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Owing to the increased use of the axillary artery for arterial inflow during cardiopulmonary bypass, patients with previous cannulation at this site who require reoperation will be encountered more and more frequently. We describe the cases of 2 patients who required recannulation of the axillary artery for complex reoperations of the thoracic aorta. The technique and pitfalls are described.
The decision was made to reuse the previous cannulation site at the right axillary artery due to the presence of large pseudoaneurysms in proximity to the sternum. The old 8-mm Dacron stump was found and excised, and a new 8-mm Dacron graft was sutured to the right axillary artery for arterial inflow. In the 1st patient, the Dacron side-graft enabled insertion and subsequent inflation of an EndoClamp® within the Dacron graft of the ascending aorta, which obviated profound hypothermia. In the 2nd patient, recannulation of the right axillary artery enabled us to open the sternum at low flow using moderate hypothermia, given that antegrade cerebral perfusion was easily accessible in the event of a more prolonged arrest time. Both patients recovered fully, without neurovascular complications secondary to the recannulation of the right axillary.
Recannulation of the right axillary artery is safe during complex reoperation of the thoracic aorta. It avoids retrograde perfusion in the often-diseased descending thoracic aorta. Furthermore, sternal reentry may be performed under moderate hypothermia, because antegrade cerebral perfusion can be initiated with ease.
The ascending aorta is the standard arterial cannulation site for cardiopulmonary bypass (CPB) initiation during cardiac surgery procedures. Alternative sites for arterial cannulation include the transverse arch, and the innominate, iliac, and femoral arteries. Recently, the axillary artery has gained popularity as a cannulation site, especially for complex aortic procedures.
Direct axillary artery cannulation in cardiac surgery, first described by Villard and coworkers in 1976,1 has been shown to be a safe and reproducible way to initiate CPB.2,3 However, recannulation of the axillary artery for reoperation has yet to be described. We report our experience with the re-use of the axillary artery as a cannulation site in 2 patients undergoing repeat aortic surgery. The technique, its indications, and its pitfalls are discussed.
In December 2003, a 70-year-old woman with a history of hypertension and atrial fibrillation underwent an uneventful replacement of the aortic root with a 27-mm Freestyle® Aortic Root Bioprosthesis (Medtronic, Inc.; Minneapolis, Minn) and replacement of the ascending aorta and hemiarch with a Dacron graft, under circulatory arrest. An 8-mm Dacron graft was sutured to the right axillary artery as an inflow for CPB. Ten months after surgery, the patient was asymptomatic. However, a routine chest computed tomographic (CT) scan showed a 10-cm pseudoaneurysm arising from the ascending aorta. Angiography localized the leak between the distal portion of the Freestyle aortic root prosthesis and the Dacron graft (Fig. 1).
The proximity of the pseudoaneurysm to the sternum mandated the institution of CPB with profound hypothermia before sternal opening. To avoid profound hypothermia and circulatory arrest, we designed a modified technique using the Heartport® Port-Access® technology (CardioVations, a division of Ethicon, Inc., a Johnson & Johnson company; Somerville, NJ). Arterial inflow was obtained through a Y-branched arterial cannula (CardioVations) inserted within a new 8-mm graft sutured to the re-exposed right axillary artery (Fig. 2). Arterial perfusion (mean flow, 2.2 L/min/m2) was conducted through 1 branch of the arterial cannula. Venous inflow was performed by inserting a venous cannula through the femoral vein. In order to clamp the aorta above the pseudoaneurysm and induce cardiac arrest, we inserted an EndoClamp® (CardioVations) in the other branch of the arterial cannula (Fig. 2). Once positioned within the Dacron graft, the EndoClamp was inflated and the heart arrested by infusing blood cardioplegic solution through the cardioplegic port of the EndoClamp. Subsequently, we reentered the sternum, opened the pseudoaneurysm, and inserted an interposition graft between the Freestyle aortic root graft and the ascending aortic Dacron graft (Fig. 3).
Total CPB time was 88 minutes, with an EndoClamp inflation time (cross-clamp time) of 52 minutes; the lowest systemic temperature was 30°C. The patient had an uneventful postoperative course and was discharged on the 7th postoperative day. Chest CT scans performed 3 and 12 months later were normal.
In January 2004, a 56-year-old man underwent a tubular graft replacement of the ascending aorta for a type A dissection; for arterial cannulation, an 8-mm graft was sutured end-to-side to the right axillary artery. Six months postoperatively, a routine CT examination showed a pseudoaneurysm (Fig. 4). The origin of the leak, by angiography, was the proximal aortic anastomosis (Fig. 5). The proximity of the pseudoaneurysm to the sternum mandated peripheral CPB with profound hypothermia. Cardiopulmonary bypass was instituted by re-exposing the right axillary artery and suturing a new 8-mm graft for arterial inflow; a venous cannula was inserted in the right common femoral vein for venous inflow. The patient was cooled to 24°C, and the sternum was reopened under low-flow CPB. The aortic root was reconstructed by use of a modified valve-sparing procedure. Cross-clamp and CPB times were 53 and 152 minutes, respectively. The postoperative stay was uneventful, and chest CT scans performed 3 and 12 months postoperatively were normal.
The axillary artery is recognized as an excellent site to initiate arterial inflow for CPB. Studies that evaluate the outcome of axillary artery cannulation show low operative mortality and morbidity rates.4,5 The axillary artery is especially useful in circumstances such as type A dissection, high-grade atherosclerosis of the ascending aorta and arch, and complex aortic procedures and in the presence of a porcelain aorta.
Not only does axillary artery perfusion minimize the risks of embolic complications related to femoral perfusion when the ascending aorta is unavailable for cannulation, it facilitates the initiation of antegrade cerebral perfusion. Moreover, local neurovascular and infectious complications remain low—less than 5% in all series.6,7 Two methods for axillary artery cannulation have been described: direct cannulation and the interposition of a side graft. Both techniques have been shown to be reliable and safe.4,8 Both patients in the present series were cannulated by the side-graft technique, and a residual graft stump was left after discontinuation of CPB.
Because of the increased use of the axillary artery for cannulation, patients with previous cannulation at this site who require reoperation will be encountered more and more frequently. The present report describes the cases of 2 patients who had undergone axillary artery cannulation for complex aortic surgery and who presented later with complications related to that surgery. In both cases, the size of the pseudoaneurysm precluded a safe sternal reentry, unless deep hypothermia was induced by peripheral CPB cannulation. The decision was made to reuse the previous cannulation site at the right axillary artery. In the 1st patient, the side-graft technique enabled insertion of the EndoClamp, which made profound hypothermia unnecessary. In the 2nd patient, recannulation of the right axillary artery allowed us to open the sternum at low CPB flow using moderate hypothermia, since antegrade cerebral perfusion was easily accessible in the event of a more prolonged arrest time.
Re-dissection of the axillary artery should be performed meticulously and with minimal use of the cautery, to avoid neurologic injuries. The first objective of the dissection should be identification of the graft stump, which was easily accomplished in both of our patients. Subsequently, the axillary artery must be mobilized proximal and distal to the stump to enable safe proximal and distal clamping. The graft stump should be excised. The vascular lumen should be examined with care, since intimal hyperplasia induced by the graft may be present. Thereafter, a new graft is anastomosed to the axillary artery. We think that adopting such a methodical approach may reduce the risks of neurovascular complications, which may pose higher risk in a reoperative setting. Both patients in the present series were free of neurovascular and infectious complications.
Although the use of the contralateral undissected axillary artery or the femoral artery could have been contemplated in the present cases, we believe that recannulation of the right axillary artery is the best approach for such patients. Use of the left axillary artery does not allow the initiation of cerebral antegrade perfusion, and femoral cannulation significantly increases the risk of embolic complications and malperfusion in cases of aortic dissection.
Our experience as reported here suggests that re-use of the right axillary artery is safe and effective. This approach should be considered in patients previously cannulated in the right axillary artery who must undergo complex aortic reoperation, especially when the initiation of CPB before sternal opening is sought for safety reasons. Meticulous dissection with minimal use of the cautery reduces the risk of local neurovascular complications.
Address for reprints: Dr. François Dagenais, Department of Cardiac Surgery, Laval Hospital, 2725 chemin Sainte-Foy, Sainte-Foy, Québec, Canada G1V 4G5. E-mail: francois.dagenais/at/chg.ulaval.ca