Biomedical subjects

I Mikó

Publications and source records attributed to I Mikó.

At least 19 recordsLinked to original sources

PubMed2006

Adhesion formation with open versus laparoscopic cholecystectomy: an immunologic and histologic study.

BACKGROUND: This randomized study aimed to compare the reaction of the immune system to the process of postoperative adhesion formation after open and laparoscopic cholecystectomy. METHODS: In this study, 20 mongrel dogs were used: 10 each in the laparoscopic and open cholecystectomy groups. Blood and peritoneal lavage samples were taken up to postoperative day 14, followed by second-look laparoscopy and reoperation to detect the rate of adhesion formation. Also, specimens were obtained from the liver bed for histology. RESULTS: In the open cholecystectomy group, the white blood cell count was higher in blood samples and lower in lavage specimens. Adhesion formation was extensive, and the histologic immune reaction was more intensive in the open cholecystectomy group. CONCLUSION: This randomized study proved that laparoscopic cholecystectomy was associated with less immune suppression, less inflammatory reaction, and therefore less adhesion formation than open cholecystectomy.

Animals↗

PubMed2003

Experimental examination of the healing process of telescopic esophageal anastomosis.

The basis of telescopic anastomosis is old, only the practical details of it have changed and improved. The telescopic anastomosis technique is successfully applied in our practice for reconstruction of gastrectomy and esophageal resection. The reason for this study was that data about the healing process of telescopic anastomosis had not been found in the literature. We used four groups of mongrel dogs for our experiments: Group A (n = 3) received 20 mm-long invaginations with a survival time of 7 days; Group B (n = 3) received 10 mm-long invaginations with a survival time of 21 days; Group C (n = 3) received 20 mm-long invaginations with a survival time of 21 days; Group D (n = 3) received 30 mm-long invaginations with a survival time of 21 days. At the end of the above survival times we removed the anastomosing area, measured the bursting pressures and performed morphological and histological examinations. In each case we also performed an anastomosis exactly the same as a completely healed anastomosis and its pressure tolerance was measured (0 day). The pressure tolerance within the anastomosis rises gradually and independently of the length of the invaginated esophageal part. Anastomosis leakage did not occur. The invaginated esophageal part did not suffer any damage. The muscular wall of the intragastric part of the esophagus became covered by the mucosa of the stomach during the healing process and it joined with the esophageal mucosa at the edge of the free end of the esophagus.

Anastomosis, Surgical↗

PubMed2001

The influence of intraoperative complications on adhesion formation during laparoscopic and conventional cholecystectomy in an animal model.

BACKGROUND: The aim of this study was to evaluate the extent of postoperative adhesion formation after laparoscopic and open cholecystectomy. MATERIALS AND METHODS: Qualified surgeons performed 60 experimental laparoscopic cholecystectomies (LC) in dogs with the aim to acquire the laparoscopic technique. To assess the relation between the complications during the operation (bleeding, laceration of the liver bed, or gallbladder perforation) and the formation of adhesions, surviving animals were divided into four groups according to the type of complication occurred. Assessment of the results was made by second-look laparoscopy 4 weeks after LC using the adhesion index (AI; score range, 0-4). The animals then were killed so the extent of adhesion formation could be measured. As a control, open cholecystectomy was performed in 15 dogs without intraoperative complications. The Mann-Whitney rank-sum test and Dunn's method were used for statistical analysis. RESULTS: No adhesion formation or intraoperative complications were registered in the laparoscopic group I. In all the cases wherein bleeding or laceration of the liver bed occurred and was managed with electrocoagulation, adhesions formed. Adhesion formation in these groups was significantly higher than in "ideal LC" or cases of gallbladder perforation alone (p < 0.01). All the animals in the control group developed significantly more adhesions than those in the experimental group (p < 0.05). CONCLUSIONS: It seems that LC has a lower rate of adhesion formation than the conventional open technique. Complications such as bleeding or laceration of the liver bed during LC can enhance adhesion formation. No adhesion formation can be mentioned in relation to gallbladder perforation during LC.

Animals↗

PubMed2001

Basic teaching in microsurgery.

We summarize our 15 years of educational experience in the field of teaching microsurgery. The students can be divided into three groups: (1) medical students, (2) researchers, (3) medical doctors and specialists. Characteristics of our method include the following: activity, synchronism, video-assistance, self-controlling, individualization, analysis. The Furka microsurgical educational method, named after one of the authors, is 20 hours long (five 4-hour sessions). The first lesson allows students to become acquainted with the microsurgical instruments. The next lesson consists of learning the probe of layer-feeling. The third lesson is to learn how to produce stitches under the microscope. The fourth lesson includes arterial anastomosis preparation on fresh arterial pieces of animal origin. The fifth lesson means a quality change from previous classes, as practice is performed on living animals, generally rats. The teaching of microsurgical basics requires both patience and empathy. The teaching process is most successful if one teacher deals with a maximum of two students.

Animals↗

PubMed2001

Spleen autotransplantation in mice: a novel experimental model for immunology study.

The aim of the experimental model to develop a spleen transplant model in mice to study the role of spleen in autoimmune and transplant rejection. After a midline incision, splenectomy was performed. Four tiny segments were cut from the removed spleen and were rinsed at room temperature in physiological salt solution. The greater omentum was lifted and four omental pockets were created; four thin segments were then placed into the "nests," subsequently marked, and fixed using 8-0 suture. The abdomen was then closed. The duration of the survival time was different among the nine groups (n = 3-3). Tissue samples were taken from the marked areas for histological examination stained with hematoxylin and eosin (H&E). H&E staining demonstrated large, well-circumscribed splenic nests with lymphoid zone and red pulp and well-formed trabecules in the spleen. Among the possible applications of this novel model is the ability to study the role of spleen in autoimmune and organ rejection.

Animals↗

PubMed2001

[How do intraoperative complications effect adhesion formation after laparoscopic cholecystectomy: a comparative animal study].

BACKGROUND: The aim of this study was to evaluate the extent of postoperative formation of adhesions following laparoscopic and open cholecystectomy. MATERIAL AND METHODS: 60 experimental laparoscopic cholecystectomies (LC) were performed in dogs by qualified surgeons to learn laparoscopic technique. To assess the relationship between complications occurred during the operation (bleeding, laceration of the liver bed or gallbladder perforation) and the formation of adhesions surviving animals were divided into 4 groups according to the type of complication. We assessed the results during second-look laparoscopy 4 weeks following LC using the adhesion index (AI: 0-4 score). Animals were then sacrificed to measure the extent of adhesions. As a control group open cholecystectomy was performed in 15 dogs without intraoperative complications. Mann-Whitney Rank Sum test and Dunn's Method were used for statistical analysis. RESULTS: No adhesions were observed in the laparoscopic group without intraoperative complications. In all dogs with bleeding or laceration of the liver bed maintained by electrocoagulation, adhesions developed. Formation of adhesion in these groups was significantly higher than in "ideal LC" or in case of gallbladder perforation (P < 0.01). All animals in the control group developed significantly more adhesions compared to the experimental group (p < 0.05). CONCLUSION: LC produces less adhesion compared to conventional open technique. Complications such as bleeding or laceration of the liver bed during LC can increase the formation of adhesions. No formation of adhesions can be related to gallbladder perforation during LC.

Animals↗

PubMed2001

[Data about the early physical reliability of hand-sewn anastomoses in esophagectomy and gastrectomy].

We examined on models the inner pressure tolerance of the most frequently performed single layer anastomoses used in esophagectomies and gastrectomies. The aim was to examine whether interrupted or continuous suture proves safer immediately after the operation. We investigated the difference between sutures involving and not involving the mucosa. The anastomosis models were of organs of hybrid pigs slaughtered in the meet-industry. Atraumatic, 3/0 Biosyn suture material was used. The bursting pressure was measured by insufflating CO2 gas. Its bursting pressure can characterize the inner pressure tolerance of an anastomosis. The circumstances of the experiment, the suture technique and the examination of the bursting pressure were standardized. Our considerations are: 1. The early inner pressure tolerance of an anastomosis does not depend on the condition of the wall. The critical factor is their ability to expand. 2. The inner pressure tolerance of continuous sutures is better than of interrupted ones if the tissues in the suture line show similar degree of dilatation. Optimal conditions are achieved with end-to-end or side-to-side anastomoses of single organs (for example between small bowel and small bowel or colon and colon). 3. Involving the mucosa in the stitches has not influenced early physical suture certainty.

Anastomosis, Surgical↗

PubMed2000

[Various clinical patterns of relapsing polychondritis in six cases].

Relapsing polychondritis is a relatively rare disease characterized by episodic inflammation and progressive destruction of cartilage involving ears, nasal and laryngotracheal cartilage, cardiovascular system and the eyes. The increasing awareness of its clinically distinct has resulted in recognition of at least 550 reported cases. Six cases are reported to demonstrate the wide variety of clinical pattern. The most common features of the disease are auricular and nasal cartilage inflammation and nondeforming arthritis. Ocular symptoms and vasculitis is relatively rare. Two cases of relapsing polychondritis with laryngotracheobronchial manifestations illustrate the severe clinical features of the disease. Relapsing polychondritis may associate with diverse forms of connective tissue disease, such as rheumatoid arthritis. It seems interesting to note the onset in childhood. Treatment has been primarily symptomatic. In situations of mild symptoms, initial treatment is with nonsteroidal antiinflammatory drugs. For cases with serious manifestation, corticosteroids and immunosuppressants are indicated.

Adult↗

PubMed1999

The history and the future of teaching and training of laparoscopic surgery in Hungary.

INTRODUCTION: Laparoscopic biliary surgery was introduced in Hungary at the end of the 1990. A variety of experimental training and teaching courses had been performed in basic techniques and the human field, which was followed by laparoscopic biliary surgery and various advanced fields. AIMS OF THE STUDY: To review the history of teaching and training of laparoscopic surgery in Hungary in both the experimental and the human field, and to draw the consequences of this experience. MATERIAL AND METHODS: In a period of 6 years 704 qualified surgeons received a full hands--on hands experimental training in laparoscopic biliary surgery, laparoscopic advanced surgery, laparoscopic gynaecologic and laparoscopic urology surgery. DISCUSSION: The courses performed in the first and the second phase were of theoretical and practical components. The theoretical knowledge was based with emphasise to the new instruments and equipment, the indications, the new surgical technique. The practical knowledge gave every participant the full time to acquire this new type of surgery. At the end of the courses the successful participants received certificates to shift for training to the human field. Each institution needs to wrestle with issues concerning credentialling in advanced laparoscopic surgery. Like many technical skills, proficiency is maintained through repetition. A philosophy must be developed to determine whether each surgeon will perform this highly specialised type of surgery or whether it will be considered a general skill.

Animals↗

PubMed1999

The judgement of adhesion formation following laparoscopic and conventional cholecystectomy in an animal model.

INTRODUCTION: The development of postoperative adhesions remains an almost inevitable consequence of visceral and gynaecologic surgery, appearing in 50-95% of all patients. Although decreased adhesion formation is one of the accepted advantages of laparoscopic surgery, only a small number of prospective studies have been done to support this claim. AIMS OF THE STUDY: To evaluate the extent of postoperative adhesion formation after laparoscopic and open cholecystectomy. MATERIAL AND METHOD: 60 experimental laparoscopic cholecystectomies (LC) were performed by qualified surgeons in dogs with the aim to acquire the laparoscopic technique. To assess the relation between the complications during the operation (bleeding, injury to the liver substance or gallbladder perforation) and the formation of adhesions, the surviving animals were divided into 4 groups according to the complications occurred. The assessment of the results was made by second--look laparoscopy 4 weeks following LC using the adhesion index. As a control group open cholecystectomy was then performed in 5 dogs without intraoperative complications. RESULTS: No adhesion formation was observed in the groups where no intraoperative complications occurred. In all the cases where bleeding or injury to the liver bed occurred adhesion formation occurred. No adhesion formation was observed in case of gallbladder perforation. In all the animals of the control group adhesion formation was observed. CONCLUSION: It seems that LC has a reduced rate of adhesion formation when compared with the open technique. Complications such as bleeding or injury to the liver substance during LC can enhance adhesion formation. No adhesion formation can be mentioned in relation with gallbladder perforation when the laparoscopic technique is applied.

Adjuvants, Immunologic↗

PubMed1998

Transtracheal electrical stimulation of the spinal cord for intraoperative monitoring of the motor pathway.

Because of the suppressant effects of anesthetic drugs and muscle relaxants on motor responses elicited by either magnetic or electrical transcranial stimulation, intraoperative monitoring of the motor system, and especially monitoring of lower limb function, presents many difficulties. The upper part of the spinal cord was stimulated in 14 anesthetized and relaxed dogs with a cathode attached to the intratracheal tube and an anode fixed above the upper cervical spinous processes. Action potentials evoked by single and serial stimuli were recorded from the exposed right femoral nerve and quadriceps muscle Averaging was necessary for serial stimulations. Reproducible early and late responses to both single and serial stimulations were recorded during regular anesthesia. The origin of the different responses is discussed. Transtracheal stimulation of the spinal cord is easy to perform and the responses recorded from the peripheral nerve or limb muscle are well reproducible in regular anesthesia. The method seems to be appropriate for intraoperative monitoring of the thoracolumbar spine.

Action Potentials↗

PubMed1997

Why the internal mammary artery is an ideal graft for myocardial revascularisation? (an experimental model with omentoplasty).

Ten dogs underwent coronary artery bypass grafting through a right thoracotomy. Free internal mammary artery grafts (IMA) was used for aortocoronary bypass to right coronary artery (RCA) without temporary cardiopulmonary bypass. In upper median laparotomy approach, mobilization and lengthening of the omentum was performed through the retrosternal part of the diaphragm. An epiploic muff was effectuated surrounding the IMA graft. After three months the animals were sacrificed and the grafts folded by omentum were used for microscopical study. The histological evaluation has shown that the omentum has formed a new adventitia around the graft. In the new-formed adventitia, newly formed vessels can be found and these are grouped around the adventitia-media border zone, very rarely penetrating into the external layer of the media. This graft-omentoplasty offer a good experimental model which facilitates to investigate in vivo the blood supply needed by free IMA grafts through the adventitia in experimental conditions. The biological mechanism of angiogenesis in graft wall can be investigate as well.

Animals↗

PubMed1997

Late epigastric incisional hernias following laparoscopic cholecystectomy.

By the introduction of laparoscopic cholecystectomy a new "gold standard" procedure became a routinely performed operation in the field of biliary tract surgery. Thus, the incision related early and late complications are thought to diminish, especially the formation of incisional hernias. Five patients had been referred to our department suffering from chronic incisional hernias following laparoscopic cholecystectomy. All of the hernias were located to the site of the epigastric trocar. The contents of the hernias proved to be omentum. The documentation's of the laparoscopic cholecystectomies revealed the extraction of thick walled gallbladders that contain large stones, and the wounds through which the extraction was performed had not been closed. Taking into consideration the fact of the "Chimney Effect" caused by the desufflation of the pneumoperitoneum at the end of the laparoscopic operation, bowel or omentum can easily escape through the relatively large wound formed during the extraction of the gallbladder, resulting in the formation of incisional hernias. This can be avoided by the complete desufflation and the prompt closure of the wound.

Abdominal Muscles↗

PubMed1997

Results with collagen fleece coated with fibrin glue (TachoComb). A macroscopical and histological experimental study.

Diffuse bleeding from parenchymatous organs at conventional surgery is eliminated with the usual methods coagulation tamponade or styches. We performed experimental series at 9 dogs. After resection of spleen, liver, pancreas and kidney, the bleeding surface was covered by collagen fleece coated with fibrin glue (TachoComb). Postoperatively 7 days, 10 days, 14 days and 28 days we made a relaparotomy. Then the results were analyzed macroscopically and microscopically. In the abdominal cavity neither significant quantity of blood nor greater adhesions were detected. At all cases the fibrin glue was found on place were it was put before. Histologically a perfect wound healing experienced. The fibrin glue (TachoComb) using at diffuse parenchymatous organs' bleeding give a very good results when the wound area is at least 1 cm beyond the immediate wound margin and the fibrin glue is applied onto the wound and pressed on it for 4-5 minutes.

Animals↗

PubMed1997

Comparison between continuous brain tissue measurement and cerebrovenous measurement of pO2, pCO2 and pH in a porcine intracranial pressure model.

Simultaneous oxygen measurements in brain tissue (p(ti)O2) and hemoglobin saturation measurement in cerebrovenous blood in patients after severe head injury have shown different results regarding the comparability of the findings in respect to CPP and ICP. This is contrast to theoretical expectations. The aim of this study was to compare continuous ptiO2 measurement with oxygen partial pressure measurement in sagittal sinus (pO2cv) during simultaneously performance in an animal intracranial pressure model. For continuous measurement we used a newly available multisensor probe. We placed a Paratrend 7 probe (BSL, High Wycombe, UK) in the left frontoparietal white matter and measured ptiO2, pCO2 (ptiCO2) pH (pHti) and temperature (t(ti)) while simultaneously measuring these parameters (pcvO2, pcvCO2, pHcv, tcv) in the sagittal sinus in 9 pigs under general anaesthesia. A fogarty balloon catheter was placed supracerebellar infratentorial and inflated stepwise in order to increase ICP. The baseline levels of pO2ti, pCO2ti und pHti in the non-injured brain tissue showed a more extended heterogeneity compared to the findings in cerebrovenous blood. Both, pO2ti and pO2cv were significant correlated to the CPP decrease. In both measurement compartments pCO2 was inverse correlated to the course of CPP and seems the course of pH mainly to determine. p(ti)O2 as well as p(cv)O2 showed a close correlation to the CPP course and have proven to be qualified to indicate metabolic information about the relation of cerebral blood flow and metabolic cerebral demands. The measurement of CO2 tension in both measurement compartments shows a distinct heterogeneity of the absolute values and the results are only weak correlated to CPP. Metabolic influence on this parameter could not be revealed in the used experimental approach.

Animals↗

PubMed1997

Details of teaching, learning and training in laparoscopic surgery.

The authors discuss the specific details of teaching, learning and training in laparoscopy in 6 main sections, on the basis of their experience gained through basic and advanced courses held for approximately 480 participants at the courses organised at the Department of Experimental Surgery of the University Medical School of Debrecen, between 1989 and 1996. The 6 section cover the following: 1. Why these courses are needed? 2. Who should participate in them? 3. When courses should be held (continuously for beginners, at an appointed time for advanced participants, and chances for training should be provided at any time, according to demand) 4. What should be taught? 5. Where teaching and training should take place (surgical learning/training centres) and 6. What methods of teaching should be used.

Animals↗

PubMed1997

Protection of the renal artery in nephron-sparing surgery. I. Pathomorphological study.

It is necessary to clamp the renal artery for some time in renal surgery to preserve the organ. Not only the renal parenchyma but also the wall of the clamped renal artery may be damaged due to known ischaemic-reperfusion causes. Regional venous renal hypothermia induced by intracellular solutions (Sacks II, Euro-Collins) could provide protection against damage of the vessel wall caused by reperfusion or clamping in our experiments, in cases of clamping for 30 minutes, probably because it also ensured the cooling of the surface of the vessel wall. Similar vasoprotective effect could be achieved by systematic antioxidant treatment (MTDQ-DS) and regional renal hypothermia given in combination. Harmful effects of 45-minute clamping could be best avoided by applying antioxidant treatment alone. While there were no significant morphological changes in the renal arteries the persistent endothelial damage may trigger further complications like renal ischaemic condition.

Animals↗

PubMed1997

Protection of the renal artery in nephron-sparing surgery. II. Arterial contractility investigations.

It has been well known that reperfusion following ischaemia may cause functional and structural damage to not only the organ involved but also the blood vessels supplying that organ. As in organ-sparing renal surgery it is inevitable to clamp the renal artery for some time, it is expected that reperfusion, following the removing of clamping, causes structural changes in the vessel wall which may result in a decrease in arterial function. In our model experiments on animals, the left renal arteries were atraumatically clamped for 30, 45 and 60 minutes. Simultaneously with clamping, perfusion regional renal venous cooling was applied to some of the animals, together with nephrotomy. In some cases cooling was performed in combination with antioxidant treatment. On the 3rd postoperative day renal arteries from both sides were removed, the right, intact ones serving as control. Noradrenaline dose effect curves characterizing vessel contractility were determined to demonstrate functional changes. It was established that cooling the renal artery for only 30 minutes was enough to rule out the damage due to ischaemia-reperfusion. If clamping lasted for 45 minutes, venous cooling of the kidney in combination with antioxidant treatment was necessary to spare arterial function. Clamping for 60 minutes resulted in irreversible/permanent decrease in contractility even if hypothermia and antioxidant treatment were given simultaneously.

Animals↗