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Ann Thorac Surg 1999;68:1552-1554
© 1999 The Society of Thoracic Surgeons
a Sclifosovsky Scientific Emergency Center, Moscow, Russia
Address reprint requests to Dr Travine, Moskva, D. Bednogo, 17-3-222 123423 Russia
e-mail: dndkosty{at}cityline.ru
Presented at Evolving Techniques and Technologies in Minimally Invasive Cardiac Surgery, San Antonio, TX, Jan 22–23, 1999.
Abstract
Background. The purpose of this study was to examine the feasibility of performing totally endoscopic myocardial revascularization through the abdominal cavity.
Methods and Results. The right gastroepiploic artery was harvested endoscopically through three troacars in 46 human cadavers. Then, a 5-cm hole was made in the diaphragm to expose the right coronary artery. With the help of two vacuum pods, we fixed a site of the right coronary artery and made a right gastroepiploic artery-right coronary artery anastomosis. In 20 cases, continuous Prolene suture was used, and in 26 experiments, we applied a sutureless technique. Twenty-three anastomosis were patent.
Conclusions. Despite the low patency rate, the transabdominal approach of totally endoscopic bypass grafting is promising and demands further investigation.
The minimally invasive surgical concept has gained acceptance in all cardiac surgery subspecialties, despite the fact that the first presentations regarding minimally invasive direct coronary artery bypass (MIDCAB) were made just 4 years ago, excellent results have been obtained with MIDCAB all over the world. This field has been developed in several directions: the most commonly performed minimally invasive procedure is bypass grafting of the left anterior descending artery (LAD) with the use of the left internal mammary artery (LIMA) through a limited thoracotomy [1]. Also performed are MIDCAB with thoracoscopic support [2, 3], and port-access coronary surgery performed on the basis of femorofemoral cardiopulmonary bypass (CPB).
In the literature, there are just a few articles devoted to the first experimental [4] or clinical [5] experience of totally thoracoscopic coronary bypass grafting with the use of the Heartport system (Heartport Inc, Redwood, CA) for CPB. Besides its obvious advantages, this approach requires CPB, which may limit the indications for this procedure, particularly in higher risk patients. Meanwhile, experimental studies of fully thoracoscopic coronary artery bypass grafting on the beating heart have been continued, which, in our opinion, corresponds to the MIDCAB concept completely [3, 6].
For the most part, the MIDCAB procedure is limited by single-vessel disease, usually that of the left anterior descending artery (LAD), although some experience with bypass of the diagonal, intermediate branches of the left coronary artery and the right coronary artery (RCA) exist. In the case of the RCA lesion, one of the conduits of choice for MIDCAB surgery is the right gastroepiploic artery (RGEA) [1, 3], however, harvesting of this conduit by the traditional technique may be accompanied by certain complications: intestinal paralysis, adhesion process, and hernias. An endoscopic approach of RGEA harvesting leads to solving these problems.
Material and methods
Since 1997, our team of cardiac surgeons has carried out more than 200 experiments on the application of the endoscopic technique in MIDCAB surgery. Cadaver experiments were performed in order to develop thoracoscopic and laparoscopic approaches for harvesting of the IMAs and the RGEA, to gain manual practice, working with endoscopic instruments and performing coronary anastomosis through limited access on the beating heart. We have subsequently developed a technique for RGEA endoscopic mobilization and taking it into the pericardium, as well as a surgical method for fully endoscopic RCA bypass grafting with the use of the RGEA.
Human cadavers were used to determine a surgical method for laparoscopic dissection of the RGEA. We used a 30° endoscope without magnification and endoscopic instruments, which are usually used for laparoscopic surgery.
Air insufflation into the abdominal cavity was performed through the Veress needle, and then three 10-mm ports were inserted, via the annulus umbilicalis (Fig 1).
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In clinical practice, we started by performing the anastomosis between the LAD and the thoracoscopically harvested LIMA through the limited anterior 4- to 5-cm thoracotomy. Then, we began to use the endoscopic technique in patients with two-vessel lesions. In cases of LAD and RCA lesions, we used the endoscopic harvesting of the LIMA and the RGEA and one or two limited incisions (the left anterior thoracotomy and/or the lower ministernotomy). The employment of the endoscopic technique for the RGEA harvesting, in our opinion, has some obvious advantages: less traumatic than laparotomy or minilaparotomy; elimination of any concern regarding kinking; easy control of feasible intraoperative bleeding; and prevention of hernias and the adhesion process.
Anatomical proximity of the pericardium and the diaphragm gave us the idea of using the transdiaphragmal approach for endoscopic anastomosis of the RGEA to the RCA, and our experimental and clinical experience allowed us to start developing a totally endoscopic technique of RCA bypass grafting. Our current experimental studies are devoted to this problem. All experiments were carried on in the operating room, where V. P. Demikhov used to operate in, which was a matter of great inspiration.
Methods
Forty-six cadavers were used in the current studies. They were divided in two groups: (1) n = 20; (2) n = 26. In the first group, the experiments started with harvesting of the RGEA through three 10-mm ports as described above. The incision of 5 cm in the corpus tendineum of the diaphragm and the pericardium was made to expose the RCA. Three additional 10-mm ports were inserted into the abdominal cavity in the right mesogastrium.
Particular positions
(Fig 2). An endoscopic atraumatic temporary occlusion clamp was applied to the RGEA and then the conduit was positioned in the pericardium (Fig 2). The utmost right and the utmost left ports in the epigastrium were used for vacuum pods in order to stabilize the target site of the RCA, and they also retracted the diaphragm, improving the exposure of the RCA. A 5- to 7-mm arteriotomy was made, and the RGEA was anastomosed with the RCA with a running continuous suture (Prolene 7/0, 18 cm long). The surgeon controlled the endoscopic instruments (microvascular anastomosis suture needle holder and microvascular forceps), and the assistant guided the endoscope and microvascular forceps. A U stitch was placed in the heel of the RGEA, with both needles passing from out to in, to facilitate the anastomosis. The needles were then both passed from within the heel of the RCA out, before one arm was sewn up, each side toward the toe. On completion of the anastomosis, an instrumental tie was performed. The temporary occlusion clamps on the RCA applied near the anastomotic site were released. The time of the complete anastomosis was 25 to 40 minutes.
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Results
The endoscopic technique of RGEA harvesting allowed the dissection of the whole length from the pylorus to the splenic arteries breves. The average length of conduit was 27 ± 2.5 cm. The length of the artery in the pericardium (8 to 14 cm) was enough to perform anastomosis with the RCA in retrograde or anterograde directions and even with any other coronary artery. The mean time of the harvesting was 45 ± 25 minutes. Even in the first experiments, it did not take more than 70 minutes to harvest the whole length of the RGEA. Neither RGEA nor stomach damage occurred.
On completion of each experiment, we checked the patency of the anastomoses. In the first group, 15 of 20 anastomoses were patent and were free of narrowing. In the second group, only eight anastomoses were normal and patent; nine were patent but narrowed. The main problem we faced while inserting the RGEA with the frame construction on into the RCA was the deformation of the anastomosis due to some shortcomings of the construction. Thus, 23 anastomoses (50%) were successful (15 sutured and 8 mechanical).
Comment
At the present stage, the method is not well worked out yet. At the very beginning, we had to solve the problem of the length of the endoscopic instruments. In order to manipulate in the pericardium through the transabdominal approach, we had to lengthen the instruments up to 45 cm. Quite a few problems are yet to be solved. One of them is closing the incision in the diaphragm. It is obligatory but not a simple procedure, and we have not developed it yet. During the experiment, six to eight ports are to be inserted, which causes more intensive insufflation, which in turn may cause cooling of the patient. In our opinion, use of the alternative to air insufflation (laparolifter) is not convenient because of changing geometry of the abdominal cavity.
The main unsolved problem still is oxygen supply of the myocardium during the cross-clamping of the RCA. According to our clinical practice, the RCA is the most sensitive and unpredictable coronary artery in regards to its tolerance of ischemia. So, one of the possible ways to solve the problem is to shorten the time spent clamping the RCA and performing the operation. Quite a few alternatives to an endoscopically sutured anastomosis have been examined, including laser tissue welding, tissue gluing, and vascular staplers; however, a sutured anastomosis remains the most applicable [6]. However, appearance of the new coronary anastomosis staplers for endoscopic coronary surgery, similar to those anastomosis staplers for conventional coronary surgery, which already exist, may help in the progress of endoscopic myocardial revascularization.
Our experimental studies demonstrate that the performance of totally endoscopic coronary bypass grafting through the abdominal cavity is principally possible.
Our efforts are devoted toward extending MIDCAB surgery and making it even less invasive. According to our experience, the most limiting factors for fully endoscopic coronary surgery are the lack of the surgeon’s experience in performing an exact arterial conduit—coronary artery anastomosis with endoscopic instruments on the beating heart—and the lack of the specially made endoscopic instruments. We hope that as surgeons gain more experience and enabling technologies simplify the technique, the procedure can be extended.
Despite comparatively low patency rate, the transabdominal approach of totally endoscopic bypass grafting is promising and may be a great contribution to promoting the strategy of the fully endoscopic coronary surgery on the beating heart.
References
This article has been cited by other articles:
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  A. W. Susilo and A. P. Schulz Totally Robotic Technique in Multivessel Coronary Disease -- Is it Possible? Asian Cardiovascular and Thoracic Annals, March 1, 2002; 10(1): 92 - 94. [Abstract] [Full Text] [PDF]
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 C. Byhahn, S. Mierdl, D. Meininger, G. Wimmer-Greinecker, G. Matheis, and K. Westphal Hemodynamics and gas exchange during carbon dioxide insufflation for totally endoscopic coronary artery bypass grafting Ann. Thorac. Surg., May 1, 2001; 71(5): 1496 - 1501. [Abstract] [Full Text] [PDF]
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