Intraoperative coagulation evaluation of ischemia-reperfusion injury in small bowel transplantation: a way to explore.

BACKGROUND AND AIM OF STUDY: The success of intestinal transplantation is affected by the extreme susceptibility of the small bowel to ischemia-reperfusion (I/R) injury. Platelet aggregation decreases after reperfusion in small intestinal ischemia and liver transplantation. Thromboelastography (TEG) is a coagulation test performed whole on blood. The aims of this study were to assess coagulation derangements during bowel transplantation to define appropriate modalities of intraoperative coagulation monitoring. A secondary endpoint was to determine whether measurements of coagulation derangements were useful to estimate small intestinal I/R injury. MATERIALS AND METHODS: We recruited 19 patients who had undergone elective small bowel transplantation for primary short-gut syndrome. We divided our patients into two groups depending on their reperfusion injury as evaluated with a biopsy after reperfusion: group A composed of eight patients who had a reperfusion injury: group B composed of 11 patients who did not experience this problem. We measured five thromboelastogram indicators (r, k, angle, MA, CL30) at defined intervals: dissection phase (T1), vascular anastomoses phase (T2) as well as 30 minutes (T3) and 120 minutes (T4) after reperfusion during the intestinal reconstruction phase. RESULTS: We did not observe any significant difference between intraoperative blood loss, core temperature, or volume of fluid fresh frozen plasma, or platelet administration. Angle and MA were decreased significantly among patients with reperfusion injury. DISCUSSION: Patients showed a hypocoagulation pattern during all the manipulations. This derangement did not depend on the ischemia time. In patients with I/R injury the angle and MA did not change during ischemia, but did change significantly upon reperfusion. Several mechanisms may cause coagulation derangements. During the ischemic period, there may be damage to the vascular bed of the ischemic organ. When arterial blood passes through the damaged vascular bed after reperfusion, platelet activation occurs to varying degrees, resulting in reduced platelet function. CONCLUSION: Further studies are needed to confirm this preliminary work, which was limited by the low number of patients, in order to elucidate relevant mechanisms and develop predictive algorithms.

Right ventricular end-diastolic volume index as a predictor of preload status in patients with low right ventricular ejection fraction during orthotopic liver transplantation.

OBJECTIVE: The objective of this study was to compare the accuracy of 2 variables: pulmonary artery occlusion pressure (PAOP) and right ventricular end diastolic volume index (RVEDVI) as predictors of the hemodynamic response to fluid challenge as well as definition of the overall correlation between RVEDVI and change in PAOP, right ventricular ejection fraction (RVEF), central venous pressure (CVP), and determination of the right ventricular function during orthotopic liver transplantation. MATERIALS AND METHODS: A modified pulmonary artery catheter equipped with a fast response thermistor was used to determine RVEF, allowing calculation of RVEF end-diastolic volume index (EDVI, as the ratio of stroke index [SI] to EF). The above-mentioned hemodynamic measures were taken in 4 phases: T0, after induction of anesthesia; T1, during anhepatic phase; T2, 30' after graft reperfusion; and T3, at the end of surgery. RESULTS: The variation of the REF value was 36 +/- 4% and 39 +/- 6%. Linear regression analysis showed a significant correlation between RVEDVI (range, 133 +/- 33-145 +/- 40 mL/m(2)) and stroke volume index (SVI) in each phase (r(2) = 0.49, P < .01; r(2) = 0.57, P < .01) at T0 and T1, respectively, and at T2 and T3 (r(2) = 0.51, P < .01; r(2) = 0.44, P < .01), respectively. No significant variations in the linear regression analysis between RVEDVI, PAOP, CVP, and RVEF were observed. No relationship was found between PAOP (range, 10 +/- 2-6 +/- 2 mm Hg) and SVI. CONCLUSION: RVEDVI may be the best clinical estimate of right ventricular preload. In fact, minor changes of RVEF have been recorded, confirming that RV function was not altered during uncomplicated orthotopic liver transplantation.