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At least 325 records · Page 18Linked to original sources
PubMed2006

Improvement of delayed gastric emptying in pylorus-preserving pancreaticoduodenectomy: results of a prospective, randomized, controlled trial.

OBJECTIVE: To determine if an antecolic or a retrocolic duodenojejunostomy during pylorus-preserving pancreaticoduodenectomy (PpPD) was associated with the least incidence of delayed gastric emptying (DGE), in a prospective, randomized, controlled trial. SUMMARY BACKGROUND DATA: The pathogenesis of DGE after PpPD has been speculated to be related to factors such as inflammation, ischemia, gastric atony, motilin levels, and type of surgical procedure. Previous retrospective studies have shown a lower incidence of DGE after antecolic duodenojejunostomy. A prospective trial is needed. METHODS: Forty patients were enrolled in this trial between May 2002 and April 2004. Just before duodenojejunostomy during PpPD, the patients were randomly assigned to undergo either an antecolic or a retrocolic duodenojejunostomy. RESULTS: DGE occurred in 5% of patients with the antecolic route for duodenojejunostomy versus 50% with the retrocolic route (P = 0.0014). Those with the antecolic route had a significantly shorter duration of postoperative nasogastric tube drainage than did those with the retrocolic route (4.2 days versus 18.9 days, respectively, P = 0.047). By postoperative day 14, all patients with the antecolic route could take solid foods, while only 55% (11 of 20) of the patients with the retrocolic route could take solid foods (P = 0.0007). The length of stay in the hospital was 28 days for the antecolic group versus 48 days for the retrocolic group (P = 0.018). CONCLUSIONS: Antecolic reconstruction for duodenojejunostomy during PpPD decreases postoperative morbidity and length of hospital stay by decreasing DGE. Our data suggest that PpPD with antecolic duodenojejunostomy is a safer operation.

Aged↗
PubMed1989

The role of vagal adrenergic activity in the mechanism of gastric acid secretion after pylorus-ligation in the rat.

The role of the vagus nerve and adrenoceptor stimulation in acid secretion after pylorus-ligation in the rat has been examined. All drugs were administered intraperitoneally. Atropine (5 mg kg-1) depressed the H+ output (111 mumols +/- 33.8 vs 412.5 mumols +/- 62.2, mean +/- s.e.m., n = 10, P less than 0.001); cimetidine (40 mg kg-1) did not enhance this action, while vagotomy was more effective than atropine (32.7 mumols +/- 4.9, mean +/- s.e.m., n = 10, P less than 0.05). Atropine (10 mg kg-1) produced a similar depression to the 5 mg kg-1 dose. Cimetidine (100 mg kg-1) depressed the H+ output (248.5 mumols +/- 46.8, mean +/- s.e.m., n = 10, P less than 0.05). Propranolol (5-20 mg kg-1) had no significant effect on the H+ output but dose-dependent inhibition was produced by phenoxybenzamine or phentolamine; an inhibition similar to that achieved by vagotomy was seen with the 20 mg kg-1 dose. Both these drugs (5 or 10 mg kg-1) had no significant effect on the H+ output when given with atropine (5 mg kg-1) but the H+ output was significantly lower than that produced by either drug at the same dose given alone. Atropine (5 mg kg-1) with phenoxybenzamine or phentolamine (20 mg kg-1) produced H+ output not significantly different from that with vagotomy or either alpha-adrenoceptor given alone at 20 mg kg-1, but the result was significantly (P less than 0.05) lower than the H+ output with atropine (5 mg kg-1) alone.(ABSTRACT TRUNCATED AT 250 WORDS)

Adrenergic alpha-Antagonists↗
PubMed1978

Effect of sub-diaphragmatic vagotomy on gastric mucosal mast cell population in pylorus ligated rats.

Gastric mucosal mast cell population was studied following sub-diaphragmatic vagotomy in albino rats, 6 and 12 h after pylorus ligation. Sub-diaphragmatic vagotomy significantly increased the gastric mucosal mast cell population in both 6 and 12 h groups, the increase being more in the latter. The results suggest that the vagal impulses act on the gastric mucosal mast cells causing their degranulation. Following vagotomy the contents stay bound within the mast cells. Increase in mast cell population with the longer experimental situation was possibly due to the continuation of normal turnover of the mast cells in the gastric mucosa. The present study, however, does not lead to a conclusion that the vagal influence on mast cell population is similar throughout the gastro-intestinal tract.

Animals↗
PubMed2003

Ca2+ phase waves: a basis for cellular pacemaking and long-range synchronicity in the guinea-pig gastric pylorus.

Ca2+ imaging and multiple microelectrode recording procedures were used to investigate a slow wave-like electrical rhythmicity in single bundle strips from the circular muscle layer of the guinea-pig gastric pylorus. The 'slow waves' (SWs) consisted of a pacemaker and regenerative component, with both potentials composed of more elementary events variously termed spontaneous transient depolarizations (STDs) or unitary potentials. STDs and SW pacemaker and regenerative potentials exhibited associated local and distributed Ca2+ transients, respectively. Ca2+ transients were often larger in cellular regions that exhibited higher basal Ca2+ indicator-associated fluorescence, typical of regions likely to contain intramuscular interstitial cells of Cajal (ICCIM). The emergence of rhythmicity arose through entrainment of STDs resulting in pacemaker Ca2+ transients and potentials, events that exhibited considerable spatial synchronicity. Application of ACh to strips exhibiting weak rhythmicity caused marked enhancement of SW synchronicity. SWs and underlying Ca2+ increases exhibited very high 'apparent conduction velocities' ('CVs') orders of magnitude greater than for sequentially conducting Ca2+ waves. Central interruption of either intercellular connectivity or inositol 1,4,5-trisphosphate receptor (IP3R)-mediated store Ca2+ release in strips caused SWs at the two ends to run independently of each other, consistent with a coupled oscillator-based mechanism. Central inhibition of stores required much wider regions of blockade than inhibition of connectivity indicating that stores were voltage-coupled. Simulations, made using a conventional store array model but now including depolarization coupled to IP3R-mediated Ca2+ release, predicted the experimental findings. The linkage between membrane voltage and Ca2+ release provides a means for stores to interact as strongly coupled oscillators, resulting in the emergence of Ca2+ phase waves and associated pacemaker potentials. This distributed pacemaker triggers regenerative Ca2+ release and resultant SWs.

Acetylcholine↗
PubMed1988

What happens to the pylorus after pyloromyotomy?

The rate of return to normal of the pylorus muscle in infantile hypertrophic pyloric stenosis was measured by ultrasound, using a simple pyloric volume calculation and a pyloric muscle index. The muscle hypertrophy took from two to 12 weeks to resolve.

Follow-Up Studies↗
PubMed1978

Cholecystokinin inhibits gastric emptying by acting on both proximal stomach and pylorus.

Cholecystokinin is a potent inhibitor of gastric emptying. It is known to both relax the proximal stomach and contract the pyloric sphincter, and either one or both of these actions could mediate inhibition of gastric emptying. We investigated the relative importance of these two actions by studying the effectiveness of the C-terminal octapeptide of cholecystokinin (OP-CCK) to inhibit the emptying of a liquid meal (300 ml saline) before and after operations that either remove or destroy the pyloric mechanism (antrectomy and pyloroplasty), or lead to loss of accommodation of the proximal stomach (vagotomy), and after both vagotomy and antrectomy, and vagotomy and pyloroplasty. The results show that OP-CCK causes dose-related inhibition of gastric emptying in the intact dog. After either pyloroplasty or antrectomy the effectiveness of low but not of high doses of OP-CCK is lost. After vagotomy, OP-CCK at any dose was ineffective. The findings suggest that cholecystokinin inhibits gastric emptying by acting both on the pylorus and on the proximal stomach.

Animals↗
PubMed1982

Hormonal effects on the pylorus.

The control mechanisms of pyloric pressure responses have not been elucidated clearly. The purposes of this study were twofold: 1) to determine the dose-related pressure responses of the pylorus to exogenous glucagon, secretin, and cholecystokinin, and 2) to correlate changes in pyloric pressure with serum concentrations of these hormones. Pyloric pressures were measured by infusion manometry, and the serum concentrations of glucagon and secretin were quantitated using radioimmunoassays. Each of the hormones tested, glucagon, secretin, and cholecystokinin, increased the pyloric pressure significantly. The lowest active dosages tested for each of these peptide hormones were 2 micrograms.kg-1.h-1, 2 U.kg-1.h-1, and 1 U.kg-1.h-1, respectively. The maximal pyloric pressure responses recorded were 8.7 +/- 1.1 (P less than 0.05), 12.6 +/- 2.1 (P less than 0.02), and 14.8 +/- 1.7 (P less than 0.02) mmHg, respectively. The pyloric pressure responses to insulin hypoglycemia, duodenal acidification, and intraduodenal olive oil were 11.3 +/- 1.5, 13.4 +/- 1.4, and 11.3 +/- 1.4 mmHg, respectively. The serum concentrations of immunoreactive glucagon during infusion of the lowest active dosage of glucagon and insulin hypoglycemia were 801 +/- 55 and 322 +/- 12 pg/ml, respectively. The serum concentrations of immunoreactive secretin during infusion of the lowest active dosage of secretin and during duodenal acidification were 980 +/- 60 and 110 +/- 7.0 pg/ml, respectively. Although pyloric contraction can be induced by administration of exogenous glucagon, secretin, and cholecystokinin, these studies suggest that these effects may have no physiological relevance.

Cholecystokinin↗
PubMed1983

Mechanism of action of cholecystokinin octapeptide on rat antrum, pylorus, and duodenum.

The mechanism of action of cholecystokinin octapeptide (CCK-OP) on tonic and phasic contraction of antral, pyloric, and duodenal smooth muscles was studied with a novel perfusion manometric system in isolated esophagogastroduodenal preparations of the rat. CCK-OP increased baseline pressure at each site, frequencies of phasic contractions in the antrum and pylorus, and amplitudes in the duodenum. It decreased antral and pyloric amplitudes and frequency of duodenal phasic contractions. CCK-OP action on tonic contraction was tetradotoxin (TTX) susceptible and its action on phasic contractions was TTX resistant. Phentolamine, phenoxybenzamine, propranolol, catecholamine depletion of preparations by reserpine-tetrabenazine, and the block of catecholamine synthesis at different levels significantly inhibited CCK-OP-induced tonic contraction, whereas atropine had no influence. Adrenergic and cholinergic neural actions on phasic contractions altered the level of amplitudes and frequencies on which CCK-OP action occurred. It is concluded that CCK-OP action on tonic contraction of the rat gastroduodenal junction is mediated by a neural noncholinergic pathway, whereas its effect on muscles responsible for phasic contractions is a direct one.

Animals↗
PubMed2001

Pylorus-preserving pancreatoduodenectomy: influence of a Billroth I versus a Billroth II type of reconstruction on gastric emptying.

BACKGROUND/AIM: Delayed gastric emptying (DGE) is a frequent problem after pylorus-preserving pancreatoduodenectomy. Important risk factors are the presence of intra-abdominal complications. Searching for other causes, this study evaluates the influence of the type of reconstruction after a pancreatoduodenectomy (Billroth I vs. Billroth II; B I vs. B II on DGE. METHODS: A retrospective study was performed evaluating consecutive patients from two surgical institutes. 174 patients were included (B II type of reconstruction n = 123, period 1992-1996; B I type of reconstruction n = 51, period 1988-1998). DGE was defined by gastric stasis requiring nasogastric intubation for 10 days or more or the inability to tolerate a regular diet on or before the 14th postoperative day. RESULTS: After a B I type of reconstruction, there was significantly longer nasogastric intubation period as compared with a B II type of reconstruction (B I median 13 days, range 4-47, B II median 6 days, range 1-40; p < 0.05). There was no difference in postoperative commencement of a normal diet. Also significantly more patients had DGE after a B I (76%) as compared with a B II type of reconstruction (32%; p < 0.05). CONCLUSIONS: The results of this study indicate a significantly higher incidence of DGE after a B I type of reconstruction as compared with a B II type reconstruction. The etiology remains speculative.

Adult↗
PubMed1999

Treatment strategy for pancreatic head cancer: pylorus-preserving pancreatoduodenectomy, intraoperative radiotherapy and portal catheterization.

Pancreatic cancer is the disease of gastrointestinal cancer with the poorest prognosis. At present, in addition to surgery, multimodality treatment combining a variety of therapeutic methods is used. We usually employ the following combination of surgery, radiotherapy and chemotherapy: D2 surgery with pylorus-preserving pancreatoduodenectomy (PPPD), intraoperative radiotherapy (IORT), and portal catheterization (PC) with fluorouracil as the chemotherapy. In this study, we made a historical comparison of PPPD and PD and obtained the following findings: (1) PPPD allows almost the same extent of D2 dissection as conventional PD, and achieves radical treatment without any problems; (2) suppression of local recurrence by IORT cannot be expected from the results of the comparison between the four approaches, i.e. surgery alone, surgery + IORT, surgery + PC and surgery + IORT + PC, and (3) the rate of liver metastasis in patients treated by PC was significantly low.

Catheterization↗
PubMed1987

Effects of morphine on gastric ulceration, barrier mucus and acid secretion in pylorus-ligated rats.

The effects of intraperitoneal (IP) or intracerebroventricular (ICV) administration of morphine on acid and pepsin secretion, gastric ulceration and gastric bound mucoproteins were investigated in pylorus-ligated rats. Morphine, administered IP, produced a dose-dependent inhibition of the gastric secretion volume, acidity, pepsin output and bound mucoproteins. By contrast, the effect of morphine on gastric ulcers was not dose-dependent: a significant increase in gastric lesions was obtained with morphine 5 mg/kg IP. Naloxone IP prevented the effects of morphine on gastric secretory volume, acidity and pepsin output, but not on gastric mucus and ulcer score. ICV administration of morphine induced a dose-dependent inhibition of secretory volume, acidity and ulcer score, whereas no modification of gastric mucus was observed. Naloxone ICV prevented the effects of ICV morphine. Overall results suggest that morphine inhibits gastric secretion through both central and peripheral opioid receptors, whereas the inhibitory effect of morphine on bound mucus appears to be exerted on mucus synthesis through peripheral opioid receptors. This inhibitory effect on barrier mucus accounts at least in part for the gastric ulcerogenic action of morphine.

Animals↗
PubMed1991

Diameter and wall thickness recording of canine pylorus with implantable miniature ultrasonic transducers.

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.

Animals↗
PubMed2005

Effect of humulus lupulus on gastric secretion in a rat pylorus-ligated model.

In this study, we investigated the pharmacological effect of humulus lupulus (hops) on gastric juice volume and acidity using a rat pylorus-ligated model. In an intraorally administered experiment, hops clearly increased gastric juice volume without affecting acidity. On the other hand, hops had no influence on gastric juice volume when it was intragastrically administered. A cholinergic agonist, carbachol, increased gastric juice volume without affecting acidity, whereas histamine increased gastric juice volume and acidity. The increase of gastric juice volume induced by carbachol was completely inhibited by atropine. On the other hand, atropine did not inhibit the increase in gastric juice volume induced by histamine. The increase in gastric juice volume induced by hops was completely inhibited by atropine. These results suggested that the increase in gastric juice volume induced by intraorally administered hops could be mediated by the cholinergic nervous system.

Animals↗
PubMed1976

Effects of L-glutamine of acetylsalicylic acid or taurocholic acid-induced gastric lesions and secretory changes in pylorus-ligated rats under normal or stress conditions.

An oral dosing of either acetylsalicylic acid (ASA) or taurocholic acid (TCA) to pylorus-ligated rats subjected to water-immersion stress produced severe damage to the gastric musoca in contrast to the irritation observed in non-stressed ones. The irritative activity of ASA or TCA on gastric mucosa under stress was dose-dependent. Stress itself (23 degrees C, 7 hr) did not induce any appreciable changes in gastric mucosa under stress wasic mucosa of rats. L-glutamine, given together with SAS or TCA, significantly prevented the potentiated development of SAS- or TCA-induced gastric lesions in stressed rats. L-glutamine also prevented in varying degrees the reduction of acid and increment of Na+ ion in gastric juice accumulated in stressed rats in response to ASA or TCA.

Animals↗
PubMed1991

[Interdigestive contractile characteristics of canine pylorus and gastroduodenal regions].

Interdigestive contractile activity of the gastric body, antrum, pyloric ring and duodenum was recorded by means of chronically implanted force transducers in 5 conscious dogs. In accordance with interdigestive phase III contractions in the gastroduodenal region, a burst of strong contractions and remarkable relaxations were observed to occur in the pyloric ring. In accordance with the intense phase III contractions in the antrum, the pyloric ring was relaxed and duodenal contractions declined and ceased as if the passage of gastric contents expelled by the strong contractions in the antrum were being done smoothly. With the termination of the antral contractions, it was observed that the duodenal contractions were initiated and followed immediately by tonal increase in the pyloric ring super-imposed with phasic contractions. These coordinated contractions between the pyloric ring and the duodenum appear to prevent reflux of duodenal contents to the stomach. Bilateral vagal cooling blockade abolished this coordination. As the gastric contractions ceased completely during vagal cooling blockade, irregular phasic contractions were initiated and no relaxation was observed on the pylorus. In conclusion, the pyloric ring is a true functional sphincter which regulates gastric emptying and prevents reflux from the duodenum in the interdigestive state, and these coordinated contractions are regulated by the vagal nerves.

Animals↗
PubMed1998

Motility of the canine pyloric ring following a pylorus-preserving pancreatoduodenectomy.

Recently, function-preserving operations have become popular, and pylorus-preserving pancreatoduodenectomy (PPPD) is frequently performed for diseases of the head of the pancreas. However, there are only a few basic studies on the pyloric function after PPPD. Using strain gauge force transducers (SGTs), we studied the pyloric motility of normal and PPPD dogs. We prepared three normal and three PPPD dogs in which the SGTs were implanted onto the antrum and pyloric ring, etc. In conscious dogs, the spontaneous gastrointestinal motility was recorded, and the plasma motilin concentration was measured during the interdigestive state. Following the administration of exogenous Leu13-motilin, the motility was again recorded. The relaxation and opening of the pyloric ring was observed synchronously with intense contractions of the antrum during the phase III of normal dogs. Phase III-like motility was recorded in the PPPD dogs, which was not a typical periodic motility. The plasma motilin concentration of one PPPD dog could be measured, and the motilin levels during the phase III-like motility were higher than during phase I. The phase III-like motility was induced by Leu13-motilin in both normal and PPPD dogs. The phase III-like motility recorded in the PPPD dogs was not a typical periodic one, and this aberrant motility was considered to be one of the causes of delayed gastric emptying. Phase III-like motility was induced by the administration of Leu13-motilin; therefore, it is possible that Leu13-motilin improved the motility of the pyloric ring after PPPD.

Animals↗
PubMed1992

Long-term results of pylorus-preserving gastrectomy for gastric ulcer.

The postoperative results of pylorus-preserving gastrectomy (PPG) for gastric ulcer performed in 134 patients during the past 25 years (mean postoperative period, 16.6 years) were studied. The incidence of postoperative complications was low. Dumping syndrome occurred in only 4.4% and 0% of cases as assessed by questionnaire and interview, respectively. Four (5.4%) of 74 patients available for this study had ulcer recurrence. In one of these four patients concurrent gastroduodenal ulcer was suspected from preoperative gastric analysis. The site of recurrence was found in all cases to be the remnant antral gland area along the greater curvature between the proper gastric gland area and the duodenum. Basal and maximal acid outputs at the time of relapse were significantly higher in patients with recurrence than in patients without recurrence. The fasting and postprandial serum gastrin levels were high in one patient with recurrence, whose antrum was preserved as long as 3 cm proximal to the pyloric ring; this was longer than that described in our original method of PPG. In two other recurrent cases the serum gastrin levels were not different from those in nonrecurrent cases. Immunohistochemical examination of the residual antrum showed no increase in the G-cell density in patients either with or without recurrence. These results suggest that the long-term quality of life of patients treated with PPG remains favorable. Recurrence rate can be further reduced if PPG is strictly indicated for gastric ulcer only and carried out by meticulous surgical techniques. In the pathogenesis of the ulcer recurrence the role of gastrin release from the residual antral mucosa seems to be limited.

Adult↗