AUTHOR(S): Fisher, Wink S., III, M.D.; Braun, Dale, M.D.
Neurosurgery 31; 155-156, 1992 ABSTRACT: THE AUTHORS DESCRIBE a technique for closing the posterior fossa dura. KEY WORDS: Dural closure; Dural substitute; Surgical techniques Not infrequently during posterior fossa procedures, we feel compelled to attach a dural substitute to the posterior fossa dural opening to allow for postoperative swelling and to decompress the posterior fossa. Because of patient positioning, closure of this opening can be somewhat frustrating, particularly when the dural substitute does not conform to the opening that occurs. When opened in the fashion as described by Kempe (2), the posterior fossa dural opening forms the shape of an inverted chevron (IC) (3) (Fig. 1). Dural substitute usually comes in either square or rectangular shapes, and, therefore, we have tried to find a way to fit a dural substitute to the IC opening. The authors describe a method for closing the posterior fossa dura using a rectangular graft and fashioning it so the closure can conform to the surgical opening. TECHNIQUE The dural substitute is first soaked in antibiotic solution before placing it into the posterior fossa. This allows the dural substitute to become much more pliable and flexible. As shown in Figure 2, the first step taken is to cut the edges of one end of the rectangle to form a tapered point. This is the starting point for attachment of the dural substitute to the original dural opening near the apex of the IC (shown in Figure 2 just above the C2 spinous process, points "A" and "a"). To allow the rectangular graft to separate into an IC, a cut is made down the middle of the graft. The two arms of the rectangular graft are then spread out laterally to form the IC shape (Fig. 2C). Sutures are placed along each of the sides of the dural opening from "D" to "A" and from "C" to "A". It is helpful to place tacking sutures near the top of the opening (as outlined in the diagram at points "C" and "c" and "D" and "d"). At that point "B" and "b" may be approximated, and the arms of the rectangle, which have been now splayed apart, can be trimmed. This allows for a perfect fit to the posterior fossa opening.
Received, November 12, 1991. Accepted, December 30, 1991. Reprint requests: W.S. Fisher III, M.D., University of Alabama at Birmingham, 511 Medical Education Building, 1813 6th Ave., S., UAB Station, Birmingham, AL 35294. REFERENCES: (1-3) 1. 2. 3.
Fisher WS III, Six EG: Cervical myelopathy from dural substitute. Neurosurgery 13:715717, 1983. Kempe LG: Operative Neurosurgery, New York, Springer-Verlag, vol. 2, 1970. Webster's Seventh Collegiate Dictionary, Springfield, MA, G&C Merriam Co., 1965.
COMMENT The technique described for shaping a graft for posterior fossa dural closure is very helpful. Frequently, dissociation of the dura during prolonged posterior fossa surgery leads to retraction that makes it difficult to obtain a primary closure. In the past, this was not thought to be an important
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Division of Neurosurgery, University of Alabama (WSF), Birmingham, Alabama, and Department of Neurosurgery, Naval Hospital Bethesda (DB), Bethesda, Maryland
DISCUSSION Dural reconstruction and interest in dural substitutes dates from 1897 when Beach suggested the use of gold foil to prevent meningocerebral adhesions. Since then, various substances have been used, including periosteum, fascia lata, metals, rubber, Celluloid plates, parchment, peritoneum, fat, muscle, omentum, cellophane, mica, dermal grafts, Cargile membrane, hernia sack, catgut, polyvinyl sponge, Gelfoam, fibrin, umbilical cord, Silastic, Teflon, freeze-dried dura mater, and methyl methacrylate (1). We prefer the use of cardiac pericardium at one of our institutions (University of Alabama) because of its flexibility and ability to stretch. However, if a tissue bank is not accessible, then commercially available products, including Tutoplast and Lyodura, must be used when autologous tissue is not available. Typically, these substances are stiff when first removed from their packages. By soaking these substances, they become more pliable, allowing for some stretching of the graft. Soaking alone may be insufficient to allow for correct manipulation and fashioning of the graft to fit the posterior fossa opening. Before using the IC closure, we frequently misjudged the fit of the graft to the opening. By splaying the graft arms apart, a better fit of the posterior fossa opening was possible. We have used this closure on most of our posterior fossa craniectomies where dural substitute is needed. The biggest error we have seen is that the vertical cut allowing for the two arms of the rectangle to be splayed apart (forming the IC) can be made too long, not allowing approximation of "b" to "B". Usually, this has to be such a long overcut that accidental extension of this incision is infrequent. To correct such an overcut, closure of the linear incision is made with a few additional stitches back to a point where "b" and "B" may be approximated.
Redistribution of this article permitted only in accordance with the publisher’s copyright provisions.
Neurosurgery 1992-98 July 1992, Volume 31, Number 1 155 Closure of Posterior Fossa Dural Defects Using a Dural Substitute: Technical Note Technical Note
Howard H. Kaufman Morgantown, West Virginia REFERENCES: (1) Kaufman HH, Carmel PC: The etiology of aseptic meningitis and hydrocephalus after posterior surgery. Acta Neurochir 44:179-196, 1978.
Redistribution of this article permitted only in accordance with the publisher’s copyright provisions.
1.
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problem. The dura was frequently left open, and the closure begun at the level of the muscle. However, in those days, aseptic meningitis and even hydrocephalus were often seen after posterior fossa surgery, and a considerable amount of work was performed trying to determine the cause of this problem (1). Today, the trend is to obtain dural closure and this problem is less frequently seen. However, primary closure is often difficult, and the technique described for fashioning a graft of the proper shape to facilitate this closure is certainly helpful.
Redistribution of this article permitted only in accordance with the publisher’s copyright provisions.
Figure 2. Steps of the IC closure. A, the graft is cut so that one end is tapered. B, a vertical cut is made in the graft. C, the arms of the graft can then be splayed apart. D, the graft is sewn into the dural opening. Each upper-case letter is sewn to its corresponding lower-case letter. To simplify the technique, tack-up sutures are placed in the following order: "A" to "a," "D" to "d," and "C" to "c."
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Figure 1. Military insignia composed of two parts: a, the "chevron" and b,. the "rocker arm." If the chevron is turned upside down, it forms the inverted chevron shape. This is the shape of the posterior fossa opening as described by Kempe (2).
Neurosurgery 31; 155-156, 1992 ABSTRACT: THE AUTHORS DESCRIBE a technique for closing the posterior fossa dura. KEY WORDS: Dural closure; Dural substitute; Surgical techniques Not infrequently during posterior fossa procedures, we feel compelled to attach a dural substitute to the posterior fossa dural opening to allow for postoperative swelling and to decompress the posterior fossa. Because of patient positioning, closure of this opening can be somewhat frustrating, particularly when the dural substitute does not conform to the opening that occurs. When opened in the fashion as described by Kempe (2), the posterior fossa dural opening forms the shape of an inverted chevron (IC) (3) (Fig. 1). Dural substitute usually comes in either square or rectangular shapes, and, therefore, we have tried to find a way to fit a dural substitute to the IC opening. The authors describe a method for closing the posterior fossa dura using a rectangular graft and fashioning it so the closure can conform to the surgical opening. TECHNIQUE The dural substitute is first soaked in antibiotic solution before placing it into the posterior fossa. This allows the dural substitute to become much more pliable and flexible. As shown in Figure 2, the first step taken is to cut the edges of one end of the rectangle to form a tapered point. This is the starting point for attachment of the dural substitute to the original dural opening near the apex of the IC (shown in Figure 2 just above the C2 spinous process, points "A" and "a"). To allow the rectangular graft to separate into an IC, a cut is made down the middle of the graft. The two arms of the rectangular graft are then spread out laterally to form the IC shape (Fig. 2C). Sutures are placed along each of the sides of the dural opening from "D" to "A" and from "C" to "A". It is helpful to place tacking sutures near the top of the opening (as outlined in the diagram at points "C" and "c" and "D" and "d"). At that point "B" and "b" may be approximated, and the arms of the rectangle, which have been now splayed apart, can be trimmed. This allows for a perfect fit to the posterior fossa opening.
Received, November 12, 1991. Accepted, December 30, 1991. Reprint requests: W.S. Fisher III, M.D., University of Alabama at Birmingham, 511 Medical Education Building, 1813 6th Ave., S., UAB Station, Birmingham, AL 35294. REFERENCES: (1-3) 1. 2. 3.
Fisher WS III, Six EG: Cervical myelopathy from dural substitute. Neurosurgery 13:715717, 1983. Kempe LG: Operative Neurosurgery, New York, Springer-Verlag, vol. 2, 1970. Webster's Seventh Collegiate Dictionary, Springfield, MA, G&C Merriam Co., 1965.
COMMENT The technique described for shaping a graft for posterior fossa dural closure is very helpful. Frequently, dissociation of the dura during prolonged posterior fossa surgery leads to retraction that makes it difficult to obtain a primary closure. In the past, this was not thought to be an important
Downloaded from https://academic.oup.com/neurosurgery/article-abstract/31/1/155/2752083 by East Carolina University user on 11 January 2019
Division of Neurosurgery, University of Alabama (WSF), Birmingham, Alabama, and Department of Neurosurgery, Naval Hospital Bethesda (DB), Bethesda, Maryland
DISCUSSION Dural reconstruction and interest in dural substitutes dates from 1897 when Beach suggested the use of gold foil to prevent meningocerebral adhesions. Since then, various substances have been used, including periosteum, fascia lata, metals, rubber, Celluloid plates, parchment, peritoneum, fat, muscle, omentum, cellophane, mica, dermal grafts, Cargile membrane, hernia sack, catgut, polyvinyl sponge, Gelfoam, fibrin, umbilical cord, Silastic, Teflon, freeze-dried dura mater, and methyl methacrylate (1). We prefer the use of cardiac pericardium at one of our institutions (University of Alabama) because of its flexibility and ability to stretch. However, if a tissue bank is not accessible, then commercially available products, including Tutoplast and Lyodura, must be used when autologous tissue is not available. Typically, these substances are stiff when first removed from their packages. By soaking these substances, they become more pliable, allowing for some stretching of the graft. Soaking alone may be insufficient to allow for correct manipulation and fashioning of the graft to fit the posterior fossa opening. Before using the IC closure, we frequently misjudged the fit of the graft to the opening. By splaying the graft arms apart, a better fit of the posterior fossa opening was possible. We have used this closure on most of our posterior fossa craniectomies where dural substitute is needed. The biggest error we have seen is that the vertical cut allowing for the two arms of the rectangle to be splayed apart (forming the IC) can be made too long, not allowing approximation of "b" to "B". Usually, this has to be such a long overcut that accidental extension of this incision is infrequent. To correct such an overcut, closure of the linear incision is made with a few additional stitches back to a point where "b" and "B" may be approximated.
Redistribution of this article permitted only in accordance with the publisher’s copyright provisions.
Neurosurgery 1992-98 July 1992, Volume 31, Number 1 155 Closure of Posterior Fossa Dural Defects Using a Dural Substitute: Technical Note Technical Note
Howard H. Kaufman Morgantown, West Virginia REFERENCES: (1) Kaufman HH, Carmel PC: The etiology of aseptic meningitis and hydrocephalus after posterior surgery. Acta Neurochir 44:179-196, 1978.
Redistribution of this article permitted only in accordance with the publisher’s copyright provisions.
1.
Downloaded from https://academic.oup.com/neurosurgery/article-abstract/31/1/155/2752083 by East Carolina University user on 11 January 2019
problem. The dura was frequently left open, and the closure begun at the level of the muscle. However, in those days, aseptic meningitis and even hydrocephalus were often seen after posterior fossa surgery, and a considerable amount of work was performed trying to determine the cause of this problem (1). Today, the trend is to obtain dural closure and this problem is less frequently seen. However, primary closure is often difficult, and the technique described for fashioning a graft of the proper shape to facilitate this closure is certainly helpful.
Redistribution of this article permitted only in accordance with the publisher’s copyright provisions.
Figure 2. Steps of the IC closure. A, the graft is cut so that one end is tapered. B, a vertical cut is made in the graft. C, the arms of the graft can then be splayed apart. D, the graft is sewn into the dural opening. Each upper-case letter is sewn to its corresponding lower-case letter. To simplify the technique, tack-up sutures are placed in the following order: "A" to "a," "D" to "d," and "C" to "c."
Downloaded from https://academic.oup.com/neurosurgery/article-abstract/31/1/155/2752083 by East Carolina University user on 11 January 2019
Figure 1. Military insignia composed of two parts: a, the "chevron" and b,. the "rocker arm." If the chevron is turned upside down, it forms the inverted chevron shape. This is the shape of the posterior fossa opening as described by Kempe (2).
