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At least 55 records · Page 3Linked to original sources
PubMed1983

Measurement of cholecystokinin octapeptide-induced motility of rat antrum, pylorus, and duodenum in vitro.

Motor effects of cholecystokinin octapeptide (CCK-OP) on rat antrum, pylorus, and duodenum have been studied in vitro under standard conditions. Intraluminal pressure changes were simultaneously measured at the three locations using a perfusion manometric system with a novel intraluminal pressure-sensor device. This device comprised an acrylic cast of the rat gastroduodenal tract containing the perfusion catheters that reached the surface of the cast with their outlets in the antrum, pylorus, and duodenum. A selective and sensitive intraluminal local pressure measurement was achieved with this pressure sensor due to its shape. CCK-OP increased base-line pressure in the antrum, pylorus, and duodenum; frequencies of phasic contractions in the antrum and pylorus; and amplitudes in the duodenum. The peptide also decreased contraction amplitudes in the antrum and pylorus and frequency of phasic contractions in the duodenum. It is concluded that the novel intraluminal pressure sensor is a useful tool for measuring local pressure changes in the gastroduodenal tract of the rat. In this experimental model, effects of CCK-OP on antral, pyloric, and duodenal base-line pressure are comparable with those observed in isolated muscle strips and in the intact organ of humans, dogs, and opossums. A different behavior, however, was observed in the force of antral and frequency of duodenal phasic contractions.

Animals↗
PubMed1988

Inhibitory opioid receptors in canine pylorus.

In 18 anesthetized dogs, antroduodenal and pyloric motility was monitored in vivo by a sleeve and perfused side-hole manometric assembly and by antral and duodenal serosal strain gauges. Close intra-arterial injection to the pylorus of dynorphin-(1-13) (Dyn) for kappa-receptors, [D-Pen2,5]enkephalin (DPen2,5-Enk) for delta-receptors, and [N-Me-Phe3-D-Pro4]morphiceptin (PL017) and [D-Ala2,N-Me-Phe4,Gly5-ol]enkephalin (DAGO) for mu-receptors showed no excitatory effect in the pylorus. When pyloric motor activity was increased by duodenal field stimulation 3-5 cm aboaad from the pylorus, Dyn greater than DPen2,5-Enk greater than DAGO produced a dose-dependent inhibition of the pyloric motor activity. Naloxone (200 micrograms/kg iv and 20 micrograms ia) had no effect on the pyloric excitation due to duodenal field stimulation, but it reduced the inhibitory response of intra-arterially injected opioids. In addition, opioid binding ([3H]diprenorphine) in microsomal and mitochondrial fractions from the inner circular muscle ring of the pylorus showed a distribution similar to the neuronal marker [3H]saxitoxin but no correlation to the plasma membrane marker 5'-nucleotidase. These results suggest the existence of inhibitory opioid receptors (kappa- and delta-receptors) on excitatory neurons in the intestinal neuronal pathway, which activates the canine pylorus.

Animals↗
PubMed2001

Pylorus-preserving total pancreatectomy. Early and late results.

BACKGROUND/AIMS: Preservation of the pylorus is an accepted alternative procedure to the classical Whipple operation for pancreatic head resection but data describing its value for total pancreatectomy are sparse. METHODS: A prospective analysis of 22 total pancreatectomies performed in a consecutive series of 436 pancreatic resections from 1.11.93 to 1.5.99. RESULTS: 11 patients underwent total pancreatectomy with preservation of the pylorus. Histopathological examination revealed pancreatic adenocarcinoma in 16 cases and duodenal adenocarcinoma in 1 patient, 5 patients had other types of pancreatic neoplasm. In-hospital mortality was 4.5% (n = 1), cumulative morbidity was 59% and reoperations were performed in 9.1% of cases (n = 2). Median follow-up was 37 months (range 5-66). 62% of patients (n = 13) developed tumor recurrence and 13 patients died during the follow-up period with 10 deaths being cancer related. There was no difference concerning postoperative and follow-up morbidity of survival between patients undergoing pylorus-preserving total pancreatectomy or pancreatectomy with gastrectomy. However, postoperative body weight was increased 3, 6, 9 and 12 months following preservation of the pylorus. CONCLUSION: Total pancreatectomy with preservation of the pylorus is a feasible type of resection for all types of pancreatic or ampullary tumors, which shows a similar morbidity and long-term survival but improved nutritional recovery compared with standard total pancreatectomy.

Adenocarcinoma↗
PubMed1994

[Experimental studies on the gastroduodenojejunal motility and gastric emptying after duodenectomy with preservation of the total stomach and pylorus].

It is of interest to know whether or not the removal of the pyloric branch of the vagus nerve (subsequently referred to as vagotomy) is associated with the early stagnation of gastric contents supervening upon duodenectomy with preservation of the total stomach and pylorus (innervation of pylorus group 5, denervation of pylorus group 5). In the present study preservative duodenectomy was performed on dogs to determine the effects of vagotomy on gastroduodenojejunal motility and gastric emptying. The group of typical strong preprandial contraction waves (subsequently referred to as phase III) did not appear after vagotomy. The appearance of phase III was delayed and its duration was reduced. The duration of pyloric phase III significantly reduced, at 2 and 4 weeks post-surgery, in the denervation of pylorus group, compared to the innervation of pylorus group, and at 4 weeks, the area of phase III was significantly decreased in the denervation group. Post-vagotomy gastric emptying was poor throughout the course of observation. The results of this study suggest that the vagotomy-induced change in gastroduodenal motility in fasting conditions is one of the factors responsible for the stagnation of gastric contents.

Animals↗
PubMed1987

The manometric findings at the human pylorus. The evidence against the presence of a tonic sphincter.

The results of pyloric manometric studies conflict, some showing evidence of a sphincter at the pylorus, others not: hence the term 'the fickle pylorus'. In this study we used perfused catheters to investigate the manometric properties of the human pylorus, in an attempt to explain the different results of similar experiments. A high-pressure zone (HPZ) of 5.9 mmHg (mean) was found at the pylorus in 53% of 170 measurements. The subjects' position had no effect on the HPZ, nor had duodenal acidification. Eating a meal increased the pressure from 5.0 mg Hg in the fasting state to 8.0 mm Hg after a meal. The results and those of 11 other manometric studies are considered; the evidence is against the presence of a tonic sphincter at the pylorus.

Adult↗
PubMed1990

Identification of the pylorus from the intraluminal pH profile. Validation of the method by comparing it with transpyloric potential difference and pressure profile.

In contrast to the steady low intragastric pH, the pH in the proximal duodenum shows wide, rapid, and frequent fluctuations. This change in pH pattern may be used to localize the pylorus and thereby ensure reproducible measurements of duodenal pH at a known and reproducible distance from the pylorus. To validate this method of localizing the pylorus, simultaneous measurements were performed of the transpyloric pH and potential difference (PD) profile and of the pH and pressure profile in 10 normal subjects. pH-metry and PD-metry localized the pylorus within the same 1.5 cm in 82% of 104 5-min periods, and pH-metry and manometry localized the pylorus within the same 5 cm in 72% of 77 10-min periods. This agreement and accuracy seem satisfactory for most studies of intraluminal pH in the duodenum and make reliable long-term ambulatory recording of duodenal pH possible without serial roentgenogram controls.

Adult↗
PubMed1992

Is acute surgical vagotomy an aggressor to gastric mucosa in pylorus ligated rats with and without indomethacin treatment?

Previously it was proved that intact vagal nerve is basically necessary for the development of gastric cytoprotection. The aims of this study were to receive further data about the role of vagal nerve in the development of gastric mucosal damage. The observations were carried out on Sprague-Dawley rats. Acute bilateral surgical vagotomy was done with pylorus ligation and/or indomethacin (IND) treatment (20 mg/kg, sc.) at the time of operation. The animals were sacrificed 4 h after the operation. The number, the severity (semiquantitative method), the mean size and summed surface (computer assisted quantitative method) of gastric mucosal damage, the H+ output and the mucosal PGE2 level were determined. It has been found that 1) the ASV itself (without IND or pylorus ligation) provoked gastric mucosal damage, which was more severe than in the pylorus ligated animals at 4 h; 2) IND was able to reduce the summed surface of mucosal damage after ASV; 3) ASV aggravated the gastric mucosal damage in pylorus ligated animals in spite of the decreased H+ output; 4) the PGE2 level was lower in vagotomized and vagotomized+pylorus ligated animals then in the control group, and the IND did not cause further decrease in its level after ASV. It has been concluded that the balance between aggressive and defensive factors of gastric mucosa was shifted to the aggressive side in surgically vagotomized animals.

Animals↗
PubMed1984

[Ultrasonographic picture of the pylorus in infants].

The assessment of pylorus in the diagnostic procedure of causes of vomiting in infants is very important. The differentiation between organic and functional changes is principal. The survey covers 65 infants aged from 2 weeks to 12 months. In this group there are 14 vomiting neonates, in 6 of them the hypertrophic pyloric stenosis by ultrasound examination was diagnosed and by operation confirmed. Ultrasongraphy in presented children was performed on TOMOSONIC EUB--22 Hitachi (real time) provided with a 3 MHz transducer. The pylorus in children is localized near to the middline in the right epigastrium. In normal pylorus the walls of the canal widen the lumen opens. The diameter of normal pylorus amounts 10 to 15 mm, the thickness of muscular wall about 2 mm. In infants with the hypertrophic pyloric stenosis the three components: the muscle, the wall and the lumen of the canal are exceptionally visualized. The hypertrophied muscle forms a regular cylindrical sleeve around the canal and sometimes the pyloric lumen disappears. The diameter of the pyloric mass amounts about 15 to 30 mm and the thickness of the pyloric wall about 5 to 9 mm. The ultrasound examination let to assess the normal pylorus as well as with great probability to diagnose the hypertrophic pyloric stenosis eliminating also in many cases the conventional x-ray examinations.

Diagnosis, Differential↗
PubMed1984

To-and-fro movements across the canine pylorus.

A two marker technique was used to measure gastric emptying, duodenogastric reflux, and gastric volume secretion after intragastric instillation of a 300 ml liquid lipid meal in 11 dogs. The dogs either had an intact pylorus (n = 5), a Heineke -Mikulicz pyloroplasty (n = 3), or an extramucosal circular pylorectomy (n = 3). The mean gastric emptying rates in the three groups of dogs were 4.9 ml/min +/- 0.3 SEM, 5.7 +/- 0.2 (p less than 0.05), and 8.6 +/- 1.8 (p less than 0.01) respectively. The duodenogastric reflux rates were 0.7 ml/min +/- 0.2 SEM, 1.8 +/- 0.2 (p less than 0.05), and 3.2 +/- 1.0 (p less than 0.05), respectively. The gastric volume secretion did not significantly differ. Although emptying rates were higher in the dogs with surgically destroyed pylorus than in dogs with intact pylorus, the rate of disappearance of the test meal from the stomach was nearly identical in the three groups. This is due to the different degrees to-and-fro movements across the gastroduodenal junction. They amounted to 2.3 percent of the test meal +/- 1.0 SEM in dogs with intact pylorus, to 7.7 +/- 1.0 in dogs with pyloroplasty (p less than 0.05), and to 15.5 +/- 2.4 in dogs with pylorectomy (p less than 0.01). It is concluded that pyloroplasty and pylorectomy increase both gastric emptying and duodenogastric reflux rate. Simple assessment of the disappearance of a test meal from the stomach without measurement of to-and-fro movements cannot detect this effect on emptying rate. The pylorus keeps to-and-fro movements across the gastroduodenal junction at a low level.

Animals↗
PubMed1993

Pylorus-preserving pancreatoduodenectomy: technique and indications.

Pylorus-preserving pancreatoduodenectomy is accepted as definitive treatment of some malignancies, such as cancer of the duodenal papilla, and cancer of the lower bile duct. However, its use in cancer of the head of the pancreas is controversial. We have applied pylorus-preserving pancreatoduodenectomy combined with extended lymph node dissection as the major technique in cases of malignant disease. Also, when invasion of the portal vein is confirmed or suspected, portal vein resection has been combined. However, when the duodenal bulb or pyloric ring has been invaded by cancer, the classic Whipple operation has been indicated. Our experience over the last 11 years has demonstrated no statistical difference in the 5-year survival rate between patients with pancreatic head cancer treated with the Whipple procedure (n = 25, 34.8%) and pylorus-preserving pancreatoduodenectomy (n = 16, 33.3%). Also, the postoperative quality of life proved to be better in patients with pylorus-preserving pancreatoduodenectomy. These data support the continued application of pylorus-preserving pancreatoduodenectomy for the treatment of cancer of the head of the pancreas.

Gastrostomy↗
PubMed2005

Complications with reconstruction procedures in pylorus-preserving pancreaticoduodenectomy.

This study was conducted retrospectively to examine the efficacy of Traverso reconstruction compared with Billroth I reconstruction after pylorus-preserving pancreaticoduodenectomy, in the prevention of several complications. Pylorus-preserving pancreaticoduodenectomy is an aggressive surgery, and insufficiency of the pancreaticoenterostomy plays an important role in the postoperative progression. However, reports examining the correlation between pancreatic fistula and the type of reconstruction after pylorus-preserving pancreaticoduodenectomy have been limited. Sixty-four patients who underwent pylorus-preserving pancreaticoduodenectomy (33 reconstructed by the Traverso technique and 31 reconstructed by the Billroth I technique) were entered into this study to investigate whether the complications were related to the type of reconstruction procedure employed. Insufficiency of the pancreaticojejunostomy, including major leakage and pancreatic fistula, occurred in 18.2% of the reconstructions by Billroth I and 0% of the reconstructions by Traverso (p < 0.05). In addition, jejunal obstruction by recurrent tumor in the remnant pancreas was observed in 3 patients reconstructed by Billroth I, and required palliative bypass surgery. Reconstruction by the Traverso procedure after pylorus-preserving pancreaticoduodenectomy is a safe surgical method and has an advantage for advanced pancreatic cancer, which has high risk of jejunal obstruction by recurrent tumor in the remnant pancreas.

Aged↗
PubMed1989

Postprandial plasma gastrin and secretin concentrations after a pancreatoduodenectomy. A comparison between a pylorus-preserving pancreatoduodenectomy and the Whipple procedure.

Based on the observation that patients given a pylorus-preserving pancreatoduodenectomy maintain higher gut hormonal levels than do patients who have received the classic Whipple surgical procedure, which seems most likely due to a postoperative difference in the remaining digestive tract, the postprandial plasma gastrin and secretin concentrations in patients who have received either surgery have been evaluated to examine this difference more fully. The subjects were 20 patients treated by a pylorus-preserving operation and 27 patients treated by the Whipple procedure whose concentrations were compared with those of 8 healthy control patients. The postprandial plasma gastrin concentrations were found to be similar in patients given the pylorus-preserving operation and the controls and were significantly lower in patients who underwent the Whipple procedure (p less than 0.05). Similarly, the postprandial plasma secretin concentrations did not differ in these two groups, whereas patients who underwent the Whipple procedure showed significantly lower concentrations at 60, 90, and 120 minutes (p less than 0.05). The above findings, as well as supportive data in the literature, indicate that the duodenal bulb and the gastric antrum, which are resected in the Whipple procedure and are kept in the pylorus-preserving operation, seem to play important roles in the gut hormonal release and that the pylorus-preserving operation is the superior surgical technique in terms of gastrin and secretin release.

Duodenum↗
PubMed1994

A comparison of long term results of the standard Whipple procedure and the pylorus preserving pancreatoduodenectomy.

The standard Whipple procedure involves intestinal disturbances, such as dumping, diarrhea, dyspeptic complaints and the occurrence of ulcers of the anastomoses. A postoperative weight loss was observed ranging between 10 and 40 kilograms. Only a few patients were able to compensate after several months. It was thought that preservation of the intact stomach would prevent the complications arising from a loss of gastric reservoir function and thus the malnutrition could be improved postoperatively. Between 1985 and March 1992, we performed the pylorus-preserving Whipple procedure and treated a group of 43 patients with this method. In the same period, 15 patients were operated upon with the standard Whipple procedure. The present evaluation of the accumulated patient data, including extensive functional studies, led to the following results comparing the pylorus preserving Whipple procedure with the standard Whipple procedure. First, the capacity for food uptake and the development of body weight postoperatively is significantly better. Second, gastric or jejunal ulcers were not observed. Third, there were no clinical signs of digestive disorders, such as different forms of dumping. Nutrition and digestion were not impeded by the preserved opening mechanism of the pylorus. Fourth, the postoperative exocrine function was only slightly decreased. Fifth, glucose metabolism postoperatively was influenced only slightly by preservation of the pylorus. In taking the results of all the examinations into consideration, it can be said that the restricted organ loss in the Whipple procedure with pylorus preservation leaves the secretory and functional capacity of the upper part of the gastrointestinal tract almost unchanged.

Adult↗
PubMed1980

The peptidergic neural control of the feline pylorus.

By immunohistochemistry the three neuropeptides enkephalin, substance P, and VIP were all localized to numerous nerve fibers in the smooth muscle layer and the myenteric plexus of the feline pylorus. The motor activity of the pylorus was studied by recording changes in the volume flow of body-warm saline through the sphincter at constant perfusion pressure in anesthetized cats. Efferent electric stimulation of the cervical vagi (8 V; 5 ms; 8 Hz) elicited a noncholinergic, nonadrenergic pyloric contraction, which was blocked by infusion of the opiate receptor antagonist naloxone. The peptides were injected into a regional gastric artery to the pylorus antrum. Enkephalin and substance P in micronanomolar doses resulted in a prompt contraction of 3 - 5 min duration. Equimolar doses of naloxone blocked the enkephalin-induced contraction, and atropine blocked the SP contraction. On the other hand, VIP caused a prompt dilatation, which could not be blocked in this study. Altogether the findings suggest a peptidergic motor control of the feline pylorus using several transmission mechanisms.

Animals↗
PubMed1996

[Current indications for pylorus saving duodenopancreatic head resection in malignancy].

The Whipple procedure has been improved by preservation of a functioning pylorus. A functioning pylorus is important because marginal ulceration is avoided and, compared to the standard Whipple procedure with gastric resection, more patients can gain weight postoperatively. The most common indications are carcinomas of ampulla of Vater and periampullary tumors. In patients with pancreatic adenocarcinoma the pylorus-preserving variety results in equal or better survival rates. In 56 patients with pylorus preservation, 32 with ductal carcinoma, and 28 with Kausch-Whipple between 1985 and 1993, our results showed slightly better survival rates and better postoperative nutrition. The weakest aspect of the radical resection addresses the retroperitoneal margin of the pancreas head and not the gastric resection.

Adenocarcinoma↗
PubMed1977

Surgical vagotomy and stomach wall ATP and ADP in pylorus--ligated rats.

The stomach wall ATP and ADP have been studied in rats, with and without bilateral surgical vagotomy, 24 hr after pylorus ligation. It was observed that the amounts and concentrations of ATP significantly decreased in both parts (corpus + antrum and forestomach) in pylorus-ligated rats, while the amounts and concentrations remained at a significantly higher level in pylorus-ligated + vagotomized rats. Changes in amounts and concentrations of ADP paralleled those of ATP. It has been concluded that a significant decrease of cellular ATP is necessary to produce gastric hypersecretion in ulceration in pylorus-ligated rats. This significant decrease of cellular ATP, in corpus + antrum and forestomach, can be prevented by bilateral surgical vagotomy.

Adenosine Diphosphate↗
PubMed1976

A new model of stress ulcer in the rat with pylorus ligation and its pathogenesis.

Water-immersion stress for 7, 14, or 20 hr consistently induced linear or punctate stress ulcers (mucosal erosions) in the corpus of the stomach in intact rats. When the pylorus of the stomach had been ligated prior to stressing, the stress ulcers changed their morphological feature (mainly punctate and in one place elongated) and location (both in corpus and antrum). Histologically, the stress ulcer developed in the proximal antrum of pylorus ligated rats and penetrated into the muscularis mucosa. Sodium bicarbonate, chlorpromazine, hexamethonium, atropine, metiamide, and bilateral vagotomy markedly inhibited the stress ulcers which developed in the pylorus-ligated rats. Phentolamine and propranolol hardly affected the development of stress ulcers. Amylopectine evoked a new type of stress ulcer in the corpus when it was given to the pylorus-ligated rats.

Amylopectin↗
PubMed1984

The clinical significance and natural history of the double pylorus.

The double pylorus is a fistulous communication between the gastric antrum and duodenal bulb. In most instances, it is believed to be a complication of peptic ulcer disease. In prior reports, the longest follow-up has been only 5 years. We report four cases of double pylorus, three of which have been followed medically (one for 7 years), and a fourth which required surgery for recurrent pain after 10 years of medical treatment. In previously reported cases, only 20% have required surgery, usually for refractory symptoms, whereas 80% of patients have been managed medically and have been free of complications. In one of our cases, the mucosal bridge separating the pylorus from the fistula perforated, with coalescence of the two channels into one large gastroduodenal passage. There were no serious clinical symptoms or sequelae caused by this additional destruction of tissue. We conclude that the double pylorus is a destructive but relatively benign complication of peptic ulcer disease.

Aged↗