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Marseille Chirurgical 1954
Topics: Congenital Abnormalities; Humans; Pylorus
PubMed: 13234830
DOI: No ID Found -
Gastroenterology Feb 1980In vitro force-length curves of rings from the gastroduodenal junction were obtained in standard tyrode solution, in tyrode with 140 mM KCl, and in calcium-free tyrode...
In vitro force-length curves of rings from the gastroduodenal junction were obtained in standard tyrode solution, in tyrode with 140 mM KCl, and in calcium-free tyrode with 5 mM sodium EDTA, to determine basal, total, and passive forces, respectively. Active force was obtained as a difference between total and passive forces. Basal, total, passive, and active forces were higher for pyloric rings than for duodenal and antral rings. Furthermore, in the pylorus the force-length curves were shifted to the left along the length axis due to a narrowing at the gastroduodenal junction. Pressure-diameter relationships calculated from the in vitro force-length data and compared with previously determined in vivo pressure-diameter data, demonstrated good correlation between the in vivo and in vitro data. These data indicate that the higher forces and pressures observed in the pylorus are due to a combination of higher active and passive components. At low levels of stretch, the active forces are higher, while at high levels of stretch the passive forces become prevalent. These data suggest that, because of its passive properties the pylorus may act as a stricture and resist opening to large diameters, thus impeding the passage of large boluses. Near closure, however, any pressure gradient at the gastroduodenal junction would be due to active contraction of the pyloric circular muscles, and thus be susceptible to modulation through neural and/or myogenic factors.
Topics: Animals; Biomechanical Phenomena; Cats; Female; Gastric Emptying; Male; Manometry; Muscle Contraction; Muscle Tonus; Pylorus
PubMed: 7350053
DOI: No ID Found -
Gastroenterology Feb 1983The mechanical activity of muscle strips from the gastroduodenal junction as obtained at operations was studied. Strips were cut so as to present the activity of the...
The mechanical activity of muscle strips from the gastroduodenal junction as obtained at operations was studied. Strips were cut so as to present the activity of the circular muscle layer of the antrum, the duodenum, the intermediate, or the distal pyloric sphincter. All strips increased and maintained a tension with increasing length, but distal sphincter strips did more so than the other types of strips. Phasic contractions were rare in distal sphincter strips, while all intermediate sphincter strips contracted at rates similar to antral strips. Electric field stimulation produced pure contractions in all responsive strips of the antrum and the intermediate sphincter. In most strips from the duodenum and distal sphincter the contraction response occurred during the stimulus, and the relaxation response far outlasted the stimulus. Distal sphincter strips had the larger relaxation responses, and duodenal strips had the larger contraction responses. Relaxation in response to electric stimulation, Ca++ withdrawal, or isoproterenol did not completely abolish the baseline tension of the distal sphincter. At least in its distal segment, muscle from the human pylorus differs from muscle of the antrum and the duodenum by its high baseline tension, its prominent neurogenic relaxation response, and its poor spontaneous contractile activity.
Topics: Biomechanical Phenomena; Calcium; Electric Stimulation; Gastrointestinal Motility; Humans; In Vitro Techniques; Isoproterenol; Muscle Contraction; Pylorus
PubMed: 6848408
DOI: No ID Found -
Digestive Diseases and Sciences Apr 1996The aim was to determine whether pyloroplasty decreases the strength of pyloric contractions and speeds gastric emptying of solids, while subsequent pyloric... (Comparative Study)
Comparative Study
The aim was to determine whether pyloroplasty decreases the strength of pyloric contractions and speeds gastric emptying of solids, while subsequent pyloric reconstruction restores these abnormalities to the control. In conscious dogs, pyloroplasty decreased the strength of pyloroduodenal pressure waves measured with a perfused sleeve sensor [mean +/- SEM pyloroduodenal motility index: control (N = 7) = 1116 +/- 351 mm Hg x sec/10 min; pyloroplasty (N = 7) = 43 +/- 19 mm Hg x sec/10 min; P < 0.05], and caused rapid gastric emptying of solids measured scintigraphically (mean +/- SEM half-emptying time: control = 246 +/- 14 min, pyloroplasty = 176 +/- 16 min; P < 0.05). The frequencies of pyloroduodenal waves and gastric emptying of liquids, however, were unchanged. Pyloric reconstruction restored the postpyloroplasty patterns to the control. In conclusion, pyloroplasty decreased the strength of pyloroduodenal contractions and sped gastric emptying of solids, while pyloric reconstruction restored the altered patterns to the control.
Topics: Animals; Consciousness; Dogs; Female; Food; Gastric Emptying; Gastrointestinal Motility; Indium Radioisotopes; Manometry; Pentetic Acid; Pressure; Pylorus; Technetium Tc 99m Sulfur Colloid
PubMed: 8674392
DOI: 10.1007/BF02213127 -
Digestive Diseases (Basel, Switzerland) 1991Outer diameter and thickness of the muscular wall of canine pylorus were measured simultaneously by determining the distance between pairs of implanted ultrasonic...
Outer diameter and thickness of the muscular wall of canine pylorus were measured simultaneously by determining the distance between pairs of implanted ultrasonic transducers, evaluating the sonic transit time with a digital sonometer. For the study of the motility in the gastroduodenal transit zone, the ultrasonically determined pyloric responses were compared with signals from conventional strain-gauge transducers sutured to the neighboring duodenum and gastric antrum. After stimulation of the gastrointestinal motility by an intravenous bolus injection of cholecystokinin octapeptide, pyloric contractions with a frequency of 5.2 min-1 could be recorded for some minutes; those contractions were independent of the more rapid antral and duodenal motility. Together with the observed tonic constriction of the pyloric ring, which could be inhibited by intravenous injection of adrenaline, an autonomous role of the gastroduodenal junction as a true sphincter is supported.
Topics: Animals; Dogs; Female; Gastric Emptying; Gastrointestinal Motility; Image Processing, Computer-Assisted; Male; Pylorus; Sincalide; Transducers; Ultrasonography
PubMed: 1804573
DOI: 10.1159/000171319 -
The British Journal of Surgery Aug 1990Post-mortem studies of the normal infantile pylorus have demonstrated an asymmetrical structure with the mucosa protruding under the circular muscle at the lesser curve...
Post-mortem studies of the normal infantile pylorus have demonstrated an asymmetrical structure with the mucosa protruding under the circular muscle at the lesser curve but not on the anterior surface. In addition the circular muscle was often discontinuous at the pyloroduodenal junction with only longitudinal fibres or even fibrous tissue separating the mucosa from the serosa. In a further specimen in which a pyloromyotomy had been performed 10 weeks previously, this asymmetry was more pronounced. This anatomy suggests that in pyloric stenosis it may be safer to site the caudal part of the pyloromyotomy incision on the anterior surface, rather than on the anterosuperior surface as most authors recommend. Perforation of the mucosa is predicted to be less likely.
Topics: Humans; Infant; Muscles; Pylorus; Sudden Infant Death
PubMed: 2393819
DOI: 10.1002/bjs.1800770826 -
American Journal of Surgery Jul 1970
Topics: Dilatation; Pylorus; Surgical Instruments
PubMed: 5426853
DOI: 10.1016/s0002-9610(70)80166-0 -
Surgical and Radiologic Anatomy : SRA 1994Cephalic pancreatoduodenectomy (CPD) with pylorus preservation has been suggested to improve the functional and nutritional result of surgery. At operation, the first...
Cephalic pancreatoduodenectomy (CPD) with pylorus preservation has been suggested to improve the functional and nutritional result of surgery. At operation, the first two centimeters of the duodenum are preserved, the vascular arch of the lesser gastric curvature is saved and the right gastroepiploic artery is resected at its origin. The aim of this study on 15 fresh cadavers was to determine the origin of the vascularization of the remaining duodenum and also the possibilities of preserving an optimal vascularization after CPD and pylorus preservation. All of the arteries supplying the remaining duodenum and arising either from the right gastric artery or the right gastroepiploic artery were identified. The distances between the origin of the infrapyloric artery and the termination of the gastroduodenal artery on the cranial and ventral pancreaticoduodenal artery and the left gastroepiploic artery were measured. At CPD with pylorus preservation, the study demonstrated that: 1) the cranial side of the remaining duodenum remains vascularized in 80% of the cases by one or two supraduodenal branches coming from the right gastric artery; 2) ligation of the right gastroepiploic artery eliminates all vascular supply to the caudal side of the remaining duodenum in almost half of the cases; 3) in these cases, the dissection of the bifurcation of the gastroduodenal artery and the vascular section beyond the origin of the infrapyloric artery allowed a direct vascular supply to the remaining duodenum to be preserved.
Topics: Arteries; Duodenum; Humans; Pancreaticoduodenectomy; Pylorus
PubMed: 7940080
DOI: 10.1007/BF01627590 -
Lille Medical : Journal de La Faculte... Jan 1979
Topics: Humans; Methods; Pylorus
PubMed: 431292
DOI: No ID Found -
The Australian and New Zealand Journal... May 1968
Topics: Barium Sulfate; Female; Gastroscopy; Humans; Male; Membranes; Middle Aged; Pylorus; Radiography; Stomach Diseases
PubMed: 5243168
DOI: No ID Found