Traditional Anatomic Landmark Research Articles

Transseptal puncture using electroanatomical mapping: a safe and cost-effective technique

Abstract Background The usual technique of transseptal puncture (TSP) uses fluoroscopy or intracardiac echocardiography. New techniques for oval fossa (OF) identification by electroanatomical mapping (EAM) have been described. However, the technique of direct visualization of the TSP needle added to the OF location by impedance mapping has not been investigated yet. Purpose To evaluate feasibility and safety of the TSP technique guided by the interatrial septum (IAS) impedance mapping and the TSP needle visualization using EAM system. Methods Consecutive patients who underwent ablation using TSP in July and August 2022 in our institute were included. The standard material for the procedure was used in addition to a temporary pacemaker (PM) connection cable. In all cases, the EAM system was CARTO 3 version 7 (Biosense Webster and a bipolar voltage map of right atrium and a impedance map of the IAS were constructed. The OF location was estimated based on the septal region with the lowest impedance and on traditional anatomical landmarks. Using a temporary PM cable connected to the proximal part of the TSP needle stylet, it was possible to visualize its distal portion on the 3D map used to guide the TSP. The entire process was simultaneously monitored under fluoroscopic visualization by an experienced professional. Results A total of 25 patients were included; mean age of 56 +/- 15 years, 16 (64%) were male. The most frequent procedure was atrial fibrillation ablation (86%); left atrium mean size of 40,26 +/- 5,2 mm. 9 patients (36%) were already submetted to a previous procedure using TSP. None of the patients had congenital heart disease. In all cases, the TSP was successfully performed and a correlation between the anatomical references and the lowest impedance region on the map was observed. There were no complications. Conclusion The technique of visualization of the TSP needle using EAM system added to IAS impedance mapping and use of anatomical markers seems to be a safe and cost-effective alternative for performing TSP. This technique could reduce ionizing radiation without need for additional materials.Impedance map and bipolar voltage mapLA (bipolar voltage map) and TSP orifice

Use of computer navigation and robotics in adult spinal deformity

Recent years have seen significant advancements in the implementation of computer-assisted surgery in spine. Enabling technologies like robots and navigation have been refined to compliment the field's shift towards minimally invasive techniques and to fit more seamlessly into the existing workflow. Robotic-surgery and navigation in deformity can be particularly helpful in cases where the severe curves of the spinal column or the abnormal pedicle anatomy make pedicle screw placement challenging with the use of traditional anatomic landmarks. Furthermore, the ability to pre-plan patient specific rods has opened the door for greater precision in rod contouring. Drawbacks of robotic-assisted surgery include the steep upfront cost, the need for additional staff and training and the lack of tactile feedback. This review will discuss the current state of navigation and robotics, with a specific focus on their applications to deformity surgery.

Catheter Ablation of Atrioventricular Nodal Reentrant Tachycardia in Patients With Congenital Heart Disease.

Atrioventricular (AV) nodal reentrant tachycardia represents the most common regular supraventricular arrhythmia in humans, and catheter ablation of the so called slow AV nodal pathway has been effectively performed for decades. In patients with congenital heart disease, a combination of different factors makes catheter ablation of AV nodal reentrant tachycardia substrate particularly challenging, including abnormal venous access to intracardiac structures, abnormal intracardiac anatomy, potentially deviant and often unpredictable sites of the specific conduction system, loss of traditional anatomic landmarks, and congenital cardiac surgery that may complicate the access to the AV nodal area. Published experiences have confirmed the efficacy and the relative safety of such procedures when performed by experts, but the risk of complications, in particular AV block, remains non-negligible. A thorough knowledge and understanding of anatomic and electrical specificities according to underlying phenotype are essential in addressing these complex cases. Considering the major consequences associated with AV block in patients with complex congenital heart disease, particularly those without low risk access for transvenous ventricular pacing (eg, single ventricle physiology or Eisenmenger syndrome), the individual risk-benefit ratio should be carefully evaluated. The decision to defer ablation may be the wisest approach in selected patients with either infrequent or hemodynamically tolerated arrhythmias, or when the location of the AV conduction pathways remains uncertain. This narrative review aims to synthetize existing literature on catheter ablation of AV nodal reentrant tachycardia in congenital heart disease, to present main features of common associated pathologies, and to discuss approaches to mapping and safely ablating the slow AV nodal pathway in challenging cases.

Preprocedure ultrasound imaging combined with palpation technique in epidural labor analgesia.

BACKGROUNDFor parturients with paroxysmal uterine contraction pain, rapid analgesia is needed. We used preprocedure ultrasound imaging combined with the palpation technique in epidural analgesia for labor, and evaluated the usefulness of this technique in epidural labor analgesia.AIMTo evaluate the usefulness of preprocedure ultrasound imaging in epidural analgesia for labor.METHODSIn this prospective randomized observational study, 72 parturients were assigned to two groups (combined or palpation group). The target interspace of all parturients was first identified by the palpation technique. Then in the combined group, preprocedure ultrasound imaging was used before epidural puncture. In the palpation group, only the traditional anatomical landmarks technique (palpation technique) was performed. The primary outcome was total duration of the epidural procedure (for the ultrasound group, the duration of the preprocedure ultrasound imaging was included). The secondary outcomes were the number of skin punctures, the success rate at first needle pass, the number of needle passes, the depth from the skin to epidural space, and the complications of the procedure.RESULTSTotal duration of the epidural procedure was similar between the two groups (406.5 ± 92.15 s in the combined group and 380.03 ± 128.2 s in the palpation group; P = 0.318). A significant improvement was demonstrated for epidural puncture and catheterization in the combined group. The number of needle passes was 1.14 in the combined group and 1.72 in the palpation group (P = 0.001). The number of skin puncture sites was 1.20 in the combined group and 1.25 in the palpation group (P = 0.398). The success rate at first needle pass was 88.89% in the combined group and 66.67% in the palpation group (P = 0.045).CONCLUSIONThis study demonstrated that the total duration of epidural procedures with preprocedure ultrasound imaging combined with the palpation technique was not longer than the traditional anatomical landmarks technique, which were performed by six experienced anesthesiologists in parturients with normal weights undergoing labor analgesia.

Current state of navigation in spine surgery.

The use of navigation has become more prevalent in spine surgery. The multitude of available platforms, as well as increased availability of navigation systems, have led to increased use worldwide. Specific subsets of spine surgeons have incorporated this new technology in their practices, including minimally invasive spine (MIS) spine surgeons, neurosurgeons, and high-volume surgeons. Improved accuracy with the use of navigation has been demonstrated and its use has proven to be a safe alternative to fluoroscopic guided procedures. Navigation use allows the limitation of radiation exposure to the surgeon during common spine procedures, which over the course of a surgeon’s lifetime may offer significant health benefits. Navigation has also been beneficial in tumor resection and MIS surgery, where traditional anatomic landmarks are missing or in the case of MIS not visible. As cost effectiveness improves, the use of navigation is likely to continue to expand. Navigation will also continue to expand with further innovation such as coupling the use of navigation with robotics and improving tools to enhance the end user experience.

Flexion Space Balancing Through Component Positioning and Its Relationship to Traditional Anatomic Rotational Landmarks in Robotic Total Knee Arthroplasty

BackgroundThe use of the femoral component position to balance the flexion space and its relationship to the transepicondylar axis (TEA) and posterior condylar angle (PCA) has not been thoroughly evaluated. MethodsA total of 233 patients undergoing robotic arm–assisted total knee arthroplasty were evaluated. Native TEA and PCA were established on preoperative computed tomography scans. Femoral component rotation was set in the axial plane to match the native trochlea and native medial femoral condyle to set the flexion gap. Knee flexion space gaps and component position were recorded. The relationship of the femoral component to the native TEA, PCA, and preoperative radiographic landmarks was evaluated. ResultsThe intraoperative measured medial flexion space gap did not significantly correlate with the relationship of the femoral component to the PCA or TEA in varus or valgus knees. In varus knees, the preoperative mechanical axis alignment had a positive relationship to femoral component position when compared to the PCA (P = .04) and TEA (P = .002). In valgus knees, there was a positive correlation between the preoperative lateral distal femoral angle and component position when compared to the PCA (P = .04) only. ConclusionIntraoperative measured flexion space balance through femoral component positioning did not correlate with its relationship to the native TEA or PCA. In varus knees, the preoperative mechanical axis alignment correlated with an increase in femoral component external rotation to the TEA and PCA. In valgus knees, the severity of preoperative lateral distal femoral angle correlated with the rotational relationship of the femoral component to the PCA only.

Signal intensity of perirolandic cortex identifies the central sulcus on double inversion recovery MRI.

Identification of the central sulcus can require inspection of subtle differences or require certain pulse sequences. This study identifies the central sulcus by signal intensity on double inversion recovery (DIR) images in multiple anatomic locations and imaging planes. Forty-nine patients (98 hemispheres) were retrospectively reviewed by three neuroradiologists and one radiology resident. The central sulcus was compared to the surrounding sulci for differences in signal intensity at axial hand knob, axial operculum, and lateral convexity sagittal images (294 locations) on DIR images. The use of the "disappearing central sulcus sign" where the window level is increased at constant width and black/white inversion were also assessed. In 49 patients (22 females, 27 males; median age 36 years), the central sulcus cortex signal intensity was lower than adjacent sulci with a frequency of 90/98 (91.8%) at the axial hand knob level, 68/98 (69.4%) at the axial operculum level, and 76/98 (77.5%) at the sagittal level. With black and white inversion, the frequencies were of 96/98 (98%), 92/98 (94%), and 87/98 (89%). The central sulcus was the first to disappear at all three levels with high degrees of inter-reader agreement (86-99%). Traditional anatomic landmarks were absent or conflicting in seven hemispheres (5 patients). The central sulcus was identified by DIR signal intensity in all seven hemispheres. The central sulcus can be identified by differences in signal intensity of the perirolandic cortex on DIR. Use of black/white inversion and the disappearing central sulcus sign may further facilitate identification.

The Inaccuracy of Surface Landmarks for the Anterior Approach to the Cervical Spine in Southern Chinese Patients.

Study DesignObservational study.PurposeTo assess the correlational accuracy between the traditional anatomic landmarks of the neck and their corresponding vertebral levels in Southern Chinese patients.Overview of LiteratureRecent studies have demonstrated discrepancies between traditional anatomic landmarks of the neck and their corresponding cervical vertebra.MethodsThe center of the body of the hyoid bone, the upper limit of the lamina of the thyroid cartilage, and the lower limit of the cricoid cartilage were selected as representative surface landmarks for this investigation. The corresponding vertebral levels in 78 patients were assessed using computed tomography.ResultsIn both male and female patients, almost none of the anatomical landmarks demonstrated greater than 50% correlation with any vertebral level. The most commonly corresponding vertebra of the hyoid bone, the lamina of the thyroid cartilage, and the cricoid cartilage were the C4 (47.5%), C5 (35.9%), and C7 (42.3%), respectively, which were all different from the classic descriptions in textbooks. The vertebral levels corresponding with the thyroid and cricoid cartilage were significantly different between genders.ConclusionsThe surface landmarks of the neck were not accurate enough to be used as the sole determinant of vertebral levels or incision sites. Intra-operative fluoroscopy is necessary to accurately locate each of the cervical vertebral levels.

Use of Two-Dimensional Ultrasonographically Guided Access to Reduce Access-Related Complications for Transcatheter Aortic Valve Replacement

BackgroundMajor vascular complications have been associated with increased mortality and morbidity in patients undergoing transcatheter aortic valve replacement (TAVR). Our objective was to compare vascular and bleeding outcomes with the routine use of 2-dimensional ultrasonography (2D-US) guided femoral artery access in percutaneous transfemoral TAVR compared with traditional anatomic landmark palpation with angiographically-guided access. MethodsThis single-centre retrospective cohort study was conducted in Ontario, Canada. We enrolled patients from January 1, 2012-June 30, 2016. Routine 2D-US was used in all transfemoral TAVR after January 1, 2014; before this, all cases were performed with angiographic guidance alone. ResultsThe primary outcome of interest was the composite of any access-related red blood cell transfusion or vascular/bleeding complications. Definitions were based on the Valve Academic Research Consortium (VARC-2) criteria. Fully adjusted multivariable regression models were developed to determine the impact of 2D-US. The study cohort included 387 patients, 109 (28%) of whom underwent femoral artery puncture guided by anatomic and angiographic landmarks, whereas 278 (72%) patients had 2D-US guidance. After adjusting for baseline differences in our multivariable models, we found that 2D-US–guided access was associated with an odds ratio of 0.42 (95% confidence interval, 0.25-0.70; P < 0.01) for the composite end point of access-related vascular or bleeding complications and red blood cell transfusion. ConclusionsThe routine use of 2D-US in transfemoral TAVR was associated with substantial reductions in access-related vascular and bleeding complications.

Foot dimensions and morphology in healthy weight, overweight and obese males

BackgroundOverweight and obesity are increasing in prevalence. However, despite reports of poor foot health, the influence of obesity and overweight on adult foot morphology has received limited attention. The objective of this work is to accurately and appropriately quantify the foot morphology of adults who are overweight and obese. MethodsThe foot morphology of 23 healthy weight (BMI=22.9kg.m−2), overweight (27.5kg.m−2) and obese (32.9kg.m−2) age (60years) matched males was quantified using a 3D scanner (all size UK 9). Data analysis computed normalised (to foot length) standard anatomical measures, and widths, heights and circumferences of 31 evenly spaced cross-sections of right feet. FindingsAnatomical measures of foot, ball and heel width, ball and heel circumference and ball height were all greater in the obese group than the healthy weight (P<0.05). Cross-sectional measures were significantly wider than the healthy group for the majority of measures from 14 to 67% (P=0.025–1.000) of heel-to-toe length. Also, the obese group had significantly higher midfoot regions (P=0.024–0.025). This increased foot height was not evident from anatomical measures, which were not sensitive enough to detect dimensional differences in this foot region. InterpretationFeet of obese adults differ from healthy and overweight individuals, notably they are wider. Data needs to avoid reliance upon discrete anatomical landmarks to describe foot morphology. In the obese, changes in foot shape do not coincide with traditional anatomical landmarks and more comprehensive foot shape data are required to inform footwear design.

Computed Tomography Analysis of Postsurgery Femoral Component Rotation Based on a Force Sensing Device Method versus Hypothetical Rotational Alignment Based on Anatomical Landmark Methods: A Pilot Study.

Rotation of the femoral component is an important aspect of knee arthroplasty, due to its effects on postsurgery knee kinematics and associated functional outcomes. It is still debated which method for establishing rotational alignment is preferable in orthopedic surgery. We compared force sensing based femoral component rotation with traditional anatomic landmark methods to investigate which method is more accurate in terms of alignment to the true transepicondylar axis. Thirty-one patients underwent computer-navigated total knee arthroplasty for osteoarthritis with femoral rotation established via a force sensor. During surgery, three alternative hypothetical femoral rotational alignments were assessed, based on transepicondylar axis, anterior-posterior axis, or the utilization of a posterior condyles referencing jig. Postoperative computed tomography scans were obtained to investigate rotation characteristics. Significant differences in rotation characteristics were found between rotation according to DKB and other methods (P < 0.05). Soft tissue balancing resulted in smaller deviation from anatomical epicondylar axis than any other method. 77% of operated knees were within a range of ±3° of rotation. Only between 48% and 52% of knees would have been rotated appropriately using the other methods. The current results indicate that force sensors may be valuable for establishing correct femoral rotation.

Traditional landmark versus ultrasound guided tracheal puncture during percutaneous dilatational tracheostomy in adult intensive care patients: a randomised controlled trial.

IntroductionLong-term ventilated intensive care patients frequently require tracheostomy. Although overall risks are low, serious immediate and late complications still arise. Real-time ultrasound guidance has been proposed to decrease complications and improve the accuracy of the tracheal puncture. We aimed to compare the procedural safety and efficacy of real-time ultrasound guidance with the traditional landmark approach during percutaneous dilatational tracheostomy (PDT).MethodsA total of 50 patients undergoing PDT for clinical indications were randomly assigned, after obtaining informed consent, to have the tracheal puncture procedure carried out using either traditional anatomical landmarks or real-time ultrasound guidance. Puncture position was recorded via bronchoscopy. Blinded assessors determined in a standardised fashion the deviation of the puncture off midline and whether appropriate longitudinal position between the first and fourth tracheal rings was achieved. Procedural safety and efficacy data, including complications and number of puncture attempts required, were collected.ResultsIn total, 47 data sets were evaluable. Real-time ultrasound guidance resulted in significantly more accurate tracheal puncture. Mean deviation from midline was 15 ± 3° versus 35 ± 5° (P = 0.001). The proportion of appropriate punctures, defined a priori as 0 ± 30° from midline, was significantly higher: 20 (87%) of 23 versus 12 (50%) of 24 (RR = 1.74; 95% CI = 1.13 to 2.67; P = 0.006). First-pass success rate was 20 (87%) of 23 in the ultrasound group and 14 (58%) of 24 in the landmark group (RR = 1.49; 95% CI = 1.03 to 2.17; P = 0.028). The observed decrease in procedural complications was not statistically significant: 5 (22%) of 23 in the ultrasound group versus 9 (37%) of 24 in the landmark group (RR = 0.58; 95% CI = 0.23 to 1.47; P = 0.24).ConclusionsUltrasound guidance significantly improved the rate of first-pass puncture and puncture accuracy. Fewer procedural complications were observed; however, this did not reach statistical significance. These results support wider general use of real-time ultrasound guidance as an additional tool to improve PDT.Trial registrationAustralian New Zealand Clinical Trials Registry ID: ACTRN12611000237987 (registered 4 March 2011)Electronic supplementary materialThe online version of this article (doi:10.1186/s13054-014-0514-0) contains supplementary material, which is available to authorized users.

Development and evaluation of an algorithm for the computer-assisted segmentation of the human hypothalamus on 7-Tesla magnetic resonance images.

Post mortem studies have shown volume changes of the hypothalamus in psychiatric patients. With 7T magnetic resonance imaging this effect can now be investigated in vivo in detail. To benefit from the sub-millimeter resolution requires an improved segmentation procedure. The traditional anatomical landmarks of the hypothalamus were refined using 7T T1-weighted magnetic resonance images. A detailed segmentation algorithm (unilateral hypothalamus) was developed for colour-coded, histogram-matched images, and evaluated in a sample of 10 subjects. Test-retest and inter-rater reliabilities were estimated in terms of intraclass-correlation coefficients (ICC) and Dice's coefficient (DC). The computer-assisted segmentation algorithm ensured test-retest reliabilities of ICC≥.97 (DC≥96.8) and inter-rater reliabilities of ICC≥.94 (DC = 95.2). There were no significant volume differences between the segmentation runs, raters, and hemispheres. The estimated volumes of the hypothalamus lie within the range of previous histological and neuroimaging results. We present a computer-assisted algorithm for the manual segmentation of the human hypothalamus using T1-weighted 7T magnetic resonance imaging. Providing very high test-retest and inter-rater reliabilities, it outperforms former procedures established at 1.5T and 3T magnetic resonance images and thus can serve as a gold standard for future automated procedures.

1724 Inexpensive Homemade Agar-Based Models for Ultrasound-Guided Central Venous Catheterization Training Programs

Background and AimsCentral venous catheterization (CVC) plays a central role in patient management in intensive care settings. Compared with the use of traditional anatomical landmarks, ultrasound (US)-guidance is associated with...

A Comparison of Lead Placement Through the Subclavian Vein Technique With Fluoroscopy-Guided Axillary Vein Technique for Permanent Pacemaker Insertion

BackgroundThe intrathoracic subclavian venous technique for pacemaker implantation may be associated with serious complications. We describe an alternative technique for obtaining venous access for pacemaker implantation through axillary vein under fluoroscopic guidance and compare it with the conventional, subclavian approach. MethodsWe conducted a single-centre, prospective, nonrandomized study. All adult patients with indication for permanent pacing who consented were recruited during a 3-year period. To access the axillary vein, we used the alternative technique with a new fluoroscopic landmark. The subclavian access was obtained as per the usual approach. ResultsWe studied 478 lead placements during 3 years; 315 lead placements through axillary venous technique (group 1) were compared with 163 lead placements through subclavian venous technique (group 2). Both routes had a high and comparable success rate, 98.09% in group 1 and 96.93% in group 2. The axillary approach was successful at the first attempt in 194 punctures (61.6%), as vs 60 in group 2 (36.8%) P < 0.0001. The average number of attempts in group 1 was 2.06 per patient and 2.56 in group 2 (P < 0.001). There were 3 (2.94%) pneumothoraxes in group 2 and none in group 1. During a mean follow-up period of 3.2 months in group1 and 3.7 months in group 2, 1 patient in group 2 had a lead fracture. ConclusionsThe fluoroscopically guided axillary venous approach for implanting permanent pacemakers is equivalent to the traditional anatomic landmark–guided intrathoracic subclavian approach and has fewer complications and shorter procedural time to access the vein.

Ultrasound-guided central venous catheterization in prone position

Central venous catheterization (CVC) is a commonly performed intraoperative procedure. Traditionally, CVC placement is performed blindly using anatomic landmarks as a guide to vessel position. Real-time ultrasound provides the operator the benefit of visualizing the target vein and the surrounding anatomic structures prior to and during the catheter insertion, thereby minimizing complications and increasing speed of placement. A 22-year-old male underwent open reduction and internal fixation of acetabulum fracture in prone position. Excessive continuous bleeding intraoperatively warranted placement of CVC in right internal jugular vein (IJV), which was not possible in prone position without the help of ultrasound. Best view of right IJV was obtained and CVC was placed using real-time ultrasound without complications. Ultrasound-guided CVC placement can be done in atypical patient positions where traditional anatomic landmark technique has no role. Use of ultrasound not only increases the speed of placement but also reduces complications known with the traditional blind technique.

Fluoroscopy vs. Traditional guided femoral arterial access and the use of closure devices: A randomized controlled trial

To compare the effectiveness of accessing the common femoral artery (CFA) using fluoroscopic guidance (FG) versus traditional anatomic landmark guidance (TALG) during cardiac catheterization and to determine the effect of the two modalities on the appropriateness for use of vascular closure devices (VCDs). Previous studies have shown a consistent relationship between the head of the femur and the CFA, yet there is no prospective data validating the superiority of fluoroscopy-assisted CFA access. A total of 972 patients were randomized to either FG or TALG access. The primary endpoint of the study was the angiographic suitability of the puncture site for VCD use. Secondary endpoints included arteriotomy location, time and number of attempts needed to obtain access, and the incidence of vascular complications. Of these, 474 patients were randomized into the FG arm and 498 patients into the TALG arm. A total of 79.5% of patients in the fluoroscopy arm and 80.7% in the traditional arm (P = 0.7) were deemed angiographically suitable for VCD based on the arteriotomy. The fluoroscopy group had significantly less arteriotomies below the inferior border of the head of the femur (P = 0.03). Total time for sheath insertion (105.7 +/- 130.7 vs. 106.5 +/- 152.6 sec) and number of arterial punctures (1.1 +/- 0.4 vs. 1.1 +/- 0.5) did not differ among the FG and TALG, respectively. The rates of vascular complications were not different. The angiographic suitability for VCD was not different between FG and TALG groups. Fluoroscopy decreased the number of low arteriotomies. The time to sheath insertion, number of arterial punctures needed to obtain access, and the incidence of complications were also similar.

Ultrasound-guided catheterization of the internal jugular vein in oncologic patients; Comparison with the classical anatomic landmark technique: A prospective study

Aim To compare the traditional anatomic landmark technique with the ultrasound-guided method for central venous catheterization. Material and methods During three years, 551 patients underwent internal jugular vein catheterization; in 347 patients, the ultrasound-guided technique was used, while in the other 204 patients the catheter was introduced by using the classical anatomic landmark method. Operating time, complications (pneumothorax, puncture of carotid artery with or without hematoma formation), and number of attempts to achieve central venous catheterization were recorded. Results The ultrasound-guided technique was associated with significantly shorter operating time (9.83 ± 3.1 vs. 20 ± 4.4 min, p < 0.001) and less morbidity (pneumothorax, 0 vs. 2 patients [ p < 0.05], carotid artery puncture with or without hematoma formation, 1 vs. 16 patients [ p < 0.05]). Moreover, the ultrasound-guided technique was highly successful in achieving central venous catheterization (failure, 0 vs. 18 patients [ p < 0.05]), with significantly fewer attempts (1–3 attempts in 204 vs. 283 [ p < 0.01]), compared to the classical anatomic landmark technique. Conclusion The ultrasound-guided method is faster, more efficient, and less morbid procedure compared with the classical anatomic landmark technique. Therefore, it should be preferred over the classical landmark method, especially in high-risk patients for the development of complications.

Introducing ultrasound-guided vein catheterization into clinical practice: A step-by-step guide for organizing a hands-on training program with inexpensive handmade models

Introduction Central vein catheterization (CVC) plays a central role in hospital patient management. Compared with the use of traditional anatomical landmarks, ultrasound-guidance is associated with higher CVC success rates, fewer complications, and more rapid central venous access. The use of US-guided CVC in clinical practice has not become widespread, largely because anesthesiology and general surgery residents receive limited training in this technique. To increase the use of US-guided CVC in our surgical department, we organized a hands-on training program based on the use of handmade models. Methods Three different models were constructed using plastic food-storage containers, segments of rubber tourniquet and silastic tubing (to simulate vessels), and agar gelatin. Results The hands-on training course allowed progressive acquisition of the basic hand–eye coordination skills necessary for performing US-guided venipuncture. The overall cost for each model was less than €5.00. Discussion The models described in this report are useful tools for teaching US-guided CVC. Thanks to their low-cost, they can be widely used to facilitate the introduction of this technique in clinical practice.

(222) Treatment of Genitofemoral Neuralgia After Laparoscopic Inguinal Herniorrhaphy with Fluoroscopically-Guided Tack Injection

Nerve entrapment syndromes involving the genital branch of the genitofemoral nerve, the ilioinguinal nerve, or the iliohypogastric nerve occur in an estimated 1–2% of conventional, open herniorrhaphies [3], and can also occur with laparoscopic herniorrhaphies [1]. A 48-year-old man with a recurrent right-sided inguinal hernia underwent a laparoscopic hernia repair using Prolene mesh and titanium tacks. Two weeks post-operatively, the patient spontaneously developed severe, intermittent, lancinating pain in a genitofemoral nerve distribution. Infection and recurrent hernia were ruled out. Treatment with non-steroidal anti-inflammatory drugs, muscle relaxants and ilioinguinal nerve blocks using traditional anatomic landmarks were unsuccessful. A focal point of tenderness at the inferolateral portion of the pubic ramus was investigated under fluoroscopy and was found to be directly overlying a surgical tack. Palpation over this site produced a Tinel's sign reproducing the patient's pain. A diagnostic injection using local anesthetic was performed at this site. The patient was pain-free for two months following the injection. When the pain returned, the injection was repeated using local anesthetic with corticosteroid, using the same fluoroscopically-guided technique. The patient has been asymptomatic since that time. Laparoscopic hernia repair may pose increased risk of nerve injury than conventional hernia repair [1]. With a conventional repair the nerves at risk are generally visible and may be dissected free, thus avoiding nerve injury. In contrast, with the laparoscopic repair the staples are placed preperitoneally and the nerves cannot be visualized. In a patient with suspected nerve entrapment syndrome following laparoscopic hernia repair, injection therapy may be effective treatment. As illustrated in this paper, fluoroscopy can be useful during physical exam and as an aid in localizing and for performing the injection. If an injection offers significant but transient relief, surgical removal of the staple or neurectomy at a site proximal to the lesion may be indicated [2].