The value of postoperative anticoagulants to improve flap survival in the free radial forearm flap: a systematic review and retrospective multicentre analysis

Survival and infection rates of microvascular free flaps in pediatric mandibular reconstruction: A systematic review and meta-analysis

BACKGROUND

Vascularized free tissue transfer has been established as an effective method in the reconstruction of mandibular defects. However, a limited understanding of its efficacy in pediatric patients persists due to its infrequent presentation. The aim of this study is to systematically consolidate the survival and infection rates of free flaps in pediatric mandibular reconstruction.

METHODS

A systematic literature search was conducted on Ovid Medline, Embase, and Cochrane Library for studies published up to January 2024. We included peer-reviewed studies reporting on survival and infection outcomes associated with free flap mandibular reconstruction in pediatric patients (<18 years). We performed a random-effects meta-analysis with the inverse-variance weighted approach to estimate survival and infection rates. Heterogeneity was assessed by I2, and publication bias was examined using Egger's test.

RESULTS

A total of 26 studies, reporting on 463 free flaps and 439 pediatric patients with a mean age of 10.7 years, were included in our study. Most free flaps originated from the fibula (n = 392/463, 84.7%) and benign tumors were the most common cause for mandibular reconstruction (n = 179/463, 38.7%). The pooled estimate for survival of flaps was 96% (95% CI: 93-97, I2 = 0%), and recipient-site infections were estimated to occur in 9% (95% CI: 6-13, I2 = 0%) of cases. The most common reported complications within the study timeframe were early malocclusion (n = 28/123, 21.4%) and bite abnormalities (18/131, 13.7%).

CONCLUSION

Free tissue transfer for mandibular reconstruction in pediatric patients is effective and safe. Further research is required to explore functionality following mandibular reconstruction in diverse pediatric populations.

Hirudin enhances perforator flap survival: Clinical application report and mechanistic exploration

BACKGROUND AND PURPOSE

Hirudin, a potent anticoagulant, is used in traditional Chinese medicine (TCM) to treat thrombotic conditions and prevent postoperative thrombosis. Coagulation-related vascular complications are a common cause of perforator flaps failure. This study explores hirudin's potential to enhance flap growth by mitigating coagulation-related issues.

MATERIALS AND METHODS

Patients were divided into GroupⅠ(hirudin group) and GroupⅡ(control). Laboratory tests covered red blood cell count (RBC), hematocrit (HCT), platelet count (PLT), monocyte count (MONO), prothrombin time (PT), activated partial thromboplastin time (APTT), fibrinogen (FIB), and D-Dimer. Clinical parameters, including capillary refill time (CRT), flap swelling, and survival status, were evaluated. Animal experiments used Sprague-Dawley (SD) rats to establish random skin flaps. The experimental side received hirudin injection, while the control side received saline. Flaps were photographed to calculate survival rate, and CD31 immunohistochemical (IHC) analysis was performed to calculate microvessel density (MVD).

RESULTS

The study, with 29 patients, found significant CRT differences between groups on postoperative days 2 and 6 (p = 0.027; p = 0.019), favoring GroupⅠ. Swelling severity varied significantly over time; GroupⅡhad more pronounced swelling. GroupⅠshowed superior flap growth with fewer complications, statistically significant (p = 0.033). Specific lab indicators (MONO, PT, and FIB) were significant at certain times. In animal experiments, the experimental side consistently had higher flap survival and slightly increased CD31 expression at various times, with higher MVD on days 2 and 6.

CONCLUSIONS

Hirudin enhances flap survival through diverse mechanisms, supporting its role as a complementary approach in perforator flap surgeries.

Dextran-40 Reduces Partial Flap Failure: A Systematic Review and Meta-analysis for Antithrombotics after Free Flaps

Background

Antithrombotic agents are used after free-flap surgery to prevent thrombus formation and improve flap outcomes. However, the reports vary. Therefore, this meta-analysis aimed to elucidate the need for antithrombotic agents in this context.

Methods

We searched for studies that compared the outcomes of patients undergoing free-flap surgery with or without postoperative antithrombotic agents in the PubMed, Cochrane, and ClinicalTrials.gov databases. The primary outcome was total flap failure, with secondary outcomes including partial flap failure, pedicle thrombosis, and bleeding/hematoma. The relative risks (RRs) of outcomes with or without antithrombotic use were evaluated.

Results

Fifteen studies (n = 6755 cases) were included. Antithrombotic agents did not reduce flap failure or pedicle thrombosis risks but increased bleeding and hematoma risks (RR, 1.535). Subgroup analyses by antiplatelet and anticoagulant use demonstrated results similar to those of antithrombotic use. The RR of bleeding/hematoma was 1.761 and 2.740 in the antiplatelet and anticoagulant groups, respectively. Postoperative dextran-40 administration reduced the risk of partial flap failure, with an RR of 0.535.

Conclusions

Postoperative antithrombotic, antiplatelet, or anticoagulant use did not change the risk of total/partial flap failure or pedicle thrombosis but increased the risk of hematoma/bleeding. Postoperative use of dextran-40 reduced the risk of partial flap failure. Increased intraflap blood flow may decrease the risk of partial flap failure. However, dextran-40 may cause severe pulmonary distress. Further prospective studies are required to evaluate the effects of these agents on thrombus formation, intraflap blood flow, and partial flap failure risk.

Free-flap reconstruction methods in head-and-neck oncologic surgery: A CROSS practice survey of members of the French GETTEC Head-and-Neck Tumor Study Group

OBJECTIVE

To survey practices concerning the use of anticoagulants and antiplatelets in microvascular free-flap reconstruction following oncological surgery of the head and neck.

METHODS

A survey of practices was carried out between September 2022 and March 2023. An online questionnaire was sent to members of the French GETTEC Head-and-Neck Tumor Study Group in all French centers practicing head-and-neck cancer surgery with reconstruction using microvascular free-flaps. The questionnaire asked surgeons about their practices regarding the use of intra- and postoperative anticoagulants and antiplatelets, preoperative management of comorbidities, and prevention of postoperative complications.

RESULTS

Sixty-one percent of the 38 respondents (23/38) used intraoperative intravenous heparin injection, associated to flap irrigation with heparin for 76% of surgeons (29/38) and/or a heparin solution bath for 37% (14/38). Postoperative anticoagulation was used by 95% of surgeons (36/38), and antiplatelets by 40% (15/38). Postoperatively, 40% (15/38) carried out monitoring using an implantable micro-Doppler probe, associated to analysis of clinical characteristics of the flap.

CONCLUSION

Reconstructive surgery using microvascular free-flaps involves numerous factors that can influence success. Prospective studies, particularly concerning the management of anticoagulants, could enable a national consensus on methods for free-flap reconstruction.

Postoperative outcomes of aspirin in microvascular free tissue transfer surgery-A systematic review and meta-analysis

Microvascular free tissue transfer surgery is a frequently used technique for head and neck reconstruction involving anticoagulants, and the present study aimed to analyse the postoperative outcomes of aspirin use in conjunction with this procedure. We searched databases for articles published between 2007 and 2022 on microvascular free tissue transfer surgery using aspirin and assessed them for primary and secondary outcomes. Odds ratios (ORs) and 95 % confidence intervals (CIs) were determined through analyses, followed by constructing a forest plot for complication rates. A total of 617 articles were retrieved from the databases, including 14 original full-text articles. Overall complication rates ranged from 0.7-38 % (95 % CI, 17.85 ± 0.503 (±2.8 %) [17.347-18.353]), while flap survival rates ranged from 95-99.2 % (95 % CI, 96.28 ± 0.0956 (±0.10 %) [96.184-96.376]). Two studies reported similar complication rates of 38 %, the highest among all reported studies. The ORs between the studies for the complications and flap survival rates were 2.614 and 0.722, respectively. Although the complication rates associated with aspirin use were not significantly high among the studies, they cannot be ignored. Flap survival rates were independent of the dose and type of anticoagulants used during surgery.

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.

Versatility and outcomes of lateral arm free flap in head and neck reconstruction: a retrospective case series study of our experiences and innovations

OBJECTIVES

The Lateral Arm Free Flap (LAFF) offers advantageous features like variable thickness and minimal hair growth. LAFF is primarily used in orofacial and pharyngeal reconstructions, with limited reports on tracheal/esophageal applications. Also, the psychological prognosis and quality of life in patients with LAFF reconstruction are lacking.

METHODS

This retrospective case series presents outcomes of LAFF reconstruction for head and neck surgical defects which included 19 patients. The disease type, location of reconstruction, TNM staging, tumor size, chemoradiation status, anxiety, depression, quality of life and detailed perioperative information of the LAFF reconstruction surgery were presented in a descriptive pattern. Subgroup analysis was conducted using Mann-Whitney U and Pearson r test.

RESULTS

All 19 patients (100%) had a viable flap after surgery with 5 (26.3%) of them developed flap-related complication. Patients with oropharyngeal reconstruction were more likely to have lower anxiety and depression score and higher quality of life than those with below-oropharyngeal reconstruction. However, no significant p-value was generated in any subgroup comparison or correlation test. And the application of LAFF in esophageal and tracheal reconstruction was proved to be successful.

CONCLUSIONS

The lateral arm free flap exhibits remarkable versatility and multifunctionality, providing advantageous outcomes in head and neck reconstruction.

LEVEL OF EVIDENCE

Level 4 according to OCEBM.

Post-reconstruction Free Flap Complications After Oral Cancer Ablation

Introduction

Microvascular free flap transfer is considered a standard reconstruction after the ablation of oral cancer. Although the success rate is high, flap complications occasionally occur. This study investigated the reasons for and local factors involved in complications of free flap transfer and explored how to salvage the flaps.

Patients and Methods

The cases of 53 patients who underwent a free flap transfer [radial forearm flaps (n = 36), abdominis musculocutaneous flaps (n = 6), scapular osteocutaneous flaps (n = 10), and fibular osteocutaneous flap (n = 1)] were analyzed: flap complications were observed in five of the cases.

Results

In the all five cases, a salvage operation was performed under general anesthesia. The flap complications occurred within 33 h after anastomosis. In the salvage operation, thrombotic occlusion in veins of flap feeders was observed in three of the five cases. The possible reasons for flap complications were a twisting of the anastomosed vein where two veins were united, pressure to the feeder due to subcutaneous hematoma, and edema of adjacent tissue and/or drain tube; the reason was not clear in one case. The flaps were successfully salvaged in four cases by thrombectomy in veins, release of pressure at the veins, and/or interposition of the vein graft.

Conclusion

Surgeons should pay close attention to the pressure and/or twisting in the feeder as well as the hemostasis in the surgical field, and a salvage operation should be carried out immediately when a flap complication is identified.

Effect of Perioperative Antithrombotics on Head and Neck Microvascular Free Flap Survival After Anastomotic Revision

OBJECTIVE

To determine if antithrombotic therapy improves head and neck microvascular free flap survival following anastomotic revision.

STUDY DESIGN

A retrospective review of all patients with microvascular free tissue transfer to the head and neck between August 2013 and July 2021.

SETTING

Otolaryngology-Head and Neck Surgery Departments at University of Alabama at Birmingham, University of Colorado, and University of California Irvine.

METHODS

Perioperative use of anticoagulation, antiplatelets, intraoperative heparin bolus, tissue plasminogen activator (tPA) and vasopressor use, and leech therapy were collected plus microvascular free flap outcomes. The primary endpoint was free flap failure. Analyses of free flaps that underwent anastomotic revision with or without thrombectomy were performed.

RESULTS

A total of 843 microvascular free flaps were included. The overall rate of flap failure was 4.0% (n = 34). The overall rate of pedicle anastomosis revision (artery, vein, or both) was 5.0% (n = 42) with a failure rate of 47.6% (n = 20) after revision. Anastomotic revision significantly increased the risk of flap failure (odds ratio [OR] 52.68, 95% confidence interval [CI] [23.90, 121.1], p < .0001) especially when both the artery and vein were revised (OR 9.425, 95% CI [2.117, 52.33], p = .005). Free flap failure after the anastomotic revision was not affected by postoperative antiplatelet therapy, postoperative prophylactic anticoagulation, intraoperative heparin bolus, tPA, and therapeutic anticoagulation regardless of which vessels were revised and if a thrombus was identified.

CONCLUSION

In cases of microvascular free tissue transfer pedicle anastomotic revision, the use of antithrombotic therapy does not appear to significantly change free flap survival outcomes.

Aspirin, heparin and ischemia time in microvascular free flap surgery - their influence and an optimal anticoagulation protocol

BACKGROUND

Microvascular surgery has become a standardized technique for reconstruction of large tissue defects in Head and Neck Reconstructive Surgery. However, the main dreaded complications are thrombosis of blood vessels or major bleeding after surgery. Several different anticoagulation protocols have been established in the last decades to overcome these problems with varying degrees of success.

METHODS

Over a period of six years, a standardized anticoagulation protocol including acetylsalicylic acid (ASA) and unfractionated heparin (UFH) for direct intraoperative and postoperative administration was established, optimized and compared to a previously used non-standardized protocol. A total of 178 flap surgeries were included in the development and optimization process of the protocol.

RESULTS

ASA significantly increased the risk of complications when used for longer than 72 h (OR = 2.52; p = 0.002; 95% CI 1.39-4.59). Administration of UFH reduced flap loss (bolus: OR 0.68; p = 0.47; 95% CI 0.24-1.93; continuous UFH administration: OR = 0.61; p = 0.33; 95% CI 0.22-1.66), however doses greater than 500 IU/ h of UFH as continuous infusion increased the risk of complications. Reduction in ischemia time had no effect on the occurrence of complications.

CONCLUSION

Anticoagulation regimes in microvascular surgery can influence the postoperative complication rate. The optimal protocol should consist of a combination of ASA and UFH for the intraoperative and direct postoperative phase. Prolonged administration of ASA as well as doses &gt;500 IU/ h of UFH are to be avoided due to the increased complication rate.

Leech Therapy Protects Free Flaps against Venous Congestion, Thrombus Formation, and Ischemia/Reperfusion Injury: Benefits, Complications, and Contradictions

The use of free cutaneous or myocutaneous flaps in some surgeries, especially in reconstructive surgeries, is routine and imperative; nevertheless, it is controversial because of fear of flap loss due to tissue congestion and partial or complete necrosis. Different mechanisms are discussed in this process, and based on the involved mechanisms, various agents and approaches are suggested for flap salvage. Among these agents and strategies, leech therapy (hirudotherapy) can be a valuable complementary treatment; however, in this way, full attention should be given to all beneficial and harmful aspects to reach the best results. This study included a literature review of the essential complications following free tissue transfer and explained the effects of leech therapy for the respective complications. Based on the review of the literature, the essential complications following free tissue transfer were (I) venous obstruction and congestion, (II) delay in blood flow reestablishment, (III) ischemia/reperfusion injuries, and (IV) thrombus formation. Leech therapy can protect free flaps against the mentioned complications as a complementary treatment. Leech therapy is an appropriate complement, however, not a definite approach for flap salvage. Therefore, in some patients, other alternative methods or even flap removal may be a better option.

A novel negative pressure wound therapy (NPWT) monitoring system for postoperative flap management

Various types of flaps are widely utilized as reconstructive options for patients with soft tissue defects. However, the postoperative monitoring of the flap requires a large amount of time and effort. The aim of this study was to evaluate the efficacy and safety of this novel monitoring procedure using negative pressure wound therapy (NPWT) immediately after the flap operations.A retrospective analysis was performed on patients who underwent free flaps and perforator flaps from March 2019 to December 2020. The flaps were managed by either novel NPWT method or conventional dressing. Among NPWT group, computed tomography angiography was performed in randomly selected 5 flaps on the third postoperative day for evaluation of pedicle compression. Statistical analysis was performed between the 2 groups.A total of 54 flaps were included in this study. Twenty seven flaps were managed using novel NPWT method and 27 flaps were managed using conventional dressing. There was no statistically significant difference in flap survival rates between the 2 groups (P = .91). The patency of flap pedicles in the NPWT group was confirmed by comparing the computed tomography angiography findings. The estimated total flap monitoring time and cost for 5 days was significantly decreased by the application of the novel NPWT monitoring system.Through the application of the novel postoperative monitoring system using NPWT, there is efficient evaluation of the flap. Furthermore, safe flap monitoring is possible with the reduced risk of infection by the avoidance of multiple manual dressing performed in the conventional method.

The Role of von Willebrand Factor in Microvascular Surgery in Severely Injured Patients

Microvascular anastomosis has become a standard surgical technique for reconstruction because of increasing possibilities, indications, and clinical success regarding the survival of the flaps. However, the main dreaded complications exist in thrombosis. Leaving surgical complications aside, systemic problems like disorder of the coagulation-fibrinolysis system are a significant cause of graft loss usually being unrecognized. Reports exist describing a hypercoagulable state with clotting activation and inhibition of fibrinolysis after trauma and delayed surgery considering the secondary homeostasis. In this clinical case, a patient had a large soft tissue defect at the temporal side of the head after severe trauma. After some days of primary stabilization, reconstruction using a free microvascular latissimus dorsi flap was performed. Multiple revisions of the arterial and venous branches had to be performed intraoperatively due to insufficient flap perfusion. After 24 hours, definitive flap loss occurred due to multiple thrombosis in the arterial and venous branches. Postoperative comprehensive coagulation analysis revealed a distinct activation of primary hemostasis with massively increased von Willebrand factor parameters and factor VIII activity as well as acetylsalicylic acid resistance contributing to thrombotic occlusion. In severely injured patients, comprehensive preoperative determination of the coagulation status (especially those of the primary hemostasis) is indispensable before performing free flap reconstruction surgeries to reduce the risk of microvascular flap loss.

Comprehensive Review of the Submental Flap in Head and Neck and Facial Reconstruction: What Plastic Surgeons Need to Know

ABSTRACT

Since its first introduction by Martin and colleagues (1993) and with further revisions by Sterne et al (1996), the submental artery flap (SMAF) has proven to be an effective, reliable, safe, and valuable option in head, neck, and facial reconstructive surgeries. The SMAF utilizes a long pedicle based on the submental artery, a branch of the facial artery, which provides good reach to the lower two-thirds of the face with excellent cosmetic outcomes. It also maintains a good skin color match for facial and cervical defects with a mostly hidden donor site scar (in the majority of cases the donor site can be primarily closed after raising the flap). Although the use of the SMAF is associated with high patient and surgeon satisfaction along with low rates of complications, disadvantages including flap thickness and the hair-bearing nature of the submental skin, which may be problematic for coverage of orofacial defects, especially in male patients. Although it has been almost 30 years since its introduction, and the SMAF has been successfully used in over 500 reported cases of pediatric and adult patients, a comprehensive review of the different aspects of the SMAF is lacking in the medical literature.

Interdisciplinary management of skull base surgery

Skull base surgery remains one of the challenging areas in the field of cranio-maxillofacial surgery, otolaryngology and neurosurgery. Subsequent reconstruction of bone and soft tissue are an essential component to restore function and appearance after ablative surgery. Establishment of interdisciplinary tumor boards with presentation of the individual patient cases have become standard. Multiplanar reconstruction using MRI or CT imaging techniques combined with virtual 3D planning allow precise planning of the procedures. Intraoperative navigation helps for complete resection of malignant findings with safety margins; surgical approaches provide a good overview of the surgical site. Reconstruction using local flaps have a low complication rate with equally reliable results in reconstruction of small tissue defects. Free flap surgery makes reconstruction of large tissue defects possible. Alloplastic materials are alternatively used for reconstruction of bone defects. Based on selected patients, treatment algorithms and standard surgical procedures in extracerebral skull base surgery will be illustrated. Current techniques and new approaches will be discussed with emphasize on hard and soft tissue reconstruction.

Prevention of Venous Thromboembolism in Microvascular Surgery Patients Using Weight-Based Unfractionated Heparin Infusions

BACKGROUND

 Unfractionated heparin infusions are commonly used in microvascular surgery to prevent microvascular thrombosis. Previously, fixed-dose heparin infusions were believed to provide sufficient venous thromboembolism (VTE) prophylaxis; however, we now know that this practice is inadequate for the majority of patients. Anti-factor Xa (aFXa) level is a measure of unfractionated heparin efficacy and safety. This study evaluated the pharmacodynamics of weight-based dose heparin infusions and the impacts of real-time aFXa-guided heparin dose adjustments.

METHODS

 This prospective clinical trial enrolled adult microvascular surgery patients who received a weight-based heparin dose following a microsurgical procedure. Steady-state aFXa levels were monitored, and patients with out-of-range levels received dose adjustments. The study outcomes assessed were aFXa levels at a dose of heparin 10 units/kg/hour, time to adequate aFXa level, number of dose adjustments required to reach in-range aFXa levels, and clinically relevant bleeding and VTE at 90 days.

RESULTS

 Twenty-one patients were prospectively recruited, and usable data were available for twenty patients. Four of twenty patients (20%) had adequate prophylaxis at a heparin dose of 10 units/kg/hour. Among patients who received dose adjustments and achieved in-range aFXa levels, the median number of dose adjustments was 2 and the median weight-based dose was 11 units/kg/hour. The percentage of patients with in-range levels was significantly increased (65 vs. 15%, p = 0.0002) as a result of real-time dose adjustments. The rate of VTE at 90 days was 0%, and clinically relevant bleeding rate at 90 days was 15%.

CONCLUSION

 Weight-based heparin infusions at a rate of 10 units/kg/hour provide a detectable level of anticoagulation for some patients following microsurgical procedures, but most patients require dose adjustment to ensure adequate VTE prophylaxis.

Utility of Viscoelastic Tests to Predict Flap Thrombosis: A Systematic Review

Background:

Flap thrombosis is a rare but devastating complication in microsurgery. Preoperative identification of patients at increased risk for microvascular thrombosis remains challenging. Viscoelastic testing (VET) provides a comprehensive evaluation of the clotting process and can effectively identify hypercoagulability. However, the utility of VET in microvascular reconstruction remains unclear.

Methods:

A systematic review of the association between VET and pedicle thrombosis and free flap loss was performed in accordance with Preferred Reporting Items for Systematic Reviews (PRISMA) guidelines. Identified studies were reviewed independently by two authors for pertinent data.

Results:

Six studies met inclusion criteria. Heterogenous study design and outcome reporting complicated direct comparisons and precluded a formal meta-analysis. Four studies found a statistically significant relationship between VET results and flap thrombosis or flap loss. The maximum clot strength and the fibrinogen-to-platelet ratio (FPR) were key viscoelastic parameters in these studies, both representing a measure of maximal clot strength. Specifically, an elevated FPR (>42%) generated a sensitivity and specificity for flap loss ranging from 57% to 75% and 60% to 82%, respectively. Notably, the negative predictive value for flap failure with a normal preoperative FPR was greater than 90% in all studies reporting a correlation. The remaining two studies reported no predictive value for VET with respect to flap failure or pedicle thrombosis.

Conclusion:

The results of this review suggest that VET, particularly parameters relating to clot strength, may help clinicians identify patients at risk for flap thrombosis. However, uncontrolled and heterogenous reporting limit definitive conclusions, and high-quality diagnostic studies are needed to better determine the clinical utility of viscoelastic testing for free flap patients.

Multidisciplinary Practice Variations of Anti-Thrombotic Strategies for Free Tissue Transfers

Background: Venous thrombosis, the leading cause of free flap failure, may have devastating consequences. Many anti-thrombotic agents and protocols have been described for prophylaxis and treatment of venous thrombosis in free flaps. Methods: National surveys were distributed to microsurgeons (of both Plastics and ENT training) and hematology and thrombosis specialists. Data were collected on routine screening practices, perceived risk factors for flap failure, and pre-, intra-, and post-operative anti-thrombotic strategies. Results: There were 722 surveys distributed with 132 (18%) respondents, consisting of 102 surgeons and 30 hematologists. Sixty-five surgeons and 9 hematologists routinely performed or managed patients with free flaps. The top 3 perceived risk factors for flap failure according to surgeons were medical co-morbidities, past arterial thrombosis, and thrombophilia. Hematologists, however, reported diabetes, smoking, and medical co-morbidities as the most important risk factors. Fifty-four percent of physicians routinely used unfractionated heparin (UFH) or low-molecular-weight heparin (LMWH) as a preoperative agent. Surgeons routinely flushed the flap with heparin (37%), used UFH IV (6%), or both (8%) intra-operatively. Surgeons used a range of post-operative agents such as UFH, LMWH, aspirin, and dextran while hematologists preferred LMWH. There was variation of management strategies if flap thrombosis occurred. Different strategies consisted of changing recipient vessels, UFH IV, flushing the flap, adding post-operative agents, or a combination of strategies. Conclusions: There are diverse practice variations in anti-thrombotic strategies for free tissue transfers and a difference in perceived risk factors for flap failure that may affect patient management.

Free Flap Reconstruction of the Extremities in Patients Who are ≥65 Years Old: A Single-Center Retrospective 1-to-1 Matched Analysis

Purpose

Demographic changes are leading to population aging, and free flap reconstructions for various indications are expected to become increasingly common among older patients. Therefore, this study evaluated free flap reconstruction of the extremities in older patients and compared the outcomes to those from younger patients who underwent similar procedures during the same period.

Patients and Methods

This single-center retrospective study used a case-control design to compare older and younger patients who underwent free flap reconstruction of soft tissue defects in the extremities. One-to-one matching was performed for older patients (≥65 years) and younger patients (≤64 years) according to indication, flap recipient site, and flap type. The parameters of interest were clinico-demographic characteristics, flap type, defect location, indication for free flap reconstruction, number of venous anastomoses, and postoperative complications (flap loss, infection, and wound healing disorders).

Results

The study included 48 older patients and 133 younger patients, with a mean follow-up of 12 months after discharge. The free flap reconstruction was performed at a mean interval of 19.8±22.8 days (range: 0–88 days). The 1:1 matching created 38 pairs of patients, which revealed no significant differences in the rates of flap necrosis and flap failure.

Conclusion

This study failed to detect a significant age-related difference in the flap necrosis rate after free flap reconstruction of extremity defects. Therefore, with careful perioperative management and patient selection, microsurgical free flap reconstruction is a feasible option for older patients.

Comparison Between the Impact of Vasopressors and Goal-Directed Fluid Therapy on the Management of Free Flap Reconstruction of Head and Neck and Monitoring in ICU

Head and neck reconstructions are often accompanied with complex long surgical procedures. Free flap tissue transfer is a standard reconstruction method that reestablishes severe tissue defects after resection due to trauma or cancer. Imbalanced fluid resuscitation can extremely harm the outcome of the flap either due to hypoperfusion or edema. Flap-related postoperative complications mainly flap failure necessitates the administration of a large amount of intravenous fluids perioperatively especially with lengthy operative time. Therefore, vasopressors may be used to preserve hemodynamic stability without excessive fluids use. Nevertheless, these vasopressors have long been disfavored as they may provoke anastomosis vasoconstriction leading to graft hypoperfusion and finally flap failure. However, according to recent guidelines, they are now well-thought to be safe. Of note, inotropes have been confirmed to increase blood flow in the anastomosis hence they can replace vasoconstrictors. Recently, goal-directed fluid therapy (GDFT) has been proven to be excellent in high-risk head and neck free tissue transfer surgery as it decreases prolonged intensive care unit (ICU) admission hospitalization and complication rate. Today, GDFT is highly suggested as one of the enhanced recoveries after surgery protocols for major head and neck free flap reconstruction surgery.

Successful free flap salvage surgery with off-label use of Alteplase: A case report, review of the literature and our free flap salvage algorithm

•

Recombinant tissue-type plasminogen activators help to rescue free flaps; Alteplase.

•

Alteplase is a successful ultima ratio for venous thrombosis.

•

Use of Alteplase must be embedded in a salvage algorithm.

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Salvage algorithm must differentiate between arterial and venous problems.

Introduction

Microvascular free tissue transfer is a technique for reconstruction of large defects in head and neck surgery. Failure due to microvascular thrombosis can lead to microvascular damage or flap loss. Recombinant tissue-type plasminogen activator (Alteplase) is still an off-label use but it can help to rescue free flaps when embedded in a salvage algorithm.

Presentation of case

A 39-year-old patient with received a tumor resection and reconstruction by a radial forearm flap of the left palate. Postoperatively a venous flap thrombosis occurred and immediate surgical revision was done. Initially eperfusion of the flap could not be achieved even after mechanical removal of the thrombus. Then a thrombolysis with Alteplase, which was applied directly into the radial artery, was done. The flap was salvaged and is now completely integrated into the mucosa. Flap salvage procedure was performed according to our free flap salvage algorithm.

Discussion

Thrombolysis with Alteplase for free flap salvage is not a common method. Pedicle thrombosis cannot be predicted. Important procedures during surgical intervention when thrombosis occurs are careful reopening, removal of thrombus, flushing with heparin. Since these procedures failed, surgeons decided to employ Alteplase to optimally rescue the flap.

Conclusion

The present case shows that pharmacological thrombolysis with Alteplase is an effective ultima ratio in free flap salvage with venous thrombosis, although it is still considered offlabel use. Early detection of flap failure and a clear salvage algorithm are important for successful surgical revisions.

Anastomotic Revision in Head and Neck Free Flaps

OBJECTIVES/HYPOTHESIS

Predictors of free tissue transfer (FTT) failure and the need for postoperative revision (POR) have been extensively studied; however, there are little data evaluating outcomes when intraoperative revision (IOR) at initial surgery is required. This study seeks to better understand the impact IOR of the pedicle has on FTT outcomes.

STUDY DESIGN

Retrospective review of 2482 consecutive patients across three tertiary institutions.

METHODS

Adult patients (>18) who received a FTT and underwent anastomotic revision from 2006 to 2019 were included. Logistic regression was performed to predict revision, and recursive partitioning was performed to classify risk of failure based on type of revision and vessels revised.

RESULTS

Failure rates for IOR (19%) and POR (27%) were higher compared to a nonrevised failure rate of 2% (P < .01 and P < .01, respectively). Intraoperative venous revision (IORv, n = 13), arterial (IORa, n = 114), and both (IORb, n = 11) were associated with failure rates of 8% (odds ratio [OR] 3.5, P = .23), 18% (OR = 9.0, P < .01), 45% (OR = 35.3, P = <.01), respectively. Arterial revision was most common among IOR (83%, P < .01). Postoperative venous revision (PORv, n = 35), arterial (PORa, n = 36), and both (PORb, n = 11) were associated with failure rates of 20% (OR = 15.7, P < .01), 27% (OR = 10.6, P < .01), and 39% (OR = 27.0, P < .01), respectively. Failure rate for flaps that had POR after IOR (PORi, n = 11) was 45% (OR = 18.2, P < .01). Diabetes predicted IOR (P = .006); tobacco use, heavy alcohol use, and prior radiation predicted POR (P = .01, P = .05, and P = .01, respectively).

CONCLUSION

Both IOR and POR were associated with increased failure compared to nonrevised flaps. The risk of failure increases sequentially with intraoperative or POR of the vein, artery, or both vessels. Revision of both vessels and POR after IOR are strongly predictive of failure.

LEVEL OF EVIDENCE

3 Laryngoscope, 131:1035-1041, 2021.

Postoperative management of antithrombotic medication in microvascular head and neck reconstruction: a comparative analysis of unfractionated and low-molecular-weight heparin

Purpose

Free flap reconstruction is a valuable technique to preserve function in oncological head and neck surgery. Postoperative graft thrombosis is a dreaded risk. This study aims to compare low-dose unfractionated heparin (UFH) and low-molecular-weight heparin (LMWH) in perioperative thrombosis prophylaxis.

Methods

This is a retrospective analysis of 266 free flaps performed at our academic center. A comparison was made between 2 patient groups, based on their respective postoperative prophylaxis protocols either with UFH (n = 87) or LMWH (n = 179). Primary endpoints were the frequency of transplant thrombosis and the number of flap failures. Secondary endpoints were the occurrence of peri- and postoperative complications.

Results

The flap survival rate was 96.6% and 93.3% for the groups UFH and LMWH, respectively (P = 0.280). The rate of postoperative bleeding requiring revision was 4.6% and 6.7% for each group, respectively (P = 0.498). We found a hematoma formation in 4.6% and 3.9% (P = 0.792).

Conclusion

The free-flap survival rate using low-dose UFH seems to be equivalent to LMWH regimens without compromising the postoperative outcome. Consequently, for risk-adapted thrombosis prophylaxis, either LMWH or UFH can be administrated.

The Effects of Dextran on Postoperative Thrombosis and Hemodilution in Microvascular Head and Neck Reconstruction

BACKGROUND

Free tissue transfer is an integral part of reconstructive head and neck surgery today. Although increased experience and refinements in techniques have minimized flap loss, pharmacological agents have been used to prevent thrombus formation and flap failures, despite their questionable effectiveness. The aim of this study is to investigate the use of dextran 40 in thrombosis prophylaxis, as well as its effects on blood coagulability and flap survival.

METHODS

This is a retrospective analysis of 176 free flaps performed at University Hospital Dubrava, Zagreb, Croatia, during a 4-year period. A comparison was made between 2 patient groups, based on their respective postoperative prophylaxis protocols. All patients were treated with low-molecular-weight heparin as deep vein thrombosis prevention, until patient mobilization. Group 1 was on dextran 40 protocol, whereas group 2 did not receive additional treatment. Primary outcome of the study was determined as flap loss rate, whereas secondary outcome was evaluated as the rate of thrombosis or hemorrhage. The hemodilution potential of dextran 40 was examined through blood count laboratory values.

RESULTS

Total flap survival rate was 90.34%. There were 16 free flap losses and 1 partial loss overall. Anastomoses were re-explored in a total of 27 cases, of which 17 were salvaged. There were 29 events of hemorrhage or arterial or venous thrombosis: 17 in group 1 and 12 in group 2. A sum of 26 incidences of other postoperative complications was recorded, 13 in each group. Hemodilution status showed a statistically significant reduction in erythrocyte count and hemoglobin and hematocrit levels in the group receiving dextran 40, on postoperative days 1 and 3, but no such effect was observed on postoperative platelet count.

CONCLUSIONS

Although dextran 40 has been shown to have a valuable effect on hemodilution, which is beneficial in microsurgery, it did not demonstrate better outcomes in terms of flap survival. Because it can cause serious systemic complications, it is better not to administer it routinely. However, its important influence on reduction in erythrocyte count and hemoglobin and hematocrit levels should be further investigated.

Methodological Quality of Systematic Reviews and Meta-analyses Published in High-Impact Otolaryngology Journals

OBJECTIVE

To assess the methodological quality of intervention-focused systematic reviews (SRs) and meta-analyses (MAs) published in high-impact otolaryngology journals.

DATA SOURCES

Ovid Medline, Embase, and Cochrane Library.

REVIEW METHODS

A comprehensive search was performed for SR and MA citations from 2012 to 2017 in the 10 highest impact factor otolaryngology journals. Abstracts were screened to identify published manuscripts in which the authors indicated clearly that they were performing an SR or MA. Applying a modified typology of reviews, 4 reviewers characterized the review type as SR, MA, or another review type. A simplified version of the AMSTAR 2 (A MeaSurement Tool to Assess systematic Reviews 2) tool was used to assess the reporting and methodological quality of the SRs and MAs that were focused on interventions.

RESULTS

Search and abstract screening generated 499 manuscripts that identified themselves as performing an SR or MA. A substantial number (85/499, 17%) were review types other than SRs or MAs, including 34 (7%) that were literature reviews. In total, 236 SRs and MAs focused on interventions. Over 50% of these SRs and MAs had weaknesses in at least 3 of the 16 items in the AMSTAR 2, and over 40% had weaknesses in at least 2 of the 7 critical domains. Ninety-nine percent of SRs and MAs provided critically low confidence in the results of the reviews.

CONCLUSION

Intervention-focused SRs and MAs published in high-impact otolaryngology journals have important methodological limitations that diminish confidence in the results of these reviews.

Image-Guided Percutaneous Gastrostomy Tube Placement is Safe in Patients Requiring Aspirin 325 mg

RATIONALE AND OBJECTIVES

Requests for gastrostomy tube placement in patients on aspirin (ASA) 325 mg are common, particularly in patients following reconstructive surgery for head and neck cancer, but periprocedural guidelines and recommendations regarding management of high dose aspirin are inconsistent. The purpose of this study was to assess the bleeding risk of percutaneous gastrostomy tube placement in patients on ASA 325 mg.

MATERIALS AND METHODS

This retrospective study of 213 patients who underwent image-guided "push" percutaneous gastrostomy tube placement compared rates of significant bleeding and other secondary outcomes (including all-cause mortality within 30 days, procedure-related mortality, bowel perforation, abdominal abscess, peritonitis, aspiration pneumonia, intraprocedural airway complications, and tube dislodgement) between patients maintained on ASA 325 mg and patients not on antiplatelet or anticoagulation therapy.

RESULTS

No significant bleeding episodes occurred in patients on ASA 325 mg, compared to three episodes in patients not on ASA 325 mg (p = 0.37). A patient in each group had aspiration pneumonia possibly related to tube placement. There were no other notable secondary outcomes, including intraprocedural airway complications in this population with complex head and neck anatomy.

CONCLUSION

These findings suggest that holding ASA 325 mg in patients undergoing percutaneous gastrostomy tube placement is not necessary, especially in patients in whom holding ASA would pose considerable risk. Further multi-institutional longitudinal study is warranted to validate these results.

Controversies in free tissue transfer for head and neck cancer: A review of the literature

BACKGROUND

Microvascular free tissue transfer provides superior functional outcomes when reconstructing head and neck cancer defects. Careful patient selection and surgical planning is necessary to ensure success, as many preoperative, intraoperative, and postoperative patient and technical factors may affect outcome.

AIMS

To provide a concise, yet thorough, review of the current literature regarding free flap patient selection and management for the patient with head and neck.

MATERIALS AND METHODS

PubMed and Cochrane databases were queried for publications pertaining to free tissue transfer management and outcomes.

RESULTS

Malnutrition and tobacco use are modifiable patient factors that negatively impact surgical outcomes. The use of postoperative antiplatelet medications and perioperative antibiotics for greater than 24 hours have not been shown to improve outcomes, although the use of clindamycin alone has been shown to have a higher risk of flap failure. Liberal blood transfusion should be avoided due to higher risk of wound infection and medical complications.

DISCUSSION

There is a wide range of beliefs regarding proper management of patients undergoing free tissue transfer. While there is some data to support these practices, much of the data is conflicting and common practices are often continued out of habit or dogma.

CONCLUSION

Free flap reconstruction remains a highly successful surgery overall despite as many different approaches to patient care as there are free flap surgeons. Close patient monitoring remains a cornerstone of surgical success.

Perioperative considerations in free flap surgery: A review of pressors and anticoagulation

Given the high stakes for microvascular reconstruction, the majority of reconstructive surgeons have developed paradigms for pre, intra, and postoperative management that have proven to result in individual high success rates. Much has been done to identify and avoid perioperative factors that could potentially increase flap failure rates. Two example of this practice has been the generalized use of anticoagulation in free tissue transfer and the prohibition against vasopressor use in patients that are undergoing free tissue transfer. This manuscript will discuss these issues.

Controversies in Microvascular Maxillofacial Reconstruction

The effectiveness and reliability of microvascular reconstruction for large defects in the head and neck is no longer disputed. However, many controversies still persist in the ideal perioperative management of patients undergoing free tissue transfer. The optimal method of postoperative monitoring, the use of vasoconstrictors in the perioperative period, and the use of anticoagulants in the postoperative period remain topics of debate. This article offers recommendations on each of these controversies based on a review of the current literature.

Postoperative anticoagulation after free flap reconstruction for head and neck cancer: A systematic review

OBJECTIVE

Postoperative use of anticoagulation after free tissue transfer in head and neck ablative procedures is common practice, but a clear protocol has not been well established. The outcome measures including total flap failure, thrombosis, and hematoma formation for different anticoagulation regimens in free tissue transfer in the head and neck were reviewed.

DATA SOURCES

PubMed, Ovid, and Cochrane databases were examined for patients who underwent free tissue transfer following head and neck ablative procedures.

REVIEW METHODS

Preferred Reporting Items for Systematic Reviews and Meta-analyses guidelines were utilized to identify English-language studies reporting anticoagulation regimens following free tissue transfer in head and neck ablative procedures. Outcomes included total flap failure, thrombosis, and hematoma formation. Two independent reviewers assessed the quality of the articles by using the Methodological Index for Non-Randomized Studies.

RESULTS

A total of 368 articles were identified. An additional 36 articles were identified through screening of reference lists. Twenty-one of these studies met final inclusion criteria for qualitative analysis. Outcome data on total flap failure, thrombosis, and hematoma formation were extracted and analyzed for comparison against all anticoagulation regimens. Total flap failure, thrombosis, and hematoma formation rates were 4.4%, 4.5%, and 2.2%, respectively. Individual study rates ranged from 0.0% to 10.7%, 0.0% to 10.4%, and 0.6% to 7.2%, respectively.

CONCLUSIONS

There is not adequate evidence to develop a standardized anticoagulation protocol for head and neck free flap procedures. Comparable flap complications were reported between all the employed anticoagulation methods studied, though significant variability in study design among articles existed. Prospective, randomized studies are warranted to determine the optimal postoperative anticoagulation regimen following free tissue transfer of the head and neck. Laryngoscope, 128:412-421, 2018.

Postoperative Controversies in the Management of Free Flap Surgery in the Head and Neck

Free tissue transfer is the gold standard for reconstructing head and neck defects. Free flap success approaches 95% in centers with experience, affording unparalleled ability to restore form and function in cancer, trauma, or other major composite tissue loss. It is critical to manage the perioperative variables that predict success; several areas of controversy have not yet reached consensus. This review focuses on postoperative anticoagulation, fluid management, and flap monitoring methods. These areas of controversy potentially influence flap survival. We review published practices considered within the standard of care, why controversy remains, and future directions to reach standardization.