Factors associated with lack of clinical improvement after vein ablation in the vascular quality initiative.

BACKGROUND: Insurance companies have adopted variable and inconsistent approval criteria for chronic venous disease (CVD) treatment. Although vein ablation (VA) is accepted as the standard of care for venous ulcers, the treatment criteria for patients with milder forms of CVD remain controversial. This study aims to identify factors associated with a lack of clinical improvement (LCI) in patients with less severe CVD without ulceration undergoing VA to improve patient selection for treatment. METHODS: We performed a retrospective analysis of patients undergoing VA for CEAP C2 to C4 disease in the Vascular Quality Initiative varicose veins database from 2014 to 2023. Patients who required intervention in multiple veins, had undergone prior interventions, or presented with CEAP C5 to C6 disease were excluded. The difference (Δ) in venous clinical severity score (VCSS; VCSS before minus after the procedure) was used to categorize the patients. Patients with a ΔVCSS of ≤0 were defined as having LCI after VA, and patients with ≥1 point decrease in the VCSS after VA (ΔVCSS ≥1) as having some benefit from the procedure and, therefore, "clinical improvement." The characteristics of both groups were compared, and multivariable regression analysis was performed to identify factors independently associated with LCI. A second analysis was performed based on the VVSymQ instrument, which measures patient-reported outcomes using five specific symptoms (ie, heaviness, achiness, swelling, throbbing pain, and itching). Patients with LCI showed no improvement in any of the five symptoms, and those with clinical improvement had a decrease in severity of at least one symptom. RESULTS: A total of 3544 patients underwent initial treatment of CVD with a single VA. Of the 3544 patients, 2607 had VCSSs available before and after VA, and 420 (16.1%) had LCI based on the ΔVCSS. Patients with LCI were more likely to be significantly older and African American and have CEAP C2 disease compared with patients with clinical improvement. Patients with clinical improvement were more likely to have reported using compression stockings before treatment. The vein diameters were not different between the two groups. The incidence of complications was overall low, with minor differences between the two groups. However, the patients with LCI were significantly more likely to have symptoms after intervention than those with improvement. Patients with LCI were more likely to have technical failure, defined as vein recanalization. On multivariable regression, age (odds ratio [OR], 1.01; 95% confidence interval [CI], 1.00-1.02) and obesity (OR, 1.47; 95% CI, 1.09-2.00) were independently associated with LCI, as was treatment of less severe disease (CEAP C2; OR, 1.82; 95% CI, 1.30-2.56) compared with more advanced disease (C4). The lack of compression therapy before intervention was also associated with LCI (OR, 6.05; 95% CI, 4.30-8.56). The analysis based on the VVSymQ showed similar results. CONCLUSIONS: LCI after VA is associated with treating patients with a lower CEAP class (C2 vs C4) and a lack of compression therapy before intervention. Importantly, no significant association between vein size and clinical improvement was observed.

Laser assisted trans-endograft coil embolization of a type II endoleak.

A type II endoleak after endovascular aneurysm repair can be challenging to stop. Numerous methods have been described, including trans-arterial, trans-lumbar, trans-caval, trans-endograft, peri-endograft, and open and laparoscopic surgical techniques. We present our experience with a laser-assisted trans-endograft approach, including technical variations of previous descriptions that might improve efficacy. In select cases, the laser-assisted trans-endograft approach might provide the most direct method of accessing and occluding the vessels feeding type II endoleaks.

Comparative outcomes of open mesenteric bypass after a failed endovascular or open mesenteric revascularization for chronic mesenteric ischemia.

INTRODUCTION: Clinical practice guidelines have recommended an endovascular-first approach (ENDO) for the management of patients with chronic mesenteric ischemia (CMI), whereas an open mesenteric bypass (OMB) is proposed for subjects deemed to be poor ENDO candidates. However, the impact of a previous failed endovascular or open mesenteric reconstruction on a subsequent OMB is unknown. Accordingly, this study was designed to examine the results of a remedial OMB (R-OMB) after a failed ENDO or a primary OMB (P-OMB) for patients with recurrent CMI. METHODS: All patients who underwent an OMB from 2002 to 2022 at the University of Florida were reviewed. Outcomes after an R-OMB (ie, history of a failed ENDO or P-OMB) and P-OMB were compared. The primary end point was 30-day mortality, whereas secondary outcomes included complications, reintervention, and survival. The Kaplan-Meier methodology was used to estimate freedom from reintervention and all-cause mortality, whereas multivariable Cox proportional hazards modeling identified predictors of death. RESULTS: A total of 145 OMB procedures (R-OMB, n = 48 [33%]; P-OMB, n = 97 [67%]) were analyzed. A majority of R-OMB operations were performed for a failed stent (prior ENDO, n = 39 [81%]; prior OMB, n = 9 [19%]). R-OMB patients were generally younger (66 ± 9 years vs P-OMB, 69 ± 11 years; P = .09) and had lower incidence of smoking exposure (29% vs P-OMB, 48%; P = .07); however, there were no other differences in demographics or comorbidities. R-OMB was associated with less intraoperative transfusion (0.6 units vs P-OMB, 1.4 units; P = .01), but there were no differences in conduit choice or bypass configuration.The overall 30-day mortality and complication rates were 7% (n = 10/145) and 53% (n = 77/145), respectively, with no difference between the groups. Notably, R-OMB had decreased cardiac (6% vs P-OMB, 21%; P < .01) and bleeding complication rates (2% vs P-OMB, 15%; P = .01). The freedom from reintervention (1 and 5 years: R-OMB: 95% ± 4%, 83% ± 9% vs P-OMB: 97% ± 2%, 93% ± 5%, respectively; log-rank P = .21) and survival (1 and 5 years: R-OMB: 82% ± 6%, 68% ± 9% vs P-OMB: 84% ± 4%, 66% ± 7%; P = .91) were similar. Independent predictors of all-cause mortality included new postoperative hemodialysis requirement (hazard ratio [HR], 7.4, 95% confidence interval [CI], 3.1-17.3; P < .001), pulmonary (HR, 2.7, 95% CI, 1.4-5.3; P = .004) and cardiac (HR, 2.4, 95% CI, 1.1-5.1; P = .04) complications, and female sex (HR, 2.1, 95% CI, 1.03-4.8; P = .04). Notably, R-OMB was not a predictor of death. CONCLUSIONS: The perioperative and longer-term outcomes for a remedial OMB after a failed intraluminal stent or previous open bypass appear to be comparable to a P-OMB. These findings support the recently updated clinical practice guideline recommendations for an endovascular-first approach to treating recurrent CMI due to the significant perioperative complication risk of OMB. However, among the subset of patients deemed ineligible for endoluminal reconstruction after failed mesenteric revascularization, R-OMB results appear to be acceptable and highlight the utility of this strategy in selected patients.

Size thresholds for repair of abdominal aortic aneurysms warrant reconsideration.

BACKGROUND: The historical size threshold for abdominal aortic aneurysm (AAA) repair is widely accepted to be 5.5 cm for men and 5.0 cm for women. However, contemporary AAA rupture risks may be lower than historical benchmarks, which has implications for when AAAs should be repaired. Our objective was to use contemporary AAA rupture rates to inform optimal size thresholds for AAA repair. METHODS: We used a Markov chain analysis to estimate life expectancy for patients with AAA. The primary outcome was AAA-related mortality. We estimated survival using Social Security Administration life tables and published contemporary AAA rupture estimates. For those undergoing repair, we modified survival estimates using data from the Vascular Quality Initiative and Medicare on complications, late rupture, and open conversion. We used this model to estimate the AAA repair size threshold that minimizes AAA-related mortality for 60-year-old average-health men and women. We performed a sensitivity analysis of poor-health patients and 70- and 80-year-old base cases. RESULTS: The annual risk of all-cause mortality under surveillance for a 60-year-old woman presenting with a 5.0 cm AAA using repair thresholds of 5.5 cm, 6.0 cm, 6.5 cm, and 7.0 cm was 1.7%, 2.3%, 2.7%, and 2.8%, respectively. The corresponding risk for a man was 2.3%, 2.9%, 3.3%, and 3.4% for the same repair thresholds, respectively. For a 60-year-old average-health woman, an AAA repair size of 6.1 cm was the optimal threshold to minimize AAA-related mortality. Life expectancy varied by <2 months for repair at sizes from 5.7 cm to 7.1 cm. For a 60-year-old average-health man, an AAA repair size of 6.9 cm was the optimal threshold to minimize AAA-related mortality. Life expectancy varied by <2 months for repair at sizes from 6.0 cm to 7.4 cm. Women in poor health, at various age strata, had optimal AAA repair size thresholds that were >6.5 cm, whereas men in poor health, at all ages, had optimal repair size thresholds that were >8.0 cm. CONCLUSIONS: The optimal threshold for AAA repair is more nuanced than a discrete size. Specifically, there appears to be a range of AAA sizes for which repair is reasonable to minmized AAA-related mortality. Notably, they all are greater than current guideline recommendations. These findings would suggest that contemporary AAA size thresholds for repair should be reconsidered.

Ventriculo-inferior-venacaval shunt salvage via endovascular surgery.

INTRODUCTION: Hydrocephalus treatment can be very challenging. While some hydrocephalic patients can be treated endoscopically, many will require ventricular shunting. Frequent shunt issues over a lifetime is not uncommon. Although most shunt malfunctions are of the ventricular catheter or valve, distal failures occur as well. A subset of patients will accumulate non-functioning distal drainage sites. CASE DESCRIPTION: We present a 27-year-old male with developmental delay who was shunted perinatally for hydrocephalus from intraventricular hemorrhage of prematurity. After failure of the peritoneum, pleura, superior vena cava (SVC), gallbladder, and endoscopy, an inferior vena cava (IVC) shunt was placed minimally-invasively via the common femoral vein. We believe this is only the eighth reported ventriculo-inferior-venacaval shunt. IVC occlusion years later was successfully treated with endovascular angioplasty and stenting followed by anticoagulation. To our knowledge, a ventriculo-inferior-venacaval shunt salvaged by endovascular surgery has not been previously described in the literature. CONCLUSION: After failure of the peritoneum, pleura, SVC, gallbladder, and endoscopy, IVC shunt placement is an option. Subsequent IVC occlusion can be rescued by endovascular angioplasty and stenting. Anticoagulation after stenting (and potentially after initial IVC placement) is advised.

The Contemporary Impact of Body Mass Index on Open Aortic Aneurysm Repair.

INTRODUCTION: The Centers for Disease Control and Prevention (CDC) has deemed obesity a national epidemic and contributor to other leading causes of death including heart disease, stroke, and diabetes. Accordingly, the role of body mass index (BMI) and its impact on surgical outcomes has been a focus of persistent investigation. The purpose of this study was to quantify the effect of BMI on open abdominal aortic aneurysm repair (oAAA) outcomes in contemporary practice. METHODS: All elective oAAAs in the VQI (2010-2021) were identified. End-points included 30-day death, in-hospital complications and 1-year mortality. Patients were stratified into four BMI cohorts (BMI<18.5, 18.5≤BMI<25, 25≤BMI<30, BMI≥30). Spline interpolation was used to explore a potential non-linear association between BMI and perioperative mortality. Mixed-effects Cox regression was used to assess the association between BMI and 1-year survival. RESULTS: 9,479 patients underwent oAAA over the study interval (median age-70, 74%-male, BMI 27±6). Lower BMI patients(<18.5) compared to higher BMI(>30) patients were more likely to be women (53% vs. 32%;p<.0001), current smokers(65% vs. 50%;p<.0001), and have COPD(58% vs. 37%;p<.0001). In contrast, an increased BMI was associated with a greater prevalence of diabetes and CAD (DM-26% vs. 6%;p<.0001; CAD-27% vs. 20%;p=.01). There was no difference in cross-clamp position or visceral/renal bypass between groups, though low BMI patients necessitated more frequent infrainguinal bypass(5% vs. 2%;p=.0002). 30-day mortality and in-hospital complications were greater among low BMI patients(30-day mortality:12% vs. 4%;p<.0001;complications-47% vs. 37%;p<.0001). Interestingly, low BMI conferred a nearly 2-fold increase in observed pulmonary complications(18% vs. 11%;p<.0001). Surgical site infections were twice as common among the lowest and highest BMI groups(4% vs. 2%;p<.0001). 1-year mortality was greatest among low BMI patients(23% vs. 9%;p<.0001). Adjusted spline-fit analysis demonstrated increased mortality among patients with BMI<21 or >34(BMI<18.5-HR 2.1, 95%CI 1.6-2.8;p<.0001; BMI>34-HR 1.3, 95%CI 1.1-1.6;p=.009). CONCLUSION: Both low (<18.5) and high (>34) BMI were associated with increased oAAA mortality in current practice. Despite the perception that obesity confers substantial surgical risk during oAAA, diminished BMI was associated with a 3-fold increase in 30-day and 1-year mortality. It appears that BMI extremes are distinct proxies for differential clinical phenotypes and should inform risk stratification for oAAA repair.

Outcomes of endovascular abdominal aortic aneurysm repair conversion in octogenarians treated at a high-volume aorta center.

BACKGROUND: Endovascular abdominal aortic aneurysm repair (EVAR) has become the dominant treatment strategy for infrarenal abdominal aortic aneurysms but has been especially preferred for octogenarian (age ≥80 years) patients because of concerns surrounding comorbidity severity and physiologic frailty. However, EVAR failure resulting in subsequent open conversion (EVAR-c) has been increasingly reported in older patients, although a paucity of literature focusing on the outcomes in this subgroup is available. The purpose of the present analysis was to evaluate our experience with EVAR-c for octogenarians (age ≥80 years) compared with that for younger patients (age <80 years). METHODS: A retrospective review of all nonmycotic EVAR-c procedures (2002-2020) at a single high-volume academic hospital with a dedicated aorta center (available at: https://www.uf-health-aortic-disease-center) was performed. A total of 162 patients were categorized into octogenarian (age ≥80 years; n = 43) and nonoctogenarian (age <80 years; n = 119) cohorts and compared. The primary end point was 30-day mortality. The secondary end points included complications, 90-day mortality, and overall survival. Cox regression was used to determine the effects of selected covariates on mortality risk. The Kaplan-Meier method was used to estimate survival. RESULTS: No differences in the preadmission EVAR reintervention rates were present (octogenarians, 42%; nonoctogenarians, 43%; P = 1.00) although the interval to the first reintervention was longer for the octogenarians (41 months) than for the nonoctogenarians (15 months; P = .01). In addition, the time to EVAR-c was significantly longer for the octogenarian patients (61 months) than for the nonoctogenarian patients (39 months; P < .01). No difference in rupture presentation was evident (14% vs 10%; P = .6). However, elective EVAR-c occurred less frequently for octogenarians (42%) than for nonoctogenarians (59%; P = .07). The abdominal aortic aneurysm diameter was significantly larger for elective octogenarian EVAR-c (7.8 ± 1.9 cm) than for nonoctogenarian EVAR-c (7.0 ± 1.5 cm; P = .02), and the presence of a type Ia endoleak was the most common indication overall (58%; n = 91). A trend toward greater 30-day mortality was evident for octogenarian patients (16%) compared with nonoctogenarian patients (7%; P = .06). Similarly, the 90-day mortality was greater for the octogenarian patients (26%) than for the nonoctogenarian patients (10%; P = .02). However, the incidence of any complication (56% vs 49%; P = .5), readmission rate (12% vs 6%; P = .3), unplanned reoperation rate (10% vs 5%; P = .5), and length of stay (11 days vs 9 days; P = .3) were not significantly different between the two groups. Age ≥80 years was predictive of short-term mortality after nonelective but not after elective surgery. However, increasing comorbidities, nonelective admission, and renal or mesenteric revascularization showed the strongest association with mortality risk. Survival at 1 and 3 years was not different between the two groups when comparing all patients after the first 90 days postoperatively. CONCLUSIONS: Although the unadjusted perioperative mortality was greater for octogenarian patients, the risk-adjusted elective outcomes were comparable to those for younger EVAR-c patients when treated at a high-volume aortic surgery center. This finding underscores the importance of appropriate patient selection and modulation of operative complexity when feasible to achieve optimal results. Providers caring for octogenarian patients with EVAR failure should consider timely elective referral to high-volume aorta centers to reduce resource usage and the frequency of nonelective presentations.

Effect of Mentoring on Match Rank of Integrated Vascular Surgery Residents.

BACKGROUND: Mentoring relationships have been encouraged for medical students interested in surgical specialties. We investigated the role of mentoring relationships of integrated vascular surgery residents, while in medical school. We hypothesized that mentoring relationships between medical students and vascular surgeons would have a positive effect on match outcome in the integrated vascular surgery residency match. METHODS: We used an online survey that respondents completed on a smartphone, tablet, or computer. This was created with Qualtrics Software. The survey was circulated to all North American Integrated Vascular Surgery residents, with the support of the Association of Program Directors in Vascular Surgery Recruitment Committee and the Society for Vascular Surgery Resident/Student Outreach Committee. Questions were posed either as Likert Scale or as multiple choice. Data were analyzed in Stata. RESULTS: Response rate (67 total responses of 241 polled residents) was 28%. Earlier postgraduate year residents were more likely to have had vascular surgeon mentors (P = 0.033). There was no association between having a mentor and match rank; however, those with vascular surgeon mentors matched higher on their rank list (P = 0.022). 50% of respondents indicated that mentoring was influential in the choice of integrated residency. Respondents with nonvascular surgeon mentors were more likely to answer negatively regarding their mentor's knowledge about other integrated (P < 0.0001) and traditional programs (P < 0.0001) while residents with a vascular surgeon mentor were more likely to respond positively to this question (P < 0.0001). Regarding the effectiveness of mentorship, 81% indicated their mentor was accessible, 92% responded that their mentor demonstrated professional integrity, and 76% responded that their mentor prioritized their success. CONCLUSIONS: Integrated vascular surgery residents were generally positive about their medical school mentors. Our data indicate that surgical mentorship in medical school is effective, both in influencing medical students to choose the vascular surgery specialty and in improving match rank-vascular surgeons were more knowledgeable and mentees with vascular surgeon mentors tended to be more successful in the match.

Ectonucleotidase tri(di)phosphohydrolase-1 (ENTPD-1) disrupts inflammasome/interleukin 1ß-driven venous thrombosis.

Deep vein thrombosis (DVT), caused by alterations in venous homeostasis is the third most common cause of cardiovascular mortality; however, key molecular determinants in venous thrombosis have not been fully elucidated. Several lines of evidence indicate that DVT occurs at the intersection of dysregulated inflammation and coagulation. The enzyme ectonucleoside tri(di)phosphohydrolase (ENTPD1, also known as CD39) is a vascular ecto-apyrase on the surface of leukocytes and the endothelium that inhibits intravascular inflammation and thrombosis by hydrolysis of phosphodiester bonds from nucleotides released by activated cells. Here, we evaluated the contribution of CD39 to venous thrombosis in a restricted-flow model of murine inferior vena cava stenosis. CD39-deficiency conferred a >2-fold increase in venous thrombogenesis, characterized by increased leukocyte engagement, neutrophil extracellular trap formation, fibrin, and local activation of tissue factor in the thrombotic milieu. This was orchestrated by increased phosphorylation of the p65 subunit of NFκB, activation of the NLRP3 inflammasome, and interleukin-1ß (IL-1ß) release in CD39-deficient mice. Substantiating these findings, an IL-1ß-neutralizing antibody attenuated the thrombosis risk in CD39-deficient mice. These data demonstrate that IL-1ß is a key accelerant of venous thrombo-inflammation, which can be suppressed by CD39. CD39 inhibits in vivo crosstalk between inflammation and coagulation pathways, and is a critical vascular checkpoint in venous thrombosis.

Empirical systemic anticoagulation is associated with decreased venous thromboembolism in critically ill influenza A H1N1 acute respiratory distress syndrome patients.

BACKGROUND: An association between increased venous thromboembolism (VTE) events and influenza A H1N1 (H1N1) was noted in the first 10 patients with severe acute respiratory distress syndrome (ARDS). An empirical systemic anticoagulation protocol (heparin intravenous infusion) was initiated when autopsy of patients with severe hypoxemia confirmed multiple primary pulmonary thrombi and emboli. The purpose of this study was to examine the relationship between H1N1 and VTE events and to assess the efficacy of empirical systemic heparin anticoagulation in preventing VTE and death in H1N1 severe ARDS patients. METHODS: An observational cohort study of critically ill severe ARDS patients with possible H1N1 viral pneumonia was performed in a surgical intensive care unit in a single 990-bed academic tertiary care center. Early empirical systemic heparin anticoagulation for all severe ARDS patients with possible H1N1 viral pneumonia was initiated as a VTE preventive strategy. RESULTS: Univariate comparisons and multivariate logistic regression were used to identify risk factors for VTE. Independent risk factors for VTE included H1N1, culture-positive bacterial pneumonia, and vasopressor requirement. Independent risk factors for pulmonary embolism included H1N1, culture-positive bacterial pneumonia, and male sex. H1N1 ARDS patients had 23.3-fold higher risk for pulmonary embolism and 17.9-fold increased risk for VTE. Kaplan-Meier analysis and log-rank test confirmed that empirical systemic heparin anticoagulation provided significant protection from thrombotic events in the H1N1-positive but not in the H1N1-negative critically ill ARDs patients. In multivariate analysis, adjusting for H1N1 status, patients without empirical systemic anticoagulation were 33 times more likely to have any VTE compared with those treated with empirical systemic heparin anticoagulation (P = .01). CONCLUSIONS: Critically ill patients with H1N1 ARDS have increased risk of venous thrombotic complications, particularly pulmonary thromboembolism. Empirical systemic heparin anticoagulation in this cohort of patients significantly reduced VTE incidence without increased hemorrhagic complications.

Pilot Study to Evaluate the Safety, Feasibility, and Financial Implications of a Postoperative Telemedicine Program.

BACKGROUND: Telemedicine in surgery holds promise for improving access and decreasing costs, but its role remains ill-defined. This pilot study was performed to investigate the safety, feasibility, and financial implications of providing postoperative care using an electronic clinic (eClinic) at a university hospital. METHODS: An easy-to-use and secure eClinic platform was constructed in Epic (Epic Systems Corporation, Verona, WA). Patients undergoing laparoscopic cholecystectomy, appendectomy, and hernia repairs on an adult acute care surgery service were enrolled in this program over an 11-month period (March 2017 to January 2018). Patients with prolonged hospitalizations (greater than 4 nights), perioperative complications, drains, and open wounds were excluded. Demographics, clinical outcomes, encounter time, patient satisfaction survey results, and cost analysis were compared with the traditional clinic (tClinic) patient population. RESULTS: Two hundred thirty-three eligible patients (61% female; mean age 41 ±â€Š16 years) were enrolled in this program. Their demographics were no different than the tClinic. Frequencies of readmission, reoperation, and emergency department visits (2.7%, 0%, and 4.2%, respectively) in the eClinic group were also similar to the tClinic group. However, total visit time was significantly shorter in the eClinic group (14 vs 145 minutes, P < 0.01). Anonymous surveys demonstrated a high degree of satisfaction, with 85% of patients expressing desire to utilize the eClinic again. This program enhanced the capacity for new visits to tClinic, with a resultant projected increase in additional operative cases and revenue for the health care system. CONCLUSIONS: A safe and efficient postoperative telemedicine program can be constructed utilizing a widely available electronic medical record system, which can improve patient satisfaction, optimize throughput, and increase gross charges for the healthcare system.

Macrophage-Mediated Inflammation in Normal and Diabetic Wound Healing.

The healing of cutaneous wounds is dependent on the progression through distinct, yet overlapping phases of wound healing, including hemostasis, inflammation, proliferation, and resolution/remodeling. The failure of these phases to occur in a timely, progressive fashion promotes pathologic wound healing. The macrophage (MΦ) has been demonstrated to play a critical role in the inflammatory phase of tissue repair, where its dynamic plasticity allows this cell to mediate both tissue-destructive and -reparative functions. The ability to understand and control both the initiation and the resolution of inflammation is critical for treating pathologic wound healing. There are now a host of studies demonstrating that metabolic and epigenetic regulation of gene transcription can influence MΦ plasticity in wounds. In this review, we highlight the molecular and epigenetic factors that influence MΦ polarization in both physiologic and pathologic wound healing, with particular attention to diabetic wounds.

Unfractionated heparin versus low-molecular-weight heparin for venous thromboembolism prophylaxis in trauma.

BACKGROUND: Venous thromboembolism (VTE) is a common complication in trauma patients. Pharmacologic prophylaxis is utilized in trauma patients to reduce their risk of a VTE event. The Eastern Association for the Surgery of Trauma guidelines recommend use of low-molecular-weight heparin (LMWH) as the preferred agent in these patients. However, there is literature suggesting that unfractionated heparin (UFH) is an acceptable, and less costly, alternative VTE prophylaxis agent with equivalent efficacy in trauma patients. We examined data from the Michigan Trauma Quality Improvement Program to perform a comparative effectiveness study of UFH versus LMWH on outcomes for trauma patients. METHODS: We conducted an analysis of the Michigan Trauma Quality Improvement Program data from January 2012 to December 2014. The data set contains information on date, time, and drug type of the first dose of VTE prophylaxis. Thirty-seven thousand eight hundred sixty-eight patients from 23 hospitals were present with an Injury Severity Score of 5 or greater and hospitalization for more than 24 hours. Patients were excluded if they died within 24 hours or received no pharmacologic VTE prophylaxis or agents other than UFH or LMWH while admitted to the hospital. We compared patients receiving LMWH to those receiving UFH. Outcomes assessed were VTE event, pulmonary embolism, deep vein thrombosis, and mortality during hospitalization. We used a generalized estimating equation approach to fit population-averaged logistic regression models with the type of first dose of VTE prophylaxis as the independent variable. Unfractionated heparin was considered the reference value. Timing of the first dose of VTE prophylaxis was entered into the model in addition to standard covariates. Odds ratios were generated for each of the dependent variables of interest. RESULTS: The analysis cohort consisted of 18,010 patients. Patients administered LMWH had a decreased risk of mortality (odds ratio, 0.64; confidence interval, 0.49-0.83), VTE (odds ratio, 0.67; confidence interval, 0.53-0.84), pulmonary embolism (odds ratio, 0.53; confidence interval, 0.35-0.79), and deep vein thrombosis (odds ratio, 0.73; confidence interval, 0.57-0.95) when compared with UFH following risk adjustment and accounting for hospital effect. The reduced risk of a VTE event for patients receiving LMWH was most pronounced for patients in the lower injury-severity categories. CONCLUSIONS: In our examination of VTE prophylaxis drug effectiveness, LMWH was found to be superior to UFH in reducing the incidence of mortality and VTE events among trauma patients. Therefore, LMWH should be the preferred VTE prophylaxis agent for use in hospitalized trauma patients. LEVEL OF EVIDENCE: Therapeutic, level III.

Pathophysiology of varicose veins.

BACKGROUND: Varicose veins, a common problem with effects on quality of life, account for a significant cost burden on the health care system. Despite their prevalence, the pathophysiologic mechanism of varicose veins remains incompletely understood. The fundamental issue is whether venous hypertension and valvular incompetence precede and influence the development of vein wall changes or whether the reverse is true. METHODS: We have reviewed the English-language literature to provide the most current understanding of the hemodynamic and cellular and molecular processes that underlie the development of varicose veins. RESULTS: Data at this time remain inconclusive, with compelling arguments to be made for both sides. It is clear that valvular incompetence and hemodynamic factors play a significant role, despite heterogeneity in study findings and lack of clear data for a specific pattern of valvular incompetence as an inciting factor. Numerous factors influence the development of varices on the cellular level, including hypoxia, dysregulated apoptosis, and alterations in the extracellular matrix. CONCLUSIONS: Based on currently available evidence, varicose veins are a complex disease with multifactorial pathogenesis; it is as yet not possible to state conclusively what inciting factor is responsible for the development of varicose veins, and their development may result from imbalance of any number of several factors.