Temporary Neurologic Dysfunction Research Articles

Aortic root surgery in combination with hypothermic circulatory arrest: preserve or replace the aortic valve in the context of postoperative neurological outcome? A case match comparison

The objective of this study was to compare the results of elective composite (C) vs. David (D) operations in patients requiring additional aortic arch surgery using hypothermic circulatory arrest (HCA) and selective antegrade cerebral perfusion (SACP), with the focus on postoperative neurological outcome and quality of life (SF-36). Between November 1999 and March 2006, 333 patients underwent aortic root surgery and ascending aortic replacement with HCA and SACP at our institution. Out of these patients, 46 were matched with respect to age, gender, HCA-time and year of surgery. Two patients, one in each group, died during hospital stay (4%), with no late deaths. Follow-up was completed in 95% [64 (6-90) months]. Cardiopulmonary bypass (CPB) time (141 min vs. 168 min, P=0.007) and aortic cross-clamp time (99 min vs. 123 min, P=0.004) were significantly longer in the David-group. The incidence of temporary neurological dysfunction (TND 7%: D n=1, C n=2) was not different between groups, no permanent dysfunction could be detected. Follow-up SF-36 scores were comparable. The combination of aortic arch surgery with more time consuming valve sparing aortic root surgery does not increase the risk for adverse outcome applying comparable periods of HCA and SACP.

Thoracic aortic surgery with circulatory arrest and cold cerebral perfusion

This study was undertaken to identify pre- and perioperative risk factors to mortality and permanent neurological dysfunction (PND) and temporary neurological dysfunction (TND) in a large patient cohort, all operated under moderate hypothermic circulatory arrest (HCA) and selective antegrade cerebral perfusion (SACP) in a single centre. Between November 1999 and March 2006, 319 patients at a median age of 65 years (range 21-86, 201 male) underwent elective aortic arch surgery with moderate HCA at 25 degrees C and additional SACP at 14 degrees C. Sixty-nine had additional coronary artery bypass grafts or valve procedures. Ninety-four (29%) had total arch repair. Statistical analysis was carried out to determine the risk factors for 30-day mortality as well as for TND and PND. Overall mortality was 7.8% (15% in cases with repeat surgery vs 4.8% in nonrepeats, P=0.002). Twenty-seven (8.5%) suffered from PND, and six (22%) died during hospital stay (P=0.004). There was TND detected in 32 patients (10%). Stepwise logistic regression revealed age (P=0.001, OR 1.09/year), repeat surgery (P=0.008, OR 5.04), preoperative neurological events (P=0.004, OR 3.44), CAD (P=0.051, OR 3.58), and cardiopulmonary bypass duration (P<0.001, OR 1.01/min) as risk factors for mortality. The PND was associated with preoperative renal insufficiency (P=0.026, OR 3.34) and operation duration (P<0.001, OR 1.01/min), whereas TND occurred in patients with coronary artery disease (P=0.04, OR 2.41), and prolonged cardiopulmonary bypass duration (P=0.05, OR 1.01/min). Thoracic aortic surgery including aortic arch using HCA and SACP can be performed with excellent results in elective patients, especially those without previous surgery. Nevertheless PND is associated with high hospital mortality. Neurological complications seem to be strongly associated with general atherosclerotic changes as well as the extent of surgery.

Is there an Age Limit for Cardiac Surgery?

Introduction: This study was undertaken to analyze the risk of peri-operative mortality and morbidity after Cardiac Surgery with Cardio-pulmonary Bypass (CPB) in Patients above 85 years of age. Patients and Methods: Between 1/2001 and 05/2005 thirty-nine patients 85 years of age at the time of surgery were examined. Median age was 87 years (85–92), 13 were males and 26 were females. 11 (28%) were urgent cases, and 4 (10%) considered as emergencies. 12 (32.5%) received CABG, 14 (35%) aortic valve replacement and in 10 (25%) a combination of the both was performed. The remaining had a combination of CABG with other operations. Results: Peri-operative mortality was 7.7% (3 pts). All were in the emergency group. One of them went into the OR under cardio-pulmonary resuscitation and died in the OR. The other two were urgent cases who died later in the ICU due to cardiac failure. Temporary neurological dysfunction (TND) was found in 10.3% (4 pts) of the survivers. Mean mechanical ventilation time was 1.5 days, mean ICU stay was 3 days and mean hospital stay 9 days. Conclusion: Cardiac surgery with CPB in Octogenarians can be performed with an acceptable mortality in elective patients, but is associated with a dismal outcome under emergency conditions.

Ascending aortic cannulation in acute aortic dissection type A: the Hannover experience☆☆☆

The incidence of embolic events and of cerebral malperfusion in aortic dissection type A (AADA) must be viewed in the context of the existence of a number of possible cannulation techniques. Since femoral cannulation is thought to be associated with a higher risk of perfusion of the false lumen and retrograde embolization, techniques establishing antegrade flow may provide a better option. We describe herein our experience with ascending aortic cannulation in this special patient population. Between November 1999 and February 2006, 122 patients underwent operation for AADA with arterial access via the dissected ascending aorta. The aorta was cannulated at the site of the minimal distances of the dissected layers. Double purse-string sutures were used to support the cannula. Pressure monitoring in both radial arteries as well as bilateral cerebral oxygen saturation measurement helped to identify malperfusion after establishment of cardiopulmonary bypass. Aortic arch as well as aortic root surgery was performed, as dictated by the pathology. Selective antegrade cerebral perfusion and moderate hypothermia were used for brain and body protection. Malperfusion occurred in three patients (2.5%). Hospital mortality was 15% for the entire cohort (18 patients). Permanent neurological dysfunction was detected in 15 patients (12%), whereas temporary neurological dysfunction occurred in 21 (17%). Total arch replacement was performed in 31 patients (25%). Direct cannulation of the ascending aorta is an easy and safe method in patients with AADA. This technique, which also avoids retrograde flow in the downstream aorta, is an alternative to time-consuming axillary artery access.

Antegrade Versus Retrograde Cerebral Perfusion in Relation to Postoperative Complications Following Aortic Arch Surgery for Acute Aortic Dissection Type A

Aortic arch surgery is impossible without the temporary interruption of brain perfusion and therefore is associated with high incidence of neurologic injury. The deep hypothermic circulatory arrest (HCA), in combination with antegrade or retrograde cerebral perfusion (RCP), is a well-established method of brain protection in aortic arch surgery. In this retrospective study, we compare the two methods of brain perfusion. From 1998 to 2006, 48 consecutive patients were urgently operated for acute type A aortic dissection and underwent arch replacement under deep hypothermic circulatory arrest (DHCA). All distal anastomoses were performed with open aorta, and the arch was replaced totally in 15 cases and partially in the remaining 33 cases. Our patient cohort is divided into those protected with antegrade cerebral perfusion (ACP) (group A, n = 23) and those protected with RCP (group B, n = 25). No significant difference was found between groups A and B with respect to cardiopulmonary bypass-time, brain-ischemia time, cerebral-perfusion time, permanent neurologic dysfunction, and mortality. The incidence of temporary neurologic dysfunction was 16.0% for group A and 43.50% for group B (p = 0.04). The mean extubation time was 3.39 +/- 1.40 days for group A and 4.96 +/- 1.83 days for group B (p = 0.0018). The mean ICU-stay was 4.4 +/- 2.3 days for group A and 6.9 +/- 2.84 days for group B (p = 0.0017). The hospital-stay was 14.38 +/- 4.06 days for group A and 19.65 +/- 6.91 days for group B (p = 0.0026). The antegrade perfusion seems to be related with significantly lower incidence of temporary neurological complications, earlier extubation, shorter ICU-stay, and hospitalization, and hence lower total cost.

Hypothermic circulatory arrest with selective antegrade cerebral perfusion in ascending aortic and aortic arch surgery: A risk factor analysis for adverse outcome in 501 patients

This study was undertaken to identify preoperative and intraoperative risk factors influencing outcome after operations requiring hypothermic circulatory arrest with selective antegrade cerebral perfusion in a single center. Between November 1999 and March 2006, a total of 501 consecutive patients (median age 64 years, range 20-86 years, 320 male) underwent aortic arch surgery with moderate hypothermic circulatory arrest (25 degrees C +/- 2 degrees C) and additional selective antegrade cerebral perfusion (14 degrees C) at our institution for various indications (256 aneurysms, 153 acute and 23 chronic type A aortic dissections, 66 other). Of these, 181 were emergency operations. Statistical analysis was carried out to determine risk factors for 30-day mortality as well as for temporary and permanent neurologic dysfunction. Overall mortality was 11.6%. Permanent neurologic dysfunction occurred in 48 patients (9.6%); temporary neurologic dysfunction was detected in 67 patients (13.4%). Multivariate analysis revealed age (P = .001, odds ratio 1.08), reoperation (P = .006, odds ratio 3.58), femoral arterial cannulation (P = .004, odds ratio 2.87), and cardiopulmonary bypass duration (P < .001, odds ratio 1.009) as risk factors for mortality. Permanent neurologic dysfunction was associated with preoperative renal insufficiency (P = .029, odds ratio 2.79) and operation time (P < .001, odds ratio 1.005), whereas temporary neurologic dysfunction occurred in patients with coronary artery disease (P = .04, odds ratio 2.29), emergency surgery (P = .001, odds ratio 4.09), and increasing hypothermic circulatory arrest duration (P = .01, odds ratio 1.015). Moderate hypothermic circulatory arrest in combination with cold selective antegrade cerebral perfusion is an adequate tool for neuroprotection during aortic surgery. Nevertheless, the safety of this technique is limited for patients with long intraoperative durations, advanced age, and multiple comorbidities. This technique, which avoids profound core temperatures, has become an alternative to simple deep hypothermic circulatory arrest.

Temporary neurological dysfunction after surgery of the thoracic aorta: a predictor of poor outcome and impaired quality of life☆

Transient neurological dysfunction (TND) consists of postoperative confusion, delirium and agitation. It is underestimated after surgery on the thoracic aorta and its influence on long-term quality of life (QoL) has not yet been studied. This study aimed to assess the influence of TND on short- and long-term outcome following surgery of the ascending aorta and proximal arch. Nine hundred and seven patients undergoing surgery of the ascending aorta and the proximal aortic arch at our institution were included. Two hundred and ninety patients (31.9%) underwent surgery because of acute aortic dissection type A (AADA) and 617 patients because of aortic aneurysm. In 547 patients (60.3%) the distal anastomosis was performed using deep hypothermic circulatory arrest (DHCA). TND was defined as a Glasgow coma scale (GCS) value <13. All surviving patients had a clinical follow up and QoL was assessed with an SF-36 questionnaire. Overall in-hospital mortality was 8.3%. TND occurred in 89 patients (9.8%). As compared to patients without TND, those who suffered from TND were older (66.4 vs 59.9 years, p<0.01) underwent more frequently emergent procedures (53% vs 32%, p<0.05) and surgery under DHCA (84.3% vs 57.7%, p<0.05). However, duration of DHCA and extent of surgery did not influence the incidence of TND. In-hospital mortality in the group of patients with TND compared to the group without TND was similar (12.0% vs 11.4%; p=ns). Patients with TND suffered more frequently from coronary artery disease (28% vs 20.8%, p=ns) and were more frequently admitted in a compromised haemodynamic condition (23.6% vs 9.9%, p<0.05). Postoperative course revealed more pulmonary complications such as prolonged mechanical ventilation. Additional to their transient neurological dysfunction, significantly more patients had strokes with permanent neurological loss of function (14.6% vs 4.8%, p<0.05) compared to the patients without TND. ICU and hospital stay were significantly prolonged in TND patients (18+/-13 days vs 12+/-7 days, p<0.05). Over a mean follow-up interval of 27+/-14 months, patients with TND showed a significantly impaired QoL. The neurological outcome following surgery of the ascending aorta and proximal aortic arch is of paramount importance. The impact of TND on short- and long-term outcome is underestimated and negatively affects the short- and long-term outcome.

Is Treatment of Acute Type A Aortic Dissection in Septuagenarians Justifiable?

This study was undertaken to analyze the risk of mortality and neurological complications after treatment of acute type A aortic dissection in septuagenarians. From 1996 through 2002, 24 patients > 70 years underwent surgery for acute type A aortic dissection. Their median age was 75 years (range, 71-82 years), and 15 were male. Eleven (46%) had previous neurological events, 22% presented with hemodynamic instability and aortic rupture was found in 7%. Ten had hypothermic circulatory arrest alone, 3 had it in combination with retrograde cerebral perfusion and 11 had selective antegrade cerebral perfusion as an adjunct. The overall survival rate was 71% (17/24). Temporary neurological dysfunction was found in 3 (12.5%), and permanent neurological dysfunction in 9 (37.5%), leading to death in 3. Comparison of mortality rates and neurological outcome showed a marked tendency towards better outcome in patients who had hypothermic circulatory arrest and selective antegrade cerebral perfusion. Surgery for aortic dissections in the elderly can be performed with acceptable mortality, but there is a high rate of neurological complications. Despite the small number of patients, selective antegrade cerebral perfusion seemed to reduce the incidence of neurological events.

Metabolic relevance during isolation technique in total arch repair for patients at high risk with embolic stroke

In patients undergoing total arch replacement with protruding or mobile atheroma in the proximal aorta, we isolate cerebral circulation from systemic one by starting selective cerebral perfusion (SCP) before systemic arterial perfusion to prevent aortogenic embolic stroke. We disclose the safety of this isolation technique by measuring cerebral oxygenation and metabolism. Sixty-six patients underwent total arch replacement using SCP since 1998. The isolation technique was applied in sixteen patients. Jugular venous oxygen saturation (SjO(2)) was monitored in nine patients undergoing isolation technique (isolation-group) and in thirteen patients of the rest (conventional-group). Oxygen, glucose, and lactate extraction ratio (OER, GER, and LER) were measured at seven time points peri-operatively. The isolation-group had significantly longer SCP time (isolation: 185+/-52 min vs. conventional: 140+/-43 min, P<0.01). During cooling, SjO(2) was kept comparable between groups. OER was minimum at the end of cooling and comparable between groups (isolation: 3.8+/-7.7% vs. conventional: 11.7+/-13.8%, P=0.37). There were no significant differences in GER and LER between groups. There were neither in-hospital death nor stroke. Temporary neurological dysfunction was observed only in conventional-group (n=3, 23%, P=0.12). Isolation technique for total arch replacement could be performed safely and may provide acceptable results in patients at high risk for embolic stroke.

Determinants of Early Mortality and Neurological Morbidity in Aortic Operations Performed Under Circulatory Arrest

Aneurysms and dissections of the thoracic aorta continue to present a surgical challenge and their incidence is increasing in recent years. The mortality rate of surgical treatment is still higher than those of other cardiovascular operations. Neurological injury is the most feared complication resulting from repair of these lesions. This study aims to determine the factors that influence the neurological outcome and mortality after thoracic aortic operations. During the period from November 1993 through May 1999, 144 patients were operated on for conditions involving the ascending aorta and/or aortic arch. Ninety-five (66.0%) were operated for aortic dissection and 49 (34.0%) were for aortic aneurysms. Sixty-two patients (43.1%) had replacement of ascending aorta with distal open technique; 82 patients (56.9%) had hemiarch or total arch replacement or repair of the distal arch. Twenty-seven (18.7%) early deaths occurred. New stroke occurred in two patients (1.4%) and temporary neurological dysfunction in nine patients (6.3%). Deep hypothermic circulatory arrest with retrograde cerebral perfusion was used in all patients. On multivariate logistic regression analysis, risk factors for mortality were chronic renal failure, preoperative organ malperfusion, rupture, total circulatory arrest time > 60 minutes, postoperative acute renal failure, postoperative low cardiac output, sepsis, and multiple organ failure. Risk factors for neurological morbidity were preoperative chronic renal failure, preoperative hemodynamic instability, postoperative low cardiac output, and pulmonary complications. Hypothermic circulatory arrest with retrograde cerebral perfusion was not an independent predictor of neurological morbidity on multivariate analysis, even if the arrest period was more than 60 minutes. Lengths of circulatory arrest periods and clinical presentations of the patients are important determinants of mortality.

Cognitive brain function after hypothermic circulatory arrest assessed by cognitive P300 evoked potentials

The role of hypothermic circulatory arrest (HCA) in cardiovascular surgery is controversial and assumed to result in neurocognitive dysfunction that is not always detected by standard clinical observation. We assessed cognitive P300 visual evoked potentials (P300) in patients undergoing either HCA or coronary artery bypass grafting (CABG) to elucidate whether HCA was associated with postoperative cognitive decline. Thirteen patients undergoing either aortic arch replacement (n=4) or pulmonary thromboendarterectomy (n=9) using HCA (mean: 28+/-11 min, 22+/-2 degrees C) were studied. They were compared to 13 patients undergoing on-pump CABG. P300s were measured 1 day before and 1 week after the operation. We assessed an area under the curve (AUC) between 280 and 600 ms and center of this area [Ct (time), Cv (voltage)]. The ratio of these parameters acquired by target (TG) and non-target (NTG) stimulus (TG/NTG) was calculated to assess concentration on TG stimulus and defined as concentration index (CI: CI(AUC), CI(Ct), and CI(Cv)). There was no significant difference in preoperative characteristics between groups. There were neither strokes nor hospital deaths. Preoperatively, the HCA group could not concentrate on target stimulus as well as the control group in frontal leads (CI(AUC) and CI(Cv) were lower in HCA group than in control group). However, the HCA group could concentrate on target stimulus better than the control group postoperatively because postoperative CI(AUC) (pre-operation: 1.1+/-0.5 to post-operation: 1.7+/-0.4, P=.02) and CI(Cv) (1.1+/-0.4 to 1.6+/-0.4, P=.01) were significantly improved in the HCA group, whereas these were significantly impaired in the control group (CI(AUC): 1.6+/-0.6 to 1.3+/-0.4, P=.03, CI(Cv): 1.5+/-0.5 to 1.2+/-0.3, P<.01). Postoperative CI(Ct) in the HCA group were significantly impaired in all leads. The duration of HCA did not correlate with any values of postoperative P300. No specific trends were observed in either preoperative or postoperative P300 values between patients with or without postoperative temporary neurological dysfunction (one in each group). Postoperative improvement of CI(AUC) and CI(Cv) in Fz lead were found in 85 and 69% in the HCA group and 23 and 23% in the control group, respectively (CI(AUC): P<.01, CI(Cv): P<.05). P300 detected no significant neurocognitive impairment due to the relatively brief period of HCA (approximately 28 min).

Impact of different brain protection techniques upon postoperative temporary neurological dysfunction in aortic surgery with the aid of deep hypothermic circulatory arrest

To assess impact of different brain protection techniques upon postoperative temporary neurological dysfunction in aortic surgery with the aid of deep hypothermic circulatory arrest. From January 2003 to December 2005, 78 patients who met the inclusion criteria entered the present cohort, 43 of whom were under the aid of deep hypothermic circulatory arrest plus retrograde cerebral perfusion (RCP group) and the other 35 under deep hypothermic circulatory arrest plus selective antegrade cerebral perfusion (SCP group). The present and grades of postoperative temporary neurological dysfunction were assessed by independent observers with the same criterion. The impact of duration of deep hypothermic circulatory arrest upon the postoperative temporary neurological dysfunction was also evaluated. The incidence of postoperative temporary neurological dysfunction was significantly higher in the RCP group than in the SCP group (15, 34.9% vs. 4, 11.4%, P<0.05). And long duration of deep hypothermic circulatory arrest (more than 50 min) has a negative impact on the postoperative temporary neurological dysfunction rate. Applying selective antegrade cerebral perfusion as the brain protection technique and shortening the duration of deep hypothermic circulatory arrest can reduce the incidence of temporary neurological dysfunction and preserve cerebral function more effectively.

Aortic Arch Replacement With a Trifurcated Graft

The purpose of this study was to review the results of aortic arch replacement using a trifurcated arch graft in conjunction with hypothermic circulatory arrest (HCA) and selective antegrade cerebral perfusion (SCP). One hundred fifty consecutive patients (91 male; mean age, 63 +/- 14 years; range, 20 to 87) had aortic arch replacement using a trifurcated arch graft and HCA/SCP from September 1999 to December 2005. The axillary artery was used for cannulation; a trifurcated graft was sewn to the arch vessels during a short interval of HCA; SCP was utilized through the trifurcation graft during the proximal and distal arch repair, and then the trifurcation graft was sewn to the arch graft. Fifty-five patients had chronic dissection; 48 had atherosclerotic and 29 had degenerative aneurysms; 74 had undergone previous cardiac surgery. Isolated arch reconstruction was undertaken in 38 patients: concomitant procedures included ascending aortic replacement in 74; ascending aorta and root replacement in 21; descending replacement in 4, and coronary artery bypass grafting in 36. An elephant trunk was used in 144, but distal to the left subclavian artery in only 87; in 34, it was distal to the left carotid, in 9, it was between the brachiocephalic and left carotid, and in 18, it was proximal to all arch branches. Mean HCA duration was 31.1 +/- 6.5 minutes; SCP lasted 66.6 +/- 21.0 minutes, at a mean temperature of 15.8 +/- 2.1 degrees C. Adverse outcome occurred in 13 of 150 patients (8.7%): there were 7 hospital deaths and 6 permanent strokes. Temporary neurologic dysfunction was seen in only 7 patients, and renal failure was transient in 9 patients requiring dialysis. The use of a trifurcated arch graft with HCA and SCP is a safe and versatile technique for repair of arch aneurysms.

Integrated Total Arch Replacement Using Selective Cerebral Perfusion: A 6-Year Experience

The purpose of this study was to evaluate the recent outcome of integrated total arch replacement using antegrade selective cerebral perfusion with right axillary artery perfusion. Between 2000 and 2005, 305 patients underwent elective total arch replacement for arch or distal arch aneurysm using a Dacron (DuPont, Wilmington, DE) quadrifurcated prosthesis through a median sternotomy. There were 34 dissecting and 271 nondissecting aneurysms. Brain protection was standardized using antegrade selective cerebral perfusion with right axillary artery cannulation at 20 degrees to 28 degrees C. Risk factors for early mortality and neurologic complications were investigated using multivariate logistic regression analyses. The durations of hypothermic circulatory arrest, myocardial ischemia, selective cerebral perfusion, cardiopulmonary bypass, and surgery were 60.9 +/- 16.8, 125.2 +/- 39.3, 150.1 +/- 39.0, 229.8 +/- 91.4, and 466.4 +/- 175.8 minutes, respectively. Seven patients died, for a 2.3% early mortality. Permanent neurologic dysfunction developed in 5 patients (1.6%), and temporary neurologic dysfunction in 20 (6.6%). The mid-term survival rate was 94.6% +/- 1.5% at 3 years. On multivariate analyses, prolonged surgery was a risk factor for early mortality. Preoperative cerebral hypoperfusion was a significant determinant for temporary neurologic dysfunction and male gender for permanent neurologic dysfunction. Integrated total arch replacement using antegrade selective cerebral perfusion with right axillary artery cannulation yields a favorable outcome with low mortality and cerebral morbidity rates.

Aortic Arch Replacement Using Selective Cerebral Perfusion

The present study was conducted to report our clinical experience with aortic arch replacement using selective cerebral perfusion (SCP) and determine the independent predictors of in-hospital mortality and neurologic outcome. We studied 472 consecutive patients who underwent aortic arch replacement using SCP between January 1986 and February 2006. All operations were performed with the aid of hypothermic extracorporeal circulation, SCP, and in most cases, systemic circulatory arrest for open distal anastomosis. The etiology of aortic diseases included acute aortic dissection in 126 patients (27%), chronic aortic dissection in 102 (21%), and degenerative aneurysm in 245 (52%). Total arch replacement was performed in 420 patients (89%). Mean SCP time was 88 +/- 32 minutes. The overall in-hospital mortality was 9.3%, but it dropped significantly to 4.1% in the most recent 266 patients. Independent predictors of in-hospital mortality were early series, renal/mesenteric ischemia, pump time, increasing age, chronic renal dysfunction, history of cerebrovascular accident (CVA), and previous ascending or arch operation. Overall postoperative temporary and permanent neurologic dysfunction were 4.7% and 3.2%, respectively. A history of CVA was the only predictor of temporary neurologic dysfunction, whereas CVA and pump time were independent predictors of permanent neurologic dysfunction. SCP time had no significant correlation with in-hospital mortality and neurologic outcome. SCP facilitates complicated aortic arch replacement, resulting in a reduction of mortality and morbidity for arch aneurysms or dissections.

Antegrade selective cerebral perfusion in thoracic aorta surgery: safety of moderate hypothermia

Although antegrade selective cerebral perfusion (ASCP) has been demonstrated to be the best method of protection of brain ischemia during aortic arch surgery, there is no consensus regarding optimal temperature during ASCP. The study analyzed the outcomes of aortic surgery using ASCP at different degree of systemic hypothermia. Between November 1996 and November 2005, 305 patients underwent thoracic aorta surgery using ASCP. Patients were divided into two groups according to the lowest systemic temperature: moderate systemic hypothermia (> or =25 degrees C) was used in 189 patients (group A), and a deeper hypothermia (<25 degrees C) in 116 patients (group B). One hundred and five patients suffered from acute type A aortic dissection. The extension of aortic replacement was significantly larger in group A, while the average ASCP time was not different between groups (63+/-37.7min group A, 58.6+/-35.6min group B; p=0.314). The 30-day mortality rate was 12.7% in group A and 13.8% in group B (p=0.862). Permanent neurologic deficits occurred in eight patients (2.6%) without significant differences between groups (3.1% group A vs 1.7% group B; p=0.715). Twenty-five patients (8.2%) suffered from temporary neurologic dysfunction (7.9% group A vs 8.6% group B; p=0.833). In our experience, ASCP was a safe technique for thoracic aorta surgery allowing complex aortic repairs to be performed with good results in terms of hospital mortality and neurologic outcomes. The fact that there was no difference between the two groups suggests that moderate systemic hypothermia (26 degrees C) appears to be a safe and sufficient tool for brain protection. Moreover, the well known hypothermia-related side effects may be avoided.

Axillary Cannulation for Proximal Aortic Surgery is as Safe in the Emergent Setting as in Elective Cases

Right axillary artery cannulation and selective antegrade cerebral perfusion (SCP) have become well-described strategies in the surgical treatment of proximal aortic disease. Many series report increases in adverse outcomes with SCP used in emergent settings. We compare outcomes in elective and emergent patients. Over 21 months, SCP through right axillary cannulation with a side graft was performed in 61 patients. Thirty-three percent (20 of 61) underwent emergent operation for Stanford type A dissection or intramural hematoma, including 3 of 20 (4.7%) with pericardial tamponade; the remainder of SCP (41 of 61) was elective. The mean follow-up was 9.1 +/- 0.40 months. Selective antegrade cerebral perfusion was used in 20 of 22 emergent cases (91%), with 2 unsuccessful cannulation attempts, and no peripheral arterial dissections encountered. The SCP flows averaged 16.3 +/- 0.71 cc x kg(-1) x min(-1) for a mean perfusion period of 26.1 +/- 1.9 minutes. The average cardiopulmonary bypass time for all patients was 173 +/- 11 minutes. Average hospital stay was 8.1 +/- 0.80 days. One case (1.3%) of permanent and 3 cases (4.8%) of temporary neurologic dysfunction occurred in SCP patients. The hospital mortality rate for emergent SCP cases (2 of 20, 10%) was not statistically different from the mortality rate for elective SCP cases (3 of 41, 7.3%, p = not significant), with no difference in complication rates. All 3 SCP patients with preoperative tamponade survived without complication. Cerebral oximetry data showed a trend toward decreased left-sided (contralateral) scalp perfusion. There was no association of emergent status with neurologic dysfunction, death, or any other adverse outcome. Axillary cannulation and SCP in the surgical treatment of proximal aortic pathology is safe in both elective and emergent settings.

Short Moderate Hypothermic Circulatory Arrest without Any Adjunctive Cerebral Protection for Surgical Repair of the Ascending Aorta Extending into the Proximal Aortic Arch: Is It Safe?

We have been using only moderate hypothermic circulatory arrest (HCA) for patients with ascending aortic aneurysms extending into the proximal aortic arch if the distal anastomoses seem to be simple and easy. The aim of this study is to evaluate the early and midterm results of the use of moderate HCA without any adjunctive cerebral protection in such patients. Between October 2000 and March 2005, 23 patients with an age range of 39 to 77 years (mean, 59.7 +/- 12.2 years) received surgical repair of the ascending aorta extending into the proximal aortic arch using HCA without any adjunctive cerebral protection. Mean circulatory arrest time was 7.5 +/- 2.0 minutes (range, 2-13 minutes), and mean core temperature at induction of the circulatory arrest was 26.7 +/- 1.4 degrees C (range, 24-30 degrees C). Operative mortality was 4.3% (1/23) due to unknown cause after successful extubation. Temporary neurological dysfunction was observed in only 1 patient (4.3%), and no persistent neurologic event was observed in any of the patients. One patient died 3 months after the operation due to a mediastinitis. No other cardiac or neurologic event was observed in the 21 surviving patients. Our results suggest that moderate HCA at 26 degrees C to 28 degrees C without any adjunctive cerebral protection within 10 minutes is safe in selected patients.

Pulmonary endarterectomy for chronic thromboembolic pulmonary hypertension: is deep hypothermia required?☆

To investigate whether deep (<20 degrees C) hypothermia is necessary in patients undergoing pulmonary endarterectomy for chronic thromboembolic pulmonary hypertension. Between January 2004 and February 2005, 30 patients (New York Heart Association (NYHA) class III or IV) were randomly assigned to increasing (1 degrees C) levels of moderate (28-32 degrees C) hypothermic cardiopulmonary bypass (CPB), each study group including six patients. Primary study endpoint was adverse neurological outcome. Overall preoperative total pulmonary vascular resistance was 1110+/-192 dynes cm(-5). Mean CPB and cross-clamp times, and core temperature at the time of circulatory arrests were 129+/-39 min and 92+/-24 min, and 30.1+/-1.5 degrees C, respectively. Circulatory arrest was induced 2+/-0.7 times and its mean total duration was 10.3+/-5.2 min (range, 2-19 min). Postoperatively, three patients (10%) belonging to the 31 degrees C (n=1) and 32 degrees C (n=2) groups suffered from temporary neurological dysfunction. Postoperative mechanical ventilatory support and ICU stay were 26.3+/-18.9 h and 6.6+/-8.5 days, respectively, and uninfluenced by degree of hypothermia. There were no lung reperfusion injuries or any other major complications. All patients had a significant hemodynamic improvement. Results suggest that pulmonary endarterectomy can be safely performed with moderate hypothermia and short periods of circulatory arrests without the need of profound hypothermia.

Hypothermic circulatory arrest is not a risk factor for neurologic morbidity in aortic surgery: A propensity score analysis

Hypothermic circulatory arrest has been an important tool in aortic arch surgery, even though its use has recently been discussed controversially. We sought to clarify the role of hypothermic circulatory arrest as a risk factor for mortality and neurologic morbidity in aortic surgery by using a propensity score-matching analysis. Five hundred eleven patients (60 +/- 13 years, 349 male patients) who underwent replacement of the ascending aorta with (n = 273) or without (n = 238) arch involvement were analyzed by means of multivariate analysis. Using propensity score matching, we identified comparable patient groups: HCA(+) group and HCA(-) group (n = 110 each). For aortic arch replacement, hypothermic circulatory arrest was used with a mean duration of 14 +/- 9 minutes: 12 +/- 7 minutes or 26 +/- 8 minutes for partial or total arch replacement, respectively. In the entire cohort multivariate analysis identified acute dissection and duration of cardiopulmonary bypass as significant predictors for hospital death. Predictors for stroke were acute dissection, diabetes mellitus, peripheral arterial disease, and concomitant mitral valve surgery, and predictors for temporary neurologic dysfunction were peripheral arterial disease and age. After propensity score matching, the incidence of death (HCA[+]: 0.9% vs HCA[-]: 2.7%), stroke (0% vs 1.8%, respectively), and temporary neurologic dysfunction (15.5% vs 13.6%, respectively) was comparable between the 2 groups. Multivariate analysis identified age, diabetes mellitus, peripheral arterial disease, and concomitant coronary artery bypass grafting as the independent risk factors for temporary neurologic dysfunction. In a standard clinical setting (hypothermic circulatory arrest of <30 minutes and nasopharyngeal temperature of <20 degrees C), hypothermic circulatory arrest constitutes no significant risk for mortality or neurologic morbidity and thus appears clinically safe. Patient-related risk factors primarily determine clinical outcome.