Stem Cells Application in Thoracic Surgery: Current Perspective and Future Directions

Anastomosis Complications after Bronchoplasty: Incidence, Risk Factors, and Treatment Options Reported by a Referral Cancer Center

BACKGROUND

Sleeve lobectomy with bronchoplasty is a safe surgical technique for the management of lung cancer and endobronchial localization of extrapulmonary cancers. However, anastomotic complications can occur, and treatment strategies are not standardized.

METHODS

Data from 280 patients subjected to bronchoplasty were retrospectively analyzed, focusing on surgical techniques, anastomotic complications, and their management. Multivariate analysis was performed, and Kaplan-Meier curves were used to determine survival.

RESULTS

Ninety percent of 280 surgeries were for lung cancer. Anastomotic complications occurred in 6.42% of patients: late stenosis in 3.92% and broncho-pleural fistula in 1.78%. The median survival was 65.90 months (95% CI = 41.76-90.97), with no difference (p = 0.375) for patients with (51.28 months) or without (71.03 months) anastomotic complications. Mortality at 30 days was higher with anastomotic complications (16.7% vs. 3%, p = 0.014). Multivariable analysis confirmed pathological stage (N+) as a risk factor for anastomotic complications (p = 0.016). Our mortality (3.93%) and morbidity rate (41.78%) corresponded to recent series results.

CONCLUSIONS

In our experience, surgery is preferred to avoid life-threatening complications in bronchopleural fistulas. Bronchoscopic balloon dilatation is preferred for benign strictures. The nodal stage is related to complications (p = 0.0014), reflecting the aggressiveness of surgery, which requires extended radical lymphadenectomy.

Mesenchymal Stromal Cell Therapy for Thoracic Surgeons: An Update

Stem cells are undifferentiated cells presenting extensive self-renewal features and the ability to differentiate "in vitro" and "in vivo" into a range of lineage cells, like chondrogenic, osteogenic and adipogenic lineages when cultured in specific inducing media. Two major domains of clinical applications of stem cells in thoracic surgery have been investigated: regenerative medicine, which is a section of translational research in tissue engineering focusing on the replacement, renewal or regeneration of cells, tissues and organs to re-establish damaged physiologic functions; drug loading and delivery, representing a new branch proposing stem cells as carriers to provide selected districts with anti-cancer agents for targeted treatments.

[Early predictor of bronchial suture failure after pneumonectomy]

OBJECTIVE

To identify the relationship between serum CRP/albumin and bronchial suture failure after pneumonectomy.

MATERIAL AND METHODS

A retrospective analysis included 100 patients who underwent pneumonectomy with extended lymph node dissection for lung cancer. Patients were divided into 2 groups depending on postoperative complications: group 1 - bronchial stump failure, group 2 - no similar complications. In all patients, we analyzed markers of inflammation (C-reactive protein and albumin) in preoperative period and after 24 postoperative hours. Bronchial stump failure was found in 20 patients (10 patients (14.7%) after left-sided pneumonectomy and 10 (31%) patients after right-sided pneumonectomy). We found a significant relationship between serum CRP/albumin and bronchial stump failure after pneumonectomy (p<0.05). A prognostic formula was based on the ratio of serum C-reactive protein and albumin: PC = CRP/Alb, where PC - prognostic coefficient, CRP - serum C-reactive protein (mg/l) 24 hours after surgery, Alb - serum albumin (g/l) 24 hours after surgery. PC >2.6 determines high risk of bronchial stump failure after pneumonectomy, PC <2.6 - low risk. Sensitivity of this method is 90%, specificity - 97.5%.

Regenerative medicine approaches for the management of respiratory tract fistulas

Respiratory tract fistulas (or fistulae) are abnormal communications between the respiratory system and the digestive tract or the adjacent organs. The origin can be congenital or, more frequently, iatrogenic and the clinical presentation is heterogeneous. Respiratory tract fistulas can lead to severely reduced health-related quality of life and short survival. Therapy mainly relies on endoscopic surgical interventions but patients often require prolonged hospitalization and may develop complications. Therefore, more conservative regenerative medicine approaches, mainly based on lipotransfer, have also been investigated. Adipose tissue can be delivered either as unprocessed tissue, or after enzymatic treatment to derive the cellular stromal vascular fraction. In the current narrative review, we provide an overview of the main tissue/cell-based clinical studies for the management of various types of respiratory tract fistulas or injuries. Clinical experience is limited, as most of the studies were performed on a small number of patients. Albeit a conclusive proof of efficacy cannot be drawn, the reviewed studies suggest that grafting of adipose tissue-derived material may represent a minimally invasive and conservative treatment option, alternative to more aggressive surgical procedures. Knowledge on safety and tolerability acquired in prior studies can lead to the design of future, larger trials that may exploit innovative procedures for tissue processing to further improve the clinical outcome.

7-T MRI tracking of mesenchymal stromal cells after lung injection in a rat model

Background

Mesenchymal stromal cells (MSCs) are able to migrate and engraft at sites of inflammation, injuries, and tumours, but little is known about their fate after local injection. The purpose of this study is to perform MSC tracking, combining in vivo 7-T magnetic resonance imaging (MRI) and histological assessment, following lung injection in a rat model.

Methods

Five lungs were injected with ferumoxide-labelled MSCs and five with perfluorocarbon-labelled MSCs and underwent 7-T MRI. MRI acquisitions were recorded immediately (T₀), at 24 h (T₂₄) and/or 48 h (T₄₈) after injection. For each rat, labelled cells were assessed in the main organs by MRI. Target organs were harvested under sterile conditions from rats sacrificed 0, 24, or 48 h after injection and fixed for histological analysis via confocal and structured illumination microscopy.

Results

Ferumoxide-labelled MSCs were not detectable in the lungs, whereas they were not visible in the distant sites. Perfluorocarbon-labelled MSCs were seen in 5/5 injected lungs at T₀, in 1/2 at T₂₄, and in 1/3 at T₄₈. The fluorine signal in the liver was seen in 3/5 at T₀, in 1/2 at T24, and in 2/3 at T₄₈. Post-mortem histology confirmed the presence of MSCs in the injected lung.

Conclusions

Ferumoxide-labelled cells were not seen at distant sites; a linear decay of injected perfluorocarbon-labelled MSCs was observed at T₀, T₂₄, and T₄₈ in the lung. In more than half of the experiments, perfluorocarbon-labelled MSCs scattering to the liver was observed, with a similar decay over time as observed in the lung.