Does BioGlue contribute to anastomotic pseudoaneurysm after thoracic aortic surgery?

Aortic tissue pathology in reoperative post-dissection repair following prior use of BioGlue

AIM

The benefits of BioGlue as a surgical adjunct in aortic procedures have been demonstrated in several studies, but limited information is available regarding the associated histopathological findings of aortic tissue at the time of reoperation. The objective of this study was to assess, at reoperation, the histopathological characteristics of aortic tissue which has had BioGlue applied during a previous surgery.

METHODS

This prospective, single-center, single-arm study enrolled patients who were undergoing aortic reoperation and who had BioGlue used during previous aortic surgery. Histopathological assessment of aortic specimens obtained intraoperatively was performed on tissue that would have been removed independent of subject participation in the study.

RESULTS

A total of 11 patients were enrolled and based on gross assessment, excessive amounts of BioGlue had been applied during the initial surgery in 36.4% of cases. The samples with the greatest amount of residual BioGlue demonstrated moderate to marked inflammatory responses, while the remaining samples demonstrated minimal to moderate inflammatory responses. Calcification of residual BioGlue was noted in 4 cases. Substantial medial degeneration was associated with suture line dehiscence in 4 cases, some of which had a large quantity of residual BioGlue. No evidence of suture degradation was observed.

CONCLUSIONS

Cases with surgical anastomosis dehiscence were associated with substantial medial degeneration. While no histologic findings directly linked BioGlue to these degenerative changes, a contributory role cannot be excluded. Following the manufacturer's instructions for appropriate application of BioGlue is crucial to prevent potential complications.

BioGlue® is not associated with polypropylene suture breakage after aortic surgery

Objective

We have encountered broken or damaged polypropylene sutures (Prolene^®) at the anastomotic sites during aortic reoperations. Because a surgical sealant, bovine serum albumin-glutaraldehyde (BioGlue^®), was used in previous aortic surgery in some of these cases, we undertook this in vitro study to evaluate whether the use of BioGlue^® was associated with breakage of polypropylene sutures at the aortic anastomosis.

Materials and methods

The broken polypropylene sutures, anastomotic sites and aortic tissue at the location of suture breakage were visually inspected and evaluated intraoperatively. Six human cadaveric aortic samples were incised circumferentially and anastomosed proximally to a valved conduit with running 4–0 polypropylene sutures (Prolene^®). In the test group (n = 3), BioGlue^® was applied directly to the Prolene^® sutures at the anastomotic sites, while in the control group (n = 3) the anastomoses were not sealed with any surgical adhesive. The six samples were immersed in Dulbecco's phosphate buffered saline solution and mounted on a M-6 Six Position Heart Valve Durability Testing System and tested up to 120 million cycles for a 2-year period. During and upon completion of the testing, the integrity of Prolene^® sutures, the anastomosis and aortic tissues was regularly assessed by visual inspection.

Results

Intraoperative findings included a stretched and thin aortic wall (some with thrombus), a small cleft between the aortic tissue and the Dacron vascular graft. An excessive amount of BioGlue^® was often found around the anastomosis, with cracking material, but no signs of mechanical damage were observed in these cases. Upon visual inspection during and after in vitro testing, there was no apparent damage to the polypropylene sutures on the interior or exterior of the aortic anastomoses in any of the samples. No difference was observed in the physical integrity of the polypropylene sutures at anastomotic lines, the anastomoses and aortic tissues between the test and control samples.

Conclusions

The results of this study suggest that the use of BioGlue^® was not associated with breakage of the polypropylene sutures at the anastomotic sites after aortic dissection repair.

Surgical applications of intracorporal tissue adhesive agents: current evidence and future development

Introduction: Traditional mechanical closure techniques pose many challenges including the risk of infection, tissue reaction, and injury to both patients and clinicians. There is an urgent need to develop tissue adhesive agents to reform closure technique. This review examined a variety of tissue adhesive agents available in the market in an attempt to gain a better understanding of intracorporal tissue adhesive agents as medical devices.Areas covered: Fundamental principles and clinical determinants of the tissue adhesives were summarized. The available tissue adhesives for intracorporal use and their relevant clinical evidence were then presented. Lastly, the perspective of future development for intracorporal tissue adhesive were discussed. Clinical evidence shows current agents are efficacious as adjunctive measures to mechanical closure and these agents have been trialed outside of clinical indications with varied results.Expert opinion: Despite some advancements in the development of tissue adhesives, there is still a demand to develop novel technologies in order to address unmet clinical needs, including low tensile strength in wet conditions, non-controllable polimerization and sub-optimal biocompatibility. Research trends focus on producing novel adhesive agents to remit these challenges. Examples include the development of biomimetic adhesives, externally activated adhesives, and multiple crosslinking strategies. Economic feasibility and biosafety are limiting factors for clinical implementation.

Prevention of hemorrhagic complications during operations on the thoracic aorta

Aim. To assess the efficiency of guideline for the prevention of hemorrhagic complications in the early postoperative period.

Material and methods. In the period from 2008 to 2017, 166 patients with pathology of the thoracic aorta were operated. The patients were divided into 2 comparable groups: group 1 — patients with reconstructed aortic arch of the type “Hemiarch” (group “hemiarch”, n=90), group 2 — patients with fully reconstructed aortic arch (group “arch”, n=76). All operations were performed with artificial blood circulation, circulatory arrest with moderate hypothermia (25­28° C) and unilateral antegrade cerebral perfusion through the brachiocephalic trunk.

Results. The reconstructions of the thoracic aorta in patients of the “hemiarch” group were accompanied by significantly less period of artificial blood circulation (p=0,027), cardiac arrest period (p=0,012), duration of circulatory arrest (p=0,019), and duration of antegrade brain perfusion (p=0,021). The volume of discharge through the drainage was 350 [192;506] ml and 400 [250;723] ml in the “hemiarch” and “arch” groups, respectively (p=0,29). Patients of the “arch” group more often required transfusion of packed red cells (p=0,003), fresh frozen plasma (p=0,0006), platelet concentrate (p=0,002) in comparison with patients of the “hemiarch” group. At the same time, the frequency of bleeding requiring reoperation was comparable in both groups (5,6% versus 5,3%, p=0,969). The 30­day mortality also had no statistically significant differences in patients of the “hemiarch” and “arch” groups (3,3% versus 9,2%, p=0,119).

Conclusion. The frequency of hemorrhagic complications requiring reoperation in patients with a fully or partially reconstructed aortic arch does not have significant differences when using the guideline for preventing of hemorrhagic complications, which makes it possible to provide acceptable frequency of bleeding episodes and reoperations in the early postoperative period.

Cytocompatibility and mechanical properties of surgical sealants for cardiovascular applications

OBJECTIVES

The present study compared physical, mechanical, and biologic characteristics of 4 clinically available surgical sealants for cardiovascular repair.

METHODS

BioGlue (Cryolife Inc, Kennesaw, Ga), PreveLeak (Mallinckrodt Pharmaceuticals, St Louis, Mo), Tridyne VS (BD, Franklin Lakes, NJ), and Coseal (Baxter Healthcare Corporation, Westlake Village, Calif) were compared for the following properties: hydrated swelling, cytocompatibility, burst strength, biaxial stretching (elasticity), and in vitro degradation.

RESULTS

Sealants showed a wide range of swelling upon hydration. By gravimetric and volumetric measurement, swelling was greatest for Coseal followed by Tridyne VS, BioGlue, and PreveLeak. Tridyne VS was the most cytocompatible based on Alamar Blue assay results, supporting 85% cell survival compared with 36% to 39% survival with the other sealants. All sealants withstood pressure above mean arterial pressure (70-110 mm Hg) and physiologic systolic blood pressure (90-140 mm Hg) in an ex vivo arterial flow burst model; lowest peak pressure at failure was PreveLeak at 235 ± 48 mm Hg, and highest peak pressure at failure was BioGlue at 596 ± 72 mm Hg. Biaxial tensile testing showed no differences in elasticity between ex vivo porcine aorta and carotid arteries and Tridyne VS or Coseal, and BioGlue and PreveLeak were significantly stiffer. In vitro degradation time for Coseal was 6 days and 21 days for Tridyne VS. No degradation was observed in BioGlue or PreveLeak for 30 days.

CONCLUSIONS

Although all sealants withstood supraphysiologic arterial pressure, there were differences in characteristics that may be important in clinical outcome. Coseal degradation time was short compared with other sealants, whereas BioGlue and PreveLeak showed a significant compliance mismatch with native porcine carotid artery. Tridyne VS was significantly more cytocompatible than the other 3 sealants.