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Biomedical subjects

C Wahlen

Publications and source records attributed to C Wahlen.

At least 19 recordsLinked to original sources
PubMed2006

Laparoscopic treatment of Barrett's esophagus: long-term results.

BACKGROUND: Gastroesophageal reflux disease (GERD) is considered the main etiologic process in the metaplastic development of Barrett's esophagus (BE). The most serious complication of BE is the possible dysplastic evolution to esophageal carcinoma. Many treatments have been described to prevent the progression of BE. The outcomes of these interventions are controversial. The aim of this study was to assess whether laparoscopic fundoplication for GERD had an impact on the development of BE. METHODS: Prospective data were collected from patients who were treated with a laparoscopic fundoplication for BE. Data was collected and analyzed for a variety of clinical and pathologic outcomes. RESULTS: Laparoscopic fundoplications were completed between 1993 and 2001, with a total sample size of 92 (mean age 53 +/- 11.8 years). Each patient was diagnosed with GERD associated with BE confirmed by both endoscopy and biopsy. A laparoscopic fundoplication was performed in all patients (360 degree fundoplication in 81 patients and partial fundoplication in 11 patients). There was no postoperative mortality or major complications from the procedure. The mean postoperative stay was 3 +/- 1 days. Seventy patients (76% of the overall sample size) were followed up for a mean 4.2 +/- 2.6 years. Of the patients available for follow-up, 33% (n = 23) had a complete regression of their BE; 21% (n = 15) had a decrease in the degree of metaplasia/dysplasia; 39% (n = 27) had no significant change; and 7% (n = 5) experienced a progression of the BE. Five patients required further procedures for three reasons: (1) GERD recurrence (n = 2), (2) progression of BE (n = 2), and (3) intrathoracic migration (n = 1). No patients developed high-grade dysplasia or esophageal carcinoma. CONCLUSIONS: The results of this study suggest that laparoscopic fundoplication offers a safe and effective long-term treatment for BE. The procedure also demonstrated regression of BE in more than 50% of the sample size.

Adult↗
PubMed2005

Clinical results of laparoscopic fundoplication at ten years after surgery.

BACKGROUND: Several studies have demonstrated laparoscopic antireflux surgery (LAS) for the treatment of gastroesophageal reflux disease (GERD) to be efficient at short- and midterm follow-up evaluations. The aim of this study was to evaluate the results for LAS 10 years after surgery. METHODS: The 100 consecutive patients who underwent LAS by a single surgeon in 1993 were entered into a prospective database. Nissen fundoplication was performed for 68 patients, and partial posterior fundoplication (modified Toupet procedure) was performed for 32 patients. Evaluations of the outcome were made 5 and 10 years after surgery. A structured symptom questionnaire and upper gastrointestinal barium series were used at 5 years. The same questionnaire and an added quality-of-life questionnaire (the Gastrointestinal Quality of Life Index [GIQLI]) were used at 10 years. RESULTS: Seven patients died of unrelated causes during the 10-year period. Four patients underwent revision surgery: one patient for persistent dysphagia and three patients for recurrent reflux symptoms. Three patients were lost to any follow-up study. At 5 years, 93% of the patients were free of significant reflux symptoms. At 10 years, 89.5% of the patients still were free of significant reflux (93.3% after Nissen, 81.8% after Toupet). Major side effects (flatulence and abdominal distension) were related to "wind" problems. The GIQLI scores at 10 years were significantly better than the preoperative scores of the patients under medical therapy with proton pump inhibitors. CONCLUSIONS: Elimination of GERD symptoms improved quality of life and eliminated the need for daily acid suppression in most patients. These results, apparent 5 years after the operation, still were valid at 10 years.

Administration, Oral↗
PubMed2005

[Ghrelin and obesity].

Ghrelin is a peptide hormone secreted by the stomach. It was initially described as a stimulant of growth hormone secretion. Soon, however, it was discovered to play an important role in feeding behaviour in animals and in appetite regulation in man: ghrelin stimulates appetite, and as such is an orexigenic peptide implicated in energy balance mechanisms and weight gain. Abnormal ghrelin activity leads to over- or underweight. Additionally, the efficacy of different treatment strategies against obesity seems to be related to modifications in plasma ghrelin levels. This review summarizes the current knowledge about ghrelin and its implications in obesity medicine.

Ghrelin↗
PubMed2000

[Adenocarcinoma of the pancreas. Preoperative staging].

The authors assess the value of laparoscopy in the preoperative staging of the adenocarcinoma of the pancreas to prevent unnecessary pancreatic resections in a disseminated disease. By laparoscopy, a macroscopic evaluation, a peroperative liver and pancreas ultrasonography as well as biopsies are possible and are more accurate in assessing the extent of the disease than other means.

Biopsy↗
PubMed2000

[Adenocarcinoma of the pancreas. Palliative surgery].

In case of unresectable adenocarcinoma of the pancreas, laparoscopy can allow to perform gastric and biliary by-pass which will improve the quality of life at a lower cost than conventional surgery for the patients.

Adenocarcinoma↗
PubMed1992

[Acquired diverticulosis of the small bowel].

The authors report about their surgical experience? On the basis of one case of pneumascos and one case of gastrointestinal hemorrhage with collapse, for which no origin was found preoperatively and which was attributed to the presence of diverticula in the small bowel. The analysis of the literature shows that this rare condition (0.1% of the population) is mainly expressed as acute complications: diverticulitis, perforation, hemorrhage, obstruction. The treatment is surgical as a rule, but it can be medical if the condition is included in the scope of a malabsorption syndrome.

Aged↗
PubMed1989

Contribution of peripheral blood pooling to central hemodynamic disturbances during endotoxin insult in intact dogs.

The aim of the present study was to determine possible effects of Escherichia coli endotoxin on peripheral vascular compliance and relate them to concomitant central hemodynamic disturbances. Endotoxin was infused at 0.25 micrograms/kg.min during 2 h in six anesthetized dogs, while six additional animals served as controls. Vascular compliance of the systemic circulation was calculated in intact animals from the changes in CVP after known changes in systemic blood volume. In control dogs, vascular compliance averaged 2.3 ml/mm Hg.kg body weight. During slow endotoxin infusion, cardiovascular effects were measurable only after a certain period of time had elapsed from the start of endotoxin insult and consisted of hypotension associated with systemic vasodilation. Systemic BP decreased gradually from 124 to 68 mm Hg while vascular compliance was finally increased by 100%, when compared to control values. This latter rise was responsible for a reduction in the cardiac preloads. Pulmonary wedge pressure and CVP were decreased from 7.1 to 3.4 and from 4.5 to 2.6 mm Hg, respectively. However, parallel to the decrease in left ventricular preload, endotoxin induced a progressive decrease in left ventricular afterload. Because of the balance in ventricular loading, cardiac output remained almost unchanged. After volume loading (dextran 30 ml/kg), cardiac output was remarkably increased from 3.28 to 6.24 L/min.m2 while peripheral vasodilation was not affected by this maneuver. It is concluded that low dose endotoxin infusion induces in dogs a hemodynamic pattern similar to human sepsis. The left ventricular loading changes are related to an enhanced systemic vascular compliance from 2.3 to 4.5 ml/mm Hg.kg. High flow shock state is encountered provided peripheral blood pooling is compensated by adequate volume replacement.

Animals↗
PubMed1987

Effects of intravascular volume expansion on lung fluid balance in a canine model of septic shock.

We tested the early effects of endotoxin on both the permeability of capillary membranes and microvascular pressure. One group of dogs (n = 8) were fluid loaded (30 ml/kg dextran-40) after having been subjected to a 2-h Escherichia coli endotoxin infusion (0.25 micrograms/kg X min). A second control group of animals (n = 6) was submitted to a similar (25 ml/kg) volume loading over an equivalent 30-min period. We estimated extravascular lung water (EVLW), calculated the effective pulmonary capillary pressure, and determined the alveolar-capillary filtration coefficient (Kf) after volume loading. Only the septic animals consistently showed elevated EVLW values consistent with pulmonary edema. The results showed, however, that the Kf calculated for the dogs that received endotoxin was no different from that of control group (Kf = 0.005 ml/kg X min X mm Hg). Instead, endotoxin constricted the pulmonary veins which led to a considerable rise in microvascular hydrostatic pressure above the level at which the lungs could not resist edema formation. We conclude that acute pulmonary edema that follows endotoxin insult and subsequent therapeutic volume replacement is due to an increased filtration force instead of an alteration in the microvascular permeability.

Animals↗
PubMed1987

A comparison of Escherichia coli endotoxin single bolus injection with low-dose endotoxin infusion on pulmonary and systemic vascular changes.

The purpose of this study was to compare effects of single bolus endotoxin injection with sustained low-dose endotoxin infusion on systemic and pulmonary hemodynamics in anesthetized dogs. When administered as a bolus (.01 mg/kg), endotoxin induced systemic vascular changes whose evolution could be divided into two consecutive phases. In the early phase, marked hepatic venoconstriction caused a rise in portal pressure followed by abrupt decreases in both cardiac output and blood pressure. Mean pulmonary artery pressure remained unchanged. Because of lowered blood flow, both peripheral and pulmonary resistances increased. The rise in the latter was due to a prominent vasoconstriction of pulmonary arteries. Following a partial spontaneous recovery from shock, the late phase was characterized by a low-output state combined with high systemic vascular resistances. In contrast, when endotoxin was given at a slow infusion rate (250 ng/kg/min) over a 2-hour period of time, cardiovascular effects were basically different from the preceding ones, and they were measurable only after a certain period of time had elapsed from the start of endotoxin insult. First, blood pressure decreased gradually, while cardiac output remained almost unchanged. Therefore, peripheral resistance was decreased. Second, in the pulmonary circulation, the site of vasoconstriction was shifted from arteries to veins. We conclude that there is a fundamental difference in the response of the dog's systemic and pulmonary circulation as a function of endotoxin administration as either a bolus or slow infusion. This difference might be due to sudden elevated portal pressure responsible for an abrupt cardiovascular collapse in dogs subjected to bolus injection.

Animals↗
PubMed1987

Pulmonary hydrostatic microvascular pressure changes and lung fluid balance during histamine infusion in intact dogs.

The effects of histamine on systemic and pulmonary hemodynamics of dogs were studied in six intact animals. Histamine infusion resulted in an almost immediate, precipitous fall in blood pressure (BP), pulmonary capillary wedge pressure (PCWP), and right atrial pressure (RA) as well as an increase in heart rate. Partial recovery occurred about 5 minutes after infusion was stopped. Cardiac output did not change significantly. Consequently, the calculated peripheral resistance decreased afterwards. Hepatic portal pressure rose significantly after 2 minutes of histamine infusion with partial recovery in about 5 minutes. Suprahepatic venous pressure did not change significantly. Although pulmonary arterial pressure did not necessarily rise, total pulmonary vascular resistance increased in every dog. If the absolute level in pulmonary arterial resistance remained greater (Ra 105 mm Hg/liter-1 min X kg-1) than the level of venous resistance (Rv 70 mm Hg/liter-1 min X kg-1), the relative increase in venous resistance (100%) was higher than the increase in Ra (35%). On the other hand, effective capillary pulmonary pressure remained unchanged. Central blood volume and extravascular lung water increased upon histamine infusion and returned rapidly to baseline when histamine infusion was stopped. No significant changes occurred in either effective pulmonary compliance and arterial blood gas values. Our data lead us to conclude that histamine's major action occurs in the venous pulmonary segments; pulmonary and splanchnic blood pooling is responsible for a fall in cardiac preload; and an increase in extravascular lung water and central blood volume with unchanged effective pulmonary pressure might be explained by an increase in microvascular surface area.

Animals↗
PubMed1986

Effects of Escherichia coli endotoxin on pulmonary vascular resistance in intact dogs.

The effects of endotoxin on pulmonary hemodynamics were studied in seven intact dogs. The distribution of pulmonary vascular resistance was estimated by the effective pulmonary capillary pressure, which was derived from the pressure transient recorded while the pulmonary artery catheter was rapidly wedged. After the injection of endotoxin, cardiac output and aortic pressure consistently fell. Pulmonary artery occlusion (wedge) pressure also decreased, but not significantly. Although pulmonary artery pressure did not necessarily rise, total pulmonary vascular resistance increased in every dog. The absolute increase in pulmonary artery resistance was greater (142 mm Hg/L X min/kg); than in venous resistance (111 mm Hg/L X min/kg); however, the relative increase in venous resistance was higher (410% for venous resistance vs. 220% for pulmonary artery resistance). As a result of venoconstriction, there was a consistent increase in effective pulmonary capillary pressure (from 2.5 to 6.3 mm Hg). Our data indicate that the pulmonary vascular response to endotoxin injection is characterized by constriction of both pulmonary arteries and pulmonary veins. The capillary wedge pressure did not reflect the pulmonary microvascular pressure, since it varied in the opposite direction to the effective capillary pressure.

Animals↗
PubMed1984

Fundic vagotomy by waveguide CO2 laser: experimental study of a new technique in dogs.

Anterior lesser curve seromyotomy with posterior truncal vagotomy is an alternative operation to the highly selective vagotomy. After preoperative gastric function testing, four dogs underwent an anterior lesser curve seromyotomy with posterior truncal vagotomy. However, a new prototype hand-held laser was used to perform the seromyotomy. This laser delivers 20 W and is small, light, and highly maneuverable. Results of the operation indicate that this laser was easy to use and yielded a very effective seromyotomy without complications. Peroperatively, the laser performed simultaneous section and hemostasis. Postoperatively, no significant acid production could be stimulated with either histamine, pentagastrin, or insulin. This operation yields good control of acid production and is faster and easier than the highly selective vagotomy. The hand-held waveguide CO2 laser may further facilitate the ease of this procedure.

Animals↗