Table 1.
Comparative results of different access techniques.
| Access technique | Mean RE/FL time during PCA | Pros | Cons |
|---|---|---|---|
| Cone beam CT-guided access and control | 9.9 mSv/– | Helps to perform puncture in patients with abnormal anatomy. Low-risk of complications | Carries higher RE and requires more time for PCA |
| Laser guided complex punctures with UroDyna CT | 0.0969 mSv/– | Good for patients with complex anatomy, uncertain ultrasound findings, unsuccessful FL guided punctures | Immediate pre-procedural CT (6.11 mSv) is required, which increases RE and time of procedure |
| The laser direct alignment radiation reduction technique | –/7.09 s | Decreases mean access FL time. Easier technique for non-experienced surgeons | Requires special equipment |
| Ultrasound-guided access | –/17.7 s | Helps to decrease RE during PCA, while providing high success rate of PCA | PCA time was significantly longer in ultrasound guided group |
| Computer-assisted ultrasonic guidance | RE was eliminated | Facilitates renal targeting regardless level of surgeon's expertise and helps to eliminate RE | Requires special equipment |
| Ultrasound-guided access combined with “all-seeing needle” | RE was eliminated | Eliminates RE and simultaneously allows confirmation of proper placement of the needle by direct visualization of the pelvis and calyces | Requires special equipment |
| Intraoperative ultrasound augmentation with preoperative MRI for PCA | RE was eliminated | Eliminates RE during the procedure, and also gives complex 3D reconstruction. Very useful in cases where X-ray exposure contraindicated, and complex visualization is required | Pre-surgical MRI with marking is required |
| Ultrasound-guided puncture under EMT augmentation | RE was eliminated | Improves tracking of the needle (shorter time of puncture, lower number of attempts) and eliminates RE during PCA | Requires special equipment |
| Direct endoscopic visualization combined with conventional FL control | RE can be potentially decreased due to better visualization | Can be used in patients with anticipated difficulties during PCA (obesity, significant stone burden, non-dilated pelvicalyceal system, nephroptosis). Does not require special equipment | FL is still main visualization approach. Requires assistant who can control ureteroscope |
| Direct endoscopic visualization combined with ultrasound-guided access | –/3.5 s | Helps to significantly decrease FL time. Does not require special equipment. Helps to confirm correct PCA by direct visualization | Requires assistant who can control ureteroscope |
| Ureteroscopy assisted PCNL with electromagnetic guidance | RE was eliminated | Potentially eliminates the need for RE. Helps to confirm correct PCA by direct visualization. Provides constant 3D monitoring through the procedure |
Requires special equipment |
–, this number was not indicated or provided in the paper that was referenced; 3D, three dimensional; CT, computed tomography; EMT, electromagnetic; FL, fluoroscopy; MRI, magnetic resonance image; PCA, percutaneous access; PCNL, percutaneous nephrolithotomy; RE, radiation exposure.