Evaluation of a new device for quick sutureless coronary artery anastomosis in surviving sheep

Light-Activated Vascular Anastomosis

Background. There have been few advances in technique since vascular anastomosis was performed with silk suture on a curved needle in 1902. This technique results in disruption of the endothelium with exposed intraluminal suture, both of which may lead to thrombocyte aggregation, intimal hyperplasia, and vascular stenosis. A variety of alternative techniques have been explored, with limited success. Photochemical tissue bonding (PTB) is a light-activated methodology of rapidly cross-linking tissue interfaces at the molecular level. Herein, we describe a new technique for anastomosis of venous interposition graft in an ovine model of femoral artery bypass utilizing PTB. Methods. Polypay specific pathogen free sheep (n = 5; 40-45 kg) underwent femoral artery bypass utilizing saphenous vein. The femoral artery was transected and reversed saphenous vein was implanted as an interposition graft. The proximal anastomosis was created as a vein-over-artery cuff utilizing PTB, and the distal anastomosis was created with standard interrupted 8-0 polypropylene suture. Four weeks post-index operation, femoral angiogram was performed to evaluate patency, tortuosity, and luminal diameter. All bypass grafts were harvested and longitudinal and transverse histological sections from the proximal anastomosis were analyzed. Results. The PTB anastomoses (n = 5) were immediately watertight and patent. All animals survived the 28-day study duration. Angiography revealed patent grafts with no aneurysm or stenosis (n = 5). Histologic examination revealed integration of the venous endothelium with the arterial adventitia. Conclusion. Photochemical tissue bonding creates an immediate strong, watertight vascular anastomosis that can withstand physiologic arterial pressure and remains patent at 28 days without the need for intraluminal suture.

A systematic review of sutureless vascular anastomosis technologies

Vascular anastomoses typically involve a handsewn technique requiring significant surgical training, expertise, and time. The aim of our systematic review was to identify and describe sutureless vascular anastomosis techniques. We performed a systematic review of all sutureless vascular anastomosis technologies published in MEDLINE, PubMed, Embase, CINAHL, Cochrane, Web of Science, and Scopus Library databases and a patent review using US Patent and Trade Office Application, US Patent and Trademark Office Patent, Google Patents, Lens, Patent Quality Through Artificial Intelligence, SureChEMBL, and E-Space Net. Data from inclusion studies and patents published between January 1, 1980 and July 15, 2021 were abstracted to describe their category, anastomosis type and configuration, study types, and advantages and disadvantages encountered with each technology. Two hundred eleven original studies and 475 patents describing sutureless vascular anastomosis technologies were identified. In the literature, stents/stent-grafts/grafts (n = 61), lasers (n = 53), and couplers (n = 27) were the predominant device categories. In the patent review, adhesive technologies (n = 103), stents/stent-grafts/grafts (n = 68), and mechanical connectors (n = 61) predominated. The majority of studies involved in vivo animal studies (n = 193); 32.2% (n = 68) of investigations involved human trials; and 17.9% (n = 85) of patent technologies were approved by the US Food and Drug Administration. The main advantages described for sutureless anastomosis technologies included faster procedure time and greater patency rates compared with handsewn anastomoses. The main disadvantages included reduced vessel compliance, stenosis, leakage, and device costs. The appeal of sutureless technology is substantiated by numerous animal trials, but their use in humans remains limited. This may be a reflection of strict regulatory criteria and/or vascular complications associated with currently available technologies.

A different technique for sutureless coronary bypass grafting

Introduction

Many coronary anastomotic devices have been designed to replace manual stitching in coronary surgery; however, interestingly, none of them became widespread. Our aim was to work out an easy and fast endoluminal vessel-to-vessel stent bridge distal anastomotic technique.

Materials and methods

Ten coronary arteries of eight fresh human hearts were used in this study. The anastomosis was performed with the implantation of a graft vessel into the lumen of the coronary artery by performing stent fixation. The technique is described and photo documented in detail. The durability and the conductibility of the anastomosis were examined with intraluminal endoscopy, functional streaming test, and a coloring of the vessels.

Results

The anastomosis had great results in all cases. Obstruction, dissection, or dislocation of the vessels was not observable.

Conclusions

This study confirmed the ex-vivo feasibility of the described technique. This method can be an easy, fast, and reliable method applied in the endoscopic distal coronary artery anastomosis surgery. The development of stents adapted to this method and the in-vivo testing of this technique are necessary for the future.

ConVes: The Sutureless Aortic Graft Anastomotic Device

PURPOSE

Less invasive left ventricular assist device implantation became feasible with the development of smaller devices. This study evaluated a sutureless aortic anastomosis device to facilitate the implant procedure.

DESCRIPTION

The novel anastomotic device deploys and anchors an acute-angled stent in the aortic wall to create a sutureless outflow graft anastomosis in the ascending aorta. Four aortic anastomoses were performed on the beating hearts of two pigs without cross-clamping or cardiopulmonary bypass.

EVALUATION

The procedure was fast and simple. The time of anastomosis averaged 8.1 minutes, with merely oral instructions to the operating surgeon. The design of the stent allowed the outflow graft to be implanted with the intended angulation of 45 degrees.

CONCLUSIONS

This proof-of-concept study demonstrates the feasibility and short-term success of the proposed sutureless anastomotic device. Further preclinical studies are necessary to evaluate long-term durability of the anastomosis.

Sutureless microvascular anastomosis assisted by an expandable shape-memory alloy stent

Vascular anastomosis is the highlight of cardiovascular, transplant, and reconstructive surgery, which has long been performed by hand using a needle and suture. However, anastomotic thrombosis occurs in approximately 0.5-10% of cases, which can cause serious complications. To improve the surgical outcomes, attempts to develop devices for vascular anastomosis have been made, but they have had limitations in handling, cost, patency rate, and strength at the anastomotic site. Recently, indwelling metal stents have been greatly improved with precise laser metalwork through programming technology. In the present study, we designed a bare metal stent, Microstent, that was constructed by laser machining of a shape-memory alloy, NiTi. An end-to-end microvascular anastomosis was performed in SD rats by placing the Microstent at the anastomotic site and gluing the junction. The operation time for the anastomosis was significantly shortened using Microstent. Thrombus formation, patency rate, and blood vessel strength in the Microstent anastomosis were superior or comparable to hand-sewn anastomosis. The results demonstrated the safety and effectiveness, as well as the operability, of the new method, suggesting its great benefit for surgeons by simplifying the technique for microvascular anastomosis.

A systematic review of the safety and efficacy of distal coronary artery anastomotic devices

Interest in minimally invasive and off-pump cardiac surgical techniques has promoted the development of automated distal anastomotic devices (DADs) to facilitate construction of coronary artery anastomosis. Several DADs have been proposed for potential use in coronary surgery. However, a number of technical failures and uncertainty around both short-term morbidity and long-term patency have limited the generalized uptake of these devices. A systematic literature search identified 28 studies, incorporating 970 patients who underwent coronary artery bypass grafting using a DAD. Eight different devices were identified including Heartflo, St Jude, U-clip, vessel closure system, C-port, magnetic vascular positioner and coronary anastomosis coupler. Thirty-day mortality, cardiac-specific mortality and myocardial infarction were equal between DADs and hand-sewn cases (1.3, 0.3 and 0.8%, respectively). The overall proportion of postoperative haemorrhage was higher in the anastomotic device group (2.3%) than in the group with hand-sewn anastomoses (1.5%) although not statistically significant. Overall graft patency was 97.2% at <1 month, 94.6% at 1-3 months and 92.3% at >3 months. Of the currently available systems, the U-clip device was found to provide the best overall postoperative outcomes, which included a patency of 96.1% at >3months. The current literature is limited by its predominantly observational study design and lack of directly comparative studies. Furthermore, inter-study variation in patient selection, anticoagulation strategies and follow-up periods prevents quantitative comparison. Future research necessitates multicentre randomized, controlled studies to provide a direct comparison of current and future anastomotic device systems with established hand-sewn techniques in both the short and long term.

The vascular connector, design of a new device for sutureless vascular anastomosis

BACKGROUND

In recent years, several methods and new techniques have been studied and proposed for establishment of sutureless vascular anastomoses, streaming use of sutureless vascular surgery in the future.

PRESENTATION OF THE HYPOTHESIS

The new vascular connector (NVC) is a hypothetical design of a vascular device, proposed for creation and maintenance of sutureless vascular anastomosis. Implication of NVC would introduce a new device and technique in establishment of sutureless vascular anastomosis in which surgical approach is minimized and so post-operation disorders. It would eliminate need for suture; shorten clampage and operation time, consequently reducing stress for both, the surgeon and the patient. It enables the creation of vascular anastomosis fast, simple, safe, reliable, with satisfactory patency and stability of anastomosis.

TESTING THE HYPOTHESIS

Efficacy of NVC needs to be evaluated in further studies, in order to be confirmed for clinical use. The effectiveness of NVC should be verified firstly in vitro and in vivo tests; and by animal experiments. The likelihood of its negative influence in thrombogenicity should be well evaluated.

IMPLICATIONS OF THE HYPOTHESIS

Implication of the new vascular connector (NVC) would be of interest to both patients and the surgeon due to the following main achievements: 1) enables the creation of vascular anastomosis fast and simple, 2) significant shortening of clampage time of blood vessels and operation time-this assumption would be followed by reduced risk of operative and post-operative complications and length of hospital stay or admission to Intensive care unit, 3) safe and reliable, 4) compatible with any blood vessel and standard vascular graft, 5) using the NVC we will reduce in minimum need for replaced blood volume, 6) reduces the cost of treatment. It is anticipated that the NVC would provide shorter operation time and least operative and post-operative complications in creation of sutureless vascular anastomosis.

Stent-and-glue sutureless vascular anastomosis

Vascular anastomosis is commonly done by hand-sewn methods which not only are slow in pace, but also need experiences in surgeons' hands. As the old techniques are replaced by the new ones all the time, it is sensed that a new sutureless approach should be welcomed in the field of vascular anastomosis. Although lots of efforts have been done, such previous recommended techniques are associated with adverse consequences and here is where the need for new methods is still sensed. In this manuscript, we bring all the benefits from other methods together and conclude a novel one for end-to-end vascular anastomosis which uses biological glue as connecting material and also an absorbable stent to keep vessel patency while using balloon catheter and tacking suture.

BioWeld® Tube and surgical glue for experimental sutureless venous microanastomosis

Background

The medial wall of mammalian veins is generally thin and fragile compared with the thick muscle seen in arteries. This makes venous microanastomoses time consuming and challenging. This study aimed to determine the feasibility and effectiveness of using the BioWeld® Tube in conjunction with a surgical glue (butyl-2-cyanoacrylate) in performing sutureless venous microanastomoses.

Methods

The feasibility and effectiveness of microvascular anastomoses in a rabbit jugular vein model were investigated in six animals, using the BioWeld® Tube in conjunction with butyl-2-cyanoacrylate surgical glue. Patency and tissue repair mechanisms at the anastomotic site were assessed 1 week after the procedure.

Results

All anastomoses remained patent at 1 week. Muscle necrosis occurred only in areas where the tissue was subject to the fold-and-bond procedure.

Conclusion

The study showed the feasibility and short-term effectiveness of the BioWeld® Tube in facilitating venous anastomoses.

Hemodynamic Performance of a Sutureless Anastomosis Device (the Graft Connector): A Numerical Study

Sutureless anastomosis devices have been developed to facilitate arterial bypass surgery on the beating heart. However, these devices can significantly alter the hemodynamics at the end-to-side anastomosis and in the host artery, leading to the formation of thrombus or/and intimal hyperplasia (IH). In this study, a numerical analysis was performed on the hemodynamic performance of the Graft Connector (GC), a sutureless anastomosis device, under pulsatile flow conditions. The results showed that blood flow was severely disturbed in the GC model with the formation of vortices and flow stagnation at the bed and the toe, and distal to each of the stent struts, which led to low wall shear stresses and high oscillating shear indices in these regions. This may cause severe IH in the host artery and compromise the performance of the device. Based on the numerical study, suggestions were proposed for the design of the GC to improve its performance.

Sutureless nonocclusive bypass surgery in combination with an expanded polytetrafluoroethylene graft. Laboratory investigation

OBJECT

Cerebral aneurysms that cannot be treated by clip or coil placement can be treated with high-flow bypass surgery using techniques such as the excimer laser-assisted nonocclusive anastomosis (ELANA). To simplify the technique, a sutureless ELANA (SELANA) was developed in combination with an expanded polytetrafluoroethylene (ePTFE) graft.

METHODS

In 18 rabbits a bypass was constructed on the abdominal aorta using the SELANA technique with an ePTFE graft, resulting in 18 bypasses and 36 anastomoses. Short-term effects were analyzed in the first 2 weeks and at 2 and 3 months after the procedure. Patency was evaluated using quantitative ultrasound flowmetry. The anastomotic sites were studied using scanning electron microscopy.

RESULTS

Construction of the bypass using the SELANA technique was easier and faster (15-25 minutes) compared with bypasses made with the ELANA technique (> 90 minutes). At the end of follow-up, 16 of 18 bypasses were patent. Of 36 SELANA anastomoses, 32 could be completed without short temporary occlusion of the recipient vessel. Scanning electron microscopy showed complete coverage of all anastomoses with neointimal repair tissue after 10 days.

CONCLUSIONS

The SELANA technique provides further advantages over the conventional ELANA technique in ease of use and shortening of procedure time. The patency rate in this series was 89% and neointima repair tissue at the anastomosis site was complete after 10 days. Further experimental studies of the long-term patency and safety of this technique are necessary before clinical application.

Vein graft anastomoses with magnets

BACKGROUND

Performing vascular anastomoses requires complete circumferential access and is time-consuming and technically challenging. The purpose of our study was to assess a sutureless magnetic device for anastomosing vein grafts.

METHODS AND RESULTS

Oval magnets with a lumen were placed in six male foxhounds. The femoral artery was ligated and an 8 cm length of femoral vein was harvested and reversed. After a 4 mm venotomy or arteriotomy, one magnet was inserted into each vessel lumen and a second magnet was placed outside the vessel but aligned directly over the intraluminal magnet, forming a magnetic port in each vessel. The graft and target vessels were then allowed to self-align and seal, creating a side-to-side anastomosis. Patency was confirmed with duplex Doppler ultrasound scans after 6 and 13 weeks and during explantation after 14 weeks. At that time, the contralateral femoral vein was harvested and an acute graft was created as a control. Macroscopically there was no sign of stenoses or aneurysms. After explant, saline was perfused through all grafts and the hydrodynamic resistance was quantified. There was no significant difference in resistance between the acute and 14-week grafts indicating stenosis. Microscopic examination of 14-week anastomoses showed that all blood-contacting surfaces were well-endothelialised.

CONCLUSIONS

The magnetic vascular coupler allowed sutureless anastomoses between blood arteries and veins. This device might prove useful for anastomosis of large and small vessels, as well as for anastomosis or approximation of non-vascular structures such as peripheral nerves, fallopian tubes or ureters.

Early clinical results with a magnetic connector for distal coronary artery anastomoses

PURPOSE

The main goals in the development of an anastomotic device are to reduce the invasiveness of the procedure and to improve graft patency. We analyze our preliminary clinical experience with the Ventrica magnetic vascular positioner (MVP) series 6000 system.

DESCRIPTION

Eighteen distal anastomoses were performed in 11 patients using the MVP.

EVALUATION

The target artery for MVP was left anterior descending in 9 patients, a marginal branch in 4, the first diagonal branch in 3, and the right coronary artery in 2. Graft material was the left internal thoracic artery in 9 patients, saphenous vein in 6, the right internal thoracic artery in 2, and the radial artery in 1 case. Fifteen anastomoses were performed in an end-to-side and 3 in a side-to-side fashion. Predischarge angiography was performed in 10 of 11 patients. There was a patent MVP anastomosis in all patients.

CONCLUSIONS

Distal anastomoses using the MVP were performed successfully in all patients. The procedure is simple. Short-term patency is excellent. Further randomized trials are necessary to determine long-term safety and patency.

Anastomotic devices for coronary surgery

Proximal and distal anastomotic devices will play different roles in advancing minimally invasive cardiac surgery. In the wake of the first experiences with the St. Jude Symmetrytrade mark, data will be needed to support new technology adoption. The value of anastomotic technology will be greater in the off-pump and small access coronary techniques. When coronary vascular connectors provide the same or better patency than suture cardiac surgeons will use them for most cases because they will be faster and more reliable. This burgeoning field of anastomotic connectors is already beginning to spill over into other specialties. There is promise for these devices in vascular procedures. It is predicted that similar devices will also be used for bowel anastomoses. With continued evolution of anastomotic devices, it is easy to visualize that in the near future the majority of anastomoses may be performed with a manual or automatic device as opposed to the current conventional suture technique.

Experimental Study of Aortic Anastomosis Using a Circular Stapling Device in the Porcine Model

OBJECTIVES

The aim of this study was to assess the strength (pressure resistance) and histological findings of aortic anastomoses performed using a circular stapling device.

MATERIALS AND METHODS

A circular stapling device was used for anastomosing a porcine aorta and a Dacron graft. The maximum pressure resistance of the anastomotic site of a porcine aortic specimen and a Dacron graft was examined (n=10). A porcine aorta with Dacron graft was anastomosed to a beating heart, and pressure overload was induced by adrenaline (n=5). Specimens of the anastomotic sites were harvested after 14 days and examined histologically.

RESULTS

The maximum pressure resistance of the anastomotic site was 427.3+/-34.4 (375-511) mmHg. No anastomotic sites leaked as a result of pressure overloading at 227.6+/-21.1 (201-260) mmHg. Histologically, good incorporation and cell coverage were observed, and the inner surfaces of the anastomotic sites were smooth and without stenoses.

CONCLUSIONS

Aortic anastomosis using a circular stapling device is feasible and worthy of further investigation.

A new mechanical connector for distal coronary artery anastomoses in coronary artery bypass grafting: A randomized, controlled study

OBJECTIVE

A new mechanical anastomotic device was evaluated, aiming at its future use in minimally invasive techniques or limited access surgery in patients undergoing coronary artery bypass grafting.

METHODS

Between April and December 2002, a total of 60 patients scheduled for elective multivessel bypass grafting were randomly assigned. One vein graft-coronary artery anastomosis per patient was either performed with the St Jude Medical ATG coronary connector system (n = 30; St Jude Medical Inc, St Paul, Minn) or hand sewn (n = 30). Selective coronary angiography or coronary magnetic resonance imaging of the studied graft and vessel was included in the 6-month follow-up.

RESULTS

Twenty-eight of the connectors were successfully implanted. Two patients were excluded from the study because of conversion to hand-sewn anastomoses. Six connector-made anastomoses were bleeding at the anastomotic site. At the time of follow-up (190 postoperative days), all control anastomoses and grafts were patent, whereas 26% of the connector anastomoses were occluded. One graft in each group was patent but with stenosis.

CONCLUSION

The St Jude Medical ATG coronary connector system for distal anastomoses represents a new concept for sutureless anastomoses in cardiac surgery. This randomized, controlled study shows lower graft patency for anastomoses performed with the connector than for hand-sewn control anastomoses. It illustrates the importance of controlled studies when evaluating new technical equipment in medicine.

Initial Experience of an Automated Anastomotic Distal Device in Off-Pump CABG

BACKGROUND

Recent progress in minimally invasive technology in the field of coronary artery bypass grafting (CABG) stimulates interest in anastomotic devices used to facilitate distal coronary anastomosis. We assessed the feasibility of the automated anastomotic distal device (AADD) on arterial grafts in patients who underwent off-pump CABG (OPCAB) and evaluated the early anastomotic patency and clinical results of the AADD based on an elliptical nitinol ring with attached 8 pins.

METHODS

Fourteen patients scheduled for multivessel OPCAB using arterial grafts between August 2003 and February 2004 were studied. Among 19 patients enrolled, 5 patients were excluded: 2 patients because of failure of graft flaring onto the implant pins, 2 because of small and diseased target coronary artery (<1.5 mm in diameter), and 1 because of conversion to cardiopulmonary bypass. The distal anastomosis using the AADD was performed for the nondominant coronary artery.

RESULTS

The total number of distal anastomoses was 48 (34 hand-sewn sutures and 14 AADD sutures), and the average number of distal anastomoses per patient was 3.4 +/- 1.0. The grafts used for the AADD were right gastroepiploic artery (RGEA) in 10 patients, saphenous vein anastomosed to the end of the RGEA in 2 patients, and internal thoracic artery in 2 patients. The average time required for distal anastomosis using the AADD (from arteriotomy to anastomosis completion) was 2.9 +/- 0.7 minutes (range, 1.5-4 minutes). The mean flow and pulsatility index of the AADD grafts measured intraoperatively by transit time flow measurement were 20.0 +/- 10.3 mL/min and 2.4 =/- 1.2, respectively. Early postoperative coronary angiographies demonstrated widely patent grafts in 32 of 34 hand-sewn anastomoses and 13 of 14 AADD sutures. There were no adverse events related to the use of the device.

CONCLUSIONS

Our initial experience demonstrated that distal anastomosis using the AADD was feasible in most of the patients who underwent OPCAB using arterial grafts. Distal anastomosis using the AADD had the advantage of shortening the actual suturing duration and might provide a method for standardizing the anastomotic procedure.

Side-to-side sutureless vascular anastomosis with magnets

OBJECTIVE

Abbe and Payr introduced vascular techniques and devices to facilitate vessel anastomosis over a century ago. Obora published the idea of a sutureless vascular anastomosis with use of magnetic rings in 1978. The purpose of this study was to assess the performance of a new magnetic device to perform a side-to-side arteriovenous anastomosis in a dog model.

MATERIAL AND METHODS

Male fox hounds (25 kg) were treated preoperatively and daily postoperatively with clopidogrel bisulfate (Plavix) and aspirin. The femoral artery and vein were exposed unilaterally in 3 dogs and bilaterally in 4 dogs (n = 11 anastomoses). A 4-mm arteriotomy was performed, and 1 oval magnet 0.5 mm thick was inserted into the lumen of the artery and a second magnet was applied external to the artery, compressing and stabilizing the arterial wall to create a magnetic port. An identical venous magnetic port was created with another pair of oval magnets. When the 2 ports were allowed to approach each other, they self-aligned and magnetically coupled to complete the arteriovenous anastomosis. Patency was assessed for the first hour with direct observation, again after 9 weeks with duplex ultrasound scanning, and at 10 weeks under direct open observation. The anastomoses were explanted after 10 weeks. Hydrodynamic resistance was measured ex vivo on the final 8 anastomoses by measuring the pressure drop across an anastomosis with a known flow rate.

RESULTS

After implantation, very high flow created visible turbulence and palpable vibration. All 11 anastomoses were patent under direct observation and palpation. Ten of 11 anastomoses were clearly patent on duplex scans, and patency of 1 anastomosis was questionable. Hydrodynamic resistance averaged 0.73 +/- 0.33 mm Hg min/mL (mean +/- SEM).

CONCLUSIONS

Vascular anastomoses performed with magnets demonstrated feasibility; exhibited 100% patency after 10 weeks in a dog arteriovenous shunt model; lacked apparent aneurysm or other potentially catastrophic failure; demonstrated remodeling of the vessel wall after several weeks to incorporate the magnets, making the magnetic force unnecessary; and warrants further study in vessels with different sizes, flow rates, and locations.

CLINICAL RELEVANCE

We present a magnet-based device used to perform side-to-side peripheral vascular anastomoses. Its advantages include the ability to anastomose vessels without requiring circumferential surgical exposure. Vascular anastomosis performed with these magnets demonstrated 100% patency in the dog, lacked apparent aneurysm or other potentially catastrophic failure, and demonstrated remodeling of the vessel wall after several weeks, to incorporate the magnets, making indefinite retention of field strength unnecessary. This technique could enable minimally invasive procedures, such as complex reconstructive and revascularizing surgery, and warrants further study in vessels with different sizes, flow rates, and locations.

Clinical and angiographic results after mechanical connection for distal anastomosis in coronary surgery

BACKGROUND

Sutureless anastomotic devices are of increasing interest in cardiovascular surgery. We investigated the stainless steel clip system of St Jude Medical/Anastomotic Technology Group (Maple Grove, Minn) to connect saphenous vein grafts with coronary arteries.

METHODS

Forty-five patients were enrolled in this feasibility study performed on patients who had on-pump coronary artery bypass grafting, but 32 patients only received 1 distal anastomosis with this investigational device (2.5 mm [n = 14] and 2.0 mm [n = 18]). Thirteen were excluded because target vessels were too small, calcified, or tortuous. The system consists of an expandable clip mounted on a balloon catheter; delivery is obtained during balloon inflation. The main differences between the 2.5-mm and 2.0-mm devices are different loading and deployment in smaller coronary arteries for the 2.0-mm device.

RESULTS

A connecting device was deployed on the right coronary artery in 14 patients, the posterior descending branch in 12 patients, the obtuse marginal in 5 patients, and the posterolateral branch in 1 patient. Perfect hemostasis of the sutureless connector anastomosis was obtained in 28 patients. Three connectors were removed because of minor leakage at the connection site, and 1 connector was removed because of mismanipulation after successful deployment. Hand-sewn anastomosis was performed at the same arteriotomy site. Intraoperative flow was assessed by the transit time method and averaged 71 +/- 24 mL/min. One patient died of neurologic injury; the connector was patent at autopsy. One patient had a perioperative myocardial infarction. There was no adverse cardiac event in the remaining patients. All patients underwent clinical follow-up after 6 and 12 months and 35 angiograms were available in 21 patients: after 3 and 6 months, 17 anastomoses were patent and the saphenous vein graft was occluded in 4 patients.

CONCLUSIONS

The coronary connector system from St Jude Medical/Anastomotic Technology Group allows consistently uniform sutureless connection between the saphenous vein graft and coronary artery. Loading and deployment require careful training. This technology is under constant development and may give a significant boost to less invasive coronary revascularization techniques.

Clinical experience with devices for facilitated anastomoses in coronary artery bypass surgery

Recent developments in minimally invasive coronary artery surgery have been driven by the introduction of new technologies which should facilitate precise surgical maneuvers on the beating heart within confined spaces. Such technologies include coronary stabilizer systems, cardiac positioning vacuum-assisted devices, and telemanipulative systems. Despite these developments, standard suturing techniques using running polypropylene material remains a limiting factor in the surgeon's ability to perform complete revascularization with high quality anastomoses through minimal approaches to the chest cavity. Clinical validation of proximal and distal anastomotic devices has the potential to substantially improve and perhaps revolutionize minimally invasive coronary surgery. Ideal characteristics of such devices would include applicability to all conduit types, all coronary sizes, interchangeable proximal/distal sequencing of the anastomosis, and safe bail out for device malfunction. However there is an urgent need to define the performance objectives of such systems as well as the general criteria for proper and comparable evaluation and validation of different systems in animal models and subsequently in controlled prospective clinical studies. This review summarizes the most interesting systems available in both experimental and clinical settings.

Stapled coronary anastomosis with minimal intraluminal artifact: The S2 Anastomotic System in the off-pump porcine model

OBJECTIVE

A reliable, easy-to-use, 1-shot anastomotic device will significantly push the barrier for less invasive coronary bypass surgery. The current study was designed to test the safety, efficacy, and early patency of a novel distal anastomotic device.

METHODS

The S2 Anastomotic System (iiTech BV, Amsterdam, The Netherlands) was used in 10 consecutive pigs (73 kg) on a mild antiplatelet regimen. In each animal, the device was used to create an internal thoracic artery to left anterior descending bypass on the beating heart. The anastomoses were evaluated intraoperatively (n = 10), at 2 days (n = 2), and at 5 weeks (n = 8) by functional flow measurements, postmortem angiography, and histomorphologic examination.

RESULTS

In all pigs, the S2 Anastomotic System rapidly created successful anastomoses at the first attempt (graft loading and coronary ischemia time: 1.2 +/- 0.3 minutes and 3.0 +/- 0.6 minutes) on target vessels of 1.6 to 2 mm inner diameter. There were no technical failures or anastomotic leaks requiring additional sutures. Both intraoperatively and at the time of death, ischemically induced peak hyperemic flow responses demonstrated widely patent bypasses, which were confirmed by postmortem angiography (FitzGibbon grade A, n = 10) and macroscopic evaluation (anastomotic orifice: 2 mm). Histomorphologic evaluation showed a normal healing response with negligible neointima covering the connector and limited streamlining repair tissue formation between the staple-like elements of the connector.

CONCLUSIONS

The S2 Anastomotic System consistently created automated, fast, and reliable internal thoracic to coronary artery anastomoses on the porcine beating heart with excellent graft patency and healing characteristics at the 5-week follow-up.

Automated distal coronary bypass with a novel magnetic coupler (MVP system)

OBJECTIVE

We sought to assess the feasibility of performing sutureless distal coronary artery bypass anastomoses with a novel magnetic coupling device.

METHODS

From May 2000 to April 2001, single-vessel side-to-side coronary artery bypass grafting on a beating heart was performed in 39 domestic white pigs (35-60 kg) without the use of mechanical stabilization, shunts, or perfusion bridges. Animals were divided into 2 groups. Seventeen pigs underwent right internal thoracic artery to right coronary artery bypass grafting through a median sternotomy (group 1) with a novel magnetic vascular positioning system (MVP system; Ventrica, Inc, Fremont, Calif). Twenty-two pigs underwent left internal thoracic artery to left anterior descending artery grafting with the MVP anastomotic device through a left anterior minithoracotomy (group 2). This system consists of 2 pairs of elliptical magnetic implants and a deployment device. One pair of magnets forms the anastomotic docking port within the graft; the other pair forms an identical anastomotic docking port within the target vessel. The anastomosis is created when the 2 docking ports magnetically couple. Anastomotic patency was evaluated by means of angiography during the first postoperative week and at 1 month. Histologic studies were performed at different time points as late as 6 months.

RESULTS

Right internal thoracic artery to right coronary artery anastomoses and left internal thoracic artery to left anterior descending artery anastomoses were successfully performed with the system in all animals. The self-adherent and self-aligning properties of the implants allowed for immediate and secure approximation of the arteries (total anastomotic time between 2-3 minutes). Anastomoses were constructed without a stabilization platform. Five nondevice-related deaths occurred postoperatively. One-week angiography, performed in 35 surviving animals, showed a patent graft and anastomosis in all cases. The patency rate at 1 month was 97% (33/34). Histologic studies as late as 6 months demonstrated neointimal coverage of the magnets without any significant luminal obstruction. Histology also confirmed the presence of viable tissue between magnets.

CONCLUSION

The MVP anastomotic system uses magnetic force to create rapid and secure distal coronary artery anastomoses, which might facilitate minimally invasive and totally endoscopic coronary artery bypass surgery.

Permanent wall stretching in porcine coronary and internal mammary arteries

BACKGROUND

Anastomotic connectors may induce substantial arterial wall deformation and, hence, wall injury. We studied arterial wall damage and repair after sustained large longitudinal elongation in the porcine coronary and internal mammary arteries in vivo.

METHODS

A stretch device that elongates a part of the artery by 80% was implanted in 8 pigs. Elongated coronary arteries (n = 14) and internal mammary arteries (n = 15) were examined histologically at either 2 days (4 pigs) or 5 weeks of follow-up (4 pigs).

RESULTS

No mural thrombus was observed at the elongated site. In the coronary artery at 2 days, few and only minor histologic changes were found. At 5 weeks, in two of seven coronary segments, a thin rim of intimal hyperplasia was found, in one case with a maximum thickness of 76 micro m. The internal mammary artery hardly showed any changes.

CONCLUSIONS

Permanent longitudinal elongation by 80% caused little structural changes in the porcine coronary and internal mammary artery wall. Anastomotic connectors that impose relatively large deformations can be safely evaluated in the pig.

Mechanical properties of porcine and human arteries: implications for coronary anastomotic connectors

BACKGROUND

To determine whether the pig is an appropriate experimental animal for studies on distal anastomotic connectors in coronary artery bypass surgery, the mechanical properties of young porcine and old human coronary and internal mammary arteries were compared within and beyond the physiologic range of strains.

METHODS

Coronary arteries from 6 humans and 8 pigs were studied as well as internal mammary arteries of 3 humans and 6 pigs (human, aged 61 to 85 years; pig, 78.7 +/- 5.8 kg [mean +/- SD]). Pressure-diameter, pressure-axial force, circumferential and axial stress-strain relations, and dimensions were measured.

RESULTS

The dimensions of the porcine and human coronary and internal mammary artery were generally similar but wall thickness was smaller in the porcine internal mammary artery (0.35 +/- 0.07 mm versus 0.71 +/- 0.06 mm, respectively, p = 0.002). The porcine internal mammary artery wall was less elastic than the coronary artery wall, whereas in humans both arteries displayed similar elasticity. Overall the porcine arteries were far more elastic in both circumferential and axial direction compared with the human arteries. Consequently the porcine arteries could be safely stretched by 60% to 70% compared with about 20% for the human arteries before reaching their maximum circumferential strain.

CONCLUSIONS

The three times greater elasticity of porcine compared with human coronary and internal mammary artery walls may result in underestimation of wall stress and the risk of wall injury when coronary connectors that involve overstretching of the wall are evaluated in the pig.

Coronary anastomotic devices: blood-exposed non-intimal surface and coronary wall stress

OBJECTIVE

This study compares the area of blood-exposed non-intimal surface in device-constructed anastomoses with the conventionally sutured anastomosis and examines the technical feasibility of 0 blood-exposed non-intimal surface anastomosis configurations.

METHODS

In the device-constructed anastomosis, blood-exposed non-intimal surface was estimated in all anastomosis configurations identified in truly new (ie, nonduplicate and nonrelated) patent applications and in anastomotic devices recently introduced by several institutions. In the sutured anastomosis, blood-exposed non-intimal surface area was estimated by analysis of previously investigated anastomoses. In 0 blood-exposed non-intimal surface anastomosis configurations, finite element modeling was used to calculate coronary wall stress.

RESULTS

By the end of 2001, 57 truly new applications for the distal coronary anastomosis had been published, categorized in 11 types of anastomosis configurations. The tissue blood-exposed non-intimal surface area (ie, non-intimal tissue surface area) ranged from 0 to 6 mm(2). Approximate total blood-exposed non-intimal surface areas (ie, sum of tissue blood-exposed non-intimal surface and foreign body surface area) in recent devices are 80 mm(2) (GraftConnector, Jomed, Helsingborg, Sweden); 33 mm(2) (Magnetic Vascular Positioner rings, Ventrica, Inc, Fremont, Calif); 4.3 mm(2) (distal connector of St Jude Medical, Inc, St Paul, Minn); and 0.3 mm(2) (Crinoline frame, University Medical Center Utrecht/Delft University of Technology, The Netherlands). The sutured anastomoses, in contrast, contained approximately 1.3 mm(2) blood-exposed non-intimal surface area. The mean peak porcine coronary wall stress in 0 blood-exposed non-intimal surface anastomosis configurations with greater than 90 degrees arteriotomy edge eversion ranges from 0.4 to 0.8 N/mm(2) compared with the mean porcine coronary tear stress of 0.8 N/mm(2).

CONCLUSIONS

In recently introduced devices for clinical use, the total blood-exposed non-intimal surface area ranges from 4.3 to 80 mm(2) compared with 1.3 mm(2) in sutured anastomoses. The blood-exposed non-intimal surface area depends on anastomotic orifice size, wall thickness, and bonding components' location and size. Deforming the coronary wall to most of the 0 blood-exposed non-intimal surface anastomosis configurations leads to dangerously high stress concentrations in the coronary arteriotomy corners.

Initial experience with proximal anastomoses performed with a mechanical connector

BACKGROUND

The Symmetry Bypass System Aortic Connector (St Jude Medical, Inc) is a novel device for the construction of sutureless proximal anastomoses. The connector allows attachment of saphenous vein grafts to the aorta without requiring aortic clamping. We report our initial clinical experience with this device.

METHODS

In a 2-month period from May to July 2001, a total of 139 consecutive proximal anastomoses were performed in 67 patients using the connector. All procedures were performed on a beating heart without cardiopulmonary bypass or any aortic clamping. Intraoperative variables and postoperative results were prospectively collected and retrospectively analyzed.

RESULTS

Of 139 consecutive proximal anastomoses 138 (99.3%) were successfully completed with the device. One anastomosis required suture revision because of misdeployment. Six anastomoses (4.3%) required an additional suture for leak. Predeployment problems included connector loading/preparation malfunction in 10 grafts (7.2%), five because of human error and five technical failure. There was no operative mortality, perioperative myocardial infarction, or stroke. Vessels bypassed included the circumflex system (n = 59), right coronary artery and branches (n = 48), diagonal branch (n = 26), and left anterior descending coronary artery (n = 6). At a mean follow-up of 7 months, survival was 94.1% and survival free of major adverse cardiac and cerebrovascular events (MACCE) was 88.1%.

CONCLUSIONS

Initial clinical experience with a sutureless proximal saphenous vein graft to aorta anastomosis performed with a mechanical connector demonstrates safety, reliability, and ease of use. Surmounting a brief learning curve improves the subtleties of device loading and deployment. Further benefits will be determined in an ongoing randomized study.

Non-suture methods of vascular anastomosis

BACKGROUND

The main aim of performing a vascular anastomosis is to achieve maximal patency rates. An important factor to achieve that goal is to minimize damage to the vessel walls. Sutures inevitably induce vascular wall damage, which influences the healing of the anastomosis. Over time, several alternatives to sutures have become available.

METHODS

A Medline literature search was performed to locate English, German and French language articles pertinent to non-suture methods of vascular anastomosis. Manual cross-referencing was also performed and many historical articles were included.

RESULTS AND CONCLUSION

The non-suture techniques can be categorized into five groups based on the materials used: rings, clips, adhesives, stents and laser welding. With all these techniques a faster and less traumatic anastomosis can be made compared with sutures. However, each device is associated with technique-related complications. As a consequence, suturing continues to be the standard approach. The disadvantages of the non-suture techniques include: rigidity and a non-compliant anastomosis with rings; toxicity, leakage and aneurysm formation with adhesives; early occlusion with stents; cost, reduced strength in larger-sized vessels and demand for surgical skills with laser welding. Further refinement is needed before widespread adoption of these techniques can occur. Clips, however, may be particularly promising but long-term evaluation is required.

Assessment of an aortosaphenous vein graft anastomotic device in coronary surgery: clinical experience and early angiographic results

BACKGROUND

Until now technologic evolution in coronary bypass surgery has focused on extracorporeal circulation, on operation without extracorporeal circulation, and on the exposure of the operative site. Recently a one-shot anastomotic device for the proximal anastomosis in coronary surgery was developed. We investigated whether the use of the aortic connector system (ACS) could facilitate the creation of aortosaphenous vein graft anastomoses in myocardial revascularization.

METHODS

From November 2000, 40 ACS devices were used in 36 consecutive patients (mean age 70.7 +/- 8.9 years); 12 patients (33.3%) underwent surgery on pump and 24 patients (66.6%) off pump; 50 distal anastomoses were performed. In all cases the connection with the ascending aorta was created before the distal anastomoses because of the necessity to slide the saphenous vein graft (SVG) over the vein transfer sheath. Intraoperative graft function was tested measuring blood flow by Doppler analysis. Postoperative evaluation of the anastomotic patency was carried out by early angiography in 34 patients (94.7%) but was excluded in 5 patients (5.3%) with extensive extracardiac vascular occlusive disease.

RESULTS

Of 38 AC (95%) evaluated, 36 (94.7%) functioned properly. The end-to-side proximal anastomosis without aortic clamping is instantaneous, the quality of anastomoses was highly rated, no additional stitches were required, and all coronary arteries could be reached. Intraoperative quantity flow was measured by Doppler analysis and all but one showed good flow. Early postoperative angiography demonstrated good patency of the grafts in all cases but 2 (5.3%). At 1-year follow-up, 1 patient died of stroke; all other patients remained free of symptoms and no reoperation was required.

CONCLUSIONS

The use of ACS makes end-to-side anastomosis rapid, effective, and reproducible while eliminating aortic cross clamping; it opens a new era in beating or nonbeating coronary surgery. Long-term results are mandatory to confirm our favorable preliminary results.

The Heartflo device for distal coronary anastomoses: clinical experiences in 60 patients

BACKGROUND

The Heartflo anastomotic device automates the suturing process with simultaneous delivery of 10 standard polypropylene sutures through the graft and the coronary vessel wall to construct the anastomosis. We performed clinical testing in 60 patients undergoing coronary artery bypass grafting.

METHODS

One automated distal coronary anastomosis was initially placed in each patient, the other anastomoses were created with standard running sutures. After a "flat foot"-shaped prototype was deployed in 30 patients (group I), the design of the foot was modified and deployment of the new device performed in the next 30 patients (group II).

RESULTS

In group I, automated anastomoses were completed in 16 patients (53%) using 1.7 +/- 1 additional stitches. In 26 group II patients (86%), a hemostatic anastomosis using 1.2 +/- 1 additional stitches was achieved. Anastomoses were completed in 19.0 +/- 3 minutes in group I and in 15.6 +/- 2 minutes in group II.

CONCLUSIONS

We have shown the feasability of coronary anastomoses using the Heartflo device. The modified version improved tissue capture, resulting in a higher rate of completed anastomoses. Because anastomotic time is still prolonged, an easier suture management is mandatory in the next developmental step.

Two generations of the St. Jude Medical ATG coronary connector systems for coronary artery anastomoses in coronary artery bypass grafting

BACKGROUND

In the past, coronary anastomoses have been performed using running and, occasionally, interrupted non-resorbable sutures. Recently, special interest has developed in mechanical anastomotic devices to facilitate minimal invasive techniques or limited access surgery. The experience with two series of patients undergoing coronary artery bypass grafting (CABG) using the St. Jude Medical ATG coronary connector systems (investigational stainless steel device, not yet commercially available) for vein-to-coronary artery anastomoses is reported here.

METHODS

Between November 2000 and April 2002, we evaluated two generations of distal coronary connector systems in 19 patients who were scheduled for multivessel CABG. One vein graft-to-coronary artery anastomosis per patient was performed with a stainless steel mechanical connector, in an ongoing investigational study. Although these two generations of the St. Jude Medical ATG coronary connectors have the same underlying construction, somewhat cumbersome loading of the first-generation system led to simplification of the second-generation system, which is currently evaluated.

RESULTS

With the first generation of distal connector, hemostasis was instantaneous in all cases, and all anastomoses were patent at the end of the procedure. However, retrograde flow to the native coronary artery was restricted in 1 patient. The connector was removed, and the anastomosis was performed with a running suture at the same site. Three-month angiography or magnetic resonance imaging angiography was available in 11 patients with 10 patent connector grafts. With the second-generation connectors one of five had to be removed because of leakage, and the anastomosis could be sutured at the same site. The other four connector anastomoses were patent and hemostatic at the end of the procedure.

CONCLUSIONS

The St. Jude Medical ATG coronary connector system is an effective device for sutureless vein graft to coronary artery anastomoses in CABG. The second-generation system presents a further development eliminating some drawbacks of the first generation such as cumbersome, time-consuming loading as well as suitability for smaller coronary arteries. These connectors allow construction of geometrically round anastomoses and theoretically may also be suitable for sequential anastomoses. After tremendous research and development efforts, an optimized mechanical connection system for small vessel anastomoses has been introduced into clinical investigation. This represents a major step in the era of sutureless vascular connections in cardiac surgery.

Coronary end-to-side sleeve anastomosis using adhesive in off-pump bypass grafting in the pig

BACKGROUND

In the exploration of facilitated coronary anastomosis strategies, we assessed a new octylcyanoacrylate adhesive in combination with a modified end-to-side sleeve anastomosis in off-pump bypass grafting in the pig.

METHODS

Sleeve-adhesive anastomoses (n = 20) were evaluated intraoperatively, at 3 days (n = 4), and at 5 weeks (n = 16) in an off-pump, low (< or = 15 mL/min; n = 10) and high flow (approximately 60 mL/min; n = 10) porcine bypass model. All anastomoses were examined by flow measurement, angiography, and histology.

RESULTS

Anastomosis construction took 8.5 minutes (6.7 to 10.2 minutes; median [15th to 85th percentile]). At 5 weeks, all anastomoses were fully patent (FitzGibbon grade A). The adhesive did not cause impaired vessel wall healing, but was surrounded by a focal acute and limited chronic (foreign body giant cells occasionally seen) inflammatory reaction at the adventitial application site.

CONCLUSIONS

Octyl-cyanoacrylate tissue adhesive combined with end-to-side internal mammary to coronary artery sleeve anastomosis construction proved to be feasible, even in low bypass graft flow conditions (< or = 15 mL/min; prothrombotic milieu) in the pig and deserves interest in exploration of facilitated anastomosis strategies in coronary artery bypass grafting.

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

OBJECTIVES

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.

METHODS

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.

RESULTS

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.

CONCLUSIONS

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.

Facilitated vascular anastomosis in coronary bypass surgery

The goal of truly minimally invasive surgical revascularization with 1-day hospital stays is shared by surgeons, patients, and payors alike. However, accomplishing this will involve doing surgery through more limited-access incisions and working within closed spaces. Suture management in this setting is cumbersome, slow, and unreliable. Facilitated anastomotic techniques and technologies are generally believed to be the vehicle that will ultimately allow us to address this. A considerable amount of time and resources has already been expended by many people and companies in this effort, with early clinical progress now being reported. Much more remains to be done, and other new approaches still need to be investigated. This article provides an overview or snapshot of the work and progress to date with facilitated vascular anastomoses along with some of the challenges that have yet to be solved. The achievement of a predictable, reproducible, and reliable technique to accomplish this will significantly and irrevocably reduce the extent of surgery required to revascularize the heart.

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.

Is the GraftConnector a valid alternative to running suture in end-to-side coronary arteries anastomoses?

BACKGROUND

An animal study was carried out to compare long-term patency rates of coronary anastomoses performed with the GraftConnector versus running suture technique.

METHODS

10 sheep, 45 to 55 kg, underwent off-pump coronary artery bypass grafting (right internal mammary artery to left anterior descending artery). In 5 animals, the anastomosis was performed with a GraftConnector and in 5 animals with 7-0 running suture. Intraoperative fluoroscopy and a fluoroscopic control at 6 months were performed. After 6 months, the animals were sacrificed and the anastomoses were examined histologically.

RESULTS

All animals survived at 6 months with 100% anastomosis patency rates in both groups. In the GraftConnector group, the anastomosis diameter at 6 months fluoroscopy was 118% of native left anterior descending artery versus 97% of the control group. Luminal anastomotic width at histology was 1.7 +/- 0.2 mm in the device group versus 1.6 +/- 0.1 mm in the control group. Mean intimal hyperplasia thickness was 0.21 +/- 0.1 mm in the device group versus 0.01 mm in the control group.

CONCLUSIONS

The GraftConnector provides a consistent and reproducible coronary artery anastomosis and reduces technical demand and manual dexterity in coronary operations. Long-term results demonstrate that off-pump coronary artery bypass grafting performed with the GraftConnector had the same patency rate and luminal width as those performed with running suture.

Coronary anastomotic devices: theory and patented ideas on micromechanical fastening

Coronary anastomotic devices are being designed to reduce the laborious, complex suturing approach to endoscopic coronary surgery. An anastomotic device should be safe and reliable, it should allow full view of the vessel parts to be bonded, it must provide a simple and rapid deployment, and should be hemodynamically adequate. Three anastomotic device categories found in the (patent) literature are discussed that use micromechanical fastening techniques. First, devices using individual bonding elements; second, devices using bonding elements anchored to extra-luminal frames; third, devices using an internal frame, often a stent-like structure. Anastomotic devices described in the (patent) literature to date fail to meet all requirements for endoscopic coronary application.