# Complications in IR: Recognition and Management

## Introduction

Interventional radiology procedures, while minimally invasive, carry inherent risks of complications. **Early recognition, prompt management, and transparent reporting** are the hallmarks of a safe IR practice. Understanding the classification, prevention, and management of complications is essential for every IR trainee and practitioner.

## SIR Adverse Event Classification

### By Severity

| SIR Class | Severity | Description |
|-----------|----------|-------------|
| A | Minor | No therapy required; no consequence |
| B | Minor | Nominal therapy, no consequence; includes overnight observation |
| C | Major | Requires therapy, minor hospitalization (<48 hours) |
| D | Major | Major therapy, extended hospitalization or ICU admission |
| E | Major | Permanent adverse sequelae |
| F | Major | Death |

**Minor complications**: require no therapy (A) or nominal therapy with no consequence (B); includes overnight admission for observation. **Major complications**: require therapy with minor hospitalization (< 48 hours) (C), major therapy with extended hospitalization or ICU (D), permanent adverse sequelae (E), or death (F). This classification system facilitates standardized **quality reporting** and benchmarking.

### By Timing

**Immediate**: during or within 24 hours of the procedure. **Early**: 1-30 days post-procedure. **Late**: beyond 30 days.

## Vascular Complications

### Access Site

**Hematoma**: most common; manage with manual compression; large hematomas may require surgical evacuation. **Pseudoaneurysm**: pulsatile mass at access site; diagnosed with ultrasound; treat with **ultrasound-guided thrombin injection** (90-95% success) or covered stent if large. **Arteriovenous fistula**: continuous bruit at access site; most resolve spontaneously; may require covered stent or surgical repair. **Retroperitoneal hemorrhage**: from high femoral puncture above the inguinal ligament; presents with flank pain, hypotension, falling hemoglobin; CTA to diagnose; may require embolization or surgery.

### Vessel Injury

**Dissection**: intimal flap creation from catheter or wire manipulation; manage with stent placement if flow-limiting. **Perforation/Rupture**: acute extravasation; manage with balloon tamponade, covered stent, or surgical repair. **Thrombosis**: in-situ clot formation; treat with aspiration thrombectomy, thrombolysis, or surgical thrombectomy. **Embolization (non-target)**: embolic material reaching unintended vessels; consequences depend on end-organ.

![Vascular access site complication recognition and management](images/vascular-complications.png)

## Non-Vascular Complications

### Infection

**Abscess**: at the procedure site or in targeted organs; managed with antibiotics and drainage. **Bacteremia/Sepsis**: from manipulation of infected fluid collections or contaminated biliary/urinary systems; prophylactic antibiotics reduce risk. **Device infection**: tunneled catheters, ports, stents; may require device removal and antibiotics.

### Organ Injury

**Pneumothorax**: from lung biopsy, thoracic procedures, or central line placement; small pneumothorax may observe; large or symptomatic requires chest tube. **Bowel perforation**: from percutaneous abdominal procedures; present with peritonitis; may require surgical repair. **Non-target organ infarction**: from embolization procedures; minimize with superselective technique.

### Contrast-Related

**Allergic reaction**: urticaria (mild) to anaphylaxis (severe); treat per severity (diphenhydramine, epinephrine, steroids). **Contrast-induced nephropathy (CIN)**: rise in creatinine > 0.5 mg/dL or 25% from baseline within 48-72 hours; prevent with hydration, minimize contrast volume, avoid nephrotoxins. **Contrast extravasation**: subcutaneous infiltration of contrast from IV; warm compresses, elevation; compartment syndrome is rare but serious.

## Procedure-Specific Complications

### Biliary Interventions

**Cholangitis**: from biliary manipulation; pre-procedural antibiotics and adequate drainage reduce risk. **Bile leak/biloma**: from transgression of the biliary system; manage with percutaneous drainage. **Hemobilia**: from hepatic artery-biliary fistula; may require embolization.

### Embolization Procedures

**Post-embolization syndrome**: fever, pain, nausea, leukocytosis; expected after uterine, hepatic, and splenic embolization; self-limited; manage with NSAIDs and antiemetics. **Non-target embolization**: the most feared complication; prevent with meticulous catheter positioning and angiographic evaluation. **Organ failure**: hepatic failure after TACE, renal failure after renal embolization; risk stratification is critical.

### Drainage Procedures

**Catheter dislodgement**: secure catheters with locking pigtail, suture, or adhesive device. **Drain occlusion**: from viscous fluid or debris; flush and exchange as needed. **Fistula formation**: persistent communication between drained cavity and adjacent structures.

![Procedure-specific complication recognition guide](images/procedure-specific-complications.png)

## Prevention Strategies

**Preprocedural planning**: review imaging, assess coagulation, optimize patient. **Technique**: meticulous catheter and wire handling, fluoroscopic/ultrasound guidance, superselective embolization. **Checklists and timeouts**: standardized verification of patient, procedure, site, and equipment. **Antibiotic prophylaxis**: per SIR guidelines for specific procedures (biliary, genitourinary, device implantation). **Post-procedural monitoring**: appropriate observation period; clear discharge criteria.

## Complication Reporting and Quality Improvement

**Morbidity and mortality (M&M) conferences**: regular review of adverse events in a non-punitive environment. **SIR quality improvement guidelines**: published complication thresholds for common procedures. **Root cause analysis**: for serious adverse events to identify system and process failures. **NSQIP and institutional databases**: track outcomes for benchmarking and improvement. Culture of **transparency and learning** rather than blame.

## Emergency Management

**Massive hemorrhage**: activate massive transfusion protocol; obtain hemostasis (balloon tamponade, covered stent, embolization). **Anaphylaxis**: epinephrine 0.3-0.5 mg IM (first line); IV access, fluids, steroids, H1/H2 blockers. **Cardiac arrest**: initiate ACLS; defibrillation for shockable rhythms; document and debrief. **Tension pneumothorax**: immediate needle decompression followed by chest tube. Emergency equipment must be **checked daily** and immediately accessible in every IR suite.

![IR emergency management protocols](images/ir-emergency-protocols.png)

## Key Clinical Pearls

SIR adverse event classification (A-F) provides a standardized framework for complication reporting and quality improvement. Ultrasound-guided thrombin injection is first-line for femoral pseudoaneurysms with a success rate exceeding 90%. Post-embolization syndrome is an expected outcome, not a complication; educate patients preoperatively. Prevention through meticulous preprocedural planning, intra-procedural technique, and post-procedural monitoring is the best complication management. A culture of transparent reporting and non-punitive M&M conferences drives continuous improvement.

## References

1. Defined the Core Practice Standards. *Defined Core Practice. Sacks D, McClenny TE, Cardella JF, Lewis CA. SIR Clinical Practice Guidelines for Quality Improvement*. *JVIR*. 2003;14(9 Pt 2):S199-S202.
2. Defined the Core Practice Guidelines. *Defined Core Practice. Defined Core Clinical Practice. Defined Core Competencies. Defined Core Practice Guidelines. Defined Core Updates. ACR-SIR Practice Parameter for Reporting Complications*. 2020.
3. Defined the Core Practice Standards. *Defined Core Practice. Defined Core Clinical Practice. Defined Core Competencies.* *Defined Core Practice Guidelines.* *Defined Core Updates.* *Defined Core Clinical Practice Standards. JVIR Quality Improvement Guidelines*. 2019.
4. Defined the Core Practice Standards. *Defined Core Practice. Defined Core Clinical Practice. Defined Core Competencies.* *Defined Core Practice Guidelines.* *Defined Core Updates.* *ACR Contrast Manual v2023*. 2023.