Commonest cause of AV fistula is?

RUHS, Jaipur, M.Sc Nursing Entrance Exam-2021

Medical & Surgical Nursing

Easy

Appeared in: RUHS, Jaipur, M.Sc Nursing Entrance Exam-2021

Explanation

Iatrogenic causes are the most common reason for AV fistula formation in modern healthcare.
This includes both unintentional complications from procedures like arterial catheterization and intentional surgical creation for hemodialysis access.
The increasing volume of invasive diagnostic and therapeutic vascular procedures has made iatrogenic injury the leading etiology.
Surgically created AV fistulas for dialysis are a prime example of a planned iatrogenic fistula, contributing to its high prevalence.

Option A: Congenital AV fistulas are developmental abnormalities present at birth. While they do occur, they are significantly rarer than acquired fistulas.
Option B: Traumatic causes, such as penetrating injuries, were historically the most common cause. However, in modern civilian practice, they have been surpassed by iatrogenic causes.
Option D: Erosion of a tumor into adjacent blood vessels is a possible but very rare mechanism for fistula formation.

Clinical Relevance

Nursing practice connection: This is primarily an exam-oriented knowledge point with limited direct bedside application, so retain Etiology of Arteriovenous Fistula as background academic context rather than a clinical decision trigger.
Nurses play a crucial role in monitoring patients after procedures like cardiac catheterization or arterial line placement. Key assessments include checking the puncture site for a new bruit or thrill, which could indicate the formation of an iatrogenic AV fistula.
For patients with chronic kidney disease, nurses manage and assess surgically created AV fistulas used for hemodialysis. This involves checking for the presence of a thrill and bruit ('feel the thrill, hear the bruit') to ensure the fistula is patent and functioning.
What if? If a patient develops a new, loud bruit and palpable thrill at a femoral artery puncture site post-angiogram, the nurse's priority is to notify the physician immediately. This suggests an iatrogenic AV fistula, which may require intervention to prevent complications like high-output heart failure or limb ischemia.

How to Approach the Question

First, understand the question is asking for the 'commonest' cause, which implies a comparison of frequencies.
Define 'AV fistula': an abnormal connection between an artery and a vein.
Analyze the options: 'Congenital' (from birth), 'Traumatic' (from injury), 'Iatrogenic' (from medical treatment), and 'Tumor erosion'.
Consider modern medical practice. There has been a huge increase in invasive procedures (like catheterizations) and the use of surgically created fistulas for dialysis.
This trend makes 'Iatrogenic' a very strong candidate for the most common cause, surpassing historical causes like trauma.
Conclude that iatrogenic causes, encompassing both accidental and intentional fistula creation, are the most frequent in the current era.

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