| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | SEARCH |
|
MMCTS
(October 6, 2008). doi:10.1510/mmcts.2008.003418 Copyright © 2008 European Association for Cardio-thoracic Surgery Procedure Innominate artery cannulationDepartment of Thoracic and Cardiovascular Surgery, Aristotle University of Thessaloniki, AHEPA Hospital, Thessaloniki, Greece * Corresponding author: Sakellaridi 25, 542 48 Thessaloniki, Greece Tel: +30-2310-329729; fax: +30-2310-329729 Email: antonits{at}otenet.gr
Innominate artery cannulation is indicated mainly for surgery which involves aortic root and aortic arch when pathology precludes standard cannulation of the ascending aorta. Thus, it can be used as the procedure of choice in cases of ascending aortic aneurysm, type A aortic dissection, porcelain aorta and reoperation for coronary or aortic surgery. It is performed through a standard median sternotomy, hence avoiding the complications of a second incision. It provides antegrade systemic and cerebral flow that is associated with improved distal organ perfusion and reduced rate of retrograde cerebral embolization compared to femoral arterial cannulation, Moreover, it eliminates potential complications from axillary artery cannulation, such as dissection, upper extremity malperfusion and brachial plexus injury. It is contraindicated in cases of excessive calcification and acute dissection clearly involving the innominate artery.
Key Words: Cannulation • Cardiopulmonary bypass • Innominate artery
Choosing the proper arterial cannulation site for the establishment of cardiopulmonary bypass (CPB) is of paramount importance for the management of thoracic aortic pathology. Routine ascending aortic cannulation is not always feasible in the setting of Stanford type A acute aortic dissection or extensive atherosclerotic aneurysms. Femoral artery cannulation provides an alternative route, however, it is associated with the risk of retrograde cerebral embolization from debris and thrombi of the descending aortic lumen as well as organ hypoperfusion in cases of dissected double lumen aorta [1]. Remote axillary artery cannulation provides adequate systemic blood flow allowing for enhanced cerebral protection providing selective antegrade cerebral perfusion (SACP) in cases of circulatory arrest [2]. In this article we describe our surgical technique of innominate artery (IA) cannulation for establishing CPB and SACP during surgery of the thoracic aorta.
A preoperative computed axial tomography scan clearly identifies pathology of the IA. Absences of excessive calcification or dissection of the vessel comprise necessity in proceeding with cannulation of the IA. The right radial artery is percutaneously cannulated preoperatively for arterial pressure recording. The patient is placed in the standard supine position and draped in the usual fashion. Midline sternotomy is performed. Mediastinal fat is divided with electrocautery. Mediastinal pleura are carefully dissected off the pericardium (Video 1). We prefer to cannulate the IA prior to opening the pericardium.
The innominate vein is carefully dissected and pulled caudally with a tape so as to facilitate exposure of the underlying IA (Video 2).
In order to facilitate exposure the innominate vein can be divided in selected cases and ligated or reconstructed at the end. However, being left ligated it can result in a transient left arm edema. The only precaution is to ask the anesthesiologist to put all the lines on the right side. The IA is examined thoroughly with palpation to exclude any significant atherosclerotic plaques and carefully dissected (Video 3). Otherwise intraoperative echo-scanning can be used for the same purpose. Cannulation site should be below IA bifurcation and about 2–3 cm distal to its origin from the aortic arch.
Double 4-0 Prolene purse string pledgetted sutures are placed on the anterior surface in the usual fashion (Video 4).
According to the size of the IA, a regular 19Fr–21Fr short-tipped aortic cannula can be easily used (EZ Glide Aortic Cannula, Edwards Lifesciences LLC, Irvine, CA, USA – MMCTSLink 134 – Photo 1). Stassano et al. developed a modified right-angled cannula with a supplemental hole in the elbow [3]. However, any kind of regular aortic cannula of proper size can be used. The IA is then stabbed, preferably directly or after clamping it at both ends, and the cannula introduced with its tip pointing towards the aortic arch.
Purse strings are snugged and the cannula is then affixed to the tourniquets (Video 5). The position of the cannula allows for both antegrade and retrograde flow through the IA.
The remainder of the cannulation and establishment of the CPB is accomplished in the usual fashion (Video 6).
During systemic circulatory arrest, SACP can be established by clamping the IA proximal to the cannula. The selective perfusion flow of 10 ml/kg/min can be adjusted to keep a right radial arterial pressure of 40–70 mmHg. Decannulation is performed by releasing the tourniquets, removing the cannula and tying down the pledgetted purse string sutures.
We are currently using this technique routinely in our institution for all cases of ascending aortic aneurysm or type A aortic dissection as well as in reoperations involving the ascending aorta or the aortic arch. In a series of 22 patients (10 patients with acute type A aortic dissection, nine patients with ascending aortic aneurysm and three patients with reoperation for aortic aneurysm) we achieved adequate CPB flows in all cases. There were no complications attributable to the cannulation site. Cerebral oxygenation was routinely monitored with near-infrared spectroscopy (INVOS Somanetics, Troy, MI, USA – MMCTSLink 151). During hypothermic systemic circulatory arrest and SACP through the IA satisfactory cerebral oxygenation was achieved in all cases. There were four postoperative deaths from complications not related to the cannulation site. No postoperative neurologic events were noted to the patients. Di Eusanio et al. have published a series of 55 patients using IA cannulation [4]. Fifty-two patients had aortic aneurysm, two had a type A aortic dissection and one a supravalvular aortic stenosis. Mortality rate was 3.6%. They noted one case with temporary neurologic dysfunction.
Innominate artery cannulation is indicated mainly for surgery which involves aortic root and aortic arch when pathology precludes standard cannulation of the ascending aorta [5]. Thus, it can be used as the procedure of choice in cases of: (a) ascending aortic aneurysm, (b) type A aortic dissection, (c) porcelain aorta and (d) reoperation for coronary or aortic surgery [6]; in cases of reoperation ascending aorta is usually filled with Teflon felt pledgets, sutures and grafts that are either patent or occluded. Innominate artery is usually untouched from prior surgery and can easily accommodate the arterial cannula. In the vast majority of cases of ascending aortic aneurysm or ascending aortic dissection, IA is spared from involvement. Intraoperative transesophageal echocardiography is recommended to exclude inadvertent cannulation of the false lumen in cases of aortic dissection. Atherosclerosis of the aortic arch most commonly involves the curvature and the origin of the arch vessels, however, leaves the IA trunk mostly free from disease. Preoperative non-contrast enhanced computed tomography usually confirms this. Innominate artery cannulation can be performed through standard median sternotomy, thus eliminating the need for a second incision for arterial access (i.e. axillary, groin incision). Our policy of avoiding opening of the pericardium enables for safe CPB establishment in cases of ruptured aortas. The cannulation site is always under the surgeon's eyes, which reduces the risk of blood loss in the operative field and kinking of the cannula. It provides antegrade flow that is associated with improved distal organ perfusion and reduced rate of retrograde cerebral embolization compared to the standard femoral arterial cannulation, particularly in patients with acute dissection. Innominate artery is larger in caliber compared to the axillary artery and can be cannulated directly, thus eliminating the need to attach a side-graft before cannulation. Frequent complications of axillary artery cannulation, such as dissection, upper extremity malperfusion or brachial plexus injury can be avoided [7]. Main contraindications against cannulation of the IA include acute dissection clearly extending into the IA and excessive calcification of the vessel that increase the risk of cerebral embolization and malperfusion. Even though both these conditions are rare, careful preoperative evaluation with computed tomography and intraoperative transesophageal echocardiography and thorough intraoperative inspection are mandatory to exclude this pathology. In conclusion, we consider IA cannulation an attractive as well as effective option for thoracic aortic surgery and reoperations that can be performed with a simple, fast and safe technique. This method provides adequate antegrade CPB flow and SACP. It comprises a useful addition to the expanding selection of potential cannulation sites and has successfully replaced axillary artery cannulation in our institution.
|
|||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | SEARCH |
Top
Summary
Introduction
