Restoration of function in the paralyzed diaphragm (original) (raw)
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Surgical Anatomy of the Accessory Phrenic Nerve
The Annals of Thoracic Surgery, 2006
Background. Reports place the frequency of phrenic nerve injury after cardiac operations between 10% and 85%, emphasizing the importance of an accurate anatomic description of the diaphragm's innervating nerves to reduce iatrogenic injury, length of hospitalization, and associated costs. The aim of our study was to explore the anatomic variations of the accessory phrenic nerve and relate these findings to phrenic nerve injury.
Annals of Plastic Surgery, 2020
A patient affected by a voluminous synovial sarcoma of mediastinum received radical surgery, resulting in injury of both phrenic nerves. Because of the cancer location, reconstruction of the left phrenic nerve was not possible, so to prevent the patient's ventilator dependence, the right phrenic nerve was reconstructed via an autograft from the residual proximal stump of the contralateral one. In 3 months, the right hemidiaphragm function showed a full recovery, documented by ultrasonographic and radiographic assessment of diaphragmatic excursion, and the patient was weaned from mechanical ventilation. When a nerve autograft is indicated, the sural nerve still remains the criterion standard, because of the low morbidity of the donor site and ease of harvesting; however, in particular situations, such as in this unique case, the choice of an orthotopic graft may offer promising results.
PLoS ONE, 2013
Respiratory dysfunction is the leading cause of mortality following upper cervical spinal cord injury (SCI). Reinnervation of the paralyzed diaphragm via an anastomosis between phrenic nerve and a donor nerve is a potential strategy to mitigate ventilatory deficits. In this study, anastomosis of vagus nerve (VN) to phrenic nerve (PN) in rabbits was performed to assess the potential capacity of the VN to compensate for lost PN inputs. At first, we compared spontaneous discharge pattern, nerve thickness and number of motor fibers between these nerves. The PN exhibited a highly rhythmic discharge while the VN exhibited a variable frequency discharge pattern. The rabbit VN had fewer motor axons (105.3612.1 vs. 268.1615.4). Nerve conduction and respiratory function were measured 20 weeks after left PN transection with or without left VN-PN anastomosis. Compared to rabbits subjected to unilateral phrenicotomy without VN-PN anastomosis, diaphragm muscle action potential (AP) amplitude was improved by 292%, distal latency by 695%, peak inspiratory flow (PIF) by 22.6%, peak expiratory flow (PRF) by 36.4%, and tidal volume by 21.8% in the anastomosis group. However, PIF recovery was only 28.0%, PEF 28.2%, and tidal volume 31.2% of Control. Our results suggested that VN-PN anastomosis is a promising therapeutic strategy for partial restoration of diaphragm reinnervation, but further modification and improvements are necessary to realize the full potential of this technique.
Journal of Applied Physiology, 2021
This was the first (to our knowledge) implanted porcine model of phrenic nerve injury with a detailed multidimensional analysis of different degrees of diaphragmatic paralysis (unilateral and bilateral). Noninvasive thoracoabdominal volume and asynchrony assessment was shown to be useful in estimating the extent of diaphragmatic dysfunction and the consequent coordinated reorganization of nondiaphragmatic respiratory muscles. High level of pressure support ventilation was proved to obscure the interaction and compensation of respiratory muscles to deal with phrenic nerve injury.
Surgical neurology international, 2017
Unilateral diaphragmatic paralysis (UDP) can be a very disabling, typically causing shortness of breath and reduced exercise tolerance. We present a case of a surgical decompression of the phrenic nerve of a patient who presented with UDP, which occurred following cervical spine surgery. The workup for the etiology of UDP demonstrated paradoxical movement on "sniff test" and notably impaired pulmonary function tests. Seven months following the onset of the UDP, he underwent a surgical decompression of the phrenic nerve at the level of the anterior scalene. He noted rapid symptomatic improvement following surgery and reversal of the above noted objective findings was documented. At his 4-year follow-up, he had complete resolution of his clinical symptoms. Repeated physiologic testing of his respiratory function had shown a complete reversal of his UDP. Anatomical compression of the phrenic nerve by redundant neck vasculature should be considered in the differential diagnosi...
Journal of neurosurgery. Spine, 2018
OBJECTIVE Respiratory dysfunction is the leading cause of mortality following upper cervical spinal cord injury (SCI). The authors' previous study suggested that vagus nerve (VN) and phrenic nerve (PN) anastomosis could partially improve respiratory function in rabbits that had been subjected to PN transection. As a branch of the VN and a motor fiber-dominated nerve, the recurrent laryngeal nerve (RLN) seems a better choice to anastomose with the PN for respiratory function restoration after upper cervical SCI. This study was designed to determine whether RLN-PN anastomosis could restore the respiratory function after upper cervical SCI in rabbits. METHODS Twelve male New Zealand rabbits were randomly divided into 3 groups: 1) sham group (no injury), 2) transection group (right RLN and PN were transected), and 3) bridge group (transected right RLN and PN were immediately anastomosed). Spontaneous discharges of the RLN and PN were compared using a bio-signal collection system. RL...
Phrenic Nerve Pacing in a Tetraplegic Patient via Intramuscular Diaphragm Electrodes
American Journal of Respiratory and Critical Care Medicine, 2002
In patients with ventilator-dependent tetraplegia, phrenic nerve ventilatory support by this technique, in a previously ventipacing (PNP) provides significant clinical advantages compared lator-dependent tetraplegic patient. with mechanical ventilation. This technique however generally requires a thoracotomy with its associated risks and in-patient hospital METHODS stay and carries some risk of phrenic nerve injury. We have devel-This investigation was approved by the Investigational Review Boards oped a method by which the phrenic nerves can be activated via at University Hospitals of Cleveland, Ohio, MetroHealth Medical Cenintramuscular diaphragm electrodes. In one patient with ventilatorter, the Veterans Administration Hospital, and also the Food and Drug dependent tetraplegia, two intramuscular diaphragm electrodes Administration. Informed consent was obtained before enrollment in were implanted into each hemidiaphragm near the phrenic nerve the study. motor points via laparoscopic surgery. The motor points were iden-T.C., a 35-year-old male, suffered a cervical spinal cord injury (C2 tified employing a previously devised mapping technique. Because level) after a diving accident that resulted in tetraplegia and dependence inspired volumes were suboptimal on the right, a second laparoon mechanical ventilatory support. Phrenic nerve conduction studies scopic procedure was necessary to position electrodes near the anteindicated normal bilateral phrenic nerve function (7). rior and posterior branches of the right phrenic nerve. During bilat-Standard laparoscopic techniques were employed to place intramuseral stimulation, inspired volume was 580 ml. After a reconditioning cular diaphragm electrodes within the muscular tissue of the diaphragm. program of progressively increasing diaphragm pacing, maximum After placement of four trocars into the abdominal wall and developinspired volumes on the left and right hemidiaphragms increased ment of a pneumoperitoneum (Figure 1), a previously devised mapping significantly. Maximum combined bilateral stimulation was 1120 procedure (8, 9) (see online data supplement) was performed to determl. Importantly, the patient has been able to comfortably tolerate mine the phrenic nerve motor points, i.e., the area of the muscle confull-time pacing. If confirmed in additional patients, PNP with intratained within the space defined by the entrance points of the phrenic muscular diaphragm electrodes via laparoscopic surgery may pronerves into the diaphragm (Figure 2). Initially, several test sites were vide a less invasive and less costly alternative to conventional PNP. evaluated in the general region of the motor point with a suction electrode, which could be reversibly applied to the diaphragm. At each Keywords: spinal cord injury; diaphragm pacing; laparoscopy test site, a recruitment curve was constructed by determining the magnitude of change in intra-abdominal pressure (Validyne Eng. Corp.,