Simple method to improve the effectiveness of brain retrograde perfusion during total circulatory arrest

Very Mild Hypothermia (35°C) Postischemia Reduces Infarct Volume and Blood/Brain Barrier Breakdown Following tPA Treatment in the Mouse

Reperfusion therapies for stroke diminish in effectiveness and safety as time to treatment increases. Hypothermia neuroprotection for stroke is established, but its clinical translation has been hampered by uncertainties regarding optimal temperature and complications associated with moderate hypothermia. Also, hypothermia targeting temperatures of 32-33°C is associated with clinical and logistical problems related to induction and adverse side effects. We hypothesized that ischemic damage and tPA-exacerbated blood/brain barrier (BBB) breakdown produced following 30 minutes of middle cerebral artery occlusion and either 1 hour of saline or tPA infusion would be reduced by treatment with very mild cooling of 1.5°C for 48 hours followed by 24 hours of gradual rewarming. Infarct volume was reduced by 29.6% (p<0.001) and 41.9% (p<0.001) in hypothermic-tPA (Hypo_tPA)-treated and hypothermic-saline (Hypo_Sal)-treated animals compared to normothermic-tPA (Norm_tPA) and saline (Norm_Sal)-treated animals, respectively. Hypothermia also reduced IgG extravasation in tPA-treated, but not saline-treated groups compared to their normothermic controls (p<0.001). The ipsilateral-contralateral changes in optical density for IgG extravasation were 18.4% greater in the Norm_tPA than Norm_Sal (p<0.001) group. The ipsilateral-contralateral changes in optical density for IgG extravasation were reduced by 17.8% (p<0.001) in the Hypo_tPA compared to Norm_tPA group. No significant mean difference in IgG extravasation was seen between Hypo_tPA and Hypo_Sal groups (p>0.05). Very modest hypothermia to reduce the BBB breakdown could improve the availability and safety of reperfusion treatments for stroke.

Clinical Results of Ascending Aorta and Aortic Arch Replacement under Moderate Hypothermia with Right Brachial and Femoral Artery Perfusion

Background

Selective antegrade perfusion via axillary artery cannulation along with circulatory arrest under deep hypothermia has became a recent trend for performing surgery on the ascending aorta and aortic arch and when direct aortic cannulation is not feasible. The authors of this study tried using moderate hypothermia with right brachial and femoral artery perfusion to complement the pitfalls of single axillary artery cannulation and deep hypothermia.

Materials and Methods

A retrospective analysis was performed on 36 patients who received ascending aorta or aortic arch replacement between July 2005 and May 2010. The adverse outcomes included operative mortality, permanent neurologic dysfunction and temporary neurologic dysfunction.

Results

Of these 36 patients, 32 (88%) were treated as emergencies. The mean age of the patients was 61.9 years (ranging from 29 to 79 years) and there were 19 males and 17 females. The principal diagnoses for the operation were acute type A aortic dissection (31, 86%) and aneurysmal disease without aortic dissection (5, 14%). The performed operations were ascending aorta replacement (9, 25%), ascending aorta and hemiarch replacement (13, 36%), ascending aorta and total arch replacement (13, 36%) and total arch replacement only (1, 3%). The mean cardiopulmonary bypass time was 209.4±85.1 minutes, and the circulatory arrest with selective antegrade perfusion time was 36.1±24.2 minutes. The lowest core temperature was 24±2.1℃. There were five deaths within 30 post-op days (mortality: 13.8%). Two patients (5.5%) had minor neurologic dysfunction and six patients, including three patients who had preoperative cerebral infarction or unconsciousness, had major neurologic dysfunction (16.6%).

Conclusion

When direct aortic cannulation is not feasible for ascending aorta and aortic arch replacement, the right brachial and femoral artery can be used as arterial perfusion routes with the patient under moderate hypothermia. This technique resulted in acceptable outcomes.

Recombinant activated factor VII for refractory bleeding after acute aortic dissection surgery: A propensity score analysis*

OBJECTIVE

The aim of this study was to assess safety and effectiveness of recombinant activated factor VII (rFVIIa) in patients with refractory bleeding undergoing acute aortic dissection surgery with deep hypothermic circulatory arrest.

DESIGN

Propensity score-matched analysis.

SETTING

University hospital.

PATIENTS

Twenty-three cardiac surgery patients receiving rFVIIa compared with 23 matched controls.

INTERVENTIONS

An intravenous bolus of rFVIIa (70 microg/kg) was administered at the end of a complete transfusion protocol. Five patients received rFVIIa in the operating room, and 18 patients received rFVIIa in the intensive care unit. Four of the intensive care unit patients required a second dose.

MEASUREMENTS AND MAIN RESULTS

Blood loss and transfusion requirements were significantly reduced in the period after rFVIIa administration. A highly significant reduction in hourly blood loss was found at -1 hr vs. 0 hrs and 0 hrs vs. 1 hr (-194 and -77.5 mL, respectively; both adjusted p < .001). In addition, significant improvements of international normalized ratio (p < .001), partial thromboplastin time (p < .001), platelet count (p < .001), fibrinogen (p < .001), and antithrombin (p < .001) were detected after rFVIIa administration. The two groups did not differ regarding adverse events.

CONCLUSIONS

rFVIIa was successfully used as an additional therapy both during and after acute aortic dissection surgery with deep hypothermic circulatory arrest, when bleeding was refractory to conventional methods. Randomized studies are necessary to confirm the safety and efficacy of rFVIIa in this setting.

Stanford type A aortic dissection with Child B liver cirrhosis

Cardiac surgery using cardiopulmonary bypass in patients with advanced liver cirrhosis has been infrequently performed, and reported to be too risky. Aortic dissection accompanied with liver cirrhosis is extremely rare. A 61-year-old woman who had aortic dissection and Child B liver cirrhosis underwent ascending aorta replacement. Liver protection during cardiopulmonary bypass was successfully accomplished by moderate hypothermia and use of an aortic occlusion balloon to maintain sufficient hepatic blood flow.

Aortic dissection and hypothermic arrest in a Jehovah's Witness patient: a case for recombinant factor VIIa?

PURPOSE

To present a case of survival of a cognitively intact Jehovah's Witness patient with an aortic dissection who underwent hypothermic arrest. Recombinant factor VIIa, but no blood products were administered.

CLINICAL FEATURES

An 83-yr-old female with an acute type A aortic dissection underwent emergent surgical repair. Proximal extension of the dissection necessitated prolonged cardiopulmonary bypass (CPB) and hypothermic circulatory arrest. Despite this, perioperative hemostatis was adequate. Recombinant factor VIIa 90 microg x kg(-1) i.v. was administered post-CPB. The patient had an uneventful postoperative course, and was discharged home neurologically intact.

CONCLUSIONS

Patients who conscientiously object to the transfusion of blood products may present a considerable anesthetic challenge, especially those at risk from coagulopathy associated with CPB and hypothermic circulatory arrest. Recombinant factor VIIa may play a role in hemostasis management of these individuals, however, well-designed randomized controlled trials need to be undertaken to establish the efficacy and risks related to this potential indication.

Selective antegrade cerebral perfusion attenuates brain metabolic deficit in aortic arch surgery: a prospective randomized trial

BACKGROUND

Aortic arch surgery has a high incidence of brain injury. This may in part be caused by a cerebral metabolic deficit observed after hypothermic circulatory arrest (HCA). We hypothesized that selective antegrade cerebral perfusion (SACP) would attenuate this phenomenon.

METHODS AND RESULTS

In a prospective randomized trial, 42 adult patients were allocated to either HCA (22) or SACP. HCA occurred at a nasopharyngeal temperature of 15 degrees C and SACP at a corporeal temperature of 25 degrees C with cerebral perfusion at 15 degrees C. Paired arterial and jugular venous samples were taken before and after arrest. Continuous transcranial Doppler monitoring of middle cerebral artery velocity (MCAV) was performed. Neuropsychometric testing was performed preoperatively and at 6 and 12 weeks postoperatively. There were 3 hospital deaths (7.1%), 2 strokes (4.8%), and 6 episodes of transient neurological deficit (14.3%). From before to after arrest, jugular bulb pO2 changed by -21.67 mm Hg (26.4) in the HCA group versus +2.27 mm Hg (18.8) in the SACP group (P=0.007). Oxygen extraction changed by +1.7 mL/dL (1.3) in the HCA group versus -1 mL/dL (2.4) in the SACP group (P<0.001). MCAV increased by 6.25 cm/s (9.1) in the HCA group and 19.2 cm/s (10.1) in the SACP group (P=0.001). Incidence of neuropsychometric deficit at 6 weeks was 6/12 (50%) in HCA patients and 8/10 (80%) in SACP patients (P=0.2), and at 12 weeks was 6/16 (38%) in HCA patients and 4/11 (36%) in SACP patients (P=1).

CONCLUSIONS

SACP attenuates the metabolic changes seen after HCA. Further studies are required to assess optimal perfusion conditions and clinical outcome.

Late occurrence of diffuse cerebral swelling after intracerebral hemorrhage in a patient with the HELLP syndrome--Case report

Hemolysis, elevated liver enzymes, and low platelet count (HELLP) syndrome can occur at any time in the course of pregnancy and is associated with many complications including fatal stroke. A 37-year-old female presented with HELLP syndrome causing an intracerebral hematoma, which was treated by evacuation and mild hypothermia. Unexpected diffuse cerebral swelling occurred on the 15th day of the initially favorable postoperative course. Considerable impairment of consciousness persisted despite conservative therapy. Serial computed tomographic findings indicated delayed cerebral vasospasm as the cause of the swelling. Particularly careful management is required even beyond the first 2 weeks for patients with stroke as a complication of HELLP syndrome.