Decompressive craniectomy with watertight duroplasty and without watertight duroplasty - advantages and disadvantages

Overview

Background: Decompressive craniectomy (DC) is a life-saving neurosurgical procedure with several technical options. Aim: The aim of this study was to compare the results of the DC surgical technique with and without duroplasty performed at two neurosurgery departments. Methods: A retrospective bicentric study evaluated the occurrence of complications (i.e., infection, cerebrospinal fluid fistula, hematoma) in both compared techniques. Results: The study did not demonstrate a statistically significantly higher incidence of complications such as infection (P = 0.539), cerebrospinal fluid fistula (P = 0.826) or hematoma (P = 0.720). No infectious complications or cerebrospinal fluid fistula were recorded in both observed groups after cranioplasty. The complication in the form of hematoma was statistically insignificant (P = 0.155). A statistically significant difference was found in the operative time of cranioplasty performed after DC with duroplasty (median 53 min) and after DC without duroplasty (median 90 min; P = 0.006). Conclusion: DC without duroplasty is a potentially safe option that is not burdened by a higher incidence of complications in terms of infection or the formation of cerebrospinal fluid fistula and hematoma.

Keywords:

decompressive craniectomy – traumatic brain injury – cranioplasty – duroplasty

This is an unauthorised machine translation into English made using the DeepL Translate Pro translator. The editors do not guarantee that the content of the article corresponds fully to the original language version.

 

Introduction

Decompressive craniectomy (DC) is a life-saving neurosurgical procedure whose main goal is to reduce pathologically elevated intracranial pressure [1,2]. This operation results in the release of brain tissue, prevention of further ischemia and restoration of perfusion [3]. The surgery itself is preceded by generally accepted procedures in the treatment of intracranial hypertension, which inherently include effective sedation of the patient and a set of other first-line therapeutic measures (hypocapnia, mannitol, etc.). If these therapies are ineffective, we proceed to second-line therapy - hyperventilation, hypothermia up to DK alone [4,5]. In addition to the correct indication and timely performance, the technique of DK itself is an important part of the procedure [6]. Recent foreign literature has repeatedly focused on the evaluation of the indications and effect of DK and, more recently, on the technique of performing the surgery itself. A very important part of the neurosurgical procedure is always the reconstruction of the dura [7]. Inadequate performance may result in the formation of a liquor pseudocyst or fistula. These complications may be subsequently compounded by inflammation, ranging from simple surgical wound infection to the development of meningitis or epidural or subdural empyema to cerebritis or brain abscess [8].

An extensive discussion on this topic was triggered by the work of Güresir et al, in which the authors present the possibility of performing DK with rapid closure of the surgical wound without duroplasty as a safe method with the benefit of shorter operative time without an increase in complications [9]. Based on this and similar papers, the question of whether such a DK procedure is safe is discussed.

In our cohort, we compared the results of two sites with different types of DK design. The main aim of the study was to compare the complication rate of DK with and without duroplasty. The other objectives were to compare the operative time according to the technique of DK, to determine whether the given technique of DK influences the difficulty of cranioplasty, and last but not least to evaluate the clinical condition of the patient.

 

Patients and methods

This bicentric retrospective study compared the results of two centers with different types of unilateral DK - with and without duroplasty. The department where duroplasty is performed during DK is the Neurosurgical Department of the Olomouc University Hospital and the compared department where duroplasty is not performed during DK is the Neurosurgical Department of the Liberec Hospital. The study included only patients with craniocerebral trauma, on the basis of which unilateral DK was indicated to be performed in 2019-2020. Patients younger than 18 years, patients with bilateral or occipital craniectomy and patients with other brain pathology were excluded from the comparison group.

DK was performed at both departments in the indicated patients. Before the actual bone removal, the staff of the Neurosurgical Clinic of the Olomouc University Hospital prepares the myoperiosteal flap, which is then used for the duroplasty. The extent of DK was modified according to the graphic findings of the patient. The size of the decompression is similar in both departments, the direction of the incision leads from the tragus and continues in the shape of the "?" sign up to about 2 cm from the midline. We remove the temporal bone squama to thoroughly decompress the temporal lobe. This is followed by durotomy, evacuation of the hematoma and hemostasis. In individual cases, the contusion lesion was resected or the intracerebral hematoma was evacuated. At the Neurosurgical Clinic of the University Hospital Olomouc, duroplasty is performed using a prepared myoperiosteal flap, possibly with an artificial substitute with suturing of a hard diaper. At the Neurosurgical Department of Liberec Hospital, duroplasty is not performed, the cut dura is placed freely on the brain tissue. In both departments, the suture is then completed after the anatomical layers (galea, skin).

Follow-up probands were retrospectively assessed and stratified by gender and age. Patients' initial clinical status was assessed using the Glasgow Coma Scale (GCS) [10] state of consciousness scoring system and according to the American Brain Injury Association (ABIA) [11] for mild (GCS 13-15), moderate (GCS 9-12) and severe trauma (GCS 8 or less). Patients were further classified according to the diagnoses into the following groups: subdural hematoma, intracerebral hematoma or contusion, and epidural hematoma. When multiple diagnoses were present simultaneously in a single patient, one main diagnosis was identified, which led to the indication for surgery and dominated according to the graphical findings. Individual complications were evaluated in the study, which included infection, liquor fistula and also any postoperative hematoma. The study also monitored and compared the length of operative time of DK performed at each department. This was defined in minutes from the start to the end of the incision according to the operative protocol. The probands were evaluated whether they underwent cranioplasty. If so, the time taken to perform it was also assessed. For the cranioplasty itself, the operative time was assessed - again defined as the start and end of the incision according to the operative protocol in minutes. Postoperative complications after cranioplasty were also assessed. Patient outcome was assessed according to the Glasgow Outcome Score (GOS) [12] after DK or after cranioplasty.

The statistical software IBM SPSS Statistics for Windows, Version 23.0 (IBM, Armonk, NY, USA) was used for statistical processing.

The quantitative variables were presented by means of medians, minimum and maximum values, means and standard deviations (SD). Shapiro-Wilkins tests of normality verified that most variables did not have a normal distribution. The Mann-Whitney U test was used to compare two independent samples in quantitative and ordinal variables; Fisher's exact test was used for qualitative data.

All tests were performed at the 5% level of statistical significance. Results with a p-value less than 0.05 were considered statistically significant.

 

Results

The individual distribution of patients according to gender, ABIA classification and diagnosis is shown in Table 1.A total of 82 patients from the Neurosurgical Clinic of the Olomouc University Hospital and 45 from the Neurosurgical Department of the Liberec Hospital were included in the follow-up. Males were dominant in both groups. The most common diagnosis was acute subdural haematoma and most patients had severe trauma according to ABIA classification.

There was no statistically significant difference in the age of the patients in the studied groups, the median age was 65.5 (23.0; 95.0) years in the group of the Neurosurgical Clinic of Olomouc University Hospital vs. 68.0 (22.0; 91.0) years in the group of the Neurosurgical Department of Liberec Hospital. The values are shown in Table 2.

The number of complications including the incidence of postoperative hematoma is shown in Table 3. There was no statistically significant difference in complications such as infectious complications, fistula or hematoma between the two types of surgical techniques for DK.

There were a total of 25 complications in the cohort of the Neurosurgical Clinic of the University Hospital Olomouc. Two infectious complications were recorded, namely brain abscess and epidural empyema. In the patient with abscess, the initial course was complicated by impaired wound healing and liquorrhoea; therefore, lumbar drainage was introduced and the patient underwent wound revision with suturing of the defect under general anaesthesia. A follow-up CT scan of the brain with contrast medium showed an abscess formation - this was subsequently punctured, drained and treated with antibiotics. In the second patient, similarly, the initial course was complicated by impaired wound healing with secretion, and antibiotic therapy was initiated. At operative revision, a sterile epidural collection was demonstrated. The condition of both patients then fully recovered after antibiotic treatment. The postoperative liquor fistula was treated with subcutaneous puncture followed by light compression in 16 patients. In two patients, in addition to puncture, external lumbar drainage was temporarily introduced. A total of five patients developed postoperative hematoma, all of which were subdural hematomas that were indicated for surgical revision and evacuation.

In the Neurosurgical Department of Liberec Hospital we recorded a total of 14 complications. No infectious complications were recorded. Postoperative liquor fistula was treated in six patients by adding sutures to the skin cover and in five patients by adding sutures in combination with temporary external lumbar drainage and subsequent adjustment of the condition. Postoperative hematoma occurred in a total of four patients, three of whom had subdural and one of whom had epidural hematoma. In one patient, both postoperative hematoma and postoperative liquor fistula occurred simultaneously. All these patients were indicated for surgical revision.

No difference in GOS was found when comparing the two sets. The results of the comparison are shown in Table 3.

Comparison of the files of the Neurosurgical Clinic of Olomouc University Hospital and the Neurosurgical Department of Liberec Hospital did not show statistically significant differences in age, initial GCS and output GOS. There was no statistically significant difference in the operating time 113 min (Neurosurgical Clinic of Olomouc University Hospital) vs. 100 min (Neurosurgical Department of Liberec Hospital). Individual data are shown in Table 2.

In both sets, cranioplasty was not performed in all patients. In some cases, further surgical intervention was not allowed by the clinical condition, some patients were lost to follow-up or refused the procedure. Both centres recommend cranioplasty 6 weeks after surgery, possibly individually according to the findings on brain CT.

A total of 23 cranioplasties (38%) were performed in the Neurosurgery Department of the Olomouc University Hospital. Two patients developed postoperative subdural hematoma requiring surgical revision.

A total of five cranioplasties (14%) were performed in the Neurosurgical Department of Liberec Hospital. Two patients developed two postoperative intracranial hematomas. In one patient it was a combination of subdural and epidural hematoma and in the other a subdural hematoma with subsequent revision. Comparison of cranioplasties and their complications is shown in Table 4.

Thus, overall, no infectious complications or liquor fistula were observed after cranioplasty in the two studied groups. There was a statistically significant difference in the operative time of cranioplasty performed at the Department of Neurosurgery, Olomouc University Hospital (median 53 min) and the Department of Neurosurgery, Liberec (median 90 min; p = 0.006). The comparison of the time in days of cranioplasty and the length of the procedure itself is shown in Table 5.

There was a difference in the number of cranioplasties performed in the study groups, but there was no difference in the timing of cranioplasty from the primary operation. A statistically significant difference was noted in the operative time of cranioplasties, but no difference was noted in the incidence of complications.

 

Discussion

Decompressive craniectomy is one of the basic surgical procedures performed in large numbers in all neurosurgical departments. The main aim of the operation is to reduce the elevated intracranial pressure to values below 20 mm Hg when the existing intensive anti-edema therapy is ineffective [13-15]. Several surgical procedures for DK have been described in the literature, which differ in the technical aspects of their performance [16]. The mainstay for unilateral expansions is always an extensive fronto-temporo parieto-occipital craniotomy/craniectomy with durotomy and hard flap plasty over 14 cm (area over 130 cm2) of the anterolateral diameter of the bone flap [17,18]. Despite many recommendations, the technique of performance often varies according to the practice of the institution and the preference of individual surgeons. Also, the closure of the dura observed in our series remains controversial, which can be performed using a musculoperiosteal flap, an arteficial substitute, or no plasty [19,20].

In DK without plasty of the hard diaper, the body's reparative mechanisms form a membrane called the neodura, which acts as a barrier, protecting the brain and preventing cerebrospinal fluid leakage, as published by Güresir et al in their groundbreaking work on the subject. Using a cohort of 341 patients, the authors concluded that DK performed using the rapid closure technique without hard-diaper plasty did not increase the percentage of liquor leakage or the incidence of infectious complications, and there was no problematic wound healing. Moreover, the operative time was significantly reduced (69 vs. 120 min) [9]. Similar results were obtained in our study, which showed no statistically significant difference in the rate of complications (liquor fistula, infectious complications, hematoma) between the set of patients with and without duroplasty of the dura. However, the reduction in operative time for DK with duroplasty (113 min) compared to DK without duroplasty (100 min) was not as significant.

Other authors who addressed this issue were Bart et al. They compared the waterproof closure of a hard diaper with suturing the dura with only a few adaptive sutures. Patients were randomized preoperatively. By evaluating the cohort, the authors concluded that the adaptive dural closure was a safe and effective alternative to waterproof dural closure [21].

Viera et al in their study also failed to demonstrate an association between unperformed water-tight duroplasty and a higher incidence of complications in DK. The authors concluded that an intact arachnoid reduces the risk of cerebrospinal fluid leakage, and furthermore, dura suture may create small one-way valves leading to subsequent cerebrospinal fluid leakage. A secondary finding of the authors of this paper, in addition to the reduction in operative time, was the reduction in material costs (operating room use, anaesthetic and other additional material costs) [22]. We can speculate that when evaluating the financial variable in our cohort, we would have reached similar conclusions given the reduction in operative time; however, the financial aspect was not the focus of our study.

The benefit of shorter operative time, less blood loss with similar complication outcome and prognosis in DK without duroplasty is also advocated by Jeong et al [19]. The authors further observed outcomes in cranioplasty and observed no difference in GOS and complication rates.

An evaluation of cranioplasties performed was also published by Guresir et al. The authors reported that DK without a watertight closure was not associated with a higher risk of complications during cranioplasty [9]. Similar results in the evaluation of cranioplasty were also reported by our series, but in a smaller comparison group. A fact worth mentioning is the clearly longer operative time in the group without duroplasty.

The limitation of this study, apart from the retrospective evaluation, is the analysis of data from two different centres with different traditions and indication criteria. The extent of DK was modified by the findings, and the procedure was performed by multiple surgeons with different experience. Their skill and experience may influence operative time, blood loss and the outcome itself. In the evaluation of cranioplasty, the proportion of probands from the Neurosurgical Department of Liberec Hospital is significantly low.

The aim of the study was not to determine the correctness or appropriateness of the surgical technique, but to point out the possibility of its individualization according to the specific case.

Despite the limitations and inhomogeneity of the study, it may provide further information on the possibility of DK without duroplasty as a potentially safe option that is not burdened by a higher incidence of complications in terms of infection or the development of a fistula and hematoma.

 

Conclusion

In our retrospective bicentric study, there was no statistically significant higher incidence of complications (i.e. infection, fistula, hematoma) in patients with DK with duroplasty compared to DK without duroplasty. We also did not observe a higher incidence of these complications in the subsequent cranioplasty, but we did observe a statistically significant difference in the duration of the procedure.

 

Ethical aspects

The work was carried out in accordance with the Helsinki Declaration of 1975 and its revisions in 2004 and 2008. No ethics committee approval was required for the study as both were standard techniques.

 

Grant support

Supported by the Ministry of Health of the Czech Republic - RVO (FNOL, 00098892).

 

Conflict of interest

The authors declare that they have no conflict of interest in relation to the subject of the study.

 

 

Table 1: Representation of patients by sex, ABIA and diagnosis.

		Group				p
		Department of Neurosurgery, University Hospital Olomouc		Neurosurgery Department Liberec
		n	%	n	%
Gender	men	62	75,6 %	30	66,7 %	0,304
	Women	20	24,4 %	15	33,3 %
ABIA	1	7	8,5 %	10	22,2 %	0,107
	2	8	9,8 %	3	6,7 %
	3	67	81,7 %	32	71,1 %
Diagnosis	acute subdural hematoma	64	78,0 %	40	88,9 %	0,056
	intracerebral hematoma/contusion	17	20,7 %	3	6,7 %
	epidural hematoma	1	1,2 %	2	4,4 %

ABIA - American Brain Injury Association; n - number

 

 

Table 2. Results of comparison of age, GCS, operating time, GOS of the Olomouc and Liberec cohorts.

	Group										p
	Neurosurgical Clinic of the University Hospital Olomouc (n = 82)					Department of Neurosurgery Liberec (n = 45)
	median	min	max	diameter	SD	median	min	max	diameter	SD
Age	65,5	23,0	95,0	62,2	19,1	68,0	22,0	91,0	65,3	16,4	0,482
GCS	3,0	3,0	14,0	5,1	3,3	4,0	3,0	14,0	6,3	4,4	0,248
operating time	113,0	1,0	199,0	112,5	32,2	100,0	41,0	165,0	105,5	30,5	0,150
GOS	4,0	2,0	5,0	3,8	0,9	4,0	1,0	5,0	3,9	0,9	0,366

GCS - Glasgow Coma Scale; GOS - Glasgow Outcome Scale; min - minimum value; max - maximum value; SD - standard deviation

 

 

Table 3. Results of group comparison according to complications, infection, fistula, hematoma and GOS.

			Group				p
			Department of Neurosurgery, University Hospital Olomouc		Neurosurgery Department Liberec
			n	%	n	%
Complications	No		57	69,5 %	31	68,9 %	0,942
	Yes		25	30,5 %	14	31,1 %
infections		No	80	97,6 %	45	100,0 %	0,539
		Yes	2	2,4 %	0	0,0 %
liquor fistula		No	64	78,0 %	34	75,6 %	0,826
		Yes	18	22,0 %	11	24,4 %
hematoma		No	77	93,9 %	41	91,1 %	0,720
		Yes	5	6,1 %	4	8,9 %
GOS		good condition	0	0,0 %	2	4,4 %	0,366
		mild disability	8	9,8 %	2	4,4 %
		severe disability	21	25,6 %	3	6,7 %
		vegetative state	32	39,0 %	29	64,4 %
		death	21	25,6 %	9	20,0 %

GOS - Glasgow Outcome Scale; n- number

 

 

Table 4. Results of comparison of cranioplasty, complications and haematoma in the Olomouc and Liberec cohorts.

		Group				p
		Neurosurgical Clinic of the Olomouc University Hospital		Neurosurgery Department Liberec
		n	%	n	%
cranioplasty	No	38	62,3 %	31	86,1 %	0,019
	Yes	23	37,7 %	5	13,9 %
Complications	No	21	91,3 %	3	60,0 %	0,135
	Yes	2	8,7 %	2	40,0 %
hematoma	No	19	90,5 %	3	60,0 %	0,155
	Yes	2	9,5 %	2	40,0 %
infections	No	23	100,0 %	5	100,0 %
liquor fistula	No	23	100,0 %	5	100,0 %

n - number of

 

 

Table 5: Results of the comparison between the time of cranioplasty and the length of the procedure itself.

	Group										p
	Neurosurgical Clinic of Olomouc University Hospital (n = 23)					Department of Neurosurgery Liberec (n = 5)
	median	min	max	diameter	SD	median	min	max	diameter	SD
cranioplasty execution time	137,0	29,0	372,0	155,3	90,6	140,0	73,0	257,0	148,0	69,4	0,881
operating time	53,0	35,0	120,0	58,4	20,7	90,0	60,0	130,0	93,0	24,9	0,006

min - minimum value; max - maximum value; n - number; SD - standard deviation