A Single-Cell Atlas of the Tumor and Immune Ecosystem of Human Breast Cancer.

Breast cancer is a heterogeneous disease. Tumor cells and associated healthy cells form ecosystems that determine disease progression and response to therapy. To characterize features of breast cancer ecosystems and their associations with clinical data, we analyzed 144 human breast tumor and 50 non-tumor tissue samples using mass cytometry. The expression of 73 proteins in 26 million cells was evaluated using tumor and immune cell-centric antibody panels. Tumors displayed individuality in tumor cell composition, including phenotypic abnormalities and phenotype dominance. Relationship analyses between tumor and immune cells revealed characteristics of ecosystems related to immunosuppression and poor prognosis. High frequencies of PD-L1+ tumor-associated macrophages and exhausted T cells were found in high-grade ER+ and ER- tumors. This large-scale, single-cell atlas deepens our understanding of breast tumor ecosystems and suggests that ecosystem-based patient classification will facilitate identification of individuals for precision medicine approaches targeting the tumor and its immunoenvironment.

The single-cell pathology landscape of breast cancer.

Single-cell analyses have revealed extensive heterogeneity between and within human tumours1-4, but complex single-cell phenotypes and their spatial context are not at present reflected in the histological stratification that is the foundation of many clinical decisions. Here we use imaging mass cytometry5 to simultaneously quantify 35 biomarkers, resulting in 720 high-dimensional pathology images of tumour tissue from 352 patients with breast cancer, with long-term survival data available for 281 patients. Spatially resolved, single-cell analysis identified the phenotypes of tumour and stromal single cells, their organization and their heterogeneity, and enabled the cellular architecture of breast cancer tissue to be characterized on the basis of cellular composition and tissue organization. Our analysis reveals multicellular features of the tumour microenvironment and novel subgroups of breast cancer that are associated with distinct clinical outcomes. Thus, spatially resolved, single-cell analysis can characterize intratumour phenotypic heterogeneity in a disease-relevant manner, with the potential to inform patient-specific diagnosis.

BRCA promoter methylation in triple-negative breast cancer is preserved in xenograft models and represents a potential therapeutic marker for PARP inhibitors.

PURPOSE: Most triple-negative breast cancers (TNBC) are sporadic in nature and often associated with dysfunction of the BRCA1 or BRCA2 genes. Since somatic BRCA mutations are rare in breast cancer (BC), this dysfunction frequently is the result of BRCA promoter methylation. Despite the phenotypic similarities of these tumors to those with germline or somatic BRCA mutation, the evidence of response to PARP inhibitors is unclear. METHODS: We analyzed the prevalence of BRCA promoter methylation in 29 BC metastases through the well-established Illumina Infinium EPIC Human Methylation Bead Chip. In cases with BRCA methylation, the xenograft of the same tumor was tested. Additionally, we compared BC xenografts with an identified BRCA methylation to their matched primary tumors and subsequently investigated the efficacy of PARP inhibitors on tumor organoids from a BRCA2 promoter-methylated BC. RESULTS: BRCA2 promotor hypermethylation was identified in one pleural metastasis of a young patient as well as in the xenograft tissue. We also identified five more xenograft models with BRCA2 promotor hypermethylation. Analysis of one matched primary tumor confirmed the same BRCA2 methylation. PARP inhibitor treatment of tumor organoids derived from the BRCA2 methylated xenograft tumor tissue of the young patient showed a significant decline in cell viability, similar to organoids with somatic BRCA1 mutation, while having no effect on organoids with BRCA1 wildtype. CONCLUSION: BRCA promotor hypermethylation seems to be a rare event in metastatic BC but is preserved in subsequent xenograft models and might represent an attractive therapeutic marker for PARP inhibitors.

Single-cell Analysis Reveals Inter- and Intratumour Heterogeneity in Metastatic Breast Cancer.

Metastasis is the leading cause of cancer-related deaths of breast cancer patients. Some cancer cells in a tumour go through successive steps, referred to as the metastatic cascade, and give rise to metastases at a distant site. We know that the plasticity and heterogeneity of cancer cells play critical roles in metastasis but the precise underlying molecular mechanisms remain elusive. Here we aimed to identify molecular mechanisms of metastasis during colonization, one of the most important yet poorly understood steps of the cascade. We performed single-cell RNA-Seq (scRNA-Seq) on tumours and matched lung macrometastases of patient-derived xenografts of breast cancer. After correcting for confounding factors such as the cell cycle and the percentage of detected genes (PDG), we identified cells in three states in both tumours and metastases. Gene-set enrichment analysis revealed biological processes specific to proliferation and invasion in two states. Our findings suggest that these states are a balance between epithelial-to-mesenchymal (EMT) and mesenchymal-to-epithelial transitions (MET) traits that results in so-called partial EMT phenotypes. Analysis of the top differentially expressed genes (DEGs) between these cell states revealed a common set of partial EMT transcription factors (TFs) controlling gene expression, including ZNF750, OVOL2, TP63, TFAP2C and HEY2. Our data suggest that the TFs related to EMT delineate different cell states in tumours and metastases. The results highlight the marked interpatient heterogeneity of breast cancer but identify common features of single cells from five models of metastatic breast cancer.

The short- and long-term outcome after the surgical management of common bile duct stones in a tertiary referral hospital.

BACKGROUND: The removal of common bile duct stones by endoscopic retrograde cholangiopancreatography (ERCP) shows excellent results with low complication rates and is therefore considered a gold standard. However, in case of stones non-removable by ERCP, surgical extraction is needed. The surgical approach is still controversial and clinical guidelines are missing. This study aims to analyze the outcomes of patients treated with choledochotomy or hepaticojejunostomy for common bile duct stones. METHODS: All patients who underwent choledochotomy or hepaticojejunostomy for common bile duct stones at a tertiary referral hospital over 11 years were included. The analyzed data contains basic demographics, diagnostics, surgical parameters, length of hospitalization, and morbidity and mortality. RESULTS: Over the study period, 4375 patients underwent cholecystectomy, and 655 received an ERCP with stone extraction, with 48 of these patients receiving subsequent surgical treatment. ERCP was attempted in 23/30 (77%) of the choledochotomy patients pre/intraoperatively and 11/18 (56%) in hepaticojejunostomy patients. The 30-day major complication rate (Clavien-Dindo > II) was 1/30 (3%) in the choledochotomy group and 2/18 (11%) in the hepaticojejunostomy group. Complications after 30 days occurred in 3/30 (10%) patients and 2/18 (11%), respectively, and no mortality occurred. CONCLUSION: ERCP should still be considered the gold standard, although due to low short- and long-term morbidity rates, choledochotomy and hepaticojejunostomy represent effective surgical solutions for common bile duct stones.

High ratio of pCXCR4/CXCR4 tumor infiltrating immune cells in primary high grade ovarian cancer is indicative for response to chemotherapy.

BACKGROUND: Ovarian cancer (OC) is the fifth most common malignant female cancer with a high mortality, mainly because of aggressive high-grade serous carcinomas (HGSOC), but also due to absence of specific early symptoms and effective detection strategies. The CXCL12-CXCR4 axis is considered to have a prognostic impact and to serve as potential therapeutic target. Therefore we investigated the role of pCXCR4 and CXCR4 expression of the tumor cells and of tumor infiltrating immune cells (TIC) in high-grade serous OC and their association with the recurrence-free (RFS) and overall survival (OS). METHODS: A tissue microarray of 47 primary high grade ovarian serous carcinomas and their recurrences was stained with primary antibodies directed against CXCR4 and pCXCR4. Beside the evaluation of the absolute tumor as well as TIC expression in primary and recurrent cancer biopsies the corresponding ratios for pCXCR4 and CXCR4 were generated and analyzed. The clinical endpoints were response to chemotherapy, OS as well as RFS. RESULTS: Patients with a high pCXCR4/CXCR4 TIC ratio in primary cancer biopsies showed a significant longer RFS during the first two years (p = 0.025). However, this effect was lost in the long-term analysis including a follow-up period of 5 years (p = 0.128). Interestingly, the Multivariate Cox regression analysis showed that a high pCXCR4/CXCR4 TIC ratio in primary cancer independently predicts longer RFS (HR 0.33; 95CI 0.13 - 0.81; p = 0.015). Furthermore a high dichotomized distribution of CXCR4 positive tumor expression in recurrent cancer biopsies showed a significantly longer 6-month RFS rate (p = 0.018) in comparison to patients with low CXCR4 positive tumor expression. However, this effect was not independent of known risk factors in a Multivariate Cox regression (HR 0.57; 95CI 0.24 - 1.33; p = 0.193). CONCLUSIONS: To the best of our knowledge we show for the first time that a high pCXCR4/CXCR4 TIC ratio in primary HGSOC biopsies is indicative for better RFS and response to chemotherapy. HIGHLIGHTS: • We observed a significant association between high pCXCR4/CXCR4 TIC ratio and better RFS in primary cancer biopsies, especially during the early postoperative follow-up and independent of known risk factors for recurrence. • High CXCR4 tumor expression in recurrent HGSOC biopsies might be indicative for sensitivity to chemotherapy. We found evidence that at the beginning of the disease (early follow-up) the role of the immune response seems to be the most crucial factor for progression. On the other hand in recurrent/progressive disease the biology of the tumor itself becomes more important for prognosis. • We explored for the first time the predictive and prognostic role of pCXCR4/CXCR4 TIC ratio in high-grade serous ovarian cancer.

Incidence of Liver Resection Following the Introduction of Caseload Requirements for Liver Surgery in Switzerland.

BACKGROUND: Centralization of care is an established concept in complex visceral surgery. Switzerland introduced case load requirements (CR) in 2013 in five areas of cancer surgery. The current study investigates the effects of CR on indication and mortality in liver surgery. METHODS: This is a retrospective analysis of a complete national in-hospital data set including all admissions between January 1, 2005, and December 31, 2015. Primary outcome variables were the incidence proportion and the 60-day in-hospital mortality of liver resections. Incidence proportion was calculated as the overall yearly number of liver resections performed in relation to the population living in Switzerland before and after the introduction of CR. RESULTS: Our analysis shows an increase number of liver resections compared to the period before introduction of CR from 2005-2012 (4.67 resections/100,000) to 2013-2015 (5.32 resections/100,000) after CR introduction. Age-adjusted incidence proportion increased by 14% (OR 1.14 95 CI [1.07-1.22]). National in-hospital mortality remained stable before and after CR (4.1 vs 3.7%), but increased in high-volume institutions (3.6 vs 5.6%). The number of hospitals performing liver resections decreased after the introduction of CR from 86 to 43. Half of the resections were performed in institutions reaching the stipulated numbers (53% before vs 49% after introduction of CR). After implementation of CR, patients undergoing liver surgery had more comorbidities (88 vs 92%). CONCLUSION: The introduction of CR for liver surgery in Switzerland in 2013 was accompanied by an increase in operative volume with limited effects on centralization of care.

Persistent acute cholecystitis after cholecystostomy - increased mortality due to treatment approach?

BACKGROUND: Percutaneous cholecystostomy (PC) is a treatment option for acute cholecystitis (AC) in cases where cholecystectomy (CCY) is not feasible due to limited health conditions. The use of PC remains questionable. The aim was to retrospectively analyse the outcome of patients after PC. METHODS: All patients who underwent PC for AC at a tertiary referral hospital over 10 years were included. Descriptive statistics, analysed mortality with and without CCY after PC, and a multivariable logistic regression for potential confounder and a landmark sensitivity analysis for immortal time bias were used. RESULTS: Of 158 patients, 79 were treated with PC alone and 79 had PC with subsequent CCY. Without CCY, 48% (38 patients) died compared to 9% with CCY. In the multivariable analysis CCY was associated with 85% lower risk of mortality. The landmark analysis was compatible with the main analyses. Direct PC-complications occurred in 17% patients. Histologically, 22/75 (29%) specimens showed chronic cholecystitis, and 76% AC. CONCLUSION: Due to the high mortality rate of PC alone, performing up-front CCY is proposed. PC represents no definitive treatment for AC and should remain a short-term solution because of the persistent inflammatory focus. According to these findings, almost all specimens showed persistent inflammation.

Nestin and CD34 expression in colorectal cancer predicts improved overall survival.

BACKGROUND: Nestin, a class VI intermediate filament protein of the cytoskeleton, and CD34, a transmembrane phosphoglycoprotein, are markers of progenitor cells. This study aimed to evaluate their expression and clinical significance in colorectal cancer. METHODS: A clinically annotated tissue microarray, including 599 patients with colorectal cancer, was analyzed by immunohistochemistry. Furthermore, nestin and CD34 correlations with HIF-1a and a panel of cytokines and chemokines were assessed using quantitative reverse transcription PCR and The Cancer Genome Atlas dataset. RESULTS: Expression of nestin and CD34 was observed only in the tumor stroma. Patients displaying high expression of nestin and CD34 demonstrated higher rates of T1 and T2 tumors (p = .020), lower vascular invasion (p < .001) and improved 5-year overall survival (65%; 95% CI = 55-73 vs 45%; 95% CI = 37-53) after adjusting for clinicopathological characteristics (HR: 0.67; 95% CI = 0.46-0.96). A moderate to strong correlation (r = 0.37-0.78, p < .03) of nestin and CD34 was demonstrated for the following markers; HIF-1α, CD4, CD8, FOXP3, IRF1, GATA3, CCL2, CCL3, CXCL12 and CCL21. CONCLUSIONS: Combined expression of nestin and CD34 expression is associated with better overall survival possibly by modulating a favorable immune response.

Dynamic Serosal Perfusion Assessment during Colorectal Resection Using Visible Light Spectroscopy.

INTRODUCTION: Anastomotic leakage (AL) in colorectal surgery occurs with an incidence of up to 20%. Bowel perfusion is deemed to be one of the most important factors for anastomotic healing. However, not much is known about its variability during colorectal surgery and its impact on the outcome. Therefore, this study aims to evaluate serosal oxygen saturation patterns during colorectal resections with visible light spectroscopy (VLS). MATERIALS AND METHODS: Bowel perfusion in patients undergoing left-sided colorectal resections was assessed at different timepoints during surgery using VLS on the colonic serosa. The primary outcome parameter was serosal oxygen saturation (StO2) at the anastomosis during different timepoints of surgery. RESULTS: We included 50 patients who underwent colorectal resection for bowel cancer (58%) and diverticular disease (34%). StO2 at the proximal site of the anastomosis increased significantly throughout the surgery (mean difference 3.61%; 95% CI -6.22 to -1.00; p = 0.008). However, aberrancy from this identified perfusion pattern had no impact on the postoperative outcome. CONCLUSION: During colorectal resections, we could demonstrate an increase of the colonic StO2 throughout surgery. Appearance of AL was not associated with lower StO2, underlining the multifactorial genesis of developing AL.

[Primary Liver Cancers - Hepatocellular Carcinoma and Cholangiocarcinoma]. / Lebereigene Tumoren ­ Hepatozelluläres und das Cholangiozelluläre Karzinom.

Primary Liver Cancers - Hepatocellular Carcinoma and Cholangiocarcinoma Abstract. Malignant liver tumors are often discovered as an incidental finding on sonography. Hepatocellular carcinoma (HCC) is the most common primary liver malignancy, followed by cholangiocellular carcinoma (CCC). The most employed diagnostic tests are MRI with gadolinium contrast medium or 3-phase CT abdomen. Biopsy of a hepatic nodule can be omitted if the radiologic and clinical presentation are typical. Patients with malignant liver tumors and / or unclear findings should present to a liver center. The most effective therapies for HCC and CCC include liver resection and liver transplantation. Only surgical oncologic R0 resection is curative. The therapy should be done by a multidisciplinary team. If primary surgery of the lesion is not possible, interventional or sytemic chemotherapy can also be helpful.

Infiltration by myeloperoxidase-positive neutrophils is an independent prognostic factor in breast cancer.

PURPOSE: Myeloperoxidase (MPO) is an enzyme secreted by neutrophil granulocytes as a result of phagocytosis during inflammation. In colorectal cancer, tumour infiltration by MPO expressing cells has been shown to be independently associated with a favourable prognosis. In this study, we explored the role of MPO-positive cell infiltration and its prognostic significance in invasive breast cancer. METHODS: We performed immunohistochemical staining for MPO on multiple tissue microarrays comprising a total of 928 human breast cancer samples with detailed clinical-pathological annotation and outcome data. RESULTS: MPO-positive cell infiltration (≥ 5 cells/tissue punch) was found in 150 (16%) of the 928 evaluable breast cancer cases. In univariate survival analyses, infiltration by MPO-positive cells was associated with a significantly better overall survival (p < 0.001). In subset univariate analyses, the infiltration by MPO-positive cells was associated with significantly better overall survival in the Luminal B/HER2-negative subtype (p = 0.005), the HER2 enriched subtype (p = 0.011), and the Triple Negative subtype (p < 0.001). In multivariate analysis, MPO expression proved to be an independent prognostic factor for improved overall survival (p < 0.001). CONCLUSIONS: This is the first study to show that infiltration of MPO-positive cells is an independent prognostic biomarker for improved overall survival in human breast cancer.

Expression of RET is associated with Oestrogen receptor expression but lacks prognostic significance in breast cancer.

BACKGROUND: The Rearranged during Transfection (RET) protein is overexpressed in a subset of Estrogen Receptor (ER) positive breast cancer, with both signalling pathways functionally interacting. This cross-talk plays a pivotal role in the resistance of breast cancer cells to anti-endocrine therapies, and RET expression is assumed to correlate with poor prognosis based on findings in small patient cohorts. The aim of our study was to investigate the impact of RET expression on patient outcome in human breast cancer. METHODS: We performed an immunohistochemical analysis of RET protein expression on a tissue microarray encompassing 990 breast cancer patients and correlated its expression with clinicopathological parameters and survival data. RESULTS: Expression of RET was detected in 409 out of 990 cases (41.3%). RET and ER expression significantly correlated (p < 0.0001). The Luminal B HER2-positive subtype showed the highest expression rate (48.9%). In univariate and multivariate survival analyses, RET expression had no impact on overall survival. CONCLUSION: We confirmed the co-expression of RET and ER, but we did not find RET expression to be an independent prognostic factor in human breast cancer. Clinical trials with newly developed RET inhibitors are needed to evaluate if RET inhibition has a beneficial impact on patient survival in ER positive breast cancer.

Endoscopic Superficialisation of Haemodialysis Arteriovenous Fistulas in Obese Patients - Safety, Feasibility, and Outcomes.

OBJECTIVE: The aim was to evaluate the safety and feasibility of endoscopic superficialisation (ES) in patients with deeply located cephalic veins in well matured arteriovenous fistulae (AVF) and to present functional outcomes. METHODS: All patients with cannulation difficulties due to a deep lying cephalic vein of more than 6 mm but with an otherwise matured AVF with a straight needle access segment of at least 6 cm were included in this retrospective study. Procedure related safety, defined as completion of ES with no need for conversion to open surgery, and feasibility in terms of cephalic vein depth reduction were assessed. The primary endpoint was three successfully performed haemodialysis sessions using the endoscopically superficialised AVF during a minimum follow up of 12 months. RESULTS: From June 2013 to August 2017, 12 patients with a mean body mass index of 33.5 ± 3.9 kg/m2 underwent ES as a second stage procedure following radiocephalic (n = 5) or brachiocephalic AVF (n = 7) creation. All procedures were conducted endoscopically. Ultrasound imaging 12 weeks post-operatively documented a reduction in the depth of the cephalic vein from a mean of 10.1 ± 1.4 mm to 4.3 ± 0.8 mm. The mean duration of the ES was 69 ± 26.0 min with 67% performed under locoregional anaesthesia. In all but one patient with a cephalic vein of poor wall quality leading to recurrent haematoma, haemodialysis was performed successfully following ES. CONCLUSIONS: Endoscopic superficialisation of the cephalic vein is a safe and effective technique. Providing good functional results, ES represents an alternative approach for second stage superficialisation in obese patients.

Antimicrobial Prophylaxis Redosing Reduces Surgical Site Infection Risk in Prolonged Duration Surgery Irrespective of Its Timing.

BACKGROUND: Long-duration surgery requires repeated administration of antimicrobial prophylaxis (amp). Amp "redosing" reduces incidence of surgical site infections (SSI) but is frequently omitted. Clinical relevance of redosing timing needs to be investigated. Here, we evaluated the effects of compliance with amp redosing and its timing on SSI incidence in prolonged duration surgery. METHODS: Data from >9000 patients undergoing visceral, trauma, or vascular surgery with elective or emergency treatment in two tertiary referral Swiss hospitals were analyzed. All patients had to receive amp preoperatively and redosing, if indicated. Antibiotics used were cefuroxime (1.5 or 3 g, if weight >80 kg), or cefuroxime and metronidazole (1.5 and 0.5 g, or 3 and 1 g doses, if weight >80 kg). Alternatively, in cases of known or suspected allergies, vancomycin (1 g), gentamicin (4 mg/Kg), and metronidazole or clindamycin (300 mg) with or without ciprofloxacin (400 mg) were used. Association of defined parameters, including wound class, ASA scores, and duration of operation, with SSI incidence was explored. RESULTS: In the whole cohort, SSI incidence significantly correlated with duration of surgery (ρ = 0.73, p = 0.031). In 593 patients undergoing >240 min long interventions, duration of surgery was the only parameter significantly (p < 0.001) associated with increased SSI risk, whereas wound class, ASA scores, treatment areas, and emergency versus elective hospital entry were not. Redosing significantly reduced SSI incidence as shown by multivariate analysis (OR 0.60, 95% CI 0.37-0.96, p = 0.034), but exact timing had no significant impact. CONCLUSIONS: Long-duration surgery associates with higher SSI incidence. Irrespective of its exact timing, amp redosing significantly decreases SSI risk.

Oncoplastic Breast Consortium consensus conference on nipple-sparing mastectomy.

PURPOSE: Indications for nipple-sparing mastectomy (NSM) have broadened to include the risk reducing setting and locally advanced tumors, which resulted in a dramatic increase in the use of NSM. The Oncoplastic Breast Consortium consensus conference on NSM and immediate reconstruction was held to address a variety of questions in clinical practice and research based on published evidence and expert panel opinion. METHODS: The panel consisted of 44 breast surgeons from 14 countries across four continents with a background in gynecology, general or reconstructive surgery and a practice dedicated to breast cancer, as well as a patient advocate. Panelists presented evidence summaries relating to each topic for debate during the in-person consensus conference. The iterative process in question development, voting, and wording of the recommendations followed the modified Delphi methodology. RESULTS: Consensus recommendations were reached in 35, majority recommendations in 24, and no recommendations in the remaining 12 questions. The panel acknowledged the need for standardization of various aspects of NSM and immediate reconstruction. It endorsed several oncological contraindications to the preservation of the skin and nipple. Furthermore, it recommended inclusion of patients in prospective registries and routine assessment of patient-reported outcomes. Considerable heterogeneity in breast reconstruction practice became obvious during the conference. CONCLUSIONS: In case of conflicting or missing evidence to guide treatment, the consensus conference revealed substantial disagreement in expert panel opinion, which, among others, supports the need for a randomized trial to evaluate the safest and most efficacious reconstruction techniques.

Impact of a Surgical Sealing Patch on Lymphatic Drainage After Axillary Dissection for Breast Cancer: The SAKK 23/13 Multicenter Randomized Phase III Trial.

BACKGROUND: Several studies and a meta-analysis showed that fibrin sealant patches reduced lymphatic drainage after various lymphadenectomy procedures. Our goal was to investigate the impact of these patches on drainage after axillary dissection for breast cancer. METHODS: In a phase III superiority trial, we randomized patients undergoing breast-conserving surgery at 14 Swiss sites to receive versus not receive three large TachoSil® patches in the dissected axilla. Axillary drains were inserted in all patients. Patients and investigators assessing outcomes were blinded to group assignment. The primary endpoint was total volume of drainage. RESULTS: Between March 2015 and December 2016, 142 patients were randomized (72 with TachoSil® and 70 without). Mean total volume of drainage in the control group was 703 ml [95% confidence interval (CI) 512-895 ml]. Application of TachoSil® did not significantly reduce the total volume of axillary drainage [mean difference (MD) -110 ml, 95% CI -316 to 94, p = 0.30]. A total of eight secondary endpoints related to drainage, morbidity, and quality of life were not improved by use of TachoSil®. The mean total cost per patient did not differ significantly between the groups [34,253 Swiss Francs (95% CI 32,625-35,880) with TachoSil® and 33,365 Swiss Francs (95% CI 31,771-34,961) without, p = 0.584]. In the TachoSil® group, length of stay was longer (MD 1 day, 95% CI 0.3-1.7, p = 0.009), and improvement of pain was faster, although the latter difference was not significant [2 days (95% CI 1-4) vs. 5.5 days (95% CI 2-11); p = 0.2]. CONCLUSIONS: TachoSil® reduced drainage after axillary dissection for breast cancer neither significantly nor relevantly.

High-resolution standardization reduces delay due to workflow disruptions in laparoscopic cholecystectomy.

BACKGROUND: Optimal resource utilization in high-cost environments like operating theatres is fundamental in today's cost constrained health care systems. Interruptions of the surgical workflow, i.e. microcomplications (MC), lead to prolonged procedure times and higher costs and can be indicative of surgical mistakes. Reducing MC can improve operating room efficiency and prevent intraoperative complications. We, therefore, aimed to evaluate the impact of a high-resolution standardized laparoscopic cholecystectomy protocol (HRSL) on operative time and intraoperative interruptions in a teaching hospital. METHODS: HRSL consisted of a detailed stepwise protocol for the procedure, supported by a teaching video, both to be reviewed as mandatory preparation by each team member before surgery. Audio-video records of laparoscopic cholecystectomies were reviewed regarding type, frequency and duration of MC before and after implementation of HRSL. RESULTS: Thirty-nine (20 control and 19 HRSL) audio-video records of laparoscopic cholecystectomies with a total duration of 51.36 h (28.92 pre 22.44 post) were reviewed. The majority of operations (86%) were performed by teams who had completed less than 10 procedures together previously. Communication-related interruptions and instrument changes accounted for the majority of MC. Median frequency and duration of MC were 95 events/h and 15.6 min/h, respectively, of surgery pre-intervention. With HRSL this was reduced to 76 events/h and 10.6 min/h of operating. In multivariable analysis, HRSL was an independent predictor for shorter delay and lower frequency of MC [percentage decrease 27% (95% CI 18-35%), resp. 30% (95% CI 19-40%)]. Procedure-related risk factors for the longer delay due to MC in multivariable analysis were less experience of the surgeon and intraoperative adhesiolysis. CONCLUSIONS: HRSL is effective in reducing delays due to MC in a teaching institution with limited team experience. These findings should be tested in larger potentially cluster-randomized controlled trials. The trial has been registered with clinicaltrials.gov: NCT03329859.

Associations of Hospital Length of Stay with Surgical Site Infections.

BACKGROUND: Surgical site infections (SSI) are a major cause of morbidity and mortality in surgical patients. Postoperative and total hospital length of stay (LOS) are known to be prolonged by the occurrence of SSI. Preoperative LOS may increase the risk of SSI. This study aims at identifying the associations of pre- and postoperative LOS in hospital and intensive care with the occurrence of SSI. METHODS: This observational cohort study includes general, orthopedic trauma and vascular surgery patients at two tertiary referral centers in Switzerland between February 2013 and August 2015. The outcome of interest was the 30-day SSI rate. RESULTS: We included 4596 patients, 234 of whom (5.1%) experienced SSI. Being admitted at least 1 day before surgery compared to same-day surgery was associated with a significant increase in the odds of SSI in univariate analysis (OR 1.65, 95% CI 1.25-2.21, p < 0.001). More than 1 day compared to 1 day of preoperative hospital stay did not further increase the odds of SSI (OR 1.08, 95% CI 0.77-1.50, p = 0.658). Preoperative admission to an intensive care unit (ICU) increased the odds of SSI as compared to hospital admission outside of an ICU (OR 2.19, 95% CI 0.89-4.59, p = 0.057). Adjusting for potential confounders in multivariable analysis weakened the effects of both preoperative admission to hospital (OR 1.38, 95% CI 0.99-1.93, p = 0.061) and to the ICU (OR 1.89, 95% CI 0.73-4.24, p = 0.149). CONCLUSION: There was no significant independent association between preoperative length of stay and risk of SSI while SSI and postoperative LOS were significantly associated.

First international consensus conference on standardization of oncoplastic breast conserving surgery.

PURPOSE: To obtain consensus recommendations for the standardization of oncoplastic breast conserving surgery (OPS) from an international panel of experts in breast surgery including delegates from the German, Austrian and Swiss societies of senology. METHODS: A total of 52 questions were addressed by electronic voting. The panel's recommendations were put into context with current evidence and the report was circled in an iterative open email process until consensus was obtained. RESULTS: The panelists considered OPS safe and effective for improving aesthetic outcomes and broadening the indication for breast conserving surgery (BCS) towards larger tumors. A slim majority believed that OPS reduces the rate of positive margins; however, there was consensus that OPS is associated with an increased risk of complications compared to conventional BCS. The panel strongly endorsed patient-reported outcomes measurement, and recommended selected scales of the Breast-Q™-Breast Conserving Therapy Module for that purpose. The Clough bi-level classification was recommended for standard use in clinical practice for indicating, planning and performing OPS, and the Hoffmann classification for surgical reports and billing purposes. Mastopexy and reduction mammoplasty were the only two recognized OPS procedure categories supported by a majority of the panel. Finally, the experts unanimously supported the statement that every OPS procedure should be tailored to each individual patient. CONCLUSIONS: When implemented into clinical practice, the panel recommendations may improve safety and effectiveness of OPS. The attendees agreed that there is a need for prospective multicenter studies to optimize patient selection and for standardized criteria to qualify and accredit OPS training centers.