Date Published: February 14, 2017
Publisher: Springer International Publishing
Author(s): Elisabeth Goetze, Matthias Gielisch, Maximilian Moergel, Bilal Al-Nawas.
Major facial defects due to cancer or deformities can be reconstructed through microvascular osteocutaneous flaps. Hereby CAD/CAM workflows offer a possibility to optimize reconstruct and reduce surgical time. We present a retrospectiv observational study regarding the developement of an in-house workflow allowing an accelerated CAD/CAM fibula reconstruction without outsourcing.
Workflow includes data acquisition through computertomography of head and legs, segmentation of the data and virtual surgery. The virtual surgery was transferred into surgical guides and prebent osteosynthesis plate. Those were sterilized and used in surgery.
The workflow was used in 30 cases. Minimum planning period took 4 days from CT to surgery, average time was 8 days. Planning could be transferred to surgery every time. Intraoperative complications regarding osteotomy, assembly and fixation did not occur.
An in-house workflow for CAD/CAM fibula reconstruction is feasible within a few days providing an accelerated procedure even in urgent cases.
Advanced tumors or progressive chronic inflammation of the jaws frequently require segmental resection. Thereafter reconstruction by free microvascular bone transfer represents nowadays the method of choice in patients with acceptable health status [1–4]. For reconstruction of the upper and particularly the lower jaw the microvascular fibula flap is mostly utilized for extended bone defects and regularly allows integration of a skin paddle p [5, 6]. The basic concept in raising free fibula flaps was first described by Taylor in 1975 but has evolved in parts over the last decade [2, 7]. Surgery can be supported by computer aided design (CAD) based planning and preoperative manufacturing (computer aided manufacture, CAM) of surgical templates [7–9]. A CAD/CAM workflow allows preoperative definition of cutting paths and angles at the resection site, modeling of the graft as well as the shape of the osteosynthesis material resulting in an easy composable and placeable reconstruct . The overall assembly time consisting in intraoperative cutting, positioning and refinement of the graft is reduced by the CAD/CAM workflow [7, 10], thereby substantially reducing risks concomitant with long-time surgery [11–13]. Last but not least integrated CAD/CAM workflow may improve the esthetic and functional outcome by optimizing position and contour of the reconstruct [7, 14].
Retrospective analysis was done for 30 patients, the case of one patient is illustrated as full workflow. All patients gave written consent into the procedure and use of their data. For the case report the patient gave written consent in the publication of his pictures. The need of ethics approval was waived by the Ethics Commission of the State Chamber of Medicine in Rhineland-Pfalz according to Berufsordnung § 15 and Landeskrankenhausgesetz § 36 und § 37.
The workflow was applied in 30 cases for primary and secondary reconstruction in the time from January 2014 to January 2016. The gender distribution was 1:2 (female:male). Average age was 50 years (50 ± 17). Eight patients underwent secondary reconstruction after a tumor free interval of 1–6 years, all other patients were primarily reconstructed with tumor resection during the same surgery. All patients were reconstructed with a free microvascular anastomized fibula bone graft. Two patients did not require skin graft, 19 patients had intraoral, six patients extraoral and three patients combined intra-/extraoral skin grafts.
Thirty patients were successfully planned through an in-house CAD/CAM algorithm for reconstruction with a fibula graft. Major complications did not occur in relation to the planning itself and was attributed to pre-radiated patients. Higher risk of complications and flap loss for this patient group are described in literature [20, 21]. As far this workflow solution was just used for fibula graft but could also be applied to other bone grafts like scapula or iliac crest flaps [6, 22]. In literature assessment of surgical time regarding CAD/CAM procedures is heterogenic but mostly states time reduction [7, 10, 23]. The percepted reduction of surgical time has not been tested here, but leads to a lower risk of general complications [11–13].
In conclusion it can be stated, that it is possible to apply a CAD/CAM workflow to fibula graft reconstruction within a few days making this technique available for immediate primary reconstruction of malignant tumors.