Predicting and reducing cranioplasty infections by clinical, radiographic and operative parameters – A historical cohort study

Rates of operative intervention for infection after synthetic or autologous cranioplasty: a National Readmissions Database analysis

OBJECTIVE

The aim of this study was to characterize the clinical utilization and associated charges of autologous bone flap (ABF) versus synthetic flap (SF) cranioplasty and to characterize the postoperative infection risk of SF versus ABF using the National Readmissions Database (NRD).

METHODS

The authors used the publicly available NRD to identify index hospitalizations from October 2015 to December 2018 involving elective ABF or SF cranioplasty after traumatic brain injury (TBI) or stroke. Subsequent readmissions were further characterized if patients underwent neurosurgical intervention for treatment of infection or suspected infection. Survey Cox proportional hazards models were used to assess risk of readmission.

RESULTS

An estimated 2295 SF and 2072 ABF cranioplasties were performed from October 2015 to December 2018 in the United States. While the total number of cranioplasty operations decreased during the study period, the proportion of cranioplasties utilizing SF increased (p < 0.001), particularly in male patients (p = 0.011) and those with TBI (vs stroke, p = 0.012). The median total hospital charge for SF cranioplasty was $31,200 more costly than ABF cranioplasty (p < 0.001). Of all first-time readmissions, 20% involved surgical treatment for infectious reasons. Overall, 122 SF patients (5.3%) underwent surgical treatment of infection compared with 70 ABF patients (3.4%) on readmission. After accounting for confounders using a multivariable Cox model, female patients (vs male, p = 0.003), those discharged nonroutinely (vs discharge to home or self-care, p < 0.001), and patients who underwent SF cranioplasty (vs ABF, p = 0.011) were more likely to be readmitted for reoperation. Patients undergoing cranioplasty during more recent years (e.g., 2018 vs 2015) were less likely to be readmitted for reoperation because of infection (p = 0.024).

CONCLUSIONS

SFs are increasingly replacing ABFs as the material of choice for cranioplasty, despite their association with increased hospital charges. Female sex, nonroutine discharge, and SF cranioplasty are associated with increased risk for reoperation after cranioplasty.

Length of preoperative hospital stay is the dominating risk factor for surgical site infection in neurosurgery: A cohort data-driven analysis

Background:

The number of days of preoperative hospital stay (PHS) is a modifiable variable that has shown contradictory surgical site infection (SSI) risk factor results in neurosurgery. We sought to pinpoint the day of PHS length related with a marked increase of risk of SSI.

Methods:

From a tertiary teaching hospital, January 2015–December 2017, prospectively collected nonpercutaneous neurosurgery procedures with standard antibiotic prophylaxis and 1-year follow-up were evaluated. SSI risk factors were assessed through multiple logistic regression models with different thresholds of PHS.

Results:

A total of 1012 procedures were included in the study. Incidence of SSI was 4.4%. The median PHS was higher in those with SSI than in those without (1 day, interquartile range [IQR]: 7 vs. 0 days, IQR: 1, respectively, P = 0.002). By the amount of six days of PHS, this exposure risk past the threshold of significance for impact on wound infection (OR 2.8; CI 1.23–6.39, P = 0.014). Operative time past 4 h (OR 2.11; CI 1.12-3.98; P = 0.021), and in some models, previous surgery at same admission were also identified by multivariate analysis as increasing postoperative SSI risk.

Conclusion:

The gradual increase of the SSI OR associated with longer PHS days was the highest risk factor of SSI in our cohort of patients. Studies directed to reduce this complication should consider the PHS.

Factors predicting complications following cranioplasty

This study aimed to identify factors that predict complications following cranioplasty, by conducting a retrospective cohort study at a large tertiary care center. Electronic databases were searched to identify all patients who underwent cranioplasty at our institution. Baseline demographics, perioperative variables, and outcomes were extracted. Logistic regression analyses were conducted to identify factors associated with cranioplasty complications. Of the 92 included patients, 15 (16.3%) experienced one or more complications, with 11 (73.3%) experiencing complication within 30 days of cranioplasty. Patients aged ≤60 had decreased odds of all-cause complication (OR 0.058; 95% CI 0.008-0.434) and cranioplasty graft removal (OR 0.035; 95% CI 0.004-0.321) on multivariate analysis. Titanium mesh cranioplasties were associated with increased odds of all-cause complication (OR 19.776; 95% CI 1.021-382.901), and cranioplasty removal (OR 29.780; 95% CI 1.330-666.878). A longer craniectomy-cranioplasty interval was associated with increased odds of cranioplasty removal (OR 1.005; 95% CI 1.000-1.010). An initial craniectomy indication of cerebral infarction was associated with decreased odds of all-cause complication (OR 0.042; 95% CI 0.002-0.876) and cranioplasty removal (OR 0.032; 95% CI 0.001-0.766). Elderly patients may require more aggressive follow-up and antibiotic prophylaxis in the postoperative period following cranioplasty. Additionally, avoiding the use of titanium mesh cranioplasties and prolonged craniectomy-cranioplasty intervals may further reduce complications.

Complications of Cranioplasty in Relation to Material: Systematic Review, Network Meta-Analysis and Meta-Regression

BACKGROUND

Cranioplasty is a ubiquitous neurosurgical procedure consisting of reconstruction of a pre-existing calvarial defect. Many materials are available, including polymethylmethacrylate in hand-moulded (hPMMA) and prefabricated (pPMMA) form, hydroxyapatite (HA), polyetheretherketone (PEEK) and titanium (Ti).

OBJECTIVE

To perform a network meta-analysis (NMA) to assess the relationship between materials and complications of cranioplasty.

METHODS

PubMed/MEDLINE, Google Scholar, EMBASE, Scopus, and The Cochrane Library were searched from January 1, 1990 to February 14, 2021. Studies detailing rates of any of infections, implant exposure, or revision surgery were included. A frequentist NMA was performed for each complication. Risk ratios (RRs) with 95% CIs were calculated for each material pair.

RESULTS

A total of 3620 abstracts were screened and 31 full papers were included. Surgical revision was reported in 18 studies and occurred in 316/2032 cases (14%; 95% CI 11-17). PEEK had the lowest risk of re-operation with a rate of 8/157 (5%; 95% CI 0-11) in 5 studies, superior to autografts (RR 0.20; 95% CI 0.07-0.57), hPMMA (RR 0.20; 95% CI 0.07-0.60), Ti (RR 0.39; 95% CI 0.17-0.92), and pPMMA (RR 0.14; 95% CI 0.04-0.51). Revision rate was 131/684 (19%; 95% CI 13-25; 10 studies) in autografts, 61/317 (18%; 95%CI 9-28; 7 studies) in hPMMA, 84/599 (13%; 95% CI 7-19; 11 studies) in Ti, 7/59 (9%; 95% CI 1-23; 3 studies) in pPMMA, and 25/216 (12%; 95% CI 4-24; 4 studies) in HA. Infection occurred in 463/4667 (8%; 95% CI 6-11) and implant exposure in 120/1651 (6%; 95% CI 4-9).

CONCLUSION

PEEK appears to have the lowest risk of cranioplasty revision, but further research is required to determine the optimal material.

Latissimus Dorsi-Myocutaneous Flap in the Repair of Titanium Mesh Exposure and Scalp Defect After Cranioplasty

Titanium mesh was widely used for cranium defect repair but associated with high complication rates. In this study, the authors describe a method using latissimus dorsi-myocutaneous flap in the repair of titanium mesh exposure and scalp defect after cranioplasty, and the plate retaining is also achieved. Fifteen patients from April 2012 to May 2016 underwent this procedure, the age ranged from 32 to 62 years and 47 years old on average, and all the patient had plate exposure combined with surgical site infection and variation of scalp defect. All the patients had fully flap survive, and follow up ranged from 6 months to 24 months, 1 patient had titanium mesh re-expose and received additional operation to remove the plate. The free latissimus dorsi musculocutaneous flap could supply large size of bulky tissue coverage with good blood supply and strong anti-infection ability. This method was an option for retaining the titanium mesh and repairing the exposure for the mild infection with small size scalp defect patient.

Hair-sparing technique using absorbable intradermal barbed suture versus traditional closure methods in supratentorial craniotomies for tumor

BACKGROUND

Hair-sparing techniques in cranial neurosurgery have gained traction in recent years and previous studies have shown no difference in infection rates, yet limited data exists evaluating the specific closure techniques utilized during hair-sparing craniotomies. Therefore, it was the intention of this study to evaluate the rate of surgical site infections (SSIs) and perioperative complications associated with using an absorbable intradermal barbed suture for skin closure in hair-sparing supratentorial craniotomies for tumor in order to prove non-inferiority to traditional methods.

METHODS

A retrospective review of supratentorial craniotomies for tumor by a single surgeon from 2011 to 2017 was performed. All perioperative adverse events and wound complications, defined as a postoperative infection, wound dehiscence, or CSF leak, were compared between three different groups: (1) hair shaving craniotomies + transdermal polypropylene suture/staples for scalp closure, (2) hair-sparing craniotomies + transdermal polypropylene suture/staples for scalp closure, and (3) hair-sparing craniotomies + absorbable intradermal barbed suture for scalp closure.

RESULTS

Two hundred sixty-three patients underwent hair shaving + transdermal polypropylene suture/staples, 83 underwent hair sparing + transdermal polypropylene suture/staples, and 100 underwent hair sparing + absorbable intradermal barbed suture. Overall, 2.9% of patients experienced a perioperative complication and 4.3% developed a wound complication. In multivariable analysis, the use of a barbed suture for scalp closure and hair-sparing techniques was not predictive of any complication or 30-day readmission. Furthermore, the absorbable intradermal barbed suture cohort had the lowest overall rate of wound complications (4%).

CONCLUSIONS

Hair-sparing techniques using absorbable intradermal barbed suture for scalp closure are safe and do not result in higher rates of infection, readmission, or reoperation when compared with traditional methods.

Management and prevention of cranioplasty infections

BACKGROUND

Infection may complicate the outcome of cranial repair with significant additional morbidity, related to hospitalization, surgery and long antibiotic therapy, that may become even dramatic in case of multi-resistant germs and in particular in the paediatric population. Additionally, the economic costs for the health system are obvious. Moreover, surgical decisions concerning the timing of cranioplasty and choice of the material may be strongly affected by the risk of infection. Despite, management and prevention of cranioplasty infections are not systematically treated through the literature so far.

METHODS

We reviewed pertinent literature dealing with cranioplasty infection starting from the diagnosis to treatment options, namely conservative versus surgical ones. Our institutional bundle, specific to the paediatric population, is also presented. This approach aims to significantly reduce the risk of infection in first-line cranioplasty and redo cranioplasty after previous infection.

CONCLUSIONS

A thorough knowledge and understanding of risk factors may lead to surgical strategies and bundles, aiming to reduce infectious complications of cranioplasty. Finally, innovation in materials used for cranial repair should also aim to enhance the antimicrobial properties of these inert materials.

Risk factors for surgical site infection after craniotomy: a prospective cohort study

Background

Although surgical site infection after craniotomy (SSI-CRAN) is a serious complication, risk factors for its development have not been well defined. We aim to identify the risk factors for developing SSI-CRAN in a large prospective cohort of adult patients undergoing craniotomy.

Methods

A series of consecutive patients who underwent craniotomy at a university hospital from January 2013 to December 2015 were prospectively assessed. Demographic, epidemiological, surgical, clinical and microbiological data were collected. Patients were followed up in an active post-discharge surveillance programm e for up to one year after surgery. Multivariate analysis was carried out to identify independent risk factors for SSI-CRAN.

Results

Among the 595 patients who underwent craniotomy, 91 (15.3%) episodes of SSI-CRAN were recorded, 67 (73.6%) of which were organ/space. Baseline demographic characteristics were similar among patients who developed SSI-CRAN and those who did not. The most frequent causative Gram-positive organisms were Cutibacterium acnes (23.1%) and Staphylococcus epidermidis (23.1%), whereas Enterobacter cloacae (12.1%) was the most commonly isolated Gram-negative agent. In the univariate analysis the factors associated with SSI-CRAN were ASA score > 2 (48.4% vs. 35.5% in SSI-CRAN and no SSI-CRAN respectively, p = 0.025), extrinsic tumour (28.6% vs. 19.2%, p = 0.05), and re-intervention (4.4% vs. 1.4%, p = < 0.001). In the multivariate analysis, ASA score > 2 (AOR: 2.26, 95% CI: 1.32–3.87; p = .003) and re-intervention (OR: 8.93, 95% CI: 5.33–14.96; p < 0.001) were the only factors independently associated with SSI-CRAN.

Conclusion

The risk factors and causative agents of SSI-CRAN identified in this study should be considered in the design of preventive strategies aimed to reduce the incidence of this serious complication.

Electronic supplementary material

The online version of this article (10.1186/s13756-019-0525-3) contains supplementary material, which is available to authorized users.

Cranioplasty: An Institutional Experience

Cranioplasty is a common procedure in neurosurgical practice, but associated with high complication rates. In the current study, the authors describe surgical characteristics and results of cranioplasty performed in a tertiary teaching hospital in Brazil. Data were obtained from electronic medical records of cranioplasties performed between January 2013 and November 2016. The sample comprised of 33 patients, and the mean follow-up time was 16 months. Patients presented most of the times a good preoperative status, with 84.8% of patients classified between 0 and 3 at modified Rankin scale and 78.7% with 4 or 5 points at Glasgow Outcome Scale. The most common initial diagnosis was vascular disease (48% of patients) followed by traumatic brain injury (36% of patients). The majority of cranioplasties used an autograft: the autologous bone flap removed during a previous surgery (craniectomy) and stored in the abdominal subcutaneous fat (67% of patients). In 3 patients, the polymethylmethacrylate prosthesis was custom-made prior to the operation using 3-dimensional printing, based on computed tomography images. Five patients (15% of patients) developed symptoms related to surgical site infection, manifesting at an average of 5 weeks following the procedure. Three of them presented scalp dehiscence before the infection symptoms. Cranioplasty should be performed early, as long as clinical conditions are good and the patient has overcome the acute phase of neurological injury.

Successful Strategies for Dealing With Infected, Custom-Made Hydroxyapatite Cranioplasty

When a cranioplasty implant becomes infected, standard operating procedure dictates its removal and the initiation of a long course of antibiotic therapy. However, removing such a prosthesis can have a series of adverse consequences, including delayed cognitive and motor recovery, lack of brain tissue protection, unsightly deformity, and the need for two additional surgical procedures, not to mention the additional costs involved. To maintain the advantages of cranioplasty, we opted for a conservative approach (levofloxacin and rifampicin every 24 hours for 8 weeks) in a 68-year-old woman whose custom-made porous hydroxyapatite implant, fitted following aneurysm clipping, had become infected. The tissues overlying the implant were curettaged, and the patient's clinical condition, blood markers, and infection course were continuously monitored (local monitoring was performed by single-photon emission computed tomography [SPECT]/computed tomography [CT after intravenous administration of Tc-labeled antigranulocyte antibody). Blood tests and SPECT/CT evidenced a progressive reduction in phlogosis indices and infection locus, even 1 month after antibiotic therapy was commenced, and at 2 years from cranioplasty, the same tests and clinical examination were negative. At 6-year follow-up, clinical assessment revealed nothing out of the ordinary.Hence, specific cases (hydroxyapatite prosthesis, intact dura, cranial CT and magnetic resonance imaging negative for empyema, well-vascularized scalp, antibiotic-responsive bacteria) of infected cranial implant can be treated using a conservative approach consisting of appropriate antibiotic therapy, accompanied by local debridement where necessary, and assiduous monitoring of phlogosis indices and local verification via labeled-leukocyte scintigraphy. Our report, which was compiled after a long-term follow-up period, shows that this conservative procedure appears to be a viable option in cases of infected, custom-made hydroxyapatite cranioplasty, provided that some basic rules concerning clinical and instrumental standards are adhered to, as clearly stated in our report.

Reduction of Surgical Site Infections After Cranioplasty With Perioperative Bundle

BACKGROUND

Surgical site infections (SSI) are the most common complication after cranioplasty and it is associated with poor prognosis. The aim of this study was to identify the risk factors that triggered the development of SSI after cranioplasty and establish a new perioperative bundle and monitoring system to reduce SSI.

METHODS

A retrospective review of a database that included all cranioplasty patients from 2001 to 2007 was carried out to determine the prevalence of infection. A surveillance team was set up, which assessed the clinical practice and led to the development of a new perioperative bundle and supervision system. A prospective study between 2008 and 2014 was carried out to observe whether infection rates had changed and whether an active surveillance program can change clinical practice.

RESULTS

Retrospective period included 86 adult patients. The overall rate of infection was 10.5% (9 SSI in 86 patients). Age ≥60 years (OR 1.05; 95% CI: 1.00-1.10; P = 0.04), smoking (OR 9.13; 95% CI: 1.65-50.60; P = 0.01), and duration of operation ≥180 minutes (OR1.19; 95% CI: 1.06-1.34; P < 0.01) as significant predictors of postcranioplasty SSI development. Length of preoperative stay and length of hospitalization was significantly longer among infected patients compared with uninfected patients (P < 0.01, respectively). In prospective period, the general SSI rate was reduced to 1.8% (2 SSI in 113 patients). The difference was statistically significant (P = 0.01).

CONCLUSIONS

A perioperative bundle and monitoring system may help to reduce SSI rates after cranioplasty. This work also indicates how an active surveillance program can successfully change clinical practice.

Never say never again: A bone graft infection due to a hornet sting, thirty-nine years after cranioplasty

Background:

Cranioplasty (CP) is a widespread surgical procedure aimed to restore skull integrity and physiological cerebral hemodynamics, to improve neurological functions and to protect the underlying brain after a life-saving decompressive craniectomy (DC). Nevertheless, CP is still burdened by surgical complications, among which early or late graft infections are the most common outcome-threatening ones.

Case Description:

We report the case of 48-year-old man admitted to our neurosurgical unit because of a painful right frontal swelling and 1-week purulent discharge from a cutaneous fistula. He had been undergone frontal CP because of severe traumatic brain injury (TBI) when he was 9-year-old. Since then, his medical history has been being unremarkable without any surgical or infective complication of the graft for 39 years, until he was accidentally stung by a hornet in the frontal region. After the CT scan and laboratory findings had evidenced a probable infection of the graft, the patient was treated by vancomycin and cefepime before he underwent surgical revision of its former CP, with the removal of the graft and the debridement of the surgical field. Subsequent bacteriological tests revealed Staphylococcus aureus as causal agent of that infection.

Conclusion:

This case illustrates an anecdotal example of very late CP infection, due to an unpredictable accident. Due to lack of consensus on risk factors and on conservative or surgical strategy in case of graft infection, we aimed to share our surgical experience.