Puncture Angle Research Articles

Feasibility and safety of CT-aided pericardiocentesis from a subxiphoid anterior approach by using fluoroscopy in patients with chronic pericardial effusions.

BackgroundPericardiocentesis is an essential procedure for the diagnosis and treatment of pericardial effusions. The purpose of this study was to evaluate the feasibility and safety of a subxiphoid anterior approach using fluoroscopy aided by a sagittal axis chest computed tomography (CT) view in comparison with an ultrasound‐guided apical approach in patients with chronic pericardial effusion.MethodsAmong 72 consecutive patients (68.8 ± 14.4 years old, 52 males) with hemodynamically stable chronic pericardial effusions, a total of 85 procedures were retrospectively analyzed. We divided them into two groups according to the site of the approach for the pericardiocentesis.ResultsA subxiphoid anterior approach (n = 53) was performed guided by fluoroscopy. The sagittal axis view of the chest CT was constructed to determine the puncture angle and direction for the subxiphoid anterior approach. An apical approach (n = 32) was performed by ultrasound guidance. The success rates of the anterior and apical approaches were 98.1% and 93.8%, respectively. There were two cases with cardiac perforations in the apical approach group, while no cases developed perforations in the subxiphoid anterior approach group.ConclusionThe subxiphoid anterior approach for pericardiocentesis was feasible and safe for managing chronic pericardial effusions. A reconstruction of the sagittal axis view of the chest CT imaging was helpful to identify the direction and depth to access the pericardial space from the subxiphoid puncture site before the pericardiocentesis using the lateral fluoroscopic view.

Effects of Stellate Ganglion Block Through Different Approaches Under Guidance of Ultrasound.

ObjectiveThis study aimed to investigate the effects of stellate ganglion block (SGB) through different approaches under guidance of ultrasound.MethodsA total of 130 patients undergoing SGB in our hospital between February 2019 and February 2020 were enrolled as the research subjects. According to the random number table method, these subjects were divided into two groups: a modified 6th cervical vertebra (C6) group (n = 65) and a 7th cervical vertebra (C7) group (n = 65). Under the guidance of ultrasound, the subjects in the modified C6 group were punctured at the level of the C6 transverse process, and the subjects in the C7 group were punctured at the level of the C7 transverse process. The operation duration, number of puncture angle adjustments, block effects, and adverse reactions for SGB were compared between the two groups.ResultsThe modified C6 group showed shorter SGB operation duration and a lower number of puncture angle adjustments than the C7 group, and the differences were statistically significant (P < 0.05). Horner Syndrome occurred in both groups after SGB. The incidence of adverse reactions in the modified C6 group was 4.62%, comprising 1 case of hoarseness and 2 cases of slowed pulse, while that in the C7 group was 6.15%, with 1 case of hoarseness and 3 cases of slowed pulse; the difference between the two groups was not statistically significant (P > 0.05).ConclusionThe operation duration for modified SGB guided by ultrasound puncturing at the C6 transverse process is shorter and requires fewer puncture angle adjustments than puncturing at the C7 transverse process; however, there is no significant difference between the incidence of adverse reactions or the blocking effects of the two methods.

An initial experience of computed tomography-guided trans superior vena caval biopsy: a novel approach for precarious mediastinal lesions.

PurposeAs interventional radiologists, we encounter precarious deep-seated mediastinal lesions in our day-to-day practice. The conventional technique of percutaneous transthoracic biopsy of these lesions carries significant intrinsic complications. Endovascular approaches for such lesions under fluoroscopic guidance have been described in previous literature but with significant technical constraints. In this article, we would like to describe the novel approach of computed tomography (CT)-guided trans superior vena caval biopsy, which we have performed in 3 consecutive precarious mediastinal lesions.Material and methodsWe placed a vascular sheath under ultrasound and fluoroscopic guidance considering the intended angle of needle puncture and length to reach the target lesion from the puncture site. With the sheath in situ, the trans superior vena caval biopsy was performed under CT guidance, and multiple cores of target tissue were safely and successfully obtained.ResultsWe have carefully and successfully employed this novel technique of CT-guided trans superior vena caval approach for 3 tricky deep-seated mediastinal lesions with very low risk of complications.ConclusionsThrough this article, we would like to enhance the importance of thought-provoking new techniques in tackling complex challenging referrals.

Transseptal puncture in patients with septal occluder devices during catheter ablation of atrial fibrillation.

An atrial septal occluder (ASO) represents a major obstacle to the widespread adoption of atrial fibrillation (AF) catheter ablation in patients with prior atrial septal defect (ASD) closure. The aim of this study was to describe the 'sequential technique' of transseptal puncture (TSP) in AF patients with ASO. Sixty-four drug-refractory AF patients with ASO who underwent catheter ablation in our centre from September 2007 to March 2020 were enrolled. Puncture through the native septum was achieved in 29 patients (Group A) and through the device in 35 patients (Group B). The mean diameter of the occluder was significantly larger in Group B than in Group A (31.6±4.6 mm vs 22.8±3.5 mm, p<0.001). The mean time of TSP (24.9±8.8 vs 5.8±2.1 min, p<0.001), total fluoroscopy time (23.7±10.9 vs 7.5±4.4 min, p<0.001), and total procedure time (172.7±58.3 vs 123.4±43.8 min, p=0.001) of Group B were significantly longer than those of Group A. In Group B, the external sheath crossed the device by reshaping the needle and adjusting the puncture angle and position in 23 patients (Group B1), while the external sheath crossed the device with the assistance of balloon dilation in 12 patients (Group B2). No patient had thrombus, periprocedural interatrial shunt or procedural complications. TSP and AF ablation in patients with ASO are feasible and safe. The 'sequential technique' could be safely used in patients with ASO.

Investigation on puncture mechanical performance of tracheal tissue

This paper investigated the mechanical behavior of the contact between the oblique tip puncture needle and the tracheal tissue during pathological examination for the diagnosis of respiratory diseases. By analyzing the force of the oblique tip puncture needle, this paper established a theoretical model of the contact mechanics between the needle and the tracheal tissue. With the material characteristics, needle diameter and puncture angle of trachea tissue as the loading conditions, the biomechanical simulation of piercing process was carried out by using the finite element simulation method, and realistic puncture experiments on isolated porcine tracheal tissue were performed by electronic universal testing machine. The results showed that the puncture needle was mainly subjected to the combined effect of cutting force, clamping force and frictional force on the needle shaft. When the needle diameter was 22G, penetrating the tracheal tissue vertically, the force on the needle was minimal. Meanwhile, it was found that the error between the experimental and theoretical values of the puncture force did not exceed 10%, thus verifying the feasibility of the hypothetical model of the puncture force in the tracheal tissue rupture stage. It provided a theoretical basis for the intervention of surgical instruments and reduced surgical risks.

A combination of digital design and three-dimensional printing to assist treatment of thoracolumbar compression fractures using percutaneous kyphoplasty

ObjectiveTo evaluate the clinical efficacy of the preoperative digital design combined with three-dimensional (3D) printing models to assist percutaneous kyphoplasty (PKP) treatment for thoracolumbar compression fractures. MethodsFrom January 2018 to August 2020, we obtained data of 99 patients diagnosed thoracolumbar compression fractures. These patients were divided into control group (n = 50) underwent traditional PKP surgery, and observation group (n = 49) underwent preoperative digital design combined with 3D printing model assisted PKP treatment. The clinical efficacy was evaluated with five parameters, including operation time, number of intraoperative radiographs, visual analogue scale (VAS) score, Cobb Angle change, and high compression rate of injured vertebrae. ResultsThere were statistically significant differences of operation time and number of intraoperative radiographs between the two groups (P < 0.05). For VAS score, Cobb Angle change and vertebral height compression rate, all of these three parameters were significantly improved when the patients accepted surgery treatment in two groups (P < 0.05). However, there were no significant differences between control group and observation group for these three parameters either before or after surgery (P > 0.05). ConclusionsThrough the design of preoperative surgical guide plate and the application of 3D printing model to guide the operation, the precise design of preoperative surgical puncture site and puncture Angle of the injured vertebra was realized, the number of intraoperative radiographs was reduced, the operation time was shortened and the operation efficiency was improved.

Total Fluoroscopy Time Reduction During Ultrasound- and Fluoroscopy-Guided Percutaneous Transhepatic Biliary Drainage Procedure: Importance of Adjusting the Puncture Angle.

BackgroundThe purpose of this observational cohort study was to assess patient and operator-dependent factors which could have an impact on total fluoroscopy time during ultrasound and fluoroscopy-guided percutaneous transhepatic biliary drainage (PTBD).Material/MethodsBetween October 2016 and November 2020, 127 patients with malignant biliary obstruction underwent ultrasound- and fluoroscopy-guided PTBD with the right-sided intercostal approach. The initial bile duct puncture was ultrasound-guided in all patients, and the puncture angle was measured by ultrasound. Any subsequent steps of the procedure were performed under continuous fluoroscopy (15 fps). The patients were divided in 2 groups based on the puncture angle: ≤30° (group I) and >30° (group II). In a retrospective analysis, both groups were compared for inter- and intragroup variability, technical success, total fluoroscopy time, and complications.ResultsIn group II, the recorded total fluoroscopy time (232.20±140.94 s) was significantly longer than that in group I (83.44±52.61 s) (P<0.001). In both groups, total fluoroscopy time was significantly longer in cases with a lesser degree of bile duct dilatation, intrahepatic bile duct tortuosity, presence of liver metastases, and multiple intrahepatic bile duct strictures.ConclusionsThe initial bile duct puncture angle was identified as an operator-dependent factor with the possible impact on total fluoroscopy time. The puncture angle of less than 30° was positively correlated with overall procedure efficacy and total fluoroscopy time reduction.

Image-guided, surgical robot-assisted percutaneous puncture of the foramen ovale and foramina stylomastoideum: a cadaveric study.

Image-guided, surgical robot-assisted percutaneous puncture of the foramen ovale and foramina stylomastoideum: a cadaveric study.

Development and Validation of a Random Forest Risk Prediction Pneumothorax Model in Percutaneous Transthoracic Needle Biopsy.

BackgroundComputed tomography (CT)-guided percutaneous transthoracic needle biopsy (PTNB) is an effective means for diagnosing various thoracic diseases. Pneumothorax is the most common complication, and when it becomes life-threatening, urgent medical intervention is required. The purpose of this study was to develop and validate a model that can be used to predict postoperative pneumothorax following CT-guided PTNB.Material/MethodsWe enrolled 245 patients who completed CT-guided PTNB to develop the model. A random forest (RF) model was built using 15 risk factors (15-RFs). The 7 most critical risk factors (7-RFs) were extracted by feature selection and used to build a new model. The independent external validation data contained 97 patients. Logistic regression (LR), support vector machine (SVM), and decision tree (DT) models were also developed using both 15-RFs and 7-RFs, and their performance was compared with the RF models.ResultsThe length of the aerated lung traversed was identified as the most important risk factor for developing pneumothorax, followed by angle of pleural puncture, lesion depth, lesion size, age, procedure time, and sex. The RF model demonstrated better performance in the development and validation datasets when compared with the LR, SVM, and DT based on 15-RFs and 7-RFs. According to DeLong’s test for difference in ROC curves, the RF models based on the 15-RFs and 7-RFs achieved similar classification performance (P>0.05).ConclusionsThis study demonstrated the feasibility of using the 7-RFs RF model for predicting postoperative pneumothorax before patients undergo CT-guided PTNB.

CT‐guided percutaneous epicardial access for ventricular tachycardia ablation: A proof‐of‐concept study

The objective of this study was to evaluate the safety and efficacy of preprocedural computed tomography (CT) to guide percutaneous epicardial puncture for catheter ablation of ventricular tachycardia. A preprocedural CT was used to plan the site, angle, and depth of needle insertion during epicardial access in 10 consecutive patients undergoing ventricular tachycardia (VT) ablation. Adjacent structures (right ventricle, diaphragm, liver, colon, internal mammary artery) were visualized and the course of the needle was planned avoiding these structures. During epicardial access, a protractor was used to guide the angle of needle entry into the subxiphoid space. Postprocedural CT was performed to calculate the deviation between the planned and executed access and to assess for any collateral damage. Percutaneous epicardial access was obtained successfully in all the patients using anterior (n = 4) and inferior (n = 6) approaches. The planned site and angle of puncture was more caudal (2.9 ± 0.9 vs. 3.7 ± 0.7 cm, p = .021) and acute (61.7 ± 5.8 vs. 49.0 ± 5.4°, p = .011) for an anterior approach compared to an inferior approach, respectively. Postprocedure CT revealed minimal deviation of the puncture site (5.4 ± 1.0 mm), angle (5.4 ± 1.2°), and length of needle insertion (0.5 ± 0.2 cm). With regard to the site of entry in the pericardial space, there was a deviation of 5.9 ± 1.1, 6.1 ± 1.1, and 5.8 ± 1.4 mm in the x, y, and z dimensions, respectively. In eight patients with minimal deviation between planned and executed access, there was no collateral injury to adjacent viscera or vessels. In two patients with increased deviation of angle and length of needle insertion, there was entry through the diaphragm during inferior access. Utilizing pre-procedural CT planning may aid in the success and safety of percutaneous epicardial access during VT ablation.

Efficacy and safety of a new disposable percutaneous positioning device invented to facilitate the precision of percutaneous core needle lung biopsies: a prospective, open and randomized controlled study.

BackgroundA new disposable percutaneous positioning device was developed which permits adjustment of the fixing puncture angle while performing a percutaneous core needle lung biopsy (CNLB). The aim of the study was to explore the positioning accuracy and clinical safety of the new device during CT-guided percutaneous CNLB.MethodsA prospective, open and randomized controlled study with two parallel groups was conducted on 150 patients with pulmonary nodules between July 1, 2018 and June 30, 2019 including 101 males and 49 females who were divided (allocation ratio: 1:1) into a standard CNLB group without the percutaneous positioning device (control, n=75) and a new percutaneous positioning device group combined with CNLB (experimental, n=75). The efficacy was determined by the success rate of reaching the target location on the first percutaneous attempt, the number of CT scans performed and the time required for successful puncture positioning. Safety evaluations included complications related to percutaneous surgery and the new positioning device.ResultsThe success rate of reaching the target location on the first percutaneous attempt in the experimental group was significantly higher than in the control group [96.0% (72/75) vs. 42.7% (32/75), P<0.001]. Patients in the experimental group received 3.05±0.28 times CT scans on average for successful percutaneous positioning, which was significantly lower than for the control group (3.95±1.03) (P<0.001). The time required to complete the percutaneous positioning was significantly lower in the experimental group compared to the control group (8.73±3.11 vs. 12.79±4.55 min, P<0.001). There was no significant difference in percutaneous-related complications between the two groups [48.0% (36/75) vs. 61.3% (46/75), P=0.101], except that the bleeding rate in the experimental group was lower than in the control group [26.7% (20/75) vs. 46.7% (35/75), P=0.032].ConclusionsThe use of the optimized percutaneous technology with the new positioning device significantly improved the accuracy and precision of percutaneous lung biopsies.Trial RegistrationChiCTR-INR-17010322.

Extracranial Non-Gasserian Ganglion Application of Radiofrequency Thermocoagulation on the Mandibular Branch of the Trigeminal through the Foramen Ovale for Trigeminal Neuralgia

Percutaneous radiofrequency ablation (RFA) of the trigeminal Gasserian ganglion via the foramen ovale is still one of the classic treatments for primary trigeminal neuralgia. However, the Gasserian ganglion is deep in the middle cranial fossa. Although it is a structure outside the brain tissue, the puncture needle must enter the encephalic to reach the Gasserian ganglion and so it is difficult to completely avoid the risk of intracranial hemorrhage and infection caused by puncture damage to intracranial blood vessels. It is not clear whether if it is possible for RFA at the extracranial non-gasserian-ganglion site via the exit of the cranial channel (foramen ovale) for patients with V3 trigeminal neuralgia (TN). Prospective, clinical research study. Department of Anesthesiology and Pain Medical Center, Jiaxing, China. One hundred and seven patients with isolated mandibular branch trigeminal neuralgia were included. Radiofrequency thermocoagulation was performed by CT-guided percutaneous puncture through the foramen ovale. The puncture target was the midpoint of the horizontal transverse diameter of the oval foramen. If the tingling sensation in the mandibular nerve innervation area could be detected, the radiofrequency thermocoagulation (90°C, 120 sec) under intravenous anesthesia would be performed. We investigated the inclination angle, puncture angle and depth, puncture operation time, intraoperative complications and short-term and long-term results after operation. After radiofrequency thermocoagulation, the pain in the mandibular branch dominant area was completely diminished in 104 patients. Two patients were cured after the second radiofrequency treatment. No intracranial hemorrhage not infection complications occurred, except for facial hematoma during operation in 21 cases. After 12-24 months of follow-up, 9 patients had recurrence and were still effective after receiving additional extracranial radiofrequency treatment. A control group should be established and more clinical data should be collected in future work. Extracranial non-Gasserian-ganglion RF can achieve satisfactory results and improve the safety of radiofrequency treatment for trigeminal neuralgia.

Application of a treatment planning system-assisted large-aperture computed tomography simulator to percutaneous biopsy: initial experience of a radiation therapist.

ObjectiveTo evaluate the application of treatment planning system (TPS)-assisted large-aperture computed tomography (CT) simulator to percutaneous biopsy.MethodsThis retrospective study enrolled patients that underwent TPS-assisted large-aperture CT simulator-guided percutaneous biopsy from November 2018 to December 2019. Retrospective analyses of puncture accuracy were compared using paired t-test and a Wilcoxon rank sum test. The risk factors for puncture accuracy and complications were identified.ResultsA total of 38 patients were included in this study. There were no significant differences between the planned and actual puncture depth and angle. Pulmonary puncture was significantly associated with the accuracy of the puncture angle. The diagnostic rate of malignancy was 76% (29 of 38), of which 20 of 25 patients were in the group initially diagnosed with unconfirmed lesions and nine of 13 patients were in the group of treated patients that needed additional pathological analyses. For patients that underwent a pulmonary biopsy, 12 had minor pneumothorax and three suffered needle track bleeding. No other complications were observed. Regression analyses indicated a significant correlation between puncture angle and the incidence of pneumothorax.ConclusionTPS-assisted large-aperture CT simulator may improve the percutaneous biopsy procedure by combining the advantages of radiotherapy specialties with computer targeting.

Erratum to “Regardless of the Puncture Angle, a Tuohy Needle with Sand-Blasted Steel at the Tip of the Bevel Is a Valid Needle on the Ultrasonic Images”, [Open Journal of Anesthesiology, 2016, 6, 101-104

The original online version of this article (Ichikawa Yuki, Ueshima Hironobu, Hiroshi Otake, Akira Kitamura (2016) Regardless of the Puncture Angle, a Tuohy Needle with Sand-Blasted Steel at the Tip of the Bevel Is a Valid Needle on the Ultrasonic Images, 2016, 6, 101-104, https://file.scirp.org/Html/1-1920418_68780.htm) unfortunately contains some mistakes. The authors wish to correct the errors in co-authors, Table 1, and Table 2.

Distal radial approach: a review on achieving a high success rate.

The transradial approach is the standard for percutaneous coronary intervention (PCI). Moreover, to lead to the evolution of PCI, a new approach site was developed, namely the distal radial approach (dRA). The vessel diameter of the distal radial artery is smaller than that of the forearm radial artery; hence, use of 1 Fr size or a sheath with a thinner outer diameter is recommended. Ultrasound examination before the procedure provides useful information on this matter. There are two approaches to puncture: proximal site puncture of the distal radial artery and distal site puncture. Based on anatomical characteristics, the puncture angle is large on the former and small on the latter. Although a learning curve for the dRA puncture is needed, the use of ultrasound facilitates the process. Using a hemostatic device dedicated to the dRA simplifies observation after PCI. Hemostatic devices for the conventional radial approach or simple bandage with an elastic band can be useful. Usually, less hemostasis time is needed for the dRA compared with the conventional radial approach. Studies have shown high success rates of the dRA (approximately 88-99.5%). Advantages of the dRA are patient comfort, short hemostasis time, less restraint for the patients after PCI, and easy observation at the ward. Disadvantages are the learning curve required for the puncture and the small diameter of the distal radial artery. The dRA is a new approach site for PCI. Further research is warranted for the selection of suitable patients to undergo PCI through the dRA.

Sarcomatoid hepatocellular carcinoma mimicking hepatic abscess

Rationale:Primary sarcomatoid hepatocellular carcinoma (SHC) is a rare subtype of morphologic hepatocellular carcinoma reported on less than 1% of surgical pathology specimens. Herein, we report a rare case of SHC. The case in question was initially misdiagnosed as a liver abscess due to the clinical and radiological similarity between these 2 pathologies. Ultrasound(US)- and contrast-enhanced ultrasound (CEUS)- guided biopsies are helpful in making an accurate diagnosis under the appropriate biopsy area and angle of puncture.Patient concerns:A 56-year old male presented to our hospital with a 2-month history of dull, upper abdominal pain without radiation.Diagnoses:Upon initial investigation with computed tomography, a cystic mass was found in the hepatic V segment and an infectious etiology was presumed. Further diagnostic examination with CEUS and magnetic resonance imaging suggested a hepatic abscess. However, a diagnosis of atypical intrahepatic cholangiocarcinoma was not excluded. The patient received the standard antibiotic treatment without alleviation of his symptoms. Through 3 diagnostic US-and CEUS-guided biopsies over a 3-month period, the pathological diagnosis of SHC was finally confirmed.Interventions:The patient was diagnosed by 3 diagnostic US-and CEUS-guided biopsies, the pathological diagnosis of SHC was finally confirmed.Outcomes:Due to the delay in diagnosis, the patient was not a candidate for surgical resection, and showed dissemination of the lesion to the portal vein. Therefore, treatment with chemotherapy was initiated. After 4 courses of this regimen, tumor progression was found on enhanced magnetic resonance imaging. Therefore, the patient received immunotherapy and targeted therapy with limited response. The patient passed away 3 months later due to tumor progression.Lessons:A hepatic abscess should be considered as a malignant lesion when clinical symptoms do not resolve upon standard treatment. US- and CEUS- guided biopsies are helpful in making an accurate diagnosis under the appropriate biopsy area and angle of puncture.

Robot-guided percutaneous kyphoplasty in treatment of multi-segmental osteoporotic vertebral compression fracture

To evaluate the safety and effectiveness of robot-guided percutaneous kyphoplasty (PKP) in treatment of multi-segmental thoracolumbar osteoporotic vertebral compression fracture (OVCF). A clinical data of 63 cases with multi-segmental thoracolumbar OVCF without neurologic deficit treated with PKP between October 2017 and February 2019 were analyzed retrospectively. The patients were divided into robot-guided group (33 cases) and traditional fluoroscopy group (30 cases). There was no significant difference in gender, age, fracture segment, bone mineral density, and preoperative visual analogue scale (VAS) score, midline vertebral height, and Cobb angle between the two groups ( P>0.05). The time to establish the tunnel, the times of fluoroscopy, the dose of fluoroscopy, the deviation of puncture, the distribution of bone cement, the leakage of bone cement, the puncture angle, and the postoperative VAS score, midline vertebral height, and Cobb angle were recorded and compared. The patients in two groups were followed up 11-13 months (mean, 12 months). Compared with traditional fluoroscopy group, the time to establish the tunnel, the times and dose of fluoroscopy in robot-guided group were significantly lower, the deviation of puncture was slighter, the distribution of bone cement was better, and the puncture angle was larger, the differences between the two groups were significant ( P<0.05). There were 8 segments (9.3%, 8/86) of bone leakage in robot-guided group and 17 segments (22.6%, 17/75) in traditional fluoroscopy group, the difference between the two groups was significant ( χ 2=5.455, P=0.020). There was no significant difference in VAS score, the midline vertebral height, and Cobb angle between the two groups at 2 days after operation and last follow-up ( P>0.05). Robot-guided PKP in treatment of multi-segmental thoracolumbar OVCF can shorten the operation time, improve the accuracy of puncture, reduce the times and dose of fluoroscopy, reduce the leakage of bone cement, and achieve better cement distribution.

Optimal head rotation angle for safe right internal jugular vein catheterization using out-of-plane approach: an ultrasonography study.

The most common complication following internal jugular vein catheterization is the puncture of the common carotidartery. We aimed to find an optimal head rotation angle for safe vein catheter insertion while minimizing the risk of arterypuncture. Eighty-two patients admitted to the intensive care unit were included in the prospective study. Ultrasound examination of the neck vessels on the right side was performed in the neutral position and at a head rotation of 15°, 30°, 45° and 60° to the left. Internal jugular vein and common carotid artery puncture angle, overlapping angle of vein by artery and vein safe puncture angle were evaluated. The internal jugular vein puncture angle increased with head rotation from the neutral position to 30° and 45° and was largest at 60° (p<0.001 for all). The overlapping angle increased significantly at 45° and 60° rotation compared with the neutral position (p<0.001 for all). The vein safe puncture angle was highest at 30° and significantly different from the neutral position and 60° (p=0.003 and p=0.013, respectively). When performing right internal jugular vein catheterization without ultrasound guidance by using an out-of-plane technique, the head should be rotated at 30°, because the overlapping angle increases with further head rotation and can increase the risk of artery puncture.

Ultrasound-Guided Percutaneous Release Procedures in the Lumbar Ligamentum Flavum by Acupotomy: A Cadaveric study.

Objective This study aims to determine the methods of percutaneous release procedures in the lumbar ligamentum flavum (LF) under ultrasound guidance by acupotomy and provide an anatomical basis for intrusive treatment of lumbar disc herniation and lumbar spinal canal stenosis. Methods Twelve cadavers including 4 females and 8 males aged 60 to 90 years (73.42 ± 14.57 years), without formalin fixation, were selected. Guided by an ultrasound transducer, we punctured acupotomy to release lumbar LF in L3/L4, L4/L5, and L5/S1 segments. In the transverse-axis approach, the probe was placed transversely, while in the longitudinal-axis approach, the probe was placed longitudinally. The depth of needle penetration (A), the distance between the puncture point and spinous process (B), and the distance between the puncture point and sacral cornu (C) were measured on cadavers, and the depth of needle penetration (U-A), the distance between the puncture point and spinous process (U-B), and the angle for acupotomy (D) on ultrasound images were also measured. Statistical analyses were carried out using SPSS. Paired sample t-tests and homogeneity of variance tests and one-way analysis of variance (ANOVA) were performed. The Pearson correlation coefficients and linear correlation coefficients were calculated for the data obtained from ultrasound and cadaver measurements. Results No obvious blood vessels and nerves were observed in the puncture path, and the spinal dura was intact. There was no statistical difference between the left and right side measurements obtained from the ultrasound images and the cadavers. The penetration depth in the transverse-axis approach was less than that in the longitudinal-axis approach, and the angle of the needle in the transverse-axis approach was greater than that in the longitudinal-axis approach. The measured data for the transverse-axis approach for L3/L4, L4/L5, and L5/S1 segments showed that there were no differences in the needle angle, the depth of needle penetration, and the distance from the spinous process to the puncture point among the three segments. There was a strong correlation between the depth of needle penetration and the distance from the spinous process to the puncture point on the ultrasonic images and the cadavers on the path of acupotomy. Linear equation A = 2.02 + 0.83 ∗ U-A, R2 = 0.352; B = 1.37 + 0.71 ∗ U-B, R2 = 0.252, where A/B refers to the data measured on the cadavers and U-A/U-B refers to the data measured on the ultrasound images. Conclusion In this study, ultrasound guidance was applied, which better guaranteed the safety and feasibility of acupotomy therapy. Before performing the treatment, the depth of needle penetration in the human body can be determined by measuring the distance between the needle point and the target position on the ultrasound image. Under ultrasound guidance, the transverse-axis approach has a smaller puncture depth and greater puncture angle than the longitudinal-axis approach. Hence, this study believes that the transverse-axis approach is safer for the clinical application of ultrasound-guided LF acupotomy lysis.

Sonographic visibility of cannulas using convex ultrasound transducers.

The key for safe ultrasound (US)-guided punctures is a good visibility of the cannula. When using convex transducers for deep punctures, the incident angle between US beam and cannula varies along the cannula leading to a complex visibility pattern. Here, we present a method to systematically investigate the visibility throughout the US image. For this, different objective criteria were defined and applied to measurement series with varying puncture angles and depths of the cannula. It is shown that the visibility not only depends on the puncture angle but also on the location of the cannula in the US image when using convex transducers. In some image regions, an unexpected good visibility was observed even for steep puncture angles. The systematic evaluation of the cannula visibility is of fundamental interest to sensitise physicians to the handling of convex transducers and to evaluate new techniques for further improvement.