Biomedical subjects

J S Vassilakis

Publications and source records attributed to J S Vassilakis.

At least 37 records · Page 2Linked to original sources

PubMed1995

Anorectal function after low anterior resection of the rectum.

Impaired neorectal function or sphincter incompetence have been respectively implicated as causative factors of increased frequency of defaecation or incontinence after low anterior resection of the rectum (LARR) for rectal carcinoma, although individual mechanisms of anorectal function have not been fully studied. Functional and laboratory results were evaluated in 19 subjects, who had a LARR for rectal carcinoma before and after the procedure, and were compared to those of normal subjects. LARR worsened anorectal function, mostly by significantly increasing the daily number of defaecations (p < 0.001), while major incontinence was reported in three cases. Patients with rectal carcinoma have a decreased resting anal pressure on manometry, as compared to controls (p < 0.001). LARR further reduces anal resting pressure (p < 0.001) as well as all parameters that express internal sphincter activity, such as presence and amplitude of either slow (p < 0.05 and p < 0.01) or ultraslow waves. LARR also impaired external anal sphincter activity, as expressed by the reduction in anal squeeze pressure (p < 0.001). Anorectal sampling was found reduced in incidence and frequency in LARR patients as compared to controls (p < 0.01 and p < 0.001), and was impaired even further postoperatively (p < 0.001). Rectoanal inhibitory reflex was present in all but three patients postoperative, but significantly impaired as compared to controls. Rectal volumes to elicit transient or permanent desire to defecate, maximal tolerable rectal volume and rectal compliance were also significantly reduced after LARR (p < 0.001, p < 0.001, p < 0.01 and p < 0.001 respectively). Large bowel transit was significantly enhanced after LARR (p < 0.001).(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

PubMed1995

Effect of hiatal hernia on esophageal manometry and pH-metry in gastroesophageal reflux disease.

An increased frequency of reflux events and a prolonged acid clearance have been shown in gastroesophageal reflux (GER) patients with a hiatal hernia as compared to those without. The objective of the present study was to further investigate esophageal motility and patterns of reflux in GER patients, in relation to the presence or absence of hiatal hernia. Esophageal manometry and ambulatory 24-hr esophageal pH-metry were used in 42 patients with GER and 18 controls. Eighteen of the patients were considered to have a nonreducing hiatal hernia on endoscopy. Hiatal hernia patients showed a higher extent of reflux (total composite score, P = 0.016; total reflux time, P = 0.008, reflux time in supine position, P = 0.024; reflux time in upright position, P = 0.008), a lower frequency of reflux events (P = 0.005), a more severe esophagitis on endoscopy (P < 0.01) and a lower amplitude of peristalsis at 5 cm proximal to LES (P = 0.0009) as compared to patients without hiatal hernia. The amplitude of peristalsis at the distal esophagus was inversely related to the extent of reflux (P = 0.024). Acid clearance was also significantly prolonged in the hernia subgroup (P = 0.011). Although LES resting pressure did not differ significantly between the two subgroups of patients, it was inversely related to the extent of reflux in the patients with hiatal hernia (P = 0.0005). It is concluded, that GER patients with hiatal hernia present with an increased amount of reflux and more severe esophagitis, which results in more severely impaired esophageal peristalsis as compared to patients without hernia. Prolonged acid clearance and impaired esophageal emptying observed in patients with hiatal hernia could be the result of both the presence of the hernia itself and the reduced peristaltic activity of the esophagus.

Adult↗

PubMed1994

Gallbladder emptying after antiulcer gastric surgery.

It has been shown that truncal vagotomy with pyloroplasty (TVP), but not highly selective vagotomy (HSV), delays the onset, decreases the extent, and changes the pattern of gallbladder emptying. The aim of the present study was to investigate any alterations in gallbladder emptying after a variety of antiulcer gastric surgery, by milk-technetium 99m (99mTc)-dimethyl iminodiacetic acid (HIDA) scintigraphy. After excluding the cases with spontaneous gallbladder evacuation before milk ingestion, there were 26 controls, 41 duodenal ulcer (DU) patients, 22 after HSV (15 prospective cases), 50 after TVP (23 prospective cases), 8 after TV with gastrojejunostomy (TV-GJ), 10 after Billroth I gastrectomy, and 29 after Billroth II gastrectomy. None of the patients with gastrectomy had additional vagotomy. TVP significantly delayed the onset and decreased the rate of gallbladder emptying as compared with the control, DU, HSV, and Billroth I groups. TVP also changed the pattern of emptying in 20% of the cases (sequential emptying and refilling events). Antiulcer operations excluding the duodenum (TV-GJ and Billroth II) further reduced the rate of gallbladder emptying as compared with (1) control, DU, HSV, and Billroth I groups (P < 0.0001) and (2) TVP (P < 0.001). Onset of gallbladder emptying was not affected by Billroth II gastrectomy, but was significantly delayed by TV-GJ (P < 0.001). The latter two operations also significantly changed the pattern of gallbladder emptying, exhibiting sequential emptying and refilling events, in most cases (P < 0.01 versus TVP). In conclusion, all antiulcer procedures, except HSV, greatly disturb the pattern, the onset, and the rate of gallbladder emptying. Truncal vagotomy seems to disrupt vagally mediated preduodenal mechanism, resulting in delayed onset and reduced rate, whereas duodenal exclusion by gastrojejunostomy results in severely decreased rate of gallbladder emptying.

Duodenal Ulcer↗

PubMed1994

Roux-en-Y gastroenterostomy severely disturbs emptying of the gallbladder.

BACKGROUND: It is documented that truncal vagotomy and Billroth II gastroenterostomy disturbs the emptying of the gallbladder. The aim of the present prospective study was to assess the emptying of the gallbladder after Roux-en-Y gastroenterostomy. STUDY DESIGN: There were 34 patients, who had undergone either truncal vagotomy with pyloroplasty (TVP, 14 instances) or Billroth II gastrectomy (20 instances), and were subsequently subjected to Roux-en-Y gastroenterostomy. The emptying of the gallbladder was assessed before and after the Roux-en-Y procedure, by milk-technetium-99m labeled hepatoiminodiacetic acid (milk-99mTc-HIDA) scintigraphy. Milk-99mTc-HIDA scintigraphy was also performed on twenty-eight healthy subjects, who served as the control group. RESULTS: After excluding the subjects having spontaneous gallbladder evacuation before milk ingestion, there remained 26 subjects in the control group, 12 patients with TVP, and 19 with Billroth II gastrectomy. Truncal vagotomy with pyloroplasty was associated with delayed onset (p < 0.001) and decreased rate (p < 0.01) of emptying of the gallbladder compared with the control group. Truncal vagotomy with pyloroplasty also changed the normal pattern of emptying in two patients (sequential emptying and refilling events). Billroth II gastrectomy was associated with decreased extent and abnormal pattern of emptying compared with subjects in the control group (p < 0.0001) and patients having TVP. Roux-en-Y gastroenterostomy, performed upon patients with TVP, significantly increased lag phase duration (p < 0.001), decreased ejection fraction (p < 0.01), and changed the pattern of emptying of the gallbladder (p < 0.01). Roux-en-Y procedure performed upon patients with Billroth II gastrectomy significantly increased lag phase duration (p < 0.0001). CONCLUSIONS: Roux-en-Y gastroenterostomy severely disturbs all parameters of the emptying of the gallbladder.

Adult↗

PubMed1994

Reproducibility of gallbladder emptying scintigraphic studies.

UNLABELLED: This study was designed to investigate the reproducibility of the results obtained from 99mTc-dimethyliminodiacetic acid (99mTc-EHIDA) cholescintigraphy, when used as a method of estimating gallbladder emptying. METHODS: In a random controlled fashion, the reproducibility of scintigraphic gallbladder emptying studies was assessed in 30 subjects, of whom six were normal, four had duodenal ulcers and the remaining 20 had undergone antiulcer gastric surgery. In fasting subjects, who 30 min later drank 250 ml of fresh milk, 2 mCi of 99mTc-EHIDA was intravenously injected. Liver and gallbladder areas were scanned for 60 sec and then every 5 min for 1 hr. The study was repeated in all subjects within 2-5 wk. From the gallbladder emptying curves, the duration of the lag phase (time from milk ingestion to actual start of emptying), the ejection fraction of emptying (peak to least activity in the gallbladder), the time by which maximal emptying was achieved and the pattern of gallbladder emptying were calculated. RESULTS: Two subjects were excluded from the study because their gallbladders did not fill. Lag phase duration was well reproduced in duplicate studies (r = 0.87), as was ejection fraction (r = 0.84). The time by which maximal emptying was achieved was not sufficiently reproduced. The normal pattern of emptying (exponential function) was reproduced in all controls, subjects with duodenal ulcers and patients after antiulcer surgery that did not involve duodenal exclusion. The abnormal pattern of emptying, characterized by refilling, was reproduced in five of the seven patients with gastric surgery that mainly involved duodenal exclusion. CONCLUSION: Scintigraphy with 99mTc-EHIDA to assess gallbladder motility is a method with satisfactory reproducibility of both parametric variables and patterns of emptying.

Duodenal Ulcer↗

PubMed1993

Anal manometry in patients with fissure-in-ano before and after internal sphincterotomy.

The motility pattern of the internal anal sphincter was estimated manometrically in 42 patients with fissure-in-ano before and after left lateral internal sphincterotomy (LAS). Resting anal pressure and anal pressure during straining were significantly higher in patients than in controls (132 +/- 21 SD cmH2O vs 81 +/- 14 SD cmH2O P < 0.0002 and 46 +/- 16 SD cmH2O vs 13 +/- 4 SD cmH2O P < 0.0005), but were normal after LAS. Slow waves were more common in fissure patients (86 +/- 6 SD% of total recording time vs 68 +/- 11 SD% of total recording time, P < 0.0002), but also became normal after successful treatment. The presence of ultra slow waves was also more common in fissure patients (P < 0.0001), and although it was significantly reduced postoperatively (P < 0.0001), it did not return to normal. Sampling was less frequent in fissure patients (P < 0.0001) and improved significantly after successful treatment (P < 0.0002). Rectal distension produced significantly less reduction in anal pressure in fissure patients as compared to controls (P < 0.01), but successful treatment returned the response to normal. There were 2 patients with anal fissure who did not heal after left LAS. Those patients and a further 5 patients with non healed fissures after left LAS showed the same pathological manometric features as before surgery. Their fissures were successfully treated by additional right lateral internal sphincterotomy. In conclusion, increased internal sphincter activity is probably an aetiological factor in fissure-in-ano, while successful LAS improves anal sphincter function.(ABSTRACT TRUNCATED AT 250 WORDS)

Anal Canal↗

PubMed1993

Differences in manometry and 24-H ambulatory pH-metry between patients with and without endoscopic or histological esophagitis in gastroesophageal reflux disease.

UNLABELLED: In this study, our objective was to examine prospectively, by endoscopy and histology of the esophageal mucosa, the severity of reflux esophagitis and any possible correlation between endoscopic and histological findings on the one hand, and manometric and 24-h ambulatory pH-metry measurements on the other. Forty-two patients with gastroesophageal reflux were prospectively examined. The results were compared with those of 18 healthy controls. Methods used were: 1) upper alimentary endoscopy and grading of severity of esophagitis, 2) esophageal mucosa biopsies, to estimate severity of esophagitis on histology, 3) standard esophageal manometry, by using a water perfused catheter with four side holes, and 4) standard 24-h ambulatory esophageal pH-metry. RESULTS: The severity of esophagitis as determined by both endoscopy and histology was significantly inversely related to the amplitude (p < 0.001) and duration (p < 0.01) of esophageal peristalsis at 5 cm proximal to LES; it was significantly related to the pH-metry total composite score (p < 0.001 for endoscopy, p < 0.05-0.01 for histology), the total reflux time (p < 0.001 for endoscopy, p < 0.01 for histology), the duration of longest reflux episode (p < 0.001 for endoscopy, p < 0.01 for histology), the number of reflux episodes lasting more than 5 min (p < 0.05 for endoscopy), and the frequency-duration index of reflux episodes (p < 0.001 for endoscopy, p < 0.01 for histology). Furthermore, strength reduction of peristalsis (< 60 mm Hg x s) was associated with acid exposure greater than 40%, in esophagitis patients. We conclude that the severity of reflux esophagitis, not only through endoscopy but also histologically, is related to the amount of reflux, as expressed by the duration and frequency of the reflux episodes. A very high amount of reflux is in turn associated with impairment of the esophageal body motility, as expressed by the amplitude and strength of esophageal body peristalsis.

Adult↗

PubMed1993

The effect of floppy Nissen fundoplication on esophageal and gastric motility in gastroesophageal reflux.

Thirty-five patients with gastroesophageal reflux (GER) proved on ambulatory esophageal hydrogen monitoring were surgically treated by a floppy Nissen fundoplication. Postoperatively, reflux and symptoms related to it were almost completely abolished. Transient bloating syndrome was observed in five instances. The operation significantly improved esophagitis (p < 0.01), increased lower esophageal sphincter pressure (p < 0.01) and increased amplitude of esophageal peristalsis (p < 0.01). However, postoperative motility of the esophagus as detected by manometry was still impaired as compared with that for the control group. Delayed esophageal transit did not improve postoperatively, although no dysphagia was accounted. Impaired esophageal motility in GER was associated with delayed gastric emptying, which, however, improved postoperatively. It is concluded that esophageal and gastric motor abnormalities are rather primary disorders in GER. After successful fundoplication, esophageal dysmotility, aggravated by reflux esophagitis, improves to some extent, while gastric emptying is enhanced.

Adult↗

PubMed1993

The effect of erythromycin in gastric emptying of solids and hypertonic liquids in healthy subjects.

We report our study of the effect of erythromycin on gastric emptying of solid and liquid meals in 10 healthy subjects. On different occasions, subjects consumed either a radiolabeled 50% glucose solution, or a radiolabeled standard solid meal after placebo, and after receiving 200 mg of erythromycin intravenously. Erythromycin accelerated the gastric emptying of the hypertonic liquid meal by significantly decreasing the duration of lag phase (p < 0.0001), by significantly increasing the emptying rate at the postlag period (p < 0.001), and by significantly decreasing the duration of the postlag period (p < 0.0001) and the meal remaining in the stomach at 15 (p < 0.05), 30 (p < 0.001), and 60 (p < 0.01) min postprandially. In addition, erythromycin administration induced a significant plasma fall at 15 (p < 0.05) and 30 (p < 0.01) min and a significant increase in pulse rate at 15 and 30 min (p < 0.01) after consumption of the hypertonic glucose solution, whereas three subjects experienced symptoms suggesting dumping syndrome. Furthermore, erythromycin administration enhanced the gastric emptying of solids by almost abolishing the duration of lag phase (p < 0.0001) and by reducing the overall t1/2 of emptying (p < 0.0001), whereas less food was retained in the stomach at 60 (p < 0.001) and 120 (p < 0.0001) min postprandially. Conversely, the postlag t1/2 of the solid meal emptying was not affected by erythromycin, as compared to placebo. We conclude that erythromycin has gastrokinetic properties, affecting the gastric emptying of both liquids and solids.

Adult↗

PubMed1992

Erythromycin accelerates delayed gastric emptying of solids in patients after truncal vagotomy and pyloroplasty.

OBJECTIVE: To find out if erythromycin (a motilin agonist) accelerated gastric emptying after vagotomy and in normal subjects. DESIGN: Double blind controlled study. SETTING: Two referral centres. SUBJECTS: 15 patients who had previously undergone vagotomy and who did (n = 8) or did not (n = 7) have symptoms of gastric stasis and 10 normal controls. INTERVENTIONS: A standard meal containing 185 x 10(5) Bq -99mTc was eaten after either erythromycin 200 mg or 40 ml placebo (normal saline) had been given intravenously. Subjects were then scanned by gamma camera. MAIN OUTCOME MEASURES: Measurement of: the length of time from completion of the meal to the onset of gastric emptying; the length of time from completion of the meal until half of the meal had left the stomach; the length of the time from the onset of gastric emptying until half of the meal had left the stomach; and the percentage of the meal that was left in the stomach at 60 and 120 min after the end of the meal. RESULTS: Gastric emptying was significantly delayed in those patients with symptoms compared with normal subjects and patients without symptoms. Erythromycin accelerated the first two phases of gastric emptying in all patients and normal subjects, but did not affect the length of time from the onset of gastric emptying until half the meal had left the stomach. CONCLUSION: Erythromycin could be a useful gastrokinetic agent in patients with symptoms of gastric stasis after vagotomy.

Adult↗

PubMed1992

Surgical treatment of the enterogastric reflux syndrome: preoperative and postoperative estimation by 99mTc-HIDA scintigraphy.

Twenty-nine patients with enterogastric reflux syndrome after anti-ulcer gastric surgery underwent a revisional Roux-en-Y gastrectomy. The diagnosis of enterogastric reflux syndrome was based on symptomatology and endoscopy in the first eight patients. The latter 21 patients had, in addition, a 99mTc-HIDA scintigraphy for the documentation and measurement of reflux. An enterogastric reflux index > 20 per cent is considered to justify symptoms due to reflux. Three of the first eight patients continued postoperatively to experience the same symptoms as before. These symptoms were eventually attributed to other than enterogastric reflux syndromes. The latter 21 patients were relieved from their preoperative symptoms and classified as Visick I and II (18 patients) and Visick III (3 patients). The authors conclude that enterogastric reflux syndrome must be documented on scintigraphy before the patient is subjected to revisional anti-reflux surgery in order for failures due to misdiagnosis to be avoided.

Adult↗

PubMed1991

Enterogastric reflux after various types of antiulcer gastric surgery: quantitation by 99mTc-HIDA scintigraphy.

In 28 controls and 142 patients subjected to a variety of antiulcer procedures, the enterogastric reflux (EGR) was quantitated by 99mTc-HIDA scintigraphy and expressed as the EGR index on 229 different occasions. The EGR index was calculated according to two different formulas: one based on the maximal radioactivity over the gastric area as a percentage value of the total abdominal activity (EGR-Im) and the other based on the relative maximal radioactivity over the gastric area as a percentage value of the relative hepatobiliary activity (EGR-It). There was a significant positive correlation of values between the two methods (P less than 0.0001). In patients with an EGR-Im greater than 20% or EGR-It greater than 57% and postgastric surgery symptoms some of the symptoms were attributed to EGR, an antireflux procedure is expected to relieve those symptoms. Sixteen of these patients underwent Roux-en-Y gastrectomy and their preoperative symptoms were relieved.

Duodenal Ulcer↗

PubMed1991

Hydatid disease of the liver. Diagnosis and surgical treatment.

A series of 155 cases of hepatic hydatid disease, occurring in 121 patients, were operated on at the Naval and Veterans Hospital of Athens. Ultrasonography and computerized axial tomography provided the preoperative diagnosis in 89 and 93 percent of the cases respectively in recent years. Thirty one percent of the cases presented with complications, the commonest of these being infection of the cyst (10 percent) and rupture of the cyst into the bile ducts (17 percent). Total cystectomy was performed in three cases and removal of the endocyst with its content in the remaining 152. The remaining cavity was either externally drained (57 cases), or filled with omentum (omentoplasty--95 cases). External fistula and infection of the residual cavity occurred in 32 and 56 percent after simple drainage and in 4 and 2 percent respectively after omentoplasty. Differences are statistically significant (p less than 0.001). Hospitalization was also significantly longer after drainage than after omentoplasty (p less than 0.01). Obstructive jaundice after intrabiliary rupture of the cyst was more successfully managed after additional choledochoduodenostomy than after simple drainage of the common bile duct. Intrapericoneal recurrence of hydatid disease occurred in two cases. The conclusion of the present study is, that ultrasonography and computerized axial tomography provide an acceptable rate in the diagnosis and that omentoplasty offers a very low complication rate in the management of hydatid cystic disease of the liver.

Adult↗

PubMed1990

Serum and urine alpha--amylase isoenzymes levels after operative cholangiogram. A prospective clinical and biochemical study.

Serum and urine total alpha-amylase isoenzymes values were estimated in two groups of patients, who underwent either elective cholecystectomy and operative cholangiogram (group A-59 patients) or cholecystectomy without operative cholangiogram (group B - 68 patients). Serum and urine total alpha-amylase and pancreatic isoamylase (p-type) values were statistically significantly increased within the first 24 postoperative hours as compared to the preoperative levels only in group A (p less than 0.05). No clinical signs of pancreatitis were observed. Serum lipase alterations did not reach any statistically significant difference in either group. It is concluded that transient hyperamylasaemia after preoperative cholangiogram may be due to a reversible chemical pancreatitis caused by the infused opacifying agent into the common bile duct.

Adult↗

PubMed1990

Varicosis coli totalis: report of a case of idiopathic aetiology.

A case of colonic varices manifesting with rectal bleeding in a young patient is presented. There was no evidence of portal hypertension or any other cause. Familial history was also negative. Diagnosis was established by barium enema, colonoscopy and angiography. On colonoscopy, varices involved the entire colon. At operation, dilatation of the subserosal small veins of the entire small and large bowel was confirmed. The patient underwent a subtotal colectomy with ileorectal anastomosis with satisfactory result.

Adult↗

PubMed1989

Distribution of G-cells in the antrum and duodenum and D-cells in the fundus, antrum, duodenum and pancreas of the guinea pig.

Antral and duodenal G-cells and fundic, antral, duodenal and pancreatic D-cells were demonstrated immunocytochemically and their population size was estimated in guinea pigs of both sexes. The population of antral (210 + 18.03 SD cells/cm) and duodenal (13.20 + 3.12 SD cells/cm) G-cells is lower in guinea pigs than in dogs. Antral and duodenal G/D-cell ratios (1.6/1 and 1.2/1) are also lower in the guinea pig than in man. Antral G- and D-cell populations are greater in male (210 + 18.03 SD cells/cm and 128.2 + 17.63 SD cells/cm) than in female (176 + 13.8 SD cells/cm and 108.4 + 6.9 SD cells/cm) guinea pigs. The percentage of pancreatic D-cells is greater in the guinea pig (20-25%) than in man and rat. It is concluded that the differences in gastric and duodenal G- and D-cells between guinea pigs and other species possibly reflect different gastric secretory functions. Sex related differences in the endogenous sex hormones can explain differences in gastric secretion between the two sexes. Pancreatic D-cells possibly exert their action on neighbouring endocrine cells through different pathways from those seen in man and rat.

Animals↗

PubMed1989

Vagotomy for duodenal ulcer resistant to H2-receptor antagonists.

One hundred and twenty-seven male patients were subjected to antiulcer surgery for duodenal ulcer resistant to H2-receptor antagonist treatment. Fifty-four (group A) had been on conservative treatment for up to 6 months, while the remaining 73 (group B) had been on conservative treatment for more than 6 and up to 20 months. Of the group A, 43 underwent truncal vagotomy with pyloroplasty (group A1) and 11 highly selective vagotomy (group A2). Of group B, 52 underwent truncal vagotomy with pyloroplasty (group B1) and 21 highly selective vagotomy (group B2). Follow-up ranged between 18 and 72 months (mean 37 months). There were one ulcer recurrence in group A1, none in group A2, nine in group B1 and five in group B2, the difference between group A and group B being statistically significant (p less than 0.05). There was significantly higher nonulcer-associated morbidity after truncal than after highly selective vagotomy (p less than 0.05). No significant difference in the degree of peak acid output reduction was observed between the patients with and those without ulcer recurrence. These findings show that the administration of H2-receptor antagonists for more than 6 months in duodenal ulcer patients who, however, fail to have their ulcer healed is associated with high recurrence rate after vagotomy. It is suggested that such patients should undergo vagotomy as soon as they fulfill the criteria of resistance to H2-receptor antagonists. If conservative treatment has lasted for more than 6 months, vagotomy plus antrectomy has to be considered as the surgical treatment for these patients, with the possible cost of higher nonulcer-associated morbidity.

Adult↗

PubMed1989

Alterations in pancreatic B-, A- and D-cell populations following administration of corticosteroids. Immunocytochemical study in rats.

Prednisolone was administered to two groups of rats for 2 or 4 weeks, respectively. A third group served for control. Serum glucose and insulin levels were measured, and changes in population size along with alterations in staining density of the intracellular granules in pancreatic B-, A- and D-cells were assessed. Two weeks of prednisolone treatment induced significant increases in the staining density of the intracellular granules of B- and D-cells as well as the population size of A-cells, while significant hyperglucosaemia and hyperinsulinaemia were observed. Four weeks of prednisolone administration induced significant increases in population size of B- and D-cells and significant decrease in the population size of A-cells, while hyperglucosaemia and hyperinsulinaemia were even greater. It is concluded that corticosteroids cause an increase in pancreatic B-cell activity and, eventually A-cell numerical atrophy by altering the glucose metabolism. The changes in activity of D-cells possibly reflect functional adaptation to increased B-cell activity.

Animals↗