Computer Based Algorithm for Patient Specific Implants for Cranioplasty in Patients With Skull Defects (CAPSID)

Computer Based Algorithm for Patient Specific Implants for Cranioplasty in Patients With Skull Defects: a Prospective Clinical Trial

Patients with skull defects after craniotomy for example tumor resection, head trauma, stroke, need a reimplantation of the bone afterwards. For some circumstances, their own bone cannot be reimplanted due to infection, tumor infiltration, damage to the bone, or aseptic bone necrosis. In these cases a Patient Specific Implant (PSI) needs to be designed to fit into the patient's skull defect.

The design of the PSI is based on the preoperative CT-scan of the patient's head with the skull defect, the imaging data set is uploaded and processed with IPlanNet software by BrainLab®. With the help of the software, a 3D model of a negative mould of the PSI is designed and printed. In the operation room, the PSI is fabricated under sterile conditions using the PSI mould. The design of the PSI mould with the help of IPlanNet is demanding and takes some few hours depending on the complexity of the case to be designed. In certain cases the accuracy of the fabricated PSI mould is not optimal, so that the surgeon intraoperatively has to adapt for the inaccuracy to achieve the best cosmetic and functional results at the expense of the operation duration, a known risk factor for postoperative wound infection and other perioperative complications.

Therefore, the investigators have developed an automated computer-based algorithm for PSI design (CAPSID). With the help of this tool, an accurate PSI and its corresponding mould can be calculated and designed based on the preoperative CT scan of the patient within 5-15 minutes and the corresponding mould can be printed. This step is automated and thus, independent of the neurosurgeons experience and skills in 3D processing software. The mould can be used for intraoperative fabrication of the implant under sterile conditions in the common way as described above. The possible advantages of the clinical establishment of this procedure would be a higher accuracy of the PSI compared to the conventional PSI fabrication method with better cosmetic results, lower costs and faster availability and production leading to shorter waiting time for the patient, and as a consequence of the higher accuracy leading to shorter operation time, with a reduction of risk of operative adverse events for the patient. Furthermore, the proof of practicability of this new method, could lead to new concepts in the field of Computer-based Patient Specific Implants in modern medicine in general.

Study Overview

• Status: Completed
• Conditions: Stroke; Head Trauma
• Intervention / Treatment: Other: Patient Specific Implant

Detailed Description

Patients with skull defects after craniotomy for example tumor resection, head trauma, stroke, need a reimplantation of the bone afterwards. For some circumstances, their own bone cannot be reimplanted due to infection, tumor infiltration, damage to the bone, or aseptic bone necrosis. In these cases a Patient Specific Implant (PSI) needs to be designed to fit into the patient's skull defect. Several materials are currently used such as titanium, poly-ether-ether-ketone (PEEK) or poly-methylmethyl-acrylate (PMMA) for PSI fabrication. At the moment, PSI are commercially available from different companies (DePuy Synthes®, EOS®, Xilloc®). Apart from the high costs of commercially available PSI, it takes usually several weeks until the designed and manufactured PSI is delivered to the hospital ready for reimplantation.

On the other hand, a method for software-based PSI design and intraoperative fabrication of the PSI under sterile conditions was described by Stieglitz et al. This method is currently used in everyday clinics in the department of neurosurgery in Bern. In short summary, the design of the PSI is based on the preoperative CT-scan of the patient's head with the skull defect, the imaging data set is uploaded and processed with IPlanNet software by BrainLab®. With the help of the software, a 3D model of a negative mould of the PSI is designed and printed. In the operation room, the PSI is fabricated under sterile conditions using the PSI mould. The design of the PSI mould with the help of IPlanNet is demanding and takes some few hours depending on the complexity of the case to be designed. In certain cases the accuracy of the fabricated PSI mould is not optimal, so that the surgeon intraoperatively has to adapt for the inaccuracy to achieve the best cosmetic and functional results at the expense of the operation duration, a known risk factor for postoperative wound infection and other perioperative complications.

Therefore, the investigators have developed an automated computer-based algorithm for PSI design (CAPSID). With the help of this tool, an accurate PSI and its corresponding mould can be calculated and designed based on the preoperative CT scan of the patient within 5-15 minutes and the corresponding mould can be printed. This step is automated and thus, independent of the neurosurgeons experience and skills in 3D processing software. The mould can be used for intraoperative fabrication of the implant under sterile conditions in the common way as described above. The possible advantages of the clinical establishment of this procedure would be a higher accuracy of the PSI compared to the conventional PSI fabrication method with better cosmetic results, lower costs and faster availability and production leading to shorter waiting time for the patient, and as a consequence of the higher accuracy leading to shorter operation time, with a reduction of risk of operative adverse events for the patient. Furthermore, the proof of practicability of this new method, could lead to new concepts in the field of Computer-based Patient Specific Implants in modern medicine in general. A clinical trial is necessary to proof the advantages and practicability of the investigators' concept of computer-based algorithm for PSI design (CAPSID) for patients with skull defects.

• Study Type: Observational
• Enrollment (Actual): 15

Contacts and Locations

Study Locations

• Switzerland
  • Bern, Switzerland, 3010
    • Dep. of Neurosurgery, Bern University Hospital

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 18 years to 89 years (Adult, Older Adult)
• Accepts Healthy Volunteers: No
• Genders Eligible for Study: All

• Sampling Method: Non-Probability Sample

Study Population

Patients with skull defects after craniotomy for example tumor resection, head trauma, stroke, need a Patient Specific Implant (PSI).

Description

Inclusion Criteria:

• Patients with skull defects due to craniotomy who need a Patient Specific Implant (PSI) of the skull
• Age older than 18 and less than 90 years
• Provided written informed consent

Exclusion Criteria:

• Contraindications to the class of drugs under study, e.g. known hypersensitivity or allergy to Palacos
• Women who are pregnant or breast feeding
• Intention to become pregnant during the course of the study
• Known coagulopathy
• Severe disease with limited life expectancy of less than one year

Study Plan

How is the study designed?

Design Details

• Observational Models: Case-Control
• Time Perspectives: Prospective

Number of groups / cohorts

1

Cohorts and Interventions

Group / Cohort	Intervention / Treatment
Patients with skull defects; Patients with skull defects after craniotomy for example tumor resection, head trauma, stroke which need a Patient Specific Implant.	Other: Patient Specific Implant; Implantation of Patient Specific Implant

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Time Frame
Number of patients where there is no need to adapt the PSI's edges	6 weeks after surgery by standardised questionnaire
Number of patients where there is no need to augment/fill clefts between the PSI and patient´s bone	6 weeks after surgery by standardised questionnaire
Number of patients where there is no need to discard the PSI and fabricate a new PSI	6 weeks after surgery by standardised questionnaire

Secondary Outcome Measures

Outcome Measure	Time Frame
Operation duration	intraoperative
Patient's satisfaction measured by questionary	6 weeks
infection rate	day 1-3 after OP, at 6 weeks
postoperative haemorrhage	day 1-3 after OP, at 6 weeks
postoperative cerebrospinal fluid leakage	day 1-3 after OP, at 6 weeks
PSI-displacement	day 1-3 after OP, at 6 weeks
need for reoperation	day 1-3 after OP, at 6 weeks
Accuracy of the PSI determined by volumetric analysis of the patient´s post-implantation CT scan (dice similarity index)	3 days after surgery
Accuracy of the PSI determined by volumetric analysis of the patient´s post-implantation CT scan (volumetric inaccuracy index)	3 days after surgery

Collaborators and Investigators

• Sponsor: University Hospital Inselspital, Berne
• Investigators: Principal Investigator: Philippe Schucht, MD, University Hospital Inselspital

Publications and helpful links

General Publications

• Della Puppa A, Rustemi O, Gioffre G, Troncon I, Lombardi G, Rolma G, Sergi M, Munari M, Cecchin D, Gardiman MP, Scienza R. Predictive value of intraoperative 5-aminolevulinic acid-induced fluorescence for detecting bone invasion in meningioma surgery. J Neurosurg. 2014 Apr;120(4):840-5. doi: 10.3171/2013.12.JNS131642. Epub 2014 Jan 10.
• Lassen B, Helseth E, Ronning P, Scheie D, Johannesen TB, Maehlen J, Langmoen IA, Meling TR. Surgical mortality at 30 days and complications leading to recraniotomy in 2630 consecutive craniotomies for intracranial tumors. Neurosurgery. 2011 May;68(5):1259-68; discussion 1268-9. doi: 10.1227/NEU.0b013e31820c0441.
• Stieglitz LH, Fung C, Murek M, Fichtner J, Raabe A, Beck J. What happens to the bone flap? Long-term outcome after reimplantation of cryoconserved bone flaps in a consecutive series of 92 patients. Acta Neurochir (Wien). 2015 Feb;157(2):275-80. doi: 10.1007/s00701-014-2310-7. Epub 2014 Dec 24.
• Chim H, Gosain AK. Biomaterials in craniofacial surgery: experimental studies and clinical application. J Craniofac Surg. 2009 Jan;20(1):29-33. doi: 10.1097/SCS.0b013e318190dd9e.
• Stieglitz LH, Gerber N, Schmid T, Mordasini P, Fichtner J, Fung C, Murek M, Weber S, Raabe A, Beck J. Intraoperative fabrication of patient-specific moulded implants for skull reconstruction: single-centre experience of 28 cases. Acta Neurochir (Wien). 2014 Apr;156(4):793-803. doi: 10.1007/s00701-013-1977-5. Epub 2014 Jan 18.

Study record dates

Study Major Dates

• Study Start: September 1, 2016
• Primary Completion (Actual): June 1, 2019
• Study Completion (Actual): August 1, 2019

Study Registration Dates

• First Submitted: June 21, 2016
• First Submitted That Met QC Criteria: July 6, 2016
• First Posted (Estimate): July 11, 2016

Study Record Updates

• Last Update Posted (Actual): September 4, 2019
• Last Update Submitted That Met QC Criteria: September 3, 2019
• Last Verified: September 1, 2019

More Information

Terms related to this study

• Keywords: stroke; head trauma; Patient Specific Implant; skull defect
• Additional Relevant MeSH Terms: Nervous System Diseases; Wounds and Injuries; Trauma, Nervous System; Craniocerebral Trauma
• Other Study ID Numbers: CAPSID

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: Yes