Repair of Tracheal Dehiscence After Heart-Lung Transplant Complicated by SARS-CoV-2 Infection.

Airway complications are a major cause of morbidity after thoracic transplantation. Airway ischemia, necrosis, and tracheobronchial anastomotic dehiscence are associated with early mortality. We describe a case of tracheal anastomotic dehiscence after en bloc heart-lung transplant complicated by severe acute respiratory syndrome coronavirus 2 infection. Timely surgical management and reconstruction with a bovine pericardial patch and double muscle flap were performed. After 8 months of follow-up, there are no airway complications and normalized allograft function.

Low molecular weight hyaluronan inhibits lung epithelial ion channels by activating the calcium-sensing receptor.

Herein, we tested the hypothesis that low molecular weight hyaluronan (LMW-HA) inhibits lung epithelial ions transport in-vivo, ex-vivo, and in-vitro by activating the calcium-sensing receptor (CaSR). Twenty-four hours post intranasal instillation of 50-150 µg/ml LMW-HA to C57BL/6 mice, there was a 75% inhibition of alveolar fluid clearance (AFC), a threefold increase in the epithelial lining fluid (ELF) depth, and a 20% increase in lung wet/dry (W/D) ratio. Incubation of human and mouse precision cut lung slices with 150 µg/ml LMW-HA reduced the activity and the open probability (Po) of epithelial sodium channel (ENaC) in alveolar epithelial type 2 (ATII) cells, and in mouse tracheal epithelial cells (MTEC) monolayers as early as 4 h. The Cl- current through cystic fibrosis transmembrane conductance regulator (CFTR) and the activity of Na,K-ATPase were both inhibited by more than 66% at 24 h. The inhibitory effects of LMW-HA on ion channels were reversed by 1 µM NPS-2143, or 150 µg/ml high molecular weight hyaluronan (HMW-HA). In HEK-293 cells expressing the calcium-sensitive Cl- channel TMEM16-A, CaSR was required for the activation of the Cl- current by LMW-HA. This is the first demonstration of lung ions and water transport inhibition by LMW-HA, and its mediation through the activation of CaSR.

Tricuspid surgery at the time of LVAD implant: A critique.

Tricuspid regurgitation (TR) is a common finding in patients with end stage heart failure referred for implantation of left ventricular assist devices. While functional TR frequently resolves after left ventricular unloading, patients with residual and progressive TR demonstrate increased rates of RV dysfunction and poor survival. Criteria for intervention on the tricuspid valve have focused on the degree of tricuspid annular dilatation and the severity of tricuspid regurgitant volume. The surgical decision making regarding intervention on the tricuspid valve remains obscure and historical cohort data cannot distinguish cause from effect.

Pulmonary Vascular Disease Due to Plasma Cell Dyscrasia.

Pulmonary hypertension (PH) has been described in myeloproliferative disorders; monoclonal plasma cell disorder such as polyneuropathy, organomegaly, endocrinopathy, monoclonal gammopathy, and skin changes syndrome; and plasma cell dyscrasias such as multiple myeloma and amyloidosis. We describe 4 cases of PH likely due to pulmonary vascular involvement and myocardial deposition from light chain deposition disease, amyloidosis, and multiple myeloma. On the basis of our clinical experience and literature review, we propose screening for plasma cell dyscrasia in patients with heart failure with preserved ejection fraction, unexplained PH, and hematological abnormalities. We also recommend inclusion of cardiopulmonary screening in patients with monoclonal gammopathy of undetermined significance.

Extracorporeal membrane oxygenation in the management of granulomatosis with polyangiitis.

Granulomatosis with polyangiitis (GPA, also known as Wegener's granulomatosis) is a type of systematic vasculitis that primarily involves the lung and kidney. Diffuse alveolar hemorrhage (DAH) and associated acute respiratory failure are uncommon but devastating complications of GPA. Experience in using extracorporeal membrane oxygenation (ECMO) to manage DAH caused by GPA is limited. We report two GPA patients with DAH that were successfully managed using ECMO support. Examining 13 cases identified in the literature and two of our own, we observed that most patients experienced rapid deterioration in respiratory function in conjunction with a precedent respiratory infection. All 15 patients received veno-venous ECMO support. The median duration of ECMO support was 11 days (interquartile range: 7.5-20.75 days). Bleeding was the most common complication, seen in four (26.7%) cases. All patients were successfully weaned off ECMO after a median length of hospital stay of 42 days (interquartile range: 30-78 days). We demonstrated that the use of ECMO is a reasonable and effective support option in the management of GPA patients with DAH. The risk of bleeding is high but maybe reduced using a lower anticoagulation goal.

Femoral venoarterial extracorporeal membrane oxygenation using a novel biatrial cannula for venous drainage and left ventricular venting.

Extracorporeal life support (ECLS) is an expanding technology for patients in cardiogenic shock. The majority of patients requiring ECLS can be managed with percutaneous venoarterial (VA) femoral cannulation. Despite sufficient extracorporeal circulatory support, a unclear number of patients develop left ventricular distension which can result in increased wall tension and stress as well as worsening pulmonary edema. Indications to vent the left ventricle can be controversial. When venting is indicated, a number of additional procedures may be considered including inotropic support, intra-aortic balloon pump, impella, balloon atrial septostomy, or placement of a transseptal cannula. We present a unique case of a femoral VA extracorporeal membrane oxygenation as a bridge to transplant with left-sided venting using a Bio-Medicus NextGen cannula (Medtronic) with a transseptal approach.

Pedicle flap coverage for infected ventricular assist device augmented with dissolving antibiotic beads: Creation of an antibacterial pocket.

Infectious complications following left ventricular assist device implantation can carry significant morbidity and mortality. The main tenet of treatment is source control which entails local wound care, intravenous antimicrobial therapy, surgical debridement, and at times, soft tissue flap coverage. The mode of therapy depends on the severity, etiology, and location of infection as well as the clinical status of the patient. We describe a case of a 46-year-old male who underwent left ventricular assist device placement complicated by pump thrombosis, recurrent infection, and hardware exposure who was successfully treated with a novel method of staged, soft tissue reconstruction.

Peripheral femoral venoarterial extracorporeal membrane oxygenation as bridge to heart-lung transplant omne iter incipit primus.

Heart-lung transplant (HLT) is a widely accepted modality for certain patients with advanced and refractory cardiopulmonary disease. Some of these patients are critically ill on the transplant waiting list, and venoarterial extracorporeal membrane oxygenation (VA-ECMO) can be used as a bridge to transplantation. Although the experience with ECMO as a bridge to lung transplant is promising, there is limited evidence to use ECMO as a bridge to HLT. Femoral cannulation remains a concern for ambulation given the risk of bleeding and cannula complications despite studies reporting its safety. We present a case of a 56-year-old male with interstitial lung disease and severe secondary pulmonary hypertension, who was successfully bridged to HLT with ambulatory femoral VA-ECMO.

Delayed sternal closure does not reduce complications associated with coagulopathy and right ventricular failure after left ventricular assist device implantation.

Delayed sternal closure (DSC) is occasionally adopted after implantation of left ventricular assist device (LVAD). Recent studies suggest that DSC be used for high risk group of patients with coagulopathy, hemodynamic instability or right ventricular failure. However, whether DSC is efficacious for bleeding complication or right ventricular failure is not known. This study is single center analysis of 52 patients, who underwent LVAD implantation. Of those 52 patients, 40 consecutive patients underwent DSC routinely. The sternum was left open with vacuum assist device after implantation of LVAD. Perioperative outcome of the patients who underwent routine DSC were compared with 12 patients who had immediate sternal closure (IC). Mean Interagency Registry for Mechanically Assisted Circulatory Support (INTERMACS) level of IC group and DSC group were 2.7 and 2.6, respectively. Postoperative bleeding (643 vs. 1469 ml, p < 0.001), duration of inotropic support (109 vs. 172 h, p = 0.034), and time to extubation (26 vs. 52 h, p = 0.005) were significantly increased in DSC group. Length of ICU stay (14 vs. 15 days, p = 0.234) and hospital stay (28 vs. 20 days, p = 0.145) were similar. Incidence of right ventricular failure and tamponade were similar in the two groups. Routine DSC after implantation of an LVAD did not prove to be beneficial in reducing complications associated with coagulopathy and hemodynamic instability including cardiac tamponade or right ventricular failure. We suggest that DSC be selectively applied for patients undergoing LVAD implant.

Flexible Bronchoscopy Is Safe and Effective in Adult Subjects Supported With Extracorporeal Membrane Oxygenation.

BACKGROUND: Previous studies have demonstrated the safety of flexible bronchoscopy (FB) in mechanically ventilated subjects. However, the safety of FB in adult subjects receiving extracorporeal membrane oxygenation (ECMO) has not been described previously. METHODS: A retrospective review was conducted of all adult subjects who underwent FB while receiving ECMO support at the University of Alabama at Birmingham Hospital from January 1, 2013, to December 31, 2014. Physiologic variables, pre- and post-FB ECMO, and ventilator settings were recorded. RESULTS: 79 adult subjects underwent FB receiving ECMO with a total of 223 bronchoscopies. The most common indications for bronchoscopy included diagnostic evaluation of infection in subjects with pneumonia (29%) and clearance of excessive secretions (22%). In 70% of subjects, moderate or greater amounts of secretions were noted. FB yielded positive culture data in 37 subjects (47%), which resulted in a change to the antibiotic regimen in 14 subjects (38%) with positive culture data. No significant differences in mean PaO2 /FIO2 , mean ECMO flow, mean sweep gas, ventilator settings, or hemodynamic parameters (heart rate, oxygen saturation, and mean blood pressure) were noted before and after FB. Complications were mild and transient: blood-tinged secretions after FB in 21% cases, which resolved spontaneously, intraprocedural hypoxemia in 2.2% of cases, and dysrhythmia in <1% of cases. There were no episodes of ECMO cannula dislodgement or inadvertent extubation. CONCLUSIONS: FB can be used safely in adult subjects supported with ECMO and is not associated with significant hemodynamics changes, bleeding, or mechanical complications during ECMO support.

The feasibility of lung transplantation in HIV-seropositive patients.

RATIONALE: HIV seropositivity has long been considered a contraindication to lung transplantation, primarily because of the potential risks of added immunosuppression. In the past decade, however, experience with kidney and liver transplantation in the setting of HIV infection, with achievement of satisfactory outcomes, has grown considerably. This promising development has created a need to reconsider this contraindication to lung transplantation. OBJECTIVES: There is presently limited evidence upon which to base medical decision-making regarding lung transplantation in individuals with HIV infection. In our present study, we wished to extend the existing literature by reporting the outcomes of three individuals with HIV infection who underwent lung transplantation at two centers. METHODS: We compiled data for a case series of three HIV-infected subjects undergoing lung transplantation at two centers. MEASUREMENTS AND MAIN RESULTS: We reviewed medical records to investigate the effects of lung transplantation on the course of HIV infection, the development of HIV-related opportunistic infections or malignancies, the occurrence of lung transplant and HIV drug interactions, and the extent of acute rejection. Subject 1, who underwent transplantation for HIV-associated pulmonary arterial hypertension, experienced recalcitrant acute rejection requiring a lymphocyte-depleting agent with subsequent rapid development of bronchiolitis obliterans syndrome. Subjects 2 and 3, who underwent transplantation for idiopathic pulmonary fibrosis, experienced mild acute rejection but remain free from chronic rejection at 4 and 2 years after transplant, respectively. CONCLUSIONS: Lung transplantation may be feasible for carefully selected patients in the setting of controlled HIV infection. On the basis of our experience with three patients, we caution that acute graft rejection may be more common in such patients.

Insertion of Impella 5.0 to improve candidacy for HeartMate II left ventricular assist device placement.

The Impella 5.0 is a minimally invasive heart assist device that can be used to stabilize patients with cardiogenic shock. We present the case of a 49-year-old female in cardiogenic shock who required left ventricular assist device placement, but was not an optimal candidate for surgery due to severe deconditioning and malnutrition. An Impella 5.0 pump was surgically implanted via right axillary artery approach, which allowed the patient time to improve nutritional and functional status before subsequent placement of HeartMate II left ventricular assist device.

Successful ventricular assist device placement in transposition of the great arteries with pulmonary hypertension.

The use of ventricular assist devices in patients with complex congenital heart disease has not been well described. We present a case of successful ventricular assist device support in a 38-year-old man with congenitally corrected transposition of the great arteries and severe secondary pulmonary hypertension.

Extracorporeal membrane oxygenation as a bridge to pulmonary transplantation.

OBJECTIVE: Acute clinical deterioration preceding death is a common observation in patients with advanced interstitial lung disease and secondary pulmonary hypertension. Patients with pulmonary arterial hypertension refractory to medical therapy are also at risk of sudden cardiac death (cor pulmonale). The treatment of these patients remains complex, and the findings from retrospective studies have suggested that intubation and mechanical ventilation are inappropriate given the universally poor outcomes. Extracorporeal support technologies have received limited attention because of the presumed inability to either recover cardiopulmonary function in the patient with end-stage disease or the presumed inability to proceed to definitive therapy with transplantation. METHODS: A retrospective review was performed of 31 patients from 2 institutions placed on extracorporeal membrane oxygenation as a bridge to lung transplantation compared with similar patients without extracorporeal membrane oxygenation at the same institutions and comparison groups queried from the United Network for Organ Sharing database. RESULTS: We have transplanted 31 patients with refractory lung disease from mechanical artificial lung support. Of the 31 patients, 19 were ambulatory at transplantation. Pulmonary fibrosis (42%), cystic fibrosis (20%), and pulmonary hypertension (16%) were the most common diagnostic codes and acute cor pulmonale (48%) and hypoxia (39%) were the most common indications for device deployment. The average duration of extracorporeal membrane oxygenation support was 13.7 days (range, 2-53 days), and the mean survival of all patients bridged to pulmonary transplantation was 26 months (range, 54 days to 95 months). The 1-, 3-, and 5-year survival was 93%, 80%, and 66%, respectively. The duration of in-house postoperative transplant care ranged from 12 to 86 days (mean, 31 days). Patients requiring an extracorporeal membrane oxygenation bridge had comparable survival to that of the high acuity patients transplanted without extracorporeal membrane oxygenation support in the Scientific Registry of Transplant Recipients database but were at a survival disadvantage compared with the high-acuity patients (lung allocation score, >50) transplanted at the same center who did not require mechanical support (P < .001). CONCLUSIONS: These observations challenge current assumptions about the treatment of selected patients with end-stage lung disease and suggest that "salvage transplant" is both technically feasible and logistically viable. Widespread adoption of artificial lung technology in lung transplant will require the design of clinical trials that establish the most effective circumstances in which to use these technologies. A discussion of a clinical trial and reconsideration of current allocation policy is warranted.

Lung transplant curriculum in pulmonary/critical care fellowship training.

BACKGROUND: Lung transplantation is an evolving specialty with the number of transplants growing annually. PURPOSE: A structured lung transplant curriculum was developed for Pulmonary/Critical Care (Pulm/CC) fellows. METHODS: Scores on pulmonary in-training examinations (ITE) 2 years prior to and 3 years after implementation were reviewed as well as completion of satisfaction surveys. RESULTS: The mean pulmonary ITE score of 1st-year fellows increased from 54.2 ± 2.5 to 63.6 ± 1.2 (M ± SD), p = .002, whereas mean pulmonary ITE score for 2nd-year fellows increased from 63.0 ± 3.0 to 70.7 ± 1.2, p = .019. The combined mean pulmonary ITE score increased from 58.6 ± 2.3 to 67.1 ± 1.2, p = .001. Satisfaction surveys revealed that fellow perception of the curriculum was that the experience contributed to an overall improvement in their knowledge base and clinical skills while opportunity to perform transbronchial biopsies was available. CONCLUSIONS: A structured educational lung transplant curriculum was associated with improved performance on the pulmonary ITE and was perceived by fellows to be beneficial in their education and training while providing opportunities for fellows to perform transbronchial biopsies.