In spite of continued advances in medical science, we have been unable to rid ourselves of complications related to surgery. While the amount of literature pertaining to spine surgery has grown exponentially, the number of well controlled prospective studies of large numbers of patients with adequate follow-up is amazingly small. Studies specifically addressing morbidity and mortality number less than ten. As health care resources become less and less plentiful we face increasing pressure from outside sources to improve our success rates and therefore cost-effectiveness.
Complications can be divided into two types, those directly related to
surgery and those which are indirectly related, i.e. medical complications.
The indirect complications are by definition those medical problems which
arise after or as a direct result of a surgical procedure. The rate of complications varies between different procedures. The number and types of problems encountered in "simple" discectomy are different from those found in procedures which incorporate fusion. Morbidity and mortality rates are also dependent upon the patients' preexisting medical, psychological and social histories. In spite of the large number of variables it is important to generate data which is as specific as possible regarding complications related to a specific procedure. The following data have been gleaned from the literature.
I. Direct Complications. All surgical complications = 7% (3.3
- 19%).
A. Complication of prosthesis or graft = 10.8 % (1 - 37%)
B. Discitis = 1.8% (1 - 2%)
C. Iatrogenic aural tear/laceration = 1.5% (0.02 - 17%)
D. Hemorrhage or hematoma = 0.66% (0.09 - 4.43%)
E. Wound infection = 0.48% (0 - 4%)
F. Cauda equina syndrome = 0.14% (0 - 0.6%)
G. Wound dehiscence = 0.14% (0 - 2.5%)
H. Injury to nerve root or cord = 0.06% (0 - 0.62%)
I. Gut perforation = 0.04%
II. Indirect complications. All medical complications = 3% (0.21
- 3.6%)
A. Respiratory = 0.39% (0.11 - 0.88%)
B. Gastrointestinal = 0.33 % (0 - 0.93 %)
C. GU/renal Insufficiency = 0.30% (0 - 0.87%)
D. Cardiac = 0.22% (0 - 0.5%)
E. CNS = 0.14% (0 - 0.33%)
F. Sepsis = 0.06% (o - 0.07%)
III. Mortality = 0.07% (0 - 0.6%)
These figures are rough averages of those reported in the literature. They are probably UNDERestimates of the rates when evaluated as a whole. These studies are primarily of patients undergoing discectomy for the first time. They tend to be young and healthy preoperatively and have few complications. In the largest series, from Deyo et al, the rate of morbidity and mortality increase greatly with advancing age and with fusion procedures. They found a total complication rate of 6.4% for patients aged 18 - 40 and 18% for those over 7S. The total complication rate for procedures without fusion
was 7.6% while that for any procedure with arthrodesis was 17~o. Their patient
population was comprised of all patients discharged from non federal hospitals
with a diagnosis of any spinal surgical procedure in the State of Washington
over a 2 year period.
One must be extremely cautious when drawing conclusions from data such
as this. The reliability is dependent upon accurate and complete coding
of discharges. Incomplete input may skew the results. In order to provide
a full assessment of the complication rates, it is necessary to include as much information as possible so that patients with different clinical syndromes/diagnoses are not grouped together in the same group of results/complications. As anyone who cares for spine patients knows, all are not equal!
Bibliography
Deyo, R.A., Cherkin, D.C., et al. MORBIDITY AND MORTALITY IN ASSOCIATION
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Stolke, D., Sollman, W.P., et al. INTRA- AND POSTOPERATIVE COMPLICATIONS
IN LUMBAR DISC SURGERY. Spine, 14;1, 56-59. 1989
Spangfort, E.V., THE LUMBAR DISC HERNIATION. A COMPUTER AIDED ANALYSIS
OF 2504 OPERATIONS. Acta Orthop Scand Supp, 142. 1972 -
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SG&O, 173; 1, 22-24. 1991
Anda, S., Aakhus, S., et al. ANTERIOR PERFORATIONS IN LUMBAR DISCECTOMIES.
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Turner, J.A., Ersek, M., et al. PATIENT OUTCOMES AFTER LUMBAR SPINAL
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