Morphological and Physiological Changes in the Urinary Tract Associated With Ureteral Dilation and Ureteropyeloscopy: An Experimental Study

No AccessJournal of Urology1 Jun 1993Morphological and Physiological Changes in the Urinary Tract Associated With Ureteral Dilation and Ureteropyeloscopy: An Experimental Study David M. Schwalb, Majid Eshghi, Marianna David Ian, and Israel Franco David M. SchwalbDavid M. Schwalb More articles by this author , Majid EshghiMajid Eshghi More articles by this author , Marianna David IanMarianna David Ian More articles by this author , and Israel FrancoIsrael Franco More articles by this author View All Author Informationhttps://doi.org/10.1016/S0022-5347(17)36456-XAboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookLinked InTwitterEmail The gross and microscopic effects of four common modes of ureteral dilation and ureteroscopy were examined in 26 renoureterai units in 13 minipigs. Acutely, ureters subjected to mechanical (bougie, Teflon, or balloon) ureteral dilation and ureteropyeloscopy (UPS) demonstrated active mucosal bleeding with multiple sites of perforation, whereas ureters subjected to hydraulic dilation and UPS were significantly less traumatized. Two weeks after mechanical ureteral dilation and UPS, 3 of 6 ureters were obstructed radiographically, whereas all 7 hydraulically dilated ureters were unobstructed. By 6 weeks, all radiographic evidence of obstruction had resolved in the mechanically dilated group. While 5 of 6 mechanically dilated ureters showed extensive scarring with muscle loss 4 to 6 weeks after dilation, no scarring was seen in those ureters dilated hydraulically. Renal pelvic pressure (RPP) was measured continuously with a nephrostomy catheter in vivo during (bougie, Teflon, balloon and hydraulic) ureteral dilation and UPS. Renal pelvic pressure during rigid ureteroscopy approximated the resting pelvic pressure plus the irrigant height above the kidney or set pressure on a hydraulic pump, plus a “scope effect” which was characterized by a 20 to 25mm. Hg increase in RPP produced by moving the endoscope in the ureter without flow. The effects on RPP of continuous bladder drainage with a urethral catheter and renal pelvic decompression with an open-ended ureteral catheter passed into the renal pelvis through the ureteroscope working channel were also examined. The maximum RPP was evaluated in vitro in a separate group of 16 freshly harvested pig kidneys of similar weight examined immediately after sacrifice and was found to be 439mm. Hg. We also studied the immediate and long-term effects of low (<120cm. H20 or 90mm. Hg) versus high (>200cm. H20 or 150mm. Hg) RPP on renal histology. Acutely, high pressure caused diffuse denudation and flattening of the caliceal urothelium, submucosal edema and congestion not seen in calyces subjected to low irrigant pressure. Four to six weeks later, there was a higher incidence of columnar metaplasia, subepithelial nests and pericalyceal vasculitis in calyces subjected to high pressure as compared with those subjected to low irrigant pressure. Acutely, renal tubules subjected to high irrigant pressure demonstrated marked vacuolization and degeneration, whereas tubules subjected to low pressure appeared normal. At 4 to 6 weeks, focal scarring was seen in 5 of 7 kidneys subjected to high irrigant pressure, whereas no scarring was noted in all 6 kidneys subjected to low irrigant pressure. In summary, it seems that hydraulic intramural ureteral dilation is less traumatic than mechanical modes of dilation with less potential for ureteral scarring and stricture. Prolonged exposure of the minipig kidney to high RPP (>200cm. H20) during UPS resulted in renal scarring and inflammation not seen following low pressure (<120cm. H20) irrigation. Because the human kidney is anatomically and physiologically similar to the minipig kidney, it may respond to high renal pelvic pressures in a similar fashion. © 1993 by The American Urological Association Education and Research, Inc.FiguresReferencesRelatedDetailsCited byOmar M, Noble M, Sivalingam S, El Mahdy A, Gamal A, Farag M and Monga M (2018) Systemic Inflammatory Response Syndrome after Percutaneous Nephrolithotomy: A Randomized Single-Blind Clinical Trial Evaluating the Impact of Irrigation PressureJournal of Urology, VOL. 196, NO. 1, (109-114), Online publication date: 1-Jul-2016.Jakobsen J, Holst U, Jakobsen P, Steen W and Mortensen J (2018) Local and Systemic Effects of Endoluminal Pelvic Perfusion of Isoproterenol: A Dose Response Investigation in PigsJournal of Urology, VOL. 177, NO. 5, (1934-1938), Online publication date: 1-May-2007.PRABAKHARAN S, TEICHMAN J, SPORE S, SABANEGH E, GLICKMAN R and McLEAN R (2018) PROTEUS MIRABILIS VIABILITY AFTER LITHOTRIPSY OF STRUVITE CALCULIJournal of Urology, VOL. 162, NO. 5, (1666-1669), Online publication date: 1-Nov-1999.TEICHMAN J, CHAMPION P, WOLLIN T and DENSTEDT J (2018) HOLMIUM: YAG LITHOTRIPSY OF URIC ACID CALCULIJournal of Urology, VOL. 160, NO. 6 Part 1, (2130-2132), Online publication date: 1-Dec-1998.Camilleri J, Schwalb D and Eshghi M (2018) Bilateral Same Session UreteroscopyJournal of Urology, VOL. 152, NO. 1, (49-52), Online publication date: 1-Jul-1994. Volume 149Issue 6June 1993Page: 1576-1585 Advertisement Copyright & Permissions© 1993 by The American Urological Association Education and Research, Inc.KeywordsminiatureureterdilatationswineMetricsAuthor Information David M. Schwalb More articles by this author Majid Eshghi More articles by this author Marianna David Ian More articles by this author Israel Franco More articles by this author Expand All Advertisement PDF downloadLoading ...