Axillary artery cannulation: routine use in ascending aorta and aortic arch replacement

When Should the Aortic Arch Be Replaced in Marfan Patients?

BACKGROUND

The purpose of this study was to assess the prevalence, indications, and results of aortic arch replacement in Marfan patients with and without acute dissection.

METHODS

Between January 1993 and December 2005, our group performed 76 aortic replacements in 54 Marfan patients (mean age, 38.3 years), of whom 20 had already undergone one or two replacements of the thoracic aorta, and 3 required one late procedure each in other institutions. So, the 54 patients underwent a total of 100 aortic operations. Indication for initial surgery was elective aortic root replacement in 25 patients (46%), acute type A dissection in 19 (35%), acute type B dissection in 2 (4%), and chronic type B dissection in 8 (15%). Indication for reoperation was residual chronic dissection in the proximal aorta in 14 patients (36%), in the distal aorta in 22 (56%), and acute retrograde type A dissection in 3 (8%).

RESULTS

At initial operation, the aortic arch was not involved in the 25 patients with aneurysm of the aortic root and was replaced in only 1 of the 19 patients with acute type A dissection (1/44 patients, 2.3%). At the second or third operation, the arch had to be replaced in 4 (16%) of 25 patients initially operated on for aortic root aneurysm, in 14 (73%) of 19 patients operated on for acute type A dissection, and in 3 (30%) of 10 patients with previous acute or chronic type B dissection. The difference between patients with initial elective aortic root replacement and patients with acute dissection was highly significant (p < 0.001). Overall in-hospital mortality was 13%. The risk of death was 9.6% per procedure.

CONCLUSIONS

Aortic arch replacement in Marfan patients is not indicated during elective aortic root replacement. In contrast, the significant rate of aneurysmal dilatation of the aortic arch after surgery for acute type A dissection may be an incentive for a more aggressive approach toward the aortic arch during initial surgery.

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.

Carotid artery cannulation in aortic surgery

OBJECTIVE

Carotid artery cannulation was initially established at our clinic for surgery of acute aortic dissection, and it became the standard approach for procedures in which circulatory arrest is necessary. The aim of the study was to evaluate this method's efficiency regarding postoperative outcomes after the first 100 procedures.

METHODS

Between July 2002 and October 2005, 100 patients underwent aortic surgery using carotid artery cannulation by a side graft for arterial return with a mean flow rate of 4.6 +/- 0.5 L/min. There were 27 patients with acute and 2 with chronic type A aortic dissection. Sixteen patients had had prior cardiac surgery. During circulatory arrest, the arterial line was used for unilateral cerebral perfusion in moderate hypothermia (mean rectal temperature 28 degrees C +/- 1.6 degrees C) with a mean flow rate of 0.85 +/- 0.2 L/min.

RESULTS

Carotid artery cannulation offered adequate arterial return in all patients. In no case was a switch to another cannulation site necessary for arterial return. Furthermore, no complications related to the cannulation site were observed. One patient with acute dissection and 1 with chronic aneurysm died during the early postoperative course. Thus, 30-day mortality was 2.0% for the whole group and 3.7% for the dissection group. Two patients with severe calcification of the aortic valve had strokes. There were no strokes in the dissection group, although there were preoperative signs of cerebral malperfusion in 4 patients.

CONCLUSIONS

Carotid artery cannulation is a fast, safe, and efficient method of arterial cannulation even in very obese patients. In addition, it simplifies the procedure of unilateral cerebral perfusion through the arterial line during circulatory arrest, making it completely unnecessary to interrupt cerebral perfusion.

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.

Repair of thoracic aneurysms, with special emphasis on the preoperative work-up

The anesthetic approach to the patient with a thoracic aortic aneurysm depends on the urgency of repair. Symptomatic patients with leaking aneurysms require urgent intervention, and there is generally little time to perform more than the most basic preoperative assessment. For elective repair, however, one must consider nearly every organ system. Many of the specific issues are inherent to the underlying pathophysiology that has resulted in aneurysm formation, and some stem from the requirements of the surgical procedure itself. A thorough knowledge of the extent and location of the aneurysm, the functional status of the heart, and the coronary artery anatomy are critical. Most patients aged older than 40 years undergo coronary angiography preoperatively, as do younger patients with specific risk factors for myocardial ischemia. Respiratory failure is one of the most common sequelae of these procedures, and a thorough preoperative pulmonary work-up is mandatory. Neurologic deficits are not uncommon postoperatively, and pre-existing deficits in the central nervous system must be sought. Coagulopathy is common in the immediate postoperative period, and preoperative assurance of hemostatic competence is important. Computed tomography scans and magnetic resonance imaging are the mainstay of diagnosis, although the adjunctive use of echocardiography provides important information. Routine preoperative laboratory studies include complete blood count, chemistries, coagulation profile, and indices of renal function; an electrocardiogram, and chest radiograph. Close communication with the surgeon regarding the operative procedure, cannulation strategy (where applicable), and planned evoked potential monitoring is necessary to ensure appropriate perioperative management. Prophylactic antibiotics and antifibrinolytics are routine.

Surgical outcome of aortic arch repair for patients with Takayasu arteritis

BACKGROUND

Takayasu arteritis can cause segmental dilatation or stenosis of the aorta and its major branches, and surgical treatment of it is still difficult. Our objective was to review late results of aortic arch repair for patients with Takayasu arteritis.

METHODS

Between 1987 and 2003, 21 patients underwent aortic arch repair under circulatory arrest. Diagnosis was performed by pathologic study of specimens for all patients. Total aortic arch repair was performed in 12 patients with separated branched grafts and in 2 patients with the island technique. Selective cerebral perfusion was used in 12 patients and retrograde cerebral perfusion in 2 patients in this type of surgery. Hemiarch replacement using retrograde cerebral perfusion was performed in 7 patients. Craniocervical vascular stenosis was found in 7 patients and aneurysm in 5 patients. The elephant trunk technique was used in 10 patients. The follow-up period was 6.2 +/- 4.2 years.

RESULTS

There was one hospital death due to renal failure, and two late deaths, both of which were sudden. Late in follow-up, a patient who had undergone hemiarch replacement 12 years previously required total aortic arch repair for dilatation of the distal arch. Three patients required thoracoabdominal aortic repair and one patient descending aortic repair for residual aortic dilatation late in follow-up. Postoperative spinal infarction occurred in one patient who underwent hemiarch replacement.

CONCLUSIONS

Surgical and late outcomes of aortic arch repair under circulatory arrest appear favorable, though late dilatation of the residual aorta is a matter of concern.

Extended Applications of Thoracic Aortic Stent Grafts

BACKGROUND

Thoracic stent-grafts (TSG) show excellent early and mid-term results for localized diseases of the descending aorta. Extending TSG applications for arch pathologies or to other yet unproven indications remains to be established. We herein report our experience in 18 patients with extended applications of TSG.

METHODS

Ten patients with inadequate proximal aortic neck length required coverage of at least one arch vessel with or without extra-anatomic bypass. One patient required an extra-anatomic visceral bypass to extend the distal aortic neck, 6 patients were treated with TSG for yet unproven indications, and 1 patient required an unusual vascular access.

RESULTS

A mean of 2.4 +/- 1.0 stents per patient were inserted. Primary or secondary success rate was 100%. Hospital mortality occurred in one patient (5.5%). Mean follow-up was 24.1 +/- 13.7 months. Four endoleaks were diagnosed: two of type 1, one of type 2, and one that remains undetermined. Two patients died during follow-up; both deaths were linked to the presence of a type 1 endoleak. Actuarial survival at 3 years was 79.0%. Freedom from endoleak and stent-graft-related death at 3 years were, respectively, 71.0% and 83.7%. No stent-graft migration was observed.

CONCLUSIONS

Early and mid-term results of extended applications of TSG are acceptable in well-selected high-risk patients. Endoleak at follow-up remains a concern and may impede long-term outcome of TSG in complex procedures.

Perfusion Pressure Does Not Affect Neurologic Outcome in Axillary Artery Side Graft Cannulation in Type A Aortic Dissection

OBJECTIVE

Antegrade selective cerebral perfusion (ASCP) through the right axillary is a safe and effective method for cerebral protection in aortic surgery. In the present study, we evaluated whether or not pressure control in ASCP affected the neurologic outcome.

METHOD

Sixty-two patients (17 female, 45 male) with a mean age of 53.9 +/- 9.4 years (range, 23-74 years) with a diagnosis of Type A aortic dissection were operated on by using the right axillary artery side graft cannulation technique. ASCP with pressure control was used in the first 37 (59.6%) patients (group 1), whereas ASCP with flow control was used in the consecutive 25 patients (39.4%) (group 2). The groups were compared according to postoperative neurologic outcomes.

RESULTS

The hospital mortality rate was 9.7% with 6 patients. The mean ASCP flows of group 1 was 663 +/- 76 mL/min and 692 +/- 51 mL/min in group 2. This difference was not statistically significant (P = .120). The neurological dysfunction rates were 2.7% in group 1 with 1 patient and 8% in group 2 with 2 patients (P = .560).

CONCLUSION

In this study, we could not find a statistically significant difference in patients treated with ASCP through the right axillary applicated with pressure control versus flow control.

Spectrum of Aortic Operations in 300 Patients With Confirmed or Suspected Marfan Syndrome

BACKGROUND

Cardiovascular disease is the main cause of morbidity and mortality in patients with Marfan syndrome. Many patients with presumed Marfan syndrome do not meet current diagnostic criteria. This study reviews the surgical aspects of aortic disease in 300 patients referred with the diagnosis of Marfan syndrome.

METHODS

During a 16-year period, 300 patients with presumed Marfan syndrome underwent 398 operations on the aorta and branch arteries, including 125 aortic root operations, 59 aortic arch repairs, 31 descending thoracic aortic repairs, and 178 thoracoabdominal aortic repairs. Based on medical record review, patients were classified as confirmed Marfan syndrome if documented features satisfied current diagnostic criteria; patients not meeting these criteria were classified as suspected Marfan syndrome.

RESULTS

There were 17 operative deaths (4.3%) after the 398 operations. Survival after the initial referral operation was 96.2% +/- 1.5% at 1 year, 82.7% +/- 2.4% at 5 years, and 74.6% +/- 3.1% at 10 years. Presentations, operative details, and outcomes were remarkably similar in the 137 patients (45.7%) with confirmed Marfan syndrome and the 163 patients (54.3%) with suspected Marfan syndrome. Freedom from repair failure, however, was significantly better in patients with confirmed Marfan syndrome (90.3% +/- 2.3% at 10 years) than in those with suspected Marfan syndrome (82.0% +/- 3.1% at 10 years; p = 0.001).

CONCLUSIONS

Operative treatment of the full spectrum of aortic disease in Marfan patients enables excellent long-term survival. Similarities in surgical aspects of aortic disease suggest that patients with features of Marfan syndrome who do not meet diagnostic criteria should be managed in the same manner as patients with confirmed Marfan syndrome.

Antegrade Cerebral Perfusion With a Simplified Technique: Unilateral Versus Bilateral Perfusion

BACKGROUND

Selective antegrade cerebral perfusion has been introduced as a strategy of cerebral protection in operations on the aortic arch with hypothermic circulatory arrest. Several techniques of unilateral and bilateral cerebral perfusion have been described with varying results.

METHODS

Patients underwent either unilateral cerebral perfusion with a cannula in the right subclavian artery or bilateral cerebral perfusion, with an additional cannula in the left carotid artery. A simplified Seldinger-type technique for subclavian artery cannulation was employed. Results were analyzed with multivariable logistic regression analysis and propensity score analysis to adjust for nonrandomized treatment assignment.

RESULTS

Of 65 patients, 17 (26%) had unilateral cerebral perfusion. Mortality was 11% (n = 7); 14% (n = 9) had a stroke. In multivariable analysis, unilateral cerebral perfusion was significantly associated with stroke (odds ratio 6.6 [1.2 to 36]). Age more than 70 years was associated with in-hospital death (odds ratio 12 [1.3 to 113]), and concomitant coronary artery bypass graft surgery was associated with adverse outcome (odds ratio 23 [1.8 to 299]). Balancing variables in a propensity score analysis, stroke remained significantly more common with unilateral brain perfusion (29% versus 0%, p = 0.045). Complications associated with subclavian artery cannulation were encountered in 1 patient (1.5%).

CONCLUSIONS

The described cannulation technique is safe and effective. Bilateral cerebral perfusion is easily achieved and is associated with decreased stroke risk, and should be the preferred brain protection strategy.

Anterolateral thoracotomy for distal aortic arch disease

PURPOSE

Optimal exposure and antegrade arterial perfusion are keys to avoiding complications in the repair of distal aortic arch disease. To achieve these ends, we performed distal aortic arch repair through a left anterolateral thoracotomy while also using axillary artery perfusion.

METHODS

From Mach 1998 to December 2004, 28 patients (23 men and 5 women, age 65.2 +/- 12.0 years) underwent a distal aortic arch repair through a left anterolateral thoracotomy. All cases had atherosclerotic aneurysms. Emergency surgery was performed in 1 of these cases (1/28, 3.6%) with an aortic rupture. The right axillary artery was used for arterial perfusion in all cases.

RESULTS

No perfusion problems occurred during surgery, and the left anterolateral thoracotomy approach provided an excellent view of both the aortic arch and descending aorta. There was no hospital mortality. Morbidity included one incident of transient convulsion without computed tomographic evidence of an embolism and one incident of heart failure that required temporary mechanical support. No other significant event or morbidity occurred related to the surgical methods. There was no late death during the 1 to 81-month follow-up.

CONCLUSION

A left anterolateral thoractomy provides an ideal view of distal aortic arch disease, and antegrade arterial perfusion is effective in the prevention of retrograde embolism. These results suggest this treatment modality to be a reliable alternative approach for the repair of distal aortic arch disease.

Anesthesia and Neurocerebral Monitoring for Aortic Dissection

Patients presenting to the operating room for repair of aortic dissection are challenging in all aspects of their care. Without exception, they require a multidisciplinary team approach. This article will review some of the specific challenges faced by anesthesiologists and neurologists when confronted with such a diagnosis. Specifically, we will discuss the myriad anesthetic issues that present in the preoperative stage and continue into the postoperative period. Neurologic complications during dissection repair result in increased morbidity and mortality. A variety of neurophysiologic monitoring techniques exist that may reduce this risk and will be discussed in detail. Finally, we will present some "controversies in care," emphasizing that our respective fields continue to grow, learn, and improve what information we have on the morbidity and mortality of aortic dissection.

Operative Management of Ascending Aortic Dissections

Surgical management has been the established standard of care for acute ascending aortic dissection (Stanford type A or Debakey type I or II) with a worldwide average operative mortality rate of 23% compared with a 1-month mortality rate of 60% with medical management alone. Improving an institution's operative results depends on the establishment of a comprehensive and specialized team integrating their expertise into a protocol-driven system of care delivery specific for aortic dissections. The operative strategies and techniques for repairing aortic dissections should also be standardized within an institution to optimize outcomes. The primary goals of operative repair of ascending aortic dissection are to restore aortic valvular competency and systemic perfusion, to obliterate false-lumen blood flow, and to prevent rupture, myocardial infarction, stroke, and death. The goals, strategies, and expected outcomes for the operative management of acute ascending aortic dissection are presented.

Time and Risk Analysis for Acute Type A Aortic Dissection Surgery Performed by Hypothermic Circulatory Arrest, Cerebral Perfusion, and Open Distal Aortic Anastomosis

BACKGROUND

Hypothermic total circulatory arrest, retrograde or antegrade cerebral perfusion, and open distal anastomosis are important stages of surgical management and cerebral protection for acute type A dissections. Among the factors that influence survival are the transfer time to hospital from the onset of symptoms, in-hospital transfer time to operation, organ malperfusion, preoperative risk factors, and intraoperative variables. The aim of this study was to analyze time and risk factors during surgical management.

METHODS

Between September 1996 and March 2002, a total of 26 patients with acute type A aortic dissection were operated. Sixteen patients (61.5%) were male and mean age was 49 ( 13.1 years (range: 26-68). The diagnosis was based on clinical examination, telecardiography, transthoracic echocardiography, computerized tomography, and angiography. Hypothermic total circulatory arrest, retrograde or antegrade cerebral perfusion and open distal anastomosis were used during the procedures. Operative techniques were as follows: supracoronary ascending aortic replacement (17 patients), aortic root and ascending aortic replacement with flanged composite grafting technique (5 patients), replacement of ascending aorta and hemiarcus (1 patient), aortic root and ascending aortic replacement with modified Bentall technique (1 patient), replacement of ascending aorta and arcus (1 patient), and total arcus replacement with elephant trunk technique and modified Bentall procedure (1 patient).

RESULTS

The early postoperative mortality rate within the first 30 days was 26.9%, and the late postoperative mortality rate was 15.8%. Two patients (7.7%) developed major neurological complications during the postoperative period. Time to admission, durations of total circulatory arrest, cross-clamp, cardiopulmonary bypass, and intubation were longer, and postoperative blood loss was greater in patients who died during early postoperative period, although the differences did not reach statistical significance. Duration of total circulatory arrest was longer in patients who developed neurological dysfunction compared to patients without this complication; this difference also did not reach statistical significance.

CONCLUSIONS

Total circulatory arrest, cerebral perfusion, and open distal anastomosis are reliable options in the surgical management of acute type A aortic dissections. With open distal anastomosis aortic arcus can be evaluated, distal anastomosis can be performed more easily, and postoperative neurological recovery is hastened. In the present study, although statistical significance could not be reached due to limited sample size, the time to admission, durations of total circulatory arrest, cross-clamp, and cardiopulmonary bypass, and the amount of postoperative chest output seem to influence postoperative survival.

Femoral Versus Aortic Cannulation for Surgery of Chronic Ascending Aortic Aneurysm

BACKGROUND

Femoral artery cannulation and retrograde arterial perfusion have been postulated to increase the risk of cerebral embolism. In this study, the impact of the arterial cannulation site on the perioperative results after proximal aortic surgery is evaluated.

METHODS

Between January 1996 and December 2002, a total of 327 patients underwent proximal aortic repair for chronic non-dissected aortic disease. The arterial inflow was established by cannulation of the aortic arch (group A) or the femoral artery (group F) in 166 and 161 patients, respectively.

RESULTS

The early 30-day mortality was 0.9% (3 patients [1 patient in group A and 2 patients in group F]). The overall rate of early focal neurologic dysfunction (permanent and transient) was 4% (13 patients) and there was no significant difference between the two groups (4.2% vs 3.7%). Due to an intraoperative injury of the arterial wall, there were 6 repairs (3.6%) of the aortic arch in group A and 1 repair (0.6%) of the femoral artery in group F. The univariable examination of preoperative and intraoperative variables demonstrated that hypertension and increased cholesterol level could be possible independent risk factors for neurologic morbidity. In the following stepwise logistic regression, only the preoperative hypercholesterolemia was identified as an independent predictor for postoperative focal neurologic dysfunction.

CONCLUSIONS

The arterial inflow via the femoral artery and the subsequent retrograde perfusion during cardiopulmonary bypass do not increase the risk of neurologic complications in patients who undergo proximal aortic repair due to chronic non-dissected aortic aneurysm. Because there is an increased risk of aortic wall injury during cannulation, the femoral artery seems to be more suitable in these cases for cannulation than the proximal aorta.

Transcutaneous Axillary Artery Cannulation

The axillary artery may be an alternative cannulation site for patients with diffused atherosclerosis, aortic dissection, and aneurysm. There are different techniques for axillary artery cannulation that can be performed easily with a transcutaneous approach. Small incision necessity, less dissection, and good wound healing are other advantages of this technique.