Performance of different osteosynthesis materials in microvascular fibula free flap reconstruction.

Fibular free flap (FFF) is the main reconstructive choice for large mandibular defects. Recent improvements have been made regarding planning and surgical procedure, but choice of osteosynthesis material (OSM) for segment-fixation remains controversial. A retrospective cohort study obtained clinical and radiological data from FFF-patients. Data were screened for OSM, surgical procedure and complications as OSM fractures, loosening, exposure, or insufficient osseous consolidation. Eighty patients with FFF were included. Planning was CAD/CAM (n=29), Recon Guide (n=26) or without planning (n=25). OSM was 2.0mm-miniplates in standard (n=26), preformed (n=6), CAD/CAM (n=14) or ReconGuide (n=23) variation and 2.3mm-reconstruction-plates in standard (n=5) or CAD/CAM (n=6) variation. Complications were observed in 21 cases, fractures occurred 10 times overall, but with low rates for preformed (n=1), ReconGuide (n=3) and none for CAD/CAM. Analysis detected significant correlations between used OSM and plate exposure (p = 0.000), but none regarding fracture (p = 0.275), loosening (p = 0.714) or insufficient osseous consolidation (p = 0.208). No correlations were observed between complications and OSM (p = 0.609) or diagnosis (p = 0.716). Fixation of FFF segments for reconstruction is possible with various OSM providing good clinical outcome. No significant differences were detected regarding prevention of complications by any osteosynthesis material (miniplate vs. macroplate). Although no differences were detected, miniplate usage is advocated whenever clinically reasonable, due to easier reintervention possibilities and reduced implanted foreign material. Nevertheless, decision for ideal OSM must remain patient-specific and cannot be generalised.

Macrophage polarisation changes within the time between diagnostic biopsy and tumour resection in oral squamous cell carcinomas--an immunohistochemical study.

BACKGROUND: The prognosis of solid malignancies has been shown to depend on immunological parameters, such as macrophage polarisation (M1/M2). Recently, it was reported that preoperative oral surgery leads to a worsening of oral squamous cell carcinomas (OSCC) prognosis. Diagnostic incision biopsies are oral surgery procedures that might lead to healing-associated M2 macrophage polarisation with a potential negative influence on tumour biology. No studies have compared macrophage polarisation in OSCC biopsies and tumour specimens. METHODS: Preoperative diagnostic incision biopsies (n=25) and tumour resection specimens (n=34) of T1/T2 OSCC were processed for immunohistochemistry to detect CD68-, CD11c-, CD163- and MRC1-positive cells. Samples were digitised using whole-slide imaging, and the expression of macrophage markers was quantitatively analysed. RESULTS: Carcinoma tissues obtained during OSCC tumour resections showed a significantly (P<0.05) increased CD163 cell count (M2 macrophages) compared with tissues obtained during preoperative incision biopsies. Additionally, the CD163/CD68 ratio (an indicator of M2 polarisation) was significantly (P<0.05) higher in tumour resection specimens than in biopsies. CONCLUSIONS: This study revealed for the first time an increase in M2 polarisation in samples obtained during OSCC tumour resection surgery compared with preoperative incision biopsies. The biopsy-induced tissue trauma might explain the observed shift in macrophage polarisation towards the tumour-promoting M2 type and could lead to accelerated tumour progression.

Perioperative factors that influence the outcome of microsurgical reconstructions in craniomaxillofacial surgery.

Microsurgical tissue transfer is a well-established way of reconstructing the head and neck, but there are still many postoperative complications that require revision. The aim of this study was to clarify perioperative factors and characteristics of patients that influence the success of the flap and the need for revision. We retrospectively studied 368 patients who were treated with microsurgical free tissue transfer in the head and neck area at the Department of Oral and Maxillofacial Surgery at the University Medical Centre, Erlangen, between 2004 and 2009. Investigations concentrated on patients' characteristics and operative factors. Free scapular or parascapular flaps (n=161, 44%) and radial forearm flaps (n=119, 32%) were predominantly used for the reconstruction of major defects in the mandible and the floor of the mouth. In 39 patients (11%) revision was required, which resulted in a success rate of 96%. There was a significant association between preoperative American Society of Anesthesiologists (ASA) grade and postoperative survival of the flap (p=0.04). Patients previously treated by irradiation required significantly more revisions than those not so treated (p=0.04). The use of vein grafts was also significantly associated with the need for revision (p=0.02). The ASA grade influenced the success rate but was not associated with the number of revisions. These factors must be taken into consideration when intervention is planned to reduce the number of postoperative complications and interventions further.