الفهرس 
ANATOMY OF THE URETEROnly 14 pages are availabe for public view
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Abstract
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SUMMARY AND CONCLUSION
reteral stents are a convenient means of drainage for the upper urinary tract and will continue to be an essential tool in the practicing urologist’s armamentarium.
However, their use is not devoid of side effects and they cause a wide range of urinary symptoms that affect the patient’s global health and quality of life. They are associated with a variety of irritative urinary tract symptoms including dysuria, urgency and frequency.
These symptoms were marked in the immediate post operative period then tended to decrease over time. Other symptoms which were annoying included haematuria, loin pain, suprapubic pain, urethral and perineal pain, also they were marked in the immediate post operative period then declined over time.
Studies directed to assess ureteral stent discomfort remain a challenge since pain is the primary end-point, which can lead to subjective and variable conclusions and may be influenced by confounding variables such as BMI, age and comorbidities. Also, despite strict exclusion criteria, other aspects may be difficult to identify at the time of enrollment.
Recurrent stone formers who suffer from chronic pain or narcotic dependency are examples. Besides, the pain provoked by the primary pathology or associated intervention such as ureteroscopy can confound the cause effect analysis of the presence of the stent.
In the face of this, future efforts must focus on the refinement of assessment tools and continued development of stent materials targeting biocompatible/ biodegradable devices that would induce minimal tissue reaction and at the same time reliably degrade either on demand or in a predictable pattern.
Medications to decrease morbidity should be regarded as a palliative adjunctive approach, but seem to be a more reachable solution in the short-term.
Stenting is no longer needed after most uneventful ureteroscopy procedures performed for ureteral stone disintegration. However, all endourologists should remember that, in addition to the stone and anatomy related predictive factors, a very limited subset of patients might require emergent stent placement during the early postoperative follow-up period. Thus, the surgeon should consider placement of a ureteral catheter, at least transient (overnight stenting), in an attempt to avoid emergent stent placement with the additional anesthesia requirement during early postoperative follow-up.
In situ SWL can be safely given as primary treatment for ureteral stones 2 cm or less in moderately and severely obstructed systems.
Ureteral stents have become more complex in recent years due to the many advanced technologies that are marketed in these products to the physicians who use them. However, more important than a detailed understanding of stent technology is an understanding of Ureteral anatomy and the techniques for safely accessing the ureter. It is also important to understand the morbidity associated with the use of indwelling stents and how complications are managed.
Ureteral stent development is currently focusing on the enhancement and evolution of stent design, composition material and stent coating. Several novel ideas currently under evaluation have demonstrated quite promising results, raising hopes that ureteral stents will improve their current efficiency and become a tool for the management of a growing variety of new indications in the near future.
Cardiovascular stent research is leading the way, introducing new ideas with possible promising implication in urinary tract stenting. Nevertheless, the ureter has different structural and histological characteristics as well as pathophysiological mechanisms implicated in the failure of long-term stenting.
Consequently, cardiovascular stent developments would probably require further refinement for ureteral application. Research and development of ureteral stents requires an extensive understanding of the mechanisms involved in ureteral stent failure. Urothelial hyperplasia, stent biofilm formation and encrustation, ureteral mobility and response to ureteral intraluminal foreign-body stimuli are only few of the implicated mechanisms that are not fully understood. Thus, further investigation is deemed necessary.
The ideal stent is still to be developed and efforts in this field are continuing toward this goal. Novel concepts have been developed although they are being further evaluated to implement them in the clinical setting.