Two cases of combined anatomical variations: maxillofacial trunk, vertebral, posterior communicating and anterior cerebral atresia, linguofacial and labiomental trunks.

BACKGROUND: Commonly, arterial anatomic variants are reported as single entities. However, different such variants can occur in a single patient. MATERIALS AND METHODS: During a retrospective study of computed tomography angiograms of 52 adult patients, 2 cases were found with unilateral maxillofacial trunks. In each case different other anatomic variants were documented. RESULTS: The maxillofacial trunk in the first case was associated with bilateral posterior kinks of the internal carotid artery which passed beyond the transverse processes of the atlas vertebra and indented and displaced the internal jugular veins. Common carotid origins of the superior thyroid arteries were found, as well as a high origin of the contralateral facial artery. In the second case a plethora of variants were associated with a unilateral maxillofacial trunk: 1) direct occipital-vertebral arterial anastomosis; 2) ipsilateral atresia of the distal vertebral artery and of the A1 segment of the anterior cerebral artery; 3) bilateral atresia of posterior communicating arteries; 4) linguofacial and labiomental trunks; 5) terminal trifurcation of the external carotid artery. CONCLUSIONS: The arterial anatomical variants of the head and neck should be carefully documented prior to specific surgical and interventional procedures, as well as for understanding the compensatory anatomical pathways of circulatory insufficiencies.

Hexafurcated coeliac trunks, trifurcated common hepatic artery, and a new variant of the arc of Bühler.

BACKGROUND: The coeliac trunk (CT) is well-known as trifurcated into the left gastric (LGA), common hepatic (CHA) and splenic (SA) arteries. MATERIALS AND METHODS: Scarce reports indicate that the CT could appear quadri-, penta-, hexa-, or even heptafurcated. Reports of CTs with six branches (hexafurcated CT) are few, less than ten. The hexafurcated CT variant was documented by a retrospective study of 93 computed tomography angiograms. RESULTS: Two hexafurcated CTs were found. In one case an arc of Bühler was added to the inferior phrenic arteries, LGA, CHA and SA. In the second case the dorsal pancreatic artery was added to the other five branches. That arc of Bühler descended in front of the aorta to connect with the origin of the third jejunal artery. The CHA in that second case was trifurcated into the left and right hepatic arteries, and the gastroduodenal artery; the proper hepatic artery was absent. CONCLUSIONS: Although the hexafurcated CT, as well as the trifurcated CHA, are rarely occurring and reported anatomic variants, this doesn't mean they could not be encountered during surgical or interventional procedures, which they would complicate if not recognised. Moreover, the arc of Bühler, the embryonic remnant, was not reported previously to insert into the CT as an additional branch of it.

Hepatomesenteric trunk, gastrosplenic trunk, coiled splenic and hepatic arteries, and a variant of Bühler's arc.

The coeliac trunk is normally divided into the left gastric artery (LGA), splenic artery, and common hepatic artery (CHA). The combination between these arteries and the superior mesenteric artery (SMA) generates various combinations. We report here such a rare anatomic variant, namely the hepatomesenteric trunk (HMT), combined with a gastrosplenic trunk (GST). The variant was identified using computed tomography angiograms of a 62-year-old woman. The GST emerged from the aorta within the aortic hiatus of the diaphragm, a previously unknown possibility. Further, an accessory left hepatic artery originated from the LGA. The phrenic arteries had independent aortic origins. The HMT divided into the CHA and the SMA posterior to the origin of the hepatic portal vein (PV), above the pancreas. The CHA initially had a right course, towards the superior border of the PV, then it descended with a transpancreatic course posterior to the PV, reached its inferior/right border, and divided antero-inferiorly to the PV into the proper hepatic and gastroduodenal arteries. The proper hepatic artery continued on the anterior side of the PV, sending off the left and right hepatic arteries. The HMT and the GST were connected by a rudimentary variant of the arc of Bühler, unreported previously. Arterial variations in the coeliac region are accurately distinguished on computed tomography angiograms. They should be evaluated by surgeons when different surgical procedures are evaluated.

A glimpse of past, the temporo-buccinator band of Hovelaque, or the buccotemporal fascia of Zenker.

Only a few studies published until now have described the fascial-tendinous complex between the temporal and the buccinator muscles, which will be reviewed here. In 1957, the "temporo-buccinator band" (TBB) was described by Gaughran, who gave credit to Hovelaque for its first description in 1914. Zenker coined it in 1955 as the "buccotemporal fascia" (BTF). A buccal extension of the temporal muscle tendon extends from the temporal crest of the mandible to insert within the buccinator muscle, anterior to the pterygomandibular raphe, and posterior to the parotid duct that perforates the buccinator. That tendinous expansion is embedded within the buccotemporal fascia, which is oriented antero-infero-medially and joins the buccopharyngeal fascia, forming the TBB/BTF, above which we find the buccal fat pad. The buccal nerve and artery cross this anatomical structure. The TBB/BTF is an additional layer closing the pterygomandibular space anteriorly, and its knowledge is needed for practitioners performing inferior alveolar nerve blocks.

The ultrastructural anatomy of the nuclear envelope in the masseter muscle indicates its role in the metabolism of the intracellular Ca+.

Specific ultrastructural anatomy of masticatory muscles is commonly referred to a general pattern assigned to striated muscles. Junctional feet consisting of calcium channels of the sarcoplasmic reticulum (i.e. the ryanodine receptors, RyRs) physically connected to the calcium channels of the t-tubules build triads within striated muscles. Functional RyRs were demonstrated in the nuclear envelopes of pancreas and of a skeletal muscle derived cell line, but not in muscle in situ. It was hypothesized that ryanodine receptors (RyRs) could also exist in the nuclear envelope in the masseter muscle, thus aiming at studying this by transmission electron microscopy. There were identified paired and consistent subsarcolemmal clusters of mitochondria, appearing as outpockets of the muscle fibers, usually flanking an endomysial microvessel. It was observed on grazing longitudinal cuts that the I-band-limited mitochondria were not strictly located in a single intermyofibrillar space but continued transversally over the I-band to the next intermyofibrillar space. It appeared that the I-band-limited transverse mitochondria participate with the column-forming mitochondria in building a rather incomplete mitochondrial reticulum of the masseter muscle. Subsarcolemmal nuclei presented nuclear envelope-associated RyRs. Moreover, t-tubules were contacting the nuclear envelope and they were seemingly filled from the perinuclear space. This could suggest that nucleoplasmic calcium could contribute to balance the cytosolic concentration via pre-built anatomical routes: (i) indirectly, via the RyRs of the nuclear envelope and (ii) directly via the communication of t-tubules and sarcoplasmic reticulum through the perinuclear space.

An unusual case of unilateral supernumerary extensor carpi radialis muscle.

An uncommon anatomical variant of muscle that can be considered as a supernumerary extensor carpi radialis muscle was found during the dissection of the forearm region. The identified extensor carpi radialis muscle has origin on the lateral supraepicondylar ridge of the humerus, and an unusual insertion on the tubercle of the scaphoid bone. The presence of this supernumerary muscle may cause diagnostic errors in the forearm region, and can produce a debilitating pain syndrome by secondary compression of adjacent nerves, vessels or tendons due to its course along the anterior compartment of the forearm.

Telocytes of the mammary gland stroma.

Although confusions persist in what concerns the terminologies used for describing the fibroblastoid cells of the stromal compartments, the expression of antigens in such cells gradually directs their diagnosis towards a stem/progenitor phenotype. The stromal cells with long, slender and moniliform prolongations were named "telocytes" (TCs), their cell processes being termed "telopodes". However, the mammary gland TCs were not evaluated for the CD34 expression. Thus an in vivo immunohistochemical study was designed; antibodies against CD10, CD34, CD117/c-kit and vimentin were applied on human mammary gland samples of 8 donor patients. Resident CD34-positive stromal cells positive for the TCs morphology were found building consistent stromal networks and ensheathing microvessels and excretory units. Such cells were CD10±/c-kit-/vimentin+. According to the current concepts regarding the in vivo stem/progenitor cells the CD34+ TCs of the mammary stroma could be actors in the mammary stem niche and their antigens expression could relate to different stages of differentiation.

Telocytes form networks in normal cardiac tissues.

Telocytes (TC) are a class of interstitial cells present in heart. Their characteristic feature is the presence of extremely long and thin prolongations (called telopodes). Therefore, we were interested to see whether or not TCs form networks in normal cardiac tissues, as previously suggested. Autopsy samples of cardiac tissues were obtained from 13 young human cadavers, without identifiable cardiac pathology and with a negative personal history of cardiovascular disease. Immunohistochemistry on formalin-fixed paraffin-embedded tissues was performed using monoclonal antibodies for CD117/c-kit. Additionally, ventricular samples from 5 Sprague-Dawley rats were ultrastructurally evaluated under transmission electron microscopy. We found c-kit positive cells with TC features in subepicardium, as well in subepicardial arteries and in subepicardial fat. TCs were also present in the subendocardium. Light and electron microscopy revealed the existence of intramyocardial networks built up by bipolar TCs. Larger c-kit positive multipolar TCs were found between cardiac muscle bundles. Our results support the existence of a cardiac network of telocytes.

Anatomical and immunohistochemical considerations on the microinnervation of trachea in humans.

The anatomy of the tracheal microinnervation is understudied in humans; the purpose of our study was to fill this gap by working on human adult tracheas, to compare the results with those obtained from animal studies, and to checking whether or not these studies are suitable to be translated from comparative to the human anatomy. The study was designed as a qualitative one. The present work was performed on human adult tracheas dissected out in 15 human adult cadavers. Microdissections were performed in eight tracheas and revealed the outer peritracheal plexus, segmentally supplied and distributed to trachea and esophagus, with longitudinal intersegmentary anastomoses but also with bilateral interrecurrential anastomoses previously undescribed in anatomy. Seven different tracheas were transversally cut and paraffin embedded. Histological stains (HE, toluidine blue, luxol fast blue, Giemsa on tissues and trichrome Gieson) and immunohistochemistry using primary antibodies for nNOS, neurofilament, SMA and the cocktail of citokeratines CK AE1-AE3+8/18 were done. According to the histological individual variation, the neural layers of the posterior wall of the human trachea could be considered as it follows: (a) an outer neural layer, ganglionated, associated with the connective covering layers, adventitia and the posterior fibroelastic membrane (external elastic lamina); (b) a submucosal ganglionated neural layer, mainly with juxtaglandular microganglia that may expand, as glands do, through the outer covering layers; (c) intrinsic nerves of the transverse trachealis muscle; (d) the neural layer intrinsic to the longitudinal elastic band (internal elastic lamina) and supplied from the inner submucosa; (e) the neural plexus of the lamina propria, with scarcely distributed neurons. We also bring here the first evidences for the in vivo nNOS phenotype of mast cells that were identified, but not exclusively, within the trachealis muscle.

The iliolumbar artery-anatomic considerations and details on the common iliac artery trifurcation.

The iliolumbar artery (ILA) of Haller is the largest nutrient pedicle of the ilium and its detailed knowledge is important for various surgical procedures that approach the lumbosacral junction, the L4/L5 disk space, the sacroiliac joint, the iliac and psoas muscles, or the lumbar spine. Also the ILA is relevant for various techniques of embolization. We aimed to evaluate the anatomic and topographic features of the ILA, by dissection on 30 human adult pelvic halves and on 50 angiograms. ILA was a constant presence and it emerged at Level A (from the common iliac artery (CIA), 8.75%), Level B (from the CIA bifurcation, 2.5%), Level C (from the internal iliac artery (IIA), 52.5%), Level D (from the IIA bifurcation, 3.75%), and Level E (from the posterior trunk of the IIA, 32.5%). Level B of origin of the ILA corresponds to a trifurcated CIA (morphology previously unreported), while Level D corresponds to a trifurcated IIA. A higher origin of the ILA corresponds to a more transversal course of it. A descending lumbar branch that leaves the iliac arterial system independently to enter the psoas major muscle, as seen in 48% of cases, may be misdiagnosed as ILA. Surgical interventions in the lumbar, sacral, and pelvic regions must take into account the variable origins of the ILA from the iliac system that can modify the expected topographical relations and may lead to undesired hemorrhagic accidents.