[How does the surgical society (DGAV) support the continuing medical training in general and visceral surgery?]

The medical councils (Ärztekammern) develop the contents of the further training regulations with the support of the specialist society. The hospitals with the training supervisors have to implement these contents for the trainees in continuing education and confirm the acquisition of competence for the individual tasks. Surveys of young surgeons in recent years have shown that many participants do not receive structured continuing education, so that there is general dissatisfaction. Therefore, the German Society for General and Visceral Surgery (DGAV) is required to provide assistance to its members to improve continuing education in the departments. For example, the DGAV organizes more than 100 surgical courses annually on all topics of visceral surgery, anatomy, skills courses and revision courses with the Further Education and Advanced Training Quality Center (WeiFoQ). This year a continuing education curriculum was developed over the 6‑year continuing education period, so that a structured continuing education is achievable. The contents of the continuing education regulations are included in this continuing education curriculum with explanations, video clips, and graphics, thus providing quick information on each individual surgical clinical picture. A digital surgical catalog provides a quick overview of the status of personal continuing education. It is planned to set up an interface to the eLogbook of the medical councils.

Dragon 1 Protocol Manuscript: Training, Accreditation, Implementation and Safety Evaluation of Portal and Hepatic Vein Embolization (PVE/HVE) to Accelerate Future Liver Remnant (FLR) Hypertrophy

STUDY PURPOSE

The DRAGON 1 trial aims to assess training, implementation, safety and feasibility of combined portal- and hepatic-vein embolization (PVE/HVE) to accelerate future liver remnant (FLR) hypertrophy in patients with borderline resectable colorectal cancer liver metastases.

METHODS

The DRAGON 1 trial is a worldwide multicenter prospective single arm trial. The primary endpoint is a composite of the safety of PVE/HVE, 90-day mortality, and one year accrual monitoring of each participating center. Secondary endpoints include: feasibility of resection, the used PVE and HVE techniques, FLR-hypertrophy, liver function (subset of centers), overall survival, and disease-free survival. All complications after the PVE/HVE procedure are documented. Liver volumes will be measured at week 1 and if applicable at week 3 and 6 after PVE/HVE and follow-up visits will be held at 1, 3, 6, and 12 months after the resection.

RESULTS

Not applicable.

CONCLUSION

DRAGON 1 is a prospective trial to assess the safety and feasibility of PVE/HVE. Participating study centers will be trained, and procedures standardized using Work Instructions (WI) to prepare for the DRAGON 2 randomized controlled trial. Outcomes should reveal the accrual potential of centers, safety profile of combined PVE/HVE and the effect of FLR-hypertrophy induction by PVE/HVE in patients with CRLM and a small FLR.

TRIAL REGISTRATION

Clinicaltrials.gov: NCT04272931 (February 17, 2020). Toestingonline.nl: NL71535.068.19 (September 20, 2019).

[Implementation of fast-track measures in colorectal resections : A survey among members of the DGAI]

PURPOSE

The fast-track (FT) concept is a multimodal, interdisciplinary approach to perioperative patient care intended to reduce postoperative complications. Despite good evidence implementation seems to need improvement, whereby almost all studies focused on the implementation of surgical modules regardless of the interdisciplinary aspect. Adherence to the anesthesiological measures (prehabilitation, premedication, volume and temperature management, pain therapy), on the other hand, has been insufficiently studied. To assess the status quo a survey on the implementation of anesthesiological FT measures was conducted among members of the German Society of Anesthesiology and Intensive Care Medicine (DGAI) to analyze where potential for improvement exists.

METHODS

Using the SurveyMonkey® online survey tool, 28 questions regarding perioperative anesthesiological care of colorectal surgery patients were sent to DGAI members in order to analyze adherence to FT measures.

RESULTS

While some of the FT measures (temperature management, PONV prophylaxis) are already routinely used, there is a divergence between current recommendations and clinical implementation for other components. In addition to premedication, interdisciplinary measures (prehabilitation) and measures that affect multiple interfaces (operating theatre, recovery room, ward), such as volume management or perioperative pain management, are particularly affected.

CONCLUSION

The anesthesiological recommendations of the FT concept are only partially implemented in Germany. This particularly affects the interdisciplinary components as well as measures at the operating theatre, recovery room and ward interfaces. The establishment of an interdisciplinary FT team and interdisciplinary development of SOPs can optimize adherence, which in turn improves the short-term and long-term outcome of patients.

[Evidence of indocyanine green fluorescence in robotically assisted colorectal surgery : What is the status?]

BACKGROUND

Indocyanine green (ICG) fluorescence imaging is increasingly being used in various areas of abdominal surgery. The constant improvement in the technology enables easy intraoperative use and progressively influences operative decision-making, also in robotically assisted colorectal surgery.

OBJECTIVE

Summation of current evidence on the use of ICG fluorescence imaging in robotically assisted colorectal surgery.

MATERIAL AND METHODS

The assessment of evidence is based on a comprehensive literature search (PubMed).

RESULTS

First individual studies (feasibility, case matched, prospective cohort, multicenter phase II, single center randomized controlled study/trial) showed a significant reduction in the incidence of anastomotic leakage (AL) after colorectal anastomosis through the use of ICG fluorescence angiography (FA, 9.1% vs. 16.3%; p = 0.04). First feasibility studies demonstrated lymph node detection or navigation as well as ureter visualization.

CONCLUSION

The ICG-FA reliably detects tissue perfusion, quickly and effectively with few side effects. It can influence intraoperative decision-making and reduce AL rates. In addition, patients may be offered more precise tumor therapy via ICG sentinel lymph node (SLN) detection and lateral pelvic lymph node (LPN) mapping and navigation. Iatrogenic lesions, such as ureteral injuries can be sufficiently prevented by appropriate visualization; however, valid data in order to be able to derive standardized operative consequences require further convincing multicenter, randomized controlled trials (mRCT).

[Recommendations on treatment of acute appendicitis : Recommendations of an expert group based on the current literature]

The paradigm shift in the treatment concept for acute appendicitis is currently the subject of intensive discussions. The diagnosis and differentiation of an uncomplicated from a complicated appendicitis as well as the selection of an adequate treatment is very challenging, especially since nonoperative treatment models have been published. The laparoscopic appendectomy is still the standard for most cases. Guidelines for the treatment of acute appendicitis do not exist in Germany. Therefore, a group of experts elaborated 21 recommendations on the treatment of acute appendicitis after 3 meetings. After initial definition of population, intervention, comparison and outcome (PICO) questions, recommendations have been finalized through the Delphi voting system. The results were evaluated according to the current literature. The aim of this initiative was to define a basic support for decision making in the clinical routine for treatment of acute appendicitis.

[Esophageal variceal bleeding: management and tips on transjugular intrahepatic portosystemic shunt]

BACKGROUND

Esophageal variceal bleeding is a life-threatening complication in patients with liver cirrhosis, which is pathophysiologically explained by the presence of portal hypertension. The incidence of such bleeding greatly depends on the severity of the underlying liver disease.

OBJECTIVE

The aim of this article is to present the current treatment concepts for acute esophageal variceal bleeding, the management in acute situations and the indications for treatment of the causal portal hypertension with a transjugular intrahepatic portosystemic shunt (TIPS).

RESULTS

In patients with liver cirrhosis or any other disease causing portal hypertension, a staging examination by esophagogastroduodenoscopy is first carried out for determination of the stage of the varices and the resulting necessary treatment. In addition, determination of the portal pressure gradient is useful. In patients with varices a medicinal or endoscopic bleeding prophylaxis should subsequently additionally be initiated. After an acute variceal bleeding event, under clearly defined prerequisites an evaluation for TIPS implantation should be considered. This is the only effective treatment for reducing portal hypertension.

CONCLUSION

With appropriate indications implantation of a TIPS is an effective strategy to lower portal hypertension and therefore prevent recurrent variceal bleeding. The resulting improvement of the portal hemodynamics leads to an improvement in kidney function; however, it also leads to deterioration of liver function with subsequent development or deterioration of a previously existing hepatic encephalopathy.

[Treatment approach for gall bladder and extrahepatic bile duct cancer]

BACKGROUND

Although the treatment and diagnostic regimens of gall bladder carcinoma and extrahepatic bile duct cancer have improved over the past years, the outcome and overall survival as prognostic values still remain poor. Early tumor stages of gall bladder carcinoma are the only exception.

OBJECTIVE

This article focuses on the latest surgical therapy approaches including neoadjuvant, adjuvant and palliative therapy regimens.

RESULTS

Neoadjuvant treatment concepts have so far been insufficiently evaluated and can therefore only be recommended within the framework of studies. In patients with primary resectable tumors there are so far no indications for improved results after neoadjuvant therapy. Radical R0 resection still remains the only curative treatment option; however, an advanced and inoperable stage is often already present at the time of diagnosis There are no uniform adjuvant treatment concepts and no standards evaluated by studies. Due to the currently available data, adjuvant radiochemotherapy and chemotherapy can also only be recommended within or as part of clinical trials. Palliative chemotherapy should only be used in advanced tumor stages and depending on the condition of the patient.

CONCLUSION

To sustainably improve treatment strategies for advanced gall bladder carcinoma and extrahepatic bile duct cancer, uniform adjuvant as well as neoadjuvant therapy regimens need to be developed after evaluation in prospective randomized trials. This is the only way to improve the still poor prognosis of these tumor entities.

Promoter hypermethylation of SHOX2 and SEPT9 is a potential biomarker for minimally invasive diagnosis in adenocarcinomas of the biliary tract

BACKGROUND

Biliary tract carcinoma (BTC) is a fatal malignancy which aggressiveness contrasts sharply with its relatively mild and late clinical presentation. Novel molecular markers for early diagnosis and precise treatment are urgently needed. The purpose of this study was to evaluate the diagnostic and prognostic value of promoter hypermethylation of the SHOX2 and SEPT9 gene loci in BTC.

METHODS

Relative DNA methylation of SHOX2 and SEPT9 was quantified in tumor specimens and matched normal adjacent tissue (NAT) from 71 BTC patients, as well as in plasma samples from an independent prospective cohort of 20 cholangiocarcinoma patients and 100 control patients. Receiver operating characteristic (ROC) curve analyses were performed to probe the diagnostic ability of both methylation markers. DNA methylation was correlated to clinicopathological data and to overall survival.

RESULTS

SHOX2 methylation was significantly higher in tumor tissue than in NAT irrespective of tumor localization (p < 0.001) and correctly identified 71% of BTC specimens with 100% specificity (AUC = 0.918; 95% CI 0.865-0.971). SEPT9 hypermethylation was significantly more frequent in gallbladder carcinomas compared to cholangiocarcinomas (p = 0.01) and was associated with large primary tumors (p = 0.01) as well as age (p = 0.03). Cox proportional hazard analysis confirmed microscopic residual tumor at the surgical margin (R1-resection) as an independent prognostic factor, while SHOX2 and SEPT9 methylation showed no correlation with overall survival. Elevated DNA methylation levels were also found in plasma derived from cholangiocarcinoma patients. SHOX2 and SEPT9 methylation as a marker panel achieved a sensitivity of 45% and a specificity of 99% in differentiating between samples from patients with and without cholangiocarcinoma (AUC = 0.752; 95% CI 0.631-0.873).

CONCLUSIONS

SHOX2 and SEPT9 are frequently methylated in biliary tract cancers. Promoter hypermethylation of SHOX2 and SEPT9 may therefore serve as a minimally invasive biomarker supporting diagnosis finding and therapy monitoring in clinical specimens.

[Ruptured Abdominal Aortic Aneurysm - Results and Prognostic Factors at a Certified Centre of Vascular Surgery]

Introduction: Although the perioperative management has been optimised over the past few decades, there has not been a remarkable improvement in the mortality rates of patients with a ruptured abdominal aortic aneurysm (rAAA). The aim of this retrospective trial was to define pre-, intra- and postoperative parameters which influence the perioperative and long-term outcome of patients and which can be modified by the operating team. Methods: A retrospective database analysis was performed in 49 patients who had undergone an operation of rAAA in our certified centre of vascular surgery between the beginning of 2006 and the end of 2012. The minimal follow-up period was 30 months. The statistical analysis was done univariately using the Kaplan-Meier method and a log-rank-test, and multivariately with the Cox model. Results: Intrahospital mortality was 40.8 %, perioperative mortality (30 postoperative days) was 28.9 %. The survival rate for 1 year was 52.4 %; the survival rate for 5 years was 45.3 %. In the univariate analysis, significant differences in the early postoperative survival rates were found depending on preoperative systolic blood pressure, preoperative haemoglobin (< 10 vs. ≥ 10 g/dl), the intraoperative need of blood and frozen plasma transfusions, type of perforation, type of AAA, the need for further surgical interventions, postoperative MOF, acute kidney failure and postoperative septicaemia. The late survival rates were significantly influenced by the type of perforation and AAA, pre-existing coronary disease and diabetes mellitus in fully identified patients discharged from hospital (n = 27). In the multivariate analysis pursuant to the Cox model, patients with pre-existing coronary disease had a 3.9-fold higher relative risk to die after the operation of rAAA, while patients with a free perforation of the rAA had a 10-fold higher relative risk. Conclusion: The high mortality of rAAA is caused by haemorrhagic shock and its complications, which are mostly non-surgical. Therapeutic efforts should focus on those perioperative parameters which can be modified by the treating teams. Alongside the centralisation of rAAA in high-volume-departments of vascular surgery, the systematic sonographic screening for asymptomatic AAA in the population older than 65 years should be enforced. A possible advantage of EVAR in rAAA has yet to be shown by trials in progress such as IMPROVE, AJAX and RCAR.

[Posthepatectomy Liver Failure in Extended Liver Resections: An Overview Based on a Retrospective Single-Centre Analysis]

BACKGROUND

Posthepatectomy liver failure (PHLF) is one of the most serious complications after major liver resections and an important factor in terms of perioperative morbidity and mortality. Despite many advances in the understanding and grading of PHLF, the definitions found in literature are very heterogeneous, which complicates the identification of high-risk patients. In this study we analysed the results of extended liver resections and potential risk factors for PHLF based on patient data derived from our tertiary referral centre. The aim of the study was to gain an overview of the essential aspects in the prevention of PHLF combined with key intraoperative issues and postoperative treatment strategies.

METHODS

We analysed data from 202 patients who underwent extended elective liver resections at our centre between April 1989 and September 2009 (135 right hemihepatectomies, 39 left hemihepatectomies, 28 right trisectionectomies). According to Balzan's "50/50 criteria", PHLF was defined as prothrombin time (PT) < 50 % combined with serum bilirubin (SB) > 50 micromol/L on postoperative day (POD) 5 or as death due to primary or secondary liver failure.

RESULTS

Thirty-day mortality and overall in-hospital mortality were 4.95 and 8.91 %, respectively. Twenty-eight (14 %) patients developed PHLF and 16 (57 %) patients died. Compared to patients with normal postoperative liver function, several significant pre- and intraoperative factors for PHLF were identified, e.g. primary malignant liver tumour (p < 0.001), extended liver resection (p < 0.001), time of surgery (p < 0.001) and intraoperative transfusion of packed RBC (p < 0.02) or FFP (p < 0.001).

CONCLUSION

Although progress has been made in hepatobiliary surgery, PHLF remains a serious complication, especially after extended liver resections. Careful, optimised preoperative risk stratification is required to identify patients at risk for PHLF.

[Hospital disinfection challenges due to multiresistant pathogens in surgery]

The number of antibiotic-resistant pathogens is increasing continuously while the development of new, effective antibiotics cannot be expected in the near future. Postoperative infections represent most of the nosocomial infections by now. Based on this, hygienic strategies regain importance, since a sustainable control of nosocomial infections will not succeed without the implementation of such strategies. In this article, the most important preventive strategies for prevention of infections with MRSA and 3- and 4-fold resistant gram-negative bacteria on the basis of current recommendations of the Commission for Hospital Hygiene and Infection Prevention (KRINKO) are presented.

Effects of macrophage-dependent peroxisome proliferator-activated receptor γ signalling on adhesion formation after abdominal surgery in an experimental model

BACKGROUND

The pathophysiology of adhesion formation after abdominal and pelvic surgery is still largely unknown. The aim of the study was to investigate the role of macrophage polarization and the effect of peroxisome proliferator-activated receptor (PPAR) γ stimulation on adhesion formation in an animal model.

METHODS

Peritoneal adhesion formation was induced by the creation of ischaemic buttons within the peritoneal wall and the formation of a colonic anastomosis in wild-type, interleukin (IL) 10-deficient (IL-10(-/-) ), IL-4-deficient (IL-4(-/-) ) and CD11b-Cre/PPARγ(fl) (/fl) mice. Adhesions were assessed at regular intervals, and cell preparations were isolated from ischaemic buttons and normal peritoneum. These samples were analysed for macrophage differentiation and its markers, and expression of cytokines by quantitative PCR, fluorescence microscopy, arginase activity and pathological examination. Some animals underwent pioglitazone (PPAR-γ agonist) or vehicle treatment to inhibit adhesion formation. Anastomotic healing was evaluated by bursting pressure measurement and collagen gene expression.

RESULTS

Macrophage M2 marker expression and arginase activity were raised in buttons without adhesions compared with buttons with adhesions. IL-4(-/-) and IL-10(-/-) mice were not affected, whereas CD11b-Cre/PPARγ(fl) (/fl) mice showed decreased arginase activity and increased adhesion formation. Perioperative pioglitazone treatment increased arginase activity and decreased adhesion formation in wild-type but not CD11b-Cre/PPARγ(fl) (/fl) mice. Pioglitazone had no effect on anastomotic healing.

CONCLUSION

Endogenous macrophage-specific PPAR-γ signalling affected arginase activity and macrophage polarization, and counter-regulated peritoneal adhesion manifestation. Pharmacological PPAR-γ agonism induced a shift towards macrophage M2 polarization and ameliorated adhesion formation in a macrophage-dependent manner. Surgical relevance Postoperative adhesion formation is frequently seen after abdominal surgery and occurs in response to peritoneal trauma. The pathogenesis is still unknown but includes an imbalance in fibrinolysis, collagen production and inflammatory mechanisms. Little is known about the role of macrophages during adhesion formation. In an experimental model, macrophage M2 marker expression was associated with reduced peritoneal adhesion formation and involved PPAR-γ-mediated arginase activity. Macrophage-specific PPAR-γ deficiency resulted in reduced arginase activity and aggravated adhesion formation. Pioglitazone, a PPAR-γ agonist, induced M2 polarization and reduced postoperative adhesion formation without compromising anastomotic healing in mice. Pioglitazone ameliorated postoperative adhesion formation without compromising intestinal wound healing. Therefore, perioperative PPAR-γ agonism might be a promising strategy for prevention of adhesion formation after abdominal surgery.

[Complications after Percutaneous Endoscopic Gastrostomy Tube Placement - A Retrospective Analysis]

BACKGROUND

Enteral nutrition is vital for patients with inadequate or absent oral food intake, as it can help to avoid catabolic metabolism. Enteral feeding can be secured by placing a percutaneous endoscopic gastrostomy tube (PEG-tube) which is an approved method. Several clinical studies could verify the superiority of this procedure compared to other options. Even though PEG-tube placement is regarded as less invasive surgery, a considerable rate of complications is reported in literature.

MATERIAL/METHODS

Here, we report a retrospective analysis of PEG-tube placements in the Bonn University Hospital from January 2005 to December 2012.

RESULTS

Overall, 641 PEG-tubes were placed with a complication rate of 9.4 %, which can be further divided in 5.5 % minor complications (mic) and 3.9 % major complications (mac). Two cases of death occurred in the context of PEG-tube placement. Endoscopically inserted PEG-tubes showed a complication rate of 8.6 % (4.8 % mic, 3.8 % mac). 63.2 % of mac consisted of perforations, 15.8 % of intra-abdominal abscesses and 15.8 % of buried bumper syndromes. The complication rate of CT-guided placement of PEG-tubes was 38.9 % (27.8 % mic, 11.1 % mac). In this group, all mac were perforations. Surgical PEG-tube placement was accompanied by no mac and 7.7 % mic.

CONCLUSION

The amount of complications during PEG-tube placement is remarkable, therefore the indication of this procedure must be contemplated critically and careful follow-up is crucial.

The novel CGRP receptor antagonist BIBN4096BS alleviates a postoperative intestinal inflammation and prevents postoperative ileus

BACKGROUND

Abdominal surgery results in neuronal mediator release and subsequent acute intestinal hypomotility. This phase is followed by a longer lasting inflammatory phase resulting in postoperative ileus (POI). Calcitonin gene-related peptide (CGRP) has been shown to induce motility disturbances and in addition may be a candidate mediator to elicit neurogenic inflammation. We hypothesized that CGRP contributes to intestinal inflammation and POI.

METHODS

The effect of CGRP in POI was tested in mice treated with the highly specific CGRP receptor antagonist BIBN4096BS and in CGRP receptor-deficient (RAMP-1(-/-) ) mice. POI severity was analyzed by cytokine expression, muscular inflammation and gastrointestinal (GI) transit. Peritoneal and muscularis macrophages and mast cells were analyzed for CGRP receptor expression and functional response to CGRP stimulation.

KEY RESULTS

Intestinal manipulation (IM) resulted in CGRP release from myenteric nerves, and a concurrent increased interleukin (IL)-6 and IL-1β transcription and leukocyte infiltration in the muscularis externa and increased GI transit time. CGRP potentiates IM-induced cytokine transcription within the muscularis externa and peritoneal macrophages. BIBN4096BS reduced cytokine levels and leukocyte infiltration and normalized GI transit. RAMP1(-/-) mice showed a significantly reduced leukocyte influx. CGRP receptor was expressed in muscularis and peritoneal macrophages but not mast cells. CGRP mediated macrophage activation but failed to induce mast cell degranulation and cytokine expression.

CONCLUSIONS & INFERENCES

CGRP is immediately released during abdominal surgery and induces a neurogenic inflammation via activation of abdominal macrophages. BIBN4096BS prevented IM-induced inflammation and restored GI motility. These findings suggest that CGRP receptor antagonism could be instrumental in the prevention of POI.

[Surgical Therapy and Prognostic Factors for Carcinoma of Vater's Papilla]

BACKGROUND

Carcinoma of ampulla of Vater are rare tumours of the GI-tract with an improved prognosis compared to other periampullary tumours. Analysis of survival and prognostic factors are limited due to the low incidence of the carcinoma. The intention of this study in patients with papillary carcinoma was to evaluate short- and long-term survival and to identify prognostic factors for pancreatectomy and reconstruction using pancreatogastrostomy as treatment of carcinoma of Vater's ampulla.

PATIENTS AND METHODS

Between 1989 and 2008 76 patients with a carcinoma of the ampulla of Vater were treated by oncological resection followed by pancreatogastrostomy. Various factors such as demographics, perioperative factors, histopathological findings as well as short- and long-term survival were evaluated retrospectively. Data were analysed statistically using Kaplan-Meier estimates of survival with log-rank test and uni- and multivariate analysis with Cox regression.

RESULTS

The overall 5-year survival was 46 %, the 10-year survival 26 % for resected patients. By univariate analysis we could demonstrate that lymph node metastasis is the only predictor for outcome. In the multivariate analysis, age, sex, grading and especially lymph node status were a significant predictor for the survival of patients.

CONCLUSION

In the current patient cohort lymph node status was the most important independent predictor of outcome after resection of carcinoma of Vater's papilla.

[Implementation of the Perioperative WHO Safety Checklist at a Maximum Care Hospital - A Retrospective Analysis]

BACKGROUND

In recent years there has been a significant increase of surgical procedures worldwide. Perioperative complication occurred in approximately 10 %, mortality was about 0.5 %. Half of these adverse events were considered to have been preventable. With the introduction of a perioperative checklist by the WHO in 2008, a significant reduction of morbidity and mortality could be achieved. The aim of this study was to investigate the success of the implementation process of the checklist at a maximum care hospital over a three-year period and to expose and analyse any occurring issues.

PATIENTS AND METHODS

At various time points (introduction phase, five months, one year and three years after implementation) a total of 358 operations was investigated. First the presence and the handling of the checklist were investigated followed by an analysis of possible influencing factors on the processing. To examine a potential perioperative malpractice, three typical perioperative errors known from the literature on patient safety were analysed.

RESULTS

The presence of the checklist improved significantly during the study. With the exception of the first column (signed by ward nurse) the checklist was processed more often among the participants (anaesthesia nurse, anaesthesia physician, surgeon) over the time. However the "sign out" column edited by the surgeon at the end of the operation fell below expectations. In addition to the duration after implementation the level of experience of the surgeon was a relevant factor for a properly completed checklist. During the study a malpractice was found in two cases, a checklist could not be detected.

CONCLUSION

Within the study we could demonstrate the difficulties of introducing a surgical checklist at a maximum care hospital. Therefore involved nursing or medical staff must be aware of the usefulness of the checklist and should be motivated to use it. In addition, periodical lectures, training courses and role modelling of nursing and medical staff are required. The objective must be to establish the checklist into daily routine as it is a simple and efficient tool to reduce perioperative morbidity and mortality.

[Immunomodulatory aspects in the development, prophylaxis and therapy for postoperative ileus]

Postoperative ileus (POI) is defined as a transient episode of impaired gastrointestinal motility after abdominal surgery, which prevents effective transit of intestinal contents or tolerance of oral intake. This frequent postoperative complication is accompanied by a considerable increase in morbidity and hospitalisation costs. The aetiology of POI is multifactorial. Besides a suppression of peristalsis by inhibitory neuronal signalling and administration of opioids, particularly in the prolonged form, immunological processes play an important role. After surgical trauma, resident macrophages of the muscularis externa (ME) are activated leading to the liberation of proinflammatory mediators and a spreading of the inflammation along the entire gastrointestinal tract. To date, no prophylaxis or evidence-based single approach exists to treat POI. Since none of the current treatment approaches (i.e., prokinetic drug treatment) has provided a benefit in randomised trials, immunoregulatory interventions appear to be more promising in POI prevention or treatment. The present contribution gives an overview of immunological mechanisms leading to POI focusing on current and future therapeutic and prophylactic approaches.

Primary perivascular epitheloid cell tumour (PEComa) of the liver: case report and review of the literature

PURPOSE

Perivascular epitheloid cell tumour [PEComa] is a rare neoplasm entity, characterized by perivascular epitheloid cells with a coexpression of smooth muscle and melanocytic markers. PEComas are found in a variety of localizations, though lesions within the liver are still scarcely found. Although the majority of these tumours are recognized as benign, there are some reports about advanced and aggressive tumours even with fatal outcome. By means of this case report and literary review including other 21 published cases, potential treatment modalities concerning clinical diagnostics, therapy and the follow-up care should be discussed.

METHODS

The following report presents the case of a 53-year old woman with a known liver lesion, since four years under regularly sonographic controls. Finally, after a haemorrhage episode, the lesion was resected and the diagnosis found. For the literary review a systematic search for case reports published between January 1, 1999 and May 1, 2012 was performed on Pubmed.

RESULTS

The only way, till now, of confirming the diagnosis is through immunohistochemical examinations. The already published Malignancy criteria by Folpe et al. must be taken carefully in question, as there are cases of malignant behaviour, that do not exactly coincide with these.

CONCLUSION

Primary PEComa of the liver must be treated as potential malignant and therefore a close follow-up is demanded.

The role of lymphoid tissue in the attenuation of the postoperative ileus

Standardized intestinal manipulation (IM) leads to local bowel wall inflammation subsequently spreading over the entire gastrointestinal tract. Previously, we demonstrated that this so-called gastrointestinal field effect (FE) is immune-mediated. The aim of this study was to investigate the role of secondary lymphoid organs [mesenteric lymph nodes (MLN), gut-associated lymphoid tissue (GALT)] in IM-mediated FE by employing mice with deficient secondary lymphoid organs (aly/aly, MLN ex) or by administration of 2-amino-2-[2-(4-octylphenyl)ethyl]-1,3-propanediol (FTY720), an immunomodulating agent that inhibits emigration of lymphocytes out of lymphoid organs. Small bowel muscularis, and colonic muscularis from wild-type mice as control, from aly/aly mice, FTY720-treated mice (daily dose of 1.0 mg/kg mouse ip starting 3 days before surgical procedure), and wild-type mice that had undergone removal of mesenteric lymph nodes before IM (MLN ex mice) were obtained after selective IM of the jejunum or sham operation. FE was analyzed by measuring transit time of orally administered fluorescent dextran in the gastrointestinal tract [geometric center (GC) of fluorescent dextran], colonic transit time, infiltration of myeloperoxidase-positive cells, and circular smooth muscle contractility. Furthermore, mRNA levels of inflammatory cytokines [interleukin (IL)-6, tumor necrosis factor (TNF)-α, macrophage inflammatory protein (MIP)-1α] were determined by Taqman-PCR. We observed a significantly reduced upregulation of proinflammatory cytokines (IL-6, TNF-α, MIP-1α) in colonic muscularis of MLN ex mice, aly/aly mice, and FTY720-treated mice compared with wild-type mice. Contractility of circular muscularis strips of the colon but not the jejunum was significantly improved in aly/aly mice and FTY720-treated wild-type mice. Additionally, inflammation of the colon determined by the number of myeloperoxidase-positive cells and colonic transit time were significantly improved in aly/aly mice, FTY720-treated wild-type mice, and in MLN ex mice. In summary, lack of secondary lymphoid organs (MLN + GALT) in aly/aly mice or administration of FTY720 abrogated FE after IM as opposed to wild-type mice. These data demonstrate that secondary lymphoid organs are involved in the propagation of FE and postoperative ileus. FTY720 indirectly affects FE by inhibiting migration of activated T cells from the jejunum and adjacent secondary lymphoid organs to the colon. These findings support the crucial role of the adaptive immune system in FE, most likely by a sphyngosine 1-phosphate-dependent mechanism.

Intestinal regeneration, residual function and immunological priming following rescue therapy after rat small bowel transplantation

Clinical evidence suggests that recurrent acute cellular rejection (ACR) may trigger chronic rejection and impair outcome after intestinal transplantation. To test this hypothesis and clarify underlying molecular mechanisms, orthotopic/allogenic intestinal transplantation was performed in rats. ACR was allowed to occur in a MHC-disparate combination (BN-LEW) and two rescue strategies (FK506monotherapy vs. FK506+infliximab) were tested against continuous immunosuppression without ACR, with observation for 7/14 and 21 days after transplantation. Both, FK506 and FK506+infliximab rescue therapy reversed ACR and resulted in improved histology and less cellular infiltration. Proinflammatory cytokines and chemotactic mediators in the muscle layer were significantly reduced in FK506 treated groups. Increased levels of CD4, FOXP3 and IL-17 (mRNA) were observed with infliximab. Contractile function improved significantly after FK506 rescue therapy, with a slight benefit from additional infliximab, but did not reach nontransplanted controls. Fibrosis onset was detected in both rescue groups by Sirius-Red staining with concomitant increase of the fibrogenic mediator VEGF. Recovery from ACR could be attained by both rescue therapy regimens, progressing steadily after initiation of immunosuppression. Reversal of ACR, however, resulted in early stage graft fibrosis. Additional infliximab treatment may enhance physiological recovery of the muscle layer and enteric nervous system independent of inflammatory reactions.

Perioperative infliximab application has marginal effects on ischemia-reperfusion injury in experimental small bowel transplantation in rats

PURPOSE

Ischemia-reperfusion injury leads to impaired smooth muscle function and inflammatory reactions after intestinal transplantation. In previous studies, infliximab has been shown to effectively protect allogenic intestinal grafts in the early phase after transplantation with resulting improved contractility. This study was designed to reveal protective effects of infliximab on ischemia-reperfusion injury in isogenic transplantation.

METHODS

Isogenic, orthotopic small bowel transplantation was performed in Lewis rats (3 h cold ischemia). Five groups were defined: non-transplanted animals with no treatment (group 1), isogenic transplanted animals with vehicle treatment (groups 2/3) or with infliximab treatment (5 mg/kg body weight intravenously, directly after reperfusion; groups 4/5). The treated animals were sacrificed after 3 (group 2/4) or 24 h (group 3/5). Histological and immunohistochemical analysis, TUNEL staining, real-time RT-PCR, and contractility measurements in a standard organ bath were used for determination of ischemia-reperfusion injury.

RESULTS

All transplanted animals showed reduced smooth muscle function, while no significant advantage of infliximab treatment was observed. Reduced infiltration of neutrophils was noted in the early phase in animals treated with infliximab. The structural integrity of the bowel and infiltration of ED1-positive monocytes and macrophages did not improve with infliximab treatment. At 3 h after reperfusion, mRNA expression of interleukin (IL)-6, TNF-α, IL-10, and iNOS and MCP-1 displayed increased activation in the infliximab group.

CONCLUSION

The protective effects of infliximab in the early phase after experimental small bowel transplantation seem to be unrelated to ischemia-reperfusion injury. The promising effects in allogenic transplantation indicate the need for further experiments with infliximab as complementary treatment under standard immunosuppressive therapy. Further experiments should focus on additional infliximab treatment in the setting of acute rejection.

Meloxicam, a COX-2 inhibitor, ameliorates ischemia/reperfusion injury in non-heart-beating donor livers

BACKGROUND/AIMS

Chronic organ donor shortage has led to the consideration to expand the donor pool with livers from non-heart-beating donors (NHBD), although a higher risk of graft dys- or nonfunction is associated with these livers. We examined the effects of selective cyclooxygenase-2 (COX-2) inhibition on hepatic warm ischemia (WI) reperfusion (I/R) injury of NHBD.

METHODS

Male Wistar rats were used as donors and meloxicam (5 mg/kg body weight) was administered into the preservation solution. Livers were excised after 60 min of WI in situ, flushed and preserved for 24 h at 4°C. Reperfusion was carried out in vitro at a constant flow for 45 min. During reperfusion (5, 15, 30 and 45 min), enzyme release of alanine aminotransferase and glutamate lactate dehydrogenase were measured as well as portal venous pressure, bile production and oxygen consumption. The production of malondialdehyde was quantified and TUNEL staining was performed. Quantitative PCR analyzed COX-2 mRNA. COX-2 immunohistochemistry and TxB(2) detection completed the measurements.

RESULTS

Meloxicam treatment led to better functional recovery concerning liver enzyme release, vascular resistance and metabolic activity over time in all animals. Oxidative stress and apoptosis were considerably reduced.

CONCLUSION

Cold storage using meloxicam resulted in significantly better integrity and function of livers retrieved from NHBD. Selective COX-2 inhibition is a new therapeutic approach achieving improved preservation of grafts from NHBD.

Impact of CCR7 on the gastrointestinal field effect

Standardized intestinal manipulation (IM) leads to local bowel wall inflammation subsequently spreading over the entire gastrointestinal tract. Previously, we demonstrated that this so-called gastrointestinal field effect (FE) is immune mediated. This study aimed to investigate the role of CCR7 in IM-induced FE. Since CCR7 is expressed on activated dendritic cells and T cells and is well known to control their migration, we hypothesized that lack of CCR7 reduces or abolishes FE. Small bowel muscularis and colonic muscularis from CCR7(-/-) and wild-type (WT) mice were obtained after IM of the jejunum or sham operation. FE was analyzed by measuring gastrointestinal transit time of orally given fluorescent dextran (geometric center), colonic transit time, infiltration of MPO-positive cells, and circular smooth muscle contractility. Furthermore, mRNA levels of the inflammatory cytokine IL-6 were determined by RT-PCR. The number of dendritic cells and CD3+CD25+ T cells separately isolated from jejunum and colon was determined in mice after IM and sham operation. There was no significant difference in IL-6 mRNA upregulation in colonic muscularis between sham-operated WT and CCR7(-/-) mice after IM. Contractility of circular muscularis strips of the colon was significantly improved in CCR7(-/-) animals following IM and did not vary significantly from sham-operated animals. Additionally, inflammation of the colon determined by the number of MPO-positive cells and colonic transit time was significantly reduced in CCR7(-/-) mice. In contrast, jejunal contractility and jejunal inflammation of transgenic mice did not differ significantly from WT mice after IM. These data are supported by a significant increase of CD3+CD25+ T cells in the colonic muscularis of WT mice after IM, which could not be observed in CCR7(-/-) mice. These data demonstrate that CCR7 is required for FE and postoperative ileus. CCR7 indirectly affects FE by inhibiting migration of activated dendritic cells and of T cells from the jejunum to the colon. These findings support the critical role of the adaptive immune system in FE.

[Cost-effectiveness of hernia repair : IPOM versus open sublay mesh technique]

In comparison to the conventional technique of incisional or umbilical hernia repair with sublay mesh augmentation, incisional hernias in obese patients can be surgically treated with minor surgical trauma by laparoscopic intraperitoneal onlay mesh (IPOM) repair. However, although shortened operation time, hospital stay and faster postoperative reconvalescence might be possible with IPOM repair, the economic calculation including mesh costs is significantly higher. In this study the two operation techniques were compared and the perioperative advantages and disadvantages of both methods were analyzed based on the German diagnosis-related groups (DRG) system.

[Disappearing borders between visceral surgery and interventional endoscopy]

The tremendous increase in medical knowledge over the last decades and technical progress in medicine have caused further professional specialization. Numerous medical fields have evolved through the process of separation from the parent specialization and the traditional distinction between surgical and medical disciplines has been blurred. As a result of this development organ-specific interdisciplinary units have been formed and new partners have united, such as surgeons and gastroenterologists in the field of interventional endoscopy. The fading boundaries brought with them resistance and even resentment and called for a mutual regulation by the professional associations which took place 10 years ago. Nowadays, surgeons and gastroenterologists in Germany are trained in interventional endoscopy and are the foundation of endoscopic interdisciplinary teamwork in emergency care, diagnostics, therapy, complication management and palliative treatment. Technical innovations striving for a minimization of operative trauma like NOTES depend on the cooperation of both fields of expertise. The driving force behind these efforts should be the shared interest in further improvement of patient care at the highest level of individual expertise, patient-oriented process optimization and adequate use of resources.

Perioperative infliximab application ameliorates acute rejection associated inflammation after intestinal transplantation

As we have shown in the past, acute rejection-related TNF-α upregulation in resident macrophages in the tunica muscularis after small bowel transplantation (SBTx) results in local amplification of inflammation, decisively contributing to graft dysmotility. Therefore, the aim of this study is to investigate the effectiveness of the chimeric-monoclonal-anti-TNF-α antibody infliximab as perioperative single shot treatment addressing inflammatory processes during acute rejection early after transplantation. Orthotopic, isogenic and allogenic SBTx was performed in rats (BN-Lewis/BN-BN) with infliximab treatment. Vehicle and IV-immunoglobulin-treated animals served as controls. Animals were sacrificed after 24 and 168 h. Leukocyte infiltration was investigated in muscularis whole mounts by immunohistochemistry, mediator mRNA expression by Real-Time-RT-PCR, apoptosis by TUNEL and smooth muscle contractility in a standard organ bath. Both, infliximab and Sandoglobulin® revealed antiinflammatory effects. Infliximab resulted in significantly less leukocyte infiltration compared to allogenic controls and IV-immunoglobulin, which was accompanied by lower gene expression of MCP-1 (24 h), IFN-γ (168 h) and infiltration of CD8-positive cells. Smooth muscle contractility improved significantly after 24 h compared to all controls in infliximab treated animals accompanied by lower iNOS expression. Perioperative treatment with infliximab is a possible pharmaceutical approach to overcome graft dysmotility early after SBTx.

Secondary surgery subsequent to distal pancreatectomy

BACKGROUND/AIMS

Early revision procedures after pancreatic head resection significantly increase mortality. Due to their complexity, secondary operations at a later stage rank amongst the most demanding surgical procedures. We sought to critically analyze indications and outcome from early revision and subsequent redo procedures following distal pancreatic resection (DPR).

METHODOLOGY

During a 5-year period 53 subsequent patients undergoing DPR were identified from a pancreatic resection database and analyzed regarding indication for and outcome of early revision and late redo procedures.

RESULTS

Six patients (11%) underwent early revision procedures during the same hospital stay. Indications were peritonitis (n = 3), intraabdominal hemorrhage (n = 2) and oncologic re-resection (n = 1). Four patients (7.6%) were readmitted after 192 days (d) on average (range 53 - 538d) and underwent subsequent redo surgery due to occurrence of metastases in 2 cases, and insufficiency of an ascendo-rectostomy and adhesive ileus. Hospital stay and mortality were significantly increased after early revision surgery (40d vs. 18d; 33% vs. 0%). Splenectomy during DPR was carried out in all patients requiring early operative reintervention, compared to 63% in patients without secondary surgery (p < 0.07).

CONCLUSIONS

Early revision surgery following DPR increases postoperative mortality and length of hospital stay. Risk factors were complex injuries (e.g. gun shot wound), concomitant portal hypertension with collateral circulation and splenectomy. Subsequent redo surgery following DPR was performed on average within 7 month following the index operation without mortality and with comparable morbidity. Indications were recurrent malignant disease and complications of the intestine.

Influence of immunosuppression on alloresponse, inflammation and contractile function of graft after intestinal transplantation

In small bowel transplantation (SBTx), graft manipulation, ischemia/reperfusion injury and acute rejection initiate a severe cellular and molecular inflammatory response in the muscularis propria leading to impaired motility of the graft. This study examined and compared the effect of tacrolimus and sirolimus on inflammation in graft muscularis. After allogeneic orthotopic SBTx, recipient rats were treated with tacrolimus or sirolimus. Tacrolimus and sirolimus attenuated neutrophilic, macrophage and T-cell infiltration in graft muscularis, which was associated with reduced apoptotic cell death. Nonspecific inflammatory mediators (IL-6, MCP-1) and T-cell activation markers (IL-2, IFN-gamma) were highly upregulated in allogeneic control graft muscularis 24 h and 7 days after SBTx, and tacrolimus and sirolimus significantly suppressed upregulation of these mediators. In vitro organ bath method demonstrated a severe decrease in graft smooth muscle contractility in allogeneic control (22% of normal control). Correlating with attenuated upregulation of iNOS, tacrolimus and sirolimus treatment significantly improved contractility (64% and 72%, respectively). Although sirolimus reduced cellular and molecular inflammatory response more efficiently after 24 h, contrary tacrolimus prevented acute rejection more efficiently. In conclusion, tacrolimus and sirolimus attenuate cellular and molecular inflammatory response in graft muscularis and subsequent dysmotility of the graft after allogeneic SBTx.

Postresection survival outcomes of pancreatic cancer according to demographic factors and socio-economic status

AIM

Aim of the study was to evaluate the impact of demographic factors (DGF) and socio-economic status (SES) on survival after pancreatic cancer resection in a German setting.

METHODS

Patients with pancreatic adenocarcinoma and pancreaticoduodenectomy were identified from our pancreatic resection database (1989-2008). DGF, SES, survival and tumor-related information were obtained from hospital records, a registry office questionnaire, and telephone interviews with patients, relatives and general practitioners.

RESULTS

Follow-up was completed in 117 patients. Median overall survival and 5-year survival rate was 22 month and 10%, respectively. Survival significantly improved over time with a 16% 5-year survival and a median survival of 27 month for recent patients. The longest survival period with a median of 63 month was observed for patients with AJCC stage I. Tumor-related factors and treatment period, but not SES influenced survival after pancreatic cancer resection in our cohort.

CONCLUSIONS

To our knowledge, this is the first study to explore survival from pancreatic cancer according to DGF and SES in a German setting. Disparities in survival among our patients depend solely on tumor-related factors and treatment period and could not be explained by SES including key factors like income or type of health insurance. The comparable postresection outcome of patients with low and high SES at our department could be in part due to the universal German multi-payer health system, based on compulsory enrolment for the majority, which seems not to support health care inequalities seen in other OECD countries.

Liver transplantation for hilar cholangiocarcinoma: a German survey

BACKGROUND

The present study reports a German survey addressing outcomes in nonselected historical series of liver transplantation (OLT) for hilar cholangiocarcinoma (HL).

PATIENTS AND METHODS

We sent to all 25 German transplant centers performing OLT a survey that addressed (1) the number of OLTs for HL and the period during which they were performed; (2) the incidence of HL diagnosed prior to OLT/rate of incidental HL (for example, in primary sclerosing cholangitis); (3) tumor stages according to Union Internationale Centre le Cancer; (4) patient survival; and (5) tumor recurrence rate.

RESULTS

Eighty percent of centers responded, reporting 47 patients who were transplanted for HL. Tumors were classified as pT2 (25%), pT3 (73%), or pT4 (2%). HL was diagnosed incidentally in 10% of cases. A primary diagnosis of PSC was observed in 16% of patients. Overall median survival was 35.5 months. When in-hospital mortality (n = 12) was excluded, the median survival was 45.4 months, corresponding to 3- and 5-year survival rates of 42% and 31%, versus 31% and 22% when in-hospital mortality was included. HL recurred in 34% of cases. Three- and 5-year survivals for the 15 patients transplanted since 1998 was 57% and 48%, respectively. Median survival ranged from 20 to 42 months based on the time period (P = .014).

CONCLUSIONS

The acceptable overall survival, the improved results after careful patient selection since 1998, and the encouraging outcomes from recent studies all suggest that OLT may be a potential treatment for selected cases of HL. Prospective multicenter randomized studies with strict selection criteria and multimodal treatments seem necessary.

Liver transplantation for hilar cholangiocarcinoma: a German survey

BACKGROUND

The present study reports a German survey addressing outcomes in nonselected historical series of liver transplantation (OLT) for hilar cholangiocarcinoma (HL).

PATIENTS AND METHODS

We sent to all 25 German transplant centers performing OLT a survey that addressed (1) the number of OLTs for HL and the period during which they were performed; (2) the incidence of HL diagnosed prior to OLT/rate of incidental HL (for example, in primary sclerosing cholangitis); (3) tumor stages according to Union Internationale Centre le Cancer; (4) patient survival; and (5) tumor recurrence rate.

RESULTS

Eighty percent of centers responded, reporting 47 patients who were transplanted for HL. Tumors were classified as pT2 (25%), pT3 (73%), or pT4 (2%). HL was diagnosed incidentally in 10% of cases. A primary diagnosis of PSC was observed in 16% of patients. Overall median survival was 35.5 months. When in-hospital mortality (n = 12) was excluded, the median survival was 45.4 months, corresponding to 3- and 5-year survival rates of 42% and 31%, versus 31% and 22% when in-hospital mortality was included. HL recurred in 34% of cases. Three- and 5-year survivals for the 15 patients transplanted since 1998 was 57% and 48%, respectively. Median survival ranged from 20 to 42 months based on the time period (P = .014).

CONCLUSIONS

The acceptable overall survival, the improved results after careful patient selection since 1998, and the encouraging outcomes from recent studies all suggest that OLT may be a potential treatment for selected cases of HL. Prospective multicenter randomized studies with strict selection criteria and multimodal treatments seem necessary.

Course and therapy of acute liver failure

OBJECTIVES AND METHODS

Despite liver transplantation and advances in intensive care medicine fulminant hepatic failure [FHF] remains a life-threatening condition. Actual observations of the clinical course of these patients are rare. Therefore, we analyzed course of disease and survival in all patients treated for FHF at the University of Bonn between 1998 and 2004 and compared it to the patients treated for FHF during 1992-1997.

RESULTS

35 patients were treated for FHF during this period. FHF was viral induced in 13 patients (HBV n = 11, HAV n = 2), toxic in nine, cryptogenic in eleven and autoimmune and hyperthermia in one patient each. According to London- and/or Clichy criteria 16 patients were transplanted. Four of them died during the first year after transplantation due to infectious and hemorrhagic complications. Three patients died without liver-transplantation. All together, 1-year survival was 80%. When compared to patients with FHF analyzed in the period 1992-1997 numbers of patients with FHF in our centre had increased from 16 to 35 patients and 1-year survival improved from 67.5% to 80%. This improved survival was associated with a lower proportion of transplanted patients (45% versus 68%).

CONCLUSIONS

These changes reflect advances in therapy of patients with FHF, which enables a greater proportion of patients to survive without the need for transplantation.

Influence of temporary abdominal wall repair on the intestinal integrity: an experimental study in the rat

BACKGROUND AND AIMS

The aim of this study was to analyze intestinal integrity after temporary abdominal wall repair with absorbable mesh.

METHODS

Rats underwent abdominal wall repair with absorbable mesh or sham operation. Myeloperoxidase-positive cells in the intestinal muscularis were histochemically quantified. Intestinal transit was visualized 48 h after surgery. Local and systemic inflammatory response was measured with TNF-alpha and IL-6 ELISA as well as malondialdehyde (MDA) expression in serum and peritoneal fluid.

RESULTS

Neutrophil count of the intestinal muscularis revealed that infiltration in the mesh-implanted and in the mesh-free animals 48 h postoperatively was similar. Gastrointestinal transit was similarly unaffected 48 h after surgery, with or without mesh implantation. TNF-alpha, IL-6 and MDA concentration in serum and peritoneal fluid showed no significant differences between the two groups.

CONCLUSION

Intestinal contractility and local and systemic inflammatory response remained unaffected. Therefore, absorbable mesh augmentation is a safe and reliable method for temporary repair of the abdominal wall without affecting the intestinal integrity.

Resident macrophages are involved in intestinal transplantation-associated inflammation and motoric dysfunction of the graft muscularis

Gut manipulation and ischemia/reperfusion evoke an inflammatory response within the intestinal muscularis that contributes to dysmotility. We hypothesize that resident macrophages play a key role in initiating the inflammatory cascade. Isogenic small bowel transplantation was performed in Lewis rats. The impact of recovery of organs on muscularis inflammation was investigated by comparing cold whole-body perfusion after versus prior to recovery. The role of macrophages was investigated by transplantation of macrophage-depleted gut. Leukocytes were counted using muscularis whole mounts. Mediator expression was determined by real-time RT-PCR. Contractility was assessed in a standard organ bath. Both organ recovery and ischemia/reperfusion induced leukocyte recruitment and a significant upregulation in IL-6, MCP-1, ICAM-1 and iNOS mRNAs. Although organ recovery in cold ischemia prevented early gene expression, peak expression was not changed by modification of the recovery technique. Compared to controls, transplanted animals showed a 65% decrease in smooth muscle contractility. In contrast, transplanted macrophage-depleted isografts exhibited significant less leukocyte infiltration and only a 19% decrease in contractile activity. In summary, intestinal manipulation during recovery of organs initiates a functionally relevant inflammatory response within the intestinal muscularis that is massively intensified by the ischemia reperfusion injury. Resident muscularis macrophages participate in initiating this inflammatory response.

The role of dendritic cells in the gastrointestinal field effect

INTRODUCTION

Intestinal manipulation leads to local bowel wall inflammation that subsequently spreads over the entire gastrointestinal tract. Previously, this gastrointestinal field effect had been demonstrated by us in a rodent model. We herein postulated an immunologic mechanism mediated by activated leukocytes. The aim of this study was to investigate the activation, maturation and migration of dendritic cells (DC) of the intestinal smooth muscle following surgical trauma and i.p. lipopolysaccharide challenge.

METHODS

Mice underwent standardized intestinal manipulation or iP LPS administration and tissues (intestinal muscularis, Peyer's patches, mesenteric lymph nodes, and spleen) were obtained at various times after manipulation. DC were isolated by tissue digestion and separated by CD11c-iMAG. The harvested DC were analyzed by FACS. The activation pattern of DC was analyzed by polymerase chain reaction.

RESULTS

We found a significant increase in DC within the intestinal muscularis, the Peyer's patches and the mesenteric lymph nodes at 6 and 12 hours following intestinal manipulation and injection of LPS. There was an upregulation of the costimulatory molecules major histocompatibility complex II, CD40, CD80, CD86, and CD205 in the DC after intestinal manipulation. CCR-2, CCR-5, CCR-7, CCL-19, and interleukin-12a were upregulated in a time- and tissue-dependent manner.

CONCLUSION

Intestinal manipulation or LPS challenge induced a recruitment of DC into the muscularis externa and mesenteric lymph nodes combined with an upregulation of costimulatory immunocompetent molecules and migratory surface markers in DCs. These findings demonstrate a precondition for an immunologic response and a possible immunologically mediated gastrointestinal field effect.

Acute Rejection in Allogeneic Rodent Small Bowel Transplantation Causes Smooth Muscle Dysfunction via an Inflammatory Response Within the Intestinal Muscularis

INTRODUCTION

Isogeneic intestinal transplantation elicits an inflammatory response within the intestinal muscularis that is associated with dysmotility. Usually the inflammation and the postoperative motor dysfunction resolve within a few days after small bowel transplantation (SBTx). However, the onset of acute rejection in allogeneic SBTx is again associated with dysmotility. We hypothesized that dysmotility during acute rejection is based on coexpression of kinetically active mediators by the alloreactive leucocyte infiltrate.

MATERIALS AND METHODS

Rat SBTx (BN to Lew and BN to BN) was performed without immunosuppression. Animals were sacrificed at 1, 4, and 7 days after SBTx. Leukocyte infiltration was investigated in muscularis whole mounts by immunohistochemistry. Mediator mRNA expression was determined by reverse transcriptase polymerase chain reaction. Muscle contractility was assessed in a standard organ bath.

RESULTS

Transplanted animals showed a significant inflammatory response within the muscularis at day 1 after SBTx. However, allogeneic transplanted animals exhibited a significant second inflammatory peak at day 7 (mRNA induction: iNOS 150-fold; tumor necrosis factor-alpha 18-fold; interferon-gamma 397-fold), parallel to the onset of rejection. This change was associated with a significant leukocyte infiltration. Compared to controls, allogeneic transplanted animals showed a 29% decrease in smooth muscle contractility on days 1 and 4 and a 71% decrease of contractility on postoperative day 7.

CONCLUSIONS

The motor dysfunction of transplanted small bowel during acute rejection is associated with an inflammatory reaction in the intestinal muscularis. The initial unspecific inflammation process immediately after transplantation is reactivated and intensified during acute rejection.

Mechanism and Impact of Organ Harvesting and Ischemia-Reperfusion Injury Within the Graft Muscularis in Rat Small Bowel Transplantation

INTRODUCTION

Inflammatory events within the gut muscularis contribute to dysmotility. We hypothesized that manipulation during organ harvesting initiated an inflammatory response via muscularis macrophages and that this cascade was amplified during reperfusion.

METHODS

Small bowel transplantation was performed in Lewis rats. To investigate the impact of organ harvesting on muscularis inflammation, cold whole-body perfusion was performed after versus prior to organ harvesting. The role of macrophages was investigated by transplantation of the macrophage-depleted gut. Leukocyte infiltration was investigated in muscularis whole mounts. Mediator mRNA expression was determined by real-time reverse transcriptase polymerase chain reaction. Contractility was assessed in a standard organ bath.

RESULTS

Organ harvesting and ischemia-reperfusion induced leukocyte recruitment and mRNA upregulation in the muscularis: interleukin-6 12217-fold, monocyte chemoattractant protein-1 62-fold, ICAM-1 12-fold, cyclooxygenase-2: 8-fold, iNOS: 150-fold. Although organ harvesting with cold ischemia prevented early gene expression, peak expression at 3-hour reperfusion was not changed by modification of the harvesting technique. Compared to controls, transplanted animals showed a 63% decrease in smooth muscle contractility. In contrast, transplanted macrophage-depleted gut exhibited significantly fewer leukocytes and only a 16% decrease in contractility.

CONCLUSIONS

Gut manipulation during organ harvesting initiates an inflammatory response within the muscularis that is massively intensified during reperfusion. This change contributes to muscular dysfunction. Furthermore, the results suggested that resident macrophages play a key role in initiating this process.

["Fast-track surgery": Perioperative management]

The multimodal therapeutic concept of fast-track surgery is directed against the pathophysiologic functional changes following elective surgery. This concept has been proven to reduce postoperative morbidity and convalescence. This benefit is based on an interdisciplinary approach by surgeons, anaesthesiologists, nurses, and physiotherapy staff to optimise perioperative care in order to decrease surgically-induced stress. Fast-track surgery after elective colorectal surgery has been shown to reduce the rate of postoperative complications and shorten hospital stay significantly. A prerequisite for successfully implementing this concept is the willingness of the participating surgeons to abandon conventional traditions. In addition to abdominal procedures, the basic concept of fast-track surgery has been successfully instituted in other surgical fields, such as urology.

Indocyanine green fluorescence measurement of intestinal transit and gut perfusion after intestinal manipulation

BACKGROUND AND AIMS

Postoperative ileus is a common and poorly understood problem of abdominal surgery. The aim of this study was to measure postoperative intestinal transit and to evaluate bowel wall perfusion by a novel in vivo indocyanine green (ICG)-fluorescence measurement following intestinal manipulation (IM).

METHODS

Rats underwent a simple intestinal manipulation. Myeloperoxidase-positive cells in the muscularis were stained with the Hanker-Yates reaction and quantified histochemically. Bowel wall perfusion was determined directly and 24 h postoperatively using a laser-fluorescence detection unit. Intestinal transit was visualized 24 h after IM.

RESULTS

IM resulted in a massive infiltration (155-fold) of neutrophils into the intestinal muscularis 24 h postoperatively. Bowel wall perfusion significantly decreased directly and 24 h following surgery (29 and 59%, respectively). Gastrointestinal transit was similarly impaired and showed a reduction to 40% of the control values 24 h after IM.

CONCLUSION

IM of the rat small intestine caused an impairment in bowel wall perfusion and microcirculation and a significant decrease in gastrointestinal transit. The ICG fluorescence measurement using the described system proved to be a simple and reliable method to evaluate intestinal transit and bowel wall microcirculation in vivo.

[Liver transplantation in Germany]

As in other western countries the major challenge of liver transplantation in Germany is to expand the number of liver transplantations in respect to the increasing disparity of qualified patients on the waiting list and the still static availability of brain death donor organs. The problem of death on the waiting list has become overt since the German transplantation law has been installed, which has changed the former center-oriented to a patient-oriented allocation weighting waiting time over medical urgency criteria. The more liberal acceptance of so called marginal cadaveric donor livers will probably impair further improvements in the acute and long-term outcome of liver transplantation. This problem can be partially compensated by the use of novel surgical techniques, such as splitting a donor liver to be transplanted into two adult recipients or, more commonly and safe, into an adult and one child. Another alternative to increase the donor pool is living donor liver transplantation, which was first introduced for pediatric recipients but is now increasingly used in adults. In 2001, a constant number of 757 liver transplantations were performed in Germany, including 12.5 % living donor transplantations. Recently, general guidelines for the selection of patients with end-stage liver disease and acute liver failure have been published by the Bundesärztekammer. Additional developments have contributed to improve the results of liver replacement including individualized immunosuppression strategies and novel treatment options to avoid recurrent viral disease following transplantation.

Prostanoid production via COX-2 as a causative mechanism of rodent postoperative ileus

BACKGROUND & AIMS

This study demonstrates a significant role for cyclooxygenase (COX)-2 and prostanoid production as mechanisms for surgically induced postoperative ileus.

METHODS

Rats, COX-2+/+, and COX-2-/- mice underwent simple intestinal manipulation. Reverse-transcription polymerase chain reaction and immunohistochemistry were used to detect and localize COX-2 expression. Prostaglandin levels were measured from serum, peritoneal lavage fluid, and muscularis culture media. Jejunal circular muscle contractions were measured in an organ bath, and gastrointestinal transit was measured in vivo.

RESULTS

The data show that intestinal manipulation induces COX-2 messenger RNA and protein within resident muscularis macrophages, a discrete subpopulation of myenteric neurons and recruited monocytes. The manipulation-induced increase in COX-2 expression resulted in significantly elevated prostaglandin levels within the circulation and peritoneal cavity. The source of these prostanoids could be directly attributed to their release from the inflamed muscularis externa. As a consequence of the molecular up-regulation of COX-2, we observed a decrease in in vitro jejunal circular muscle contractility and gastrointestinal transit, both of which could be alleviated pharmacologically with selective COX-2 inhibition. These studies were corroborated with the use of COX-2-/- mice.

CONCLUSIONS

Prostaglandins, through the induction of COX-2, are major participants in rodent postoperative ileus induced by intestinal manipulation.