Morphologic characterization of the anterior inferior cerebellar artery: a direct anatomic study

OBJECTIVE

An adequate knowledge of the anterior inferior cerebellar artery (AICA) is oriented to the morphological sciences, clinical management and surgical planning of the posterior fossa. We aimed to determine the morphology of AICA in a sample from Colombian population.

METHOD

We studied 92 AICA from fresh cadavers. For each specimen, the vertebral arteries were injected with 100 cc of semi-synthetic resin (a mixture of Palatal E210® BASF 80 cc and Styrene 20 cc) dyed with mineral red. The biometrics and morphological variables of AICA were registered.

RESULTS

AICA originated at 9.9 ± 3.2 mm from the vertebrobasilar junction. In 12 samples (8.1%), we observed a common trunk between AICA and posterior inferior cerebellar artery, which presented a caliber of 1.56 ± 0.23 mm and a length of 11.3  ± 3. 53 mm. In 80 (51.3%) specimens, AICA was originated from the proximal segment of basilar artery, while in 76 (48.7%) of them emerged from the medium segment. The AICA bifurcation distance from its origin was less than 20 mm in 20.5% of cases; between 20 and 40 mm in 62.3%. In its trajectory, AICA passed ventral to the facial nerve in 85 samples (53.2%), dorsal to the facial nerve in 68 samples (43.6%) and between the roots in 5 samples (3.2%).

CONCLUSIONS

The origin of the AICA from the proximal segment of the basilar artery is confirmed in this study, which disagrees with reports that point out its origin in the middle segment.

Accessory head of the flexor pollicis longus muscle: anatomical study and clinical significance

BACKGROUND

The accessory head of the flexor pollicis longus (AHFPL) has an oblique trajectory from medial to lateral aspect of the forearm below the flexor digitorum superficialis muscle and then joins the flexor pollicis longus muscle. When the anterior interosseous nerve (AIN) courses underneath the muscle belly of the AHFPL an entrapment neuropathy may occur, known as anterior interosseous nerve syndrome (AINS).

MATERIALS AND METHODS

This descriptive cross-sectional study evaluated 106 fresh upper extremities. When the AHFPL was present, its fascicle was traced up to evaluate the origin site. The morphometric variables were measured using a digital micrometre (Mitutoyo, Japan). The relationship between the AHFLP and the AIN was evaluated.

RESULTS

The AHFPL was found in 34 (32.1%) of the 106 forearms. The AHFPL arose from the flexor digitorum superficialis muscle in 16 (47.1%) forearms, the medial epicondyle of the humerus in 10 (29.4%) forearms and the coronoid process of ulna in 8 (23.5%) forearms. The average total length of the AHFPL was 94.11 ± ± 10.33 mm. The AIN was located lateral to the AHFPL in 3 (8.8%) forearms, posterolateral in 7 (20.6%) forearms and posterior in 24 (70.6%) forearms.

CONCLUSIONS

This study performed in a South American population sample revealed a prevalence of the AHFPL in a lower range compared to previous studies in North Americans and Asians. The AIN coursed more frequently underneath the muscle belly of AHFPL. This finding has clinical significance in the onset of the AINS and the subsequent surgical procedure for the AIN decompression.

Morphological characterisation of the coronary arteries in African sheep (Ovis orientalis). Differential analysis with those of humans and other animal species

BACKGROUND

Despite the importance of the coronary system in the African sheep as a possible experimental model, there is little information about this particular vascular system. The objective of this investigation was to characterise morpho- logically the coronary arteries and their branches in African sheep.

MATERIALS AND METHODS

This descriptive cross-sectional study evaluated the coronary arteries and their branches of 62 hearts of short hair sheep. The right and left coronary ostia were perfused with a semi-synthetic resin (Palatal GP40L 85%; styrene 15%) dyed with mineral red. The morphological characteristics were evaluated using a digital calibrator and the biometrics of the coronary arteries and their branches were registered.

RESULTS

The right coronary artery had a proximal calibre of 2.11 ± 0.46 mm. The subsinusal interventricular branch ended at the middle third of the homonym sulcus in 19 (30.6%) specimens. The left coronary artery had a diameter of 5.38 ± ± 1.59 mm and a length of 4.67 ± 3.32 mm. This artery bifurcated itself in the paraconal interventricular branch and the left circumflex branch in 57 (91.9%) hearts and trifurcated with an additional left diagonal branch in 5 (8.1%) spec- imens. Left coronary artery dominance was observed in 51 (82.3%) specimens, whereas in 11 (17.7%) cases the coronary circulation dominance was balanced.

CONCLUSIONS

Due to the similitude in the features of the coronary arteries between African sheep and humans, this animal model can be proposed for procedural and haemodynamic activities.

Characterisation of myocardial bridges in pigs: a comparative anatomical analysis with the human heart

BACKGROUND

Few studies have been conducted in pigs concerning the presence of myocardial bridges (MB) on the coronary arteries and their branches, and some of them have evaluated small samples. The objective of this study was to characterise MB in pigs of commercial breeds.

MATERIALS AND METHODS

One hundred and fifty eight hearts of pigs destined to the slaughterhouse with stunning method were studied. The coronary arteries were perfused with polyester resin (palatal 85% and styrene 15%) and then subjected to potassium hydroxide infusion to remove the subepicardial fat.

RESULTS

Ninety three MB were found in 67 (42.4%) specimens, 43 (46%) of which were located on branches of the right coronary artery, 38 (41%) on branches of the left coronary artery and 12 (13%) on both vessels. The MB occurred in 26 (38.8%) females and 41 (61.2%) males, but the difference was not statistically significant (p = 0.23). Single MB were most common (70%), followed by the presence of 2 (21%) MB in different vessels. the subsinusal interventricular artery was the vascular structure with the largest number of MB (46.2%), with its middle third being the most compromised segment (79%). The mean length of the MB was 11.23 ± 5.67 mm and the thickness of the suprapontine myocardium was 1.13 ± 0.48 mm.

CONCLUSIONS

The frequency, localisation, and length of the MB reported in pigs are consistent with the findings of the present study, whereas in humans the MB involve mainly the anterior interventricular artery and are longer.

Evaluation of additional head of biceps brachii: a study with autopsy material

Additional head of the biceps brachii (AHBB) has been reported in different population groups with a frequency of 1-25%. The purpose of this study was to determine the incidence and morphologic expression of the AHBB as determined in a sample of the Colombian population. An exploration was conducted with 106 arms corresponding to unclaimed corpses autopsied at Institute of Legal and Forensic Medicine of Bucaramanga, Colombia. Using medial incision involvingskin, subcutaneous tissue, and brachial fascia, the heads of the biceps and their innervating branches were visualised. One AHBB was observed in 21 (19.8%) of the arms evaluated, with non-significant difference (p = 0.568) per side of presentation: 11 (52.4%) cases on the right side and 10 (47.6%) on the left side. All AHBBs were originated in the infero-medial segment of the humerus, with a mean thickness of 17.8 ± 6.8 mm. In 4 (19%) cases the fascicle was thin, less than 10 mm; in 7 (33.3%) cases it was of medium thickness, between 11 and 20 mm, whereas in 47.6% it was longer than 20 mm. The length of the AHBB was 118.3 ± 26.8 mm; its motor point supplied by the musculocutaneous nerve was located at 101.3 ± 20.9 mm of the bi-epicondylar line. The incidence of AHBB in this study is located at the upper segment of what has been reportedin the literature and could be a morphologic trait of the Colombian population; in agreement with prior studies, the origin was the infero-medial surface of the humerus.

Morphological expression of the left coronary artery: a direct anatomical study

The left coronary artery presents wide variability in its morphological expression. The purpose of this work was to determine the variations in the left coronary artery and those of its branches in heart samples taken from a group of 154 Colombian mixed-race people. Cadaveric coronary arteries were injected with synthetic resins. Left coronary artery trunks presented 6.48 +/- 2.57 mm lengths. Left coronary arteries were bifurcated in 80 hearts (52%), trifurcated in 65 hearts (42.2%) and tetrafurcated in 9 hearts (5.8%). A short circumflex branch was observed in 143 hearts (92.8%), finalising as a left marginal branch in 39 of them (25.3%). The inferior third of the posterior interventricular sulcus was the most frequently occurring segment in anterior interventricular branch finalisation (63.6%). The calibre of the left coronary artery trunk was 3.58 +/- +/- 0.59 mm, that of the anterior interventricular branch 2.94 +/- 0.5 mm and that of the circumflex branch 2.71 +/- 0.54 mm. Of the total sample 86 myocardial bridges were observed with 61 cases (70.9%) in the anterior interventricular branch, distributed amongst all segments (proximal, intermediate and distal). Average myocardial bridge length was 19.4 +/- 10.7 mm, and no gender differences were observed (p = 0.20). The most frequently occurring location of the myocardial bridges, on the anterior interventricular branch (proximal and intermediate), agreed with previous studies. Left coronary artery trunk length and calibre and that of its branches were considerably smaller than those reported in other populations. (

A direct anatomical study of additional renal arteries in a Colombian mestizo population

Traditional anatomy describes each kidney as receiving irrigation from a single renal artery. However, current literature reports great variability in renal blood supply, the number of renal arteries mentioned being the most frequently found variation. Such variation has great implications when surgery is indicated, such as in renal transplants, uroradiological procedures, renovascular hypertension, renal trauma and hydronephrosis. This article pretends to determine the frequency of additional renal arteries and their morphological expression in Colombian population in a cross-sectional study. A total of 196 of renal blocks were analysed from autopsies carried out in the Bucaramanga Institute of Forensic Medicine, Colombia; these renal blocks were processed by the injection- corrosion technique. The average age of the people being studied was 33.8 +/- 15.6 years; 85.4% of them were male and the rest female. An additional renal artery was found in 22.3% of the whole population and two additional ones were found in 2.6% of the same sample. The additional renal artery was most frequently found on the left side. The additional artery arose from the aorta's lateral aspect (52.4%); these additional arteries usually entered the renal parenchyma through the hilum. No difference was established according to gender. Nearly a third of the Colombian population presents one additional renal artery and about 3% of the same population presents two additional renal arteries. Most of them reached the kidney through its hilar region.

[Anatomical and pathological study of the temporomandibular joint disk in Colombian individuals]

BACKGROUND

The temporomandibular joint is an oval fibrous plate that completely divides the joint and accommodates irregularities existent in the bone articular surfaces.

AIM

To study the frequency of temporomandibular joint disk abnormalities among Colombian subjects.

MATERIAL AND METHODS

We studied 120 temporomandibular joint disks obtained from fresh cadavers arrived in the Instituto de Medicina Legal, in Cali Colombia. These were analyzed according to subject's dental status and age.

RESULTS

Nineteen percent of disks had small erosions. In 7.5% of disks there were wider erosions or perforations. Twenty six percent of discs were very thin and this alteration was seen mostly in people aged 50 years or older.

CONCLUSIONS

These results are intermediate between those who claim that disk perforations are rare and those who had shown tile opposite. The loss of dental pieces seems to be a risk factor leading to such disk perforation.