Surgical Neurology 70 (2008) 437 – 439 www.surgicalneurology-online.com
Technique
Double dural patch in decompressive craniectomy to preserve the temporal muscle: technical note Paolo Missori, MD4, Filippo Maria Polli, MD, Simone Peschillo, MD, Elena D’Avella, MD, Sergio Paolini, MD, Massimo Miscusi, MD Department of Neuroscience, Neurosurgery, University of Rome bLa SapienzaQ, Rome, Italy University of Perugia-IRCCS Neuromed-Pozzilli, Italy Received 12 August 2006; accepted 9 March 2007
Abstract
Background: In frontotemporal decompressive craniectomy and subsequent cranioplasty, temporal muscle damage is frequently observed as a result of surgical manipulation, lack of bone attachment, and prolonged muscle inactivity. We investigated the use of a double dural patch in decompressive craniectomy to favor the safe surgical dissection of the temporal muscle in the subsequent cranioplasty and reduce temporal muscle damage. Methods: In 11 patients submitted to a decompressive craniectomy and duraplasty, a second (external) dural sheet was positioned to separate the inner dural patch from the temporal muscle. Results: When bone repositioning was performed, the detachment of the deep temporal muscle surface, covered by the external dural sheet, was easy and fast, with reduced blood loss. All the muscle fibers were preserved. Conclusion: The technique described in this article reduces the damage to the temporal muscle and can improve the functional and cosmetic results after decompressive craniectomy and cranioplasty. D 2008 Elsevier Inc. All rights reserved.
Keywords:
Cranioplasty; Decompressive craniectomy; Dural patch; Intracranial hypertension; Temporal muscle
1. Introduction Decompressive craniectomy is a neurosurgical technique that allows reduction of the intracranial pressure. The bone removal must be coupled with a dural patch to allow the brain to expand as much as possible while the temporal muscle is reposed on the dural patch without any attachment. After some weeks or months, when the clinical course is favorable, the reconstruction of the cranial defect is performed. In most cases the temporal muscle, because of the prolonged elapsed time, is strongly adherent to the dural patch and commixed with a fibrotic tissue, which does not allow an uncomplicated surgical dissection. The result is dural patch laceration and widespread temporal muscle
4 Corresponding author. Neurochirurgia, Viale del Policlinico, 155, 00185 Roma, Italy. Tel.: +39 0649979118; fax: +39 064462980. E-mail address:
[email protected] (P. Missori). 0090-3019/$ – see front matter D 2008 Elsevier Inc. All rights reserved. doi:10.1016/j.surneu.2007.03.029
damage. A partial detachment of the muscle from the patch does not permit accurate repositioning of the bone flap. The effect in the rehabilitation phase is localized pain, impaired chewing, and last but not least, aesthetic alteration. We report a series of 11 patients with frontotemporal decompressive craniectomy in which a double dural patch was introduced to facilitate the dissection and to reduce damage to the temporal muscle in the late reconstructive procedure. 2. Materials and methods Ten males and 1 female underwent removal of posttraumatic subdural hematomas (9 patients) or intraparenchymal hemorrhage (2 patients). A hemicoronal skin incision partially extending on the contralateral side was accomplished, together with a straight cut perpendicular and posterior to the main incision (Fig. 1). After subcutaneous dissection, with preservation of the superficial temporal
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Fig. 1. Frontotemporoparietal craniectomy. The skin incisions are detailed by the red lines. Midline and coronal suture are represented by dotted lines. The white area reproduces the surface of the craniectomy. Modified from Raphael’s fresco: Dante Alighieri, Disputation over the Most Holy Sacrament, Room of the Segnatura (1508-1511), Vatican Museums.
Fig. 3. The drawing shows the final result. The internal dural patch is sutured to the patient’s dura mater. The craniectomy defect is outlined by green dotted line. The external dural patch (asterisk) conjoins to the temporal muscle and will be en bloc turned over with the subcutaneous tissue and the skin after bone repositioning.
artery, the temporal muscle exposed by the skin incision was cut with a surgical blade. The musculocutaneous flap was then en bloc dissected and reflected off. Coagulation was never used. In all cases, a frontotemporal bone flap was created using the usual technique—the posterior rim extending 3 cm back the coronal suture, the superior edge from 1 to 2 cm next to the midline, the anterior border just above the supraorbital rim, the inferior margin down to the temporal fossa. The total surface of such craniectomy is more than 100 cm2. Further enlargement may be easily obtained by posterior extension of the perpendicular straight cut. After dura opening, the collected blood was evacuated. A large Tutoplast pericardial bovine patch (internal patch) was sewn to the dural margins to allow easy brain expansion. A subdural, pressure-monitoring catheter was positioned. A second patch (external patch) was laid on the first and anchored to the temporobasal dura. Finally, the temporal muscle, subcutaneous tissue, and skin were turned over en bloc, and the skin boundaries were closed with absorbable sutures. After a mean time of 7 weeks, the patients underwent
bone repositioning. The previous skin incision was reopened, and after dissection of the subcutaneous tissue, a clear cleavage plane was identifiable between the internal and external dural patch (Fig. 2A). The external dural patch adhered strongly to the deep temporal muscle layer, and no attempts were done to detach it. A very thin connective layer was detectable between the internal and external dural grafts (Fig. 2B) and subsequently removed (Fig. 3). After drilling of the bone borders, the ethylene oxide–sterilized bone flap [2] was repositioned on the internal dural graft and fixed with titanium microplates. At the end of the procedure, the external dural patch conjoined to the temporal muscle, and the subcutaneous tissue were en bloc turned over. The skin was sutured with absorbable sutures. 3. Discussion Decompressive craniectomy has experienced a revival during past years, and many neurosurgical centers are currently applying it as a therapeutic tool in brain injury or
Fig. 2. A: The previous skin incision was reopened and, after dissection of the subcutaneous tissue, a clear cleavage plane was identifiable between the internal (whitish area) and external dural patch (asterisk). The craniectomy defect created by the decompressive craniectomy is outlined by green dotted line. The deep temporal muscle layer was covered by and adhered strongly to the outer surface of the external dural patch. B: A very thin connective layer was detectable between the internal and external dural grafts (arrows).
P. Missori et al. / Surgical Neurology 70 (2008) 437–439
hemorrhage. Nevertheless, the technique is not standardized, the beneficial effect is controversial, and some complications have been reported [4]. After a few postoperative weeks, the temporal muscle partly atrophies and adheres firmly to the dural patch. When the reconstructive surgery is planned, in most cases a cleavage plane is not detected, and the surgeon is forced to sacrifice some muscle fibers or to leave the temporal muscle adhering to the temporobasal dural patch area. To avoid such complications, the use of expanded polytetrafluoroethylene membrane for prevention of adhesions in cranioplasty has been reported [1]. When frozen bone was repositioned, no adhesions were observed between the membranes and the temporal muscle or the dura. Reduced operating time and blood loss were reported, without postoperative complications. These good results were tempered by subsequent data in which a 14.3% rate of infection was reported in 56 expanded polytetrafluoroethylene sheets for duraplasty [3]. After that, no new attempts have been reported in the literature to resolve this surgical dilemma. Many processed biologic tissues of human and animal origin are currently used in neurosurgical procedures, with no complications and good results. A heterologous double dural patch in decompressive craniectomy appears to be a simple and effective technique by which to preserve the temporal muscle fibers. Blood loss is reduced, and no infections developed in our series. Moreover, these results can contribute improved chewing and aesthetic outcome.
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Commentary This is a novel and interesting solution to a commonly encountered problem. The use of a heterologous double dural patch to preserve temporal muscle fibers is a straightforward technique that can be performed by any neurosurgeon already performing decompressive craniectomy. The authors concede that many processed biologic tissues of human and animal origin are used in neurosurgical procedures. This series used the Tutoplast pericardial bovine patch for the double dural repair. Readers must either use this same material or conduct their own series with a different patch graft, as there is no evidence that other substrates will behave similarly. In addition, although the authors report no incidence of infection, placing avascular tissue against avascular tissue creates an avascular pocket with a greater potential for infection and abscess formation. If these limitations are taken into consideration, the use of this technique may improve the aesthetic outcome and chewing ability in patients undergoing cranioplasty after decompressive craniectomy.
Christopher J. Abood, MD Mid-Michigan Neurosurgical Associates Lansing, MI 48912, USA
References [1] Kawaguchi T, Hosoda K, Shibata Y, Koyama J. Expanded polytetrafluoroethylene membrane for prevention of adhesions in patients undergoing external decompression and subsequent cranioplasty. Neurol Med Chir (Tokyo) 2003;43:320 - 3. [2] Missori P, Polli FM, Rastelli E, Baiocchi P, Artizzu S, Rocchi G, Salvati M, Paolini S, Delfini R. Ethylene oxide sterilization of autologous bone flaps following decompressive craniectomy. Acta Neurochir (Wien) 2003;145:899 - 902. [3] Nakagawa S, Hayashi T, Anegawa S, Nakashima S, Shimokawa S, Furukawa Y. Postoperative infection after duraplasty with expanded polytetrafluoroethylene sheet. Neurol Med Chir (Tokyo) 2003; 43:120 - 4. [4] Yang XJ, Hong GL, Su SB, Yang SY. Complications induced by decompressive craniectomies after traumatic brain injury. Chin J Traumatol 2003;6:99 - 103.
Missori et al present what they have found to be a solution to a problem encountered by many neurosurgeons during performance of a cranioplasty after a decompressive craniectomy during which a duraplasty was also done. They report no complications in the 11 patients in whom the technique was used. Based on their report, neurosurgeons should consider trying this technique.
Robert Goodkin, MD Department of Neurosurgery University of Washington Medical Center Seattle, WA 98195, USA
