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Background: Reverse Potts shunt (RPS) and lung or heart-lung transplantation are life-extending surgical interventions for pediatric patients with severe pulmonary arterial hypertension (PAH). Robust criteria for identifying patients who will benefit from these procedures remain elusive. Based on 30 years of experience, we sought to refine the surgical indications., Methods: This single-center retrospective cohort study included 61 consecutive pediatric patients with PAH managed by RPS (2004-2020) or transplantation (1988-2020). Their mid-term outcomes were assessed., Results: Compared with the 20 patients managed by RPS, the 41 transplant waitlist patients, of whom 28 were transplanted, were older (14.9 vs 8.0 years, P = .0001), had worse right ventricular impairment (tricuspid annular plane systolic excursion, 12.5 mm vs 18.0 mm, P = .03), and were managed later in the evolution of the disease (6.0 vs 1.7 years, P = .002). After implementation of a high-priority allocation program in 2007, waitlist mortality decreased from 52.6% to 13.6% (P = .02) and 5-year survival increased from 57.1% to 74.7% after RPS and 55.6% to 77.2% after transplantation. At a median follow-up of 8.6 years after RPS and 5.9 years after transplantation, functional capacity had improved significantly, and PAH-specific drug requirements had diminished markedly in the RPS group. Two patients successfully underwent double-lung transplant 6 and 9 years after RPS., Conclusions: In selected children with suprasystemic PAH, RPS is associated with functional capacity improvements and decreased pharmacotherapy needs over the midterm. RPS deserves consideration earlier in the course of pediatric PAH, with transplantation being performed in the event of refractory RV failure., Competing Interests: Conflict of Interest Statement The authors reported no conflicts of interest. The Journal policy requires editors and reviewers to disclose conflicts of interest and to decline handling or reviewing manuscripts for which they may have a conflict of interest. The editors and reviewers of this article have no conflicts of interest., (Copyright © 2023 The American Association for Thoracic Surgery. Published by Elsevier Inc. All rights reserved.)

Objective: Tracheobronchial adenoid cystic carcinoma is a rare, slow-growing malignancy with a considerable propensity for local extension that may require complex airway resection to achieve tumor-free margins. The objective of this study was to assess whether our experience supports complex airway resection for tracheobronchial adenoid cystic carcinoma., Methods: Consecutive patients who underwent curative resection for tracheobronchial adenoid cystic carcinoma at our institution between 1970 and 2019 were included retrospectively and classified as having had complex or standard resection. Complex surgery included total tracheal replacement, associated esophageal resection, pneumonectomy, total laryngectomy with tracheal resection, and carinal resection. Standard surgery included tracheal resection, bronchoplastic resection, lobectomy, and bilobectomy. We obtained data from medical records, referring physicians, patients, relatives, and public death records., Results: Of 59 included patients, 38 had complex and 21 had standard surgery. All 4 (6.8%) patients who died postoperatively had undergone complex surgery. Postoperative morbidity was 32.2% overall and was significantly higher after complex surgery (P = .043). Overall 5- and 10-year survival rates were 81.5% and 60.2%, with no significant differences between groups (P = .31). By univariate analysis, T4 tumor and microscopically detectable tumor in the operative specimen margins and gross tumor in the operative specimen margins were associated with poorer survival (P < .05). In the subgroup with microscopically detectable tumor resection, survival was significantly better with adjuvant radiotherapy (P < .05)., Conclusions: Complex resection for extended tracheobronchial adenoid cystic carcinoma may achieve local control and satisfying long-term survival. However, this demanding procedure is associated with high postoperative morbidity and mortality rates. Because adjuvant radiotherapy improved outcomes after resection resulting in microscopically detectable tumor in the operative specimen margins, expected outcomes after resection with no detectable tumor in the margins must be compared to those after resection resulting in microscopically detectable tumor in the margins plus radiotherapy, according to the operative risk., (Copyright © 2022 The American Association for Thoracic Surgery. Published by Elsevier Inc. All rights reserved.)

Objective: The use of mechanical circulatory support (MCS) in lung transplantation has been steadily increasing over the prior decade, with evolving strategies for incorporating support in the preoperative, intraoperative, and postoperative settings. There is significant practice variability in the use of these techniques, however, and relatively limited data to help establish institutional protocols. The objective of the AATS Clinical Practice Standards Committee (CPSC) expert panel was to review the existing literature and establish recommendations about the use of MCS before, during, and after lung transplantation., Methods: The AATS CPSC assembled an expert panel of 16 lung transplantation physicians who developed a consensus document of recommendations. The panel was broken into subgroups focused on preoperative, intraoperative, and postoperative support, and each subgroup performed a focused literature review. These subgroups formulated recommendation statements for each subtopic, which were evaluated by the entire group. The statements were then developed via discussion among the panel and refined until consensus was achieved on each statement., Results: The expert panel achieved consensus on 36 recommendations for how and when to use MCS in lung transplantation. These recommendations included the use of veno-venous extracorporeal membrane oxygenation (ECMO) as a bridging strategy in the preoperative setting, a preference for central veno-arterial ECMO over traditional cardiopulmonary bypass during the transplantation procedure, and the benefit of supporting selected patients with MCS postoperatively., Conclusions: Achieving optimal results in lung transplantation requires the use of a wide range of strategies. MCS provides an important mechanism for helping these critically ill patients through the peritransplantation period. Despite the complex nature of the decision making process in the treatment of these patients, the expert panel was able to achieve consensus on 36 recommendations. These recommendations should provide guidance for professionals involved in the care of end-stage lung disease patients considered for transplantation., (Copyright © 2022 The American Association for Thoracic Surgery. Published by Elsevier Inc. All rights reserved.)

Objective: To determine whether preoperative systemic inflammation (defined by C-reactive protein [CRP] levels ≥10 mg/L) is associated with worse functional and hemodynamic status and poor early outcomes postendarterectomy in patients with chronic thromboembolic pulmonary hypertension (CTEPH)., Methods: This study included 159 patients who underwent pulmonary endarterectomy from 2009 to 2013 (derivation cohort) and 238 patients from 2015 to 2016 (validation cohort) with CRP data from the national CTEPH registry. The correlations between proinflammatory markers (CRP, interleukins 1 and 6, fibrinogen, and leukocytes) and hemodynamics were assessed in the derivation cohort. Pre-, perioperative characteristics, and 30-day outcomes (ie, death or lung transplant or extracorporeal membrane oxygenation need or inotropic or vasopressor need ≥3 days) of patients with CRP levels ≥ or <10 mg/L were compared., Results: Median age of the derivation cohort was 63 [52-73] years with 48% female, 80% in New York Heart Association class III/IV. The validation cohort had similar demographics and disease severity. Patients with CRP ≥10 mg/L had greater resistance levels and lower cardiac index than those with CRP <10 mg/L in both cohorts. The primary endpoint was reached in 38% (derivation) and 42% (validation) of patients. In multivariable logistic regression analysis, CRP ≥10 mg/L was associated with the primary endpoint in both the derivation cohort (odd ratio, 2.49 [1.11-5.61], independently of New York Heart class class IV and aortic clamping duration) and the validation cohort (odd ratio, 1.89 [1.09-3.61], independently of age and aortic clamping duration)., Conclusions: Preoperative CRP ≥10 mg/L is independently associated with adverse early outcomes postendarterectomy., (Copyright © 2020 The American Association for Thoracic Surgery. Published by Elsevier Inc. All rights reserved.)

Objective: We aimed to assess the mitochondrial respiratory capacities in the right ventricle in the setting of ventricular remodeling induced by pressure overload., Methods: Chronic thromboembolic pulmonary hypertension was induced in 8 piglets over a 12-week period (chronic thromboembolic pulmonary hypertension model). Right ventricular remodeling, right ventricular function, and mitochondrial respiratory function were assessed at 3, 6, and 12 weeks after induction of pulmonary hypertension and were compared with sham animals (n = 5). Right ventricular cardiomyocytes and mitochondrial structure were studied in transmission electronic microscopy after 12 weeks., Results: As of 3 weeks, chronic pressure overload induced right ventricular dilatation, right ventricular hypertrophy, and right ventricular dysfunction. Maladaptive remodeling in the chronic thromboembolic pulmonary hypertension model was confirmed by the decrease of right ventricular pulmonary artery coupling and right fractional area change. Mitochondrial functional assays in permeabilized right ventricular myocardial fibers revealed that oxidative phosphorylation capacities (complex I, complex II, and IV of the mitochondrial respiratory chain) were degraded. Furthermore, no change in substrate preference of mitochondria was found in the overloaded right ventricle. There was a good correlation between maximal mitochondrial oxygen consumption rate and right ventricular pulmonary artery coupling (Pearson coefficient r = 0.83). Transmission electronic microscopy analysis showed that the composition of cardiomyocytes was no different between the chronic thromboembolic pulmonary hypertension group and the sham group. However, mitochondrial structure anomalies were significantly increased in the chronic thromboembolic pulmonary hypertension group., Conclusions: Mitochondrial respiratory function impairment is involved early in the development of right ventricular dysfunction in a piglet model of chronic thromboembolic pulmonary hypertension. Underlying mechanisms remain to be elucidated., (Copyright © 2019 The American Association for Thoracic Surgery. Published by Elsevier Inc. All rights reserved.)

Background: Right ventricular (RV) failure is the main prognostic factor in pulmonary hypertension, and ventricular capillary density (CD) has been reported to be a marker of RV maladaptive remodeling and failure. Our aim was to determine whether right intracoronary endothelial progenitor cell (EPC) infusion can improve RV function and CD in a piglet model of chronic thromboembolic pulmonary hypertension (CTEPH)., Methods: We compared 3 groups: sham (n = 5), CTEPH (n = 6), and CTEPH with EPC infusion (CTEPH+EPC; n = 5). After EPC isolation from CTEPH+EPC piglet peripheral blood samples at 3 weeks, the CTEPH and sham groups underwent right intracoronary infusion of saline, and the CTEPH+EPC group received EPCs at 6 weeks. RV function, pulmonary hemodynamics, and myocardial morphometry were investigated in the animals at 10 weeks., Results: After EPC administration, the RV fractional area change increased from 32.75% (interquartile range [IQR], 29.5%-36.5%) to 39% (IQR, 37.25%-46.50%; P = .030). The CTEPH+EPC piglets had reduced cardiomyocyte surface areas (from 298.3 μm 2 [IQR, 277.4-335.3 μm 2 ] to 234.6 μm 2 (IQR, 211.1-264.7 μm 2 ; P = .017), and increased CD31 expression (from 3.12 [IQR, 1.27-5.09] to 7.14 [IQR, 5.56-8.41; P = .017). EPCs were found in the RV free wall at 4 and 24 hours after injection but not 4 weeks later., Conclusions: Intracoronary infusion of EPC improved RV function and CD in a piglet model of CTEPH. This novel cell-based therapy might represent a promising RV-targeted treatment in patients with pulmonary hypertension., (Copyright © 2018 The American Association for Thoracic Surgery. Published by Elsevier Inc. All rights reserved.)

Objective: Mechanisms of right ventricular (RV) adaptation to chronic pressure overload are not well understood. We hypothesized that a lower capillary density (CD) to stroke work ratio would be associated with more fibrosis and RV maladaptive remodeling., Methods: We induced RV chronic pressure overload over a 20-week period in 2 piglet models of pulmonary hypertension; that is, a shunt model (n = 5) and a chronic thromboembolic pulmonary hypertension model (n = 5). We assessed hemodynamic parameters and RV remodeling as well as RV CD, fibrosis, and angiogenic factors expression., Results: Although RV was similarly hypertrophied in both models, maladapted RV remodeling with impaired systolic function was only seen in chronic thromboembolic pulmonary hypertension group members who had lower CD (484 ± 99 vs 1213 ± 74 cap/mm 2 ; P < .01), lower CD to stroke work ratio (0.29 ± 0.07 vs 0.82 ± 0.16; P = .02), higher myocardial fibrosis (15.4% ± 3.8% vs 8.0% ± 2.5%; P < .01), as well as a higher angiogenic and fibrosis factors expression., Conclusions: The RV adaptive response to chronic pressure overload differs between 2 different piglet models of PH. Mismatch between angiogenesis and workload (CD to stroke work ratio) was associated with greater degree of myocardial fibrosis and RV dysfunction and could be a promising index of RV maladaptation. Further studies are needed to understand the underlying mechanisms., (Copyright © 2017 The American Association for Thoracic Surgery. Published by Elsevier Inc. All rights reserved.)

Objective: The study objective was to compare the outcomes of intraoperative extracorporeal membrane oxygenation versus cardiopulmonary bypass support in lung transplantation., Methods: We performed a retrospective cohort study from a prospective database of adult lung transplantations performed at the University of Toronto from 2007 to 2013. Among 673 lung transplantations performed in the study period, 267 (39.7%) required cardiopulmonary support. There were 39 cases of extracorporeal membrane oxygenation (2012-2013) and 228 cases of cardiopulmonary bypass (2007-2013). Patients who were bridged with extracorporeal life support, underwent a concomitant cardiac procedure, received a combined liver or heart transplant, were colonized with Burkholderia cenocepacia, or required emergency cannulation for cardiopulmonary support were excluded. Finally, 33 extracorporeal membrane oxygenation cases were matched with 66 cases of cardiopulmonary bypass according to age (±10 years), lung transplantation indication, and procedure type (bilateral vs single lung transplantation)., Results: Recipient factors such as body mass index and gender were not different between extracorporeal membrane oxygenation and cardiopulmonary bypass groups. Furthermore, donor variables were similar, including age, body mass index, last PaO2/FiO2 ratio, smoking history, positive airway cultures, and donor type (brain death and donation after cardiac death). Early outcomes, such as mechanical ventilation requirement, length of intensive care unit stay, and length of hospital stay, significantly favored extracorporeal membrane oxygenation (median 3 vs 7.5 days, P = .005; 5 vs 9.5 days, P = .026; 19 vs 27 days, P = .029, respectively). Perioperative blood product transfusion requirement was lower in the extracorporeal membrane oxygenation group. The 90-day mortality for the extracorporeal membrane oxygenation group was 6% versus 15% for cardiopulmonary bypass (P = .32)., Conclusions: Extracorporeal membrane oxygenation may be considered as the first choice of intraoperative cardiorespiratory support for lung transplantation., (Copyright © 2015 The American Association for Thoracic Surgery. Published by Elsevier Inc. All rights reserved.)

Objectives: Continuous flow in Fontan circulation results in impairment of pulmonary artery endothelial function, increased pulmonary vascular resistance, and, potentially, late failure of Fontan circulation. Bidirectional cavopulmonary shunt is the interim procedure in palliation of patients with single-ventricle physiology, but pulmonary arteriovenous malformations occur in many patients. In a porcine chronic model of cavopulmonary shunt, we studied pulmonary hemodynamics, pulmonary arteriovenous malformation occurrence, and gas exchange capabilities. We hypothesized that residual antegrade pulsatile pulmonary flow may attenuate the deleterious effects of nonpulsatile Fontan-type circulation., Methods: Thirty pigs underwent a sham procedure (n = 10, group I), a cavopulmonary shunt with right pulmonary artery ligation (n = 10, group II, nonpulsatile), or a cavopulmonary shunt with proximal right pulmonary artery partial ligation (n = 10, group III, micropulsatile). Three months later, in vivo hemodynamics, blood gas exchange, pulmonary arteriovenous malformation occurrence, and lung histology were assessed., Results: At 3 months, group II right lungs demonstrated significantly increased pulmonary artery pressure, pulmonary vascular resistance, and evidence of pulmonary arteriovenous malformations compared with groups I and III (all P < .001). Group III lungs also showed increased pulmonary artery pressure and pulmonary vascular resistance compared with the sham group, but significantly less than group II. Group III right lungs had the best gas exchange performance, with less histologic changes compared with group II., Conclusions: We developed a viable chronic large animal model of bidirectional cavopulmonary anastomosis. Residual antegrade pulsatile flow in the setting of a cavopulmonary shunt prevents pulmonary arteriovenous malformation formation and attenuates, but does not suppress, the development of pulmonary hypertension. From a clinical standpoint, these data would support keeping a small amount of antegrade pulsatile flow during creation of a cavopulmonary shunt., (Copyright © 2013 The American Association for Thoracic Surgery. Published by Mosby, Inc. All rights reserved.)

Objective: The study objective was to determine whether the vasculopathy seen in nonobstructed lung regions in chronic thromboembolic pulmonary hypertension is induced by the local blood flow increase or by factors released by the ischemic lung., Methods: Three groups of 10 piglets were studied 5 weeks after right pulmonary artery ligation, right pneumonectomy, or right pulmonary artery dissection (sham). Pulmonary vascular resistance, pulmonary arterial vasoreactivity, and morphometry were measured, and gene expressions of factors involved in vascular smooth muscle cell proliferation were quantified., Results: Left lung blood flow was similarly increased after right pneumonectomy and right pulmonary artery ligation. Compared with right pneumonectomy, right pulmonary artery ligation resulted in left lung vasculopathy with increased pulmonary vascular resistance (P = .0009), medial hypertrophy of the distal pulmonary artery (P < .0001), and decreases in maximal relaxation to acetylcholine (P = .013) and endothelial nitric oxide synthase gene expression (P = .041). These values were similar after sham and right pneumonectomy. In the left lung, right pulmonary artery ligation increased the gene expressions for insulin-like growth factor (P = .034), platelet-derived growth factor (P = .0006), and vascular endothelial growth factor (P = .0105) compared with right pneumonectomy and sham. Whereas endothelin-1 gene expression was not affected, expressions of endothelin-1 receptors A and B were downregulated after right pneumonectomy (P = .048 and P = .039, respectively) and right pulmonary artery ligation (P = .033 and P = .028, respectively)., Conclusions: Pulmonary vasculopathy was absent in the remaining lung 5 weeks after right pneumonectomy but developed in the nonobstructed lung regions 5 weeks after right pulmonary artery ligation, suggesting that factors released by the ischemic lung induced vascular remodeling in the contralateral lung. This endocrine process may involve the release of factors involved in vascular smooth muscle cell proliferation., (Copyright © 2012 The American Association for Thoracic Surgery. Published by Mosby, Inc. All rights reserved.)

Objective: Airway replacement after long-segment tracheal resection for benign and malignant disease remains a challenging problem because of the lack of a substitute conduit. Ideally, an airway substitute should be well vascularized, rigid, and autologous to avoid infections, airway stenosis, and the need for immunosuppression. We report the development of an autologous tracheal substitute for long-segment tracheal resection that satisfies these criteria and demonstrates excellent short-term functional results in a large-animal study., Methods: Twelve adult pigs underwent long-segment (6 cm, 60% of total length) tracheal resection. Autologous costal cartilage strips measuring 6 cm x 2 mm were harvested from the chest wall and inserted at regular 0.5-cm intervals between dermal layers of a cervical skin flap. The neotrachea was then scaffolded by rotating the composite cartilage skin flap around a silicone stent measuring 6 cm in length and 1.4 cm in diameter. The neotrachea replaced the long segment of tracheal resection, and the donor flap site was closed with a double-Z plasty. Animals were killed at 1 week (group I, n = 4), 2 weeks (group II, n = 4), and 5 weeks (group III, n = 4). In group III the stent was removed 1 week before death. Viability of the neotrachea was monitored by means of daily flexible bronchoscopy and histologic examination at autopsy. Long-term morbidity and mortality were determined by monitoring weight gain, respiratory distress, and survival., Results: There was no mortality during the study period. Weight gain was appropriate in all animals. Daily bronchoscopy and postmortem histologic evaluation confirmed excellent viability of the neotrachea. There was no evidence of suture-line dehiscence. Five animals had distal granulomas that were removed by using rigid bronchoscopy. In group III 1 animal had tracheomalacia, which was successfully managed by means of insertion of a silicon stent., Conclusion: Airway reconstruction with autologous cervical skin flaps scaffolded with costal cartilages is a novel approach to replace long segments of resected trachea. This preliminary study demonstrates excellent respiratory function and survival in large animals undergoing resection of more than 50% of their native trachea. Use of cervical skin flaps buttressed with costal cartilage is a promising solution for long-segment tracheal replacement.

Objectives: Chronic thromboembolic pulmonary hypertension is due to partial obstruction of the pulmonary arterial bed and may resolve after pulmonary thromboendarterectomy. Persistent pulmonary hypertension, the main complication after pulmonary thromboendarterectomy, may reflect vessel alterations induced by high flow in unobstructed lung territories. The aim of this study was to determine whether correcting high flow led to reversal of the vasculopathy in piglets., Methods: The effects of high pulmonary blood flow were investigated 5 weeks after creation of an aortopulmonary shunt (n = 10), and reversibility of vessel disease was evaluated at 1 week (n = 10) and 5 weeks after shunt closure (n = 10), compared to sham-operated animals (n = 10). Hemodynamic variables, pulmonary artery reactivity, and morphometry were recorded. We also investigated the endothelin, angiopoietin, and nitric oxide synthase pathways., Results: High flow increased medial thickness in distal pulmonary arteries (55.6% +/- 1.2% vs 35.9% +/- 0.8%; P < .0001) owing to an increase of smooth muscle cell proliferation (proliferating cell nuclear antigen labeling). The endothelium-dependent relaxation was altered (P < .05). This phenomenon was associated to an overexpression of endothelin-1, endothelin-A, angiopoietin 1, angiopoietin 2, and Tie-2 (P < .05). After 1 week of shunt closure, all overexpressed genes returned to control values, the proliferation of smooth muscle cells stopped, and smooth muscle cell apoptosis increased (terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling), preceding the normalization of the wall thickness hypertrophy and the pulmonary artery vasoreactivity observed at 5 weeks after shunt closure., Conclusion: These results demonstrate that endothelin-1 and angiopoietin pathways are involved in vasculopathy development and may be important therapeutic targets for preventing persistent pulmonary hypertension after pulmonary thromboendarterectomy.

Objective: Pulmonary inflammatory pseudotumor is an uncommon disease, often with a benign presentation. However, invasion of adjacent thoracic organs, local recurrence, and distant metastases have been described, and the best management strategy remains unclear. We present a single large institutional experience in patients with pulmonary inflammatory pseudotumor and propose guidelines for treatment of this patient population., Methods: A retrospective study was performed to review all patients who underwent resection for pulmonary inflammatory pseudotumor between 1974 and 2007., Results: A total of 25 patients were treated with pulmonary inflammatory pseudotumor at the Marie Lannelongue Hospital. The mean age was 33 years. Two patients were referred after an incomplete resection. One patient presented with cerebral metastasis. We performed a complete resection in all patients: wedge resection (n = 7), lobectomy (n = 6), sleeve arterial lobectomy (n = 1), lobectomy with thoracic inlet exenteration (n = 2), bilobectomy (n = 2), pneumonectomy with brain metastasectomy (n = 1), sleeve pneumonectomy (n = 2), sleeve main bronchus or tracheal resection (n = 2), wedge with sleeve main pulmonary artery resections (n = 1), and sleeve pneumonectomy with esophageal, aortic arch, and right pulmonary artery resection (n = 1). No adjuvant therapy was given to any patients. Postoperative 30-day mortality and morbidity rates were 4% and 8%, respectively. With a mean follow-up of 80 months (range 4-369 months, 100% follow-up), actuarial 10-year survival was 89%. One patient died of an extensive sarcomatous recurrence 2 years after surgery., Conclusion: Pulmonary inflammatory pseudotumor is a malignant disease affecting young patients with local invasion, distant metastasis, local recurrence, and sarcomatous degeneration. A complete resection should always be performed at initial presentation because of its high likelihood of cure with aggressive management.