Vascular Complications and Free Flap Salvage in Head and Neck Reconstructive Surgery: Analysis of 150 Cases of Reexploration

An Institutional Analysis of Early Postoperative Free Tissue Transfer Takeback Procedures

BACKGROUND

 Postoperative free tissue transfer reexploration procedures are relatively infrequent but associated with increased overall failure rates. This study examines the differences between flaps requiring takeback versus no takeback, as well as trends in reexploration techniques that may increase the odds of successful salvage.

METHODS

 A retrospective review was conducted on all free tissue transfers performed at our institution from 2011 to 2022. Patients who underwent flap reexploration within 30 days of the original procedure were compared with a randomly selected control group who underwent free flap procedures without reexploration (1:2 cases to controls). Univariate and multivariate logistic regression analyses were performed.

RESULTS

 From 1,213 free tissue transfers performed in the study period, 187 patients were included in the analysis. Of the total flaps performed, 62 (0.05%) required takeback, and 125 were randomly selected as a control group. Free flap indication, flap type, reconstruction location, and number of venous anastomoses differed significantly between the two groups. Among the reexplored flaps, 8 (4.3% of the total) had a subsequent failure while 54 (87.10%) were salvaged, with significant differences in cause of initial flap failure, affected vessel type, and salvage technique.

CONCLUSION

 Free tissue transfers least prone to reexploration involved breast reconstruction in patients without predisposition to hypercoagulability or reconstruction history. When takeback operations were required, salvage was more likely in those without microvascular compromise or with an isolated venous injury who required a single exploratory operation.

The Impact of Venous Anastomosis Technique on Outcomes of Free Tissue Transfer to the Head and Neck

Objectives: To evaluate the impact of different techniques of microvascular venous anastomosis on the outcome of free tissue transfer to the head and neck. Methods: Retrospective case series of patients undergoing microvascular free tissue transfer (MFTT) from January 2006 to September 2021. Chi-square tests and t-tests were utilized to identify differences in flap outcomes by technique, and log-binomial regression analyses were utilized to identify differences in flap outcomes by technique. Results: A total of 1055 consecutive MFTTs were analyzed. One hundred four cases required a return to the operating room for any reason, and 19 were attributed to venous compromise (18.0%). Ultimately, there were 22 FTT failures requiring complete revision (2.1%). In total, 1055 MFTTs involved 1352 venous anastomoses, ranging from 1 to 3 anastomoses in each case. End-to-end (ETE) was used 1040 times (76.9%) and end-to-side (ETS) 204 times (15.0%). The calculated risk ratio for venous complication for ETS compared with ETE was 1.17 (0.34-3.98). A microvascular coupler was used in 355 cases (33.6%). The calculated risk ratio for coupler compared with suture anastomoses was 0.92 (0.35-2.39). Conclusions: There were no significant difference in regard to outcomes of MFTT when comparing ETE with ETS, nor when comparing coupler with suture anastomoses.

Continuous Monitoring of Buried Free Bone Flap Microcirculation Using a Near-Infrared Spectroscopy System

SUMMARY

Postoperative evaluation of free flaps remains a challenging task. The current accepted standard for diagnosis of vascular compromise remains clinical observation. In recent years, near-infrared spectroscopy (NIRS) has been widely used as a noninvasive objective monitoring tool for postoperative evaluation of soft-tissue flaps. However, methods for monitoring bone flaps remain inadequate. In this study, NIRS was applied for the first time to monitor free buried bone flaps that were used for mandibular reconstruction. The penetrating property of NIRS was used to measure the tissue oxygenation index (TOI) of deep tissues, which reflected the microcirculatory status of the tissues. Changes in TOI values were monitored continuously in 59 cases of free bone flaps up to 72 hours after surgery. Five cases of vascular compromise were noted by clinical observation. Two fibula flaps were total failures, one of which showed a sharp decrease in TOI value to 45% in a short period of time; the other showed a continual gradual decrease to 55%. The observed sudden (<50%) and continuous (>10%) decreases in TOI values suggest that more attention should be paid to revision surgical procedures. The authors conclude that NIRS holds promise as an objective and valid method for clinical evaluation of buried bone flaps.

Standardized Pre-clinical Surgical Animal Model Protocol to Investigate the Cellular and Molecular Mechanisms of Ischemic Flap Healing

BACKGROUND

Some of the most complex surgical interventions to treat trauma and cancer include the use of locoregional pedicled and free autologous tissue transfer flaps. While the techniques used for these reconstructive surgery procedures have improved over time, flap complications and even failure remain a significant clinical challenge. Animal models are useful in studying the pathophysiology of ischemic flaps, but when repeatability is a primary focus of a study, conventional in-vivo designs, where one randomized subset of animals serves as a treatment group while a second subset serves as a control, are at a disadvantage instigated by greater subject-to-subject variability. Our goal was to provide a step-by-step methodological protocol for creating an alternative standardized, more economical, and transferable pre-clinical animal research model of excisional full-thickness wound healing following a simulated autologous tissue transfer which includes the primary ischemia, reperfusion, and secondary ischemia events with the latter mimicking flap salvage procedure.

RESULTS

Unlike in the most frequently used classical unilateral McFarlane's caudally based dorsal random pattern skin flap model, in the herein described bilateral epigastric fasciocutaneous advancement flap (BEFAF) model, one flap heals under normal and a contralateral flap-under perturbed conditions or both flaps heal under conditions that vary by one within-subjects factor. We discuss the advantages and limitations of the proposed experimental approach and, as a part of model validation, provide the examples of its use in laboratory rat (Rattus norvegicus) axial pattern flap healing studies.

CONCLUSIONS

This technically challenging but feasible reconstructive surgery model eliminates inter-subject variability, while concomitantly minimizing the number of animals needed to achieve adequate statistical power. BEFAFs may be used to investigate the spatiotemporal cellular and molecular responses to complex tissue injury, interventions simulating clinically relevant flap complications (e.g., vascular thrombosis) as well as prophylactic, therapeutic or surgical treatment (e.g., flap delay) strategies in the presence or absence of confounding risk factors (e.g., substance abuse, irradiation, diabetes) or favorable wound-healing promoting activities (e.g., exercise). Detailed visual instructions in BEFAF protocol may serve as an aid for teaching medical or academic researchers basic vascular microsurgery techniques that focus on precision, tremor management and magnification.

Reliability of Postoperative Free Flap Monitoring with a Novel Prediction Model Based on Supervised Machine Learning

BACKGROUND

Postoperative free flap monitoring is a critical part of reconstructive microsurgery. Postoperative clinical assessments rely heavily on specialty-trained staff. Therefore, in regions with limited specialist availability, the feasibility of performing microsurgery is restricted. This study aimed to apply artificial intelligence in postoperative free flap monitoring and validate the ability of machine learning in predicting and differentiating types of postoperative free flap circulation.

METHODS

Postoperative data from 176 patients who received free flap surgery were prospectively collected, including free flap photographs and clinical evaluation measures. Flap circulation outcome variables included normal, arterial insufficiency, and venous insufficiency. The Synthetic Minority Oversampling Technique plus Tomek Links (SMOTE-Tomek) was applied for data balance. Data were divided into 80%:20% for model training and validation. Shapley Additive Explanations were used for prediction interpretations of the model.

RESULTS

Of 805 total included flaps, 555 (69%) were normal, 97 (12%) had arterial insufficiency, and 153 (19%) had venous insufficiency. The most effective prediction model was developed based on random forest, with an accuracy of 98.4%. Temperature and color differences between the flap and the surrounding skin were the most significant contributing factors to predict a vascular compromised flap.

CONCLUSIONS

This study demonstrated the reliability of a machine-learning model in differentiating various types of postoperative flap circulation. This novel technique may reduce the burden of free flap monitoring and encourage the broader use of reconstructive microsurgery in regions with a limited number of staff specialists.

A Retrospective Matched-Pair Analysis of Long-term Outcomes after Successful Lower Extremity Free Flap Salvage

BACKGROUND

 Pedicle occlusion with total free flap loss after microvascular lower extremity reconstruction is a considerably rare yet devastating complication. Fortunately, in the majority of cases, emergency salvage takebacks of compromised free flaps are initiated in a timely manner. In this report, we present our analysis of long-term outcomes following transient vascular compromise mitigated through successful free flap salvage in the lower extremity.

METHODS

 We performed a single-center retrospective matched-pair analysis of 46 patients with lower extremity free flap reconstructions. Cases underwent successful revisions of microvascular compromise (n = 23), whereas controls had uneventful postoperative courses (n = 23). Patient-reported outcome questionnaires and physical evaluations were used to assess general quality of life, functional outcomes, and cosmesis (Lower Extremity Functional Scale [LEFS], Lower Limb Outcomes Questionnaire [LLOQ], Short Form 36 (SF-36), Vancouver Scar Scale [VSS]). The mean follow-up time was 4.4 years.

RESULTS

 The health-related quality of life assessed by the SF-36 did not differ significantly between both groups in any of the subscales (p ≥ 0.15 for all subscales). Functional outcomes did not show significant differences between both groups according to the LEFS (p = 0.78) and LLOQ (p = 0.45). The overall scar appearance assessed by the VSS showed significantly poorer cosmesis in the re-exploration group (p = 0.014).

CONCLUSION

 Salvage of compromised free flaps in the lower extremity yields similar long-term outcomes compared to noncompromised free flaps with regard to function and quality of life. However, free flap revisions may lead to impaired scar formation. This study provides further evidence that the opportunity for urgent re-exploration is indispensable.

Intraoperative Enteral Nutrition Feeding in Free-Flap Healing after Reconstruction Surgery for Head and Neck Cancers

OBJECTIVE

To investigate the beneficial outcomes of intraoperative enteral feeding in free-flap regeneration after extended head and neck cancer resection and flap reconstruction surgery.

STUDY DESIGN

A pilot randomized, double-blind, placebo-controlled clinical trial.

SETTING

Single tertiary care center.

METHODS

Patients with advanced head and neck cancers requiring radical tumor resections and free-flap reconstruction were randomly assigned to receive intraoperative enteral nutrition feeding (100 kcal/100 mL at 10-20 mL/h) via a nasogastric tube during free-flap reconstruction (n = 28) or continue fasting (n = 28). The primary outcome was impaired free-flap regeneration that required surgical reintervention within 90 days after the operation. Participants were enrolled between April 2020 and January 2022; the 90-day follow-up ended in April 2022.

RESULTS

The incidence of total or partial flap failure was similar between the 2 groups (14.2% or n = 4 in each group), but the rate of wound dehiscence or edge necrosis was significantly reduced in the feeding group (n = 6 vs 0 for fasting vs feeding; absolute risk reduction, 25.0% [95% confidence interval, 6.9-43.0]%; p = 0.022). Hospital stay length was shorter (p = 0.042) and hand grip strength was better preserved (p = 0.025) in the feeding group. Plasma concentrations of interleukin (IL)-6 and IL-8 after the operation increased significantly more in the fasting group. Perioperative adverse events did not differ between the 2 groups.

CONCLUSION

Perioperative enteral feeding is a simple, safe, and effective approach to improve perioperative systemic catabolism and proinflammatory reactions, thereby enhancing early wound regeneration after major operations.

Thrombophilia and Preoperative Deep Venous Thrombosis and Their Effect on Free Flap Survival: A Scoping Review

Background: A proper preoperative planning is essential to prevent flap failure. However, venous workup for flaps has not been commonly performed or utilized as a preoperative screening tool. A scoping review was conducted to explore preoperative venous system screening, including deep vein thrombosis diagnosis, and its effect on flap survival rate. This review identified existing gaps of knowledge and emphasized potential research areas for future studies. Methods: Two independent reviewers searched 3 electronic databases from inception to September 2020. Retrieved appropriate articles were selected systematically by title, abstract, and full review of the article. Studies were included if they enrolled patients who had thrombophilia or deep venous thrombosis (DVT) preoperatively and had undergone a free flap reconstruction. For eligible studies, the following information was extracted: basic demographics (sex, age, comorbidities), preoperative scans type, free flap type, clotting mode (causes), wound type, and flap survival. Results: Seventeen articles were found eligible for this review. Traumatic aetiology was found in 63 (33.6%) patients, while 124 (66.3%) patients had a non-traumatic aetiology. Preoperative screening for patients with non-traumatic aetiology was reported in 119 patients. In these patients, the flap survived in 107 (89.91%) patients. Four studies investigating patients with traumatic DVT aetiology, 60 patients (out of 63) had a preoperative computed tomography angiography or duplex. Those patients had 100% flap survival rates. Conclusion: Further investigations are required to identify venous thrombosis incidence in patients with non-traumatic thrombosis aetiology as this cohort of patients is at high risk of flap failure. Finally, the prognostic validity of available preoperative screening tools to identify high-risk patients should be assessed, such as imaging techniques, which would include venous duplex scanning, may prevent failure in free flap surgery.

Postoperative free flap monitoring in reconstructive surgery-man or machine?

Free tissue transfer is widely used for the reconstruction of complex tissue defects. The survival of free flaps depends on the patency and integrity of the microvascular anastomosis. Accordingly, the early detection of vascular comprise and prompt intervention are indispensable to increase flap survival rates. Such monitoring strategies are commonly integrated into the perioperative algorithm, with clinical examination still being considered the gold standard for routine free flap monitoring. Despite its widespread acceptance as state of the art, the clinical examination also has its pitfalls, such as the limited applicability in buried flaps and the risk of poor interrater agreement due to inconsistent flap (failure) appearances. To compensate for these shortcomings, a plethora of alternative monitoring tools have been proposed in recent years, each of them with inherent strengths and limitations. Given the ongoing demographic change, the number of older patients requiring free flap reconstruction, e.g., after cancer resection, is rising. Yet, age-related morphologic changes may complicate the free flap evaluation in elderly patients and delay the prompt detection of clinical signs of flap compromise. In this review, we provide an overview of currently available and employed methods for free flap monitoring, with a special focus on elderly patients and how senescence may impact standard free flap monitoring strategies.

Surgical and demographic predictors of free flap salvage after takeback: A systematic review

BACKGROUND

Microsurgical free tissue transfer (FTT) is a widely employed surgical modality utilized for reconstruction of a broad range of defects, including head and neck, extremity, and breast. Flap survival is reported to be 90%-95%. When FTT fails, salvage procedures aim at establishing reperfusion while limiting ischemia time-with salvage rates between 22% and 67%. There are limited data-driven predictors of successful salvage present in the literature. This systematic review aims to identify predictors of flap salvage.

METHODS

A systematic literature review was conducted per PRISMA guidelines. Articles included in the final analysis were limited to those investigating FTT salvage procedures and included factors impacting outcomes. Cohort and case series (>5 flaps) studies up until March 2021 were included. Chi-square tests and linear regression modeling was completed for analysis.

RESULTS

The patient-specific factors significantly associated with salvage included the absence of hypercoagulability (p < .00001) and no previous salvage attempts (p < .00001). Case-specific factors significantly associated with salvage included trunk/breast flaps (p < .00001), fasciocutaneous/osteocutaneous flaps (p = .006), venous compromise (p < .00001), and shorter time from index procedure to salvage attempt (R = .746). Radiation in the head and neck population was significantly associated with flap salvage failure.

CONCLUSIONS

Given the complexity and challenges surrounding free flap salvage procedures, the goal of this manuscript was to present data helping guide surgical decision-making. Based on our findings, patients without documented hypercoagulability, no previous salvage attempts, fasciocutaneous/osteocutaneous flaps, trunk/breast flaps, and a shorter time interval post-index operation are the best candidates for a salvage attempt.

How do i salvage that flap?; An evidence-based primer on salvage techniques for head & neck microvascular free flaps

Interventional strategies for dealing with microvascular free flap failure are varied among institutions and even individual surgeons. This systematic review aims to identify the published methods for salvaging a failing free flap and provide surgeons with a comprehensive toolset for successful intervention. A title and abstract search of the PubMed, Embase, and Web of Science databases was performed. 1694 abstracts were screened by three reviewers according to Prisma guidelines. 62 full text articles meeting inclusion criteria detailed techniques which were separated into the categories of thrombectomy, thrombolysis, leech therapy, vascular fistula, and an "other" category outlining techniques which did not fit into the prior framework. Assessment of the efficacy of individual salvage techniques is limited due to limited empirical data, however, the approach to successful salvage should be based on timely identification of flap compromise, followed by the implementation of one or several of the aforementioned techniques.

Evaluation of the long-term results of vascular anastomosis using polyurethane adhesive and shape-memory stent in the rat carotid artery model

INTRODUCTION

In free flaps, 5%-10% of complications are related to failure of sutured vascular anastomoses. Adhesive-based microvascular anastomoses are potential alternatives but are associated with failure rates of 70% in research studies. VIVO is a new adhesive with slow biodegradation within 6 months that has shown a 100% patency rate in research studies over 2 h observation time but long-term patency has not been evaluated. The authors hypothesize that VIVO will enable a reliable microvascular procedure comparable to sutured anastomoses over a 28-day period.

MATERIALS AND METHODS

The right common carotid artery of 60 male Sprague Dawley rats, ~450 g, were used for microvascular end-to-end anastomosis. VIVO was applied with reduced sutures with a temporary catheter in one group and in the other with a custom-shaped memory stent. Anastomoses with eight interrupted sutures served as control. All groups were n = 20. Anastomosis time and bleeding were recorded for each procedure. Doppler flowmetry was performed 20 min, 1, 10, and 28 days postoperatively. Postmortem toluidine staining was used for semi-quantitative analysis of stenosis, thrombosis, necrosis, and aneurysm formation by histologic evaluation.

RESULTS

No occlusion was detected 20 min and 1 day postoperative, and after 28 days of observation in all anastomoses. The anastomosis time of the VIVO with catheter group was about 32% significantly faster than the VIVO with stent group. In the VIVO group with stent, the bleeding time was ~80% shorter than in the control group with 2.1 ± 0.3 and VIVO with catheter 2.0 ± 0.5 (p ≤ .001 each). Minor and nonsignificant stent-associated thrombus formation and stent-typical intraluminal stenosis were detected exclusively in the VIVO with stent group.

CONCLUSION

Within the limitations of a rat study, the use of VIVO in anastomosis showed promising results. VIVO with catheter was found to be advantageous.

Success and Outcomes Following a Second Salvage Attempt for Free Flap Compromise in Patients Undergoing Head and Neck Reconstruction

Importance

Incidence of perioperative free flap compromise is low, with successful salvage in up to 70%. When the flap is compromised a second time, the value of intervening is unknown.

Objective

To assess the outcomes of a second revascularization attempt for compromised free flaps.

Design, Setting, and Participants

This multicenter retrospective medical record review included patients undergoing head and neck reconstruction with free flaps at 6 US medical centers from January 1, 2000, through December 30, 2020. Patients were 18 years or older with a history of head and neck defects from cancer, osteoradionecrosis, or other wounds. Of 3510 flaps identified, 79 were successfully salvaged once, became compromised a second time, and underwent attempted salvage.

Main Outcome and Measure

Flaps with a history of initial compromise and successful revascularization demonstrating second episodes of compromise followed by second salvage attempts.

Results

A total of 79 patients (mean age, 64 years; 61 [77%] men) were included in the analysis. Of the 79 flaps undergoing second salvage attempts, 24 (30%) survived while 55 (70%) demonstrated necrosis. Arterial or venous thrombectomy was performed in 17 of the 24 (71%) flaps that survived and 23 of the 55 (42%) flaps demonstrating necrosis (odds ratio, 3.38; 95% CI, 1.21-9.47). When venous compromise was encountered, changing the anastomotic vein was associated with decreased survival compared with not changing the vein (29 of 55 [53%] flaps vs 10 of 24 [42%] flaps); vein revision to an alternative branch was completed in 1 of the 24 (4%) flaps that survived and 19 of the 55 (35%) flaps with necrosis (odds ratio, 0.08; 95% CI, 0.00-0.60). Factors that were not associated with flap survival following second salvage attempts included flap type, cause of flap failure, postoperative complications, patient comorbidities, and heparin administration after second salvage.

Conclusions and Relevance

In this cohort study, second salvage was successful in 30% of free flaps. Flaps that underwent arterial or venous thrombectomy demonstrated better survival, while vein revision to neighboring branch veins was associated with worse flap outcomes.

Venous Size Discrepancy Is a Critical Factor When Using Superficial Temporal Vessels as Recipient Vessels for Free Flaps

BACKGROUND

 Superficial temporal vessels have been used successfully as recipient vessels for head and neck reconstruction. This study evaluates the impact of several treatment variables on flap failure and take-back rate when using these recipient vessels.

METHODS

 We conducted a retrospective study of all microsurgical reconstructions using superficial temporal vessels as recipient vessels in a period of 10 years. Variables collected included previous treatments (radiotherapy, chemotherapy, neck dissection, free flap reconstruction), type of flaps used (soft tissue, osteocutaneous), and vessel size discrepancy between donor and recipient vessels.

RESULTS

 A total of 132 patients were included in the study. The flap success rate was 98.5%. The take-back rate was 10.6%. The most frequent reason for take-back was venous congestion secondary to thrombosis. None of the studied variables was associated with flap failure. Reconstructions using osteocutaneous flaps and vein diameter discrepancy (ratio ≥ 2:1) had significantly higher take-back rates.

CONCLUSION

 Flaps with a significant size discrepancy between donor and recipient veins (ratio ≥ 2:1) and fibula flaps (compared with soft tissue flaps) were associated with a higher risk of take-back. It is crucial to minimize venous engorgement during flap harvest and anastomosis, and limit vein redundancy during flap in-setting.

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.

Organ preservation surgery for pyriform sinus carcinoma with vocal cord fixation: functional and oncological outcomes

BACKGROUND

Pyriform sinus carcinoma with vocal cord fixation is stratified as stage T3 and above, and non-surgical treatment is generally preferred according to the guidelines, aiming to preserve laryngeal function. However, long-term survival is often compromised by deep infiltration of the tumor. Vertical hemipharyngolaryngectomy (VHPL) was previously reported to be a feasible surgical approach for organ preservation. The aim of this study was to evaluate the functional and oncological outcomes of VHPL in patients.

METHODS

Patients who underwent VHPL type II (total VHPL, which includes the removal of a vertical section of the thyroid cartilage through the anterior commissure to the upper border of the cricoid cartilage) for pyriform sinus cancer with vocal cord fixation at the authors' institute between 1999 and 2015 were retrospectively analyzed. Functional outcomes concerning swallowing and decannulation were evaluated. Successful functional preservation was defined as laryngeal preservation as well as oral realimentation and decannulation within 6 months after surgery. The oncological outcomes were measured by overall survival (OS) and disease-free survival (DFS) with Kaplan-Meier curves and comparisons were performed between the VHPL-treated patients and patients who underwent non-surgical treatment within the same period.

RESULTS

A total of 23 patients (stage T3, 17 patients; stage T4, 6 patients) whose initial treatment was VHPL type II were studied, and a cohort of 123 patients was selected as the control group. Pedicle and free flap reconstructions were performed on 12 and 11 patients, respectively. Postoperative radiation and chemoradiation was performed on 14 and 3 patients, respectively. Flap failure and pharyngeal fistula were detected in 2 and 5 patients, respectively. Oral realimentation and decannulation within 6 months were achieved in 82.6% (19 patients) and 87.0% (20 patients) of patients, respectively, and the total functional preservation rate of the study cohort at 6 months was similar to that of the control cohort. (78.3% vs. 82.9%, p = 0.28). After a median follow-up period of 49 months, 9 recurrences and 8 deaths had occurred in the study cohort. According to the Kaplan-Meier analysis, the study cohort had superior DFS (5-year DFS 60.3% vs. 44.6%, p = 0.04) and similar OS (5-year OS 63.8% vs 57.0% p = 0.28) compared with those in the control group.

CONCLUSION

VHPL yielded favorable oncological and functional outcomes in patients with unilateral pyriform sinus carcinoma and vocal cord fixation.

Outcomes of Re-exploration Procedures After Head and Neck Free Flap Reconstruction

This study was conducted to evaluate the outcomes of re-exploration procedures done after head and neck microvascular flap reconstructions. This is a retrospective review of 109 flaps in 106 patients (three patients had two flaps each) that underwent re-exploration procedures in 1001 consecutive free flap surgeries. The outcome was analysed in terms of the type of the flaps, re-exploration rate, flap salvage rate and overall flap success rate. Free radial forearm (RFF) was the commonest flap done (354, 35.3%). One hundred nine flaps underwent re-exploration procedures in 106 patients. Out of this, 79 flaps could be salvaged, and 30 flaps failed. There were also another ten flaps, which failed without any re-exploration. The overall re-exploration rate was 10.8%. The flap salvage rate was 72.4%. The overall flap success rate was 96.1%. Nearly three-fourths of the flaps with vascular compromise can be successfully salvaged with appropriate and timely intervention.

Head and neck free-flap salvage

PURPOSE OF REVIEW

To highlight three clinical arenas in which head and neck free-flap compromise is encountered and acted upon: nonoperative, operative and postoperative realms.

RECENT FINDINGS

Time to identification and intervention is paramount to successful free-flap salvage. Surgical microvascular revision remains chief amongst strategies to revert vascular compromise of a free-flap. Adjuncts, such as thrombolytics and systemic anticoagulation have an important role in the complex work of microvascular free tissue care. Venous congestion of free flaps holds favorable for salvage when compared with arterial insufficiency.

SUMMARY

Vascular compromise of head and neck free flaps is a rare and feared event for microvascular surgeons, with successful transfers rates approaching above 95%. Success in salvage is dependent on prompt identification of tissue compromise and timely, directed interventions to re-establish tissue perfusion.

Primary thrombolysis for free flap surgery in head and neck reconstruction: a case report and review

The use of free flaps is an essential and reliable method of reconstruction in complex head and neck defects. Flap failure remains the most feared complication, the most common cause being pedicle thrombosis. Among other measures, thrombolysis is useful when manual thrombectomy has failed to restore flap perfusion, in the setting of late or established thrombosis, or in arterial thrombosis with distal clot propagation. We report a case of pedicle arterial thrombosis with distal clot propagation which occurred during reconstruction of a maxillectomy defect, and was successfully treated with thrombolysis using recombinant tissue plasminogen activator. We also review the literature regarding the use of thrombolysis in free flap surgery, and propose an algorithm for the salvage of free flaps in head and neck reconstruction.

Management of Flap Failure After Head and Neck Reconstruction: A Systematic Review and Meta-analysis

OBJECTIVE

To systematically review management of flap loss in head and neck construction with free tissue transfer as compared with locoregional flap or conservative management.

DATA SOURCES

Medline, Embase, Scopus, Cochrane Central Register of Controlled Trials, Cochrane Database of Systematic Reviews, and ClinicalTrials.gov were searched up to October 2019.

REVIEW METHODS

Candidate articles were independently reviewed by 2 authors. Articles were considered eligible if they included adequate reporting of flap management after flap loss and outcomes for survival of reconstruction, length of hospitalization, and perioperative complications.

RESULTS

A total of 429 patients had acute flap failure in the perioperative period. The overall success with a secondary free flap was 93% (95% CI, 0.89-0.97; n = 26 studies, I² = 12.8%). There was no difference in hospitalization length after secondary reconstruction between free tissue transfer and locoregional flaps or conservative management (relative risk of hospitalization ≥2 weeks, 96%; 95% CI, 0.80-1.14; n = 3 studies, I² = 0). The pooled relative risk of perioperative complications following free tissue transfer was 0.60 when compared with locoregional flap or conservative management (95% CI, 0.40-0.92; n = 5 studies, I² = 0).

CONCLUSION

Salvage reconstruction with free tissue transfer has a high success rate. Second free flaps following flap failure had a similar length of hospitalization and lower overall complication rate than locoregional reconstruction or conservative management. A second free tissue transfer, when feasible, is likely a more reliable and effective procedure for salvage reconstruction.

The Effect of Smoking on the Postoperative Course After Head and Neck Reconstruction With a Vascularized Free Flap: A Retrospective Study

OBJECTIVES

The objective of the present study is to determine the impact of smoking on hospital and intensive care unit stay, need for surgical reintervention, Portsmouth Physiological and Operative Severity Score for the enumeration of Mortality and morbidity, and surgical complications after head and neck reconstructions.

METHODS

All 153 patients who underwent head and neck reconstructions with free tissue transfer at the department of oral and maxillofacial surgery at the University Hospitals of Leuven between January 1, 2015 and December 31, 2018 were enrolled in this retrospective cohort study. Data from medical charts were extracted. Univariate and multiple regression analyses were performed. A level of significance of P < 0.05 (α = 0.05) was used.

RESULTS

Smoking was not associated with Portsmouth Physiological and Operative Severity Score for the enumeration of Mortality and morbidity, hospital or ICU stay, the incidence of postoperative complications in both flap and donor site, or surgical reintervention.

CONCLUSIONS

Regarding the outcomes included in this study, smoking status should not be considered as a critical factor in patient selection for head and neck reconstructions with a vascularized free flap.

Quantifying the Limitations of Clinical and Technology-based Flap Monitoring Strategies using a Systematic Thematic Analysis

Background

Multiple techniques exist to monitor free flap viability postoperatively, varying with practical and personal preference, yet the limitations of each technique remain unquantified. This systematic review aims to identify the most commonly reported limitations of these techniques in clinical practice.

Methods

A systematic review was conducted according to PRISMA guidelines using MEDLINE, EMBASE, and Web of Science with search criteria for postoperative free flap monitoring techniques. Search results were independently screened using defined criteria by two authors and a senior clinician. Limitations of the techniques found in the discussion section of eligible articles were recorded and categorized using thematic analysis.

Results

A total of 4699 records were identified. In total, 2210 articles met the eligibility criteria and were subsequently reviewed, with 195 papers included in the final analysis. The most frequently reported limitations of clinical monitoring were interpretation requiring expertise (25% of related papers), unsuitability for buried flaps (21%), and lack of quantitative/objective values (19%). For noninvasive technologies, the limitations were lack of quantitative/objective values (21%), cost (16%), and interpretation requiring expertise (13%). For invasive technologies, the limitations were application requiring expertise (25%), equipment design and malfunction (13%), and cost (13%).

Conclusions

This is the first systematic review to quantify the limitations of different flap monitoring techniques, as reported in the literature. This information may enhance the choice in monitoring strategy for a reconstructive service, and inform the development and refinement of new flap monitoring technologies.

Consensus of free flap complications: Using a nomenclature paradigm in microvascular head and neck reconstruction

BACKGROUND

We aim to define a set of terms for common free flap complications with evidence-based descriptions.

METHODS

Clinical consensus surveys were conducted among a panel of head and neck/reconstructive surgeons (N = 11). A content validity index for relevancy and clarity for each item was computed and adjusted for chance agreement (modified kappa, K). Items with K < 0.74 for relevancy (i.e., ratings of "good" or "fair") were eliminated.

RESULTS

Five out of nineteen terms scored K < 0.74. Eliminated terms included "vascular compromise"; "cellulitis"; "surgical site abscess"; "malocclusion"; and "non- or mal-union." Terms that achieved consensus were "total/partial free flap failure"; "free flap takeback"; "arterial thrombosis"; "venous thrombosis"; "revision of microvascular anastomosis"; "fistula"; "wound dehiscence"; "hematoma"; "seroma"; "partial skin graft failure"; "total skin graft failure"; "exposed hardware or bone"; and "hardware failure."

CONCLUSION

Standardized reporting would encourage multi-institutional research collaboration, larger scale quality improvement initiatives, the ability to set risk-adjusted benchmarks, and enhance education and communication.

Partial and Total Flap Failure after Fibula Free Flap in Head and Neck Reconstructive Surgery: Retrospective Analysis of 180 Flaps over 19 Years

Fibula free flap (FFF) is widely used in head and neck reconstructive surgery and is considered as a standard and therapy of choice after ablative cancer surgery. The aim of this retrospective monocenter study was to determine the success rates of fibula free flaps for jaw reconstruction after ablative tumor surgery. The disease course of patients who underwent jaw reconstructive surgery with FFF from January 2002 to June 2020 was evaluated regarding the flap success rate. Flap failure was analyzed in detail and categorized into two groups: partial flap failure (PFF) and total flap failure (TFF). A total of 180 free fibular flaps were performed over the last 19 years and a total of 36 flap failures were recorded. TFF occurred in n = 20 (56.6%) and PFF in n = 16 cases (44.4%) cases. No statistically significant differences were found concerning patients' age at flap transfer, sex, BMI, ASA-Score, preoperative non-virtual or virtual surgical planning (non-VSP vs. VSP), and time of reconstruction (immediately vs. delayed). Duration of hospitalization shows statistically significant differences between both groups (p = 0.038), but no differences concerning operating time and duration on Intensive Care Unit (ICU). Partial flap failure appears to be underreported in literature. Sub- and complete failure of the skin paddle leads to clinical complaints like uncovered bone segments and plate exposure. Partial or complete FFF failure lead to infections on the recipient site and prolonged wound healing and therefore may cause a delay of the beginning of adjuvant radiation therapy (RT). PFF of hard tissue can be induced by RT.

Vein Grafting in Microsurgical Lower Extremity Reconstruction: Outcome Analysis of Primary versus Secondary Salvage Procedures

BACKGROUND

 Many microsurgeons fear high complication rates and free flap loss when vein grafting is necessary to restore blood flow at the recipient site. The aims of this study were to comparatively analyze surgical outcomes of interposition vein grafts (VG) in microsurgical primary lower extremity reconstruction and secondary salvage procedures.

METHODS

 A retrospective study was conducted on 58 patients undergoing free flap transfers with vein grafting for primary lower extremity reconstruction (cohort 1) and secondary salvage procedures (cohort 2) between 2002 and 2016. A matched-pair analysis of both cohorts and 58 non-VG flaps was performed. Patient data, preoperative conditions, flap and vein graft characteristics, postoperative outcomes such as flap failure, thrombosis, and wound complications were analyzed.

RESULTS

 A total of 726 free flap transfers were performed. In total, 36 primary reconstructions (5%) utilized 41 interposition VG (cohort 1). Postoperative vascular compromise was observed in 65 free flaps (9%). In total, 22 out of 65 secondary salvage procedures (33.8%) utilized 26 interposition VG (cohort 2). Two total flap losses occurred in each cohort (5.6 vs. 9.1%; p = 0.63). Postoperative complications were observed in 38.9% of free flaps in cohort 1 and 72.7% in cohort 2 (p = 0.01). Takeback for microvascular compromise was comparable in both cohorts (19.4 vs. 22.7%; p = 0.75). Microvascular complications occurred more often in cohort 2 (22.7%) than in cohort 1 (8.3%; p = 0.28). Lower extremity salvage rates were high among both cohorts (94.4 vs. 90.9%; p = 0.63). Matched-pair analysis did not show any relevant differences on takebacks and flap loss (p = 0.32 and p = 1.0).

CONCLUSION

 In complex lower extremity reconstructions, VG can be performed with acceptable complication rates and outcomes in primary and especially in salvage cases. With careful planning and a consistent surgical protocol, VG can provide reliable success rates in limb salvage.

Mobile Smartphone Thermal Imaging Characterization and Identification of Microvascular Flow Insufficiencies in Deep Inferior Epigastric Artery Perforator Free Flaps

BACKGROUND

Mobile smartphone thermal imaging (MTI) devices correlate with blood flow, which makes them appealing adjuncts during reconstructive surgery. MTI was assessed in the setting of deep inferior epigastric artery perforator (DIEAP) free flaps. We hypothesized that MTI can be a surrogate for blood flow to identify microvascular flow insufficiencies.

METHODS

Nineteen patients underwent 30 DIEAP flaps for breast reconstruction. Images were obtained preoperatively, intraoperatively, and at instances of concern for flap viability. Three groups were evaluated: normal DIEAP flaps (NDFs), flaps with arterial insufficiency (AI), and flaps with venous congestion (VC).

RESULTS

All flaps were successful. There were significant temperature increases from max ischemia (24.5 ± 2.1°C) to 1 min after anastomosis (27.2 ± 1.6°C, P < 0.001). NDFs continued to warm until the final MTI was taken when leaving the operating room. There were no differences between MTI flap temperatures before transfer to the chest and after completion of microanastomosis. With questionable flap viability, VC and AI temperatures were found to be significantly colder than the NDF group (28.3 ± 1.9°C versus 32.2 ± 1.8°C, P = 0.003) in the VC group and (27.2 ± 0.7°C versus 32.2 ± 1.8°C, P = 0.001) in the AI group. After correction of the identified flow insufficiency, VC and AI rewarmed and temperatures were no different compared with NDF.

CONCLUSIONS

MTI recognizes microanastomotic failure and is a practical adjunct in the evaluation of free flap perfusion.

Risk Factors for and Cost Implications of Free Flap Take-backs: A Single Institution Review

OBJECTIVE/HYPOTHESIS

For patients undergoing microvascular free tissue transfer (MFTT), we evaluated risk factors and financial implications of operating room (OR) take-back procedures.

STUDY DESIGN

Retrospective review at a tertiary care center.

METHODS

Patients who underwent MFTT for head and neck reconstruction from 2011 to 2018 were identified. We compared hospital length of stay and overall costs associated with OR take-back procedures. Multivariable regression analysis evaluated factors associated with OR take-backs during the same hospitalization.

RESULTS

A total of 727 free flaps were reviewed, and 70 OR take-backs (9.6%) were identified. Mean total length of stay (LOS) in the ICU was 3.4 days versus 6.7 days for non-take-back and take-back flaps, respectively (P < .001). Mean total LOS on the regular floor was 6.3 days versus 13.1 days, respectively (P < .001). This resulted in a cost differential of $33,507 (94.3% increase relative to non-take-back flaps). The total cost associated with an OR take-back was $39,786. Hematomas were the most common cause of take-backs and wound dehiscence was associated with the highest costs. On multivariable analysis, higher ASA class (OR, 2.06; 95% CI, 1.11-3.99; P = .026) and shorter ischemia times (OR, 0.52; 95% CI, 0.29-0.95; P = .030) were independently associated with increased risk of take-backs.

CONCLUSIONS

OR take-backs infrequently occur but are associated with a significant increase in financial burden when compared to free flap cases not requiring OR take-back. The large majority of the cost differential lies in a substantial increase of ICU and floor LOS for take-back flaps when compared to non-take-back flaps.

LEVEL OF EVIDENCE

4 Laryngoscope, 131:E1821-E1829, 2021.

Free Flap Monitoring, Salvage, and Failure Timing: A Systematic Review

BACKGROUND

 Microsurgical free tissue transfer has become a reliable technique with success rates around 99% and around 5% requiring exploration for vascular compromise. Protocols for flap monitoring between plastic surgery units vary. We aimed to elucidate the time period when monitoring is crucial for flap salvage.

METHODS

 A systematic search of literature was performed in PubMed, Cochrane Library, Medline, and Scopus databases from 1966 to July 2018 according to Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines, identifying 3,844 studies with mention of free flap and monitoring or timing or salvage or compromise. Studies were screened for relevance according to predetermined inclusion criteria. Data was extracted from included studies relating to flap type, monitoring, timing and reason for failure, and success of salvage intervention.

RESULTS

 A total of 109 studies featuring 44,031 free flaps were included. A total of 2,549 (5.8%) flaps required return to theater for compromise; 926 (2.1%) were lost and 1,654 (3.7%) were salvaged. In the first 24 hours postoperatively 93.8% of explored flaps are successfully salvaged, by day 2: 83.33%, day 3: 12.1%, and beyond day 4: none were successful. Of the 355 flaps where the cause of failure was reported, 59.5% was venous, 27.9% was arterial, 2.3% was a combination of both, and 10.2% was hematoma or infection. The proportion of flap failures at various recipient sites was highest in the trunk/viscera (7%, 95% confidence interval [CI] 0.00, 0.36), followed by limbs (5%, 95% CI 0.02, 0.08), head and neck (3%, 95% CI 0.02, 0.04), and breast (<1%; 95% CI 0.00, 0.02).

CONCLUSION

 Close flap monitoring is of most value in the first 48 hours postoperatively, facilitating rapid detection of vascular compromise, early salvage, and better outcomes. The location of the flap has implications on its success and certain recipient sites may need particular attention to improve chances of success.

Four Lessons Learned from Complications in Head and Neck Microvascular Reconstructions and Prevention Strategies

Free flap reconstruction in the head and neck region is a complex field in which patient comorbidities, radiation therapy, tumor recurrence, and variability of clinical scenarios make some cases particularly challenging and prone to devastating complications. Despite low free flap failure rates, the impact of flap failure has enormous consequences for the patients.

METHODS

Acknowledging and predicting high risk intra- and postoperative situations and having planned strategies on how to deal with them can decrease their rate and improve the patient's reconstructive journey.

RESULTS

Herein, the authors present 4 examples of significant complications in complex microvascular head and neck cancer reconstruction, encountered for the last 10 years: compression and kinking of the vascular pedicle, lack of planning of external skin coverage in osteoradionecrosis, management of the vessel-depleted neck, and vascular donor site morbidity after fibula harvest.

CONCLUSION

The authors reflect on the causes and propose preventative strategies in each peri-operative stage.

Modified Clavien-Dindo Classification and Outcome Prediction in Free Flap Reconstruction among Patients with Head and Neck Cancer

Because of limitations caused by unique complications of free flap reconstruction, the Clavien–Dindo classification was modified to include grade “IIIc” for “partial or total free flap failure.” From 2013 to 2018, 116 patients who had undergone free flap reconstruction for head and neck cancer with grade III or higher postoperative complications were grouped using the “Modified” Clavien–Dindo classification. Alcoholism displayed significant predictive effects between grade IIIb and IIIc (72.7% vs. 50%, p = 0.028). Significant differences were observed between grade IIIb and IIIc in the duration of hospital stay (23.1 ± 10.1 vs. 28.6 ± 11.9 days, p = 0.015), duration of intensive care unit stay (6.0 ± 3.4 vs. 8.7 ± 4.3 days, p = 0.001), reoperation times during the current hospitalization (1.4 ± 0.8 vs. 2.0 ± 1.0 times, p < 0.001), and wound infection rate (29.9% vs. 62.5%, p = 0.002). The severity levels were significantly positively correlated with reoperation times during the current hospitalization (p < 0.001), ICU stay (p = 0.001), and hospital stay (p < 0.001). The modified Clavien–Dindo classification with grade IIIc describes the perioperative complications of head and neck free flap reconstruction to predict clinical outcomes based on severity.

Predicting risk factors that lead to free flap failure and vascular compromise: A single unit experience with 565 free tissue transfers

BACKGROUND

Even though the benefit of free tissue transfer is uncontested in complex reconstructive cases, vascular compromise and/or flap failure remain a challenge for the surgeon and identification of possible risk factors can aid in the preoperative planning. The aim of this study was to identify the individual risk factors leading to flap failure and/or vascular compromise in free tissue transfers in a single institution over a period of 10 years and to create an index predicting these problems, as well as finding predictors of other postoperative complications.

METHODS

Data from all the patients undergoing free tissue transfers between 2009 and 2018 were retrospectively analyzed (demographics, comorbidities, flap failure, vascular compromise, and other complications). The results from the univariate and multivariate analyses were used to create an index.

RESULTS

A predictability index with three classes (low, moderate, and high risk) was calculated for each patient, based on defect etiology and the presence of coronary heart disease, diabetes, smoking, peripheral arterial vascular disease, and arterial hypertension. A patient with moderate-risk index had 9.3 times higher chances of developing vascular compromise than those in the low-risk group, while a high-risk index had 18.6 higher odds (p=0.001). American Society of Anesthesiologists (ASA) classification was found to be a predictor of complications in free tissue transfer (p=0.001).

CONCLUSION

If patients at a high risk of vascular compromise could be identified preoperatively through this predictability index, patient counseling could be improved and the surgeon might adapt the reconstructive plan and choose an alternative reconstructive strategy.

The chicken or the egg? Relationship between venous congestion and hematoma in free flaps

BACKGROUND

Postoperative hematoma and venous congestion after free tissue transfer may occur independently or concurrently. We aimed to explore the association between these two events.

METHODS

All free flap reconstructions for head and neck (HN) and breast from a single institution between 2004 and 2014 were retrospectively reviewed for reoperation for venous congestion and/or hematoma.

RESULTS

There were 2985 free flap cases for HN reconstruction and 2345 cases for breast reconstruction. In HN, 100 patients developed a hematoma (3.4%) and 84 patients developed venous congestion (2.8%). The prevalence of hematoma was 17.8% and 2.9% in the presence and absence of congestion, respectively (p<0.001). Among the 15 patients who had both hematoma and venous congestion were separate events that occurred from 1 to 9 days apart in 8 patients. Hematoma caused the compression of the pedicle vein in 4 patients, while venous congestion possibly caused hematoma in 3 patients. In breast, 56 patients developed a hematoma (2.4%) and 64 patients developed venous congestion (2.7%). The prevalence of hematoma was 12.5% and 2.1% in the presence and absence of congestion, respectively (p<0.001). In the 8 patients who developed both, hematoma and congestion were separate events in 4 patients. Venous congestion caused hematoma in 3 patients, and hematoma caused venous congestion in 1 patient.

CONCLUSIONS

Although postoperative hematoma and venous congestion often present concurrently, most events are not causally associated. When related, however, venous congestion leading to hematoma is more common in breast reconstruction, while hematoma preceding venous congestion is more common in HN reconstruction.

Remote Ischemic Preconditioning in Microsurgical Head and Neck Reconstruction: A Randomized Controlled Trial

Background:

The free flap failure rate is 5% in head and neck microsurgical reconstruction, and ischemia–reperfusion injury is an important mechanism behind this failure rate. Remote ischemic preconditioning (RIPC) is a recent intervention targeting ischemia–reperfusion injury. The aim of the present study was to investigate if RIPC improved clinical outcomes in microsurgical reconstruction.

Methods:

Head and neck cancer patients undergoing tumor resection and microsurgical reconstruction were included in a randomized controlled trial. Patients were randomized (1:1) to RIPC or sham intervention administered intraoperatively just before transfer of the free flap. RIPC was administered by four 5-minute periods of upper extremity occlusion and reperfusion. Clinical data were prospectively collected in the perioperative period and at follow-up on postoperative days 30 and 90. Intention-to-treat analysis was performed.

Results:

Sixty patients were randomized to RIPC (n = 30) or sham intervention (n = 30). All patients received allocated intervention. No patients were lost to follow up. At 30-day follow-up, flap failure occurred in 7% of RIPC patients (n = 2) and 3% of sham patients (n = 1) with the relative risk and 95% confidence interval 2.0 [0.2;20.9], P = 1.0. The rate of pedicle thrombosis was 10% (n = 3) in both groups with relative risk 1.0 [0.2;4.6], P = 1.0. The flap failure rate did not change at 90-day follow-up.

Conclusions:

RIPC is safe and feasible but does not affect clinical outcomes in head and neck cancer patients undergoing microsurgical reconstruction.

Negative pressure-induced hyperemia, a new modality in the monitoring of skin paddle containing free flaps

BACKGROUND

In free tissue transfer, monitoring is paramount to timely detect vascular complications. Although various technical methods have been introduced, clinical flap monitoring and, particularly, capillary refill test (CRT) remain the gold standard. In pale flaps, CRT is challenging as it relies on the color difference between blanched and perfused skin. We proposed a new method of negative pressure-induced hyperemia (NPIH) using handheld electrical negative pressure devices to improve flap monitoring.

METHODS

Forty consecutive patients who received 42 free flaps in our institution were included in the study. Postoperatively, digital photographs were taken during CRT and NPIH, and the color difference (ΔE) was calculated based on the images. Additionally, three surgeons and three nurses evaluated the ease of assessment of capillary refill and NPIH on each flap using five grades.

RESULTS

NPIH yielded a significantly higher color difference than CRT with a mean ΔE of 10.3 ± 3.3 versus 6.8 ± 4.2. Although for CRT, ΔE of 14 flaps was <5 and of seven flaps <3, all flaps had a ΔE of >5 for NPIH. Subjectively, both surgeons and nurses found NPIH in all flaps to be easier to assess with a mean score of 1.1 ± 0.3 versus 1.8 ± 1.1 for CRT. However, some flaps were found to be challenging or not assessable by CRT.

CONCLUSION

NPIH represents a safe, easily applicable, and cheap addition to the established clinical and technical examination methods and may offer advantages over conventional CRT in detecting arterial complications in pale flaps.

Ischemia-reperfusion injury in a rat microvascular skin free flap model: A histological, genetic, and blood flow study

Ischemia reperfusion injury is associated with tissue damage and inflammation, and is one of the main factors causing flap failure in reconstructive microsurgery. Although ischemia-reperfusion (I/R) injury is a well-studied aspect of flap survival, its biological mechanisms remain to be elucidated. To better understand the biological processes of ischemia reperfusion injury, and to develop further therapeutic strategies, the main objective of this study was to identify the gene expression pattern and histological changes in an I/R injury animal model. Fourteen rats (n = 7/group) were randomly divided into control or ischemia-reperfusion group (8 hours of ischemia). Microsurgical anastomoses were objectively assessed using transit-time-ultrasound technology. Seven days after surgery, flap survival was evaluated and tissue samples were harvested for anatomopathological and gene-expression analyses.The I/R injury reduced the survival of free flaps and histological analyses revealed a subcutaneous edema together with an inflammatory infiltrate. Interestingly, the Arginase 1 expression level as well as the ratio of Arginase 1/Nitric oxide synthase 2 showed a significant increase in the I/R group. In summary, here we describe a well-characterized I/R animal model that may serve to evaluate therapeutic agents under reproducible and controlled conditions. Moreover, this model could be especially useful for the evaluation of arginase inhibitors and different compounds of potential interest in reconstructive microsurgery.

Fibula Free Flap in Head and Neck Reconstruction: Identifying Risk Factors for Flap Failure and Analysis of Postoperative Complications in a Low Volume Setting

The fibula free flap (FFF) has been a workhorse in maxillofacial reconstruction. High success rates of this technique are reported. However, identifying risk factors for flap failure and analyzing complications can open the way to better patient care. A retrospective analysis was conducted of all FFFs performed over a 20-year period at a low-volume single tertiary center to identify risk factors and postoperative complications. A total of 129 FFFs were included (122 mandible, 7 maxilla). Complete flap failure occurred in 12.4% and partial flap failure in 7.8% of patients. A significant relation was found between younger age and flap failure, and most failures were associated with venous thrombosis. In-hospital surgical complications occurred in 60.5%, in-hospital medical complications in 49.6%, and out-of-hospital complications in 77.5% of patients. The in-hospital reintervention rate was 27.1%, and including salvaged flaps, flap survival rate was 87.6%. Osteomyocutaneous FFF failure (complete 12.4%; partial 7.8%) is an important clinical reality in a low-volume head and neck reconstruction center resulting in an in-hospital reintervention rate of 27.1%. Postoperative complications are frequent, both surgical and out-hospital complications. These results provide a better understanding of the limitations of the FFF in a low-volume center and can be used to optimize care in this kind of setting.

Characteristics and Management of Free Flap Compromise Following Internal Jugular Venous Thrombosis

PURPOSE

Free flap compromise after internal jugular venous thrombosis (IJVT) occurs fairly infrequently in oral and maxillofacial rehabilitation and reconstruction but could seriously affect the patient's postoperative recovery. The aim of this study was to analyze and discuss the characteristics and management of such flap compromise.

PATIENTS AND METHODS

The authors performed a retrospective case series of 13 patients who underwent reconstruction of oral and maxillofacial defects with anterolateral thigh flaps and developed flap compromise from IJVT from July 2014 through December 2016 at the Second Xiangya Hospital of Central South University (Changsha, China). The clinical features of flap compromise are described, and the precautions and improvement measures are reported.

RESULTS

All 13 patients were men with an average age of 50.3 years. Flap compromise caused by IJVT occurred on postoperative days 3 to 7, of which 2 flaps were salvaged (15.4%) and 11 flaps failed completely after immediate urgent re-exploration. Four patients presented with orocutaneous fistula after salvage surgery that healed well after a period of wound dressing.

CONCLUSIONS

Because of the late occurrence and low salvage rate of flap compromise caused by IJVT, intensive flap monitoring after reconstruction surgery is necessary for patients with free flap transfer.

Video Tutorial for Clinical Flap-Monitoring in Plastic Surgery

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