Comments on "The surgical approach of late-onset tracheoesophageal fistula in a tracheostomized COVID-19 patient".

Dear Editor, we have read with interest the case reported by Rotolo et al.  (published in February 2023 as Early Access) concerning the surgical management of tracheoesophageal fistula (TEF) in a COVID-19 patient treated with prolonged mechanical ventilation for severe respiratory failure.

Treprostinil Reconstitutes Mitochondrial Organisation and Structure in Idiopathic Pulmonary Fibrosis Cells.

Idiopathic pulmonary fibrosis (IPF) presents as an incurable change in the lung tissue and mitochondrial dysfunction of unknown origin. Treprostinil, a prostacyclin analogue, has been suggested for IPF therapy. This study assessed the effect of treprostinil on the cAMP signalling and mitochondrial activity in healthy lung fibroblasts and fibroblast-like cells from IPF patients. Six control fibroblast strains and six fibroblast-like IPF cell strains were isolated and expanded from freshly resected lung tissue. The cells were grown to confluence before being treated with either transforming growth factor (TGF)-ß1, treprostinil, their combination, or a vehicle for up to 2 days. Mitochondria-regulating proteins were analysed using Western blotting and immunofluorescence, and the mitochondria were analysed using cytochrome C, mitochondrial cytochrome C oxidase II (MTCO2), and MTCO4. The IPF cells showed an increased rate of damaged mitochondria, which were significantly reduced when the cells were treated with treprostinil over 24 h. In the control cells, treprostinil prevented TGF-ß-induced mitochondrial damage. Treatment with treprostinil modified the expression of several mitochondria-regulating proteins. In both cell types, treprostinil upregulated the expression of PTEN, p21(Waf1/Cip1), beclin1, LC3 II, parkin, PINK1, MTCO2, and MTCO4. In contrast, treprostinil downregulated the phosphorylation of mTOR and the expression of p62, mitofusin1, and mtiofusin2 in IPF cells. This might explain the reduced mitochondrial damage observed in treprostinil-treated IPF cells and suggest an improvement in the mitochondrial function in IPF. In this study, treprostinil improved mitochondrial impairment in vitro, which might, in part, explain the beneficial clinical effects documented in patients.

Persistent alveolar air leak following pulmonary lobectomy: an old problem in a modern era.

Persistent alveolar air leak (PAAL) after major lung resection remains a common complication in thoracic surgery. The aim of this study was to identify a subset of patients with high risk of developing PAAL after pulmonary lobectomy. Another objective was to evaluate the influence of PAAL on postoperative complications and length of hospital stay. A retrospective analysis on 895 patients undergoing pulmonary lobectomy from January 2014 to December 2019 was performed. PAAL was defined as air leak lasting more than 5 days after lung surgery. Univariate analyses and logistic regressions were performed to identify the predictors of PAAL. A backward selection algorithm was used to identify the optimal set of predictors. The incidence of PAAL was 8.2% (74/895). Male gender (p=0.017), BMI (p<0.001), transient ischemic attack (p=0.031), FEV1 (p=0.018), lobectomy combined with adjacent subsegmentectomy (p=0.018), partial and extended pleural adhesions (p=0.033 and p=0.038, respectively) were identified as independent risk factors for PAAL through logistic regression. A weak positive correlation was found between video-assisted thoracic surgery (VATS) and PAAL following pulmonary lobectomy (p=0.100). PAAL was found to be associated with higher risk of postoperative morbidity (p=0.002) and with longer hospital stay (p<0.001). Both preoperative and intraoperative risk factors may be responsible for PAAL after pulmonary lobectomy. VATS does not appear to prevent this postoperative complication. An alveolar air leak lasting beyond 5 days after pulmonary lobectomy is associated with worse postoperative outcomes.

Post-Intubation Tracheoesophageal Fistula: Surgical Management by Complete Cervical Tracheal Transection.

We report successful surgical management of post-intubation tracheoesophageal fistula (TEF) in an adult patient requiring long-term mechanical ventilation. A complete tracheal transection without tracheal resection, via an anterior cervical approach, followed by direct closure of tracheal and esophageal defect, and interposition of muscle flap between the suture lines and tracheal reconstruction was performed. In selected cases, this surgical procedure may be a viable alternative to traditional techniques used to treat post-intubation TEF via the anterior or lateral cervical approach.

Anomalous segmental pulmonary vein: additional V6 behind the bronchus intermedius draining into the superior pulmonary vein.

Anatomical variations of pulmonary venous drainage have been widely described in the literature in order to perform safe thoracic surgical procedures. We report a case of anomalous vein from the superior segment of the right lower lobe running in the posterior mediastinum and draining into the superior pulmonary vein. As the patient showed a usual right inferior pulmonary vein, formed by the union of the superior segment right lower lobe vein (V6) and the common basal vein joining the left atrium, the uncommon segmental pulmonary vein described was named: additional V6. It was identified preoperatively and recognized intraoperatively during thoracoscopic right lower lobectomy and lymph node dissection performed for lung cancer treatment. Diagnostic imaging and careful surgical dissection are helpful tools to avoid intraoperative bleeding and other complications during thoracic surgical procedures due to unrecognized vascular anomalies.

How to avoid "en masse" lobectomy using VATS technique in presence of hilar fibrosis.

Perivascular fibrosis is technically one of the most challenging issue to manage during thoracoscopic lobectomy and it is associated with increased risk of hemorrhagic injury. Here we report a case of thoracoscopic right lower lobectomy performed with individual dissection of segmental arteries due to dense adventitial fibrosis around the right lower lobe pulmonary artery. This approach may be considered as an alternative to the so-called "en masse" lobectomy and a way to avoid conversion to thoracotomy.

Variations in the branching patterns of pulmonary artery during thoracoscopic pulmonary resection.

PURPOSE: The knowledge of variations in the branching patterns of pulmonary artery may have important clinical implications in the field of thoracic surgery. METHODS: At the Department of Thoracic Surgery of Monaldi Hospital in Naples, between January 2017 and December 2019, 569 anatomic pulmonary resections via video-assisted thoracic surgery, including lobectomy and segmentectomy, were performed. RESULTS: Among the 569 thoracoscopic pulmonary resections, 24 variations in the branching patterns of pulmonary artery were identified and documented. Anatomic variations on the left were more frequent than on the right. CONCLUSION: This paper, providing a summary of vascular anomalies identified during major lung resections, could help surgeons avoid intraoperative complications, especially during minimally invasive procedures where the visual field is more restricted than open surgery.

Uncommon anomalies of the left pulmonary artery during VATS lobectomy for lung cancer.

The key to avoid intraoperative complications due to failure in the preoperative detection of pulmonary vascular anomalies is to perform a careful hilar dissection.

Drainage of middle lobe vein into anomalous right lower lobe vein: management during thoracoscopic lobectomy.

Variations in pulmonary venous anatomy should not be underestimated by thoracic surgeons prior to or during major lung resections in order to avoid serious surgical complications. Here, we report a case of middle lobe vein draining into a right inferior lobar vein formed by two anomalous trunks lying on the superior surface of the common basal bronchus: in such instance, to avoid compromising the middle lobe vein drainage during a thoracoscopic right lower lobectomy, the two main tributaries of the lower lobe vein were individually identified and dissected peripherally from the anterior aspect after division of the major fissure. A careful hilar dissection and a precise surgical strategy can help surgeons perform correct procedures in presence of pulmonary vascular anomalies.

Multiple variations in pulmonary veins during a thoracoscopic right lower lobectomy: A case report.

A knowledge of pulmonary vein anatomy variants allows an appropriate preoperative radiological assessment and safe surgical management of vascular anomalies in patients undergoing major lung resections. In our case, multiple pulmonary vein variations were identified pre- and intraoperatively in a patient undergoing thoracoscopic right lower lobectomy and included superior and common basal veins from the right lower lobe draining separately into the left atrium, middle lobe veins joining the superior segment right lower lobe vein and additional superior segment right lower lobe vein draining directly into the left atrium. The recognition of these anatomical abnormalities in pulmonary veins may help thoracic surgeons avoid surgical complications in patients undergoing anatomical lung resections.

AIM2/IL-1α/TGF-ß Axis in PBMCs From Exacerbated Chronic Obstructive Pulmonary Disease (COPD) Patients Is Not Related to COX-2-Dependent Inflammatory Pathway.

Chronic obstructive pulmonary disease (COPD) is a lung disorder characterized by persistent respiratory symptoms and progressive airflow limitation as a consequence of a chronic inflammatory response. Corticosteroids are the main treatment for COPD patients with a history of exacerbation, in that they attenuate exacerbation and dyspnea, and improve the response to bronchodilators. Nevertheless, despite corticosteroid administration, COPD patients still undergo exacerbation phases. In this context, the aim of this study was to evaluate the activity of Absent in melanoma 2 (AIM2) inflammasome-dependent pathways under corticosteroid treatment during COPD exacerbation. Stable and exacerbated COPD-derived Peripheral Blood Mononuclear Cells (PBMCs) were treated with a well-known anti-inflammatory agent, Dexamethasone (DEX), in the presence or not of Poly (deoxyadenylic-deoxythymidylate) acid (Poly dA:dT), an AIM2 ligand. We found that IL-1α was highly increased when AIM2 was activated from Poly dA:dT in exacerbated, but not in stable, COPD-derived PBMCs. To note, the release of IL-1α after the stimulation of AIM2 in PBMCs obtained from stable (hospitalized) COPD patients was not higher from the basal conditions, though it was still as high as that observed for Poly dA:dT-stimulated PBMCs obtained from exacerbated patients. This effect was associated with a higher expression of AIM2 in pair-matched circulating CD14+ cells obtained from hospitalized patients who passed from the exacerbation to stable status. Because the difference between stable and exacerbated COPD patients relies on the treatment with corticosteroids, exacerbated and stable COPD-derived PBMCs were treated with DEX. Indeed, the release of IL-1α and TGF-ß was not altered after DEX treatment. In conclusion, we found that the administration of DEX in vitro on exacerbated COPD-derived PBMCs was not able to revert the detrimental inflammatory mechanism associated with AIM2 activation responsible for the release of IL-1α and the ensuing TGF-ß, contributing to the severity of disease.

Left lower lobectomy and partial preservation of segmental arteries of left upper lobe: A strategy to avoid pneumonectomy in selected cases.

In this article we report two cases of left lower lobe lung cancer undergoing a surgical procedure that allowed the preservation of lung parenchyma and avoided pneumonectomy. The first case concerned a left lower lobe non-small cell lung cancer with extracapsular spread in a metastatic interlobar lymph node and the second a left lower lobe lung cancer with invasion of the pulmonary artery at the origin of lobar branches to the lower lobe. In both cases, a lung-sparing surgical treatment was preferred and a left lower lobectomy was performed with division of lingular arteries and the interlobar artery, preserving the remaining arterial branches to the upper lobe.