Venous Thromboembolic Complications of Lung Transplantation: A Contemporary Single-Institution Review

Venous thromboembolism following lung transplantation

Lung transplantation (LT) is currently a surgical therapy option for end-stage lung disease. Venous thromboembolism (VTE), which can occur after LT, is associated with significant morbidity and mortality. Because of improved outcomes, increasing numbers of patients are receiving LT as treatment. Patients on the waitlist for LT tend to be older with weakness and frailty in addition to pulmonary symptoms. These factors contribute to a heightened risk of postoperative VTE. Furthermore, patients who clinically deteriorate while on the waitlist may require extra corporeal membrane oxygenation as a bridge to LT. Bleeding and thromboembolism are common in these patients. Pulmonary embolism (PE) in a freshly transplanted lung can have significant effects leading to morbidity and mortality. PE typically leads to impairment of gas exchange and right ventricular strain. In LT, PE can affect healing of bronchial anastomosis and may even contribute to the development of chronic allograft lung dysfunction. This article discussed the incidence, clinical features and diagnosis of VTE after LT. Furthermore, the treatment modalities, complications, and outcomes of VTE were reviewed.

Survival in Patients With Evidence of Pulmonary Thromboembolism on Ventilation-Perfusion SPECT 12 Weeks After Double Lung Transplantation: A Retrospective Cohort Study

BACKGROUND

Patients who have undergone double lung transplantation (DLTx) are at increased risk of pulmonary thromboembolism (PTE). Although the presence of clinically overt PTE can adversely affect short-term mortality, the prognostic impact of asymptomatic (silent) PTE detected by routine imaging after DLTx is unclear. This study aimed to determine whether PTE identified by routine ventilation-perfusion single-photon emission computed tomography (V̇-Q̇ SPECT) 12 weeks post-DLTx is associated with subsequent all-cause and graft-related mortality.

METHODS

Single-center retrospective cohort study evaluating 130 DLTx recipients who underwent routine V̇-Q̇ SPECT imaging 12 weeks posttransplant between 2012 and 2017. V̇-Q̇ SPECT scans were assessed for perfusion and ventilation defects indicative of PTE. The association between PTE and mortality outcomes was analyzed using multivariable Cox regression, Kaplan-Meier survival curves, and cumulative incidence functions.

RESULTS

PTE was identified in 24.6% (n = 32) of the patients 12 weeks post-DLTx. After 3 months of follow-up, there was no detectable difference in lung function between patients with and without PTE. Moreover, the presence of PTE was not associated with increased hazard ratios for all-cause mortality (HR = 0.72; 95% CI: 0.37-1.41; p = 0.34) or graft-specific mortality (HR = 0.95; 95% CI: 0.42-2.16; p = 0.91).

CONCLUSIONS

PTE is a frequent finding on routine V̇-Q̇ SPECT 12 weeks post-DLTx that does not inform risk of all-cause or graft-related mortality. These findings suggest that an incidentally detected PTE in asymptomatic patients may not necessitate changes in clinical management for asymptomatic DLTx patients.

Pulmonary Embolism Following Lung Transplantation: Prevention and Management

Thromboembolic events are the third leading cardiovascular diagnosis following stroke and myocardial infarction. In the United States, 300,000 to 600,000 people per year are diagnosed with venous thromboembolism, either deep venous thrombosis or pulmonary embolism (PE). Of those patients, thousands die from PE despite heightened vigilance and improved therapies. Lung transplant recipients are at increased risk of developing PE due to multiple risk factors unique to this population. Additionally, the transplant recipients are more susceptible to morbid complications from PE. As a result, prevention, timely recognition, and intervention of PE in the lung transplant population are of the utmost importance.

Impact of anticoagulation intensity on blood transfusion for venoarterial extracorporeal membrane oxygenation during lung transplantation

Venoarterial extracorporeal membrane oxygenation is increasingly used for mechanical circulatory support during lung transplant. Optimal intensity of intraoperative anticoagulation would be expected to mitigate thromboembolism without increasing bleeding and blood product transfusions. Yet, the optimal intensity of intraoperative anticoagulation is unknown. We performed a retrospective cohort study of 163 patients who received a bilateral lung transplant at a single center. We categorized the intensity of anticoagulation into 4 groups (very low to high) based on the bolus dose of unfractionated heparin given during lung transplant and compared the rates of intraoperative blood transfusions and the occurrence of thromboembolism between groups. When compared to the very low-intensity group, each higher intensity group was associated with higher red blood cell, fresh frozen plasma, and platelet transfusions. The occurrence of thromboembolism was similar across groups. These preliminary data suggest that lower intensity anticoagulation may reduce the rate of intraoperative blood transfusions, although further study is needed.

The Association of Post-Lung Transplant Pulmonary Embolism With the Development of Chronic Lung Allograft Dysfunction

Background

Pulmonary embolism (PE) is a rare yet serious postoperative complication for lung transplant recipients (LTRs). The association between timing and severity of PE and the development of chronic allograft lung dysfunction (CLAD) has not been described.

Methods

A single-center, retrospective cohort analysis of first LTRs included bilateral or single lung transplants and excluded multiorgan transplants and retransplants. PEs were confirmed by computed tomography angiography or ventilation/perfusion (VQ) scans. Infarctions were confirmed on computed tomography angiography by a trained physician. The PE severity was defined by the Pulmonary Embolism Severity Index (PESI) score, a 30-d post-PE mortality risk calculator, and stratified by low I and II (0-85), intermediate III and IV (85-125), and high V (>125). PE and PESI were analyzed in the outcomes of overall survival, graft failure, and chronic lung allograft dysfunction (CLAD).

Results

We identified 57 of 928 patients (6.14%) who had at least 1 PE in the LTR cohort with a median follow-up of 1623 d. In the subset with PE, the median PESI score was 85 (75.8-96.5). Most of the PESI scores (32/56 available) were in the low-risk category. In the CLAD analysis, there were 49 LTRs who had a PE and 16 LTRs (33%) had infarction. When treating PE as time-dependent and adjusting for covariates, PE was significantly associated with death (hazard ratio [HR] 1.8; 95% confidence interval [CI], 1.3-2.5), as well as increased risk of graft failure, defined as retransplant, CLAD, or death (HR 1.8; 95% CI, 1.3-2.5), and CLAD (HR 1.7; 95% CI, 1.2-2.4). Infarction was not associated with CLAD or death. The PESI risk category was not a significant predictor of death or CLAD.

Conclusions

PE is associated with decreased survival and increased hazard of developing CLAD. PESI score was not a reliable predictor of CLAD or death in this lung transplant cohort.

Limited Effect of Prevention Strategies on Incidence of Clinically Detectable Venous Thromboembolism After Lung Transplantation

BACKGROUND

Thromboembolic complications are common post-lung transplant, leading to significant morbidity. We instituted multiple interventions because of an observed 36.8% incidence of venous thromboembolism (VTE) (Incidence rate (IR) 5.74/1000 pt days) in our recipients.

METHODS

Our initiative commenced January 2015 with enoxaparin initiation within 6-8 hours of intensive care unit arrival and continuation for 4-6 weeks. We evaluated the IR of VTE in lung transplant recipients within 90 days of transplant. In 2017, the protocol was modified to extend the time to initiation of prophylaxis to within 72 hours of ICU arrival. In 2019, we further amended our intraoperative vascular access strategy.

RESULTS

Eighteen of 26 lung transplant recipients (LTR) met inclusion criteria in the 2015 cohort. Six of 18 (33.3%) developed VTE, 50% of which were upper extremity (UE), line associated. Fifty two of 75 LTR were eligible for enoxaparin prophylaxis in the 2017 cohort. Fifteen of 52 subjects (28.8%) developed VTE, 77.8% of which were UE and line associated. Despite improved adherence in 2017, there was little change in VTE IR (3.90/1000 pt days compared with 3.85/1000 pt days). Twenty six of 43 LTR met protocol inclusion criteria in the 2019 cohort. Ten subjects (38.5%) developed VTE, 67% of which were UE and line associated (IR 5.18/1000 pt days).

CONCLUSION

Our prospective study found that LTR remain at high risk for VTE despite aggressive prophylaxis with 4-6 weeks of enoxaparin and adjustment of vascular access approach. Alternative interventions should be investigated to minimize VTE development in this vulnerable population.

Alterations in Pulmonary Physiology with Lung Transplantation

Lung transplant is a treatment option for patients with end-stage lung diseases; however, survival outcomes continue to be inferior when compared to other solid organs. We review the several anatomic and physiologic changes that result from lung transplantation surgery, and their role in the pathophysiology of common complications encountered by lung recipients. The loss of bronchial circulation into the allograft after transplant surgery results in ischemia-related changes in the bronchial artery territory of the allograft. We discuss the role of bronchopulmonary anastomosis in blood circulation in the allograft posttransplant. We review commonly encountered complications related to loss of bronchial circulation such as allograft airway ischemia, necrosis, anastomotic dehiscence, mucociliary dysfunction, and bronchial stenosis. Loss of dual circulation to the lung also increases the risk of pulmonary infarction with acute pulmonary embolism. The loss of lymphatic drainage during transplant surgery also impairs the management of allograft interstitial fluid, resulting in pulmonary edema and early pleural effusion. We discuss the role of lymphatic drainage in primary graft dysfunction. Besides, we review the association of late posttransplant pleural effusion with complications such as acute rejection. We then review the impact of loss of afferent and efferent innervation from the allograft on control of breathing, as well as lung protective reflexes. We conclude with discussion about pulmonary function testing, allograft monitoring with spirometry, and classification of chronic lung allograft dysfunction phenotypes based on total lung capacity measurements. We also review factors limiting physical exercise capacity after lung transplantation, especially impairment of muscle metabolism. © 2023 American Physiological Society. Compr Physiol 13:4269-4293, 2023.

Influences of Antithrombotic Elastic Socks Combined with Air Pressure in Reducing Lower Extremity Deep Venous Thrombosis for Patients Undergoing Cardiothoracic Surgery

This study was designed to investigate the application and therapeutic effect of antithrombotic elastic socks combined with air pressure in the prevention of lower extremity deep venous thrombosis in patients undergoing cardiothoracic surgery. Sixty patients in cardiothoracic surgery of our hospital from January 2019 to December 2020 were randomly divided into a study group and control group. The control group was treated with routine treatment intervention. Based on routine treatment intervention, the study group was treated with antithrombotic elastic socks combined with pneumatic treatment intervention. The activated partial thromboplastin time (APTT), thrombin time (TT), femoral venous blood flow velocity of both lower limbs, and the incidence of lower extremity deep venous thrombosis (LEDVT), postoperative lower extremity swelling, inflammatory factors, and satisfaction were measured. After intervention, APTT (31.74 ± 1.15 s) and TT (14.58 ± 0.24 s) in the study group were higher than those in the control group APTT (25.13 ± 1.14 s) and TT (12.14 ± 0.23 s) (P < 0.05). The left lower limb femoral vein blood flow velocity and the right lower limb femoral vein blood flow velocity in the study group were better than those in the control group (P < 0.05). The incidence of postoperative lower limb swelling and deep vein in the study group was lower than that in the control group (P < 0.05). Serum tumor necrosis factor alpha and interleukin-6 concentrations in the study group were lower than those in the control group (P < 0.05). The satisfaction rate of patients in the study group (93.33%) was significantly higher than that in the control group (70.00%) (P < 0.05). In conclusion, after cardiothoracic surgery, antithrombotic elastic socks combined with air pressure can significantly reduce the incidence of LEDVT by improving patients' coagulation function, reducing inflammatory reaction. It is worthy of popularization and application in relevant surgery.

Postoperative management of children after lung transplantation

Pediatric lung transplantation is a highly specialized treatment option at a select few hospitals caring for children. Advancements in surgical and medical approaches in the care of these children have improved their care with only minimal improvement in outcomes which remain the lowest of all solid organ transplants. A crucial time period in the management of these children is in the perioperative period after performance of the lung transplant. Supporting allograft function, preventing infection, maintaining fluid balance, achieving pain control, and providing optimal respiratory support are all key factors required for this highly complex pediatric patient population. We review commonly encountered complications that these patients often experience and provide strategies for management.

Early Postoperative Management of Lung Transplant Recipients

The early postoperative period after lung transplantation is a critical time. Prompt recognition and treatment of primary graft dysfunction can alter long-term allograft function. Cardiovascular, gastrointestinal, renal, and hematologic derangements are common and require close management to limit their negative sequelae.

Safety of direct oral anticoagulants in solid organ transplant recipients: A meta-analysis

There is limited evidence comparing direct oral anticoagulants (DOACs) and warfarin in solid organ transplant (SOT) recipients. We performed a pooled analysis to study the safety and efficacy of DOACs in this patient population. We searched PubMed, Embase, and Scopus databases using the search terms "heart transplant" or "lung transplant" or "liver transplant" or "kidney transplant" or "pancreas transplant" and "direct oral anticoagulant" for literature search. Random effects model with Mantel-Haenszel method was used to pool the outcomes. Pooled analysis included 489 patients, of which 259 patients received DOACs and 230 patients received warfarin. When compared to warfarin, the use of DOACs was associated with decreased risk of composite bleed (RR .49, 95% CI .32-.76, p = .002). There were no differences in rates of major bleeding (RR .55, 95% CI .20-1.49, p = .24) or venous thromboembolism (RR .65, 95% CI .25-1.70, p = .38) between the two groups. Evidence from pooled analysis suggests that DOACs are comparable to warfarin in terms of safety in SOT recipients. Further research is warranted to conclusively determine whether DOACs are safe alternatives to warfarin for anticoagulation in SOT recipients.

Complications of Lung Transplantation: Update on Imaging Manifestations and Management

As lung transplantation has become the most effective definitive treatment option for end-stage chronic respiratory diseases, yearly rates of this surgery have been steadily increasing. Despite improvement in surgical techniques and medical management of transplant recipients, complications from lung transplantation are a major cause of morbidity and mortality. Some of these complications can be classified on the basis of the time they typically occur after lung transplantation, while others may occur at any time. Imaging studies, in conjunction with clinical and laboratory evaluation, are key components in diagnosing and monitoring these conditions. Therefore, radiologists play a critical role in recognizing and communicating findings suggestive of lung transplantation complications. A description of imaging features of the most common lung transplantation complications, including surgical, medical, immunologic, and infectious complications, as well as an update on their management, will be reviewed here. Keywords: Pulmonary, Thorax, Surgery, Transplantation Supplemental material is available for this article. © RSNA, 2021.

Venous thromboembolism in lung transplant recipients real world experience from a high volume center

BACKGROUND

Venous thromboembolism (VTE) post lung transplantation is common and has been associated with worse post transplant survival. We report a comprehensive single center review of VTE incidence in the first post transplant year, investigate modifiable risk factors and assess impact on short term outcomes.

METHODS

Retrospective review of all lung transplant recipients between August 2016 to 2018 at Temple University Hospital. Patients were followed for 1 year post transplant. All patients were screened for deep venous thrombosis (DVT) within the first 2 weeks with a venous duplex study. Pre transplant, intra operative, post operative variables, and peri-operative practice patterns were compared between VTE positive and VTE negative groups. Logistic regression modeling was used to identify risk factors for early VTE (VTE within 30 days after transplant).

RESULTS

A total of 235 patients were included in the study, 58 patients (24.7%) developed a VTE in the first post transplant year. Median time to diagnosis was 17 days. Of the patients with VTE, 76% had an isolated DVT, 13.5 % had an isolated pulmonary embolism (PE), and 10.3% had concomitant DVT and PE. In a multivariate logistic regression model, cardiopulmonary bypass (CPB) (OR 1.93 p = 0.015) and interruption of VTE prophylaxis (OR 4.42 p < 0.0001) were predictive of early VTE.

CONCLUSION

VTE post lung transplant is common despite the use of prophylactic anticoagulation. CPB use and interruption of DVT prophylaxis are risk factors for early post transplant VTE. Measures to ensure consistent and uninterrupted prophylaxis may help decrease VTE incidence after lung transplantation.

Early postoperative complications in lung transplant recipients

Lung transplantation has become an established therapy for end-stage lung diseases. Early postoperative complications can impact immediate, mid-term, and long-term outcomes. Appropriate management, prevention, and early detection of these early postoperative complications can improve the overall transplant course. In this review, we highlight the incidence, detection, and management of these early postoperative complications in lung transplant recipients.

Cell-free DNA beyond a biomarker for rejection: Biological trigger of tissue injury and potential therapeutics

Cell-free DNA, measured as donor-derived cell-free DNA is developed as a non-specific biomarker for allograft injury and transplant rejection. However, cell-free DNA characteristics are more specific, its fragment length, nucleotide content, and composition, as well as the tissue source of origin, are intrinsically linked to the underlying disease pathogenesis, showing distinct features in acute cellular rejection and antibody-mediated rejection for example. Further, cell-free DNA and cell-free mitochondrial DNA can directly trigger tissue injury as damage-associated molecular patterns through three major intracellular receptors, toll-like receptor 9 , cyclic guanosine monophosphate-adenosine monophosphate synthase, and inflammasomes (i.e., absent in melanoma 2: AIM2). Therefore, in addition to its role as a non-specific marker for allograft injury, cell-free DNA analysis may be used to phenotype transplant rejection, and to non-invasively point the underlying molecular mechanisms with allograft injury. Novel treatment approaches targeting these cell-free DNA pathways may be useful to treat transplant rejection and prevent end-organ dysfunction. In this review, we discuss the link between cell-free DNA characteristics and disease, the role of cell-free DNA as a damage-associated molecular pattern, and novel therapeutics targeting these cell-free DNA molecular pathways and their potential utility to treat transplant rejection.

Comparison of mechanical cardiopulmonary support strategies during lung transplantation

INTRODUCTION

Lung transplantation outcomes are influenced by the intraoperative mechanical cardiopulmonary support strategy used. This surgery was historically done either on cardiopulmonary bypass (CPB) or off pump. Recently, there has been increased interest in intraoperative support with veno-arterial (VA) or veno-venous (VV) extracorporeal membrane oxygenation (ECMO). However, there is a lack of consensus on the relative risks, benefits and indications for each intraoperative support strategy.

AREAS COVERED

This review includes information from cohort studies, case-control studies, and case series that compare morbidity and/or mortality of two or more intraoperative cardiopulmonary support strategies during lung transplantation.

EXPERT OPINION

The optimal strategy for intraoperative cardiopulmonary support during lung transplantation remains an area of debate. Current data suggest that off pump is associated with better outcomes and could be considered whenever feasible. ECMO is generally associated with preferable outcomes to CPB, but the data supporting this association is not robust. Interestingly, whether CPB is unplanned or prolonged might influence outcomes more than the use of CPB itself. These observations can help guide surgical teams in their approach for intraoperative mechanical support strategy during lung transplantation and should serve as the basis for further investigations.

Characteristics and Outcomes Among Patients With Early Venous Thromboembolic Events After Lung Transplant

BACKGROUND

Despite several previous studies reporting a high frequency of venous thromboembolism (VTE) after lung transplant (LT), few actionable risk factors have been identified. There are limited data regarding the practice patterns of anticoagulation use among patients with LT.

METHODS

All adult patients with single or bilateral LT between 2012 and 2016 were included (n = 324; mean age, 56.3 ± 13.3 years; male, 61.1%). Demographic, clinical, and laboratory variables before and after LT were recorded. Follow-up data included survival up to 3 years post-transplant. Development of VTE during the first 30 days after LT was the primary outcome variable.

RESULTS

The overall incidence of VTE during the first 30 days after LT was 29.9% (n = 97), among which the majority were upper extremity thromboses. Female sex, personal history of VTE, hospitalization at the time of transplant, and use of 3 or more central venous catheters during index hospitalization were independently associated with VTE. The use of anticoagulants was independently associated with a reduced risk of VTE. Despite increased morbidity, the development of VTE was not associated with worse post-transplant survival.

CONCLUSIONS

A significant proportion of patients develop early VTE after LT. Limiting the number of central catheters to < 3 during the post-transplant period, along with the early institution of thromboprophylaxis, may lower the risk of VTE.

Routine deep vein thrombosis screening after lung transplantation: Incidence and risk factors

BACKGROUND

Deep vein thrombosis (DVT) remains a common complication following lung transplantation despite universal routine DVT screening. Moreover, many of the previously reported risk factors are incompletely defined. We sought to explore the influence of DVT screening and to more definitively assess predisposing risk factors.

METHODS

A single-institution, retrospective, cohort study of 1141 patients undergoing lung transplantation from January 1, 2005, to December 31, 2014, was performed evaluating for the rate of DVT. Patients were given prophylactic subcutaneous heparin postoperatively. DVT events were noted if they occurred before 90 days after transplant. We compared DVT rates before and after 2008 when universal screening was implemented. We also evaluated the timing of DVT event and location (above the knee vs below the knee). DVTs were treated with standard anticoagulation therapy or an inferior cava filter when patients were unable to tolerate anticoagulation treatment. Univariable and multivariable models were used to identify risk factors for occurrence. A propensity match was performed to match groups across the eras, and a Cox regression was performed to identify differences in 1-year survival trajectory between cohorts.

RESULTS

The rates of DVT before and after routine screening were 8.8% (36 DVT out of 412 transplants) and 17.3% (126 out of 729 transplants), respectively. These 2 rates were significantly different (P < .01); moreover, the observed DVT incidence per year was not significantly different across the 6 years after universal DVT screening was implemented (P > .90 for all comparisons). Observed DVT incidence at day 0 and day 14 were 3.8% and 3.8%, respectively, for the cohort before DVT protocols were established. Observed DVT incidence for the cohort after protocols were established at the same time points was 8.7% and 3.7%, respectively. Univariable analysis revealed that significant factors associated with a DVT include hypercholesterolemia (odds ratio [OR], 6.90; 95% confidence interval [CI], 1.82-26.13; P < .01), the number of days in the intensive care unit (OR, 1.03; 95% CI, 1.00-1.01; P < .01), and the length of stay in the hospital (OR, 1.01; 95% CI, 1.01-1.02; P < .01), whereas having quit smoking (vs never smoked) was associated with a decrease in DVT development (OR, 0.50; 95% CI, 0.33-0.75; P < .01). Multivariable analysis revealed 2 significant variables: hypercholesterolemia (OR, 8.13; 95% CI, 1.22-54.37; P = .03) and length of stay (OR, 1.03; 95% CI, 1.01-1.05; P < .01). There was a trend for better 1-year survival in the post-2008 era (Exp[β], 1.49; P = .09).

CONCLUSIONS

The rate of DVT diagnosis significantly increased after universal DVT screening was implemented. Furthermore, those patients undergoing lung transplantation with extended length of stay and hypercholesterolemia were prone to increased rates of DVT. There was a trend toward better 1-year survival in DVT-screened patients, suggesting DVT screening may result in beneficial outcomes.

Venous Thromboembolism After Adult Lung Transplantation: A Frequent Event Associated With Lower Survival

BACKGROUND

The incidence of venous thromboembolism (VTE) after lung transplantation (LTX) varies significantly across studies. Two studies have suggested that these thrombotic events are associated with a lower posttransplant survival. Herein, we sought to determine the incidence, predictors, and impact of VTE on survival after LTX at a quaternary referral center.

METHODS

This was a large cohort study of LTX recipients. Key outcome parameters were time to VTE after transplant and survival. Deep vein thrombosis (DVT) diagnosis required a positive ultrasound. Pulmonary embolism diagnosis required either a positive chest computed tomography angiogram or a high-probability ventilation/perfusion scan.

RESULTS

The overall incidence of VTE among 701 LTX recipients was 43.8%, of which 97.7% were DVT episodes, of which 71.3% were in the upper extremities. Predictors of VTE were prior history of DVT (hazard ratio [HR], 2.82; 95% confidence interval [CI], 1.49-5.37), days in intensive care (HR, 1.01; 95% CI, 1.01-1.02), and the use of extracorporeal membrane oxygenation (HR, 2.22; 95% CI, 1.43-3.45). Importantly, VTE predicted a lower posttransplant survival (HR, 1.70; 95% CI, 1.28-2.26), when occurring within or after the first 30 days. The location of the DVT, either upper extremity or below the knee, also predicted a poor survival.

CONCLUSIONS

VTE was frequent in LTX recipients and predicted a poor survival even when located in the upper extremities or below the knee. These data suggest that aggressive VTE screening/treatment protocols be implemented in post-LTX population.

Medical Course and Complications After Lung Transplantation

Lung transplant prolongs life and improves quality of life in patients with end-stage lung disease. However, survival of lung transplant recipients is shorter compared to patients with other solid organ transplants, due to many unique features of the lung allograft. Patients can develop a multitude of noninfectious (e.g., primary graft dysfunction, pulmonary embolism, rejection, acute and chronic, renal insufficiency, malignancies) and infectious (i.e., bacterial, fungal, and viral) complications and require complex multidisciplinary care. This chapter discusses medical course and complications that patients might experience after lung transplantation.

Ventilation perfusion pulmonary scintigraphy in the evaluation of pre-and post-lung transplant patients

Lung transplantation is an established treatment for patients with a variety of advanced lung diseases. Imaging studies play a valuable role not only in evaluation of patients prior to lung transplantation, but also in the follow up of patients after transplantation for detection of complications. After lung transplantation, complications can occur as a result of surgical procedure, pulmonary embolism and ultimately chronic lung allograft dysfunction. Lung scintigraphy, which includes physiologic assessment of lung ventilation and perfusion by imaging, has become an important procedure in the evaluation of these patients, assuming a complementary role to high resolution anatomic imaging (computed tomography [CT]), as well as spirometry. The purpose of this atlas article is to demonstrate the uses of ventilation perfusion scintigraphy in the pre-transplantation setting for surgical planning and in the evaluation of complications post-lung transplantation based upon experience at our institution.

Cardiovascular disease risk in patients receiving organ transplantation: a national cohort study

Although organ transplantation is the definitive treatment for end-stage organ failure, the post-transplant outcomes can be substantially influenced by cardiovascular complications. A national cohort study was performed to estimate risks of cardiovascular diseases in those with heart, lung, kidney, and liver transplantation. This cohort study consisted of 5978 solid organ transplantations identified using the Taiwan National Health Insurance Database. Cardiovascular and mortality risks in transplant recipients were evaluated using standardized incidence ratios, excess absolute risks, and standardized mortality ratios as compared to those in the general population. In heart, kidney, and liver recipients, the standardized incidence ratios of overall cardiovascular diseases were 9.41 (7.75-11.44), 3.32 (2.29-3.77), and 1.4 (1.15-1.7) and the overall standardized mortality ratios were 5.23 (4.54-6.03), 1.48 (1.34-1.63), and 3.95 (3.64-4.28), respectively. Except for heart organ recipients who were at highest risk for coronary artery disease with a standardized incidence ratio of 13.12 (10.57-16.29), kidney and liver organ recipients had a ninefold increased risk in developing deep vein thrombosis post-transplant. In conclusion, solid organ transplant patients are at risk of cardiovascular disease, in particular, deep vein thrombosis, which may warrant early identification of high-risk patients in addition to prompt and adequate thromboprophylaxis perioperatively.

Early postoperative management after lung transplantation: Results of an international survey

INTRODUCTION

Little data exist regarding optimal therapeutic strategies postoperatively after lung transplant (LTx). Current practice patterns rely on expert opinion and institutional experience resulting in nonuniform postoperative care. To better define current practice patterns, an international survey of LTx clinicians was conducted.

METHODS

A 30-question survey was sent to transplant clinicians via email to the International Society of Heart and Lung Transplantation open forum mailing list and directly to the chief transplant surgeon and pulmonologist of all LTx centers in the United States.

RESULTS

Fifty-two clinicians representing 10 countries responded to the survey. Sedatives use patterns included: opiates + propofol (57.2%), opiates + dexmedetomidine (18.4%), opiates + intermittent benzodiazepines (14.3%), opiates + continuous benzodiazepines (8.2%), and opiates alone (2%). About 40.4% reported no formal sedation scale was followed and 13.5% of programs had no formal policy on sedation and analgesia. A lung protective strategy was commonly employed, with 13.8%, 51.3%, and 35.9% of respondents using tidal volumes of <6 mL/kg ideal body weight (IBW), 6 mL/kg IBW, and 8 mL/kg IBW, respectively.

CONCLUSION

Practice patterns in the early postoperative care of lung transplant recipients differ considerably among centers. Many of the reported practices do not conform to consensus guidelines on management of critically ill patients.