Relation between opfthalmic ultrasound biometry and the morphometric parameters of the skull, age, weight and gender in domestic cats

Ocular ultrasonography is a helpful ophthalmic examination, performed on the absence of transparency in ocular means and frequently requested prior intraocular surgery. Unfortunately, the lack of studies upon ultrasonografic images of the normal feline eye, difficults the evaluation of its biometry and its inner structures in many ophthalmic diseases and also before surgery. The objective of this study was to evaluate the ocular biometry and the morphometric parameters of the cranium of 40 healthy adult cats, including 22 Persian cats (Brachycephalic group - BG) and 18 Mixed-breed cats (Noun brachycephalic group - NBG). B/A-mode ultrasonographic biometry, utilizing a 9 MHz probe, was performed for depth of the anterior chamber (D1), lens axial length (D2), depth of the vitreous chamber (D3) and axial length of the globe (D4). Morphometric parameters of the cranium were obtained for bizygomatic (BZ) and occipital frontal (OF) diameters. Data was collected and statistical analysis, including t paired tests, variance and covariance analysis and multiple linear regressions was performed for every obtained measure and also for animal ages, weigh and gender. Statistic relevant values were observed in D4 parameter for female cats of BG. Multiple linear regression indicated some influence of the weigh, age and OF in D1, D2 and D4 of PG; and of BZ in D1, D3 and D4 of NBG. Besides that, it was observed that biometry was also influenced by weigh, age and morphometric parameters of their craniums in both groups.O exame ultrassonográfico ocular é indispensável no pré-operatório de procedimentos cirúrgicos intraoculares como a facectomia, além de ser uma ferramenta complementar ao exame oftalmológico, em casos de perda da transparência dos meios ópticos. A inexistência de estudos acerca de padrões de normalidades para as medidas do bulbo ocular e de suas estruturas internas nos gatos, cujos valores possibilitam o monitoramento de enfermidades e auxiliam em procedimentos cirúrgicos motivaram este estudo. Utilizaram-se 40 gatos, adultos, machos e fêmeas, livres de enfermidades sistêmica e oftalmológica. Destes, 22 eram da raça persa (grupo braquicefálico - GB) e 18 sem raça definida (grupo não braquicefálico - GNB). A biometria ultrassonográfica ocular transcorneana foi realizada, em modo-B∕A, com o transdutor microlinear de 9 MHz e as medidas D1 (profundidade da câmara anterior), D2 (diâmetro do cristalino), D3 (profundidade da câmara vítrea) e D4 (diâmetro axial do bulbo ocular) aferidas. Ainda, mensuraram-se as distâncias fronto-occipital e bizigomática e o peso desses animais. Os dados obtidos foram analisados pelo teste-t pareado, seguindo-se as análises de variância e covariância, além da regressão linear múltipla relacionando-se as medidas de D1, D2, D3 e D4 às medidas bizigomática e fronto-occipital, como também à idade, ao peso e ao gênero. Obteve-se como resultado a média de D1, D2, D3 e D4, assim como dos diâmetros bizigomático e fronto-occipital, idade e peso, verificando-se diferenças significativas para D4 nas fêmeas de GB. Houve, pela análise de regressão linear, influência do peso, idade e diâmetro fronto-occipital sobre D1, D2 e D4 nos gatos do GB, e dos diâmetros bizigomático sobre D1, D3 e D4 nos gatos do GNB. Conclui-se que houve diferença no diâmetro axial do bulbo ocular nas fêmeas do GB, e que o peso, a idade e os diâmetros cranianos influenciam a biometria ocular dos gatos braquicefálicos e não braquicefálicos.Faculdade de Ciências Sociais e Agrárias de ItapevaUniversidade Federal de São Paulo (UNIFESP) Escola Paulista de Medicina Departamento de OftalmologiaUniversidade de FrancaUNIFESP, EPM, Depto. de OftalmologiaSciEL

Isometry of Potential Attachment Sites for the Iliotrochanteric Suture in Dogs: an ex vivo Study

Background: Coxofemoral luxation is the most common traumatic luxation in dogs and the iliotrochanteric suture is one of the surgical treatment options. The orthopedic suture aimed at surgically restoring joint movement should be employed in an isometric manner in order to maintain adequate tension throughout the arc of motion. This study aimed to determine the isometric points for the iliotrochanteric suture in dogs during the joint extension and flexion movements. This evaluation was performed both in the intact hip joint and in the luxation model, establishing the best combination, among the determined points, for the reestablishment of normal joint movement.Materials, Methods & Results: Radiographic analyses of 12 canine cadaveric hips, both intact and in craniodorsal luxation model, were performed in a neutral position, flexion at 50°, and extension at 150°. In the trochanteric segment, two parallel lines were drawn, creating the central vertical axis and the secondary vertical axis. Three points were then determined on each axis, from proximal to distal, corresponding to 25, 50, and 75% of the height of the axis, and were labelled as T1, T2, and T3 and T4, T5, and T6, respectively. In the iliac segment, a line perpendicular to the longitudinal axis of the ilium was drawn, and 25, 50, and 75% of this height corresponded to points I1, I2, and I3, respectively. The lengths between the points were measured, with the objective of evaluating which combination of points presented less variation in the joint positions. The central location of the iliac and trochanteric segments, determined respectively by I2 and T2, provided smaller variations during the maximal movements of hip flexion and extension.Discussion: The surgical techniques of iliotrochanteric suture target to maintain the internal rotation of the femoral head inside the acetabulum and abduction of the femur until the soft tissues have healed. The described techniques for the iliotrochanteric suture present a great anatomical variety in the arrangement of the anchor points of the suture. It is known that if during motion, the attachment sites move closer to one another, the suture will become lax and, if the attachment sites move away from one another, the suture will tighten. Therefore, the implantation in isometric sites assists in reducing the variation of the distance between the points of origin and insertion of the suture during joint movement, keeping the suture tension constant and allowing the functional recovery of the joint. This study demonstrates that there are some locations for the origin and insertion of an iliotrochanteric suture that are associated with less length change than others. I2-T2 combination is the point closest to isometry for the iliotrochanteric suture during hip extension and flexion, so that, T2 is the most central point of the greater trochanter, corresponding to 50% of the height of its central vertical axis, as well as I2, which corresponds to the most central point of the ilium, representing 50% of the height of the most caudal portion of its body. The isometric point found by us details the exact location of perforation in all aspects (height and length), both in the ilium and the trochanter. In addition, it is a personalized point created for each patient from its radiographic examination and taking into consideration its anatomical variations, so that there is no damage to the suture during hip extension and flexion movements

Biomechanical evaluation of four surgical techniques for ventral stabilization of the atlantoaxial joint in dogs

ABSTRACT Purpose: This study compared, through biomechanical evaluation under ventral flexion load, four surgical techniques for ventral stabilization of the atlantoaxial joint in dogs. Methods: In total, 28 identical atlantoaxial joint models were created by digital printing from computed tomography images of a dog, and the specimens were divided into four groups of seven. In each group, a different technique for ventral stabilization of the atlantoaxial joint was performed: transarticular lag screws, polyaxial screws, multiple screws and bone cement (polymethylmethacrylate–PMMA), and atlantoaxial plate. After the stabilization technique, biomechanical evaluation was performed under ventral flexion load, both with a predefined constant load and with a gradually increasing load until stabilization failure. Results: All specimens, regardless of stabilization technique, were able to support the predefined load without failing. However, the PMMA method provided significant more rigidity (p ≤ 0.05) and also best resisted the gradual increase in load, supporting a significantly higher maximum force (p ≤ 0.05). There was no statistical difference in flexural strength between the transarticular lag screws and plate groups. The polyaxial screws method was significantly less resistant to loading (p ≤ 0.05) than the other groups. Conclusions: The PMMA technique had biomechanical advantages in ventral atlantoaxial stabilization over the other evaluated methods

Bilateral Double-Pigtail Ureteral Stent Placement for Management of Ureteral Obstruction Secondary to Transitional Cell Carcinoma in a Dog

Background: Transitional cell carcinoma (TCC) usually affects the trigone region of the bladder and proximal portion of the urethra. TCC in dogs is often complicated by local tumor invasion and obstruction of the urethra, ureters, or both. Urinary obstruction is the cause of death in approximately 60% of dogs with TCC. Radical surgeries are associated with morbidity and mortality rates. Stents have recently been evaluated for use in dogs with ureteral obstruction resulting from a variety of urinary tract tumors. This report aims to describe bilateral ureteral stent placement for treatment of malignant ureteral obstruction and long-term follow-up in a dog.Case: An 11‐year‐old female spayed Maltese with ureteral obstruction secondary to transitional cell carcinoma (TCC) in the bladder trigone. After palliative debulking procedure and diagnostic of TCC in bladder and NSAIDs treatment, recurrence has occurred causing ureteral obstruction and TCC had invaded the abdominal wall. Abdominal wall local tumor resection, trigone mass debulking and bilateral ureteral stent placement was made. A double-pigtail ureteral stent of appropriate length was advanced to bypass the ureteral obstruction. Stent sizes were 3.5 Fr in diameter and from 8 to 32 cm in length. The patient underwent surgical resection of the transitional cell carcinoma in the abdominal wall. The correct location of the bilateral ureteral pigtail stent was certified by abdominal radiography. Recovery was uneventful and the dog was discharged 2 days after surgery. Eleven months after stent placement, the dog developed lumbar vertebrae metastasis, without evidence of recurrent ureteral obstruction. The owners elected euthanasia 517 days after original presentation and 337 days after ureteral stent placement. Euthanasia was unrelated to the local tumor obstruction but was related to the bone metastasis.Discussion: Ureteral stent placement is feasible techniques for treatment of bladder TCC in dogs, with the objective of delaying the evolution of the disease and preventing ureteral obstruction. According to previous studies, although distant metastatic disease is worrisome, in the majority of dogs with bladder TCC, the primary location of the tumor is the most common cause of death. In patients with ureteral obstruction, early intervention preserves functional renal tissue. Thus, relief of obstruction should be recommended as soon as possible before irreversible renal damage occurs. The authors encourage aggressive and timely intervention, particularly when ureteral obstruction is bilateral. In the present report, 90 days postoperatively local recurrence causing ureteral obstruction was not evidenced on bladder ultrasound images and laboratory test follow-up. After this period, until 180 days after debulking surgery, tumor recurrence occurred, causing clinical signs and compromising renal function. Complications associated with stent placement included stent migration, recurrent ureteral obstruction, stranguria/pollakiuria, presumably due to irritation of the trigonal region from the distal stent; imperfect stent location; ureteral trauma during stent placement; and urinary tract infection. In the present report, the ureteral stents were placed for palliative treatment for malignant ureteral obstructions. Although urinary tract infection was recurrent, other complications associated with bilateral ureteral stent did not occur, such as accidental dislocation or stent obstruction by the tumor. The results obtained were satisfactory for urinary tract obstruction, allowing survival of 517 days. These findings may support long-term ureteral stenting in veterinary patients

Two levels of the inspired oxygen fraction in propofol-anesthetized dogs with high intracranial pressure: cardiopulmonary function

In the initial stage of traumatic brain injury, the use of 1.0 inspired oxygen fraction (FiO2) is indicated. However, high FiO2 has been correlated with atelectasis. Thus, the effects of FiO2 = 1.0 and FiO2 = 0.6 on the cardiopulmonary function in propofol-anesthetized dogs with high intracranial pressure (ICP) were evaluated. Eight dogs were anesthetized on two occasions, receiving, during controlled ventilation, an FiO2 = 1 (G100) or an FiO2 = 0.6 (G60). Propofol was used for induction (10mg.kg-1) followed by a continuous rate infusion (0.6mg.kg-1.minute-1). An increase in the ICP was induced by temporary obliteration of the right jugular vein (OJv) 50 minutes after induction of anesthesia. The measurement was taken twenty minutes after OJv (T0) and then at 15-minute intervals (T15 to T60). Alveolar oxygen partial pressure in G60 was lower than in G100 during the whole procedure. Alveolar-arterial oxygen gradient in G100 was greater than in G60 at T0 and at T60. No differences were observed for arterial oxygen partial pressure/inspired oxygen fraction ratio, arterial-to-alveolar oxygen pressure ratio, respiratory index, venous admixture, oxygen delivery, oxygen consumption, oxygen extraction, heart rate, mean pulmonary arterial pressure, pulmonary arterial occlusion pressure, cardiac index, stroke index and systemic vascular resistance index. In G100, mean arterial pressure at T0 was higher than at T45. In dogs with high ICP, the cardiopulmonary function was not influenced by the different FiO2 used.No estágio inicial do trauma encefálico, o emprego de fração inspirada de oxigênio (FiO2) de 1,0 é indicado. Todavia, altas FiO2 têm sido correlacionadas com atelectasia. Assim, avaliaram-se os efeitos das FiO2 = 1.0 e FiO2 = 0.6 sobre a função cardiopulmonar em cães com pressão intracraniana (PIC) elevada e anestesiados com propofol. Oito animais foram anestesiados em duas ocasiões e receberam, durante a ventilação controlada, FiO2 = 1(G100) ou FiO2 = 0,6 (G60). Propofol foi usado para indução (10mg.kg-1) e seguido por infusão contínua (0,6mg.kg-1minuto-1). O aumento da PIC foi induzido pela obliteração temporária da veia jugular (OJv). As mensurações foram realizadas 20 minutos após OJv (T0) e em intervalos de 15 minutos (de T15 a T60). A pressão parcial de oxigênio alveolar no G60 foi menor do que no G100 durante todo o procedimento. O gradiente alveolar-arterial no G100 foi maior do que no G60, em T0 e T60. Não foram observadas diferenças para: relação pressão parcial de oxigênio/fração inspirada de oxigênio, relação arterioalveolar, índice respiratório, mistura arteriovenosa, oferta de oxigênio, consumo de oxigênio, taxa de extração de oxigênio, frequência cardíaca, pressão da artéria pulmonar média, pressão de oclusão da artéria pulmonar, índice cardíaco, índice sistólico e índice de resistência vascular sistêmica. No G100, a pressão arterial média em T0 foi maior do que em T45. Em cães com alta PIC, a função cardiopulmonar não foi influenciada pelas diferentes FiO2 empregadas.Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES

Evaluation of Operating Room Environment Contamination and Efficacy of 2% Chlorhexidine for Surgical Hand Scrubbing before and after Gowning and Gloving

Background: Human skin is colonized by various species of microorganisms, which makes them difficult to eliminate even with the use of antimicrobial drugs. Real efficacy of the antimicrobial product combined with incorrect administration of antibiotics, in addition to potential environmental contamination, are critical points for the establishment of postoperative infection or absence of it. The main objective of the present study was to evaluate the efficacy of surgical antisepsis using a 2% chlorhexidine brush during a surgery, detect operating room environmental contamination, and verify the existence of bacterial resistance to the antibiotics most commonly used in Veterinary Medicine.Materials, Methods & Results: In ten cases of the surgical routine, samples were collected concurrently at specific time points throughout 2 h of surgical procedure. To evaluate the efficacy of 2% chlorhexidine brush on hand scrubbing of a mock surgeon, swabs were used to sample the surface of the hands before and after gowning and gloving. Samples or their dilutions were inoculated onto blood agar and MacConkey agar plates. Contamination of the operating room was evaluated using BHI agar plates distributed through the room. After the incubation period, counts and biochemical tests were performed, and an antimicrobial disc susceptibility test was performed using antibiotics most commonly used in Veterinary Medicine.Discussion: Even though the surgical unit of the Veterinary Hospital “Governador Laudo Natel” is constantly sanitized, it is not free from microbial contamination. In the present study, there was no bacterial growth on MacConkey agar, which suggests absence of fecal contamination. Blood agar is a culture medium that provides optimal growth conditions to most pathogenic bacteria, which explains the higher microbial growth observed in this medium. Gram-positive cocci grew on blood agar forming grape bunch- and chain-like patterns, which indicates the possible presence of Staphylococcus sp. and Enterococcus sp. The results obtained to evaluate environmental contamination by means of BHI agar revealed growth of diverse microorganisms, with presence of Gram-positive cocci and Gram-negative rods. The biochemical tests indicated presence of microorganisms from various genera. About the evaluation of bacterial resistance to the antibiotics it was possible to observe high bacterial resistance to metronidazole, followed by ampicillin. Metronidazole has bactericidal activity against most of the anaerobic and facultative anaerobic bacteria, since the bacteria found were aerobic. As for ampicillin, it is considered a broad spectrum antibiotic, which indicates that the bacteria found can be resistant to this antibiotic. Clindamycin also resulted in bacterial high resistance, which shows that this drug was not effective against the Grampositive bacteria found in the samples studied. Enrofloxacin yielded high bacterial resistance indicating that wide use of this drug due to its intrinsic efficacy and safety might have contributed to the appearance of resistance. Results showed bacterial resistance to cephalexin, possibly indicating a lower efficacy in treatment against bacterial diseases, since a lot of the samples were Gram-positive. Bacterial resistance to ceftiofur was lower when compared to cephalexin; this can be related to the shorter time this drug has been in the market. The results revealed bacterial growth in the surgical environment, and verified the efficacy of 2% chlorhexidine for hand scrubbing. Spontaneous mutation and gene recombination contributes to the emergence of resistance is the indiscriminate use of antibiotics for the treatment of animals, which can contribute to bacterial resistance

Avaliação em longo prazo da técnica de avanço da tuberosidade tibial modificada em cães

The purpose of study was to assess long-term clinical and radiographic aspects of dogs’ stifle joints which had undergone a modified tibial tuberosity advancement technique (mTTA). A total of 15 stifles that had undergone mTTA for CCL disease of 11 patients were included in this study. Assessments involved patient’s gait analysis, cranial drawer and tibial compression tests, stifle goniometry range of articular motion, thigh and leg girth and radiographic evidence of progression of osteoarthrosis. Variables were compared between operated and healthy limbs and among moments (M0) on the early postop; (M1) 120 days postop; and (M2) approximately 5 years following surgery. A questionnaire regarding owner’s perceptions after approximately 5 years of surgery was assessed. Most dogs presented positive response to cranial drawer and tibial compression tests on operated knees. There was also decrease on goniometry and thigh girth and increase in leg girth. Radiographic evidence of progression of osteoarthritis was seen especially on the long-term follow-up (M2). On gait analysis, most animals presented some degree of lameness in different conditions, in contrast to owners’ perceptions. Osteoarthritis still develops in dogs following mTTA surgery for CCL disease. However, owners were overall satisfied with their recovery and would be willing to accept indication of mTTA for dogs with ruptured CCL.O objetivo deste estudo foi avaliar, em longo prazo, aspectos clínicos e radiográficos do joelho de cães submetidos à técnica modificada de avanço da tuberosidade da tíbia (mTTA). Um total de 15 joelhos de 11 pacientes foram submetidos à mTTA para correção de doença do ligamento cruzado cranial. A avaliação envolvia análise de marcha do paciente, teste de compressão tibial e de gaveta, goniometria do joelho para amplitude articular, circunferência das pernas e coxas e evidência radiográfica de progressão da osteoartrose. As variáveis foram comparadas entre membros operados e saudáveis e entre os momentos (M0) no pós-operatório imediato; (M1) 120 dias de pós-operatório; e (M2) aproximadamente cinco anos após a cirurgia. Foi avaliado um questionário sobre as percepções do proprietário após aproximadamente cinco anos de cirurgia. A maioria dos cães apresentou resposta positiva aos testes de gavetas e de compressão tibial em joelhos operados. Houve também diminuição na goniometria e na circunferência da coxa e aumento do perímetro das pernas. Evidências radiográficas de progressão da osteoartrite foram observadas especialmente no seguimento de longo prazo (M2). Na análise de marcha, a maioria dos animais apresentou algum grau de claudicação em diferentes condições, em contraste com as percepções dos proprietários. A osteoartrite ainda se desenvolve em cães após a cirurgia de mTTA para doença CCL. No entanto, os proprietários estavam, em geral, satisfeitos com a recuperação dos animais e estavam dispostos a aceitar a indicação de mTTA para cães com doença do ligamento cruzado cranial.TEIXEIRA, P. P. M. Universidade Federal Par

Eficácia de Diferentes Métodos de Proteção à Artéria Tibial Cranial, Fíbula, e Nervos Tibial e Fibular durante a TPLO: Estudo Comparativo Ex-vivo em cães

Background: Cranial cruciate ligament failure is one of the leading causes of pelvic limb lameness in dogs and one of the most recommended treatments is tibial plateau leveling osteotomy (TPLO) surgery. However, this procedure may lead to some complications as fractures of the fibula, laceration in varying degrees of the popliteal vasculature and its branches, neuropraxia, neurotmeses, among others. The goals of this study were to compare the effectiveness of 8 methods used during TPLO, to prevent damage to the cranial tibial artery, fibula, tibial and fibular nerve (surgical compresses, specific surgical retractors I and II and an osteotomy technique variation). Materials, Methods & Results: A total of 40 canine cadavers weighing 25.9 ± 3.7 kg were submitted to TPLO. Animals were previously prepared with 1: 4 barium red latex solution, to provide radiopacity of arteries surrounding the knee (n = 80). TPLO was performed using 8 methods to protect the cranial tibial artery, fibula, and tibial and fibular nerves. Each method was used in one of the knees of 5 animals. The contralateral knee was maintained as a control (without protection). The knees were radiographed in orthogonal projections before and after the osteotomies and then anatomically dissected. The evaluated structures were photographed, and the images sent to four blind evaluators (visual macroscopy) to classify the possible injuries. The highest incidence of injuries was identified when protection methods were used. However, this difference was not significant (P > 0.05). No significant differences regarding efficacy were found between all 8 protection methods. Discussion:  In this study, the total incidence of injuries following TPLO was 20% was much higher than that presented in the literature which indicates when considering only intraoperative injuries. The dogs cadavers tissue resistance and stiffened latex may have predisposed the osteotomy injury, as soft tissues with greater flexibility are less susceptible to trauma caused by the oscillatory saw. When compared to others cadaveric studies that also evaluated the efficacy of surgical dressings to protect the cranial tibial artery, during TPLO, we also find a higher incidence of damage. Maybe the limb’s position was responsible for this difference, once in the after mentioned researches the limb was positioned suspended to simulate a dorsal decubitus position and we choose the limb position with the lateral face resting on the surface of the operating table, and this may have provided extra pressure from the structures towards the osteotomy saw, increasing the occurrence of those damages. Although the present study did not reveal a significant difference for the use of protection methods, we believe that the dimensions of the compresses used herein may have contributed to a higher incidence of injuries. They probably increased the tissue trauma needed for their allocation and led to a lower positioning accuracy for the isolation of these structures.Maybe for the same reason, the specific type II surgical retractor was the only shield that, observationally, did not increase the occurrence of injuries, once less dissection was required to allocate it. The difference in geometric dimensions between the retractors may justify the superiority of the retractor II, since it allows a more careful and apparently less traumatic allocation. Performing TPLO without adopting these protection methods did not lead to a higher risk of injury to the cranial tibial artery, fibula, and tibial and fibular nerves. Keywords: osteotomy, vascular anatomy, canine stifle, TPLO.Revisão: A insuficiência do ligamento cruzado cranial é uma das principais causas de claudicação do membro pélvico em cães e a osteotomia do nivelamento do platô tibial (TPLO) um dos tratamentos mais recomendados. No entanto, este procedimento pode apresentar algumas complicações como fratura da fibula, lacerações em graus variados da vascularizaçaõ poplitea e suas ramificações, neuropraxias, neurotmeses, entre outras. Os onjetivos deste estudo foram comparar a eficácia de oito métodos de proteção utilizados durante a TPLO para prevenir danos à artéria tibial cranial, fíbula e nervos tibial e fibular (compressas cir[urgicas, afastadores cirúrgicos específicos e variação da técnica de osteotomia). Materiais, Métodos e Resultados: Quarenta cadáveres de cães pesando 25.9 ± 3.7 Kg foram submetidos à TPLO. OS animais foram previamnete preparados com solução 1:4 de látex baritado vermelho, de modo a garantir radiopacidade das artétias próximas do joelho (n=80). A TPLO foi executada utilizando oito métodos para proteção da artéria tibial cranial, fibula e nervos tibial e fibular. Cada método foi usado em apenas um dos joelhos de cinco animais. O joelho contralateral foi utilizado como controle (sem proteção). Os joelhos foram radiografados em projeções ortogonais antes e após a osteotomia e posteriormente dissecados anatomicamente. As estruturas avaliadas foram fotografadas e as imagens enviadas para quatro avaliadores cegos (macroscopia visual) para classificar possíveis injurias. A maior incidência de lesões foram observadas quando os métods de proteção foram utilizados. No entanto, esta diferença não se mostrou significativa (p>0,05). Quanto a eficácia de proteção entre os métodos, não houve diferença significativa. Discussão: Neste estudo, a incidência total de lesões após a TPLO foi de 20%, muito além da encontrada na literatura, quando consisera-se apenas as lesões transoperatorias. A resitência tecidual dos cadáveres e do latex endurecido pode ter predisposto ao dano na osteotomia, uma vez que tecidos moles possuem uma flexibilidade maior e são menos suceptiveis ao trauma causado pela serra oscilatória. Quando comparado a outros estudos cadavericos que também buscaram avaliar a eficácia de compressas cirúrgicas como método de proteção a artéria tibial cranial durante a TPLO, também encontramos uma incidência maior. Talvez, esta diferença, se deva pela posição do membro, uma vez que nos trabalhos mencionados, os pesquisadores mantiveram os membros numa posição suspensa, simulando o decubito dorsal e nós adotamos o membro com sua face lateral em contato com a mesa cirúrgica e, talvez isto, tenha gerado uma maior pressão nas estruturas contra a linha de osteotomia, aumentando a ocorrência dos danos. Apesar de o presente trabalho não mostrar diferença estatísitica significativa quanto ao uso dos métodos de proteção, acreditamos que a dimensão das compressas  utiizadas pode ter contribuidos para uma incidencia maior de lesão. Provavelmente elas aumentaram o trauma tecidual necessária para sua alocação e levaram a uma menor acurácia do posicionamento para proteção das estruturas. talvez pelo mesmo motivo, o afastador específico tipo II foi o único método que, de forma observacional, não aumentou o risco de lesão, uma vez que seu posicionamento exigia uma dissecação menor. A diferença da forma geometrica e dimensões dos afastadores pode justificar a superioridade do segundo, uma vez que permite um posicionamento mais preciso e menos traumático. Realizar a TPLO sem estes métodos de proteção não aumentaram o risco de lesão a artéria tibial cranial, fibula e nervos tibial e fibular

Eficácia de Diferentes Métodos de Proteção à Artéria Tibial Cranial, Fíbula, e Nervos Tibial e Fibular durante a TPLO: Estudo Comparativo Ex-vivo em cães

Background: Cranial cruciate ligament failure is one of the leading causes of pelvic limb lameness in dogs and one of the most recommended treatments is tibial plateau leveling osteotomy (TPLO) surgery. However, this procedure may lead to some complications as fractures of the fibula, laceration in varying degrees of the popliteal vasculature and its branches, neuropraxia, neurotmeses, among others. The goals of this study were to compare the effectiveness of 8 methods used during TPLO, to prevent damage to the cranial tibial artery, fibula, tibial and fibular nerve (surgical compresses, specific surgical retractors I and II and an osteotomy technique variation). Materials, Methods & Results: A total of 40 canine cadavers weighing 25.9 ± 3.7 kg were submitted to TPLO. Animals were previously prepared with 1: 4 barium red latex solution, to provide radiopacity of arteries surrounding the knee (n = 80). TPLO was performed using 8 methods to protect the cranial tibial artery, fibula, and tibial and fibular nerves. Each method was used in one of the knees of 5 animals. The contralateral knee was maintained as a control (without protection). The knees were radiographed in orthogonal projections before and after the osteotomies and then anatomically dissected. The evaluated structures were photographed, and the images sent to four blind evaluators (visual macroscopy) to classify the possible injuries. The highest incidence of injuries was identified when protection methods were used. However, this difference was not significant (P > 0.05). No significant differences regarding efficacy were found between all 8 protection methods. Discussion:  In this study, the total incidence of injuries following TPLO was 20% was much higher than that presented in the literature which indicates when considering only intraoperative injuries. The dogs cadavers tissue resistance and stiffened latex may have predisposed the osteotomy injury, as soft tissues with greater flexibility are less susceptible to trauma caused by the oscillatory saw. When compared to others cadaveric studies that also evaluated the efficacy of surgical dressings to protect the cranial tibial artery, during TPLO, we also find a higher incidence of damage. Maybe the limb’s position was responsible for this difference, once in the after mentioned researches the limb was positioned suspended to simulate a dorsal decubitus position and we choose the limb position with the lateral face resting on the surface of the operating table, and this may have provided extra pressure from the structures towards the osteotomy saw, increasing the occurrence of those damages. Although the present study did not reveal a significant difference for the use of protection methods, we believe that the dimensions of the compresses used herein may have contributed to a higher incidence of injuries. They probably increased the tissue trauma needed for their allocation and led to a lower positioning accuracy for the isolation of these structures.Maybe for the same reason, the specific type II surgical retractor was the only shield that, observationally, did not increase the occurrence of injuries, once less dissection was required to allocate it. The difference in geometric dimensions between the retractors may justify the superiority of the retractor II, since it allows a more careful and apparently less traumatic allocation. Performing TPLO without adopting these protection methods did not lead to a higher risk of injury to the cranial tibial artery, fibula, and tibial and fibular nerves. Keywords: osteotomy, vascular anatomy, canine stifle, TPLO.Revisão: A insuficiência do ligamento cruzado cranial é uma das principais causas de claudicação do membro pélvico em cães e a osteotomia do nivelamento do platô tibial (TPLO) um dos tratamentos mais recomendados. No entanto, este procedimento pode apresentar algumas complicações como fratura da fibula, lacerações em graus variados da vascularizaçaõ poplitea e suas ramificações, neuropraxias, neurotmeses, entre outras. Os onjetivos deste estudo foram comparar a eficácia de oito métodos de proteção utilizados durante a TPLO para prevenir danos à artéria tibial cranial, fíbula e nervos tibial e fibular (compressas cir[urgicas, afastadores cirúrgicos específicos e variação da técnica de osteotomia). Materiais, Métodos e Resultados: Quarenta cadáveres de cães pesando 25.9 ± 3.7 Kg foram submetidos à TPLO. OS animais foram previamnete preparados com solução 1:4 de látex baritado vermelho, de modo a garantir radiopacidade das artétias próximas do joelho (n=80). A TPLO foi executada utilizando oito métodos para proteção da artéria tibial cranial, fibula e nervos tibial e fibular. Cada método foi usado em apenas um dos joelhos de cinco animais. O joelho contralateral foi utilizado como controle (sem proteção). Os joelhos foram radiografados em projeções ortogonais antes e após a osteotomia e posteriormente dissecados anatomicamente. As estruturas avaliadas foram fotografadas e as imagens enviadas para quatro avaliadores cegos (macroscopia visual) para classificar possíveis injurias. A maior incidência de lesões foram observadas quando os métods de proteção foram utilizados. No entanto, esta diferença não se mostrou significativa (p>0,05). Quanto a eficácia de proteção entre os métodos, não houve diferença significativa. Discussão: Neste estudo, a incidência total de lesões após a TPLO foi de 20%, muito além da encontrada na literatura, quando consisera-se apenas as lesões transoperatorias. A resitência tecidual dos cadáveres e do latex endurecido pode ter predisposto ao dano na osteotomia, uma vez que tecidos moles possuem uma flexibilidade maior e são menos suceptiveis ao trauma causado pela serra oscilatória. Quando comparado a outros estudos cadavericos que também buscaram avaliar a eficácia de compressas cirúrgicas como método de proteção a artéria tibial cranial durante a TPLO, também encontramos uma incidência maior. Talvez, esta diferença, se deva pela posição do membro, uma vez que nos trabalhos mencionados, os pesquisadores mantiveram os membros numa posição suspensa, simulando o decubito dorsal e nós adotamos o membro com sua face lateral em contato com a mesa cirúrgica e, talvez isto, tenha gerado uma maior pressão nas estruturas contra a linha de osteotomia, aumentando a ocorrência dos danos. Apesar de o presente trabalho não mostrar diferença estatísitica significativa quanto ao uso dos métodos de proteção, acreditamos que a dimensão das compressas  utiizadas pode ter contribuidos para uma incidencia maior de lesão. Provavelmente elas aumentaram o trauma tecidual necessária para sua alocação e levaram a uma menor acurácia do posicionamento para proteção das estruturas. talvez pelo mesmo motivo, o afastador específico tipo II foi o único método que, de forma observacional, não aumentou o risco de lesão, uma vez que seu posicionamento exigia uma dissecação menor. A diferença da forma geometrica e dimensões dos afastadores pode justificar a superioridade do segundo, uma vez que permite um posicionamento mais preciso e menos traumático. Realizar a TPLO sem estes métodos de proteção não aumentaram o risco de lesão a artéria tibial cranial, fibula e nervos tibial e fibular