Infected aortic aneurysms: aggressive presentation, complicated early outcome, but durable results.

OBJECTIVE: Infected aortic aneurysms are rare, difficult to treat, and associated with significant morbidity. The purpose of this study was to review the management and results of patients with infected aortic aneurysms and identify clinical variables associated with poor outcome. METHODS: The clinical data and early and late outcomes of 43 patients treated for infected aortic aneurysms during a 25-year period (1976-2000) were reviewed. Variables were correlated with risk of aneurysm-related death and vascular complications, defined as organ or limb ischemia, graft infection or occlusion, and anastomotic or recurrent aneurysm. RESULTS: Infected aneurysms were infrarenal in only 40% of cases. Seventy percent of patients were immunocompromised hosts. Ninety-three percent had symptoms, and 53% had ruptured aneurysms. Surgical treatment was in situ aortic grafting (35) and extra-anatomic bypass (6). Operative mortality was 21% (9/42). Early vascular complications included ischemic colitis (3), anastomotic disruption (1), peripheral embolism (1), paraplegia (1), and monoparesis (1). Late vascular complications included graft infection (2), recurrent aneurysm (2), limb ischemia (1), and limb occlusion (1). Mean follow-up was 4.3 years. Cumulative survival rates at 1 year and 5 years were 82% and 50%, respectively, significantly lower than survival rates for the general population (96% and 81%) and for the noninfected aortic aneurysm cohort (91% and 69%) at same intervals. Rate of survival free of late graft-related complications was 90% at 1 year and 5 years, similar to that reported for patients who had repair of noninfected abdominal aortic aneurysms (97% and 92%). Variables associated with increased risk of aneurysm-related death included extensive periaortic infection, female sex, Staphylococcus aureus infection, aneurysm rupture, and suprarenal aneurysm location (P <.05). For risk of vascular complications, extensive periaortic infection, female sex, leukocytosis, and hemodynamic instability were positively associated (P <.05). CONCLUSION: Infected aortic aneurysms have an aggressive presentation and a complicated early outcome. However, late outcome is surprisingly favorable, with no aneurysm-related deaths and a low graft-related complication rate, similar to standard aneurysm repair. In situ aortic grafting is a safe and durable option in most patients.

Intraoperative duplex ultrasound during carotid endarterectomy.

The purpose of this study was to examine the technical aspects of intraoperative duplex ultrasound (DUS) following carotid endarterectomy (CEA), suggest criteria to differentiate significant lesions requiring immediate surgical revision from normal or benign defects, and evaluate how frequently intraoperative DUS provides useful or unsuspected information. A retrospective study was performed on all patients who had both CEA and intraoperative carotid DUS between January 1, 1990, and January 1, 1995. A total of 155 DUS examinations were performed in 149 patients. Findings were grouped into three categories: normal; minor/insignificant lesions; and hemodynamically significant lesions based on the presence or absence of elevated peak systolic velocities, visible stenosis/thrombus, or intimal flap/dissection. Postoperative status was correlated with intraoperative DUS findings. Ninety-one (59%) examinations performed on 87 patients produced normal findings. Forty-seven (30%) examinations performed on 45 patients showed minor abnormalities consisting of insignificant residual plaque, residual external carotid artery stenoses, small intimal flaps, elevated velocities with no associated anatomic lesion, or an arterial kink. Fourteen patients (9%) had significant findings requiring immediate surgical revision. These consisted of large intimal flaps or dissection in six patients, marked residual plaque and significant stenosis in five patients, thrombus in two patients, and a kink in one patient. Three additional patients (2%) had significant findings but were not revised for various reasons. No significant difference was identified in morbidity or mortality rates between those patients with normal findings, those patients with minor technical defects, and those patients with significant abnormalities undergoing immediate surgical revision. However, two of three patients who had significant abnormalities within the common carotid artery that were not revised suffered perioperative ipsilateral strokes. Intraoperative DUS is a safe and accurate method to assess the technical adequacy of CEA. Intraoperative DUS showed significant lesions in 11% of patients. Identification and immediate repair of significant technical defects may decrease perioperative complication rate and long-term restenosis rate.

Ruptured abdominal aortic aneurysms: the excessive mortality rate of conventional repair.

OBJECTIVE: Rupture of abdominal aortic aneurysms (AAAs) remains lethal. In a report of patients treated in the 1980s, we recommended aggressive management. Our continued experience prompted us to reevaluate this policy. METHODS: We reviewed clinical variables affecting outcome, morbidity, mortality, and trends in mortality of all patients managed at our institution with ruptured AAAs between January 2, 1980, and November 30, 1998. RESULTS: The study group included 413 consecutive patients, 339 men and 74 women. The mean age was 74.3 years (range, 49-96); 116 (28%) patients were older than 80 years. AAA was diagnosed before rupture in 119 (29%) patients. Eighty (19%) patients had preoperative cardiac arrest. Twenty-nine (7%) patients died before operation; 65 (17%) died during the operation. The surgical mortality rate (30-day) was 37%; the overall mortality rate was 45% and was higher in women (68%) than in men (40%) (P <.001). Advanced age, APACHE (Acute Physiology and Chronic Health Evaluation) II score, initial hematocrit, and preoperative cardiac arrest were associated multivariately with 30-day mortality rates by means of stepwise logistic regression (P <.05). Twelve (23%) of 53 patients with cardiac arrest survived the operation. Logistic regression, adjusted for age, sex, and APACHE II score, demonstrated a decrease in overall and 30-day mortality rates (P <.001) over 18 years. The mean overall mortality rate was 51% from 1980 to 1984 and 42% from 1994 to 1998. CONCLUSIONS: The mortality rate of ruptured AAAs remains excessive, despite improvement over 18 years. Patients older than 80 years with shock or cardiac arrest have the highest mortality rate and should be evaluated for possible endovascular treatment. Because the diagnosis of AAA was unknown in more than 70% of patients, screening of the high-risk population and elective repair are recommended.

Genetic similarity in inflammatory and degenerative abdominal aortic aneurysms: a study of human leukocyte antigen class II disease risk genes.

PURPOSE: Clinically, abdominal aortic aneurysms (AAAs) display a spectrum of inflammation that extends from apparently noninflamed (degenerative) AAAs to the classic inflammatory variant. Genes encoded in the human leukocyte antigen (HLA) region are important in the development of both variants of AAA; however, their role in progression to the inflammatory variant is unknown. The purpose of this study was to compare HLA class II genes in patients with degenerative versus classic inflammatory AAAs and to quantify their impact as disease risk factors. METHODS: Genotypes of the 12 major alleles of the HLA-DR B1 locus were determined in patients with degenerative (102) and inflammatory (40) AAAs who were compared with controls (118). Univariate and multivariate logistic regression analyses were used to determine allele distributions and to quantify disease risk. RESULTS: Distribution of the HLA-DR B1 alleles was nonrandom and similar in both degenerative and inflammatory AAA groups compared with controls. The B1*02 and B1*04 alleles were enhanced in both degenerative (39.2% vs. 25.4%, P =.03; and 35.3% vs. 24.6%, P =.08 respectively) and inflammatory (47.5% vs. 25.4%, P =.01; and 32.5% vs. 24.6%, P =.09, respectively) AAAs compared with controls. The B1*02 and B1*04 alleles were associated with risk for both degenerative (odds ratio [OR] 2.2; 95% CI, 1.2-4.0; and OR 2.0; 95% CI, 1.1-3.7, respectively) and inflammatory AAAs (OR 3.7; 95% CI, 1.8-8.6; and OR 2.5; 95% CI, 1.1-6.1). CONCLUSION: This study demonstrates that identical HLA alleles function as genetic risk factors for both inflammatory and degenerative AAAs. These results support the concept of a common, immune-mediated pathogenesis for AAAs that may be modulated by HLA-independent factors.

Rehabilitation of the geriatric vascular amputee patient: a population-based study.

OBJECTIVES: To determine the rate of successful prosthetic fitting in geriatric vascular amputees in the community and to determine predictors of successful fit. DESIGN: Epidemiologic survey. SETTING: General community, Olmsted County, Minnesota. PATIENTS: All Olmsted County residents more than 65 years old who had a major lower extremity amputation (below knee amputation [BKA] or higher) for peripheral vascular disease between 1974-1995, of whom 199 were identified. Median age at amputation was 79.7 years with a median survival of 1.5 years. INTERVENTION: A retrospective chart review. MAIN OUTCOME MEASURE: Successful prosthetic fit. RESULTS: Amputation levels were: 64% BKA, 4.5% knee disarticulation, 31% above knee amputation (AKA), and 0.5% hip disarticulation. Only 36% of the population was successfully fitted, compared with 74% of patients referred to the Amputee Clinic. Major reasons for not being fitted included death, reamputation, cerebrovascular disease, and cognitive deficits. Increased age (p < .001), cerebrovascular disease (p < .001), dementia (p = .002), and AKA (p < .001) were associated with failure to fit. CONCLUSION: The high probability of successful prosthetic fitting reported among referral practices cannot be generalized to unselected elderly individuals. However, selected individuals can successfully be fitted with a prosthesis; knowledge of predictors of prosthetic fitting may facilitate setting of realistic goals during presurgical counseling in this age group.

Predicting the future of vascular health care: the impact of the baby boom generation.

With the aging of the "Baby Boomers," the need for vascular care will be substantial. Three things predominate: (1) variability in distribution of the work force, (2) increasing use of all vascular procedures, and (3) marked geographic variation as to who receives vascular therapy. The mandate to standardize therapy with the least resource utilization and the best results will only strengthen with time.

Redefined duplex ultrasonographic criteria for diagnosis of carotid artery stenosis.

OBJECTIVE: To evaluate duplex ultrasonographic criteria for the determination of 50% or more and 70% or more stenosis of the diameter of the internal carotid artery based on conventional angiography in order to align ultrasonographic diagnostic categories with current clinical management schemes. PATIENTS AND METHODS: Between January 1, 1995, and June 30, 1999, 915 patients underwent both carotid duplex ultrasonography and cerebral angiography within 30 days at Mayo Clinic, Rochester, Minn. Of these patients, 294 were excluded from this study because of occlusion of one or both of the internal carotid arteries or atypical flow characteristics. In the remaining 621 patients (61 % male, 39% female; mean age, 67.7 years [range, 14-88 years]), 1218 vessels were available for correlation. Several Doppler ultrasonographic velocity variables were compared with the angiographic findings by use of receiver operating characteristic curve analysis. The primary end point was verification of optimal ultrasonographic criteria to diagnose 70% or more internal carotid artery stenosis. The secondary end point was establishment of threshold values to detect stenosis of 50% or more. RESULTS: At angiography, 382 patients had internal carotid arteries with 70% or more stenosis. Peak systolic and end diastolic velocities of the internal carotid artery and internal carotid artery:common carotid artery peak systolic velocity ratios were measured. For an internal carotid artery stenosis of 70% or more, a peak systolic velocity of 230 cm/s or more resulted in a sensitivity of 86.4%, a specificity of 90.1%, a positive predictive value of 82.7%, a negative predictive value of 92.3%, and an accuracy of 88.8%. An end diastolic velocity of 70 cm/s or more and an internal carotid artery:common carotid artery ratio of 3.2 or more yielded similar values. For an internal carotid artery stenosis of 50% or more, a peak systolic velocity of 130 cm/s or more resulted in a sensitivity of 92.1 %, a specificity of 89.5%, a positive predictive value of 90.3%, a negative predictive value of 91.3%, and an overall accuracy of 90.8%. An internal carotid artery:common carotid artery ratio of 1.6 or more yielded similar values. CONCLUSION: In our ultrasonography laboratory, a carotid artery stenosis of 70% or more (for which carotid endarterectomy is typically recommended in symptomatic patients) is diagnosed reliably with the following duplex ultrasonographic criteria: a peak systolic velocity of 230 cm/s or more, an end diastolic velocity of 70 cm/s or more, or an internal carotid artery:common carotid artery ratio of 3.2 or more.

Aortic fenestration for acute or chronic aortic dissection: an uncommon but effective procedure.

BACKGROUND: Aortic fenestration is rarely required for patients with acute or chronic aortic dissection. To better define its role and the indications for its use and to evaluate its success at relieving organ or limb malperfusion, we reviewed our experience with direct fenestration of the aorta. METHODS: A retrospective analysis of all consecutive aortic fenestrations performed between January 1, 1979, and December 31, 1999, was performed. Fourteen patients, 12 men and two women (mean age, 59.6 years; range, 43-81), underwent fenestration of the aorta. All patients were hypertensive and had a history of tobacco use. By Stanford classification, there were three type A and 11 type B patients. In the acute dissection group (n = 7), indications for surgery were malperfusion in six patients (leg ischemia, 4; renal ischemia, 5; bowel ischemia, 3) and intra-abdominal bleeding from rupture in two. In the chronic dissection group (n = 7), indications for surgery were abdominal aortic aneurysm in 4 patients (infrarenal, 3; pararenal, 1), thoracoabdominal aneurysm in 1, hypertension from coarctation of the thoracic aorta in 1, and aortic occlusion with disabling claudication in 1. RESULTS: Emergency aortic fenestration was performed in seven patients (surgically for 6 and percutaneously for 1). Fenestration level was infrarenal in four and pararenal in three. Concomitant abdominal aortic graft replacement was performed in four patients, combined with ascending aortic replacement (n = 1) and bilateral aortorenal bypasses (n = 1). In two patients, acute fenestration was performed for organ malperfusion after prior proximal aortic replacement (ascending aorta, 1; descending thoracic aorta, 1). Seven elective aortic fenestrations were performed for chronic dissection (descending thoracic aorta, 2; paravisceral aorta, 2; infrarenal aorta, 2 and pararenal aorta, 1). Concomitant aortic replacement was performed in six patients (abdominal aorta, 5; thoracoabdominal aorta, 1). Fenestration was successful at restoring flow in all 10 patients with malperfusion. Operative mortality for emergency fenestration was 43% (3/7). The three deaths that occurred were of patients with anuria or bowel ischemia, or both. There were no postoperative deaths for elective fenestration. At a mean follow-up of 5.1 years, there were no recurrences of malperfusion and no false aneurysm formations at the fenestration site. CONCLUSION: Fenestration of the aorta can effectively relieve organ or limb ischemia. Bowel ischemia and anuria are indicators of dismal prognosis and emergency fenestration in these patients carries a high mortality. Elective fenestration combined with aortic replacement can be performed safely in chronic dissection. Aortic fenestration is indicated for carefully selected patients with malperfusion and offers durable benefits.

Management of abdominal aortic aneurysms.

Rupture of an abdominal aortic aneurysm (AAA) remains a common vascular catastrophe in all emergency departments. Currently, the natural history of AAAs indicates that risk of rupture increases considerably when the aneurysm is greater than 5 cm in diameter. Appropriate management of aneurysms is elective repair for patients with a good operative risk whose aneurysm is between 5 and 6 cm. For patients with a serious medical comorbidity, the threshold for AAA repair is usually 6 cm. Surgical management is generally safe with extraordinarily durable results. Another current option is an investigational endovascular stent graft, but the long-term outcome for these new devices remains unknown. In addition, optimal medical management should include careful control of hypertension and smoking cessation. The current prognosis for healthy patients who undergo elective aneurysm repair is excellent.

Physiologic responses to laparoscopic aortofemoral bypass grafting in an animal model.

OBJECTIVE: To measure and compare the physiologic, metabolic, and hemodynamic responses to aortofemoral bypass grafting by three techniques: open or conventional laparotomy, laparoscopic-assisted (minilaparotomy), and totally laparoscopic grafting. METHODS: Twenty-four laboratory-bred hounds were randomized to one of three groups (open, laparoscopic-assisted, or totally laparoscopic). Four sets of parameters were measured: hemodynamic (intraoperative continuous cardiac output monitoring), inflammatory or hematologic (serial leukocyte and platelet levels), metabolic responses (serial blood glucose, serum cortisol and insulin, plasma epinephrine, plasma norepinephrine, and dopamine levels), and catabolic (24-hour urinary nitrogen excretion). RESULTS: Cardiac output increased transiently with aortic cross-clamping, more in the laparoscopic-assisted and total laparoscopic groups than in the open group, but the differences were not significant. White blood counts nearly doubled within 12 hours of surgery but were similar in all three groups. Platelet counts decreased significantly in all three groups, but no significant intergroup effects were observed. Metabolic parameters (e.g., blood glucose, cortisol, and catecholamine) rose significantly during surgery but fell to normal within 24 hours, with no important difference between groups. For the first 24 hours, urinary urea excretion fell by 50% but returned to normal by 7 days in all three groups. CONCLUSIONS: In the experimental animal model, the hemodynamic, hematologic, and metabolic responses to laparoscopic and laparoscopic-assisted aortofemoral bypass grafting are similar to those produced by conventional laparotomy graft placement. These data call into question whether laparoscopic techniques for aortic surgery have a significant physiologic advantage in humans.

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.

Aortic-origin reconstruction of the great vessels: risk factors of early and late complications.

OBJECTIVE: Great vessel reconstruction for arterial occlusive disease has been shown to be a durable procedure. The purpose of this report is the examination of the influence of cause and risk factors on outcomes for the identification of patients who may be better treated with endovascular techniques or other surgical approaches. METHODS: Data for patients who underwent aortic-origin great vessel reconstruction between 1988 and 1998 were reviewed. The data were analyzed with Fisher exact test, life-table analysis, and log-rank test. RESULTS: Ninety-two vessels underwent revascularization in 58 patients (15 men, 43 women; mean age, 54 years; age range, 20 to 82 years). Etiology was atherosclerosis obliterans (n = 40; 69%), Takayasu's arteritis (n = 13; 22%), radiation arteritis (RA; n = 4; 7%), and mediastinal fibrosis (n = 1; 2%). The symptoms were cerebrovascular (n = 25), upper extremity (n = 8), or both (n = 23), and two patients were asymptomatic. The bypass grafting was performed with single-limb synthetic grafts (n = 23) or grafts plus side arms (n = 28). Seven patients underwent innominate endarterectomy. The mean follow-up period was 45 months (range, 0 to 126 months). The perioperative stroke (n = 4; 7%) and death (n = 2; 3%) rates were not related to the cause of disease. The patients with creatinine levels of 2 or more (n = 4) had a combined perioperative stroke/death rate of 50% (vs 7% for patients with healthy creatinine levels; P <.05). The patients with hypercoagulable states (ie, thrombophilia; n = 6) had an increased perioperative stroke rate (33% vs 4% for patients without hypercoagulable states; P <.05) and an increased late thrombosis rate. The primary and secondary graft patency rates at 5 years were 80% +/- 7% and 91% +/- 5%, respectively. Patients with RA had a greater risk of stroke or death at 3 years (33% free of stroke or death vs 79% for patients with atherosclerosis obliterans and 92% for patients with Takayasu's arteritis; P =.02) and an increased major late infection rate (50% vs 2% for all others; P =.01). CONCLUSION: Patients with thrombophilia and renal insufficiency have increased perioperative stroke and stroke/death rates, respectively. Patients with RA have an increased incidence rate of late major infection, which directly contributes to an increased rate of stroke or death. Patients with thrombophilia have an increased rate of late graft thrombosis. These patient conditions should be approached cautiously, and some patients may benefit from endovascular therapy.

Mobile thrombi in the abdominal aorta in cases of lower extremity embolic arterial occlusion: value of extended transthoracic echocardiography.

BACKGROUND: Lower extremity embolic arterial occlusion is often associated with proximal atherosclerotic and/or aneurysmal disease. Fixed atherosclerotic disease of the abdominal aorta has been demonstrated by ultrasonography, tomographic studies, and aortography, but mobile debris has not previously been described. We report detection of mobile thrombi in the abdominal aorta during transthoracic echocardiography screening in 6 patients with lower extremity embolic arterial occlusion. METHODS: Six patients were referred to the echocardiography laboratory for evaluation of a source of peripheral arterial embolism. The transthoracic echocardiogram was extended to include longitudinal and transverse images of the abdominal aorta. Additional investigations included abdominal ultrasound (6 patients), computed tomography (2 patients), angiography (2 patients), and transesophageal echocardiography (4 patients). RESULTS: Six patients (4 men, 2 women, aged 46 to 79 years) presented with a blue toe syndrome consistent with atheroembolism. During transthoracic echocardiography with examination of the abdominal aorta, all were found to have significant atherosclerotic disease of the abdominal aorta with one or more mobile components. This finding had a significant impact on treatment of each patient. Surgical resection of the involved portion of the abdominal aorta in one patient demonstrated an ulcerated atheroma with overlying thrombus. CONCLUSION: In patients with lower extremity embolic arterial occlusion, evaluation of the abdominal aorta during transthoracic echocardiography should be a routine extension of the echocardiographic examination. The finding of mobile thrombi in the abdominal aorta identifies a potential source of embolism for which effective treatment exists.

The results of in situ prosthetic replacement for infected aortic grafts.

BACKGROUND: Treatment of aortic graft infection with graft excision and axillofemoral bypass may carry an increased risk of limb loss, aortic stump blowout, and pelvic ischemia. A review of patients with aortic graft infection treated with in situ prosthetic graft replacement was undertaken to determine if mortality, limb loss, and reinfection rates were improved with this technique. METHODS: The clinical data of 25 patients, 19 males and 6 females, with a mean age of 68 years (range 35 to 83), with aortic graft infection, treated between January 1, 1989, and December 31, 1998, by in situ prosthetic graft replacement were reviewed. Follow-up was complete in the 23 surviving patients and averaged 36 months (range 4 to 103). RESULTS: Twenty aortofemoral, 3 aortoiliac, and 2 straight aortic graft infections were treated with excision and in situ replacement with standard polyester grafts in 16 patients (64%), or with rifampin-soaked collagen or gelatin-impregnated polyester grafts in 9 patients (36%). Fifteen patients (60%) had aortic graft enteric fistulas, 8 patients (32%) had abscesses or draining sinuses, and 2 patients (8%) had bacterial biofilm infections. Thirty-day mortality was 8% (2 of 25). There were no early graft occlusions or amputations. There was one late graft occlusion. There were no late amputations. The reinfection rate was 22% (5 grafts). All reinfections occurred in patients operated upon for occlusive disease. Only one reinfection occurred in the rifampin-soaked graft group (11% versus 29%, P = NS). Reinfection tended to be lower in patients with aortoenteric fistulas and without abscess. Autogenous tissue coverage provided statistically significant protection against reinfection. There were no late deaths related to in situ graft infection. CONCLUSIONS: Patients treated with in situ graft replacement had an 8% mortality and 100% limb salvage rate. Reinfection rates were similar to those of extra-anatomic bypass, but a trend of lower reinfection rates with rifampin-impregnated grafts was apparent. Patients with aortoenteric fistula and without abscess appear to be well treated by the technique of in situ prosthetic grafting and autogenous tissue coverage.

Thrombosis of an aortobifemoral bypass graft after total hip arthroplasty.

Arterial complications after total hip arthroplasty are relatively rare but potentially limb or life threatening. We report a case of an arterial thrombosis occurring in a patient with an aortobifemoral bypass graft after primary total hip arthroplasty.

Endovascular repair of abdominal aortic aneurysms: where do we stand?

Endovascular repair of abdominal aortic aneurysms has evolved dramatically within the past few years. In light of the potential to reduce morbidity and mortality associated with open surgical repair, endoluminal grafting offers therapeutic options to patients who are not surgical candidates because of comorbidities. With the development of bifurcated devices, more complex aneurysms may be treated by endovascular grafting. Although successful placement of endovascular grafts requires a pronounced learning curve, including appropriate patient selection, midterm results seem consistent with those of traditional open repair of aneurysms. This review describes the current indications, minimal requirements, different devices and associated techniques, and potential complications of endoluminal repair of abdominal aortic aneurysms. Future aspects of endoluminal grafting are also discussed.

Improved prognosis of thoracic aortic aneurysms: a population-based study.

CONTEXT: Managing thoracic aortic aneurysms identified incidentally by increased use of computed tomography, echocardiography, and magnetic resonance imaging is problematic, especially in the elderly. OBJECTIVE: To ascertain whether the previously reported poor prognosis for individuals with thoracic aortic aneurysms has changed with better medical therapies and improved surgical techniques that can now be applied to aneurysm management. DESIGN: Population-based cohort study. SETTING AND PATIENTS: All 133 patients with the diagnosis of degenerative thoracic aortic aneurysms among Olmsted County, Minnesota, residents between 1980 and 1994 compared with a previously reported cohort of similar patients between 1951 and 1980. MAIN OUTCOME MEASURES: The primary clinical end points were incidence, cumulative rupture risk, rupture risk as a function of aneurysm size, and survival. RESULTS: In contrast to abdominal aortic aneurysms, for which men are affected predominately, 51% of thoracic aortic aneurysms were identified in women who were considerably older at recognition than men (mean age, 75.9 vs 62.8 years, respectively; P= .01). The overall incidence rate of 10.4 per 100000 person-years (95% confidence interval [CI], 8.6-12.2) between 1980 and 1994 was more than 3-fold higher than the rate from 1951 to 1980. The cumulative risk of rupture was 20% after 5 years. Seventy-nine percent of ruptures occurred in women (P= .01). The 5-year risk of rupture as a function of aneurysm size at recognition was 0% for aneurysms less than 4 cm in diameter, 16% (95% CI, 4%-28%) for those 4 to 5.9 cm, and 31% (95% CI, 5%-56%) for aneurysms 6 cm or more. Overall 5-year survival improved to 56% (95% CI, 48%-66%) between 1980 and 1994 compared with only 19% between 1951 and 1980 (P<.01). CONCLUSIONS: In this population, elderly women represent an increasing portion of all patients with clinically recognized thoracic aortic aneurysms and constitute the majority of patients whose aneurysm eventually ruptures. Overall survival for thoracic aortic aneurysms has improved significantly in the past 15 years.

The Mayo Vascular Center experience.

American medicine is trending toward an increasing number of specialty care centers. Cancer centers, transplant centers, and sports medicine centers are only a few common examples. Vascular centers are relatively new entities that are forming for obvious reasons. As the general population ages, peripheral vascular disease has become more prevalent. Several types of medical, surgical, and radiological specialists are involved in the diagnosis and treatment of such patients. Creating multispecialty vascular centers is one method to focus expert care on the patient, to alleviate some of the turf battles between specialties, and to contain burgeoning Medicare costs.

Aorto-caval and ilio-iliac arteriovenous fistulae.

BACKGROUND: To determine optimal management of major abdominal arteriovenous fistulae and define factors affecting outcome. METHODS: We reviewed clinical data of 18 patients, 16 males and 2 females, who underwent repair of major abdominal arteriovenous fistulae between 1970 and 1997. RESULTS: Sixteen patients had primary fistula, caused by rupture of an atherosclerotic aortic or aortoiliac aneurysm into the inferior vena cava (IVC), iliac, or left renal vein. Two had secondary, iatrogenic arteriovenous fistulae. Seventeen patients (94%) were symptomatic, 11 (62%) had acute presentation. Fistula was diagnosed preoperatively in 8 (44%). Fistula closure (direct suture 16, patch 1, iliac vein ligation 1) was followed by aortoiliac reconstruction in all patients. Caval clip was placed in 3 patients. Early mortality was 6%; 7 patients had major complications. During follow-up (mean 6.1 years) 2 patients died of causes related to fistula closure. CONCLUSIONS: Rupture of aortoiliac aneurysms into the iliac veins or IVC carries a better prognosis than intraperitoneal, retroperitoneal, or enteric rupture. Although preoperative diagnosis is ideal, a high index of suspicion, careful repair avoiding pulmonary embolization, and blood salvage were all helpful in keeping morbidity and mortality low. Our data suggest that IVC interruption is seldom warranted.