Actionable absolute risk prediction of atherosclerotic cardiovascular disease based on the UK Biobank.

Cardiovascular diseases (CVDs) are the primary cause of all death globally. Timely and accurate identification of people at risk of developing an atherosclerotic CVD and its sequelae is a central pillar of preventive cardiology. One widely used approach is risk prediction models; however, currently available models consider only a limited set of risk factors and outcomes, yield no actionable advice to individuals based on their holistic medical state and lifestyle, are often not interpretable, were built with small cohort sizes or are based on lifestyle data from the 1960s, e.g. the Framingham model. The risk of developing atherosclerotic CVDs is heavily lifestyle dependent, potentially making many occurrences preventable. Providing actionable and accurate risk prediction tools to the public could assist in atherosclerotic CVD prevention. Accordingly, we developed a benchmarking pipeline to find the best set of data preprocessing and algorithms to predict absolute 10-year atherosclerotic CVD risk. Based on the data of 464,547 UK Biobank participants without atherosclerotic CVD at baseline, we used a comprehensive set of 203 consolidated risk factors associated with atherosclerosis and its sequelae (e.g. heart failure). Our two best performing absolute atherosclerotic risk prediction models provided higher performance, (AUROC: 0.7573, 95% CI: 0.755-0.7595) and (AUROC: 0.7544, 95% CI: 0.7522-0.7567), than Framingham (AUROC: 0.680, 95% CI: 0.6775-0.6824) and QRisk3 (AUROC: 0.725, 95% CI: 0.7226-0.7273). Using a subset of 25 risk factors identified with feature selection, our reduced model achieves similar performance (AUROC 0.7415, 95% CI: 0.7392-0.7438) while being less complex. Further, it is interpretable, actionable and highly generalizable. The model could be incorporated into clinical practice and might allow continuous personalized predictions with automated intervention suggestions.

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.

Abdominal Decompression after Cardiac Surgery: Outcome of 42 Patients with Abdominal Compartment Syndrome.

BACKGROUND: Up to 50% of patients in intensive care units develop intraabdominal hypertension (IAH) in the course of medical treatment. If not detected on time and treated adequately, IAH may develop into an abdominal compartment syndrome (ACS) which is associated with a high mortality rate. Patients undergoing cardiac surgery are especially prone to develop ACS due to several risk factors including intraoperative hypothermia, fluid resuscitation and acidosis. We investigated patients who developed ACS after cardiac surgery and analyzed potential risk factors, treatment and outcome. METHODS: From 2011 to 2016, patients with ACS after cardiac surgery requiring decompressive laparotomy were prospectively recorded. Patient characteristics, details on the cardiac surgery, mortality rate and type of treatment of the open abdomen were analyzed. RESULTS: Incidence of ACS in cardiac surgery patients was 1.0% (n = 42/4128), with a mortality rate of 57%. Ejection fraction, Euroscore2 as well as the perfusion time are independent risk factors for the development of ACS. The outcome of patients with ACS was independent of elective versus emergency surgery, gender, age, BMI or ASA score. In the 18 surviving patients, fascial closure was achieved in 72% after a median of 9 days. CONCLUSION: Abdominal compartment syndrome is a rare but serious complication after cardiac surgery with a high mortality rate. Independent risk factors for ACS were identified. Negative pressure wound therapy seems to promote and allow early fascia closure of the abdomen and represents therefore a likely benefit for the patient.

Teaching in the operating room: A risk for surgical site infections?

BACKGROUND/AIM: To investigate whether teaching procedures and surgical experience are associated with surgical site infection (SSI) rates. METHODS: This prospective cohort study of patients undergoing general, orthopedic trauma and vascular surgery procedures was done between 2012 and 2015 at two tertiary care hospitals in Switzerland/Europe. RESULTS: Out of a total of 4560 patients/surgeries, 1403 (30.8%) were classified as teaching operations. The overall SSI rate was 5.1% (n = 233). Teaching operations (OR 0.78, 95% CI 0.57-1.07, p = 0.120), junior surgeons (OR 0.80, 95% CI 0.55-1.15, p = 0.229) and surgical experience (OR 0.997, 95% CI 0.982-1.012, p = 0.676) were overall not independently associated with the odds of SSI. However, for surgeons' seniority and experience, these associations depended on the duration of surgery. CONCLUSIONS: In procedures of shorter and medium duration, teaching procedures and junior as well as less experienced surgeons are not independently associated with increased odds of SSI.

Perioperative Tablet-Based Telemonitoring After Abdominal Wall Hernia Surgery: Pilot Prospective Observational Cohort Study.

BACKGROUND: Hernia repairs account for millions of general surgical procedures performed each year worldwide, with a notable shift to outpatient settings over the last decades. As technical possibilities such as smartphones, tablets, and different kinds of probes are becoming more and more available, such systems have been evaluated for applications in various clinical settings. However, there have been few studies conducted in the surgical field, especially in general surgery. OBJECTIVE: We aimed to assess the feasibility of a tablet-based follow up to monitor activity levels after repair of abdominal wall hernias and to evaluate a possible reduction of adverse events by their earlier recognition. METHODS: Patients scheduled for elective surgical repair of minor abdominal wall hernias (eg, inguinal, umbilical, or trocar hernias) were equipped with a telemonitoring system, including a tablet, pulse oximeter, and actimeter, for a monitoring phase of 7 days before and 30 days after surgery. Descriptive statistical analyses were performed. RESULTS: We enrolled 16 patients with a mean overall age of 48.75 (SD 16.27) years. Preoperative activity levels were reached on postoperative day 12 with a median of 2242 (IQR 0-4578) steps after plunging on the day of surgery. The median proportion of available activity measurements over the entire study period of 38 days was 69% (IQR 56%-81%). We observed a gradual decrease in the proportion of available data for all parameters during the postoperative course. Six out of ten patients (60%) regained preoperative activity levels within 3 weeks after surgery. Overall, patients rated the usability of the system as relatively easy. CONCLUSIONS: Tablet-based follow up is feasible after surgical repair of minor abdominal wall hernias, with good adherence rates during the first couple of weeks after surgery. Thus, such a system could be a useful tool to supplement or even replace traditional outpatient follow up in selected general surgical patients.

Smaller Inguinal Hernias are Independent Risk Factors for Developing Chronic Postoperative Inguinal Pain (CPIP): A Registry-based Multivariable Analysis of 57, 999 Patients.

OBJECTIVE: Impact of inguinal hernia defect size as stratified by the European Hernia Society (EHS) classification I to III on the rate of chronic postoperative inguinal pain (CPIP). BACKGROUND: CPIP is the most important complication after inguinal hernia repair. The impact of hernia defect size according to the EHS classification on CPIP is unknown. METHODS: In total, 57,999 male patients from the Herniamed registry undergoing primary unilateral inguinal hernia repair including a 1-year follow-up were selected between September 1, 2009 and November 30, 2016. Using multivariable analysis, the impact of EHS inguinal hernia classification (EHS I vs EHS II vs EHS III and/or scrotal) on developing CPIP was investigated. RESULTS: Multivariable analysis revealed for smaller inguinal hernias a significant higher rate of pain at rest [EHS I vs EHS II: odds ratio, OR = 1.350 (1.180-1.543), P < 0.001; EHS I vs EHS III and/or scrotal: OR = 1.839 (1.504-2.249), P < 0.001; EHS II vs EHS III and/or scrotal: OR = 1.363 (1.125-1.650), P = 0.002], pain on exertion [EHS I vs EHS II: OR = 1.342 (1.223-1.473), P < 0.001; EHS I vs EHS III and/or scrotal: OR = 2.002 (1.727-2.321), P < 0.001; EHS II vs EHS III and/or scrotal: OR = 1.492 (1.296; 1.717), P < 0.001], and pain requiring treatment [EHS I vs EHS II: OR = 1.594 (1.357-1.874), P < 0.001; EHS I vs EHS III and/or scrotal: OR = 2.254 (1.774-2.865), P < 0.001; EHS II vs EHS III and/or scrotal: OR = 1.414 (1.121-1.783), P = 0.003] at 1-year follow-up. Younger patients (<55 y) revealed higher rates of pain at rest, pain on exertion, and pain requiring treatment (each P < 0.001) with a significantly trend toward higher rates of pain in smaller hernias. CONCLUSIONS: Smaller inguinal hernias have been identified as an independent patient-related risk factor for developing CPIP.

[Diagnostic algorithm "FAI and sports hernia" : Results of the consensus meeting for groin pain in athletes]. / Diagnostik-Algorithmus Grenzbereich "FAI und Sportlerleiste" : Ergebnisse des Konsensustreffens Leistenschmerz beim Sportler.

As a result of the complexity and diversity of diseases in the region of the groin, differentiation of the various soft-tissue and bone pathologies remains a challenge for differential diagnosis in routine clinical practice. In the case of athletes with pain localized in the area of the groin, femoroacetabular impingement (FAI) and athlete's groin must be considered as important causes of the groin pain, whereby the common occurrence of double pathologies further complicates diagnosis. Despite the importance of groin pain and its differential diagnoses in everyday clinical practice, there has been a lack of recognized recommendations for diagnostic procedure to date. To this end, a consensus meeting was held in February 2017, in which a group composed equally of groin and hip surgeons took part. With the formulation of recommendations and the establishment of a practicable diagnostic path, colleagues that are involved in treating such patients should be sensitized to this issue and the quality of the diagnosis of groin pain improved in routine clinical practice.

Introduction of a Pathophysiology-Based Diagnostic Decision Support System and Its Potential Impact on the Use of AI in Healthcare.

Many currently available Diagnostic Decision Support Systems (DDSS) are based on causal condition-symptom relations that exhibit certain shortcomings. Ada's new approach explores the capabilities of DDSS based on pathophysiology, describing a disease as a dynamically evolving process. We generated a pathophysiology model for 8 conditions and 68 findings suitable to assess this approach. Preliminary results meet our expectations while leaving space for further improvement.

Introduction of a Pathophysiology-Based Diagnostic Decision Support System.

Many current Clinical Decision Support Systems which assist clinical diagnosis, are based on a causal condition-symptom relation. To reach more diagnostic precision Ada's Deep Reasoning is substituting this approach with the use of a model based on pathophysiology.

Adherence to the WHO surgical safety checklist: an observational study in a Swiss academic center.

BACKGROUND: The World Health Organization (WHO) Surgical Safety Checklist is used globally to ensure patient safety during surgery. Two years after its implementation in the University Hospital Basel's operating rooms, adherence to the protocol was evaluated. METHODS: This mixed method observational study took place in the surgical department of the University Hospital of Basel, Switzerland from April to August 2017. Data collection was via individual structured interviews with selected OR team members regarding checklist adherence and on-site non-participant observations of Team Time Out and Team Sign Out sequences in the OR. Data were subjected to thematic analysis and descriptive statistics compiled. RESULTS: Comprehensive local expert interviews indicated that individual, procedural and contextual variables influenced the application of the checklist. Facilitating factors included well-informed specialists who advocated the use of the Checklist, as well as teams focused on the checklist's intended process and on its content. In contrast, factors such as staff insecurity, a generally negative attitude towards the checklist, a lack of teamwork, and hesitance to complete the checklist, hindered its implementation.The checklist's application was evaluated in 104 on-site observations comprising of 72 Team Time Out (TTO) and 32 Team Sign Out (TSO) sections. Adherence to the protocol ranged between 96 and 100% in TTO and 22% in TSO respectively. Lack of implementation of the TSO was mainly due to the absence of one of the key OR team members, who were busy with other tasks or no longer present in the operating room. CONCLUSION: The study illustrates factors, which foster and hinder consistent application of the WHO surgical safety checklist namely individual, procedural and contextual. It also demonstrates that the TTO was consistently and correctly applied, while the unavailability of key OR team members at sign-out time was the most common reason for omission or incomplete use of the TSO.

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.

The association of surgical drains with surgical site infections - A prospective observational study.

BACKGROUND: Surgical drains are widely used despite limited evidence in their favor. This study describes the associations between drains and surgical site infections (SSI). METHODS: This prospective observational double center study was performed in Switzerland between February 2013 and August 2015. RESULTS: The odds of SSI in the presence of drains were increased in general (OR 2.41, 95%CI 1.32-4.30, p = 0.004), but less in vascular and not in orthopedic trauma surgery. In addition to the surgical division, the association between drains and SSI depended significantly on the duration of surgery (p = 0.01) and wound class (p = 0.034). Furthermore, the duration of drainage (OR 1.24, 95%CI 1.15-1.35, p < 0.001), the number (OR 1.74, 95%CI 1.09-2.74, p = 0.019) and type of drains (open versus closed: OR 3.68, 95%CI 1.88, 6.89, p < 0.001) as well as their location (overall p = 0.002) were significantly associated with SSI. CONCLUSIONS: The general use of drains is discouraged. However, drains may be beneficial in specific surgical procedures.

Outcome of laparoscopic paraesophageal hernia repair in octogenarians: a registry-based, propensity score-matched comparison of 360 patients.

BACKGROUND: Paraesophageal hernias (PEH) tend to occur in elderly patients and the assumed higher morbidity of PEH repair may dissuade clinicians from seeking a surgical solution. On the other hand, the mortality rate for emergency repairs shows a sevenfold increase compared to elective repairs. This analysis evaluates the complication rates after elective PEH repair in patients 80 years and older in comparison with younger patients. METHODS: In total, 3209 patients with PEH were recorded in the Herniamed Registry between September 1, 2009 and January 5, 2018. Using propensity score matching, 360 matched pairs were formed for comparative analysis of general, intraoperative, and postoperative complication rates in both groups. RESULTS: Our analysis revealed a disadvantage in general complications (6.7% vs. 14.2%; p = 0.002) for patients ≥ 80 years old. No significant differences were found between the two groups for intraoperative (4.7% vs. 5.8%, p = 0.627) and postoperative complications (2.2% vs. 2.8%, p = 0.815) or for complication-related reoperations (1.7% vs. 2.2%, p = 0.791). CONCLUSIONS: Despite a higher risk of general complications, PEH repair in octogenarians is not in itself associated with increased rates of intraoperative and postoperative complications or associated reoperations. Therefore, PEH repair can be safely offered to elderly patients with symptomatic PEH, if general medical risk factors are controlled.

Is antibiotic prophylaxis mandatory in laparoscopic incisional hernia repair? Data from the herniamed registry.

BACKGROUND: Several meta-analyses showed that laparoscopic incisional hernia repair is associated with lower surgical site infection (SSI) rates compared to open repair. However, the efficiency of antibiotic prophylaxis (AP) in laparoscopic incisional hernia repair alone is unknown and needs evaluation. Due to increasing antimicrobial resistance, a major global health care problem, AP needs to be critically evaluated. The aim of this study was to investigate the impact of AP on the rate of SSI and complication-related reoperations in patients undergoing laparoscopic incisional hernia repair. MATERIALS AND METHODS: Prospectively documented data from the Herniamed Hernia Registry from 2009 to 2017 were retrospectively analysed. Multivariable analyses were used to study the influence of AP as well as further patient and surgery-related risk factors on SSI and complication-related reoperation rates. This was verified in a sensitivity analysis using propensity-score matching. RESULTS: In the analysed time period 13'513 patients undergoing elective laparoscopic incisional hernia repair were recorded, of which 14.4% (n = 1949) did not receive AP. The overall SSI rate showed no significant difference when directly comparing patients with (0.74%) and without AP (0.97%; p = 0.262). In the multivariable analysis the presence of patient related risk factors (p = 0.015) and defect size >10 cm (p = 0.035) significantly increased the rates of SSI and complication-related reoperations. The propensity-score matching analysis verified that SSI rates are not significantly different between the two groups (p = 0.265). CONCLUSIONS: In cases of laparoscopic incisional hernia repair in patients without risk factors and moderate hernia diameter (<10 cm), routine administration of AP in laparoscopic incisional hernia repair does not seem to be justified.

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.

Does coagulopathy, anticoagulant or antithrombotic therapy matter in incisional hernia repair? Data from the Herniamed Registry.

BACKGROUND: A considerable number of patients undergoing incisional hernia repair are on anticoagulant or antiplatelet therapy or have existing coagulopathy which may put them at higher risk for postoperative bleeding complications. Data about the optimal treatment of these patients are sparse. This analysis attempts to determine the rate of postoperative bleeding complications following incisional hernia repair and the consecutive rate of reoperation among patients with coagulopathy or receiving antiplatelet and anticoagulant therapy (higher risk group) compared to patients who do not have a higher risk (normal risk group). METHODS: Out of the 43,101 patients documented in the Herniamed Registry who had an incisional hernia repair, 6668 (15.5%) were on anticoagulant or antithrombotic therapy or had existing coagulopathy. The implication of that higher risk profile for onset of postoperative bleeding was investigated in multivariable analysis. Hence, other influential variables were identified. RESULTS: The rate of postoperative bleeding in the higher risk group was 3.9% (n = 261) and significantly higher compared to the normal risk group at 1.6% (n = 564) (OR 2.001 [1.699; 2.356]; p < 0.001). Additionally, male gender, use of drains, larger defect size, open incisional hernia repair, lower BMI, and higher ASA score significantly increased the risk of postoperative bleeding. The rate of reoperations due to postoperative bleeding was significantly increased in the higher risk group compared to the normal risk group (2.4 vs. 1.0%; OR 1.217 [1.071; 1.382]; p = 0.003). Likewise, the postoperative general complication rate (6.04 vs. 3.66%; p < 0.001) as well as the mortality rate (0.46 vs. 0.17%; p < 0.001) were significantly higher in the higher risk group. CONCLUSIONS: Patients with anticoagulant or antiplatelet therapy or existing coagulopathy who undergo incisional hernia repair have a significantly higher risk for onset of postoperative bleeding. The risk of bleeding complications and complication-related reoperations seems to be lower after laparoscopic intraperitoneal onlay mesh.

Colon Perfusion Patterns During Colorectal Resection Using Visible Light Spectroscopy.

BACKGROUND: The impact of blood supply to the anastomosis on development of anastomotic leakage is still a matter of debate. Considering that bowel perfusion may be affected by manipulation during surgery, perfusion assessment of the anastomosis alone may be of limited value. We propose perfusion assessment at different time points during surgery to explore the dynamics of bowel perfusion during colorectal resection and its impact on outcome. METHODS: In this prospective cohort study, patients undergoing elective colorectal resection were eligible. Colon perfusion was evaluated using visible light spectroscopy. Main outcome was the difference in colon perfusion, quantified by measuring tissue oxygen saturation (StO2) in the colonic serosa, before and after anastomosis during surgery. RESULTS: We included 58 patients between July 2013 and November 2015. Colon perfusion increased by an average of 5.9% StO2 during surgery (95% confidence interval 3.1, 8.8; P < 0.001). The number of patients with abnormal perfusion (defined as StO2 < 65%) decreased from 50% at the beginning to 24% by the end of surgery. Six patients (10%) developed anastomotic leaks (AL), of which five patients had abnormal perfusion at the beginning of surgery, whereas four patients had normal StO2 at the anastomosis. CONCLUSION: Colon perfusion significantly increased during colorectal surgery. Considering that one quarter of patients had suboptimal anastomotic perfusion without developing AL, impaired blood flow at the anastomosis alone does not seem to be critical. Further investigations including more patients are necessary to evaluate the impact of perioperative parameters on colon perfusion, anastomotic healing and surgical outcome.

Timing of surgical antimicrobial prophylaxis: a phase 3 randomised controlled trial.

BACKGROUND: Based on observational studies, administration of surgical antimicrobial prophylaxis (SAP) for the prevention of surgical site infection (SSI) is recommended within 60 min before incision. However, the precise optimum timing is unknown. This trial compared early versus late administration of SAP before surgery. METHODS: In this phase 3 randomised controlled superiority trial, we included general surgery adult inpatients (age ≥18 years) at two Swiss hospitals in Basel and Aarau. Patients were randomised centrally and stratified by hospital according to a pre-existing computer-generated list in a 1:1 ratio to receive SAP early in the anaesthesia room or late in the operating room. Patients and the outcome assessment team were blinded to group assignment. SAP consisted of single-shot, intravenous infusion of 1·5 g of cefuroxime, a commonly used cephalosporin with a short half-life, over 2-5 min (combined with 500 mg metronidazole in colorectal surgery). The primary endpoint was the occurrence of SSI within 30 days of surgery. The main analyses were by intention to treat. The trial is registered with ClinicalTrials.gov, number NCT01790529. FINDINGS: Between Feb 21, 2013, and Aug 3, 2015, 5580 patients were randomly assigned to receive SAP early (2798 patients) or late (2782 patients). 5175 patients (2589 in the early group and 2586 in the late group) were analysed. Median administration time was 42 min before incision in the early group (IQR 30-55) and 16 min before incision in the late group (IQR 10-25). Inpatient follow-up rate was 100% (5175 of 5175 patients); outpatient 30-day follow-up rate was 88·8% (4596 of 5175), with an overall SSI rate of 5·1% (234 of 4596). Early administration of SAP did not significantly reduce the risk of SSI compared with late administration (odds ratio 0·93, 95% CI 0·72-1·21, p=0·601). INTERPRETATION: Our findings do not support any narrowing of the 60-min window for the administration of a cephalosporin with a short half-life, thereby obviating the need for increasingly challenging SAP timing recommendations. FUNDING: Swiss National Science Foundation, Hospital of Aarau, University of Basel, Gottfried und Julia Bangerter-Rhyner Foundation, Hippocrate Foundation, and Nora van Meeuwen-Häfliger Foundation.

Intraoperative Patterns of Gastric Microperfusion During Laparoscopic Sleeve Gastrectomy.

BACKGROUND: Laparoscopic sleeve gastrectomy (LSG) has become a very popular surgical treatment for the treatment of morbidly obese patients. Staple line leaks are the major cause of severe morbidity. Reasons for leaks might be hyperpressure (mechanical theory) or hypoperfusion (vascular theory) of the narrow gastric tube. This study assessed microperfusion patterns of the stomach during LSG using visible light spectroscopy (VLS), a method to measure tissue oxygenation (saturated O2 (StO2)). METHODS: The study population comprised 20 patients undergoing LSG. Real-time intraoperative microperfusion measurements were performed at nine different ventral stomach localizations in the antrum, body, and fundus at the beginning of the operation, after mobilization of the greater curve and after sleeve resection. RESULTS: There were 17 women and 3 men, mean age 42.9 years, mean BMI 45.6 kg/m2. There were no staple line leaks. StO2% values dropped substantially in the most cephalad area of measurement at the greater curve after mobilization (56 versus 49 %) and after resection (60 versus 49.5 %). The reduction in StO2 in the most cephalad area from before mobilization of the stomach to resection was 9.5 % (p < 0.01). CONCLUSION: Assessment of microperfusion patterns of the stomach during LSG using VLS is safe and efficacious to use allowing an accurate measurement of StO2%. The upper third of the stomach is the zone of reduced microperfusion with a significant drop of tissue oxygenation after sleeve resection of the stomach.