Decision aids for patients with carotid stenosis.

BACKGROUND: Shared decision-making tools have been underused by clinicians in real-world practice. Changes to the National Coverage Determination by Medicare for carotid stenting greatly expand the coverage for patients, but simultaneously require a shared decision-making interaction that involves the use of a validated tool. Accordingly, our objective was to evaluate the currently available decision aids for carotid stenosis. METHODS: We conducted a review of the literature for published work on decision aids for the treatment of carotid disease. RESULTS: Four publications met inclusion criteria. We found the format of the decision aid impacted patient comprehension and decision making, although patient characteristics also played a role in the therapeutic decisions made. Notably, none of the available decision aids included the widely adopted transcarotid artery revascularization as an option. CONCLUSIONS: Further work is needed in the development of a widespread validated decision aid instrument for patients with carotid stenosis.

Most preoperative stress tests fail to comply with practice guideline indications and do not reduce cardiac events.

BACKGROUND: There is wide variation in stress test utilization before major vascular surgery and adherence to practice guidelines is unclear. We defined rates of stress test compliance at our institution and led a quality improvement initiative to improve compliance with American Heart Association (ACC/AHA) guidelines. METHODS: We implemented a stress testing order set in the electronic medical record at one tertiary hospital. We reviewed all patients who underwent elective, major vascular surgery in the 6 months before (Jan 1, 2022 - Jul 1, 2022) and 6 months after (Aug 1, 2022 - Jan 31, 2023) implementation. We studied stress test guideline compliance, changes in medical or surgical management, and major adverse cardiac events (MACE). RESULTS: Before order set implementation, 37/122 patients (30%) underwent stress testing within the past year (29 specifically ordered preoperatively) with 66% (19/29) guideline compliance. After order set implementation, 50/173 patients (29%) underwent stress testing within the past year (41 specifically ordered preoperatively) with 80% (33/41) guideline compliance. In the pre- and postimplementation cohorts, stress testing led to a cardiovascular medication change or preoperative coronary revascularization in 24% (7/29) and 27% (11/41) of patients, and a staged surgery or less invasive anesthetic strategy in 14% (4/29) and 4.9% (2/41) of patients, respectively. All unindicated stress tests were surgeon-ordered and none led to a change in management. There was no change in MACE after order set implementation. CONCLUSIONS: Electronic medical record-based guidance of perioperative stress testing led to a slight decrease in overall stress testing and an increase in guideline-compliant testing. Our study highlights a need for improved preoperative cardiovascular risk assessment prior to major vascular surgery, which may eliminate unnecessary testing and more effectively guide perioperative decision-making.

Readmission After Lower Extremity Bypass Following Discharge to a Rehabilitation or Nursing Facility.

INTRODUCTION: Hospital readmission after lower extremity arterial bypass (LEB) is common. Patients are often discharged to a facility after LEB as a bridge to home. Our objective was to define the association between discharge to a facility and readmission after LEB. METHODS: We used the Vascular Quality Initiative to study patients who underwent LEB from 2017 to 2022. The primary exposure was discharge location. The primary outcome was 30-d hospital readmission. RESULTS: We included 6076 patients across 147 centers. The overall 30-d readmission rate was 18%. Readmission occurred among 15% of patients discharged home, 22% of patients discharged to a rehabilitation facility, and 25% of patients discharged to a nursing home. After controlling for patient and procedural factors, there was no significant association between discharge location and 30-d readmission (rehabilitation versus home odds ratio: 1.06, 95% confidence interval: 0.87-1.29; nursing facility versus home odds ratio: 1.21, 95% confidence interval: 0.99-1.47). Female sex, end-stage renal disease, diabetes, heart failure, pulmonary disease, smoking, preoperative functional impairment, tibial bypass target, critical limb threatening or acute ischemia, and postoperative complications including surgical site infection, change in renal function and graft thrombosis were associated with an increased likelihood of readmission. CONCLUSIONS: Patients discharged home after LEB experienced a similar likelihood of readmission as those discharged to a facility. While discharge to a facility may aid in care transitions, it did not appear to lead to reduced 30-d readmissions. The recommended discharge location should be predicated on patient care needs and not as a perceived mechanism to reduce readmissions.

Center volume is associated with diminished failure to rescue and improved outcomes following elective open abdominal aortic aneurysm repair.

OBJECTIVE: Conflicting annual procedure volumes have been endorsed among different watchdog groups and professional societies, obscuring credentialing paradigms. There has been ample focus on surgeon volume to date but less attention on the effect of center volume. Specifically, whether center volume might be a better proxy for high-quality care. In the present study, we aimed to measure the association of center volume on open abdominal aortic aneurysm (AAA) repair (OAR) outcomes and failure to rescue (FTR). METHODS: All elective OARs (2003-2020) in the Society for Vascular Surgery Vascular Quality Initiative were reviewed (n = 9791). FTR was defined as in-hospital death after the occurrence of a complication (ie, cardiac, stroke, pulmonary, renal, colonic ischemia, return to the operating room for bleeding). The annual center volume for 218 hospitals was calculated, and the volume quartiles (quartile 1 [Q1], ≤3 procedures/y; quartile 2 [Q2], 4-6 procedures/y; quartile 3 [Q3], 7-10 procedures/y; quartile 4 [Q4], >10 procedures/y) were derived for comparison. Logistic regression was used to estimate the effect of center volume and determine the predictors of FTR. RESULTS: The center volume quartiles and incidence of FTR varied significantly (Q4, 2.5% vs Q1 and Q2, 4.9%; P < .0001; overall FTR, 3.1% [n = 302]). The patients were demographically similar among the quartiles. High-volume centers had used epidural anesthesia more often (Q4, 53%; vs Q1, 31%; P < .0001) but were less likely to use thrombectomy (Q4, 5%; vs Q1, 10%; P < .0001) or any concomitant procedure (Q4, 19%; vs Q1, 22%; P = .05). High-volume centers had had lower rates of pulmonary, renal, and overall complications (pulmonary: Q4, 7%; vs Q1-Q2, 8%-11%; renal: Q4, 16%; vs Q1-2, 19%-21%; P < .0001; overall mean number of complications: Q4, 0.46; vs Q1, 0.52; P = .0008). The crude 30-day and 1-year mortality rates were reduced at the higher volume centers (30 days: Q4, 3%; vs Q1-Q2, 6%; P < .0001; 1 year: Q4, 7%; vs Q1-Q2, 10%-11%; P < .0001). A strong inverse relationship between center volume and FTR was identified (P < .0001). In the adjusted analysis, OARs performed in high-volume centers (Q4 vs Q1) had a 50% risk reduction in FTR (odds ratio [OR], 0.48; 95% confidence interval [CI], 0.3-0.8; P = .004). Among the complications, a return to the operating room for bleeding was most likely to result in FTR (OR, 11.8; 95% CI, 4.3-33; P < .0001). A 24-fold increased risk of FTR was found for patients experiencing three or more complications vs one complication (OR, 24; 95% CI, 17-35; P < .0001). CONCLUSIONS: A greater center volume was strongly associated with significantly diminished FTR, reduced complications, and need for surgical adjuncts during OAR. These findings highlight the utility of center volume as an effective proxy to ensure high-quality aneurysm care.

The financial implications of cardiac stress testing prior to abdominal aortic aneurysm repair.

BACKGROUND: The utilization and cost-effectiveness of stress testing before abdominal aortic aneurysm (AAA) repair remains insufficiently studied. We examined the variation and financial implications of stress testing, and their association with major adverse cardiovascular events (MACE). METHODS: We studied patients who underwent elective endovascular (EVAR) or open AAA repair (OAR) at Vascular Quality Initiative centers from 2015 to 2019. We grouped centers into quintiles of preoperative stress testing frequency. We calculated the risk of postoperative MACE, a composite of in-hospital myocardial infarction, heart failure, or death, for each center-quintile. We obtained charges for stress tests locally and applied these to the cohort to estimate charges per 1000 patients. RESULTS: We studied 32,459 patients (EVAR: 27,978; OAR: 4481; 283 centers). Stress test utilization varied across quintiles from 13.0% to 68.6% (median: 36.8%) before EVAR and 15.9% to 85.0% (median: 59.4%) before OAR. The risk of MACE was 1.4% after EVAR and 10.2% after OAR. There was a trend towards more common MACE after EVAR among centers with higher utilization of stress testing: 0.9% among centers in the lowest quintile, versus 1.7% in the highest quintile (p-trend = 0.068). There was no association between MACE and stress testing frequency for OAR (p-trend = 0.223). The estimated financial charges for stress testing before EVAR ranged from $125,806 per 1000 patients at 1st-quintile centers, to $665,975 at 5th-quintile centers. Charges before OAR ranged from $153,861 at 1st-quintile centers, to $825,473 at 5th-quintile centers. CONCLUSION: Stress test use before AAA repair is highly variable and associated with substantial cost, with an unclear association with postoperative MACE. This highlights the need for improved stress testing paradigms prior to surgery.

Comparison of Aortobifemoral Bypass to Aortoiliac Stenting with Bifurcation Reconstruction for TASC II D Aortoiliac Occlusive Disease.

BACKGROUND: Long-segment stenting of the infrarenal aorta and bilateral iliac arteries, with or without femoral endarterectomy for diffuse disease, has been adopted for treatment of severe aortoiliac occlusive disease (AIOD). The objective of this study was to compare outcomes of this reconstruction, termed aortoiliac stenting with bifurcation reconstruction (AISBR), to aortobifemoral bypass (ABF) in patients with comparable TASC II D lesions. METHODS: This is a single-center, retrospective review of patients treated with ABF or AISBR for comparable TASC II D lesions between 2010 and 2018. ABF patients were included only if they were deemed anatomic candidates also for AISBR after review of preoperative imaging. Patients treated for acute limb ischemia and bypass graft infection were excluded. Statistics included Fisher exact test, Kaplan-Meier analysis, and Cox proportional hazards regression. RESULTS: There were 24 ABF and 75 AISBR included in the study. The primary indication for treatment was claudication in 55 (55.6%) patients, rest pain in 28 (28.3%), and tissue loss in 16 (16.2%). Patients undergoing AISBR were more likely to be female. Femoral endarterectomies were performed in 37/75 (49.3%) AISBR and 14/24 (58.3%) ABF (P = 0.44). AISBR were performed percutaneously in 34/75 (45.1%). No AISBR required conversion to ABF. Intraoperative blood loss, procedure time and hospital length of stay (LOS) were significantly less for AISBR compared to ABF. Surgical site infections (SSI) were less common in patients undergoing AISBR (AISBR: 6/75 (8.0%) vs. ABF: 9/24 (37.5%), (P< 0.01). One AISBR and two 2 ABF developed late SSI >30 days postoperatively. The reductions in blood loss, LOS and SSI remained significant after excluding percutaneous AISBR from the analysis. Five-year primary patency was 50.8% (95% CI: 33.3, 68.4%) for AISBR and 88.1% (72.7, 100.0%) for ABF (P= 0.04). Five-year survival was 76.5% (95% CI: 63.6, 89.5) for AISBR and 100% (95% CI: 100.0, 100.0) for ABF (P = 0.07). Five-year primary assisted patency, secondary patency, freedom from reintervention and major adverse limb events did not differ significantly between groups. CONCLUSIONS: AISBR is a viable option for management of TASC II D AIOD, with lower morbidity and acceptable durability when compared to traditional ABF.

Stress testing before abdominal aortic aneurysm repair does not lead to a reduction in perioperative cardiac events.

OBJECTIVE: Stress testing is often used before abdominal aortic aneurysm (AAA) repair. Whether stress testing leads to a reduction in cardiac events after AAA repair has remained unclear. Our objective was to study the national stress test usage rates and compare the perioperative outcomes between centers with high and low usage of stress testing. METHODS: We used the Vascular Quality Initiative to study patients who had undergone elective endovascular AAA repair (EVAR) or open AAA repair (OAR). We measured the usage rates of stress testing across centers and compared the Vascular Study Group of New England cardiac risk index (VSG-CRI) among patients who had and had not undergone preoperative stress testing. We determined the rate of major adverse cardiac events (MACE), a composite of perioperative myocardial infarction, stroke, heart failure exacerbation, and death across the centers. We compared the MACE and 1-year mortality between the centers in the highest quintile of stress test usage and the lowest quintile. RESULTS: We studied 43,396 EVAR patients and 8935 OAR patients across 324 centers. The median proportion of stress test usage across centers before EVAR was 35.9% and varied from 10.2% (5th percentile) to 73.7% (95th percentile), with similar variability for OAR (median, 57.9%; 5th percentile, 13.0%; 95th percentile, 86.0%). The mean VSG-CRI for the EVAR group with preoperative stress testing was 5.6 ± 2.1 compared with 5.4 ± 2.1 (P < .001) for the EVAR group without preoperative stress testing. The findings were similar for OAR, with a VSG-CRI of 5.1 ± 2.0 vs 4.8 ± 2.1 (P < .001) for those with and without preoperative stress testing, respectively. The rate of MACE was 1.8% after EVAR and 11.6% after OAR. The 1-year mortality was 4.6% for EVAR and 6.6% for OAR. The centers in the highest quintile of stress testing had a higher adjusted likelihood of MACE after both EVAR (odds ratio [OR], 1.78; 95% confidence interval [CI], 1.37-2.30) and OAR (OR, 1.99; 95% CI, 1.53-2.59) but similar 1-year mortality (EVAR: OR, 1.18; 95% CI, 1.02-1.37; OAR: OR, 0.87; 95% CI, 0.65-1.17) compared with the centers in the lowest quintile. The VSG-CRI was not different between the high stress test centers (EVAR, 5.5 ± 2.1; OAR: 5.0 ± 2.0), and low stress test centers (EVAR, 5.5 ± 2.1; P = .403; OAR, 4.9 ± 2.0; P = .563). CONCLUSIONS: Stress test usage before AAA repair varied widely across Vascular Quality Initiative centers despite similar patient risk profiles. No reduction was observed in MACE or 1-year mortality among centers with high stress test usage. The value of routine stress testing before AAA repair should be reconsidered, and stress testing should be used more selectively, given these findings and the associated costs of widespread testing.

Concomitant ipsilateral carotid endarterectomy and stenting is an effective treatment for tandem carotid artery lesions.

OBJECTIVE: Data regarding the treatment of tandem carotid artery lesions at the bifurcation and ipsilateral, proximal common carotid artery (CCA) are limited. It has been suggested that concomitant treatment with carotid endarterectomy (CEA) and proximal ipsilateral carotid artery stenting confers a high risk of stroke and death. The objective of this study was to evaluate the technique and outcomes of this hybrid procedure at a single institution. METHODS: A retrospective chart review was performed including patients who underwent CEA + ipsilateral carotid artery stenting for treatment of atherosclerotic carotid artery disease between December 2007 and April 2017. Primary endpoints were postoperative myocardial infarction, neurologic event, and perioperative mortality. RESULTS: Twenty-two patients (15 male [68%]) underwent CEA + ipsilateral carotid artery stenting with a mean follow-up of 67 ± 77 months. The mean age was 70.0 ± 6.1 years old, all with a prior smoking history (eight current smokers [64%]). Twelve patients (55%) were treated for symptomatic disease and three had a prior ipsilateral CEA (one also with CAS). Computed tomographic angiography imaging was performed preoperatively in 21 patients (95%). CEA was performed first in 18 patients (82%) followed by ipsilateral carotid artery stenting. CEA was performed with a patch in 20 and eversion endarterectomy in two patients. Ipsilateral CCA was stented in 21 patients (96%) and one innominate was stented in a patient with a right CEA. Additional endovascular interventions were performed in three patients: 1 innominate stent, 1 distal ipsilateral internal carotid artery stent, and 1 right subclavian artery stent. All proximal stents were placed with sheath access through the endarterectomy patch in 12 (55%), CCA in 7 (32%), and through the arteriotomy before patching in 3 (14%). Distal internal carotid artery clamping was performed in 18 (90%, available 20) of patients before ipsilateral carotid artery stenting. All proximal lesions were successfully treated endovascularly with no open conversion. One dissection was created and treated effectively with stenting. One perioperative stroke (4.5%) occurred in a patient treated for symptomatic disease, 1 postoperative myocardial infarction (4.5%), and 2 patients (9.1%) with cranial nerve injuries. There was one patient who expired within 30 days, shortly after discharge for unknown reasons. The mean length of stay was 2.6 ± 2.0 days. CONCLUSIONS: In appropriately selected patients, concomitant CEA and ipsilateral carotid artery stenting can be safely performed in high-risk patients with a low risk of myocardial infarction, neurologic events, and perioperative mortality when careful surgical technique is used, using direct carotid access, and distal carotid clamping for cerebral protection before stenting.

Survival affects decision making for fenestrated and branched endovascular aortic repair.

OBJECTIVE: Repair options for complex abdominal and thoracoabdominal aortic aneurysms (TAAAs) are evolving with increased experience and availability of less invasive endovascular techniques. Identifying risk factors for mortality after fenestrated and branched endovascular aortic repair (F/B-EVAR) could improve patient selection and facilitate decision making regarding who may benefit from prophylactic F/B-EVAR. METHODS: We evaluated 1091 patients in a prospective investigational device exemption trial who underwent F/B-EVAR from August 2001 to June 2015 for complex aortic aneurysms (CAAs). Multivariable analysis of risk factors for death was performed using a nonproportional hazards model and a nonparametric analysis using random survival forest technology. RESULTS: Operative mortality after F/B-EVAR was low (3.7%), with high CAA-related survival at 30 day and 5 years (96.8% and 94.0%, respectively). All-cause 5-year survival, however, was 46.2% and older age, heart failure, chronic obstructive pulmonary disease, renal disease, anemia, and coagulation disorders were risk factors. Risk was highest for those undergoing type I/II TAAA repairs and those with larger aneurysms. CONCLUSIONS: Patients with multiple comorbidities and those undergoing type I or II TAAA repair are at greatest risk of mortality; however, in this high-risk population, F/B-EVAR offers greater survival compared with that reported for the natural history of untreated aneurysms. Operative and early mortality is lower than the best-reported open repair outcomes, even in this high-risk population, suggesting a potential benefit in extending the use of F/B-EVAR to low-to-average risk CAA patients.

Durable outcomes of thoracic endovascular aortic repair with Zenith TX1 and TX2 devices.

OBJECTIVE: Long-term data regarding the safety and durability of thoracic endovascular aortic repair (TEVAR) are limited. The study objective was to evaluate the long-term outcomes of TEVAR in high-risk patients with descending thoracic aortic pathology. METHODS: High-risk patients were treated with thoracic endografts (2001-2011) under a prospective, physician-sponsored, investigational device exemption trial. Three-dimensional reconstructions and measurements were performed on computed tomography scans acquired before discharge, at 1, 6, and 12 months, and then yearly thereafter. RESULTS: The study included 200 patients, of whom 171 were treated for thoracic aneurysm, 28 for chronic dissection, and 1 for aortobronchial fistula. Patients were monitored for an average of 4.8 ± 3.3 years, and 93 (46.5%) were monitored for >5 years. Operative mortality was 6.5%. Survival at 30 days and at 1, 5, and 9 years was 94.0%, 85.8%, 55.6%, and 31.4%, and freedom from aneurysm-related death was 94.0%, 92.4%, 91.7%, 91.7%, respectively. Sixty-one endoleaks occurred in 54 patients (28%). Sixty-seven reinterventions were performed in 50 patients. Overall freedom from reintervention at 30 days, 1, 5, and 9 years was 87.9%, 82.9%, 75.5%, and 64.0%, respectively. Forty-seven reinterventions (70%) were thoracic aneurysm-related, 35 (74%) of which were endovascular procedures. Thirty of these were to correct endoleaks at a median of 1.4 years (interquartile range, 0.2-5.0 years). CONCLUSIONS: TEVAR is durable and associated with high long-term aneurysm-related survival. Long-term imaging follow-up remains critical to identify endoleaks or rare device durability issues, most of which can be monitored or managed with endovascular therapies.

Postoperative Clostridium difficile infection has a differential procedure-specific association with surgical outcomes in contemporary United States practice.

BACKGROUND: The Centers for Disease Control and Prevention has made the prevention of in-hospital Clostridium difficile infection a priority. However, whether there is a differential impact of Clostridium difficile on surgical patients remains undefined. Therefore, we quantified the procedure-specific association between postoperative Clostridium difficile and surgical outcomes to define opportunities for targeted quality improvement. METHODS: We studied patients undergoing major cardiac, vascular, general, or oncologic procedures using the Vizient database from 2015 to 2019. Our primary exposure was postoperative Clostridium difficile infection. Our primary outcomes were postoperative length of stay, hospitalization cost, readmission, and in-hospital mortality. We used linear and logistic regression for risk adjustment. RESULTS: The incidence of Clostridium difficile infection was 1.6% (n = 6,506/397,750). Patients with Clostridium difficile were older, more comorbid, and more frequently underwent urgent surgery. The median postoperative length of stay was 7 days (interquartile range: 5-11 days), and it was 66% longer among those with Clostridium difficile (P < .001). Similarly, the median hospitalization cost was $31,000 (interquartile range: $20,000-$49,000), and it was 51% greater among patients with Clostridium difficile (P < .001). Postoperative Clostridium difficile was associated with more readmissions after coronary artery bypass grafting, small bowel resection, colectomy, gastrectomy, pancreatectomy, and infrainguinal bypass (adjusted odds ratio range: 1.4-1.7), but not after open aneurysm repair, suprainguinal bypass, or esophagectomy. Clostridium difficile was associated with increased mortality after coronary artery bypass grafting, small bowel resection, colectomy, and infrainguinal bypass (adjusted odds ratio range: 1.3-2.7), but not after open aneurysm repair, suprainguinal bypass, esophagectomy, gastrectomy, or pancreatectomy. CONCLUSION: Postoperative Clostridium difficile infection was differentially associated with increased length of stay, cost, readmissions, and mortality across specific procedures. This was most apparent after infrainguinal bypass, small bowel resection, colectomy, and coronary artery bypass grafting. Accordingly, a targeted Clostridium difficile reduction effort for these procedures may offer a more effective approach toward reducing infection rates.

Revascularization Strategies for Acute and Chronic Limb Ischemia.

Chronic limb-threatening ischemia requires aggressive risk factor management and a thoughtful approach to the complex decision of best strategy for revascularization. Patients often have multilevel disease amenable to endovascular, open surgical, or hybrid approaches. Limited high-quality evidence is available to support a specific strategy; randomized trials are ongoing. Acute limb ischemia is associated with a high risk of limb loss and mortality. Catheter-directed thrombolysis is mainstay of therapy in patients with marginally threatened limbs, whereas those immediately threatened with motor deficits require more rapid restoration of flow with open or endovascular techniques that can establish flow in single setting.

Sex-, Race- and Ethnicity-Based Differences in Thromboembolic Events Among Adults Hospitalized With COVID-19.

Background Patients hospitalized with COVID-19 have an increased risk of thromboembolic events. Whether sex, race or ethnicity impacts these events is unknown. We studied the association between sex, race, and ethnicity and venous and arterial thromboembolic events among adults hospitalized with COVID-19. Methods and Results We used the American Heart Association Cardiovascular Disease COVID-19 registry. Primary exposures were sex and race and ethnicity, as defined by the registry. Primary outcomes were venous thromboembolic events and arterial thromboembolic events. We used logistic regression for risk adjustment. We studied 21 528 adults hospitalized with COVID-19 across 107 centers (54.1% men; 38.1% non-Hispanic White, 25.4% Hispanic, 25.7% non-Hispanic Black, 0.5% Native American, 4.0% Asian, 0.4% Pacific Islander, and 5.9% other race and ethnicity). The rate of venous thromboembolic events was 3.7% and was more common in men (4.2%) than women (3.2%; P<0.001), and in non-Hispanic Black patients (4.9%) than other races and ethnicities (range, 1.3%-3.8%; P<0.001). The rate of arterial thromboembolic events was 3.9% and was more common in men (4.3%) than women (3.5%; P=0.002), and in non-Hispanic Black patients (5.0%) than other races and ethnicities (range, 2.3%-4.7%; P<0.001). Compared with men, women were less likely to experience venous thromboembolic events (adjusted odds ratio [OR], 0.71; 95% CI, 0.61-0.83) and arterial thromboembolic events (adjusted OR, 0.76; 95% CI, 0.66-0.89). Compared with non-Hispanic White patients, non-Hispanic Black patients had the highest likelihood of venous thromboembolic events (adjusted OR, 1.27; 95% CI, 1.04-1.54) and arterial thromboembolic events (adjusted OR, 1.35; 95% CI, 1.11-1.65). Conclusions Men and non-Hispanic Black adults hospitalized with COVID-19 are more likely to have venous and arterial thromboembolic events. These subgroups may represent at-risk patients more susceptible to thromboembolic COVID-19 complications.

In vivo and in vitro analysis of rat lumbar spine mechanics.

BACKGROUND: Rodent lumbar and caudal (tail) spine segments provide useful in vivo and in vitro models for human disc research. In vivo caudal models allow characterization of the effect of static and dynamic loads on disc mechanics of individual animals with time, but the lumbar models have required sacrifice of the animals for in vitro mechanical testing. QUESTIONS/PURPOSES: We therefore developed a novel displacement controlled in vivo lumbar spine noninvasive induced angular displacement (NIAD) test; data obtained with NIAD were used to compare angular displacement between segmental levels (L4/L5, L5/L6 and L6/S1), interobserver radiograph measurement agreement, and intraobserver radiograph measurement repeatability. Measurements from NIAD were compared with angular displacement, bending stiffness, and moment to failure measured by an in vitro test. METHODS: Anesthetized Lewis rats were xrayed in a 90° angled fixture, and NIAD was measured at lumbar levels L4 to S1 by two independent and blinded observers. After euthanasia, in vitro angular displacement (IVAD), stiffness, and failure moment were measured for the combined L4-L6 segment in four-point bending. RESULTS: NIAD was greater at L4/L5 and L5/L6 than at L6/S1. Combined coronal NIAD for L4-L6 was 42.8° ± 5.3° and for IVAD was 61.5° ± 3.8°. Reliability assessed by intraclass correlation coefficient (ICC) was 0.905 and 0.937 for intraobserver radiograph measurements, and interobserver ICCs ranged from 0.387 to 0.653 for individual levels. The interobserver ICC was 0.911 for combined data from all levels. Reliability for test-retest NIAD measurements had an ICC of 0.932. In vitro failure moment correlated with NIAD left bending. CONCLUSIONS: The NIAD method yielded reproducible and reliable rat lumbar spine angular displacement measurements without required euthanasia, and allows repetitive monitoring of animals with time. For lumbar spine research studies performed during a course of time, the NIAD method may reduce animal numbers required by providing serial angular displacement measurements without euthanasia. CLINICAL RELEVANCE: Improved methods to assess comparative models for disease or aging may permit enhanced clinical treatments and improved patient care.

Strategies for managing aortoiliac occlusions: access, treatment and outcomes.

Treatment of severe aortoiliac disease has dramatically evolved from a dependence on open aortobifemoral grafting to hybrid and endovascular only approaches. Open surgery has been the gold standard treatment of severe aortoiliac disease with excellent patency rates, but with increased length of stay and major complications. In contrast, endovascular interventions can successfully treat almost any lesion with decreased risk, compared to open surgery. Although primary patency rates remain inferior, secondary endovascular interventions are often minor procedures resulting in comparable long-term outcomes. The risks of renal insufficiency, embolization and access complications are not insignificant; however, most can be prevented or managed without significant clinical consequence. Endovascular therapies should be considered a first-line treatment option for all patients with aortoiliac disease, especially those with high-risk cardiovascular comorbidities.

Ventricular hypertrophy and left atrial dilatation persist and are associated with reduced survival after valve replacement for aortic stenosis.

OBJECTIVES: We sought to understand the factors modulating left heart reverse remodeling after aortic valve replacement, the relationship between the preoperative symptoms and modulators of left heart remodeling, and their influence on long-term survival. METHODS: From October 1991 to January 2008, 4264 patients underwent primary aortic valve replacement for aortic stenosis. Changes in the time course of left ventricular reverse remodeling were assessed using 5740 postoperative transthoracic echocardiograms from 3841 patients. RESULTS: Left ventricular hypertrophy rapidly declined after surgery, from 137 ± 42 g/m(2) preoperatively to 115 ± 27 by 2 years and remained relatively constant but greater than the upper limit of normal. The most important risk factor for residual left ventricular hypertrophy was greater preoperative left ventricular hypertrophy (P < .0001). Other factors included a greater left atrial diameter (reflecting diastolic dysfunction), a lower ejection fraction, and male gender. An increased postoperative transprosthesis gradient was associated with greater residual left ventricular hypertrophy; however, its effect was minimal. Preoperative severe left ventricular hypertrophy and left atrial dilatation reduced long-term survival, independent of symptom status. CONCLUSIONS: Severe left ventricular hypertrophy with left atrial dilatation can develop from severe aortic stenosis, even without symptoms. These changes can persist, are associated with decreased long-term survival even after successful aortic valve replacement, and could be indications for early aortic valve replacement if supported by findings from an appropriate prospective study.

Trabecular bone adaptation to loading in a rabbit model is not magnitude-dependent.

Although mechanical loading is known to influence trabecular bone adaptation, the role of specific loading parameters requires further investigation. Previous studies demonstrated that the number of loading cycles and loading duration modulate the adaptive response of trabecular bone in a rabbit model of applied loading. In the current study, we investigated the influence of load magnitude on the adaptive response of trabecular bone using the rabbit model. Cyclic compressive loads, producing peak pressures of either 0.5 or 1.0 MPa, were applied daily (5 days/week) at 1 Hz and 50 cycles/day for 4 weeks post-operatively to the trabecular bone on the lateral side of the distal right femur, while the left side served as an nonloaded control. The adaptive response was characterized by microcomputed tomography and histomorphometry. Bone volume fraction, bone mineral content, tissue mineral density, and mineral apposition rate (MAR) increased in loaded limbs compared to the contralateral control limbs. No load magnitude dependent difference was observed, which may reflect the critical role of loading compared to the operated, nonloaded contralateral limb. The increased MAR suggests that loading stimulated new bone formation rather than just maintaining bone volume. The absence of a dose-dependent response of trabecular bone observed in this study suggests that a range of load magnitudes should be examined for biophysical therapies aimed at augmenting current treatments to enhance long-term fixation of orthopedic devices.

Coronary artery disease and outcomes of aortic valve replacement for severe aortic stenosis.

OBJECTIVES: The study sought to contrast risk profiles and compare outcomes of patients with severe aortic stenosis (AS) and coronary artery disease (CAD) who underwent aortic valve replacement (AVR) and coronary artery bypass grafting (AS+CABG) with those of patients with isolated AS who underwent AVR alone. BACKGROUND: In patients with severe AS, CAD is often an incidental finding with underappreciated survival implications. METHODS: From October 1991 to July 2010, 2,286 patients underwent AVR+CABG and 1,637 AVR alone. A propensity score was developed and used for matched comparisons of outcomes (1,082 patient pairs). Analyses of long-term mortality were performed for each group, then combined to identify common and unique risk factors. RESULTS: Patients with AS+CAD versus isolated AS were older, more symptomatic, and more likely to be hypertensive, and had lower ejection fraction and greater arteriosclerotic burden but less severe AS. Hospital morbidity and long-term survival were poorer (43% vs. 59% at 10 years). Both groups shared many mortality risk factors; however, early risk among AS+CAD patients reflected effects of CAD; late risk reflected diastolic left ventricular dysfunction expressed as ventricular hypertrophy and left atrial enlargement. Patients with isolated AS and few comorbidities had the best outcome, those with CAD without myocardial damage had intermediate outcome equivalent to propensity-matched isolated AS patients, and those with CAD, myocardial damage, and advanced comorbidities had the worst outcome. CONCLUSIONS: Cardiovascular risk factors and comorbidities must be considered in managing patients with severe AS. Patients with severe AS and CAD risk factors should undergo early diagnostics and AVR+CABG before ischemic myocardial damage occurs.