[Endourologic treatment of ureteral strictures. Experimental comparative study]

[Experimental study with Doppler ultrasound in partial chronic obstructive uropathy]

INTRODUCTION

This study has aimed to assess the hemodynamic parameters, Renal Resistive Index (RI), Peak Systolic Velocity (PSV), End-Diastolic Velocity (EDV) and Blood Flow of the Renal Artery (FR) by Doppler Ultrasound for diagnosis and monitoring postsurgical partial chronic obstructive uropathy.

MATERIAL AND METHODS

Fifty pigs were used. The experiment was divided into three phases. Phase I consisted of a duplex-Doppler evaluation of the both kidneys to determine the parameters under study. The ratio of each index is calculated as the difference between the value of study kidney and the contralateral. After, a fluoroscopic examination was performed by compressive cystography, excretory urography and retrograde ureteropyelography. Finally, a model of partial right ureteral obstruction was created. After six weeks of the obstructive model, Phase II was begun with the diagnosis of the uropathy, by means of the aforementioned diagnostic methods and the endourological treatment was completed. Phase III is a follow-up performed at 6 months of treatment using the same methods as in the previous phases.

RESULTS

Of the parameters studied, the EDV and its ratio showed greater sensitivity and specificity as a diagnostic marker of obstructive uropathy. In the postoperative monitoring, it was observed that the RI and the EDV returned to baseline levels, with the baseline values.

CONCLUSIONS

The ΔEDV and its ratio is the parameter that shows the greater efficacy for the diagnosis of chronic partial obstructive uropathy, however, it is insufficient to avoid conventional diagnostic techniques. All the parameters, mainly the EDV, have proven useful as complementary tests for monitoring after endourologic resolution of obstructive uropathy.

Cold cutting of ureteral stenosis with endoscopic scissors

OBJECTIVES

To study the procedure and results of cold cutting of ureteral stenosis with endoscopic scissors. Intrinsic or extrinsic ureteral stenosis can be congenital or acquired. Endoscopic dilation and incision is 1 potential option for ureteral intrinsic stenosis.

METHODS

During a 3-year period (2005-2007), a prospective study was performed of cold cutting of ureteral stenosis with endoscopic scissors in 17 consecutive patients (11 women and 6 men), aged 22-64 years. Of the 17 patients, 6 had been diagnosed with proximal ureteral stenosis, 3 with iliac ureteral stenosis, and 8 with pelvic ureteral stenosis. The procedure was performed with a semirigid 8.5Ch ureteroscope, catheterizing and dilation of the stenosis with a balloon catheter, cold cutting of the ureteral wall with scissors, including margins of healthy tissue at both ends of the stenosis, and a 6F double-J ureteral stent for 6 weeks.

RESULTS

The results were evaluated after 3 months with urography in 15 cases and diuretic renography in 2 cases. Analysis of the postoperative complications and urography was done at 12-24 months. Immediate success was obtained after the first endoscopic ureterotomy with scissors in 16 of 17 cases (94%). At 12-24 months, success was maintained in 88.5% of cases.

CONCLUSIONS

Cold cutting of ureteral stenosis with endoscopic scissors is a safe technique for the patient. This procedure could be a therapeutic option in cases of benign intrinsic ureteral stenosis of <15 mm.