Perioperative anticoagulation in head and neck free flap reconstructions: Experience of an anticoagulative scheme and its modification.

OBJECTIVES: Microvascular anastomoses in microvascular reconstructions induce rheological changes in the anastomosed vessels and are usually counteracted by anticoagulative medication. There is no regimen commonly agreed on. This study provides an easy to use anticoagulative regimen. PATIENTS AND METHODS: Consecutive cases of either anticoagulative regimen between 2013 and 2018 that underwent microvascular reconstruction in the head and neck area were included in this retrospective study, resulting in 400 cases in total. Two different anticoagulative regimens were applied to 200 patients in each group: (a) intraoperatively administered unfractionated 5000 I.U. high molecular weight heparin (HMWH) and postoperatively low molecular weight heparin (LMWH, Enoxaparin) 1 mg/kg/body weight postoperatively and (b) intraoperatively LMWH 0.5 mg/kg/body weight as well as 12 h later and 1 mg/kg/body weight postoperatively. RESULTS: The LMWH cohort showed fewer overall thromboembolic (8.5% vs. 11%; p = .40) and peripheral thrombotic events (1% vs. 3.5%; p = .18) and lung embolisms (3% vs. 4%; p = .59). The number of thromboses at the site of the anastomosis was equally distributed. In regard to flap-specific complications, LMWH was associated with a positive effect, in particular with respect to total flap losses (5% vs. 7%; p = .40) and wound-healing disorders (14.5% vs. 20%; p = .145). CONCLUSION: Findings indicate that intra- and postoperatively administered LMWH as the only anticoagulative medication seems reliable in our clinical routine of head and neck free flap reconstructions.

The impact of passive alveolar molding vs. nasoalveolar molding on cleft width and other parameters of maxillary growth in unilateral cleft lip palate.

OBJECTIVE: Passive alveolar molding (PAM) and nasoalveolar molding (NAM) are established presurgical infant orthodontic (PSIO) therapies for cleft lip palate (CLP) patients. PAM guides maxillary growth with a modified Hotz appliance, while NAM also uses extraoral taping and includes nasal stents. The effects of these techniques on alveolar arch growth have rarely been compared. MATERIAL AND METHODS: We retrospectively compared 3D-scanned maxillary models obtained before and after PSIO from infants with unilateral, non-syndromic CLP treated with PAM (n = 16) versus NAM (n = 13). Nine anatomical points were set digitally by four raters and transversal/sagittal distances and rotations of the maxilla were measured. RESULTS: Both appliances reduced the anterior cleft, but NAM percentage wise more. NAM decreased the anterior and medial transversal width compared to PAM, which led to no change. With both appliances, the posterior width increased. The alveolar arch length of the great and small segments and the sagittal length of the maxilla increased with PAM but only partially with NAM. However, NAM induced a significant greater medial rotation of the larger and smaller segment compared to PAM with respect to the lateral angle. CONCLUSIONS: NAM and PAM presented some significant differences regarding maxillary growth. While NAM reduced the anterior cleft and effectively rotated the segments medially, PAM allowed more transversal and sagittal growth. CLINICAL RELEVANCE: The results of this study should be taken into consideration when to decide whether to use PAM or NAM, since they show a different outcome within the first few months. Further studies are necessary regarding long-term differences.

Imaging of traumatic mandibular fractures in young adults using CT-like MRI: a feasibility study.

OBJECTIVES: To assess and compare the diagnostic performance of CT-like images based on a three- dimensional (3D) T1-weighted spoiled gradient-echo sequence (3D T1 GRE) with CT in patients with acute traumatic fractures of the mandible. MATERIALS AND METHODS: Subjects with acute mandibular fractures diagnosed on conventional CT were prospectively recruited and received an additional 3 T MRI with a CT-like 3D T1 GRE sequence. The images were assessed by two radiologists with regard to fracture localization, degree of dislocation, and number of fragments. Bone to soft tissue contrast, diagnostic confidence, artifacts, and overall image quality were rated using a five-point Likert-scale. Agreement of measurements was assessed using an independent t-test. RESULTS: Fourteen subjects and 22 fracture sites were included (26 ± 3.9 years; 4 females, 10 males). All traumatic fractures were accurately detected on CT-like MRI (n = 22, κ 1.00 (95% CI 1.00-1.00)). There was no statistically significant difference in the assessment of the fracture dislocation (axial mean difference (MD) 0.06 mm, p = 0.93, coronal MD, 0.08 mm, p = 0.89 and sagittal MD, 0.04 mm, p = 0.96). The agreement for the fracture classification as well as the inter- and intra-rater agreement was excellent (range κ 0.92-0.98 (95% CI 0.96-0.99)). CONCLUSION: Assessment of mandibular fractures was feasible and accurate using CT-like MRI based on a 3D T1 GRE sequence and is comparable to conventional CT. CLINICAL RELEVANCE: For the assessment of acute mandibular fractures, CT-like MRI might become a useful alternative to CT in order to reduce radiation exposure particularly in young patients.

Blood flow analyses by intraoperative transit-time flow measurements of free flaps for head and neck reconstructions: A prospective single-center study.

BACKGROUND: The behavior of blood flow changes within free flaps following microvascular anastomosis is not well described in the literature. The aim of this study was to determine the immediate blood flow behavior of different free flaps as reference values for various clinical applications. METHODS: Intraoperative transit-time flow measurements were performed on patients receiving free flap transfer in the head and neck area comprising radial forearm flaps (RFF), peroneal artery perforator flaps (PAP), anterolateral thigh flaps (ALT), vastus lateralis flaps (VLF), parascapular flaps (PSF), latissimus dorsi flaps (LDF), fibula free flaps (FFF), deep circumflex iliac artery flaps (DCIA), and scapular flaps (SF). In accordance with a structured protocol, measurements took place at the pedicle directly before flap harvesting and at the recipient vessels 1 h after flap transfer. Heart rate, transplant weight, and other patient characteristics were recorded and analyzed. RESULTS: A total of 129 were enrolled, comprising 66 RFF, 8 ALT, 6 PAP, 11 VLF, 3 PSF, 2 LDF, 24 FFF, 7 DCIA, and 2 SF. In most of the transplant groups, arterial perfusion increased after anastomosis at the recipient site. The arterial pulsatility index developed indirectly proportionally to arterial blood flow, whereas venous blood drainage did not show any statistically significant changes. Muscle flaps had the highest arterial perfusion before flap transfer. Composite transplants with hard and soft tissue presented the greatest increase in arterial perfusion. The lowest arterial blood flow after anastomosis was measured in PAP and RFF. In contrast, RFF and PAP presented the highest arterial perfusion per 100 g transplant weight. CONCLUSIONS: Arterial perfusion changed, whereas venous blood flow did not show any statistically significant variations in any transplant group. Perfusion of free flaps does not only depend on the recipient vessel and the recipient bed, but also on flap-specific anatomy and physiology.

Oral bacteria in infective endocarditis requiring surgery: a retrospective analysis of 134 patients.

OBJECTIVES: It has been reported that bacteria associated with infective endocarditis originate from the oral cavity in 26-45% of cases. However, little is known on the counts and species of periodontal microbiota in infected heart valves. The aim of this study was to identify these aspects of periodontal microbiota in infective endocarditis and to potentially initiate a dental extraction concept for periodontally compromised teeth concerning patients requiring heart valve surgery. MATERIALS AND METHODS: The retrospective study group consisted of tissue samples from infected heart valves of 683 patients who had undergone heart valve surgery. Before patients had undergone cardiac surgery, the following laboratory tests confirmed the occurrence of endocarditis in all patients: blood cultures, echocardiography, electrocardiography, chest X-ray, and electrophoresis of the serum proteins. The specimens were aseptically obtained and deep frozen immediately following surgery. Microbiological diagnosis included proof of germs (dichotomous), species of germs, and source of germs (oral versus other). RESULTS: Microbiota was detected in 134 (31.2%) out of 430 enrolled patients. Oral cavity was supposed to be the source in 10.4% of cases, whereas microbiota of the skin (57.5%) and gastrointestinal tract (GIT, 24.6%) were detected considerably more frequently. Moreover, periodontal bacteria belonged mostly to the Streptococci species and the yellow complex. None of the detected bacteria belonged to the red complex. CONCLUSION: Most frequently, the skin and GIT represented the site of origin of the microbiota. Nevertheless, the oral cavity represented the source of IE in up to 10%. Consequently, it needs to be emphasized that a good level of oral hygiene is strongly recommended in all patients undergoing heart valve surgery in order to reduce the bacterial load in the oral cavity, thereby minimizing the hematogenous spread of oral microbiota. The prerequisites for conservative dental treatment versus radical tooth extraction must always be based on the patient's cooperation, and the clinical intraoral status on a sense of proportion in view of the overall clinical situation due to the underlying cardiac disease. CLINICAL RELEVANCE: The oral cavity is a source of oral microbiota on infected heart valves. Patients requiring heart valve surgery should always undergo a critical evaluation of dental treatment affecting periodontally compromised teeth, favoring a systematic, conservative-leaning recall.

CSF disturbances and other neurosurgical complications after interdisciplinary reconstructions of large combined scalp and skull deficiencies.

Combined scalp and skull deficiency due to malignant scalp tumors or sequelae of intracranial surgery present challenging entities for both neurosurgeons and reconstructive treatment. In complex cases, an interdisciplinary approach is needed between neurosurgeons and cranio-maxillofacial surgeons. We present a considerably large series for which we identify typical complications and pitfalls and provide evidence for the importance of an interdisciplinary algorithm for chronic wound healing complications and malignomas of the scalp and skull. We retrospectively reviewed all patients treated by the department of neurosurgery and cranio-maxillofacial surgery at our hospital for complex scalp deficiencies and malignant scalp tumors affecting the skull between 2006 and 2019, and extracted data on demographics, surgical technique, and perioperative complications. Thirty-seven patients were treated. Most cases were operated simultaneously (n: 32) and 6 cases in a staged procedure. Nineteen patients obtained a free flap for scalp reconstruction, 15 were treated with local axial flaps, and 3 patients underwent full thickness skin graft treatment. Complications occurred in 62% of cases, mostly related to cerebrospinal fluid (CSF) circulation disorders. New cerebrospinal fluid (CSF) disturbances occurred in 8 patients undergoing free flaps and shunt dysfunction occurred in 5 patients undergoing local axial flaps. Four patients died shortly after the surgical procedure (perioperative mortality 10.8%). Combined scalp and skull deficiency present a challenging task. An interdisciplinary treatment helps to prevent severe and specialty-specific complications, such as hydrocephalus. We therefore recommend a close neurological observation after reconstructive treatment with focus on symptoms of CSF disturbances.

The impact of intraoperative frozen section analysis on final resection margin status, recurrence, and patient outcome with oral squamous cell carcinoma.

BACKGROUND: The objective of this study was to evaluate the diagnostic value of intraoperative frozen section analysis (IFSA) of tumor bed margins in patients with oral squamous cell carcinoma (OSCC). METHODS: This retrospective study includes 194 primary OSCC cases. The impact of intraoperative information by IFSA on final margin status, local recurrence, and disease-specific survival were analyzed. RESULTS: IFSA revealed a 50% sensitivity and a 100% specificity, with a positive and negative predictive value of 100% and 89.1%, respectively. In 19 cases, margins were rated positive by IFSA and remained positive in eight cases (42.1%), despite immediate re-resection. This constellation led to higher recurrence and lower survival rates than in cases with consecutive R0 status (each p = 0.046). Positive margins in IFSA were associated with closer final margins (p = 0.022) and early recurrences (p = 0.050). CONCLUSIONS: Achieving instant R0 status has a crucial impact on disease recurrence and patient survival. IFSA falls short to ensure secure definite surgical margins. Thus, improved intraoperative diagnostic information on the location and extent of OSCC could support patient treatment. CLINICAL RELEVANCE: Considering that patient survival has not improved despite progress in surgical and adjuvant therapy, the process and outcome of IFSA was scrutinized as one part of the treatment concept.

Retrospective analysis of complications in 190 mandibular resections and simultaneous reconstructions with free fibula flap, iliac crest flap or reconstruction plate: a comparative single centre study.

OBJECTIVES: The purpose of this study was to evaluate the incidence of complications following mandibular reconstruction and to analyse possible contributing factors. MATERIALS AND METHODS: Clinical data and computed tomography scans of all patients who needed a mandibular reconstruction with a reconstruction plate, free fibula flap (FFF) or iliac crest (DCIA) flap between August 2010 and August 2015 were retrospectively analysed. RESULTS: One hundred and ninety patients were enrolled, encompassing 77 reconstructions with reconstruction plate, 89 reconstructions with FFF and 24 reconstructions with DCIA flaps. Cutaneous perforation was most frequently detected in the plate subgroup within the early interval and overall (each p = 0.004). Low body mass index (BMI) and total radiation dosage were the most relevant risk factors for the development of analysed complications. CONCLUSIONS: Microvascular bone flaps have overall less skin perforation than reconstruction plates. BMI and expected total radiation dosage have to be respected in choice of reconstructive technique. CLINICAL RELEVANCE: A treatment algorithm for mandibular reconstructions on the basis of our results is presented.

NAM-help or burden? Intercultural evaluation of parental stress caused by nasoalveolar molding: a retrospective multi-center study.

OBJECTIVES: Nasoalveolar molding (NAM) was developed to facilitate easier treatment and better outcomes for cleft lip and palate (CLP) patients. The aim of this study was to investigate the parental burden and possible intercultural differences of this treatment modality, which is often argued to burden parents to an extraordinary amount. MATERIALS AND METHODS: Standardized questionnaires (available in English, Mandarin, and German) with 15 non-specific and 14 NAM-specific items to be retrospectively answered by Likert scales by parents of unilateral CLP patients with completed NAM treatment. RESULTS: The parents of 117 patients from two treatment centers in Taiwan and Germany were included. A very high level of overall satisfaction was found in both countries with significant intercultural differences in prenatal parent information, feeding problems, dealing with 3rd party's perception, and experienced personal effort. CONCLUSION: NAM is an effective treatment tool for children's CLP deformities and their caregivers in overcoming the feeling of helplessness. Intercultural differences may be due to infrastructural reasons, cultural attitudes and habits, or different public medical education. CLINICAL RELEVANCE: In addition to facilitating easier surgical treatment, NAM can be seen as a powerful coping strategy for parents dealing with a CLP deformity of their child and does not seem to burden them extraordinarily.

MRI of the inferior alveolar nerve and lingual nerve-anatomical variation and morphometric benchmark values of nerve diameters in healthy subjects.

OBJECTIVE: Since MRI using dedicated imaging sequences has recently shown promising results in direct visualization of the inferior alveolar nerve (IAN) and the lingual nerve (LN) with high spatial resolution, the aim of this study was to generate suitable standard specifications to reliably depict the IAN and LN in MRI and to delineate the anatomy and its variants of these nerves in healthy subjects. METHODS: Thirty healthy volunteers were examined on a 3-T scanner (Elition, Philips Healthcare, Best, the Netherlands). The sequence protocol consisted of 3D STIR, 3D DESS, and 3D T1 FFE "black bone" sequences. RESULTS: The study reconfirmed a good feasibility of direct visualization of proximal and peripheral portions of the IAN and of the proximal course of the LN. The STIR sequence showed the highest apparent signal to noise ratio (aSNR) and best apparent nerve-muscle contrast to noise ratio (aNMCNR) for IAN and for the LN. The applied MRI sequences allowed to differentiate the tissue composition of the neurovascular bundle inside the mandibular canal. CONCLUSION: Dedicated MRI sequence protocols proved effectively to detect the IAN and LN and their course in healthy volunteers. The tissue composition of the mandibular neurovascular bundle was conclusively distinguishable as was the varying topography inside multiple bony channels. CLINICAL RELEVANCE: The presented data on the precise and valid visualization of the IAN and LN have clinical implications in respect to local anesthesia prior to dental treatments in the mandible but also regarding surgical procedures and implant insertion in the molar region.

Alterations in Surgically Created Intimal Lesions: An Observation Study in the Aortic Rat Model.

BACKGROUND: Intimal injury in microvessels due to common risk factors such as atherosclerosis or inadequate manipulation are known to have a major impact on developing thrombosis and eventually vascular obstruction. Understanding of these injuries is therefore of great significance to prevent far-reaching consequences such as flap loss in free tissue transfer. It was the aim of this study to evaluate artificially induced intimal lesions with focus on alteration in size and configuration. METHODS: Intimal defects were created surgically in the abdominal aorta of 30 male Wistar rats. After planimetric measurement of the defect sizes, configuration of defects were classified as round, horizontal, or vertical. Seven days postoperatively, the rats underwent a second-look surgery. Finally, the abdominal aorta was harvested, and the endothelial defects were reevaluated concerning size and configuration using a defined pattern. RESULTS: The mean defect size created intraoperatively was 1.68 ± 0.6 mm2. The classification of the defects configurations resulted in 43.3% round, 20% horizontal, and 36.7% vertical defects. Reevaluation at 7 days after surgery showed defect shrinkage in 96.7% in total and 42.8% averaging due to reendothelialization. A shift in defect configuration was detected in 56.7%, the strongest being in vertical defect configurations (100%). Vascular occlusion did not occur in any of the specimen. CONCLUSION: Intimal injuries undergo a fast repair process in terms of size reduction and configuration modification due to reendothelialization. Especially vertical defects, representing a great risk for thrombus formation, convert into lower risk horizontal defect configurations. In high-flow vessels such as the rat aortas, small endothelial damage seems to have no significant impact to produce complete vascular occlusion. Still, all efforts should be made to avoid any kind of intimal injury.

Comparison between Different Perforator Imaging Modalities for the Anterolateral Thigh Perforator Flap Transfer: A Prospective Study.

BACKGROUND: Perforator imaging is routinely performed before perforator flap harvest. Hand-held Doppler (hhD) and color duplex ultrasonography (CDU) are currently the most popular radiation-free methods for this purpose that can be applied by the surgeon alone. The aim of this study was to compare the accuracy, reliability, and feasibility of hhD and CDU with indocyanine green angiography (ICGA) in the anterolateral thigh perforator flap (ALTPF). METHODS: All consecutive ALTPF procedures between May 2017 and April 2018 were included in this prospective study. The perforators were visualized by three investigators independently and randomized, applying hhD, CDU, and ICGA. The presence and the distance to the identified perforator were registered. Further, body mass index (BMI), American Society of Anesthesiologists-status, and the patient's history regarding smoking, alcohol use, and diabetes mellitus were registered alongside gender and age to analyze possible confounders. RESULTS: A total of 12 patients were enrolled with a median age of 67 (52-87) years. In total, 30 perforators were detected intraoperatively as well as with the ICGA. The latter visualized the perforators significantly more precisely than hhD and CDU (p < 0.001 and p = 0.001). The sensitivity and positive predictive value were 67 and 62% for hhD, 73 and 64% for CDU, and 100 and 100% for ICGA, respectively. CONCLUSION: According to this study, ICGA visualized perforators more accurately than the standard methods hhD and CDU. Further, it was associated with the highest sensitivity and positive predictive value. ICGA consistently delivered excellent results, whereas hhD and CDU showed variability.

Effect of Segment Length and Number of Osteotomy Sites on Cancellous Bone Perfusion in Free Fibula Flaps.

BACKGROUND: Indocyanine green (ICG) videoangiography is routinely used to evaluate skin and organ perfusion and to assess patency rates of microvascular anastomoses. This study uses ICG angiography as a novel approach to qualitatively and quantitatively evaluate bone perfusion of microvascular fibula grafts intraoperatively and to assess the effect of fibula segment length and number of osteotomies on bone perfusion. METHODS: All patients planned for mandible reconstruction using a microvascular fibula graft between January 2013 and May 2017 were considered for this study. ICG videoangiography of cancellous bone perfusion was performed using a handheld ICG camera. Videos were analyzed, and a perfusion curve was generated. Peak enhancement, time to peak, slope, and wash-in area under the curve were extracted; rise time, wash-in rate (WiR), and wash-in perfusion index were calculated. Results were statistically analyzed with regard to distal fibula segment length and number of osteotomy sites. RESULTS: Thirty-nine patients (age 59 ± 8 years) were included in the study. Mandible reconstruction was achieved with 1 (n = 15), 2 (n = 13), or 3 (n = 11) fibula segments. The WiR was 6.4 ± 2.3 and 4.4 ± 0.2 before and after proximal osteotomy, respectively. The wash-in perfusion index was 114.2 ± 48.4 before and 84.4 ± 20.0 after proximal osteotomy. Bone perfusion was significantly reduced after additional proximal osteotomies. Both the segment length and number of proximal osteotomies correlated with bone perfusion, with longer segments and fewer osteotomies showing higher perfusion. CONCLUSION: This study demonstrates the feasibility of cancellous bone perfusion analysis using ICG and can serve as a basis for future bone perfusion studies. Additional osteotomies and short segment length negatively affects cancellous bone perfusion of the distal fibula segment in free fibula flaps. The extent to which the observed decrease in arterial inflow to the distal fibula segment affects the further course of healing needs to be addressed in future studies.

Indocyanine green videoangiography-assisted prediction of flap necrosis in the rat epigastric flap using the flow® 800 tool.

BACKGROUND: The decision to re-operate on a potentially ischemic free flap remains challenging. Indocyanine green videoangiography (ICG) with the FLOW® 800 tool is a method which allows an immediate qualitative conclusion about the patency of an anastomosis. Is it also able to predict the outcome of potentially compromised vascular free flaps? MATERIALS AND METHODS: An epigastric flap was raised and repositioned in 79 rats. Intraoperative fluorescence angiography was performed using ICG videoangiography and the FLOW® 800 tool was applied. Six regions of interest were positioned systematically over the flap, changes of the ICG fluorescence were color coded with respect to time and 474 measurements were performed. The flap was clinically monitored for one week and the resulting necrotic areas were correlated with the ICG/FLOW® 800 results. RESULTS: Mean intensity of clinically vital areas was 83.39 ± 50.96 arbitrary units (AU) and 37.33 ± 15.14 AU in necrotic areas. The receiver operating characteristic curve and Youden-Index analysis revealed that the optimal cutoff for the maximal intensity of ICG after FLOW® 800 analysis was ≤ 61.733 for the prediction of flap necrosis and > 61.733 for the prediction of flap survival (P < 0.0001; 95% CI = 0.85-0.91; Youden-Index: 0.67). The maximal intensity of ICG angiography had a specificity of 96.1% and sensitivity of 71.4%. The positive predictive value was 97.46% and the corresponding negative predictive value was 61.34%. CONCLUSION: This demonstrates the potential additional value of ICG videoangiography including FLOW® 800 analyses in the postoperative monitoring of transplanted flaps. © 2016 Wiley Periodicals, Inc. Microsurgery 37:235-242, 2017.

A prospective longitudinal study of postnatal dentoalveolar and palatal growth: The anatomical basis for CAD/CAM-assisted production of cleft-lip-palate feeding plates.

This study describes the dentoalveolar and palatal growth during the first months of life. Knowledge concerning this development is essential to avoid unwanted events such as mucosal ulcerations or restriction of growth when cleft-lip and palate (CLP) patients are treated. The results involve the generation of CAD/CAM CLP-feeding plates. Intraoral impressions from 32 healthy newborns were taken monthly for 5 months, supplemented by measurements of body weight, length, and occipital-frontal head circumference. The casts were digitalized, and two observers manually selected defined anatomical landmarks on virtual 3-D models. The distances between these landmarks were evaluted. Statistical analysis included an inter-rater agreement analysis and the determination of growth. In total, 213 casts were analyzed, with 65 models excluded because of inaccuracies in impression-taking or cast production. Overall longitudinal growth was 20.3%, whereas transversal growth reached a maximum of 21.1%. Vertical growth was 32.4% at the tuberal level. On the basis of these results, a semiautomated series of feeding plates allowing for monthly expansion could be generated. The acquired data serve as a useful reference for other pediatric and orthofacial investigations and treatments. One such application is the automated, fully virtual manufacture of CLP-feeding plates based on only one impression-taking. Our data reveal when caution is needed to prevent ulceration. The series of plates generated can minimize the time-consuming impression-taking and the production of further plaster models. The method of measurement is suitable for documentary purposes. Clin. Anat. 30:846-854, 2017. © 2017 Wiley Periodicals, Inc.

Form and Size Matter: Increased Risk of Thrombosis in Microvessels with Surgically Created Endothelial Lesions.

Background Atherosclerosis is a known risk factor for flap loss in microsurgery. Several microsurgical techniques, like plaque removal, have been proposed for atherosclerotic vessels, but these techniques often induce intimal injuries. The aim of this study was to investigate the impact of various endothelial defects on the risk of thrombosis in a rat acute intimal injury model. Methods Endothelial defects of various forms and sizes were created in the abdominal aorta of 30 male Wistar rats following a strict protocol. Defect sizes were measured and classified as round, horizontal, or vertical based on their configuration. An hour after reestablishing the blood flow, the abdominal aorta was harvested and the operation site was assessed for signs of thrombosis clinically and using light microscopy. Univariate and multiple linear regression analysis were performed to identify possible influencing factors on thrombosis. Results The mean defect size was 2.65 ± 1.19 mm2. Intimal lesions were classified as round in 36.7%, horizontal in 33.3%, and vertical in 30% of specimens. Thrombus formation was detected in 46.7% clinically and in 50% histologically. Univariate regression analysis revealed that defect size (p = 0.048) and vertical form (p = 0.017) were significantly associated with thrombus formation. Multiple regression analysis corroborated vertical defects as a risk factor for thrombosis (p = 0.03). Conclusion Endothelial injuries are associated with a high risk of thrombosis with highest risks associated with vertical defects. Arteries should be carefully examined for intimal defects before microvascular anastomosis, especially in the atherosclerotic patient.

Functional Outcome of CAD/CAM-Assisted versus Conventional Microvascular, Fibular Free Flap Reconstruction of the Mandible: A Retrospective Study of 30 Cases.

Background Different advantages of virtually planned and guided mandibular reconstructions have been described. Functional analyses and comparisons with conventionally reconstructed patients. Methods We retrospectively analyzed 30 cases of mandibular reconstructions that involved virtually planned or conventional microvascular, fibular free flaps that occurred between April 2011 and December 2014 at a single center. The results were also compared with a healthy cohort of 30 participants. Axiographic measurements were performed postoperatively, and uni- and multivariate regressions analyses were performed to determine the association between possible predictor variables on functional outcome. Results Operation time, hospital stay, number of osteotomies, incidence of postoperative temporomandibular joint pain, noise, and tension did not differ significantly between the conventional and computer-aided design/computer-aided manufacturing (CAD/CAM) groups (each p > 0.05). Mouth opening and protrusion and laterotrusion also did not differ significantly (each p > 0.05) but were significantly reduced compared with the healthy group. Univariate analysis showed a significant influence of postoperative irradiation on mouth opening and laterotrusion in the conventional group (p = 0.047 and p = 0.028). In addition, multivariate analysis showed a significant influence of indication and number of osteotomies on laterotrusion (p = 0.005 and p = 0.043). Uni and multivariate analyses revealed a significant influence of indication, preoperative irradiation, and number of osteotomies on protrusion and mouth opening in the CAD/CAM group (p = 0.016, p = 0.044, and p = 0.028). Conclusion CAD/CAM-assisted reconstructions of the mandible give comparable functional results with those of the conventional technique, but no functional superiority has been established. Nevertheless, the integration of virtual planning and guided surgery is definitely of significant value but should be indicated individually case by case.

The value of perioperative antibiotics on the success of oral free flap reconstructions.

The subject of the presented study was to monitor and compare problems and outcomes of reconstructive surgery with microvascular free flaps in the head and neck region between groups of patients treated with perioperative antibiotics and a group of patients without antibiotics. Patients requiring oral reconstructive surgery following cancer resections with microvascular free flaps were prospectively evaluated (2007-2012). Antibiotic therapy was started 30 min before the operation and administered for 10 days. Three hundred and fifty patients were included (208 male, 59.4%; 142 female, 40.6%; mean age 59.8 ± 13.2 years). 330 patients received perioperative antibiotics. Twenty patients (5.7%) who received no antibiotics for specific reasons served as the control group. Wound infections developed in 33 of 122 patients (27%) who received benzylpenicillin, 17 of 88 patients (19.3%) who received amoxicillin combined with sulbactam and 25 of 120 patients (20.8%) who received cefuroxime. Ten patients (50%) who did not receive antibiotics developed wound infections. Receiving no antibiotics or penicillin showed no benefit (P = 0.11). Those receiving cefuroxime showed significantly lower incidence of wound infections (P = 0.034; risk decreased by the factor 2.88). The use of amoxicillin combined with sulbactam showed the lowest rate of wound infections (P = 0.018; risk decreased by the factor 3.46). The use of amoxicillin combined with sulbactam appears to be the most appropriate prophylactic antibiotic followed by cefuroxime in oral microsurgical free flap reconstructions. These data may serve as a guide until a controlled multicenter prospective trial is performed comparing newer antibiotics against current standards.

Ketamine-Xylazine Anesthesia in Rats: Intraperitoneal versus Intravenous Administration Using a Microsurgical Femoral Vein Access.

BACKGROUND: Ketamine-xylazine is a frequently used combination for anesthesia in microsurgically operated rats and can be administered by intraperitoneal (IP) or intravenous (IV) injection. Both methods are associated with relatively high misadministration rates. In the present study, we want to introduce a femoral vein access that requires microsurgical cannulation but enables a 100% administration rate. METHODS: In this study, the maximal time of anesthesia was analyzed, time to response, latency time, and the total need for anesthetic agents in IP (n = 200) and IV (n = 40) anesthesia in Wistar rats for the purpose of microvascular operations. IV injections were achieved with an inserted microcatheter that was applied via a microsurgical femoral vein access. RESULTS: The time needed for the placement of the microcatheter was 5.76 ± 0.89 minutes. Maximal time of anesthesia (IP vs. IV) was 7.02 ± 1.92 versus 21.78 ± 5.77 hours (p < 0.0001), time to response was 137.5 ± 3.91 versus 18 ± 2.18 seconds (p < 0.0001), latency time 35.53 ± 3.21 versus 27.8 ± 2.88 minutes (p < 0.0001), and total volume of anesthetic 1.42 ± 0.39 versus 2.78 ± 0.73 mL (p < 0.0001), respectively. CONCLUSION: IV administration using the microsurgical femoral vein access is a feasible method with a quicker response rate and a 100% administration rate. Furthermore, it enables longer anesthesia, for example, complex microsurgical or other experimental procedures in the rat.

Incidence and outcome for patients with occult lymph node involvement in T1 and T2 oral squamous cell carcinoma: a prospective study.

BACKGROUND: The evidence base to inform the decision making process in patients with early stage oral cancer and a clinical and radiological N0 neck remains insufficient to answer the question when it is safe to "watch and wait" and when to proceed with a selective neck dissection. METHODS: A total of 327 consecutive cases of histopathologically staged T1-2, N0-1 and M0, but clinically N0, squamous cell carcinoma of the tongue were prospectively analysed. Univariate and multivariate analyses were used for statistical analysis and are represented as Kaplan-Meier analyses or Cox proportional hazard regression analysis. RESULTS: In 61 patients (18.65%) lymph node involvement was found in the histopathological processing. The mean survival of all patients was 73.3 ± 48.6 months. The 2-year and 5-year overall survival rates of all patients were 87.5% and 68.4%, respectively. The 2-year and 5-year survival rates for stage N0 were 89.1% and 70.7% compared to 83.3% and 62.9% in N1 situations. The 2-year and 5-year survival rates for stage T1 were 87.9% and 73.6% compared to 87.2% and 65.3% in stage T2, respectively. The time to recurrence in stage N0 was 35.1 ± 30.5 months compared to 25.63 ± 24.6 months in cases with N1 disease. Stage T1 was associated with a time to recurrence of 38.1 ± 33.9 months compared with 27.2 ± 22.7 months in patients classified T2.Variables found to be strongly associated with survival in the univariate analysis included older age, higher tumour and N stage, and grading. Age, tumour stage (p = 0.011, 95% CI, 1.09 to 2.0), nodal stage (p = 0.038, 95% CI, 1.02 to 2.07), and recurrence were independently and significantly associated with survival in the multivariate analysis. CONCLUSIONS: This confirms a high overall disease free survival for patients with T1 and N0 treated with single modality surgery and in common with the literature confirms the poor impact on prognosis of the N positive neck.