Modified procedure for implantation of subcutaneous central venous access devices in macaques (Macaca mulatta)

A nonhuman primate model comprising adult male rhesus monkeys (Macaca mulatta) with chronically indwelling subcutaneous central venous access devices provides a unique opportunity to determine plasma pharmacokinetics of new drugs such as anticancer and anti- retroviral agents. The central venous access we use is a low-profile, single-septum, titanium port that is attached to a radiopaque, indwelling catheter; the catheter is implanted in an internal jugular vein. A common complication following placement of the venous access device was migration of the catheter tip. We therefore modified the standard procedure by cutting the silicone catheter and introducing the rigid connector to secure the catheter to the vessel at the insertion site (approximately 9 to 13 cm from the distal end of the catheter). Prior to the use of the connector, three of five catheters migrated within 4 weeks after placement. In contrast, all 13 internal jugular catheters with connectors have remained patent without migration of the catheter tip. Therefore, incorporation of the catheter connector appears to have eliminated the problem of catheter migration.     

Chronic silastic central venous catheterization for induction, maintenance and support of persistent granulocytopenia in rabbits

In order to investigate new approaches in diagnosis, prevention and treatment of infectious complicating chemotherapy-induced granulocytopenia, we developed and prospectively evaluated a method of chronic central venous catheterization for the induction, maintenance and support of persistent granulocytopenia in rabbits. The method entails a central venous silastic catheter with a subcutaneous tunnel and a heparin lock device for repeated non-traumatic sampling of blood and administration of medications. During the course of 10 months, 226 rabbits were studied. Mean duration of catheter placement was 27 days, 17 of which were spent in granulocytopenia. Two-way flow was sustained throughout the duration of placement in 205 rabbits (91%) and for 5,845 (95%) of a total 6,163 catheter-days. All but two catheters could be flushed throughout the duration of their placement. Postoperative infectious complications related to catheter insertion developed in less than 1% of the rabbits. This method of chronic catheterization safely provides long-term venous access for studies requiring frequent venous access, including the painless induction, maintenance, and support of chronic granulocytopenia in rabbits.     

Ultrasonic locating devices for central venous cannulation: meta-analysis

Objectives To assess the evidence for the clinical effectiveness of ultrasound guided central venous cannulation.Data sources 15 electronic bibliographic databases, covering biomedical, science, social science, health economics, and grey literature.Design Systematic review and meta-analysis of randomised controlled trials.Populations Patients scheduled for central venous access.Intervention reviewed Guidance using real time two dimensional ultrasonography or Doppler needles and probes compared with the anatomical landmark method of cannulation.Data extraction Risk of failed catheter placement (primary outcome), risk of complications from placement, risk of failure on first attempt at placement, number of attempts to successful catheterisation, and time (seconds) to successful catheterisation.Data synthesis 18 trials (1646 participants) were identified. Compared with the landmark method, real time two dimensional ultrasound guidance for cannulating the internal jugular vein in adults was associated with a significantly lower failure rate both overall (relative risk 0.14, 95% confidence interval 0.06 to 0.33) and on the first attempt (0.59, 0.39 to 0.88). Limited evidence favoured two dimensional ultrasound guidance for subclavian vein and femoral vein procedures in adults (0.14, 0.04 to 0.57 and 0.29, 0.07 to 1.21, respectively). Three studies in infants confirmed a higher success rate with two dimensional ultrasonography for internal jugular procedures (0.15, 0.03 to 0.64). Doppler guided cannulation of the internal jugular vein in adults was more successful than the landmark method (0.39, 0.17 to 0.92), but the landmark method was more successful for subclavian vein procedures (1.48, 1.03 to 2.14). No significant difference was found between these techniques for cannulation of the internal jugular vein in infants. An indirect comparison of relative risks suggested that two dimensional ultrasonography would be more successful than Doppler guidance for subclavian vein procedures in adults (0.09, 0.02 to 0.38).Conclusions Evidence supports the use of two dimensional ultrasonography for central venous cannulation.     

Operating management of central venous hypertension complicating upper extremity dialysis access

Aim: To evaluate the importance of surgical bypass between the terminal part of functional arteriovenous shunt (av) for hemodialysis on upper extremity and inner jugular vein in axillosubclavian venous segment obstruction associated with central venous hypertension. Method: Retrospective assessment of surgical bypass between central segments of av fistula and ipsilateral/contralateral inner jugular vein using ePTFE graft in 17 patients over a 20 year period (1987-2006). Results: The surgical procedure was not associated with intra- or post-operative complications. Primary cumulative bypass and av fistula function persisted for 26 months on average. Conclusion: An accurate bypass to salvage the functional dialysis access associated with central venous hypertension requires careful decision based on clinical and radiological examination. The bypass procedure is beneficial where endovascular treatment is not indicated. Clinical and radiological bypass monitoring is crucial.     

Peripherally inserted central venous catheters. Low-risk alternatives for ongoing venous access.

We prospectively evaluated the use of peripherally inserted central venous catheters to provide ongoing venous access in general medical and surgical patients in a Department of Veterans Affairs medical center. Between 1985 and 1988 trained nurses successfully inserted 393 catheters in 460 suitable patients (an 85.4% success rate). Correct catheter tip placement in the superior vena cava was documented in 359 of the 393 (91.3%) catheter insertions, but an additional 30 catheters were in a position deemed adequate for the intended use. The mean duration of catheter use was 27.6 +/- 5.2 (1 standard deviation) days (median 20 days, range 1 to 370 days). A total of 65 patients left the hospital with catheters in place, with the mean length of catheter use at home being 36.2 +/- 6.0 days (range 2 to 266). In all, 79% of the catheters were in use until the successful completion of therapy or patient death; catheter-related complications led to premature catheter removal in the remaining 21%. Catheter-related complications included bland phlebitis (8.2%), occlusion (8.2%), local infection (3.6%), bacteremia or fungemia (2.1%), mechanical failure or rupture (2.6%), venous thrombosis (0.7%), and other (3.3%). One patient required vein excision for the management of suppurative phlebitis, but no deaths were attributed to catheter use. This study illustrates the use and safety of peripherally inserted central venous catheters to provide reliable vascular access over prolonged periods in an elderly veteran population. At our facility, percutaneous central venous catheters and surgically implanted (Hickman or Broviac) catheters are now reserved for use in patients in whom peripherally inserted catheters cannot be placed.     

Complications of central venous catheterization from an anatomical point of view

For access to the central venous system numerous percutaneous methods and approaches exist. Questions are often raised concerning which approach is the safest. In 18 human cadavers, we punctured the internal jugular vein via an anterior and posterior approach and the subclavian vein via an infraclavicular route to determine which of these approaches is better with respect to success rate and frequency of puncture complications. The position of the needles was assessed by dissection. Successful venipunctures were achieved in 81% by the posterior approach, as opposed to 58% by the anterior approach and the infraclavicular route. The lowest frequency of complications was attained by the posterior approach (17%) too, whereas the anterior approach (33%) and the subclavian route (25%) had higher complication rates. The main complication of posterior and anterior approaches was inadvertent arterial puncture (9 vs. 19%). At the subclavian approach puncture of a 'wrong' vein was frequent (14%), and the complications included a case of pleura lesion. In conclusion the posterior approach to the internal jugular vein is superior to the other investigated approaches, and therefore, it can reasonably be proposed as a usual route for the insertion of a central venous catheter.     

Central venous catheters for chemotherapy of solid tumors--our results in the last 5 years

Central venous catheters provide an easy access for intravenous medications. Having a central line in place will relieve a child from the discomfort and danger of multiple regular intravenous lines for chemotherapy. The use of indwelling central venous catheters has become commonplace in the management of children undergoing oncological treatment. There are two types of central lines commonly used. There are Broviac catheters and Port-A-Cath (PAC) catheters. In the last 5 years we inserted 194 catheters in 175 children. We inserted 121 Broviac catheters and 73 PAC catheters. During the follow up of 39382 catheter days 44 complications were observed. In Broviac group the median follow up was 155 days and in PAC group was 230 days. We observed differences in the incidence between two devices. In Broviac group infections were more frequent and in PAC group other complications were more frequent than infections.     

Randomized Clinical Trial Comparing Ultrasound-Guided Procedure with the Seldinger’s Technique for Placement of Implantable Venous Ports

The aim of this randomized controlled study was to compare ultrasound-guided procedure with the Seldinger’s technique for placement of implantable venous ports. A total of 214 patients were randomized to receive TIAP placement by either ultrasound-guided procedure or the Seldinger’s technique. Complications and pain perception were compared between these two groups. No severe perioperative or periinterventional complication occurred. Significantly (P < 0.05) lower pain perception was observed in the ultrasound-guided group. Seldinger’s technique group showed higher rate in incidence of early and late complications including catheter dislocation, catheter occlusion, venous thrombosis, fever of unknown origin, skin necrosis, and sepsis. In conclusion, both techniques, the TIAP implantation via ultrasound-guided jugular vein puncture and via Seldinger’s technique subclavian vein puncture, are feasible and safe. Regarding intrainterventional pain perception and implantation-related complications, the jugular vein puncture under ultrasound guidance seems to be advantageous.     

彩色超声与盲探穿刺右颈内静脉并发症比较

目的比较彩色超声引导与盲探穿刺右侧颈内静脉置管术的并发症情况。方法将我院拟择期(在腹腔镜下)行结直肠肿瘤切除术的患者100例,ASA分级Ⅰ~Ⅲ级,年龄23~81岁,体重32~81kg。采用抛硬币法将患者随机分为彩色超声组(C)和盲探穿刺组(M)各50例。记录两组病人黑色细针试穿中静脉时次数、薄壁蓝空针穿刺中静脉时次数、穿刺点的数目、导管置入失败的次数,并记录病人由于穿刺引起的机械并发症及术后留置导管并发症情况。结果两组患者均未见明显机械并发症,且两组比较无统计学意义;两组无误穿动脉、血气胸及心律失常或心脏损伤的情况。结论彩色超声引导下行右颈内静脉穿刺成功率较盲探穿刺高,盲探穿刺刺破颈内静脉后壁概率较彩色多普勒超声引导下穿刺组高,其余机械并发症及留置中心静脉导管并发症比较无统计学意义。     

Intrapulmonal dislocation of a totally implantable venous access device

BACKGROUND: Totally implantable venous access devices are widely used for infusion of chemotherapy or parenteral nutrition. Device associated complications include technical operative problems, infections, paravasal infusions and catheter or punction chamber dislocation. CASE PRESENTATION: We present the case of a 49-year-old patient with the rare complication of a intrapulmonal catheter dislocation of a totally implantable venous access system. Treosulfane for chemotherapy of metastatic breast cancer was infused via the catheter causing instant coughing and dyspnoea which lead to the diagnosis of catheter dislocation. The intrapulmonal part of the catheter was removed under thoracoscopic control without further complications. CONCLUSION: Intrapulmonal catheter dislocation is a rare complication of a totally implantable venous access device which can not be avoided by any prophylactic measures. Therefore, the infusion system should be tested before each use and each new symptom, even when not obviously related to the catheter should be carefully documented and evaluated by expert physicians to avoid severe catheter-associated complications.     

A novel alternative placement site and technique for totally implantable vascular access ports in non‐human primates

Background Two novel approaches to implanting a central venous catheter port in non‐human primates (NHPs) using peripheral insertion are presented and compared. Methods Sixty vascular access port (VAP) implants were attempted in 52 NHPs by saphenous vein puncture (n = 20) or saphenous vein cutdown (n = 40). Results Fifty eight procedures were successful. Eighteen of 20 VAPs were successfully placed using saphenous vein puncture, and 40 of 40 using saphenous vein cutdown. There were no significant differences between procedures. Mean implantation times were similar between groups. At explant or study endpoint, all 58 VAPs were patent. Conclusions Vascular access port implantation by saphenous vein puncture or saphenous vein cutdown is safe and effective in NHPs. It is less invasive than conventional procedures, has fewer complications, provides outstanding patency, and reduces surgery time. Furthermore, it allows for cooperative in‐homecage VAP use, minimizing handling stress. We recommend these refined methods for long‐term vascular access in NHPs.     

Gender differences in vascular access in hemodialysis patients in the United States: Developing strategies for improving access outcome

Background: Patients undergoing chronic hemodialysis (HD) require placement of permanent vascular access with the creation of an arteriovenous fistula (AVF), an arteriovenous prosthetic graft (AVG), or a tunneled central venous catheter. AVFs provide greater long-term patency, fewer complications, and lower infection rates than do either AVGs or catheters. Despite these advantages, women continue to be underrepresented among AVF patients, possibly because of concerns about smaller vascular diameters and higher rates of early primary fistula failure in female HD patients. The numerous clinical benefits of AVF suggest that a greater effort should be made to promote AVF placement in women.Objective: This review analyzes risk factors for AVF failure in women and describes clinical strategies to improve AVF utilization and success for female HD patients.Methods: English-language publications were identified through a MEDLINE database search from January 1997 to March 2007, using the search terms arteriovenous fistula, vascular access, hemodialysis, female, and gender. Reference lists of identified articles were also reviewed.Results: There are significant benefits to using AVFs instead of AVGs or catheters in HD patients: greater long-term fistula patency, superior flow rates, and fewer complications. Vascular anatomical differences between the sexes contribute to the underutilization of AVF in women. AVF placement rates can be improved if patients and staff are adequately educated and provided with the tools to facilitate AVF placement. Noninvasive preoperative screening is important to identify superior access sites in women. Intraoperative monitoring of blood flow is a reliable predictor of early radiocephalic AVF patency. Routine postoperative vascular monitoring may improve overall success with AVF, and exercise may improve vascular diameter and may be even more beneficial for women, who may have smaller preoperative veins.Conclusions: Concerns about smaller vascular diameters and reports of higher failure rates in women may prevent nephrologists and surgeons from considering AVF for female HD patients. The numerous advantages associated with AVF suggest that a greater effort should be made to increase its utilization in women. With appropriate motivation, care, and diligence by treating clinicians, the success of AVFs in women can approach the good results typically expected in men.     

Iatrogenic chorioretinal venous anastomosis in the treatment of central retinal vein occlusion

This paper discusses the clinical application of an iatrogenic chorioretinal venous anastomosis for experimental treatment of non-ischemic central retinal vein occlusions (CRVO). The creation of an iatrogenic chorioretinal venous anastomosis offers a potential means of by-passing the obstructed central retinal vein and allowing venous blood to exit the retinal circulation through the choroid. A successful anastomosis may allow improved venous drainage and faster resolution of macular edema. This procedure may also prevent the conversion of a non-ischemic CRVO to the ischemic type. The natural history of a CRVO, the procedure for anastomosis creation, the patients most likely to benefit, and complications of chorioretinal anastomosis are discussed.     

Incidence of deep vein thrombosis related to peripherally inserted central catheters in children and adolescents

Background

Peripherally inserted central catheters (PICC) in children and adolescents are being used with increasing frequency. We sought to determine the incidence and characterize risk factors of deep vein thrombosis associated with peripherally inserted central catheters in a pediatric population.

Methods

We conducted a prospective study involving consecutive patients referred to the radiology department of a tertiary care university-affiliated hospital for insertion of a peripherally inserted central catheter. We included patients aged 18 years or less who weighed more than 2.5 kg and had a peripherally inserted central catheter successfully inserted in his or her arm between June 2004 and November 2005. The primary outcome was the occurrence of partial or complete deep vein thrombosis evaluated by clinical examination, ultrasonography and venous angiography.

Results

A total of 214 patients (101 girls, 113 boys) were included in the study. Partial or complete deep vein thrombosis occurred in 20 patients, for an incidence of 93.5 per 1000 patients and 3.85 per 1000 catheter-days. Only 1 of the cases was symptomatic. In the univariable analyses, the only variable significantly associated with deep vein thrombosis was the presence of factor II mutation G20210A (odds ratio 7.08, 95% confidence interval 1.11–45.15, p = 0.04), a genetic mutation that increases the risk of a blood clot and that was present in 5 (2.3%) of the 214 patients.

Interpretation

The incidence of deep vein thrombosis related to peripherally inserted central catheters in our study was lower than the incidence related to centrally inserted venous catheters described in the pediatric literature (11%–50%).Most data available in the adult and pediatric literature on the incidence of deep vein thrombosis concern centrally inserted venous catheters, which are inserted directly in a central vein (jugular, subclavian or femoral). Typical symptoms of deep vein thrombosis are frequently absent in children and adolescents. Although the diagnosis of deep vein thrombosis is more reliable when based on Doppler ultrasonography or venous angiography,^1–10 in most studies these diagnostic tests were performed only when patients presented clinical symptoms of deep vein thrombosis or catheter dysfunction. In studies focused on the pediatric population, the frequency of deep vein thrombosis related to centrally inserted venous catheters has varied from 11% to 50%.^1,5,6,8,11In the past 10 years, peripherally inserted central catheters (PICC) have been used with increasing frequency in children and adolescents. The catheter is inserted percutaneously via a peripheral vein, with its tip residing in the superior vena cava. The main indications for this type of catheter insertion are difficult venous access, home intravenous antibiotic therapy, administration of chemotherapy or other hyperosmolar solution and long-term parenteral nutrition. The risk of deep vein thrombosis related to peripherally inserted central catheters could be greater among children and adolescents than among adults, given the size of the veins. Several studies have published complications related to peripherally inserted central catheters,^12–20 but few focused on the pediatric population.^13–21 Furthermore, in all of these studies, screening for deep vein thrombosis was not systematic. The real incidence of deep vein thrombosis related to peripherally inserted central catheters and their complications in the pediatric population are therefore unknown. We conducted this study to determine the incidence and characterize the risk factors of deep vein thrombosis related to peripherally inserted central catheters in children and adolescents in our institution.     

Development of the pulmonary vein and the systemic venous sinus: an interactive 3D overview

Knowledge of the normal formation of the heart is crucial for the understanding of cardiac pathologies and congenital malformations. The understanding of early cardiac development, however, is complicated because it is inseparably associated with other developmental processes such as embryonic folding, formation of the coelomic cavity, and vascular development. Because of this, it is necessary to integrate morphological and experimental analyses. Morphological insights, however, are limited by the difficulty in communication of complex 3D-processes. Most controversies, in consequence, result from differences in interpretation, rather than observation. An example of such a continuing debate is the development of the pulmonary vein and the systemic venous sinus, or "sinus venosus". To facilitate understanding, we present a 3D study of the developing venous pole in the chicken embryo, showing our results in a novel interactive fashion, which permits the reader to form an independent opinion. We clarify how the pulmonary vein separates from a greater vascular plexus within the splanchnic mesoderm. The systemic venous sinus, in contrast, develops at the junction between the splanchnic and somatic mesoderm. We discuss our model with respect to normal formation of the heart, congenital cardiac malformations, and the phylogeny of the venous tributaries.     

Chronic central vein catheterization for intraoperative and long-term venous access in swine

Chronic venous access and repeated blood sampling for research purposes in large swine ideally should be possible without sedation, restraint or direct venipuncture of deep vessels. An operative technique of cranial vena cava catheterization and chronic catheter maintenance methods are described which were used successfully in the placement of 11 silicone rubber catheters in 10 animals. All were used for repeated blood sampling, as well as intraoperative infusion of medications and large fluid volumes. Long term patency was excellent with 10 catheters patent at the end of the study interval, up to 14 weeks after insertion. Serial blood sampling was accomplished easily without restraint. Catheter damage, infection or malfunction was rare. Proper maintenance and careful aseptic blood sampling render the cranial vena cava catheter a safe and reliable alternative to direct venipuncture in swine.     

Hydrothorax after Central Venous Catheterization

Three patients are described who developed hydrothorax as a complication of central venous catheterization. Respiratory distress associated with physical signs of fluid in the chest should arouse suspicion that the venous catheter has perforated the wall of the vein.The complications of central venous catheterization are reviewed and three cases of hydrothorax are presented. Comments on the prevention of these complications, their diagnosis and treatment if they occur, are made.     

Another method to prevent venous thrombosis in microsurgery: an in situ venous catheter

Free-flap failure is in the order of 4 to 10 percent. Heparin is more effective at preventing venous thrombosis than arterial thrombosis. This study was undertaken to investigate the efficacy of delivering heparin at a high dose locally but low dose systemically (heparin infusion via a catheter placed proximal to the venous anastomosis) to prevent venous thrombosis in microsurgery. A model of venous thrombosis was first established by a venous inversion graft in the rat femoral vein (this was performed in seven animals and resulted in 100 percent thrombosis). Saline and heparin were delivered proximal to the inverted vein graft to assess the effect of each in preventing venous thrombosis. Flow/patency distal to the inverted vein graft was assessed by observation under the microscope, the milk test, and rate of flow (flowmeter). Saline infused via a catheter proximal to the venous inversion graft resulted in 100 percent thrombosis in 10 animals. Heparin (100 U/ml at 2 to 3 ml/hour) infused through a catheter for 2 hours proximal to the anastomosis resulted in flow in all 10 animals during the infusion. Blood was also taken before beginning the procedure (control) and after the heparin infusion distal to the anastomosis (local partial thromboplastin time) as well as in the contralateral femoral vein (systemic). The control for all animals that received heparin was <3 minutes. The systemic partial thromboplastin time after heparin infusion was <3 minutes in seven animals, 3.3 minutes in two animals, and >7 minutes in one animal. The local partial thromboplastin time distal to the inverted vein graft was >10 minutes in nine animals and 3.7 minutes in one animal. The study also had a clinical component, in which a catheter was placed in a vein of the free flap, and heparin was infused over 5 days. This technique has been used in 83 consecutive free flaps. In three recent free flaps performed on the limbs, the local partial thromboplastin time (close to the anastomosis) was raised but the systemic time was normal. This technique offers a method in preventing venous thrombosis in microsurgery. It is simple to implement and is not associated with the systemic complications of heparin.     

Secondary amyloidosis in rhesus monkeys with chronic indwelling venous catheters

Secondary amyloidosis was diagnosed in five Rhesus monkeys with chronic indwelling venous catheters. Diagnostic enzymology demonstrated normal serum alanine aminotransferase concentration and consistently elevated serum alkaline phosphatase. Serum protein electrophoresis on all five animals showed a typical pattern of decreased albumin and increased gamma globulin. Necropsy or biopsy specimens verified the presence of amyloid deposits in all animals. The diagnostic usefulness of clinical enzymology, serum protein electrophoresis and liver biopsy were demonstrated and the importance of considering amyloidosis as a differential diagnosis in monkeys with indwelling vascular catheters is emphasized.     

Hepatic potassium movements induced by sympathomimetic amines before and after adrenergic blockade.

The hepatic K+-mobilizing effects of phenylephrine and isoproterenol were studied in dogs equipped with chronic indwelling portal vein catheters. Animals anesthetized with sodium pentobarbital, received intraportal injections of these sympathomimetic amines, alone or in combination, before and after alpha, or beta, or combined adrenergic blockade. Hepatic K+ movements were assessed by measuring systemic arterial and hepatic venous K+ levels. It was concluded that adrenergic blockade exerted no significant influence on the ability of these agents to provoke the initial release and subsequent uptake of K+ by the liver.