In the available literature, there is a lack the risk categorization of infectious complications after RIRS with subsequent recommendation as regard to AP in different risk patients. Therefore this study is planning to investigate the optimal protocol for AP prior to RIRS in high-risk population through comparing the enhanced regimen (2days) vs. the extended regimen (7 days) in a randomized controlled trial (RCT).

Retrograde intrarenal surgery (RIRS) has gained a wide popularity in the management of renal stones due to tremendous technological advancements over the last years. According to the current guidelines, RIRS could be offered as a first line surgical treatment option for renal stones less than 20 mm (or ≤ 10 mm for lower pole stone/s) with favorable stone free rate (SFR).

Despite being a minimally invasive, several morbid complications could be encountered during/after RIRS. Post-operative infectious complications constitute one of the major reported complications after RIRS with varying presentations which include urosepsis, febrile urinary tract infection (UTI) and asymptomatic bacteriuria.

Several large-populations studies have reported the incidence of infectious complications post-RIRS. Among ≈ 12.000 patients undergoing ureteroscopy and were evaluated by The Clinical Research Office of Endourological Society (CROES), post-operative fever, UTI and urosepsis were reported in 1.8%, 1.3% and 0.3%, respectively. Moreover, in another report by Reducing Operative Complications from Kidney stones (ROCK) for 1.817 patients undergoing RIRS, 2.4% required hospital readmission (HR) for infectious complications.

The underlying mechanisms of infectious complications post-RIRS include combination of existing bacteria in the urinary tract and rising intrarenal pressure due to prolonged and/or vigorous irrigation. In addition, several studies have investigated the independent predictors of infectious complications after RIRS with identified positive preoperative urine culture or prior history of recurrent UTI, long-lasting indwelling ureteral stents, diabetes mellitus (DM) and immunocompromised patients.

In addition to the substantial patient morbidity, post-operative infectious complications constitute a major burden to the health care resources. Therefore, minimizing these devastating events should an important consideration by health care providers not only for improving the patient satisfaction but also for cost-saving issues. Therefore, it is a crucial entity for clinicians to identify high-risk patients for post-RIRS infectious complications and to exhaust the different clinical mitigations to minimize these events.

According to American Urological Association (AUA) Best Practice Statements on Antibiotic Prophylaxis (AP), single dose of perioperative antibiotics is indicated for all cases prior to RIRS. However, the exact regimen and duration of preoperative AP for high risk patients for infectious complication are still undefined.

In previous studies on AP for high risk patients prior to percutaneous nephrolithotomy (PCNL), different protocols were compared as regard to its impact on infectious events after PCNL. Despite the reported advantage of the extended regimen on minimizing the infectious events, the drawbacks of prolonged antibiotics as untoward adverse events (AEs) and drug resistance should be considered.

Inclusion Criteria:

• Ability to give informed consent.
• Age ≥18 years.
• Renal stone <20 mm in which RIRS is recommended.
• High susceptibility of post-procedural infectious complications by one or more of the followings: - Positive preoperative urine culture within 12 weeks of the planned intervention. -Indwelling ureteral stents for more than 4 weeks. -Diabetes mellitus.

Exclusion Criteria:

• Solitary kidney.
• Chronic kidney disease.
• Pregnant.
• Have received antibiotics within 7 days prior to enrollment.