The aim of this study is to evaluate the role of stellate ganglion blockade (SGB) for preserving arteriovenous fistula in hemodialysis patients undergoing major lower limb orthopedic surgery.

The best way for dialysis in chronic renal failure (CRF) patients with consideration of feasibility, rate of infection, and patency is hemodialysis by using native access by using arteriovenous fistula (AVF).

Altered calcium and phosphor metabolism in CRF patients would also increase vascular reactivity. Stellate ganglion blockade (SGB) has been used for several years for both diagnosis and treatment of circulatory problems in upper extremity. Recently preemptive SGB has been used in prevention of radial artery spasm in coronary artery patients.

SGB increases blood flow and decrease vascular resistance in the arm. SGB prevents or ameliorates the reactivity of the muscular layer of the RA in response to both surgical manipulation during harvesting the artery and to the potent vasoconstrictor mediators released during surgery

Inclusion Criteria:

• Age 21 to 75 years.
• Both sexes.
• American Society of Anesthesiologists (ASA) physical status III.
• Chronic renal failure (CRF) patients.
• Undergoing major lower limb orthopedic surgery.

Exclusion Criteria:

• Psychiatric disorders.
• History of substance abuse.
• Ipsilateral brachial and radial artery stenosis.
• Allergy to local anesthetics.
• Cardiovascular and respiratory disorders.
• Coagulopathy.
• Use of vasoactive medications.
• Obesity (body mass index >30 kg/m2).
• Smoking.

The data will be available upon a reasonable request from the corresponding author after the end of study for one year.

After the end of study for one year.

The data will be available upon a reasonable request from the corresponding author.