Evidence-Based Approaches to Anticoagulation in Reconstructive Microsurgery-A Systematic Literature Review.

This systematic review addresses the crucial role of anticoagulation in microsurgical procedures, focusing on free flap reconstruction and replantation surgeries. The objective was to balance the prevention of thrombotic complications commonly leading to flap failure, with the risk of increased bleeding complications associated with anticoagulant use. A meticulous PubMed literature search following Evidence-Based-Practice principles yielded 79 relevant articles, including both clinical and animal studies. The full-texts were carefully reviewed and evaluated by the modified Coleman methodology score. Clinical studies revealed diverse perioperative regimens, primarily based on aspirin, heparin, and dextran. Meta-analyses demonstrated similar flap loss rates with heparin or aspirin. High doses of dalteparin or heparin, however, correlated with higher flap loss rates than low dose administration. Use of dextran is not recommended due to severe systemic complications. In animal studies, systemic heparin administration showed predominantly favorable results, while topical application and intraluminal irrigation consistently exhibited significant benefits in flap survival. The insights from this conducted systematic review serve as a foundational pillar towards the establishment of evidence-based guidelines for anticoagulation in microsurgery. An average Coleman score of 55 (maximum 103), indicating low overall study quality, however, emphasizes the need for large multi-institutional, randomized-clinical trials as the next vital step.

The masseteric nerve for facial reanimation: Macroscopic and histomorphometric characteristics in 106 human cadavers and comparison of axonal ratio with recipient nerves.

Peripheral facial palsy causes severe impairments. Sufficient axonal load is critical for adequate functional outcomes in reanimation procedures. The aim of our study was to attain a better understanding of the anatomy of the masseteric nerve as a donor, in order to optimize neurotization procedures. Biopsies were obtained from 106 hemifaces of fresh frozen human cadavers. Histological cross-sections were fixed, stained with PPD, and digitized. Histomorphometry and a validated software-based axon quantification were conducted. Of the 154 evaluated branches, 74 specimens were of the main trunk (MT), 40 of the anterior branch (AB), and 38 of the descending branch (DB), while two halves of one cadaver featured an additional branch. The MT showed a diameter of 1.4 ± 0.41 mm (n = 74) with 2213 ± 957 axons (n = 55). The AB diameter was 0.9 ± 0.33 mm (n = 40) with 725 ± 714 axons (n = 30). The DB diameter was 1.15 ± 0.34 mm (n = 380) with 1562 ± 926 axons (n = 30). The DB demonstrated a high axonal capacity - valuable for nerve transfers or muscle transplants. Our findings should facilitate a balanced selection of axonal load, and are potentially helpful in achieving more predictable results while preserving masseter muscle function.

Histomorphometry of the Sural Nerve for Use as a CFNG in Facial Reanimation Procedures.

Facial palsy (FP) is a debilitating nerve pathology. Cross Face Nerve Grafting (CFNG) describes a surgical technique that uses nerve grafts to reanimate the paralyzed face. The sural nerve has been shown to be a reliable nerve graft with little donor side morbidity. Therefore, we aimed to investigate the microanatomy of the sural nerve. Biopsies were obtained from 15 FP patients who underwent CFNG using sural nerve grafts. Histological cross-sections were fixated, stained with PPD, and digitized. Histomorphometry and a validated software-based axon quantification were conducted. The median age of the operated patients was 37 years (5-62 years). There was a significant difference in axonal capacity decrease towards the periphery when comparing proximal vs. distal biopsies (p = 0.047), while the side of nerve harvest showed no significant differences in nerve caliber (proximal p = 0.253, distal p = 0.506) and axonal capacity for proximal and distal biopsies (proximal p = 0.414, distal p = 0.922). Age did not correlate with axonal capacity (proximal: R = -0.201, p = 0.603; distal: R = 0.317, p = 0.292). These novel insights into the microanatomy of the sural nerve may help refine CFNG techniques and individualize FP patient treatment plans, ultimately improving overall patient outcomes.

Precise Monitoring of Returning Sensation in Digital-Nerve Lesions by Three-Dimensional Imaging: A Proof-of-Concept Study.

SUMMARY: Digital-nerve lesions result in a loss of tactile sensation reflected by an anesthetic area (AA) at the radial or ulnar aspect of the respective digit. Available tools to monitor the recovery of tactile sense have been criticized for their lack of validity. Precise quantification of AA dynamics by three-dimensional (3D) imaging could serve as an accurate surrogate to monitor recovery after digital-nerve repair. For validation, AAs were marked on digits of healthy volunteers to simulate the AA of an impaired cutaneous innervation. The 3D models were composed from raw images that had been acquired with a 3D camera to precisely quantify relative AA for each digit (3D models, n = 80). Operator properties varied with regard to individual experience in 3D imaging and image processing. In addition, the concept was applied in a clinical case study. Results showed that images taken by experienced photographers were rated as better quality ( P < 0.001) and needed less processing time ( P = 0.020). Quantification of the relative AA was not altered significantly, regardless of experience level of the photographer ( P = 0.425) or image assembler ( P = 0.749). The proposed concept allows precise and reliable surface quantification of digits and can be performed consistently without relevant distortion by lack of examiner experience. Routine 3D imaging of the AA has the great potential to provide visual evidence of various returning states of sensation and to convert sensory nerve recovery into a metric variable with high responsiveness to temporal progress.

Objectifying the Role of the Depressor Anguli Oris Muscle Using High-Resolution Ultrasound: A Prospective Study.

BACKGROUND: In the setting of facial palsy, synkinesis of the depressor anguli oris (DAO) muscle is a common pathology, impairing dynamic and resting facial symmetry.In this prospective study, the authors used high-resolution ultrasound (HRUS) to evaluate the morphologic features of DAO and to quantify bilateral differences in DAO cross-sectional diameter (CSD) in individuals with unilateral synkinesis. METHODS: From June of 2020 to May of 2021, 30 patients (19 women, 11 men) with clinically diagnosed unilateral synkinesis underwent evaluation with HRUS. DAO CSD was measured bilaterally, 1 cm inferior to the modiolus, in both the resting and smiling positions. RESULTS: The Sunnybrook Facial Grading System Synkinesis Score was 6.20 ± 2.48 (range, 0 to 10). DAO CSD at rest measured 2.41 ± 0.67 mm (range, 1.40 to 4.00 mm) on the control side and 2.66 ± 0.98 mm (range, 1.60 to 5.10 mm) on the affected side. On the control side, DAO CSD was reduced by -0.19 ± 0.43 mm (range, -1.10 to 1.12 mm) during smiling. In contrast, the synkinetic DAO CSD increased by 0.64 ± 0.38 mm (range, 0.00 to 1.59 mm) ( P < 0.001) with animation. The pattern of increased CSD in synkinetic DAO muscles and decreased or unchanged CSD on the control side during smiling was identified in 70% of patients. CONCLUSIONS: HRUS demonstrates increased CSD in synkinetic DAO muscles during active smiling. The opposite is true for DAO muscles on the control side, which exhibit decreased CSD with animation. HRUS can be performed preoperatively to objectify DAO dysfunction and guide targeted therapy. CLINICAL QUESTION/LEVEL OF EVIDENCE: Diagnostic, IV.

Standard doses of Triamcinolone do not affect fibroblast cell migration of abdominoplasty patients in-vitro1.

BACKGROUND: Recent studies have demonstrated that local application of corticosteroids reduces wound exudation following abdominoplasty and other reconstructive surgical procedures. On the other hand, corticosteroids might provoke wound healing disturbances due to their immunosuppressive effects. OBJECTIVE: The main objective of this study was to gain further information about the impact of the corticosteroid triamcinolone on cell migration in abdominoplasty patients. METHODS: An in-vitro scratch assay wound healing model was applied to observe cell migration of fibroblasts cultured with nutrient medium containing human seroma aspirate±triamcinolone. RESULTS: There were no significant differences regarding cell migration when fibroblasts were incubated with triamcinolone + seroma containing culture medium compared to seroma containing culture medium without triamcinolone. CONCLUSIONS: The performed in-vitro study suggests that triamcinolone does not decelerate fibroblast cell migration which is considered as a surrogate of wound healing.

Using High-Resolution Ultrasound to Assess Post-Facial Paralysis Synkinesis-Machine Settings and Technical Aspects for Facial Surgeons.

BACKGROUND: Synkinesis of the facial musculature is a detrimental sequalae in post-paralytic facial palsy (PPFP) patients. Detailed knowledge on the technical requirements and device properties in a high-resolution ultrasound (HRUS) examination is mandatory for a reliable facial muscle assessment in PPFP patients. We therefore aimed to outline the key steps in a HRUS examination and extract an optimized workflow schema. METHODS: From December 2020 to April 2021, 20 patients with unilateral synkinesis underwent HRUS. All HRUS examinations were performed by the first author using US devices with linear multifrequency transducers of 4-18 MHz, including a LOGIQ E9 and a LOGIQ S7 XDclear (GE Healthcare; Milwaukee, WI, USA), as well as Philips Affinity 50G (Philips Health Systems; Eindhoven, the Netherlands). RESULTS: Higher-frequency and multifrequency linear probes ≥15 MHz provided superior imaging qualities. The selection of the preset program Small Parts, Breast or Thyroid was linked with a more detailed contrast of the imaging morphology of facial tissue layers. Frequency (Frq) = 15 MHz, Gain (Gn) = 25-35 db, Depth (D) = 1-1.5 cm, and Focus (F) = 0.5 cm enhanced the image quality and assessability. CONCLUSIONS: An optimized HRUS examination protocol for quantitative and qualitative facial muscle assessments was proposed.

"A-PePSI LIGhT" Assessment Score to Predict Pressure Sore Impaired Healing Late Recurrence, Immobility, Greater Surface, Inhibited Thrombocytes.

BACKGROUND: Complication rates of up to 46 percent are reported following pressure sore surgery. Pressure sore patients often exhibit ineffective postoperative wound healing despite tension-free flap coverage, necessitating surgical revision and prolonged hospitalization. Rather than pressure sore recurrence, such impaired healing reflects a failed progress through the physiologic stages of the normal wound-healing cascade. The principal objective of the study reported here was to elucidate potentially modifiable inherent variables that predict predisposition to impaired healing and to provide a tool for identifying cases at risk for complicated early postoperative recovery following pressure sore reconstruction. METHODS: A retrospective chart review of late-stage (stage 3 or higher) sacral and ischial pressure sore patients who underwent flap reconstruction from 2014 to 2019 was performed. A multivariable logistic regression model was used to identify key patient and operative factors predictive of impaired healing. Furthermore, the Assessment Score to Predict Pressure Sore Impaired Healing (A-PePSI) was established based on the identified risk factors. RESULTS: In a cohort of 121 patients, 36 percent exhibited impaired healing. Of these, 34 patients suffered from dehiscences, necessitating surgical revision. Statistically significant risk factors comprising late recurrence (OR, 3.8), immobility (OR, 12.4), greater surface (>5 cm diameter; OR, 7.3), and inhibited thrombocytes (aspirin monotherapy; OR, 5.7) were combined to formulate a prognostic scoring system (A-PePSI LIGhT). CONCLUSIONS: The A-PePSI LIGhT score serves as a prognostic instrument for assessing individual risk for impaired healing in pressure sore patients. Preoperative risk stratification supports rational decision-making regarding operative candidacy, allows evidence-based patient counseling, and supports the implementation of individualized treatment protocols. . CLINICAL QUESTION/LEVEL OF EVIDENCE: Risk, III.

Microanatomy of the Frontal Branch of the Facial Nerve: The Role of Nerve Caliber and Axonal Capacity.

BACKGROUND: A commonly seen issue in facial palsy patients is brow ptosis caused by paralysis of the frontalis muscle powered by the frontal branch of the facial nerve. Predominantly, static methods are used for correction. Functional restoration concepts include the transfer of the deep temporal branch of the trigeminal nerve and cross-facial nerve grafts. Both techniques can neurotize the original mimic muscles in early cases or power muscle transplants in late cases. Because axonal capacity is particularly important in cross-facial nerve graft procedures, the authors investigated the microanatomical features of the frontal branch to provide the basis for its potential use and to ease intraoperative donor nerve selection. METHODS: Nerve biopsy specimens from 106 fresh-frozen cadaver facial halves were obtained. Histologic processing and digitalization were followed by nerve morphometric analysis and semiautomated axon quantification. RESULTS: The frontal branch showed a median of three fascicles (n = 100; range, one to nine fascicles). A mean axonal capacity of 1191 ± 668 axons (range, 186 to 3539 axons; n = 88) and an average cross-sectional diameter of 1.01 ± 0.26 mm (range, 0.43 to 1.74 mm; n = 67) were noted. In the linear regression model, diameter and axonal capacity demonstrated a positive relation (n = 57; r2 = 0.32; p < 0.001). Based on that equation, a nerve measuring 1 mm is expected to carry 1339 axons. CONCLUSION: The authors' analysis on the microanatomy of the frontal branch could promote clinical use of cross-facial nerve graft procedures in frontalis muscle neurotization and free muscle transplantations.

Local Triamcinolone Treatment Affects Inflammatory Response in Seroma Exudate of Abdominoplasty Patients: A Randomized Controlled Trial.

BACKGROUND: As the leading complication of abdominoplasty, seroma formation might represent an inflammatory process in response to surgical trauma. This prospective randomized trial investigated whether local administration of the antiinflammatory agent triamcinolone could prevent seroma accumulation. METHODS: Weekly and cumulative seroma volumes were compared between the study groups A, B, and C over a 4-week follow-up (group A, with drain, without triamcinolone; group B, without drain, without triamcinolone; group C, without drain, with triamcinolone). Aspirated seroma samples were analyzed by enzyme-linked immunosorbent assay for selective inflammatory mediators. RESULTS: Triamcinolone significantly reduced cumulative seroma volume (n = 60; mA 845 ± SDA 578 ml, mC 236 ± SDC 381 ml, p = 0.001). The most accentuated suppressive effect of triamcinolone was observed shortly after the treatment (week 1) (mA1 616 ± SDA1 457 ml, mB1 153 ± SDB1 161 ml, mC1 22 ± SDC1 44 ml, pA1/C1 < 0.001, pB1/C1 = 0.014). Local triamcinolone administration resulted in a differential concentration of interleukin-6 (IL-6) and matrix metalloproteinase-9 (MMP-9 (week 1) in seroma exudate as measured by enzyme-linked immunosorbent assay (mIL-6A1 1239 ± SDA1 59 pg/ml, mIL-6C1 848 ± SDC1 80 pg/ml, p < 0.001; mMMP-9A1 2343 ± SDA1 484 pg/ml, mMMP-9C1 376 ± SDC1 120 pg/ml, p = 0.001). CONCLUSIONS: Local administration of 80 mg of triamcinolone reduced postabdominoplasty seroma accumulation significantly. Under triamcinolone treatment, suppressed levels of IL-6 and MMP-9 in seroma fluid were observed. Notably, inflammatory marker suppression correlated clinically with a decrease in seroma accumulation. CLINICAL QUESTION/LEVEL OF EVIDENCE: Therapeutic, II.

[Abdominoplasty without closed-suction drains: a randomised controlled trial]. / Verzicht auf Drainagen bei der Abdominoplastik ­ eine randomisiert-kontrollierte Studie.

INTRODUCTION: There is insufficient scientific evidence from randomised controlled trials to support the routine use of closed-suction drains in body contouring procedures. The aim of this study was to evaluate cumulative seroma volume, length of hospital stay and complication rates in abdominoplasty patients without drains in direct comparison with a cohort receiving drains. MATERIAL AND METHODS: Abdominoplasty patients were prospectively randomised in two study groups with (MD) and without (OD) placement of closed-suction drains. Patients with a BMI ≤ 30 kg/m2 undergoing horizontal or combined horizontal/vertical incision abdominoplasty were included. Scarpa's fascia was preserved during dissection. Exclusion criteria comprised simultaneous liposuction, coagulation disorders and ASA score ≥ 3. Cumulative seroma volume over a four-week follow-up period was assessed as the primary outcome measure. Secondary outcome measures were complications requiring surgical revision and length of hospital stay. RESULTS: This trial did not identify a statistically significant difference in cumulative seroma volume between the MD (30/53) and OD (23/53) cohorts in 53 patients (MMD 493 ± SD 407 ml; MOD 459 ± SD 624 ml; p = 0.812). However, a significantly shorter average length of hospital stay was observed in the OD population (MMD 5.1 ± SD 1.4 d; MOD 4.2 ± SD 1.5 d; p = 0.023). Complication rates were equal in both study groups (nMD = 1; nOD = 1). CONCLUSION: The results of this trial do not justify routine placement of closed-suction drains in abdominoplasty procedures (horizontal or combined horizontal/vertical incision) in the pre-obese patient cohort (BMI ≤ 30 kg/m2). Drain placement should be evaluated on an individual patient-specific basis.

Effects of electrostimulation therapy in facial nerve palsy.

Facial palsy (FP) is a functional disorder of the facial nerve involving paralysis of the mimic muscles. According to the principle "time is muscle," early surgical treatment is tremendously important for preserving the mimic musculature if there are no signs of nerve function recovery. In a 49-year-old female patient, even 19 months after onset of FP, successful neurotization was still possible by a V-to-VII nerve transfer and cross-face nerve grafting. Our patient suffered from complete FP after vestibular schwannoma surgery. With continuous application of electrostimulation (ES) therapy, the patient was able to bridge the period between the first onset of FP and neurotization surgery. The significance of ES for mimic musculature preservation in FP patients has not yet been fully clarified. More attention should be paid to this form of therapy in order to preserve the facial musculature, and its benefits should be evaluated in further prospective clinical studies.

Clinical Impact of DIEP Flap Perforator Characteristics - A Prospective Indocyanine Green Fluorescence Imaging Study.

BACKGROUND: The question to what extent perfusion in deep inferior epigastric perforator (DIEP) flaps depends on specific perforator characteristics has been raised. Anatomical studies and previous clinical trials focussing on DIEP flap perfusion resulted in discrepancies. This prospective study investigates how perforator row, number and diameter affect DIEP flap microperfusion via Indocyanine Green (ICG) fluorescence angiography. METHODS: The fractional weight of insufficiently perfused flap tissue in Zone 4 related to the total DIEP flap weight was measured based on ICG fluorescence angiography and defined as Zone 4 %. As a surrogate for overall DIEP flap perfusion, Zone 4 % was assessed according to the row, number and diameter of perforators included in the flap. RESULTS: In 42 unilateral DIEP flap breast reconstructions, neither medial (33.6 ± 14.2 %)/lateral perforator row (29.9 ± 7.5 %, p = 0.683) nor the parameter perforator number (single perforator 31.5 ± 14.4 %, two perforators 30.2 ± 10.2 %, p = 0.727) had a statistically significant effect on flap tissue availability as measured via Zone 4 %. A negative correlative trend between perforator diameter and Zone 4 % (r = -0.096, p = 0.588) was observed. CONCLUSION: Zone 4 % provides a novel method for an objective assessment of DIEP flap perfusion. Medial/lateral row selection and other perforator properties (number, diameter) within the standard ranges, did not affect Zone 4 % as indicated by ICG fluorescence angiography.

The Influence of Pulsed Electromagnetic Field Therapy on Lymphatic Flow During Supermicrosurgery.

Background: The influence of pulsed electromagnetic field therapy (PEMFT) on medium-sized vessels as well as capillary microcirculation is well known. Effects on lymphatic vessels, however, are difficult to visualize and have not been investigated to date. One of the operative treatment options in primary and secondary lymphedemas is lymphovenous anastomoses using supermicrosurgery. To prove patency of the anastomosis, the lymphatic flow is visualized by fluorescence using indocyanine green. The aim of this study was to investigate the influence of PEMFT on the lymphatic microcirculation, and compare it with conventional manual lymphatic drainage (MLD) during supermicrosurgery. Methods and Results: Ten patients with lymphedema were included. Indocyanine green was injected before the operation for intraoperative visualization of the lymphatic vessels using a microscope equipped with an integrated near-infrared illumination system (Zeiss). The PEMFT system (Bio-Electro-Magnetic-Energy Regulation [BEMER]) was used as our standard device during a single 2-minute application period (AP) followed by MLD or vice versa. The mean light intensity in the calibration period (CP) was 46.53 ± 24.3 and 33.41 ± 12.92 for PEMFT and MLD, respectively. During the AP, the mean light intensity changed to 45.61 ± 24.40 for PEMFT and 57.05 ± 18.80 during MLD. This change between CP and AP did not differ significantly for the PEMFT application (p = 0.26), but showed an increase in light intensity during MLD (p < 0.001). Conclusion: We found a light intensity enhancement equivalent to a flow increase during MLD of 78.7% ± 45.7% (range 20%-144%) and no significant difference during the PEMFT application. A single period application of PEMFT did not affect the lymphatic flow.

Significance of the Marginal Mandibular Branch in Relation to Facial Palsy Reconstruction: Assessment of Microanatomy and Macroanatomy Including Axonal Load in 96 Facial Halves.

BACKGROUND: The marginal mandibular branch (MMB) of the facial nerve provides lower lip symmetry apparent during human smile or crying and is mandatory for vocal phonation. In treating facial palsy patients, so far, little attention is directed at the MMB in facial reanimation surgery. However, isolated paralysis may occur congenital, in Bell's palsy or iatrogenic during surgery, prone to its anatomical course. A variety of therapies address symmetry with either weakening of the functional side or reconstruction of the paralyzed side. To further clarify the histoanatomic basis of facial reanimation procedures using nerve transfers, we conducted a human cadaver study examining macroanatomical and microanatomical features of the MMB including its axonal capacity. METHODS: Nerve biopsies of the MMB were available from 96 facial halves. Histological processing, digitalization, nerve morphometry investigation, and semiautomated axonal quantification were performed. Statistical analysis was conducted with P < 0.05 as level of significance. RESULTS: The main branch of 96 specimens contained an average of 3.72 fascicles 1 to 12, and the axonal capacity was 1603 ± 849 (398-5110, n = 85). Differences were found for sex (P = 0.018), not for facial sides (P = 0.687). Diameters were measured with 1130 ± 327 µm (643-2139, n = 79). A significant difference was noted between sexes (P = 0.029), not for facial sides (P = 0.512.) One millimeter in diameter corresponded to 1480 ± 630 axons (n = 71). A number of 900 axons was correlated with 0.97 mm (specificity, 90%; sensitivity, 72%). CONCLUSIONS: Our morphometric results for the MMB provide basic information for further investigations, among dealing with functional reconstructive procedures such as nerve transfers, nerve grafting for direct neurotization or babysitter procedures, and neurectomies to provide ideal power and authenticity.

Anatomical study of the zygomatic and buccal branches of the facial nerve: Application to facial reanimation procedures.

The facial nerve is responsible for any facial expression channeling human emotions. Facial paralysis causes asymmetry, lagophthalmus, oral incontinence, and social limitations. Facial dynamics may be re-established with cross-face-nerve-grafts (CFNG). Our aim was to reappraise the zygomaticobuccal branch system relevant for facial reanimation surgery with respect to anastomoses and crossings. Dissection was performed on 106 facial halves of 53 fresh frozen cadavers. Study endpoints were quantity and relative thickness of branches, correlation to "Zuker's point", interconnection patterns and crossings. Level I and level II branches were classified as relevant for CFNG. Anastomoses and fusion patterns were assessed in both levels. The zygomatic branch showed 2.98 ± 0.86 (range 2-5) twigs at level II and the buccal branch 3.45 ± 0.96 (range 2-5), respectively. In the zygomatic system a single dominant branch was present in 50%, two co-dominant branches in 9% and three in 1%. In 66% of cases a single dominant buccal twig, two co-dominant in 12.6%, and three in 1% of cases were detected. The most inferior zygomatic branch was the most dominant branch (P = 0.003). Using Zuker's point, a facial nerve branch was found within 5 mm in all facial halves. Fusions were detected in 80% of specimens. Two different types of fusion patterns could be identified. Undercrossing of branches was found in 24% at levels I and II. Our study describes facial nerve branch systems relevant for facial reanimation surgery in a three-dimensional relationship of branches to each other. Clin. Anat. 32:480-488, 2019. © 2019 Wiley Periodicals, Inc.