Is aortic surgery using hypothermic circulatory arrest in octogenarians justifiable?

Aortic Arch and Descending Thoracic Aortic Aneurysms: Experience with Stent Grafting for Second-Stage “Elephant Trunk” Repair

Reconstruction of aortic arch and descending thoracic aortic aneurysms (TAAs) is technically challenging and associated with significant morbidity and mortality. We report our experience with extensive TAAs using a two-stage “elephant trunk” repair, with the second stage completed using an endovascular stent graft (ESG). Over 6 years, 111 patients underwent ESG treatment of TAAs at Mount Sinai Medical Center. Twelve of these patients were referred for ESG placement for the second stage of elephant trunk reconstruction because comorbidities placed them at high risk of open surgical repair. Our database was analyzed for technical and clinical success and perioperative complications. The mean follow-up was 11.8 months (range 1–64 months). Twelve patients (five women and seven men) with a mean age of 69 ± 10 years underwent repair of their distal aortic arch and descending TAAs. These aneurysms included nine atherosclerotic aneurysms, one pseudoaneurysm, and two penetrating atherosclerotic ulcers. Three patients were symptomatic. Stent graft repair was technically successful in 91.7% or 11 of 12 patients. Excessive aortic arch tortuosity resulted in failure to deploy a stent graft in one patient. An antegrade approach through the open elephant trunk was used in two patients with severe iliac occlusive disease. Endoleaks (type 2) were identified in two patients with no aneurysm expansion; however, a 14 mm expansion over 1 year occurred in a patient with no identifiable endoleak. One early mortality occurred in a patient with a ruptured 6 cm infrarenal AAA after successful exclusion of the 8 cm TAA. Second-stage elephant trunk reconstruction of an extensive TAA using an ESG is effective in the short term. Its long-term durability remains to be determined.

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.

Limitations of EuroSCORE for measurement of risk-stratified mortality in aortic arch surgery using selective cerebral perfusion: is advanced age no longer a risk?

BACKGROUND

The European system for cardiac operative risk evaluation (EuroSCORE) is a risk stratification tool for perioperative mortality of cardiothoracic surgery that was developed in Europe and validated in North America in more than 500,000 patients. The operative mortality of aortic arch surgery has been improved by various novel operative techniques and adjuncts, whereas the number of such procedures for elderly patients has recently been increasing. The aim of this study was to examine the usefulness of the EuroSCORE, and our modification of it regarding age, in predicting mortality after aortic arch repair performed with selective cerebral perfusion.

METHODS

We reviewed 358 consecutive patients with a mean age of 69 +/- 10 years undergoing aortic arch repair with selective cerebral perfusion between January 1993 and February 2004. Observed in-hospital mortality was compared with predicted mortality as determined by both additive and logistic EuroSCOREs. We also evaluated a version of the EuroSCORE modified for age, which was obtained by subtracting the contribution of age from the original EuroSCORE. Score validities were assessed by calculating the areas under receiver operating characteristic curves.

RESULTS

Overall hospital mortality was 6.2% compared with 7.7% (additive EuroSCORE) and 11.8% (logistic EuroSCORE). Area under the receiver operating characteristic curve was 0.58 for the additive EuroSCORE and 0.58 for the logistic EuroSCORE as well. The overall age-unrelated EuroSCOREs were 5.1% (additive) and 5.2% (logistic), respectively, and areas under the receiver operating characteristic curve were 0.70 for additive and 0.69 for logistic.

CONCLUSIONS

The original additive and logistic EuroSCOREs overpredicted mortality in this patient group, whereas the age-unrelated EuroSCORE was better in predicting mortality.

Axillary Versus Femoral Cannulation for Aortic Surgery: Enough Evidence for a General Recommendation?

There is a trend towards cannulation of the axillary artery for extracorporeal circulation in patients requiring aortic arch surgery. We analyzed the published data comparing axillary and femoral cannulation for safety and outcome. End points were death; stroke, neurologic, and vascular complications; and malperfusion. Femoral cannulation is safe for extracorporeal circulation in patients without aortic arch surgery. In patients with type A dissections, malperfusion may occur owing to retrograde perfusion of the false lumen and subsequent occlusion of the origin of the supra aortic vessels. Cannulation of the axillary/subclavian artery results in antegrade flow, at least in the right carotid artery, with the possibility of antegrade cerebral perfusion during aortic arch repair. There was a trend towards improved neurologic outcome when the axillary artery was used for extracorporeal circulation in such patients. When different techniques were compared, the use of a side graft for axillary cannulation reduced the complication rate. The lack of randomized trials and the high variety of inclusion criteria in the different studies do not allow a general recommendation for the use of the axillary artery as cannulation site.

Impact of volume status on the incidence of atrial fibrillation following aortic arch repair

We evaluated the volume status of patients undergoing aortic arch repair to determine the impact of fluid balance on risk of postoperative atrial fibrillation (AF). From 1993, 445 patients who underwent total aortic arch repair were enrolled in this study. Patients who had AF preoperatively or died within the 10th postoperative day (POD) were excluded. Volumes administered (input) and eliminated (output) through all routes were recorded, and fluid balance (input minus output) was calculated intraoperatively, on the day of surgery, and PODs 1-2. The incidence of new onset of AF was 53.9% (240/445). Total input on POD 1 was greater in patients developing AF than in those not developing it (3,372 +/- 90 vs 3,012 +/- 79; P = 0.0036), as was net fluid balance on POD 1 as well (-806 +/- 84 vs -558 +/- 90; P = 0.050). Blood transfusion volume was greater in patients developing AF than in those not developing it on POD 1 (1,285 +/- 89 vs 927 +/- 74; P = 0.003) and POD 2 (405 +/- 53 vs 227 +/- 47; P = 0.015). Increased input volume and net fluid balance on POD 1 are associated with an increased risk of postoperative AF in patients undergoing aortic arch surgery.

Surgical Management of Distal Arch Aneurysm: Another Approach With Improved Results

BACKGROUND

Surgical treatment for distal arch aneurysm carries the risk of stroke. Although left thoracotomy has been used for repair of distal arch aneurysm as a standard approach, we have performed total arch replacement under deep hypothermia with circulatory arrest through a midsternotomy for this subset of aneurysms.

METHODS

From January 1998 to February 2003, 119 patients underwent elective total arch replacement (mean age, 72.3 +/- 6.0 years) for distal arch aneurysm under deep hypothermia with circulatory arrest. Antegrade selective cerebral perfusion was used for brain protection. Arch vessels were independently reconstructed using quadrifurcated grafts. Concomitant procedures included tricuspid annuloplasty in 1 patient, aortic valve operations in 2, sinotubular junction plication in 6, and coronary artery grafting in 22.

RESULTS

The early mortality rate was 0.84% (1 of 119). The mean duration of circulatory arrest was 67.1 +/- 19.7 minutes. Perioperative stroke rate was 0.84% (1 of 119). This stroke occurred 9 days postoperatively in an 81-year-old man with a history of cerebral infarction. Other complications were reexploration for bleeding in 1 patient (0.84%) and respiratory failure in 6 (5.0%).

CONCLUSIONS

This operative approach for distal arch aneurysm featured a low mortality rate and low risk of perioperative stroke. Concomitant cardiac surgery could be performed routinely in standard fashion. Distal arch aneurysms that do not involve a large segment of the descending thoracic aorta can thus be repaired with low mortality and few cerebral complications through a midsternotomy.

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.

Diabetes and evidence of atherosclerosis are major risk factors for adverse outcome after elective thoracic aortic surgery

BACKGROUND

To predict risk after elective repair of ascending aorta and aortic arch aneurysms, we studied 464 consecutive patients.

METHODS

Adverse outcome (stroke or hospital death) was analyzed in 372 patients who underwent proximal repair and 92 patients who underwent aortic arch replacement from 1986 to the present. Preoperative risk factors with a P value less than.2 in a univariate analysis were entered into a multivariate model, and an equation incorporating independent risk factors was derived separately for proximal aorta and arch surgery.

RESULTS

Age more than 65 years (P =.04), diabetes (P =.02), cause (P =.01), and prolonged total cerebral protection time (duration of hypothermic circulatory arrest and selective cerebral perfusion, P =.001) were significant univariate risk factors for elective proximal aortic repair. Diabetes (P =.005, odds ratio 5.1), atherosclerosis (P =.003, odds ratio 4.0), and dissection (P =.048, odds ratio 2.5) were independent factors. For elective arch surgery, female sex (P =.07), age more than 65 years (P =.04), coronary artery disease (P =.02), diabetes (P =.06), cause (P =.07), and prolonged total cerebral protection time (P =.025) were univariate risk factors. Female sex (P =.05, odds ratio 4.7), coronary artery disease (P =.02, odds ratio 6.5), diabetes (P =.13, odds ratio 4.0), and total cerebral protection time (P =.03, odds ratio 1.02/min) were independent factors. To calculate risk of adverse outcome (P), enter 1 if factor is present, 0 if absent, and estimate total cerebral protection time (in minutes). [equation: see text].

CONCLUSION

In this large series of patients, the presence of diabetes and manifestations of atherosclerosis emerge as extremely important risk factors for adverse outcome after ascending aorta or arch surgery, displacing age. Multivariate equations derived from these data allow more precise calculation of risk for each individual contemplating elective surgery.

Comparative study of the natural history and operative outcome in patients 75 years and older with thoracic aortic aneurysm

Surgery for thoracic aortic aneurysm (TAA) in patients 75 years and older is a high risk, but data for their natural history are not available. In the present study the subjects were 62 patients with TAA aged on average 78 years (range, 75-85 years) enrolled between August 1994 and December 2001: 20 operatively treated patients (OPE) and 42 medically managed patients (MED). All of them had been included in the indication for TAA surgery at the time of consultation. Hospital mortality rates and survival rates (Kaplan-Meier method) were compared among emergency OPE, elective OPE, and MED. There were 136 total patient-years of follow-up. Actuarial survival in MED (ie, the natural history) was 83% at 1 year after consultation and 41% at 3 years. Hospital mortality rates in emergency and elective OPE were 27% (3/11) and 0% (0/9), respectively (p=0.22), and the corresponding 3-year survival rates were 44% and 83% (p=0.019). Actuarial survival in elective OPE was higher than that in MED (p=0.022), but that of emergency OPE was similar to that for MED (p=0.17). Patients aged 75 years and older with TAA should undergo an elective operation if the aneurysm diameter is larger than 6 cm and if the patient is asymptomatic and in good anatomicosurgical, physical, and social condition.

Early and late results of cardiac and thoracic aortic surgery in octogenarians: comparison with high-risk younger patients

Forty octogenarians (OCTO) undergoing a variety of cardiac and thoracic aortic surgeries using cardiopulmonary bypass (CPB) between 1994 and 2002 were retrospectively studied. The results were compared with those of high-risk younger patients aged less than 60 years (YOUNG) (n=89). All patients had an expected operative mortality of EuroSCORE 5 and over. The EuroSCORE score was 9.9+/-3.3 (range, 5-18) in the OCTO group and 6.8+/-2.3 (range, 5-16) in the YOUNG patients (p<0.0001). There were 4 (10%) and 10 (11%) hospital deaths, respectively (p>0.99). Major postoperative complications occurred in 50% of the OCTO and 36% of the YOUNG patients (p=0.17). There were 10 and 7 late deaths, respectively. Actuarial survival including hospital death was significantly lower in the OCTO group than in the YOUNG (p=0.033). Actuarial survival was significantly higher in female octogenarians than in male (p=0.046). The overall 3-year survival rate was 88+/-8% and 64+/-11%, respectively. Multivariate analysis showed that predictors of late death were male gender (p=0.0005) and a high EuroSCORE (p=0.0010). Cardiac and thoracic aortic surgery using CPB can be performed in octogenarians with an acceptable hospital mortality rate and gratifying medium-term survival results.

Does Profound Hypothermic Circulatory Arrest Improve Survival in Patients With Acute Type A Aortic Dissection?

Objective No evidence exists that profound hypothermic circulatory arrest (PHCA) improves survival or reduces the likelihood of distal aortic reoperation in patients with acute type A aortic dissection.

Methods Records of 307 patients with acute type A aortic dissection from 1967 to 1999 were retrospectively reviewed. The influence of repair using PHCA (n=121) versus without PHCA (n=186) on death and freedom from distal aortic reoperation was analyzed using multivariable Cox regression models. Propensity score analysis identified a subset of 152 comparable patients in 3 quintiles (QIII–V) in which the effects of PHCA (n=113) versus no PHCA (n=39) were further compared.

Results For all patients, 30-day, 1-year, and 5-year survival estimates were 81±2%, 74±3%, and 63±3% (±1 SE). Survival rates and actual freedom from distal aortic reoperation was not significantly different between treatment methods in the entire patient cohort nor in the matched patients in quintiles III–V. Treatment method was not associated with differences in early major complications, late survival, or distal aortic reoperation rates in the entire patient sample or in quintiles III–V.

Conclusions Aortic repair with or without circulatory arrest was associated with comparable early complications, survival, and distal aortic reoperation rates in patients with acute type A aortic dissection. Despite the lack of concrete evidence favoring the use of PHCA, it does no harm, and most of our group uses PHCA regularly because of its practical technical advantages and theoretical potential merit.