The researches find that the indications for free tissue transfer have expanded since the advent of microsurgery over the last 50 years. However, microsurgery on vessels containing calcified plaque presents several unique technical challenges. As calcified vessels thicken, they become stiff and difficult to handle during surgery. Needle and anastomotic holes may remain patent, leading to leaks as elasticity is lost. Plaque formation lead to intimal delamination by the action of the needle being drive through the vessel wall. Several simple solutions can facilitate success when performing micro-anastomoses between 2 calcified vessels.
The advent of microsurgery
The intimal and medial layers of the arterial wall can become calcified and inelastic with advanced age when loss of elastin and plaque deposition are abetted by hyperlipidemia, diabetes; and renal insufficiency. The fragile intima of vasculopathic vessels easily delaminates. Intimal delamination address by passing a needle from the luminal side to the adventitial side of the artery; effectively tacking the intima to the surrounding media and adventitia in the wall of the artery. Microsurgical suture is generally single arm; making it necessary to pass the suture from adventitia to the lumen on one vessel end and subsequently from the lumen to adventitia on the other vessel being anastomos.
The first half of this process can push the intima away from the media; creating an area of delamination, and potential nidus for thrombosis. Interposition vein grafting for calcified vessel anastomoses can optimize the problem of intimal delamination by suturing from tunica externa to the lumen of the vein graft and the lumen to adventitia of the calcified artery. The same process undertake at the other end of the graft; tacking the arterial intima up and preventing delamination.
The mobility of the vessel
Fragmentation of elastin and calcium deposits in vessel walls can also lead to poor handling quality when mobilizing vessels for anastomosis. Acute and chronic edema can further thicken vessel walls and encase the vascular tree in dense fibrotic tissue. These factors both limit the available length of vessel that is safely expose and decrease the mobility of the vessel that is dissect free.
Stiff handling characteristics make it more difficult to visualize the lumen after one or two sutures have been placed. Limited mobility can make the ergonomics of the anastomosis more challenging. Anastomosing two calcified vessels directly together can place two noncompliant surfaces in contact, creating a poor seal and subsequent leakage. Commonly used anticoagulants, such as aspirin and heparin, may exacerbate hematoma formation in this patient population.