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Superior Mesenterorenal Bypass for Renal Revascularization with Infrarenal Aortic Occlusion
0022-534 7/85/1332-0188$02.00/0 Vol. 133, February
THE JOURNAL OF UROLOGY
Copyright© 1985 by The Williams & Wilkins Co.
Printed in U.S.A.
SUPERIOR MESENTERORENAL BYPASS FOR RENAL REVASCULARIZATION WITH INFRARENAL AORTIC OCCLUSION RAJA B. KHAULI, ANDREW C. NOVICK,* GEORGE V. COSERIU, EDWIN G. BEVEN NORMAN R. HERTZER
AND
From the Departments of Urology and Vascular Surgery, Cleveland Clinic Foundation, Cleveland, Ohio
ABSTRACT
The technique of renal revascularization using a saphenous vein bypass graft from the superior mesenteric artery is described. This operation has been performed for the correction of renal artery stenosis in 4 patients with atherosclerotic aortic occlusion. When the requisite conditions are present, mesenterorenal bypass offers a safe and effective method of renal revascularization, and is preferable to aortic replacement in selected patients. Renal revascularization is an accepted form of therapy for patients with hypertension and/or azotemia caused by stenotic renovascular disease. Although aortorenal bypass is the preferred method of vascular reconstruction, this operation may be hazardous in patients with severe aortic atherosclerosis or a prior operation on the abdominal aorta. In such cases alternate techniques are available that allow safer and more effective revascularization. 1 ' 2 The most widely applicable methods are splenorenal3 and hepatorenal4 bypasses for left and right renal revascularizations, respectively, and ileorenal bypass to repair either kidney. 5 While these approaches have been suitable for many patients they cannot be used when blood flow through the celiac and iliac arteries is diminished owing to atherosclerotic occlusive disease. In such cases a widely patent superior :mesenteric artery, when present, can be used to perform a visceral-renal arterial bypass in selected patients who otherwise do not require more extensive aortic replacement.
rarily. End-to-end anastomosis of the vein graft to the left renal artery then is done with interrupted 6-zero vascular sutures (fig. 1). During revascularization of the right kidney the ascending colon and duodenum are reflected medially to gain exposure of the aorta and right renal artery. The ascending colon and small bowel then are rotated back to their normal position and the superior mesenteric artery is palpated where it crosses the third portion of the duodenum. The superior mesenteric artery is mobilized and isolated in this location for a distance of 3 to 4 cm. A saphenous vein graft is sutured end-to-side to this portion of the superior mesenteric artery and the graft then is passed through a tunnel in the root of the small bowel mesentery, following a gentle curve as it crosses the third portion of the duodenum to enter the right retroperitoneum. End-to-end anastomosis of the graft to the right renal artery is performed to complete the operation (fig. 2).
OPERATIVE TECHNIQUE
CLINICAL MATERIAL AND RESULTS
To perform mesenterorenal bypass the abdomen is entered through a midline incision. During revascularization of the left kidney, the descending colon and splenic flexure are reflected medially and a plane of dissection is developed between the pancreas and Gerota's fascia. Exposure of the suprarenal aorta is obtained by gentle retraction of the pancreas and first portion of jejunum cephalad, while the mesocolon is reflected medially. If necessary, additional exposure may be obtained by mobilization and evisceration of the right colon and small bowel, as is done commonly for retroperitoneal lymphadenectomy. The superior mesenteric artery can be palpated readily at its origin from the aorta approximately 1 to 2 cm. above the level of the renal arteries. This vessel lies against the neck of the pancreas as it courses between the neck and the uncinate process. The artery then crosses the third part of the duodenum to enter the large bowel mesentery, where it lies posterior and to the left of the superior mesenteric vein. The superior mesenteric artery is mobilized for a distance of 2 to 3 cm. beyond its origin, where it is most accessible and without branches. The left renal artery then is exposed and isolated similarly. The patient receives systemic heparinization with 5,000 units intravenous heparin solution. A reversed segment of saphenous vein is anastomosed end-to-side to the lateral aspect of the superior mesenteric artery with interrupted 6-zero vascular sutures. After completion of this anastomosis, which generally takes 15 to 20 minutes, blood flow through the superior mesenteric artery is restored immediately and the saphenous vein graft is occluded tempo-
From December 1974 to May 1983, 4 patients with atherosclerotic renal artery disease and infrarenal aortic occlusion underwent a superior mesenterorenal saphenous vein bypass operation. The clinical characteristics of these patients and their outcome are detailed in the table. Our first patient to undergo this procedure (S. V.) has been reported on previously. 6 Renal revascularization was indicated for severe associated hypertension in all 4 patients and preservation ofrenal function comprised an additional indication for operative intervention in 3. All patients had mild buttock and/or lower extremity claudication that was stable with conservative treatment. All patients underwent preoperative aortography, including anteroposterior and lateral views. The lateral views demonstrated significant stenosis or occlusion of the celiac artery in all patients, which precluded a splenorenal or hepatorenal bypass (fig. 1, B). However, the superior mesenteric artery was widely patent, which allowed for mesenterorenal bypass in these patients. Immediate postoperative complications consisted of left pneumothorax and· atelectasis in 1 patient, which resolved completely with appropriate treatment. Patency of the reconstructed renal artery has been documented in all patients with conventional or digital subtraction angiography. The postoperative blood pressure was normal in all patients, with 2 requiring low dose antihypertensive medication. All 4 patients are alive 12 to 108 months postoperatively and the level of renal function remains stable or improved. DISCUSSION
Accepted for publication September 7, 1984. * Requests for reprints: Department of Urology, Cleveland Clinic Foundation, 9500 Euclid Ave., Cleveland, Ohio 44106.
An important measure toward limiting surgical mortality after renal revascularization in high risk patients with athero188
SUFERIOR lvtESENTERORENAL BYPASS FOR RENAL RE•/ASCULARIZATION
189
Fm. 1. Patient H. L. A, aortography demonstrates total occlusion of infrarenal aorta and bilateral high grade renal artery stenosis. B, lateral aortogram shows marked stenosis at origin of celiac artery (arrow), while superior mesenteric artery just below is widely patent. C, later film of abdomen shows large marginal artery of Drumm.ond, which fills from superior mesenteric artery. D, after left superior mesenterorenal saphenous vein bypass, digital subtraction angiography reveals patent graft (arrow).
FIG. 2. Patient S. V. A, transbrachial aortogram shows total occlusion of both renal arteries and abdominal aorta below enlarged superior mesenteric artery. Reprinted with permission. 6 B, sketch illustrates right superior mesenterorenal saphenous vein bypass. C, followup aortography 7 years postoperatively shows continued patent right superior mesenterorenal graft.
sclerosis has been the use of techniques that obviate an operation on a badly diseased abdominal aorta. 7 The most frequent alternatives to aortorenal revascularization have been splenorenal, hepatorenal and ileorenal bypasses. 1- 5 These methods are attractive because of their relative simplicity and the fact that they do not jeopardize the sole blood supply to an organ or region. The liver and spleen receive additional vascular supply to that derived from the hepatic and splenic arteries,
respectively. When there is good flow through the diseased aorta and healthy iliac vessels, placement of an ileorenal graft does not interfere with vascularization of the lower extremity owing to the wide caliber of the common iliac artery. The superior mesenteric artery is a more critical vessel, since it provides the sole blood supply to a large portion of the bowel. Nevertheless, the intestines may be protected from ischemia by an abundant collateral circulation. A collateral pathway
190
KHAULI AND ASSOCIATES
Patient characteristics and results following superior mesenterorenal bypass Pt.-Age-Sex SV-58-M LD-63-M
JK-53-M HL-57-M
Aortic Findings lnfrarenal aortic occlusion, bilat. renal artery occlusion Infrarenal aortic occlusion, rt. renal artery occlusion, It. renal artery stenosis Infrarenal aortic occlusion, normal rt. renal artery, It. renal artery stenosis lnfrarenal aortic occlusion, bilat. renal artery stenosis
Serum Creatinine (mg./dl.)
Blood Pressure (mm.Hg)
Operation
Followup (mos.)
Preop.
Postop.
Preop.
Postop.
4.4
2.1
240/140
130/80
Superior mesenteric artery, rt. renal
108
1.2
0.8
210/110
150/85
Superior mesenteric artery, It. renal
65
1.4
1.2
180/120
140/80
Superior mesenteric artery, It. renal
26
1.6
1.2
240/130
140/90
Superior mesenteric artery, It. renal
12
from the celiac axis is obtained via the superior pancreaticoduodenal artery, which communicates with the first branch of the superior mesenteric artery, namely the inferior pancreaticoduodenal artery. Collateral blood supply from the inferior mesenteric artery is provided by the arch of Riolan, which connects with the left and middle colic arteries. The inferior mesenteric artery may, in turn, receive collateral flow from the internal iliac artery via branches from the superior and inferior hemorrhoidal arteries. It has been shown that the bowel can tolerate a significant reduction in blood flow without damage due to this collateral circulation. 8 Our results with superior mesenterorenal bypass in patients with infrarenal aortic occlusion have been satisfactory. Intestinal ischemia has not resulted from this approach, and all 4 patients remain alive with normal blood pressure and stable renal function. In patients with infrarenal aortic occlusion the superior mesenteric artery generally is enlarged, since it supplies collateral vessels to areas vascularized ordinarily by the infrarenal aorta, that is the large bowel, pelvis and lower extremities (fig. 1, C). Use of such an enlarged superior mesenteric artery with improved flow technically facilitates performance of a mesenterorenal bypass and has been well tolerated to date. We have been reluctant to use this approach in patients with a normal-sized superior mesenteric artery and cannot comment on its efficacy in this setting. In summary, the superior mesenterorenal saphenous vein bypass technique has limited and specific indications as a method of renal revascularization. We recommend its use in patients with a surgically difficult aorta in whom a widely patent enlarged superior mesenteric artery is present and when a bypass to the kidney from the celiac or iliac arteries is not possible. One available option in such cases is to perform simultaneous aortic replacement and renal vascularization. However, this approach has been associated with high mortality rates of 5 to 30 per cent. 2 ' 9 - 12 In the absence of a fixed indication to replace the aorta, such as severe ciaudication or an enlarged aneurysm, mesenterorenal bypass allows for a safer and more effective renovascular reconstruction. REFERENCES
1. Novick, A. C., Banowsky, L. H. W., Stewart, B. H. and Straffon,
R. A.: Renal revascularization in patients with severe atherosclerosis of the abdominal aorta or a previous operation on the abdominal aorta. Surg., Gynec. & Obst., 144: 211, 1977. 2. Libertino, J. A. and Selman, F. J., Jr.: Alternatives to aortorenal revascularization. J. Cardiovasc. Surg., 23: 318, 1982. 3. Novick, A. C., Banowsky, L. H. W., Stewart, B. H. and Straffon, R. A.: Splenorenal bypass in the treatment of stenosis of the
renal artery. Surg., Gynec. & Obst., 144: 891, 1977. 4. Chibaro, E. A., Libertino, J. A. and Novick, A. C.: Use of the hepatic circulation for renal revascularization. Ann. Surg., 199: 406, 1984. 5. Novick, A. C. and Banowsky, L. H.: Iliorenal saphenous vein bypass: an alternative for renal revascularization in patients with a surgically difficult aorta. J. Urol., 122: 243, 1979. 6. Hertzer, N. R., Montie, J. E., Hall, P. M. and Banowsky, L. H.: Revascularization of the kidney after occlusion of the aorta and both renal arteries. Surgery, 79: 52, 1976. 7. Novick, A. C., Straffon, R. A., Stewart, B. H., Gifford, R. W. and Vidt, D. G.: Diminished operative morbidity and mortality in renal revascularization. J.A.M.A., 246: 749, 1981. 8. Boley, S. J. and Brandt, L. J.: The pathophysiology of mesenteric blood flow and nonocclusive mesenteric ischemia. In: Surgery of the Aorta and its Body Branches. Edited by J. J. Bergan and J. S. T. Yao. New York: Grune & Stratton, p. 453, 1979. 9. Gomes, M. M. and Bernatz, P. E\-Aorto-iliac occlusive disease. Extension cephalad to origin of renal arteries, with surgical considerations and results. Arch. Surg., 101: 161, 1970. 10. Brewster, D. C., Buth, J., Darling, R. C. and Austen, W. G.: Combined aortic and renal artery reconstruction. Amer. J. Surg., 131: 457, 1976. 11. Shahian, D. M., Najafi, H., Javid, H., Hunter, J. A., Goldin, M. D. and Monson, D. 0.: Simultaneous aortic and renal artery reconstruction. Arch. Surg., 115: 1491, 1980. 12. Foster, J. H., Dean, R.H., Pinkerton, J. A. and Rhamy, R. K.: Ten years experience with the surgical management of renovascular hypertension. Ann. Surg., 177: 755, 1973.
EDITORIAL COMMENT Alternatives to aortorenal saphenous vein bypass grafts for renal revascularization have now become established techniques to revascularize ischemic renal parenchyma safely in patients with hazardous aortic pathological conditions and celiac occlusion. The superior mesenteric artery frequently is the only patent visceral artery available for a bypass source in the patient with diffuse atherosclerosis and compromised renal blood flow. This technique was described first by the authors (reference 6 in article) in 1976 as a single· case report and presently is updated, with 3 additional cases and a long followup on the original case to demonstrate the safety and the stability of the procedure. The authors emphasize the absence of intestinal ischemia or other serious complications compared to the option of aortic replacement with its attendant high mortality rate. This procedure lends itself more readily to left renal artery revascularization but can be used for the right renal artery as well, as illustrated by the first case. The authors rightly note the need for a good, widely patent length of superior mesenteric artery before considering it as a source of bypass and are reluctant to use this approach in patients with a normal size superior mesenteric artery. The technique and results of the procedure emphasize its potential in this uncommon but desperate situation. L.M.Z.
THE JOURNAL OF UROLOGY
Copyright© 1985 by The Williams & Wilkins Co.
Printed in U.S.A.
SUPERIOR MESENTERORENAL BYPASS FOR RENAL REVASCULARIZATION WITH INFRARENAL AORTIC OCCLUSION RAJA B. KHAULI, ANDREW C. NOVICK,* GEORGE V. COSERIU, EDWIN G. BEVEN NORMAN R. HERTZER
AND
From the Departments of Urology and Vascular Surgery, Cleveland Clinic Foundation, Cleveland, Ohio
ABSTRACT
The technique of renal revascularization using a saphenous vein bypass graft from the superior mesenteric artery is described. This operation has been performed for the correction of renal artery stenosis in 4 patients with atherosclerotic aortic occlusion. When the requisite conditions are present, mesenterorenal bypass offers a safe and effective method of renal revascularization, and is preferable to aortic replacement in selected patients. Renal revascularization is an accepted form of therapy for patients with hypertension and/or azotemia caused by stenotic renovascular disease. Although aortorenal bypass is the preferred method of vascular reconstruction, this operation may be hazardous in patients with severe aortic atherosclerosis or a prior operation on the abdominal aorta. In such cases alternate techniques are available that allow safer and more effective revascularization. 1 ' 2 The most widely applicable methods are splenorenal3 and hepatorenal4 bypasses for left and right renal revascularizations, respectively, and ileorenal bypass to repair either kidney. 5 While these approaches have been suitable for many patients they cannot be used when blood flow through the celiac and iliac arteries is diminished owing to atherosclerotic occlusive disease. In such cases a widely patent superior :mesenteric artery, when present, can be used to perform a visceral-renal arterial bypass in selected patients who otherwise do not require more extensive aortic replacement.
rarily. End-to-end anastomosis of the vein graft to the left renal artery then is done with interrupted 6-zero vascular sutures (fig. 1). During revascularization of the right kidney the ascending colon and duodenum are reflected medially to gain exposure of the aorta and right renal artery. The ascending colon and small bowel then are rotated back to their normal position and the superior mesenteric artery is palpated where it crosses the third portion of the duodenum. The superior mesenteric artery is mobilized and isolated in this location for a distance of 3 to 4 cm. A saphenous vein graft is sutured end-to-side to this portion of the superior mesenteric artery and the graft then is passed through a tunnel in the root of the small bowel mesentery, following a gentle curve as it crosses the third portion of the duodenum to enter the right retroperitoneum. End-to-end anastomosis of the graft to the right renal artery is performed to complete the operation (fig. 2).
OPERATIVE TECHNIQUE
CLINICAL MATERIAL AND RESULTS
To perform mesenterorenal bypass the abdomen is entered through a midline incision. During revascularization of the left kidney, the descending colon and splenic flexure are reflected medially and a plane of dissection is developed between the pancreas and Gerota's fascia. Exposure of the suprarenal aorta is obtained by gentle retraction of the pancreas and first portion of jejunum cephalad, while the mesocolon is reflected medially. If necessary, additional exposure may be obtained by mobilization and evisceration of the right colon and small bowel, as is done commonly for retroperitoneal lymphadenectomy. The superior mesenteric artery can be palpated readily at its origin from the aorta approximately 1 to 2 cm. above the level of the renal arteries. This vessel lies against the neck of the pancreas as it courses between the neck and the uncinate process. The artery then crosses the third part of the duodenum to enter the large bowel mesentery, where it lies posterior and to the left of the superior mesenteric vein. The superior mesenteric artery is mobilized for a distance of 2 to 3 cm. beyond its origin, where it is most accessible and without branches. The left renal artery then is exposed and isolated similarly. The patient receives systemic heparinization with 5,000 units intravenous heparin solution. A reversed segment of saphenous vein is anastomosed end-to-side to the lateral aspect of the superior mesenteric artery with interrupted 6-zero vascular sutures. After completion of this anastomosis, which generally takes 15 to 20 minutes, blood flow through the superior mesenteric artery is restored immediately and the saphenous vein graft is occluded tempo-
From December 1974 to May 1983, 4 patients with atherosclerotic renal artery disease and infrarenal aortic occlusion underwent a superior mesenterorenal saphenous vein bypass operation. The clinical characteristics of these patients and their outcome are detailed in the table. Our first patient to undergo this procedure (S. V.) has been reported on previously. 6 Renal revascularization was indicated for severe associated hypertension in all 4 patients and preservation ofrenal function comprised an additional indication for operative intervention in 3. All patients had mild buttock and/or lower extremity claudication that was stable with conservative treatment. All patients underwent preoperative aortography, including anteroposterior and lateral views. The lateral views demonstrated significant stenosis or occlusion of the celiac artery in all patients, which precluded a splenorenal or hepatorenal bypass (fig. 1, B). However, the superior mesenteric artery was widely patent, which allowed for mesenterorenal bypass in these patients. Immediate postoperative complications consisted of left pneumothorax and· atelectasis in 1 patient, which resolved completely with appropriate treatment. Patency of the reconstructed renal artery has been documented in all patients with conventional or digital subtraction angiography. The postoperative blood pressure was normal in all patients, with 2 requiring low dose antihypertensive medication. All 4 patients are alive 12 to 108 months postoperatively and the level of renal function remains stable or improved. DISCUSSION
Accepted for publication September 7, 1984. * Requests for reprints: Department of Urology, Cleveland Clinic Foundation, 9500 Euclid Ave., Cleveland, Ohio 44106.
An important measure toward limiting surgical mortality after renal revascularization in high risk patients with athero188
SUFERIOR lvtESENTERORENAL BYPASS FOR RENAL RE•/ASCULARIZATION
189
Fm. 1. Patient H. L. A, aortography demonstrates total occlusion of infrarenal aorta and bilateral high grade renal artery stenosis. B, lateral aortogram shows marked stenosis at origin of celiac artery (arrow), while superior mesenteric artery just below is widely patent. C, later film of abdomen shows large marginal artery of Drumm.ond, which fills from superior mesenteric artery. D, after left superior mesenterorenal saphenous vein bypass, digital subtraction angiography reveals patent graft (arrow).
FIG. 2. Patient S. V. A, transbrachial aortogram shows total occlusion of both renal arteries and abdominal aorta below enlarged superior mesenteric artery. Reprinted with permission. 6 B, sketch illustrates right superior mesenterorenal saphenous vein bypass. C, followup aortography 7 years postoperatively shows continued patent right superior mesenterorenal graft.
sclerosis has been the use of techniques that obviate an operation on a badly diseased abdominal aorta. 7 The most frequent alternatives to aortorenal revascularization have been splenorenal, hepatorenal and ileorenal bypasses. 1- 5 These methods are attractive because of their relative simplicity and the fact that they do not jeopardize the sole blood supply to an organ or region. The liver and spleen receive additional vascular supply to that derived from the hepatic and splenic arteries,
respectively. When there is good flow through the diseased aorta and healthy iliac vessels, placement of an ileorenal graft does not interfere with vascularization of the lower extremity owing to the wide caliber of the common iliac artery. The superior mesenteric artery is a more critical vessel, since it provides the sole blood supply to a large portion of the bowel. Nevertheless, the intestines may be protected from ischemia by an abundant collateral circulation. A collateral pathway
190
KHAULI AND ASSOCIATES
Patient characteristics and results following superior mesenterorenal bypass Pt.-Age-Sex SV-58-M LD-63-M
JK-53-M HL-57-M
Aortic Findings lnfrarenal aortic occlusion, bilat. renal artery occlusion Infrarenal aortic occlusion, rt. renal artery occlusion, It. renal artery stenosis Infrarenal aortic occlusion, normal rt. renal artery, It. renal artery stenosis lnfrarenal aortic occlusion, bilat. renal artery stenosis
Serum Creatinine (mg./dl.)
Blood Pressure (mm.Hg)
Operation
Followup (mos.)
Preop.
Postop.
Preop.
Postop.
4.4
2.1
240/140
130/80
Superior mesenteric artery, rt. renal
108
1.2
0.8
210/110
150/85
Superior mesenteric artery, It. renal
65
1.4
1.2
180/120
140/80
Superior mesenteric artery, It. renal
26
1.6
1.2
240/130
140/90
Superior mesenteric artery, It. renal
12
from the celiac axis is obtained via the superior pancreaticoduodenal artery, which communicates with the first branch of the superior mesenteric artery, namely the inferior pancreaticoduodenal artery. Collateral blood supply from the inferior mesenteric artery is provided by the arch of Riolan, which connects with the left and middle colic arteries. The inferior mesenteric artery may, in turn, receive collateral flow from the internal iliac artery via branches from the superior and inferior hemorrhoidal arteries. It has been shown that the bowel can tolerate a significant reduction in blood flow without damage due to this collateral circulation. 8 Our results with superior mesenterorenal bypass in patients with infrarenal aortic occlusion have been satisfactory. Intestinal ischemia has not resulted from this approach, and all 4 patients remain alive with normal blood pressure and stable renal function. In patients with infrarenal aortic occlusion the superior mesenteric artery generally is enlarged, since it supplies collateral vessels to areas vascularized ordinarily by the infrarenal aorta, that is the large bowel, pelvis and lower extremities (fig. 1, C). Use of such an enlarged superior mesenteric artery with improved flow technically facilitates performance of a mesenterorenal bypass and has been well tolerated to date. We have been reluctant to use this approach in patients with a normal-sized superior mesenteric artery and cannot comment on its efficacy in this setting. In summary, the superior mesenterorenal saphenous vein bypass technique has limited and specific indications as a method of renal revascularization. We recommend its use in patients with a surgically difficult aorta in whom a widely patent enlarged superior mesenteric artery is present and when a bypass to the kidney from the celiac or iliac arteries is not possible. One available option in such cases is to perform simultaneous aortic replacement and renal vascularization. However, this approach has been associated with high mortality rates of 5 to 30 per cent. 2 ' 9 - 12 In the absence of a fixed indication to replace the aorta, such as severe ciaudication or an enlarged aneurysm, mesenterorenal bypass allows for a safer and more effective renovascular reconstruction. REFERENCES
1. Novick, A. C., Banowsky, L. H. W., Stewart, B. H. and Straffon,
R. A.: Renal revascularization in patients with severe atherosclerosis of the abdominal aorta or a previous operation on the abdominal aorta. Surg., Gynec. & Obst., 144: 211, 1977. 2. Libertino, J. A. and Selman, F. J., Jr.: Alternatives to aortorenal revascularization. J. Cardiovasc. Surg., 23: 318, 1982. 3. Novick, A. C., Banowsky, L. H. W., Stewart, B. H. and Straffon, R. A.: Splenorenal bypass in the treatment of stenosis of the
renal artery. Surg., Gynec. & Obst., 144: 891, 1977. 4. Chibaro, E. A., Libertino, J. A. and Novick, A. C.: Use of the hepatic circulation for renal revascularization. Ann. Surg., 199: 406, 1984. 5. Novick, A. C. and Banowsky, L. H.: Iliorenal saphenous vein bypass: an alternative for renal revascularization in patients with a surgically difficult aorta. J. Urol., 122: 243, 1979. 6. Hertzer, N. R., Montie, J. E., Hall, P. M. and Banowsky, L. H.: Revascularization of the kidney after occlusion of the aorta and both renal arteries. Surgery, 79: 52, 1976. 7. Novick, A. C., Straffon, R. A., Stewart, B. H., Gifford, R. W. and Vidt, D. G.: Diminished operative morbidity and mortality in renal revascularization. J.A.M.A., 246: 749, 1981. 8. Boley, S. J. and Brandt, L. J.: The pathophysiology of mesenteric blood flow and nonocclusive mesenteric ischemia. In: Surgery of the Aorta and its Body Branches. Edited by J. J. Bergan and J. S. T. Yao. New York: Grune & Stratton, p. 453, 1979. 9. Gomes, M. M. and Bernatz, P. E\-Aorto-iliac occlusive disease. Extension cephalad to origin of renal arteries, with surgical considerations and results. Arch. Surg., 101: 161, 1970. 10. Brewster, D. C., Buth, J., Darling, R. C. and Austen, W. G.: Combined aortic and renal artery reconstruction. Amer. J. Surg., 131: 457, 1976. 11. Shahian, D. M., Najafi, H., Javid, H., Hunter, J. A., Goldin, M. D. and Monson, D. 0.: Simultaneous aortic and renal artery reconstruction. Arch. Surg., 115: 1491, 1980. 12. Foster, J. H., Dean, R.H., Pinkerton, J. A. and Rhamy, R. K.: Ten years experience with the surgical management of renovascular hypertension. Ann. Surg., 177: 755, 1973.
EDITORIAL COMMENT Alternatives to aortorenal saphenous vein bypass grafts for renal revascularization have now become established techniques to revascularize ischemic renal parenchyma safely in patients with hazardous aortic pathological conditions and celiac occlusion. The superior mesenteric artery frequently is the only patent visceral artery available for a bypass source in the patient with diffuse atherosclerosis and compromised renal blood flow. This technique was described first by the authors (reference 6 in article) in 1976 as a single· case report and presently is updated, with 3 additional cases and a long followup on the original case to demonstrate the safety and the stability of the procedure. The authors emphasize the absence of intestinal ischemia or other serious complications compared to the option of aortic replacement with its attendant high mortality rate. This procedure lends itself more readily to left renal artery revascularization but can be used for the right renal artery as well, as illustrated by the first case. The authors rightly note the need for a good, widely patent length of superior mesenteric artery before considering it as a source of bypass and are reluctant to use this approach in patients with a normal size superior mesenteric artery. The technique and results of the procedure emphasize its potential in this uncommon but desperate situation. L.M.Z.