The clinical course of new-onset atrial fibrillation after elective aortic operations.

BACKGROUND: The onset of atrial fibrillation (AFIB) in the postoperative setting has been associated with increased morbidity and mortality in patients undergoing major noncardiothoracic operations. The purpose of this study was to determine the incidence, associated complications, and outcomes of AFIB after open aortic operations. STUDY DESIGN: We studied 211 consecutive patients undergoing elective aortic operations at a single hospital during a recent 6-year period. Postoperatively all patients had continuous ECG monitoring in the ICU for a mean (+/- SD) of 6 +/- 8 days and routine cardiac enzyme determinations. RESULTS: AFIB developed in 22 of the 211 patients (10%), a mean (+/- SD) of 2 +/- 1 days after operation, and it lasted for a mean of 4 +/- 6 days after onset. Sixteen patients spontaneously reverted to normal sinus rhythm, 3 required cardioversion (2 chemical, 1 electrical), and 3 continued in AFIB at discharge. Four of the 22 patients suffered additional cardiac complications, including antecedent MI in 3 (14%) and sustained cardiogenic shock requiring electrical cardioversion in 1. By comparison, the incidence of MI in the other 189 patients was 4% (no significant difference [NSD]). There were no deaths in the AFIB patients. Cardiac emboli developed in none of the 22 patients, and all patients had normal sinus rhythm on ECG obtained a mean of 14 +/- 10 months after discharge. Comparing the 22 patients with AFIB with the 189 patients without AFIB, there were no differences in the mean duration of ICU stay (6 +/- 4 versus 6 +/- 8 days), total length of hospital stay (10 +/- 5 versus 11 +/- 10 days), or hospital mortality (0% versus 0.5%). AFIB patients were older (71 versus 66 years, p = 0.016), but there was no difference in gender or use of beta-blockers between the two groups. CONCLUSIONS: These data suggest that AFIB is not uncommon after aortic operations but is not associated with increased morbidity, mortality, or length of hospital stay. Although a minority of affected patients can have other cardiac complications such as MI, these complications are usually recognized before the onset of AFIB. AFIB does not affect the outcomes of aortic operations. Most patients will revert spontaneously to normal sinus rhythm and do not require longterm anticoagulation to prevent thromboembolic complications.

Aortic graft infections: replacement with autogenous vein.

The purpose of this review article is to summarize our published experience with the use of the superficial femoral-popliteal vein (SFPV) to replace infected aortic prostheses. The SFPV has proven to be resistant to infections of all types and has shown no signs of degeneration over the long term. Since SFPV bypass and prosthetic graft excision are performed as a single stage, operative times are extensive. Therefore, it may not be appropriate for the sickest patients with severe medical comorbidities. Nevertheless, the operation has been associated with gratifyingly low mortality and amputation rates that are far better than published rates associated with graft excision and extra-anatomic bypass. It is particularly suited to patients with complex aortofemoral graft reconstructions who cannot undergo extra-anatomic revascularization for technical reasons. The venous sequella of SFPV harvest are minimal. These data and those from three other centers support the conclusion that graft excision and replacement with SFPV is an excellent alternative for treatment of aortic graft infections.

Asymptomatic carotid stenosis and unrelated operations: should we be more aggressive?

BACKGROUND: Carotid lesions will often remain asymptomatic during the perioperative period, so prophylactic carotid endarterectomy (CEA) has not been advocated before other operations. The purpose of this study was to characterize the clinical manifestations of new neurologic symptoms occurring in patients with previously asymptomatic carotid occlusive disease who have undergone recent operations. STUDY DESIGN: We performed a retrospective review of patients developing neurologic symptoms attributable to carotid occlusive disease after unrelated operations. RESULTS: Eleven patients (mean age 68+/-6.4 years, 8 men, 3 women) developed new neurologic symptoms from previously asymptomatic extracranial carotid stenoses after 11 unrelated procedures. Neurologic events included hemispheric stroke (n = 10) and amaurosis fugax (n = 1). Two intraoperative strokes occurred (one mastectomy, one prostatectomy). Other events occurred a mean of 5.8+/-5 (range 1 to 16) days after aortic surgery (n = 2), infrainguinal bypass (n = 3), contralateral CEA for symptomatic disease (n = 2), incisional herniorrhaphy (n = 1), and prostate surgery (n = 1). Responsible internal carotid artery lesions were all stenoses greater than 80%; seven were clearly greater than 90%. Those suffering intraoperative stroke or stroke within 24 hours of operation (n = 3) were not receiving antithrombotic therapy. All other events (n = 8) occurred despite the use ofantiplatelet or anticoagulant agents. Four underwent emergent CEA. Four had elective CEA performed after reaching a neurological recovery plateau. CONCLUSIONS: Critical, asymptomatic internal carotid artery stenoses may cause neurologic symptoms after unrelated surgical procedures.

Acute pancreatitis after abdominal vascular surgery.

BACKGROUND: Retroperitoneal dissection and ischemia have been proposed as risk factors for postoperative pancreatitis. Although both are routine components of abdominal vascular operations, postoperative pancreatitis has not been adequately evaluated in vascular patients. The purpose of this study was to determine the incidence and outcomes of pancreatitis after abdominal vascular surgery. STUDY DESIGN: We collected pre-, intra-, and postoperative data on 21 patients who developed pancreatitis after abdominal vascular operations. For comparison, we studied 21 age- and gender-matched case controls undergoing identical operations during the same period. RESULTS: The incidence of pancreatitis among all patients undergoing abdominal vascular operations during the 6-year study period was 1.8%. Pancreatitis was diagnosed 9.8 +/- 8 days after operation and was associated with 3 or less Ranson signs in all 21 study subjects. The following outcomes data differed between the two groups: duration of npo (9 +/- 6 days for subjects versus 3.9 +/- 2 days for controls, p < 0.001) and need for parenteral nutrition (13 subjects versus no controls, p < 0.00 1). Although there was a trend towards longer hospitalization in the subjects (16 +/- 12 days versus 11 +/- 8 days, p = 0.08), there was no difference in complication rates between the two groups. Sixteen subjects (76%) had no complications. Three developed severe complications, two of whom died of causes unrelated to pancreatitis. One developed a pseudocyst that resolved spontaneously. Cholelithiasis was a causative factor in 2 subjects; no cause was established in the remaining 19. There was no difference in operative details between the two groups. CONCLUSIONS: These data indicate that pancreatitis is a rare and self-limited complication of abdominal vascular surgery. Our findings suggest that pancreatitis is costly and inconvenient but rarely serious after abdominal vascular operations.

Watchful waiting in cases of small abdominal aortic aneurysms- appropriate for all patients?

OBJECTIVE: The purpose of this study was to determine the effect of patient compliance on a program of watchful waiting in cases of small abdominal aortic aneurysms and to document the proportion of patients who become prohibitive operative risks during follow-up. STUDY DESIGN: A retrospective review was conducted at a regional military veterans medical center. The subjects were 101 male military veterans with abdominal aortic aneurysms measuring less than 5 cm who did not have medical contraindications to operative repair. The main outcome measures were (1) the proportion of patients who missed three scheduled radiologic tests in a row despite written notifications mailed to their homes and (2) the proportion of compliant patients who had medical illnesses and became prohibitive operative risks during follow-up. RESULTS: During a follow-up (mean +/- SEM) of 34 +/- 2 months, 69 patients (69%) were fully compliant with the watchful waiting program and underwent a mean of 4.5 +/- 0.3 radiologic tests. There were no abdominal aortic aneurysm ruptures in this subgroup. Twenty-five patients (36%) had indications for abdominal aortic aneurysm repair, and 28 (41%) have not met the criteria for repair. Sixteen (23%) of the 69 compliant patients developed prohibitive medical risks during follow-up; eight (50%) of these 16 patients died, all of the causes unrelated to their abdominal aortic aneurysms. Thirty-two (32%) of the 101 study subjects were noncompliant with the watchful waiting program. Twenty-seven (84%) of the noncompliant patients did not keep any scheduled appointments, and five (16%) were lost after one or two examinations. Three of the noncompliant patients experienced documented abdominal aortic aneurysm rupture, and it is suspected in a fourth. Direct contact was made with 28 (88%) of these patients or their families; all acknowledged having received written notifications regarding their watchful waiting program tests and had decided not to continue with surveillance for a variety of socioeconomic reasons. Between the 69 compliant patients and the 32 noncompliant patients, there were no differences with respect to mean age (70 +/- 1 years vs 73 +/- 2 years), distance from home of record to the hospital (62 +/- 14 miles vs 73 +/- 23 miles), or abdominal aortic aneurysm size at initial detection (3.75 +/- 0.5 cm vs 3.8 +/- 0.5 cm). CONCLUSIONS: Watchful waiting programs are imperfect and highly reliant on the motivation levels and means of the individual patients. Watchful waiting is reasonable among compliant patients with abdominal aortic aneurysms, inasmuch as fewer than half will meet the criteria for intervention within a mean of 3 years. Approximately one fourth of these patients will have medical contraindications to abdominal aortic aneurysm repair during follow-up, and many of these will die of causes other than abdominal aortic aneurysm rupture. In our experience, one third of candidates for watchful waiting programs are unable to participate and are at risk of rupture. These patients need special attention so that the reasons for their noncompliance can be determined, and they may be candidates for earlier intervention.

The consequences of a failed femoropopliteal bypass grafting: comparison of saphenous vein and PTFE grafts.

OBJECTIVES: Although there are numerous reports comparing saphenous vein (SV) and polytetrafluoroethylene (PTFE) with respect to the patency rates for femoropopliteal bypass grafts, the clinical consequences of failed grafts are not as well described. This study compares the outcomes of failed SV and PTFE grafts with a specific emphasis on the degree of acute limb ischemia caused by graft occlusion. METHODS: Over a 6-year period, 718 infrainguinal revascularization procedures were performed, of which 189 were femoropopliteal bypass grafts (SV, 108; PTFE, 81). Society for Vascular Surgery/International Society for Cardiovascular Surgery (SVS/ISCVS) standardized runoff scores were calculated from preoperative arteriograms. Clinical categories of acute limb ischemia resulting from graft occlusion were graded according to SVS/ISCVS standards (I, viable; II, threatened; III, irreversible). Primary graft patency and limb salvage rates at 48 months were calculated according to the Kaplan-Meier method. RESULTS: Patients were well matched for age, sex, and comorbidities. Chronic critical ischemia was the operative indication in most cases (SV, 82%; PTFE, 80%; P =.85). Runoff scores and preoperative ankle-brachial index measurements were similar for the two groups (SV, 6.0 +/- 2.5 [SD] and 0.51 +/- 0.29; PTFE, 5.3 +/- 2.8 and 0.45 +/- 0.20; P =.06 and P =.12). The distal anastomosis was made below the knee in 60% of SV grafts and 16% of PTFE grafts (P <.001). Grade II ischemia was more likely to occur after occlusion of PTFE grafts (78%) than after occlusion of SV grafts (21%; P =.001). Emergency revascularization after graft occlusion was required for 28% of PTFE failures but only 3% of SV graft failures (P <.001). Primary graft patency at 48 months was 58% for SV grafts and 32% for PTFE grafts (P =.008). Limb salvage was achieved in 81% of SV grafts but only 56% of PTFE grafts (P =.019). CONCLUSIONS: Patients undergoing femoropopliteal bypass grafting with PTFE are at greater risk of ischemic complications from graft occlusion and more frequently require emergency limb revascularization as a result of graft occlusion than patients receiving SV grafts. Graft patency and limb salvage are superior with SV in comparison with PTFE in patients undergoing femoropopliteal bypass grafting.

Premature cardiovascular disease is common in relatives of patients with premature peripheral atherosclerosis.

BACKGROUND: Numerous clinical conditions have been proposed to explain the premature onset of symptomatic peripheral vascular disease (PVD) in young adults, but the role of genetic factors has not been defined. This study was performed to determine the prevalence of cardiovascular disease among family members of patients with premature PVD. METHODS: The prevalence of early cardiovascular events occurring in first-degree relatives of 90 subjects with premature PVD (onset < or =49 years) was determined. The prevalence of occult atherosclerosis was determined by duplex ultrasonography in a cohort of 20 asymptomatic siblings. Reference groups included first-degree relatives of 80 subjects with premature coronary artery disease (CAD) and first-degree relatives of 48 healthy subjects. RESULTS: Cardiovascular events occurred at age 55 years or younger in 28% of the parents of PVD subjects, in 23% of parents of CAD subjects, and in 7% of the parents of healthy controls (P<.001). Cardiovascular events occurred in 24% of siblings of PVD subjects, in 14% of siblings of CAD subjects, and in 7% of siblings of healthy controls (P<.001). Duplex ultrasonography detected early plaques in the lower extremity circulation of 10 (50%) of the asymptomatic siblings of PVD subjects. CONCLUSIONS: Early, symptomatic cardiovascular disease is more common in first-degree relatives of individuals with premature PVD than in relatives of healthy individuals or of probands with premature CAD. Occult vascular disease in the lower extremity is prevalent among asymptomatic siblings of probands with premature PVD. These observations indicate that susceptibility to premature PVD has a familial basis.

Prevention of venous thromboembolism.

Venous thromboembolism is a preventable cause of morbidity and death in hospitalized patients. In addition to administering correct and effective prophylaxis to the various treatment groups, therapy should be tailored to the individual based on the identification of baseline risk factors. No patient at significant risk for venous thrombosis should be left unprotected.

The progressive nature of peripheral arterial disease in young adults: a prospective analysis of white men referred to a vascular surgery service.

OBJECTIVE: The onset of symptomatic peripheral arterial disease at a young age (premature PAD) has been associated with rapid progression, bypass graft failure, and amputation. This study was performed to document the incidence of these complications and to determine the risk factors for poor outcome in patients with premature PAD. METHODS: This study was designed as a prospective longitudinal analysis, with patients who were ambulatory or hospitalized at a single vascular referral institution. The subjects were 51 white men with onset of PAD symptoms before the age of 45 years (mean age of onset, 41 +/- 0.5 years) and represented consecutive patients who were seen at the vascular surgery service during a 4-year period. Thirty of the study subjects (58%) were recruited during the first 2 years. The main outcome measures were number and type of lower extremity revascularization procedures or amputations that were necessitated during the follow-up period. RESULTS: During a mean follow-up period of 73 +/- 6 months, 15 patients (29%) had PAD that remained stable without interventions and 15 (29%) had PAD that remained stable for a mean of 76 +/- 13 months after a single intervention. Twenty-one patients (41%) required multiple operations or major amputations. In a comparison of the 30 PAD patients whose conditions were stable with or without a single intervention with the 21 PAD patients who required multiple interventions (REDO), there were no differences in smoking, hypertension, diabetes, or dyslipidemias. The REDO group had a younger mean age at the onset of symptoms (39 +/- 1 years vs 43 +/- 2 years; P <.001). At entry, the REDO patients had a higher prevalence of infrainguinal or multilevel disease (57% vs 20%; P =.03), a lower mean ankle brachial index (0. 44 +/- 0.04 vs 0.56 +/- 0.03; P =.02), and more frequent tissue loss (24% vs 0; P =.005). The REDO patients had a higher mean lipoprotein (a) level than did the patients with stable conditions (51 +/- 11 mg/dL vs 27 +/- 5 mg/dL; P =.03), but there were no significant differences in the mean plasma homocysteine levels (19 +/- 2 micromol/L vs 16 +/- 1 micromol/L) or in the proportion of patients with hypercoagulable states (33% vs 30%). The only predictive variables that were selected with stepwise logistic regression analysis were age at onset (P <.002; odds ratio, 1.4; 95% confidence interval, 1.11 to 1.81) and ankle brachial index of less than 0.5 (P <.008; odds ratio, 6.4; 95% confidence interval, 1.5 to 27.3). CONCLUSION: Although 60% of the white men with premature PAD who were referred to a vascular surgery service had conditions that appeared to remain stable, these data show that approximately 40% of the patients will require multiple interventions because of disease progression or bypass graft failure. Clinical indicators, not serum markers, are predictors of poor outcome in patients with premature PAD. The results of this study suggest that patients with onset of PAD before the age of 43 years who have objective evidence of advanced disease are predisposed to multiple interventions.

The North American Symptomatic Carotid Endarterectomy Trial : surgical results in 1415 patients.

BACKGROUND AND PURPOSE: This study reports the surgical results in those patients who underwent carotid endarterectomy in the North American Symptomatic Carotid Endarterectomy Trial (NASCET). METHODS: The rates of perioperative stroke and death at 30 days and the final assessment of stroke severity at 90 days were calculated. Regression modeling was used to identify variables that increased or decreased perioperative risk. Nonoutcome surgical complications were summarized. The durability of carotid endarterectomy was examined. RESULTS: In 1415 patients there were 92 perioperative outcome events, for an overall rate of 6.5%. At 30 days the results were as follows: death, 1.1%; disabling stroke, 1.8%; and nondisabling stroke, 3.7%. At 90 days, because of improvement in the neurological status of patients judged to have been disabled at 30 days, the results were as follows: death, 1.1%; disabling stroke, 0.9%; and nondisabling stroke, 4.5%. Thirty events occurred intraoperatively; 62 were delayed. Most strokes resulted from thromboembolism. Five baseline variables were predictive of increased surgical risk: hemispheric versus retinal transient ischemic attack as the qualifying event, left-sided procedure, contralateral carotid occlusion, ipsilateral ischemic lesion on CT scan, and irregular or ulcerated ipsilateral plaque. History of coronary artery disease with prior cardiac procedure was associated with reduced risk. The risk of perioperative wound complications was 9.3%, and that of cranial nerve injuries was 8.6%; most were of mild severity. At 8 years, the risk of disabling ipsilateral stroke was 5.7%, and that of any ipsilateral stroke was 17.1%. CONCLUSIONS: The overall rate of perioperative stroke and death was 6.5%, but the rate of permanently disabling stroke and death was only 2.0%. Other surgical complications were rarely clinically important. Carotid endarterectomy is a durable procedure.

Low-dose and high-dose acetylsalicylic acid for patients undergoing carotid endarterectomy: a randomised controlled trial. ASA and Carotid Endarterectomy (ACE) Trial Collaborators.

BACKGROUND: Endarterectomy benefits certain patients with carotid stenosis, but benefits are lessened by perioperative surgical risk. Acetylsalicylic acid lowers the risk of stroke in patients who have experienced transient ischaemic attack and stroke. We investigated appropriate doses and the role of acetylsalicylic acid in patients undergoing carotid endarterectomy. METHODS: In a randomised, double-blind, controlled trial, 2849 patients scheduled for endarterectomy were randomly assigned 81 mg (n=709), 325 mg (n=708), 650 mg (n=715), or 1300 mg (n=717) acetylsalicylic acid daily, started before surgery and continued for 3 months. We recorded occurrences of stroke, myocardial infarction, and death. We compared patients on the two higher doses of acetylsalicylic acid with patients on the two lower doses. FINDINGS: Surgery was cancelled in 45 patients, none were lost to follow-up by 30 days, and two were lost by 3 months. The combined rate of stroke, myocardial infarction, and death was lower in the low-dose groups than in the high-dose groups at 30 days (5.4 vs 7.0%, p=0.07) and at 3 months (6.2 vs 8.4%, p=0.03). In an efficacy analysis, which excluded patients taking 650 mg or more acetylsalicylic acid before randomisation, and patients randomised within 1 day of surgery, combined rates were 3.7% and 8.2%, respectively, at 30 days (p=0.002) and 4.2% and 10.0% at 3 months (p=0.0002). INTERPRETATION: The risk of stroke, myocardial infarction, and death within 30 days and 3 months of endarterectomy is lower for patients taking 81 mg or 325 mg acetylsalicylic acid daily than for those taking 650 mg or 1300 mg.

Complex aortofemoral prosthetic infections: the role of autogenous superficial femoropopliteal vein reconstruction.

BACKGROUND: With increasing experience, we have encountered patients with complex aortofemoral prosthetic infections in whom extra-anatomic bypass (EAB) is not an option. HYPOTHESIS: Autogenous superficial femoropopliteal vein (SFPV) aortic reconstruction provides a limb-saving and lifesaving alternative with acceptable morbidity and mortality. DESIGN: Retrospective review. SETTING: University-based county, private, and Veterans Affairs hospitals. PATIENTS: Seventeen patients with infected aortofemoral bypasses in whom conventional EAB was impossible because of infection of previously placed EAB, massive groin and/or thigh sepsis, or both. MAIN OUTCOME MEASURES: Morbidity and mortality. RESULTS: Multiple previous operations were common (mean, 4 per patient) and included EAB (n = 11), replacement aortofemoral bypass (n = 4), prosthetic femoropopliteal bypass (n = 7), and thoracobifemoral bypass (n = 1); all bypasses became infected. Overall, 11 patients had sepsis at the time of presentation. Of the patients with massive groin infection, 7 had extensive deep infections involving most of the proximal thighs or retroperitoneum, 4 had enterocutaneous fistulae, and 2 had necrotizing fasciitis of the lower abdomen and thigh. Polymicrobial infections were common (n = 9). Four patients (24%) died in the perioperative period, 8 (47%) suffered major complications, and 4 (24%) underwent major amputations. Mortality in this group of patients was 3 times that of all other patients undergoing autogenous SFPV aortic reconstruction for prosthetic infection (8%). Amputation rates were also increased (24% vs 6%). The mean+/-SD follow-up time is 23+/-21 months. All patients maintained patent SFPV reconstructions. CONCLUSIONS: In the setting of complex aortofemoral prosthetic infections, autogenous SFPV aortic reconstruction is a useful option for patients in whom EAB is impossible and limb loss and/or death would be inevitable without revascularization.

Venous morbidity after superficial femoral-popliteal vein harvest.

PURPOSE: The superficial femoral-popliteal vein (SFPV) is a reliable conduit for aortoiliac, infrainguinal, and venous reconstructions. In this prospective study, we characterized the anatomic and physiologic changes in SFPV harvest limbs and their relationship to the development of late venous complications. METHODS: Since 1990, we have studied 61 patients after harvest of 86 SFPVs at 6-month intervals with clinical examinations, lower-extremity venous duplex, and venous function tests. The CEAP system was used as a means of categorizing clinical changes. RESULTS: Mean (+/- SEM) follow-up was 37 +/- 3 months. Less than one third of harvest limbs had edema without skin changes (C3). No patient had major chronic venous changes (C4 to C6) or venous claudication. There were no significant differences in limb measurements between harvest and non-harvest limbs, except in a subgroup of patients with unilateral harvest in which there was a small but significant (P =.046) increase in harvest limb thigh and calf circumference, compared with the opposite non-harvest limb. These clinical results were not affected by the presence or absence of an intact greater saphenous vein (GSV). Large, direct collaterals (4 to 6 mm in diameter) between the popliteal vein stump and profunda femoris vein (PFV) were seen by means of duplex ultrasonography in 29 harvest limbs (34%). The remainder appeared to have smaller, less direct collaterals to the PFV. Mild venous reflux with rapid cuff deflation was present at the popliteal or posterior tibial vein in nine of 79 harvest limbs (11%). Six of these nine limbs (67%) with reflux were clinical class C3, compared with only 19 of the 70 limbs without reflux (27%; P =.02). Ambulatory venous pressure (AVP) with exercise was significantly increased in harvest limbs (60 +/- 4.7 mm Hg), compared with non-harvest limbs (47.8 +/- 5.2 mm Hg; P =.049). The AVP recovery time of harvest limbs (14.0 +/- 1.0 seconds) was reduced, compared with non-harvest limbs (23.5 +/- 4.5 seconds; P =.02). AVPs (exercise) remained stable or decreased in six of 10 harvest limbs measured serially. Venous refill time in harvest limbs (15.1 +/- 1.1 seconds) was shortened, compared with non-harvest limbs (22.3 +/- 2. 1 seconds)(P =.002). Venous outflow obstruction measured by means of plethysmography was present in 93% of harvest limbs, compared with 36% of non-harvest limbs (P =.001). CONCLUSION: SFPV harvest results in minimal mid-term to late-term lower-extremity venous morbidity despite outflow obstruction. The most likely mechanisms preserving clinical status include the low incidence of mild reflux, the presence of collateral venous channels, and the lack of progression in abnormal harvest limb physiology. The absence of the ipsilateral GSV does not adversely affect clinical outcome.

A randomized trial of intraoperative autotransfusion during aortic surgery.

PURPOSE: The net benefit of routine intraoperative autotransfusion (IAT) in patients undergoing elective infrarenal aortic surgery was studied. METHODS: One hundred patients undergoing abdominal aortic aneurysm (AAA) repair (n = 50) or aortofemoral bypass (AFB) for occlusive disease (n = 50) were randomized to IAT and control groups. This experience accounted for 58% of patients undergoing aortic surgery during the 16-month study period. RESULTS: IAT and control groups were balanced for preoperative demographics, disease (50:50 split of AFB:AAA in each group), and risk factors. There were no significant differences between patients randomized to IAT and control patients in estimated blood loss (EBL), allogeneic blood transfusion (units administered intraoperatively, postoperatively, and total), proportion of patients not receiving allogeneic blood (34% of patients randomized to IAT and 28% of control patients), postoperative hemoglobin/hematocrit levels, and complications. IAT did not reduce allogeneic blood transfusion among all patients undergoing aortic surgery nor in any subgroups that might be more likely to benefit, such as those undergoing AAA repair, those with 1000 mL or more EBL, and those receiving larger volumes of IAT-processed blood. CONCLUSION: We could find no net benefit of IAT in patients undergoing elective, infrarenal aortic surgery.

The role of imaging techniques in evaluating possible graft infections.

Imaging plays a central role in the management of graft infections. Most graft infections are clinically apparent, and imaging techniques are used primarily for diagnostic confirmation and operative planning. The accurate diagnosis of less overt graft infections requires a thorough understanding of the available imaging options. Late aortic graft infections (more than 3 months postoperative) are best evaluated initially by computed tomography (CT) or magnetic resonance (MR) scanning. CT findings consistent with a graft infection include ectopic gas, perigraft fluid, perigraft inflammatory changes, anastomotic pseudoaneurysm, and thickening of adjacent bowel. MRI offers the additional advantage of T2-weighted images to identify perigraft inflammation and minute quantities of perigraft fluid. Radionuclide scanning techniques such as 111indium-labeled WBC scans are highly sensitive but suffer from a relative lack of specificity. Duplex ultrasonography is best applied to the diagnosis of late infections of superficial grafts. Sonographic findings of a graft infection include perigraft fluid and pseudoaneurysms. The imaging of early postoperative grafts (less than 3 months) for infection is problematic because perigraft fluid and inflammatory changes persist for up to 3 months postoperatively. Suspected early graft infections often require operative exploration for diagnosis. A thorough understanding of the utility and limitations of imaging techniques will enable the clinician to develop a reasonable diagnostic algorithm that is appropriate for each case.