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At least 19 recordsLinked to original sources
PubMed2002

Functional characteristics of the pylorus in patients undergoing pylorus--preserving gastrectomy for early gastric cancer.

BACKGROUND: This study investigates the functional characteristics of the pylorus in patients undergoing pylorus-preserving gastrectomy (PPG) for early gastric cancer. METHODS: In study 1, postprandial symptoms and gastric emptying were compared between 2 groups of 12 patients with early gastric cancer more than 1 year after either PPG (PPG group) or distal gastrectomy (DG) (DG group). Gastric emptying was evaluated with the dual isotope technique for liquids and solids separately. In study 2, pyloric motility was evaluated with a sleeve/sidehole manometric assembly in 7 patients undergoing PPG, which was compared with that in the preoperative patients. RESULTS: In study 1, the overall modified Visick score of postprandial symptoms and the Sigstad dumping score were significantly lower in the PPG group compared with the DG group (P <.05). Early accelerated gastric emptying was observed in both groups for liquids, but only in the DG group for solids. In study 2, isolated pyloric pressure waves induced by intraduodenal lipid infusion and phase III-like activity induced by intravenous erythromycin infusion were preserved after PPG. CONCLUSIONS: The quantitative analysis of postoperative symptoms revealed that PPG patients were associated with better clinical conditions than DG patients. The clinical benefits of PPG are considered to be based on the function of the preserved pylorus.

Adult↗
PubMed2000

Effect of denervation of the pylorus and transection of the duodenum on acetaminophen absorption in rats; possible mechanism for early delayed gastric emptying after pylorus preserving pancreatoduodenectomy.

Early delayed gastric emptying has been reported as a frequent complication following pylorus preserving pancreatoduodenectomy (PPPD). We investigated the effect of division of the pyloric branch of the vagus nerve and/or transection of the duodenum on gastric emptying using the acetaminophen method in rats to speculate the unknown etiology of early delayed gastric emptying after PPPD. Twenty-four male Wistar rats were divided into the following four groups; Group S, sham operation as controls; Group N, disturbance of neuro-vascular supply to the pylorus; Group D, temporary interference of the duodenal continuity; and Group N+D, with both procedures in Group N and Group D. Gastric emptying was measured using the acetaminophen method at 1, 2, and 4 weeks after operations in each group. No significant difference was observed in Group S at any intervals after the operation. Gastric emptying was prolonged significantly in Group N, Group D and Group N+D compared to Group S until 2 weeks following surgery. Significant delayed gastric emptying was sustained in Group N+D at 4 weeks, although gastric emptying in Group N and Group D was improved by 4 weeks. The results in rodent models suggest that both dissection of the pyloric branch of the vagus and transection of the duodenum might be causative factors of postoperative delayed gastric emptying following PPPD.

Acetaminophen↗
PubMedDate not supplied

[A comparative evaluation of the efficacy of pylorus-destroying and pylorus-preserving operations with vagotomy in bleeding duodenal ulcers].

Results are analyzed of surgical treatment of 230 patients with duodenal ulcer complicated by bleeding, who underwent vagotomy and pylorus-nonsparing and pylorus-sparing operations. Of these, 110 patients were subjected to vagotomy involving pyloroplasty, 120 to selective proximal vagotomy with duodenoplasty. Results of postoperative 3- to 5-yr survival are analyzed. A method is suggested for treatment of postvagotomy syndromes.

Adult↗
PubMed2006

Surgical anatomy of the innervation of pylorus in human and Suncus murinus, in relation to surgical technique for pylorus-preserving pancreaticoduodenectomy.

AIM: To clarify the innervation of the antro-pyloric region in humans from a clinico-anatomical perspective. METHODS: The stomach, duodenum and surrounding structures were dissected in 10 cadavers, and immersed in a 10mg/L solution of alizarin red S in ethanol to stain the peripheral nerves. The distribution details were studied to confirm innervations in the above areas using a binocular microscope. Similarly, innervations in 10 Suncus murinus were examined using the method of whole-mount immunohistochemistry. RESULTS: The innervation of the pyloric region in humans involved three routes: One arose from the anterior hepatic plexus via the route of the suprapyloric/supraduodenal branch of the right gastric artery; the second arose from the anterior and posterior gastric divisions, and the third originated from the posterior-lower region of the pyloric region, which passed via the infrapyloric artery or retroduodenal branches and was related to the gastroduodenal artery and right gastroepiploic artery. For Suncus murinus, results similar to those in humans were observed. CONCLUSION: There are three routes of innervation of the pyloric region in humans, wherein the route of the right gastric artery is most important for preserving pyloric region innervation. Function will be preserved by more than 80% by preserving the artery in pylorus-preserving pancreaticoduodenectomy (PPPD). However, the route of the infrapyloric artery should not be disregarded. This route is related to several arteries (the right gastroepiploic and gastroduodenal arteries), and the preserving of these arteries is advantageous for preserving pyloric innervation in PPPD. Concurrently, the nerves of Latarjet also play an important role in maintaining innervation of the antro-pyloric region in PPPD. This is why pyloric function is not damaged in some patients when the right gastric artery is dissected or damaged in PPPD.

Aged↗
PubMed1997

[Substantiation and choice of pylorus preserving and pylorus destructive surgery with vagotomy in ulcer of the pyloroduodenal zone with hemorrhage].

The results of examination and surgical treatment of 230 patients with duodenal ulcer, complicated by haemorrhage, were analyzed. Vagotomy with pyloroplasty was conducted in 110 patients, vagotomy with duodenoplasty--in 120. The algorithm of operations conduction was elaborated, the results of treatment of patients in terms up to 5 years were estimated.

Adult↗
PubMed2004

[Immediate and remote results of pylorus-preserving and pylorus-reducing operations in complex surgical treatment of perforated pyloric-duodenal ulcers].

The results of surgical treatment of 224 patients with perforated pyloroduodenal ulcers were analyzed. 110 patients were operated using pyloruspreserving and pylorusreducing methods. The new method of pyloroduodenoplasty is suggested. Duodenogastral reflux after pyloruspreserving operations is arised in 4.5% of observations, after pylorusdestructive--in 46.7%.

Duodenal Ulcer↗
PubMedDate not supplied

The importance of the pylorus as a regulator of solid and liquid emptying from the stomach.

The role of the pylorus in the control of gastric emptying of liquids and digestible solids was investigated in the present study by pylorus excision in six pigs. The pylorus was left intact in another six pigs. Antro-pyloro-duodenal motility was recorded by a sleeve sensor and side holes. Liquid emptying was significantly more rapid in pylorus excised than in pylorus intact animals, during intraduodenal infusion of isosmolar dextrose (712 mL vs 107 mL), fatty acid (402 mL vs 46 mL), amino acids (752 mL vs 112 mL), 25% dextrose (392 mL vs 51 mL) and 3 normal saline (705 mL vs 157 mL). In pylorus excised animals, in contrast to pylorus intact animals, the manometric pattern of isolated pyloric pressure waves at the distal stomach was rarely seen (P < 0.05). In a second series of experiments, pylorus excised animals emptied significantly more (P < 0.04) meat over 120 min (181 g) than pylorus intact animals (80 g), but the proportion of particle sizes emptied was unaltered. In the pig, localized pyloric contractions are important for retardation of gastric emptying when nutrient or hyperosmolar solutions enter the duodenum. By contrast, the pylorus is unimportant in determining the size of solid particles emptied from the stomach.

Animals↗
PubMed1976

[Electromyographic studies on gastric and intestinal motor function following pylorus preserving gastrectomy with jejunal interposition in dogs (author's transl)].

The gastric and intestinal motor function following pylorus preserving gastrectomy with jejunal interposition were studied electromyographically in dogs. The action potentials were recorded from the interposed jejunal segment, the preserving pylorus and the duodenum before and after insertion of warm water. Studies were made on the frequency, the propagation velocity of the spike-bursts in the portions mentioned above, and the incidence of the spike-bursts which propagated from the distal porition of the interposed jejunal segment to the preserving pylorus, and from the preserving pylorus to the proximal portion of the duodenum. The results obtained are as follows: 1) The frequency of the spike-bursts found in the interposed jejunal segment, the preserving pylorus, and the duodenum showed a remarkable increase after insertion of warm water. 2) The propagation velocity of the spike-bursts in the interposed jejunal segment, the preserving pylorus, and the duodenum were accelerated after insertion of warm water. 3) There were observed a moderate increase in the incidence of the spike-bursts which propagated from the distal portion of the interposed jejunal segment to the preserving pylorus, and from the preserving pylorus to the proximal portion of the duodenum after insertion of warm water. These findings suggested that the motor function of the interposed jejunal segment, that of the preserving pylorus, and that of the duodenum after pylorus preserving gastrectomy with jejunal interposition might be kept not yet injured enough to transport the contents from the interposed jejunal segment into the duodenum.

Action Potentials↗
PubMed1980

Mechanisms of gastric acid secretion after pylorus and oesophagus ligation in the rat.

1. The effect of vagotomy on gastric acid secretion was studied in chronic gastric fistula rats at various times after denervation. In these rats basal and pentagastrin-induced acid output was permanently reduced. Thus, the magnitude of the acid response to pentagastrin in the conscious fistula rat is dependent upon an intact vagus. 2. The acid response to pylorus ligation in vagally intact rats was unaffected by drainage of the stomach and therefore not caused by distension. Bilateral vagotomy, performed simultaneously with the ligation, completely abolished acid secretion, while unilateral vagotomy reduced the acid output by half. Hence, in innervated rats, an intact vagal impulse flow appears to be essential for the acid response to pylorus ligation. When the pylorus ligation was performed 2-8 weeks after truncal vagotomy, the acid output showed a progressive return towards pre-denervation values. In the denervated rats the acid response to pylorus ligation was blocked by drainage of the stomach and therefore probably caused by distension, a mechanism which is independent of the vagal impulse flow. 3. The response to pylorus ligation in innervated rats was blocked by atropine and chlorisondamine but not by metiamide. In the denervated rats, the response to pylorus ligation was blocked by all three drugs. 4. Following ligation of both the pylorus and the oesophagus the acid response was poor. With drainage of the oesophagus the acid response was much enhanced, suggesting that oesophageal distension inhibits acid secretion. In the vagotomized rat the poor acid response to oesophageal + pyloric ligation could not be overcome by drainage of the oesophagus. In the innervated rat gastric distension could overcome the inhibition induced by oesophageal ligation. Also in chronically, but not in acutely vagotomized rats, gastric distension brought about a good acid response. Conceivably, gastric reflex mechanisms can activate acid secretion through vagal and/or intramural pathways. Both in innervated and denervated rats the response to gastric distension was inhibited by atropine, chlorisondamine and metiamide. 5. The results suggest that in the innervated rat vago-vagal reflexes are important for the gastric hypersecretion following ligation of the pylorus, and for the acid response to gastric distension following ligation of the pylorus and oesophagus. In the chronically vagotomized rat local intramural reflexes elicited by gastric distension are responsible for the acid response.

Animals↗
PubMed1982

Gastric acid response to pylorus ligation in rats: is gastrin or histamine involved?

1. Pylorus ligation stimulated the acid output in vagally intact rats. The serum gastrin concentration and the gastric mucosal histamine content were not affected. The gastric histidine decarboxylase activity was initially slightly elevated and then greatly reduced (12-20 hr after ligation).2. Pylorus ligation stimulated the acid output in chronically, but not in acutely, vagotomized rats. Chronic vagotomy raises the serum gastrin concentration, the gastric histamine content and histidine decarboxylase activity. The serum gastrin concentration was further raised by pylorus ligation. The histamine content was initially lowered but returned to preligation values after 20 hr. The histidine decarboxylase activity first decreased, but increased to very high levels 5-6 hr after ligation. Twelve hours after ligation it was lower than before ligation.3. Following pylorus ligation pentagastrin and histamine stimulated the acid output in vagally intact and in acutely vagotomized but not in chronically vagotomized rats. By contrast, pentagastrin raised the histidine decarboxylase activity in vagally intact and in chronically vagotomized, but not in acutely vagotomized rats.4. The two major populations of endocrine cells of the oxyntic gland area (ECL cells and A-like cells) are argyrophil, store histamine and are capable of taking up exogenous DOPA and of decarboxylating it to dopamine which is retained in the cytoplasm for several hours. As evidenced by light and fluorescence microscopy pylorus ligation did not affect their argyrophilia or their ability to produce and store dopamine.5. Pylorus ligation caused ultrastructural changes in the gastrin cells of the pyloric gland area and in the histamine-storing ECL and A-like cells of the oxyntic gland area. The two endocrine cell types in the oxyntic gland area were enlarged by pylorus ligation, more so after 16 hr than after 4 hr. The size of the gastrin cells seemed unaffected. In all three cell types pylorus ligation reduced the number of cytoplasmic granules. There was no increase in the Golgi area or in the endoplasmic reticulum in any of the endocrine cell types of the oxyntic gland area. It appears unlikely that the ultrastructural changes of the ECL and A-like cells reflect an increased rate of histamine mobilization.6. The acid response to pylorus ligation probably reflects neuronal reflex mechanisms exclusively. There is no evidence that gastrin or histamine released from gastric endocrine cells mediate the response.

Animals↗
PubMed1999

An explanation of gastric hypersecretion in the pylorus-ligated rat.

The hypersecretion of gastric acid in the pylorus-ligated rat has been shown to be of vagal origin. The present series of experiments were performed to identify the stimulus. The pyloric sphincter was ligated in a series of Sprague Dawley rats. Along with pylorus ligation, various other surgical manipulations were performed. Intestinal obstruction by ligation approximately 20 cm aboral to the cecum reduced unstimulated gastric secretion in the pylorus-ligated rat. However, perfusion of the lower small intestine with bicarbonate (143 mEq/L) stimulated secretion. Perfusion with either saline or deoxycholic acid (20 mEq/L) did not alter secretion. This supports a role for bicarbonate in the hypersecretion of gastric acid in the pylorus-ligated rat. The reflex appears to involve the myenteric plexus, since section of the pylorus seemed to attenuate gastric secretion. Plasma from animals with pylorus ligation, either alone or with intestinal ligation, equally inhibited gastric secretion. This suggests that while some factor inhibiting gastric secretion may be present, it appears to be unrelated to pylorus ligation.

Animals↗
PubMed2005

The pylorus.

The pylorus controls the flow between a reservoir dedicated to mechanical and chemical digestion (the stomach) and a conduit dedicated to the absorption of nutrients (the intestines). The pylorus adjusts gastric outflow resistance to physiological needs. It allows the outflow of isotonic fluids yet selectively retains particles too large for delivery to the intestines and in concert with the antrum further processes them (gastric sieving). Unlike most gut sphincters, the pylorus, at least of man, maintains a patent lumen most of the time. It only intermittently becomes a tightly closed barrier that arrests all flow out of and into the stomach. The geometry of the pylorus changes dramatically from the relaxed open state to closure. Pyloric closure involves contraction of its proximal and distal muscle loops, and occlusion of its lumen by mucosal folds. Current studies that combine pressure recordings with imaging by magnetic resonance imaging or ultrasound and fluid-mechanical analysis shed new light on the role of the pylorus in gastric emptying and digestion. Much has been learned in recent years on the innervation of the normal pylorus particularly from studies on infantile hypertrophic stenosis, and attempts are being made to treat gastroparesis by interventions on the pylorus.

Humans↗