Decreasing homologous blood transfusion in spinal surgery by use of the cell saver and predeposited blood.

Blood loss and blood replacement are necessities in spinal surgery. They also have increasing risks. Three blood replacement options and combinations were investigated in patients undergoing major spinal deformity surgery. In Section 1, intraoperative replacement from harvested cell saver blood was investigated in 35 patients. This group averaged 40% (20-60%) return of the red cell mass lost intraoperatively. In Section 2, intraoperative replacement via predeposited autologous blood was investigated in 41 patients. The predeposited blood replaced 64% of the intraoperative red cell mass lost. In Section 3, ten single-stage and ten two-stage spinal surgery cases using both cell saver and autologous predeposited blood were investigated. With this program, 90% of the single-stage patients did not require additional homologous blood, while 80% of the two-stage patients did. In Section 4, 65 patients undergoing six general types of spinal surgery were examined to determine the number of predeposited autologous units needed to avoid homologous blood during hospitalization. Guidelines for determining optimal donation were developed assuming the use of intraoperative cell saver use.

Incidence of mitral valve prolapse in adolescent scoliosis and thoracic hypokyphosis.

Seventy-four patients with adolescent scoliosis underwent cardiac examination and M-mode echocardiography to detect the presence of mitral valve prolapse (MVP). Twenty-one (28%) had echocardiographic evidence of MVP, whereas 18 had auscultatory findings of a nonejection click or late systolic murmur. A subset of 41 patients had a family history of scoliosis and 37% had MVP. The incidence of MVP increased to 41% when a first degree relative, such as a sibling, parent, or offspring, had scoliosis. Thirty-six patients with scoliosis had additional thoracic hypokyphosis (straight back) and 13 (36%) had MVP. The incidence of MVP was 48% when the scoliosis and hypokyphosis were hereditary and increased to 53% when a familial history of skeletal abnormality was present. This study indicates a high incidence of MVP in patients with scoliosis and hypokyphosis, especially when the cardiac and skeletal systems may be affected by a generalized soft-tissue defect.

In vivo effects of axial loading on double-curve scoliotic spines.

The in vivo three-dimensional orientation of the vertebral columns in five adolescent idiopathic scoliotic subjects with double curves were examined in standing, supine, and supine positions with Cotrel traction postures using a biplanar radiographic technique. This analysis was compared with that obtained from a previous study on five healthy adolescent subjects to assess the postural changes and mechanical factors relating to the development of double-curve scoliotic deformity. Statistical analysis of vertebral orientation, rotation, disc distraction, and wedging between the normal and scoliotic subjects indicated that central intervertebral disc height and anteroposterior wedging were most consistently altered in double-curve scoliotic deformity. Since these two parameters relate directly to the geometry of the disc, the etiology of double-curve scoliosis may be related to a primary defect affecting the geometry of the intervertebral disc that results in a vertebral column which then undergoes rotational deformity.

In vivo effects of axial loading on healthy, adolescent spines.

Five healthy adolescents were studied using a three-dimensional radiographic technique to analyze the in vivo effects of standing, supine and supine Cotrel traction positioning on the orientation of spinal segments. In general the configuration of these spines was found to be relatively unaffected by changes in subject position and column loading. The major effects of supine positioning appeared to be lessening of standing lumbar lordosis while supine traction tended to diminish this effect. Measurement of rotation relative to a common reference body, L4, was influenced by the degree of AP and ML wedging throughout the column. The standing curve was found to be slightly rotated by a small but constant amount at each level and tended to derotate as a whole with supine and supine traction positioning. Measurement of successive intervertebral rotation showed effects independent of wedging with each vertebral body randomly rotated and unaffected by subject orientation. With the exception of central vertebral disk heights, all parameters measured possessed relatively wide limits of variability which appeared to be the result of true intersubject scatter as opposed to measurement error.