Sternocleidohyoid muscle: an unreported variant of cleidohyoid muscle.

Sternohyoid, sternothyroid, omohyoid, and thyrohyoid muscles are collectively known as infrahyoid muscles. These muscles frequently show variations in their attachments. Here, an extremely rare variant muscle belonging to this group has been presented. During cadaveric dissection for undergraduate medical students, an additional muscle was found between sternohyoid and superior belly of omohyoid muscles bilaterally in a male cadaver aged approximately 70 years. This muscle took its origin from posterior surface of the manubrium sterni, capsule of the sternoclavicular joint and the posterior surface of the medial part of the clavicle. It was inserted to the hyoid bone between the attachments of sternohyoid and superior belly of omohyoid muscles and was supplied by a branch of ansa cervicalis profunda. There is no report on such a muscle in the literature and it could be named as "sternocleidohyoid muscle". Knowledge of this muscle could be useful in neck surgeries.

Surgical and embryological perspective of a big loop of internal carotid artery extending laterally beyond internal jugular vein.

Knowledge of variations of the internal carotid artery is significant to surgeons and radiologists. The internal carotid artery normally runs a straight course in the neck. Its anomalies can lead to its iatrogenic injuries. We report a case of a large loop of the internal carotid artery in a male cadaver aged about 75 years. The common carotid artery terminated by dividing it into the external carotid artery and internal carotid arteries at the level of the upper border of the thyroid cartilage. From the level of origin, the internal carotid artery coursed upwards, backwards and laterally, and formed a large loop behind the internal jugular vein. The variation was found on the left side of the neck and was unilateral. The uncommon looping of the internal carotid artery might result in altered blood flow to the brain and may lead to misperceptions in surgical, imaging, and invasive procedures.

Partial duplication of tentorium cerebelli and complete duplication of falx cerebelli.

Variations of the dural folds and the dural venous sinuses are infrequently reported in the existing medical literature. Such variations in the posterior cranial fossa may pose difficulties in various analytical and surgical procedures of this region. We present a rare concurrent variation of the falx cerebelli and tentorium cerebelli that was detected during routine dissection of an adult male cadaver. While removing the brain, a partial duplication of tentorium cerebelli was observed below the left half of the tentorium cerebelli and above the left cerebellar hemisphere. This fold did not have any dural venous sinus in it. Further, a complete duplication of falx cerebelli with a single occipital venous sinus within its attached border was also observed. We present the review of literature and discuss the comparative anatomy of this case.

Double-bellied superior rectus muscle.

Congenital variations of extraocular muscles are rare. We report a double-bellied superior rectus muscle, observed in an adult male cadaver aged 70 years. The superior rectus muscle had two equal-sized bellies, which took separate origins from the common tendinous ring and united to form a common belly 1 cm before the insertion. Due to the duplication, the muscle extended laterally beyond the levator palpebrae superioris. Both its bellies were supplied by oculomotor nerve. To the best of our knowledge, this is the first report on doubling of the belly of the superior rectus muscle.

Solitary osteochondroma in the body of the pubic bone: a cadaveric case report.

Osteochondromas develop as cartilaginous nodules in the periosteum of bones. They are the commonest benign tumors of the skeleton, generally observed in the long bones. Rarely, they are also found in the axial skeleton, flat bones of skull and facial bones. During a regular dissection, we came across a solitary osteochondroma in posterior surface of the body of the right pubic bone. Histopathology of the bony projection confirmed the typical features of the osteochondroma. The symptomatic osteochondromas are usually evaluated during radiographic examination. Though, the observed osteochondroma is relatively smaller its unusual location is remarkable and knowledge of occurrence of such nodules is clinically important during the diagnosis and planning of treatment.

Surgical and radiological importance of a rare cysto-duodeno-colic peritoneal fold.

It is quite common to see abnormal peritoneal folds in the abdominal cavity. Some of them might compress or strangulate the viscera and others might determine the direction of the flow of peritoneal fluid, pus or blood. Many unusual clinically important peritoneal folds such as Ladd's band, cysto-gastro-colic fold, omento-cystic fold, and cysto-colic fold have been reported earlier. Knowledge of these folds is important for radiologists, gastroenterologists, and surgeons. We report an unusual cysto-duodeno-colic fold observed during our dissection classes. The fold was seen to compress the duodenum and colon. The fold extended from the descending part of the duodenum and the transverse colon to the gallbladder. It enclosed the entire gallbladder. A case similar to this has not been reported yet. It is important for the gastroenterologists and laparoscopic surgeons to be aware of this fold to avoid misdiagnosis and iatrogenic injuries.

Variant Superficial Branch of Radial Artery along with Supplementary Tendons on the Dorsum of the Hand and Their Surgical Implications.

Variations of radial artery, in both its course and branching pattern in the anatomical snuffbox, are clinically significant for the plastic surgeons, cardiologists, and radiologists. Reports on its abnormal high origin and subsequent superficial course have been well documented. Herein, we report an unusual superficial branch of the radial artery given off before its entry into the palm by passing between the two heads of first dorsal interosseous. It eventually divided into princeps pollicis and radialis indicis arteries at the first web space of palm as a unique vascular variation. Apart from this, in the present case, the tendon of extensor digiti minimi and of extensor indicis divided into two parts. The split tendons of extensor digiti minimi were inserted to the dorsal digital expansion of the digitus minimus. However, lateral tendon of split extensor indicis was inserted along with the tendon of extensor digitorum to the index finger and the medial one was inserted along with the tendon of extensor digitorum to the middle finger. Unusual superficial branch of radial artery on the dorsum of the hand is vulnerable for an iatrogenic injury during surgical approaches in the region. Supplementary extensor tendons on the hand are one of the potential causes for the tenosynovitis.

High incidence of persistence of sacral and coccygeal intervertebral discs in South Indians - a cadaveric study.

The sacrum, by virtue of its anatomic location plays a key role in providing stability and strength to the pelvis. Presence of intervertebral discs in sacrum and coccyx is rare. Knowledge of its variations is of utmost importance to surgeons and radiologists. The current study focused on the presence of intervertebral discs between the sacral and coccygeal vertebrae in south Indian cadaveric pelvises. We observed 56 adult pelvises of which, 34 (61%) pelvises showed the presence of intervertebral discs between the sacral vertebrae and between the coccygeal vertebrae, while 22 (39%) pelvises did not have the intervertebral discs either in the sacrum or the coccyx. We also found that most of the specimens had discs between S1 and S2 vertebrae (39%), followed by, between S4 and S5 (18%), between S2-S3 (14%) and least being between S3-S4 (13%). In the coccyx it was found that 7% of pelvises had disc between Co1-Co2, 4% of them had between Co2-Co3 and 4% had between Co3-Co4. Knowledge regarding such anatomic variations in the sacro-coccygeal region is important to note because they require alterations in various instrumentation procedures involving the sacrum.

Le sacrum, en raison de son emplacement anatomique, joue un rôle essentiel pour assurer la stabilité et la force du bassin. La présence de disques intervertébraux dans le sacrum et le coccyx est rare. La connaissance de ses variations est d'une importance capitale pour les chirurgiens et les radiologues. L'étude actuelle a porté sur la présence de disques intervertébraux entre les vertèbres sacrées et coccygiennes sur des bassins cadavériques dans le sud de l'Inde. Nous avons observé 56 bassins adultes, dont 34 (61 %) ont montré la présence de disques intervertébraux entre les vertèbres sacrées et coccygiennes, tandis que 22 (39 %) autres n'avaient pas des disques intervertébraux, dans le sacrum ou le coccyx. Nous avons également constaté que la plupart des spécimens avaient un disque entre les vertèbres S1 et S2 (39 %), 18 % avaient un disque entre les vertèbres S4 et S5, et enfin 14 % entre S3 et S4. Dans le coccyx, on a constaté que 7 % des bassins avaient un disque entre Co1 et Co2, 4 % d'entre eux l'avaient entre Co2 et Co3 et 4 % entre Co3 et Co4. Il est important de noter la connaissance de ces variations anatomiques de la région sacro-coccygienne en raison des modifications nécessaires à apporter aux diverses procédures d'instrumentation impliquant le sacrum.

A South Indian cadaveric study on obturator neurovascular bundle with a special emphasis on high prevalence of 'venous corona mortis'.

Surgical procedures in the pelvic region are very challenging because of the complex anatomy of this region. "Corona mortis" is a term used to describe retro-pubic anastomosis between the obturator and external iliac vessels. It is considered as a key structure as significant haemorrhage may occur if the vessels are cut accidentally during pelvic surgeries. Earlier studies have documented a high frequency of venous anastomosis compared to its arterial counterpart. The objective of our study was to document the prevalence of venous corona mortis in South Indian human adult cadaveric pelvises. We conducted this study on 73 cadaveric pelvic halves. Out of the 73 hemi pelvises, 36 were normal without any variations of the obturator vessels while 37 hemi pelvises (51%) showed the presence of abnormal obturator vessels which proves to be a very high incidence in terms of variations. Out of the 37 hemi pelvises, 25 (68%) showed the presence of 2 obturator veins, out of which 1 was normal and the other was an abnormal obturator vein. 8 hemi pelvises (22%) had only abnormal obturator vein. Most of the abnormal obturator veins drained into the external iliac vein, while two veins drained into inferior epigastric veins. Venous corona mortis is said to be frequently encountered during surgery and is considered to be as important as arterial corona mortis in its clinical implications. Individual evaluation of this risky anatomical structure should be done prior to any surgical interventions.

Evaluation of Numerical and Positional Variations of the Hepatic Veins: A Cadaveric Study.

INTRODUCTION: Hepatic veins are the major linking vessels between systemic and portal circulation. Numerical and positional variation of the hepatic veins can play a significant role during surgical interventions on the liver. MATERIALS AND METHODS: Gross anatomical study regarding the number and arrangement pattern of hepatic veins was undertaken on 88 adult livers which were stored in 10% formalin after the regular dissection classes. RESULT: Six livers (7%) were found to be drained only by major hepatic veins, whereas 82 out of 88 livers (93%) had accessory (minor) hepatic veins. The total number of persistent hepatic veins ranged from 2 to 10 with the highest prevalence of four hepatic veins (35.2%) followed by 5 (19.3%) and 6 (17%). The presence of three major veins was seen in 45 (51%) livers while 41 (47%) livers had two major hepatic veins. Remaining two livers (2%) showed the presence of four major hepatic veins. In 95% specimens, the minor hepatic veins entered the inferior vena cava below the level of entry of major veins. In 2.5% cases, their entry point was above the major veins and in 2.5% cases, the entry point was below major veins. CONCLUSION: The data resulting from this study provides a clear idea about the number and drainage pattern of the hepatic veins into the liver. Knowledge of numerical and positional variations of hepatic veins could be useful in normal Doppler ultrasound hepatic vein flow velocities and their variation with respiration in healthy adults as comparable with the similar approach of superior vena cava.

Multiple variations in the pelvic vasculature - a case report.

A thorough knowledge of possible variations of pelvic vasculature is very useful for surgeons, gynaecologists, radiologists, urologists and orthopaedic surgeons. We report multiple vascular variations in the left half of the pelvis of an adult male cadaver. Iliolumbar artery arose from the main trunk of the internal iliac artery. Posterior division of the internal iliac artery gave two lateral sacral arteries and a superior gluteal artery. The anterior division of the internal iliac artery gave origin to superior vesical, inferior vesical, inferior gluteal and internal pudendal arteries. The internal pudendal artery gave origin to a common trunk before leaving the pelvis. The common trunk divided into middle rectal artery and deep artery of the penis. The obturator artery took origin from the inferior epigastric artery and descended downward to the pelvis and left the pelvis by passing through the obturator foramen. Most of the other veins accompanying the arteries joined to form a plexus on the superior surface of the pelvic diaphragm. This plexus condensed to form anterior and posterior divisions of the internal iliac vein. Apart from this, the posterior part of the plexus drained directly into the common iliac vein through a large unnamed vein.

A study on the number and arrangement of the structures passing through the porta hepatis in South Indian population / Estudio sobre el número y disposición de las estructuras que pasan por la fisura porta hepática en individuos del sur de la India

The porta hepatis of the liver is a very important area surgically. The knowledge of the variations in the structures passing through the porta hepatis might be of great help in reducing the risks of surgery in this area. In the current study 59 livers from South Indian cadavers were observed for the number and arrangement of the structures passing through the porta hepatis. In all the livers the portal vein was posteriormost and the hepatic duct was the anteriormost structure. The hepatic artery and its branches were in between the duct and the vein. The mean weight of the liver was 1.025 kg. The mean length of porta hepatis was 4.825 cm and the mean breadth was 2.433 cm. The number varied from one to three for the duct and vein but for the artery it was between one and four. In 51% of livers, only one vein and in 80% of cases only one duct passed through the porta hepatis. In 56% of cases two arteries passed through the porta hepatis.

La fisura porta hepática del hígado es un área quirúrgica muy importante. El conocimiento de las variaciones en las estructuras que pasan a través de la fisura porta hepática puede ser de gran ayuda para reducir los riesgos de la cirugía de esta región. En el presente estudio se observaron 59 hígados procedentes de cadáveres del Sur de la India, en relación al número y disposición de las estructuras que pasan a través de la fisura porta hepática. En todos los hígados, la vena porta hepática fue el elemento más posterior y el conducto hepático común el más anterior. La arteria hepática y sus ramas se ubicaban entre el conducto hepático común y la vena porta hepática. El peso medio de los hígados fue 1,025 kg. La longitud media de la fisura porta hepática fue 4,825 cm y el ancho medio de 2,433 cm. El número varió de uno a tres para el conducto y la vena. El número de arterias varió entre una y cuatro. En 51% de los hígados, sólo una vena pasaba a través de la fisura porta hepática y en el 80% de los casos sólo pasaba un conducto. En el 56% de los casos, dos arterias pasaban a través de la fisura porta hepática.

Dangerous course and atypical termination of the splenic vein in relation to pancreas--a case report.

CONTEXT: Knowledge of variations of the vessels closely related to the pancreas adds greatly to the success of pancreatic surgery. Splenic vein is one of the vessels that are closely related to the pancreas. Its variations might not only change the haemodynamics in the vein but also cause unexpected bleeding during pancreatic surgery. CASE REPORT: During our dissection classes, we noted the variations in the course and termination of the splenic vein. After emerging from the spleen, it coursed upward and to the right, embedded in a groove on the anterior surface of body of pancreas. After reaching the upper border, it turned downwards and entered the body of the pancreas. After having a downward course in the body of pancreas, it emerged out and united with the superior mesenteric vein at an angle of about 160 degrees to form the portal vein. CONCLUSION: This peculiar course of the vein might predispose it for thrombosis in case of pancreatitis. It can also lead to iatrogenic injuries during pancreatic or splenic surgeries.

A lobulated spleen with multiple fissures and hila.

During our dissection classes, we observed a lobulated spleen with multiple hila and fissures. The spleen presented 4 hila and 5 deep fissures. The hila were seen on the visceral surface. The fissures extended into the substance of the spleen from superior border, inferior border and the visceral surface. Because of these fissures, the spleen appeared to be lobulated, having seven distinct lobes/lobules. Knowledge of this variation could be useful to the radiologists and surgeons.

Eight prehilar branches of the right renal artery.

Imaging technology with its advancement in the field of urology is the boon for the patients who require minimally invasive approaches for various kidney disorders. These approaches require a precise knowledge of the normal and variant anatomy of vessels at the hilum of the kidney. During routine dissections, a variation in the branching pattern of the right renal artery was noted in an adult male cadaver. The right renal artery divided into upper and lower divisions 6cm away from the hilum of the kidney. The upper division gave 4 branches, and the lower division gave two branches. These two branches further bifurcated and gave 2 branches each. Thus, there were 8 prehilar branches of renal artery. The multiple prehilar branches led to a congested atmosphere at the hilum of the kidney. This arterial congestion might result in hindering the blood flow at the renal hilum. Apart from this, it might cause difficulties in diagnostic and therapeutic invasive procedures. Knowledge of this variation is of importance to radiologists and urologists in particular.

Presence of multiple tendinous insertions of palmaris longus: a unique variation of a retrogressive muscle.

BACKGROUND: Palmaris longus, being the most variable muscle of the upper extremity is generally considered important morphologically rather than functionally. The palmar aponeurosis represents the distal part of the tendon of Palmaris longus. CASE DETAILS: We report here a unique case of palmaris longus presenting variation distally as its tendon divides to gain multiple attachments with the fascia covering the abductor pollicis brevis, flexor retinaculum and the tendon of flexor carpi ulnaris. In addition, it also continues as palmar aponeurosis as its normal course. CONCLUSION: Presence of this kind of variation might result in compression of the median and ulnar nerves and may aggravate the complications in case of inflammation of palmar aponeurosis thus mimicking the manifestations of Dupuytren's contracture.

A rare variation in the origin and course of the artery of penis.

Vascular variations of the penis are very rare. Awareness of its variations is of utmost importance to the urologists and radiologist dealing with the reconstruction or transplants of penis, erectile dysfunctions, and priapism. We report an extremely rare variation of the artery of the penis and discuss its clinical importance. The artery of the penis arose from a common arterial trunk from the left internal iliac artery. The common trunk also gave origin to the obturator and inferior vesical arteries. The artery of the penis coursed forward in the pelvis above the pelvic diaphragm and divided into deep and dorsal arteries of the penis just below the pubic symphysis. The internal pudendal artery was small and supplied the anal canal and musculature of the perineum. It also gave an artery to the bulb of the penis.

Variant origin of an arterial trunk from axillary artery continuing as profunda brachii artery--a unique arterial variation in the axilla and its clinical implications.

BACKGROUND: Axillary artery is known to show different variations mostly in its branching pattern. Similarly, the origin of profunda brachii is often encountered with abnormality. Therefore, when the vascular variations in the upper limb persist, mostly it is confined to its branching pattern followed by its variant origin. But, among all the reported variations of profunda brachii, its variant origin from the 3rd part of the axillary artery with common trunk for the branches of axillary artery is unique. CASE DETAILS: We report here an anomalous origin of profunda brachii as continuation of an arterial trunk arising from 3rd part of the axillary artery. This common trunk at its commencement passed between 2 roots of median nerve and gave branches of 3rd part of axillary artery before it continued as profunda brachii artery. The further course and branching pattern of profunda brachii were normal. CONCLUSION: Since the axillary artery is next choice of artery for arterial cannulation in cardiopulmonary bypass procedures, prior knowledge of existence of such variation in its branching pattern helps in avoiding possible diagnostic or interventional therapeutic errors.