Defining Standards in Experimental Microsurgical Training: Recommendations of the European Society for Surgical Research (ESSR) and the International Society for Experimental Microsurgery (ISEM).

BACKGROUND: Expectations towards surgeons in modern surgical practice are extremely high with minimal complication rates and maximal patient safety as paramount objectives. Both of these aims are highly dependent on individual technical skills that require sustained, focused, and efficient training outside the clinical environment. At the same time, there is an increasing moral and ethical pressure to reduce the use of animals in research and training, which has fundamentally changed the practice of microsurgical training and research. Various animal models were introduced and widely used during the mid-20th century, the pioneering era of experimental microsurgery. Since then, high numbers of ex vivo training concepts and quality control measures have been proposed, all aiming to reduce the number of animals without compromising quality and outcome of training. SUMMARY: Numerous microsurgical training courses are available worldwide, but there is no general agreement concerning the standardization of microsurgical training. The major aim of this literature review and recommendation is to give an overview of various aspects of microsurgical training. We introduce here the findings of a previous survey-based analysis of microsurgical courses within our network. Basic principles behind microsurgical training (3Rs, good laboratory practice, 3Cs), considerations around various microsurgical training models, as well as several skill assessment tools are discussed. Recommendations are formulated following intense discussions within the European Society for Surgical Research (ESSR) and the International Society for Experimental Microsurgery (ISEM), based on scientific literature as well as on several decades of experience in the field of experimental (micro)surgery and preclinical research, represented by the contributing authors. Key Messages: Although ex vivo models are crucial for the replacement and reduction of live animal use, living animals are still indispensable at every level of training which aims at more than just a basic introduction to microsurgical techniques. Modern, competency-based microsurgical training is multi-level, implementing different objective assessment tools as outcome measures. A clear consensus on fundamental principles of microsurgical training and more active international collaboration for the sake of standardization are urgently needed.

[The spleen in experimental surgery]. / A lép a sebészi kísérletek tükrében.

The injured but functionally intact spleen can be saved with various surgical techniques. Two of these techniques were developed in our department: partial spleen resection by embracing suture line, and spleen autotransplantation by implantation of spleen chips between the sheets of the greater omentum, the so called "spleen-apron" technique. Functional and structural postsurgical follow-up investigations were developed in the last three decades, including comprehensive laboratory tests (hematological, hemostaseological, hemorheological, enzymological, routine chemical, immunological), imaging procedures (abdominal US, scintigraphic methods, SPECT, as well as NanoSPECT/CT in the last years) with morphological analysis (conventional histological, immunohistochemical, electonmicroscopical), as well as the investigation of the role of hemopoetic stem cells. These investigations confirm the viability of spleen autotransplantation. The implanted spleen chips are able to restore the splenic functions partially following remodellation and recolonisation after neovascularisation. It is a critically important process in the prevention of overwhelming post-splenectomy infection and DIC. This paper summarizes the most important principles and the main conclusions of different experimental animal models.

[Hemorheological investigations in experimental surgery]. / A haemorheologiai vizsgálatok kísérletes sebészeti vonatkozásairól.

The hemorheological parameters, such as whole blood viscosity, plasma viscosity, hematocrit, fibrinogen concentration as well as the micro-rheological properties of red blood cells (red blood cell deformability and aggregation) play an important role in tissue perfusion. The alternating hemorheological parameters, which are also inter-related, have important effects in determining hemodynamical properties, as well. The altered hemorheological status has a direct effect on endothelial function by changing shear force profile on the endothelial wall, and impairment of red blood cell deformability and aggregation (presence of rigid red blood cell, and enhanced red blood cell aggregation) slows down microcirculation with disturbing capillary perfusion. In experimental surgery vascular clamping and release cause ischemia-reperfusion, which affect red blood cells in many ways: changes pH level, leads to free-radical release, changes osmolarity and lactate and NO concentrations as well as it causes mechanical trauma. Understanding of these pathophysiological processes and determining the extent of reversible-irreversible changes may help to delineate underlying causes in tissue perfusion and microcirculation better, and develop prophylactic and therapeutic possibilities. The challenges of experimental surgery also include the questions of comparability in different measurement methods, and understanding of interspecies-differences of experimental/laboratory animal models in order to increase the relevance of results in terms of applicability for the original, clinical question.

[Main indicators of educational activity at the Department of Operative Techniques and Surgical Research at the University of Debrecen between 2000-2013]. / A DE OEC Sebészeti Mutéttani Tanszék oktatási tevékenységének fobb mutatói 2000-2013 között.

The authors provide a review about the main parameters of the gradual and postgradual educational activity of the Department of Operative Techniques and Surgical Research between 2000-2013. In this period of time several new subjects and courses have been introduced. The thematics have been widened, and the educational topics underwent a significant change and development: new teaching videos, revised note-books and a new textbook have been prepared through these years. Further, new training models (surgical training models, phantom and biomodels) have also been evolved. The educational activity of the Department was supported significantly several times (financial, contribution, grants) from the University of Debrecen, partner companies, HEFOP and TÁMOP grants. Infrastructural development in conjunction with the above increased the quality of educational standards in gradual and postgradual education, too. All these changes and developments were presented on various professional meetings and published in relevant journals, as part ofinternal quality control.

[Data on liver enzyme and histological changes caused by intermittent clampings of the hepatoduodenal ligament in an experimental model]. / Adatok a ligamentum hepatoduodenale idoleges leszorítása által kiváltott májenzim- és szövettani változások vizsgálatához kísérletes modellen.

Intermittent compression of the structures of the hepatoduodenal ligament, is often performed during liver surgery. As a result, changes in hepatic blood supply and consequent reperfusion induced tissue damages will develop. Ischemia-reperfusion injury, which occur in local and distant regions, influence outcome of hepatic surgery, and it is in close correlation with the duration of hypoxia during the intervention. In animal model the effect of Baron/Pringle manoeuvre was investigated in terms of changes in liver function tests and histology. The study was carried out on 12 Beagle dogs, clamping of the hepatoduodenal ligament for 3×15 minutes then half an hour reperfusion was performed followed by blood and tissue sampling. Significant histological changes were observed both in the liver as well as the small intestine. In terms of liver function changes, GPT elevation occurred the earliest, GOT and LDH were also increased at the end of the 30 minutes reperfusion. In this animal model, the third 15 minutes compression turned out to be too long. Elevation in GPT levels was the most sensitive marker.

[Trocar site herniation (TSH) following laparoscopic cholecystectomy: incidence, pathogenesis, and prevention -- animal study]. / A trokárok helyén kialakult hasfali sérvekrol (Trocar Site Hernia) laparoscopos cholecystectomia után: incidencia és megelozés -- állatkísérletes tanulmány.

INTRODUCTION: In 1968 R. E. Fear first reported a trocar site hernia (TSH) in his large series on laparoscopy. Currently, the incidence of TSH is estimated to be 0.65-2.80%. Ports ≥10-mm are usually closed, but ports of the 5-mm trocars are always left open, which may lead to herniation. MATERIAL AND METHODS: Authors guided teaching courses for hands-on animal laparoscopic cholecystectomy (LC) operations, where trainees performed LC-s on 60 animals. Two and four weeks following the operations the animals underwent second look laparoscopy to detect adhesion formation. RESULTS: Trocar site herniation was observed, and in 20% of the animals herniation was found. 70% of the hernias were situated in the 5-mm ports and 30% in the 10-mm ports. CONCLUSION: Port sites should be closed to prevent the formation of TSH. Attention should be payed on the closure of 5-mm trocar sites as well.

[Historical data on the Founding of Experimental Surgical Section of the Hungarian Surgical Society]. / Történeti adatok a Magyar Sebész Társaság Kísérletes Sebészeti Szekciójának megalakulásáról1.

Following the establishment of the European Society for Surgical Research - ESSR on February 17, 1966 in Nancy/France. After the Re-establishment of Hungarian Surgical Society the organization of the Experimental Surgical Section of the Hungarian Surgical Society also started in October 1966. By January 25, 1967, there were 134 registered members of the Section. Authors present the organisation's letters with the list of applicants with contemporary documents. The Hungarian Experimental Surgical Section held its first congress on September 29-30, 1967 in Debrecen and Hajdúszoboszló.

[Historical data on the beginning of the education of the subject "Surgical anatomy and operative techniques" at the time of Founding of the institute in Debrecen •]. / Történeti adatok a "Sebészeti anatómia és mutéttan" tantárgy oktatásának kezdetérol a debreceni intézet megalakulása idején •.

On December 1, 1951, the Institutes of Surgical Anatomy and Operative Techniques were founded in Hungary. In the academic year 1951/1952, only lectures were held for the students, in an increased number of hours during the semester, there was no practical opportunity yet due to the structural organization of the institutes. The actual teaching of the subject only started in the academic year 1952/1953 for the fourth year (semester 8-9) in the form of 1 h of lecture and 2 h of practical training per week, for a total of 40 h per semester. In the second semester, the subject was closed by a final examination. Regarding the institute in Debrecen, the authors present the beginning of teaching the subject based on contemporary documents.

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.

Experiences with basic microsurgical training programs and skill assessment methods at the University of Debrecen, Hungary.

During the past decades microsurgical training programs together with skill assessment methods had been developing intensively worldwide. Concerning the teaching of basic techniques at various levels, we aimed to summarize the education program types and experiences at our department, in order to define the way of continuity. All in the hope that this summary might contain useful information for other educators as well. About 50 years ago, in the late 1960s, microsurgical basic education had been established in Debrecen. Since the 1990s multilevel education programs have been developed, starting in undergraduate years up to the postgraduate training, residency and continuous medical education programs. In the last three decades about 2,300 participants completed courses, including over 470 residents. The ones who already succeeded microsurgical course as medical students, during residency program could reach better results and skill development. Concluding thoughts, the traditional methods and special experiences are highly important in microsurgical education. The necessary duration and individual training approach are emphasized. Standardization (self and international), comparability, accessibility, providing milestones of microsurgical skills are key factors. Proper feedback and skill assessment (experiences, internationally recognized scores, or combinations) are indispensable, but have to be fitted to the characteristic elements of the course.

How does practice improve the skills of medical students during consecutive training courses?

PURPOSE:: To follow-up the development of medical students in taking a stitch using two different bench models, and to assess their performance with regards to gender, handedness, prior recreational activities and interest in surgery. METHODS:: The study was performed during the compulsory basic (n=152) and the consecutive elective course (n=27). Students took simple interrupted stitches into synthetic and biopreprate models in the classroom and in the operating room. The time needed for that was measured and the quality was scored, using an OSATS (Objective Structured Assessment of Technical Skill) checklist that had been adapted to our training programs. RESULTS:: Students' performance improved both in time and quality during classes, over the course and compared basic to the elective course, too. No significant difference was found in relation to gender and handedness but certain recreational activities and special interest in surgery led to better results. Operating room environment had a slight negative effect on students' performance. CONCLUSION:: The study could provide objective skill assessment, monitoring has revealed deficiencies and influencing factors. Objective feedback, valid and reliable assessment is important in teaching surgical skills. In addition it may contribute to higher surgical safety later on in the clinical practice.

Changes of red blood cell aggregation parameters in a long-term follow-up of splenectomy, spleen-autotransplantation and partial or subtotal spleen resections in a canine model.

BACKGROUND: Decrease or loss in splenic filtration function may influence the hemorheological state. OBJECTIVE: To follow-up the long-term effects of splenectomy, spleen autotransplantation and spleen resections on red blood cell aggregation in a canine model. METHODS: Beagle dogs were subjected to control (n = 6), splenectomy (SE, n = 4), spleen autotransplantation (AU, Furka's spleen-chip method, n = 8) or partial and subtotal spleen resection (n = 4/each) groups, and followed-up for 18 postoperative (p.o.) months. Erythrocyte aggregation was determined in parallel by light-transmittance aggregometry (Myrenne MA-1 aggregometer) and syllectometry (LoRRca). RESULTS: Erythrocyte aggregation decreased three months after splenectomy, with lower aggregation index and elongated aggregation time. It was more or less associated with relatively lower hematocrit and fibrinogen concentration. However, in autotransplantated animals a relatively higher fibrinogen did not increase the aggregation markedly. Spleen resection resulted in the most controversial red blood cell aggregation findings, and it seems, that the degree of the resection is an influencing factor. CONCLUSIONS: Splenectomy alters erythrocyte aggregation, spleen autotransplantation can be useful to preserve filtration function. However, the degree of restoration shows individual differences with a kind of 'functional periodicity'. Spleen resection controversially influences erythrocyte aggregation parameters. The subtotal resection is supposed to be worse than spleen autotransplantation.

Comparative erythrocyte deformability investigations by filtrometry, slit-flow and rotational ektacytometry in a long-term follow-up animal study on splenectomy and different spleen preserving operative techniques: Partial or subtotal spleen resection and spleen autotransplantation.

BACKGROUND: Partial or subtotal spleen resection or spleen autotransplantation can partly preserve/restore the splenic filtration function, as previous studies demonstrated. OBJECTIVE: For better evaluation and follow-up of the various spleen-preserving operative techniques' effectiveness versus splenectomy, a composite methodological approach was applied in a canine experimental model. METHODS: Beagle dogs were subjected to control (n = 6), splenectomy (SE, n = 4), partial and subtotal spleen resection (n = 4/each) or spleen autotransplantation groups (AU, Furka's spleen-chip method, n = 8). The follow-up period was 18 postoperative (p.o.) months. Erythrocyte deformability was determined in parallel by bulk filtrometry (Carat FT-1 filtrometer), slit-flow ektacytometry (RheoScan D-200) and rotational ektacytometry (LoRRca MaxSis Osmoscan). RESULTS: By filtrometry, relative cell transit time increased in the SE group (mostly in animal Nr. SE-3), showing the highest values on the 3rd, 9th and in 18th p.o. months. Elongation index values decreased in this group (both by slit-flow and rotational ektacytometers). In general, AU and two resection groups' values were lower versus control and higher than in SE. CONCLUSIONS: Forasmuch in the circulation both elongation by shear stress and filtration occur, these various erythrocyte deformability testing methods together may describe better the alterations. Considering the possible complications related to functional asplenic-hyposplenic conditions, individual analysis of cases is highly important.

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.

Allopurinol prevents erythrocyte deformability impairing but not the hematological alterations after limb ischemia-reperfusion in rats.

The measurement of red blood cell deformability provides a possible method for detecting the effect of ischemia-reperfusion on erythrocytes. In our study the effect of 1-h ischemia-reperfusion with or without allopurinol pretreatment on hematological parameters and red blood cell deformability was investigated in a follow-up experiment of 26 male CD outbred rats that were subjected to unilateral hind-limb ischemia by microvascular clips on femoral vessels for 1 h (IR, n = 6), some rats received allopurinol pretreatment under the same conditions (50 mg/kg, AP + IR, n = 8), others were subjected to sham operation (n = 6), and the rest of animals served as control (n = 6). Measurement of erythrocyte deformability using a bulk filtrometer with special setting of cell suspension hematocrit (1%), and determination of hematological parameters were performed daily for one week. In the IR group, relative cell transit time increased significantly on postoperative days 1 and 2, which was not observed in the other groups. Settings for the measurement of erythrocyte deformability by reducing the blood sample volume gave the possibility of monitoring the resulting changes in rats. Mean corpuscular volume and hemoglobin, platelet count, and platelet volume were higher in the IR and AP + IR groups than in the other groups. In summary, short-term ischemia and reperfusion induced lower red blood cell deformability in the early postoperative period, which could be prevented by allopurinol pretreatment.

[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.

Hydrostatic characteristics of the ileocolic valve and intussuscepted nipple valves: an animal model.

The ileocolic valve, in the dog, decelerates the passage of stools and prevents fecal reflux. A loss of anterograde resistance worsens the symptoms of short bowel syndrome. The absence of fecal reflux control enhances the risk of recurrence of Crohn's disease. The aim of the present study was to examine what length of intussusception-like nipple valve (INV) should be constructed in order to restore the hydrostatic characteristics of the normal ileocecal valve. The anterograde and retrograde hydrostatic resistances of INVs of different lengths (4, 5, 6, or 7 cm) were compared with those of the normal ileocolic valve by using a contrast enema and x-ray monitoring in a canine model. It was found that the 4-cm-long INV may be sufficient to achieve an appropriate antireflux efficacy (59.60 +/- 4.26 cm H(2)O) versus the ileocolic valve (25.80 +/- 4.92 cm H(2)O), but this does not furnish an anterograde resistance comparable to that of the normal ileocolic valve (10.70 +/- 1.15 cm H(2)O vs. 21.60 +/- 3.96 cm H(2)O). We found that the appropriate length of the INV with which the anterograde resistance of the ileocolic valve could be attained in our model was between 6 and 7 cm. Thus, the shortest possible constructed INV should be effective in clinical conditions such as Crohn's disease, but the recommended length in short bowel syndrome should be greater than this.