Unilateral Selective Antegrade Cerebral Perfusion Research Articles

Aortic arch surgery at 32°C: mild hypothermia and unilateral antegrade cerebral perfusion.

With development of antegrade cerebral perfusion, the necessity of deep hypothermic circulatory arrest (CA) in aortic arch surgery has been called into question. To minimize the adverse effects of hypothermia, surgeons now perform these procedures closer to normothermia. This study examined postoperative outcomes of hemiarch replacement patients using unilateral selective antegrade cerebral perfusion and mild hypothermic CA. Single-centre retrospective review of 66 patients undergoing hemiarch replacement with mild hypothermic CA (32°C) and unilateral selective antegrade cerebral perfusion between 2011 and 2018. Antegrade cerebral perfusion was delivered using right axillary artery cannulation. Postoperative data included death, neurological dysfunction, acute kidney injury and renal failure requiring new dialysis. Additional intraoperative metabolic data and blood transfusions were obtained. Eighty-six percent of patients underwent elective surgery. Mean age was 67 ± 3 years. Lowest mean core body temperature was 32 ± 2°C. Average CA was 17 ± 5 min. No intraoperative or 30-day mortality occurred. Survival was 97% at 1 year, 91% at 3 years and 88% at 5 years. Permanent and temporary neurological dysfunction occurred in 1 (2%) and 2 (3%) patients, respectively. Only 3 (5%) patients suffered postoperative stage 3 acute kidney injury requiring new dialysis. Intraoperative transfusions occurred in 44% of patients and no major metabolic derangements were observed. In patients undergoing hemiarch surgery, mild hypothermia (32°C) with unilateral selective antegrade cerebral perfusion via right axillary cannulation is associated with low mortality and morbidity, offering adequate neurological and renal protection. These findings require validation in larger, prospective clinical trials.

Different hypothermic and cerebral perfusion strategies in extended arch replacement for acute type a aortic dissection: a retrospective comparative study

BackgroundThe optimal hypothermic level in total arch replacement with stented elephant trunk implantation for acute type A aortic dissection (aTAAD) has not been established, and the superiority of unilateral or bilateral cerebral perfusion remains a controversial issue. Therefore, we evaluated the application of moderate hypothermic circulatory arrest (MHCA) with a core temperature of 29 °C and bilateral selective antegrade cerebral perfusion in aTAAD treated by total arch replacement with stented elephant trunk implantation.MethodsFrom July 2019 to January 2020, 25 aTAAD patients underwent total arch replacement with stented elephant trunk implantation via MHCA (29 °C) and bilateral selective antegrade cerebral perfusion (modified group). Thirty-six patients treated by the same procedure with MHCA (25 °C) and unilateral selective antegrade cerebral perfusion during this period were selected as controls.ResultsThere were no differences between the two groups of patients in terms of age, sex, incidence of hypertension, malperfusion, and pericardial effusion, although the incidence of cardiac tamponade was higher in the modified group (control 2.8%, modified 20%; P = 0.038). The lowest mean circulatory arrest temperature was 24.6 ± 0.9 °C in the control group, and 29 ± 0.8 °C in the modified group (P < 0.001). In-hospital mortality was 4.9% (3/61) for the entire cohort (control 8.3%, modified 0; P = 0.262). The incidence of permanent neurologic deficit was 4.9% (control 8.3%, modified 0; P = 0.262). There were no significant differences in the occurrence of temporary neurological deficit, renal failure, and paraplegia between groups. The rate of major adverse events in the modified group was lower (30.6% vs. 4%, P = 0.019). A shorter duration of ventilation and ICU stay was identified in the modified group, as well as a reduced volume of drainage within the first 48 h and red blood cell transfusion.ConclusionsThe early results of MHCA (29 °C) and bilateral selective antegrade cerebral perfusion applied in total arch replacement with stented elephant trunk implantation for aTAAD were acceptable, providing similar inferior cerebral and visceral protection compared with that of the conventional strategy. A higher core temperature may account for the shorter duration of ventilation and ICU stay, as well as a reduced volume of drainage and red blood cell transfusion.

The Transcranial Doppler Sonography for Optimal Monitoring and Optimization of Cerebral Perfusion in Aortic Arch Surgery: A Case Series.

To analyze the feasibility and advantages of transcranial doppler sonography (TCD) for monitoring and optimization of selective cerebral perfusion (SCP) in aortic arch surgery. From April 2013 to April 2014, nine patients with extensive aortic pathology underwent surgery under moderate hypothermic cardiac arrest with unilateral antegrade SCP under TCD monitoring in our institution. Adequate sonographic window and visualization of circle of Willis were to be confirmed. Intraoperatively, a cerebral cross-filling of the contralateral cerebral arteries on the unilateral SCP was to be confirmed with TCD. If no cross-filling was confirmed, an optimization of the SCP was performed via increasing cerebral flow and increasing PCO2. If not successful, the SCP was to be switched to bilateral perfusion. Air bubble hits were recorded at the termination of SCP. A sonographic window was confirmed in all patients. Procedural success was 100%. The mean operative time was 298 ± 89 minutes. Adequate cross-filling was confirmed in 8 patients. In 1 patient, inadequate cross-filling was detected by TCD and an optimization of cerebral flow was necessary, which was successfully confirmed by TCD. There was no conversion to bilateral perfusion. Extensive air bubble hits were confirmed in 1 patient, who suffered a postoperative stroke. The 30-day mortality rate was 0.Conclusion: The TCD is feasible for cerebral perfusion monitoring in aortic surgery. It enables a confirmation of adequacy of cerebral perfusion strategy or the need for its optimization. Documentation of calcific or air-bubble hits might add insight into patients suffering postoperative neurological deficits.

Hypothermia and Selective Antegrade Cerebral Perfusion Is Safe for Arch Repair in Type A Dissection

Unilateral selective antegrade cerebral perfusion with moderate hypothermic circulatory arrest has been shown to be a safe and effective method of cerebral protection during surgery for acute type A dissection. This study evaluates the impact of this cerebral protection strategy on clinical outcomes after extended aortic arch reconstruction in patients undergoing emergent repair of acute type A dissection. A retrospective review from 2004 to 2016 at a US academic center of patients undergoing surgery for acute type A dissections using moderate hypothermic circulatory arrest and selective antegrade cerebral perfusion was performed. Patient data were abstracted from The Society of Thoracic Surgeons (STS) institutional database and patient charts. Cohorts were established based on extent of arch replacement: a hemiarch group and a transverse arch group were created. Owing to a dearth of events, a risk score was estimated using a logistic regression model with 30-day mortality as outcome and preoperative variables as predictors, including non-STS variables such as malperfusion. Postoperative outcomes were then adjusted in subsequent regression analyses for the estimated risk score. In all, 342 patients met inclusion criteria and were included for analysis (299 hemiarch, 43 transverse arch). The mean age was 55.4 years and not different between groups (p= 0.79). Preoperative comorbidities, including prior stroke, diabetes mellitus, and renal failure, were also similar between groups (p > 0.2). Inhospital mortality was 11.7% for the entire cohort (11.7% hemiarch, 9.3% transverse arch; p= 0.60), and the permanent stroke rate was 7.3% (7.7% hemiarch, 4.3% transverse arch; p= 0.47). Median circulatory arrest time was 38.9 ± 19.2 minutes (35.0 ± 13.2 hemiarch, 65.1 ± 30.1 transverse arch; p < 0.0001). Lowest median circulatory arrest temperature was 25.9° ± 3.1C° and not different between groups (25.9° ± 3.2°C hemiarch, 26.2° ± 2.6°C transverse arch; p= 0.50). In unadjusted analysis, no increase in operative mortality, temporary neurologic dysfunction, stroke, or renal failure was observed in the transverse arch group when compared with the hemiarch group. These results persisted when adjusted analysis was performed. Unilateral selective antegrade cerebral perfusion with moderate hypothermic circulatory arrest remains a safe strategy for cerebral protection during emergent surgical repair of acute type A dissection and provides equivalent outcomes for both limited and extensive aortic arch reconstruction. Based on these data, unilateral selective antegrade cerebral perfusion and moderate hypothermic circulatory arrest may represent an optimal strategy for cerebral protection in this acute setting.

Moderate hypothermic circulatory arrest in total arch repair for acute type A aortic dissection: clinical safety and efficacy.

Continued debates exist regarding the optimal temperature during hypothermic circulatory arrest (HCA) in aortic arch repair for patients with type A aortic dissection (TAAD). This study seeks to examine whether the use of moderate HCA in emergency aortic arch surgery provides comparable operative outcomes to deep HCA for patients with acute TAAD. We prospectively enrolled 74 consecutive patients (mean age 47.7±9.8 years, 54 males) with acute TAAD, who underwent emergency total arch replacement and frozen elephant trunk implantation under HCA (18-28 °C) with unilateral selective antegrade cerebral perfusion (uSACP). Patients were divided into two groups based on the nasopharyngeal temperature at the initiation of HCA: deep HCA (DHCA, <20 °C) in 35 (47.3%) and moderate HCA (MHCA, 20-28 °C) in 39 (52.7%). Operative outcomes including mortality, morbidity and visceral organ functions were compared between the two groups. The mean times of cardiopulmonary bypass (CPB) and aortic cross-clamp were 211±54 and 238±62 minutes (P=0.053) and 118±27 and 142±45 minutes (P=0.005) in the MHCA and DHCA groups, respectively. Operative mortality did not differ between two groups (10.2% in MHCA vs. 14.3% in DHCA groups, P=0.862). Nor did the incidence of morbidities differ between the two groups (P>0.05). The temporal trend in the changes of postoperative levels of creatinine, aspartate aminotransferase, total bilirubin and lactate did not differ between two groups (P>0.05). Multivariate analysis found that the temperature during HCA (MHCA vs. DHCA) did not affect operative mortality, morbidities and neurologic complications. Instead, CPB time (in minutes) was the risk factor for operative mortality (odds ratio, 1.032; 95% confidence interval, 1.004-1.061; P=0.023). Moderate HCA is associated with equivalent operative mortality and morbidity and visceral organ functions compared to deep HCA in patients with acute TAAD undergoing total arch replacement under uSACP. This study implies the clinical safety and efficacy of moderate HCA in emergency aortic arch repair for such patients, which provides equivalent cerebral and visceral organ protection while decreasing CPB and cross-clamp times without increasing the risk of operative mortality and morbidity.

Electroencephalography During Hemiarch Replacement With Moderate Hypothermic Circulatory Arrest

This study aimed to characterize intraoperative electroencephalography (EEG) during moderate hypothermic circulatory arrest (MHCA) with selective antegrade cerebral perfusion (SACP), which has not been described previously. This was a single-institution retrospective study of patients undergoing aortic hemiarch replacement using MHCA (temperatures <28°C at circulatory arrest [CA]) and unilateral SACP with EEG monitoring from July 1, 2013 to November 1, 2014. The EEG pattern was determined before and immediately after CA, as well as after establishment of SACP. Patient and procedural characteristics and outcomes were determined and compared after stratification by the presence of ischemic EEG changes. The study included 71 patients. Before CA, 47patients (66%) demonstrated a continuous EEG pattern, with or without periodic complexes, and 24 (34%) had a burst suppression EEG pattern. Immediately after CA, abrupt loss of electrocerebral activity occurred in 32patients (45%), suggestive of cerebral ischemia. Establishment of unilateral SACP rapidly restored electrocerebral activity in all but 2 patients. One patient had persistent loss of left-sided activity, which resolved after transition to bilateral SACP. Another patient had persistent global loss of activity and was placed back on cardiopulmonary bypass for further cooling before reinitiation of CA. No significant differences in characteristics or outcomes were assessed between patients with and without loss of EEG activity. Nearly half of patients undergoing hemiarch replacement with MHCA/SACP experience abrupt loss of electrocerebral activity after CA is initiated. Although unilateral SACP usually restores prearrest electrocerebral activity, intraoperative EEG may be particularly valuable for the identification of patients with persistent cerebral ischemia even after SACP.

Moderate Versus Deep Hypothermia With Unilateral Selective Antegrade Cerebral Perfusion for Acute Type A Dissection

Despite improved results with surgical therapy for acute type A aortic dissection (ATAAD), there remains a lack of consensus regarding the optimal method of cerebral protection and circulation management during ATAAD. The purpose of this study is to determine whether in the setting of antegrade cerebral perfusion, moderate hypothermic circulatory arrest (MHCA) provides equivalent cerebral and visceral protection as deep hypothermic circulatory arrest (DHCA) for patients undergoing emergent ATAAD repair. A review of the Emory aortic surgery database from 2004 to 2014 identified 288 patients who underwent ATAAD with right axillary artery cannulation, unilateral selective antegrade cerebral perfusion (uSACP), and hypothermic circulatory arrest (HCA). In all, 88 patients underwent HCA at 24 °C or lower (DHCA), and 206 patients underwent HCA at more than 24 °C (MHCA). Major adverse outcomes of death, stroke, temporary neurologic dysfunction, and dialysis-dependent renal failure were examined. The groups were well matched for age and major comorbidities. The DHCA patients underwent HCA at lower temperatures (DHCA 21.6 ± 3.1 °C vs MHCA 27.4 ± 1.6 °C, p < 0.01). There were no significant differences in cardiopulmonary bypass, cross-clamp, or HCA times. Mortality was 14.6% for DHCA patients, and 9.2% for MHCA patients (p = 0.17). There was no significant difference in stroke, temporary neurologic dysfunction, or dialysis-dependent renal failure. There was no association with either MHCA plus uSACP or DHCA plus uSACP and any of the major adverse outcomes (p > 0.05). Moderate HCA with uSACP is an effective circulation management strategy that provides excellent cerebral and visceral protection during emergent ATAAD repair. In the setting of antegrade cerebral perfusion, deep hypothermia does not provide any additional benefit.

Unilateral Versus Bilateral Antegrade Cerebral Protection During Aortic Surgery: An Updated Meta-Analysis

In the context of complex aortic surgery, despite the wide consensus about the use of moderate hypothermia in association with antegrade selective cerebral perfusion (ASCP), its bilateral administration is not always warranted. The aim of the present meta-analysis was to investigate outcomes of unilateral versus bilateral ASCP. Outcomes investigated were postoperative mortality and neurologic permanent and temporary disease (PND and TND); separate analysis of heterogeneity using the Cochrane Q statistic was used to perform comparisons. Circulatory arrest (CA) time and temperature, and sample size were explored as potential causes for heterogeneity with meta-regression analysis. The study population consisted of 3,723 patients receiving bilateral ASCP and 3,065 patients receiving unilateral ASC. Pooled analysis showed similar rates of postoperative mortality: 9.8% (95% confidence interval [CI], 7.8% to 12.3%) for bilateral ASCP versus 7.6% (95% CI, 5.7% to 10.2%) for unilateral ASCP; p= 0.19. Postoperative PND rates as well did not differ significantly: 6.9% (95% CI, 5.0% to 9.4%) for bilateral ASCP versus 5.8% (95% CI, 3.8% to 8.7%) for unilateral ASCP; p= 0.53. Similar results yielded from TND analysis: 9.3 % (95% CI, 7.0% to 12.2%) versus 6.5% (95% CI, 4.5% to 9.5%), respectively, p= 0.14. Meta-regression analysis showed that longer CA times were associated with significantly increased mortality only among patients administered with unilateral ASCP (model Q 65.8, p < 0.0001). Furthermore, higher CA temperatures were associated with significantly reduced rates of mortality (Q 64.1, p= 0.001), PND (Q 52.3, p= 0.01), and TND (Q 62.2, p= 0.002) in both groups. Unilateral versus bilateral ASCP administration did not result in different mortality and neurologic morbidity rates. Nevertheless, among prolonged CA times unilateral ASCP resulted in poorer outcomes with respect to bilateral ASCP. Furthermore, moderate hypothermia was associated with best outcomes in both groups.

Total arch replacement using moderate hypothermic circulatory arrest and unilateral selective antegrade cerebral perfusion

To examine the clinical outcomes and impact of using moderate hypothermic circulatory arrest (MHCA) and unilateral selective antegrade cerebral perfusion (uSACP) in the setting of total aortic arch replacement (TOTAL). From 2004 to 2012, 733 patients underwent open arch reconstruction with MHCA and SACP. Of these, 145 (20%) underwent TOTAL. Measured outcomes included death, stroke, temporary neurologic dysfunction (TND), and renal failure. Mean follow-up time was 33 months and ranged from 0 to 95 months. Core temperature at the onset of MHCA was 25.8°C. Cardiopulmonary bypass and myocardial ischemic times were 236 minutes and 181 minutes, respectively. Twenty-three patients (16%) underwent emergency repair of acute type A dissection. Fifty-four cases (37%) were reoperative and 52 (34%) were stage I elephant trunk procedures. Concomitant root replacement was performed in 50 (35%) patients, including 20 David V valve-sparing procedures. Mean duration of circulatory arrest was 55 minutes. Operative mortality was 9.7%. Overall incidence of stroke and TND was 2.8% and 5.6%, respectively. Four patients (2.8%) required postoperative dialysis. Seven-year survival was significantly reduced (P=.04) after repair of type A dissection (83.8%) compared with elective surgery (89.5%). Higher temperature during TOTAL was not found to be a significant risk factor for adverse events. TOTAL using MHCA and uSACP can be accomplished with excellent early and late results. MHCA was not associated with adverse neurologic outcomes or higher operative risk, despite prolonged periods of circulatory arrest.

Acute Type A Dissection: Impact of Antegrade Cerebral Perfusion Under Moderate Hypothermia

The optimal method of arterial cannulation and circulation management for acute type A aortic dissection (type A) remains debated. Moderate hypothermic circulatory arrest (MHCA) and unilateral selective antegrade cerebral perfusion (uSACP) is effective in the elective setting. In this study, the impact of MHCA and uSACP on outcomes for type A repair was evaluated. A retrospective review identified 346 patients who underwent type A repair under circulatory arrest, including 193 patients who had MHCA/uSACP. Measured outcomes included operative mortality, permanent neurologic deficit (PND) and temporary neurologic deficit, renal failure, and tracheostomy. Propensity-adjusted, multivariable logistic regression analysis was used to model adverse outcomes. The mean age of MHCA/uSACP patients was 56 years. The mean temperature during MHCA was 26.9 ± 2.0°C. Operative mortality for MHCA/SACP patients was 9.8% compared with 20.3% for the non-MHCA/SACP group (p < 0.01). Propensity score analysis found that MHCA/uSACP did not represent an adverse risk factor for mortality, temporary neurologic deficit, PND, renal failure, or the need for tracheostomy compared with non-MHCA/uSACP techniques. There was a 2.32-fold higher incidence of PND among patients who underwent cross-clamping of the dissected aorta during cooling before circulatory arrest (p < 0.05). Emergent type A repair can be accomplished with respectable operative risk using MHCA/uSACP. Cross-clamping the dissected aorta before MHCA increases the incidence of PND. These data suggest that MHCA/uSACP represents an effective circulation management strategy for patients undergoing repair of type A and obviates the need for deep hypothermic circulatory arrest.

Aortic arch surgery using moderate hypothermia and unilateral selective antegrade cerebral perfusion.

Cerebral protection and circulatory management remains a controversial issue in aortic arch surgery. The present study reported surgical outcomes of arch repair using moderate hypothermic circulatory arrest (MHCA) and unilateral selective antegrade perfusion (uSACP). From January 2004 and December 2012, 500 patients underwent hemiarch repair (HARCH) and 124 underwent total arch replacement (TARCH) utilizing moderate hypothermic circulatory arrest with unilateral selective antegrade cerebral perfusion of the right axillary artery. Emergent surgery was required in 142 (28.4%) of HARCH patients and 18 (14.5%) of TARCH patients. Mean arrest temperature ranged from 25.6-27.2 °C for elective and emergent operations in both groups. Mean circulatory arrest was 26.8 minutes for hemiarch repairs and 54.2 minutes for total arch replacement. Overall mortality was 6.6% for hemiarch repairs and 9.7% for total arch replacements. Hospital mortality was 4.5% (16/358) and 10.4% (11/106) in elective cases, and 12% (17/142) and 5.6% (1/18) in elective cases, for hemiarch and total arch replacements respectively. Permanent neurological deficit (PND) occurred in 3 total arch replacement cases (2.4%). Multivariate analysis demonstrated that temperature was not found to be an independent risk factor during hemiarch or total arch replacements for mortality, permanent or neurological deficits, or renal failure. Our approach for hemiarch and total arch repair utilizing MHCA and uSACP via the right axillary artery was associated excellent neurological and survival outcomes. Moderate hypothermia did not adversely impact cerebral or visceral organ protection.

Hemiarch Replacement at 28°C: An Analysis of Mild and Moderate Hypothermia in 500 Patients

During the past decade, use has increased of moderate hypothermic circulatory arrest with antegrade cerebral perfusion for cerebral protection during aortic arch operations. This study examined the use of mild hypothermia in conjunction with unilateral selective antegrade cerebral perfusion (uSACP) for hemiarch replacement for proximal aortic arch reconstruction. A retrospective review of the Emory Aortic Database identified 708 patients who underwent aortic arch replacement between 2004 and 2011. Of these, 500 underwent hemiarch replacement at temperatures of 22°C or higher with uSACP. Outcomes were analyzed and compared between 277 patients undergoing hemiarch at a temperature of 28.6°C (mild) and 233 undergoing hemiarch at a temperature of 24.3°C (moderate). Propensity scores were generated and analyzed between the groups to adjust for confounding factors such as selection bias. Operative mortality was equivalent between mild and moderate groups in elective (4.2% vs 4.8%, p=0.80) and emergency (7.7% vs 11.7%, p=0.43) settings. No differences occurred in the incidence of temporary neurologic dysfunction, dialysis-dependent renal failure, or mediastinal reexploration for bleeding between mild and moderate patients. The incidence of permanent neurologic deficit was significantly reduced in mild (2.5%) vs moderate patients (7.2%, p=0.01), which was confirmed by the propensity score analysis (adjusted odds ratio, 0.28; p=0.02). Hemiarch replacement can be safely performed at 28°C with uSACP in emergency and elective settings. Mild hypothermia with uSACP offers adequate levels of neurologic protection compared with deeper levels of hypothermia.

Invited Commentary

Invited Commentary

Moderate Hypothermia and Unilateral Selective Antegrade Cerebral Perfusion: A Contemporary Cerebral Protection Strategy for Aortic Arch Surgery

Cerebral protection techniques during aortic arch surgery include deep hypothermic circulatory arrest, retrograde cerebral perfusion, and (or) antegrade cerebral perfusion. It is unclear whether unilateral selective antegrade cerebral perfusion (uSACP) in the setting of moderate hypothermic circulatory arrest (MHCA) constitutes an effective cerebral protective strategy during aortic arch reconstruction. A retrospective review was performed for all aortic arch cases involving uSACP between January 2004 and December 2009. Of these 412 patients, 97 (24%) were treated emergently. Adverse outcomes included operative mortality, permanent neurologic dysfunction, temporary neurologic dysfunction, and renal failure requiring dialysis. Potential selection bias was controlled by the inclusion of 11 covariates. Multivariable logistic regression analysis was used to model adverse outcome as a function of MHCA and the covariates. Adjusted odds ratios were formulated along with 95% confidence intervals. Three hundred forty-four patients underwent hemiarch reconstruction and 68 patients underwent total arch replacement. The mean core body temperature at the initiation of uSACP was 25.7 degrees C + or - 2.8 degrees C with a uSACP time of 30 + or - 15 minutes. Overall operative mortality occurred in 29 (7.0%) patients. The incidence of permanent neurologic dysfunction and temporary neurologic dysfunction were 3.6% and 5.1%, respectively. Nineteen (4.6%) patients suffered postoperative renal failure requiring dialysis. In the adjusted analysis, MHCA was not found to be an independent predictor of mortality, permanent neurologic dysfunction, temporary neurologic dysfunction, or renal failure requiring dialysis. The MHCA with adjunctive uSACP is not an independent risk factor for adverse outcomes after aortic arch surgery. These data suggest that MHCA combined with uSACP represents an effective cerebral protective strategy in patients undergoing arch reconstruction in both the elective and emergent settings.

Simplified Cerebral Protection Using Unilateral Antegrade Cerebral Perfusion and Moderate Hypothermic Circulatory Arrest

Antegrade cerebral perfusion is one of the most reliable methods of organ protection during hypothermic circulatory arrest for aortic arch surgery. We used a simplified antegrade cerebral perfusion technique with low mortality and morbidity. Between January 2005 and August 2008, 21 patients underwent aortic arch surgery with unilateral antegrade selective cerebral perfusion through the brachiocephalic artery and moderate hypothermic circulatory arrest. The mean age for patients was 58.0+/-11.1 (27-82) years. Cardiopulmonary bypass was commenced and the ascending aorta was cross-clamped. Patients were cooled to 22-28 degrees C, whilst the proximal anastomosis was performed. The brachiochephalic artery was cannulated using a balloon tipped 15Fr catheter used for retrograde cardioplegia. Antegrade cerebral perfusion was established at the rate of 10 ml//kg/min. The perfusion pressure was controlled between 50 and 70 mm Hg whilst the distal anastomosis was completed. There were no operative deaths and no permanent neurological deficits. Four patients had temporary confusion. Mean antegrade cerebral perfusion time was 21.6+/-8.0 (12-48)min. Eight out of 20 patients had circulatory arrest at 28 degrees C and their mean circulatory arrest time was 22.8+/-4.7 (16-32)min. The mortality and neurological outcomes of aortic surgery using unilateral antegrade cerebral perfusion with moderate hypothermic circulatory arrest produced satisfactory results. Bilateral cannulation and deep hypothermia appear to be unnecessary in most cases. The coagulopathy from deep hypothermia is thereby avoided.

Unilateral Antegrade Selective Cerebral Perfusion in Aortic Surgery: Clinical Outcomes at Different Levels of Hypothermia

Although unilateral antegrade selective cerebral perfusion (UASCP) is considered a safe cerebral protection strategy during aortic surgery, an optimum temperature remains to be defined. This study compared outcomes in patients undergoing UASCP at either <24℃ or ≥24℃. Between 2000 and 2007, 104 consecutive patients underwent aortic surgery using UASCP. Patients were divided into two groups according to systemic temperature: group A comprised 64 patients undergoing deep hypothermia (<24℃); and group B comprised 40 patients undergoing moderate hypothermia (≥24℃). Both groups were similar in terms of the extent of aortic replacement and mean UASCP time. The total cardiopulmonary bypass time and aortic cross clamp time were longer in group A. Both groups were similar in terms of 30-day mortality rate (9.4% group A, 10.0% group B), and in terms of temporary (6.7% group A, 7.7% group B) and permanent (11.3% group A, 2.6% group B) neurological deficits. Multivariate analysis showed preoperative shock status was a risk factor for in-hospital mortality, and a preoperative history of a cerebral incident was a risk factor for permanent neurological deficit. UASCP under moderate hypothermia is a relatively safe and effective cerebral protective strategy during aortic surgery.