Browsing by Author "Markus, Peter M."

Background: Intravital microscopy allows direct visualization of the hepatic microvasculature. We report on a novel application of this technique using a chamber model that simulates the conditions of pneumoperitoneum. Methods: For this purpose, we designed a peritoneal cavity chamber for rats. In the present study, we evaluated the technical procedure without any induction of increased intraabdominal pressure to assess undisturbed hepatic microcirculation. Intravital microscopy of the liver was performed in 12 rats. Animals that underwent the same operative procedure without the chamber served as controls (n = 12). Results: Hepatic sinusoidal perfusion rate, leukocyte endothelial cell interaction, and bile flow showed no significant differences between the groups. Operating time was longer in the chamber group. Conclusion: The peritoneal cavity chamber is an attractive approach for the study of hepatic microvascular, cellular, and molecular mechanisms that are important to our understanding of the potential harmful effects of laparoscopy on hepatic circulation and liver function.

Background/Purpose: Over the last 20 years, hepatocyte transplantation (HcTx) has advanced from the experimental to the clinical stage. To date, HcTx has been performed in 30 patients in the United States. Regardless whether hepatocytes are transplanted into the spleen and migrate to the liver or are injected directly into the portal vein, transplanted liver cells will, to some extent, congest the recipient liver microcirculation. The potential negative consequences of intrasplenic HcTx were the subject of this study. Methods: By using intravital microscopy, the authors investigated whether intrasplenic HcTx of 20 X 10(6) allogenic hepatocytes would influence liver perfusion, excretory liver function, and nonparenchymal cells (Kupffer and Ito cells) in vivo. Results: The sinusoidal perfusion rate declined significantly from 94% (control) to 84% on day 1 and 76% on day 7. Bile acid excretion decreased in a similar fashion from 0.924 mg/h (control) to 0.669 mg/h on day 7. The authors observed a significant increase of Ito cells from 81.1 cells per microscopic field (control) to 97.1 (day 1) and an increase of Kupffer cells (KC; 6.1 cells per microscopic field on day 1 v3.8 on control). Conclusions: This study shows an acute impairment of hepatic microcirculation and hepatucellular function along with an recruitment and activation of nonparenchymal cells in the early posttransplantation period after intrasplenic HcTx. Kupffer cell recruitment indicates an activation of local host defense, and Ito cell activation implies the initiation of liver repair mechanisms owing to ischemia-related cell damage. (C) 2004 Elsevier Inc. All rights reserved.

The course in Gastrointestinal Surgery (GISC) aims at teaching and training resection, reconstruction and suture techniques of the upper gastrointestinal tract. Prior to, after and 5 years following the first course, participants were asked to answer a questionnaire requesting information regarding the adequacy of surgical training in their residency program and how much they had benefited from the GISC. While 1/3 of the participants described the surgical training during their residency as inadequate, more than 90% benefited from the GISC. Although the single-layer-continuous suture technique was implemented by only 8% of the participating surgeons, other techniques such as cross-section gastroenterostomy were accepted by 38%. Only 7% of the participants rejected these new techniques, while 41% of the senior surgeons at home could not be convinced. Besides the teaching of new techniques, participants benefited above all from the repetitive training in surgical procedures.

Background and aims. The impact of laparoscopy on tumor progression is still unclear. This study investigated the effect of CO2 pneumoperitoneum on the intra-abdominal growth of human colon carcinoma independently of the effect of the immune system. Methods. SCID mice underwent either median laparotomy or laparoscopy. Human colon carcinoma cells were implanted into the upper abdomen. The control group was not operated on following cell injection. Tumor growth and the protein expression pattern of proliferation marker Ki67, cell-cell adhesion molecules E-cadherin, alpha- and beta-catenin, and cell-extracellular matrix adhesion molecules CD44 v5 and v6 in tumor tissue were analyzed on postoperative day 14. Results. Total tumor volume in the laparoscopy group significantly exceeded that in the laparotomy group. Immunohistochemistry revealed reduced expression of alpha-catenin and elevated expression on beta-catenin and CD44 v5 in the tumor tissue of the laparoscopy group. Conclusion. The expression pattern of proteins associated with tumor progression and the increase in tumor growth suggest an increased risk of laparoscopy at least for the growth of advanced human colon carcinoma.

The specific performance of the adult hepatic parenchymal cell is maintained and controlled by factors deriving from the stromal bed; the chemical nature of these factors is unknown. This study aimed to develop a serum-free hierarchical hepatocyte-nonparenchymal (stromal) cell coculture system. Hepatic stromal cells proliferated on crosslinked collagen in serum-free medium with epidermal growth factor, basic fibroblast growth factor, and hepatocyte-conditioned medium; cell type composition changed during the 2-wk culture period. During the first wk, the culture consisted of proliferating sinusoidal endothelial cells with well-preserved sieve plates, proliferating hepatic stellate cells, and partially activated Kupffer cells. The number of endothelial cells declined thereafter; stellate cells and Kupffer cells became the prominent cell types after 8 d. Hepatocytes were seeded onto stromal cells precultured for 4-14 d; they adhered to stellate and Kupffer cells, but spared the islands of endothelial cells. Stellate cells spread out on top of the hepatocytes; Kupffer cell extensions established multiple contacts to hepatocytes and stellate cells. Hepatocyte viability was maintained by coculture; the positive influence of stromal cell signals on hepatocyte differentiation became evident after 48 h; a strong improvement of cell responsiveness toward hormones could he observed in cocultured hepatocytes. Hierarchial hepatocyte coculture enhanced the glucagon-dependent increases in phosphoenolpyruvate carboxykinase activity and messenger ribonucleic acid (mRNA) content three- and twofold, respectively; glucagon-activated urea production was elevated twofold. Coculturing also stimulated glycogen deposition; basal synthesis was increased by 30% and the responsiveness toward insulin and glucose was elevated by 100 and 55%, respectively. The insulin-dependent rise in the glucokinase mRNA content was increased twofold in cocultured hepatocytes. It can be concluded that long-term signals from stromal cells maintain hepatocyte differentiation. This coculture model should, therefore, provide the technical basis for the investigation of stroma-derived differentiation factors.

Background/Aims: A major problem in rat liver endothelial cell culture is the rapid loss of cells after 48 h, This study aimed to develop a protocol that allowed easy maintenance and proliferation of sinusoidal endothelial cells in serum-free culture for 5-6 days. Methods: Cells isolated from adult rat liver by collagenase digestion were purified by centrifugal elutriation and cultured on glutaraldehyde-crosslinked collagen, Results: At high plating densities cells could be maintained serum-free for 6 days in the presence of hydrocortisone and basic fibroblast growth factor; at lower plating densities medium had to be supplemented with additional growth-promoting factors. Conditioned medium of adult rat hepatocytes proved to be the most effective growth stimulus; it increased thymidine incorporation, DNA content and cell number per dish with a half-maximal effect at 20% (v/v), Cell proliferation was also observed with either vascular endothelial growth factor, phorbol ester or conditioned media from FAO or HEPG2 liver cell lines provided the cultures were additionally supplemented with 1% newborn calf serum. Vascular endothelial growth factor was detected in all conditioned media. In the absence of hepatocyte-conditioned medium, 1% serum helped to maintain cultures; it itself exerted a low proliferative effect. Higher serum concentrations (>5%), however, led to cell loss after 48 h, The numerous sieve plates of 6-h-old cells progressively disappeared during culture and were replaced by randomly distributed pores, which later grouped together at cell-cell borders. More than 90% of the cells endocytosed acetylated low-density lipoprotein, Conclusions: The study shows that cultured hepatocytes secrete growth-promoting substances that stimulate in vitro endothelial cell proliferation in the absence of serum; this effect could be mimicked by the combined addition of vascular endothelial growth factor and 1% serum. The new media formulations should facilitate future research on liver endothelial cells in mono- or coculture.

Background and aims: Alterations in microvascular perfusion of the intestine after hepatic ischemia/ reperfusion have been suggested as an important cause of postoperative septic complications. We therefore investigated small bowel microcirculation and mucosal injury after liver ischemia/ reperfusion in a rat model. Furthermore, we analyzed the effects of the regulatory peptides vasoactive intestinal polypeptide and gastrin-releasing peptide for their splanchnic vasoactivity. Methods: Hepatic ischemia was induced by clamping of the left hepatic artery and vein for 40 min, followed by 60 min of reperfusion. The control group was treated similarly, but without clamping of the liver vessels. Ten minutes after clamping of the hepatic vessels, vasoactive intestinal polypeptide or gastrin-releasing peptide, respectively, were continuously infused intravenously in the experimental groups. Small bowel microcirculation and mucosal injury were assessed using intravital microscopy and the Chiu-score, respectively. Results: The functional capillary density of the small intestine following ischemia and reperfusion of the left hepatic lobe significantly decreased compared to normal controls in both the mucosa and the smooth intestinal muscle. Red blood cell velocity decreased, whereas leukocyte endothelium adherence, stasis index and the mucosal injury score increased. Administration of vasoactive intestinal polypeptide resulted in an increase of functional capillary density in the mucosa and of the red blood cell velocity and a decrease in the stasis index. The mucosal injury score was significantly higher in reperfused animals without treatment. The application of gastrin-releasing peptide resulted in an isolated increase of the red blood cell velocity. Leukocyte adherences could not be altered by the regulatory peptides. Conclusion: We conclude that hepatic ischemia/reperfusion injury leads to significant alterations of small bowel microcirculation and mucosal injury. Vasoactive intestinal polypeptide and gastrin-releasing peptide attenuate the damage in a different manner.

Background: The effectiveness of laparoscopic Nissen fundoplication (LNF) was assessed in patients with chronic gastroesophageal reflux disease (GERD) using pH study and different quality-of-life indexes. We correlated both types of data and hypothesised that improvement in quality of life following LNF does not necessarily correlate with improvement in pH values. Methods: Seventy patients presenting with typical symptoms of GERD (14 with Barrett's esophagus) underwent LNF between May 1997 and December 2000. All patients were evaluated both prior to and 3 months after surgery using 24-h pH study, endoscopy, and a validated quality-of-life questionnaire. Results: Following LNF. reflux was reduced to normal in all but six patients. Howevers despite persistent reflux, the Gastrointestinal Quality of Life Index (GQLI), of these six patients improved postoperatively from 79.5 +/- 2.2 to 111.7 +/- 8.3. These results correlate with those of patients who had normal postoperative pH studies-namely, 88.5 +/- 19.3 to 112 +/- 16.7. There was no difference in quality-of-life improvement between patients with Barrett's esophagus and those without it. Conclusion: There is only a weak correlation between quality-of-life assessment and pH study. Because the patient's quality of life is likely to improve following LNF, an objective means parameter of assessing the effectiveness of antireflux surgery, such as pH study or endoscopy, is recommended.

The mechanisms of donor hepatocyte integration into recipient liver are not fully understood. We investigated mechanisms of both the integration and interaction of transplanted hepatocytes with host liver cells as well as the repopulation of the host organ following intraportal transplantation. Mature hepatocytes were injected into the portal vein of dipeptidylpeptidase IV (DPPIV)-deficient rats pretreated with retrorsine and subjected to 30% partial hepatectomy to ensure selective donor growth. The degree of integration and proliferation was studied by colocalizing transplanted cells (DPPIV positive) with connexin 32, MMP-2, and OX-43 (multilayer immunotluorescence imaging). FACS analysis was established to assess the extent of repopulation quantitatively. Transplanted hepatocytes reached the distal portal spaces and sinusoids within l h after injection. A small proportion of cells succeeded in traversing the endothelial barrier through mechanical disruption in both locations. Transplanted hepatocytes lost their membrane-bound gap junctions (connexin 32) during this process. Successful integration of the donor cells required up to 5 days, heralded by gap junction reconstitution and the specific basolateral membrane expression of DPPIV. MMP-2 degraded the extracellular matrix in close proximity to donor cells, providing space for cell division. FAGS analysis revealed that more than 37% of the liver was repopulated by cells derived from donors at 2 months after transplantation. Our data demonstrate a high degree of donor cell repopulation of the host organ and provide valuable insight into the specific mechanisms of donor cell integration. Connexin 32 expression in transplanted hepatocytes may serve as an indicator of their effective incorporation and communication within the recipient liver. FACS analysis reveals an accurate method to determine quantitatively the extent of liver repopulation.

In the past decade laparoscopic surgery replaced many open operations in general surgery. Apart from therapeutic uses in cholecystectomy, appendectomy, hernia surgery, gastric fundoplication, and increasingly also large intestine surgery, it is indicated diagnostically first of all for unclear abdominal findings and for staging of intra-abdominal malignancies. To date laparoscopy has been used occasionally for diagnosis and therapy of mesenteric ischemia. Patients suffering from mesenteric ischemia are usually old and have comorbid conditions. Quick diagnosis and therapy are necessary due to the pathogenesis of the disease. The low rate of morbidity as well as the easy availability of laparoscopy in principle favor the employment of laparoscopy also for mesenteric ischemia. Against the background of increasing experience in the area of laparoscopic surgery, this study gives an overview of the present value of laparoscopy for mesenteric ischemia.

The laparascopic transabdominal preperitoneal (TAPP) repair of an inguinal hernia is an established technique associated with notably low rates of recurrence and complication. Inguinal pain and anal bleeding following a TAPP procedure may result from the penetration of the repair mesh into the sigmoid colon. In this case report, we discuss this particular complication following the TAPP procedure. Subsequently, we describe the diagnostics as well as the surgical treatment necessary.

Acute rejection-induced microvascular injury results in graft dysfunction, ultimately leading to graft loss. Infiltration of T cells and monocytes as a consequence of an enhanced endothelial cell-leukocyte interaction appears to play an important role in this deleterious process. Recruitment of these pro-inflammatory cells to the vessel wall is mediated by chemokines such as RANTES. Heterotopic small bowel transplantation was performed in rats with the fully allogeneic Brown Norway-Lewis strain combination and, as a control, the syngeneic Lewis-Lewis strain combination. Intravital microscopy was performed from postoperative day 1-7 in both groups. The percentages of perfused villi and villus stasis, mucosal and muscular functional capillary densities, red blood cell velocities, and finally, firm adherence of leukocytes in postcapillary submucosal venules were assessed. Syngeneic small bowel transplantation revealed homogeneous perfusion of villi and muscle layers over the whole study period. Allogeneic small bowel transplantation showed a decline in perfusion from postoperative day 1 until complete failure on postoperative day 7. This was accompanied by a continuous increase in endothelial cell-leukocyte interaction which reached a plateau on postoperative day 5. Met-RANTES treatment at 200 mug/day for 5 days markedly attenuated both the decrease in functional capillary density and the increased endothelial cell-leukocyte interaction in rats following allogeneic small bowel transplantation. We conclude that blocking chemokine receptors, thereby limiting endothelial cell-leukocyte interaction, may constitute a useful therapeutic approach to the prevention of microcirculatory perfusion failure in acute transplant rejection. Copyright (C) 2002 S. Karger AG, Basel.

Background: To date, the effects of increased abdominal pressure, as given during carbon dioxide (CO2) pneumoperitoneum, on hepatic microcirculation and biliary excretion are unknown. Methods: Using a custom-made peritoneal cavity chamber, we performed intravital microscopy of the left liver lobe under conditions of CO) pneumoperitoneum in a rat model. In addition, biliary excretion was assessed. Results: The establishment of a CO2 pneumoperitoneum of 4 or 8 mmHg resulted in sinusoidal perfusion failure that was more pronounced in the periportal regions than in the midzonal and pericentral regions of the liver acinus. Biliary excretion was considerably reduced at an intraabdominal pressure of 8 mmHg. Leukocyte-endothelial cell interactions increased significantly in both hepatic sinusoids and postsinusoidal venules. Conclusion: Alterations in hepatic microcirculation and liver function must be taken into consideration in any kind of laparoscopic surgery and may be of particular clinical relevance in patients with liver pathology.

Totally extraperitoneal. preparation (TEP) of an inguinal hernia is an established method of treating inguinal hernias associated with an acceptable complication rate (2-12%) and low rate of recurrence (0-3%). This is the first reported case of sensorimotor paralysis of the femoral nerve following the complete endoscopic mesh treatment of a primary inguinal hernia to the left side. Following a discussion of the necessary diagnostic and therapeutic steps, traumatic postsurgical paralysis of the nerve as well as spontaneous paralysis of the femoral nerve are discussed. The prognosis is positive given the lack of macroscopic evidence of any direct damage to the nerve.

We report herein the case of a 48-year-old man with long-term persistent primary hyperparathyroidism (pHPT) despite undergoing a parathyroidectomy in 1976, followed by a reoperation in 1978, for whom resection of a parathyroid adenoma in the upper mediastinum was eventually performed. His postoperative course was complicated by recurrent hypocalcemia refractory to oral calcium substitution and significantly elevated levels of parathyroid hormone (PTH). The radiological findings are presented, and we discuss the possible reasons for the coincidence of severe hypocalcemia with increased PTH levels in association with pHPT.

Purpose: Although complete resection (190) of liver metastases (LM) remains the treatment of choice for colorectal cancer (CRC) patients amenable to curative therapy, only approximately one third survive for 5 years. The objective of this phase II study was to evaluate the safety and efficacy of radioimmunotherapy (RAIT) after salvage resection of LM. Patients and Methods: Twenty-three patients who underwent surgery for LM of CRC received a dose of 40 to 60 mCi/m(2) Of I-131-labetuzumab, which is a humanized monoclonal antibody against carcinoembryonic antigen. Safety (n = 23), disease-free survival (DFS; n = 19), and overall survival (OS; n = 19) were determined. Results: With a median follow-up of 64 months, the median OS time from the first liver resection for RAIT patients was 68.0 months (95% Cl, 46.0 months to infinity), and the median DFS time was 18.0 months (95% Cl, 11.0 to 31.0 months). The 5-year survival rate was 51.3%. RAIT benefited patients independently of bilobar involvement, size and number of LM, and resection margins. The major adverse effect was transient myelosuppression, resulting mostly in grade <= 3 neutropenia and/or thrombocytopenia. Conclusion: Because both the median OS and 5-year survival rates seem to be improved with adjuvant RAIT after complete LM resection in CRC, compared with historical and contemporaneous controls not receiving RAIT, these results justify further evaluation of this modality in a multicenter, randomized trial.

Background: The aim of this study was to determine the accuracy of prediction of the surgeon's 'gut-feeling' in estimating postoperative outcome. Methods: A prospective series of 1077 consecutive patients undergoing major hepatobiliary or gastrointestinal surgery were studied. Patients having elective (n = 827) and emergency (n = 250) procedures were included. The surgeon predicted the development of postoperative complications immediately after completion of surgery on a scale from 0 to 100 per cent. These predictions were compared with the actual outcome and with predictions made using the Physiological and Operative Severity Score for the enUmeration of Mortality and morbidity (POSSUM). The Portsmouth predictor equation (P-POSSUM) was applied for the estimation of mortality. Results: The observed morbidity and mortality rates were 29.5 and 3.4 per cent respectively. POSSUM predicted a morbidity rate of 46.4 per cent and P-POSSUM a mortality rate of 6.9 per cent. The surgeon's gut-feeling was more accurate in the prediction of morbidity at 32.1 per cent. On the basis of gut-feeling, surgeons overpredicted morbidity in elective surgery, but underestimated the risk of complications in the emergency setting. The (P)-POSSUM scoring system overpredicted morbidity and mortality for elective and emergency operations. Conclusion: The surgeon's gut-feeling is a good predictor of postoperative outcome, especially after elective surgery. (P)-POSSUM overpredicted morbidity and mortality in this series of major gastrointestinal and hepatobiliary operations.