[The new continuing education regulations-A challenge for visceral surgery : Results of a survey among DGAV members and solution strategies of the Young Surgeons]

BACKGROUND

The new competency-based further training regulations (nWBO) for surgical training have been adopted by all German state medical associations.

METHODS

From May to June 2023 the Young Surgeons' Working Group (CAJC) conducted an anonymous online survey among the 5896 members of the German Society for General and Visceral Surgery (DGAV).

OBJECTIVE

The survey aimed to assess expectations regarding the nWBO and to develop strategies for enhancing surgical training.

RESULTS

With 488 participants (response rate 8.3%) the study is representative. The respondents consisted of 107 continuing education assistants (WBA 21.9%), 69 specialist physicians, and 188 senior physicians (specialist physicians 14.1% and senior physicians 38.5%), as well as 107 chief physicians (21.9%). The majority worked in regular care providers (44%), followed by maximum care providers (26.8%) and university clinics (20.1%). Only 22% considered the required operative spectrum of the new medical specialist training regulations (nWBO) to be realistic. Half of the respondents believed that full training in their clinic according to the new catalog will no longer be possible and 54.6% considered achieving the target numbers in 6 years to be impossible or state that they can no longer train the same number of continuing education assistants (WBAs) in the same time frame. Endoscopy (17.1-18.8%), fundoplication (15.4-17.7%) and head and neck procedures (12.1-17.1%) were consistently mentioned as bottlenecks across all levels of care. Rotations for balance were reported to be already established or not necessary in 64.7%. In 48% it was stated that the department had established the partial steps concept. The importance of a structured training concept was considered important by 85% of WBAs, compared to 53.3% of chief physicians (CÄ). If a structured training concept was present in the department, the achievability of the target numbers was significantly assessed more positively in the univariate analysis. In the multivariate analysis, male gender and the status of "habilitated/professor" were independent factors for a more positive assessment of the nWBO. Objective certification of training was considered important by 51.5%.

CONCLUSION

Concerns surround the nWBO and the sentiment is pessimistic. Additional requirements and hospital reforms could exacerbate the situation. Collaboration and rotations are crucial but still insufficiently implemented. Quality-oriented certification could enhance the quality of training.

Clinical outcomes and perioperative morbidity and mortality following segmental resections of the colon for Crohn's colitis

INTRODUCTION

Crohn's disease (CD) is a chronic inflammatory bowel disease of a multifactorial pathogenesis. Recently numerous genetic variants linked to an aggressive phenotype were identified, leading to a progress in therapeutic options, resulting in a decreased necessity for surgery. Nevertheless, surgery is often inevitable. The aim of the study was to evaluate possible risk factors for postoperative complications and disease recurrence specifically after colonic resections for CD.

PATIENTS AND METHODS

A total of 241 patients who underwent colonic and ileocaecal resections for CD at our instiution between 2008 and 2018 were included. All data was extracted from clinical charts.

RESULTS

Major complications occurred in 23.8% of all patients. Patients after colonic resections showed a significantly higher rate of major postoperative complications compared to patients after ICR (p =  < 0.0001). The most common complications after colonic resections were postoperative bleeding (22.2%), the need for revision surgery (27.4%) and ICU (17.2%) or hospital readmission (15%). As risk factors for the latter, we identified time interval between admission and surgery (p = 0.015) and the duration of the surgery (p = 0.001). Isolated distal resections had a higher risk for revision surgery and a secondary stoma (p = 0.019). Within the total study population, previous bowel resections (p = 0.037) were identified as independent risk factors for major perioperative complications.

CONCLUSION

The results indicate that both a complex surgical site and a complex surgical procedure lead to a higher perioperative morbidity in colonic resections for Crohn's colitis.

Effect of Surgery on Postoperative Levels of the Gut Homeostasis-Regulating Enzyme Intestinal Alkaline Phosphatase

BACKGROUND

Intestinal homeostasis is a crucial factor for complication-free short- and long-term postoperative recovery. The brush border enzyme intestinal alkaline phosphatase (IAP) is an important regulator of gut barrier function and intestinal homeostasis and prevents endotoxemia by detoxifying lipopolysaccharides (LPSs). As IAP is predominantly secreted by enterocytes in the duodenum, we hypothesized that pancreaticoduodenectomy (PD) leads to a significantly stronger decrease in IAP than other major abdominal surgery.

STUDY DESIGN

Pre- and postoperative blood, stool, and intestinal samples were collected from patients undergoing PD, as well as other major surgical procedures without duodenectomy. The samples were analyzed using enzyme histochemistry, the para -nitrophenyl phosphate method for IAP, and the limulus amebocyte lysate assay for LPS.

RESULTS

Overall, 88 patients were prospectively enrolled in the study. Fecal IAP activity negatively correlated with serum LPS (r = -0.3603, p = 0.0006). PD led to a significant decline in IAP compared to preoperative baseline levels (p < 0.0001). The decline in IAP correlated with the length of proximal small intestinal resection (r = 0.4271, p = 0.0034). Compared to controls, PD was associated with a much more pronounced reduction in IAP-also after adjusting for surgical trauma (operative time, blood loss; r = 0.4598, p = 0.0086). Simultaneously, PD triggered a clearly more prominent increase in serum LPS compared to controls (p = 0.0001). Increased postoperative LPS was associated with an elongated hospitalization (r = 0.7534, p = 0.0062) and more prominent in pancreatic cancer (p = 0.0009).

CONCLUSIONS

Based upon the functional roles for IAP, supplementation with exogenous IAP might be a new treatment option to improve short- and long-term outcome after PD.

Efficacy of four different hemostatic agents in thyroid surgery in reducing the amount of post-operative fluid collection

PURPOSES

Postoperative bleeding remains a life-threatening complication in thyroid surgery. The aim was to assess the efficacy of four different hemostatic agents, Collagen-Fibrinogen-Thrombin Patch (CFTP) in two sizes (3 × 2.5 cm and 9.5 × 4.8 cm), polysaccharide particles (1 g) and Cellulose Gauze (2.5 × 5 cm) on postoperative drainage volume (DV) compared to a control group.

METHODS

We included from October 2007 until Mai 2011, 150 patients (30 per group) for this monocentric, retrospective case-controlled study. Patients were scheduled for a hemithyroidectomy or thyroidectomy. The primary endpoint was the postoperative DV within the first 24 h, secondary the incidence of adverse events.

RESULTS

There were no difference in demographic parameters. The mean DV (± SD) was 51.15 (± 36.86) ml in the control, 50.65 (± 42.79) ml in small (3 × 2.5 cm), 25.38 (± 23.99) ml in large CFTP (9.5 × 4.8 cm), 53.11 (± 39.48) ml in the polysaccharide particles and 48.94 (± 30.59) ml in the cellulose gauze group. DV was significantly reduced with the large CFTP (p < 0.05) compared to all other groups. There were no adverse events.

CONCLUSIONS

We were able to demonstrate a significant reduction in the DV for the large CFTP group compared to the other collectives. Although this as being associated with not inconsiderable costs and we would only recommend its use for high-risk patients only.

Differential Immune Infiltration Profiles in Colitis-Associated Colorectal Cancer versus Sporadic Colorectal Cancer

BACKGROUND

Chronic inflammation is a significant factor in colorectal cancer (CRC) development, especially in colitis-associated CRC (CAC). T-cell exhaustion is known to influence inflammatory bowel disease (IBD) progression and antitumor immunity in IBD patients. This study aimed to identify unique immune infiltration characteristics in CAC patients.

METHODS

We studied 20 CAC and 20 sporadic CRC (sCRC) patients, who were matched by tumor stage, grade, and location. Immunohistochemical staining targeted various T-cell markers (CD3, CD4, CD8, and FOXP3), T-cell exhaustion markers (TOX and TIGIT), a B-cell marker (CD20), and a neutrophil marker (CD66b) in tumor and tumor-free mucosa from both groups. The quantification of the tumor immune stroma algorithm assessed immune-infiltrating cells.

RESULTS

CAC patients had significantly lower TOX+ cell infiltration than sCRC in tumors (p = 0.02) and paracancerous tissues (p < 0.01). Right-sided CAC showed increased infiltration of TOX+ cells (p = 0.01), FOXP3+ regulatory T-cells (p < 0.01), and CD20+ B-cells (p < 0.01) compared to left-sided CAC. In sCRC, higher tumor stages (III and IV) had significantly lower TIGIT+ infiltrate than stages I and II. In CAC, high CD3+ (p < 0.01) and CD20+ (p < 0.01) infiltrates correlated with improved overall survival. In sCRC, better survival was associated with decreased TIGIT+ cells (p < 0.038) and reduced CD8+ infiltrates (p = 0.02).

CONCLUSION

In CAC, high CD3+ and CD20+ infiltrates relate to improved survival, while this association is absent in sCRC. The study revealed marked differences in TIGIT and TOX expression, emphasizing distinctions between CAC and sCRC. T-cell exhaustion appears to have a different role in CAC development.

An immune-related gene prognostic index for predicting prognosis in patients with colorectal cancer

Background

Colorectal cancer (CRC) is one of the most common solid malignant burdens worldwide. Cancer immunology and immunotherapy have become fundamental areas in CRC research and treatment. Currently, the method of generating Immune-Related Gene Prognostic Indices (IRGPIs) has been found to predict patient prognosis as an immune-related prognostic biomarker in a variety of tumors. However, their role in patients with CRC remains mostly unknown. Therefore, we aimed to establish an IRGPI for prognosis evaluation in CRC.

Methods

RNA-sequencing data and clinical information of CRC patients were retrieved from The Cancer Genome Atlas (TCGA) and The Gene Expression Omnibus (GEO) databases as training and validation sets, respectively. Immune-related gene data was obtained from the ImmPort and InnateDB databases. The weighted gene co-expression network analysis (WGCNA) was used to identify hub immune-related genes. An IRGPI was then constructed using Cox regression methods. Based on the median risk score of IRGPI, patients could be divided into high-risk and low-risk groups. To further investigate the immunologic differences, Gene set variation analysis (GSVA) studies were conducted. In addition, immune cell infiltration and related functional analysis were used to identify the differential immune cell subsets and related functional pathways.

Results

We identified 49 immune-related genes associated with the prognosis of CRC, 17 of which were selected for an IRGPI. The IRGPI model significantly differentiates the survival rates of CRC patients in the different groups. The IRGPI as an independent prognostic factor significantly correlates with clinico-pathological factors such as age and tumor stage. Furthermore, we developed a nomogram to improve the clinical utility of the IRGPI score. Immuno-correlation analysis in different IRGPI groups revealed distinct immune cell infiltration (CD4⁺ T cells resting memory) and associated pathways (macrophages, Type I IFNs responses, iDCs.), providing new insights into the tumor microenvironment. At last, drug sensitivity analysis revealed that the high-risk IRGPI group was sensitive to 11 and resistant to 15 drugs.

Conclusion

Our study established a promising immune-related risk model for predicting survival in CRC patients. This could help to better understand the correlation between immunity and the prognosis of CRC providing a new perspective for personalized treatment of CRC.

Molecular characteristics of microsatellite stable early-onset colorectal cancer as predictors of prognosis and immunotherapeutic response

The incidence of early-onset colorectal cancer (EO-CRC, in patients younger than 50) is increasing worldwide. The specific gene signatures in EO-CRC patients are largely unknown. Since EO-CRC with microsatellite instability is frequently associated with Lynch syndrome, we aimed to comprehensively characterize the tumor microenvironment (TME) and gene expression profiles of EO-CRC with microsatellite stable (MSS-EO-CRC). Here, we demonstrated that MSS-EO-CRC has a similar pattern of tumor-infiltrating immune cells, immunotherapeutic responses, consensus molecular subtypes, and prognosis as late-onset CRC with MSS (MSS-LO-CRC). 133 differential expressed genes were identified as unique gene signatures of MSS-EO-CRC. Moreover, we established a risk score, which was positively associated with PD-L1 expression and could reflect both the level of tumor-infiltrating immune cells and the prognosis of MSS-EO-CRC patients. Application of this score on the anti-PD-L1 treatment cohort demonstrated that the low-risk score group has significant therapeutic advantages and clinical benefits. In addition, candidate driver genes were identified in the different-sidedness of MSS-EO-CRC patients. Altogether, MSS-EO-CRC exhibits distinct molecular profiles that differ from MSS-LO-CRC even though they have a similar TME characterization and survival pattern. Our risk score appears to be robust enough to predict prognosis and immunotherapeutic response and therefore could help to optimize the treatment of MSS-EO-CRC.

Smoking as a risk factor for colorectal neoplasms in young individuals? A systematic meta-analysis

BACKGROUND AND AIMS

Early-onset colorectal neoplasms (EoCRN) include both benign and malign colorectal tumors, which occur before the age of 50. The incidence of EoCRN is rising worldwide. Tobacco smoking has previously been proven to be related to the development of various tumor types. However, its relationship with EoCRN is not clearly defined. Hence, we carried out a systematic review and a meta-analysis to evaluate the relationship between smoking status and the risk of EoCRN.

METHODS

A systematic search of PubMed, EMBASE, and Web of Science up to September 7, 2022, was performed for studies that evaluated the association of smoking status with EoCRN. The quality of the case-control study was evaluated with the Newcastle‒Ottawa Scale. The quality of the cross-sectional studies was evaluated with the American Health Care Research and Quality checklist. Fixed-effects models were used to pool odds ratios (ORs) to evaluate the relationship between the risk of developing EoCRN and smoking status. The meta-analyses were performed with Review Manager version 5.4, and funnel plots and publication bias tests were produced by STATA software.

RESULTS

A total of six studies were included in this meta-analysis. After pooling the results of these six studies, we found that current smokers carry a relatively high risk of developing EoCRN (OR, 1.33; 95% confidence interval [CI], 1.17-1.52) compared to never-smokers. Ex-smokers were not at a significantly increased risk for developing EoCRN (OR, 1.00; 95% CI, 0.86-1.18).

DISCUSSION

Smoking behavior is significantly associated with an increased risk for developing EoCRN and might be one of the reasons for the increasing incidence. Ex-smokers who quit are not at significant risk of developing EoCRN.

Gut Barrier Dysfunction and Bacterial Lipopolysaccharides in Colorectal Cancer

BACKGROUND

Inflammation is known to be an essential driver of various types of cancer. An increasing number of studies have suggested that the occurrence and development of colorectal cancer (CRC) are linked to the inflammatory microenvironment of the intestine. This assumption is further supported by the fact that patients with inflammatory bowel disease (IBD) are more likely to develop CRC. Multiple studies in mice and humans have shown that preoperative systemic inflammatory response is predictive of cancer recurrence after potentially curative resection. Lipopolysaccharides (LPS) are membrane surface markers of gram-negative bacteria, which induce gut barrier dysfunction and inflammation and might be significantly involved in the occurrence and development of CRC.

METHODS

A selective literature search was conducted in Medline and PubMed, using the terms "Colorectal Cancer", "Gut Barrier", "Lipopolysaccharides", and "Inflammation".

RESULTS

Disruption of intestinal homeostasis, including gut barrier dysfunction, is linked to increased LPS levels and is a critical factor for chronic inflammation. LPS can activate the diverse nuclear factor-κB (NF-κB) pathway via Toll-like receptors 4 (TLR4) to promote the inflammatory response, which aggravates gut barrier dysfunction and encourages CRC development. An intact gut barrier prevents antigens and bacteria from crossing the intestinal endothelial layer and entering circulation. In contrast, a damaged gut barrier triggers inflammatory responses and increases susceptibility to CRC. Thus, targeting LPS and the gut barrier might be a promising novel therapeutic approach for additional treatment of CRC.

CONCLUSION

Gut barrier dysfuction and bacterial LPS seem to play an important role in the pathogenesis and disease progression of colorectal cancer and therefore require further investigation.

[Expected effects of the new continuing education regulations in general and visceral surgery : Survey among Bavarian surgeons and residents]

INTRODUCTION

The new competency-based continuing education regulations for surgical training (WBO) came into effect in Bavaria in August 2022.

METHODS

From May to July 2022, we conducted an anonymized online survey among Bavarian general and visceral surgeons and surgical residents (ÄiW). The aim was to survey expectations of the effects of the new WBO.

RESULTS

The response rate was 35%. In total data could be collected from 80 persons, 36 ÄiW (45%), 30 specialists and senior physicians (37.5%) and 14 chief physicians (17.5%). The majority of respondents worked at a university hospital (38.8%) or a regular provider (35%). A strengthening of the competence to act through implementation of the new WBO is seen by 41.3% and 55.7% see independent operating under partial supervision by the instructor as a goal. Of the respondents 50% see the required case numbers as not achievable and 55.1% deny reaching them in the expected period of 6 years. About 60% do not expect to be able to train the same number of ÄiWs in the same amount of time. Almost 75% of the respondents state that from their point of view, a good continuing education with the achievement of a solid competence to act would not work without overtime hours. About 44% of the respondents expect that a full surgical training would continue to be possible at their institution.

CONCLUSION

Both among the instructors and among the trainees there is a tendency to fear that realistic training, in particular the achievement of the guideline figures, will no longer be possible in the usual further training time. This necessitates the consistent implementation of structured continuing education with a high degree of transparency in training.

Endoscopic Treatment Options for Gastrointestinal Leaks

Background

Spontaneous or postoperative gastrointestinal defects are still life-threatening complications with elevated morbidity and mortality. Recently, endoscopic treatment options - up and foremost endoscopic vacuum therapy (EVT) - have become increasingly popular and have shown promising results in these patients.

Methods

We performed an electronic systematic search of the MEDLINE databases (PubMed, EMBASE, and Cochrane) and searched for studies evaluating endoscopic options for the treatment of esophageal and colorectal leakages and/or perforations until March 2022.

Results

The closure rate of both esophageal and colorectal defects by EVT is high and even exceeds the results of surgical revision in parts. Out of all endoscopic treatment options, EVT shows most evidence and appears to have the highest therapeutic success rates. Furthermore, EVT for both indications had a low rate of serious complications without relevant in-hospital mortality. In selected patients, EVT can be applied without fecal diversion and transferred to an outpatient setting.

Conclusion

Despite multiple endoscopic treatment options, EVT is increasingly becoming the new gold standard in endoscopic treatment of extraperitoneal defects of the upper and lower GI tract with localized peritonitis or mediastinitis and without close proximity to major blood vessels. However, further prospective, comparative studies are needed to strengthen the current evidence.

Neck Circumference Measurement for Surveillance and Early Detection of Hemorrhage After Thyroidectomy: A Diagnostic Accuracy Study

Importance

Postthyroidectomy hemorrhage is a potentially life-threatening complication with no reliable noninvasive method of early detection.

Objective

To evaluate the diagnostic accuracy of neck circumference measurement for early detection of postoperative hemorrhage after thyroidectomy.

Design, Setting, and Participants

This diagnostic accuracy study at an academic teaching hospital used a prospective cohort of patients undergoing thyroid surgery from November 1, 2015, to January 31, 2018 (group 1), and a retrospective cohort of patients undergoing the same surgery from January 1, 2020, to September 30, 2021 (group 2). We performed repeated perioperative neck circumference measurements to evaluate the association of increased neck circumference with postthyroidectomy hemorrhage among patients at risk for hemorrhage.

Main Outcomes and Measures

The primary end point was the diagnostic value of neck circumference measurement for detection of postthyroidectomy hemorrhage. Additionally, data on demographic information and risk factors for postthyroidectomy hemorrhage were examined. Data analyses were performed from November 1, 2021, to January 5, 2022.

Results

The prospective cohort (group 1) comprised 60 patients (45 [75%] women) with a mean (SD) age of 52.2 (13.5) years; those who experienced a postthyroidectomy hemorrhage had a mean (SD) age of 57.4 (9.0) years. The retrospective cohort (group 2) comprised 353 patients (258 [73%] women) with a mean (SD) age of 55.3 (14.1) years; patients who experienced a postthyroidectomy hemorrhage had a mean (SD) age of 62.2 (10.0) years. In group 1, postoperative neck circumference increased by a median (range) of 5.0 (4.0 to 7.0) cm in patients with hemorrhage, and only 1.0 (-2.5 to 4.0) cm in patients with no postoperative bleeding (difference in the medians, 4.0 cm [95% CI, 3.0 to 5.5 cm]; effect size, 3.74 [95% CI, 2.6 to 4.9]). Defining a 7% or greater increase in neck circumference as the cutoff value for detecting postthyroidectomy hemorrhage showed a diagnostic sensitivity and specificity of 1.0 (95% CI, 0.48 to 1.0) and 0.86 (95% CI, 0.71 to 0.92), respectively. The retrospective validation also showed a difference in median (range) increase of postoperative neck circumference between patients with hemorrhage and those without-3.0 (0 to 6.0) cm vs 0.0 (-6.0 to 5.0) cm (difference in medians, 3.8 cm [95% CI, 3.0 to 4.9]; effect size, 1.63 [95% CI, 0.96 to 2.3]). Considering 12 false-positive and 332 correct-negative results, the diagnostic tool showed a sensitivity of 0.89 (95% CI, 0.51 to 0.99) and a specificity of 0.97 (95% CI, 0.94 to 0.98).

Conclusions and Relevance

The findings of this diagnostic accuracy study suggest that neck circumference measurement is a feasible and easy-to-use diagnostic tool for routine clinical care to detect postthyroidectomy hemorrhage. A 7% or greater increase over the postoperative baseline neck circumference seems to be a reliable threshold for detecting postthyroidectomy hemorrhage. Neck circumference measurement should be used in combination with surveillance of clinical signs and symptoms.

Antibiotic Bowel Decontamination in Gastrointestinal Surgery—A Single-Center 20 Years’ Experience

Objective

Anastomotic leakage, surgical site infections, and other infectious complications are still common complications in gastrointestinal surgery. The concept of perioperative antibiotic bowel decontamination demonstrates beneficial effects in single randomized controlled trials (RCTs), but data from routine clinical use are still sparse. Our aim was to analyze the data from the routine clinical use of perioperative antibiotic bowel decontamination in gastrointestinal surgery.

Methods

Based on 20 years’ experience, we performed a retrospective analysis of all cases in oncologic gastrointestinal surgery with the use of antibiotic bowel decontamination in gastric, sigmoid, and rectal cancer. Clinical data and perioperative outcomes were analyzed, especially regarding anastomotic leakage, surgical site infections, and other infectious complications.

Results

A total of n = 477 cases of gastrointestinal surgery in gastric cancer (n = 80), sigmoid cancer (n = 168), and rectal cancer (n = 229) using a perioperative regimen of antibiotic bowel decontamination could be included in this analysis. Overall, anastomotic leakage occurred in 4.4% (2.5% gastric cancer, 3.0% sigmoid cancer, 6.1% rectal cancer) and surgical site infections in 9.6% (6.3% gastric cancer, 9.5% sigmoid cancer, 10.9% rectal cancer). The incidence of all infectious complications was 13.6% (12.5% gastric cancer, 11.3% sigmoid cancer, 15.7% rectal cancer). Mortality was low, with an overall rate of 1.1% (1.3% gastric cancer, 1.8% sigmoid cancer, 0.4% rectal cancer). Antibiotic decontamination was completed in 98.5%. No adverse effects of antibiotic bowel decontamination could be observed.

Conclusion

Overall, in this large cohort, we can report low rates of surgery-related serious morbidity and mortality when perioperative antibiotic bowel decontamination is performed. The rates are lower than other clinical reports. In our clinical experience, the use of perioperative antibiotic bowel decontamination appears to improve patient safety and surgical outcomes during gastrointestinal oncologic procedures in a routine clinical setting.

It is not NOD2 - genetic and clinical risk factors for postoperative complications following ileocolic resection in Crohn's disease

PURPOSE

To evaluate the role of the nucleotide oligomerization domain 2 (NOD2) mutation status and other risk factors for the incidence of postoperative complications after ileocolic resection for Crohn's disease (CD).

METHODS

Data of 138 patients consecutively undergoing ileocolic resection for CD at a tertiary academic referral center were retrospectively analyzed including single nucleotide polymorphism (SNP) data of the NOD2 gene. Uni- and multivariate regression analysis was performed to identify factors associated with increased risk of severe postoperative complications.

RESULTS

From 114 patients (83%), the NOD2 mutation status was available. Of these, 60 (53%) had a NOD2 wildtype, whereas eleven (10%) were homozygous for the high risk p.Leu1007fsX1008 (rs2066847) variant. Major postoperative complications occurred in 28 patients (20%). Twenty-seven of these (96%) were intraabdominal septic complications such as anastomotic leakage or abscess. Male gender (P = 0.029; OR 3.052, the duration of CD (time [months] from initial diagnosis of CD to surgery; P = 0.001; OR 1.009), previous abdominal surgery for CD (P = 0.017; OR 3.49), and the presence of enteric fistulas (P = 0.023; OR 3.21) were identified as independent risk factors for major postoperative complications. Homozygosity for the NOD2 high-risk variant p.Leu1007fsX1008 did not show increased postoperative morbidity in the short and long-term outcome.

CONCLUSIONS

We could detect independent risk factors for major postoperative complications after ileocolic resection for Crohn's disease. However, patients with the high-risk variant p.Leu1007fsX1008 of the NOD2 gene did not show increased postoperative morbidity.

Oral antibiotic bowel decontamination in open and laparoscopic sigmoid resections for diverticular disease

PURPOSE

There is an ongoing debate on whether or not to use oral antibiotic bowel decontamination in colorectal surgery, despite the numerous different regimens in terms of antibiotic substances and duration of application. As we routinely use oral antibiotic bowel decontamination (selective decontamination of the digestive tract (SDD) regimen and SDD regimen plus vancomycin since 2016) in surgery for diverticular disease, our aim was to retrospectively analyze the perioperative outcome in two independent centers.

METHODS

Data from two centers with a routine use of oral antibiotic bowel decontamination for up to 20 years of experience were analyzed for the perioperative outcome of 384 patients undergoing surgery for diverticular disease.

RESULTS

Overall morbidity was 12.8%, overall mortality was 0.3%, the overall rate of anastomotic leakage (AL) was 1.0%, and surgical site infections (SSIs) were 5.5% and 7.8% of all infectious complications including urinary tract infections and pneumonia. No serious adverse events were related to use of oral antibiotic bowel decontamination. Most of the patients (93.8%) completed the perioperative regimen. Additional use of vancomycin to the SDD regimen did not show a further reduction of infectious complications, including SSI and AL.

CONCLUSION

Oral antibiotic decontamination appears to be safe and effective with low rates of AL and infectious complications in surgery for diverticular disease.

Ustekinumab Inhibits T Follicular Helper Cell Differentiation in Patients With Crohn's Disease

BACKGROUND & AIMS

The pathogenesis of chronic inflammatory bowel diseases (Crohn's disease [CD] and ulcerative colitis) involves dysregulated TH1 and TH17 cell responses, which can be targeted therapeutically by the monoclonal antibody Ustekinumab directed against the joint p40 subunit of IL-12 and IL-23. These cytokines may also regulate the differentiation of T follicular helper (TFH) cells, which promote B cell function in germinal centers. However, the role of TFH cells in CD pathogenesis and impact of Ustekinumab therapy on TFH cell fate in patients are poorly defined.

METHODS

Lymphocytes were isolated from peripheral blood (n=45) and intestinal biopsies (n=15) of CD patients or healthy controls (n=21) and analyzed by flow cytometry to assess TFH cell phenotypes and functions ex vivo. In addition, TFH cell differentiation was analyzed in the presence of Ustekinumab in vitro.

RESULTS

TFH cell frequencies in the intestine as well as peripheral blood were associated with endoscopic as well as biochemical evidence of CD activity. CD patients with clinical response to Ustekinumab, but not those with response to anti-TNF antibodies, displayed reduced frequencies of circulating TFH cells in a concentration-dependent manner while the TFH phenotype was not affected by Ustekinumab therapy. In keeping with this notion, TFH cell differentiation was inhibited by Ustekinumab in vitro while TFH cell maintenance was not affected. Moreover, Ustekinumab therapy resulted in reduced germinal center activity in CD patients in vivo.

CONCLUSIONS

These data implicate TFH cells in the pathogenesis of CD and indicate that Ustekinumab therapy affects TFH cell differentiation, which may influence TFH-mediated immune functions in UST-treated CD patients.

Vitamin D Inhibits Pro-Inflammatory T Cell Function in Patients With Inflammatory Bowel Disease

BACKGROUND AND AIMS

Dysregulated T cell responses contribute to the pathogenesis of inflammatory bowel disease [IBD]. Because vitamin D [vitD] deficiency is a risk factor for adverse disease outcomes, we aimed to characterize the impact of vitD on intestinal and peripheral T cell profiles.

METHODS

T cells were isolated from peripheral blood and intestinal biopsies of IBD patients, incubated with vitD and characterized by flow cytometry. To translate these in vitro findings to the clinic, serum vitD concentrations and clinical outcomes were correlated with T cell phenotype and function in a prospective patient cohort.

RESULTS

Incubation of peripheral and intestinal T cells with 1,25(OH)2-vitD resulted in strongly reduced frequencies of pro-inflammatory CD4+ and CD8+ T cells producing interferon γ [IFNγ], interleukin-17 [IL-17], IL-22, IL-9 and tumour necrosis factor [TNF]. Univariable analysis of 200 IBD patients revealed associations of vitD deficiency with non-compliant vitD intake, season of the year and anaemia in Crohn's disease [CD] as well as disease activity in ulcerative colitis [UC]. Ex vivo immunophenotyping revealed that CD4+ and CD8+ T cell subsets were not substantially altered in vitD-deficient vs vitD-sufficient patients while regulatory T cell frequencies were reduced in UC and non-smoking CD patients with vitD deficiency. However, normalization of serum vitD concentrations in previously deficient CD patients resulted in significantly reduced frequencies of CD4+ T cells producing IFNγ, IL-17 and IL-22.

CONCLUSION

vitD exerts profound anti-inflammatory effects on peripheral and intestinal CD4+ and CD8+ T cells of IBD patients in vitro and inhibits TH1 and TH17 cytokine production in CD patients in vivo.