Intraluminal Drug Delivery to the Mouse Arteriovenous Fistula Endothelium

Delivery of therapeutic agents to enhance arteriovenous fistula (AVF) maturation can be administered either via intraluminal or external routes. The simple murine AVF model was combined with intraluminal administration of drug solution to the venous endothelium at the same time as fistula creation. Technical aspects of this model are discussed. Under general anesthesia, an abdominal incision is made and the aorta and inferior vena cava (IVC) are exposed. The infra-renal aorta and IVC are dissected for clamping. After proximal and distal clamping, the puncture site is exposed and a 25 G needle is used to puncture both walls of the aorta and into the IVC. Immediately after the puncture, a reporter gene-expressing viral vector was infused in the IVC via the same needle, followed by 15 min of incubation. The intraluminal administration method enabled more robust viral gene delivery to the venous endothelium compared to administration by the external route. This novel method of delivery will facilitate studies that explore the role of the endothelium in AVF maturation and enable intraluminal drug delivery at the time of surgical operation.     

Inferior vena caval hemodynamics quantified in vivo at rest and during cycling exercise using magnetic resonance imaging

Compared with the abdominal aorta, the hemodynamic environment in the inferior vena cava (IVC) is not well described. With the use of cine phase-contrast magnetic resonance imaging (MRI) and a custom MRI-compatible cycle in an open magnet, we quantified mean blood flow rate, wall shear stress, and cross-sectional lumen area in 11 young normal subjects at the supraceliac and infrarenal levels of the aorta and IVC at rest and during dynamic cycling exercise. Similar to the aorta, the IVC experienced significant increases in blood flow and wall shear stress as a result of exercise, with greater increases in the infrarenal level compared with the supraceliac level. At the infrarenal level during resting conditions, the IVC experienced higher mean flow rate than the aorta (1.2 +/- 0.5 vs. 0.9 +/- 0.4 l/min, P < 0.01) and higher mean wall shear stress than the aorta (2.0 +/- 0.6 vs. 1.3 +/- 0.6 dyn/cm(2), P < 0.005). During exercise, wall shear stress remained higher in the IVC compared with the aorta, although not significantly. It was also observed that, whereas the aorta tapers inferiorly, the IVC tapers superiorly from the infrarenal to the supraceliac location. The hemodynamic and anatomic data of the IVC acquired in this study add to our understanding of the venous circulation and may be useful in a clinical setting.     

DIRECT LEFT VENTRICULAR PUNCTURE

Left ventricular puncture with ventriculography was carried out in 150 cases over the past four years as an adjunct to cardiac catheterization. It proved to be a safe method of obtaining data on abnormalities of the heart. In addition, it permitted excellent visualization of the thoracic aorta and brachiocephalic vessels.Inserting the needle at the subxiphoid and directing it through the apex of the right ventricle, into the septum and then the left ventricle lessened the hazard of injury to the left coronary artery or of entering the pleural cavity that is associated with direct apical puncture. Complications and failures were few.     

Primary leiomyosarcoma of the inferior vena cava: report of a case diagnosed by fine needle aspiration cytology and confirmed by histopathologic examination

BACKGROUND: Leiomyosarcoma is a malignant neoplasm and can originate within major abdominal veins, including the inferior venacava (IVC). CASE: A 45-year-old woman presented with upper abdominal pain and a mass lesion in the liver and within the lumen of the IVC. A diagnosis of primary leiomyosarcoma of the IVC was made by using imaging techniques,fine needle aspiration cytology and histopathologic examination of the resected specimen. CONCLUSION: In patients presenting with vague upper abdominal pain and radiologic features of a hepatic mass extending to major veins, the rare possibility of primary leiomyosarcoma of the IVC shoald he considered and investigated by both fine needle aspiration cytology and intraoperative histology. Early surgical intervention and/or postoperative chemotherapy and radiotherapy are associated with improved survival.     

Transvaginal ovum pick-up (OPU) in the cow: a new disposable needle guidance system

A study was conducted to modify the routinely used ovum pick up (OPU) devices to permit use of disposable needles and to simplify the technique and to make it more economical and practical to use. Long nondisposable needles are commonly used in transvaginal OPU despite several disadvantages. A new OPU device was developed using 19-g disposable needles to eliminate these disadvantages and to make the technique more successful. The disposable needle was connected to silicone tubing by means of a stainless steel connector. The system was inserted into a stainless steel tube, creating a rigid structure within which to move the needle back and forth. A blunt needle can be changed simply by replacing it with a new one, even while the device is in the vagina of a cow. The needle guidance system is incorporated into a new OPU device together with the transducer of an ultrasonographic scanner with an unilateral orientated scanning field, making it possible to utilize the needle length to its maximum. This combination permits easy manipulation of the ovaries, easy positioning of follicles on the puncture line, and enables the use of shorter needles which directly enter the scanned area without loss of useful needle length. As a preliminary result we obtained an overall oocyte recovery rate of 42%. Although this is promising, additional puncture sessions are needed to establish more consistent recovery rates. When OPU is used routinely, application of short disposable needles is more practical and economical.     

超声引导下18针与20针穿刺活检对甲状腺结节的诊断效果比较

摘要 目的：比较超声引导下18针与20针穿刺活检对甲状腺结节的诊断效果。方法：选取我院超声科2018.8.6-2020.9.30共收治的167例甲状腺结节患者作为研究对象,将患者分为18针穿刺组（n=86）和20针穿刺组（n=81）,分别对两组患者应用超声引导下18针和20针穿刺活检,比较不确定结果的发生率,包括非诊断性或异型性/滤泡性病变的未确定显著性,恶性肿瘤的诊断性能在最终诊断的结节中进行评估。比较两组并发症发生率及超声引导下的核心针穿刺活检标本产率。结果：对比20针穿刺组和18针穿刺组患者的临床特征发现,两组患者性别、年龄、结节大小、结节形状、方位、回声强度、表现和钙化情况对比无明显差异（P＜0.05）;在20针穿刺组中43个结节和18针穿刺组中46个结节最终确诊。恶性结节的比例在两组之间没有显著差异。在最终诊断分析中,20针穿刺组有38个结节,18针穿刺组中有40个结节。在20针穿刺组,38个结节包括6个非诊断结果、18个不典型/滤泡性病变（未确定显著性）和14个滤泡性肿瘤。在18针穿刺组中,40个结节包括1个非诊断结果,22个不典型/滤泡性病变未确定的显著性,17个滤泡性肿瘤;18针穿刺组的未确诊率（包括非诊断结果和未发现显著性的异型性/滤泡性病变）较低（29.1 % vs 37.0 %）,尽管这一差异在统计学上没有显著性（P＞0.05）。然而,18针穿刺组的非诊断性结果发生率（1.2 % vs 8.6 %;P＜0.05）显著低于20针穿刺组。两组的不典型/滤泡性病变的发生率（27.8 % vs 28.4 %）相似。20针穿刺组的CNB显示出更高的敏感性（75.0 % vs 66.7 %）,更高的阴性预测值（NPV;83.9 % vs 75.9 %）和更高的准确率（78.3 % vs 74.4 %）,虽然结果没有达到统计显著性。两组的特异性（81.8 % vs 80.8 %）和阳性预测值（PPV;两者均为100 %）相似;18针穿刺组和20针穿刺组患者的并发症发生率对比无明显差异（P＞0.05）。结论：18针芯针活检对甲状腺结节的诊断较20针更有效,且不增加并发症情况,安全性好,值得临床应用推广。     

Protective Effects of Cannabidiol on Lesion-Induced Intervertebral Disc Degeneration

Disc degeneration is a multifactorial process that involves hypoxia, inflammation, neoinnervation, accelerated catabolism, and reduction in water and glycosaminoglycan content. Cannabidiol is the main non-psychotropic component of the Cannabis sativa with protective and anti-inflammatory properties. However, possible therapeutic effects of cannabidiol on intervertebral disc degeneration have not been investigated yet. The present study investigated the effects of cannabidiol intradiscal injection in the coccygeal intervertebral disc degeneration induced by the needle puncture model using magnetic resonance imaging (MRI) and histological analyses. Disc injury was induced in the tail of male Wistar rats via a single needle puncture. The discs selected for injury were punctured percutaneously using a 21-gauge needle. MRI and histological evaluation were employed to assess the results. The effects of intradiscal injection of cannabidiol (30, 60 or 120 nmol) injected immediately after lesion were analyzed acutely (2 days) by MRI. The experimental group that received cannabidiol 120 nmol was resubmitted to MRI examination and then to histological analyses 15 days after lesion/cannabidiol injection. The needle puncture produced a significant disc injury detected both by MRI and histological analyses. Cannabidiol significantly attenuated the effects of disc injury induced by the needle puncture. Considering that cannabidiol presents an extremely safe profile and is currently being used clinically, these results suggest that this compound could be useful in the treatment of intervertebral disc degeneration.     

A Modified Method for Heterotopic Mouse Heart Transplantion

Mice are often used as heart transplant donors and recipients in studies of transplant immunology due to the wide range of transgenic mice and reagents available. A difficulty is presented due to the small size of the animal and the considerable technical challenges of the microsurgery involved in heart transplantation. In particular, a high rate of technical failure early after transplantation may result from recipient death and post-operative complications such as hind limb paralysis or a non-beating heart. Here, the complete technique for heterotopic mouse heart transplantation is demonstrated, involving harvesting the donor heart and its subsequent implantation into a recipient mouse. The donor heart is harvested immediately following in situ perfusion with cold heparinized saline and transection of the ascending aorta and pulmonary artery. The recipient operation involves preparation of the abdominal aorta and inferior vena cava (IVC), followed by end-to-side anastomosis of the donor aorta with the recipient aorta using a single running 10-0 microsuture and a similar anastomosis of the donor pulmonary artery with the recipient IVC. Following the operation the animal is injected with 0.6 ml normal saline subcutaneously and allowed to recover on a 37 °C heating pad. The results from 227 mouse heart transplants are summarized with a success rate at 48 hr of 86.8%. Of the 13.2% failures within 48 hr, 5 (2.2%) experienced hind limb paralysis, 10 (4.4%) had a non-beating heart due to graft ischemic injury and/or thrombosis, while 15 (6.6%) died within 48 hr.     

Transport in rat vessel walls. I. Hydraulic conductivities of the aorta, pulmonary artery, and inferior vena cava with intact and denuded endothelia

In this study, filtration flows through the walls of the rat aorta, pulmonary artery (PA), and inferior vena cava (IVC), vessels with very different susceptibilities to atherosclerosis, were measured as a function of transmural pressure (DeltaP), with intact and denuded endothelium on the same vessel. Aortic hydraulic conductivity (L(p)) is high at 60 mmHg, drops approximately 40% by 100 mmHg, and is pressure independent to 140 mmHg. The trends are similar in the PA and IVC, dropping 42% from 10 to 40 mmHg and flat to 100 mmHg (PA) and dropping 33% from 10 to 20 mmHg and essentially flat to 60 mmHg (IVC). Removal of the endothelium renders L(p)(DeltaP) flat: it increases L(p) of the aorta by approximately 75%, doubles L(p) of the PA, and quadruples L(p) of the IVC. Specific resistance (1/L(p)) of the aortic endothelium is approximately 47% of total resistance; i.e., the endothelium accounts for approximately 47% of the DeltaP drop at 100 mmHg. The PA value is 55% at >40 mmHg, and the IVC value is 23% at 10 mmHg. L(p) of the intact aorta, PA, and IVC are order 10(-8), 10(-7), and 5 x 10(-7) cm.s(-1).mmHg(-1), and wall thicknesses are 145.8 microm (SD 9.3), 78.9 microm (SD 3.3), and 66.1 microm (SD 4.1), respectively. These data are consistent with the different wall structures of the three vessels. The rat aortic L(p) data are quantitatively consistent with rabbit L(p)(DeltaP) (Tedgui A and Lever MJ. Am J Physiol Heart Circ Physiol 247: H784-H791, 1984; Baldwin AL and Wilson LM. Am J Physiol Heart Circ Physiol 264: H26-H32, 1993), suggesting that intimal compression under pressure loading may also play a role in L(p)(DeltaP) in these other vessels. Despite very different driving DeltaP, nominal transmural water fluxes of these three vessels are very similar and, therefore, cannot alone account for their differences in disease susceptibility. The different fates of macromolecular tracers convected by these water fluxes into the walls of these vessels may account for this difference.     

家兔经皮枕大池穿刺方法及常见问题

目的探讨提高经皮穿刺兔枕大池成功率的方法及常见问题的处理。方法采用2 mL无菌注射器针头对30只2～2.5 kg新西兰兔行枕大池穿刺,确定穿刺的最佳深度、角度,解决常见问题。结果 25只家兔穿刺成功,其穿刺深度在1.2～1.6 cm之间,平均1.432 cm,5只失败。结论兔枕大池穿刺不要局限于固定深度、角度,应根据动物大小,体位适时作出调整;另外合适的穿刺针可以提高穿刺成功率。     

Calculating lumbar puncture depth in children

Lumbar puncture was performed in 195 children and the depth of needle was recorded. Our results show that the depth of lumbar puncture necessary to obtain uncontaminated cerebrospinal fluid correlates best with the child's weight. The simple formula: mean depth of insertion (cm) = 1.3 + 0.07 x body weight (kg), can be used to estimate the depth of lumbar puncture of children older than 3 months. The depths of lumbar puncture of children younger than 3 months are mostly 1.0-1.5 cm.     

A Randomized Controlled Trial on the Effect of Needle Gauge on the Pain and Anxiety Experienced during Radial Arterial Puncture

Background

Arterial punctures for assessment of arterial blood-gases can be a painful procedure. Lidocaine can be used to reduce pain prior to needle insertion but it is not a widely accepted practice. The purpose of this study was to determine whether a large size needle induces more pain compared to a smaller size needle for radial arterial puncture and to assess the anxiety associated with radial arterial punctures.

Methods

We conducted a prospective, double-blind, randomized, controlled, monocentric study including all outpatients who had a planned assessment of arterial blood gas analysis. Patients were randomized to have the arterial puncture performed with a 23 or a 25 G needle. The main judgement criteria was pain during arterial puncture. Visual analogue scale for pain (VAS-P) and visual analogue scale for anxiety (VAS-A) were used to assess pain and anxiety during radial arterial puncture.

Results

Two hundred consecutive patients were randomized. The 25 G needle was as painful as the 23 G needle (6.63 mm [0–19 mm] vs. 5.21 mm [0–18.49 mm], respectively, p = 0.527). Time for arterial puncture was longer with the 25 G needle than with the 23 G needle (42 s [35–55 s] vs. 33 s [24.5–35 s], respectively, p = 0.002). There was a correlation between the level of anxiety prior to the arterial puncture and the pain experienced by the patients (p: 0.369, p<0.0001). There was a correlation between the pain experienced by patients and the anxiety experienced in anticipation of another arterial puncture (p: 0.5124, p<0.0001).

Conclusions

The use of 23 G needle allows quicker arterial sampling and is not associated with increased pain and symptoms. Anxiety was correlated with the pain experienced by patients during arterial punctures.

Trial Registration

Clinicaltrials.gov: NCT02320916     

Applicability of different endovascular methods for treatment of refractory Budd-Chiari syndrome

The study’s objective was to evaluate the applicability of different endovascular methods for treatment of refractory type of Budd–Chiari syndrome (BCS) under specific scenarios frequently encountered in patients. The treatment methods were evaluated in 197 patients with the following four types of refractory BCS: lesions of the inferior vena cava (IVC) including a special shape diaphragm (e.g., a knife- or a vertically shaped diaphragm, etc.), occlusion of the long segment of IVC, IVC obstruction combined with thrombosis, and occlusion of the hepatic vein. The choice of endovascular treatment depended on the degree of difficulty to puncture the membrane after spatial orientation. There was a need to adjust the curvature of the device to fit the natural angle of IVC. When IVC lesions were combined with thrombosis, the treatment was adjusted depending on the freshness of the thrombus. Different routes were used to rupture the membrane and expand the lesion. The majority of patients recovered without complications. The few complications observed were the following: 1 case of death due to a postoperative stress ulcer, 1 case of a successfully treated pericardial tamponade, 1 case of stent migration, and 3 cases of failure to stent and re-occlusion that occurred in the follow-up period. To conclude, BCS is preferably treated via endovascular intervention; however, the particular choice depends on individual circumstances.     

Transport in rat vessel walls. II. Macromolecular leakage and focal spot size growth in rat arteries and veins

Transendothelial lipid transport into and spread in the subendothelial intima of large arteries, and subsequent lipid accumulation, appear to start plaque formation. We experimentally examine transendothelial horseradish peroxidase (HRP) transport in vessels that are usually, e.g., pulmonary artery (PA), or almost always, e.g., inferior vena cava (IVC), atherosclerosis resistant vs. disease prone, e.g., aorta, vessels. In these vessels, HRP traverses the endothelium at isolated, focal spots, rather than uniformly, for short circulation times. For femoral vein HRP introduction, PA spots have 30-s radii [ approximately 53.2 microm (SD 10.4); compare aorta: 54.6 microm (SD 8.75)] and grow quickly from 30 s to 1 min (40%, P<0.05) and more slowly afterward (P>0.05). This trend resembles the aorta, suggesting the PA has a similarly sparse intima. With carotid artery (CA) HRP introduction, the 30-s spot (132.86 +/- 37.32 microm) is far larger than the PAs, grows little ( approximately 28%, P<0.05) from 30 to 60 s, and is much flatter than the artery curves. Transverse electron microscopic sections after approximately 10 min HRP circulation show thin, intense staining immediately beneath both vessels' endothelia with an almost step change to diffuse staining beyond. This indicates the existence of a sparse, subendothelial intima, even when there is no internal elastic lamina (IVC). This motivates a simple model that translates growth rates into lower bounds for the flow through focal leaks. The model results and our earlier wall and medial hydraulic conductivity data explain these spot growth curves and point to differences in transport patterns that might be relevant in understanding the immunity of IVC to disease initiation.     

Mechanics of anesthetic needle penetration into human sciatic nerve

Nerve blocks are frequently performed by anesthesiologists to control pain. For sciatic nerve blocks, the optimal placement of the needle tip between its paraneural sheath and epineurial covering is challenging, even under ultrasound guidance, and frequently results in nerve puncture. We performed needle penetration tests on cadaveric isolated paraneural sheath (IPS), isolated nerve (IN), and the nerve with overlying paraneural sheath (NPS), and quantified puncture force requirement and fracture toughness of these specimens to assess their role in determining the clinical risk of nerve puncture. We found that puncture force (123 ± 17 mN) and fracture toughness (45.48 ± 9.72 J m⁻²) of IPS was significantly lower than those for NPS (1440 ± 161 mN and 1317.46 ± 212.45 Jm⁻², respectively), suggesting that it is not possible to push the tip of the block needle through the paraneural sheath only, without pushing it into the nerve directly, when the sheath is lying directly over the nerve. Results of this study provide a physical basis for tangential placement of the needle as the ideal situation for local anesthetic deposition, as it allows for the penetration of the sheath along the edge of the nerve without entering the epineurium.     

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.     

CT引导下经皮肺穿刺并发症的高危因素分析

目的:探讨CT引导下经皮肤肺穿刺并发症发生的高危因素.方法:回顾分析93例因肺部肿块行CT引导下经皮肤肺穿刺患者,对其性别、吸烟史、病灶大小、肿块类型、组织学分型、穿刺时体位、进针位置、进针角度和进针深度等因素与穿刺后并发症的相关性进行分析.结果:单因素分析显示吸烟史、病灶大小、肿块类型和进针深度在有并发症患者和无并发症的患者之间存在显著性差异(P＜0.05),多因素分析显示病灶大小、肿块类型和进针深度在两组患者间存在显著性差异(P＜0.05).结论:病灶大小、肿块类型和进针深度为CT引导下经皮肺穿刺并发症出现的高危因素.     

Computational predictions of the embolus-trapping performance of an IVC filter in patient-specific and idealized IVC geometries

Embolus transport simulations are performed to investigate the dependence of inferior vena cava (IVC) filter embolus-trapping performance on IVC anatomy. Simulations are performed using a resolved two-way coupled computational fluid dynamics/six-degree-of-freedom approach. Three IVC geometries are studied: a straight-tube IVC, a patient-averaged IVC, and a patient-specific IVC reconstructed from medical imaging data. Additionally, two sizes of spherical emboli (3 and 5 mm in diameter) and two IVC orientations (supine and upright) are considered. The embolus-trapping efficiency of the IVC filter is quantified for each combination of IVC geometry, embolus size, and IVC orientation by performing 2560 individual simulations. The predicted embolus-trapping efficiencies of the IVC filter range from 10 to 100%, and IVC anatomy is found to have a significant influence on the efficiency results (\(P < 0.0001\)). In the upright IVC orientation, greater secondary flow in the patient-specific IVC geometry decreases the filter embolus-trapping efficiency by 22–30 percentage points compared with the efficiencies predicted in the idealized straight-tube or patient-averaged IVCs. In a supine orientation, the embolus-trapping efficiency of the filter in the idealized IVCs decreases by 21–90 percentage points compared with the upright orientation. In contrast, the embolus-trapping efficiency is insensitive to IVC orientation in the patient-specific IVC. In summary, simulations predict that anatomical features of the IVC that are often neglected in the idealized models used for benchtop testing, such as iliac vein compression and anteroposterior curvature, generate secondary flow and mixing in the IVC and influence the embolus-trapping efficiency of IVC filters. Accordingly, inter-subject variability studies and additional embolus transport investigations that consider patient-specific IVC anatomy are recommended for future work.