Surgical Management of Pseudomeningocele Combined with Intracranial Infections Following Neurosurgical Operation

Abstract

Background:

Pseudomeningocele is a common post-operative complication after a neurosurgical operation. Infection combined with pseudomeningocele can induce substantial morbidity. We presented a series of cases with pseudomeningocele combined with intracranial infection following neurosurgical operation focusing on operative technique and long-term clinical outcome. This study aimed to determine the efficacy of the novel surgical technique in tackling the intractable post-operative complication.

Methods:

A retrospective analysis of patients with pseudomeningocele and intracranial infection following neurosurgical operations between 2012 and 2024 was performed. Standard statistical methods helped explore the associations between parameters requiring reoperation. The authors described surgical techniques and treatment strategies for pseudomeningocele combined with intracranial infection after a neurosurgical operation.

Results:

Of the 58 patients, 17 (29.3%) presented with post-operative pseudomeningocele, which was refractory to conservative treatment along with intracranial infection requiring surgical management. Pseudomeningocele requiring reoperation was much more likely in patients with craniectomy and those with craniotomy (41.9% vs. 14.8%, p = 0.024). Moreover, pseudomeningocele was more likely in patients without watertight closures than with (52.2% vs. 14.3%, p = 0.002). The post-operative image indicated no recurrence in these patients who underwent reoperation.

Conclusions:

The novel operative technique could successfully treat pseudomeningocele combined with intracranial infection refractory after a neurosurgical operation.

Many studies have reported the complication of bulging of the wound following neurosurgical operations.^1–3 Parizek et al. reported an incidence of up to 28% for post-operative pseudomeningoceles.⁴ The cerebrospinal fluid (CSF) leakage is the most common and severe complication after operations. It usually occurs several days after surgical procedure completion and appears as pseudomeningocele. Persistent leakage remaining untreated may result in wound dehiscence, leading to local wound or intracranial infection. Treatment of pseudomeningocele along with intracranial infection includes conservative management in head elevation, antibiotic administration, acetazolamide, and local bandage compression. Aspiration of CSF from subcutaneous space or continuous lumbar drainage could be used in cases where conservative management fails. If these measures fail, reoperation would be the final choice. This is especially true for patients with intracranial infection. The present study shares our experience in tackling this intractable post-operative complication while determining the efficacy of the novel surgical technique.

Patients and Methods

Study cohort

The data of adult patients who underwent the neurosurgical operation at the First Affiliated Hospital of Jinan University, Guangzhou, China, were retrospectively reviewed between March 2012 and May 2024. Only cases who presented with pseudomeningocele combined with intracranial infection after a neurosurgical operation are included in this study. The patient’s clinical characteristics, clinical presentation, pre- and post-operative computed tomography (CT) or magnetic resonance imaging results, and follow-up outcomes were evaluated. The study was approved by the local ethics board of our institutions (No. KY-2024-182) and was performed according to the ethical standards of the 1964 Declaration of Helsinki. Informed consent was obtained for all patients enrolled in this study.

Statistics

Statistical analyses were performed using the SPSS Statistics 23 software (IBM, Armonk, New York). Fisher exact test helped compare binomial dichotomized data, whereas the chi-squared test helped analyze the categorical data. Differences in mean values were analyzed using a Student’s t-test when appropriate. To evaluate the relative contributions of age, gender, diabetes mellitus history, current smoking status, alcohol, craniotomy type, disease, craniectomy or craniotomy, and watertight closures, uni-variable and multi-variable logistic regression analyses were performed for each parameter against pseudomeningocele combined with intracranial infection requiring surgical management. p-Values <0.05 were considered statistically significant.

Results

Patient population

In total, 58 patients were enrolled for analysis between March 2012 and May 2024. Among them, 17 patients had an intracranial infection along with pseudomeningocele and received surgical management. Clinical characteristics of patients requiring surgical management were compared with those not requiring reoperation (Table 1). Pseudomeningocele requiring reoperation was much more likely in craniectomy patients than those with craniotomy (41.9% vs. 14.8%, p = 0.024). In addition, substantial differences could be observed in patients requiring reoperation and having watertight closures compared with those without a watertight closure (14.3% vs. 52.2%, p = 0.002). The multi-variable binary logistic regression analyses revealed that patients without watertight closures had more than six-fold greater odds of reoperation (odds ratio [OR]: 6.545; 95% confidence interval [CI]: 1.873–22.875; p = 0.003) compared with those with watertight closures (Table 2).

Table 1.

Parameters Associated with Pseudomeningocele Combined with Intracranial Infections Following Neurosurgical Operation

	Requiring operation (n = 17)	Conservative treatment (n = 41)	p
Mean age, y (SD)	47.35 (14.14)	48.49 (14.02)	0.924
Gender			0.49
Male	10 (58.8%)	28 (68.3%)
Female	7 (41.2%)	13 (31.7%)
Diabetes mellitus			0.742
Yes	2 (11.8%)	8 (19.5%)
No	15 (88.2%)	33 (80.5%)
Currently smoking			0.555
Yes	3 (17.6%)	12 (29.3%)
No	14 (82.4%)	29 (70.7%)
Alcohol			0.912
Yes	2 (11.8%)	7 (17.1%)
No	15 (88.2%)	34 (82.9%)
Type of operation			0.990
Superior operation	3 (17.6%)	9 (22.0%)
Inferior operation	14 (82.4%)	32 (78.0%)
Disease			0.195
Hemorrhage	9 (52.9%)	20 (48.8%)
Tumor	5 (29.4%)	19 (46.3%)
Infarction	3 (17.6%)	2 (4.9%)
Bone flap status			0.02**
Craniectomy	13 (76.5%)	18 (43.9%)
Craniotomy	4 (23.5%)	23 (56.1%)
Watertight closures			0.002*
Yes	5 (29.4%)	30 (73.2%)
No	12 (70.6%)	11 (26.8%)

Statistically significant.

SD = standard deviation.

Table 2.

Uni-variable and Multi-variable Logistic Regression Models of Parameters Associated with Pseudomeningocele Requiring Operation

	Uni-variable			Multi-variable
	Odds ratio	95% Confidence interval	p	Odds ratio	95% Confidence interval	p
Age	0.964	0.905–1.028	0.267
Female	4.891	0.470–50.872	0.184
Diabetes mellitus	0.809	0.083–7.867	0.855
Currently smoking	0.220	0.018–2.756	0.240
Alcohol	3.285	0.409–26.400	0.263
Type of operation
Superior operation
Inferior operation	0.429	0.045–4.074	0.461
Disease
Hemorrhage
Tumor	0.062	0.004–1.076	0.056
Infarction	0.105	0.009–1.231	0.073
Craniectomy	2.640	0.383–18.222	0.325
Watertight closures	26.288	2.230–309.949	0.009^*	6.545	1.873–22.875	0.003^*

Statistically significant.

Surgical procedure

Before the operation, we defined the area of the ipsilateral trapezius muscle to be freed. The original incision was made, and the inflammatory tissue was completely removed. All artificial materials, such as dural graft, silk, and bone wax, were completely removed. Because of the thinness and atrophy of the muscle tissue around the incision, it could not be sutured. Hence, we isolated the pre-designated area of the trapezius muscle with the fascia, thus retaining the blood supply to the muscle pedicle. Then, we flipped the pedicled trapezius muscle so that the surface of the defective skull was completely covered. Finally, absorbable sutures were used to stitch the subcutaneous tissue and skin into layers. The lumbar drainage was continuously opened to drain for about 7–14 days with 200–300 mL per day, with a median blood loss of 420 mL (from 100 to 1,100 mL) during operation.

Follow-up and outcome

The mean overall follow-up period of the study was 21.2 months (range: 2–96 mo). Among the 17 patients who received surgical management, the imaging examination at the last follow-up demonstrated that they had no pseudomeningocele (Fig. 1). One patient died in the two-month post-operative because of a non-operation-related cause. The patient with sepsis and severe pneumonia experienced multi-organ failure because of septic shock. One patient had hydrocephalus before surgical procedure, which disappeared after operation (Fig. 2).

FIG. 1.

(A and B) Pre-operative CT scans indicated that the patient had a pseudomeningocele in the posterior fossa area. This patient also had an incision leakage and intracranial infection. (C and D) CT scan images after one month of reoperation indicated the removal of pseudomeningocele. CT = computed tomography.

FIG. 2.

(A, B, and C) The pre-operative CT scan demonstrated that the patient had a pseudomeningocele in the posterior fossa area with hydrocephalus. However, this patient has an intracranial infection; the bacteria is Staphylococcus aureus. (D, E, and F) CT scan images after three months of reoperation showed that the pseudomeningocele had been removed while substantially relieving the hydrocephalus. CT = computed tomography.

Case presentation

A 49-year-old female presented to our emergency department with deep coma status and two-sided pupil enlargement. The head CT scan indicated a large lesion located in the left temporal–occipital lobe with severe herniation. We performed an emergency operation to remove the lesion, followed by decompressive craniectomy. In the post-operative period, the patient had a prominent bulge in the left temporal–occipital region and presented with vomiting, high fever, and severe headache. Inflammation CSF leakage was observed at the incision site. The CT and MR scan depicted a prominent pseudomeningocele in the operation area. Continuous lumbar drainage and bandage compression were performed, and the CSF bacterial culture was positive for Staphylococcus aureus. The pseudomeningocele recurred once after stopping the lumbar drainage and bandage compression. We used trapezius pedicled muscle flaps to repair the defect. CSF culture was positive for Enteroaerogen, and vancomycin was initiated. The patient recovered after the procedure and was discharged from the hospital. The bulge was because of the infectious subcutaneous collections, and the local skin swelling disappeared after the procedure (Fig. 3).

FIG. 3.

(A, D, and G) Pre-operative T1-weighted enhanced MRI images scan showed the patient had a pseudomeningocele with a prominent bulge in the left temporal–occipital region. After nine days of the surgical procedure. (B, E, and H) T1-weighted enhanced MRI images showed that the pseudomeningocele had been removed, and the bulge had disappeared. (C, F, and I) In the follow-up period, enhanced MRI images indicated satisfactory outcomes after six months of reoperation. MRI = magnetic resonance imaging.

Discussion

Post-operative pseudomeningocele is an undesirable complication involving neurosurgical procedures. It occurs more frequently after posterior fossa surgical procedures.⁵ Our previous work has depicted that patients with pseudomeningocele can have a significantly greater risk of intracranial infection after posterior fossa operation.⁶ Pseudomeningocele is troublesome, and the combination of intracranial infection can make treatment even more challenging. This study analyzed 58 patients with pseudomeningocele and intracranial infection after the neurosurgical operation. These patients involved both supratentorial and posterior fossa craniotomy. Among them, 41 used the repeated aspiration of collections subcutaneously combined with mechanical compression with a head bandage or lumbar drainage to resolve the problem. However, the remaining 17 patients failed to respond to conservative treatment; thus, surgical management was performed. No patients suffered from operation-related death, and the outcome of post-operative imaging was good.

Whether a preserved bone flap will decrease the post-operative pseudomeningocele risk seems controversial. Some studies reported that patients undergoing craniotomy procedures could have a rate as low as 6% to 13% for pseudomeningocele. However, in patients where a craniectomy procedure was performed, the rate of pseudomeningocele was from 30% to 50%.^7–9 Thus, most studies favored craniotomy over craniectomy because it has increased complications of CSF leak and pseudomeningocele, especially in posterior fossa surgical procedures.^10–12 In our retrospective study, the rate of receiving surgical management is lower in patients with craniotomy than those with craniectomy (14.8% vs. 41.9%, p = 0.024). This is like our observation in clinical situations. When intracranial infections are cured using antibiotic agents, the pseudomeningocele can be removed by compression bandage and lumber drainage. The reason why a preserved bone flap can decrease the risk of forming pseudomeningocele after a craniotomy could be because the bone flap can act as a rigid support tamponade against any surge in CSF pressure because of post-operative subarachnoid space filling with CSF.¹² This tamponade prevents dural sutures from giving away or a small defect from becoming larger when intracranial pressure increases severely because of patient strain or cough in the post-operative period. A rigid support is critical for treating pseudomeningocele after aspirating the collections from the subcutaneous area. Second, the bone flap can behave as a barrier to CSF leak. Finally, the bone flap may obliterate any potential dead space for CSF collection. However, preserved bone flap was not a predictor of reoperation requirement in the uni-variable analysis (OR: 2.640, CI: 0.383–18.222; p = 325). The relatively small sample size in this study may induce this outcome.

Patients without achieving a watertight closure intraoperative procedure had 6.5 times the odds of requiring reoperation to eliminate the pseudomeningocele combined with intracranial infection compared with those with a watertight closure (OR: 6.545, CI: 1.873–22.875; p = 0.003). Intraoperative watertight closure has been discussed across the literature.^9,13,14 The patient’s failure to achieve watertight closure is more likely to require reoperation to eliminate the pseudomeningocele. Therefore, we hypothesized that this could be because a large amount of CSF was constantly discharged from the large dural defect to develop the pseudomeningocele like a valve. Thus, removing the pseudomeningocele using conservative treatment could be difficult. Therefore, we used the trapezius muscle with the fascia during reoperation to cover the dural defect.

Failure of complete dural closure after neurosurgical procedures may not always be possible and is because of contraction of dural edges after prolonged surgical procedure or brain swelling from retraction and/or manipulation.⁹ In these situations, a dural graft is necessary for dural closure. However, Steinbok et al. found that using a dural graft was related to greater rates of pseudomeningocele or CSF leakage in patients (41.0% vs. 27.7%), although this trend was not statistically significant (p = 0.06492).¹³ For patients with pseudomeningocele with intracranial infection, the bacteria may attach to the dural graft, leading to difficulty in controlling infection. Thus, every case in our study that requires reoperations to remove the pseudomeningocele has completely removed the dural graft.

Methods described in other studies are mostly for simple post-operative pseudomeningocele without intracranial infection. Previously, we reported seven cases requiring surgical procedures to deal with this complication. However, the sample is relatively small, and all the cases involved require posterior fossa operation.¹⁵ In this study, we enlarged the sample and focused on introducing and determining the efficacy of the novel surgical technique for tackling the intractable post-operative complication after a neurosurgical procedure. Some studies reported using a lumboperitoneal or pseudocyst-peritoneal shunt to treat persistent pseudomeningocele collection. However, it also faced the risk of having complications such as pneumocephalus, neurenteric cysts, and acute subdural hematoma.^5,16–19 For patients with an intracranial infection, shunt surgical procedure must be avoided. In addition, not all patients remain comfortable with lifelong shunt devices, especially younger patients.

Some study limitations should be further discussed. The retrospective nature and relatively small sample size may affect the statistical results. Some other potential risk factors were not included in this study, including the hydrocephalus, patients’ nutritional status, and Body Mass Index (BMI). For patients with post-operative hydrocephalus, ventriculoperitoneal shunt operation helped remove the pseudomeningocele after controlling the intracranial infection. This study excluded these patients, causing some bias.

Conclusion

In our clinical case series with 17 patients, novel surgical management can help remove the pseudomeningocele combined with intracranial infection. The clinical and radiological outcomes were satisfactory. This surgical procedure is an excellent chance to cure such complications, as the present experience indicates. The procedure may be considered as an alternative treatment for pseudomeningocele combined with an intracranial infection that does not respond to conservative management.

Footnotes

Acknowledgments

The authors thank all the peer reviewers and editors for their opinions and suggestions.

Authors’ Contributions

Conception and design and provision of study materials or patients: D.W.-L. and W.X.-Y. Administrative support: Y.J.-B. Collection and assembly of data: J.W. and G.S.-J. Data analysis and interpretation: D.W.-L. and G.S.-J. Article writing and final approval of the article: all authors.

Author Disclosure Statement

The authors declare no competing interests.

Funding Information

The authors declare that no funds, grants, or other support were received during the preparation of this article.

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