Prophylactic Revascularization Research Articles

Natural history of atherosclerotic renal artery stenosis associated with aortic disease

The natural history of atherosclerotic renal artery stenosis has not been well defined, particularly when discovered in conjunction with aortic disease requiring correction. To better define the natural history of such lesions, 194 sequential aortograms in 48 patients were studied to define predictive criteria for stenoses at risk for progression. Sixty-six unsuspected atherosclerotic renal arterial stenoses were identified on the initial aortograms. Disease progressed in 42 arteries (53%), 14 bilateral and 28 unilateral. Seven arteries developed occlusion. All had stenoses averaging 80% (range 61% to 94%) noted on the most recent aortogram preceding occlusion. Risk factors including smoking, diabetes mellitus, elevated serum lipids, coronary artery disease, peripheral arterial disease, or change in blood pressure or creatinine, did not correlate with degree or rate of progression of the renal artery stenosis. A difference in kidney size, although varying inversely with degree of stenosis, was not a statistically significant marker of disease progression. This analysis suggests that identification of renal arterial stenoses that will progress is best determined by sequential aortography. Highly stenotic vessels are more prone to occlude than those less stenotic. Consequently, individuals with preocclusive lesions should benefit from prophylactic renal revascularization during aortic reconstruction.

Asymptomatic celiac and superior mesenteric artery stenoses are more prevalent among patients with unsuspected renal artery stenoses

The prevalence of unsuspected renal artery stenosis among patients with peripheral vascular disease has been reported to be as high as 40%, but the prevalence of asymptomatic celiac and superior mesenteric artery stenoses in these patients is not known. The biplane aortograms of 205 male patients who were military veterans and had aneurysms or occlusive disease were independently reviewed, and medical records were studied to determine associated coronary disease, risk factors, and patient outcome. Fifty-six patients (27%) had a 50% or greater stenosis in the celiac or superior mesenteric artery, and seven patients (3.4%) had significant stenoses in both mesenteric arteries. Patients with celiac or superior mesenteric artery stenoses were older (p = 0.002) and had a higher prevalence of hypertension (p = 0.029) than those without significant mesenteric stenoses. Fifty of the 205 patients had significant renal artery stenoses, and 20 had advanced (greater than 75% diameter loss) renal stenoses. Ten of the 20 patients (50%) with advanced renal stenoses had a concomitant celiac artery stenosis, compared to 40 of the 185 patients (22%) who did not have advanced renal stenoses (p = 0.011). In the present study asymptomatic celiac or superior mesenteric artery stenoses were common among male veterans evaluated for peripheral vascular disease, but the prevalence of significant stenoses in both the celiac and superior mesenteric arteries was low. The prevalence of significant celiac stenosis was higher in patients with advanced (greater than 75%) renal artery stenoses who might be considered for prophylactic renal revascularization. Lateral aortography with evaluation of the celiac artery is always appropriate in these patients.

Mesenteric Infarction in Takayasu's Disease

Obstructive lesions of the visceral arteries in Takayasu's disease are common but rarely symptomatic. This report concerns two patients with Takayasu's disease who died of mesenteric infarction due to superior mesenteric artery thrombosis. Prophylactic revascularization of the visceral arteries in Takayasu's disease remains controversial, and lesions can be more severe than classically recognized.

Aortic Reimplantation of the Superior Mesenteric Artery for Atherosclerotic Lesions of the Visceral Arteries: Sixty Cases

We report the results of a series of patients who had isolated or associated reimplantation of the superior mesenteric artery directly into the infrarenal aorta. Between 1967 and 1988, a total of 91 revascularizations for atheromatous lesions of the visceral arteries were performed in 89 patients. The superior mesenteric artery was reconstructed in 87 instances, 60 of which were direct or indirect reimplantations into the juxtarenal aorta. The procedure was isolated in 51 cases, and associated with the revascularization of another visceral artery in nine cases. These 60 patients were divided into three groups: Group A--seven patients undergoing emergency operation for acute intestinal ischemia; Group B--30 patients operated upon for chronic intestinal angina; and Group C--22 asymptomatic patients who underwent prophylactic revascularization. Two patients died in the immediate postoperative period (3.5%). Although most of the 29 late deaths were due to vascular disorders, only one was secondary to intestinal infarction. Twenty-one patients followed had good functional results; six patients had relapse of abdominal pain. Three of these underwent repeat revascularization of the superior mesenteric artery 12 days, 18 months, and 22 months, postoperatively. Follow-up ranged from six months to 18 years. Two patients were lost to follow-up. Overall actuarial survival at five years was 69.60 +/- 15%. In our experience, isolated reimplantation of the superior mesenteric artery on the anterior aspect of the infrarenal aorta is a simple and reliable technique which affords good long-term results.

Surgical treatment of chronic mesenteric arterial insufficiency

The treatment of 41 patients with chronic mesenteric insufficiency is reviewed: 20 men and 21 women with a mean age of 59 years were treated and observed for an average of 42 months. Thirty-one patients had symptoms of intestinal angina whereas 10 patients underwent prophylactic revascularization during other aortic operations. All but one patient had revascularization of the superior mesenteric artery, alone or in combination with another revascularization. Various surgical techniques were used, including retrograde bypass in 24 patients, antegrade bypass in 11 patients, and endarterectomy in the remaining six patients. Seven patients had acute abdominal symptoms and required emergency operation while in the hospital awaiting elective revascularization. There were two deaths in the perioperative period (4.9%), both caused by bowel necrosis. Six patients are known to have had late revascularization failure, resulting in recurrent symptoms in three patients and two subsequent deaths. All patients who remained asymptomatic after late graft failure had undergone multiple vessel revascularization; no patient revascularized prophylactically had symptoms of intestinal angina during the follow-up period. Early mesenteric revascularization is a safe and effective method of relieving the symptoms of chronic visceral ischemia and may prevent the development of fatal bowel necrosis.

Late survival in abdominal aortic aneurysm patients: The role of selective myocardial revascularization on the basis of clinical symptoms

Coronary artery disease is recognized as the major cause of perioperative and late death after abdominal aortic aneurysm (AAA) repair. Routine coronary angiography and prophylactic myocardial revascularization for all significant lesions, regardless of symptoms, have been recommended as a means of reducing this mortality risk. We have advocated a more selective approach in which coronary angiography and myocardial revascularization are performed on the basis of cardiac symptoms. Studies have shown that this selective approach is just as effective as the prophylactic approach in reducing perioperative deaths. To evaluate the effect on late survival of selective myocardial revascularization on the basis of symptoms, we reviewed the preoperative coronary status and course of 485 patients who successfully underwent AAA repair between 1980 and 1985. Late survival was evaluated by means of the Kaplan-Meier method and compared with life expectancy of an age- and sex-matched population. Late survival of the entire group of patients was no different from that of the matched population. Patients with no preoperative evidence of coronary artery disease did significantly better than expected (p = 0.05), whereas those patients with uncorrected or previously bypassed coronary disease had survival no different from that expected. When age was considered as a variable, patients in their 50s and 60s had survival significantly worse than the matched population (p < 0.001 and p = 0.003, respectively). Patients in their 70s and 80s had survival as good as or better than the matched population, regardless of coronary status. Selective management of coronary artery disease on the basis of cardiac symptoms provides acceptable late survival in patients older than 70 years of age. Younger patients had survival worse than expected and may benefit from a more aggressive approach to the management of cornary artery disease.

Gangrene of the immediate postoperative above-knee amputation stump: Role of emergency revascularization in preventing death

Two hundred seventy-five lower extremity amputations were performed over a 4-year interval for end-stage peripheral vascular disease. Fourteen patients (8.5%) of a total of 165 patients undergoing above-knee amputation (AKA) either suffered acute gangrenous ischemia of the AKA stump postoperatively, or were thought to be at high risk for same, and therefore underwent prophylactic inflow revascularization prior to or concomitant with AKA. The overall operative mortality rate was 28.5% in these 14 patients and was related either to inability to revascularize (two of three patients) or to the attempt to revascularize in the presence of a frankly necrotic amputation stump (three of five patients). Lower extremity amputation may be performed with an overall acceptably low mortality rate, which for our series is 0.9% for 113 below-knee amputation (BKA) and 2.8% for 140 AKA levels. Acute postoperative gangrene of the stump carries a high mortality rate and may be prevented by inflow revascularization prior to amputation. Three situations were identified as carrying a high risk for the subsequent development of gangrene: acute thrombosis of a prior combined inflow/outflow procedure, occlusion of the superficial femoral artery with an occluded/stenotic deep femoral artery and no palpable femoral pulse, and flat pulse volume recordings at the high thigh level. Patients who present for AKA with one of these indications should be considered as a candidate for prophylactic inflow revascularization prior to AKA to prevent ascending gangrene.

Gangrene of the immediate postoperative above-knee amputation stump: role of emergency revascularization in preventing death.

Two hundred seventy-five lower extremity amputations were performed over a 4-year interval for end-stage peripheral vascular disease. Fourteen patients (8.5%) of a total of 165 patients undergoing above-knee amputation (AKA) either suffered acute gangrenous ischemia of the AKA stump postoperatively, or were thought to be at high risk for same, and therefore underwent prophylactic inflow revascularization prior to or concomitant with AKA. The overall operative mortality rate was 28.5% in these 14 patients and was related either to inability to revascularize (two of three patients) or to the attempt to revascularize in the presence of a frankly necrotic amputation stump (three of five patients). Lower extremity amputation may be performed with an overall acceptably low mortality rate, which for our series is 0.9% for 113 below-knee amputation (BKA) and 2.8% for 140 AKA levels. Acute postoperative gangrene of the stump carries a high mortality rate and may be prevented by inflow revascularization prior to amputation. Three situations were identified as carrying a high risk for the subsequent development of gangrene: acute thrombosis of a prior combined inflow/outflow procedure, occlusion of the superficial femoral artery with an occluded/stenotic deep femoral artery and no palpable femoral pulse, and flat pulse volume recordings at the high thigh level. Patients who present for AKA with one of these indications should be considered as a candidate for prophylactic inflow revascularization prior to AKA to prevent ascending gangrene.

Trends in reconstruction for atherosclerotic renal vascular disease

Twenty-eight patients underwent renal vascular reconstruction for atherosclerotic renal vascular stenosis. Ten patients had therapeutic renal artery reconstruction for isolated renal artery stenosis causing severe hypertension, nine patients had therapeutic renal artery reconstruction for severe hypertension combined with simultaneous aortic reconstruction, and nine patients had prophylactic renal artery reconstruction for renal artery stenosis combined with simultaneous aortic reconstruction. Ninety percent of patients undergoing therapeutic renal revascularization procedures for hypertension were cured or improved. The 10 patients undergoing prophylactic renal artery reconstruction combined with aortic reconstruction had an average 72 percent reduction in the diameter of the vessel. Dacron side grafts sutured to the aortic graft were used for revascularization in each of the patients with prophylactic revascularization and was found to be an expedient means of reconstruction with good patency rates. No increased morbidity or mortality rate was noted in the prophylactic group. We believe that prophylactic revascularization should be carried out in patients with atherosclerotic high-grade stenosis of the renal arteries to prevent hypertension and preserve renal function.

Prognosis and treatment of asymptomatic coronary artery disease

Despite the large number of studies dealing with the natural history of angiographically defined coronary artery disease, there is still a paucity of data on the prognosis of totally asymptomatic persons. From the small number of reported studies, it appears that prognosis in selected asymptomatic patients may be better than that of symptomatic patients. However, the annual mortality rate in the subgroup of asymptomatic patients with triple vessel disease was as high as 4 to 5% in some studies that included patients with prior myocardial infarction or mild symptoms, or both. This has reinforced the views of those who advocate a more aggressive medical/surgical approach to asymptomatic patients with left main and triple vessel disease, especially if they have had a prior infarction. Although several small series of surgically treated patients have been reported to have excellent short-term survival rates, the absence of adequate control groups in nearly all of these studies has left the issue of prophylactic revascularization unresolved. Until there is more knowledge of prognosis in patients not operated on, it is likely to remain unresolved.

Mesenteric vascular problems. A 26-year experience.

Mesenteric vascular problems are infrequent, but may be catastrophic. During a 26-year period, 55 private patients were treated for the following disorders: (1) 12 patients with visceral artery aneurysms, (2) 8 with celiac compression syndrome, (3) 13 with chronic mesenteric ischemia, (4) 12 with acute mesenteric ischemia, and (5) 10 with mesenteric ischemia associated with aortic reconstructions. Splenic artery aneurysms were managed by excision and splenectomy, while celiac and hepatic had excision with graft replacement. Patients with celiac compression syndrome underwent lysis of the celiac artery. Two patients had compression of both celiac and superior mesenteric artery (SMA). One patient required vascular reconstruction of both arteries for residual stenoses. Patients having chronic mesenteric ischemia were treated with bypass grafts, with one death (7.7% mortality) and good long-term results. Those with acute mesenteric ischemia were treated by SMA embolectomy, bowel resection, or both, with a mortality of 67%. When associated with aortic reconstructions, mesenteric ischemia carried a mortality of 100% if bowel infarction occurred after operation, but when prophylactic mesenteric revascularization was performed at the time of aortic surgery, prognosis was greatly improved, with only one death among six patients. An aggressive approach including prompt arteriography with early diagnosis and surgical therapy is advocated for these catastrophic acute mesenteric problems.

Prophylactic Coronary Artery Grafting in Patients with Few or No Symptoms

Fifty-five patients who underwent prophylactic coronary artery grafting were followed for 4 to 8 years. Sixteen patients had no angina, and 39 were in New York Heart Association Functional Class I. Twenty-one patients had single-vessel disease, 13 had double-vessel disease, and 27, triple-vessel disease. A total of 101 grafts were inserted. There were no operative deaths. Two patients suffered a perioperative myocardial infarction (MI), and 3 were reoperated on for persistent bleeding. Early after operation, 9 of the 45 grafts were occluded. At 1 year, 2 patients had occlusion of all grafts, and 1 had similar findings at 5 years. There were 4 late deaths, 3 related to coronary artery disease. Seven patients sustained a late MI. Thirty-one of the 51 survivors (60.8%) seen late (mean, 69.3 months) after operation were free from angina; 14 were in Class I and 6, Class II. It is apparent from this retrospective study that patients such as these stand to benefit little from prophylactic revascularization. Longevity may be increased, however, in patients who are asymptomatic after MI.