Decompressive craniotomy: durotomy instead of duroplasty to reduce prolonged ICP elevation

Hinge craniotomy versus standard decompressive hemicraniectomy: an experimental preclinical comparative study

INTRODUCTION

Decompressive craniectomy (DC) is the most common surgical procedure to manage increased intracranial pressure (ICP). Hinge craniotomy (HC), which consists of fixing the bone operculum with a pivot, is an alternative method conceived to avoid some DC-related complications; nonetheless, it is debated whether it can provide enough volume expansion. In this study, we aimed to analyze the volume and ICP obtained with HC using an experimental cadaver-based preclinical model and compare the results to baseline and DC.

METHODS

Baseline conditions, HC, and DC were compared on both sides of five anatomical specimens. Volume and ICP values were measured with a custom-made system. Local polynomial regression was used to investigate volume differences.

RESULTS

The area of the bone opercula resulting from measurements was 115.55 cm2; the mean supratentorial volume was 955 mL. HC led to intermediate results compared to baseline and DC. At an ICP of 50 mmHg, HC offers 130 mL extra space but 172 mL less than a DC. Based on local polynomial regression, the mean volume difference between HC and the standard craniotomy was 10%; 14% between DC and HC; both are higher than the volume of brain herniation reported in the literature in the clinical setting. The volume leading to an ICP of 50 mmHg at baseline was less than the volume needed to reach an ICP of 20 mmHg after HC (10.05% and 14.95% from baseline, respectively).

CONCLUSIONS

These data confirm the efficacy of HC in providing sufficient volume expansion. HC is a valid intermediate alternative in case of potentially evolutionary lesions and non-massive edema, especially in developing countries.

External-internal cranial expansion to treat patients with craniocerebral disproportion due to post-shunt craniosynostosis: a case series

INTRODUCTION

Secondary craniosynostosis subsequent to shunting is one of the late complications of ventricular shunt placement in the early childhood. Several interventions have been used to treat high intracranial pressure associated with this condition. This study aimed to evaluate the patients' clinical symptoms and head circumference before and after a method of decompressive craniotomy, coined as external-internal cranial expansion (EICE).

METHODS

A retrospective study was conducted, and the patients who had undergone EICE for the treatment of post-shunt craniosynostosis between 2010 and 2020 were enrolled. This approach was a combination of a hinge multiple-strut decompressive craniectomy and internal cranial flap thinning by drill. Data, extracted from medical records, were used to evaluate the patients' symptoms and head circumferences before and 12 months after surgery.

RESULTS

A total of 16 patients were enrolled in the study, of which eight were females. Before the surgery, 9 patients (56.2%) suffered from visual impairment, and all had intractable headache. Papilledema was recorded in all, with 3 cases having optic disc paleness. After cranial expansion, only two patients had headaches, diagnosed as migraine-type and psychosomatic headaches, respectively. In two patients, progressive visual impairments got worsening after surgery, which would be due to severe preoperative optic nerve atrophy. Patients' head circumferences significantly increased after the surgery (mean of 48.97 ± 4.28 cm vs. 45.78 ± 4.31 cm; P value < 0.0001).

CONCLUSION

In lower resource countries, where newer technologies like distraction osteogenesis is not easily available, external-internal cranial expansion can be considered an effective alternative for patients with post-shunt craniosynostosis.

Decompressive hinge craniectomy with linear durotomies for ischemic stroke: a pilot study

OBJECTIVE

Decompressive craniectomy may be a life-saving measure in ischemic stroke patients, who still have several associated complications. The objective of this study is to evaluate a novel decompressive surgery technique for severe hemispheric ischemic stroke.

METHODS

For the hinge decompressive craniectomy (HDC), linear durotomies were performed. Vertical (one or two frontal and two parietal), and two horizontal (temporal), with approximately 5 cm long, linear durotomies were carried out. Duroplasty was performed using an autologous subgaleal tissue graft fixed with separate sutures to avoid CSF leak and direct contact of the cortex with the bone flap. The bone flap was fixed in three parietal locations. We compared 10 patients who underwent our modified HDC with 9 patients submitted to classical decompressive craniectomy (CDC). The primary outcome of this study was mortality.

RESULTS

Nineteen patients were included, with a mean age of 52.3 years (±8.2). Four (44%) patients from the HDC group had to be reoperated to remove the bone flap because of brain swelling worsening, but none of them died. The average time of HDC was 90 minutes. Overall 14-days mortality was 21.1% (n=4), and cumulative six-months mortality was 42.1% (n=8). Five (50%) patients submitted to CDC died, while 3 (33.3%) submitted to HDC died (χ2=0.07, p=0.79). The mean length of stay was 46.7 days (±32.1) for HDC and 38.7 (±27.1) for CDC (p=0.60).

CONCLUSIONS

We present a modified technique of hinge craniectomy with linear vertical and horizontal durotomies, which seems to have reduced operative time and mortality compared to classical decompressive craniotomy, although the difference was not statistically significant.

Simple, Quick, and Safe Dural Incision Technique for Patients with Expected Brain Bulging during Decompressive Craniectomy: "Crank-shaped Dural Incisions"

Brain bulging is an unfavorable outcome in patients with brain swelling who require decompressive craniectomy (DC) to control elevated intracranial pressure (ICP). Although several previous studies have described methods for reducing the operation time during DC in these patients, few have proposed a technique for controlling brain protrusion. Here we describe an effective and simple method for external reduction of ICP and discuss its suitability for patients at risk of brain bulging during DC. After craniectomy, crank-shaped lines extending from a central square dural canopy are all marked on the dura. As the incisions are made, pressure from the swelling brain opens the lines and the protruding cortical surface forms dural windows. The square canopy gradually rotates as it stretches, and along with the remaining dura, functions to gently support and compress the cortex. In the case of insufficient decompression, the incision lines can be extended to further reduce ICP. As the parenchyma is accessible to the surgeon, hematoma removal can be performed through the dural windows. In initial experience of four patients who underwent this technique, ICP was controlled in all cases after surgery and no adverse events occurred. The crank-shaped dural incision method is a simple, quick, and effective technique for external reduction of ICP in patients at risk of brain bulging that is intuitive in the emergency situation and thus can be performed even by relatively inexperienced neurosurgeons.

Exploration of an Easy and Simple Method for Decompressive Craniectomy: The "Spiral Dural Incision Method"

Decompressive craniectomy (DC) is performed to alleviate intracranial hypertension as much as possible. There are two additional goals that surgeons should strive to achieve: minimization of operating time (i.e., the time issue) and avoidance of manually pushing on the surface of the bulging brain to prevent iatrogenic brain injury (i.e., “stuffing risk”). Many authors have made progress on the time issue, but stuffing risk remains largely unmitigated. We recently presented a new DC method that resolved both issues, but the incision design was too complicated for general use. A recent study has presented a duraplasty method that does not use watertight sutures and does not exacerbate the risk associated with DC. Employing the simplified method without sutures, we developed a new, easy-to-perform DC method that resolves stuffing risk. We analyzed the incision design geometrically and verified it by simulations generated with a physics engine. Three patients with massive cerebral infarction, subarachnoid hemorrhage, and hemorrhagic infarction underwent the new procedure. The targeted incision design was composed of four or five curved incision lines. Expansion of the dura resulted in transformation into a centroclinal form with spiral rifts and canopy. The dura expanded as expected in each case, and no cases required manual stuffing of the bulging brain. The operative time was acceptable, and no complications were reported. The concept of the incision design could be applied to any polygonal duraplasty in DC. We developed a new DC method that involves a simple and easily executed incision design, avoided stuffing risk.

Relationship between Clinical Outcomes and Superior Sagittal Sinus to Bone Flap Distance during Unilateral Decompressive Craniectomy in Patients with Traumatic Brain Injury: Experience at a Single Trauma Center

Objective

This retrospective study was conducted to investigate the relationship between the superior sagittal sinus (SSS) to bone flap distance and clinical outcome in patients with traumatic brain injury (TBI) who underwent decompressive craniectomy (DC).

Methods

A retrospective review of medical records identified 255 adult patients who underwent DC with hematoma removal to treat TBI at our hospital from 2016 through 2017; of these, 68 patients met the inclusion criteria and underwent unilateral DC. The nearest SSS to bone flap distances were measured on postoperative brain computed tomography images, and patients were divided into groups A (distance ≥20 mm) and B (distance <20 mm). The estimated blood loss (EBL) and operation time were evaluated using anesthesia records, and the time spent in an intensive care unit (ICU) was obtained by chart review. The clinical outcome was rated using the extended Glasgow Outcome Scale (GOS-E) at 3 and 6 months postoperatively.

Results

The male to female ratio was 15:2 and the mean subject age was 55.12 years (range, 18–79 years). The mean EBL and operation times were significantly different between groups A and B (EBL: 655.26 vs. 1803.33 mL, p<0.001; operation time: 125.92 vs. 144.83 min, p<0.001). The time spent in the ICU and GOS-E scores did not differ significantly between the groups.

Conclusion

We recommend that when DC is indicated due to TBI, an SSS to bone flap distance of at least 20 mm should be maintained, considering the EBL, operation time, and other outcomes.

Neural Vascular Mechanism for the Cerebral Blood Flow Autoregulation after Hemorrhagic Stroke

During the initial stages of hemorrhagic stroke, including intracerebral hemorrhage and subarachnoid hemorrhage, the reflex mechanisms are activated to protect cerebral perfusion, but secondary dysfunction of cerebral flow autoregulation will eventually reduce global cerebral blood flow and the delivery of metabolic substrates, leading to generalized cerebral ischemia, hypoxia, and ultimately, neuronal cell death. Cerebral blood flow is controlled by various regulatory mechanisms, including prevailing arterial pressure, intracranial pressure, arterial blood gases, neural activity, and metabolic demand. Evoked by the concept of vascular neural network, the unveiled neural vascular mechanism gains more and more attentions. Astrocyte, neuron, pericyte, endothelium, and so forth are formed as a communicate network to regulate with each other as well as the cerebral blood flow. However, the signaling molecules responsible for this communication between these new players and blood vessels are yet to be definitively confirmed. Recent evidence suggested the pivotal role of transcriptional mechanism, including but not limited to miRNA, lncRNA, exosome, and so forth, for the cerebral blood flow autoregulation. In the present review, we sought to summarize the hemodynamic changes and underline neural vascular mechanism for cerebral blood flow autoregulation in stroke-prone state and after hemorrhagic stroke and hopefully provide more systematic and innovative research interests for the pathophysiology and therapeutic strategies of hemorrhagic stroke.

Dynamic telescopic craniotomy: a cadaveric study of a novel device and technique

OBJECT

The authors assessed the feasibility of the dynamic decompressive craniotomy technique using a novel cranial fixation plate with a telescopic component. Following a craniotomy in human cadaver skulls, the telescopic plates were placed to cover the bur holes. The plates allow constrained outward movement of the bone flap upon an increase in intracranial pressure (ICP) and also prevent the bone flap from sinking once the ICP normalizes. The authors compared the extent of postcraniotomy ICP control after an abrupt increase in intracranial volume using the dynamic craniotomy technique versus the standard craniotomy or hinge craniotomy techniques.

METHODS

Fixation of the bone flap after craniotomy was performed in 5 cadaver skulls using 3 techniques: 1) dynamic telescopic craniotomy, 2) hinge craniotomy, and 3) standard craniotomy with fixed plates. The ability of each technique to allow for expansion during intracranial hypertension was evaluated by progressively increasing intracranial volume. Biomechanical evaluation of the telescopic plates with load-bearing tests was also undertaken.

RESULTS

Both the dynamic craniotomy and the hinge craniotomy techniques provided significant control of ICP during increases in intracranial volume as compared with the standard craniotomy technique. With the standard craniotomy, ICP increased from a mean of 11.4 to 100.1 mm Hg with the addition of 120 ml of intracranial volume. However, with the dynamic craniotomy, the addition of 120 ml of intracranial volume increased the ICP from a mean of 2.8 to 13.4 mm Hg, maintaining ICP within the normal range as compared with the standard craniotomy (p = 0.04). The dynamic craniotomy was also superior in controlling ICP as compared with the hinge craniotomy, providing expansion for an additional 40 ml of intracranial volume while maintaining ICP within a normal range (p = 0.008). Biomechanical load-bearing tests for the dynamic telescopic plates revealed rigid restriction of bone-flap sinking as compared with standard fixation plates and clamps.

CONCLUSIONS

The dynamic telescopic craniotomy technique with the novel cranial fixation plate provides superior control of ICP after an abrupt increase in intracranial volume as compared with the standard craniotomy and hinge craniotomy techniques.

Positive impact of pre-stroke surgery on survival following transient focal ischemia in hypertensive rats

We describe a positive influence of pre-stroke surgery on recovery and survival in a commonly used experimental stroke model. Two groups of male, stroke-prone spontaneously hypertensive rats (SHRSPs) underwent transient middle cerebral artery occlusion (tMCAO). Group 1 underwent the procedure without any prior intervention whilst group 2 had an additional general anaesthetic 6 days prior to tMCAO for a cranial burrhole and durotomy. Post-stroke recovery was assessed using a 32 point neurological deficit score and tapered beam walk and infarct volume determined from haematoxylin-eosin stained sections. In group 2 survival was 92% (n=12) versus 67% in group 1 (n=18). In addition, post-tMCAO associated weight loss was significantly reduced in group 2. There was no significant difference between the two groups in experimental outcomes: infarct volume (Group 1 317±18.6 mm³ versus Group 2 332±20.4 mm³), and serial (day 0-14 post-tMCAO) neurological deficit scores and tapered-beam walk test. Drilling a cranial burrhole under general anaesthesia prior to tMCAO in SHRSP reduced mortality and gave rise to infarct volumes and neurological deficits similar to those recorded in surviving Group 1 animals. This methodological refinement has significant implications for animal welfare and group sizes required for intervention studies.

Decompressive craniectomy with massive intractable intraoperative cerebral edema: utilization of silicone sheet for temporary scalp closure

The authors present a case of extreme brain herniation encountered during decompressive craniectomy in a 21-month-old boy who suffered a trauma event that necessitated temporary scalp closure in which a sterile silicone sheet was placed. Although the clinical situation is usually expected to lead to brain death or severe disability, the patient's 3-year follow-up examination revealed a highly functional child with a good quality of life. The authors discuss the feasibility and advantages of temporary scalp expansion as a treatment option when extreme brain herniation is encountered during craniotomy.

The importance of early brain injury after subarachnoid hemorrhage

Aneurysmal subarachnoid hemorrhage (aSAH) is a medical emergency that accounts for 5% of all stroke cases. Individuals affected are typically in the prime of their lives (mean age 50 years). Approximately 12% of patients die before receiving medical attention, 33% within 48 h and 50% within 30 days of aSAH. Of the survivors 50% suffer from permanent disability with an estimated lifetime cost more than double that of an ischemic stroke. Traditionally, spasm that develops in large cerebral arteries 3-7 days after aneurysm rupture is considered the most important determinant of brain injury and outcome after aSAH. However, recent studies show that prevention of delayed vasospasm does not improve outcome in aSAH patients. This finding has finally brought in focus the influence of early brain injury on outcome of aSAH. A substantial amount of evidence indicates that brain injury begins at the aneurysm rupture, evolves with time and plays an important role in patients' outcome. In this manuscript we review early brain injury after aSAH. Due to the early nature, most of the information on this injury comes from animals and few only from autopsy of patients who died within days after aSAH. Consequently, we began with a review of animal models of early brain injury, next we review the mechanisms of brain injury according to the sequence of their temporal appearance and finally we discuss the failure of clinical translation of therapies successful in animal models of aSAH.

Decompressive craniectomy bone flap hinged on the temporalis muscle: A new inexpensive use for an old neurosurgical technique

Background:

The neurosurgical procedure of hinge decompressive craniectomy (hDC), or hinge craniotomy (HC), as described from units in the advanced countries makes use of metallic implants, usually titanium plates and screws, which may not be economically viable in resource-limited practice settings.

Methods:

We describe our surgical techniques for performing this same procedure of hDC in a developing country using the patient's own temporalis muscle instead of any other potentially costly implants.

Results:

The technique as described appears to be successful in achieving intracranial decompression in cases of traumatic brain swelling in which it has been used. Clinical and radiological illustrations of the feasibility, and practical utility, of the procedures in four clinical scenarios of traumatic brain injury are presented. Like all other techniques of HC, this new surgical technique of hDC temporalis saves the survivors the added imperative of future cranioplasty of the usual postcraniectomy skull defect. Unlike the others, the procedure eliminates the added cost of the metallic implants needed to perform the former techniques.

Conclusions:

The procedure of hDC temporalis appears to be a viable option for performing the surgical procedure of HC and has added cost-cutting economic benefits for resource-limited practice settings.

Marked reduction in wound complication rates following decompressive hemicraniectomy with an improved operative closure technique

Although decompressive hemicraniectomy with dural expansion and bone flap removal is a potentially life-saving procedure, concerns remain regarding the morbidity associated with this approach. We and others have noted the high rate of wound complications resulting from this technique, often associated with cerebrospinal fluid (CSF) absorption problems. Here, we present our experience with an improved technique for wound closure after unilateral decompressive hemicraniectomy with a wide cruciate durotomy. Data for all patients who underwent a decompressive hemicraniectomy at our institution from October 2005 to October 2009 were gathered prospectively. Starting in mid 2008, we adopted an alternate approach to operative wound closure, which involved skin closure with a running Monocryl absorbable stitch, and prolonged subgaleal drainage. We compared the rates of wound complication using this approach with those obtained with earlier conventional closure techniques. Over a 1year period, we dramatically reduced the rate of wound complications in patients undergoing hemicraniectomy at our hospital using this new (Monocryl technique, 0% (n=29) compared to other techniques, 35% (n=98), chi-squared [χ(2)] p<0.001). Patients closed using our new technique experienced markedly reduced rates of wound infection (p<0.01), and CSF leak (p<0.05), compared to other, more standard, techniques. Thus, attention to closure of hemicraniectomy wounds can markedly reduce the rate of wound complications, thus improving the risk-to-benefit ratio of this procedure.