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(Circulation. 1995;92:45-49.)
© 1995 American Heart Association, Inc.

Articles

Right Gastroepiploic-to-Coronary Artery Bypass

The First Decade of Use

John Pym, MB, BS, FRACS, FRCSC; Peter Brown, MD, FRCSC; Mary Pearson, MD, CCFP; John Parker, MD, FRCPC

From the Department of Surgery (J. Pym, P.B., M.P.) and the Department of Medicine (J. Parker), Queen's University, Ontario, Canada.

Correspondence to Dr John Pym, Richardson House, 102 Stuart St, Kingston, Ontario, Canada K7L 2V6.

	Abstract

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Background The right gastroepiploic artery was first used by us as a coronary artery bypass graft (CABG) in June 1984 and has become an accepted alternative conduit for myocardial revascularization.

Methods and Results We have now performed this operation in 126 patients (111 of whom were men) aged 32 to 78 years. The right gastroepiploic artery was used as a pedicle graft to the right main coronary artery in 25 patients, to its posterior descending branch in 90, to a left ventricular branch in 2, to branches of the circumflex system in 6, and to the left anterior descending artery in 1. Free (aortocoronary) gastroepiploic grafts were placed to circumflex branches in 2 patients. There were 2 hospital deaths (stroke, arrhythmia), and mean±SD postoperative stay was 7.5±2.0 days. All survivors were symptomatically improved and are functionally in New York Heart Association functional class I or II. There have been 3 late deaths (at 34, 50, and 84 months) in 2 to 120 months of follow-up (mean, 41.4 months). Angiography of bypass grafts and coronary arteries was performed in 44 patients at 7 days to 80 months postoperatively, providing direct evidence of gastroepiploic graft patency in 34 patients and strong indirect evidence in another 6; adequate data could not be obtained in 3 patients for technical reasons, and 1 graft was occluded.

Conclusions These short-term, intermediate, and long-term results demonstrate the suitability of the right gastroepiploic artery as a CABG. The use of the right gastroepiploic artery as a graft to coronary arteries on the posterior wall of the heart, in conjunction with one or both internal mammary arteries, has the potential to allow complete myocardial revascularization with viable arterial grafts.

Key Words: grafting • revascularization • arteries • coronary disease

	Introduction

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Because of the superior long-term performance of the IMA as a CABG,^{1 2 3 4 5} it is now the preferred conduit for myocardial revascularization, and there is increasing use of bilateral IMA grafts, particularly in young patients. Unfortunately, it is often not possible to reach coronary arteries on the posterior surface of the heart with either in situ (pedicle) or free IMA grafts.^{6 7 8} Although multiple sequential anastomoses can be used in some cases to revascularize more than one coronary artery per IMA graft, there is a clear need for a third arterial conduit. Furthermore, there are increasing numbers of patients who are anatomically suitable for primary or reoperative CABG surgery but who lack sufficient quantity or quality of conventional conduits, IMA and saphenous vein. Other alternative conduits have had disappointing short-term and long-term results.^{9 10 11 12}

The right GEA, a branch of the gastroduodenal artery, was used in the era of indirect myocardial revascularization as a Vineberg-type implant.^{13 14} In 1987, we reported its first use (June, 1984) as a direct CABG.¹⁵ Others have adopted the technique^{16 17 18 19 20 21 22} and have confirmed our encouraging early results.

	Methods

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Patients
Between June 1984 and September 1994, 126 patients underwent GEA-to-CABG surgery in this center. Except for five operations, all were performed by one surgeon. There were 111 men and 15 women, aged 32 to 78 years (mean±SD age, 53.0±9.4 years). All but 4 patients had two- or three-vessel coronary disease, and 108 patients (86%) were in New York Heart Association (NYHA) functional class III or IV. Six patients (5%) had previously undergone CABG surgery.

Indications for the use of the GEA evolved during the series. During the first 2 years, the GEA was used in nine patients in whom there was insufficient long or short saphenous vein of adequate quality or extensive disease of the ascending aorta. Subsequently, the indications have been extended to include younger patients with accelerated atherosclerosis, where poor results with vein grafts can be predicted.²³ In particular, we have considered some patients to have coronary anatomy particularly suitable for complete arterial revascularization, severe proximal stenosis or occlusion of coronary arteries within reach of, and compatible in size with, pedicled IMA and GEA grafts. Contraindications to its use included previous gastric surgery, morbid obesity, and advanced patient age, unless no other conduit was available. Where possible, we also avoided the use of multiple arterial grafts in patients with unstable angina that could not be medically stabilized before surgery.

Operative Technique
Through a minimally extended median sternotomy incision, the GEA was identified by palpation and the pedicle mobilized from the midpoint of the greater curvature of the stomach back to the level of the pylorus. The omental border was dissected with low intensity electrocautery, and the few significant arterial and venous branches were clipped or ligated. Gastric branches were individually clipped (or ligated) after careful dissection of surrounding tissue, thus allowing considerable elongation of the pedicle. Since the vast majority of branches from the GEA are to the stomach, the resulting row of clips or ligatures along one edge provided an easy means of orientating the pedicle later in the procedure, to avoid twisting. After systemic heparinization, all arterial grafts were divided distally, and flow was assessed. They were occluded distally with an atraumatic clamp to allow continued perfusion of the pedicle and wrapped in gauze soaked with dilute papaverine hydrochloride solution. Additional pharmacological dilatation with intraluminal nitroglycerin or papaverine was rarely used.

The GEA pedicle was routed either anterior or posterior to the pylorus, depending on which appeared to be the more direct approach, and then brought loosely through a cruciate incision in the diaphragm adjacent to the atrioventricular groove. The pedicle then lay parallel to the atrioventricular groove, ready for grafting to the right coronary artery, its posterior descending or left ventricular (LV) branches, or to distal circumflex branches (Fig 1).

View larger version (29K): [in this window] [in a new window]   Figure 1. Surgeon's view of completed gastroepiploic to coronary bypass (with retropyloric placement of the graft pedicle).

Standard techniques of cardiopulmonary bypass were used, with systemic hypothermia to 27°C to 34°C depending on the number of grafts to be performed. Cold blood cardioplegic arrest was used in all but the first 21 patients. Spontaneous hypothermic ventricular fibrillation and local coronary occlusion were used in 1 patient whose ascending aorta could not be safely cross-clamped.

Coronary anastomoses for both IMA and GEA grafts were performed with the aid of x3.5 optical magnification, using an open technique with continuous 7-0 or 8-0 Prolene suture at both the heel and toe of the graft. Graft pedicles were anchored to the epicardium adjacent to the anastomosis with interrupted 5-0 Prolene sutures to prevent anastomotic twisting or tension.

The size of the GEA at the site of the distal anastomosis ranged from 1.25 to 2.5 mm and was usually just under 1.5 mm in internal diameter. Early in the series, free flow was recorded and ranged from 60 to 120 mL/min, comparable with the IMA.

The GEA was used to graft the distal main right coronary artery in 25 patients, its inferior LV branch in 2 patients, the posterior descending artery in 90 patients, branches of the circumflex system in 8 patients (2 as a free aortocoronary graft), and the LAD in 1 patient. All but 2 patients had pedicled GEA bypass grafts. Additional grafts were placed in 122 patients, a mean of 2.9 (range, 1 to 5) grafts per patient. One hundred and twenty-three vessels were grafted with the left IMA, and there were 75 right IMA grafts, but only 19 saphenous vein grafts were used. Graft distribution is detailed in the Table.

View this table: [in this window] [in a new window]   Table 1. Grafts Performed

	Results

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Early Results
There were two hospital deaths (1.6%) (stroke, arrhythmia), and two patients (1.6%) required reexploration for intrathoracic bleeding; both had undergone concomitant bilateral IMA grafting and were bleeding from chest-wall branches. There were no complications related to the abdominal component of the operation. Mean postoperative hospital stay was 7.5±2.0 days. Seventy-four patients (59%) were discharged on or before the seventh postoperative day.

Late Results
The 124 hospital survivors have been followed for 2 to 120 months after operation (mean, 41.4 months). Twenty-nine patients have been followed for more than 5 years, and 49 for more than 4 years. Only 1 has been lost to follow-up. There have been 3 late deaths, at 34 months (cardiac), 50 months (pulmonary embolus), and 84 months (probably noncardiac). Fig 2 shows an actuarial survival curve for the group of 124 patients. All patients were symptomatically improved after the operation and are in NYHA functional class I or II. There have been no long-term complications related to the use of the right GEA. One patient has required laparotomy for abdominal aortic aneurysm resection, and another has undergone laparoscopic cholecystectomy, both without incident.

View larger version (10K): [in this window] [in a new window]   Figure 2. Graph shows actuarial survival curve of patients after CABG with right GEA (86.6±9.4% at 10 years).

Graft Patency
Forty-four patients (37%) have undergone graft and coronary angiography at postoperative intervals from 7 days to 81 months (mean, 10.6 months). The first 8 patients were restudied before hospital discharge, but resource limitations have not allowed a more extensive elective angiographic follow-up program to date.

GEA grafts were opacified by techniques ranging from semiselective celiac axis flush to selective gastroduodenal catheterization. Patency was clearly demonstrated in 35 GEA grafts and was strongly implied by native coronary angiography in a further 6 patients. In these cases, the grafted vessel, which had previously filled from collaterals, was "missing," and there was no change in regional wall motion. In 3 patients, direct or indirect evidence of graft patency could not be obtained for purely technical reasons. Only 1 GEA graft was demonstrated to be occluded. All 4 GEA grafts studied more than 5 years postoperatively were patent. Fig 3 shows a patent GEA graft to the right coronary artery in patient No. 1 at 81 months, filling a markedly irregular right coronary system. Fig 4 shows a patent GEA graft to the posterior descending artery in patient No. 21 at 63 months.

View larger version (133K): [in this window] [in a new window]   Figure 3. Right GEA graft to the right main coronary artery at 81 months.

View larger version (163K): [in this window] [in a new window]   Figure 4. Right GEA graft to the posterior descending artery at 63 months.

	Discussion

Top Abstract Introduction Methods Results Discussion References

 
The long-term patency rate of the IMA as a coronary bypass graft compared with autologous saphenous vein¹ has led to a dramatic change in the practice of CABG surgery. When one or more IMA grafts are used, there is improved long-term survival, prolonged symptomatic benefit, freedom from reoperation, and fewer late cardiac-related events.^{2 3 4 5} Although this appears to be mainly attributable to the effect of a patent IMA graft to the LAD, no definite survival advantage has yet been shown with bilateral versus single IMA grafting, and there is growing interest in the concept of complete arterial revascularization. However, despite the use of both IMAs and the success of sequential IMA grafts,²⁴ this is not possible in three-vessel disease without the use of a third arterial graft. Furthermore, the right IMA rarely reaches beyond the crux, even as a free graft.

The GEA, a branch of the gastroduodenal artery (usually arising from the right hepatic and celiac axis), is an artery that appears, like the IMA, to be relatively free of atherosclerosis.^{16 25} It was used in the Vineberg era for indirect myocardial revascularization,¹³ with demonstrated short-term angiographic patency.¹⁴ Like the long-term patency seen in IMA implants, 16- to 18-year angiographic patency has been seen in the occasional right GEA implant studied (G.M. FitzGibbon, National Defence Medical Centre, Ottawa, personal communication, 1993).

When appropriately harvested, the GEA can reach all arteries on the posterior and posterolateral walls of the heart as a pedicle or in situ graft. Previous nongastric abdominal surgery is not a contraindication to its use provided that adhesions are not too dense to allow complete mobilization of the pedicle. Technically, the GEA is particularly suitable as a graft to the posterior descending artery, which is usually relatively free of atherosclerotic disease (compared with the main right coronary artery), and provides an excellent size match. With experience, harvesting the GEA pedicle takes no longer than harvesting the IMA (and is often quicker). Although the distal anastomosis can be technically demanding, it is not usually more difficult than an IMA-to–distal circumflex graft. Our technical strategy for complete arterial revascularization reflects a strong bias toward pedicled rather than free grafts. Thus, the GEA was used mostly as a graft to the posterior coronary circulation (Table). The left IMA was most often grafted to the LAD and the right to the circumflex system, usually through the transverse sinus of the pericardium. An obvious advantage to this approach is the absence of a graft crossing the midline anteriorly. Less frequently, the left IMA was used for a distal circumflex branch, especially on a large heart, and when the GEA had been used for the posterior descending artery. In these cases, the left IMA was brought into the pericardium either just anterior or posterior to the left phrenic nerve, and the right IMA was taken anteriorly across to the LAD.

Although the small laparotomy and gastric manipulation requires postoperative nasogastric tube drainage, occasionally for several days, overall postoperative stay has not been prolonged. Lytle et al's early experience,¹⁸ where one third of the patients required hospitalization for more than 10 days, probably reflected their patient population (25% reoperations). In our experience, patients have been a little slow in initial mobilization but catch up rapidly without the discomfort of leg incisions. We have been impressed with the lack of short-term and long-term complications related to use of the GEA. Indeed, in two-vessel disease, particularly in diabetics, use of the GEA and one IMA may avoid the increased morbidity of bilateral IMA harvesting.

While two of our patients have undergone subsequent abdominal surgery without incident, GEA bypass grafts are clearly at risk of inadvertent damage during upper abdominal surgery, whether routed anterior or posterior to the stomach. Both the patients and their physicians should be educated about the use of this conduit. We believe that if its presence is known the GEA graft should be readily palpable and damage therefore avoidable. Apart from the concept of total arterial revascularization, which may be most relevant in a younger age group, there are patients whose coronary anatomies are suitable for primary or reoperative bypass surgery but who have inadequate conventional conduits, saphenous vein or IMA. Short-term results of other alternative conduits have been quite poor.^{9 10 11 12} Although free radial artery grafts are being reappraised, their long-term fate, like that of inferior epigastric grafts, is unknown. On the other hand, we believe that the use of the GEA as an alternative coronary bypass graft is now well established.

Angiography of GEA bypass grafts can be technically difficult, particularly since specialized catheters were not available early in our experience. Graft patency in our study was consistent with that reported by others.^{21 22} It should be noted that all four of our GEA grafts studied more than 5 years postoperatively were patent. In one of these patients, obvious progression of distal atherosclerosis was seen in two coronary systems but not in the GEA or IMA grafts.

We also noted catheter-induced spasm in several cases that was readily relieved by administration of intraluminal nitroglycerin. Indeed, while the GEA appears to be pharmacologically similar to the IMA,^{26 27} it is significantly more muscular. In unpublished data from our institution, ring segments of GEA developed nearly three times the grams force tension compared with IMA segments of the same size (K. Nakatsu, J. Pym, S. Witte; unpublished data). Thus, whether or not it is inherently more prone to develop spasm, the GEA is likely to be more vulnerable to the effects of spasm. Because of this, as much as the additional pre-bypass time, we have been reluctant to use the GEA or indeed more than one arterial graft in highly unstable patients unless satisfactory venous conduit was unavailable. It remains to be seen whether intraluminal treatment with, for example, newer calcium channel blockers may prevent perioperative spasm.

In conclusion, our short-term, intermediate, and long-term results demonstrate the continuing suitability of the right GEA as a conduit for CABG surgery. The use of the right GEA as a graft to coronary arteries on the posterior wall of the heart in conjunction with one or both IMAs has the potential to allow complete myocardial revascularization with viable arterial grafts.

	Selected Abbreviations and Acronyms

 

CABG = coronary artery bypass graft GEA = gastroepiploic artery IMA = internal mammary artery LAD = left anterior descending coronary artery

	References

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This Article Abstract Alert me when this article is cited Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Alert me to new issues of the journal Download to citation manager Request Permissions Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Pym, J. Articles by Parker, J. Search for Related Content PubMed Articles by Pym, J. Articles by Parker, J.