Preprocedural Ultrasound Scan Research Articles

An Audit of Laparoscopic Cholecystectomy.

Objective: Gallstones is a common problem, particularly among women .In modern medicine, uncomplicatedgall stones are usually treated with Laparoscopic Cholecystectomy “Key-hole Surgery” .It carries significantlylower morbidity and mortality as compared to open surgery . At Muhammad Medical College Hospital (MMCH)we have started the procedure in recent years. .Aims: To look into various demographic and clinic aspects of Laparoscopic Cholecystectomy done at MMCH.Methods: Retrospective audit of record of last consecutive 99 patients undergoing Laparoscopic Cholecystectomy at MMCH. Research Ethics Committee approval was obtained (No.250811/REC/003).Results: 33 Men and 66 women underwent this procedure. Average age was 45 year (range 16 to 75). Commonest presenting symptoms were Nausea/vomiting (n=36) and abdominal discomfort /pain (n=36). All patientshad pre-procedure ultrasound scan showing gall stones .At surgery, 99/99 were confirmed to have gallstones .Although 9 also had adhesions, 6 were acutely inflamed and 3 had empyema gall bladder. There were 2conversions Average duration of stay in hospital after procedure was 9 days (range 3 to 20). 2 patients hadwound infection and 3 atelectasis. No mortality was seen.Conclusions: Laparoscopic Cholecystectomy is a safe procedure for gall stones disease.Keywords: Laparoscopic cholecystectomy, conversion rate morbidity.

Ultrasound-assisted lumbar puncture with a horizontal and perpendicular paramedian approach based on positioning in patients with abnormal spinal anatomy: a case report and technical description

BackgroundThe use of ultrasound has been reported to be beneficial in challenging neuraxial procedures. The angled probe is responsible for the main limitations of previous ultrasound-assisted techniques. We developed a novel technique for challenging lumbar puncture, aiming to locate the needle entry point which allowed for a horizontal and perpendicular needle trajectory and thereby addressed the drawbacks of earlier ultrasound-assisted techniques.Case presentationPatient 1 was an adult patient with severe scoliosis who underwent a series of intrathecal injections of nusinersen. The preprocedural ultrasound scan revealed a cephalad probe’s angulation (relative to the edge of the bed) in the paramedian sagittal oblique view, and then the probe was rotated 90° into a transverse plane and we noted that a rocking maneuver was required to obtain normalized views. Then the shoulders were moved forward to eliminate the need for cephalad angulation of the probe. The degree of rocking was translated to a lateral offset from the midline of the spine through an imaginary lumbar puncture’s triangle model, and a needle entry point was marked. The spinal needle was advanced through this marking-point without craniocaudal and lateromedial angulation, and first-pass success was achieved in all eight lumbar punctures. Patient 2 was an elderly patient with ankylosing spondylitis who underwent spinal anesthesia for transurethral resection of the prostate. The patient was positioned anteriorly obliquely to create a vertebral rotation that eliminated medial angulation in the paramedian approach. The procedure succeeded on the first pass.ConclusionsThis ultrasound-assisted paramedian approach with a horizontal and perpendicular needle trajectory may be a promising technique that can help circumvent challenging anatomy. Larger case series and prospective studies are warranted to define its superiority to alternative approaches of lumbar puncture for patients with difficulties.

Establishment of Difficult Caudal Epidural Blockade Prediction Model.

We aimed to develop a predictive difficult caudal epidural blockade (pDCEB) model when ultrasound was not available and verified the role of ultrasound in difficult caudal epidural blockade (CEB). From October 2018 to March 2019, this study consisted of three phases. First, we prospectively enrolled 202 patients scheduled to undergo caudal epidural anesthesia and assessed risk factors by binary logistic regression to develop the predictive scoring system. Second, we enrolled 87 patients to validate it. The receiver operating characteristic (ROC) curve was used to evaluate the performance of the prediction model. Youden-index was used to determine the cut-off value. Third, we enrolled 68 patients with a high risk of difficult CEB (pDCEB score ≥3) and randomized them into ultrasound and landmark groups to verify the role of ultrasound. The rate of difficult CEB was 14.98% overall 289 patients. We found a correlation between unclear palpation of the sacral hiatus (OR 9.688) and cornua (OR 4.725), the number of the sacral hiatus by palpation ≥1 (OR 4.451), and history of difficult CEB (OR 39.282) with a higher possibility of difficult CEB. The area under the receiver operating characteristic curve of the pDCEB model involving the aforementioned factors was 0.889 (95% CI, 0.827-0.952) in the development cohort and 0.862 (95% CI, 0.747-0.977) in the validation cohort. For patients with a pDCEB score ≥3, a preprocedure ultrasound scan could reduce the incidence of difficult CEB (55.56% in the Landmark group vs. 9.38% in the ultrasound group, p < 0.001). This novel pDCEB score, which takes into account palpation of the sacral hiatus/cornua, number of the sacral hiatus by palpation ≥1, and history of difficult CEB, showed a good predictive ability of difficult CEB. The findings suggested that performing an ultrasound scan is essential for patients with a pDCEB score ≥3. Trial registration: No: ChiCTR1800018871, Site URL: https://www.chictr.org.cn/edit.aspx?pid=31875&htm=4; Principal investigator: Jialian Zhao, Date of registration: 2018.10.14.

6: Pre-procedural ultrasonography as an adjunct to landmark technique for identification of epidural space in parturients coming for labour analgesia- a prospective randomised controlled trial.

Background and Aims:Pregnancy-induced softening of tissues and ligaments, may increase the false-positive rate when identifying the epidural space by the loss of resistance ( LOR ) technique. Ultrasonography (USG), which has now become the EYE of anesthesiologists, can be used as a reliable tool to facilitate epidural needle placement in parturients. The objectives of the study included finding out the correlation between USG guided estimated depth versus actual depth of epidural space in parturients.Number of attempts taken and incidence of dural punctures by landmark technique versus USG guided technique were the secondary objectivesMethods:After the approval from the institutional ethics committee and Clinical Trials Registry of India registration, 62 parturients of American Society of Anesthesiologists(ASA) II requesting labor analgesia were randomised into two groups of 31 each- GROUP-L (conventional landmark technique) and GROUP-U (preprocedural ultrasound scan done before epidural).In group-U, Tuohy needle was introduced through the USG pre-determined insertion point and epidural space was located using LOR technique.Results:Ultrasound increased the success rate of epidural at first attempt from 51.6% in group “L” to 87% in group “U” Fewer needle attempts (P value - 0.001) were required in group “U” as compared to group “L”.No accidental dural punctures in group U, compared to 6 in group-L.Mean depth of epidural space (cm)-UD= 3.89 ± 0.45 cm and ND=4.05±0.37 cm. Conclusion:Pre-procedural ultrasonography is a simple, safe and accurate tool to determine the needle insertion site, decrease the incidence of accidental dural punctures and helps to assess epidural space depth in parturients.Group LGroup U P Mean of total no. of attempts1.73±0.891.13±0.590.001No. of attempts First attempt16 (51.6%)27 (87%)0.002 Second attempt10 (32.2%)4 (12.9%) >2 attempts5 (16.1%)0Accidental dural puncture60

Preprocedural ultrasound for neuraxial blockade in nonobstetric patients. Should it be considered as a standard of care?

Preprocedural ultrasound for neuraxial blockade in nonobstetric patients. Should it be considered as a standard of care?

Pre-Procedural Lumbar Neuraxial Ultrasound-A Systematic Review of Randomized Controlled Trials and Meta-Analysis.

A pre-procedural ultrasound of the lumbar spine is frequently used to facilitate neuraxial procedures. The aim of this review is to examine the evidence sustaining the utilization of pre-procedural neuraxial ultrasound compared to conventional methods. We perform a systematic review of randomized controlled trials with meta-analyses. We search the electronic databases Medline, Cochrane Central, Science Direct and Scopus up to 1 June 2019. We include trials comparing a pre-procedural lumbar spine ultrasound to a non-ultrasound-assisted method. The primary endpoints are technical failure rate, first-attempt success rate, number of needle redirections and procedure time. We retrieve 32 trials (3439 patients) comparing pre-procedural lumbar ultrasounds to palpations for neuraxial procedures in various clinical settings. Pre-procedural ultrasounds decrease the overall risk of technical failure (Risk Ratio (RR) 0.69 (99% CI, 0.43 to 1.10), p = 0.04) but not in obese and difficult spinal patients (RR 0.53, p = 0.06) and increase the first-attempt success rate (RR 1.5 (99% CI, 1.22 to 1.86), p < 0.0001, NNT = 5). In difficult spines and obese patients, the RR is 1.84 (99% CI, 1.44 to 2.3; p < 0.0001, NNT = 3). The number of needle redirections is lower with pre-procedural ultrasounds (SMD = −0.55 (99% CI, −0.81 to −0.29), p < 0.0001), as is the case in difficult spines and obese patients (SMD = −0.85 (99% CI, −1.08 to −0.61), p < 0.0001). No differences are observed in procedural times. Ιn conclusion, a pre-procedural ultrasound provides significant benefit in terms of technical failure, number of needle redirections and first attempt-success rate. Τhe effect of pre-procedural ultrasound scanning of the lumbar spine is more significant in a subgroup analysis of difficult spines and obese patients.

Iliac vein pathology and short-term stenting outcomes in a South-East Asian population: A single-centre experience.

Current literature regarding iliofemoral intervention and stenting is mostly based on Western populations. We present our experience of iliofemoral stenting for chronic venous disease within a South-East Asian population. This is a single-centre retrospective review of a prospectively collected registry. Seventy-one patients with 105 limbs underwent iliac vein IVUS and stenting between 2016 and 2019. All patients underwent pre-procedure ultrasound venous scan and MRI venogram. Pre- and post-operative CEAP classification, Villalta score and Venous Clinical Severity Score (VCSS), technical results, stent patency rates and complication rates are documented. Seventy-six per cent of the cases are non-thrombotic iliac vein lesion, and 68% of patients have C4 to C6 disease. Ten percentage of patients had acute thrombosis on presentation. There was 100% technical success. A 6- and 7-point reduction in the mean VCSS and Villalta score, respectively, were noted post-stenting (baseline of 10 points and P<0.001 in both categories). Post-stenting ulcer healing rate was 91% at 6 and 12months. One-year ulcer recurrence and cellulites recurrence were at 8% and 7%, respectively. One unplanned 30-day readmission (not related to procedure) and no 30-day mortality were noted. Bleeding complication from anticoagulation was 3%. There was 10% in-stent non-flow limiting stenosis on surveillance. One-year primary patency was 91%, and secondary patency was 100%. Within our series, iliofemoral stenting has 100% technical success, with statistically significant reduction in VCSS and Villalta score, good wound healing rates, low ulcer and cellulites recurrence and good primary and secondary patency rates at 1year.

Evaluation of the factors related to difficult ultrasound-guided radial artery catheterization in children under two years old: a prospective observational study

Introduction Although ultrasound guidance has significantly improved the success rate of radial artery catheterization, the failure rate in small children is still high. For the further improvement of success rate, we prospectively evaluated the factors that make ultrasound-guided radial artery catheterization difficult in small children under two years old. Methods From October 2018 to September 2019, patients under two years old who required radial artery catheterization for surgery were enrolled. After collecting the anatomical characteristics of the radial artery using ultrasound at the puncture site, ultrasound-guided radial artery catheterization was performed by one experienced anesthesiologist and recorded as a movie clip for further analysis. The primary outcome was to identify the factors related to the first attempt failure. The factors associated with the total duration of the procedure until success were also evaluated. Results A total of 183 children were included in the analysis. A radial artery cross-sectional area of 1 mm2 or less (OR [95% CI]: 5.26 [2.48–11.18], P Discussion A radial artery cross-sectional area of 1 mm2 or less, and the presence of an anomalous radial artery branch significantly increased the difficulty of ultrasound-guided radial artery catheterization in small children under two years old. In patients of these ages, pre-procedural ultrasound scanning to find an optimal site for catheterization may increase the first-attempt success rate. However, further studies are needed to verify the usefulness of pre-procedural scanning.

Evaluation of the factors related to difficult ultrasound-guided radial artery catheterization in small children: A prospective observational study.

Although ultrasound guidance has significantly improved the success rate of radial artery catheterization, the failure rate in children is still high. For the further improvement of success rate, we prospectively evaluated the factors that make ultrasound-guided radial artery catheterization difficult in children under two years old. From October 2018 to September 2019, patients who required radial artery catheterization for surgery were enrolled. After collecting the anatomical characteristics of the radial artery using ultrasound at the puncture site, ultrasound-guided radial artery catheterization was performed by one experienced anaesthesiologist. The primary outcome was to identify the factors related to the first attempt failure. The factors associated with the total duration of the procedure until success were also evaluated. A total of 183 children were included in the analysis. A radial artery cross-sectional area of ≤1mm2 (odds ratio [OR]=5.26; 95% confidence interval [CI], 2.48-11.18; P<.0001) and the presence of an anomalous radial artery branch (OR=3.37; 95% CI, 1.43-7.95; P=.005) were independent predictors of first-attempt failure during ultrasound-guided radial artery catheterization. The total procedure time was also negatively associated with the small cross-sectional area (P<.001). A cross-sectional area of ≤1mm2 and the presence of an anomalous branch of radial artery significantly increased the difficulty of ultrasound-guided radial artery catheterization in children under two years old. In patients of these ages, pre-procedural ultrasound scanning to find an optimal site for catheterization may increase the first-attempt success rate although further studies are needed to verify our results. Clinical Research Information Service (https://crits.nih.go.kr, October 6, 2018 [KCT0003239]; Principle investigator: Jong-Hwan Lee).

Preprocedural Ultrasound Estimates of Epidural Depth: Transverse Median Plane is Comparable to Paramedian Sagittal Oblique Plane in Non-Pregnant Patients

ObjectiveThe aim of this study was to assess the accuracy and precision of the actual epidural depth (ND) and ultrasound (US) estimates of the distance from the skin to the epidural space in the transverse median plane (ED/TM) and paramedian sagittal oblique plane (ED/PSO) in patients who were not pregnant and who were undergoing unilateral inguinal hernia repair surgery under combined spinal epidural anaesthesia.MethodsA total of 100 patients with the American Society of Anaesthesiology status I–III of either gender were recruited. All epidurals were inserted at the L3–4 intervertebral space, and the epidural needle was marked with a sterile marker. The ND was measured between the marker and the tip of the needle. The ED/TM and ED/PSO were assessed with a 2–5 MHz curved array probe at the L3–4 intervertebral space. The Pearson correlation coefficient and Lin’s concordance correlation coefficient were used to assess the precision and the Bland–Altman test was used to assess the 95% limit of agreement.ResultsThe ND was 48.98±6.91 mm, the ED/PSO was 48.92±6.91 mm and the ED/TM was 48.90±6.91 mm. The Pearson correlation coefficient between ND and ED/PSO was 0.995 (p<0.001) and 0.994 (p<0.001) with ED/TM. Lin’s concordance correlation coefficient for ND and ED/PSO was 0.995 (95%CI [confidence interval]: 0.992–0.997), and 0.993 for ND and ED/TM (95% CI: 0.990–0.996). The 95% limit of agreement between ND and ED/PSO was 0.70–1.37, and for ND and ED/TM, it was 0.79–1.54.ConclusionPreprocedural ultrasound (US) scanning in both planes provides reliable estimates for actual epidural depth in non-pregnant patient population.

Preprocedural ultrasound versus landmark techniques for spinal anesthesia performed by novice residents in elderly: a randomized controlled trial

BackgroundSpinal anesthesia using the midline approach might be technically difficult in geriatric population. We hypothesized that pre-procedural ultrasound (US)-guided paramedian technique and pre-procedural US-guided midline technique would result in a different spinal anesthesia success rate at first attempt when compared with the conventional landmark-guided midline technique in elderly patients.MethodsIn this prospective, randomized, controlled study, one hundred-eighty consenting patients scheduled for elective surgery were randomized into the conventional surface landmark-guided midline technique (group LM), the pre-procedural US-guided paramedian technique (group UP), or the pre-procedural US-guided midline technique (group UM) with 60 patients in each group. All spinal anesthesia were performed by a novice resident.ResultsThe successful dural puncture rate on first attempt (primary outcome) was higher in groups LM and UM (77 and 73% respectively) than in group UP (42%; P < 0.001). The median number of attempts was lower in groups LM and UM (1 [1] and 1 [1–1.75] respectively) than in group UP (2 [1, 2]; P < 0.001). The median number of passes was lower in groups LM and UM (2 [0.25–3] and 2 [0–4]; respectively) than in group UP (4 [2–7.75]; P < 0.001). The time taken to perform the spinal anesthesia was not different between groups LM and UM (87.24 ± 79.51 s and 116.32 ± 98.12 s, respectively) but shorter than in group UP (154.58 ± 91.51 s; P < 0.001).ConclusionsA pre-procedural US scan did not improve the ease of midline and paramedian spinal anesthesia as compared to the conventional landmark midline technique when performed by junior residents in elderly population.Trial registrationRetrospectively registered at Clinicaltrials.gov, registration number NCT02658058, date of registration: January 18, 2016.

A randomized comparison between Accuro and palpation-guided spinal anesthesia for obese patients undergoing orthopedic surgery

BackgroundAlthough obese patients benefit from neuraxial anesthesia, technical difficulties often discourage its use. The current randomized trial compared Accuro, a hand-held, battery-operated ultrasound (US) device, and conventional palpation for spinal...

A Systematic Ultrasound Evaluation of the Diameter of Deep Veins in the Newborn: Results and Implications for Clinical Practice

Background: In adults and children, current guidelines recommend measuring the diameter of the vein before the insertion of central catheters, in order to match vein diameter with catheter caliber and thus reduce the risk of venous thrombosis. In the neonatal intensive care unit, central catheters are often used but the vein diameter is usually not considered. Method: We assessed the diameter of the most relevant deep veins in 100 newborns, using a strict protocol of ultrasound evaluation. Results: Mean gestational age of studied infants was 32 weeks and mean weight was 1,690 g. The mean diameter of the brachiocephalic vein was consistently ≥3 mm, with no significant difference between the right and the left side. The femoral vein diameter, on the other hand, was considerably smaller than 3 mm for infants with a weight < 2,000 g. Interobserver repeatability was found to be very high. Conclusion: Preprocedural ultrasound scan of veins is feasible and easy, also in newborns, and it should be recommended for optimizing central venous catheterization.

Preprocedural ultrasound as an adjunct to blind conventional technique for epidural neuraxial blockade in patients undergoing hip or knee joint replacement surgery: A randomised controlled trial.

Background and Aims:The patients undergoing total knee and hip replacement surgeries are mostly obese, more than 50 years of age with osteophytic spine and spine deformities making the blind conventional technique of regional anaesthesia more difficult. The aim of the study was to compare the role of preprocedural ultrasound scan to conventional blind technique in obese patients with osteophytic spines undergoing total knee or hip replacement surgeries in terms of technical difficulty, clinical efficacy, safety and patient comfort.Methods:A prospective, randomised controlled trial was conducted in which 210 consenting American Society of Anesthesiologists (ASA) grade III patients, age >50 years, Body Mass Index (BMI) ≥30 kg/m2 with osteophytic spines including abnormalities undergoing joint replacement surgeries were randomised in two groups. Ultrasound group (“B”) received Combined Spinal Epidural Anaesthesia (CSEA) after preprocedural lumbar ultrasound scan. In control group (“A”), CSEA was given by blind conventional technique. The primary objective was to compare the rate of successful epidural block on 1st needle insertion attempts in both the groups. The secondary objectives were to compare both groups in terms of ease, success, comfort and safety of epidural block.Results:Ultrasound improved success of CSEA at 1st attempt from 74.3% in control group (“A”) to 85.7% in Ultrasound group (“B”) (P = 0.038). Fewer needle insertion attempts, passes and anaesthesiologist were required in ultrasound group. Pearson correlation coefficient was 0.976 using both views.Conclusion:Preprocedural ultrasound scan is a useful adjunct to lumbar epidural blocks in obese patients with osteophytic abnormal spines.

Recent developments in ultrasound imaging for neuraxial blockade.

Recent research has shed further light on the place of ultrasound imaging in neuraxial blockade in routine clinical practice, its use in thoracic epidurals, and real-time ultrasound-guided techniques. Compared with the conventional technique of surface landmark palpation, preprocedural ultrasound imaging minimizes technical difficulty associated with lumbar neuraxial blockade in patients with poor-quality surface landmarks. Novice practitioners are able to learn to employ the technique effectively. Safety benefits include a reduction in postprocedural back pain associated with fewer needle passes and a lower risk of procedure-associated bleeding. The advantage of ultrasound is minimal however in patients with easily discernible surface landmarks, especially if the practitioner is highly experienced. Recent trials show that preprocedural ultrasound scanning for thoracic epidural insertion reduces needle punctures and increases early analgesic efficacy compared with the palpation technique. Real-time ultrasound-guided techniques, while feasible, remain challenging and may not offer significant benefit over preprocedural imaging in lumbar neuraxial blockade. Their role in thoracic epidural insertion requires further investigation. Ultrasound imaging of the spine is a valuable technique that, while not indicated for routine use, should be part of the skillset of any practitioner that regularly performs lumbar and thoracic neuraxial blockade.

Lumbar epidural depth using transverse ultrasound scan and its correlation with loss of resistance technique: A prospective observational study in Indian population.

Background and Objectives:The objective of the present study was to evaluate the skin-epidural space distance as assessed by ultrasonography and conventional loss of resistance (LOR) technique and to find the correlation of epidural depth with body mass index (BMI).Methods:Ninety-eight patients of either sex, American Society of Anesthesiology I/II, BMI <30 kg/m2 requiring lumbar epidural for surgery were enrolled. The epidural space was assessed with a curvilinear ultrasound (US) probe, 2–5 MHz, in the transverse plane at L3–L4 intervertebral space. Thereafter, the epidural depth from skin was assessed with conventional LOR method while performing the epidural. The needle depth (ND) was measured using a sterile linear scale, and any change in the needle direction or intervertebral space was noted.Results:The patients were demographically similar. Depth of epidural space measured by US depth (UD) was 3.96 ± 0.44 cm (range 3.18–5.44 cm) and by ND was 4.04 ± 0.52 cm (range 2.7–5.7 cm). The Pearson's correlation coefficient (r) between UD and ND was 0.935 (95% confidence interval: 0.72–0.92, r2 = 0.874, P < 0.001), and Bland–Altman analysis revealed the 95% limits of agreement −0.494–0.652 cm.Conclusion:The present study demonstrates a good correlation between UD and ND and shows that the preprocedural US scan in transverse plane provides accurate needle entry site with a high success rate in single attempt for lumbar epidurals in patients with a BMI <30 kg/m2.

Ultrasound to Identify the Lumbar Space in Women With Impalpable Bony Landmarks Presenting for Elective Caesarean Delivery Under Spinal Anaesthesia: A Randomized Trial

(Int J Obstet Anesth. 2016;28:12–16) The use of ultrasound-guided spinal anesthesia for cesarean delivery in patients with spinous processes that are difficult or impossible to palpate is gaining in popularity. The main aim of this study was to determine whether preprocedural ultrasound scanning would make it easier to locate an appropriate needle insertion point and thereby improve the performance of spinal anesthesia for elective cesarean delivery in patients with impalpable bony landmarks.

Http://www.medultrason.ro/ultrasound-in-the-examination-of-the-gallbladder-a-holistic-approach-grey-scale-doppler-ceus-elastography-and-3d/

Neuraxial blockade is still largely performed as a blind procedure. Despite of developments in the type of needles used and drugs administered, the process of locating the epidural or intra-thecal space is still limited to identification of landmarks by palpation and reliance on tactile feedback of the operator. Ultrasound has provided the long needed "eye" to the procedure and has already shown promise of improving the safety and efficacy or neuraxial blocks. This review focuses on understanding the sonoanatomy of the neuraxial space, performing a systematic pre-procedural ultrasound scan, and reviewing the available evidence.

A Randomised Controlled Trial of Ultrasound-Assisted Spinal Anaesthesia

Pre-procedural ultrasound scanning has been used to facilitate spinal anaesthesia in patients with difficult anatomical landmarks and shown to improve first-attempt success rates in some studies. We studied whether pre-procedural ultrasound scanning improved first-attempt success rate and decreased time taken for the procedure in the general adult population. In this prospective, randomised controlled trial, 170 American Society of Anesthesiologists 1 to 3 patients aged between 21 and 80 years were recruited. Informed consent was obtained. Patients were randomised into two groups, ultrasound-guided identification of landmarks (Ultrasound Group) and manual palpation of landmarks (Manual Palpation Group). The primary outcome was first-attempt success rate and secondary outcomes were time taken to perform procedure, number of needle redirections, patient satisfaction and complications. The first-attempt success rate was 64% in the Ultrasound Group and 52% in the Manual Palpation Group (P=0.16). Time taken for procedure was shorter in the Ultrasound Group compared to the Manual Palpation Group (2.9±3.6 minutes versus 3.9±3.7 min, P= 0.007). Patient satisfaction was higher in the Ultrasound Group. There were no differences in complications. As there was no statistically significant difference in first-attempt success rates between the two groups, existing evidence for routine pre-procedural scanning for all patients is inadequate. The current use of pre-procedural ultrasound scanning will probably be limited to selected patients where spinal anaesthesia may be technically challenging with conventional methods.

Guidewire advancement is interrupted by an internal jugular vein valve with a restricted opening: an ultrasound image

To the Editor, Anesthesiologists have generally paid relatively little attention to the internal jugular vein valve (IJVV) during central venous catheter insertion. Interruption of guidewire insertion by the IJVV is known to occur; however, very few related images appear in the published literature. Recently, a 73-yr-old male with a bicuspid aortic valve and a history of hypertension presented to our hospital for aortic valve replacement. Following induction of anesthesia, we attempted an ultrasound-guided placement of the Sheath Introducer (Multi-lumen access catheter, ARROW ) into the patient’s right internal jugular vein (IJV). We rotated the patient’s head to the left while slightly extending his neck, and we then confirmed that the IJV was lying parallel to the right carotid artery which had no evidence of stenosis. Ultrasound imaging was used to confirm the location of the needle tip within the vessel and backflow of blood. Next, we attempted to introduce a guidewire into the right IJV; however, we were unable to advance the guidewire more than 8 cm due to resistance. During ultrasound-guided indwelling of the guidewire, a large membranous structure was detected protruding from the posterior wall of the IJV. Although we attempted to advance the guidewire with the assistance of ultrasound imaging, the wire could only push the bottom of membranous structure (Figure, Panel A). The guidewire was caught by the membranous structure, and we could not advance the wire further. After several failed attempts, we placed the Sheathe Introducer into the left IJV instead. Internal jugular vein valves are the only barrier between the brain and the heart that prevent retrograde venous blood flow when the intrathoracic pressure increases. Malfunction of the IJVV may include restriction of the opening and valve incompetence. As was the case here, a restricted opening may impede insertion of the catheter or guidewire during central venous catheterization, while valve incompetence may be a complication of catheterization. A guidewire is introduced along the posterior wall of the IJV. In this case, the patient’s IJVV was a bicuspid valve which consisted of a large posterior leaflet and a small anterior leaflet. Advancement of the guidewire was obstructed by the bottom of the posterior leaflet with a restricted opening. Based on our experience, we suggest assessing any malfunctioning opening movement of the IJVV with a preprocedural ultrasound scan. Macchi et al. reported that IJVV incompetence may be considered a normal finding; however, a pressure gradient develops in this valve during coughing. Catheterization of the IJV involves a risk of injury to the IJVV. Wu et al. reported that IJVV incompetence is more commonly caused by cannulation and catheterization at the proximal site of the IJV than at the distal site. Internal jugular vein valve incompetence causes an increase in retrograde