Discovering Coronary Artery Bypass Surgery – Step 2

Step 2: Harvesting Arterial and Venous Grafts in Coronary Artery Bypass Surgery

Introduction

The harvesting of arterial and venous grafts is a key step in performing coronary artery bypass surgery (CABG). The quality of the grafts and the harvesting technique directly influence the success of the operation by ensuring proper blood flow and graft durability. The choice of grafts depends on the patient and the surgeon’s preferences. The two most used grafts are the internal thoracic artery (also called internal mammary artery) and the saphenous vein.

I. PRESENTATION OF GRAFTS

1. Versatility and Adaptability of Grafts

The harvesting technique must be tailored to the specific characteristics of the patient and the anatomical conditions encountered during surgery. The type of graft and the chosen method play a crucial role in the success of CABG.
The quality of the grafts determines not only the blood flow but also the durability of the vessels, which will serve as new coronary arteries after surgery. This has a direct impact on the patient’s vital prognosis.

2. Types of Grafts

Several types of grafts can be used for coronary bypass surgery, grouped into two categories:

Arterial grafts: The most used is the internal thoracic artery (ITA), also known as the internal mammary artery (IMA).
Venous grafts: The most used is the saphenous vein, typically harvested from the lower limbs.

II. HARVESTING THE INTERNAL THORACIC ARTERY

The internal thoracic artery can be harvested using two techniques: skeletonization or pedicled harvesting. Each approach offers specific advantages based on clinical needs and the surgeon’s preferences.

1. Skeletonization Technique

This method involves completely isolating the artery from its surrounding structures, including the separation of thoracic and mammary veins and surrounding tissues.

Advantages: This technique allows for a longer and better-vascularized artery, increasing the graft’s success rate. It also preserves collateral blood supply, minimizing the risk of ischemia. ¹

2. Pedicled Technique

This method involves harvesting the artery along with a segment of surrounding tissue, including the vessels and nerves that supply the artery.

Advantages: It provides better protection for the artery as the surrounding tissue preserves its blood supply, potentially reducing postoperative complications.¹

3. Hemostasis of Collateral Branches

Regardless of the chosen technique, ensuring hemostasis of the internal thoracic artery’s collateral branches is essential to limit hemorrhagic risks.
Titanium clips such as Clip 9 Vitalitec® or Clip SLS Vitalitec®—available in micro (W9060), small (J9180/R9180), or small-medium (L9180) sizes depending on the vessel size and surgeon preference—are ideal for this step. These clips provide effective hemostasis while preserving vascular tissue integrity.

4. Graft Preparation

After isolating the internal thoracic artery, the preparation continues by separating it from the aponeurotic tissue. This step ensures an additional graft length but makes exposure more delicate.

To prevent bleeding, it is crucial to use appropriately sized, high-quality clips (small-medium L9180 or medium B9180) capable of remaining stable under systemic arterial pressure. Titanium clips, easily and accurately applied with the Vitalitec® Titanium Clip Applicator, ensure optimal clip placement while preserving vessel properties.

These measures help avoid injuries to collateral branches and main vessels, which could otherwise lead to hematomas or tears that compromise graft use.

5. Verifying Graft Functionality

Once harvesting is complete, verifying graft functionality, especially blood flow, is imperative. The use of a single Peters Surgical clip for hemostasis during this step highlights the effectiveness of this device.

6. Medical Devices: Novaclip® Bulldogs

Bulldogs are used to clamp the mammary artery without causing vessel damage. They ensure secure occlusion while preserving the intimal layer, which is critical for the graft’s long-term success. The most suitable Bulldog from the Peters Surgical range is the Novaclip® Yellow Angled N10113.

III. HARVESTING THE SAPHENOUS VEIN

Saphenous vein harvesting is typically performed on a lower limb, with careful attention to sectioning and ensuring hemostasis of the collateral branches.

1. Harvesting Techniques, Hemostasis, and Collateral Branch Separation

Two techniques are available for saphenous vein harvesting:

Open technique: This method provides direct visualization of the vein and its branches.
Endoscopic technique: Minimally invasive, this approach offers benefits in terms of postoperative recovery and reduced scarring.

The principle is like that described for ITA grafts: collateral branches must be separated and ligated. Medium-sized titanium clips (B9180) are generally suitable for this purpose. Their efficiency and stability under pressure are crucial, as the graft will be subjected to significant arterial pressure once integrated into the arterial circulation.

2. Graft Verification and Securing

Graft integrity is verified by injecting saline solution. A single-use Bulldog Novaclip® Yellow Angled N10113 is used to occlude the vein and test its integrity. Additional clips may be applied along the vein to secure the graft.

IV. WOUND CLOSURE

Sutures for closing subcutaneous layer wounds must be absorbable and braided, such as Optime® 2/0 (polyglycolic acid-coated braid), to minimize inflammatory reactions.

The skin layer can be closed with absorbable or non-absorbable monofilaments, depending on the surgeon’s preference:

Absorbable monofilament: Advantime® 3/0 (poly glycolide-co-caprolactone monofilament) for intradermal sutures.
Non-absorbable monofilament: Filapeau® 3/0 (polyamide monofilament) for Blair-Donati stitches.

Conclusion

Harvesting arterial and venous grafts is a delicate step in coronary artery bypass surgery. Ensuring effective hemostasis, particularly through the use of Peters Surgical titanium clips, guarantees graft quality while minimizing operative risks. These devices, combining stability and efficiency, are designed to preserve vessel integrity and maximize surgical success.

VITALITEC SLS-CLIP® TITANIUM HEMOSTATIC CLIP

INDICATIONS:

Mechanical occlusion of blood vessels. For use with VITALITEC clip appliers only.

Class III Medical Device- CE 0459 – Manufacturer: Peters Surgical.