Makey, Ian

ABSTRACT Background Treating Mycobacterium avium complex (MAC) infection pre‐lung transplant (LT) can be challenging to treat, given prolonged therapy and side effects. The impact of pre‐transplant MAC treatment on recurrence and outcomes post‐LT remains unclear, especially in patients with interstitial lung disease (ILD) who have a median survival of less than 2 years. Methods We performed a retrospective cohort study of adult LT patients at the Mayo Clinic who had positive MAC sputum cultures pre‐LT. The cohort was stratified and compared based on the type of treatment (complete, partial, or no treatment) for MAC pulmonary infection. The primary outcome was MAC recurrence post‐LT, and secondary outcomes were mortality, FEV‐1, and FVC at 1‐year post‐LT. Results Among the cohort of 47 patients, 9 (19.1%) were partially treated and 11 (23.4%) were completely treated for MAC infection pre‐LT. Post‐transplant MAC pulmonary infection recurrence occurred in eight (17%) of the total cohort, with four (14.8%) in the non‐treated, four (44.4%) in the partially‐treated, and none (0%) in the completely treated patients ( p = 0.026). There was no difference in mortality in patients who had MAC recurrence post‐transplantation (13% vs. 9.7%, p > 0.9) and those who were completely or partially treated, compared to non‐treated (0% vs. 13% vs. 13%, p > 0.9). The FEV1 and FVC at 1‐year post‐LT did not differ by the pre‐transplant treatment or post‐transplant MAC recurrence status. Conclusion The role of treatment for MAC infection pre‐transplant is questionable, especially in patients with diseases like ILD who may not have enough wait time to complete therapy.

Objective: We tested the feasibility and effectiveness of a percutaneous atrial transseptal extracorporeal membrane oxygenation (ECMO) cannulation strategy in a right ventricular failure (RVF) model. Methods: We performed 4 nonsurvival porcine experiments. Percutaneous transseptal access was achieved using a steerable introducer. For guidance, we used fluoroscopy, transesophageal echocardiogram (TEE), and intracardiac echocardiography (ICE). A ProtekDuo rapid deployment cannula (LivaNova, London, UK) was advanced across the septum into the left atrium by 2 to 3 cm. Pulmonary hypertension (PH) was induced by partially clamping the pulmonary artery. ECMO flow was cycled from high (2 to 3 L/min) to low (0.2 to 0.3 L/min) over 2 to 3 hours. Results: Transseptal access using TEE and fluoroscopy was successful in 1 animal and unsuccessful in 1 animal. ICE provided optimal visualization for the remaining 2 animals. Mean arterial pressure (MAP) was associated immediately and consistently with high versus low ECMO flow rate (mean difference: 29 ± 3.1 mm Hg, P = 0.004) but was not restored to baseline values. RV pressure values were dynamic. Given time to equilibrate, mean RV pressure was restored to a baseline level. Conclusions: Percutaneous right atrium to left atrium transseptal cannulation relieved PH-RVF. MAP was restored to a viable level, and mean RV pressure was restored to a baseline level. Transseptal ECMO shows promise as a cannulation strategy to bridge patients with PH-RVF to lung transplant.

Pulmonary Langerhans cell histiocytosis (PLCH) is a rare inflammatory condition that mostly affects lungs in smokers. On imaging, it usually presents as multiple, upper lobe predominant, solid, and cavitary nodules, but presentation as solitary pulmonary nodule (SPN) is rare. We describe a case of SPN seen on low-dose lung cancer screening CT (LDCT) that was FDG avid on PET/CT. Given concern for malignancy, lobectomy was planned if intraoperative frozen section was consistent with malignancy. Lobectomy was performed based on frozen section; however, on formal pathology review, the nodule was ultimately found to be PLCH. This case illustrates an atypical presentation of PLCH as a solitary nodule. Furthermore, it helps demonstrate how rare etiologies (like PLCH) may be more frequently encountered and should be considered in the differential diagnosis for solitary lung nodules, especially in the era of lung cancer screening.

Background. Retained hemothorax (RH) is a common problem in cardiothoracic and trauma surgery. We aimed to determine the optimum agitation technique to enhance thrombus dissolution and drainage and to apply the technique to a porcine-retained hemothorax. Methods. Three agitation techniques were tested: flush irrigation, ultrasound, and vibration. We used the techniques in a benchtop model with tissue plasminogen activator (tPA) and pig hemothorax with tPA. We used the most promising technique vibration in a pig hemothorax without tPA. Statistics. We used 2-sample t tests for each comparison and Cohen d tests to calculate effect size (ES). Results. In the benchtop model, mean drainages in the agitation group and control group and the ES were flush irrigation, 42%, 28%, and 2.91 ( P = .10); ultrasound, 35%, 27%, and .76 ( P = .30); and vibration, 28%, 19%, and 1.14 ( P = .04). In the pig hemothorax with tPA, mean drainages and the ES of each agitation technique compared with control (58%) were flush irrigation, 80% and 1.14 ( P = .37); ultrasound, 80% and 2.11 ( P = .17); and vibration, 95% and 3.98 ( P = .06). In the pig hemothorax model without tPA, mean drainages of the vibration technique and control group were 50% and 43% (ES = .29; P = .65). Discussion. In vitro studies suggested flush irrigation had the greatest effect, whereas only vibration was significantly different vs the respective controls. In vivo with tPA, vibration showed promising but not statistically significant results. Results of in vivo experiments without tPA were negative. Conclusion. Agitation techniques, in combination with tPA, may enhance drainage of hemothorax.

Objective To test whether use of the radial stapler facilitates lung-conserving wedge resections compared to the linear stapler. Methods A video-assisted thoracoscopic simulation lab was established to compare wedge resections performed only with linear staplers to wedge resections performed with the option of a radial stapler. Preserved sheep lungs were used. The target was a 0.5 cm mark on an ovoid surface of the lung equidistant from all edges. Seven fully trained cardiothoracic surgeons participated. They were instructed to obtain at least a 1 cm margin in all directions from the mark. The surgeons were allowed to work from only 2 preassigned ports. Each resected specimen was weighed. The resection margin was the shortest distance measured from the edge of the mark to the staple line. The mass-to-margin ratio was defined as the mass of the specimen divided by the length of the margin. The results were analyzed using a t-test for 2 independent means. Results The 17 radial resections demonstrated a significantly better mass-to-margin ratio (3.31 [SD = 1.19]) compared to the 11 linear resections (4.75 [SD = 1.32], t[26] = 3, P = 0.006). Conclusions In a thoracoscopic simulation, the option of a radial stapler allowed for a better mass-to-margin resection of a small target from a broad surface of the lung than a linear stapler-only option.