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 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. (Folia Morphol 2008; 67: 135–142

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. (Folia Morphol 2008; 67: 129–13

Evaluation of coronary dominance in pigs; a comparative study with findings in human hearts

Coronary dominance in swine has been poorly evaluated. The frequencies of each type of dominance have been described, but few details have been given as to the different expressions of each one. The aim of this study was to characterize coronary dominance in commercial breed swine. One hundred and fifty eight pig hearts were evaluated. The coronary arteries (CA) were infused with synthetic resin (Palatal 85% and Styrene15%) through the ostia after channeling. The coronary artery that gives origin to the posterior interventricular artery (PIA), and the site of termination of both the circumflex arteries (CXA), and left retroventricular branch (LRVB) were determined in order to establish the coronary dominance pattern. Right coronary dominance was found in 105 hearts (66.5%), and a balanced circulation in 53 specimens (33.5%). No dominance was observed for the left coronary artery in the hearts studied. The CXA ended on the posterior aspect of the left ventricle in 101 samples (64%) and on the crux cordis in 55 specimens (34.8%). In two specimens (1.3%) it ended as a left marginal artery. In all cases the PIA was a branch of the RCA, and was long in 105 hearts (66%), 55% of which corresponded to males and 45% to females, but this difference was not statistically significant (p=0.77). The AIA ended on the apex in 126 specimens (80%), 71 of which (56%) corresponded to males and 55 (44%) to females (p=0.74). Regarding right coronary dominance, subtype I was observed in 98 specimens (93.3%), subtype II in 5 cases (4.8%), whereas subtype III was observed in 2 hearts (1.9%). Knowing coronary dominance patterns and their irrigation territories is useful for training purposes based on the use of experimental and hemodynamic models with this animal species

Morphological expression of the pig coronary sinus and its tributaries: A comparative analysis with the human heart

The objective of this study was to determine the morphological expression of the coronary sinus and its tributary branches in pigs. This descriptive cross-over study evaluated continuous variables with t test, and discrete variables with the Pearson