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.

Short Axillary Vein and an Axillary Venous Ladder Formed by Basilic and Brachial Veins – An Anatomical and Clinical Perspective

Knowledge of anatomic variants of veins in the arm and axilla play a key role in planning of successful venous access. Possible anatomic variants of axillary vein, brachial vein and basilic vein and their clinical implications have been well described in the literature. We report a rare case of formation of a short axillary vein associated with complex venous communications between the basilic and brachial veins forming a venous ladder in the axilla, in formalin embalmed male cadaver. Axillary vein was formed in the upper part of the axilla by the fusion of basilic vein and unpaired brachial vein, and it was about 3cm in length. The higher-up confluence of basilic and brachial veins was also associated with presence of three communicating veins between the basilic and brachial veins in the axilla. Knowledge of reported venous variations is very useful during preoperative venous mapping and also for planning and execution of various surgical invasive procedures involving these veins.

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.

Unusual Path of Branches of Ilioinguinal Nerve: A Clinically Important Anatomic Variant

Ilioinguinal nerve is a collateral branch of lumbar plexus. Its anatomical variations in relation to adjacent musculoaponeurotic structures play a crucial role in the development of neuropathies associated with lower abdominal surgeries. In this report, we present a rare case of unusual course and branches of the ilioinguinal nerve, in a 55-year-old male cadaver. In the lateral part of inguinal canal ilioinguinal nerve gave three branches. Two of its branches pierced the external oblique aponeurosis, about 6 cm above the pubic symphysis, to supply the skin of the lower part of the anterior abdominal wall. Another branch pierced the conjoint tendon, in the medial part of the inguinal canal about 2 cm above the superficial inguinal ring. Knowledge of unusual path of these branches may be important to avoid injuries during the surgical repair of groin hernias. Further care should be taken while dealing with the conjoint tendon in the Bassini procedure.

A Rare Unilateral Variation in the Course of External and Internal Carotid Arteries

Vascular variations in the neck region are not uncommon. Knowledge of incidence of morphological variations in the course and branching of the carotid arteries is important for radiological interpretation and surgical correction when they are symptomatic. Internal carotid artery (ICA) is known to show elongation in its extra cranial course. Previous studies have demonstrated the incidence and clinical symptoms of this morphological entity. However, the occurrence of elongation and looping of the external carotid artery (ECA) is seldom reported in the literature. During regular dissections, we came across a rare case of unilateral morphological variation of both ECA and ICA, in a male cadaver aged about 55 years. ICA presented a curved course with convexity directed posteriorly, at the level of the C2-C3 vertebrae. ECA presented a pronounced kinking or coiling, one inch below the level of the angle of the mandible. In addition, a linguo-facial trunk arising from the ECA also presented a pronounced kinking throughout its entire length.

Variant Origin of the Left Vertebral Artery from a Vertebro-Subclavian Trunk Associated with an Unusual Branch Arising from the Brachiocephalic Trunk

Variant origin of the left vertebral artery (LVA) from the arch of aorta is well documented in the literature. Involvement of complex sequential developmental steps in the aortic arch formation results in different patterns of origin of LVA. Morphological variations in the LVA are thought to alter the cerebral hemodynamics and can cause the cerebral dysfunction. Knowledge of the morphological variations of the LVA is useful while performing the head and neck and thoracic surgeries. We here report one of the extremely rare patterns of the LVA origin, in a male cadaver aged about 65 years. LVA and left subclavian artery (LSA) arose as a common vertebro-subclavian trunk from the convexity of the aortic arch. Further, brachiocephalic trunk (BT) gave an unusual artery from its anterior surface. This artery divided into thymic and tracheal branches. Variant origin of thymic branch may be crucial during imaging and thymectomy procedures.

Triple falx cerebelli associated with two aberrant venous sinuses in the floor of posterior cranial fossa.

During regular dissection classes, we came across tripled falx cerebelli in a male cadaver. The main (middle) falx cerebelli was large and was attached to the internal occipital crest. It contained the occipital sinus. There were two smaller folds (right and left), one on either side of the falx cerebelli. There were two aberrant venous sinuses; each one connecting the ipsilateral sigmoid and transverse sinuses with each other. The complex dural-venous variation reported here is seldom reported in the literature. Knowledge of such variation is important for neurosurgeons and neuroradiologists as these aberrant folds could cause haemorrhage during suboccipital approaches or may lead to erroneous interpretation during imaging of the posterior cranial fossa.

Multiple variations in the paired arteries of the abdominal aorta.

Variations in the origin of arteries in the abdomen are very common. The arteries that show frequent variations include the celiac trunk, renal arteries, and gonadal arteries. We observed multiple variations in a 45-year-old male cadaver. The variations found on the left side were: one accessory renal artery, two testicular arteries, and middle suprarenal and inferior phrenic arteries that branched from the celiac trunk. On the right side, the inferior phrenic and middle suprarenal arteries arose from the right renal artery.

Absence of inferior pancreaticoduodenal artery compensated by dorsal pancreatic artery: a case report.

Consideration of new aspects of vascular anatomy of the pancreaticoduodenal region is required for further improvement of surgical procedures. Awareness of variations in arteries supplying the duodenum and pancreas can help in minimizing the blood loss during surgery. We report the absence of inferior pancreaticoduodenal artery, which was compensated by a large dorsal pancreatic artery arising from proximal part of the splenic artery. This artery replaced inferior pancreaticoduodenal artery and formed a large loop of anastomosis with the gastroduodenal artery.

Bilateral prehilar multiple branching of renal arteries: a case report and literature review.

Proper knowledge of variations of the arteries supplying the kidney is essential not only to the anatomists but also to the surgeons. In the present paper we are reporting a case of bilateral early and multiple branching of the renal arteries. The origin of the 2 renal arteries was normal but soon after their origin they ended by giving rise to multiple branches. Most of these branches entered the kidney through the hilum. However, on both sides, one of the branches (superior polar artery) passed superolaterally to reach the upper pole of the kidney. The superior polar artery also gave rise to the inferior suprarenal artery. Further, related literature review is done and the urological implications of these variations in renal surgeries are discussed.

Clinically important variations in the lower limb - A case report

In this paper, three variations in the lower limbare reported and their clinical importance is discussed.The variations reported include a duplicationof the piriformis muscle, the tibial nervebeing pierced by the tendon of the plantaris andan additional muscle in the peroneal compartmentof the leg (AU)