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1 Aortic Arch Repair With Right Brachial Artery Perfusion Oğuz Taşdemir, MD, Ahmet Sarıtaş, MD, Şeref Küçüker, MD, Mehmet Ali Özatik, MD, and Erol Şener, MD Cardiovascular Surgery Clinic, Türkiye Yüksek İhtisas Hospital, Ankara, Turkey Background. To determine the effectiveness of unilateral selective cerebral perfusion for aortic arch repair and to discuss possible modifications to enhance technical simplicity. Methods. In the period between January 1996 and April 2001, 104 patients underwent aortic arch repair with the use of right brachial artery low flow (8 to 10 ml/kg per minute) antegrade selective cerebral perfusion under moderate hypothermia (26 C). Mean patient age was years. Sixty-four patients presented with Stanford type A aortic dissection, including 12 with acute dissection; 38 patients had aneurysmal dilatation of the ascending aorta and aortic arch; and 2 patients had isolated arch aneurysm. Ascending and partial arch replacement was performed in 50 patients; ascending and total arch replacement in 33 patients; ascending and descending arch replacement in 19 patients; and isolated arch replacement in 2 patients. Results. Mean antegrade cerebral perfusion time was minutes. One patient with acute proximal dissection died because of cerebral complications. One other patient developed right hemiparesis, which resolved during the second postoperative month without sequela. Other than these 2 cases (1.9%), no other neurologic event was observed. Conclusions. The technique of low flow antegrade selective cerebral perfusion through the right brachial artery may be used for a vast majority of aortic aneurysms and dissections requiring arch repair. This technique does not necessitate deep hypothermia, requires shorter cardiopulmonary bypass and operation times, has the advantage of simplicity, provides optimal vascular repair without time restraints and, in terms of clinical results, is as safe as other techniques for cerebral protection. (Ann Thorac Surg 2002;73: ) 2002 by The Society of Thoracic Surgeons Although during the past decade profound hypothermic circulatory arrest (HCA) and, as an adjunct to it, retrograde cerebral perfusion (RCP), have been the preferred procedures for successful aortic arch repair, these techniques are nevertheless not free of hazards [1, 2]. The need for extended cardiopulmonary bypass times for cooling and rewarming, subsequent coagulation disturbances, and conflicting data regarding the safety and efficacy of RCP [3 5] have compelled us to use a modified selective antegrade cerebral perfusion (ACP) technique with moderate hypothermia. Recently, many authors have published their experiences with antegrade perfusion techniques for aortic arch repair [6 8]. Some authors prefer and advise the use of antegrade perfusion as an adjunct to deep HCA [9]; some prefer to cannulate the brachiocephalic arteries [7]; some prefer anastomosing the grafts first to the arch vessels and then through these grafts perform ACP [8, 9]; and some have used either the subclavian or axillary artery for inflow cannula placement [10]. In this prospective clinical report we have presented our experience in aortic Accepted for publication Feb 7, Address reprint requests to Dr Taşdemir, Kardiyovasküler Cerrahi Kliniği, Türkiye Yüksek İhtisas Hastanesi, Sıhhiye, Ankara 06100, Turkey; otasdemir@superonline.com arch repair and included what we believe to be important simplifications for antegrade perfusion technique. The right brachial artery is cannulated and low-flow ACP is instituted during aortic arch repair. Because the brachiocephalic vessels are not directly cannulated, the modified technique presented here is simple, decreases the risk of embolization, and provides better surgical exposure by not cluttering the field with cannulas and lines. Antegrade brain perfusion is never interrupted, providing whatever necessary time to the surgeon for arch repair. Only moderate hypothermia is used. Neurologic results in this series of 104 patients were excellent. Material and Methods Between January 1996 and April 2001, 104 patients underwent aortic arch reconstruction with right upper brachial artery perfusion for cerebral protection. Their ages ranged from 17 to 74 years (mean years). There were 72 men and 32 women. The aneurysm was a Stanford type A aortic dissection in 64 (including 12 with acute dissection), aneurysmal dilatation of the ascending aorta and aortic arch in 38, and isolated arch aneurysm in 2 patients. Eighteen patients had undergone previous major cardiovascular operations. Thirteen patients un by The Society of Thoracic Surgeons /02/$22.00 Published by Elsevier Science Inc PII S (02)

2 1838 TAŞDEMIR ET AL Ann Thorac Surg ARCH REPAIR WITH BRACHIAL ARTERY PERFUSION 2002;73: Fig 1. Patient is placed in the supine position, with the right upper extremity in slightly more than 90 abduction and slight external rotation. Dotted line designates the incision line. derwent operations under semi-urgent conditions within 48 hours of hospitalization. Surgical Procedures All patients were operated with anesthesia maintained using fentanyl; alpha stat strategy was used for acid base balance during cardiopulmonary bypass. Rectal temperature, electrocardiogram, and arterial pressure in the left upper extremity were monitored. The cardiopulmonary bypass circuit consisted of a venous reservoir, three roller pumps (two for venting and cardiotomy suction and one for arterial return to the patient), and a membrane oxygenator plus heat exchanger. The patients were placed in the supine position, with the right upper extremity in slightly more than 90 abduction and slight external rotation (Fig 1). Placing a towel compress under the upper arm region facilitated the dissection of the brachial artery. Dissection and cannulation of the right upper brachial artery and right common femoral artery, if the use was planned, were done prior to median sternotomy. Extracorporeal circulation, during only the early phases of our experience (20 patients), was established with two arterial return cannulas, which were joined with a Y connector leading to a single roller pump. But as we became convinced that single arterial return cannula in brachial artery provided satisfactory flow, we stopped using the femoral artery. Consequently 84 patients had a single arterial return cannula in the upper brachial artery alone. A bistage single venous cannula was positioned in the right atrium for the venous return. The left ventricle was vented through the left ventricular apex. The aorta was crossclamped as soon as body temperature reached 26 C or before if ventricular fibrillation occurred. Myocardial protection was provided with intermittent antegrade and retrograde cold blood cardioplegia and topical cooling. Surgical Technique for Exposure and Cannulation of the Upper Brachial Artery A medial longitudinal incision is made along the bicipital groove into the axillary fossa (Fig 1). The incision follows the medial border of the biceps along its groove, which Fig 2. Exposure and control of the upper brachial artery and a nonwire-reinforced venous return catheter, the tip of which is trimmed to 16 to 18F according to the size of the patient s brachial artery. separates the biceps anteriorly from the triceps posteriorly. An incision 6 to 8 cm long is adequate for exposure of the artery. If necessary, proximal or distal extension of the incision can be made easily. The skin incision should be made anterior to the basilic vein. The incision is carried down to the fascia of the biceps after identifying its medial border. The muscle is then retracted anteriorly; the neurovascular bundle appears under a thin aponeurotic sheath, which is then opened. The median nerve is exposed, mobilized laterally, thus exposing the artery (Fig 2). Then by passing a shoestring tie around the artery proximally and distally, arterial control is achieved. After heparin administration, arterial soft clamps are placed proximal and distal to the cannulation site. Transverse arteriotomy is made by scalpel. The artery is cannulated with a nonwirereinforced venous return catheter (California Medical Laboratories, Irvine, CA), the tip of which is trimmed to 16 to 18F diameter according to the size of the patient s brachial artery. The catheter is gently inserted into the Fig 3. Application of soft clamps and transverse arteriotomy. Insertion and fixation of the cannula.

3 Ann Thorac Surg TAŞDEMIR ET AL 2002;73: ARCH REPAIR WITH BRACHIAL ARTERY PERFUSION 1839 artery, as its tip is positioned 5 to 7 cm proximal to the arteriotomy. The proximal shoestring tie is then fastened and secured by a heavy silk knot around it (Fig 3). The cannula is then connected to the cardiopulmonary bypass circuit as usual for any arterial return cannula. Operative Data Cardiopulmonary bypass is instituted with 2.2 L 1 min 1 m 2. When rectal temperature has reached 26 C, femoral arterial return, if present, is clamped. The flow of the arterial return through the upper brachial artery cannula is adjusted to 500 to 600 ml/min (8 to 10 ml/kg per minute). The innominate, left common carotid, and, occasionally, the left subclavian artery (but only if the returning blood interferes with suturing) are clamped with soft vascular clamps. Care is taken to place soft vascular clamps away from atherosclerotic areas with the help of digital examination. Cross-clamp on the aorta is released. Early in this series, we measured the perfusion pressure by a 20-gauge arterial line set to the distal innominate artery and kept it around 50 mm Hg by adjusting the flow. We no longer perform this pressure measurement and believe that it is not necessary as long as the flow is kept at 500 to 600 ml/min. All arch reconstructions and distal anastomosis were performed with open aortic anastomosis technique while low-flow perfusion through the upper brachial artery continued. After terminating the distal repair, with the head of the table tilted downward, the flow through the upper brachial artery cannula is increased gradually as the soft clamps on the brachiocephalic vessels are released. Air is removed from the vessels and grafts, which are then filled with blood, and the distal graft is cross-clamped. Normal flow rate is reached through the upper brachial artery cannula and rewarming is begun in accordance with the time necessary for proximal repair. Should a femoral arterial cannula have been placed, it is not used and is kept clamped during rewarming in order not to cause a retrograde particulate or air embolism. Collagen-impregnated Hemashield (Meadox Medicals, Oakland, NJ) or collagen-coated Intergard (InterVascular, Cédex, France) grafts are used. For patients needing total root replacement, composite grafts are prepared with St. Jude bileaflet mechanical aortic valves (St. Jude Medical, St. Paul, MN). The distribution of the various repair techniques is shown on Table 1. Operations were performed electively in 91 patients who were diagnosed as having chronic dissection with or without aneurysm or aneurysm only, and semi-urgently in 13 patients who were operated on within 48 hours of admission because of acute proximal dissection or rupture of the aneurysm into neighboring structures. Ascending and partial arch replacement was performed in 50 patients; ascending and total arch replacement in 33 patients; ascending and descending arch replacement in 19 patients; and isolated arch replacement in 2 patients. Data were expressed as mean standard deviation. Because the aim of the study was to determine the neurologic outcome and because only one mortality and one transient neurologic event occurred, we did not perform a statistical analysis. Results Mean cardiopulmonary bypass time was minutes (range 48 to 237 minutes). Mean aortic cross-clamp time was minutes (range 35 to 186 minutes). The mean period of low-flow ACP through the right upper brachial artery was minutes (range 19 to 80 minutes). Hospital deaths occurred in 8 (7.6%) patients: 5 of whom had proximal dissections and 3 of whom had semi-urgent acute dissections. Operative mortality for dissection and aneurysm cases was 7.8% (5 of 64 patients) and 7.5% (3 of 40 patients), respectively. Of these 8 deaths, only one was attributed to neurologic complication (0.9%). This patient had right-sided hemiparesis as she was admitted to the hospital and underwent semiurgent operation for acute type A dissection. She did not show any sign of awakening postoperatively and died due to multiorgan failure on the eighth postoperative day. Five deaths were due to low cardiac output and subsequent multiorgan failure or sepsis, although all were neurologically intact. Of these, 3 were reoperations: 2 had had previous coronary artery bypass grafting and 1 had an aortic valve replacement. The patient with previous aortic valve replacement had an ascending and aortic arch aneurysm of 9 cm in diameter and was operated on urgently because of hemodynamic instability. During his operation, fistulization to the right atrium and superior vena cava was observed. Repair of the right atrium and superior vena cava was made along with a modified Bentall operation and hemi-arch replacement. The patient did well at first, but developed low cardiac output and died on 10th postoperative day. Two other patients died because of pulmonary complications. Both had chronic obstructive pulmonary disease. Data on the 8 hospital deaths are presented on Table 2. Table 1. Operative Technique Graft replacement of Ascending partial aortic arch 25 Modified Bentall 17 AVR and supra coronary 2 CABG 5 MVR 1 Ascending total aortic arch 16 Modified Bentall 11 AVR and supra coronary 1 CABG 5 Ascending arch descending (elephant trunk) 13 Modified Bentall 6 Aortic arch 2 Total 104 AVR aortic valve replacement; CABG coronary artery bypass grafting; MVR mitral valve replacement. n

4 1840 TAŞDEMIR ET AL Ann Thorac Surg ARCH REPAIR WITH BRACHIAL ARTERY PERFUSION 2002;73: Table 2. Hospital Mortality Patient No. Age (years) Sex Surgical Technique Aortic Pathology Prior Operation Days After Operation to Death Cause of Death 1 45 F Asc arch desc Acute dissection None 8 Neurologic 2 60 M Asc arch desc Acute dissection None 4 LCO, MOF 3 66 F Asc arch Aneurysm None 9 Pulmonary complication 4 68 M Asc arch desc Acute dissection None 8 Pulmonary complication 5 71 M Asc partial arch Aneurysm None 5 LCO CABG 6 60 M Asc partial arch Aneurysm (ruptured) AVR 10 LCO, MOF 7 67 M Asc arch Chronic dissection CABG 9 LCO, sepsis CABG 8 62 F Asc arch CABG Chronic dissection CABG 4 LCO, MOF Asc ascending; AVR aortic valve replacement; CABG coronary artery bypass grafting; desc descending; F female; LCO low cardiac output; M male; MOF multiorgan failure. One patient experienced transient right hemiparesis, which totally resolved during the second postoperative month. No other cerebral complication occurred in this series. Including the patient who died with neurologic complications, the total neurologic incidence rate was 1.9%. Postoperative hemorrhage requiring resternotomy occurred in 3 patients. Two of these were because of anastomotic leakage. Excluding these 3 patients, average packed red blood cell requirement was units and the average postoperative chest tube drainage was ml. Complications involving the upper brachial artery cannulation occurred in only 1 patient. Radial and ulnar pulses were lost on the second postoperative day and the upper brachial artery was re-explored under local anesthesia. Flow was blocked distal to the repair site. Arteriotomy was reopened, embolectomy was performed with a Fogarty catheter, and an approximately 1-cm arterial segment was excised and then reanastomosed in an end-to-end fashion. The patient recovered without any further complication. Hospital survivors have been followed up for 1 month to 5 years postoperatively. Average patient follow-up reached years. Four late deaths occurred 11, 14, 22, and 31 months after the operation, at least one of which was attributed to arrhythmia. Two late reoperations were necessary due to extension of the native aortic disease. The patients who were followed up were in NYHA I or II functional classes. Comment Currently, three main strategies for brain protection during aortic arch repair are used HCA, selective ACP, and RCP. Hypothermic circulatory arrest alone has the major limitation of time [11] in addition to the potential hazard to various organ systems of deep hypothermia [12]. Whether using RCP as an adjunct to HCA eliminates the time constraint or not is still a controversial issue [9, 13, 14]. The ACP technique seems to be the more accepted physiologic solution. However, cerebral complications reported by authors using ACP differ widely [7, 9, 13, 15, 16]. These discrepancies may be due to different techniques used for instituting ACP such as direct cannulation [16] or various types of graft attachments to the arch vessels [7, 9]. All these techniques may have some detrimental effects because attaching the grafts necessitates cessation of cerebral circulation, cannulas and grafts will increase the clutter in the operative field, and direct cannulation of arch vessels may increase the risk of particulate and air embolization. Most authors blame the embolic events rather than global hypoperfusion for neurologic outcomes observed after aortic arch repair. Choosing upper brachial artery for cannulation site, as we prefer, overcomes all the mentioned drawbacks. Use of this unilateral cerebral perfusion technique raises concerns about the adequacy of perfusion to the contralateral hemisphere. The two vertebral arteries and two internal carotid arteries supply the brain, and an extensive anastomosis (the circulus arteriosus) exists between them (Fig 4). The anterior communicating artery joins the two anterior cerebral arteries to each other; behind, the basilar artery divides into the two posterior cerebral arteries, each of which is joined to the internal carotid artery of the same side by the posterior communicating artery. Minor ophthalmic and leptomeningial collaterals also exist. The arteries forming the arterial circle show much variation in caliber, sometimes being hypoplastic and at other times totally absent. About 60% of the circles display anomalies. Nevertheless, in the classic anatomical texts it is mentioned that about 90% or more of these circles have a completely circular channel [17]. Anatomic dissections and radiologic studies on different populations have been conducted for identifying the anomalies of circle of Willis. A magnetic resonance imaging study on an Italian population mentioned the absence of the anterior communicating artery in 3% of the patients, and the hypoplasia of both anterior and posterior communicating arteries in about 2% [18].

5 Ann Thorac Surg TAŞDEMIR ET AL 2002;73: ARCH REPAIR WITH BRACHIAL ARTERY PERFUSION 1841 Fig 4. Circulation through the circle of Willis during arch repair. Innominate and left common carotid arteries clamped. Hypothetically the absence of one of the three communicating arteries does not carry any risk for underperfusion because the blood coursing through the right upper brachial artery will perfuse the whole brain through the vertebral, basilar, and internal carotid arteries (Fig 4). The only combination that will carry the potential for contralateral underperfusion would be the absence of both anterior and left posterior communicating arteries; even if that is the case, not the whole left hemisphere but the frontal and temporal parts would be affected (Fig 4). This combination specifically has not been mentioned in the literature and we can probably assume this condition to be very rare. Hoksbergen and coworkers [19] published their study on cerebrovascular atherosclerosis in asymptomatic patients, reporting anterior collateral pathway of the circle of Willis to be nearly always patent. In another study, researchers found that a posterior communicating artery as small in size as 1 mm prevented watershed infarcts among patients with internal carotid artery occlusion [20]. Adequacy of collateral flow in the circle of Willis can be tested preoperatively with invasive angiographic methods and pressure measurements. However, these methods carry a high risk of stroke and are not suitable for dissections and urgent cases. Functional measurement of collateral cerebral blood supply can be included in the planning of selective ACP using the right upper brachial artery and may be made at the time of operation before initiating cardiopulmonary bypass. The carotid artery backpressure reflects the collateral flow available at the level of the circle of Willis, but in the setting of dissection in which flaps may exist in the brachiocephalic vessels, this technique may have little value. In our experience, at the initiation of antegrade perfusion, visual assessment of the returning blood through left common carotid and subclavian arteries has been the most valuable proof of contralateral hemispheric perfusion, and its amount was always satisfactory. Initially, the decision for using the right upper brachial artery alone for arterial return was undertaken for patients with known atherosclerotic plaques or aneurysm of the abdominal aorta in order to prevent retrograde embolization. As our experience grew, however, we observed that the single arterial return cannula in the right upper brachial artery was perfectly satisfactory for providing necessary flow both during ordinary cardiopulmonary bypass to the body and during arch repair to the brain. Consequently we stopped using the femoral artery. Although some complications as brachial plexus injury and axillary artery thrombosis have been reported, many authors found that use of subclavian or axillary artery cannulation for cardiopulmonary bypass provided satisfactory flows [10, 21, 22]. The same can be said for upper brachial artery perfusion, because the cannula we use is about 18F, which provides a flow of well above 4 L/min. Technically, we believe that upper brachial artery cannulation is much simpler than cannulating the subclavian or axillary artery and in our experience is associated with fewer complications, which if they occur, are easier to repair. The cooling of patients in this series was down to 26 C. Because antegrade perfusion is never interrupted, oxygen demand of the brain tissue at this temperature can be provided with a blood flowof8to10ml 1 min 1 m 2 without concern for the time spent on arch repair. Because deep hypothermia is not used, less time is necessary for cooling and rewarming, and its potential hazards are avoided. Although in this series the mean period of low-flow ACP through the right upper brachial artery was minutes (range 19 to 80 minutes), 24 of the 104 patients had low-flow periods longer than 60 minutes. None of these patients had any neurologic complications and we have not encountered any serious systemic complications resulting from selective noncerebral systemic arrest in any patients. In our current practice, this simplified right upper brachial artery perfusion technique is the standard for elective and emergent operations of atherosclerotic or degenerative arch aneurysms and dissections. It provides

6 1842 TAŞDEMIR ET AL Ann Thorac Surg ARCH REPAIR WITH BRACHIAL ARTERY PERFUSION 2002;73: technical simplicity, better surgical exposure with enhanced comfort for the surgeon, longer safe-time periods for arch repair, shorter cardiopulmonary bypass times, fewer bleeding complications, less risk of retrograde cerebral embolization, and lastly, excellent neurologic results for the patient. We express our gratitude to Sonny J. Stetson and Dr. Larry O. Thompson, Baylor College of Medicine, and Michael E. De- Bakey, Department of Surgery, Baylor College of Medicine, Houston, Texas, for editorial assistance. References 1. Coselli JS, LeMaiare SA. Experience with retrograde cerebral perfusion during proximal aortic surgery in 290 patients. J Cardiac Surg 1997;12(Suppl): Westaby S, Katsumata T, Vaccari G. Arch and descending aortic aneurysms: influence of perfusion technique on neurological outcome. Eur J Cardiothorac Surg 1999;15: Usui A, Oohara K, Liu TL, et al. Comparative experimental study between retrograde cerebral perfusion and circulatory arrest. J Thorac Cardiovasc Surg 1994;107: Boeckxstaens CJ, Flameng WJ. Retrograde cerebral perfusion does not perfuse the brain in nonhuman primates. Ann Thorac Surg 1995;60: Ye J, Yang L, Del Bigio MR, et al. Retrograde cerebral perfusion provides limited distribution of blood to the brain: a study in pigs. J Thorac Cardiovasc Surg 1997;114: Bachet J, Guilmet D, Goudot B, et al. Antegrade cerebral perfusion with cold blood: a 13 years experience. Ann Thorac Surg 1999;67: Kazui T, Washiyama N, Muhammed BAH, Terada H, Yamashita K, Takinami M. Improved results of atherosclerotic arch aneurysm operations with a refined technique. J Thorac Cardiovasc Surg 2000;121: Jacobs MJ, de Mol BA, Veldman DJ. Aortic arch and proximal supraaortic arterial repair under continuous antegrade cerebral perfusion and moderate hypothermia. Cardiovasc Surg 2001;9: Hagl C, Ergin MA, Galla JD, et al. Neurologic outcome after ascending aorta/aortic arch operations: effect of brain protection technique in high risk patients. J Thorac Cardiovasc Surg 2001;121: Neri E, Massetti M, Capannini G, et al. Axillary artery cannulation in type A aortic dissection operations. J Thorac Cardiovasc Surg 1999;118: Svensson LG, Crawford ES, Hess KR, et al. Deep hypothermia with circulatory arrest. Determinants of stroke and early mortality in 656 patients. J Thorac Cardiovasc Surg 1993;106: Ergin MA, Galla JD, Landsman SL, Quintana C, Bodian C, Griepp RB. Hypothermic circulatory arrest in operations on the thoracic aorta: determinants of operative mortality and neurologic outcome. J Thorac Cardiovasc Surg 1994;107: Higani T, Kozawa S, Asada T, et al. Retrograde cerebral perfusion versus selective cerebral perfusion as evaluated by cerebral oxygen saturation during aortic arch reconstruction. Ann Thorac Surg 1999;67: Juvonen T, Zhang N, Wolfe D, et al. Retrograde cerebral perfusion enhances cerebral protection during prolonged hypothermic circulatory arrest: a study in a chronic porcine model. Ann Thorac Surg 1998;66: Dossche KM, Schepens MAAM, Morshuis WJ, Muysoms FE, Langemeijer JJ, Vermeulen FEE. Antegrade selective cerebral perfusion in operation on the proximal thoracic aorta. Ann Thorac Surg 1999;67: Ueda T, Shimizu H, Ito T, et al. Cerebral complications associated with selective perfusion of the arch vessels. Ann Thorac Surg 2000;70: Gabella G. Cardiovascular system. In: Williams PL, Bannister LH, Martin MB, et al., eds. Gray s anatomy. New York: Churchill Livingstone, 1995: Macchi C, Catini C, Federico C, et al. Magnetic resonance angiographic evaluation of circulus arteriosus cerebri (circle of Willis): a morphological study in 100 human subjects. Ital J Anat Embryol 1996;101: Hoksbergen AWJ, Legemate DA, Ubbink DT, Jacobs MJHM. Collateral variations in circle of Willis in atherosclerotic population assessed by means of transcranial color coded duplex ultrasonography. Stroke 2000;31: Schomer DF, Marks MP, Steinberg GK, et al. The anatomy of the posterior communicating artery as a risk factor for ischemic cerebral infarction. N Engl J Med 1994;330: Sabik JF, Lytle BW, McCarthy PM, Cosgrove DM. Axillary artery: an alternative site of arterial cannulation for patients with extensive aortic and peripheral vascular disease. J Thorac Cardiovasc Surg 1995;109: Bichell DP, Balaguer JM, Aranki SF, et al. Axilloaxillary cardiopulmonary bypass: a practical alternative to femoro femoral bypass. Ann Thorac Surg 1997;64:702 5.