Analysis of Morphological and Morphometric Changes in a Parenchymal Tissue after the Radiofrequency Ablation Procedure.

Background and Objectives: Prostate cancer is on the rise in the European Union, and radiofrequency ablation (RFA) is one of the minimally invasive treatment options used for its treatment. Therefore, the aim of this study was to investigate and analyze the effects of RFA on prostate tissues. Materials and Methods: A standard prostate RFA procedure was performed on 13 non-purebred dogs in three sessions: no cooling (NC), cooling with a 0.1% NaCl solution (C.01), and cooling using a 0.9% NaCl solution (C.09). Microtome-cut 2-3 µm sections of prostate samples were stained with hematoxylin and eosin and further examined. Results: A histopathologic evaluation identified four zones of exposure: direct, application, necrosis, and transitional, as the damage on tissues decreased going further from the ablation site. The areas and perimeters of these zones were calculated, and geometric shapes of ablative lesions were evaluated using the quotient formula. Areas and perimeters of prostate tissue lesions in the NC and C.09 sessions were of similar size, whereas those found in C.01 were statistically significantly smaller. Lesions observed in session C.01 were of the most regular geometric shape, while the most irregular ones were found in session C.09. The shapes of lesions closest to the ablation electrode were the most irregular, becoming more regular the further away from the electrode they were. Conclusions: Prostate RFA leads to tissue damage with distinct morphological zones. Notably, the prostate lesions were the smallest and the most regular in shape after RFA procedures using the 0.1% NaCl cooling solution. It can be argued that smaller ablation sites may result in smaller scars, thus allowing for faster tissue healing if the blood flow and innervation at the ablation site are not compromised.

Preoperative Axillary Ultrasound versus Sentinel Lymph Node Biopsy in Patients with Early Breast Cancer.

Background and objectives: With improved diagnostic means of early breast cancer, the percentage of cases with metastasis in axillary lymph nodes has decreased from 50%-75% to 15%-30%. Lymphadenectomy and sentinel lymph node biopsy are not treatment procedures, as they aim at axillary nodal staging in breast cancer. Being surgical interventions, they can lead to various complications. Therefore, recently much attention has been paid to the identification of non-invasive methods for axillary nodal staging. In many countries, ultrasound is a first-line method to evaluate axillary lymph node status. The aim of this study was to evaluate the prognostic value of ultrasound in detecting intact axillary lymph nodes and to assess the accuracy of ultrasound in detecting a heavy nodal disease burden. The additional objective was to evaluate patients' and tumor characteristics leading to false-negative results. Materials and Methods: A total of 227 women with newly diagnosed pT1 breast cancer were included to this prospective study conducted at the Breast Surgery Unit, Clinic of Surgery, Hospital of Lithuanian University of Health Sciences Kauno Klinikos, between May 1, 2016, and May 31, 2018. All patients underwent preoperative axillary ultrasound examination. Ultrasound data were compared with the results of histological examination. The accuracy and true-negative rate of ultrasound were calculated. The reasons of false-negative results were analyzed. Results: Of the 189 patients who had normally appearing axillary lymph nodes on preoperative ultrasound (PAUS-negative), 173 (91.5%) patients were also confirmed to have intact axillary lymph nodes (node-negative) by histological examination after surgery. The accuracy and the negative predictive value of ultrasound examination were 84.1% and 91.5%, respectively. In ≥3 node-positive cases, the accuracy and the negative predictive value increased to 88.7% and 98.3%, respectively. In total, false-negative results were found in 8.5% of the cases (n = 16); in the PAUS-negative group, false-negative results were recorded only in 1.6% of the cases (n = 3). The results of PAUS and pathological examination differed significantly between patients without and with lymphovascular invasion (LV0 vs. LV1, p < 0.001) as well as those showing no human epidermal growth factor receptor 2 (HER2) expression and patients with weakly or strongly expressed HER2 (HER2(0) vs. HER2(1), p = 0.024). Paired comparisons revealed that the true-negative rate was significantly different between the LV0 and LV1 groups (91% vs. 66.7%, p < 0.05), and the false-negative rate was statistically significant different between the HER2(0) and HER2(1) groups (10.5% vs. 1.2%, p < 0.05). Evaluation of other characteristics showed both the groups to be homogenous. Conclusions: Negative axillary ultrasound excluded axillary metastatic disease in 91.5% of the patients. PAUS had an accuracy of 88.7% in detecting a heavy nodal disease burden. With the absence of lymphovascular invasion (LV0), we can rely on PAUS examination that axillary lymph nodes are intact (PAUS-negative), and this patients' group could avoid sentinel lymph node biopsy. Patients without HER2 expression are at a greater likelihood of false-negative results; therefore, the findings of ultrasound that axillary lymph nodes are intact (PAUS-negative results) should be interpreted with caution.

Microcirculatory, mitochondrial, and histological changes following cerebral ischemia in swine.

BACKGROUND: Ischemic brain injury due to stroke and/or cardiac arrest is a major health issue in modern society requiring urgent development of new effective therapies. The aim of this study was to evaluate mitochondrial, microcirculatory, and histological changes in a swine model of global cerebral ischemia. RESULTS: In our model, significant microcirculatory changes, but only negligible histological cell alterations, were observed 3 h after bilateral carotid occlusion, and were more pronounced if the vascular occlusion was combined with systemic hypotension. Analysis of mitochondrial function showed that LEAK respiration (measured in the presence of pyruvate + malate but without ADP) was not affected in any model of global cerebral ischemia in pigs. The OXPHOS capacity with pyruvate + malate as substrates decreased compared with the control levels after bilateral carotid artery occlusion, and bilateral carotid artery occlusion + hypotension by 20% and 79%, respectively, resulting in decreases in the respiratory control index of 14% and 73%, respectively. OXPHOS capacity with succinate as a substrate remained constant after unilateral carotid artery occlusion or bilateral carotid artery occlusion, but decreased by 53% after bilateral carotid artery occlusion and hypotension compared with controls (p < 0.05, n = 3-6). Addition of exogenous cytochrome c to mitochondria isolated from ischemia brains had no effect on respiration in all models used in this study. CONCLUSIONS: We found a decrease in microcirculation and mitochondrial oxidative phosphorylation activity, but insignificant neuronal death, after 3 h ischemia in all our pig models of global cerebral ischemia. Dysfunction of the mitochondrial oxidative phosphorylation system, particularly damage to complex I of the respiratory chain, may be the primary target of the ischemic insult, and occurs before signs of neuronal death can be detected.

Diagnostic Approaches to Adult-Type Diffuse Glial Tumors: Comparative Literature and Clinical Practice Study.

Gliomas are the most frequent intrinsic central nervous system tumors. The new 2021 WHO Classification of Central Nervous System Tumors brought significant changes into the classification of gliomas, that underline the role of molecular diagnostics, with the adult-type diffuse glial tumors now identified primarily by their biomarkers rather than histology. The status of the isocitrate dehydrogenase (IDH) 1 or 2 describes tumors at their molecular level and together with the presence or absence of 1p/19q codeletion are the most important biomarkers used for the classification of adult-type diffuse glial tumors. In recent years terminology has also changed. IDH-mutant, as previously known, is diagnostically used as astrocytoma and IDH-wildtype is used as glioblastoma. A comprehensive understanding of these tumors not only gives patients a more proper treatment and better prognosis but also highlights new difficulties. MR imaging is of the utmost importance for diagnosing and supervising the response to treatment. By monitoring the tumor on followup exams better results can be achieved. Correlations are seen between tumor diagnostic and clinical manifestation and surgical administration, followup care, oncologic treatment, and outcomes. Minimal resection site use of functional imaging (fMRI) and diffusion tensor imaging (DTI) have become indispensable tools in invasive treatment. Perfusion imaging provides insightful information about the vascularity of the tumor, spectroscopy shows metabolic activity, and nuclear medicine imaging displays tumor metabolism. To accommodate better treatment the differentiation of pseudoprogression, pseudoresponse, or radiation necrosis is needed. In this report, we present a literature review of diagnostics of gliomas, the differences in their imaging features, and our radiology's departments accumulated experience concerning gliomas.

Early course of microcirculatory perfusion in eye and digestive tract during hypodynamic sepsis.

INTRODUCTION: The aim of the study was to evaluate and compare the microcirculatory perfusion during experimental sepsis in different potentially available parts of the body, such as sublingual mucosa, conjunctiva of the eye, and mucosa of jejunum and rectum. METHODS: Pigs were randomly assigned to sepsis (n = 9) and sham (n = 4) groups. The sepsis group received a fixed dose of live Escherichia coli infusion over a 1-hour period (1.8 × 10(9)/kg colony-forming units). Animals were observed 5 hours after the start of E. coli infusion. In addition to systemic hemodynamic assessment, we performed conjunctival, sublingual, jejunal, and rectal evaluation of microcirculation by using Sidestream Dark Field (SDF) videomicroscopy at the same time points: at baseline, and at 3 and 5 hours after the start of live E. coli infusion. Assessment of microcirculatory parameters of convective oxygen transport (microvascular flow index (MFI) and proportion of perfused vessels (PPV)), and diffusion distance (perfused vessel density (PVD) and total vessel density (TVD)) was done by using a semiquantitative method. RESULTS: Infusion of E. coli resulted in a hypodynamic state of sepsis associated with low cardiac output and increased systemic vascular resistance despite fluid administration. Significant decreases in MFI and PPV of small vessels were observed in sublingual, conjunctival, jejunal, and rectal locations 3 and 5 hours after the start of E. coli infusion in comparison with baseline variables. Correlation between sublingual and conjunctival (r = 0.80; P = 0.036), sublingual and jejunal (r = 0.80; P = 0.044), and sublingual and rectal (r = 0.79; P = 0.03) MFI was observed 3 hours after onset of sepsis. However, this strong correlation between the sublingual and other regions disappeared 5 hours after the start of E. coli infusion. Overall, the sublingual mucosa exhibited the most-pronounced alterations of microcirculatory flow in comparison with conjunctival, jejunal, and rectal microvasculature (P < 0.05). CONCLUSIONS: In this pig model, a time-dependent correlation exists between sublingual and microvascular beds during the course of a hypodynamic state of sepsis.

Microvascular distribution in the ocular conjunctiva and digestive tract in an experimental setting.

UNLABELLED: Recently improved microcirculatory imaging techniques, such as orthogonal polarization spectral (OPS) and its technical successor sidestream dark field (SDF) imaging, in handheld devices have allowed a direct observation of the microcirculation at the bedside. Usually a cut-off of 20 µm in diameter is used to differentiate small vessels (mainly capillaries) from large vessels (mainly venules) during this technique. We hypothesized that it was possible to measure the small vessels with a considerably smaller inner diameter. MATERIAL AND METHODS: Images of the sublingual, conjunctival, jejunal, and rectal mucosa microcirculation were obtained with SDF videomicroscopy (Microscan®, Microvision Medical, Amsterdam, the Netherlands). Using the validated software, the length and diameter of microvessels were manually traced with a computer-generated line. All vessels were divided into the groups according to the inner diameter. RESULTS: A total of 156 SDF images of the sublingual, ocular conjunctival, jejunal, and rectal mucosa were taken in 13 pigs. The length of microscopic vessels progressively increased with a decrease in the vessel diameter less than 8 mm in all the lodges, such as sublingual (80.6% of total vessel length), ocular conjunctival (76.5% of total vessel length), jejunal (99.8% of total vessel length), and rectal (97.8% of total vessel length), due to capillary network formation. There was no significant difference in the distribution of vessels from 0 to 10 µm in diameter comparing sublingual and eye conjunctival as well as jejunal and rectal mucosa. CONCLUSION: In pigs, small-diameter microscopic vessels (<10 µm) dominated in all the studied lodges (sublingual, ocular conjunctival, jejunal, and rectal mucosa), and this is evidence to establish a new cut-off for capillaries in microcirculatory analysis of SDF imaging in experimental and clinical studies.

The usage of blood components in obstetrics.

Major obstetric hemorrhage remains the leading cause of maternal morbidity and mortality worldwide. Even though blood transfusion may be a life-saving procedure, an inappropriate usage of blood products in obstetric emergencies especially in cases of massive bleeding is associated with increased morbidity and risk of death. Thorough knowledge of the etiology, pathophysiology, and optimal therapeutic options of major obstetric hemorrhage may help to avoid lethal outcomes. There are evidence-based data about some risks related with transfusion of blood components: acute or delayed hemolytic, febrile, allergic reactions, transfusion-related acute lung injury, negative immunomodulative effect, transmission of infectious diseases, dissemination of cancer. This is why the indications for allogeneic blood transfusion are restricted, and new safer methods are being discovered to decrease the requirement for it. Red cell alloimmunization may develop in pregnancy; therefore, all pregnant women should pass screening for irregular antibodies. Antierythrocytic irregular antibodies may occur due to previous pregnancies or allogeneic red blood cell transfusions, and it is important for blood cross-matching in the future. Under certain circumstances, such as complicated maternal history, severe coagulation abnormalities, severe anemia, the preparation of cross-matched blood is necessary. There is evidence of very significant variation in the use of blood products (red cells, platelets, fresh frozen plasma, or cryoprecipitate) among clinicians in various medical institutions, and sometimes indications for transfusion are not correctly motivated. The transfusion of each single blood product must be performed only in case of evaluation of expected effect. The need for blood products and for their combination is necessary to estimate for each patient individually in case of obstetric emergencies either. Indications for transfusion of blood components in obstetrics are presented in order to improve the skills of doctors and to optimize therapeutic options in obstetric emergencies.

Extracorporeal shock wave therapy for the treatment of chronic pelvic pain syndrome.

BACKGROUND: Prostatitis is the most commonly diagnosed disease in men younger than 50 years and accounts for about 8% of all urologists' consultations. OBJECTIVE: After evaluating clinical trials and demonstrating the efficacy of chronic non-bacterial prostatitis treatment, it remains of clinical importance to continue studies on the use of low-energy extracorporeal shock wave therapy (ESWT) in men. MATERIALS AND METHODS: From May 2017 to April 2018, 40 patients with chronic prostatitis (CP) type IIIB/chronic pelvic pain syndrome (CPPS) were enrolled in the study. The patients underwent ESWT once a week for 4 weeks. RESULTS: The mean age of the patients was 47.8 years. A statistically significant improvement in all the parameters, i.e., the International Prostate Symptom Score (IPSS), the visual analogue scale (VAS), National Institutes of Health Chronic Prostatitis Symptom Index (NIH-CPSI), and the International Index of Erectile Function (IIEF), was observed at week 4. The effect of the treatment was maintained during the entire 12-week period. The NIH-CPSI total score showed the best improvement at week 4, but a slight deterioration without a statistically significant change was noticed at week 12. The greatest improvement at week 4 was documented for the NIH-CPSI and IPSS (43% and 37%, respectively). At week 12, an improvement of 52% and 39% was recorded for VAS and IPSS, respectively. CONCLUSIONS: Our findings confirmed the effectiveness and safety of ESWT in resistant cases of CPPS in the short term. ESWT is cost-effective, which takes little time or requires a small amount of staff, and is easily conducted.

Monitoring changes in heart tissue temperature and evaluation of graft function after coronary artery bypass grafting surgery.

Thermography is a relatively new contact-free method used in experimental and clinical studies and in cardiovascular surgery to investigate the myocardium and coronary artery function. Objects of complex study included mongrel dogs and patients with coronary artery disease who underwent cardiac surgery. For active dynamic thermography, we used a thermovision camera "A20V" (FLIR Systems, USA). Our data indicate that both experimental and clinical study performed on beating hearts could be an important approach to interoperation inspection of autovenous graft function. An infrared camera also can be successfully used to determine the extent of ischemic damage to the myocardium, heart, and blood vessels during surgery as a significant prognostic tool for evaluating outcome after cardiac operation.

[Influence of preoperative treatment with aspirin or heparin on platelet function and intensity of postoperative bleeding in early period after coronary artery bypass surgery]. / Aspirino ar heparino, vartojamo iki operacijos, itaka trombocitu funkcijai bei kraujavimo intensyvumui po aortos vainikiniu jungciu operaciju.

OBJECTIVE: The aim of the study was to evaluate influence of preoperative treatment with aspirin or heparin on platelet function and intensity of postoperative blood loss in early period after coronary artery bypass grafting (CABG). MATERIAL AND METHODS: Study involved 75 patients (men) with ischemic heart disease, who underwent CABG. Patients were divided into three groups: aspirin pretreated (I group, n=25), heparin pretreated (II group, n=22) and III group (n=28) had no antiplatelet or anticoagulant pretreatment. At 24 h after surgery all patients started treatment with aspirin (ASS 100, Bayer), which lasted all hospitalization period. We have evaluated preoperative coagulation parameters: activated partial thromboplastin time, international normalized ratio, and fibrinogen level. Also we have compared platelet count, platelet aggregation induced by adenosine diphosphate during preoperative period, at 1 h, 20 h and at 7 day after surgery. RESULTS: Preoperative coagulation parameters were comparable in all groups. Platelet count was also similar. One hour after surgery platelet count remarkably decreased in all groups (p<0.001); at 20 hours after surgery changes remained the same and at 7 day a significant increase was observed in all groups (p<0.001). The lowest rate of preoperative platelet aggregation was found in I group (p<0.05). At 1 hour after surgery platelet aggregation decreased significantly in all groups, particularly in III group (p<0.001). At 20 hours after surgery platelet aggregation had a tendency to reach previous level and increased substantially in all groups. We have found more than 10% increase in platelet aggregation at 7 day compared to 20 hours postoperatively. These changes were observed in 32% (p<0.05), 27.3% (p<0.05) and 35.7% (p<0.001) of patients in the group I, II and III, respectively. Postoperative blood loss was significantly lowest in II group (p<0.01). CONCLUSIONS: Our investigation shows that preoperative treatment with aspirin or heparin had no remarkable influence on dynamics of platelet function in early period after CABG. The least blood loss was observed in patients with heparin pretreatment.

Public Knowledge, Beliefs and Behavior on Antibiotic Use and Self-Medication in Lithuania.

Irrational antibiotic use has led society to antibiotic resistance-a serious health problem worldwide. This study aimed to assess public knowledge, beliefs, and behavior concerning antibiotic use and self-medication in Lithuania. The cross-sectional survey method was processed using a validated questionnaire in different regions of Lithuania. In total, 1005 adults completed the questionnaire and were included in the study. More than half of the respondents (61.1%) had poor knowledge of antibiotics. Almost half of the respondents incorrectly identified antibiotics as being effective either against viral (26.0%) or mixed (bacterial and viral) infections (21.7%). The respondents with lower educational qualifications (OR = 2.515; 95% CI 1.464-4.319; p = 0.001) and those from rural areas (OR = 1.765; 95% CI 1.041-2.991; p = 0.035) were significantly less knowledgeable of antibiotics. There was no significant difference between genders, different age groups, or different parenthood status. The determined level of self-medication with antibiotics was 31.0%. The men (OR = 1.650; 95% CI 1.120-2.430; p = 0.011), the respondents from rural areas (OR = 2.002; 95% CI 1.343-2.985; p = 0.001), and those without children (OR = 2.428; 95% CI 1.477-3.991; p < 0.001) were more likely to use antibiotics in self-medication. Lithuanian residents' knowledge of antibiotics is insufficient. More information about antibiotic use should be provided by physicians and pharmacists. Self-medication with antibiotics is a serious problem in Lithuania and requires considerable attention.

Effects of ischemia-reperfusion and pretreatment with mildronate on rat liver mitochondrial function.

Mildronate (3-(2,2,2-trimethylhydrazinium) propionate), which is mostly used in cardiological practice and is considered an anti-ischemic drug, was designed to inhibit carnitine biosynthesis in order to prevent accumulation of cytotoxic intermediate products of fatty acid beta-oxidation. Recently it was shown that the mitochondrial respiratory chain may also be a target for mildronate action. In this study, we aimed to investigate whether mildronate can protect the liver against a 90-min normothermic ischemia/30-min reperfusion-induced mitochondrial dysfunction. Rats were pre-treated for one or two weeks with mildronate (100 mg/kg/day or 200 mg/kg/day) or Ringer solution and subjected to ischemia/reperfusion.We found that ischemia/reperfusion caused a decrease in mitochondrial State 3 respiration rate and in the respiratory control index (RCI), and an increase in State 2 respiration rate with succinate, glutamate + malate and palmitoyl-L-carnitine + malate. One or two weeks of pre-treatment of rats with different doses of mildronate did not reduce the ischemia/reperfusion-induced decrease in the State 3 respiration rate or RCI; however, a one week pre-treatment slightly diminished the increase in the State 2 respiration rate with glutamate + malate substrates. The leakage of the liver enzymes, aspartate aminotransferase, alanine aminotransferase and lactate dehydrogenase, was similar in both the untreated and pre-treated with mildronate groups. No steatotic livers were observed in any experimental groups after mildronate pre-treatment. In conclusion, 90 min of liver ischemia followed by a 30 min reperfusion has a deleterious effect on rat liver mitochondrial function. Mildronate pre-treatment of rats at doses of 100 or 200 mg/kg/day for one or two weeks did not prevent ischemia/reperfusion-induced mitochondrial dysfunction and liver injury.

Influence of early re-infusion of autologous shed mediastinal blood on clinical outcome after cardiac surgery.

Various strategies have been proposed to decrease allogeneic blood transfusion requirements after cardiac surgery. The aim of the study was to evaluate the efficacy of collected and re-infused autologous shed mediastinal blood on a patient's postoperative course. Ninety patients who underwent heart surgery with cardiopulmonary bypass (CPB) were studied. The patients were divided into two groups: Group 1 (n=41) received the centrifuged autologous shed mediastinal blood collected from the cardiotomy reservoir 4 hours after surgery; in Group 2 (n=49) all shed mediastinal blood was discarded (control group). Haemoglobin (Hb), haematocrit (Hct), C-reactive protein values, and leucocyte count were compared before surgery, at 4 h and 20 h after surgery, and on the fifth postoperative day. We have measured serum procalcitonin (PCT) concentration at 4 h and 20 h after CPB. We assessed drained blood loss within 20 postoperative hours. Leucocyte count, Hb, Hct values, C-reactive protein, and procalcitonin concentration did not differ between the groups before and at 4 h after surgery. Hb, Hct level, and leucocyte count were similar at 20 hours and on the fifth day after surgery. At 20 hours after surgery, an increase of serum PCT concentration (>0.5-2 ng/mL) was more frequent in Group 2 (58.3% vs. 33.3%; p = 0.03). On the fifth postoperative day, C-reactive protein concentration was lower in Group 1 (71.74 +/- 15.23; p <0.01) compared to Group 2 (93.53 +/- 20.3). Postoperative blood loss did not differ between the groups. Requirement for allogeneic blood transfusion was significantly lower in Group 1 (14.6% vs. 38.8%; p < 0.02). Patients in Group 1 developed less infective complications compared with Group 2 (2.4% and 16.3%, respectively; p < 0.05). The length of postoperative in-hospital stay was shorter in Group 1 compared with Group 2 (9.32 +/- 2.55 and 16.45 +/- 6.5, respectively; p < 0.05). We conclude that postoperative re-infusion of autologous red blood cells processed from shed mediastinal blood did not increase bleeding tendency and systemic inflammatory response and was effective in reducing the requirement for allogeneic transfusion, the rate of infective complications and the length of postoperative in-hospital stay.

Influence of aspirin or heparin on platelet function and postoperative blood loss after coronary artery bypass surgery.

The aim of the study was to assess the effect of aspirin or heparin pretreatment on platelet function and bleeding in the early postoperative period after coronary artery bypass grafting (CABG) surgery. Seventy-five male patients with coronary artery disease who underwent CABG with cardiopulmonary bypass (CPB) were studied. The patients were divided into three groups: Group 1 (n=25) included patients receiving aspirin pretreatment, Group 2 (n=22) received heparin pretreatment, and Group 3 (n=28) included patients who received no antiplatelet or anticoagulant pretreatment. Twenty-four hours after surgery, all patients were administered aspirin therapy that was continued throughout their hospitalization period. We assessed the following preoperative blood coagulation indices: activated partial thromboplastin time (aPTT), international normalized ratio (INR), and fibrinogen. We compared platelet count and platelet aggregation induced by adenosinediphosphate (ADP) before surgery, 1 h after surgery, 20 h after surgery and on the seventh postoperative day. We assessed drained blood loss within 20 postoperative hours. Preoperative blood coagulation indices did not differ among the groups. Platelet count was also similar. One hour after surgery, platelet count significantly decreased in all groups (p<0.001), after 20 postoperative hours it did not undergo any marked changes, and on the seventh postoperative day, it significantly increased in all groups (p<0.001). Before surgery, the lowest index of ADP-induced platelet aggregation was found in Group 1 (p<0.05). One hour after surgery, platelet aggregation significantly decreased in all groups, most markedly in Group 3 (p<0.001), yet after 20 h, its restitution tendency and a significant increase in all groups was noted. On the seventh day, a further increase in the statistical mean platelet aggregation value was noted in Groups 2 and 3. Comparison of platelet aggregation after 20 postoperative hours and on the seventh day after surgery revealed a significantly higher than 10% increase of the index in 32% of patients in Group 1 (p<0.05), 27.3% of patients in Group 2 (p<0.05) and in 35.7% of patients in Group 3 (p<0.001). The lowest statistically significant value of postoperative blood loss was noted in Group 2 (p<0.01). Our study has shown that aspirin or heparin pretreatment had no impact on the dynamics of platelet function in the early postoperative period after CABG. The lowest postoperative blood loss was noted in patients pretreated with heparin.

[Changes of heart electrophysiological parameters after destruction of epicardial subplexuses that innervate sinoatrial node]. / Epikardiniu rezginiu, inervuojanciu sinoatrialini mazga, destrukcijos poveikis sirdies elektrofiziologiniams parametrams.

The aims of present study were to verify the topography of the intracardiac nerve subplexuses (INS) by using electrophysiological methods, its relations with sinoatrial (SA) node function and to investigate possibility of selective surgical SA node denervation. Fifteen mongrel dogs of either sex weighing 8 to 15 kg were used for electrophysiological studies. Both cervical vagosympathetic trunks were isolated and crushed by tight ligatures. Nervus subplexuses destructions were performed by cryocoagulation in three zones located around the right superior vena cava: ventral, lateral and dorsal. The sinus rhythm, SA node function recovery time, AV node conductivity, AV node and atrial effective refractory period were measured. Five experiments in each of three zones were performed. Experimental data show that destruction of the epicardial nerves has different effect on electrophysiological parameters. After destruction of the anterior zone of the right atrium the sinus rhythm decreased on an average by 11.6%; SA node function recovery time prolonged by 7.2%; AV node conductivity decreased by 13.1%; AV node effective refractory period prolonged by 12.9% and atrial effective refractory period, by 10.9 %. Measurements of electrophysiological parameters after intravenous injection of atropine sulphate show that sinus rhythm decreased on an average by 23.4%; SA node function recovery time increased by 9.1%; the conductivity of AV node decreased by 10.2%; AV node effective refractory period prolonged by 15.4% and atrial effective refractory period, by 13.2%. After destruction of the intracardiac nerves of the lateral zone, the sinus rhythm decreased by 15.7%; SA node function recovery time increased by 16.3%; AV node conductivity decreased by 8.3%; AV node effective refractory period and atrial effective refractory period prolonged by 11.9% and 10.0%, respectively. After the atropine sulphate intravenous injection, the sinus rhythm decreased on an average by 7.1%, SA node function recovery time prolonged by 7.1%, AV conductivity decreased by 9.1%, AV node effective refractory period increased by 12.4%, and atrial effective refractory period prolonged by 12.5%. After destruction of the nerves in the dorsal zone the changes of electrophysiological parameters were opposite to those obtained after destruction of the nerve tracts in the anterior or lateral zones: the sinus rhythm increased on an average by 4.3%; SA node function recovery time shortened by 8.8%; AV conductivity increased by 9.7%; AV node and atrial effective refractory period decreased by 12.3% and 12.1%, respectively. After intravenous atropine sulphate infusion, sinus rhythm decreased on an average by 8.3%; SA node function recovery time prolonged by 9.6%; AV node conductivity decreased by 5%; AV node and atrial effective refractory period prolonged by 4.2% and 5.2%, respectively. The average changes of electrophysiological parameters before and after INS destruction shows that cryocoagulation of ventral and lateral zones eliminates the effects of sympathetic tone to SA and AV nodal activity. Cryocoagulation of dorsal zone eliminates the effects of nervus vagus to both nodal structures. These findings shows the possibility alter or correct SA node function by making selective surgical SA node denervation.