Antonio Roberto de Barros Coelho

Surgarcane biopolymer patch in femoral artery angioplasty on dogs

PURPOSE The objective of this study was to evaluate the use of the sugarcane biopolymer membrane in femoral artery patch angioplasty on dogs. METHODS Eight dogs were submitted to bilateral femoral artery patch angioplasty with a sugarcane biopolymer membrane patch on one side and e-PTFE patch on the contralateral side. This research was performed at Experimental Surgical Research Laboratory of the Centro de Ciências da Saúde at Universidade Federal de Pernambuco. The dogs were submitted to a new surgery at 180 days after the patch angioplasty in order to harvest the femoral artery. All the animals were evaluated by: clinical examination, measure of femoral artery diameter, arteriogram and Doppler fluxometry. Yet the material harvested was sent to histological study. Each animal served as its own control. RESULTS In all vessels of both groups there were no cases of infection, aneurysm formation, rupture or pseudoaneurysm formation and thrombosis. In both groups it was observed a chronic inflammatory reaction with lymphocytes, neutrophils and fibrosis in the outer surface of the patches. It was observed fibrosis in the inner surfaces of all the patches. In e-PTFE patches occurred invasion by fibroblasts. CONCLUSION The sugarcane biopolymer membrane can be used as a patch in femoral artery angioplasty on dogs.

Incorporation by host tissue of two biomaterials used as repair of defects produced in abdominal wall of rats

PURPOSE Biomaterials may be used as treatment of great abdominal wall defects to avoid tension during repair. In the present research we intended to investigate incorporation type by host tissue of membranes of microbial cellulose (MC), produced by the bacteria Zoogloea sp., and of polytetrafluoroethylene (ePTFE) in abdominal wall defects of rats. METHODS Sixty male rats Wistar, anesthetized by ketamine (5mg/100g) and xylazine (2mg/100g), were submitted to a rectangular excision (2 x 3cm) of the abdominal wall, including fascia, muscles and peritoneum and further treated with implants of microbial cellulose (MC Group - 30 animals) or expanded polytetrafluoroethylene ( ePTFE Group- 30 animals). Each group was subdivided in 14th DPO, 28th DPO and 60th DPO Subgroups. RESULTS Incorporation of biomaterials was observed by wrapping and infiltration by host tissue. It has been found that wrapping associated to infiltration of host connective tissue in implants of ePTFE were present in 100% of the observed samples, and this may be responsible for increase resistance to traction. Inversely, wrapping without host tissue infiltration was seen in 100% of examined specimens of MC implants. CONCLUSION Wrapping and host tissue infiltration is seen only in ePTFE implants.

Processo modificado de reprodução e amplificação de imagem para mensuração de área por planimetria: Aplicação em feridas planas produzidas em cães, tratadas por curativos oclusivos de pele de rã

Digital image analysis and planimetry are important tools for evaluation of plain wound areas submitted to local treatment. In the proposed process, perimeters of wound areas were obtained in loco by tracing over transparent sheet and further reproduced and amplified by laser copier, precluding the use of photography and developing. The contraction and granulation areas were then measured by planimeter. Epitelization area were determined by difference between the above mentioned areas. Data from measurements and determinations of areas were further transformed in cumulative Percentage of Wound Contraction (PWC), Wound Epitelization (PWE) and Wound Healing (PWH). The proposed process was tested in square shaped lesions (400 mm2), produced in both right and left thoraco-dorsal surfaces of dogs. Seventeen lesion localized in the right thoraco-dorsal region were treated by Rana catesbeiana skin, previous preserved by hypothermia (Test Group). Another 17 lesions in left thoraco-dorsal surface were treated by moistened gauze (Control Group). PWC, PWE and PWH were evaluated at the 7th, 14th, 21th and 28th POD. Macro and microscopic studies showed skin frog destruction, suggestive of rejection phenomenon. It follows that: 1. Changes in reproducing image process permitted to save costs. The reading error of planimeter was ± 0.5%; 2. PWC, PWE and PWH showed non significant differences between Groups. Such equivalence was attributed to destruction of frog skin, suggestive of rejection process.

An experimental study of the electrical activity of the bypassed stomach in the Roux-en-Y gastric bypass

BACKGROUND Surgical options for morbid obesity are diverse, and the Roux-en-Y gastric bypass, initially described by Fobi has gained popularity. Knowledge about the physiology of the bypassed stomach is limited because this newly produced segment of the stomach is inaccessible to endoscopic or contrast radiological studies. AIM To evaluate the myoelectric activity of the bypassed stomach and its reply to the feeding. METHODS An experimental protocol was conducted to evaluate postoperative gastric bypassed motility in dogs submitted to the Roux-en-Y gastric bypass procedure. Two groups of five animals were studied on postoperative fasting and after a standard meal, recording electrical response and control activity. Both control and Roux-en-Y gastric bypass operated study group had a pair of electrodes placed on three points of the remaining stomach: fundus, body and antrum. Data registration was performed after complete ileus resolution, and analysed with DATA Q Inst. series 200. RESULTS The results achieved on the conditions of this study suggest that: 1. the remaining stomach maintain the same pattern of motility; 2. there is a reduced fasting electromyography activity following the Roux-en-Y gastric bypass procedure; 3. significantly reduced fasting electric control activity when compared both groups, and a markedly reduced fasting response electric activity and; 4. the electric response to the feeding kept the same standard of the stomach, however in a statistically reduced way. CONCLUSION The electrical activity of the bypassed stomach of Roux-en-Y gastric bypass procedure kept the same pattern but in a statistically reduced number of contraction.

Cardiocirculatory changes in hemorrhagic shock induced in pigs submitted to three distinct therapeutic methods

PURPOSE To evaluate and compare the response of pigs submitted to hemorrhagic shock and treated using three different strategies. METHODS Thirty-five Dalland pigs were divided into four groups: Control; Bleeding; Saline and Saline + Red Cell Concentrate. Parameters evaluated: heart rate (HR), mean arterial blood pressure (MAP) and central vein pressure (CVP).Hemorrhagic shock was induced by removing (624.25 + or - 64.55), (619.30 + or - 44.94) and (664.23 + or - 39.96) ml of blood respectively, with the following treatment: Bleeding Group - zero volume replacement; Saline Group - replacement with 676 ml of 0.9% saline solution; Saline + Red Cell Concentrate Group - replacement with 440 ml of 0.9% saline solution + 291 ml of red cell concentrate. The treatment was evaluated after 10 (T3), 30 (T4), 45 (T5) and 60 (T6) minutes. RESULTS HR: No statistically significant difference was found between the Bleeding and Saline [p=1.000], Bleeding and Saline + Red Cell Concentrate [p=1.000], and Saline and Saline + Red Cell Concentrate [p=0.721] groups. MAP; Significant differences were found between all the groups studied. CVP: No significant difference was found between the groups. CONCLUSION Non-replacement and euvolemic resuscitation maintained a satisfactory hemodynamic pattern in controlled severe hemorrhagic shock in swine. The euvolemic replacement strategies exceeded the limit values of MAP for rebleeding.

Pele de Rana Catesbeiana como curativo biológico oclusivo no tratamento de feridas cutâneas produzidas em cães: Alterações macroscópicas e microscópicas resultantes da interação desses tecidos. Estudo preliminar

Objective: To study the effect of frog skin as occlusive dressing on cutaneous wounds. Methods: Fifteen mongrel dogs, of both sexes, weighing 9.45 ± 2.62 kg, under general anesthesia, were submitted to 34 square shaped skin lesions, with 400 mm2 of area, on both right and left thoracodorsal surfaces. After defrosting, Rana catesbeiana skins preserved in a ClNa and glycerol solution at ¾4oC were used as biological occlusive dressing on 17 lesion located in the right thoracodorsal region (Test Group). The 17 lesions on the left thoracodorsal side were treated with gauze moistened in a 0.9% ClNa solution (Control Group). The frequency of healed (HW) and non-healed wounds (NHW), and the incidence of frog skin destruction, were analyzed. Five sequences of frog skin samples were histologically examined till tissue destruction started to appear. Inflammatory histological findings were evaluated by percentage of intensity of Polymorphonuclear cells (PPMNC), Mononuclear cells (PMC), and lymphoreticular infiltration (PLI). Two tailed Students t test and chi square test (c2) were used as indicated. Results: 1) There was no significant difference in HW and NHW between Groups; 2) There was a 31.00% incidence of frog skin destruction limited to the surface in contact with dog wounds. An increased tendency of destruction was perceived during the studied period; 3) Histological changes of frog skin, characterized by tissue infiltration mainly from mononuclear cells, and by destruction of Malpighi and subjacent layers, were observed at the surface, limited to the wound contact area; 4) PPMNC values attained were not statistically different between groups. In the Test Group PM prevailed and PLI was exclusively seen. Conclusion: Frog skin is ineffective in treatment of canine cutaneous wounds and rejection was suggested as a causative factor.

Subdiaphragmatic venous stasis and tissular hypoperfusion as sources of metabolic acidosis during passive portal-jugular and caval-jugular bypasses in dogs

Subdiafragmatic venous decompression during anhepatic stage of canine orthotopic liver transplantation attenuates portal and caval blood stasis and minimize hipoperfusion and metabolic acidosis observed with occlusion of portal and caval veins. During two hours, six dogs submitted to portal-jugular and caval-jugular passive shunts, with maintenance of arterial hepatic flow, were evaluated for pH, carbon dioxide tension (PCO2), base deficit (BD) and oxygen tension (PO2) in portal, caval and systemic arterial blood, as well as for increments of BD (DBD) in portal and caval blood. With a confidence level of 95%, the results showed that: 1. There were not changes of pH anDBD in portal and systemic arterial blood in the majority of studied times; 2. There was metabolic acidosis in caval blood; 3. The negative increments of BD (DBD) were higher in caval blood than in splancnic venous blood at T10, T30 and T105; and, 4. Deoxigenation of portal and caval blood were detected. Acid-base metabolism and oxigenation monitoring of subdiaphramatic venous blood can constitute an effective way to evaluate experimental passive portal-jugular and caval-jugular bypass in dogs.

Technique of blind tracheal intubation in rabbits (Oryctolagus cuniculi) supported by previous maneuver of esophageal cannulization

PURPOSE To describe and evaluate a modified technique of blind orotraqueal intubation in rabbits, by supporting of previous cannulization of the esophagus. METHODS Twelve New Zealand rabbits, weighing between 2,780 a 4,140 kg were anesthetized with xilazine (3mg/Kg) and ketamine (20mg/Kg). The animals were positioned in ventral decubitus with the head hyperextend. With one of the hands the anesthetist with the index and thumb fingers positioned in the labial fissures carry on the opening of animal oral cavity. The esophagus was previously cannulized with a tube # 3.5 (3.5mm ID), obstructing its lumen. The trachea lumen was intubated with a probe # 2.5 (2.5mm ID). The positioning of the probe was confirmed through the oscillatory movement of a gauze filament put at outside extremity of tube, resulting from the inspiratory and expiratory flow. RESULTS The success index was of 100%. CONCLUSIONS This technique is of easy execution, high success index, sparing the use of several devices for visualization of the larynx and glottis. No complications were observed. It also serves for short period training of human resources.

Área viável e vascularização, pós autonomização cirúrgica, de retalho pré-fabricado por implante vascular em ratos

The aim of this study was to evaluate the effect of delay procedure on the survival and vasculature of a skin prefabricated flap with mean area rate of the 48.2cm2 in a rat abdominal wall donnor site model. The skin flap was prefabricated by implantation of a distally ligated femoral pedicle into subdermal layer of the skin. Skin of the abdominal wall donnor site of 25 Wistar rats were compared in three groups of flaps receiving (A) pedicle implantation with no delay and (B) and (C) delay performed at the time of pedicle implantation. Three weeks later, the flaps in the group A and B were raised as an island flap, based on the implanted pedicle. In the group C, the implanted pedicle was severed when the flaps were raised. Seven days later, survival area in groups A, B and C were marked and the percentage survival area, with regard to whole flap area, calculated by Auto Cad R-14. The vascular density around the implanted pedicle, in groups A and B, was assessed by histological study. The mean percentage survival rate of the skin flap was 9.6 percent in the nondelayed group, 44.8 percent in the delayed group and 0.3percent in the group with implanted pedicle severed. The results of this study showed that delay procedure significantly increased (p<0.01, two-tailed Mann-Whitney test) the percentages survival of the flap and was found to have no influency over vascular density (p=0.307 two-tailed Mann-Whitney test) developed around the pedicle implantation three weeks after prefabrication.

Avaliação da atividade mioelétrica do trato gastrointestinal em cães: avaliação de um sistema de fixação de eletrodos na parede abdominal

OBJECTIVE: The use of intra-abdominal electrodes in the study of gastrointestinal electrical wave is an important instrument of the gastrointestinal mioelectric activity. However, the dislocations of the electrodes in non-anaesthetized animals due to diaphragmatic muscle movements, gastrointestinal movements and mainly due to the animals habits, especially in dogs. The study has the objective to demonstrate a procedure that stabilize the system using simple resources an irrelevant cost. METHODS: The authors demonstrate under diagrams and picture a fixed system to fix the electrical electrodes through the animal skin using bottoms. RESULTS: The system was used in 5 animals. Each animal had 3 bipolar electrodes. During the study it was not identified any electrode migration. The animals was kept resting until the complete recovery of the postoperative ileus. CONCLUSION: The procedure proposed is efficient, simple, and easy to be made and allow an acquisition of the mioelectric activity, in dogs not anaesthetized, for long periods.