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|Year : 2022 | Volume
| Issue : 4 | Page : 1622-1624
Postoperative Salvage Decompressive Craniotomy: Usefulness of The Simple Posteriorly Directed Release Incision in Adequately Expanding Frontotemporal Flaps
Prasad Krishnan1, Nabanita Ghosh2
1 Department of Neurosurgery, National Neurosciences Centre, Calcutta, West Bengal, India
2 Department of Neuroanesthesiology, National Neurosciences Centre, Calcutta, West Bengal, India
|Date of Submission||01-Jul-2021|
|Date of Decision||14-Oct-2021|
|Date of Acceptance||18-Oct-2021|
|Date of Web Publication||30-Aug-2022|
Department of Neurosurgery, National Neurosciences Centre, 2nd Floor, Peerless Hospital Campus, 360, Panchasayar, Garia, Kolkata - 700 094, West Bengal
Source of Support: None, Conflict of Interest: None
Salvage decompressive craniotomies performed following complications after initial planned craniotomies may be inadequate if they are only restricted to removal of the small previously replaced bone flap with some additional nibbling of bone from the surrounding craniotomy margins by retracting the skin. To achieve the aim of adequately decreasing intracranial pressure without affecting wound healing, fresh incisions need to be placed to expand the craniotomy adequately while not compromising vascularity of the scalp. The rationale and safety of the simple posteriorly placed release incision to expand frontotemporal flaps is described.
Keywords: CSF leak, decompressive craniotomy, flap necrosis, frontotemporal flap, intracranial pressure, salvage decompressive craniotomy
Key Message: Salvage decompressive craniotomies done for complications after an initial surgery with a small bone flap need placement of fresh incisions that maintain skin vascularity (for subsequent good wound healing) and enable adequate bone removal (to decrease raised intracranial pressure).
|How to cite this article:|
Krishnan P, Ghosh N. Postoperative Salvage Decompressive Craniotomy: Usefulness of The Simple Posteriorly Directed Release Incision in Adequately Expanding Frontotemporal Flaps. Neurol India 2022;70:1622-4
|How to cite this URL:|
Krishnan P, Ghosh N. Postoperative Salvage Decompressive Craniotomy: Usefulness of The Simple Posteriorly Directed Release Incision in Adequately Expanding Frontotemporal Flaps. Neurol India [serial online] 2022 [cited 2023 Dec 8];70:1622-4. Available from: https://www.neurologyindia.com/text.asp?2022/70/4/1622/355163
Decompressive craniotomy is often the only tool available to treat raised intracranial pressure (ICP) refractory to medical measures and is now used for a wide variety of indications. When decompressive craniotomy is done as the primary surgery (as in infarcts, traumatic brain injury, etc.), a large skin flap is reflected that allows for adequate bone removal. However, there are some instances where a decompressive craniotomy may be required postoperatively as a result of unanticipated complications such as infarction, parenchymal hemorrhage, or cerebral edema in the aftermath of craniotomies done for conditions such as aneurysm clipping or tumor removal wherein initially a smaller flap tailored for the desired exposure had been raised. In such cases, merely reopening the previous incision and removing the bone flap may not result in an adequate decompression and reduction of the raised ICP and the surgeon needs to innovate to remove more of the skull without compromising on flap vascularity.
In frontotemporal craniotomies, a commonly used method in such a crisis is to retract the “non-reflected” skin margins away from the craniotomy site with sutures or hooks after reopening the previous incision and then expand the craniotomy. The drawback is that this seldom provides additional bony exposure of even 2 cm; thus, of even 2 cms and thus does not provide for adequate decompression unless accompanied by a lobectomy.
Posterior release incision: Steps and advantages
We prefer to increase bony exposure greatly by placing a straight incision (4–5 cm in length) that proceeds posteriorly from the curved frontotemporal flap raised previously and stripping the pericranium and temporalis away from the operative field. The location of such incision can be varied depending on whether predominantly temporal exposure or parietal exposure is needed [Figure 1]a. This enables raising skin flaps in three directions, each with a defined vascular supply, the initial anteroinferior flap being fed by the superficial temporal and supraorbital vessels, the posteroinferior flap being supplied by the posterior auricular and occipital vessels, and the posterosuperior flap being supplied by contralateral scalp vessels [Figure 1]a. This incision also enables adequate bone removal well behind the pinna [Figure 1]b, akin to what can be achieved by a large “?” mark or reverse “?” mark shaped flap, something that cannot be achieved by merely pulling back the limb of the previous flap and which if accompanied by generous inferior bone removal can mitigate any medial pressure on the tentorial hiatus. Posteriorly and superiorly too, bone removal can be tailored to even approach midline if required and decompress the posterior frontal and parietal lobes. During exposure, a good amount of pericranium and muscle can be raised, which after durotomy can be laid on the brain and aids in duraplasty. The small straight incision can be closed easily, with care only being taken to approximate the edges at its origin from the primary wound with a subcuticular suture going through the galea of all three flaps prior to a tension-free skin closure as blackening of the skin at the origin of the release incision is a concern.
|Figure 1: Schematic (a) showing the initial line of incision in a frontotemporal craniotomy for an aneurysm (blue line) and the posterior extension (solid black line) that can be used when a salvage decompressive craniotomy is considered with other possible trajectories (dotted black lines). The vessels on which the flaps can be based are also shown and named while (b) shows the initial bone removed (shaded in black) and what can be further removed (shaded in red) during salvage decompressive craniotomy by this technique|
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We have used this technique in five cases that deteriorated postoperatively: three of aneurysm clipping and two of sphenoid wing meningiomas; in all cases, we managed to expand the initial small craniotomy to more than 13 cm anteroposteriorly and 10 cm superoinferiorly [Figure 2] and [Figure 3]. There were no wound healing problems or cerebrospinal fluid (CSF) leak in any case.
|Figure 2: Operative pictures showing (a) the posterior extension arising from the initial skin incision marked and infiltrated after painting and draping before reoperation, (b) the replaced bone flap has been removed and more bone has been exposed that will be subsequently removed as part of the decompressive craniotomy, (c) bulge at the initial durotomy site with further dural exposure following decompressive craniotomy, (d) after stellate durotomy has been done, (e) a comparison of the initial old bone flap with further newly removed bone (in two pieces) to show how much additional decompression has been achieved, (f) careful closure at the tri-junction to prevent CSF leak and (g) length of the incision shown prior to beginning the skin closure|
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|Figure 3: Initial postoperative computed tomography (CT) scan after clipping of right middle cerebral artery bifurcation aneurysm, (b) CT scan after patient deteriorated due to edema and infarct after 4 postoperative days with midline shift and elevation of the bone flap, (c) CT scan after removal of the bone flap with a decrease in midline shift, (d) 3D reconstruction showing the size of the craniotomy at the first surgery and (e) 3D reconstruction showing the size of the decompressive craniotomy defect|
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| » Discussion|| |
A small decompressive craniotomy for raised ICP is a self-defeating surgery as external cerebral herniation through the small gap can cause venous obstruction of the brain at the edges of the defect, further increasing cerebral edema. Thus, after an initial small craniotomy, if postoperative complications necessitate a salvage decompression to relieve raised ICP, mere removal of the small bone flap created initially with expansion of the margins of the initial defect by nibbling a bit of skull at the edges of the craniotomy flap may prove inadequate. One option the surgeon then has is to proceed with a lobectomy to allow space for the brain to expand after nibbling the bone at the craniotomy margins; another option is to expand the craniotomy itself by placing an additional incision.
Rienzo et al. stated that the recommended posterior extension of unilateral decompressive skin flaps for adequate bone removal is 2–3 cm behind the ear which can never be done by merely retracting the frontotemporal flap that is raised electively for surgeries such as anterior circulation aneurysm clipping or tumors in the sphenoidal ridge or suprasellar region as happened in our cases. Thus, placement of a posteriorly directed limb from the main wound is a solution that should be tried as additional bony removal is more extensive once this is done and skin flaps are raised.
Various extensions of skin incisions have been described to expose and remove more bone during decompressive craniectomy while preserving skin vascularity, the most famous being the L G Kempe incision (midline sagittal with a vertical “T” bar extension) and an n-shaped incision as described by Yang et al. (which utilizes two roughly concentric incisions one behind another). These are based on the superficial temporal artery and posterior auricular with occipital arteries, respectively, for the anterior and posterior skin flap vascular supply. However, both have been used in the context where decompressive craniotomies were the initial surgery and not in the setting of a salvage decompression following an initial craniotomy.
The posterior extension technique described here is not novel and would undoubtedly have been done several times previously, but strangely, neither the steps nor its advantages have been mentioned in the literature. It allows for adequate removal of additional bone both superiorly and inferiorly behind the initial flap and does not compromise the vascularity of the scalp and allows for good wound healing.
| » Conclusion|| |
Use of such an extension is not to be advocated when primarily a decompressive craniotomy is contemplated, but it may be a useful adjunct in expanding smaller frontotemporal or pterional flaps if an unanticipated need for a salvage decompressive craniotomy arises postoperatively.
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Conflicts of interest
There are no conflicts of interest.
| » References|| |
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[Figure 1], [Figure 2], [Figure 3]