Influence of retrograde cerebral perfusion during aortic arch procedures

Long-term outcomes of hemiarch replacement with hypothermic circulatory arrest and retrograde cerebral perfusion

OBJECTIVE

This study sought to report outcomes of hemiarch replacement with hypothermic circulatory arrest and retrograde cerebral perfusion, and secondarily, to report outcomes of this operative approach by type of underlying aortic disease.

METHODS

This was an observational study of aortic surgeries from 2010 to 2018. All patients who underwent hemiarch replacement with retrograde cerebral perfusion were included, whereas patients undergoing partial or total arch replacement or concomitant elephant trunk procedures were excluded. Patients were dichotomized into 2 groups by underlying aortic disease; that is, acute aortic dissection (AAD) or aneurysmal degeneration of the aorta. These groups were analyzed for differences in short-term postoperative outcomes, including stroke and operative mortality (Society of Thoracic Surgeons definition). Multivariable Cox analysis was performed to identify variables associated with long-term survival after hemiarch replacement.

RESULTS

A total of 500 patients undergoing hemiarch replacement with hypothermic circulatory arrest plus retrograde cerebral perfusion were identified, of whom 53.0% had aneurysmal disease and 47.0% had AAD. For the entire cohort, operative mortality was 6.4%, whereas stroke occurred in 4.6% of patients. Comparing AAD with aneurysm, operative mortality and stroke rates were similar across each group. Five-year survival was 84.4% ± 0.02% for the entire hemiarch cohort, whereas 5-year survival was 88.0% ± 0.02% for the aneurysm subgroup and was 80.5% ± 0.03% for the AAD subgroup. On multivariable analysis, AAD was not associated with an increased hazard of death, compared with aneurysm (P = .790).

CONCLUSIONS

Morbidity and mortality after hemiarch replacement with hypothermic circulatory arrest plus retrograde cerebral perfusion are acceptably low, and this operative approach may be as advantageous for AAD as it is for aneurysm.

Intraoperative neurophysiologic monitoring during aortic arch surgery

OBJECTIVE

To evaluate the ability of intraoperative neurophysiologic monitoring (IONM) during aortic arch reconstruction with hypothermic circulatory arrest (HCA) to predict early (<48 hours) adverse neurologic events (ANE; stroke or transient ischemic attack) and operative mortality.

METHODS

This was an observational study of aortic arch surgeries requiring HCA from 2010 to 2018. Patients were monitored with electroencephalogram (EEG) and somatosensory evoked potentials (SSEP). Baseline characteristics and postoperative outcomes were compared according to presence or absence of IONM changes, which were defined as any acute variation in SSEP or EEG, compared with baseline. Multivariable logistic regression analysis was used to assess the association of IONM changes with operative mortality and early ANE.

RESULTS

A total of 563 patients underwent aortic arch reconstruction with HCA and IONM. Of these, 119 (21.1%) patients had an IONM change, whereas 444 (78.9%) did not. Patients with IONM changes had increased operative mortality (22.7% vs 4.3%) and increased early ANE (10.9% vs 2.9%). In multivariable analysis, SSEP changes were correlated with early ANE (odds ratio [OR], 4.68; 95% confidence interval [CI], 1.51-14.56; P = .008), whereas EEG changes were not (P = .532). Permanent SSEP changes were correlated with early ANE (OR, 4.56; 95% CI, 1.51-13.77; P = .007), whereas temperature-related SSEP changes were not (P = .997). Finally, any IONM change (either SSEP or EEG) was correlated with operative mortality (OR, 5.82; 95% CI, 2.72-12.49; P < .001).

CONCLUSIONS

Abnormal IONM events during aortic arch reconstruction with HCA portend worse neurologic outcomes and operative mortality and have a negative predictive value of 97.1%. SSEP might be more sensitive than EEG for predicting early ANE, especially when SSEP changes are permanent.

Neuroprotective Strategies in Repair and Replacement of the Aortic Arch

Aortic arch surgery is a technical challenge, and cerebral protection during distal anastomosis is a continued topic of controversy and discussion. The physiologic effects of hypothermic arrest and adjunctive cerebral perfusion have yet to be fully defined, and the optimal strategies are still undetermined. This review highlights the historical context, physiological rationale, and clinical efficacy of various neuroprotective strategies during arch operations.

Ascending aorta reinterventions

Ascending aorta reinterventions present a challenge for surgeons as the technical difficulties of the procedure and the complex strategic approach can complicate successful treatment. These patients should be treated by surgical teams with ample experience in aortic diseases as they can be at high risk of mortality. The number of interventions on the ascending aorta and aortic arch and the use of biological conducts (lung autograft, homograft, etc.) have increased in recent years; therefore, the number of reinterventions can also be expected to increase, representing 10% of aortic surgical procedures. This article reviews the current status of ascending aorta reinterventions, analyzing the principal aspects of indication and surgical strategy, as well as the results published in the largest studies.

Deep hypothermic circulatory arrest

Effective cerebral protection remains the principle concern during aortic arch surgery. Hypothermic circulatory arrest (HCA) is entrenched as the primary neuroprotection mechanism since the 70s, as it slows injury-inducing pathways by limiting cerebral metabolism. However, increases in HCA duration has been associated with poorer neurological outcomes, necessitating the adjunctive use of antegrade (ACP) and retrograde cerebral perfusion (RCP). ACP has superseded RCP as the preferred perfusion strategy as it most closely mimic physiological perfusion, although there exists uncertainty regarding several technical details, such as unilateral versus bilateral perfusion, flow rate and temperature, perfusion site, undue trauma to head vessels, and risks of embolization. Nevertheless, we believe that the convenience, simplicity and effectiveness of straight DHCA justifies its use in the majority of elective and emergency cases. The following perspective offers a historical and clinical comparison of the DHCA with other techniques of cerebral protection.

Evolution in the techniques and outcomes of aortic arch surgery: a 22 year single centre experience

BACKGROUND

Aortic arch replacement is a complicated and high risk procedure. There have been many advances over recent years. We review the changes in our unit's techniques and outcomes over the past 22 years.

METHODS

Data were collated from databases and medical records for all patients who underwent aortic arch replacement surgery from January 1989 to December 2010. The patients were divided into two groups - Group A (1989-2005) and Group B (2006-2010). Data were analysed to compare early and late series patients' outcomes. Logistic regression was used to identify variables that predicted mortality.

RESULTS

Seventy-five eligible patients (56 males; mean age: 57.5 years; Group A: 40, Group B 35) were identified. There were great changes in the technique and the methods of cerebral protection. The overall mortality rate was 30.7% - Group A: 50% and Group B: 8.6% (p<0.001). Overall permanent neurological dysfunction was 23.7% - Group A: 40% and Group B: 11.8% (p=0.012). Cardiovascular disease and circulatory arrest time were significant predictors of mortality.

CONCLUSIONS

Increased experience and volume and advances in techniques over 22 years have resulted in major improvements in outcomes for patients having aortic arch replacement, allowing the procedure to be performed with greatly improved outcomes.

Recommendations for haemodynamic and neurological monitoring in repair of acute type a aortic dissection

During treatment of acute type A aortic dissection there is potential for both pre- and intra-operative malperfusion. There are a number of monitoring strategies that may allow for earlier detection of potentially catastrophic malperfusion (particularly cerebral malperfusion) phenomena available for the anaesthetist and surgeon. This review article sets out to discuss the benefits of the current standard monitoring techniques available as well as desirable/experimental techniques which may serve as adjuncts in the monitoring of these complex patients.

What is the best method for brain protection in surgery of the aortic arch? Straight DHCA

Straight deep hypothermic circulatory arrest (DHCA) is a technique available for brain preservation during deep hypothermic arrest in aortic arch replacement. In this article, the author discusses the practice of straight DHCA in his institute and the advantage of this technique over other brain preservation techniques.

Central Nervous System Protection in Cardiac Surgery

Neurological dysfunction and stroke following cardiac surgery and thoracic surgery requiring hypothermic circulatory arrest is a well-defined problem. The original studies in CABG patients identified risk factors, such as prior stroke and lower educational level. There is older evidence suggesting that higher perfusion pressures during cardiopulmonary bypass are helpful. Hyperthermia during rewarming on cardiopulmonary bypass and postoperative hyperthermia have been associated with adverse cognitive outcomes. Glucose management intraoperatively remains controversial, but most now advocate for moderate glucose control using insulin, if required. The subset of patients having thoracic aortic surgery requiring periods of aortic discontinuity are particularly problematic. A cerebral protection strategy should be determined, and this may include hypothermic circulatory arrest, selective cerebral perfusion, or retrograde cerebral perfusion. All of these techniques have been associated with good surgical outcomes, but there is little information on cognitive outcomes of thoracic aortic surgery.

Ascending and Transverse Aortic Arch Repair

Background— The benefit of retrograde cerebral perfusion (RCP) with profound hypothermic circulatory arrest has been subject to much debate. We examined our experience with ascending and transverse arch repairs to determine the impact of retrograde cerebral perfusion on stroke and mortality.

Methods and Results— Between August 1991 and June 2007, we performed 1107 repairs of the ascending and transverse aortic arch. RCP was used in 82% of cases (907 of 1107). Sixty-two percent were men (682 of 1107); median age was 64 years (range, 16 to 93 years). Perioperative variables were evaluated using univariate and multivariable analysis for mortality and stroke. Thiry-day mortality was 10.4% (115 of 1107). Stroke occurred in 2.8% (31 of 1107) of patients. Univariate risk factors for mortality were increasing age ( P <0.0001), history of coronary artery disease ( P =0.02), previous coronary artery bypass ( P =0.02), emergency status ( P <0.0001), acute dissection ( P =0.02), rupture ( P =0.0001), preoperative glomerular filtration rate, bypass time ( P <0.0001), crossclamp time ( P <0.007), RCP time ( P <0.0001), and packed red blood cell transfusions ( P =0.0001). Univariate risk factors for stroke included emergency status ( P <0.02), cerebrovascular disease ( P <0.02), and crossclamp time ( P <0.04). Independent risk factors for mortality were glomerular filtration rate <90 mL/min ( P =0.0004), emergency status ( P =0.006), rupture ( P =0.004), cardiopulmonary bypass time >120 minutes ( P <0.04), and packed red blood cell transfusions ( P =0.0002). Risk factors for stroke were emergency status ( P <0.009) and hypertension ( P <0.05). RCP was protective against mortality and stroke.

Conclusions— The use of RCP with profound hypothermic circulatory arrest was associated with a reduction in mortality and stroke. The use of RCP remains warranted during repairs of the ascending and transverse aortic arch.

Straight deep hypothermic arrest: experience in 394 patients supports its effectiveness as a sole means of brain preservation

BACKGROUND

The three methods of brain preservation for aortic arch surgery--straight deep hypothermic circulatory arrest (DHCA) without perfusion adjuncts, retrograde cerebral perfusion, and antegrade cerebral perfusion--remain controversial. Patients in this report underwent surgery solely with DHCA.

METHODS

Straight DHCA at 19 degrees C was used in 394 patients (267 males, 127 females) during a 10-year period. Mean age was 61.3 years (range, 15 to 88 years). Eighty-seven cases (22.1%) were urgent or emergencies. Thirty-eight (9.6%) were performed for descending or thoracoabdominal pathology and the rest for ascending/arch (102 hemiarch, 49 total arch). Ninety-one patients (23.1%) had dissections. The head was packed in ice. No barbiturate coma was used.

RESULTS

DHCA lasted a mean of 31.0 minutes (range, 10 to 66 minutes). Reexploration for bleeding was required in 4.5% (18/394). Overall mortality was 6.3% (25/394). Mortality was 3.6% (11/307) for elective cases and 16% (14/87) for emergency cases. The stroke rate was 4.8% (19/394). The seizure rate was 3.1% (12/394). Forty-five patients with high professional cognitive demands (MD, PhD, attorney, etc) performed without detriment postoperatively. Among patients with DHCA exceeding 40 minutes, the stroke rate was 13.1% (8/61); a neuroradiologist's review of brain computed tomography scans found 62.5% of these strokes (5/8) to be embolic and 37.5% (3/8) hypoperfusion related. By multivariable logistic regression, emergency operation and descending location increased morbidity and mortality.

CONCLUSIONS

Straight DHCA without adjunctive perfusion suffices as a sole means of cerebral protection. Stroke and seizure rates are low. Cognitive function, by clinical assessment, is excellent. Especially for straightforward ascending/arch reconstructions, there is little need for the added complexity of brain perfusion strategies.

Totally normothermic aortic arch replacement without circulatory arrest

BACKGROUND

Various techniques have been proposed for cerebral protection during the surgical treatment of complex aortic disease. The authors propose a revisited strategy of normothermic replacement of the aortic arch to avoid limitations and complications of profound hypothermic circulatory arrest.

MATERIALS AND METHODS

From April 2000 to May 2006, 19 patients with an aneurysm of the aortic arch and 10 patients with an acute (7) or a chronic (3) aortic dissection underwent a totally normothermic, complete replacement of the aortic arch using three pumps: One pump ensured antegrade cerebral perfusion, at a flow rate adapted to obtain a pressure of 70 mmHg in the right radial artery, and required a selective cannulation of the supra-aortic vessels. A second pump ensured body perfusion at a flow rate adapted to obtain a pressure of 55 mmHg in the left femoral artery and was situated between the right femoral artery and the right atrium. A special balloon aortic occlusion catheter was placed in the descending thoracic aorta. A third pump ensured intermittent normothermic myocardial perfusion via the coronary venous sinus. The arch reconstruction was performed with no time limit.

RESULTS

There were two operative, in-hospital (6.8%) mortalities. All others patients were rapidly extubated, except one, with no neurological sequelae, and postoperative course was uneventful, without coagulopathy or hepato-renal impairment.

CONCLUSIONS

In the light of these results, a normothermic procedure is possible for arch surgery and may ensure a more physiological autoregulation of cerebral blood flow while maintaining body perfusion without high vascular resistances.

Aortic Enlargement and Late Reoperation After Repair of Acute Type A Aortic Dissection

BACKGROUND

The natural history of the residual aorta after repair of acute type A aortic dissection is incompletely understood.

METHODS

During a 22-year period, 201 patients underwent repair of acute type A dissection by 25 surgeons. For 168 operative survivors, mean late follow-up for reoperation or death was 6.5 +/- 5.5 years and was 100% complete. Late blood pressure and medication history were available for 136 patients. Overall, 412 computed tomography scans were analyzed for segmental diameter and false lumen patency from 69 patients who underwent multiple follow-up imaging studies at our institution.

RESULTS

Freedom from reoperation at 10 years (range, 1 to 170 months) was 74% +/- 5% (28 reoperations in 26 patients). A nonresected primary tear (p = 0.05), Marfan syndrome (p < 0. 001), elevated systolic blood pressure at follow-up (p = 0.008), and absence of beta-blocker therapy (p = 0.02) were independent predictors of late reoperation. Aortic growth between consecutive imaging studies was detected in 18% of intervals (62/343) affecting 49% patients (34/69), with mean yearly growth rate of 5.3 +/- 4.5 mm. Onset of enlargement was unpredictable and occurred 59 +/- 45 months postoperatively (range, 1 to 167 months). Risk factors for growth included aortic diameter (p < 0. 001), elevated systolic blood pressure (p = 0.04), and presence of a patent false lumen (p = 0.05). Maximum aortic diameter of less than 35 mm predicted growth in 11% of intervals, 35 to 49 mm in 22%, and more than 49 mm in 37% (p < 0.001). Different proximal or distal surgical strategies did not affect aortic growth or need for reoperation (p > 0.17).

CONCLUSIONS

Optimal long-term outcome of patients with acute type A dissection demands rigorous antihypertensive therapy and lifelong radiographic follow-up because aortic enlargement can begin more than a decade postoperatively.

Impact of Perfusion Strategy on Neurologic Recovery in Acute Type A Aortic Dissection

BACKGROUND

The optimal perfusion strategy during surgery of acute type A aortic dissection is controversial. The purpose of this study was to determine the impact of retrograde cerebral perfusion during hypothermic circulatory arrest on short-term and long-term outcome in this specific patient population.

METHODS

Between 1984 and 2005, 175 consecutive patients underwent repair of an acute type A dissection. Three different surgical approaches were used: aortic cross-clamping without hypothermic circulatory arrest in 50 (29%), hypothermic circulatory arrest alone in 69 (39%), and hypothermic circulatory arrest with supplemental retrograde cerebral perfusion in 56 (32%).

RESULTS

Operative mortality was 18% +/- 3% (+/- 70% confidence interval), and adverse outcomes (death or cerebrovascular accident) occurred in 21% +/- 3% of patients (p = 0.97 between groups). Multivariate analysis identified valve replacement (p = 0.04), preoperative flow complications (p = 0.03), and non-Marfan syndrome (p = 0.04) as predictors of operative mortality. Intraoperative dissection (p < 0.001) and history of cerebrovascular disease (p = 0.02) were predictors for permanent neurologic deficit, and retrograde cerebral perfusion was shown to have a protective effect on transient neurologic deficits (p = 0.008). Kaplan-Meier survival was 75% +/- 3% at 1 year (131 patients at risk), 63% +/- 4% at 5 years (87 patients at risk), and 49% +/- 4% at 10 years (48 patients at risk) and was independent of surgical approach (p = 0.37). Long-term survival was diminished with increased age (p < 0.001), earlier operative year (p < 0.001), and coronary artery disease (p = 0.02).

CONCLUSIONS

The current investigation suggests improved neurologic recovery with circulatory arrest and supplemental retrograde cerebral perfusion. Operative mortality and long-term survival were comparable among groups.

Cerebral Perfusion

Aortic arch surgery necessitates interrupted brain perfusion and carries a risk of brain injury. Various brain protective techniques have been advocated to reduce risk including hypothermic arrest and retrograde or selective antegrade perfusion. Knowledge of the pathophysiologic consequences of deep hypothermia, may aid the surgeon in deciding when to initiate circulatory arrest and for how long. Retrograde cerebral perfusion use was advocated to prolong safe arrest durations but may not improve outcomes. Selective antegrade cerebral perfusion appears to have become the preferred method of brain protection. However, the delivery conditions and optimal perfusate constitution require further study.

Increased pressure during retrograde cerebral perfusion provides better preservation of the Na+, K+-ATPase activity

This study was carried out to determine if increased perfusion pressure during retrograde cerebral perfusion (RCP) provides better preservation of the brain Na+, K+-ATPase activity. Twenty pigs were subjected to anesthesia alone (control group, n =5), hypothermic circulatory arrest (HCA) (HCA group, n =5), HCA+RCP at perfusion pressures of 24-29 mmHg (Low-pressure group, n= 5), or HCA+RCP at perfusion pressures of 34-40 mmHg (High-pressure group, n =5). The brain was harvested for the measurement of tissue Na+, K+-ATPase activity. Relative to the control pigs (67.29∓2.1%), significant impairment of Na+, K+-ATPase activity was observed in all three experimental groups (29.89∓7.4% in HCA group, 33.59∓2.9% in the Low-pressure group, and 52.09∓1.8% in the High-pressure group, p <0.01). The best preservation of the enzyme, particularly in the cortex and cerebellum regions, was observed in the High-pressure group (p <0.01). In conclusion, HCA causes severe impairment of Na+, K+-ATPase activity, and increasing perfusion pressures from 24 +29 to 34 +40 mmHg during RCP significantly improves preservation of Na+, K+-ATPase activity, and the improvement of the protection varies in different regions of the brain.

Elective Surgery for Thoracic Aortic Aneurysms: Late Functional Status and Quality of Life

BACKGROUND

Elective surgical treatment for thoracic aortic aneurysms is unique in that it is often performed on asymptomatic patients. Although it has been found to improve survival, the impact of elective surgery on late functional status and quality of life have yet to be examined.

METHODS

Over a 5-year period, 110 asymptomatic patients underwent elective thoracic aortic replacement for ascending, descending, or thoracoabdominal aneurysms. Mean age was 67 +/- 9 years (53 > or = 70 years). Functional status, physical and psychological quality of life (Medical Outcome Study 36-Item Short Form Health Survey, in which 50 represents normalized age-matched US population), and survival (Kaplan-Meier) were assessed.

RESULTS

Return to normal activity level was independent of age (p > 0.59) and procedure (p > 0.18). At 35 +/- 20 months, psychological quality of life was similar between surgical groups (p > 0.71), but physical quality of life was lower after thoracoabdominal versus ascending or descending aneurysms (p < 0.02). Age did not impact physical quality of life (40 +/- 13 > or = 70 years versus 42 +/- 11 < 70 years, p > 0.58), but older patients had improved psychological quality of life (52 +/- 9 > or = 70 years versus 47 +/- 8 < 70 years, p > 0.03). Overall survival was 79% +/- 4% at 2 years and 70% +/- 5% at 4 years, but was lower with thoracoabdominal versus ascending or descending aneurysms (p < 0.002). Multivariate analysis identified thoracoabdominal (p < 0.004), advanced age (p < 0.03), chronic renal failure (p < 0.03), and congestive heart failure (p < 0.001) as predictors of late death.

CONCLUSIONS

Advanced age did not impair return to normal functional status, and older patients had improved psychological quality of life. Survival and physical quality of life were lowest with thoracoabdominal versus ascending or descending aneurysms. Thus, patients with asymptomatic thoracic aneurysms should not be denied elective replacement based on age alone, as functional recovery was not significantly impaired.

Perioperative Outcome in Adults Undergoing Elective Deep Hypothermic Circulatory Arrest With Retrograde Cerebral Perfusion in Proximal Aortic Arch Repair: Evaluation of Protocol-Based Care

OBJECTIVE

The purpose of this study was to describe perioperative outcome in adults undergoing elective proximal aortic arch repair with protocol-based deep hypothermic circulatory arrest (DHCA) with retrograde cerebral perfusion (RCP).

DESIGN

Retrospective and observational.

SETTING

Cardiothoracic operating rooms and intensive care unit.

PARTICIPANTS

Seventy-nine consecutive adults undergoing elective proximal aortic arch repair with DHCA (1999-2001).

INTERVENTIONS

None.

MAIN RESULTS

Average age of the patients was 64.9 years. Mean circulatory arrest time was 30.4 +/- 8.5 minutes. Perioperative mortality was 7.6%. Perioperative stroke incidence was 3.8%. Tracheal extubation was successful in 87.3% of patients within 24 hours of operation. Of the cohort, 80.8% were discharged from the intensive care unit within 72 hours of surgery. Median length of hospital stay was 7.4 days. Repeat mediastinal exploration because of bleeding occurred in 3.8% of patients. Although perioperative renal dysfunction (defined as >1.5-fold increase in plasma creatinine concentration) developed in 24.0% of patients, only 3.8% required dialysis.

CONCLUSIONS

The above parameters establish a baseline incidence for major perioperative complications in adults undergoing elective DHCA with RCP for elective proximal aortic arch repair. In approaching the open aortic arch for short periods of circulatory arrest, deep hypothermia with adjunctive RCP is safe and effective.

Does the arterial cannulation site for circulatory arrest influence stroke risk?

BACKGROUND

We investigated whether axillary/subclavian artery inflow with a side graft decreases the risk of stroke versus cannulation at other sites during hypothermic circulatory arrest.

METHODS

Between January 1993 and May 2003, 1,352 operations with circulatory arrest were performed for complex adult cardiac problems. A single arterial inflow cannulation site was used in 1,336 operations, and these formed the basis for comparative analyses. Cannulation sites were axillary plus graft in 299 operations, direct cannulation of the aorta in 471, femoral in 375, innominate in 24, and axillary or subclavian without a side graft in 167. Retrograde brain perfusion was used in 933 (69%). A total of 272 (20%) were for emergencies, 432 (32%) were reoperations, and 439 (32%) were for dissections. A total of 617 (46%) had aortic valve replacement and 1,160 (87%) ascending, 415 arch (31%), and 248 descending (18%) aortic replacements. Indications also included arteriosclerosis (n = 301) and calcified aorta (n = 278). Primary comparisons were made by using propensity matching, and, secondarily, risk factors for stroke or hospital mortality were identified by multivariable logistic regression.

RESULTS

Stroke occurred in 6.1% of patients (81/1,336): 4.0% (12/299) of those had axillary plus graft and 6.7% who had direct cannulation (69/1,037; p = 0.09; p = 0.05 among propensity-matched pairs). Operative variables associated with stroke included direct aortic cannulation, aortic arteriosclerosis, descending aorta repair, and mitral valve replacement. The risk of hospital mortality was higher (11%; 42/375) for patients who had femoral cannulation than axillary plus graft (7.0%; 21/299; p = 0.06; p = 0.02 among propensity-matched pairs).

CONCLUSIONS

Axillary inflow plus graft reduces stroke and is our method of choice for complex cardiac and cardioaortic operations that necessitate circulatory arrest. Retrograde or antegrade perfusion is used selectively.

Determinants of early and late outcome for reoperations of the proximal aorta

BACKGROUND

The purpose of this study was to investigate the cause of ascending aorta and aortic arch reoperations and to identify determinants of early and late outcome.

METHODS

Between January 1991 and March 2003 we repaired aneurysms of the proximal aorta in 597 patients. Of these patients, 104 had reoperations for replacement of the ascending aorta, aortic root, or transverse aortic arch. Previous surgery was defined as any previous cardiac or proximal aortic repair. Median age was 60 years, and 29 of the patients (28%) were female. Indications for reoperation and replacement of the proximal aorta included acute type A dissection in 6 patients (5.8%), aneurysm with chronic dissection in 60 (57.7%), progression of aneurysm in 23 (22.1%), infection in 12 (1.5%), inflammatory disease in 2 (1.9%), and atheromatous disease in 1 (1.0%). Reoperations included aortic root replacement in 20 patients (19.2%), total arch replacement with elephant trunk in 28 (26.7%), ascending and proximal arch in 39 (37.5%), and ascending aorta in 27 (26.0%). The median interval between operations was 69 months. Retrograde cerebral perfusion was used in 80 (77%) cases.

RESULTS

Chronic dissection was the most common indicator for reoperation in our population, followed by progression of aneurysm and infection. Thirty-day and in-hospital mortality was 13.5% (14 of 104) and 15.4% (16 of 104), respectively. Chronic obstructive pulmonary disease, renal dysfunction, and increased pump time were risk factors for mortality. Median follow-up was 5.02 years. Eight patients died during that period. Estimated survival at 1, 5, and 10 years was 83%, 80%, and 62%, respectively. Freedom from second proximal reoperations was 97.1% (10 of 104). Freedom from subsequent distal thoracic aortic repair was 84.6% (8 of 104).

CONCLUSIONS

Reoperations of the ascending aorta and aortic arch can be performed safely with good long-term results. Patients with previous proximal aortic dissection repair need long-term surveillance. Renal dysfunction and chronic obstructive pulmonary disease must be carefully considered before reoperations of the proximal aorta.

Minimized Mortality and Neurological Complications in Surgery for Chronic Arch Aneurysm:. Axillary Artery Cannulation, Selective Cerebral Perfusion, and Replacement of the Ascending and Total Arch Aorta

OBJECTIVE

Cerebral complication is still a major concern in surgery for arteriosclerotic aortic arch disease. For preventing this complication, axillary artery cannulation, selective cerebral perfusion, and replacement of the ascending and arch aorta were applied to thoracic aortic aneurysm involving aortic arch.

METHOD

From May 1999 to July 2002, consecutive 39 patients with true aneurysm (29 patients) or chronic aortic dissection (10 patients) involving aortic arch underwent replacement of the ascending and arch aorta with an elephant trunk under hypothermic cardiopulmonary bypass through the axillary artery cannulation and selective cerebral perfusion. The brain was continuously perfused without any intermission through the axillary artery. Concomitant operation included coronary artery bypass grafting (CABG) in two patients, aortic valve replacement (AVR) in one, Bentall operation in two, mitral valve replacement (MVR) in one, and aortic valve sparing operation in one. Patient age at operation was 40-84 (72 + 9) years and 24 of them were older than 70 years of age.

RESULTS

There was one operative death (2.5%) due to bleeding from the left lung, and one hospital death due to respiratory failure. Postoperative permanent neurological dysfunction was found in one patient (2.5%). Two patients presented temporary neurological dysfunction (5%). Thirty-six of the 39 patients were discharged from hospital on foot.

CONCLUSION

Continuous perfusion through the axillary artery with selective cerebral perfusion and replacement of the ascending and arch aorta may minimize cerebral complication leading to satisfactory results in patients with chronic aortic aneurysm involving aortic arch.

Contemporary Results of Total Aortic Arch Replacement

BACKGROUND AND AIM

Aneurysmal dilatation of the aortic arch is uncommon, and the complex anatomy involved imposes unique technical challenges. The results of surgical intervention reported from large centers are improving; however, the degree to which these results are reproducible by other surgeons is less clear. We therefore reviewed our recent experience with total aortic arch replacement.

METHODS

Between July 1, 1997 and July 1, 2001 19 patients underwent complete aortic arch replacement, with or without concomitant procedures. We retrospectively reviewed perioperative results retrieved from the computerized database and clinical records.

RESULTS

The mean age of the study population was 68 +/- 8.3 years (range 52 to 82), with women predominating (11 women, 8 men). All patients had hypertension. Patient history indicated active or past tobacco abuse in 16 patients (80%); cerebrovascular disease in 3, and peripheral vascular disease in 7 patients. Associated procedures included an elephant trunk in 12 (63%), replacement of the upper descending thoracic aorta in 5 (26%), concomitant coronary artery bypass in 5 (26%), and aortic root replacement in 3 (16%). One patient underwent replacement of the entire aorta from sinotubular ridge to iliac bifurcation in a single procedure. Brachiocephalic reconstruction with a "Y-graft" permitting early antegrade cerebral perfusion was performed in 12 patients. Retrograde cerebral perfusion was performed in ten patients (53%). Perioperatively, death occurred in two patients (11%) and stroke in two (11%).

CONCLUSIONS

With cautious application, techniques developed in high-volume centers can also achieve satisfactory results when used at centers with a more modest case volume.

Antegrade cerebral perfusion with hypothermic circulatory arrest: a case report

Techniques for the surgical correction of aortic aneurysms have steadily improved since the first described successful repair in 1955 by DeBakey et al. Despite these improvements, postoperative neurological complications remain a major factor in determining an adverse outcome. By using Deep Hypothermic Circulatory Arrest (DHCA), Retrograde Cerebral Perfusion (RCP) and now Selective Antegrade Cerebral Perfusion (SACP), the surgeon may provide better cerebral protection during extensive arch reconstruction. A 73-year-old female presented with an abnormal chest X-ray. Computerized tomography scan revealed a 4.5 cm mid aortic saccular arch aneurysm. Surgical intervention using cardiopulmonary bypass (CPB) with systemic cooling to 24 degrees C was employed. SACP was administered via cannulation of the innominate artery and the left common carotid artery using pediatric cannulae. Flow rates of 10 mL/kg/min and perfusion pressures of 60-90 mmHg were employed. Transcranial oximetry was used to monitor cerebral oxygen consumption. Circulatory arrest with SACP lasted for 36 min. Total bypass time was 178 min and myocardial ischemic time was 63 min. The patient was discharged on postoperative day five with no evident sequelae. While RCP has many benefits, SACP as used in this procedure may further improve patient outcome.

Total aortic arch grafting via median sternotomy using integrated antegrade cerebral perfusion

BACKGROUND

In aortic arch grafting, antegrade cerebral perfusion prolongs the safe time of arch exclusion. However, there are the problems of cerebral embolism and distribution of the cerebral perfusion. We describe and analyze mortality and cerebral complications in patients undergoing total arch grafting using our refined technique.

METHODS

Between June 1994 and March 2002, 100 consecutive patients underwent total arch grafting through median sternotomy. There were 49 atherosclerotic aneurysms and 51 aortic dissections. Fifty-four patients were operated on an emergency basis because of rupture or acute type A dissection. We conducted total arch grafting using hypothermic antegrade cerebral perfusion from every cervical vessel. Carbon dioxide gas was added to the cerebral perfusion in order to inhibit the increase in the cerebral vascular resistance during hypothermic cerebral perfusion.

RESULTS

Hospital mortality was 4%. The causes of death were dysarrhythmia (n = 1), mesenteric necrosis (n = 1), and preoperative cardiac arrest (n = 2). On univariate analysis, preoperative shock and concomitant cardiac procedures were risk factors for hospital death. The rate of postoperative neurologic damage was 5%. Two patients suffered from cerebral infarction. Temporary neurologic dysfunction occurred in 3 patients. On univariate analysis, emergency surgery was a risk factor for postoperative neurologic damage. On multivariate analysis, there was no significant independent predictor of hospital mortality and neurologic damage. Actuarial survival at 96 months was 66.4 +/- 9.1%, and freedom from aortic accidents (reoperation, rupture, and cholesterol embolism) was 74.9 +/- 7.9%.

CONCLUSIONS

The early- and long-term results of total arch grafting using integrated antegrade cerebral perfusion were found to be satisfactory.

Neuropsychometric outcome following aortic arch surgery: a prospective randomized trial of retrograde cerebral perfusion

BACKGROUND

Aortic surgery requiring hypothermic circulatory arrest is associated with a high incidence of brain injury. However, knowledge of neuropsychometric outcome is limited. Retrograde cerebral perfusion has become a popular adjunctive technique to hypothermic circulatory arrest. The aim of this study was to assess neuropsychometric outcome and compare the 2 techniques.

METHODS

In a prospective randomized trial, 38 patients requiring elective aortic arch surgery were allocated to either hypothermic circulatory arrest plus retrograde cerebral perfusion or hypothermic circulatory arrest alone. Neuropsychometric testing was performed preoperatively, and at 6 weeks and 12 to 24 weeks postoperatively. Deficit was defined as a 20% decline in 2 tests or more. Standardized Z scores were calculated for each patient and test. Eighteen patients underwent hypothermic circulatory arrest and 20 patients underwent hypothermic circulatory arrest plus retrograde cerebral perfusion. The mean cardiopulmonary bypass, hypothermic circulatory arrest, and retrograde cerebral perfusion durations were 169, 30, and 25 minutes, respectively.

RESULTS

There were 2 deaths and 2 neurological deficits. At 6 weeks postoperatively, 77% of the hypothermic circulatory arrest group and 93% of the hypothermic circulatory arrest plus retrograde cerebral perfusion group had a deficit (P =.22). At 12 weeks this was reduced to 55% and 56%, respectively (P =.93). There was a worse total Z test score in the hypothermic circulatory arrest plus retrograde cerebral perfusion group at 12 weeks (P =.05). Neuropsychometric change did not correlate with hypothermic circulatory arrest duration, presence of aortic atheroma, cannulation technique, or procedure.

CONCLUSIONS

Hypothermic circulatory arrest plus/minus retrograde cerebral perfusion is associated with a high incidence of neuropsychometric change despite ostensibly normal clinical outcomes and apparently safe arrest duration. Retrograde cerebral perfusion did not improve outcome in this small study.