SARS-CoV-2 entry sites are present in all structural elements of the human glossopharyngeal and vagal nerves: clinical implications

Severe acute respiratory syndrome coronavirus (SARS-CoV-2) infections result in the temporary loss of smell and taste (anosmia and dysgeusia) in about one third of confirmed cases. Several investigators have reported that the viral spike protein receptor is present in olfactory neurons. However, no study has been published to date showing the presence of viral entry sites angiotensin-converting enzyme 2 (ACE2), neuropilin1 (NRP1), and TMPRSS2, the serine protease necessary for priming the viral proteins, in human nerves that are responsible for taste sensation (cranial nerves: VII, IX and X). We used immunocytochemistry to examine three postmortem donor samples of the IXth (glossopharyngeal) and Xth (vagal) cranial nerves where they leave/join the medulla from three donors to confirm the presence of ACE2, NRP1 and TMPRSS2. Two samples were paraffin embedded; one was a frozen sample. In addition to staining sections from the latter, we isolated RNA from it, made cDNA, and performed PCR to confirm the presence of the mRNAs that encode the proteins visualized. All three of the proteins required for SARS-CoV-2 infections appear to be present in the human IXth and Xth nerves near the medulla. Direct infection of these nerves by the COVID-19 virus is likely to cause the loss of taste experienced by many patients. In addition, potential viral spread through these nerves into the adjacent brainstem respiratory centers might also aggravate the respiratory problems patients are experiencing.

V-OG03 Robotic Epiphrenic Diverticulectomy, Myotomy And Hiatus Hernia Repair

Background Oesophageal epiphrenic diverticulum’s are rare; reported in less than 0.5 per cent of the population. They are noted however in 1–3 per cent of patients complaining of dysphagia. They are almost always associated with a motility disorder of the oesophagus. Surgery is generally the only solution to help with the symptoms of dysphagia and reflux. Methods This video highlights a case of a moderate sized diverticulum causing dysphagia and significant reflux. The procedure was performed on the DaVinci X system; to my knowledge, this is the first time this technique has been performed on the DaVinci X in the UK. A 4 arm technique was used, utilising two right arms and one left. Instruments used were cadiere forceps, hook and sureform stapler. The 12 mm port was docked with arm 3 and sited on the patients left. A stapled diverticulectomy was performed with the Sureform blue cartridge. An endoflex was used to retract the liver. Results The procedure was successfully performed in 150 minutes and involved resection of the diverticulum, hiatal repair and short myotomy up to the neck of the diverticulum. Conclusion The robotic platform allows for better visualisation of the hiatal structures and vagal nerves and the enhanced magnification make for a safer myotomy. The articulating instruments permit safer dissection of the diverticulum. A 4 arm technique makes the myotomy easier and safer to perform.

V-OG05 Robotic Hellers Myotomy

Background Achalasia is a rare condition affecting less than 1:100,000 patients. Treatment for this rare condition include balloon dilation, botox injection, endoscopic myotomy (POEMS) or surgical myotomy. Laparoscopic surgical myotomy is the “go to” approach for most surgeons; it is tried and tested, can be performed safely and quickly with a low complication rate, minimal pain and a short length of stay. Methods This video presents the technique adopted for robotic oesophageal myotomy in a patient with type II achalasia. A 4 arm technique was adopted with arm 4 on the patients left. The Davinci X system was used in this case. A Nathensen liver retractor was used to retract the liver; robotic instruments included the hook and cadiere forceps x2. Results The procedure was successfully performed; the operative time was 53 minutes, LOS was <24 hours. Check endoscopy revealed a wide open gastro-oesophageal junction and a long myotomy. The patient noted an improvement in symptoms with 24 hours and has had no significant reflux. Conclusion The enhanced magnified 3D view on the robotic platform allows better visualisation of the hiatal structures, vagal nerves and muscle fibres when performing the myotomy. Using the 4th arm to retract the lateral edge of the oesophageal muscle provides a very safe and stable platform to perform a long myotomy. I think the robotic system should be adopted as the standard approach for a hellers myotomy.

The Syndrome of Elongated Styloid Process, the Eagle’s Syndrome—From Anatomical, Evolutionary and Embryological Backgrounds to 3D Printing and Personalized Surgery Planning. Report of Five Cases

Background and Objectives: The symptoms of Eagle’s syndrome are associated with the elongated styloid process of the temporal bone or calcification of the stylohyoid ligament. The first mention of pain syndrome associated with the elongated styloid process dates back to 1937, when it was described by Watt Weems Eagle. Over the last decade, experts in the field have shown a lively interest in the issue of the relationship between the elongated styloid process and various symptoms. This article presents the correlation between the clinical signs of Eagle’s syndrome and alterations in surrounding anatomical structures. It includes a brief review of the evolutionary, embryological and clinical anatomical background of the elongated styloid process. Materials and Methods: Between 2018 and 2019, five patients were admitted to our workplace with 1–3-year history of bilateral or unilateral throat pain, otalgia and pharyngeal foreign body sensation. As a therapeutic novelty in the surgical approach to this condition, we used individual 3D printed models to measure and identify the exact location of the resection of the styloid process without damaging the surrounding anatomical structures, such as the facial, accessory, hypoglossal, and vagal nerves; the internal jugular vein; and the internal carotid artery. Results: Compared to traditional surgical methods without 3D models, 3D models helped to better identify cutting edges and major landmarks used in surgical treatment of Eagle’s syndrome. Printed models provided assistance with the exact location of the styloid process resection position without damaging the surrounding anatomical structures such as the facial, accessory, hypoglossal, and vagal nerves; the internal jugular vein; and the internal carotid artery. Conclusion: In our clinical report, we used 3D printed models for navigation and planning during surgical procedures involving resections of the elongated styloid process. Additionally, we can formulate a new hypothesis: the elongated styloid process is a form of atavism of the bony hyoid apparatus in our evolutionary ancestors that is evolutionarily encoded or arises from disrupted degeneration of the middle portion of embryonal Reichert´s cartilage of the second pharyngeal arch. Under normal conditions, this portion does not ossify but degenerates and transforms into a connective tissue band, the future stylohyoid ligament.

Testing the hypothesis of neurodegeneracy in respiratory network function with a priori transected arterially perfused brain stem preparation of rat

Degeneracy of respiratory network function would imply that anatomically discrete aspects of the brain stem are capable of producing respiratory rhythm. To test this theory we a priori transected brain stem preparations before reperfusion and reoxygenation at 4 rostrocaudal levels: 1.5 mm caudal to obex ( n = 5), at obex ( n = 5), and 1.5 ( n = 7) and 3 mm ( n = 6) rostral to obex. The respiratory activity of these preparations was assessed via recordings of phrenic and vagal nerves and lumbar spinal expiratory motor output. Preparations with a priori transection at level of the caudal brain stem did not produce stable rhythmic respiratory bursting, even when the arterial chemoreceptors were stimulated with sodium cyanide (NaCN). Reperfusion of brain stems that preserved the pre-Bötzinger complex (pre-BötC) showed spontaneous and sustained rhythmic respiratory bursting at low phrenic nerve activity (PNA) amplitude that occurred simultaneously in all respiratory motor outputs. We refer to this rhythm as the pre-BötC burstlet-type rhythm. Conserving circuitry up to the pontomedullary junction consistently produced robust high-amplitude PNA at lower burst rates, whereas sequential motor patterning across the respiratory motor outputs remained absent. Some of the rostrally transected preparations expressed both burstlet-type and regular PNA amplitude rhythms. Further analysis showed that the burstlet-type rhythm and high-amplitude PNA had 1:2 quantal relation, with burstlets appearing to trigger high-amplitude bursts. We conclude that no degenerate rhythmogenic circuits are located in the caudal medulla oblongata and confirm the pre-BötC as the primary rhythmogenic kernel. The absence of sequential motor patterning in a priori transected preparations suggests that pontine circuits govern respiratory pattern formation.