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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.

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.

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.

The temperature values obtained in renal hypothermia through the venous circulation were biometrically analysed. It was found that there could be even about 4 degrees C temperature differences between the lower and upper poles of the kidney, always as large as 4 degrees C could be elicited in the first five minutes of hypothermia, the lower pole being colder. Similar but smaller differences were observed in ten minutes' hypothermia.

The authors worked out the technique of in situ renal hypothermia in dogs by direct cannulation of the renal vein or through the internal spermatic vein (ovarian vein). The technique is suggested for preventing the ischaemic impairment of the renal parenchyma in operations requiring compression of the renal artery for more than 20 minutes.

Absorbable and non-absorbable suture materials in the renal parenchyma were examined in comparative studies performed on 12 mongrel dogs. Quantitative and qualitative histological studies showed that Dexon was preferable to other absorbable suture materials as opposed to traditional catgut, while Supramide and Polyester had certain advantages over other non-absorbable materials.

Both kidneys of 12 dogs were injured and the wounds were covered with Surgicel which was fixed by means of adhesive. The results were checked by visual inspection and histological tests. The method seems to be suitable for use in appropriate human cases.

The authors have elaborated a sutureless method of closing the wound surface in order to preserve the renal parenchyma. They have used oxydized cellulose net (Surgicel) and tissue adhesive (Histoacryl-N-blau) to hold together the cut surface of the kidney at renal hypothermy (bench surgery) on dogs.

Large nephrotomy incisions made in 15 dogs were closed by sewing up the cavity system with stitches of 5/0 catgut and by sealing the renal parenchyma with tissue adhesive being pinpointed at the opened vessels. The incision was covered with a preparation of oxidized cellulose which was then likewise impregnated with tissue adhesive. This technique was found rapid and convenient and provided for adequate haemostasis. Its essential advantage lies in eliminating the deep through-and-through sutures involving a major loss of functioning renal parenchyma. All substances used were absorbed in due time.

Changes in hemorheological parameters were studied in dogs following unilateral renal artery clamping (45-minute ischemia then reperfusion), with and without preoperative administration of allopurinol. Sham-operated animals were also evaluated. Blood samples were collected preoperatively, at beginning and at 30, 60 and 120 minutes of reperfusion, then on the 1st, 3rd, 5th and 7th days. Filtration properties of erythrocytes (relative cell transit time, RCTT), whole blood and plasma viscosity (WBV, PV), fibrinogen level and hematology parameter were determined. RCTT significantly increased for both ischemic groups at 30 minutes of reperfusion, and remained elevated on the 1st and 2nd postoperative days; these changes were abolished by allopurinol pretreatment. WBV and hematocrit increased on the 1st day, and PV and fibrinogen level showed elevation on 1st–5th postoperative days. We thus conclude that decreases of RBC deformability (i.e., higher RCTT) were characteristic and specific on early postoperative days after renal ischemia–reperfusion and that these alterations were prevented by pre-ischemia administration of allopurinol. [ABSTRACT FROM AUTHOR]