Feb. 12, 2004 — Aminocaproic acid (Amicar) is a safe, effective, and inexpensive method of significantly reducing perioperative blood loss in patients undergoing scoliosis repair surgery, according to the Feb. 1 issue of Spine.
"Amicar...is an antifibrinolytic agent with demonstrated efficacy in decreasing blood loss," write Evan Florentino-Pineda, MD, and colleagues from the University Hospitals of Cleveland at Case Western Reserve University in Ohio. "Decreasing blood loss is important in patients with idiopathic scoliosis."
In a preliminary 2001 study, "we demonstrated that Amicar significantly decreased perioperative blood loss in 28 consecutive patients with idiopathic scoliosis undergoing a posterior spinal fusion compared to a historical control group of the previous 31 consecutive patients with the same criteria who did not receive Amicar. We developed a prospective, randomized, double-blind study to confirm our initial results," the investigators explain.
They enrolled 36 patients aged 11 to 18 years diagnosed with scoliosis and scheduled to undergo posterior spinal fusion and segmental spinal instrumentation. Inclusion criteria were identical to those used in the previous study, the exception being the use of homologous bone graft cubes instead of autogenous iliac crest bone graft.
Patients were randomized to receive either aminocaproic acid (n = 19) or saline solution (n = 17). After anesthesia, patients in the aminocaproic acid group received a 100 mg/kg pump infusion of 250 mg/mL solution over 20 minutes, followed by 10 mg/kg/hour dosing throughout the procedure until wound closure.
Although mean intraoperative blood loss was similar between the aminocaproic acid and control groups (893 ± 220 mL vs. 972 ± 372 mL; P = .520), mean postoperative suction drainage was significantly decreased in the aminocaproic acid group (498 ± 179 mL vs. 764 ± 284 mL; P = .014). Total blood loss was also significantly decreased in the aminocaproic acid group compared with the control group (1,391 ± 212 mL vs. 1,716 ± 513 mL; P = .036). This resulted in significantly lower percentage loss of estimated blood volume in the aminocaproic acid group (41% vs. 48%; P = .039).
Hemoglobin levels were significantly higher on postoperative days 2 and 3 in the aminocaproic acid group compared with the control group ( P = .000 for both days). Serum fibrinogen levels were also significantly higher on the first postoperative day compared with placebo (343.7 ± 141 mg/dL vs. 265.6 ± 94 mg/dL; P = .041).
While mean intraoperative autologous blood transfusion was similar between the two groups (.89 ± .7 U vs. 1.1 ± .8 U; P = .532), significantly fewer patients in the aminocaproic acid group required postoperative transfusion (2 vs. 9 patients; P = .002).
No intraoperative or postoperative complications occurred in any patients. There was no clinical evidence of venous thrombosis or thromboemboli in either group.
"Increased fibrinogen levels after surgery...may have enhanced clotting after surgery and thereby decreased bleeding [resulting in a] statistically decreased need for postoperative autologous blood transfusion," the researchers suggest. "Our preliminary results...indicate that a substantial increase in fibrinogen levels occurs during the first 5 postoperative days."
"Intraoperative Amicar is a safe, effective pharmacologic agent that will result in decreased perioperative blood loss (particularly postoperative suction drainage), the need for autologous blood transfusions, and virtually eliminates the need for homologous blood transfusion...thereby improving safety and lowering cost associated with scoliosis surgery," the investigators write. "It is also quite inexpensive compared to Aprotinin ($.56 - $1.12/patient vs. $1,200/patient)."
The study was independently funded; no commercial funded were received for this work.
Reviewed by Gary D. Vogin, MD
Yael Waknine is a freelance writer for Medscape.
Medscape Medical News © 2004
Cite this: Aminocaproic Acid Reduces Perioperative Blood Loss in Scoliosis Repair Surgery - Medscape - Feb 12, 2004.