**3.2.4 Imaging guidance**

The imaging guidance equipment is very important in renal access. The guidance system for urinary tract interventions are fluoroscopic guidance, real-time ultrasonography and CT scan.

#### **3.2.4.1 Ultrasound guidance**

The puncture of the desired calix can be done in dilated systems. If only the renal pelvic can be identified, initial puncture can be done at renal pelvic following with antegrade

Modern Surgical Treatments of Urinary Tract Obstruction 269

Fluoroscopic guidance is essential for guidewire manipulation especially in patients with non or mild dilatation of renal pelvis. Collecting system can be opacified with contrast following cystoscopic retrograde ureteral catheter placement, injection of intravenous contrast material and direct percutaneous puncture with 22 gauge needle. Pyelotubular and

In difficult cases, with non-dilated collecting system, the collecting system can be distended with retrograde ureteral balloon catheter. Fluoroscopy can demonstrate the position of the nephrostomy tube in the most desirable position (renal pelvis), minimizing the number of complications. To avoid radiation exposure to operator's hand, Amplatz needle holder can be used. (LeRoy., 1996). This equipment keeps the operator's hand out of the x-ray beam. The patient's table should be not so high that the operator's neck and face are too far from

Fig. 9. 21-gauge needle was introduced

toward the stone.

Fig. 7. Ultrasound imaging demonstrated a guidewire in dilated pelvis.

pyelosinus backflow can be avoided by not overinjecting the collecting system.

**3.2.4.2 Fluoroscopic guidance** 

the patient. (Fig. 8-11)

right flank pain.

Fig. 8. Right renal pelvic stone in patient of

Fig. 5. Patient in prone position for renal access.

pyelography for secondary definitive caliceal puncture. Ultrasound guidance is helpful in determining the depth and the angle of approach. (Juul et al., 1985 & LeRoy et al., 1984). Real time ultrasound is widely used for percutaneous access of a dilated collecting system and is beneficial in infants, pregnant women and patients following renal transplantation. (Falahatkar et al., 2010). The disadvantage of percutaneous nephrostomy access by ultrasound guidance, this guidance system may be compromised by rib artifacts. (Fig. 6, 7)

Fig. 6. Ultrasound machine as imaging guidance.

pyelography for secondary definitive caliceal puncture. Ultrasound guidance is helpful in determining the depth and the angle of approach. (Juul et al., 1985 & LeRoy et al., 1984). Real time ultrasound is widely used for percutaneous access of a dilated collecting system and is beneficial in infants, pregnant women and patients following renal transplantation. (Falahatkar et al., 2010). The disadvantage of percutaneous nephrostomy access by ultrasound guidance, this guidance system may be compromised by rib artifacts. (Fig. 6, 7)

Fig. 5. Patient in prone position for renal access.

Fig. 6. Ultrasound machine as imaging guidance.
