G. Dean Harter, M.D.
Frank L. Cuce, D.O., J. Richard Bowen, M.D.
Alfred I. duPont Institute
1600 Rockland Road
Wilmington, DE 19803
INTRODUCTION: Posterior spinal fusion is a major surgical procedure often associated with considerable blood loss. Performing this procedure without the option of blood transfusion is a serious undertaking which few orthopaedic surgeons are willing to attempt. Literature review demonstrates few reports of posterior spinal fusion in Jehovah's witnesses. Only two reports have discussed multiple cases. The only reported literature involving posterior spinal fusion with instrumentation does not discuss follow-up data.
MATERIALS AND METHODS: A retrospective review of posterior spinal fusion with instrumentation was performed. Procedures performed at the Alfred I. duPont Institute between 1980 and 1994 were included. All patients were Jehovah's witnesses, and all procedures were performed without the option for blood replacement. Twelve patients were included in the study. Three attending surgeons were involved. Preoperatively, a thorough medical evaluation was performed. Any medications that could potentially interfere with the clotting mechanism were discontinued. Iron supplementation was given for one week prior to the procedure, and was continued postoperatively until the hemoglobin level returned to normal. Blood loss control was extremely important in the preoperative plan. It was determined that an estimated blood loss equal to 10% of the patients blood volume could be safely tolerated. The procedure would be terminated at this point, and continued at a second stage. Use of allograft bone was also implemented to decrease blood loss. Operative technique included meticulous exposure with strict attention to blood loss. Multiple self retaining refractors were used to decrease skin bleeding via a tamponade effect. Exposure was limited to only four spinal segments at a time. Careful facet excision was performed bilaterally, however, there was no further posterior decortication. Allograft bone was utilized in each case. Various instrumentation systems were used. Postoperative closed suction drainage systems were not used. Casting was performed postoperatively in all cases. All surgery was performed under hypotensive anesthesia.
RESULTS: All twelve procedures were performed at a single setting. No intraoperative complications occurred. Average estimated blood loss was 307 cc, and the average operative time was two hours and four minutes. The lowest postoperative hemoglobin was 7.3. No cardiovascular symptoms were noted. Average follow-up was two years and nine months (ten months to five years and four months).The average preoperative curve magnitude was 62.9 degrees with an average correction of 23.4 degrees after the procedure. There was no significant difference between curve correction and the type of instrumentation utilized except the modified unit rod. The minimal correction achieved in this single case was due to a severe rigid neuromuscular curve. Average loss of curve correction with follow-up was 4.5 degrees. Again, there was no correlation with the type of instrumentation used. Complications included two cases of hook dislodgement (18.2%), and two cases of pseudoarthrosis (18.2%). Both cases of pseudoarthrosis required reoperation. There were no life threatening complications.
DISCUSSION: The results of the current study is compared to Dr. Bowen's study reported in 1985. All cases in his previous study were performed without instrumentation. Casting was utilized to achieve correction to achieve correction of the deformity. Surgical technique was otherwise identical to that used in the current study. Average curve correction was 30 degrees, and the pseudoarthrosis rate was 22.2 %.
CONCLUSION: Posterior spinal fusion can be safely performed without blood replacement if the advised techniques are carefully followed. Only experienced spinal surgeons should attempt this procedure. The instrumentation systems utilized in our study did not appear to affect the operative time, estimated blood loss, curve correction, loss of correction, or the pseudoarthrosis rate.
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