Dextran-Related Complications in Head and Neck Microsurgery: Do the Benefits Outweigh the Risks? A Prospective Randomized Analysis

Novel Challenges and Opportunities for Anesthesia and Perioperative Care in Microvascular Flap Surgery: A Narrative Review

Complex microvascular techniques and in-depth knowledge of blood rheology and microanastomosis function are required for success in microvascular flap surgery. Substantial progress has been achieved in preventing complications, but the rate of flap loss is still significant and can have significant adverse effects on the patient. Flap thrombosis, flap hematoma, and flap loss are the most frequent and severe major surgical complications. Advances in understanding the pathophysiology of different flap complications, the use of preoperative risk assessment and new treatment concepts could improve the perioperative care of microvascular flap surgery patients. Our aim was to outline novel avenues for best practice and provide an outlook for further research of anesthesia and perioperative care concepts in microvascular flap surgery.

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.

Successful microvascular surgery in patients with thrombophilia in head and neck surgery: a case series

BACKGROUND

In this case series, a perioperative anticoagulation protocol for microvascular head and neck surgery in patients with thrombophilia is presented. Microvascular free-flap surgery is a standard procedure in head and neck surgery with high success rates. Nevertheless, flap loss-which is most often caused by thrombosis-can occur and has far-reaching consequences, such as functional impairment, prolonged hospitalization, and increased costs. The risk of flap loss owing to thrombosis is significantly increased in patients with thrombophilia. Therefore, perioperative anticoagulation is mandatory. To date, no perioperative anticoagulation protocol exists for these high-risk patients.

CASE PRESENTATION

We present three exemplary male Caucasian patients aged 53-57 years with free flap loss owing to an underlying, hidden thrombophilia.

CONCLUSION

We present a modified anticoagulation protocol for microvascular surgery in these high-risk patients, enabling successful microsurgical reconstruction.

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.

Intraoperative Infusion of Dextran Confers No Additional Benefit after Carotid Endarterectomy but Is Associated with Increased Perioperative Major Adverse Cardiac Events

BACKGROUND

Intraoperative dextran infusion has been associated with reduction of an embolic risk in patients undergoing carotid endarterectomy (CEA). Nonetheless, dextran has been associated with adverse reactions, including anaphylaxis, hemorrhage, cardiac, and renal complications. Herein, we aimed to compare the perioperative outcomes of CEA stratified by the use of intraoperative dextran infusion using a large multiinstitutional dataset.

METHODS

Patients undergoing CEA between 2008 and 2022 from the Vascular Quality Initiative database were reviewed. Patients were categorized by use of intraoperative dextran infusion, and demographics, procedural data, and in-hospital outcomes were compared. Logistic regression analysis was utilized to adjust for differences in patients while assessing the association between postoperative outcomes and intraoperative infusion of dextran.

RESULTS

Of 140,893 patients undergoing CEA, 9,935 (7.1%) patients had intraoperative dextran infusion. Patients with intraoperative dextran infusion were older with lower rates of symptomatic stenosis (24.7% vs. 29.3%; P < 0.001) and preoperative use of antiplatelets, anticoagulants and statins. Additionally, they were more likely to have severe carotid stenosis (>80%; 49% vs. 45%; P < 0.001) and undergo CEA under general anesthesia (96.4% vs. 92.3%; P < 0.001), with a more frequent use of shunt (64.4% vs. 49.5%; P < 0.001). After adjustment, multivariable analysis showed that intraoperative dextran infusion was associated with higher odds of in-hospital major adverse cardiac events (MACE), including myocardial infarction [MI] (odds ratio [OR], 1.76, 95% confidence interval [CI]: 1.34-2.3, P < 0.001), congestive heart failure [CHF] (OR, 2.15, 95% CI: 1.67-2.77, P = 0.001), and hemodynamic instability requiring vasoactive agents (OR, 1.08, 95% CI: 1.03-1.13, P = 0.001). However, it was not associated with decreased odds of stroke (OR, 0.92, 95% CI: 0.74-1.16, P = 0.489) or death (OR, 0.88, 95% CI: 0.58-1.35, P = 0.554). These trends persisted even when stratified by symptomatic status and degree of stenosis.

CONCLUSIONS

Intraoperative infusion of dextran was associated with increased odds of MACE, including MI, CHF, and persistent hemodynamic instability, without decreasing the risk of stroke perioperatively. Given these results, judicious use of dextran in patients undergoing CEA is recommended. Furthermore, careful perioperative cardiac management is warranted in select patients receiving intraoperative dextran during CEA.

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.

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.

"Systematic Review and Guidelines for Perioperative Management of Pediatric Patients Undergoing Major Plastic Surgery Procedures, With a Focus on Free Tissue Transfer."

BACKGROUND

Microsurgical free tissue transfer has been successfully implemented for various reconstructive applications in children. The goal of this study was to identify the best available evidence on perioperative management of pediatric patients undergoing free tissue transfer, and use it to develop evidence-based care guidelines.

METHODS

A systematic review was conducted in Pubmed, Embase, Scopus, and Cochrane Library databases. Since a preliminary search of the pediatric microsurgical literature yielded scant data with low level of evidence (LOE), pediatric anesthesia guidelines for healthy children undergoing major surgeries were also included. Exclusion criteria included: vague descriptions of perioperative care, case reports, and studies of syndromic or chronically ill children.

RESULTS

204 articles were identified, and 53 met inclusion criteria. Management approaches specific to the pediatric population were used to formulate recommendations. High quality data was found for anesthesia, analgesia, fluid administration / blood transfusion, and anticoagulation (LOE 1). Lower quality evidence was identified for patient temperature (LOE 3) and vasodilator use (LOE 4). Key recommendations include: administering sevoflurane for general anesthesia, implementing a multimodal analgesia strategy, limiting preoperative fasting, restricting blood transfusions until hemoglobin < 7 g/dl unless patient is symptomatic, and reserving chemical venous thromboembolism prophylaxis for high risk patients.

CONCLUSIONS

Pediatric-specific guidelines are important as they acknowledge physiologic differences in children, which may be overlooked when extrapolating from adult studies. These evidence-based recommendations are a key first step toward standardization of perioperative care of pediatric patients undergoing plastic surgical procedures, including free tissue transfer, to improve outcomes and minimize complications.

Patient Management Strategies in Perioperative, Intraoperative, and Postoperative Period in Breast Reconstruction With DIEP-Flap: Clinical Recommendations

Background and Objective

Deep Inferior Epigastric Perforator (DIEP) flap is a tissue isolated from the skin and subcutaneous tissue of the lower abdomen or rectus muscle to foster breast reconstruction. There is limited information about DIEP-flap induced complications associated with breast reconstruction surgery.

Evidence

We conducted a systematic review of the published literature in the field of breast cancer reconstruction surgery. Information was gathered through internet resources such as PubMed, Medline, eMedicine, NLM, and ReleMed etc. The following key phrases were used for effective literature collection: “DIEP flap”, “Breast reconstruction”, “Patient management”, “Postoperative DIEP”, “Intraoperative anticoagulant therapy”, “Clinical recommendations”. A total of 106 research papers were retrieved pertaining to this systematic review.

Conclusion

A successful breast reconstruction with DIEP-flap without complications is the priority achievement for this surgical procedure. This study provides various evidence-based recommendations on patient management in the perioperative, intraoperative, and postoperative periods. The clinical recommendations provided in this review can benefit surgeons to execute breast reconstruction surgery with minimal postoperative complications. These recommendations are beneficial to improve clinical outcomes when performing surgery by minimizing complications in perioperative, intraoperative, and postoperative period.

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.

Free Flap Surgery Outcome Related to Antithrombotic Treatment Regime: An Analysis of 1000 Cases

Background:

Autologous free tissue transfer is today an integral part of reconstructive plastic surgery, but still lacks generally accepted guidelines regarding antithrombotic agents. We hypothesized that the overuse of antithrombotic agents could be a risk factor for free flap complications and therefore studied a treatment protocol adjustment.

Methods:

Consecutive free flaps between 2005 and 2020 at a single center were analyzed for complications in relation to the use of pre- and intraoperative treatment with three different antithrombotic agents. The use of preoperative low molecular weight heparin (LMWH), intraoperative heparin, and dextran were analyzed in relation to outcome variables, thromboembolic events, or reexploration for hematoma.

Results:

Nine hundred thirty-one patients underwent 1000 microvascular free flaps for breast (n = 487), head and neck (n = 365), and extremity (n = 148) reconstruction. Within the first postoperative week, 44 cases had a thromboembolic event and 58 cases underwent hematoma-related reexploration. In the multivariate analysis, thromboembolic events were associated with extremity reconstruction (P = 0.02) and smoking (P = 0.02). Hematoma-related reexploration was more common with triple antithrombotic therapy compared with all other treatment regimes (P < 0.05). The number of antithrombotic agents used perioperatively was linearly decreased, from three to none, over the elapsed time period (P < 0.001).

Conclusions:

Hematoma was the most common reason for reexploration and was further associated with the use of multiple antithrombotic agents. Cessation of triple treatment was associated with less hematomas and further reduction of antithrombotic agents did not result in any increase of thromboembolic events. Evidence-based guidelines are warranted for antithrombotic regimes in standard free flap surgery.

Free Flap Reconstruction and Its Management in Sickle Cell Trait: Lessons Learned from a Case

Oral cancers are amongst the most common cancers in the Indian subcontinent; in India alone, an estimated 1.2 lakh new patients were diagnosed with it. Reconstruction with free flaps slowly gained popularity over time to become the standard for care for treating large head and neck defects. Flap selection is a complex process; more specifically, the preoperative conditions of patients, the extent of the disease, and the resources available are critical considerations to consider when selecting the best reconstructive technique. It is very well established that certain parts of India, especially the tribal area of Central and southern India, have high prevalence of sickle cell trait (SCT) and sickle cell disease compared to the rest of the country. The sickle cell trait poses a potential increase in morbidity in the perioperative care due to surgical stress. Unfortunately, there are no published articles on the management of a free flap in a case of SCT. Here, in this article, we investigate the issues encountered during the perioperative care in a patient who undergone oral cavity composite resection with free fibula reconstruction. SCT screening must be undertaken mainly to identify, mitigate, and manage the adverse events in the perioperative period. The screening test is very inexpensive and has good sensitivity to detect the heterozygous and homozygous disease. We would recommend screening of all the patients hailing from high-risk endemic areas. The free flap in a case of sickle cell trait is not a contraindication, but a surgeon must understand the nuances in the management of complications in such case. Screening for sickle cell trait followed by perioperative blood transfusions, anticoagulation seems beneficial in a patient undergoing free flaps with sickle cell trait.

Postoperative Digit and Hand Replantation Protocols: A Review of the Literature

Successful replantation and revascularization of the hand and digit require a skilled team with urgent access to an operating room with microsurgical capabilities. Although careful indications and surgical techniques contribute to success, postoperative management also plays a vital role in the survival of a replanted digit. Previous research has assessed surgical efficiency and techniques to conduct these procedures, but few studies evaluate postoperative protocols to care for patients undergoing these procedures. Because of the lack of high-level evidence specific to replantation, many common postoperative practices related to monitoring, anticoagulation, and diet have been inferred from elective microsurgical procedures, despite notable differences in operating conditions. The highest level of evidence pertaining to digital replantation was found with the use of peripheral nerve blockade, leeching/bleeding, and nicotine use. This review provides an in-depth evaluation of the literature and insight into the rationale and level of evidence that support each postoperative intervention. It highlights institutional variability and a paucity of high-level evidence pertaining to this topic while identifying the areas of future research.

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.

Value of Intensive Care Unit-Based Postoperative Management for Microvascular Free Flap Reconstruction in Head and Neck Surgery

Importance: Although routine postoperative care for microvascular free flap reconstruction typically involves admission to the intensive care unit (ICU), few studies have investigated the effect of postoperative care setting on clinical outcomes and institution cost. Objectives: To determine the value of non-ICU-based postoperative management for free tissue transfer for head and neck surgery, in terms of clinical outcomes and cost-effectiveness. Design, Setting, and Participants: This is a retrospective cohort study of two groups of adults who underwent vascularized free tissue transfer from October 2013 to October 2017 at an academic tertiary care center and community-based hospital, respectively. Postoperative management differed such that the first group recovered in a protocol-driven non-ICU setting and the second group was cared for in a planned admission to the ICU. A single surgeon performed all tissue harvest and reconstruction at both centers. Main Outcomes and Measures: Descriptive statistics and cost analyses were performed to compare clinical outcomes and total surgical and downstream direct cost to the institution between the two patient groups. Categorical variables were compared using χ² test where appropriate. Results: Among a total of 338 patients who underwent microvascular free flap reconstruction for head and neck surgical defects, there was no significant difference in patient characteristics such as demographics, comorbidities, history of surgical resection, prior free flap, and locoradiation between the postoperative ICU cohort (n = 146) and protocol-driven non-ICU cohort (n = 192). There were 16 patients in the non-ICU group who spent >3 days in the ICU postoperatively secondary to patient comorbidities and patient care priorities. Still, the average ICU length of stay was 7 days (interquartile range [IQR] 6-9 days) for the planned ICU cohort versus 1 day (IQR 0-1) for the non-ICU group (p < 0.00001). There was no difference in operative variables such as donor site, case length, or total length of stay, and postoperative management in the ICU versus non-ICU setting resulted in no significant difference in terms of flap survival, reoperation, readmission, and postoperative complications. However, average cost of care was significantly higher for patients who received ICU-based care versus non-ICU postoperative care. Specifically, room and board were 239% more costly for the planned ICU care group than the non-ICU setting (p < 0.00001). Conclusions and Relevance: This study demonstrates that postoperative management after vascularized free tissue transfer in a non-ICU setting is equivalent to standard ICU-based management, in terms of clinical outcomes, while being less costly.

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.

Head and Neck Microsurgeon Practice Patterns and Perceptions Regarding Venous Thromboembolism Prophylaxis

Background Patients undergoing head and neck (H&N) microvascular reconstruction comprise a population at high risk for venous thromboembolism (VTE). Free flap and VTE thromboprophylaxis may coincide but tend to vary from surgeon to surgeon. This study identifies VTE prophylaxis patterns and perceptions among H&N microsurgeons in the United States.

Methods An online survey on VTE prophylaxis practice patterns and perceptions was emailed to 172 H&N microsurgeons in the United States using an anonymous link.

Results There were 74 respondents (43% response rate). These surgeons completed residencies in otolaryngology (59%), plastic surgery (31%), and oral maxillofacial surgery (7%). Most underwent fellowship training (95%) and have practiced at an academic center (97%) for at least 6 years (58%), performing an average of 42 ± 31 H&N free flap cases per year (range = 1–190). Most adhered to general VTE prophylaxis guidelines (69%) while 11% did not and 20% were unsure. Nearly all surgeons (99%) would provide prophylactic anticoagulation, mostly in the form of subcutaneous heparin (51%) or enoxaparin (44%); 64% additionally used aspirin, while 4% used aspirin alone. The majority of surgeons (68%) reported having postoperative VTE complications, with six surgeons (8%) reporting patient deaths due to pulmonary embolism. A third of the surgeons have encountered VTE prophylaxis-related adverse bleeding events, but most still believe that chemoprophylaxis is important for VTE prevention (92%). While 35% of surgeons were satisfied with their current practice, most would find it helpful to have official prophylactic anticoagulation guidelines specific to H&N free flap cases.

Conclusion The majority of microsurgeons experienced postoperative VTE complications after H&N free flap reconstruction despite the routine use of prophylactic anticoagulation. Though bleeding events are a concern, most surgeons believe chemoprophylaxis is important for VTE prevention and would welcome official guidelines specific to this high-risk population.

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.

Perioperative Care of Free Flap Patients

Microvascular free tissue transfer is an indispensable reconstructive option in head and neck reconstruction. Flap failure is relatively rare, but it is nonetheless very morbid and psychologically devastating to patients when it does occur. Further, complications after free tissue transfer to the head and neck remain common. There are numerous ongoing debates about various facets of preoperative, intraoperative, and postoperative care of patients undergoing free flap reconstruction of the head and neck, all ultimately searching for the optimal treatment algorithm to further improve flap success, minimize complications, and maximize patient outcomes. Herein, the authors review current literature surrounding optimal preoperative nutritional support, intraoperative vasopressor use, perioperative fluid management, use of antithrombotic agents, antibiotic use, and other facets of the care of head and neck free flap patients to provide a guide to surgeons.

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.

Quantification of BSA-loaded chitosan/oligonucleotide nanoparticles using reverse-phase high-performance liquid chromatography

Therapeutic proteins are administered subcutaneously because of their instability in the gastrointestinal tract. Current research suggests that polymeric-based nanoparticles, microparticles and liposomes are ideal nanocarriers to encapsulate proteins for disease management. In order to develop a successful drug delivery system, it is crucial to determine drug release profile and stability. However, the non-active excipients in polymeric formulations can influence the quantification of proteins in analytical techniques. This study investigated the effect of nine common polymers on quantification of bovine serum albumin (BSA) using RP-HPLC method. The technique offers advantages such as short analytical time, high accuracy and selectivity. In the meantime, the technique can be employed to separate proteins including BSA, insulin and pigment epithelium-derived factor (PEDF). Furthermore, the RP-HPLC method was applied to quantify the drug release pattern of a novel BSA-loaded nanoparticulate formulation in simulated gastric and intestinal fluids. The nanoparticles were formulated by natural polymer (chitosan) and oligonucleotide (Dz13Scr) using complex coacervation. The prepared particles were found to have small size (337.87 nm), low polydispersity index (0.338) and be positively charged (10.23 mV). The in vitro drug release patterns were characterised using the validated RP-HPLC method over 12 h. Graphical abstract ᅟ.

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.

Towards standardization of training and practice of reconstructive microsurgery: an evidence-based recommendation for anastomosis thrombosis prophylaxis

BACKGROUND

Despite significant improvements in survival rates, free flap failures still occur even in experienced hands and are most commonly due to arterial or venous thrombosis. In the absence of an evidence-based guideline on the prevention of thrombosis, we reviewed the literature to assess the evidence base for commonly used interventions aimed at its prevention.

METHODS

A comprehensive literature search was performed using the following keywords "free flap" and microsurgery with "pre-operative screening," "prevention of thrombosis," "ketorolac," "heparin," "low molecular weight heparin," "aspirin," "dextran," and "statins."

RESULTS

Thirteen clinical studies were included in this review. No high-level evidence is available to support any perioperative or postoperative interventions aimed at reducing the risk of flap thrombosis.

CONCLUSIONS

Higher level studies are needed to investigate the clinical use of antithrombotic medications in microsurgery; however, given the small failure rates in modern practice, these will need to be large multicenter trials in order to reach sufficient power.Level of Evidence: Level III, risk/prognostic study.

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.

Consensus Review of Optimal Perioperative Care in Breast Reconstruction: Enhanced Recovery after Surgery (ERAS) Society Recommendations

BACKGROUND

Enhanced recovery following surgery can be achieved through the introduction of evidence-based perioperative maneuvers. This review aims to present a consensus for optimal perioperative management of patients undergoing breast reconstructive surgery and to provide evidence-based recommendations for an enhanced perioperative protocol.

METHODS

A systematic review of meta-analyses, randomized controlled trials, and large prospective cohorts was conducted for each protocol element. Smaller prospective cohorts and retrospective cohorts were considered only when higher level evidence was unavailable. The available literature was graded by an international panel of experts in breast reconstructive surgery and used to form consensus recommendations for each topic. Each recommendation was graded following a consensus discussion among the expert panel. Development of these recommendations was endorsed by the Enhanced Recovery after Surgery Society.

RESULTS

High-quality randomized controlled trial data in patients undergoing breast reconstruction informed some of the recommendations; however, for most items, data from lower level studies in the population of interest were considered along with extrapolated data from high-quality studies in non-breast reconstruction populations. Recommendations were developed for a total of 18 unique enhanced recovery after surgery items and are discussed in the article. Key recommendations support use of opioid-sparing perioperative medications, minimal preoperative fasting and early feeding, use of anesthetic techniques that decrease postoperative nausea and vomiting and pain, use of measures to prevent intraoperative hypothermia, and support of early mobilization after surgery.

CONCLUSION

Based on the best available evidence for each topic, a consensus review of optimal perioperative care for patients undergoing breast reconstruction is presented.

CLINICAL QUESTION/LEVEL OF EVIDENCE

Therapeutic, V.

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.

A Comprehensive Approach to Lower Extremity Free-tissue Transfer

Background:

The purpose of this study was to introduce a comprehensive approach to lower extremity free-tissue transfer and report the clinical outcome that has been achieved with this approach.

Methods:

The comprehensive approach developed by the author includes patient selection, flap selection, selection of the recipient vessels, flap dissection, flap preparation, microvascular anastomosis, flap inset, immediate postoperative care, intermediate postoperative care, and further follow-up care. Each part of this approach has its own special considerations. In an 8-year period, 28 consecutive lower extremity free-tissue transfers were performed in 28 patients by the author. The clinical outcomes were recorded based on the success of free-tissue transfer, any reoperations related to the revision of microvascular anastomosis, and any partial or total flap loss during an 8-year follow-up.

Results:

All 28 lower extremity free-tissue transfers were performed successfully. All patients were discharged home once they tolerated dangling. No reoperations were needed for revision of microvascular anastomosis. No total or partial flap loss was encountered. Overall success of free-tissue transfer to the lower extremity in this series was 100%.

Conclusions:

An ideal outcome of free-tissue transfer to the lower extremity can be accomplished with this comprehensive approach developed by the author. With good surgical judgment, adequate microsurgical skill, step-by-step intraoperative execution, and a protocol-driven clinical practice, the reconstructive surgeon should be able to improve his or her success for free-tissue transfer to the lower extremity.

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.

Breast free flap complications related to haematoma formation - do the risks of multiple antithrombotics outweigh the benefits today?

Background Free flap reconstruction is today a common operation for many breast cancer patients, but local protocols for microsurgery still predict the use of antithrombotic agents. Reduced operation times and complication rates together with faster mobilisation, after introduction of perforator flaps, call for less comprehensive antithrombotic regimens. It was hypothesised that multiple antithrombotics was a risk factor for bleeding-related flap complications. Methods A retrospective cohort study was conducted to study the association between reoperation for haematoma and flap-related complications after free flap breast reconstruction. A combination of heparin, low-molecular-weight heparin and dextran were used as antithrombotics. A sub-analysis was performed to compare non-dextran to dextran treated patients. Results One hundred and thirty-nine patients were identified, reconstructed with 150 consecutive perforator free flaps to the breast. Reoperation for breast haematoma (13%) was associated with concomitant re-operation for venous congestion (8.6%) (p < 0.001), but also for flap thrombosis (2.9%) (p = 0.007), highlighting haematoma as a risk factor for flap-related complications. An increased rate of haematoma re-operations of the breast was noted among the flap-related complications in the dextran (n = 79), compared to the non-dextran group (p = 0.011). Conclusion The current study highlights the use of multiple antithrombotics as a risk factor for haematoma reoperation. Liberal use of drains and evacuation of breast haematomas are, therefore, indicated together with limitation of antithrombotic agents. The highly variable use of antithrombotic agents worldwide call for evidence-based guidelines in standardised free flap breast reconstruction.

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.

Intraoperative perfusion management impacts postoperative outcomes: an analysis of 682 autologous breast reconstruction patients

INTRODUCTION

Anesthetic management remains an understudied aspect of free autologous breast reconstruction. This study aims to critically examine intraoperative anesthetic management as it relates to free flap perfusion and its effect on major complications.

METHODS

A retrospective cohort study was performed examining all abdominally based free autologous breast reconstructions from 2005 to 2011 at a single institution. Analysis focused on perioperative care and specifically fluid administration, urine output (UOP), vasopressor administration, and case duration. Outcomes included major intraoperative and postoperative complications. A post-hoc analysis was performed to determine anesthetic factors associated with thrombotic events.

RESULTS

Overall, 682 patients (1033 flaps) were included. Patients with low UOP had lower rates of intraoperative fluid infusion rates/kg (p=0.0001), Estimated Blood Loss (EBL) (p=0.006) and pressor administration (p=0.03), but no significant differences were noted in intraoperative thrombotic events according to UOP. However, the below normal UOP cohort demonstrated a significant increased rate of delayed postoperative thromboses (p=0.03). A post hoc analysis of postoperative thrombotic events revealed that low rates of fluid resuscitation (OR=3.01, p=0.04) and low intraoperative UOP (OR=3.67, p=0.04) were independently associated with delayed thrombosis. A sub-analysis demonstrated that patients with ≥2 comorbidities and below normal UOP were at particular risk (any delayed thrombotic event OR=4.3, p=0.03; any delayed venous thrombosis OR=9.1, p=0.03).

CONCLUSIONS

This study demonstrates that intraoperative fluid under-resuscitation may place patients at increased risk for postoperative flap thrombosis, and low UOP is an important metric whereby intraoperative resuscitation should be gauged. Patients with comorbid conditions and below normal intraoperative UOP should be monitored particularly closely for delayed thrombotic events.

LEVEL OF EVIDENCE

Prognostic/risk category, level II.

The outcome of free tissue transfers in patients with hematological diseases: 20-year experiences in single microsurgical center

BACKGROUND

Free tissue transfers performed in patients with hematological diseases represent significant challenges for micro-surgeons. There are rare literatures that address the outcome in these patients. Therefore, we collected our database, analyzed the outcome, reliability, and related-management of microsurgical technique in the patients with hematological diseases.

METHODS

A retrospective chart review of 20 patients with hematological disorders who received free tissue transfers during 20-years period in a single microsurgical center was done. Eleven patients who received head and neck reconstruction were found to have hyperfibrinogenemia. Seven patients with reactive thrombocytosis after trauma, and two patients with leukemia had soft tissue defects in the upper and lower extremities. Twenty-six flaps were used for free tissue transfers. Intra-operatively all patients received intravenous 5,000 Ud of heparin post immediate reperfusion. Anti-coagulant medication such as Dextran-40 or prostaglandin-E1 (PGE1) was given postoperatively.

RESULTS

Twenty-three of the 26 free flaps survived without vascular compromise. Intra-operatively all patients received intravenous 5,000 Ud of heparin post immediate reperfusion, and anti-coagulant medication such as Dextran-40 or prostaglandin-E1 was given to the patients postoperatively. The three failed cases were found in patients with hyperfibrinogenemia and needed further reconstruction with another flap. The overall success rate was 88.5% (23/26).

CONCLUSIONS

Hematologic disorder is not a predicted factor of free flap failure. The key factors for success flap survival in patients with hematologic disorders include preoperative knowledge of the medical condition and monitoring potential post-operative complications, aggressive hematologist consultations, and meticulous non-traumatic surgical anastomosis.

Low molecular weight dextran provides similar optical coherence tomography coronary imaging compared to radiographic contrast media

BACKGROUND

Optical coherence tomography (OCT) coronary imaging requires displacement of red blood cells from the vessel lumen. This is usually accomplished using radiographic contrast. Low molecular weight dextran has low cost and is safe in low volumes. In the present study, we compared dextran with contrast for coronary OCT imaging.

METHODS

Fifty-one vessels in 26 patients were sequentially imaged using manual injection of radiographic contrast (iodixanol) and dextran. OCT images were analyzed at 1 mm intervals to determine the image clarity (defined as a visible lumen border > 270°) and to measure the lumen area and lumen diameter. To correct for the refractive index of dextran, the dextran area measurements were multiplied by 1.117 and the dextran length measurements were multiplied by 1.057.

RESULTS

A total of 3,418 cross-sections (1,709 with contrast and 1,709 with dextran) were analyzed. There were no complications related to OCT imaging or to contrast or dextran administration. Clear image segments were observed in 97.0% vs. 96.7% of the cross-sections obtained with contrast and dextran, respectively (P = 0.45). The mean lumen areas were also similar: 6.69 ± 1.95 mm(2) with iodixanol vs. 7.06 ± 2.06 mm(2) with dextran (correlation coefficient 0.984).

CONCLUSIONS

The image quality and measurements during OCT image acquisition are similar for dextran and contrast. Dextran could be used instead of contrast for OCT imaging, especially in patients in whom contrast load minimization is desired.