Reconstruction Of Cranial Defects Research Articles

Decreased Rate of CSF Leakage Associated with Complete Reconstruction of Suboccipital Cranial Defects

Background Cerebrospinal fluid (CSF) leakage represents a major source of morbidity following microvascular decompression (MVD) surgery. The objective of this study was to retrospectively assess whether complete versus incomplete reconstruction of the suboccipital cranial defect influences the incidence of CSF leakage following MVD. Methods We reviewed the charts of 100 patients who consecutively underwent MVD for trigeminal neuralgia by two attending neurosurgeons between July 2004 and April 2010. Operative variables including incomplete or complete calvarial reconstruction, primary dural closure or dural closure with adjunct, and use of lumbar drainage were recorded. The effect of complete calvarial reconstruction on the incidence of postoperative CSF leakage was examined using a multivariate logistic regression model. Results Of the 36 patients whose wound closure was reconstructed with a complete cranioplasty, 2 (5.6%) patients experienced a postoperative CSF leak. Of the 64 patients whose wound closure was augmented with an incomplete cranioplasty, 15 (23.4%) experienced a postoperative CSF leak. There was suggestive but inconclusive evidence that the risk of CSF leakage following MVD was smaller with complete reconstruction of calvarial defect than with incomplete reconstruction (two-sided p value = 0.059), after accounting for age, dural closure method, use of lumbar drainage, and previous MVD. Conclusion Complete reconstruction of the suboccipital cranial defect decreases the risk of CSF leakage.

Reconstruction of Cranial Defects with Individually Formed Cranial Prostheses Made of Polypropylene Polyester Knitwear: An Analysis of 48 Consecutive Patients

This article presents a new method of cranioplasty in which polypropylene polyester knitwear was used as the filling material. The basis for prosthesis shaping was a three-dimensional model of the defect made according to the patient's CT scans. Previously, such material has never been a subject of computer-aided design and computer-aided manufacturing (CAD/CAM) individual forming. The process of the prosthesis design included CT bone scans and mold preparation for each patient. Such prostheses were implanted in 48 patients with cranial defects. The total number of prostheses applied was 51. The follow-up time was at least 6 months up to 36 months. The group of treated patients is described here, and sample pictures are shown to illustrate the results. The smallest defect had a size of 15 cm(2); the biggest, 178 cm(2). The coverage and the aesthetic results were very good in all cases. Two patients had postoperative complications. The cranioplastic solution described here is a valuable addition to the existing reconstructive methods, because of the low cost of the implant, the ease of its adjustment to the shape of the defect, and the short time of preparation.

Cerebrospinal fluid volume replacement following large endoscopic anterior cranial base resection

Large endoscopic skull-base resections often result in extensive postoperative pneumocephalus secondary to copious evacuation of cerebrospinal fluid (CSF) during the procedures. Replacing CSF lost during craniotomy with saline is a common technique in neurosurgery, but is difficult after extensive transnasal resection of the anterior cranial base because direct transnasal CSF augmentation will escape until the skull base reconstruction is sealed. The present study evaluated the effectiveness of intraoperative CSF volume replacement via lumbar drains on improving postoperative outcomes. Ten large endoscopic anterior skull-base resections (>2.5 cm) were performed from 2008 to 2011. Sellar, parasellar, and transplanum resections were excluded. Etiologies included esthesioneuroblastoma (2), squamous cell carcinoma (2), intracranial dermoid (2), adenocarcinoma (1), adenoid cystic carcinoma (1), melanoma (1), and meningioma (1). Six patients were administered preservative-free normal saline via lumbar drain during skull-base reconstruction. Data collected included volume of postoperative pneumocephalus, intravenous pain medicine requirements 24 hours after surgery, and length of hospital stay. Volume of pneumocephalus (4.78 cm vs 12.8 cm(3) , p = 0.04) and length of hospital stay (2.17 days vs 8.5 days, p = 0.03) were significantly decreased in the normal saline volume replacement group. Average intravenous pain medication requirements were reduced in the first 24 hours postoperatively (8 mg morphine vs 14 mg morphine, p = 0.25), but did not reach statistical significance. Evacuation of intracranial air by transthecal administration of saline during reconstruction of large anterior cranial base defects was an effective technique to decrease postoperative pneumocephalus and length of hospital stay. Further evaluation is warranted.

Customized Cranioplasty Implants Using Three-Dimensional Printers and Polymethyl-Methacrylate Casting

ObjectiveThe prefabrication of customized cranioplastic implants has been introduced to overcome the difficulties of intra-operative implant molding. The authors present a new technique, which consists of the prefabrication of implant molds using three-dimensional (3D) printers and polymethyl-methacrylate (PMMA) casting.MethodsA total of 16 patients with large skull defects (>100 cm2) underwent cranioplasty between November 2009 and April 2011. For unilateral cranial defects, 3D images of the skull were obtained from preoperative axial 1-mm spiral computed tomography (CT) scans. The image of the implant was generated by a digital subtraction mirror-imaging process using the normal side of the cranium as a model. For bilateral cranial defects, precraniectomy routine spiral CT scan data were merged with postcraniectomy 3D CT images following a smoothing process. Prefabrication of the mold was performed by the 3D printer. Intraoperatively, the PMMA implant was created with the prefabricated mold, and fit into the cranial defect.ResultsThe median operation time was 184.36±26.07 minutes. Postoperative CT scans showed excellent restoration of the symmetrical contours and curvature of the cranium in all cases. The median follow-up period was 23 months (range, 14-28 months). Postoperative infection was developed in one case (6.2%) who had an open wound defect previously.ConclusionCustomized cranioplasty PMMA implants using 3D printer may be a useful technique for the reconstruction of various cranial defects.

Use of acrylic bone cement for reconstruction of cranial bone defects

Use of acrylic bone cement for reconstruction of cranial bone defects

Simultaneous repair of two large cranial defects using rapid prototyping and custom computer-designed titanium plates: a case report

Custom titanium cranioplasty plates, manufactured by a variety of techniques, have been used to repair a range of cranial defects. The authors present a case where two relatively large, adjacent cranial defects were repaired by custom computer-designed titanium plates. The two plates were designed and fabricated simultaneously using a unique methodology. A 28-year-old woman underwent a corpus callosotomy for medically intractable epilepsy. The surgery was complicated by unexpected haemorrhage which necessitated a second craniotomy. Subsequent deep infection required the removal of bilateral bone flaps, presenting a challenge in the reconstruction of extensive, bilateral but asymmetrical cranial defects. The patient underwent a head computed tomography scan, from which a rapid-prototype model of the skull was produced. The surfaces for the missing cranial segments were generated virtually using a combination of software products and two titanium plates that followed these virtual contours were manufactured to cover the defects. The cranioplasty procedure to implant both titanium cranial plates was performed efficiently with no intra-operative complications. Intra-operatively, an excellent fit was achieved. The careful planning of the plates enhanced the relative ease with which the cranial defects were repaired with an excellent cosmetic outcome.

Reconstruction of Cranial Bone Defects Using Struthio camelus Eggshell

There are many synthetic materials for the treatment of bone defects, which have their own advantages and disadvantages. We aimed to compare the efficacy of ostrich eggshell, which is cheap and easily available, and demineralized bone matrix in healing of cranial bone defects. A full-thickness circular bone defect was created in the frontal bone of 40 Wistar rats. Group 1 was the operative control group. In group 2, demineralized bone matrix applied into the defects; in group 3, Struthio camelus (ostrich) eggshell implants (OSIs) were applied into the defects; and in group 4, ostrich eggshell powders were applied into the defects. Computed tomographic analysis was performed to evaluate the healing of bone defects, the bone density, the OSI area measurements, and the OSI volume and density. At the end of the 24th week, all rats were killed. New bone formation, infection, resorption, and tissue reactions were evaluated. Ostrich eggshell implants were slightly resorbed, integrated with bone, stable, and supplied good cranial completeness. Ostrich eggshell powders were totally resorbed at the sixth month. There were no significant differences between control and ostrich eggshell groups in new bone formation. Ostrich eggshell did not seem to be an osteoproductive material, but it has some important advantages as an implant. Ostrich eggshell has a strong structure, is cheap, is shaped easily, and does not cause tissue reaction or infection. Ostrich eggshell could be a good alternative graft material for craniomaxillofacial procedures. Further studies are required to find out the potential use of the ostrich eggshell in craniomaxillofacial reconstructions.

Cranioplasty With Adipose-Derived Stem Cells and Biomaterial: A Novel Method for Cranial Reconstruction

There is no optimal method for reconstruction of large calvarial defects. Because of the limitations of autologous bone grafts and alloplastic materials, new methods for performing cranioplasties are needed. To create autologous bone to repair cranial defects. We performed a cranioplasty procedure with this new method in 4 patients who had large calvarial defects of different etiologies. We used autologous adipose-derived stem cells seeded in beta-tricalcium phosphate granules. For 2 patients, we used a bilaminate technique with resorbable mesh. During follow-up, there were no clinically relevant postoperative complications. The computed tomography scans revealed satisfactory outcome in ossification, and in the clinical examinations, the outcomes were good. The cranioplasty was measured in Hounsfield units from each computed tomography scan. The Hounsfield units increased gradually to equal the value of bone. The combination of scaffold material such as beta-tricalcium phosphate and autologous adipose-derived stem cells constitutes a promising model for reconstruction of human large cranial defects. The success of these clinical cases paves way for further studies and clinical applications to turn this method into a reliable treatment regimen.

Warfare-Related Craniectomy Defect Reconstruction: Early Success Using Custom Alloplast Implants

Cranial bone defects secondary to decompression craniectomy associated with the Global War on Terror pose a unique reconstructive challenge. The objective of this study was to evaluate the outcome of alloplastic reconstruction using custom-designed implants for large craniectomy defects from warfare-related cranial trauma. A review of injured personnel who underwent decompression craniectomy reconstruction and subsequent alloplastic cranial reconstruction in the National Capital Region was performed from 2003 to 2008 (n = 99). Collected data included mechanism of injury, evacuation time, Glasgow Coma Scale score, decompression craniectomy type, and implant type. Outcomes included complications and retention of implants. Average patient age was 25 years (range, 18 to 53 years). All patients were men. Follow-up was 2.4 years. Improvised explosive device blasts were responsible for 46 percent of injuries. The initial Glasgow Coma Scale score was 7. On arrival to the continental United States, it was 9. Time for evacuation to the continental United States was 6 days. Eighty-eight percent had hemicraniectomies and 12 percent had bifrontal craniectomies. Successful reconstruction with retention of the implant occurred in 95 percent. Five (three hemicraniectomy and two bifrontal) patients underwent implant removal because of infection. Seventy-three patients were complication-free. The reoperation rate with recontouring, drainage, or removal was 18 percent. After reconstruction, seven patients developed hematomas/hygromas, three patients developed seizures, and 10 percent had contour abnormalities (temporal hollowing) requiring revisions. Despite war wound contamination, massive cranial defects can be successfully reconstructed using custom alloplastic implants. However, reconstruction of frontal cranial defects in proximity to the airways and orbits was associated with infection and implant removal.

Three-dimensional reconstruction of cranial defect using active contour model and image registration

In neurosurgery, cranial incisions during craniotomy can be recovered by cranioplasty--a surgical operation using cranial implants to repair skull defects. However, surgeons often encounter difficulties when grafting prefabricated cranial plates into defective areas, since a perfect match to the cranial incision is difficult to achieve. Previous studies using mirroring technique, surface interpolation, or deformed template had limitations in skull reconstruction to match the patient's original appearance. For this study, we utilized low-resolution and high-resolution computed tomography images from the patient to repair skull defects, whilst preserving the original shape. Since the accuracy of skull reconstruction was associated with the partial volume effects in the low-resolution images and the percentage of the skull defect in the high-resolution images, the low-resolution images with intact skull were resampled and thresholded followed by active contour model to suppress partial volume artifacts. The resulting low-resolution images were registered with the high-resolution ones, which exhibited different percentages of cranial defect, to extract the incised cranial part. Finally, mesh smoothing refined the three-dimensional model of the cranial defect. Simulation results indicate that the reconstruction was 93.94% accurate for a 20% skull material removal, and 97.76% accurate for 40% skull material removal. Experimental results demonstrate that the proposed algorithm effectively creates a customized implant, which can readily be used in cranioplasty.

Clinical application and outcome of the internal mammary artery perforator (IMAP) free flap for soft tissue reconstructions of the upper head and neck region in three patients

The fasciocutaneous internal mammary artery perforator (IMAP) island flap allows for superior esthetical and functional skin cover in the head and neck region in combination with limited donor site morbidity. Its modification as a free flap allows reconstruction of more cranial defects. Three IMAP free flaps varying from 7 × 4 cm² to 10 × 6 cm² were transplanted in three patients with a mean age of 59 years (range, 54-69 years). Enhancement of the flap's vascular pedicle at least doubles the diameter of the internal mammary vessels to be anastomosed. Coverage with excellent texture and color match was uneventfully obtained and the flaps' donor sites were primarily closed in all three cases. Our experience proves the consistent feasibility of successful transplantation of the IMAP free flap. Because of its characteristics, we suggest contemplating the use of this flap in the upper head and neck region.

Microvascular Reconstruction of Composite Cranial Defects

Microvascular reconstruction of composite cranium defects is challenging, and operative planning differs in various anatomic regions of the cranium. The aim of this article is to detail surgical strategies for microvascular reconstruction in different areas of the cranium. Fifty-eight free tissue transfers were performed in 54 patients with composite cranial defects between 1995 and 2009. The cranium was divided into six zones to classify the defects. Data on patient demographics, location and cause of the defects, technical details of surgical management, and complications were analyzed. Defects were secondary to ablative procedures in 45 patients. Eight patients had posttraumatic defects, and one patient had congenital defect. Nine different flap types were used in the series. Choice of recipient vessels and the use of interpositional vein grafts varied according to the site of the cranial defects. Microsurgical reconstruction of cranial defects can be performed safely with predictable outcome by methodic assessment of the problem and by careful attention to the details of the reconstructive plan. In this article, valid conclusions on the planning of microvascular reconstruction in different areas of the cranium have been determined.

Reconstruction of Large Cranial Defect with Alloplastic Material (Bone Cement-Cold Cure Polymethyl-Methacrylate Resin)

A 40-years-old male patient reported to our department with a chief complaint of persistent palatal fluid discharge and large depressed forehead defect. He gave a history of trauma 20months back due to head on collision to electric pole and underwent surgery twice for open reduction and fixation of facial skeletal fractures. After 9months of surgery again a third surgery was performed for the removal of frontal bone due to infection and osteomyelitis at the same site. Extra-oral examination revealed a large fronto-cranial defect extending from superior border of frontal bone to supra-orbital margins bilaterally in length, and from frontal right lateral to frontal left lateral side in width, measuring 8.0cm in length, 10.5cm in width and 1.5 to 2.0cm in depth. Intra-oral sinus fluid discharge was from left posterior palatal region. Preoperative CT was taken and reconstruction of fronto-cranial defect was successfully performed with bone cement. Alloplastic implant reconstruction achieved an excellent esthetic result without any complications.

3D powder printed calcium phosphate implants for reconstruction of cranial and maxillofacial defects

The aim of this study was to investigate the processing and the possible use of3Dpowder printed calcium phosphate implants for the reconstruction of cranial and maxillofacial defects. The fabrication of the implants was carried out with a commercial 3D powder printing system. Diluted phosphoric acid was printed onto tricalcium phosphate powder, leading to the formation of dicalcium phosphate dihydrate (Brushite). Hydrothermal conversion of the brushite matrices led to the formation of dicalcium phosphate anhydrous (Monetite). Bony defects were generated using a human cadaver skull. The implants were computer-aided designed (CAD) using a mirror imaging procedure following computed tomography of the skull. Specific implants were manufactured by the 3D powder printing rapid prototyping technique. The processing chain from data acquisition to printing of the implants proved to be practical and uncomplicated. The individual implants showed a high degree of accuracy of fit. Mechanical and physical investigations revealed suitable characteristics. 3D powder printing of calcium phosphate cement material provides a promising new method for the manufacturing of biodegradable synthetic patient-specific craniofacial implants.

Pericranial Flap for Endoscopic Anterior Skull-Base Reconstruction

One of the major challenges of cranial base surgery is reconstruction of the dural defect and prevention of postoperative cerebrospinal fluid (CSF) fistula. The introduction of endoscopic techniques and an endonasal approach to the ventral skull base has created new challenges for reconstruction. We have developed an endoscopic pericranial flap (PCF) for skull base reconstruction and hereby present the initial cohort of patients who had endonasal reconstruction with a PCF after endoscopic skull base resection. We also demonstrate a method to radiographically incorporate anticipated skull base defects for preoperative planning of PCF length. Dural defects after endonasal skull base resection of invasive tumors were reconstructed with an onlay PCF (n = 10). We performed radiological studies to assist preoperative planning for where to make incisions while harvesting a PCF for anterior skull base, sellar, and clival defects. Each of the 10 patients had excellent healing of their skull base and had no evidence of any postoperative cerebrospinal fluid leaks. Eight patients had radiation therapy without flap complications. Radiographic studies demonstrate that the adequate PCF length, covering defects of the anterior skull base, sellar, and clival defects are 11.31 to 12.44 cm, 14.31 to 15.57 cm, and 18.5 to 20.42 cm, respectively. The PCF provides an option for endonasal reconstruction of cranial base defects and can be harvested endoscopically. Pre-operative radiographic evaluation may guide surgical planning. There is minimal donor site morbidity, and the flap provides enough surface area to cover the entire ventral skull base.

Trifocal Biplanar Distraction-Compression Osteosynthesis

Surgical treatment of calvarial defects and deformities has some drawbacks such as donor site morbidity or use of allogenic materials. In this experimental study, we presented a three-dimensional reconstruction of cranial defects by using trifocal biplanar distraction-compression osteosynthesis (TBDCO).Eight sheep with a mean age of 2 years were divided into 2 groups as the control (n = 3) and distraction groups (n = 5). All the animals were operated on under general anesthesia, and 80 x 50-mm full-thickness calvarial defects were created. In the control group, no treatment was performed. In the distraction group, TBDCO was performed with a custom-made distraction device with 2 transport segments. After 5 days of latency period, the anterior transport segment was distracted to a posterior and superior direction (0.7 and 0.3 mm, respectively) and the posterior transport segment was distracted obliquely to an anterior and superior direction (0.7 and 0.3 mm, respectively) with a resulting total vectorial movement of 0.75 mm/d. Active distraction was approximately 29 days, and the consolidation period was 60 days.No major complications were seen during the whole procedure. In the control group, the bone defects remained unhealed. In the distraction group, defects healed and the reconstructed calvarium was dome shaped. Preoperative and postoperative cranial volume measurements of the distraction group animals revealed an increase in cranial volume (P < 0.05). Histologic evaluation showed inductive bone regeneration and mature bone structure development within the distraction zone. Trifocal biplanar distraction-compression osteosynthesis is an effective and safe technique for three-dimensional closure of the cranial defects. In clinical practice, it could provide several advantages over currently available reconstructive procedures.

Comparative Evaluation of Autogenous Calvarial Bone Graft and Alloplastic Materials for Secondary Reconstruction of Cranial Defects

To do a comparative study and evaluate the outcome in healing of reconstructed cranial defects with an autogenous bone graft vis-à-vis alloplastic materials. A total of 22 patients with cranial defects were selected for this study. All the subjects were men; mean age was 27 years. Secondary reconstruction was done to obturate the defects. Of the 22 patients, 11 underwent cranioplasty with autogenous calvarial bone graft, 6 patients with a titanium mesh and 5 with a polymethylmethacrylate plate. The follow-up period ranged from 18 to 24 months. The 11 patients who were operated on with autogenous calvarial bone grafts did not develop any postoperative infection or complications. Graft uptake was complete, and the contour of the skull was improved in all the patients. Of the 5 patients operated on for secondary reconstruction with polymethylmethacrylate plates, 3 had exposure of the implant and 1 reported with secondary infection. Of the patients where secondary reconstruction was carried out with a titanium mesh only, 1 reported with secondary infection and 2 reported with thermal sensitivity. No graft resorption was detected. In our study, we concluded that autogenous calvarial bone grafts have better mechanical, biologic, and immunologic properties. This procedure allows the surgeon to reconstruct moderately large cranial defect with ease of access within single or adjacent incision to the operating site with minimal postoperative morbidity and discomfort.

Calvarial Reshaping Using Bifocal Bidirectional Transport Distraction Osteogenesis

The aim of this study is to assess 3-dimensional reconstruction of cranial defects by use of bifocal bidirectional transport distraction osteogenesis (BBTDO). This study was performed on 8 sheep, divided into a control group (n = 3) and treatment group (n = 5). Full-thickness cranial defects (50 x 40 mm) were created on calvaria. In the control group only the skin was closed. In the treatment group BBTDO was performed. Distraction was performed with a custom-made distraction device with a transport segment of 40 x 20 mm. After a 5-day period of latency, distraction was applied to the transport segment. During the first 20 days of distraction, the transport segment was distracted 1 mm in the forward direction and 0.5 mm in the upward direction. After the next 20 days of distraction, the transport segment was distracted 1 mm forward and 0.5 downward. After a total of 40 days' distraction, a 30-day consolidation period was applied. Macroscopic, radiologic (computed tomography with volume measurements), and histologic evaluations were done. No major complications were seen during the whole study period. In the control group the bone defects remained unhealed at the end of the study period. The same-sized defects in the treatment group healed with a convexity like the calvaria. Preoperative and postoperative cranial volume measurements of the treatment group animals showed an increase in cranial volume (P < .05). Histologic evaluation showed inductive bone regeneration and mature bone structure development within the distraction zone. The BBTDO is an effective and safe technique for 3-dimensional closure of cranial defects.

Bone Grafts in Craniofacial Surgery

Reconstruction of cranial and maxillofacial defects is a challenging task. The standard reconstruction method has been bone grafting. In this review, we shall describe the biological principles of bone graft healing, as pertinent to craniofacial reconstruction. Different types and sources of bone grafts will be discussed, as well as new methods of bone defect reconstruction.

Pericranial Flap for Endoscopic Anterior Skull Base Reconstruction: Clinical Outcomes and Radioanatomic Analysis of Preoperative Planning

Background One of the major challenges of cranial base surgery is reconstruction of the dural defect and prevention of postoperative cerebrospinal fluid (CSF) fistula. The introduction of endoscopic techniques and an endonasal approach to the ventral skull base has created new challenges for reconstruction. Objective We have developed an endoscopic pericranial flap (PCF) for skull base reconstruction and hereby present the initial cohort of patients who had endonasal reconstruction with a PCF after endoscopic skull base resection. We also demonstrate a method to radiographically incorporate anticipated skull base defects for preoperative planning of PCF length. Methods Dural defects after endonasal skull base resection of invasive tumors were reconstructed with an onlay PCF (n = 10). We performed radiological studies to assist preoperative planning for where to make incisions while harvesting a PCF for anterior skull base, sellar, and clival defects. Results Each of the 10 patients had excellent healing of their skull base and had no evidence of any postoperative cerebrospinal fluid leaks. Eight patients had radiation therapy without flap complications. Radiographic studies demonstrate that the adequate PCF length, covering defects of the anterior skull base, sellar, and clival defects are 11.31 to 12.44 cm, 14.31 to 15.57 cm, and 18.5 to 20.42 cm, respectively. Conclusion The PCF provides an option for endonasal reconstruction of cranial base defects and can be harvested endoscopically. Pre-operative radiographic evaluation may guide surgical planning. There is minimal donor site morbidity, and the flap provides enough surface area to cover the entire ventral skull base.