Radial head prosthesis with a mobile head

Radial head replacement is a useful method in the treatment of comminuted radial head fractures. Because such injuries are a common clinical problem and many complications have been reported after radial head replacements, a new radial head prosthesis is proposed. This new design, based on the shape-dimensional identification of the radial head, consists of two parts. The head, made of ultra-high molecular weight polyethylene, is articulated with a Vitallium stem. A series of functional quality and strength tests were conducted on this new prosthetic design. The implant was also examined via the finite element method. General preclinical investigations of clinical cases show that this prosthesis is a very promising design.     

Insertion of Self-Expandable Nitinol Stents Without Previous Balloon Angioplasty Reduces Restenosis Compared with PTA Prior to Stenting

PURPOSE: To compare the development of intimal hyperplasia after deployment of a self-expanding nitinol stent with and without previous percutaneous transluminal balloon angioplasty (PTA), with the results after PTA alone. METHODS: In nine healthy pigs, the iliac arteries were divided into three groups: group 1 (n = 6 arteries) was treated with PTA; group 2 n = 6) with insertion of self-expanding stents after PTA; and group 3 (n = 6) with stent insertion without previous PTA. After 8 weeks the vessels were examined with intravascular ultrasonography, histologic examination and morphometric analysis. RESULTS: Although the injury index in group 1 (0.17 +/- 0.57) was lower (p <0.05) than in group 2 (0.26 +/- 0.06) and group 3 (0.26 +/- 0.08), PTA-treated arteries showed significantly (p <0.05) reduced mean luminal gain (0.53 +/- 2.84) compared with arteries treated with PTA prior to stenting (2.58 +/- 1.38) and compared with stenting alone (4.65 +/- 5.34). Stenting after PTA resulted in a higher (p <0.05) restenosis index (2.63 +/- 1.06) compared with stenting without PTA (1.35 +/- 0.59). Group 2 also had a significantly thicker intima p <0.05) and 83% and 74% higher intima/media ratio (p <0.05) compared with groups 1 and 3, respectively. CONCLUSION: Insertion of a self-expandable nitinol stent without previous PTA results in less intimal hyperplasia than if PTA is performed prior to stenting, suggesting that direct stenting can be used in angioplasty sessions with a favorable outcome.     

Post-stenting intravascular brachytherapy trials on hypercholesterolemic rabbits using 32P liquid sources: implications for prevention of in-stent restenosis

PURPOSE: Liquid sources of radiation delivered in angioplasty balloons may be a convenient self-centering device used for prevention of in-stent restenosis. To test the effectiveness of this method an intravascular brachytherapy study was performed using 32P liquid sources in an animal model. METHODS: The radial dose distribution around angioplasty balloons filled with solutions of Na 2H 32PO 4 was calibrated by thermoluminescence dosimetry. The animal experiments were performed in rabbits with induced hypercholesterolemia. The balloons containing 32P were introduced into iliac arteries immediately after stent implantation. Estimated 7-49 Gy doses required 30-100 min irradiations. Radiation effects were evaluated by comparing the thickness of various components of the artery wall. RESULTS: Doses of 7, 12, 16 or 49 Gy on the internal artery surface required 30-100 min of irradiation. The dose of 49 Gy at "zero" distance corresponding to 16 Gy at 1.0 mm from the balloon surface reduced hypertrophy in every layer of the arterial wall: in the intima the cross-sectional areas were 0.13 versus 0.91 mm 2, in the media were 0.5 versus 0.46 mm 2 and in the adventitia were 0.04 versus 0.3 mm 2 (p <0.05). A dose of 7 Gy at the balloon surface produced adverse irradiation effects: the intimal area of the artery was 2.087 versus 0.857 mm 2, the medial area was 0.59 versus 0.282 mm 2 and the adventitial area was 0.033 versus 0.209 mm 2 in treated and control arteries, respectively. CONCLUSION: Application of a 49 Gy irradiation dose to the internal arterial surface effectively prevented in-stent restenosis.     

Changes in the distribution of hepatic arterial blood flow following TIPS with uncovered stent and stent-graft: an experimental study

Purpose: To evaluate changes in distribution of hepatic arterial blood flow in the liver following insertion of an uncovered stent and subsequently a stent-graft in the transjugular intrahepatic portosystemic shunt (TIPS) channel. Methods: The experiments were performed in eight healthy pigs under general anesthesia. In a pilot study in one pig, scintigraphic evaluation of arterial perfusion to the liver was done before and after inflation of a balloon in the right hepatic vein. In the other pigs, outflow from the right liver vein was checked repeatedly by contrast injection through a percutaneously inserted catheter. The arterial perfusion through the liver was examined by scintigraphy, following selective injection of macro-aggregate of 99Tc m-labeled human serum albumin 99Tc m-HSA) into the hepatic artery. This examination was done before and after creation of a TIPS with an uncovered stent and subsequently after insertion of a covered stent-graft into the cranial portion of the shunt channel. Results: In the pilot study changes in the arterial perfusion to the liver were easily detectable by scintigraphy. One pig died during the procedure and another pig was excluded due to dislodgement of the hepatic artery catheter. The inserted covered stent obstructed venous outflow from part of the right liver lobe. The 99Tc m-HSA activity in this part remained unchanged after TIPS creation with an uncovered stent. A reduction in activity was seen after insertion of a stent-graft (p= 0.06). Conclusion: The distribution of the hepatic arterial blood flow is affected by creation of a TIPS with a stent-graft, in the experimental pig model.     

Simultaneous lung resection for cancer and myocardial revascularization without cardiopulmonary bypass (off-pump coronary artery bypass grafting)

Backround

Patients with resectable lung cancer and unstable coronary heart disease are at high risk of postoperative death or severe cardiovascular complications. The aim of this study was to present the early results of radical lung resection for cancer with simultaneous myocardial revascularization on the beating heart (off-pump coronary artery bypass [OPCAB]).

Methods

From 1999 to 2002, thirteen patients (9 men and 4 women, aged 54 to 71 years, mean age 64 yrs) with resectable lung cancer and unstable angina or a recent history of myocardial infarction, were operated on. All of them underwent coronary angiography and neither coronary angioplasty nor stenting were feasible. Eight lobectomies, three pneumonectomies, and two wedge resections were carried out together with aortocoronary graft implantation (mean number of grafts: 1.7 per patient). Myocardial revascularization without cardiopulmonary bypass (OPCAB) preceded the lung resections. The preferred approach to the heart and lung was by sternotomy.

Results

There were no postoperative deaths in this group of patients. The most frequent postoperative complication was prolonged air leakage and one patient required respiratory support for two days. In one patient, significant blood loss was observed with a need for rethoracotomy. Transient supraventricular cardiac arrhythmias occurred in three patients. None of the patients showed evidence of myocardial ischemia after surgery. Patients were followed up for 7 to 36 months. None had acute myocardial infarction. In one patient, who underwent lobectomy, local recurrence was found. In another patient, who underwent pneumonectomy, distant metastases occurred in the third year of observation.

Conclusions

Lung resection carried out simultaneously with OPCAB is a safe and effective method for the treatment of lung cancer and myocardial ischemia.     

Mechanisms of enhanced carbohydrate and lipid metabolism in adipose tissue in uremia.

OBJECTIVE: Hyperlipidemia is a permanent finding in advanced renal failure. It is supposed to be responsible for the accelerated arteriosclerosis and cardiovascular complications observed in patients with that disease. The background is partially determined, however, our knowledge in this matter is not yet satisfactory. METHODS: This study is based on the experimental rat model of chronic renal failure (CRF). Considering white adipose tissue (WAT) lipogenesis upregulation in CRF, along with the determination of acetyl coenzyme A carboxylase (ACC) and fatty acid synthase (FAS) genes expression, we have measured WAT gene expression for sterol regulatory binding protein 1 (SREBP-1) at the level of protein mass and mRNA abundance. Furthermore, we have determined glucose uptake, glucose-to-CO 2 conversion rate, and glucose translocator (GLUT-4) gene expression in WAT. RESULTS: Upregulation of both FAS and ACC gene expression was found in WAT of CRF rats. It was accompanied by WAT SREBP-1 gene overexpression. Moreover, we have observed the increased glucose uptake, glucose to CO 2 conversion rate, and GLUT-4 gene expression in WAT of CRF rats in comparison with controls. CONCLUSION: SREBP-1 gene overexpression may contribute to enhanced lipogenesis upregulation in WAT of CRF rats. It is not excluded that the increased WAT glucose metabolism activity is also induced by this mechanism, although there is no evidence currently to that end. We hypothesize that the increased WAT lipogenesis capacity could be a part of mechanism(s) leading to CRF-induced hyperlipidemia.     

Safety and performance evaluation of a next‐generation antimicrobial dressing in patients with chronic venous leg ulcers

The objective of this study was to investigate the safety and performance of AQUACEL? Ag+ dressing, a wound dressing containing a combination of anti‐biofilm and antimicrobial agents, in the management of chronic wounds. Patients (n = 42) with venous leg ulcers exhibiting signs of clinical infection were treated for 4 weeks with AQUACEL? Ag+ dressing, followed by management with AQUACEL? wound dressings for 4 weeks. Wound progression, wound size, ulcer pain and clinical evolution of the wound were assessed for up to 8 weeks. Adverse events were recorded throughout the study. AQUACEL? Ag+ dressing had an acceptable safety profile, with only one patient discontinuing from the study, because of a non‐treatment‐related adverse event. After 8 weeks, substantial wound improvements were observed: 5 patients (11·9%) had healed ulcers and 32 patients (76·2%) showed improvement in ulcer condition. The mean ulcer size had reduced by 54·5%. Patients reported less pain as the study progressed. Notable improvements were observed in patients with ulcers that were considered to require treatment with systemic antibiotics or topical antimicrobials at baseline (n = 10), with a mean 70·2% reduction in wound area. These data indicate that AQUACEL? Ag+ dressing has an acceptable safety profile in the management of venous leg ulcers that may be impeded by biofilm.     

Limb lengthening in children with osteogenesis imperfecta]

The authors operated on 7 children (5 girls, 2 boys) suffering from osteogenesis imperfecta (oi) type I according to Sillence classification, with lower limbs discrepancy. We elongated 10 segments (7 femurs and 3 tibias). Mean age at operation time was 14.7 years (13-17 years). The mean leg length discrepancy was 9.3 cm (4-18 cm), and shortening of one bone was 6.5 cm (4-9 cm). We used Ilizarov technique twice in tibial lengthening. We used Wagner technique in one tibial elongation and in 7 femur elongation. Except for one tibia, in the remaining cases there was Rush rod inserted intramedullary in the bone being elongated. During tibial elongation we fixed lateral malleous by screw. The osteotomy was performed in proximal metaphysis of the 5 femurs and 3 tibias, and in distal femurs in two cases. The elongation was 1 mm for day, with frequency 4 x 1/4 mm. The mean bone lengthening achieved was 5.5 cm (2-9 cm); the mean lengthening of the limb was 7.9 cm (2-18 cm). The mean time of elongation was 2.8 months (2-5 months). Elongation index was 26 days for 1 cm of lengthening. The mean time of fixator removal was 9.2 months (4-13 months). Healing index was 58 day/1 cm (overall number of days for 1 cm lengthening). The complications occurred in all the patients. Although the risk of numerous complication is high, lower limbs lengthening in children with type I osteogeneis imperfecta is possible to perform and allows equalizing discrepant limbs or, at least reducing the difference.