Safety and efficacy of currently available fibrin tissue adhesives

Fibrin sealants for the prevention of postoperative pancreatic fistula following pancreatic surgery

BACKGROUND

Postoperative pancreatic fistula (POPF) is one of the most frequent and potentially life-threatening complications following pancreatic surgery. Fibrin sealants have been used in some centres to reduce POPF rate. However, the use of fibrin sealant during pancreatic surgery is controversial. This is an update of a Cochrane Review last published in 2020.

OBJECTIVES

To evaluate the benefits and harms of fibrin sealant use for the prevention of POPF (grade B or C) in people undergoing pancreatic surgery compared to no fibrin sealant use.

SEARCH METHODS

We searched CENTRAL, MEDLINE, Embase, two other databases, and five trials registers on 09 March 2023, together with reference checking, citation searching, and contacting study authors to identify additional studies.

SELECTION CRITERIA

We included all randomised controlled trials (RCTs) that compared fibrin sealant (fibrin glue or fibrin sealant patch) versus control (no fibrin sealant or placebo) in people undergoing pancreatic surgery.

DATA COLLECTION AND ANALYSIS

We used standard methodological procedures expected by Cochrane.

MAIN RESULTS

We included 14 RCTs, randomising 1989 participants, comparing fibrin sealant use versus no fibrin sealant use for different locations: stump closure reinforcement (eight trials), pancreatic anastomosis reinforcement (five trials), or main pancreatic duct occlusion (two trials). Six RCTs were carried out in single centres; two in dual centres; and six in multiple centres. One RCT was conducted in Australia; one in Austria; two in France; three in Italy; one in Japan; two in the Netherlands; two in South Korea; and two in the USA. The mean age of the participants ranged from 50.0 years to 66.5 years. All RCTs were at high risk of bias. Application of fibrin sealants to pancreatic stump closure reinforcement after distal pancreatectomy We included eight RCTs involving 1119 participants: 559 were randomised to the fibrin sealant group and 560 to the control group after distal pancreatectomy. Fibrin sealant use may result in little to no difference in the rate of POPF (risk ratio (RR) 0.94, 95% confidence interval (CI) 0.73 to 1.21; 5 studies, 1002 participants; low-certainty evidence) and overall postoperative morbidity (RR 1.20, 95% CI 0.98 to 1.48; 4 studies, 893 participants; low-certainty evidence). After fibrin sealant use, approximately 199 people (155 to 256 people) out of 1000 developed POPF compared with 212 people out of 1000 when no fibrin sealant was used. The evidence is very uncertain about the effect of fibrin sealant use on postoperative mortality (Peto odds ratio (OR) 0.39, 95% CI 0.12 to 1.29; 7 studies, 1051 participants; very low-certainty evidence) and total length of hospital stay (mean difference (MD) 0.99 days, 95% CI -1.83 to 3.82; 2 studies, 371 participants; very low-certainty evidence). Fibrin sealant use may reduce the reoperation rate slightly (RR 0.40, 95% CI 0.18 to 0.90; 3 studies, 623 participants; low-certainty evidence). Serious adverse events were reported in five studies (732 participants), and there were no serious adverse events related to fibrin sealant use (low-certainty evidence). The studies did not report quality of life or cost-effectiveness. Application of fibrin sealants to pancreatic anastomosis reinforcement after pancreaticoduodenectomy We included five RCTs involving 519 participants: 248 were randomised to the fibrin sealant group and 271 to the control group after pancreaticoduodenectomy. The evidence is very uncertain about the effect of fibrin sealant use on the rate of POPF (RR 1.34, 95% CI 0.72 to 2.48; 3 studies, 323 participants; very low-certainty evidence), postoperative mortality (Peto OR 0.24, 95% CI 0.05 to 1.06; 5 studies, 517 participants; very low-certainty evidence), reoperation rate (RR 0.74, 95% CI 0.33 to 1.66; 3 studies, 323 participants; very low-certainty evidence), and total hospital cost (MD -1489.00 US dollars, 95% CI -3256.08 to 278.08; 1 study, 124 participants; very low-certainty evidence). After fibrin sealant use, approximately 130 people (70 to 240 people) out of 1000 developed POPF compared with 97 people out of 1000 when no fibrin sealant was used. Fibrin sealant use may result in little to no difference both in overall postoperative morbidity (RR 1.02, 95% CI 0.87 to 1.19; 4 studies, 447 participants; low-certainty evidence) and in total length of hospital stay (MD -0.33 days, 95% CI -2.30 to 1.63; 4 studies, 447 participants; low-certainty evidence). Serious adverse events were reported in two studies (194 participants), and there were no serious adverse events related to fibrin sealant use (very low-certainty evidence). The studies did not report quality of life. Application of fibrin sealants to pancreatic duct occlusion after pancreaticoduodenectomy We included two RCTs involving 351 participants: 188 were randomised to the fibrin sealant group and 163 to the control group after pancreaticoduodenectomy. The evidence is very uncertain about the effect of fibrin sealant use on postoperative mortality (Peto OR 1.41, 95% CI 0.63 to 3.13; 2 studies, 351 participants; very low-certainty evidence), overall postoperative morbidity (RR 1.16, 95% CI 0.67 to 2.02; 2 studies, 351 participants; very low-certainty evidence), and reoperation rate (RR 0.85, 95% CI 0.52 to 1.41; 2 studies, 351 participants; very low-certainty evidence). Fibrin sealant use may result in little to no difference in the total length of hospital stay (median 16 to 17 days versus 17 days; 2 studies, 351 participants; low-certainty evidence). Serious adverse events were reported in one study (169 participants; low-certainty evidence): more participants developed diabetes mellitus when fibrin sealants were applied to pancreatic duct occlusion, both at three months' follow-up (33.7% fibrin sealant group versus 10.8% control group; 29 participants versus 9 participants) and 12 months' follow-up (33.7% fibrin sealant group versus 14.5% control group; 29 participants versus 12 participants). The studies did not report POPF, quality of life, or cost-effectiveness.

AUTHORS' CONCLUSIONS

Based on the current available evidence, fibrin sealant use may result in little to no difference in the rate of POPF in people undergoing distal pancreatectomy. The evidence is very uncertain about the effect of fibrin sealant use on the rate of POPF in people undergoing pancreaticoduodenectomy. The effect of fibrin sealant use on postoperative mortality is uncertain in people undergoing either distal pancreatectomy or pancreaticoduodenectomy.

Technological advances in fibrin for tissue engineering

Fibrin is a promising natural polymer that is widely used for diverse applications, such as hemostatic glue, carrier for drug and cell delivery, and matrix for tissue engineering. Despite the significant advances in the use of fibrin for bioengineering and biomedical applications, some of its characteristics must be improved for suitability for general use. For example, fibrin hydrogels tend to shrink and degrade quickly after polymerization, particularly when they contain embedded cells. In addition, their poor mechanical properties and batch-to-batch variability affect their handling, long-term stability, standardization, and reliability. One of the most widely used approaches to improve their properties has been modification of the structure and composition of fibrin hydrogels. In this review, recent advances in composite fibrin scaffolds, chemically modified fibrin hydrogels, interpenetrated polymer network (IPN) hydrogels composed of fibrin and other synthetic or natural polymers are critically reviewed, focusing on their use for tissue engineering.

The Impact of Fibrin Sealant Volume on Skin Graft Contraction in a Full-Thickness Skin Graft Model

BACKGROUND

Fibrin sealant has been used for skin grafting in anatomically difficult facial areas. Although biodegradable, an excess of fibrin sealant may inhibit skin graft healing by inhibiting diffusion at the graft-recipient bed interface. The impact of fibrin sealant volume on graft healing was examined in a rat full-thickness skin graft model.

METHODS

Seventy-two full-thickness 2.5 × 2.5-cm skin grafts were used on the dorsum of male Sprague-Dawley rats. The grafts were treated with three different volumes of fibrin sealant placed onto the recipient bed: 0.0 mL or normal saline (group 1), 0.1 mL (group 2), and 0.4 mL (group 3). Graft healing and complications were assessed using digital photographs and necropsies on postoperative days 3, 7, and 21.

RESULTS

Group 3 showed the greatest graft contraction on days 3 and 21, while group 2 showed the least contraction on all 3 postoperative days (P = 0.002, 0.004, and <0.001, respectively). Histopathologic analysis showed inflammatory foreign body reactions in group 3 on days 3 and 7, and less vascular density on day 21 (P = 0.003). Group 1 showed the highest incidence of hematoma (P = 0.004).

CONCLUSION

An excess volume of fibrin sealant may produce pathologic wound contraction in skin grafting because a skin graft lacks a vascular pedicle and is highly dependent on diffusion from the host environment. Before using fibrin sealant for skin grafting in facial areas where the aesthetic outcome is important, the appropriate volume to use can be determined.

Fibrin sealants for the prevention of postoperative pancreatic fistula following pancreatic surgery

BACKGROUND

Postoperative pancreatic fistula is one of the most frequent and potentially life-threatening complications following pancreatic resections. Fibrin sealants have been used in some centers to reduce postoperative pancreatic fistula. However, the use of fibrin sealants during pancreatic surgery is controversial. This is an update of a Cochrane Review last published in 2018.

OBJECTIVES

To assess the safety, effectiveness, and potential adverse effects of fibrin sealants for the prevention of postoperative pancreatic fistula following pancreatic surgery.

SEARCH METHODS

We searched trial registers and the following biomedical databases: the Cochrane Library (2019, Issue 2), MEDLINE (1946 to 13 March2019), Embase (1980 to 11 March 2019), Science Citation Index Expanded (1900 to 13 March 2019), and Chinese Biomedical Literature Database (CBM) (1978 to 13 March 2019).

SELECTION CRITERIA

We included all randomised controlled trials that compared fibrin sealant (fibrin glue or fibrin sealant patch) versus control (no fibrin sealant or placebo) in people undergoing pancreatic surgery.

DATA COLLECTION AND ANALYSIS

Two review authors independently identified the trials for inclusion, collected the data, and assessed the risk of bias. We performed the meta-analyses using Review Manager 5. We calculated the risk ratio (RR) for dichotomous outcomes (or a Peto odds ratio (OR) for very rare outcomes), and the mean difference (MD) for continuous outcomes, with 95% confidence intervals (CIs).

MAIN RESULTS

We included 12 studies involving 1604 participants in the review. Application of fibrin sealants to pancreatic stump closure reinforcement after distal pancreatectomy We included seven studies involving 860 participants: 428 were randomised to the fibrin sealant group and 432 to the control group after distal pancreatectomy. Fibrin sealants may lead to little or no difference in postoperative pancreatic fistula (fibrin sealant 19.3%; control 20.1%; RR 0.96, 95% CI 0.68 to 1.35; 755 participants; four studies; low-quality evidence). Fibrin sealants may also lead to little or no difference in postoperative mortality (0.3% versus 0.5%; Peto OR 0.52, 95% CI 0.05 to 5.03; 804 participants; six studies; low-quality evidence), or overall postoperative morbidity (28.5% versus 23.2%; RR 1.23, 95% CI 0.97 to 1.58; 646 participants; three studies; low-quality evidence). We are uncertain whether fibrin sealants reduce reoperation rate (2.0% versus 3.8%; RR 0.51, 95% CI 0.15 to 1.71; 376 participants; two studies; very low-quality evidence) or length of hospital stay (MD 0.99 days, 95% CI -1.83 to 3.82; 371 participants; two studies; very low-quality evidence). The studies did not report serious adverse events, quality of life, or cost effectiveness. Application of fibrin sealants to pancreatic anastomosis reinforcement after pancreaticoduodenectomy We included four studies involving 393 participants: 186 were randomised to the fibrin sealant group and 207 to the control group after pancreaticoduodenectomy. We are uncertain whether fibrin sealants reduce postoperative pancreatic fistula (16.7% versus 11.7%; RR 1.14, 95% CI 0.28 to 4.69; 199 participants; two studies; very low-quality evidence). We are uncertain whether fibrin sealants reduce postoperative mortality (0.5% versus 2.4%; Peto OR 0.26, 95% CI 0.05 to 1.32; 393 participants; four studies; low-quality evidence) or length of hospital stay (MD 0.01 days, 95% CI -3.91 to 3.94; 323 participants; three studies; very low-quality evidence). There is probably little or no difference in overall postoperative morbidity (52.6% versus 50.3%; RR 1.04, 95% CI 0.87 to 1.24; 323 participants; three studies; moderate-quality evidence) between the groups. We are uncertain whether fibrin sealants reduce reoperation rate (5.2% versus 7.7%; RR 0.74, 95% CI 0.33 to 1.66; 323 participants; three studies, very low-quality evidence). The studies did not report serious adverse events, quality of life, or cost effectiveness. Application of fibrin sealants to pancreatic duct occlusion after pancreaticoduodenectomy We included two studies involving 351 participants: 188 were randomised to the fibrin sealant group and 163 to the control group after pancreaticoduodenectomy. Fibrin sealants may lead to little or no difference in postoperative mortality (8.4% versus 6.1%; Peto OR 1.41, 95% CI 0.63 to 3.13; 351 participants; two studies; low-quality evidence) or length of hospital stay (median 16 to 17 days versus 17 days; 351 participants; two studies; low-quality evidence). We are uncertain whether fibrin sealants reduce overall postoperative morbidity (32.0% versus 27.6%; RR 1.16, 95% CI 0.67 to 2.02; 351 participants; two studies; very low-quality evidence), or reoperation rate (13.6% versus 16.0%; RR 0.85, 95% CI 0.52 to 1.41; 351 participants; two studies; very low-quality evidence). Serious adverse events were reported in one study (169 participants; low-quality evidence): more participants developed diabetes mellitus when fibrin sealants were applied to pancreatic duct occlusion, both at three months' follow-up (33.7% fibrin sealant group versus 10.8% control group; 29 participants versus 9 participants) and 12 months' follow-up (33.7% fibrin sealant group versus 14.5% control group; 29 participants versus 12 participants). The studies did not report postoperative pancreatic fistula, quality of life, or cost effectiveness.

AUTHORS' CONCLUSIONS

Based on the current available evidence, fibrin sealants may have little or no effect on postoperative pancreatic fistula in people undergoing distal pancreatectomy. The effects of fibrin sealants on the prevention of postoperative pancreatic fistula are uncertain in people undergoing pancreaticoduodenectomy.

Fibrin sealants for the prevention of postoperative pancreatic fistula following pancreatic surgery

BACKGROUND

Postoperative pancreatic fistula is one of the most frequent and potentially life-threatening complications following pancreatic resections. Fibrin sealants are introduced to reduce postoperative pancreatic fistula by some surgeons. However, the use of fibrin sealants during pancreatic surgery is controversial. This is an update of a Cochrane Review last published in 2016.

OBJECTIVES

To assess the safety, effectiveness, and potential adverse effects of fibrin sealants for the prevention of postoperative pancreatic fistula following pancreatic surgery.

SEARCH METHODS

We searched trial registers and the following biomedical databases: the Cochrane Library (2018, Issue 4), MEDLINE (1946 to 12 April 2018), Embase (1980 to 12 April 2018), Science Citation Index Expanded (1900 to 12 April 2018), and Chinese Biomedical Literature Database (CBM) (1978 to 12 April 2018).

SELECTION CRITERIA

We included all randomized controlled trials that compared fibrin sealant (fibrin glue or fibrin sealant patch) versus control (no fibrin sealant or placebo) in people undergoing pancreatic surgery.

DATA COLLECTION AND ANALYSIS

Two review authors independently identified the trials for inclusion, collected the data, and assessed the risk of bias. We performed the meta-analyses using Review Manager 5. We calculated the risk ratio (RR) for dichotomous outcomes (or a Peto odds ratio (OR) for very rare outcomes), and the mean difference (MD) for continuous outcomes, with 95% confidence intervals (CIs).

MAIN RESULTS

We included 11 studies involving 1462 participants in the review.Application of fibrin sealants to pancreatic stump closure reinforcement after distal pancreatectomyWe included seven studies involving 860 participants: 428 were randomized to the fibrin sealant group and 432 to the control group after distal pancreatectomy. Fibrin sealants may lead to little or no difference in postoperative pancreatic fistula (fibrin sealant 19.3%; control 20.1%; RR 0.96, 95% CI 0.68 to 1.35; 755 participants; four studies; low-quality evidence). Fibrin sealants may also lead to little or no difference in postoperative mortality (0.3% versus 0.5%; Peto OR 0.52, 95% CI 0.05 to 5.03; 804 participants; six studies; low-quality evidence), or overall postoperative morbidity (28.5% versus 23.2%; RR 1.23, 95% CI 0.97 to 1.58; 646 participants; three studies; low-quality evidence). We are uncertain whether fibrin sealants reduce reoperation rate (2.0% versus 3.8%; RR 0.51, 95% CI 0.15 to 1.71; 376 participants; two studies; very low-quality evidence). There is probably little or no difference in length of hospital stay between the groups (12.1 days versus 11.4 days; MD 0.32 days, 95% CI -1.06 to 1.70; 755 participants; four studies; moderate-quality evidence). The studies did not report serious adverse events, quality of life, or cost effectiveness.Application of fibrin sealants to pancreatic anastomosis reinforcement after pancreaticoduodenectomyWe included three studies involving 251 participants: 115 were randomized to the fibrin sealant group and 136 to the control group after pancreaticoduodenectomy. We are uncertain whether fibrin sealants reduce postoperative pancreatic fistula (1.6% versus 6.2%; RR 0.25, 95% CI 0.01 to 5.06; 57 participants; one study; very low-quality evidence). Fibrin sealants may lead to little or no difference in postoperative mortality (0.1% versus 0.7%; Peto OR 0.15, 95% CI 0.00 to 7.76; 251 participants; three studies; low-quality evidence) or length of hospital stay (12.8 days versus 14.8 days; MD -1.58 days, 95% CI -3.96 to 0.81; 181 participants; two studies; low-quality evidence). We are uncertain whether fibrin sealants reduce overall postoperative morbidity (33.7% versus 34.7%; RR 0.97, 95% CI 0.65 to 1.45; 181 participants; two studies; very low-quality evidence), or reoperation rate (7.6% versus 9.2%; RR 0.83, 95% CI 0.33 to 2.11; 181 participants; two studies, very low-quality evidence). The studies did not report serious adverse events, quality of life, or cost effectiveness.Application of fibrin sealants to pancreatic duct occlusion after pancreaticoduodenectomyWe included two studies involving 351 participants: 188 were randomized to the fibrin sealant group and 163 to the control group after pancreaticoduodenectomy. Fibrin sealants may lead to little or no difference in postoperative mortality (8.4% versus 6.1%; Peto OR 1.41, 95% CI 0.63 to 3.13; 351 participants; two studies; low-quality evidence) or length of hospital stay (17.0 days versus 16.5 days; MD 0.58 days, 95% CI -5.74 to 6.89; 351 participants; two studies; low-quality evidence). We are uncertain whether fibrin sealants reduce overall postoperative morbidity (32.0% versus 27.6%; RR 1.16, 95% CI 0.67 to 2.02; 351 participants; two studies; very low-quality evidence), or reoperation rate (13.6% versus 16.0%; RR 0.85, 95% CI 0.52 to 1.41; 351 participants; two studies; very low-quality evidence). Serious adverse events were reported in one study: more participants developed diabetes mellitus when fibrin sealants were applied to pancreatic duct occlusion, both at three months' follow-up (33.7% fibrin sealant group versus 10.8% control group; 29 participants versus 9 participants) and 12 months' follow-up (33.7% fibrin sealant group versus 14.5% control group; 29 participants versus 12 participants). The studies did not report postoperative pancreatic fistula, quality of life, or cost effectiveness.

AUTHORS' CONCLUSIONS

Based on the current available evidence, fibrin sealants may have little or no effect on postoperative pancreatic fistula in people undergoing distal pancreatectomy. The effects of fibrin sealants on the prevention of postoperative pancreatic fistula are uncertain in people undergoing pancreaticoduodenectomy.

Novel hemostatic agents based on gelatin-microbial transglutaminase mix

Hemostasis is a major challenge in surgical procedures and traumas. Conventional hemostatic methods have limited efficacy and may cause additional tissue damage. In this study, we designed a novel hemostatic agent based on the in situ gel formation of gelatin cross-linked by a novel microbial transglutaminase (mTGase), in which the amino acid sequences differed from commercial mTGases. The new hemostatic agent showed the same biochemical crosslinking chemistry as the final stages of the blood coagulation cascade while using gelatin as a "structural" protein (rather than fibrin) and a calcium-independent mTGase as the crosslinking catalyst (rather than factor XIIIa). In rat liver hemostasis models, the hemostatic agent not only showed a similar hemostatic effect as that of SURGIFLO^® (positive control), but also stronger adhesion strength and elasticity than SURGIFLO^®. Therefore, this biomimetic gelatin-mTGase mix hemostatic is a novel and effective surgical sealant.

Tissue-Engineered Vocal Fold Mucosa Implantation in Rabbits

OBJECTIVE

To assess phonatory function and wound healing of a tissue-engineered vocal fold mucosa (TE-VFM) in rabbits. An "artificial" vocal fold would be valuable for reconstructing refractory scars and resection defects, particularly one that uses readily available autologous cells and scaffold. This work implants a candidate TE-VFM after resecting native epithelium and lamina propria in rabbits.

STUDY DESIGN

Prospective animal study.

SETTING

Research laboratory.

SUBJECTS AND METHODS

Rabbit adipose-derived stem cells were isolated and cultured in three-dimensional fibrin scaffolds to form TE-VFM. Eight rabbits underwent laryngofissure, unilateral European Laryngologic Society type 2 cordectomy, and immediate reconstruction with TE-VFM. After 4 weeks, larynges were excised, phonated, and examined by histology.

RESULTS

Uniform TE-VFM implants were created, with rabbit mesenchymal cells populated throughout fibrin hydrogels. Rabbits recovered uneventfully after implantation. Phonation was achieved in all, with mucosal waves evident at the implant site. Histology after 4 weeks showed resorbed fibrin matrix, continuous epithelium, and mildly increased collagen relative to contralateral unoperated vocal folds. Elastic fiber appearance was highly variable. Inflammatory cell infiltrate was limited to animals receiving sex-mismatched implants.

CONCLUSION

TE-VFMs were successfully implanted into 8 rabbits, with minor evidence of scar formation and immune reaction. Vibration was preserved 4 weeks after resecting and reconstructing the complete vocal fold cover layer. Further studies will investigate the mechanism and durability of improvement. TE-VFM with autologous cells is a promising new approach for vocal fold reconstruction.

Fibrin sealants for the prevention of postoperative pancreatic fistula following pancreatic surgery

BACKGROUND

Postoperative pancreatic fistula is one of the most frequent and potentially life-threatening complications following pancreatic resections. Fibrin sealants are introduced to reduce postoperative pancreatic fistula by some surgeons. However, the use of fibrin sealants during pancreatic surgery is controversial.

OBJECTIVES

To assess the safety, effectiveness, and potential adverse effects of fibrin sealants for the prevention of postoperative pancreatic fistula following pancreatic surgery.

SEARCH METHODS

We searched The Cochrane Library (2015, Issue 7), MEDLINE (1946 to 26 August 2015), EMBASE (1980 to 26 August 2015), Science Citation Index Expanded (1900 to 26 August 2015), and Chinese Biomedical Literature Database (CBM) (1978 to 26 August 2015).

SELECTION CRITERIA

We included all randomized controlled trials that compared fibrin sealant group (fibrin glue or fibrin sealant patch) versus control group (no fibrin sealant or placebo) in people undergoing pancreatic surgery.

DATA COLLECTION AND ANALYSIS

Two review authors independently identified the trials for inclusion, collected the data, and assessed the risk of bias. We performed the meta-analyses using Review Manager 5. We calculated the risk ratio (RR) for dichotomous outcomes (or a Peto odds ratio for very rare outcomes), and the mean difference (MD) for continuous outcomes with 95% confidence intervals (CI).

MAIN RESULTS

We included nine trials involving 1095 participants who were randomized to the fibrin sealant group (N = 550) and the control group (N = 545) after pancreatic surgery. All of the trials were at high risk of bias. There was no evidence of differences in overall postoperative pancreatic fistula (fibrin sealant 29.6%; control 31.0%; RR 0.93, 95% CI 0.71 to 1.21; P = 0.58; nine studies; low-quality evidence), postoperative mortality (3.1% versus 2.1%; Peto OR 1.29, 95% CI 0.59 to 2.82; P = 0.53; eight studies; very low-quality evidence), overall postoperative morbidity (29.6% versus 28.9%; RR 1.04, 95% CI 0.82 to 1.32; P = 0.77; five studies), reoperation rate (8.7% versus 10.7%; RR 0.80, 95% CI 0.53 to 1.21; P = 0.29; five studies), or length of hospital stay (12.9 days versus 13.1 days; MD -0.73 days, 95% CI -2.20 to 0.74; P = 0.331; six studies) between the groups. The proportion of postoperative pancreatic fistula that was clinically significant was not mentioned in most trials. On inclusion of trials that clearly distinguished clinically significant fistulas, there was inadequate evidence to establish the effect of fibrin sealants on clinically significant postoperative pancreatic fistula (9.4% versus 13.4%; RR 0.72, 95% CI 0.42 to 1.21; P = 0.21; three studies). Quality of life and cost effectiveness were not reported in any of the trials.

AUTHORS' CONCLUSIONS

Based on the current available evidence, fibrin sealants do not seem to prevent postoperative pancreatic fistula in people undergoing pancreatic surgery.

Limbal Stem Cell Deficiency: Current Treatment Options and Emerging Therapies

Severe ocular surface disease can result in limbal stem cell deficiency (LSCD), a condition leading to decreased visual acuity, photophobia, and ocular pain. To restore the ocular surface in advanced stem cell deficient corneas, an autologous or allogenic limbal stem cell transplantation is performed. In recent years, the risk of secondary LSCD due to removal of large limbal grafts has been significantly reduced by the optimization of cultivated limbal epithelial transplantation (CLET). Despite the great successes of CLET, there still is room for improvement as overall success rate is 70% and visual acuity often remains suboptimal after successful transplantation. Simple limbal epithelial transplantation reports higher success rates but has not been performed in as many patients yet. This review focuses on limbal epithelial stem cells and the pathophysiology of LSCD. State-of-the-art therapeutic management of LSCD is described, and new and evolving techniques in ocular surface regeneration are being discussed, in particular, advantages and disadvantages of alternative cell scaffolds and cell sources for cell based ocular surface reconstruction.

3D tissue-engineered bone marrow as a novel model to study pathophysiology and drug resistance in multiple myeloma

PURPOSE

Multiple myeloma (MM) is the second most prevalent hematological malignancy and it remains incurable despite the introduction of several novel drugs. The discrepancy between preclinical and clinical outcomes can be attributed to the failure of classic two-dimensional (2D) culture models to accurately recapitulate the complex biology of MM and drug responses observed in patients.

EXPERIMENTAL DESIGN

We developed 3D tissue engineered bone marrow (3DTEBM) cultures derived from the BM supernatant of MM patients to incorporate different BM components including MM cells, stromal cells, and endothelial cells. Distribution and growth were analyzed by confocal imaging, and cell proliferation of cell lines and primary MM cells was tested by flow cytometry. Oxygen and drug gradients were evaluated by immunohistochemistry and flow cytometry, and drug resistance was studied by flow cytometry.

RESULTS

3DTEBM cultures allowed proliferation of MM cells, recapitulated their interaction with the microenvironment, recreated 3D aspects observed in the bone marrow niche (such as oxygen and drug gradients), and induced drug resistance in MM cells more than 2D or commercial 3D tissue culture systems.

CONCLUSIONS

3DTEBM cultures not only provide a better model for investigating the pathophysiology of MM, but also serve as a tool for drug development and screening in MM. In the future, we will use the 3DTEBM cultures for developing personalized therapeutic strategies for individual MM patients.

Effect of aerosolized fibrin sealant on hemostasis and wound healing after endoscopic sinus surgery: a prospective randomized study

BACKGROUND

The purpose of this study was to investigate the effect of aerosolized fibrin sealant (FS) compared with that of polyvinyl acetal sponge packing on hemostasis and wound healing after functional endoscopic sinus surgery (FESS).

METHODS

We conducted a prospective randomized controlled trial of the use of aerosolized FS in 41 consecutive patients who underwent bilateral FESS between February 2011 and March 2012. The patients were randomized to receive FS applied via an aerosol spray in one nasal cavity and polyvinyl acetal sponge packing in the opposite cavity. The patients were followed up at 1, 2, 4, 8, and 12 weeks postoperatively. Crusting, adhesion, bleeding, granulation tissue formation, infection, and frontal sinus ostium stenosis after endoscopic surgery were assessed using a grading scale. Subjective symptoms related to nasal packing were evaluated using questionnaires quantified by visual analog scales.

RESULTS

The degree of granulation and crusting was significantly reduced in the side treated with FS compared with the polyvinyl acetal sponge side, as were bleeding and pain during nasal packing removal (p < 0.05). In addition, general satisfaction and willingness to reuse the material were significantly higher for the FS-treated side than for the polyvinyl acetal sponge-packed side (p < 0.001).

CONCLUSIONS

Compared with polyvinyl acetal sponge, aerosolized FS shows beneficial effects on hemostasis and wound healing after FESS. The application of FS resulted in a high degree of patient satisfaction without additional morbidity.

Use of Tissue-Glue–Coated Collagen Sponge (TachoSil) to Repair Minor Cerebral Dural Venous Sinus Lacerations

BACKGROUND

Significant hemorrhage may occur from the cerebral venous sinuses during the dural separation from the bone flap, particularly in elderly patients. It is important to achieve an urgent hemostatic control.

OBJECTIVE

To evaluate the efficacy and safety of a new fixed combination tissue sealant (TachoSil) in patients with bleeding from lacerations of cerebral venous sinuses.

METHODS

Between September 2012 and June 2014, 57 patients (39 female, 18 male) presenting with iatrogenic tears of the superior sagittal or transverse/sigmoid sinuses were treated with a topical fibrin sealant patch. Intraoperative source of bleeding, time to bleeding control, quantity of sealant sponge used, and postoperative complications were evaluated. Time to hemostasis was used as the primary end point.

RESULTS

Effective hemostasis, defined as cessation of bleeding after application of topical hemostatic agent, was achieved no later than 4 minutes in all except 5 patients with persistent bleeding from the sinus. In these 5 cases, bleeding was finally stopped after application of a new larger layer of TachoSil Sponge (2 cases) or gelatin hemostatic matrix (2 cases) or fibrin glue (1 case) over the layer of TachoSil.

CONCLUSION

We report our experience with a new hemostasis technique to manage bleeding from iatrogenic lacerations of cerebral venous sinuses.

Reduction of postoperative haemorrhage with the use of a haemostatic thrombin matrix in patients who underwent decortication

OBJECTIVE

To assess the efficacy of two measures for the control of postoperative haemorrhage in patients with fibrothoracic disease secondary to symptomatic extraparenchymal restrictive disease (e.g.empyema, haematoma) undergoing decortication.

METHODS

This randomized, prospective study was performed in 50 adult patients with fibrothoracic disease secondary to symptomatic extraparenchymal restrictive disease who were scheduled to undergo decortication. Patients were randomized to receive either electrocautery plus hot compressor application or a thrombin-added haemostatic matrix (THM) for intraoperative haemostasis (n=25 per group). Control of postoperative haemorrhage was compared between groups by evaluation of pre- and postoperative blood characteristics and mean postoperative drainage volume and blood transfusion requirements.

RESULTS

Mean postoperative drainage and blood transfusion volumes were significantly lower in the THM group versus the electrocautery plus hot compress group. There was no difference in preoperative and postoperative blood tests in the THM group, whereas significant differences were observed in the electrocautery plus hot compress group. There were no infections, systemic allergies or sensitization, or reoperations in either group.

CONCLUSIONS

Compared with electro cautery plus hot compress, the use of a THM significantly reduced postoperative haemorrhage and blood transfusion requirements in patients who underwent decortication.

Fibrin glue in ophthalmology

Suturing is a time consuming task in ophthalmology and suture induced irritation and redness are frequent problems. Postoperative wound infection and corneal graft rejection are examples of possible suture related complications. To prevent these complications, ophthalmic surgeons are switching to sutureless surgery. A number of recent developments have established tissue adhesives like cyanoacrylate glue and fibrin glue as attractive alternatives to sutures. A possible and promising new application for tissue adhesives is to provide a platform for tissue engineering. Currently, tissue glue is being used for conjunctival closure following pterygium and strabismus surgery, forniceal reconstruction surgery, amniotic membrane transplantation, lamellar corneal grafting, closure of corneal perforations and descematoceles, management of conjunctival wound leaks after trabeculectomy, lid surgery, adnexal surgery and as a hemostat to minimise bleeding. The purpose of this review is to discuss the currently available information on fibrin glue.

A gelatin-thrombin matrix for hemostasis after endoscopic sinus surgery

PURPOSE

Adequate hemostasis is necessary after endoscopic sinus surgery. This study evaluated the clinical performance of Surgiflo hemostatic matrix (Johnson&Johnson Wound Management, a division of Ethicon Inc, Somerville, NJ) with Thrombin-JMI (distributed by Jones Pharma Inc, Bristol, VA, a wholly owned subsidiary of King Pharmaceuticals, Bristol, TN) in achieving hemostasis in patients undergoing endoscopic sinus surgery. Surgiflo hemostatic matrix is a sterile, absorbable porcine gelatin intended to aid with hemostasis when applied to a bleeding surface.

MATERIALS AND METHODS

This multicenter, prospective, single-arm study evaluated the success in achieving hemostasis within 10 minutes of product application in patients undergoing elective primary or revision endoscopic sinus surgery for chronic sinusitis with a bleeding surface requiring hemostasis. Patient satisfaction and postoperative healing were also evaluated.

RESULTS

Thirty patients were enrolled, including 17 males and 13 females (average age, 48.2 +/- 15.1 years), with 54 operated sides. Twenty-nine patients achieved hemostasis within 10 minutes of product application (96.7% success rate; 1-sided 95% confidence interval, 85.1%-100%). The median total time to hemostasis including manual compression was 61 seconds. No complications, such as synechiae, adhesion, or infection, were reported.

CONCLUSIONS

Surgiflo hemostatic matrix with Thrombin-JMI was clinically effective in controlling bleeding in 96.7% of patients. Further randomized controlled trials are indicated.

Viscoelastic adhesive mechanics of aldehyde-mediated soft tissue sealants

Soft tissue sealants generally sacrifice adhesive strength for biocompatibility, motivating the development of materials which interact with tissue to a predictable and controllable extent. Crosslinked hydrogels comprising aminated star polyethylene glycol and high molecular weight dextran aldehyde polymers (PEG:dextran) display aldehyde-mediated adhesion and readily tunable reactivity with soft tissue ex-vivo. Evaluation of PEG:dextran compositional variants revealed that the burst pressure of repaired intestinal wounds and the extent of material-induced tissue deformation both increase nonlinearly with formulation aldehyde content and are consistently within the desired range established by traditional sealants. Adhesive test elements featuring PEG:dextran and intestinal tissue exhibited considerable viscoelasticity, prompting use of a standard linear solid (SLS) model to describe adhesive mechanics. Model elements were accurately represented as continuous functions of PEG:dextran chemistry, facilitating prediction of adhesive mechanics across the examined range of compositional formulations. SLS models of traditional sealants were also constructed to allow general correlative analyses between viscoelastic adhesive mechanics and metrics of sealant performance. Linear correlation of equilibrium SLS stiffness to sealant-induced tissue deformation indicates that dense adhesive crosslinking restricts tissue expansion, while correlation of instantaneous SLS stiffness to burst pressure suggests that the adhesive stress relaxation capacity of PEG:dextran enhances their overall performance relative to traditional sealants.

Tissue adhesives and the pancreas: biocompatibility and adhesive properties of 6 preparations

OBJECTIVES

The aim of this study was to investigate biocompatibility and adhesive properties of 6 tissue adhesives available, when applied between the pancreas and jejunum in an experimental model.

METHODS

Portion of jejunum was glued on the pancreas in rats with 3 cyanoacrylate derivatives (Histoacryl, Dermabond, and Glubran 2), 2 human fibrin sealants (Tisseel Duo Quick and Quixil), and 1 albuminglutaraldehyde sealant (BioGlue). Pancreatic tissue specimens and blood samples were harvested 1, 3, 7, and 21 days after gluing for histological determination and amylase activity measurement. Pancreaticojejunal attachment created with adhesives underwent tensile strength measurement at each time point. Samples were also taken from unoperated rats and sham-operated rats.

RESULTS

Exposure and sham groups both induced a similar increase in amylase activity on day 1 with normalization by day 3. Sham operation induced mild changes in the pancreas. Each tissue adhesive induced changes in pancreatic histology to the entire gland. Injurious effect was more severe with the 3 cyanoacrylates than with the 3 fibrin/semisynthetic glues. Histoacryl and Quixil induced lower tensile strength than the other adhesives.

CONCLUSIONS

All of the tissue adhesives studied induced histological changes in the pancreas of which at least part might be considered harmful. The potentially harmful tissue effects of the preparations tested might compromise the use of these substances in pancreatic surgery.

Application of fibrin sealant at the urethrovesical anastomosis in robotic assisted radical prostatectomy: does it enable earlier Foley catheter and Jackson-Pratt drain removal?

Leakage at the urethrovesical anastomosis in the post-operative period can result in morbidity including ileus. We examined the effectiveness of using a fibrin sealant at the anastomosis to limit urine leakage thereby facilitating earlier Jackson–Pratt drain and Foley catheter removal following robotic assisted laparoscopic prostatectomy (RALRP). Forty consecutive patients underwent RALRP by one surgeon at our institution. The first 20 patients underwent standard operation and served as the control group. The subsequent 20 patients underwent the same operation with addition of fibrin sealant following a running absorbable sutured urethrovesical anastomosis. The two groups were compared for age (60.5 vs. 58.2 years), pre-operative PSA (5.23 vs. 4.71), Gleason score (6.3 vs. 6.5), stage at resection, and prostate size at resection (51.7 vs. 47.7 g). Wilcoxon rank sum test determined no statistically significant differences in the groups. Patients in the fibrin sealant group had 1.3 versus 2.1 days with a Jackson–Pratt drain, 9.75 versus 12.1 days with a catheter, and an average of 38.6 versus 63.2 cc of drainage per shift. Catheters were removed when a cystogram demonstrated no extravasation of contrast. Two patients in the control group and no patients in the fibrin sealant group had large-volume leakage and ileus post-operatively. In patients undergoing RALRP, application of fibrin sealant at the urethrovesical anastomosis appears to facilitate sealing, thereby allowing earlier removal of the JP drain, by 0.8 days, and the Foley catheter, by 2.35 days, than in controls. No patients in the fibrin sealant group suffered post-operative ileus. This adjunct may be especially useful early in the learning process to reduce morbidity.

Influence of calcium chloride and aprotinin in the in vivo biological performance of a composite combining biphasic calcium phosphate granules and fibrin sealant

Highly bioactive biomaterials have been developed to replace bone grafts in orthopedic revision and maxillofacial surgery for bone augmentation. A mouldable, self-hardening material can be obtained by combining TricOs Biphasic Calcium Phosphate Granules and Tissucol Fibrin Sealant. Two components, calcium chloride and antifibrinolytic agents (aprotinin), are essential for the stability of the fibrin clot. The ingrowth of cells in composites combining sealants without calcium chloride or with a low concentration of aprotinin was evaluated in vivo in an experiment on rabbits. Bone colonization was compared using TricOs alone or with the composite made from TricOs and the standard fibrin sealant. Without the addition of calcium chloride, the calcium ions released by the ceramic component interacted with the components of the sealant too late to stabilize the clot. With a low concentration of aprotinin, the degradation of the clot occurred more quickly, leading to the absence of a scaffold on which the bone cells could colonize the composite. Our results indicate that a stable fibrin scaffold is crucial for bone colonization. The low calcium chloride and low aprotinin groups have shown lower bone growth. Further studies will be necessary to determine the minimal amount of antifibrinolytic agent (aprotinin) necessary to allow the same level of osteogenic activity as the TricOs-fibrin glue composite.

Emerging new drugs for wound repair

Every year, millions of people experience burns, suffer from nonhealing wounds, or have acute wounds that become complicated by infection, dehiscence or problematic scarring. Effective wound treatment requires carefully considered interventions often requiring multiple clinic or hospital visits. The resulting costs of wound care are staggering, and more efficacious and cost-effective therapies are needed to decrease this burden. Unfortunately, the expenses and difficulties encountered in performing clinical trials have led to a relatively slow growth of new treatment options for the wound management. Research efforts attempting to examine wound pathophysiology have been hampered by the lack of an adequate chronic wound healing model, and the complexity of the wound healing cascade has limited attempts at pharmacological modification. As such, currently available wound healing therapies are only partially effective. Therefore, many new therapies are emerging that target various aspects of wound repair and the promise of new therapeutic interventions is on the immediate horizon.

Histological assessment of titanium and polypropylene fiber mesh implantation with and without fibrin tissue glue

Polypropylene (PP) and titanium (Ti) meshes are well-known surgical implants that provoke a relative low foreign body reaction. Firm stabilization of the implant is important to prevent migration and subsequent failure of the operation. Fibrin tissue glues are commercially available adhesives and are widely accepted and applied in the medical field for hemorrhage, surgical bleeding, support of wound healing, wound and tissue gluing, sealing, and closure but also as antiadhesive agent in certain applications. The objective of this study was to evaluate the additional histological effect of fibrin glue application combined with two different types of meshes. Six pieces of mesh of each were subcutaneously implanted for 3, 6, and 12 weeks, with and without fibrin glue. After excision, processing, and staining, light microscopic analysis was performed on the sections, using subjective histological description and histomorphometry. Capsule quality, capsule thickness, interstitial quality, and total score were evaluated. To compare the samples with glue and without glue, analysis of variance (ANOVA) tests were carried out. No complications were observed. In general, the glue remnants remained visible at 3 and 6 weeks of implantation, accompanied by an inflammatory reaction and macrophage activity. At 12 weeks, all samples showed good tissue integration without evidence of glue. Evidently, the samples with glue demonstrated a prolonged inflammatory response and were surrounded by fibrous tissue capsules that were significantly thicker compared with the samples without glue (p < 0.05).

Fibrin glue in the management of corneal melt

Human fibrin glue aids physiological healing thereby reducing corneal vascularization and scarring compared with cyanoacrylate tissue adhesive. A 40-year-old intellectually disabled man with a corneal melt is reported who was managed successfully using human fibrin glue, alleviating the need for emergency penetrating keratoplasty.

Effects of Tisseel Fibrin Glue on the Central Nervous System of Nonhuman Primates

For many years, neurosurgeons and otolaryngologic surgeons have used the fibrin glue product Tisseel to repair skull-base spinal fluid leaks and to help secure repairs following anterior cranial-base surgery. Despite the widespread use, the potential focal cerebral toxicity of this fibrin glue has never been investigated. We studied the safety of Tisseel applied directly to neural tissue (brain parenchyma, cervical cord, and C3-C6 spinal roots) of 6 monkeys (Macaca nemestrina) to determine if any underlying biochemical injury would occur. Another 3 animals that served as controls received saline rather than Tisseel. We found that median nerve electroencephalographic tracings and somatosensory evoked potentials in the experimental and control animals were identical. Likewise, cerebrospinal fluid indicators of neuronal or brain injury, inflammatory responses, and infection were negative in both groups. Finally, there were no significant differences between the two groups with respect to edema volumes and apparent diffusion coefficient values. We conclude that Tisseel does not induce an apparent inflammatory response or abnormal neurophysiologic or histologic response within 5 days of its application when it is applied directly to the brain parenchyma or onto the cervical spinal cord.

The effects of tissue sealants, platelet gels, and growth factors on wound healing

The improved understanding of wound healing has resulted in the rapid expansion of tissue adhesives, platelet gels, and the use of growth factors. Tissue sealants have been used to close incisions, seal and secure skin flaps, as well as promote hemostasis. Platelet gels have multiple uses that take advantage of their inherent clot-forming ability as well as their potential to release growth factors. Recombinant platelet-derived growth factor has been studied extensively for the treatment of chronic dermal ulcers and shows promise in enhancing wound care. This article will address some recent advancements related to the expanding use of tissue sealants and growth factors to enhance wound healing within the head and neck area.

Elastic cartilage engineering using novel scaffold architectures in combination with a biomimetic cell carrier

Tissue engineering of an elastic cartilage graft that meets the criterion for both structural and functional integration into host tissue, as well as allowing for a clinically tolerable immune response, is a challenging endeavour. Conventional scaffold technologies have limitations in their ability to design and fabricate complex-shaped matrix architectures of structural and mechanical equivalence to elastic cartilage found in the body. We attempted to investigate the potential of conventionally isolated and passaged chondrocytes (2D environment) when seeded and cultured in combination with a biomimetic hydrogel in a mechanically stable and biomimetic composite matrix to form elastic cartilage within ectopic implantation sites. In vitro cultured scaffold/hydrogel/chondrocytes constructs showed islets of cartilage and mineralized tissue formation within the cell-seeded specimens in both pig and rabbit models. Specimens with no cells seeded showed only vascularized fibrous tissue ingrowth. These studies demonstrated the potential of such scaffold/hydrogel/cell constructs to support chondrogenesis in vivo. However, it also showed that even mechanically stable scaffolds do not allow regeneration of a large mass of structural and functional cartilage within a matrix architecture seeded with 2D passaged chondrocytes in combination with a cell biomimetic carrier. Hence, future experiments will be designed to evaluate an initial 3D culture of chondrocytes, effect on cell phenotype and their subsequent culture within biomimetic 3D scaffold/cell constructs.