Combined coronary artery bypass grafting and bilateral renal revascularization for unstable angina and impending renal failure

Transcription

1 Combined coronary artery bypass grafting and bilateral renal revascularization for unstable angina and impending renal failure Robert A. McCready, MD,* Harry Siderys, MD, ~ Peter R. Foster, MD,*~ and Bruce M. Goens, MD,** Indianapolis, Ind. The purpose of our article is to describe a patient with severe hypertension and moderate renal insufficiency, unstable angina, and a 6 cm abdominal aortic aneurysm. A previous aortogram had demonstrated severe bilateral renal artery stenoses. Cardiac catheterization demonstrated severe coronary disease. After cardiac catheterization acute renal failure and pulmonary edema requiring dialysis developed in the patient. In addition, evidence of impending myocardial necrosis developed. Because of the critical nautre of the myocardial and renal ischemia it was necessary to perform combined myocardial and renal revascularization rather than staged procedures. At the time of coronary artery bypass grafting, a vein graft was anastomosed to the right coronary artery vein graft and nmneled through the diaphragm into the abdomen to revascularize both renal arteries. After surgery renal function gradually improved, and no further dialysis was required. The abdominal aortic aneurysm was repaired at a subsequent operation. At 2-year follow-up all grafts remained patent. The serum creatinine is 1.2 mg/di. Although most patients with combined coronary artery disease and renal artery disease can be treated with staged operations, our procedure may be of value in patients in whom staged procedure are not feasible and in whom the infrarenal aorta is severely diseased or aneurysmal. (J VASe SIZRG 1990;12:241-5.) Coronary artery bypass surgery is of proven benefit for patients with unstable angina and severe coronary artery disease. Successful myocardial revascu- ~arization may also improve ventricular function in patients with viable but ischemic areas of myocardium. Similarly, patients with renal insufficiency and :-~pending renal failure, as a result of critical and often preocclusive renal artery stenoses, may have gratifying results from renal revascularization both in terms of ameliorating their hypertension and preserving or improving renal function. The purpose of this article is to describe a patient with severe hypertension and moderate renal insufficiency, unstable angina, and thoracic and abdominal aortic aneurysms (AAAs). Because of the critical degree of both the myocardial and renal ischemia it was necessary to perform combined myocardial and renal revascularization rather than staged procedures. From the Departments of Surgery~ and Cardiology, ~ Methodist Hospital of Indiana, Inc., Indianapolis. Presented at the Fourteenth Annual Meeting of the Southern Association for Vascular Surgery, Acapulco, Mexico, Jan , Reprint requests: Robert A. McCready, MD, Cardiovascular Surgical Associates, 1801 North Senate Blvd., Suite 755, Indianapolis, IN /6/22785 CASE REPORT A 74-year-old woman was admitted to the Methodist Hospital of Indiana on Sept. 28, 1987 for evaluation of unstable angina, severe hypertension associated with moderate renal insufficiency, an asymptomatic 6 cm AAA with associated iliac occlusive disease, and an asymptomatic 4 cm thoracic aneurysm. The patient had a 4-year history of hypertension, which had become increasingly more difficult to control. At the time of admission the patient was taking prazosin hydrochloride (Minipress), enalapril maleate (Vasotec), and labetalol hydrochloride (Normodyne). An aortogram performed 3 months before this admission demonstrated severe bilateral renal artery stenoses in addition to a 6 cm AAA with occlusion of the right common iliac artery (Fig. 1). The serum creatinine was 2.0 mg/dl at that time. A CT scan of the chest demonstrated a 4 cm descending thoracic aneurysm. It was elected to treat her hypertension medically because of her symptomatic coronary artery disease and numerous other medical problems. Subsequently, however, her angina became unstable and progressive renal failure developed prompting admission for further evaluation, The admission serum creatinine was 3.5 mg/dl (Fig. 2). A thallium-dypiridamole scan demonstrated significant ischemia in the inferior and anterolateral walls. The resting ejection fraction was 38%. With hydration, the serum creatinine decreased to 2.1 mg/dl over ~e next few days. Eight days after admission, cardiac 241

2 242 McCready et al. Journal of VASCULAR SURGERY Fig. 1. Aortogram demonstrates a preocclusive stenoses of both renal arteries (arrows). COMBINED CABG ~ BILAIYRAL RENAL I~VASCULARIZATION -) ~.0 tl ADM CC. OS OR.. DC AAA DC Sept. October December Fig. 2. Graph indicates the course of the patient's serum creatinine. ADM, Admission; CC, cardiac catheterization; DS, dialysis; OR, day of coronary and renal surgery; DC, discharge; AAA, date of AAA repair.

3 Volume 12 Number 3 September 1990 Combined coronary bypass renal bypass angina renal failure 243 Fig. 3. Transaxial view of the left coronary artery demonstrates high-grade stenoses of the left anterior descending (black and wbi~e arrow) and circumflex coronary arteries (black arrow). catheterization was performed, which demonstrated severe triple vessel coronary artery disease (Fig. 3). No ventriculogram was done so that the amount of contrast medium could be limited. One day after the cardiac catheterization, acute pulmonary edema developed in the patient. This edema was associated with a falling urinary output and a rise in the serum creatinine to 4.3 mg/dl. Electrocardiographic (ECG) and isoenzyme changes also developed suggestive of myocardial necrosis. A repeat ejection fraction was 24% compared to the admission value of 39%. Her urine output continued to decrease despite large amounts of diuretic agents. Two days after the cardiac catheterization, a Quinton hemodialysis catheter was inserted, and the patient was dialyzed in preparation for surgery. The following day the patient was taken to the operating room. A median sternotomy and upper abdominal midline incision were made. Before placing the patient on bypass, both renal arteries were exposed. The AAA was not disturbed. After cardiopulmonary bypass was instituted, saphenous vein grafts were anastomosed to the right coronary artery, left anterior descending artery, and the circumflex artery. A long segment of saphenous vein was then anastomosed in an end-to-side fashion to the right coronary artery vein graft and tunneled through a hole in the diaphragm into the lesser sac. The proximal left renal artery was ligated and the vein graft anastomosed in an end-to-end fashion to the distal left renal artery. Another segment of saphenous vein was then anastomosed to this vein graft in an end-to-side fashion and was subsequently anastomosed to the distal right renal artery with an endto-end anastomosis (Fig. 4). The patient was then weaned from cardiopulmonry bypass on dopamine. Flow measurements in the proximal tight coronary artery vein graft \\ Fig. 4. Artist's sketch demonstrates the method of revascularizing both renal arteries by use of the right coronary graft as the inflow source.

4 244 McCready et al. Journal of VASCULAR SURGERY Fig. 5. Two-year postoperative study demonstrates patent vein grafts to both renal arteries. were 230 nil/minute with a flow in the distal right coronary graft of 30 n-d/minute. The flow in the left renal artery vein graft was 170 ml/minute with a flow in the right renal artery graft of 95 ml/minute. After surgery the patient maintained good urine output. Dopamine was continued for several days at low doses to help maintain renal flow. A renal flow scan on the fourth postoperative day demonstraated good flow to both kidneys with decreased function bilaterally. Although no further hemodialysis was required, the serum creatinine remained in the 4 to 5 mg/dl range for the next 2 weeks (Fig. 2). On postoperative day 14, the serum creatinine began to decrease. At discharge on the eighteenth postoperative day the serum creatinine was 2.6 mg/dl with a blood urea nitrogen (BUN) of 57. A postoperative ejection fraction was measured at 39% with improved wall motion. The patient was readmitted i month later for repair of the AAA. The admission serum creatinine at that time was 2.1 mg/dl (Fig. 2). The aneurysm was repaired through a retroperitoneal approach on Dec. 1, The patient did well after surgery with further gradual improvement of renal function. The serum creafinine at discharge on 12/9 was 1.5 mg/dl. The patient has been followed for more than 2 years. Her hypertension is well controlled on Normodyne 200 mg twice a day, and the serum creatinine is 1.2 mg/dl. Because of some mild recurrent chest pain, a repeat cardiac catheterization was performed on Jan. 4, Both the left anterior descending and circumflex coronary grafts re- main patent. The proximal segment of the right coronary vein graft and the vein grafts to both renal arteries are widely patent (Fig. 5). The distal segment of the right coronary vein graft is occluded. At the initial cardiac catheterization in October 1987 the distal right coronary artery was small and quite diseased. DISCUSSION In addition to its salutory effect on relieving an~ gina pectoris, coronary artery bypass surgery may result in significant improvement in ventricular function in patients with ischemic but viable areas of myocardium. Our patient had critical coronary artery disease with evidence of incipient preoperative myocardial necrosis as manifested by the fall in ejection fraction accompanied by elevation of the creatine phosphokinasc isoenzymes. Pulmonary edema developed after the cardiac catheterization because of the patient's left ventricular dysfunction. Therefore urgent myocardial revascularization was deemed necessary. In addition to relief of her angina, after surgery the patient had a gratifying return of the ejection fraction to its original value. Improved ventricular wall motion was also demonstrated. Dean et al.1 have emphasized that unilateral renal artery stenosis alone does not produce azotemia. Significant bilateral renal artery stenoses must be present

5 Volume 12 Number 3 September 1990 Combined coronary bypass renal bypass angina renal failure 245 before overall renal function is adverscly affected. Combined aortic and bilateral renal revascularization procedures have been associated with mortality rates of 12% and 15% in two large series, 1,2 although O'Mara et al.3 recently reported a mortafity rate of 3% among 32 patients undergoing simultaneous aortic and bilateral renal revascularization. Among patients requiring renal revascularization, azotemia is an especially important risk factor for postoperative mortality. In the Cleveland Clinic experience, 2 the mortality rate was 19% for patients with a creatinine greater than 2 mg/dl. Among the azotemic patients (creatinine greater than 3 mg/dl) in the series of Dean et al) the mortality rate was 43%. In addition to the rather high mortality rate, the Cleveland Clinic reported a 15% incidence of ~liguric renal failure after bilateral renal revascularlzation. 2 Although patients with severe hypertension and azotemia may be at increased risk for significant morbidity and mortality after surgical revascularization, these patients are the ones most likely to benefit from renal rcvascularization. In a group of 10 patients with refractory hypertension and azotemia who had bilateral renal artery stenoses or unilateral renal artery stenosis in a solitary functioning kidney, all patients had improvement on stabilization of renal function and improved control of hypertension after either surgical intervention or angioplasty, 4 We previously reported a series of 19 patients with severe hypertension and azotemia with a single functioning ischemic kidney who underwent surgical revascularization. 5 After surgery a statistically significant decrease was found in the mean diastolic pressure, mean serum :reatinine, and in the mean number of antihypertensive medications. Several other series have demonstrated significant improvement in renal function, especially among azotemic patients and improved control of hypertension. ~-8 With regard to our patient, our preference would have been to do staged procedures (coronary artery bypass surgery followed by resection of the aneurysm with concomitant renal revascularization). However, we thought that the risk of postoperative renal failure with myocardial revascularization alone would have been very high. Urgent myocardial revascularization was necessary because the patient was manifesting preinfarction myocardial ischemia. The patient's precarious cardiac status certainly would not have allowed us to proceed with renal revascularization alone (either with or without resection of the abdominal aneurysm) without prior myocardial revascularization. Therefore combined myocardial and renal revascularization was necessary. In an effort to minimize the magnitude of the operation, we elected not to repair the aneurysm at this operation. An alternative method of revascularizing both kidneys without having to resect the aneurysm would have been to use the hepatic and splenic arteries as inflow sources for bypasses to the right and left renal arteries, respectively. Excellent results have been reported with these procedures. 9 However, we thought that using the hepatic and splcnic arteries as inflow sources would have required additional dissection and would not have provided any hemodynamic benefit compared to using the right coronary vein graft as the inflow source. The excellent results obtained in our patient suggest that our procedure may be of value in selected patients with life-threatening myocardial and renal ischemia in need of combined revascularization. The authors express their appreciation for the excellent assistance of Bert Neu in the preparation of this manuscript. REFERENCES 1. Dean RH, Keyser JE, Dupont WD, Nadeau JN, Meacham PW. Aortic and renal vascular disease: factors affecting the value of combined procedures. Ann Surg 1984;200: Tarazi R, Hertzer NR, Beven EG, O'Hara PG, Anton GE, Krajewski LP. Simultaneous aortic reconstruction and renal revascularization: risk factors and late results in eighty-nine patients. J VAsc SURG 1987;5: O'Mara CS, Maples MD, Kilgore TL, et al. Simultaneous aortic reconstruction and bilateral renal revascularization. Is this a safe and effective procedure? J VAsc SURG 1988;8: Ying CY, Tifft CP, Gavras H, Chobunian AV. Renal revascularization in the azotemic hypertensive patient resistant to therapy. N Engl J Med 1984;311: McCready RA, Daugherty MED, Nighbert EJ, Hyde GL, Freedman AM, Ernst CB. Renal revascularization in patients with a single, ischemic kidney. J VAsc SURG 1987;6: Dean RH, Lawson JD, Hollifield JW, Shack RB, Polterauer P, Rhancy RK. Revascularization of the poorly functioning lddney. Surgery 1979;85: Dean RH, England R, Dupont WD, et al. Retrieval of renal function by revascularization: study of preoperative outcome factors. Ann Surg 1985;202: Whitehouse WM, Kazmers A, Zelenock GB, et al. Chronic total renal artery occlusion: effects of treatment on secondary hypertensive and renal function. Surgery 1981;89: Moncure AC, Brewster DC, Darling RC, Atnip RG, Newton WD, Abbott WM. Use of the splenic and hepatic arteries for renal revascularization. J VASC SLTRG 1986;3: