The affliction caused by the ureteral stent is well known. Both necessary and undesirable, ureteral stents have long been the subject of multiple studies by investigators dedicated to reducing suffering related to their use. Multiple studies have shown promise, and ongoing trials persist, however, the ideal ureteral stent does not currently exist.^1,2 The Urinary Stone Disease Research Network (USDRN) performed the Study to Enhance Understanding of Stent-Associated Symptoms (STENTS), a multicenter prospective observational cohort study of 484 participants, which allowed a comprehensive investigation to identify risk factors for stent-associated symptoms (SAS) with a nested cohort of 40 participants completing daily assessments and in-depth interviews for a thorough capture of the stent experience.³ Contrary to expectations, there was found to be no association of stone or operative factors, including ureteral instrumentation or ureteral stent features, with increased symptoms. Patient rather than surgical factors were associated with increased postoperative SAS with findings as follows: (1) older age was protective, associated with a lower intensity of pain, and no difference based on sex; (2) chronic pain conditions, report of depressive symptoms, and history of prior severe stent pain each were associated with a higher degree of pain (Figure). Fewer risk factors were identified for increased lower urinary tract symptoms (LUTS), with similar findings regarding age and depression. BMI was also associated with symptoms. As risk factors for LUTS were similar predictors for pain, the remainder of this article will focus on pain and its mitigation.

Pain

The pain experience can be understood in the following dimensions: nociception—the detection of injury; perception—typically due to a noxious stimulus; suffering—the negative response influenced by pain, fear, anxiety, and stress, among others; pain behaviors—responses to injury and how we as clinicians infer the existence of nociception, pain, and suffering. Underlying each of these dimensions lie anatomical, physiological, and psychological factors.⁴ The process of neuroplasticity—the ability of the nervous system to adapt in response to stimuli, every person distinct in their storied lives, renders infinite variation in the perception of pain. Implicit in these concepts is a widely variable experience, decidedly unique to each person. In other words, pain is a highly individualized experience.

This suggests that pain perception may be modulated by influences independent of nociception, such as psychosocial factors including stress, anxiety, and depression. These factors were assessed in STENTS, however, given the high degree of correlation, only PROMIS depression scores were utilized in the multivariable risk model; higher scores in other psychosocial domains were expected to show similar findings.³ Preoperative anxiety, as an example, has been found to increase pain scores and analgesic use after elective surgery in multiple fields.⁵

The USDRN, comprised of experts in urology, nephrology, endocrinology, and pain medicine, led to novel investigations in the study of stent pain. Quantitative sensory testing (QST) was undertaken to determine the association of preoperative hypersensitivity and central sensitization to stent pain following URS.⁶ Central sensitization, a function of neuroplasticity, occurs when recurring or sustained pain insults, such as repeated episodes of renal colic or prolonged ureteral obstruction, increase neuronal excitability resulting in the development of hyperalgesia—an insult that is typically mildly painful becomes intensely more painful, for example, stent pain that is disproportionate to the degree of ureteral insult.⁷ In this study, preoperative hypersensitivity and central sensitization using QST measures were indeed found to be associated with increased SAS for the first time in the study of ureteral stent pain, suggestive of a central component of pain that may not respond to peripherally targeted therapy, opioids included.⁸ This concept introduces a wide array of possibilities for new mechanistic studies.

Improving Outcomes

One of the most intuitive strategies for reducing SAS is pharmacological treatment with several classes of medications aimed to do just that, including analgesics, α-blockers, anticholinergics, and phosphodiesterase 5 inhibitors, the combination of which has shown to provide better general health scores and symptom control,⁹ useful for most post-URS patients to a mild degree, but seemingly futile in those at high risk for severe SAS.

As ongoing efforts continue to design the optimal ureteral stent, equal efforts should be given to understanding the basis of pain individually, optimizing management through a multifaceted approach and improving factors known to increase pain. To do so, it would befit us to consider innovative, alternative, and perhaps unconventional means for stent pain mitigation, especially for those at high risk. An individualized approach may include a personalized medication regimen for those with evidence of central pain, and adjunctive approaches to management of peripherally derived pain, such as music therapy, biofeedback, meditation, physical therapy, and acupuncture, to name a few. Optimization of anxiety, depression, and baseline pain may require collaboration with primary care physicians, psychotherapists, psychiatrists, neurologists, and pain specialists.

If the holistic approach to stent symptom mitigation is not readily accepted or easily adaptable in clinical urology practice, we can focus on trusted strategies—with the continual advancement of endourologic technology, such as smaller ureteroscopes, suction devices, and improved laser technology, the adoption of stentless procedures becomes ever more possible. In patients at very high risk, one could even consider referral to a high volume endourologist to maximize the chance of stent omission. The less invasive and stentless extracorporeal option of shock wave lithotripsy could be considered and ongoing studies on burst wave lithotripsy in the future may offer office-based procedures, allowing treatment before a clinical event occurs, with minimal tissue injury.¹⁰ Best yet, we can confidently advise this high-risk group they are the audience that ought to be captive for primary stone prevention, to control their burdensome disease, well before a stent is even necessary.