How to test adhesive strength: a biomechanical testing for aortic glue used in type a dissection repair

OBJECTIVES

The aim of this study was to develop a method to quantify the peel force in an in vitro model simulating repair of ascending aortic dissections with tissue glue (Bioglue).

METHODS

This study adapted an adhesive T-Peel test for the determination of the peel strength of adhesives by measuring the peeling force of a T-shaped bonded tissue. Measurements were performed on iatrogenic dissected ascending porcine aorta, which has been repaired with Bioglue using different pressure levels. Four conditions were tested: zero sample pressure according to the manufacturer's recommendation (n = 10), low (504 Pa; n = 11), moderate pressure (1711 Pa; n = 24) and pressure applied by a round shaped vascular 'Borst clamp' (1764 Pa; n = 23). Non-parametric one-way analysis of variance was applied for statistical significance.

RESULTS

The median peel force (lower quartile, upper quartile) of aortic samples increased depending on the applied pressure: [no pressure 0.030 N/mm (0.016, 0.057), low pressure 0.040 N/mm (0.032, 0.070) and moderate pressure 0.214 N/mm (0.050, 0.304)]. Samples pressurized with the Borst clamp reached 0.078 N/mm (0.046, 0.152), which was comparable to the peel force of the unpeeled controls [0.107 N/mm (0.087, 0.124)]. Compared to samples without pressure, Bioglue with the application of the Borst clamp (P = 0.021) and with moderate pressure (P = 0.0007) performed significantly better.

CONCLUSIONS

The novel T-Peel test offers an attractive method to test tissue glues in defined in vitro environments. Bioglue peel force increased with pressure on the aortic sample in contrast to low or no pressure as per the manufacturer's recommendation. Modifying current recommended use may aid in increasing effectiveness of this approach.

Iatrogenic Acute Ascending Aortic Dissection During Combined Heart/Liver Transplant for Amyloidosis

We report a case of iatrogenic acute type A aortic dissection (ATAAD) during a combined heart-liver transplant in a patient with amyloid-associated cardiac and hepatic failure. The patient developed ATAAD of the recipient's aorta during the heart transplantation. Because there was no sign of malperfusion or proximal extension into the donor aorta, we proceeded with the liver transplantation and continued medical management for ATAAD. The patient was discharged uneventfully 30 days after the transplant, and computed tomography coronary angiogram after 4 months showed stable dissection. During a heart transplant, ATAAD of the native aorta without malperfusion syndrome can be managed conservatively with close progress monitoring.

Life-Threatening Aortic Dissection during Pregnancy: A Case Report of Undiagnosed FBN1-Related Marfan Syndrome at 39 Weeks Gestation

BACKGROUND Inherited deficiencies in the FBN1 gene, which encodes fibrillin-1, result in Marfan syndrome, an autosomal dominant connective tissue disorder that is associated with aortic root dilatation and predisposes to aortic dissection. This report is of a 37-year-old woman presenting at 39 weeks of pregnancy with acute thoracic aortic dissection due to previously undiagnosed FBN1-related Marfan syndrome. This case report aims to illustrate the challenges in the diagnosis and in the peri-operative management of acute aortic dissection during pregnancy. CASE REPORT A healthy 37-year-old woman at 39 weeks of gestation presented to our hospital with dyspnea and chest pain. Initial evaluation for pulmonary embolism with chest computed tomography was unrevealing. The patient was admitted to the intensive care unit for further management. Overnight, her clinical conditions deteriorated, and a transthoracic echocardiography was obtained, demonstrating an acute ascending aortic dissection. She emergently underwent a successful combined cesarean section and ascending aortic dissection repair, with no immediate complications. On postoperative day 4 she developed cardiac tamponade, for which she underwent emergent mediastinal exploration. She was discharged home on postoperative day 10. A month later she completed genetic testing, which revealed a pathogenic mutation in the FBN1 gene, consistent with a molecular diagnosis of Marfan syndrome. CONCLUSIONS This report has shown that FBN1-related Marfan's syndrome has a variable clinical presentation that can include life-threatening aortic dissection during pregnancy. Successful diagnosis and management of these patients is challenging and requires multidisciplinary expertise, including confirmation of the diagnosis by a clinical geneticist.

Debranching Thoracic Endovascular Aortic Repair Combined with Ascending Aortic Banding: Analysis of a New Surgical Procedure

BACKGROUND

To analyze the clinical effect of debranching thoracic endovascular aortic repair combined with ascending aortic banding.

METHODS

The clinical data of patients who underwent a debranching thoracic endovascular aortic repair combined with ascending aortic banding at Anzhen Hospital (Beijing, China) between January 2019 and December 2021 were reviewed to evaluate the occurrence and outcomes of postoperative complications.

RESULTS

A total of 30 patients underwent a debranching thoracic endovascular aortic repair combined with ascending aortic banding. There were 28 male patients (93.3%) with an average age of 59.9 ± 11.8 years. Twenty-five patients underwent simultaneous surgery and five patients had staged surgery. Postoperatively, two patients developed complete paraplegia (6.7%), three patients developed incomplete paraplegia (10%), two patients developed cerebral infarction (6.7%), and one patient developed femoral artery thromboembolism (3.3%). No patient died during the perioperative period, and one patient (3.3%) died during the follow-up period. None of the patients underwent retrograde type A aortic dissection during the perioperative and postoperative follow-up periods.

CONCLUSIONS

Banding the ascending aorta with a vascular graft to restrict its movement and to serve as the proximal anchoring area of the stent graft can reduce the risk of retrograde type A aortic dissection.

Subendocardial Ischemia Caused by Acute Severe Aortic Regurgitation Due to Aortic Root Dissection: A Case Report and Literature Review

Electrocardiogram (ECG) findings showing ST-segment depression in a wide range of leads and ST-segment elevation in aVR are found in patients with acute coronary syndrome with multivessel coronary lesions and left main trunk lesions. A 64-year-old man with a history of eosinophilic granulomatosis presented with chest pain and dyspnea. Although an ECG showed the above findings, he was diagnosed with acute severe aortic regurgitation (AR) complicating aortic root dissection and successfully underwent urgent Bentall operation. These ECG findings indicated that acute severe AR caused subendocardial ischemia.