SIRS post RIRS: Do’s and Don’ts?

Retrograde intrarenal surgery (RIRS) is a well-established, minimally invasive approach for

managing renal stones less than 2 cm. With experience and advancements such as negative

pressure RIRS (NP RIRS), this has been extended for stones up to 3 cm. Despite its safety and

efficacy, the risk of systemic inflammatory response syndrome (SIRS) following RIRS remains

significant, with reported rates up to 20%.( 1 ) Additionally, sepsis and septic shock occur in

0.5–11.1% and 0.3–4.6% of patients, respectively.( 2 ) A variety of patient- and surgery-related factors contribute to the development of postoperative infectious complications. Patient-related risk factors include diabetes mellitus, female gender, renal anomalies, positive preoperative urine cultures, indwelling ureteral stents placed for more than 30 days, stent placement for a septic episode, larger stone burden (mean >17.5 mm), and higher CT stone density (>730 HU).( 2 ) Surgical factors such as prolonged operative time (>60 minutes), high irrigation pressures exceeding 80 mmHg, and positive stone cultures also increase the risk.( 3 , 4 ) Among these, surgical duration, stone size, and density are considered independent

predictors of infectious complications.( 2 ) Infection during RIRS cannot be entirely avoided, as bacterial colonization and endotoxin release during fragmentation, especially under high-pressure irrigation, even with a ureteral access sheath,can lead to systemic dissemination due to absorption of bacteria and toxins through venous and lymphatic pathways.( 5 )

Do’s:

• Use culture directed antibiotic prophylaxis in cases with positive urine culture.

• Maintain irrigation flow ≤25 ml/min to limit intrarenal pressure.

• Stage procedures for bilateral stones or high stone burden.

• Consider negative pressure ureteral access sheath (NUSA), which has demonstrated significantly

• lower infection (2.92%) and sepsis (0.58%) rates than standard RIRS. ( 6 )

Don’ts:

• Avoid surgery if blood glucose >400 mg/dL, as per AUA guidelines.

• Avoid preoperative stenting >30 days, despite its procedural benefits.

• Ratio of endoscope to sheath diameter (RESD) should not be >0.75 (in traditional RIRS ) or >0.85 ( in NP – RIRS) which can elevate intrarenal pressure.(7)

• Avoid reusing disposable scopes (RDS) without doing high-level cleaning and sterilization as a cost-conscious approach due to high postoperative fever and residual fragments

• By adhering to these best practices, urologists can significantly reduce the incidence of infectious complications following RIRS.