The Basics of Vascular Access Construction and Its Timing

1. The purpose of VA construction

2. The method of VA construction (surgical procedure) and pre-surgical examinations

3. Introduction to the surgeon and assistant

4. Method of anesthesia

5. Time of operation

6. What to be careful after surgery

7. Actual method of the use of the VA (actual cannulation)

8. Patency rates for various VAs

9. Importance of periodic examinations of VA function and form

10. Expected VA-related complications

11. Methods of restoration for complications above

12. Others

It is not advisable to discuss all subjects in one setting giving them the all the same level of importance. It is best to choose the necessary subjects based upon the patient’s disposition and condition, dividing the explanation into several discussions with repeated question and answer sessions

Table 3.2

Complications associated with VA construction

1. Inadequate blood flow

2. Stenosis (narrowing of the arterial or venous lumen)

3. Thrombosis (disruption or occlusion of VA blood flow)

4. Infection of cannulation site

5. Aneurysm at the cannulation site

6. Venous hypertension (sore thumb or sore hand syndrome)

7. Steal syndrome (ischemic injury)

8. Excessive blood flow, increased stress on cardiac function (high-output failure)

9. Recirculation

10. Limited cannulation area, complications in the cannulation area

11. Others

After a period of use, all VAs will show wear. The patient needs to understand this, and when it becomes necessary, restoration of the VA should be explained to the patient

Fig. 3.1

Patency rates for initial shunt in the distal forearm. The patency rate for the older age group and diabetes group is clearly poorer than that of the younger age group

3.1.2 When to Construct the VA

According to the 2011 Edition of VA Guideline (VA-GL) of the JSDT (Japanese Society for Dialysis Therapy 2011), in Chap. 2, GL-5, it is recommended as expert opinion that “VA construction should be considered when eGFR is less than 15 mL/min/1.73 m² (CKD stages 4 and 5) as well as taking into account clinical conditions.” In addition, “In patients with diabetic nephropathy, who have a tendency to show overhydration, VA construction should be considered at a higher eGFR.” The 2011 Edition of the VA-GL also states that “Anticipating the start of hemodialysis from the results of various laboratory tests and clinical symptoms, ideally the AVF should be constructed at least 2–4 weeks before the initial puncture. In the case of an AVG , the time from construction to initial puncture should be 3–4 weeks.” Also from the JSDT, it is noted in the Clinical Guideline for Hemodialysis Initiation for Maintenance Hemodialysis (Japanese Society for Dialysis Therapy 2013) in Statement 5 that “It is recommended that arteriovenous fistula (AVF) and arteriovenous graft (AVG) be created at least 1 month prior to the initiation from the viewpoint of expected lifespan after hemodialysis initiation.” Care should be taken to assure that the initiation of dialysis is not too early or too late taking into account renal function and symptoms, with the best indicator being that the constructed AVF or AVG are matured (dilated) at the time of cannulation .

The nephrologist should allow the patient to be examined by a VA surgeon beforehand so that the surgeon has ample time prior to surgery to make a thorough examination of the arteries and veins for use in the proposed VA.

3.1.3 Basics of VA Construction

3.1.3.1 Selecting the Type of VA

If the situation requires emergency HD, then HD must be initiated with an intravascular indwelled catheter. Except for this situation, as a rule AVF or the next best choice, AVG , should be the type of VA chosen in cases where there is ample time of 1 month or more before the proposed initiation of HD. Whichever the choice, it is essential to examine in detail the arteries and subcutaneous veins of the arm of the patient. A frequently used AVF in the distal forearm is typically constructed with a radial artery and cephalic vein side (A) to end (V) anastomosis. Because there are more variations in the veins than arteries in the arm, it becomes necessary to predict which vein will dilate with the anastomosis of the previously mentioned AVF (Fig. 3.2). Although there are fewer variations in the arteries compared to the veins, the pulse of the radial artery in the distal forearm may not be palpable due to arteriosclerosis in elderly patients. In such a case, there is little arterial blood flow, and creation of an AVF in the distal forearm will be difficult. Not limited to just the elderly, it is vital to choose the type of VA taking into consideration the condition of the arteries and veins in addition to any accompanying symptoms as well as the remaining life expectancy as shown in Fig. 3.3.

Fig. 3.2

Arteries and veins of the upper limb. During the construction, management, and restoration of AVF/AVGs, it is necessary to remember the names of the arteries and veins in the upper limb and to make a detailed record. Variations are more frequent in veins than arteries

Fig. 3.3

Average remaining life expectancy of dialysis patients based on age. The remaining life expectancy of dialysis patients is roughly half compared to persons the same age in the general population

3.1.3.2 VA Construction (Surgery)

Whatever the type of VA, the factors having the most effect on short-term and long-term results (patency) are (1) the patient’s vascular condition (age, gender, underlying disease, cardiovascular complications, blood pressure , degree of obesity, degree of anemia, etc.) and (2) the surgeon’s skill (selection of location, choice of vessels, diameter and type of anastomosis, surgical experience, etc.). With regard to the patient’s vascular condition, these conditions cannot be changed; therefore, the best choice of VA and location will need to be made in accordance with the patient’s vasculature. With regard to the skill of the surgeon, thorough education and practical training are necessary for the physician before they can be considered proficient. A German vascular surgeon (Hehrlein 1995) aptly stated, “The best way to reduce early thrombosis is to hire a skilled surgeon.”

Anesthesia of VA Construction

The purpose of anesthesia is to relieve the patient of uneasiness and pain during the operation. First, it should be recognized that chronic kidney failure patients are at high risk with regard to anesthesia. A work-up of their overall condition, especially a thorough examination of their cardiac function and blood pressure , should be performed. Local anesthesia is sufficient for the anastomosis of the AVF using native vasculature; however, in some cases, due to the aggressiveness of the surgery or disposition of the patient, sedation may be added. If the area of the surgery is in the middle of the limb or near to the trunk, a nerve block or general anesthesia will be chosen. Monitoring of the patient’s respiration, blood pressure, and body temperature is required during and after the surgery.

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