[Robotic surgery]. / Robotsebészet.

Due to the fast spread of laparoscopic cholecystectomy, surgical procedures have been changed essentially. The new techniques applied for both abdominal and thoracic procedures provided the possibility for minimally invasive access with all its advantages. Robots - originally developed for industrial applications - were retrofitted for laparoscopic procedures. The currently prevailing robot-assisted surgery is ergonomically more advantageous for the surgeon, as well as for the patient through the more precise preparative activity thanks to the regained 3D vision. The gradual decrease of costs of robotic surgical systems and development of new generations of minimally invasive devices may lead to substantial changes in routine surgical procedures.

[New possibilities in practical education of surgery]. / Új lehetoségek a sebészet gyakorlati oktatásában.

The fast spread of laparoscopic surgery in the surgical community also required introduction of new methods of surgical education of these techniques. Training boxes applied for this reason meant a considerable help. The technique of the virtual reality introduced simulation, which is a new possibility in education. For the first time in the history of surgery we can measure medical students' or residents' dexterity and one can get acquainted with a surgical procedure in the form of "serious games". By application of the up-to-date imaging methods we can plan the movements of the surgeon's hand even before the planned operation, practice and repeating can contribute to the safety of the real procedure. Open surgical procedures can be practiced on plastic phantoms mimicking human anatomy and the use of interactive touch devices and e-learning can also contribute to practical education of surgery.

Changes of local and systemic hemorheological properties in intestinal ischemia-reperfusion injury in the rat model.

The aim of this study was to investigate intestinal ischemia-reperfusion and its local and systemic hemorheological relations in the rat. Ten anaesthetized female CD outbred rats were equally divided into 2 experimental groups. (1) Ischemia-reperfusion (I/R): the superior mesenterial artery was clipped for 30 minutes. After removing the clip, 60 minutes of the reperfusion was observed before extermination. Blood samples were taken from the caudal caval vein and from the portal vein before ischemia, 1 minute before and after clip removal, and at the 15th, 30th, and 60th minutes of the reperfusion. (2) Sham operation: median laparotomy and blood sampling were done according to the timing as in I/R group. Hematological parameters, red blood cell aggregation, and deformability were determined. Leukocyte count and mean volume of erythrocytes increased slightly but continuously in portal venous samples during the reperfusion period. Red blood cell aggregation values were higher in portal blood by the end of ischemia, and then became elevated further comparing to the caval venous blood. Both in caval and portal venous samples of I/R group red blood cell deformability significantly worsened during the experimental period compared to its base and Sham group. In portal blood red blood cell deformability was impaired more than in caval vein samples. Histology showed denuded villi, dilated capillaries, and the inflammatory cells were increased after a 30 minutes ischemia. In conclusion, intestinal ischemia-reperfusion causes changes in erythrocyte deformability and aggregation, showing local versus systemic differences in venous blood during the first hour of reperfusion.

Hemorheological, morphological, and oxidative changes during ischemia-reperfusion of latissimus dorsi muscle flaps in a canine model.

Although ischemia-reperfusion (I/R) strongly influences muscle flap survival in reconstructive surgery, there is limited knowledge about its relation to hemorheological parameters and oxidative stress markers in flaps. In the present study we investigated these changes during I/R of latissimus dorsi muscle (LDM) flaps in beagle dogs. In four animals LDM flaps were prepared bilaterally. The right side served as control, while the left side's vascular pedicle was clamped for 60 minutes, and a 60-minute reperfusion was allowed afterward. Blood samples (0.5 ml each) were taken from the pedicle's vein bilaterally before and after the ischemia, and at the 5th, 15th, 30th, 45th, and 60th minutes of the reperfusion, for hematological and erythrocyte aggregation tests. In muscle biopsies, taken before and after I/R, histological investigations and tests for measuring gluthation-peroxidase (GSH-PX) activity, glutathione (GSH) and carbonyl concentrations, and thiobarbituric acid reactive substances (TBARS) content were carried out. In I/R side leukocyte count increased during the reperfusion with a peak at the 30th minute. Hematocrit continuously increased from the 15th minute. In the first 5 minutes of the reperfusion, erythrocyte aggregation increased, than tented to be normalized. In muscle homogenates GSH-PX activity did not change markedly, GSH content slightly decreased, carbonyl and TBARS content increased during reperfusion. A 1-hour ischemia and reperfusion of LDM flaps caused local changes of leukocyte distribution and erythrocyte aggregation, supposedly due to the metabolic and inflammatory reactions. Oxidative damage during reperfusion was also demonstrated.

Morphological, hemodynamical and hemorheological changes of mature artificial saphenous arterio-venous shunts in the rat model.

Artificial femoral arterio-venous (AV) shunts are widely used in rodent models for studying shunt maturation and to optimize various surgical techniques. However, little is known about complex circulatory, microcirculatory, and hemorheological effects of end-to-side saphenous AV shunts. We aimed to study these parameters in mature AV shunts. Studying these questions in CD rats, end-to-side anastomoses were made between the left saphenous artery and vein. On the right-side the nonoperated saphenous vessels served as own control. Furthermore healthy control animals were also investigated. On the 8th to 12th postoperative week microcirculatory and blood flow measurements were performed and blood samples were taken both from the shunt's arterial and venous limbs and from the nonoperated side vessels. Hematological parameters, erythrocyte aggregation, and deformability were determined. The entire shunt and the control vessels were removed for histological examinations. The skin microcirculation on shunt side slightly increased on thigh and decreased on paws versus the nonoperated side. Blood flow measurements made directly on the vessels showed that arterial to venous blood flow rate ratio was 1.59 ± 0.29 on nonoperated side and 1.2 ± 0.13 on the shunt side, and 1.49 ± 0.05 in control animals. Erythrocyte aggregation and deformability worsened on the shunt side. Histologically increased number of smooth muscle elements and connective tissue were found in venous limb of the shunts. The artificial AV shunt between the saphenous artery and vein seems to be a suitable model for further functional-morphological and hemorheological examinations of hemodialysis in various states and diseases.

Cellular and serological changes in the peripheral blood of splenectomized and spleen autotransplanted mice.

BACKGROUND: Our department worked out a modified surgical form of spleen autotransplantation earlier, named "spleen apron method" introduced already into the clinical practice. Recently we tested the immunological changes in a group of patients autotransplanted with about 10-15% of their spleen, what was the at least always implantable amount after the severe splenic injuries. In the current work we aimed at measuring some cellular and serological changes in the peripheral blood of splenectomized and spleen autotransplanted inbred mice two and eight months after the operations in order to get more unambiguous results than that we could obtain in our patients with this technique. MATERIALS AND METHODS: We divided 96 two months old Balb/c female mice into eight groups (n = 12/group). The group of controls, sham operated, splenectomized and autotransplanted animals with two and eight months of survival time after the operations. During the autotransplantation we inserted the same amount of spleen, five slices, "chips," about 10-15% of total mass of spleen, into the greater omentum similarly as it was used in the patients. The concentration of serum proteins were measured by laser nephelometry. The lymphocyte subsets were analyzed by flow cytometry. RESULTS: We found that two months after the operations the number of CD 19+ B-cells increased in the splenectomized but decreased in the autotransplanted animals. Eight months after the operations the number of both CD3+ T and CD19+ B lymphocytes decreased both in the splenectomized and autotransplanted animals compared to the controls and sham operated mice. However, the numbers of T and B cells were slightly but not significantly higher in the autotransplanted than in the splenectomized mice. The serum level of IgM was also decreased in the splenectomized and autotransplanted mice at both time points, however, eight months after the operations the concentration of IgM was significantly higher in the autotransplanted group than in the splenectomized animals. CONCLUSION: The effects of autotransplanted "chips" were different at the various ages of the animals. Additionally, they showed some immunological benefit being quantitatively in accordance to the amount of the transplanted spleen. The elevated level of serum IgM what we found in the autotransplanted mice even with this amount of transplanted spleen eight months after the operations, however, might have the potentially greatest importance compared to splenectomy. These experiments can prove that the attempts for autotransplantation may have real perspectives but their efficacy depends on the amount of the successfully transplanted (saved) mass of spleen.

[Conceptions about microsurgical education. What were 5,460 hours of microsurgical basic education enough for?]. / Gondolatok a mikrosebészeti oktatásról. Mire volt elég az 5460 óra a mikrosebészeti alapoktatásban?

Microsurgical education has an involuting role in the respects both of the effective clinical and successful research work. In Hungarian literature little number of paper can be found that deal with microsurgical educational methods, their results and efficacy. In our department for several decades we have taught the basics of microsurgery at different education levels (graduate and postgraduate), giving the possibility for practicing and developing as well. In this paper we summarize our educational objective and subjective experiences of more than 10 years and 5460 education hours in microsurgical basic courses. Besides the numeric summaries it became clear that the teacher's or tutor's and the candidates' experience and their ability to attain the basics of microsurgery are very important. According to our experience the most effective method is the education in small groups: one tutor and 2-3 candidates can reach the final goal, the basic microsurgical skill.

[Comparative investigation of the hematologic and immunologic effects of splenectomy and spleen autotransplantation in mice]. / Lép autotranszplantáció és lépeltávolítás haematologiai és immunologiai hatásainak összehasonlító vizsgálata egerekben.

We have analysed the hematological and immunological effects of the Furka's spleen chip method of autotransplantation in Balb/c mice two and eight months after splenectomy and autotransplantation. Our results showed that the autotransplants had positive effect on the partial restoration of the damaged elements of both cellular and humoral immunity appearing after splenectomy. However, these beneficial effects may have some dependence of time and species.

[Laparoscopic versus open cholecystectomy: reaction in the liver bed]. / Laparoszkópos versus nyitott cholecystectomia: válaszreakciók a májágyban.

The aim of this study was to compare the incidence, size and localisation of adhesion formation following open and laparoscopic cholecystectomy and to determine immune and foreign body reactions in the liver bed. The experimental animals were divided into two groups: open (OC) versus laparoscopic (LC) cholecystectomy. In the 14th postoperative day the animals were reoperated, types and size of adhesion were measured and tissue samples were extracted from the liver bed for histology. Dense, curtain-like adhesions were formed in OC group. The adhesions developed not only in the operation area but also on other organs. The thread used to ligate the cystic duct and cystic artery caused foreign body reaction, which resulted in granuloma formation. Numerous macrophages, histiocyte giant cell reactions were also present in OC group. Considerable fibrosis was also observed in the majority of the animals. Slender adhesion formation formed after LC. It was mostly detected in the liver bed. Foreign body granulomas around the laparoscopic clips did not develop in the cases. Moderate inflammatory reactions were noticeable. Laparoscopic operative technique is less traumatic. Its advantage over the open technique is lower adhesion rate and better immune function and reaction. This operation technique is less immunosuppressive and development of adhesions is less compared to OC.

[Teaching of microsurgery--in service of research and clinical practice]. / Mikrosebészeti oktatás a kutatás és a klinikai gyakorlat szolgálatában.

We analyse the improving role of teaching microsurgery, the advantages of the microsurgical models in research and clinical practice. We summarize our experience in teaching basic microsurgery according to Furka's model in the last 15 years. The main characteristics of the principles are: activity, synchronism, video assistance, self-control, individualization, analysis. We show the curriculum of the courses for researchers and participants in graduate and postgraduate education, which consists dry-training on models followed by surgical interventions on rats. Summarizing of our practices: to learn the basic microsurgical techniques the participants need endurance, patience, and have to work hard. Effectiveness of the education is most successful if we organize small groups, if one teacher deals with a maximum of two or three candidates.

[Experimental "functional amputate model" in ischemia-reperfusion]. / Kísérletes "funkcionális amputációs modell" lehetosége az ischaemiareperfusio tükrében.

Limb amputation and ischemia-reperfusion (I/R) after trauma is a serious challenge, though there are few laboratory parameters that are available to predict the prognosis. It is even less so when possible adverse effects of preventive cooling may also influence the clinical outcome. We performed an experimental model earlier on mongrel dogs to investigate the local and systemic effects of cooled and non-cooled limb I/R. In this paper we describe the model and summarize the informative laboratory results. In the warm I/R group the femoral vessels were separately clamped for 3 hours, while steel-loop tourniquet for 7 hours was performed under the femoral vessels around the thigh. After ischemia releasing the clamps provided reperfusion for 4 hours then the steel-loop was removed. In the cooled I/R group similar procedure was performed but with cooling by ice bags. Cooled and non-cooled sham-operated groups also were used. Before operations, during the reperfusion and for 5 days blood samples were collected then haematology and chemistry parameters were determined. Blood rheology and certain coagulation factors were significantly different between the cool and non-cool ischemia-reperfusion groups, furthermore, the changes were also significant compared to sham-operated animals, suggesting that these parameters may be useful in the prognosis.

[Can the injured spleen be preserved? Results of 20-year experiments]. / Megmentheto-e a sérült lép? 20 év kutatási eredményei.

Researches of different spleen salvaging techniques have begun in 1986 at our department. The early purpose was to develop new spleen preservation surgical techniques, such as spleen autotransplantation and spleen resection. Besides the morphological and radiological examinations we also performed different investigations including hemorheological, hemostaseological and immunological follow-up of the splenic function. From these parameters changes in red blood cell deformability and peripheral phagocyte activity could indicate the possible complications originated from the reduced splenic function. Recent paper takes a survey of these experiences.

[The role of pneumoperitoneum and the "chimney effect" on the development of port site metastasis. A new experimental animal model using Furka's spleen tissue suspension]. / A pneumoperitoneum és a "kémény effektus" szerepe a port site metastasis kialakulásában. Furka-féle lép suspensióval végzett új állatkísérletes modell.

Following the introduction of laparoscopic cholecystectomy, laparoscopic technology has been applied in many other fields of surgery, including surgery for malignancies, even before prospective, randomised trials were available. Many authors observed development of port site metastases following laparoscopic surgery in malignancies (1-2%). The studies report about the pathomechanism of the development of port site metastasis, some describe the role of pneumoperitoneum. We developed a new model to show the role of pneumoperitoneum and the "chimney effect" on the development of port site metastasis, using a large experimental animal with a suspension of its own spleen tissue. On follow up histology viable spleen tissue was found between the layers of the trocar incisions.

[Intraoperative laser doppler flowmetry of the tissue microcirculation of extraperitoneal transplanted omental flaps on dogs]. / Extraabdominalisan átültetett cseplesz lebeny mikrocirkulációjának intraoperativ vizsgálata laser Doppler flowmetria segítségével kutyán.

The aim of this study was to develop a new method to check of the viability of an extraabdominally transplanted omental flap. We performed free omental transplantation to the left lateral neck region in the frame of a formerly published new esophageal resection series on 5 dogs. Intraoperative laser Doppler flowmetry was performed, before and after isolation, after transplantation, and 14 days after the operation. From the 5 transplanted flaps, 4 survived the transplantation. The flap microcirculation deteriorated immediately after the transplantation, but at the time of re-operation the measurements showed similar microcirculation as control tissues, which proves the viability of the transplanted flaps. In our opinion, in dogs for the intraoperative monitoring of viability and microcirculation of free transplanted omental flaps, laser Doppler flowmetry is a feasible method.

[Kidney neovascularization by the greater omentum after pretreatment with omental angiogenic factor]. / A vese neovascularizatiója a nagycseplesz felhasználásával omentális angiogén faktor elokezeléssel.

BACKGROUND: Several diseases may affect the renal artery and the circulation of the kidney. In these cases alternative blood flow should be secured to preserve renal function. There are experimental methods for this, such as omentonephropexy. In this model the new vessels grow into the kidney from the omentum. METHODS: Thirty mongrel dogs were anaesthetized and operated on. The left kidney was exposed, partially decapsulated, then omental angiogenic factor extractum was placed on the renal surface and the greater omentum was fixed there. After 4 weeks the left renal artery was ligated, and further 4 weeks later the right kidney was removed. Hematology tests were performed, urea, creatinine levels were measured and urine samples were tested after each operations. For statistical analysis Mann-Whitney rank sum and Wilcoxon signed rank tests were used. RESULTS: The survival rate was 20%. Significant elevations were observed in serum creatinine and urea levels after each operation, mostly after the third one and in non-surviving animals. Moderate anaemia was also present. CONCLUSION: The efficacy of the neovascularization presented in this study and the survival rate indicate further investigations are necessary in order to explore the mechanism and the dynamics of the vascularization processes.

[Determination of urinary NAG to detect renal ischemia-reperfusion injury and the protective effect of Allopurinol]. / Ischaemia-reperfusiós vesekárosodás és az Allopurinol védo hatásának kimutatása vizelet NAG követésével.

We analysed the effect of ischemia-reperfusion injury to renal parenchyma after unilateral renal artery clamping using urinary N-acetyl-beta-D-glucosaminidase (NAG) that is a sensitive parameter of early renal tubular injury. In the study 60 mongrel dogs were divided into 3 groups: in the 1st group the left renal artery was clamped for 45 minutes, in the 2nd group Allopurinol was administered before the clamping, the 3rd was the control group, where only laparotomy and closure of the abdomen was performed. Urinary NAG activity referring to urinary creatinine (NAG index) was determined before the operation, at the beginning of the reperfusion, in the 60th and 120th minute of the reperfusion then 1, 2, 3 and 5 days after the operation. The highest NAG indices relating to injury of the proximal tubuli were found at the beginning of the reperfusion, in the 60th and 120th minutes of the reperfusion, then NAG returned to preoperative level in each group. Significantly higher NAG indices were found in the ischemia-reperfusion group compared to the group with Allopurinol pretreatment. Renal ischemia-reperfusion injury and the protective effect of Allopurinol could be detected by lysosomal NAG enzyme. The injury of the tubular function was reversible so it could be a change in tubular function.

[The importance of hemorheological examinations in experimental limb ischemia-reperfusion injuries]. / A haemorheologiai vizsgálatok jelentosége kísérletes végtagi ischaemiareperfusiós károsodások kapcsán.

Rheological properties of the blood are determined by several factors and if they change it may be diagnostic for many diseases. It is well-known that during ischemia and reperfusion different free-radical liberating pathways are inducted besides the local physical and metabolical changes. These processes may harm red blood cells by increasing their rigidity and impairing their deformability. In ischemia-reperfusion models measurements of erythrocyte deformability is important. Characteristic alterations were observed in both rat and dog hind limb ischemia-reperfusion with vascular clamping on femoral vessels for 1 or 3 hours. Erythrocyte deformability was significantly impaired on the postoperative 1st-3rd days. The acute limb ischemia-reperfusion experimental models seem suitable for further in vivo rheological studies.

Influence of moderate and profound hyperventilation on cerebral blood flow, oxygenation and metabolism.

OBJECTIVE: The aim of the present study was to examine the impact of moderate and profound hyperventilation on regional cerebral blood flow (rCBF), oxygenation and metabolism. MATERIALS AND METHODS: Twelve anesthetized pigs were subjected to moderate (mHV) and profound (pHV) hyperventilation (target arterial pO(2): 30 and 20 mmHg, respectively) for 30 min each, after baseline normoventilation (BL) for 1 h. Local cerebral extracellular fluid (ECF) concentrations of glucose, lactate, pyruvate and glutamate as well as brain tissue oxygenation (p(ti)O(2)) were monitored using microdialysis and a Licox oxygen sensor, respectively. In nine pigs, regional cerebral blood flow (rCBF) was also continuously measured via a thermal diffusion system. RESULTS: Both moderate and profound hyperventilation resulted in a significant decrease in rCBF (BL: 37.9+/-4.3 ml/100 g/min; mHV: 29.4+/-3.6 ml/100 g/min; pHV: 23.6+/-4.7 ml/100 g/min; p<0.05) and p(ti)O(2) (BL: 22.7+/-4.1 mmHg; mHV: 18.9+/-4.9 mmHg; pHV: 13.0+/-2.2 mmHg; p<0.05). A p(ti)O(2) decrease below the critical threshold of 10 mmHg was induced in three animals by moderate hyperventilation and in five animals by profound hyperventilation. Furthermore, significant increases in lactate (BL: 1.06+/-0.18 mmol/l; mHV: 1.36+/-0.20 mmol/l; pHV: 1.67+/-0.17 mmol/l; p<0.005), pyruvate (BL: 46.4+/-7.8 micromol/l; mHV: 58.0+/-10.3 micromol/l; pHV: 66.1+/-12.7 micromol/l; p<0.05), and lactate/glucose ratio were observed during hyperventilation. (Data are presented as mean+/-S.E.M.) CONCLUSIONS: Both moderate and profound hyperventilation may result in insufficient regional oxygen supply and anaerobic metabolism, even in the uninjured brain. Therefore, the use of hyperventilation cannot be considered as a safe procedure and should either be avoided or used with extreme caution.

[Investigation of the healing process of invaginated anastomoses in animal experiments]. / Süllyesztett anasztomózisok gyógyulásának vizsgálata állatkísérletekben.

UNLABELLED: The telescopic anastomosis technique is not frequently used method, but its history could have been followed in the surgical literature since the beginning of the XXth century. Authors can use this technique successfully in their clinical practice performing esophago-gastrostomies, esophago-jejunostomies and ileo-colostomies. They would like to show the healing process of these kind of anastomoses in experimental work, using animal subjects, as data regarding this aspect is not found in the literature. The healing process of esophago-gastrostomies, and ileo-colostomies performed on dogs have been examined. CONCLUSIONS: 1. The invaginated esophageal or ileal segment (up to 30 mm length of submerged part) has not suffered from ischaemic damage. 2. The invaginated esophageal or ileal segment has been covered by the mucosa of the stomach or colon. 3. The physical strength of the anastomosis has arised gradually based this on the measured bursting pressure values. 4. The quality of the healing process has not depended on the length of the invaginated esophageal or ileal segment (up to 30 mm length of submerged part).

[Effect of intravenous and intraductal glucocorticosteroids in experimental acute pancreatitis in dogs]. / Glükokortikoszteroid intravénás és intraductalis alkalmazásának hatásai kutyán kísérletesen elóidézett akut pancreatitisben.

We evaluated the effect of systematically and intraductally administered glucocorticosteroid on experimentally induced acute pancreatitis in dogs. We examined histological and macroscopic changes as well as conventional laboratory parameters. We suggest, that low dose intraductal injection of glucocorticosteroid could have protective effect in acute phase of pancreatitis.