Heads Of Sternocleidomastoid Muscle Research Articles

Morphometric Analysis of the Sternocleidomastoid Muscle and Associated Anatomical Landmarks: Implications for Surgical Procedures and Clinical Practice

Abstract Background: Sternocleidomastoid (SCM) a chief rotator and flexor of the neck divides the side of the neck into anterior and posterior triangles and acts as an important landmark for clinicians. It protects the vital structures of the neck such as the cervical plexus and vessels. The depression between the two heads of SCM, the lesser supraclavicular fossa is used by clinicians as a landmark for various procedures. Methodology: The study included 15 males and 6 females cadavers, in the Anatomy Department, at Kasturba Medical College, Manipal. The parameters measured were SCM length along the anterior and posterior border, mastoid tip to the exit of greater auricular nerve and spinal accessory nerve along the posterior border of SCM, and origin of superior thyroid artery to SCM origin along the posterior border. Results: SCM length along the anterior border was 19.91 cm and 16.48 cm in males and females, respectively. Along the posterior border was 16.04 cm and 13.88 cm. Greater auricular nerve point of exit to the mastoid tip is 7.29 cm and 5.93 cm in males and females respectively. All results were more in males compared to females. Conclusion: This detailed morphometric analysis of the sternocleidomastoid (SCM) muscle offers important insights into its anatomical relationships and variations, which are crucial for clinical practice. The gender-specific measurements of SCM length, nerve exit points, and vascular landmarks provide surgeons with precise anatomical guidance for procedures in the neck area.

Anatomical relationship between the omohyoid muscle and the internal jugular vein on ultrasound guidance

BackgroundInternal jugular vein catheterization is widely used in clinical practice, and there are many related studies on internal jugular vein catheterization. However, the omohyoid muscle, which is adjacent to the internal jugular vein, is a rarely mentioned muscle of the infrahyoid muscles group. The purpose of this study is to explore the anatomical relationship between the omohyoid muscle and the internal jugular vein on ultrasound guidance and provide a theoretical reference for jugular puncture and catheterization.MethodsThe study included 30 volunteers. The volunteer’s head lay in the neutral position and was then turned to the left at an angle of 30°, 45° and 60° with the bed surface, as verified using an adjustable protractor. A high-frequency ultrasound probe (6–14 Hz) was used to examine the plane of the apex of sternocleidomastoid triangle (PAST), the triangle consists of anatomical landmarks: a base was clavicle, its sides – heads of sternocleidomastoid muscle. And the plane of the middle of sternocleidomastoid triangle(PMST) which was a horizontal line, connecting midpoints of both sides. The right omohyoid muscle (OM) and the right internal jugular vein (IJV) were observed and recorded for statistical analysis.ResultsThere were statistically significant differences in the number of overlapping cases of OM and IJV at each head rotation angle between the PAST and PMST groups. There were statistically significant differences between the angles which OM and IJV centre point line and the left horizontal position of the PAST and PMST at different body angles.ConclusionThe traditional middle route puncture point is the apex of the sternocleidomastoid triangle, which can effectively avoid injury to the omohyoid muscle, to an extent.Trail registrationChiCTR2000034233, Registered 29/06/2020. www. Chinese Clinical Trial Registry.gov.

Ultrasonographic assessment of internal jugular vein diameter and its relationship with the carotid artery at the apex, middle, and base of the triangle formed by two heads of sternocleidomastoid muscle: A pilot study in healthy volunteers.

Background:Anteroposterior (AP) diameter of internal jugular vein (IJV) and its relative position with carotid artery (CA) varies in the triangle formed by two heads of sternocleidomastoid muscle, which is the site of insertion of needle for IJV cannulation. This study assessed the maximum AP diameter of the IJV in supine and Trendelenburg positions and during Valsalva maneuver (supine position) at the apex, middle, and base of the triangle and to study the relationship of the IJV with the CA.Materials and Methods:Twenty-five healthy volunteers were included and ultrasonography of IJV was performed in supine and Trendelenburg positions and during Valsalva maneuver (supine position) at the apex, middle, and base of the triangle bilaterally. The AP diameter of IJV was measured. The relative anatomical position of IJV was assessed as anterior (A), anterolateral (AL), or lateral (L) to CA in neutral head position and 30°, 45°, and 90° head rotation to the contralateral side in supine position.Results:The difference in right IJV diameter was significant (P = 0.001) between supine vs. Trendelenburg position at the base of the triangle. Within one position there was significant difference between apex and base of the triangle. The left IJV diameter was significantly different between supine vs. Trendelenburg position at the apex (P = 0.004), middle (P = 0.003), and base of the triangle (P-value = 0.001). There was significant difference between supine vs. Valsalva maneuver at the middle (P = 0.011) and base (P = 0.014) of the triangle. The right IJV was more L or AL to the CA in apex with head in neutral or 30° rotation. The left IJV was more L or AL to the CA in middle with head in neutral position.Conclusion:Trendelenburg and Valsalva increase diameter of IJV on both right and left side. Diameter of IJV is greater at the base of the triangle. IJV is lateral or anterolateral when the head is either neutral or turned 30° to the contralateral side.

Variation of Bilateral Multiheaded Sternocleidomastoid Muscle

The sternocleidomastoid muscle is important anatomically and clinically because of its relationship with many neurovascular structures in the neck. The muscle descends obliquely across the side of the neck and divides it into anterior and posterior triangles. In this case report, the additional clavicular head of bilateral sternocleidomastoid muscle was shown. During routine dissections of the neck for anatomy education in the Department of Anatomy Laboratory in the Faculty of Medicine at the Gazi University, additional clavicular heads of sternocleidomastoid muscle were observed bilaterally. The additional clavicular heads originated from the superior surface of the middle third of the clavicle. Furthermore, on the left side of the neck, muscle fibers originating from sternal head of sternocleidomastoid muscle and blending with clavicular head of sternocleidomastoid muscle were seen. Both of the minor supraclavicular triangles were narrower than normal. Unusual clinical cases in medical area makes diagnosis and treatment more difficult. Knowledge of anatomical variations is very important for avoiding of this difficulty.

Unilateral variation in the origin of third head of sternocleidomastoid muscle

Unilateral variation in the origin of third head of sternocleidomastoid muscle

Accessory head of sternocleidomastoid-a case report

AbstractAs many important nerves emerge from the posterior border of sternocleidomastoid (SCM), it is important to know the morphological anatomy of sternocleidomastoid for surgical as well as radiological purpose. During routine dissection of head and neck for student demonstration, an accessory head of sternocleidomastoid was found arising from the superior surface of the middle third of the clavicle on the right side of the neck. Sternocleidomastoid is a key landmark as it divides the neck into anterior and lateral regions (anterior and posterior triangles respectively. Morphological variations arise due to the complexity of sequential development of any region. SCM is an important surgical landmark for clinicians. A well versed knowledge of its variations can avoid diagnostic and surgical complications.

Modified Approach for Robotic Retroauricular Thyroidectomy: Preclinical Simulation and a Surgical Case.

Recently, a single remote access retroauricular robotic technique has been described for thyroid lobectomy. We aimed to explore the feasibility and safety of modifying this novel approach using preclinical cadaver model followed by performing the same operation in a real patient. The modified retroauricular approach was performed by creating a working space between the 2 heads of the sternocleidomastoid muscle, instead of that anterior to muscle. This was performed to create a wider working space. Two operations were initially performed in human cadavers. Subsequently, robotic-assisted thyroid lobectomy was performed using this novel modified retroauricular approach. Robotic-assisted hemithyroidectomy was performed successfully in 2 cadavers and subsequently in one patient using modified approach. The patient was discharged on the same day of surgery and had no complications. The modified retroauricular approach with creation of a working space between the 2 heads of sternocleidomastoid muscle is safe and feasible, and offers a wider working space for robotic thyroid surgery.

Third head of sternocleidomastoid muscle

AbstractDuring routine dissection in the neck region, a third head of sternocleidomastoid (SCM) muscle was found unilaterally in one cadaver and bilaterally in another cadaver. In both the cases third head was supplied by the spinal accessory nerve. SCM is most prominent muscle in the neck region which is used as important landmark during teaching living anatomy and gross anatomy of triangles of neck to students. As many important nerves and vessels are related to this key muscle of neck, any variation in relation to its origin, insertion and nerve supply attracts the attention of surgeons and anatomists. Embryological basis and clinical significance was discussed in these two cases of unilateral and bilateral presence of third head of SCM.

Third head of sternocleidomastoid muscle

During routine dissection in the neck region, a third head of sternocleidomastoid (SCM) muscle was found unilaterally in one cadaver and bilaterally in another cadaver. In both the cases third head was supplied by the spinal accessory nerve. SCM is most prominent muscle in the neck region which is used as important landmark during teaching living anatomy and gross anatomy of triangles of neck to students. As many important nerves and vessels are related to this key muscle of neck, any variation in relation to its origin, insertion and nerve supply attracts the attention of surgeons and anatomists. Embryological basis and clinical significance was discussed in these two cases of unilateral and bilateral presence of third head of SCM.

Anatomical variations of the internal jugular vein in relation to carotid artery : an ultrasound study

Background: In developing country like India, central venous catheter is still inserted using anatomical landmark guidance with success rate up to 97.6% and complications up to 15%. Aims & Objective: This study was aimed to determine the anatomical variations of the internal jugular vein (IJV) in relation with carotid artery (CA) with the help of 2-D ultrasound. Material and Methods: This prospective randomized study was conducted in a teaching and tertiary care hospital on 100 young healthy volunteers of either sex, aged 20 years to 40 years. Each volunteer was placed supine with 15˚ down trendlenberg position with 45˚ neck rotation on contra-lateral side. Linear array probe with 7.5 M Hz of “Sonosite Micromaxx” ultrasound machine was placed perpendicular to the apex of the triangle formed by two heads of sternocleidomastoid muscle and clavicle. Vessels were visualized in transverse section in 2-D ultrasound. Exact location of IJV was identified in relation to the CA on ultrasound and recorded as lateral, antero-lateral, anterior, medial, and posterior. The diameter of IJV and CA, distance from skin to IJV were recorded on both sides of neck for each volunteer. Anterior position of IJV in relation to CA was defined as dangerous position. Small sized IJV was defined as diameter ≤7 mm. Data were analyzed using Graphpad prism software version 5.1. P value < 0.05 was taken as significant. Results: The mean diameter of IJV was 13.23 (2.52) mm in right and 10.25(2.29) mm in left side of neck (p=0.0001). Small sized IJV was in 1% in right and 8% in left side (p=0.0349). 15% and 28% of volunteers had dangerous position of IJV in relation to CA on right and left side of neck respectively (p=0.0381). Conclusion: Significant number of healthy young volunteers had anatomical variations in terms of size and position of IJV (left side > right side) in relation of CA by ultrasound screening. Thus, anatomical landmarks are not sufficient, alternative measures like ultrasound scanning should be implemented prior to catheterization to identify the individual with potentially difficult catheterization.

Neutral versus 45 degree rotated position of head for internal jugular vein cannulation: A comparative study based on ultrasonography

Background: Most of the methods do not specify its optimal degree of head rotation during central venous catheterization. Aims & Objective: To compare neutral versus 45 degree rotated position of head for internal jugular vein (IJV) cannulation based on ultrasonography. Material and Methods: This prospective, randomized study was conducted in a teaching and tertiary care hospital. Randomly selected 100 healthy volunteers were placed supine with 15o trendelenberg position. Head of the volunteer was kept neutral in group N (100 volunteers) and 45o rotated in group R (100 volunteers). 7.5 M Hz linear array probe of a portable ultrasound was placed perpendicular to the apex of triangle formed by two heads of sternocleidomastoid muscle and clavicle. We simulated a line as a needle insertion on ultrasound screen passing the mid-point of the IJV. A “hit” was defined as the intersection of the inner lumen of carotid artery (CA) by simulated line. The observations were recorded for both sides of neck for each group. Student’s t test was applied for quantitative data and Fisher exact test for qualitative data. P value 0.05). The distance of IJV from skin was more in group N than R (right side: 10.29±1.88 versus 9.75±1.88, p=0.0436; left side: 10.75±1.87 versus 10.21±1.86, p=0.0416). Conclusion: A neutral position was safer than 45 o neck rotation during IJV cannulation with regard to CA puncture.

A Rare Case of Unilateral Third Head of Sternocleidomastoid Muscle

Un caso raro de una tercera cabeza unilateral del musculo esternocleido-mastoideo se observo durante disecciones de rutina para los estudiantes de medicina de pregrado. La tercera cabeza adicional se origino en el tercio medio de la clavicula y se unio a las dos cabezas normales (esternal y clavicular) del musculo en el medio del cuello. La insercion y e inervacion del musculo fue normal. Este caso puede ser importante para los cirujanos de cabeza y cuello y para cirujanos plasticos que realizan cirugias de injerto muscular

Efficacy and safety of echoguided catheterisation approach in oncological and hematological patients. Report on 843 consecutive patients

19581 Background: A central venous catheter (CVC) represents the most frequently adopted intravenous line for patients undergoing infusional chemotherapy, bone marrow transplantation (BMT) and parenteral nutrition. The aim of this study was to explore the feasibility and safety of CVC insertion under ultrasound (US) control. US offers the advantage of real-time, multiplanar imaging as well as Doppler analysis. Methods: The echoguided approach allowed us to insert CVC in right supraclavicular site nearby the clavicular head of sternocleidomastoid muscle. Using a 7.5-MHz probe we were able to perform a real time control of the hip of the needle while it was inserted in the last side of internal jugular vein. At the end of the procedure chest Rx was executed to evaluate CVC position and to detect pneumotorax. Mainly Sekalon Seldy, Becketon Dickinson was employed. For PBSC collection, 14-gauge Arrow double lumen revealed to be highly efficacious (46 PBSC collections, no one failure). Results: From November 1999 to December 2006 the echoguided CVC insertion method was applied 1003 times in 843 patients. The procedure was applied 288 times in haematological malignancies, in 698 solid tumors, in 3 neurological autoimmune diseases. Among solid tumors colon carcinoma was the first indication, while gastric carcinoma the second. Among haematological patients: non-Hodgkin lymphoma was the first indication, then acute leukemia. Ten patients underwent allogenic BMT and 92 autologous BMT. Nine in 1003 procedures failed (1%). Failures were caused by: arterial puncture in 3, CVC dislocation in 1, vein collapse in 3 and no efficacious “eco window” in 2. No pneumotorax was registered. The safety of this procedure was confirmed by 35 catheterisations obtained with platelets under 20000/μl, by 7 procedure with prothrombin activity under 50%. In 44 patients catheter was inserted with neutrophil count below 100/μl and in 66 below 500/μl without any increase in infections. Mean time of catheter permanence was 151 days with 1,7 infectious events every 1000 days of permanence. Symptomatic deep veins thrombotic complications were 9 (1%). Conclusions: This procedure is safe, cheap with high accuracy and success rate, and above all US-guidance avoids pneumothorax. No significant financial relationships to disclose.

Transaxillary endoscopic release of restricting bands in congenital muscular torticollis – a novel technique

Congenital muscular torticollis is due to fibrosis of one or both the heads of sternocleidomastoid muscle. This may also involve the platysma, scalene muscles, and the carotid sheath and may be associated with cervical scoliosis. Conventional surgical procedures leave visible scars. Ramirez, who used the posterior part of the traditional face-lift incision, made perhaps the first attempt at concealing scars. Burstein et al. reported a large series of subcutaneous endoscopic release of torticollis through a hairline approach. Sasaki described an endoscopic two-incision, posterior auricular fold and hairline approach. A technique of transaxillary subcutaneous endoscopy for the release of the sternocleidomastoid muscle in congenital muscular torticollis is described here. This procedure provides direct access to the fibrous bands, enables release without risk of damage to the spinal accessory nerve, external jugular vein, or greater auricular nerve, and leaves no visible neck scars. Two cases of congenital muscular torticollis presenting in adulthood were managed successfully by this technique. The fibrotic part of sternocleidomastoid muscle was released and the normal range of head motion was restored. There were no surgical complications encountered and the patients achieved complete pain free range of movement in six weeks. This technique provides direct and quick access, perpendicular to the line of the fibrotic bands, avoids injury to neurovascular structures and does not leave visible neck scars.

An anomalous muscle crossing the supraclavicular triangle: the cleidotrachelian muscle

An abnormal muscle is described that passes superficially across omohyoid in the left posterior triangle of the neck. Its origin resembles that of scalenus anterior, but its form is triangular and it inserts directly onto the superior surface of the clavicle just lateral to the clavicular head of sternocleidomastoid. Its anatomical course gives it morphological and embryological interest; its relations in the supraclavicular triangle give it considerable surgical relevance. The name cleidotrachelian muscle is suggested.