Hypothermic circulatory arrest in octogenarians: risk of stroke and mortality

The Postoperative Care of Adult Patients Exposed to Deep Hypothermic Circulatory Arrest

Deep hypothermic circulatory arrest with cardiopulmonary bypass is indicated for complex surgical operations in adult patients involving the aortic arch, thoracoabdominal aorta, cerebral vasculature, and tumors extending into the vena cava and heart. Understanding the principles of ischemic-reperfusion injury and the effects of hypothermia in attenuating this process is fundamental to the delivery of effective postoperative care. Neurologic injury is the most troublesome adverse effect after the use of deep hypothermic circulatory arrest and cardiopulmonary bypass, presenting as either a transient neurologic deficit (5.9% to 28.1%) or an irreversible neurologic injury (1.8% to 13.6%). In patients with neurological injury, early postoperative mortality is markedly increased (18.2%), and for those patients that survive, long-term cognitive disability is still evident 6 months later. Early postoperative support of organ function, along with timely diagnosis and treatment of organ injury, is essential in minimizing perioperative morbidity, particularly neurologic morbidity. Meticulous management of fluids, maintaining stable cardiovascular hemodynamics with particular attention to systolic blood pressure, optimizing oxygen delivery, limiting ventilatorassociated lung injury, intensive insulin therapy for control of blood glucose levels, and avoidance of hyperthermia are essential in limiting organ injury and reducing perioperative morbidity and mortality.

Serum UCH-L1 as a Novel Biomarker to Predict Neuronal Apoptosis Following Deep Hypothermic Circulatory Arrest

BACKGROUND

Deep hypothermic circulatory arrest (DHCA) has been used in cardiac surgery involving infant complex congenital heart disease and aortic dissection. DHCA carries a risk of neuronal apoptotic death in brain. Serum ubiquitin C-terminal hydrolase L1 (UCH-L1) level is elevated in a number of neurological diseases involving neuron injury and death. We studied the hypothesis that UCH-L1 may be a potential biomarker for DHCA-induced ischemic neuronal apoptosis.

METHODS

Anesthetized piglets were used to perform cardiopulmonary bypass (CPB). DHCA was induced for 1 hour followed by CPB rewarming. Blood samples were collected and serum UCH-L1 levels were measured. Neuron apoptosis and Bax and Bcl-2 proteins in hippocampus were examined. The relationship between neuron apoptosis and UCH-L1 level was determined by receiver operating characteristics (ROC) curves and correlation analysis.

RESULTS

DHCA resulted in marked neuronal apoptosis, significant increase in Bax:Bcl-2 ratio in hippocampus and UCH-L1 level elevations in serum (all P<0.05). Positive correlation was obtained between serum UCH-L1 level and the severity of neuron apoptosis (r= 0.78, P<0.01). By ROC, the area under the curve were 0.88 (95% CI: 0.74-0.99; P<0.01), 0.81 (95% CI: 0.81-0.96; P<0.05), 0.71 (95% CI: 0.47-0.92; P=0.11) for UCH-L1, Bax/Bcl-2 ratio and Bax, respectively. Using a cut-off point of 0.25, the UCH-L1 predicted neuronal apoptosis with a sensitivity of 85% and specificity of 57%.

CONCLUSION

Serum UCH-L1, as an easy and quick measurable biomarker, can predict neural apoptosis induced by DHCA. The elevation in UCH-L1 concentration is consistent with the severity of neural apoptosis following DHCA.

Thoracic aortic aneurysms in octogenarians: the results of open surgical repair using hypothermic circulatory arrest with antegrade selective cerebral perfusion

OBJECTIVE

Although recent progress has expanded the indications for thoracic aortic surgery to include elderly patients, the procedure remains extremely invasive. We performed a chart review to determine the early and late outcomes of thoracic aortic surgery using hypothermic circulatory arrest (HCA) and antegrade selective cerebral perfusion (ASCP) in octogenarians.

MATERIALS AND METHODS

Of 79 patients who underwent surgery for thoracic aortic aneurysms from April 2007 through December 2012, 8 patients 80 years or older were selected for analysis. Mean age at the time of surgery was 84.3±1.39 years. The diagnoses were aortic dissection in 5 patients and degenerative thoracic aneurysm in 3 patients. All patients underwent surgery with HCA. The lowest body temperature was 25℃ ASCP was used as an additional brain-protection technique. Emergency operations were performed in 5 patients (62.5%).

RESULTS

The mean duration of HCA was 60.4±19.7 minutes, that of aortic cross-clamping time was 143.0±30.4 minutes, and mean pump time was 207.8±44.4 minutes. The hospital mortality rate was 0%. Major postoperative complications occurred in 3 (37.5%) patients: stroke, temporary neurologic dysfunction, and paraparesis in 1 patient each. No patients required temporary dialysis for new-onset renal dysfunction. There were no deaths during the 65-month follow-up period.

CONCLUSION

The early and late outcomes after thoracic aortic surgery at our hospital using HCA with ASCP in octogenarians are acceptable. The operations are performed with an acceptable operative risk, even under emergency situations, including acute aortic dissection.

Elective hypothermic circulatory arrest to address aortic pathology is safe for the elderly

BACKGROUND

Due to assumptions of excessive risk, hypothermic circulatory arrest (HCA) has been considered prohibitive in elderly patients. However, as more elderly patients are referred for assessment of difficult aortic valve, ascending aorta, and aortic arch pathology, the risk of HCA in these patients needs to be addressed. We hypothesized that the use of HCA would not increase mortality or complications in elderly patients compared to younger counterparts.

METHODS

We retrospectively reviewed the charts of adult patients who underwent elective HCA between January 1995 and June 2007. Of 147 procedures, 45 patients were >or=75 years old. These patients were compared to their younger counterparts in terms of comorbidities, operations, and complications.

RESULTS

Comparing patients >or=75 years old to their younger counterparts revealed no significant differences in outcomes including nearly identical rates of confusion (>or=75 15% vs <75 9%, p > 0.5) and stroke (>or=75 11% vs <75 7%, p > 0.2). There was also no difference in 30-day mortality (>or=75 7% vs <75 7%, p = 0.9). Lengths of hospital stays and intensive care unit stays were longer in the older patients, but this was not statistically significant.

CONCLUSION

In this study, elderly patients faired well with HCA compared to younger patients. These data suggest that the use of HCA is safe in selected elderly patients. Elderly patients should be considered for indicated procedures of the aortic valve, ascending aorta, and aortic arch regardless of age.

Aortic surgery requiring hypothermic circulatory arrest in octogenarians

BACKGROUND

Recent improvements in the outcomes of cardiovascular operation in octogenarians have resulted in an increase in the number of referrals of elderly patients for aortic surgery requiring hypothermic circulatory arrest.

METHODS

This was a retrospective chart review.

RESULTS

Between 2000 and 2007, 12 octogenarians with aortic aneurysms underwent surgery requiring hypothermic circulatory arrest. There were seven men with a median age of 83 years (range, 80-87 years). Diagnoses of aortic disease included acute type A aortic dissection in seven patients and degenerative thoracic aneurysm in five. Operation was performed through median sternotomy in eight patients and posterolateral thoracotomy in four. The median duration of hypothermic circulatory arrest was 50 minutes (range, 15-84 minutes). Method of brain protection during hypothermia was selective antegrade cerebral perfusion in five patients, retrograde cerebral perfusion in two, and arrest alone in five. The hospital mortality rate was 8%. Major postoperative complications occurred in six (50%) patients, with transient neurologic dysfunction in two patients and no stroke.

CONCLUSION

Although postoperative complications were common, the clinical outcome of aortic surgery requiring hypothermic circulatory arrest was acceptable.

Risk factors of mortality and permanent neurologic injury in patients undergoing ascending aortic and arch repair

OBJECTIVES

To analyze outcome in elderly patients after surgical repair of the ascending aorta and the aortic arch as compared with their younger counterparts and to determine risk factors of mortality and permanent neurologic injury. Patients and methods Between January 1995 and February 2003, a total of 369 patients underwent ascending aortic and arch repair. Indications for surgical intervention were acute type A dissections in 174 (47%) patients (<75 years, n = 147; > or =75 years, n = 27) and chronic atherosclerotic aneurysms in 195 (53%) patients (<75 years, n = 168; > or =75 years, n = 27). Emergency surgery was performed in 167 (45%) patients; 202 patients (54.7%) underwent surgery requiring deep hypothermic circulatory arrest. Pre- and intraoperative factors were evaluated by means of stepwise logistic regression analysis to determine risk factors of mortality and permanent neurologic injury.

RESULTS

Overall in-hospital mortality was 11.6%. In-hospital mortality with regard to indication for surgical intervention was comparable in both age groups (type A dissection: <75 years, 15.6%; > or =75 years, 18.5%; P =.731; chronic atherosclerotic aneurysm: <75 years, 7.7%; > or =75 years, 7.4%; P =.933). Permanent neurologic injury was observed in 5.0%. Permanent neurologic injury with regard to surgical intervention was comparable in both age groups (type A dissection: <75 years, 8.8%; > or =75 years, 3.7%; P =.359; chronic atherosclerotic aneurysm: <75 years, 3.0%; > or =75 years, 3.7%; P =.843). Stepwise logistic regression analysis revealed preoperative hemodynamic instability (odds ratio 4.3; P =.000), duration of cardiopulmonary bypass (odds ratio 2.1; P =.001), and permanent neurologic injury (odds ratio 1.7; P =.033) but not age as independent predictors affecting mortality. Utilization of but not duration of deep hypothermic circulatory arrest was the only independent predictor of permanent neurologic injury (odds ratio 2.8; P =.019).

CONCLUSIONS

Age shows a trend toward a higher risk of mortality but does not predict a higher incidence of permanent neurologic injury after ascending aortic and arch repair. As utilization of deep hypothermic circulatory arrest remains the only independent predictor of permanent neurologic injury, alternative approaches to maintain cerebral perfusion during ascending aortic and arch repair are warranted.

Aortic atherosclerosis and postoperative neurological dysfunction in elderly coronary surgical patients

BACKGROUND

Arteriosclerosis of the ascending aorta is an important risk factor for cerebral embolism. However, the association between arteriosclerosis of the ascending aorta and neurologic dysfunction after coronary artery surgery has not been evaluated prospectively.

METHODS

We examined whether varying degrees of arteriosclerosis in the ascending aorta, assessed by epiaortic ultrasonography, increased the incidence of neuropsychologic dysfunction and stroke in 463 elderly patients (> or = 60 years old) after coronary artery surgery.

RESULTS

Patients with severe arteriosclerosis (n = 76) had higher rates of postoperative neuropsychologic dysfunction (26%) and intraoperative stroke (10.5%); the moderately atherosclerotic patients (n = 57) had rates of 7% and 1.8%, respectively; whereas control patients (almost normal or mild arteriosclerosis, n = 330) had rates of 8% and 1.2%, respectively (all p < 0.001). Univariate analysis indicated that multiple small infarctions or broad infarctions, cerebral arterial stenosis, circulatory arrest, maximal thickness of intima around the site of aortic manipulation, and deformities due to clamp or cannulation were associated significantly with intraoperative strokes in patients with severe arteriosclerosis.

CONCLUSIONS

Severe arteriosclerosis of the ascending aorta significantly increased the risk of postoperative neuropsychologic dysfunction and stroke after coronary artery bypass grafting. If a thick plaque is noted near the manipulation site, a nontouch method of the ascending aorta should be applied to reduce the incidence of neurologic dysfunction.

Is aortic surgery using hypothermic circulatory arrest in octogenarians justifiable?

OBJECTIVE

This study was undertaken to analyze the risk of mortality and neurological complications after aortic surgery requiring hypothermic circulatory arrest (HCA) in octogenarians.

METHODS

All patients of >80 years at the time of aortic surgery requiring HCA since 1988 were examined. Of 51 patients, 23 were male; the median age was 83. Twenty-six (51%) had proximal repair; the arch was replaced in eight (16%), and 17 (33%) had descending aorta repair. Eleven (22%) were emergencies. Multivariate analysis was carried out to determine the risk factors for in-hospital mortality and/or stroke (adverse outcome) using variables with P<0.1 after univariate analysis.

RESULTS

The hospital mortality was 16%. Five patients suffered strokes (9.8%): only one survived >6 months, and three died before discharge. The overall adverse outcome was 22%, but elective operation was associated with much better results, with an adverse outcome of only 3.6% after operations via a median sternotomy. Adverse outcome was strikingly higher with more distal resections via a left thoracotomy: 47 vs. 8.8% for ascending aorta/arch resections (P=0.003). Emergency operation via a lateral thoracotomy was associated with a prohibitively high adverse outcome. Twenty-nine patients (73%) had temporary neurological dysfunction (TND). Multivariate analysis revealed emergency operation (P=0.01; odds ratio (OR), 10.6) and operations via a lateral thoracotomy (P=0.008; OR, 11) as independent preoperative predictors of adverse outcome. The overall survival was 66% at 2 years and 39% at 5 years, compared with 85 and 52% among age- and sex-matched controls.

CONCLUSIONS

Aortic surgery utilizing HCA in octogenarians can be performed with an acceptable risk of mortality and stroke. From the evidence in this study, it seems that elective aneurysm repair via a median sternotomy can be undertaken for the usual indications, even in octogenarians. However, the enhanced vulnerability of the brain in the elderly is reflected by a high early mortality following stroke, and a high incidence of TND. Emergency operations increase the possibility of adverse outcome dramatically, and patients who require a lateral thoracotomy are at significantly higher risk than those operated via a median sternotomy.