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Journal of Orthopaedic Surgery (Hong... 2023In complete brachial plexus injury, phrenic nerve (PN) is frequently used in neurotization for elbow flexion restoration. The advancement in video-assisted thoracoscopic... (Comparative Study)
Comparative Study Observational Study
BACKGROUND
In complete brachial plexus injury, phrenic nerve (PN) is frequently used in neurotization for elbow flexion restoration. The advancement in video-assisted thoracoscopic surgery (VATS) allows full-length PN dissection intrathoracically for direct coaptation to recipient without nerve graft.
PURPOSE
We report our experience in improving the surgical technique and its outcome.
METHODS
Seven patients underwent PN dissection via VATS and full-length transfer to musculocutaneous nerve (MCN) or motor branch of biceps (MBB) from June 2015 to June 2018. Comparisons were made with similar group of patients who underwent conventional PN transfer.
RESULTS
Mean age of patients was 21.9 years. All were males involved in motorcycle accidents who sustained complete brachial plexus injury. We found the elbow flexion recovery were earlier in full-length PN transfer. However, there was no statistically significant difference in elbow flexion strength at 3 years post-surgery.
CONCLUSION
We propose full-length PN transfer for restoration of elbow flexion in patients with delayed presentation.
Topics: Phrenic Nerve; Nerve Transfer; Elbow Joint; Thoracic Surgery, Video-Assisted; Prospective Studies; Humans; Male; Adolescent; Young Adult; Treatment Outcome
PubMed: 37256763
DOI: 10.1177/10225536231180330 -
Molecular Medicine (Cambridge, Mass.) Jun 2020In light of the present therapeutic situation in COVID-19, any measure to improve course and outcome of seriously affected individuals is of utmost importance. We recap... (Review)
Review
In light of the present therapeutic situation in COVID-19, any measure to improve course and outcome of seriously affected individuals is of utmost importance. We recap here evidence that supports the use of human recombinant erythropoietin (EPO) for ameliorating course and outcome of seriously ill COVID-19 patients. This brief expert review grounds on available subject-relevant literature searched until May 14, 2020, including Medline, Google Scholar, and preprint servers. We delineate in brief sections, each introduced by a summary of respective COVID-19 references, how EPO may target a number of the gravest sequelae of these patients. EPO is expected to: (1) improve respiration at several levels including lung, brainstem, spinal cord and respiratory muscles; (2) counteract overshooting inflammation caused by cytokine storm/ inflammasome; (3) act neuroprotective and neuroregenerative in brain and peripheral nervous system. Based on this accumulating experimental and clinical evidence, we finally provide the research design for a double-blind placebo-controlled randomized clinical trial including severely affected patients, which is planned to start shortly.
Topics: Betacoronavirus; Brain Stem; COVID-19; Coronavirus Infections; Cytokine Release Syndrome; Double-Blind Method; Erythropoietin; Humans; Lung; Neuroprotective Agents; Pandemics; Phrenic Nerve; Pneumonia, Viral; Proof of Concept Study; Randomized Controlled Trials as Topic; Recombinant Proteins; Respiratory Muscles; Respiratory System Agents; SARS-CoV-2; Severity of Illness Index; Spinal Cord
PubMed: 32546125
DOI: 10.1186/s10020-020-00186-y -
Experimental Neurology Apr 2021Although cervical spinal cord injury (cSCI) disrupts bulbo-spinal serotonergic projections, partial recovery of spinal serotonergic innervation below the injury site is... (Review)
Review
Although cervical spinal cord injury (cSCI) disrupts bulbo-spinal serotonergic projections, partial recovery of spinal serotonergic innervation below the injury site is observed after incomplete cSCI. Since serotonin contributes to functional recovery post-injury, treatments to restore or accelerate serotonergic reinnervation are of considerable interest. Intermittent hypoxia (IH) was reported to increase serotonin innervation near respiratory motor neurons in spinal intact rats, and to improve function after cSCI. Here, we tested the hypotheses that spontaneous serotonergic reinnervation of key respiratory (phrenic and intercostal) motor nuclei: 1) is partially restored 12 weeks post C2 hemisection (C2Hx); 2) is enhanced by IH; and 3) results from sprouting of spared crossed-spinal serotonergic projections below the site of injury. Serotonin was assessed via immunofluorescence in male Sprague Dawley rats with and without C2Hx (12 wks post-injury); individual groups were exposed to 28 days of: 1) normoxia; 2) daily acute IH (dAIH28: 10, 5 min 10.5% O2 episodes per day; 5 min normoxic intervals); 3) mild chronic IH (IH28-5/5: 5 min 10.5% O2 episodes; 5 min intervals; 8 h/day); or 4) moderate chronic IH (IH28-2/2: 2 min 10.5% O2 episodes; 2 min intervals; 8 h/day), simulating IH experienced during moderate sleep apnea. After C2Hx, the number of ipsilateral serotonergic structures was decreased in both motor nuclei, regardless of IH protocol. However, serotonergic structures were larger after C2Hx in both motor nuclei, and total serotonin immunolabeling area was increased in the phrenic motor nucleus but reduced in the intercostal motor nucleus. Both chronic IH protocols increased serotonin structure size and total area in the phrenic motor nuclei of uninjured rats, but had no detectable effects after C2Hx. Although the functional implications of fewer but larger serotonergic structures are unclear, we confirm that serotonergic reinnervation is substantial following injury, but IH does not affect the extent of reinnervation.
Topics: Animals; Cervical Cord; Cervical Vertebrae; Hypoxia; Intercostal Nerves; Male; Motor Neurons; Nerve Regeneration; Phrenic Nerve; Rats; Rats, Sprague-Dawley; Recovery of Function; Serotonin; Spinal Cord Injuries
PubMed: 33460645
DOI: 10.1016/j.expneurol.2021.113609 -
Clinical Anatomy (New York, N.Y.) Mar 2020The contribution of the left phrenic nerve to innervation of the esophagogastric junction. The esophagogastric junction is part of the barrier preventing...
The contribution of the left phrenic nerve to innervation of the esophagogastric junction. The esophagogastric junction is part of the barrier preventing gastroesophageal reflux. We have investigated the contribution of the phrenic nerves to innervation of the esophagogastric junction in humans and piglets by dissecting 30 embalmed human specimens and 14 piglets. Samples were microdissected and nerves were stained and examined by light and electron microscopy. In 76.6% of the human specimens, the left phrenic nerve participated in the innervation of the esophagogastric junction by forming a neural network together with the celiac plexus (46.6%) or by sending off a distinct phrenic branch, which joined the anterior vagal trunk (20%). Distinct left phrenic branches were always accompanied by small branches of the left inferior phrenic artery. In 10% there were indirect connections with a distinct phrenic nerve branch joining the celiac ganglion, from which celiac plexus branches to the esophagogastric junction emerged. Morphological examination of phrenic branches revealed strong similarities to autonomic celiac plexus branches. There was no contribution of the left phrenic nerve or accompanying arteries from the caudal phrenic artery in any of the piglets. The right phrenic nerve made no contribution in any of the human or piglet samples. We conclude that the left phrenic nerve in humans contributes to the innervation of the esophagogastric junction by providing ancillary autonomic nerve fibers. Experimental studies of the innervation in pigs should consider that neither of the phrenic nerves was found to contribute. Clin. Anat. 33:265-274, 2020. © 2019 Wiley Periodicals, Inc.
Topics: Aged; Aged, 80 and over; Anatomic Variation; Animals; Cadaver; Celiac Plexus; Esophagogastric Junction; Female; Humans; Male; Microscopy, Electron; Phrenic Nerve; Swine; Vagus Nerve
PubMed: 31625208
DOI: 10.1002/ca.23502 -
Folia Medica Cracoviensia Dec 2022The right phrenic nerve is vulnerable to injury (PNI) during cryoballoon ablation (CBA) isolation of the right pulmonary veins. The complication can be transient or... (Meta-Analysis)
Meta-Analysis
The right phrenic nerve is vulnerable to injury (PNI) during cryoballoon ablation (CBA) isolation of the right pulmonary veins. The complication can be transient or persistent. The reported incidence of PNI fluctuates from 4.73% to 24.7% depending on changes over time, CBA generation, and selected protective methods. M e t h o d s: Through September 2019, a database search was performed on MEDLINE, EMBASE, and Cochrane Database. In the selected articles, the references were also extensively searched. The study provides a comprehensive meta-analysis of the overall prevalence of PNI, assesses the transient to persistent PNI ratio, the outcome of using compound motor action potentials (CMAP), and estimated average time to nerve recovery. R e s u l t s: From 2008 to 2019, 10,341 records from 48 trials were included. Out of 783 PNI retrieved from the studies, 589 (5.7%) and 194 (1.9%) were persistent. CMAP caused a significant reduction in the risk of persistent PNI from 2.3% to 1.1% (p = 0.05; odds ratio [OR] 2.13) in all CBA groups. The mean time to PNI recovery extended beyond the hospital discharge was significantly shorter in CMAP group at three months on average versus non CMAP at six months (p = 0.012). CMAP (in contrast to non-CMAP procedures) detects PNI earlier from 4 to 16 sec (p <0.05; I2 = 74.53%) and 3 to 9o (p <0.05; I2 = 97.24%) earlier. C o n c l u s i o n s: Right PNI extending beyond hospitalization is a relatively rare complication. CMAP use causes a significant decrease in the risk of prolonged injury and shortens the time to recovery.
Topics: Humans; Action Potentials; Phrenic Nerve; Hospitalization; Odds Ratio; Peripheral Nerve Injuries
PubMed: 36854091
DOI: 10.24425/fmc.2022.144087 -
Cureus Apr 2024The article reviews the anatomical path of the phrenic nerve and its anastomoses, with the most up-to-date knowledge reported in the literature. We have briefly reviewed... (Review)
Review
The article reviews the anatomical path of the phrenic nerve and its anastomoses, with the most up-to-date knowledge reported in the literature. We have briefly reviewed the possible phrenic dysfunctions, with the final aim of presenting an osteopathic manual approach for the treatment of the most superficial portion of the nerve, using a gentle technique. The approach we propose is, therefore, a theory based on clinical experience and the rationale that we can extrapolate from the literature. We hope that the article will be a stimulus for further experimental investigations using the technique illustrated in the article. To the authors' knowledge, this is the first article that takes into consideration the hypothesis of an osteopathic treatment with gentle techniques for the phrenic nerve.
PubMed: 38606024
DOI: 10.7759/cureus.58012 -
Frontiers in Physiology 2020We previously reported NO/sGC signaling in the upper respiratory pathway, receiving input from the respiratory neurons of the brainstem to phrenic motoneurons in the...
We previously reported NO/sGC signaling in the upper respiratory pathway, receiving input from the respiratory neurons of the brainstem to phrenic motoneurons in the C3-C6 spinal cord. In order to assess whether innervation of the neuromuscular junction (NMJ) at the diaphragm is modulated by sGC/cGMP signaling, we performed unilateral 8-day continuous ligation of the phrenic nerve in rats. We examined sGCβ1 within the lower bulbospinal pathway (phrenic motoneurons, phrenic nerves and NMJs at the diaphragm) and the cGMP level in the contra- and ipsilateral hemidiaphragm. Additionally, we characterized the extent of phrenic nerve axonal degeneration and denervation at diaphragm NMJs. The results of our study show that continuous 8-day phrenic nerve ligation caused a marked increase in sGCβ1 (immunoreactivity and the protein level) in the ipsilateral phrenic motor pool. However, the protein sGCβ1 level in the phrenic nerve below its ligation and the cGMP level in the ipsilateral hemidiaphragm were evidently decreased. Using confocal analysis we discovered a reduction in sGCβ1-IR boutons/synaptic vesicles at the ipsilateral MNJs. These findings are consistent with the marked axonal loss (∼47%) and significant NMJs degeneration in the ipsilateral diaphragm muscle. The remarkable unilateral decrease in cGMP level in the diaphragm and the failure of EMG recordings in the ipsilateral hemidiaphragm muscle can be attributed to the fact that sGC is involved in transmitter release at the diaphragm NMJs via the sGC-cGMP pathway.
PubMed: 32655417
DOI: 10.3389/fphys.2020.00700 -
Annals of Biomedical Engineering Apr 2016The primary goal of this computational modeling study was to better quantify the relative distance of the phrenic nerves to areas where cryoballoon ablations may be...
The primary goal of this computational modeling study was to better quantify the relative distance of the phrenic nerves to areas where cryoballoon ablations may be applied within the left atria. Phrenic nerve injury can be a significant complication of applied ablative therapies for treatment of drug refractory atrial fibrillation. To date, published reports suggest that such injuries may occur more frequently in cryoballoon ablations than in radiofrequency therapies. Ten human heart-lung blocs were prepared in an end-diastolic state, scanned with MRI, and analyzed using Mimics software as a means to make anatomical measurements. Next, generated computer models of ArticFront cryoballoons (23, 28 mm) were mated with reconstructed pulmonary vein ostias to determine relative distances between the phrenic nerves and projected balloon placements, simulating pulmonary vein isolation. The effects of deep seating balloons were also investigated. Interestingly, the relative anatomical differences in placement of 23 and 28 mm cryoballoons were quite small, e.g., the determined difference between mid spline distance to the phrenic nerves between the two cryoballoon sizes was only 1.7 ± 1.2 mm. Furthermore, the right phrenic nerves were commonly closer to the pulmonary veins than the left, and surprisingly tips of balloons were further from the nerves, yet balloon size choice did not significantly alter calculated distance to the nerves. Such computational modeling is considered as a useful tool for both clinicians and device designers to better understand these associated anatomies that, in turn, may lead to optimization of therapeutic treatments.
Topics: Cryosurgery; Heart Atria; Humans; Magnetic Resonance Imaging; Models, Biological; Phrenic Nerve; Pulmonary Veins
PubMed: 26168718
DOI: 10.1007/s10439-015-1379-3 -
The Journal of Spinal Cord Medicine Jan 2023The implantation of commercially available phrenic nerve/diaphragm pacers has been available for more than 40 years and has enabled thousands of patients in over 40...
CONTEXT
The implantation of commercially available phrenic nerve/diaphragm pacers has been available for more than 40 years and has enabled thousands of patients in over 40 countries to achieve freedom from invasive mechanical ventilation.
OBJECTIVE
The cervical approach to implantation of these pacers is described, as are the pros and cons of using this technique compared to intrathoracic and sub-diaphragmatic.
METHODS
Study design was a retrospective review of 1,522 subjects from the Avery Biomedical Devices (ABD) database who were implanted with the Avery diaphragm pacer. Long term statistics from patients implanted with diaphragm pacers are presented as well.
RESULTS
17% of cervically placed electrodes required at least one replacement compared to 18% of electrodes placed thoracically. Devices implanted cervically show no significant difference in their longevity than those implanted using the thoracic approach (P value of 0.9382 using Two-Sample t-Test). The mean longevity for both approaches was found to be 6.4 years. The majority of electrodes implanted have never required replacement. A majority of CCHS patients were implanted using the thoracic approach and only find it necessary to use the device during sleeping hours. Most of the cervically implanted patients are found to be older at the time of implantation and implanted for diagnoses that require longer daily use of the device.
CONCLUSION
The cervical approach for the implantation of phrenic nerve/diaphragm pacers is the most minimally invasive, but underutilized, technique that allows for the use of local or monitored anesthesia, does not require entering any body cavities, and keeps incision size small.
Topics: Humans; Diaphragm; Spinal Cord Injuries; Respiration, Artificial; Phrenic Nerve; Prostheses and Implants; Electric Stimulation Therapy
PubMed: 34232840
DOI: 10.1080/10790268.2021.1940794 -
MethodsX 2019The phrenic nerve is useful to record as a motor output in studies investigating neural control of respiration. It may be accessed via dorsal or ventral microsurgical...
The phrenic nerve is useful to record as a motor output in studies investigating neural control of respiration. It may be accessed via dorsal or ventral microsurgical approaches. Since such studies frequently involve concurrent access to the spinal cord, the two approaches may be alternatively used, each with its own set of advantages and disadvantages. The dorsal approach permits easier exposure of the spinal cord via laminectomy, but, compared to the ventral approach, phrenic nerve access proves more challenging, and concurrent surgical access to the full complement of respiratory-related nerves (i.e., glossopharyngeal, vagus, recurrent laryngeal, hypoglossal nerves) and cervical sympathetic nerve in the neck is limited. The ventral approach achieves more direct access to the phrenic and respiratory-related nerves, but ventral access to the spinal cord via corpectomy requires much greater diligence and vigilance. Ventral spinal cord access, however, facilitates neuronal (e.g., phrenic motoneuron and interneuron) recordings in the ventral horn of the spinal cord, given greater proximity to the ventral compared to the dorsal surface of the spinal cord providing more leeway in recording pipette insertion point and trajectory. Additionally, ventral access to the cervical spinal cord proves useful across a broad range of studies investigating normal spinal cord physiology as well as spinal cord injury. We detail the microsurgical technique of concurrent ventral phrenic nerve dissection and cervical corpectomy in adult rats.
PubMed: 30766804
DOI: 10.1016/j.mex.2018.08.007