Impact of lung transplantation on diastolic dysfunction in recipients with pretransplant pulmonary hypertension.

OBJECTIVE: Pulmonary hypertension can cause left ventricular diastolic dysfunction through ventricular interdependence. Moreover, diastolic dysfunction has been linked to adverse outcomes after lung transplant. The impact of lung transplant on diastolic dysfunction in recipients with pretransplant pulmonary hypertension is not defined. In this cohort, we aimed to assess the prevalence of diastolic dysfunction, the change in diastolic dysfunction after lung transplant, and the impact of diastolic dysfunction on lung transplant outcomes. METHODS: In a large, single-center database from January 2011 to September 2021, single or bilateral lung transplant recipients with pulmonary hypertension (mean pulmonary artery pressure > 20 mm Hg) were retrospectively identified. Those without a pre- or post-transplant echocardiogram within 1 year were excluded. Diastolic dysfunction was diagnosed and graded according to the American Society of Echocardiography 2016 guideline on assessment of diastolic dysfunction (present, absent, indeterminate). McNemar's test was used to examine association between diastolic dysfunction pre- and post-transplant. Kaplan-Meier and Cox regression analysis were used to assess associations between pre-lung transplant diastolic dysfunction and post-lung transplant 1-year outcomes, including mortality, major adverse cardiac events, and bronchiolitis obliterans syndrome grade 1 or higher-free survival. RESULTS: Of 476 primary lung transplant recipients, 205 with pulmonary hypertension formed the study cohort (mean age, 56.6 ± 11.9 years, men 61.5%, mean pulmonary artery pressure 30.5 ± 9.8 mm Hg, left ventricular ejection fraction < 55% 9 [4.3%]). Pretransplant, diastolic dysfunction was present in 93 patients (45.4%) (grade I = 8, II = 84, III = 1), absent in 16 patients (7.8%), and indeterminate in 89 patients (43.4%), and 7 patients (3.4%) had missing data. Post-transplant, diastolic dysfunction was present in 7 patients (3.4%) (grade I = 2, II = 5, III = 0), absent in 164 patients (80.0%), and indeterminate in 15 patients (7.3%), and 19 patients (9.3%) had missing data. For those with diastolic dysfunction grades in both time periods (n = 180), there was a significant decrease in diastolic dysfunction post-transplant (148/169 patients with resolved diastolic dysfunction; McNemar's test P < .001). Pretransplant diastolic dysfunction was not associated with major adverse cardiac events (hazard ratio [HR], 1.08, 95% CI, 0.72-1.62; P = .71), bronchiolitis obliterans syndrome-free survival (HR, 0.67, 95% CI, 0.39-1.56; P = .15), or mortality (HR, 0.70, 95% CI, 0.33-1.46; P = .34) at 1 year. CONCLUSIONS: Diastolic dysfunction is highly prevalent in lung transplant candidates with normal left ventricular systolic function and pulmonary hypertension, and resolves in most patients after lung transplant regardless of patient characteristics. Pre-lung transplant diastolic dysfunction was not associated with adverse lung or cardiac outcomes after lung transplant. Collectively, these findings suggest that the presence of diastolic dysfunction in lung transplant recipients with pulmonary hypertension has no prognostic significance, and as such diastolic dysfunction and the associated clinical syndrome of heart failure with preserved ejection fraction should not be considered a relative contraindication to lung transplant in such patients.

Surgical Porcine Model of Chronic Myocardial Ischemia Treated by Exosome-laden Collagen Patch and Off-pump Coronary Artery Bypass Graft.

Chronic myocardial ischemia resulting from progressive coronary artery stenosis leads to hibernating myocardium (HIB), defined as myocardium that adapts to reduced oxygen availability by reducing metabolic activity, thereby preventing irreversible cardiomyocyte injury and infarction. This is distinct from myocardial infarction, as HIB has the potential for recovery with revascularization. Patients with significant coronary artery disease (CAD) experience chronic ischemia, which puts them at risk for heart failure and sudden death. The standard surgical intervention for severe CAD is coronary artery bypass graft surgery (CABG), but it has been shown to be an imperfect therapy, yet no adjunctive therapies exist to recover myocytes adapted to chronic ischemia. To address this gap, a surgical model of HIB using porcine that is amenable to CABG and mimics the clinical scenario was used. The model involves two surgeries. The first operation involves implanting a 1.5 mm rigid constrictor on the left anterior descending (LAD) artery. As the animal grows, the constrictor gradually causes significant stenosis resulting in reduced regional systolic function. Once the stenosis reaches 80%, the myocardial flow and function are impaired, creating HIB. An off-pump CABG is then performed with the left internal mammary artery (LIMA) to revascularize the ischemic region. The animal recovers for one month to allow for optimal myocardial improvement prior to sacrifice. This allows for physiologic and tissue studies of different treatment groups. This animal model demonstrates that cardiac function remains impaired despite CABG, suggesting the need for novel adjunctive interventions. In this study, a collagen patch embedded with mesenchymal stem cell (MSC)-derived exosomes was developed, which can be surgically applied to the epicardial surface distal to LIMA anastomosis. The material conforms to the epicardium, is absorbable, and provides the scaffold for the sustained release of signaling factors. This regenerative therapy can stimulate myocardial recovery that does not respond to revascularization alone. This model translates to the clinical arena by providing means of physiological and mechanistic explorations regarding recovery in HIB.

Right heart failure after left ventricular assist device implantation: a persistent problem.

Left ventricular assist device (LVAD) is an option for bridge-to-transplant or destination therapy for patients with end-stage heart failure. Right heart failure (RHF) remains a complication after LVAD implantation that portends high morbidity and mortality, despite advances in LVAD technology. Definitions of RHF vary, but generally include the need for inotropic or pulmonary vasodilator support, or potential right ventricular (RV) mechanical circulatory support. This review covers the complex pathophysiology of RHF related to underlying myocardial dysfunction, interventricular dependence, and RV afterload, as well as treatment strategies to curtail this challenging problem.

Stem cell-derived exosome patch with coronary artery bypass graft restores cardiac function in chronically ischemic porcine myocardium.

OBJECTIVE: This study aimed to investigate whether or not the application of a stem cell-derived exosome-laden collagen patch (EXP) during coronary artery bypass grafting (CABG) can recover cardiac function by modulating mitochondrial bioenergetics and myocardial inflammation in hibernating myocardium (HIB), which is defined as myocardium with reduced blood flow and function that retains viability and variable contractile reserve. METHODS: In vitro methods involved exposing H9C2 cardiomyocytes to hypoxia followed by normoxic coculture with porcine mesenchymal stem cells. Mitochondrial respiration was measured using Seahorse assay. GW4869, an exosomal release antagonist, was used to determine the effect of mesenchymal stem cells-derived exosomal signaling on cardiomyocyte recovery. Total exosomal RNA was isolated and differential micro RNA expression determined by sequencing. In vivo studies comprised 48 Yorkshire-Landrace juvenile swine (6 normal controls, 17 HIB, 19 CABG, and 6 CABG + EXP), which were compared for physiologic and metabolic changes. HIB was created by placing a constrictor on the proximal left anterior descending artery, causing significant stenosis but preserved viability by 12 weeks. CABG was performed with or without mesenchymal stem cells-derived EXP application and animals recovered for 4 weeks. Before terminal procedure, cardiac magnetic resonance imaging at rest, and with low-dose dobutamine, assessed diastolic relaxation, systolic function, graft patency, and myocardial viability. Tissue studies of inflammation, fibrosis, and mitochondrial morphology were performed posttermination. RESULTS: In vitro data demonstrated improved cardiomyocyte mitochondrial respiration upon coculture with MSCs that was blunted when adding the exosomal antagonist GW4869. RNA sequencing identified 8 differentially expressed micro RNAs in normoxia vs hypoxia-induced exosomes that may modulate the expression of key mitochondrial (peroxisome proliferator-activator receptor gamma coactivator 1-alpha and adenosine triphosphate synthase) and inflammatory mediators (nuclear factor kappa-light-chain enhancer of activated B cells, interferon gamma, and interleukin 1ß). In vivo animal magnetic resonance imaging studies demonstrated regional systolic function and diastolic relaxation to be improved with CABG + EXP compared with HIB (P = .02 and P = .02, respectively). Histologic analysis showed increased interstitial fibrosis and inflammation in HIB compared with CABG + EXP. Electron microscopy demonstrated increased mitochondrial area, perimeter, and aspect ratio in CABG + EXP compared with HIB or CABG alone (P < .0001). CONCLUSIONS: Exosomes recovered cardiomyocyte mitochondrial respiration and reduced myocardial inflammation through paracrine signaling, resulting in improved cardiac function.

Fecal Microbiota Transplantation for Fulminant Clostridioides Difficile Infection: A Combined Medical and Surgical Case Series.

INTRODUCTION: Urgent abdominal colectomy is indicated for patients with fulminant Clostridioides difficile infection (CDI) when other medical therapies fail, yet mortality remains high. Fecal microbiota transplant is a less invasive alternative approach for patients with fulminant CDI. We report the 30-day complications of patients with fulminant CDI who underwent either abdominal colectomy, fecal microbiota transplantation (FMT), or FMT followed by abdominal colectomy (FMT-CO). Methods: We performed a single-center, retrospective case review of combined medical and surgical patients with CDI at a large academic medical center between 2008 and 2016. Cohorts were identified as patients with fulminant CDI who underwent total abdominal colectomy alone (CO), FMT alone (FMT), or FMT-CO. We analyzed patient demographics, history, comorbidities, clinical and laboratory variables, CDI severity scores, and mortality outcomes at 30 days. Results: We identified 5,150 patients with CDI at our center during the review period; 16 patients met the criteria for fulminant CDI and were included in this study, with four patients in the CO cohort, eight patients in the FMT cohort, and four patients in the FMT-CO cohort. Demographics and CDI severity scores were similar for all three groups, although the selected comorbidity profiles differed significantly among the three cohorts. The 30-day mortality rates for patients in the CO, FMT, and FMT-CO groups were 25%, 12.5%, and 25%, respectively. Conclusions: FMT is an alternative or adjunctive therapy to colectomy for patients with fulminant CDI that is not associated with increased mortality. Implementation of FMT protocols in clinical practice would be dependent on the availability of qualified transplant material and successful early identification of patients likely to benefit from FMT.

An Adjuvant Stem Cell Patch with Coronary Artery Bypass Graft Surgery Improves Diastolic Recovery in Porcine Hibernating Myocardium.

Diastolic dysfunction persists despite coronary artery bypass graft surgery (CABG) in patients with hibernating myocardium (HIB). We studied whether the adjunctive use of a mesenchymal stem cells (MSCs) patch during CABG improves diastolic function by reducing inflammation and fibrosis. HIB was induced in juvenile swine by placing a constrictor on the left anterior descending (LAD) artery, causing myocardial ischemia without infarction. At 12 weeks, CABG was performed using the left-internal-mammary-artery (LIMA)-to-LAD graft with or without placement of an epicardial vicryl patch embedded with MSCs, followed by four weeks of recovery. The animals underwent cardiac magnetic resonance imaging (MRI) prior to sacrifice, and tissue from septal and LAD regions were collected to assess for fibrosis and analyze mitochondrial and nuclear isolates. During low-dose dobutamine infusion, diastolic function was significantly reduced in HIB compared to the control, with significant improvement after CABG + MSC treatment. In HIB, we observed increased inflammation and fibrosis without transmural scarring, along with decreased peroxisome proliferator-activated receptor-gamma coactivator (PGC1α), which could be a possible mechanism underlying diastolic dysfunction. Improvement in PGC1α and diastolic function was noted with revascularization and MSCs, along with decreased inflammatory signaling and fibrosis. These findings suggest that adjuvant cell-based therapy during CABG may recover diastolic function by reducing oxidant stress-inflammatory signaling and myofibroblast presence in the myocardial tissue.

Considerations for a Holistic Model in Evaluating Medical Students for Cardiothoracic Surgical Residency.

Program directors are tasked with selecting whom they think will be the best fit for residency and the next leaders of the field. While numerical metrics have played a vital role in this process, recent changes to student evaluation are reducing the availability of these metrics. This poses unique challenges for both applicants and program directors. Here we discuss how this will likely shift the focus on other parts of the application and the consequences (good and bad) of doing so.

Persistent diastolic dysfunction in chronically ischemic hearts following coronary artery bypass graft.

OBJECTIVE: A porcine model was used to study diastolic dysfunction in hibernating myocardium (HM) and recovery with coronary artery bypass surgery (CABG). METHODS: HM was induced in Yorkshire-Landrace juvenile swine (n = 30) by placing a c-constrictor on left anterior descending artery causing chronic myocardial ischemia without infarction. At 12 weeks, animals developed the HM phenotype and were either killed humanely (HIB group; n = 11) or revascularized with CABG and allowed 4 weeks of recovery (HIB+CABG group; n = 19). Control pigs were matched for weight, age, and sex to the HIB group. Before the animals were killed humanely, cardiac magnetic resonance imaging (MRI) was done at rest and during a low-dose dobutamine infusion. Tissue was obtained for histologic and proinflammatory biomarker analyses. RESULTS: Diastolic peak filling rate was lower in HIB compared with control (5.4 ± 0.7 vs 6.7 ± 1.4 respectively, P = .002), with near recovery with CABG (6.3 ± 0.8, P = .06). Cardiac MRI confirmed preserved global systolic function in all groups. Histology confirmed there was no transmural infarction but showed interstitial fibrosis in the endomysium in both the HIB and HIB+CABG groups compared with normal myocardium. Alpha-smooth muscle actin stain identified increased myofibroblasts in HM that were less apparent post-CABG. Cytokine and proteomic studies in HM showed decreased peroxisome proliferator-activator receptor gamma coactivator 1-alpha (PGC1-α) expression but increased expression of granulocyte-macrophage colony-stimulating factor and nuclear factor kappa-light-chain enhancer of activated B cells (NFκB). Following CABG, PGC1-α and NFκB expression returned to control whereas granulocyte-macrophage colony-stimulating factor, tumor necrosis factor-α, and interferon gamma remained increased. CONCLUSIONS: In porcine model of HM, increased NFκB expression, enhanced myofibroblasts, and collagen deposition along with decreased PGC1-α expression were observed, all of which tended toward normal with CABG. Estimates of impaired relaxation with MRI within HM during increased workload persisted despite CABG, suggesting a need for adjuvant therapies during revascularization.

New-onset postoperative atrial fibrillation after mitral valve surgery: Determinants and the effect on survival.

Objective: Mitral valve surgery (MVS) carries substantial risk of postoperative atrial fibrillation (PAF). Identifying patients who benefit from prophylactic left atrial appendage amputation (LAAA) or maze is ill-defined. To guide such interventions, we determined preoperative predictors of PAF and investigated 3-year survival of patients with PAF. Methods: We performed a retrospective analysis of patients undergoing isolated MVS (N = 670) between 2011 and 2021. Patients with preoperative atrial fibrillation, LAAA or pulmonary vein isolation were excluded. Patient characteristics were compared between those without PAF and those who developed transient or prolonged PAF. Predictors of any PAF and prolonged PAF were identified using multivariable regression analysis. Results: In total, 504 patients without preoperative atrial fibrillation underwent isolated MVS. Of them, 303 patients (60.2%) developed PAF; 138 (27.3%) developed transient and 165 (32.7%) developed prolonged (beyond 30 days) PAF. Patients with PAF were older (65.7 vs 54.3 years, P < .001), with larger left atria (4.8 vs 4.3 cm, P < .001), greater prevalence of hypertension (60% vs 47.8%, P < .05), and were New York Heart Association class III/IV (36% vs 8.5%, P < .001). Independent predictors of PAF included left atria volume index (odds ratio [OR], 1.02; P < .003), older age (OR, 1.04; P < .001), heart failure (OR, 6.73; P < .001), and sternotomy (OR, 2.19; P < .002). Age, heart failure, and sternotomy were independent predictors of prolonged PAF. Patients with PAF had greater mortality at 3 years compared with those without PAF (5.3% vs 0.5%, P < .005). On multivariable analysis, PAF was associated with increased mortality (hazard ratio, 7.81; P < .046). Conclusions: PAF is common after MVS and associated with late mortality. Older age, advanced heart failure, and sternotomy are associated with prolonged PAF. These factors may identify patients who would benefit from prophylactic LAAA or ablation during MVS.

Sternal osteomyelitis caused by Aspergillus fumigatus years after coronary artery bypass grafting: A case report.

Sternal infection after cardiac surgery is an infrequent post-operative complication. Aspergillus sternal osteomyelitis is a rarity. We review the case of a 77-year-old man with invasive aspergillosis of the sternum and left costal cartilage 23 years after undergoing cardiac surgery. The patient promptly underwent surgical irrigation and debridement, followed by antifungal therapy. Clinical suspicion of sternal fungal infection should be high in patients with mediastinitis with a history of cardiac surgery. Treatment should be prompt.

Time since primary transplant and poor functional status predict survival after redo lung transplant.

Background: In previous studies, lower functional status measured by Karnofsky Performance Status (KPS) correlated with worse survival after redo lung transplant. We hypothesize that combining reduced functional status and time from primary lung transplant will correlate with the etiology of lung allograft failure after primary lung transplant and more accurately predict survival after redo lung transplant. Methods: This retrospective study was approved by University of Minnesota Institutional Review Board. From the Scientific Registry of Transplant Recipients (SRTR) database, 739 patients underwent redo lung transplant (01/01/2005-8/30/2019). Pre-lung transplant characteristics, KPS, time between primary and redo lung transplant, outcomes, overall survival were evaluated. Paired comparisons were used to compare pre-transplant variables. A Cox regression model was fit to examine re-transplant survival. Due to non-proportional hazards, time between transplants was split into <1-year vs. 1+ years and analyzed with time-dependent coefficients, with follow-up time considered in three segments (0-6, 6-24, 24+ months). Results: After KPS grouping (10-40%, 50-70%, 80-100%), KPS 10-40% were less likely to be discharged after primary transplant and more likely required mechanical ventilation or extracorporeal membrane oxygenation (ECMO) bridging (P<0.001). Redo lung transplant survival was worse in the KPS 10-40% group who more likely underwent lung transplant <1 year after primary lung transplant. Mortality was significantly higher for patients who underwent redo lung transplant within one year of primary transplant when KPS was 10-40% (P<0.001). These patients were more likely to require redo lung transplant due to primary graft failure or acute cellular rejection. Conclusions: Functional status and time from primary lung transplant are strong predictors of outcome after redo lung transplant. We categorized redo lung transplant recipients in two distinct groups. One group has early allograft failure and poor functional status with a very poor prognosis after redo lung transplant. The other group has chronic allograft failure and overall better functional status with relatively better survival after redo lung transplant. Salvage redo lung transplant for primary allograft failure or acute rejection is associated with low one year survival.

Novel Therapeutic Approaches Enhance PGC1-alpha to Reduce Oxidant Stress-Inflammatory Signaling and Improve Functional Recovery in Hibernating Myocardium.

Ischemic heart disease affects millions of people around the world. Current treatment options, including coronary artery bypass grafting, do not result in full functional recovery, highlighting the need for novel adjunctive therapeutic approaches. Hibernation describes the myocardial response to prolonged ischemia and involves a set of complex cytoprotective metabolic and functional adaptations. PGC1-alpha, a key regulator of mitochondrial energy metabolism and inhibitor of oxidant-stress-inflammatory signaling, is known to be downregulated in hibernating myocardium. PGC1-alpha is a critical component of cellular stress responses and links cellular metabolism with inflammation in the ischemic heart. While beneficial in the acute setting, a chronic state of hibernation can be associated with self-perpetuating oxidant stress-inflammatory signaling which leads to tissue injury. It is likely that incomplete functional recovery following revascularization of chronically ischemic myocardium is due to persistence of metabolic changes as well as prooxidant and proinflammatory signaling. Enhancement of PGC1-alpha signaling has been proposed as a possible way to improve functional recovery in patients with ischemic heart disease. Adjunctive mesenchymal stem cell therapy has been shown to induce PGC1-alpha signaling in hibernating myocardium and could help improve clinical outcomes for patients undergoing bypass surgery.

Lung Transplant Recipients With Prior Coronary Artery Bypass Grafting Are at Increased Risk of Death and Early Perioperative Hemorrhage.

Prior coronary artery bypass grafting (CABG) has been considered a relative contraindication to lung transplantation due to the atherosclerotic disease burden and technical challenges. We hypothesized that lung transplant recipients with prior CABG have increased mortality compared to recipients without prior CABG. Further, the causes of death are different for lung transplant recipients with prior CABG vs without CABG. The Scientific Registry of Transplant Recipients database was queried to define the survival and causes of death of lung transplant recipients with or without CABG during the Lung Allocation Score era from May 5, 2005 to December 31, 2015. The primary end-points were all-cause mortality at 1 year and 5 years, as well as mortality due to major causes of death. This retrospective study cohort included a total of 13,064 lung transplant recipients, of whom 319 patients had previously undergone CABG, representing 2.4% of all transplants. Patients without prior CABG were more likely to have undergone bilateral lung transplantation compared to those with prior CABG (61.2 % vs 15.7%, P < 0.001). Among patients with prior CABG, single right lung transplant was most common. Overall patient survival at 1 year was 76.8% for lung transplant recipients with prior CABG and 85.4% for patients without prior CABG. Freedom from death due to graft failure at 1 and 5 years in patients with a prior CABG was 93.1% and 76.2% respectively, cardiac and/or cerebrovascular disease 96.2% and 88.5% respectively, and hemorrhage 97.9% and 97.5% respectively. In a multivariate Cox regression model utilizing time-dependent coefficients for recipient age, prior CABG, among several other risk factors, was associated with increased mortality within 1 year. Prior CABG is associated with short- and long-term mortality in lung transplant recipients with history of CABG despite the majority of these patients undergoing single lung transplantation vs bilateral lung transplantation. Graft failure and/or pulmonary causes are the most common cause of death regardless of whether or not the lung transplant recipient had prior CABG, but patients with prior CABG are at increased risk of death due to graft failure, cardiac or cerebrovascular disease, and hemorrhage.

Four-extremity venous duplex ultrasound for suspected deep venous thrombosis is an anachronism.

BACKGROUND: Duplex ultrasound is the "gold standard" for diagnosis of acute deep venous thrombosis (DVT) because of its high specificity, sensitivity, safety, and portability. However, unnecessary testing epitomizes inefficient use of scarce health care resources. Here we hypothesize that the majority of simultaneous four-extremity duplex ultrasound (FED) examinations are unnecessary. By analyzing clinical factors of patients with acute DVT found on FED, we aimed to identify a subset of high-risk patients who may have a valid indication for four-extremity testing. METHODS: We retrospectively reviewed all venous duplex ultrasound examinations performed in our Intersocietal Accreditation Commission-accredited vascular laboratory from January 1, 2009, to December 31, 2016. Patients with duplex ultrasound scans of all four limbs were included. DVT risk factors and indication for duplex ultrasound examination were recorded. The primary outcome was finding of acute DVT. RESULTS: There were 188 patients who met our search criteria, of whom 31 patients (16.5%) had acute DVT (11 upper extremity, 16 lower extremity, and 4 upper and lower extremity). Fever of unknown origin (FUO) was the main indication for requesting FED (53.7%). Patients who underwent FED for FUO had a significantly lower likelihood of DVT (odds ratio, 0.21; P = .01). DVT was rarely the proximate cause (<1% of all cases) as follow-up culture results and clinical course most often revealed other sources of fever. Only patients with an upper extremity central venous catheter (CVC; n = 103) with at least two associated risk factors had an upper extremity DVT, which was usually line associated (93%). Only patients with at least two associated risk factors had a lower extremity DVT. CONCLUSIONS: FED for FUO is inefficient, given that DVT was rarely the proximate cause of fever. Acute upper extremity DVT was found only in patients with an upper extremity CVC, demonstrating that patients without upper extremity CVC do not benefit from upper extremity duplex ultrasound examination. Upper extremity DVT is usually line associated and dependent on the number of cumulative risk factors present, suggesting that only the extremity associated with the CVC in the right clinical context should be imaged. Lower extremity DVT is also dependent on the number of cumulative risk factors present, and testing should be reserved for patients according to the clinical context. Our results indicate that a restrictive strategy can reduce testing inefficiency and health care cost without compromising patients' safety.

Long-Term Results After Lung Volume Reduction Surgery: A Single Institution's Experience.

BACKGROUND: The National Emphysema Treatment Trial (NETT) showed a clear survival and quality of life benefit for patients selected for lung volume reduction surgery (LVRS). However, long-term outcomes after LVRS are still lacking. The aim of this study was to evaluate overall mortality and functional durability in this single-institution cohort of patients undergoing LVRS. METHODS: A single-institution registry identified all patients who had undergone LVRS from January 2006 through August 2017. Records were retrospectively reviewed, and data were collected to include pulmonary functions test values, he University of California, San Diego shortness of breath questionnaire and complication and mortality rate. RESULTS: LVRS was performed in 135 patients with a 2.2% 90-day mortality rate (n = 3). Estimated 1-, 2- and 5-year survival was 0.94 (95% confidence interval [CI], 0.88 to 0.97), 0.91 (95% CI, 0.83 to 0.95), and 0.71 (95% CI, 0.57 to 0.81), respectively. Mean improvement in forced expiratory volume in 1 second% predicted from preoperative baseline at 1 and 2 years was 5.3 (95% CI, 3.1 to 7.4) and 4.3 (95% CI, 1.9 to 6.6), respectively. There was a mean improvement in maximum workload of 5.2 W (95% CI, 0.9 to 9.4) at 1 year. Also, shortness of breath questionnaire scores had a mean decrease of -17.3 points (95% CI, -21.8 to -13) at 6 months and -13.9 points (95% CI, -18.4 to -9.3) at 1 year. CONCLUSIONS: LVRS is an effective operation with overall improvement in functional status and quality of life in appropriately selected patients.

Presence and degree of residual venous obstruction on serial duplex imaging is associated with increased risk of recurrence and progression of infrainguinal lower extremity deep venous thrombosis.

OBJECTIVE: The role of follow-up venous duplex ultrasound (DUS) after acute lower extremity deep vein thrombosis (DVT) remains unclear, yet it is commonly performed. We aimed to clarify the role of follow-up DUS. Our primary objective was to determine the association between the presence of residual venous obstruction (RVO) on DUS and DVT recurrence or propagation (rDVT). Secondary objectives included finding risk factors associated with RVO and rDVT. METHODS: We conducted a retrospective study of patients diagnosed with DVT on DUS from January 1, 2011, to December 31, 2013, that received a follow-up DUS. Patient demographics, risk factors, medications, and DUS findings were recorded. Ten segments from the common femoral to distal calf veins were checked for the presence of RVO, DVT propagation, and recurrence. RVO was defined as any nonacute venous obstruction with more than 40% of luminal diameter remaining during compression or the presence of chronic post-thrombotic occlusive disease. rDVT was measured as either a new acute DVT in the previously involved segment, or involvement of a new segment in the same extremity. RESULTS: A total of 185 lower extremities representing 156 patients met the inclusion criteria. RVO was noted in 61.1% of limbs. The 3-year rDVT rate was 10.3%. Patients with recurrent venous thromboembolism or thrombophilia had a higher risk of developing RVO (odds ratio [OR], 2.89, P < .01; OR, 4.39, P = .04, respectively). Extremities with larger clot burden had an increased risk of RVO on follow-up DUS (OR, 1.25 per segment; P < .01). The presence and degree of RVO on follow-up DUS had an increased risk of rDVT on subsequent DUS (OR, 3.90, P = .04; OR, 1.21 per segment, P = .04, respectively). Limbs with complete resolution of DVT by DUS had a significantly decreased risk of rDVT (OR, 0.26; P = .04). CONCLUSIONS: Extremities with larger initial clot burden exhibited an increased risk of subsequent RVO. The presence of RVO and, interestingly, the number of involved segments on follow-up DUS increased the risk of rDVT. Our results suggest that the presence of residual disease and increased RVO burden on follow-up DUS after an acute DVT may identify those patients who are at an increased risk for rDVT and may help guide the duration of anticoagulation therapy.