Major abdominal surgery increases plasma levels of vascular endothelial growth factor: open more so than minimally invasive methods.
BACKGROUND
Vascular endothelial growth factor (VEGF) is a potent inducer of angiogenesis that is necessary for wound healing and also promotes tumor growth. It is anticipated that plasma levels would increase after major surgery and that such elevations may facilitate tumor growth. This study's purpose was to determine plasma VEGF levels before and early after major open and minimally invasive abdominal surgery.


METHODS
Colorectal resection for cancer (n = 139) or benign pathology (n = 48) and gastric bypass for morbid obesity (n = 40) were assessed. Similar numbers of open and laparoscopic patients were studied for each indication. Plasma samples were obtained preoperatively and on postoperative days (POD) 1 and 3. VEGF levels were determined via ELISA. The following statistical methods were used: Fisher exact test, unmatched Student t test, Wilcoxon's matched pairs test, and the Mann Whitney U Test with P < 0.05 considered significant.


RESULTS
The mean preoperative VEGF level of the cancer patients was significantly higher than baseline level of benign colon patients. Regardless of indication or surgical method, on POD3, significantly elevated mean VEGF levels were noted for each subgroup. In addition, on POD1, open surgery patients for all 3 indications had significantly elevated VEGF levels; no POD1 differences were noted for the closed surgery patients. At each postoperative time point for each procedure and indication, the open group's VEGF levels were significantly higher than that of the matching laparoscopic group. VEGF elevations correlated with incision length for each indication.


CONCLUSIONS
As a group colon cancer patients prior to surgery have significantly higher mean VEGF levels than patients without tumors. Also, both open and closed colorectal resection and gastric bypass are associated with significantly elevated plasma VEGF levels early after surgery. This elevation is significantly greater and occurs earlier in open surgery patients. The duration and clinical importance of this finding is uncertain but merits further study.
Belizon
Avraham
A
Department of Surgery, College of Physicians and Surgeons of Columbia University, New York, NY 10032, USA.
Balik
Emre
E
Feingold
Daniel L
DL
Bessler
Marc
M
Arnell
Tracey D
TD
Forde
Kenneth A
KA
Horst
Patrick K
PK
Jain
Suvinit
S
Cekic
Vesna
V
Kirman
Irena
I
Whelan
Richard L
RL
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D015415:Biomarkers / Q000097:blood; D003082:Colectomy; D003108:Colonic Diseases / Q000097:blood / Q000601:surgery*; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D005500:Follow-Up Studies; D015390:Gastric Bypass; D006801:Humans; D008297:Male; D008875:Middle Aged; D019060:Minimally Invasive Surgical Procedures; D009767:Obesity, Morbid / Q000097:blood / Q000601:surgery*; D011184:Postoperative Period; D011379:Prognosis; D012189:Retrospective Studies; D042461:Vascular Endothelial Growth Factor A / Q000097:blood*
D015415:Biomarkers; D042461:Vascular Endothelial Growth Factor A