Symmetry Aortic Connector System Research Articles

Erratum to: Long-term clinical outcome of the symmetry aortic connector system in off-pump coronary artery bypass grafting. Thorac Cardiovasc Surg 2013;61(8):669-675

Erratum to: Long-term clinical outcome of the symmetry aortic connector system in off-pump coronary artery bypass grafting. Thorac Cardiovasc Surg 2013;61(8):669-675

Long-Term Clinical Outcome of the Symmetry Aortic Connector System in Off-Pump Coronary Artery Bypass Grafting

Several short-term and midterm follow-up studies of the Symmetry aortic connector system showed controversial results. The objective of the present study was assessing the long-term clinical outcome of patients operated with the Symmetry device and to compare the results with hand-sewn control patients. A retrospective case-control study of 156 (46 cases, 110 controls) consecutive patients, that underwent off-pump coronary revascularization, between January 2001 and December 2004, was conducted. Study endpoints were all-cause mortality, coronary reintervention and postoperative stroke. There was no difference in survival between cases and controls (89.1 vs. 82.4%, p = 0.27) after 8 years of follow-up. No significant difference could be detected between cases and controls with respect to overall long-term coronary reintervention free survival (82.6 vs. 88.9%, p = 0.41) and freedom from coronary reintervention due to proximal vein graft failure (91.3 vs. 96.3%, p = 0.24). The use of Symmetry device could not be identified as independent risk-factor of coronary reintervention due to proximal vein graft failure (p = 0.25). Furthermore, postoperative stroke rates were comparable between cases and controls (0.0 vs. 0.9%, p = 1.00). This study suggests that the use of the Symmetry Bypass Connector was not associated with adverse outcome in terms of overall survival, long-term coronary reintervention free survival, freedom from reintervention due to proximal vein graft failure and postoperative stroke.

Forty-one-month follow-up of the Symmetry aortic connector system for proximal venous anastomosis

Results of short- and midterm follow-up studies of the patency rate of the Symmetry aortic connector systems (St Jude Medical, Inc, Minneapolis, Minn) are controversial. Long-term follow-up studies are still lacking (so far, the longest mean follow-up period was 19 months). The aim of our study was (1) to evaluate the patency rate of this device over a longer time-period and (2) to analyze risk factors for graft occlusion. Between November 2000 and July 2003, 76 Symmetry aortic connector systems were implanted in 42 patients. At follow-up, 24 patients with 44 mechanical connectors were studied with 64-slice cardiac computed tomography. Eight patients had died previously, 6 patients refused to undergo a computed tomographic scan, and 4 patients had to be excluded because of impaired renal function. From a total of 44 mechanical connectors studied, 24 (55%) were occluded, 20 (45%; confidence intervals 31%-61%) were patent, and 7 of these grafts showed stenosis in the area of the connector. Mean follow-up was 41 +/- 10 months (18-52 months). Sex, age, left main stenosis, hyperlipidemia, hypertension, renal failure, target vessel, stenosis of the target vessel, diameter of the target vessel, type of surgical intervention, diabetes, ejection fraction, postoperative anticoagulation regimen, and the connector size showed no significant influence on the bypass graft patency (P > .05). The bypass graft flow was recognized to be the only risk factor for bypass graft occlusion (P = .0256). Midterm follow-up data show a high number of occluded Symmetry aortic connector system vein grafts. On the basis of these observations, the use of the connector was abandoned at our institution.

Cerebral microembolization during off-pump coronary artery bypass surgery with the Symmetry aortic connector device

The use of aortic connector systems for proximal vein grafts in off-pump coronary artery bypass grafting might minimize aortic manipulation by eliminating the need for partial aortic clamping. The objective of this study was to asses whether use of a Symmetry connector (St Jude Medical, Inc, St Paul, Minn) reduced intraoperative cerebral embolization. Thirty-two consecutive patients underwent off-pump coronary artery bypass grafting. Sixteen patients received at least one mechanical proximal vein graft anastomosis with a Symmetry aortic connector system. Sixteen patients representing the control group underwent operations with standard suturing techniques using partial aortic clamping. During surgical intervention, all patients were monitored continuously with multifrequency transcranial Doppler scanning, which detected and differentiated cerebral emboli. There were significantly more cerebral emboli in the Symmetry group (median, 36) compared with the control group (median, 11; P = .027). This was due to a higher number of gaseous emboli in the Symmetry group than in the control group (median, 27 vs 8; P = .014), whereas there was no significant difference regarding the number of solid emboli (median, 7 vs 3; P = .139). Use of a Symmetry connector system during proximal vein graft anastomosis increased the number of emboli to the brain compared with a standard technique in coronary bypass surgery without cardiopulmonary bypass.

Early and midterm patency of the proximal anastomoses of saphenous vein grafts made with a Symmetry Aortic Connector System

The purpose of this study was to investigate (1) the early and midterm patency rates in saphenous vein grafts that were anastomosed with the Symmetry Aortic Connector System (St Jude Medical, Inc, St Paul, Minn) and (2) risk factors for graft occlusion. Thirty-one patients underwent off-pump coronary artery bypass grafting for proximal saphenous vein graft anastomoses with the aortic connector system. Intraoperative graft flow was studied with transit time flowmetry, and angiography was performed before discharge in 29 cases. Midterm (at least 1 year after the operation) saphenous vein graft patency was assessed by coronary angiography or 3-dimensional coronary computed tomography in 27 cases. Postoperative angiography demonstrated a 100% patency rate and no significant stenosis at the connector-anastomosed sites. The 1-year patency rate of the saphenous vein grafts with the aortic connector system was 92.6%, with 2 cases of saphenous vein graft occlusion. Both of these cases had low graft flow and poor left ventricular function documented during the operation. Once surgical errors had been ruled out, the 1-year patency rate of proximal saphenous vein grafts anastomosed with the aortic connector system was favorable. Poor left ventricular function and low graft flow during the operation were risk factors for midterm graft occlusion. Selection of the target vessel and its runoff may also be an important determinant of long-term patency.

Severe Stenosis of Anastomoses by Using the Symmetry Aortic Connector System

The St. Jude Medical Symmetry Aortic Connector System was developed to create the proximal vein graft anastomoses in coronary artery bypass grafting. We describe three symptomatic patients with severe stenosis of the proximal anastomosis several months after using the Symmetry aortic connector system. Intravascular ultrasound study showed anastomotic neointimal hyperplasia.

Skeletonized radial artery graft with the St. Jude medical symmetry bypass system (aortic connector system)

Background We report our initial experience with an automatic anastomotic device using skeletonized radial artery in patients requiring off-pump coronary artery bypass grafting (CABG). Methods St. Jude Medical, Inc, Symmetry Bypass System (aortic connector system [ACS]) (St Jude Medical, St. Paul, MN) was used in ten patients. Ten consecutive patients who underwent off-pump CABG and who received at least one radial artery graft proximal anastomosis using the ACS were evaluated. The radial artery (RA) was harvested in a skeletonized fashion and applied to the ACS in the same manner as applying saphenous vein graft. The creation of the anastomosis lasted no longer than a few seconds. Results Our attempt to use the ACS for proximal anastomosis of the RA was successful in all ten patients. Mean operating time was 3.2 ± 0.6 minutes and an average of 3.0 ± 0.9 bypass grafts (range, 2 to 5 grafts) were performed. There was no postoperative fatal complication. Postoperative angiographic control showed that all grafts were widely patent including grafts other than the RA. During the mean postoperative follow-up of 10.3 ± 2.9 months, there was no cardiac-related event in any patient. Conclusions The St. Jude Medical Symmetry aortic connector system allows the construction of uniform and widely patent anastomoses in RA graft and does not require aortic side biting. Skeletonization of the RA is a safe and effective technique for applying ACS in off-pump CABG using multiple arterial grafts.

Invited commentary

In an effort to reduce the complication rate of coronary artery bypass surgery, all aortic manipulations have to be critically analyzed and reevaluated. The use of semiautomated anastomosis devices accomplishes the creation of an aorto-to-graft anastomosis without a side-biting aortic clamp.Watanabe et al describe the use of radial arteries instead of vein grafts for mechanical aortic graft connection with the St. Jude Medical Aortic Connector in CABG patients. Every surgeon who has used the Aortic Connector in vein grafts in the past might have thought of the possibility to use it in radial arteries or other arterial grafts also. These other surgeons were well advised not to use it yet for the radial artery, although the connector is feasible technically. The radial artery is a muscular artery and is highly at risk for vessel wall spasm, which might cause a string phenomenon. Therefore, when harvesting and storing the radial artery, exceptional care and delicate handling is mandatory to prevent spasm. It seems rather rough to pull a metallic transfer sheath as well as the delivery tool through this “vulnerable” artery, as is necessary when using it on the Symmetry aortic Connector. To date, the preclinical and clinical work done with the St. Jude Medical Symmetry Aortic Connector System has been limited to saphenous vein grafts only. There are differences in the mechanical and physiologic properties between vein and arterial grafts that make evaluation important. The preclinical testing of compatibility of these devices with arterial grafts should be a must before these devices are introduced into a clinical setting.With the St. Jude Medical second generation aortic connector the use of arterial grafts has been studied in an animal model (unpublished data) with acceptable results. With this new instrument, mechanical connector manipulation of the radial artery is definetively minimized, as the device is loaded from the proximal end of the artery. Therefore there is no need for the arterial graft to be skeletonized. Additionally, studies on the use of these devices in a clinical setting are important before adopting this technique for total arterial revascularization. In an effort to reduce the complication rate of coronary artery bypass surgery, all aortic manipulations have to be critically analyzed and reevaluated. The use of semiautomated anastomosis devices accomplishes the creation of an aorto-to-graft anastomosis without a side-biting aortic clamp. Watanabe et al describe the use of radial arteries instead of vein grafts for mechanical aortic graft connection with the St. Jude Medical Aortic Connector in CABG patients. Every surgeon who has used the Aortic Connector in vein grafts in the past might have thought of the possibility to use it in radial arteries or other arterial grafts also. These other surgeons were well advised not to use it yet for the radial artery, although the connector is feasible technically. The radial artery is a muscular artery and is highly at risk for vessel wall spasm, which might cause a string phenomenon. Therefore, when harvesting and storing the radial artery, exceptional care and delicate handling is mandatory to prevent spasm. It seems rather rough to pull a metallic transfer sheath as well as the delivery tool through this “vulnerable” artery, as is necessary when using it on the Symmetry aortic Connector. To date, the preclinical and clinical work done with the St. Jude Medical Symmetry Aortic Connector System has been limited to saphenous vein grafts only. There are differences in the mechanical and physiologic properties between vein and arterial grafts that make evaluation important. The preclinical testing of compatibility of these devices with arterial grafts should be a must before these devices are introduced into a clinical setting. With the St. Jude Medical second generation aortic connector the use of arterial grafts has been studied in an animal model (unpublished data) with acceptable results. With this new instrument, mechanical connector manipulation of the radial artery is definetively minimized, as the device is loaded from the proximal end of the artery. Therefore there is no need for the arterial graft to be skeletonized. Additionally, studies on the use of these devices in a clinical setting are important before adopting this technique for total arterial revascularization.

Video-assisted multivessel revascularization through a left anterior small thoracotomy approach with the Symmetry Aortic Connector System

Objective: We sought to demonstrate the applicability of video-assisted multivessel revascularization through a left anterior small thoracotomy approach with the use of the Symmetry Aortic Connector System (St Jude Medical Anastomotic Technology Group, Inc, St Paul, Minn) as an alternative to the standard median sternotomy approach and to evaluate predischarge angiographically documented graft patency. Methods: From October 2001 through February 2002, a total of 15 patients with triple-vessel disease were operated on through a left anterior small thoracotomy approach with video-assisted port-access construction of proximal aorta-to-saphenous vein anastomoses with the Symmetry Aortic Connector System and cardiopulmonary bypass with femoral cannulation and without cardioplegic arrest. There were 9 male and 6 female subjects with a mean age of 68.3 ± 3.6 years and an average ejection fraction of 55.8% ± 19.6%. Subject inclusion criteria consisted of female sex (initially but not throughout the study), coronary artery reoperations, and sternal bone disease. Subject exclusion criteria consisted of an age younger than 65 years, extensive atheromatous plaques in the ascending aorta, and aortoiliac occlusive disease. All but 1 patient underwent angiographic patency evaluation before discharge. Results: Fifteen operations were performed successfully without any deaths. Twenty-nine sutureless proximal anastomoses were performed, with an average of 3.13 ± 0.62 distal anastomoses per patient. Eleven (73%) patients underwent a fast track protocol with extubation in the operating room. We did not observe any instances of low cardiac output syndrome, stroke, renal insufficiency, wound complication, or perioperative myocardial infarction. A single episode of atrial fibrillation occurred in this group. Angiographic assessment of 44 bypass grafts and target arteries was performed, and 86% of those examined were widely patent (FitzGibbon score A). Conclusions: We have demonstrated a potential advantage of the sutureless Symmetry Aortic Connector System as a suitable approach that affords minimal access. Video-assisted multivessel revascularization through a left anterior small thoracotomy approach with an automated mechanical anastomosis device is particularly useful in patients undergoing coronary artery bypass reoperations or those at risk of poor sternal healing or infection. This approach seems to be a safe alternative to standard median sternotomy.J Thorac Cardiovasc Surg 2003;125:129-34

Thrombotic occlusion of the aortic ostia of saphenous venous grafts early after coronary artery bypass grafting by using the Symmetry aortic connector system

J Thorac Cardiovasc Surg 2002;124:397-9

The St Jude Medical symmetry aortic connector system for proximal vein graft anastomoses in coronary artery bypass grafting.

A new device designed to create proximal vein graft anastomoses to the aorta in coronary artery bypass grafting was recently developed by the St Jude Medical Anastomotic Technology Group (Minneapolis, Minn). This new anastomosis system consists of a nickel-titanium (nitinol) connector, an aortic cutter, and a delivery device. The loading of the vein on the aortic connector and its delivery to the aorta are described. In 43 consecutive patients (mean age 68 +/- 10 years, age range 33-91 years), 65 proximal vein graft anastomoses were performed with the new system. Intraoperative flow rates were assessed for all grafts according to the transit time principle. All connector anastomoses were performed without the use of any aortic clamp. Times to complete these mechanical anastomoses were less than 10 seconds in all cases. Hemostasis was instantaneous in all cases, with only 3 system failures. These connectors were easily removed so that the anastomoses could be performed with standard suturing technique through the same aortotomy without complications. All vein grafts were patent at the end of the procedure, and there were no intraoperative or postoperative complications related to the device. The aortic connector system was easy to handle and allowed quick creation of reliable, reproducible, and uniform anastomoses. In addition, anastomoses could be done without any clamping of the aorta, which is especially attractive for off-pump procedures, because aortic manipulation and therefore the risks of embolism and aortic dissection would be further minimized. In on-pump cases this technique would facilitate the single-clamp technique, again minimizing aortic manipulation.

Minimizing aortic manipulation during OPCAB using the symmetry aortic connector system for proximal vein graft anastomoses

Background. Since minimal invasive techniques have become increasingly common in coronary artery bypass grafting (CABG), there has been renewed interest in facilitated mechanical anastomoses devices that might have the potential of replacing the standard suturing techniques in vascular anastomoses. We report our initial experience with the successful creation of mechanical proximal vein graft anastomoses in off-pump coronary artery bypass operations. Methods. From August to December 2000, we investigated the first 20 consecutive patients who underwent CABG on the beating heart without extracorporeal circulation and who received at least one mechanical proximal vein graft anastomosis with the St. Jude Medical Symmetry aortic connector system without side-clamping of the aorta. We evaluated the different components of the system, the feasibility of such anastomoses, and the intraoperative flow measurements of the grafts using transit time methods. Results. A total of 32 proximal vein graft anastomoses were performed with the aortic connector system. Hemostasis was instantaneous in all cases except one, in which the connector was removed and the anastomosis was hand-sewn without complications. All other vein grafts were patent at the end of the procedure; intraoperative flow measurements were 39 ± 25 mL/min for single vein grafts (n = 20) and 69 ± 25 mL/min for sequential grafts (n = 11). Conclusions. The St. Jude Medical Symmetry aortic connector system is a user-friendly, effective, quick, and reliable device for sutureless proximal vein graft anastomosis in CABG. This system allows the construction of uniform and geometrically perfect anastomoses and does not require aortic side-biting. This technology is attractive for all CABG procedures because aortic manipulation is reduced. In off-pump surgical procedures the connector system allows aortic manipulation to be minimized, potentially reducing embolization from aortic wall debris.