Reappraisal of the role of motor and somatosensory evoked potentials during open distal aortic repair.

OBJECTIVE: Intraoperative motor and somatosensory evoked potentials have been applied to monitor spinal cord ischemia during repair. However, their predictive values remain controversial. The purpose of this study was to evaluate the impact of motor evoked potentials and somatosensory evoked potentials on spinal cord ischemia during open distal aortic repair. METHODS: Our group began routine use of both somatosensory evoked potentials and motor evoked potentials at the end of 2004. This study used a historical cohort design, using risk factor and outcome data from our department's prospective registry. Univariate and multivariable statistics for risk-adjusted effects of motor evoked potentials and somatosensory evoked potentials on neurologic outcome and model discrimination were assessed with receiver operating characteristic curves. RESULTS: Both somatosensory evoked potentials and motor evoked potentials were measured in 822 patients undergoing open distal aortic repair between December 2004 and December 2019. Both motor evoked potentials and somatosensory evoked potentials were intact for the duration of surgery in 348 patients (42%). Isolated motor evoked potential loss was observed in 283 patients (34%), isolated somatosensory evoked potential loss was observed in 18 patients (3%), and both motor evoked potential and somatosensory evoked potential loss were observed in 173 patients (21%). No spinal cord ischemia occurred in the 18 cases with isolated somatosensory evoked potential loss. When both signals were lost, signal loss happened in the order of motor evoked potentials and then somatosensory evoked potentials. Immediate spinal cord ischemia occurred in none of those without signal loss, 4 of 283 (1%) with isolated motor evoked potential loss, and 15 of 173 (9%) with motor evoked potential plus somatosensory evoked potential loss. Delayed spinal cord ischemia occurred in 12 of 348 patients (3%) with intact evoked potentials, 24 of 283 patients (8%) with isolated motor evoked potentials loss, and 27 of 173 patients (15%) with motor evoked potentials + somatosensory evoked potentials loss (P < .001). Motor evoked potentials and somatosensory evoked potentials loss were each independently associated with spinal cord ischemia. For immediate spinal cord ischemia, no return of motor evoked potential signals at the conclusion of the surgery had the highest odds ratio of 15.87, with a receiver operating characteristic area under the curve of 0.936, whereas motor evoked potential loss had the highest odds ratio of 3.72 with an area under the curve of 0.638 for delayed spinal cord ischemia. CONCLUSIONS: Somatosensory evoked potentials and motor evoked potentials are both important monitoring measures to predict and prevent spinal cord ischemia during and after open distal aortic repairs. Intraoperative motor evoked potential loss is a risk for immediate and delayed spinal cord ischemia after open distal aortic repair, and somatosensory evoked potential loss further adds predictive value to the motor evoked potential.

Total Transfemoral Percutaneous Endovascular Aortic Arch Repair Using 3-Vessel Inner Branch Stent-Graft.

Endovascular repair has been introduced to decrease the morbidity and mortality associated with open surgical repair of aortic arch pathology. We illustrate total percutaneous transfemoral approach with a 3-vessel inner branch stent-graft to treat aortic arch aneurysm. (Level of Difficulty: Advanced.).

Propensity and impact of autologous platelet rich plasma use in acute type A dissection.

BACKGROUND: Coagulopathy in patients undergoing open repair of acute type A aortic dissection using cardiopulmonary bypass and hypothermic circulatory arrest is a common complication. Autologous platelet rich plasma is an intraoperative blood conservation technique, which has been shown in previous studies to promote hemostasis, leading to a reduction of blood product transfusions during elective aortic surgery. The purpose of this study is to evaluate the effectiveness of autologous platelet rich plasma as a blood conservation technique during open surgical repair of acute type A aortic dissection. METHODS: We reviewed all acute type A aortic dissection cases using hypothermic circulatory arrest, excluding patients presenting in extremis. Perioperative transfusion requirements and clinical outcomes were analyzed. The end points analyzed included early mortality, postoperative stroke, renal dysfunction, prolonged ventilation, coagulopathy, and length of postoperative intensive care unit stay. Parsimonious and saturated propensity scores were calculated for platelet rich plasma use, and all outcomes were propensity adjusted. RESULTS: Between 2003 and 2014, 85 of 391 acute type A aortic dissection repairs used autologous platelet rich plasma. Mean age of patients was 58 ± 15 years, and 70% were male. Obstructive sleep apnea (22% vs 13%, P = .04) and baseline ejection fraction (57% ± 6.7% vs 55% ± 10%; P = .014) were higher in the autologous platelet rich plasma group. Intraoperative propensity-adjusted blood products, 2 units fewer packed red blood cells (P = .001), 4 units fewer fresh-frozen plasma (P = .001), 6 units fewer platelets (P = .001), 1.3 units fewer cell-savers (P = .002), and 5 units fewer cryoprecipitate (P = .001) were significantly reduced by autologous platelet rich plasma use. Significant unadjusted reduction in postoperative reoperation for bleeding (8% vs 17%, P = .046) after autologous platelet rich plasma was reported, although propensity adjustment eliminated significance (P = .079). No difference in stroke, cardiac, or renal complications was observed. Postoperative transfusion needed during the first 3 days was significantly reduced in the autologous platelet rich plasma group: 2 units fewer packed red blood cells (P = .13), 2 units fewer fresh-frozen plasma (P = .018), and 5 units fewer platelets (P = .001), when compared with those without autologous platelet rich plasma. Ventilation time was reduced by 3 days (P = .002), and intensive care length of stay was reduced by 3 days (P = .063) after intraoperative autologous platelet rich plasma use. CONCLUSIONS: The use of autologous platelet rich plasma in patients undergoing open repair of acute type A aortic dissection was associated with a reduction in intraoperative and postoperative blood transfusions, as well as decreased early postoperative morbidity.

Removal of heavy metal ions by magnetic chitosan nanoparticles prepared continuously via high-gravity reactive precipitation method.

This study aimed to provide a continuous method for the preparation of magnetic Fe3O4/Chitosan nanoparticles (Fe3O4/CS NPs) that can be applied to efficient removal of heavy metal ions from aqueous solution. Using a novel impinging stream-rotating packed bed, the continuous preparation of Fe3O4/CS NPs reached a theoretical production rate of 3.43kg/h. The as-prepared Fe3O4/CS NPs were quasi-spherical with average diameter of about 18nm and saturation magnetization of 33.5emu/g. Owing to the strong metal chelating ability of chitosan, the Fe3O4/CS NPs exhibited better adsorption capacity and faster adsorption rates for Pb(II) and Cd(II) than those of pure Fe3O4. The maximum adsorption capacities of Fe3O4/CS NPs for Pb(II) and Cd(II) were 79.24 and 36.42mgg-1, respectively. In addition, the Fe3O4/CS NPs shown excellent reusability after five adsorption-desorption cycles. All the above results provided a potential method for continuously preparing recyclable adsorbent with a wide prospect of application in wastewater treatment.

Adopting the American anesthesia oral examination in China: value and roadblocks.

The quality and standardized training and certification of young physicians is key to the quality of health care in the future. In contrast to the American system, there is no nationwide and standardized oral examination in the training and certification process for anesthesiologists in China. The adoptability of the American anesthesia oral examination in China, as well as potential roadblocks, has not been specifically discussed. In this commentary, we share our experience of introducing the American oral examination to an audience of Chinese anesthesiologists and propose a pragmatic approach for adopting the anesthesia oral examination in China. This initiative has the potential to reform the current anesthesia training and certification process and improve the quality of anesthetic care in China.

Autologous platelet-rich plasma reduces transfusions during ascending aortic arch repair: a prospective, randomized, controlled trial.

BACKGROUND: Blood conservation using autologous platelet-rich plasma (aPRP), a technique of whole blood harvest that separates red blood cells from plasma and platelets before cardiopulmonary bypass with retransfusion of the preserved platelets after completion of cardiopulmonary bypass, has not been studied extensively. We sought to prospectively determine whether aPRP reduces blood transfusions during ascending and transverse aortic arch repair. METHODS: We randomly assigned 80 patients undergoing elective ascending and transverse aortic arch repair using deep hypothermic circulatory arrest to receive either aPRP (n = 38) or no aPRP (n = 42). Volume of aPRP retransfused was 726 ± 124 mL. The primary end point was transfusion amount. Secondary end points were death, stroke, renal failure, pulmonary failure, and transfusion costs. Perioperative transfusion rate was defined as blood transfusions given during surgery and up to 72 hours afterward. The surgeon and intensivist were blinded to the treatment arm. Because an anesthesiologist initiated the protocol, the surgeon was not aware of aPRP collection, as this occurred only after the sterile drape was in place. In addition, because cell salvage was performed on all cases, differentiation in perfusionist activities (during spinning of aPRP) was not evident. Platelet, fresh frozen plasma, and cryoprecipitate intraoperative transfusions were performed only after heparin was reversed and the patient was judged as coagulopathic on the basis of associated criteria: cryoprecipitate transfusion for fibrinogen level less than 150 µg/dL, platelet transfusion for platelet count less than 80,000, and fresh frozen plasma when thromboelastogram test was suggestive or a partial thromboplastin time was greater than 55 seconds, and prothrombin time was greater than 1.6 seconds. RESULTS: Early mortality, stroke, and respiratory complications were similar between groups. Only acute renal failure was reduced in the aPRP group, 7% versus 0% (p < 0.014). Mean transfusion rate of packed red blood cells was reduced by 34%, fresh frozen plasma by 52.8%, cryoprecipitate by 70%, and platelets by 56.7% in the aPRP group (p < 0.02). Hospital length of stay (9.4 ± 5.3 days versus 12.7 ± 6.3 days; p < 0.014) and transfusion costs ($1,396 ± $1,755 versus $2,762 ± $2,267; p < 0.004) were reduced in the aPRP group. CONCLUSIONS: The use of aPRP reduced allogeneic transfusions during ascending and transverse aortic arch repair with deep hypothermic circulatory arrest. This translated to less acute renal failure, decreased length of stay, and lower transfusion costs. Further studies examining the coagulation factors of aPRP are required.

Analysis of autologous platelet-rich plasma during ascending and transverse aortic arch surgery.

BACKGROUND: Coagulopathy is a common complication after ascending and transverse arch aortic surgery with profound hypothermic circuit arrest (PHCA). Blood conservation strategies to reduce transfusion have been ongoing and involve multiple treatment modalities in modern cardiac surgery. The purpose of this study is to evaluate the effectiveness of autologous platelet-rich plasma (aPRP) as a blood conservation technique to reduce blood transfusion in ascending and arch aortic surgery. METHODS: Between 2003 and 2009, we retrospectively reviewed 685 cases of ascending aorta and transverse arch repair using PHCA. A total of 287 patients in which aPRP was used (aPRP group) were compared with 398 patients who did have aPRP (non-aPRP group). Perioperative transfusion requirements and clinical outcomes that included early mortality, postoperative stroke, renal dysfunction, prolonged ventilation, coagulopathy, and length of postoperative intensive care unit stay were analyzed. The data were analyzed by mean and frequency for continuous variables and qualitative variables. To account for potential selection bias, 2 types of propensity analysis were performed. RESULTS: In both unadjusted and adjusted analysis, perioperative transfusions were fewer in the aPRP group compared with the non-aPRP group: (3.9 units fewer packed red blood cells, 4.5 units fewer fresh frozen plasma, 7.9 units fewer platelets, and 6.8 units fewer cryoprecipitate). In all analyses, postoperative morbidity (stroke, duration of mechanical ventilation, and intensive care unit stay) were significantly improved. Hospital mortality rate was not significantly decreased. CONCLUSIONS: The utilization of aPRP was associated with a reduction in allogeneic blood transfusions as well as a decrease in early postoperative morbidity during repairs of the ascending and transverse arch aorta using PHCA.