Intrarenal Backflow and Renal Perfusion during Increased Intrapelvic Pressure in Excised Porcine Kidneys

Abstract

The effect of increased intrapelvic pressure on renal perfusion was examined by simple magnified angiography of freshly excised artificially perfused kidneys of adult Danish Landrace pigs. In all kidneys control angiography was performed at normal intrapelvic pressure (0-5 mmHg). Intrapelvic pressure was raised by retrograde ureteral perfusion of saline in 9 kidneys. Repeat angiography was performed at an intrapelvic pressure of 30-35 mmHg (4 kidneys), 50-55 mmHg (5 kidneys) or 0-5 mmHg (4 kidneys). Angiography demonstrated a delay in arterial filling in kidneys with increased intrapelvic pressure. Perfusate flow measurements showed a corresponding fall in perfusion flow. Retrograde ureteral perfusion was repeated at similar pressures using contrast medium. Intrarenal backflow (IRB) was demonstrated in all 9 kidneys with elevated intrapelvic pressure. IRB localized to 84 per cent of the compound papillae and to 40 per cent of the simple papillae, and was independent of the level of elevated intrapelvic pressure. One-third of the papillae with IRB had absent or markedly decreased arterial filling in the corresponding lobe at angiography. A third retrograde ureteral perfusion was done with a mixture of barium sulphate and gelatin in 4 kidneys. Light microscopy demonstrated that the primary pathway for IRB was canalicular. The contrast medium entered the interstice by three routes: (1) Tubular leakage in the papilla and the corticomedullary region, (2) tears originating in the papilla itself and (3) tears in the calyceal fornix with extension into the parenchyma.

A cut‐off value for the operation time and other risk factors in terms of the infection risk for flexible ureterorenoscopy

“…According to the Jung's et al study, with the use of forced irrigation during ureteroscopy, intrarenal pressure increases above 300 mmHg 14 . And it was established that according to the results obtained from some animal and human studies, when intrarenal pressure rises above 30 mmHg, some defence mechanisms which depend on the intrarenal pressure including pyelo‐tubular, pyelo‐venous, pyelo‐sineous and pyelo‐lymphatic backflow come into play 15‐18 . These mechanisms have the potential to decrease kidney function as well as they may be related to infectious and hemorrhagic process 14 .…”

“…But, we associated this difference with the length of the OT in the group which used the UAS. While some studies in the literature focused on some of the benefits of the sheath, they indicated its importance in terms of infection formation, indirectly interpreting the results they obtained from these studies 4,9,10,15‐17,19 …”

A Cut-Off Value for the Operation Time and the Other Risk Factors in Terms of the Infection Risk for Furs

“…According to the Jung's et al study, with the use of forced irrigation during ureteroscopy, intrarenal pressure increases above 300 mmHg 13 . And it was established that according to the results obtained from some animal and human studies, when intrarenal pressure rises above 30 mmHg, some defense mechanisms which depend on the intrarenal pressure including pyelo-tubular, pyelo-venous, pyelo-sineous and pyelo-lymphatic backflow come into play [14][15][16][17] . These mechanisms have the potential to decrease kidney function as well as they may be related to infectious and hemorrhagic process 13 .…”

Simultaneous Measurement of Pressure in the Calyces During RIRS in a Human Cadaver Model

“…As it is known from animal and human studies, with an increase of intrarenal pressure to 20-30 mmHg, pyelo-tubular backflow develops and blood circulation of the kidney decreases (13,14). When intrarenal pressure increases to 30-50 mmHg, the pyelovenous backflow becomes more evident and an increase in both pyelosinus and pyelolymphatic pressures results in forniceal rupture (14,15).…”