Polyethylene glycol-coated collagen patch (hemopatch®) in open partial nephrectomy

Purpose To describe the results of a polyethylene glycol-coated collagen patch, Hemopatch® on blood loss, surgical time and renal function in partial nephrectomy (PN) for renal cell carcinoma (RCC). Methods Out of a single surgeon cohort of n = 565 patients undergoing conventional open PN (CPN) between 01/2015 and 12/2017 at the University of Munich a consecutive subgroup (n = 42) was operated on using a polyethylene glycol-coated collagen-based sealant Hemopatch® (Baxter International Inc., Deerfield, IL, USA) (HPN). Results Median age was 65.2 years (range 12.7–95.2) with median follow-up of 9.43 months (0.03–49.15). Baseline renal function (CKD-EPI) was 78.56 ml/min/1.73 m2 (range 20.38–143.09) with a non-significant decline to 74.78 ml/min/1.73 m2 (range 3.75–167.74) at follow-up. In CPN 46% had low complexity, 33% moderate complexity and 20% high complexity lesions with 33% low, 40% moderate and 27% high complexity masses in HPN. Median tumor size was 4.3 cm (range 1–38 cm) in CPN with 4.8 cm (range 3.8–18.3 cm) with HPN, p = 0.293. Median blood loss and duration of surgery was significantly lower in the HPN group vs. CPN (146 ml ± 195 vs. 114 ml ± 159 ml; p = 0.021; 43 min ± 27 for HPN vs. 53 min ± 49; p = 0.035) with no difference in clamping time (12.6 min ± 8.6 for HPN vs. 12.0 min ± 9.5; p = 0.701). Conclusions Hemopatch® supported renoraphy shows promising results compared to standard renoraphy in PN. No side effects were seen. Further studies should evaluate the prevention of arterio-venous or urinary fistulas. In complex partial nephrectomies Hemopatch® supported renoraphy should be considered.

Biomimetic reduced graphene oxide coated collagen scaffold for in situ bone regeneration

A variety of bone-related diseases and injures and limitations of traditional regeneration methods require new tissue substitutes. Tissue engineering and regeneration combined with nanomedicine can provide different natural or synthetic and combined scaffolds with bone mimicking properties for implantation in the injured area. In this study, we synthesized collagen (Col) and reduced graphene oxide coated collagen (Col-rGO) scaffolds, and we evaluated their in vitro and in vivo effects on bone tissue repair. Col and Col-rGO scaffolds were synthesized by chemical crosslinking and freeze-drying methods. The surface topography, and the mechanical and chemical properties of scaffolds were characterized, showing three-dimensional (3D) porous scaffolds and successful coating of rGO on Col. The rGO coating enhanced the mechanical strength of Col-rGO scaffolds to a greater extent than Col scaffolds by 2.8 times. Furthermore, Col-rGO scaffolds confirmed that graphene addition induced no cytotoxic effects and enhanced the viability and proliferation of human bone marrow-derived mesenchymal stem cells (hBMSCs) with 3D adherence and expansion. Finally, scaffold implantation into rabbit cranial bone defects for 12 weeks showed increased bone formation, confirmed by Hematoxylin–Eosin (H&E) and alizarin red staining. Overall, the study showed that rGO coating improves Col scaffold properties and could be a promising implant for bone injuries.

A prospective, randomized, pilot trial of a polyethylene glycol (PEG)-coated collagen patch (Hemopatch®) for intraoperative hemostasis during deceased donor renal transplant

Introduction: The objective of this study was to evaluate the safety and feasibility of using a polyethylene glycol (PEG)-coated collagen patch (Hemopatch®) in patients undergoing deceased donor renal transplant. The primary outcome was the amount of intraoperative estimated blood loss in those patients receiving the patch compared to without. Secondary outcomes were the subjective achievement of hemostasis, perigraft collection, and drop in hemoglobin 48 hours postoperatively. Methods: We performed a single-center, prospective, randomized trial. Patients scheduled to undergo deceased donor renal transplant surgery were randomized to receive the PEG-coated patch or standard hemostasis (i.e., electrocautery and clips). Results: A total of 30 patients were enrolled over 15 months and randomized to receive the PEG-coated patch (n=15) or standard hemostasis (n=15). The mean age was 62.5 years. As determined by the operating surgeon, hemostasis was successfully achieved in all 15 cases using the PEG-coated patch. In the PEG-coated patch group, there was a trend towards less estimated blood loss (237 cc vs. 327 cc; p=0.11) and a lower drop in hemoglobin 48 hours postoperatively (22.27 g/L vs. 29.53 g/L; p=0.09) compared to the standard hemostasis group. Perigraft collection was similar between groups (27% vs. 40%; p=0.43). Subgroup analysis on patients who received anticoagulation therapy revealed no significant difference in blood loss between groups. Conclusions: Based on our single-center experience, the PEG-coated patch (Hemopatch®) is a safe and feasible option to aid hemostasis during deceased donor renal transplant surgery. Hemostasis was successfully achieved in all cases using the PEG-coated patch.