Bone Regeneration: A Novel Osteoinductive Function of Spongostan by the Interplay between Its Nano- and Microtopography.

Scaffold materials for bone regeneration are crucial for supporting endogenous healing after accidents, infections, or tumor resection. Although beneficial impacts of microtopological or nanotopological cues in scaffold topography are commonly acknowledged, less consideration is given to the interplay between the microscale and nanoscale. Here, micropores with a 60.66 ± 24.48 µm diameter ordered by closely packed collagen fibers are identified in pre-wetted Spongostan, a clinically-approved collagen sponge. On a nanoscale level, a corrugated surface of the collagen sponge is observable, leading to the presence of 32.97 ± 1.41 nm pores. This distinct micro- and nanotopography is shown to be solely sufficient for guiding osteogenic differentiation of human stem cells in vitro. Transplantation of Spongostan into a critical-size calvarial rat bone defect further leads to fast regeneration of the lesion. However, masking the micro- and nanotopographical cues using SiO2 nanoparticles prevents bone regeneration in vivo. Therefore, we demonstrate that the identified micropores allow migration of stem cells, which are further driven towards osteogenic differentiation by scaffold nanotopography. The present findings emphasize the necessity of considering both micro- and nanotopographical cues to guide intramembranous ossification, and might provide an optimal cell- and growth-factor-free scaffold for bone regeneration in clinical settings.

German multicenter real-world registry of stenting for superficial femoral artery disease: clinical results and predictive factors for revascularization.

PURPOSE: To investigate nitinol stent treatment of superficial femoral artery (SFA) lesions and the impact of different risk factors on the need for clinically driven target lesion revascularization (TLR) in a large, real-world population of claudicants. METHODS: Patients presenting with symptomatic SFA stenosis >70% were consecutively enrolled in the 13-center MARIS prospective registry (ClinicalTrials.gov identifier NCT01067885). There was no restriction on lesion length, thus leading to the inclusion of a real-world as well as high-risk patient cohort. The 998 participating patients (657 men; mean age 67.4±9.2 years) had 1050 lesions treated with the same nitinol stent type. The mean lesion length was 9.5±9.6 cm (range 0.5-44; median 8.0); more than a third of the lesions (450, 42.9%) were total occlusions. The primary endpoint was the need for clinically driven target lesion revascularization (TLR) at 12 months. RESULTS: Acute technical success was achieved in 1042 (99.2%) lesions. Restenosis occurred in 187 (23.7%) and reocclusion in 79 (10.0%) lesions at 12 months. The primary endpoint of TLR at 12 months was reached by 136 (17.2%) patients. The periprocedural complication rate was 5.4%. Independent predictors of TLR were female gender [odds ratio (OR) 0.5, 95% confidence interval (CI) 0.3 to 0.7, p<0.001] and lesion length >20 cm vs. 10 cm (OR 2.7, 95% CI 1.1 to 6.6, p=0.029) and 10-20 cm vs. 10 cm (OR 1.9, 95% CI 1.0 to 4.1, p=0.047). CONCLUSION: Stent implantation in the SFA is safe and associated with favorable acute and midterm results in a real-world setting. Lesion length and female gender were identified as independent risk factors for TLR.

Explantation of totally implantable venous access ports of the forearm: reasons for removal and observed complications.

PURPOSE: To evaluate indications for, and complications during, explantation of interventionally placed totally implantable venous access ports (TIVAPs) of the forearm. BACKGROUND: Many studies analyze the explantation procedure of pectorally placed TIVAPs. The literature on TIVAPs in the forearm is limited, and the explantation procedure of these devices in the forearm has not been sufficiently evaluated yet. METHODS: We retrospectively reviewed the archives of our institute between May 2006 and May 2009 and identified 850 TIVAPs that had been implanted in the forearm. Of these TIVAPs, 145/850 (80 in women, 65 in men; mean age 52 years, range 15-82 years) were explanted during this period either by interventionists (n=109) or by general surgeons (n=36). RESULTS: Mean catheter survival was 322 days. Reasons for explantation were end of therapy (63.4%), infection (29.0%), thrombosis (3.4%), occlusion (1.4%), or dislocation (1.4%) of the TIVAP. Primary technical success rate was 97.2% for the surgical as well as for the interventional procedure. The overall success rate was 100%. The reasons for retrieval failure by interventionists (3/108) as well as by surgeons (1/36) were post-thrombotic adhesions of the port catheter to the blood vessel wall. CONCLUSIONS: Removal of TIVAPs of the forearm shows a high technical success rate and a low complication rate. End of therapy is the most common indication for explantation. There is a low risk of interventional removal failure with a resulting need for open surgery to remove the device.

Peripherally placed totally implantable venous-access port systems of the forearm: clinical experience in 763 consecutive patients.

The aim of this study is to evaluate the effectiveness and safety of percutaneously placed totally implantable venous-access ports (TIVAPs) of the forearm. Between January 2006 and October 2008, peripheral TIVAPs were implanted in 763 consecutive patients by ultrasound and fluoroscopic guidance. All catheters were implanted under local anesthesia and were tunneled subcutaneously. Indication, technical success, and complications were retrospectively analyzed according to Society of Interventional Radiology (SIR) criteria. Presence of antibiotic prophylaxis, periprocedurally administered drugs (e.g., sedation), and laboratory results at the time of implantation were analyzed. Maintenance during the service interval was evaluated. In total, 327,499 catheter-days were analyzed. Technical success rate was 99.3%. Reasons for initial failure of implantation were either unexpected thrombosis of the subclavian vein, expanding tumor mass of the mediastinum, or failure of peripheral venous access due to fragile vessels. Mean follow-up was 430 days. There were 115 complications observed (15.1%, 0.03 per 100 catheter-days), of which 33 (4.3%) were classified as early (within 30 days from implantation) and 82 (10.7%) as late. Catheter-related venous thrombosis was found in 65 (8.5%) of 763 (0.02 per 100 catheter-days) TIVAPs. Infections were observed in 41 (5.4%) of 763 (0.01 per 100 catheter-days) devices. Other complications observed included dislocation of the catheter tip (0.8%), occlusion (0.1%), or rupture (0.1%) of the port catheter. Dislocated catheters were corrected during a second interventional procedure. In conclusion, implantation of percutaneously placed peripheral TIVAPs shows a high technical success rate and low risk of early complications when ultrasound and fluoroscopic guidance are used. Late complications are observed three times as often as early complications.

Nitinol stent implantation in TASC A and B superficial femoral artery lesions: the Femoral Artery Conformexx Trial (FACT).

PURPOSE: To investigate the impact of nitinol stenting of superficial femoral artery (SFA) lesions with a maximum length of 10 cm (TASC-II A or B) on 1-year outcomes compared to a historical study cohort from the Femoral Artery Stent Trial (FAST). METHODS: Between January 2004 and August 2005, 6 study sites enrolled 110 symptomatic patients (75 men; mean age 68+/-9 years) with a single de novo >70% SFA lesion <10 cm long treated with the self-expanding nitinol Conformexx stent. The primary study endpoint was binary restenosis determined by duplex ultrasound at 12 months. Secondary 12-month endpoints were target lesion revascularization (TLR), ankle-brachial index (ABI), mean Rutherford category, >1-class change in Rutherford category, and major adverse events. Data were analyzed according to the intention-to-treat principle and according to the actual treatment received ("on treatment" analysis). Outcomes were compared to the historical balloon angioplasty (BA) arm and the Luminexx 3 stent arm of the randomized FAST study. RESULTS: Technical success was achieved in 106 (96%) patients; at 1 year, the primary endpoint of ultrasound-assessed binary restenosis was reached in 14 (23.3%) of 60 patients (95% CI 13.4% to 36%). This restenosis rate was lower versus the historical BA (38.6%, p=0.057) or Luminexx 3 stent controls (31.7%, p=0.284) from FAST. The clinically driven TLR was 7.4% (7 of 94 clinically controlled patients), which was also lower compared to 18.3% (p=0.098) and 14.9% (p=0.267) for the historical BA and Luminexx 3 stent groups, respectively. The mean Rutherford category was reduced from 2.75+/-0.79 to 0.94+/-1.38 (p<0.0001); 85.1% were improved by at least 1 Rutherford category. The ABI increased from 0.62+/-0.15 to 0.85+/-0.20 (p<0.0001). CONCLUSION: This study of patients with SFA lesions documented favorable outcomes using nitinol stents in TASC-II A or B lesions after 1 year. The study was underpowered to prove superiority of the Conformexx nitinol stent design compared to historical balloon only or Luminexx 3 stent groups.