Advantages of virtual planning in reconstructive surgery of bone defects in the maxillofacial region.

OBJECTIVES: Our analysis focuses on the advantages of virtual surgical planning (VSP) compared to a conventional treatment method as well as on a wider range of parameters influencing the surgical procedure, postoperative care, morbidity and lastly, the survival rate of these patients. BACKGROUND: Patients with extensive bone defects of different etiologies of the upper or lower jaw who underwent complex reconstructive surgery with a free fibula flap (FFF). METHODS: We retrospectively analyzed data from a total of 34 patients (12 female and 22 male) whose defects were reconstructed with an osteomyocutaneus FFF. The data were collected over a period of 6 years from 2017 to 2023. We divided the patients into two groups, namely those who underwent conventional surgical treatment (5 patients) and those who underwent computer­planned surgical treatment (29 patients). RESULTS: The duration of surgery showed a significant difference between the VSP group and the conventional group (t(32) = 3.316; p < 0.01), with the VSP group having a significantly shorter surgery time (M= 8:10; SD = 1:18) compared to the conventional group (M = 10:52; SD = 2:41). The independent t-test revealed significant differences between the VSP group (M = 45.967; SD 14.548) and conventional group (M = 17.61; SD = 24.996) for the dose of unfractionated heparin per kilogram administrated immediately after vascular micro anastomosis (t(32) = -3.609; p < 0.001). CONCLUSION: Among all the risk factors, administering a higher unfractionated dosage of heparin administered immediately after completing the anastomosis was identified as a significant predictor of postoperative complications. Using VSP in cases of advanced stage head and neck malignancy for salvage surgery is highly recommended. Shorter duration of these comprehensive surgeries in the VSP group leads to a significantly favorable outcome (Tab. 2, Fig. 2, Ref. 19). Text in PDF www.elis.sk Keywords: virtual planning, microvascular flap, maxillofacial, free fibula flap, reconstructive surgery.

Near infrared spectroscopy in monitoring of head and neck microvascular free flaps.

OBJECTIVES: Microvascular free­flap monitoring is crucial to the early detection of flap failure and increases the chance of early intervention in case of disruption of perfusion to a flap. Many clinical alternatives to classical clinical flap monitoring have been proposed, such as color duplex ultrasonography, handheld Doppler, flap thermometry, or implantable Doppler flowmetry. Early detection of critical changes in tissue oxygenation can lead to successful surgical intervention when problems with flap nutrition arise. METHODS: Our clinical study seeks to investigate dynamic monitoring of free flaps with near­infrared spectroscopy (NIRS). NIRS is a non-invasive instrumental technique used for continuous monitoring of peripheral tissue oxygenation (StO2) and microcirculation. All patients were included prospectively from one clinical center. RESULTS: During the clinical research period, 18 patients underwent extraoral head and neck reconstruction with one of three types of free flap, namely with radial forearm free flap (RFFF), anterolateral thigh flap (ALT) or fibula free flap (FFF). Measurements of flap perfusion were taken using NIRS during intraoperative and postoperative phases for 71 hours on average. A total of 6 perfusion disorders were recorded, of which three originated from microanastomoses and three from postoperative bleeding and compression of pedicle. NIRS showed characteristic changes in all 6 cases that were returned to the operating theatre owing to pedicle compromise. In these cases, NIRS had detected the pedicle compromise before it was clinically identified. A single StO2 monitoring was able to detect the vascular compromise with 100% sensitivity and 95.65% specificity. None of the cases were falsely positive. In our study, all compromised flaps were accurately identified by means of NIRS. In most cases, the changes in oxygen saturation became evident on NIRS prior to being clinically observed. CONCLUSION: In our study, the continuous NIRS monitoring securely detected the early stages of arterial and venous thromboses or pedicle compression. The most important aspects of monitoring the flaps´ microvascular perfusion and vitality by means of NIRS lie in its function of recording the dynamics of changes in the values ​​of absolute oxygen saturation (StO2> 50%) alongside with detecting a 30% decrease in tissue saturation over a 60­minute interval (60 min StO2 >30%) before the clinical changes in the microvascular flap become observable. In cases of pedicle compression, the average time of appearance of signs of StO2 values dropping below the reference interval (as detected by NIRS) was 1:29:02 hour (SD= 0:58:42 h) prior to the occurrence of any clinical signs, while in cases of microvascular anastomosis complications, it was 0:35:23 hour (SD=0:08:30 h)  (SD = 0:08:30 h) (Tab. 3, Fig. 7, Ref. 42).

Three-dimensional navigation in maxillofacial surgery - the way to minimize surgical stress and improve accuracy in fibula free flap and Eagles syndrome surgical procedures.

BACKGROUND: Surgical navigation with three-dimensional (3D) printing techniques presents two major advantages: First, from a technical aspect, it facilitates orientation in target anatomical structures resulting in improvement of the accuracy of surgery. Moreover, it shortens the time of complex surgical interventions by preparing the exact position of customized autologous grafts with fixation devices. Second, from a clinical point of view, it also lessens the impact of surgical stress to adjacent tissues by decreasing the duration of surgery. MATERIAL AND METHODS: Two maxillofacial procedures were evaluated in this study using 3D navigation and planning approach - resection of the styloid process due to Eagles syndrome and microvascular mandibular reconstruction with the fibula free flap. All patients who underwent these procedures were divided into two groups (with or without 3D navigation). RESULTS: In the Eagles syndrome group procedure independent t-test showed  significant difference in the operating time between group 1 (M = 148; SD = 0) and group 2 (M = 78; SD = 4.24) t (1) = 13.472; P = 0.047. There was no significant difference in the duration of postoperative hospitalization (2 days), which was equal in all patient groups. Regarding the fibula free flap procedure, the independent t-test revealed significant difference in operating time with (M = 8: 40 : 25; SD = 0 : 58 : 07) and without 3D printing guides (M = 10 : 43 : 15; SD = 3 : 04 : 32) t (14)=2.133, P = 0.051. Similarly, there was no significant difference between groups (group 1 M = 15.5; SD = 0,71; group 2 M = 13; SD = 1,63) in the duration of postoperative hospitalization time t (4) =1,98; P = 0.119. CONCLUSION: In summary, reduction in operation time in Eagles syndrome and in microvascular mandibular reconstruction with the fibula free flap group mitigates the surgical stress on target tissues enabling faster tissue healing and quicker recovery.