Stent removal timing depends entirely on where the stent is placed and why it was put there, but the general principle is consistent: a stent should come out once it has done its job of holding a passage open, and before it starts causing problems of its own. For ureteral stents, that window is often a few weeks. For esophageal stents treating a benign narrowing, it can stretch to about three months. Airway stents sometimes stay in place for a year or more. The reasons behind these different timelines are worth understanding, because leaving a stent in too long carries real and sometimes serious risks.
Ureteral Stents Have the Tightest Removal Windows
Ureteral stents are thin tubes placed inside the ureter, the passage between a kidney and the bladder. They are among the most commonly placed stents in medicine, used after kidney stone procedures, urinary tract reconstruction, and kidney transplants. They are also the stents most likely to be searched for by patients wondering when they come out, because they tend to cause noticeable discomfort while they are in place.
After kidney transplant surgery, the evidence points strongly toward removal within three weeks. A meta-analysis found that pulling the stent out within that window cut urinary tract infection rates significantly compared to leaving it longer than three weeks, and earlier removal did not lead to more urinary leakage or narrowing of the ureter.1Transplantation. Timing of Double-J Stent Removal and Occurrence of Urological Complications For stents placed after kidney stone surgery or other urological procedures, removal typically happens within one to six weeks depending on the reason for placement and how the patient is healing. There is no single universal deadline, but the longer a ureteral stent sits inside the body, the more likely it is to develop problems.
Biliary Stents Can Stay Longer Than Doctors Once Thought
Plastic biliary stents are placed in the bile duct to keep it open, often after gallstone removal or to relieve a blockage. The traditional guidance has been that plastic biliary stents should be exchanged or removed within about three months, based on the assumption that they clog relatively quickly. But real-world data from a tertiary referral center, collected partly because the COVID-19 pandemic delayed scheduled removals, showed something surprising: the majority of plastic biliary stents remained functional for up to six months without adverse outcomes, and stents removed after 90 days did not show a significant increase in stent-related complications.2PubMed Central. Clinical impact of delayed plastic biliary stent removal because of the COVID-19 pandemic: the experience from a tertiary ERCP referral center
That finding does not mean biliary stents should be routinely left in for six months. It does suggest that if a patient’s follow-up appointment gets pushed back, the risk of a delayed removal is lower than previously feared. Metal biliary stents, which are used for longer-term drainage especially in cancer patients, follow different rules and are sometimes left in permanently, since the goal in those cases is palliation rather than cure.
Esophageal Stents and the Tissue Ingrowth Problem
Stents placed in the esophagus to treat benign strictures, where scar tissue narrows the swallowing passage, face a specific biological clock. The body recognizes the stent as foreign and starts growing tissue around and through it. This reaction means esophageal stents should be removed no later than three months after placement, because after that point the ingrowth of tissue into the stent’s mesh makes extraction much more difficult and risky.3Techniques and Innovations in Gastrointestinal Endoscopy. Stents for benign esophageal strictures
This is one of those areas where the reason for removal is not that the stent has done its job, but that the body’s reaction to the stent creates a new problem. Even when the stricture has not fully resolved, the stent needs to come out to avoid a situation where removal becomes a surgical ordeal. If the narrowing returns afterward, doctors may place a new stent or try other approaches like dilation.
Airway Stents Can Take Over a Year
Silicone stents placed in the trachea or bronchi to hold open an airway narrowed by scarring, particularly after tuberculosis, operate on a much longer timeline. A study of 344 patients with post-tuberculosis airway narrowing found that about 69% ultimately maintained open airways after the stent was removed. Interestingly, stents that stayed in place for 12 to 24 months were associated with more successful removal outcomes than those removed before the one-year mark.4J Korean Med Sci. Clinical Factors for Successful Removal of Airway Silicone Stents in Patients With Post-Tuberculosis Tracheobronchial Stenosis
The logic here is that the airway needs enough time to remodel and stabilize. Pull the stent too early and the scar tissue may collapse the airway again. The study also found that certain patient factors predicted better outcomes: older age, male sex, and the absence of certain lung findings on imaging all correlated with successful removal on the first attempt. For airway stents, patience is part of the treatment.
Coronary Stents Are Permanent, With Rare Exceptions
Metallic stents placed in coronary arteries during angioplasty are designed to stay in the body forever. Once deployed, a coronary stent becomes embedded in the artery wall as the vessel lining grows over it. Removing one is not part of normal care and is considered an extreme last resort. In a reported case where a coronary stent dislodged during placement and a second fully deployed stent had to be extracted along with it, the authors described the procedure as “generally prohibited” because of the risk of severe complications.5PubMed Central. Extraction of a Fully Deployed Coronary Stent during Retrieval of Another Dislodged Stent The extraction succeeded, but only because the operator had detailed knowledge of the specific stent and surrounding anatomy.
The permanence of coronary stents is why the question “when can it be removed?” rarely applies to heart patients. What does apply is how long a patient needs to stay on blood-thinning medications after placement, which depends on the type of stent and the patient’s individual risk factors. That is a management question, not a removal question.
Why Leaving a Stent Too Long Is Risky
The problems that develop when stents overstay their welcome vary by location, but the underlying theme is the same: the body treats stents as foreign objects, and over time the biological response to that foreign object intensifies.
For ureteral stents, the primary concern is encrustation, where minerals from urine deposit onto the stent surface, sometimes to the point where the stent becomes a rigid, stone-like structure that cannot be pulled out through normal means. The mechanism behind encrustation involves multiple steps: proteins coat the stent surface, bacteria form a sticky biofilm layer, and minerals crystallize on top of that layer.6PubMed. Ureteral Stent Encrustation: Epidemiology, Pathophysiology, Management and Current Technology The longer the stent stays in, the worse the buildup gets. Patients with a history of kidney stones are at particular risk: stone-forming history was the only significant risk factor for encrustation at the time of stent removal in one study.7African Journal of Urology. Forgotten ureteral stents: Risk factors, complications and management
A separate case report documented something else happening inside stents that stayed too long: thick biofilm structures covering nearly the entire inner lumen and outer surface of ureteral stents in kidney transplant patients. In those cases, the patients had not developed infections, but the biofilm was extensive enough to be notable on examination.8PubMed Central. Detection of microbial biofilms inside the lumen of ureteral stents: two case reports Not every biofilm leads to infection, but the presence of biofilm creates a reservoir where bacteria can thrive if conditions shift.
The Forgotten Stent Problem
One of the most preventable but surprisingly common complications in urology is the “forgotten” ureteral stent, a stent that stays in the body long past its intended removal date because the patient did not return for the follow-up appointment, or the healthcare system lost track of the stent entirely. A systematic review of forgotten ureteral stents found that encrustation occurred in roughly 81% of cases and urinary tract infections in about 40%.9PubMed Central. Forgotten ureteral stents: a systematic review of literature Those are not small numbers, and the complications can be severe enough to require complex surgical retrieval.
The consequences of a forgotten stent can escalate quickly. In one case involving a kidney transplant patient, an encrusted stent fractured during an attempted removal, leading to a serious bloodstream infection and hemodynamic instability. The patient required emergency procedures and ultimately a combined endoscopic surgery to retrieve all the fragments.10Journal of Clinical and Health Sciences. A Case Report on ECIRS for the Complex Retrieval of an Encrusted Ureteric Stent in a Renal Transplant Recipient
The medical system has started taking this problem more seriously. A stent tracking algorithm tested on over 2,100 patients retrospectively flagged about 16% as potentially harboring forgotten stents, and ultimately identified 12 patients who actually had them and needed to be contacted for removal.11PubMed. Development and Validation of the Stent Tracking Algorithm Registry for Monitoring and Retrieving Forgotten Ureteral Stents Meanwhile, smartphone-based stent registries with automatic text message reminders have shown impressive results. In one multi-center study, the group using a smartphone stent-tracking system had a 100% on-time removal rate, compared to 87% in the manual tracking group, where 13% of patients had forgotten stents.12Asian Journal of Urology. Smartphone application stent registry with automatic short-message service reminders mitigates the issue of forgotten ureteral stents Another mobile point-of-care application caught three out of 115 patients who did not return for their scheduled extraction, allowing the clinical team to contact them and get the stents removed.13PubMed. Preventing the Forgotten Ureteral Stent by Using a Mobile Point-of-Care Application
If you have a ureteral stent, write down your removal date somewhere you will not lose it. The hospital might send reminders, or they might not. This is one of those situations where a personal calendar alert could prevent a genuinely dangerous outcome.
How Removal Actually Works
The removal procedure depends on the type of stent and where it is. Ureteral stents are typically removed using a cystoscope, a thin camera threaded through the urethra into the bladder, where the doctor grabs the lower end of the stent and pulls it out. The procedure is quick but not exactly comfortable. Different sedation approaches exist, ranging from intravenous painkillers to short-acting sedation with propofol.14PubMed Central. Pain and satisfaction during rigid cystoscopic ureteral stent removal: a preliminary study
Some newer ureteral stents are designed to make removal easier. Magnetic stents have a small magnetic cube attached to the end that sits in the bladder. For removal, a catheter-like instrument with a magnetic tip is inserted, the two magnets connect, and the stent is pulled out without needing a cystoscope at all.15PubMed. Magnetic Ureteral Stent Removal Without Cystoscopy: A Randomized Controlled Trial For children, this kind of approach is especially appealing because standard cystoscopic removal of a ureteral stent typically requires general anesthesia.16Journal of Pediatric Surgery Open. Double J ureteral stent removal following pediatric laparoscopic pyeloplasty without cystoscopy Externalized stents, which have a string that exits the body, can be removed in the office without anesthesia. A state-of-the-art review of pediatric ureteral stenting noted that externalized options commonly enabled office removal without general anesthesia, and magnetic systems showed high outpatient retrieval success.17PubMed Central. Pediatric ureteral stenting: state-of-the-art review
Esophageal and biliary stents are removed endoscopically, using a scope passed through the mouth. Airway stents require rigid bronchoscopy, a procedure done under general anesthesia. Coronary stent removal, as mentioned, is essentially never planned.
Stents That Remove Themselves
The most elegant solution to the removal problem is a stent that dissolves on schedule. Bioresorbable stents are designed to provide structural support for a defined period and then gradually break down inside the body, leaving nothing behind.
In cardiology, bioresorbable coronary scaffolds were built to deliver the same mechanical support and drug release as permanent metal stents during the first year, then fully dissolve within two to four years.18EuroIntervention. Bioresorbable coronary scaffolds are ready for a comeback: pros and cons The idea is that once the artery has healed and remodeled, the scaffold is no longer needed, and its absence removes the long-term risk of late clot formation on a permanent implant. The first generation of these devices had mixed clinical results, but the technology is still being refined. Magnesium-based stents have shown positive outcomes, fully absorbing within about 12 months, while iron-based versions take closer to three years to dissolve.19PubMed. Coronary bioresorbable metallic stents: Advancements and future perspectives
The concept extends beyond the heart. Biodegradable airway stents are being developed to address a specific frustration with silicone airway stents: their removal requires a second procedure under general anesthesia, with all its attendant risks and costs. A biodegradable version would maintain airway patency for a set period and then gradually vanish, sparing the patient that second procedure entirely.20Karger. Biodegradable Airway Stents – Bench to Bedside: A Comprehensive Review These remain mostly in the research phase, but the appeal is obvious. The hardest part of stent management has always been the removal, and a stent that handles its own exit could change the calculus for a lot of patients.
Early Experimental Removable Designs
The idea of a stent that could be deployed permanently but then recaptured if needed is not new. In the 1990s, a device called the HARTS (Heat Activated Removable Temporary Stent) used a shape-memory alloy called Nitinol. It could be expanded into place with a balloon like any standard stent, but when warm saline solution was flushed over it, the metal returned to a preset smaller shape, allowing the stent to be pulled back out through a catheter.21Journal of Interventional Cardiology. Current Status and Potential Applications of the Harts Removable Stent The concept was clever but never became mainstream. It does illustrate that clinicians have been trying to solve the permanence problem for decades, and that the current generation of bioresorbable devices is the latest chapter in a long engineering effort rather than a sudden breakthrough.
When Removal Is Not Straightforward
Most stent removals go smoothly. But when they don’t, the complications tend to cluster around a few predictable scenarios. Encrusted ureteral stents can resist standard cystoscopic retrieval, requiring shock wave lithotripsy to break up the mineral deposits before the stent can be freed. Esophageal stents with significant tissue ingrowth may require piecemeal removal. And any stent that has fractured in place creates a retrieval puzzle that may involve multiple surgical approaches.
The difficulty of a complicated removal is one of the strongest arguments for staying on schedule. A stent removed at its intended time is almost always a straightforward procedure. A stent removed months or years late can turn into a multi-step ordeal. That gap between easy and hard is entirely a function of time, and it is largely within the patient’s control to prevent.