Double J (DJ) ureteral stent is the most widely used indwelling stent for the management of patients with upper urinary tract obstruction symptoms.¹ Since 1967, ureteric stents have been routinely and widely used in urological procedures. These stents are primarily employed following elective surgeries for ureteric obstruction caused by intrinsic or extrinsic factors, including stones, strictures, ureteropelvic junction obstruction, retroperitoneal fibrosis, malignancies, and congenital anomalies². Ureteric stents are generally safe and well-tolerated; however, their use can lead to complications, ranging from mild issues to severe problems such as encrustation, urinary tract obstructions, and even renal failure. Factors contributing to stent encrustation include prolonged indwelling time, urinary tract infections (UTIs), and a history of concurrent stone disease³.  The removal of encrusted stents is among the most challenging endourological procedures. Neglected stents may lose tensile strength, increasing the risk of breakage or fragmentation during removal. A variety of treatment modalities, including shock wave lithotripsy (SWL), cystolithotripsy (CLT), ureteroscopic lithotripsy (URSL), percutaneous nephrolithotomy (PCNL), and open surgery, have been utilized to manage this complication⁴.

AIM

Forgotten double J stent Evaluation and management at a tertiary centre.

This retrospective study was conducted over a one-year period from August 2022 to August 2023, involving 25 patients with double-J (DJ) stents retained for more than six months without a clinical indication for prolonged stenting. The study aimed to analyze the demographic characteristics, socioeconomic status, indications for stenting, duration of stent retention, presenting complaints, evaluation, and management of these patients.The study included patients diagnosed with forgotten DJ stents, defined as stents retained beyond the recommended indwelling period of 3–6 months. Inclusion criteria required patients to be above 18 years of age, with a documented history of DJ stent placement and stent retention beyond the intended removal date. Patients with incomplete medical records or those who had their stents removed within the recommended timeframe were excluded from the study.

All patients underwent comprehensive evaluations, including ultrasonography of the abdomen and pelvis, X-ray of the kidney, ureter, and bladder (KUB), urine analysis, urine culture, serum creatinine assessment, and non-contrast computed tomography (NCCT) of the KUB region. Functional studies, such as CT urography and intravenous urography (IVU), were performed in patients with concomitant stone disease, while diethylene triamine penta-acetic acid (DTPA) scans were conducted in cases where a poorly functioning kidney was suspected based on functional imaging findings. Treatment decisions were guided by clinical and radiological findings.

For cases with minimal stent encrustation, stent removal was attempted using cystoscopy and gentle traction under C-arm guidance. If resistance was encountered during retrograde extraction, the procedure was abandoned. Severe encrustation or stone formation at the lower coil of the stent was managed using cystoscopic lithotripsy (CLT) with a pneumatic lithotripter or percutaneous cystolithotripsy (PCCL). Cases involving large stones in the upper coil or failed retrograde extraction required percutaneous nephrolithotripsy (PCNL). Open surgical procedures, such as pyelolithotomy and ureterolithotomy, were necessary for some patients. Re-stenting was performed in cases with complicated encrustation.

Table 1: Demographic data

The study included 25 patients aged 8–72 years (mean age 39.5), with 17 illiterate, 8 educated, and indwelling times ranging from 7 to 72 months.

Table 2: Distribution of subjects according to clinical presentation

The clinical presentations included flank pain (10 patients), irritative LUTS (3), AKI (1), asymptomatic cases (2), hematuria (4), and mixed symptoms (5).

Table 3: Indication for stent placement

The indications included PCNL (4 patients), URSL (7), open pyelolithotomy (2), open ureterolithotomy (1), emergencies like pyonephrosis/AKI (7), stent in situ with contralateral PCNL or pyelolithotomy (2), and unknown reasons (2).

Table 4: Site of encrustation among the study subjects

Preoperative diagnoses included no or minimal encrustation (9 patients), proximal encrustation (1), associated stone disease (7), fragmentation (3), forgotten stent with AKI and renal canaliculi (2), forgotten stent with pyonephrosis (2), and forgotten stent with non-functioning kidney and renal canaliculi (1).

Table 5: Types of procedure performed for DJ removal among the study subjects

Procedures included cystoscopic removal (7 patients), cystolitholapaxy with stent removal (1), URSL with stent replacement (1), antegrade nephroscopy with stent replacement (1), PCNL with stent replacement (2), antegrade nephroscopy with cystolitholapaxy and stent replacement (3), open pyelolithotomy (1), open ureterolithotomy (1), simple nephrectomy (1), and various combinations of PCNL, cystoscopic removal, open pyelolithotomy, and PCN (7 patients).

Fig. 1 – 4

If forgotten, DJ stents, which are indispensible in urological procedures, pose a major challenge to the attending surgeon and to the patient as well. A stent with an indwelling time period of more than 3–6 months can be termed “forgotten” if not intended by the treating doctor⁵. The reasons behind a forgotten or retained stent can be attributed to inadequate counselling by the treating doctor and poor compliance on the part of the patient and his or her family¹

Our study included a total of 25 patients, with ages ranging from 8 to 72 years and a mean age of 39.5 years. In terms of educational status, 17 patients were illiterate, while 8 had received some level of formal education. The indwelling time of the DJ stents varied widely, ranging from 7 to 72 months.In the study by Thapa et al, indwelling time was four months to 10 years⁶.

In our study the clinical presentation of the 25 patients varied, with flank pain being the most common symptom, reported in 10 patients. Three patients presented with irritative lower urinary tract symptoms (LUTS), while one patient was diagnosed with acute kidney injury (AKI). Two patients were asymptomatic at the time of evaluation. Hematuria was observed in 4 patients, and 5 patients exhibited a combination of symptoms, including flank pain, hematuria, and irritative LUTS. Damiano et al.⁷ observed flankpain in 25.3%, irritative bladder symptoms in 18.8%,hematuria in 18.1% and fever in 12.3%, of the patients. Agrawalet al. found storage LUTS was the most common symptom followed by hematuria and flank pain in their study⁵.

The indications for DJ stent placement among the 25 patients varied. Stents were placed following percutaneous nephrolithotomy (PCNL) in 4 patients and ureteroscopic lithotripsy (URSL) in 7 patients. Open pyelolithotomy was the indication in 2 patients, while 1 patient underwent open ureterolithotomy. Emergency conditions, such as pyonephrosis or acute kidney injury (AKI), accounted for 7 cases (1 for pyonephrosis and 6 for AKI). In one patient, a stent was placed on one side following PCNL, while the other side had a stent in situ for renal canaliculi. Similarly, another patient underwent a one-sided pyelolithotomy with the contralateral DJ stent left in situ for renal canaliculi. The indication for stent placement was unknown in 2 patients.

The preoperative diagnosis of the 25 patients revealed varied findings. Nine patients had no or minimal stent encrustation, while 1 patient had encrustation localized to the proximal end of the stent. Seven patients presented with stents associated with stone disease, and 3 patients showed fragmentation of the stent. Two patients were diagnosed with forgotten stents (FS) associated with acute kidney injury (AKI) and renal canaliculi, while another 2 had FS associated with pyonephrosis. One patient had an FS with a non-functioning kidney and renal canaliculi.Of the site of encrustation Takashi Kawahara et al ⁸ observed that   the proximal end was involved in 41.8% compared to 22.1% at the distal end.

In our study the procedures varied based on clinical findings, with cystoscopic stent removal performed in 7 patients and cystolitholapaxy or URSL with stent replacement in 2 patients. Antegrade nephroscopy, with or without cystolitholapaxy, and PCNL with stent replacement were performed in 7 patients. Open surgical interventions, including pyelolithotomy, ureterolithotomy, or nephrectomy, were required in 3 cases. Complex cases involved combinations of PCNL, cystoscopic removal, and open procedures, while 2 patients underwent percutaneous nephrostomy (PCN).A study by Gupta et al⁹ reported management of patients with forgotten DJ stent in 33 patients with endourological procedure [CPE (n=17)], PCNL for proximal renal calculus (n=7), ureteroscopy with pneumatic lithotripsy (n=6) and cystolithotripsy (n=3). Two patient required nephrectomy.20  Nerli et al retrospectively reviewed a series of 14 children with forgotten/retained DJ ureteric stents and reported multimodal approach for removal of forgotten DJ stent. They used a combination of ESWL, cystolitholapaxy and PCNL to free the DJ stent and extract it.¹⁰ In a recently published study, management of the ureteral stents and related stones were successfully done by combined endourologic techniques to achieve a stone-free state in all patients except for patient with 110 months of forgotten stent time in whom nephrectomy was performed for a nonfunctioning kidney related to the forgotten stent¹¹.

Management of forgotten DJS is time consuming, difficult, complicated, risky, and costly.Forgotten DJ stents can't be prevented. On the urologist part, patients should be properly counselled by the treating physician. Various strategies like maintaining DJ stent registry, text messaging to the patients have been adopted but all are not adequate for completely eliminating this phenomenon.Patient compliance is also important in this regard. Further studies are needed in future to know the actual incidence as our sample size was very small and final stone analysis was not performed to study the type of stone encrustation.Forgotten Double-J stents represent a significant yet preventable complication in urological practice, often leading to severe morbidity if not promptly addressed. Our evaluation highlights that timely identification and intervention are crucial in preventing the progression of complications such as encrustation, stone formation, recurrent infections, and renal impairment. The management of these cases may necessitate a combination of endourological techniques, shockwave lithotripsy, or even open surgical approaches, depending on the extent of stent encrustation and associated complications. The findings underscore the importance of implementing robust follow-up protocols and patient education to minimize the risk of stents being forgotten. Utilizing digital tracking systems, scheduled reminders, and patient awareness initiatives can play a pivotal role in reducing incidences of stent retention. By Emphasizing a multidisciplinary approach and proactive patient engagement, we can improve patientoutcomes and decrease the healthcare burden associated with managing forgotten DJ stents. Future research should focus on innovative stent designs, such as biodegradable materials and smart stent technologies, which may further reduce the risk of stent-related complications and improve patient compliance. As urological practice evolves, a proactive approach to stent management remains essential to optimizing patient safety and care.

1. Monga M, Klein E, Castaneda-Zuniga WR,Thomas R. The forgotten indwelling ureteral stent: a urological dilemma. Urology 1995; 153: 1817-20.
2. Saltzman B. Ureteral stents. Indications, variations, and complications. Urol Clin North Am 1988;15:481-91.
3. Ekrem G, Kamil SK. Comparison of two different        scoring  systems in encrusted ureteralstent              management:     A Single-center experience. Urol J 2020;17:248-51.
4. Monga M, Klein E, Castañeda-Zúñiga WR, Thomas R. The forgotten indwelling ureteral stent:A urological dilemma.  J Urol1995;153:1817-9.
5. Agarwal S, Sarpal R, Pathak P, Biswas M, Mittal A, Rathore K, et al. Tricks and tacks in the management of the forgotten double J stent. Int Surg J. 2018; 26: 792.
6. Thapa BB, Thapa N, Bhandari BB. Fate of forgotten DJ stent. Med J Shree Birendra Hosp. 2018;17(2):38-43.
7. Damiano R, Olivia A, Esposito C, Desio M, Autorino R, D'Armiento M (2002) Early and late complications of double pigtail ureteral stent. Urol Int 69:136-140
8. Takashi K., Hiroki Ito, Hideyuki Terao, et.al. Ureteral Stent Encrustation, Incrustation, and Coloring: Morbidity Related to Indwelling Times. Jr Endourology 2012:26: 213-14.
9. Gupta R, Gupta A, Anand A, Azad T. Forgotten DJ stent a nagging problem-management and long term follow up. JK Sci. 2017;19:110-4.
10. Nerli RB, Magdum PV, Sharma V, Guntaka AK, Hiremath MB, Ghagane S. Forgotten/retained double J ureteral stents: A source of severe morbidity in children. Afr J Paediatr Surg. 2016;13:32-5.
11. Adanur S, Ozkaya F. Challenges in treatment and diagnosis of forgotten/encrusted double-J ureteral stents: The largest single-center experience. Ren Failure. 2016;38:920-6.