Evaluation of an aPTT guided versus a multimodal heparin monitoring approach in patients on extra corporeal membrane oxygenation: A retrospective cohort study.

INTRODUCTION: Bleeding and thrombotic complications are common in extracorporeal membrane oxygenation (ECMO) patients and are associated with increased mortality and morbidity. The optimal anticoagulation monitoring protocol in these patients is unknown. This study aims to compare the incidence of thrombotic and hemorrhagic complications before and after a protocol change. In addition, the association between hemostatic complications, coagulation tests and risk factors is evaluated. METHODS: This is a retrospective single center cohort study of adult ECMO patients. We collected demographics, ECMO parameters and coagulation test results. Outcomes of the aPTT guided and multimodal protocol, including aPTT, anti-Xa assay and rotational thromboelastometry were compared and the association between coagulation tests, risk factors and hemostatic complications was determined using a logistic regression analysis for repeated measurements. RESULTS: In total, 250 patients were included, 138 in the aPTT protocol and 112 in the multimodal protocol. The incidence of thrombosis (aPTT: 14%; multimodal: 12%) and bleeding (aPTT: 36%; multimodal: 40%), did not significantly differ between protocols. In the aPTT guided protocol, the aPTT was associated with thrombosis (Odds Ratio [OR] 1.015; 95% confidence interval [CI] 1.004-1.027). In both protocols, surgical interventions were risk factors for bleeding and thrombotic complications (aPTT: OR 93.2, CI 39.9-217.6; multimodal OR 17.5, CI 6.5-46.9). DISCUSSION: The incidence of hemostatic complications was similar between both protocols and surgical interventions were a risk factor for hemostatic complications. Results from this study help to elucidate the role of coagulation tests and risk factors in predicting hemostatic complications in patients undergoing ECMO support.

Predicting blood loss in burn excisional surgery.

BACKGROUND: Blood loss during burn excisional surgery remains an important factor as it is associated with significant comorbidity, mortality and longer length of stay. Blood loss is, among others, influenced by length of surgery, burn size, excision size and age. Most literature available is aimed at large burns and little research is available for small burns. Therefore, the goal of this study is to investigate blood loss and develop a prediction model to identify patient at risk for blood loss during burn excisional surgery ≤ 10% body surface area. STUDY DESIGN AND METHODS: This retrospective study included adult patients who underwent burn excisional surgery of ≤ 10% body surface area in the period 2013-2018. Duplicates, patients with missing data and delayed surgeries were excluded. Primary outcome was blood loss. A prediction model for per-operative blood loss (>250 ml) was built using a multivariable logistic regression analysis with stepwise backward elimination. Discriminative ability was assessed by the area under the ROC-curve in conjunction with optimism and calibration. RESULTS: In total 269 patients were included for analysis. Median blood loss was 50 ml (0-150) / % body surface area (BSA) excised and 0.28 (0-0.81) ml / cm2. Median burn size was 4% BSA and median excision size was 2% BSA. Blood loss of> 250 ml was present in 39% of patients. The model can predict blood loss> 250 ml based on %BSA excised, length of surgery and ASA-score with an AUC of 0.922 (95% CI 0.883 - 0.949) and an AUC after optimism correction of 0.915. The calibration curve showed an intercept of 0.0 (95% CI -0.36 to 0.36) with a slope of 1.0 (95% CI 0.78-1.22). CONCLUSION: Median blood loss during burn excisional surgery of ≤ 10% BSA is 50 ml / % BSA excised and 0.28 ml / cm2 excised. However, a substantial part of patients is at risk for higher blood loss. The prediction model can predict P(blood loss>250 ml) with an AUC of 0.922, based on expected length of surgery, ASA-score and size of excision. The model can be used to identify patients at risk for significant blood loss (>250 ml).

Postoperative Hemodynamic Index Measurement With Miniaturized Dynamic Light Scattering Predicts Colorectal Anastomotic Healing.

INTRODUCTION: Perioperative bowel perfusion (local hemodynamic index [LHI]) was measured with a miniaturized dynamic light scattering (mDLS) device, aiming to determine whether anastomotic perfusion correlates with the anastomotic healing process and whether LHI measurement assists in the detection of anastomotic leakage (AL) in colorectal surgery. METHODS: A partial colectomy was performed in 21 male Wistar rats. Colonic and anastomotic LHIs were recorded during operation. On postoperative day (POD) 3, the rats were examined for AL manifestations. Anastomotic LHI was recorded before determining the anastomotic bursting pressure (ABP). The postoperative LHI measurements were repeated in 15 other rats with experimental colitis. Clinical manifestations and anastomotic LHI were also determined on POD3. Diagnostic value of LHI measurement was analyzed with the combined data from both experiments. RESULTS: Intraoperative LHI measurement showed no correlation with the ABP on POD3. Postoperative anastomotic LHI on POD3 was significantly correlated with ABP in the normal rats (R(2) = 0.52; P < .001) and in the rats with colitis (R(2) = 0.63; P = .0012). Anastomotic LHI on POD3 had high accuracy for identifying ABP <50 mm Hg (Area under the curve = 0.86; standard error = 0.065; P < .001). A cutoff point of 1236 yielded a sensitivity of 100% and a specificity of 65%. On POD3, rats with LHIs <1236 had significantly higher dehiscence rates (40% vs 0%), more weight loss, higher abscess severity, and lower ABPs (P < .05); worse anastomotic inflammation and collagen deposition were also found in the histological examination. CONCLUSION: Our data suggest that postoperative evaluation of anastomotic microcirculation with the mDLS device assists in the detection of AL in colorectal surgery.

Reducing colorectal anastomotic leakage with tissue adhesive in experimental inflammatory bowel disease.

BACKGROUND: Anastomotic leakage after gastrointestinal surgery remains a challenging clinical problem. This study aimed to investigate the effectiveness of TissuCol (fibrin glue), Histoacryl Flex (n-butyl-2-cyanoacrylate), and Duraseal (polyethylene glycol) on colorectal anastomotic healing during experimental colitis. METHODS: We first performed colectomy 7 days after 10 mg trinitrobenzene sulfonic acid (TNBS)-induced colitis to validate a rat TNBS-colitis-colectomy model. Subsequently, this TNBS-colitis-colectomy model was used in 73 Wistar rats that were stratified into a colitis group (CG, no adhesive), a TissuCol group (TG), a Histoacryl group (HG), and a Duraseal group (DG). Anastomotic sealant was applied with one adhesive after constructing an end-to-end hand-sewn anastomosis. Clinical manifestations, anastomotic bursting pressure, and immunohistochemistry of macrophage type-one (M1) and type-two (M2) was performed on postoperative day (POD)3 or POD7. RESULTS: TNBS-caused mucosal and submucosal colon damage and compromised anastomotic healing (i.e., abscess formation and low anastomotic bursting pressure). On POD3, higher severity of abscesses was seen in CG. Average anastomotic bursting pressure was 53.2 ± 35.5 mm Hg in CG, which was significantly lower than HG (134.4 ± 27.5 mm Hg) and DG (95.1 ± 54.3 mm Hg) but not TG (83.4 ± 46.7 mm Hg). Furthermore, a significantly higher M2/M1 index was found in HG. On POD7, abscesses were only seen in CG (6/9) but not in other groups; HG had the lowest severity of adhesion. CONCLUSIONS: We describe the first surgical IBD model by performing colectomy in rats with TNBS-induced colitis, which causes intra-abdominal abscess formation and compromises anastomotic healing. Anastomotic sealing with Histoacryl Flex prevents these complications in this model. Alternative activation of macrophages seems to be involved in its influence on anastomotic healing.