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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 -
Europace : European Pacing,... Apr 2023
Topics: Humans; Atrial Fibrillation; Phrenic Nerve; Echocardiography; Pericardium
PubMed: 37061851
DOI: 10.1093/europace/euad054 -
Acta Medica Okayama Dec 2018We studied phrenic nerve conduction times in 90 phrenic nerves of 45 normal subjects. The phrenic nerve was stimulated at the posterior border of the sternomastoid...
We studied phrenic nerve conduction times in 90 phrenic nerves of 45 normal subjects. The phrenic nerve was stimulated at the posterior border of the sternomastoid muscle in the supraclavicular fossa, just above the clavicle, with bipolar surface electrodes. For recording, positive and negative electrodes were placed on the xiphoid process and at the eighth intercostal bone-cartilage transition, respectively. We studied both the right and left sides to determine whether there was any difference between the two sides. The mean onset latency (± SD) of the right compound muscle action potentials (CMAPs) (5.99±0.39 msec) was significantly shorter than that of the left CMAPs (6.45±0.50 msec). The mean peak latency was significantly shorter in the right CMAPs (10.22±1.33 msec) than the left CMAPs (12.48±2.02 msec). The mean (± SD) amplitude was significantly lower in the left CMAPs (0.42±0.11 mV) than the right CMAPs (0.49±0.10 mV). The difference between the length of the nerve on the right and left sides might have affected the difference in latency between the two sides.
Topics: Adult; Humans; Male; Neural Conduction; Phrenic Nerve; Young Adult
PubMed: 30573910
DOI: 10.18926/AMO/56373 -
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 -
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 -
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 -
Scientific Reports Aug 2018Communicating fibres between the phrenic nerve and sympathetic nervous system may exist, but have not been characterized histologically and immunohistochemically, even...
Communicating fibres between the phrenic nerve and sympathetic nervous system may exist, but have not been characterized histologically and immunohistochemically, even though increased sympathetic activity due to phrenic nerve stimulation for central sleep apnoea may entail morbidity and mortality. We, therefore, conducted a histological study of the phrenic nerve to establish the presence of catecholaminergic fibres throughout their course. The entire phrenic nerves of 35 formalin-fixed human cadavers were analysed morphometrically and immunohistochemically. Furthermore, the right abdominal phrenic nerve was serially sectioned and reconstructed. The phrenic nerve contained 3 ± 2 fascicles in the neck that merged to form a single fascicle in the thorax and split again into 3 ± 3 fascicles above the diaphragm. All phrenic nerves contained catecholaminergic fibres, which were distributed homogenously or present as distinct areas within a fascicle or as separate fascicles. The phrenicoabdominal branch of the right phrenic nerve is a branch of the celiac plexus and, therefore, better termed the "phrenic branch of the celiac plexus". The wall of the inferior caval vein in the diaphragm contained longitudinal strands of myocardium and atrial natriuretic peptide-positive paraganglia ("caval bodies") that where innervated by the right phrenic nerve.
Topics: Abdomen; Autonomic Pathways; Diaphragm; Female; Humans; Male; Neck; Phrenic Nerve; Thorax
PubMed: 30076368
DOI: 10.1038/s41598-018-30145-x -
European Journal of Cardio-thoracic... Apr 2016The importance of phrenic nerve preservation during pneumonectomy remains controversial. We previously demonstrated that preservation of the phrenic nerve in the...
OBJECTIVES
The importance of phrenic nerve preservation during pneumonectomy remains controversial. We previously demonstrated that preservation of the phrenic nerve in the immediate postoperative period preserved lung function by 3-5% but little is known about its long-term effects. We, therefore, decided to investigate the effect of temporary ipsilateral cervical phrenic nerve block on dynamic lung volumes in mid- to long-term pneumonectomy patients.
METHODS
We investigated 14 patients after a median of 9 years post pneumonectomy (range: 1-15 years). Lung function testing (spirometry) and fluoroscopic and/or sonographic assessment of diaphragmatic motion on the pneumonectomy side were performed before and after ultrasonographic-guided ipsilateral cervical phrenic nerve block by infiltration with lidocaine.
RESULTS
Ipsilateral phrenic nerve block was successfully achieved in 12 patients (86%). In the remaining 2 patients, diaphragmatic motion was already paradoxical before the nerve block. We found no significant difference on dynamic lung function values (FEV1 'before' 1.39 ± 0.44 vs FEV1 'after' 1.38 ± 0.40; P = 0.81).
CONCLUSIONS
Induction of a temporary diaphragmatic palsy did not significantly influence dynamic lung volumes in mid- to long-term pneumonectomy patients, suggesting that preservation of the phrenic nerve is of greater importance in the immediate postoperative period after pneumonectomy.
Topics: Adult; Aged; Female; Humans; Lung; Male; Middle Aged; Nerve Block; Organ Sparing Treatments; Phrenic Nerve; Pneumonectomy; Postoperative Complications
PubMed: 26405235
DOI: 10.1093/ejcts/ezv334 -
Neurology India 2022To report a new patient friendly and convenient technique for phrenic nerve conduction with alternative sites of stimulation and recording.
OBJECTIVE
To report a new patient friendly and convenient technique for phrenic nerve conduction with alternative sites of stimulation and recording.
METHODS
Phrenic nerve conduction was performed in forty volunteers and ten patients of peripheral neuropathy. Active recording electrode was placed in tenth intercostal space 2.5 cm away from para-spinal muscles (mid-scapular line), reference electrode in eighth intercostal space just medial to subcostal margin with ground between stimulating and recording electrode. Stimulation was done at the level of crico-thyroid space near or under the posterior margin of sternocleidomastoid muscle. This new method was compared with existing ones.
ANALYSIS
Data was analysed using SPSS 23 version. Correlation between height, weight, body mass index, age, and chest expansion was done using bi-variate correlation. Mean latency and amplitude of the study method were compared with other methods using MANNOVA test.
RESULTS
Total of forty subjects were studied. Thirty-seven were male subjects. Mean age was 28.03 ± 9.63 years, height 168.0 ± 9.60 cm and chest expansion 3.53 ± 0.64 cm. Right sided phrenic nerve mean latency was 5.99 ± 0.629 ms and amplitude 1.088 ± 0.178 mV. Left sided phrenic nerve conductions showed mean latency of 6.02 ± 1.82 ms, amplitude of 1.092 ± 0.2912 mV. These standard deviations were smaller than what were observed with other methods suggesting increased consistency of our results. There was no correlation between phrenic nerve conduction with age, height, gender or chest expansion.
CONCLUSION
This study method gave a better as well as consistent morphology, higher amplitude and required lower amount of current strength. It was superior to previously reported methods in consistency of normative data.
Topics: Adolescent; Adult; Female; Humans; Male; Young Adult; Action Potentials; Back; Electrodes; Electromyography; Neck; Neural Conduction; Neurologic Examination; Peripheral Nervous System Diseases; Phrenic Nerve
PubMed: 36412357
DOI: 10.4103/0028-3886.360904