Artificial phrenoesophageal ligament. An experimental study in dogs.

This report deals with the preparation of a 'true' artificial phrenoesophageal ligament aimed at restoring effective anchoring of the esophagus to the diaphragm, keeping the esophagogastric sphincter in the abdomen. A total of 24 mongrel dogs were assigned to four groups: (i) Group I (n = 4): the esophageal diaphragm hiatus left wide open; (ii) Group II (n = 8): the anterolateral esophagus walls were attached to the diaphragm by the artificial ligament and the esophageal hiatus was left wide opened; (iii) Group III (n = 5): in addition to the use of the artificial ligament, the esophageal hiatus was narrowed with two retroesophageal stitches; (iv) Group IV (n = 7): the only procedure was the esophageal hiatus narrowing with two retroesophageal stitches. The phrenoesophagogastric connections were released, sparing the vagus nerves. Five animals of groups III and IV, which did not develop hiatal hernia, were submitted to esophageal manometry immediately before and 15 days after surgery. In group I, all animals developed huge sliding hiatal hernias. In group II, two dogs (25%) had a paraesophageal hernia between the two parts of the artificial ligament. In group III, neither sliding hiatal hernia nor paraesophageal hernia occurred. In group IV, two animals (28.6%) developed sliding esophageal hiatus hernia. Regarding esophageal manometry, postoperative significant difference between groups III and IV (P = 0.008) was observed. Thus, the artificial phrenoesophageal ligament maintained the esophagus firmly attached to the diaphragm in all animals and the esophagogastric sphincter pressure was significantly higher in this group.

Massive tracheal necrosis due to compression by an innominate artery aneurysm associated with a grade IV Chagasic megaesophagus and chronic duodenal ulcer.

A 49-year-old man suffered necrosis of the cephalad tracheal segment due to compression by an innominate artery aneurysm. A peritracheal abscess, a grade IV chagasic megaesophagus, and a duodenal ulcer were also present. The patient underwent a three-stage surgical treatment, and 7 years later he is doing well, and breathing and eating normally.

Intermittent anterograde normothermic blood cardioplegia: experimental study in rabbits.

BACKGROUND: We investigated the degree of myocardial protection provided by intermittent anterograde normothermic blood cardioplegia infusion for 60 minutes at 37 degrees C in normal rabbit hearts. METHODS: Thirty-two New Zealand rabbits were studied and divided into two groups: experimental group and control group. In the experimental group, normothermic blood cardioplegia was infused into the aortic root every 20 minutes over a one-hour period using a two-minute infusion dose. This amounted to an ischemic (unperfused) time of 52 minutes (or 86.6% of the total time). The biochemical investigation was carried out in two phases; Phase I: metabolic study after ischemia with no reperfusion and Phase II: metabolic and functional study after reperfusion. Reperfusion was carried out using a parabiotic perfusion system. Myocardial glycogen and mitochondrial respiration in the ventricular myocardium were established immediately after the end of intermittent cardioplegic solution infusion (Phase I) and after blood reperfusion (Phase II), when left ventricular function (dP/dt max) was also evaluated. RESULTS: At the end of Phase I, there was a significant decrease in myocardial glycogen levels to 58% compared with the control group. In Phase II, the differences in myocardial glycogen between the experimental and the control group were not significant. Mitochondrial respiration analysis did not show significant differences between the experimental and control groups, either in Phase I or II. In Phase I, dP/dtmax values were 903.39 +/- 113.46 mmHg/sec and 1,043 +/- 256.94 mmHg/sec for the experimental and control group, respectively. These differences were not statistically significant. CONCLUSIONS: Intermittent anterograde blood cardioplegia infusion every 20 minutes for 60 minutes at 37 degrees C was an effective myocardial protection method in normal rabbit hearts.

Use of the platysma myocutaneous flap for cervical trachea reconstruction: an experimental study in dogs.

Cervical trachea reconstruction with a non-stented platysma myocutaneous door flap (NPMCF) was studied in 23 dogs. Window defects involving 5, 10, or 15 rings and the whole anterior tracheal wall were produced in 3 different groups of animals. A segmentary defect involving the resection of 3 tracheal rings but preserving the posterior membranous wall was created in another group. The results were evaluated by clinical follow-up of up to 100 days, by tracheoscopy 1 week after surgery, and by macroscopic and microscopic examination after the animals' natural death or sacrifice. The NPMCF proved to be adequate for the reconstruction of window defects limited to 5 and 10 rings, with success rates of 100% and 75%, respectively. The use of the NPMCF for tracheal reconstruction had the following main advantages: 1. relatively simple, easy, and expeditious surgery; 2. use of a single operative field; 3. availability of large amounts of donor tissue; 4. adequate thickness; 5. reliable irrigation; 6. resistance to environmental exposure as evidenced by absence of infection; and 7. 100% take rate with no granulomas or scar stenosis at the suture lines. However, luminal occlusion due to flap collapse was a 100% fatal complication when the NPMCP was used either for reconstruction of larger window tracheal defects (15 rings-group 3) or segmentary defects (group 4); this was the main limitation of the method, followed by hair growth with accumulation of secretions, which can be easily dealt with. It can be anticipated that this method has a potential for application in well-selected patients.

Viability of single-pedicled tracheal flaps: an experimental study

The objective of the present study was to test the viability of tracheal flaps of different widths and lenghts for tracheal reconstruction in dogs, as well as the location of their pedicles. Six types of single-pedicled tracheal flaps were prepared in 30 dogs as follows: narrow flaps with upper pedicles,wide flaps with upper pedicles, narrow flaps with lower pedicles, wide flaps with lower pedicles, narrow flaps with side pedicles, and wide flaps with side pedicles. Flap condition was determined on the basis of clinical signs and by tracheoscopic, macroscopic and microscopic examination. No statistically significally significant difference in viability was observed between narrow and wide flaps or between flaps with upper and lower pedicles, but all were less viable than side-pedicled flaps. Poor coaptation of the flap borders produced deformities of tracheal architecture, with a significant incidence of necrosis occurring in in poorly postioned flaps. The presence of poor coaptation was statistically significant in narrow flaps. Focal infection appears to influence the development of necrosis. We did not observe fibrosis or granulation tissue in sufficient amounts to cause significant stenosis of the tracheal lumen. We conclude that single-pedicled tracheal flaps are viable and can be used for tracheal reconstruction when they are prepared with a lengh-width ratio of 5 to 10

[Surgical treatment of dysphagia lusória]. / Tratamento cirúrgico da disfagia lusória.

Two cases of this anomaly, in women (26 and 49 years old), with symptoms of short duration (4 and 3 months) of dysphagia, regurgitation and esophagitis, without loss of weight, are presented. In both, the final diagnosis was made by mean of thoracic aortogram. Esophagoscopy realized only in the first patient, demonstrated the pulsatile esophageal compression. The first patient was operated on through a right cervical incision, made in the anterior border of the sternomastoid muscle. In the second, a partial sternotomy, combined with a right supraclavicular prolongation, was used. In both, the anomalous artery was taken from the aorta and behind the esophagus, and anastomosed to the right common carotid artery. The dysphagia disappeared in the second case, but persisted attenuated, in the first one. Manometric studies realized in the 3rd and 18th months postoperatively demonstrated an aperistaltic segment of the esophagus (between 4 and 7 cm from the superior sphincter).

Viability of single-pedicled tracheal flaps: an experimental study.

1. The objective of the present study was to test the viability of tracheal flaps of different widths and lengths for tracheal reconstruction in dogs, as well as the location of their pedicles. 2. Six types of single-pedicled tracheal flaps were prepared in 30 dogs as follows: narrow flaps with upper pedicles, wide flaps with upper pedicles, narrow flaps with lower pedicles, wide flaps with lower pedicles, narrow flaps with side pedicles, and wide flaps with side pedicles. 3. Flap condition was determined on the basis of clinical signs and by tracheoscopic, macroscopic and microscopic examination. 4. No statistically significant difference in viability was observed between narrow and wide flaps or between flaps with upper and lower pedicles, but all were less viable than side-pedicled flaps. 5. Poor coaptation of the flap borders produced deformities of tracheal architecture, with a significant incidence of necrosis occurring in poorly positioned flaps. The presence of poor coaptation was statistically significant in narrow flaps. Focal infection appears to influence the development of necrosis. We did not observe fibrosis or granulation tissue in sufficient amounts to cause significant stenosis of the tracheal lumen. 6. We conclude that single-pedicled tracheal flaps are viable and can be used for tracheal reconstruction when they are prepared with a length-width ratio of 5 to 10.

Impairment of baroreflex control of the sinoatrial node after cardiac operations with extracorporeal circulation in man.

The sensitivity of the baroreceptor reflex to transient hypertension was determined in 13 patients before (control) and after (72 hours) open cardiac operations with extracorporeal circulation (ECC). In all patients early postoperative values were appreciably decreased (p less than 0.01) as compared to the preoperative values. This decrease suggested severe impairment of baroreflex control of the sinoatrial node. These changes were not correlated with concurrent alterations in heart rate or systemic arterial, left atrial, or right atrial pressures. In addition, respiratory sinus node arrhythmia was absent in all subjects. In four patients, subsequent studies 4, 8, 10, and 12 months, respectively, after the operation revealed good recovery of baroreflex sensitivity and respiratory influences on beat-to-beat variation. No similar effects were observed in two patients studied before and after cardiac operations without ECC. It is possible that direct trauma to the nervous supply of the sinoatrial node is a major factor in that reversible dysfunction; in fact, in three patients evidence was obtained that while sinoatrial node responses were impaired, the reflex control of the atrioventricular region remained unaltered. These findings point to further impairment of the fine control of heart rate imposed by the conditions of cardiac operations with ECC in patients with previously curtailed cardiac reserve.

Intraoperative measurement of the orifice area in patients with mitral valve stenosis.

This study was carried out in ten patients in order to compare results of mitral valve area evaluated by a new intraoperative technique and those provided by conventional hemodynamic methods. The results obtained correlated very well (r = 0.95) with values calculated by the Gorlin formula. Paired data checking were closer than 0.3 cm2 in all but one of patients with moderately severe mitral stenosis. It is concluded that the method for intraoperative measurement of the mitral valve area is simple, safe and reliable.

Protese traqueal - estudo experimental em caes. / Tracheal prosthesis experimental study in dogs

Este trabalho destinou-se a estudar um novo substituto traqueal. Usando uma placa proteica de poliester (Rhodergon), revestida por silicone em uma de suas faces, a protese traqueal era moldada em cilindros de acrilico de tamanhos diferentes. Foram feitas nao colapsaveis atraves de aneis metalicos incompletos, aplicados a sua face externa e protegidos por uma fina camada de silicone. Onze caes mesticos tiveram um segmento de sua traqueia cervical (de tres a cinco aneis cartilaginosos) substituidos por uma dessas proteses. As anastomoses foram realizadas usando-se fios de sutura monifilamentares (polipropileno prolene 5-0) em tecnicas diferentes. Os resultados foram avaliados atraves de observacoes clinicas, radiograficas, endoscopicas. Finalmente todos os animais foram para autopsia. A protese traqueal mostrou-se satisfatoria como um conduto aereo nao colapsavel mas os resultados obtidos foram insatisfatorios em virtude da ocorrencia de infeccao, deiscencia e estenose

Área valvar mitral e capacidade física determinada pelo teste cicloergométrico em pacientes portadores de estenose mitral / Mitral valve area and physical capacity determined by cycloergometric test in patients with mitral stenosis

Os autores estudaram 18 pacientes portadores de estenose mitral, relacionando a capacidade fisica determinada pelo teste cicloergometrico com a area valvar medida durante a cirurgia e com parametros hemodinamicos obtidos pelo cateterismo cardiaco realizado em 8 pacientes. Todos valvopatas apresentaram baixos valores para a capacidade fisica independente da area valvar mitral, da atividade profissional e do uso terapeutico de digoxina. Sugere-se, como conclusao, que o teste cicloergometrico, para os pacientes com estenose mitral estudados, nao trouxe contribuicao para a indicacao da correcao cirurgica da estenose valvar, uma vez que nao foram obtidas relacoes entre a area util valvar mitral, a capacidade funcional, e, entre esta e os dados hemodinamicos obtidos pelo cateterismo cardiaco venoso

Correlações entre a medida intra-operatória da área útil valvar com parâmetros clínicos e hemodinâmicos em pacientes portadores de estenose mitral / Correlation of intraoperative measurement of valvar useful area with clinical and hemodynamic parameters in patients with mitral stenosis

No presente trabalho, estudou-se a area util valvar mitral,medida intraoperatoriamente pelo metodo proposto por Sader(1975) e sua correlacao com parametros clinicos e hemodinamicos de pacientes portadores de estenose mitral. Obteve-se correlacao significante entre a area valvar mitral e o grau funcional de acordo com New York Heart Association. Obtiveram-se tambem correlacoes significantes (p < 0,05) entre a area valvar mitral, indice cardiaco,fluxo atraves da valva mitral, resistencia vascular sistemica, resistencia arteriolar sistemica, resistencia pulmonar estabelecida pela valva estenotica e resistencia vascular pulmonar. Nao se obtiveram correlacoes significantes (p < 0,05) com a pressao capilar pulmonar, gradiente atraves da valva mitral, resistencia arteriolar pulmonar, trabalho do ventriculo direito e trabalho do ventriculo esquerdo

Estudo do fluxo sanguineo periferico medico pela pletismografia de oclusao venosa em pacientes portadores de estenose mitral. / Peripheral blood flow measured by plethysmography of venous occlusion in patients with mitral stenosis

Realizaram-se medidas do fluxo sanguineo periferico do pe, por plestimografia de oclusao venosa em 11 pacientes portadores de estenose mitral, submetidos a cateterismo cardiaco, e a medida da area util da valva mitral durante intervencao cirurgica Os valores foram baixos na maioria dos pacientes e a correlacao entre o fluxo sanguineo periferico e a area util da valva mitral bem como o indice cardiaco, volume sistolico e resistencia arteriolar sistemica nao foram extatisticamente significantes.Concluem que os achados nao sugerem que o fluxo sanguineo periferico dependa do grau de estenose da valva.Diante do volume de informacoes que contestam a participacao universal do sistema nervoso autonomo simpatico os autores invocam a autorregulacao local para explicar as respostas da circulacao periferica nos portadores de estenose mitral