Editing Upper Urinary Tract Urothelial Cancer (section)

====== Technical considerations ======
*'''Approach'''
** '''Retrograde (ureteroscopic) vs. antegrade (percutaneous)'''
*** '''Choice depends largely on the tumor location and size'''
**** '''Retrograde preferred when tumor size, number, and access allow complete tumor ablation.'''
**** '''Percutaneous antegrade tumor ablation preferred for (3):'''
****#'''Larger tumors'''
****#'''Tumor difficult to access in a retrograde fashion'''
****#'''Patients who have undergone prior radical cystectomy or urinary diversion'''
**** In cases with multifocal involvement, combined antegrade and retrograde approaches can be considered
** '''Retrograde approach'''
*** '''Advantages (2)''':
***# '''Lower morbidity than percutaneous and open surgical counterparts'''
***# '''Maintenance of a closed system'''
***#* '''Non-urothelial surfaces are not exposed to the possibility of tumor seeding'''
*** '''Disadvantages (2):'''
***# '''Smaller instruments required'''
***#* '''Smaller endoscopes have a smaller field of view and working channel which limits the size of tumor that can be approached in a retrograde fashion. These small instruments limit the accuracy of biopsies, especially with regard to staging'''
***# '''Some portions of the upper urinary tract, such as the lower pole calyces, cannot be reliably reached with working instruments.'''
*** '''Technique'''
**** Without ureteroscopic resectoscope
*****Debulk tumor by use of either biopsy forceps or a flat wire basket engaged adjacent to the tumor. 
******This technique is especially useful for low-grade papillary tumor on a narrow stalk. 
*****Treat tumor base with either electrocautery or laser energy sources. 
*****Send specimen for pathologic evaluation.
**** With ureteroscopic resectoscope
*****Use resectoscope to remove the tumor. 
******Only the intraluminal tumor is resected, and no attempt is made to resect deep (beyond the lamina propria).
**** A ureteral stent is placed for a variable duration to aid with the healing process.
** '''Antegrade approach'''
*** '''Advantages (4):'''
***# '''Ability to use larger instruments that can remove a large volume of tumor in any portion of the renal collecting system'''
***# '''Improved tumour staging and grading because deeper biopsy specimens are obtained'''
***# '''May avoid the limitations of flexible ureteroscopy, especially in complicated calyceal systems or areas difficult to access, such as the lower pole calyx or the upper urinary tract of patients with urinary diversion.'''
***# '''The established nephrostomy tract can be maintained for immediate postoperative nephroscopy and administration of topical adjuvant therapy'''
*** '''Disadvantages (4):'''
***# '''Increased morbidity compared with ureteroscopy'''
***# '''Risk of nephrostomy tract insertion'''
***# '''Procedure usually requires inpatient admission'''
***# '''Potential for tumor seeding outside the urinary tract; tract seeding is a possibility but appears to be an uncommon event'''
*** '''Technique'''
**** '''A nephrostomy tube is left in place.''' 
*****This access can be used for second-look follow-up nephroscopy to ensure complete tumor removal. 
****Follow-up (second-look) nephroscopy is performed 4-14 days later to allow adequate healing. 
*****The tumor resection site is identified, and any residual tumor is removed.
**** Complications from percutaneous management of tumors are similar to those for benign renal processes and include bleeding, systemic absorption of hypo-osmotic irrigation (with monopolar resection), perforation of the collecting system, and secondary ureteropelvic junction obstruction.
*'''Tumor size[https://pubmed.ncbi.nlm.nih.gov/37096584/]'''
** '''Tumors < 1.5 cm in size may be optimal for endoscopic ablation given a lower risk of invasive disease.'''
*** Tumors ≥ 1.5 cm in size are associated with a > 80% risk of invasive disease
***'''Larger tumors (≥ 1.5 cm) may be considered for ablation based on the provider’s experience and assessment of the need for kidney sparing surgery.'''
*Energy source[https://pubmed.ncbi.nlm.nih.gov/37096584/]
**Can be performed with laser or electrocautery
***Electrocautery is delivered through a small Bugbee electrode (2 or 3 Fr)
****However, the variable depth of penetration can make its use in the ureter dangerous, and circumferential fulguration should be avoided because of the high risk of stricture formation.
***Thulium, holmium (Ho:YAG), and Neodymium (Nd:YAG) are laser energies that have been used
* Chemoablation[https://pubmed.ncbi.nlm.nih.gov/37096584/]
**May be employed either through retrograde ureteral catheter instillation or percutaneous access with fluoroscopic imaging guidance
*Ureteral access sheath[https://pubmed.ncbi.nlm.nih.gov/37096584/]
**Prior to placement of any ureteral access sheath, the entire ureter should be directly visualized in order to avoid missing any luminal neoplasms, especially in the distal ureter
** Advantages (3):
**#Allows for repeated scope passage up and down the ureter for sampling
**#Means of fluid egress from the upper tract to avoid excess pelvicalyceal hydrostatic pressure from irrigation solutions
**#Lower rate of intravesical recurrence (based on observational study)