A Retrospective Study of Complications in Cranioplasty: 7-Year Period

Abstract

Objective

To discuss the intraoperative and postoperative complications of cranioplasty and management during a 7-year period.

Method

Retrospective study of 7-year period of 63 patients including both male and female.

Results

Highest experienced complications were seizures and dural tear, i.e., 6%, followed by EDH in 3% patients, hydrocephalus and pneumocephalus combined 3%, 1.6% CSF collection and flap necrosis each. All the complications were managed successfully.

Conclusion

Complications of cranioplasty can be managed by following sound surgical principles. Serious complications like meningitis, air embolism and death are rare.

Introduction

Cranioplasty is a surgical procedure for reconstruction of a calvarial bone defect which occur secondary to decompressive craniotomy, trauma, tumor or infections [1]. Deep understanding of complications of cranioplasty is a must for surgeon; it prevents and reduces occurrence of complications. It also helps in efficient management of complications. This article focuses on discussing the various intraoperative complications and postoperative complications faced by the team and its management during a 7-year period.

Materials and Method

Seven years of experience in tertiary care setup of army hospital including 63 patients, both males and females, were taken in this study. This study was carried out at Army Hospital, Chandimandir Cantt., Panchkula (Haryana). Etiology of cranial defects was trauma, infarct, aneurysm, tumor and infection (Table 1). Minimum age was 16 yrs, and maximum age was 56 years (Table 2). Seventeen female and 46 male patients were operated for cranioplasty. Range of cranial defect varied from simple defect to complicated defect [2], (Table 3). Autologous bone harvested from abdominal pouch, stored in bone bank, titanium mesh, poly(methyl methacrylate) and rib (strip cranioplasty) was used for cranioplasty (Table 4). Various intraoperative and postoperative complications faced by our team are summarized in (Table 5, 6).

Table 1.

Etiology of craniotomy

Etiology of craniotomy	No. of patients
Neurosurgical trauma	22
Infarct	18
Aneurysm	11
Tumor	09
Infection	03

Table 2.

Age of patients

Age	No. of patients
10 years–20 years	03
20 years–30 years	14
30 years–40 years	24
40 years–50 years	14
50 years–60 years	08

Table 3.

Anatomic involvement of defect

Defect anatomy	No. of patients
Simple: involving single bone	08
Compound: involving two adjoining bone	32
Complex: involving 3 and more adjoining bone	19
Complicated: defects crossing the midline or bilateral defects	04

Ref: Sahoo NK, Rangan M, Tomar K, Bhat S. Classification of residual cranial defects and Selection of reconstruction materials. J Craniofac 2017; 28:1694–01

Table 4.

Reconstruction material used

Autologous bone harvested from abdominal pouch	23
Bone stored in bone bank	16
Titanium mesh	12
Polymethyl methacrylate	09
Rib (strip cranioplasty)	03

Table 5.

Intraoperative complications

Complication	Number of patient	Management
Button hole of flap	01	Managed by local flap
Dural tear	04	Managed by synthetic dura patch, pericranial graft and fascia lata

Table 6.

Post-operative complications

Complication	Number of patients	Time of complication after cranioplasty	Management
Hematoma	02	Within 48 h	No second surgical intervention required
CSF collection	01	01 week	Lumbar tapping
EDH (extra dural hematoma)	02	Within 24 h	Surgery to evacuate EDH
Seizures	04	Within 24 h	Medical management (dilantin sodium)
Hydrocephalus	01	Within 72 h	Managed by neurosurgeon by placing shunt in ventricles
Pneumocephalus	01	Within 72 h	Evacuation of pneumocephalus by neurosurgeon
Flap necrosis	01	05 days	Local surgical measures
Draining sinus	02	02–03 weeks	No surgical intervention required
Exposure of reconstruction material	Nil	—	—
Contour defect	01	Within 48 h	Second surgery for removing over contouring of graft
Resorption of graft	Nil	––	—
Thermal sensitivity	03	01 month	In titanium mesh cranioplasty
Temporal hollowing	01	0 2 weeks	—
Alopecia	01	01 month	—

Inclusion Criteria

In this study, we have included the complications directly related to surgery.

Exclusion Criteria

Complications related to transfusion, medications and anesthesia were excluded from this study.

Surgical Procedure

Standard procedure for cranioplasty was performed by our team. 1:1,00,000 adrenaline was injected around surgical site. Incision was selected as per cranial defect, and surgical technique was modified as per classification of defect. Care was taken to avoid injury to sagittal sinus during exposure of cranial defect. Raney clips were used for bleeding control by our team. The advantages of using Raneys clips include: (1) It controls bleeding by applying adequate pressure and without crushing the tissue. (2) They do not interfere in the surgical field. (3) Raney clip application is quick and easy.

Diploic venous oozing was easily managed with bone wax. Layer-by-layer dissection was carried out to expose the complete cranial defect; a pericranial layer was always left over the dura to prevent dural tear. Any accidental dural tear was repaired before proceeding further during elevation of cranial flap. Hemostasis was carried out. Cranial defect was reconstructed using autologous or synthetic material. Drain was placed. Surgical site was closed in layers.

Management of Complications

We did not encounter any life-threatening complications in any of our patient. Most of the complications encountered by us were managed by our team independently. Neurosurgery team was involved in management whenever indicated. The various complications, their prevention and management are as follows:

Button Hole of Flap

This complication was seen in 1 of our patient. If only skin is sutured, it will not form a hermitical seal and chances of infection at button hole are high. In case of button hole adjoining pedicled connective tissue flap was used by our team. It forms a 2-layered closure and thus reduces chances of infection.

Dural Tear

Dural tear was identified by CSF leak. Before reconstruction dural tear was repaired. In the large dural tear defect, pericranial graft, fascia lata or synthetic dura patch was used. Three cases of dural tear were repaired with pericranial graft (Fig. 1). One case was repaired with fascia lata and synthetic dura patch. All the dural tears were managed successfully. Case of dural tear repaired with fascia lata and synthetic dura patch was managed along with neurosurgeon team. Others cases of repair were managed independently.

Fig. 1.

Dural repair with pericranial flap

Damage to Venous Sinus

Use of improper drill bits may damage venous sinus. Superior sagittal sinus is located at such a position anatomically that it is more prone to damage. Possibility of air embolism is due to negative pressure within venous sinus. To avoid air embolism, reverse trendelenburg position (elevating the head) was used for repair of venous sinus damage. The damage was identified by anatomical location of bleeding and repaired with the help of neurosurgeon team. Only two cases of venous sinus damage were encountered. These cases were managed by visualization of damaged sinus. In one case, only gelfoam compression was used for hemostasis of venous sinus (Fig. 2). In another case, placing hitch stitches over gelfoam to adjacent bone was required for hemostasis. Reconstruction was carried out only after repair of damaged sinus.

Fig. 2.

Control of bleeding using gelfoam and neuropatties

Hematoma

Various studies has shown incidence of hematoma ranging from 1.65% [3] to 6.90% [4]. The incidence rate of hematoma in our study was in similar range as we encountered only two cases of hematoma which were managed without second surgical intervention. Adaptation of flap is helped by use of vacuum drain and pressure dressing. Chances of hematoma are also minimized by use of vacuum drain and pressure dressing. We removed the vacuum drain after 48 h, when the collection was restricted to the tubing.

CSF Collection

CSF is collected when there is dural breach. It is self-limiting in most of the cases. In our case series, only one case required intervention and was managed with lumbar tapping (Figs. 3 and 4).

Fig. 3.

Excessive bulge post-craniotomy due to CSF collection

Fig. 4.

Lumbar tapping to remove excess CSF collection

Extra Dural Hematoma (EDH)

In case of bleeding, hematoma can form between graft material and underlying flap. Management requires another surgery to remove hematoma. In our case series, two patients required second surgical intervention to evacuate hematoma. The patients were taking Ecosprin 75 mg OD and Clopid 75 mg OD preoperatively because of their medical condition. In spite of proper bleeding control before closure, normal INR value and changing to LMWH 48 h before surgery, the patients developed EDH (Fig. 5). On second surgical intervention, no significant cause of EDH was ascertained. There is a possibility that during extubation due to increase in BP, clot got dislodged resulting in bleeding and leading to formation of EDH (Fig. 6). In both cases, reconstructive material was removed and cranioplasty postponed for 3 months.

Fig. 5.

EDH (post-cranioplasty)

Fig. 6.

Evacuation of EDH in same patient

Seizure (intraoperative and postoperative)

Seizure occurs in around 14% cases of cranioplasty [3, 4]. Intraoperative and postoperative seizure is a complication of cranioplasty due to hyperactivity of brain. In this study, four patients developed postoperative seizures. Postoperative CT was done in both cases, which was normal. Postoperative seizure was managed by parenteral dilantin. Final concentration of dilantin was kept no less than 5 mg/ml with dilution in normal saline.

Hydrocephalus

It is accumulation of fluid in the brain which causes enlargement of brain and brain damage. According to Zanaty et al. [4], the rate of hydrocephalus formation after cranioplasty is around 13%. One patient in our case series developed hydrocephalus postoperatively. It was diagnosed during postoperative CT. This complication was managed by neurosurgeon by a shunt insertion surgically into ventricles to drain excess fluid.

Pneumocephalus

It is accumulation of air in the brain causing brain enlargement and brain damage. If size of pneumocephalus is large, it requires surgical intervention for evacuation. One patient in our case series developed pneumocephalus postoperatively (Figs. 7 and 8). This complication was managed by neurosurgeon by surgically evacuating the air and obliteration of dead space.

Fig. 7.

Axial view of CT showing pneumocephalus

Fig. 8.

Evacuation of pneumocephalus in same patient

Flap Necrosis

The strip of soft tissue which is parallel to the previous suture line has a compromised vascularity. Necrosis of the flap can occur due to this compromised vascularity. One patient developed flap necrosis. It was managed by antibiotics and local surgical measures (Fig. 9). The outcome was successful. Flap necrosis can be prevented by following surgical principles of maintaining adequate blood supply to the flap.

Fig. 9.

Aspiration of exudate in case of postoperative infection case

Draining Sinus

Infection of skin, folliculitis, wick effect of suture material and infection of fixation and reconstruction material can result in draining sinus. Removal of infected suture and fixation device along with local wound care are used for sinus healing. Sensitivity test was done for antibiotic. Appropriate antibiotic was used. If draining sinus do not heal after all these measure, reconstruction material is removed. In our case series, two patients who developed draining sinus were managed successfully without surgical intervention. In one patient, source of infection was wick effect of suture material.

Exposure of Reconstruction Material

Wound dehiscence, necrosis of flap, infection of graft or implant may result in exposure of reconstruction material. It occurs due to wound dehiscence, flap necrosis and infection of graft/implant. Metallic mesh has sharp margins which if not rounded, may puncture through the soft tissue and get exposed. In our case series, there was no exposure of reconstruction material in any of the patient.

Contour Defect

Contour defect can be irregular contour, loss of contour and over contour. Loss of contour is because of resorption of the graft. We encounter over contouring in 1 of our patient (Figs. 10 and 11). It was managed by removing over contouring of graft in second surgery.

Fig. 10.

Contour defect due to large implant size

Fig. 11.

Patient after correction of contour defect

Temporal Hollowing

After neurosurgical intervention, temporalis muscle and fat atrophy take place. This results in postoperative temporal hollowing. Dissection of the temporalis muscle is done. After that, bony defects of the temporal fosse are exposed. To minimize the hollowing effect, temporalis muscle is transfixed to the reconstruction material with 2–0 silk. In our case series, significant temporal hollowing was noticed in 1 of our patient.

Alopecia

In the scar tissue and along the line of incision, loss of hair is seen. To minimize damage to the hair follicles, electrocautery should be judiciously used. In our case series, in 1 patient we could notice significant alopecia.

Discussion

Nature of the initial underlying pathology, type of the reconstruction material and the technique of the cranioplasty procedure are significant factors for complications of cranioplasty [3, 5–13]. Cranioplasty is a time honored and fairly straight forward procedure; however, various studies report relatively high complication rate [14–18]. Medical condition of the patient, recipient site and selection of reconstruction material are the major factors for complications. Diabetes, asthma, chronic infection, blood dyscrasia and malignancy compromise the immunity of the host [19]. The surgical complication is increased by any underlying medical condition [20] and before surgery; clearance should be obtained from treating physician. Grant and Norcoss first gave the term Syndrome of Trephine [21]. Ashayeri et al., in his study, concluded that there is significant improvement in patients with syndrome of trephine following cranioplasty and patients suffering from coronary artery disease and on anticoagulant therapy are at high surgical risk after cranioplasty [22]. In our study, two patients who developed postoperative EDH were medically compromised and were on antiplatelet therapy. The overall complication rates reported may be as high as 36.5% in cranioplasties after decompressive craniotomies [19, 23, 24]. According to some studies, cranioplasty can be performed as early as 1 month of trauma and it does not increase the risk of complication except in bifrontal cranioplasties [25]. The incidence of surgery-associated complications was significantly reduced in patients < 40 years of age who were operated for reimplantation of bone flap within 3 months of decompressive cranioplasty as per Chang et al. [26]. As per Beauchamp et al. [27], complication in cranioplasty is not related to the time of cranioplasty. Cranioplasty can be done as early as 2 weeks following craniectomy to lower overall cost. We followed cranioplasty after 6 months of craniectomy. Postoperative complications can be classified as early and late. Complications that occur within 3 weeks of surgery are early complication and beyond that is late complication. The most common early postoperative complications are infection and wound break down. According to Gooch et al. [19], incidence of immediate postoperative complications like infection, wound breakdown, intracranial hemorrhage, bone resorption and sunken cranioplasty can be as high as 34%. Complication also depends on duration of the surgery. For fewer surgery-associated infections, operating time < 200 min is considered as a prognostic factor [28]. According to Ozaki and Buchman, the resorption rate of the bone graft is determined by its microarchitecture rather than its embryologic origin. In pediatric patients, high incidence of autogenous bone resorption was seen when reconstruction was done following Decompression Cranioplasty [16]. High incidence of autogenous bone resorption was related to the size of defect. Age, sex, anatomical location, presence of shunt and time interval had no correlation with complications.

Conclusion

Complications of cranioplasty can be managed by following sound surgical principles. Serious complications like meningitis, air embolism and death are rare.