Modified technique for dilatation of difficult nephrostomy tracts.

Dilatation of a percutaneous nephrostomy tract often is a difficult step, especially in patients who had previous renal surgery. Initial use of the central rod of a telescoping metal dilator set with the backloaded first dilator allows us to avoid using the fascial dilators, which are not rigid enough to dilate the tough perirenal fibrous tissue. It also permits one-stage placement of the "safety" guidewire. This technique has proved so advantageous and convenient that we now use it routinely in all cases whether they are recent or recurrent.

Rigid ureteroscopes with fiberoptic imaging bundles: features and irrigating capacity.

A new ureteroscope design incorporates fiberoptic imaging bundles to replace the rod lens system in a rigid ureteroscope body. These ureteroscopes have evolved along two lines: instruments with a movable eyepiece and those with a small outer diameter (< 10F). The fiberoptic imaging bundles take up less space than the rod lens system. These ureteroscopes thus have a larger working channel than instruments of a similar outer diameter with rod lens imaging systems. Measurement of irrigation rates through a representative sample of these ureteroscopes demonstrated that gravity irrigation was adequate through the empty working channel. However, if an accessory instrument was placed in the working channel, gravity irrigation was insufficient in the smaller models. Manual irrigation was more than adequate under all conditions. The larger models now offer relatively little advantage to counter the decrease in image quality associated with the "honeycomb" fiberoptic image. Nevertheless, the more recent small ureteroscopes allow an adequate irrigant flow while accepting working instruments suitable for a variety of procedures. They thus seem to be ideal for diagnostic ureteroscopy, as they are quick and easy to use, not even requiring ureteral dilation. Furthermore, their small size does not limit their therapeutic applications; on the contrary, it expands them.

Ureteroscopic biopsy in the upper urinary tract.

OBJECTIVES: To determine the optimal instruments and techniques for biopsy of upper urinary tract lesions through the small working channel in flexible and small semirigid ureteroscopes. METHODS: Urinary tract filling defects and other lesions were accessed with rigid or flexible ureteroscopy and biopsies were done using one or more devices: a 3 F cup biopsy forceps, 2.5 F and 3 F baskets, 2.5 F and 3 F graspers, 3 F snare, brush, and aspiration catheters. All samples, including the cup forceps samples, were sent for cytopathologic study, with those containing grossly visible tissue particles processed as a cell block. Only those specimens reported definitely positive or negative were considered diagnostic, whereas the others were grouped as nondefinitive. Not all sampling techniques could be used in every patient because of the size of the lesion and the technical limitations, including bleeding and instrument position during biopsy. RESULTS: There were 55 procedures in 43 patients. The indications included hematuria, filling defect, abnormal cytology, and periodic surveillance. A basket was used in 22 procedures and gave unequivocal results in 15. The other samples were equivocal, nondiagnostic, or unsuitable. The biopsy forceps provided a definitive result in 16 of 21 samples and the grasper was definitive in 5 of 6 samples. We could not obtain a suitable specimen using a snare in 2 cases and the brush gave a definitive result in only 5 of 11 cases. Samples of aspirate and washings were definitive in less than 50% of instances but detected some tumors for which other techniques were equivocal. CONCLUSIONS: For the best results, the largest biopsy specimen possible should be obtained. Aspiration or wash alone is often not diagnostic but can give a diagnosis in some patients. Tissue sampling devices, such as the forceps and basket, have an advantage in obtaining a larger sample. Cytopathologic techniques are particularly useful for handling and interpreting the small specimens obtained with ureteroscopic biopsy techniques.

Clinical experience with flexible ureteropyeloscopy.

Flexible ureteroscopes and their accessory working instruments have undergone tremendous design advances since the earliest reports in the 1960s. These changes have allowed for the expansion of indications for flexible ureteroscopy with the emphasis now on therapeutic and not just diagnostic applications. This report covers 290 procedures done with actively deflectable, flexible ureteroscopes on 222 patients. Followup averaged 11.2 months in 228 patients, while the remaining 62 were followed by the original referral center. Included were 154 procedures for stones and 79 for tumors or filling defects. Of the procedures 149 were performed with the patient under local anesthesia with sedation, while 128 were done with use of general anesthesia. The procedure was done in only 22% of the cases for purely visual diagnosis without any interventional manipulation. More than 42% of the cases involved stone retrieval or lithotripsy, in which case the laser was most commonly used (56 cases). The total success rate was 95.5%, and the most common complications were colic or pain in 9% and fever in 6.9%. A stricture developed in 2 patients. A stent was left in more than 93% of the patients and the usual postoperative stay was less than 3 days. With the introduction of even more improved instruments, flexible ureteroscopy should continue to gain ground as an option for the management of upper urinary tract pathology.