Treatment of Bronchopleural Fistula With Small Intestinal Mucosa and Fibrin Glue Sealant

Interventional bronchoscopy in pediatric pulmonary tuberculosis

INTRODUCTION

Lymphobronchial tuberculosis (TB) is common in children with primary TB and enlarged lymph nodes can cause airway compression of the large airways. If not treated correctly, airway compression can result in persistent and permanent parenchymal pathology, as well as irreversible lung destruction. Bronchoscopy was originally used to collect diagnostic samples; however, its role has evolved, and it is now used as an interventional tool in the diagnosis and management of complicated airway disease. Endoscopic treatment guidelines for children with TB are scarce.

AREAS COVERED

The role of interventional bronchoscopy in the diagnosis and management of complicated pulmonary TB will be discussed. This review will provide practical insights into how and when to perform interventional procedures in children with complicated TB for both diagnostic and therapeutic purposes. This discussion incorporates current scientific evidence and refers to adult literature, as some of the interventions have only been done in adults but may have a role in children. Limitations and future perspectives will be examined.

EXPERT OPINION

Pediatric pulmonary TB lends itself to endoscopic interventions as it is a disease with a good outcome if treated correctly. However, interventions must be limited to safeguard the parenchyma and prevent permanent damage.

Complicated intrathoracic tuberculosis: Role of therapeutic interventional bronchoscopy

In recent years bronchoscopy equipment has been improved with smaller instruments and larger size working channels. This has ensured that bronchoscopy offers both therapeutic and interventional options. As the experience of paediatric interventional pulmonologists continues to grow, more interventions are being performed. There is a scarcity of published evidence in the field of interventional bronchoscopy in paediatrics. This is even more relevant for complicated pulmonary tuberculosis (PTB). Therapeutic interventional bronchoscopy procedures can be used in the management of complicated tuberculosis, including for endoscopic enucleations, closure of fistulas, dilatations of bronchial stenosis and severe haemoptysis. Endoscopic therapeutic procedures in children with complicated TB may prevent thoracotomy. If done carefully these interventional procedures have a low complication rate.

Development of decellularization protocol for caprine small intestine submucosa as a biomaterial

Decellularized animal tissues have been proven to be promising biomaterials for various tissue engineering (TE) applications. Among various animal tissues, small intestine submucosa (SIS) has gained attention of many researchers due to its easy availability from the abattoir waste, excellent physicochemical and biological characteristics of a good biomaterial. In this study, Caprine SIS was decellularized to get decellularized caprine SIS (DG-SIS). For decellularization, several physical, chemical and enzymatic protocols have been described in the literature. To optimize the decellularization of caprine SIS, several decellularization protocol (DP), including an in-house developed by us, had been attempted, and effect of the different DPs on the obtained DG-SIS were assessed in terms of decellularization, physiochemical and biological properties. All the DPs differ in terms of decellularization, but three DPs where ionic detergent like sodium dodecyl sulphate (SDS) has been used, largely affect the native composition (e.g. glycosaminoglycans (GAGs)), biological properties and other physiochemical properties of the G-SIS as compared to the DP that uses hypertonic solution of potassium iodide (KI) and non-ionic detergent (TritonX-100). The obtained DG-SISs were fibrous, hemocompatible, biocompatible, hydrophilic, biodegradable and exhibited significant antibacterial activity. Therefore, the DG-SIS will be a prospective biomaterial for TE applications.

Management of children with tuberculous broncho-esophageal fistulae

INTRODUCTION

Broncho-esophageal fistula (BOF) is a rare complication of Mycobacterium tuberculosis (MTB). TB-associated BOF presents either as acute respiratory failure, aspiration pneumonia or as a complication of surgical decompression of thoracic lymph nodes.

METHODS

All children with TB- associated BOF were included. TB was diagnosed if MTB was cultured from respiratory secretions, Ziehl-Neelsen (ZN) smear was positive, GeneXpert MTB/RIF was positive or a chest radiograph revealed radiographic features typical of TB. BOF was diagnosed by a contrast swallow study and/or flexible bronchoscopy. Chest computed tomography (CT) scan was performed, if required.

RESULTS

Total of 20 children were diagnosed with TB-associated BOF between 1999 and 2019, with a 75% survival. A total of 85% BOF involved the left main bronchus. A total of 80% of patients were MTB culture or ZN smear-positive. Chest X-ray abnormalities included: extensive parenchymal disease (80%) and lymph gland enlargement (45%). CT features included visualization of the BOF (60%), esophageal air (73%) and pneumomediastinum (40%). BOF closure was achieved by surgical closure (46%), spontaneous closure (26%), fibrin glue (13%), and esophageal stent (13%). Multivariant regression analysis showed that C- reactive protein (CRP), albumin and CRP/albumin ratio were associated with mortality.

CONCLUSION

Most TB-associated BOF are left-sided. It presents either acutely, with respiratory failure, or with chronic respiratory symptoms of aspiration. Children requiring invasive ventilation have high mortality. Most TB-associated BOF requires surgical intervention, although the use of fibrin glue offers an attractive alternative option.

Successful endothelialization and remodeling of a cell-free small-diameter arterial graft in a large animal model

The large number of coronary artery bypass procedures necessitates development of off-the-shelf vascular grafts that do not require cell or tissue harvest from patients. However, immediate thrombus formation after implantation due to the absence of a healthy endothelium is very likely. Here we present the successful development of an acellular tissue engineered vessel (A-TEV) based on small intestinal submucosa that was functionalized sequentially with heparin and VEGF. A-TEVs were implanted into the carotid artery of an ovine model demonstrating high patency rates and significant host cell infiltration as early as one week post-implantation. At one month, a confluent and functional endothelium was present and the vascular wall showed significant infiltration of host smooth muscle cells exhibiting vascular contractility in response to vaso-agonists. After three months, the endothelium aligned in the direction of flow and the medial layer comprised of circumferentially aligned smooth muscle cells. A-TEVs demonstrated high elastin and collagen content as well as impressive mechanical properties and vascular contractility comparable to native arteries. This is the first demonstration of successful endothelialization, remodeling, and development of vascular function of a cell-free vascular graft that was implanted in the arterial circulation of a pre-clinical animal model.

Complete radiofrequency ablation of hepatolithiasis-associated cholangiocarcinoma and successful management of post-ablation bronchobiliary fistula

This report documented the use of radiofrequency ablation (RFA) in the treatment of hepatolithiasis-associated cholangiocarcinoma and cyanoacrylate glue in the management of post-ablation bronchobiliary fistula. A 47-year-old Chinese woman with 20 years history of extrahepatic and intrahepatic cholangiolithiasis and multiple hepatic segmentectomy, developed hepatolithiasis-associated cholangiocarcinoma. The tumor was successfully treated with RFA but patient developed bronchobiliary fistula. Cyanoacrylate glue was used for occluding the bronchobiliary fistula. CT scan at 3 months showed complete restoration of physiological separation between the biliary and bronchial system. Repeat CT scan showed complete tumor ablation with no signs of tumor recurrence 10 months after RFA. In conclusion, RFA may be a safe and effective treatment option for patients with hepatolithiasis-associated cholangiocarcinoma who are poor candidates for surgical resection. Protection of the integrity of the bile duct and diaphragm during RFA can minimize postoperative complications. In case of development of post-ablation bronchobiliary fistula, cyanoacrylate glue can be used to occlude the fistula, before surgical resection is considered.

Evaluation of small intestine grafts decellularization methods for corneal tissue engineering

Advances in the development of cornea substitutes by tissue engineering techniques have focused on the use of decellularized tissue scaffolds. In this work, we evaluated different chemical and physical decellularization methods on small intestine tissues to determine the most appropriate decellularization protocols for corneal applications. Our results revealed that the most efficient decellularization agents were the SDS and triton X-100 detergents, which were able to efficiently remove most cell nuclei and residual DNA. Histological and histochemical analyses revealed that collagen fibers were preserved upon decellularization with triton X-100, NaCl and sonication, whereas reticular fibers were properly preserved by decellularization with UV exposure. Extracellular matrix glycoproteins were preserved after decellularization with SDS, triton X-100 and sonication, whereas proteoglycans were not affected by any of the decellularization protocols. Tissue transparency was significantly higher than control non-decellularized tissues for all protocols, although the best light transmittance results were found in tissues decellularized with SDS and triton X-100. In conclusion, our results suggest that decellularized intestinal grafts could be used as biological scaffolds for cornea tissue engineering. Decellularization with triton X-100 was able to efficiently remove all cells from the tissues while preserving tissue structure and most fibrillar and non-fibrillar extracellular matrix components, suggesting that this specific decellularization agent could be safely used for efficient decellularization of SI tissues for cornea TE applications.

Effective treatment of post-pneumonectomy bronchopleural fistula by conical fully covered self-expandable stent

The aim of the study was to assess the feasibility, efficacy and safety of the use of a conical self-expandable stent for the treatment of post-pneumonectomy bronchopleural fistula (PPBPF). Between April 2008 and November 2010, six patients underwent treatment for the PPBPF by the introduction of a tracheobronchial conical fully covered self-expandable nitinol stent with the aim of excluding the bronchial dehiscence from the airflow. We secured the prosthesis to the tracheal mucosa with titanium helical fasteners tacks. Five patients presented with a bronchial fistula larger than 5 mm following right (4) or left (1) pneumonectomy. One patient had an anastomotic dehiscence after right tracheal sleeve pneumonectomy. A chest tube showed the absence of empyema in all cases. Immediate resolution of the bronchial air leak was obtained in all the patients. Permanent closure of the bronchial dehiscence without recurrence was achieved in all the patients at a mean follow-up time of 13 months (range 3-32). The bronchial stent was successfully removed in all patients without sequelae 71-123 days after its implantation. The use of the conical self-expandable Silmet(®) stent has proved to be an effective, safe and fast method to treat even large PPBPFs.

Experimental lung collapse following deployment of a self-expandable bronchial occluder in a rabbit model

OBJECTIVES

Closure of a bronchopleural fistula is required to prevent fatal empyema or aspiration pneumonia. The purpose of this study was to determine the feasibility and efficacy of bronchial occlusion with a self-expandable occluder to induce experimental lung collapse in a rabbit model.

METHODS

10 bronchial occluders (wine glass appearance; 8 mm in diameter and 15 mm in length) were implanted in the native left main bronchi of 10 rabbits via an endotracheal route. We analysed the following: (1) diameters and morphological changes of the bronchial occluders during follow-up; (2) percentage volume of the collapsed lung during follow-up; and (3) complications and gross pathology. 1-day and 2-week follow-up CT scans were routinely obtained. Rabbits were sacrificed 4 weeks after the experiment.

RESULTS

In all 10 rabbits, the bronchial occluders were successfully implanted and were completely expanded within 2 weeks. Complete collapse of the left lung occurred in three rabbits on day 1 and in an additional two rabbits 2 weeks following implantation. Two other rabbits maintained the percentage volume of the collapsed lung between 51% and 99% during follow-up; the other three rabbits had <50% during follow-up. Pneumothoraces occurred in nine rabbits, but completely resolved at the 2-week follow-up. Right lung herniation across the midline progressed 2 weeks after occluder implantation.

CONCLUSION

Placement of self-expandable occluders in a rabbit bronchus model was feasible and showed a potential to induce artificial lung collapse. While pneumothoraces were common, they resolved during follow-up.

Perianal fistulae in Crohn's Disease: current and future approaches to treatment

: affecting sphincter integrity and continence. Traditional surgical and medical approaches are not without their limitations and may result in either comorbidity, such as fecal incontinence, or incomplete healing of the fistulae. Over the last 2 decades these limitations have led to a paradigm shift toward the use of biomaterials, and more recently cell-based therapies, which have met with variable degrees of success. This review discusses the traditional and current methods of treatment, as well as emerging and possible alternative approaches that may improve fistula healing.

Microporous collagen spheres produced via thermally induced phase separation for tissue regeneration

Collagen is an abundant protein found in the extracellular matrix of many tissues. Due to its biocompatibility, it is a potentially ideal biomaterial for many tissue engineering applications. However, harvested collagen often requires restructuring into a three-dimensional matrix to facilitate applications such as implantation into poorly accessible tissue cavities. The aim of the current study was to produce a conformable collagen-based scaffold material capable of supporting tissue regeneration for use in wound repair applications. Microporous collagen spheres were prepared using a thermally induced phase separation (TIPS) technique and their biocompatibility was assessed. The collagen spheres were successfully cross-linked with glutaraldehyde vapour, rendering them mechanically more stable. When cultured with myofibroblasts the collagen spheres stimulated a prolonged significant increase in secretion of the angiogenic growth factor, vascular endothelial growth factor (VEGF), compared with cells alone. Control polycaprolactone (PCL) spheres failed to stimulate a similar prolonged increase in VEGF secretion. An enhanced angiogenic effect was also seen in vivo using the chick embryo chorioallantoic membrane assay, where a significant increase in the number of blood vessels converging towards collagen spheres was observed compared with control PCL spheres. The results from this study indicate that microporous collagen spheres produced using TIPS are biologically active and could offer a novel conformable scaffold for tissue regeneration in poorly accessible wounds.

Tratamento endoscópico de fístulas da árvore traqueobrônquica com dispositivos para a correção de defeitos do septo interatrial: resultados preliminares

As fístulas da árvore traqueobrônquica, sejam elas broncopleurais ou traqueoesofágicas, apresentam etiologia multifatorial, com incidência variável na literatura. Em geral, apresentam alta morbidade e mortalidade, com indicação formal de correção cirúrgica. Entretanto, a condição clínica dos pacientes muitas vezes não permite uma reintervenção cirúrgica de grande porte. Além disso, as tentativas de fechamento endoscópico raramente têm sucesso, principalmente em fístulas de grande diâmetro. Relatamos os casos de três pacientes submetidos ao fechamento endoscópico de fístulas, sendo duas maiores que 10 mm, com a aplicação de dispositivos oclusores utilizados na cardiologia intervencionista, de forma minimamente invasiva e com resultados iniciais positivos. Esses dados sinalizam que essa pode ser uma técnica promissora na resolução de fístulas da árvore traqueobrônquica.

Endobronchial closure of total bronchopleural fistula with Occlutech Figulla ASD N device

Bronchopleural fistula may be treated by medical, endoscopic, and surgical techniques, but large fistulas remain a challenge to be closed using endoscopic techniques. We describe the endoscopic closure of a bronchial total fistula with the Occlutech Figulla ASD N device (International Occlutech AB, Helsingborg, Sweden), originally designed for closure of an atrial septal defect. The procedure was conducted without general anesthesia or rigid bronchoscopy, bronchography, or radioscopy. An immediate reduction in the air leak was observed and also later on bronchoscopy, as the device was almost covered by granulation tissue. The endobronchial technique described seems to be safe and effective to manage large bronchopleural fistulas.

Fibrin glue closure of persistent bronchopleural fistula following pneumonectomy for post-tuberculosis bronchiectasis

We report a case of a persistent bronchopleural fistula following a pneumonectomy for post-tuberculosis bronchiectasis. The patient had two unsuccessful surgical attempts at closing of the fistula. Further surgical attempts were technically were not possible. Bronchoscopic closure was achieved by injecting human fibrin glue into the fistula via a catheter. Closure of the broncho-pleural fistula was confirmed by repeated ventilation scan over a period of 2 months. Endoscopic closure of small bronchopleural fistulae is an attractive option in children with significant underlying lung disease.