Hemodialysis Access

Functionally patent hemodialysis access is achieved by:

• Open surgical AVF and AVG in the upper extremity
• Open surgical AVF and AVG in the lower extremity
• Fistulogram, with or without intervention
• Revision surgery for dialysis access associated steal syndrome (e.g., DRIL, PAI, RUDI, banding), venous outflow occlusion, or aneurysm.
• ​​​Percutaneous AVF creation

Patient History

A thorough history should be obtained, and physical examination performed on all patients before creation of an AVF or AVG or any revision procedures. The evaluation should focus on arterial inflow, possible superficial veins that can be used for cannulation of an AVF, possible recipient outflow veins for an AVG, and central venous outflow.

Review of previous operative reports, chest radiographs, venograms, and CT scans can also assist in characterizing possible impediments like indwelling vascular stents or devices, central venous stenotic lesions, or previous arteriovenous access attempts.

Physical Examination

The nondominant arm is preferred for AVF/AVG placement. Creating the access in the patient’s nondominant arm allows the dominant arm to be used during hemodialysis treatments. Furthermore, in the rare event of a disabling complication, the dominant arm would be spared.

Physical exam should focus on an evaluation of distal pulses on the extremity of interest in addition to surgical scars that may be present and that may suggest unfavorable anatomy that can render surgery more challenging.¹⁵⁴An Allen test should also be performed test to evaluate completeness of the palmar arch.

From the perspective of obtaining a functional AV access, an examination for heart failure is mandatory. Poor cardiac output or ejection fraction may affect the success of the AV access that is created (e.g., low output may increase risk of maturation failure).¹⁵⁵

Imaging

Preoperative duplex mapping of the upper extremity veins and arteries focusing on vein diameter and artery patency should be performed prior to surgery. Occasionally, venography can be helpful in order to identify central venous lesions that may need to be avoided or that may require treatment.

An ECG and chest X-ray are also typically required.

Medical Management and Lifestyle Changes

Smoking is associated with poorer outcomes in ESRD patients, and it should be discouraged. ESRD patients should be managed aggressively regarding their comorbid conditions to assist in healing of surgical wounds and maturation of access.

The use of adjuvant clopidogrel to enhance AVF maturation after surgery has not been shown to be efficacious and is not encouraged.¹⁵⁶Similarly, the routine use of fish oil or aspirin to prevent AVF flow dysfunction has not been shown to improve outcomes.¹⁵⁷

On the other hand, primary AVG patency can be improved with the use of aspirin/dipyridamole as well as fish oil.^{158, 159}

Use of anticoagulants in this population should be approached cautiously due to the risk of bleeding potentially compounding the elevated baseline risk that this population carries.¹⁶⁰

Risk Stratification for Surgery (cardiac and pulmonary)

Risk stratification for surgery is needed if the patient requires general anesthesia. While most AV access surgery can be performed with local or regional anesthetic, general anesthetic is occasionally needed.

Conduct preoperative anesthesia evaluation as per societal guidelines. The timing of the procedure may depend on the preexisting dialysis schedule.

Dialysis immediately preoperatively may be necessary to correct volume status and electrolyte disturbances. Thus, temporary dialysis catheter placement may be necessary. Close coordination with the patient’s nephrologist and dialysis unit should be universal.

Regarding percutaneous procedures, a fistulogram is nearly always performed with local anesthetic and sedation and is only minimally invasive. As such, routine pre-procedural risk stratification is not necessary.

Risk Assessment

A multidisciplinary approach to care can optimize outcomes. Medical specialists and team members can assist patients with risk factor modification, such as smoking cessation, maintaining glycemic control, normalizing blood pressure and lipid levels, maintaining antiplatelet therapy, thereby promoting a positive patient experience. Discharge planning should also be considered at the time of surgical planning, with the goal being same day discharge. Coordination of care with the patient’s nephrologist and dialysis unit should be an integral part of the care of patients with ESRD.⁷

Preoperative Labs

For all dialysis access surgeries or percutaneous procedures, the most important laboratory value that should be assessed preoperatively is the serum potassium level, which is frequently elevated in patients with chronic or end-stage kidney disease. Hyperkalemia may rise to dangerous levels if a patient requires general anesthesia. Active infection, as reflected by an elevated leukocyte count, should be investigated, and surgery delayed until after the infection has resolved.

A coagulation panel, including an INR should be obtained prior to surgery. Patients who are anticoagulated should hold their anticoagulation and have an INR less than 1.5 prior to surgery. Regarding percutaneous procedures, a fistulogram can be performed safely with INR as high as 2.5. Percutaneous AVF creation should not be performed unless the INR is less than 1.5, due to the possible need for immediate surgical conversion.

Preoperative Medication Adjustment

Optimization of blood pressure may enhance maturation success. Severe hypertension should be addressed in order to achieve normotension. Conversely, overzealous use of anti-hypertensives may lead to hypotension, which in extreme circumstances, can lead to immediate access failure. Midodrine can be used to treat chronic hypotension. Patients on anticoagulation with heparin infusion should have the infusion held prior to procedure.

• Perioperative antibiotics: Prophylactic antibiotics for open procedures should be considered perioperatively as for any other surgery.
• Anticoagulation and its reversal: If the patient is on oral anticoagulation preoperatively, it should be discontinued before the procedure in order to minimize the risk of bleeding complications. DOAC should be held for 48-72 hours before procedure. Warfarin should be discontinued 3-5 days in advance. Consider bridging with parenteral anticoagulation (UFH) in appropriate patients with high thrombosis risk.
• Allergy: Patients with allergy to intravenous iodinated contrast and scheduled for angiography or fistulography should be premedicated with prednisone 50 mg in 3 oral doses at 13 hours, 7 hours, and one hour prior to procedure. Diphenhydramine 50 mg can be given one hour prior to the procedure. Rescue dosing with IV solumedrol or Decadron can be used as needed. CO2 venography can also be considered.

• ACE Inhibitors: If significant volume depletion is anticipated, ACE inhibitors and angiotensin receptor antagonists can be held on the morning of surgery. These agents can be restarted after the procedure, once euvolemia has been achieved.
• Diabetes Mellitus: Metformin should be held at the time of administration of contrast material among patients with an eGFR of <60 mL/min or up to 48 hours before administration of contrast material if the eGFR is <45 mL/min and restarting no sooner than 48 hours after administration of contrast material as long as renal function has remained stable. Diabetic patients who receive intermediate or long-acting insulin should receive half the scheduled dose when NPO in preparation for surgery. Glycemic control should be considered per the current guidelines of the American Diabetes Association.¹⁸

a. Optimization and Risk Assessment

Patients with ESRD often present with significant comorbidities such as hypertension, diabetes mellitus, coronary artery disease, stroke etc. The dialysis schedule of these patients needs to be taken into consideration in order to avoid operation during a state of volume overload and hyperkalemia.

b. Anesthesia Management

i) Anesthesia Techniques

• Local Anesthesia +/- Sedation: This is frequently feasible, depending on the extent of the planned intervention. The choice of local anesthetic drug will depend on expected duration of surgical procedure. Mepivacaine is suitable for procedures of up to 2 hours, Ropivacaine or bupivacaine may be preferred for procedures expected to take longer than 2 hours.

• Regional Anesthetic Technique: Regional anesthetic (i.e., brachial plexus blockade with a single shot injection) is associated with venous dilatation, which can be desirable. Depending on the location of the incision, this can be accomplished by axillary plexus nerve block for more distal incision sites. Infra- or supraclavicular plexus nerve blockade will allow for more proximal procedural sites on the upper arm. If tourniquet will be used, additional blockade of the intercostobrachial nerve may be necessary. All brachial plexus nerve blockades can be performed safely under ultrasound guidance.

• Local or Regional Anesthetic Techniques: Both local and regional anesthetics can be supplemented with light to moderate sedation such as propofol or dexmedetomidine drips for patient comfort.

• General Anesthesia: General anesthetic can also be employed with either endotracheal intubation or supraglottic airway management such as laryngeal mask airways, which are also safe alternatives.

ii) Monitoring and Access

Standard monitoring of SaO2, EKG, non-invasive blood pressure and temperature.

IV access is typically established on the contralateral upper extremity after confirming that the target side is unlikely to be used for future fistula creation. Occasionally, lower-extremity IV access is required.

iii) Intraoperative Concerns

If supraclavicular brachial plexus block was performed, the phrenic nerve may be affected by the block, leading to respiratory distress if the contralateral phrenic nerve has been injured previously.

c. General and Procedure-Specific Concerns

General intraoperative concerns: Skin preparation (CHG wipe timeout for three minutes to dry), If the patient is not anuric, and the procedure is expected to be very long, a Foley catheter can be placed by trained staff. Hair clipping should be performed, and normothermia maintained.

• Percutaneous or surgical Arteriovenous Fistula or Arteriovenous Graft or Revision Surgery for Steal syndrome (e.g., DRIL, PAI, RUDI, banding), venous outflow occlusion, or aneurysm.

  • Local, regional, or general anesthetic as per surgeon preference.

  • Skin preparation with chlorhexidine gluconate/alcohol antiseptic.

  • Perioperative antibiotics are routinely used (cefazolin or vancomycin). o Venous thromboprophylaxis is not necessary.

• Fistulogram +/- angioplasty and stenting +/- coil embolization of competing outflow veins

  • Local anesthetic with sedation is the standard.

  • Skin preparation with chlorhexidine gluconate/alcohol antiseptic.

  • Perioperative antibiotics are used (cefazolin or vancomycin) if a stent or other prosthetic is deployed.

  • Venous thromboprophylaxis is not necessary.

Steps Prior to Discharge

• Pain Control: Acetaminophen or ibuprofen can be used for pain control in patients on dialysis. Pain requiring narcotic pain control is unusual and may require an early clinic evaluation to assess for possible complications.

• Discharge: Patients can be commonly discharged the same day, or on the first postoperative day if a basilic vein transposition or complex venous reconstruction was performed.

Steps After Discharge

• Follow-up: Patients should be called about a week after surgery to assess for pain and possible complications.

• Sutures: Sutures left in situ for hemostasis after percutaneous interventions can be removed by the staff at the dialysis clinic, if appropriately trained clinicians are available.

• Office / Clinic Visit: An office visit should be performed at about two weeks and, if the AVF is not maturing as expected, a duplex should be performed to evaluate for possible causes.

• Medication: The use of long-term medications can be coordinated with the patient’s primary care physician and can include the use of statins or a PCSK9 inhibitor in order to achieve optimal LDL control. In addition, anti-platelet agents, anti-hypertensive agents, and agents for glycemic control should be prescribed, as indicated.

References