Intraoperative factors associated with free flap failure in the head and neck region: a four-year retrospective study of 216 patients and review of the literature

Predictive Factors of Free Flap Volume Evolution in Head and Neck Reconstruction

OBJECTIVE

The aim of our study was to determine the factors influencing the evolution of the total volume and bone volume of free flaps commonly used in head and neck surgery, with a 30-month prospective study, to establish volume change predictions and thus propose a degree of overcorrection to be expected before reconstruction.

STUDY DESIGN

We prospectively included all consecutive free flap.

SETTING

Our maxillofacial surgery department between August 2021 and January 2024.

METHODS

We collected information on preoperative, per-operative, and postoperative factors, on patients, surgical techniques, and adjuvant treatments. We measured on each postoperative imaging the overall flap volume and bone volume if applicable. Multivariate mixed models were then used to select clinical parameters associated with volume loss.

RESULTS

We included 166 flaps, performed on 155 patients. The mean age was 60.1 ± 15.1 years. A total of 634 imagings were segmented (487 computed tomography [CT] scans, 77%; 147 magnetic resonance imagings [MRIs], 23%). The use of the superior thyroid or lingual veins for venous anastomosis, such as the use of small couplers, resulted in negative volume changes. Predicted bone volumes decreased by 23% at 30 months for deep circumflex iliac artery (DCIA) free flaps, 19% for fibula free flap (FFF), and 38% for scapular system free flap (SFF).

CONCLUSION

These findings allow us to envisage a volume overcorrection of around 60% for fasciocutaneous or osteocutaneous flaps, and 75% for muscle or osteomuscular flaps. The choice of vein and microsurgical technique seems to have more impact on the evolution of free flap volume than patient characteristics or adjuvant treatments.

Prognostic Factors for Free Flap Failure in Head and Neck Reconstruction

BACKGROUND

The failure rate of free flaps varies from 0.8% to 10.6% in the literature in head and neck reconstruction. The primary objective was to identify prognostic factors for free flap failure.

METHODS

We prospectively included all consecutive free flaps performed between August 2021 and January 2024, and used a multivariate Cox proportional hazard model.

RESULTS

We included 307 free flaps, performed on 274 patients. Age, cardiovascular risk, radiotherapy history, type of flap, type of arterial anastomosis, and ischemia duration were not statistically linked to the risk of flap failure. In multivariate analysis, a venous anastomosis to the anterior jugular vein or to the superior thyroid vein were associated with an increased risk of flap failure, such as per- or postoperative revision of the anastomoses.

CONCLUSIONS

The choice of venous anastomosis, appear to have a greater influence on the success or failure of a microvascularized transfer than patient characteristics.

Intraoperative circulation predict prolonged length of stay after head and neck free flap reconstruction: a retrospective study based on machine learning

Background

Head and neck free flap reconstruction presents challenges in managing intraoperative circulation, potentially leading to prolonged length of stay (PLOS). Limited research exists on the associations between intraoperative circulation and PLOS given the difficulty of manual quantification of intraoperative circulation time-series data. Therefore, this study aimed to quantify intraoperative circulation data and investigate its association with PLOS after free flap reconstruction utilizing machine learning algorithms.

Methods

804 patients who underwent head and neck free flap reconstruction between September 2019 and February 2021 were included. Machine learning tools (Fourier transform, et al.) were utilized to extract features to quantify intraoperative circulation data. To compare the accuracy of quantified intraoperative circulation and manual intraoperative circulation assessments in the PLOS prediction, predictive models based on these 2 assessment methods were developed and validated.

Results

Intraoperative circulation was quantified and a total of 114 features were extracted from intraoperative circulation data. Quantified intraoperative circulation models with a real-time predictive manner were constructed. A higher area under the receiver operating characteristic curve (AUROC) was observed in quantified intraoperative circulation data models (0.801 [95% CI, 0.733-0.869]) compared to manual intraoperative circulation assessment models (0.719 [95% CI, 0.641-0.797]) in PLOS prediction.

Conclusion

Machine learning algorithms facilitated quantification of intraoperative circulation data. The developed real-time quantified intraoperative circulation prediction models based on this quantification offer a potential strategy to optimize intraoperative circulation management and mitigate PLOS following head and neck free flap reconstruction.

Determination of Quality Indicators for Microvascular Grafts in Cranio-Maxillofacial Surgery-A Retrospective Analysis of 251 Free Flaps

BACKGROUND

The use of microvascular grafts is the gold standard in oral and maxillofacial surgery for the reconstruction of soft tissue and bony and combined defects. Graft loss is one of the most serious complications in the field of reconstructive surgery. A comprehensive analysis of factors influencing this is, therefore, essential.

METHODS

This hypothesis-generating study analyzed 251 patient cases of oral and maxillofacial surgery at the University Hospital Düsseldorf from 2016 to 2020 regarding patient- and therapy-specific parameters for their impact on graft survival.

RESULTS

Statistically significant influencing factors were found among the 80 parameters examined: treatment with antiplatelet medication and a BMI ≥ 24.5 at the time of surgery had a positive influence on graft survival, while existing diabetes mellitus, atrial fibrillation, tracheostomy, and a longer operation time had a statistically relevant negative influence.

CONCLUSIONS

This work demonstrates the relevance of patient-specific risk stratification and the need for further research to develop a valid risk profile. Identifying high-risk patients with medium-sized defects, where alternatives to microvascular reconstruction are available, appears to be crucial for the clinical outcome.

State of Head and Neck Microvascular Reconstruction: Current and Future Directions

Since its inception, microvascular free tissue transfer has broadened possibilities for oncologic ablation and restoration of form and function. Developments throughout recent decades have resulted in increasing flap success rates and complexity. Advances in technology and knowledge gained from past experiences will continue to improve surgical efficiency, flap success rates, and ultimately, patient outcomes.

Postoperative inpatient surgical complications following head and neck microvascular free tissue transfer

BACKGROUND

Complications following head and neck microvascular free tissue transfer (MFTT) are common. Less is known about when they occur.

METHOD

Retrospective study of patients with primary or recurrent head and neck cancer undergoing MFTT reconstruction at a tertiary care institution. MFTT reconstructions with inpatient postoperative complications were included. The Kruskal-Wallis test was used to compare median postoperative day (POD) onset of complication by flap type.

RESULTS

Of 1090 patients undergoing MFTT reconstruction, 126 (11.6%) patients experienced inpatient complications including fibula (n = 35), anterolateral thigh (n = 60), or radial forearm (n = 31) MFTTs. POD onset was shortest for surgical site hematoma (median = 1 [IQR 1-5]), and longest for donor site infection (median = 11.5 [IQR 8-15]). There was no significant difference between flap types and POD onset of complications (p > 0.05).

CONCLUSION

Hematoma formation and flap failure occur earliest during hospitalization, while dehiscence, infection, and fistula occur later. There is no difference in complication timing between flap types.

The risk of free flap revision and subsequent medical costs in patients with hypopharyngeal cancer

BACKGROUND

Few studies have examined the preoperative risks and healthcare costs related to free flap revision in hypopharyngeal cancer (HPC) patients.

METHODS

A 20-year retrospective case-control study was conducted using the Chang Gung Research Database, focusing on HPC patients who underwent tumor excision and free flap reconstruction from January 1, 2001, to December 31, 2019. The impacts of clinical variables on the need for re-exploration due to free flap complications were assessed using logistic regression. The direct and indirect effects of these complications on medical costs were evaluated by causal mediation analysis.

RESULTS

Among 348 patients studied, 43 (12.4%) developed complications requiring re-exploration. Lower preoperative albumin levels significantly increased the risk of complications (OR 2.45, 95% CI 1.12-5.35), especially in older and previously irradiated patients. Causal mediation analysis revealed that these complications explained 11.4% of the effect on increased hospitalization costs, after controlling for confounders.

CONCLUSIONS

Lower preoperative albumin levels in HPC patients are associated with a higher risk of microvascular free flap complications and elevated healthcare costs, underscoring the need for enhanced nutritional support before surgery in this population.

LEVEL OF EVIDENCE: 3

Flap loss in head and neck reconstruction: Is there a singular cause for failure?

Despite the high success rates reported in head and neck reconstruction, free flap failures continue to persist. Understanding the factors associated with flap loss and improving overall success are paramount. This study aimed to comprehensively assess the factors influencing flap revision and free tissue transfer survival in head and neck reconstruction. The study included 70 patients with defects in the lower two-thirds of the head and neck region and underwent reconstruction using free flaps. Patient age, gender, smoking status, comorbidities and data on the location and aetiology of the defect, the specific type of flap employed, the recipient artery and vein chosen, instances of revision and the overall success of the flap were collected. The investigation aimed to establish correlations between these variables as well as flap success and revision rates. No statistically significant differences were observed in arterial and venous anastomosis revision rates, or flap survival, in relation to variables such as age, gender, flap type, smoking status, comorbidities, recipient artery or vein and the number of vein anastomoses. The malignant tumour group exhibited a lower requirement for arterial revision and a higher flap survival rate compared to the benign tumour group. This study underscores the comparable safety profiles of perforator-based and conventional flaps in head and neck reconstruction. Furthermore, it reveals that patient characteristics are not contraindications for free tissue transfer. Additionally, the quantity of the veins and choice of recipient vessels are flexible and do not significantly impact flap success. The higher rates of flap success in patients with malignant aetiology requires further investigation.

Advances in Regenerative Dentistry Approaches: An Update

Regenerative dentistry is a rapidly evolving field in dentistry, which has been driven by advancements in biomedical engineering research and the rising treatment expectations and demands that exceed the scope of conventional approaches. Tissue engineering, the foundation of regenerative dentistry, mainly focuses on 3 key components: stem cells, bioactive molecules, and scaffolds. Dental tissue-derived stem cells are especially significant in this regard due to their remarkable properties. Regenerative techniques have provided novel approaches to many conventional treatment strategies in various disciplines of dentistry. For instance, regenerative endodontic procedures such as pulp revascularisation have provided an alternative approach to conventional root canal treatment. In addition, conventional surgical and nonsurgical periodontal treatment is being taken over by modified approaches of guided tissue regeneration with the aid of 3-dimensional bioprinting and computer-aided design, which has revolutionised oral and maxillofacial tissue engineering. This review presents a concise overview of the latest treatment strategies that have emerged into clinical practice, potential future technologies, and the role of dental tissue-derived stem cells in regenerative dentistry.

Introduction and preliminary application report for a novel 3D printed perforator navigator for fibular flap surgery

The aim of this study was to introduce and report on a 3D-printed perforator navigator and its clinical application. Integrated imaging and 3D printing techniques were employed for the design and manufacture of a perforator navigator. Key techniques included establishing a digital image coordinate system, localizing perforator fascia piercing points, creating a reference plane for the perforator course, and projecting the perforator course onto the body surface. All cases of maxillofacial defect repaired with free fibular myocutaneous flaps, from January 2019 to January 2022, were reinvestigated. Patients treated using traditional perforator localization methods were assigned into group Ⅰ, while those who had a navigator used during treatment were allocated to group Ⅱ. Outcome measurements included perforator positioning accuracy, perforator preparation time (PT), and flap growth score. Capillary refilling time and degree of flap swelling were recorded on the 1st, 3rd, and 7th days after surgery. On the 10th day after surgery, the flap survival situation was graded. In total, 25 patients were included in the study. Perforator preparation time for group Ⅱ was significantly less (p ＝ 0.04) than for group Ⅰ (1038.6 ± 195.4 s versus 1271.4 ± 295.1 s. In group Ⅱ, the mean positioning deviation for the perforator navigator was 2.12 cm less than that for the high-frequency color Doppler (p ＝ 0.001). Group Ⅱ also had a higher score than group Ⅰ for overall flap growth evaluation (nonparametric rank sum test, p ＝ 0.04). Within the scale of the study, it seems that perforator localization and navigation using a 3D-printed navigator is technically feasible, and helps to improve the clinical outcome of free fibular flaps. The perforator navigator will play a useful role in displaying the perforator course, improving the accuracy of perforator localization, reducing surgical injury, and ultimately enhancing flap success rate.

Effect of 2 Teams and Operative Time on Complications After Oral Cavity Free Flap Reconstruction

OBJECTIVE

Evaluate the effects of operative time and 2 team approach on complications after soft tissue free flap reconstruction for oral tongue cancer.

METHODS

Patients with oncologic glossectomy with myocutaneous or fasciocutaneous free flap reconstruction were included from the 2015 to 2018 American College of Surgery National Surgical Quality Improvement Program. The primary predictive variables assessed were operative time and 2 team approach; control variables included age, sex, body mass index (BMI), 5-question-modified frailty index (mFI-5), American Society of Anesthesiologists (ASA) class, and total work relative value units (wRVU). Outcomes assessed included 30-day mortality, 30-day reoperation, hospital length of stay beyond 30 days, readmission, medical and surgical complications, and non-home discharge. Multivariable logistic/linear regression models were used to predict surgical outcomes.

RESULTS

Microvascular soft tissue free flap reconstruction of the oral cavity after glossectomy was performed on 839 patients. Operative time was independently associated with readmission, prolonged length of stay, surgical complications, medical complications, and non-home discharge. A 2-team approach was independently associated with prolonged length of stay and medical complications. The mean operative time of the 1-team and 2-team approach was 8.73 and 9.13 hours. The 1-team approach did not significantly increase operative time (P = .16).

CONCLUSIONS

In the largest study to date of operative time on post-surgical outcomes after glossectomy and soft tissue free flap reconstruction, we found longer operative times increased rates of postoperative complications and non-home discharge. The 1-team approach is non-inferior to the 2-team approach with respect to operating time and complications.

Practice Trends and Evidence-Based Practice in Microvascular Reconstruction

Microvascular and free flap reconstruction are important to the otolaryngology-head and neck surgery practice. Herein, the reader will find an up-to-date discussion of various evidence-based practice trends related to microvascular surgery, including surgical techniques, anesthetic and airway considerations, free flap monitoring and troubleshooting, surgical efficiency, and both patient-related and surgeon-related risk factors that may affect outcomes.

Post-reconstruction Free Flap Complications After Oral Cancer Ablation

Introduction

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

Patients and Methods

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

Results

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

Conclusion

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

Anaesthesia for reconstructive free flap surgery for head and neck cancer

Head and neck cancer surgery presents significant challenges for the anaesthetist. A thorough multidisciplinary preoperative assessment and optimisation of the patient is essential, including nutritional and psychological evaluation. The incidence of a difficult airway is high, and the anaesthetist must be skilled in advanced airway techniques. Surgery is extensive, often requiring reconstructive surgery with either a pedicled or free flap. Detailed knowledge of flap physiology and anatomy is needed, and anaesthesia comprises careful management of mean arterial pressure, fluid administration, temperature control and oxygenation. The Enhanced Recovery after Surgery Society and the Society for Head and Neck Anaesthesia consensus recommendations provide guidance on current best practice. Despite continued debate, it now appears that this constitutes goal-directed fluid therapy, coupled with judicious vasopressor therapy sufficient to achieve an adequate mean arterial pressure. Emerging techniques such as prehabilitation and postoperative near-infrared spectroscopy flap monitoring provide hope of improved outcomes going forward.

Flap failure prediction in microvascular tissue reconstruction using machine learning algorithms

BACKGROUND

Microvascular tissue reconstruction is a well-established, commonly used technique for a wide variety of the tissue defects. However, flap failure is associated with an additional hospital stay, medical cost burden, and mental stress. Therefore, understanding of the risk factors associated with this event is of utmost importance.

AIM

To develop machine learning-based predictive models for flap failure to identify the potential factors and screen out high-risk patients.

METHODS

Using the data set of 946 consecutive patients, who underwent microvascular tissue reconstruction of free flap reconstruction for head and neck, breast, back, and extremity, we established three machine learning models including random forest classifier, support vector machine, and gradient boosting. Model performances were evaluated by the indicators such as area under the curve of receiver operating characteristic curve, accuracy, precision, recall, and F1 score. A multivariable regression analysis was performed for the most critical variables in the random forest model.

RESULTS

Post-surgery, the flap failure event occurred in 34 patients (3.6%). The machine learning models based on various preoperative and intraoperative variables were successfully developed. Among them, the random forest classifier reached the best performance in receiver operating characteristic curve, with an area under the curve score of 0.770 in the test set. The top 10 variables in the random forest were age, body mass index, ischemia time, smoking, diabetes, experience, prior chemotherapy, hypertension, insulin, and obesity. Interestingly, only age, body mass index, and ischemic time were statistically associated with the outcomes.

CONCLUSION

Machine learning-based algorithms, especially the random forest classifier, were very important in categorizing patients at high risk of flap failure. The occurrence of flap failure was a multifactor-driven event and was identified with numerous factors that warrant further investigation. Importantly, the successful application of machine learning models may help the clinician in decision-making, understanding the underlying pathologic mechanisms of the disease, and improving the long-term outcome of patients.

Orthoplastic reconstruction in children: are the risk factors similar to those observed in adults?

Free flaps in the pediatric population are less common and when indicated the expectations to avoid amputation are high. The objective of this study is to describe indications and results of free flaps for limb reconstruction. Patients undergoing microsurgical free flaps in an orthopedic hospital were consecutively included in this cross-sectional study, from 2014 to 2020. Data regarding personal medical history, intraoperative microsurgical procedure and laboratory tests were collected. Patients under 18 years of age were included. Complications and free flap outcomes were observed during follow-up. This study included 23 free flaps in 23 patients with orthoplastic reconstruction. The free flap was performed as a reconstructive elevator concept. The most common indications were skin or bone defects caused by trauma (nine patients), tumor (six patients) and congenital pseudarthrosis of the tibia (four patients). The most indicated flap was a vascularized fibular flap in 10 patients, followed by an anterolateral thigh flap in 5 patients. Complications were observed in five patients. In total 93% of patients with inferior limb reconstruction walked at the final evaluation. Among risk factors studied, cases had a higher incidence of complications (P = 0.03) when only the superficial venous system was used. Free flaps in children are well-tolerated and indications are restricted to precise indications to provide alternatives to amputations and improve patient's function. We observed an increase in the incidence of complications when only superficial veins were used for free flap outflow in children.

Effect of preoperative radiation on free flap outcomes for head and neck reconstruction: An updated systematic review and meta-analysis

BACKGROUND

There is an ongoing debate about whether neoadjuvant radiation therapy is associated with higher rates of postoperative complications after head and neck reconstruction. Herle et al. conducted a systematic review in 2014 of 24 studies, finding higher complication rates in irradiated fields. We sought to perform an exhaustive updated systematic review and meta-analysis.

METHODS

We conducted an updated systematic review of the literature, as outlined in our protocol, which was registered on PROSPERO. Databases included Medline, Embase, Cochrane Central, and Web of Science. There were no limits placed on the date range, place of publication, or origin. Exclusion criteria included patients less than 18 years of age, studies with less than 20 participants (n < 20), case studies, skull base reconstructions, and local tissue rearrangements. The combined results of the studies and relative risks (RR) were calculated.

RESULTS

53 studies were included for analysis, including 5,086 free flaps in an irradiated field, and 9,110 free flaps in a non-irradiated field. Of the 53 studies, 21 studies overlapped with those discussed in Herle et al.'s study, with a total of 32 additional studies. Neoadjuvant radiation was found to be a statistically significant risk factor for postoperative complications (RR 1.579, P < 0.001), total flap failure (RR, 1.565; P < 0.001), and fistula (RR, 1.810; P < 0.001). Our work reaffirmed the findings of the Herle et al.

STUDY

CONCLUSION

Preoperative radiation was associated with a statistically significant increase in the risk of total flap failure, fistula, and total complications but not partial flap failure. These high-morbidity complications must be taken into consideration when determining which patients should receive neoadjuvant radiation therapy.

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.

The Impact of Healthcare-Associated Infections in Patients Undergoing Oncological Microvascular Head and Neck Reconstruction: A Prospective Multicentre Study

Simple Summary

Healthcare-associated infections (HAIs) result in an increased morbidity and a delay in adjuvant therapy—thus increasing the cancer recurrence rates—in patients undergoing oncological microvascular head and neck reconstruction. HAIs also result in a cost increase for the Health System. We prospectively analysed the incidence, clinical characteristics, risk factors and impacts of these infections in 65 patients undergoing head and neck free-flap reconstruction in three third-level university hospitals in Madrid (Spain). The three of them implemented the same antibiotic prophylactic regimen for surgical interventions. The rate of HAIs was 61.54%. The following complications were significantly more frequent in patients with HAIs: need to reoperate (p = 0.009), duration of hospital admission (p < 0.001) and delay in starting radiotherapy (p = 0.009). This manuscript aims to point out the importance of preventing HAIs in head and neck cancer patients, as they have shown a higher risk of postoperative complications.

Abstract

(1) Background: Healthcare-associated infections (HAIs) after head and neck free-flap reconstruction are a common postoperative complication. Risk factors for HAIs in this context and their consequences have not been adequately described. (2) Methods: Ongoing prospective multicentre study between 02/2019 and 12/2020. Demographic characteristics and outcomes were analysed, focusing on infections. (3) Results: Forty out of 65 patients (61.54%) suffered HAIs (surgical site infection: 52.18%, nosocomial pneumonia: 23.20%, bloodstream infection: 13% and urinary tract infection: 5.80%). Methicillin-resistant Staphylococcus aureus (MRSA) and resistant Pseudomonas aeruginosa, Klebsiella pneumoniae and Enterobacter cloacae were the most frequently implicated. The significant risk factors for infection were: previous radiotherapy (Odds ratio (OR): 5.42; 95% confidence interval (CI), 1.39–21.10), anaemia (OR: 8.00; 95% CI, 0.96–66.95), salvage surgery (eight out of eight patients), tracheostomy (OR: 2.86; 95% CI, 1.01–8.14), surgery duration (OR: 1.01; 95% CI, 1.00–1.02), microvascular reoperation <72 h (eight/eight) and flap loss (eight/eight). The major surgical complications were: a need to reoperate (OR: 6.89; 95% CI, 1.42–33.51), prolonged hospital admission (OR: 1.16; 95% CI, 1.06–1.27) and delay in the initiation of postoperative radiotherapy (OR: 9.07; 95% CI, 1.72–47.67). The sixth month mortality rate in patients with HAIs was 7.69% vs. 0% in patients without HAIs (p = 0.50). (4) Conclusions: HAIs were common after this type of surgery, many of them caused by resistant microorganisms. Some modifiable risk factors were identified. Infections played a role in cancer prognosis by delaying adjuvant therapy.

Perioperative predictors of early surgical revision and flap-related complications after microvascular free tissue transfer in head and neck reconstructions: a retrospective observational series

Objectives

The aim of this study was to determine the influence of perioperative fluid management and administration of vasopressors on early surgical revision and flap-related complications in free tissue transfer.

Materials and methods

Intraoperative amount of fluid and of vasopressors, relevant perioperative parameters, and comorbidities were recorded in 131 patients undergoing head and neck microvascular reconstruction and compared with early surgical complications, defined as interventions requiring surgery after a flap-related complication, and/or other surgical problems in the operating room within 30 days after initial surgery. The relationship between perioperative variables for each revision category was determined using an optimized multiple logistic regression.

Results

The administration of diuretics (p=0.001) as a treatment for perioperative fluid overload and the type of flap (p=0.019) was associated with a higher risk of early surgical revisions. Perioperative fluid overload (p=0.039) is significantly related to flap-related complications. We found no effect of intraoperative administration of vasopressors on early surgical revisions (p=0.8) or on flap-related complications (norepinephrine p=0.6, dobutamine p=0.5).

Conclusion

Perioperative fluid overload is associated with higher risks of early surgical revision and flap-related complications. In contrast, the administration of vasopressors seemed to have no effect on either surgical revision rate or flap-related complications.

Clinical relevance

In patients receiving microvascular reconstructions, a balanced fluid administration perioperatively and a targeted use of vasopressors should be the necessary strategy to reduce the complication rates in head and neck surgery.

Avoiding the night terrors: the effect of circadian rhythm on post-operative urine output and blood pressure in free flap patients

Multiple studies demonstrate the importance of goal-directed fluid regimens in avoiding complications. These regimens do not take account of circadian fluctuations in urine output (UO), MAP (mean arterial pressure) and pulse rate (PR). This is the first study that aims to demonstrate the effect of circadian rhythm on these haemodynamic parameters in post-operative patients with free flaps, as well as analysing clinicians' response to these variations. Retrospective analysis of 116 patients with free flaps. Records were assessed for UO, MAP, IV fluid infusion rate, oral fluid intake. Parameters were measured from 8 am to 8 pm (diurnal) and from 8 pm to 8 am (nocturnal) in the first 48 h post operatively. Patients with diabetes or hypertension were excluded. Mean diurnal UO rate (1.7 ml/kg/hr) was higher than nocturnal UO rate (0.7 ml/kg/hr); and mean diurnal MAP (93) was higher than nocturnal MAP (73.8). Mean diurnal IV infusion rate was 1.25 ml/kg/hr (lower) and mean nocturnal infusion rate 1.81 ml/kg/hr (higher). These differences were all statistically significant by paired student t-test (p < 0.05). This study demonstrates that circadian rhythm has a statistically significant impact on UO, MAP and PR. UO, MAP and PR are expected to dip overnight. This dip is normal and does not necessarily need to be treated by increasing IV fluids to avoid over filling of free flap patients.

Flap demise reversed after central venous access device removal: A case report

Patients undergoing head and neck free flap reconstruction should be evaluated for radiation-induced venous stenosis and presence of central venous port as a potential risk for flap failure.

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.