Refinement of vascular access port placement in nonhuman primates: complication rates and outcomes

Chronic vascular access is often needed in experimental animal studies, and vascular access ports (VAP) have been proposed as an alternative to conventional venipuncture. We previously reported on VAP implantation by using femoral venous cutdown (FVC) and tunneling. In an attempt to decrease the moderate complications associated with the FVC method, we developed the single-incision, peripheral-insertion (SIPI) method. In a retrospective evaluation, 92 FVC procedures were compared with 113 SIPI procedures in cynomolgus and rhesus macaques and baboons with as much as 2.5 y of follow-up. The rate of complications was significantly lower for the SIPI method than for the FVC method (19.4% versus 33.7%), particularly in regard to infectious complications (8.0% versus 27.3%, respectively). In addition, VAP patency for blood sampling and fluid infusion was significantly better for the SIPI method than for the FVC method, with 1-y patency rate of 83% and 46%, respectively, and 2-y patency rate of 74% and 36%, respectively. Additional advantages of the SIPI method include the simplified implantation of the VAP and access in the homecage without any sedation or restraint after appropriate training of animals to cooperate. We conclude that the SIPI method presents an opportunity for refinement and is superior to the FVC method for chronic vascular access.     

Risk factors associated with surgical site infection and the development of short-term complications in macaques undergoing indwelling vascular access port placement

BACKGROUND: Risk factors associated with surgical site infection (SSI) and the development of short-term complications in macaques undergoing vascular access port (VAP) placement are evaluated in this study. METHODS: Records from 80 macaques with VAPs were retrospectively reviewed. Logistic regression was used to identify factors associated with short-term post-operative complications. RESULTS: The primary outcome was SSI, which occurred in 21.6% (52.6% in the first 12 months vs. 13% thereafter) of procedures. SSI was associated with major secondary complications including VAP removal (11.4%), wound dehiscence (5.7%), and mechanical catheter occlusion (5.7%). In multivariate modeling, only surgical program progress was a statistically significant predictor of SSI, while animal compliance had a slightly protective effect. CONCLUSIONS: Vascular access ports have a moderate risk of complications, provided the surgical program optimizes best practices. Under complex experimental conditions, VAPs represent an important refinement, both improving animals' overall well-being and environment and reducing stress.     

经膝下途径导管直接溶栓治疗混合型下肢深静脉血栓形成

目的:评价经膝下(Below the Knee, BTK)途径导管直接溶栓(Catheter-Directed Thrombolysis, CDT)治疗混合型下肢深静脉血栓形成(Deep Vein Thrombosis, DVT)的安全性和有效性。方法:回顾性分析2013年1月至2017年10月于徐州市肿瘤医院介入科接受经BTK途径CDT治疗的38例急性混合型DVT患者临床资料,其中男性患者26例,女性患者12例,年龄54±11岁。结果:技术成功率为100%。经小隐静脉穿刺途径28例,小隐静脉切开途径4例,胫后静脉切开途径4例,胫后静脉穿刺途径2例。行CDT前,所有患者均接受临时可回收滤器置入,并于术后2周内取出。36名患者DVT血栓溶解成功(Ⅱ和Ⅲ级)。2名未获得血栓溶解成功的患者,从症状发生到CDT时间均大于10天。对13例患者(左侧10例,右侧3例)进行髂静脉球囊扩张和支架植入。围手术期出现切口渗血4例,切开部位麻木5例,没有新发肺栓塞和大出血发等主要并发症。平均随访时间为2年(1个月-4年),28例患者超过1.5年。2例患者由于未服用华法林而出现反复髂股DVT。随访期间通畅率和PTS率分别为81.6%(31/38)和31.6%(12/38)。结论:采用经BTK途径行CDT治疗混合型DVT是安全有效的,围手术期及随访期间结果满意,是一种值得推广的方法。     

Blood collection from the tail of a rat

Techniques for blood collection from the rat include puncture of the heart, retro-orbital plexus, jugular vein, saphenous vein, tail blood vessels, carotid artery, abdominal aorta, and vena cava. Most techniques (except saphenous vein and tail blood vessel puncture) require anesthesia. The following discussion focuses on two methods of blood collection - ventral tail artery puncture and dorsal or lateral tail vein puncture.     

A new method for localizing the landmark of axillary vein and its application

BackgroundAxillary vein puncture is a popular puncture site for pacemaker implantation. However, due to the lacking of body surface markers, the current puncture method is too complicated and affect the popularization and application of axillary vein puncture. Here, we performed a new body surface landmark to make the blind axillary vein puncture simple and easy.MethodsThe study population included 30 patients referred for pacemaker implantation using axillary vein puncture. Digital subtraction angiography (DSA) was used to determine the direction and the surface landmarks of the axillary vein. Medial cusp of thoracic triangle and the coracoid process were directly touched with fingers. The puncture point was about 1 cm below the coracoid, and the needle tip pointed to the medial cusp of thoracic triangle with the angle of 30–60°.ResultsThere was little variation in distribution of axillary vein. The body surface landmark of the junction of the axillary vein and the subclavian vein is on the medial cusp of thoracic triangle. In these 30 patients, blind axillary vein puncture was successful obtained in all patients. There was no pneumothorax and inadvertent arterial puncture. The pacemaker lead wire was placed smoothly. Moreover, the pacemaker pocket was ideally positioned when cut along the puncture point.ConclusionsBlind axillary vein access using the body surface landmark of the thoracic triangle is an effective method for pacemaker implantation and can obvious avoid the complications usually observed with the traditional subclavian vein approach.     

Vascular-access-port implantation for serial blood sampling in conscious swine

A method to simplify serial venous blood sampling in miniature pigs was developed. Jugular vein Vascular-Access-Ports (VAP) were implanted in four animals. The mean functional lifetime of these ports was 37.7 +/- 23.0 (S.D.) days with a range of 17 to 77 days. The VAP allowed easy serial blood sampling and intravenous drug administration. Use of these ports in animals restrained in a sling was simple and effective and caused no undue stress to the animal over a 6 to 8 hour experiment. The VAPs were implanted easily and required minimal maintenance. Subcutaneous location of the entire apparatus allowed for group housing of the pigs and decreased the susceptibility of postoperative infection and/or damage. Provided that proper maintenance and careful aseptic sampling techniques are used, the VAP is a relatively easy, safe and reliable alternative to conventional methods of serial blood sampling in swine.     

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。     

Change in Vascular Adhesion Protein‐1 and Metabolic Phenotypes after Vertical Banded Gastroplasty for Morbid Obesity

Objective: The association between circulating vascular adhesion protein‐1 (VAP‐1) and metabolic phenotypes has been shown to be inconsistent. The current study explored whether the changes in serum VAP‐1 levels correlate with the changes in metabolic phenotypes after weight reduction surgery. Research Methods and Procedures: Clinical characteristics and serum VAP‐1 levels in 20 morbidly obese subjects (mean BMI 38.84 kg/m²) were measured before and after vertical banded gastroplasty. Results: Before surgery, serum VAP‐1 levels correlated positively with fasting plasma glucose (γ = 0.56, p = 0.01) and negatively with insulin levels (γ = ?0.51, p = 0.021). After surgery, the changes in serum VAP‐1 levels were negatively correlated with the changes in waist circumference (γ = ?0.57, p = 0.011), diastolic blood pressure (DBP) (γ = ?0.56, p = 0.015), and mean arterial pressure (γ = ?0.46, p = 0.055). In multivariate regression, serum VAP‐1 levels were negatively correlated with waist circumference (β = ?2.36, p = 0.014) and DBP (β = ?3.02, p = 0.017) after adjusting for age and gender. The change in DBP was negatively correlated with the change in VAP‐1 levels after adjusting for age, gender, and steady‐state plasma glucose. Discussion: The results suggest that VAP‐1 levels are correlated with fasting glucose and insulin levels in morbidly obese subjects. After surgery, the changes in VAP‐1 levels were associated with changes in visceral adiposity and DBP. Serum VAP‐1 might modulate DBP independently from the changes in insulin resistance in morbidly obese people.     

Blood sampling from the retro-orbital plexus, the saphenous vein and the tail vein in rats: comparative effects on selected behavioural and blood variables

We compared the behaviours of rats, and measured various blood parameters, after three blood sampling techniques: orbital puncture while they were under diethyl-ether anaesthesia, blood collection by tail vein puncture under O2-N2O-halothane anaesthesia and puncture of the saphenous vein without anaesthesia. Twelve rats were subjected to the three treatments according to a Latin square design. After each treatment, the behaviour of the rats was automatically monitored using the so-called LABORAS method, which discriminates between grooming, locomotion and inactivity in rats. Based on excitation scores and urine production, it was found that induction of diethyl-ether anaesthesia combined with orbital puncture caused more distress than did the other two blood sampling techniques. The three techniques had no differential effects on the behaviours of grooming, locomotion and inactivity. Collecting 0.5 ml of blood by orbital puncture was +/-7 times faster than doing so by saphenous vein puncture and +/- 15 times faster than collecting blood by tail vein puncture while the rats were under O2-N2O-halothane anaesthesia. The levels of some haematological and plasma variables differed significantly between the three blood collection techniques. These observations may help to select the most appropriate technique of blood sampling with respect to anticipated discomfort in the animals.     

F-actin capping (CapZ) and other contractile saphenous vein smooth muscle proteins are altered by hemodynamic stress: a proteonomic approach

Increased force generation and smooth muscle remodeling follow the implantation of saphenous vein as an arterial bypass graft. Previously, we characterized and mapped 129 proteins in human saphenous vein medial smooth muscle using two-dimensional (2-D) PAGE and matrix-assisted laser desorption/ionization time-of-flight mass spectrometry. Here, we focus on actin filament remodeling in response to simulated arterial flow. Human saphenous vein was exposed to simulated venous or arterial flow for 90 min in vitro, and the contractile medial smooth muscle was dissected out and subjected to 2-D gel electrophoresis using a non-linear immobilized pH 3-10 gradient in the first dimension. Proteins were analyzed quantitatively using PDQuest 2-D software. The actin polymerization inhibitor cytochalasin B (1 microm) prevented increases in force generation after 90 min of simulated arterial flow. At this time point, there were several consistent changes in actin filament-associated protein expression (seven paired vein samples). The heat shock protein HSP27, identified as a three-spot charge train, showed a 1.6-fold increase in abundance (p = 0.01), but with reduced representation of the phosphorylated Ser(82) and Ser(15)Ser(82) isoforms (p = 0.018). The abundance of actin-capping protein alpha2 subunit CapZ had decreased 3-fold, p = 0.04. A 19-kDa proteolytic fragment of actin increased 2-fold, p = 0.04. For the four-spot charge train of gelsolin, there was reduced representation of the more acidic isoforms, p = 0.022. The abundance of other proteins associated with actin filaments, including cofilin and destrin, remained unchanged after arterial flow. Actin filament remodeling with differential expression and/or post-translational modification of proteins involved in capping the barbed end of actin filaments, HSP27 and CapZ, is an early response of contractile saphenous vein smooth muscle cells to hemodynamic stress. The observed changes would favor the generation of contractile stress fibers.     

Troglitazone has no effect on K(ATP) channel opener induced-relaxations in rat aorta and in human saphenous veins from patients with type 2 diabetes

Troglitazone, a thiazolidinedione derivative, is an oral antidiabetic agent that enhances insulin sensitivity in insulin-resistant states. K(ATP) channels, on the other hand, have important roles protecting cardiovascular system in ischemic and/or hypoxic states. They are also important in the control of vascular tone, and therefore of blood pressure. We tested whether troglitazone can directly affect vascular K(ATP) channel opener-induced relaxations in vitro. 1, 10 or 100 microM troglitazone incubations for 30 min did not alter cromakalim (a K(ATP) channel opener)--induced relaxations in endothelium-denuded aortas from rat, saphenous veins from type 2 diabetic and nondiabetic patients. In addition, we compared the sensitivity to cromakalim in diabetic saphenous veins with that of nondiabetic veins. The concentration-response curve for cromakalim was shifted to the right in diabetic vein. pD2 values for cromakalim were 6.85+/-0.08 vs. 6.61+/-0.04 (p<0.05) in nondiabetic (n:10) and diabetic (n:7) veins respectively. % maximum response of cromakalim was also significantly decreased by 24+/-3% in diabetic veins. However, responsiveness of veins to phenylephrine or sodium nitroprusside were similar in both groups. The results obtained may be clinically useful 1. suggesting that in ischaemic and/or hypoxic insults troglitazone may not worsen vascular dilatation, through K(ATP) channel, in diabetic patients who are more prone to these conditions than healthy people, 2. providing an evidence that diabetes causes an impaired dilatation of human saphenous vein through K(ATP) channels. This may partly be related with diabetes-induced vascular complications, such as vasospasm and even hypertension. Accordingly, since saphenous veins are used as conduit vessels in coronary by-pass graft surgery, the results also suggest that the defective dilatation through K(ATP) channels may play a role on the performance of saphenous vein grafts in type 2 diabetes.     

ASCENDING AORTIC ANEURYSM RESECTION EIGHT MONTHS AFTER TRIPLE CORONARY ARTERY BYPASS: CASE REPORT

This report involves the surgical treatment of a patient who underwent saphenous vein triple coronary artery bypass and subsequently developed an ascending aortic aneurysm and aortic insufficiency. Although the implantation of vascular structures into synthetic grafts is commonplace, this case is unique in that it involves the successful implantation of an aortic island containing the origin of the coronary arteries.     

Drawing blood from rats through the saphenous vein and by cardiac puncture

Drawing blood from rodents is necessary for a large number of both in vitro and in vivo studies. Sites of blood draws are numerous in rodents: retro-orbital sinus, jugular vein, maxillary vein, saphenous vein, heart. Each technique has its advantages and disadvantages, and some are not approved any more in some countries (e.g., retro-orbital draws in Holland). A discussion of different techniques for drawing blood are available (1-3). Here, we present two techniques for drawing blood from rats, each with its specific applications. Blood draw from the saphenous vein, provided it is done properly, induces minimal distress in animals and does not require anesthesia. This technique allows repeated draws of small amounts of blood, such as needed for pharmacokinetic studies (4,5), determining plasma chemistry, or blood counts (6). Cardiac puncture allows the collection of large amounts of blood from a single animal (up to 10 ml of blood can be drawn from a 150 g rat). This technique is therefore very useful as a terminal procedure when drawing blood from the saphenous would not provide a large enough sample. We use cardiac puncture when we need sufficient amounts of serum from a specific strain of rats to grow T lymphocyte lines in vitro (4-9).     

The geometry of unstented and stented pig common carotid artery bypass grafts

The long-term success of arterial bypass grafting with autologous saphenous veins is limited by neointimal hyperplasia (NIH), which seemingly develops preferentially at sites where hydrodynamic wall shear is low. Placement of a loose-fitting, porous stent around end-to-end, or end-to-side, autologous saphenous vein grafts on the porcine common carotid artery has been found significantly to reduce NIH, but the mechanism is unclear. In a preliminary study, we implanted autologous saphenous vein grafts bilaterally on the common carotid arteries of pigs, placing a stent around one graft and leaving the contralateral graft unstented. At sacrifice 1 month post implantation, the grafts were pressure fixed in situ and resin casts were made. Unstented graft geometry was highly irregular, with non-uniform dilatation, substantial axial lengthening, curvature, kinking, and possible long-pitch helical distortion. In contrast, stented grafts showed no major dilatation, lengthening or curvature, but there was commonly fine corrugation, occasional slight kinking or narrowing of segments, and possible long-pitch helical distortion. Axial growth of grafts against effectively tethered anastomoses could account for these changes. CFD studies are planned, using 3D MR reconstructions, on the effects of graft geometry on the flow. Abnormality of the flow could favour the development of vascular pathology, including NIH.     

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.     

Pneumothorax resulting from subclavian puncture: a complication of permanent pacemaker lead implantation

Pneumothorax is a mild complication during pacemaker lead implantation using the subclavian puncture technique. We report on five-year experience in 433 pacemaker lead implantation procedures in 379 patients. The cephalic vein route was solely used in twelve patients. Three procedures were performed over time in four patients and one patient needed four repetitive punctures for pacemaker lead implantation and replacement. Thus 421 punctures were carried out in 367 patients. Eleven case of pneumothorax were observed: in eight patients (1.9%) a partial pneumothorax occurred and in three patients (0.7%) the pneumothorax was nearly complete. In the latter patients a chest tube was inserted and hospital admission was prolonged for 3, 6 and 6 days, respectively. Old age with a corresponding abnormality in the form of chest deformation were predominantly found in the patients with this type of complication.     

A new device for the capture and transport of small nonhuman primates in scientific research

Conventional methods of capturing marmosets and other small nonhuman primates (NHPs) require prolonged physical contact between animals and their handlers. This causes NHPs to become stressed and exhausted and can put both animals and handlers at risk of injury or exposure to infectious diseases. The authors designed a self-contained device for the capture and transport of small NHPs. Food rewards encourage primates to enter the device independently, and handlers can then easily access the animals for routine veterinary or experimental procedures. Preliminary observations suggest that marmosets quickly become accustomed to the device and that the device causes less stress than capture by hand or by net.     

Leadless pacemaker implantation for pediatric patients through internal jugular vein approach: A case series of under 30 kg

BackgroundWe demonstrate a case series of 8 pediatric patients, all under 30 kg, who had leadless pacemaker implants via the internal jugular vein.MethodsA retrospective review of pediatric leadless pacing placement via the internal jugular vein at the University of Minnesota Masonic Children's Hospital and UC Davis Medical Center from 2018 through 2021 was performed. Rationales for pacing, demographics of patients, pacing thresholds, and longevity of devices were recorded.ResultsEight internal jugular pacemaker insertions were performed successfully in patients weighing between 10.9 kg and 29 kg. Five patients had Micra implantation via the right internal jugular vein, whereas 3 patients had insertion via the left internal jugular vein. No surgical cut-downs were performed. No venous complications occurred. Up to 3 years of follow-up were noted.ConclusionLeadless pacemaker implantation, via left or right internal jugular veins, is feasible without surgical cutdown in patients <30 kg     

一种动态检测小鼠微量血中T细胞受体重排删除环含量的方法

目的:通过检测比较外周血(颈动脉大量采血和微量隐静脉采血)、胸腺组织和脾脏组织等不同成分或组织中T细胞受体重排删除环(T cell receptor rearrangement excision circles,TREC)的含量,并建立一种通过微量外周血PCR预扩增的方法,评估胸腺输出功能。方法:采用C57BL/6小鼠作为实验对象,分成幼年组(5周龄,n=10)和成年组(15周龄,n=10)。经过隐静脉采血及颈动脉采血后处死小鼠,取小鼠胸腺器官和脾脏器官,提取基因组DNA(g DNA),隐静脉微量血g DNA通过PCR预扩增,提纯后再和颈动脉血、胸腺组织和脾脏组织g DNA一起进行实时定量PCR,分析各组织成分TREC的表达水平及差别。结果:幼年组胸腺组织及外周血中TREC的含量比成年组高,且二者趋势基本一致;而脾脏组织结果与其相反;幼年组小鼠胸腺组织中TREC的含量比脾脏组织中高,成年组小鼠结果与之相反;微量外周血经过预扩增后再进行实时定量PCR的结果与直接定量PCR结果一致,且更高效。结论:研究提供了一种新型高效的动态检测T细胞受体重排删除环和检测胸腺输出功能的方法。     

超声定位穿静脉结扎对下肢静脉性溃疡术后愈合影响的临床研究

目的:观察下肢静脉性溃疡患者穿静脉功能不全情况,探讨超声定位下肢穿静脉结扎对下肢静脉性溃疡术后疗效的影响。方法:40例大隐静脉曲张患者随机分成两组:A组采用大隐静脉高位结扎、静脉腔内微波射频闭合术及超声定位穿静脉结扎治疗,B组采用大隐静脉高位结扎和静脉腔内微波射频闭合术治疗。观察两组患者治疗后静脉性溃疡的愈合时间、复发率及瓣膜功能不全穿静脉数量部位,并比较两组患者临床预后评分。结果:术前两组瓣膜功能不全穿静脉数量分别是47条和44条,两组比较差异无统计学意义(P=0.5520)。术后两组愈合时间分别是(7.5±4.389)周和(11.6±6.489)周,两组比较差异具有统计学意义(P=0.048)。两组临床预后评分分别为(2.3±0.6)分和(1.1±1.5)分,两组比较差异具有统计学意义(P=0.042)。结论:多普勒超声可有效检测定位瓣膜功能不全的下肢穿静脉,在超声定位下行大隐静脉高位结扎、静脉腔内微波射频闭合术联合穿静脉结扎治疗下肢静脉性溃疡的疗效优于穿静脉不结扎。