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Biomedical subjects

K H Fuchs

Publications and source records attributed to K H Fuchs.

At least 37 records · Page 2Linked to original sources
PubMed2000

Comparison of anastomotic microcirculation in coloanal J-pouches versus straight and side-to-end coloanal reconstruction: an experimental study in the pig.

Several studies have shown a lower rate of anastomotic leakages in patients with coloanal J-pouch reconstruction than in those with straight coloanal anastomosis following anterior resection of the rectum. This study investigated whether this difference is due to a better anastomotic microcirculation. Thirty-two healthy, adult Göttinger mini-pigs underwent anterior rectal resection. They were subsequently randomized to following four groups (eight pigs per group): straight end-to-end, side-to-end, small pouch (4 cm), and large pouch (8 cm) coloanal anastomosis. Bowel perfusion was measured before and after vessel ligature at predefined locations using laser Doppler flowmetry. After completion of the anastomosis microcirculation was investigated 1 cm above, below, and directly at the anastomotic site. Following vessel ligature there was a 25% drop in blood flow. After completion of the anastomosis there was a further decrease of 25% in the distal segment, while no changes were observed above the anastomosis. There were no statistical differences either before or after completion of the anastomosis between the various groups. It is concluded that anastomotic blood flow does not depend on the type of coloanal reconstruction in healthy pigs.

Anastomosis, Surgical↗
PubMed2000

Laparoscopic fundoplication--short- and long-term outcome.

Gastroesophageal reflux disease is probably the most frequently occurring benign functional disorder in the Western industrial countries. With the increasing popularity of laparoscopic anti-reflux procedures, issues on the appropriate technique have been revitalized. The purpose of this study is to evaluate the short- and long-term outcomes of laparoscopic fundoplication and reflect on the perspective of an increasing frequency of performed operations. The data sampling is based on a literature review and a questionnaire. It can be summarized that reflux recurrence due to breakdown of the wrap or herniation of the wrap can also develop in later years after the primary surgery and amount up to 8%. Persistent dysphagia is a severe problem in the first post-operative year, but usually decreases with time and is limited to rates of 3-5% on the long-term follow-up. Other functional problems, such as gasbloat, meteorism and epigastric pain--the cause often cannot be further detected or specified--limit the quality of life of patients after laparoscopic anti-reflux surgery in the long-term follow-up in up to 5% of cases. Side effects of laparoscopic antireflux procedures can be limited to 5 to 10%, but not totally avoided.

Chronic Disease↗
PubMed2000

Evaluation of the intestinal microflora in the rat model for esophageal adenocarcinoma.

Surgically induced duodenal reflux results in cancer development in the rat esophagus. One proposed mechanism of carcinogenesis relies on the production of carcinogens in the presence of bacterial overgrowth. Against this background, intestinal microflora in the rat jejunum was analyzed before and after reflux-inducing surgery. Total gastrectomy and esophagojejunostomy were performed on Sprague-Dawley rats to produce esophageal reflux of duodenal juice (n = 12). Three days before surgery they were randomized into three groups: animals which received tap water; animals which received acidified water at pH 1.8; and animals subjected to oral decontamination with triple antibiotics. During surgery and at autopsy after 2 weeks, intestinal juice was aspirated and analyzed immediately for bacterial content. The physiologic microflora of the rat jejunum contained Lactobacillus spp. and Bacteroides spp., both of which were resistant to the antibiotic regimen. Bacterial overgrowth with fecal bacteria was found following surgery. Acidified water did not alter the intestinal microflora. Triple antibiotics eliminated Escherichia coli and Proteus spp. and reduced the concentration of Enterococcus spp. Bacterial overgrowth by bacteria of the fecal flora occurs in the rat model of esophageal adenocarcinoma with the potential to catalyze the production of carcinogens.

Adenocarcinoma↗
PubMed2000

Experimental evaluation of the safety and biocompatibility of a new antireflux prosthesis.

Previous studies have shown that encircling of the esophagogastric junction by a semiabsorbable scarf effectively prevents gastroesophageal reflux. The present study was performed to assess the long-term safety and biocompatibility of this type of scarf. The semiabsorbable scarf was implanted into 20 dogs either laparoscopically or via laparotomy. Pre- and post-operatively, contrast radiography, esophageal manometry, and upper gastrointestinal endoscopy were performed. No cases of perforation, stricture formation or other adverse effects were found after 1 and 2 years. It is concluded that the new type of scarf is without any adverse side-effects. Functional evaluation in reflux patients appears to be warranted.

Animals↗
PubMed2000

Duodenogastric reflux and foregut carcinogenesis: analysis of duodenal juice in a rodent model of cancer.

The incidence of esophageal adenocarcinoma is increasing rapidly. In rats, surgically induced duodenoesophageal reflux is carcinogenic. One proposed mechanism of carcinogenesis is based on the reaction of physiological bile acids with nitrite to produce carcinogenic N:-nitroso amides. To test this hypothesis, duodenal juice was analyzed for endogenously formed N:-nitroso bile acids and its genotoxicity was determined. Esophagojejunostomy was performed on 15 Sprague-Dawley rats to produce duodeno-esophageal reflux. At the time of surgery and 2 and 6 weeks later, duodenal contents were aspirated and analyzed immediately. High performance liquid chromatography coupled to tandem mass spectrometry was used to detect bile acids and their nitroso derivates. Genotoxicity was assessed using a micronucleus test. The characteristic pattern of bile acid derivatives, with taurocholic acid (TCA) and glycocholic acid (GCA) as the predominant conjugates, was detected in all samples. However, even selective reaction monitoring experiments failed to demonstrate the presence of any N:-nitroso-TCA or N:-nitroso-GCA. In addition, other nitroso derivatives could not be detected in any of the samples by neutral loss experiments monitoring the loss of nitric oxide (detection limit 0.1% of the concentration of TCA). All samples were cytotoxic, but neither the preoperative nor the postoperative samples were genotoxic. Duodenal juice was cytotoxic but not genotoxic. Tumorigenesis of esophageal adenocarcinoma in the rodent model could not be linked to a specific carcinogen, especially not to nitroso bile acids. Chronic inflammation is likely to be the mechanism of carcinogenesis by duodenogastric reflux.

Adenocarcinoma↗
PubMed2000

Sonography for selecting candidates for laparoscopic cholecystectomy: a prospective study.

OBJECTIVE: We assessed the value of sonography in predicting intraoperative difficulties for patients undergoing laparoscopic cholecystectomy and in identifying indicators for conversion to conventional cholecystectomy. SUBJECTS AND METHODS: Upper abdominal sonography was performed (according to a checklist) in 75 consecutive patients before laparoscopic cholecystectomy. Sonographic findings were verified by the surgeon in the operating room. RESULTS: Conversion from laparoscopic surgery to laparotomy was performed in five patients (6.7%). Of 75 patients, 19 had sonograms revealing gallbladder wall thickening (>4 mm); surgical preparation difficulties in 16 of these patients led to laparotomy in four patients. Sensitivity, specificity, positive predictive value, and accuracy of wall thickening as an indicator of technical difficulties were 66.7%, 94.1%, 84.2%, and 85.3%, respectively. Sensitivity, specificity, positive predictive value, and accuracy of wall thickening as an indicator of surgical conversion were 80.0%, 78.6%, 21.1%, and 78.7%, respectively. Technical difficulties at laparoscopy occurred in all five patients with pericholecystic fluid on sonography (sensitivity, 20.8%; specificity, 100%; positive predictive value, 100%; accuracy, 74.7%) and led to laparotomy in three patients (sensitivity 60.0%, specificity 97.1%, positive predictive value 60%, accuracy 94.7%). The accuracy of sonography for cholecystolithiasis was 100%. CONCLUSION: On sonography, gallbladder wall thickening is the most sensitive indicator and pericholecystic fluid is the most specific indicator of technical difficulties during laparoscopic cholecystectomy. Such difficulties may require conversion to laparotomy.

Abdomen↗
PubMed2000

[Epidemiology and pathophysiology of Barrett esophagus].

The pathophysiology of Barrett's esophagus appears to be a sequential process; the squamous epithelium of the esophagus is replaced by multipotent undifferentiated cells; secondary to cellular damage in the course of gastroesophageal reflux disease these undifferentiated cells further differentiate under the ongoing influence of mucosal damage, thus forming the typical morphology of Barrett mucosa. While the prevalence of gastroesophageal reflux disease amounts to 10% to 30%, the prevalence of Barrett's esophagus is estimated to be 1% in the general population. The epidemiologic data of Barrett's esophagus gain special attention with regard to the fact that the specialized columnar epithelium with intestinal metaplasia represents the only recognized risk factor for the development of adenocarcinoma in the esophagus. Currently it is estimated that the risk of the development of an adenocarcinoma on the basis of Barrett's esophagus is about 30-50 fold higher than that in the general population.

Adenocarcinoma↗
PubMed2000

[Surgical treatment of Barrett carcinoma].

Barrett-carcinoma is a type of adenocarcinoma of the distal esophagus and the cardia. Barrett-esophagus is defined by the histologic presence of specialized epithelium with intestinal metaplasia. As a consequence Barrett-carcinoma has a close relationship to the adenocarcinoma of the cardia and is very often part of the cardiacarcinoma type I. The aim of the surgical therapy is a radical R0-resection of the tumor including the lymphatic drainage area. This aim is accomplished among different authors by different surgical concepts. One is the radical transhiatal subtotal esophagectomy with lymphadenectomy in the lower mediastinum and the upper abdominal compartments. The other concept is a transthoracic en-bloc esophagectomy. Both resection procedures are usually completed by gastric pull up reconstruction. Currently a sophisticated preoperative staging is followed by distinguished indication and therapy depending on tumor status, risk factors of the patient and on the international classification of the cardia carcinoma (Siewert). When a R0-resection is impossible, a neoadjuvant radiochemotherapy should be performed.

Adenocarcinoma↗
PubMed1999

Comparison of different J-pouches vs. straight and side-to-end coloanal anastomoses: experimental study in pigs.

PURPOSE: Functional results after low anterior resection with straight coloanal anastomosis are poor. Although certain functional aspects are improved with coloanal J-pouch anastomosis, evacuation difficulties are encountered in some of these patients. The aim of the study was to investigate the functional results of different reconstruction methods after low anterior resection in a standardized pig model. METHODS: Thirty-two adult Göttinger mini pigs were randomly assigned either to straight end-to-end (Group 1), side-to-end (Group 2), small (4-cm limb length) J-pouch (Group 3), or large (8-cm limb length) J-pouch (Group 4) coloanal anastomosis after low rectal excision. The animals were investigated 12 weeks after the operation by measuring neorectal compliance and ceruletide-induced defecation. Eight pigs without operation were used as controls (Group 5). RESULTS: Compliance was lowest in Groups 1 and 2, which were significantly different compared with both pouch designs and controls. Neorectal compliance of pigs with either small or large pouches did not differ significantly compared with one another or controls. Defecation was significantly impaired in pigs with a large pouch compared with all other groups. Pigs with side-to-end anastomoses had as rapid an evacuation as animals with straight coloanal reconstruction. CONCLUSION: Coloanal J-pouch reconstruction adequately restores reservoir capacity after low anterior resection of the rectum. From a functional point of view, side-to-end is not superior to straight coloanal anastomosis. Compared with small pouches, a large pouch design does not lead to better neorectal compliance in the pig model, whereas pouch evacuation seems to be considerably compromised.

Anal Canal↗
PubMed1999

Perforating appendicitis: is it a separate disease? Acute Abdominal Pain Study Group.

OBJECTIVE: To find out whether perforated and unperforated appendicitis are separate diseases and can be distinguished clinically. DESIGN: Prospective multicentre study. SETTING: 11 departments of surgery in Germany and Austria. SUBJECTS: 519 patients over 6 years old who had histologically confirmed acute appendicitis between October 1994 and March 1996. MAIN OUTCOME MEASURES: Differences in history, clinical findings, lab results, clinical course and outcome. RESULTS: 92 of the 519 patients (18%) had perforated appendicitis. The following variables were shown by univariate analysis to be significantly more common in the group with perforated appendicitis: rigidity, reduced abdominal wall movement, abdominal distension, reduced bowel sounds (all p<0.001), pale skin (p<0.005), generalised abdominal tenderness, severe abdominal tenderness (both p<0.01), WCC > or =10(9)/L (p<0.05). By multivariate analysis the following variables were significantly more common in the group with perforated appendicitis: age over 50 years (p<0.0001); change in bowel habit and rigidity of the abdominal wall (both p = 0.001); generalised tenderness (p<0.01); male sex (p<0.01); and distended abdomen (p<0.05). Rectal examination failed to make the distinction. CONCLUSIONS: Perforated and unperforated appendicitis behave clinically like two different diseases. They can in most cases reliably be distinguished using clinical criteria alone. Although greater diagnostic accuracy may result in a higher rate of perforation, close observation and timely intervention will only marginally affect the outcome.

Adult↗
PubMed1999

Duodenogastric reflux of bile in health: the normal range.

Duodenogastric reflux (DGR) is suspected to be an aetiological factor in the pathogenesis of foregut disease. The 'Bilitec' bile probe allows continuous detection of bilirubin, based on spectrophotochemical properties. We aimed to describe duodenogastric bile reflux in healthy, normal volunteers in a Western European population, as a basis for the future study of DGR in disease. An international multicentre study was established. DGR was measured using 24 h ambulatory bile and pH monitoring in the proximal stomach, in 43 normal volunteers from the third to the seventh decades. Subjects adhered to a standard protocol. The total test period, supine and upright components, were analysed. The 90th percentile values for absorbance thresholds of 0.14, 0.25, 0.3, 0.4 and 0.5 were 40.5%, 20.9%, 19.6%, 11.6% and 4.6% of the total time respectively. There was a wide range of absorbance within each threshold. Supine DGR was greater than upright, and associated with an alkaline tide. The upright phase was further subdivided into upright fasting, prandial and post prandial phases, and ranges for these periods are also described. No relationship between age, weight, or body mass index and duodenogastric reflux was seen. The results of this study form a range which allows further investigation into the contribution of duodenogastric bile reflux in the pathogenesis of foregut disease.

Adult↗
PubMed1999

Long-term results after 75 anastomoses in the upper extraperitoneal rectum with the biofragmentable anastomosis ring.

BACKGROUND: Anastomoses in the rectum have a higher risk for complications compared with other gastrointestinal regions. Stapling devices and sophisticated developments in surgical suture materials did not lead to a substantial decrease of local complications. The bioabsorbable anastomosis ring (BAR) is a new alternative technique for creating gastrointestinal anastomoses. Accordingly, the aim of this prospective study was to evaluate the postoperative course and long-term results of patients after anterior rectum resection using BAR. METHODS: From 1991 to 1996 75 BAR anastomoses were performed in the upper rectum at the Department of Surgery, University Hospital Würzburg. Thirty-eight patients suffered from malignant, 37 from benign disease. Mean age was 61.4 years with no relevant differences in the gender. Mean follow-up was 31 months (4-63 months). The clinical course was evaluated, a questionnaire completed and/or a 3-monthly reevaluation with endoscopy conducted. Mortality, anastomostic bleeding, leakage and development of anastomotic stenosis were evaluated. RESULTS: Sixty-seven patients could be reexamined. There was no postoperative mortality and no anastomotic bleeding. Six patients (8%) developed an anastomotic leakage, of whom 3 (4%) required reoperation. None of the patients revealed a detectable stenosis in the anastomotic region during follow-up. CONCLUSION: The BAR procedure is a safe and suitable anastomotic technique after anterior rectum resection.

Absorbable Implants↗
PubMed1999

[Functional diagnosis of pelvic floor insufficiency--consequences for surgery].

Functional tests allow for the qualification and quantification of underlying function defects in the diagnosis of pelvic floor incompetence. However, the results of these instrumental investigations alone do not suffice for a therapeutic decision. The decision for a surgical therapy should therefore always be based on the clinical presentation, the extent of subjective impairment, and the degree of the causative pathophysiologic defect detected in the function tests.

Fecal Incontinence↗
PubMed1999

[Endosonographic imaging of anal fistulas in infants].

Anorectal endosonography is established as a diagnostic tool in anorectal fistulas, today. Yet, there is still little experience with the use of this method in small children. We could visualize three intershincteric fistulas in children at an age of 6, 7 and 14 months. The procedure is well tolerated and even children under the age of one year can be examined with a special probe.

Contrast Media↗
PubMed1999

[Open surgical therapy of constipation].

This paper reviews diagnostic criteria, indications, and selection criteria for surgical therapy in chronic constipation. Special emphasis is laid on surgical therapy of pelvic outlet obstruction. Colonic resection may be considered as last surgical resort in those few cases where conventional therapeutic measures have been exhausted and an extensive diagnostic protocol based on clearly defined criteria has been followed. This may offer a justifiable therapeutic alternative only in cases where highly symptomatic and refractory colonic inertia (slow transit constipation) is confirmed, and associated outlet obstruction has been excluded.

Chronic Disease↗
PubMed1998

An atomic model of crystalline actin tubes: combining electron microscopy with X-ray crystallography.

The packing of the G-actin monomers within crystalline actin tubes was investigated at atomic detail. To achieve this, we have chosen an integrated structural approach which combines intermediate resolution electron microscopy based 3-D reconstruction and surface metal shadowing of crystalline actin tubes with atomic resolution X-ray data of the G-actin monomer. Distinct from the parallel, half-staggered packing of the actin subunits within F-actin filaments, the arrangement of actin monomers within the crystalline tubes involves antiparallel packing into dimers with p2 symmetry. Within the crystalline tubes, the actin monomers are oriented so that the filament axis runs parallel with the sheet plane and the intersubunit contacts in this direction are similar to those existing along the two long-pitch helical strands of the F-actin filament. The other intersubunit contacts within the crystalline tubes are not found in the actin filament. The ability of actin to form a variety of polymorphic oligomers is still not fully understood, and the functional implications of this variability have yet to be deciphered. Regularly packed actin assemblies such as sheets, tubes or ribbons may ultimately yield structural relationships to in vivo relevant actin oligomers such as, for example, the "lower dimer".

Actins↗