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

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.

Total Arterial Minimally Invasive Direct Coronary Artery Bypass Surgery Facilitated by the Trinity Clip Connector

OBJECTIVE

This pilot study evaluated the feasibility of total arterial minimally invasive direct coronary artery bypass surgery by using the Trinity Clip anastomotic connector in an acute porcine model.

METHODS

In 3 pigs, the left and right internal thoracic arteries (LITA and RITA) were harvested conventionally and the chest closed subsequently. After a left lateral thoracotomy, the coronary target was positioned and stabilized by an endo-starfish and octopus. A free RITA-to-LITA y-graft, with a LITA-to-left anterior descending coronary artery (LAD) and a free RITA-to-obtuse marginal or posterolateral or posterior descending artery, was constructed using the Trinity Clip. Patency was assessed with angiography (n = 3 anastomoses).

RESULTS

The anastomotic procedure was feasible via a small lateral thoracotomy, with a fast construction of the y-graft, and successful application of the mounted complex (ie, graft, connector, and laser, temporarily fixated by a fixation clip) onto the LAD. Access to the obtuse marginal artery, posterolateral artery, and posterior descending artery was possible, with successful construction, resulting in patent anastomoses.

CONCLUSIONS

This experimental pilot study demonstrates the feasibility of the anastomotic technique in a total arterial minimally invasive direct coronary artery bypass approach. Revascularization of the anterior, lateral, and inferoposterior regions of the heart is possible. However, visibility during the introduction of the connector was limited, and videoscopic assistance is essential to allow for successful construction. The anastomotic technique has potential to facilitate minimally invasive coronary bypass surgery.

A Laser-Assisted Anastomotic Technique: Feasibility on Human Diseased Coronary Arteries

OBJECTIVE

Atherosclerotic disease might hamper the efficacy of the Excimer laser-assisted Trinity Clip anastomotic connector in coronary arteries. Therefore, its efficacy was evaluated on human diseased coronary arteries (study 1). In addition, the acute laser effects onto the coronary wall were assessed (study 2).

METHODS

Thirty-eight anastomoses were constructed on ex vivo human hearts. Atherosclerosis was histopathologically determined and subsequently related to the success of the technique (ie, connector positioning and laser punching; study 1). In addition, 20 anastomoses were constructed in an ex vivo (porcine, n = 8) and an in vivo [rabbit (n = 9) and porcine (n = 3)] model. Subsequently, the coronary was histologically studied on the presence of laser-induced damage (study 2).

RESULTS

In 13 of 38 anastomoses (study 1), the connector was malpositioned, 3 because of a severely diseased coronary wall and 10 because of an inner diameter less than the intended target range. The laser-punch success rates on coronary arteries with an early and advanced lesion were 100% (16/16) and 89% (8/9; lesions were located in the inferolateral wall), respectively. In one case, an advanced lesion (ie, fibrocalcified plaque) was located in the superolateral wall and caused a laser-punch failure. No histological signs of laser-induced damage were observed, in case of correct use (study 2).

CONCLUSIONS

This study demonstrates the feasibility of an anastomotic connector on human diseased coronary arteries and shows that lasering does not induce coronary wall damage. However, careful selection of the coronary, regarding the target inner diameter and disease status, will prevent construction failures. This connector could facilitate less invasive coronary artery bypass grafting.

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.

Evaluation of a novel laser-assisted coronary anastomotic connector - the Trinity Clip - in a porcine off-pump bypass model

To simplify and facilitate beating heart (i.e., off-pump), minimally invasive coronary artery bypass surgery, a new coronary anastomotic connector, the Trinity Clip, is developed based on the excimer laser-assisted nonocclusive anastomosis technique. The Trinity Clip connector enables simplified, sutureless, and nonocclusive connection of the graft to the coronary artery, and an excimer laser catheter laser-punches the opening of the anastomosis. Consequently, owing to the complete nonocclusive anastomosis construction, coronary conditioning (i.e., occluding or shunting) is not necessary, in contrast to the conventional anastomotic technique, hence simplifying the off-pump bypass procedure. Prior to clinical application in coronary artery bypass grafting, the safety and quality of this novel connector will be evaluated in a long-term experimental porcine off-pump coronary artery bypass (OPCAB) study. In this paper, we describe how to evaluate the coronary anastomosis in the porcine OPCAB model using various techniques to assess its quality. Representative results are summarized and visually demonstrated.

The nonocclusive laser-assisted coronary anastomotic connector in an off-pump porcine bypass model

OBJECTIVES

To facilitate minimally invasive coronary artery bypass grafting, a simplified alternative for hand-sutured anastomoses must be developed. We assessed the feasibility and anastomotic healing of the ameliorated Excimer laser-assisted nonocclusive anastomosis coronary prototype connector in an acute rabbit study (study 1) and in a long-term porcine off-pump coronary bypass study (study 2).

METHODS

Eighteen anastomoses were constructed on the abdominal aorta of the rabbit. In the porcine model, 15 left internal thoracic artery to left anterior descending coronary artery bypasses were evaluated intraoperatively and at 4 hours, 4 and 10 days, 2, 3, and 5 weeks, and 6 months (each n = 2 anastomoses). The anastomoses were examined by angiography, flow measurements, fractional flow reserve, coronary flow reserve, histologic features, and scanning electron microscopy.

RESULTS

In study 1, all 18 anastomoses were patent and resisted supraphysiologic pressures (n = 12, 300 mm Hg). In study 2, the connector enabled nonocclusive and fast (7.7 ± 2.2 minutes, mean ± standard deviation) anastomosis construction. All but 1 of 15 anastomoses (owing to a technical error) were fully patent (FitzGibbon grade A) at follow-up. Histologic examination and scanning electron microscopy demonstrated complete endothelialization of the anastomoses at 10 days. At 6 months, no flow-limiting but streamline-covering intimal hyperplasia was shown (fractional flow reserve, 0.93 ± 0.07 mean ± standard deviation).

CONCLUSIONS

The new nonocclusive coronary connector is easy to use, and the long-term results suggest favorable healing and remodeling in the porcine model. After downsizing, this anastomotic device, with its emphasis on zero ischemia and simplified prebounding of vessel walls, has intrinsic potential for minimally invasive off-pump coronary artery bypass surgery.

Distal anastomotic patency of the Cardica C-PORT(R) xA system versus the hand-sewn technique: a prospective randomized controlled study in patients undergoing coronary artery bypass grafting

OBJECTIVES

The C-Port® Distal Anastomosis Systems (Cardica, Inc., Redwood City, CA, USA) demonstrated favourable results in feasibility trials. However, distal vein anastomoses created with the C-Port® or C-Port xA® system have never been compared with hand-sewn distal vein anastomoses. The objective of this study was to compare distal end-to-side anastomoses facilitated with the C-Port xA® System with the traditional hand-sewn method.

METHODS

This single-centre prospective randomized controlled study comprised 71 patients (device group n = 35, control group n = 36) who underwent primary elective coronary artery bypass grafting between June 2008 and April 2011. The primary study end-point was 12-month distal anastomotic patency, which was assessed with prospective ECG-gated 256-multislice computed tomographic coronary angiography using a step-and-shoot scanning protocol. For the primary end-point, a per-protocol analysis was used.

RESULTS

In the device group, four (11%) anastomoses were converted to hand-sewn anastomoses, and additional stitches to achieve haemostasis were necessary in 22 (76%) patients. There was no hospital mortality in either group. During the 12-month follow-up, a single death occurred in the Device group and was unrelated to the device. Twenty-nine patients in the device group and 32 in the control group completed 12-month CT coronary angiography. The overall patency of 160 studied distal vein graft anastomoses was 93%. Comparison of the end-to-side target anastomosis showed 12-month patencies of 86 and 88% in the device group and the control group, respectively.

CONCLUSIONS

According to these preliminary results and despite the limited number of patients, the use of the C-Port xA® System is safe enough to perform distal end-to-side vein graft anastomosis, with respect to 12-month end-to-side distal venous anastomotic patency. Although there are some technical challenges with this device, the incidence of complications is comparable to the traditional hand-sewn technique.

A new nonocclusive laser-assisted coronary anastomotic connector in a rabbit model

OBJECTIVE

The Excimer laser-assisted nonocclusive anastomotic technique is a nonocclusive, facilitated bypass technique that is currently Conformité Européenne and Food and Drug Administration approved for clinical application in neurosurgery. In the present study, we assessed the safety and feasibility of a newly developed Excimer laser-assisted nonocclusive anastomosis-based prototype coronary anastomotic connector in an acute rabbit abdominal aortic bypass model before application in experimental coronary bypass surgery. In addition, 2 sealants were tested to facilitate anastomotic hemostasis in the current device prototype.

METHODS

A total of 40 anastomoses were constructed on the abdominal aorta (3.5 mm outer diameter) of 10 rabbits. The anastomotic circumference was sealed by a surgical sealant to obtain complete hemostasis (BioGlue vs TachoSil). The anastomoses were evaluated by flow measurements construction time, hemostasis, histologic analysis, and burst pressure testing.

RESULTS

The connector enabled a nonocclusive and fast (6.0 ± 1.7 minutes, mean ± SD [including sealing]) anastomosis construction and complete hemostasis in 95% (35/37). Sealing with BioGlue was faster than with TachoSil (19% vs 53% of construction time). Despite technical imperfections (7/40 failures to completely retrieve the flap by the laser), all 40 anastomoses were patent, showed reproducible construction with intima-adventitia apposition, streamlining thrombus coverage of the intraluminal laser rim, and no vessel wall damage. All anastomoses resisted ex vivo supraphysiologic pressures (> 300 mm Hg).

CONCLUSIONS

The results of the present study have demonstrated that the Excimer laser-assisted nonocclusive anastomotic connector is safe and reliable and can be efficiently applied in an acute rabbit abdominal aortic bypass model. Provided the limitations can be addressed, this easy-to-use and nonocclusive technique has the potential to facilitate minimally invasive coronary bypass surgery.

Initial clinical experience with a new end graft holder for anastomosis in coronary surgery

OBJECTIVE

We assessed the feasibility and effectiveness of a novel end graft holder for coronary artery bypass grafting (CABG) and evaluated anastomotic patency and early clinical results.

METHODS

The end graft holder was applied to 45 consecutive patients. Operative characteristics were off-pump CABG in 22.2%, emergency in 28.9%, and concomitant cardiac surgery in 13.3%.

RESULTS

The device was used safely without graft injury or inadequate gripping on grafts. Postoperative angiography showed that the patency rate of distal anastomosis was 96.7% (arterial, 100%; venous, 94%). All proximal aortic and composite graft anastomoses were patent without stenosis. The rate of 30-day major adverse cardiac and cerebrovascular events was 13.3% (operative deaths, 3; repeated CABG, 1; percutaneous coronary arterial intervention, 1; and cerebral infarction, 1). None of the elective patients died during hospitalization.

CONCLUSION

Our initial clinical experience demonstrated that the new end graft holder was safe, reliable, and effective during CABG. The excellent fixation and visualization of the graft with the device might be particularly beneficial for off-pump CABG or for teaching trainees.

Mid-term patency after magnetic coupling for distal bypass anastomosis in coronary surgery

BACKGROUND

The magnetic vascular positioner (MVP), a device for distal bypass anastomosis in coronary surgery, was developed to allow a simple and rapid procedure and to improve graft patency. We analyze our mid-term results with this device.

METHODS

Eighteen distal anastomoses were performed by using the MVP, and 18 with a hand-sewn technique were completed in 11 patients. The target arteries for the MVP anastomosis were the left anterior descending in 9 patients, a marginal branch in 4, a diagonal branch in 3, and right coronary artery in 2. The left internal thoracic artery was used as graft in 9 patients, saphenous vein in 6, right internal thoracic artery in 2, and radial artery in 1.

RESULTS

Coronary angiography was performed at discharge and after a complete follow-up of 19 +/- 3.5 months. Patency at follow-up was 83.3% (15/18) for MVP anastomoses and 100% (18/18) for hand-sewn anastomoses. All occluded MVP anastomoses were performed with small-size devices. In one patient, a high-grade left main stenosis was overestimated. Competitive flow may be suspected in this case as a cause of graft occlusion. No deaths occurred during hospital stay or during follow-up. Freedom from reintervention was 100%.

CONCLUSIONS

The MVP is the only mechanical connector for distal anastomoses applicable for all kind of grafts, for all coronary artery locations, and with both end-to-side and side-to-side technique. Mid-term patency of MVP anastomoses is acceptable but inferior to the patency of hand-sewn anastomoses. Occlusion of MVP supplied grafts may be produced by small device size.

S2 connector versus suture: distal coronary anastomosis remodeling, patency, and function in the pig

BACKGROUND

Anastomotic connectors could be the key to less invasive bypass surgery, including endoscopic procedures, but equivalence to conventional suturing needs to be established. A novel distal coronary connector was tested pre-clinically for safety and efficacy in comparison to conventional suturing.

METHODS AND RESULTS

Left internal thoracic to left anterior descending coronary artery bypasses were constructed off-pump in 35 pigs (73+/-8 kg). An intraluminal metal connector (S2AS) was used in 21 and conventional suturing in 14 animals. S2AS anastomosis construction was easier achieved in one-fourth of the conventional construction time (3.7+/-0.7 versus 16.5+/-2.6 minutes; P<0.001). Acute patency tended to be better (P=0.15). All anastomoses were evaluated intraoperatively, and subgroups at 90 and at 180 days. Patency was 100%. An effective remodeling response was observed in all groups, resulting in unobstructed anastomoses with excellent hemodynamic performance (fractional flow reserve > or = 0.93 at 180 days). At 6 months, the noncompliant connector was covered with stabilized neointima that was thinner than found on the suture line (0.10+/-0.04 versus 0.31+/-0.13 mm; P=0.01). The connector induced less lumen loss (-0.6+/-6.5 versus 21.6+/-19%; P=0.03). The initial side-to-side configuration had remodeled to an end-to-side shape as intended.

CONCLUSIONS

In the porcine model, the connector rapidly and consistently produced high-quality anastomoses that fully met current standards on patency and function. Unconventional aspects like a noncompliant intraluminal ring and a side-to-side to end-to-side converted configuration did not interfere with favorable anastomosis remodeling. These findings shed a new light on the anatomical prerequisites for anastomosis patency.

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.

Clampless arterial coronary artery bypass grafting with the use of magnetic coupling devices

BACKGROUND

The aim of our study was to evaluate the feasibility of using the Ventrica MVP device to perform proximal anastomoses as part of the clampless off-pump coronary artery bypass (OPCAB) arterial revascularization procedure.

METHODS

We present our preliminary experience of these first nine coronary artery cases performed in the UK from April 2003 to December 2004.

RESULTS

The device was used in eight patients for the proximal anastomosis of a radial artery (n = 8) or right internal thoracic artery (n = 1) graft as a Y-graft from the left internal thoracic artery to the circumflex territories. One patient died in this series although the autopsy showed that the device was intact and free of clots and the reported cause of death was an acute cardiac event due to myocardial ischemia. Anastomotic patency was confirmed in five patients with the use of multidetector row computed tomography coronary angiogram. The anastomosis time in our series was 6.3 +/- 2.1 minutes and the blood loss 814 +/- 245 mL. The mean length of stay was 5.2 +/- 1.2 days. No other significant major morbidity events were observed postoperatively (neurological complications, renal failure, and reopening for bleeding). The assessment of quality of life at 6 months postoperatively using SF-36 questionnaires revealed improvement.

CONCLUSION

The versatile use of Ventrica MVP distal anastomotic device is feasible in clinical practice allowing surgeons to perform proximal anastomoses and arterial OPCAB surgery with short learning curve and without compromising the clinical outcome and quality of life.

A New Needle Driver for Minientry Coronary Artery Bypass

PURPOSE

This article describes our clinical experience with a new needle driver (Olympus, Tokyo, Japan), which we have produced to facilitate minithoracotomy or port-access coronary artery anastomosis with the running suture technique.

METHODS

The needle driver is 21 cm long, weighs 38 g, and has a grip shaft 1.4 cm in diameter. The device is held like a pencil. A side lever and a revolving disk in the shaft are manipulated with the fingers; a fine needle with a 7-0/8-0 monofilament suture can be grasped/released and driven to penetrate the coronary arterial wall. This device was employed in 10 consecutive patients (8 men, 2 women, 73 +/- 7.5 years old), and off-pump bypass to the left anterior descending artery was achieved using the left internal thoracic artery or vein via a minithoracotomy (4.2 +/- 0.6 cm long).

RESULTS

There was no instrument-related injury during each anastomosis. The mean sewing time per anastomosis was 12 minutes (range, 8-18 minutes). Angiography confirmed the patency of the graft in all cases.

CONCLUSIONS

Although our experience is limited, we consider the present needle driver to be a viable device for facilitating off-pump, minientry coronary artery anastomosis with the suturing technique.