Evidence-based risk factors for complications and reoperations in inguinal hernia surgery have been defined as:
1. Age >80 years: high mortality risk with existing comorbidities; more seromas, urinary retention, and readmissions. Even at age > 60 years, more urinary retention and complications.
2. ASA III and higher: more complications and reoperations, increased mortality risk.
3. Female gender: increased risk for pain
4. Obesity: tendency towards more complications
5. COPD: more complications, increased mortality in outpatient surgery.
6. Diabetes mellitus: independent risk factor for postoperative complications
7. Anticoagulation/antiplatelet agents: 4-fold increased risk of postoperative bleeding. Even after discontinuation of anticoagulant medication, the risk of rebleeding is significantly increased.
8. Immunosuppression/corticosteroid medication: increased risk of recurrence
9. Liver cirrhosis: significant increase in complication rates
10. Nicotine abuse: significant increase in general and surgical complication risk.
11. Bilateral inguinal hernia: increased perioperative risk, therefore no prophylactic operation on a healthy side.
12. Increased complication rate in recurrent procedures and femoral hernias.
13. Preoperative pain often leads to acute and then chronic groin pain postoperatively.