Review of Piezoelectrical Materials Potentially Useful for Peripheral Nerve Repair.

It has increasingly been recognized that electrical currents play a pivotal role in cell migration and tissue repair, in a process named "galvanotaxis". In this review, we summarize the current evidence supporting the potential benefits of electric stimulation (ES) in the physiology of peripheral nerve repair (PNR). Moreover, we discuss the potential of piezoelectric materials in this context. The use of these materials has deserved great attention, as the movement of the body or of the external environment can be used to power internally the electrical properties of devices used for providing ES or acting as sensory receptors in artificial skin (e-skin). The fact that organic materials sustain spontaneous degradation inside the body means their piezoelectric effect is limited in duration. In the case of PNR, this is not necessarily problematic, as ES is only required during the regeneration period. Arguably, piezoelectric materials have the potential to revolutionize PNR with new biomedical devices that range from scaffolds and nerve-guiding conduits to sensory or efferent components of e-skin. However, much remains to be learned regarding piezoelectric materials, their use in manufacturing of biomedical devices, and their sterilization process, to fine-tune their safe, effective, and predictable in vivo application.

Molecular Changes In Cardiac Tissue As A New Marker To Predict Cardiac Dysfunction Induced By Radiotherapy.

The contribution of radiotherapy, per se, to late cardiotoxicity remains controversial. To clarify its impact on the development of early cardiac dysfunction, we developed an experimental model in which the hearts of rats were exposed, in a fractionated plan, to clinically relevant doses of ionizing radiation for oncological patients that undergo thoracic radiotherapy. Rat hearts were exposed to daily doses of 0.04, 0.3, and 1.2 Gy for 23 days, achieving cumulative doses of 0.92, 6.9, and 27.6 Gy, respectively. We demonstrate that myocardial deformation, assessed by global longitudinal strain, was impaired (a relative percentage reduction of >15% from baseline) in a dose-dependent manner at 18 months. Moreover, by scanning electron microscopy, the microvascular density in the cardiac apex was significantly decreased exclusively at 27.6 Gy dosage. Before GLS impairment detection, several tools (qRT-PCR, mass spectrometry, and western blot) were used to assess molecular changes in the cardiac tissue. The number/expression of several genes, proteins, and KEGG pathways, related to inflammation, fibrosis, and cardiac muscle contraction, were differently expressed in the cardiac tissue according to the cumulative dose. Subclinical cardiac dysfunction occurs in a dose-dependent manner as detected by molecular changes in cardiac tissue, a predictor of the severity of global longitudinal strain impairment. Moreover, there was no dose threshold below which no myocardial deformation impairment was detected. Our findings i) contribute to developing new markers and exploring non-invasive magnetic resonance imaging to assess cardiac tissue changes as an early predictor of cardiac dysfunction; ii) should raise red flags, since there is no dose threshold below which no myocardial deformation impairment was detected and should be considered in radiation-based imaging and -guided therapeutic cardiac procedures; and iii) highlights the need for personalized clinical approaches.

Analysis of human tissues using Energy Dispersive X Ray Fluorescence - Dark matrix determination for the application to cancer research.

BACKGROUND: X ray Fluorescence has been essayed as a suitable technique for the elemental quantification of trace element in human tissues, namely comparison of normal and cancerous tissue. However, accurate results depend on a robust quantification approach, namely correct evaluation of the samples' dark matrix. METHODS: In order to determine the most suitable dark matrix composition for the quantification of such samples using the Fundamental Parameter approach, we have measured several Certified Reference Materials and essayed different dark matrix compositions to achieve the most accurate results. The resulting dark matrix was then applied to normal and tumor ovarian and prostate tissue samples, and the obtained results were compared with the ones obtained with a comparative method using external standard calibration curves. RESULTS: Using a dark matrix composed of 10 % - H, 22 % - C, 3 % - N and 60 % - O yielded the best compromise in accuracy for the light and heavy elements. For the reduced sample size and conditions of this study, for both organs, the concentrations of transition metals decrease in tumor tissues, while the concentration of lighter elements, P and Cl, increases. On the other hand, there are elements that showed different behavior between the two types of tissue, namely Zn and S, that increase in prostate tumor tissue and decrease in ovarian tissue. CONCLUSION: An increase in precision was one of the improvements found with the newly developed method, as the FP-approach contemplates matrix effects and the influence of other elements in the analytes' quantification. Additionally, the determined dark matrix can be employed in any tissue analysis application by means of EDXRF.

Cancer During Pregnancy: How to Handle the Bioethical Dilemmas?-A Scoping Review With Paradigmatic Cases-Based Analysis.

Ethical issues that arise during the care of a pregnant woman with cancer are challenging to physicians, policymakers, lawyers, and the bioethics community. The main purpose of this scoping review is to summarize existing literature regarding the bioethical dilemmas when a conflict arises in the maternal-fetus dyad, like the one related to cancer and pregnancy outcomes. Moreover, we illustrate the decision-making process of real-life case reports. Published data were searched through the PubMed and Google Scholar databases, as well as in grey literature, using appropriate controlled keywords in English and Portuguese. After identification, screening, eligibility and data extraction from the articles, a total of 50 was selected. There are several established ethical frameworks for conflict resolution and decision-making. Pragmatic theoretical approaches include case-based analysis, the ethics of care, feminist theory, and traditional ethical principlism that scrutinizes the framework of autonomy, justice, beneficence, and non-maleficence. In addition, society and practitioner values could mediate this complex ethical interplay. The physician must balance autonomy and beneficence-based obligations to the pregnant woman with cancer, along with beneficence-based obligations to the fetus. Ethical challenges have received less attention in the literature, particularly before the third trimester of pregnancy. Best, unbiased and balanced information must be granted both to the patient and to the family, regarding the benefits and harms for the woman herself as well as for the fetal outcome. Based on a previously validated method for analyzing and working up clinical ethical problems, we suggest an adaptation of an algorithm for biomedical decision-making in cancer during pregnancy, including recommendations that can facilitate counseling and help reduce the suffering of the patient and her family.

Unconventional Perfusion Flaps in the Experimental Setting: A Systematic Review and Meta-Analysis.

BACKGROUND: Unconventional perfusion flaps offer multiple potential advantages compared with traditional flaps. Although there are numerous experimental articles on unconventional perfusion flaps, the multiple animal species involved, the myriad vascular constructions used, and the frequently conflicting data reported make synthesis of this information challenging. The main aim of this study was to perform a systematic review and meta-analysis of the literature on the experimental use of unconventional perfusion flaps, to identify the best experimental models proposed and to estimate their global survival rate. METHODS: The authors performed a systematic review and meta-analysis of all articles written in English, French, Italian, Spanish, and Portuguese on the experimental use of unconventional perfusion flaps and indexed to PubMed from 1981 until February 1, 2017. RESULTS: A total of 68 studies were found, corresponding to 86 optimized experimental models and 1073 unconventional perfusion flaps. The overall unconventional perfusion flap survival rate was 90.8 percent (95 percent CI, 86.9 to 93.6 percent; p < 0.001). The estimated proportion of experimental unconventional perfusion flaps presenting complete survival or nearly complete survival was 74.4 percent (95 percent CI, 62.1 to 83.7 percent; p < 0.001). The most commonly reported animal species in the literature were the rabbit (57.1 percent), the rat (26.4 percent), and the dog (14.3 percent). No significant differences were found in survival rates among these species, or among the diverse vascular patterns used. CONCLUSION: These data do not differ significantly from those reported regarding the use of unconventional perfusion flaps in human medicine, suggesting that rabbit, rat, and canine experimental unconventional perfusion flap models may adequately mimic the clinical application of unconventional perfusion flaps.

Pars tensa and tympanicomalleal joint: proposal for a new anatomic classification.

PURPOSE: The tympanic membrane (TM) belongs to the ear. Despite its place in the ear anatomy, can we give it also a different anatomic classification? The main objective is to clarify the nature of TM, tympanic bone and malleus to propose a new anatomic classification. METHODS: This cadaveric study was performed in two human heads and six fresh temporal bones. A study of the temporomandibular joint, external acoustic meatus (EAM), TM and middle ear structures was conducted. A medical literature review englobing anatomy, embryology, histology and phylogeny of the ear was performed and the results were compared with the results of the dissection. RESULTS: The external ear is constituted by the auricle and the EAM. This last segment is made by a cartilaginous and an osseous portion. The osseous portion of the EAM is constituted mainly by tympanic bone. The external ear is separated from the middle ear by the TM. Inside the middle ear, there are three ossicles: malleus, incus and stapes, which allow the conduction of sound to the cochlea. Based on the anatomic dissection and medical literature review of the tympanic bone, malleus and TM, we propose that these structures are interconnected like a joint, and named it "Tympanicomalleal joint". CONCLUSIONS: It seems that the TM can be part of a joint that evolved to improve sound transmission and middle ear protection. Thinking TM has part of a joint may help in the development of more efficient reconstructive surgical techniques.

Reconstruction of a long defect of the ulnar artery and nerve with an arterialized neurovenous free flap in a teenager: A case report and literature review.

There is evidence that nerve flaps are superior to nerve grafts for bridging long nerve defects. Moreover, arterialized neurovenous flaps (ANVFs) have multiple potential advantages over traditional nerve flaps in this context. This paper describes a case of reconstruction of a long defect of the ulnar artery and nerve with an arterialized neurovenous free flap and presents a literature review on this subject. A 16-year-old boy sustained a stab wound injury to the medial aspect of the distal third of his right forearm. The patient was initially observed and treated at another institution where the patient was diagnosed with a flexor carpis ulnaris muscle and an ulnar artery section. The artery was ligated and the muscle was sutured. Four months later, the patient was referred to our institution with complaints of ulnar nerve damage, as well as hand pain and cold intolerance. Physical examination and ancillary tests supported the diagnosis of ulnar artery and nerve complete section. Surgery revealed an 8 cm hiatus of the ulnar artery and a 5 cm defect of the ulnar nerve. These gaps were bridged with a flow through ANVF containing the sural nerve and the lesser saphenous vein. The postoperative course was uneventful. Two years postoperatively, the patient had regained normal trophism and M5 strength in all previously paralyzed muscles according to the Medical Research Council Scale. Thermography revealed good perfusion in the right ulnar angiosome. The ANVF may be an expedite, safe and efficient option to reconstruct a long ulnar nerve and artery defect.

Blood Supply to the Integument of the Abdomen of the Rat: A Surgical Perspective.

BACKGROUND: 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.

Optimization of an Arterialized Venous Fasciocutaneous Flap in the Abdomen of the Rat.

BACKGROUND: 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.

A stab wound to the axilla illustrating the importance of brachial plexus anatomy in an emergency context: a case report.

BACKGROUND: Although open injuries involving the brachial plexus are relatively uncommon, they can lead to permanent disability and even be life threatening if accompanied by vascular damage. We present a case report of a brachial plexus injury in which the urgency of the situation precluded the use of any ancillary diagnostic examinations and forced a rapid clinical assessment. CASE PRESENTATION: We report a case of a Portuguese man who had a stabbing injury at the base of his left axilla. On observation in our emergency room an acute venous type of bleeding was present at the wound site and, as a result of refractory hypotension after initial management with fluids administered intravenously, he was immediately carried to our operating room. During the course of transportation, we observed that he presented hypoesthesia of the medial aspect of his arm and forearm, as well as of the ulnar side of his hand and of the palmar aspect of the last three digits and of the dorsal aspect of the last two digits. Moreover, he was not able to actively flex the joints of his middle, ring, and small fingers or to adduct or abduct all fingers. Exclusively relying on our anatomical knowledge of the axillary region, the site of the stabbing wound, and the physical neurologic examination, we were able to unequivocally pinpoint the place of the injury between the anterior division of the lower trunk of his brachial plexus and the proximal portion of the following nerves: ulnar, medial cutaneous of his arm and forearm, and the medial aspect of his median nerve. Surgery revealed a longitudinal laceration of the posterior aspect of his axillary vein, and confirmed a complete section of his ulnar nerve, his medial brachial and antebrachial cutaneous nerves, and an incomplete section of the ulnar aspect of his median nerve. All structures were repaired microsurgically. Three years after the surgery he showed a good functional outcome. CONCLUSIONS: We believe that this case report illustrates the relevance of a sound anatomical knowledge of the brachial plexus in an emergency setting.

A Model of Free Tissue Transfer: The Rat Epigastric Free Flap.

Free 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.

Systematic Review and Meta-Analysis of Unconventional Perfusion Flaps in Clinical Practice.

BACKGROUND: Although unconventional perfusion flaps have been in clinical use since 1975, many surgeons are still deterred from using them, because of some reports of high necrosis rates. METHODS: The authors performed a systematic review and meta-analysis of all articles written in English, French, German, Spanish, and Portuguese on the clinical use of unconventional perfusion flaps and indexed to PubMed from 1975 until July 15, 2015. RESULTS: A total of 134 studies and 1445 patients were analyzed. The estimated survival rate of unconventional perfusion flaps was 89.5 percent (95 percent CI, 87.3 to 91.3 percent; p < 0.001). Ninety-two percent of unconventional perfusion flaps (95 percent CI, 89.9 to 93.7 percent; p < 0.001) presented complete or nearly complete survival. Most defects mandating unconventional perfusion flap reconstruction were caused by trauma (63.6 percent), especially of the hand and fingers (75.1 percent). The main complication of all types of flaps was a variable degree of necrosis (7.5 percent of all unconventional perfusion flaps presented marginal necrosis; 9.2 percent and 5.5 percent had significant and complete necrosis, respectively). There was a positive correlation between the rate of postoperative infection and the need for a new flap (Pearson coefficient, 0.405; p = 0.001). Flaps used to reconstruct the upper limb showed better survival than those transferred to the head and neck or to the lower limb (p < 0.001). CONCLUSION: Unconventional perfusion flaps show high survival rates and should probably be used more liberally, particularly in the realm of upper limb reconstruction. CLINICAL QUESTION/LEVEL OF EVIDENCE: Therapeutic, V.

[Informed Treatment Consent and Refusal in Advanced Endonasal Surgery: The Ethical Dilemma of Olfaction Sacrifice in Surgery for Chronic Rhinosinusitis with Polyposis]. / O Consentimento e a Recusa Esclarecidos na Cirurgia Endonasal Avançada: O Dilema Ãtico do Sacrifício do Olfacto na Cirurgia da Rino-Sinusite Crónica com Pólipos.

INTRODUCTION: Olfaction is frequently affected in chronic rhino-sinusitis with polyposis and has been recognised to have important impact on quality of life. Surgical resolution on cases of maximal medical therapy failure is an option to relieve symptoms, with debates as to how extensive surgery should be. A more radical approach will achieve better disease control with less relapse, but can also compromise olfaction. This decision about a more radical surgical approach should be shared with the patient. Thorough informed consent regarding disease control and hyposmia should be taken. MATERIAL AND METHODS: Literature review and consultation with a board of experts. RESULTS AND DISCUSSION: We propose some elements to be included in the informed consent discussion, in order to broadly address the surgical limitations regarding anosmia as a frequent complaint, as well as the different options and their associated consequences. CONCLUSION: Radical surgery decision making should be shared with the patient and the informed consent should be as thorough as possible regarding disease control and hyposmia resolution.

Introdução: Na rino-sinusite crónica com pólipos, ou polipose naso-sinusal, o olfacto está frequentemente afectado de forma significativa, e é reconhecido o impacto importante deste sintoma na qualidade vida. A resolução por cirurgia endonasal nos casos de resistência à terapêutica médica máxima é uma opção para minorar os sintomas, mas a sua extensão é alvo de controvérsia, sendo que uma cirurgia mais radical, como a nasalização, controla melhor a doença com menos recidivas, mas pode comprometer mais o olfacto. A decisão da extensão da cirurgia deve ser partilhada com o doente, devendo o esclarecimento informado ser tão completo quanto possível quanto às expectativas de controlo da doença como à resolução da hipósmia. Material e Métodos: Revisão bibliográfica e discussão por quadro de peritos. Resultados e Discussão: Baseando-nos em revisão de literatura, apresentamos uma proposta de elementos a incluir no esclarecimento cirúrgico, de modo a contemplar de forma abrangente as limitações da cirurgia no que diz respeito ao sintoma anósmia, bem como das diferentes opções e suas consequências quanto à sua radicalidade, focando a atenção no ponto de vista da ética médica. Conclusão: A decisão da extensão da cirurgia deve ser partilhada com o doente, devendo o esclarecimento informado ser tão completo quanto possível quanto às expectativas de controlo da doença como à resolução da hipósmia.

Sciatic nerve high division: two different anatomical variants.

INTRODUCTION: Sciatic nerve variations are relatively common. These variations are often very significant in several fields of Medicine. The purpose of this paper is to present two such variants and discuss their clinical implications. MATERIAL AND METHODS: Three Caucasian cadavers with no prior history of lower limb trauma or surgery were dissected and found to present anatomical variants of the sciatic nerve. RESULTS: In all cases the sciatic nerve divided above the popliteal fossa. In two cases (cadavers 1 and 2) it divided on both sides in the inferior portion of the gluteal region in its two terminal branches: the common fibular and the tibial nerves. In another case (cadaver 3) the sciatic nerve was found to divide inside the pelvis just before coursing the greater sciatic notch. The common fibular nerve exited the pelvis above the pyriformis muscle and then passed along its posterior aspect, while the tibial nerve coursed deep to the pyriformis muscle. DISCUSSION: According to the literature, the anatomical variant described in cadaver 3 is considered relatively rare. This variant can predispose to nerve entrapment and thus to the pyriformis syndrome, sciatica and coccygodynia. The high division of the sciatic nerve, as presented in cadavers 1 and 2, can make popliteal nerve blocks partially ineffective. CONCLUSION: The anatomical variants associated with a high division of the sciatic nerve, must always be born in mind, as they are relatively prevalent, and have important clinical implications, namely in Anesthesiology, Neurology, Sports Medicine and Surgery.

Introdução: As variações do nervo isquiático são relativamente comuns e frequentemente muito significativas clinicamente. O objetivo deste trabalho é apresentar duas destas variações e discutir algumas das suas implicações clínicas.Material e Métodos: Três cadáveres caucasianos sem história prévia de trauma ou cirurgia no membro inferior foram dissecados, apresentando variações anatómicas do nervo isquiático.Resultados: Em todos os casos o nervo isquiático dividia-se acima da fossa poplítea.Em dois casos (cadáveres1 e 2) a terminação deste nervo ocorria na porção inferior da região glútea nos seus dois ramos terminais: os nervos fibular comum e tibial. Num outro caso (cadáver 3), o nervo isquiático dividia-se ainda dentro da bacia antes de percorrer a incisura isquiática maior. Neste caso, o nervo fibular comum saía da pelve acima do músculo piriforme, passando em seguida ao longo de sua face posterior, enquanto que o nervo tibial corria profundamente ao músculo piriforme.Discussão: De acordo com a literatura, a variante anatómica descrita no cadáver 3 é considerada relativamente rara. Esta variante poderá predispor a síndromes compressivos do nervo isquiático. A divisão alta do nervo isquiático, de que são exemplos os cadáveres 1 e 2, pode comprometer a eficácia dos bloqueios anestésicos ao nível da fossa poplítea.Conclusão: As variantes anatómicas associadas à divisão alta do nervo isquiático devem sempre ser tidas em consideração porserem relativamente comuns e terem importantes implicações clínicas, nomeadamente nas áreas de Anestesiologia, Neurologia, Medicina do Desporto e Cirurgia.

Paresthesia and hypesthesia in the dorsum of the foot as the presenting complaints of a ganglion cyst of the foot.

Although ganglion cysts of the foot represent a substantial amount of lumps in this region, they rarely cause peripheral nerve symptoms. We describe the clinical case of a 43-year-old female with complaints in the previous three months of hypesthesia and paresthesia in the anterior portion of the medial half of the dorsum of her left foot that extended into the first interdigital cleft. She associated the start of her neurological symptoms to the appearance of a lump in the dorsum of the foot. A presumptive diagnosis of compression of the medial branch of the deep fibular nerve and of the medial dorsal cutaneous nerve in the dorsum of the foot by a ganglion cyst was made. Ultrasonography confirmed the cystic nature of the lesion and surgery allowed complete excision of a mass arising from the joint between the medial and intermediate cuneiform bones that was compressing the deep fibular nerve and the medial dorsal cutaneous nerve. Pathological examination confirmed that the lesion was a cystic ganglion. As far as the authors know, the simultaneous compression of the medial branch of the deep fibular nerve and of the medial dorsal cutaneous nerve in the dorsum of the foot by a ganglion cyst has not been described before.