Vascularized bone flap for anterior skull base reconstruction

Summary A case is reported where a vascularized outer-table of the frontal bone was successfully used to reconstruct a large defect in the anterior skull base following excision of a massive olfactory groove meningioma extending into the ethmoid sinuses. The flap provided a firm barrier between the cranial cavity and paranasal air sinuses, as the dural and bony integrity of the base was compromised after the radical resection of the tumour. It appears that such a flap can be effectively used for skull base reconstruction.     

Primary dural closure and anterior cranial base reconstruction using pericranial and nasoseptal multi-layered flaps in endoscopic-assisted skull base surgery

Introduction

Dural and anterior cranial base reconstruction is essential in the surgical resection of a craniofacial tumor that extends from the paranasal sinuses to the subdural space. Watertight reconstruction of vascularized tissue is essential to prevent postoperative liquorrhea, especially under conditions that prevent wound healing (e.g., postoperative irradiation therapy).

Method

We successfully treated two cases of olfactory neuroblastoma by endoscopic-assisted craniotomy with primary dural closure and anterior cranial base reconstruction using a multi-layered flap technique. Dural defects were closed using temporal fascia or fascia lata in a conventional fashion, immediately after detaching the subdural tumor, in order to isolate and prevent contamination of subdural components and cerebrospinal fluid (CSF) from the tumor and nasal sinuses. Tumor removal and anterior cranial base reconstruction were performed without any concern of CSF contamination after dural closure by craniotomy and endoscopic endonasal approach (EEA). Vascularized pericranial flaps (PCF) and nasoseptal flaps (NSF) were used simultaneously as doubled-over layers for reconstruction.

Results

The tumor was completely removed macroscopically and the anterior cranial base was reconstructed in both cases. CSF leak and postoperative meningitis were absent. Postoperative and irradiation therapy courses were successful and uneventful.

Conclusions

This multi-layered anterior cranial base reconstruction consisted of three layers: a fascia for dural plasty and double-layered PCF and NSF. This surgical reconstruction technique is suitable to treat craniofacial tumors extending into the subdural space through the anterior cranial base dura mater.     

Use of modified pericranial flaps in anterior skull base reconstruction: technical note

Proper reconstruction of the cranial base is imperative in preventing cerebrospinal fluid leakage and in the protection of vascular elements. Living pericranial flaps are often key elements in such reconstruction; however, trauma, previous surgery, or pathologic involvement can result in the loss of important parts of the pericranium. Techniques for utilizing pericranial flaps despite defects in the pericranium are described and case examples are given to illustrate these techniques.     

Nasal reconstruction in surgery of the anterior skull base.

OBJECTIVES: We sought to evaluate the effectiveness of a number of surgical maneuvers in nasal reconstruction of a diverse population of patients undergoing skull base surgery.Study design We conducted a retrospective review of a cohort of patients undergoing nasal reconstruction during surgery of the anterior skull base and craniovertebral junction. METHODS: All patients undergoing skull base surgery and nasal reconstruction by the senior author (Y.D.) with a minimum follow-up of 12 months from 1997 to 2001 were evaluated. Preoperative and postoperative photographs and clinical evaluation were examined in detail with particular attention focused on the nasal complex. RESULTS: A total of 47 patients were evaluated for this study, including those who had undergone anterior craniofacial resections (n = 14), Le Fort osteotomies (n = 5), subcranial approaches (n = 10), maxillotomies (n = 8), and midfacial disassemblies (n = 10). Primary calvarial bone graft reconstruction of the anterior craniofacial group was facilitated with the use of positioning plates and resuspension of the upper lateral cartilages when available. In contradistinction to secondary bone grafting, dorsal grafts in this group extended to the native nasal bone length. A small overlay bone graft was thought to be necessary when the nasal root was osteotomized in conjunction with the orbital and/or maxillary segments to maintain dorsal height in the long term. Le Fort osteotomy patients require refixation of the septum to the anterior nasal spine region for stability. CONCLUSIONS: Use of the techniques outlined in this article appears to be associated with gratifying long-term nasal form in reconstruction of the anterior skull base.     

Extended subgaleal fascia — Pericranial temporalis flap for skull base reconstruction

Summary An extended subgaleal fascia pericranial flap based on the temporalis muscle is described. The flap receives its vascular nourishment from the arteries supplying the temporalis muscle and from the superficial temporal artery. The long length of the flap and the ease of its rotation was used effectively to close anterior skull basel defects.     

The versatile extended pericranial flap for closure of skull base defects

OBJECTIVE: We sought to demonstrate the technical aspects of the extended pericranial flap and its versatility in reconstruction of a variety of skull base defects. STUDY DESIGN: We conducted a retrospective chart review of 32 patients who underwent reconstruction of skull-base defects with an extended pericranial flap by the senior author (Y.D.) from September 1997 to July 2003. METHODS: Patients with skull base defects after trauma or extirpative surgery were reconstructed with either a lateral- or an anterior-based vascularized extended pericranial flap. Variables and outcomes measured included: the size and anatomical location of the defect, need for other flaps, preoperative and/or postoperative radiation therapy and/or chemotherapy, bone flap necrosis, hardware exposure, wound dehiscence, postoperative cerebrospinal fluid (CSF) leak, and meningitis. RESULTS: There was no evidence of flap failure, 2 cases of transient (3 to 4 days) CSF leak without resultant meningitis, 3 patients with hardware exposure, and 2 patients with hydroxyapatite infection. The 2 transient cases of CSF leak both resolved without further surgical intervention or the placement of a lumbar drain. CONCLUSION: Both the lateral and anteriorly based extended pericranial flaps are reliable and versatile flaps associated with minimal morbidity and a low rate of complications when used to reconstruct defects of the anterolateral skull base.     

Role of bone graft in reconstruction of skull base defect: is a bone graft necessary

Ten patients underwent reconstruction of skull base defects between 1989 and 1992. In this series, the maximum size of the skull base defect was 6 x 5 cm. Three patients underwent bone grafts to reinforce the skull base. The postoperative course of seven patients without bone grafts was uneventful. There was no cerebrospinal fluid leakage, meningitis, extradural abscess, on brain herniation. On the other hand, two of the three patients with bone grafts developed extradural abseesses requiring the bone grafts to be removed. Although the number of patients in this series is not large, this study demonstrates that the use of bone grafts in reconstruction of skull base detects could be one of the factors in increasing the chances of infectious complications. We think that a bone graft is not necessary to reconstruct moderate-sized skull base defects.     

Efficacy of temporal musculopericranial flap for reconstruction of the anterior base of the skull.

Since March 1988 the temporal musculopericranial (TMP) flap has been used as our flap of choice to reconstruct defects of the anterior base of the skull that are larger than 2 x 3 cm, including the dura mater, in 33 patients. The primary diseases were malignant head and neck tumours (n = 16), trauma (n = 15), meningioma (n = 1), and teratoma (n = 1). The dura mater was reconstructed with a unilateral TMP flap, after which the cranial and nasal cavities were closed with the opposite TMP flap. In addition, bone was grafted by sandwiching the bone between the two flaps and fixing it to the surrounding residual bone. When a large area was resected, making it impossible to use a TMP flap, a frontal musculopericranial (FMP) flap or a free flap (usually the rectus abdominis myocutaneous flap) was used to close the cranial and nasal cavities. Thirty of the 33 patients recovered with no postoperative complications. Two patients developed extradural abscesses in the anterior base of the skull and one developed mild meningitis, but they were successfully treated conservatively. When bilateral TMP flaps were used for the reconstruction, no patient had aesthetic problems in the forehead region. The TMP flap is extremely effective for the reconstruction of the anterior base of the skull because it is minimally invasive and causes few aesthetic problems in the forehead region.     

Free tissue transfer and local flap complications in anterior and anterolateral skull base surgery

BACKGROUND: Advances in reconstructive techniques over the past two decades have allowed the resection of more extensive skull base tumors than had previously been possible. Despite this progress, complications related to these cases remain a concern. METHODS: Univariate and multivariate analyses were used to determine the relationship of host, tumor, defect, treatment, and reconstructive variables to wound and systemic complications after anterior and anterolateral skull base resections. The study included 67 patients receiving local flap (LF) or free tissue transfer (FTT) reconstructions during an 8-year period. RESULTS: Overall, 28% of patients had a major wound complication, and 19% had a major systemic complication. LF and FTT flaps had similar rates of wound complications. LF reconstructions were associated with late wound breakdown problems, and FTT flap complications were primarily acute surgery-related problems. CONCLUSIONS: The surgical reconstruction of skull base defects should be planned on the basis of the ability of the technique to attain safe closure and maintain integrity after radiation therapy.     

Free latissimus dorsi flap for reconstruction of the anterior base of the skull

Defects resulting after resection of malignant tumors of the paranasal sinuses involving the anterior base of the skull need an adequate closure. In addition to such avital tissue as fascia lata, fat, or ceramics, in recent years we used free muscle flaps from the latissimus dorsi for reconstruction. We performed this reconstructive method in seven patients after radical tumor ##. The operation was performed in cooperation with the neurosurgeon. In three cases a transfrontal in combination with a transfacial approach was used and in four cases only a transfacial approach was chosen. The flap was tailored as a pure muscle transplant if only the base of the skull had to be repaired and the surgical cavity had to be obhiterated. In three cases a skin paddle was left on the muscle to perform a closure of the orbit and the hard palate. In four patients we performed primary reconstruction, in three cases secondary reconstruction, which was necessary because cerebrospinal fluid (CSF) leakage occurred after primary reconstruction with avital tissue in addition to insufficient pericranial flap. None of the patients with primary reconstruction developed CSF leakage. There was no free flap failure. The aim of this reconstruction is a safe closure of skull base defects to prevent infection, meningitis, brain abscess, and brain herniation.     

Complications of anterior skull base surgery

The complications associated with anterior skull base surgery were reviewed in 49 consecutive patients treated between November 1986 and August 1993. All procedures involved a combined otolaryngologic and neurosurgical approach, and the senior otolaryngologist was the same. Fifty-two procedures were completed; 37 for malignant disease and 15 for benign disease. Twenty-one of the 52 procedures had postoperative complications, a 40% complication rate. One postoperative death occurred from a myocardial infarction, for a 2% mortality rate. Infections complications were the most common, occurring in 19% of cases. The one case of meningitis responded to antibiotic therapy, without neurologic sequelae. Seven cerebrospinal fluid leaks occurred (13%); five resolved with conservative management, and two required reoperation. There was no significant difference between complication rates for patients with previous craniotomy, radiation therapy, or chemotherany compared with those with no prior therapy (p > .05). More complications occurred in patients with malignant disease than in those with benign disease (46% vs 27%), but this was not statistically significant (p > .05). Anterior and anterolateral skull base resection as part of a multidisciplinary approach to diseases of this region may provide improved palliation and may offer possible improved survival with acceptable surgical mortality. Although only 6% of patients were left with permanent neurologic sequelse in this series, the risks of serious complications are considerable.     

Overlapping free bone graft with galea-pericranium in reconstruction of the anterior skull base to prevent CSF leak and sequestrum formation

Summary Background. Reconstruction of the skull base after resection of a tumour is important to prevent postoperative complications such as infectionsand cerebrospinal fluid (CSF) leakage. Several reconstructive methods of the anterior skull base have been reported but, their long-term results are not clear. Methods. We describe a technique used after removal of an olfactory neuroblastoma with infiltration of the skull base. The reconstructed dura was covered with a galeal patch, a replicated galeal-pericranial flap, a graft from the inner table of skull, and a vascularised galeal-pericranial flap placed on the skull base defect. All layers were fixed with fibrin glue. Conclusion. Three dimensional computed tomography (3D-CT) at bone window settings demonstrated the bone graft covered the bone defect and was not absorbed and after 11 years there have been no signs of tumour regrowth or complications.     

Subcranial anterior skull base dural repair with galeal frontalis flap.

The pericranial flap has been widely used to repair surgically created anterior skull base defects during craniofacial resection. This report describes a technique of subcranial dural repair with a galeal frontalis flap after resection of an ethmoidal adenoid cystic carcinoma.     

Endoscopic endonasal skull base surgery: Part 1--The midline anterior fossa skull base.

OBJECTIVE: An endonasal endoscopic surgery to the anterior fossa skull base was developed in cadaver dissection as a minimally invasive surgical technique and, subsequently, used in patient treatment. METHODS: Six cadaver head specimens were used. Ideal head positioning and various surgical routes were studied. To estimate the extent of surgical exposure provided by this technique, the width of the exposed anterior cranial fossa was measured between the medial margin of the orbits, the optic nerves and the carotid arteries. Three demonstrative patient cases are presented. RESULTS: Ideal head positioning was discovered to be at 15-degree extension of the forehead-chin line. Paraseptal, middle meatal and middle turbinectomy approaches were developed. The average width between the medial orbits was measured to be 24 mm (range 22-29 mm) at the crista galli level, 27 mm (range 24-30 mm) at the planum sphenoidale, 18 mm (range 15-22 mm) between the optic nerves, and 17 mm (range 13-21 mm) between the rostral carotid siphons. This technique, when it was applied in patient care, proved to be minimally invasive. CONCLUSIONS: This endoscopic endonasal approach provided a direct "short-cut" access to the midline anterior fossa skull base. This technique can be used for the surgical treatment of cerebrospinal fluid (CSF) leak, meningiomas, craniopharyngiomas, pituitary adenomas, and other midline intracranial anterior skull base lesions. This is the first report in the English literature describing endonasal endoscopy for the surgical treatment of primary intracranial anterior fossa skull base lesions.     

Advances in endoscopic sinonasal and anterior skull base surgery

Endoscopic transnasal surgery is rapidly replacing more radical external 'open' procedures. At Groote Schuur Hospital, Cape Town, we performed 94 advanced endoscopic sinonasal and anterior skull base procedures over a 2-year period. Most of these would previously have been performed using large external incisions requiring more invasive surgery with significantly higher morbidity. Endoscopic surgery is more cost-effective than open procedures because it reduces duration of hospitalisation, operating time and theatre consumables and obviates the need for postoperative intensive care unit admission.We have had no complications other than 2 cerebrospinal fluid leaks, but the potential risks of endoscopic sinonasal and skull base surgery are significant and proper training is required.     

Microvascular free flap reconstruction of skull base penetrating tumors

This is a follow-up study of 31 consecutive patients who underwent skull base tumor resection and microvascular tissue reconstruction in anterior and middle cranial fossa. Parameters recorded included factors related to operation, hospital stay, and outcome. All patients had a minimum follow-up of 5 years. There were no flap losses and no reoperations due to anastomoses-related complications. Five of 30 patients had cerebrospinal fluid leak that resolved with spinal drain except in one case, where the flap was placed incorrectly and the patient died of meningitis. Two other patients died due to early complications of the surgery. Although the complication rate was quite high, we consider this type of surgery worth performing, and even palliative surgery is to be considered in selective cases. Rectus abdominis flap due to its pliability and long pedicle proved to be most suitable flap together with superficial temporal artery and vein as recipient vessels.     

Free rectus abdominis muscle reconstruction of the anterior skull base.

Pericranial flaps and galeal frontalis myofascial flaps can be useful for separating the cranial space from the paranasal sinuses and the nasopharynx, but they cannot provide reliable separation and protection of the brain from bacterial flora of the upper airway in patients who previously have received high dose radiation therapy and undergone craniotomy, or required extensive resection of the cranial base. The free rectus abdominis muscle flap, on the other hand, can provide a good alternative for reconstruction of the anterior skull base in such difficult cases, and give good results. In six cases using free rectus abdominis flaps, there have been neither cerebrospinal fluid leaks nor meningitis. There was one flap failure due to venous congestion.