RESUMO
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.
Assuntos
Artéria Carótida Externa , Círculo Arterial do Cérebro , Adulto , Artéria Carótida Interna , Humanos , Estudos Retrospectivos , Coluna VertebralRESUMO
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.
Assuntos
Artéria Celíaca , Artéria Hepática , Artéria Celíaca/diagnóstico por imagem , Artéria Hepática/diagnóstico por imagem , Artéria Mesentérica Superior , Estudos Retrospectivos , Artéria EsplênicaRESUMO
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.
Assuntos
Cálcio/metabolismo , Músculo Masseter/metabolismo , Músculo Masseter/ultraestrutura , Animais , Núcleo Celular/ultraestrutura , Masculino , Microscopia Eletrônica de Transmissão , Microvasos/ultraestrutura , Mitocôndrias/ultraestrutura , Modelos Animais , Fibras Musculares Esqueléticas/ultraestrutura , Miofibrilas/ultraestrutura , Membrana Nuclear/ultraestrutura , Coelhos , Sarcolema/ultraestrutura , Sarcômeros/ultraestruturaRESUMO
Probably, the most variable anatomic pattern relates to the iliac arteries system. There are reported here multiple rare anatomic variants found in a single case, at CT evaluation: (a) the unilaterally present common trunk of origin of the obturator, inferior epigastric, and medial circumflex femoral arteries and (b) the medial insertion of the deep femoral artery (DFA) onto the femoral artery, which placed the DFA initially on the medial side of the femoral vein. Such rare, but possible, anatomic variations should recommend surgeons to plan the procedures on a case-by-case basis.
Assuntos
Artérias/anatomia & histologia , Artérias Epigástricas/anatomia & histologia , Artéria Femoral/anatomia & histologia , Artéria Ilíaca/anatomia & histologia , Variação Anatômica , Artérias/diagnóstico por imagem , Meios de Contraste , Humanos , Imageamento Tridimensional , Masculino , Pessoa de Meia-Idade , Tomografia Computadorizada por Raios XRESUMO
UNLABELLED: Cholecystectomy is considered to be the treatment of choice in symptomatic biliary lithiasis. Lately, due to medical progress, classic cholecystectomy has been gradually replaced by laparoscopic cholecystectomy and by mini cholecystectomy. Therefore, it is very important to determine certain preoperative factors which might predict the conversion of mini cholecystectomy (MC) into classic cholecystectomy (CC). MATERIAL AND METHOD: The possibility of selecting high-risk conversion patients has important clinical implications, both for the surgeon and for the patient. Differentiating preoperative risk allows the surgeon to inform the patient about a high conversion risk to CC, and about the ensuing consequences: longer hospitalization period, longer postoperative recovery, greater costs. All the patients were examined by ultrasonography. The tests recorded six parameters: the diameter of the biliary duct (mm), the number of calculi, the diameter of the largest calculus (mm), the contracted aspect of the gallbladder, the distance between the tegument and the gallbladder fundus (cm), the distance between the tegument and the cystic duct (cm). All the variables were introduced into an initial model, which was checked using the colinearity method and significant observations, and subsequently reduced by eliminating insignificant predictive factors, revealed by Wald tests. RESULTS: The significant predictive conversion factors to CC, quantified on the basis of regression analysis, are: age > 70, calculus with a diameter > 20 mm, biliary duct with a diameter > 6 mm, contracted gallbladder, distance between the tegument and gallbladder fundus > 7.2 cm, distance between the tegument and cystic duct > 17.1 cm. CONCLUSION: Being a procedure that can be carried out on an outpatient basis and with rather low costs, ultrasonography plays a very important role in the preoperative prediction of converting MC to CC.