RESUMO
Background: The sympathetic nervous system inhibits human colonic motility largely by effects on enteric neurons. Noradrenergic axons, which branch extensively in the myenteric plexus, are integral to this modulatory role, but whether they contact specific types of enteric neurons is unknown. The purpose of this study was to determine the association of noradrenergic varicosities with types of enteric neurons. Methods: Human colonic tissue from seven patients was fixed and dissected prior to multi-layer immunohistochemistry for human RNA binding proteins C and D (HuC/D) (pan-neuronal cell body labelling), tyrosine hydroxylase (TH, catecholaminergic labelling), Enkephalin (ENK), choline acetyltransferase (ChAT, cholinergic labelling) and/or nitric oxide synthase (NOS, nitrergic labelling) and imaged using confocal microscopy. TH-immunoreactive varicose nerve endings and myenteric cell bodies were reconstructed as three dimensional digital images. Data was exported to a purpose-built software package which quantified the density of varicosities close to the surface of each myenteric cell body. Results: TH-immunoreactive varicosities had a greater mean density within 1 µm of the surface of ChAT +/NOS- nerve cell bodies compared with ChAT-/NOS + cell bodies. Similarly, ENK-immunoreactive varicosities also had a greater mean density close to ChAT +/NOS- cell bodies compared with ChAT-/NOS + cells. Conclusion: A method for quantifying close associations between varicosities and nerve cell bodies was developed. Sympathetic axons in the myenteric plexus preferentially target cholinergic excitatory cells compared to nitrergic neurons (which are largely inhibitory). This connectivity is likely to be involved in inhibitory modulation of human colonic motility by the sympathetic nervous system.
RESUMO
BACKGROUND: The laparoscopic approach is the preferred method for repair of large hiatus hernias but can be technically challenging. Training surgeons need experience as the primary operator to gain competency in this operation. However, learning the procedure should not compromise the functional long-term outcome for patients. The aim of this study was to determine whether any difference in long-term outcomes exists for patients having a laparoscopic large hiatus hernia repair performed by a trainee versus a consultant surgeon. METHODS: A total of 648 suitable patients who had undergone laparoscopic repair of a large hiatus hernia were identified from a prospective database. Cases were divided into two groups based on whether the primary operator was a trainee or a consultant surgeon. Demographics, perioperative data, revisions and patient-reported clinical outcomes via standardised questionnaires were compared. RESULTS: There were no statistically significant differences in the clinical outcomes for patients undergoing laparoscopic repair of a large hiatus hernia performed by a trainee versus a consultant surgeon, with comparable patient-reported outcomes for heartburn, dysphagia, and overall satisfaction with the outcome following surgery. Median operative time was approximately 20 min longer for trainees (p = <0.0001). Revisional surgery rates were similar for the two groups. CONCLUSIONS: Patients operated on by trainees have equivalent long-term clinical outcomes to patients operated on by consultant surgeons. For these patients, surgery can be safely performed by supervised trainees.
