Effects Of Deep Hypothermic Circulatory Arrest Research Articles

Long-Term Out come Evaluation in Patient Undergoing Deep Hypo-thermic Circulatory Arrest in Aortic Arch Surgery

Background: Aortic dissection is usually associated with low survival rates due to high prehospital and perioperative mortality, in addition with increased risk of postoperative complication in survivals. Since 1985, deep hypothermic circulatory arrest (DHCA) is often used in aortic arch surgery with main advantage to provide bloodless surgical field while protecting brain tissue during hypothermia. Nevertheless, it still raises concern of increasing neurologic sequelae and a potential decrease of long-term quality of life. The aim of study: To evaluate the effect of DHCA used in aortic surgery on long-term quality of life. Methods: In this observational case series we included a total of 24 patients who had aortic arch surgery requiring DHCA in the Pauls Stradins Clinical University Hospital Cardiac Surgery center, from January 2019 to December 2020. Seven patients were excluded due to intrahospital death. For the rest of the patients Quality of life (QOL) was evaluated using RAND SF36 questionnaire and MMSE test. Data regarding demographics, clinical characteristics, surgery type, duration of circulatory arrest, rectal and bladder temperatures were collected and analyzed using the SPSS 23 Statistics software IBM SPSS Statistics 21 (IBM Corporation, NY, USA). Statistical significance was assumed as two- tailed p <0.05. Results: A total of 17 patients were analyzed, we had 12 (71%) males and 5 (29%) females. A mean age was 60.71 (±13.8 SD) years, leading co-morbidity was hypertension – 11 (64.7%). There were 6 (35.3%) elective and 11 (64.7%) acute surgeries. Stan-ford A dissection (82.4%) constituted the main part of all cases. A 94.7% had aortic arch replacement. Most common postopera-tive complication was wound infection- 29.4%. The mean cardiopulmonary bypass time, aortic cross-clamping and reperfusion time was 212 (±38.3, SD), 124 (±33.8, SD) and 70.2 (±32.9, SD) minutes, respectively. Core temperature during DHCA was 23.2 Cº (±3.2, SD) and a rewarming rate was 0.12 (±0.07, SD) Cº/min. No significance correlation between RAND SF36 questionnaire score (QoL questionnaire) and lowest DHCA temperature, aortic cross - clamping, reperfusion time, CPB time was observed, respectively - p=0.367, p=0.544, p=0.619, p=0. We found statistically significant moderate strength correlation between QOL and rewarming rate (r=0.550; p=0.022). Mean RAND SF36 questionnaire score was 71.9±10. and mean MMSE score was 27.9±5,3. Conclusions: We found no correlation between quality of life and lowest temperature during surgery, aortic cross- clamping time, reperfusion time, however we found positive moderate strength correlation between rewarming rate and quality of life. Patient quality of life after surviving aortic arch surgery and deep hypothermic circulatory arrest compared to general healthy population quality of life is slightly reduced. Mini-mental state exam and RANDO short form health survey can be useful scoring system to evaluate patient quality of life.

Plasma proteomic changes during hypothermic and normothermic cardiopulmonary bypass in aortic surgeries.

Deep hypothermic circulatory arrest (DHCA) is a protective method against brain ischemia in aortic surgery. However, the possible effects of DHCA on the plasma proteins remain to be determined. In the present study, we used novel high-throughput technology to compare the plasma proteomes during DHCA (22°C) with selective cerebral perfusion (SCP, n=7) to those during normothermic cardiopulmonary bypass (CPB, n=7). Three plasma samples per patient were obtained during CPB: T1, prior to cooling; T2, during hypothermia; T3, after rewarming for the DHCA group and three corresponding points for the normothermic group. A proteomic analysis was performed using isobaric tag for relative and absolute quantification (iTRAQ) labeling tandem mass spectrometry to assess quantitative protein changes. In total, the analysis identified 262 proteins. The bioinformatics analysis revealed a significant upregulation of complement activation at T2 in normothermic CPB, which was suppressed in DHCA. These findings were confirmed by the changes of the terminal complement complex (SC5b-9) levels. At T3, however, the level of SC5b-9 showed a greater increase in DHCA compared to normothermic CPB, while 48 proteins were significantly downregulated in DHCA. The results demonstrated that DHCA and rewarming potentially exert a significant effect on the plasma proteome in patients undergoing aortic surgery.

Deep Hypothermic circulatory arrest does not impair neurodevelopmental outcome in school-age children after infant cardiac surgery

The purpose of this study was to assess deep hypothermic circulatory arrest (DHCA) as a modifier of neurodevelopmental (ND) outcomes in preschool children after cardiac surgery in infancy for repair of congenital heart defects (CHD). This is a planned analysis of infants enrolled in a prospective study of apolipoprotein E polymorphisms and ND outcome after cardiac surgery. The effect of DHCA was assessed in patients with single or biventricular CHD without aortic arch obstruction. Neurodevelopmental assessment at 4 years of age included cognition, language, attention, impulsivity, executive function, social competence, and visual-motor and fine-motor skills. Patient and procedural variables were evaluated in univariate and multivariate models. Neurodevelopmental testing was completed in 238 of 307 eligible patients (78%). Deep hypothermic circulatory arrest was used at the discretion of the surgeon at least once in 92 infants (38.6%) with a median cumulative duration of 36 minutes (range, 1 to 132 minutes). By univariate analysis, DHCA patients were more likely to have single-ventricle CHD (p = 0.013), lower socioeconomic status (p < 0.001), a higher incidence of preoperative ventilation (p < 0.001), and were younger and smaller at the first surgery (p < 0.001). By multivariate analysis, use of DHCA was not predictive of worse performance for any ND outcome. In this cohort of children undergoing repair of CHD in infancy, patients who underwent DHCA had risk factors associated with worse ND outcomes. Despite these, use of DHCA for repair of single-ventricle and biventricular CHD without aortic arch obstruction was not predictive of worse performance for any ND domain tested at 4 years of age.

Clinical application of cerebral oxygenation monitoring during aortic aneurysm operation

To analyze the correlation between cerebral oxygenation and cerebral complications after aortic aneurysm operation and to evaluate the protective effects of DHCA and/or ASCP during aortic aneurysm operation. Thirty patients with aortic aneurysm, 24 with Stanford type A dissection, 4 with Stanford type B dissection, 1 with degenerative aneurysm in ascending and arch aorta, and 1 with false aneurysm in thoraco-abdominal aorta, 23 males and 7 females, aged 44 +/- 12, underwent aorta operation with circulatory arrest were alternatively allocated to two groups: 22 patients underwent aortic arch replacement under deep hypothermic circulatory arrest (DHCA) plus antegrade selective cerebral perfusion (ASCP), and 8 patients underwent descending thoracic aorta replacement under DHCA only. There was no significant difference in the lowest core temperature, hematocrit at lowest core temperature, and velocity of rewarming between these 2 groups. Near-infrared spectroscopy (NIRS) was used to continuously monitor the cerebral tissue oxygenation index (TOI) percutaneously. The mean circulatory arrest time in the DHCA + ASCP group was 23.25 min, significantly longer than that of the DHCA group (16.67 min, P = 0.022). Cerebral complication occurred in 8 patients after aortic operation (complication group). The baseline TOI of the complication group was 70% +/- 5%, and the maximum decrease in TOI was 58% +/- 8%; and the baseline TOI of the non-complication group was 69% +/- 8%, and the maximum decrease in TOI was 55% +/- 8%; however, there were no significant differences between these 2 groups (both P > 0.05). The TOI decrease was more significant in the DHCA group than in the DHCA + ASCP group. During circulatory arrest, the levels of TOI were higher than the baseline level all along in the ASCP group and were lower than the baseline level 3 to 10 minutes after arrest in the DHCA group. The duration of TOI less than the baseline level in the DHCA group was significantly longer than that in the ASCP group. Mild decrease of TOI is not significantly correlated to the occurrence of complication. DHCA + ASCP is more effective in brain protection compared with only DHCA.

Effects of Deep Hypothermic Circulatory Arrest With Retrograde Cerebral Perfusion on Electroencephalographic Bispectral Index and Suppression Ratio

No systematic study has been conducted to investigate effects of deep hypothermic circulatory arrest (DHCA) on electroencephalographic bispectral index (BIS) and suppression ratio (SR). Thus, the effects of DHCA were evaluated on BIS and SR. A prospective clinical study. University hospital (single institute). Twenty consecutive patients undergoing thoracic aortic surgery using DHCA under narcotics-sevoflurane anesthesia. BIS and SR were monitored during cardiopulmonary bypass, simultaneously with nasopharyngeal temperature (NPT). BIS decreased to 0 with induction of deep hypothermia and rose again with rewarming, although rates of BIS changes in response to cooling and rewarming varied widely among patients. Typically, BIS decreased slowly until NPT reached 26 degrees C during cooling and then it began to decrease rapidly and reached 0 at 17 degrees C, in inverse proportion to SR, which increased rapidly with deep hypothermia and reached 100% at 17 degrees C. When SR was 50% or more, BIS was determined by SR according to the expression: BIS = 50-SR/2. With rewarming, BIS rose again and returned to precooling baseline levels. Time to the beginning of the BIS recovery significantly correlated with duration of DHCA. With induction of deep hypothermia, BIS decreased in a biphasic manner to 0 at rates varying among patients. With rewarming, BIS rose again at rates extremely widely varying among patients. The rate of BIS recovery was related to duration of DHCA. BIS may be capable of conveniently tracing suppression and recovery of a part of cerebral electrical activity before, during, and after DHCA.

Con: Deep hypothermic circulatory arrest must be used selectively and discreetly

F OR SEVERAL DECADES, surgical teams have used the protective benefits of deep hypothermia (16°C to 2OT) for repair of complex heart defects during surgery.‘~5 Early clinical success using this technique led to the additional application of total circulatory arrest for intracardiac repair.6 Currently, the application of deep hypothermic circulatory arrest (DHCA) includes its use for intracardiac repair of congenital heart defects in infancy, acquired aortic arch disease in adults, and certain neurosurgical procedures. The putative advantages of DHCA include the shortening of overall cardiopulmonary bypass (CPB) time; a more exacting anatomic repair in a bloodless, cannulafree operative field; and the ability to perform operations on the aortic arch that otherwise cannot be repaired.’ As superb surgical results for complex congenital and acquired heart defects have been achieved, this progress has now led to the examination of the quality of life of patients surviving these operations. While the development and success of the modern pump-oxygenator in clinical practice has been truly remarkable, advances in cerebral protection during cardiac surgery have neither come as quickly nor gone as far as those in myocardial protection. As perioperative death (usually cardiac in origin) has declined over time, even in high-risk patient populations, postoperative neuropsychological dysfunction has emerged as an increasingly important aspect of cardiac surgical morbidity. With the availability of sophisticated techniques for examining the central nervous system and the growing concern for the quality of life, the effects of DHCA have become more widely investigated in recent years. The initial interest in this technique is now being met with mixed enthusiasm. The avoidance of DHCA at some institutions in favor of continuous, low-flow CPB is reflective of the concern for DHCA and its potential for neuropsychological injury. Because the brain is the organ most vulnerable to ischemia, concern has been expressed over the years regarding the safety of DHCA, specifically, the effect of DHCA on brain structure and function. Despite the routine clinical application of DHCA, now into its third decade, the technique is largely empirical, and mechanisms of cellular integrity and protection are poorly understoodP