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.

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.

A Survey of Microvascular Technique Preferences Among American Head Neck Society Members

OBJECTIVE

To identify practices in microvascular techniques in routine and challenging scenarios.

STUDY DESIGN

Cross-sectional study.

METHODS

A national survey addressing practices related to microvascular free flap reconstruction was distributed to AHNS members between October and November 2021.

RESULTS

The respondents encompassed 95 microvascular surgeons. Median years of practice was 6 (interquartile range, 2-13) and median flaps per year was 35 (22-50). Common practices in arterial anastomosis included limited cleaning of artery (84.2%), use of a double approximating clamp (64.2%), and use of interrupted suture (88.4%). Common practices in venous anastomosis included limited cleaning (89.5%), downsizing the coupler (53.7%), and coupling to two independent venous systems (47.4%). In arterial anastomosis, respondents felt that kinking (50.5%) and tension (24.2%) were the riskiest challenges. Kinking was handled by loose sutures or native tissue/dissolvable biomaterial to orient pedicle. Excess tension was handled by additional dissection. With regards to associated practices, most surgeons perform anastomosis after partial inset (52.6%), give aspirin immediately postoperatively (66.3%), reserve transfusion for hemodynamic instability (69.5%), and utilize intraoperative pressors when needed (72.6%). More senior surgeons reported placing more suture to address leaks (p = 0.004) and perform end to side anastomosis on larger vein in case of venous mismatch (p = 0.012). In cases of tension, higher volume surgeons perform more extensive dissection (p = 0.035) and end to side coupling (p = 0.029).

CONCLUSIONS

This survey of AHNS members indicates patterns of microvascular techniques in routine and challenging scenarios. There exists a variation in approaches amongst surgeons based on volume and practice length.

LEVEL OF EVIDENCE

5 Laryngoscope, 134:1265-1277, 2024.

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.

Extended arc of rotation of Latissimus Dorsi Musculocutaneous Flap providing well-vascularized tissue for reconstruction of complete defects of the sternum: An anatomical study of flap pedicle modification

BACKGROUND

Deep sternal wound infections (DSWI) following cardiothoracic surgery represent a life quality endangering sequelae and may lead to sternal osteomyelitis. Radical debridement followed by Negative Pressure Wound Therapy (NPWT) may achieve infection control, provide angiogenesis, and improve respiratory function. When stable wound conditions have been established a sustainable plastic surgical flap reconstruction should be undertaken.

OBJECTIVE

This study analyses a method to simplify defect coverage with a single Latissimus Dorsi Myocutaneous Flap (LDMF).

METHODS

Preparation of 20 LDMF in ten fresh frozen cadavers was conducted. Surgical steps to increase pedicle length were evaluated. The common surgical preparation of LDMF was compared with additional transection of the Circumflex Scapular Artery (CSA).

RESULTS

Alteration of the surgical preparation of LDMF by sacrificing the CSA may provide highly valuable well-vascularized muscle tissue above the sensitive area of the Xiphisternum. All defects could be completely reconstructed with a single LDMF. The gain in length of flap tissue in the inferior third of the sternum was 3.86±0.9 cm (range 2.2 to 8 cm).

CONCLUSIONS

By sacrificing the CSA in harvesting the LDMF a promising gain in length, perfusion and volume may be achieved to cover big sternal defects with a single flap.

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.

Evidence-based postoperative replantation protocols

Postoperative care is essential to upper extremity replantation success and includes careful and frequent monitoring of the replanted part. During this period, pharmacologic agents such as antithrombotic and anticoagulants may prevent complications such as arterial thrombosis and venous congestion. Dressings and therapy can also impact short- and long-term outcomes following replantation. This article reviews the literature to provide guidance for postoperative protocols following upper extremity replantation.

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.

Chemoprophylaxis and Management of Venous Thromboembolism in Microvascular Surgery

This review aims to highlight the common pharmacological and nonpharmacological interventions utilized for thromboprophylaxis as well as flap salvage in microsurgery. A literature review was conducted in PubMed/National Center for Biotechnology Information, Scopus, Web of Science, and MEDLINE databases. Articles with a focus on thromboprophylaxis in microsurgical procedures spanning head and neck surgery, breast and extremity microvascular reconstruction, deep venous thrombosis/pulmonary embolus in microvascular surgery, and flap thrombosis and salvage were included in this review. The majority of available evidence supports mechanical venous thromboembolism (VTE) prophylaxis in all patients undergoing microsurgery given the presence of multiple risk factors for VTE within this particular patient population. Based on the literature review, addition of VTE chemoprophylactic agents is beneficial and an algorithmic approach to thromboprophylaxis in microsurgery patients and management of patients with thrombosis based on literature review and senior authors' experience is recommended and outlined.

Canadian Trends in Free Flap Management for Microsurgical Lower Limb Reconstruction

Introduction: Free tissue transfers have become a mainstay in lower limb salvage, allowing safe and reliable reconstruction after trauma, tumor extirpation, and complex wounds. The optimal perioperative (PO) management of these flaps remains controversial. This study aims to assess the current state of practice among Canadian microsurgeons. Methods: Sixty-four Canadian microsurgeons were approached to complete an online questionnaire regarding their PO management of fasciocutaneous free flaps used for lower limb reconstruction. Trends in dangling timing and duration, use of venous couplers, compressive garments, thromboprophylaxis, and surgeons' satisfaction with their protocol were assessed. Results: Twenty-eight surgeons responded. Fifty-seven percent did not have a specific mobilization protocol. Dangling was mainly initiated on postoperative days 5 to 6 (44%). The most common protocol duration was 5 to 6 days (43%). The concern for prolonged venous pooling was the main reason for delay of dangling (71%). Compressive garments were placed routinely by 12 surgeons (43%) with 20% starting before dangling, 46% with dangling, and 33% after dangling. Venous couplers were routinely used by 24 surgeons (85.7%). Trends in management were influenced by previous training in 53.6% of cases (vs evidence-based medicine 7.1%). Although 89.3% were satisfied with their approach, 92.8% would consider changing practice if higher-level evidence was available. Conclusions: The majority of Canadian microsurgeons initiate dangling early and utilize venous couplers. However, the use of compressive garments is limited. Trends in management are largely based on personal experience. Nearly all surgeons would consider changing their practice if higher-level evidence was available.

Preoperative Predictors of Free Flap Failure

OBJECTIVE

Microvascular free tissue transfer is an important reconstructive option for defects of the head and neck. The present study aims to identify preoperative patient- and tumor-specific characteristics, laboratory values, and other risk factors associated with early free flap failure.

STUDY DESIGN

Retrospective cohort study of 1070 patients.

SETTING

Head and neck surgical oncology service at a tertiary care center from 2005 to 2019.

METHODS

Demographics, comorbidities, preoperative laboratory values, treatment history, and cancer stage were collected for consecutive patients who underwent free flap reconstruction of the head and neck and experienced early free flap failure (<8 days from surgery).

RESULTS

In 1070 patients, the prevalence of early free flap failure was 3.8% (n = 41). Female sex (odds ratio [OR], 2.58; 95% CI, 1.36-4.99), presence of peripheral vascular disease (OR, 2.78; 95% CI, 1.05-6.57), and elevated preoperative platelet count (OR, 2.67; 95% CI, 1.20-5.47) were independently associated with risk of early free flap failure.

CONCLUSION

Female sex, peripheral vascular disease, and preoperative thrombocytosis are all strong predictors of early free flap failure. This suggests that hypercoagulability and poor vessel quality may predispose patients to flap loss. Patients with elevated platelets or peripheral vascular disease warrant careful reconstructive decision making and close monitoring in the perioperative period.

Does anticoagulation improve outcomes of microvascular free flap reconstruction following head and neck surgery: a systematic review and meta-analysis

The commonest cause of microvascular free flap failure is thrombosis at the anastomosis. Pharmacological antithrombotic therapies have been used to mitigate this risk, but they carry the risk of bleeding and haematoma formation. To justify any intervention, it is necessary to evaluate the benefits and balance of risks. This meta-analysis aims to quantify the value of systemic anticoagulation during head and neck free tissue reconstruction. We performed a systematic review on the impact of additional prophylactic antithrombotic therapy on head and neck (H&N) free tissue transfer (on top and above the use of low molecular weight heparin to prevent deep vein thrombosis). We carried a PRISMA-guided literature review, following registration with PROSPERO. All studies analysing the possible impact of prophylactic anticoagulants on free flap surgery in the head and neck were eligible. The primary outcome was perioperative free flap complications (perioperative thrombosis, partial or total free flap failure, thrombo-embolic events, or re-exploration of anastomosis). Secondary outcomes included haematoma formation or bleeding complications requiring further intervention. We identified eight eligible studies out of 454. These included 3531 free flaps for H&N reconstruction. None of the assessed interventions demonstrated a statistically significant improvement in free flap outcomes. Accumulative analysis of all anti-coagulated groups demonstrated an increased relative risk of free flap complications [RR 1.54 (0.73-3.23)] compared to control albeit not statistically significant (p = 0.25). Pooled analysis from the included studies showed that the prophylactic use of therapeutic doses of anticoagulants significantly (p = 0.003) increased the risk of haematoma and bleeding requiring intervention [RR 2.98 (1.47-6.07)], without reducing the risk of free flap failure. Additional anticoagulation does not reduce the incidence of free flap thrombosis and failure. Unfractionated heparin (UFH) consistently increased the risk of free flap complications. The use of additional anticoagulation as 'prophylaxis' in the perioperative setting, increases the risk of haematoma and bleeding.

Perioperative Hypercoagulability in Free Flap Reconstructions Performed for Intracranial Tumors

OBJECTIVE(S)

Patients with intracranial tumors have a higher risk of thromboembolic events. This risk increases at the time of surgical intervention. We have noted an anecdotal increase in perioperative flap thrombosis in patients undergoing free tissue transfer for intracranial tumor resection. This study aims to formally evaluate this risk.

METHODS

A multi-institutional retrospective chart review was performed of patients who underwent free tissue transfer for scalp/cranial reconstruction. Perioperative thrombosis and free flap outcomes were evaluated.

RESULTS

The 209 patients who underwent 246 free tissue transfers were included in the study. The 28 free flap scalp reconstructions were associated with intracranial tumors, 19 were performed following composite cranial resections with associated dural resection/reconstruction, and 199 were performed in the absence of intracranial tumors (control group). There was a significantly higher incidence of perioperative flap thrombosis in the intracranial tumor group (11/28, 39%) when compared to controls (38/199, 19%) (p = 0.0287). This was not seen when scalp tumors extended to the dura alone (4/19, 21%, p = 0.83). Therapeutic anticoagulation used for perioperative thrombosis (defined as intraoperative or in the immediate postoperative phase up to 5 days) was associated with a lower risk of flap failure, although this was not statistically significant (p = 0.148). Flap survival rates were equivalent between flaps performed for intracranial pathology (93.3%) and controls (95%).

CONCLUSION

There is an increase in perioperative flap thrombosis in patients with intracranial tumors undergoing free tissue scalp reconstruction. Anticoagulation appears to mitigate this risk.

LEVEL OF EVIDENCE

This recommendation is based on level 3 evidence (retrospective case-control studies, systematic review of retrospective studies, and case reports) Laryngoscope, 2022.

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.

Intraoperative Heparin Bolus and Postoperative Anticoagulation with Low Molecular Weight Heparin Increase Reliability of Microsurgical Free Flaps for Upper Extremity Reconstruction

BACKGROUND

 Microsurgery is an indispensable tool of upper extremity reconstruction addressing defect coverage and the restoration of function. Perioperative anticoagulation and antiplatelet therapy are controversially discussed with impact on microsurgical outcome, but without clear evidence. This study aims to evaluate the impact of perioperative anticoagulation and antiplatelet therapy in microsurgical upper extremity reconstruction.

METHODS

 All eligible patients treated with microsurgical upper extremity reconstruction between January 2000 and July 2014 were included in a comparative analysis to define a superior anticoagulation and antiplatelet regime in a retrospective study. Endpoints were all major complications (e.g., total flap loss, arterial and venous thrombosis) as well as minor complication.

RESULTS

 A total of 183 eligible free flaps to the upper extremity were transferred in 169 patients. Altogether, 11 arterial (6.0%) and 9 venous (4.9%) thromboses, 11 total flap losses (6.0%), and 16 cases with hematoma (8.7%) were detected. In the subgroup analysis, patients who did not receive any heparin intraoperatively (n = 21; 11.5%) had a higher rate of major complications (p = 0.001), with total flap loss being the most frequent event (p = 0.004). A trend was shown for intraoperative bolus administration of 501 to 1,000 units unfractionated heparin (UFH) intravenously to have the lowest rate of major complications (p = 0.058). Intraoperative administration of acetylsalicylic acid (n = 13; 8.1%) did not have any influence on the rate of major complications. Postoperative anticoagulation with continuous UFH intravenously (n = 68; 37.2%) resulted in more frequent complications (p = 0.012), for example, an increased rate of total flap loss (p = 0.02) and arterial thrombosis (p = 0.02).

CONCLUSION

 The results of the present study favor administration of 501 to 1,000 units UFH intravenously as an intraoperative bolus (e.g., 750 units UFH intravenously). Postoperative low molecular weight heparin subcutaneous application in a prophylactic dose given once or twice a day was associated with less complications compared with continuous infusion of UFH, although continuously applied UFH may reflect an increased risk profile.

Should Antiplatelet Therapy Be Withheld Perioperatively? The First Study Examining Outcomes in Patients Receiving Dual Antiplatelet Therapy in the Lower Extremity Free Flap Population

BACKGROUND

Antiplatelet agents are typically withheld perioperatively because of bleeding concerns. Dual antiplatelet therapy, such as aspirin and clopidogrel, has significant morbidity and mortality benefits in patients with ischemic heart disease or peripheral vascular disease. This study aims to evaluate the impact of perioperative dual antiplatelet therapy in the lower extremity free tissue transfer population.

METHODS

Lower extremity free tissue transfers performed by the senior author (K.K.E.) from 2011 to 2019 were retrospectively reviewed. Demographics, comorbidities, perioperative dual antiplatelet therapy, and free tissue transfer characteristics were recorded. Outcomes of interest included flap success, hematoma formation, blood transfusion requirements, and cardiac event occurrence.

RESULTS

One hundred ninety-five free tissue transfers were included. Median age at the time of free tissue transfer was 56.5 years. Median Charlson Comorbidity Index was 3. Thirty-four patients were on clopidogrel, which was either withheld (n = 20) or continued (n = 14) on the day of free tissue transfer. Incidence of blood transfusion was significantly higher in both the withheld and continued versus nonclopidogrel groups. Flap success was statistically equivalent between groups (withheld, 90.0 percent; continued, 92.9 percent; nonclopidogrel, 95.0 percent; p = 0.346). Cardiac events occurred most often in the continued group (21.4 percent) compared to the withheld (5.0 percent) and nonclopidogrel (0.6 percent) groups. On multivariate analysis, holding clopidogrel remained significant for increased odds of postoperative transfusion. The clopidogrel group was no longer significant for intraoperative transfusion.

CONCLUSIONS

Despite increases in volume of blood products transfused, free tissue transfer can be performed safely with perioperative dual antiplatelet therapy. Withholding dual antiplatelet therapy on the day of free tissue transfer was not associated with decreased intraoperative transfusion; thus, dual antiplatelet therapy can safely be continued throughout the operative course to minimize cardiovascular risk.

CLINICAL QUESTION/LEVEL OF EVIDENCE

Therapeutic, III.

Multimodal Analgesia in Head and Neck Free Flap Reconstruction: A Systematic Review

OBJECTIVE

Postoperative pain after head and neck cancer surgery is commonly treated with opioids, which are associated with considerable side effects. The objective of this study is to analyze the safety and efficacy of using multimodal analgesia (MMA) for patients undergoing head and neck cancer surgery with free flap reconstruction.

DATA SOURCES

A systematic search was conducted in PubMed, Cochrane, Embase, Scopus, and clinicaltrials.gov.

REVIEW METHODS

All studies comparing patients receiving MMA (gabapentin, corticosteroids, local anesthetic, acetaminophen, nonsteroidal anti-inflammatory drugs [NSAIDs]) vs patients receiving opioids for head and neck cancer surgery with free flap reconstruction were screened. The primary outcome was postoperative opioid usage. Secondary outcomes included length of stay, subjective pain scores, surgical/medical complications, adverse effects, and 30-day outcomes.

RESULTS

A total of 10 studies representing 1253 patients (MMA, n = 594; non-MMA, n = 659) met inclusion criteria. Gabapentinoids were the most commonly used intervention (72.9%) followed by NSAIDs (44.6%), acetaminophen (44.3%), corticosteroids (25.1%), ketamine (7.2%), and nerve block (3.4%). Eight studies reported a significant decrease in postoperative opioid usage in the MMA groups. Subjective pain had wider variation, with most studies citing significant pain improvement. There were no differences in surgical outcomes, medical complications, adverse effects, or 30-day mortality and readmission rates.

CONCLUSION

With the rise of the opioid epidemic, MMA may play an important role in the treatment of postoperative pain after head and neck cancer surgery. A growing body of literature demonstrates a variety of effective perioperative regimens.

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.

The Influence of Topically Administered Heparin on Peripheral Microcirculation of the Skin: A Double-Blind, Randomized, Controlled Preliminary Study on 50 Healthy Subjects

BACKGROUND

 Venous thrombosis is the most common cause of flap failure in the first days after surgery. Although heparin is one of the most important antithrombotic substances and is implemented in the therapy of various diseases, there are only a few studies addressing its topical administration in the field of flap surgery. Especially, very little is known about the effects of topical heparin and its impact on microcirculation. In this study we evaluated to what extent topically administered heparin influences skin microcirculation (capillary venous oxygen saturation SO2, blood filling of microvessels, blood flow, and velocity) in healthy subjects.

METHODS

 Skin perfusion parameters on the forearm were measured with the O2C device in a double-blinded, controlled, and randomized study with 50 healthy subjects after administration of heparin ointment in three different concentrations and a control ointment (dexpanthenol).

RESULTS

 Topically administrated heparin slightly increased SO2 (max. 187 ± 285 SD or standard deviation % vs. 145 ± 129 SD %), flow (max. 264 ± 427 SD % vs. 151.74 ± 111 SD %), and velocity (max. 153 ± 149 SD % vs. 122 ± 56 SD %) after an incubation time of 60 minutes in comparison to control. No statistically significant difference could be detected regarding heparin concentration.

CONCLUSION

 As a first important step in possible future implementing of heparin as a topical administration in flap surgery, our data-although not statistically significant-indicate that heparin can improve microcirculation (SO2, flow) in healthy subjects. Nevertheless, further research in subjects with impaired microcirculation is necessary.

The effect of ticagrelor on microarterial thrombosis in an experimental model

Thromboses that form in the pedicle after free flap and/or replantation may result in the loss of the flap and/or limb. Ticagrelor is an adenosine diphosphate (ADP) receptor antagonist antithrombotic that can inhibit ADP-dependent platelet activation and aggregation. It is clinically used in acute coronary syndrome and unstable angina. However, its effect on microarterial anastomoses has not been investigated in the literature. An experimental thrombosis model was developed in both femoral arteries of a total of 40 rats. Twenty rats were randomly selected as the drug-free control group, and 20 rats were randomly selected as the ticagrelor group. The rats in the ticagrelor group were administered a 20 mg/kg loading dose orally by gavage 24 h before the experiment, and a maintenance dose of 2x10 mg/kg ticagrelor for 14 days after surgery. After the experiment, the femoral artery was evaluated for macroscopic and microscopic thrombosis, inflammation, edema, and endothelialization. Macroscopically and microscopically, thrombosis was observed at rates of 73.3% and 33.3% in the control group and the ticagrelor group, respectively. Inflammation in the vessel wall was found as 56.7% in the control group and 16.7% in the ticagrelor group. Edema in the vessel wall was found in 63.3% of the control group and 20% of the ticagrelor group. A statistical difference was found between the two groups in terms of thrombosis, inflammation, and edema. Both groups had similar characteristics in terms of endothelialization. Ticagrelor has a reducing effect on thrombosis in the microarterial tuck model.

Thromboelastometry for Assessing Risks of Free Flap Thrombosis in Patients Undergoing Microvascular Surgery

Introduction: Coagulation assessment is often missing in microvascular surgery. We aimed at evaluating the predictive value of thromboelastometry for free flap thrombosis in microvascular surgery patients. Materials and Methods: We enrolled 103 adult patients with traumatic injuries scheduled for microvascular free flap surgery into a prospective observational study. Thirty-six patients with recent trauma underwent surgery within 30 days (ES group), and were compared with 67 trauma patients who underwent surgery later than 30 days (late surgery, LS group) after the injury. Rotational thromboelastometry (RTE) was performed before surgery. Functional fibrinogen to platelet ratio (FPR) ≥ 42 was selected as the main hypercoagulability index. Free flap thrombosis was set as primary outcome. Thrombotic risk factors and duration of surgery related to free flap thrombosis were secondary outcomes. Statistical significance p < 0.05; not significant NS. Results: Six patients (16.7%) in the ES group and 10 (14.9%) in the LS group had free flap thrombosis (NS). In the entire cohort, free flap thrombosis rate increased in the presence of thrombogenic comorbidities (OR 4.059, CI 1.33-12.37; p = 0.014) and prolonged surgery times (OR 1.007, CI 1 - 1.012; p = 0.05). Although hypercoagulability occurred more frequently in the ES group (44.4%) than in the LS group (11.9%; p < 0.001), it was not associated with higher free flap thrombosis rate. In ES group patients with surgery times > 240 min, the risk of free flap thrombosis increased (OR 3.5, CI 1.16-10.6; p = 0.026) with 93.3% sensitivity and 86.7% specificity (AUC 0.85; p = 0.007). In contrast, in LS patients hypercoagulability increased the odds of free flap thrombosis (OR 8.83, CI 1.74-44.76; p = 0.009). Moreover, a positive correlation was found between FPR ≥ 42 and free flap thrombosis rate (r = 0.362; p = 0.003). In the LS group, the presence of thrombogenic comorbidities correlated with free flap thrombosis rate (OR 7, CI 1.591-30.8; p = 0.01). Conclusions: In LS patients with thrombogenic comorbidities, thromboelastometry supports the detection of hypercoagulability and predicts free flap thrombosis risk. In ES patients, postoperative hypercoagulability did not predict free flap thrombosis. Prolonged surgery time should be considered as a risk factor.

Tourniquet use and factors associated with hematoma formation in free tissue transfer

PURPOSE

Our objective was to understand which variables are associated with hematoma formation at both the donor and recipient sites in head and neck free tissue transfer and if hematoma rates are affected by tourniquet use.

METHODS

Patients were identified who underwent free tissue transfer at three institutions, specifically either a radial forearm free flap (RFFF) or a fibula free flap (FFF), between 2007 and 2017. Variables including use of tourniquet, anticoagulation, treatment factors, demographics, and post-operative factors were examined to see if they influenced hematoma formation at either the free tissue donor or recipient site.

RESULTS

1410 patients at three institutions were included in the analysis. There were 692 (49.1%) RFFF and 718 (50.9%) FFF. Tourniquets were used in 764 (54.1%) cases. There were 121 (8.5%) hematomas. Heparin drips (p < .001) and DVT prophylaxis (p = .03) were significantly associated with hematoma formation (OR 95% CI 12.23 (4.98-30.07), 3.46 (1.15-10.44) respectively) on multivariable analysis.

CONCLUSIONS

Heparin Drips and DVT prophylaxis significantly increased hematoma rates in free flap patients while tourniquets did not affect rates of hematoma.

Anesthesia and Enhanced Recovery After Head and Neck Surgery

Enhanced recovery protocols have been developed from gastrointestinal, colorectal, and thoracic surgery populations. The basic tenets of head and neck enhanced recovery are: a multidisciplinary team working around the patient, preoperative carbohydrate loading, multimodal analgesia, early mobilization and oral feeding, and frequent reassessment and auditing of protocols to improve patient outcomes. The implementation of enhanced recovery protocols across surgical populations appear to decrease length of stay, reduce cost, and improve patient satisfaction without sacrificing patient quality of care or changing readmission rates. This article examines evidence-based enhanced recovery interventions and tailors them to a major head and neck surgery population.

Postoperative Hematoma in Microvascular Reconstruction of the Head and Neck

BACKGROUND

Free tissue transfer has become a safe and reliable means for repairing soft tissue and bony defects of the head and neck region. Although the success rate is high, the incidence of postoperative complications is common. One significant complication is postoperative hematoma formation. However, few published studies have addressed its incidence, etiology, or outcome. We performed a retrospective analysis to investigate this issue.

METHODS

A retrospective review was conducted of 293 consecutive microvascular free tissue transfers in the head and neck region in a single institute from January 2013 to December 2015. Patients with postoperative hematoma were identified, and demographic data, perioperative conditions, medications, and outcomes were evaluated by chart review.

RESULTS

A total of 34 patients (11.8%) had postoperative hematoma. Compared with the patients without hematoma, this group had a longer hospital stay (P = 0.06) and required more secondary procedures (P = 0.001). The use of nonsteroidal anti-inflammatory drugs (NSAIDs; P < 0.001) was associated with a higher incidence of hematoma formation. Among the 34 patients with hematoma, 16 (47.1%) had flap compromise and underwent emergent reexploration. The salvage rate was higher than that in the nonhematoma group (87.5% vs 59.3%, P = 0.086).

CONCLUSIONS

Postoperative hematoma after head and neck microvascular reconstruction is not a rare complication and may lead to poor outcome and more complications. The avoidance of NSAIDs preoperatively may prevent hematoma formation. Surgeons should be alert to this situation, and immediate return to the operative room for hematoma evacuation is necessary. Early intervention may contribute to a high salvage rate.

Are antithrombotic agents necessary for head and neck microvascular surgery?

The aim of this prospective study was to determine the effect of antithrombotic agents in preventing thrombosis after head and neck reconstructive surgery. A randomized clinical trial of referred patients undergoing free flap surgery between February 2015 and July 2017 was conducted. Four hundred and fifty-four patients were randomly assigned to group A (n=153), administered aspirin and low molecular weight dextran; group B (n=150), administered low molecular weight heparin; and group C (n=151), not administered any antithrombotic agent. Patient demographic characteristics, donor site, thrombosis, haematoma, and flap failure were recorded. Coagulation values including platelet count, prothrombin time, and activated partial thromboplastin time were measured during the perioperative period. Repeated-measures ANOVA and the χ² test were used for data comparisons. No significant inter-group differences were observed for postoperative microvascular thrombosis (P=0.536) or flap failure (P=0.615) among the three groups. There were more postoperative haematoma revisions in group B than in groups A and C (P=0.032). It is concluded that postoperative antithrombotic agents neither provide a significant improvement in the free flap success rate nor decrease the risk of thrombosis and may increase the risk of haematoma.

Current practices in microvascular reconstruction in otolaryngology-head and neck surgery

OBJECTIVES/HYPOTHESIS

Despite major advances in the field of head and neck microvascular free tissue transfer (MFTT) over the past several decades, there are no standardized perioperative regimens for the care of patients undergoing free flap reconstructive surgery, and continued variation in practice exists. This study aimed to report current trends in the field of MFTT performed by otolaryngologists, including surgeon training, institutional operative practices, and perioperative management.

STUDY DESIGN

Cross-sectional survey.

METHODS

A survey of Accreditation Council for Graduate Medical Education-accredited residency programs and American Head and Neck Society fellowship sites was conducted.

RESULTS

Seventy-one (62.8%) programs responded, with 67 (94.4%) routinely performing MFTT and 23 (32.4%) having a dedicated microvascular fellowship program. Of institutions performing MFTT, 66 (98.5%) reported the use of a two-surgeon team, most commonly both otolaryngologists (76.3%). Institutional MFTT volumes and donor site frequency are reported. Postoperative care includes routine admission to the intensive care unit (75.2%), step-down unit (15.0%), or general care floor (8.1%). Postoperative flap monitoring practices, including modalities, personnel, and timing/frequency show institutional variation. Despite differences in postoperative monitoring regimen and management (sedation, anticoagulation, antibiotic use), surgeon-reported measures of flap success rate (95.7%, standard deviation [SD] 4.7%) and complication rate (6.8%, SD 2.4%) show little difference across institutions.

CONCLUSIONS

Many elements of MFTT perioperative care show continued variation at an institutional level. There is a notable shift toward the two-team approach within otolaryngology. Self-reported flap complication and success rates showed no significant differences based on perioperative care and monitoring regimen. Further study of perioperative practices should focus on standardization of care to improve overall outcomes in this complex patient population.

LEVEL OF EVIDENCE

NA Laryngoscope, 129:138-145, 2019.

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.

Thromboprophylaxis in Head and Neck Microvascular Reconstruction

Head and neck patients undergoing microvascular reconstruction are at high risk for thromboembolism. While the prevention of thromboembolism has become an essential aspect of care, within the field of microsurgery, concern for anastomotic complications have hindered the creation of an accepted regimen. The aim of this review was to evaluate the risks and benefits of prophylactic agents for thromboprophylaxis. A literature search was conducted in MEDLINE, Cochrane Library, and PubMed/NCBI databases. Articles discussing thromboprophylaxis in otolaryngology, head and neck surgery, or microvascular reconstruction were considered in the review from the past 30 years. The majority of patients undergoing microvascular surgery have multiple risk factors for thrombus formation. Several consensus guidelines exist for the prophylaxis in patients who are critically ill, undergoing surgery, or with malignancy. Significant evidence supports the routine use of mechanical means, such as early mobilization and pneumatic compression along with subcutaneous heparin. Low-molecular-weight heparin is also frequently utilized, although results are largely divided. Data on aspirin remain equivocal. Studies on microvascular failure and flap loss have demonstrated little to no association with chemoprophylaxis. The evidence for postoperative thromboprophylaxis regimens in patients undergoing head and neck free tissue transfer is variable. Multiple studies have supported the use of unfractionated heparin or low-molecular-weight heparin. There appears to be an expert consensus for the combined use of mechanical prophylactic methods and chemical prophylaxis. Prospective randomized trials are required to validate the most effective combination of chemoprophylaxis agents.

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.

Does Low-Dose Heparin Have a Significant Role in Free Flap Surgery?

Background

It is controversial issue that heparin decreases thrombosis for microsurgical anastomosis, and its effective role is under discussion. This study is for proving whether low-dose heparin is preventing thrombosis in free flap reconstruction.

Methods

Through chart reviews of 134 patients, using low-dose heparin for free tissue transfer from 2011 to 2016, retrospective analysis was performed. 33 patients received low-dose heparin therapy after surgery. And 101 patients received no-heparin therapy. Complications included flap necrosis, hematoma formation, dehiscence and infection.

Results

In no-heparin therapy group, comparing the flap necrosis revealed 16 cases (15.84%). And, flap necrosis was 6 cases (18.18%) in low-dose heparin therapy group. The statistical analysis of flap necrosis rate showed no significant difference (p=0.75). The results showed that there was no significant difference of flap necrosis rate between two groups.

Conclusion

In this study, patients in the low-dose heparin group had no significantly lower rates of flap failure compared with no-heparin group. This suggests that low-dose heparin may not prevent thrombosis and subsequent flap failure to a significant extent.

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.

Spontaneous Iliopsoas Hematoma following Microvascular Free Tissue Transfer

Spontaneous hematoma within the iliopsoas muscle (SIH) is a rare complication most commonly seen in coagulopathic patients. Often, patients undergoing microvascular free tissue transfer are anticoagulated for anastomotic patency. Here we describe two cases of postoperative SIH following contralateral anterolateral thigh (ALT) free tissue transfer for reconstruction of oncologic head and neck defects. Both patients described hip pain after mobilization and had a corresponding acute blood loss anemia. Diagnosis of SIH was confirmed by CT and both patients were managed conservatively. Given that anticoagulation is a common practice following head and neck free tissue transfer, surgeons should be aware of this potential complication.

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

BACKGROUND

Free radial forearm flap (FRFF) reconstruction is a valuable technique in head and neck surgery, which allows closure of large defects while striving to maintain functionality. Anticoagulative drugs are often administered to improve flap survival, although evidence regarding effectiveness is lacking.

OBJECTIVE OF REVIEW

To investigate the effectiveness of postoperative anticoagulants to improve survival of the FRFF in head and neck reconstruction.

TYPE OF REVIEW

Systematic review and multicentre, individual patient data meta-analysis.

SEARCH STRATEGY

MEDLINE, EMBASE, Web of Science and CINAHL were searched for synonyms of 'anticoagulants' and 'free flap reconstruction'.

EVALUATION METHOD

Studies were critically appraised for directness of evidence and risk of bias. Authors of the highest quality publications were invited to submit their original data for meta-analysis.

RESULTS

Five studies were of adequate quality, and data from four studies (80%) were available for meta-analysis, describing 759 FRFF procedures. Anticoagulants used were as follows: aspirin (12%), low molecular weight dextran (18.3%), unfractioned heparin (28.1%), low molecular weight heparin (49%) and prostaglandin-E1 (2.1%). Thirty-one per cent did not receive anticoagulants. Flap failure occurred in 40 of 759 patients (5.3%) On univariate analysis, use of unfractioned heparin was associated with a higher rate of flap failure. However, these regimens were often administered to patients who had revision surgery of the anastomosis. In multivariate logistic regression analysis, anticoagulant use was not associated with improved flap survival or flap-related complications.

CONCLUSIONS

The studied anticoagulative drugs did not improve FRFF survival or lower the rate of flap-related complications. In addition, some anticoagulants may cause systemic complications.

The Effect of Activated Protein C on Attenuation of Ischemia-Reperfusion Injury in a Rat Muscle Flap Model

Ischemia-reperfusion injury is often the final and irreversible factor causing flap failure in microsurgery. The salvage of a microsurgical flap with an ischemia-reperfusion injury contributes to the success of microsurgical flap transfers. Activated protein C (APC), a serine protease with anticoagulant and anti-inflammatory activities, has been shown to improve ischemic flap survival. To date, APC has yet to be applied to models of free flap with ischemia-reperfusion injury. In this study, we aimed to investigate the effect of APC on gracilis flap ischemia-reperfusion injury induced by gracilis vessels clamping and reopening. Sixty male Sprague-Dawley rats were randomly divided into 2 groups. After 4 hours of clamping for ischemia, flaps were reperfused and recombinant human APC (25 μg/kg) or saline was injected in the flaps through pedicles. At 0, 1, 4, 18, and 24 hours after injection (n = 6 for each time point), the tissue samples were harvested. The muscle viability at 24 hours in saline group was 54.8% (15.1%), whereas the APC-treated group was 90.0% (4.3%) (P < 0.05). The induced nitric oxide synthase (iNOS) mRNA expression increased with the time after reperfusion, which were 0.93 (0.25) to 2.09 (0.22) in saline group, and 0.197 (0.15) to 0.711 (0.15) in the APC-treated group. iNOS mRNA expression in the APC-treated group was significantly higher than the saline group at 1, 18, and 24 hours (P < 0.05). Numerous inflammatory cells were observed infiltrating and invading the muscle fibers in the saline group more than the APC-treated group. Increased number of polymorphonuclear cells was also noted in the saline group compared with the APC-treated group (P < 0.05). In conclusion, APC treatment can significantly attenuate ischemia-reperfusion injury and increase the survival of the free flap through down-regulating iNOS mRNA expression and reducing the inflammatory cells. Further research is still needed to be done on various mechanisms in which APC is protective to prevent tissue damage.

Microsurgery and the Hypercoagulable State: A Hematologist's Perspective

Hypercoagulability can pose a significant problem in microsurgical reconstruction. Here, the authors provide a comprehensive review of macrovascular and microvascular clotting phenomena from the unique viewpoint of two microsurgeons and a hematologist. The authors review the literature surrounding prevention of microvascular clots and provide an extensive discussion of hereditary thrombophilia. The authors also make explicit recommendations regarding the utility of thrombophilia testing and preoperative and perioperative management strategies for patients with hypercoagulability.

Free flap reconstruction experience and outcomes at a low-volume institution over 20 years

OBJECTIVE

Assess the efficacy of free flap reconstruction performed at a low-volume program and evaluate how volume and outcomes have changed over 20 years.

STUDY DESIGN

Case series with chart review.

SETTING

Tertiary academic medical center.

SUBJECTS AND METHODS

A retrospective chart review was performed at a tertiary care academic program on all free tissue flaps from the primary reconstructive surgeon over 20 years (1993-2013). In total, 136 procedures were obtained from operative notes, billing codes, and chart databases. Outcome variables included procedure success and complications. Patients stayed in general intensive care unit and hospital floor units.

RESULTS

Flap success was 92.6% of all cases. In the past 13 years, 70 flaps were performed with 3 failures (96% success rate). Take-back rate was 16% of total cases with a flap recovery rate of 60%. Postoperative failure occurred after 72 hours in 60% of cases. Nearly 60% of patients experienced a complication of any type or severity. Twenty percent had a flap complication while maintaining viability, with half of these being partial dehiscence. Systemic complications affected 20% of all cases. The average hospital stay for noncomplicated patients was 13 days. There was 1 postoperative mortality. Fibula and radial forearm were the most common flaps at 44% and 26%, respectively.

CONCLUSION

Free flap reconstruction of the head and neck can be performed by appropriately skilled surgeons with acceptable outcomes in low-volume settings. Success rate appears to increase as clinical experience is gained.

Emerging paradigms in perioperative management for microsurgical free tissue transfer: review of the literature and evidence-based guidelines

BACKGROUND

Microsurgical free tissue transfer has become an increasingly valuable technique in reconstructive surgery. However, there is a paucity of evidence-based guidelines to direct management. A systematic review was performed to define strategies to optimize perioperative management.

METHODS

A systematic review of the literature was performed using key search terms. Strategies to guide patient management were identified, classified according to level of evidence, and used to devise recommendations in seven categories: patient temperature, anesthesia, fluid administration/blood transfusion, vasodilators, vasopressors, and anticoagulation.

RESULTS

A total of 106 articles were selected and reviewed. High-level evidence was identified to guide practices in several key areas, including patient temperature, fluid management, vasopressor use, anticoagulation, and analgesic use.

CONCLUSIONS

Current practices remain exceedingly diverse. Key strategies to improve patient outcomes can be defined from the available literature. Key evidence-based guidelines included that normothermia should be maintained perioperatively to improve outcomes (level of evidence 2b), and volume replacement should be maintained between 3.5 and 6.0 ml/kg per hour (level of evidence 2b). Vasopressors do not harm outcomes and may improve flap flow (level of evidence 1b), with most evidence supporting the use of norepinephrine over other vasopressors (level of evidence 1b). Dextran should be avoided (level of evidence 1b), and pump systems for local anesthetic infusion are beneficial following free flap breast reconstruction (level of evidence 1b). Further prospective studies will improve the quality of available evidence.

Microsurgical reconstruction of the head and neck--current concepts of maxillofacial surgery in Europe

INTRODUCTION

Microvascular surgery following tumour resection has become an important field of oral maxillofacial surgery (OMFS). This paper aims to evaluate current microsurgical practice in Europe.

METHODS

The questionnaire of the DOESAK collaborative group for Microsurgical Reconstruction was translated into English, transformed into an online based survey and distributed to 200 OMFS units with the aid of the European Association for Cranio-Maxillo-Facial Surgery (EACMFS).

RESULTS

65 complete and 72 incomplete questionnaires were returned. Hospitals from the United Kingdom, France, Italy, the Netherlands, Spain, Belgium, Greece, Slovenia and Lithuania participated. 71% of contributing centres were university hospitals, 87% out of these perform microvascular tumour surgery at least on a two-weekly base. Overall complication rate was at around five percent. Most frequently used transplants were the radial forearm flap and the fibular flap. The perioperative management varied widely. Success factors for flap survival, however, were uniformly rated, with the surgical skill being the most important factor, followed by the quality of postoperative management. Medication seems to play a less important role.

CONCLUSION

Within Europe microvascular surgery is a common and safe procedure for maxillofacial reconstructive surgery in the field of OMFS. While there is a major accordance for the surgical procedure itself and the most frequently used flaps, perioperative management shows a wide variety of protocols with low presumed impact on surgical outcome.

Effect of heparin on prevention of flap loss in microsurgical free flap transfer: a meta-analysis

The effectiveness of heparin for thromboprophylaxis during microvascular free flap transfer is uncertain. The purpose of this meta-analysis was to determine the effect of heparin on the prevention of flap loss in microsurgical free flap transfer.A search of PubMed, Cochrane databases, and Google Scholar using combinations of the search terms heparin, free flap, flap loss, free tissue transfer was conducted on March 15, 2013. Inclusion criteria were: 1) Prospective randomized trials. 2) Retrospective, non-randomized studies. 3) Patients received free tissue transfer. Flap loss rate was used to evaluate treatment efficacy. Odds ratios (ORs) with 95% confidence intervals (CI) were calculated and compared between therapies. Four studies meet the criteria for analysis and were included. Two studiescompared aspirin and heparin, and the ORs of the 2 studies were 1.688 and 2.087. The combined OR of 2.003 (95% CI 0.976–4.109, p = 0.058) did not indicate any significant difference between heparin and aspirin therapies. Two studiescompared high and low doses of dalteparin/heparin therapies, and the ORs of the 2 studies were 4.691 and 11.00. The combined OR of 7.810 (95% CI 1.859–32.808, p = 0.005) revealed a significant difference indicating that high dose dalteparin or heparin therapy is associated with a greater flap loss rate than low dose therapy. Heparin and aspirin prophylaxis are associated with similar flap loss rates after free flap transfer, and high dose dalteparin or heparin therapy is associated with a greater flap loss rate than low dose therapy.