Unilateral renal artery revascularization can salvage renal function and terminate dialysis in selected patients with uremia

Transcription

1 Unilateral renal artery revascularization can salvage renal function and terminate dialysis in selected patients with uremia Enrico Ascer, MD, Mark Gennaro, MD, and Dwain Rogers, MD, Brooklyn, N.Y. Revascularization of renal arteries to salvage glomerular function in patients with chronic renal failure is performed infrequently, However, during the past 12 months we have encountered three patients over 60 years of age known to have chronic renal failure who were on dialysis for 2 weeks, 3 weeks, and 2 months, respectively. All three patients were hypertensive, requiring between four and five antihypertensive medications. One patient was ventilator dependent in intractable cardiac failure with pulmonary artery systolic pressures ranging from 60 to 70 mm Hg. Standard biplanar arteriography revealed occlusion of the left renal artery with distal reconstitution in two patients and a 99% stenosis of the right renal artery in the remaining patient. The contralateral renal artery was totally occluded in two patients and diffusely stenotic in one. The recipient kidneys measured 8, 10, and n cm in length. Kidney function was assessed by renal scindgraphy and creatinine clearance. Two splenorenal bypasses and one hepatorenal bypass with 6 mm polytetrafluoroethylene graft were performed successfully. After surgery, renal function improved in all patients with two of three patients resuming normal fimction as evidenced by reduction of serum creatinine levels to 0.9 and 1.3 mg/dl. The third patient recovered to have a creatinine level of 3.2 mg/dl. All patients were discharged home within I month with a daily urine output greater than 1500 ml. At discharge, each patient required only two antihypertensive medications to control blood pressure. Duplex scanning 3, 6, and 12 months after surgery confirmed patency of all reconstructions. We conclude that unilateral renal artery revascularization in selected patients who are dialysis dependent can be performed safely and avert the necessity for chronic dialysis. (J VASC SURG 1993; 18: ) Although the efficacy of reconstructive surgery on stenotic renal arteries has been well appreciated for many years, 1'2 most attention has focused on the salutary effect of this surgery on renovascular hypertension. However, more recently the preservation and even retrieval of renal function in patients with occlusive disease of the renal arteries have become increasingly the primary indication for surgical intervention, accounting for 32% to 72% of renal artery reconstructive procedures in several large series, ss Despite this trend, reports of renal artery revascuiarization cite the relatively infrequent performance of these procedures for functional salvage in patients already requiring dialysis. 4'6'7 Moreover, the sparse From the Division of Vascular Surgery, Maimonides Medical Center, Brooklyn. Presented at the Seventh Annual Meeting of the Eastern Vascular Society, Philadelphia, Pa., April 29-May 2, Reprint requests: Enrico Ascer, MD, Director of Vascular Surgery, Maimonides Medical Center, Brooklyn, NY Copyright 1993 by The Society for Vascular Surgery and International Society for Cardiovascular Surgery, North American Chapter /93/$ /6/ literature available provides somewhat conflicting data regarding the role of unilateral versus bilateral revascularization in this group of patients. 6; In this report we present our experience with three patients encountered during the preceding 12 months with chronic renal failure requiring dialysis who subsequently underwent unilateral renal artery revascularization. Each patient became dialysis independent after surgery. We highlight the utility of this procedure in sdected patients, and in addition, review the literature, which revealed the relatively infrequent occurrence of this group of patients and underscores their previously unsuspected potential for renal salvage. CASE REPORTS Case 1. A 61-year-old white woman was admitted to Maimonides Medical Center in mid-october 1992 in congestive failure of 24 hours' duration. Her past medical history was remarkable for multiple recent hospitalizations for congestive heart failure/pulmonary edema, although she denied prior myocardial infarction. Other significant past medical history included chronic, poorly controlled hypertension and chronic renal failure for approximately 5

2 ~OURNALOF VASCULARSURGElkY Volume 18, Number 6 Ascerj Gennaro, and Rogers 1013 Fig. 1. Technetium 99 renal scintigraphy of patient in case 1 demonstrates moderate decreased flow and fimction to right kidney (solidarrow, lowerrightframe) without obstruction and marked reduced flow to left kidney. months. Her medications included five antihypertensive agents. Laboratory studies demonstrated normal electrolytes and blood urea nitrogen/creatinine creatine levels (62/2.5 mg/dl), and urinalysis revealed no proteinuria. The patient's hospital course can be summarized by the development of intractable cardiac failure despite multiple antihypertensive medication regimens ultimately leading to respiratory failure requiring ventilator dependence and tracheostomy. Cardiac catheterization revealed severe stenosis of the mid-right coronary artery and a hypercontrac- tile left ventricle with mild to moderate mitral regurgitation. Her renal function deteriorated further and oliguria developed (< 350 ml urine/day) requiring hemodialysis three times per week. Ultrasound examination of the kidneys demonstrated an 11 cm right kidney and 4 cm left kidney. Technetium 99 nuclear renal scintigraphy demonstrated bilateral poorly functioning kidneys (left much worse than right) without evidence of obstruction of flow to either kidney (Fig. 1). Biplanar aortic and celiac angiography revealed 99% stenosis of the right renal artery

3 1014 Ascer, Gennaro, and Rogers December 1993 Fig. 2. Anteroposterior view of abdominal aorta demonstrates 99% stenosis of proximal right renal artery (solid black arrow) with reconstitution distally (curved black arrow). Left renal artery and kidney are not visualized. and nonvisualization of the left kidney (Fig. 2). Attempts at angioplasty and thrombolytic therapy of the right renal artery were unsuccessful. Renal vein renin assay lateralized to the right kidney. The preoperative blood urea nittogen/creatinine level was 121/5.0 mg/dl. A right renal'artery bypass was performed with 6 mm polytetrafluoroethylene obtaining inflow from the common hepatic artery, which had been assessed by angiography to be without significant atherosclerotic disease. During surgery, there was weakly pulsatile backbleeding from the renal artery, and, after completion of the bypass, there was an immediate diuresis and dramatic reduction in pulmonary artery systolic pressures. The diuresis continued during the first postoperative week, with reduction in the patient's weight by 12 kg, compared with the preoperative value. The endotracheal tube and tracheostomy canula were removed by i week, and the patient was discharged on the tenth postoperative day with blood urea nitrogen/creatinine levels of 13/0.7 mg/dl, requiring only two antihypertensive medications to control blood pressure. Sixmonth follow-up by duplex imaging and radionuclide study demonstrated a patent bypass and functioning right kidney. Case 2. A 69-year-old white woman with past medical history significant for hypertension of many years' duration, coronary artery disease and myocardial infarction, episodes of congestive heart failure, chronic obstructive pulmonary disease, and chronic renal failure not requiring dialysis was admitted for evaluation after routine outpatient laboratory examination revealed rapidly deteriorating renal

4 Volume 18, Number 6 Ascer, Gennaro, and Rogers 1015 Fig. 3. Anteroposterior view demonstrates 99% stenosis of left renal artery (solid black arrow) and diffusely stenotic right renal artery (curved black arrow). function. At the time of admission to the hospital, four antihypertensive medications were required to control her blood pressure and the blood urea nitrogen/creatinine level was 86/6.1 mg/dl. Urinalysis demonstrated no proteinuria. Renal ultrasound examination revealed small kidneys bilaterally, the left kidney measuring 8 cm in longitudinal axis and the right kidney 7 cm. Technetium 99 renal scan demonstrated bilateral poor flow and function (right worse than left). Aortic and renal angiography disclosed a 99% stenosis of the left proximal renal artery with visualization of the kidney and a diffusely stenotic right renal artery (Fig. 3). After angiography, her renal function deteriorated further and she required peritoneal dialysis. The blood urea nitrogen/creatinine level peaked at 111/10.4 mg/dl and she continued to require peritoneal dialysis 3 weeks after angiography because of insignificant improvement in excretory function. A splenorenal artery bypass to the left kidney was performed uneventfully. Backbleeding was present from the left renal artery. Despite a moderate diuresis beginning 24 to 36 hours after surgery, the patient was not extubated until the third postoperative day. On the thirty-fourth postoperative day the patient was discharged home ambulatory, requiring only two antihypertensive medications and with stable renal function (blood urea nitrogen/creatinine level 54/3.6 mg/dl) off dialysis. Ninemonth follow-up by duplex imaging and technetium 99 scanning demonstrated a patent graft and functioning kidney. Case 3. A 73-year-old white woman with past medical history significant for hypertension for more than 30 years and coronary artery bypass grafting was admitted for nausea, vomiting, and shortness of breath. Four antihypertensive medications, including one angiotensin-converting enzyme inhibitor, were required for blood pressure control. Several months earlier the patient had been noted to have diminished but stable renal fianction. However, at the time of admission to the hospital she was in acute kidney failure with a blood urea nitrogen/creatinine level of 180/19.0 mg/dl and oliguria. Urinalysis revealed no proteinuria. After discontinuation of the angiotensin-converting enzyme inhibitor and institution of peritoneal dialysis, the blood urea nitrogen/creatinine level stabilized at 53/6.4 mg/dl. Ultrasonography of the kidneys demonstrated a small right kidney (6 cm) and left kidney measuring 10 cm. Technetium 99 renal scan showed bilateral poorly functioning kidneys (right worse than left). Standard biplanar visceral and aortic angiography revealed proximal occlusion of the left renal artery with reconstitution approximately 2.0 cm from the aorta and nonvisualization of the right renal artery (Fig. 4). The celiac and mesenteric vessels were not significantly diseased. A splenorenal artery bypass to the left kidney, which had pulsatile backbleeding, was performed with resultant immediate intraoperative diuresis. The postoperative course was uncomplicated and she was discharged home on the fifteenth day requiring two antihypertensive medications with markedly improved renal function (blood urea nitrogen/creatinine level 25/1.5 mg/dl).

5 1016 Ascer, Gennaro, and Rogers December 1993 Fig. 4. Delayed aortogram reveals occluded proximal left renal artery with reconstitution distally (curved white arrow). DISCUSSION Since 1934 when Goldblatt et al. 8 elucidated the pathophysiologic mechanism underlying renovascular hypertension, multiple reports have validated the concept that reconstruction of stenotic renal arteries can relieve the hypertensive response resulting from obstructed renal arterial flow? 3,6 However, the concept that surgical revascularization of ischemic kidneys might also preserve or improve renal function, and therefore be indicated in the management of stenotic renal arteries, required approximately 25 years before its realization in the clinical setting. 9 During the succeeding 30 years, continued interest and emphasis in this indication for renal revascularization have generated numerous reports illustrating the beneficial effect on excretory function resulting from improved renal perfusion after bypass. 1 q4 Recent reports from centers with substantial experience indicate that renal artery revascularization to correct impaired kidney function resulting from stenotic or occluded renal arteries constitutes an increasing percentage of all reconstructive procedures.35 The rationale for surgical correction of occlusive disease of the renal arteries causing impaired renal excretory function-the so-called ischemic nephropathy-is derived from demographic observations of the patients with end-stage renal failure. Approximately three quarters of these patients were noted in a 1986 survey to be in the atherosclerotic age

6 Volume 18, Number 6 Ascer~ Gennaro, and Rogers 1017 range (greater than 40 years of age), with a median age of 60 years, is Furthermore, others have noted that atherosclerotic disease of the renal arteries has become a significant cause of renal failure requiring dialysis. 16,17 Another report of those patients with both resistent hypertension and azotemia admitted for hospitalization and evaluation disclosed that almost 50% (10/21) had renal artery atherosclerosis contributing to poor renal function. 18 These data, in conjunction with data from other studies of the natural history ofatherosclerotic renovascular disease treated medically that noted that progressive vascular obstruction frequently leads to deterioration in renal function, 19'2 provide compelling reasons for the aggressive evaluation of these hypertensive patients. In fact, Hansen et al.6 screens all hypertensive patients over 50 years of age who have either newly recognized or recently accelerated deterioration in renal function by renal duplex ultrasonography. Notwithstanding the increasing enthusiasm for surgical revascularization procedures to improve or preserve function in kidneys rendered ischemic from occlusive disease of the renal artery, very few patients who have progressed to become dependent on dialysis undergo salvage procedures. Kaylor et al.7 noted that only 9 (1.1%) out of 813 patients with end-stage renal failure seen for renal-replacement therapy who had atherosclerotic renal artery occlusion were candidates for surgical revascularization. In the report by Hansen et al.,6 within a group of 157 patients with atherosclerotic renovascular disease who were candidates for surgical reconstruction, only 11 patients, or 7%, were on dialysis. The main reason for this is that the majority of patients with end-stage renal failure requiring dialysis have far-advanced parenchymal disease, making any reconstructive procedure a futile technical exercise because reestablishing adequate blood flow to nonfunctioning nephrons will have insignificant impact on renal excretion. The question whether unilateral renal artery revascularization in patients at high risk dependent on dialysis merits discussion. Kaylor et al.7 reported excellent results in nine patients undergoing unilateral renal artery revascularization. All nine patients became dialysis independent after surgery and sustained adequate renal function during their followup. There were no operative deaths and only three minor complications. On the other hand, Hansen et al.6 reported that two of three dialysis-dependent patients undergoing unilateral renal artery revascularization required reinstitution of dialysis after surgery. This undoubtably resulted from the severe degree of bilateral microscopic nephrosclerosis in the absence of significant contralateral renal artery disease. Thus although successful revascularization of the affected renal artery was accomplished, dialysis was not averted because of the preexisting bilateral parenchymal disease. Furthermore, in patients with severe renal disease, unilateral renal revascularizations were found to result in an insignificant increase in estimated glomerular filtration rate compared with patients undergoing bilateral renal artery reconstruction. The implication is that patients with severe renal insufficiency and bilateral renal artery disease will more likely benefit from bilateral revascularization than will patients with unilateral disease undergoing unilateral renal artery reconstruction. This would obviously have special pertinence to patients already on dialysis. Support of these data is provided by their eight patients on dialysis before surgery who subsequently underwent bilateral renal artery revascularization, retrieved renal function after surgery, and averted the necessity for dialysis. However, in another study by Dean et al.,5 four patients undergoing unilateral renal artery revascularization (33%) had a significant improvement in postoperative estimated glomerular filtration rate. They further emphasize that controlling hypertension can have the beneficial effect of preservation of renal function and decreasing cardiovascular morbidity even in the absence of significant improvement of renal excretory function. Undoubtably, patient selection for revascularization plays a pivotal role determining the postoperative result. Rapid deterioration in previously stable renal function or new onset of uncontrollable hypertension heralds potential renovascular disease and should prompt initiation of evaluation. Kaylor et al.7 and Zinman and Libertino 14 cite objective findings that may assist predicting which patients will have a beneficial response to renal artery revascularization. Kidney size greater than 10 cm, evidence of renal perfusion and function by radioisotope scan, extensive collateral blood supply providing perfusion distal to an obstruction, and backbleeding from the distal renal artery during the operation provide supportive evidence of renal viability and potential for salvage after revascularization. The requirement of viable glomeruli on kidney biopsy is controversial. Although some believe the preservation of glomerular structure to be significantly predictive of postoperative return of renal function, 7,14 others cite the focal nature of the glomerular hyalinization process, that makes predictions of postoperative retrieval of function inaccurate. 6 Marked renal insufficiency before surgery defined by serum creatinine level greater than 4.0 to 5.5 mg/dl was found to correlate with

7 1018 Ascer, Gennaro, and Rogers December 1993 poor outcome after surgery, with continued need for dialysis. 4 Finally, patients who have a relatively rapid rate of decline in renal function evidenced by alteration in estimated glomerular filtration rate may benefit the most from revascularization, s The patients in this report conform to the pattern noted in other studies. 5,7 All were aged greater than 60 years and had evidence of concomitant atherosclerotic disease. Acute deterioration in renal function necessitating dialysis prompted evaluation and revealed severe bilateral renovascular disease but essentially unilateral function. Unilateral renal artery revascularization resulted in significant improvement in excretory function such that all three patients did not require dialysis after surgery. In addition, all were discharged with improved blood pressure control taking fewer antihypertensive medications. Because the institution of dialysis for management of kidney failure is an expensive treatment process associated with significant curtailment in life expectancy in patients with atherosclerotic renovascular disease, ~7 we believe unilateral renal artery revascularization in selected patients can be beneficial for not only averting the necessity for dialysis but also its additional salutary effect on control of blood pressure. REFERENCES 1. Stanley JC, Fry WJ. Surgical treatment of renovascular hypertension. Arch Surg 1977; 112: Foster JH, Dean RH, Pinkerston IA, et al. Ten years experience with the surgical management of renovascular hypertension. Ann Surg 1973;177: Novick AC, Ziegelbaum M, Vidt DG, Gifford RW, Pohl MA, Goomastic M. Trends in surgical revascularization for renal artery disease: ten years experience. JAMA 1987;257: Bredenberg CE, Sampson LN, Ray FS, Cormier RA, Heintz PA, Eldrup-Jorgensen J. Changing patterns in surgery for chronic renal artery occlusive diseases. J VAse SURG 1992; 15: Dean RH, Tribble RW, Hansen KJ, O'Neil E, Craven TE, Redding JF. Evolution of renal insufficiency in ischemic nephropathy. Ann Surg 1991;213: Hansen KJ, Starr SM, Sands E, Burkart JM, Plonk GW, Dean RH. Contemporary surgical management of renovascular disease. J VASC SURG 1992;16: Kaylor WM, Novick AC, Ziegelbaum M, Vidt DG. Reversal of end stage renal failure with surgical revascularization in patients with atherosclerotic renal artery occlusion, j Urol 1989;141: Goldblatt H, Lynch l, Hanzel RF, Summerville WD. Studies in experimental hypertension. I: The production of persistent elevation of systemic blood pressure by means of renal ischemia. J Exp Med 1934;59: Morris GC, DeBakey ME, Cooley DA. Surgical treatment of renal failure of renovascular origin, lama 1962;182: Baird Rl, Yen& ER, Firor WB. Anuria due to acute occlusion of the artery to a solitary kidney: successful treatment by operative means. N Engl J Med 1965;272: Smith SP, Hamburger RJ, Donohue JP, Grim CE. Occlusion of the artery to a solitary kidney: restoration of renal function after prolonged anuria. JAMA 1974;230: Schefft P, Novick AC, Stewart BH, Straffon RA. Renal revascularization in patients with total occlusion of the renal artery. J Urol 1980;124: Libertino JA, Zinman L, Breslin DJ, Swinton NW, Legg MA. Renal artery revascularization: restoration of renal function. JAMA 1980;244: Zinman L, Libertino JA. Revascularization of the chronic totally occluded renal artery with restoration of renal function. l Urol 1977;118: North Carolina Kidney Council. Annual report. Raleigh, N.C.: North Carolina Kidney Council, Scoble JE, Maher ER, Hamilton G, Dick R, Sweny P, Moorhead JF. Atherosclerotic renovascular disease causing renal impairment: a case for treatment. Clin Nephrol 1989; 31: Mailloux LU, Bellucci AG, Mossey RT, et al. Predictors of survival in patients undergoing dialysis. Am J Med 1988;84: Ying CY, Tifft CP, Gavras H, Chobanian AV. Renal revascaxlarization in the azotemic hypertensive patient resistant to therapy. N Engl J Med 1984;311: Schreiber MJ, Pohl MA, Novick AC. The natural history of atherosclerotic and fibrous renal artery disease. Urol Clin North Am 1984;11: Dean RH, Kieffer RW, Smith BM, et al. Renovascular hypertension: anatomic and renal function changes during drug therapy. Arch Surg 1981;116: Submitted May 27, 1993; accepted July 16, 1993.