I'd like to thank the Society and its members for the opportunity to present our randomized prospective trial comparing endoscopic to traditionally harvested saphenous vein. Although this is an extreme example of a harvest sight complication, depending upon how a wound complication is defined, it occurs in 1 to 24% of coronary bypass cases. Ours and others' initial positive experience with endoscopic vessel harvesting suggested that this was a good alternative to the traditional techniques we currently use.
The objective of this current prospective study was to compare an endoscopic vein harvest technique to a traditional longitudinal technique. Between October 1996 and February 1997, 112 elective isolated coronary artery bypass operations were prospectively randomized into two groups. Fifty-four patients were randomized to receive endoscopic vessel harvesting, while fifty-eight patients received a traditional longitudinal incision. Operative variables for preoperative demographics were quite equal between groups, particularly with regard to risk factors for lower extremity wound complications. Variables looked at included age, gender, and the presence of diabetes, obesity, hypoalbuminemia and preoperative anemia.
Those patients randomized to the traditional arm of the study had their saphenous vein harvested using a longitudinal fillet incision without skin bridging. Wounds were closed immediately after vein was harvested and no drains were utilized.
Patients randomized to the endoscopic arm of the study had an average of two incisions per patient. Conversion from an endoscopic technique to a traditional harvest occurred in three patients for a 5.6% incidence. Saphenous vein from approximately 2/3 of the leg can be harvested through a single 3 cm transverse incision made either above or below the knee. If proximal saphenous vein is desired, a transverse incision as illustrated here is made above the knee. This is a post-operative result in a very obese female patient four weeks post-operatively after harvesting a vein from groin to mid-calf through a single incision above the knee. If saphenous vein from the lower 2/3 of the leg is desired, an incision is made below the knee. This is the post-operative result four weeks following surgery of saphenous vein removed from just above the knee to the ankle. If saphenous vein is desired from the entire leg, then two incisions are utilized: one above and one below the knee. This is the result four weeks following the removal of saphenous vein from the groin to the ankle.
If I could have the 2-minute video please. A transverse incision rather than a longitudinal incision is made. This aids in identifying the vein particularly in obese legs and avoids unnecessary skin flaps. As much local dissection is done around the vein as possible under direct vision. The endoscopic dissector is then inserted on the anterior surface of the vein and tracked along the amount of vein to be removed. Side branches are identified in this fashion. This shows endoscopicly the scope being inserted anterior to the saphenous vein. As much sharp dissection, using regular instruments, is done as possible and it's very important to stay directly on the anterior surface of the vein to avoid dissection into separate tissue planes.
Side branches are identified and ultimately clipped and divided. An endoscopic clip is applied 3 to 5 mm away from the main vein and the side branch is then transected with either Metzenbaum scissors or endoscopic scissors. The side branch is not clipped and rarely bleeds. A pig-tail dissecting catheter is used after complete dissection to insure that all of the side branch attachments are completely divided. If additional saphenous vein is needed than what has been taken superiorly, the direction of dissection is then turned inferiorly through the same above-knee incision. Once the entire length of saphenous vein is dissected out, the proximal and distal ends are divided endoscopicly with clip appliers and scissors without making additional groin or ankle incisions. The saphenous vein is then prepared on the back table with side branches clipped as usual and the wound is then closed after Protamine is given and the leg is wrapped with an Ace.
Approximately 40 cm of vein was harvested in each group. Harvest time, which is the time an incision is made until the vein is ready for the surgeon to use, was 48 minutes in the endoscopic group and 37 minutes in the traditional group. This 11 minute difference was significant. Harvest rate, which is a more uniform way of calculating and comparing harvest times, was 0.9 cm per minute in the endoscopic group compared to 1.2 cm per minute in the traditional group. Wound healing was defined using Dr. Utley's definition that a complication had occurred if the wound had inflammation, dehiscence, cellulitis, lymphangitis, necrosis, drainage, or abscess necessitating antibiotics or debridement prior to complete healing without eschar. Patient's were followed on a daily basis while in the hospital by a research nurse and also evaluated at a six-week follow up visit by a research nurse who ultimately determined whether a wound complication had occurred. Follow up was 100% in both groups.
The incidence of wound complications were dramatically different between the two groups. In the 51 patients randomized to endoscopic harvesting, wound complications occurred in 4% of patients compared to 19% in the traditional group. Complications in the endoscopic group included one hematoma and one patient with cellulitis. Complications in the traditional group included three patients with cellulitis, three patients with cellulitis and associated wound breakdown, and five patients with wound breakdown alone.
Using chi square analysis, traditional longitudinal incision and diabetes were independently identified as risk factors for lower extremity wound complications. Multiple logistic regression analysis, however, identified only the traditional longitudinal incision as a risk factor for the development of a saphenous vein harvest site complication.
We feel that patients recover faster and ambulate sooner with endoscopic harvesting. The average hospital length of stay in EVH group was 5.6 days compared to 6.5 days in the traditional group. Ours is a group practice and our discharges are very pathway driven, but at this time, a direct correlation between decreased length of stay and harvest technique can't or should not be made.
The cost of this emergent technology is also very important. DRG indexed operating room costs were increased in the EVH group primarily because of the use of disposable harvesting equipment. DRG indexed overall hospital costs, however, were not different, primarily because of the decreased length of stay observed in the endoscopic group.
Outpatient resource utilization was not included in our cost analysis in this study. The reduction in outpatient resource utilization may be a very important benefit of the endoscopic technique, particularly considering the decreased incidence of wound complications.
The issue of vein trauma is also an important consideration. There were no known acute graft closures and the incidence of perioperative myocardial infarctions were similar between groups.
The number of 7-0 Prolene venous repair sutures required for each segment of harvested vein were recorded during the operation. The endoscopic group required 1.6 repair sutures compared to only 0.4 in the traditional group. While this data would suggest no gross endothelial damage, subtle endothelial damage with its long-term implications is an important consideration, particularly considering the number of increased venous repair sutures seen in the endoscopic group. There is no patency rates currently published for endoscopicly harvested vein used for coronary artery bypass grafting.
Endoscopicly harvested saphenous vein used in lower extremity bypasses however resulted in a 97% patency rate with a mean follow up of 10 months in a small cohort of patients from Emory University. Only long-term follow up will address whether harvest method influences potency.
In conclusion, we feel that endoscopic saphenous vein harvesting yields fewer wound complications than the traditional harvest methods and its increase use in coronary artery bypass grafting is warranted. Thank you very much for the opportunity to present our group's data.