Syringe and needle size, syringe type, vacuum generation, and needle control in aspiration procedures

Comparison of fine-needle aspiration techniques

BACKGROUND

Fine-needle aspiration (FNA) has been reported since 1912 beginning with the use of trocars and other specialized instruments that were impractical. Since then, FNA has proven to be a successful alternative technique to excisional biopsy for some assays despite a few limitations.

METHODS

In this study, we compared four different techniques for FNA in rhesus macaques by evaluating total live cells recovered and cell viability using a standard 6 mL syringe and 1.5-inch 22-gauge needle.

RESULTS

Technique B which was the only technique in which the needle was removed from the syringe after collection of the sample to allow forced air through the needle to expel the contents into media followed by flushing of the syringe and needle resulted in the highest total cell count and second highest cell viability in recovered cells.

CONCLUSION

Based on our results, Technique B appears to be the superior method.

Comparison of outcomes of an 18-gauge vs 16-gauge ultrasound-guided percutaneous renal biopsy: a systematic review and meta-analysis

Background: The needle size used in ultrasound-guided percutaneous renal biopsy significantly influences the efficacy and safety of the procedure. The aim of this study is to perform a comparative analysis of 16-gauge and 18-gauge needles for ultrasound-guided percutaneous renal biopsy.Methods: This systematic review and meta-analysis included randomized controlled trials and observational studies that compared the outcomes of using 18-gauge and 16-gauge needles for ultrasound-guided percutaneous renal biopsy. The efficacy parameters included a mean number of glomeruli obtained and the number of passes, while the safety parameters focused on the rate of complications. We searched multiple databases, assessed the risk of bias, and conducted statistical analyses using appropriate models.Results: Fifteen studies were included. Compared to the 18-gauge needle, the use of 16-gauge needle for the biopsy was associated with the significantly higher mean number of glomeruli obtained (pooled SMD 0.61, 95%CI: 0.32 to 0.89; p < 0.001) and fewer required passes (pooled SMD -0.57, 95%CI: -0.97 to -0.18; p = 0.004). No significant difference was observed in the individual safety parameters, including pain, hematuria, need for blood transfusion, major, and minor complications. However, the use of 16-gauge needle was associated with higher odds of total complications (pooled OR 1.57, 95%CI: 1.16 to 2.13; p = 0.004).Conclusion: While the 16-gauge needle for ultrasound-guided percutaneous renal biopsy offers improved efficacy in terms of a higher mean number of glomeruli and fewer required passes, it is associated with higher total complications. A judicious needle size selection that would consider patient-specific factors and risk-benefit ratio, is crucial for optimizing patient outcomes.

Valveless On-Chip Aliquoting for Molecular Diagnosis

The detection of nucleic acids as specific markers of infectious diseases is commonly implemented in molecular biology laboratories. The translation of these benchtop assays to a lab-on-a-chip format demands huge efforts of integration and automation. The present work is motivated by a strong requirement often posed by molecular assays that combine isothermal amplification and CRISPR/Cas-based detection: after amplification, a 2-8 microliter aliquot of the reaction products must be taken for the subsequent reaction. In order to fulfill this technical problem, we have designed and prototyped a microfluidic device that is able to meter and aliquot in the required range during the stepped assay. The operation is achieved by integrating a porous material that retains the desired amount of liquid after removing the excess reaction products, an innovative solution that avoids valving and external actuation. The prototypes were calibrated and experimentally tested to demonstrate the overall performance (general fluidics, metering, aliquoting, mixing and reaction). The proposed aliquoting method is fully compatible with additional functions, such as sample concentration or reagent storage, and could be further employed in alternative applications beyond molecular diagnosis.

An analysis of the effect of syringe barrel volume on performance and user perception

In the market, there are many types and shapes of syringes. One of the groupings of syringe types is based on barrel volume. The shape of the product design affects performance and user perception. The aim of this study is to investigate the effect of barrel volume on its performance and user perception. We performed analysis following international organization for standardization 7886 procedures on syringe with 1 mL, 3 mL, 5 mL, and 10 mL volume. In addition, a user perception test was conducted on 29 respondents using a questionnaire with the Likert chart method. This study indicates that the bigger the syringe volume, the larger the dead space and the force to operate the piston are. A larger syringe volume also raises the volume that changes due to the plunger position increase. Meanwhile, the barrel volume does not affect water and water leakage, as we did not observe any leak during the syringe tests in our experiment. In addition, the user perception test shows that the barrel's length influences the ease of device control during the injection. The volume of the barrel negatively correlated with its effect to the environment. The safety features of all syringes are similar except for the 3 mL syringe, which has a value of 0.1 points difference to other syringes.

The hypodermic syringe performance based on the ISO 7886-1:2017: A narrative review

A syringe is used to inject fluid or medicine into the patient's soft tissue. The main components of the syringe were the needle, barrel, and plunger. The use of syringes in the medical world is relatively high, and especially since the COVID-19 pandemic, the use of hypodermic syringes increased sharply due to vaccination. The syringe used must be effective and of good quality, so the International Organization for Standardization (ISO) has published test procedures and minimum specifications for hypodermic syringes. The performance of the syringe can be observed from the dead space, force piston operation, water and air leakage, and fitting position of the plunger in the barrel. This review shows that most researchers use the weighing method to measure the dead space, although some use other methods. The researchers found that most of the products met the minimum specifications of the ISO, and that the dimensions and shape of the syringe affected the dead space. Researchers have not examined other performance measures recommended by the ISO. Researchers have focused more on force injection than force piston operation, leakage after injection or back spray than air and water leakage, and reduction the friction of the plunger without considering the fitting position of the plunger in the barrel.

Hip aspiration: A comparison of ultrasound and fluoroscopic guidance

Introduction

Hip aspirations are commonly performed for diagnostic purposes using either fluoroscopic or ultrasound guidance. The superiority of one type of image guidance over another for aspiration of a native or replaced hip remains a matter of debate. The questions to be evaluated in this study include 1) to determine if hip aspiration using fluoroscopy or ultrasound guidance more often obtains fluid from native and post-arthroplasty hip joints, and 2) to identify patient-related factors associated with the ability to obtain fluid.

Material and methods

A retrospective analysis of all hip aspirations (433) performed at a single institution was undertaken, with the primary outcome variable being successful attainment of joint fluid. Age, body mass index (BMI), sex, presence of a trainee, presence of an arthroplasty at the time of aspiration on the affected side, amount of fluid collected, and type of image guidance were used as independent variables in regression models.

Results

1) The likelihood of obtaining fluid was approximately 2.1 times greater with ultrasound guidance than fluoroscopy guidance (95% CI = 1.382, 3.117; p < 0.001). 2) Ultrasound guidance and lower BMI were independently associated with a significantly higher likelihood of obtaining fluid. Additionally, one unit decrease in BMI was associated with about a 3% increase in the odds of obtaining fluid (95% CI = 0.950, 0.998; p = 0.033).

Conclusion

This study demonstrates that the use of ultrasound guidance for hip joint aspiration, when compared to fluoroscopic guidance, is more likely to result in a successful aspiration and the acquisition of a greater volume of fluid. Therefore, ultrasound guidance is the preferred method for hip aspiration in both native and replaced hips.

Measurement of aspiration pressure in cannula brain tumour biopsy and its correlation with ultrasonographic elastography

BACKGROUND

Stereotactic brain biopsy is to perform the manual aspiration tissue biopsy using a cannula on a syringe under stereotactic guidance to provide histological confirmation. Excessive vacuum aspiration increases the risk of haemorrhage. Manual aspiration relies on the surgeon's experience while the minimum vacuum pressure is unknown.

OBJECTIVES

1. To assess the aspiration vacuum pressure range in cannula brain tumour biopsy; 2. To understand the correlation of ultrasound elastography data with the aspiration pressure.

METHODS

This prospective study has recruited 10 patients for stereotactic brain tumour biopsy. With the use of ultrasound elastography, strain ratio of the lesion was assessed in real time before biopsy. Vacuum aspiration pressures were recorded using a T-connector pressure sensor during the stereotactic biopsy.

RESULTS

A total of 11 biopsies were taken from 10 patients, including a bilateral biopsy for a patient with bifrontal lesions. The diagnostic yield was 100% in all the 10 patients with no symptomatic haemorrhage (but 2 subclinical haemorrhages in CT scan) nor infection. The vacuum pressures ranged from 40.34 to 65.61 kPa and the strain-ratio ranged from 0.405 to 2.74. Strain ratio of the lesion at the lower range required a lower range of aspiration pressure, whereas lesions of Strain ratio over 0.45 required a higher range of aspiration pressure.

CONCLUSION

A vacuum pressure of 40 to 66 kPas is safe and adequate for biopsy of various types of tumours with heterogenous elastographic characters. Ultrasonographic elastography may be a real-time guide for the minimum vacuum pressure required for biopsy.

Utilization of High-pressure Suction for EBUS-TBNA Sampling in Suspected Lung Cancer

BACKGROUND

Sample adequacy for immediate molecular testing is paramount in lung cancer. To date, several endobronchial ultrasound with transbronchial needle aspiration (EBUS-TBNA) sampling setups have been evaluated, however, the utilization of high-pressure suction (HPS) has not yet been reported.The aim of this study was to evaluate the utilization of HPS onto the needle and its effect on sample volume and adequacy for molecular testing in patients with suspected lung cancer.

METHODS

We retrospectively analyzed 128 consecutive EBUS-TBNA performed for suspected lung cancer. This was confirmed in 109 patients. Other diagnoses confirmed in 12, and 7 referred for surgery. Sixty-three patients (89 targets) had HPS (May to September 2020), and compared with 46 (72 targets) who had standard vacuum syringe suction (October 2019 to March 2020). Several parameters and outcomes evaluated, such as number of needle passes, needle strokes, needle size, target size, positron emission tomography avidity, procedure time, blood content score, sample volume, adequacy for molecular testing, as well as baseline patient characteristics and complication rate.

RESULTS

There was no difference between the 2 groups in all baseline parameters and characteristics. In multivariable analysis, HPS was associated with significantly higher sample volume (11.2 vs. 9.1 mm3, P=0.036) and less additional procedures to achieve full molecular profiling (2/52 vs. 7/40, P=0.042), in necrotic targets of non-small cell lung cancer. Diagnostic yields were comparable.

CONCLUSION

HPS appears to be simple, no-cost, and safe, promising higher sample volume compared with vacuum syringe suction, and also appears to be associated with higher success of full molecular testing with less additional procedures, in non-small cell lung cancer necrotic targets.

A Cross-sectional Survey of Enteral Feeding Tube Placement and Gastric Residual Aspiration Practices: Need for an Evidence-Based Clinical Practice Guideline

BACKGROUND

Preterm infants routinely require enteral feeding via nasogastric or orogastric tubes as an alternative to oral feeding to meet their nutritional needs. Anecdotal evidence suggests variations in practice related to correct tube placement and assessment of feed intolerance.

PURPOSE

To determine the current practices of enteral feeding tube placement confirmation and gastric residual (GR) aspiration of neonatal clinicians in Australia.

METHODS

A cross-sectional online survey comprising 24 questions was distributed to nursing and medical health professionals working in Australian neonatal care units through 2 e-mail listservs made available by professional organizations.

FINDINGS

The survey was completed by 129 clinicians. A single method was practiced by 50% of the clinicians in confirming tube placement, and most common practice was assessing the pH of GR aspirate. The majority of respondents (96%) reported that they relied on GR aspiration and clinical signs to determine feeding tolerance and subsequent decisions such as ceasing or decreasing feeds. However, the frequency of aspiration, the amount and color of aspirate considered to be normal/abnormal, and decisions on whether to replace gastric aspirate or whether aspiration should be performed during continuous tube feeding varied.

IMPLICATION FOR PRACTICE

This study demonstrated considerable variability in clinical practice for enteral feeding tube placement confirmation and GR aspiration despite most respondents reporting using a unit-based clinical practice guideline. Our study findings highlight the need for not only developing evidence-based practice guidelines for safe and consistent clinical practice but also ensuring that these guidelines are followed by all clinicians.

IMPLICATION FOR RESEARCH

Further research is needed to establish evidence-based methods both for enteral feeding tube placement confirmation and for the assessment of feeding intolerance during tube feeding. In addition, the reasons why evidence-based methods are not followed must be investigated.

Ultrasound-Guided Knee Injections Are More Accurate Than Blind Injections: A Systematic Review of Randomized Controlled Trials

Purpose

To review the current literature to determine which injection technique and needle portal placement provide the greatest accuracy for intra-articular access to the knee.

Methods

This study followed Preferred Reporting Items and Systematic Reviews and Meta-Analyses guidelines. A comprehensive literature search was conducted in March 2020 and repeated in May 2020 using electronic databases PubMed, MEDLINE, and the Cochrane Library. Data on the accuracy of intra-articular knee injection (successful injections/total number of injections) were collected. Only Level I studies were included. Study design, demographic variables, needle sizes, and method of validating accuracy were recorded. The Jadad score was used to assess methodologic quality, and a risk-of-bias assessment was performed.

Results

A total of 12 Level I human studies (1431 patients, 1315 knees) were included in this review. Seven of the studies did a direct comparison between ultrasound-guided and blind knee injections. Ultrasound-guided injections were more accurate compared with blinded knee injections in every study. The most accurate anatomical approach was an isometric quadricep contraction method with the superolateral approach.

Conclusions

This study showed that ultrasound-guided knee injections were more accurate across every anatomical needle injection site compared with blind injections. Injections made by a blind/anatomically guided method had inconsistent accuracy rates that seemed highly dependent on the portal of entry.

Level of Evidence

Level I, systematic review of Level I studies.

The utility of a novel vacuum-assisted foreign body extraction technique from wounds

Retained soft tissue foreign bodies following injuries are frequently seen in the Emergency and Plastic Surgery practice. The patients with such presentations require a watchful and detailed clinical assessment to overcome the anticipant possibility of missing them. However, the diagnosis based on the clinical evaluation is usually challenging and needs to be supported by imaging modalities that are suboptimal and may fail in identifying some types of foreign bodies. Owing to that, serious complications such as chronic pain, infection, and delayed wound healing can be faced that necessitate a prompt intervention to halt those detrimental consequences. The classical method of removal is a surgical exploration which is not free of risks. It can cause injuries to vital structures such as nerves and tendons if the foreign body is close to them, also it can be affected by the surgeon's experience and the foreign body's characteristics.

In light of that, we conducted a single-center study to understand the utility of a novel vacuum-assisted technique for foreign body removal. The technique is noninvasive and facilitates a real-time foreign body extraction using readily available materials. Twenty patients with 23 Foreign Bodies of various kinds, shapes, and sizes were recruited in our study by using a nonprobability convenient sampling method. Results demonstrated the ability of the described technique to extract 22 of them with no noticeable side effects. This study may encourage further trials adopting similar principles to promote the management of retained foreign bodies with fewer complications, and a potential of time and cost-saving.

In Vitro Evaluation of Stone Fragment Evacuation by Suction

Introduction: Contemporary, flexible stone baskets are unable to extract submillimeter stone fragments at the time of ureteroscopic laser lithotripsy. In this in vitro study, the feasibility of suctioning submillimeter fragments with a standard Luer Lock syringe through the working channel of a flexible ureteroscope was assessed. Materials and Methods: Phantom stones made from industrial plaster were mechanically fragmented into ≤1 and ≤0.5-mm groups. Both stone groups were divided into five preweighed trial samples. Each stone group was then mixed in a beaker filled with normal saline. A standard 10-mL Luer Lock syringe was connected to a fiber-optic ureteroscope with a 1.2-mm working channel. The syringe was then used to suction stone fragments from the beaker. The suctioned stone fragments and the stone fragments remaining in the beaker after removing the overlying solution were separated, centrifuged with supernatant removed, and dried in an incubator set at 33°C for 1 week. Dried weights were recorded. Results: Mean total weights for ≤0.5 and ≤1.0-mm stone groups at baseline were 0.807 and 0.806 g, respectively. The mean percentages of stone fragments suctioned through the ureteroscope for ≤0.5 and ≤1.0-mm groups were 86% and 86%, respectively (p = 0.973). During suctioning, 64% of stones in the ≤0.5-mm group were trapped in either the working channel of the ureteroscope or within the Luer Lock syringe compared with 78% of stones in the ≤1-mm group (p = 0.001) requiring cessation of the procedure to clear the channel. Conclusions: It is feasible to suction submillimeter stone fragments by connecting a Luer Lock syringe to the working channel of a flexible ureteroscope. The limiting factor for removing stone fragments appears to be the small working channel of flexible ureteroscopes as trapping of fragments during suctioning is common and requires time-consuming removal of the endoscope and clearing of the channel.

Lumbar puncture under fluoroscopy guidance: a technical review for radiologists

There are many differences in fluoroscopy-guided lumbar puncture (FG-LP) technique among radiologists. Even within the same institution, there are a variety of preferences among proceduralists with individual perspectives based on the literature, training, and/or experience. Our aim is to provide familiarity with various techniques involved in FG-LP and provide insight on how to improve patient outcomes. The pertinent anatomy and physiology, indications, contraindications, patient management, complications of the procedure, and procedural techniques for performing an FG-LP are reviewed in detail. Potentially controversial topics regarding FG-LP are also addressed. There are many differences in fluoroscopy-guided lumbar puncture (FG-LP) technique among radiologists (1). Even within the same institution, there are a variety of individual preferences among physicians with different perspectives based on a combination of literature familiarity, training, and personal experience. Our aim is to provide familiarity with various techniques involved in FG-LP, improve efficiency, and improve patient outcomes. We will also address possible controversial issues regarding FG-LPs using an evidence-based approach.

The diagnostic quality of needle brain biopsy specimens obtained with different sampling methods - Experimental study

The aim is to examine whether brain tissue samples obtained through needle biopsy are better for histopathological evaluation when obtained with defined vacuum pressure, a novel needle rotation method, and using different needle type - Laitinen or Nashold. Moreover the paper aims to answer the question: Does vacuum and mechanical injury resulting from different sampling methods damage the tissue specimen challenging the diagnosis?. Eight hundred biopsy specimens from fresh swine brains were obtained using Nashold and Laitinen brain biopsy needles through inner cannula cutting or needle rotation sampling at vacuum pressure, from 0 to 0.06 MPa. The specimen weight and tissue quality for microscopic assessment were evaluated using the Mair score. Rising aspiration pressure increased the biopsy sample weight. Needle rotation delivered larger biopsy samples than the standard method. Laitinen provided larger samples than the Nashold needle, with the same sampling method or vacuum pressure. A higher histopathological diagnostic quality of tissue was obtained with the Laitinen needle than with Nashold, with higher vacuum pressure than lower pressure and finally with needle rotation than the standard method. No tissue damage caused by higher suction pressure or method of tissue separation was documented. Brain tissue samples obtained through needle biopsy are better for histopathological evaluation when obtained with higher vacuum pressure, a novel needle rotation method and with Laitinen needle. Higher suction pressure and sampling methods did not cause tissue damage.

Accuracy of ultrasonography and fine-needle aspiration cytology in the diagnosis of prostate diseases in dogs

Clinical signs of prostatic diseases in dogs are often non-specific. Appropriate treatment should be based on a detailed investigation using reliable diagnostic tools. The aim of our study was to evaluate the diagnostic value of ultrasonography (US) and fine-needle aspiration (FNA) cytology in dogs' prostate diseases. The mean accuracy of FNA cytology and US were 0.72 and 0.88 (n = 13), respectively. US gland size measurements and actual gland dimensions were highly concordant. Obtained results confirm the high diagnostic value of US and FNA biopsy and in prostatic diseases. Diagnosis based on US is highly reliable; however, it should be combined with clinical signs. Therefore, cytological evaluation of prostate gland material may be performed to differentiate or confirm presumptive diagnosis.

Optimizing Patient Outcomes and Safety With Liposuction

Since its advent in the early 1980s, liposuction has made tremendous advancements, making it the most popular aesthetic surgery performed today. The goal of this Continuing Medical Education (CME) article is to provide a foundation of knowledge of the relevant anatomy, preoperative evaluation, intraoperative technique, and postoperative management for surgeons performing liposuction. Finally, the prevention and management of potential complications will be reviewed along with measures to optimize patient safety and outcomes.

Proceedings of the signature series symposium "cellular therapies for orthopaedics and musculoskeletal disease proven and unproven therapies-promise, facts and fantasy," international society for cellular therapies, montreal, canada, may 2, 2018

The Signature Series Symposium "Cellular Therapies for Orthopaedics and Musculoskeletal Disease Proven and Unproven Therapies-Promise, Facts and Fantasy" was held as a pre-meeting of the 26^th International Society for Cellular Therapy (ISCT) annual congress in Montreal, Canada, May 2, 2018. This was the first ISCT program that was entirely dedicated to the advancement of cell-based therapies for musculoskeletal diseases. Cellular therapies in musculoskeletal medicine are a source of great promise and opportunity. They are also the source of public controversy, confusion and misinformation. Patients, clinicians, scientists, industry and government share a commitment to clear communication and responsible development of the field. Therefore, this symposium convened thought leaders from around the world in a forum designed to catalyze communication and collaboration to bring the greatest possible innovation and value to patients with musculoskeletal conditions.

Comparison of pore water samplers and cryogenic distillation under laboratory and field conditions for soil water stable isotope analysis

We used pore water samplers (PWS) to sample for isotope analysis (1) only water, (2) soil under laboratory conditions, and (3) soil in the field comparing the results with cryogenic extraction (CE). In (1) and (2), no significant differences between source and water extracted with PWS were detected with a mean absolute difference (MAD) always lower than 2 ‰ for δ²H and 1 ‰ for δ¹⁸O. In (2), CE water was more enriched than PWS-extracted water, with a MAD respect to source water of roughly 8 ‰ for δ²H and 4 ‰ for δ¹⁸O. In (3), PWS water was enriched relative to CE water by 3 ‰ for δ²H and 0.9 ‰ for δ¹⁸O. The latter result may be due to the distinct water portions sampled by the two methods. Large pores, easily sampled by PWS, likely retain recent, and enriched, summer precipitation while small pores, only sampled by CE, possibly retain isotopically depleted water from previous winter precipitation or irrigation inputs. Accuracy and precision were greater for PWS relative to CE. PWS is therefore suggested as viable tool to extract soil water for stable isotope analysis, particularly for soils used in this study (sandy and silty loams).

Pars-plana fluid aspiration for positive vitreous cavity pressure in anterior segment surgeries

Positive vitreous pressure due to misdirection of aqueous or choroidal effusion leads to shallowing of the anterior chamber (AC) before or during anterior segment surgeries. This shallow AC if not addressed makes surgery difficult and increases the risk of surgical complications. Methods to prevent and manage this condition described in literature are not without problems. We describe a minimally invasive technique of passing a 30G needle through the pars-plana to aspirate misdirected fluid from vitreous cavity either as a prophylaxis just before surgery or during it, thereby decreasing positive vitreous pressure. This technique, used in 12 eyes, seems to be effective in patients with angle-closure glaucoma, malignant glaucoma, and per-operative sudden increase in vitreous pressure during surgery. Small-incision surgeries are ideally suited for this procedure. This minimally invasive technique is simple to perform and complications are unlikely to be more than what is seen with intravitreal injections.

Simple, low-cost fabrication of semi-circular channel using the surface tension of solder paste and its application to microfluidic valves

This work presents a simple, low-cost method to fabricate semi-circular channels using solder paste, which can amalgamate the cooper surface to form a half-cylinder mold using the surface tension of Sn-Pd alloy (the main component in solder paste). This technique enables semi-circular channels to be manufactured with different dimensions. These semi-circular channels will then be integrated with a polymethylmethacrylate frame and machine screws to create miniaturized, portable microfluidic valves for sequential liquid delivery and particle synthesis. This approach avoids complicated fabrication processes and expensive facilities and thus has the potential to be a useful tool for lab-on-a-chip applications.

Fabrication of optimized oil-water separation devices through the targeted treatment of silica meshes

Efficient oil-water separation is achieved using an optimized superhydrophobic material, generated by the zeolitic roughening and subsequent hydrophobic surface treatment of silica filter membranes. The material is both highly rough and intrinsically hydrophobic, resulting in superhydrophobic membranes which show a substantial affinity for hydrophobic solvents and oils. The membranes are syringe-mounted, suction pressure is applied and the selective collection of oil is achieved. The membranes are extremely robust, which is a result of the zeolitic roughening process, they possess small pores (0.7 μm), as a result these devices can perform complete separation and operate at a range of suction pressures. The devices could be readily used in a range of real-world applications, including oil spill clean-up and industrial filters.

The influence of needle gauge and infection source on vitreous aspirate cultures

BACKGROUND/AIMS

While the Endophthalmitis Vitrectomy Study (EVS) included only post-cataract surgery patients, the methods and data from that study are widely applied in the management of endophthalmitis of all types. We sought to examine how our experience with in-office vitreous aspiration differed from the EVS in two ways: first, by reviewing microbiological culture yields from vitreous aspirates obtained using 30-gauge needles versus 25-27-gauge needles and second, by reviewing culture yields in cases of endogenous versus non-endogenous endophthalmitis.

METHODS

Cases of endophthalmitis over a 14-year period were reviewed when vitreous tap was the initial diagnostic procedure. The data included infection source, needle size used to obtain a vitreous aspirate, organism cultured and rates of unsuccessful attempts at vitreous aspiration or dry taps.

RESULTS

10 cases were endogenous endophthalmitis, while 36 cases were a mix of postoperative, post-traumatic, post-intravitreal injection and miscellaneous patients. A positive microbiological culture was obtained in 11/36 (31%) of vitreous taps using a 25-27-gauge needle and in 8/10 (80%) taps using a 30-gauge needle (p<0.01). A positive vitreous culture was obtained in 18/36 (50%) of all non-endogenous cases, while a positive result was obtained in 0/10 (0%) cases of endogenous endophthalmitis (p<0.01).

CONCLUSIONS

The use of a smaller needle in obtaining vitreous samples in endophthalmitis did not lower the microbiological yield. A positive microbiological yield was significantly less likely in cases of endogenous endophthalmitis compared with non-endogenous cases. Vitreous tap as a method for identifying the causative organism in endogenous endophthalmitis was of limited utility.

Cardiovascular innovations: Novel mechanical aspiration system to improve thrombus aspiration speed, force, and control

Thrombectomy in coronary arteries and peripheral vasculature is a common procedure performed with electromechanical thrombectomy systems and basic syringe-catheter combinations. Electromechanical systems are associated with speed, power, high-cost, and complexity while basic syringe aspiration systems are associated with ease-of-use, lower cost, and less aspiration force. This report describes a novel mechanical thrombus aspiration system designed to improve aspiration speed and performance plus associated cases studies.

Does ultrasound guidance improve the outcomes of arthrocentesis and corticosteroid injection of the knee?

OBJECTIVE

The present randomized controlled trial compared arthrocentesis of the effusive knee followed by corticosteroid injection performed by the conventional anatomic landmark palpation-guided technique to the same procedure performed with ultrasound (US) needle guidance.

METHODS

Sixty-four palpably effusive knees were randomized to (i) palpation-guided arthrocentesis with a conventional 20-mL syringe (22 knees), (ii) US-guided arthrocentesis with a 25-mL reciprocating procedure device (RPD) mechanical aspirating syringe (22 knees), or (iii) US-guided arthrocentesis with a 60-mL automatic aspirating syringe (20 knees). The one-needle two-syringe technique was used. Outcome measures included patient pain by the Visual Analogue Scale (VAS) for pain (0-10 cm), the proportion of diagnostic samples, synovial fluid volume yield, complications, and therapeutic outcome at 2 weeks.

RESULTS

Sonographic guidance resulted in 48% less procedural pan (VAS; palpation-guided: 5.8 ± 3.0 cm, US-guided: 3.0 ± 2.8 cm, p < 0.001), 183% increased aspirated synovial fluid volumes (palpation-guided: 12 ± 10 mL, US-guided: 34 ± 25 mL, p < 0.0001), and improved outcomes at 2 weeks (VAS; palpation-guided: 2.8 ± 2.4 cm, US-guided: 1.5 ± 1.9 cm, p = 0.034). Outcomes of sonographic guidance with the mechanical syringe and automatic syringe were comparable in all outcome measures.

CONCLUSIONS

US-guided arthrocentesis and injection of the knee are superior to anatomic landmark palpation-guided arthrocentesis, resulting in significantly less procedural pain, improved arthrocentesis success, greater synovial fluid yield, more complete joint decompression, and improved clinical outcomes.