Clinical Results of Cardiopulmonary Bypass with Selective Cerebral Perfusion for Aneurysm of the Ascending Aorta and the Aortic Arch

The purpose of this report is to describe our experience using cardiopulmonary bypass with selective cerebral perfusion in 10 patients whose aneurysms required cross-clamping the aorta and brachiocephalic vessels. Cerebral perfusion was carried out with individual roller pumps. Flow rate was 11.2 ± 4.8 ml per kilogram of body weight per minute to the right axillary artery, 8.5 ± 1.0 to the right common carotid artery, 7.0 ± 2.0 to the left common carotid artery, and 3.9 to the left subclavian artery. All the patients came off bypass smoothly, and only 3 required small amounts of inotropic agents postoperatively. One patient with mycotic aneurysm died in the fourth postoperative week of massive bleeding due to disruption of the suture line. No cerebral complications were experienced. The operative results of this series suggest the usefulness of cardiopulmonary bypass with selective cerebral perfusion, and reasonably favorable outlook for patients with aneurysm involving the aortic arch and the ascending aorta.     

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.     

Total aortic arch replacement for distal aortic arch aneurysm with adhered left lung: report of a case

A 76-year-old man with a history of pleuritis and a cerebral infarct underwent a total arch replacement for an aneurysm of the distal aortic arch. Computed tomography revealed a true aneurysm having a maximum diameter of 70 mm as well as pleural thickening and calcification. Total arch replacement with selective cerebral perfusion was performed through median sternotomy and left thoracotomy. The myocardial ischemic time was shortened by reperfusion from the right axillary artery after the anastomosis of the proximal ascending aorta and the brachiocephalic artery. After the other branches of the arch were anastomosed, a distal anastomosis through the left thoracotomy was then performed using the pull-through method, enabling minimal decortication of the adhered lung. Our surgical procedure for distal arch aneurysm with adhered lung involves the addition of a left thoracotomy, but the reduction in the myocardial ischemic time and lung injury are of benefit.     

Acute intraoperative aortic dissection following axillary artery cannulation

We describe a 75-year-old woman who underwent right axillary artery cannulation in preparation for reconstruction of the aortic arch and the proximal descending aorta for athesosclerotic aortic aneurysm via a 'clamshell' incision. As soon as cardiopulmonary bypass was established, the ascending aorta and the aortic arch was dissected. The innominate artery was dissected including one-third of its circumferance anteriorly. Arterial perfusion was stopped immediately and the left femoral artery was cannulated to resume CPB. We proceeded with replacement of the ascending aorta, the aortic arch and the proximal descending thoracic aorta with a Dacron branched aortic graft. The patient recovered uneventfully. Arterial blood pressure was equal bilaterally.     

An alternative approach in treating an aortic arch aneurysm with an anatomic variant by supraaortic reconstruction and stent-graft placement

We report the case of a 78-year-old man who presented with an aortic arch aneurysm that involved the origin of the left carotid artery and extended up to the origin of the brachiocephalic trunk. The left vertebral artery originated separately from the arch. The patient was treated by a reversed bifurcated prosthesis from the ascending aorta to the brachiocephalic trunk as well as to the left common carotid artery, and a simultaneous left-sided vertebral-to-carotid artery transposition was also performed. Metachronously, the patient later underwent successful endovascular stent-graft placement into the entire aortic arch.     

Partial brachiocephalic perfusion in aortic arch replacement

Eleven patients who underwent replacement of the aortic arch or adjacent areas for aneurysmal disease between 1989 and 1991, using hypothermic cardiopulmonary bypass at 20° to 23°C with partial brachiocephalic perfusion, were studied. Selective perfusion of the innominate artery was performed in all 11 patients through the right axillary artery, while partial brachiocephalic perfusion was carried out using a separate arterial roller pump with a perfusion flow rate of 10ml/kg per min. Direct cannulation to the left common carotid and left subclavian artery was not performed in this method. There were 4 men and 7 women who ranged in age from 26 to 78 years, with a mean age of 56 years. The etiology of aneurysmal disease was aortic dissection in 10 patients, and aortitis syndrome in 1. The cardiopulmonary bypass time was 214.3±39.3 min, aortic cross-clamp time 131.5±33.4 min, and partial brachiocephalic perfusion time 57.6±15.1 min. There were three operative deaths (27.3%), the causes being multiple organ failure, acute peritonitis, and infection of the composite graft in the ascending aorta, in one patient each, respectively. However, there were no deaths related to the technique of partial brachiocephalic perfusion and no neurological complications were seen in this series. Thus, we believe that partial brachiocephalic perfusion under hypothermic cardiopulmonary bypass is safe and effective in surgery for aortic aneurysms involving the aortic arch.     

Axillary artery cannulation for cardiopulmonary bypass reduces cerebral microemboli

BACKGROUND: Aortic cannulation for cardiopulmonary bypass (CPB) is linked to cerebral microemboli emanating from the ascending aorta. Aortic calcification or disease requiring replacement precludes aortic cannulation. Clinical experience with axillary artery cannulation led to the hypothesis that axillary cannulation may be cerebroprotective. METHODS: Five mongrel dogs underwent a median sternotomy and isolation of the right axillary artery. The canine bicarotid brachiocephalic trunk was reconfigured by grafting the origin of the left carotid to the proximal left subclavian artery. Microspheres were injected into the ascending aorta during 4 conditions: before and after reconfiguration, CPB with aortic cannulation, and CPB with axillary cannulation. Brain, kidneys, and skeletal muscle were analyzed for microsphere distribution. RESULTS: Each animal served as its own control for comparison of aortic and axillary cannulation. No significant differences were documented in microsphere deposition for prereconfiguration and postreconfiguration. In the right middle cerebral artery distribution, 2300 +/- 710 microspheres per gram were deposited during aortic cannulation, compared with 540 +/- 110 during axillary cannulation (P <.05). In the left middle cerebral artery region, 2030 +/- 330 microspheres per gram with aortic cannulation were reduced to 1320 +/- 240 with axillary cannulation (P <.05). Axillary cannulation resulted in 73% fewer microspheres in the right brain and 40% fewer microspheres in the left compared with aortic cannulation (P <.05). CONCLUSIONS: Axillary artery cannulation for CPB is cerebroprotective. Altered blood-flow patterns during axillary cannulation may produce retrograde brachiocephalic artery blood flow and competing intracerebral right-to-left collateral blood flow, deflecting emboli from the ascending aorta and arch toward the descending aorta. Expanded use of axillary artery cannulation during cardiac operations could decrease the incidence of stroke.     

Surgical treatment of the aortic arch dissection--a report of two cases operated by partial brachiocephalic perfusion, and open aortic anastomosis

Two patients underwent aortic arch replacement for the dissecting aneurysm of the aorta using a simplified cardiopulmonary bypass (CPB) technique with partial brachiocephalic perfusion, moderate systemic cooling (22 degrees to 23 degrees C), and open aortic anastomosis were reported. The partial brachiocephalic perfusion was accomplished by perfusion to the right axillary artery using separate pump. Open distal anastomosis was performed under low flow hypothermic perfusion of the lower body during selective perfusion to the brain. Cardiopulmonary bypass and partial brachiocephalic perfusion time were 170 minutes, and 30 minutes in one case, and 207 minutes, 56 minutes in the other case. Both patients survived operations, and there were no postoperative strokes, and neurological complications. On the basis of these results, we discussed about supportive methods for aortic arch surgery.     

Breakdown of atheromatous plaque due to shear force from arterial perfusion cannula

Breakdown of an atheromatous plaque in the aorta due to jet from the arterial cannula is reported. The patient underwent mitral valve replacement under ventricular fibrillation because of severe atheromatous change in the ascending aorta, transverse aortic arch, and descending aorta. A dispersive arterial perfusion cannula was inserted into the middle portion of the ascending aorta where the atheromatous change was minimal. Postoperative epiaortic ultrasonography revealed a breakdown of the atheromatous plaque in the lesser curvature. In view of this complication, further study of the effects of shear stress to the diseased aorta should be done by clinical and flow dynamics investigation.     

Right axillary cannulation in the left thoracotomy for thoracic aortic aneurysm

Perfusion from the femoral artery is commonly used in the open proximal method of performing distal aortic arch aneurysm repair or Stanford type B aortic dissection repair under circulatory arrest through left thoracotomy. However, it is associated with a significant risk of retrograde emboli or malperfusion, and with other problems including a restricted time of circulatory arrest to the brain and difficulties in de-airing from the arch branches and proximal ascending aorta. To overcome these problems, we developed a method of performing right axillary perfusion through left thoracotomy.     

Is the axillary artery a suitable cannulation site in aortic surgery?

AIM: The axillary artery is currently gaining interest as an alternative to femoral artery cannulation in aortic surgery. It was the aim of our study to evaluate the feasibility, safety, and efficacy of axillary artery cannulation in a series of patients undergoing surgery of the ascending aorta and/or the aortic arch. METHODS: From 1998 to 2002 cardiopulmonary bypass (CPB) perfusion via the axillary artery was intended in 35 patients (28 male), median age 61 (22-77) years. The underlying disease was acute aortic dissection type A in 22/35 (63%), chronic aortic dissection type A in 2/35 (6%), ascending aortic aneurysm in 8/35 (22%), aortic regurgitation after previous ascending aortic replacement in 1/35 (3%), pseudoaneurysm after Bentall operation in 1/35 (3%) and coronary artery disease with severe arteriosclerosis of the aorta in 1/35 (3%). RESULTS: Conversion to femoral artery or ascending aortic cannulation was necessary in 3 patients. In the other cases, adequate CPB flows of 2.4 l/m2/min were achieved. In 1 case local dissection of the axillary artery occurred after emergency cannulation. No postoperative complications related to axillary artery cannulation, such as upper extremity ischemia, brachial plexus injury, or local wound infection occurred. No new postoperative stroke was noted, hospital mortality was 4/35 (11%) patients. CONCLUSION: Axillary artery cannulation is feasible in the majority of cases and seems to be a safe and effective method in surgery of the ascending aorta and aortic arch. Several disadvantages of femoral artery cannulation and perfusion can be avoided.     

Simultaneous repair of arch and abdominal aortic aneurysms

Objective: Atherosclerotic aneurysms in the aortic arch are associated with abdominal aortic aneurysms in up to 37% of cases. We have developed a single-stage approach to the repair of both aneurysms using a temporary bypass. Subjects: Since November 1996, 5 patients underwent simultaneous repair of aneurysms in the aortic arch and in the infrarenal abdominal aorta, using a new temporary bypass graft technique. Entire arch replacement with simultaneous abdominal aortic aneurysmectomy was performed in one patient. The other 4 patients underwent distal hemiarch replacement distal from the orifice of the brachiocephalic artery with simultaneous repair of the abdominal aortic aneurysm. Method: For the entire arch replacement procedure, blood flow to all major branches of the aortic arch was established using a bifurcated graft. This graft anastomosed to the ascending aorta was used as the proximal inflow of the temporary bypass graft. For the hemiarch replacement procedure, the proximal inflow segment of the temporary bypass graft was anastomosed to the brachiocephalic artery. In both cases, the distal outflow segment of the temporary bypass graft was the graft used for repair of the abdominal aortic aneurysm. In order to prevent any clamp injury, Teflon felt was tightly wrapped around the aorta before the clamp was applied. Results: Evaluation of the hemodynamic parameters measured during cross-clamping of the aortic arch revealed stable distal perfusion to the visceral organs and no excessive increase in cardiac afterload. All patients had an uneventful postoperative course and were discharged within 1 month of surgery. Conclusion: Our temporary bypass method is recommended for simultaneous replacement of aneurysms in the aortic arch and the abdominal aorta.     

Simultaneous repair of arch and abdominal aortic aneurysms. A simple new technique using a temporary bypass graft.

OBJECTIVE: Atherosclerotic aneurysms in the aortic arch are associated with abdominal aortic aneurysms in up to 37% of cases. We have developed a single-stage approach to the repair of both aneurysms using a temporary bypass. SUBJECTS: Since November 1996, 5 patients underwent simultaneous repair of aneurysms in the aortic arch and in the infrarenal abdominal aorta, using a new temporary bypass graft technique. Entire arch replacement with simultaneous abdominal aortic aneurysmectomy was performed in one patient. The other 4 patients underwent distal hemi-arch replacement distal from the orifice of the brachiocephalic artery with simultaneous repair of the abdominal aortic aneurysm. METHOD: For the entire arch replacement procedure, blood flow to all major branches of the aortic arch was established using a bifurcated graft. This graft anastomosed to the ascending aorta was used as the proximal inflow of the temporary bypass graft. For the hemi-arch replacement procedure, the proximal inflow segment of the temporary bypass graft was anastomosed to the brachiocephalic artery. In both cases, the distal outflow segment of the temporary bypass graft was the graft used for repair of the abdominal aortic aneurysm. In order to prevent any clamp injury, Teflon felt was tightly wrapped around the aorta before the clamp was applied. RESULTS: Evaluation of the hemodynamic parameters measured during cross-clamping of the aortic arch revealed stable distal perfusion to the visceral organs and no excessive increase in cardiac afterload. All patients had an uneventful postoperative course and were discharged within 1 month of surgery. CONCLUSION: Our temporary bypass method is recommended for simultaneous replacement of aneurysms in the aortic arch and the abdominal aorta.     

Proximal aortic perfusion with passive cerebral flow: a method to prevent cerebral embolism in the arch and descending aortic operation

Antegrade aortic perfusion is preferable in arch and descending aortic operations. We describe a left lateral approach using an ascending aortic cannula, temporarily relocated within the distal aorta to maintain hypothermic cardiopulmonary bypass of the lower torso. This modification provides continual antegrade systemic perfusion and passive retrograde cerebral flow during arch repair. It minimizes the risk of embolization into the brachiocephalic arteries of debris and malperfusion of the dissected aorta.     

Distal arch aneurysm repair using stent-grafting and ascending aorto-left axillary bypass

Background. Transcatheter application of a stent-graft to the angulated aortic segments with critical side branches poses some problems. We report our technique of distal arch aneurysm repairs using stent-grafts inserted through the aortic arch and ascending aorto-axillary bypass.

Patients and Results. Three patients underwent successful distal arch aneurysm repair using a homemade semiflexible stent-graft placed under hypothermic circulatory arrest. The left subclavian artery was reconstructed by an extraanatomic bypass grafting between the ascending aorta and left axillary artery. Postoperative imaging demonstrated reduction of aneurysm size and no endoleaks from an intercostal artery.

Conclusions. Our technique seems to be useful for repair of distal arch aneurysms and is a less invasive procedure.     

Proximal Left Subclavian Artery Aneurysm Presenting Hemoptysis,Hoarseness, and Diplopia: Repair through Partial Cardiopulmonary Bypass and Perfusion of the Left Common Carotid Artery

Isolated true aneurysm of the subclavian artery is rare and can rupture, thrombose, embolize, or cause symptoms by local compression. We describe a case of a 67-year-old man with proximal left subclavian artery aneurysm presenting with hemoptysis, hoarseness, and diplopia. These symptoms suggested that the aneurysm ruptured, that the left recurrent laryngeal nerve was compressed by it, and that its mural thrombus caused cerebral embolism. It was incidentally confirmed that the aneurysm grew at the rate of 1.31 cm/year, from 3.0 to 4.2 cm in diameter for 11 months, preciously measured in a computed tomography scan. The aneurysm was successfully repaired via partial cardiopulmonary bypass and separate perfusion of the left common carotid artery through cross-clamping the descending thoracic aorta and the aortic arch between the origins of the brachiocephalic artery and the left common carotid artery. Neither partial clamping of the aortic arch at the portion branching the left subclavian artery nor taping the aortic arch between the origins of the left common carotid artery and the left subclavian artery could be achieved.     

Bilateral axillary artery inflow in the treatment of a rare case of pseudocoarctation of the aortic arch

The axillary artery is the preferred site for arterial cannulation in operations for ascending aorta and aortic arch replacement in order to reduce perfusion-related morbidity in acute dissection and to prevent cerebral embolism in atherosclerotic aneurysm. We present the case of a patient with a chronic dissection presenting as pseudocoarctation of the aortic arch in which bilateral axillary artery inflow was necessary to perfuse both ascending and descending aorta.     

Total aortic arch replacement with a branched graft and limited circulatory arrest of the brain

BACKGROUND: Total replacement of the aortic arch is commonly performed with either antegrade perfusion of the brachiocephalic arteries by means of direct cannulation or with an interval of hypothermic circulatory arrest of at least 30 to 40 minutes. We present a technique with a branched graft that uses antegrade brain perfusion without the need for direct cannulation of the brachiocephalic arteries or a separate perfusion circuit, with only a brief period of circulatory arrest of the brain. METHODS: Twelve patients underwent resection of the aortic arch through either a midline sternotomy (4 patients) or a bilateral anterior thoracotomy (8 patients). The right axillary artery was used for arterial return and for brain perfusion. After establishing hypothermic circulatory arrest, the brachiocephalic arteries were detached from the aorta, flushed, and occluded with clamps. Hypothermic perfusion of the brain was established through the right axillary artery, and the brachiocephalic arteries were sequentially attached to the limbs of a branched aortic graft. Flow to the brain was then established in the antegrade direction through the axillary artery. RESULTS: The mean duration of circulatory arrest of the brain at a mean nasopharyngeal temperature of 16 degrees C was 8.8 minutes (range, 6-13 minutes). The subsequent period of hypothermic (20 degrees C-22 degrees C) brain perfusion, during which the 3 branches of the graft were attached to the brachiocephalic arteries, averaged 35 minutes (range, 23-44 minutes). All the patients survived the procedure and were discharged from the hospital. No patient sustained a permanent neurologic deficit. One patient had lethargy for 2 days, with full recovery. Nine of the 12 patients were extubated within 72 hours. CONCLUSIONS: This technique obviates the need for direct cannulation of the brachiocephalic arteries and for a separate perfusion circuit and requires only a brief period of circulatory arrest of the brain.     

Three-dimensional numerical simulation of blood flow in the aortic arch during cardiopulmonary bypass

OBJECTIVE: To better understand the mechanism of stroke during cardiopulmonary bypass, it is necessary to obtain information on the location of turbulence, wall pressure, and flow distribution within the aortic arch. METHODS: Blood flow was numerically simulated using the finite element method in the following representative case: a curved arterial cannula was inserted into the anterior wall of the distal ascending aorta 2 cm below the orifice of brachiocephalic artery. Perfusion was performed, with a bypass flow index of 2.5l min(-1) m(-2). Computational grids, consisting of 1,493,297 tetrahedral elements, were generated. RESULTS: The highest wall pressure (3104.8 Pa) was observed at the superior-posterior wall of the aorta below the orifice of the brachiocephalic artery where jet flow impingement occurred. The maximum wall shear stress was 25.1 Pa. High velocity vortex started below the orifice of the brachiocephalic artery. The turbulent flows continued along the posterior wall and then mainly flowed off into the left subclavian artery. Therefore, in the present case, an embolic event in the territory of the left subclavian artery could occur if a plaque was present at the superior-posterior wall of the aorta below the orifice of the brachiocephalic artery. The flow rates in each of the branches were 132, 613, 175, and 821 ml/min for the right subclavian, right common carotid, left common carotid, and left subclavian artery, respectively. CONCLUSION: This study confirmed that blood flow during cardiopulmonary bypass can be simulated and visualized. Computational fluid dynamics could be applied in the future to assess an individual's risk of stroke. Further multiple representative cases need to be simulated.     

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.