Right gastroepiploic artery as a coronary bypass graft

Long great saphenous vein grafting as temporary coronary bypass for extended left hepatectomy: report of a case

The right gastroepiploic artery (RGEA) has been used in coronary artery bypass grafting (CABG) as an alternative graft. In particular abdominal surgeries, surgery is required to rescue the graft flow into the coronary artery. A 77-year-old male with a history of CABG using RGEA was admitted with a diagnosis of a large hepatocellular carcinoma (HCC) occupying the whole caudate lobe. Preoperative coronary angiography indicated that the graft from the right internal mammary artery to the proximal left circumflex artery was obliterated among three branch bypasses. Following laparotomy, a great saphenous vein was harvested and delivered from the right axial artery to the RGEA graft over the thoracic wall, and the RGEA graft was ligated and divided. Subsequently, extended left hepatectomy was safely performed. Following hepatectomy, the RGEA graft was restored to the former condition, and the temporary graft was removed. After overcoming hyperbilirubinemia, the patient was discharged on postoperative day 28. This experience indicates that temporary bypass using the long great saphenous vein is effective and safe during long and invasive surgeries.

The Deep Inferior Epigastric Artery: Anatomy and Applicability as a Source of Microvascular Arterial Grafts

BACKGROUND

Arterial grafts are superior to venous grafts when used for microvascular grafting procedures. Advantages of arterial grafts include anatomical taper, improved size match, improved handling characteristics, and superior patency rates. The deep inferior epigastric artery may be used as a source of microvascular graft to replace damaged or diseased arterial segments. By studying cadaver dissections, it is possible to estimate the clinically usable length and caliber of the deep inferior epigastric artery.

METHODS

Thirty-four preserved cadavers were dissected and 63 deep inferior epigastric arterial systems were removed and measured. The deep inferior epigastric artery was used as an arterial conduit to bypass across nine wrists in eight patients.

RESULTS

The mean length from the external iliac artery to the point at which the vessel displayed an external diameter of 1 mm was 14.06 +/- 2.54 cm. The deep inferior epigastric artery has been used in nine clinical cases as an arterial conduit to bypass distal to the wrist. All nine bypasses were patent 1 year postoperatively, without donor-site complication.

CONCLUSION

The deep inferior epigastric artery is a morphologically reliable and clinically useful source of arterial grafts.

Comparison of the flow capacity of free arterial grafts and saphenous vein grafts for coronary bypass surgery

There is controversy regarding the flow reserve and capacity of arterial conduits to meet the needs of the myocardium. This study compared flow in 22 free arterial bypasses to 15 saphenous vein grafts in procedures involving twenty patients. To assess the maximal flow possible, (flow capacity) graft flow was measured using a calibrated pump while perfusing blood cardioplegia through the conduit and distal anastomosis during cardiac arrest (no competitive flow). This assessment was subsequently confirmed with whole blood during myocardial contraction while on cardiopulmonary bypass. Twenty-two free arterial grafts were used; 15 right internal mammary artery grafts, 4 right gastroepiploic grafts, 3 inferior epigastric artery grafts, and 3 sequential bypasses. Free arterial conduit flow ranged from 50 to 180cc/ml, with an average flow of 102.5+/-28.5ml/min as compared to saphenous vein graft flow, 102+/-28 ml/min. No correlation of flow with the conduit size was found. Arterial graft flow demonstrated a mild correlation with the size of the native coronary artery bypassed (R=0.47, P</=0.02).

CONCLUSIONS

Basal flow through free arterial grafts is equivalent to saphenous vein grafts and is primarily determined by the native coronary vessels. The flow reserve for free arterial conduits is more than adequate for coronary bypass surgery.

The current status of myocardial revascularization: changing trends and risk factor analysis

From November 1989 to December 1994, we performed 2264 bypass procedures. Data were collected prospectively. The population was divided into three subgroups: group 1 = single internal mammary artery (IMA) +/- veins (n = 1584); group 2 = veins only (n = 503); and group 3 = two or more arterial conduits +/- veins (n = 177). Patients who received only saphenous vein conduits (group 2) were significantly older (66.7 +/- 8.9 years) than either group 1 (60.3 +/- 8.3 years) or group 3 (51.6 +/- 9.2 years). Furthermore, this cohort group had the highest percentage of females (28.6%), urgent cases (43.5%), preoperative myocardial infarction (MI) (18.5%), and redo surgery (5.4%). In contrast, patients who received two or more arterial conduits were 94.9% male, and had the lowest incidence of urgent cases (18.1%) and redo surgery (0.5%). Mortality was 1.4% in group 1 and 3.2% in group 2; there were no deaths in group 3. Furthermore, group 2 patients had the highest incidence of perioperative MI (6.6%), low output syndrome (22.1%), intra-aortic balloon pump (IABP) assist (6.2%), and stroke (2.7%). By multivariate logistic regression analysis (odds ratio in parentheses), redo surgery (7.92), preoperative IABP (5.53), poor LV function (4.01), renal impairment (3.94), and advanced age (2.12) were all predictors of operative mortality. When mortality and morbidity (death, infarction, low output syndrome, IABP assist) were combined, regression analysis revealed that in addition to the above variables, female gender and cold cardioplegia were also independent predictors of combined mortality and morbidity. Resource utilization was determined for the three patient groups. There was concern that the increased technical demands of multiple arterial grafting along with longer periods of aortic occlusion and pump times may lead to increased complications and prolonged hospital stay. However, we found that group 3 had the lowest ventilation time, intensive care unit stay, and hospital stay. The results no doubt were influenced by case selection. Whether or not this approach to revascularization will increase long-term survival and freedom from reoperation will require further study.

Diffuse vasospasm following stenting of a free gastroepiploic artery graft: resolution with balloon angioplasty and intensive medical therapy

Vasospasm following balloon angioplasty of gastroepiploic artery bypass grafts can be prevented or reversed with vasodilators. In our patient, stent deployment for ostial stenosis of a free gastroepiploic artery graft was accompanied by severe, diffuse spasm and a change in graft configuration that required both intensive medical therapy and balloon angioplasty for resolution.

Right gastroepiploic-to-coronary artery bypass. The first decade of use

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.

Laparotomy after using the gastroepiploic artery graft: retrogastric versus antegastric route

BACKGROUND

Most cardiac surgeons prefer the antegastric route for the right gastroepiploic artery (RGEA) graft. When placed anterior to the stomach, the RGEA pedicle may adhere to the greater omentum, or to the anterior abdominal wall, and may be injured during future abdominal operations.

METHODS

To avoid this potentially lethal complication, we prefer to place the RGEA graft behind the stomach and the left lobe of the liver. In our experience with 144 patients in whom the retrogastric route was used, 7 patients required an abdominal operation (2 had cholecystectomy, 2 had a partial colectomy, 1 had repair of paraesophageal hernia, and 2 had repair of abdominal wall complications). There was no need to dissect the RGEA graft in any of these patients.

RESULTS

There was no evidence of myocardial ischemia or other complications during or after the operation in any patient.

CONCLUSIONS

Based on our experience and the fact that any injury to the RGEA graft may have catastrophic consequences, we strongly advocate the retrogastric route to minimize the risk of injury to the RGEA graft during a subsequent laparotomy.

Gastroepiploic artery as an in situ coronary artery bypass graft: evaluation of MRI and colour Doppler ultrasound in follow-up

The right gastroepiploic artery, increasingly used as an in situ coronary artery bypass graft, has good long-term patency. This study aimed to assess the accuracy and limitations of magnetic resonance imaging (MRI) and colour Doppler ultrasound (US) in postoperative follow-up of such cases. In eight consecutive patients (6 men, 2 women, mean age 57 years), conventional angiography, MRI and US were performed to evaluate graft patency. Colour Doppler US, performed within a week of the operation, correctly detected flow in three patent grafts. MRI (1.5 tesla) was performed c. 17 months after surgery, using a spine coil and a coronal two-dimensional Flash-type imaging sequence. At angiography six of the eight gastroepiploic artery grafts were patent, and two were occluded. The sensitivity and specificity of MRI were 100%. This accuracy makes MRI a promising method for noninvasive post-operative evaluation of right gastroepiploic artery graft patency.

Right gastroepiploic artery conduit use in myocardial revascularization

The majority of surgeons use the saphenous vein or internal mammary artery as conduits in coronary artery bypass grafting (CABG). Improved long-term patient survival rates after CABG have increased the need for alternative conduits in reoperations for myocardial revascularization. In the past 20 years, surgeons have begun using the right gastroepiploic artery (GEA) as an alternative conduit in CABG. Perioperative nursing care of patients undergoing right GEA grafting for myocardial revascularization includes documentation of patient problems and nursing actions taken; preoperative patient assessment and teaching; intraoperative management of patient positioning, temperature, and skin integrity; and postoperative care to maintain the patient's hemodynamic stability and avoid complications.

Clinical experience with the right gastroepiploic artery in coronary artery bypass grafting

The excellent long-term results with the internal mammary artery for coronary artery bypass grafting have prompted the search for other conduits with similar characteristics. From December 1989 to December 1991, the right gastroepiploic artery (RGEA) has been used as an in situ graft to the posterior descending coronary artery in 51 patients at the Montreal Heart Institute. The patients' age averaged 50 +/- 11 years. Three-vessel coronary artery disease was present in 41 patients and two-vessel disease in the remaining 10 patients. In all but 1 patient, bilateral internal mammary artery grafting was performed in addition to RGEA grafting. The number of grafts per patient averaged 3.2 +/- 0.8. There was no operative mortality. Morbidity was minimal with only myocardial infarction and a pleural effusion in 1 patient. In 1 patient, a splenectomy had to be performed because of iatrogenic tear during dissection of the RGEA. The average hospital stay was 8.2 +/- 2.6 days. Enteral nutrition was resumed on average 2 days after operation. Angiographic evaluation of RGEA grafts was performed before discharge or within the first month after surgery in 31 patients. In 28 patients (28/31, 90%) the RGEA graft was patent, two grafts were occluded, and in the remaining patient, the graft could not be visualized due to technical difficulties during angiography. A second angiographic evaluation was performed in 5 patients, 1 year after operation. Four RGEAs were patent and 1 was occluded. Clinical follow-up averaged 4 months (range 1 to 15 months).(ABSTRACT TRUNCATED AT 250 WORDS)

Cryopreserved allograft veins as alternative coronary artery bypass conduits: early phase results

Traditional autologous conduits are sometimes unavailable or unsuitable to permit total revascularization during coronary artery bypass grafting. In these patients the results of using nonautologous alternative conduits has been disappointing. Encouraged by the excellent long-term results seen with cryopreserved allograft valves, a clinical protocol was developed to evaluate the use of a commercially cryopreserved allograft saphenous vein (CPV). Our protocol consisted of using CPV when left internal mammary arteries and autologous saphenous vein grafts were unavailable or unsuitable for complete revascularization. Blood group (ABO) typed CPVs were thawed and implanted as required using standard surgical techniques. From December 1989 through June 1991, 19 of 1,602 patients who underwent coronary revascularization had CPVs implanted (1.2%). There were no operative deaths. An attempt was made to evaluate the patency of all grafts with coronary arteriography or ultrafast computed tomographic scans. Fourteen patients were available for patency evaluation. Patency rate in the 14 patients studied at a mean of 7 +/- 2 months (range, 2 to 16 months) were: internal mammary artery, 93% (14/15); saphenous vein graft, 80% (4/5); and CPV, 41% (7/17). The patency of the CPV was significantly less than the patency rate for the saphenous vein and internal mammary artery (p = 0.004). We conclude that the short-term patency rate of CPVs is inferior to that of autologous vessels. Due to its poor patency, we recommend that CPV should only be used when no other autologous conduit is available.

Color Doppler imaging of the right gastroepiploic artery as an in situ coronary artery bypass graft

In recent years the right gastroepiploic artery (GEA) has been used as an in situ graft in coronary artery bypass grafting (CABG). The specific anatomical course of the GEA graft enables the use of color Doppler imaging technique to evaluate its patency. The results in 21 patients demonstrate the efficiency of this technique; postoperative angiography to establish patency can therefore be avoided.

Retrogastric versus antegastric routing and histology of the right gastroepiploic artery

To maximize use of the right gastroepiploic artery in myocardial revascularization 11 cadavers were studied to determine the shortest route (retrogastric versus antegastric) of the right gastroepiploic artery from its origin to the recipient coronary artery. Any coronary artery could be reached with an in situ right gastroepiploic artery. There was no significant difference between the retrogastric and antegastric routes for any coronary artery, although the former generally is slightly shorter to the vessels on the posterior surface of the heart and the latter to vessels on the anterior surface of the heart. Histological examination of the right gastroepiploic artery in its proximal, mid, and distal segments showed a similar width of intima and media and invariably an almost purely muscular media. Based on the histological similarity of the right gastroepiploic artery to the coronary artery, some scepticism toward liberal use of the right gastroepiploic artery, especially if used as a free graft, is warranted until clinical studies on its long-term patency have been performed.

PTCA of gastroepiploic bypass

A technique for percutaneous transluminal coronary angioplasty (PTCA) of gastroepiploic bypass is described using standard PTCA devices. Severe spasm of gastroepiploic bypass occurred. Modification of guide catheter position is suggested to avoid inducing gastroepiploic bypass spasm.

Total arterial revascularization of the heart using both mammary arteries and the right gastroepiploic artery

From April 1988 to April 1989, nine patients (seven men and two women) with coronary three-vessel disease and disabling angina underwent elective myocardial revascularization. None of the patients had available veins because of previous bypass procedures (three) or extensive varicosis (six). On standard cardiopulmonary bypass and cardioplegic arrest the right and the left mammary arteries (RIMA, LIMA) and the right gastroepiploic artery (RGEA) were anastomosed each to a major coronary branch (none of them as free graft) in each patient. All patients survived the operation but one, who died 2 weeks after the operation of a bilateral pneumonia. Autopsy revealed patent anastomoses. One patient had to be reexplored for bleeding. Two patients required temporary inotropic support. There was no perioperative myocardial infarction. All survivors were discharged home in an average of 18.7 days after the operation, are free from angina, and all have negative stress tests (mean follow-up 7.7 months) but one with severe coronary atherosclerosis who experiences slight exertional angina despite good patency of the grafts. Five patients were recatheterized after a mean interval of 5.4 months after operation revealing in all cases patent anastomoses. Total revascularization of the heart with arterial grafts is feasible, safe, and it could become the method of choice if patency persists in the long run.

Internal mammary artery revascularization in the patient on long-term renal dialysis

Twenty-six patients on long-term renal dialysis underwent coronary artery bypass grafting. The patients were divided into two groups: group 1, (16 patients) saphenous vein bypass grafts, and group 2, (10 patients) internal mammary artery in combination with saphenous vein bypass grafts. Both groups were similar in terms of cardiac hemodynamics and previous number of myocardial infarctions, though more group 1 patients were in New York Heart Association class III or IV. Patients in group 1 received 2.9 bypass grafts per patient; patients in group 2 received 4.0 bypass grafts per patient (4 with bilateral mammary arteries). No wound healing problems occurred in either group. Blood replacement was similar for both groups (group 1, 5.5 units/patient; group 2, 5.3 units/patient). More platelets were given to group 1 patients (16.2 units/patient) than group 2 patients (3.1 units/patient). We conclude that use of the internal mammary artery in patients on long-term renal dialysis does not alter wound healing or increase blood loss in this subset of patients.

Percutaneous transluminal coronary angioplasty of gastroepiploic artery graft

The right gastroepiploic artery is being used as a third arterial conduit for coronary artery bypass surgery. Presented here is a case demonstrating successful percutaneous transluminal coronary angioplasty of the gastroepiploic artery graft. This successful accomplishment may avoid repeat surgical revascularization in case of failure of the gastroepiploic artery graft, hence may encourage people to use it more often.

Myocardial revascularization for the third time. Clinical characteristics and follow-up

Twenty-five patients presenting for a third revascularization procedure were retrospectively reviewed at Loyola University Medical Center, Maywood, IL. This represents 0.5 percent of the total revascularization cases over a five-year period extending from 1985 through 1989. Perioperative mortality was none, and seven complications occurred in six patients. Internal mammary arteries were used for revascularization in 60 percent of this group. Follow-up reveals that only one patient has died secondary to an arrhythmia. All patients except one are symptomatically improved, and 18 patients remain angina free at a mean follow-up of 22.3 months. It is therefore concluded that patients are clinically improved with a third revascularization, and this procedure should be offered as an effective means of treatment.

Arteriosclerosis of the gastroepiploic and internal thoracic arteries

Arteriosclerosis of the right gastroepiploic artery (GEA) and the internal thoracic artery (ITA) were compared by pathological observation. Specimens were obtained from 35 patients who underwent coronary artery bypass grafting with simultaneous use of these two kinds of arterial grafts. Degree of arteriosclerosis was classified in five categories: 0, normal; 1, luminal narrowing less than 25%; 2, luminal narrowing between 25% and 50%; 3, luminal narrowing greater than 50%; and 4, overt atherosclerosis with ulceration or calcification. The number of arteries with degree 0, 1, 2, 3, and 4 was 16 (46%), 15 (43%), 3 (9%), 0, and 1 (3%) in GEA and 27 (77%), 8 (23%), 0, 0, and 0 in ITA, respectively. Incidence of degree 0 was higher in ITA, but differences were not significant. The mean wall thickness was 0.30 +/- 0.13 mm in GEA and 0.21 +/- 0.07 mm in ITA (p less than 0.05). In 23 patients who underwent postoperative angiography, all 46 arterial grafts were patent without focal stenosis. We conclude that GEA has slightly more intimal thickening than ITA, but significant luminal narrowing caused by arteriosclerosis is rare. Gastroepiploic artery can be expected to be a suitable conduit for coronary artery bypass grafting.

Myocardial revascularization with three native in situ arteries. Gastroepiploic and bilateral internal mammary artery grafting

Three native arteries were used for coronary artery bypass grafting in six patients in whom complete revascularization was not feasible because of varices or previous venous stripping. The right gastroepiploic and both internal mammary arteries were placed as pedicled conduits, and four patients additionally received a total of six vein grafts available from the greater or lesser saphenous system. Surgical complications were minimal and complete relief from angina was obtained in all patients, even in maximal stress testing. All 24 grafts were angiographically checked: 23 (96%) were patent and one gastroepiploic artery was occluded. All patients had at least three patent grafts. These native arteries are excellent conduits when suitable veins are not available. They should also be used on individual indications to replace occluded grafts.

Indications for and risks in reoperation for coronary artery disease

Seventy-one coronary artery bypass grafting (CABG) reoperations were performed during a 17-year period, comprising 2.7% of all CABG operations. The main indication (in 87%) was vein graft failure alone or combined with other causes. Progression of disease in native coronary arteries was the sole indication in only 4 of the 71 cases. There were seven perioperative deaths, mainly due to myocardial infarction. Significant perioperative complications arose in 36 cases, including intraoperative lesion of a previous left internal mammary graft (16.2%) or of the right ventricle or anterior descending branch of the left coronary artery (2.8%). Postoperative low output syndrome appeared in 13 patients (18.3%), in seven of whom myocardial infarction was verified. Postoperative bleeding required resternotomy in six cases (9.1%). Because of the heightened operative mortality and morbidity risks, indications for redo CABG should be individualized. A well functioning internal mammary artery graft may be a relative contraindication. Accurate knowledge of the previous operation is essential and, especially in young patients, the possibility of reoperation should be taken into consideration at initial CABG.