Category: General

Materials (Basel). 2023 Dec 27;17(1):134. doi: 10.3390/ma17010134.

ABSTRACT

The aim of this study was to compare the viscoelastic properties of a decellularized mesh from the porcine esophagus, prepared by our group, with two commercial acellular tissues derived from porcine small intestine submucosa and bovine pericardium for use in medical devices. The tissues’ viscoelastic properties were characterized by creep tests in tension, applying the load in the direction of the fibers or the transverse direction, and also by dynamic-shear mechanical tests between parallel plates or in tension at frequencies between 0.1 and 35 Hz. All the tests were performed in triplicate at a constant temperature of 37 °C immersed in distilled water. The tissues’ surface and cross-sectional microstructure were observed by scanning electron microscopy (SEM) to characterize the orientation of the fibers. The matrices of the porcine esophagus present an elastic modulus in the order of 60 MPa when loaded in the longitudinal direction while those of the porcine intestine submucosa and bovine pericardium have an elastic modulus below 5 MPa. Nevertheless, the shear modulus of bovine pericardium nearly triplicates that of the esophageal matrix. The viscoelasticity of decellularized esophageal mucosa is characterized by a fast change in the creep compliance with time. The slope of the creep curve in the double logarithmic plot is twice that of the control samples. These results are consistent with the microstructure observed under electron microscopy regarding the orientation of the fibers that make up the matrices.

PMID:38203987 | PMC:PMC10779732 | DOI:10.3390/ma17010134

Sci Prog. 2024 Jan-Mar;107(1):368504231221686. doi: 10.1177/00368504231221686.

ABSTRACT

PURPOSE.: The treatment of infectious aortic disease is still challenging with open surgical debridement and reconstruction using biological, preferably autologous material, being the treatment of choice. However, these procedures are associated with high morbidity and mortality. Endovascular therapy is often considered a bridging method only, since the biologically inactive fabric of the covered stent grafts usually cannot be treated sufficiently with anti-infective agents in the event of a (obligate) consecutive secondary graft infection. This study aims to prove the feasibility of a physician-made pericardium stent graft ex-vivo.

TECHNIQUE.: A state-of-the-art TEVAR was modified by separating the fabric from the z-stents and suturing a hand-sewn bovine pericardium tube to the bare metal. Feasibility of preparation, re-sheathing, and delivery is demonstrated in an ex-vivo model.

CONCLUSION.: This first xenogeneic stent graft could be manufactured and deployed successfully. In the future this may provide a bridging alternative for high-risk patients with infected native aortic aneurysm or aortic fistulas, eventually followed by surgical or thoracoscopic/laparoscopic debridement. Further studies on simulators or animal models are needed to test the technique and investigate its long-term durability. Additionally, this study prompts reflection on whether materials currently used should be further developed to prevent graft infections.

PMID:38196177 | PMC:PMC10777807 | DOI:10.1177/00368504231221686

J Neurol Surg Rep. 2024 Feb 12;85(1):e23-e24. doi: 10.1055/a-2244-1143. eCollection 2024 Jan.

ABSTRACT

Hemifacial spasm is a neuromuscular disorder caused by compression of the facial nerve at the nerve root entry zone, often due to ectatic or aberrant vasculature. Pathologic compression of the nerve-brainstem interface results in involuntary, paroxysmal contractions of ipsilateral facial muscles that may cause considerable impairments in quality of life. For those with severe symptoms, have positive imaging demonstrating vascular compression, or who fail other management modalities, 1 2 3 4 microvascular decompression offers potential definitive treatment. 5 6 Traditionally, nonabsorbable packing agent is used to pack between the nerve and offending vascular structure. However, for large and more complex arterial structures, simple nonabsorbable padding is often not sufficient. In this operative video, we demonstrate microvascular decompression for intractable hemifacial spasm in a 52-year-old female using a specialized sling tacked to the petrous dura for management of a large, ectatic vertebral artery. Following a standard left retrosigmoid craniotomy, an atheromatous ectatic vertebral artery was identified. We fashioned a bovine pericardium sling around the vessel and used a permanent aneurysm clip to secure it to an incision portion of petrous dura. We subsequently identified potential additional facial nerve root compression by anterior inferior cerebellar artery (AICA) and posterior inferior cerebellar artery (PICA) branches, which were elevated and secured using Teflon felt packing. Following elevation of all three vessels, the lateral spread response resolved. At 2 weeks postoperatively, the patient reported substantial relief in her hemifacial spasms and endorsed highly improved quality of life.

PMID:38348014 | PMC:PMC10861316 | DOI:10.1055/a-2244-1143