Anti-Thymocyte Globulin as a Therapy for Chronic Lung Allograft Dysfunction: A Single-Center Experience.

INTRODUCTION: Anti-thymocyte globulin (ATG) is a polyclonal antibody formulation which has been used as a second-line therapy for chronic lung allograft dysfunction (CLAD). Limited data exist evaluating its efficacy; however, several single-center retrospective studies have variably demonstrated either improvement or stabilization of spirometry parameters after administration of ATG. ATG has been in use at UT Southwestern for treatment of CLAD since at least 2010; here, we seek to evaluate the effectiveness of this intervention at our center.  METHODS: A retrospective chart review was conducted of a total of 136 patients who underwent lung transplantation at UT Southwestern Medical Center between 2010 and 2022. Of these, 72 patients had received ATG specifically for treatment of CLAD, and the remaining 64 had never received ATG. Two separate analyses were performed: in the first, among those who received ATG for CLAD, spirometry data from the 6 months preceding and following ATG administration were reviewed and rates of change in FEV1 were calculated for each time period. Descriptive statistics were performed to summarize the baseline clinical characteristics and outcomes after ATG, with patients classified as having either a full response (positive rate of change in FEV1) or partial response (>20% attenuation in rate of FEV1 decline) to ATG.  In the second analysis, survival was described among those who received ATG for CLAD and comparison was provided between propensity-score matched cohorts from the ATG and non-ATG groups. RESULTS: Of the 63 patients who received ATG for treatment of CLAD (and had adequate spirometry measurements available to trend FEV1), 49 (77.8%) had at least a partial response to therapy; 8 (12.7%) experienced an overall improvement in FEV1. Response to ATG was found to be associated with a more rapid rate of pre-ATG decline in FEV1; no other baseline parameters were found to be predictive of a response to ATG. Median post-CLAD graft survival was 31.7 months among those who received ATG, and only baseline absolute neutrophil count was found to be associated with worse post-CLAD graft survival among this group. CONCLUSION: Anti-thymocyte globulin therapy, when given for CLAD, was associated with at least a modest attenuation in rate of FEV1 decline in most patients but only rarely preceded an absolute improvement in FEV1. Further study is warranted to better define the role for ATG in treatment of CLAD, a challenging disease state with limited therapeutics available.

Impact of cerebrovascular accidents on lung transplant survival.

BACKGROUND: Cerebrovascular accidents (CVA) are a source of postoperative morbidity. Existing data on CVA after lung transplantation (LT) are limited. We aimed to evaluate the impact of CVA on LT survival. METHODS: A retrospective analysis of LT recipients at the University of Texas Southwestern Medical Center was performed. Data was obtained from the institutional thoracic transplant database between January 2012 and December 2018, which consisted of 476 patients. Patients were stratified by the presence of a postoperative CVA. Univariate comparisons of baseline characteristics, operative variables, and postoperative outcomes between the cohorts were performed. Survival was analyzed by Kaplan-Meier method. Aalen's additive regression model was utilized to assess mortality hazard over time. RESULTS: The incidence of CVA was 4.2% (20/476). Lung allocation score was higher in the CVA cohort (46.2 [41.7, 57.3] vs. 41.5 [35.8, 52.2], p = 0.04). There were no significant differences in operative variables. CVA patients had longer initial intensive care unit (ICU) stays (316 h [251, 557] vs. 124 [85, 218], p < 0.001) and longer length of stay (22 days [17, 53] vs. 15 [11, 26], p = 0.007). CVA patients required more ICU readmissions (35% vs. 15%, p = 0.02) and had a lower rates of home discharge (35% vs. 71%, p < 0.001). Thirty-day mortality was higher in the CVA cohort (20% vs. 1.3%, p < 0.001). Overall survival was lower in the CVA cohort (log rank p = 0.044). CONCLUSIONS: Postoperative CVA following LT was associated with longer ICU stays, more ICU readmissions, longer length of stay, and fewer home discharges. Thirty day and long-term mortality were significantly higher in the CVA group.

Clinical outcomes of patients with and without chronic kidney disease undergoing endovascular revascularization of infrainguinal peripheral artery disease: Insights from the XLPAD registry.

OBJECTIVES: The purpose of the present study was to define clinical outcomes of chronic kidney disease (CKD) patients undergoing endovascular revascularization of infrainguinal peripheral artery disease (PAD). BACKGROUND: CKD is an established predictor of advanced PAD. However, clinical outcomes for these patients following endovascular revascularization remain inadequately defined. METHODS: Using the ongoing multicenter Excellence in Peripheral Artery Disease (XLPAD) registry (NCT01904851), we analyzed all-cause death, target limb amputation, and need for repeat revascularization for patients with and without CKD undergoing infrainguinal endovascular revascularization between the years 2005 and 2018. RESULTS: Of 3,699 patients, 15.1% (n = 559) had baseline CKD. CKD patients had significantly higher incidence of heavily calcified lesions (48.4% vs. 38.1%, p < .001) and diffuse disease (66.9% vs. 61.5%, p = .007). Kaplan-Meier analysis showed significant differences between CKD and non-CKD patient outcomes at 12 months for freedom from target limb amputation (79.9% vs. 92.7%, p < .001) and all-cause death (90.1% vs. 97.6%, p < .001). However, freedom from target vessel revascularization was similar between the groups. After adjusting for baseline comorbidities in the CKD and non-CKD groups, the hazard ratios for target limb amputation and death at 12 months were 2.28 (95% confidence interval or CI 1.25-4.17, p < .001) and 4.38 (95% CI 2.58-7.45, p < .001), respectively. CONCLUSIONS: Following endovascular revascularization for infrainguinal PAD, CKD was an independent predictor of all-cause death and target limb amputation at 12 months.

Acute Kidney Injury in Patients Undergoing Cardiopulmonary Bypass for Lung Transplantation.

BACKGROUND: Cardiopulmonary bypass (CPB) is often used to support patients undergoing lung transplantation who are intolerant of anatomic manipulation or single lung ventilation during the procedure. However, CPB may be associated with adverse outcomes. We evaluated the hypothesis that CPB is associated with increased acute kidney injury (AKI) and postoperative mortality after lung transplantation. MATERIALS AND METHODS: This was a retrospective review of our institutional lung transplant database at the University of Texas Southwestern Medical Center from 2012 to 2018. Patients were grouped based on their need for CPB. The primary outcome was AKI within 48 h of transplantation, which was defined as Kidney Disease Improving Global Outcomes stage 1 or greater. Secondary outcomes included all-cause mortality. RESULTS: A total of 426 patients underwent lung transplantation with 39.0% (n = 166) requiring CPB. There were no differences in demographics and comorbidities, including baseline renal function, between CPB and no CPB. CPB use was higher in recipients with interstitial lung diseases and primary pulmonary hypertension. Median lung allocation score was higher in those needing CPB (47 [interquartile range, 40-59] versus 39 [interquartile range, 35-47]). Patients requiring CPB were significantly more likely to experience AKI (61.44% versus 36.5.3%, P < 0.01) and postoperative hemodialysis (6.6% versus 0.4%, P < 0.01). On multivariable analysis, CPB was significantly associated with postoperative AKI (odds ratio, 1.66; 95% CI, 1.01-2.75; P = 0.04). Thirty-day mortality was higher in patients undergoing CPB (4.2% versus 0.8%, P = 0.03). CONCLUSIONS: CPB for lung transplantation is associated with a higher incidence of AKI, renal failure requiring hemodialysis, and 30-d mortality. CPB should be used selectively for lung transplantation.

Incidence and variables associated with 30-day mortality after lung transplantation.

BACKGROUND: With the introduction of the lung allocation score (LAS), sicker patients are prioritized for lung transplantation (LT). There is a lack of data regarding variables independently associated with 30-day mortality after LT. METHODS: We queried the UNOS database for adult patients undergoing LT between 1989 and 2014. Patients with dual organ or previous transplantation and those with missing survival data were excluded. Mortality during the first 30 days after LT was the primary outcome variable. RESULTS: The yearly trends indicate a statistically significant reduction in the 30-day mortality during the study period (P < 0.001, overall mortality: 5.5%) which has continued in the post-LAS era (P = 0. 014, overall mortality: 3.6%). Among patients with 30-day mortality, "primary non-function" (n = 118, 72.8%) was reported as the most common etiology. Transplant indication of vascular diseases, history of non-transplant cardiac or lung surgery, mean pulmonary pressures >35 mm Hg, disabled functional status, ECMO support, high LAS, ischemic time >6 hours, and blunt injury as the mechanism of donor death are independently associated with 30-day mortality. CONCLUSION: The incidence of early mortality after LT continues to decline in the post-LAS era. Apart from the mechanism of donor death and ischemic time, early mortality appears to be primarily driven by the recipient characteristics.

Packed red blood cell transfusion associates with acute kidney injury after transcatheter aortic valve replacement.

BACKGROUND: Acute kidney injury after cardiac surgery significantly associates with morbidity and mortality. Despite not requiring cardiopulmonary bypass, transcatheter aortic valve replacement patients have an incidence of post-procedural acute kidney injury similar to patients who undergo open surgical aortic valve replacement. Packed red blood cell transfusion has been associated with morbidity and mortality after cardiac surgery. We hypothesized that packed red blood cell transfusion independently associates with acute kidney injury after transcatheter aortic valve replacement, after accounting for other risk factors. METHODS: This is a single-center retrospective cohort study of 116 patients undergoing transcatheter aortic valve replacement. Post-transcatheter aortic valve replacement acute kidney injury was defined by Kidney Disease: Improving Global Outcomes serum creatinine-based criteria. Univariate comparisons between patients with and without post-transcatheter aortic valve replacement acute kidney injury were made for clinical characteristics. Multivariable logistic regression was used to assess independent association of packed red blood cell transfusion with post-transcatheter aortic valve replacement acute kidney injury (adjusting for pre-procedural renal function and other important clinical parameters). RESULTS: Acute kidney injury occurred in 20 (17.2%) subjects. Total number of packed red blood cells transfused independently associated with post-procedure acute kidney injury (OR = 1.67 per unit, 95% CI 1.13-2.47, P = 0.01) after adjusting for pre-procedure estimated glomerular filtration rate (OR = 0.97 per ml/min/1.73m2, 95% CI 0.94-1.00, P = 0.05), nadir hemoglobin (OR = 0.88 per g/dL increase, CI 0.61-1.27, P = 0.50), and post-procedure maximum number of concurrent inotropes and vasopressors (OR = 2.09 per inotrope or vasopressor, 95% CI 1.19-3.67, P = 0.01). CONCLUSION: Packed red blood cell transfusion, along with post-procedure use of inotropes and vasopressors, independently associate with acute kidney injury after transcatheter aortic valve replacement. Further studies are needed to elucidate the pathobiology underlying these associations.

Lung transplantation: how we do it.

Lung transplantation is considered the gold standard for patients with chronic end-stage pulmonary disease. However, due to the complexity of management and relatively lower median survival as compared to other solid organs, many programs across the world have been slow to adopt the same. In our institution, we started lung transplantation in September 1990. And since then, we performed close to 900 lung transplantations. Here, we describe in detail the operative steps adopted in our institution for a successful lung transplantation. There have been very few variations over the years. We believe that having a standardized technique is one of the important features for success of a lung transplant program.

Ex vivo lung perfusion: how we do it.

Lung transplantation is an established treatment for patients with end-stage lung disease. However, a shortage of donors, low lung utilization among potential donors, and waitlist mortality continue to be challenges. In the last decade, ex vivo lung perfusion (EVLP) has expanded the donor pool by allowing prolonged evaluation of marginal donor lungs and allowing reparative therapies for lungs, which are otherwise considered not transplantable. In this review, we describe in detail our experience with EVLP including our workflow, setup, operative technique, and protocols. Our multidisciplinary EVLP program functions with the collaboration of surgeons, pulmonologists, and EVLP nurses who run the pump. EVLP program has been a valuable addition to our program. Since Food and Drug Administration (FDA) approval in 2019, we experienced incremental increased lung transplant volume of 12% annually.

Percutaneous Aspiration for Septic Thrombi in Burn Patients.

Therapeutic interventions are limited for high-risk burn patients with caval and intracardiac septic thrombi. Percutaneous thrombectomy represents a less invasive alternative to median sternotomy. However, there is limited literature on application of this approach and outcomes in these patients. We report two cases of patients with large total body surface area burns with similar caval and right intracardiac septic thrombi. Both patients were successfully treated using a percutaneous aspiration device.

Expansion of TAVR into Low-Risk Patients and Who to Consider for SAVR.

Transcatheter aortic valve replacement (TAVR) has revolutionized the treatment of severe aortic stenosis (AS) over the last decade. The results of the Placement of Aortic Transcatheter Valves (PARTNER) 3 and Evolut Low Risk trials demonstrated the safety and efficacy of TAVR in low-surgical-risk patients and led to the approval of TAVR for use across the risk spectrum. Heart teams around the world will now be faced with evaluating a deluge of younger, healthier patients with severe AS. Prior to the PARTNER 3 and Evolut Low Risk studies, this heterogenous patient population would have undergone surgical aortic valve replacement (SAVR). It is unlikely that TAVR will completely supplant SAVR for the treatment of severe AS in patients with a low surgical risk, as SAVR has excellent short- and long-term outcomes and years of durability data. In this review, we outline the critical role that SAVR will continue to play in the treatment of severe AS in the post-PARTNER 3/Evolut Low Risk era.

Saved by the VAC: Minimally Invasive Removal of a Surely Fatal Right Heart Thrombus in a Patient with Advanced Heart Failure.

Intracardiac thrombi are associated with an increased morbidity and mortality due to their unpredictability and embolic potential. Right heart thrombus is infrequently encountered in clinical practice outside the scenario of acute pulmonary embolism with hemodynamic compromise, and even more uncommon is the presence of a massive right heart thrombus. Embolic potential is high, and historically, management has revolved around open surgical removal or systemic thrombolysis. We hereby present a case of a massive right heart thrombus in a high surgical risk patient, which was successfully removed using a percutaneous aspiration device.

Telesurgery via Unmanned Aerial Vehicle (UAV) with a field deployable surgical robot.

Robotically assisted surgery stands to further revolutionize the medical field and provide patients with more effective healthcare. Most robotically assisted surgeries are teleoperated from the surgeon console to the patient where both ends of the system are located in the operating room. The challenge of surgical teleoperation across a long distance was already demonstrated through a wired communication network in 2001. New development has shifted towards deploying a surgical robot system in mobile settings and/or extreme environments such as the battlefield or natural disaster areas with surgeons operating wirelessly. As a collaborator in the HAPs/MRT (High Altitude Platform/Mobile Robotic Telesurgery) project, The University of Washington surgical robot was deployed in the desert of Simi Valley, CA for telesurgery experiments on an inanimate model via wireless communication through an Unmanned Aerial Vehicle (UAV). The surgical tasks were performed telerobotically with a maximum time delay between the surgeon's console (master) and the surgical robot (slave) of 20 ms for the robotic control signals and 200 ms for the video stream. This was our first experiment in the area of Mobile Robotic Telesurgery (MRT). The creation and initial testing of a deployable surgical robot system will facilitate growth in this area eventually leading to future systems saving human lives in disaster areas, on the battlefield or in other remote environments.

Transplantation in a patient on extracorporeal membrane oxygenation with infective endocarditis, pericarditis and heparin-induced thrombocytopenia.

Heart failure patients with pacemaker or defibrillator-associated endocarditis in cardiogenic shock have few treatment options. We present a case of an INTERMACS I patient who developed device infection, sepsis, bacterial pericarditis and heparin-induced thrombocytopenia. The patient was stabilized with extracorporeal membrane oxygenation and successfully transplanted.

Ultraportable Oxygen Concentrator Use in U.S. Army Special Operations Forward Area Surgery: A Proof of Concept in Multiple Environments.

INTRODUCTION: A limitation to surgical care in an austere environment is the supply of oxygen to support mechanical ventilation and general anesthesia. Portable oxygen concentrators (OCs) offer an alternative to traditional compressed oxygen tanks. OBJECTIVES: We set out to demonstrate that a low-pressure OC system could supply the mechanical ventilation needs in an austere operating environment. METHODS: An ultraportable OC (SAROS Model 3000, SeQual Technologies, Ball Ground, Georgia) was paired with an Impact 754 ventilator (Impact Instrumentation, West Caldwell, New Jersey) to evaluate the delivered fraction of inspired oxygen (FiO2) to a test lung across a range of minute ventilations and at altitudes of 1,200 and 6,500 feet above sea level. RESULTS: The compressor-driven Impact ventilator was able to deliver FiO2 at close to 0.9 for minute ventilations equal to oxygen flow. Pairing two OCs expanded the range of minute ventilations supported. OCs were less effective at concentrating oxygen at higher altitudes. CONCLUSIONS: These results demonstrate that low-pressure, ultraportable OCs are capable of delivering high FiO2 during mechanical ventilation in austere locations at both low and high altitudes. Ultraportable OCs could therefore be sufficient to support forward area surgical procedures and positively impact logistics.

Hypertrophic obstructive cardiomyopathy: review of surgical treatment.

Hypertrophic cardiomyopathy ranks among the most common congenital cardiac diseases, affecting up to 1 in 200 of the general population. When it causes left ventricular outflow tract obstruction, treatment is guided to reduce symptoms and the risk of sudden cardiac death. Pharmacologic therapy is the first-line treatment, but when it fails, surgical myectomy or percutaneous ablation of the hypertrophic myocardium are the standard therapies to eliminate subaortic obstruction. Both surgical myectomy and percutaneous ablation are proven safe and effective treatments; however, myectomy is the gold standard with a significantly lower complication rate and more complete and lasting reduction of left ventricular outflow tract obstruction.

Contemporary analysis of early outcomes after lung transplantation in the elderly using a national registry.

BACKGROUND: With an increasing number of potential recipients and a comparatively static number of donors, lung transplantation (LT) in the elderly has come under significant scrutiny. Previous studies have been limited by single-center experiences with small population sizes and often mixed results. Using a national registry, we sought to evaluate the following: (1) differences in survival outcomes in septuagenarians compared with sexagenarians; and (2) the effect of temporal trends on the development of other comorbidities in this population. METHODS: We analyzed the Scientific Registry of Transplant Recipients (SRTR) data files from the United Network for Organ Sharing (UNOS) database to identify recipients who underwent LT between the years 2000 and 2013. The study period was divided into two equal eras. Using Kaplan-Meier analysis, we compared the 30-day, 3-month, 1-year, 3-year and 5-year patient survival between septuagenarians and sexagenarians in both eras. Separate multivariate analyses were performed to estimate the risk of renal failure, risk of rejection and length of hospital stay (LOS) post-LT in each of these time periods. RESULTS: A total of 6,596 patients were identified comprising 1,726 (26.2%) during 2000 to 2005 and 4,870 (73.8%) during 2006 to 2012. In the "early era," 32 (1.9%) septuagenarians and 1,694 (98.1%) sexagenarians underwent LT, whereas 543 (11.1%) septuagenarians and 4,327 (88.9%) sexagenarians underwent transplantation in the "latter era." A comparison of patient survival between the two groups in the early era revealed no difference at 30 days (95.7% vs 93.8%, p = 0.65). However, 3-month (91.2% vs 75%, p = 0.04) and 1-year patient survival (79.5% vs 62.5%, p = 0.048) were both lower in the septuagenarian group. In the later era, however, there were no differences in 30-day (96.2% vs 96.8, p = 0.5), 3-month (92.7% vs 91.9%, p = 0.56) or 1-year (81.7% vs 78.6%, p = 0.12) patient survival between the two age groups. Survival rates at 3 years (63.7% vs 49.3%, p < 0.001) and 5 years (47.5% vs 28.2%, p < 0.001) were each significantly lower in the septuagenarian group. CONCLUSION: Overall, LT outcomes for the elderly have improved significantly over time and early outcomes in the modern era rival those found in younger recipients.

Identical tricuspid ring sizing in simultaneous functional tricuspid and mitral valve repair: A simple and effective strategy.

OBJECTIVE: Mitral valve repair for functional mitral regurgitation is common. Concomitant tricuspid valve repair for associated functional tricuspid regurgitation has gained favor. Controversy exists regarding annuloplasty sizing for tricuspid valve repair. METHODS: Patients with heart failure having functional mitral regurgitation at the University of Michigan and undergoing mitral valve repair and tricuspid valve repair using identical sized annuloplasty rings between April 2007 and January 2012 were identified. Demographic and clinical records were retrospectively reviewed. Institutional review board approval was obtained for this study. RESULTS: Fifty-three patients met inclusion criteria. Mean age was 65 ± 1.7 years. Preoperative New York Heart Association class was III or IV in 81% (43) and mean left ventricular ejection fraction was 33% ± 2.2%. All patients had moderate or greater mitral regurgitation preoperatively and moderate or severe tricuspid regurgitation or a preoperative tricuspid annulus diameter greater than 40 mm. There was no 30-day mortality. Mean immediate postoperative tricuspid valve gradient was 1.75 ± 0.12 mm Hg and was 2.3 ± 0.19 mm Hg at 4 weeks. Four weeks postoperatively 88% (42/48) of patients had tricuspid regurgitation considered to be mild or less. There was no significant decline in right ventricular function by echocardiography over this time period. CONCLUSIONS: Functional tricuspid regurgitation can be repaired using an undersized rigid annuloplasty ring. Our data suggest that an identical sizing strategy can be used for tricuspid valve repair, as was used for mitral valve repair, without development of tricuspid stenosis or negative effect on right ventricular function. This method seems to prevent recurrence of significant tricuspid regurgitation. The technique we describe provides effective and reproducible results.

"Prophylactic" tricuspid repair for functional tricuspid regurgitation.

BACKGROUND: The optimal management of functional tricuspid regurgitation (FTR) in the setting of mitral valve operations remains controversial. The objective of this study is to compare the outcomes of congestive heart failure patients who underwent a prophylactic tricuspid operation for FTR as a component of their initial mitral valve procedure with those who underwent a redo tricuspid operation at a later date for residual FTR. METHODS: Patients with FTR repaired as a redo operation between 2004 and 2012 were identified. These patients were propensity-matched 1:2 with contemporaneous patients with FTR or tricuspid dilatation who underwent tricuspid repair at the same time as mitral valve repair. Demographic information, postoperative complications, and short-term and long-term mortality rates were compared between groups. RESULTS: There were 21 patients treated with redo tricuspid valve repair matched with 42 patients treated prophylactically. There were 3 deaths at 30 days in the redo group (14%), compared with zero in the prophylactic group (p=0.03). Overall long-term mortality in the redo group was 29% (6 of 21), with a mean 31 months of follow-up, but was only 14% (6 of 42) in the prophylactic group, with a mean 25 months of follow-up. Kaplan-Meier long-term survival analysis did not reveal a difference between groups (log-rank p=0.37) once the perioperative period was survived. CONCLUSIONS: Redo tricuspid valve repair for residual FTR can be performed with acceptable short-term and long-term mortality. However, treatment of FTR at the time of the initial intervention should be considered, because it is safe and effective. A randomized, controlled trial of prophylactic tricuspid operation for FTR at the time of the mitral operation may be warranted.