Biomedical subjects

C Töns

Publications and source records attributed to C Töns.

At least 19 recordsLinked to original sources

PubMed2002

Intra-abdominal pressure: a reliable criterion for laparostomy closure?

BACKGROUND: Laparostomy is frequently performed in the surgical therapy of mechanical obstruction, peritonitis, or trauma to prevent abdominal compartment syndrome (ACS). Extended incisional hernia is inevitable when fascial closure is missed (up to 90% of cases). Intra-abdominal pressure (IAP) has not yet been evaluated as a criterion for the feasibility of fascial closure. PATIENTS AND METHODS: Over 12 months laparostomy was carried out in 40 patients. Definitive closure of the abdomen was performed after 4.4+/-3.7 days in 23 of these. Intravesical pressure was used to assess IAP before and after fascial closure. The resulting IAP was compared to the values of 90 patients undergoing elective abdominal surgery. Parameters of cardiocirculatory, renal, pulmonary, and liver function were also recorded. RESULTS: After closure of the laparostomy IAP increased significantly from 6.5+/-3.3 to 12.0+/-4.1 mmHg. Urine output decreased by 27% on the first postoperative day but regained normal levels thereafter. The central venous pressure increased by 31%. Other parameters of cardiocirculatory, renal, pulmonary, and liver function were unchanged. No case of ACS occurred. In the patients undergoing elective abdominal surgery IAP ranged from 6.5+/-2.1 to 10.0+/-4.0 mmHg. CONCLUSIONS: Fascial closure increased the IAP, which was accompanied by short-termed decrease in urine output. At these levels of IAP fascial closure appears to be harmless, but further prospective studies are needed to determine the critical level of IAP for allowing a safe repair of large fascial defects.

Abdominal Cavity↗

PubMed2002

[Weakly malignant leiomyosarcoma of the inferior vena cava. A case report].

Primary vascular leiomyosarcomas of the great vessels are rare and the most common localization is the inferior vena cava. Due to nonspecific clinical signs, diagnosis is often made during operation or autopsy. At present, a radical tumor resection is the first choice of treatment. This is a case report of a 49-year-old woman who suffered from abdominal pain for 10 years because of a weakly malignant leiomyosarcoma of the inferior vena cava. A radical tumor resection and reconstruction with a prosthetic vascular graft were performed. Diagnosis, therapy, and prognosis are discussed.

Blood Vessel Prosthesis Implantation↗

PubMed2002

Quantitative evaluation of abdominal wall perfusion after different types of laparotomy closure using laser-fluorescence videography.

Laparotomy closure relies on the incisional edges as anchor for the suture material. The results of these techniques are not satisfying, with failure rates of up to 20%. To investigate the effect of different conventional closure techniques and a novel "bridging technique" on abdominal wall perfusion an animal study was performed in rabbits. Abdominal wall perfusion was measured using the method of dynamic laser-fluorescence videography in the first 72 h of incisional wound healing in 25 animals. Suture tension was controlled with a water-filled polyurethane balloon connected to a pressure detector. The effect of laparotomy closure on abdominal wall tissue perfusion depends significantly on the applied technique and suture tension. Avoiding direct sutures in the incisional edges during laparotomy closure leads to a better tissue perfusion of the incisional region than conventional suture techniques. Suture tension can be controlled and adjusted using a water-filled polyurethane balloon as a pressure sensor.

Abdominal Wall↗

PubMed2001

Influence of suture technique on laparotomy wound healing: an experimental study in the rat.

A suture length to wound length ratio (SLWL ratio) of 4:1 for laparotomy closure has proven in clinical studies to reduce incisional hernia incidence. The effect of different SLWL ratios on the mechanical qualities of the healing incision has not been examined experimentally. In 50 rats, the musculo-fascial layer of median laparotomies was closed with polypropylene sutures using SLWL ratios of 8:1, 4:1, 2:1 and 1.7:1. Single and running sutures, different tissue bites and different suture tensions were applied. Five rats served as controls. After 14 days, the horizontal strength of the incision was tested in a digitised tensiometer. The SLWL ratio, suture tension and suture technique proved to have significant influences on the mechanical strength of the incision. Running sutures and especially closures with a ratio of between 4:1 and 8:1 proved significantly stronger than wounds closed with single sutures. When small tissue bites were applied, the positive influence of running sutures was equalised in the early phase of wound healing. High suture tension led to significantly weaker scars independent of the applied suture technique. In accordance with clinical data, it could be proven experimentally that running closure of midline laparotomies with a SLWL ratio above 4:1 avoiding high suture tension exerts a significantly positive effect on the mechanical strength of the incision. Further studies are needed to allow measurement and better control of suture tension.

Animals↗

PubMed2000

[Large flank tumor after covered gallbladder perforation].

We report on a 79-year-old woman patient with a tumor with a diameter of 18 cm in the right flank. The medical history of the patient was normal except for a single asymptomatic gallstone, which had been known since 12 years. Sonography and abdominal CT showed an enormous intra-abdominal mass filled with liquid with a permanent union with the gallbladder. We than performed an explorative laparotomy with a tumor resection and a cholecystectomy. The histological examination showed perforation of the gallbladder with a great pseudocyst filled with 1800 ml infected bile and with penetration through the abdominal wall.

Aged↗

PubMed2000

[Abdominal compartment syndrome: prevention and treatment].

UNLABELLED: Abdominal compartment syndrome is defined by increased intraabdominal pressure above 20 mmHg with increased pulmonary peak pressure and oliguria. In primary abdominal compartment syndrome the increased intraabdominal pressure is caused directly by peritonitis, ileus or abdominal and pelvic trauma. Secondary compartment syndrome is a result of forced closure of the abdominal wall after abdominal surgery. The effects are decreased cardiac output, pulmonary atelectasis, oliguria to anuria and hepatic as well as intestinal reduction of perfusion. Effective monitoring is done by standardised measuring of urinary bladder pressure. Normal values are between 0 and 7 cm H2O, after elective laparotomies 5-12 cm H(2)0. Above 25 cm H(2)0 they are definitely pathological. For the prevention and therapy of manifested abdominal compartment syndrome the application of a laparostomy using a resorbable mesh is recommended. Between 1988 and 1999 we applied a laparostomy to lower the intraabdominal pressure in 377 patients. In 16% of the cases it was indicated by primary abdominal compartment syndrome with a bladder pressure of 31 +/- 4 cm H(2)0 preoperatively, which could be lowered to 17 +/- 4 cm H(2)0 by laparostomy. An early reconstruction of the abdominal wall could be performed in 18% of the cases. CONCLUSIONS: The abdominal compartment syndrome is an often underestimated problem in abdominal surgery involving multiple organ systems. The temporary laparostomy lowering intraabdominal pressure rather than a forced closure of the abdominal wall should be used in all circumstances.

Abdomen↗

PubMed2000

[Preserving autonomic nerves in rectal surgery. Results of surgical preparation on human cadavers with fixed pelvic sections].

INTRODUCTION: Preservation of sexual function and voiding capacity after rectal cancer surgery has increased after adopting the technique of nerve-sparing dissection and total mesorectal excision. Still the rate of sexual and urinary dysfunction ranges between 25 and 67%. The precise locations where nerve damage occurs have not been looked at systematically. MATERIAL AND METHODS: In ten human corpses and two formalin-fixed human pelvises the autonomous pelvic nerves were isolated. Their relation according to surgical mobilization of the rectum were photodocumented. RESULTS: Pelvic autonomous nerves are clearly defined structures with only minor interindividual variability. The inferior mesenteric plexus forms a dense network around the inferior mesenteric artery (AMI) to a distance of 5 cm from the aorta. The distance between the lateral rectum and the pelvic plexus is only 2-3 mm. The anterior rectum is almost directly adherent to the neurovascular bundle, separated only by Denonvillier's fascia. The parasympathetic branches of the sacral segments S2-S5 cannot be isolated using the standard surgical approach. CONCLUSION: (1) The nomenclature of fascias and the course of the autonomous pelvic nerves is not clearly defined in the literature; (2) a high tie of the AMI leads to damage of the sympathetic nerves; (3) the narrow space between the anterior and lateral rectum makes sharp dissection under direct vision necessary; (4) fascias and nerves can be used as guiding structures during mobilization; (5) a preservation of selected parasympathetic roots in the small pelvis is not feasible using the standard surgical approach.

Autonomic Nervous System↗

PubMed2000

Influence of suture material and suture technique on collagen fibril diameters in midline laparotomies.

BACKGROUND: Although laparotomy closure is associated with a cumulative 15% failure rate, the effect of different suture techniques and materials on the ultrastructural composition of the healing incision has not been investigated. METHOD: in 40 Wistar rats the collagen fibril diameters and the regenerative tissue were compared using electron microscopy 14 and 28 days after midline laparotomy. Wounds were closed with single and running sutures using either polypropylene or polyglactin 910. RESULTS: Closure with polypropylene led to significantly larger mean fibril diameters than closure with polyglactin. Regardless of time and suture material, running closure resulted in significantly smaller mean collagen fibril diameters than single sutures. Four weeks after laparotomy, inflammatory reactions, disorganization of collagen and irregularities of the vascular architecture were found after closure with absorbable suture material but not after closure with nonabsorbable material. CONCLUSION: Suture material and suture method significantly influence the ultrastructural composition of the healing incision. Persisting mechanical irritation around the suture threads after single sutures and severe persisting inflammatory reactions after the use of absorbable suture material are important influencing factors.

Animals↗

PubMed1998

[Perforated diverticulum of the vermiform appendix].

Diverticulitis of the vermiform appendix is an often disregarded disease. Diagnosis follows after appendectomy due to inflammatory complications in the form of diverticulitis and appendicitis. Diverticula can also be found as a reason for complaints in histologically unaltered appendix or as an incidental finding. Diverticula of the vermiform appendix are classified as false (acquired) or true (congenital). We report on the case of a 57-year-old man with a perforated appendix diverticulum as reason for peritonitis and a paralytic ileus of the colon and small intestine.

Appendectomy↗

PubMed1997

Induction of heat shock protein 70 (HSP70) by zinc bis (DL-hydrogen aspartate) reduces ischemic small-bowel tissue damage in rats.

The aim of the study was to determine whether the induction of HSP70 by Zn2+ is able to protect the small bowel of rats against ischemia. Twenty-four male Wistar rats (weight 200-300 g) were divided into four groups: (1) saline treatment for 24 h (n = 4); (2) Zn2+ treatment for 24 h (n = 4); (3) Saline pretreatment for 24 h and ischemia (n = 8); (4) Zn2+ pretreatment for 24 h and ischemia (n = 8). Pretreatment with Zn2+ was carried out by intraperitoneal administration of 50 mg/kg zinc bis (DL-hydrogen aspartate) = 10 mg/kg Zn2+. Ischemia in a defined segment of the small bowel was produced by ligation of the mesenteric vein and artery and ligation of both ends of the segment. Tissue samples were collected before and 2, 4 and 6 h after ligation and investigated by histology, immunohistochemistry and Western blotting. Twenty-four h after i.p. Zn2+ injection, the small bowel expressed increased HSP70 tissue levels. Histology with subsequent grading of ischemic tissue injury showed significantly decreased tissue necrosis after Zn2+ pretreatment and HSP70 induction compared with saline pretreated controls. In conclusion, this study proves that Zn2+ is inducing HSP70 in the small bowel in vivo and hereby able to protect the small bowel against ischemia.

Animals↗

PubMed1997

[Stage-oriented antibiotic therapy of peritonitis. Prospective study].

PATIENTS AND METHODS: In a prospective protocol 25 consecutive patients with diffuse peritonitis were treated in the Surgical Clinic of the RWT-University in Aachen, Germany, from January to December 1995. According to the "Mannheim Peritonitis Score" three different stages were treated with different surgical procedures and a selective antibiotic regimen. Group-A patients with prognostically favorable peritonitis (MPS 0-20) were treated with the so-called standard procedure, group-B patients (MPS: 21-29) with closed postoperative lavage. The antibiotic regimen was cefotaxime (2 x 2 g) and metronidazole (2 x 500 mg) for both group-A and group-B patients. Severe group-C cases (MPS > 29) were treated with the so-called Etappenlavage (multiple reexplorations and intra-operative lavage) and received a combination of three antibiotics (2 x 2 g cefotaxime; 2 x 500 mg metronidazole and 2 x 200 mg ofloxacin). RESULTS: Eight patients belonged to group A, 10 to group B, and 7 to group C. The mortality was 0% (group A), 20% (group B), and 29% (group C), respectively. The actual overall mortality of the whole group was 16% (4/25). The statistically expected mortality was 36%, according to the APACHE-II-Score (P = 0.0982).

Anti-Infective Agents↗

PubMed1997

Induction of heat shock protein 70 by zinc-bis-(DL-hydrogenaspartate) reduces cytokine liberation, apoptosis, and mortality rate in a rat model of LD100 endotoxemia.

A prospective, randomized model of LD100/24 h endotoxemia was performed in male Wistar rats (n = 26; 250-300 g). The animals were divided into four groups: Group I (n = 5; saline treatment only), Group II (n = 5; Zn2+ treatment only), Group III (n = 8; saline pretreatment, lipopolysaccharide (LPS) treatment), and Group IV (n = 8; Zn2+ pretreatment, LPS treatment). Zn2+ pretreatment was carried out by intraperitoneal injection of 50 mg/kg zinc-bis-(DL-hydrogenaspartate) (10 mg/kg Zn2+). LD100/24 h endotoxemia was induced by intraperitoneal administration of 20 mg/kg LPS of the Escherichia coli strain WO111:B4. Tumor necrosis factor alpha, interleukin-1 beta, and interleukin-6 were detected by enzyme-linked immunosorbent assay (ELISA). HSP70 expression in the lungs, the liver, and the kidneys was determined by immunohistochemistry, Western blotting, and an HSP70 ELISA. Apoptosis was also detected by an in situ apoptosis detection kit (TUNEL) and a cell death detection ELISA, respectively. This rat model of endotoxemia proves the close relationship between HSP70 expression, cytokine liberation, and development of apoptosis. The data demonstrate that: 1) Zn2+ is a potent inducer of HSP70 expression; 2) the application of Zn2+ leads to slightly increased cytokine plasma levels; and 3) the manipulation of the heat shock response by Zn2+ significantly increases the survival rate after LD100 endotoxemia. Enhanced survival rate in animals pretreated with Zn2+ may be explained by increased tissue levels of HSP70, a subsequent significantly decreased liberation of the proinflammatory cytokines after LPS challenge, and a significantly decreased rate of apoptosis.

Animals↗

PubMed1997

The influence of heat shock protein 70 induction on hemodynamic variables in a porcine model of recurrent endotoxemia.

The manipulation of stress gene expression by heavy metals provides protection against the lethal effects of endotoxemia in murine models of septic shock. These findings suggest that the increased resistance to endotoxin in vivo after stress protein induction could be explained by an attenuation of hemodynamic alterations and an altered pattern of inflammatory mediator release. Therefore, we measured main hemodynamic variables such as systemic and pulmonary artery pressure, cardiac output, heart rate, central venous pressure, and pulmonary artery wedge pressure, as well as the time-course of thromboxane-B2, 6-keto-PGF1 alpha, and interleukin 6 formation with and without induction of the stress response in an established porcine model of recurrent endotoxemia (Circ Shock 35:237-244, 1991). Induction of the stress response was carried out by a pretreatment with Zn2+ (25 mg/kg zinc-bis-(DL-hydrogenaspartate) = 5 mg/kg Zn2+). Pretreatment with Zn2+ prior to lipopolysaccharide (LPS) infusion induced an increased heat shock protein 70 (HSP70) expression in the lungs, liver, and kidneys and significantly increased plasma levels of interleukin 6, 6-keto-PGF1 alpha, and thromboxane-B2, compared with untreated controls. After LPS infusion, however, pretreated animals showed significantly decreased peak plasma levels of all mediators compared with the untreated group. Hemodynamic data presented significantly decreased peak pulmonary artery pressure and pulmonary vascular resistance index values, significantly increased systemic artery pressure and systemic vascular resistance index values, and significantly altered hypodynamic/hyperdynamic cardiac output levels in the pretreated group. In conclusion, the data show that the induction of HSP70 by Zn2+ attenuates the liberation of inflammatory mediators, as well as the course of hemodynamic variables due to LPS.

6-Ketoprostaglandin F1 alpha↗

PubMed1997

[Acute lung failure].

Ever-increasing knowledge of the pathomechanisms and the phasic pathogenesis of ARDS has increased the demand for adequate monitoring and has modified therapeutic strategies. The influence of monitoring by double indicator dilution technique (COLD system) with the close measurement of extravascular lung water on the diagnosis and therapy of ARDS is presented. Pressure-controlled ventilation (< 35 cm H2O) in combination with moderate PEEP, kinetic therapy (prone position) and elective CVVH already in the early stages of ARDS can be regarded as the standard therapy. The effectiveness of NO inhalation, prostaglandins and radical scavengers still has to be improved in controlled clinical trials.

Critical Care↗

PubMed1996

Influence of heat shock protein 70 and metallothionein induction by zinc-bis-(DL-hydrogenaspartate) on the release of inflammatory mediators in a porcine model of recurrent endotoxemia.

The manipulation of stress gene expression by heavy metals provides protection against the lethal effects of endotoxemia in murine models of septic shock. Recent in vitro studies with alveolar macrophages or monocytes show that induction of the stress response in these cells is followed by a decreased liberation of major cytokines [tumor necrosis factor-alpha (TNF alpha) and interleukin-1 (IL-1)] after endotoxin challenge. These findings suggest that the increased resistance to endotoxin in vivo after stress protein induction could be explained by an altered pattern of inflammatory mediator release. Therefore, we measured the time course of thromboxane-B2 (TxB2), 6-keto-PGF1 alpha, platelet activating factor (PAF), TNF alpha, interleukin-1 beta (IL-1 beta), and interleukin-6 (IL-6) formation with and without induction of the stress response in an established porcine model of recurrent endotoxemia (Klosterhalfen et al., Biochem Pharmacol 43: 2103-2109, 1992). Induction of the stress response was done by a pretreatment with Zn2+ (25 mg/kg zinc-bis-(DL-hydrogenasparate = 5 mg/kg Zn2+). Pretreatment with Zn2+ prior to lipopolysaccharide (LPS) infusion induced an increased heat shock protein 70 and metallothionein expression in the lungs, liver, and kidneys and increased plasma levels of TNF alpha, IL-1 beta, IL-6, and TxB2 as opposed to untreated controls. After LPS infusion, however, pretreated animals showed significantly decreased peak plasma levels of all mediators as opposed to the untreated group. The time course of mediator release was identical with the decreasing and increasing three peak profiles described previously. Hemodynamic data presented significantly decreased peak pulmonary artery pressures and significantly altered hypodynamic/hyperdynamic cardiac output levels in the pretreated group. In conclusion, the data show that the induction of stress proteins by Zn2+ could be a practicable strategy to prevent sepsis.

6-Ketoprostaglandin F1 alpha↗

PubMed1996

[Monitoring critically ill intensive care patients by semi-invasive COLD (Cardiac-Output-Liver-Diseases) monitoring instead of pulmonary artery catheterization].

The routine application of an arterial thermal-dye-dilution technique (so called COLD-Monitoring) offers new perspectives in the hemodynamic management of critically ill patients using a small invasive technique. COLD-Monitoring employs a computerized analysis of a double-indicator (temperature and dye) dilution technique which requires only a central venous catheter and a special fibre optic catheter with a temperature probe applied to the femoral artery. Especially in critically ill patients with septic course or multiple organ failure (MOF) COLD-monitoring serves to exactly measure volume and therefore distribution, to objectify capillary leakage by extravascular lung water index, to check the excretoric liver-function by plasma-deviation-rate of ICG and to perform a well controlled epinephrine therapy by measuring cardiac function index and systemic vascular resistance index.

Cardiac Catheterization↗

PubMed1995

Diagnostic imaging of mesenteric infarction.

PURPOSE: To determine the value of diagnostic imaging in the management of mesenteric infarction. MATERIALS AND METHODS: Within 8 years, 54 patients with mesenteric infarction underwent diagnostic imaging before surgery, including plain radiography (n = 45), ultrasound (US) (n = 29), small bowel follow-through examination (n = 7), colon enema study (n = 7), angiography (n = 16), and computed tomography (CT) (n = 22). Clinical course, laboratory values, and imaging findings were considered in diagnosis. RESULTS: Radiography and US allowed correct diagnoses in five of 18 cases (28%). Only one of 14 fluoroscopic examinations contributed to diagnosis. Fourteen of 16 angiography studies (sensitivity, 87.5%) and 18 of 22 CT examinations (82%) were correct. The difference in sensitivity between CT and angiography was not significant (P > .05). CONCLUSION: CT and angiography are highly sensitive, but CT can also be used to rule out other causes of acute abdomen. Careful evaluation of patient history and clinical situation should lead to suspicion of mesenteric ischemia and early indication for CT.

Aged↗

PubMed1993

[Septic shock and multiple organ failure in surgical intensive care. An animal experiment model on the analysis of pulmonary and intestinal dysfunction].

The study deals with an animal model for the problems of surgical intensive care patients. Following repeated applications of E. coli endotoxin WO 111:B4 under standard conditions, specific hemodynamic and biochemical (TNF, TXA2, PGI2, IL-6, PAF) and morphological (endothelium of the lung) alterations were detected. ARDS patterns induced by the sepsis were analyzed by high-frequency measurement of pressure and flow (385 measurements per breathing cycle). The role of the intestine in sepsis was investigated by ion-selective monitoring of surface potassium activity comparing mucosa and serosa. Every injection of endotoxin was followed by a selective increase of the potassium activity revealing relative ischemia induced by the endotoxin. The profile of the potassium levels on the surface correlates both with the cardiac output and with the prostacyclin levels. The continuous narrowing of the difference between mucosa and serosa, potassium during the period of investigation can be regarded as evidence for pathologic change in permeability fostering the septic course.

6-Ketoprostaglandin F1 alpha↗