Search PubMed⌕ Search

Biomedical subjects

G Feifel

Publications and source records attributed to G Feifel.

At least 55 records · Page 3Linked to original sources
PubMed1997

Effects of somatostatin (SMS) on pancreatic microcirculation.

The effect of bolus infusion of increasing somatostatin (SMS) concentrations (1, 10, 100, 200 micrograms/100 g body wt) on pancreatic microcirculation and pancreatic tissue PO2 were investigated by using in vivo epifluorescence microscopy and a polarographic PO2 measurement technique. Additionally, the microperfusion of the pancreas, liver, spleen, stomach, and duodenum was measured by a laser Doppler device. Bolus infusion of SMS caused a significant, transient, and dose-dependent decrease in pancreatic capillary RBC velocities (to 50% of baseline) and acinar capillary overall perfusion (to 20% of baseline), which was not caused by a macrocirculatory depression. This pronounced decrease in microperfusion was not paralleled by a decline in tissue PO2. Laser Doppler measurements revealed that pancreatic and gastric microperfusion were reduced only at maximal SMS concentrations, considering that microperfusion of the liver, spleen, and duodenum was not altered. Therefore, we found further evidence that circulatory adjustment might occur during SMS inhibited secretory activity of the exocrine pancreas.

Animals↗
PubMed1997

Acute pancreatitis in rats: effects of sodium taurocholate, CCK-8, and Sec on pancreatic microcirculation.

With use of in vivo microscopy, pancreatic duct permeability, red blood cell (RBC) velocities, functional capillary density (FCD), and overall changes in capillary blood flow (perfusion index) were estimated after intraductal infusion of sodium taurocholate (0.8 ml, 4%) alone or in combination with systemic administration of cholecystokinin (CCK, 0.3 microg/100 g body wt) or secretin (Sec, 10 microg/100 g body wt). Sodium taurocholate mediated a significant increase in pancreatic duct and capillary permeability within 105 +/- 26 s followed by a transient decrease in RBC velocities and a sustained decrease in FCD, which were paralleled by dramatic flow heterogeneity. Therefore, a significant reduction in overall capillary blood flow was calculated. CCK stimulation aggravated the microcirculatory failure due to a decrease in RBC velocities, which was accompanied by an increase in acinar cellular necrosis. Sec stimulation attenuated microcirculatory failure due to a more moderate reduction of FCD. The enhanced pancreatic duct and capillary permeability, which enables free diffusion of pancreatic digestive enzymes into the parenchyma, is the initiating event in acute biliary pancreatitis, causing microcirculatory failure and tissue damage. The microcirculatory changes are secondary and a propagating factor for the development of acini necrosis. Stimulation with CCK worsened the course of acute biliary pancreatitis.

Acute Disease↗
PubMed1997

Long-term function of experimental substitutes of the ileocecal valve.

The bacteriological barrier function of the ileocecal valve (ICV) can be replaced according to the principle of the nipple-valve anastomosis. Since late complications due to technical measures for stabilizing the ileal nipple have been hitherto unknown, 12 adult beagle dogs were operated on by three technical modifications of a nipple-valve anastomosis and were followed up for 1 year: In three cases the ileal nipple was stabilized by longitudinal staples (NVA), in three cases an intestinal neosphincter (INS) was produced by healing of the muscular layers between the ileal nipple and colon, and in six cases an oral zone of stabilization, preserving an aboral valve zone (S-NVA) was constructed. Measures for valve function at the end of the study period were the weight course of the animals and the intestinal bacterial profile, considering morphological complications of the substituted valves. As reference the respective bacterial counts in ICV and end-to-end anastomosis (EEA) were used, which had been determined in the same animals in earlier experiments. Following an initial increase in weight the 3 animals with NVA and the three animals with INS continuously lost weight from the 4th postoperative month onward. The 6 animals with S-NVA, however, showed from the 4th postoperative month onward a significantly higher weight level (p < 0.05), which remained constant up to the end of the 1-year observation period. Because of a morphologically intact structure of the substituted valve a significantly (p < 0.05) better bacteriological clearance of the ileum was confirmed in these animals after 12 months when compared with the EEA group. In contrast, in the NVA and INS animals a severe bacterial overgrowth of the entire small intestine was observed. This was caused by an intestinal stagnation due to partial prolapse of the nipple in NVA and due to fibrotic stenosis in INS. The results of our study suggest that technical measures to relieve the tendency to devaginate are only successful, if they do not lead to obstruction of the orthograde intestinal passage in the long term. Thus, only the clinical introduction of the S-NVA model may be justified.

Animals↗
PubMed1997

[Laparoscopic cholecystectomy--effect of position changes and CO2 pneumoperitoneum on hemodynamic, respiratory and endocrinologic parameters].

UNLABELLED: The effect of laparoscopic cholecystectomy on cardiopulmonary and endocrinological parameters results from various factors such as increased intraabdominal pressure (IAP), CO2, and the positioning. However, positioning has not yet been regarded. Reliable examination of the individual influencing factors requires standardized anesthesiological procedure and constant IAP. Presently, the effect of positioning is observed separately from those effects caused by the pneumoperitoneum with CO2 (PP) under standardized conditions. METHODS: 40 patients with no history of cardiopulmonary disease were analyzed. Preoperative medication, induction and management of general anesthesia, positioning of the patient and IAP (12 mmHg) were standardized. Hemodynamic, respiratory and endocrinological parameters were determined with the patient in a supine position and in the position typical for the procedure (15 degrees head-down and 10 degrees slant to the left), each with and without PP. Heart rate (ECG), endexpiratory pCO2 (peECO2), invasive blood pressure (radial art.), central venous pressure, partial arterial O2 saturation (psaO2), and ventilation pressures (peak, plateau) were monitored throughout anesthesia. The parameters pH, pCO2, BE, HCO3-, COHb, vasopressin, lactate, and ammonia were analysed in arterial and venous blood samples at predetermined set points: base line, 10 min after CO2 insufflation, 10 min after desufflation, and 1 h after extubation (cf. table 1). Statistical analysis was performed using the Wilcoxon-test with p < or = 0.05 considered statistically significant. RESULTS: Insufflation of CO2 lead to a 12% increase of heart rate in supine position and to even 18% in the position required for surgery. Same significant changes were observed for arterial blood pressure (21 or respectively 28%). Central venous pressure increased by more than 200% after CO2 insufflation. Endexpiratory pCO2 increased by 2.4 mmHg after CO2 insufflation in the supine position and by 5 mmHg in the surgical position. Ventilation pressures increased significantly by 16%. Analysis of the effect of PP on blood gases showed that pH decreased from 7.47 to 7.43, and arterial pCO2 increased by 5.1 mmHg to 38.7 mmHg and increased further after desufflation to values of up to 43.9 mmHg. Arterial pO2 decreased steadily (18% after insufflation). Vasopressin plasma levels increased exponentially from 3.03 to maximal values of 104.45 pg/ml. Ammonia and lactate showed the expected, nearly identical course. Lactate increased within the clinically and methodically irrelevative range, from 1.12 to 1.159 mmol/l. Ammonia decreased by 29%. CONCLUSIONS: The observed changes, i.e. heart rate, central venous pressure, and arterial blood pressure are caused and altered by CO2 insufflation and the various positioning of patients. The increased vasopressin concentration more than likely contributes to these changes. The query whether the position of the patient also causes a change in respiratory parameters and blood gas analysis cannot be differentiated except for the end-tidal pCO2. Inspite of the observed changes no cardiopulmonary complications occurred in this patient group. Therefore, it seems possible to omit invasive monitoring in cardiopulmonary healthy patients. In patients with concomitant history of cardiopulmonary disease, however, deteriorations due to laparoscopy should be thoroughly taken into consideration and studied further.

Acid-Base Equilibrium↗
PubMed1996

Biomechanical stabilization of the nipple valve in continent ileostomy.

Despite stapler stabilization, sliding complication of nipple valve function occur in 19 per cent of continent ileostomies. Because the tendency of the ileum to desuscept is triggered by traction forces on the mesentery of the nipple during filling of the reservoir, a technique was developed to neutralize this biomechanical strain. In addition, to obtain fibrous healing between the muscular layers, the mucosa of contacting intestinal walls was removed by selective ultrasonic fragmentation. The valves of 18 consecutive patients were operated on with this technique. In six of these, a sliding valve was restabilized in a median time of 1.2 (range 0.4-2.9) years after conventional construction of the pouch. All are functioning well after a median of 4.6 (range 3.0-6.0) years. Between 1.8 and 4.8 years after operation a healed area between the musculature of the nipple and pouch of 4.5-7.2 cm2 was shown by endosonography. This procedure may provide long-term prevention of sliding complications in continent ileostomies.

Adenomatous Polyposis Coli↗
PubMed1996

Conversion of the failing ileoanal pouch to reservoir-ileostomy rather than to ileostomy alone.

PURPOSE: We report the indications, technique, and results of conversion of the ileoanal pouch to the Kock's pouch in five patients. The indication was functional disturbance that could not be corrected by operation. Aim of the conversion operation was re-establishment of fecal control and complete preservation of existing ileal surface. METHODS: The ileal pouch was used again, and in one case an augmentation was made. The continence valve was made three times from the afferent loop and in two cases from a higher ileal segment. RESULTS: Following conversion, function was excellent in three patients with ulcerative colitis and in one patient with familial adenomatous polyposis. One woman who underwent proctocolectomy for slow-transit constipation needed a Brooke ileostomy for continuous abdominal distention pain. CONCLUSION: We conclude that conversion to a continent ileostomy is a rewarding method of safely eliminating dysfunction of the ileoanal pouch that cannot be corrected by operation. Presumption is, however, that the surgeon is familiar with both methods and that the primary disease is suitable for pouch surgery.

Adenomatous Polyposis Coli↗
PubMed1996

[Temperature distribution pattern in liver tissue in freezing procedures with new cryoprobes].

The performance of new cryoprobes was studied by measuring the spatial and temporal patterns of the temperature distribution in liver tissue around one to three active cryoprobes. After 15 min of maximal freezing a tissue region 22 mm in diameter was frozen to temperatures below - 50 degrees C by one active cryoprobe. With three cryoprobes, using the synergistic cooling effect, a tissue region 45 mm in diameter was cooled to temperatures below - 50 degrees C. Optimal placement of the cryoprobes was found to be of critical importance.

Animals↗
PubMed1996

[Current proctology--modern functional diagnosis].

The large majority of pathological conditions in proctology can be recognized and distinguished from each other by clinical and endoscopic means of diagnosis. Manometric and neurophysiological investigations are especially useful for understanding pathophysiology; these methods are of great clinical value whenever their results contribute to a specific concept of therapy. Functional tests are able to distinguish among the various causes of sphincteric dysfunction. Defaecography might provide the decisive hint for operative treatment for manometric investigations of the ano-rectum, balloons, perfusion tubes and microtransducers are available. In cases of incontinence, especially in females, endosonography is the investigation of choice, providing most relevant information with regard to possible surgical reconstruction of the sphincter muscle.

Anal Canal↗
PubMed1996

[Elective lymph node dissection in malignant melanoma--status of color Doppler findings].

Since there is still a controversial discussion about the ELND in melanoma patients, the purpose of this prospective study was to optimize the indication concerning ELND by ultrasound examinations. 144 patients with primary melanomas were checked every 3 months after excision. Echomorphologic pattern and intranodal vascularisation in the color-flow Doppler modus provide essential information for differential diagnosis. We found 47 patients (32.6%) with suspicious ultrasound lesions. 50% of these patients had no pathological clinical findings, the histological findings of excised lymph nodes were positive in all cases. It must be emphasized, however, that the group with lymph node metastases included 12 patients with low-risk-melanomas (2 x Tis, 10 x T1 < 1 mm tumor thickness). In comparison with a historical control group (141 patients), where ELND was performed routinely in high-risk-patients ( > T2), the incidence of ELND in our hospital decreased more than 50%; at the same time the percentage of detected lymph node metastases increased (twice).

Adult↗
PubMed1996

[Surgical treatment concept in traumatic sphincter lesions].

The surgical problems of traumatic sphincter lesions are reported comparing early and late repair. In 11 acute injuries the surgical concept consisted generally of proximal fecal deviation, distal washout, reconstruction of the muscular defects and presacral drainage. In soft tissue injuries (grade I, n = 2) complete healing without functional deficiencies was obtained inspite of renouncing fecal diversion. In isolated ruptures of the rectum or the sphincter (grade II, n = 3) and in complete disruption of both components (grade III, n = 4) after healing and closure of the temporary colostomy continence was estimated subjectively as being sufficient. Patients' overall-appraisal was not correlated to the preoperative degree of destruction not the postoperative measurement of continence. Only when devascularisation of the anorectum with severe bleeding had occurred (grade IV, n = 2) proctectomy was necessitated resulting in one death. In none of 5 patients operated on elsewhere there was a chance of secondary sphincteric reconstruction. During operation or endosonographically and electromyographically the sphincter musculature could not be detected. Obviously renouncing of anatomical reconstruction leads not only to retraction but also to secondary degeneration of the sphincter muscles.

Adolescent↗
PubMed1995

Comparative effects of secretin (SEC) and cholecystokinin-octapeptide (CCK-8) on pancreatic microcirculation.

Using epifluorescent microscopy, we investigated the dynamic changes in pancreatic microcirculation in vivo after bolus administration of secretin (SEC) (0.1-10.0 micrograms/100 g body wt) and cholecystokinin-octapeptide (CCK-8) (0.005-1.2 micrograms/100 g body wt) in pentobarbital-anesthetized rats. Pancreatic capillary red cell velocity as a monitor for pancreatic capillary blood flow was measured in 1-min intervals from 2 min prior to 8 min following bolus infusion of SEC or CCK-8. Physiological concentrations of SEC did not increase pancreatic capillary blood flow. However, pharmacological SEC concentrations induced a dose-dependent increase in pancreatic capillary blood flow (to 162 +/- 19% of baseline; P < 0.05), due to an increase in blood flow velocity (to 153 +/- 18% of baseline; P < 0.05). In contrast, bolus administration of physiological CCK-8 concentrations, which have been proven to stimulate enzyme secretion, induced a transient and dose-dependent increase in pancreatic capillary blood flow (to 235 +/- 24% of baseline; P < 0.05), due to an increase in blood flow velocity (to 184 +/- 13% of baseline; P < 0.05) and capillary diameters (+0.63 +/- 0.15 micron; P < 0.05).

Analysis of Variance↗
PubMed1995

[Apnoeic oxygenation in Boerhaave syndrome].

UNLABELLED: Boerhaave's syndrome (Hermann Boerhaave, 1724 [5]) stands for the atraumatic spontaneous rupture of the oesophagus, and still represents a life-threatening situation. Contrary to the surgical approach, the anaesthesiological management has been largely neglected so far. CASE REPORT: The present case report introduces a patient requiring surgical therapy due to a belatedly diagnosed rupture of the oesophagus. In agreement with the surgeon, endotracheal intubation was performed using a single-lumen oral Woodbridge tube. During left thoracotomy, artificial ventilation sometimes obstructed the surgeons. Following a life-threatening intrathoracic venous bleeding (after additional right thoracotomy), the situation became almost adverse, since the surgeon could not stop the bleeding due to the movement of the lungs. Ventilation was therefore stopped. The oxygen supply was provided 20 min by application of the so-called apnoeic oxygenation, first described in 1908 by the German surgeon Franz Volhard (15). Using the filled 2.5l reservoir bag of the circle circuit as the oxygen source (CPAP 10 cm H2O), oxygenation was maintained by refilling the bag after its volume had been decreased due to the patient's ongoing O2 consumption. Starting with an initial paO2 value of only 400mmHg (despite pAO2 approximately 670 mmHg, i.e. intrapulmonary right-left shunt of approx. 10-15%), the paO2 declined to 100 mmHg during the 20 min of apnoeic oxygenation (i.e. a drop by 15 mmHg per minute), whereas arterial pCO2 increased by 50 mmHg to a value of 90 mmHg, as stated recently in literature [18]). No relevant changes of ECG, heart rate, blood pressure and partial arterial oxygen saturation (pulse oxymeter) occurred. CONCLUSION: During thoracic operations adverse situations may arise from the two antipodes artificial ventilation and acceptable surgical access. Alternative respiratory techniques, e.g. one-lung anaesthesia and/or high-frequency jet ventilation, are not always applicable, although the present case report indicates that a double lumen tube should be recommended. However, the clinical use of oxygenation by apnoeic oxygenation is a useful measure that can be realised in a simple and safe manner. The present case report may help to consider this particular alternative also during thoracic surgery (no influence of FRC size on pAO2 decrease). If applied correctly, apnoeic oxygenation obviously increases both the flexibility of the anaesthesist and patient safety, and additionally provides the ability of safe acting in clinical routine settings as well as during emergencies. In summary, knowledge of this technique of oxygenation seems to be an integral part of serious anaesthesiological education and clinical management.

Esophageal Diseases↗