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Enucleation
SOP » Surgery protocol » Enucleation
Last modified on Tue 15 Jul 2014

Exposing the lateral and inferior walls of the heart, while maintaining stable hemodynamics, is the goal of
every multi-vessel off-pump coronary. The preparation for enucleating the heart requires constant communication with anesthesia. This process is divided into three major steps: the deep stitch, the sling and the enucleation.

The deep stitch :
The surgeon needs three tools : a heavy calibre suction catheter, a folded dry gauze and a
100 cm n°1 Prolene (non-absorbable, monofilament), loaded and ready. The conditioning of the patient is reviewed by the surgeon and, if needed, optimized before continuing the procedure. Anesthesia is notified that the deep stitch is about to be placed and, when ready, gives permission to the surgeon to lift the heart
The heart is lifted with the left hand from the apex cranially, avoiding lateral displacement. The right hand places the gauze deep towards the transverse sinus, then the left hand is placed even deeper beyond the AV groove, for maximal exposure of the posterior pericardium. The suction catheter clears the field of blood. The stitch is placed in the posterior pericardium as far cranially as possible and towards the right inferior pulmonary vein.

Fig. 5 : Anchor stitch placement

The surgeon must be careful not to catch the pulmonary vein or the oesophagus with the stitch.

Fig. 6 : The anchor in place

The sling :
The surgeon needs three tools : a 28-cm thick silastic tube, an extra-long 30 cm tourniquet guide and a moist 4x8 sponge. The conditioning of the patient is reviewed by the surgeon again and, if needed, optimized before continuation of the surgery. Anesthesia is notified that the sling is ready to be placed and, when ready, again gives permission to proceed.
While the surgeon lifts the heart with the left hand, the right hand holding a heavy forceps, guides the gauze down to the suture point avoiding injury to the myocardium. The assistant drives down the tourniquet with a heavy clamp so that it is secure and tight.

Fig. 7a : The gauze within the tournique, before being guided down to the anchor point

Fig. 7b : The gauze within the tournique down to the anchor point, but too wide open for efficient leverage

Enucleation :
The surgeon gradually enucleates the heart by grasping both ends of the sling, rigorously
avoiding any ectopic beat or cardiac dysfunction. The sling is pulled against the left side of the retractor, thereby avoiding any compression of the left ventricle.

Fig. 8 : Sling arms against left side of sternal retractor, the V of the slings is closed

Gradual adjustments of the sling are required to keep the mass directly within the V-shape created by the gauze.

Fig. 9 : The mass of the left ventricle in the middle of the sling and the sling arms rather close to one

The process is completed under strict supervision from the anaesthesiologist. If this manoeuvre is performed correctly, the left atrium will mobilize in synchrony with the left ventricle without distortion of the mitral valve plateau (ATS 2002; 73:1424).

 

Fig. 10 : mitral valve plateau (ATS 2002; 73:1424)

Once the apex is pointing upwards, the leg block is checked to ensure that the patient’s legs do not fall
to the side. The table is rotated 30° to the right, further exposing the lateral wall of the heart and unloading it from the sling.

The apical suction device is clamped to the retractor in the upper right position. The optimal placement of the suction is on the antero-lateral side of the apex, avoiding the inferior wall and the LAD. Stay away from the inferior surface so as to maintain suction despite the contour changes during reformatting. Once the apical suction device has been placed, the effect on the patient’s hemodynamics must be checked.
(NOTE : if the heart’s only functioning area is the anterior/apical region, the apical suction likely will not be tolerated.). A deterioration of heart function when the device is applied indicates that the surgeon should cease its use and proceed without the apical suction.

The use of the device accomplishes three tasks :

  • Apical stabilization, accomplished once the arm of the suction device is in the surgeon’s hand.
  • Reformatting of the ventricle. The sling has allowed exposure but causes the ventricle to become spherical. Gentle traction on the device will cause it to regain a conical shape. A convex inferior wall that becomes flat again is confirmation of a reformatted ventricle.
  • Exposure of the coronary vessels is attained by slowly retracting the apex toward the patient’s right shoulder. Avoid retracting to the right lower portion of the wound as this can compress the inferior vena cava (IVC). The target vessels on the lateral wall can now be identified.

Widening the v-shape of the sling may be necessary to maximize visualization.