Fully automated tool to identify the aorta and compute flow using phase-contrast MRI: validation and application in a large population based study.

PURPOSE: To assess if fully automated localization of the aorta can be achieved using phase contrast (PC) MR images. MATERIALS AND METHODS: PC cardiac-gated MR images were obtained as part of a large population-based study. A fully automated process using the Hough transform was developed to localize the ascending aorta (AAo) and descending aorta (DAo). The study was designed to validate this technique by determining: (i) its performance in localizing the AAo and DAo; (ii) its accuracy in generating AAo flow volume and DAo flow volume; and (iii) its robustness on studies with pathological abnormalities or imaging artifacts. RESULTS: The algorithm was applied successfully on 1884 participants. In the randomly selected 50-study validation set, linear regression shows an excellent correlation between the automated (A) and manual (M) methods for AAo flow (r = 0.99) and DAo flow (r = 0.99). Bland-Altman difference analysis demonstrates strong agreement with minimal bias for: AAo flow (mean difference [A-M] = 0.47 ± 2.53 mL), and DAo flow (mean difference [A-M] = 1.74 ± 2.47 mL). CONCLUSION: A robust fully automated tool to localize the aorta and provide flow volume measurements on phase contrast MRI was validated on a large population-based study.

Instituting a culture of professionalism: the establishment of a center for professionalism and peer support.

BACKGROUND: There is growing recognition that an environment in which professionalism is not embraced, or where expectations of acceptable behaviors are not clear and enforced, can result in medical errors, adverse events, and unsafe work conditions. METHODS: The Center for Professionalism and Peer Support (CPPS) was created in 2008 at Brigham and Women's Hospital (BWH), Boston, to educate the hospital community regarding professionalism and manage unprofessional behavior. CPPS includes the professionalism initiative, a disclosure and apology process, peer and defendant support programs, and wellness programs. Leadership support, establishing behavioral expectations and assessments, emphasizing communication engagement and skills training, and creating a process for intake of professionalism concerns were all critical in developing and implementing an effective professionalism program. The process for assessing and responding to concerns includes management of professionalism concerns, an assessment process, and remediation and monitoring. RESULTS: Since 2005, thousands of physicians, scientists, nurse practitioners, and physician assistants have been trained in educational programs to support the identification, prevention, and management of unprofessional behavior. For January 1, 2010, through June 30, 2013, concerns were raised regarding 201 physicians/scientists and 8 health care teams. CONCLUSIONS: The results suggest that mandatory education sessions on professional development are successful in engaging physicians and scientists in discussing and participating in an enhanced professionalism culture, and that the processes for responding to professionalism concerns have been able to address, and most often alter, repetitive unprofessional behavior in a substantive and beneficial manner.

Effect of bar-code technology on the safety of medication administration.

BACKGROUND: Serious medication errors are common in hospitals and often occur during order transcription or administration of medication. To help prevent such errors, technology has been developed to verify medications by incorporating bar-code verification technology within an electronic medication-administration system (bar-code eMAR). METHODS: We conducted a before-and-after, quasi-experimental study in an academic medical center that was implementing the bar-code eMAR. We assessed rates of errors in order transcription and medication administration on units before and after implementation of the bar-code eMAR. Errors that involved early or late administration of medications were classified as timing errors and all others as nontiming errors. Two clinicians reviewed the errors to determine their potential to harm patients and classified those that could be harmful as potential adverse drug events. RESULTS: We observed 14,041 medication administrations and reviewed 3082 order transcriptions. Observers noted 776 nontiming errors in medication administration on units that did not use the bar-code eMAR (an 11.5% error rate) versus 495 such errors on units that did use it (a 6.8% error rate)--a 41.4% relative reduction in errors (P<0.001). The rate of potential adverse drug events (other than those associated with timing errors) fell from 3.1% without the use of the bar-code eMAR to 1.6% with its use, representing a 50.8% relative reduction (P<0.001). The rate of timing errors in medication administration fell by 27.3% (P<0.001), but the rate of potential adverse drug events associated with timing errors did not change significantly. Transcription errors occurred at a rate of 6.1% on units that did not use the bar-code eMAR but were completely eliminated on units that did use it. CONCLUSIONS: Use of the bar-code eMAR substantially reduced the rate of errors in order transcription and in medication administration as well as potential adverse drug events, although it did not eliminate such errors. Our data show that the bar-code eMAR is an important intervention to improve medication safety. (ClinicalTrials.gov number, NCT00243373.)

Automated quantification of white matter disease extent at 3 T: comparison with volumetric readings.

PURPOSE: To develop and validate an algorithm to automatically quantify white matter hyperintensity (WMH) volume. MATERIALS AND METHODS: Images acquired as part of the Dallas Heart Study, a multiethnic, population-based study of cardiovascular health, were used to develop and validate the algorithm. 3D magnetization prepared rapid acquisition gradient echo (MP-RAGE) and 2D fluid-attenuated inversion recovery (FLAIR) images were acquired from 2082 participants. Images from 161 participants (7.7% of the cohort) were used to set an intensity threshold to maximize the agreement between the algorithm and a qualitative rating made by a radiologist. The resulting algorithm was run on the entire cohort and outlier analyses were used to refine the WMH volume measurement. The refined, automatic WMH burden estimate was then compared to manual quantitative measurements of WMH volume in 28 participants distributed across the range of volumes seen in the entire cohort. RESULTS: The algorithm showed good agreement with the volumetric readings of a trained analyst: the Spearman's Rank Order Correlation coefficient was r = 0.87. Linear regression analysis showed a good correlation WMHml[automated] = 1.02 × WMHml[manual] - 0.48. Bland-Altman analysis showed a bias of 0.34 mL and a standard deviation of 2.8 mL over a range of 0.13 to 41 mL. CONCLUSION: We have developed an algorithm that automatically estimates the volume of WMH burden using an MP-RAGE and a FLAIR image. This provides a tool for evaluating the WMH burden of large populations to investigate the relationship between WMH burden and other health factors.

Cerebral atrophy after traumatic white matter injury: correlation with acute neuroimaging and outcome.

Traumatic brain injury (TBI) is a pathologically heterogeneous disease, including injury to both neuronal cell bodies and axonal processes. Global atrophy of both gray and white matter is common after TBI. This study was designed to determine the relationship between neuroimaging markers of acute diffuse axonal injury (DAI) and cerebral atrophy months later. We performed high-resolution magnetic resonance imaging (MRI) at 3 Tesla (T) in 20 patients who suffered non-penetrating TBI, during the acute (within 1 month after the injury) and chronic stage (at least 6 months after the injury). Volume of abnormal fluid-attenuated inversion-recovery (FLAIR) signal seen in white matter in both acute and follow-up scans was quantified. White and gray matter volumes were also quantified. Functional outcome was measured using the Functional Status Examination (FSE) at the time of the chronic scan. Change in brain volumes, including whole brain volume (WBV), white matter volume (WMV), and gray matter volume (GMV), correlates significantly with acute DAI volume (r = -0.69, -0.59, -0.58, respectively; p <0.01 for all). Volume of acute FLAIR hyperintensities correlates with volume of decreased FLAIR signal in the follow-up scans (r = -0.86, p < 0.001). FSE performance correlates with acute hyperintensity volume and chronic cerebral atrophy (r = 0.53, p = 0.02; r = -0.45, p = 0.03, respectively). Acute axonal lesions measured by FLAIR imaging are strongly predictive of post-traumatic cerebral atrophy. Our findings suggest that axonal pathology measured as white matter lesions following TBI can be identified using MRI, and may be a useful measure for DAI-directed therapies.

Computed tomography in the diagnosis of occult open-globe injuries.

PURPOSE: To determine the radiographic signs present on computed tomography (CT) most suggestive of occult open-globe injury. DESIGN: Retrospective chart review. PARTICIPANTS: Forty-eight eyes (of 46 patients), 34 of which were found to have an occult open-globe injury on surgical exploration. METHODS: A retrospective chart review of all eyes of patients 18 years or older undergoing surgical exploration to rule out occult open-globe injury after CT examination at Parkland Memorial Hospital between October, 1998, and September, 2003, was conducted. Patients with obvious corneal or corneoscleral lacerations or with uveal prolapse were excluded. The CT films were obtained and independently reviewed by 3 masked observers (2 neuroradiologists and 1 ophthalmologist). MAIN OUTCOME MEASURES: Presence of occult open-globe injury with respect to radiographic globe and orbital findings. RESULTS: The sensitivity of CT for determining occult open-globe injury varied from 56% to 68% between the observers, specificity ranged from 79% to 100%, positive predictive value ranged from 86% to 100%, and negative predictive value ranged from 42% to 50%. Open-globe injuries averaged more CT findings per patient compared with intact globes (P = 0.047). Statistically significant CT findings for occult open-globe injury included any change in globe contour (P = 0.001), obvious volume loss (P = 0.003), an absent or dislocated lens (P = 0.048), vitreous hemorrhage (P = 0.003), and retinal detachment (P = 0.044). Additionally, moderate to severe change in globe contour, obvious volume loss, total vitreous hemorrhage, and absence of lens were seen only in eyes with occult rupture. CONCLUSIONS: Although CT scanning may provide valuable information in patients in whom an occult open-globe injury is suspected, its sensitivity and specificity are inadequate to be relied on fully, and such patients generally should be taken to the operating room for formal surgical evaluation. Significant changes in globe contour or obvious volume loss are strong predictors of globe rupture, and any vitreous hemorrhage should be a concern for occult injury.

Magnetic resonance imaging of diffuse axonal injury: quantitative assessment of white matter lesion volume.

Diffuse axonal injury (DAI) is a common mechanism of traumatic brain injury (TBI) for which there is no well-accepted anatomic measures of injury severity. The present study aims to quantitatively assess DAI by measuring white matter lesion volume visible in fluid-attenuated inversion recovery (FLAIR) weighted images and to determine whether higher lesion volumes are associated with unfavorable functional outcome 6 months after injury. Twenty-four patients who experienced moderate to severe TBI without extra-axial or major cortical contusions were included in this study. Lesion volume was assessed by quantifying areas of hyperintensities in the white matter utilizing digitized FLAIR images. Two independent raters processed the magnetic resonance (MR) images and determined the total DAI volume. Functional outcome was assessed at 6 months after injury using the Glasgow Outcome Scale-Extended (GOSE). Interclass correlation analyses showed very high interrater reliability for each measure between the two raters (Interclass Correlation Coefficient = 0.95, p

Medication dispensing errors and potential adverse drug events before and after implementing bar code technology in the pharmacy.

BACKGROUND: Many dispensing errors made in hospital pharmacies can harm patients. Some hospitals are investing in bar code technology to reduce these errors, but data about its efficacy are limited. OBJECTIVE: To evaluate whether implementation of bar code technology reduced dispensing errors and potential adverse drug events (ADEs). DESIGN: Before-and-after study using direct observations. SETTING: Hospital pharmacy at a 735-bed tertiary care academic medical center. INTERVENTION: A bar code-assisted dispensing system was implemented in 3 configurations. In 2 configurations, all doses were scanned once during the dispensing process. In the third configuration, only 1 dose was scanned if several doses of the same medication were being dispensed. MEASUREMENTS: Target dispensing errors, defined as dispensing errors that bar code technology was designed to address, and target potential ADEs, defined as target dispensing errors that can harm patients. RESULTS: In the pre- and post-bar code implementation periods, the authors observed 115,164 and 253,984 dispensed medication doses, respectively. Overall, the rates of target potential ADEs and all potential ADEs decreased by 74% and 63%, respectively. Of the 3 configurations of bar code technology studied, the 2 configurations that required staff to scan all doses had a 93% to 96% relative reduction in the incidence of target dispensing errors (P < 0.001) and 86% to 97% relative reduction in the incidence of potential ADEs (P < 0.001). However, the configuration that did not require scanning of every dose had only a 60% relative reduction in the incidence of target dispensing errors (P < 0.001) and an increased (by 2.4-fold) incidence of target potential ADEs (P = 0.014). There were several potentially life-threatening ADEs involving intravenous dopamine and intravenous heparin in that configuration. LIMITATIONS: The authors used surrogate outcomes; did not mask assessors to the purpose of study; and excluded the controlled substance fill process (a process with low error rates at baseline) from the study, which may bias the combined decrease in error rates toward a larger magnitude. CONCLUSIONS: The overall rates of dispensing errors and potential ADEs substantially decreased after implementing bar code technology. However, the technology should be configured to scan every dose during the dispensing process.

Closing the loop: follow-up and feedback in a patient safety program.

BACKGROUND: As health care organizations establish patient safety agendas, attention has focused on creating less cumbersome systems for reporting errors. However, experience at Brigham and Women's Hospital (Boston) suggests that more emphasis needs to be placed on what happens after a report is submitted. FOLLOW-UP AND FEEDBACK: Follow-up includes prioritizing opportunities and actions, assigning responsibility and accountability, and implementing the action plan. Feedback entails (1) follow-up to those who report issues and (2) communication to the hospital staff and clinicians about events and actions taken. Responsibility and accountability for improvements need to be assigned by senior administration to hospital leaders who can effect the needed changes. Hospital leaders, not just the members of the patient safety team, must own these changes or improvements. Events that require follow-up action are brought to the attention of risk management and the patient safety team through several mechanisms, including voluntary reporting of adverse events through a computerized safety reporting system, root cause analyses, and Patient Safety Leadership WalkRounds. DISCUSSION: Developing and maintaining a systematic method for feedback represents more of a challenge than the completion of any single recommended action item. However, it is the feedback to the reporter that perpetuates the influx of information and closes the loop. Developing the information-tracking database has made providing feedback easier and more reliable but significant effort is required to keep the database current.

The utility of preoperative diffusion tensor imaging in the surgical management of brainstem cavernous malformations.

OBJECT: Resection of brainstem cavernous malformations (BSCMs) may reduce the risk of stepwise neurological deterioration secondary to hemorrhage, but the morbidity of surgery remains high. Diffusion tensor imaging (DTI) and diffusion tensor tractography (DTT) are neuroimaging techniques that may assist in the complex surgical planning necessary for these lesions. The authors evaluate the utility of preoperative DTI and DTT in the surgical management of BSCMs and their correlation with functional outcome. METHODS: A retrospective review was conducted to identify patients who underwent resection of a BSCM between 2007 and 2012. All patients had preoperative DTI/DTT studies and a minimum of 6 months of clinical and radiographic follow-up. Five major fiber tracts were evaluated preoperatively using the DTI/DTT protocol: 1) corticospinal tract, 2) medial lemniscus and medial longitudinal fasciculus, 3) inferior cerebellar peduncle, 4) middle cerebellar peduncle, and 5) superior cerebellar peduncle. Scores were applied according to the degree of distortion seen, and the sum of scores was used for analysis. Functional outcomes were measured at hospital admission, discharge, and last clinic visit using modified Rankin Scale (mRS) scores. RESULTS: Eleven patients who underwent resection of a BSCM and preoperative DTI were identified. The mean age at presentation was 49 years, with a male-to-female ratio of 1.75:1. Cranial nerve deficit was the most common presenting symptom (81.8%), followed by cerebellar signs or gait/balance difficulties (54.5%) and hemibody anesthesia (27.2%). The majority of the lesions were located within the pons (54.5%). The mean diameter and estimated volume of lesions were 1.21 cm and 1.93 cm(3), respectively. Using DTI and DTT, 9 patients (82%) were found to have involvement of 2 or more major fiber tracts; the corticospinal tract and medial lemniscus/medial longitudinal fasciculus were the most commonly affected. In 2 patients with BSCMs without pial presentation, DTI/DTT findings were important in the selection of the surgical approach. In 2 other patients, the results from preoperative DTI/DTT were important for selection of brainstem entry zones. All 11 patients underwent gross-total resection of their BSCMs. After a mean postoperative follow-up duration of 32.04 months, all 11 patients had excellent or good outcome (mRS Score 0-3) at the time of last outpatient clinic evaluation. DTI score did not correlate with long-term outcome. CONCLUSIONS: Preoperative DTI and DTT should be considered in the resection of symptomatic BSCMs. These imaging studies may influence the selection of surgical approach or brainstem entry zones, especially in deep-seated lesions without pial or ependymal presentation. DTI/DTT findings may allow for more aggressive management of lesions previously considered surgically inaccessible. Preoperative DTI/DTT changes do not appear to correlate with functional postoperative outcome in long-term follow-up.

Association of 3.0-T brain magnetic resonance imaging biomarkers with cognitive function in the Dallas Heart Study.

IMPORTANCE: Understanding the relationships between age-related changes in brain structure and cognitive function has been limited by inconsistent methods for assessing brain imaging, small sample sizes, and racially/ethnically homogeneous cohorts with biased selection based on risk factors. These limitations have prevented the generalizability of results from brain morphology studies. OBJECTIVE: To determine the association of 3.0-T structural brain magnetic resonance (MR) imaging measurements with cognitive function in the multiracial/multiethnic, population-based Dallas Heart Study. DESIGN, SETTING, AND PARTICIPANTS: Whole-brain, 2-dimensional, fluid-attenuated inversion recovery and 3-dimensional, magnetization-prepared, rapid acquisition with gradient echo MR imaging at 3.0 T was performed in 1645 Dallas Heart Study participants (mean [SD] age, 49.9 [10.5] years; age range, 19-85 years) who received both brain MR imaging and cognitive screening with the Montreal Cognitive Assessment between September 18, 2007, and December 28, 2009. Measurements were obtained for white matter hyperintensity volume, total brain volume, gray matter volume, white matter volume, cerebrospinal fluid volume, and hippocampal volume. Linear regression and a best predictive model were developed to determine the association of MR imaging biomarkers with the Montreal Cognitive Assessment total score and domain-specific questions. MAIN OUTCOMES AND MEASURES: High-resolution anatomical MR imaging was used to quantify brain volumes. Scores on the screening Montreal Cognitive Assessment were used for cognitive assessment in participants. RESULTS: After adjustment for demographic variables, total brain volume (P < .0001, standardized estimate [SE] = .1069), gray matter volume (P < .0001, SE = .1156), white matter volume (P = .008, SE = .0687), cerebrospinal fluid volume (P = .012, SE = -.0667), and hippocampal volume (P < .0001) were significantly associated with cognitive performance. A best predictive model identified gray matter volume (P < .001, SE = .0021), cerebrospinal fluid volume (P = .01, SE = .0024), and hippocampal volume (P = .004, SE = .1017) as 3 brain MR imaging biomarkers significantly associated with the Montreal Cognitive Assessment total score. Questions specific to the visuospatial domain were associated with the most brain MR imaging biomarkers (total brain volume, gray matter volume, white matter volume, cerebrospinal fluid volume, and hippocampal volume), while questions specific to the orientation domain were associated with the least brain MR imaging biomarkers (only hippocampal volume). CONCLUSIONS AND RELEVANCE: Brain MR imaging volumes, including total brain volume, gray matter volume, cerebrospinal fluid volume, and hippocampal volume, were independently associated with cognitive function and may be important early biomarkers of risk for cognitive insult in a young multiracial/multiethnic population. A best predictive model indicated that a combination of multiple neuroimaging biomarkers may be more effective than a single brain MR imaging volume measurement.

Transaortic endarterectomy for primary mesenteric revascularization.

The optimal approach to revascularization for chronic mesenteric ischemia has not been firmly established during the past three decades. The present study was undertaken to evaluate the safety and results of primary mesenteric revascularization for chronic mesenteric ischemia by transaortic endarterectomy. A descriptive retrospective analysis of 14 patients who underwent trap-door transaortic endarterectomy for primary mesenteric revascularization was performed. Clinical presentations of the patients included abdominal pain (n=13) and weight loss (n=7). All patients underwent preoperative aortography and subsequent elective reconstruction. Demographic features, perioperative, and long-term outcomes were analyzed. The study population consisted of 12 females and two males with a mean age of 67 years. The mean operative duration was 3 hours with an ischemic time of 33 minutes. The initial success rate of mesenteric revascularization was 93%. One early graft failure was salvaged with urgent embolectomy without bowel resection. There was no hospital mortality, but the overall postoperative morbidity rate was 50% (n=7). Thirteen patients (93%) were discharged within 2 weeks. Late recurrent ischemia and intestinal infarction developed in one patient, requiring emergency bowel resection. Sustained relief of symptoms was achieved in 13 of 14 patients (93%). The overall survival rates were 85% +/-10.0% and 77% +/-11.7% at 1 and 3 years, respectively. Transaortic endarterectomy is a safe and effective technique for elective primary mesenteric revascularization for patients with chronic mesenteric ischemia. This approach allows simultaneous revascularization of multiple visceral arteries and achieves durable relief of symptoms.

Validation of non-rigid registration between functional and anatomical magnetic resonance brain images.

This paper presents a set of validation procedures for nonrigid registration of functional EPI to anatomical MRI brain images. Although various registration techniques have been developed and validated for high-resolution anatomical MRI images, due to a lack of quantitative and qualitative validation procedures, the use of nonrigid registration between functional EPI and anatomical MRI images has not yet been deployed in neuroimaging studies. In this paper, the performance of a robust formulation of a nonrigid registration technique is evaluated in a quantitative manner based on simulated data and is further evaluated in a quantitative and qualitative manner based on in vivo data as compared to the commonly used rigid and affine registration techniques in the neuroimaging software packages. The nonrigid registration technique is formulated as a second-order constrained optimization problem using a free-form deformation model and mutual information similarity measure. Bound constraints, resolution level and cross-validation issues have been discussed to show the degree of accuracy and effectiveness of the nonrigid registration technique. The analyses performed reveal that the nonrigid approach provides a more accurate registration, in particular when the functional regions of interest lie in regions distorted by susceptibility artifacts.

Diffusion tensor tractography of traumatic diffuse axonal injury.

BACKGROUND: Diffuse axonal injury is a common consequence of traumatic brain injury that frequently involves the parasagittal white matter, corpus callosum, and brainstem. OBJECTIVE: To examine the potential of diffusion tensor tractography in detecting diffuse axonal injury at the acute stage of injury and predicting long-term functional outcome. DESIGN: Tract-derived fiber variables were analyzed to distinguish patients from control subjects and to determine their relationship to outcome. SETTING: Inpatient traumatic brain injury unit. PATIENTS: From 2005 to 2006, magnetic resonance images were acquired in 12 patients approximately 7 days after injury and in 12 age- and sex-matched controls. MAIN OUTCOME MEASURES: Six fiber variables of the corpus callosum, fornix, and peduncular projections were obtained. Glasgow Outcome Scale-Extended scores were assessed approximately 9 months after injury in 11 of the 12 patients. RESULTS: At least 1 fiber variable of each region showed diffuse axonal injury-associated alterations. At least 1 fiber variable of the anterior body and splenium of the corpus callosum correlated significantly with the Glasgow Outcome Scale-Extended scores. The predicted outcome scores correlated significantly with actual scores in a mixed-effects model. CONCLUSION: Diffusion tensor tractography-based quantitative analysis at the acute stage of injury has the potential to serve as a valuable biomarker of diffuse axonal injury and predict long-term outcome.

Specialized staff and equipment for weight loss surgery patients: best practice guidelines.

OBJECTIVE: To provide evidence-based guidelines on the specialized personnel, equipment, and physical plant required for safe and effective care of severely obese weight loss surgery (WLS) patients. RESEARCH METHODS AND PROCEDURES: We examined MEDLINE (Ovid and PubMed) and the Cumulative Index of Nursing and Allied Health Literature for articles on facilities resources for care of WLS patients published in English between January 1980 and March 2004. We queried several web sites for appropriate references; these included the Agency for Healthcare Research and Quality and the American College of Surgeons. The majority of reference material was descriptive and not specific to facilities resources for WLS patients. We identified a substantial body of literature on the general subject of patient safety; three of these articles were used to develop recommendations on the use of technology for medical error reduction. All other recommendations are based on 11 expert opinion reports. RESULTS: We recommended adequate training and credentialing for all medical staff; dedicated support and administrative personnel; and specialized interventional, diagnostic, operating room, and transport equipment. We specified needed adaptations to the physical plant and developed evidence-based guidelines for medical error reduction and systems improvements. DISCUSSION: Specialized resources and dedicated staff are needed to protect the health of WLS surgery patients and staff. Adaptations include preoperative preparation for safe means of patient transport; techniques of anesthesia and intraoperative exposure; provisions for postoperative recovery; and measures to assure postoperative patient safety, hygiene, and comfort.

Comparative analysis of autogenous infrainguinal bypass grafts in African Americans and Caucasians: the association of race with graft function and limb salvage.

OBJECTIVE: African Americans (AAs) are at risk for developing diabetes mellitus and atherosclerosis. Whether race influences the results of infrainguinal arterial reconstruction is unclear. The purpose of this study was to compare the results of autogenous infrainguinal bypasses in AAs and Caucasians to determine the association of race with graft function and limb salvage. METHODS: This was a retrospective, comparative cohort study of AA and Caucasian patients who had undergone autogenous infrainguinal bypass surgery. Only single-limb bypasses in each patient cohort were considered in this analysis. In patients who had undergone bilateral lower limb bypasses, the first limb bypass was chosen as the index bypass procedure. RESULTS: From January 1985 to December 2003, 1459 autogenous infrainguinal bypasses were performed in 1459 patients for lower limb ischemia. Within this group, 89 AA patients/vein grafts formed the study cohort. The control group comprised 1370 Caucasian patients/vein grafts. Compared with the Caucasian cohort, AA patients were significantly younger (median age, 65 vs 70 years, respectively; P = .001) and predominantly female (57% vs 41%, respectively; P = .002). AA patients also had a higher prevalence of diabetes mellitus, hypertension, cerebrovascular disease, congestive heart failure, and dialysis-dependent renal failure. More AA than Caucasian patients presented with gangrene (34% vs 16%, respectively; P = .001), and more underwent bypass surgery for limb salvage indications (91% vs 81%, respectively; P = .01). The venous conduit used was predominantly the greater saphenous vein (AA, 83%; Caucasian, 85%), and the site of distal anastomosis was at the tibial/pedal level in 67% of AA and 61% of Caucasian patients. Overall morbidity (AA, 28%; Caucasian, 23%) and 30-day mortality (AA, 3%; Caucasian, 3%) were similar. Thirty-day graft failure was significantly greater in AAs than Caucasians (12% vs 5%, respectively; P = .003). The overall 5-year primary graft patency (+/-SE) was significantly worse in AA patients (AA, 52% +/- 6%; Caucasian, 67% +/- 2%; P = .009). The 5-year limb salvage rate (+/-SE) was also significantly worse in AA patients (AA, 81% +/- 5%; Caucasian, 90% +/- 1%; P = .04). With the Cox proportional hazard model, significant risk factors associated with primary graft failure were AA race, age younger than 65 years, female sex, secondary reconstructions, tibial bypasses, and critical limb ischemia. Significant risk factors associated with limb loss were age younger than 65 years, female sex, absence of coronary disease, presence of critical limb ischemia, and secondary reconstructions. CONCLUSIONS: Autogenous infrainguinal bypass surgery in AAs is associated with poorer primary graft patency and limb salvage rates compared with those of Caucasians. This may partially account for the higher rate of limb loss in AA patients with peripheral arterial occlusive disease.

The impact of patient age and aortic size on the results of aortobifemoral bypass grafting.

OBJECTIVES: On the basis of the widespread belief that aortobifemoral bypass (ABF) represents the optimal mode of revascularization for patients with diffuse aortoiliac disease, vascular surgeons are often aggressive about its application in young adults. We undertook this retrospective evaluation of ABFs performed from 1980 to 1999 to determine whether the results justify this approach. Patients of less than 50 years of age (n = 45) were compared with those aged 50 to 59 years (n = 93) and those aged more than 60 years (n = 146). RESULTS: Younger patients were more likely to undergo operation for claudication than were older patients (72% versus 59% and 55%; P <.04). Younger patients were significantly more likely to be smokers (87%) but less likely to have diabetes, hypertension, or cerebrovascular disease. Bypasses were constructed in an end-to-end fashion in 71.1% of patients of less than 50 years versus 68.8% and 71.2% of older patients (P = not significant). The mean diameter of aortic grafts was significantly smaller in younger patients (14.6 mm) than in older patients (15.6 mm and 15.5 mm; P <.01). The need for a subsequent infrainguinal reconstruction was highest in the youngest patients (24% versus 17% and 7%; P <.01). Surgical mortality rates were low in all groups (0%, 1%, and 2.0% for increasing age groups; P = not significant). Five-year primary and secondary patency rates increased significantly with each increase in age interval: 5-year primary patency rate: less than 50 years, 66% +/- 8%; 50 to 59 years, 87% +/- 5%; more than 60 years, 96% +/-2% (P <.05 for all comparisons). Five-year secondary patency rates were: less than 50 years, 79% +/- 7%; 50 to 59 years, 91% +/- 4%; more than 60 years, 98% +/- 2% (P <.05 for all comparisons). Five-year survival rate was comparable in all three groups: less than 50 years, 93% +/- 5%; 50 to 59 years, 92% +/- 4%; more than 60 years, 87% +/- 4% (P = not significant). CONCLUSION: Increased virulence of aortic disease, smaller aortic size, and more progressive infrainguinal disease may all negatively impact the results of ABF in younger patients. Although 5-year results are acceptable, increased caution is warranted in the routine application of ABF in young patients without limb-threatening ischemia.