Alloxan-induced diabetes delays repair in a rat model of closed tibial fracture

A closed fracture was performed on the left tibia of 3-month-old Wistar rats weighing 250 to 350 g that were either healthy (N = 24) or made diabetic with alloxan (N = 24) to investigate the effect of alloxan-induced diabetes on the course of bone fracture healing. Histomorphometric analysis of the fracture site was performed at 7, 14, 25, and 35 days. After 7 days, diabetic rats had significantly less cartilage (P = 0.045) and greater fibrous connective (P = 0.006) tissue formation at the fracture site compared to controls. In contrast, marked callus formation was seen in diabetic rats with significant osteogenesis (P = 0.011, P = 0.010, P = 0.010, respectively, for 14, 25, and 35 days) and chondrogenesis (P = 0.028, P = 0.033, P = 0.019) compared to controls. Radiographic analysis revealed a displaced fracture with poor bone fragment alignment and delayed consolidation at these times in the diabetic group. The levels of alkaline phosphatase were significantly higher in diabetic rats at 25 days (P = 0.009). These results suggest that the initial excessive formation of fibrous connective tissue associated with delay in chondrogenesis and osteogenesis may not provide suitable stability of the fractured site, contributing to the inappropriate alignment of fragments and an increase in the volume of callus in later stages of repair. The resulting displaced fracture in diabetic rats requires long periods for remodeling and complete bone consolidation.

Diabetes mellitus affects the biomechanical function of the callus and the expression of TGF-beta1 and BMP2 in an early stage of fracture healing

Transforming growth factor beta 1 (TGF-β1) and bone morphogenetic protein-2 (BMP-2) are important regulators of bone repair and regeneration. In this study, we examined whether TGF-β1 and BMP-2 expressions were delayed during bone healing in type 1 diabetes mellitus. Tibial fractures were created in 95 diabetic and 95 control adult male Wistar rats of 10 weeks of age. At 1, 2, 3, 4, and 5 weeks after fracture induction, five rats were sacrificed from each group. The expressions of TGF-β1 and BMP2 in the fractured tibias were measured by immunohistochemistry and quantitative reverse-transcription polymerase chain reaction, weekly for the first 5 weeks post-fracture. Mechanical parameters (bending rigidity, torsional rigidity, destruction torque) of the healing bones were also assessed at 3, 4, and 5 weeks post-fracture, after the rats were sacrificed. The bending rigidity, torsional rigidity and destruction torque of the two groups increased continuously during the healing process. The diabetes group had lower mean values for bending rigidity, torsional rigidity and destruction torque compared with the control group (P<0.05). TGF-β1 and BMP-2 expression were significantly lower (P<0.05) in the control group than in the diabetes group at postoperative weeks 1, 2, and 3. Peak levels of TGF-β1 and BMP-2 expression were delayed by 1 week in the diabetes group compared with the control group. Our results demonstrate that there was a delayed recovery in the biomechanical function of the fractured bones in diabetic rats. This delay may be associated with a delayed expression of the growth factors TGF-β1 and BMP-2.

Preserved xenogenic amniotic membrane as a patch on the repair of superficial corneal ulcers in rabbits

The aim of this study was to evaluate the effects of canine amniotic membrane, previously preserved in glycerin, used as a patch on the repair of experimentally-made superficial corneal ulcers and to compare corneal epithelization between the treated and non-treated groups. Xenogeneic amniotic membranes were collected aseptically and preserved in 99% glycerin at room temperature. Each animal was anesthetized and submitted to superficial corneal keratectomy of the left eye. The treated group received a fragment of canine amniotic membrane as a patch, while the control group had no treatment. The treated group showed blepharospasm, ocular discharge and conjunctival congestion. The membrane accelerated corneal repair in the beginning of the process, however, it delayed its conclusion (p<0.05). Treated eyes showed greater vessel formation and decreased corneal transparency (p<0.05). The stroma of the control group was thicker than that of the treated group (p<0.05). We suggest that amniotic membrane used in this manner can be applied as a therapy for superficial corneal ulcers in the beginning phases of the repair process.

Glucosamine and chondroitin sulfate in the repair of osteochondral defects in dogs - clinical-radiographic analysis

Among the proposed treatments to repair lesions of degenerative joint disease (DJD), chondroprotective nutraceuticals composed by glucosamine and chondroitin sulfate are a non-invasive theraphy with properties that favors the health of the cartilage. Although used in human, it is also available for veterinary use with administration in the form of nutritional supplement independent of prescription, since they have registry only in the Inspection Service, which does not require safety and efficacy testing. The lack of such tests to prove efficacy and safety of veterinary medicines required by the Ministry of Agriculture and the lack of scientific studies proving its benefits raises doubts about the efficiency of the concentrations of such active substances. In this context, the objective of this study was to evaluate the efficacy of a veterinary chondroprotective nutraceutical based on chondroitin sulfate and glucosamine in the repair of osteochondral defects in lateral femoral condyle of 48 dogs, through clinical and radiographic analysis. The animals were divided into treatment group (TG) and control group (CG), so that only the TG received the nutraceutical every 24 hours at the rate recommended by the manufacturer. The results of the four treatment times (15, 30, 60 and 90 days) showed that the chondroprotective nutraceutical, in the rate, formulation and administration at the times used, did not improve clinical signs and radiologically did not influence in the repair process of the defects, since the treated and control groups showed similar radiographic findings at the end of the treatments.

Economic analysis of surgical treatment of hip fracture in older adults

OBJECTIVE To analyze the incremental cost-utility ratio for the surgical treatment of hip fracture in older patients.METHODS This was a retrospective cohort study of a systematic sample of patients who underwent surgery for hip fracture at a central hospital of a macro-region in the state of Minas Gerais, Southeastern Brazil between January 1, 2009 and December 31, 2011. A decision tree creation was analyzed considering the direct medical costs. The study followed the healthcare provider’s perspective and had a one-year time horizon. Effectiveness was measured by the time elapsed between trauma and surgery after dividing the patients into early and late surgery groups. The utility was obtained in a cross-sectional and indirect manner using the EuroQOL 5 Dimensions generic questionnaire transformed into cardinal numbers using the national regulations established by the Center for the Development and Regional Planning of the State of Minas Gerais. The sample included 110 patients, 27 of whom were allocated in the early surgery group and 83 in the late surgery group. The groups were stratified by age, gender, type of fracture, type of surgery, and anesthetic risk.RESULTS The direct medical cost presented a statistically significant increase among patients in the late surgery group (p < 0.005), mainly because of ward costs (p < 0.001). In-hospital mortality was higher in the late surgery group (7.4% versus 16.9%). The decision tree demonstrated the dominance of the early surgery strategy over the late surgery strategy: R$9,854.34 (USD4,387.17) versus R$26,754.56 (USD11,911.03) per quality-adjusted life year. The sensitivity test with extreme values proved the robustness of the results.CONCLUSIONS After controlling for confounding variables, the strategy of early surgery for hip fracture in the older adults was proven to be dominant, because it presented a lower cost and better results than late surgery.

Readmission of older patients after hospital discharge for hip fracture: a multilevel approach

ABSTRACT OBJECTIVE To identify individual and hospital characteristics associated with the risk of readmission in older inpatients for proximal femoral fracture in the period of 90 days after discharge. METHODS Deaths and readmissions were obtained by a linkage of databases of the Hospital Information System of the Unified Health System and the System of Information on Mortality of the city of Rio de Janeiro from 2008 to 2011. The population of 3,405 individuals aged 60 or older, with non-elective hospitalization for proximal femoral fracture was followed for 90 days after discharge. Cox multilevel model was used for discharge time until readmission, and the characteristics of the patients were used on the first level and the characteristics of the hospitals on the second level. RESULTS The risk of readmission was higher for men (hazard ratio [HR] = 1.37; 95%CI 1.08–1.73), individuals more than 79 years old (HR = 1.45; 95%CI 1.06–1.98), patients who were hospitalized for more than two weeks (HR = 1.33; 95%CI 1.06-1.67), and for those who underwent arthroplasty when compared with the ones who underwent osteosynthesis (HR = 0.57; 95%CI 0.41–0.79). Besides, patients admitted to state hospitals had lower risk for readmission when compared with inpatients in municipal (HR = 1.71; 95%CI 1.09–2.68) and federal hospitals (HR = 1.81; 95%CI 1.00–3.27). The random effect of the hospitals in the adjusted model remained statistically significant (p < 0.05). CONCLUSIONS Hospitals have complex structures that reflect in the quality of care. Thus, we propose that future studies may include these complexities and the severity of the patients in the analysis of the data, also considering the correlation between readmission and mortality to reduce biases.

The Stoppa procedure in inguinal hernia repair: to drain or not to drain

OBJECTIVE: The objective of this study is to evaluate the benefits of drainage in the Stoppa procedure for inguinal repair. PATIENTS AND METHODS: The use of a suction drain was randomized at the end of the surgical intervention in 26 male patients undergoing inguinal hernia repair, divided into 2 groups: Group A, 12 patients undergoing drainage, and group B, 14 patients not undergoing drainage. On the second postoperative day, all patients underwent abdominal pelvic computed tomography scan examination to detect the presence of abdominal fluid collection. RESULTS: In group A, no patient developed fluid collection in the preperitoneal space, and 1 patient presented with an abscess in the preperitoneal space on the 15th postoperative day. In group B, 12 patients presented with fluid collections in the preperitoneal space on computed tomography scan evaluation. However, only 3 patients presented minor complications. None of the patients developed a major complication. CONCLUSION: The use of suction drainage with the Stoppa procedure does not provide any benefit.

Myocardial repair with long-term and low-dose administration of a nitric oxide synthesis inhibitor. Myofibroblasts, type III collagen and fibronectin

OBJECTIVE: To study the healing process of the myocardium in hypertensive rats undergoing inhibition of nitric oxide synthesis. METHODS: Two groups of animals were studied: one received L-NAME, 12mg/kg/day, and the other was a control group. The presence of type III collagen, fibronectin, and alpha-smooth muscle actin-positive cells was assessed by immunohistochemistry. RESULTS: Fibronectin was seen in both early and late lesions, while type III collagen was seen mainly in areas of incomplete healing, situated among myocytes and around the intramyocardial branches of the coronary arteries. Areas representing early and late lesions showed a population of spindle-shaped cells. Immunohistochemistry showed that these cells were positive for alpha-smooth muscle actin. CONCLUSION: In the myocardium of hypertensive rats, the alpha-smooth muscle actin-positive cells are related to the accumulation of type III collagen and fibronectin in the areas of myocardial damage.

Mitral valve repair. Quadrangular resection of the posterior leaflet in patients with myxomatous degeneration

OBJECTIVE - To analyze the immediate and late results of mitral valve repair with quadrangular resection of the posterior leaflet without the use of a prosthetic ring annuloplasty. METHODS - Using this technique, 118 patients with mitral valve prolapse who underwent mitral repair from January '84 through December '96 were studied. Age ranged from 30 to 86 (mean = 59.1±11.8) years and 62.7% were males. An associated surgery was performed in 22% of the patients, and coronary artery bypass graft was the most frequently performed surgery (15 patients - 12.7%). In 20 (16.9%) patients other associated techniques of mitral valve repair were used and shortening of elongated chordae tendineae was the most frequent one (6 patients). RESULTS - Immediate mortality was 0.9% (one patient). Long-term rates for thromboembolism, endocarditis, re-operation and death in the late postoperative period were 0.4%, 0.4%, 1.7% and 2.2% patients/year, respectively. The actuarial curve of survival was 83.8±8.6% over 12 years; survival free from re-operation was 91.8±4.3%, free from endocarditis was 99.2±0.8% and free from thromboembolism was 99.2±0.8%. In the late postoperative period, 93.8% of the patients were in functional class 1 (NYHA), with a complete follow-up in 89.7% of the patients. CONCLUSION - Patients with mitral valve prolapse who undergo mitral valve repair using this technique have a satisfactory prognosis over 12 years.

Mitral valve repair with a malleable bovine pericardium ring

OBJECTIVE: To describe a surgical procedure utilizing a malleable bovine pericardium ring in mitral valve repair and clinical and echodopplercadiographic results. METHODS: Thirty-two (25 female and 7 male) patients, aged between 9 and 66 (M=36.4±17.2) years, were studied over a 16-month period, with 100% follow-up. In 23 (72%) of the patients, the mitral approach was the only one applied; 9 patients underwent associated operations. The technique applied consisted of measuring the perimeter of the anterior leaflet and implanting, according to this measurement, a flexible bovine pericardium prosthesis for reinforcement and conformation of the posterior mitral annulus, reducing it to the perimeter of the anterior leaflet with adjustment of the valve apparatus. RESULTS: The patient survival ratio was 93.8%, with 2 (6.2%) fatal outcomes, one from unknown causes, the other due to left ventricular failure. Only one reoperation was performed. On echodopplercardiography, 88% of the patients had functional recovery of the mitral valve (50% without and 38% with mild insufficiency and no hemodynamic repercussions). Of four (12%) of the remaining patients, 6% had moderate and 6% had seigre insufficiency. Twenty-eight percent of class II patients and 72% of class III patients passed into classes I (65%), II (32%), and III (3%), according to NYHA classification criteria. CONCLUSION: Being flexible, the bovine pericardium ring fit perfectly into the valve annulus, taking into account its geometry and contractility. Valve repair was shown to be reproducible, demonstrating significant advantages during patient evolution, which did not require anticoagulation measures.

Remission of heart failure through endoluminal repair of femoral arteriovenous fistula with the use of a covered stent

We report the case of a 21-year-old male with high-output heart failure due to a femoral arteriovenous fistula caused by a firearm wound. A new balloon expandable stent covered with polytetrafluorethylene was implanted in the artery to occlude the arteriovenous fistula. The fistula was immediately occluded and the artery remained patent. On the following day, the patient felt much better, with no symptoms of heart failure. Additional follow-up is required to assure the usefulness of this less invasive procedure in the treatment of arteriovenous fistulas.

Surgical repair of a pseudoaneurysm of the ascending aorta after aortic valve replacement

We report the case of a patient with a pseudoaneurysm of the ascending aortic clinically diagnosed 5 months after surgical replacement of the aortic valve. Diagnosis was confirmed with the aid of two-dimensional echocardiography and helicoidal angiotomography. The corrective surgery, which consisted of a reinforced suture of the communication with the ascending aorta after opening and aspiration of the cavity of the pseudoaneurysm, was successfully performed through a complete sternotomy using extracorporeal circulation, femorofemoral cannulation, and moderate hypothermia, with no aortic clamping.

Repair of an Atherosclerotic Coronary Artery Aneurysm by Implantation of a Coronary Covered Stent

An atherosclerotic aneurysm of the right coronary artery complicated by a recent myocardial infarction was successfully treated with coronary artery stenting, using a device consisting of 2 stents with a layer of expandable polytetrafluorethylene (PTFE) placed between them. A follow-up angiograph 5 months after the procedure showed sustained initial results.

Late Results of Endoventricular Patch Plasty Repair in Akinetic and Dyskinetic Areas After Acute Myocardial Infarction

OBJECTIVE - To assess the surgical results of endoventricular patch plasty repair in akinetic and dyskinetic left ventricular areas. METHODS - We studied 52 patients who had undergone endoventricular patch plasty repair associated with myocardial revascularization. The preoperative functional class distribution was as follows: class I in 1 (1.9%) patient; class II in 2 (3.8%) patients; class III in 23 (44.2%) patients; and class IV in 26 (50%) patients. RESULTS - The immediate mortality rate was 7.6% (4 patients). The clinical outcome of 44 patients followed up within a mean postoperative time of 29±25 months was as follows: class I in 33 (75%) patients; class II in 7 (15.9%) patients; class III in 2 (4.5%) patients; and class IV in 2 (4.5%) patients. Comparison between pre- and postoperative catheterization in 21 patients showed that the ejection fraction increased from 46.3% to 51.3% (p=0. 17); the left ventricular systolic volume decreased from 76.4 mL to 57.5 mL, (p=0.078); and the left ventricular diastolic volume decreased from 141.2 mL to 105.8 mL (p=0.0 73). These findings showed the tendency toward improvement, but with nonsignificant results. CONCLUSION - The technique proved to be effective, to have a low mortality rate, to cause significant clinical improvement, an increase in ejection fraction, and a reduction in left ventricular volumes.

Right ventricular structure and function as possible determinants of surgical outcome 30 years after repair of tetralogy of Fallot

OBJECTIVE: To identify the variables that may be involved in the persistence of symptoms (functional class II, III, or IV vs. I) in patients being followed up for 30 years after surgical repair of tetralogy of Fallot. METHODS: Fifty-three patients (27 women), who underwent corrective surgery for tetralogy of Fallot between 1960 and 1970, were studied. Their ages ranged from 7 months to 26 years. At the end of follow-up, 13 patients were asymptomatic and the remaining were in functional class II (N=24), III (N=15), and IV (N=1). To differentiate asymptomatic from symptomatic patients, the following variables were analyzed: age at surgery, need for widening the pulmonary ring and trunk, need for a second (2nd OP) or 3rd operation, residual defect of the interventricular septum, residual regurgitation of the pulmonary valve, systolic gradient through the right ventricular outflow tract, right ventricular dilation or hypertrophy (RVH), cardiothoracic index (CTI), right and left ventricular ejection fraction (RVEF/LVEF), and arrhythmias. RESULTS: The univariate analysis showed an association between the presence of symptoms and the 2nd OP (P=0.03), an increase in the CTI (P=0.0001), moderate to severe RVH (P=0.002), and dilation (P=0.0003). In the logistic regression model, the combination of the 2nd OP (P=0.008), the RVH (P=0.002), and the reduction in RVEF (P=0.01) determined the presence of symptoms. CONCLUSION: Despite the surgical treatment, right ventricular remodeling and performance were the major determinants in the late follow-up of tetralogy of Fallot.