An interventional study of Photobiomodulation Therapy and Placebo Laser in Coronary Artery Disease, Coronary Artery Bypass Graft (CABG) and Surgical Wound Healing, sponsored by Federal University of São Paulo. Not yet recruiting at 1 site in Brazil. Open to participants aged 18 Years to 75 Years. Per ClinicalTrials.gov, last updated 2026-07-13.
Sponsored by Federal University of São Paulo · Not applicable, Interventional, and Treatment
This randomized, double-blind clinical trial aims to evaluate the impact of photobiomodulation therapy on postoperative outcomes in patients undergoing coronary artery bypass grafting (CABG). The study will compare two techniques for saphenous vein graft harvesting: the conventional technique and the no-touch technique. Participants will be randomly allocated into four groups: conventional harvesting with placebo, conventional harvesting with photobiomodulation, no-touch harvesting with placebo, and no-touch harvesting with photobiomodulation. The primary objective is to evaluate the effects of photobiomodulation on wound healing and postoperative complications related to the saphenous vein harvesting site. Secondary outcomes include clinical outcomes and functional capacity after surgery. The results may contribute to improving postoperative recovery and optimizing surgical strategies in patients undergoing myocardial revascularization.
Cardiovascular diseases remain one of the leading causes of morbidity and mortality worldwide. Coronary artery bypass grafting (CABG) is a widely performed surgical procedure for the treatment of advanced coronary artery disease. The saphenous vein is frequently used as a graft in CABG; however, complications related to vein harvesting, including wound infection, delayed healing, and postoperative pain, remain relevant clinical concerns.
The no-touch technique for saphenous vein harvesting has been proposed as a strategy to preserve the structural integrity of the vein and potentially improve graft patency and reduce local tissue trauma. In addition, photobiomodulation therapy (low-level laser therapy) has demonstrated beneficial effects on tissue repair, inflammation modulation, and wound healing.
This study, named PHOTON Study, is a randomized, double-blind, controlled clinical trial designed to investigate the effects of photobiomodulation therapy in patients undergoing CABG. Participants will be randomized into four groups according to the harvesting technique and the use of photobiomodulation therapy. This study protocol was developed in accordance with the SPIRIT (Standard Protocol Items: Recommendations for Interventional Trials) guidelines.
Photobiomodulation will be applied using a cluster laser device (E-light, DMC Equipamentos Ltda., Brazil) with a wavelength of 660 nm and output power of 100 mW. The laser will be applied locally along the surgical incision of the saphenous vein harvesting site using a point technique with standardized spacing between application points. The intervention will be performed intraoperatively and during the early postoperative period.
The primary outcomes include wound healing and postoperative complications related to the saphenous vein harvesting site. Secondary outcomes include clinical outcomes and functional capacity following surgery.
This trial may contribute to improving postoperative care and recovery in patients undergoing coronary artery bypass grafting.
Exclusion Criteria:
Patients undergoing conventional saphenous vein harvesting with simulated laser application (placebo).
Device: Placebo Laser · Procedure: Conventional Saphenous Vein Harvesting
Patients undergoing conventional saphenous vein harvesting with active photobiomodulation therapy applied to the surgical incision.
Device: Photobiomodulation Therapy · Procedure: Conventional Saphenous Vein Harvesting
Patients undergoing saphenous vein harvesting using the no-touch technique with simulated laser application.
Device: Placebo Laser · Procedure: No-Touch Saphenous Vein Harvesting
Patients undergoing saphenous vein harvesting using the no-touch technique with active photobiomodulation therapy applied to the surgical incision.
Device: Photobiomodulation Therapy · Procedure: No-Touch Saphenous Vein Harvesting
Photobiomodulation will be applied using a cluster laser device (E-light, DMC Equipamentos Ltda., Brazil) with wavelength of 660 nm and output power of 100 mW. The therapy will be applied along the surgical incision of the saphenous vein harvesting site using a point technique with standardized spacing between application points. The intervention will be performed intraoperatively and during the early postoperative period.
Simulated photobiomodulation therapy applied using the same laser device without emission of therapeutic laser energy. This placebo procedure is used to maintain blinding of participants and outcome assessors.
Conventional Saphenous Vein Harvesting refers to the traditional open surgical technique used to obtain the great saphenous vein for grafting procedures, most commonly in coronary artery bypass grafting (CABG). The procedure involves a continuous longitudinal incision along the course of the vein in the lower limb, allowing direct visualization and careful dissection of the vessel from surrounding tissues. Side branches are ligated or clipped, and the harvested vein is subsequently prepared for use as a vascular graft. The technique is performed under sterile surgical conditions by qualified surgeons.
No-Touch Saphenous Vein Harvesting refers to a surgical technique for harvesting the great saphenous vein in which the vein is removed together with a pedicle of surrounding perivascular tissue, avoiding direct manual manipulation and excessive distension of the vessel. The procedure is performed through an open incision under sterile conditions, preserving the vein's adventitia, vasa vasorum, and surrounding connective tissue in order to minimize endothelial injury and maintain vascular integrity. Side branches are carefully ligated or clipped, and the harvested graft is prepared according to institutional surgical protocols for subsequent use in vascular or coronary artery bypass procedures.
Incidence of surgical wound complications at the saphenous vein harvesting site
Occurance of wound infection at the surgical incision of the saphenous vein harvesting site.
Time frame: From postoperative hospitalization to 30 days and 3 months after surgery.
Functional capacity assessed by the Six-Minute Walk Test
Functional capacity will be evaluated using Six-Minute Walk Test to assess exercise tolerance and postoperative recovery in patients undergoing coronary artery bypass grafting.
Time frame: From preoperatory assessment to postoperative day 5 or at hospital discharge, 30 days and 3 months follow-up.
Frequency and severity of adverse responses to photobiomodulation therapy
Assessment of the frequency and severity of adverse reactions associated with photobiomodulation therapy during the hospital stay.
Time frame: From the first photobiomodulation therapy session until hospital discharge (Postoperative day 5 or earlier, if discharged).
All-cause mortality
Incidence of death from any cause following coronary artery bypass grafting.
Time frame: Hospital discharge, 30 days after discharge and 3 months after discharge
Hospital readmission
Incidence of hospital readmission following coronary artery bypass grafting.
Time frame: 30 days and 3 months after discharge
Myocardial infarction
Incidence of myocardial infarction following coronary artery bypass grafting.
Time frame: Perioperative, 30 days after discharge and 3 months after discharge.
Length of stay in the intensive care unit (ICU)
Duration of stay in the intensive care unit measured in days after surgery.
Time frame: From date of surgery until ICU discharge (assessed up to 30 days).
Length of hospital stay
Total duration of hospital stay measured in days.
Time frame: From hospital admission until hospital discharge (assessed up to 60 days)
Plasma interleukin-1 (IL-1) levels
Assessment of plasma IL-1 concentrations measured by enzyme-linked immunosorbent assay (ELISA).
Time frame: Preoperative period, immediately after surgery before photobiomodulation application, 20 minutes after ICU admission, and on postoperative days 2 to 5 or until hospital discharge.
Plasma interleukin-6 (IL-6) levels
Assessment of plasma IL-6 concentrations measured by enzyme-linked immunosorbent assay (ELISA).
Time frame: Preoperative period, immediately after surgery before photobiomodulation application, 20 minutes after ICU admission, and on postoperative days 2 to 5 or until hospital discharge.
Plasma interleukin-8 (IL-8) levels
Assessment of plasma IL-8 concentrations measured by enzyme-linked immunosorbent assay (ELISA).
Time frame: Preoperative period, immediately after surgery before photobiomodulation application, 20 minutes after ICU admission, and on postoperative days 2 to 5 or until hospital discharge.
Plasma interleukin-10 (IL-10) levels
Assessment of plasma IL-10 concentrations measured by enzyme-linked immunosorbent assay (ELISA).
Time frame: Preoperative period, immediately after surgery before photobiomodulation application, 20 minutes after ICU admission, and on postoperative days 2 to 5 or until hospital discharge.
Plasma tumor necrosis factor-alpha (TNF-α) levels
Assessment of plasma TNF-α concentrations measured by enzyme-linked immunosorbent assay (ELISA).
Time frame: Preoperative period, immediately after surgery before photobiomodulation application, 20 minutes after ICU admission, and on postoperative days 2 to 5 or until hospital discharge.
Thiobarbituric acid reactive substances (TBARS) levels
Assessment of lipid peroxidation by measuring TBARS levels in EDTA plasma samples.
Time frame: Preoperative period, immediately after surgery before photobiomodulation application, 20 minutes after ICU admission, and on postoperative days 2 to 5 or until hospital discharge.
Protein carbonylation (CPr) levels
Assessment of oxidative stress through protein carbonylation analysis.
Time frame: Preoperative period, immediately after surgery before photobiomodulation application, 20 minutes after ICU admission, and on postoperative days 2 to 5 or until hospital discharge.
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Federal University of São Paulo