Clinical Experience of the PK Papyrus Covered Stent in Patients With Coronary Artery Perforations: Results From a Multi-Center Humanitarian Device Exemption Survey.

BACKGROUND/PURPOSE: The PK Papyrus covered coronary stent system (Biotronik AG, Bülach, Switzerland) is intended for treatment of coronary artery perforation (CAP) and is approved for use under a Humanitarian Device Exemption (HDE) in the United States (US). METHODS/MATERIALS: The retrospective data analysis includes cases reported from the US PK Papyrus HDE post-market surveillance clinical dataset with CAP cited as the reason for PK Papyrus stent use. RESULTS: From April 2019 to July 2021, PK Papyrus device registration forms citing CAP as the reason for use were received for 1094 cases from 335 US hospital programs. Ellis classification was assessed as: type III cavity spilling/IV, 11.0%; type III, 57.9%; type II, 23.8%; type I, 7.3%. Mechanisms of perforation included: balloon angioplasty (42.3%), stent placement (31.3%), atherectomy (13.9%), and guidewire (10.9%). The majority (72.6%) of cases involved single covered stent placement. Successful PK Papyrus delivery was reported in 97.7% of cases with successful perforation sealing in 92.1%. Emergency cardiac surgery and in-hospital death occurred in 6.3% and 12.4% of cases, respectively. Pericardiocentesis was performed in 30.2% of patients. Acute/subacute stent thrombosis occurred in 10 patients (1.1%). CONCLUSION: As the largest dataset of patients treated with a covered stent for CAP, these data provide significant insight into patient characteristics, procedural outcome, and in-hospital clinical events associated with this life-threatening complication. These results demonstrate that the PK Papyrus stent is a safe and effective method to seal CAP and with the potential to reduce high morbidity and mortality associated with this event.

Structural and cellular characterization of electrospun recombinant human tropoelastin biomaterials.

An off-the-shelf vascular graft biomaterial for vascular bypass surgeries is an unmet clinical need. The vascular biomaterial must support cell growth, be non-thrombogenic, minimize intimal hyperplasia, match the structural properties of native vessels, and allow for regeneration of arterial tissue. Electrospun recombinant human tropoelastin (rTE) as a medial component of a vascular graft scaffold was investigated in this study by evaluating its structural properties, as well as its ability to support primary smooth muscle cell adhesion and growth. rTE solutions of 9, 15, and 20 wt% were electrospun into sheets with average fiber diameters of 167 ± 32, 522 ± 67, and 735 ± 270 nm, and average pore sizes of 0.4 ± 0.1, 5.8 ± 4.3, and 4.9 ± 2.4 µm, respectively. Electrospun rTE fibers were cross-linked with disuccinimidyl suberate to produce an insoluble fibrous polymeric recombinant tropoelastin (prTE) biomaterial. Smooth muscle cells attached via integrin binding to the rTE coatings and proliferated on prTE biomaterials at a comparable rate to growth on prTE coated glass, glass alone, and tissue culture plastic. Electrospun tropoelastin demonstrated the cell compatibility and design flexibility required of a graft biomaterial for vascular applications.

Mechanical property characterization of electrospun recombinant human tropoelastin for vascular graft biomaterials.

The development of vascular grafts has focused on finding a biomaterial that is non-thrombogenic, minimizes intimal hyperplasia, matches the mechanical properties of native vessels and allows for regeneration of arterial tissue. In this study, the structural and mechanical properties and the vascular cell compatibility of electrospun recombinant human tropoelastin (rTE) were evaluated as a potential vascular graft support matrix. Disuccinimidyl suberate (DSS) was used to cross-link electrospun rTE fibers to produce a polymeric recombinant tropoelastin (prTE) matrix that is stable in aqueous environments. Tubular 1cm diameter prTE samples were constructed for uniaxial tensile testing and 4mm small-diameter prTE tubular scaffolds were produced for burst pressure and cell compatibility evaluations from 15 wt.% rTE solutions. Uniaxial tensile tests demonstrated an average ultimate tensile strength (UTS) of 0.36±0.05 MPa and elastic moduli of 0.15±0.04 and 0.91±0.16 MPa, which were comparable to extracted native elastin. Burst pressures of 485±25 mm Hg were obtained from 4mm internal diameter scaffolds with 453±74 µm average wall thickness. prTE supported endothelial cell growth with typical endothelial cell cobblestone morphology after 48 h in culture. Cross-linked electrospun rTE has promising properties for utilization as a vascular graft biomaterial with customizable dimensions, a compliant matrix and vascular cell compatibility.

Laparoscopic repair of inferior vena caval injury using a chitosan-based hemostatic dressing.

BACKGROUND: Vena caval injury is a rare but serious complication of laparoscopic surgery, and often requires conversion to an open procedure. The current study investigated whether a vena caval injury could be repaired with a chitosan dressing laparoscopically. METHODS: Six domestic swine were studied. A 4- to 5-mm circumferential incision was created in the inferior vena cava (IVC) and repaired laparoscopically with a chitosan dressing. Neither suture nor additional hemostatic techniques were used. The animals were killed at 30 minutes (n = 2) and at 1 week (n = 4) postoperatively for histopathological analysis. RESULTS: All IVC injuries were successfully repaired laparoscopically using a single chitosan dressing application without recurrent hemorrhaging. Mean operative time was 6 minutes and the blood loss was approximately 55 mL. There was no evidence of clot formation in the repaired vessels. Histology showed that the chitosan dressing had partially degenerated into small particles with moderate chronic inflammatory response 1 week after repair. CONCLUSION: Use of the chitosan-based hemostatic dressing is a simple and reliable technique to control serious hemorrhage from IVC injury during laparoscopic surgery.