Intraoperative bronchial stump air leak control by Progel® application after pulmonary lobectomy

In vivo comparative assessments on pleural adhesive effects of three commercially available sealants

Objective

Surgical sealant, which is used for the reinforcement of suture lines, has been widely used in lung-resection surgeries with the aim of reducing postoperative morbidity; however, it may exacerbate surgical-site adhesion, creating the risks of restrictive thoracic movement and a difficult entrance for redo operation. We aimed to assess the pleural adhesive effects of 3 frequently used surgical sealants, (1) fibrin glue (fibrin), (2) a composite of polyethylene glycol and human serum albumin (PEG/HSA), and (3) bioabsorbable polyglycolic acid felt (PGA), in an in vivo setting.

Methods

Eighty-one rats were randomly assigned to 3 experimental groups-fibrin, PEG/HSA, and PGA. After intrapleural application of the sealants, the extent and severity of adhesion and inflammation were quantitatively compared among the 3 groups at 2, 4, and 8 weeks.

Results

The scores for both the extent and severity of adhesion were significantly greater in the PGA group than the other 2 groups throughout postoperative period (P < .001 for all). Although both scores in the PES/HSA and fibrin groups were 0 at 2 weeks, the fibrin group showed significantly greater scores than the PES/HSA group thereafter (P < .001 for all). Trends in inflammation scores were similar of those of adhesion scores, favoring the PES/HSA group followed by the fibrin group (P < .001 for all).

Conclusions

Among 3 commonly used sealants, PEA/HSA showed least degree of adhesion/inflammation compared with fibrin and PGA, whereas PGA demonstrated greatest degrees of adhesion/inflammation throughout a postoperative course of 8 weeks in an in vivo model.

Leveraging the pleural space for anticancer therapies in pleural mesothelioma

Most patients with pleural mesothelioma (PM) present with symptomatic pleural effusion. In some patients, PM is only detectable on the pleural surfaces, providing a strong rationale for intrapleural anticancer therapy. In modern prospective studies involving expert radiological staging and specialist multidisciplinary teams, the population incidence of stage I PM (an approximate surrogate of pleura-only PM) is higher than in historical retrospective series. In this Viewpoint, we advocate for the expansion of intrapleural trials to serve these patients, given the paucity of data supporting licensed systemic therapies in this setting and the uncertainties involved in surgical therapy. We begin by reviewing the unique anatomical and physiological features of the PM-bearing pleural space, before critically appraising the evidence for systemic therapies in stage I PM and previous intrapleural PM trials. We conclude with a summary of key challenges and potential solutions, including optimal trial designs, repurposing of indwelling pleural catheters, and new technologies.

Air leak and intraoperative bleeding in thoracic surgery: a Delphi consensus among the members of Italian society of thoracic surgery

Background

Persistent air leak and the management of intraoperative blood loss are common threats in thoracic surgical practice. The availability of new procedures, technology and materials is constantly evolving topical hemostats and surgical sealants must be added to this toolkit. Topical hemostats and surgical sealants differ according to their chemical nature and physical characteristics, to their origin and mechanism of action, regulatory/registration and vigilance paths. A Delphi consensus was set to highlight the different points of view on the use of topical haemostatic products and sealants among the members of Italian Society of thoracic surgery.

Methods

The board was formed by a group of five Italian experts; in the first phase after a careful review of the scientific literature and two rounds, the board finally generated 16 consensus statements for testing across a wider audience. During the second phase, the statements were collated into a questionnaire, which was electronically sent to a panel of 46 Italian surgeons, experts in the field.

Results

Out of 46 Italian surgeons, 33 (72%) panel members responded to the Delphi questionnaire. All the items reached a positive consensus, with elevated levels of agreement, as demonstrated by the presence of a 100% consensus for nine items. For the remaining 7 statements the minimum level of consent was 88% (29 participants approved the statement and 4 disagreed) and the maximum was 97% (32 participants approved the statement and 1 was in disagreement).

Conclusions

The present Delphi analysis shows that air leak and intraoperative bleeding are clinical problems well known among thoracic surgeons. Nevertheless, the aim of the scientific societies and of the group of experts is to execute the education activities in the surgery community. This Delphi survey suggest the need of wider and updated scientific information about technical and registration characteristics of most recent technologic solutions, such as the of topical hemostats and surgical sealants to provide healthcare and administrative staff with the opportunity to work and interact through a common and shared language and eventually to guarantee minimal requirements of assistance.

Successful Closure of Post-pneumonectomy Bronchopleural Fistula With Suture Repair Reinforced With Porcine Acellular Dermal Matrix (Permacol) and Hydrogel Sealant (Progel): A Case Report

Bronchopleural fistula (BPF) is a feared and potentially life-threatening complication of pneumonectomy. Clinical features such as a productive cough and subcutaneous emphysema raise suspicion of BPF with CT imaging and bronchoscopy providing a definitive diagnosis. In light of the significant morbidity and mortality associated with the condition, a significant proportion of cases necessitate surgical repair of the bronchial stump.

Currently, there is no consensus on optimal surgical strategy. Traditionally, various vascularised tissue flaps, including pericardial fat pad, omentum, and muscle, have been used to buttress the repaired stump, with varying success rates. In light of this, novel approaches have been devised with the aim of achieving more consistent surgical outcomes. In this case report, we describe a novel approach to reinforcing the suture repair using porcine dermal collagen matrix (Permacol, Medtronic, Minneapolis, MN) and hydrogel sealant (Progel, BD, Franklin Lakes, NJ) to achieve successful closure of a BPF in an adult male patient following pneumonectomy for squamous cell carcinoma.

The use of porcine dermal collagen matrix covered with hydrogel sealant is a viable alternative to traditional BPF closure strategies and can achieve good patient outcomes. This technique has several benefits including cost-effectiveness and sparing of native tissues, and it is technically straightforward. Further studies are required to compare the clinical outcomes of this and other novel techniques with traditional BPF closure approaches.

Physico-mechanical Characterization of Liquid versus Solid Applications of Visible Light Cross-Linked Tissue Sealants

The limitations of commercially available tissue sealants have resulted in the need for a new tissue adhesives with adequate adhesion, improved mechanical properties, and innocuous degradation products. To address current limitations, a visible light cross-linking method for the preparation of hydrogel tissue sealants, based on natural polymers (chitosan or alginate), is presented. Water-soluble chitosan was generated via modification with vinyl groups. To form hydrogels, alginate and chitosan were cross-linked by green light illumination, with or without the use of a bifunctional cross-linker. Evaluation of the mechanical properties through rheological characterization demonstrated an increased viscosity of polymer blends, and differences in shear moduli despite similar gelation points upon photo-cross-linking. A comparative study on the burst pressure properties of liquid versus solid material applications was performed to determine if the tissue sealants can perform under physiological lung pressures and beyond using different application methods. Higher burst pressure values were obtained for the sealants applied as a liquid compared to the solid application. The hydrogel tissue sealants revealed no cytotoxic effects toward primary human mesenchymal stem cells. This is the first report of a direct comparison between hydrogel tissue sealants of the same formulation applied in liquid versus solid form.

Anticancer Therapeutic Alginate-Based Tissue Sealants for Lung Repair

Injury to the connective tissue that lines the lung, the pleura, or the lung itself can occur from many causes including trauma or surgery, as well as lung diseases or cancers. To address current limitations for patching lung injuries, to stop air or fluid leaks, an adherent hydrogel sealant patch system was developed, based on methacrylated alginate (AMA) and AMA dialdehyde (AMA-DA) blends, which is capable of sealing damaged tissues and sustaining physiological pressures. Methacrylation of alginate hydroxyl groups rendered the polysaccharide capable of photo-cross-linking when mixed with an eosin Y-based photoinitiator system and exposed to visible green light. Oxidation of alginate yields functional aldehyde groups capable of imine bond formation with proteins found in many tissues. The alginate-based patch system was rigorously tested on a custom burst pressure testing device. Blending of nonoxidized material with oxidized (aldehyde modified) alginates yielded patches with improved burst pressure performance and decreased delamination as compared with pure AMA. Human mesothelial cell (MeT-5A) viability and cytotoxicity were retained when cultured with the hydrogel patches. The release and bioactivity of doxorubicin-encapsulated submicrospheres enabled the fabrication of drug-eluting adhesive patches and were effective in decreasing human lung cancer cell (A549) viability.