INTRODUCTION

The greater saphenous vein (GSV) is still the commonest harvested graft for revascularization in coronary arteries diseases (1, 2). The usual way for the harvesting is open vein harvesting (OVH). Many reports mentioned that the disadvantages of open technique are post-operative pain, delayed healing, and prolonged hospital stay (3, 4). For those reasons, many trials were developed for minimally invasive techniques to diminish the postoperative trauma and fasten the patients’ healing without troubling the postoperative results (4, 5). By the time, more evidences developed to advise that the endoscopic vein harvesting (EVH) technique can decrease the incidence of post-operative infections, pain, mobility restriction, and the hospital stay days (6). At the start, no significant variances in graft patency of OVH were noticed in comparison with EVH in the first six months of postoperative follow up (7). But recently, some studies mentioned that EVH could be associated with worse graft patency (6). From the histological view, there were big controversies between EVH and OVH techniques which some studies said that is no differences in both techniques and others commented on big variations in the endothelial cellular surface with OVH technique. Higher incidence of venous graft failure and mortality with myocardial infarction was concomitant with OVH technique. Also a higher rate of revascularization during the first year after the surgery was noticed by same technique (3).

We planned to make this study on elective CABG candidates who made their own decisions to undergo the techniques. The Target of this study was to examine the perioperative and histological findings of OVH and EVH techniques in elective on-pump patients.

MATERIALS AND METHODS

Over a period of 18 months, starting from January 2015 up to July 2016, we choose 40 patients with multivessel ischemic heart disease undergoing CABG operation more than one graft. The 40 patients are located in 2 groups according to the technique of saphenous vein harvesting (endoscopic or open). Each group consisted of 20 patients. The two groups were being examined to find the outcomes. The design of the study was a prospective. All patients were informed about the study, informed consent was taken from all patients and the study was approved by the ethics committee.

 Inclusion Criteria of the study are the patients with multivessel ischemic heart disease undergoing isolated CABG operation with more than one graft. CABG operation with right internal mammary artery or radial artery grafts or single vessel ischemic heart disease or redo CABG or patients with other surgical interventions in the lower limb or patients with peripheral vascular diseases or emergent procedure, all those patient are excluded from the study.

In both groups, the grafts were taken by skilled surgeons using weather standard open technique, with ligating and clipping the side branches, or endoscopic technique. The EVH technique was done using Virtuo-SaphTM (Terumo Cardiovascular Systems Corporation., USA) system with carbon dioxide insufflation.

Samples were taken for histological examinations from each harvested vein during the surgery. The vein sample was at least 1 cm. Then the samples were collected, preserved in paraffin sections and stained by Hematoxylin and eosin stains. Histological reports were recorded and collected.

Significant perioperative data were registered. Follow-up, patients were extended until 6 months postoperatively. Follow up here include: Post-operative leg Pain, Wound healing and infection (in 1st postoperative month), Non infective wound healing disturbances NIWHD (Hematoma formation, seroma formation). Patient satisfaction, cosmoses, early mobilization and hospital length of stay are considered in this study.

All analyses were executed by SPSS version 16.0. Comparison between groups was made with Student’s t-test when appropriate. Values of P<0.05 were consid­ered statistically significant.

Table 1

Preoperative data of the patients

Table 2

Intra-operative data of the patients

Table 3

Histopathological examination results of the grafts

Table 4

Postoperative data of the patients NIWHD=Non infective wound healing disturbances

Figure 1

Microscopic picture of vein harvested by open technique (OVH)

Figure 2

Microscopic picture of vein harvested by endoscopic technique (EVH)

RESULTS

There was no major variance between groups in the preoperative clinical picture (Table 1). Most of the patients were male. From the 20 patients of EVH group, 58 grafts were being needed to be harvested. While from the 20 patients of OVH group, 56 grafts were be prepared with mean of 2.8 grafts per patient. Significant percentages of diabetic patients were present in both groups.  The time needed to harvest the vein grafts by EVH technique is significant longer than OVH technique. The postoperative data are summarized in table (4). Incidence of postoperative leg pain in OVH patients is highly significant lesser than in EVH patients. The pain at the harvesting site in leg wound postoperatively was assessed by visual analogue scale (VAS). The pain is usually related to the length of skin incisions which are incredibly significant longer in OVH group than in EVH (table 4).  The post-operative harvest site wound infections occurred in form of opened or gapped wounds post operatively during hospital stay until 1st month postoperatively after hospital discharge. All infected wounds had a positive culture and were treated with specific antibiotics without wound incision and drainage.  Significant reduction in wound infection with EVH technique is noticeable (Table 4).  Non infective wound healing disturbances (NIWHD) occur in the form of seroma formation or hematoma formation. The incidence of NIWHD in EVH is significant less than in OVH group (Table 4).  Patients’ satisfaction and cosmsis are highly significant improved with EVH than in OVH group. Significant earlier mobility and lesser hospital stay are noticeable for patients undergoing EVH.

As mentioned before in the methodology, specimens from harvested veins from all the patients in the study were taken and sent for histopathological examination to evaluate the quality of the harvested veins. The results of the specimens taken from both groups (OVH and EVH groups) were 100% complete normal grafts samples. The media was intact without intimal tears or disruption of the vein wall layers or tiny defect with bleeding or leukostasis in capillaries of the vasa vasorum in all samples (Table 3, figure1, .figure 2).

DISCUSSION

Open saphenous vein harvesting was the unique technique in coronary artery bypass surgery for many years. But, now, the endoscopic harvesting technique becomes more widespread in many cardiac centers all over the world. The benefits of this technique were mentioned in Marker et al literature (8). It includes reduced leg wound problems, leg pain, analgesia and skin incision length. The drawbacks of the technique were registered like possibility of carbon dioxide (CO2) embolism during CO2 insufflation (9), longer learning curve (10) and the shortage in the follow up of long-term patency of endoscopically harvested veins (11).

In this study, we found the time needed for vein harvesting by EVH technique is significant longer than OVH technique and it means that technician experience and longer learning curve is needed to improve the results and decrease the time needed as described in Desai et al (12) and Kiani et al studies (13).  

The most noticeable benefit of the EVH is the improvement of the post-operative care and lesser leg morbidity (14-16). In the EVH group, we recorded a statistically significant lower postoperative pain (after one week), lesser wound infection and NIWHD (one month postoperatively), better satisfaction and cosmosis, earlier mobilization and lower hospital stay. Most probably, the cause is significant smaller skin incision and lesser tissue manipulation in EVH patients. Because of that, the recommendation of 2014 ESC/EACTS Guidelines about EVH is “Endoscopic vein harvesting should be considered to reduce the incidence of leg wound complications” (17).  

According to occurrence of myocardial infarction (MI) within 6 months post CABG and mortality, there is no significant difference found between the EVH and OVH groups. It is an indicator for early and mid-term graft patency. Our study result is similar to the results of Sastry et al study (18).  At the level of the histopathological examinations of vein graft specimens, we found that all the specimens of both groups were the same result showing normal histopathological picture as regard intact media with intact intima and there was no vein wall disruption related to harvesting trauma. It means that there is no difference between OVH and EVH techniques on graft quality as long as the surgeon has enough experience to do it safely and in true manner. It is important to expect the early and mid-term vein graft failure due to bad technique. Some studies mentioned that endoscopic vein harvest could be related to with a definite vein endothelial injury which could induce thrombosis and decrease in graft patency (19, 20)

One of the limitations of this study, beside the low study number, is the little definite data about the long-term patency of endoscopically harvested veins. Although we depend on long term clinical and radiological follow up to expect the progress of the patient, definite long term angiographic catheterization based follow up is in need to do exact evaluation of the harvested veins patency  in both groups.

CONCLUSIONS

Endoscopic vein harvest becomes now a dominant technique over the open vein harvest in many cardiac centers. This research confirmed the privilege of this technique on leg-related morbidity. The harvesting time is significant longer in the EVH technique which means that the procedure needs more practice and longer learning curve.  There is no histological difference between the EVH group and OVH group proving that the EVH may be safe and not associated with significant endothelial damage of the graft. These outcomes said that EVH technique is not significantly concerned with a harmful effect on graft endothelium which leads to worse graft patency, as mentioned in several studies. Long term follow-up and investigations are required to examine the long-term patency of endoscopic harvested vein grafts.