Prediction of post-hepatectomy liver failure by preoperative gadoxetate disodium-enhanced magnetic resonance imaging

BACKGROUND

Approximately 15% of patients experience post-hepatectomy liver failure after major hepatectomy. Poor hepatocyte uptake of gadoxetate disodium, a magnetic resonance imaging contrast agent, may be a predictor of post-hepatectomy liver failure.

METHODS

A retrospective cohort study of patients undergoing major hepatectomy (≥3 segments) with a preoperative gadoxetate disodium-enhanced magnetic resonance imaging was conducted. The liver signal intensity (standardized to the spleen) and the functional liver remnant was calculated to determine if this can predict post-hepatectomy liver failure after major hepatectomy.

RESULTS

In 134 patients, low signal intensity of the remnant liver standardized by signal intensity of the spleen in post-contrast images was associated with post-hepatectomy liver failure in multiple logistic regression analysis (Odds Ratio 0.112; 95% CI 0.023-0.551). In a subgroup of 33 patients with lower quartile of functional liver remnant, area under the curve analysis demonstrated a diagnostic accuracy of functional liver remnant to predict post-hepatectomy liver failure of 0.857 with a cut-off value for functional liver remnant of 1.4985 with 80.0% sensitivity and 89.3% specificity.

CONCLUSION

Functional liver remnant determined by gadoxetate disodium-enhanced magnetic resonance imaging is a predictor of post-hepatectomy liver failure which may help identify patients for resection, reducing morbidity and mortality.

Standardized digital solution with surgical procedure manager (SPM®)-an opportunity for maximizing patient safety and efficiency in ileostomy reversal?

Background

Standardization and digitalization are getting more and more essential in surgery. Surgical procedure manager (SPM®) is a freestanding computer serving as a digital supporter in the operating room. SPM® navigates step-by-step through surgery by providing a checklist for each individual step.

Methods

This was a single center, retrospective study at the Department for General and Visceral Surgery at Charité-Universitätsmedizin Berlin, Campus Benjamin Franklin. Patients who underwent ileostomy reversal without SPM® in the period of January 2017 until December 2017 were compared to patients who were operated with SPM® in the period of June 2018 until July 2020. Explorative analysis and multiple logistic regression were performed.

Results

Overall, 214 patients underwent ileostomy reversal: 95 patients without SPM® vs. 119 patients with SPM®. Ileostomy reversal was performed by head of department/attendings in 34.1%, by fellows in 28.5% and by residents in 37.4%; p = 0.91. Postoperative intraabdominal abscess emerged more often in patients without SPM®: ten (10.5%) patients vs. four (3.4%) patients; p = 0.035. Multiple logistic regression showed a risk reduction for intraabdominal abscess {Odds ratio (OR) 0.19 [95% confidence interval (CI) 0.05-0.71]; p = 0.014} and for bowel perforation [OR 0.09 (95% CI 0.01-0.93); p = 0.043] in the group with use of SPM® in ileostomy reversal.

Conclusions

SPM® may reduce postoperative complications in ileostomy reversal such as intraabdominal abscess and bowel perforation. SPM® may contribute to patient safety.

Influence of the COVID-19 pandemic on the timing of surgical triage, tumor stage, and therapy of patients with colon carcinoma

PURPOSE

With the onset of the COVID pandemic in Germany in March 2020, far-reaching restrictions were imposed that limited medical access for patients. Screening examinations such as colonoscopies were greatly reduced in number. As rapid surgical triage after diagnosis is prognostic, our hypothesis was that pandemic-related delays would increase the proportion of advanced colon cancers with an overall sicker patient population.

METHODS

A total of 204 patients with initial diagnosis of colon cancer were analyzed in this retrospective single-center study between 03/01/2018 and 03/01/2022. Control group (111 patients, pre-COVID-19) and the study group (93 patients, during COVID-19) were compared in terms of tumor stages, surgical therapy, complications, and delays in the clinical setting. The data were presented either as absolute numbers or as median for constant data.

RESULTS

A trend towards more advanced tumor stages (T4a p = 0.067) and a significant increase of emergency surgeries (p = 0.016) with higher rates of ileus and perforation (p = 0.004) as well as discontinuity resections (p = 0.049) during the pandemic could be observed. Delays in surgical triage after endoscopic diagnosis were seen during the 2nd lockdown (02/11/20-26/12/20; p = 0.031).

CONCLUSION

In summary, the results suggest delayed treatment during the COVID-19 pandemic, with the infection pattern of COVID appearing to have a major impact on the time between endoscopic diagnosis and surgical triage/surgery. Adequate care of colon cancer patients is possible even during a pandemic, but it is important to focus on structured screening and tight diagnosis to treatment schedules in order to prevent secondary pandemic victims.

The Value of Indocyanine Green Image-Guided Surgery in Patients with Primary Liver Tumors and Liver Metastases

INTRODUCTION

Successful R0 resection is crucial for the survival of patients with primary liver cancer (PLC) or liver metastases. Up to date, surgical resection lacks a sensitive, real-time intraoperative imaging modality to determine R0 resection. Real-time intraoperative visualization with near-infrared light fluorescence (NIRF) using indocyanine green (ICG) may have the potential to meet this demand. This study evaluates the value of ICG visualization in PLC and liver metastases surgery regarding R0 resection rates.

MATERIALS AND METHODS

Patients with PLC or liver metastases were included in this prospective cohort study. ICG 10 mg was administered intravenously 24 h before surgery. Real-time intraoperative NIRF visualization was created with the Spectrum^TM fluorescence imaging camera system. First, all liver segments were inspected with the fluorescence imaging system and intraoperative ultrasound for identification of the known tumor, as well as additional lesions, and were compared to preoperative MRI images. PLC, liver metastases, and additional lesions were then resected according to oncological principles. In all resected specimens, the resection margins were analyzed with the fluorescence imaging system for ICG-positive spots immediately after resection. Histology of additional detected lesions, as well as ICG fluorescence compared to histological resection margins, were assessed.

RESULTS

Of the 66 included patients, median age was 65.5 years (IQR 58.7-73.9), 27 (40.9%) were female, and 18 (27.3%) were operated on laparoscopically. Additional ICG-positive lesions were detected in 23 (35.4%) patients, of which 9 (29%) were malignant. In patients with no fluorescent signal at the resection margin, R0 rate was 93.9%, R1 rate was 6.1%, and R2 rate was 0% compared to an ICG-positive resection margin with an R0 rate of 64.3%, R1 rate of 21.4%, and R2 rate of 14.3% (p = 0.005). One- and two-year overall survival rates were 95.2% and 88.4%, respectively.

CONCLUSION

The presented study provides significant evidence that ICG NIRF guidance helps to identify R0 resection intraoperatively. This offers true potential to verify radical resection and improve patient outcomes. Furthermore, implementation of NIRF-guided imaging in liver tumor surgery allows us to detect a considerable amount of additional malignant lesions.

Muscarinic Acetylcholine Receptor M3 Expression and Survival in Human Colorectal Carcinoma-An Unexpected Correlation to Guide Future Treatment?

Muscarinic acetylcholine receptor M3 (M3R) has repeatedly been shown to be prominently expressed in human colorectal cancer (CRC), playing roles in proliferation and cell invasion. Its therapeutic targetability has been suggested in vitro and in animal models. We aimed to investigate the clinical role of MR3 expression in CRC for human survival. Surgical tissue samples from 754 CRC patients were analyzed for high or low immunohistochemical M3R expression on a clinically annotated tissue microarray (TMA). Immunohistochemical analysis was performed for established immune cell markers (CD8, TIA-1, FOXP3, IL 17, CD16 and OX 40). We used Kaplan-Meier curves to evaluate patients' survival and multivariate Cox regression analysis to evaluate prognostic significance. High M3R expression was associated with increased survival in multivariate (hazard ratio (HR) = 0.52; 95% CI = 0.35-0.78; p = 0.001) analysis, as was TIA-1 expression (HR = 0.99; 95% CI = 0.94-0.99; p = 0.014). Tumors with high M3R expression were significantly more likely to be grade 2 compared to tumors with low M3R expression (85.7% vs. 67.1%, p = 0.002). The 5-year survival analysis showed a trend of a higher survival rate in patients with high M3R expression (46%) than patients with low M3R expression CRC (42%) (p = 0.073). In contrast to previous in vitro and animal model findings, this study demonstrates an increased survival for CRC patients with high M3R expression. This evidence is highly relevant for translation of basic research findings into clinically efficient treatments.

[Effectiveness of Mucosal Advancement Flaps in Surgery of Perianal Fistulas from Crohn´s Disease and Cryptoglandular Fistulas - a Long-term Follow-up Study]

AIM

Surgical treatment of perianal fistulae originating from Crohn's Disease (CD) or cryptoglandular abscess (CGA) remains a challenge. Data on long-term healing rates are scarce. We aimed to evaluate the long-term success rate of mucosal advancement flap (MAF) operations.

METHODS

This single centre retrospective analysis was performed at a tertiary referral centre (Charité University Hospital Berlin, Campus Benjamin Franklin) between March 1, 2010 and March 31, 2020. Patients with complex perianal fistulae originating from CD or CGA treated with MAF were included. Long-time healing rates of MAF in CGA and CD were compared. Regression analysis was used to identify predictive factors for definitive healing.

RESULTS

83 patients (24 CD, 59 CGA,) were included. Median follow-up for CD was 5.4 and 1.9 years for CGA. Definitive healing of fistulae was achieved in 19 (79.2%) CD patients (p = 0.682) and in 44 (74.6%) CGA patients. Healing time was significantly shorter in CGA than in CD (9.3 months [standard deviation: SD= 11.3 months] vs. 30.9 months [SD = 23.5 months]; p < 0.001). Treatment with biologicals (hazard ratio: HR = 0.18, 95%-confidence interval: 95%-CI = 0.06-0.59, p = 0.004) and diverting ileostomy (HR = 0.29, 95%-CI = 0.10-0.85, p = 0.023) in CD were independent predictors for MAF success. Simultaneous medication with azathioprine in CD was an independent predictor for MAF failure (HR = 3.20, 95%-CI = 1.05-9.81, p = 0.041).

CONCLUSION

This study demonstrates that surgical therapy of perianal fistulae with MAF is successful in about 75% of patients overall. Patients with MC benefit from biologicals and a diverting ileostomy. Treatment with azathioprine had a negative impact on recurrence rates. Repeated MAF operations did not increase the risk of failure in subsequent operations.

Near-infrared Fluorescence Imaging for Detecting Pancreatic Liver Metastasis in an Orthotopic Athymic Mouse Model

BACKGROUND/AIM

Evidence of metastatic disease precludes oncological resection of pancreatic cancer. Near-infrared (NIR) fluorescent labels, such as indocyanine green (ICG), assist in the intraoperative detection of occult and micrometastatic liver disease. The present study aimed to analyse the role of NIR fluorescence imaging using ICG for pancreatic liver disease as proof of concept in an orthotopic athymic mouse model.

MATERIALS AND METHODS

Pancreatic ductal adenocarcinoma was induced by injecting L3.6pl human pancreatic tumour cells into the pancreatic tail of seven athymic mice. After four weeks of tumour growth, ICG was injected into the tail vein and NIR fluorescence imaging was performed at harvest to determine tumour-to-liver ratios (TLR) using Quest Spectrum^® Fluorescence Imaging Platform.

RESULTS

Pancreatic tumour growth and liver metastasis could be visually confirmed for all seven animals. None of the hepatic metastases showed any detectable ICG-uptake. ICG-staining failed to visualize the liver metastases or to increase fluorescence intensity of the rim around the hepatic lesions.

CONCLUSION

ICG-staining fails to visualize liver metastases induced by L3.6pl pancreatic tumour cells in athymic nude mice by NIR fluorescence imaging. Further studies are necessary to delineate the underlying mechanism for insufficient ICG uptake in these pancreatic liver metastases and for the lack of a fluorescent rim around the liver lesions.

The Immune Checkpoint Landscape in Tumor Cells of Pancreatic Ductal Adenocarcinoma

Immune checkpoint therapy (ICT) has shown promising potential in the treatment of multiple solid tumors. However, the role of ICT in pancreatic ductal adenocarcinoma (PDAC) remains limited. Patterns of immune checkpoints (ICs) in PDAC represent the basis for establishing a potent ICT. The aim of this study is to create a profile of IC expression and its prognostic relevance in cancer cells of PDAC. Therefore, tumor cells from peripheral and central tissue microarray (TMA) spots from histologically confirmed PDAC of 68 patients after tumor resection were investigated in terms of expressions of TIM3, IDO, B7H4, LAG3, VISTA, and PD-L1 using immunohistochemistry. The presence of the respective ICs was compared to overall survival (OS). The presence of VISTA and PD-L1 significantly correlates with shorter OS (median OS: 22 months vs. 7 months and 22 months vs. 11 months, respectively, p < 0.05). For the presence of TIM3, IDO, B7H4, and LAG3, no difference in OS was observed (p > 0.05). The analysis of OS of combined subgroups for VISTA and PD-L1 (VISTA and PD-L1 neg., VISTA pos. and PD-L1 neg., VISTA neg. and PD-L1 pos., and VISTA and PD-L1 pos.) yielded overall statistical significance difference (p = 0.02). These results suggest that the presence of VISTA and PD-L1 is of prognostic relevance and potentially qualifies them as targets for ICT.

Prognostic value of primary tumor sidedness in patients with non-metastatic IBD related CRC - Is it the exception to the rule?

BACKGROUND

Although primary tumor sidedness (PTS) has a known prognostic role in sporadic colorectal cancer (CRC), its role in Inflammatory Bowel Disease related CRC (IBD-CRC) is largely unknown. Thus, we aimed to evaluate the prognostic role of PTS in patients with IBD-CRC.

METHODS

All eligible patients with surgically treated, non-metastatic IBD-CRC were retrospectively identified from institutional databases at ten European and Asian academic centers. Long term endpoints included recurrence-free (RFS) and overall survival (OS). Multivariable Cox proportional hazard regression as well as propensity score analyses were performed to evaluate whether PTS was significantly associated with RFS and OS.

RESULTS

A total of 213 patients were included in the analysis, of which 32.4% had right-sided (RS) tumors and 67.6% had left-sided (LS) tumors. PTS was not associated with OS and RFS even on univariable analysis (5-year OS for RS vs LS tumors was 68.0% vs 77.3%, respectively, p = 0.31; 5-year RFS for RS vs LS tumors was 62.8% vs 65.4%, respectively, p = 0.51). Similarly, PTS was not associated with OS and RFS on propensity score matched analysis (5-year OS for RS vs LS tumors was 82.9% vs 91.3%, p = 0.79; 5-year RFS for RS vs LS tumors was 85.1% vs 81.5%, p = 0.69). These results were maintained when OS and RFS were calculated in patients with RS vs LS tumors after excluding patients with rectal tumors (5-year OS for RS vs LS tumors was 68.0% vs 77.2%, respectively, p = 0.38; 5-year RFS for RS vs LS tumors was 62.8% vs 59.2%, respectively, p = 0.98).

CONCLUSIONS

In contrast to sporadic CRC, PTS does not appear to have a prognostic role in IBD-CRC.

Diagnostic Accuracy of Magnetic Resonance Enterography for the Evaluation of Active and Fibrotic Inflammation in Crohn’s Disease

Background

Despite the success of standard magnetic resonance enterography (MRE) in detecting Crohn’s disease (CD), characterization of strictures and, thus, therapy guidance is still limited. The aim of the study was to determine diagnostic accuracy of MRE in detecting or ruling out active inflammation and identifying fibrotic lesions in patients with terminal ileal CD with histopathology as reference.

Methods

Sixty-seven consecutive patients (median age 32 years, range 19–79 years) with terminal ileal CD were retrospectively enrolled between January 2015 and October 2020. The median interval between MRE and surgery was 9 days (range 0–86 days). Sensitivity, specificity, positive and negative predictive value (PPV and NPV, respectively), and area under the curve (AUC) with 95% confidence intervals (CIs) were calculated for the MRE-based AIS (acute inflammation score) using the histopathology of surgical specimens as the reference standard.

Results

Sensitivity, specificity, PPV, and NPV for detecting or ruling out active inflammation were 100% (CI, 0.94–1.00; 0.44–1.00; 0.93–1.00; 0.31–1.00) using an AIS cut-off of >4.1. AUC was 1.00 (CI, 1.00–1.00; p < 0.01). In all patients with fibrotic changes only and no active inflammation, AIS was <4.1. Interobserver agreement was substantial (κ = 0.65, p < 0.01).

Conclusion

Our study has shown an excellent diagnostic performance of the MRE-based AIS for determining whether active inflammation is present or lesions are due to chronic changes in ileal CD using the histopathology of surgical specimens as reference. These findings indicate that the MRE-based AIS allows a better determination of the inflammatory stage of terminal ileal CD, which facilitates the decision to perform surgery.

Is There an Association between Intra-Operative Detection of Pathogens in Subcutaneous Tissue and Surgical Site Infections? Results from a Prospective Study

Background: Surgical site infections (SSIs) are a common complication in visceral surgery. Pathogens causing SSIs vary depending on the type of surgery. Patients and Methods: Within the scope of the Reduction of Postoperative Wound Infections by Antiseptica (RECIPE) trial we analyzed the pathogens cultured in intra-operative, subcutaneous swabs and in swabs from SSI in a single-center, prospective, randomized controlled study. Definition of SSI complied with the criteria of the U.S. Centers for Disease Control and Prevention (CDC). Results: The overall rate of SSI was 28.2% in 393 patients. Colorectal surgery was performed in 68.2% of elective laparotomies. Pathogens were more often detected in intra-operative subcutaneous swabs in patients who developed SSIs than in patients who did not develop SSIs (64.4% vs. 38.0%; p < 0.001). Enterococci were found in 29.1% of intra-operative swabs in patients with SSIs, followed by Escherichia coli in 15.5%. A higher rate of Enterococcus faecium was found in patients with anemia versus those without anemia (9.2% vs. 2.3%; p = 0.006) and in patients who smoked versus those who did not (11.8% vs. 3.6%; p = 0.008). A positive subcutaneous swab (odds ratio [OR], 2.51; 95% confidence interval [CI], 1.47-4.29; p = 0.001), pre-operative anemia (OR, 1.84; 95% CI, 1.08-3.13; p = 0.016), and renal insufficiency (OR, 2.15; 95% CI, 1.01-4.59; p = 0.048) were risk factors for SSIs. Conclusions: There is an association between the intra-operative detection of pathogens in subcutaneous tissue and the development of SSIs in visceral surgery. The most prevalent pathogens causing SSIs were enterococci and Escherichia coli. More efforts are justified to reduce subcutaneous colonization with pathogens, for example by using intra-operative wound irrigation with polyhexanide solution. This trial is registered at www.ClinicalTrials.gov (ID: NCT04055233).

Impact of myopenia and myosteatosis on postoperative outcome and recurrence in Crohn's disease

PURPOSE

Myopenia and myosteatosis have been proposed to be prognostic factors of surgical outcomes for various diseases, but their exact role in Crohn's disease (CD) is unknown. The aim of this study is to evaluate their impact on anastomotic leakage, CD recurrence, and postoperative complications after ileocecal resection in patients with CD.

METHODS

A retrospective analysis of CD patients undergoing ileocecal resection at our tertiary referral center was performed. To assess myopenia, skeletal muscle index (skeletal muscle area normalized for body height) was measured using an established image analysis method at third lumbar vertebra level on MRI cross-sectional images. Muscle signal intensity was measured to assess myosteatosis index.

RESULTS

A total of 347 patients were retrospectively analyzed. An adequate abdominal MRI scan within 12 months prior to surgery was available for 223 patients with median follow-up time of 48.8 months (IQR: 20.0-82.9). Anastomotic leakage rate was not associated with myopenia (SMI: p = 0.363) or myosteatosis index (p = 0.821). Patients with Crohn's recurrence had a significantly lower SMI (p = 0.047) in univariable analysis, but SMI was not an independent factor for recurrent anastomotic stenosis in multivariable analysis (OR 0.951, 95% CI 0.840-1.078; p = 0.434). Postoperative complications were not associated with myopenia or myosteatosis.

CONCLUSION

Based on the largest cohort of its kind with a long follow-up time, we could provide some data that MRI parameters for myopenia and myosteatosis may not be reliable predictors of postoperative outcome or recurrence in patients with Crohn's disease undergoing ileocecal resection.

Inflammation of the rectal remnant endangers the outcome of ileal pouch-anal anastomosis: a case-control study

BACKGROUND

Inflammation of the rectal remnant may affect the postoperative outcome of ileal pouch-anal anastomosis (IPAA) in patients with ulcerative colitis (UC). We aimed to determine the extent of inflammation in the anastomotic area during IPAA and to investigate the impact of proctitis on postoperative complications and long-term outcomes.

METHODS

Three hundred thirty-four UC patients with primary IPAA were included in this retrospective case-control study. The histopathologic degree of inflammation in the anastomotic area was graded into three stages of no proctitis ("NOP"), mild to medium proctitis ("MIP"), and severe proctitis ("SEP"). Preoperative risk factors, 30-day morbidity, and follow-up data were assessed. Kaplan-Meier analysis was performed in the event of pouch failure.

RESULTS

The prevalence of proctitis was high (MIP 40.4%, and SEP 42.8%). During follow-up, the incidence of complications was highest among SEP: resulting in re-intervention (n = 40; 28.2%, p = 0.017), pouchitis (n = 36; 25.2%, p < 0.01), and pouch failure (n = 32; 22.4%, p = 0.032). The time interval to pouch failure was 5.0 (4.0-6.9) years among NOP, and 1.2 (0.5-2.3) years in SEP (p = 0.036). ASA 3, pouchitis, and pouch fistula were independent risk factors for pouch failure.

CONCLUSION

Proctitis at the time of IPAA is common. A high degree of inflammation is associated with poor long-term outcomes, an effect that declines over time. In addition, a higher degree of proctitis leads to earlier pouch failure.

Rethinking the TNM Classification Regarding Direct Lymph Node Invasion in Pancreatic Ductal Adenocarcinoma

Simple Summary

Due to the rising burden of pancreatic cancer and poor outcomes, a precise, post-operative cancer staging for further and individualized therapy is needed. In the latest cancer classification system, the lymph node invasion mechanism is not addressed. Due to different outcomes regarding the lymph node invasion, we suggest a rethinking of the current system.

Abstract

Mechanisms of lymph node invasion seem to play a prognostic role in pancreatic ductal adenocarcinoma (PDAC) after resection. However, the 8th edition of the TNM classification of the American Joint Committee on Cancer (AJCC) does not consider this. The aim of this study was to analyse the prognostic role of different mechanisms of lymph node invasion on PDAC. One hundred and twenty-two patients with resected PDAC were examined. We distinguished three groups: direct (per continuitatem, Nc) from the main tumour, metastasis (Nm) without any contact to the main tumour, and a mixed mechanism (Ncm). Afterwards, the prognostic power of the different groups was analysed concerning overall survival (OS). In total, 20 patients displayed direct lymph node invasion (Nc = 16.4%), 44 were classed as Nm (36.1%), and 21 were classed as Ncm (17.2%). The difference in OS was not statistically significant between N0 (no lymph node metastasis, n = 37) and Nc (p = 0.134), while Nm had worse OS than N0 (p < 0.001). Direct invasion alone had no statistically significant effect on OS (p = 0.885). Redefining the N0 stage by including Nc patients showed a more precise OS prediction among N stages (p = 0.001 vs. p = 0.002). Nc was more similar to N0 than to Nm; hence, we suggest a rethinking of TNM classification based on the mechanisms of lymph node metastases in PDAC. Overall, this novel classification is more precise.

The impact of surgical site infection-a cost analysis

Purpose

Surgical site infection (SSI) occurs in up to 25% of patients after elective laparotomy. We aimed to determine the effect of SSI on healthcare costs and patients’ quality of life.

Methods

In this post hoc analysis based on the RECIPE trial, we studied a 30-day postoperative outcome of SSI in a single-center, prospective randomized controlled trial comparing subcutaneous wound irrigation with 0.04% polyhexanide to 0.9% saline after elective laparotomy. Total medical costs were analyzed accurately per patient with the tool of our corporate controlling team which is based on diagnosis-related groups in Germany.

Results

Between November 2015 and May 2018, 456 patients were recruited. The overall rate of SSI was 28.2%. Overall costs of inpatient treatment were higher in the group with SSI: median 16.685 €; 19.703 USD (IQR 21.638 €; 25.552 USD) vs. median 11.235 €; 13.276 USD (IQR 11.564 €; 13.656 USD); p < 0.001. There was a difference in surgery costs (median 6.664 €; 7.870 USD with SSI vs. median 5.040 €; 5.952 USD without SSI; p = 0.001) and costs on the surgical ward (median 8.404 €; 9.924 USD with SSI vs. median 4.690 €; 5.538 USD without SSI; p < 0.001). Patients with SSI were less satisfied with the cosmetic result (4.3% vs. 16.2%; p < 0.001). Overall costs for patients who were irrigated with saline were median 12.056 €; 14.237 USD vs. median 12.793 €; 15.107 USD in the polyhexanide group (p = 0.52).

Conclusion

SSI after elective laparotomy increased hospital costs substantially. This is an additional reason why the prevention of SSI is important. Overall costs for intraoperative wound irrigation with saline were comparable with polyhexanide.

Peptide Signatures for Prognostic Markers of Pancreatic Cancer by MALDI Mass Spectrometry Imaging

Despite the overall poor prognosis of pancreatic cancer there is heterogeneity in clinical courses of tumors not assessed by conventional risk stratification. This yields the need of additional markers for proper assessment of prognosis and multimodal clinical management. We provide a proof of concept study evaluating the feasibility of Matrix-assisted laser desorption/ionization (MALDI) mass spectrometry imaging (MSI) to identify specific peptide signatures linked to prognostic parameters of pancreatic cancer. On 18 patients with exocrine pancreatic cancer after tumor resection, MALDI imaging analysis was performed additional to histopathological assessment. Principal component analysis (PCA) was used to explore discrimination of peptide signatures of prognostic histopathological features and receiver operator characteristic (ROC) to identify which specific m/z values are the most discriminative between the prognostic subgroups of patients. Out of 557 aligned m/z values discriminate peptide signatures for the prognostic histopathological features lymphatic vessel invasion (pL, 16 m/z values, eight proteins), nodal metastasis (pN, two m/z values, one protein) and angioinvasion (pV, 4 m/z values, two proteins) were identified. These results yield proof of concept that MALDI-MSI of pancreatic cancer tissue is feasible to identify peptide signatures of prognostic relevance and can augment risk assessment.

Assessment of Risk Factors for the Occurrence of a High-Output Ileostomy

Background: Ileostomy is often required in patients undergoing bowel resections for inflammatory bowel diseases (IBD), colorectal cancer, and emergencies. Unfortunately, some patients develop a high-output stoma (HOS). This condition affects homeostasis and may be life threatening. We aimed to identify possible risk factors for the development of HOS. Patients and methods: From 2012 to 2018, 296 patients who underwent ileostomy at Charité - Universitätsmedizin Berlin, Campus Benjamin Franklin were retrospectively analyzed. Emergency operations were included. Diverting ileostomy, end ileostomies and anastomotic stomata with at least part ileum, were examined. HOS was defined as stoma output of more than 1,000 mL per day for more than 3 days. Univariate and multivariable analyses were used to detect potential risk factors for the development of HOS. Results: 41 of 296 patients developed HOS (13.9%). Mortality was 0.3%. In the univariate analysis, age (p < 0.002), diagnosis (Crohn's disease, p = 0.005), arterial hypertension (p = 0.023), surgical procedure (right-sided colectomy, small bowel resection, p < 0.001), open technique (p < 0.002), emergencies (p = 0.014), and anastomotic ileostomy (p < 0.001) were identified as risk factors. In the multivariable logistic regression, older age, diagnosis (Crohn's disease) and surgical procedure (right-sided colectomy, separate ileostomy, small bowel resection) remained significant risk factors. Conclusion: The occurrence of HOS is a relevant problem after ileostomy. The identification of risk factors for a high-output may be helpful for monitoring, early diagnosis and initiation of therapy as well as in the planning of close follow-up care.

Microscopic inflammation in ileocecal specimen does not correspond to a higher anastomotic leakage rate after ileocecal resection in Crohn's disease

Background

Patients with Crohn’s disease suffer from a higher rate of anastomotic leakages after ileocecal resection than patients without Crohn’s disease. Our hypothesis was that microscopic inflammation at the resection margins of ileocecal resections in Crohn’s disease increases the rate of anastomotic leakages.

Patients and methods

In a retrospective cohort study, 130 patients with Crohn’s disease that underwent ileocecal resection between 2015 and 2019, were analyzed. Anastomotic leakage was the primary outcome parameter. Inflammation at the resection margin was characterized as “inflammation at proximal resection margin”, “inflammation at distal resection margin” or “inflammation at both ends”.

Results

46 patients (35.4%) showed microscopic inflammation at the resection margins. 17 patients (13.1%) developed anastomotic leakage. No difference in the rate of anastomotic leakages was found for proximally affected resection margins (no anastomotic leakage vs. anastomotic leakage: 20.3 vs. 35.3%, p = 0.17), distally affected resection margins (2.7 vs. 5.9%, p = 0.47) or inflammation at both ends (9.7 vs. 11.8%, p = 0.80). No effect on the anastomotic leakage rate was found for preoperative hemoglobin concentration (no anastomotic leakage vs. anastomotic leakage: 12.3 vs. 13.5 g/dl, p = 0.26), perioperative immunosuppressive medication (62.8 vs. 52.9%, p = 0.30), BMI (21.8 vs. 22.4 m²/kg, p = 0.82), emergency operation (21.2 vs. 11.8%, p = 0.29), laparoscopic vs. open procedure (p = 0.58), diverting ileostomy (31.9 vs. 57.1%, p = 0.35) or the level of surgical training (staff surgeon: 80.5 vs. 76.5%, p = 0.45).

Conclusion

Microscopic inflammation at the resection margins after ileocecal resection in Crohn’s disease is common. Histologically inflamed resection margins do not appear to affect the rate of anastomotic leakages. Our data suggest that there is no need for extensive resections or frozen section to achieve microscopically inflammation-free resection margins.

Risk factors for upper and lower type prolonged postoperative ileus following surgery for Crohn's disease

PURPOSE

Prolonged postoperative ileus (PPOI) is common after bowel resections, especially in Crohn's disease (CD). The pathophysiology of PPOI is not fully understood. PPOI could affect only the upper or lower gastrointestinal (GI) tract. The aim of this study was to assess risk factors for diverse types of PPOI, particularly to differentiate PPOI of upper and lower GI tract.

METHODS

A retrospective analysis of 163 patients with CD undergoing ileocecal resection from 2015 to 2020 in a single center was performed. PPOI of the upper GI tract was predefined as the presence of vomiting or use of nasogastric tube longer than the third postoperative day. Lower PPOI was predefined as the absence of defecation for more than three days. Independent risk factors were identified by multivariable logistic regression analysis.

RESULTS

Overall incidence of PPOI was 42.7%. PPOI of the upper GI tract was observed in 30.7% and lower PPOI in 20.9% of patients. Independent risk factors for upper PPOI included older age, surgery by a resident surgeon, hand-sewn anastomosis, prolonged opioid analgesia, and reoperation, while for lower PPOI included BMI ≤ 25 kg/m², preoperative anemia, and absence of ileostomy.

CONCLUSION

This study identified different risk factors for upper and lower PPOI after ileocecal resection in patients with CD. A differentiated upper/lower type approach should be considered in future research and clinical practice. High-risk patients for each type of PPOI should be closely monitored, and modifiable risk factors, such as preoperative anemia and opioids, should be avoided if possible.

Validation of the German Classification of Diverticular Disease (VADIS)-a prospective bicentric observational study

PURPOSE

The German Classification of Diverticular Disease was introduced a few years ago. The aim of this study was to determine whether Classification of Diverticular Disease enables an exact stratification of different types of diverticular disease in terms of course and treatment.

METHODS

This was a prospective, bicentric observational trial. Patients aged ≥ 18 years with diverticular disease were prospectively included. The primary endpoint was the rate of recurrence within 2 year follow-up. Secondary outcome measures were Gastrointestinal Quality of Life Index, Quality of life measured by SF-36, frequency of gastrointestinal complaints, and postoperative complications.

RESULTS

A total of 172 patients were included. After conservative management, 40% of patients required surgery for recurrence in type 1b vs. 80% in type 2a/b (p = 0.04). Sixty percent of patients with type 2a (micro-abscess) were in need of surgery for recurrence vs. 100% of patients with type 2b (macro-abscess) (p = 0.11). Patients with type 2a reached 123 ± 15 points in the Gastrointestinal Quality of Life Index compared with 111 ± 14 in type 2b (p = 0.05) and higher scores in the "Mental Component Summary" scale of SF-36 (52 ± 10 vs. 43 ± 13; p = 0.04). Patients with recurrent diverticulitis without complications (type 3b) had less often painful constipation (30% vs. 73%; p = 0.006) when they were operated compared with conservative treatment.

CONCLUSION

Differentiation into type 2a and 2b based on abscess size seems reasonable as patients with type 2b required surgery while patients with type 2a may be treated conservatively. Sigmoid colectomy in patients with type 3b seems to have gastrointestinal complaints during long-term follow-up.

TRIAL REGISTRATION

https://www.drks.de ID: DRKS00005576.

Does migrant background predict to what extent colorectal cancer patients want to be informed about their life expectancy? - a cross-sectional analysis

BACKGROUND

Although migrant health is a topic of interest across Europe and although health care services in Germany consider migrant health issues, people with a migrant background often experience difficulties regarding health care provision. The prevalence of various cancers among migrants is lower relative to non-migrants although this equalizes with increasing duration of residence. There are documented differences in health behavior and disease-coping strategies between migrants and non-migrants, but data are scarce on this subject. This analysis investigates the extent of information migrant and non-migrant colorectal cancer (CRC) patients in Germany want about their life expectancy and the level of trust they have in their treating physician.

METHOD

Data from 522 CRC patients were collected through a self-reported questionnaire. Migrant background was determined by the patients' and/or their parents' birthplace. Bivariate analyses were applied to determine the differences between migrants and non-migrants. A multivariate analysis was used to measure the effect of migration background, demographics, and cancer stage and treatment on the preferred extent of information about life expectancy and trust in their treating physician.

RESULTS

There were no significant differences regarding demographics or cancer stage and treatment between migrant and non-migrant CRC patients. Having a migrant background had no influence on the level of trust in the treating physician, but migrants preferred to be less informed about their life expectancy than non-migrants (21.4% vs. 13.4%, p = 0.04). The multivariate analysis showed that men (aOR = 2.102, CI: 1.123-3.932) and patients with a non-migrant background (aOR = 5.03, CI: 1.02-24.73) preferred receiving information about the approximate value of their life expectancy, rather than receiving no information.

CONCLUSION

The study found more similarities than discrepancies between migrant and non-migrant CRC patients regarding demographic factors and stage of disease and treatment, which may be a consequence of an increasingly homogeneous cross-cultural society. However, cultural differences between the minority and host population remain and should always be taken into account in daily clinical practice and in the communication skills training of health care professionals. The study also indicates that recording migration background into health registers would facilitate migrant-sensitive research.

Sources of Support and Information During Disease: An Exploratory Study, Comparing Migrant and Nonmigrant Colorectal Cancer Patients in Germany

Introduction: The prevalence of cancer diseases among migrants is lower relative to nonmigrants, although this equalizes with increasing duration of residence. There are differences in the health behaviors and disease coping strategies between these two groups. The aim of this analysis is to compare migrant and nonmigrant colorectal cancer (CRC) patients in Germany regarding their sources of support and information during disease. Method: Data from 522 CRC patients, collected through a survey about satisfaction with care, were analyzed by descriptive and multivariate statistics. Results: Migrants and nonmigrants differed in two aspects: Migrants reported to receive the most relevant support during disease more often by nonmedical people, compared with nonmigrants, and they favored videos explaining the therapeutic steps of CRC more than nonmigrants. Discussion: Anticipating which types of support and information sources patients will access during their disease may help guide future diversity management across the field of cancer care.

Exploring the characteristics and potential disparities of non-migrant and migrant colorectal cancer patients regarding their satisfaction and subjective perception of care - a cross-sectional study

Background

Although a fifth of the German population has a migration background, health research regarding this population is scarce. The few existing studies on migrant health show that migrants are faced with restrictions regarding health care due to communication problems, a lack of information and distinct health literacy. Colorectal cancer (CRC) is the second most common tumor disease in Germany. The aim of the study is to explore the potential differences in patient characteristics between migrants and non-migrants with CRC and identify possible disparities between migrants and non-migrants regarding their satisfaction and perception with health care.

Methods

A validated questionnaire was modified for CRC, supplemented with items regarding migration background, translated additionally into Arabic, Turkish and Russian and sent out to 1.694 CRC patients. The outcome indicator was ‘health care satisfaction and experience’ concerning ‘medical consultation’, ‘medical treatment (therapy)’ and ‘hospital stay’ measured on 10-point Likert-scales; explanatory variables were migration background, age, gender, mother tongue, occupation, follow-up care, current discomfort and current treatment. Following descriptive statistics, factor analysis was conducted to compute the outcome variables. Differences between migrants and non-migrants were analyzed using Mann-Whitney-U test and regression analyses.

Results

A total of 522 completed questionnaires – 30.8% response rate – were used for analysis. Patients with a migration background attended less often follow up care than non-migrant patients (74.7% vs. 88.6%; p = 0.001). Mean scores regarding satisfaction and experience with consultation, medical treatment (therapy) and hospital stay were 7.86, 7.11 and 7.51 for migrants and 7.84, 7.19 and 7.33 for non-migrants, measured on a 1 to 10 scale with 10 being most satisfied. Migrants were less satisfied with their own involvement in decision making (p = 0.029) and the aspect “responsiveness to patient’s questions” (p = 0.048) than non-migrants.

Conclusions

Migrants showed less compliance with regard to follow-up care than non-migrants. Furthermore, migrants were more often dissatisfied with communication with the medical staff than non-migrants. This shows the importance of (cross-cultural) communication skills on the part of physicians and nurses.

Influence of pelvic volume on surgical outcome after low anterior resection for rectal cancer

BACKGROUND

Low anterior resection (LAR) for rectal cancer is a potentially challenging operation due to limited space in the pelvis. CT pelvimetry allows to quantify pelvic space, so that its relationship with outcome after LAR may be assessed. Studies investigating this, however, yielded conflicting results. We hypothesized that a small pelvis is associated with a higher rate of incomplete mesorectal excision, anastomotic leakages, and increased rate of urinary dysfunction in patients operated for rectal cancer.

METHODS

In a single-center retrospective analysis, we studied 74 patients that underwent LAR for rectal cancer with primary anastomosis. Thin-layered multi-slice CT datasets were used for slice by slice depiction of the inner pelvic surface, and the inner pelvic volume was automatically compounded. The primary outcome was quality of total mesorectal excision (TME; Mercury grading); secondary outcomes were anastomotic leakage and urinary dysfunction with regard to pelvic dimensions. Univariate analyses and multiple logistic regression analyses were performed for the primary and the secondary outcomes.

RESULTS

Shorter obstetric conjugate diameters were associated with a higher probability of a worse TME quality (110.8 ± 10.2 vs. 105.0 ± 8.6 mm; OR 0.85; 95% CI 0.73-0.99; p = 0.038). Short interspinous distance showed a trend towards an increased risk for deteriorated TME quality (OR 0.88; 95% CI 0.76-1.0; p = 0.06). Anastomotic leakage was associated with anemia (OR 2.77; 95% CI 1.0-7.7; p = 0.047). Association between pelvic diameters or pelvic volume and anastomotic leakage or urinary dysfunction was not observed. Perioperative blood transfusions were administered more often in patients with postoperative urinary dysfunction (OR 17.67; 95% CI 2.44-127.7; p = 0.004).

CONCLUSION

Shorter obstetric conjugate diameter might be a risk factor for incompleteness of total mesorectal excision. Anastomotic leakage seems to be influenced more by clinical factors such as anemia rather than pelvic dimensions. Further studies have to prove the influence of pelvic diameter on local recurrence of rectal cancer after LAR.

CT-based measurement of the inner pelvic volume

Background Surgery in the lesser pelvis is associated with a high complication rate as surgeons are spatially limited by solid anatomic structures and soft tissue borders. So far, only two-dimensional (2D) parameters have been used for risk stratification. Purpose To precisely measure the inner pelvic volume a computed tomography (CT)-based three-dimensional (3D) approach was established and compared to approximations by 2D parameter combinations. Material and Methods Thin-layered multi-slice CT datasets were used retrospectively for slice by slice depiction of the inner pelvic surface. The inner pelvic volume was then automatically compounded. Combinations of two to four 2D dimensions determined in 3D volume rendered reconstructions were correlated with the inner pelvic volume. Pearson's correlation coefficient and Chi square test were used for statistical calculations. Significance level was set at P < 0.05. Results In total 142 patients (91 men, 51 women) aged 64.8 ± 10.6 years at surgery were included in the study. Mean calculated pelvic volume was 1031.13 ± 180.06 cm³ (men, 996.57 ± 172.43 cm³; women, 1093.34 ± 178.39 cm³). Best approximations were obtained by combination of the 2D measurements transverse inlet and pelvic height for men (r = 0.799, P < 0.05) as well as transverse inlet, obstetric conjugate, interspinous distance and pelvic depth for women (r = 0.855, P < 0.05). Conclusion We describe a precise and reproducible CT-based method for pelvic volumetry. A less time consuming but still reliable approximation can be achieved by combination of two to four 2D dimensions.

Risk factors for reoperation after ileostomy reversal - Results from a prospective cohort study

BACKGROUND

Ileostomy reversal is frequently performed in abdominal surgery. Postoperative complications after ileostomy reversal are encountered in around 20% of patients. Data regarding risk factors for reoperation after ileostomy closure are scarce. The purpose of this prospective trial was to determine risk factors for operative revision after ileostomy closure.

MATERIALS AND METHODS

This is an additional post hoc analysis of a two center prospective trial. After enrollment, patient characteristics and intraoperative details were analyzed. Patients were followed up at one postoperative visit before discharge and at a three months postoperative visit by standardized questionnaire. All reoperations occurring in the three months period after surgery were analyzed, and immediate reoperations which were directly related to the ileostomy reversal were analyzed separately.

RESULTS

118 patients with elective ileostomy reversal were included in the trial. 12 out of 106 patients (11.3%) underwent any reoperation within three months after surgery (Clavien-Dindo grade IIIb). On multivariate analysis, anemia was associated with any reoperation p = 0.004; OR 6.93 (95% CI 1.37-30.07). Six out of 114 patients (5.3%) required an immediate reoperation (small bowel perforation, anastomotic leakage, postoperative ileus, deep wound infection) due to surgical complications directly related to the ileostomy reversal. Higher body mass index and anemia were associated with immediate reoperations (BMI: p = 0.038; OR 0.73 (95% CI 0.55-0.98); anemia: p = 0.001; OR 25.50 (95% CI 3.87-168.21).

CONCLUSION

Surgical complications after ileostomy reversal occurred to a substantial extent. Rate of reoperations was associated with anemia and high body mass index. Optimizing patients in terms of preoperative hemoglobin and BMI may reduce surgical complications after ileostomy closure.

Necessity of subcutaneous suction drains in ileostomy reversal (DRASTAR)-a randomized, controlled bi-centered trial

PURPOSE

Data regarding length of hospital stay of patients undergoing ileostomy reversal are very heterogeneous. There are many factors that may have an influence on the length of postoperative hospital stay, such as postoperative wound infections. One potential strategy to reduce their incidence and to decrease hospital stay is to insert subcutaneous suction drains. The purpose of this study was to examine the influence of the insertion of subcutaneous suction drains on hospital stay and postoperative wound infections in ileostomy reversal. Risk factors for postoperative wound infection were determined.

METHODS

This is a randomized controlled two-center non-inferiority trial with two parallel groups. The total length of hospital stay as primary endpoint and the occurrence of a surgical site infection, the colonization of the abdominal wall with bacteria, and the occurrence of hematomas/seromas as secondary endpoints were monitored.

RESULTS

One hundred eighteen patients with elective ileostomy reversal were included. Fifty-nine patients were randomly assigned to insertion of a subcutaneous suction drain, and 59 patients were randomly assigned to receive no drain. After 3 months of follow-up, 50 patients in the group with drain and 53 patients in the group without drain could be analyzed. Median total length of hospital stay was 8 days in the SD group and 9 days in the group without SD (p = 0.17). Fourteen percent of patients with SD and 17 % without SD developed SSI, p = 0.68. Multivariate analysis revealed anemia (p < 0.01), intraoperative bowel perforation (p = 0.02) and resident (p = 0.04) or fellow (p = 0.048) performing the operation as risk factors for SSI.

CONCLUSIONS

This trial shows that the omission of subcutaneous suction drains is not inferior to the use of subcutaneous suction drains after ileostomy reversal in terms of length of hospital stay, surgical site infections, and hematomas/seromas.

[Stump closure in laparoscopic appendectomy. Influence of endoloop or linear stapler on patient outcome]

BACKGROUND

Even though laparoscopic appendectomy is one of the most frequent procedures in abdominal surgery, the technique of appendiceal stump closure is still not standardized. The aim of this retrospective study was to analyze the effect of the use of endoloops or linear staplers for appendiceal stump closure concerning surgical site infections (SSI) and intra-abdominal abscesses (IAA).

PATIENTS AND METHODS

All laparoscopic appendectomies between January 1st 2007 and May 31st 2010 were split into an endoloop group (ELG) and a linear stapler group (LSG). The groups were compared with respect to the outcome parameters SSI and IAA.

RESULTS

A total of 430 appendectomies were performed in the study period of which 105 operations were conducted laparoscopically. In this study 47.6 % (n = 50) were alloted to the LSG and 52.4 % (n = 55) to ELG. In LSG 3.1 % (n = 1) developed an SSI versus 10.0 % (n = 4, p = 0.254) in ELG. No IAAs occurred in LSG compared to 2 (5.1 %, p = 0.499) in ELG.

CONCLUSION

The use of EL for appendiceal stump closure is safe and cost effective for low-grade appendicitis but high-grade appendicitis should be treated with LS.

Antiproliferative and apoptotic effects of telmisartan in human colon cancer cells

Telmisartan is an angiotensin I (AT₁) receptor blocker used in the treatment of essential hypertension, with partial peroxisome proliferator-activated receptor γ (PPARγ) agonism. In prior studies, PPARγ activation led to apoptosis and cell cycle inhibition in various cancer cells. The aim of the present study was to investigate the potential antiproliferative and apoptotic effects of telmisartan by partially activating PPARγ. HT-29, SW-480 and SW-620 cells were incubated with telmisartan (0.2–5 μM) or the full agonist, pioglitazone (0.2–5.0 μM). The antiproliferative and apoptotic effects of telmisartan in the human colon cancer cells were significant at therapeutic serum concentrations, and telmisartan exhibited a potency at least equivalent to the full PPARγ agonist, pioglitazone. The antiproliferative and apoptotic effects of pioglitazone in the human colon cancer cells were not completely deregulated by PPARγ blockade with GW9662. In the telmisartan-treated cells, PPARγ blockade resulted in an increased antiproliferative and apoptotic effect. These effects are not entirely explained by PPARγ activation, however, possible hypotheses that require further experimental investigation are as follows: i) Ligand-independent PPARγ activation through the activation-function 1 domain; ii) a PPARγ-independent mechanism; or iii) independent antiproliferative and apoptotic effects through GW9662.

Increased Pontin expression is a potential predictor for outcome in sporadic colorectal carcinoma

Colorectal cancer is one of the leading causes of cancer-related death worldwide. Molecular biomarkers could help to predict patient outcome and to identify patients who benefit from adjuvant therapy. Pontin and Reptin are ATPases which are involved in transcriptional regulation, DNA damage repair and regulation of cell proliferation. Many interaction partners of Pontin and Reptin such as β-catenin and c-myc are important factors in carcinogenesis. We hypothesized that Pontin and Reptin expression may be a negative predictor for survival in colorectal carcinoma. Specimens from 115 patients with primary colon adenocarcinomas UICC stage III and primary rectal adenocarcinomas UICC stage II and III curatively resected at the Department of Surgery, Charité Berlin, were evaluated. Clinical follow-up data were complete and mean follow-up time of patients was 51.8 months. We evaluated the expression of Pontin, Reptin and Ki-67 by immunohistochemistry. Patients with Pontin-positive carcinomas showed no differences in recurrence-free survival (p=0.109) and overall survival (p=0.197). There were no differences in Reptin-positive carcinomas and Ki-67-positive carcinomas in recurrence-free survival (p=0.443 and p=0.160) and overall survival (p=0.477 and p=0.687). Patients with Pontin-positive colorectal carcinomas receiving adjuvant therapy had a significantly worse recurrence-free survival (p=0.008) and overall survival (p=0.011) than Pontin-negative patients with adjuvant therapy. In UICC stage III, Pontin-positive colorectal carcinomas had a significantly worse recurrence-free survival (p=0.028). Pontin-positivity seems to be a negative predictor for response to adjuvant therapy in colorectal cancer patients and may help to identify patients with adverse outcome in advanced tumor stages.

Long-term follow-up after incisional hernia repair: are there only benefits for symptomatic patients?

INTRODUCTION

Incisional hernias are among the most frequent complications in visceral surgery and are currently considered to be an indication for surgery in all cases, regardless of the patient's symptoms. However, it still remains unclear to what extent surgery actually results in improvement according to objective (e.g., less pain or dysesthesia) or subjective criteria (e.g., less discomfort or better cosmetic result). The purpose of this prospective study was to identify patients who derive objective and subjective benefit from surgical repair.

MATERIALS AND METHODS

This prospective study included patients who underwent open incisional hernia repair with mesh implantation from December 2006 to April 2009. Data were collected before and 18 months after surgery. Pain intensity was rated on the numerical analog scale (NAS) pre- and postoperatively. Patients were divided into oligosymptomatic (NAS 0-3) and symptomatic (NAS 4-10) groups based on their preoperative pain level, and the postoperative outcome of the two groups was compared by standardized questionnaire.

RESULTS

Ninety patients were prospectively enrolled, 45 (50 %) of each gender. Prior to surgery, 43 patients (47.8 %) were oligosymptomatic, and 47 (52.2 %) reported clinically relevant pain. Eighteen months after surgery, 7.5 % of the oligosymptomatic patients complained of clinically relevant pain; its rate remained unchanged. The symptomatic group showed a significant reduction in clinically relevant pain from 100 % to 14.0 %, (p < 0.001). The percentage of patients with clinically relevant dysesthesia was 12.5 % in the oligosymptomatic and 20.9 % in the symptomatic group 18 months postoperatively. The overall recurrence rate was 13.3 % after 18 months without difference in both groups. A reduction in discomfort in the surgical area was reported by 77.5 % of the oligosymptomatic and 79.1 % of the symptomatic patients.

CONCLUSIONS

Symptomatic patients definitely profit from surgical repair in the long-term course. However, the notable postoperative rate of clinically relevant pain and dysesthesia in oligosymptomatic patients and their high recurrence rate cast doubt on whether they really benefit from surgical repair. The remarkable degree of subjective satisfaction in oligosymptomatic patients should not be underestimated.

[Simulation training in surgical education - application of virtual reality laparoscopic simulators in a surgical skills course]

BACKGROUND

Training and simulation are gaining importance in surgical education. Today, virtual reality surgery simulators provide sophisticated laparoscopic training scenarios and offer detailed assessment methods. This also makes simulators interesting for the application in surgical skills courses. The aim of the current study was to assess the suitability of a virtual surgery simulator for training and assessment in an established surgical training course.

MATERIALS AND METHODS

The study was conducted during the annual "Practical Course for Visceral Surgery" (Warnemuende, Germany). 36 of 108 course participants were assigned at random for the study. Training was conducted in 15 sessions over 5 days with 4 identical virtual surgery simulators (LapSim) and 2 standardised training tasks. The simulator measured 16 individual parameters and calculated 2 scores. Questionnaires were used to assess the test persons' laparoscopic experience, their training situation and the acceptance of the simulator training. Data were analysed with non-parametric tests. A subgroup analysis for laparoscopic experience was conducted in order to assess the simulator's construct validity and assessment capabilities.

RESULTS

Median age was 32 (27 - 41) years; median professional experience was 3 (1 - 11) years. Typical laparoscopic learning curves with initial significant improvements and a subsequent plateau phase were measured over 5 days. The individual training sessions exhibited a rhythmic variability in the training results. A shorter night's sleep led to a marked drop in performance. The participants' different experience levels could clearly be discriminated ( ≤ 20 vs. > 20 laparoscopic operations; p ≤ 0.001). The questionnaire showed that the majority of the participants had limited training opportunities in their hospitals. The simulator training was very well accepted. However, the participants severely misjudged the real costs of the simulators that were used.

CONCLUSIONS

The learning curve on the simulator was successfully mastered during the course. Construct validity could be demonstrated within the course setting. The simulator's assessment system can be of value for the assessment of laparoscopic training performance within surgical skills courses. Acceptance of the simulator training is high. However, simulators are currently too expensive to be used within a large training course.

Development of a clinical trial to determine whether watchful waiting is an acceptable alternative to surgical repair for patients with oligosymptomatic incisional hernia: study protocol for a randomized controlled trial

BACKGROUND

Incisional hernia is a frequent complication in abdominal surgery. This article describes the development of a prospective randomized clinical trial designed to determine whether watchful waiting is an acceptable alternative to surgical repair for patients with oligosymptomatic incisional hernia.

METHODS/DESIGN

This clinical multicenter trial has been designed to compare watchful waiting and surgical repair for patients with oligosymptomatic incisional hernia. Participants are randomized to watchful waiting or surgery and followed up for two years. The primary efficacy endpoint is pain/discomfort during normal activities as a result of the hernia or hernia repair two years after enrolment, as measured by the hernia-specific Surgical Pain Scales (SPS). The target sample size of six hundred thirty-six patients was calculated to detect non-inferiority of the experimental intervention (watchful waiting) in the primary endpoint. Sixteen surgical centers will take part in the study and have submitted their declaration of commitment giving the estimated number of participating patients per year. A three-person data safety monitoring board will meet annually to monitor and supervise the trial.

DISCUSSION

To date, we could find no published data on the natural course of incisional hernias. To our knowledge, watchful waiting has never been compared to standard surgical repair as a treatment option for incisional hernias. A trial to compare the outcome of the two approaches in patients with oligosymptomatic incisional hernias is urgently needed to provide data that can facilitate the choice between treatment options. If watchful waiting was equal to surgical repair, the high costs of surgical repair could be saved. The design for such a trial is described here. This multicenter trial will be funded by the German Research Foundation (DFG). The ethics committee of the Charité has approved the study protocol. Approval has been obtained from ten study sites at time of this submission. The electronic Case Report Forms have been created. The first patient was to be randomized November 14th, 2011. An initiation meeting took place in Berlin January 9th, 2012.

TRIAL REGISTRATION

ClinicalTrials.gov: NCT01349400.

Measurable learning effects after a 1-week skills course in digestive surgery

AIM

The aim of this study was to assess the learning effects of a surgical skills course focussed on theoretical knowledge, anastomosis techniques and practical suturing skills in digestive surgery.

METHODS

One hundred eight participants of a 1-week skills course, comprising practical exercises in conventional and laparascopic digestive surgery, were asked to complete questionnaires (self-evaluation and course evaluation) and a theoretical knowledge test prior to the beginning (tp1) and at the end of the course (tp2). Thirty-six randomly selected participants performed a handsewn anastomosis at tp1 and at tp2, whereby the respective performance of each participant was recorded on video film and awarded a comparative rating (points score).

RESULTS

In regard to course expectations, 93.52% of the participants had expressed the objective to acquire knowledge in the field of standard surgical techniques, and 71.30% aimed to brush up their existing knowledge and skills. In this respect, participants' satisfaction at tp2 was recorded as high to very high. Confidence to carry out simple and more complex anastomosis was significantly increased (p < 0.001) at tp2. A significantly higher intestinal suture score (11.94 vs. 9.75) was attained at tp2 in a shorter time (176.22 vs. 277.11 s). The reduction in the time needed to complete the given task was accompanied by a corresponding improvement in the quality (p < 0.001).

CONCLUSION

Surgical skill courses constitute an effective component of surgical training with a sustained impact and, therefore, should be integrated into a future curriculum.

[Experiences from more than 2,100 hernia repair operations. How has the therapy changed in the last 15 years?]

INTRODUCTION

Inguinal hernia (IH) surgery has changed fundamentally during the last 25 years due to tension-free repair, minimally-invasive approaches and growing influence of economy in medical decision making. Aim of the study was the documentation and analysis of changes in IH surgery during the last 15 years in our patient cohort.

MATERIAL AND METHODS

Patients undergoing elective or emergency inguinal/femoral hernia repair from January 1995 to December 2009 were included in the study. Analysis of patient data was carried out by prospective online recording.

RESULTS

A total of 1,908 patients with 2,124 IHs were treated in the study period and the number of IH repairs decreased continuously. The number of recurrent hernias peaked in 2005-2009 with 16.4%. The average preoperative hospital stay decreased from 2.4 to 0.4 days and the postoperative hospital stay from 7.0 to 3.3 days. The percentage of suture repairs declined from 54.9% in 1995 to 4.1% in 2009 and the percentage of open tension-free repairs rose to 52.9% in 1998. In the following years the majority of repairs were performed by minimally invasive procedures but in 2009 the percentage of conventional hernia repairs exceeded the rate of minimally invasive repairs.

CONCLUSION

The main reason for these changes is the implementation of diagnosis-related groups which hampers inpatient repair of "simple" inguinal hernias, favors short hospital stay and does not adequately reimburse minimally invasive repairs.

Face, content and construct validity of a new realistic trainer for conventional techniques in digestive surgery

PURPOSE

Surgical simulation modules for "open" surgery are limited in contrast to well-studied and validated laparoscopic trainers. In this study, face, content and construct validity of a devised simulation module (Berlin Operation Trainer, BOPT) for handsewn anastomoses in digestive surgery were analysed.

MATERIALS AND METHODS

Participants of a skills course for digestive surgery (novices: 1-3 years of training; experts: more than 5 years of training) were timed on performing four defined handsewn digestive anastomoses on formalin fixed porcine intestine in the BOPT. Questionnaires were answered regarding impression with the simulation module concerning appearance and realism using a five-point Likert and a three-point forced choice scale. Face and content validities were evaluated based on the responses of participants and construct validity by comparing novices to experts. Data collected were analysed with Fisher's exact test and two-sample t test.

RESULTS

Twenty-two novices (median: second postgraduate year) and 26 experts (median: seventh postgraduate year) were enrolled in the study. The BOPT showed strong face and content validities with average scores for satisfaction parameters above 4.2 +/- 0.41 and 4.1 +/- 0.22, respectively. Construct validity was adequate for anastomosis simulation in the BOPT based on different percentages of anastomosis complete during set time between novices and experts as shown for simple (68.2% vs. 92.3%, p = 0.038) and for difficult anastomosis (18.2% vs. 50.0%, p = 0.021).

CONCLUSIONS

The BOPT is a suitable instrument for advanced surgical training for novices and experienced colleagues creating a realistic and demanding situation. Further studies have to evaluate if a more realistic preoperative training will support an effective transfer of learned techniques to the operating room.

Association between activation of atypical NF-kappaB1 p105 signaling pathway and nuclear beta-catenin accumulation in colorectal carcinoma

Recent studies have demonstrated that increased expression of coding region determinant-binding protein (CRD-BP) in response to beta-catenin signaling leads to the stabilization of beta-TrCP1, a substrate-specific component of SCF E3 ubiquitin ligase complex, resulting in an accelerated degradation of IkappaBalpha and activation of canonical nuclear factor-kappaB (NF-kappaB) pathway. Here, we show that the noncanonical NF-kappaB1 p105 pathway is constitutively activated in colorectal carcinoma specimens, being particularly associated with beta-catenin-mediated increased expression of CRD-BP and beta-TrCP1. In the carcinoma tissues exhibiting high levels of nuclear beta-catenin the phospho-p105 levels were increased and total p105 amounts were decreased in comparison to that of normal tissue indicating an activation of this NF-kappaB pathway. Knockdown of CRD-BP in colorectal cancer cell line SW620 resulted in significantly higher basal levels of both NF-kappaB inhibitory proteins, p105 and IkappaBalpha. Furthermore decreased NF-kappaB binding activity was observed in CRD-BP siRNA-transfected SW620 cells as compared with those transfected with control siRNA. Altogether, our findings suggest that activation of NF-kappaB1 p105 signaling in colorectal carcinoma might be attributed to beta-catenin-mediated induction of CRD-BP and beta-TrCP1.

["Practical course for visceral surgery in Warnemünde" 10 years on. Significance and benefits of a surgical training course]

BACKGROUND

Skill courses for surgery offer a good but cost and personnel-intensive possibility to obtain practical and theoretical knowledge by the employment of a close teacher-pupil contact of a large group of surgeons. The goal of the study presented here was to evaluate the satisfaction and benefits of the practical course for visceral surgery in Warnemünde after 10 years of course experience.

MATERIAL AND METHODS

All participants in the annual course for visceral surgery were included since 1999. During this 1-week course conventional and laparoscopic exercises are performed under direct guidance of an experienced tutor. The participants are divided into 3 groups based on their surgical experience (e.g. <3 years, 3-5 years, >5 years). All participants received a standardised questionnaire before and after successful course completion for the collection of relevant data (e.g. demography, training, surgical experience and course evaluation).

RESULTS

A total of 1,062 participants (435 female, 627 male, mean age 37 years) participated in the course. The average surgical experience of the participants was 5 years. Of the participants 489 came from a hospital of basic medical care, 499 from a hospital of maximum medical care and 74 from a university hospital. Of the participants 96% had no or only little experience with skill courses (1,020 out of 1,065) and 827 participants had no or only few possibilities for training outside of the operation room (78%). The conventional part of the course was evaluated by 77% of the participants as very good and by 50% as very good for the laparoscopic part. Only 8.3% of the participants were willing to finance the costs of the course by themselves.

CONCLUSIONS

The practical course for visceral surgery leads to a subjective success in learning. Participation in the course leads to a high satisfaction and offers a cost-intensive possibility for a standardised surgical training. But there are too few experiences with skill courses and possibilities for surgical training outside the operation room so far.

Total extraperitoneal hernioplasty: does the long-term clinical course depend on the type of mesh?

INTRODUCTION

Implantation of alloplastic material has become a standard surgical procedure in inguinal hernia repair. The properties of different meshes are discussed as determinants of postoperative outcome. The aim of this study was to comparatively evaluate long-term results after total extraperitoneal hernioplasty (TEP) with a heavyweight polypropylene mesh (PP) and a lightweight polypropylene-polyglactin composite mesh (PP-PG) in a large patient population.

MATERIALS AND METHODS

The study included patients who underwent TEP for elective repair of uni- or bilateral inguinal hernias between June 1997 and October 2004. We used a heavyweight PP mesh from June 1997 to February 2001 and a lightweight PP-PG mesh from March 2001 to October 2004. Patient data were evaluated by a prospective online registry, and long-term results were assessed by standardized ad hoc questionnaires after a minimum follow-up of 12 (12-103) months.

RESULTS

Five hundred twenty-two patients aged 18-87 years underwent surgical repair of 655 inguinal hernias, and 370 (70.8%) were evaluated. TEP was performed with PP mesh in 192 cases and with PP-PG mesh in 169 cases. Nine patients died during follow-up; 14.6% (PP) versus 20.1% (PP-PG) patients complained of mild pain, and 8.9% (PP) versus 5.3% (PP-PG) patients reported moderate to severe pain (P > 0.05). Mild dysesthesias occurred in 13.5% of the PP group and 11.8% of the PP-PG group (P = 0.63). Moderate to severe dysesthesias were reported by 6.8% with a heavyweight mesh and by 3.0% with a lightweight mesh (P = 0.10). There were no significant differences with regard to the patients' postoperative return to normal daily activities. The recurrence rate was 5.2% with a PP mesh and 1.8% with a PP-PG mesh (P = 0.08).

CONCLUSIONS

The long-term results after TEP showed no difference between PP and PP-PG meshes with regard to chronic pain, chronic dysesthesias, postoperative daily activities, and recurrence rates.

Increased pontin expression in human colorectal cancer tissue

Wnt signaling plays a fundamental role in the control of cell proliferation and differentiation and is frequently deregulated in colorectal carcinoma leading to an enhanced expression of Wnt target genes. Pontin, a member of the AAA(+) superfamily, has previously been shown to interact with beta-catenin and to enhance TCF/beta-catenin-mediated transcription of Wnt target genes and thus may contribute to carcinogenesis. Here, we studied the expression of pontin in 34 patients with histologically proven colorectal cancer by immunohistochemistry on paraffin-embedded colorectal cancer samples using the monoclonal mouse anti-pontin (5G3-11) antibody. Cytoplasmic pontin staining of tumor cells was present in all cases and was stronger in 84.6% and equal in 15.4% of the cases compared with normal mucosa. In 50% of tumor specimens, an additional nuclear pontin staining pattern was noted with positivity ranging from 10% to 60% of the nuclei. Interestingly, all cases with nuclear pontin expression also revealed nuclear beta-catenin localization. Furthermore, pontin staining was stronger at the invasive margin and in tumor buds than in the tumor center in 41.2% and 37.9% of the cases, respectively. In this context, 66.7% and 64.7% of the cases with enhanced beta-catenin staining at the invasive margin and in tumor buds, respectively, also revealed stronger pontin expression. Analysis of pontin expression in 8 patients by Western blotting confirmed the histologic results. These data suggest that upregulation and nuclear localization of pontin together with beta-catenin may contribute to progression of colorectal carcinoma.