Morbidity of Conventional and No-touch Saphenectomy in Coronary Artery Bypass Grafting.

Current clinical trials have shown that the no-touch saphenectomy technique has had a positive impact on the short- and long-term patency of coronary bypass, compared to the conventional extraction technique. It is important to highlight that the conventional technique is the most used in our country (Uruguay, South America), while the "no touch" has fallen into disuse.

Given this disparity in the application of the techniques, it is considered essential to compare both methods in terms of morbidity. For this purpose, a prospective randomized clinical trial will be carried out.

The primary objective is to demonstrate the non-inferiority of the "no touch" technique over the conventional technique in terms of wound morbidity in patients undergoing coronary revascularization, within a non-inferiority margin. Defining morbidity as the combined result of local infection, hematoma, blisters, secretions, necrosis, wound dehiscence, paresthesias, pain and functional impotence.

The investigators will seek to achieve as a specific objective the incidence of each of the study factors: local infection, hematoma, blisters, secretions, necrosis, wound dehiscence, paresthesias, pain, functional impotence and then compare them between both groups at different times.

The anatomopathological study of some of the saphenous vein preparations, one "no touch" and the other conventional, will also be carried out using optical microscopy and ultrastructural comparisons using transmission electron microscopy.

Additionally, patients will be offered computed tomography angiography every year to evaluate graft patency.

There are not many relevant randomized clinical trials that compare the morbidity of this technique with the conventional one. In this context, we consider it crucial to evaluate whether there are significant differences in terms of wound morbidity in the mid-postoperative period (1 week), late (1 month) and long-term postoperative period (6 months).

We will define each variable previously: it will be considered to have a local infection when the wound shows signs of flow and it has been necessary to start antibiotic treatment, hematoma when there is a tumor or abnormal hardening caused by the accumulation of blood, flictenes when a skin blister appears on the wound that contains watery substances and not pus, secretions when the wound secretes a liquid (serous, bloody, purulent), necrosis when there is a necrotic plaque in the wound larger than 10 x 10 mm, dehiscence of the wound when the suture loses continuity, paresthesia when there is a tingling sensation due to an irritative sensitivity disorder, pain when it is located at the level of the wound and functional impotence when it prevents or limits ambulation.

Through multivariate analysis, the relationship with independent factors will be analyzed.

Null hypothesis: "no touch" saphenectomy is inferior to the conventional technique.

Alternative hypothesis: "no touch" saphenectomy is not inferior to the conventional technique.

Existing studies have focused their attention on evaluating the patency of the ducts; however, there is a lack of solid information on the morbidity associated with this technique in the lower limb of patients. Currently, the most widely used technique remains the conventional one, which involves a continuous incision in the skin of the leg or thigh. In this technique, a dissection of the subcutaneous tissue surrounding the vein is performed, the collaterals are ligated, and the free venous duct is sectioned. The length of the conduit varies depending on the amount of bypass to be performed. During the extraction of the saphenous vein using the "no touch" technique, it is sectioned with the perivascular adipose tissue and the saphenous nerve of the leg, therefore, it is of great interest for us to evaluate the incidence of the postoperative complications, previously mentioned, and compare these results with those obtained through the conventional technique.

Inclusion criteria

• Patients undergoing coordination coronary revascularization surgery, in which it is necessary to use the internal saphenous vein as a conduit.

Exclusion criteria

• Emergency surgeries.
• Poor metabolic control (HbA1c > 6.5%).
• Chronic venous insufficiency or chronic obstructive arteriopathy of the lower limbs.
• Type II obesity (BMI>35).