published_or_final_version / Dentistry / Master / Master of Dental Surgery

Thesis (M.D.S.)--University of Hong Kong, 2000. / Includes bibliographical references (leaves 138-164).

Thesis (M.D.S.)--University of Hong Kong, 2000. / Includes bibliographical references (leaves 138-164). Also available in print.

CoordenaÃÃo de AperfeiÃoamento de Pessoal de NÃvel Superior / The therapeutic use of Varfarin, the most common oral anticoagulant it is indicated in many cases, including the atrial fibrillation, cardiac valvular prostheses and venous trombolic disease. Many discussions still exist related to the suspension or not before tooth extraction. People who are for itâs suspension agree that it may increase the risk of hemorrhage, however the ones who prefer to maintain itâs use refer the high risk of tromboembolism. Due to the controversy related to the cronic use of oral anticoagulant before tooth extraction and what to use to control bleeding after extraction, we decided to perform a one center randomized clinical trial study to compare the effectiveness of the hemostasis using soaked gauze with tranexamic acid at 4,8% and plain gauze and the use of collagen sponge (HemosponÂ), using it inside the tooth socket after extraction. The sample was made of 84 surgical procedures performed in 38 patients who were under anticoagulant treatment and who needed at least one tooth extraction. The trial was divided in three groups regarding the method used to reach hemostasis after tooth extraction. In group I we used compression with soaked gauze with tranexamic acid at 4,8%; in group II we used collagen sponge (HemosponÂ) inside the socket while in group III we compressed the socket with dry gauze for 8 minutes. There were two cases of post surgical bleeding, being one from group I and one from group II. The data collected was evaluated thru SPSS 1.5 (Statistic Package of Social Science) program. All the statistical analysis performed were considered significantly when p was less than 5%. We used the Qui square X2 Test, Fisher Exact Test e Analysis of Variance (ANOVA) to verify the variables of the data. There was no statistically significant difference between the groups, related to bleeding (p>0,05). The compression with dry gauze and suture, compression with soaked gauze with trenaxamic acid at 4.8% and suture and the use of collagen sponge (HemosponÂ) in the tooth socket hold with suture showed similar efficacy to the control of post extraction bleeding in patients who are under anticoagulant treatment. / A terapÃutica com varfarina, o anticoagulante oral mais utilizado, està indicada em mÃltiplas situaÃÃes, incluindo a fibrilaÃÃo atrial, prÃteses valvulares cardÃacas e o tromboembolismo venoso. DiscussÃes ainda existem sobre a indicaÃÃo ou nÃo da sua interrupÃÃo prÃvia a realizaÃÃo de exodontias. Aqueles que defendem a parada de sua administraÃÃo baseiam tal decisÃo no risco aumentado de hemorragias, enquanto os que acreditam na manutenÃÃo da terapia ressaltam o risco de tromboembolismo. Em virtude das controvÃrsias acerca da realizaÃÃo de exodontias em pacientes que fazem uso crÃnico de anticoagulantes orais, alÃm da dÃvida de que mÃtodo empregar no controle do sangramento pÃs-exodontia, decidimos realizar um estudo do tipo ensaio clÃnico, unicÃntrico, randomizado com o objetivo de comparar a efetividade hemostÃtica local da compressÃo com gaze embebida ou nÃo em Ãcido tranexÃmico à 4,8% com o emprego da esponja de colÃgeno (HEMOSPONÂ) no interior do alvÃolo pÃs-exodontia. A amostra foi constituÃda por 84 procedimentos cirÃrgicos realizados em 38 pacientes sob terapia anticoagulante que necessitavam de pelo menos uma extraÃÃo dentÃria. A amostra foi dividida em trÃs grupos a depender do mÃtodo hemostÃtico local empregado para o controle do sangramento apÃs a extraÃÃo dentÃria. No grupo I utilizou-se a compressÃo com gaze embebida em Ãcido tranexÃmico a 4,8%; no grupo II introduziu-se no interior do alvÃolo uma esponja de colÃgeno (HemosponÂ); enquanto no grupo III, a compressÃo com gaze seca por 8 minutos foi o mÃtodo empregado. Em dois casos foi observado sangramento pÃs-operatÃrio sendo um paciente do grupo I e outro do grupo II. Os dados coletados foram consolidados e avaliados por meio do programa SPSS 15.0 (Statistic Package of Social Science). Todas as anÃlises estatÃsticas efetuadas foram consideradas significativas quando valor de p foi menor que 5%. Utilizou-se os testes Qui-Quadrado (XÂ), Teste Exato de Fisher e AnÃlise de VariÃncia (ANOVA) para verificar as diferenÃas entre as variÃveis. NÃo houve diferenÃa estatisticamente significante entre os grupos com relaÃÃo à ocorrÃncia de hemorragias (p-valor>0,05). A compressÃo com gaze seca associado à sutura, a compressÃo com gaze embebida com Ãcido tranexÃmico a 4,8% associada a sutura e o emprego da esponja de fibrina (HemosponÂ) intra-alveolar associado a sutura mostraram eficÃcia semelhante no controle do sangramento pÃs-exodontia em pacientes sob terapia anticoagulante.

Coagulation has and continues to be one of the most important elements in medicine. Issues from a lack of hemostasis range from poorer clinical outcomes to sudden death. The evolution of treatments for hemostasis have evolved from the use of Tamponade with direct pressure and bandages, the use of materials such as cobwebs and dust, the use of heat with hot oil or heated irons, to the use of suture, glues, plasmas, staplers, and electricity. This evolution has continued to bring about the prophylactic use of technology in an effort to prevent blood loss. This change from reactive treatments to proactive continue to be on a localized or superficial basis. One of the largest opportunities to proactively reduce blood loss in surgical patients is during the resection of solid organs such as the liver, kidney, and spleen. Few options have existed to help improve hemostasis short of the complete occlusion of blood supplying the tissue such as in the Pringle Maneuver. Recent studies have begun to show that practices such as this may have a significant detrimental effect on morbidity. It has been found that by applying radio frequency electrical energy in a particular way that large amounts of tissue can be pre-coagulated prior to resection. A series of animal and human clinical work has been completed to help evolve and confirm the method and the device that was created and refined during this effort. During the course of this work fifty-three patients were treated at four institutions on three continents. Average blood loss for liver resections performed with this pre-coagulation technique using the developed device in a multicenter control trail was 3.35 ml/cm2 as compared to 6.09 ml/cm2 (p < 0.05) for resections performed using standard surgical techniques alone. Additionally, the transection time necessary was also reduced from mean value of 27 minutes (2 -- 219 minutes) to 35 minutes (5 -- 65 minutes). Patients treated included those suffering from liver cirrhosis, fatty liver disease, and post chemotherapy fibrosis. From this work the use of pre-coagulation with methods and device developed was shown to be safe and effective for reducing the amount of blood loss and transection time during liver resections.

Coagulation has and continues to be one of the most important elements in medicine. Issues from a lack of hemostasis range from poorer clinical outcomes to sudden death. The evolution of treatments for hemostasis have evolved from the use of Tamponade with direct pressure and bandages, the use of materials such as cobwebs and dust, the use of heat with hot oil or heated irons, to the use of suture, glues, plasmas, staplers, and electricity. This evolution has continued to bring about the prophylactic use of technology in an effort to prevent blood loss. This change from reactive treatments to proactive continue to be on a localized or superficial basis. One of the largest opportunities to proactively reduce blood loss in surgical patients is during the resection of solid organs such as the liver, kidney, and spleen. Few options have existed to help improve hemostasis short of the complete occlusion of blood supplying the tissue such as in the Pringle Maneuver. Recent studies have begun to show that practices such as this may have a significant detrimental effect on morbidity. It has been found that by applying radio frequency electrical energy in a particular way that large amounts of tissue can be pre-coagulated prior to resection. A series of animal and human clinical work has been completed to help evolve and confirm the method and the device that was created and refined during this effort. During the course of this work fifty-three patients were treated at four institutions on three continents. Average blood loss for liver resections performed with this pre-coagulation technique using the developed device in a multicenter control trail was 3.35 ml/cm2 as compared to 6.09 ml/cm2 (p < 0.05) for resections performed using standard surgical techniques alone. Additionally, the transection time necessary was also reduced from mean value of 27 minutes (2 -- 219 minutes) to 35 minutes (5 -- 65 minutes). Patients treated included those suffering from liver cirrhosis, fatty liver disease, and post chemotherapy fibrosis. From this work the use of pre-coagulation with methods and device developed was shown to be safe and effective for reducing the amount of blood loss and transection time during liver resections.