Evaluation of resorption and biocompatibility of collagen hemostats in the spinal epidural space

Background contextCollagen hemostats have different characteristics depending on their properties and configuration. In vivo serial evaluation of local reactions because of placement of hemostats in the epidural space has not been reported.PurposeThis study compared the resorption and biocompatibility of two types of collagen hemostats placed in the epidural space.Study designThis in vivo study used experimental animals to evaluate collagen hemostats that were placed in the epidural space.MethodsA ligamentum flavum resection model was created in Japanese white rabbits (n=65). A microfibrillar collagen hemostat (MCH group, n=5), cotton-type collagen hemostat (CCH group, n=5) that was chemically cross-linked, or no hemostat (control group, n=4) was placed in the spinal epidural space. For histologic evaluation, each group was euthanized 1, 2, 4, and 8 weeks postoperatively (PO), and hematoxylin-eosin and immunohistochemical (IHC) staining for inflammatory cytokines (tumor necrosis factor [TNF]-α, interleukin [IL]-6), cyclooxygenase (COX)-2, and macrophages (CD68) was performed. To evaluate exudate accumulation and the degree of inflammation in the epidural space, magnetic resonance imaging at 7.04 T was serially performed in each group (n=3) under anesthesia and sedation.ResultsThe collagen hemostats in both groups were reabsorbed at 4 weeks PO. In the MCH group, there was inflammatory cell infiltration and granuloma formation around the hemostat, TNF-α–positive cells were seen up to 1 week, and IL-6–, COX-2–, and CD68-positive cells were seen at all evaluation times. In the CCH group, no inflammatory cell infiltration around the hemostat was observed, and IHC staining showed no positive cells at 4 weeks PO and later. T2*-weighted MR images showed significantly higher mean signal intensity of the epidural space in the MCH group than in the CCH group but only at 1 week PO (p<.05).ConclusionsResorption of both hemostats was similar. In the MCH group, there was intense tissue inflammation around the hemostatic material, and MR images showed high signal intensity because of exudate accumulation in the epidural space. This indicated a strong foreign-body reaction to the MCH, thus demonstrating a difference in biocompatibility with the CCH.     

Can adenosine triphosphate induce maximal hyperemic response in patients with impaired coronary microcirculation?: comparison of hyperemic response to adenosine triphosphate administered by intravenous and by intracoronary injection using Doppler guide wire

OBJECTIVES: This study compared the hyperemic responses to adenosine triphosphate (ATP) administered by intravenous and by intracoronary injection in patients with impaired coronary microcirculation. METHODS: The hyperemic responses to intravenous and intracoronary administration of ATP in 107 patients (mean age 63 +/- 10 years, 77 males, 30 females) with impaired coronary circulation [including myocardial infarction (n = 68), cardiomyopath (n = 20) and diabetes mellitus (n = 11)] were compared by measurement of coronary flow reserve (CFR) using the Doppler guide wire. Patients with chest pain syndrome were used as the normal controls. The coronary blood flow velocity was measured at rest and during peak hyperemic responses to intravenous infusion (150 micrograms/kg/min) and intracoronary infusion of ATP (50 micrograms in the left coronary artery, 25 micrograms in the right coronary artery). The CFR was calculated as the ratio of averaged peak velocity during hyperemia to baseline averaged peak velocity. RESULTS: The CFR after intravenous administration of ATP (CFRi.v.) was well correlated with CFR by intracoronary administration of ATP(CFRic) (r = 0.77, p < 0.001). However, the CFRi.v. was also inversely correlated with the ratio of CFRic to CFRiv (CFRic/i.v.) (r = -0.36, p < 0.001). There were no relationships between the changes of hemodynamic parameters(blood pressure and heart rate) induced by ATP and CFRic/i.v. A lower CFRi.v. of less than 2.0 provided significantly greater CFRic/i.v. than that of CFRiv greater than 2.0. CONCLUSIONS: The maximal hyperemic response of coronary artery was not always induced by conventional intravenous administration of ATP, especially in patients with lower CFR than 2.0. High dose of intravenous ATP and/or intracoronary ATP should be administered in patients with lower CFR to attain maximum hyperemia in the impaired coronary circulation.     

An operative case of partial anomalous pulmonary venous connection with patent ductus arteriosus and atrial septal defect

The patient was a 28-year-old female who had underwent the operation of the closure of ASD on 7 years old. She administered due to palpitation. Cardiac catheterization revealed PDA, residual ASD, and PAPVC that blood flow from right superior pulmonary vein returned to the high level of SVC (juxsta-inominate vein). Successful repair was performed by intraluminal direct closure for PDA and placing a long patch for ASD and PAPVC.     

Effect of estrogen on liver plasma membrane in rats.

The effect of estrogen on plasma membrane was investigated using the primary cultured rat hepatocytes treated with carbon tetrachloride (CCl4) and the isolated plasma membrane of rat liver. 17 beta-Estradiol (E2), at concentrations of 10(-10) M to 10(-4) M, 10(-8) M to 10(-6) M and 10(-12) M to 10(-4) M, had an inhibitory effect on the CCl4-induced leakage of glutamic oxaloacetic transaminase, glutamic pyruvic transaminase and lactate dehydrogenase, respectively from primary cultured rat hepatocytes. Diethylstilbestrol, which caused inhibition at a dose of 10(-4) M, did not inhibit any enzyme leakage at any further concentrations of 10(-12) M to 10(-6) M. In the isolated plasma membrane of rat liver, Mg(2+)- and Na+,K(+)-adenosine triphosphatase activity was increased by E2 treatment at concentrations of 10(-6) M and 10(-4) M.     

Experimental study of arterial damage induced by anti-cancer drug infusion

In order to clarify the cause of arterial changes after intra-arterial infusion of anti-cancer drugs (AI-AD) experiments were made on the arteries of rabbits. Histopathologic sections, 7 days after AI-AD revealed endothelial damage characterized by pyknosis, hyalinization with edematous change of the intimal layer. Proliferation of the endothelial cells was also observed. The cause of narrowing or occlusion of the arteries was considered to occur with thrombus formation surrounded by the proliferated endothelial cells and this suggested that thrombolytic agents would be effective to prevent these arterial changes.     

Use of ultrasonically activated scalpel for the paced patient —A case report—

A paced patient underwent mitral valve replacement for mitral stenosis using ultrasonically activated scalpel. There were minimum bleeding and no homologous blood transfusion was required. Ultrasonically activated scalpel fid not interfere the pulse generator nor the transesophageal echocardiography. Ultrasonically activated scalpel is useful for the open heart surgery in paced patients.     

LAPAROSCOPIC ABLATION THERAPY FOR HEPATOCELLULAR CARCINOMA

Laparoscopic ablation therapy is an attractive modality for localized hepatocellular carcinoma. It is an optimal treatment in patients with superficial tumors, tumors adjacent to other vital organs, or tumors difficult to access by percutaneous procedure. Laparoscopic access allows for easier detection and more accurate targeting of the tumor compared with percutaneous access and can minimize complications. In addition, this novel technique is favorable in terms of the length of hospital stay and cost‐effectiveness because it is completed in a single session. Characteristics and therapeutic potential of laparoscopic ablation therapy are summarized and compared with other therapeutic modalities in this review.