Delayed neurologic deficit after endovascular abdominal aortic aneurysm repair

AbstractParaplegia or paraparesis secondary to spinal cord ischemia is an extremely rare complication after elective repair of abdominal aortic aneurysm. We report delayed paraparesis after endovascular abdominal aortic aneurysm repair in which one hypogastric artery was unintentionally occluded due to atheroembolism. A spinal catheter was immediately inserted after onset of paraplegia to promote cerebrospinal fluid drainage, which partially reversed the neurologic deficit. Our case underscores both the importance of the critical spinal collateral supply from the hypogastric artery and the role of spinal fluid drainage to maximize spinal cord perfusion in the setting of spinal cord ischemia. (J Vasc Surg 2003;37:690-2.

Left ventricular assist device inflow cannula position may contribute to the development of HeartMate II left ventricular assist device pump thrombosis

Background: Pump thrombosis (PT) is a dreaded complication after left ventricular assist device (LVAD) implantation. Problems with inflow cannula (IC) position may precipitate thrombus development. We sought to determine if IC position contributes to the development of PT.Methods: We conducted a retrospective review of 76 HeartMate II LVAD implants. The angle of the IC (AIC) to the horizontal plane was measured on chest x-rays. Patients who developed PT (PT group) were compared to the remaining patients (control group).Results: The mean age at implantation was 56 +/- 14 years, and 82% of the patients were male. Ten patients (13%) developed PT. Six (60%) required device exchange, and 4 (40%) were managed with anticoagulation and/or thrombolysis. The median AIC for all patients at implantation was 59 degrees (range, 38 degrees-98 degrees; 25th-75th interquartile range, 50 degrees-75 degrees). In the PT group, the median AIC was larger at the time of PT diagnosis compared to implantation (70 degrees vs 60 degrees, P = 0.005). In the control group, the median AIC was also larger at follow-up compared to implantation (61 degrees vs 58 degrees, P < 0.001) although to a lesser degree than in the PT group. No difference was seen in the median AIC between the PT group and the control group at implantation (60 degrees vs 58 degrees, respectively; P = 0.668) or at follow-up (70 degrees vs 61 degrees, respectively; P = 0.309). However, the median AIC at follow-up in the PT group was significantly larger than the median AIC at implantation in the control group (70 degrees vs 58 degrees, respectively; P = 0.014).Conclusion: The HeartMate II LVAD IC position contributes to the development of PT. Regular monitoring of cannula position may help identify patients at risk for this problem

Hydrogel Leclanché Cell: Construction and Characterization

A liquid-to-gel based Leclanch&eacute; cell has been designed, constructed and characterized for use in implantable medical devices and other applications where battery access is limited. This well-established chemistry will provide reliable electrochemical potential over a wide range of applications and the novel construction provides a solution for the re-charging of electrodes in hard to access areas such as an internal pacemaker. The traditional Leclanch&eacute; cell, comprised of zinc (anode) and manganese dioxide (cathode), conductive carbon powder (acetylene black or graphite), and aqueous electrolyte (NH4Cl and ZnCl2), has been suspended in an agar hydrogel to simplify construction while maintaining electrochemical performance. Agar hydrogel, saturated with electrolyte, serves as the cell support and separator allowing for the discharged battery suspension to be easily replaced once exhausted. Different amounts of active anode/cathode material have been tested and discharge characteristics have been plotted. It has been found that for the same amount of active material, acetylene black batteries have higher energy density compared to graphite batteries. Graphite batteries also discharge faster compared to acetylene black batteries. The results support further development of liquid batteries that can be replaced and refilled upon depletion

Preoperative vitamin K reduces blood transfusions at time of left ventricular assist device implant

Background: Congestive heart failure patients have hepatic congestion and abnormal coagulation profiles, increasing perioperative bleeding at time of ventricular assist device implantation. This study examined the impact of the preoperative administration of vitamin K on perioperative blood transfusion requirements. Methods: Retrospectively, 190 patients met inclusion criteria. Patients received no vitamin K (n = 62) or two 10-mg doses of intravenous vitamin K (n = 128) in the 24 hours before assist device implantation. Primary end points included transfusion requirements and reexploration rates for bleeding. Secondary outcomes were pump thrombosis and in-hospital mortality. Results: Baseline characteristics were similar between the 2 groups, with slight differences (not statistically significant) noted in the Interagency Registry for Mechanically Assisted Circulatory Support profile and total bilirubin levels. The only significant difference noted was the year of implantation (

Right heart failure in different left ventricular assist devices: single-center experience

Background: Right heart failure (RHF) following left ventricular assist device (LVAD) implantation increases morbidity and mortality for those who develop this complication. The purpose of this study was to assess the differences in incidence of RHF and outcomes between 2 types of continuous-flow LVADs at a single center. Methods: From January 2012 through June 2016, 184 patients were implanted with a continuous-flow LVAD (161 patients with the HeartMate II and 23 patients with the HeartWare device) either as a bridge to transplant or as destination therapy. Preoperative demographics, medical history, laboratory values, hemodynamics, and device type were analyzed to determine the variables associated with RHF and mortality. Results: Preoperative variables between the 2 groups were homogeneous. Most patients were Interagency Registry for Mechanically Assisted Circulatory Support profile 1 or 2 (92%) and New York Heart Association class IV (81%). More patients in the HeartMate II group had the indication of destination therapy (54% vs 30%), while more patients in the HeartWare group were implanted as bridge to transplant (70% vs 46%). RHF occurred in 57% of HeartWare patients compared to 16% of patients who received the HeartMate II (P=0.0001). After propensity score analysis, patients receiving the HeartWare device had increased odds for RHF (P=0.0013) and renal failure requiring dialysis (P=0.0135). The HeartMate II patient survival rate exceeded the HeartWare patient survival rate at 1 year (82.1% vs 67.2%) and at 2 years (74.6% vs 61.7%), but this difference did not achieve statistical significance (log-rank P=0.087). Conclusion: These results indicate that device type may affect RHF incidence and mortality. Studies at other centers are needed to replicate these findings