What makes a good flap go bad?: A critical analysis of the literature of intraoperative factors related to free flap failure

Adverse events associated with anastomotic coupling devices in microvascular reconstruction

OBJECTIVE

In light of the recent US Food and Drug Administration (FDA) Class 2 safety recall notice for anastomotic coupling devices, it is important to understand related adverse events. The aim of this study was to characterize adverse events in anastomotic coupling devices for microvascular reconstruction.

METHODS

A retrospective cross-sectional analysis using the 2011 to 2021 US FDA Manufacturer and User Facility Device Experience (MAUDE) database. All reports of adverse events involving anastomotic coupling devices were retrieved from the MAUDE database. Descriptive statistics were used to analyze categorized events.

RESULTS

There were a total of 293 documented adverse events related to anastomotic coupling devices. These adverse events resulted in 91 (31.1 %) patient injuries and 239 (81.6 %) device malfunctions. The most frequent patient problems were thrombosis/hematoma (n = 38; 41.8 %), unspecified injury (n = 31; 34.1 %), and failure to anastomose (n = 13; 14.3 %). Free flap necrosis was reported in 42 % of thrombosis/hematoma cases (n = 16). The most common malfunctions were devices operating differently than expected (n = 74; 31.0 %), connection problems (n = 41; 17.2 %), and twisted/bent material (n = 19; 7.9 %). There was no significant trend in the number of adverse events over the study period (p > 0.05).

CONCLUSIONS

Adverse events from anastomotic coupling devices represent an important and modifiable factor in free tissue failure. Adverse events are predominately related to devices operating differently than expected and may result in vascular compromise of the free flap. Reconstructive surgeons should be cognizant of defective anastomotic coupling devices and be prepared to utilize traditional hand-sewn anastomosis.

The Impact of Intraoperative Vasopressor Use and Fluid Status on Flap Survival in Traumatic Lower Extremity Reconstruction

BACKGROUND

 Historically, the use of intraoperative vasopressors during free flap lower extremity (LE) reconstruction has been proposed to adversely affect flap survival due to concerns about compromising flap perfusion. This study aims to analyze the impact of intraoperative vasopressor use and fluid administration on postoperative outcomes in patients undergoing traumatic LE reconstruction.

METHODS

 Patients who underwent LE free flap reconstruction between 2015 and 2023 at a Level I Trauma Center were retrospectively reviewed. Statistical analysis was conducted to evaluate the association between vasopressor use and intraoperative fluids with partial/complete flap necrosis, as well as the differential effect of vasopressor use on flap outcomes based on varying fluid levels.

RESULTS

 A total of 105 LE flaps were performed over 8 years. Vasopressors were administered intraoperatively to 19 (18.0%) cases. Overall flap survival and limb salvage rates were 97.1 and 93.3%, respectively. Intraoperative vasopressor use decreased the overall risk of postoperative flap necrosis (OR 0.00005, 95% CI [9.11 × 10-9-0.285], p = 0.025), while a lower net fluid balance increased the risk of this outcome (OR 0.9985, 95% CI [0.9975-0.9996], p = 0.007). Further interaction analysis revealed that vasopressor use increased the risk of flap necrosis in settings with a higher net fluid balance (OR 1.0032, 95% CI [1.0008-1.0056], p-interaction =0.010).

CONCLUSION

 This study demonstrated that intraoperative vasopressor use and adequate fluid status may be beneficial in improving flap outcomes in LE reconstruction. Vasopressor use with adequate fluid management can optimize hemodynamic stability when necessary during traumatic LE microvascular reconstruction without concern for increased risk of flap ischemia.

A Pilot Study: Free Flap Atrophy in Tongue Reconstruction Using 3D Volumetric Analysis

OBJECTIVE

To identify factors influencing volume change in non-osseous oral free flap reconstruction using postoperative cross-sectional imaging and 3-dimensional segmentation of the free flap's muscular and adipose tissue content.

METHODS

Oral tongue free flap reconstruction cases (2014-2019) were reviewed with inclusion of patients with 3 postoperative, cross-sectional imaging studies with 1 within 6 months, 1 within 1 year, and 1 that spanned 2 years post-reconstruction. Exclusion criteria included recurrence, significant dental artifact, bony reconstruction, and flap failure. Demographics, risk factors, and surgical/clinical treatments were identified. Flap volumes were measured using Materialise MIMICS.

RESULTS

Twenty-two patients met strict inclusion criteria. Four flaps were anterolateral thighs and 18 radial forearms. Median percent volume loss greater than 2 years post-reconstruction was 53.2% overall, 58.1% for radial forearms, and 45.4% for ALTs (21.4% for adipose tissue and 57.4% for muscular tissue). Univariate analysis revealed glossectomy amount was associated with percent volume loss (P = .0417). Each successive postoperative month, the flap decreased by 1.54% (P < .0001). Checking for the interaction effect, the percent of flap loss across time was different for glossectomy amount (P = .0093), obesity status (P = .0431), and base of tongue involvement (P = .0472).

CONCLUSION

Glossectomy type, and thus flap size, is a positive predictor for flap atrophy. Obesity and base of tongue involvement are negative predictors for flap atrophy. The amount of tissue loss may differ from classical teachings with median atrophy 53.2% greater than 2 years post-reconstruction.

The Perfect Timing-Immediate versus Delayed Microvascular Reconstruction of the Mandible

In this retrospective study, the clinical and economic implications of microvascular reconstruction of the mandible were assessed, comparing immediate versus delayed surgical approaches. Utilizing data from two German university departments for oral and maxillofacial surgery, the study included patients who underwent mandibular reconstruction following continuity resection. The data assessed included demographic information, reconstruction details, medical history, dental rehabilitation status, and flap survival rates. In total, 177 cases (131 male and 46 females; mean age: 59 years) of bony free flap reconstruction (72 immediate and 105 delayed) were included. Most patients received adjuvant treatment (81% with radiotherapy and 51% combined radiochemotherapy), primarily for tumor resection. Flap survival was not significantly influenced by the timing of reconstruction, radiotherapy status, or the mean interval (14.5 months) between resection and reconstruction. However, immediate reconstruction had consumed significantly fewer resources. The rate of implant-supported masticatory rehabilitation was only 18% overall. This study suggests that immediate jaw reconstruction is economically advantageous without impacting flap survival rates. It emphasizes patient welfare as paramount over financial aspects in clinical decisions. Furthermore, this study highlights the need for improved pathways for masticatory rehabilitation, as evidenced by only 18% of patients with implant-supported dentures, to enhance quality of life and social integration.

The Role of Intraoperative and Early Postoperative Blood Pressure Variations, Fluid Balance and Inotropics in Fibula Free Flap Head and Neck Reconstruction: A Retrospective Analysis

BACKGROUND

In head and neck reconstructive surgery, postoperative complications are a well-known concern.

METHODS

We examined 46 patients who underwent ablative surgery and received fibula free flap reconstruction. The main focus was to assess the influence of intraoperative blood pressure fluctuations and the administration of inotropic drugs on complications, either related to the flap or systemic, serving as the primary endpoint.

RESULTS

Utilizing logistic regression models, we identified that intraoperative mean arterial blood pressure (MAP) drops did not correlate with the occurrence of either flap-related complications (MAP < 70, p = 0.79; MAP < 65, p = 0.865; MAP < 60, p = 0.803; MAP < 55, p = 0.937) or systemic medical complications (MAP < 70, p = 0.559; MAP < 65, p = 0.396; MAP < 60, p = 0.211; MAP < 55, p = 0.936). The occurrence of flap-related complications significantly increased if a higher dosage of dobutamine was administered (median 27.5 (IQR 0-47.5) vs. 62 (38-109) mg, p = 0.019) but not if norepinephrine was administered (p = 0.493). This correlation was especially noticeable given the uptick in complications associated with fluid overload (3692 (3101-4388) vs. 4859 (3555-6216) mL, p = 0.026).

CONCLUSION

Intraoperative and immediate postoperative blood pressure fluctuations are common but are not directly associated with flap-related complications; however, dobutamine application as well as fluid overload may impact flap-specific complications.

Heparin regimes in head and neck cancer flap surgery: A retrospective cohort study of free flap complications graded by Clavien-Dindo

The purpose of the current study was to compare two different antithrombotic protocols for free flap reconstruction in head and neck squamous cell carcinoma (HNSCC) patients. Postoperative complications were graded using the Clavien-Dindo (CD) classification and compared between the two groups: the low-molecular-weight heparin (LMWH) group (n = 57) and the unfractionated heparin (UFH) group (n = 59). Patients with HNSCC from January 2010 to January 2022 were included. A total of 116 patients with a mean age of 60.46 years (range 43-83 years) were included in this study. In all, 81 were male (69.8%), and 35 were female (30.2%). Most patients (48.3%) had only grade 1 or 2 complications. CD grades (1-5) were similar between the two groups. Flap loss occurred in 2 patients (1.7%) in the LMWH group (p = 239). Prognostic factors of flap loss were high BMI, hypertension, high T stage, and high N stage. No differences were found between the groups in regard to age, sex, operating times, flap source, recipient vessels and overall complications. The results of this study demonstrate that UFH was as safe and effective as LMWH regarding postoperative complications. Free flap surgery is safe and effective for head and neck reconstruction.

Enhanced recovery after surgery, current, and future considerations in head and neck cancer

Objectives

Review of the current and relevant literature to develop a list of evidence-based recommendations that can be implemented in head and neck surgical practices. To provide rationale for the multiple aspects of comprehensive care for head and neck surgical patients. To improve postsurgical outcomes for head and neck surgical patients.

Methods

Extensive review of the medical literature was performed and relevant studies in both the head and neck surgery and other surgical specialties were considered for inclusion.

Results

A total of 18 aspects of perioperative care were included in this review. The literature search included 276 publications considered to be the most relevant and up to date evidence. Each topic is concluded with recommendation grade and quality of evidence for the recommendation.

Conclusion

Since it's conception, enhanced recovery after surgery (ERAS) protocols have continued to push for comprehensive and evidence based postsurgical care to improve patient outcomes. Head and neck oncology is one of the newest fields to develop a protocol. Due to the complexity of this patient population and their postsurgical needs, a multidisciplinary approach is needed to facilitate recovery while minimizing complications. Current and future advances in head and neck cancer research will serve to strengthen and add new principles to a comprehensive ERAS protocol.

Level of Evidence

2a.

Team Consistency in Reducing Operative Time in Head and Neck Surgery with Microvascular Free Flap Reconstruction

OBJECTIVE(S)

To evaluate the impact of consistent surgical teams on procedure duration in head and neck free tissue transfer, and to evaluate the length of stay and readmission rates with consistent teams.

METHODS

A retrospective chart review of head and neck microvascular reconstruction by a single surgeon between August 2017 and November 2021 was performed. Procedure duration, wound complications, length of stay, and 30-day readmissions were analyzed. One circulating nurse (CN) and surgical technologist (ST) were considered "consistent" due to their prior work with the primary surgeon. All others were considered "ad hoc." Teams were "Consistent CN + ST," "Consistent ST," "Consistent CN," or "Ad hoc." Procedure duration between groups was compared via analysis of variance. Multivariate linear regression was performed to predict procedure duration.

RESULTS

A total of 135 patients were included. Age, sex, and American Society of Anesthesiologists status did not significantly differ across groups (p = 0.963; p = 0.467; p = 0.908, respectively). The mean procedure duration was 339.3 min and differed significantly across all groups (p = 0.006, Cohen d = 0.32). Compared to the Ad hoc group, consistent teams demonstrated significant reductions in mean procedure duration (Consistent CN + ST: 58.4 min, p = 0.001, Cohen d = 0.67; Consistent ST: 51.6 min, p = 0.013, Cohen d = 0.61; Consistent CN: 44.5 min, p = 0.031, Cohen d = 0.52). Controlling for other factors, the ad hoc team predicted increased procedure duration on multivariate analysis ( β 57.38, 19.92-94.85, p < 0.003). Wound complications, length of stay, and readmission rates did not differ significantly across groups (p = 0.940; p = 0.174; p = 0.935, respectively).

CONCLUSION

Consistent CN and ST improve operative efficiency in head and neck-free tissue transfer. Future studies may evaluate the impact of team consistency on complications, physician burnout, and health systems costs.

LEVEL OF EVIDENCE

3 Laryngoscope, 133:2154-2159, 2023.

Evidence based recommendations for perioperative vasopressor use and fluid resuscitation in microsurgery

Blood pressure regulation is critical in patients undergoing microsurgical free tissue transfer; however, guidelines for addressing and preventing perioperative hypotension remain highly debated, with two current thought paradigms: (1) intravenous fluid administration with a balanced salt solution (e.g., lactate ringer and normal saline) and/or colloid (e.g., albumin) and (2) vasoactive pharmacological support with vasopressors (e.g., dobutamine, norepinephrine, epinephrine), with fluid administration being the preferred conventional approach. Here, we review the most up to date available literature and summarize currents perspectives and practices for fluid resuscitation and vasopressor use, while offering evidence-based guidelines to each.

Effect of sevoflurane-remifentanil and propofol-remifentanil anesthesia on glycocalyx shedding during deep inferior epigastric perforator flap breast reconstruction: a prospective randomized, controlled trial

BACKGROUND

The endothelial glycocalyx (EG) is an important structure that regulates vascular homeostasis. Deep inferior epigastric perforator (DIEP) flap is expected to cause substantial EG breakdown owing to the long procedural duration and ischemia- reperfusion injury. This prospective, randomized, controlled study aimed to compare syndecan-1 levels during sevoflurane-remifentanil and propofol-remifentanil anesthesia in patients who underwent DIEP flap breast reconstruction.

METHODS

Fifty-one patients were randomized to either sevoflurane (n = 26) or propofol (n = 25) groups. Anesthesia was maintained with remifentanil in combination with either sevoflurane or propofol. The primary endpoint was the concentration of serum syndecan-1 measured at 1 h after surgery.

RESULTS

Fifty patients (98.0%) completed the study. Patients in the propofol group had significantly lower levels of syndecan-1 than patients in the sevoflurane group at 1 h after operation (23.8 ± 1.6 vs. 30.9 ± 1.7 ng/ml, respectively; Bonferroni corrected P = 0.012). There were no significant differences between groups in postoperative complications. The postoperative hospital stay was 8.4 ± 2.5 days in the sevoflurane group and 7.4 ± 1.0 days in the propofol group (P = 0.077).

CONCLUSIONS

Propofol-remifentanil anesthesia resulted in lesser increases in syndecan-1 levels compared to increases with sevoflurane-remifentanil anesthesia in patients who underwent DIEP flap reconstruction. Our results suggest that propofol-remifentanil anesthesia shows protective effects against EG damage during DIEP flap breast reconstruction in contrast to sevoflurane-remifentanil anesthesia.

Preoperative anemia: Predictor of free flap reconstruction complications in head and neck cancer

Free flap reconstruction has been the mainstay among reconstruction surgeries for head and neck cancer. Intraoperative and postoperative hemoglobin (Hb) levels were both possible risk factors of flap failure and had been discussed widely. However, few investigations of preoperative Hb were seen in the previous study with its effect to flap condition remain uncertain and no conclusions in the literature. Patients who underwent free flap reconstruction after head and neck surgery in our institution between May 2014 and May 2019 were enrolled. The postoperative flap condition was observed carefully, and re-exploration was performed if necessary. We then retrospectively collected patient data with several intraoperative and postoperative indices. A total of 598 patients were enrolled in our study. The total major flap complication rate was 10.6%, with an overall success rate of 89.4%. They were predominantly male (95%), and most of them underwent free flap reconstruction for the first time (91%). A total of 81 (13%) patients received radiotherapy before reconstruction. Among all factors, the preoperative Hb level and free flap type showed significance in univariate and multivariate analyses. A previous history of radiotherapy, body mass index, nutrition status, or poorly controlled diabetes mellitus showed no significant results in either univariate or multivariate analysis. Our study showed that a lower preoperative Hb level affects free flap survival. Meanwhile, preoperative radiotherapy history has no significant influence in either univariate or multivariate analysis.

Safety and effectiveness of regional anesthesia compared with anesthetic techniques not using regional anesthesia on outcomes after free tissue flap surgery: a systematic review protocol

OBJECTIVE

This systematic review will aim to evaluate the evidence on the effectiveness of regional anesthesia, when compared with general anesthesia alone, on the outcomes of free flap surgeries.

INTRODUCTION

Free flap procedures involve complete separation of a flap of tissue from its native vascular bed, followed by reimplantation to a recipient site on the body. Optimal perfusion and successful neovascularization are crucial to survival of the grafted flap. Currently, no best-practice recommendations exist regarding the use of regional anesthesia in free flap surgeries. Regional anesthesia techniques have the potential to alter blood flow and neuroendocrine responses to surgical stress, which may impact perfusion and survival of free flap grafts. This potential for augmentation or hindrance of flap perfusion may have a significant impact on patient outcomes, thus meriting systematic review.

INCLUSION CRITERIA

The review will include both experimental and observational (analytical only) study designs that examine the vascular outcomes of regional anesthesia compared with general anesthesia alone in free flap surgery.

METHODS

The databases to be searched include PubMed, CINAHL, Cochrane Central Register of Controlled Trials (CENTRAL), Web of Science Core Collection, Embase, and gray literature sources. Identified studies will be independently assessed by two reviewers utilizing JBI critical appraisal tools. Data will be extracted using a standardized data matrix. Certainty of findings will be conducted using the Grading of Recommendations Assessment, Development and Evaluation approach. Narrative synthesis will be compiled and meta-analysis completed, where possible.

SYSTEMATIC REVIEW REGISTRATION NUMBER

PROSPERO CRD42021283584.

Impact of perioperative vasopressors on lower extremity free flap reconstruction

PURPOSE

Free tissue transfer is a treatment option for soft tissue defects of the lower extremity. For a successful outcome, it is necessary to evaluate the vessel condition and blood flow patency. The administration of a vasopressor could impact the survival rate of free tissue transfer; however, there is a lack of studies on vasopressor use and lower extremity reconstruction. This study aimed to investigate the relationship between the use of a vasopressor and outcomes of free tissue transfer in lower extremity reconstruction.

METHODS

This retrospective, observational study was conducted between March 2010 and February 2019. Data were divided into intraoperative and postoperative variables according to the administration time. Data on patient demographics, risk factors, details of reconstruction, flap outcomes, and duration of intensive care unit (ICU) stay were obtained. Binary logistic regression models were computed to determine the association between flap outcome and vasopressor administration.

RESULTS

Of the 338 patients, 186 were administered a vasopressor. Intraoperative and postoperative vasopressor use was not related to the overall complication rate (odds ratio, 1.547; 95% confidence interval, 0.830-2.882; p = .169). Low-intraoperative levels of hemoglobin were associated with the overall complication rate. Postoperative vasopressor administration was associated with prolonged ICU stay.

CONCLUSION

Our results showed that the intraoperative and postoperative use of vasopressors was not significantly associated with the success rate of free flaps. Future studies investigating the relationship between the dose, type, and duration of vasopressors and the complication rate following free tissue transfer are warranted.

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.

Moving to a more restrictive transfusion protocol: Outcomes in head and neck free flap surgery

PURPOSE

To determine if a more restrictive transfusion protocol results in increased rates of adverse flap outcomes in patients undergoing free tissue transfer.

MATERIALS AND METHODS

Mixed retrospective and prospective cohort study. Patients who underwent surgery before the protocol change were collected retrospectively. Patients who underwent surgery after the protocol change were collected prospectively.

RESULTS

Of the 460 patients who underwent free tissue transfer, 116 patients in the pre-change cohort (N = 211) underwent transfusion (54.98%) and 78 in the post-change cohort(N = 249) (31.33%) (p < 0.001). The mean number of units transfused was 1.55 + 2.00 in the pre-change cohort, and 0.78 + 1.51 in the post-change cohort (p < 0.001). When separated temporally, the pre-change cohort received significantly more blood transfusions than the post-change cohort in the operating room (33.65% vs 18.07%) (p < 0.01), within 72 h of surgery (35.55% vs 15.66%) (p < 0.001), and after 72 h after surgery to discharge (16.59% vs 8.03%) (p = 0.018017). The rate of flap failure was 6.70% in the pre-change cohort, and 5.31% in the post-change cohort (p = 0.67). In a logistic regression model controlling for potential confounders, transfusion protocol was not significantly associated with flap failure (OR = 1.1080, 95% CI: 0.48-2.54). There were no significant differences between cohorts for medical morbidity, ICU transfer, or death.

CONCLUSION

Our data support the conclusion that patients undergoing free tissue transfer to the head and neck can be transfused following the same protocols as other patients, without increasing the rate of flap failure or other morbidities.

LEVEL OF EVIDENCE

3 (mixed retrospective, prospective cohort study).

Association between hypertension requiring medication and 30-day outcomes in head and neck microvascular surgery

BACKGROUND

Hypertension has been shown to be both a protective factor and a risk factor for complications in head and neck reconstructive surgery.

METHODS

Retrospective analysis of microvascular free tissue transfer patients using the National Surgical Quality Improvement Program database.

RESULTS

Hypertensive patients (n = 1598; 46.9%) had a significantly higher rate of complications, including pneumonia (p < 0.001), myocardial infarction (p = 0.003), and intra/post-operative transfusion (p < 0.001). In a multivariable model, hypertension was associated with returning to the operating room (OR = 1.45 [95% CI 1.20, 1.76], p < 0.001), post-operative medical complications (OR = 1.53 [95% CI 1.24, 1.90], p < 0.001), and surgical complications (OR = 1.17 [95% CI 1.00, 1.37], p = 0.047). However, no difference in 30-day readmission was found (p > 0.05).

CONCLUSIONS

Hypertension is a modifiable risk factor for post-operative complications in head and neck free tissue transfer, in which prospective studies are required to establish causation. This study may serve as an impetus for proactive recommendations to manage hypertension before undergoing head and neck microvascular surgery.

Association of Continuous Intraoperative Vasopressor Use With Reoperation Rates in Head and Neck Free-Flap Reconstruction

Importance

Continuous vasopressor use in free-flap reconstruction is a point of contention among microvascular surgeons despite data demonstrating safety.

Objective

To investigate the association between continuous vasopressor use and the incidence of reoperation in the early postoperative period.

Design, Setting, and Participants

In this cohort study, a retrospective medical record review was conducted of patients who underwent head and neck free-flap reconstructions between May 1, 2014, and October 31, 2019, in an academic tertiary care center. All patients undergoing free-flap reconstruction for head and neck defects were included.

Exposures

Continuous intraoperative vasopressors.

Main Outcomes and Measures

Patient medical records were queried for demographic variables; intraoperative use of vasopressors; vasopressor type, duration, and infusion rate; reoperation within the first 5 postoperative days; and reason for reoperation.

Results

Four hundred forty-nine consecutive free-flap reconstructions were performed on 426 patients. The mean age was 62 years (IQR, 55.7-71.1); 293 patients were men (65.3%), 380 were White (84.6%), 55 were Black (12.2%), and 14 were of other race or ethnicity (3.1%). A total of 174 patients received a continuous vasopressor during their reconstruction. Twenty-three reoperations occurred within 5 days postoperatively, 8 of which included vasopressors during initial intervention. Vasopressor type had no association with reoperation (4.5% vs 5.5% [8/174 vs 15/275, respectively] for patients who received vasopressors vs those who did not) (dobutamine odds ratio [OR], 1.02 [95% CI, 0.21-2.91]; dopamine OR, 1.48 [95% CI, 0.33-4.26]). No difference was seen in the duration (dobutamine OR, 1.50 [95% CI, 0.78-2.90]; dopamine OR, 0.87 [95% CI, 0.59-1.28]) or infusion rate (dobutamine OR, 1.50 [95% CI, 0.99-1.02]; dopamine OR, 1.00 [95% CI, 0.99-1.01]) of vasopressors between patients who underwent reoperation and those who did not. Analysis after the exclusion of reasons for reoperation that did not represent possible microvascular anastomosis failure (eg, Doppler malfunction, donor site complications) showed no increased propensity for reoperation (OR, 1.18; 95% CI, 0.27-3.9).

Conclusions and Relevance

In this cohort study, use of vasopressors for extensive periods intraoperatively during free-tissue transfer appeared to have no association with the rate of reoperation within 5 days of intervention, regardless of agent used, simultaneous use of agents, type of free-flap operation performed, or reason for reoperation. This study adds to the body of literature supporting the judicious use of vasopressors in patients requiring intraoperative pharmacological pressure support during free-flap reconstruction.

Expert Consensus Statement on the Perioperative Management of Adult Patients Undergoing Head and Neck Surgery and Free Tissue Reconstruction From the Society for Head and Neck Anesthesia

The perioperative care of adult patients undergoing free tissue transfer during head and neck surgical (microvascular) reconstruction is inconsistent across practitioners and institutions. The executive board of the Society for Head and Neck Anesthesia (SHANA) nominated specialized anesthesiologists and head and neck surgeons to an expert group, to develop expert consensus statements. The group conducted an extensive review of the literature to identify evidence and gaps and to prioritize quality improvement opportunities. This report of expert consensus statements aims to improve and standardize perioperative care in this setting. The Modified Delphi method was used to evaluate the degree of agreement with draft consensus statements. Additional discussion and collaboration was performed via video conference and electronic communication to refine expert opinions and to achieve consensus on key statements. Thirty-one statements were initially formulated, 14 statements met criteria for consensus, 9 were near consensus, and 8 did not reach criteria for consensus. The expert statements reaching consensus described considerations for preoperative assessment and optimization, airway management, perioperative monitoring, fluid management, blood management, tracheal extubation, and postoperative care. This group also examined the role for vasopressors, communication, and other quality improvement efforts. This report provides the priorities and perspectives of a group of clinical experts to help guide perioperative care and provides actionable guidance for and opportunities for improvement in the care of patients undergoing free tissue transfer for head and neck reconstruction. The lack of consensus for some areas likely reflects differing clinical experiences and a limited available evidence base.

Outcomes in Head and Neck Free Flap Reconstruction Among Patients With a History of Venous Thromboembolism

OBJECTIVE

To investigate if a history of venous thromboembolism (VTE) is a risk factor for complications in head and neck free flap surgery by assessing outcomes among patients with a history of deep vein thrombosis (DVT) and/or pulmonary embolism (PE).

STUDY DESIGN

Retrospective cohort study.

SETTING

Single tertiary care center.

METHODS

All patients undergoing head and neck free flap reconstruction at our institution between September 1, 2006, and April 2, 2020, were assessed for inclusion. Patients with and without a history of DVT or PE preoperatively were identified and grouped for comparison. Groups were compared for demographics, comorbidities, and 30-day complications. Significance was assessed with chi-square and binary logistic regression analyses.

RESULTS

Of the 1061 patients meeting inclusion criteria, 40 (3.8%) had a history of VTE. These patients were significantly older (mean [SD], years: 67.8 [11.7] vs 63.0 [14.1], P = .038) and significantly more likely to have history of chemotherapy (35.0% vs 18.7%, P = .010) and stroke (27.5% vs 4.5%, P < .001). After accounting for patient characteristics via binary logistic regression, VTE was independently associated with an increased risk for postoperative thrombosis of the free flap pedicle (odds ratio [95% CI] = 3.65 [1.12-11.90], P = .032) and reoperation (2.45 [1.25-4.80], P = .009). Patients with history of PE had a significantly increased risk for flap failure (7.70 [1.77-33.52], P = .007). Prior VTE was not independently associated with an increased risk for medical complications or readmission.

CONCLUSION

Patients with a history of VTE may be at an increased risk for free flap compromise secondary to postoperative pedicle thrombosis. This risk should be considered in preoperative workup and postoperative monitoring.

Clinical consequences of head and neck free-flap reconstructions in the DM population

Diabetes mellitus (DM) is a common comorbidity and risk factor for postoperative complications in head and neck (H&N) microsurgical reconstructions. Our study focused on the association between DM and individual complications regarding both surgical and medical aspects. A meta-analysis of English-language articles comparing a series of complications between DM and non-DM H&N free-flap recipients was performed by comprehensive meta-analysis (CMA). Twenty-seven articles presented 14,233 H&N free-flap reconstructions, and a subset of 2329 analyses including diabetic cases was included for final analysis. Total postoperative (RR = 1.194, p < 0.001; OR = 1.506, p = 0.030) and surgical (RR = 1.550, p = 0.001; OR = 3.362, p < 0.001) complications were increased in DM subjects. Free-flap failure/necrosis (RR = 1.577, p = 0.001; OR = 1.999, p = 0.001) and surgical site infections (OR = 2.414, p < 0.001) were also increased in diabetic recipients. However, return to the operating room, dehiscence, fistulas, plate exposures, readmissions, and mortalities were not increased in DM patients. DM increased various complications in H&N free-flap reconstructions. Surgical indications should be cautiously evaluated, and aggressive treatments should be implemented for high-risk recipients.

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.

Combined (endo-)vascular intervention and microsurgical lower extremity free flap reconstruction-A propensity score matching analysis in 5386 ACS-NSQIP patients

BACKGROUND

Compromised lower limb perfusion due to vascular changes such as peripheral artery disease impedes wound healing and may lead to large-scale tissue defects and lower limb amputation. In such patients with defects and compromised or lacking recipient vessels, combined vascular reconstruction with free flap transfer is an option for lower extremity salvage.

METHODS

By using the American College of Surgeons National Surgical Quality Improvement Program (ACS-NSQIP) database (2005-2018), we analyzed two patient cohorts undergoing (A) free flap lower limb reconstruction (LXTR) only and (B) combined (endo-)vascular reconstruction (vascLXTR). The preoperative variables assessed included demographic data and comorbidities, including smoking, diabetes mellitus, preoperative steroid use, and American Society of Anesthesiology (ASA) Physical Status Classification. Using a neighbor matching algorithm, we performed a 1:1 propensity score matching of 615 LXTR patients and 615 vascLXTR patients. Bivariate analysis for postoperative surgical and medical complications was performed for outcomes in the propensity-matched cohort.

RESULTS

We identified 5386 patients who underwent microsurgical free flap reconstruction of the lower extremity. A total of 632 patients underwent a combined (endo-)vascular intervention and lower extremity free flap reconstruction. Diabetes and smoking were more prevalent in this group, with 206 patients having diabetes (32.6%) and 311 being smokers (49.2%). More patients returned to the operating room in the cohort that underwent a combined vascular intervention (24.4% versus 9.9%; p<0.0001). The 30-day mortality for patients undergoing a combined vascular procedure was 3.5%, compared with 1.3% with free tissue transfer only (p<0.0001).

CONCLUSION

Despite the risks associated, the combined intervention decreases the very high mortality associated with limb amputation in severely sick patient populations. Careful preoperative assessment of modifiable risk factors may reduce complication rates while allowing limb salvage.

Efficiency of microvascular free flap reconstructive surgery: An observational study

OBJECTIVE

We aimed to assess operative workflow and efficiency in microvascular free flaps via a direct observational study based on Lean principles of quality improvement (QI).

METHODS

Observers monitored the workflow of twenty-three free flaps. Pre-operative preparation and surgical duration was recorded with supplemental data provided from our institution's surgical tracking database. Traffic patterns of operating room (OR) staff were documented as "entries" and "exits" from the OR and classified by role and the reason that the entry or exit was required. Patient data was obtained via chart review.

RESULTS

The mean surgical time was 9.0 h. Approximately 20% of OR time was dedicated to the pre-incision process, averaging 1.6 h per case. One third of entries and exits occurred during this period. In total, 180.2 surgical hours were observed during which 6215 "entries" and "exits" occurred. The mean number of entries and exits per case was 270; the most common reasons were supplies and communication. No association was observed between elapsed surgical time or total number of entries and exits with post-operative infection rates.

CONCLUSION

Comprehensive observational workflow studies of free flaps are challenging to execute due to lengthy procedure times. At our high-volume institution, a significant portion of OR time is devoted to the pre-incision period, largely due to inadequate supply availability and pre-operative communication. These findings will serve as a foundation for QI interventions at our institution, while our observational model provides a broadly applicable framework for assessing surgical efficiency.

Factors impacting successful salvage of the failing free flap

BACKGROUND

Understanding factors impacting successful salvage of a compromised free flap.

METHODS

Multi-institutional review of free flap reconstructions for head and neck defects (n = 1764).

RESULTS

Free flap compromise rate: 9% (n = 162); 46% salvaged (n = 74). Higher salvage rates in initial 48 hours (64%) vs after (30%; P < .001). Greater compromise (14%) and failure (8%) if inset challenging vs straightforward (6% compromise, 4% failure; P = .035). Greater compromise (23%) and failure (17%) following intraoperative anastomosis revision vs no revision (7% compromise, 4% failure; P < .0001). Success following arterial insufficiency was lower (60% failed, 40% salvaged) vs venous congestion (23% failed, 77% salvaged) (P < .0001). Greater flap salvage following thrombectomy (66%) vs no thrombectomy (34%; P < .0001). Greater flap salvage if operative duration ≤8 hours (57%), vs >8 hours (40%) (P = .04).

CONCLUSIONS

There were higher rates of free flap salvage if the vascular compromise occurred within 48 hours, if due to venous congestion, if operative duration ≤8 hours, and if the anastomosis did not require intraoperative revision.

Non-invasive postoperative monitoring of pedicled rat skin flap using laser speckle contrast imaging

PURPOSE

This study used non-invasive laser speckle contrast imaging (LSCI) modality to evaluate the blood flow changes in murine flap model and to investigate the clinical feasibility of the LSCI for postoperative monitoring.

METHODS

Ten of 6-8 weeks old Spraque-Dawley rats with superficial inferior epigastric vessel based pedicled skin flaps were used in this experiment. The color changes of skin flap were evaluated by naked eyes and the LSCI modality 6, 24, and 48 h after surgery.

RESULTS

In vessel ligated region of skin flap, skin color began to change to a bluish color immediately postoperatively. At 24 h postoperatively, skin necrosis was detectable with the naked eye and total necrosis occurred at 48 h postoperatively. Changes in laser speckle signal were consistent with changes observed with the naked eye, and blood flow index also presented significant differences between the ligated and non-ligated region.

CONCLUSION

These correlated laser speckle signal patterns suggest that non-invasive monitoring of perfusion by LSCI is a useful technology that may be used to identify the ischemic skin flap.

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.

Designing and integrating a quality management program for patients undergoing head and neck resection with free-flap reconstruction

Background

Care pathways (CPs) offer a proven method of systematically improving patient care. CPs are particularly helpful in complex clinical conditions where variation in care is a problem such as patients undergoing major head and neck resection with free flap reconstruction. Although CPs have been used to manage this patient group, most CPs are implemented as part of relatively short-term quality improvement projects. This paper outlines a detailed methodology for designing and delivering a quality management program sustained for 9 years.

Methods

We describe a change management approach informed by Kotter’s “8 Step Process” that provided a useful framework to guide program development and implementation. We then provide a detailed, step by step description of how such a program can be implemented as well as a detailed summary of time and costs for design, implementation and sustainability phases. An approach to design and delivery of a measurement, audit and feedback system is also provided.

Results

We present a summary of resources needed to design and implement a head and neck surgery quality management program. The primary result of this study is a design for a sustainable quality management program that can be used to guide and improve care for patients undergoing major head and neck resection with free flap reconstruction.

Conclusions

A change management approach to design and delivery of a head and neck quality management program is practical and feasible.

The impact of a quality management program for patients undergoing head and neck resection with free-flap reconstruction: longitudinal study examining sustainability

BACKGROUND

Care pathways (CPs) are helpful in reducing unwanted variation in clinical care. Most studies of CPs show they improve clinical outcomes but there is little known about the long-term impact of CPs as part of a sustained quality management program. Head and neck (HN) surgery with free flap reconstruction is complex, time-consuming and expensive. Complications are common and therefore CPs applied to this patient population are the focus of this paper. In this paper we report outcomes from a 9 year experience designing and using CPs in the management of patients undergoing major head and neck resection with free flap reconstruction.

METHODS

The Calgary quality management program and CP design is described the accompanying article. Data from CP managed patients undergoing major HN surgery were prospectively collected and compared to a baseline cohort of patients managed with standard care. Data were retrospectively analyzed and intergroup comparisons were made.

RESULTS

Mobilization, decannulation time and hospital length of stay were significantly improved in pathway-managed patients (p = 0.001). Trend analysis showed sustained improvement in key performance indicators including complications. Return to the OR, primarily to assess a compromised flap, is increasing.

CONCLUSIONS

Care pathways when deployed as part of an ongoing quality management program are associated with improved clinical outcomes in this complex group of patients.

Serial Perioperative Assessment of Free Flap Perfusion With Laser Angiography

Study Design

Prospective cohort study.

Objective

Reconstruction with microvascular free flaps is quite predictable but excessive fluids intraoperatively and excessive use of vasopressors have been implicated in postoperative complications. However, vasopressors assist in limiting fluid administration and counteract vasodilatory effects of general anesthetics, while maintaining proper intravascular volume. This is of paramount importance during surgery to ensure adequate tissue and organ perfusion. The purpose of this study is to quantify perfusion changes in free flaps at specific time points during peri- and postoperative periods, incorporating SPY technology.

Methods

A prospective study of patients who underwent free flap reconstruction was conducted (n = 9), using SPY laser angiography with indocyanine green to assess effects of general anesthetics and vasopressors on flap perfusion. Free flaps were evaluated prior to pedicle division, after inset and anastomosis, and in the immediate postoperative setting. Mean perfusion, mean arterial pressure, total operative time, fluid shifts, and vasopressor use were recorded. Data were analyzed with univariate and multivariable analyses.

Results

Those with major complications in this cohort, on average received less vasopressors, had shorter operation times and less blood loss, however, they received more fluids intraoperatively.

Conclusion

Changes in mean perfusion to the free flap during the intraoperative and immediate postoperative period are nominal.

Intraoperative and postanesthesia care unit fluid administration as risk factors for postoperative complications in patients with head and neck cancer undergoing free tissue transfer

BACKGROUND

This study aims to evaluate the impact of perioperative fluid administration, defined as fluid delivered intraoperatively and in the postanesthesia care unit, on postoperative outcomes.

METHODS

Medical records of 102 patients with oral cavity squamous cell carcinoma undergoing free flap reconstruction between January 2011 and December 2015 were reviewed. The primary endpoint was development of a postoperative complication according to the Clavien-Dindo classification. Perioperative factors recorded were Washington University Head and Neck Comorbidity Index, operating time, vasopressor use, blood loss, intraoperative fluid, and perioperative fluid.

RESULTS

Greater perioperative fluid administration was independently associated with surgical complications, flap complications, overall incidence of any complication, and increased length of stay. Greater intraoperative fluid administration was independently associated with higher rates of surgical complications. Intraoperative delivery of vasopressors was not associated with flap or surgical complications.

CONCLUSION

Receiving less perioperative fluid was associated with fewer complications and decreased length of stay.

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.

Association of Anesthesia Duration With Complications After Microvascular Reconstruction of the Head and Neck

Importance

Prolonged anesthesia and operative times have deleterious effects on surgical outcomes in a variety of procedures. However, data regarding the influence of anesthesia duration on microvascular reconstruction of the head and neck are lacking.

Objective

To examine the association of anesthesia duration with complications after microvascular reconstruction of the head and neck.

Design, Setting, and Participants

The American College of Surgeons National Surgical Quality Improvement Program (NSQIP) database was used to collect data. In total, 630 patients who underwent head and neck microvascular reconstruction were recorded in the NSQIP registry from January 1, 2005, through December 31, 2013. Patients who underwent microvascular reconstructive surgery performed by otolaryngologists or plastic surgeons were included in this study. Data analysis was performed from October 15, 2015, to January 15, 2016.

Exposures

Microvascular reconstructive surgery of the head and neck.

Main Outcomes and Measures

Patients were stratified into 5 quintiles based on mean anesthesia duration and analyzed for patient characteristics and operative variables (mean [SD] anesthesia time: group 1, 358.1 [175.6] minutes; group 2, 563.2 [27.3] minutes; group 3, 648.9 [24.0] minutes; group 4, 736.5 [26.3] minutes; and group 5, 922.1 [128.1] minutes). Main outcomes include rates of postoperative medical and surgical complications and mortality.

Results

A total of 630 patients undergoing head and neck free flap surgery had available data on anesthesia duration and were included (mean [SD] age, 61.6 [13.8] years; 436 [69.3%] male). Bivariate analysis revealed that increasing anesthesia duration was associated with increased 30-day complications overall (55 [43.7%] in group 1 vs 80 [63.5%] in group 5, P = .006), increased 30-day postoperative surgical complications overall (45 [35.7%] in group 1 vs 78 [61.9%] in group 5, P < .001), increased rates of postoperative transfusion (32 [25.4%] in group 1 vs 70 [55.6%] in group 5, P < .001), and increased rates of wound disruption (0 in group 1 vs 10 [7.9%] in group 5, P = .02). No specific medical complications and no overall medical complication rate (24 [19.0%] in group 1 vs 22 [17.5%] in group 5, P = .80) or mortality (1 [0.8%] in group 1 vs 1 [0.8%] in group 5, P = .75) were associated with increased anesthesia duration. On multivariate analysis accounting for demographics and significant preoperative factors including free flap type, overall complications (group 5: odds ratio [OR], 1.98; 95% CI, 1.10-3.58; P = .02), surgical complications (group 5: OR, 2.46; 95% CI, 1.35-4.46; P = .003), and postoperative transfusion (group 5: OR, 2.31; 95% CI, 1.27-4.20; P = .006) remained significantly associated with increased anesthesia duration; the association of wound disruption and increased anasthesia duration was nonsignificant (group 5: OR, 2.0; 95% CI, 0.75-5.31; P = .16).

Conclusions and Relevance

Increasing anesthesia duration was associated with significantly increased rates of surgical complications, especially the requirement for postoperative transfusion. Rates of medical complications were not significantly altered, and overall mortality remained unaffected. Avoidance of excessive blood loss and prolonged anesthesia time should be the goal when performing head and neck free flap surgery.

Level of Evidence

3.

An Important Role of Macrophages for Wound Margin Regeneration in a Murine Flap Model

Background

Macrophages have been known to have diverse roles either after tissue damage or during the wound healing process; however, their roles in flap wound healing are poorly understood. In this study, we aimed to evaluate how macrophages contribute to the flap wound regeneration.

Methods

A murine model of a pedicled flap was generated, and the time-course of the wound healing process was determined. Especially, the interface between the flap and the residual tissue was histopathologically evaluated. Using clodronate liposome, a macrophage-depleting agent, the functional role of macrophages in flap wound healing was investigated. Coculture of human keratinocyte cell line HaCaT and monocytic cell line THP-1 was performed to unveil relationship between the two cell types.

Results

Macrophage depletion significantly impaired flap wound healing process showing increased necrotic area after clodronate liposome administration. Interestingly, microscopic evaluation revealed that epithelial remodeling between the flap tissue and residual normal tissue did not occurred under the lack of macrophage infiltration. Coculture and scratch wound healing assays indicated that macrophages significantly affected the migration of keratinocytes.

Conclusion

Macrophages play a critical role in the flap wound regeneration. Especially, epithelial remodeling at the flap margin is dependent on proper macrophage infiltration. These results implicate to support the cellular mechanisms of impaired flap wound healing.

Intraoperative Use of Vasopressors Does Not Increase the Risk of Free Flap Compromise and Failure in Cancer Patients

OBJECTIVE

To examine the effects of vasopressors on free flap outcomes.

BACKGROUND

Most micro-surgeons avoid the use of vasopressors during free flap surgery due to concerns of vasoconstriction, which could potentially lead to vascular thrombosis and flap failure. Previous studies lack the statistical power to draw meaningful conclusions.

METHODS

All free flaps between 2004 and 2014 from a single institution were reviewed retrospectively. Vasopressors were given intraoperatively as an intravenous bolus when blood pressure dropped >20% from baseline. The timing of intraoperative vasopressor administration was divided into 3 phases: from anesthesia induction to 30 minutes before the start of flap ischemia (P1); end of P1 to 30 minutes after revascularization (P2); end of P2 to end of surgery (P3). Agents included phenylephrine, ephedrine and calcium chloride.

RESULTS

A total of 5671 free flap cases in 4888 patients undergoing head and neck, breast, trunk, or extremity reconstruction were identified. Vasopressors were used intraoperatively in 85% of cases. The overall incidence of pedicle compromise was 3.6%, with a flap loss rate of 1.7%. A propensity score matching analysis showed that intraoperative use of any agents at any time of surgery was not associated with increased overall pedicle compromise [51/1584 (3.2%) vs 37/792 (4.7%); P = 0.074] or flap failure rates [26/1584 (1.6%) vs 19/792 (2.4%); P = 0.209]. Rather, there was less risk of venous congestion [33/1584 (2.1%) vs 31/792 (3.9%); P = 0.010].

CONCLUSIONS

Intraoperative use of phenylephrine, ephedrine, or calcium chloride as an intravenous bolus does not increase flap compromise and failure rates in cancer patients.

Assessment of DIEP Flap Perfusion with Intraoperative Indocyanine Green Fluorescence Imaging in Vasopressor-Dominated Hemodynamic Support Versus Liberal Fluid Administration: A Randomized Controlled Trial With Breast Cancer Patients

BACKGROUND

Dogmatic denial of vasopressor agents for blood pressure regulation during free-flap surgery is associated with concomitant large-volume intraoperative fluid administration. Yet, the doctrinal banning of vasopressors during microvascular breast reconstruction still is a subject of controversy. Several retrospective observations have recently drawn attention to serious iatrogenic consequences of intravenous crystalloid overload in microsurgery such as thrombus formation and increased flap failure rates.

METHODS

This prospective randomized controlled trial investigated the potential effects of fluid-restrictive vasopressor-dominated hemodynamic support (FRV) compared with vasopressor-restrictive liberal fluid administration (LFA) on clinically relevant perfusion of the deep inferior epigastric perforator (DIEP) flap via intraoperative indocyanine green (ICG) fluorescence imaging. The primary end point of the study was quantitative assessment of the percentage of insufficiently perfused tissue (NP) on the overall flap. Major complications were assessed as secondary end points.

RESULTS

In 44 DIEP flap breast reconstructions after mastectomy, FRV circulatory support resulted in no statistically significant difference in total flap perfusion as detected via ICG fluorescence imaging in direct comparison with a traditional LFA strategy (NP_FRV, 31.8% ± 12.2% vs NP_LFA, 29.5% ± 13.3%; p = 0.559). One flap failure was registered with LFA, whereas no major complication occurred in the FRV cohort.

CONCLUSIONS

According to the results of this study, neither a norepinephrine concentration of 0.065 ± 0.020 μg/kg/min (FRV) nor fluid administration of 5.1 ± 2.2 ml/kg/h (LFA) has a clinically significant impact on microperfusion in a standard DIEP flap procedure for breast reconstruction. Consistent with the current literature reporting a rise in complications with intraoperative fluid over-resuscitation, one flap failure occurred in the LFA cohort.

Factors Associated with Free Flap Failures in Head and Neck Reconstruction

Objective

To investigate causes of failure of free flap reconstructions in patients undergoing reconstruction of head and neck defects.

Study Design

Case series with chart review.

Setting

Single tertiary care center.

Subjects and Methods

Patients underwent reconstruction between January 2007 and June 2017 (n = 892). Variables included were clinical characteristics, social history, defect site, donor tissue, ischemia time, and postoperative complications. Statistical methods used include univariable and multivariable analysis of failure.

Results

The overall failure rate was 4.8% (n = 43). Intraoperative ischemia time was associated with free flap failures (odds ratio [OR], 1.062; 95% confidence interval [CI], 1.019-1.107; P = .004) for each addition of 5 minutes. Free flaps that required pedicle revision at time of initial surgery were 9 times more likely to fail (OR, 9.953; 95% CI, 3.242-27.732; P < .001). Patients who experienced alcohol withdrawal after free flap placement were 3.7 times more likely to experience flap failure (OR, 3.690; 95% CI, 1.141-10.330; P = .031). Ischemia time remained an independent significant risk factor for failure in nonosteocutaneous free flaps (OR, 1.105; 95% CI, 1.031-1.185). Alcohol withdrawal was associated with free flap failure in osteocutaneous reconstructions (OR, 5.046; 95% CI 1.103-19.805) while hypertension was found to be protective (OR, 0.056; 95% CI, 0.000-0.445).

Conclusion

Prolonged ischemia time, pedicle revision, and alcohol withdrawal were associated with higher rates of flap failure. Employing strategies to minimize ischemic time may have potential to decrease failure rates. Flaps that require pedicle revision and patients with a history of significant alcohol use require closer monitoring.

Shift in the timing of microvascular free tissue transfer failures in head and neck reconstruction

OBJECTIVE

Analyze the cause and significance of a shift in the timing of free flap failures in head and neck reconstruction.

STUDY DESIGN

Retrospective multi-institutional review of prospectively collected databases at tertiary care centers.

METHODS

Included consecutive patients undergoing free flap reconstructions of head and neck defects between 2007 and 2017. Selected variables: demographics, defect location, donor site, free flap failure cause, social and radiation therapy history.

RESULTS

Overall free flap failure rate was 4.6% (n = 133). Distribution of donor tissue by flap failure: radial forearm (32%, n = 43), osteocutaneous radial forearm (6%, n = 8), anterior lateral thigh (23%, n = 31), fibula (23%, n = 30), rectus abdominis (4%, n = 5), latissimus (11%, n = 14), scapula (1.5%, n = 2). Forty percent of flap failures occurred in the initial 72 hours following reconstruction (n = 53). The mean postoperative day for flap failure attributed to venous congestion was 4.7 days (95% confidence interval [CI], 2.6-6.7) versus 6.8 days (CI 5.3-8.3) for arterial insufficiency and 16.6 days (CI 11.7-21.5) for infection (P < .001). The majority of flap failures were attributed to compromise of the arterial or venous system (84%, n = 112). Factors found to affect the timing of free flap failure included surgical indication (P = .032), defect location (P = .006), cause of the flap failure (P < .001), and use of an osteocutaneous flap (P = .002).

CONCLUSION

This study is the largest to date on late free flap failures with findings suggesting a paradigm shift in the timing of flap failures. Surgical indication, defect site, cause of flap failure, and use of osteocutaneous free flap were found to impact timing of free flap failures.

LEVEL OF EVIDENCE

4 Laryngoscope, 130:347-353, 2020.

Engineering of microscale vascularized fat that responds to perfusion with lipoactive hormones

Current methods to treat large soft-tissue defects mainly rely on autologous transfer of adipocutaneous flaps, a method that is often limited by donor site availability. Engineered vascularized adipose tissues can potentially be a viable and readily accessible substitute to autologous flaps. In this study, we engineered a small-scale adipose tissue with pre-patterned vasculature that enables immediate perfusion. Vessels formed after one day of perfusion and displayed barrier function after three days of perfusion. Under constant perfusion, adipose tissues remained viable and responded to lipoactive hormones insulin and epinephrine with lipid accumulation and loss, respectively. Adipocyte growth correlated inversely with distance away from the feeding vessel, as predicted by a Krogh-type model.

Intraoperative hypotension and flap loss in free tissue transfer surgery of the head and neck

BACKGROUND

In free flap head and neck reconstructions, hemodynamic management is complicated by the deleterious effects of excessive crystalloid administration. Patients may undergo periods of hypotension or excess fluid administration. The purpose of this study was to present our examination of the hypotheses that intraoperative hypotension and blood pressure lability are associated with increased fluid administration and flap failure.

METHODS

We reviewed the records of 445 patients undergoing head and neck surgery involving free tissue transfer. We used multivariate logistic regression to examine the relationship between hemodynamic variables and flap loss (primary outcome) and other complications.

RESULTS

On multivariate analysis, intraoperative hypotension and large-volume fluid administration were associated with flap loss. Neither blood pressure lability nor vasopressor administration was significantly associated to our primary outcome.

CONCLUSIONS

Intraoperative hypotension is associated to flap failure in head and neck free tissue transfer surgeries, as is large-volume fluid administration.

Use of Laser Speckle Contrast Imaging for Successful Fingertip Replantation

Fingertip replantation is a technical challenge for microsurgeons. For successful fingertip replantation, it is important to monitor the replanted fingertip vascularity for the early detection and revision of vascular compromise. Laser speckle contrast imaging (LSCI) is a camera-based technique that measures the perfusion by illuminating the tissue with a 785-nm-wavelength divergent laser beam. This creates a speckle pattern over the illuminated area. We present a case in which postoperative monitoring of the replanted fingertip microcirculation using LSCI allowed for successful Tamai zone I fingertip replantation. Postoperative monitoring using LSCI has 3 main advantages. First, this method is harmless to the patient and the replanted fingertip. A camera-based technique enables microcirculation monitoring without touching the patient or the replanted fingertip. Second, tissue perfusion is measured in real time and recorded continuously, allowing for the rapid response to the arterial or venous occlusion to be observed. Third, using LSCI, the skin perfusion can be measured quantitatively. Although further clinical investigations will be required to confirm its efficacy, LSCI has the potential to be a useful monitoring device.

Predictors of Adverse Outcomes in Free Flap Reconstruction: A Single-Institution Experience

Objective

Understanding the independent predictors of poor outcomes in free flap surgery is essential for patient selection. We aim to determine the independent predictors of major complications, flap survival, and extended hospital stays.

Study Design

Retrospective cohort study.

Setting

Tertiary medical center.

Subjects and Methods

We reviewed medical records from all vascularized tissue transfers in the head and neck between 2007 and 2014 at our institution. We recorded demographics, medical comorbidities, disease characteristics, flap characteristics, and intraoperative events. We defined outcomes as major complications in the 30-day postoperative period, flap death or partial flap survival, and a length of stay ≥14 days. We used bivariate and multivariate methods to test for associations.

Results

Of 170 free flap operations, 44% had major complications; 11% fully or partially failed; and 27% required an extended hospital stay. Independent predictors of major complications were age ≥60 years (odds ratio [OR], 3.7; P = .001), revision surgery (OR, 3.5; P = .004), and a prior neck dissection (OR, 3.5; P = .004). Independent predictors of flap failure were revision surgery (OR, 4.1, P = .01) and the use of a plate (OR, 3.7; P = .03). Revision surgery was independently associated with a longer stay (OR, 3.0; P = .01), and the use of a radial forearm flap was associated with a shorter stay (OR, 0.3, P = .047).

Conclusion

These results underscore that caution is warranted in revision flap surgery, patients with prior neck operations, and patients aged ≥60 years.

Vascular Occlusion in a Porcine Flap Model: Effects on Blood Cell Concentration and Oxygenation

Background:

Venous congestion in skin flaps is difficult to detect. This study evaluated the ability of tissue viability imaging (TiVi) to measure changes in the concentration of red blood cells (CRBC), oxygenation, and heterogeneity during vascular provocations in a porcine fasciocutaneous flap model.

Methods:

In 5 pigs, cranial gluteal artery perforator flaps were raised (8 flaps in 5 pigs). The arterial and venous blood flow was monitored with ultrasonic flow probes. CRBC, tissue oxygenation, and heterogeneity in the skin were monitored with TiVi during baseline, 50% and 100% venous occlusion, recovery, 100% arterial occlusion and final recovery, thereby simulating venous and arterial occlusion of a free fasciocutaneous flap. A laser Doppler probe was used as a reference for microvascular perfusion in the flap.

Results:

During partial and complete venous occlusion, increases in CRBC were seen in different regions of the flap. They were more pronounced in the distal part. During complete arterial occlusion, CRBC decreased in all but the most distal parts of the flap. There were also increases in tissue oxygenation and heterogeneity during venous occlusion.

Conclusions:

TiVi measures regional changes in CRBC in the skin of the flap during arterial and venous occlusion, as well as an increase in oxygenated hemoglobin during venous occlusion that may be the result of reduced metabolism and impaired delivery of oxygen to the tissue. TiVi may provide a promising method for measuring flap viability because it is hand-held, easy to-use, and provides spatial information on venous congestion.

Venous Complications in One Versus Two Vein Anastomoses in Head and Neck Free Flaps

OBJECTIVE

The purpose of this study was to compare rates of reexploration and flap failure in patients with 1- and 2-vein anastomoses in free flap reconstructions.

METHODS

Retrospective chart review of 300 patients undergoing free flap reconstruction to head and neck defects from 2010 to 2014.

RESULTS

One venous anastomosis was performed in 229 patients, and 2 venous anastomoses were performed in 71 patients. The 1-vein group had significantly more reexplorations in the operating room (36/229, 15.7%) compared with the 2-vein group (4/71, 5.6%; P = .028), even when controlling for flap type ( P = .022). This finding remained true among radial forearm flaps (17/81, 21% vs 3/53, 5.7%; P = .024). The number of venous anastomoses was not significantly associated with flap failure, though patients with flap failure did have a significantly greater proportion of venous issues ( P < .001).

CONCLUSIONS

Two-vein anastomoses do not appear to reduce rates of flap failure or postoperative venous thrombosis but are associated with a lower number of reexplorations in the operating room even after accounting for differences in flap types and surgeons.