Atlas of General Surgical Techniques (Courtney M. Townsend Jr., B. Mark Evers)

C H A P T E R 90 • Hemodialysis Access Procedures 1001

Femoral artery

Femoral vein

Saphenous vein

PTFE graft

FIGURE 90–21

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2. DISSECTION

Arterial inflow and venous outflow are isolated. Proximal and distal control of both vessels is obtained.

The graft is tunneled, with care taken to keep the graft untwisted and to maintain a proper depth (approximately 4 mm). A counter-incision may be required, depending on the anatomic location (Figure 90-22).

Once the tunnel is completed, the patient is heparinized. A small hood is cut in each end of the graft, which is oriented according to the direction of flow. The vessels are clamped, and end-to-side anastomoses are performed to the target artery and vein with 6-0 Prolene suture. If the graft has a pre-existing (i.e., manufactured) venous hood, the venous anastomosis should be performed first to size the length of the graft appropriately.

The clamps are removed, with the distal arterial clamp removed last. The graft is palpated for a thrill. Revision may be necessary if a thrill is not readily palpable. If the graft twisted in the tunnel, the anastomosis may need to be taken down and the vein retunneled. If the graft is pulsatile without a thrill, a distal obstruction may be present. A venogram can be performed to assess for stenotic lesions.

3. CLOSURE

The wound is closed in two layers with interrupted 3-0 Vicryl subcutaneous sutures and a running 4-0 Monocryl subcuticular layer.

C H A P T E R 90 • Hemodialysis Access Procedures 1003

Tunneler

PTFE graft

Basilic vein

FIGURE 90–22

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STEP 3: OPERATIVE STEPS—GRAFT REVISION: THROMBECTOMY

1.INCISION

Most commonly, a small incision is made over the fistula or graft a few centimeters downstream from the arterial anastomosis.

2.OPERATIVE APPROACH

Proximal and distal control of the fistula or graft is obtained. The patient is heparinized.

A transverse incision is made in the conduit. A balloon thrombectomy catheter is passed up the venous limb first, and the clot is removed. The process is repeated for the arterial limb. There should be the return of strong, pulsatile flow on removal of the arterial clot

(Figure 90-23).

A fistulogram or shuntogram is performed to assess for anatomic causes of the thrombosis. The central veins should be assessed as part of this venogram to evaluate for central stenoses. Peripheral or central stenoses may require balloon angioplasty or stenting.

Short jump grafts or patch angioplasties are required for persistent anastomotic strictures

(Figure 90-24).

3.CLOSURE

The wound is closed in two layers with interrupted 3-0 Vicryl subcutaneous sutures and a running 4-0 Monocryl subcuticular layer.

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STEP 4: POSTOPERATIVE CARE

Patients should be examined again in the recovery room, and regularly until discharge, for a thrill and a bruit in the access.

Fistulae require a minimum of 6 weeks to mature before cannulation. Most grafts require a minimum of 2 weeks before cannulation.

Long-term catheters should be removed promptly once the fistula or graft has matured and has been used successfully for hemodialysis.

Arm swelling that persists beyond the second postoperative week and does not respond to arm elevation should be investigated further with imaging.

Fistulae often have venous side branches that prevent adequate maturation. If these are found, selective ligation of the branches can allow for maturation of the fistula. Imaging should be obtained of fistulae that do not mature by the sixth postoperative week.

Mature fistulae (greater than 6 weeks after placement) are more likely to be usable if they meet the Rule of 6s criteria: flow greater than 600 mL/min, diameter larger than 6 mm, depth less than 6 mm, and discernable margins.

Patients should be instructed in isometric hand exercises and in daily examination of the access for a thrill or signs of infection.

STEP 5: PEARLS AND PITFALLS

Nondistendable veins are sclerotic and usually will not mature. Noncompressible veins are thrombosed. A history of intravenous drug use, chemotherapy, or multiple intravenous catheters at the site may indicate the presence of such veins.

When a fistula or graft thromboses or has consistently high venous pressures, a fistulogram or shuntogram should be performed, which includes a central venogram. Because many of these patients have had multiple catheters, they are at risk for subclavian vein stenoses. If such a stenosis is found, it may be amenable to angioplasty and stenting. If the subclavian vein is actually occluded, the other arm should be assessed for access sites.

Most of the arterial targets course near major nerves. Care should be taken to avoid traction injury or other damage to these nerves, especially in redo operations, where the anatomy may not be as well demarcated as usual.

Steal syndrome, defined as ischemia of the hand, is more common with artificial conduit than autologous fistula, probably because the slower maturation of the fistula allows acclimation and collateralization to develop. Steal symptoms are also more common when the anastomosis is above the elbow or the patient is diabetic. These symptoms may occur

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SELECTED REFERENCES

1. National Kidney Foundation: KDOQI clinical practice guidelines and clinical practice recommendations for 2006 updates: Hemodialysis adequacy, peritoneal dialysis adequacy, and vascular access. Am J Kidney Dis 2006:48: S1-S322.

2. Haisch CE, Parker FM, Brown PM Jr: Access and ports. In Townsend CM Jr (ed): Sabiston Textbook of Surgery: The Biological Basis of Modern Surgical Practice, 17th ed. Philadelphia, Elsevier Saunders, 2004,

pp 2081-2094.

3.Bohannon WT, Silva MB: Venous transpositions in the creation of arteriovenous access. In Rutherford RB (ed): Vascular Surgery, 6th ed. Philadelphia, Elsevier Saunders, 2005, pp 1677-1684.

4.Lumsden AB, Bush RL, Lin PH, Peden EK: Management of thrombosed dialysis access. In Rutherford RB (ed): Vascular Surgery, 6th ed. Philadelphia: Elsevier Saunders, 2005, pp 1684-1692.

5. Knox RC, Berman SS, Hughes JD, et al: Distal revascularization-interval ligation: A durable and effective treatment for ischemic steal syndrome after hemodialysis access. J Vasc Surg 2002;36:250-255.