Anahita Dua

Epidemiology of aortic aneurysm repair in the United States from 2000 to 2010

OBJECTIVE Broad application of endovascular aneurysm repair (EVAR) has led to a rapid decline in open aneurysm repair (OAR) and improved patient survival, albeit at a higher overall cost of care. The aim of this report is to evaluate national trends in the incidence of unruptured and ruptured abdominal aortic aneurysms (AAAs), their management by EVAR and OAR, and to compare overall patient characteristics and clinical outcomes between these two approaches. METHODS A retrospective analysis of the cross-sectional National Inpatient Sample (2000-2010) was used to evaluate patient characteristics and outcomes related to EVAR and OAR for unruptured and ruptured AAAs. Data were extrapolated to represent population-level statistics through the use of data from the U.S. Census Bureau. Comparisons between groups were made with the use of descriptive statistics. RESULTS There were 101,978 patients in the National Inpatient Sample affected by AAAs over the 11-year span of this study; the average age was 73 years, 21% were women, and 90% were white. Overall in-hospital mortality rate was 7%, with a median length of stay (LOS) of 5 days and median hospital charges of

Predicted shortfall in open aneurysm experience for vascular surgery trainees

58,305. In-hospital mortality rate was 13 times greater for ruptured patients, with a median LOS of 9 days and median charges of

Epidemiology of Peripheral Arterial Disease and Critical Limb Ischemia

84,744. For both unruptured and ruptured patients, EVAR was associated with a lower in-hospital mortality rate (4% vs 1% for unruptured and 41% vs 27% for ruptured; P < .001 for each), shorter median LOS (7 vs 2; 9 vs 6; P < .001) but a 27%-36% increase in hospital charges. CONCLUSIONS The overall use of EVAR has risen sharply in the past 10 years (5.2% to 74% of the total number of AAA repairs) even though the total number of AAAs remains stable at 45,000 cases per year. In-hospital mortality rates for both ruptured and unruptured cases have fallen by more than 50% during this time period. Lower mortality rates and shorter LOS despite a 27%-36% higher cost of care continues to justify the use of EVAR over OAR. For patients with suitable anatomy, EVAR should be the preferred management of both ruptured and unruptured AAAs.

Long-term follow-up and amputation-free survival in 497 casualties with combat-related vascular injuries and damage-control resuscitation.

OBJECTIVE Since the introduction of endovascular aneurysm repair (EVAR), the volume of open aneurysm repair (OAR) has steadily declined since 2000. The introduction of next-generation devices and branched and fenestrated endograft technology continues to increase the anatomic applicability of EVAR, further decreasing the need for OAR. This study models the decline in OAR and uses historical trends to forecast future decline in volume and its potential effect on vascular surgery training. METHODS An S-curve modified logistic function was used to model the effect of introducing a new technology (EVAR) on the standard management of abdominal aortic aneurysm (AAA) with OAR starting in the year 2000, when an International Classification of Diseases, Ninth Revision, code was first introduced for EVAR. Patients who underwent EVAR and OAR for AAA were determined using the Nationwide Inpatient Sample from 1998 to 2011. Weighted samples and data from the United States Census Bureau were used to extrapolate these numbers to estimate population statistics. The number of cases completed at teaching hospitals was calculated using the Nationwide Inpatient Sample, and Accreditation Council for Graduate Medical Education case logs were used to forecast the number of cases completed by vascular surgery trainees. RESULTS The highest number of OAR cases in this study was 42,872 in 2000 compared with just 10,039 in 2011. This was mirrored by a rise in EVAR from 2358 cases in 2000 (5.2%) to 35,028 in 2011 (76.5% by volume). Of the OAR volume in 2011, 6055 cases (60.3%) were completed at teaching institutions. An S-curve model with a correlation coefficient of R2 = 0.982 predicted 3809 open AAA cases at teaching hospitals by 2015, 2162 by 2020, and 1231 by 2025. When compared with the 2011 Accreditation Council for Graduate Medical Education National Resident Report, vascular surgery residents had 44.4% utilization with regard to OAR (2690 cases covered of 6055 total). When combined with the increase in vascular surgery trainees and lower number of open repairs, vascular fellows will complete about 10 OAR cases in 2015 and five OAR cases in 2020. CONCLUSIONS The decreasing number of OAR cases will limit exposure for vascular trainees, who may be ill equipped to treat patients who require open repair beyond 2015. Additional methods for providing OAR training should be explored.

The effect of hospital factors on mortality rates after abdominal aortic aneurysm repair

With a rise in the aging popluation, the prevalence of peripheral arterial disease (PAD) is markedly increasing. The overall disease prevalence of PAD is in the range of 3%-10%, which increases to 15%-20% in persons older than 70 years of age. Given this upward trend in disease prevalence, the economic and societal burden of PAD would be considerable. The subgroup of patients who develop critical limb ischemia (CLI) represents the most challenging population to manage medically, surgically, and endovascularly. Patients with symptomatic PAD and CLI have an increased risk for death and cardiovascular events, especially in those with CLI who carry with them a substantial risk of limb loss. Advances in medical, surgical, and endovascular techniques have shown excellent outcomes in the treatment of these patients, however the optimal management paradigm has not been elucidated. This article reviews the classification and epidemiology, risk factors, natural history, and health care costs associated with PAD and CLI.

The effect of Surgical Care Improvement Project measures on national trends on surgical site infections in open vascular procedures.

BACKGROUND The effectiveness of damage-control resuscitation (DCR) has been demonstrated in recent US conflicts. Wartime casualties treated for hemorrhagic shock from vascular wounds were studied to report the 24-hour transfusion requirements, graft patency, and amputation-free survival for major vascular injuries. METHODS Joint Theater Trauma Registry data from August 2006 to April 2011 (56 months) were retrospectively reviewed. Included were casualties with a vascular injury who presented to US combat support hospitals in Iraq or Afghanistan. Amputation-free survival and graft patency were determined from record and imaging review. RESULTS The study group consisted of 497 severely wounded local national and military casualties (mean [SD] Injury Severity Score [ISS], 17 [8.5]) presenting with acidosis (pH 7.29 [0.15]), tachycardia (heart rate, 110 [29.31]), and coagulopathy (international normalized ratio, 1.6 [2.33]). Given DCR and early management of vascular injury, blood pressure, heart rate, temperature, hemoglobin, and base deficit improved promptly (p < 0.05) by intensive care unit admission. Transfusion requirements included packed red blood cells (15 [13] U; range, 1–70 U), fresh frozen plasma (14 [13] U; range, 1–72 U), cryoprecipitate (13 [15] U; range, 1–49 U), and platelets (8 [6] U; range, 1–36 U). Mean operative time was 232 minutes (range, 16–763 minutes). US casualties (n = 111) had limb salvage attempted for 113 extremity vascular injuries (3 [2%] iliac, 33 [30%] femoral, 23 [20%] popliteal, 13 [12%] tibial, 33 [30%] brachial, 4 [3%] ulnar, and 4 [(3%] radial). In this subgroup, 28 (25%) were revascularized by a primary repair or end anastomosis, 80 (71%) were revascularized by saphenovenous grafts, and 5 (4%) were revascularized by prosthetic grafts. The follow-up ranged from 29 days to 1,079 days, (mean, 347 days), during which 96 grafts (84.9%) remained patent, 16 casualties (14.2%) required a delayed amputation, and 110 (99.1%) survived. Popliteal injuries had the highest amputation rate (7 of 23, 30.4%). The amputation-free survival was 84%. CONCLUSION In severely wounded casualties, wartime surgical strategies to save both life and limb evidently permit definitive procedures at initial surgery with excellent limb salvage results. This outcome analysis in a large cohort can help to refine surgical judgment and support contemporary DCR practices for major vascular injury. LEVEL OF EVIDENCE Epidemiologic study, level III; therapeutic study, level V.

Never-frozen liquid plasma blocks endothelial permeability as effectively as thawed fresh frozen plasma

BACKGROUND Patient factors that contribute to mortality from abdominal aortic aneurysm (AAA) repair have been previously described, but few studies have delineated the hospital factors that may be associated with an increase in patient mortality after AAA. This study used a large national database to identify hospital factors that affect mortality rates after open repair (OAR) and endovascular AAA repair (EVAR) of elective and ruptured AAA. METHODS A retrospective analysis was completed using the Nationwide Inpatient Sample from 1998 to 2011. International Classification of Disease, Ninth Revision codes were used to identify patients who underwent elective or ruptured AAA repair by OAR or EVAR. The association between mortality and hospital covariates, including ownership, bed size, region, and individual hospital volume for these patients was statistically delineated by analysis of variance, χ(2), and Mann-Kendall trend analysis. RESULTS A total of 128,232 patients were identified over the 14-year period, of which 88.5% were elective procedures and 11.5% were performed acutely for rupture. Most hospitals that complete elective OAR do between one and 50 cases, with mortality between 0% and 40%. Hospitals with mortality >40% uniformly complete fewer than five elective OAR cases annually and fall in the bottom 2.5% of all hospitals for mortality. Most hospitals that complete elective EVAR do between one and 70 cases, with mortality between 0% and 13%. Hospitals with mortality >13% uniformly complete fewer than eight elective EVAR cases annually and fall in the bottom 2.5% of all hospitals for mortality. The majority of hospitals that complete OAR or EVAR for ruptured AAA have between 0% to 100% for mortality, indicative of the high mortality risk associated with rupture. CONCLUSIONS Hospitals that complete fewer than five OARs or eight EVARs annually have significantly greater mortality compared with their counterparts. Improved implementation of best practices, more detailed informed consent to include hospital mortality data, and better regional access to health care may improve survival after elective AAA repair.

Changing paradigms in organ preservation and resuscitation.

OBJECTIVE The Surgical Care Improvement Project (SCIP) is a national initiative to reduce surgical complications, including postoperative surgical site infection (SSI), through protocol-driven antibiotic usage. This study aimed to determine the effect SCIP guidelines have had on in-hospital SSIs after open vascular procedures. METHODS The Nationwide Inpatient Sample (NIS) was retrospectively analyzed using International Classification of Diseases, Ninth Revision, diagnosis codes to capture SSIs in hospital patients who underwent elective carotid endarterectomy, elective open repair of an abdominal aortic aneurysm (AAA), and peripheral bypass. The pre-SCIP era was defined as 2000 to 2005 and post-SCIP was defined as 2007 to 2010. The year 2006 was excluded because this was the transition year in which the SCIP guidelines were implemented. Analysis of variance and χ(2) testing were used for statistical analysis. RESULTS The rate of SSI in the pre-SCIP era was 2.2% compared with 2.3% for carotid endarterectomy (P = .06). For peripheral bypass, both in the pre- and post-SCIP era, infection rates were 0.1% (P = .22). For open, elective AAA, the rate of infection in the post-SCIP era increased significantly to 1.4% from 1.0% in the pre-SCIP era (P < .001). Demographics and in-hospital mortality did not differ significantly between the groups. CONCLUSIONS Implementation of SCIP guidelines has made no significant effect on the incidence of in-hospital SSIs in open vascular operations; rather, an increase in SSI rates in open AAA repairs was observed. Patient-centered, bundled approaches to care, rather than current SCIP practices, may further decrease SSI rates in vascular patients undergoing open procedures.

Comparison of military and civilian popliteal artery trauma outcomes

BACKGROUND Thawed fresh frozen plasma (TP) is a preferred plasma product for resuscitation but can only be used for up to 5 days after thawing. Never-frozen, liquid plasma (LQP) is approved for up to 26 days when stored at 1°C to 6°C. We have previously shown that TP repairs tumor necrosis factor &agr; (TNF-&agr;)–induced permeability in human endothelial cells (ECs). We hypothesized that stored LQP repairs permeability as effectively as TP. METHODS Three single-donor LQP units were pooled. Aliquots were frozen, and samples were thawed on Day 0 (TP0) then refrigerated for 5 days (TP5). The remaining LQP was kept refrigerated for 28 days, and aliquots were analyzed every 7 days. The EC monolayer was stimulated with TNF-&agr; (10 ng/mL), inducing permeability, followed by a treatment with TP0, TP5, or LQP aged 0, 7, 14, 21, and 28 days. Permeability was measured by leakage of fluorescein isothiocyanate–dextran through the EC monolayer. Hemostatic profiles of samples were evaluated by thrombogram and thromboelastogram. Statistical analysis was performed using two-way analysis of variance, with p < 0.05 deemed significant. RESULTS TNF-&agr; increased permeability of the EC monolayer twofold compared with medium control. There was a significant decrease in permeability at 0, 7, 14, 21, and 28 days when LQP was used to treat TNF-&agr;–induced EC monolayers (p < 0.001). LQP was as effective as TP0 and TP5 at reducing permeability. Stored LQP retained the capacity to generate thrombin and form a clot. CONCLUSION LQP corrected TNF-&agr;–induced EC permeability and preserved hemostatic potential after 28 days of storage, similar to TP stored for 5 days. The significant logistical benefit (fivefold) of prolonged LQP storage improves the immediate availability of plasma as a primary resuscitative fluid for bleeding patients.

Outcomes of surgical paraclavicular thoracic outlet decompression

Purpose of reviewShortage of donor organs has increased consideration for use of historically excluded grafts. Ex-vivo machine perfusion is an emerging technology that holds the potential for organ resuscitation and reconditioning, potentially increasing the quality and number of organs available for transplantation. This article aims to review the recent advances in machine perfusion and organ preservation solutions. Recent findingsFlow and pressure-based machine perfusion has shown improved kidney graft function and survival, especially among expanded criteria donors. Pressure-based machine perfusion is demonstrating promising results in preservation and resuscitation of liver, pancreas, heart, and also lung grafts. August 2014 marked Food and Drug Administration approval of XPSTM- XVIVO Perfusion System (XVIVO Perfusion Inc., Englewood, Colorado, USA), a device for preserving and resuscitating lung allografts initially considered unsuitable for transplantation. Although there is no consensus among physicians about the optimal preservation solution, adding antiapoptotic and cell protective agents to preservation solutions is an interesting research area that offers potential to improve preservation. SummaryEx-vivo machine perfusion of solid organs is a promising method that provides the opportunity for resuscitation and reconditioning of suboptimal grafts, expanding the number and quality of donor organs.