*3.6.2 Harvesting the vein graft*

This is an important step in the procedure and should not be taken lightly. Exact measurement and harvest of the vein graft is to be done by a competent surgeon very carefully. A slightly longer graft is taken in case damage is done to the ends. Too long a graft will cause tortuousness and kinking, while a shorter graft will tend to stretch and tear or leak.

A length of vein corresponding to the arterial defect is outlined (this is measured before the vein is cut) and using the same meticulous dissection techniques described in Section 3.5, the vein graft is extracted after applying clips (or ligating) both ends. Blood is removed from the vein manually and by irrigation. It is placed in the approximator (double) clamp on one side and the anastomosis is ready to begin.

This is started on the right side (for right-handed surgeons) because the artery gives a firm attachment point, and this is needed because the vein graft is freefloating making it difficult to put a suture through. A piece of coloured paper may be used to assist as background material adding oblique cuts to it, so it can help to hold sutures in place while repair is in progress [5].

The second anastomosis is started after the vein graft is checked to avoid any twisting (this will cause kinks and blockages) and that the double clamp is not straddling the repair site.

### **3.7 Pearls (positive practice)**

There are many pearls of wisdom and these are best summarised in tables according to the procedure that is being performed. **Table 1** describes general rules while **Tables 2** and **3** enumerate good practices for arterial and venous repair respectively.


#### **Table 1.**

*Pre-operative preparation. This table summarises the various measures the surgeon needs to take prior to starting the surgery to ensure its success.*


#### **Table 2.**

*Tips to achieve a good arterial repair. Points to remember when performing an arterial repair.*

#### **Positive practice points**


9. If arterial and venous anastomoses are done simultaneously, release the artery clamps just before the vein.

10. If there is a leak, the vein needs to be re-clamped and repaired after the blood is flushed out.

#### **Table 3.**

*Tips to achieve a good venous repair. Veins need more care in their handling and rest periods in between steps. A keen eye will prevent mishaps such as catching the back wall inadvertently.*

#### **3.8 Pitfalls (negative practice)**

While there are an enormous number of things that can go wrong with even the most experienced surgeon, I have tried to list the most common ones here in order as they appear in the text: Various arterial repair techniques of increasing difficulty (**Tables 4** and **5**), venous anastomosis (**Table 6**) and grafting (**Table 7**) and finally arteriotomy and end-to-side repair (**Table 8**).


#### **Table 4.**

*Arterial repair technique: Triangulation. The column on the left lists the positive actions to be practiced while the column on the right, the negative results thereof.*

**161**

**Table 8.**

*mentioned earlier.*

*Tips and Tricks in Microvascular Anastomoses DOI: http://dx.doi.org/10.5772/intechopen.92903*

1.Have the tips of the clamps facing you. 2.Make the first stitch furthest away from you

6.Divide the vessel ends into equal halves

7. Do not use too long a suture to prevent entanglement

3.Frequent picking up and letting go of the vessel wall.

5. Remember to reverse the vein graft for arterial flow to

*increases chances of success but also reduces time and effort taken.*

1. Perform the arteriotomy in the steps mentioned in the text. 2. Angle the adventitia scissors at 45° to make the cut.

8. Any technique may be used to perform the anastomosis.

10. If using continuous suturing, tighten as you move along.

5. Place a second stitch at 180° to the first.

9. Keep a short leash on the suture length

4. Start with the arterial wall from outside in and take the vein inside out.

6. Place the sutures radially spaced and not longitudinal to the arteriotomy 7. Put in a stay suture on the back wall mid-way between these first two stitches.

*needs to be taken in handling them because they tend to thrombose easily.*

**Pearls Pitfalls**

9.Make sure the knots are squarely tied and secure.

3.Start with the difficult side first and place sutures on either side of the first stitch 4.Avoid entangling your suture when placing the second half of the stitch

8.Keep the stitches evenly placed and pull the thread to evenly tighten it at the end

2.Incorrect handling of the vein with forceps, scissors or bipolar coagulator.

*Pointers in performing arterial repair. Tips to ensure good results in the two other (more challenging)* 

*Pitfalls in venous anastomoses. These are the common mistakes made when anastomosing veins. Extra care* 

*Pearls and pitfalls of vein graft harvest and anastomosis. Performing the right steps in the correct order not only* 

3. Remember to reverse the vein graft and place it straightened out (while still in the clamps).

*Perfecting end-to-side repair. Pointers to bear in mind when performing this in addition to what has been* 

1. Suturing two vessels of mismatched

2. The vein graft shortens after harvest! 3. A skeletonised graft is more susceptible to

4. Not checking for a twist before the second anastomosis may result in unnecessary

5. Using suction while graft is in the operative field is dangerous! Clamps also help avoid it

6. Getting the clamps in the way of the anastomoses may necessitate redoing it!

diameters

anguish!

being sucked in.

damage by the forceps.

**One-way-up technique**

5.Work your way up carefully **Continuous suture technique**

*techniques of arterial repair.*

1.Aggressive dissection and

4.Suturing inverted vessel edges. 5.Picking up the back wall.

1. Ensure right diameter of the vein graft 2. Measure the length of graft **before** harvesting. 3. Take the vein graft with a cuff of fat around it. 4. Lay the vein graft straightened out (untwisted) with both sides in clamps. This avoids twisting with no blood in

graft, while ensuring its visibility.

accommodate for the valves.

**Table 5.**

**Table 6.**

**Table 7.**

#### **One-way-up technique**


#### **Continuous suture technique**


#### **Table 5.**

*The Current Perspectives on Coronary Artery Bypass Grafting*

1. Meticulous handling of soft tissues

5. Rinse blood vessel and dilate it. 6. Approximate clamps

**Positive practice points**

see clearly

vessel

**Table 2.**

vein.

access

ends

**Table 3.**

2. Place (dark) background under vessel ends to

3. Gentle dissection to skeletonise and isolate

4. Methodical and careful removal of adventitia

1. Very gentle dissection and minimal handling of vein.

5. After dilation, bathe in lignocaine then apply the clamps. 6. Perform a meticulous anastomosis with evenly placed sutures. 7. Bathe in lignocaine (2–10%) before releasing the clamps. 8. After releasing clamps, allow the blood to flow for a few minutes.

2. Allow the vein to 'rest' after dissection then place it in the clamp. 3. Flush out all the blood, for any standing blood will cause thrombosis.

*A keen eye will prevent mishaps such as catching the back wall inadvertently.*

**Positive practice points Negative actions to avoid**

**Positive practice points Things to avoid**

*Tips to achieve a good arterial repair. Points to remember when performing an arterial repair.*

4. Dilate the vessel with a single prong, then both prongs of the dilator in different directions.

10. If there is a leak, the vein needs to be re-clamped and repaired after the blood is flushed out.

9. If arterial and venous anastomoses are done simultaneously, release the artery clamps just before the

*Tips to achieve a good venous repair. Veins need more care in their handling and rest periods in between steps.* 

1. Tugging at unyielding tissues. 2. Grabbing the media (full thickness).

4. Using clamps larger than required. 5. Applying the diathermy to the main vessel.

of blood.

3. Performing an action without a clear view or in a pool

1. small and inadequate wound, poor retraction

2. Trying the anastomosis with short vessel ends 3. Persisting in the anastomosis when view is obstructed or when facing trouble.

4. Excessive traction (clamps too far apart) or obscured view of lumen (clamps too close). 5. Asymmetrical placement of sutures with bad

6. Struggling with needle then catching the back

leading to poor visualisation

coaptation of vessel ends

wall.

*Arterial repair technique: Triangulation. The column on the left lists the positive actions to be practiced while* 

**3.8 Pitfalls (negative practice)**

arteriotomy and end-to-side repair (**Table 8**).

1. Have a clear operative field of vision and good

3. Properly trimmed adventitia and clean vessel

5. Divide the vessel into equal thirds and place sutures equidistant from both vessel ends. 6. Clear view and sure of needle placement.

*the column on the right, the negative results thereof.*

2. Mobilise a good length of vessel

4. Comfortable spacing of clamps

While there are an enormous number of things that can go wrong with even the most experienced surgeon, I have tried to list the most common ones here in order as they appear in the text: Various arterial repair techniques of increasing difficulty (**Tables 4** and **5**), venous anastomosis (**Table 6**) and grafting (**Table 7**) and finally

**160**

**Table 4.**

*Pointers in performing arterial repair. Tips to ensure good results in the two other (more challenging) techniques of arterial repair.*


#### **Table 6.**

*Pitfalls in venous anastomoses. These are the common mistakes made when anastomosing veins. Extra care needs to be taken in handling them because they tend to thrombose easily.*


#### **Table 7.**

*Pearls and pitfalls of vein graft harvest and anastomosis. Performing the right steps in the correct order not only increases chances of success but also reduces time and effort taken.*


#### **Table 8.**

*Perfecting end-to-side repair. Pointers to bear in mind when performing this in addition to what has been mentioned earlier.*
