Recreational ketamine use has increased substantially in recent years and is associated with ketamine-induced uropathy (KIU), characterised by severe lower urinary tract symptoms (LUTS), pain and haematuria[1]. Although symptom resolution may occur after ketamine cessation, a subset of patients develops persistent symptoms due to bladder ulceration. These ulcerative lesions macroscopically resemble Hunner lesions observed in interstitial cystitis, for which endoscopic coagulation is known to improve symptoms[2].
We hypothesised that laser coagulation of bladder ulcers in KIU results in similar symptom improvement. This study aimed to evaluate short- and long-term patient-reported outcomes (PROs) following laser coagulation of bladder ulcers in KIU.

A retrospective cohort study was conducted including patients with cystoscopically confirmed bladder ulcers due to KIU who underwent laser coagulation after ≥3 months abstinence from ketamine. Patients with prior urological surgery or concurrent intravesical botulinum toxin were excluded. 
PROs were collected using standardised questionnaires preoperatively and after 3 and 12 months. Outcomes were categorised as resolved, improved, unchanged, or deteriorated. Primary outcome measures were the overall change in symptoms after 3 months and the change in pain after 12 months.   Secondary outcomes included change in daily micturition frequency and postoperative complications (Clavien-Dindo).
Normality testing was performed using Shapiro–Wilk tests. As data were non-parametric, Wilcoxon signed-rank tests were used for paired comparisons.

A total of 63 patients were included.  After 3 months, 10/63 patients (15.9%) reported complete symptom resolution and 38/63 (60.3%) reported improvement, resulting in 76.2% reporting overall benefit. Eleven patients (17.5%) reported no change and 2 (3.2%) reported deterioration.
Forty-two patients completed the 12-month follow-up. Complete pain resolution was reported by 24/42 patients (57.1%) and improvement was reported by 11/42 (26.2%), with 83.3% reporting overall benefit. 2/42 (4.8%) underwent cystectomy due to persistent symptoms or progression of bladder deterioration.
After 3 months, median daily micturition frequency had decreased from 18 (IQR 15-32) voids per day preoperatively to 9 (IQR 8-12) voids per day (p < 0.001 )
Postoperative complications occurred in 5/63 patients (8.0%), predominantly minor (Clavien-Dindo grade I–II). In one patient (1.6%) bladder perforation occurred due to simultaneous bladder biopsy, requiring surgical closure (grade IIIb).

Laser coagulation of bladder ulcers in KIU is associated with substantial and sustained improvement in PROs, particularly pain and storage LUTS. The high proportion of patients reporting pain resolution at 12 months suggests a durable and potentially progressive treatment effect over time.    The significant reduction in median daily micturition frequency further supports a clinically relevant improvement in bladder function.
These findings are important, as there are few minimal invasive treatment options for patients who have persistent symptoms after ketamine cessation. The observed outcomes are consistent with those reported following endoscopic treatment of Hunner lesions in interstitial cystitis.
Importantly, this study reflects real-world clinical practice, including patients with variable adherence to ketamine abstinence, which enhances the generalisability of the findings. At the same time, several limitations must be considered. The retrospective design and absence of a control group hinders proving a causal relation. Incomplete follow-up at 12 months and the potential for follow-up bias may have led to an overestimation of treatment effect.
Furthermore, the reliance on patient-reported outcomes without systematic objective assessment may be considered a limitation. However, given that KIU is a symptom-driven condition, PROs arguably represent the most clinically relevant measure of treatment success.

Laser coagulation may provide effective and durable symptom relief in patients with KIU-related bladder ulcers. These findings support its role as a treatment option, although prospective controlled studies are required.

Chang, T., et al., Ketamine-Induced Uropathy: A New Clinical Entity Causing Lower Urinary Tract Symptoms. Low Urin Tract Symptoms, 2012. 4(1): p. 19–24.
Ko, K.J., et al., Comparison of the Efficacy Between Transurethral Coagulation and Transurethral Resection of Hunner Lesion in Interstitial Cystitis/Bladder Pain Syndrome Patients: A Prospective Randomized Controlled Trial. Eur Urol, 2020. 77(5): p. 644–651.