3 repaired conditions using a commercially available soft tissue repair system. The repaired conditions included: (1) a single tension band; (2) 2 tension bands in a cruciate pattern; or (3) 2 tension bands in a parallel pattern. Maximum pressure at the point of extrusion of the internal chamber material and failure or nonfailure of the repair was measured. RESULTS: Significant differences were detected (P<0.05) in maximum failure pressures for the nonrepaired (control) versus repaired conditions. With 1 or 2 tension bands repairing the circular defect, the maximum failure pressure increased by approximately 76% and 131%, respectively. In addition, the failure pressure for 2 tension bands in either a cruciate or parallel configuration was not different, and was approximately 32% higher (P<0.05) than a single tension band in the case of the circular defect. Similar results were seen for the slit defect, with the exception that no difference between the repaired conditions (ie, single vs. 2 tension bands) was detected. CONCLUSIONS: This laboratory simulation demonstrated that repairing the anulus fibrosus after a discectomy procedure can be beneficial for retaining intradiscal material. The use of 2 tension bands, versus a single tension band, in either a cruciate or parallel configuration may further improve the ability to retain disk material.

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INTRODUCTION: Spinal cord stimulation is a well-established treatment for chronic neuropathic pain of the trunk or limbs. Currently, the standard method of fixation is to affix the leads of the neuromodulation device to soft tissue, fascia or ligament, through the use of manually tying general suture. A novel semiautomated device is proposed that may be advantageous to the current standard. Comparison testing in an excised caprine spine and simulated bench top model was performed. MATERIALS AND METHODS: Three tests were performed: 1) perpendicular pull from fascia of caprine spine; 2) axial pull from fascia of caprine spine; and 3) axial pull from Mylar film. Six samples of each configuration were tested for each scenario. Standard 2-0 Ethibond was compared with a novel semiautomated device (Anulex fiXate). Upon completion of testing statistical analysis was performed for each scenario. RESULTS: For perpendicular pull in the caprine spine, the failure load for standard suture was 8.95 lbs with a standard deviation of 1.39 whereas for fiXate the load was 15.93 lbs with a standard deviation of 2.09. For axial pull in the caprine spine, the failure load for standard suture was 6.79 lbs with a standard deviation of 1.55 whereas for fiXate the load was 12.31 lbs with a standard deviation of 4.26. For axial pull in Mylar film, the failure load for standard suture was 10.87 lbs with a standard deviation of 1.56 whereas for fiXate the load was 19.54 lbs with a standard deviation of 2.24. CONCLUSIONS: These data suggest a novel semiautomated device offers a method of fixation that may be utilized in lieu of standard suturing methods as a means of securing neuromodulation devices. Data suggest the novel semiautomated device in fact may provide a more secure fixation than standard suturing methods.

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INTRODUCTION: Spinal cord stimulation is a well-established treatment for recalcitrant pain syndromes such as failed back surgery syndrome. Techniques minimizing surgical time and incision size and increasing lead stability are of great value to both the patient and implanting physician. We present a consecutive case series review of ten permanent percutaneous spinal cord implants utilizing a novel lead fixation device. The purpose of this case series review is to present initial findings of the minimized incision size and thoughts surrounding the new device and technique. CASE SERIES REPORT: Ten cases were performed utilizing the new device (fiXate) and technique. Incision size was dictated by adequate visualization of the fascial stratum as well as technical working space required for lead fixation and redirection to the generator pocket. Each spinal cord stimulator lead was affixed to the thoracodorsal fascia utilizing the novel device. DISCUSSION: In this consecutive series, the average midline incision size was 2.2 cm (range = 1.9-2.6 cm) which is greatly minimized through the use of the device. Not only may fiXate directly affect incision size, operating room and anesthesia time may also be lessened due to the semiautomated nature of the device. Of the cases performed, there were no complications or adverse events. Of note, there have been no reports of lead migrations during this case series, the average follow-up time being 18 weeks (range 11-26 weeks). CONCLUSION: These data suggest a new method of fixation can be utilized for percutaneous spinal cord stimulation that allows a reduction in incision size. Intuitively, reduction in incision size is relevant with regard to tissue morbidity and may also have implications with regard to infection. Use of the device may also reduce operating room and anesthesia time as well as provide greater stability than standard suture.

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