Expert consensus on the clinical application of totally implantable venous access devices in the upper arm(2022 Edition)

With the widespread adoption of ultrasound guidance,Seldinger puncture techniques,and intracardiac electrical positioning technology for the placement of peripherally inserted central catheters in recent years,an increasing number of medical staff and patients now accept peripheral placement of totally implantable venous access devices(TIVADs)in the upper arm.This approach has the advantage of completely avoiding the risks of hemothorax,pneumothorax,and neck and chest scarring.Medical specialties presently engaged in this study in China include internal medicine,surgery,anesthesiology,and interventional departments.However,command over implantation techniques,treatment of complications,and proper use and maintenance of TIVAD remain uneven among different medical units.Moreover,currently,there are no established quality control standards for implantation techniques or specifications for handling complications.Thus,this expert consensus is proposed to improve the success rate of TIVAD implantation via the upper-arm approach,reduce complication rates,and ensure patient safety.This consensus elaborates on the technical indications and contraindications,procedures and technical points,treatment of complications,and the use and maintenance of upper-arm TIVAD,thus providing a practical reference for medical staff.

Prospective Assessment of Catheter Migration in Implanted Vascular Access Devices for Adjuvant Colorectal Cancer Chemotherapy

Background: Chemotherapy in colorectal cancer is usually administered as continuous infusion of 5-fluorouracil, often in combination with oxaliplatin or irinotecan. Targeted drugs are most efficient and tolerable in conjunction with continuous infusion dosing. Implanted venous access devices (VAD) are the prerequisite for continuous infusion administration. The reported catheter migration frequency with VAD is 0% - 3.5%. The purpose of this case-control study was to evaluate the predisposing factors of catheter migration. Methods: We inserted VADs in 88 radically operated colorectal cancer patients randomized to adjuvant 48-hour-infusion chemotherapy repeated every 14 days, altogether 12 times over 24 weeks. Three out of 88 patients (3.4%) had a symptomatic catheter migration from the superior caval vein into the internal jugular vein. The fourth case had chemotherapy for osteosarcoma. These 4 cases were compared with 12 controls from the same 88 patient study population, matched for age, sex, body mass index (BMI), physical activity level and right subclavian insertion site. Tip position, port model, complications, catheter length and material was studied. The post insertion catheter tip position in the chest X-ray was numbered from 1 (in subclavia) to 8 (in atrium). Results: The four cases, all male, had a median position of 3 (range 3 - 4) and controls 6 (range 4 - 8), P = 0.004, median difference 3 (CI95% 1 - 5). At notification of migration the patients had experienced discomfort in the neck region starting 5 to15 days before at strenuous upper extremities activity with Valsalva maneuvers. Conclusion: Optimal catheter tip position when sitting is in the right atrium or low in the superior vena cava to avoid migration. Patients with VADs should avoid strenuous activity with Valsalva maneuvers.

Intelligent Security Auditing Based on Access Control of Devices in Ad Hoc Network

Security in Ad Hoc network is an important issue under the opening circumstance of application service. Some protocols and models of security auditing have been proposed to ensure rationality of contracting strategy and operating regulation and used to identify abnormal operation. Model of security auditing based on access control of devices will be advanced to register sign of devices and property of event of access control and to audit those actions. In the end, the model is analyzed and simulated.

Clinical Course of Lung Cancer Patients with Subcutaneously Implanted Central Venous Access Device Ports from the Time of Receiving Chemotherapy to the Endpoint of Cancer

Background: As the prognosis of lung cancer (LC) patients improves, subcutaneously implanted central venous access device ports (CV-ports) have frequently been used for continuing chemotherapy (CC) or palliative care (PC). In this study, we examined the clinical course of LC patients with subcutaneously implanted CV-ports from the time of receiving chemotherapy to the endpoint of cancer. Materials and Methods: We retrospectively reviewed the clinical data and treatment history of LC patients with subcutaneously implanted CV-ports between June 2008 and November 2013 using clinical records and a pharmacy database. Results: Of the 132 LC patients with subcutaneously implanted CV-ports, 79 (59.8%) had CV-ports for CC (the CC group) and 53 (40.2%) had CV-ports for PC (the PC group). After CV-port implantation, LC patients in the CC group received a median of two regimens with a median of 6 cycles. The median survival time of patients in the CC and PC groups was 457 and 44 days, respectively. In the CC group, the median survival time of small cell and non-small cell LC patients was 342 (95% confidence interval, 235 - 627) and 563 (95% confidence interval, 368 - 728) days, respectively. Nine patients (6.8%) had their CV-ports removed due to complications. Forty (30.3%) of the 132 enrolled patients were referred for at-home PC. The at-home death rate observed among these 40 patients was 30.0% (N = 12). Conclusion: CV-ports may contribute to seamless oncological care.

Effect of Pulse and dc Formation on the Performance of One-Transistor and One-Resistor Resistance Random Access Memory Devices

We investigate the effect of the formation process under pulse and dc modes on the performance of one transistor and one resistor （1 T1R） resistance random access memory （RRAM） device. All the devices are operated under the same test conditions, except for the initial formation process with different modes. Based on the statistical results, the high resistance state （FIRS） under the dc forming mode shows a lower value with better distribution compared with that under the pulse mode. One of the possible reasons for such a phenomenon originates from different properties of conductive filament （CF） formed in the resistive switching layer under two different modes. For the dc forming mode, the formed filament is thought to be continuous, which is hard to be ruptured, resulting in a lower HRS. However, in the case of pulse forming, the filament is discontinuous where the transport mechanism is governed by hopping. The low resistance state （LRS） can be easily changed by removing a few trapping states from the conducting path. Hence, a higher FIRS is thus observed. However, the HRS resistance is highly dependent on the length of the gap opened. A slight variation of the gap length will cause wide dispersion of resistance.

A retrospective observational study on maintenance and complications of totally implantable venous access ports in 563 patients:Prolonged versus short flushing intervals

Objectives:To assess whether the extension of the flushing interval will increase risks of complications associated with totally implantable venous access port(TIVAP)in the off-treatment period.Methods:A retrospective single-center observational study was performed.Patients with a TIVAP in the off-treatment period that underwent regular flushing in our clinic were included.Data concerning patients and their TIVAPs were recorded.Patient baseline characteristics and TIVAP-related complications were analyzed.Continuous variables were analyzed by ANOVA or the Kruskal-Wallis H test.To compare the occurrence of TIVAP-related complications,the chi-square test was used;if needed,Fisher’s exact test was used.Results:Totally 607 patients were reviewed,and 563 patients were finally included.Thirteen complications were recorded,including 11 cases of catheter occlusion(1.95%),one case of port cannula rotation(0.18%),and one case of catheter tip malposition(0.18%).No device-related infection or venous thrombosis was recorded.Among these patients,the average flushing interval was 35.27±13.09 days.Patients were divided into three groups according to the flushing interval:every 28 days or less(Group 1,n=133);every 29-44 days(Group 2,n=350);and every 45 days or more(Group 3,n=80).No significant difference in catheter-related complications was found among the three groups(P>0.05).Conclusions:In the TIVAP off-treatment period,patients without any history of TIVAP-related complications during approximately one year can attempt to prolong the flushing interval to more than 4 weeks;we further suggest that 5-6 weeks may be an appropriate option for these patients.

Postpartum intrauterine device contraception: A review

AIM： To review the safety （infection, perforation） and efficacy （expulsion, continuation rates, pregnancy） of intrauterine device （IUD） insertion in the postpartum period. METHODS： MEDLINE, PubMed and Google Scholar were searched for randomized controlled trials and prospective cohort studies of IUD insertions at different times during the postpartum period. Time of insertion during the postpartum period was documented speci-fically, immediate post placenta period （within 10 min）, early post placenta period （10 min to 72 h）, and de-layed/interval period （greater than 6 wk）. Other study variables included mode of delivery, vaginal vs cesarean, manual vs use of ring forceps to insert the IUD. RESULTS： IUD insertion in the immediate postpartum （within 10 min of placental delivery）, early postpartum （10 min up to 72 h） and Interval/Delayed （6 wk onward） were found to be safe and effcacious. Expulsion rates were found to be highest in the immediate postpartum groups ranging from 14% to 27%. Immediate post placental insertion found to have expulsion rates that ranged from 3.6% to 16.2%. Expulsion rate was significantly higher after insertion following vaginal vs cesarean delivery. The rates of infection, perforation and unplanned pregnancy following postpartum IUD insertion are low. Method of insertion such as with ring forceps, by hand, or another placement method unique to the type of IUD did not show any signifcant difference in expulsion rates. Uterine perforations are highest in the delayed/interval IUD insertion groups.Breastfeeding duration and infant development are not affected by delayed/interval insertion of the non-hormonal （copper） IUD or the Levonorgestrel IUD. Timing of the Levonorgestrel IUD insertion may affect breastfeeding. CONCLUSION： IUD insertion is safe and efficacious during the immediate postpartum, early postpartum and delayed postpartum periods. Expulsion rates are highest after vaginal delivery and when inserted during the immediate postpartum period. IUD associated infection rates were not increased by insertion during the postpartum period over interval insertion rates. There is no evidence that breastfeeding is negatively affected by postpartum insertion of copper or hormone-secreting IUD. Although perforation rates were higher when inserted after lactation was initiated. Randomized controlled trials are needed to further elucidate the consequence of lactation on postpartum insertion. Despite the concerns regarding expulsion, perforation and breastfeeding, current evidence indicates that a favorable risk beneft ratio in support of postpartum IUD insertion. This may be particularly relevant for women for whom barriers exist in achieving desired pregnancy spacing.

A review in emergency central venous catheterization

Central venous catheterization is widely used in the emergency setting. This review aims to assess central venous catheterization from the perspectives of types of catheters, sites of insertion, and tech- niques. In emergency conditions, non-tunneled catheters are preferred because the technique for its insertion is not complicated and less time-consuming. The size of catheter depends on the purpose of catheterization. For example, a large bore catheter is needed for rapid infusion. The ideal catheterization site should bear fewer thromboses, lower infectious rate, and fewer mechanical complications. Thus the femoral vein should be avoided due to a high rate of colonization and thrombosis while the subclavian vein seems to exhibit fewer infectious complications compared with other sites. The ultrasound-guided technique increases the success rate of insertion while decreases the mechanical complications rate,