John W. Hallett

Circulating and Tissue Endothelin Immunoreactivity in Advanced Atherosclerosis

BACKGROUND Atherosclerosis is characterized by endothelial injury and the proliferation of arterial smooth-muscle cells. The latter may be a result of the release of growth factors from the vessel wall; such growth factors may include an endothelium-derived vasoconstrictor for peptide with mitogenic properties. We tested the hypothesis that plasma endothelin concentrations are elevated in persons with symptomatic atherosclerosis, independently of age. METHODS We measured plasma endothelin levels in 100 normal subjects and in 40 patients with atherosclerosis predominantly of the following types: aortic and peripheral vascular disease (14 patients), renovascular disease (9 patients) coronary artery disease (9 patients), and carotid disease (8 patients). We also performed immunohistochemical staining for endothelin in the walls of atherosclerotic vessels. RESULTS In the normal subjects, the mean (+/- SD) plasma endothelin concentration was 1.4 +/- 0.2 pmol per liter, with no correlation between age and plasma endothelin concentration (r = 0.13, P = 0.2). In the patients with symptomatic atherosclerosis, the mean plasma endothelin concentration was 3.2 +/- 1.2 pmol per liter (P less than 0.001), and there was a significant correlation between plasma endothelin and the number of sites of disease involvement (r = 0.89, P less than 0.001). In the immunohistochemical studies, endothelin-1-like immunoreactivity was observed in vascular smooth muscle as well as in endothelial cells. CONCLUSIONS Endothelin may be a marker for arterial vascular disease. Whether it participates in the atherogenic process or is merely released from damaged endothelial cells is unclear.

Prognosis of abdominal aortic aneurysms: a population-based study

Information is incomplete about the rate of expansion of abdominal aortic aneurysms and the risk of rupture in relation to their size. To address these questions, we conducted a population-based study. Of the 370 residents of Rochester, Minn., with an aneurysm initially diagnosed from 1951 through 1984, 181 had the aneurysm documented by ultrasound examination. Among the 103 patients who underwent more than one ultrasound study, the diameter of the aneurysm increased by a median of 0.21 cm per year. Only 24 percent had a rate of expansion of 0.4 cm or more per year. Among the 176 patients who had an unruptured aneurysm at the time of the initial ultrasound study, the cumulative incidence of rupture was 6 percent after 5 years and 8 percent after 10 years. However, the risk of rupture over five years was 0 percent for the 130 patients with an aneurysm less than 5 cm in diameter and 25 percent for the 46 patients with an aneurysm 5 cm or more in diameter. All 16 patients who had ruptures had aneurysms that were 5 cm or more in diameter at the time of the rupture. These population-based data challenge the clinical perception that aneurysms typically expand at a rate of 0.4 to 0.5 cm per year. Our data also suggest that for aneurysms less than 5 cm in diameter the risk of rupture is considerably lower than has been reported previously. However, the risk of rupture is substantial for aneurysms 5 cm or more in diameter.

Graft-related complications after abdominal aortic aneurysm repair: Reassurance from a 36-year population-based experience

PURPOSE Graft-related complications must be factored into the long-term morbidity and mortality rates of abdominal aortic aneurysm (AAA) repair. However, the true incidence may be underestimated because some patients do not return to the original surgical center when a problem arises. METHODS To minimize referral bias and loss to follow-up, we studied all patients who underwent AAA repair between 1957 and 1990 in a geographically defined community where all AAA operations were performed and followed by a single surgical practice. All patients who remained alive were asked to have their aortic grafts imaged. RESULTS Among 307 patients who underwent AAA repair, 29 patients (9.4%) had a graft-related complication. At a mean follow-up of 5.8 years (range, < 30 days to 36 years), the most common complication was anastomotic pseudoaneurysm (3.0%), followed by graft thrombosis (2.0%), graft-enteric erosion/fistula (1.6%), graft infection (1.3%), anastomotic hemorrhage (1.3%), colon ischemia (0.7%), and atheroembolism (0.3%). Complications were recognized within 30 days after surgery in eight patients (2.6%) and at late follow-up in 21 patients (6.8%). These complications were observed at a median follow-up of 6.1 years for anastomotic pseudoaneurysm, 4.3 years for graft-enteric erosion, and 0.15 years for graft infection. Kaplan-Meier 5- and 10-year survival free estimates were 98% and 96% for anastomotic pseudoaneurysm, 98% and 95% for combined graft-enteric erosion/infection, and 98% and 97% for graft thrombosis. CONCLUSIONS This 36-year population-based study confirms that the vast majority of patients who undergo standard surgical repair of an abdominal aortic aneurysm remain free of any significant graft-related complication during their remaining lifetime.

Acute Aortic Dissection: Population-Based Incidence Compared With Degenerative Aortic Aneurysm Rupture

OBJECTIVES To ascertain whether acute aortic dissection (AAD) remains the most common aortic catastrophe, as generally believed, and to detect any improvement in outcomes compared with previously reported population-based data. PATIENTS AND METHODS We determined the incidence, operative intervention rate, and long-term survival rate of Olmsted County, Minnesota, residents with a clinical diagnosis of AAD initially made between 1980 and 1994. The incidence of degenerative thoracic aortic aneurysm (TAA) rupture was also delineated. We compared these results with other population-based studies of AAD, degenerative TAA, and abdominal aortic aneurysm (AAA) rupture. RESULTS During a 15-year period, we identified 177 patients with thoracic aortic disease. We focused on 39 patients with AAD (22% of the entire cohort) and 28 with TAA rupture (16%). The annual age- and sex-adjusted incidences were 3.5 per 100,000 persons (95% confidence interval, 2.4-4.6) for AAD and 3.5 per 100,000 persons (95% confidence interval, 2.2-4.9) for TAA rupture. Thirty-three dissections (85%) involved the ascending aorta, whereas 6 (15%) involved only the descending aorta. Nineteen patients (49%) underwent 22 operations for AAD, with a 30-day case fatality rate of 9%. Among all 39 patients with AAD, median survival was only 3 days. Overall 5-year survival for those with AAD improved to 32% compared with only 5% in this community between 1951 and 1980. CONCLUSIONS In other studies, the annual incidences of TAA rupture and AAA rupture are estimated at approximately 3 and 9 per 100,000 persons, respectively. This study indicates that AAD and ruptured degenerative TAA occur with similar frequency but less commonly than ruptured AAA. Although timely recognition and management remain problematic, these new data suggest that recent diagnostic and operative advances are improving long-term survival in AAD.

Mesenteric venous thrombosis: Still a lethal disease in the 1990s

PURPOSE This study was designed to evaluate progress in diagnosis, management, and clinical outcome of mesenteric venous thrombosis (MVT). METHODS We retrospectively reviewed the clinical course of 72 patients treated for mesenteric venous thrombosis between 1972 and 1993. RESULTS Fifty-three patients had acute and 19 had chronic mesenteric venous thrombosis. Fifty-seven patients had secondary mesenteric venous thrombosis; previous abdominal surgical procedure and hypercoagulable states were the most prevalent associated conditions. Computed tomography was abnormal in all patients who underwent this test for acute mesenteric venous thrombosis and in 93% of those who had chronic disease. Angiography diagnosed acute mesenteric venous thrombosis in five (72%) of seven patients. Acute mesenteric venous thrombosis presented most frequently as abdominal pain (83%), anorexia (53%), and diarrhea (43%). Thirty-three (75%) had symptoms longer than 48 hours. Thirty-four (64%) patients with acute mesenteric venous thrombosis underwent a surgical procedure. Bowel resection was necessary in 31 patients. One patient had unsuccessful mesenteric venous thrombectomy. Seven patients with acute mesenteric venous thrombosis underwent anticoagulation without a surgical procedure, and 12 were observed. All patients with chronic mesenteric venous thrombosis were observed; nine of the 19 underwent anticoagulation. The median delay in diagnosis for patients with acute mesenteric venous thrombosis was 48 hours and did not decrease during the last decade. Mesenteric venous thrombosis recurred in 19 (36%) patients. The 30-day mortality was 27%. Long-term survival of patients with acute mesenteric venous thrombosis was significantly worse than that of those with chronic disease (36% vs 83% survival at 3 years). The patients with acute mesenteric venous thrombosis who underwent anticoagulation with and without surgical procedure had improved survival when compared with the observed group. CONCLUSION Acute mesenteric venous thrombosis remains a lethal disease. Mortality has not improved in the last 22 years. Computed tomography is the most sensitive diagnostic test. Anticoagulation and surgical procedure enhanced survival in the acute subgroup. The underlying disease determined survival in chronic disease.

Inflammatory abdominal aortic aneurysms: A thirty-year review

The operative records of 2816 patients undergoing repair for abdominal aortic aneurysm (AAA) from 1955 to 1985 were reviewed. Inflammatory aortic or iliac aneurysms were present in 127 patients (4.5%), 123 men and four women. Most patients were heavy smokers (92.1%). Clinical evidence of peripheral arterial occlusive disease and coronary artery disease was found in 26.6% and 39.4%, respectively. Additional aneurysms occurred in half of the patients; iliac aneurysms were the most common (55 patients), followed by thoracic or thoracoabdominal (17 patients), femoral (16 patients), and popliteal aneurysms (10 patients). Ultrasound and computed tomography suggested the diagnosis in 13.5% and 50%, respectively; angiography was not helpful. Excretory urographic findings of medial ureteral displacement or obstruction suggested the diagnosis in 31.4%. The aneurysm was repaired in 126 patients. Only one patient experienced acute aneurysm rupture, but eight patients had chronic contained leakage. When compared with patients who have ordinary atherosclerotic aneurysms, patients with inflammatory aneurysms are significantly more likely to have an elevated erythrocyte sedimentation rate (ESR, 73% vs. 33%, p less than 0.0001); weight loss (20.5% vs. 10%, p less than 0.05); symptoms (66% vs. 20%, p less than 0.0001); and an increased operative mortality rate (7.9% vs. 2.4%, p less than 0.002). The triad of chronic abdominal pain, weight loss, and elevated ESR in a patient with an abdominal aortic aneurysm is highly suggestive of an inflammatory aneurysm and may be beneficial in the preoperative preparation of the patient for aneurysm repair.

Incidental Renal Artery Stenosis Among a Prospective Cohort of Hypertensive Patients Undergoing Coronary Angiography

OBJECTIVE To determine the feasibility, safety, and clinical yield of angiographic screening among hypertensive patients undergoing coronary angiography. PATIENTS AND METHODS This study was a prospective cohort analysis of hypertensive patients who underwent cardiac catheterization at a tertiary care referral center from July 1998 to March 1999. Abdominal aortography was performed to screen for renal artery stenosis, the percentage of which was measured. RESULTS The mean +/- SD age of the 297 study patients was 64.9+/-10.2 years; 58.6% were male, and 98.0% were white. Mean +/- SD systolic/diastolic blood pressure was 142.8+/-22.5/79.6+/-11.4 mm Hg. Aortography required a mean incremental dose of 62+/-9 mL of nonionic contrast agent. No complications were attributable to aortography. Of 680 renal arteries, 611 (90%) were visualized adequately. Also, 53% of patients had normal renal arteries, 28% had stenoses less than 50%, and 19.2% had stenoses of 50% or more. Renal artery stenosis was bilateral in 3.7% of patients and high grade (>70% stenosis) in 7%. Patients with renal artery stenosis were more likely to have had a previous coronary intervention. In multivariate analysis, systolic blood pressure (odds ratio [OR], 1.2; 95% confidence interval [CI], 1.03-138; P=.02), history of stroke or transient ischemic attack (OR, 2.7; 95% CI, 1.27-5.78; P=.01), and cancer (OR, 2.0; 95% CI, 1.02-3.82; P=.04) independently correlated with renal artery stenosis of 50% or more. CONCLUSION The prevalence of incidental renal artery stenosis among hypertensive patients undergoing coronary catheterization is significant. Therefore, screening abdominal aortography should be considered in these patients to better define their risk of cardiovascular complications.

Replacement of the inferior vena cava for malignancy: an update.

OBJECTIVES Resection and replacement of the inferior vena cava (IVC) to remove malignant disease is a formidable procedure. Since our initial report with IVC replacement for malignancy, we have maintained an aggressive approach to these patients. The purpose of this review is to update our experience with regard to patient selection, operative technique, and early and late outcome. METHODS All patients who had IVC replacement for primary (n = 2) or secondary (n = 27) vena cava tumors from April 1990 to May 1999 were reviewed. Tumor location and type, clinical presentation, the segment of IVC replaced, graft patency, performance status of the patient, and tumor recurrence and survival data were collected. Late follow-up data were available for all but one patient. The IVC was replaced in 28 patients with large diameter (> or =14 mm) externally supported ePTFE grafts and with a panel graft of superficial femoral vein in the other. Three patients had a femoral arteriovenous fistula. Graft patency was determined before hospital dismissal and in follow-up by vena cavography, computed tomography, ultrasonography, or magnetic resonance imaging. RESULTS There were 18 women and 11 men, with a mean age of 53.1 years (range, 16-88 years). Over one half of patients had symptoms from their tumor. IVC replacement was at the suprarenal segment in 15 patients, of whom 13 had concomitant major hepatic resection, at the infrarenal segment in 10, at both caval segments in three, and at the renal vein confluence in one. There were two early deaths (6.9%). One patient died intraoperatively of coagulopathy during liver resection and suprarenal IVC replacement. The other death occurred 4 months postoperatively, from multisystem organ failure that resulted in graft infection and occlusion. Twelve patients had one or more major complications- cardiopulmonary problems in five; bleeding in five; chylous ascites or large pleural effusions in two patients each; and lower extremity edema with tibial vein thrombosis in one. The mean follow-up was 2.8 years (range, 2.7 months to 6.3 years). Two late graft occlusions occurred: one at 7.5 months, the other, from tumor recurrence, at 6.3 years. There have been no other late graft-related complications. All 11 late deaths were caused by the progression of malignant disease. Of 16 survivors, 12 have no evidence of disease and four have either regional or distant metastatic recurrence. Initial postoperative performance status was good or excellent for most survivors. CONCLUSIONS Aggressive surgical management may offer the only chance for cure or palliation of symptoms for patients with primary or secondary IVC tumors. Our experience suggests that vena cava replacement may be performed safely with low graft-related morbidity and good patency in carefully selected patients.

Ruptured abdominal aortic aneurysms: Repair should not be denied

The records of 231 patients (189 men, 42 women) treated during the last decade for ruptured infrarenal abdominal aortic aneurysm were reviewed to evaluate complications and mortality rates and to determine if preoperative factors would preclude attempt at surgical repair. Mean age was 73.7 years (range, 50 to 95 years). Fifty-seven patients (24.7%) were greater than or equal to 80 years of age. Sixty-eight patients (29.4%) had known abdominal aortic aneurysm before rupture. Preoperative systolic blood pressure was less than or equal to 90 mm Hg in 155 patients (67.1%). Fifty-six patients (24.2%) had cardiac arrest before operation. The overall mortality rate from admission until the end of the hospital stay was 49.4% (114 of 231). Seventeen patients (7.4%) died in the emergency department, 40 (17.3%) in the operating room, 27 (11.7%) during the first 48 postoperative hours, and 30 (13.0%) died later but during the same hospitalization. The 30-day operative mortality rate was 41.6%. Mean age of those who died was higher (75.3 years) than of those who survived (72.2 years) (p less than 0.02). Of patients greater than or equal to 80 years, 43.9% survived. Survival was lower among women (35.7%) than men (54.0%; p less than 0.04). A high APACHE II score, a low initial hematocrit, preoperative hypotension, and chronic obstructive pulmonary disease were associated multivariately with increased mortality rates (p less than 0.02). However, 59 of the 155 patients (38.1%) with preoperative hypotension survived. Deaths were high (80.4%) among patients with cardiac arrest (45 of 56); still, 28.2% of patients (11 of 39) survived repair after cardiac arrest.(ABSTRACT TRUNCATED AT 250 WORDS)

Trends in neurovascular complications of surgical management for carotid body and cervical paraganglionmas: A fifty-year experience with 153 tumors

Almost 75% of carotid body and cervical paragangliomas are adherent to or surround adjacent arteries and cranial nerves. Their resection can result in neurovascular injury, stroke, and excessive blood loss. To assess trends in neurovascular complications, we reviewed 153 carotid body and cervical paragangliomas that were surgically managed between 1935 and 1985. Results of the past 10 years were compared with two previous time periods: period I (1935 to 1965), when carotid artery reconstruction was uncommon at our institution, and period II (1966 to 1975), when methods of intraoperative electroencephalographic monitoring and carotid patch angioplasty were being developed. During the past 10 years (period III), surgical approach to these tumors has included intraoperative monitoring of cerebral blood flow, selective use of shunts, vein patch or graft reconstructions after extensive tumor resections, and mobilization of the parotid gland to facilitate adequate exposure of high tumors. Although tumor resection was attempted in 80% of patients in period I, surgical resection was complete in 98% during periods II and III. Three trends were observed: (1) The perioperative stroke rate has decreased dramatically from 23% in period I to 2.7% in period III (p = 0.007); (2) the perioperative mortality rate has been reduced from 6% in period I to no deaths in the past 10 years, but (3) the rate of postoperative cranial nerve dysfunction remains unchanged over 50 years (period I, 46%; period III, 40%). The median tumor size among patients with postoperative complications was significantly larger than those without complications (median size: 17 vs. 7 cm3, p = 0.004).(ABSTRACT TRUNCATED AT 250 WORDS)