Is Stentless Ureteroscopy Safe in the Dusting Era?

By: Russell E. N. Becker, MD, PhD, University of Michigan, Ann Arbor; Andrew M. Higgins, MD, University of Michigan, Ann Arbor; Stephanie Daignault-Newton, MS, University of Michigan, Ann Arbor; Elaina Shoemaker, MS, University of Michigan, Ann Arbor; Casey A. Dauw, MD, University of Michigan, Ann Arbor; Khurshid R. Ghani, MBChB, MS, FRCS, University of Michigan, Ann Arbor | Posted on: 19 Sep 2023

It is well established that ureteral stenting after ureteroscopic stone treatment is associated with pain and urinary symptoms in many patients.1 Stent-related symptoms can drive unplanned health care utilization. In Michigan, clinical registry data from the Michigan Urological Surgery Improvement Collaborative (MUSIC) demonstrated a significant decrease in postoperative emergency department visits after ureteroscopy when ureteral stents were omitted.2,3 In the era of increased focus on the patient experience as an important component of the quality of care, the pendulum is swinging toward efforts to safely omit stents when possible—“stentless ureteroscopy.” Current AUA guidelines recommend ureteral stent omission after ureteroscopy and stone intervention if they meet the following criteria: normal contralateral kidney, no renal functional impairment, renal stone burden <1.5 cm, no planned second stage ureteroscopy, no ureteric injury or stricture, and no other anatomical impediments to stone fragment clearance.4 Despite this guidance, stenting remains commonplace, with multiple studies showing that ∼80% of all patients after ureteroscopy routinely receive a stent after their procedure.2,5 This likely reflects the prevailing dogma that placing a stent is the “safe” course, since stenting mitigates the theoretical risk of postoperative ureteral obstruction and an unplanned hospital visit. However, this risk may be overestimated, as only 0.5% of 399 stentless ureteroscopy cases in a large academic center required a return to the operating room for secondary stent placement.2

The emergence of several new technologies, including high-power holmium lasers, smaller flexible ureteroscopes, and the thulium fiber laser, has ushered in a new era of dusting laser lithotripsy technique, which is now utilized by many urologists.6,7 In contrast to the historical standard of fragmentation and active basket retrieval of fragments, the dusting technique—especially for kidney stones where they are broken down into submillimeter fragments (similar to shockwave lithotripsy)—provides an opportunity for surgeons to avoid the routine use of ureteral access sheaths with less trauma to the ureteral mucosa, therefore facilitating the practice of stent omission. A prospective multicenter comparison between dusting and fragmentation strategies found that stone-free rates and complications were equivalent, while dusting was significantly faster.8 All patients in that study received stents per protocol, but the opportunity to safely omit stents may be the strongest advantage of a dusting approach. With increased use of dusting, perhaps is it finally time for the field to shift our thinking to a default stent omission strategy, with stents placed only in cases with specific indications?

Table. Michigan Urological Surgery Improvement Collaborative Appropriateness Criteria Panelists’ Consensus Definition of Uncomplicated Ureteroscopya

Uncomplicated ureteroscopy
Age ≥18 years
American Society of Anesthesiologists (ASA) score <3
Not immunocompromised or pregnant
No evidence of functional/anatomic solitary kidney
No anatomic abnormalities (ie, stricture, ureteropelvic junction obstruction, horseshoe kidney)
No urinary tract reconstruction
No uncorrected bleeding diathesis, anticoagulant, and/or antiplatelet therapy
No history of neurogenic bladder or incomplete bladder emptying
No signs or symptoms of sepsis
No history of sepsis associated with urinary tract infection
No untreated positive urine culture
No stones in multiple locations (ie, both ureter and kidney)
Stone size ≤15 mm
Operative time ≤60 min
No balloon dilation of the ureter
Unilateral procedure
No plan for second look procedure
Retrograde ureteroscopy only
No ureteral perforation or trauma
aReprinted with permission from Hiller et al, Urol Pract. 2022;9(3):253-263.9
Figure. When can you omit ureteral stents after ureteroscopy? Michigan Urological Surgery Improvement Collaborative stent omission guidelines as determined by using the RAND/UCLA Appropriateness Methodology. Reprinted with permission from Hiller et al, Urol Pract. 2022;9(3):253-263.9 UA indicates urinalysis; URS, ureteroscopy.

Toward this end, MUSIC recently developed practice-based consensus guidelines on the appropriateness of ureteral stent omission following stone treatment after an uncomplicated ureteroscopy.9 Seven variables affecting stent decision making were identified: (1) stone size, (2) stone location (kidney or ureter), (3) pre-stenting status, (4) urinalysis or urine culture result, (5) nonballoon ureteral dilation performed, (6) use of a ureteral access sheath, and (7) presence of basketable-sized residual stone fragments. The Figure provides an overview of the criteria for stent omission, while the Table provides the MUSIC panel consensus definition of uncomplicated ureteroscopy. One key finding to emerge from this work was that pre-stented patients undergoing ureteroscopy are prime candidates for postoperative stent omission. Observational data from MUSIC showed that among pre-stented patients, those receiving a postoperative stent were more than twice as likely to have a postoperative emergency department visit or hospitalization, compared to those undergoing stent omission.3

Based on the available evidence to date and our institutional practice, we feel that stentless ureteroscopy is safe in appropriately selected cases. However, large-scale prospective data on the outcomes of stent omission are still lacking. A recent Cochrane review synthesized outcomes from 16 clinical trials with a total of 1,970 participants, and found that the strength of existing evidence is very low, with limited ability to draw meaningful conclusions.10 No studies to date have examined patient-reported outcomes or health care utilization after ureteroscopy (eg, office phone calls, messages, unplanned visits). The Cochrane review concluded that higher-quality and sufficiently large trials are needed to better inform decision-making. A recently opened pragmatic multicenter combined randomized and observational clinical trial, coordinated through MUSIC, and funded by the Patient Centered Outcomes Institute, aims to address the shortcomings of prior studies. The Stent Omission after Ureteroscopy and Lithotripsy study will comprehensively assess patient outcomes for stent omission vs placement after uncomplicated ureteroscopy in nearly 800 patients. The coprimary outcomes are patient-reported outcomes at days 7-10 after ureteroscopy, and 30-day unplanned postoperative health care utilization. Results from this 2-year clinical trial are anticipated to provide the largest prospective evidence to date on the safety and patient experience of stentless ureteroscopy in the modern era. We then hope to answer the question, is stentless ureteroscopy safe in the dusting era?

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