- Email: [email protected]
Unilateral Operation for Bilateral Renovascular Disease
Vol. 111, March Printed in U.S.A.
THE JOURNAL OF UROLOGY
Copyright© 1974 by The Williams & Wilkins Co.
UNILATERAL OPERATION FOR BILATERAL RENOVASCULAR DISEASE RUBEN F. GITTES
AND
AMBROSE P. MCLAUGHLIN, III
From the Division of Urology, University Hospital, University of California, San Diego School of Medicine, San Diego, California
Extensive reviews have been published to document the effectiveness of an operation for patients with renovascular hypertension, selected on the basis of elevation in the concentration of renin in the renal vein of the ischemic kidney. 1 - 4 In unilateral renovascular disease, a prognostic accuracy of more than 90 per cent is claimed if there is an ipsilateral elevation of renin to a ratio of 1.5 or more over the normal side. 5 However, what if renal artery stenosis is bilateral on arteriography? Are we obliged to offer a bilateral operation without the prognostic aid of renal vein renins or split-function tests because the patient lacks a normal side? We report on 8 patients who had bilateral stenosis of the main renal artery but who were selected for a unilateral operation on the basis of renal vein/renal vein and renal vein/peripheral vein renin ratios before and after hydralazine infusion. In each case atherosclerosis was the cause of the vascular defect. Analysis of results in these selected cases strongly suggests that a unilateral operation is successful and, therefore, the procedure of choice in bilateral cases in which renin ratios point to one of the two kidneys as the principal source of the offending renin. METHODS
Selective renal arteriography and aortography were performed in all cases with the Seldinger technique. Renal vein collections before and 15 to 20 minutes after intravenous hydralazine were obtained under the conditions outlined by Mannick, 6 except that the patients received their usual Accepted for publication July 24, 1973. Read at annual meeting of American Urological Association, New York, New York, May 13-17, 1973. 1 Foster, J. H., Rhamy, R. K., Oates, J. A., Klatte, E. C., Burko, H. C. and Michelakis, A. M.: Renovascular hypertension secondary to atherosclerosis. Amer. J. Med., 46: 741, 1969. 'Varaday, P. D. and Maxwell, M. H.: Assessment of statistically significant changes in diastolic blood pressures. J.A.M.A., 221: 365, 1972. 3 Wylie, E. J., Perloff, D. L. and Stoney, R. J.: Autogenous tissue revascularization technics in surgery for renovascular hypertension. Ann. Surg., 170: 416, 1969. 'Kaufman, J. J.: Current status of the diagnosis and treatment of reno-vascular hypertension. Brit. J. Urol., 41: 599, 1969. 5 Michelakis, A. M., Foster, J. H., Liddle, G. W., Rhamy, R. K., Kuchel, 0. and Gordon, R. D.: Measurement of renin in both renal veins. Its use in diagnosis of renovascular hypertension. Arch. Intern. Med., 120: 444, 1967. 'Mannick, J. A., Huvos, A. and Hollander, W. E.: Post-hydralazine renin release in the diagnosis of renovascular hypertension. Ann. Surg., 170: 409, 1969.
medications and diet up to the day before the test. Most patients had severe hypertension, difficult to control even on drugs, and the risk of eliminating therapy was not justified by the known effects of salt restriction and drug maintenance on renin release. 7 • 8 Renin determinations were performed first with a standard bioassay technique 9 and more recently by radioimmunoassay. 10 The techniques for revascularization of the kidney which we used were consistently a saphenous vein bypass graft on the right side and a splenic artery to renal artery anastomosis on the left side. The renal artery was transected distal to the obstruction and anastomosed end-to-end with the bypass vessel. For right side repairs the saphenous graft was first anastomosed end-to-side to the aorta and was passed anterior to the vena cava. On the left side the splenic artery was dissected free from the pancreas, its flow measured with a flowmeter to ascertain its suitability and then divided and dropped retroperitoneally to the level of the renal pedicle. Ample length is usually available for an easy single anastomosis to the transected renal artery. Indeed, we have had occasion to do a successful bilateral bypass with the splenic artery by excising a distal segment to use as a free arterial graft on the right side even as we used the in situ proximal splenic artery to bypass the left side. Splenectomy is not performed and we find excellent collateral supply from the short, gastric arteries supplying the spleen on postoperative angiography. An important technical point is that these particular bypass procedures do not require dissection of the same vascular tissue. Therefore, a saphenous vein bypass on the right side may be done months or years after splenorenal bypass on the left side or vice versa-the dissection of vessels will all be done in previously untouched tissues. This approach minimized the theoretical risk of having to operate 'Warren, D. J. and Ferris, T. F.: Renin secretion in renal hypertension. Lancet, l: 159, 1970. 8 Amsterdam, E. A., Couch, N. T., Christlieb, A. R., Harrison, J. H., Crane, C., Dobrzinsky, S. J. and Bickler, R. B.: Renal vein renin activity in the prognosis of surgery for renovascular hypertension. Amer. J. Med., 47: 860, 1969. 9 Boucher, R., Veyrat, R., De Champlain, J. and Genest, J.: New procedures for measurement of human plasma angiotensin and renin activity levels. Canad. Med. Ass. J., 90: 194, 1964. 10 Haber, E., Koerner, T., Page, L.B., Kliman, B. and Purnode, A.: Application of a radioimmunoassay for angiotensin I to the physiologic measurements of plasma renin activity in normal human subjects. J. Clin. Endocr., 29: 1349, 1969.
292
UNILATERAL OPERATION FOR BILATERAL RENOVASCULAR DISEASE
the untreated side. We have not had to such a second in uur 8 cases treated unilaterally. An electromagnetic blood flowmeter was used in 5 of the 6 revascularization the technical success of the procedure. The flowmeter is more reliable and innocuous than measuring pressure gradients with needles passed the arterial ,val!.
The features of the 8 treated are summarized in table 2.
on excretory to be an tients were cured and have maintained normal blood pressure and serum creatinine for years, respectively. It is remarkable that erosclerosis has led to a knee amputation of the their clear cut plaque at renal artery has shown no clinical sion. Figure 1 shows the an example of these cases. was used in 3 patients 3, 4 and 5) clear-cut lateralization. The patient in case 3 was cured and the patient in 4 was clearly
RESULTS
Patient selection-renin/hydralazine test values. The 8 cases herein were part of a total of 12 patients with bilateral renal artery stenosis and severe hypertension referred to the authors for an operation in the last 5 years. The other 4 cases included: 1) a patient with clear cut lateralization who refused an and died in 6 months with uncontrolled and heart failure, 2) 2 without by renin values whose fibromuscular stenoses extended into the renal artery branches and were treated medically and 3) a with renal small kidneys and bilateral, severe main artery stenoses who was treated with a bilateral Renal failure persisted although the kidneys disease. Thus, 9 of 12 (75 per cent) with bilateral renovascular disease had lateralization renal vein renin determinations. Table 1 shows that a significant ratio of 1.5 or more between the renal vein renins of the guilty and innocent kidneys was present in only 5 of the 9 patients when the samples were taken without hydralazine injection. With hydralazine stimulation the other 4 cases did increase the ratio 1.5 or more. Notable also is the fact that the ratio renm concentration between the renal vein blood from the innocent kidney and the distal vena cava (a peripheral renin) was approximately 1.0 even after hydralazine in all except case 7. In case 7 the ratio of renin concentration rose to 1.6 even as the kidney/kidney ratio rose to 6.6" Case 7 was the only one with unchanged after a unilateral
TABLE
an endarterectomy aorto-iliac shows the Saphenous vem right renal artery was used in 3 cases One patient was cured and one was the third was u1cu11c:eu. The
TABLE 2. Preoperative features of 8 cases of bilatcn,i renal artery stenoses treated with unilateral operatim;
Atherosclerosis of renal arteries Malignant hypertension Age 49-58 yrs" Unilateral renal atrophy " Lateralizing renal vein renins: Before hydralazine infusion . After hydralazine infusion
8
l. Renin values used to recommend unilateral operation in 9 patients with bilateral main renal artery lesioo.s ----·~----
Before Hydralazine
---
K+/K-'
Case No"-Pt.
RL
LL
"--------------
After Hydralazine
IVC
Rt.
Lt.
IVC
K-/IVCt
Operation
I -------"
I-JD 2-RS 3-BB 4-HH 5-TK 6-WD 7-0C 8-GW 9-DM
260 1,410 531 179 2,300 300 128 978 85
510 470
498 2,740 125 168 583 100
250 375 466 170 1.800 224 168 572 225
2.0 3.0 0"9 I.:l 2.4 0.8 1.6 0.8
1.0 1.2 1.1 0.9 1.3 0.6 1.0 1.0 0"5
597 380 3,580 320 718 3,000 2,095
1.029 3.500 12,000 125 109 898 460
636 294 8,500 200 70 807 :J55
1.'i 9.3 3.4 2"6 6.6 3.3 4.5
0"9 1.:1
0.4 0.6 1.6 1.1
u
-----------
* K-rJK---ratio of renal vein renins when K+ is the side with higher concentration.
t K-/IVC-ratio of renal
vein to distal vena cava renin, when K - is the side with lower concentration.
294
GITTES AND MCLAUGHLIN
a simple surgical solution. Figure 3 shows the findings in case 8 as representative of this group.
TABLE
4. Summary of results of unilateral operation in 8
cases of bilateral renal artery stenoses*
DISCUSSION
No. Cases
It is evident that the morbidity and mortality of a simultaneous bilateral renovascular operation should be avoided if 1) the hypertension observed is caused by only 1 of the 2 sides with demonstrated angiographic stenoses and 2) a good result
TABLE
Cured (no treatment) . Improved (less treatment) Unchanged (same treatment) Deaths
4
2 1
* Followup ranged from 6 months to 5 years.
3. Clinical data before and after unilateral operation in 8 cases of bilateral renal artery stenoses Preoperative
Case No.-Pt.-Age-Sex BP 1-JD-53-M 2-RS-53-M 3-BB-49-F 4-HH-65-M
230/140 200/130 180/115 200/130
5-TK-55-M
230-120
6-WD-50-M 7-0C-53-M 8-GW-58-M
185/125 200/110 230/130
Therapy Aldo., apres. Aldo., chlor. Guan., chlor. Aldo., apres., fur. Aldo., apres., prop. Aldo., thiaz., Thiaz. Aldo., thiaz., prop.
Duration of T BP (yrs.)
prop.,
2 15 3 3
thiaz ..
>12
Therapy
120/80 130/80 120/80 160/100
None None None Thiaz.
Followup (yrs.) ---·-5 31/2
Died fourth day of myocardial infarction
res.
150/90 200/100 160/90
l/2
apres.,
Postoperative BP
10
None Res. Apres.
l/2
-·---·-
R.S., 53 y.o.M
RENINS
RK LK IVC K+/KK71VC
1410
470 375 3.0 1.2
FIG. 1. Case 2. Angiogram and drawing demonstrate almost total occlusion of right renal artery along with left renal artery stenosis and obstruction of distal aorta from atherosclerosis. Renal vein renin ratio (K+/K-) of 3 lateralized to right kidney. Patient was cured by right nephrectomy.
UNILATERAL OPERATION FOR BILATERAL RENOVASCULAR DISEASE
295
H.H., 65y.o. M
RENINS AFTER HYDRALAZINE
RK
LK IVC PREOP BP= 200/130 on ALDO-APRES-PROPAN LASIX-DIG-AL P-
1<+11
380 3500 294
9.3 i.3
COUMADIN FIG. 2. Case 4. Angiogram and drawing demonstrate bilateral renal artery stenosis. After hydralazine left Tena! vein renin was 3,500 along with K -/IVC ratio of 1.3 which clearly implicated left kidney. Splenorenal bypass improved long-standing hypertension.
from a unilateral operation will have a good chance to permanently improve the hypertension in a patient with coexisting widespread vascular disease. It has been known for some time that angiographic stenosis is not necessarily physiologically significant and that it is poor practice to perform an operation on x-ray findings alone. The classic investigations of Eyler and associates showed that a third of the significant x-ray lesions of the main renal artery, detected in the process of angiography for peripheral vascular disease, were not associated with hypertension. 11 Therefore, it is reasonable to expect that a large number of the stenoses seen in patients with bilateral lesions will actually not be significant physiologically. Our experience in this 11 Eyler, W. R., Clark, M. D., Garman, J. E., Rian, R. L. and Meininger, D. E.: Angiography of renal areas including a comparative study of renal arterial stenoses in patients with and without hypertension. Radiology, 78: 879, 1962.
short series suggests that in fact 75 per cent patients with bilateral lesions on x-ray will show lateralization to one side upon measurement of the renin level after hydralazine infusion. The prognostic value of these renin measurements in our series proved to be almost as good as that in series witb patients having only unilateral x-ray lesions. if we eliminate the 1 patient who died 4 days postoperatively of a myocardial infarction, we find that 6 of the 7 patients were cured or improved and a prognostic accuracy of 85 per for the lateralization using the renal vein renin concentrations alone. An important measurement in these bilateral cases is the ratio of the renal vein renins from the innocent kidney to the renin concentration in the distal vena cava, that is the K- /IVC ratio in table 1. The blood in the distal vena cava is the peripheral renin and presumably the same as the blood which enters the renal arteries on each side, Therefore, if the renal vein renin concentration is
296
GITTES AND MCLAUGHLIN
RENINS AFTER HYDRALAZINE 3000 RK 898 LK 807 IVC K+/K3.3 I.I tC/IVC FIG. 3. Case 8. Angiogram and drawing demonstrate bilateral renal artery stenosis in patient with long-standing hypertension poorly controlled by medication. Renal vein renin ratios lateralized to right kidney. K-/IVC ratio indicated that left kidney was not contributing to elevated renins. Saphenous vein bypass was performed from aorta to area of post-stenotic dilatation in right renal artery.
the same as the peripheral renin, that is the K-/IVC ratio approximates unity, then it seems likely that that kidney is not adding renin to the circulation and the other kidney is solely responsible for the hypertension even though there are bilateral renovascular lesions on x-ray. It should be cautioned that renin measurements are often far from accurate. Multiple samples are recommended, especially now that the radioimmunoassay requires small volumes of plasma. Our experience has indicated that laboratory variation alone on serial samples is often as high as 20 per cent. This fact tempers any efforts to read significance into ratios less than 1.5 between samples taken sequentially from different veins. We must answer our second requirement for any endorsement of a conservative, unilateral operation on these bilateral cases. Are these patients cured or improved for a relatively long time or are they doomed to return early to an operation for a procedure which skeptics would say should have been done at the same time as the other repair? With followup of 6 months to 5 years we have never had to operate on the other side, nor have we had a late relapse of severe hypertension. Those patients with widespread atherosclerosis have a foreshortened timetable of life expectancy so that these trouble-free followup periods become significant indeed. However, if severe hypertension recurs in
cases treated with vascular bypass we will urge the patient to have repeated angiography and renin ratios. If the previously unoperated side is then the guilty side, it will be comforting to plan an operation in untouched vessels. As pointed out, the use of splenorenal artery bypass on the left side or saphenous bypass on the right side, leaves a virgin field on the opposite side if surgical dissection is necessary. When a kidney is atrophic (cases 1 and 2) and renin ratios point to it as the guilty side, even though there is a significant stenosis of the artery to the good kidney, the urologist should urge a simple nephrectomy via a limited extraperitoneal approach as a low-risk approach likely to succeed. We are convinced that in such cases an expert, quick nephrectomy by a urologist is much more advisable than a premature vascular bypass procedure to a functioning solitary kidney by the most expert of vascular surgeons. The patient with a solitary kidney can then be followed easily with blood pressure readings and serum creatinine levels to detect any significant progression of the atherosclerotic plaque. SUMMARY
Patients treated for bilateral renal artery lesions were reviewed to determine the success rate of a unilateral corrective operation when its perform-
UNILATERAL OPERATION FOR BILATERAL RENOVASCULAR DISEASE
ance is based on renal vein renin concentrations. Measurement of renal vein renins after hydralazine infusion resulted in a ratio of 1.5 or more between the 2 kidneys (K +/K-) in 8 cases which were then treated on the high-renin side (K+) only with aortorenal bypass or nephrectomy. Cure or marked improvement of hypertension 'Nas achieved in 85 per cent of the cases. The 1 patient whose hypertension did not respond had the highest ratio between the unoperated and the distal vena cava (H:- /IVC). All 8
297
patients had atherosclerotic stenoses. With followup of 6 months to 5 years, there was no l.ate relapse of severe hypertension and not been necessary on the other It is clear that a unilateral the physiological information of renal vein renins between and between the innocent kidney and the distd vena cava (K- /IVC) is sufficient to treat renal hypertension successfully even though raphy may show defects bilaterally.
THE JOURNAL OF UROLOGY
Copyright© 1974 by The Williams & Wilkins Co.
UNILATERAL OPERATION FOR BILATERAL RENOVASCULAR DISEASE RUBEN F. GITTES
AND
AMBROSE P. MCLAUGHLIN, III
From the Division of Urology, University Hospital, University of California, San Diego School of Medicine, San Diego, California
Extensive reviews have been published to document the effectiveness of an operation for patients with renovascular hypertension, selected on the basis of elevation in the concentration of renin in the renal vein of the ischemic kidney. 1 - 4 In unilateral renovascular disease, a prognostic accuracy of more than 90 per cent is claimed if there is an ipsilateral elevation of renin to a ratio of 1.5 or more over the normal side. 5 However, what if renal artery stenosis is bilateral on arteriography? Are we obliged to offer a bilateral operation without the prognostic aid of renal vein renins or split-function tests because the patient lacks a normal side? We report on 8 patients who had bilateral stenosis of the main renal artery but who were selected for a unilateral operation on the basis of renal vein/renal vein and renal vein/peripheral vein renin ratios before and after hydralazine infusion. In each case atherosclerosis was the cause of the vascular defect. Analysis of results in these selected cases strongly suggests that a unilateral operation is successful and, therefore, the procedure of choice in bilateral cases in which renin ratios point to one of the two kidneys as the principal source of the offending renin. METHODS
Selective renal arteriography and aortography were performed in all cases with the Seldinger technique. Renal vein collections before and 15 to 20 minutes after intravenous hydralazine were obtained under the conditions outlined by Mannick, 6 except that the patients received their usual Accepted for publication July 24, 1973. Read at annual meeting of American Urological Association, New York, New York, May 13-17, 1973. 1 Foster, J. H., Rhamy, R. K., Oates, J. A., Klatte, E. C., Burko, H. C. and Michelakis, A. M.: Renovascular hypertension secondary to atherosclerosis. Amer. J. Med., 46: 741, 1969. 'Varaday, P. D. and Maxwell, M. H.: Assessment of statistically significant changes in diastolic blood pressures. J.A.M.A., 221: 365, 1972. 3 Wylie, E. J., Perloff, D. L. and Stoney, R. J.: Autogenous tissue revascularization technics in surgery for renovascular hypertension. Ann. Surg., 170: 416, 1969. 'Kaufman, J. J.: Current status of the diagnosis and treatment of reno-vascular hypertension. Brit. J. Urol., 41: 599, 1969. 5 Michelakis, A. M., Foster, J. H., Liddle, G. W., Rhamy, R. K., Kuchel, 0. and Gordon, R. D.: Measurement of renin in both renal veins. Its use in diagnosis of renovascular hypertension. Arch. Intern. Med., 120: 444, 1967. 'Mannick, J. A., Huvos, A. and Hollander, W. E.: Post-hydralazine renin release in the diagnosis of renovascular hypertension. Ann. Surg., 170: 409, 1969.
medications and diet up to the day before the test. Most patients had severe hypertension, difficult to control even on drugs, and the risk of eliminating therapy was not justified by the known effects of salt restriction and drug maintenance on renin release. 7 • 8 Renin determinations were performed first with a standard bioassay technique 9 and more recently by radioimmunoassay. 10 The techniques for revascularization of the kidney which we used were consistently a saphenous vein bypass graft on the right side and a splenic artery to renal artery anastomosis on the left side. The renal artery was transected distal to the obstruction and anastomosed end-to-end with the bypass vessel. For right side repairs the saphenous graft was first anastomosed end-to-side to the aorta and was passed anterior to the vena cava. On the left side the splenic artery was dissected free from the pancreas, its flow measured with a flowmeter to ascertain its suitability and then divided and dropped retroperitoneally to the level of the renal pedicle. Ample length is usually available for an easy single anastomosis to the transected renal artery. Indeed, we have had occasion to do a successful bilateral bypass with the splenic artery by excising a distal segment to use as a free arterial graft on the right side even as we used the in situ proximal splenic artery to bypass the left side. Splenectomy is not performed and we find excellent collateral supply from the short, gastric arteries supplying the spleen on postoperative angiography. An important technical point is that these particular bypass procedures do not require dissection of the same vascular tissue. Therefore, a saphenous vein bypass on the right side may be done months or years after splenorenal bypass on the left side or vice versa-the dissection of vessels will all be done in previously untouched tissues. This approach minimized the theoretical risk of having to operate 'Warren, D. J. and Ferris, T. F.: Renin secretion in renal hypertension. Lancet, l: 159, 1970. 8 Amsterdam, E. A., Couch, N. T., Christlieb, A. R., Harrison, J. H., Crane, C., Dobrzinsky, S. J. and Bickler, R. B.: Renal vein renin activity in the prognosis of surgery for renovascular hypertension. Amer. J. Med., 47: 860, 1969. 9 Boucher, R., Veyrat, R., De Champlain, J. and Genest, J.: New procedures for measurement of human plasma angiotensin and renin activity levels. Canad. Med. Ass. J., 90: 194, 1964. 10 Haber, E., Koerner, T., Page, L.B., Kliman, B. and Purnode, A.: Application of a radioimmunoassay for angiotensin I to the physiologic measurements of plasma renin activity in normal human subjects. J. Clin. Endocr., 29: 1349, 1969.
292
UNILATERAL OPERATION FOR BILATERAL RENOVASCULAR DISEASE
the untreated side. We have not had to such a second in uur 8 cases treated unilaterally. An electromagnetic blood flowmeter was used in 5 of the 6 revascularization the technical success of the procedure. The flowmeter is more reliable and innocuous than measuring pressure gradients with needles passed the arterial ,val!.
The features of the 8 treated are summarized in table 2.
on excretory to be an tients were cured and have maintained normal blood pressure and serum creatinine for years, respectively. It is remarkable that erosclerosis has led to a knee amputation of the their clear cut plaque at renal artery has shown no clinical sion. Figure 1 shows the an example of these cases. was used in 3 patients 3, 4 and 5) clear-cut lateralization. The patient in case 3 was cured and the patient in 4 was clearly
RESULTS
Patient selection-renin/hydralazine test values. The 8 cases herein were part of a total of 12 patients with bilateral renal artery stenosis and severe hypertension referred to the authors for an operation in the last 5 years. The other 4 cases included: 1) a patient with clear cut lateralization who refused an and died in 6 months with uncontrolled and heart failure, 2) 2 without by renin values whose fibromuscular stenoses extended into the renal artery branches and were treated medically and 3) a with renal small kidneys and bilateral, severe main artery stenoses who was treated with a bilateral Renal failure persisted although the kidneys disease. Thus, 9 of 12 (75 per cent) with bilateral renovascular disease had lateralization renal vein renin determinations. Table 1 shows that a significant ratio of 1.5 or more between the renal vein renins of the guilty and innocent kidneys was present in only 5 of the 9 patients when the samples were taken without hydralazine injection. With hydralazine stimulation the other 4 cases did increase the ratio 1.5 or more. Notable also is the fact that the ratio renm concentration between the renal vein blood from the innocent kidney and the distal vena cava (a peripheral renin) was approximately 1.0 even after hydralazine in all except case 7. In case 7 the ratio of renin concentration rose to 1.6 even as the kidney/kidney ratio rose to 6.6" Case 7 was the only one with unchanged after a unilateral
TABLE
an endarterectomy aorto-iliac shows the Saphenous vem right renal artery was used in 3 cases One patient was cured and one was the third was u1cu11c:eu. The
TABLE 2. Preoperative features of 8 cases of bilatcn,i renal artery stenoses treated with unilateral operatim;
Atherosclerosis of renal arteries Malignant hypertension Age 49-58 yrs" Unilateral renal atrophy " Lateralizing renal vein renins: Before hydralazine infusion . After hydralazine infusion
8
l. Renin values used to recommend unilateral operation in 9 patients with bilateral main renal artery lesioo.s ----·~----
Before Hydralazine
---
K+/K-'
Case No"-Pt.
RL
LL
"--------------
After Hydralazine
IVC
Rt.
Lt.
IVC
K-/IVCt
Operation
I -------"
I-JD 2-RS 3-BB 4-HH 5-TK 6-WD 7-0C 8-GW 9-DM
260 1,410 531 179 2,300 300 128 978 85
510 470
498 2,740 125 168 583 100
250 375 466 170 1.800 224 168 572 225
2.0 3.0 0"9 I.:l 2.4 0.8 1.6 0.8
1.0 1.2 1.1 0.9 1.3 0.6 1.0 1.0 0"5
597 380 3,580 320 718 3,000 2,095
1.029 3.500 12,000 125 109 898 460
636 294 8,500 200 70 807 :J55
1.'i 9.3 3.4 2"6 6.6 3.3 4.5
0"9 1.:1
0.4 0.6 1.6 1.1
u
-----------
* K-rJK---ratio of renal vein renins when K+ is the side with higher concentration.
t K-/IVC-ratio of renal
vein to distal vena cava renin, when K - is the side with lower concentration.
294
GITTES AND MCLAUGHLIN
a simple surgical solution. Figure 3 shows the findings in case 8 as representative of this group.
TABLE
4. Summary of results of unilateral operation in 8
cases of bilateral renal artery stenoses*
DISCUSSION
No. Cases
It is evident that the morbidity and mortality of a simultaneous bilateral renovascular operation should be avoided if 1) the hypertension observed is caused by only 1 of the 2 sides with demonstrated angiographic stenoses and 2) a good result
TABLE
Cured (no treatment) . Improved (less treatment) Unchanged (same treatment) Deaths
4
2 1
* Followup ranged from 6 months to 5 years.
3. Clinical data before and after unilateral operation in 8 cases of bilateral renal artery stenoses Preoperative
Case No.-Pt.-Age-Sex BP 1-JD-53-M 2-RS-53-M 3-BB-49-F 4-HH-65-M
230/140 200/130 180/115 200/130
5-TK-55-M
230-120
6-WD-50-M 7-0C-53-M 8-GW-58-M
185/125 200/110 230/130
Therapy Aldo., apres. Aldo., chlor. Guan., chlor. Aldo., apres., fur. Aldo., apres., prop. Aldo., thiaz., Thiaz. Aldo., thiaz., prop.
Duration of T BP (yrs.)
prop.,
2 15 3 3
thiaz ..
>12
Therapy
120/80 130/80 120/80 160/100
None None None Thiaz.
Followup (yrs.) ---·-5 31/2
Died fourth day of myocardial infarction
res.
150/90 200/100 160/90
l/2
apres.,
Postoperative BP
10
None Res. Apres.
l/2
-·---·-
R.S., 53 y.o.M
RENINS
RK LK IVC K+/KK71VC
1410
470 375 3.0 1.2
FIG. 1. Case 2. Angiogram and drawing demonstrate almost total occlusion of right renal artery along with left renal artery stenosis and obstruction of distal aorta from atherosclerosis. Renal vein renin ratio (K+/K-) of 3 lateralized to right kidney. Patient was cured by right nephrectomy.
UNILATERAL OPERATION FOR BILATERAL RENOVASCULAR DISEASE
295
H.H., 65y.o. M
RENINS AFTER HYDRALAZINE
RK
LK IVC PREOP BP= 200/130 on ALDO-APRES-PROPAN LASIX-DIG-AL P-
1<+11
380 3500 294
9.3 i.3
COUMADIN FIG. 2. Case 4. Angiogram and drawing demonstrate bilateral renal artery stenosis. After hydralazine left Tena! vein renin was 3,500 along with K -/IVC ratio of 1.3 which clearly implicated left kidney. Splenorenal bypass improved long-standing hypertension.
from a unilateral operation will have a good chance to permanently improve the hypertension in a patient with coexisting widespread vascular disease. It has been known for some time that angiographic stenosis is not necessarily physiologically significant and that it is poor practice to perform an operation on x-ray findings alone. The classic investigations of Eyler and associates showed that a third of the significant x-ray lesions of the main renal artery, detected in the process of angiography for peripheral vascular disease, were not associated with hypertension. 11 Therefore, it is reasonable to expect that a large number of the stenoses seen in patients with bilateral lesions will actually not be significant physiologically. Our experience in this 11 Eyler, W. R., Clark, M. D., Garman, J. E., Rian, R. L. and Meininger, D. E.: Angiography of renal areas including a comparative study of renal arterial stenoses in patients with and without hypertension. Radiology, 78: 879, 1962.
short series suggests that in fact 75 per cent patients with bilateral lesions on x-ray will show lateralization to one side upon measurement of the renin level after hydralazine infusion. The prognostic value of these renin measurements in our series proved to be almost as good as that in series witb patients having only unilateral x-ray lesions. if we eliminate the 1 patient who died 4 days postoperatively of a myocardial infarction, we find that 6 of the 7 patients were cured or improved and a prognostic accuracy of 85 per for the lateralization using the renal vein renin concentrations alone. An important measurement in these bilateral cases is the ratio of the renal vein renins from the innocent kidney to the renin concentration in the distal vena cava, that is the K- /IVC ratio in table 1. The blood in the distal vena cava is the peripheral renin and presumably the same as the blood which enters the renal arteries on each side, Therefore, if the renal vein renin concentration is
296
GITTES AND MCLAUGHLIN
RENINS AFTER HYDRALAZINE 3000 RK 898 LK 807 IVC K+/K3.3 I.I tC/IVC FIG. 3. Case 8. Angiogram and drawing demonstrate bilateral renal artery stenosis in patient with long-standing hypertension poorly controlled by medication. Renal vein renin ratios lateralized to right kidney. K-/IVC ratio indicated that left kidney was not contributing to elevated renins. Saphenous vein bypass was performed from aorta to area of post-stenotic dilatation in right renal artery.
the same as the peripheral renin, that is the K-/IVC ratio approximates unity, then it seems likely that that kidney is not adding renin to the circulation and the other kidney is solely responsible for the hypertension even though there are bilateral renovascular lesions on x-ray. It should be cautioned that renin measurements are often far from accurate. Multiple samples are recommended, especially now that the radioimmunoassay requires small volumes of plasma. Our experience has indicated that laboratory variation alone on serial samples is often as high as 20 per cent. This fact tempers any efforts to read significance into ratios less than 1.5 between samples taken sequentially from different veins. We must answer our second requirement for any endorsement of a conservative, unilateral operation on these bilateral cases. Are these patients cured or improved for a relatively long time or are they doomed to return early to an operation for a procedure which skeptics would say should have been done at the same time as the other repair? With followup of 6 months to 5 years we have never had to operate on the other side, nor have we had a late relapse of severe hypertension. Those patients with widespread atherosclerosis have a foreshortened timetable of life expectancy so that these trouble-free followup periods become significant indeed. However, if severe hypertension recurs in
cases treated with vascular bypass we will urge the patient to have repeated angiography and renin ratios. If the previously unoperated side is then the guilty side, it will be comforting to plan an operation in untouched vessels. As pointed out, the use of splenorenal artery bypass on the left side or saphenous bypass on the right side, leaves a virgin field on the opposite side if surgical dissection is necessary. When a kidney is atrophic (cases 1 and 2) and renin ratios point to it as the guilty side, even though there is a significant stenosis of the artery to the good kidney, the urologist should urge a simple nephrectomy via a limited extraperitoneal approach as a low-risk approach likely to succeed. We are convinced that in such cases an expert, quick nephrectomy by a urologist is much more advisable than a premature vascular bypass procedure to a functioning solitary kidney by the most expert of vascular surgeons. The patient with a solitary kidney can then be followed easily with blood pressure readings and serum creatinine levels to detect any significant progression of the atherosclerotic plaque. SUMMARY
Patients treated for bilateral renal artery lesions were reviewed to determine the success rate of a unilateral corrective operation when its perform-
UNILATERAL OPERATION FOR BILATERAL RENOVASCULAR DISEASE
ance is based on renal vein renin concentrations. Measurement of renal vein renins after hydralazine infusion resulted in a ratio of 1.5 or more between the 2 kidneys (K +/K-) in 8 cases which were then treated on the high-renin side (K+) only with aortorenal bypass or nephrectomy. Cure or marked improvement of hypertension 'Nas achieved in 85 per cent of the cases. The 1 patient whose hypertension did not respond had the highest ratio between the unoperated and the distal vena cava (H:- /IVC). All 8
297
patients had atherosclerotic stenoses. With followup of 6 months to 5 years, there was no l.ate relapse of severe hypertension and not been necessary on the other It is clear that a unilateral the physiological information of renal vein renins between and between the innocent kidney and the distd vena cava (K- /IVC) is sufficient to treat renal hypertension successfully even though raphy may show defects bilaterally.