Importance of Early Cranioplasty in Reversing the "Syndrome of the Trephine/Motor Trephine Syndrome/Sinking Skin Flap Syndrome"

Outcome of Early Cranioplasty in Trephine Syndrome or Paradoxical Brain Herniation: A Case Report and Literature Review

Sinking skin flap syndrome (SSFS) is a rare complication observed in patients after craniectomy. The intracranial pressure is decreased after craniectomy, resulting in some conditions. These include mental change, focal deficits, headache, seizures, and dysautonomia. Cranioplasty is the most commonly used treatment method for SSFS. Here, the case of a patient is presented with symptoms, including sudden loss of consciousness, aphasia, and right-side weakness. A computed tomography (CT) scan revealed hemorrhagic conversion of parietotemporal infarct with midline shift. A decompressive craniectomy was performed, and the patient developed SSFS later. Subsequently, the patient underwent cranioplasty and showed improvements in neurological deficits. SSFS is rare; only a few cases have been reported in the literature.

Paradoxical brain herniation following decompressive craniectomy: A case series and systematic review of literature

INTRODUCTION

Paradoxical brain herniation (PBH) represents a rare and potentially life-threatening complication observed in individuals following decompressive craniectomy. Its diagnosis necessitates a high level of suspicion, combined with clinical and imaging evidence, such as midline shift, herniation, and a decreased Glasgow Coma Scale (GCS). Given the rarity and severity of this condition, we conduct a comprehensive literature review to identify all documented predisposing factors, clinical presentations, and appropriate clinical management. This review will serve as a guide for effective treatment strategies.

CASE PRESENTATION

In this report, we document three cases of post-traumatic PBH following decompressive craniectomy. The patient's predisposing factor was a lumbar puncture, with two cases resolving after Terendlenburg repositioning, hydration, and elective cranioplasty. The third case developed PBH after external ventricular drainage (EVD) insertion. Although the patient's GCS improved after clamping the EVD and hydration, the patient ultimately succumbed to meningitis.

CLINICAL DISCUSSION

The primary clinical manifestations of PBH often encompass a diminished GCS alongside radiographic evidence of midline shift and brain herniation. Various precipitating factors have been associated with PBH after decompressive craniectomy, including CSF drainage, dehydration, and upright positioning, although instances of spontaneous PBH have been documented. Reported therapeutic strategies encompass rehydration, Trendelenburg positioning, temporary cessation of CSF drainage, and cranioplasty.

CONCLUSION

Given the infrequency of PBH and the potential for misdiagnosis with brain edema, it is imperative to consider this condition in every patient who experiences a decreased level of consciousness following decompressive craniectomy.

Consensus on the prevention and repair of titanium mesh exposed wound after cranioplasty (2024 edition)

Titanium mesh exposure after cranioplasty is the most serious complication of this procedure. Although some clinical experience has been gradually accumulated over the years in the diagnosis and treatment of titanium mesh exposure, the treatment is often not standardized and it is difficult to achieve satisfactory repair results due to insufficient understanding of its pathogenesis and concurrent infections. To normalize the diagnosis and treatment of titanium mesh exposed wounds after cranioplasty and improve the therapeutic effect and the quality of life of patients, the Wound Repair Professional Committee of Chinese Medical Doctor Association organized an expert discussion based on the literature and current diagnosis and treatment status of titanium mesh exposed wounds after cranioplasty at home and abroad, and reached a consensus on the pathogenesis, preventive measures, and diagnosis and treatment strategies of titanium mesh exposed wounds after cranioplasty to provide reference for relevant clinicians.

Paradoxical Brain Herniation: An Unexpected Diagnosis

Paradoxical herniation is a dreadful neurosurgical complication often underdiagnosed, which typically becomes evident over the course of weeks to months after the initial intervention. Here we present a unique case with manifestations in the post-operative period. A patient initially referred to neurosurgery for a meningioma underwent an uneventful surgical excision, followed by the transient placement of a lumbar drain for 48 hours. On the first post-operative day, the patient exhibited progressively altered neurological status, with corresponding imaging revealing a transfalcine herniation, necessitating emergent decompressive craniectomy. Despite the medical and surgical interventions, there were continuous signs of neurological and imaging worsening, with increase in herniation, which led to the diagnosis suspicion of a paradoxical brain herniation. Consequently, a rapid reversal of neurological deficits was observed after applying maneuvers to augment the intracranial pressure, followed by cranioplasty. This case illustrates the utmost importance of clinical suspicion for the uncommon complications of neurointerventions.

Improved rehabilitation efficiency after cranioplasty in patients with sunken skin flap syndrome: a case series

PURPOSE

Sunken Skin Flap Syndrome (SSFS) is an uncommon, delayed complication after craniectomy characterized by a functional plateau or decline with variable neurologic symptoms, improving after cranioplasty. SSFS negatively impacts the rehabilitation course, with subjective reports of functional improvement after cranioplasty. However, no studies have assessed the impact of cranioplasty on functional recovery rate. This case series aims to analyze SSFS manifestations and management while awaiting cranioplasty. Also, to assess the role of cranioplasty on rehabilitation outcomes and recovery rate in SSFS patients.

METHODS

Four patients were identified with SSFS in inpatient rehabilitation. Each patient had unique clinical manifestations, with multiple strategies used for symptomatic control. Patients spent an average of 23 days in rehabilitation with SSFS symptoms before cranioplasty. After cranioplasty, all patients had SSFS symptom resolution. Comparing change in functional independence measure (FIM) scores and FIM efficiency pre-and post-cranioplasty rehabilitation course, a mean improvement of 23 and 0.72 occurred after cranioplasty, respectively.

CONCLUSION

A diagnosis of SSFS should be considered in craniectomy patients exhibiting functional decline or plateau with associated neurological symptoms. This study suggests that FIM and FIM efficiency increases in SSFS patients after cranioplasty, supporting prompt cranioplasty to improve functional outcomes and minimize rehabilitation delays.

Low-Cost 3-D-Printer-Assisted Personalized Cranioplasty Treatment: A Case Series of 14 Consecutive Patients

OBJECTIVE

The current study used polylactic acid molds [developed locally using three-dimensional printers and our software] and polymethyl methacrylate (PMMA) to perform cranioplasty of bone defects in technically demanding areas of the skull while ensuring ideal cosmetic results and functional recovery. The overall aim was to identify the ideal method for standard cranioplasty procedures METHODS: Polylactic acid duplicates of the skull defects were created for eligible patients, after which a two-part negative mold composed of plaster and silicone was used to form artificial bone with PMMA. Thereafter, cranioplasty was performed and the treatment success was assessed by evaluating the percentage of similarity objectively and the body image scale subjectively.

RESULTS

No surgical complications were seen to occur in the 14 patients included in the current study. Furthermore, the subjective and objective evaluation revealed a significant improvement in outcomes (p < 0.05). No postoperative complications were observed over a follow-up period of 6 months, except in 1 patient who exhibited late infection.

CONCLUSIONS

Cranioplasty operations were performed at an economical price of approximately US$50 dollars, suggesting that this method can be applied widely. Furthermore, preoperative preparation of the PMMA models can help reduce the duration of anesthesia and surgery which, in turn, will minimize the risk of surgical complications. Based on current knowledge in the field, we believe that this method represents the ideal technique.

Can we do better at measuring patient-reported outcomes after cranioplasty? A systematic review

Measuring quality of life (QOL) after cranioplasty is increasingly evident as a necessary component of patient-centered care. For data to be useful in clinical decision-making and approval of new therapies, studies must utilize valid and reliable instruments. Our objective was to critically appraise studies evaluating QOL in adult cranioplasty patients and determine validity and relevance of the patient-reported outcome measures (PROMs) used. Electronic databases of PubMed, Embase, CINAHL, and PsychINFO were used to identify PROMs measuring QOL in adult patients with cranioplasty. The methodological approach, cranioplasty outcomes, and domains measured by the PROMs were extracted and summarized descriptively. A content analysis of the identified PROMs was completed to identify the concepts measured. From 2236 articles identified, 17 articles containing eight QOL PROMs met the inclusion criteria. None of the PROMs was specifically validated or developed for adults undergoing cranioplasty. The QOL domains included physical health, psychological health, social health, and general QOL. These four domains encompassed 216 total items among the PROMs. Appearance was only assessed in two PROMs. To our knowledge, there are currently no validated PROMs that comprehensively measure appearance, facial function, and adverse effects in adults undergoing cranioplasty. There is an urgent need to develop PROMs to measure QOL outcomes rigorously and comprehensively in this patient population to inform clinical care, research, and quality improvement initiatives. Findings from this systematic review will be used to derive an outcome instrument containing important concepts related to QOL in patients who undergo cranioplasty.

Predictors of Clinical Outcomes in Autologous Cranioplasty

BACKGROUND

Cranioplasty is a common neurosurgical procedure and autologous grafts are preferred due to their aesthetic and biocompatibility benefits. Multiple risk factors are implicated as predictors for neurologic outcome. This study focuses on risk factors that may be associated with complications and analyzes the predictors of neurologic outcomes after autologous cranioplasty.

METHODS

This is a retrospective observational study conducted at a tertiary care center between 2015 and 2021. Adults with autologous cranioplasty (n = 132) were recruited from procedure logs and the hospital electronic health record. Clinicodemographic parameters, risk factors, and complications were recorded. Neurologic outcomes were measured using the dichotomized Glasgow Outcome Scale (GOS). Primary outcome measure was pre- and post-cranioplasty GOS at the last follow up. Secondary outcome measures were the predicting factors that contributed to enhanced neurologic outcome post-cranioplasty.

RESULTS

Mean age was 41.4 (standard deviation ± 13.5) years with male predominance (12.2:1). Complications developed in 12.9% (n = 17), with infections in 3.8% (n = 5) and hydrocephalus in 2.3% (n = 3). In bivariate analysis, pre-cranioplasty GOS good grades 4 and 5 (P < 0.001), trauma as an indication for decompressive craniectomy (DC) (P < 0.001), and early cranioplasty ≤12 weeks (P = 0.023) were statistically significant predictors for post-cranioplasty neurologic recovery at follow-up. In a multiple logistic regression model, adjusted odds ratio for pre-cranioplasty GOS was 28.77 (95% confidence interval [CI] 7.21-114.74, P < 0.001), for trauma as indication for DC was 5.15 (95% CI 1.65-16.05, P = 0.003), and for early cranioplasty ≤12 weeks was 3.04 (95% CI 1.12-8.27 P = 0.029).

CONCLUSIONS

Autologous cranioplasty contributes to a quantifiable neurologic outcome. Pre-cranioplasty neurologic status, cranioplasty done for traumatic DC and early cranioplasty may have potential for enhanced neurologic recovery. Further clinical studies with better evidence may expound upon these findings.

Sinking skin syndrome in a decompressive craniectomy series: Clinical and radiological features

Background:

The sinking skin syndrome (SSS) is a particular complication after a decompressive craniectomy (DC). It still remains a poorly understood and underestimated entity.

Methods:

Retrospective case series of craniectomized patients with and without SSS. Clinical and radiological features (DC diameter, shape of craniectomy flap, and midline deviation) were described and relative volumes of intracranial loss were quantified.

Results:

Twenty-seven patients (63% with SSS). The most common indication for DC was traumatic brain injury: 48.15%. The p50 diameter of DC was 12.8 cm for patients with SSS and 11.1 cm for patients without (Z score = 0.32). DC area was 81.5 cm² for patients with SSS and 71.43 cm² for patients without the syndrome (Z score = 0.61). According to the shape of the craniectomy flap, we classified our patients as: «same level» (51.8%), «sunken» (25.9%), and «extracranial herniation» (14.8%). Two patients (7.4%) had paradoxical herniation. Midline deviation was present in 12 (70.6%) patients with SSS. The 3^rd ventricle volume average was 1.2 cc for patients with SSS versus 2.35 cc for patients without (Z score = 0.04). About 94.11% of patients (16 out of 17) clearly improved after replacement of the cranial defect.

Conclusion:

In our series, low 3^rd ventricle volumes had a good relation with SSS. The presence of a sunken flap does not guarantee SSS per se and we propose the following radiologic description: A = sunken, B = same level, C = extracranial herniation, and D = paradoxical. Replacement of the skull defect is the main treatment.

Current Concepts in Cranial Reconstruction: Review of Alloplastic Materials

Cranioplasty for acquired cranial defects can be complex and challenging. Benefits include improved cosmesis, protection of intracranial structures, and restoration of neurocognitive function. These defects can be reconstructed with preserved craniectomy bone flaps, split autografts, or alloplastic materials. When alloplastic cranioplasty is planned, the material should be carefully selected. There is confusion on which material should be used in certain scenarios, particularly in composite defects.

Paradoxical Brain Herniation after Cranioplasty: Secondary Sunken Flap Syndrome

Decompressive craniectomy is a life-saving procedure done for innumerable etiologies. Though, not a technically demanding procedure, it has its own complications. Among many, sinking flap syndrome or syndrome of the trephined or paradoxical herniation of brain is frequently underestimated. It results from the pressure difference between the atmospheric pressure and the intracranial pressure causing the brain to shift inward at the craniectomy site. This can present with either nonspecific symptoms leading to delay in diagnosis or acute neurological deterioration, memory disturbances, weakness, confusion, lethargy, and sometimes death if not treated. Cranioplasty is a time validated procedure used to treat paradoxical brain herniation with good and early neurological recovery. We, here in, are going to describe a case report in which the paradoxical herniation occurred after cranioplasty which has not been described in literature.

Therapeutic strategies for retention of cranioplasty titanium mesh after mesh exposure

BACKGROUND

Titanium mesh exposure after cranioplasty is a possible complication and is usually managed by mesh removal and flap transfer, but the advantages of the rigid prosthesis are then lost. This study aimed to present our experience with negative pressure wound therapy combined with soft tissue dilation for retaining the titanium mesh in patients with mesh exposure after cranioplasty.

METHODS

This retrospective study included patients treated between 01/2016 and 05/2019 at the Jiangyin Hospital Affiliated to Southeast University School of Medicine. The wound was cleaned, and a cystic space was created for the tissue dilator, which was used with a self-designed negative pressure dressing. After the target dilation was achieved, the repair was conducted while retaining the titanium mesh.

RESULTS

Eight patients were included (seven males and one female; 53.6 ± 8.8 (range, 43-65) years of age). The exposed mesh area ranged from 1 × 1 to 4 × 5.5 cm. The thinning scalp area around the exposed mesh ranged from 3.6 × 3.8 to 4 × 5.5 cm. Five patients had positive wound cultures and received sensitive antibiotics. The dilator embedding time was 20-28 days. The time of negative pressure wound therapy was 25-33 days. The hospital stay was 30-41 days. Primary wound healing was achieved in all eight patients. There were no signs of recurrence after 6-18 months of follow-up. The cranial CT scans were unremarkable.

CONCLUSIONS

Negative pressure wound therapy combined with soft tissue dilation for exposed titanium mesh after cranioplasty might help retain the titanium mesh.

Characteristics of Patients with Trephine Syndrome: A Retrospective Study

Objectives:

This study retrospectively investigated the prevalence and clinical features of trephine syndrome, which is a late complication of craniectom, in patients who underwent craniectomy decompression.

Methods:

Trephine syndrome was defined as an increase of ≥2 points in the functional independent measure (FIM) score at 7 days after cranioplasty compared with that 3 days before cranioplasty. Patients who underwent craniectomy at Kawasaki Medical School Hospital between January 1, 2010, and March 15, 2020, were included in the study.

Results:

During the observation period, 102 patients underwent craniectomy decompression; 71 of them later underwent cranioplasty. In total, 12 and 59 patients were assigned to the trephine and non-trephine syndrome groups, respectively. The patients in the trephine syndrome group were significantly younger than those in the non-trephine syndrome group (P<0.05). The mean durations±standard deviations (in days) from craniectomy decompression to cranioplasty were 57.1±38.9 and 83.6±69.3 for the trephine and non-trephine syndrome groups, respectively (P<0.05). Improvements in the FIM motor scores were greater than the improvements in the cognitive scores for all but one case (P<0.05). The frequency with which patients experienced exacerbation (worsened consciousness and sudden anisocoria) after hospitalization was significantly higher in the trephine syndrome group than in the non-trephine syndrome group (P<0.05).

Conclusions:

Performing cranioplasty as early as possible in young patients may lead to functional improvement. In the trephine syndrome group, the improvement in motor FIM score was greater than that of the cognitive score. Moreover, post-hospitalization exacerbation was more frequent in the trephine syndrome group.

[Features of modeling a polymer implant for closing a defect after decompressive craniotomy]

BACKGROUND

Individual polymer implants are widespread for bone reconstruction after decompressive craniectomy. Despite the availability of customized titanium products, various specialists and hospitals prefer polymer implants.

OBJECTIVE

To compare the methods of modeling and manufacturing the polymethylmethacrylate implants and identify the features affecting the quality of reconstruction.

MATERIAL AND METHODS

We analyzed 14 patients with extensive skull defects after installation of polymethyl methacrylate implants. Software used for modeling of individual implants by different specialists was compared.

RESULTS

Satisfactory reconstruction result was obtained in all cases. There were no infectious complications. The authors outlined certain important aspects for modeling of individual polymer products: local use of anatomical thickness of the implant, leaving safe spaces, prevention of temporal retraction, template-based resection before reconstruction.

CONCLUSION

To date, skull defect closure with polymeric materials remains relevant, and even has certain advantages over customized titanium products.

Trends and Outcomes of Cranioplasty Alone Versus Single-Stage Composite Scalp and Calvarial Reconstruction

BACKGROUND

Cranioplasty is a critical intervention to restore the calvarium using autologous or alloplastic materials with single-stage composite scalp and calvarial reconstruction reserved for complex cases. This study aims to identify 30-day outcomes in scalp and calvarial reconstruction using the American College of Surgeons National Surgical Quality Improvement Program database.

METHODS

The authors conducted a retrospective analysis of the 2010 to 2018 American College of Surgeons National Surgical Quality Improvement Program database. Adult patients who underwent cranioplasty were identified using current procedural terminology coding and included by exposure type (autologous, alloplastic, composite, or other). Subjects with missing exposure or outcome data were excluded. Primary outcome was 30-day reoperation, whereas secondary outcomes were 30-day unplanned readmission and transfusion. Univariate analysis was completed to assess differences in demographics, comorbidities, and postoperative complications. Multivariable logistic regression was used to control for confounders.

RESULTS

In total, 1719 patients underwent cranioplasty (mean age 54.7 ± 15.3 years, 43.5% male), including 169(9.8%) autologous, 1303(75.8%) alloplastic, 32(1.9%) composite, and 215(12.5%) other procedures. Cranioplasty procedures were associated with 30-day complication and mortality rate of 16.5% and 2.4%, respectively. Composite cranioplasty was associated with decreased 30-day reoperation (adjusted odds ratios 0.11, 95% confidence interval 0.014-0.94, P = 0.044). There was no statistically significant difference in readmission between cranioplasty groups. Alloplastic cranioplasty was associated with decreased odds of postoperative transfusion (adjusted odds ratios 0.47, 95% confidence interval 0.27-0.84, P = 0.01).

CONCLUSIONS

Cranioplasty is an increasingly common procedure. Alloplastic cranioplasty is associated with decreased 30-day transfusion requirement, whereas single-stage composite reconstruction is a viable option and associated with decreased 30-day reoperation with no difference in readmission.

Clinical improvement after cranioplasty and its relation to body position and cerebral hemodynamics

Cranioplasty after decompressive craniectomy (DC) has been found to improve the neurological condition. The underlying mechanisms are still unknown. The aim of this study is to investigate the roles of the postural changes and atmospheric pressure (AP) in the brain hemodynamics and their relationship with clinical improvement. Seventy-eight patients were studied before and 72 h after cranioplasty with cervical and transcranial color Doppler ultrasound (TCCS) in the sitting and supine positions. Craniectomy size, shape, and force exerted by the AP (torque) were calculated. Neurological condition was assessed with the National Institutes of Health Stroke Scale (NIHSS) and the Barthel index. Twenty-eight patients improved after cranioplasty. Their time elapsed from the DC was shorter (214 vs 324 days), preoperative Barthel was worse (54 vs 77), internal carotid artery (ICA) mean velocity of the defect side was lower while sitting (14.4 vs 20.9 cm/s), and torque over the craniectomy was greater (2480.3 vs 1464.3 N*cm). Multivariate binary logistic regression showed the consistency of these changes. TCCS findings were no longer present postoperatively. Lower ICA (defect side) velocity in the sitting position correlates significantly with clinical improvement. Greater torque exerted by the AP might explain different susceptibilities to postural changes, corrected by cranioplasty.

Improvement in neurological outcome and brain hemodynamics after late cranioplasty

BACKGROUND

Early cranioplasty has been encouraged after decompressive craniectomy (DC), aiming to reduce consequences of atmospheric pressure over the opened skull. However, this practice may not be often available in low-middle-income countries (LMICs). We evaluated clinical improvement, hemodynamic changes in each hemisphere, and the hemodynamic balance between hemispheres after late cranioplasty in a LMIC, as the institution's routine resources allowed.

METHODS

Prospective cohort study included patients with bone defects after DC evaluated with perfusion tomography (PCT) and transcranial Doppler (TCD) and performed neurological examinations with prognostic scales (mRS, MMSE, and Barthel Index) before and 6 months after surgery.

RESULTS

A final sample of 26 patients was analyzed. Satisfactory improvement of neurological outcome was observed, as well as significant improvement in the mRS (p = 0.005), MMSE (p < 0.001), and Barthel Index (p = 0.002). Outpatient waiting time for cranioplasty was 15.23 (SD 17.66) months. PCT showed a significant decrease in the mean transit time (MTT) and cerebral blood volume (CBV) only on the operated side. Although most previous studies have shown an increase in cerebral blood flow (CBF), we noticed a slight and nonsignificant decrease, despite a significant increase in the middle cerebral artery flow velocity in both hemispheres on TCD. There was a moderate correlation between the MTT and contralateral muscle strength (r =  - 0.4; p = 0.034), as well as between TCD and neurological outcomes ipsilateral (MMSE; r = 0.54, p = 0.03) and contralateral (MRS; p = 0.031, r =  - 0.48) to the operated side.

CONCLUSION

Even 1 year after DC, cranioplasty may improve cerebral perfusion and neurological outcomes and should be encouraged.

Syndrome of the Trephined and ParoxySmal Sympathetic Hyperactivity in a 17-year-old minimally conscious state patient: A Case Report

Purpose: Syndrome of the Trephined (SoT) is one of the most unknown complications of the Decompressive Craniectomy (DC) after Traumatic Brain Injury (TBI). A combination of neurological clinical criteria and radiological signs after DC is necessary to make its diagnosis. In our case, as the patient was in a minimally conscious state (MCS), it was impossible to clinically assess any neurological deterioration according to the criteria found in the literature. There is no description of clinical diagnostic criteria suitable for patients with MCS apart from the visible 'Skin Flap.'Method: A 17-year-old patient sustained a severe TBI. Two months after the TBI and a DC he exhibited an MCS with a Glasgow Coma Scale (GCS) of 7 and a Wessex Head Injury Matrix (WHIM) of 5. He presented several paroxysmal sympathetic hyperactivity (PSH) episodes a day and developed a sinking skin flap. A cranioplasty was performed. Then, we noticed the gradual disappearance of PSH episodes plus an improvement of the CRS and the WHIM. Results: The evolution of the WHIM data revealed a statistically significant difference (p 0.0047). Conclusion: Further studies should be conducted to assess whether the WHIM and the frequency of PSH episodes may be part of the diagnostic criteria for SoT in MCS patients.

Cranioplasty

Calvarial defects are commonly encountered after neurosurgical procedures, trauma, and ablative procedures of advanced head neck cancers. The goals of cranioplasty are to provide a protective barrier for the intracranial contents, to restore form, and prevent syndrome of the trephined. Autologous and alloplastic techniques are available, each with their advantages and drawbacks. A multitude of materials are available for cranioplasty, and proper timing of reconstruction with attention to the overlying skin envelope is important in minimizing complications.

A New Type of Three-Dimensional Customized Composite Implant in Reconstruction of Large Skull Defects

ABSTRACT

Large skull defects can result in chronic injury to intracranial tissues as well as psychological trauma for patients, and their repair presents a challenge to surgeons. Hydroxyapatite has been used in reconstructing skull defects for many years, but it is difficult to adjust the shape and size of the material intraoperatively, especially for large defects. With three-dimensional digital technology, a new type of customized composite implant made of epoxide acrylate maleic and hydroxyapatite has been applied in clinical practice. In this retrospective review, 15 patients with large skull defects (4 female and 11 male, at a mean age of 36.4 years, range from 24-65 years) were treated with the novel customized composite implant, reconstructing the large skull defects successfully. During the average 2.2 years follow-up period (range 0.5-4 years), complications including infection, cerebrospinal fluid leakage, intracranial hemorrhage, or implant exposurea were not occured, only 1 patient (6.7%) with a seroma managed non-operatively. The customized implants, which required no intraoperative adjustments and are about a third of the cost of titanium implants, are an excellent alternative for large skull defect repair.

Sinking Skin Flap Syndrome following Posttraumatic Hydrocephalus

Introduction

Complications following craniotomy are not uncommon and Sinking Skin Flap Syndrome (SSFS) constitutes a rare entity that may present after a large Decompressive Craniectomy. Although the entity is widely reported, the literature mostly consists of case reports. Authors present a case series of three patients with review of literature highlighting the various factors which can prove therapeutic and can help in avoidance of complications.

Materials and Methods

The study was conducted over a period of 3 years, from 2016 to 2019, and included 212 patients who underwent unilateral Decompressive Craniectomy (DC) for trauma in our institute. All 212 patients underwent a similar DC following a strict institutional protocol and the craniectomies were performed by the same surgical team. At total of 160 patients survived and elective cranioplasty was planned at a 3-month interval. Out of a total of 160 patients who survived, 38 developed hydrocephalus, 3 patients presented with hydrocephalus acutely and had to be shunted before cranioplasty and underwent ventriculoperitoneal (VP) shunting on the opposite side of craniectomy. All 3 of these patients developed SSFS and were the focus of this case series wherein review of literature was done with emphasis being laid on the salient features towards management of SSFS in such precranioplasty shunted patients. These 3 patients were treated via rehydration using normal saline (NS) till the Central Venous Pressure (CVP) equaled 8-10 cm of water, nursing in Trendelenburg position and shunt occlusion using silk 3-0 round bodied suture tied over a "C"-loop of VP shunt tube over clavicle. This was followed by cranioplasty within 2 days of presentation using a flattened, nonconvex artificial Polymethyl Methacrylate (PMMA) bone flap with central hitch suture taken across the bone flap and release of shunt tie in immediate postoperative period. The PMMA bone flap was made intraoperatively after measuring the defect size accurately after exposure of defect. 3D printing option was not availed by any patient considering the high cost and patients' poor socioeconomic status.

Results

Out of a total of 212 patients, thirty-eight patients (19%) developed posttraumatic hydrocephalus and out of 38, three presented with SSFS over the course of time. Two patients presented with hemiparesis of the side opposite to sunken flap while 1 other patient was brought by relatives in stuporous state. All 3 were subjected to VP shunt tie, rehydration, and cranioplasty using flattened artificial bone flap and showed gradual recovery in postoperative period without any complications.

Conclusion

Various factors like nursing in Trendelenburg position, adequate rehydration, early cranioplasty after resolution of oedema, preoperative tying of VP shunt and its subsequent release in immediate postoperative period, use of flattened PMMA bone flaps, placement of a central dural hitch suture across the bone, and a preoperative central burr hole in the bone flap may accelerate healing and, in most cases, reversal of sensory-motor deficits along with reduction in complication rates.

A Customized Technique of Cranioplasty for Patients with Large Skull Defects: A Technical Note

OBJECTIVE

In our technical note, we have presented a technique of cranioplasty for large skull defects.

METHODS

A thin-slice computed tomography scan is performed. A model of the skull is constructed using a desktop 3-dimensional printer from the computed tomography scan. The skull model is filled with towels of soft cotton and inserted in a sterile thin plastic bag. The implant is molded intraoperatively on the skull model under sterile conditions. After surgical exposure of the skull defect, the implant is inserted and fixed using miniplates and miniscrews. The technique was used in 6 patients and described in 2 representative cases.

RESULTS

The required time and cost are significantly lower than those for other techniques used for preoperative manufacture of implants. No technique-related complications occurred. The radiological and cosmetic results were satisfactory. In the present case series, no early or delayed complications occurred.

CONCLUSION

The presented technique is simple, safe, and time- and cost-effective. The technique and results are reproducible.

[Syndrome of the trephined]

Syndrome of the trephined (SoT) is the neurological deterioration that occurs after the performance of decompressive craniectomy in which bone is not replaced. The incidence of SoT varies, but this entity seems to be underdiagnosed. It is characterized by symptom reversal after bone replacement, which is the only definitive treatment. We report the case of a patient assessed by the Rehabilitation Service in the Critical Care Unit after a stroke, who had altered level of consciousness and abrupt motor impairment. The patient was diagnosed with SoT. Rehabilitation, with early postural changes, helped to ameliorate the symptoms until the provision of definitive treatment.

Unrepaired decompressive craniectomy worsens motor performance in a rat traumatic brain injury model

Decompressive craniectomy (DC) is often required to manage rising intracranial pressure after traumatic brain injury (TBI). Syndrome of the trephine (SoT) is a reversible neurologic condition that often occurs following DC as a result of the unrepaired skull. The purpose of the present study is to characterize neurological impairment following TBI in rats with an unrepaired craniectomy versus rats with a closed cranium. Long Evans male rats received a controlled cortical impact (CCI) over the caudal forelimb area (CFA) of the motor cortex. Immediately after CCI, rats received either a hemi-craniectomy (TBI Open Skull Group) or an immediate acrylic cranioplasty restoring cranial anatomy (TBI Closed Skull Group). Motor performance was assessed on a skilled reaching task on post-CCI weeks 1—4, 8, 12, and 16. Three weeks after the CCI injury, the TBI Closed Skull Group demonstrated improved motor performance compared to TBI Open Skull Group. The TBI Closed Skull Group continued to perform better than the TBI Open Skull Group throughout weeks 4, 8, 12 and 16. The protracted recovery of CFA motor performance demonstrated in rats with unrepaired skulls following TBI suggests this model may be beneficial for testing new therapeutic approaches to prevent SoT.

Postural neurologic deficits after decompressive craniectomy: A case series of sinking skin flap syndrome in traumatic brain injury

BACKGROUND

Hemicraniectomy to manage raised intracranial pressure following traumatic brain injury (TBI) has improved survival but may increase the incidence of Sinking Skin Flap Syndrome (SSFS). SSFS is a clinical syndrome in which patients with craniectomy develop objective neurologic abnormalities due to the pressure of the atmosphere on the unprotected brain, often presenting with postural headaches and neurologic deficits that localize to the craniectomy site. Previously thought to be a rare complication of craniectomy after TBI, evidence suggests SSFS is under-recognized.

OBJECTIVE

To describe the clinical and radiographic features leading to diagnosis and the impact of temporizing and definitive management of SSFS on outcomes in inpatients with moderate/severe TBI.

METHODS

Two patients' symptoms, qualitative behaviour observation, physical and cognitive outcome measures, and neuroimaging pre- and post-temporizing measures and cranioplasty are presented.

RESULTS

Both patients demonstrated partial improvements with temporizing measures and substantial improvements in functional, cognitive, physical, and rehabilitation outcomes from the cranioplasty and resolution of SSFS.

CONCLUSIONS

Rehabilitation care providers are critical to the timely diagnosis and management of SSFS, including the use of temporizing measures and advocacy for definitive treatment with cranioplasty. These cases highlight the diverse clinical presentations and importance of SSFS diagnosis to improve patient outcomes.

Cranioplasty: A Comprehensive Review of the History, Materials, Surgical Aspects, and Complications

Cranioplasty is a common neurosurgical procedure performed to reconstruct cranial defects. The materials used to replace bone defects have evolved throughout history. Cranioplasty materials can be broadly divided into biological and synthetic materials. Biological materials can be further subdivided into autologous grafts, allografts, and xenografts. Allografts (bony materials and cartilage from cadavers) and xenografts (bony materials from animals) are out of favor for use in cranioplasty because of their high rates of infection, resorption, and rejection. In autologous cranioplasty, either the cranial bone itself or bones from other parts of the body of the patient are used. Synthetic bone grafts have reduced the operation time and led to better cosmetic results because of the advancement of computer-based customization and three-dimensional printing. Aluminum was the first synthetic bone graft material used, but it was found to irritate neural tissue, induce seizures, and dissolve over time. Acrylic, in the form of methyl methacrylate, is the most widely used material in cranioplasty. Hydroxyapatite is a natural component of bone and is believed to enhance bone repair, resulting in decreased tissue reactions and promoting good osteointegration. Polyetheretherketones are light and nonconductive and do not interfere with imaging modalities. The complication rates of cranioplasty are high, and surgical site infection is the most common complication. The effect of cranioplasty timing on cognitive function remains debatable. However, the timing of cranioplasty is independent of neurologic outcomes. In this article, the history, materials, complications, and evolution of current practices used in cranioplasty are comprehensively reviewed.

Handmade Cranioplasty: An Obsolete Procedure or a Surgery That Is Still Useful?

Custom made cranioplasty (CM CPL) represents the gold standard for cranial defect reconstruction, allowing an adequate protection of the brain with good cosmetic results. Nevertheless, it is an expensive procedure, requiring time for preparation of the prothesis. Aim of this study is to evaluate whether and in what cases handmade cranioplasty (HM CPL) still represents a valid alternative to CM CPL.Therefore, all consecutive cranioplasties in our center from 2013 to 2019 have been analyzed. Size and location of cranial defect have been considered, as the cause of decompression. Morbidity rate and final outcome have been evaluated. Series includes 143 patients (61% males, mean age: 60 years, SD:16). HM CPL was performed in 59 cases (41.2%) and CM in the remaining 84 (58.8%). HM CPL was preferred for smaller cranial defects (p: 0.22), inferior to 100 cm (p: 0.01) located in fronto-parietal-occipital area (p: 0.01). Furthermore, HM CPL results in the first choice after removal of infiltrative tumors (p: 0.02). Surgical complications consisted in 14 (9%) infections, 8 hematomas (5.6%), and one cranioplasty displacement (0.7%). At follow-up, in 85.3% of cases the CPL is still in place with satisfactory cosmetic and functional outcome (86.5% of HM CPL, 84.5% of CM CPL).HM CPL may still represent an effective and economic alternative procedure, when specific patient selection criteria are respected. This technique requires a long learning learning curve and demanding surgical maneuvers. Our handmade reconstruction technique with some hints to improve the esthetic result is presented.

Postoperative Imaging of Complications Following Cranial Implants

A wide range of neurosurgical implants, cranioplasty materials and catheters have been developed to treat a variety of intracranial disorders. Interpretation of postoperative imaging can be challenging and confounded by postoperative changes and implant-related complications. Review of recent literature suggested that there is a paucity of data on postoperative cranial implant-related complications.

If not addressed appropriately in a timely manner, these complications may cause a delay in the patient’s treatment with subsequent prolongation of hospital stay. It is therefore paramount for clinicians and radiologists to be aware of the appearance of these implant-related complications on imaging during postoperative surveillance.

Sinking Skin Flap Syndrome and Paradoxical Herniation Provoked by a Malfunction of External Lumbar Drainage and CSF Leak

The sinking skin flap syndrome represents a less-frequent complication in patients after a decompressive craniectomy. It is defined as a neurological deterioration accompanied by a flat or concave deformity of the craniectomy-related skin flap. The underlying brain parenchyma is distorted correspondingly with its blood flow and metabolism being impaired and cerebrospinal fluid hydrodynamics being disturbed, thus causing cerebral dysfunction and neurological symptomatology. The most important options for reversal of this syndrome include Trendelenburg position, maintaining of the cerebrospinal fluid balance, and cranioplasty as a definite solution. We present a patient who underwent a decompressive craniectomy complicated by a cerebrospinal fluid leak in the operative wound treated by means of an external lumbar drainage. Subsequently he developed the sinking skin flap syndrome and a paradoxical cerebral herniation after the drainage system malfunction with a massive cerebrospinal fluid leak at the site of the lumbar drain insertion parallel to the drain itself. His symptoms were, however, successfully alleviated by a positional change, rehydration, and interruption of the lumbar drainage. This illustrational case suggests that clinicians should be aware that patients after decompressive craniectomy may develop a sinking skin flap syndrome as it may either represent an acute risk of a paradoxical brain herniation or complicate the further postoperative care if developed in a chronic way.

Split Calvarial Grafting for Closure of Large Cranial Defects: The Ideal Option?

Among the various cranioplasty options for reconstruction of large post-craniectomy defects, split calvarial grafting offers numerous significant advantages such as the provision of viable autogenous bone graft material comprising of living, immunocompatible bony cells that integrate fully with the skull bone bordering the cranial defect. Its potential for revascularization and subsequent integration and consolidation allows its successful use even in previously infected or otherwise compromised recipient sites. Its excellent contour match at the recipient site and low cost as compared to various alloplastic implant materials often makes it preferable to the latter. Surgeon's skill, dexterity, expertise and experience are important factors to be considered in this highly technique-sensitive procedure.

Subtotal calvarial vault reconstruction utilizing a customized polyetheretherketone (PEEK) implant with chimeric microvascular soft tissue coverage in a patient with syndrome of the trephined: A case report

The syndrome of the trephined is a neurologic phenomenon that manifests as sudden decline in cognition, behavior, and sensorimotor function due to loss of intracranial domain. This scenario typically occurs in the setting of large craniectomy defects, resulting from trauma, infection, and/or oncologic extirpation. Cranioplasty has been shown to reverse these symptoms by normalizing cerebral hemodynamics and metabolism. However, successful reconstruction may be difficult in patients with complex and/or hostile calvarial defects. We present the case of a 48-year-old male with a large cranial bone defect, who failed autologous cranioplasty secondary to infection, and developed rapid neurologic deterioration leading to a near-vegetative state. Following debridement and antibiotic therapy, delayed cranioplasty was accomplished using a polyetheretherketone (PEEK) implant with free chimeric latissimus dorsi/serratus anterior myocutaneous flap transfer for vascularized resurfacing. Significant improvements in cognition and motor skill were noted in the early postoperative period. At 6-month follow-up, the patient had regained the ability to speak, ambulate and self-feed—correlating with evidence of cerebral/ventricular re-expansion on computed tomography. Based on our findings, we advocate delayed alloplastic implantation with total vascularized soft tissue coverage as a viable alternative for reconstructing extensive, hostile calvarial defects in patients with the syndrome of the trephined.

Cranial Vault Defects and Deformities Resulting from Combat-Related Gunshot, Blast and Splinter Injuries: How Best to Deal with Them

Combat-related gunshot and blast injuries of the craniomaxillofacial region present a unique and challenging situation for the maxillofacial and reconstructive surgeon. The devastating cosmetic deformities and severe functional debility ensuing as a result of extensive hard and soft tissue disruption caused by these highly complex injuries, can have disastrous consequences, unless managed in a swift and efficient manner, by a multidisciplinary team approach. Large calvarial defects and deformities are frequent sequelae of these injuries and could result from shattering of the cranial vault by the force of an exploding shell, mine or improvised explosive device, or due to penetration of the skull by the projectile, such as a bullet, flying splinters or shrapnel. It could also result from the decompressive craniectomy carried out in these patients as a neurosurgical procedure to deal with the traumatic brain injury sustained. Management of such injuries is significantly different from that of other craniomaxillofacial injuries, owing to the quantum and severity of hard and soft tissue destruction encountered in the former and also the need to deal with aspects such as splinters from the projectile deeply embedded within vital structures such as the delicate brain tissue and meninges. Further, restoration of the lost structural and functional integrity of the cranial vault using the most suitable cranioplasty material, is imperative to provide protection to the vulnerable and vital cranial contents. Correction of the cranial deformity is also essential from an esthetic and psychosocial standpoint, to restore the morale of the patient. The present study elaborates the immediate/primary management as well as the secondary/definitive management of blast and ballistic head injury patients. Comprehensive treatment and rehabilitation of these patients, including reconstruction of extensive calvarial defects and deformities, resulting either directly or indirectly from combat injuries, have been described in detail. This study also aims to analyze, review and reassess the currently accepted management perspectives and treatment protocols of combat-related cranial injuries and proposes a useful algorithm to best manage them.

Titanium mesh cranioplasty in pediatric patients after decompressive craniectomy: Appropriate timing for pre-schoolers and early school age children

PURPOSE

There is little knowledge on the growth of cranial defects, appropriate timing and outcomes of application of titanium mesh for cranioplasty in the pediatric population, especially pre-school age (2-5 years old) and school age (6-12 years old) children. We hypothesised that cranioplasty for pre-schoolers could be delayed to school age due to the expected cranium growth, whereas, for the school age group, it is better to perform routine cranioplasty (3-6 months) to protect the brain and therefore ensure their timely return to school life.

MATERIALS AND METHODS

A retrospective review of pediatric patients (2-12 years old) who underwent titanium mesh cranioplasty for cranial defects from 2006 to 2012 was performed. Patient demographic data, radiological data, and clinical information were collected. Specifically, cranial defect sizes were evaluated by three-dimensional (3D) reconstruction of computed tomography data after craniectomy, before cranioplasty and 2-years after cranioplasty. Patients were routinely followed up at an outpatient clinic for complications and school attendance.

RESULTS

A total of 18 titanium mesh cranioplasties were performed in 18 patients. The average interval between craniectomy and cranioplasty was 3 years for pre-schoolers and 4 months for the school age group. Patients in the pre-schooler group showed significant enlargements in cranial defects during the interval as compared with the school age group (26% vs. 4%, P < 0.05). There were no surgery-related complications except in one patient, who had titanium mesh exposure 11 months later. Two years after cranioplasty, there was no significant difference in mild cranial defect enlargements between the two groups (11% vs. 6%, P > 0.05). Patients were followed for an average of 5 (range, 2-8) years. All patients had satisfactory recovery of cranial contour, sufficient protection of the brain and active participation in school study. All patients had satisfactory recovery of cranial contour, sufficient protection of the brain and active participation in school.

CONCLUSION

Timing of titanium mesh cranioplasty after decompressive craniectomy based on their age is a workable solution for school-age pediatric patients. The enlargement of cranium defects in pre-schoolers supports a delayed repair until school age. The long-term outcomes for these patients with titanium mesh cranioplasty are favourable.

Sinking Skin Flap Syndrome or Syndrome of the Trephined: A Report of Two Cases

Decompressive craniectomy (DC) is commonly performed in patients with intracranial hypertension or brain edema due to traumatic brain injury. Infrequently, neurologic deteriorations accompanied by sunken scalp may occur after DC. We report two patients with traumatic subdural hemorrhage who had neurologic deteriorations accompanied by sunken scalp after DC. Neurologic function improved dramatically in both patients after cranioplasty. Monitoring for neurologic deterioration after craniectomy is advised. For patients showing neurologic deficit with a sunken scalp, early cranioplasty should be considered.

Timing for cranioplasty to improve neurological outcome: A systematic review

INTRODUCTION

Cranioplasty is a surgical technique applied for the reconstruction of the skullcap removed during decompressive craniectomy (DC). Cranioplasty improves rehabilitation from a motor and cognitive perspective. However, it may increase the possibility of postoperative complications, such as seizures and infections. Timing of cranioplasty is therefore crucial even though literature is controversial. In this study, we compared motor and cognitive effects of early cranioplasty after DC and assess the optimal timing to perform it.

METHODS

A literature research was conducted in PubMed, Web of Science, and Cochrane Library databases. We selected studies including at least one of the following test: Mini-Mental State Examination, Rey Auditory Verbal Learning Test immediate and 30-min delayed recall, Digit Span Test, Glasgow Coma Scale, Glasgow Outcome Scale, Coma Recovery Scale-Revised, Level of Cognitive Functioning Scale, Functional Independence Measure, and Barthel Index.

RESULTS

Six articles and two systematic reviews were included in the present study. Analysis of changes in pre- and postcranioplasty scores showed that an early procedure (within 90 days from decompressive craniectomy) is more effective in improving motor functions (standardized mean difference [SMD] = 0.51 [0.05; 0.97], p-value = 0.03), whereas an early procedure did not significantly improve neither MMSE score (SMD = 0.06 [-0.49; 0.61], p-value = 0.83) nor memory functions (SMD = -0.63 [-0.97; -0.28], p-value < 0.001). No statistical significance emerged when we compared studies according to the timing from DC.

CONCLUSIONS

It is believed that cranioplasty performed from 3 to 6 months after DC may significantly improve both motor and cognitive recovery.

Immediate Cranioplasty for Postcranioplasty Infection in Patients with Ventriculoperitoneal Shunt

BACKGROUND

Patients with a ventriculoperitoneal (VP) shunt tend to develop epidural fluid accumulation after cranioplasty and also have a higher frequency of syndrome of the trephined after bone flap removal. Thus treatment of patients with postcranioplasty infection and a VP shunt is often challenging.

CASE DESCRIPTION

We treated 2 patients with postcranioplasty infection and a VP shunt. One patient had undergone decompressive craniectomy for cerebral hemorrhage, and the other patient had a large frontal dead space following resection of a brain tumor. Both patients were treated by immediate cranioplasty with obliteration of the epidural dead space by using a vascularized free latissimus dorsi muscle flap. In both of them, the postoperative course was uneventful without any complications.

CONCLUSIONS

Immediate cranioplasty and obliteration of the epidural dead space with a vascularized free latissimus dorsi muscle flap is an alternative for patients with postcranioplasty infection who are unfavorable candidates for temporary bone flap removal because of the risk of neurologic deterioration.

Versatility of the Latissimus Dorsi Free Flap during the Treatment of Complex Postcraniotomy Surgical Site Infections

Background:

Some intractable cases of postcraniotomy infection, which can involve compromised skin, an open frontal air sinus, and residual epidural dead space, have been reported. In such cases, reconstructing the scalp and skull is challenging.

Methods:

Between 2009 and 2016, the author treated 12 patients with recalcitrant postcraniotomy surgical site infections with latissimus dorsi (LD) free flaps. The patients’ ages ranged from 37 to 79 years (mean, 63.5 years), and their underlying diseases included subarachnoid hemorrhaging (n = 5), brain tumors (n = 4), and cerebral arteriovenous malformations (n = 3).

Results:

The LD free flap was used for scalp reconstruction in 3 cases, scalp reconstruction and separation of the intracranial and nasal cavities in 5 cases, and the obliteration of epidural dead space in 4 cases. Debridement followed by staged cranial reconstruction was carried out in 8 cases, and single-stage cranial reconstruction was conducted in 2 cases. The bone defects of the other 2 cases, which were small, were filled with LD musculo-adipose free flaps. The postoperative local appearance of the wounds was acceptable in every case, and no complications occurred.

Conclusions:

The LD free flap is a versatile tool for the treatment of complex postcraniotomy surgical site infections. This vascularized muscle flap is useful for controlling local infections because of its abundant vascularity. Moreover, its variety of uses means that it can resolve several problems in cases involving complex cranial wounds.

Syndrome of the Trephined: A Systematic Review

BACKGROUND

Syndrome of the trephined (SoT) is a rare, important complication of a craniectomy characterized by neurological dysfunction that improves with cranioplasty. Its varied symptoms include motor, cognitive, and language deficits. Its exact characterization appears suboptimal, with differing approaches of evaluation. Accordingly, this topic is in great need of further investigation.

OBJECTIVE

To accurately describe SoT and explore methods of an objective diagnosis/evaluation.

METHODS

Electronic searches of PubMed, MEDLINE, Web of Knowledge, and PsycINFO databases used the key words "syndrome of the trephined" and "sinking skin flap." Non-English-language and duplicate articles were eliminated. Title and abstract reviews were selected for relevance. Full-text reviews were selected for articles providing individual characteristics of SoT patients.

RESULTS

This review identified that SoT most often occurs in male patients (60%) at 5.1 ± 10.8 months after craniectomy for neurotrauma (38%). The average reported craniectomy is 88.3 ± 34.4 cm and usually exists with a "sunken skin flap" (93%). Symptoms most commonly include motor, cognitive, and language deficits (57%, 41%, 28%, respectively), with improvement after cranioplasty within 3.8 ± 3.9 days. Functional independence with activities of daily living is achieved by 54.9% of patients after 2.9 ± 3.4 months of rehabilitation. However, evaluation of SoT is inconsistent, with only 53% of reports documenting objective studies.

DISCUSSION

SoT is a variable phenomenon associated with a prolonged time to cranioplasty. Due to current weaknesses in objectivity, we hypothesize that SoT is often underdiagnosed and recommend a multifaceted approach for consistent evaluation.

CONCLUSION

SoT is a serious complication that lacks exact characterization and deserves future investigation. Improved understanding and recognition have important implications for early intervention and patient outcomes.

ABBREVIATIONS

ADLs, activities of daily livingCBF, cerebral blood flowSoT, syndrome of the trephinedVP, ventriculoperitoneal.

Septic complication following porous hydroxyapatite cranioplasty: prosthesis retention management

After failing of autologous cranioplasty or when the bone flap is unavailable, the alloplastic (heterologous) materials are the choice for cranial reconstruction. No agreement has been reported about the material with a significant lower risk of septic complications. This is due to extremely heterogeneous prognostic factors related not only to the material used but also to the surgical procedures and/or to the timing of the procedure. More attention should be focused on the material whose characteristic could enable a delay in bacterial colonization, where an antibiotic therapy could be effective, without need of prosthesis removal. Four cases of severe septic complication following cranioplasty with porous hydroxyapatite (HA) prosthesis are presented. Patients were conservatively treated, without heterologous bone flap removal. All of our patients presented reasons for delaying HA cranioplasty removal: patients #1, 3, and 4 had an associated shunted hydrocephalus and the need for not removing the prosthesis was related to the predictable recurrence of overshunting and/or sinking skin flap syndrome. In patient #4, the revision surgery would have also damaged the microvascular flap with latissimus dorsi muscle used by plastic surgeon for skin reconstruction. In patient #2, the patient refused revision surgery. In all cases, systemic and/or radiological signs of infection were observed. In patient #2 the infective process surrounded completely the HA prosthesis, while it was located in the epidural region in patients #1 and 4. In patient #3, a surgical curettage of the infected wound was performed over the HA prosthesis. Following prosthesis retention management with antibiotic therapy, all patients revealed systemic and/or radiological signs of sepsis resolution at follow-up. The possibility to avoid a prosthesis removal with effective antibiotic treatment is mainly due to the combination of three factors: targeted antibiotic therapy, good anatomical area revascularization (resulting of an "in situ" intake of antibiotics), and the biomimetism of HA prosthesis. Further investigations in a larger number of cases need to confirm these observations.