Journal of Cranio-Maxillo-Facial Surgery 42 (2014) 1948e1951
Contents lists available at ScienceDirect
Journal of Cranio-Maxillo-Facial Surgery journal homepage: www.jcmfs.com
Interval cranioplasty with patient-specific implants and autogenous bone grafts e Success and cost analysis Bernd Lethaus a, Monique Bloebaum a, David Koper a, Mariel Poort-ter Laak b, Peter Kessler a, * a b
Department of Cranio-Maxillofacial Surgery, Maastricht University Medical Center, P. Debeyelaan 25, AZ 6202 Maastricht, The Netherlands Department of Neurosurgery, Maastricht University Medical Center, P. Debeyelaan 25, AZ 6202 Maastricht, The Netherlands
a r t i c l e i n f o
a b s t r a c t
Article history: Paper received 29 June 2014 Accepted 25 August 2014 Available online 2 September 2014
Different options exist for the reconstruction of craniectomy defects following interval cranioplasty. The standard procedure is still based on the re-implantation of autogenous bone specimen which can be stored in the abdominal wall or be cryopreserved. Alternatively patient-specific implants (PSIs) can be used. We conducted a retrospective study based on 50 consecutive patients with skull bone defects of 100 cm2 or more being operated on by the same team of surgeons. Thirty-three patients agreed to take part in the study. Seventeen patients who underwent reconstruction with PSIs (titanium and polyether ether ketone, PEEK) (follow-up, 43 months [range, 3e93]) were compared with 16 control subjects who had autogenous bone grafts re-implanted (follow-up, 32 months [range, 5e92]). Criteria analyzed were the success and complication rates, operation time, duration of hospitalization and the treatment costs. Complication rate and the rate of reoperation were significantly lower, and the hospital stay was shorter in the PSI group. The treatment costs for reconstruction with autogenous bone were considerably lower than skull bone reconstruction based on PSIs (average costs: 10849.91 V/patient versus 15532.08 V/ patient with PSI). Due to biological reasons some of the autogenous bone implants fail due to infection and resorption and the patients have to undergo another operation with implantation of a PSI in a secondary attempt. For those patients the highest overall treatment costs must be calculated (average costs: 26086.06 V/patient with secondary stage PSI versus 15532.08 V/patient with primary stage PSI). Conclusion: High success rates and reliability of PSIs may change the treatment strategy in patients undergoing interval cranioplasty. © 2014 European Association for Cranio-Maxillo-Facial Surgery. Published by Elsevier Ltd. All rights reserved.
Keywords: Cranioplasty Craniectomy Patient specific implant Autogenous bone grafts Treatment costs
1. Introduction Cranial trauma, intracranial haemorrhages and apoplectic insults create life threatening medical conditions. Decompressive craniectomy has become a critical and standard life-saving manoeuvre in the operation theatre. Large skull bone segments have to be removed during this procedure. Other indications for craniectomy are intracranial disorders caused by tumours, epileptic € ller, surgery or infections (Eufinger et al., 1995; Eufinger and Wehmo 1998, 2002; Lethaus et al., 2011). Like in other countries in the Netherlands the harvested bone specimen can be preserved deep frozen or implanted and preserved in the abdominal wall. Due to ageing, but also for other reasons the number of craniectomy * Corresponding author. Department of Cranio-Maxillofacial Surgery, Maastricht University Medical Center MUMC, P Debeyelaan, Postbus 5800, NL-6202 Maastricht, The Netherlands. Tel.: þ31 43 387 2010; fax: þ31 43 387 2020. E-mail address: [email protected] (P. Kessler).
patients or patients with cranial defects asking for reconstruction is increasing. The autogenous bone is still considered to be the gold standard in the reconstruction of cranial defects, but alternatives, e.g. noncustomized and customized alloplastic implants of different ma€ ller, terials may also be used (Blake et al., 1990; Eufinger and Wehmo 1998; Rupprecht et al., 2003; Lethaus et al., 2011, 2012). Reimplantation of autogenous bone specimen can result in infection or resorption leading to further interventions (Lethaus et al., 2011). Computer aided design (CAD) and manufacturing (CAM) deliver individual, highly precise patient specific implants (PSI). Different materials, such as titanium, various plastics and ceramics can be processed by different manufacturing techniques such as highspeed milling, selective laser sintering and casting (Klein et al., 1994; Jahur-Grodzinski, 1999; Hutmacher et al., 2004; Rechtenwald et al., 2004; Schiller et al., 2004; Li et al., 2005; Rodil et al., 2005; Schmidt et al., 2007; von Wilmowsky et al., 2008).
http://dx.doi.org/10.1016/j.jcms.2014.08.006 1010-5182/© 2014 European Association for Cranio-Maxillo-Facial Surgery. Published by Elsevier Ltd. All rights reserved.
B. Lethaus et al. / Journal of Cranio-Maxillo-Facial Surgery 42 (2014) 1948e1951
Based on the experience gained from two studies financed by the European Community (Custom-FIT/Custom-IMD) we present the state-of-the-art treatment concept in the reconstruction of large skull bone defects at the Maastricht University Medical Hospital (MUMC). This study compares success, complication rates, operation times, duration of hospitalization and the cost aspect of skull defect reconstruction using autogenous bone and PSIs. 2. Material and methods 2.1. Selection of patients Between April 2006 and December 2013 50 patients were consecutively operated on by the same surgical team consisting of a neurosurgeon and a craniofacial surgeon. Thirty-three patients were selected for the retrospective study. Seventeen patients had received PSIs, 16 autogenous skull bone grafts that had been explanted beforehand. Exclusion criteria were immediate cranioplasties, multiply re-operated patients, patients younger than the age of 16 and cases with incomplete data. Table 1 gives further details. In group two the skull bone specimen had been stored in the abdominal wall in six patients and cryopreserved in the remaining ten (gamma irradiation 25 kGy, storage at 80 C). In ten patients PSIs made from titanium were implanted, in seven patients the implants were made from polyether ether ketone (PEEK). All PSIs were fabricated by the same company (XILLOC Medical b.v., Maastricht, The Netherlands) according to a defined scanning and manufacturing protocol that has been published before (Poukens et al., 2008; Lethaus et al., 2011). The cost analysis has been performed on the true costs that are spent for this patient group according the Dutch financing in medical health care.
(1/17) patient of group 1, but 6 (6/16) of group 2 needed reoperation (p ¼ 0.599). The median length of hospital stay was 6.4 days (range 3e27) in group 1, whereas patients of group 2 had to stay on average 13.6 days (range 5e38). Duration of hospitalization, but also the results for the overall success and complication rate were significantly better (Table 2). Despite the higher rate of complications, the necessity of reoperations and the longer hospital stay the primary reconstructive treatment of patients in group 2 was less expensive. This is due to the high manufacturing costs of PSIs in group 1. Tables 3 and 4 refer to the financial aspect of the study. If one includes the costs for reoperation (secondary reconstructive attempt) of patients of group 2 where autogenous bone grafts failed the overall costs for those patients would be the highest (Table 4). 4. Discussion Large bone defects of any location still pose a challenge in reconstructive surgery. To avoid extensive bone transplantations a lot of hope was drawn from the promising attempts to achieve bone regeneration artificially by the application of mediators such as bone morphogenetic proteins (BMP) directly to the deficient tissue site. BMPs, as promoters of the regenerative process, have proven their ability to induce de novo bone formation in various tissues, and many animal models have demonstrated their high potential for ectopic and orthotopic bone formation. Local delivery of the inductive stimulus remains a problem in clinical applications (Kroczek et al., 2010). Furthermore the question of an ideal carrier to deliver promoting proteins to the target cells is not yet answered. Table 2 Clinical results.
2.2. Statistical analysis The data were collected in SPSS (IBM Corporation, Armonk, NY, USA). Fischer's exact test and ManneWhitney tests were applied for statistical significance related to the following items: method of storage, duration of operation, duration of hospitalization, complications and reoperations. P-values
Contents lists available at ScienceDirect
Journal of Cranio-Maxillo-Facial Surgery journal homepage: www.jcmfs.com
Interval cranioplasty with patient-specific implants and autogenous bone grafts e Success and cost analysis Bernd Lethaus a, Monique Bloebaum a, David Koper a, Mariel Poort-ter Laak b, Peter Kessler a, * a b
Department of Cranio-Maxillofacial Surgery, Maastricht University Medical Center, P. Debeyelaan 25, AZ 6202 Maastricht, The Netherlands Department of Neurosurgery, Maastricht University Medical Center, P. Debeyelaan 25, AZ 6202 Maastricht, The Netherlands
a r t i c l e i n f o
a b s t r a c t
Article history: Paper received 29 June 2014 Accepted 25 August 2014 Available online 2 September 2014
Different options exist for the reconstruction of craniectomy defects following interval cranioplasty. The standard procedure is still based on the re-implantation of autogenous bone specimen which can be stored in the abdominal wall or be cryopreserved. Alternatively patient-specific implants (PSIs) can be used. We conducted a retrospective study based on 50 consecutive patients with skull bone defects of 100 cm2 or more being operated on by the same team of surgeons. Thirty-three patients agreed to take part in the study. Seventeen patients who underwent reconstruction with PSIs (titanium and polyether ether ketone, PEEK) (follow-up, 43 months [range, 3e93]) were compared with 16 control subjects who had autogenous bone grafts re-implanted (follow-up, 32 months [range, 5e92]). Criteria analyzed were the success and complication rates, operation time, duration of hospitalization and the treatment costs. Complication rate and the rate of reoperation were significantly lower, and the hospital stay was shorter in the PSI group. The treatment costs for reconstruction with autogenous bone were considerably lower than skull bone reconstruction based on PSIs (average costs: 10849.91 V/patient versus 15532.08 V/ patient with PSI). Due to biological reasons some of the autogenous bone implants fail due to infection and resorption and the patients have to undergo another operation with implantation of a PSI in a secondary attempt. For those patients the highest overall treatment costs must be calculated (average costs: 26086.06 V/patient with secondary stage PSI versus 15532.08 V/patient with primary stage PSI). Conclusion: High success rates and reliability of PSIs may change the treatment strategy in patients undergoing interval cranioplasty. © 2014 European Association for Cranio-Maxillo-Facial Surgery. Published by Elsevier Ltd. All rights reserved.
Keywords: Cranioplasty Craniectomy Patient specific implant Autogenous bone grafts Treatment costs
1. Introduction Cranial trauma, intracranial haemorrhages and apoplectic insults create life threatening medical conditions. Decompressive craniectomy has become a critical and standard life-saving manoeuvre in the operation theatre. Large skull bone segments have to be removed during this procedure. Other indications for craniectomy are intracranial disorders caused by tumours, epileptic € ller, surgery or infections (Eufinger et al., 1995; Eufinger and Wehmo 1998, 2002; Lethaus et al., 2011). Like in other countries in the Netherlands the harvested bone specimen can be preserved deep frozen or implanted and preserved in the abdominal wall. Due to ageing, but also for other reasons the number of craniectomy * Corresponding author. Department of Cranio-Maxillofacial Surgery, Maastricht University Medical Center MUMC, P Debeyelaan, Postbus 5800, NL-6202 Maastricht, The Netherlands. Tel.: þ31 43 387 2010; fax: þ31 43 387 2020. E-mail address: [email protected] (P. Kessler).
patients or patients with cranial defects asking for reconstruction is increasing. The autogenous bone is still considered to be the gold standard in the reconstruction of cranial defects, but alternatives, e.g. noncustomized and customized alloplastic implants of different ma€ ller, terials may also be used (Blake et al., 1990; Eufinger and Wehmo 1998; Rupprecht et al., 2003; Lethaus et al., 2011, 2012). Reimplantation of autogenous bone specimen can result in infection or resorption leading to further interventions (Lethaus et al., 2011). Computer aided design (CAD) and manufacturing (CAM) deliver individual, highly precise patient specific implants (PSI). Different materials, such as titanium, various plastics and ceramics can be processed by different manufacturing techniques such as highspeed milling, selective laser sintering and casting (Klein et al., 1994; Jahur-Grodzinski, 1999; Hutmacher et al., 2004; Rechtenwald et al., 2004; Schiller et al., 2004; Li et al., 2005; Rodil et al., 2005; Schmidt et al., 2007; von Wilmowsky et al., 2008).
http://dx.doi.org/10.1016/j.jcms.2014.08.006 1010-5182/© 2014 European Association for Cranio-Maxillo-Facial Surgery. Published by Elsevier Ltd. All rights reserved.
B. Lethaus et al. / Journal of Cranio-Maxillo-Facial Surgery 42 (2014) 1948e1951
Based on the experience gained from two studies financed by the European Community (Custom-FIT/Custom-IMD) we present the state-of-the-art treatment concept in the reconstruction of large skull bone defects at the Maastricht University Medical Hospital (MUMC). This study compares success, complication rates, operation times, duration of hospitalization and the cost aspect of skull defect reconstruction using autogenous bone and PSIs. 2. Material and methods 2.1. Selection of patients Between April 2006 and December 2013 50 patients were consecutively operated on by the same surgical team consisting of a neurosurgeon and a craniofacial surgeon. Thirty-three patients were selected for the retrospective study. Seventeen patients had received PSIs, 16 autogenous skull bone grafts that had been explanted beforehand. Exclusion criteria were immediate cranioplasties, multiply re-operated patients, patients younger than the age of 16 and cases with incomplete data. Table 1 gives further details. In group two the skull bone specimen had been stored in the abdominal wall in six patients and cryopreserved in the remaining ten (gamma irradiation 25 kGy, storage at 80 C). In ten patients PSIs made from titanium were implanted, in seven patients the implants were made from polyether ether ketone (PEEK). All PSIs were fabricated by the same company (XILLOC Medical b.v., Maastricht, The Netherlands) according to a defined scanning and manufacturing protocol that has been published before (Poukens et al., 2008; Lethaus et al., 2011). The cost analysis has been performed on the true costs that are spent for this patient group according the Dutch financing in medical health care.
(1/17) patient of group 1, but 6 (6/16) of group 2 needed reoperation (p ¼ 0.599). The median length of hospital stay was 6.4 days (range 3e27) in group 1, whereas patients of group 2 had to stay on average 13.6 days (range 5e38). Duration of hospitalization, but also the results for the overall success and complication rate were significantly better (Table 2). Despite the higher rate of complications, the necessity of reoperations and the longer hospital stay the primary reconstructive treatment of patients in group 2 was less expensive. This is due to the high manufacturing costs of PSIs in group 1. Tables 3 and 4 refer to the financial aspect of the study. If one includes the costs for reoperation (secondary reconstructive attempt) of patients of group 2 where autogenous bone grafts failed the overall costs for those patients would be the highest (Table 4). 4. Discussion Large bone defects of any location still pose a challenge in reconstructive surgery. To avoid extensive bone transplantations a lot of hope was drawn from the promising attempts to achieve bone regeneration artificially by the application of mediators such as bone morphogenetic proteins (BMP) directly to the deficient tissue site. BMPs, as promoters of the regenerative process, have proven their ability to induce de novo bone formation in various tissues, and many animal models have demonstrated their high potential for ectopic and orthotopic bone formation. Local delivery of the inductive stimulus remains a problem in clinical applications (Kroczek et al., 2010). Furthermore the question of an ideal carrier to deliver promoting proteins to the target cells is not yet answered. Table 2 Clinical results.
2.2. Statistical analysis The data were collected in SPSS (IBM Corporation, Armonk, NY, USA). Fischer's exact test and ManneWhitney tests were applied for statistical significance related to the following items: method of storage, duration of operation, duration of hospitalization, complications and reoperations. P-values
