Renal infarction

Background

• Low ED incidence, approximately 1 per 90 to 100, 000 visits a year
• Diagnosis frequently missed due to mimicking symptoms similar to other more frequent complaints such as pyelonephritis and nephrolithiasis
• Caused by interruption of blood supply to kidney

Major causes

• Cardioembolic disease
• Renal artery injury
• Hypercoagulable state
• Dissection
• Vasculitis

Clinical Features

• Flank pain
• Nausea, vomiting
• Sudden onset

Differential Diagnosis

Flank Pain

• Vascular
  • Abdominal aortic aneurysm
  • Renal artery embolism
  • Renal vein thrombosis
  • Aortic dissection
  • Mesenteric ischemia
• Renal
  • Pyelonephritis
  • Perinephric abscess
  • Perinephric hematoma
  • Papillary necrosis
  • Renal cell carcinoma
  • Obstructive uropathy
    • May or may not be due to nephrolithiasis
  • Renal infarction
  • Renal hemorrhage
• Ureter
  • Nephrolithiasis
  • Blood clot
  • Stricture
  • Tumor (primary or metastatic)
• Bladder
  • Tumor
  • Varicose vein
  • Cystitis
• GI
  • Biliary colic
  • Pancreatitis
  • Perforated peptic ulcer
  • Appendicitis (appendix may be pushed to RUQ in pregnancy)
  • Inguinal Hernia
  • Diverticulitis
  • Cancer
  • Bowel obstruction
• Gynecologic
  • Ectopic Pregnancy
  • PID/TOA
  • Ovarian cyst
  • Ovarian torsion
  • Endometriosis
  • Mittelschmerz or benign ovulatory pain
• GU
  • Testicular torsion
  • Epididymitis
• Other
  • Shingles
  • Lower lobe pneumonia
  • Retroperitoneal hematoma, abscess, or tumor
  • Epidural abscess
  • Epidural hematoma
  • Rib contusion/fracture

Evaluation

Laboratory

• CBC with differential, CMP, LDH, urinalysis, urine culture
• EKG- to evaluate for arrhythmia

Imaging

• CT with IV contrast (preferred study)
• Renal ultrasound - less senstive
• MRI with gadolinium (contraindicated with severe renal impairment due to risk of nephrogenic systemic fibrosis)
• Radioisotope scan - not commonly used

Management

• No clinical guidelines available, but mainstays of therapies include anticoagulation and endovascular therapy
• Endovascular therapy (thrombolysis/thrombectomy/angioplasty)
  • Indicated if acute occlusion involving main renal artery or segmental branches
  • Greatest likelihood of benefit if performed early
• Anticoagulation:
  • IV Heparin followed by oral Coumadin
  • Indicated in patients with renal infarction in the setting of Atrial fibrillation, LV thrombus, and hyper coagulable state

Disposition

• Admit