Total arch replacement using aortic arch branched grafts with the aid of antegrade selective cerebral perfusion

Simple and Uniform Technique for Combined Repair of Aortic Arch and Root Replacement

We present herein a simple and uniform repair technique for combined aortic arch and root aneurysms. Our method is performed under an open distal procedure and includes selective antegrade cerebral perfusion, adequate myocardial preservation, a four-branched composite valve graft, and a long elephant trunk anastomosis proximal to the innominate artery. The technique was designed to reduce morbidity and mortality associated with aortic arch and root replacements, as well as allow for easier performance of subsequent downstream operations.

Cannulation of the innominate artery during surgery of the thoracic aorta: our experience in 55 patients

BACKGROUND

Alternative cannulation sites such as the right/left axillary artery, the ascending aorta and aortic arch have been recently preferred to the femoral artery to improve neurologic outcome in patients undergoing surgery of the thoracic aorta. In 2004, we started to select the innominate artery as an arterial cannulation site for CPB and antegrade cerebral perfusion institution. Here we present our preliminary experience with 55 patients.

METHODS

Between November 2004 and 2006, 55 patients (mean age 60+/-14 years) underwent surgery on the thoracic aorta using the innominate artery as a site for arterial cannulation. Indication for surgery was a degenerative aneurysm in 49 (89.1%), an acute type A dissection in 2 patients (3.6%), a post-dissection aneurysm in 3 (5.4%), a supravalvular aortic stenosis in 1 patient (1.8%). Operative procedure included total arch replacement (n=9), hemiarch replacement (n=6), ascending aorta replacement (n=21), Bentall procedure (n=18) and aortoplasty with patch (n=1). Mean CPB and cross clamp times were 131+/-60 and 95+/-29 min, respectively. Mean cerebral perfusion time was 54+/-26 min.

RESULTS

The hospital mortality rate was 3.6%. There were no permanent neurologic dysfunction and one (1.8%) temporary neurological dysfunction.

CONCLUSION

Our results with the cannulation of the innominate artery were encouraging. This provides the same advantages of the axillary artery cannulation with greater simplicity and avoiding extra surgical incisions which may be site for local complications. It may represent a valid option for CPB and antegrade cerebral perfusion institution in aortic procedures.

Endovascular treatment of atherosclerotic and other thoracic aortic aneurysms

The incidence of thoracic aortic aneurysms (TAAs) is increasing with the present rate of occurrence at 10.9 cases per 100,000 people per year. The estimated 5-year risk of rupture of a TAA with a diameter between 4 and 5.9 cm is 16%, but it rises to 31% for aneurysms ≥ 6 cm. Despite increasing awareness of the importance of early diagnosis and treatment options, there are no clear guidelines available at the time of writing. Nor is there any clear evidence for specific pharmacological treatment able to resolve or delay the disease progression. Endovascular treatment (EVT), proposed as an alternative to surgery, has been considered a therapeutic innovation, especially because it is minimally invasive, which allows treatment even in high surgical risk patients. Vascular imaging is crucial for patient selection, endoprosthesis choice, and planning of the treatment because not all aneurysms are suitable. Early and midterm results are encouraging, but long-term results are necessary to definitively assess reliability of stent-graft materials and improvement in patient survival. In the choice between surgical or endovascular repair of TAAs, many factors must be considered, including the clinical situation, comorbidities, anatomy, choice of equipment, and last, but not less important, experience of the clinical team.

The Hybrid Total Arch Repair: Brachiocephalic Bypass and Concomitant Endovascular Aortic Arch Stent Graft Placement

BACKGROUND

Repair of aortic arch aneurysm is technically demanding, requiring complex circulatory management. Very large atherosclerotic saccular aneurysms of the arch are grave markers of extensive arch and brachiocephalic atheromatous disease and represent high surgical risks for perioperative neurologic complications. Operative morbidity and mortality may be prohibitive with traditional surgical intervention. We described our experience with a hybrid procedure for total arch repair with a brachiocephalic bypass with a trifurcated graft followed by concomitant placement of a stent graft in the arch.

METHODS

Since June 2005, we have performed the hybrid total arch repair in eight patients. A retrospective review was performed to evaluate the new technique.

RESULTS

The mean age of the patients was 67 years with a mean aneurysm size of 8 cm (range, 4.4 to 10 cm). Significant comorbidities included carotid stenosis, chronic renal insufficiency, peripheral vascular disease, hypertension, and coronary artery disease. Two patients had previous Abdominal aortic aneurysm (AAA) repairs. Three patients had previous sternotomy for type A dissection, ascending aortic aneurysm repair, and coronary artery bypass grafting. Transesophageal echocardiogram demonstrated grade IV or V atheromatous disease in the arch and ascending aorta. Stent grafts were deployed antegrade directly into the ascending aorta in three patients and retrograde from the femoral artery in five patients. Technical success with complete aneurysmal exclusion was achieved in all patients (100%). At a mean follow-up period of 11.7 months, there was no incidence of endoleak. There was one death resulting from a perioperative myocardial infarction (first patient). Documented perioperative neurologic events (stroke) occurred in two patients, with both patients demonstrating no residual deficit at the time of discharge.

CONCLUSIONS

Saccular arch aneurysms can be technically treated by total arch repair with brachiocephalic bypass and concomitant aortic arch stent graft placement. Hybrid arch repair provides an alternative to patients otherwise considered prohibitively high risk for traditional open arch repair.

Effect of prophylactically administered edaravone during antegrade cerebral perfusion in a canine model of old cerebral infarction

OBJECTIVE

Reactive free radical species are thought to be involved in postoperative neurologic dysfunction after antegrade selective cerebral perfusion in brains with old infarction. We assessed the brain protective effect of prophylactically administered edaravone, a free radical scavenger, for antegrade selective cerebral perfusion in brains with or without old infarction in a canine model.

METHODS

A canine model of old cerebral infarction was created by injecting cylindric silicone embolus into the middle cerebral artery. Animals showing obvious neurologic deficits and surviving 4 weeks or longer were included in the model. Deep hypothermia with antegrade selective cerebral perfusion was performed in both intact (non-edaravone, group A; edaravone-treated, group B) and infarcted animals (non-edaravone, group C; edaravone-treated, group D). Serum concentrations of malondialdehyde, hexanoyl-lysine, glutamate, and venous-arterial lactate difference were measured, and central conduction time and amplitude of somatosensory evoked potentials were assessed during the operation.

RESULTS

Compared with the intact groups, serum concentrations of malondialdehyde and hexanoyl-lysine in group C significantly increased at the end of antegrade selective cerebral perfusion, whereas that of glutamate did so in the rewarming phase. Increases in all these biochemical parameters were suppressed in group D. In group C, the venous-arterial lactate difference was significantly greater in the rewarming phase at 28 degrees C compared with intact groups. A significant prolongation of postoperative central conduction time and decrease in neuronal activity were detected in group C, both of which recovered in group D.

CONCLUSION

Prophylactic administration of edaravone exerted a significant protective effect against postoperative neurologic dysfunction after antegrade selective cerebral perfusion in a canine model with old cerebral infarction.

Aortic Arch Replacement Using Selective Cerebral Perfusion

BACKGROUND

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.

METHODS

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.

RESULTS

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.

CONCLUSIONS

SCP facilitates complicated aortic arch replacement, resulting in a reduction of mortality and morbidity for arch aneurysms or dissections.

Aortic Arch Replacement With a Trifurcated Graft

BACKGROUND

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).

METHODS

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.

RESULTS

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.

CONCLUSIONS

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

BACKGROUND

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.

METHODS

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.

RESULTS

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.

CONCLUSIONS

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.

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.

Arch first technique under deep hypothermic circulatory arrest with retrograde cerebral perfusion

We have adopted the arch first technique with four-branched graft for total arch replacement since 1998 to reduce the period of deep hypothermic circulatory arrest and the retrograde cerebral perfusion time. This procedure was performed in 85 cases (58 males and 27 females), with an average age of 68 years. There were 61 true aneurysms, 21 aortic dissections and 3 others. Stroke was a complication in 6 cases (7%). Other morbidities were re-exploration for bleeding in 9, low output syndrome in 2, and renal dysfunction in 3. There were 3 hospital deaths (3.5%), 4 late deaths. The five-year survival rate was 89.1%. The arch first technique results in low surgical mortality and morbidity and provides a higher survival rate. The arch first technique is an excellent method for total arch replacement.

Total arch replacement: technique of separate reimplantation of epi-aortic vessels

Antegrade selective cerebral perfusion (SCP) with moderate hypothermia is the method of brain protection during aortic arch repair requiring a circulatory arrest longer than 30 min at our institute. It facilitates the total arch replacement using the aortic arch branched graft, and results in acceptable mortality and morbidity for arch aneurysm or dissection.

Aorto-right atrial fistula following acute type A aortic dissection repair

This report describes a rare case of aorto-right atrial fistula caused by rupture of a huge pseudoaneurysm that developed at the proximal aortic anastomotic site after total aortic arch replacement for acute type A aortic dissection. Preoperative aortography revealed that the fistula communicated with the right heart, but it was intraoperative Doppler transesophageal echocardiography that confirmed its course into the right atrium. Repeat total aortic arch replacement with concomitant direct closure of the fistula was performed successfully. The underlying cause of the pseudoaneurysm was the dehiscence of sutures at the proximal aortic anastomotic site, probably due to gelatin-resorcin-formaldehyde glue.

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

BACKGROUND

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.

METHODS

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.

RESULTS

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.

CONCLUSIONS

Axillary cannulation and SCP in the surgical treatment of proximal aortic pathology is safe in both elective and emergent settings.

Total Aortic Arch Replacement in Patients With Arch Vessel Anomalies

BACKGROUND

The presence of anomalous arch vessels has considerable impact on aortic arch reconstruction techniques and cerebral protection methods when the separated graft technique is adopted to perform total arch replacement. We analyzed our experience of total arch replacement in patients with arch vessel anomalies.

METHODS

Among the 220 patients undergoing total arch replacement at our institution, 21 patients (9.5%) had various arch vessel anomalies. Common brachiocephalic trunk was found in 8 patients (3.6%); an isolated left vertebral artery in 9 (4.1%); aberrant right subclavian artery in 3 (1.4%); and coexistent common brachiocephalic trunk and isolated left vertebral artery in 1 (0.5%). In 4 of the 9 patients with isolated left vertebral artery, preoperative diagnosis was possible with magnetic resonance angiography or three-dimensional computed tomography. In cases with common brachiocephalic trunk, total arch replacement could be performed with the usual techniques after separating the innominate and left common carotid arteries from each other. The isolated left vertebral artery was anastomosed to the left subclavian artery graft in 7 patients and to the native left subclavian artery in 2. In the aberrant right subclavian artery variety, a distal aortic anastomosis was performed distal to the orifice of this anomalous artery. The aberrant vessel was reconstructed on the right side of the trachea and esophagus.

RESULTS

There was no early or in-hospital mortality. No neurologic complication attributable to the arch vessel anomalies was found.

CONCLUSIONS

A precise preoperative diagnosis is very important for the selection of an appropriate surgical strategy in patients with arch vessel anomalies. Magnetic resonance angiography and three-dimensional computed tomography may be useful diagnostic tools in these patients.

Aortic Arch Surgery: Thoracoabdominal Perfusion During Antegrade Cerebral Perfusion May Reduce Postoperative Morbidity

BACKGROUND

This study aimed to assess the results of the introduction of thoracoabdominal perfusion (TAP) in the surgical strategy for aortic arch replacement with cerebral protection.

METHODS

Two hundred two arch procedures performed with moderate hypothermia (22 degrees to 26 degrees C) and antegrade cerebral perfusion (ACP) were the objects of retrospective investigation. Acute type A dissection was the indication in 164 patients, aortic aneurysm in 38. In 80 patients, during ACP, the thoracoabdominal aorta was perfused either in an antegrade fashion through proximal descending aorta endoluminal cannulation (in 62 dissections), or retrograde through femoral artery cannulation with proximal descending aorta endoluminal occlusion (in 18 aneurysms). Hospital mortality and morbidity rates were compared between the two treatments (group A: ACP only, 122 patients; group B: ACP plus TAP, 80 patients) and the underlying aortic disease (dissection/aneurysm) was stratified.

RESULTS

Cerebral perfusion (p = 0.008) and cardiopulmonary bypass times (p = 0.035) were significantly longer in group B. No complication related to the TAP technique was observed in group B. Overall hospital mortality was 12.9%, without significant difference between groups. No differences were found in terms of permanent neurological dysfunction between groups A (9.3%) and B (9.1%; p = 0.58). Group B patients showed lower rates of respiratory failure (18.2% versus 30.5% in group A; p = 0.038), shorter mechanical ventilation times (18.1 +/- 26 hours versus 57.9 +/- 70.1; p < 0.001) and lower incidence of acute renal failure (6.5% versus 18.6%; p = 0.012). Shorter intensive care and hospital stays were observed in group B (p = 0.02).

CONCLUSIONS

The adjunction of TAP to ACP was associated with lower rates of end-organ complications, even in more extensive and time-consuming procedures.

Aortic Reconstruction After Complex Injury of the Mid-Transverse Arch

We report the case of a 28-year-old man who suffered a transection of the mid-transverse aortic arch between the innominate and left common carotid artery with complete avulsion of the left common carotid artery after blunt trauma. This patient underwent successful aortic arch replacement proximal to the left subclavian artery and reimplantation of the innominate and left carotid arteries using profound hypothermic circulatory arrest and selective antegrade cerebral perfusion. A literature review revealed no other previous reports of survival after this type of injury.

Methods of cerebral protection in surgery of the thoracic aorta

During the last decade, a considerable increase in the number of operations on the thoracic aorta has been observed. Although patient's outcomes have improved considerably, this surgery is still associated with significant morbidity and mortality due to neurological complications. Various methods have been proposed and widely used as means to protect the brain from ischemic damage. This review summarizes the principal methods of cerebral protection, describes the advantages and disadvantages of each method and their impact on patient outcomes, and discusses the different surgical techniques proposed to minimize the risk of cerebral injuries.

Is it safe to initiate selective cerebral perfusion with normothermia?

OBJECTIVE

Preceding selective cerebral perfusion (P-SCP) is a method whereby SCP and systemic perfusion start simultaneously, and the arch vessels are clamped. Cerebral circulation is isolated from systemic circulation to avoid cerebral embolization due to detachment of atherosclerotic material from the aorta, caused by the "sandblasting" effect of high-velocity jets of blood exiting the aortic cannula. However, neither the safety of SCP at normothermia nor the influence of extended SCP time has been sufficiently clarified. To clarify the safety of P-SCP, the comparison study of P-SCP and conventional SCP (C-SCP) was performed retrospectively.

METHODS

Fifty-seven patients (C-SCP group: 29 patients; P-SCP: 28 patients) underwent surgery between 1992 and 2002.

RESULTS

Nine (15.8%) in-hospital death occurred; 4 in the C-SCP group (13.8%) and 5 in the P-SCP group (17.9%) (NS). The SCP time was 136.6 +/- 68.5 minutes in the C-SCP group and 195.8 +/- 30.7 minutes in the P-SCP group (p < 0.05). One patient in each group exhibited postoperative neurological dysfunction.

CONCLUSION

It may be little dangerous to initiate the SCP with normothermia. P-SCP may be useful in cases in which there is pedunculated atherosclerotic material, or mural thrombus in the ascending and arch aorta.

A newly designed holder for grafts with four side branches used in total arch replacement

Grafts with four presewn side branches have proven very useful for total aortic arch replacement worldwide. However, the four side branches often obscure the surgeon's view of the distal anastomotic site. Thus, we designed a holder for this graft, which sheaths and hides the graft body and branches, allowing the surgeon a better view of the distal anastomosis. By using this device, distal anastomosis can be achieved early and quickly without obstruction of the surgeon's view, resulting in reduced cardiac ischemic time in aortic arch surgery.

Experiences of Intentional Carotid Stenting in Endovascular Repair of Aortic Arch Aneurysms—Two Case Reports

Endovascular repair of thoracic aneurysms has emerged as an attractive alternative especially in patients at high risk. However, the left common carotid artery limits the use of stent-grafts in aneurysms located in the aortic arch or close to the left subclavian artery. We report two cases with aneurysms in the distal arch and proximal descending aorta, where we have used a carotid stent in juxtaposition to an aortic stent-graft, to gain a longer proximal neck in the aortic arch in an attempt not to rely only on a by-pass graft feeding the left carotid artery.

Aortic Arch Replacement Using a Trifurcated Graft: Simple, Versatile, and Safe

BACKGROUND

Hypothermic selective antegrade cerebral perfusion during aortic arch replacement may prevent adverse neurologic sequelae. It can be provided via balloon-tipped catheters or a branched graft sewn to the brachiocephalic vessels. We report a consecutive series of total arch replacement using a trifurcated graft.

METHODS

From September 1999 through October 2004, 109 patients underwent nonemergent total arch replacement using this technique. The graft, placed during a period of hypothermic circulatory arrest, was used for selective cerebral perfusion during the arch reconstruction.

RESULTS

Adverse outcomes were seen in 9 (8.3%) patients: hospital death in 5 (4.6%), and stroke in 5 (4.6%). Transient neurologic dysfunction was noted in 6 (5.5%) patients. Mean duration of hypothermic circulatory arrest was 31.2 +/- 6.6 minutes and selective cerebral perfusion was 65.3 +/- 20.9 minutes. Reoperation for bleeding was required in 3 (2.8%) patients and prolonged intubation in 15 (13.8%). Median intensive care unit stay was 3 days (interquartile range 2-4; range, 1 to 108) and hospital stay was 9 (interquartile range 8-15; range, 5 to 108).

CONCLUSIONS

The trifurcated graft technique results in low rates of perioperative mortality, temporary neurologic dysfunction, and stroke. It may reduce cerebral embolization as it requires no instrumentation of the aortic arch to establish selective cerebral perfusion and, although it mandates hypothermic circulatory arrest to place the graft, this interval is reliably brief enough to fall within accepted safe limits. This strategy leaves no residual arch tissue behind, and allows placement of an elephant trunk proximal to one or more arch vessels if anatomically indicated.

Selective antegrade cerebral perfusion attenuates brain metabolic deficit in aortic arch surgery: a prospective randomized trial

BACKGROUND

Aortic arch surgery has a high incidence of brain injury. This may in part be caused by a cerebral metabolic deficit observed after hypothermic circulatory arrest (HCA). We hypothesized that selective antegrade cerebral perfusion (SACP) would attenuate this phenomenon.

METHODS AND RESULTS

In a prospective randomized trial, 42 adult patients were allocated to either HCA (22) or SACP. HCA occurred at a nasopharyngeal temperature of 15 degrees C and SACP at a corporeal temperature of 25 degrees C with cerebral perfusion at 15 degrees C. Paired arterial and jugular venous samples were taken before and after arrest. Continuous transcranial Doppler monitoring of middle cerebral artery velocity (MCAV) was performed. Neuropsychometric testing was performed preoperatively and at 6 and 12 weeks postoperatively. There were 3 hospital deaths (7.1%), 2 strokes (4.8%), and 6 episodes of transient neurological deficit (14.3%). From before to after arrest, jugular bulb pO2 changed by -21.67 mm Hg (26.4) in the HCA group versus +2.27 mm Hg (18.8) in the SACP group (P=0.007). Oxygen extraction changed by +1.7 mL/dL (1.3) in the HCA group versus -1 mL/dL (2.4) in the SACP group (P<0.001). MCAV increased by 6.25 cm/s (9.1) in the HCA group and 19.2 cm/s (10.1) in the SACP group (P=0.001). Incidence of neuropsychometric deficit at 6 weeks was 6/12 (50%) in HCA patients and 8/10 (80%) in SACP patients (P=0.2), and at 12 weeks was 6/16 (38%) in HCA patients and 4/11 (36%) in SACP patients (P=1).

CONCLUSIONS

SACP attenuates the metabolic changes seen after HCA. Further studies are required to assess optimal perfusion conditions and clinical outcome.

Comparison of pH management during antegrade selective cerebral perfusion in canine models with old cerebral infarction

OBJECTIVE

We sought to examine the influence on the brain, with or without old infarction, of pH management during antegrade selective cerebral perfusion in a canine model.

METHODS

A cerebral infarct canine model was created by injecting a cylindrical silicone embolus. Dogs that had obvious neurologic deficits and had survived for 4 weeks or more were included in the model. Deep hypothermia with antegrade selective cerebral perfusion was performed in intact mongrel dogs (alpha-stat: group A, n = 6; pH-stat: group B, n = 6) and mongrel dogs with infarctions (alpha-stat: group C, n = 6; pH-stat: group D, n = 6). Maxillary vein saturation of oxygen, venous-arterial lactate difference, and serum concentrations of malondialdehyde and glutamate were measured and central conduction times and amplitude in somatosensory evoked potentials were assessed during the operation.

RESULTS

During the experimental procedure, the maxillary vein saturation of oxygen was significantly less (P <.05), whereas the venous-arterial lactate difference was significantly greater (P <.05) in the cooling phase to 28 degrees C in group C than in the other groups. The pH-stat group showed significantly greater arterial Paco(2) and lower pH than the alpha-stat group during the period between the cooling to 28 degrees C and the rewarming to 28 degrees C (P <.05). Other intraoperative parameters did not show any difference among the groups. In group C the serum concentrations of malondialdehyde and glutamate significantly increased, as did the central conduction time, whereas in both groups C and D the amplitude ratio decreased significantly.

CONCLUSIONS

This experiment suggests that pH-stat management during antegrade selective cerebral perfusion provides more effective protection for a brain with old infarction than alpha-stat management.

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.

Separate grafts or en bloc anastomosis for arch vessels reimplantation to the aortic arch

BACKGROUND

This study compares the results of the separated graft technique and the en bloc technique as a method of arch vessels reimplantation during surgery of the aortic arch and determines the predictive risk factors associated with hospital mortality and adverse neurologic outcome during aortic arch repair.

METHODS

Between October 1995 and March 2002, 352 patients (mean age 64.9 +/- 11.3 years; urgent status: 49/352 [13.9%]) underwent surgery of the aortic arch using the separated graft technique (group A: n = 230 [65.3%]) and the en bloc technique (group B: n = 122 [34.7%]) to reimplant the arch vessels. An aortic arch replacement was performed in 32 patients (9.1%), an ascending aorta and arch replacement in 222 patients (53.1%), an aortic arch and descending aorta replacement in 16 patients (4.5%), and a complete replacement of the thoracic aorta in 82 patients (23.3%). Brain protection was achieved by means of antegrade selective cerebral perfusion in all patients. The mean cardiopulmonary bypass time was 204.8 +/- 61.9 minutes (group A: 199.7 +/- 57.0 minutes; group B: 214.5 +/- 69.4 minutes; p = 0.033), the mean myocardial ischemic time was 121.5 +/- 43.2 minutes (group A: 116.7 +/- 38.9 minutes; group B: 130.80 +/- 49.4 minutes; p = 0.003), and the mean antegrade selective cerebral perfusion time was 84.5 +/- 36.4 (group A: separated graft technique 91.3 +/- 36.3 minutes; group B: 70.6 +/- 32.7 minutes; p = 0.000).

RESULTS

Overall hospital mortality was 6.8% (group A: 6.5%; group B: 7.4%; p = not significant [NS]). The permanent neurologic dysfunction rate was 3.5% (group A: 4.0%; group B: 2.5%; p = NS). The transient neurologic dysfunction rate was 5.4% (group A: 5.5%; group B: 5.2%, p = NS). Postoperative systemic morbidity was similar in the two groups. A logistic regression analysis revealed preoperative cardiac tamponade (p = 0.011; odds ratio [OR] = 5.9) and cardiopulmonary bypass time (p = 0.010; OR = 1.01/min) to be independent predictors of hospital mortality. None of the analyzed preoperative variables were associated with an increased risk of permanent neurologic dysfunction. Age more than 70 years old (p = 0.029, OR = 5.7), myocardial revascularization (p = 0.001, OR = 2.9), and pump time (p = 0.013, OR = 1.01/min) were indicated as independent predictors of transient neurologic dysfunction by logistic regression.

CONCLUSIONS

Antegrade selective cerebral perfusion was confirmed to be a safe method of cerebral protection allowing complex aortic arch operations to be performed with acceptable results in terms of hospital mortality and neurologic outcome. The separated graft technique had no adverse impact on hospital mortality and morbidity.

Technical advances in total aortic arch replacement

BACKGROUND

We compared the effects of using hypothermic circulatory arrest (HCA) alone, HCA combined with selective cerebral perfusion (SCP), and use of SCP with a trifurcated graft (T) on outcome after aortic arch repair.

METHODS

One hundred fifty patients, median age 66 years (range, 27 to 85), underwent total arch replacement between 1988 and 2002; 75 were female. We retrospectively compared the results of three patient groups roughly comparable with regard to preoperative risk factors: 45 patients using HCA beginning in 1988; 67 patients using HCA/SCP beginning in 1994; and 38 patients utilizing a trifurcated arch graft in conjunction with SCP through the axillary artery (HCA/SCP/T) since 2000. The groups were well matched with regard to median age (66, 68, and 66 years), urgency (emergent 11%, 13%, 5%; urgent 24%, 9%, 18%; and elective 64%, 78%, 76%), and several other known risk factors (p = not significant).

RESULTS

An adverse outcome-hospital death or permanent stroke-occurred in 14%: in 16% with HCA, in 16% with HCA/SCP, and in 8% with HCA/SCP/T. Transient neurologic dysfunction among patients surviving without stroke was lower with HCA/SCP/T (11%) than with HCA (33%) or HCA/SCP (17%). Mean duration of HCA was 52 +/- 16 minutes with HCA alone versus 45 +/- 10 minutes with HCA/SCP and 31 +/- 7 minutes with HCA/SCP/T (p < 0.0001 for groups HCA and HCA/SCP combined versus HCA/SCP/T). Mean duration of SCP was 57 +/- 25 minutes with HCA/SCP versus 62 +/- 24 minutes with HCA/SCP/T (p = not significant). Comparison of the groups of patients who had comparable preoperative risk factors for adverse outcome showed a trend toward lower adverse outcome and transient neurologic dysfunction rates using HCA/SCP/T; a significant reduction in respiratory (p < 0.001), infectious (p = 0.015) and cardiac (p = 0.005) complications in HCA/SCP/T compared with the earlier groups; and significantly shorter durations of intensive care (p < 0.0001) and hospitalization (p = 0.004).

CONCLUSIONS

Our results suggest that HCA/SCP is superior to HCA alone for preventing cerebral injury during operations on the aortic arch. By further reducing embolic risk as well as duration of HCA, HCA/SCP/T with axillary artery cannulation may be the optimal technique for averting adverse outcomes, reducing complications, and shortening hospital stay after aortic arch repair.

Mortality and morbidity after total arch replacement using a branched arch graft with selective antegrade cerebral perfusion

BACKGROUND

The early outcome after aortic arch surgery has improved. However, some operative survivors have died as a result of postoperative problems soon after discharge. This study determines the factors affecting mortality within 1 year of total arch replacement.

METHODS

Between July 1993 and November 2001, 103 patients (mean age 65 +/- 11 years, 26 women, 35 dissections) underwent total arch replacement through a median sternotomy using a branched arch graft with selective cerebral perfusion. Eighteen operations including 14 acute dissections were performed on an emergency basis. Concomitant procedures were root replacement in 5 patients, mitral valve replacement in 1, coronary artery bypass in 14, and open endovascular stent-graft in 9. The average time (minutes) for bypass, aortic cross-clamp, selective cerebral perfusion, and distal arrest were respectively 273 +/- 79, 163 +/- 54, 145 +/- 36, and 69 +/- 22.

RESULTS

Mechanical heart support was necessary in 3 patients. Stroke occurred in 9 patients, transient neurologic dysfunction in 7, and paraplegia/paraparesis in 4. The only independent determinant for postoperative stroke was a history of stroke (odds ratio 16.3, 95% confidence interval: 2.8 to 93.8). Thirty-one patients required ventilator support for more than 5 days. Hemodialysis was needed in 5 patients. Sternal infection or mediastinitis occurred in 6 patients. The in-hospital mortality was 12% (12 of 103). The actuarial survival rate at 1 year was 83%, and was 67% at 5 years. For the 1-year mortality independent determinants were emergency surgery (odds ratio 5.3, 95% confidence interval: 1.6 to 17.9) and age 75 years or older (odds ratio 4.0, 95% confidence interval: 1.1 to 13.9).

CONCLUSIONS

Total arch replacement using a branched arch graft with selective antegrade cerebral perfusion has a favorable 1-year mortality rate except for patients undergoing emergency surgery and for elderly patients.

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.

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.

Late reoperation for proximal aortic and arch complications after previous composite graft replacement in marfan patients

BACKGROUND

Marfan patients who received composite graft replacement for proximal aortic disease frequently require late reoperation. The initial surgical technique for this lesion remains controversial.

METHODS

Fourteen Marfan patients who received composite graft replacement for annuloaortic ectasia with or without aortic dissection required late reoperation thorough re-median sternotomy. The techniques used for an initial composite graft replacement were the original Bentall procedure in 11 patients, the Cabrol procedure in 2, and coronary button technique in 1. Reoperation was indicated for prosthesis-related complications in 10 patients, distal aortic lesion in 13, or for both lesions in 8. Reoperations were performed, on average, 8.4 years after an initial operation. Reoperative procedures included re-composite graft replacement in 1 patient, total arch replacement in 5, and re-composite graft replacement with total arch replacement in 8.

RESULTS

There were two in-hospital deaths (14.3%). Although pseudoaneurysms of the coronary artery or distal aorta occurred in the original Bentall or Cabrol procedures, true aneurysms of the coronary artery were noted even in the coronary button technique. Six patients required a total of eight subsequent descending or thoracoabdominal aortic replacements for an aneurysmal formation of a distal false lumen.

CONCLUSIONS

The coronary button technique, with a small side hole for coronary anastomosis, is the procedure of choice for annuloaortic ectasia because it reduces the risk of coronary artery-related complications. Concomitant total arch replacement may be recommended for annuloaortic ectasia with DeBakey type I aortic dissection in selected patients to avoid the risk of reoperation on the aortic arch.

Brain protection using antegrade selective cerebral perfusion: a multicenter study

BACKGROUND

To evaluate the results of antegrade selective cerebral perfusion as a method of brain protection during surgery of the thoracic aorta and to determine predictors of hospital mortality and adverse neurologic outcome.

METHODS

Between October 1995 and March 2002, 588 patients underwent aortic surgery with the aid of antegrade selective cerebral perfusion. There were 334 men (56.8%); the mean age was 63.7 +/- 11.8 years. One hundred sixty-two patients (27.6%) underwent urgent operation. The separated graft technique was employed to reimplant the arch vessels in 230 patients (65.3%) of the 352 requiring aortic arch replacement. Associated procedures were performed in 254 patients (43.2%). One hundred twelve patients underwent elephant trunk procedure. The mean cerebral perfusion time was 67 +/- 37 minutes.

RESULTS

The overall hospital mortality rate was 8.7%. A logistic regression analysis revealed urgent operation, recent central neurologic event, tamponade, unplanned coronary artery revascularization and pump time to be independent predictors of hospital mortality (p < 0.05). The permanent neurologic dysfunction rate was 3.8%. A logistic regression analysis showed tamponade to be independent predictor of permanent neurologic dysfunction (p < 0.05). The transient neurologic dysfunction rate was 5.6%. Recent central neurologic event, tamponade, coronary disease, and aortic valve replacement were indicated as independent predictors of transient neurologic dysfunction by logistic regression (p < 0.05).

CONCLUSIONS

In our experience the utilization of antegrade selective cerebral perfusion resulted in encouraging results in terms of hospital mortality and brain complications. Neither the extent of the replacement nor the duration of the cerebral perfusion had an impact on hospital mortality and neurologic outcome.

Deep hypothermic circulatory arrest and antegrade selective cerebral perfusion during ascending aorta-hemiarch replacement: a retrospective comparative study

OBJECTIVE

We sought to compare the results of ascending aorta-hemiarch replacement by using 2 different methods of cerebral protection in terms of hospital mortality, neurologic outcome, and systemic morbidity and to determine predictive risk factors associated with hospital mortality and neurologic outcome after ascending aorta-hemiarch replacement.

METHODS

Between January 1995 and September 2001, 289 patients (mean age, 62.2 +/- 13.2 years; urgent status, 122/289 [42.2%]) underwent ascending aorta-hemiarch replacement with the aid of antegrade selective cerebral perfusion (161 patients) or deep hypothermic circulatory arrest (128 patients).

RESULTS

Overall hospital mortality was 11.4% (deep hypothermic circulatory arrest group, 13.3%; antegrade selective cerebral perfusion group, 9.9%; P =.375). A logistic regression analysis revealed acute type A dissection (P =.001; odds ratio, 4.3) and age of greater than 70 years (P =.019; odds ratio, 2.5) to be independent predictors of hospital mortality. The permanent neurologic dysfunction rate was 9.3% (deep hypothermic circulatory arrest group, 12.5%; antegrade selective cerebral perfusion group, 7.6%; P =.075). Logistic regression analysis revealed acute type A dissection (P =.001; odds ratio, 6.7) and history of cerebral infarction-transient ischemic attack (P =.038; odds ratio, 3.4) to be independent predictors of permanent neurologic dysfunction. The transient neurologic dysfunction rate was 8.0% (deep hypothermic circulatory arrest group, 7.1%; antegrade selective cerebral perfusion group, 8.7%; P =.530). Acute type A dissection (P =.001; odds ratio, 5.1) was indicated as an independent predictor of transient neurologic dysfunction by means of logistic regression. Renal dysfunction (postoperative creatinine level of >250 micromol/L; deep hypothermic circulatory arrest, 10 [7.8%]; antegrade selective cerebral perfusion, 6 [3.7%]; P =.030), as well as prolonged intubation time (deep hypothermic circulatory arrest, 3.8 +/- 6.3 days; antegrade selective cerebral perfusion, 2.2 +/- 2.5 days; P =.005) were more common in the deep hypothermic circulatory arrest group.

CONCLUSION

The use of antegrade selective cerebral perfusion and deep hypothermic circulatory arrest during ascending aorta-hemiarch replacement resulted in acceptable hospital mortality and neurologic outcome. Reduced postoperative intubation time and better renal function preservation were observed in the antegrade selective cerebral perfusion group.

Surgery for acute type A dissection using antegrade selective cerebral perfusion: experience with 122 patients

BACKGROUND

Antegrade selective cerebral perfusion (ASCP) has proved to be a reliable method of brain protection during surgery of the thoracic aorta, but its use during aortic dissection surgery still remains controversial. In this study, we present our results after the operative repair of acute type A aortic dissections using ASCP and moderate hypothermic circulatory arrest.

METHODS

Between October 1995 and August 2001, 122 patients (76 men, 46 women) underwent repair of acute type A aortic dissection with the aid of ASCP and open distal anastomosis. The average age of the patients was 61 +/- 12 (mean +/- standard deviation). Preoperative complications included cardiac tamponade (n = 34; 27.0%), aortic regurgitation (n = 27; 22.1%), and new neurological deficits (n = 11; 9%).

RESULTS

Stepwise logistic regression revealed preoperative cardiac tamponade (p = 0.018) and new neurological deficits (p = 0.017) to be independent determinants for hospital mortality (19.7%). Permanent neurological complications occurred in 7% of the patients. Independent risk factors for temporary neurological dysfunction (11.2%) included cardiac tamponade (p = 0.019) and preoperative neurological deficits (p = 0.000).

CONCLUSIONS

In our experience, the surgical treatment of acute type A aortic dissection with the aid of ASCP was associated with acceptable hospital mortality and neurologic morbidity rates.

Antegrade selective cerebral perfusion during operations on the thoracic aorta: factors influencing survival and neurologic outcome in 413 patients

OBJECTIVE

We retrospectively analyzed hospital mortality and neurologic outcome after operations on the thoracic aorta with the aid of antegrade selective cerebral perfusion to determine a predictive risk model.

METHODS

Between October 1995 and May 2001, 413 patients (mean age, 63.0 +/- 11.5 years) underwent operations on the thoracic aorta with antegrade selective cerebral perfusion. Indications for surgical intervention were acute type A dissection in 116 (28.1%) patients, degenerative aneurysm in 227 (55.0%) patients, and postdissection aneurysm in 70 (16.9%) patients. One hundred twenty-five (30.3%) patients were operated on urgently; concomitant procedures were performed in 171 (41.4%) patients. Mean cerebral perfusion time was 63.0 +/- 38.7 minutes (range, 16-220 minutes). Preoperative and intraoperative factors were evaluated by means of univariate and multivariate analysis to identify predictors of hospital mortality and neurologic outcome.

RESULTS

The hospital mortality was 9.4%. Stepwise logistic regression revealed urgency status (P =.000; odds ratio, 19.9) and recent history of a recent central neurologic event (P =.004; odds ratio, 8.0) to be independent determinants for hospital mortality. Temporary neurologic dysfunction occurred in 20 (5.1%) patients. Urgency status (P =.005; odds ratio, 7.5), history of a central neurologic event (P =.003; odds ratio, 8.6), and coronary artery bypass grafting (P =.019; odds ratio, 6.0) were independent determinants of temporary neurologic dysfunction. Urgency status (P =.003; odds ratio, 8.6) was the only independent determinant for permanent neurologic dysfunction, and it occurred in 15 (3.7%) patients.

CONCLUSION

Antegrade selective cerebral perfusion is an effective method of brain protection. Cerebral perfusion times of longer than 90 minutes were not associated with an increased risk of hospital mortality or poorer neurologic outcome. Urgency status and recent history of central neurologic events were retained as important risk factors for hospital mortality and neurologic outcome.

Optimal arterial cannulation technique for selective cerebral perfusion in thoracic aortic surgery

Despite advances in surgical procedures, anesthetic management, and cardiopulmonary bypass, brain injury remains a major source of morbidity and mortality in patients undergoing operations on the thoracic aorta. Here, we report our experience with arch vessel cannulation for selective cerebral perfusion in 32 consecutive patients with thoracic aneurysms who underwent total arch replacement between 1998 and 2000. The innominate vein was divided, and intraoperative epiaortic echography was performed to identify the least atherosclerotic site on brachiocephalic and left carotid arteries before establishment of cardiopulmonary bypass. There were no in-hospital deaths, and only 1 patient (3.1%) had a perioperative stroke. Identifying the least atherosclerotic site in cephalic branches is important for safely establishing selective cerebral perfusion and for preventing perioperative cerebral embolism during total arch replacement.

Usefulness of antegrade selective cerebral perfusion during aortic arch operations

BACKGROUND

To evaluate the safety and usefulness of antegrade selective cerebral perfusion (SCP) during arch aneurysm or aortic dissection operations.

METHODS

Between January 1986 and December 2001, 330 patients underwent aortic arch repair using SCP. Operations were performed with the aid of hypothermic extracorporeal circulation, SCP, and systemic circulatory arrest in most cases. In all, 89 patients (27%) were operated on for acute aortic dissection, 77 (23%) for chronic aortic dissection, and 164 (50%) for degenerative aneurysm. Total arch replacement using a branched graft was performed in 288 patients (94%). Mean SCP time was 86.2 +/- 28.5 minutes.

RESULTS

The overall in-hospital mortality rate was 11.2% (falling to 3.2% in the 124 patients operated on between 1997 and 2001). Independent determinants of hospital mortality were pump time, renal/mesenteric ischemia, chronic renal failure, increasing age, period of operation, and nonuse of four-branched arch graft. The overall postoperative incidences of temporary and permanent neurologic dysfunction were 4.2% and 2.4%, respectively. There was no significant correlation between SCP time and in-hospital mortality or neurologic outcome.

CONCLUSIONS

Selective cerebral perfusion is a reliable technique for cerebral protection and it facilitates complex and time-consuming total arch replacement.

Aortic arch replacement using a trifurcated graft and selective cerebral antegrade perfusion

BACKGROUND

Aortic arch aneurysm repair remains associated with considerable mortality and risk of cerebral complications. We present results of a technique utilizing a three-branched graft for arch replacement, deep hypothermic circulatory arrest (HCA), and selective antegrade cerebral perfusion (SCP).

METHODS

Between March 2000 and November 2001, 22 patients (11 female) aged 40 to 77 years (mean 64 +/- 11.2) underwent arch replacement utilizing the trifurcated-graft technique. Serial anastomosis of the branched graft to individual cerebral vessels was carried out during HCA, followed by arch reconstruction during SCP through the graft. All 22 patients had surgery electively. Eight patients (36%) had undergone previous aortic surgery. In 19 patients, arch replacement was part of an elephant trunk procedure; 2 patients had Bentall operations and 1 had isolated arch replacement. Concomitant coronary artery bypass grafting was performed in 6 patients (27%). Mean HCA duration was 30 +/- 6 minutes at a mean temperature of 11.4 +/- 0.8 degrees C. Mean duration of SCP was 52 +/- 18 minutes.

RESULTS

Adverse outcome--death before hospital discharge or permanent stroke or both--occurred in 2 patients (9%). Two patients experienced transient neurologic dysfunction (9%). Two patients (9%) developed renal failure requiring short-term hemodialysis and pulmonary complications occurred in 2 patients.

CONCLUSIONS

Cerebral protection and prevention of atheroembolism remain challenges in aortic arch reconstruction. To reduce neurologic complications we developed an aortic arch reconstruction technique in which a trifurcated graft is anastomosed to the brachiocephalic vessels during HCA, reducing the risk of embolization while minimizing cerebral ischemia by permitting antegrade cerebral perfusion as arch repair is completed.

Open stent-grafting for aortic arch aneurysm is associated with increased risk of paraplegia

BACKGROUND

Open surgery using the endovascular stent-graft is a novel technique that lessens the invasiveness of surgery for the aortic arch. However, the outcome of this procedure remains uncertain.

METHODS

Between November 1996 and July 2000, a total of 19 patients underwent open surgery using an endovascular stent-graft for thoracic aortic aneurysms. There were 15 men (78.9%) and 4 women (21.1%). Patient age ranged from 29 to 82 years (mean 69.3 years, median 74 years). Atherosclerotic thoracic aortic aneurysms were present in 17 patients (89.4%) and aortic dissection in 2 patients (10.5%).

RESULTS

Two patients (10.5%) died in the hospital and 4 patients (21.1%) presented with paraplegia postoperatively. Among the 4 patients with postoperative paraplegia, 1 case was complicated with intraoperative aortic dissection. The other 3 patients with paraplegia had spinal cord ischemic time of more than 60 minutes and intraoperative body weight gain of more than 4 kg. Of these 3 patients, hemodynamic instability after cardiopulmonary bypass was observed in 1 patient and cholesterin embolus in the anterior spinal artery was found at autopsy in another. On univariate analysis, age greater than 75 years was the only risk factor associated with paraplegia (p < 0.05). Autopsy findings for the 2 patients showed that the Adamkiewicz arteries were not blocked by the stent-graft in either patient.

CONCLUSIONS

Intraoperative aortic dissection, embolization of the intercostal arteries, long ischemic time of the spinal cord, and excessive weight gain during operation may have been associated with the high incidence of paraplegia after open surgery using the endovascular stent-graft.

Aortic arch resection under temporary bypass grafting for advanced thymic cancer

Extensive surgery for malignant disease requiring cardiopulmonary bypass may cause postoperative immunosuppression. We conducted resection of the aortic arch and total arch replacement under temporary bypass grafting in a patient with advanced thymic cancer invading the aortic arch. No major postoperative complications such as brain damage or paraplegia occurred. Temporary bypass grafting is thus applicable in extensive surgery for malignant disease invading the aortic arch.

Neurological Complications of Aortic Surgery

Surgery of the aortic arch involves an inherently high risk of neurological complications. A number of factors have been identified which may predispose the patient to brain injury, and various techniques employed in an attempt to counteract these are outlined. In particular the vulnerability of the brain to ischemia has led to the development of three adjunctive cerebral protective techniques, hypothermic circulatory arrest, retrograde cerebral perfusion and selective antegrade cerebral perfusion, all based upon brain cooling and metabolic inhibition. The relative merits and disadvantages of these techniques are therefore discussed. Finally, pharmacologic adjuncts and potential future developments in aortic arch surgery are discussed.

Simulation study of a selective cerebral perfusion system with a single centrifugal pump

We previously successfully developed a simple nonroller extracorporeal circulation system (NRECC). In aortic arch surgery, more than two pumps are generally used for systemic perfusion and selective cerebral perfusion (SCP); we developed a new pressure-dependent perfusion system for SCP based on our NRECC and operated by a single centrifugal pump. The cerebral perfusion line was branched from the main perfusion line, and one 15 French and two 12 French cannulae were used for SCP. The perfusion pressure was regulated with a tube occluder. Afterload was changed from 30 to 80 mm Hg, the pressure of the SCP line was increased from 80 to 200 mm Hg, and flow volume was measured. When the afterload was set at 50 mm Hg, according to the increase of perfusion from 80 to 200 mm Hg, the flow volume of the 15 French cannula increased from 280 to 950 ml/min. Under the same conditions, flow volume of the 12 French cannula increased from 160 to 560 ml/min. Sufficient flow volume of the SCP lines was obtained when the SCP line pressure was over 80 mm Hg. As a result of the increased perfusion pressure, the flow volume showed a direct increase. These findings suggest that aortic arch surgery is possible using this SCP system.

Isolation technique for stroke prevention in patients with a mobile atheroma

Mobile atheroma in the proximal aorta is a risk factor for brain complication after cardiovascular operation. We report a new technique of replacing the ascending and transverse aorta by establishing selective hypothermic antegrade cerebral perfusion. After cooling, cerebral vessels are clamped and systemic perfusion is started. This technique was applied in 5 patients. All patients woke up normally and recovered without neurologic complication.

Experimental study on the effect of antegrade cerebral perfusion on brains with old cerebral infarction

OBJECTIVE

Patients with old cerebral infarction who undergo aortic arch operations are susceptible to postoperative neurologic dysfunction. To verify such susceptibility, we performed this experimental study.

METHODS

A cerebral infarct model was created in mongrel dogs by means of injection of cylindrical silicone embolus through the internal carotid artery. The dogs that had obvious neurologic deficits 1 day later and survived for 4 weeks or more were included in the cerebral infarct model. One month after cerebral infarction was induced, deep hypothermia and selective cerebral perfusion were used in 14 mongrel dogs (infarct group, n = 7; control group, n = 7). During this procedure, serum glutamate concentration and venous-arterial lactate difference were measured. Histopathologic study of the brain was also performed.

RESULTS

Changes in venous-arterial lactate difference in both groups were almost similar, except in the rewarming phase. At 32 degrees C during rewarming, the venous-arterial lactate difference in the infarct group was significantly higher than that in the control group (P =.006). Although pre-cooling concentrations of serum glutamate were similar in both groups, the values in the infarct group at the end of rewarming were significantly higher than those in the control group (P =.046). On histologic examination, the presence of old cerebral infarction with gliosis was confirmed in the infarct group, but neither new cerebral infarction nor destruction of the blood-brain barrier was found.

CONCLUSION

We observed an accelerated anaerobic metabolism and an increased extracellular glutamate release in the infarct group. The brain with old cerebral infarction is more susceptible to ischemia during arch operation than noninfarcted brain.

New cerebral monitoring using optical topography during total arch replacement

We investigated the levels of oxygenation in the extended cerebral regions, including the middle cerebral artery region, using optical topography in two patients who underwent total arch replacement assisted by selective cerebral perfusion. During the cooling phase, the oxyhemoglobin levels were almost homogenous. During selective cerebral perfusion, when 18 French and 16 French cannulae were used for the innominate and the left common carotid artery respectively, the oxyhemoglobin levels in the left hemisphere were consistently greater than those in the right. After the 16 French cannula was replaced with a 14 French in the left common carotid artery, then no difference between the hemispheres was found. During the rewarming phase, the increase in the oxyhemoglobin levels in the parietal region was consistently more delayed than that in the temporal region, in both patients. Optical topography might be useful for more precise monitoring of the cerebral circulatory status during an aortic arch operation.