Early experience of coronary artery bypass grafting with a new self-closing clip device

OBJECTIVE: We are in the midst of development of several new anastomotic devices for use in coronary artery bypass grafting surgery. This study was designed to examine one of these devices (a new self-closing clip) for left internal thoracic artery-left anterior descending coronary artery anastomosis. Its feasibility and the quality of anastomosis were evaluated. METHODS: Fourteen patients who underwent first-time elective coronary artery bypass surgery were enrolled between July and December 2000. The left internal thoracic artery was anastomosed to the left anterior descending coronary artery in an interrupted manner with Coalescent U-clips (Coalescent Surgical, Inc, Sunnyvale, Calif). Immediate patency was checked with a transit-time flowmeter. Selective angiography was performed 6 months after surgical intervention. RESULTS: Five patients underwent on-pump coronary bypass grafting, 9 on the beating heart. One patient was excluded from the study intraoperatively because of a poor target site necessitating a 2-cm-long anastomosis. Left internal thoracic artery-left anterior descending artery anastomoses were created with an average of 11.8 clips in 15.9 minutes. Mean graft flow was 45.6 mL/min. Neither conversion to standard suture technique nor revision of anastomosis was necessary. There tended to be a learning curve in the anastomosis on the beating heart. Postoperative lengths of stay in the intensive care unit and the hospital were 20.7 hours and 3.9 days, respectively. Neither death nor major complication was seen, except for temporary atrial fibrillation in 2 patients. Graft patency at 6 months was 100% (FitzGibbon grade A). CONCLUSION: Left internal thoracic artery-left anterior descending artery anastomoses can be created safely and effectively with new self-closing clips on the beating, as well as the arrested, heart. Midterm patency was shown to be perfect by means of angiography.     

Facilitated coronary anastomosis using a nitinol U-Clip device: bovine model

OBJECTIVE: The coronary anastomosis is the most difficult part of the coronary bypass procedure, particularly when using a minimally invasive technique. Methods to facilitate coronary anastomosis will make the minimally invasive approach to coronary bypass feasible. We sought preclinical validation and testing of the design and efficacy of a self-closing penetrating clip that can be used to facilitate the creation of graft-to-coronary end-to-side anastomosis. METHODS: The nitinol U-Clip device (Coalescent Surgical, Inc, Sunnyvale, Calif) was used in 13 consecutive calves (63-118 kg). In each animal, the device was (1) used to create an anastomosis of the right internal thoracic artery to a coronary artery with the heart beating and (2) compared to polypropylene suture when used to repair two carotid arteriotomies. Intraoperative, 1-week, 8-week, and 26-week postoperative angiograms and detailed histopathologic examinations were used to evaluate anastomotic patency and healing characteristics. RESULTS: The nitinol U-Clip device successfully created right internal thoracic artery-coronary artery anastomoses and repaired carotid arteriotomy sites in 13 consecutive calves. The clip was precisely placed by means of the integrated suture and needle in a fashion similar to that used for conventional suture. The clip met design specifications by reliable release and automatic closure, thereby eliminating knot tying and assisted suture management. At the time of harvest, angiography showed widely patent coronary anastomoses (FitzGibbon grade A criteria, n = 13) and carotid arteriotomy repair sites (n = 13). Histopathologic evaluation confirmed normal healing with smooth circumferential neointimal resurfacing at the anastomotic and repair sites. CONCLUSIONS: The nitinol U-Clip design and function was validated in the formation of bovine coronary anastomoses on the beating bovine heart with excellent graft patency and healing characteristics. The nitinol U-Clip device tests favorably when compared with conventional sutures in carotid artery repair.     

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.     

Noninvasive evaluation of internal thoracic artery and left anterior descending coronary artery anastomotic sites using transthoracic Doppler echocardiography: comparison with coronary arteriography

OBJECTIVES: This study was designed to evaluate anastomotic sites located between the internal thoracic artery and left anterior descending coronary artery using transthoracic Doppler echocardiography, and then to clarify the accuracy of those results by comparison with coronary arteriographic findings. METHODS: We examined 35 consecutive patients who had undergone bypass surgery. The echocardiographic examinations were performed within approximately 1 week of follow-up coronary arteriography, which occurred at 4.3 +/- 2.2 months after bypass surgery. We measured the diameter using intraluminal flow signals, and we also measured flow velocity. RESULTS: Adequate spectral Doppler recordings of coronary flow in the anastomosis were obtained in 31 (89%) of the 35 study patients. In the normal anastomosis group (n = 25), the diameter and the peak blood flow velocity of the internal thoracic artery and left anterior descending coronary artery were 1.5 +/- 0.3 mm and 2.0 +/- 0.4 mm, and 58 +/- 25 cm/s and 47 +/- 20 cm/s, respectively. Stringed internal thoracic artery was found in 4 patients; the echocardiographic findings revealed a greater amount of information regarding the physiologic state in the area of anastomosis compared with angiographic findings. In a stenotic anastomosis found in 2 patients, the blood flow velocity findings at the anastomotic sites (83 +/- 228 cm/s) were higher than those in normal anastomotic patients (59 +/- 28 cm/s). CONCLUSIONS: Transthoracic Doppler echocardiography enabled an effective evaluation of anastomotic sites between the internal thoracic artery and left anterior descending coronary artery in over 80% of our patients. This totally noninvasive method is thought to be reliable and able to provide a greater amount of information, compared with coronary arteriography, regarding the physiologic state of an anastomosis, such as a competitive relationship.     

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.     

Experimental off-pump coronary bypass using a robotic telemanipulation system.

We hypothesized that a high-quality anastomosis between the left internal thoracic artery and the left anterior descending coronary artery could be constructed off-pump using a 4-degrees-of-freedom robotic telemanipulation system, endoscopic myocardial stabilization, and two-dimensional visualization. Nine swine were used. Three ports were created on the left chest for the endoscope and the two robotic arms, and another port was created on the right chest for the endostabilizer. Quality of anastomosis was assessed by angiography, analysis of flow, survival after proximal coronary ligation, and histopathology. All nine anastomoses were completed successfully in 22 +/- 3.6 minutes without the need for repair stitches. Left internal thoracic artery flow was 21.6 +/- 2.5 ml/min with diastolic dominant pattern. Eight animals (89%) survived for 60 minutes with the proximal left anterior descending coronary ligated. Angiographic patency was 100% with Fitzgibbon grade A in all. Histopathology of the anastomosis demonstrated minor changes in the integrity of the endothelium and the internal elastic lamina and absence of medial necrosis. We have demonstrated in our robotic off-pump coronary bypass model that a high-quality anastomosis can be constructed between the left internal thoracic artery and the left anterior descending coronary artery. These results support continued research towards robotic endoscopic off-pump CABG.     

Comparative analysis of the patency of the internal thoracic artery in the CABG of left anterior descending artery: 6-month postoperative coronary CT angiography evaluation

Objective

To assess the patency of the pedicled right internal thoracic artery with an anteroaortic course and compare it to the patency of the left internal thoracic artery , in anastomosis to the left anterior descending artery in coronary artery bypass grafting by using coronary CT angiography at 6 months postoperatively.

Methods

Between December 2008 and December 2011, 100 patients were selected to undergo a prospective coronary artery bypass grafting procedure without cardiopulmonary bypass. The patients were randomly divided by a computer-generated list into Group-1 (G-1) and Group-2 (G-2), comprising 50 patients each, the technique used was known at the beginning of the surgery. In G-1, coronary artery bypass grafting was performed using the left internal thoracic artery for the left anterior descending and the free right internal thoracic artery for the circumflex, and in G-2, coronary artery bypass grafting was performed using the right internal thoracic artery pedicled to the left anterior descending and the left internal thoracic artery pedicled to the circumflex territory.

Results

The groups were similar with regard to the preoperative clinical data. A male predominance of 75.6% and 88% was observed in G-1 and G-2, respectively. Five patients migrated from G-1 to G-2 because of atheromatous disease in the ascending aorta. The average number of distal anastomoses was 3.48 (SD=0.72) in G-1 and 3.20 (SD=0.76) in G-2. Coronary CT angiography in 96 re-evaluated patients showed that all ITAs, right or left, used in situ for the left anterior descending were patent. There were no deaths in either group.

Conclusion

Coronary artery bypass grafting surgery involving anastomosis of the anteroaortic right internal thoracic artery to the left anterior descending artery has an outcome similar to that obtained using the left internal thoracic artery for the same coronary site.     

Reduction in brain embolization using the Aegis aortic cannula during bypass in swine

BACKGROUND: Although robotically assisted coronary arterial anastomoses are being performed clinically, the short-term and long-term quality and integrity of the left internal thoracic artery (LITA) to left anterior descending artery (LAD) anastomosis remains unknown. The goal of this study was to perform a histologic and angiographic assessment of porcine beating heart LITA to LAD anastomoses using either robotic assistance or a conventional freehand technique. METHODS: Twelve pigs underwent beating heart LITA to LAD anastomoses using either the robotically assisted (n = 6) or conventional freehand techniques (n = 6). Quantitative histologic analysis was performed in all animals in order to determine the degree of vascular wall damage. Selective coronary arteriography was performed in all animals immediately after the procedure in order to evaluate anastomotic patency. The unpaired Student's t test was used for all comparisons between groups. RESULTS: There were no differences in vascular wall damage between the robotically assisted and freehand techniques. Postoperative angiography revealed no stenoses in either group. CONCLUSIONS: Use of the robotically assisted technique for creation of a LITA to LAD anastomosis was not associated with increased histologic damage when compared with the freehand technique in a beating heart porcine model. Furthermore, there was no difference between the two techniques in postoperative patency rate. These results support further clinical investigation of robotically assisted coronary bypass surgery.     

Briefly occlusive coronary anastomosis with tissue adhesive

OBJECTIVE: We assessed the feasibility of a facilitated, briefly occlusive, sutureless coronary anastomosis technique in which side-to-side preglued (octylcyanoacrylate adhesive) bounded walls were opened by a conventional arteriotomy. METHODS: In low-flow (prothrombotic milieu, 相似文献   

Robot-assisted 13 MHz epicardial ultrasound for endoscopic quality assessment of coronary anastomoses

In totally endoscopic coronary artery bypass surgery, intra-operative assessment of anastomotic quality is needed. We evaluated the endoscopic application of epicardial ultrasound to visualize the coronary anastomosis and detect a construction error. In 8 pigs (71-78kg), 16 internal mammary artery to left anterior descending coronary artery anastomoses were constructed conventionally, either correctly (n=8) or incorrectly with a suture cross-over construction error (n=8). A 13MHz mini-transducer (15x9x6mm) was introduced through a port and manipulated by the 'da Vinci' system. The chest was re-opened and scanning repeated manually. Postoperatively, macroscopic inspection served as reference and the intra-operative ultrasound images were scored as 'correct' or 'construction error' by two blinded observers. All anastomoses were scored accurately by both observers. One anastomosis constructed to be correct was scored as construction error, due to narrowing of the outflow corner and anastomotic orifice. Ultrasound images corresponded with macroscopic inspection. Closed-chest scan time was about 1.5 times longer than open-chest scan time, 176s (88-464) (median, range) versus 125s (75-314) (P=0.01), respectively. Closed-chest epicardial 13MHz ultrasound scanning required a median of 3min and enabled discrimination between correctly and incorrectly constructed coronary anastomoses.     

Beating-heart totally endoscopic coronary artery bypass grafting: Report of a case

This case report presents beating-heart totally endoscopic coronary artery bypass grafting (TECAB) for single-vessel coronary artery disease. A 72-year-old man with isolated left anterior descending (LAD) coronary artery disease was considered eligible for TECAB. Left internal thoracic artery (LITA) mobilization and subsequent off-pump revascularization applying the LITA to the LAD in a closed chest environment was performed using the da Vinci surgical system (Intuitive Surgical, Mountain View, CA, USA). The LITA was first harvested completely in a totally skeletonized fashion through three incisions 1–2 cm long in the left thoracic wall. The LAD was immobilized with the aid of a heart stabilizer. The LITA was then anastomosed to the LAD with 10 interrupted sutures of a Nitinol self-closing S15 U-clip device (Medtronic, Minneapolis, MN, USA) on the beating heart without the use of cardiopulmonary bypass. The time acquired to perform anastomosis was 20 min, and the total operative time was 5 h 34 min. The postoperative course was uneventful and the patient was discharged 5 days after the operation. Beating-heart TECAB was successfully performed for this patient with single-vessel LAD disease. This approach may be an evolutionary step toward beating-heart multivessel TECAB.     

Occlusion versus shunting during MIDCAB: effects on left ventricular function and quality of anastomosis

BACKGROUND: Minimally invasive direct coronary artery bypass is an established clinical procedure for revascularization of the left anterior descending coronary artery. Mechanical stabilization and temporary occlusion is currently used to perform the anastomosis of the internal thoracic artery to the left anterior descending coronary artery. However, critical reduction of cardiac function can occur as a result of temporary ischemia. The purpose of this study was to evaluate whether ischemic sequelae can be avoided by using temporary intraluminal shunts and whether this alters early outcome. METHODS: Thirty-five patients underwent minimally invasive direct coronary artery bypass revascularization using a mechanical stabilizer. In group A (n = 20), the anastomotic site was temporarily occluded by tourniquets. In group B (n = 15), temporary intraluminal shunts were inserted into the anastomotic site without any occlusion of the left anterior descending coronary artery. Anastomosis of the internal thoracic artery to the left anterior descending coronary artery was performed in an identical fashion. A Swan-Ganz catheter was inserted, and transesophageal echocardiographic measurements were obtained for analysis of left ventricular (LV) function. Regional wall motion, cardiac index, stroke volume index, systolic and diastolic LV diameters, and fractional area change were measured during four periods: at the start of the operation (baseline), placement of the stabilizer (stabilization), left anterior descending coronary artery occlusion (occlusion) or insertion of temporary intraluminal shunts (shunt), and 30 minutes after reperfusion (reperfusion). Angiograms were obtained 4 to 6 days postoperatively. RESULTS: In group A, LV performance, cardiac index, stroke volume index, and fractional area change decreased during occlusion whereas systolic diameters increased. Almost two myocardial segments per patient developed severe hypokinesia in the perfusion area. These changes disappeared after 30 minutes of reperfusion, with increased LV function. In group B, LV function remained stable whereas hypokinetic wall motion was only detected in 2 patients. Early angiograms revealed 90% of the grafts were patent in group A versus 100% in group B. The need for percutaneous intervention during the first 6 months was 20% in group A versus 6.7% in group B. CONCLUSIONS: The use of temporary intraluminal shunts resulted in reduced acute ischemia and revealed wall motion abnormalities and maintained LV function. Furthermore, this technique suggests an improvement of early graft patency and a lower reintervention rate within the first 6 postoperative months. Thus, use of temporary intraluminal shunts appears to be superior to the occlusion technique early after minimally invasive direct coronary artery bypass procedures.     

Off-pump coronary artery bypass via left thoracotomy in patient with infective pancreatic fistula after surgery for bile duct carcinoma; report of a case

A 62-year-old man with infective pancreatic fistula after surgery for bile duct carcinoma underwent off-pump coronary artery bypass (OPCAB) through left thoracotomy to avoid the use of cardiopulmonary bypass and the postoperative mediastinitis, since this patient has infective pancreatic fistula close to the xiphoid process. The coronary arterial revascularizations were performed: left internal thoracic artery to left anterior descending branch and saphenous vein graft to descending thoracic aorta. The aortic mechanical anastomosis device, aortic connector, was utilized the proximal anastomosis of saphenous vein graft so as to avoid aortic clamp, while the distal anastomoses were completed with stabilizer and apical retraction device. Postoperative angiogram showed both grafts were patent. No signs of infection or recurrence of malignant neoplasm was observed. OPCAB via left thoracotomy is one of useful options for patients in whom median sternotomy is not suitable approach for myocardial revascularizations.     

Reoperative off-pump coronary revascularization via left thoracotomy using the PAS-Port system to the descending thoracic aorta: report of a case

We performed redo-off-pump coronary artery bypass grafting( OPCAB) via a left thoracotomy using the PAS-Port system for proximal vein graft anastomoses in a patient with posterolateral myocardial ischemia. The patient was a 76-year-old man who had undergone coronary artery bypass grafting (CABG)[ left internal thoracic artery( LITA)-left anterior descending artery( LAD), saphenous vein graft(SVG)-posterior descending artery( 4PD), and SVG-postero-lateral branch( PL)] 14 years previously. Coronary angiogram showed that the LITA-LAD graft was patent but that the SVG-PL, left main trunk( LMT) and proximal right coronary artery(RCA) were occluded, and that there were 90% stenoses of LAD #7 and SVG-4PD anastomotic site. With catheter intervention therapy, stenosis of the SVG-#4PD was dilated. We then performed revascularization from the descending aorta to the second diagonal (D2) and PL with a saphenous vein graft via left thoracotomy using off-pump technique. To avoid descending aortic clamping, we used the PAS-Port system for proximal anastomosis. The postoperative course was uneventful and the patient was discharged on postoperative day 28. A redo-CABG is thought to be with high risk. Our procedure, however is safe and useful and can be an option for redo-CABG in the posterolateral area.     

Failure of internal thoracic artery grafts: conclusions from coronary angiography mid-term follow-up

BACKGROUND: The objective of this study was to identify causes of the failures of internal thoracic artery bypass grafts according to operative technique, the internal thoracic artery used, and the coronary artery grafted. METHODS: This retrospective study concerns 302 follow-up angiographies performed in patients treated with 512 internal thoracic artery bypass grafts: 115 single grafts, 78 sequential grafts, and 109 grafts with two internal thoracic arteries (61 Y grafts). Postoperative angiography was performed after a mean period of 17.3 +/- 4.1 months. RESULTS: Failures consisted of 11 (2%) occluded grafts and 19 (4%) nonfunctioning grafts (threadlike internal thoracic artery). There was no difference in patency among the various types of left anterior descending artery bypass grafts anastomosed with the left internal thoracic artery. The failure rate was higher with the right internal thoracic artery (13%) than with the left internal thoracic artery (4%; p < 0.05). The failure rate of the left anterior descending artery bypass grafts (3%) was lower than that for the branches of circumflex artery bypass grafts (13%; p < 0.05). The 19 cases of nonfunctioning grafts did not include significant anastomotic stenosis: 14 were related to competitive blood flow, 4 to a poor recipient coronary arterial bed, and 1 to significant distal coronary stenosis. CONCLUSIONS: At least two thirds of failures of bypass grafts could have been avoided by more objective analysis of the coronary stenosis on preoperative coronary angiography and better mastery of the surgical technique.     

Sutureless coronary anastomosis with an anastomotic device and tissue adhesive in off-pump porcine coronary bypass grafting

OBJECTIVE: In the search for a facilitated coronary artery anastomosis, we assessed the feasibility of a hybrid anastomosis technique that used a prototype anastomotic device with an extraluminal frame (crinoline-like) and octyl-cyanoacrylate adhesive. METHODS: During off-pump coronary artery bypass grafting in pigs (n = 8), a left internal thoracic artery-right coronary artery anastomosis was constructed and evaluated during the operation and at 5 postoperative weeks. The anastomosis was examined by flow measurement, angiography, intraluminal cast geometric analysis, and histologic analysis. RESULTS: Anastomosis construction required 6.2 +/- 1.3 minutes (mean +/- SD). At 5 weeks all anastomoses were fully patent, with minor anastomotic diameter narrowing (median 16%, 15th-85th percentile 16%-26%). After 30-second graft occlusion, median peak hyperemic flow response was 5.0 (15th-85th percentile 4.4-6.5). As a result of complete, streamlining filling of anastomotic wall recesses by neointima formation, more intimal hyperplasia was found in the crinoline-adhesive anastomoses than in sutured control anastomoses. No excessive, lumen-narrowing neointima formation was observed, however. CONCLUSIONS: The hybrid coronary anastomosis technique was feasible without any need for dedicated application tools. If technical improvements can be realized, the hybrid technique may provide an alternative to manual suturing.     

Benefits accruing to grafting of the right internal thoracic artery to the left anterior descending artery in coronary artery bypass grafting.

OBJECTIVES: We have investigated the effects and outcome from grafting the right internal thoracic artery to the left anterior descending artery in coronary artery bypass grafting. METHODS: We analyzed the findings in 185 patients who underwent coronary artery bypass grafting involving right internal thoracic artery-left anterior descending artery bypass. The survival rate, cardiac events related to the right internal thoracic artery-left anterior descending artery graft, and graft patency were investigated. In cardiac catheterization, the production of nitric oxide from the endothelium of the internal thoracic artery was measured as the plasma nitrite and nitrate levels by the Griess reaction. The reactions to acetylcholine infusion (5 micrograms) in the right internal thoracic artery (n = 4) were compared to those in the left internal thoracic artery (n = 9) grafts. RESULTS: The hospital mortality rate was 0.5%. The actuarial survival rate at 11 years after operation was 98.81%. The rate of freedom from cardiac events at 11 years after operation was 92.08%. The rate of patency of the right internal thoracic artery-left anterior descending artery was 97.0% in 133 patients. Nitric oxide production was calculated as (total nitrite plus nitrate production in response to stimulation by acetylcholine-total nitrite plus nitrate level before acetylcholine load)/(total nitrite plus nitrate level before acetylcholine load). There was no significant difference in changes in plasma concentration in response to acetylcholine stimulation between the right internal thoracic artery-left anterior descending artery and left internal thoracic artery-left anterior descending artery groups (20 +/- 29% versus 5 +/- 10%). CONCLUSIONS: The right internal thoracic artery-left anterior descending artery grafts exhibited good patency and release of nitric oxide in response to acetylcholine loading, similar to left internal thoracic artery-left anterior descending artery grafts.     

Initial United States clinical trial of robotically assisted endoscopic coronary artery bypass grafting

OBJECTIVES: With traditional instruments, endoscopic coronary artery bypass grafting has not been possible. This study was designed to determine the clinical feasibility of using a robotically assisted microsurgical system to create endoscopic coronary anastomoses. Methods And Results: Ten patients underwent endoscopic coronary artery bypass grafting of the left internal thoracic artery to the left anterior descending artery. Subxiphoid endoscopic ports (2 for instruments, 1 for a camera) were placed, and a robotic system was used to perform the left internal thoracic artery-left anterior descending artery bypass graft. Conventional techniques were used to perform the other grafts. Blood flow through the left internal thoracic artery graft was measured in the operating room and was adequate in 8 of 10 patients. The 2 inadequate grafts were revised successfully by hand. Six weeks after the operation, selective coronary angiography demonstrated a graft patency of 100% (8/8). There were no technical failures of the robotic system. The only postoperative complication was mediastinal hemorrhage in 1 patient. CONCLUSIONS: This pilot study demonstrates the feasibility of robotically assisted endoscopic coronary artery bypass grafting.     

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.     

Benefits accruing to grafting of the right internal thoracic artery to the left anterior descending artery in coronary artery bypass grafting

Objectives: We have investigated the effects and outcome from grafting the right internal thoracic artery to the left anterior descending artery in coronary artery bypass grafting.Methods: We analyzed the findings in 185 patients who underwent coronary artery bypass grafting involving right internal thoracic artery-left anterior descending artery bypass. The survival rate, cardiac events related to the right internal thoracic artery-left anterior descending artery graft, and graft patency were investigated. In cardiac catheterization, the production of nitric oxide from the endothelium of the internal thoracic artery was measured as the plasma nitrite and nitrate levels by the Griess reaction. The reactions to acetylcholine infusion (5 μg) in the right internal thoracic artery (n = 4) were compared to those in the left internal thoracic artery (n = 9) grafts.Results: The hospital mortality rate was 0.5%. The actuarial survival rate at 11 years after operation was 98.81%. The rate of freedom from cardiac events at 11 years after operation was 92.08%. The rate of patency of the right internal thoracic artery-left anterior descending artery was 97.0% in 133 patients. Nitric oxide production was calculated as (total nitrite plus nitrate production in response to stimulation by acetylcholine-total nitrite plus nitrate level before acetylcholine load) / (total nitrite plus nitrate level before acetylcholine load). There was no significant difference in changes in plasma concentration in response to acetylcholine stimulation between the right internal thoracic artery-left anterior descending artery and left internal thoracic artery-left anterior descending artery groups (20 ± 29% versus 5 ± 10%).Conclusions: The right internal thoracic artery-left anterior descending artery grafts exhibited good patency and release of nitric oxide in response to acetylcholine loading, similar to left internal thoracic artery-left anterior descending artery grafts.