Ethylene oxide gas sterilization: a simple technique for storing explanted skull bone. Technical note

The authors evaluated the effectiveness of a simple technique using ethylene oxide (EtO) gas sterilization and room temperature storage of autologous bone grafts for reconstructive cranioplasty following decompressive craniectomy. The authors retrospectively analyzed data in 103 consecutive patients who underwent cranioplasty following decompressive craniectomy for any cause at the University of Illinois at Chicago between 1999 and 2005. Patients with a pre-existing intracranial infection prior to craniectomy or lost to follow-up before reconstruction were excluded. Autologous bone grafts were cleansed of soft tissue, hermetically sealed in sterilization pouches for EtO gas sterilization, and stored at room temperature until reconstructive cranioplasty was performed. Cranioplasties were performed an average of 4 months after decompressive craniectomy, and the follow-up after reconstruction averaged 14 months. Excellent aesthetic and functional results after single-stage reconstruction were achieved in 95 patients (92.2%) as confirmed on computed tomography. An infection of the bone flap occurred in eight patients (7.8%), and the skull defects were eventually reconstructed using polymethylmethacrylate with satisfactory results. The mean preservation interval was 3.8 months in patients with uninfected flaps and 6.4 months in those with infected flaps (p = 0.02). A preservation time beyond 10 months was associated with a significantly increased risk of flap infection postcranioplasty (odds ratio [OR] 10.8, p = 0.02). Additionally, patients who had undergone multiple craniotomies demonstrated a trend toward increased infection rates (OR 3.0, p = 0.13). Data in this analysis support the effectiveness of this method, which can be performed at any institution that provides EtO gas sterilization services. The findings also suggest that bone flaps preserved beyond 10 months using this technique should be discarded or resterilized prior to reconstruction.     

Preservation of the temporal muscle during the frontotemporoparietal approach for decompressive craniectomy: Technical note

Background

In patients undergoing decompressive craniectomy, resection and detachment of the temporal muscle produces esthetic and functional damage, due to atrophy of the frontal portion of the temporal muscle in the temporal fossa. We have performed en-block temporal muscle detachment in decompressive craniectomy patients to avoid esthetic and functional damage to the temporal muscle.

Methods

Twenty-one patients underwent decompressive craniectomy using a frontotemporoparietal approach. Through a three-leaf clover flap skin incision, the temporal muscle was detached en-block and overturned antero-inferiorly conjoined with the frontal myocutaneous flap. A decompressive craniectomy and duraplasty were performed. A polyethylene sheet was added to prevent adherence of the temporal muscle to the dura mater.

Results

The decompressive craniectomy was effective in all patients. When subsequent cranioplasty was performed, the temporal muscle was easily repositioned. No complications resulted from the en-block temporal muscle detachment or the use of the polyethylene sheet. In 18 patients eligible for clinical and radiological follow-up, excellent (n?=?4) or good (n?=?14) esthetic results were detected. Chewing ability is considered normal by all patients.

Conclusion

Although it requires that the patient undergo two surgical procedures, en-block detachment of the temporal muscle during decompressive craniectomy allows good esthetic and functional results.     

Osteoplastic decompressive craniotomy--an alternative to decompressive craniectomy

Background  

In spite of various degrees of brain expansion, decompressive surgery is usually carried out using decompressive craniectomy (DC). After craniectomy it is necessary to perform cranioplasty, which prolongs hospitalization and is not always without complications. Hence, in situations when cranial decompression is indicated, but DC would be too radical, we do not remove the bone flap, and we perform so-called osteoplastic decompressive craniotomy (ODC). The technique is detailed.     

Cranioplasty with autologous cryopreserved bone after decompressive craniectomy. Complications and risk factors for developing surgical site infection

Background

Renewed interest has developed in decompressive craniectomy, and improved survival is shown when this treatment is used after malignant middle cerebral artery infarction. The aim of this study was to investigate the frequency and possible risk factors for developing surgical site infection (SSI) after delayed cranioplasty using autologous, cryopreserved bone.

Methods

This retrospective study included 74 consecutive patients treated with decompressive craniectomy during the time period May 1998 to October 2010 for various non-traumatic conditions causing increased intracranial pressure due to brain swelling. Complications were registered and patient data was analyzed in a search for predictive factors.

Results

Fifty out of the 74 patients (67.6 %) survived and underwent delayed cranioplasty. Of these, 47 were eligible for analysis. Six patients (12.8 %) developed SSI following the replacement of autologous cryopreserved bone, whereas bone resorption occurred in two patients (4.3 %). No factors predicted a statistically significant rate of SSI, however, prolonged procedural time and cardiovascular comorbidity tended to increase the risk of SSI.

Conclusions

SSI and bone flap resorption are the most frequent complications associated with the reimplantation of autologous cryopreserved bone after decompressive craniectomy. Prolonged procedural time and cardiovascular comorbidity tend to increase the risk of SSI.     

Decompressive craniectomy for severe traumatic brain injury: The relationship between surgical complications and the prediction of an unfavourable outcome

Object

To assess the impact that injury severity has on complications in patients who have had a decompressive craniectomy for severe traumatic brain injury (TBI).

Methods

This prospective observational cohort study included all patients who underwent a decompressive craniectomy following severe TBI at the two major trauma hospitals in Western Australia from 2004 to 2012. All complications were recorded during this period. The clinical and radiological data of the patients on initial presentation were entered into a web-based model prognostic model, the CRASH (Corticosteroid Randomization After Significant Head injury) collaborators prediction model, to obtain the predicted risk of an unfavourable outcome which was used as a measure of injury severity.

Results

Complications after decompressive craniectomy for severe TBI were common. The predicted risk of unfavourable outcome was strongly associated with the development of neurological complications such as herniation of the brain outside the skull bone defects (median predicted risk of unfavourable outcome for herniation 72% vs. 57% without herniation, p = 0.001), subdural effusion (median predicted risk of unfavourable outcome 67% with an effusion vs. 57% for those without an effusion, p = 0.03), hydrocephalus requiring ventriculo-peritoneal shunt (median predicted risk of unfavourable outcome 86% for those with hydrocephalus vs. 59% for those without hydrocephalus, p = 0.001), but not infection (p = 0.251) or resorption of bone flap (p = 0.697) and seizures (0.987). We did not observe any associations between timing of cranioplasty and risk of infection or resorption of bone flap after cranioplasty.

Conclusions

Mechanical complications after decompressive craniectomy including herniation of the brain outside the skull bone defects, subdural effusion, and hydrocephalus requiring ventriculo-peritoneal shunt were more common in patients with a more severe form of TBI when quantified by the CRASH predicted risk of unfavourable outcome. The CRASH predicted risk of unfavourable outcome represents a useful baseline characteristic of patients in observational and interventional trials involving patients with severe TBI requiring decompressive craniectomy.     

Long-term complications of decompressive craniectomy for head injury

There is currently much interest in the use of decompressive craniectomy for intracranial hypertension. Though technically straightforward, the procedure is not without significant complications. A retrospective analysis was undertaken of 164 patients who had had a decompressive craniectomy for severe head injury in the years 2004 to 2009 at the two major hospitals in Western Australia. Eighty-six patients had a bifrontal decompression and seventy-eight had a unilateral decompression. Two patients died due to post-operative care issues. Complications attributable to the decompressive surgery were: herniation of the cortex through the bone defect (42 patients, 25.6%), subdural effusion (81 patients, 49.4%), seizures (36 patients, 22%), hydrocephalus (23 patients, 14%), and syndrome of the trephined (2 patients, 1.2%). Complications attributable to the subsequent cranioplasty included: sudden death due to massive cerebral swelling in 3 patients (2.2%), infection requiring removal of the bone flap in 16 patients (11.6%), and bone flap resorption requiring augmentation in 10 patients (7.2%). After excluding simple complications such as subdural effusion and brain herniation through the skull defect and some patients who died as a direct consequence of traumatic brain or extracranial injury, 81 patients (55.5%) had at least one complication after decompressive craniectomy. The occurrence of at least one complication after decompressive craniectomy was significantly associated with an increased risk of prolonged stay in the hospital or rehabilitation facility (odds ratio 2.54, 95%confidence interval 1.22,5.24, p=0.013), after adjusting for predicted risk of unfavorable outcome.     

Histopathology of subcutaneously preserved autologous bone flap after decompressive craniectomy: a prospective study

Background

Limited reports are available regarding the viability of subcutaneously preserved autologous bone flaps after decompressive craniectomy. The present study was undertaken to evaluate the histopathological changes in these autologous bone flaps.

Methods

Between January 2011 and July 2012, 50 patients were prospectively studied at the time of cranioplasty. Bone flap retrieved from the abdominal wall was subjected to histopathological examination to look for mononuclear cell infiltration into the Haversian system, presence of osteocytes, osteoblastic activity, angiogenesis and new bone formation. Microbiological culture of bone specimens was also done.

Results

Of the 50 patients, there were 40 cases of trauma, 6 of aneurysmal bleed, 2 of tumor, and a single case of intracerebral hemorrhage and middle cerebral artery infarct, respectively. Mean age of the patients was 35.8 years (range, 10–64 years). Histopathological examination revealed the presence of osteocytes in 86 %, which indicates the viability of bone flaps. Osteoblastic activity was noted in 38 % and angiogenesis in 14 % of bone flaps, respectively. New bone formation was found in 6 %, and all had underlying osteoblastic activity. No significant correlation was found between the presence of osteocytes, osteoblasts, angiogenesis and duration of preservation of bone flaps. Acinetobacter species were cultured in a single patient. However, there was no evidence of clinical infection.

Conclusions

Subcutaneously preserved bone flap in the anterior abdominal wall remains viable and retains its osteogenic potential, and it is a simple, cost-effective option for storage of bone flaps during decompressive craniotomy. It has a negligible infection rate.     

Relevance of ICP and ptiO<Subscript>2</Subscript> for indication and timing of decompressive craniectomy in patients with malignant brain edema

Summary Background. The exact effects of decompressive craniectomy on intracranial pressure (ICP) and cerebral tissue oxygenation (ptiO₂) are still unclear. Therefore, we have monitored ICP and ptiO₂ intra-operatively and correlated these values to different operative steps during craniectomy.Methods. ICP and ptiO₂ values have been monitored both, simultaneously and continuously, in 15 patients with cerebral edema due to posttraumatic or postischemic brain swelling. Indications for craniectomy were an increase in ICP above 25 mmHg or a decrease in ptiO₂ below 10 mmHg resistant to conservative treatment (e.g. mannitol, hyperventilation, adequate arterial blood oxygenation, etc.). In all cases, we performed a fronto-temporo-parietal craniectomy (15×12 cm) and dura enlargement with galea-periosteum. During craniectomy, monitoring of ICP and ptiO₂ in the affected hemisphere was continued. Values were recorded and correlated with the different operative steps.Findings. We performed craniectomy according to our treatment protocol in 5 patients. Prior to surgery, mean ICP values were 25.6 mmHg (range: 23–29 mmHg), mean ptiO₂ values were 5.9 mmHg (range: 2.4–9.5 mmHg), and mean CPP values were 66 mmHg (range: 60–70 mmHg). After removing the bone flap, ICP values dropped to physiological values (mean: 7.4 mmHg), whereas ptiO₂ values increased only slightly (mean: 11 mmHg). Opening of the dura resulted in a further decrease of ICP (mean 4.8 mmHg) and an increase of ptiO₂ to normal limits (mean: 18.8 mmHg). After skin closure, mean ICP was 6.8 mmHg and mean ptiO₂ was 21.7 mmHg, respectively. We found a significant decrease of ICP after craniectomy (p<0.042) and after dura enlargement (p<0.039) as well as a statistically significant increase in ptiO₂ after craniectomy (p<0.043) and after dura enlargement (p<0.041).Conclusion. As a large bone flap in decompressive craniectomy is essential for adequate ICP reduction, the results of the presented cases suggest that dura enlargement is the crucial step to restore adequate brain tissue oxygenation and that ptiO₂ monitoring could be an important tool for timing craniectomy in the future.     

Improved brain protection at decompressive craniectomy--a new method using Palacos R-40 (methylmethacrylate)

A new method is described for protecting the brain after decompressive craniectomy in which a temporary methylmethacrylate flap is formed, somewhat larger than the original bone flap, thus gaining "extra" volume for the oedematous brain in which to expand. The present procedure was developed as a part of ordinary clinical practice particularly in response to demands from the NICU staff and our colleagues at other clinics who were responsible for the care of the patient in the post NICU period. They made us keenly aware that these patients frequently lack optimal co-ordination and balance and therefore run an increased risk of trauma to the unprotected brain when falling. This prompted us to develop a method for brain protection after decompressive craniectomy aiding in the care and rehabilitation until the final installation of the patient's own bone flap can be performed.     

Effect of microorganisms isolated by preoperative osseous sampling on surgical site infection after autologous cranioplasty: A single-center experience

PurposeThe most frequent postoperative complication in autologous cranioplasty (AC) is infection. European recommendations include osseous sampling before cryogenic storage of a bone flap. We evaluated the clinical impact of this sampling.MethodsAll patients who underwent decompressive craniectomy (DC) and AC in our center between November 2010 and September 2021 were reviewed. The main outcome was the rate of reoperation for infection of the cranioplasty. We evaluated risk factors for bone flap infection, rate of reoperation for any reason (hematoma, skin erosion, cosmetic request, or bone resorption), and radiological evidence of bone flap resorption.ResultsA total of 195 patients with a median age of 50 (interquartile range: 38.0–57.0) years underwent DC and AC between 2010 and 2021. Of the 195 bone flaps, 54 (27.7%) had a positive culture, including 48 (88.9%) with Cutibacterium acnes. Of the 14 patients who underwent reoperation for bone flap re-removal for infection, 5 and 9 had positive and negative bacteriological cultures, respectively. Of patients who did not have bone flap infection, 49 and 132 had positive and negative bacteriological cultures, respectively. There were no significant differences between patients with and without positive bacteriological culture of bone flaps in the rates of late bone necrosis and reoperation for bone flap infection.ConclusionsA positive culture of intraoperative osseous sampling during DC is not associated with a higher risk of re-intervention after AC.     

Long-term complications and implant survival rates after cranioplastic surgery: a single-center study of 392 patients

Cranioplasty (CP) is a standard procedure in neurosurgical practice for patients after (decompressive) craniectomy. However, CP surgery is not standardized, is carried out in different ways, and is associated with considerable complication rates. Here, we report our experiences with the use of different CP materials and analyze long-term complications and implant survival rates. We retrospectively studied patients who underwent CP surgery at our institution between 2004 and 2014. Binary logistic regression analysis was performed in order to identify risk factors for the development of complications. Kaplan-Meier analysis was used to estimate implant survival rates. A total of 392 patients (182 females, 210 males) with a mean age of 48 years were included. These patients underwent a total of 508 CP surgeries. The overall complication rate of primary CP was 33.2%, due to bone resorption/loosening (14.6%) and graft infection (7.9%) with a mean implant survival of 120?±?5 months. Binary logistic regression analysis showed that young age (<?30 years) (p?=?0.026, OR 3.150), the presence of multidrug-resistant bacteria (p?=?0.045, OR 2.273), and cerebrospinal fluid (CSF) shunt (p?=?0.001, OR 3.137) were risk factors for postoperative complications. The use of titanium miniplates for CP fixation was associated with reduced complication rates and bone flap osteolysis as well as longer implant survival rates. The present study highlights the risk profile of CP surgery. Young age (<?30 years) and shunt-dependent hydrocephalus are associated with postoperative complications especially due to bone flap autolysis. Furthermore, a rigid CP fixation seems to play a crucial role in reducing complication rates.

     

Reconstruction of Suboccipital Craniectomy with Autologous Bone Chips

Summary.  Background: In patients submitted to suboccipital craniectomy in whom the bone is not repositioned, there may be a significant aesthetic defect due to lack of bone tissue, sometimes accompanied by paresthaesia and painful symptoms.  Method: In 15 patients submitted to suboccipital craniectomy, the bone chips were repositioned during wound closure.  Findings: At a mean follow up of 19 months (from 6 to 36 months), 2 patients (13%) complained of mild wound discomfort or occasional local pain. Twelve patients underwent control CT-scan. In three cases (25%) the bone fragments had been partly reabsorbed whereas in the other 9 (75%) they either formed a thin (4 patients) or consistent (5 patients) bony wall, with variable degree of adaptation to the contour of the contralateral occipital bone. The best cosmetic and functional results were obtained in young patients in whom the cerebellar parenchyma was well-preserved, as opposed to those in whom a CSF collection had replaced areas of cerebellar tissue.  Interpretation: In the majority of cases in whom an osteoplastic suboccipital craniotomy is not possible, repositioning of the bone chips from suboccipital craniectomy is able to restore a bone table, thus allowing morphological and functional recovery of the occipital region. Published online September 2, 2002 Correspondence: Missori Paolo, M.D., Neurotraumatologia, Policlinico Umberto I, Viale del Policlinico 155, 00161 Rome, Italy.     

Quality of life after decompressive craniectomy in patients suffering from supratentorial brain ischemia

Summary Background. Decompressive craniectomy in patients suffering from severe ischemic stroke in the middle cerebral artery territory (MCA) decreases mortality to near 30%. Additionally functional outcome in patients after early craniectomy seems to be better than in patients without surgery. The aim of this study was to investigate the quality of life of patients who were treated with a decompressive craniectomy for severe ischemic stroke. Methods. We retrospectively investigated the patient records of 48 patients (26 men, mean age 48 years) suffering from ischemic strokes who underwent craniectomy since 1993. We registrated the preoperative neurological status, the diagnostic data as well as the operative procedure. The outcome was assessed using the Barthel Index, the Glasgow outcome score and a questionnaire to assess the quality of life according to Blau consisting of eleven items at follow-up. Findings. The mortality rate was 26%, age correlated to mortality (44.5 versus 60.3 years GOS 1, mean, p<0.0006). Craniectomy without dura patch correlated to mortality (58% versus 14% GOS 1 with dura patch, p<0.005). The quality of life index was 6 points mean. The quality of life index did neither differ significantly between patients with left or right sided lesions nor in patients with and without aphasia. 83% of the surviving patients and/or dependents would agree to surgery in the future. Conclusion. Despite the fact that some patients remain in a poor neurological condition, quality of life after decompressive surgery for ischemic stroke seems to be acceptable to the patients.     

Improved brain protection at decompressive craniectomy – a new method using Palacos<Superscript>⌖</Superscript> R-40 (methylmethacrylate)

Summary A new method is described for protecting the brain after decompressive craniectomy in which a temporary methylmethacrylate flap is formed, somewhat larger than the original bone flap, thus gaining extra volume for the oedematous brain in which to expand.The present procedure was developed as a part of ordinary clinical practice particularly in response to demands from the NICU staff and our colleagues at other clinics who were responsible for the care of the patient in the post NICU period. They made us keenly aware that these patients frequently lack optimal co-ordination and balance and therefore run an increased risk of trauma to the unprotected brain when falling. This prompted us to develop a method for brain protection after decompressive craniectomy aiding in the care and rehabilitation until the final installation of the patients own bone flap can be performed.     

Unusual cause of rhabdomyolysis in a head injury patient: case report

There has been renewed interest in decompressive craniectomy as a treatment for severe closed head injury. Although generally considered a last resort measure, some neurologic surgeons now believe the procedure has merit early in the treatment hierarchy. (1,2) A positive effect on patient outcome has not yet been convincingly demonstrated. (3) We report an unusual complication of decompressive craniectomy, significant rhabdomyolysis caused by temporary storage of a bone flap in the anterior abdominal wall.     

Outcome following evacuation of acute subdural haematomas: a comparison of craniotomy with decompressive craniectomy

Background  

Acute subdural haematomas (ASDH) occur commonly following traumatic brain injury and may be evacuated by either craniotomy (CR) or decompressive craniectomy (DC). We reviewed a series of consecutive patients undergoing evacuation of a traumatic ASDH at a regional centre, comparing observed clinical outcomes (assessed by Glasgow Outcome Scale at six months) with those predicted by the CRASH-CT prognostic model.     

Construction of titanium cranioplasty plate using craniectomy bone flap as template

In recent times a steady rise in cranioplasty operations has been noted because of increasing utilisation of decompressive craniectomy for trauma as well as stroke patients. A variety of techniques have been utilised for cranioplasty, with their own benefits and limitations. Titanium cranioplasty is one of the well-established and widely used techniques, with most centres utilising computer-assisted reconstruction for manufacture of titanium plates. In this paper we present a novel method for making titanium cranioplasty plates using the craniectomy bone flap as a template and the results of our experience. To date we have performed 51 cranioplasties using this method. The surgical results have been comparable to those obtained using the computer-assisted model technique. The construction cost for titanium cranioplasty plates using this method has been ￡360 cheaper per plate compared with the computer-assisted method. In addition, the CT workload and radiation exposure have been reduced.     

Vascularized medial femoral condyle corticoperiosteal flaps for the treatment of recalcitrant humeral nonunions

Background: Several methods have been used in the management of humeral nonunions. With the advent of modern microsurgical techniques, vascularized bone grafting is becoming increasingly used to improve local biology. We report our experience in the use of a vascularized corticoperiosteal bone flap from the medial femoral supracondylar region in the treatment of recalcitrant humeral nonunions. Methods: A retrospective review was performed of all patients treated with this technique over a 4‐year period within our institution. Patient demographics, nonunion characteristics, complications, and long‐term outcomes were analyzed. Results: Six patients underwent vascularized periosteal graft reconstruction. Prior to this, all had failed an average of three procedures with the length of nonunion ranging from 6 to 68 months. All six nonunions healed by an average of 6.8 months (range 2–12 months). Two patients required additional secondary procedures. Functional outcome improved in all patients as adjudged by disabilities of the arm, shoulder, and hand, Mayo elbow performance, and Constant Murley scores. Conclusions: The vascularized medial femoral condyle corticoperiosteal flap provides an additional treatment option for the management of humeral nonunions. © 2011 Wiley‐Liss, Inc. Microsurgery, 2011.     

Relevance of ICP and ptiO2 for indication and timing of decompressive craniectomy in patients with malignant brain edema

BACKGROUND: The exact effects of decompressive craniectomy on intracranial pressure (ICP) and cerebral tissue oxygenation (ptiO2) are still unclear. Therefore, we have monitored ICP and ptiO2 intra-operatively and correlated these values to different operative steps during craniectomy. METHODS: ICP and ptiO2 values have been monitored both, simultaneously and continuously, in 15 patients with cerebral edema due to posttraumatic or postischemic brain swelling. Indications for craniectomy were an increase in ICP above 25 mmHg or a decrease in ptiO2 below 10 mmHg resistant to conservative treatment (e.g. mannitol, hyperventilation, adequate arterial blood oxygenation, etc.). In all cases, we performed a fronto-temporo-parietal craniectomy (15 x 12 cm) and dura enlargement with galea-periosteum. During craniectomy, monitoring of ICP and ptiO2 in the affected hemisphere was continued. Values were recorded and correlated with the different operative steps. FINDINGS: We performed craniectomy according to our treatment protocol in 5 patients. Prior to surgery, mean ICP values were 25.6 mmHg (range: 23-29 mmHg), mean ptiO2 values were 5.9 mmHg (range: 2.4-9.5 mmHg), and mean CPP values were 66 mmHg (range: 60-70 mmHg). After removing the bone flap, ICP values dropped to physiological values (mean: 7.4 mmHg), whereas ptiO2 values increased only slightly (mean: 11 mmHg). Opening of the dura resulted in a further decrease of ICP (mean 4.8 mmHg) and an increase of ptiO2 to normal limits (mean: 18.8 mmHg). After skin closure, mean ICP was 6.8 mmHg and mean ptiO2 was 21.7 mmHg, respectively. We found a significant decrease of ICP after craniectomy (p<0.042) and after dura enlargement (p<0.039) as well as a statistically significant increase in ptiO2 after craniectomy (p<0.043) and after dura enlargement (p<0.041). CONCLUSION: As a large bone flap in decompressive craniectomy is essential for adequate ICP reduction, the results of the presented cases suggest that dura enlargement is the crucial step to restore adequate brain tissue oxygenation and that ptiO2 monitoring could be an important tool for timing craniectomy in the future.