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Journal of Visualized Experiments : JoVE Oct 2021Peripheral nerve interfaces are frequently used in experimental neuroscience and regenerative medicine for a wide variety of applications. Such interfaces can be...
Peripheral nerve interfaces are frequently used in experimental neuroscience and regenerative medicine for a wide variety of applications. Such interfaces can be sensors, actuators, or both. Traditional methods of peripheral nerve interfacing must either tether to an external system or rely on battery power that limits the time frame for operation. With recent developments of wireless, battery-free, and fully implantable peripheral nerve interfaces, a new class of devices can offer capabilities that match or exceed those of their wired or battery-powered precursors. This paper describes methods to (i) surgically implant and (ii) wirelessly power and control this system in adult rats. The sciatic and phrenic nerve models were selected as examples to highlight the versatility of this approach. The paper shows how the peripheral nerve interface can evoke compound muscle action potentials (CMAPs), deliver a therapeutic electrical stimulation protocol, and incorporate a conduit for the repair of peripheral nerve injury. Such devices offer expanded treatment options for single-dose or repeated dose therapeutic stimulation and can be adapted to a variety of nerve locations.
Topics: Animals; Electric Power Supplies; Electric Stimulation Therapy; Peripheral Nerves; Phrenic Nerve; Prostheses and Implants; Rats; Wireless Technology
PubMed: 34747395
DOI: 10.3791/63085 -
Annals of Anatomy = Anatomischer... Jun 2024The aim of this systematic review is to study the subdiaphragmatic anatomy of the phrenic nerve. (Review)
Review
OBJECTIVE
The aim of this systematic review is to study the subdiaphragmatic anatomy of the phrenic nerve.
MATERIALS AND METHODS
A computerised systematic search of the Web of Science database was conducted. The key terms used were phrenic nerve, subdiaphragmat*, esophag*, liver, stomach, pancre*, duoden*, intestin*, bowel, gangli*, biliar*, Oddi, gallbladder, peritone*, spleen, splenic, hepat*, Glisson, falciform, coronary ligament, kidney, suprarenal, and adrenal. The 'cited-by' articles were also reviewed to ensure that all appropriate studies were included.
RESULTS
A total of one thousand three hundred and thirty articles were found, of which eighteen met the inclusion and exclusion criteria. The Quality Appraisal for Cadaveric Studies scale revealed substantial to excellent methodological quality of human studies, while a modified version of the Systematic Review Centre for Laboratory Animal Experimentation Risk of Bias Tool denoted poor methodological quality of animal studies. According to human studies, phrenic supply has been demonstrated for the gastro-esophageal junction, stomach, celiac ganglia, liver and its coronary ligament, inferior vena cava, gallbladder and adrenal glands, with half of the human samples studied presenting phrenic nerve connections with any subdiaphragmatic structure.
CONCLUSIONS
This review provides the first systematic evidence of subdiaphragmatic phrenic nerve supply and connections. This is of interest to professionals who care for people suffering from neck and shoulder pain, as well as patients with peridiaphragmatic disorders or hiccups. However, there are controversies about the autonomic or sensory nature of this supply.
Topics: Phrenic Nerve; Humans; Diaphragm; Animals
PubMed: 38692333
DOI: 10.1016/j.aanat.2024.152269 -
Anesthesiology May 2022Strong spontaneous inspiratory efforts can be difficult to control and prohibit protective mechanical ventilation. Instead of using deep sedation and neuromuscular...
BACKGROUND
Strong spontaneous inspiratory efforts can be difficult to control and prohibit protective mechanical ventilation. Instead of using deep sedation and neuromuscular blockade, the authors hypothesized that perineural administration of lidocaine around the phrenic nerve would reduce tidal volume (VT) and peak transpulmonary pressure in spontaneously breathing patients with acute respiratory distress syndrome.
METHODS
An established animal model of acute respiratory distress syndrome with six female pigs was used in a proof-of-concept study. The authors then evaluated this technique in nine mechanically ventilated patients under pressure support exhibiting driving pressure greater than 15 cm H2O or VT greater than 10 ml/kg of predicted body weight. Esophageal and transpulmonary pressures, electrical activity of the diaphragm, and electrical impedance tomography were measured in pigs and patients. Ultrasound imaging and a nerve stimulator were used to identify the phrenic nerve, and perineural lidocaine was administered sequentially around the left and right phrenic nerves.
RESULTS
Results are presented as median [interquartile range, 25th to 75th percentiles]. In pigs, VT decreased from 7.4 ml/kg [7.2 to 8.4] to 5.9 ml/kg [5.5 to 6.6] (P < 0.001), as did peak transpulmonary pressure (25.8 cm H2O [20.2 to 27.2] to 17.7 cm H2O [13.8 to 18.8]; P < 0.001) and driving pressure (28.7 cm H2O [20.4 to 30.8] to 19.4 cm H2O [15.2 to 22.9]; P < 0.001). Ventilation in the most dependent part decreased from 29.3% [26.4 to 29.5] to 20.1% [15.3 to 20.8] (P < 0.001). In patients, VT decreased (8.2 ml/ kg [7.9 to 11.1] to 6.0 ml/ kg [5.7 to 6.7]; P < 0.001), as did driving pressure (24.7 cm H2O [20.4 to 34.5] to 18.4 cm H2O [16.8 to 20.7]; P < 0.001). Esophageal pressure, peak transpulmonary pressure, and electrical activity of the diaphragm also decreased. Dependent ventilation only slightly decreased from 11.5% [8.5 to 12.6] to 7.9% [5.3 to 8.6] (P = 0.005). Respiratory rate did not vary. Variables recovered 1 to 12.7 h [6.7 to 13.7] after phrenic nerve block.
CONCLUSIONS
Phrenic nerve block is feasible, lasts around 12 h, and reduces VT and driving pressure without changing respiratory rate in patients under assisted ventilation.
Topics: Acute Lung Injury; Animals; Critical Illness; Disease Models, Animal; Female; Humans; Lidocaine; Phrenic Nerve; Respiration, Artificial; Respiratory Distress Syndrome; Respiratory Mechanics; Swine; Tidal Volume
PubMed: 35348581
DOI: 10.1097/ALN.0000000000004161 -
Europace : European Pacing,... Apr 2023
Topics: Humans; Atrial Fibrillation; Phrenic Nerve; Echocardiography; Pericardium
PubMed: 37061851
DOI: 10.1093/europace/euad054 -
Medicines (Basel, Switzerland) Jan 2022In cardiac surgery, patients are at risk of phrenic nerve injury, which leads to diaphragm dysfunction and acute respiratory failure. Diaphragm dysfunction (DD) is... (Review)
Review
In cardiac surgery, patients are at risk of phrenic nerve injury, which leads to diaphragm dysfunction and acute respiratory failure. Diaphragm dysfunction (DD) is relatively frequent in cardiac surgery and particularly affects patients after coronary artery bypass graft. The onset of DD affects patients' prognosis in term of weaning from mechanical ventilation and hospital length of stay. The authors present a narrative review about diaphragm physiology, techniques used to assess diaphragm function, and the clinical application of diaphragm ultrasound in patients undergoing cardiac surgery.
PubMed: 35049938
DOI: 10.3390/medicines9010005 -
Journal of Clinical Medicine May 2023Patients with pre-existing pulmonary conditions are at risk for experiencing perioperative complications and increased morbidity. General anesthesia has historically... (Review)
Review
Patients with pre-existing pulmonary conditions are at risk for experiencing perioperative complications and increased morbidity. General anesthesia has historically been used for shoulder surgery, though regional anesthesia techniques are increasingly used to provide anesthesia and improved pain control after surgery. Relative to regional anesthesia, patients who undergo general anesthesia may be more prone to risks of barotrauma, postoperative hypoxemia, and pneumonia. High-risk pulmonary patients, in particular, may be exposed to these risks of general anesthesia. Traditional regional anesthesia techniques for shoulder surgery are associated with high rates of phrenic nerve paralysis which significantly impairs pulmonary function. Newer regional anesthesia techniques have been developed, however, that provide effective analgesia and surgical anesthesia while having much lower rates of phrenic nerve paralysis, thereby preserving pulmonary function.
PubMed: 37240589
DOI: 10.3390/jcm12103483 -
Circulation. Arrhythmia and... Jun 2022Phrenic nerve palsy is a well-known complication of cardiac ablation, resulting from the application of direct thermal energy. Emerging pulsed field ablation (PFA) may...
BACKGROUND
Phrenic nerve palsy is a well-known complication of cardiac ablation, resulting from the application of direct thermal energy. Emerging pulsed field ablation (PFA) may reduce the risk of phrenic nerve injury but has not been well characterized.
METHODS
Accelerometers and continuous pacing were used during PFA deliveries in a porcine model. Acute dose response was established in a first experimental phase with ascending PFA intensity delivered to the phrenic nerve (n=12). In a second phase, nerves were targeted with a single ablation level to observe the effect of repetitive ablations on nerve function (n=4). A third chronic phase characterized assessed histopathology of nerves adjacent to ablated cardiac tissue (n=6).
RESULTS
Acutely, we observed a dose-dependent response in phrenic nerve function including reversible stunning (R=0.965, <0.001). Furthermore, acute results demonstrated that phrenic nerve function responded to varying levels of PFA and catheter proximity placements, resulting in either: no effect, effect, or stunning. In the chronic study phase, successful isolation of superior vena cava at a dose not predicted to cause phrenic nerve dysfunction was associated with normal phrenic nerve function and normal phrenic nerve histopathology at 4 weeks.
CONCLUSIONS
Proximity of the catheter to the phrenic nerve and the PFA dose level were critical for phrenic nerve response. Gross and histopathologic evaluation of phrenic nerves and diaphragms at a chronic time point yielded no injury. These results provide a basis for understanding the susceptibility and recovery of phrenic nerves in response to PFA and a need for appropriate caution in moving beyond animal models.
Topics: Animals; Atrial Fibrillation; Catheter Ablation; Peripheral Nerve Injuries; Phrenic Nerve; Pulmonary Veins; Swine; Vena Cava, Superior
PubMed: 35649121
DOI: 10.1161/CIRCEP.121.010127 -
Journal of Neurophysiology Jan 2023Phrenic motoneurons (PhrMNs) innervate diaphragm myofibers. Located in the ventral gray matter (lamina IX), PhrMNs form a column extending from approximately the third... (Review)
Review
Phrenic motoneurons (PhrMNs) innervate diaphragm myofibers. Located in the ventral gray matter (lamina IX), PhrMNs form a column extending from approximately the third to sixth cervical spinal segment. Phrenic motor output and diaphragm activation are impaired in many neuromuscular diseases, and targeted delivery of drugs and/or genetic material to PhrMNs may have therapeutic application. Studies of phrenic motor control and/or neuroplasticity mechanisms also typically require targeting of PhrMNs with drugs, viral vectors, or tracers. The location of the phrenic motoneuron pool, however, poses a challenge. Selective PhrMN targeting is possible with molecules that move retrogradely upon uptake into phrenic axons subsequent to diaphragm or phrenic nerve delivery. However, nonspecific approaches that use intrathecal or intravenous delivery have considerably advanced the understanding of PhrMN control. New opportunities for targeted PhrMN gene expression may be possible with intersectional genetic methods. This article provides an overview of methods for targeting the phrenic motoneuron pool for studies of PhrMNs in health and disease.
Topics: Rats; Animals; Rats, Sprague-Dawley; Motor Neurons; Gene Transfer Techniques; Diaphragm; Phrenic Nerve
PubMed: 36416447
DOI: 10.1152/jn.00432.2022 -
Bioelectronic Medicine 2019Hemorrhagic shock (HS), a major cause of early death from trauma, accounts for around 40% of mortality, with 33-56% of these deaths occurring before the patient reaches... (Review)
Review
Hemorrhagic shock (HS), a major cause of early death from trauma, accounts for around 40% of mortality, with 33-56% of these deaths occurring before the patient reaches a medical facility. Intravenous fluid therapy and blood transfusions are the cornerstone of treating HS. However, these options may not be available soon after the injury, resulting in death or a poorer quality of survival. Therefore, new strategies are needed to manage HS patients before they can receive definitive care. Recently, various forms of neuromodulation have been investigated as possible supplementary treatments for HS in the prehospital phase of care. Here, we provide an overview of neuromodulation methods that show promise to treat HS, such as vagus nerve stimulation, electroacupuncture, trigeminal nerve stimulation, and phrenic nerve stimulation and outline their possible mechanisms in the treatment of HS. Although all of these approaches are only validated in the preclinical models of HS and are yet to be translated to clinical settings, they clearly represent a paradigm shift in the way that this deadly condition is managed in the future.
PubMed: 32232106
DOI: 10.1186/s42234-019-0033-z -
International Journal of Surgery Case... Feb 2022Peripheral neuronal sheath tumors are rare lesions that can arise from the lining of the neuronal axons of any nerve in the body. Schwannomas are usually solitary and...
INTRODUCTION AND IMPORTANCE
Peripheral neuronal sheath tumors are rare lesions that can arise from the lining of the neuronal axons of any nerve in the body. Schwannomas are usually solitary and encapsulated, slow growing, predominantly benign, with a malignant transformation rate of less than 2% and very low recurrence. The phrenic nerve schwannoma is rare in the neck and usually is asymptomatic.
CASE PRESENTATION
We present a case of a phrenic nerve schwannoma as an incidental intraoperative finding in the study of a patient with a cervical mass of progressive growth on the right side of the neck in contact with the anterior scalene muscle and pain intermittent. Resection of the mass was done with preservation of the endoneurium. Intraoperative stimulation after resection had a proper functionality of the phrenic nerve. In the follow-up, the patient had not any damage of the function of the phrenic nerve.
CLINICAL DISCUSSION
This tumor is generated by a deficiency of merlin with the consequent cell proliferation. The diagnostic imaging (CT or MRI) are the studies of choice. The differential diagnosis of these lesions has an impact on the presence or absence of oncological disease or progression of a previously treated one. The ideal management is surgical and the anatomical and/or functional preservation of the nerve depend of the tumor infiltration.
CONCLUSION
The phrenic nerve schwannoma is rare in the neck. The ideal management is surgical, and this pathology must be considered in patients with masses in the Station IV and supraclavicular fossa of the neck.
PubMed: 35101715
DOI: 10.1016/j.ijscr.2022.106783