Palliativtherapie der malignen Ösophagusobstruktion mit selbstexpandierenden Metallendoprothesen

A total of 23 self-expanding metal stents were implanted in 17 patients (12 men, 5 women; mean age 66 [44-83] years) with inoperable malignant obstruction of the oesophagus or the oesophago-gastric junction. A primary success was achieved in all, a good functional result in 16 (94%). There were no complications. In the follow-up period (mean of 15.2 +/- 13 weeks) re-obstruction by the tumour process occurred in three patients. Twelve patients died after a mean survival time of 15.8 +/- 14 weeks. In ten of these the stent was still patent at death, while two had again developed dysphagia. The cumulative patency rate of the stents was 79%. These observations indicate that self-expanding metal stents can achieve satisfactory palliation in dysphagia due to a malignancy. The mortality and morbidity rates of the method seem to be less than those of other palliative measures.

A prospective trial of self-expanding metal stents in the palliation of malignant esophageal obstruction after failure of primary curative therapy

BACKGROUND

Self-expanding metal stents have been shown to be safe and effective for the primary palliation of patients with inoperable malignant esophageal obstruction. We sought to determine their safety and efficacy in patients who fail curative therapy.

METHODS

Seventeen patients with esophageal carcinoma who had recurrent dysphagia after radiation, surgery, or chemoradiation therapy for esophageal carcinoma were studied. All patients had recurrent dysphagia, and an uncovered metal stent was inserted for palliation. Patients were followed-up at 4-week intervals until death. Palliation was measured by a dysphagia score and the Karnofsky index.

RESULTS

Seventeen patients with recurrent dysphagia after primary treatment with surgery (n = 4), radiation (n = 11), and chemoradiation (n = 2) received uncovered Wallstents for palliation of dysphagia. The dysphagia score improved by at least 1 point in all patients. Thirteen of 17 patients had a 2 point improvement in the dysphagia score. The Karnofsky index improved significantly (from 58 +/- 3 to 66 +/- 3, p = 0.0002). Fourteen of the 17 patients had patent stents until death. Three of 12 patients (25%) died of stent-related complications (bleeding in 1, septic complications in 2 patients).

CONCLUSIONS

Patients with recurrence of esophageal carcinoma after surgery can be successfully treated with metal stents, but patients who have received radiation therapy with curative intent may be at greater risk for complications because of radiation-induced tumor necrosis and vascular changes in the esophageal wall. Larger prospective studies are necessary to clarify this issue.

Human tissue responses to metal stents implanted in vivo for the palliation of malignant stenoses

BACKGROUND

We sought to determine the histologic effects of metal stent placement on tumor tissue and on normal tissue proximal and distal to the tumor in patients with expandable metal stents implanted in vivo.

METHODS

Twelve patients with 10 to 16 mm uncovered Wallstents were studied, 5 with esophageal stents, 4 with biliary stents and 3 with antral-duodenal stents. Stent duration ranged from 18 days to 15 months. Eleven autopsy specimens and one surgical specimen were examined. The organs with the stent in place were removed, and histologic specimens were obtained using a special saw-microtome that cuts through the tissue and the material of the stent.

RESULTS

In all organs examined, the stent was incorporated into the material of the tumor to a varying degree. In the normal areas above and below the stenosis, the stent was incorporated into the wall of the organ and was covered by a collagenous reactive layer on the luminal aspect. The collagenous reaction was limited and did not cause exuberant growth or obstruction in any of the cases.

CONCLUSIONS

The struts of uncovered Wallstents of 10 to 16 mm in diameter migrate into the submucus space above and below the tumor, probably by pressure necrosis, and become incorporated into the wall of the organ.

Self-expanding metal stents for palliation of malignant esophageal obstruction--a pilot study of eight patients

We sought to determine whether the application of a self-expanding metal stent enables palliation of malignant dysphagia with minimal risk. The results of pilot studies from two centers are reported. We treated 8 inoperable patients with a 14 mm self-expanding metal stent (Wallstent). The stent was applied without general anesthesia under mild i.v. sedation. The procedure was successful in all cases. No side effects were noted. In one patient, tumor ingrowth through the meshes of the stent occurred. This patient was additionally treated with a percutaneous gastrostomy. One patient experienced tumor overgrowth of the proximal end, necessitating laser treatment. Three patients were still alive after three months. The mean number of cumulative endoscopic interventions per patient was 2.2 (SD: +/- 2; median 2). The mean observation time was 10.7 weeks +/- 2 (median 12). Dysphagia was graded from 0 (normal swallowing) to 4 (inability to swallow saliva). Dysphagia was significantly (p less than 0.0005) reduced from grade 3.1 (SD: +/- 0.35) to 0.5 (SD: +/- 0.5) immediately after stenting. 62.5% of the patients were able to manage a virtually normal diet (in one of these patients dysphagia recurred six weeks after stent placement due to tumor ingrowth). Six patients (75%) were able to ingest all necessary calories orally. The application of a 14 mm self-expanding metal stent in cases of inoperable malignant esophageal obstruction seems to offer safe and effective palliation of malignant dysphagia.

[Effect of nitrendipine on the function of the upper gastrointestinal tract]

A double-blind crossover-trial comparing the influence of orally administered nitrendipine and placebo on the function of the upper gastrointestinal tract was carried out in ten healthy volunteers. Esophageal motility, intestinal transit time, size and motility of the gallbladder, serum gastrin levels and gastric secretion (basal and after stimulation with pentagastrin) were determined. No statistically significant differences between nitrendipine and placebo could be observed. Most parameters remained unchanged in both groups. Serum gastrin levels slightly increased after nitrendipine but did not exceed the normal range. The results demonstrate that nitrendipine given in an antihypertensive dosage, in contrast to other calcium antagonists, does not influence the function of the upper gastrointestinal tract.

[Determination of gastric bicarbonate secretion in the human without acid suppression]

Gastric CO2/HCO3 was determined in absence of simultaneous inhibition of acid secretion by intra- and extragastric pCO2/pH measurements in 23 persons and calculated using the equation of Henderson-Hasselbalch. pCO2 was measured with use of a new electrode. The characteristics of the CO2 selective electrode membrane were tested in vitro. The CO2 selective membrane proved to be stable against 0.1 n HCl, gastric fluid with a pH of 1, and bile as well as mechanical irritations. 96.8 +/- 0.52% of given amounts of bicarbonate were detected in test fluids ranging in pH from 2.5-7.1. In gas and fluid, a linear relationship between given and measured bicarbonate of y = 0.97 x +1.03 with a correlation coefficient of 0.99 was observed. In vivo at pH less than 6, the intragastric pCO2 was significantly higher than that in venous blood. CO2 diffusion could be prevented by equilibration of intragastric pCO2 with venous pCO2. pCO2 was then measured in fluid as well as in reaspirated gas. Thus 94.6 +/- 8.8%, HCO3- that had been instilled intragastrically, could be detected. Without equilibration and resultant volume increase of the gas phase, bicarbonate secretion was 296.4 +/- 41.9 mumol/h under basal conditions and 520.8 +/- 252.8 mumol/h after acid stimulation. With equilibration, a bicarbonate secretion of 574.4 +/- 66.7 and 754.4 +/- 81.2 mumol/h was observed during basal and stimulated acid secretion. Our results indicate that bicarbonate measurements in absence of acid suppression require determination of CO2 in the fluid as well as in the gas phase.

Changes in the blood gas concentration caused by secretin and cholecystokinin. Indication of a vasomotor effect?

The assumption that secretin has a general vascular effect led to an investigation of the blood gas level in the peripheral veins and the acid/base balance under the influence of secretin (1 CU/kg/h, 0-120 min) and cholecystokinin (CCK) (1 IU/kg/h, 60-120 min) in a group of 10 volunteers. Six of the volunteers were subjected to a randomized, cross-over NaCl infusion study. With a secretin infusion alone (0-60 min) there was a transient, significant rise in PO2 (p less than 0.01) and oxygen saturation (p less than 0.05), which was no longer detectable after 60 min (p greater than 0.05). With an additional administration of CCK (60-120 min) and in the follow-up phase of observation (120-180 min) there was a significant fall in both parameters (120 min: p less than 0.05, 180 min: p less than 0.01). PCO2, HCO-3, and pH remained unaffected. The isolated increase in PO2 and O2 saturation may be attributed to vasodilation induced by secretin. The drop in both parameters under the influence of an additional infusion of CCK and in the follow-up phase of observation is linked to a possible vascular effect of CCK.

[Absence of effect of secretin and cholecystokinin on plasma concentrations of vasoactive intestinal polypeptide and pancreatic glucagon]

There is little information about the effect of peptides on the VIPergic system. Reports of the influence of secretin and cholecystokinin (CCK) on pancreatic alpha cells are contradictory. With the help of volunteers we investigated the influence of a new synthetic secretin (1 CU/kg/h, 0 to 120 min) alone and in combination with GIH-CCK (1 IU/kg/h, 60 to 120 min) on the concentrations of VIP (n = 13), pancreatic glucagon (PG) (n = 15) and blood sugar (n = 10). 6 of the volunteers were subjected to a randomized cross-over NaCl infusion study. Neither secretin (0 to 60 min) nor secretin and CCK (60 to 120 min) infusion caused a significant change in VIP (31 +/- 3 vs. 34 +/- 4.5 pg/ml, mean +/- SEM, p greater than 0.05), PG (102 +/- 9 vs. 116 +/- 12 vs. 114 +/- 12 pg/ml, p greater than 0.05) or blood sugar (about 90 mg/dl) concentrations. There is no evidence of an influence of secretin and CCK on te VIPergic system and the pancreatic alpha cells.

[Indication of the vasomotor effects of secretin and cholecystokinin by changes in blood gas concentration?]

The assumption that secretin has a general vascular effect led to an investigation of the blood gas level in the peripheral veins and the acid/base balance under the influence of secretin (1 CU/Kg/h, 0 to 120 mins) and cholecystokinin (1 IU/Kg/h, 60 to 120 mins) in a group of 10 volunteers. Six of the volunteers were subjected to a randomised crossover study under NaCl infusion. With a secretin infusion alone (0 to 60 mins) there was a transient, significant rise in PO2 (p less than 0.01) and oxygen saturation (p less than 0.05), which was no longer detectable after 60 minutes (p greater than 0.05). With an additional administration of cholecystokinin (60 to 120 mins) and in the follow-up phase of observation (120 to 180 mins) there was a significant fall in both parameters (120 min.: p less than 0.05, 180 min.: p less than 0.01). PCO2, HCO-3 and pH remained unaffected. The isolated increase in PO2 and O2 saturation may be attributed to vasodilation induced by secretin. The drop in both parameters under the influence of an additional infusion of cholecystokinin and in the follow-up phase of observation is linked to a possible vascular effect of cholecystokinin.

[Mesenteric lipodystrophy: differential diagnosis of a benign abdominal tumor]

In a clinical presentation of a patient with mesenteric lipodystrophy the usefulness of the two imaging procedures ultrasound and computeromography is firstly demonstrated. Both methods have proven as good means in early diagnosis and patients follow up. Combination of ultrasound and guided tumor puncture is able to establish diagnosis avoiding laparotomy. For the follow up of these patients ultrasound and computertomography are valuable.

[Effect of synthetic secretin and GIH-cholecystokinin on serum gastrin levels]

In response to the report of a false-positive increase in serum gastrin with the use of natural secretin (Boots), 11 test persons were enlisted in order to examine the effect of a new synthetic secretin (Hoechst), both alone and in combination with natural CCK, on serum gastrin concentration. 6 of the test persons were subjected to a randomised cross-over study under NaCl infusion. Under secretin (0 to 60 minutes) there was a significant fall in gastrin from 32 +/- 2.3 pg/ml to 23 +/- 2 pg/ml (p less than 0.01). When CCK was also administered (60 to 120 minutes) the gastrin level increased to 46 +/- 3.5 pg/ml (75 versus 0 minutes: p less than 0.01), 75 versus 60 minutes: p less than 0.001). At the end of the infusion the gastrin level had fallen significantly once more to 21 +/- 2 pg/ml (135 versus 120 minutes: p less than 0.001, 135 versus 0 minutes: p less than 0.01). On the basis of in vitro studies -- which revealed a cross-reaction of 2.4% - the increase in gastrin under CCK is not regarded as being due to cross-reaction with CCK but rather to contamination by other peptides.

[Endoscopy of the upper gastrointestinal tract: changes in the concentration of vasoactive intestinal polypeptide and gastrin?]

The report of a significant increase in plasma VIP concentration (PVC) during endoscopy of the upper gastrointestinal tract prompted us to examine this question under comparable experimental conditions, with simultaneous determination of serum gastrin concentration (SGC). Thirteen patients took part in a study wherein PVC and SGC were determined before, during and after oesophagogastroduodenoscopy (OGD). Before OGD the value for PVC was 30 +/- 2.5 pg/ml (means +/- SEM); during endoscopy it tended to increase slightly, to 35 +/- 3.2 pg/ml immediately after the examination (p greater than 0.05). By contrast with this finding, the SGC increased rapidly and significantly from 47 +/- 4.7 pg/ml prior to the examination to maximal values up to 68 +/- 6 pg/ml on inspection of the fundus (p less than 0,005), and was at a significantly increased level (p less than 0.05), with a value of 61.5 +/- 7.2 pg/ml, as much as thirty minutes after the examination. Sixty minutes after the examination the values had fallen to their original level (47.5 +/- 7.5 pg/ml). The present study shows that OGD has no significant influence on PVC, but that it is possible that stimulation of the VIP-ergic system is accompanied by a trivial increase in PVC. By contrast with this OGD significantly increases the concentration of endocrinally secreted gastrin, an effect which lasts as much as thirty minutes after the examination. The release of gastrin is a result of the combined effect of mechanical stimulation, distension due to insufflation of air and simultaneously induced neural influences. However, these mechanisms exert at most an insignificant influence on PVC - if indeed they have any effect on it at all.

[Secretin and cholecystokinin: hormonal action on the concentration of vasoactive intestinal polypeptide and gastrin in human subjects?]

There is little, and partially contradictory information about the mutual hormonal effects of peptides. With the help of volunteers we investigated the influence of a new synthetic secretin (1 CU/kg/h, 0 to 120 min.) alone and in combination with GIH-CCK (1 IU/kg/h, 60 to 120 min.) on the concentration of VIP (n = 13) and gastrin (n = 20). Six of the volunteers were subjected to a randomized cross-over study under NaCl infusion in which both peptides were determined. The VIP concentration was not significantly influenced (31 +/- 3 - 34 +/- 4 - 38 +/- 4.5 pg/ml, p greater than 0.05) by either secretin (0 to 60 min.) or by secretin and CCK (60 to 120 min.). In contrast, secretin induced a significant fall in the gastrin level (30 +/- 2 vs. 24 +/- 2 pg/ml, p less than 0.05). With an additional administration of CCK there was a significant rise in gastrin (75 min.: 46 +/- 3 pg/ml, p less than 0.005) with a decline in peptide levels at the end of the infusion (135 min.: 23 +/- 2 pg/ml, p less than 0.005). The cross reactivity with GIH-CCK and CCK-octapeptide was 2.4 and 3% respectively. The increase in gastrin is not regarded as being due to cross reaction with CCK. This may be due to either contamination of the CCK preparation by other peptides which exert an influence on the gastrin level or the CCK induced release of bile.

Histologic abnormalities in routine biopsies of patients with esophagitis and different gastric acid secretion

Intraepithelial eosinophilic granulocytes were previously reported to evidence prolonged acid reflux in patients with reflux esophagitis. The following study was performed to investigate whether or not these histologic abnormalities are specific to patients with esophagitis and high H+ ion activity of the gastric juice. Esophagitis was proved endoscopically in all patients. Biopsy specimens were obtained during endoscopy by forceps biopsy from the area involved. Afterwards an acid secretion test to determine basal and pentagastrin-stimulated H+ ion activity and a Bernstein test were performed. Histologic findings were correlated with the results of the acid secretion test. In this study, the occurrence of intraepithelial eosinophils was similar in patients with high and with low gastric acid output, but was overall low in these patients and has not proved to be a specific diagnostic criterion for reflux.

[Effect of diffusion potentials and various stomach regions on the behavior of the potential difference after pentagastrin]

Junction potentials at the tip of a 0.15 M NaCl- and a 3 M KCl-flowing bridge dependent on the surrounding electrolyte solution were measured and calculated. There was a close correlation between the calculated and measured junction potentials. The magnitude of the calculated and experimentally determined junction potentials at the tip of the 0.15 M NaCl-bridge was found to be almost identical. Provided that junction potentials were not subtracted from the measured potential difference pentagastrin diminished the simultaneous measured antrum and corpus potential difference in 11 volunteers. When however junction potentials from the experimentally determined potential difference had been subtracted pentagastrin induced a transient significant decline in the corpus potential difference but no significant changes of PD could be registered in the antrum. The observation that pentagastrin did not change the antrum-PD suggests that the pentagastrin effect is related to the parietal cells.

Effects of cimetidine and ranitidine on gastric transmural potential difference and on prolactin secretion in man

Endoscopically controlled measurement of gastric mucosal potential differences was performed in 50 subjects receiving ranitidine, cimetidine or normal saline. Significant maximum potential increases were recorded within 15 min of bolus injections of ranitidine in doses of 20 and 40 mg and cimetidine (200 and 400 mg). Under these conditions, ranitidine proved to be 12 times more potent than cimetidine, compared on a molar basis. There was a dose-related increase in serum prolactin concentration within 15 min of injection of 200 and 400 mg of cimetidine, while injections of 20 and 40 mg of ranitidine failed to enhance prolactin secretion. It would appear that the stimulatory effect of cimetidine on serum prolactin concentration is not mediated through its histamine H2-receptor antagonist activity.

[Significance of the correction of aspirated volumes for the results of the secretin-pancreozymin test (author's transl)]

A group of 123 patients without manifestation of an impaired pancreatic function was studied with the secretin-pancreozymin test (group I). In 54 patients (group II) the correction of aspirated volumes during the secretin-pancreozymin test was performed with polyethylene glycol 4000 (PEG) as a marker substance. The mean values of volume-, bicarbonate- and enzyme secretion showed higher levels in 7 of 9 parameters in group II. The recovery rate of polyethylene glycol in group II (median: 92% indicated, why there was no marked difference between both groups. If the secretin-pancreozymin test is performed according to the above method the correction of aspirated volumes becomes negligible for the determination of normal values. However single results of the secretin-pancreozymin test, especially pathological ones, can only be based on the correction of the aspirate.

[Effect of cimetidine on the transmural gastric mucosal potential difference including the histological pattern of the gastric mucosa (author's transl)]

The measurement of gastric mucosal potential difference (PD) has proved to be a good parameter in the observation of changes in the permeability and the ionic transport of the gastric mucosa. 48 volunteers were examined. The aim of the study was to show if cimetidine induced a dose-dependent increase in the potential difference and if this was infuenced by the different regions of the stomach and morphologic pattern of the gastric mucosa. After 100, 200 and 400 mg cimetidine intravenously there was a maximum increase of the potential difference in the different regions of the stomach and in the gastric juice independent from the dose schedule. No changes were seen in the duodenum. The extent of the increase in PD was dependent on the lesions of the gastric mucosa and the different regions of the stomach.