This study examined outcomes in patients with left ventricular assist device (LVAD) and extracorporeal membrane oxygenation (ECMO) requiring noncardiac surgical procedures and identified factors that influence outcomes. All patients with mechanical circulatory support (MCS) devices at our institution from 2002 to 2013 undergoing noncardiac surgical procedures were reviewed. There were 148 patients requiring MCS during the study period, with 40 (27.0%) requiring 62 noncardiac surgical procedures. Of these, 29 (72.5%) had implantable LVAD and 11 (27.5%) were supported with ECMO. The two groups were evenly matched with regard to age (53.6 vs. 54.5 years, p = 0.87), male sex (71.4 vs. 45.5%, p = 0.16), and baseline creatinine (1.55 vs. 1.43 mg/dl, p = 0.76). Patients on ECMO had greater demand for postoperative blood products (0.8 vs. 2.8 units of packed red blood cells, p = 0.002) and greater postoperative increase in creatinine (0.07 vs. 0.44 mg/dl, p = 0.047). Median survival was markedly worse in ECMO patients. Factors associated with mortality included ECMO support, history of biventricular assist device, and postoperative blood transfusion. Preoperative aspirin was associated with survival. These findings demonstrate the importance of careful surgical hemostasis and minimizing perioperative blood transfusions in patients on MCS undergoing noncardiac surgical procedures. In addition, low-dose antiplatelet therapy should be continued perioperatively.
We thank Drs. Lieske and Birkenfeld (1) for their comments. We agree that in our article (2) we did not address the question of whether or not the activating effects of insulin on endoplasmic reticulum (ER) stress will become resistant in the setting of obesity-associated insulin resistance and that it would be important to understand whether or not insulin-resistant humans remain sensitive to insulin-induced ER stress. However, we have addressed these important points in subsequent studies (G.B., unpublished observations), which showed that insulin resistance inhibited insulin-induced ER stress responses in adipose tissue of nondiabetic and diabetic subjects. Based on these results, we hypothesized that insulin resistance in adipose tissue may be a protective mechanism against hyperinsulinemia-induced ER stress. A manuscript containing these results has been submitted for review.
Primary aortoenteric fistulae are difficult conditions to diagnose and manage. A 35-year-old male developed massive upper gastrointestinal hemorrhage due to a primary aortoduodenal fistula. Previous radiation therapy and retroperitoneal lymph node dissection for germ cell cancer with resultant dense retroperitoneal fibrosis made open aortic repair impossible. Endovascular balloon occlusion of the aorta and stent graft repair of the primary aortoduodenal fistula was performed. At 1-year follow-up, there is no clinical or radiographic evidence of stent-graft infection. Endovascular techniques and repair are important approaches to consider during the management of complicated primary aortoenteric fistulae when open surgical repair is not feasible.
