Discussion 
Systemic arteriovenous fistulas (AVF) are rare but correctable vascular abnormalities usually occurring following catheterization procedures, surgery, trauma, or aneurysms; Spontaneous fistulas have occasionally been described (10). There are cases reports of spontaneous arteriovenous fistulas on different vessels in the absence of triggering cause, subclavian artery and vein(10), superficial femoral artery and vein (11), left common iliac artery and vein (12) and popliteal artery and vein (4). The cause of spontaneous AVF formation may remain unknown and may need further study. Causes of AVF can be categorized irrespective of the vessel involved (Figure 2) for a simplified approach. Spontaneous arteriovenous fistulas are rare in clinical activity with very limited reports in the literature but it is crucial to diagnose it promptly to prevent further complications including complications including aneurysm, thrombus formation, and limb ischemia.
There has been a case report of spontaneous superficial femoral artery to femoral vein fistula in a 71-year-old female patient known to have multiple sclerosis in the background after her presentation with acute limb ischemia (11). There is a report of AVF in the right lower limb following HIV arthritis (3). Spontaneous right leg popliteal AVF had also been reported in a 79-year-old female where the cause remained unclear (4). The patient presented in this article had chronic kidney disease (CKD) on the background of hemodialysis (HD) for 2 years. The clinical correlation between CKD and/or HD remains unknown but the CKD, HD, uremia, and vasculopathy genes may contribute to the formation of AVF through different mechanisms including vascular shear stress force, blood stasis, and cellular immunity dysfunction or their synergy (13, 14).  In conclusion, spontaneous arteriovenous fistula (AVF) could occur as sequelae of chronic kidney disease or hemodialysis but other common causes need to be excluded. Though there is a report of spontaneous AVF, generally AVF needs intervention (5, 6, 15).
Conclusion : spontaneous arteriovenous fistula could occur as sequelae of chronic kidney disease or hemodialysis but other common causes need to be excluded