Biomechanical analysis of titanium fixation plates and screws in mandibular angle fractures.

OBJECTIVE: The aim of this study was to evaluate the mechanical behavior of different rigid fixation methods in mandibular angle fractures. MATERIALS AND METHODS: Three different three-dimensional finite element models of the mandible were developed to simulate the biomechanical responses of titanium plates and screws. The fracture lines were fixed with double 4-hole straight, 4-hole square, and 5-hole Y plates with monocortical screws. 150 N incisal occlusal loads were simulated on the models. The commercial ANSYS software was utilized to calculate the Von Mises stresses on fixative appliances. RESULTS: The highest Von Mises stress values were observed in the Y plate, whereas the lowest stress values have been found in the square plate. CONCLUSIONS: The use of square plate led to better stability and lower mechanical stresses than other techniques.

Biomechanical analysis of titanium fixation plates and screws in sagittal split ramus osteotomies.

OBJECTIVE: The aim of the study was to evaluate the mechanical behavior of three different fixation methods used in the bilateral sagittal split ramus osteotomy. MATERIALS AND METHODS: Three different three-dimensional finite element models were created, each corresponding to three different fixation methods. The mandibles were fixed with double straight 4-hole, square 4-hole, and 5-hole Y plates. 150 N incisal occlusal loads were simulated on the distal segments. ANSYS software ((v 10; ANSYS Inc., Canonsburg, PA) was used to calculate the Von Mises stresses on fixative appliances. RESULTS: The highest Von Mises stress values were found in Y plate. The lowest values were isolated in double straight plate group. CONCLUSIONS: It was concluded that the use of double 4-hole straight plates provided the sufficient stability on the osteotomy site when compared with the other rigid fixation methods used in this study.

Partial deletion of the long arm of chromosome 13 (q32q33.2) associated with mental retardation, choanal atresia and fish mouth.

13q deletion syndrome is characterized by mental and motor retardation, craniofacial dysmorphic facial appearance and various congenital malformations. In this article, we present a new case with 13q deletion syndrome phenotypically characterized by fish mouth, choanal atresia and severe mental and motor retardation. In order to determine the certain localization of deleted region high resolution multicolor-banding technique was performed and the karyotype determined as 46,XX,del(13)(q32q33.2). To come in future to a genotype-phenotype correlation, it is very important to delineate the deleted region in such cases in detail by cytogenetic/ molecular cytogenetic methods.

Early and late rejection and HLA sensitization at the time of heart transplantation in patients bridged with left ventricular assist devices.

Over the years, the frequency of heart transplant candidates with HLA sensitization has increased as a result of the number of patients bridged to transplant using left ventricular assist devices (LVAD). Here we have examined 119 patients who were bridged to transplant with LVAD for a relationship between HLA antibodies and early (30 days) and late (2 years or more) rejection, as evidenced by endomyocardial biopsies. Both cytotoxic panel-reactive antibody reactions against a panel of T lymphocytes (T-PRA) and the percentage of transplants that occurred across a positive class I flow cross-match were examined. Biopsies were scored using ISHLT criteria. At 30 days, patients who had a biopsy grade of 0 had a mean T-PRA at transplant of 2.2%, while the mean PRAs of the other biopsy grades were significantly higher (P < .001). A similar pattern was seen with the highest biopsy results at 2 years or later (P < .001). None of the patients who had a grade 0 biopsy at 30 days posttransplant had a positive flow cytometry class I cross-match (P = .02), although the same pattern did not occur later due to a small number of patients (n = 3) who had negative biopsies. Thus, when biopsy results were examined early or late posttransplant, patients with negative biopsy results tended to have less HLA sensitization. While the methods of HLA sensitization involve humoral responses, more aggressive immunosuppression might be warranted to attempt to reduce cellular rejection posttransplant if HLA class I antibodies are present at the time of transplant.

Large intestine obstruction complicated with perforation: a rare manifestation of Schistosoma mansoni infection.

The authors report a case of a 25 year old Brazilian man with a history of crampy abdominal pain in the left iliac fossa for 2 weeks, abdominal distention, mucous diarrhea and anorexia. The patient presented signs of hemodynamic instability and a hard mass palpated in the left iliac fossa presented peritoneal irritation. At laparotomy, fecal peritonitis and a punched-out perforation of the midsigmoid colon were found. A left hemicolectomy was performed with terminal colostomy. Specimen examination revealed a thickened rectosigmoid wall, narrow lumen and multiple mucosal polyps. Microscopically, chronic granulomatous colitis with Schistosoma mansoni eggs confirmed the etiology. To the authors' knowledge, this is the first case of obstruction complicated with perforation due to mansoni schistosomiasis reported in the literature.

Myocardial revascularization with coronary endarterectomy. Stratification of risk factors for early mortality.

OBJECTIVE: To determine the risk factors for mortality related to myocardial revascularization when performed in association with coronary endarterectomy. METHODS: We assessed retrospectively 353 patients who underwent 373 coronary endarterectomies between January '89 and November '98, representing 3.73% of the myocardial revascularizations in this period of time. The arteries involved were as follows: right coronary artery in 218 patients (58.45%); left anterior descending in 102 patients (27.35%); circumflex artery in 39 patients (10.46%); and diagonal artery in 14 patients (3.74%). We used 320 (85.79%) venous grafts and 53 (14.21%) arterial grafts. RESULTS: In-hospital mortality among our patients was 9.3% as compared with 5.7% in patients with myocardial revascularizations without endarterectomy (p=0.003). Cause of death was related to acute myocardial infarction in 18 (54.55%) patients. The most significant risk factors for mortality identified were as follows: diabetes mellitus (p=0.001; odds ratio =7.168), left main disease (<0.001; 9.283), female sex (0.01; 3.111), acute myocardial infarction (0.02; 3.546), ejection fraction <35% (<0.001; 5.89), and previous myocardial revascularization (<0.001; 4.295). CONCLUSION: Coronary endarterectomy is related to higher mortality, and the risk factors involved are important elements of a poor outcome.

[Supravalvar and valvar aortic stenosis associated with valvar and subvalvar pulmonary stenosis. Coexistence of two clinical syndromes]. / Estenose supravalvar e valvar aórtica associada à estenose infundíbulo valvar pulmonar. Coexistência de duas síndromes clínicas.

A 4 year old patient with congenital rubella syndrome, confirmed serologically, presents with neurosensorial deafness and a rare association of cardiac anomalies: supravalvar and valvar aortic stenosis and subvalvar pulmonary stenosis. Bidimensional echocardiography and angiography confirmed the diagnosis and the surgical treatment was successful. Due to the presence of somatic characteristics of Williams's syndrome, mental retardation and supraortic stenosis, the authors postulate that there is a coexistence of clinical syndromes responsible for the malformations of this case. This fact is rare on clinical settings, requiring accurate diagnosis and treatment.

Immediate and long term evolution of valve replacement in children less than 12 years old.

OBJECTIVE: The aim of this work was the follow-up and evaluation of valve replacement in children under 12 years of age. METHODS: Forty-four children less than 12 years old were underwent valve replacement at INCOR-HCFMUSP between January 1986 and December 1992. Forty (91%) were rheumatic, 39 (88.7%) were in functional classes II or IV, 19 (43.2%) were operated upon on an emergency basis, and 6 (13.6%) had atrial fibrillation. Biological prostheses (BP) were employed in 26 patients (59.1%), and mechanical prostheses (MP) in 18 (40.9%). Mitral valves were replaced in 30 (68.7%), aortic valves in 8 (18.2%), a tricuspid valve in 1 (2.3%), and double (aortic and mitral) valves in 5 (11.4) of the patients. RESULTS: Hospital mortality was of 4.5% (2 cases). The mean follow-up period was 5.8 years. Re-operations occurred in 63.3% of the patients with BP and in 12.5% of those with MP (p=0.002). Infectious endocarditis was present in 26.3% of the BP, but in none of the cases of MP (p=0.049). Thrombosis occurred in 2 (12.5%) and hemorrhage in one (6.5%) of the patients with a MP. Delayed mortality occurred in 5 (11.9%) of the patients over a mean period of 2.6 years; four had had BP and one had a MP (NS). Actuarial survival and re-operation-free curves after 10 years were respectively, 82.5+/-7.7 (SD)% and 20.6+/-15.9%. CONCLUSION: Patients with MP required fewer re-operation, had less infectious endocarditis and lower late mortality rates compared with patients with bioprostheses. The former, therefore, appear to be the best valve replacement for pediatric patients.

[Ischemic mitral valve insufficiency. Incidence, diagnosis and surgical treatment]. / Insuficiência valvar mitral isquêmica. Incidência, diagnóstico e tratamento cirúrgico.

PURPOSE: To study the incidence of ischemic mitral regurgitation (MR) and the mortality. METHODS: One-hundred-five cases of acute myocardial infarction (AMI) with MR were reviewed. Patients were divided in two groups: group A-59 (56.2%) necropsied patients without previous surgical procedures to correlate clinical pictures with the aim to determine the cause of death; group B-46 (43.8%) patients were submitted to surgical treatment. This group was subdivided in mild, moderate and severe forms of MR, and studied comparatively the type of surgical treatment and its evolution. RESULTS: Group A-23 (39%) patients with mild forms and predominant ischemic heart disease, responsible for death; 18 (30.5%) patients without previous diagnosis, masked by myocardial failure and 18 (30.5%) with severe MR and coronary heart disease; group B-14 (30.4%) patients died at the immediate post-operatory period. Higher mortality associated to ejection fraction (EF) below 35% (47.6%; p = 0.022), severe MR (41.7%; p = 0.044) and cardiogenic shock (52.9%; p = 0.14). In 41 (89.1%), the mitral valve repair was combined to coronary artery bypass grafting operation (CABG), in 4 (8.7%) this last procedure was made without mitral repair and in the remaining patients the surgery was limited to the valve. Mitral valvuloplasty was performed in 23 (50%) patients with 3 (13%) deaths, and in 19 (42.3%) the mitral valve was replaced with 9 (47.4%) deaths. CONCLUSION: The prognosis is related to the grade of EF and to the severity of MR. In mild to moderate forms, the surgical indication is due to the associated coronary heart disease and the valvuloplasty is preferred, in this instance. In severe forms, surgical intervention must be performed as soon as possible, before cardiogenic shock appears.

[Obstruction of terminal ileum due to heterotopic gastric mucosa]. / Obstrução do íleo terminal por mucosa gástrica heterotópica.

Heterotopic gastric mucosa situated in the small bowel distal to the Treitz suspensory ligament is very rare, except in Meckel's diverticulum and in intestinal duplications. There are two forms of this disease, congenital and acquired. The former is secondary to inflammatory bowel disease. The main difference between these forms is histological, although determining diverse physiopathological aspects. A case of a 34 year old man with heterotopic gastric mucosa in the terminal ileum manifested by intestinal obstruction is reported. He was treated surgically by enterectomy of two small bowel segments, both reconstructed by primary suture. His postoperative course was remarkable. The histopathologic study showed a typical pattern of the acquired type because of the presence of antral the antral mucosa and intense fibrosis. That is probably related to intestinal tuberculosis, but was not histologically confirmed. Individual and family recent history of pulmonary tuberculosis corroborates the suspicion. This is a unique report in the literature, among 28 other heterotopic gastric mucosa situated in the jejunum and ileum.

Endoscopic versus open radial artery harvesting for coronary artery bypass grafting.

AIM: The radial artery has become the artery of choice after the internal thoracic artery for coronary artery bypass grafting (CABG). This study compares wound healing and arm complications after endoscopic versus open radial artery harvesting for CABG. METHODS: From January 2002 to July 2004, 509 patients underwent CABG in which a radial artery conduit was used. Thirty-nine had endoscopic and 470 had conventional open radial artery harvesting. A propensity score was used to obtain 1:3 matching of all endoscopic to 117 open-harvesting patients. Postoperative wound healing using the Hollander scale, local neurologic deficits, wound infection, and pain scores were compared. RESULTS: Wound healing: 34 of 39 endoscopic wounds exhibited a perfect Hollander score versus 339 of 470 open-harvest wounds (P=0.01). Wound appearance in particular was better than for open harvesting (P=0.004), with no abnormal step-off borders, irregular contours, or abnormal scar width observed. Neurologic deficits. Three incomplete neurologic deficits were observed after open harvesting (two being distal sensitivity localized in the interspace between the first and second metacarpals); one complete neurologic deficit occurred after endoscopic harvesting, but improved remarkably prior to hospital discharge. Wound infection. Occurrence of wound infection was similar in the two groups (P=0.7), although infection was more severe with open harvesting. Pain: pain score was lower (P=0.006) with endoscopic harvesting. CONCLUSION: Compared with conventional open harvesting, endoscopic radial artery harvesting was associated with better wound appearance and less pain. Occurrence of neurologic deficits and wound infection was infrequent in both groups.

Obstruçäo do íleo terminal por mucosa gástrica heterotópica: relato de caso / Terminal ileum from obstruction owing to heterotopic gastric mucosa: case report

A mucosa gástrica ectópica localizada no intestino delgado, distal ao ligamento de Treitz é muito rara, excetuando-se a encontrada habitualmente no divertículo de Meckel e na duplicaçao intestinal. Existem formas congênita e adquirida, sendo esta última secundária à processos inflamatórios intestinais. As diferenças entre estas formas sao basicamente histológicas, determinando no entanto aspectos fisiopatológicos distintos. Apresentamos caso de mucosa gástrica ectópica em paciente de 34 anos de idade, manifestada por obstruçao do íleo terminal. Submetido a duas enterectomias e anastomoses primárias, apresentou boa evoluçao pós-operatória. O aspecto histopatológico, típico da forma adquirida com mucosa antral e intensa fibrose, foi provavelmente relacionado à quadro recente de tuberculose intestinal, porém nao confirmada histologicamente. O antecedente de tuberculose pulmonar recente na família, aliado à linfoadenomegalia mesentérica encontrada a operaçao, sustentam tal suspeita. Este é fato inédito na literatura dentre as outras 28 publicaçoes de heterotopia gástrica no jejuno e íleo.