Aortic wall alterations after use of gelatin-resorcinol-formalin glue

Abdominal Stent-Graft Treatment of Ascending Aortic Pseudoaneurysm Following Transcatheter Aortic Valve Implantation

An ascending aortic pseudoaneurysm is a potentially lethal complication in aortic procedures. We present a hybrid approach using surgical innominate artery access and the endovascular insertion of an abdominal stent-graft extension to successfully treat a zone 0 ascending aortic pseudoaneurysm in a patient with a prior valve-in-valve transcatheter aortic valve implantation.

Efficacy of Total Aortic Arch Replacement Combined with Frozen Elephant Trunk in Aortic Reoperation

Background

The aim of this study was to estimate the long-term efficacy of total aortic arch replacement combined with the frozen elephant trunk (TAR+FET) technique for aortic disease following a prior cardiac surgery procedure.

Material/Methods

We performed TAR+FET for 118 patients for major vessel disease following a prior cardiac procedure with median sternotomy incision. All patients were divided into 5 groups: in group A, the prior major procedure was aortic valve replacement (AVR); in group B, the prior major procedure was isolated ascending aorta replacement; in group C, the prior major procedure was aortic root replacement; in group D, the prior major procedure was aortic arch replacement or intervention; and in group E, the prior major procedure was ‘other’ cardiac operative procedure. The long-term follow-up visit results were estimated using the Kaplan-Meier method.

Results

The 30-day mortality rate after the operation was 13.6% (16/118) – 2 died in group A, 1 in group B, 8 in group C, 4 in group D, and 1 in group E. Follow-up visits were completed in 99% of patients. The mean follow-up time was 47.6±36.3 months and 12 patients had died by follow-up, so the total long-term survival rate was 76.3%. One-year survival rates of the 5 groups were 85% (group A), 93.8% (group B), 82.3% (group C), 50% (group D), and 50% (group E), respectively. Five-year survival rates of the 5 groups were 85%, 93.8%, 80.6%, 50%, and 50%, respectively.

Conclusions

The TAR+FET technique is feasible and efficacious for aortic reoperation in patients who previously underwent cardiac surgery since the short-term mortality in patients with recurrent aortic arch disease after cardiac surgery is not high.

Bioadhesives for internal medical applications: A review

Bioadhesives such as tissue adhesives, hemostatic agents, and tissue sealants have gained increasing popularity in different areas of clinical operations during the last three decades. Bioadhesives can be categorized into internal and external ones according to their application conditions. External bioadhesives are generally applied in topical medications such as wound closure and epidermal grafting. Internal bioadhesives are mainly used in intracorporal conditions with direct contact to internal environment including tissues, organs and body fluids, such as chronic organ leak repair and bleeding complication reduction. This review focuses on internal bioadhesives that, in contrast with external bioadhesives, emphasize much more on biocompatibility and adhesive ability to wet surfaces rather than on gluing time and intensity. The crosslinking mechanisms of present internal bioadhesives can be generally classified as follows: 1) chemical conjugation between reactive groups; 2) free radical polymerization by light or redox initiation; 3) biological or biochemical coupling with specificity; and 4) biomimetic adhesion inspired from natural phenomena. In this review, bioadhesive products of each class are summarized and discussed by comparing their designs, features, and applications as well as their prospects for future development.

STATEMENT OF SIGNIFICANCE

Despite the emergence of numerous novel bioadhesive formulations in recent years, thus far, the classification of internal and external bioadhesives has not been well defined and universally acknowledged. Many of the formulations have been proposed for treatment of several diseases even though they are not applicable for such conditions. This is because of the lack of a systematic standard or evaluation protocol during the development of a new adhesive product. In this review, the definition of internal and external bioadhesives is given for the first time, and with a focus on internal bioadhesives, the criteria of an ideal internal bioadhesive are adequately discussed; this is followed by the review of recently developed internal bioadhesives based on different gluing mechanisms.

Early Failure of Surgical Angioplasty with Tissue Glue: A Word of Caution

A 43-year-old woman with critical stenosis of the left main stem was managed with saphenous vein angioplasty using BioGlue. She developed severe myocardial ischemia postoperatively, probably due to external compression exerted on the patch by the adhesive material, and required emergency coronary artery bypass grafting.

Pseudoaneurysm fistulized into pulmonary artery 13 years after aortic surgery

Pseudoaneurysm formation some years after aortic root or ascending aorta surgery, complicated by fistula formation through a branch of the pulmonary artery, is a rare condition described only in case reports. We describe a case of this rare complication in a 58-year-old man, which occurred 13 years after aortic surgery and was characterized by a huge pseudoaneurysm of 70 mm that fistulized into the right pulmonary artery, causing a life-threatening situation.

Surgical Materials: Current Challenges and Nano-enabled Solutions

Surgical adhesive biomaterials have emerged as substitutes to sutures and staples in many clinical applications. Nano-enabled materials containing nanoparticles or having a distinct nanotopography have been utilized for generation of a new class of surgical materials with enhanced functionality. In this review, the state of the art in the development of conventional surgical adhesive biomaterials is critically reviewed and their shortcomings are outlined. Recent advancements in generation of nano-enabled surgical materials with their potential future applications are discussed. This review will open new avenues for the innovative development of the next generation of tissue adhesives, hemostats, and sealants with enhanced functionality for various surgical applications.

Root replacement with stentless Freestyle bioprostheses for active endocarditis: a single centre experience

OBJECTIVES

Few studies have examined the use of stentless Freestyle bioprostheses in patients with active valve endocarditis (VE). The aim of this study was to evaluate outcomes of stentless Freestyle bioprostheses in patients undergoing full-root replacement.

METHODS

From February 2000 to June 2010, 180 patients with VE underwent cardiac surgery at our institution, of which 71 (39.5%) had prosthetic VE. Eighteen patients underwent full-root replacement with Freestyle bioprostheses: 3 patients (16%) had native aortic VE, 14 (78%) had aortic prosthetic VE and 1 (6%) had mitral and aortic prosthetic VE. Mean age was 66.7 ± 10.1, M/F: 6/12, mean logistic EuroSCORE 36.4 ± 21.6. Eight patients (42%) underwent concomitant procedures (two mitral valve replacements, three ascending aorta replacements, one coronary artery bypass grafting (CABG), one ventricular septal disease (VSD) repair, one CABG + ascending aorta + VSD repair).

RESULTS

Two patients (11%) died in-hospital. At the median follow-up of 24 months (range 1-113 months), no death occurred and freedom from reoperation was 87.5% (2 patients for aortic root pseudo-aneurysm at 1 and 23 months). All patients are in NYHA functional class I and have satisfactory echocardiographic data (EF 54.3 ± 8%, peak and mean trans-prosthetic gradients 12 ± 6.7 mmHg and 7.5 ± 3.6 mmHg) with 100% freedom recurrence of VE.

CONCLUSIONS

Our experience shows that root replacement with Freestyle stentless bioprostheses in patient with VE, is associated with low rates of early and mid-term mortality, good haemodynamic performance and low rates of valve-related morbidity as well as low recurrence of infection.

Postsurgical aortic false aneurysm: pathogenesis, clinical presentation and surgical strategy

Postsurgical aortic false aneurysm occurs in less than 0.5% of all cardiac surgical cases and its management is a challenge in terms of preoperative evaluation and surgical approach. Although infections are well recognized as risk factors, technical aspects of a previous operation may have a role in pseudoaneurysm formation. The risk factors and clinical presentation of pseudoaneurysms and the surgical strategy are revisited in this article.

Reoperations for aortic false aneurysms after cardiac surgery

BACKGROUND

Aortic false aneurysm is a rare complication after cardiac surgery. Aortic dissection, infection, arterial wall degeneration, and poor surgical technique are recognized as risk factors for the occurrence of postsurgical false aneurysm. Despite some recent reports about percutaneous false aneurysm exclusion, a complex surgical reoperation is needed in most of the cases.

METHODS

We retrospectively reviewed our experience in 43 patients who received a reoperation for postsurgical aortic false aneurysm in the last 14 years. Thirty-three patients were male. The mean age was 60 ± 12 years. Most of the patients received prior aortic surgery on the aortic root, the ascending aorta, the aortic arch, and the descending thoracic aorta (38 patients). False aneurysm was diagnosed during follow-up evaluation in the absence of any symptoms in 23 cases. Univariate and multivariate analyses on 18 perioperative variables were performed.

RESULTS

In-hospital mortality was 6.9% (3 patients). The postoperative course was complicated in 17 cases (39%). At multivariate analysis, a preoperative history of coronary artery disease and postoperative sepsis were independent risk factors for hospital mortality. Survival rates at 1, 5, and 10 years were 94%, 79%, and 68%, respectively. Freedom from reoperation was 86% at 1 year and 72% at 5 and 10 years.

CONCLUSIONS

Despite a high postoperative complication rate, a reoperation for postsurgical aortic false aneurysm can be performed with acceptable mortality and good mid-term and long-term outcomes.

On the mechanical properties of bovine serum albumin (BSA) adhesives

Biological adhesives, natural and synthetic, are of current active interest. These adhesives offer significant advantages over traditional sealant techniques, in particular, they are easier to use, and can play an integral part in the healing mechanism of tissue. Thus, biological adhesives can play a major role in medical applications if they possess adequate mechanical behavior and stability over time. In this work, we report on the method of preparation of bovine serum albumin (BSA) into a biological adhesive. We present quantitative measurements that show the effect of BSA concentration and cross-linker content on the bonding strength of BSA adhesive to wood. A comparison is then made with synthetic poly(glycidyl methacrylate) (PGMA) adhesive, and a commercial cyanoacrylate glue, which was used as a control adhesive. In addition, BSA samples were prepared and characterized for their water content, tensile strength, and elasticity. We show that on dry surface, BSA adhesive exhibits a high bonding strength that is comparable with non-biological commercial cyanoacrylate glues, and synthetic PGMA adhesive. Tensile testing on wet wood showed a slight increase in the bonding strength of BSA adhesive, a considerable decrease in the bonding strength of cyanoacrylate glue, and negligible adhesion of PGMA. Tests performed on BSA samples demonstrate that initial BSA concentration and final water content have a significant effect on the stress-strain behavior of the samples.

Autologous glue: part of the sticky mystery unraveled

OBJECTIVE

The aim of the study was to evaluate the safety and efficacy of an autologous surgical tissue adhesive.

METHODS

Autologous glue was made out of canine concentrated plasma proteins mixed with 7.5% glutaraldehyde. Tensile strength and cytotoxicity of the autologous glue were tested. In a dog model, 8 transectioned iliac arteries were reanastomosed by using the animal's glue as the sole fixation method. After 120 days, all animals were angiographically controlled for patency and killed for histologic and immunohistochemical examination of the anastomosis.

RESULTS

The autologous glue showed sufficient tensile strength (557 +/- 135 N/mm2). The elasticity of the glue is influenced by variations of concentrations in both proteins and glutaraldehyde. Glutaraldehyde remained cytotoxic, even at low concentrations of 2.5%. All operative procedures were successful. Angiographs performed before animal death showed all but 1 vessel to be patent and showed manifest compression signs in 3 anastomoses. Histological examination revealed only a foreign-body reaction adjacent to the surface of the glue. The autologous glue does not trigger any immune response on immunochemistry. Because fibroblastic neo-endothelial lining was near to normal, potential glutaraldehyde leaching does not seem too harmful for the vascular juncture in the dog model.

CONCLUSIONS

Autologous glutaraldehyde glue has been used successfully as a vascular adhesive. In contrast to our previous studies with heterologous glue, we did not find a fierce acute inflammatory reaction indicating immune triggering. Nevertheless, glutaraldehyde remains a cytotoxic cross-linker. It is yet not known whether autologous glutaraldehyde glue can be used safely in clinical practice.

Long-term effects in distal coronary anastomoses using different adhesives in a porcine off-pump model

OBJECTIVE

Adhesives are useful supplements to seal distal coronary anastomoses, particularly in patients who receive less-invasive coupling techniques. Information regarding long-term structural effects after application, however, is limited. The purpose of this large animal study was to examine the effects of 3 different commercially available surgical adhesives.

METHODS

Twelve end-to-side anastomoses were created between the left internal thoracic artery and the left anterior descending coronary artery in a porcine beating heart model. Three different adhesives were applied externally and circumferentially to the anastomosis site. In group I (n = 4) gelatin-resorcinol-formaldehyde glue (Cardial, Technopole, Sainte-Etienne, France), in group II (n = 4) n-butyl-2-cyanoacrylate glue, and in group III (n = 4) albumin-glutaraldehyde glue were used. All anastomoses were examined intraoperatively by flow measurement. After 3 months the anastomoses were reassessed for patency and the vessels were evaluated histologically.

RESULTS

By means of 4 stay sutures and subsequent glue application, anastomoses could be created successfully on the first attempt in all animals. Perioperative flow through the left internal thoracic artery was similar in all groups. In 4 animals an additional suture was placed to control bleeding. After 3 months, the patency rate was 83.3% (10/12). In group I all anastomoses were patent whereas in both groups II and III one anastomosis was occluded. None of the adhesives caused impaired vessel wall healing but they did demonstrate moderate-to-dense adhesions to the surrounding tissue. On histologic examination, gelantin-resorcinol-formaldehyde glue exhibited minimal tissue reaction (foreign-body granuloma) whereas n-butyl-2-cyanoacrylate glue showed moderate reaction. In contrast, albumin-glutaraldehyde glue caused severe inflammatory reaction with extensive fibroblastic proliferation.

CONCLUSION

Construction of an end-to-side internal thoracic artery-coronary artery sleeve anastomosis using adhesives was feasible in the pig. Among the tissue adhesives used in this study, gelantin-resorcinol-formaldehyde glue appeared to be superior to cyanoacrylate and albumin-glutaraldehyde glue. The latter one, however, caused severe adverse histologic effects and thus cannot be recommended for bonding coronary anastomoses.

Aortic root replacement after previous surgical intervention on the aortic valve, aortic root, or ascending aorta

BACKGROUND

Aortic root replacement after a previous operation on the aortic valve, aortic root, or ascending aorta remains a major challenge.

METHODS

Records of 56 consecutive patients (44 men; mean age, 56.4 +/- 13.6 years) undergoing reoperative aortic root replacement between June 1994 and June 2005 were reviewed retrospectively.

RESULTS

Reoperation was performed 9.4 +/- 6.7 years after the last cardiac operation. Indications for reoperation were true aneurysm (n = 14 [25%]), false aneurysm (n = 10 [18%]), dissection or redissection (n = 9 [16%]), structural or nonstructural valve dysfunction (n = 10 [18%]), prosthetic valve-graft infection (n = 12 [21%]), and miscellaneous (n = 1 [2%]). Procedures performed were aortic root replacement (n = 47 [84%]), aortic root replacement plus mitral valve procedure (n = 5 [9%]), and aortic root replacement plus arch replacement (n = 4 [7%]). In 14 (25%) patients coronary artery bypass grafting had to be performed unexpectedly during the same procedure or immediately after the procedure to re-establish coronary perfusion. Hospital mortality reached 17.9% (n = 10). Multivariate logistic regression analysis revealed the need for unplanned perioperative coronary artery bypass grafting as the sole independent risk factor for hospital death (P = .005). Actuarial survival was 83.8% +/- 4.9% at 1 month, 73.0% +/- 6.3% at 1 year, and 65.7% +/- 9.0% at 5 years after the operation. One patient had recurrence of endocarditis 6.7 months after the operation and required repeated homograft aortic root replacement.

CONCLUSION

Reoperative aortic root replacement remains associated with a high postoperative mortality. The need to perform unplanned coronary artery bypass grafting during reoperative aortic root replacement is a major risk factor for hospital death. The optimal technique for coronary reconstruction in this setting remains to be debated.

BioGlue: albumin/glutaraldehyde sealant in cardiac surgery

BioGlue is a commercially available sealant manufactured by Cryolife (Atlanta, GA) as a hemostatic adjunct for cardiac and vascular surgery. This type of sealant has evolved conceptually from the gelatin resorcinol formalin glue (GRF or "French Glue") in the sense that it is devised not only to act a sealant but also as an agent to strengthen friable tissues, particularly in acute aortic dissection. In fact, the initial availability of BioGlue in the United States was under an FDA humanitarian device exemption for use in acute aortic dissection. This novel regulatory strategy expedited clinical use of BioGlue in acute aortic dissection and was permissible because of the small number of patients (less than 4000 per annum) in the potential treatment population. In this article, we will discuss the mechanism of action and composition of this agent, preclinical experience, the results of a prospective randomized trial as well as the results of our initial experience with BioGlue at MGH.