The aneurysm detection and management study screening program: validation cohort and final results. Aneurysm Detection and Management Veterans Affairs Cooperative Study Investigators.

BACKGROUND: We previously reported the prevalence and associations of abdominal aortic aneurysm (AAA) in 73451 veterans aged 50 to 79 years who underwent ultrasound screening. OBJECTIVE: To understand the prevalence of and principal positive and negative risk factors for AAA, and to assess reproducibility of our previous findings. METHODS: In the new cohort of veterans undergoing screening, 52 745 subjects aged 50 to 79 without history of AAA underwent successful ultrasound screening for AAA, after completing a questionnaire on demographics and potential risk factors. RESULTS: We detected AAA of 4.0 cm or larger in 613 participants (1.2%; compared with 1.4% in the earlier cohort). The direction and magnitude of the important associations reported in the first cohort were confirmed. Respective odds ratios for the major associations with AAA for the second and for the combined cohorts were as follows: 1.81 and 1.71 for age (per 7 years), 0.12 and 0. 18 for female sex, 0.59 and 0.53 for black race, 1.94 and 1.94 for family history of AAA, 4.45 and 5.07 for smoking, 0.50 and 0.52 for diabetes, and 1.60 and 1.66 for atherosclerotic diseases. The excess prevalence associated with smoking accounted for 75% of all AAAs of 4.0 cm or larger in the total population of 126 196. Associations for AAA of 3.0 to 3.9 cm were similar but tended to be somewhat weaker. CONCLUSIONS: Our findings confirm our previous cohort findings. Age, smoking, family history of AAA, and atherosclerotic diseases remained the principal positive associations with AAA, and female sex, diabetes, and black race remained the principal negative associations.

Fifteen-year results of ambulatory compression therapy for chronic venous ulcers.

A nonoperative approach to venous stasis ulceration of the lower extremity, consisting of initial bedrest, ulcer cleansing, dressing changes, and ambulatory elastic compression stocking therapy, has been maintained for over 15 years. All patients had class III, severe chronic venous insufficiency. One hundred five of 113 patients (93%) experienced complete ulcer healing in a mean of 5.3 months. One hundred two patients were compliant with elastic compression stockings, and 11 patients were noncompliant. Complete ulcer healing occurred in 99 of 102 patients (97%) who were compliant versus six of 11 patients (55%) who were noncompliant (p less than 0.0001). The influence of noncompliance, previous venous ulceration, previous venous surgery, previous known deep venous thrombosis, peripheral arterial insufficiency (ankle brachial systolic blood pressure index less than or equal to 0.60), pretreatment ulcer duration, ulcer size, age, sex, diabetes, smoking, and photoplethysmography venous refill time on ulcer healing was determined by logistic regression analysis. Only noncompliance with elastic compression stockings (p less than 0.0001) and a pretreatment ulcer duration of more than 9 months (p = 0.02) significantly decreased initial ulcer healing. Posthealing follow-up was available in 73 patients for a mean of 30 months. Fifty-eight patients (79%) continued to be compliant with stockings; 15 patients were noncompliant. Total ulcer recurrence in patients who were compliant was 16%. Five-year lifetable recurrence was 29%. All patients who were noncompliant had recurrent ulceration by 36 months. Previous ulceration, previous venous surgery, and peripheral arterial insufficiency had no effect on ulcer recurrence (p greater than 0.05).

Ability of ankle-brachial index to detect lower-extremity atherosclerotic disease progression.

BACKGROUND: Accurate determination of progression of lower-extremity arterial occlusive disease (LEAOD) is required for natural history studies and evaluation of therapies for atherosclerosis. OBJECTIVE: To determine if changes in the ankle-brachial index (ABI) correlated with progression of LEAOD as determined by arteriography or duplex scanning. DESIGN: In patients with prior suprainguinal or infrainguinal lower-extremity revascularization, progression of LEAOD in native arteries was determined by comparing a preoperative (baseline) arteriogram with late follow-up arteriography or duplex scanning. Superficial femoral and popliteal arteries were graded as having less than 50% stenosis, 50% to 99% stenosis, or as being occluded. Tibial arteries were graded as continuously patent or occluded. Operated and nonoperated extremities were included in the study. The baseline ABI was performed postoperatively and repeated at follow-up arteriography or duplex scanning. Progression of LEAOD by the ABI was defined as a decrease in the ABI of 0.15 or greater. Progression of LEAOD by imaging studies was defined as an increase in 1 category of stenosis. Extremities with suprasystolic pressures were excluded. SETTING: Tertiary vascular surgical service. EXTREMITIES AND PATIENTS: One hundred ninety-three extremities were studied in 114 patients during a mean follow-up of 3.3 years. RESULTS: Seventy-two lower extremities (37.3%) showed progression of atherosclerosis by late follow-up arteriography or duplex scanning. Using the imaging studies as the criterion standard, the ABI had 102 true negatives, 29 true positives, 42 false negatives, and 20 false positives (sensitivity, 41%; specificity, 84%; positive predictive value, 59%; negative predictive value, 71%; and accuracy, 68%) for determining the progression of LEAOD. CONCLUSIONS: The ABI is relatively insensitive in identifying the progression of LEAOD as demonstrated by the use of imaging studies. In studies of natural history or therapy for atherosclerosis, imaging studies should be used in preference to the ABI to evaluate the progression of LEAOD accurately.

Upper extremity ischemia from subclavian artery aneurysm caused by bony abnormalities of the thoracic outlet.

OBJECTIVE: To describe our experience with surgical therapy for upper extremity ischemia incident to emboli from aneurysms of the subclavian artery. DESIGN: Retrospective review case series. SETTING: Vascular surgery practice at a university hospital-based tertiary referral center. PATIENTS: All patients treated for upper extremity ischemia caused by embolism from a subclavian artery aneurysm from January 1, 1990, to July 31, 1996. INTERVENTION: All patients underwent detailed history and physical examination, screening for immunologic and hypercoaguable disorders, noninvasive vascular laboratory evaluation, and arteriography of the aortic arch in both arms and hands. Surgical treatment consisted of rib excision or fracture plating, aneurysm excision, and interposition vein grafting, with additional saphenous vein bypasses to brachial or forearm arteries as needed to provide uninterrupted circulation to the wrist. RESULTS: Twelve patients (6 males; mean age, 37 years) were treated. All had episodic upper extremity ischemia with an initial misdiagnosis of primary vasospastic disorder. Rest pain and/or ischemic ulceration developed in 3. Duration of symptoms before correct diagnosis averaged 7 months (range, 1-36 months). All patients had bony abnormalities of the thoracic outlet (8 cervical ribs, 3 abnormal first ribs, and 1 unstable clavicular fracture). All aneurysms contained intraluminal thrombus, and all patients had multiple ipsilateral distal arm, forearm, and/or hand arterial occlusions indicating chronic and repeated embolization. All patients underwent aneurysm excision and interposition vein grafting, with additional vein bypass to the brachial (3 patients) and/or forearm arteries (5 patients). Mean follow-up was 18 months (range, 2 weeks to 63 months). Eleven patients had complete symptomatic relief, and 1 patient improved. All subclavian interposition grafts remained patient. Two distal bypass grafts occluded in patients with preoperative arteriograms demonstrating no patient forearm arteries. There has been no limb loss. CONCLUSIONS: Hand ischemia caused by embolization from a subclavian artery aneurysm occurs in young patients without atherosclerosis and is frequently misdiagnosed as vasospasm. Despite advanced disease and multiple chronic distal arterial occlusions, surgical treatment by resection of bony abnormalities, aneurysm excision and grafting, and distal bypass grafting produces excellent results.

Prevalence of asymptomatic carotid stenosis in patients undergoing infrainguinal bypass surgery.

BACKGROUND: The prevalence of asymptomatic carotid stenosis in patients with lower-extremity ischemia is unknown. This report represents the largest carotid screening program to date of patients undergoing leg bypass. DESIGN: Patients undergoing infrainguinal bypass from 1987 through 1993 on the vascular surgery service at Oregon Health Sciences University, Portland, underwent routine carotid duplex examinations to detect the presence of asymptomatic carotid stenosis. PATIENTS: During the study period, 352 patients underwent infrainguinal revascularization for ischemia, of whom 225 (64%) had no prior carotid surgery, carotid arteriography, or cerebrovascular symptoms. There were 117 men and 108 women, with a mean age of 67 years. The indication for surgery was limb salvage in 67% and claudication in 33% of patients. RESULTS: Sixty-four patients (28.4%) who required lower-extremity revascularization had hemodynamically significant asymptomatic carotid artery stenosis or occlusion; 12.4% had stenosis of 60% or greater, the qualifying level for randomization in the Asymptomatic Carotid Atherosclerosis Study. Based on these findings, eight patients with carotid stenosis of 80% or greater underwent elective carotid endarterectomy. There were no postoperative neurologic events in the 225 leg bypass patients. By multivariate logistic regression analysis, the presence of carotid bruit (P < .001) and the presence of rest pain (P = .006) were associated with carotid stenosis of 50% or greater. Limiting screening to patients with carotid bruit, limb salvage indications for surgery, and/or advanced age excluded significant numbers of patients with stenosis; thus, these were not effective screening strategies. CONCLUSION: Screening carotid duplex scanning is indicated in patients who require lower-extremity revascularization.

Anticoagulation followed by elective carotid surgery in patients with repetitive transient ischemic attacks and high-grade carotid stenosis.

OBJECTIVE: To evaluate the results of preoperative heparin therapy followed by carotid surgery for patients with repetitive transient ischemic attacks (TIAs) and high-grade carotid stenoses. DESIGN: A 4-year prospective study. SETTING: Oregon Health Science University Hospital and Portland (Ore) Veterans Affairs Hospital. PATIENTS: Twenty-nine consecutive patients with repetitive TIAs referable to 30 high-grade (> or = 70%) ipsilateral carotid stenoses were treated with short-term heparin anticoagulation, followed by cerebral angiography, routine preoperative evaluation, and subsequent carotid reconstruction. INTERVENTIONS: Heparin sodium anticoagulation was maintained for a mean of 5 days. Surgical management consisted of 24 standard endarterectomies, five bypasses to the internal carotid artery, and one external carotid endarterectomy. MAIN OUTCOME MEASURES: Primary outcome variables included perioperative hemorrhage, thrombocytopenia, stroke, and death. Secondary outcome variables included carotid occlusion and recurrent TIAs with heparin therapy. RESULTS: One symptomatic common carotid occlusion and one asymptomatic internal carotid occlusion occurred during preoperative heparin therapy. Thirteen patients had additional sporadic TIAs while receiving heparin. There were no preoperative cerebral infarcts, thrombocytopenia, or clinical bleeding associated with heparin therapy. There was one postoperative stroke and one death due to myocardial infarction. CONCLUSION: When necessary, heparin anticoagulation and delayed carotid reconstruction would appear to be an acceptable alternative to emergency carotid surgery in patients with high-grade carotid stenosis and acute repetitive TIAs.

Isolated bypass to the superior mesenteric artery for intestinal ischemia.

OBJECTIVE: A number of reports indicate revascularization for intestinal ischemia should include the superior mesenteric artery (SMA) and the celiac artery. However, no controlled or randomized studies have proven this approach superior to SMA bypass alone. We report our results using bypass to only the SMA for intestinal ischemia. DESIGN: Retrospective review with mean follow-up of 40 months (range, 2 to 110 months). SETTING: University medical center and Veterans Affairs hospital. PATIENTS/METHODS: The records of patients who underwent intestinal revascularization of the SMA alone from 1982 through 1993 were reviewed. Patients were assessed for indication for operation, operative technique, perioperative mortality, and long-term outcome. The SMA grafts were examined for patency within the last 6 months using duplex scanning or arteriography. Patient survival and graft patency rates were calculated using life-table methods. RESULTS: Twenty-nine bypasses to only the SMA were performed in 26 patients (16 female and 10 male; mean age, 59 years; age range, 13 to 81 years). Indication for operation was symptomatic chronic mesenteric ischemia in 23 cases and acute intestinal ischemia in five cases. One bypass was performed for asymptomatic SMA occlusion. There were three perioperative deaths (10% mortality rate), all in patients with acute intestinal ischemia and previous mesenteric arterial surgery. Life-table 4-year primary graft patency and patient survival rates were 89% and 82%, respectively. Symptomatic improvement was maintained in all patients available for follow-up. CONCLUSION: Revascularization of only the SMA for intestinal ischemia provides excellent graft patency with acceptable perioperative mortality and long-term patient survival. The SMA bypass alone for intestinal ischemia appears as successful as bypasses to multiple visceral vessels.

Analysis of risk factors for myocardial infarction following carotid endarterectomy.

A 4-year experience with 249 consecutive carotid endarter-ectomies performed on 224 patients is reviewed for incidence of perioperative (30-day) myocardial infarction and early survival (mean follow-up, 21 months). Except in cases of unstable angina, coronary arterial disease was evaluated only by routine history, physical examination, and electrocardiogram. By these criteria, 73% of patients had evidence of coronary arterial disease. Patients underwent carotid endarterectomy after appropriate medical management and stabilization of coronary disease symptoms (angina and/or congestive heart failure). One (0.4%) fatal and nine (3.6%) nonfatal perioperative myocardial infarctions Early survival of patients with active symptoms of coronary disease who did not undergo coronary bypass was similar to those patients with preceding or subsequent coronary bypass. The results of this review suggest routine clinical evaluation for coronary arterial disease is sufficient in the large majority of cases prior to carotid endarterectomy. Considering the reported high mortality of coronary bypass among vascular surgical patients, it appears that an aggressive program screening for cardiac surgical candidates either by coronary arteriography or radionuclide studies prior to carotid endarterectomy is not warranted.

Axillofemoral grafting with externally supported polytetrafluoroethylene.

OBJECTIVE: To evaluate the results of axillofemoral bypass grafting using externally supported polytetrafluoroethylene. DESIGN: Consecutive patients who were operated on by us from 1983 to the present were prospectively followed up in a vascular registry. The results of surgery with respect to morbidity and mortality, patency, limb salvage, and patient survival were determined by life-table methods. PATIENTS: A standardized operative technique was used to perform 184 axillofemoral bypass procedures in 164 consecutive patients (age range, 14 to 90 years; mean age, 67 years; female, 33%). Follow-up ranged from 0 to 95 months (mean, 23 months). RESULTS: Ischemia was the indication for 83% of the procedures, and aortic sepsis was the indication for 16%. There were nine operative deaths (5%) and 17 major complications. Life-table primary patency, limb salvage, and survival rates at 5 years were 71%, 92%, and 52%, respectively. Indication for surgery, patency of the superficial femoral artery, and the performance of multilevel procedures did not significantly influence patency. CONCLUSIONS: The results of axillofemoral grafting using polytetrafluoroethylene are equivalent to those achieved with other accepted methods of treatment for lower extremity ischemia, including balloon angioplasty, aortofemoral bypass, and infrainguinal bypass. Axillofemoral bypass is an appropriate technique that is deserving of more widespread use.

Reducing perioperative myocardial infarction following vascular surgery. The potential role of beta-blockade.

OBJECTIVE: To determine which perioperative variables may influence the occurrence of perioperative myocardial infarction (PMI) following vascular surgery. DESIGN: Case-control study. SETTING: Combined Veterans Affairs Medical Center-university hospital vascular service. PATIENTS: During a 4-year period, all major vascular surgical operations (N = 2088) were evaluated with serial postoperative electrocardiography and cardiac enzyme measurements. Patients with PMI following nonemergent vascular surgery (N = 53) were matched with randomly selected control patients without PMI (N = 106) for age, gender, type of operation, hypertension, and symptoms of coronary artery disease. MAIN OUTCOME MEASURES: The two groups were compared for operative blood loss, blood pressure, and heart rate as well as length of operation, type of anesthetic, and use of perioperative beta-blockers, nitroglycerine, calcium channel blockers, vasopressors, and angiotensin-converting enzyme inhibitors. RESULTS: beta-Blockers were used less frequently in patients with PMI than in control patients without PMI (30% vs 50%; P = .01). Overall beta-blockade was associated with a 50% reduction in PMI (P = .03). Perioperative myocardial infarction was not associated with length of operation, type of anesthetic, blood pressure, or use of other medications. CONCLUSIONS: beta-Blockade is associated with a decreased incidence of PMI in patients undergoing vascular surgery. Prophylactic perioperative use of beta-blockers may decrease PMI in patients requiring major vascular surgery. A prospective randomized trial of beta-blockers in these patients appears to be warranted.

Peroneal bypass is equivalent to inframalleolar bypass for ischemic pedal gangrene.

OBJECTIVE: To determine if peroneal bypass is a suitable alternative to inframalleolar bypass in patients with ischemic pedal gangrene. DESIGN: Review of a prospectively acquired vascular registry. SETTING: University practice limited to vascular surgery. PATIENTS: Patients with chronic lower-extremity ischemia and pedal gangrene evaluated between 1985 and 1995 in whom the only options for arterial reconstruction were bypass to the peroneal or an inframalleolar artery. INTERVENTIONS: Peroneal or inframalleolar reverse vein bypass. MAIN OUTCOME MEASURES: Time to healing and lifetable analyses of survival, primary patency, and limb salvage. RESULTS: Eighty-three peroneal and 46 pedal bypasses were performed for ischemic foot gangrene. The groups were equivalent for sex, diabetes mellitus, heart disease, hypertension, renal failure, hypercoagulable states, previous ipsilateral bypass, smoking, and preoperative ankle-brachial indices. Patients with inframalleolar bypass were younger than patients with peroneal bypass (63.9 vs 71.6 years, P = .005) and had higher postoperative ankle-brachial indices (1.02 vs 0.91, P = .004). However, 3-year survival rates (69.1% inframalleolar vs 60.0% peroneal, P = .35), limb salvage rates at 2 years (70.3% vs 85.8%, P = .10), and time to wound healing (19.7 vs 21.6 weeks, P = .66) were equivalent. CONCLUSION: Peroneal and inframalleolar bypass for ischemic pedal gangrene have equivalent intermediate-term survival, limb salvage, and wound healing. Surgeons should not feel obliged to perform inframalleolar bypass for pedal gangrene if peroneal bypass is possible.

Extrathoracic arterial grafts performed for carotid artery occlusive disease not amenable to endarterectomy.

HYPOTHESIS: Extrathoracic cervical grafts are safe and provide long-lasting stroke prevention in patients with disease not amenable to standard carotid bifurcation endarterectomy. DESIGN: Review of a prospectively maintained vascular surgical registry. SETTING: Combined university and Department of Veterans Affairs vascular surgical service. PARTICIPANTS: Patients requiring surgery for carotid atherosclerotic occlusive disease not amenable to endarterectomy from January 1988 to March 1998. INTERVENTIONS: Carotid interposition grafting, subclavian-carotid bypass, or carotid-carotid bypass. MAIN OUTCOME MEASURES: Perioperative stroke and death, and life-table determination of freedom from stroke, stroke-free survival, and graft patency. RESULTS: Sixty patients (mean age, 65.8 years; range, 36-83) underwent cervically based carotid grafting. All had greater than 70% stenosis or occlusion of the innominate, common carotid, or internal carotid arteries, and 30 (50%) had undergone at least 1 previous ipsilateral carotid endarterectomy. Indication for operation was stroke or transient ischemic attack in 46 (77%) and asymptomatic high-grade stenosis in 14 (23%). Operative procedures included 31 (52%) carotid interposition grafts, 18 (30%) subclavian-carotid grafts, and 11 (18%) carotid-carotid grafts. Mean follow-up was 29 months (range, 1-117 months). Perioperative stroke rate was 5% (3/60) all in symptomatic patients, and there were no perioperative deaths. By life-table analysis, freedom from stroke was 92% at 1 and 5 years. Stroke-free survival was 90% at 1 year and 61% at 5 years. Primary graft patency was 94% at 1 year and 84% at 5 years, with assisted primary patency of 90% at 5 years. CONCLUSION: Cervical carotid artery grafts for complicated or recurrent carotid atherosclerosis not amenable to endarterectomy are durable and provide excellent freedom from stroke with low perioperative morbidity and mortality.

Hypoperfusion as a possible factor in the development of gastrointestinal complications after cardiac surgery.

This study has presented the spectrum of postoperative gastrointestinal system complications after open heart surgery at the University of Washington from 1980 through 1983. The frequent necessity for operative intervention and a mortality rate of 17 percent in our study of gastrointestinal complications in patients who have undergone open heart surgery indicates the need for early diagnosis and treatment. The data suggest that bypass times approaching 100 minutes and the presence of postoperative cardiogenic shock are important risk factors in the development of such complications in elective cardiac surgery patients. An incidence of gastrointestinal complications of 8.6 percent in those undergoing repair of acute aortic dissections makes gastrointestinal complaints particularly suspicious in this subgroup.

Neurologic deficits following noncarotid vascular surgery.

Neurologic events following noncarotid vascular surgery (NCVS) are considered unpredictable. To test this hypothesis, we reviewed our vascular registry for a 3-year period and identified all patients with new postoperative focal neurologic events (stroke, hemispheric transient ischemic attack [TIA]) within 2 weeks of a category I or II vascular procedure as defined by the American Board of Surgery, exclusive of carotid surgery and arterial trauma. Thirteen of 1,390 NCVS procedures (0.9%) in 13 patients were associated with focal neurologic events. There were 2 TIAs, 10 anterior circulation strokes, and 1 posterior circulation stroke. Twenty-seven percent of strokes were fatal. The neurologic deficit developed in the immediate postoperative period in 31%, more than 4 hours but less than 72 hours postoperatively in 54%, and within 3 to 14 days postoperatively in 15%. Patients with anterior circulation events (group A, n = 12) were compared for variables potentially influencing postoperative stroke with case controls who were selected using a table of random numbers (group B, n = 12). Controls were derived from a pool of all category I or II NCVS procedures recorded in our vascular registry sequentially during the same time period and who were without new neurologic deficits postoperatively. Using Fisher's exact test, comparisons between groups A and B revealed that new anterior circulation neurologic events in vascular surgical patients tended to be associated with intra-abdominal procedures (p less than 0.05), perioperative hypotension (p less than 0.05), and the presence of a greater than or equal to 50% internal carotid artery stenosis ipsilateral to the neurologic event (p less than 0.001). Such information may prove useful in the management of selected patients prior to arterial reconstruction and in operated NCVS patients with postoperative neurologic events.

"Just in time" decision making for ICU care after carotid endarterectomy.

BACKGROUND: Many patients undergoing carotid endarterectomy (CE) do not require active intensive care unit (ICU) care (AIC). Until recently, all patients spent 24 hours postoperatively in an ICU, but many of these patients were simply monitored and did not need unique ICU services. METHODS: To aid in developing a selective policy for ICU admission following CE, we reviewed preoperative risk factors, recovery room course, and total hospital stay of 126 patients for 2 years when postoperative ICU admission was routine. Preoperative assessment included presence or absence of cardiac disease, hypertension, severe respiratory disease, diabetes, arrhythmia, renal failure, and a Goldman cardiac risk score. The operative, recovery room, and ward records were reviewed for conditions requiring AIC. Requirement for AIC was defined as need for infusion of vasoactive, bronchodilator, or antiarrhythmic medication beyond the recovery room period. In addition, treatment for coronary ischemia or MI, need for active diuresis, perioperative neurological event, or requirement for mechanical ventilation were indications for AIC. RESULTS: There were 132 CEs in 126 patients; 37% required AIC as defined above. When patients who required AIC were compared with patients not requiring AIC, the only significant difference was the number of risk factors per patient. Goldman cardiac risk class I patients were at less risk for cardiac morbidity than the combined Class II and III patients. CONCLUSIONS: In an individual patient, preoperative risk assessment does not aid in predicting the need for AIC following CE. Selection of patients for ICU admission following CE can be accurately determined by a short period of recovery room observation.

Improving survival and limb salvage in patients with aortic graft infection.

A 15-year experience with 38 aortic graft infections, including 15 patients with graft enteric fistulas, is reviewed in order to analyze modern-day surgical results utilizing extra-anatomic bypass and aortic graft excision. Perioperative mortality was 14% during the most recent 7-year interval, which was a notable improvement compared with the earlier time interval (p = 0.06). Extended follow-up of the perioperative survivors demonstrated a 77% cumulative 5-year survival and a 76% cumulative 5-year limb salvage rate. Subsequent axillofemoral graft infection occurred in 22% of survivors and resulted in a significantly higher amputation rate compared with those patients with no axillofemoral graft infection (p less than 0.001). The results suggest good perioperative and long-term survival in patients with aortic graft infection, with excellent limb salvage if subsequent axillofemoral graft infection can be avoided.

Usefulness of fasting and postprandial duplex ultrasound examinations for predicting high-grade superior mesenteric artery stenosis.

PURPOSE: A fasting duplex ultrasound examination of the superior mesenteric artery (SMA) accurately detects high-grade (> 70%) stenosis. It has been postulated that postprandial mesenteric duplex scanning may further stratify stenosis and improve the ability of a fasting examination to detect a high-grade stenosis. We performed fasting and postprandial duplex scanning of 25 healthy controls and 80 patients with vascular disease undergoing aortography to determine whether postprandial mesenteric duplex scanning provides information beyond a fasting study alone. METHODS: Patients with vascular disease were divided into three groups based on lateral aortography results: group 1, 0% to < 30% SMA stenosis (n = 61); group 2, 30% to < 70% stenosis (n = 10); and group 3, 70% to 99% stenosis (n = 9). Fasting mesenteric duplex scanning was defined as positive for 70% to 99% stenosis if the peak systolic velocity (PSV) was > or = 275 cm/s. The ability of either fasting or postprandial mesenteric duplex scanning, and their combination, to predict high-grade (70% to 99%) SMA stenosis was determined using angiographic control. RESULTS: Mean fasting SMA PSV did not differ among controls and groups 1 and 2. Postprandial PSV increased significantly in all groups, but was not different among controls and groups 1 and 2. Mean fasting PSV was significantly higher, and the postprandial increase in PSV significantly lower, in group 3 compared with controls and with groups 1 and 2. Fasting mesenteric duplex scanning predicted 70% to 99% SMA stenosis, with 89% sensitivity, 97% specificity, 80% positive predictive value, 99% negative predictive value, and 96% accuracy. Corresponding values for postprandial scanning were 67%, 94%, 60%, 96%, 91%, and for the combination of normal fasting and postprandial scanning 67%, 100%, 100%, 96%, 96%, respectively. CONCLUSION: Postprandial increases in SMA PSVs are blunted in patients with high-grade stenosis, but feeding velocities do not stratify between lesser degrees of stenosis. Both fasting and postprandial PSVs identify high-grade (> 70%) stenosis. Their combination marginally improves fasting duplex scan specificity and positive predictive value. Postprandial scanning is not necessary for the diagnosis of high-grade stenosis if a fasting study identifies a PSV > or = 275 cm/s. The combination of normal fasting and postprandial mesenteric duplex ultrasound scanning may effectively rule out high-grade SMA stenosis.

Upper extremity thromboembolism caused by occlusion of axillofemoral grafts.

BACKGROUND: The axillofemoral bypass graft (AxFG) is increasingly accepted as treatment for lower extremity ischemia caused by aortoiliac occlusive disease in high-risk patients. The incidence of upper extremity (UE) thromboembolism caused by occlusion of an AxFG and the results of treatment form the basis for this report. METHODS: From 1984 to the present, all patients undergoing axillofemoral bypass grafting were followed up in a vascular registry. A standardized operative technique, using an externally supported 8-mm polytetrafluoroethylene graft, was used in performing 202 AxFGs in 182 patients. UE thromboembolism caused by occlusion of an AxFG was identified by retrospective patient record review. RESULTS: Occlusion of an AxFG occurred in 20 patients. Fifteen patients (75%) underwent immediate revision of the occluded graft. Two patients (10%) developed UE thromboembolism simultaneous with graft occlusion. One of these patients had immediate revision of the graft, and 1 had brachial embolectomy only. This patient and 4 others (25%) had the occluded AxFG left in place. Four of these 5 patients (80%) developed UE thromboembolism at 26 days, 2 years, 5 years, and 7 years, respectively, after occlusion. Overall, six UE thromboembolic complications occurred in 5 patients. CONCLUSIONS: UE thromboembolism represents a significant and specific complication of occluded AxFGs in our series (2.7% of patients, 25% of occluded grafts). It may be prudent to prophylactically detach the axillary portion of the graft and repair the axillary artery in patients who do not require immediate revision of an occluded AxFG.

Predictors of outcome of forefoot surgery for ulceration and gangrene.

BACKGROUND: Surprisingly little is known about the long-term outcome of forefoot surgery for limb salvage. METHODS: From January 1, 1992 through December 31, 1996, patients requiring toe amputation or forefoot surgery were prospectively entered into a computerized database and followed up for healing, need for repeat foot surgery, or major amputation (below or above knee). RESULTS: A total of 162 patients (mean age 65 years), 72% diabetic, 10% with end-stage renal disease (ESRD), and 73% without palpable pulses, were entered into the study. Mean follow-up was 25 months. Of patients without palpable pulses (n = 98), 83% underwent concomitant or subsequent limb revascularization. Eleven of 98 revascularization procedures (11%) were hemodynamically unsuccessful. Nonhealing of the initial forefoot procedure occurred in 14%, and late repeat foot surgery (following initial healing) was required in an additional 14%. Major amputation was eventually required in 30 (18.5%) patients. Multivariate analysis indicated that unsuccessful revascularization, but not diabetes or ESRD, predicted nonhealing and major amputation (P <0.0001). Patients presenting with palpable pulses and neuropathic ulcers were at risk for late, repeat foot surgery, but not major amputation (P = 0.0015). CONCLUSIONS: In patients requiring toe or partial forefoot amputation, success of revascularization is the primary predictor of initial healing and freedom from major amputation. Neuropathic ulceration predicts need for repeat foot surgery following healing.

Surgical treatment of infected aortic aneurysm.

BACKGROUND: We report results of infected aortic aneurysms treated by a single group over 20 years. METHODS: Retrospective review. RESULTS: Seventeen patients were treated, 10 with infrarenal and 7 suprarenal infections. All had abdominal/back pain, 88% were febrile, 71% had leukocytosis, and 24% were hemodynamically unstable. The most common responsible organism was Staphylococcus aureus (29%) followed by Salmonella organisms (24%). All suprarenal infections were gram-positive organisms. Infrarenal infections were treated with preliminary axillofemoral bypass followed by aortic resection. Suprarenal infections were treated with either in situ prosthetic graft or patch repairs. Operative survival was 90% for infrarenal and 57% for suprarenal infections. Operative deaths occurred in the setting of overwhelming sepsis and/or severe preoperative hemodynamic instability. There was no limb loss, renal failure, or intestinal ischemia. Late deaths occurred in 4 patients at 1.3 to 6.3 years postoperatively and were unrelated to their aortic repairs. Nine patients remain alive with a median follow-up of 2 years. There have been no late aortic or graft infections. CONCLUSIONS: In the absence of hemodynamic instability and uncontrolled sepsis, infected aortic aneurysms can be successfully repaired with durable results.