Encrustation of urologic double pigtail catheters-an ex vivo optical coherence tomography (OCT) study.

This study aims to evaluate whether optical coherence tomography (OCT) using both the surface and the endoluminal technique is feasible to investigate the locations and degree of encrustation process in clinically used ureteral stents. After removal from patients, 14 polyurethane JJ stents were investigated. A fresh JJ served as a control. The external surfaces were examined using an endoscopic surface OCT whereas the intraluminal surfaces were investigated by an endoluminal radial OCT device. The focus was on detection of encrustation or crystalline sedimentation. In 12 female and two male patients, the median indwelling time of the ureteral catheter was 100 days (range, 19-217). Using the endoluminal OCT, the size and grade of intraluminal encrustation could be expressed as a percentage relating to the open lumen of the reference stent. The maximum encrustation observed resulted in a remaining unrestricted lumen of 15-35 % compared to the reference. The luminal reduction caused by encrustation was significantly higher at the proximal end of the ureteral stent as compared to its distal part. The extraluminal OCT investigations facilitated the characterization of extraluminal encrustation. OCT techniques were feasible and facilitated the detection of encrustation of double pigtail catheters on both the extra and intra luminal surface. Quantitative expression of the degree of intraluminal encrustation could be achieved, with the most dense and thickened occurrence of intraluminal incrustation in the upper curl of the JJ stent.

Laser therapy for upper urinary tract transitional cell carcinoma: indications and management.

CONTEXT: Ureteroscopically guided laser techniques are commonly used in the treatment of upper urinary tract transitional cell carcinoma (UUTT); however, there is an ongoing debate with regard to indication and management. OBJECTIVE: To review the indication, feasibility, and treatment outcome of laser application for definitive endoscopic treatment of UUTT, focusing on technical aspects of different laser devices and their impact on tissue. EVIDENCE ACQUISITION: PubMed and Medline were searched for reports on laser therapy in UUTT from 1980 to 2008, with particular focus on the technical background of various laser systems. EVIDENCE SYNTHESIS: For decades, nephroureterectomy has been considered the gold standard for treating UUTT. With the intent to preserve functioning renal parenchyma, minimally invasive approaches, initially advocated for patients requiring a nephron-sparing approach (ie, single functioning kidney, renal insufficiency or significant comorbidities), have gained widespread acceptance due to advances in ureteroscopy, percutaneous renal surgery, and laparoscopy. Ureteroscopically guided laser ablation has been used successfully, resulting in recurrence rates ranging from 31% to 65% and disease-free rates of 35% to 86%, depending on stage and grade at diagnosis. CONCLUSIONS: To obtain the highest treatment success, the initial staging and grading of the tumour is crucial. Because low-grade tumours rarely if ever progress in stage or grade, the success rate of ureteroscopic therapy parallels that of endoscopic resection of identical bladder tumours. In the treatment of higher grade, advanced tumours, ureteroscopic therapy is less likely to be curative, and thus, endoscopic manoeuvres can only be palliative. Due to the relatively low prevalence of this tumour and the lack of comparable randomised, multicentre trials, the indications for an endoscopic laser treatment option has to be defined based on the patient's individual situation.