Anatomical variations of the human suprarenal arteries

This is on anatomical study of the suprarenal arteries and their variations in 30 cadavers aimed at providing in a subsequent article the anatomical basis of arterial segments of the gland. The suprarenal glands were supplied by 3 main groups of suprarenal arteries: superior, middle and inferior. Only the superior and the inferior groups were present in all cases, since the middle vessels appeared in only 93.3% +/- 4.6 of the cases. The superior group included on each side 4 arteries in males and 5 in females; the middle group presented only 1 artery on each side in both males and females, and the inferior group exhibited on each side 2 arteries in males and 1 artery in females. The most variable group was the middle one, the aortic origin being the most frequent but with a relatively low incidence (53.3% +/- 9.1 on the right and 46.7% +/- 9.1 on the left). The superior group originated from the posterior branch of the ipsilateral inferior phrenic artery in 83.3% +/- 6.8 on the right and 80% +/- 7.3 on the left. The arteries of the inferior group were branches of the ipsilateral renal artery in 70% +/- 8.4 on the right and 50% +/- 9.1 on the left. The origin of the middle suprarenal arteries from the trunk of the inferior phrenic artery on both sides (26.7% +/- 8.1 on the right and 36.7% +/- 8.8 on the left) should be considered relevant. The anatomical findings warrant a further investigation for the identification, illustration and nomenclature of arterial anatomicosurgical segments.     

Anatomical variations in the formation of the human oesophageal hiatus

The formation of the oesophageal hiatus was studied in 50 human diaphragms in which crura and the median arcuata ligaments were carefully dissected and their fibres were carefully traced to the central tendon. In 98% of the cases the right crus was divided into a medial, a middle and a lateral bundle. In 90% the left crus was divided into a medial and a lateral bundle. The medial bundle of the right crus was a constant component in bounding the hiatus. The undivided crura did not contribute to the borders of the hiatus. 5 variations in the formation of the hiatus were observed. In 62% the hiatus was bounded by the 2 crura mainly the right; the left crus shared only in the formation of the posterior border. In 10% the 2 crura contributed equally to the formation of the hiatus; the hiatus was formed by the medial bands. In 10% the hiatus was formed exclusively by the right crus. In 2% the hiatus was formed exclusively by the left crus. In 16% crura had no direct relation to the hiatus except posteriorly and the hiatus was bounded by a V-shaped band from the median arcuate ligament, this finding has not been previously reported. The functional significance of these variations was discussed.     

Anatomical variations in the human paranasal sinus region studied by CT

A precise knowledge of the anatomy of the paranasal sinuses is essential for the clinician. Conventional radiology does not permit a detailed study of the nasal cavity and paranasal sinuses, and has now largely been replaced by computerised tomographic (CT) imaging. This gives an applied anatomical view of the region and the anatomical variants that are very often found. The detection of these variants to prevent potential hazards is essential for the use of current of endoscopic surgery on the sinuses. In the present work, we have studied the anatomical variants observed in the nasal fossae and paranasal sinuses in 110 Spanish subjects, using CT in the coronal plane, complemented by horizontal views. We have concentrated on the variants of the nasal septum, middle nasal concha, ethmoid unciform process and ethmoid bulla, together with others of lesser frequency. The population studied showed great anatomical variability, and a high percentage (67%) presented one or more anatomical variants. Discounting agger nasi air cells and asymmetry of both cavities of the sphenoidal sinus, which were present in all our cases, the variations most often observed were, in order, deviation of the nasal septum, the presence of a concha bullosa, bony spurs of the nasal septum and Onodi air cells.     

Anatomical variations in the coronary arteries

The following are observations on 500 consecutive cases of coronary angiographical studies carried out on patients without any case history of myocardial ishcemia. There were 251 males and 249 females. The patients' average age was 45 years old.     

Anatomical variations of lumbosacral plexus

Basis

Deviations detected during spinal operations have motivated us to start research related to variations of lumbosacral plexus formation. Aim of this work was to find out deviations of its formation from ascension of particular roots from foramen invertebrale and foramina sacralia up to formation of terminal branches.

Set

One hundred lumbosacral plexi have been examined in 50 adult cadavers for a purpose to find out an incidence of neural variations. We have observed participation of Th₁₂ root, L₄ and L₅ roots in its formation, as well as various deviations from ascension of particular plexiform roots up to their ending branches. For lumbal plexus, we have observed four nerve roots and six lumbal nerves; for sacral one, three sacral roots with a share of S₄ and lumbosacral trunk formed of L₄ and L₅ roots and four sacral nerves. We have considered also their course, anastomoses and thickness. We highlight motoric innervation particularities in relation to diagnostics besides anatomical complexity and variability.

Results

Variations on the level of neural roots were common, nerve formations were uncommon. Thickness of neural roots, formation or their absence were dependent on the type of plexus, particularly in sacral area. For lumbal plexus, L₁ root was the thinnest and L₄ root was the thickest. L₃ root was the thickest in six cases. Fifth lumbal root usually completely filled foramen invertebrale. We have observed double ascension of L₄ root from foramen invertebrale in 25 cases and plexiform in five cases. In other cases it was branched in various distance following ascension from foramen invertebrale. Plexiform ascension of L₃ root along with L₄ root was present in two cases. Double ascension of L₃ root was present in four cases. L₂, L₃ along with L₅ roots were doubled in two cases. Iliohypogastric nerve was the longest, ilioinguinal was the thinnest and nervus femoralis was the thickest. Changes in sacral plexus on the level of neural roots have been observed 41-times. Double ascension of L₅ root was present in eight cases and plexiform in four cases. Double S₁ root at ascension from foramina sacralia was present 16 times, S₂ 8 times, S₃ once and S₁ along with S₂ 4 times. S₁, S₂ and S₃ roots were branched in various distance following ascension from foramina sacralia in 15 cases. Truncus lumbosacralis was thickened in 19 cases, a share from L₄ root was thicker as L₅ root in 11 cases. Low level of connection between truncus lumbosacralis and S₁ root was observed in 10 cases. Nervus ischiadicus has branched into tibial and peroneal portions already in minor pelvis in two cases. The level of distance of n. (nervus) gluteus superior, n. gluteus inferior, n. cutaneus femoris posterior and n. pudendus was dependent on the plexus type.

Conclusion

This study enabled us to find out and to describe extraordinary anatomical deviations in formation of neural roots and nerves of lumbal and sacral plexus, undescribed yet.     

Anatomical variations of the anterior talofibular ligament of the human ankle joint

Compared with other joints, the ligaments of the ankle have not been studied in great detail; consequently relatively little literature exists. The positions of the 3 major bands of the lateral collateral ligament are well known and documented (Schafer et al. 1915; Sarrafian, 1983; McMinn, 1994; Palastanga et al. 1994; Williams et al. 1995). The detailed anatomy of the ligaments is, however, relatively complex with variations of the major bands and several minor additional bands being reported (Sarrafian, 1993; Burks & Morgan, 1994; Rosenberg et al. 1995).     

The carotid bodies in bronchial asthma

A histological study was made of right-sided carotid bodies resected therapeutically from 50 patients with bronchial asthma. Also studied as controls were 10 right-sided carotid bodies from subjects coming to necropsy. Hypoxaemia was considered a contra-indication to glomectomy and only patients with a resting arterial oxygen tension exceeding 65 mm Hg were submitted to operation. It was found that in patients with a short history of bronchial asthma the carotid bodies were not enlarged, but there was hyperplasia of sustentacular cells. In cases with asthma for 5 years or more the sustentacular cell hyperplasia was more pronounced and was associated with many nerve fibrils and slight enlargement of the carotid bodies. The functional significance of the proliferation of sustentacular cells and the abundance of nerve axons is obscure. In the asthma cases there was prominence of the dark variant of chief cells, thought to be related to episodes of hypoxaemia.     

Anatomical variations of the sural nerve

An anatomical study of the formation of the sural nerve (SN) was carried out on 76 Thai cadavers. The results revealed that 67.1% of the SNs were formed by the union of the medial sural cutaneous nerve (MSCN) and the lateral sural cutaneous nerve (LSCN); the MSCN and LSCN are branches of the tibial and the common fibular (peroneal) nerves, respectively. The site of union was variable: 5.9% in the popliteal fossa, 1.9% in the middle third of the leg, 66.7% in the lower third of the leg, and 25.5% at or just below the ankle. One SN (0.7%) was formed by the union of the MSCN and a different branch of the common fibular nerve, running parallel and medial to but not connecting with the LSCN, which joined the MSCN in the lower third of the leg. The remaining 32.2% of the SNs were a direct continuation of the MSCN. The SNs ranged from 6-30 cm (mean = 14.41 cm) in length with a range in diameter of 3.5-3.8 mm (mean = 3.61 mm), and were easily located 1-1.5 cm posterior to the posterior border of the lateral malleolus. The LSCNs were 15-32 cm long (mean = 22.48 cm) with a diameter between 2.7-3.4 mm (mean = 3.22 mm); the MSCNs were 17-31 cm long (mean = 20.42 cm) with a diameter between 2.3-2.5 mm (mean = 2.41 mm). Clinically, the SN is widely used for both diagnostic (biopsy and nerve conduction velocity studies) and therapeutic purposes (nerve grafting) and the LSCN is used for a sensate free flap; thus, a detailed knowledge of the anatomy of the SN and its contributing nerves are important in carrying out these and other procedures.     

Anatomical variations of the brachial plexus

Important variations exist in the brachial plexus (Kaufmann, Cunningham, Kerr, Lee). Perivascular techniques of brachial plexus block used sometimes use important quantities of anaesthesia product. It seems that certain surgical treatment failures of brachial plexus lesions are related to the brachial plexus variations (Bonnel). Our aim is to study the brachial plexus variations and its relations from the cervical region to brachial region. We dissected twenty-three brachial plexus (13 women and 10 men, fresh or injected by formalin). We studied the brachial plexus anatomic variations and its relations. We found the anatomic variations at the level of different parts of brachial plexus: Trunk: 8 cases (34.8%); Terminal branch: 8 cases (34.8%); brachial plexus tract: 1 case (4.3%); collateral branch: 1 case (4.3%); in 5 cases we didn't find any abnormalities. Some studies show the frequency of 4th cervical root (C4) participation in brachial plexus. Kerr found 65.9%. It was 30.4% of C4 participation in brachial plexus in our series. Among the 8 cases of terminal branch variations in our series, two (8.7%) musculocutaneous was low source. The brachial plexus variations could fail the brachial plexus loco-regional anaesthesia. In the surgical treatment of brachial plexus lesions, the surgeon must know brachial plexus anatomical variations perfectly.     

Anatomical variations of the human sural nerve and its role in clinical and surgical procedures

The sural nerve is the most commonly nerve used in nerve transplantation, and so the aim of this study was to determine the variations of the sural nerve in the back of the leg, its relations to the calcaneal tendon and lateral malleolus, and determine the patterns of its distribution on the dorsum of the foot. Twenty‐four Egyptian legs and feet were dissected. The results showed that the sural communicating nerve connected with the sural nerve in 87.5%. The predominant site of union between these two nerves was in the lower one‐third of the leg and ankle region (62%). There was only one right leg that the sural nerve passed through the gastrocnemius. The small saphenous vein passed along the medial side of the sural nerve in 100%. The sural nerve crossed the lateral border of the calcaneal tendon in 50%. The distance between the sural nerve and insertion of calcaneal tendon was 16 + 7 mm in 91.7%. There were four types of pattern of innervation of the toes by the sural nerve. The predominant pattern was type I (45.8%), where the lateral side of the little toe was supplied by the sural nerve alone. The second pattern was type IV (29.2%), where the lateral 2 ½ toes were supplied by the sural nerve alone. These findings are important for sural nerve biopsy and grafts, surgical repair of the calcaneal tendon, and regional anesthesia of the foot. Clin. Anat. 24:237–245, 2010. © 2010 Wiley‐Liss, Inc.     

The distribution of enkephalins in human carotid bodies showing cellular proliferation and chronic glomitis

Human carotid bodies obtained at necropsy that showed prominence of either the sustentacular cell or the dark variant of chief cell or chronic carotid glomitis were studied by an immunogold labeling technique. The peptides methionine and leucine enkephalin had a similar distribution to that found in the normal human carotid body. They were localized prominently and predominantly in the dark and progenitor variants of chief (type I) cells. The sustentacular (type II) cells showed no immunoreactivity for the enkephalins. Cell counts on immunolabeled chief cells in cases of sustentacular cell hyperplasia and chronic carotid glomitis were found to be at the lower end of the normal range, whereas those in dark cell prominence occurred nearer the upper limit.     

Anatomical variations of the second thoracic ganglion

In recent years the second thoracic ganglion has gained anatomical significance as an important conduit for sympathetic innervation of the upper extremity. Thoracoscopic excision of the second thoracic ganglion is now widely recognized as affording the most effective treatment option for palmar hyperhidrosis. This study recorded the incidence, location and associated additional neural connections of the second thoracic ganglion. Bilateral dissection of 20 adult cadavers was undertaken, and all neural connections of the second thoracic ganglion were recorded. Nineteen cadavers (95%) demonstrated additional neural connections between the first thoracic ventral ramus and second intercostal nerve. These were classified as either type A (47.5%) or type B (45%) using the intrathoracic ramus (nerve of Kuntz) between the second intercostal nerve and the ventral ramus of the first thoracic nerve as a basis on both right and left sides. The second thoracic ganglion was commonly located (92.5%) in the second intercostal space at the level of the intervertebral disc between the second and third thoracic vertebrae. Fused ganglia between the second thoracic and first thoracic (5%) and stellate (5%) ganglia were noted. These findings should assist the operating surgeon with a clear knowledge of the anatomy of the second thoracic ganglion during thoracoscopic sympathectomy with a view to improving the success rate for upper limb sympathectomy.     

Investigation of the bifurcation level of the common carotid artery and variations of the branches of the external carotid artery in human fetuses.

Variations in the position of the bifurcation of the common carotid artery (CCA) and the origin or branching pattern of the external carotid artery (ECA) are well known and documented. In this study, the bifurcation levels of the CCA and origin variations of the branches of the ECA have been extensively investigated in human fetuses. Bilaterally, 40 carotid bifurcations and 40 ECA and their branches have been examined. A latex solution, which had been diluted with water at a ratio of 25% and colored with red India ink, was injected into the aortic arch. Fetuses were kept at room temperature for 24 h before the ECA and its branches were dissected under the microsurgery microscope. Cases of variation were determined and photographed. The bifurcation level of the CCA was determined to be 55% at the C3 level, 35% at the C4 level, 10% at the C5 level on the right side and 60% at the C3 level, 40% at the C4 level on left side. The distribution of the ECA trunks was determined as follows: A linguofacial trunk was present in 20% of the cases, a thyrolingual trunk in 2.5%, a thyrolinguofacial trunk in 2.5% and an occipitoauricular trunk in 12.5%. Beyond this the ascending pharyngeal artery (APA) was observed in one fetus to originate from the internal carotid artery (ICA). Knowledge of variations in the origin and course of the ECA and its branches is of great importance in surgery and radiological examinations.