Blood clots are one of the risks associated with spine corrective surgery. To reduce this risk, patients are generally administered potent drugs, which while effective, come with their own set of side effects. Now, new research shows that most children undergoing spine operations may never develop blood clots and hence need not be administered these risky and expensive anticoagulant drugs.

According to this new study by the Johns Hopkins Children's Center, only high-risk groups need to be administered anti-clotting medications. Blood clots in children is a fairly unresearched area, and there is no standard set of guidelines about who should receive medication and when. This research aims to educate doctors of the sub-groups of patients who would better benefit from these anti-clotting medications.

"Our findings should help clinicians weigh the pros and cons of preemptive treatment and focus on those who stand to benefit the most," said senior investigator Dr. Paul Sponseller, chief of pediatric orthopedics at Johns Hopkins. "Most children undergoing spine surgeries should be perfectly safe without medication. Treatment should be reserved for the handful of patients who have a real risk of developing dangerous clots. In these patients, the benefits of treatment far outweigh the risks."

The findings published in the July 15 online edition of the journal Spine, suggests that preemptive clotting should be considered only for a small subset of high-risk patients in whom normal blood clotting may not take place due to some underlying medical condition.

A study of past cases shows that, on average, there were just 21 episodes of blood clots for 10,000 surgeries, and none of the clots resulted in death of the patient. While this shows that blood clots are rare, there are certain groups where the risks are high. These groups include children with congenital scoliosis, a spinal deformity present during birth. These children are four times more likely to develop deep-vein clots than other children undergoing spinal surgeries. Also children who underwent surgery to repair spinal fractures were 12 times more likely to develop a clot while children whose spinal curvature was part of a syndrome were seven times more likely to develop a blood clot than others.

The study also found that the risk of clotting increased with age with the risk rising 1.2 times per year of age, so older children were more vulnerable. If congenital scoliosis is accompanied with other forms of deformity or if secondary scoliosis has occurred as a result of syndromes such as spina bifida or cerebral palsy, then the risk of clot formation is higher. Children undergoing surgery due to injury to the back are also at a risk due to prolonged periods of inactivity needed after a major accident.

"Prolonged inactivity impedes blood circulation and can foster clot formation, which can drive up clotting risk in trauma patients following spinal surgery, as some of them tend to have multiple fractures or other injuries that require immobilization for weeks, even moths, on end," said lead investigator Amit Jain, orthopedic surgery resident at Johns Hopkins. 

The study was based on the results of surgical procedures conducted on nearly 22,000 children nationwide who had spinal fusion surgery between 2001 and 2010. Scoliosis and fractures of the spine are the two major reasons that people undergo spine fusion surgeries. Scoliosis alone results in 38,000 patients undergoing surgeries each year.

The risk of blood clots, which occurs due to several reasons, is very high during such surgeries. Blood clots that form in the veins of the legs are referred to as deep vein thrombosis (DVT). If a portion of the blood clot breaks free inside the veins, it can travel to the lungs and get stuck inside the numerous tiny vessels. This cuts of blood supply to that part of the lung and increases risk of lung collapse, a condition called pulmonary embolism. This can be fatal and requires emergency treatment.

To prevent this, patients undergoing spine surgery are administered medication to prevent DVT. But its use is associated with side effects such as rashes, dizziness, blisters on skin, irregular sleep patterns, and also serious issues like bleeding or bruising, hives, or difficulty breathing. This study suggests that since blood clots are rare in children, 'round the clock monitoring after surgeries may be all that is required. 

Source: Sponseller P, Jain A, Karas, D, Skolasky R. Spine. 2014.