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Biomedical subjects

N Senninger

Publications and source records attributed to N Senninger.

At least 109 records · Page 6Linked to original sources
PubMed1996

First clinical realization of continuous monitoring of liver microcirculation after transplantation by thermodiffusion.

To date, no method is available for the continuous long-term monitoring of liver microcirculation in patients. Experimentally, thermodiffusion has been validated in the quantification of hepatic perfusion. In an attempt to investigate the practicability of thermodiffusion technology in patients after liver transplantation thermodiffusion probes were inserted into the graft in seven patients during liver transplantation. Continuous monitoring started intraoperatively and was performed until day 7, when the probes were extracted transcutaneously. No probe-related complications (i.e., hemorrhage, infection) were observed. In four patients with normal graft function, liver perfusion recovered within 12 h from the intraoperative reduction to a range between 85 and 93 ml/100 g per min. In contrast, primary graft failure (n = 1) was characterized by a constant decrease of hepatic perfusion (< 50 ml/100 g per min). In prolonged reperfusion injury (n = 1), a second peak of transaminases was paralleled by an impairment of liver microcirculation. In one patient, R2 rejection on day 7 was preceded by a drop in hepatic perfusion 48 h earlier. Thus, thermodiffusion is a safe and reliable method for the continuous quantification of liver microcirculation after transplantation in patients. Measurements are reproducible for at least 7 days. Changes in hepatic perfusion during postoperative complications can be detected. The characteristics of microcirculatory disorders will have to be defined in a larger number of patients.

Adolescent↗
PubMed1996

[Hydrosonography of the pancreas. Initial results of a pilot study].

PURPOSE: To evaluate a new ultrasonographic imaging technique of the pancreas (hydrosonography), based on a combination of chemical intestinal paralysis and water distension of the stomach and duodenum, regarding its significance for tumor detection, staging and assessment of tumor resectability. MATERIAL AND METHODS: In an open prospective study 51 patients with suspected pancreatic neoplasm were examined between July 1995 and October 1995. The technique of hydrosonography included intravenous injection of 40 mg N-butyl-scopolaminiumbromid (Buscopan) and maximum gastric and duodenal wall distension by oral administration of an average of 11 warm tap water (0.5-1.51). A detailed evaluation form was used to assess (1) overall imaging quality; (2) accuracy of identification of the pancreas in its various anatomic regions and of peripancreatic vessel structures relevant for resectability, such as splenic, superior mesenteric, and portal veins, celiac trunk, and superior mesenteric, splenic and hepatic arteries; and (3) tumor size, sonographic structure and level of organ and vessel infiltration. As gold standards for positive tumor detection and description, surgery and microscopic diagnosis were used, and for negative tumor detection, event-free survival of 6 months. RESULTS: All examinations were diagnostic. Identification of the pancreas was complete in all 51 patients with an excellent overall imaging quality in 53%. In 86% of cases the various examined organ and vessel structures were depicted with either good or average imaging quality. In 48 of the 51 patients diagnosis positive for tumor or other organ pathology was made. A total of 16 pancreatic carcinomas and 5 benign tumors were diagnosed. Twenty-seven patients had pathology not related to a pancreatic neoplasm. For tumor detection, sensitivity was 82% and specificity 100%. For correct assessment of tumor resectability, sensitivity was 86% and specificity 100%. CONCLUSION: The new technique of hydrosonography combines the value of routine non-invasive abdominal ultrasound with increased sensitivity and specificity for tumor detection and assessment of resectability by improved imaging accuracy.

Adult↗
PubMed1996

[Hydrospiral CT of the pancreas in thin section technique].

PURPOSE: To evaluate a new technique for imaging the pancreas (spiral hydro-CT) based on a combination of pharmacological intestinal paralysis and water distension of the stomach and duodenum with specific reference to tumor detection rate, differentiation of malignant versus benign tumors, differential diagnosis and assessment of tumor resectability. MATERIAL AND METHODS: In an open prospective study, 151 patients with a suspected pancreatic neoplasm based on clinical, laboratory or other imaging data were examined between May 94 and October 95. Our newly developed Hydro-CT methodology included intravenous injection of 40 mg N-butylscopolaminium bromide (Buscopan) for intestinal paralysis, gastric and duodenal wall distension by oral administration of an average of 1.51 warm tap water, 30 degrees RAO patient positioning, an individualized contrast injection technique as determined beforehand by time-to-peak measurement in the portal vein and thin-slice spiral CT (3 mm increment, 6 mm table feed and 3 mm secondary reconstruction). A detailed evaluation form was used to assess (1) tumor detection rate, (2) differentiation of malignant versus benign disease, (3) differential diagnosis, and (4) accuracy of assessment of resectability by identification of infiltration into adjacent organs and vessel structures relevant for resectability such as splenic, superior mesenteric, portal vein and celiac trunk, superior mesenteric, splenic and hepatic arteries. As the gold standard for positive tumor detection surgery and microscopic diagnosis were used, and for negative tumor detection an event-free survival of 6 months. RESULTS: Almost all examinations were well tolerated. In only 4% was on-site administration of a gastric tube required because of vomiting. In 2% of the patients a slight allergic reaction to the contrast medium was seen. The prevalence of a pancreatic neoplasm was 38%. In tumor detection Hydro-CT reached an overall accuracy of 97.4% with a sensitivity of 100% and a specificity of 95.9%. In the differentiation of benign versus malignant disease Hydro-CT reached an overall accuracy of 89.7% with a sensitivity of 92.5% and a specificity of 83.3%. The prevalence of a pancreatic carcinoma was 24%; 4% other malignant tumors were found (distal common bile duct carcinoma, cystadenocarcinoma). Fifty-eight patients underwent surgical exploration. In those assessment of resectability reached an overall accuracy of 95% with a sensitivity of 90.5% and specificity of 100%. CONCLUSION: The new technique of Hydro-CT based on thin slice and spiral methodology, including pharmacological intestinal paralysis and water distension, results in a high tumor detection rate and increases sensitivity and specificity of tumor differential diagnosis and of assessment of resectability.

Adult↗
PubMed1996

[Intraoperative monitoring of the recurrent laryngeal nerve. A new method].

Injury of the recurrent laryngeal nerve (RLN) is one of the most frequent complications in thyroid surgery. It leads to a significant morbidity of up to 20%, depending on the type of surgery being performed. We present a new device for intraoperative monitoring of the RLN. The new monitoring system was evaluated in piglets. The system is reliable and easy to use. For the first time even imminent injury to the RLN can undoubtedly be demonstrated by signal changes. It will soon be available for use in humans.

Animals↗
PubMed1996

[Treatment of pain with peridural administration of opioids].

The advantages and disadvantages associated with epidural opioids require careful selection of the opioid and its dosage. There is presently no ideal opioid available for epidural use. Comparative pharmacokinetic data help to select the appropriate epidural opioid. Morphine (provided it is given in small doses and volumes) is very appropriate for epidural pain treatment, especially for longer periods of treatment, due to excellent analgesia and very low systemic morphine concentrations. The faster onset of analgesia with epidural pethidine, alfentanil und fentanyl make these opioids recommendable. However, due to the increased risk of respiratory depression during continuous treatment, these drugs should not be given over extended periods. Epidural administration of methadone, sufentanil und buprenorphine cannot be recommended since the advantages over systemic use do not outweigh the risks. Epidural tramadol may be useful in clinical routine, if opioids are not available and supervision of the patient is not guaranteed, because tramadol is not restricted by law and has a low potential for central depressive effects. The safety of the patients should be paramount. If patients are harmed by inappropriate opioids or dose regimens this will discredit a valuable for treating postoperative pain. Postoperative epidural dosages should be as low as possible and be titrated to the patient's individual needs for analgesia. Epidural morphine treatment is an alternative to step 4 of the WHO treatment regimen for patients with intractable pain or those suffering from systemic opioid side effects. Careful selection of patients helps to increase successful treatment. If implantable devices (ports or pumps, according to the life expectancy) are employed, the intrathecal route of administration is preferable to the epidural route, as the latter has a 10 times higher morphine dose requirement.

Analgesia, Epidural↗
PubMed1996

[Surgical procedure in children with medullary thyroid gland carcinoma with reference to multiple endocrine neoplasia type II].

Between 1988 and 1995 we treated ten patients aged 7-18 years for familial MTC or MEN II syndrome with a total of 17 operations. Using these surgical procedures, 6/9 patients remained free of tumor after 0-8 years (mean 4.5 years). In conclusion, we recommend thyroidectomy [1] in children younger than 5 years of age and a family history of MEN IIa; [2] in children younger than 3 years of age, presenting the characteristic phenotype of MEN IIb, both with a positive test for mutation of the RET protooncogene [4].

Adolescent↗
PubMed1996

[Oxygenation of liver transplants as a predictor of success].

Disturbances of microcirculation followed by an impaired tissue oxygenation contribute significantly to a possible organ dysfunction after liver implantation. This study investigated the influence of the explantation technique on and the possible predictive value of the liver transplant oxygenation. Two different explantation techniques were used. The livers were either explanted as rapidly as possible followed by the careful dissection of the vessels and the bile duct ex situ-rapid perfusion or were completely prepared--in situ perfusion in both groups, the livers were preserved by arterial and porto-venous infusion of ice-cold "UW"--solution. Local partial pressure values were obtained polarographically with miniaturized needle electrodes. The liver oxygenation directly after laparotomy was comparable in both groups. We systematically investigated the potential of liver oxygenation as a predictor of transplant quality.

Humans↗
PubMed1995

Dynamic liver scintigraphy: a new way of measuring the function of the reticuloendothelial system of the liver.

The phagocytic function and biokinetics of the hepatic reticuloendothelial system (RES) were evaluated using a 25-nm diameter colloid (Nanocoll) and a scintillation camera technique in opossums with obstruction of the pancreatic duct (group I) and additional obstruction of the common bile duct (group II). The liver net uptake curve was analysed using natural log regression. The regression curves proved to fit very well (r > 0.93) and a parameter R was calculated to describe the curves. In group I there was a slight but significant decrease in the RES function and no morphological change in the pancreas. In group II, RES function was significantly more suppressed than in group I. The opossums developed severe haemorrhagic pancreatitis. The results show that the regression parameter R is well suited to described liver RES function, and suggest that a suppressed liver RES after biliary obstruction could be an important factor in the pathogenesis of biliary pancreatitis.

Animals↗
PubMed1995

[Effect of anastomosis reconstruction on vascular complications after liver transplantation].

AIM: Besides primary non function (PNF), vascular complications are responsible for the majority of early surgical and interventional therapy following liver transplantation. The purpose of this study was to evaluate the influence of the variety of arterial anastomosis on postoperative morbidity and mortality. METHOD USED: In 179 liver transplantations, vascular (arterial and portal) complications within the first 3 months were analyzed with respect to the type of reconstruction. The arterial anastomoses were divided into 3 groups according to the recipient artery used [Group (I): common hepatic artery (CHA), (II): hepatic artery (HA), (III): aorta]. For statistical analysis comparison of two proportions and the logrank test were used. RESULTS: The reconstruction was done primarily to the recipient CHA (69%, n = 124), less often to the HA (15%, n = 26) or directly to the aorta (16%, n = 29). The portal anastomosis-with the exception of two cases (dacron graft and internal iliac vein interposition)-was always end to end and resulted in four reinterventions (2.2%, kinking: n = 1, thrombosis: n = 3). Arterial complications (11.7%) like thrombosis, stenosis and dissection (n = 17), bleeding (n = 2) and steal phenomenon (n = 2) occurred more frequently. The difference in one year survival between patients with (n = 12/25, 47%) and without (n = 42/53, 79%) vascular complications was significant (chi 2 = 4.72, FG 1, logrank test p < 0.05). CONCLUSION: The rate of complications causing surgical or interventional therapy is independent of the choice of arterial reconstruction. The one year survival rate in patients with vascular complications is significantly decreased.

Adolescent↗
PubMed1994

[Liver transplantation after surgical shunt or transjugular intrahepatic portasystemic shunt].

The goal of this study was to assess the influence of prior treatment of bleeding esophageal varices on liver transplantation. After sclerotherapy the results of liver transplantation were identical to those achieved in patients without previous variceal hemorrhage (74% 1-year survival). The results of liver transplantation to patients who already had surgical shunts were dismal. Four of nine patients with portocaval or Warren shunts were long-term survivors. In comparison, the intraoperative course in five patients with transjugular intrahepatic portosystemic stent shunts (TIPSS) was uneventful and four of these were long-term survivors. This has led us to adopt TIPSS as the treatment modality of choice for patients with bleeding varices awaiting liver transplantation.

Adult↗
PubMed1994

[The reticuloendothelial system. An overview of function, pathology and recent methods of measurement].

The Reticuloendothelial System (RES) consists of cells descending from the monocytes which are able to perform phagocytosis of foreign materials and particles. 90% of the RES are located in the liver. The most important function of the RES ist phagocytosis, but it also takes part in cytotoxicity against tumor cells and has a function in the regulation of the immune system. The importance of the RES is obvious in diseases of the bile ducts. An obstruction can lead to a decrease in the function of the RES. Beside a mathematical model there are also a few experimental methods to measure the phagocytic capacity and thus the efficiency of the RES. They are based on a clearance study of the amount of particles absorbed by the RES. This study can e.g. be done with Nanocoll which has been marked with 99mTc. But instead of the bloody clearance, a scintigraphic study using a gamma camera can be performed. With that, the increase time, the liver extraction fraction and the steepness of increase can be determined. Such a test could be of clinical relevance as a parameter for the prognosis of patients with trauma, sepsis or shock. The function of the RES in the pathogenesis of the biliary pancreatitis could also be examined closer with the help of such a test. The requirements a test of the RES should meet are reproducibility, repeatability and practicability.

Animals↗