Ileal Bladder Stoma Seals in Polyethylene Jackets
L. MERCER MCKINLEY, M.A., M.B., B.CH. THOMAS A. MARTIN, C.P.O
The conservative treatment of paralytic thoracolumbar scoliosis in myelodysplasia using casts or other corrective external jackets is often complicated by the placement of the ileal bladder stoma on the anterior abdominal wall. Leakage of urine around the seal produces an eczematous reaction in the skin, unless the external corrective jacket can be removed so that the skin can be washed and prepared and a new bag and seal can be applied. These problems can be overcome when the patient achieves skeletal maturity and the spine can be stabilized in a compensated position, using the Dwyer apparatus or Harrington instrumentation and posterior spinal fusion. No further external supports are required when the fusion is solid.
However, in the intermediary years, the forces of growth must be directed to prevent deterioration of the curve; and external corrective measures are necessary. We have produced a sealing system using a convex heal stoma seal surrounded by a polyethylene ring which is pressed into the skin by the plastazote-lined polyethylene jacket. This jacket is molded to produce external correction of the scoliosis and thus prevent progression of the curve.
The patient is placed on a Cotrel casting table, and the spine is distracted by an axial force equal to the patient's own body weight. The bag is removed, and the stoma is covered with a small drinking cup, cut down to barely cover the stoma. An elongation-derotation-flexion (EDF) cast is then applied, using the derotation straps to produce correction of the scoliosis. An indelible pencil should be used to outline important landmarks, such as the anterior-superior iliac spines, symphysis pubis, and jugular notch so that when the mold is pulled off the plaster model of the patient's torso, the indelible pencil marks will be found marking these landmarks. When the thin cast has nearly dried, it is cut off with a scalpel and taken to the orthotic shop, where the positive mold is immediately poured. The plaster replica is then shaped; localization of the stoma is checked clinically, and this location is compared with the delineated landmark on the plaster replica.
When the plaster positive mold has been prepared, the orthosis is constructed by wrapping a sheet of plastazote-lined polyethylene around this mold. The circle for the stoma is cut out; and to allow more room for manipulation of the bags around the stomal seal, we use a ring of polyethylene, as shown in Figure 1 . This ring sits around the periphery of the Hypalon (a registered trademark of E. I. DuPont de Némours and Company, Inc.) convex face plate and is sandwiched between this plate and the polyethylene jacket. When the jacket is firmly applied, the convex surface of the face plate is firmly indented into the skin around the stoma. This pressure causes the stoma to protrude slightly into the seal ( Figure 2 ). It affords a good, tight fit without the need for accessory belts. The polyethylene ring allows more room for access to the face plate, and spinal correction is obtained by using a mold obtained from the Cotrel EDF principle. 1 If any accidents occur and leakage has taken place, the orthosis can be removed, the patient and the orthosis can be washed, and the orthosis can then be reapplied to the patient. Otherwise, the jacket stays on 24 hours a day as would a corrective cast.
We feel this technique offers an excellent way to control the paralytic scoliosis of myelomeningoceles who have ileal bladder seals and who presently are difficult patients to manage conservatively because of occasional leakage at the stoma or because of anesthetic skin areas.
1. Cotrel, Yves, Médecine et Hygiene, No. 922, June 17, 1970.