Distal vessel pulmonary thromboendarterectomy: Results from a single institution.

BACKGROUND: Chronic thromboembolic pulmonary hypertension (CTEPH) is primarily managed by pulmonary thromboendarterectomy (PTE). As advanced surgical techniques permit resection at the segmental and subsegmental level, PTE can now be curative for CTEPH mostly involving the distal pulmonary arteries. METHODS: Between January 2017 and June 2021, consecutive patients undergoing PTE were categorized according to the most proximal level of chronic thrombus resection: Level I (main pulmonary artery), Level II (lobar), Level III (segmental) and Level IV (subsegmental). Proximal disease patients (any Level I or II) were compared to distal disease (Level III or IV bilaterally) patients. Demographics, medical history, preoperative pulmonary hemodynamics, and immediate postoperative outcomes were obtained for each group. RESULTS: During the study period, 794 patients underwent PTE, 563 with proximal disease and 231 with distal disease. Patients with distal disease more frequently had a history of an indwelling intravenous device, splenectomy, upper extremity thrombosis or use thyroid replacement and less often had prior lower extremity thrombosis or hypercoagulable state. Despite more use of PAH-targeted medications in the distal disease group (63.2% vs 50.1%, p < 0.001), preoperative hemodynamics were similar. Both patient groups exhibited significant improvements in pulmonary hemodynamics postoperatively with comparable in-hospital mortality rates. Compared to proximal disease, a lower percentage of patients with distal disease showed residual pulmonary hypertension (3.1% vs 6.9%, p = 0.039) and airway hemorrhage (3.0% vs 6.6%, p = 0.047) postoperatively. CONCLUSIONS: Thromboendarterectomy for distal (segmental and subsegmental) CTEPH is technically feasible and may result in favorable pulmonary hemodynamic outcomes, without increased mortality or morbidity.

Evaluation of Routine Coronary Angiography Before Pulmonary Thromboendarterectomy.

BACKGROUND: At the University of California, San Diego, routine coronary angiography has generally been performed in men 40 years of age and older and women 45 years of age and older before pulmonary thromboendarterectomy for chronic thromboembolic pulmonary hypertension (CTEPH). The prevalence of significant coronary artery disease (CAD) in this population has not been evaluated, however, and the optimal screening strategy has not been established. This study sought to evaluate whether the current approach may be better optimized on the basis of cardiac risk factors. METHODS: This study included 462 consecutive patients with CTEPH who were undergoing preoperative coronary angiography for pulmonary thromboendarterectomy. Baseline demographic and medical information was recorded. Major cardiac risk factors included: diabetes, hypertension, hyperlipidemia, body mass index 25 kg/m2 or greater, tobacco use, and family history of CAD. Charts were then reviewed for presence of significant CAD and revascularization. RESULTS: Significant CAD was found in 13.4% of patients who underwent routine preoperative coronary angiography; it was present in only 5% of patients younger than 50 years of age, compared with 16% of patients 50 years old and older. No patient younger than 50 years of age without cardiac risk factors was found to have significant CAD. Furthermore, in patients younger than 50 years of age, significant CAD was found only among those with 3 or more major risk factors. CONCLUSIONS: In patients younger than 50 years of age with CTEPH, the prevalence of significant CAD was low. Omitting preoperative coronary angiography in this subset of patients is reasonable when no coronary risk factors are present. Preoperative coronary angiography is warranted in individuals 50 years of age and older, as well as in those younger than 50 years who have significant risk factors for CAD.

Chronic Thromboembolic Pulmonary Hypertension: JACC Focus Seminar.

Chronic thromboembolic pulmonary hypertension (CTEPH) is the result of pulmonary arterial obstruction by organized thrombotic material stemming from incompletely resolved acute pulmonary embolism. The exact incidence of CTEPH is unknown but appears to approximate 2.3% among survivors of acute pulmonary embolism. Although ventilation/perfusion scintigraphy has been supplanted by computed tomographic pulmonary angiography in the diagnostic approach to acute pulmonary embolism, it has a major role in the evaluation of patients with suspected CTEPH, the presence of mismatched segmental defects being consistent with the diagnosis. Diagnostic confirmation of CTEPH is provided by digital subtraction pulmonary angiography, preferably performed at a center familiar with the procedure and its interpretation. Operability assessment is then undertaken to determine if the patient is a candidate for potentially curative pulmonary endarterectomy surgery. When pulmonary endarterectomy is not an option, pulmonary arterial hypertension-targeted pharmacotherapy and balloon pulmonary angioplasty represent potential therapeutic alternatives.

Efficacy of a Low-Tidal Volume Ventilation Strategy to Prevent Reperfusion Lung Injury after Pulmonary Thromboendarterectomy.

RATIONALE: Reperfusion lung injury is a postoperative complication of pulmonary thromboendarterectomy that can significantly affect morbidity and mortality. Studies in other postoperative patient populations have demonstrated a reduction in acute lung injury with the use of a low-tidal volume (Vt) ventilation strategy. Whether this approach benefits patients undergoing thromboendarterectomy is unknown. OBJECTIVES: We sought to determine if low-Vt ventilation reduces reperfusion lung injury in patients with chronic thromboembolic pulmonary hypertension undergoing thromboendarterectomy. METHODS: Patients undergoing thromboendarterectomy at one center were randomized to receive either low (6 ml/kg predicted body weight) or usual care Vts (10 ml/kg) from the initiation of mechanical ventilation in the operating room through Postoperative Day 3. The primary endpoint was the onset of reperfusion lung injury. Secondary outcomes included severity of hypoxemia, days on mechanical ventilation, and intensive care unit and hospital lengths of stay. MEASUREMENTS AND MAIN RESULTS: A total of 128 patients were enrolled and included in the analysis; 63 were randomized to the low-Vt group and 65 were randomized to the usual care group. There was no statistically significant difference in the incidence of reperfusion lung injury between groups (32%, n=20 in the low-Vt group vs. 23%, n=15 in the usual care group; P=0.367). Although differences were noted in plateau pressures (17.9 cm H2O vs. 20.1 cm H2O, P<0.001) and peak inspiratory pressures (20.4 cm H2O vs. 23.0 cm H2O, P<0.001) between the low-Vt and usual care groups, respectively, mean airway pressures, PaO2/FiO2, days on mechanical ventilation, and ICU and hospital lengths of stay were all similar between groups. CONCLUSIONS: In patients with chronic thromboembolic pulmonary hypertension undergoing pulmonary thromboendarterectomy, intra- and postoperative ventilation using low Vts (6 mg/kg) compared with usual care Vts (10 mg/kg) does not reduce the incidence of reperfusion lung injury or improve clinical outcomes. Clinical trial registered with www.clinicaltrials.gov (NCT00747045).

Prevalence of coronary artery-pulmonary artery collaterals in patients with chronic thromboembolic pulmonary hypertension.

This study sought to determine the prevalence of coronary artery-pulmonary artery collaterals in patients with chronic thromboembolic pulmonary hypertension (CTEPH) and to correlate their presence with the degree of clot burden. CTEPH is a treatable cause of severe pulmonary hypertension and right heart failure. Bronchopulmonary collateral vessels have been used as a supplementary diagnostic and prognostic tool for this disease. Coronary artery-pulmonary artery collaterals in this population have not been described. The coronary angiograms of 300 consecutive patients with CTEPH evaluated for pulmonary thromboendarterectomy (PTE) between January 1, 2007, and May 1, 2014, were examined. Of these patients, 259 (50% male; mean age, 58.3 ± 10.6 years) had cineangiographic images deemed adequate to definitively assess for the presence of coronary artery-pulmonary artery collaterals and were included in the final analyses. Pulmonary angiogram reports were reviewed for extent of pulmonary artery obstruction. The coronary angiograms of 259 age- and sex-matched control patients were also examined. Among 259 CTEPH patients with definitive imaging, 34 coronary artery-pulmonary artery collaterals were found in 28 patients (10.8%), versus 1 coronary artery-pulmonary artery collateral among control subjects (0.4%; P < 0.001). Compared with CTEPH patients without collaterals, patients with collaterals had a significantly higher prevalence of total occlusion of their right or left main pulmonary artery (P < 0.001) or lobar arteries (P < 0.001). In conclusion, the prevalence of coronary artery-pulmonary artery collaterals in CTEPH patients undergoing coronary angiography for possible PTE is approximately 11%. These vessels are associated with more severe pulmonary artery occlusion.

Impact of nurse-initiated ED sepsis protocol on compliance with sepsis bundles, time to initial antibiotic administration, and in-hospital mortality.

INTRODUCTION: Emergency nurses play a key role in the initial triage and care of patients with potentially life-threatening illnesses. The aims of this study were to (1) evaluate the impact of a nurse-initiated ED sepsis protocol on time to initial antibiotic administration, (2) ascertain compliance with 3-hour Surviving Sepsis Campaign (SSC) targets, and (3) identify predictors of in-hospital sepsis mortality. METHODS: A retrospective chart review investigated all adult patients-admitted through either of 2 academic tertiary medical center emergency departments-who were discharged with a diagnosis of severe sepsis or septic shock (N = 195). Pre- and post-protocol implementation data examined both compliance with 3-hour SSC bundle targets and patient outcomes. Multivariate logistic regression analysis identified predictors of in-hospital mortality. RESULTS: Serum lactate measurement (83.9% vs 98.7%, P = .003) and median time to initial antibiotic administration (135 minutes vs 108 minutes, P = .021) improved significantly after protocol implementation. However, one quarter of antibiotic administration times still exceeded the 3-hour target. Significant predictors of in-hospital mortality were respiratory dysfunction, central nervous system dysfunction, urinary tract infection, vasopressor administration, and patient body weight (P < .05). There were no in-hospital mortality rate differences between the pre- and post-protocol implementation groups. DISCUSSION: Compliance with serum lactate measurement and blood culture collection goals approached 100% in the post-protocol group. However, compliance with medical interventions requiring multiple health care-provider involvement (ie, antibiotic and fluid administration) remained suboptimal. Efforts focused on multidisciplinary bundle elements are necessary to achieve full compliance with SSC targets.

Baseline body mass index does not significantly affect outcomes after pulmonary thromboendarterectomy.

BACKGROUND: Obesity is a common comorbidity of patients with chronic thromboembolic pulmonary hypertension referred for pulmonary thromboendarterectomy, yet the effect of obesity on pulmonary thromboendarterectomy outcomes has not been well described. METHODS: We conducted a retrospective cohort study in which 476 consecutive operations over a 3.5-year period were examined to determine the effects of obesity on outcomes. Patients were grouped into four categories based on body mass index (BMI): less than 22 kg/m2, 22 to 30 kg/m2, 30 to 40 kg/m2, and more than 40 kg/m2. RESULTS: There were important differences in baseline pulmonary hemodynamics, with obese patients having significantly lower pulmonary vascular resistances than nonobese patients. All patients achieved a significant reduction in pulmonary vascular resistance, although the improvement was greatest in the lower BMI groups. The overall in-hospital mortality was 0.8%, and there were no differences in risk among BMI groups. Among the BMI groups, there were no differences in incidence of postoperative complications, including atrial fibrillation (overall 24.8%), reperfusion lung injury (overall 23.1%), and surgical site infection (overall 4.4%) or in median lengths of stay (including ventilator days, intensive care unit days, and postoperative length of stay). CONCLUSIONS: Pulmonary thromboendarterectomy outcomes have continued to improve, and this surgery can safely be completed in obese patients, previously deemed to be at high risk for poor outcomes.

Evaluation of patients with chronic thromboembolic pulmonary hypertension for pulmonary endarterectomy.

Pulmonary hypertension as a result of chronic thromboembolic disease (CTEPH) is potentially curable with pulmonary endarterectomy surgery. Consequently, correctly diagnosing patients with this type of pulmonary hypertension and evaluating these patients with the goal of establishing their candidacy for surgical intervention is of utmost importance. And as advancements in surgical techniques have allowed successful resection of segmental-level chronic thromboembolic disease, the number of CTEPH patients that are deemed suitable surgical candidates has expanded, making it even more important that the evaluation be conducted with greater precision. This article will review a diagnostic approach to patients with suspected chronic thromboembolic disease with an emphasis on the criteria considered in selecting patients for pulmonary endarterectomy surgery.

Pulmonary endarterectomy: recent changes in a single institution's experience of more than 2,700 patients.

BACKGROUND: Chronic thromboembolic pulmonary hypertension (CTEPH) is a known sequela of acute pulmonary embolic disease and yet remains underdiagnosed. Although nonsurgical options for patients with CTEPH have become increasingly available, including pulmonary artery hypertensive medical therapy, surgical endarterectomy provides the most appropriate intervention as a potential cure for this debilitating disorder. This article summarizes the most recent outcomes of pulmonary endarterectomy at a single institution over the past 12 years, with emphasis on the surgical approach to segmental-level chronic thromboembolic disease. METHODS: More than 2,700 pulmonary endarterectomy operations have been performed at the University of California, San Diego Medical Center. Because of recent changes in the patient population and in surgical results, 1,500 patients with symptomatic chronic thromboembolic disease who underwent pulmonary endarterectomy between March 1999 and December 2010 were analyzed. The outcomes for the more recent 500 patients, compared with the previous 1,000 were studied. RESULTS: In-hospital mortality for the cohort of 1,000 patients (group 1) was 5.2% compared with 2.2% for the last 500 operations (group 2) (p < 0.01). There was no mortality in the last 260 consecutive patients undergoing isolated pulmonary endarterectomy. More patients presented with segmental type III disease in the more recent 500 patients (21.4% versus 13.1%; p < 0.001). Between the 2 patient groups, there was a comparable decline in pulmonary vascular resistance (PVR) (group 1: 861.2 ± 446.2 to 94.8 ± 204.2 dynes/sec/cm(-5); group 2: 719.0 ± 383.2 to 253.4 ± 148.6 dynes/sec/cm(-5)) and mean pulmonary artery (PA) pressures (group 1: 46.1 ± 11.4 to 28.7 ± 10.1 mm Hg; group 2: 45.5 ± 11.6 to 26.0 ± 8.4 mm Hg) after endarterectomy. CONCLUSIONS: Despite a patient population with more distal disease, results continue to improve. Pulmonary endarterectomy for patients with CTEPH results in significant pulmonary hemodynamic improvement, with favorable outcomes achievable even in patients with distal segmental-level chronic thromboembolic disease.

Efficacy of methylprednisolone in preventing lung injury following pulmonary thromboendarterectomy.

BACKGROUND: We sought to determine the efficacy and safety of perioperative treatment with methylprednisolone on the development of lung injury after pulmonary thromboendarterectomy. METHODS: This was a randomized, prospective, double-blind, placebo-controlled study of 98 adult patients with chronic thromboembolic pulmonary hypertension who were undergoing pulmonary thromboendarterectomy at a single institution. The patients received either placebo (n = 47) or methylprednisolone (n = 51) (30 mg/kg in the cardiopulmonary bypass prime, 500 mg IV bolus following the final circulatory arrest, and 250 mg IV bolus 36 h after surgery). The primary end point was the presence of lung injury as determined by two independent, blinded physicians using prospectively defined criteria. The secondary end points included ventilator-free, ICU-free, and hospital-free days and selected levels of cytokines in the blood and in BAL fluid. RESULTS: The incidence of lung injury was similar in both treatment groups (45% placebo, 41% steroid; P = .72). There were no statistical differences in the secondary clinical end points between treatment groups. Treatment with methylprednisolone, compared with placebo, was associated with a statistically significant reduction in plasma IL-6 and IL-8, a significant increase in plasma IL-10, and a significant reduction in postoperative IL-1ra and IL-6, but not IL-8 in BAL fluid obtained 1 day after surgery. CONCLUSIONS: Perioperative methylprednisolone does not reduce the incidence of lung injury following pulmonary thromboendarterectomy surgery despite having an antiinflammatory effect on plasma and lavage cytokine levels.

Chronic thromboembolic pulmonary hypertension in pediatric patients.

OBJECTIVE: Chronic thromboembolic pulmonary hypertension is a rare form of pulmonary hypertension that can lead to progressive right heart failure and death. Pulmonary thromboendarterectomy surgery is the treatment of choice resulting in significant improvements in functional status, cardiopulmonary hemodynamics, and survival. This study reports the largest case series of pediatric patients with chronic thromboembolic pulmonary hypertension who underwent pulmonary thromboendarterectomy surgery at one institution. PATIENT AND METHODS: The University of California, San Diego, chronic thromboembolic pulmonary hypertension database identified patients 18 years or younger at the time of pulmonary thromboendarterectomy surgery (n = 17). Medical charts were reviewed for hemodynamics, thromboembolic risk factors, and postoperative outcomes. RESULTS: Pulmonary thromboendarterectomy surgery in pediatric patients resulted in improved functional status and significantly improved cardiopulmonary hemodynamics: mean arterial pressure decreased from 45.5 mm Hg ± 20.7 to 27.3 ± 13.0 mm Hg (P = .00073), pulmonary vascular resistance decreased from 929 ± dynes · s · cm(-5) to 299 ± 307 dynes · s · cm(-5) (P = .0012), and cardiac output improved from 3.8 ± 1.1 L/min to 5.6 ± 1.6 L/min (P = .0061). There were no deaths during surgery or 30 days after surgery, and long-term survival (5+ years) was achieved in 87.5%. As compared to adults with chronic thromboembolic pulmonary hypertension, there was a higher rate of rethrombosis in pediatric patients (38% vs 1%-4%). CONCLUSIONS: This study demonstrates that pulmonary thromboendarterectomy surgery in pediatric patients with chronic thromboembolic pulmonary hypertension is well tolerated with improved postoperative hemodynamics, functional status, minimal postoperative complications, and low perioperative mortality, similar to that reported for adults with chronic thromboembolic pulmonary hypertension, with the notable exception being a higher rate of rethrombosis in pediatric patients.

Bosentan as a bridge to pulmonary endarterectomy for chronic thromboembolic pulmonary hypertension.

OBJECTIVES: In proximal chronic thromboembolic pulmonary hypertension, pulmonary endarterectomy is the treatment of first choice. In general, medical treatment before pulmonary endarterectomy is not indicated. However, selected "high-risk" patients might benefit by optimization of pulmonary hemodynamics. Moreover, in patients whose surgery is delayed owing to limited medical resources, pretreatment may prevent clinical deterioration. The primary objective of this study was to determine whether the dual endothelin-1 antagonist bosentan improves pulmonary hemodynamics and functional capacity in patients with proximal chronic thromboembolic pulmonary hypertension waiting for pulmonary endarterectomy. METHODS: We used an investigator-initiated, randomized, controlled single-blind study. Patients were randomized to receive bosentan (n = 13) or no bosentan (n = 12) for 16 weeks, next to "best standard of care." The primary end point was change in total pulmonary resistance. Secondary end points included changes in 6-minute walk distance, mean pulmonary artery pressure, and cardiac index. RESULTS: After 16 weeks, the mean differences in change from baseline between the groups were as follows: total pulmonary resistance 299 dynes x s x cm(-5) (P = .004), 6-minute walk distance 33 m (P = .014), mean pulmonary artery pressure 11 mm Hg (P = .005), and cardiac index 0.3 L x min(-1) x m(-2) (P = .08). Treatment with bosentan was safe. After pulmonary endarterectomy, 4 patients died (no-bosentan group: n = 3); the short-term in-hospital postoperative clinical course was similar in both groups of patients. CONCLUSIONS: Patients with proximal chronic thromboembolic pulmonary hypertension may benefit hemodynamically and clinically from treatment with bosentan before pulmonary endarterectomy. Individual factors predictive of a beneficial response and whether this influences either morbidity or mortality associated with pulmonary endarterectomy remain to be established.

Pulmonary hypertensive medical therapy in chronic thromboembolic pulmonary hypertension before pulmonary thromboendarterectomy.

BACKGROUND: The currently recommended treatment for chronic thromboembolic pulmonary hypertension is pulmonary thromboendarterectomy (PTE). No convincing evidence for the use of pulmonary hypertensive medical therapy (PHT) exists in operable candidates. We sought to determine the prevalence of the use of PHT on referral for PTE and the effects on pre-PTE hemodynamics and post-PTE outcomes/hemodynamics. METHODS AND RESULTS: We performed a retrospective analysis of chronic thromboembolic pulmonary hypertension patients referred for PTE during 2005-2007. The prevalence of PHT was determined for all patients referred to our institution. Hemodynamic and outcomes analysis involved only those undergoing PTE. Data included baseline demographics, PHT medication(s), dosage, duration of therapy, and time to referral. Hemodynamic data were acquired from the time of diagnosis, the time of referral visit, and after PTE. Outcomes included intensive care unit, hospital, and ventilator days; bleeding and infection rates; incidence of reperfusion lung injury; and in-hospital mortality. The control group (n=244) was compared with the PHT group (n=111); subgroups included monotherapy with bosentan, sildenafil, or epoprostenol and combination therapy. The prevalence of PHT significantly increased from 19.9% in 2005 to 37% in 2007. There was minimal benefit of treatment with PHT on pre-PTE mean pulmonary artery pressure, but its use was associated with a significant delay in time to referral for PTE. Both groups experienced significant improvements in hemodynamic parameters after PTE. The 2 groups did not differ significantly in any post-PTE outcome. Similar results were obtained for each subgroup. CONCLUSIONS: Our results suggest that PHT use has minimal effect on pre-PTE hemodynamics and no effect on post-PTE outcomes/hemodynamics.

Chronic thromboembolic pulmonary hypertension.

The last 4 decades have witnessed dramatic changes in the treatment of patients with pulmonary hypertension. And with the advances in cardiothoracic surgical techniques, selected patients with chronic thromboembolic pulmonary hypertension (CTEPH) are afforded a surgical remedy for their disease. In the vast majority of these patients, surgical endarterectomy of chronic thromboemboli from the pulmonary vascular bed effectively treats even severe pulmonary hypertension, and as a result, the debilitating symptoms of right heart dysfunction. This article reviews the natural history of chronic thromboembolic disease and outline a suggested diagnostic approach to determine whether a patient with chronic thromboembolic disease might be an appropriate surgical candidate. Pulmonary thromboendarterectomy surgery, and the growing information on the use of pharmacotherapy in inoperable CTEPH, are also reviewed.

Identification of putative endothelial progenitor cells (CD34+CD133+Flk-1+) in endarterectomized tissue of patients with chronic thromboembolic pulmonary hypertension.

Chronic thromboembolic pulmonary hypertension (CTEPH) is characterized by a fibrotic thrombus persisting and obliterating the lumen of pulmonary arteries; its pathogenesis remains poorly defined. This study investigates a potential contribution for progenitor cell types in the development of vascular obliteration and remodeling in CTEPH patients. Endarterectomized tissue from patients undergoing pulmonary thromboendarterectomy was collected and examined for the structure and cellular composition. Our data show an organized fibrin network structure in unresolved thromboemboli and intimal remodeling in vascular wall tissues, characterized by smooth muscle alpha-actin (SM-alphaA)-positive cell proliferation in proximal regions (adjacent to thromboemboli) and neoangiogenesis/recanalization in distal regions (downstream from thromboemboli). Cells that are positively stained with CD34 and fetal liver kinase-1 (Flk-1) (CD34(+)Flk-1(+)) were identified in both the proximal and distal vascular tissues; a subpopulation of CD34(+)Flk-1(+)CD133(+) cells were further identified by immunostaining. Triple-positive cells are indicative of a population of putative endothelial progenitor cells or potential colony-forming units of endothelial cells. In addition, inflammatory cells (CD45(+)) and collagen-secreting cells (procollagen-1(+)) were detected in the proximal vascular wall. Some of the CD34(+) cells in CTEPH cells isolated from proximal regions were also positive for SM-alphaA. Our data indicate that putative progenitor cell types are present in the neointima of occluded vessels of CTEPH patients. It is possible that the microenvironment provided by thromboemboli may promote these putative progenitor cells to differentiate and enhance intimal remodeling.

Chronic thromboembolic pulmonary hypertension.

The description of organized thrombus in major pulmonary arteries can be found in autopsy reports dating back to the late nineteenth and early twentieth centuries. Not until the 1950s was the antemortem diagnosis and clinical syndrome of chronic thrombotic obstruction of the major pulmonary arteries better characterized. The first surgical attempt to remove the adherent thrombus from the vessel wall occurred in 1958. This operation provided the conceptual foundation for the distinction between acute and chronic thromboembolic disease of the pulmonary vascular bed, and established that an endarterectomy, and not an embolectomy, would be necessary if a surgical remedy for this disease was to be successful.

Postoperative management of the patient undergoing pulmonary endarterectomy.

The postoperative care of the patient undergoing pulmonary endarterectomy presents challenges that occur not only with other types of cardiac surgery but also with significant respiratory system changes related to alterations in pulmonary blood flow. Postoperative mortality associated with this procedure has declined substantially over the years as a consequence of improved evaluative procedures and selective surgical referral, advances in surgical technique, and an understanding of the unique postoperative complications that may occur. However, postoperative acute lung injury and residual pulmonary hypertension continue to represent major causes of mortality associated with this procedure and represent areas where additional investigative efforts are necessary. Here we describe the unique hemodynamic and respiratory changes that occur in the postoperative pulmonary endarterectomy patient and an evidence-based approach to their optimal management.

Fibrin derived from patients with chronic thromboembolic pulmonary hypertension is resistant to lysis.

RATIONALE: Although acute pulmonary embolism is epidemiologically associated with chronic thromboembolic pulmonary hypertension, the factors responsible for resistance to thrombolysis and a shift toward vascular remodeling within the pulmonary arteries of patients with chronic thromboembolic pulmonary hypertension are unknown. OBJECTIVE: Determine whether fibrin from patients is more resistant to plasmin-mediated lysis than fibrin from healthy control subjects. METHODS: Fibrinogen purified from patients and control subjects was used to prepare fibrin clots, which were subsequently digested with plasmin for various periods of time. The degradation of the alpha-, beta-, and gamma-chains of fibrin and the appearance of peptide fragments over time were assessed by polyacrylamide gel electrophoresis and Western blotting. MEASUREMENTS AND MAIN RESULTS: Densitometry of Coomassie-stained gels revealed significantly slower cleavage of all three polypeptide chains of fibrin from patients compared with control subjects (p < 0.05). In particular, release of N-terminal fragments from the beta-chain of fibrin, which promote cell signaling, cell migration, and angiogenesis, was retarded in patients compared with control subjects (p < 0.01). CONCLUSIONS: The relative resistance of patient fibrin to plasmin-mediated lysis may be due to alterations in fibrin(ogen) structure affecting accessibility to plasmin cleavage sites. The persistence of structural motifs of fibrin, such as the beta-chain N-terminus, within the pulmonary vasculature could promote the transition from acute thromboemboli into chronic obstructive vascular scars.

Massive pulmonary hemorrhage after pulmonary thromboendarterectomy.

Pulmonary thromboendarterectomy, the most common surgical treatment of chronic thromboembolic pulmonary hypertension, is being performed with increasing frequency throughout the world. Massive pulmonary hemorrhage is a potentially fatal complication of this procedure. In this report of three such cases, the diagnosis, clinical course, and possible treatments are discussed. Anesthesiologists involved in the care of patients receiving pulmonary thromboendarterectomy must be aware of the possibility of this complication, as well as the various techniques available for its treatment.

Chronic thromboembolic pulmonary hypertension.

During the past 2 decades, there has been a steady rise in the number of patients with chronic thromboembolic pulmonary hypertension (CTEPH) undergoing surgery and in the number of programs worldwide dedicated to the diagnosis and management of this patient population. This article discusses the natural history and clinical presentation of CTEPH, the evaluation of patients for pulmonary thromboendarterectomy, and the outcomes following surgery, along with a brief review of the procedure as performed at the University of California, San Diego.