Quantitative analysis of intestinal perfusion with indocyanine green (ICG) and methylene blue (MB) using a single clinically approved fluorescence imaging system: a demonstration in a porcine model.

BACKGROUND: Near-infrared fluorescence (NIRF) angiography with intraoperative administration of indocyanine green (ICG) has rapidly disseminated in clinical practice. Another clinically approved, and widely available dye, methylene blue (MB), has up to now not been used for this purpose. Recently, we demonstrated promising results for the real-time evaluation of intestinal perfusion using this dye. The primary aim of this study was to perform a quantitative analysis of bowel perfusion assessment for both ICG and MB. METHODS: Four mature female Landrace pigs underwent laparotomy under general anesthesia. An ischemic bowel loop with five regions of interest (ROIs) with varying levels of perfusion was created in each animal. An intravenous (IV) injection of 0.25 mg/kg-0.50 mg/kg MB was administered after 10 min, followed by NIRF imaging in MB mode and measurement of local lactate levels in all corresponding ROIs. This procedure was repeated in ICG mode (IV dose of 0.2 mg/kg) after 60 min. The quest spectrum fluorescence camera (Quest Medical Imaging, Middenmeer, The Netherlands) was used for NIRF imaging of both MB and ICG. RESULTS: Intraoperative NIRF imaging of bowel perfusion assessment with MB and ICG was successful in all studied animals. Ingress (i/s) levels were calculated and correlated with local lactate levels. Both MB and ICG ingress values showed a significant negative correlation (r = - 0.7709; p = < 0.001; r = - 0.5367, p = 0.015, respectively) with local lactate levels. This correlation was stronger for MB compared to ICG, although ICG analysis showed higher absolute ingress values. CONCLUSION: Our fluorescence quantification analysis validates the potential to use MB for bowel perfusion assessment besides the well-known and widely used ICG. Further human studies are necessary to translate our findings to clinical applications.

Real-time quantification of laser speckle contrast imaging during intestinal laparoscopic surgery: successful demonstration in a porcine intestinal ischemia model.

BACKGROUND: Anastomotic leakage (AL) is a dreaded complication following colorectal cancer surgery, impacting patient outcome and leads to increasing healthcare consumption as well as economic burden. Bowel perfusion is a significant modifiable factor for anastomotic healing and thus crucial for reducing AL. AIMS: The study aimed to calculate a cut-off value for quantified laser speckle perfusion units (LSPUs) in order to differentiate between ischemic and well-perfused tissue and to assess inter-observer reliability. METHODS: LSCI was performed using a porcine ischemic small bowel loop model with the PerfusiX-Imaging® system. An ischemic area, a well-perfused area, and watershed areas, were selected based on the LSCI colormap. Subsequently, local capillary lactate (LCL) levels were measured. A logarithmic curve estimation tested the correlation between LSPU and LCL levels. A cut-off value for LSPU and lactate was calculated, based on anatomically ischemic and well-perfused tissue. Inter-observer variability analysis was performed with 10 observers. RESULTS: Directly after ligation of the mesenteric arteries, differences in LSPU values between ischemic and well-perfused tissue were significant (p < 0.001) and increased significantly throughout all following measurements. LCL levels were significantly different (p < 0.001) at both 60 and 120 min. Logarithmic curve estimation showed an R2 value of 0.56 between LSPU and LCL values. A LSPU cut-off value was determined at 69, with a sensitivity of 0.94 and specificity of 0.87. A LCL cut-off value of 3.8 mmol/L was found, with a sensitivity and specificity of 0.97 and 1.0, respectively. There was no difference in assessment between experienced and unexperienced observers. Cohen's Kappa values were moderate to good (0.52-0.66). CONCLUSION: Real-time quantification of LSPUs may be a feasible intraoperative method to assess tissue perfusion and a cut-off value could be determined with high sensitivity and specificity. Inter-observer variability was moderate to good, irrespective of prior experience with the technique.

Sustainability in surgical practice: a collaborative call toward environmental sustainability in operating rooms.

BACKGROUND: The healthcare system plays a pivotal role in environmental sustainability, and the operating room (OR) significantly contributes to its overall carbon footprint. In response to this critical challenge, leading medical societies, government bodies, regulatory agencies, and industry stakeholders are taking measures to address healthcare sustainability and its impact on climate change. Healthcare now represents almost 20% of the US national economy and 8.5% of US carbon emissions. Internationally, healthcare represents 5% of global carbon emissions. US Healthcare is an outlier in both per capita cost, and per capita greenhouse gas emission, with almost twice per capita emissions compared to every other country in the world. METHODS: The Society of American Gastrointestinal and Endoscopic Surgeons (SAGES) and the European Association for Endoscopic Surgery (EAES) established the Sustainability in Surgical Practice joint task force in 2023. This collaborative effort aims to actively promote education, mitigation, and innovation, steering surgical practices toward a more sustainable future. RESULTS: Several key initiatives have included a survey of members' knowledge and awareness, a scoping review of terminology, metrics, and initiatives, and deep engagement of key stakeholders. DISCUSSION: This position paper serves as a Call to Action, proposing a series of actions to catalyze and accelerate the surgical sustainability leadership needed to respond effectively to climate change, and to lead the societal transformation towards health that our times demand.

EAES/SAGES evidence-based recommendations and expert consensus on optimization of perioperative care in older adults.

BACKGROUND: As the population ages, more older adults are presenting for surgery. Age-related declines in physiological reserve and functional capacity can result in frailty and poor outcomes after surgery. Hence, optimizing perioperative care in older patients is imperative. Enhanced Recovery After Surgery (ERAS) pathways and Minimally Invasive Surgery (MIS) may influence surgical outcomes, but current use and impact on older adults patients is unknown. The aim of this study was to provide evidence-based recommendations on perioperative care of older adults undergoing major abdominal surgery. METHODS: Expert consensus determined working definitions for key terms and metrics related to perioperative care. A systematic literature review and meta-analysis was performed using the PubMed, Embase, Cochrane Library, and Clinicaltrials.gov databases for 24 pre-defined key questions in the topic areas of prehabilitation, MIS, and ERAS in major abdominal surgery (colorectal, upper gastrointestinal (UGI), Hernia, and hepatopancreatic biliary (HPB)) to generate evidence-based recommendations following the GRADE methodology. RESULT: Older adults were defined as 65 years and older. Over 20,000 articles were initially retrieved from search parameters. Evidence synthesis was performed across the three topic areas from 172 studies, with meta-analyses conducted for MIS and ERAS topics. The use of MIS and ERAS was recommended for older adult patients particularly when undergoing colorectal surgery. Expert opinion recommended prehabilitation, cessation of smoking and alcohol, and correction of anemia in all colorectal, UGI, Hernia, and HPB procedures in older adults. All recommendations were conditional, with low to very low certainty of evidence, with the exception of ERAS program in colorectal surgery. CONCLUSIONS: MIS and ERAS are recommended in older adults undergoing major abdominal surgery, with evidence supporting use in colorectal surgery. Though expert opinion supported prehabilitation, there is insufficient evidence supporting use. This work has identified evidence gaps for further studies to optimize older adults undergoing major abdominal surgery.

International survey among surgeons on the perioperative management of rectal cancer.

BACKGROUND: Several pivotal studies and international guidelines on the perioperative management of rectal cancer have been published. However, little is known about the current state of perioperative management of rectal cancer patients in clinical practice worldwide. METHODS: An online survey including 13 questions focusing on key topics related to the perioperative management of patients with rectal cancer was conducted among colorectal surgeons registered within the database of the Research Institute Against Digestive Cancer (IRCAD). RESULTS: A total of 535 respondents from 89 countries participated in the survey. Most surgeons worked in the European region (40.9%). Two hundred and fifty-four respondents (47.5%) performed less than 25% of surgical procedures laparoscopically. The most commonly used definition of the upper limit of the rectum was a fixed distance from the anal verge (23.4%). Magnetic resonance imaging was used to define the upper limit of the rectum by 258 respondents (48.2%). During total mesorectal excision (TME), 301 respondents (56.3%) used a high-tie technique. The most commonly constructed anastomosis was an end-to-end anastomosis (68.2%) with the majority of surgeons performing a leak test intraoperatively (88.9%). A total of 355 respondents (66.4%) constructed a diverting ostomy, and the majority of these surgeons constructed an enterostomy (82%). A total of 208 respondents (39.3%) closed a stoma within 8 weeks. Lastly, 135 respondents (25.2%) introduced a solid diet on postoperative day 1. CONCLUSION: There is considerable heterogeneity in the perioperative management of rectal cancer patients worldwide with several discrepancies between current international practice and recommendations from international guidelines. To achieve worldwide standardization in rectal cancer care, further research is needed to elucidate the cause of this heterogeneity and find ways of improved implementation of best practice recommendations.

Experimental evaluation of laparoscopic laser speckle contrast imaging to visualize perfusion deficits during intestinal surgery.

BACKGROUND: Ischemia at the site of an intestinal anastomosis is one of the most important risk factors for anastomotic leakage (AL). Consequently, adequate intestinal microperfusion is essential for optimal tissue oxygenation and anastomotic healing. As visual inspection of tissue viability does not guarantee an adequate objective evaluation of intestinal microperfusion, surgeons are in dire need of supportive tools to decrease anastomotic leakage after colorectal surgery. METHODS: In this feasibility study, laparoscopic laser speckle contrast imaging (LSCI) was used to evaluate intestinal microperfusion in an experimental ischemic bowel loop model. Both large and small ischemic loops were created from the small intestine of a pig; each loop was divided into 5 regions of interest (ROI) with varying levels of ischemia. Speckle contrast and local capillary lactate (LCL) was measured in all ROIs. RESULTS: Both real-time visualization of intestinal microperfusion and induced perfusion deficits was achieved in all bowel loops. As a result, the emergence of regions of intestinal ischemia could be predicted directly after iatrogenic perfusion limitation, whereas without LSCI signs of decreased intestinal viability could only be seen after 30 minutes. Additionally, a significant relation was found between LCL and LSCI. CONCLUSION: In conclusion, LSCI can achieve real-time intraoperative visualization of intestinal microperfusion deficits, allowing for accurate prediction of long-term postoperative ischemic complications. With this revealing capacity, LSCI could potentially facilitate surgical decision-making when constructing intestinal anastomoses in order to mitigate ischemia-related complications such as AL.

Simultaneous fluorescence imaging of bowel perfusion and ureter delineation using methylene blue: a demonstration in a porcine model.

BACKGROUND: Intraoperative near-infrared fluorescence imaging (NIRF) with preoperative optical dye administration is a promising technique for quick and easy intraoperative visualization of the ureter and for an improved, real-time assessment of intestinal perfusion. During colorectal surgery, there is a need for simultaneous non-invasive ureteral imaging and bowel perfusion assessment, using one single camera system. The purpose of this study is to investigate the feasibility of simultaneous intestinal perfusion and ureteral imaging using a single commercially available NIRF imaging system. METHODS: Six Landrace pigs underwent laparotomy under general anesthesia in this experiment. An intravenous (IV) dose of 0.2 mg/kg indocyanine green (ICG) was given to assess bowel perfusion. Two pairs received a methylene blue (MB) iv injection of 0.75, 0.50 or 0.25 mg/kg respectively to investigate ureteral visualization. Quest Spectrum Fluorescence Camera (Quest Medical Imaging, Middenmeer, The Netherlands) was used for NIRF imaging. RESULTS: Ureter visualization and bowel perfusion under NIRF imaging was achieved in all animals. All ureters were visible after five to ten minutes and remained clearly visible until the end of every experiment (120-420 min). A mixed model analysis did not show any significant differences neither between the three groups nor over time. Importantly, we demonstrated that bowel perfusion could be visualized with methylene blue (MB) as well. We observed no interference between ICG and MB and a faster washout of MB. CONCLUSION: We successfully demonstrated simultaneous fluorescence angiography with ICG and ureteral imaging with MB in the same surgical procedure, with the same commercially available NIRF imaging equipment. More importantly, we showed that the use MB is adequate for bowel perfusion assessment and ureter visualization with this NIRF imaging system. Besides, MB showed an earlier washout time, which can be clinical beneficial as a repeated dye injection may be necessary during a surgical procedure.

Sensory brain activation during rectal balloon distention: a pilot study in healthy volunteers to assess safety and feasibility at 1.5T.

OBJECTIVE: Although increasing evidence suggests a central mechanism of action for sacral neuromodulation, the exact mechanism remains unclear. We set up a scanning paradigm to measure brain activation related to various stages of rectal filling using rectal balloon distention. MATERIALS AND METHODS: Six healthy volunteers underwent rectal balloon distention during MRI scanning at a 1.5T scanner with a Tx/Rx head coil. MR images were collected at four levels of distention: empty balloon (EB), first sensation volume (FSV), desire to defecate volume (DDV), maximum tolerable volume (MTV). Data were analyzed using BrainVoyager 20.4. Whole brain and ROI-based fixed-effects general linear model analyses were performed on the fMRI time-course data from all participants. RESULTS: Rectal filling until FSV evoked the most blood-oxygen-level-dependent responses in several clusters throughout the cortex, followed by the responses evoked by rectal filling until DDV. Interestingly, rectal filling until MTV evoked negative responses compared to baseline throughout the cortex. No negative side effects were found. DISCUSSION: This study shows that a standardized paradigm for functional MRI combined with rectal filling is feasible and safe in healthy volunteers and is ready to be used in fecal incontinent patients to assess whether their brain activity differs from healthy controls.

Predictive Genetic Biomarkers for the Development of Peritoneal Metastases in Colorectal Cancer.

Metastatic colorectal cancer (CRC) is a common cause of cancer-related mortality, of which peritoneal metastases (PMs) have the worse outcome. Metastasis-specific markers may help predict the spread of tumor cells and select patients for preventive strategies. This exploratory pilot study aimed to gain more insight into genetic alterations in primary CRC tumors, which might be a predictive factor for the development of PM. Forty patients with T3 stage CRC were retrospectively divided in three groups: without metachronous metastases during 5-year follow-up (M0, n = 20), with metachronous liver metastases (LM, n = 10) and with metachronous PM (PM, n = 10). Patients with synchronous metastases were excluded. Primary formalin-fixed paraffin-embedded tumor samples were analyzed via comprehensive genome sequencing (TSO500 analysis) to identify DNA alterations and RNA fusion transcripts in 523 genes and 55 genes, respectively. Thirty-eight samples were included for final analysis. Four M0 tumors and one PM tumor were microsatellite instable. BRAF mutations were uniquely identified in three microsatellite-stable (MSS) PM tumors (37.5%, p = 0.010). RNA analysis showed an additional FAM198A-RAF1 fusion in one PM sample. BRAF p.V600E mutations were only present in PM patients with MSS tumors. Greater attention should be paid to BRAF-mutated tumors in relation to the development of metachronous PM.

Favorable Outcomes After Retro-Rectus (Rives-Stoppa) Mesh Repair as Treatment for Noncomplex Ventral Abdominal Wall Hernia, a Systematic Review and Meta-analysis.

OBJECTIVE: To assess prevalence of hernia recurrence, surgical site infection (SSI), seroma, serious complications, and mortality after retro-rectus repair. SUMMARY BACKGROUND DATA: Ventral abdominal wall hernia is a common problem, tied to increasing frailty and obesity of patients undergoing surgery. For noncomplex ventral hernia, retro-rectus (Rives-Stoppa) repair is considered the gold standard treatment. Level-1 evidence confirming this presumed superiority is lacking. METHODS: Five databases were searched for studies reporting on retro-rectus repair. Single-armed and comparative randomized and non-randomized studies were included. Outcomes were pooled with mixed-effects, inverse variance or random-effects models. RESULTS: Ninety-three studies representing 12,440 patients undergoing retro-rectus repair were included. Pooled hernia recurrence was estimated at 3.2% [95% confidence interval (CI): 2.2%-4.2%, n = 11,049] after minimally 12months and 4.1%, (95%CI: 2.9%-5.5%, n = 3830) after minimally 24 months. Incidences of SSI and seroma were estimated at respectively 5.2% (95%CI: 4.2%-6.4%, n = 4891) and 5.5% (95%CI: 4.4%-6.8%, n = 3650). Retro-rectus repair was associated with lower recurrence rates compared to onlay repair [odds ratios (OR): 0.27, 95%CI: 0.15-0.51, P < 0.001] and equal recurrence rates compared to intraperitoneal onlay mesh (IPOM) repair (OR: 0.92, 95%CI: 0.75-1.12, P = 0.400). Retro-rectus repair was associated with more SSI than IPOM repair (OR: 1.8, 95%CI: 1.03 -3.14, P = 0.038). Minimally invasive retro-rectus repair displayed low rates of recurrence (1.3%, 95%CI: 0.7%-2.3%, n = 849) and SSI (1.5%, 95%CI: 0.8%-2.8%, n = 982), albeit based on non-randomized studies. CONCLUSIONS: Retro-rectus (Rives-Stoppa) repair results in excellent outcomes, superior or similar to other techniques for all outcomes except SSI. The latter rarely occurred, yet less frequently after IPOM repair, which is usually performed by laparoscopy.

UEG and EAES rapid guideline: Systematic review, meta-analysis, GRADE assessment and evidence-informed European recommendations on TaTME for rectal cancer.

BACKGROUND: Evidence and practice recommendations on the use of transanal total mesorectal excision (TaTME) for rectal cancer are conflicting. OBJECTIVE: We aimed to summarize best evidence and develop a rapid guideline using transparent, trustworthy, and standardized methodology. METHODS: We developed a rapid guideline in accordance with GRADE, G-I-N, and AGREE II standards. The steering group consisted of general surgeons, members of the EAES Research Committee/Guidelines Subcommittee with expertise and experience in guideline development, advanced medical statistics and evidence synthesis, biostatisticians, and a guideline methodologist. The guideline panel consisted of four general surgeons practicing colorectal surgery, a radiologist with expertise in rectal cancer, a radiation oncologist, a pathologist, and a patient representative. We conducted a systematic review and the results of evidence synthesis by means of meta-analyses were summarized in evidence tables. Recommendations were authored and published through an online authoring and publication platform (MAGICapp), with the guideline panel making use of an evidence-to-decision framework and a Delphi process to arrive at consensus. RESULTS: This rapid guideline provides a weak recommendation for the use of TaTME over laparoscopic or robotic TME for low rectal cancer when expertise is available. Furthermore, it details evidence gaps to be addressed by future research and discusses policy considerations. The guideline, with recommendations, evidence summaries, and decision aids in user-friendly formats can also be accessed in MAGICapp: https://app.magicapp.org/#/guideline/4494 . CONCLUSIONS: This rapid guideline provides evidence-informed trustworthy recommendations on the use of TaTME for rectal cancer.

EAES rapid guideline: systematic review, network meta-analysis, CINeMA and GRADE assessment, and European consensus on bariatric surgery-extension 2022.

BACKGROUND: The European Association for Endoscopic Surgery Bariatric Guidelines Group identified a gap in bariatric surgery recommendations with a structured, contextualized consideration of multiple bariatric interventions. OBJECTIVE: To provide evidence-informed, transparent and trustworthy recommendations on the use of sleeve gastrectomy, Roux-en-Y gastric bypass, adjustable gastric banding, gastric plication, biliopancreatic diversion with duodenal switch, one anastomosis gastric bypass, and single anastomosis duodeno-ileal bypass with sleeve gastrectomy in patients with severe obesity and metabolic diseases. Only laparoscopic procedures in adults were considered. METHODS: A European interdisciplinary panel including general surgeons, obesity physicians, anesthetists, a psychologist and a patient representative informed outcome importance and minimal important differences. We conducted a systematic review and frequentist fixed and random-effects network meta-analysis of randomized-controlled trials (RCTs) using the graph theory approach for each outcome. We calculated the odds ratio or the (standardized) mean differences with 95% confidence intervals for binary and continuous outcomes, respectively. We assessed the certainty of evidence using the CINeMA and GRADE methodologies. We considered the risk/benefit outcomes within a GRADE evidence to decision framework to arrive at recommendations, which were validated through an anonymous Delphi process of the panel. RESULTS: We identified 43 records reporting on 24 RCTs. Most network information surrounded sleeve gastrectomy and Roux-en-Y gastric bypass. Under consideration of the certainty of the evidence and evidence to decision parameters, we suggest sleeve gastrectomy or laparoscopic Roux-en-Y gastric bypass over adjustable gastric banding, biliopancreatic diversion with duodenal switch and gastric plication for the management of severe obesity and associated metabolic diseases. One anastomosis gastric bypass and single anastomosis duodeno-ileal bypass with sleeve gastrectomy are suggested as alternatives, although evidence on benefits and harms, and specific selection criteria is limited compared to sleeve gastrectomy and Roux-en-Y gastric bypass. The guideline, with recommendations, evidence summaries and decision aids in user friendly formats can also be accessed in MAGICapp:  https://app.magicapp.org/#/guideline/Lpv2kE CONCLUSIONS: This rapid guideline provides evidence-informed, pertinent recommendations on the use of bariatric and metabolic surgery for the management of severe obesity and metabolic diseases. The guideline replaces relevant recommendations published in the EAES Bariatric Guidelines 2020.

Near infrared fluorescence imaging of the urethra: a systematic review of the literature.

BACKGROUND: Urethral injury is a dreaded complication during laparoscopic, perineal and transanal surgery and is mainly a result of a failed visualization of the urethra. The aim of this systematic review is to provide an overview of the available literature on the near-infrared fluorescence (NIRF) imaging technique using contrast agents for the intra-operative visualization of the urethra. MATERIAL AND METHODS: A systematic review of the literature was conducted including studies on NIRF imaging using contrast agents to visualize the urethra. All studies describing a NIRF imaging technique and demonstrating visual findings of the urethra were included. RESULTS: Five studies were identified. Four studies examined indocyanine green, one of which also studied the IRDye® 800BK agent and one examined the CP-IRT dye. All studies showed that the NIRF imaging technique was feasible for an early identification of the urethra. No complications related to NIRF imaging were reported. CONCLUSION: We conclude that the use of a NIRF imaging technique is feasible and that it can contribute to prevent iatrogenic injury to the urethra. However, based on the limited available data, no solid conclusion can yet be drawn and further translation to the clinical practice is necessary.

Adhesion-related readmissions after open and laparoscopic surgery: a retrospective cohort study (SCAR update).

BACKGROUND: Adhesions are the most common driver of long-term morbidity after abdominal surgery. Although laparoscopy can reduce adhesion formation, the effect of minimally invasive surgery on long-term adhesion-related morbidity remains unknown. We aimed to assess the impact of laparoscopy on adhesion-related readmissions in a population-based cohort. METHODS: We did a retrospective cohort study of patients of any age who had abdominal or pelvic surgery done using laparoscopic or open approaches between June 1, 2009, and June 30, 2011, using validated population data from the Scottish National Health Service. All patients who had surgery were followed up until Dec 31, 2017. The primary outcome measure was the incidence of hospital readmissions directly related to adhesions in the laparoscopic and open surgery cohorts at 5 years. Readmissions were categorised as directly related to adhesions, possibly related to adhesions, and readmissions for an operation that was potentially complicated by adhesions. We did subgroup analyses of readmissions by anatomical site of surgery and used Kaplan-Meier analyses to assess differences in survival across subgroups. We used multivariable Cox-regression analysis to determine whether surgical approach was an independent and significant risk factor for adhesion-related readmissions. FINDINGS: Between June 1, 2009, and June 30, 2011, 72 270 patients had an index abdominal or pelvic surgery, of whom 21 519 (29·8%) had laparoscopic index surgery and 50 751 (70·2%) had open surgery. Of the 72 270 patients who had surgery, 2527 patients (3·5%) were readmitted within 5 years of surgery for disorders directly related to adhesions, 12 687 (17·6%) for disorders possibly related to adhesions, and 9436 (13·1%) for operations potentially complicated by adhesions. Of the 21 519 patients who had laparoscopic surgery, 359 (1·7% [95% CI 1·5-1·9]) were readmitted for disorders directly related to adhesions compared with 2168 (4·3% [4·1-4·5]) of 50 751 patients in the open surgery cohort (p<0·0001). 3443 (16·0% [15·6-16·4]) of 21 519 patients in the laparoscopic surgery cohort were readmitted for disorders possibly related to adhesions compared with 9244 (18·2% [17·8-18·6]) of 50 751 patients in the open surgery cohort (p<0·005). In multivariate analyses, laparoscopy reduced the risk of directly related readmissions by 32% (hazard ratio [HR] 0·68, 95% CI 0·60-0·77), and of possibly related readmissions by 11% (HR 0·89, 0·85-0·94) compared with open surgery. Procedure type, malignancy, sex, and age were also independently associated with risk of adhesion-related readmissions. INTERPRETATION: Laparoscopic surgery reduces the incidence of adhesion-related readmissions. However, the overall burden of readmissions associated with adhesions remains high. With further increases in the use of laparoscopic surgery expected in the future, the effect at the population level might become larger. Further steps remain necessary to reduce the incidence of adhesion-related postsurgical complications. FUNDING: Dutch Adhesion Group and Nordic Pharma.

Simultaneous multipurpose fluorescence imaging with IRDye® 800BK during laparoscopic surgery.

BACKGROUND: IRDye® 800BK is a fluorophore, currently undergoing clinical translation, which has both biliary and renal clearance. To date, there is no description of a fluorophore, which can be simultaneously used for non-invasive, near-infrared fluorescence-based (NIRF) visualization of different structures and perfusion evaluation. The purpose of this study was to evaluate IRDye® 800BK for the simultaneous assessment of bowel perfusion, lymphography, ureter and bile duct delineation. METHODS: Six pigs received a 0.15 mg/kg dye as a single bolus intravenous injection (IV). With the FLER (fluorescence-based enhanced reality) software, fluorescence intensity (FI) of 5 regions of interest (ROI) in an ischemic bowel loop was measured along with the time to reach the FI peak, and capillary lactate was measured from the same ROI, followed by the assessment of the ureters and bile ducts for a maximal duration of 180 min after dye administration. In 3 animals, the procedure was initiated via gastroscopic injection of a 0.6 mg (1 mg/mL) dye in the gastric submucosa followed by lymphography in a NIRF setting. RESULTS: Excellent visualization of the ureters and bowel perfusion was obtained under NIRF imaging. Additionally, the bile duct and gastric lymph ducts and nodes were visualized. A positive correlation was found between the time to peak FI in the ischemic bowel loop and the corresponding capillary lactate levels (rho 0.59, p < 0.001). CONCLUSION: In this study, we successfully demonstrated the simultaneous multipurpose IRDye® 800BK applicability during laparoscopic surgery. This fluorophore has the potential to become a powerful and versatile image-guided surgery tool.

Applying the electronic nose for pre-operative SARS-CoV-2 screening.

BACKGROUND: Infection with SARS-CoV-2 causes corona virus disease (COVID-19). The most standard diagnostic method is reverse transcription-polymerase chain reaction (RT-PCR) on a nasopharyngeal and/or an oropharyngeal swab. The high occurrence of false-negative results due to the non-presence of SARS-CoV-2 in the oropharyngeal environment renders this sampling method not ideal. Therefore, a new sampling device is desirable. This proof-of-principle study investigated the possibility to train machine-learning classifiers with an electronic nose (Aeonose) to differentiate between COVID-19-positive and negative persons based on volatile organic compounds (VOCs) analysis. METHODS: Between April and June 2020, participants were invited for breath analysis when a swab for RT-PCR was collected. If the RT-PCR resulted negative, the presence of SARS-CoV-2-specific antibodies was checked to confirm the negative result. All participants breathed through the Aeonose for five minutes. This device contains metal-oxide sensors that change in conductivity upon reaction with VOCs in exhaled breath. These conductivity changes are input data for machine learning and used for pattern recognition. The result is a value between - 1 and + 1, indicating the infection probability. RESULTS: 219 participants were included, 57 of which COVID-19 positive. A sensitivity of 0.86 and a negative predictive value (NPV) of 0.92 were found. Adding clinical variables to machine-learning classifier via multivariate logistic regression analysis, the NPV improved to 0.96. CONCLUSIONS: The Aeonose can distinguish COVID-19 positive from negative participants based on VOC patterns in exhaled breath with a high NPV. The Aeonose might be a promising, non-invasive, and low-cost triage tool for excluding SARS-CoV-2 infection in patients elected for surgery.

Clinical adhesion score (CLAS): development of a novel clinical score for adhesion-related complications in abdominal and pelvic surgery.

BACKGROUND: Adhesions are a major cause of long-term postsurgical complications in abdominal and pelvic surgery. Existing adhesion scores primarily measure morphological characteristics of adhesions that do not necessarily correlate with morbidity. The aim of this study was to develop a clinical adhesion score (CLAS) measuring overall clinical morbidity of adhesion-related complications in abdominal and pelvic surgery. METHODS: An international Delphi study was performed to identify relevant score items for adhesion-related complications, including small bowel obstruction, female infertility, chronic abdominal or pelvic pain, and difficulties at reoperation. The CLAS includes clinical outcomes, related to morbidity of adhesions, and weight factors, to correct the outcome scores for the likelihood that symptoms are truly caused by adhesions. In a pilot study, two independent researchers retrospectively scored the CLAS in 51 patients to evaluate inter-observer reliability, by calculating the Intraclass correlation coefficient. During a feasibility assessment, we evaluated whether the CLAS completely covered different clinical scenarios of adhesion-related morbidity. RESULTS: Three Delphi rounds were performed. 43 experts agreed to participate, 38(88%) completed the first round, and 32 (74%) the third round. Consensus was reached on 83.4% of items. Inter-observer reliability for the CLAS was 0.95 (95% CI 0.91-0.97). During feasibility assessment, six items were included. As a result, the CLAS includes 22 outcomes and 23 weight factors. CONCLUSION: The CLAS represents a promising scoring system to measure and monitor the clinical morbidity of adhesion-related complications. Further studies are needed to confirm its utility in clinical practice.

EAES Recommendations for Recovery Plan in Minimally Invasive Surgery Amid COVID-19 Pandemic.

BACKGROUND: COVID-19 pandemic presented an unexpected challenge for the surgical community in general and Minimally Invasive Surgery (MIS) specialists in particular. This document aims to summarize recent evidence and experts' opinion and formulate recommendations to guide the surgical community on how to best organize the recovery plan for surgical activity across different sub-specialities after the COVID-19 pandemic. METHODS: Recommendations were developed through a Delphi process for establishment of expert consensus. Domain topics were formulated and subsequently subdivided into questions pertinent to different surgical specialities following the COVID-19 crisis. Sixty-five experts from 24 countries, representing the entire EAES board, were invited. Fifty clinicians and six engineers accepted the invitation and drafted statements based on specific key questions. Anonymous voting on the statements was performed until consensus was achieved, defined by at least 70% agreement. RESULTS: A total of 92 consensus statements were formulated with regard to safe resumption of surgery across eight domains, addressing general surgery, upper GI, lower GI, bariatrics, endocrine, HPB, abdominal wall and technology/research. The statements addressed elective and emergency services across all subspecialties with specific attention to the role of MIS during the recovery plan. Eighty-four of the statements were approved during the first round of Delphi voting (91.3%) and another 8 during the following round after substantial modification, resulting in a 100% consensus. CONCLUSION: The recommendations formulated by the EAES board establish a framework for resumption of surgery following COVID-19 pandemic with particular focus on the role of MIS across surgical specialities. The statements have the potential for wide application in the clinical setting, education activities and research work across different healthcare systems.

Left Ventricular Geometrical Changes in Severely Obese Adolescents: Prevalence, Determinants, and Clinical Implications.

Left ventricular hypertrophy (LVH) is independently associated with a higher risk of cardiovascular morbidity and mortality in adults. Adiposity is a risk factor for LVH, independent of blood pressure. Potential causes of this nonhemodynamic pathogenesis identified in adults include adverse body fat distribution, insulin resistance, dyslipidemia, and obstructive sleep apnea syndrome (OSA). In severely obese adolescents, the determinants of obesity-induced changes in left ventricular structure are poorly characterized. Cardiac ultrasonographic, demographic, anthropometric, and comorbidity-related data were prospectively collected in adolescents with severe obesity refractory to conservative treatment who presented for surgical therapy. Differences between adolescents with LVH and without LVH were evaluated using independent samples t, chi-square, or Fisher's exact test. Multivariable linear regression analysis was performed to evaluate associations with left ventricular structural changes, corrected for body mass index (BMI) z score. Forty-three patients entered analysis, of whom 24 (55.8%) showed LVH. The most common geometrical change was eccentric LVH (eLVH), occurring in 21 subjects (48.8%). Demographic and anthropometric variables did not differ between patients with and without LVH. Independent of BMI z score, left ventricular mass index was significantly associated with apnea-hypopnea index (AHI) (regression parameter B = 0.8; 95% CI 0.3 to 1.2). Interventricular septum thickness (IVST) was significantly associated with HOMA-IR values (B = 0.1; 95% CI 0.04 to 0.2), HDL-cholesterol (B = - 1.2; 95% CI - 2.2 to 0.1), and triglyceride levels (B = 0.5; 95% CI 0.001 to 0.9). LVH, especially eLVH, is highly prevalent amongst severely obese adolescents. Adverse changes in cardiac structure, increased IVST in particular, are independently associated with several nonhemodynamic comorbidities that are common in this population, namely OSA, insulin resistance, and dyslipidemia.

Clinical practice guidelines of the European Association for Endoscopic Surgery (EAES) on bariatric surgery: update 2020 endorsed by IFSO-EC, EASO and ESPCOP.

BACKGROUND: Surgery for obesity and metabolic diseases has been evolved in the light of new scientific evidence, long-term outcomes and accumulated experience. EAES has sponsored an update of previous guidelines on bariatric surgery. METHODS: A multidisciplinary group of bariatric surgeons, obesity physicians, nutritional experts, psychologists, anesthetists and a patient representative comprised the guideline development panel. Development and reporting conformed to GRADE guidelines and AGREE II standards. RESULTS: Systematic review of databases, record selection, data extraction and synthesis, evidence appraisal and evidence-to-decision frameworks were developed for 42 key questions in the domains Indication; Preoperative work-up; Perioperative management; Non-bypass, bypass and one-anastomosis procedures; Revisional surgery; Postoperative care; and Investigational procedures. A total of 36 recommendations and position statements were formed through a modified Delphi procedure. CONCLUSION: This document summarizes the latest evidence on bariatric surgery through state-of-the art guideline development, aiming to facilitate evidence-based clinical decisions.