Late Complications of Gelatin-Resorcin-Formalin Glue in the Repair of Acute Type A Aortic Dissection

The non to moderately dilated root in acute type A aortic dissection: outcomes of the PENN-BERN registry in young, non-syndromic patients

OBJECTIVES

There is an ongoing debate regarding whether patients benefit more from root replacement compared to a reconstruction of the sinuses of Valsalva in acute type A aortic dissection (aTAAD). In those with known or suspected connective tissue disorders, root replacement is considered appropriate. However, there are currently no diameter-based guidelines regarding the best approach in patients with minimally to moderately dilated root and no connective tissue disorders.

METHODS

From January 2005 to December 2022, a two-centre registry of aTAAD was created. Patients were included based on their age (≤60 years), the absence of root entry and dilatation >50 mm and the absence of syndromic hereditable aortic disease. Patients were divided into 2 groups based on the proximal procedure, root reconstruction and root replacement. Propensity score pair matching was performed based on preoperative characteristics.

RESULTS

Cumulative incidence of reintervention at 10 years was slightly higher after root reconstruction 13% vs 3.9% in the matched group (P = 0.040). Survival at 10 years was not affected by the procedure independently of the matching 72.1% vs 71.4% (P = 0.2). Uni- and multivariate Cox regressions showed that a root diameter of >40 mm was associated with a hazard ratio of 7.7 (95% confidence interval 2.6-23) and 5.4 (7-17), respectively, for reoperation for aneurysm and pseudoaneurysm.

CONCLUSIONS

Rate of reoperation due to proximal pseudoaneurysm and aneurysm could be significantly reduced with a lower threshold of 40 mm to replace the aortic root in aTAAD than in elective cases.

Hemolytic Anemia Occurring 14 Years after Ascending Aortic Replacement for Acute Type A Aortic Dissection Due to Aortic Pseudoaneurysm Derived from Anastomotic Leakage: A Case Report

A 64-year-old male patient who presented with symptoms indicative of hemolytic anemia was referred to our hospital. After obtaining the patient's history, it was found that hemolysis occurred 14 years after he underwent ascending aortic replacement for acute type A aortic dissection. Enhanced computed tomography revealed an aortic pseudoaneurysm at the proximal anastomosis, which was thought to be the cause of hemolysis. Furthermore, aortic valve regurgitation and dilatation of the sinus of Valsalva were also found on a transthoracic echocardiogram. Therefore, the Bentall procedure was performed. During the surgery, aortic pseudoaneurysm formation and vascular graft stenosis were observed. The postoperative course was uneventful, and hemolysis diminished soon after the surgery.

Aortic root repair in acute type A aortic dissection: Neomedia or no neomedia

OBJECTIVE

Neomedia has been frequently used for aortic root repair in acute type A aortic dissection. We aimed to determine the efficacy and necessity of neomedia during acute type A aortic dissection root repair.

METHODS

From January 2010 to February 2021, 308 patients with acute type A aortic dissection underwent aortic root repair with neomedia (n = 132) or without neomedia (n = 176). Of these, 121 matched pairs were identified using propensity score matching based on age, sex, coronary artery disease, preoperative renal failure, acute stroke, prior cardiac surgery, cardiogenic shock, coronary malperfusion, preoperative cardiopulmonary resuscitation, and severe aortic insufficiency.

RESULTS

After matching, the preoperative demographics and comorbidities were well balanced in both groups. Compared with the neomedia group, the no neomedia group had less hemiarch (57% vs 69%, P = .05) and more zone 1 arch replacements (12% vs 4.1%, P = .03), shorter hypothermic circulatory arrest time (28 vs 36 minutes, P < .001), and shorter crossclamp time (120 vs 131 minutes, P = .02). Postoperative outcomes were similar, and the odds ratio by univariable logistic model of no neomedia for operative mortality was 0.83 (P = .76). Aortic root growth over 11 years (0.11 vs 0.16 mm/year, P = .66), 5-year freedom from greater than mild aortic insufficiency (84% vs 85%, P = .80), reoperation for root pathology (1 patient in each group), and 8-year survival (80% [95% confidence interval, 69-97] vs 71% [95% confidence interval, 55-82], P = .26) were similar between the neomedia and no neomedia groups.

CONCLUSIONS

In patients with acute type A aortic dissection, aortic root repair with or without neomedia was equally safe and effective. Neomedia use could be avoided in acute type A aortic dissection repair.

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.

Short-term outcomes of a simple and effective approach to aortic root and arch repair in acute type A aortic dissection

OBJECTIVE

To evaluate short-term outcomes following direct aortic root and arch repair in patients with acute type A aortic dissection (ATAAD) without technical adjuncts.

METHODS

Between 2012 and 2016, 94 consecutive patients with ATAAD underwent surgical repair, including aortic root repair (n = 45), root replacement (n = 39), or no root procedure (n = 10). Aortic root repair was achieved by running approximation of the dissected aortic wall circumferentially at the sinotubular junction and reinforcing the coronary ostia with 5-0 Prolene. The aortic root and arch were anastomosed to the Dacron graft with 5-0 Prolene without Teflon felt or biological glue.

RESULTS

Postoperative new-onset myocardial infarction, stroke, renal failure, and complete heart block occurred in 0%, 4%, 13%, and 0% of patients, respectively, whereas 30-day mortality was 4%. The incidences of permanent neurologic deficit and renal failure were 1% and 2%, respectively. Up to 5 years, the aortic root repair group was free from residual or recurrent aortic root dissection, major change in the aortic root diameter, and moderate to severe aortic regurgitation; the entire cohort was free of anastomotic pseudoaneurysm and reoperation for proximal aortic pathology or significant change in diameter of the aortic arch and descending thoracic aorta. Overall survival was 85% at 4 years and was significantly enhanced in the aortic root repair group compared with the Bentall group (n = 24) (93% vs 57%; P = .035).

CONCLUSIONS

Direct aortic root and arch repair with approximation of the aortic wall without use of technical adjuncts is safe and effective for patients with ATAAD. If warranted, preservation of the native aortic valve should be considered for a potential survival benefit.

Limited root repair in acute type A aortic dissection is safe but results in increased risk of reoperation

OBJECTIVE

Management of the aortic root is a challenge for surgeons treating acute type A aortic dissection.

METHODS

We performed a retrospective review of the acute type A aortic dissection experience at Stanford Hospital between 2005 and 2015 and identified patients who underwent either limited root repair or aortic root replacement. Differences in baseline characteristics were balanced with inverse probability weighting to estimate the average treatment effect on the controls. Weighted logistic regression was used to evaluate in-hospital mortality. Weighted Cox proportional hazards regression was used to evaluate differences in the hazard for mid-term death. Reoperation was evaluated with death as a competing risk with the Fine-Gray subdistribution hazard.

RESULTS

After we excluded patients managed either nonoperatively or with definitive endovascular repair, there were 293 patients without connective tissue disease who underwent either limited root repair or aortic root replacement. There was no difference in weighted perioperative mortality, odds ratio 0.89 (95% confidence interval [CI], 0.44-1.76, P = .7), and there was no difference in weighted survival, hazard ratio 1.12 (95% CI, 0.54-2.31, P = .8). Risk of reoperation was greater in limited root repair (11.8%, 95% CI, 0.0%-23.8%) than for root replacement (0%), P < .001.

CONCLUSIONS

Limited root repair was associated with increased risk of late reoperation after repair of acute type A aortic dissection. Surgeons with adequate experience may consider aortic root replacement in well-selected patients. However, given good outcomes after limited root repair, surgeons should not feel compelled to perform this more-complex operation.

Evolution of surgical therapy for Stanford acute type A aortic dissection

Acute type A aortic dissection (AcA-AoD) is a surgical emergency associated with very high morbidity and mortality. Unfortunately, the early outcome of emergency surgical repair has not improved substantially over the last 20 years. Many of the same debates occur repeatedly regarding operative extent and optimal conduct of the operation. The question remains: are patients suffering from too large an operation or too small? The pendulum favoring routine aortic valve resuspension, when feasible, has swung towards frequent aortic root replacement. This already aggressive approach is now being challenged with the even more extensive valve-sparing aortic root replacement (V-SARR) in selected patients. Distally, open replacement of most of the transverse arch is best in most patients. The need for late aortic re-intervention has not been shown to be affected by more extensive distal operative procedures, but the contemporary enthusiasm for a distal frozen elephant trunk (FET) only seems to build. It must be remembered that the first and foremost goal of the operation is to have an operative survivor; additional measures to reduce late morbidity are secondary aspirations. With increasing experience, true contraindications to emergency surgical operation have dwindled, but patients with advanced age, multiple comorbidities, and major neurological deficits do not fare well. The endovascular revolution, moreover, has spawned innovative options for modern practice, including ascending stent graft and adaptations of the old flap fenestration technique. Despite the increasingly complex operations and ever expanding therapies, this life-threatening disease remains a stubborn challenge for all cardiovascular surgeons. Development of specialized thoracic aortic teams and regionalization of care for patients with AcA-AoD offers the most promise to improve overall results.

When and how to replace the aortic root in type A aortic dissection

Management of aortic root pathology during repair of acute type A aortic dissection (TAAD) requires a comprehensive evaluation of the patient's anatomy, demographics, comorbidities and physiologic status at the time of emergent operative intervention. Surgical options include conservative repair of the root (CRR) (with or without replacement of the aortic valve), replacement of the native valve and aortic root using a composite valve-conduit and valve sparing root replacement (VSRR). The primary objective of this review is to provide data for surgeons to aid in their decision-making process regarding management of the aortic root during repair of TAAD. No time or language restrictions were imposed and references of the selected studies were checked for additional relevant citations. Multiple retrospective reviews have demonstrated equivalent operative mortality between aortic root repair and replacement during TAAD. There is a higher incidence of aortic root reintervention with aortic root repair compared to aortic root replacement (ARR). Experienced, high-volume aortic centers have demonstrated the safety of VSRR in young, hemodynamically stable patients presenting with TAAD. In conclusion, aortic root repair can safely be performed in the vast majority of patients with TAAD. Despite the increased surgical complexity, ARR does not increase operative mortality and improves the freedom from root reintervention. VSRR can be performed in highly selected populations of patients with TAAD with durable mid-term valve function.

Usefulness of a new gelatin glue sealant system for dural closure in a rat durotomy model

Watertight dural closure is imperative after neurosurgical procedures, because inadequately treated leakage of cerebrospinal fluid (CSF) can have serious consequences. We used a rat durotomy model to test the usefulness of a new gelatin glue as a dural sealant in a rat model of transdural CSF leakage. All rats were randomly divided into one of the following three treatment groups: no application (control group: N = 18), application of fibrin glue (fibrin glue group: N = 18), and application of the new gelatin glue (new gelatin glue group: N = 18). The craniotomy side was re-opened, and CSF leakage was checked and recorded at 1, 7, and 28 days postoperatively. The new gelatin glue was adequate for stopping CSF leakage; no leakage was observed at postoperative days 1 or 7, and leakage was observed in only one rat at postoperative day 28. This result was statistically significant when compared to the control group (P = 0.002, P = 0.015, P = 0.015, respectively). The pathologic score of the new gelatin group was not different from that of the control or fibrin glue groups. We conclude that our new gelatin glue provides effective watertight closure 1, 7, and 28 days after operation in the rat durotomy model.

Effectiveness of a new gelatin sealant system for dural closure

OBJECTIVES

Watertight dural closure is imperative after neurosurgical procedures because inadequately treated leakage of cerebrospinal fluid (CSF) can have serious consequences. In this study, the authors test the use of a new gelatin glue as a dural sealant in in vitro and in vivo canine models of transdural CSF leakage.

METHODS

The in vitro model was sutured semicircles of canine dura mater and artificial dural substitute. The sutures were sealed with gelatin glue (n  =  20), fibrin glue (n  =  20), or a polyethylene glycol (PEG)-based hydrogel sealant (n  =  20). Each sample was set in a device to measure water pressure, and pressure was increased until leakage occurred. Bonding strength was subjectively evaluated. The in vivo model was dogs who underwent dural excision and received either no sealant (control group; n  =  5) or gelatin glue sealant (n  =  5) before dural closure. Twenty-eight days post-surgery, the maximum intracranial pressure was measured at the cisterna magna using Valsalva maneuver and tissue adhesion was evaluated.

RESULTS

The water pressure at which leakage occurred in the in vitro model was higher with gelatin glue (76·5 ± 39·8 mmHg) than with fibrin glue (38·3 ± 27·4 mmHg, P < 0·001) or the PEG-based hydrogel sealant (46·3 ± 20·9 mmHg, P  =  0·007). Bonding strength was higher for the gelatin glue than fibrin glue (P < 0·001) or PEG-based hydrogel sealant (P  =  0·001). The maximum intracranial pressure in the in vivo model was higher for the gelatin glue group (59·0 ± 2·2 mmHg) than the control group (13·8 ± 4·0 mmHg, P < 0·001). Tissue adhesion was lower for the gelatin glue group than the control group (P  =  0·005).

DISCUSSION

The new gelatin glue provides an effective watertight closure when used as an adjunct to sutured dural repair.

Partial root remodeling on the two sinuses for acute type a aortic dissection with right coronary arterial dissection

We reported simple partial root remodeling using a graft trimmed twin "U" shape for extensive dissection into the right/non-coronary sinuses with acute type A aortic dissection with cardiac tamponade, acute myocardial infarction on the right coronary artery and aortic regurgitation. After total arch replacement with frozen elephant trunk technique for distal dissection, partial root remodeling on the non and right coronary sinuses was performed. Postoperative computed tomography (CT) showed well shaped Valsalva sinuses and aortic regurgitation completely disappeared. This technique might become an alternative procedure for aortic dissection severely involving Valsalva sinuses without dilatation on the aortic root.

Hybrid debranching and TEVAR of the aortic arch off-pump, in re-do patients with complicated chronic type-A aortic dissections: a critical report

Background

Patients suffering from acute type A aortic dissection undergo replacement of the ascending aorta, the proximal hemiarch or complete aortic arch, depending on the extent of the individual pathology. In a subset of these treated patients, secondary pathologies of the distal anastomosis or the remaining distal part of the aorta occur. The treatment of these pathologies is challenging, requiring major surgical re-do procedures with aortic arch replacement under extracorporeal circulation and hypothermic circulatory arrest.

Methods

We report our experience of five patients with complex aortic pathologies after previous aortic surgery treated with a single stage re-do hybrid procedure, consisting of bypass grafting of the supraaortic branches off-pump, stent graft placement for endovascular aortic repair (TEVAR) and surgical debranching of the aortic arch.

Results

In all patients the surgical vascular grafts and stent grafts were deployed successfully, there were no intraoperative deaths. Four out of five patients were discharged from hospital in good clinical condition. One patient died postoperatively due to cardiac tamponade. In one patient a type I endoleak persisted leading to occlusion of a bypass branch requiring surgical revision at one year after debranching.

Conclusion

We discuss the prerequisites, all steps and potential pitfalls of this hybrid aortic arch replacement. The current procedure avoids cardiopulmonary bypass and circulatory arrest, which may benefit early patient outcome; however, patient and device selection plays a key role for immediate success and midterm outcomes. In addition, precise procedural planning and development of customized stents may help to develop this procedure into a true alternative for conventional aortic arch replacement.

Sealing effects of cross-linked gelatin

Surgical sealants form gel when applied to tissues. Currently, fibrin sealant has been successfully used in many surgical fields, but it has several disadvantages, including possible virus transmission, low adhesive strength, and high cost. In this study, gelatin and glutaraldehyde (GA) solutions were chosen to demonstrate the effectiveness of cross-linked gelatin gel as sealant and barrier, both of which have long been used in medical applications. It was found that the gelatin gel prepared from 26 wt% gelatin and 1 wt% GA solutions exhibited bonding strength almost three times higher than that of fibrin glue. The bonding strength increased with the increasing gelatin and GA concentrations. When a needle hole on PTFE vascular grafts was sealed with the gelatin gel, the water-resistant pressure significantly increased upon rubbing and was twice higher than that of fibrin glue. The cytotoxicity of gelatin gel was found to be much lower than that of albumin glue prepared at the same composition as commercially available BioGlue®. The gelatin gel was found to be also effective as barrier to prevent adhesion in a rat cecum abrasion model.

Characterization of star adhesive sealants based on PEG/dextran hydrogels

Swellable PEG amine/dextran aldehyde composite materials are emerging as a controlled, biocompatible tissue adhesive. We explain how preservation of natural tissue amines provides biocompatibility for PEG/dextran that exceeds the stringent, destructive cyanide-based chemistry of cyanoacrylates, and adhere far better than fibrin glue. Strategic variations of material composition allow for the improvement of biocompatibility and adhesion strength. Material variations can be tailored to match the needs of specific tissue beds for an array of clinical applications. PEG/dextran cohesive properties are most responsive to variations in the PEG component (number of arms and solid content), while tissue/material adhesion strength is primarily determined by the number of aldehydes in the dextran.

Left main coronary stenosis as a consequence of bentall operation: percutaneous treatment

A 65-year-old man suffering from ascending aorta aneurysm and atherosclerotic three vessel disease without left main involvement underwent aortic root replacement with coronary ostia reimplantation according to the modified Bentall technique and multiple coronary artery bypass grafts. Gelatin-resorcin-formaldehyde glue was used to reinforce the aortic coronary buttons and to facilitate hemostasis. Five months after surgery, the patient experienced rapidly worsening effort angina. Coronary angiography showed severe left main narrowing. The considerable amount of time that elapsed between surgery and the onset of symptoms implies that the problem was not related to an imperfect suture technique, but was most likely caused by an inflammatory and proliferative response to the glue that had been used. We performed elective percutaneous coronary intervention and stenting of the protected coronary vessel without technical difficulties and with a satisfactory final result. The patient is currently symptom-free after 1 year's follow-up.

Descending thoracic aortic dissections

Type B dissection has traditionally been managed medically if uncomplicated and surgically if associated with complications. This practice has resulted in most centers reporting significant morbidity and mortality if open repair is required. In the setting of malperfusion, operative repair has been conjoined with fenestration or visceral stenting to improve outcomes. Endovascular stent grafts seem to offer an attractive alternative in the acute complicated type B dissection, with reduced mortality and morbidity, particularly paralysis, compared with open repair. It is reasonable to consider endovascular stent grafts as another tool in managing dissection, but to recognize that open surgical repair still plays an important role, and that the data that define indications and outcomes are still emerging.