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Results for “Anatomic Landmarks”

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PubMed1998

Accuracy of registration methods in frameless stereotaxis.

The accuracy of image to patient registration is a critical issue in the intraoperative use of frameless stereotaxic instruments for surgical guidance. This study was performed to assess the accuracy of image to head phantom registration using several standard registration techniques and a clinical frameless stereotaxic instrument. Two types of radioopaque fiducial markers were fixed to a plastic head phantom, and a computed tomography scan of the phantom was performed in the routine fashion. Image to phantom registration was carried out using fiducial markers, fiducial markers plus surface fit, anatomic landmarks, and anatomic landmarks plus surface fit. After each registration, linear inaccuracy measurements were performed for each of 32 markers. Each registration was performed 10 times, and the overall mean error measurements and anterior and posterior error were computed and compared. The overall mean error was smallest for the fiducial registration alone (2.07 mm). The magnitude of error increased significantly for posterior locations for all other registration techniques, but it was not significantly increased for the fiducial registration method. For this hardware configuration, registration with surface-applied fiducial markers is measurably more accurate than registration with surface anatomic landmarks. The addition of surface points to the fiducial registration does not increase the registration accuracy but, in fact, increases the degree of error.

Computer Systems↗

PubMed2004

Optimal head rotation for internal jugular vein cannulation when relying on external landmarks.

External anatomic landmarks have traditionally been used to approximate the location of the neck blood vessels to optimize central venous cannulation of the internal jugular vein (IJV) while avoiding the common carotid artery (CCA). Head rotation affects vessel orientation, but most landmark techniques do not specify its optimal degree. We simulated catheter insertion via both an anterior and central approach to the right IJV using an ultrasound probe held in the manner of a syringe and needle in 49 volunteers. Increased head rotation from 0 degrees, 15 degrees, 30 degrees, 45 degrees, and 60 degrees to the left of midline was associated with higher probability of a simulated needle contacting the IJV and the CCA. For both approaches, the risk of CCA contact was <10% for head rotations of <or=45 degrees. Increased body surface area (BSA) and body mass index (BMI) were associated with more CCA contact at head rotations of 45 degrees or 60 degrees. To optimize IJV contact while reducing the likelihood of inadvertent contact with the CCA, the head should be rotated no more than 30 degrees in patients with high BMI or BSA, but it may be turned to 60 degrees if BMI or BSA is low.

Adult↗

PubMed2003

Medial approach for tibial bone graft: anatomic study and clinical technique.

PURPOSE: The purpose of this study is to quantify the amount of bone graft material present in the proximal tibia via a lateral versus a medial approach, as well as describe an alternative technique for obtaining this bone graft material. A quantitative anatomic and statistical analysis and comparison are presented. The goal of this study is to demonstrate the advantages and simplicity associated with utilizing the proximal tibia as a bone graft harvest site in oral and maxillofacial surgery via a medial approach. MATERIAL AND METHODS: Forty lower extremities from 20 cadavers were studied. All specimens were dissected, and anatomic landmarks were recorded. Anatomic structures, including vessels, nerves, muscle attachments, articular surfaces, and their relationships to various anatomic landmarks were identified, measured with a linear millimeter ruler, and recorded. Bone harvest was accomplished using either a medial (20 extremities) or lateral (20 extremities) approach. The amount of bone available for harvest using both techniques was compared. Variables evaluated included volume of graft, age, gender, and relationships among anatomic structures. RESULTS: The mean volume of bone harvested was 25.0 mL for the lateral approach and 24.9 mL for the medial approach (range, 14 to 34 mL). The Mann-Whitney U test revealed no significant difference in mean volume of graft obtained when comparing the medial and lateral approaches (P =.9250). Pearson's correlation test revealed no correlation between age (P =.089 medial and P =.174 lateral) or gender (P =.3120 medial and P =.4440 lateral). The lateral anatomic structures evaluated included the anterior tibial vessels that emerged from the interosseous hiatus 14.3 mm inferior to tibial perpendicular and 42.6 mm lateral to the tibial parallel line. The distance from the tibial perpendicular to the articular surface did not significantly differ when comparing the medial (33.65 mm) and lateral (33.25 mm) anterior tibial surfaces. The mean length of the oblique line was 17.9 mm, and the superior portion of this line was 14.65 mm above the tibial perpendicular line. CONCLUSIONS: Equal amounts of bone graft material are available for harvest from the medial and lateral aspects of the proximal tibia. Knowledge of important anatomic landmarks can be used preoperatively to allow for safe dissection and harvest of autogenous bone from the proximal tibia. The dissection of medial proximal tibia and harvest of bone graft material may be accomplished efficiently with minimal chances of damage or morbidity to vital adjacent structures.

Adult↗

PubMedDate not supplied

Reproducibility of anatomic tibial landmarks for anterior cruciate ligament reconstructions.

We evaluated the reproducibility of landmarks used for accurate anatomic placement of the tibial tunnel in anterior cruciate ligament reconstruction. Landmarks evaluated were the medial tibial eminence, the posterior cruciate ligament, the "over-the-back" position, the true posterior border of the tibia, and the posterior border of the lateral meniscus. Forty-two pairs of cadaveric knees were dissected, and anatomic measurements were made regarding the anterior cruciate ligament insertion and these various landmarks. Statistical analysis was used to confirm reproducibility and significance. Measurements based on the medial tibial eminence and posterior border of the meniscus were particularly erratic. The most reproducible anatomic landmark was the posterior cruciate ligament. The anterior border of the posterior cruciate ligament was consistently 6.7 mm posterior to the posterior border of the anterior cruciate ligament and 10.9 mm posterior to the central sagittal insertion point of the anterior cruciate ligament. The over-the-back position was consistently in contact with the anterior border of the posterior cruciate ligament if the knee was flexed with a posterior-directed force applied. In this position, the over-the-back position was equally reproducible as compared with the posterior cruciate ligament. Measurements gauged from the true posterior border of the tibia gave a second rigid bony landmark but with a wider standard deviation than the posterior cruciate ligament-based landmarks. The relative anterior-posterior dimension of the tibia did not correlate with the relationship between the anterior cruciate ligament and other anatomic landmarks.

Anterior Cruciate Ligament↗

PubMed2003

Femoral anatomical frame: assessment of various definitions.

The reliability of the estimate of joint kinematic variables and the relevant functional interpretation are affected by the uncertainty with which bony anatomical landmarks and underlying bony segment anatomical frames are determined. When a stereo-photogrammetric system is used for in vivo studies, minimising and compensating for this uncertainty is crucial. This paper deals with the propagation of the errors associated with the location of both internal and palpable femoral anatomical landmarks to the estimation of the orientation of the femoral anatomical frame and to the knee joint angles during movement. Given eight anatomical landmarks, and the precision with which they can be identified experimentally, 12 different rules were defined for the construction of the anatomical frame and submitted to comparative assessment. Results showed that using more than three landmarks allows for more repeatable anatomical frame orientation and knee joint kinematics estimation. Novel rules are proposed that use optimization algorithms. On the average, the femoral frame orientation dispersion had a standard deviation of 2, 2.5 and 1.5 degrees for the frontal, transverse, and sagittal plane, respectively. However, a proper choice of the relevant construction rule allowed for a reduction of these inaccuracies in selected planes to 1 degrees rms. The dispersion of the knee adduction-abduction and internal-external rotation angles could also be limited to 1 degrees rms irrespective of the flexion angle value.

Algorithms↗

PubMedDate not supplied

Measurement of fundal height.

Fundal height should not be assessed by comparing the uterus with anatomic landmarks on the maternal abdomen because of the following reasons: 1) the inability to assess fundal growth accurately when the uterus is measured in finger breadths or as a fraction of the distance between two landmarks; 2) biologic variability in the placement of anatomic landmarks on the maternal abdomen; 3) disagreement among clinicians and researchers on the precise relationship between the fundus and anatomic landmarks at each stage of gestation; and 4) variability among women in the number of gestational weeks at which the uterine fundus reaches the umbilicus. A rational basis for continuing the practice of comparing fundal height with anatomic landmarks on the maternal abdomen does not exist. Inexpensive and more accurate techniques of measuring fundal growth are readily available.

Female↗

PubMed2006

Localization of anatomical point landmarks in 3D medical images by fitting 3D parametric intensity models.

We introduce a new approach for the localization of 3D anatomical point landmarks. This approach is based on 3D parametric intensity models which are directly fitted to 3D images. To efficiently model tip-like, saddle-like, and sphere-like anatomical structures we introduce analytic intensity models based on the Gaussian error function in conjunction with 3D rigid transformations as well as deformations. To select a suitable size of the region-of-interest (ROI) where model fitting is performed, we also propose a new scheme for automatic selection of an optimal 3D ROI size based on the dominant gradient direction. In addition, to achieve a higher level of automation we present an algorithm for automatic initialization of the model parameters. Our approach has been successfully applied to accurately localize anatomical landmarks in 3D synthetic data as well as 3D MR and 3D CT image data. We have also compared the experimental results with the results of a previously proposed 3D differential approach. It turns out that the new approach significantly improves the localization accuracy.

Algorithms↗

PubMed2003

Localization of anatomical point landmarks in 3D medical images by fitting 3D parametric intensity models.

We introduce a new approach for the localization of 3D anatomical point landmarks based on 3D parametric intensity models which are directly fit to the image. We propose an analytic intensity model based on the Gaussian error function in conjunction with 3D rigid transformations as well as deformations to efficiently model tip-like structures of ellipsoidal shape. The approach has been successfully applied to accurately localize anatomical landmarks in 3D MR and 3D CT image data. We have also compared the experimental results with the results of a previously proposed 3D differential operator. It turns out that the new approach significantly improves the localization accuracy.

Algorithms↗

PubMed2005

A randomized-controlled study of ultrasound prelocation vs anatomical landmark-guided cannulation of the internal jugular vein in infants and children.

BACKGROUND: A specifically designed ultrasound scanner may be helpful in percutaneous cannulation of the internal jugular vein in pediatric patients. We report a new two-dimensional (2D) ultrasound prelocation (UL) technique using a transesophageal echocardiography (TEE) intraoperative probe instead of the portable scanner, and have compared the new technique with conventional anatomical landmark method (AL) for central venous catheterization in infants and children. METHODS: Sixty-two infants (body weight <12 kg) undergoing elective surgery for congenital heart disease were randomized into two groups. In the AL group, the landmark for cannulation was the palpation of the common carotid pulsation or the sternocleidomastoid triangle. In the UL group, the central vein was located by 2D ultrasonic imaging using a TEE intraoperative probe for HP SONOS 4500. The number of cannulation attempts, success rate, and complication rate were recorded. RESULTS: For the UL and AL groups, the cannulation success rate was 100% and 80% (P < 0.05), the incidence of arterial puncture was 3.1% and 26.7% (P < 0.025), and the number of attempts was 1.57 +/- 1.04 and 2.55 +/- 1.76 (P < 0.001), respectively. CONCLUSIONS: Two-dimensional ultrasound prelocated central venous catheterization in infants and children is convenient and can markedly increase cannulation success rate and reduce the incidence of complications.

Catheterization, Peripheral↗

PubMed1999

An anatomically based protocol for the description of foot segment kinematics during gait.

OBJECTIVE: To design a technique for the in vivo description of ankle and other foot joint rotations to be applied in routine functional evaluation using non-invasive stereophotogrammetry. DESIGN: Position and orientation of tibia/fibula, calcaneus, mid-foot, 1st metatarsal and hallux segments were tracked during the stance phase of walking in nine asymptomatic subjects. Rigid clusters of reflective markers were used for foot segment pose estimation. Anatomical landmark calibration was applied for the reconstruction of anatomical landmarks. BACKGROUND: Previous studies have analysed only a limited number of joints or have proposed invasive techniques. METHODS: Anatomical landmark trajectories were reconstructed in the laboratory frame using data from the anatomical calibration procedure. Anatomical co-ordinate frames were defined using the obtained landmark trajectories. Joint co-ordinate systems were used to calculate corresponding joint rotations in all three anatomical planes. RESULTS: The patterns of the joint rotations were highly repeatable within subjects. Consistent patterns between subjects were also exhibited at most of the joints. CONCLUSION: The method proposed enables a detailed description of ankle and other foot joint rotations on an anatomical base. Joint rotations can therefore be expressed in the well-established terminology necessary for their clinical interpretation. RELEVANCE: Functional evaluation of patients affected by foot diseases has recently called for more detailed and non-invasive protocols for the description of foot joint rotations during gait. The proposed method can help clinicians to distinguish between normal and pathological pattern of foot joint rotations, and to quantitatively assess the restoration of normal function after treatment.

Adult↗

PubMedDate not supplied

Functional anatomy of pointing and grasping in humans.

The functional anatomy of reaching and grasping simple objects was determined in nine healthy subjects with positron emission tomography imaging of regional cerebral blood flow (rCBF). In a prehension (grasping) task, subjects reached and grasped illuminated cylindrical objects with their right hand. In a pointing task, subjects reached and pointed over the same targets. In a control condition subjects looked at the targets. Both movement tasks increased activity in a distributed set of cortical and subcortical sites: contralateral motor, premotor, ventral supplementary motor area (SMA), cingulate, superior parietal, and dorsal occipital cortex. Cortical areas including cuneate and dorsal occipital cortex were more extensively activated than ventral occipital or temporal pathways. The left parietal operculum (putative SII) was recruited during grasping but not pointing. Blood flow changes were individually localized with respect to local cortical anatomy using sulcal landmarks. Consistent anatomic landmarks from MRI scans could be identified to locate sensorimotor, ventral SMA, and SII blood flow increases. The time required to complete individual movements and the amount of movement made during imaging correlated positively with the magnitude of rCBF increases during grasping in the contralateral inferior sensorimotor, cingulate, and ipsilateral inferior temporal cortex, and bilateral anterior cerebellum. This functional-anatomic study defines a cortical system for "pragmatic' manipulation of simple neutral objects.

Adult↗

PubMed2001

Anatomic levels: important landmarks in penectomy specimens: a detailed anatomic and histologic study based on examination of 44 cases.

The majority of squamous cell carcinomas of the penis arise from the glans, and the prognosis is related significantly to the depth of invasion of crucial anatomic landmarks. Accurate information related to this can only be obtained when specimens are carefully evaluated grossly. Most pathologists in developed countries encounter resected specimens of penile carcinoma infrequently, and gross evaluation is occasionally suboptimal, potentially preventing obtaining reliable prognostic information. The four distinct levels of the glans penis are the epithelium, lamina propria, corpus spongiosum, and corpus cavernosum. A simple method for pathologic evaluation of the glans is presented. Noteworthy findings in our study of a South American population were that the distance from the lamina propria to tunica albuginea ranged from 7 to 13 to 6 mm at the dorsal, central, and ventral areas of the corpus spongiosum, respectively. The most distal portion of the corpus cavernosum was located within the glans in 34 of 44 cases and in the body of the penis in only 10. The corpus spongiosum was thinner in the former cases. These anatomic variations may bear on prognosis.

Adenocarcinoma↗

PubMed2000

[First experiences with a noninvasive patient set-up system for radiotherapy of the prostate].

PURPOSE: Highly conformal radiotherapy techniques require precise patient positioning. We report our first experience with a new cast system for fixation of the pelvis during stereotactically guided intensity modulated radiotherapy (IMRT) of the prostate with respect to positioning accuracy of the prostate. MATERIAL AND METHODS: The immobilization device consists of a custom-made wrap-around body cast that extends from the abdomen to the thighs and a separate head mask, both made from Scotchcast, and attaches to a frame for extracranial stereotaxy. Sixteen CT-studies (> or = 25 slices, thickness: 3 mm) of 2 patients who were immobilized for IMRT of prostate tumors were evaluated with respect to set-up accuracy of bony structures and the prostate itself. CT-studies were performed immediately before or after a treatment fraction. Deviations of bony landmarks and anatomical landmarks inside the planning target volume were measured in all 3 dimensions. RESULTS: Mean patient movements of 0.15 +/- 0.3 mm (latero-lateral), 0.9 +/- 1 mm (anterior-posterior), 1 +/- 1 mm (tranversal vectorial error) and < 3 mm slice thickness (craniocaudal) were recorded using bony landmarks and 0.9 +/- 0.9 mm (latero-lateral), 1.8 +/- 1.5 mm (anterior-posterior), 2.2 +/- 1.5 mm (transversal vectorial error) and < 3 mm (craniocaudal) using the confines of, or landmarks within the prostate. Standard deviations of absolute positioning error as an often used metric for positioning accuracy ranged between 0.3 and 1.7 mm in the transversal plane. The worst case transversal vectorial deviation for the prostate was 4.4 mm. Figure 4 summarizes the set-up accuracy of bony landmarks and the prostate. CONCLUSION: The presented combination of a body cast and head mask system in a rigid stereotactic body frame ensures reliable noninvasive patient fixation for fractionated extracranial stereotactic radiotherapy. It provides precise and reliable positioning of the prostate and meets the requirements for highly conformal radiotherapy such as IMRT. No further improvement of repositioning can be achieved with external immobilization devices since the positioning error of the target relative to the skeleton exceeds the accuracy of the positioning of the skeleton itself.

Humans↗

PubMed1999

Anatomic correlates of acoustic rhinometry as measured by rigid nasal endoscopy.

Acoustic rhinometry (AR) evaluates the cross-sectional areas and volume of the nasal cavity through acoustic reflections. Successive valleys displayed on an AR graph are believed to correspond to anatomic landmarks. To assess the anatomic accuracy of AR, we performed AR and endoscopic measurements with a rigid endoscope in 85 normal human subjects after topical decongestion. Endoscopic measurements were recorded for distances between the midcolumella and the nasal valve, the anterior end of the inferior turbinate, the anterior end of the middle turbinate, the midportion of the middle turbinate, and the posterior nasopharynx. The first AR valley most closely corresponded with endoscopic measurements of the nasal valve. The second valley had a mean value that corresponded with the anterior end of the inferior turbinate. The third valley matched best with the values of the anterior end of the middle turbinate. Nasopharyngeal measurements by each modality yielded a good agreement. AR appears to correspond to nasal anatomic landmarks but not in an exact point-to-point manner.

Adult↗

PubMed1996

Does Laparoscopic Gastric Banding Demand Sophisticated Measurement Devices?

BACKGROUND: One of the most frequently discussed issues used and a free space for the tip of the Endo-Babcock in gastric banding is the Problem of intraoperative upper gastric Pouch volume assessment and the calibration of the connecting stoma diameter. Having experience with more than 200 adjustable and non-adjustable laparoscopic gastric bandings in last 3 years, we started to study whether it is possible to assess the Pouch volume and stoma diameter by relying on anatomical landmarks and simple bougie calibration, rather than on sophisticated measuring devices. METHODS: We compared results of Postoperative pouch volume control measurements in a group of patients in whom a balloon method of Pouch volume measurement was performed during the gastric banding with a group of patients where no intraoperative measurements of the upper gastric pouch were done. In the latter group the Pouch volume was assessed according to the anatomical landmarks during the dissection: the cardia at the lesser curvature and the avascular area of gastrophrenic ligament at the greater curvature. In both groups endoscopic study 2 weeks following surgery was performed. Concerning stoma diameter we started with a prospective randomized study of two groups. In the first group, we intraoperatively measured by manometry the inside-stoma pressure. In the second group, a simple bougie calibration was used, and a space was left for the tip of the Endo-Babcock instrument between the stomach wall and the band. Postoperatively, the stoma diameters were compared, using the 'balloon catheter pulled through the stoma' method. RESULTS: Pouch volume: in the group operated according to surgeon's assessment of the anatomical landmarks, 96% of the patients' pouch volume did not exceed 60 ml at 2 weeks postoperative checkups The results were no different from the group of patients where intraoperative volume measurements were performed. The stoma diameter: a group of patients where intraoperative stoma pressure measurements were performed and a second group where a simple calibration bougie was instrument was left between stomach wall and band were compared prospectively. There was no statistical difference between the two groups in stoma diameter measured 2 weeks after operation by the 'balloon pull through' method. CONCLUSIONS: It is possible to rely on anatomical landmarks in constructing the upper gastric pouch. Postoperatively, five volume measurements did not show any statistical difference between the group in whom intraoperative Pouch volume measurements were performed and the group where anatomical landmarks were used. There was no statistical difference in postoperative stoma diameter measurements between the group where intraoperative stoma pressure measurements were performed before Closing the band and the group where just a calibration bougie was used and a free space for the tip of an endoscopic instrument was left between stomach wall and band. These measurements were made with the non-adjustable band. With the adjustable band, the stoma diameter measurements would be even less important.

Journal Article↗

PubMed1987

Precision of preoperative electrophysiological study in predicting the intraoperatively defined location of single left-sided accessory pathways.

In 34 patients with a left-side anomalous pathway (AP) considered for arrhythmia surgery, the atrial insertion of the anomalous pathway in the preoperative investigation was determined by using three different techniques. The atrial activation sequence during orthodromic tachycardia or ventricular stimulation was recorded in the coronary sinus by using either (a) unipolar leads from an eight-polar electrode catheter with an interelectrode distance of 1 cm, (b) bipolar leads from consecutively positioned pairs of electrodes on the same electrode catheter or (c) bipolar leads recorded at one centimeter intervals by withdrawal of the electrode catheter. The corresponding location at surgery was obtained by atrial epicardial mapping during ventricular stimulation. Each way of recording the atrial activation sequence in the coronary sinus during orthodromic tachycardia or ventricular stimulation was compared with regard to their predictive value in assessing the corresponding location by intraoperative mapping. At surgery, a visual grid system was used to define the anatomical landmarks which were located 20 mm apart. When the unipolar technique was used to assess the anomalous pathway location, there was a difference corresponding to a distance of 2-2.5 anatomical landmarks (48 mm) between the preoperative and intra-operative assessments. With the bipolar technique the difference was up to 3 anatomical landmarks (60 mm) while it was up to 4.5 anatomical landmarks (90 mm) when the withdrawal technique was employed. The unipolar technique was superior in differentiating a left lateral from a left posterior or a septal location.

Adolescent↗

PubMed2001

The TALON removable head frame system for stereotactic radiosurgery/radiotherapy: measurement of the repositioning accuracy.

PURPOSE: To present the TALON removable head frame system as an immobilization device for single-fraction intensity-modulated stereotactic radiosurgery (IMRS) and fractionated stereotactic intensity-modulated radiotherapy (FS-IMRT); and to evaluate the repositioning accuracy by measurement of anatomic landmark coordinates in repeated computed tomography (CT) examinations. METHODS AND MATERIALS: Nine patients treated by fractionated stereotactic intensity-modulated radiotherapy underwent repeated CTs during their treatment courses. We evaluated anatomic landmark coordinates in a total of 26 repeat CT data sets and respective x, y, and z shifts relative to their positions in the nine treatment-planning reference CTs. An iterative optimization algorithm was employed using a root mean square scoring function to determine the best-fit orientation of subsequent sets of anatomic landmark measurements relative to the original image set. This allowed for the calculation of the x, y, and z components of translation of the target isocenter for each repeat CT. In addition to absolute target isocenter translation, the magnitude (sum vector) of isocenter motion and the patient/target rotation about the three principal axes were calculated. RESULTS: Anatomic landmark analysis over a treatment course of 6 weeks revealed a mean target isocenter translation of 0.95 +/- 0.55, 0.58 +/- 0.46, and 0.51 +/- 0.38 mm in x, y, and z directions, respectively. The mean magnitude of isocenter translation was 1.38 +/- 0.48 mm. The 95% confidence interval ([CI], mean translation plus two standard deviations) for repeated isocenter setup accuracy over the 6-week period was 2.34 mm. Average rotations about the x, y, and z axes were 0.41 +/- 0.36, 0.29 +/- 0.25, and 0.18 +/- 0.15 degrees, respectively. Analysis of the accuracy of the first repeated setup control, representative of single-fraction stereotactic radiosurgery situations, resulted in a mean target isocenter translation in the x, y, and z directions of 0.52 +/- 0.38, 0.56 +/- 0.30, and 0.46 +/- 0.25 mm, respectively. The mean magnitude of isocenter translation was 0.99 +/- 0.28 mm. The 95% confidence interval for these radiosurgery situations was 1.55 mm. Average rotations at first repeated setup control about the x, y, and z axes were 0.24 +/- 0.19, 0.19 +/- 0.17, and 0.19 +/- 0.12 degrees, respectively. CONCLUSION: The TALON relocatable head frame was seen to be well suited for immobilization and repositioning of single-fraction stereotactic radiosurgery treatments. Because of its unique removable design, the system was also seen to provide excellent repeat immobilization and alignment for fractionated stereotactic applications. The exceptional accuracy for the single-fraction stereotactic radiosurgical application of the system was seen to deteriorate only slightly over a 6-week fractionated stereotactic treatment course.

Algorithms↗

PubMed1997

A sonographically guided technique for central venous access.

OBJECTIVE: The internal jugular vein (IJV) is an important access to the central venous system. We compared sonographically guided technique with the traditional anatomic landmark technique for IJV catheterization. SUBJECTS AND METHODS: In a prospective randomized trial, 100 patients underwent routine catheterization of the IJV (50 patients in the sonography group and 50 patients in the anatomic landmark group). Access time, failure rates, and complication rates were evaluated. In addition, the physicians' number of years of experience with catheter insertion was recorded. RESULTS: Access time was markedly shorter with the sonographically guided technique (mean, 15.2 sec; range, 8-76 sec) than with the anatomic landmark technique (mean, 51.4 sec; range, 3-820 sec) (p = .001). The failure rate was significantly lower with the sonographically guided technique (p = .002). Complications were fewer with the sonographically guided technique (neck hematoma, 2% versus 10%; plexus irritation, 4% versus 6%; carotid artery puncture, 0% versus 12%). We found that the number of years of postgraduate clinical training was greater in the group of physicians using the anatomic landmark technique. CONCLUSION: The sonographically guided technique is associated with less risk and less inconvenience for patients, especially critically ill patients, for whom the technique provides fast, safe, and easy IJV catheterization.

Catheterization, Central Venous↗