Browsing by Author "Pais, D"
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- Anatomical Basis, Histological Findings and Hemodinamics in the Modern Perfusion Model for Human CorpsesPublication . Júnior, E; Bettencourt-Pires, M; Alves, S; Casal, D; Pais, D; Goyri O’neill, J; Vassilenko, VsSeveral modern human cadaveric fixation methods are subject to permanent evaluation. Formaldehyde is the oldest and still the most widely used method of embalming. However, the International Agency for Research on Cancer has proven its high carcinogenic potential and its use was banned, with the recommendation of research for better alternatives in the conservation of corpses. The embalming method of excellence, which preserves all features, while keeping the disinfectant properties against cadaveric decomposition was proposed by João Goyri O’Neill. Their method was considered “the most modern and efficient technique in cadaveric preservation”. The aim of this present study was to analyze the quality of this original perfusion technique, at the organic level, based on central and peripheral hemodynamics. The cadaveric material was embalmed through a pulsed arterial perfusion system, connected to an automatic intermittent pump, that permits stability of the microvascular network, as well as the computerized measurement of the main perfusion parameters, such as flow and pressure. This procedure ensures good preservation of color, elasticity, texture, flexibility and fresh appearance, for several years. The morphological characteristics of the organs exhibited astonishing similarity to the living organic tissues, even several years after embalming and high freezing. Microscopic analysis demonstrated preservation of the structure of vessels, such as the aorta. Further studies on the integrity of the endocardial layer of the heart will enable to adapt the intermittent perfusion pump system to best simulate cardiac rhythm and arterial pulse, during cadaveric surgical training.
- BD-2 and BD-3 Increase Skin Flap Survival in a Model of Ischemia and Pseudomonas Aeruginosa InfectionPublication . Casal, D; Iria, I; Ramalho, JS; Alves, S; Mota-Silva, E; Mascarenhas-Lemos, L; Pontinha, C; Guadalupe-Cabral, M; Ferreira-Silva, J; Ferraz-Oliveira, M; Vassilenko, V; Goyri-O'Neill, J; Pais, D; Videira, PThe main aim of this work was to study the usefulness of human β-defensins 2 (BD-2) and 3 (BD-3), which are part of the innate immune system, in the treatment of infected ischemic skin flaps. We investigated the effect of transducing rat ischemic skin flaps with lentiviral vectors encoding human BD-2, BD-3, or both BD-2 and BD-3, to increase flap survival in the context of a P. aeruginosa infection associated with a foreign body. The secondary endpoints assessed were: bacterial counts, and biofilm formation on the surface of the foreign body. A local ischemic environment was created by producing arterialized venous flaps in the left epigastric region of rats. Flaps were intentionally infected by placing underneath them two catheters with 105 CFU of P. aeruginosa before the surgical wounds were hermetically closed. Flap biopsies were performed 3 and 7 days post-operatively, and the specimens submitted to immunohistochemical analysis for BD-2 and BD-3, as well as to bacterial quantification. Subsequently, the catheter segments were analyzed with scanning electron microscopy (SEM). Flaps transduced with BD-2 and BD-3 showed expression of these defensins and presented increased flap survival. Rats transduced with BD-3 presented a net reduction in the number of P. aeruginosa on the surface of the foreign body and lesser biofilm formation.
- Blood Supply to the Integument of the Abdomen of the Rat: A Surgical PerspectivePublication . Casal, D; Pais, D; Iria, I; Videira, P; Mota-Silva, E; Alves, S; Mascarenhas-Lemos, L; Pen, C; Vassilenko, V; Goyri-O'Neill, JBACKGROUND: Many fundamental questions regarding the blood supply to the integument of the rat remain to be clarified, namely the degree of homology between rat and humans. The aim of this work was to characterize in detail the macro and microvascular blood supply to the integument covering the ventrolateral aspect of the abdominal wall of the rat. METHODS: Two hundred five Wistar male rats weighing 250-350 g were used. They were submitted to gross anatomical dissection after intravascular colored latex injection (n = 30); conversion in modified Spalteholz cleared specimens (n=10); intravascular injection of a Perspex solution, and then corroded, in order to produce vascular corrosion casts of the vessels in the region (n = 5); histological studies (n = 20); scanning electron microscopy of vascular corrosion casts (n = 10); surgical dissection of the superficial caudal epigastric vessels (n = 100); and to thermographic evaluation (n = 30). RESULTS: The ventrolateral abdominal wall presented a dominant superficial vascular system, which was composed mainly of branches from the superficial caudal epigastric artery and vein in the caudal half. The cranial half still received significant arterial contributions from the lateral thoracic artery in all cases and from large perforators coming from the intercostal arteries and from the deep cranial epigastric artery. CONCLUSIONS: These data show that rats and humans present a great deal of homology regarding the blood supply to the ventrolateral aspect of the abdominal integument. However, there are also significant differences that must be taken into consideration when performing and interpreting experimental procedures in rats.
- Cor Pulmonale por Embolia de Células NeoplásicasPublication . Andrade Gomes, J; Sá, J; Pais, D; Tavares, FOs autores apresentam um caso de Cor Pulmonale por Embolia de Células Neoplásicas em uma doente de 42 anos sem antecedentes conhecidos de doença maligna. A neoplasia primitiva era um coriocarcinoma que não foi encontrado no exame necrópsico. É brevemente discutida a fisiopatologia, achados clínicos e marcha diagnóstica destas situações.
- A Model of Free Tissue Transfer: The Rat Epigastric Free FlapPublication . Casal, D; Pais, D; Iria, I; Mota-Silva, E; Almeida, MA; Alves, S; Pen, C; Farinho, A; Mascarenhas-Lemos, L; Ferreira-Silva, J; Ferraz-Oliveira, M; Vassilenko, V; Videira, P; Gory O'Neill, JFree tissue transfer has been increasingly used in clinical practice since the 1970s, allowing reconstruction of complex and otherwise untreatable defects resulting from tumor extirpation, trauma, infections, malformations or burns. Free flaps are particularly useful for reconstructing highly complex anatomical regions, like those of the head and neck, the hand, the foot and the perineum. Moreover, basic and translational research in the area of free tissue transfer is of great clinical potential. Notwithstanding, surgical trainees and researchers are frequently deterred from using microsurgical models of tissue transfer, due to lack of information regarding the technical aspects involved in the operative procedures. The aim of this paper is to present the steps required to transfer a fasciocutaneous epigastric free flap to the neck in the rat. This flap is based on the superficial epigastric artery and vein, which originates from and drain into the femoral artery and vein, respectively. On average the caliber of the superficial epigastric vein is 0.6 to 0.8 mm, contrasting with the 0.3 to 0.5 mm of the superficial epigastric artery. Histologically, the flap is a composite block of tissues, containing skin (epidermis and dermis), a layer of fat tissue (panniculus adiposus), a layer of striated muscle (panniculus carnosus), and a layer of loose areolar tissue. Succinctly, the epigastric flap is raised on its pedicle vessels that are then anastomosed to the external jugular vein and to the carotid artery on the ventral surface of the rat's neck. According to our experience, this model guarantees the complete survival of approximately 70 to 80% of epigastric flaps transferred to the neck region. The flap can be evaluated whenever needed by visual inspection. Hence, the authors believe this is a good experimental model for microsurgical research and training.
- Morphometric Analysis of the Extensor Tendons of the Hallux and Potential Implications for Tendon GraftingPublication . Casal, D; Pais, D; Almeida, MA; Bilhim, T; Santos, A; Goyri-O'Neill, JAlthough several tendon sources are available for reconstructive surgical procedures, all have one or more shortcomings. The aim of this work was to evaluate if the extensor tendons of the hallux showed anatomical characteristics that could make them an additional source for tendon grafting procedures.The authors performed a detailed morphometric analysis of the extensor tendons of the hallux in 26 lower limbs in order to evaluate the putative association of anatomical variants with hallux valgus, and to attempt to assess the feasibility of using part of the extensor apparatus of the hallux as a source of tendon for grafting procedures.An accessory extensor hallucis longus ten-don was found in 92.3% of cases. The extensor hallucis brevis tendon length was 10.5 ± 0.6 cm; its width was 0.5 ± 0.1 cm, and its thickness varied between 1-2 mm, making it a potentially good candidate as a source of ten-don grafts. Several anatomical variations were observed, namely the fusion of the tendons of the extensor hallucis brevis and the accessory extensor hallucis longus muscles in the distal part of the foot.This new therapeutic option, if implemented, would possibly increase the supply of autogenous donor tissue for reconstructive procedures, thereby enhancing the reconstructive surgeon’s armamentarium.
- Optimization of an Arterialized Venous Fasciocutaneous Flap in the Abdomen of the RatPublication . Casal, D; Mota-Silva, E; Pais, D; Iria, I; Videira, P; Tanganho, D; Alves, S; Mascarenhas-Lemos, L; Martins Ferreira, J; Ferraz-Oliveira, M; Vassilenko, V; Goyri O'Neill, JBACKGROUND: Although numerous experimental models of arterialized venous flaps (AVFs) have been proposed, no single model has gained widespread acceptance. The main aim of this work was to evaluate the survival area of AVFs produced with different vascular constructs in the abdomen of the rat. METHODS: Fifty-three male rats were divided into 4 groups. In group I (n = 12), a 5-cm-long and 3-cm-wide conventional epigastric flap was raised on the left side of the abdomen. This flap was pedicled on the superficial caudal epigastric vessels caudally and on the lateral thoracic vein cranially. In groups II, III, and IV, a similar flap was raised, but the superficial epigastric artery was ligated. In these groups, AVFs were created using the following arterial venous anastomosis at the caudal end of the flap: group II (n = 13) a 1-mm-long side-to-side anastomosis was performed between the femoral artery and vein laterally to the ending of the superficial caudal epigastric vein. In group III (n = 14), in addition to the procedure described for group II, the femoral vein was ligated medially. Finally, in group IV (n = 14), the superficial caudal epigastric vein was cut from the femoral vein with a 1-mm-long ellipse of adjacent tissue, and an end-to-side arterial venous anastomosis was established between it and the femoral artery. RESULTS: Seven days postoperatively, the percentage of flap survival was 98.89 ± 1.69, 68.84 ± 7.36, 63.84 ± 10.38, 76.86 ± 13.67 in groups I-IV, respectively. CONCLUSION: An optimized AVF can be produced using the vascular architecture described for group IV.
- Outcomes and Satisfaction of Two Optional Cadaveric Dissection Courses: a 3-Year Prospective StudyPublication . Pais, D; Casal, D; Mascarenhas-Lemos, L; Barata, P; Moxham, B; Goyri-O'Neill, JTeaching time dedicated to anatomy education has been reduced at many medical schools around the world, including Nova Medical School in Lisbon, Portugal. In order to minimize the effects of this reduction, the authors introduced two optional, semester-long cadaveric dissection courses for the first two years of the medical school curriculum. These courses were named Regional Anatomy I (RAI) and Regional Anatomy II (RAII). In RAI, students focus on dissecting the thorax, abdomen, pelvis, and perineum. In RAII, the focus shifts to the head, neck, back, and upper and lower limbs. This study prospectively analyzes students' academic achievement and perceptions within the context of these two, newly-introduced, cadaveric dissection courses. Students' satisfaction was assessed anonymously through a questionnaire that included items regarding students' perception of the usefulness of the courses for undergraduate teaching, as well as with regards to future professional activity. For each of the three academic years studied, the final score (1 to 20) in General Anatomy (GA), RAI, and RAII was on average 14.26 ± 1.89; 16.94 ± 1.02; 17.49 ± 1.01, respectively. The mean results were lower in GA than RAI or RAII (P < 0.001). Furthermore, students who undertook these courses ranked them highly with regards to consolidating their knowledge of anatomy, preparing for other undergraduate courses, and training for future clinical practice. These survey data, combined with data on participating students' academic achievement, lend strong support to the adoption of similar courses as complementary and compulsory disciplines in a modern medical curriculum.
- A Rare Variant of the Ulnar Artery with Important Clinical Implications: a Case ReportPublication . Casal, D; Pais, D; Toscano, T; Bilhim, T; Rodrigues, L; Figueiredo, I; Aradio, S; Almeida, MA; Goyri-O'Neill, JBACKGROUND: Variations in the major arteries of the upper limb are estimated to be present in up to one fifth of people, and may have significant clinical implications. CASE PRESENTATION: During routine cadaveric dissection of a 69-year-old fresh female cadaver, a superficial brachioulnar artery with an aberrant path was found bilaterally. The superficial brachioulnar artery originated at midarm level from the brachial artery, pierced the brachial fascia immediately proximal to the elbow, crossed superficial to the muscles that originated from the medial epicondyle, and ran over the pronator teres muscle in a doubling of the antebrachial fascia. It then dipped into the forearm fascia, in the gap between the flexor carpi radialis and the palmaris longus. Subsequently, it ran deep to the palmaris longus muscle belly, and superficially to the flexor digitorum superficialis muscle, reaching the gap between the latter and the flexor carpi ulnaris muscle, where it assumed is usual position lateral to the ulnar nerve. CONCLUSION: As far as the authors could determine, this variant of the superficial brachioulnar artery has only been described twice before in the literature. The existence of such a variant is of particular clinical significance, as these arteries are more susceptible to trauma, and can be easily confused with superficial veins during medical and surgical procedures, potentially leading to iatrogenic distal limb ischemia.
- A Rare Variation of the Extensor Indicis Proprius Tendon With Important Clinical ImplicationsPublication . Casal, D; Pais, D; Bilhim, T; Ribeiro, V; Cunha, S; Damásio, C; Fernandes, R; Almeida, MA; Goyri-O'Neill, JIntroduction: Anatomical variations of the extensor tendons to the fingers are of great clinical interest, due to the relatively high frequency of tendon injury in clinical practice. Material and methods: During routine dissection of the right upper limb of a 67-year-old female preserved corpse, the extensor indicis proprius (EIP) muscle belly originated 3 independent tendons, each with a separate fascial sheath, forming a triple EIP tendon. There was a larger tendon, which occupied a central position, that represented the usual single EIP tendon. In addition, there were two thinner radial and ulnar accessory EIP tendons. The radial-EIP tendon crossed deep to the extensor digitorum communis (EDC) tendon to the index finger in the distal half of the dorsum of the hand to reach the radial side of the extensor expansion hood of the index finger. Discussion: According to the literature, the frequency of a triple EIP tendon ranges from 0%, to as high as 7%, although most authors do not acknowledge the presence of this variant in their series. This variant of the EIP tendon, in which the radial-EIP terminated laterally to the termination of the tendon of the EDC to the index finger, may be a source of confusion intraoperatively, as the EIP tendon has traditionally been identified on the basis of its ulnar location with respect to the EDC tendon. Conclusion: The possibility of a triple EIP tendon should certainly be born in mind by all surgeons when performing tendon repairs, tenoplasties or tendon transfers.