Closed Incision Negative Pressure Therapy Reduces Surgical Site Infections in Vascular Surgery: A Prospective Randomised Trial (AIMS Trial).

BACKGROUND: Surgical site infections (SSIs) of the groin remain a crucial problem in vascular surgery, prompting great interest in preventative techniques, such as closed incision negative pressure therapy (ciNPT). This prospective randomised study aimed to assess the potential benefits of ciNPT application after groin incisions for vascular surgery. METHOD: The study included 204 patients who underwent vascular surgery for peripheral artery disease (PAD) at two sites between July 2015 and May 2017. These patients received post-operative treatment with ciNPT (intervention group) or standard wound dressings (control group). After exclusion, 188 patients were assessed for SSIs using the Szilagyi classification. RESULTS: The mean patient age was 66.6 ± 9.4 years (range 43-85 years), and 70% were male (n = 132). Regarding PAD stage, 52% were stage IIB, 28% stage III, and 19% stage IV. Among the patients, 45% (n = 85) had had a previous groin incision. Bacterial swabs were performed in each case of suspected SSI (22.8% [43/188]), while 76.7% (33/188) were negative, there were 5% [5/98] positive swabs in the intervention group and 5.5% [5/90] in the control group). Antibiotics were given to 13.2% of the intervention group, and 31.1% of the control group (p = .004). The control group experienced more frequent SSIs (33.3%; 30/90) than the intervention group (13.2%; 13/98; p = .0015; absolute risk difference -20.1 per 100; 95% CI -31.9 to 8.2). This difference was based on an increased rate of Szilagyi I SSI in the control group (24.6% vs. 8.1%, p = .0012). CONCLUSION: The results confirmed a reduced superficial SSI rate after vascular surgical groin incision using ciNPT compared with standard wound dressings.

Assessment of a course of realistic surgical training during medical education as a tool for pre-residential surgical training.

BACKGROUND: In recent years the focus on practical skills in the German curriculum of medical school has increased greatly. In this study we evaluate the value of a practical surgery course for medical students as a tool for surgical education, as a way of enhancing interest in surgical fields, and as a method of influencing medical students to subsequently choose a surgical career. METHODS: The "Feel like a surgeon"-course is an optional practical surgery course in which topographical anatomy and realistic surgical training using fresh human cadavers are combined for medical students of the RWTH Aachen University. Between 2010 and 2015 every student completed a survey before starting and after completing our course, and in 2015 a follow-up was performed. Using a standardized questionnaire, course quality, learning success and impact on post-instructional career and choice of profession was evaluated. RESULTS: In total, 82 students attended our course between 2010 and 2015 and took part in the evaluation. Evaluation of the course was positive overall, with an average grade of 1.4° ± °0.50. Significant improvement of basic, as well as more complex surgical skills and theoretical knowledge was noted. Furthermore, self-confidence for patient related assignments improved as well. In the follow-up evaluation, a high level of recommendation for surgical residents was seen, as was a high influence of the course on our students' career choice, although no significant change in career plans before and after taking the course was noted. CONCLUSIONS: Our results indicate that a practical surgical course can be a valuable tool to prepare students for a surgical residency and to improve their practical skills generally.

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.

Mesh biocompatibility: effects of cellular inflammation and tissue remodelling.

Mesh biocompatibility is basically determined by the foreign body reaction (FBR). In contrast to physiological wound healing and scar formation, the FBR at the host-tissue/biomaterial interface is present for the lifetime of the medical device. The cellular interactions at the mesh/tissue interface proceed over time ending up in a chronic inflammatory process. The time course of the FBR has been studied extensively and consists of three crucial steps that are protein absorption, cell recruitment and, finally, fibrotic encapsulation and extracellular matrix formation. Each of these steps involves a complex cascade of immune modulators including soluble mediators and various cell types. Recent research has focused on the cellular and molecular interactions of the distinct phases of the FBR offering a new basis for therapeutical strategies. The highly dynamic process of the FBR is considerably influenced by the biomaterial composition. Modifications of the type of polymer, the material weight, the filament structure and the pore size are realized and have substantial effects on the in vivo biocompatibility. Moreover, modern mesh technology aims to utilize the available implants as carrier systems for bioactive drugs. Studies in animal models account for the efficiency of these drugs that aim to reduce mesh-related infections or to minimize FBR by influencing inflammation or extracellular matrix remodelling. A thorough understanding of the molecular mechanisms of FBR provides a sophisticated background for the development of new biomaterials at least as carrier systems for bioactive reagents to reduce inflammation and to improve clinical outcome.

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.

Gentamicin supplemented polyvinylidenfluoride mesh materials enhance tissue integration due to a transcriptionally reduced MMP-2 protein expression.

BACKGROUND: A beneficial effect of gentamicin supplemented mesh material on tissue integration is known. To further elucidate the interaction of collagen and MMP-2 in chronic foreign body reaction and to determine the significance of the MMP-2-specific regulatory element (RE-1) that is known to mediate 80% of the MMP-2 promoter activity, the spatial and temporal transcriptional regulation of the MMP-2 gene was analyzed at the cellular level. METHODS: A PVDF mesh material was surface modified by plasma-induced graft polymerization of acrylic acid (PVDF+PAAc). Three different gentamicin concentrations were bound to the provided active sites of the grafted mesh surfaces (2, 5 and 8 µg/mg). 75 male transgenic MMP-2/LacZ mice harbouring the LacZ reporter gene under control of MMP-2 regulatory sequence -1241/+423, excluding the RE-1 were randomized to five groups. Bilateral of the abdominal midline one of the five different meshes was implanted subcutaneously in each animal. MMP-2 gene transcription (anti-ß-galactosidase staining) and MMP-2 protein expression (anti-MMP-2 staining) were analyzed semiquantitatively by immunohistochemistry 7, 21 and 90 days after mesh implantation. The collagen type I/III ratio was analyzed by cross polarization microscopy to determine the quality of mesh integration. RESULTS: The perifilamentary ß-galactosidase expression as well as the collagen type I/III ratio increased up to the 90th day for all mesh modifications, whereas no significant changes could be observed for MMP-2 protein expression between days 21 and 90. Both the 5 and 8 µg/mg gentamicin group showed significantly reduced levels of ß-galactosidase expression and MMP-2 positive stained cells when compared to the PVDF group on day 7, 21 and 90 respectively (5 µg/mg: p < 0.05 each; 8 µg/mg: p < 0.05 each). Though the type I/III collagen ratio increased over time for all mesh modifications significant differences to the PVDF mesh were only detected for the 8 µg/mg group at all 3 time points (p < 0.05 each). CONCLUSIONS: Our current data indicate that lack of RE-1 is correlated with increased mesh induced MMP-2-gene expression for coated as well as for non-coated mesh materials. Gentamicin coating reduced MMP-2 transcription and protein expression. For the 8 µg/mg group this effect is associated with an increased type I/III collagen ratio. These findings suggest that gentamicin is beneficial for tissue integration after mesh implantation, which possibly is mediated via RE-1.

Severe gastric variceal haemorrhage due to splenic artery thrombosis and consecutive arterial bypass.

BACKGROUND: Upper gastrointestinal haemorrhage is mainly caused by ulcers. Gastric varicosis due to portal hypertension can also be held responsible for upper gastrointestinal bleeding. Portal hypertension causes the development of a collateral circulation from the portal to the caval venous system resulting in development of oesophageal and gastric fundus varices. Those may also be held responsible for upper gastrointestinal haemorrhage. CASE PRESENTATION: In this study, we describe the case of a 69-year-old male with recurrent severe upper gastrointestinal bleeding caused by arterial submucosal collaterals due to idiopathic splenic artery thrombosis. The diagnosis was secured using endoscopic duplex ultrasound and angiography. The patient was successfully treated with a laparoscopic splenectomy and complete dissection of the short gastric arteries, resulting in the collapse of the submucosal arteries in the gastric wall. Follow-up gastroscopy was performed on the 12th postoperative week and showed no signs of bleeding and a significant reduction in the arterial blood flow within the gastric wall. Subsequent follow-up after 6 months also showed no further gastrointestinal bleeding as well as subjective good quality of life for the patient. CONCLUSION: Submucosal arterial collaterals must be excluded by endosonography via endoscopy in case of recurrent upper gastrointestinal bleeding. Laparoscopic splenectomy provides adequate treatment in preventing any recurrent bleeding, if gastric arterial collaterals are caused by splenic artery thrombosis.

Fulminant Epstein-Barr virus - infectious mononucleosis in an adult with liver failure, splenic rupture, and spontaneous esophageal bleeding with ensuing esophageal necrosis: a case report.

INTRODUCTION: Infectious mononucleosis is a clinical syndrome most commonly associated with primary Epstein-Barr virus infection. The majority of patients with infectious mononucleosis recovers without apparent sequelae. However, infectious mononucleosis may be associated with several acute complications. In this report we present a rare case of esophageal rupture that has never been described in the literature before. CASE PRESENTATION: We present the case of an 18-year-old Caucasian man affected by severe infectious mononucleosis complicated by fulminant hepatic failure, splenic rupture and esophageal necrosis. CONCLUSIONS: Although primary Epstein-Barr virus infection is rarely fatal, fulminant infection may occur - in this case leading to hepatic failure, splenic rupture and esophageal necrosis, subsequently making several surgical interventions necessary. We show here that infectious mononucleosis is not only a strictly medical condition, but can also lead to severe surgical complications.

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.

Biocompatibility of prosthetic meshes in abdominal surgery.

Surgical meshes today represent a group of implants mainly used for hernia repair. Modern hernia surgery is no longer imaginable without the application of these special biomaterials leading to millions of implantations each year worldwide. Because clinical trials are insufficient to evaluate the distinct effects of modified mesh materials in regard to tissue biocompatibility and functionality, a basic understanding of the physicochemical properties of mesh materials, as well as the underlying cause for hernia formation, is essential for a rational selection of the most appropriate device. The most important properties of meshes were found to be the type of filament, tensile strength, and experimental data, which indicate that particularly the mesh's porosity is of outstanding importance.