ECG-guided PICC insertion using a new silicon catheter with a conductive tip: A retrospective clinical study.

OBJECTIVE: Safety and efficacy of ECG-guided PICC insertion using a new silicon catheter with a conductive tip was evaluated in daily practice. METHODS: A retrospective study was conducted on 1659 patients who accepted successful tip-conductive PICC placement and clinically followed-up until the catheter removal between January 2018 and April 2019. Baseline of patient characteristics, catheter placement characteristics, date of dressing changes as well as records of catheter-related complications were extracted from a special designed mobile APP. RESULTS: The first-attempt success (success of placing catheter tip to the ideal position by primary indwelling operation) rate of PICC placement was 99.3%. The average duration of PICC placement was 128.7 ± 39.5 days and 1535 patients (92.5%) reached the therapy end-point without any complications and removed the catheter normally. The cumulative rates of total complications were 7.5%, including exit site infection (2.5%), phlebitis (0.9%), DVT (1.0%), catheter malposition (1.1%), catheter breakage (0.1%), and liquid extravasation (1.8%). In multivariable logistic regression analyses, hyperlipidemia, diabetes mellitus, lung cancer, stomach cancer, and lymphoma were significantly associated with increased risk of complications, as the independent risk factors. CONCLUSIONS: This retrospective clinical study demonstrates that ECG-guided insertion of a new tip-conductive PICC is associated with a high rate of first-attempt success and low rate of catheter related complications.

Systematic Review and Meta-Analysis of Antibiotic-Impregnated Shunt Catheters on Anti-Infective Effect of Hydrocephalus Shunt.

OBJECTIVE: Shunt infection is a common complication while treating hydrocephalus. The antibiotic-impregnated shunt catheter (AISC) was designed to reduce shunt infection rate. A meta-analysis was conducted to study the effectiveness of AISCs in reduction of shunt infection in terms of age, follow-up time and high-risk patient population. METHODS: This study reviewed literature from three databases including PubMed, EMBASE, and Cochrane Library (from 2000 to March 2019). Clinical studies from controlled trials for shunt operation were included in this analysis. A subgroup analysis was performed based on the patient's age, follow-up time and high-risk population. The fixed effect in RevMan 5.3 software (Cochrane Collaboration) was used for this meta-analysis. RESULTS: This study included 19 controlled clinical trials including 10105 operations. The analysis demonstrated that AISC could reduce the infection rate in shunt surgery compared to standard shunt catheter (non-AISC) from 8.13% to 4.09% (odds ratio [OR], 0.48; 95% confidence interval [CI], 0.40-0.58; p=0.01; I2=46%). Subgroup analysis of different age groups showed that AISC had significant antimicrobial effects in all three groups (adult, infant, and adolescent). Follow-up time analysis showed that AISC was effective in preventing early shunt infections (within 6 months after implant). AISC is more effective in high-risk population (OR, 0.24; 95% CI, 0.14-0.40; p=0.60; I2=0%) than in general patient population. CONCLUSION: The results of meta-analysis indicated that AISC is an effective method for reducing shunt infection. We recommend that AISC should be considered for use in infants and high-risk groups. For adult patients, the choice for AISC could be determined based on the treatment cost.

Influence of arm position change from adduction to abduction on intracavitary electrocardiogram.

PURPOSE: The aim of this study is to evaluate the influence of arm movements from adduction to abduction on intracavitary electrocardiogram and the position of a catheter tip. METHODS: Overall, 192 peripherally inserted central catheter lines were placed under intracavitary electrocardiogram guidance and 188 of them were enrolled in the study. The catheter was first placed at a time point corresponding to the peak P wave with the arm in adduction. The arm was then abducted to 90° without changing catheter insertion length. During the procedure, basal electrocardiogram, intracavitary electrocardiogram, and radiographs with the arm in adduction and abduction were recorded. Amplitude wave changes and catheter movements were measured on electrocardiogram records and radiographs, respectively. RESULTS: In 188 cases, the P wave displayed typical changes, and 97.8% (184/188) catheters were successfully placed correctly. At the peak P wave, the amplitude of the peak P wave was 8.64 times greater than that of the basal P wave, and the P/R ratio was 0.61. When the arm was abducted to 90°, the amplitude of the P wave dropped to 57% of its peak, P/R decreased from 0.61 to 0.34, and the catheter tip moved cephalad 1.00 and 0.77 vertebral body units in male and female patients, respectively. CONCLUSION: Peripherally inserted central catheter moves toward the heart when the arm position changes from abduction to adduction. Peripherally inserted central catheter tip placement at the peak P wave with patient's arm in adduction is accurate and can prevent the catheter from advancing too low. R wave can function as a reference for observing P wave changes during peripherally inserted central catheter placement.

Randomized multicenter study on long-term complications of peripherally inserted central catheters positioned by electrocardiographic technique.

BACKGROUND: The intracavitary electrocardiogram (IC-ECG) method has been used for the tip location of central venous access devices for the advantage of being safe, accurate and highly cost effective. However, long-term follow-up is rare. This randomized clinical trial aimed to evaluate the long-term complications of peripherally inserted central catheters (PICCs) positioned by the IC-ECG method. METHODS: We randomized 2250 patients who needed PICC placement to either a landmark length estimation supplemented by IC-ECG positioned group (ECG group) or the traditional landmark length estimation alone group (control group) in a 2:1 allocation. Post-procedural chest X-rays were applied to confirm tip position. Follow-up was performed monthly to six months. Standard statistics analyses were performed with the SAS 9.13 software, and p < 0.05 was considered significant. RESULTS: As evaluated by post-procedural chest X-ray, tip location in the ECG group had a first-attempt success (catheter tip located at optimal position) of 91.7% (95% confidence interval (CI): 90.3%-93.1%), significantly higher than 78.9% (95% CI: 76.0%-81.9%) observed in the control group (p < 0.001). At six-month follow-up, in the control group, frequency of total complications was 9.5%, including the exit site infection (4.0%), phlebitis (1.3%), deep venous thrombosis (1.5%), liquid extravasation (2.9%) and mechanical failure (1.9%). The IC-ECG group had significantly lower rates of complications (6.4%, p < 0.001), including the exit site infection (2.7%, p > 0.05), phlebitis (1.1%, p > 0.05), deep venous thrombosis (1.2%, p > 0.05), liquid extravasation (2.4%, p > 0.05) and mechanical failure (1.2%, p > 0.05). In the univariable logistic regression analysis, ECG method, other diseases and upper arms were the independent protective factors, and the number of adjustment procedures (n ≥ 2) were the independent risk factors of the complications. CONCLUSIONS: The intra-procedural tip location by IC-ECG is more safe and accurate than the traditional method of verifying tip location only post-procedurally, by chest X-ray.

Comparison of complications in cranioplasty with various materials: a systematic review and meta-analysis.

Objective: Meta-analysis to evaluate complications in the use of autogenous bone and bone substitutes and to compare bone substitutes, specifically HA, polyetheretherketone (PEEK) and titanium materials.Methods: Search of PubMed, Cochrane, Embase and Google scholar to identify all citations from 2010 to 2019 reporting complications regarding materials used in cranioplasty.Results: 20 of 2266 articles met the inclusion criteria, including a total of 2913 patients. The odds of overall complication were significantly higher in the autogenous bone group (n = 214/644 procedures, 33.2%) than the bone substitute groups (n = 116/436 procedures, 26.7%, CI 1.29-2.35, p < 0.05). In bone substitutes groups, there was no significant difference in overall complication rate between HA and Ti (OR, 1.2; 95% CI, 0.47-3.14, p = 0.69). PEEK has lower overall complication rates (OR, 0.51; 95% CI, 0.30-0.87, p = 0.01) and lower implant exposure rates (OR, 0.17; 95% CI, 0.06-0.53, p = 0.002) than Ti, but there was no significant difference in infection rates and postoperative hematoma rates.Conclusions: Cranioplasty is associated with high overall complication rates with the use of autologous bone grafts compared with bone substitutes. PEEK has a relatively low overall complication rates in substitutes groups, but still high infection rates and postoperative hematoma rates. Thus, autologous bone grafts should only be used selectively, and prospective long-term studies are needed to further refine a better material in cranioplasty.

Design biodegradable Zn alloys: Second phases and their significant influences on alloy properties.

Alloying combined with plastic deformation processing is widely used to improve mechanical properties of pure Zn. As-cast Zn and its alloys are brittle. Beside plastic deformation processing, no effective method has yet been found to eliminate the brittleness and even endow room temperature super-ductility. Second phase, induced by alloying, not only largely determines the ability of plastic deformation, but also influences strength, corrosion rate and cytotoxicity. Controlling second phase is important for designing biodegradable Zn alloys. In this review, knowledge related to second phases in biodegradable Zn alloys has been analyzed and summarized, including characteristics of binary phase diagrams, volume fraction of second phase in function of atomic percentage of an alloying element, and so on. Controversies about second phases in Zn-Li, Zn-Cu and Zn-Fe systems have been settled down, which benefits future studies. The effects of alloying elements and second phases on microstructure, strength, ductility, corrosion rate and cytotoxicity have been neatly summarized. Mg, Mn, Li, Cu and Ag are recommended as the major alloying elements, owing to their prominent beneficial effects on at least one of the above properties. In future, synergistic effects of these elements should be more thoroughly investigated. For other nutritional elements, such as Fe and Ca, refining second phase is a matter of vital concern.

Hemocompatibility of biodegradable Zn-0.8 wt% (Cu, Mn, Li) alloys.

Zinc alloys have been explored as potential materials for biodegradable vascular stents due to their tolerable corrosion rates and tunable mechanical properties. However, the performances of Zn alloys were not supported with enough toxicity or biological compatibility evaluation, particularly hemocompatibility for vascular scaffolding application. In this work, the hemocompatibility of three zinc alloys (Zn-0.8Cu, Zn-0.8Mn and Zn-0.8Li) was evaluated with 316 L stainless steel and pure zinc as controls. The hemolysis ratios of 316 L stainless steel, pure Zn, Zn-0.8Cu, Zn-0.8Mn and Zn-0.8Li were 0.38 ±â€¯0.08%, 1.04 ±â€¯0.21%, 0.47 ±â€¯0.21%, 0.57 ±â€¯0.14% and 0.52 ±â€¯0.22%, respectively, for direct contact method. Platelets aggregation on the 316 L stainless steel was observed, while the adhered platelets on the Zn alloys exhibited round shape with few pseudopodia spreading. The number of adhered platelets on the three zinc alloys (Zn-0.8Cu, Zn-0.8Mn and Zn-0.8Li) had no statistically difference compared with 316 L stainless steel, while significant fewer than the pure Zn group. None remarkable platelet activation, hematocyte aggregation, coagulation or complement activation was observed in any Zn alloy group. Furthermore, the Zn alloys prolonged prothrombin time and partial thromboplastin time, demonstrating a potential function of anticoagulation. The results demonstrated that Zn alloys presented in this work are indeed meeting the hemocompatible requirements of implant and showing the promise for perspective application as biodegradable stent.

Long-term in vivo study of biodegradable Zn-Cu stent: A 2-year implantation evaluation in porcine coronary artery.

In the present study, a novel biodegradable Zn-0.8Cu coronary artery stent was fabricated and implanted into porcine coronary arteries for up to 24 months. Micro-CT analysis showed that the implanted stent was able to maintain structural integrity after 6 months, while its disintegration occurred after 9 months of implantation. After 24 months of implantation, approximately 28 ±â€¯13 vol% of the stent remained. Optical coherence tomography and histological analysis showed that the endothelialization process could be completed within the first month after implantation, and no inflammation responses or thrombosis formation was observed within 24 months. Cross-section analysis indicated that the subsequent degradation products had been removed in the abluminal direction, guaranteeing that the strut could be replaced by normal tissue without the risk of contaminating the circulatory system, causing neither thrombosis nor inflammation response. The present work demonstrates that the Zn-0.8Cu stent has provided sufficient structural supporting and exhibited an appropriate degradation rate during 24 months of implantation without degradation product accumulation, thrombosis, or inflammation response. The results indicate that the Zn-0.8Cu coronary artery stent is promising for further clinical applications. STATEMENT OF SIGNIFICANCE: Although Zn and its alloys have been considered to be potential candidates of biodegradable metals for vascular stent use, by far, no Zn-based stent with appropriate medical device performance has been reported because of the low mechanical properties of zinc. The present work presents promising results of a Zn-Cu biodegradable vascular stent in porcine coronary arteries. The Zn-Cu stent fabricated in this work demonstrated adequate medical device performance both in vitro and in vivo and degraded at a proper rate without safety problems induced. Furthermore, large animal models have more cardiovascular similarities as humans. Results of this study may provide further information of the Zn-based stents for translational medicine research.

Safety and efficacy of leadless pacemaker retrieval.

BACKGROUND AND OBJECTIVES: The success rate of leadless cardiac pacemaker (LP) retrieval remains a major concern for this disruptive technology. The present paper performed a systematic review of the safety and feasibility of the retrieval of LPs. METHODS: Primary publications that performed LP retrieval were collected and included five animal experiments and two worldwide retrieval experiences in human. The procedural details, such as indication, days post implantation, extraction success rate, and complications, were described. The present paper analyzed factors affecting the retrieval and management of the nonfunctional devices. RESULTS: Retrieval animal models was possible at least up to 2.5 years post implantation, and data from humans suggest that removal of a device that was implanted longer (eg, 4 years and 9 months for Nanostim; 4 years for Micra) could be performed within a reasonable safety profile. The fixed mechanism, implant site, and encapsulation of the LP systems may affect the retrieval process. CONCLUSIONS: A high success rate in the relatively chronic retrieval of LPs was demonstrated, which promotes the extensive use of these devices in the treatment arrhythmia in the future.

Effects of Ag, Cu or Ca addition on microstructure and comprehensive properties of biodegradable Zn-0.8Mn alloy.

Zn-0.8Mn (in wt%) alloy with good ductility is used for design of novel Zn-0.8Mn-0.4x (x = Ag, Cu or Ca) alloys. Hot extrusion not only eliminates brittleness of the as-cast alloys but also significantly improves their strengths. Among them, Zn-0.8Mn-0.4Ca exhibits the highest strength, Zn-0.8Mn-0.4Ag exhibits the highest ductility, but Zn-0.8Mn-0.4Cu exhibits the best combination of strength and ductility. The minor addition of Ag, Cu or Ca accelerates alloy degradation in simulated body fluid. However, Cu addition much improves in vitro biocompatibility and endows antibacterial ability of Escherichia coli. Overall, Zn-0.8Mn-0.4Cu alloy has the best comprehensive properties.

Insertion of peripherally inserted central catheters with intracavitary electrocardiogram guidance: A randomized multicenter study in China.

INTRODUCTION: Ultrasound-guided venipuncture and tip location by intracavitary electrocardiogram have many advantages during the insertion of peripherally inserted central catheters, both in terms of safety and cost-effectiveness. Recently, a new tip-conductive peripherally inserted central catheters and new Doppler ultrasound device integrated with intracavitary electrocardiogram have been introduced into clinical practice in China. A randomized multicenter study (clinical trial no. NCT03230357) was performed to verify the feasibility and accuracy of intracavitary electrocardiogram, as performed with this new peripherally inserted central catheters and device. METHODS: Our study enrolled a total of 2250 adult patients in 10 different Chinese hospitals. The patients were randomly assigned to either the study group (intracavitary electrocardiogram) or the control group (anatomical landmark guidance) in a 2:1 allocation. Ultrasound was used in both groups for venipuncture and tip navigation. All patients underwent chest X-ray after the procedure to verify the position of the catheter tip. RESULTS: No insertion-related complications were reported in either group. In the study group, first-attempt successful tip location was 91.7% (95% confidence interval: 90.3%-93.1%), significantly higher than 78.9% (95% confidence interval: 76.0%-81.9%) observed in the control group (p < 0.001). As evaluated by post-procedural chest X-ray, tip location in the study group had a sensitivity of 99.3% (95% confidence interval: 98.8%-99.7%), significantly higher than 86.8% (95% confidence interval: 84.4%-89.2%) observed in the anatomical landmark group (p < 0.001). CONCLUSION: These results indicated that during peripherally inserted central catheters insertion in adult patients, tip location with intracavitary electrocardiogram guidance, as carried out by a new tip-conductive peripherally inserted central catheters and intracavitary electrocardiogram integrated ultrasound device, was more effective and more accurate than tip location using anatomical landmarks.

RanBPM contributes to TrkB signaling and regulates brain-derived neurotrophic factor-induced neuronal morphogenesis and survival.

Tropomyosin-related kinase (Trk) B is a receptor tyrosine kinase for brain-derived neurotrophic factor (BDNF) which plays a critical role in neuronal survival, differentiation and morphogenesis. Ran-binding protein in the microtubule-organizing center (RanBPM) is a cytosolic scaffold protein that has been shown to interact with protein-tyrosine kinase receptor MET, Axl/Sky, and TrkA in addition to the pan-neurotrophin receptor pan-neurotrophin receptor 75 kDa. In this study, we report RanBPM is a novel TrkB-interacting protein that contributes to BDNF-induced MAPK and Akt activation together with neuronal morphogenesis and survival. Over-expression of RanBPM in PC1210 cells (PC12 cells stably over-expressing TrkB) can significantly enhance BDNF-induced MAPK and Akt activation. Moreover, RanBPM can promote BDNF-induced hippocampal neuronal morphogenesis and enhance BDNF-mediated trophic effects after serum deprivation, while siRNA knock down of RanBPM in cells has the opposite effects. Together, these results suggest that RanBPM may modulate TrkB-mediated downstream signaling and biological functions.

Mechanism underlying activity-dependent insertion of TrkB into the neuronal surface.

Activity-dependent insertion of tyrosine kinase receptor type 2 (TrkB receptor) into the plasma membrane can explain, in part, the preferential effect of brain-derived neurotrophic factor (BDNF) on active neurons; however, the detailed cellular and molecular mechanisms underlying this process are still unclear. In our study, we developed a fluorescence ratiometric assay for surface TrkB receptors to investigate the mechanisms of recruitment of TrkB to the plasma membrane following chemical long-term potentiation (cLTP) induction. We found that, in hippocampal neurons, the effect of cLTP-induced TrkB surface-recruitment occurred predominantly on neurites with rapid kinetics (t(1/2) of approximately 2.3 minutes) and was dependent on an intact cytoskeleton structure. Mutagenesis studies revealed that the juxtamembrane domain of TrkB is necessary and sufficient for its activity-dependent insertion into the plasma membrane. Moreover, we found that the phosphorylation of TrkB receptor at the Ser478 site by cyclin-dependent kinase 5 (Cdk5) is essential for cLTP-induced TrkB insertion into the neuronal surface. Finally, the degree of cLTP-induced TrkB surface-recruitment is higher in postsynaptic regions, which provides a potential mechanism for rapid enhancement of postsynaptic sensitivity to incoming BDNF signaling. Our studies provide new insights regarding neuronal activity-dependent surface delivery of TrkB receptor, which will advance our understanding of the modulatory role of TrkB in synaptic plasticity.