The Micro-hole Zone Technology as a new era in urinary drainage: a narrative review from bench to bedside

Introduction: Intermittent catheterization (IC) remains the standard of care for patients who are unable to empty their bladder. However, incomplete bladder emptying and urinary tract infections (UTIs) can persist, leading to complications such as recurrent infections, episodes of hospitalizations, and decreased quality of life. The Micro-hole Zone Technology (MHZT) catheter (Luja™) represents an innovative catheter design that aims to address known mechanical risk factors for UTI by minimizing flow-stops, mucosal microtrauma, and residual urine, all key contributors to infection risk. Method: A scoping literature search was performed in PubMed and Google Scholar to identify all preclinical, clinical, and patient-reported outcome (PRO) studies evaluating the MHZT catheter (Luja). To contextualize its performance, findings were systematically compared with conventional two-eyelet catheters (CEC) across the same endpoints. The co-primary endpoints were (1) frequency of flow-stops and (2) residual urine volume at first flow-stop (RV1). Secondary endpoints included intracatheter pressure peaks, haematuria, and PRO measures related to comfort, ease of use, and perceived completeness of bladder emptying. Results: Preclinical studies demonstrated significantly fewer flow stop with the MHZT (0% vs. up to 80% with CEC), markedly reduced residual volume at first flow-stop (mean 3.6 ± 3.9 mL vs. 38.1 ± 26.7 mL; p < 0.001) and lower intraluminal pressure peaks (− 42 ± 11 vs. − 132 ± 7 mbar; p < 0.001). From summarized data across randomized controlled trials (n > 250), catheterizations with Luja resulted in zero flow-stops and complete emptying at first flow-stop (RV1 < 10 mL) > 87% of the times compared to approximately 50% for CEC. PRO data from > 3,400 users indicated improved confidence in complete emptying, easier use and less worry for UTIs. Conclusion: By triangulating evidence across preclinical, clinical, and PRO studies, this review demonstrates that the MHZT/Luja catheter significantly improves bladder drainage compared with conventional designs, reducing flow-stops, residual urine, and urothelial trauma. Given that infection remains one of the most frequent IC complications, Luja offers a promising approach to lowering UTI risk factors. Enhanced user experience and confidence in complete emptying further support its potential clinical benefit.