Correction of Coagulation Defect in Thoracoabdominal Aneurysm Repair by Mesenteric Shunting

The authors have previously characterized laboratory coagulation abnormalities in patients undergoing thoracoabdominal aneurysm (TAA) repair as a reduction in clotting factor activity and an increase in the fibrinolysis that occurs after supraceliac clamping. A return to normal in these patients did not occur until the time of skin closure and was influenced by fresh frozen plasma (FFP) administration. To test the hypothesis that shortening the mesenteric ischemic time would mitigate the defect earlier in the operative course, the authors developed a technique of mesenteric shunting during TAA repair and studied coagulation response prospectively. Twelve consecutive elective patients had TAA repair carried out in standard fashion. No heparin was used. After completion of the proximal anastomosis, a coronary perfusion catheter was secured inside a previously sewn graft side arm and inserted into either the superior mesenteric artery or the celiac axis; the graft was clamped below the side arm. Blood levels of fibrinogen, F1.2, D-dimer, and Factors II, V, VII, VIII, IX, X, XI, and XII were analyzed at induction, immediately prior to mesenteric shunt insertion, at reimplantation of the visceral button and 30 minutes after visceral button reimplantation. Clamp times, volume and timing of blood products, and clinical outcomes were recorded prospectively. A two-sided, paired t test (pairwise/intersample) was applied for each factor studied. There was no coagulopathic bleeding. Indicators of fibrinolysis (fibrinogen, D-dimer) continued to rise throughout the procedure as had been true in our previous series. However, clotting factors returned to baseline shortly after mesenteric shunting and prior to administration of exogenous clotting factors. The return to baseline of the coagulation factors studied began at the time of the insertion of a mesenteric shunt. Visceral perfusion appears to have an impact on coagulation response. Earlier reperfusion may help extend the window of operative time by limiting coagulopathic bleeding that is occasionally seen during TAA repair.