Machine learning prediction model for postoperative outcome after perforated appendicitis.

PURPOSE: Appendectomy for acute appendicitis is one of the most common operative procedures worldwide in both children and adults. In particular, complicated (perforated) cases show high variability in individual outcomes. Here, we developed and validated a machine learning prediction model for postoperative outcome of perforated appendicitis. METHODS: Retrospective analyses of patients with clinically and histologically verified perforated appendicitis over 10 years were performed. Demographic and surgical baseline characteristics were used as competing predictors of single-patient outcomes along multiple dimensions via a random forest classifier with stratified subsampling. To assess whether complications could be predicted in new, individual cases, the ensuing models were evaluated using a replicated 10-fold cross-validation. RESULTS: A total of 163 patients were included in the study. Sixty-four patients underwent laparoscopic surgery, whereas ninety-nine patients got a primary open procedure. Interval from admission to appendectomy was 9 ± 12 h and duration of the surgery was 74 ± 38 min. Forty-three patients needed intensive care treatment. Overall mortality was 0.6 % and morbidity rate was 15%. Severe complications as assessed by Clavien-Dindo > 3 were predictable in new cases with an accuracy of 68%. Need for ICU stay (> 24 h) could be predicted with an accuracy of 88%, whereas prolonged hospitalization (greater than 7-15 days) was predicted by the model with an accuracy of 76%. CONCLUSION: We demonstrate that complications following surgery, and in particular, health care system-related outcomes like intensive care treatment and extended hospitalization, may be well predicted at the individual level from demographic and surgical baseline characteristics through machine learning approaches.

3D-Printed Replica and Porcine Explants for Pre-Clinical Optimization of Endoscopic Tumor Treatment by Magnetic Targeting.

BACKGROUND: Animal models have limitations in cancer research, especially regarding anatomy-specific questions. An example is the exact endoscopic placement of magnetic field traps for the targeting of therapeutic nanoparticles. Three-dimensional-printed human replicas may be used to overcome these pitfalls. METHODS: We developed a transparent method to fabricate a patient-specific replica, allowing for a broad scope of application. As an example, we then additively manufactured the relevant organs of a patient with locally advanced pancreatic ductal adenocarcinoma. We performed experimental design investigations for a magnetic field trap and explored the best fixation methods on an explanted porcine stomach wall. RESULTS: We describe in detail the eight-step development of a 3D replica from CT data. To guide further users in their decisions, a morphologic box was created. Endoscopies were performed on the replica and the resulting magnetic field was investigated. The best fixation method to hold the magnetic field traps stably in place was the fixation of loops at the stomach wall with endoscopic single-use clips. CONCLUSIONS: Using only open access software, the developed method may be used for a variety of cancer-related research questions. A detailed description of the workflow allows one to produce a 3D replica for research or training purposes at low costs.

Minimally Invasive Thoracoabdominal Esophagectomy Is Superior to Minimally Invasive Gastrectomy in Terms of Health-Related Quality of Life.

Background and Objectives: There are two operative approaches for adenocarcinomas of the esophagogastric junction: thoracoabdominal esophagectomy or transhiatal extended gastrectomy. Both procedures can be performed minimally invasively. Dependent on the exact localization of the tumor, both approaches are feasible. Aim of this study was to compare the health-related quality of life (HRQOL) of patients after minimally invasive esophagectomy (MIE) with patients who underwent minimally invasive gastrectomy (MIG). Methods: All patients who underwent MIE or gastrectomy for malignoma since 2014 were identified from our clinical database. The identified patients were contacted and asked to fill out a quality of life questionnaire (QLQ) for general and gastrointestinal QOL (European Organization for Research and Treatment of Cancer QLQ-C30 and QLQ-OG25). Results: Global HRQOL scores were higher in patients after MIE than after MIG. After MIE, global HRQOL scores were close to the control population. In cancer-specific syndromes, patients after MIE reported lower symptom scores for financial problems, eating, reflux, and eating with others than patients after MIG. Conclusion: In terms of HRQOL, MIE proved superior to MIG in long-term follow-up in this study. Patients after MIE reported a HRQOL close to that of a healthy reference population.

Improved tissue integration of a new elastic intraperitoneal stoma mesh prosthesis.

Parastomal herniation is a frequent complication in colorectal surgery, occurring with a prevalence of 30-80%. The aim of the study was to create a new intraperitoneal colostoma mesh prosthesis (IPST) with enhanced elastic properties made with thermoplastic polyurethane (TPU) monofilaments. We performed open terminal sigmoid colostomies reinforced with either a 10 cm by 10 cm polyvinylidene fluoride (PVDF) or a new TPU/PVDF composite mesh in a total of 10 minipigs. Colostoma was placed paramedian in the left lower abdomen and IPST meshes were fixed intraperitoneal. After 8 weeks, the animals were euthanized after laparoscopic exploration and specimen were explanted for histological investigations. Implantation of a new IPST-mesh with enhanced elastic properties was feasible in a minipig model within an observation period of 8 weeks. Immunohistochemically, Collagen I/III ratio as a marker of tissue integration was significantly higher in TPU-group versus PVDF group (9.4 ± 0.5 vs. 8.1 ± 0.5, p = 0.002) with a significantly lower inflammatory reaction measured by a smaller inner granuloma at mesh-colon interface (17.6 ± 3.3 µm vs. 23 ± 5 µm, p < 0.001). A new TPU/PVDF composite mesh with enhanced elastic properties as IPST was created. Stoma surgery and especially the evaluation of the new stoma mesh prosthesis are feasible with reproducible results in an animal model. Tissue integration expressed by Collagen I/III ratio seems to be improved in comparison to standard-elastic PVDF-IPST meshes.

A new device to prevent fascial retraction in the open abdomen - proof of concept in vivo.

BACKGROUND: An open abdomen is often necessary for survival of patients after peritonitis, compartment syndrome, or in damage control surgery. However, abdominal wall retraction relieves delays and complicates abdominal wall closure. The principle of the newly fascia preserving device (FPD) is the application of anteriorly directed traction on both fascial edges over an external support through a longitudinal beam to relieve increased abdominal pressure and prevent fascial retraction. METHODS: Twelve pigs were randomly divided into two groups. Both groups underwent midline laparotomy under general anesthesia. Group one was treated with the new device, group two served as controls. The tension for closing the abdominal fascia was measured immediately after laparotomy as well as at 24 and 48 h. Vital parameters and ventilation pressure were recorded. Post mortem, all fascial tissues were histologically examined. RESULTS: All pigs demonstrated increases in abdominal circumference. In both groups, forces for closing the abdomen increased over the observation period. Concerning the central closing force after 24 h we saw a significant lower force in the FPD group (14.4 ± 3 N) vs. control group (21.6 ± 5.7 N, p < 0.001). By testing the main effects using an ANOVA analysis we found a significant group related effect concerning closing force and abdominal circumference of the FDP-group vs. control group (p < 0.001; p < 0.001). The placement of the device on chest and pelvis did not influence vital parameters and ventilation pressure. Histologic exam detected no tissue damage. CONCLUSIONS: This trial shows the feasibility to prevent fascial retraction during the open abdomen by using the new device. Thus, it is expected that an earlier closure of the abdominal wall will be possible, and a higher rate of primary closure will be attained.

Improved biocompatibility of profiled sutures through lower macrophages adhesion.

The biocompatibility of a textile implant is determined by various parameters, such as material composition and surface chemistry. However, little is known about the influence of geometry of sutures on biocompatibility. To elucidate this factor we focused on geometry-modification resulting in ultrafine polyethylene terephthalate (UFPET) suture and a snowflake like shaped polyvenylidenfluorid (PVDF) suture. Forty-eight rats were divided into two observation periods. In each rat 3 out of 4 sutures (profiled UFPET, snowflake-like profiled PVDF, reference Prolene and Mersilene suture) were randomly placed into the subcutaneous tissue. Rats were euthanized after 7 and 21 days and samples were explanted. Foreign body granuloma was measured and expression of CD68, TUNEL, Ki-67 and Collagen I/III ratio were determined. The profiled (snowflake) suture showed a significantly smaller FBG in comparison to standard sutures (p < 0.001). Both modified sutures showed a significant lower tissue remodeling by Ki-67 and TUNEL expression (p < 0.03). Furthermore, profiled sutures caused a lower inflammatory reaction expressed in a significant lower amount of CD68 positive macrophages after 21 days (p < 0.001). Modifications of suture geometry alter the foreign body granuloma and the inflammatory reaction. Therefore, profiled sutures might be a promising approach to improve biocompatibility of textile mesh prosthesis. © 2018 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater 107B: 1772-1778, 2019.

Influence of Telomere Length in Hepatocytes on Liver Regeneration after Partial Hepatectomy in Rats.

BACKGROUND: The aim of this study was to investigate telomere length in hepatocytes as a biomarker for liver regeneration after partial hepatectomy (PH) in rats. MATERIALS AND METHODS: Sixty male Wistar rats underwent a 70% PH. One-month-old rats were assigned to group Y (n = 30) and 4-month-old rats were assigned to group O (n = 30). The rats were euthanized, and their livers were then harvested at postoperative day (POD) 1, 2, 3, 4, or 7. Telomere lengths and established parameters for liver regeneration (residual liver weight and levels of proliferating cell nuclear antigen [PCNA], Ki67, and interleukin [IL]-6) were measured. RESULTS: We observed a significant increase in residual liver weight in group Y compared to that in group O (p = 0.001). The levels of Ki67 (p = 0.016), PCNA (p < 0.0001), and IL-6 (p < 0.001) were significantly higher in group Y. Furthermore, the rats in group Y had significantly earlier peak values of Ki67 and PCNA. Telomeres were significantly longer at the time of PH in group Y (p = 0.001). We showed a correlation between telomere length at the day of PH and liver regeneration. Animals with longer telomeres at the time of PH had better liver regeneration (p = 0.015). In group Y, animals with increased liver regeneration (median cut-off: > 122%) did not show any significant difference in telomere length (p = 0.587) compared to rats with regular regeneration (< 122%). However, in the older animals, rats with increased regeneration had significantly longer telomeres (p = 0.019) than rats with regular regeneration. CONCLUSION: Telomere length in rat hepatocytes depends on age, and animals with long telomeres had earlier and better regeneration of healthy liver tissue than rats with short telomeres. Our data confirms that telomere length in rat hepatocytes could be used as a possible predictive marker for liver regeneration, and could help to identify older individuals with a high capacity for hepatic regeneration.

Impact of liver volume and liver function on posthepatectomy liver failure after portal vein embolization- A multivariable cohort analysis.

BACKGROUND: Liver failure remains a life-threatening complication after liver resection, and is difficult to predict preoperatively. This retrospective cohort study evaluated different preoperative factors in regard to their impact on posthepatectomy liver failure (PHLF) after extended liver resection and previous portal vein embolization (PVE). METHODS: Patient characteristics, liver function and liver volumes of patients undergoing PVE and subsequent liver resection were analyzed. Liver function was determined by the LiMAx test (enzymatic capacity of cytochrome P450 1A2). Factors associated with the primary end point PHLF (according to ISGLS definition) were identified through multivariable analysis. Secondary end points were 30-day mortality and morbidity. RESULTS: 95 patients received PVE, of which 64 patients underwent major liver resection. PHLF occurred in 7 patients (11%). Calculated postoperative liver function was significantly lower in patients with PHLF than in patients without PHLF (67 vs. 109 µg/kg/h; p = 0.01). Other factors associated with PHLF by univariable analysis were age, future liver remnant, MELD score, ASA score, renal insufficiency and heart insufficiency. By multivariable analysis, future liver remnant was the only factor significantly associated with PHLF (p = 0.03). Mortality and morbidity rates were 4.7% and 29.7% respectively. CONCLUSION: Future liver remnant is the only preoperative factor with a significant impact on PHLF. Assessment of preoperative liver function may additionally help identify patients at risk for PHLF.

Biocompatibility and biomechanical analysis of elastic TPU threads as new suture material.

High suture tension is one of the causes for many wound-healing problems. Constriction of tissue within the suture loops of nonelastic sutures can lead to cutting of the suture through tissues and necrosis of the tissue within these loops. The use of elastic materials in new suture types could give the material the ability to adapt tension to the tissue requirements and subsequently lead to more vital tissue within its loops. We evaluated the foreign body host response, as indicator of biocompatibility, to a new thermoplastic poly(carbonate) urethane (TPU) synthetic suture material in a rat model compared with standard nonelastic polypropylene (PP) sutures. Tissue samples were collected at 7 and 21 days, and host response was evaluated. Subsequently, suture tension curves of the new elastic sutures for the first 30 min after knotting were recorded in a pig model. The new TPU sutures showed an improved foreign body response when compared with that of PP, with a reduction in the amount of macrophages surrounding the material. Tension experiments showed a superior tension curve for TPU sutures, with a major reduction in peak suture tension when compared with that of standard PP sutures, while still retaining adequate tension after 30 min. © 2015 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 105B: 99-106, 2017.

Influence of gentamicin-coded PVDF suture material on the healing of intestinal anastomosis in a rat model.

PURPOSE: Intestinal anastomosis is a fundamental procedure in general surgery and required to restore intestinal continuity following resection. The aim of this study was to evaluate whether a gentamicin-coated polyvinylidene fluoride (PVDF) suture material has beneficial effect on anastomotic healing. METHODS: Ninety Sprague-Dawley rats were divided into three groups: a PVDF-suture group, a gentamicin-coated PVDF (GPVDF)-suture group and a control group using Maxon® (polyglycolid-co-trimethylene carbonate). For each animal, a colonic anastomosis was performed. Ten animals from each group were sacrificed on postoperative days 3, 5, and 14. Measurements of anastomotic bursting pressure were performed on days 3 and 5. At each time, collagen type I/III ratio, MMP 2 and MMP-9 expression and the proliferation index (Ki67) were analyzed. RESULTS: In total, 90 animals underwent surgery without postoperative complications. Bursting strength in the GPVDF group was significantly elevated on day 5. Immunohistochemistry showed significant increase of the collagen type I/III ratio for PVDF and GPVDF on days 3 and 5. MMP2 was significantly increased for PVDF on days 3 and 5 and for GPVDF on day 5. The analysis of MMP9 revealed significant increase compared to control on day 3 and 5 (GPVDF) as well as on day 5 (PVDF). Staining for Ki67 revealed a significant elevation on postoperative day 3 for the PVDF and the GPVDF group. CONCLUSIONS: The present data shows the feasibility of PVDF as suture material for colonic anastomosis and confirms the ability of gentamicin to increase the stability of colonic anastomosis when used as coating material.

Presurgical assessment of bariatric patients with the Patient Health Questionnaire (PHQ)--a screening of the prevalence of psychosocial comorbidity.

BACKGROUND: Bariatric surgery has gained increasing relevance due to the dramatic rise in morbid obesity prevalence. A sound body of scientific literature demonstrates positive long-term outcome of bariatric surgery in decreasing mental and physical health morbidity. Still, there is a need for a manageable presurgical screening to assess major mental disorders. The aim of this study was to assess the frequency of common psychiatric syndromes in bariatric surgery candidates using a computerized version of the Patient Health Questionnaire (PHQ). METHODS: In a prospective cohort study from August 2009 to July 2011 morbidly obese individuals seeking bariatric treatment were evaluated for mental health disorders using the PHQ (computerized German version). RESULTS: A total of 159 patients were included in this study. The median age of participants was 42 years, the median BMI was 49 kg/m(2). The PHQ revealed a prevalence of 84 % for mental health disorders, 50 % of the participants had three or more mental health disorders. A high somatic symptom burden (46 %), depressive syndromes (62 %) and anxiety disorders (29 %) were the most frequent psychiatric syndromes. The median number of psychiatric syndromes was 3 for women and 1 for men (p = 0.007). No correlation between BMI and a single syndrome or the sum of syndromes was observed. CONCLUSION: 84 % of the patients seeking bariatric treatment were screened positive for at least one mental health disorder. The computerized PHQ with automated reporting appears to be a useful instrument for presurgical assessment of bariatric patients in routine medical settings.

Video-assisted hepatic abscess debridement.

BACKGROUND: Pyogenic liver abscesses are currently treated by either percutaneous computer tomography (CT)-guided drainage or by laparoscopic and a conventional liver resection when conservative treatment fails but may be associated with substantial morbidity and mortality. METHODS: A minimally invasive technique involving debridement of right liver abscesses was employed using a minimally invasive video-assisted hepatic abscess debridement (VAHD) after unsuccessful percutaneous CT-guided drainage. Clinical data, complication rates and outcomes of patients were recorded retrospectively. RESULTS: Between 2011 and 2014, VAHD was performed on 10 patients at two centres with no observed recurrence of a liver abscess. The median age of the patients was 57 years (range 42-78) with a median pre-operative size of a liver abscess of 78 mm (range 40-115). The median operation time was 47 min (range 23-75), and the median postoperative hospital stay was 9 days (range 7-69). One patient developed a subcutaneous abscess that required further surgery. No patient died, and there were no major complications related to the VAHD. CONCLUSIONS: Video-assisted hepatic abscess debridement is a feasible technique that shows promising results for the treatment of a recurrent right liver abscess.

Functional Liver Recovery After Bariatric Surgery--a Prospective Cohort Study with the LiMAx Test.

BACKGROUND: Bariatric surgery provides long-term weight loss and improvement of obesity-associated diseases such as nonalcoholic steatohepatitis (NASH). Histologic improvement of NASH has been reported in some studies after bariatric surgery. This study was designed to assess the liver function in obese patients as well as its recovery after bariatric surgery with a noninvasive test method. METHODS: In a prospective cohort study from October 2011 to May 2014, morbidly obese individuals receiving bariatric surgery were investigated for functional liver recovery (n = 34). Liver function was determined by the LiMAx test (enzymatic capacity of cytochrome P450 1A2) preoperatively, 6 and 12 months postoperatively. Liver biopsy specimens were obtained from 18 participants and classified according to the nonalcoholic fatty liver disease (NAFLD) activity score (NAS). RESULTS: The mean age of participants was 44 years, and the mean body mass index (BMI) was 52 kg/m(2). The mean percent excess BMI loss (%EBMIL) was 53 % after 6 months and 68 % after 1 year. Mean liver function capacity increased significantly from 255 µg/kg/h preoperative to 324 µg/kg/h after 6 months and 342 µg/kg/h after 12 months. A negative correlation was observed between %EBMIL and alteration of liver function capacity in the first 6 months. Finally, the median NAS showed a negative correlation with liver function capacity. CONCLUSIONS: Bariatric surgery leads to a significant functional recovery of the liver. An initial marked weight loss may negatively influence functional liver recovery.

Elastic mesh with thermoplastic polyurethane filaments preserves effective porosity of textile implants.

In hernia surgery, meshes with small pores tend to be filled by fibrous tissue, which reduces their stretchability and causes patient complaints. Because of the inelasticity of current meshes, mechanical strain might cause pores to collapse even in large-pore mesh constructions. In this study, a mesh with elastic thermoplastic polyurethane (TPU) filaments was constructed to prevent pore size changes even under mechanical strain, and its biocompatibility in comparison with polyvinylidene fluoride (PVDF) was evaluated. A mesh was constructed using PVDF with elastic TPU filaments and mechanically tested. After midline laparotomy in 20 rabbits, we placed a 15 cm × 3 cm mesh as inlay in the defect. Animals were randomized to either the TPU or PVDF group. After 7 or 21 days, mesh expansion was measured under pneumoperitoneum, and abdominal walls were explanted for immunohistochemical investigations. In vitro, TPU meshes showed a slight reduction in effective porosity from 46% at tension-free conditions to 26% under longitudinal and to 34% under transverse strain. The nonelastic PVDF meshes showed a marked reduction in effective porosity from 70% to 7% and 52%, respectively. The TPU mesh had a breaking elongation of 101% and a tensile strength of 35 N/cm. In vivo, both meshes achieved healing of the incision without hernial defect. The TPU mesh maintained its elasticity under pneumoperitoneum. The amount of CD68-positive, Ki67-positive, and apoptotic cells was significantly lower in the TPU group after 7 and 21 days. The newly developed TPU mesh shows elasticity, structural stability, and preserved effective porosity under mechanical strain. Immunohistochemistry indicates superior biocompatibility of TPU mesh compared with PVDF after 7 and 21 days.

Laser-induced drug release for local tumor control--a proof of concept.

BACKGROUND: The systemic palliative chemotherapy of locally extended gastrointestinal and hepatobiliary tumors is associated with a considerable burden for the patient. The aim of this project was to develop a new drug release system to improve the local stent therapy in these patients as a proof of concept study. For this purpose, polymer filaments were modified with drug-loaded polymer microgels that allow selective release of the active substance by photochemical triggering using laser radiation. Integrated into a stent system, the better local tumor control could thus contribute to a significant increase in the quality of life of patients. METHODS: A standard mammalian cell line and two carcinoma cell lines were established. By Fluorescence activated cell sorting (FACS), the cytotoxicity of the different materials was determined in vitro before and after drug loading with the chemotherapeutic agent 5-Fluorouracil (5-FU). For this purpose, the locally applied 5-FU concentration was previously determined by Bromdesoxyuridin assay. 5-FU dimer was synthesized by photo-induced dimerization of 5-FU in the presence of benzophenone in methanol. The chemical structure of 5-FU dimer was confirmed with Hydrogen-1 nuclear magnetic resonance and Fluorine-19 nuclear magnetic resonance. 5-FU dimer is nonsoluble in water and can be easily incorporated in polymer microgels modified with hydrophobic binding domains (cyclodextrin). After laser irradiation, 5-FU dimer decomposes and 5-FU can be released from microgels. Finally, the measurements were repeated after this laser-induced drug release. RESULTS: In FACS analysis, neither the microgels nor the microgel cumarin complexes showed a significant difference in comparison with the negative control with H2O and therefore no toxic effect on the cell lines. After loading with the 5-FU dimer, there was no significant cell death (contrary to the pure 5-FU monomer, which dose had been previously tested as highly toxic). After laser-induced dissociation back to monomer and the associated drug release, FACS analysis showed cytotoxicity. CONCLUSIONS: It was possible to develop 5-FU dimerloaded microgels, which show no cytotoxic effect on cell lines before laser irradiation. After dissociation back to 5-FU monomer by selective photochemical triggering using laser irradiation, the active substance was released. Thus, a new drug release system has been created and tested in vitro. For further development, integration into a stent system and for in vivo follow-up evaluation more studies need to be conducted.

Influence of CD68+ macrophages and neutrophils on anastomotic healing following laparoscopic sigmoid resection due to diverticulitis.

BACKGROUND: The aim of this prospective study was to evaluate the predictive value of a potential preexisting low-grade inflammation regarding the incidence of anastomotic leakage in elective laparoscopic sigmoid resection due to diverticulitis. METHODS: Patients with either chronically recurrent diverticulitis or sigmoid stenosis caused by chronic diverticulitis were included in this study. All patients with acute local or systemic inflammation were excluded. Detailed patient information (e.g. American Society of Anesthesiologists (ASA) grade, comorbidities, duration of hospital stay, and anastomotic leakage) was prospectively recorded. CD68(+) macrophages, neutrophils, CD3(+) T-lymphocytes, CD11c(+) dendritic cells, MHCII, TNFR1, and NF-κB were evaluated by immunohistochemistry within the acquired sample of colonic bowel wall tissue. Clinical and immunohistochemical data was compared between groups (leakage vs. no leakage). Additionally, a matched-pair analysis was performed due to the widely heterogeneous groups concerning the number of patients and to minimize the effect of extraneous variables. RESULTS: A total of 83 patients were included in the study, of which 7 patients suffered an anastomotic leakage. Neither the clinical nor the immunohistochemical parameters were significantly different between the groups. The matched-pair analysis revealed a nonsignificant increase in mean duration of hospital stay for the group with anastomotic leakage and a significantly higher percentage of CD68(+) macrophages and neutrophils in the colonic wall obtained at the index operation in both the mucosal and submucosal layers for the leakage group. CONCLUSIONS: A preexisting low-grade inflammation represented by infiltrates of macrophages and neutrophils is a predictor for increased risk of developing colon anastomotic leakage.

Influence of 4% icodextrin solution on peritoneal tissue response and adhesion formation.

BACKGROUND: Postoperative peritoneal adhesion formation following abdominal surgery remains a relevant surgical problem. The application of soluble physico-chemical barriers like 4% icodextrin is one approach to protect the peritoneal surface from getting linked to adhesive scar. The aim of this study was to investigate the influence of 4% icodextrin on peritoneal tissue response both of visceral and parietal peritoneum, adhesion formation and wound healing. METHODS: 40 rats were divided into two groups. After creation of an intraabdominal defect, either 4% icodextrin (Adept®) or sodium chloride was applied. Animals were sacrificed after 7 and 21 days. Adhesions were scored by an adhesion score. Furthermore, immunohistochemical investigations were conducted to determine the discrete influence of icodextrin on the parietal and visceral peritoneal tissue responses (CD68+ macrophages, CD3+ T-lymphocytes, vimentin for mesenchymal cells, HBME-1 for mesothelial cells, and as components of wound healing COX-2, C-myc, catenin). RESULTS: Postoperative peritoneal adhesions were predominantly present in the sodium chloride group as compared to the icodextrin group (14/19 (74%) vs. 9/19 (47%); p = 0.048). The adhesion score however did not reveal any significant differences, (p = 0.614). Furthermore, the expression of vimentin in both the parietal and visceral peritoneum after 21 days was significantly lower in the icodextrin group than in the sodium chloride group (p = 0.038 and p = 0.028, respectively). No significant differences were observed for macrophages, lymphocytes, reperitonealisation or the expression of COX-2, C-myc or Catenin. CONCLUSIONS: The intraperitoneal application of 4% icodextrin reduces adhesion formation in comparison to sodium chloride. 4% icodextrin solution reduces the inflammatory and mesenchymal infiltrate in the wounded area, thus improving the ratio of mesothel cells to mesenchymal infiltrate. As demonstrated, icodextrin is able to ameliorate the local tissue response. Further experimental studies would be done to elaborate the impact on the early response of the adaptive immune system, which may then trigger the subsequent wound healing and tissue repair.

Comparison of intestinal microcirculation and wound healing in a rat model.

PURPOSE: If a colonic or small bowel lesion is not accessible for endoscopic mucosal resection, enterotomy is a possible although rarely performed surgical technique. It has never been compared to circular anastomosis regarding leakage rate, bowel wall perfusion, and wound healing. Thus, the aim of this basic experimental scientific study was to investigate perianastomotic microcirculation and wound healing. METHODS: Forty rats were divided into four groups (1 jejunal anastomosis, 2 jejunal enterotomy, 3 colonic anastomosis, and 4 colonic enterotomy). Following anastomosis and enterotomy, the intestinal perfusion was measured using laser fluorescence angiography (IC-View). On postoperative day 7, the surface of the mucosal villi, expression of matrix metalloproteinases (MMP) 2, 8, 9, and 13, and the number of proliferating cells (Ki67) as well as the collagen types I/III ratio were analyzed. RESULTS: The perianastomotic microperfusion was significantly reduced in all groups compared to the reference region. The perianastomotic perfusion index was significantly reduced in group 1 compared with group 2, whereas the perfusion index in group 3 was slightly but not significantly reduced in comparison to group 4. Ki67 was elevated in both circular anastomosis groups. Surface of the mucosal villi, MMP expression, and collagen type I/III ratio revealed no significant differences. CONCLUSIONS: Our study affirms the theoretical consideration of a better microperfusion of the bowel wall following an antimesenterial enterotomy and demonstrates that enterotomy is not inferior compared to circular anastomosis. Even though enterotomy is a rarely used surgical technique, it should be regarded as a possible alternative in particular situations.

Intrathoracic versus cervical anastomosis after resection of esophageal cancer: a matched pair analysis of 72 patients in a single center study.

BACKGROUND: The aim of this study was to analyze the early postoperative outcome of esophageal cancer treated by subtotal esophageal resection, gastric interposition and either intrathoracic or cervical anastomosis in a single center study. METHODS: 72 patients who received either a cervical or intrathoracic anastomosis after esophageal resection for esophageal cancer were matched by age and tumor stage. Collected data from these patients were analyzed retrospectively regarding morbidity and mortality rates. RESULTS: Anastomotic leakage rate was significantly lower in the intrathoracic anastomosis group than in the cervical anastomosis group (4 of 36 patients (11%) vs. 11 of 36 patients (31%); p = 0.040). The hospital stay was significantly shorter in the intrathoracic anastomosis group compared to the cervical anastomosis group (14 (range 10-110) vs. 26 days (range 12 - 105); p = 0.012). Wound infection and temporary paresis of the recurrent laryngeal nerve occurred significantly more often in the cervical anastomosis group compared to the intrathoracic anastomosis group (28% vs. 0%; p = 0.002 and 11% vs. 0%; p = 0.046). The overall In-hospital mortality rate was 6% (4 of 72 patients) without any differences between the study groups. CONCLUSIONS: The present data support the assumption that the transthoracic approach with an intrathoracic anastomosis compared to a cervical esophagogastrostomy is the safer and more beneficial procedure in patients with carcinoma of the lower and middle third of the esophagus due to a significant reduction of anastomotic leakage, wound infection, paresis of the recurrent laryngeal nerve and shorter hospital stay.

Extended distal pancreatectomy with en bloc resection of the celiac axis for locally advanced pancreatic cancer: a case report and review of the literature.

Due to a lack of early symptoms, pancreatic cancers of the body and tail are discovered mostly at advanced stages. These locally advanced cancers often involve the celiac axis or the common hepatic artery and are therefore declared unresectable. The extended distal pancreatectomy with en bloc resection of the celiac artery may offer a chance of complete resection. We present the case of a 48-year-old female with pancreatic body cancer invading the celiac axis. The patient underwent laparoscopy to exclude hepatic and peritoneal metastasis. Subsequently, a selective embolization of the common hepatic artery was performed to enlarge arterial flow to the hepatobiliary system and the stomach via the pancreatoduodenal arcades from the superior mesenteric artery. Fifteen days after embolization, the extended distal pancreatectomy with splenectomy and en bloc resection of the celiac axis was carried out. The postoperative course was uneventful, and complete tumor resection was achieved. This case report and a review of the literature show the feasibility and safety of the extended distal pancreatectomy with en bloc resection of the celiac axis. A preoperative embolization of the celiac axis may avoid ischemia-related complications of the stomach or the liver.